Datasets:

factored

/

us_patent_hub

like 0

GOVERNMENTAL INTEREST The invention described herein may be manufactured, used, and licensed by or for the Government for Governmental purposes without payment to me of any royalties thereon. BACKGROUND OF THE INVENTION The present invention relates to projectiles for firing in a gun barrel, and in particular, to projectiles that have rotating parts to reduce projectile spin. For most small arms weapon systems, that is, weapon systems of caliber 40 mm or less, the gun barrels are rifled to induce a high angular spin to projectiles exiting the muzzle. Projectiles requiring spin for aerodynamic stability are called spin-stabilized projectiles. For other projectile types that do not require a high angular spin (or types that experience degraded performance when spun, e.g., fin stabilized projectiles) a "slip device" is normally mounted on the projectile body to reduce or eliminate spin induced by the rifling. This rotating device usually consists of a rotating band that is free to rotate or slip around the projectile body, thereby permitting only axial projectile motion and not rotational motion during firing. This technique has been used successfully with large caliber ammunition and in some instances with small caliber ammunition. A serious drawback with the foregoing technique is that the "slip device," which is usually composed of a polymeric type material, is exposed to the environment and is subject to possible damage. Rough handling by soldiers and exposure to machine oils are just a few possible situations that may damage the "slip device." This situation can lead to poor performance or failure of the ammunition if sufficient damage occur to the "slip device." Accordingly, there is a need for an arrangement to reduce the spinning of a projectile to avoid performance degradation in a way that is relatively immune to damage from handling. SUMMARY OF THE INVENTION In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a projectile for firing in a gun barrel. The projectile has a jacket and a bearing sleeve mounted in the jacket. This jacket is of different material than the bearing sleeve. A journal sleeve is mounted in the bearing sleeve to axially rotate therein. A load is mounted in the journal sleeve to rotate therewith. Thus the angular rotation of the load with respect to the gun barrel is reduced. In a related embodiment of the same invention, the projectile has a bearing sleeve, a journal sleeve and a load. The bearing sleeve has a predetermined axial length. The journal sleeve is of about the same predetermined axial length. Similarly, the load is about the same predetermined axial length. By employing apparatus of the forgoing type, an improved projectile is achieved. The preferred embodiment is able to reduce the angular rotation of the internal load of a projectile despite the rifling of the gun barrel. The preferred projectile may be of a small caliber although the technique may be applied to larger calibers. In a preferred embodiment, a projectile jacket uses a known structure that breaks apart on exiting the muzzle to permit release of an internal package. The preferred package includes a journal sleeve nested inside a bearing sleeve. Preferably both sleeves would be formed of a polymeric material having microencapsulated lubricants. In some embodiments, the bearing sleeve can be molded to the inside of the jacket. To lock the bearing sleeve in place, the bottom of the jacket can have one or more axially asymmetric concavities that prevent the bearing from slipping inside the jacket. In some preferred embodiments, either the bearing sleeve or the journal sleeve can have inter-sleeve projections that reduce the amount of surface contact between the sleeves. These projections reduce friction and allow the sleeves to rotate with respect to each other. Preferably, the two sleeves may be partially segmented to allow them to fold back petal-wise after firing. This arrangement can allow the load within the sleeves to be launched separately from the jacket. In some embodiments, the load may be a plurality of subloads such as flechettes, surrounded by buffering particles to keep the flechettes aligned during handling and firing. BRIEF DESCRIPTION OF THE DRAWINGS The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred, but nonetheless illustrative embodiments in accordance with the present invention, when taken in conjunction with the accompanying drawings wherein: FIG. 1 is an axial sectional view of the projectile according to the principles of the present invention; FIG. 2 is an axial sectional view of a journal sleeve in the projectile of FIG. 1. FIG. 3 is a back end view of the sleeve of FIG. 2; FIG. 4 is an axial sectional view of a journal sleeve that is an alternate to that of FIG. 2; FIG. 5 is a back end view of the sleeve of FIG. 4; FIG. 6 is an axial sectional view of a sleeve that is an alternate to that of FIG. 2; FIG. 7 is a back end view of the sleeve of FIG. 6. FIG. 8 is a back end view of the sleeve of FIG. 6, but modified to show a different projection pattern; FIG. 9 is a front end view of the sleeve of FIG. 2; FIG. 10 is a front end view of the sleeve of FIG. 2, but modified to have a different slit pattern; FIG. 11 is a front end view of the sleeves of FIGS. 4 and 6; FIG. 12 is a front end view of the sleeves of FIGS. 4 and 6, but modified to have a different slit pattern; FIG. 13 is an axial sectional view of a bearing sleeve in the projectile of FIG. 1; FIG. 14 is a back end view of the sleeve of FIG. 13; FIG. 15 is an axial sectional view of a sleeve that is an alternate to that of FIG. 13; FIG. 16 is a back end view of the sleeve of FIG. 15; FIG. 17 is a back end view of the sleeve of FIG. 15, but modified to show a different projection pattern; FIG. 18 is an axial sectional view of a sleeve that is an alternate to that of FIG. 13; FIG. 19 is a back end view of the sleeve of FIG. 18; FIG. 20 is a back end view of the sleeve of FIG. 18, but modified with a different projection pattern; FIG. 21 is an axial sectional view of a sleeve that is an alternate to that of FIG. 13; FIG. 22 is a back end view of the sleeve of FIG. 21; FIG. 23 is a front end view of the sleeves of FIGS. 13-22; FIG. 24 is a front end view of the sleeves of FIGS. 13-22, but modified to have a different slit pattern; FIG. 25 is a side view of the projectile of FIG. 1 mounted in a gun barrel shown partially and in section; and FIG. 26 is a view showing the projectile of FIG. 23 at the moment of launch and separation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a projectile 10 is shown with a jacket 12. The front of jacket 12 is designed to open or break apart to release its internal package upon existing the muzzle. This jacket is designed to handle the dynamic forces occurring during setback and firing and therefore can protect the internal package. In this embodiment, the internal package comprises a journal sleeve 18 nested within a bearing sleeve 34. Sleeve 34 has a pair of rear projections 38 that fit into corresponding concavities in the bottom of jacket 12. These projections 38 are not axisymmetric, but are a pair of diametric, hemispherical bosses. As such, projections 38 lock sleeve 34 in jacket 12 to prevent relative rotation between them. While the projections 38 tend to lock the bearing sleeve 34 in the jacket 12, in some designs a certain amount of slip between jacket 12 and sleeve 34 will be tolerated or desirable. Sleeves 18 and 34 are made of a polymeric material, preferably having a microencapsulated lubricant. Thus, sleeves 18 and 34 have the ability to relatively rotate. In the instance where projectile 10 is a caliber 0.50 mm projectile, the sidewalls of bearing sleeve 34 and journal sleeve 18 will be approximately 0.010 inch thick, while the base will be approximately 0.020 inch thick; although these dimensions may vary in other embodiments In this embodiment, the load 50 within sleeve 18 are anti-personnel/anti-material projectiles such as flechettes packed in buffering particles 52. The buffering particles may be material suitable for keeping the flechettes aligned as illustrated and acting as a shock absorber during handling and during firing. This design is more efficient since the package can be dispersed in the primary direction of a target; unlike an explosive munition in which the submunition are scattered and only a small percent are in a direct line with the target. While a plurality of flechettes are illustrated, the load could be instead a single projectile that does not require a high spin rate for aerodynamic stabilization. A mass stabilized projectile may be used. Referring to FIGS. 2 and 3, a generally, axially symmetric journal sleeve 18 is shown with a closed base and open front. The sleeve can be formed from a polymeric material and preferably include microencapsulated lubricant. Sleeve 18 is shown partially segmented by a plurality of slits 20 that may be 3 or 4 in number, although in alternate number of slits may be employed. In some embodiments, slits 20 need not go completely through the sleeve, but may be a narrowed rupture line that can tear apart after firing. The journal slits 20 allow the front of sleeve 18 to fold back into a plurality of petal segments. FIGS. 4 and 5 show a journal sleeve 21 similar to the foregoing sleeve, but modified to have eight journal bosses 22. The bosses are shown as external hemispherical projections, integrally molded with the material of sleeve 21. In this embodiment, the eight bosses are laid down in two circular patterns of four bosses each. Each circular pattern has bosses spaced equiangularly about the axis of the sleeve 21. Referring to FIGS. 6 and 7, the sleeve previously illustrated in FIG. 4 is modified and illustrated herein as sleeve 24 having additional pattern of four rear projections 26. In FIG. 8 an alternate pattern of 3 projections 28 are illustrated. Referring to FIGS. 9 and 10, a front view of the sleeve of FIG. 2 shows previously mentioned slits 20 arranged symmetrically at 90° intervals. In Figure 10, a front view of the sleeve of FIG. 2 is modified to show three slits 20A arranged symmetrically at 120° intervals. Referring to FIG. 11, the front view of the sleeves of FIGS. 4 and 6 is shown with a pattern of three slits 24c disposed symmetrically at 120° intervals. In FIG. 12, slits 24A are shown in a modified arrangement spaced symmetrically at 90° intervals. Referring to FIGS. 13 and 14, bearing sleeve 30 is shown as a generally axisymmetric sleeve with a closed base and an open front. Sleeve 30 is formed of a polymeric material with microencapsulated lubricants, similar to the previously described journal sleeve of FIG. 2. Also, sleeve 30 is shown with a plurality of bearing slits 32, which may pass through the entire thickness of sleeve 30 or in some embodiments be a narrowed rupture line designed to allow the front of sleeve 30 to fold backward into petal segments. Referring to FIGS. 15 and 16, the previously illustrated sleeve of FIG. 13 is shown modified as a sleeve 34 having a plurality of integrally molded, internal bearing bosses 36. In this embodiment four hemispherical bosses 36 are distributed equiangularly at 90° intervals. In some embodiments bosses 36 can be arranged as an annular internal ridge to provide support around a 360° locus. The rear of sleeve 34 is shown having a pair of hemispherical projections 38 for locking the position of sleeve 34. In FIG. 17, the projection pattern of FIG. 16 is modified to show three hemispherical projections 40. Referring to FIGS. 18 and 19, the sleeve previously illustrated in FIG. 13 is shown modified as a sleeve 41 having at its base an elongate projection 42, again for the purpose of locking the sleeve into position. In FIG. 20, the previously mentioned projection is modified into cruciform projection 44. Referring to FIGS. 21 and 22, the previously illustrated sleeve of FIG. 13 is shown modified to have a pair of rectangular projection 46. Also, internal bosses 48 are shown in a modified form. Referring to FIG. 25, projectile 10 is shown being fired through a gun barrel 16. Projectile 10 is shown having a jacket 12 that is designed to open or break apart along lines 14 to permit release of its contents upon exit from the muzzle. Jacket 10 is of a known design capable of withstanding the dynamic loads of setback and firing. Its structural rigidity is sufficient to keep its contents intact. As explained hereinafter, the slits 14 upon exiting the muzzle will allow the front segments of jacket 12 to fold back petal-wise to release its contents. To facilitate an understanding of the principles associated with the foregoing, the operation of the apparatus of FIG. 1 and 25 will be described in connection with FIG. 26. Projectile 10 is loaded into gun barrel 16 and fired in the usual fashion. Before firing the fit between the sleeves is snug but not tight. When fired through barrel 16, its rifling tends to spin jacket 12. Because projections 38 lock sleeve 34 to jacket 12, sleeve 34 spins as well. Advantageously, the spinning of sleeve 34 tends to drive its side walls outwardly to reduce the force between it and sleeve 18. Also, the centrifugal force tends to cause separation of the petal segments of sleeve 34 when leaving the muzzle. Since sleeve 18 and its load 50 have a certain amount of mass, load 50 does not tend to rotate with the sleeve 34. Instead, relative rotation occurs between sleeves 18 and 34. In instances where a bosses project between sleeves 18 and 34, the sleeves ride on the bosses and friction is correspondingly reduced. Upon leaving the muzzle, jacket 12 and bearing sleeve 34 will fold backwardly into the petal segment shown in FIG. 26. The journal sleeve 18 will fold in a similar fashion. At this time, load 50 is launched in the general direction of the target. Throughout the firing sequence, the buffering particles act as shock absorbers to maintain the relative position of the flechettes 50. After firing, the buffering particles are scattered and do not travel a significant distance. It is to be appreciated that various modifications may be implemented with respect to the above described preferred embodiment. For example, the caliber of the various components can be changed depending upon the load being fired. Furthermore, the load can be any type of load that may be fired by a gun. Furthermore, the materials of the sleeves can be other then polymeric and may be of any type of plastic, metal or other material suitable for firing. Also, the shape of the various projections can be altered depending upon the type of projectile, the expected forces etc. Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

A projecetile for firing in a gun barrel has a jacket and a load. A bearingleeve is mounted in the jacket and the jacket is of a different material than the bearing sleeve. A journal sleeve is mounted in the bearing sleeve to axially rotate therein. The load is mounted in the journal sleeve to rotate therewith. Thus angular rotation of the load with respect to the gun barrel is reduced.

CROSS-REFERENCE TO RELATED APPLICATION [0001] The present invention is a divisional of U.S. application Ser. No. 10/149,857, filed Oct. 15, 2002, entitled “RADIO SYSTEM WITH UNIVERSAL COMMUNICATION INTERFACE.” FIELD OF THE INVENTION [0002] The present invention relates to a radio system and particularly, but not exclusively, to a system employing what are commonly known as personal role radios as typically carried by members of the armed forces or organisations such as the police. Here there is often a requirement for an individual to have a personal role radio to permit two way communication. BACKGROUND OF THE INVENTION [0003] Conventional two way radios operate in either duplex or simplex mode, the duplex mode is similar to a telephone system where the receive and transmit paths are both open and both parties can speak to each other with no other requirement. [0004] The more common operation is simplex where the transmit path of each radio only works when the transmitter is keyed by the operation of a “press to talk switch” (PTT). The types of switch used vary and can be either part of a microphone as in the case of the hand held types in common use, or a switch box in a lead between the radio and a headset, as used in commercial and operational headsets. [0005] Operators often have to operate a radio transmit switch while using their hands to do other things and certain systems incorporate voice activation where the radio is switched at the detection of the users voice from the microphone. This technique is not reliable with some applications and the need for a switch actuated by the user is still the only reliable means of controlling the radio. SUMMARY OF THE INVENTION [0006] According to the present invention there is provided a radio system including a radio and a press to talk (PTT) switch which, when operated, sets the radio to a transmit mode, characterised in that the switch forms part of a switch unit which is supported on the radio by an interface arrangement allowing detachment of the switch unit from the radio. [0007] By employing the present invention it is possible to interchange switch units and radios. This is particularly advantageous in applications, for example with the Police or Military, where it enables one single switch unit type to be common to a number of applications. This simplifies provision of spares, the number of lead termination types required on auxiliary equipment, such as headsets, and the amount of training required for operators, for regardless of what radio they may be using as the control principles are the same. More importantly once an operative has become familiar with the use of one switch unit which can be fitted to any radio, there is less likelihood of incorrect PTT switch operation caused by being unfamiliar with an equipment type as may occur whilst the operative is concentrating on objectives other than operation of the radio. [0008] Preferably the system comprises a variety of radio types which can each receive a standard switch unit. Particular mountings maybe required for certain types of vehicle or for where a radio is to be worn by the operator. [0009] The switch unit will normally be mounted directly on the housing of the radio, which is particularly advantageous where the radio is a personal role radio carried, normally by being strapped, to an operative. Here the radio and switch unit may form one complete unit with no need for any auxiliary wiring between the two. A headset and lapel microphone or similar may be connected to the switch unit in the normal manner. [0010] An optional additional facility is the provision of a remote interface located away from the radio but connected thereto by a physical communication link, either a wire or optical fibre. This may be of particular advantage if the radio is for example a large radio mounted in a vehicle for this enables the radio to be mounted at any location within the vehicle. The operative may then have the switch unit mounted on its remote radio interface at a location convenient to the operative, or the radio interface may even be worn by the operative. [0011] In certain applications, particularly military applications, there is a requirement for a personal role radio to communicate locally by two way radio, but the operative may also need to be connected to a different radio network, for example a combat network radio. In this scenario the switch unit is particularly advantageous if arranged to be connected to a personal role radio by means of the radio interface and to be connected to a second radio by means of a wire or optical link. It is then particularly advantageous that the switch unit has two PTT switches mounted thereon, one associated with each radio network. [0012] In some applications it is required that there is no possibility of cross-communication between different radio networks. The switch unit may thus contain circuitry to ensure no cross-communication can occur between at least one transmission and one reception signal associated with different radio networks by closing one channel (normally a transmit channel when a receive channel is in use). [0013] The system of the invention may additionally comprise a wired remote PTT module having a PTT switch, which module is small relative to the switch unit, the switch unit having a connection for the wire to the remote PTT switch. This enables the function of the PTT switch of the switch unit to be operated remotely of the switch unit, enabling the remote PTT module and associated switch to be mounted at a location convenient to the operative, for example on the handlebars of a motorbike. [0014] As an alternative to, or in addition to, the small wired remote PTT module the system may further comprise a cordless remote PTT module comprising a PTT switch, the remote module additionally comprising a short range, relative to the radio, cordless transmitter. The switch unit then additionally comprises a receiver for receiving signals from the remote module to remotely activate the function of the PTT switch of the switch unit. This is particularly advantageous for no matter whether the switch unit is mounted to a personal role radio or to a remote radio interface, possibly mounted to a vehicle, the operative has the means of performing the switching function remotely by means of the remote module. The short range transmission may be infra-red but preferably is by way of a radio transmitter. [0015] Preferably where the switch unit has two PTT switches associated with two different radio networks the remote module comprises two PTT switches associated with the two radio networks. [0016] Advantageous the signal transmitted from the remote module comprises a code to which the receiver in the switch unit is responsive thereby avoiding inadvertent operation when a number of remote modules are operated by respective individuals in close proximity. [0017] The receiver in the switch unit is advantageously responsive to a variety of codes associated with different remote modules. This may be particularly advantageous where the switch unit is associated with an operative who may operate several pieces of equipment each fitted with a remote module. The operative can thus operate any piece of equipment associated with a remote module and effectively activate the PTT switch of his switch unit via the remote module associated with a respective piece of equipment. [0018] Advantageously the receiver has a ‘learn’ mode in which it can learn a code associated with a remote module. This is particularly advantageous if the operative loses a remote module, or a remote module is damaged, because the lost or damaged module can be replaced by a new module having a different pre-programmed code which can then be learnt by the receiver. It is preferable that the receiver learn the code of the module rather than the remote module learn any code associated with the receiver for in this way no receiver is required by the remote module as it only needs to transmit code. [0019] Preferably the switch unit of the system comprises a magnetically operated switch and the remote module comprises a magnet, the magnet and magnetically operated switch being arranged such that the magnetically operated switch is caused to adopt a ‘learn’ mode position when the remote module, including said magnet, is held in an appropriate position relative to the magnetically sensitive switch, in which position activation of the PTT switch on the remote module causes the switch unit to learn the code transmitted by the remote module. [0020] By pressing the PTT switch on the remote module a number of times or for period in excess of a predetermined period one or more codes can be removed from the UCI so that the receiver is no longer responsive to those codes. Typically such action would clear all the codes from the receiver which would then re-learn the desired code. BRIEF DESCRIPTION OF THE DRAWINGS [0021] One embodiment of the present invention will now be described by way of example only with reference to the accompanying figures of which: [0022] FIG. 1A is a perspective view of a personal role radio forming one part of a radio system constructed in accordance with the present invention; [0023] FIG. 1B is a perspective view of a switch unit or “universal communication interface” which fits onto the radio of FIG. 1A to form a system in accordance with the present invention; [0024] FIG. 2 is a perspective view of a remote radio interface; [0025] FIG. 3 shows the assembled apparatus of FIGS. 1B and 2 ; [0026] FIG. 4 shows the assembled apparatus of FIG. 1A and FIG. 1B with auxiliary components; [0027] FIG. 5 illustrates an alternative universal communication interface with self-contained speaker and microphone; [0028] FIG. 6 illustrates the various communications equipment that interfaces with the universal communication interface of FIG. 1B ; [0029] FIG. 7A schematically illustrates the primary components within the remote module illustrating FIG. 6 ; and [0030] FIG. 7B illustrates the primary components of the universal communication interface of FIG. 1B and FIG. 6 which relate to remote operation of the universal communication interface by means of the remote module of FIG. 7A . DETAILED DESCRIPTION OF THE INVENTION [0031] Referring now to FIG. 1 , a personal role radio is illustrated generally as 1 , having a casing 2 , a battery compartment cover 3 , operating controls 4 and 5 , and an end face constituting a radio interface 6 . The interface 6 , has a fitting slot 7 , fitting thread 8 and electrical interconnects 9 , 10 and 11 . [0032] The personal role radio 1 comprises an aerial, (which is internal on the embodiment illustrated), a transmitter and receiver by which it may send and receive radio signals. The personal role radio is designed to be carried by an operative and would typically be carried on a belt or could be mounted in close proximity to the operative, for example on a vehicle associated with the operative. [0033] The radio interface 6 is designed to receive the “universal communication interface” or “UCI” indicated generally as 12 in FIG. 1B . The UCI 12 comprises a stud not shown and screw 13 which co-operate respectively with fitting slot 7 and fitting thread 8 to hold the UCI housing 14 in position. The UCI 12 comprises a headset connector 15 , push to talk (PTT) buttons 16 and 17 respectively associated with two different radio networks and two slots, only one 18 of which is shown, for receiving optional cable connections. [0034] The switches 16 and 17 are depressed in order to talk to respective communication networks through respective radios, one button 16 is associated with the personal role radio 1 of FIG. 1A , while button 17 is associated with a external radio network, which may be a combat network radio where the radio system is employed in a military application. [0035] The universal communication interface comprises circuitry to ensure that when a signal is being received on one communication network the press to talk function controlled by the button associated with the other network cannot be activated. This ensures that a radio signal being received and transmitted to a user, possibly by means of a headset, cannot inadvertently be picked up by the open microphone and simultaneously transmitted on the other radio network. [0036] When the radio of FIG. 1A is mounted to the UCI of FIG. 1B and an appropriate headset or speaker/microphone are connected to the UCI there is formed a self-contained personal role radio which may be carried by an operative, the radio interfacing with the universal communication interface via contacts 9 and corresponding contacts (not shown) on the universal communication interface 12 . [0037] There are applications where it is not convenient for the operative to carry the personal role radio, or where the operative may wish to use another radio, perhaps mounted in a vehicle. Indeed the operative may wish to mount his personal role radio within a vehicle. This is facilitated by the remote radio interface 19 of FIG. 2 which is identical to the interface 6 on the personal role radio on FIG. 1A , but instead of being part of that personal role radio is now a stand alone interface which may be connected to another radio which could be mounted on board a vehicle, aircraft, boat etc, or a large man-pack infantry radio, by means of connection lead 20 . [0038] The remote radio interface 19 comprises the same physical and electrical connections as the interface 6 and thus the UCI can be mounted to the remote radio interface 19 as shown in FIG. 3 . Referring now to both FIG. 1B and FIG. 3 , slot 18 in the UCI 12 may receive a cable with contacts on a spade which connect to contacts 10 . A corresponding slot (not shown) on the other side of the UCI permits a similar cable with contacts to connect with the contacts 11 on the interface 6 or 19 . These additional leads are illustrated in FIG. 4 , lead 21 being connected and lead 22 shown disconnected in order to illustrate contact spade 23 which connects to contacts 11 of FIGS. 1A and 2 . [0039] In the arrangement shown in FIG. 4 , the UCI 12 is mounted on the personal role radio 1 but could equally be connect to the remote radio interface 19 of FIG. 2 , as shown in FIG. 3 . Lead 21 may be connected to an auxiliary radio depending on the application, whilst leads 22 connects remote switches 24 and 25 , corresponding to press to talk switches 16 and 17 to the UCI 12 . The additional switches 24 and 25 may be located at a position convenient to an operative for example, on the handlebars of a motorcycle or quad bike or on the stock of a rifle. This permits the radio to be operated without the operative needing to remove his hands from the controls of the vehicle or from a gun he his carrying. Alternatively, depending on the application, this function may be satisfied simply by having the UCI 12 mounted on the remote radio interface 19 as shown in FIG. 3 and having the complete unit then mounted at an appropriate location, either on a vehicle or perhaps on a chest holster worn by an operative. It will be realised that there are any number of permutations which a remote universal communication interface 12 permits. [0040] Referring now to FIG. 5 , there is illustrated a variation of the universal communication interface of FIG. 1B . Here UCI 26 incorporates a microphone 27 and speaker 28 such that it can be operated without a headset. In the embodiment illustrated there is only a single push to talk switch 29 but this is a matter of design choice. The UCI 26 interfaces with the personal role radio 1 of FIG. 1A , or the remote radio interface as illustrated in FIG. 2 , in exactly the same manner as the UCI 12 illustrated in FIG. 1B . [0041] Both UCI's 12 and 26 , illustrated respectively in FIG. 1B and FIG. 5 , incorporate a radio receiver, (which could equally be an infra-red receiver). The function of this receiver is described below with reference to FIG. 6 where, for illustrative purposes only, the UCI 12 of FIG. 1B is shown connected to a headset, illustrated generally as at 30 having headphones 31 and a microphone 32 located on a stalk which when worn by an operative is in front of the operatives mouth. [0042] In the embodiment illustrated in FIG. 6 the UCI 12 is mounted on the remote radio interface 19 previously described with reference to FIG. 2 . The radio system additionally comprises a cordless remote press to talk (PTT) module 33 having a PTT switch 34 thereon and a magnet 35 , located adjacent the wall of the casing 36 of the remote module 33 . The remote module 33 comprises a low power transmitter arranged such that operation of the PTT switch 34 causes a signal 37 to be transmitted to the UCI 12 which when received by the receiver (not shown) of the UCI 12 the UCI functions as though the PTT switch ( 16 ) had been depressed. [0043] The function of the remote module is described below in more detail with reference to FIGS. 7A and 7B , however it should be noted that although only one PTT switch 34 is illustrated on the remote module 33 , in order to simplify the description, the module 33 could comprise two switches corresponding to the switches 16 and 17 of the UCI if the module is desired to be used with a UCI designed to operate with two networks. [0044] Referring to FIG. 7A the remote module 33 is shown schematically to comprise a battery 37 connected by PTT switch 34 to transmit circuit 38 . When the switch 34 is depressed the battery is connected to the transmit circuit which retrieves a code from EPROM 39 . This code is effectively unique to the remote module and is transmitted in a signal via antenna 40 to receiving antenna 41 housed within the UCI 12 illustrated schematically in FIG. 7B , with the function of only one PTT switch 16 illustrated for clarity. [0045] Referring to FIG. 7B the PTT switch 16 connects the microphone 32 to the personal role radio 1 . (The communication path to the headphones 31 has been omitted for clarity). Although the headset is shown connected via UCI 12 to personal role radio 1 the radio could be any radio. The microphone 32 may be connected to the personal role radio 1 by means of switch 16 or by means of signal received by receiver 42 via antenna 41 . The receiver 42 when receiving the correctly coded signal closes switch 43 . It should be noted here that although FIG. 7 , and description thereof, talks about opening and closing switches and the switches are illustrated as being physical switches contained within the UCI 12 , in practice this function may be achieved electronically and indeed may be achieved by generating an appropriate signal to the transmitter contained within the radio 1 . [0046] In order that the receiver 42 may learn the code which the remote module 33 will transmit, the remote module 33 may be held adjacent the UCI 12 with magnet 35 adjacent a magnetically sensitive reed switch 44 in the receiver. With the magnet 35 adjacent the reed switch 44 , the reed switch closes setting the receivers circuit to a ‘learn’ mode. An operative depressing the PTT switch 34 of the remote module 33 causes the code stored therein to be transmitted from the remote module 33 to the receiver 42 , which code is then stored in memory in the receive circuit 42 and subsequently recognised as an appropriate code. [0047] The receiver 42 may learn a number of codes such that it is responsive to signals from a corresponding number of remote units. To reset the receiver and wipe out all stored codes the magnet is held adjacent the reed switch and the PTT switch 34 of the remote module 33 pressed five times in quick succession. The receiver circuit 42 is programmed to recognise this as a ‘clear all codes’ signal. Alternatively the receiver could be programmed to recognise a signal lasting longer than a set duration. [0048] It will be realised that apparatus in accordance with the invention may have any number of applications and the particular applications are outside the scope of the present specification. However for illustrative purposes a brief reference to one application of the invention is given below with reference to a rider of a police motorcycle. [0049] The police rider would typically have a personal role radio mounted upon his person complete with a headset and UCI, the UCI either being mounted directly to the radio or perhaps strapped to his chest. The advantage of this is that whether on the bike or dismounted the police carries his complete radio system with him. However whilst riding the bike it is not desirable to let go of the controls and therefore the remote module 33 may be mounted at a convenient location on the handlebars of the bike. Thus when the rider wishes to reply to a communication he can simply push the button 34 and speak into the microphone. On leaving the bike he leaves the remote module 33 on the bike but can communicate by pressing PTT button 16 on the UCI 12 . [0050] The rider may ride a number of bikes and a particular bike may be ridden by a number of riders. Here the rider can program the receiver of his UCI with the code of all the bikes or vehicles he rides (cars he drives) so that a remote module mounted on any one of those vehicles will operate his particular radio. When he gets on to a bike he has not ridden before, he simply places his UCI 12 adjacent the remote module 33 of that bike such that the code of that remote module is then stored in the receiver of his UCI. [0051] It would be possible for the remote module 33 to have a receiver and receive codes transmitted from the UCI, however this requires an extra receiver in the remote module 33 and transmitter in the UCI 12 . Also it will be realised that a learning mode may be generated other than by magnet 35 for example a screwdriver could be placed in a small hole to operate a switch equivalent to the magnet 35 operating reed switch 43 . [0052] The above describes one way in which the present invention may be employed. However numerous other implementations and applications will occur to those skilled in the art which are within the scope of the appended claims.

A radio system comprises a radio ( 1 ) having a transmit mode activated by a press to talk (PTT) switch ( 16 ) mounted on a universal communication interface ( 12 ) for mounting on a radio interface ( 6 ) associated with the radio ( 1 ). The radio interface ( 6 ) may or may not form part of the radio ( 1 ) and a plurality of radio interfaces may be provided for different applications, such that a standard universal communication interface ( 12 ) can be used with different types of equipment.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] None. STATEMENT REGARDING FEDERALLY SPONSORED-RESEARCH OR DEVELOPMENT [0002] This invention was made with Government support under Contract No.: NBCH 3039004 awarded by the Defense Advanced Research Projects Agency (DARPA). The United States Government has certain rights in this invention. INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC [0003] Not Applicable. FIELD OF THE INVENTION [0004] The invention disclosed broadly relates to the field of software updates and more particularly relates to the field of applying software updates in a virtual container. BACKGROUND OF THE INVENTION [0005] Virtualization technology has been gaining widespread commercial acceptance in recent years. Server virtualization allows multiple operating system (OS) stacks to share common hardware resources such as memory and CPU—it is generally implemented as a mediation layer that operates between the OS and the hardware. Application level virtualization technologies allow multiple application stacks to share a common OS namespace such as files and registry entries. It is generally implemented as a mediation layer that operates between the application processes and the OS. [0006] With server virtualization, an OS stack can be given the illusion that its required hardware resources are available exclusively for its use, whereas in reality the hardware resources may be shared by multiple OS stacks. With application virtualization, an application can be given the illusion that its files and registry entries are exactly where it expects them to be on the host machine, whereas in reality multiple application install images may be sharing those same locations in the namespace. [0007] The two kinds of virtualization technology (server virtualization and application virtualization) operate at different levels of the stack, and their value propositions are complimentary. Server virtualization enables encapsulation of the states of a complete OS+application software stack within a virtual server container, while application virtualization enables encapsulation of the state of an application stack only within a virtual application container. Both allow their respective containers to be deployed and managed as an appliance, ie., a pre-installed and pre-tested environment within a secure sandbox that is isolated from other stacks that share the same environment. This has significant commercial value from an IT management standpoint, because appliances provide greater robustness and security assurances than conventional install-based methods of deployment. [0008] Current practice for patching conventionally installed software is painful for system administrators who must apply the patch, test it and, potentially, roll back the changes. Preparation for potential rollback is particularly burdensome. Often multiple patches are available to be applied to the application with conflicting dependencies among the patches. Ideally, a system administrator might test several combinations of patches before settling on a suite to apply. [0009] Referring to FIG. 1 , there is shown the state of the art for applying patches to software applications by naïve users. First, the patch is applied to the application 1010 . Then, the application is run in production mode 1020 . There are problems with this approach: the patched application may not run, it may run and exhibit incorrect behavior, it may run and exhibit poor performance, and/or it may run and break other applications. While some of these failure modes may manifest immediately, some may not become apparent until after the patched application has been run for a considerable period of time. Recovering from such failures is seldom easy or painless. [0010] The state of the art for applying patches by more sophisticated users and systems administrators is depicted in FIG. 3 . Before the application is patched in step 3020 , the local state of the system is captured and saved in step 3010 . The patched application is first run in a testing mode 3030 . A decision is subsequently made as to whether the patched application is behaving acceptably 3040 . If so, the patched application is run in production mode 3050 . If not, the patched application is discarded 3060 , the saved state is restored 3070 , and the previous, unpatched, application is again run in production mode 3080 (rolled back). One skilled in the art will understand that, in testing mode, the input to the patched application will be structured so as to stress the various capabilities of the application without having significant effects that reach beyond the local state of the system that cannot easily be rolled back as part of the restoration step 3070 . [0011] Virtual Environment Background. [0012] A virtual execution environment enables an asset's install-time environment to be reproduced virtually while otherwise not isolating the asset from peer applications on a target machine. A framework is provided for intercepting interfaces above the operating system (e.g., Java class loading), enabling optimizations requiring semantic awareness not present at the OS level. The virtual environment provides isolation from the uncontrolled variability of target machines, particularly from potentially conflicting versions of prerequisite software. Skilled personnel assemble a self-contained software universe (potentially including the operating system) with all of the dependencies of an application, or suite of applications, correctly resolved. They then have confidence that this software will exhibit the same behavior on every machine, since a virtual machine monitor (VMM) will be interposed between it and the real machine. [0013] Consider a scenario in which several different applications produced by separate organizations need to be integrated on the same machine. Virtual machine monitors can help tame such conflicts by allowing each application's dependencies to be embedded in its private VM image. Assets (applications) are isolated from each other in the sense that each one sees its own unique resources—virtual files, directories, and system metadata—and not resources that are unique to some other asset. While assets cannot see any of the host machine's resources that were overlaid by their own virtual ones, they can see other local resources and can communicate with other programs running on the host machine through non-occluded portions of the local file system and local interprocessor communication (IPC). [0014] Without an effective mechanism for reducing redundancy between (as well as within) assets, the proliferation of virtual views would entail a prohibitive amount of space to store, and bandwidth to transport, many closely related assets (the “code bloat” problem). To address this difficulty, assets are partitioned into shards, variable-sized semantically determined “pages” that are the unit of transfer between a software repository and the host machine. Shards may correspond to files, semantically cogent portions of files, system metadata such as registry entries, or metadata used by the virtual machine monitor. Shards are freely shared across assets. Bitwise identical shards are given the same physical name (in shard storage) and are only stored once. FIG. 9 depicts a physical view versus a virtual view of software deployment. A reference to C from asset X.1 is mapped to a different shard (shown as shard C.1) than a reference to C from asset X.2 (shown as shard C.2) while references to A in either asset are mapped to the same shard. [0015] Shards help maintain an appropriately scaled working set as the repertoire of assets in use on a machine evolves over time. Most significantly, since they are semantically determined, they allow redundant parts of highly similar assets to be detected and shared transparently (while maintaining the illusion that each asset has its own copy). Thus, the duplication implied by the virtual view of an asset's evolution is not reflected in its physical storage manifestation. SUMMARY OF THE INVENTION [0016] Briefly, according to an embodiment of the invention a method for updating an application on a host system includes steps or acts of: installing an application on the host system; installing a virtual machine monitor on the host system, installing a first virtual container on the host system, wherein the first virtual container comprises at least one update to the application; and instantiating the first virtual container within the virtual machine monitor in a mode wherein the host system can be accessed but not modified and wherein instantiating the first virtual container includes applying, in the first virtual container, the update to the application and running the updated application in the first virtual container. The method may also include a step of confirming that the updated application runs properly. Optionally, the virtual container may be devirtualized. [0017] According to another embodiment of the present invention, a method for devirtualizing a virtual container includes steps of: copying a state of the virtual container into a host machine, or designated portion thereof, setting system and user environment variables on the host machine; examining files in the host system, or designated portion thereof, and the virtual application container; deleting the files that exist in the host system, or designated portion thereof, but not in the virtual application container; deleting files of the host system, or designated portion thereof, that have different contents from the files in the virtual container; copying files from the virtual container that do not exist in the host system, or designated portion thereof, to a file system of the host system. This may include copying keys into a Windows registry. The virtual container and the virtual machine monitor may then be discarded from the system. [0018] A system updating an application on a host system includes: at least one virtual machine monitor, at least one virtual container; at least one application; at least one update to the application; and a processor configured for carrying out the above method steps. The system may also include an input multiplexer configured for mediating access to the at least one virtual container; and an output analyzer configured for confirming that the updated application performed as expected. [0019] According to another embodiment of the present invention a computer program product embodied on a computer readable medium includes code that, when executed, causes a computer to perform the above method steps for updating an application in a host system. BRIEF DESCRIPTION OF THE DRAWINGS [0020] To describe the foregoing and other exemplary purposes, aspects, and advantages, we use the following detailed description of an exemplary embodiment of the invention with reference to the drawings, in which: [0021] FIG. 1 is a flowchart of a method for applying patches, according to the known art; [0022] FIG. 2 is a flow chart of a method of patch testing in a virtual container, according to an embodiment of the invention; [0023] FIG. 3 is a flow chart of a method of patch testing, according to the known art; [0024] FIG. 4 is a flow chart of a method according to an embodiment of the present invention; [0025] FIG. 5 is a flow chart of the method of devirtualization, according to an embodiment of the present invention; [0026] FIG. 6 depicts the nesting of virtual containers, according to an embodiment of the present invention; [0027] FIG. 7 is a simplified block diagram of tandem virtual containers in a host system, according to an embodiment of the present invention; [0028] FIG. 8 is a simplified block diagram of a host system configured to operate according to an embodiment of the present invention; and [0029] FIG. 9 is a simplified illustration of a virtual view versus a physical view of software deployment. [0030] While the invention as claimed can be modified into alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the present invention. DETAILED DESCRIPTION [0031] We describe a system and method using virtualization technology to update applications. In particular, we provide a new technique for testing and applying patches (or other updates) to conventionally installed applications. We deliver software patches in virtual containers. One or more patches (or other changes to existing software) are delivered in the virtual container. The virtual container may be a virtual application container or a virtual system container. [0032] The patches are tested before they are applied to the host computer. When some or all of the updated patches in the virtual container are applied (still within the virtual container), the virtual container contains the effects of applying the patch updates to a previously installed application (either conventionally installed on the host system or within another virtual container). When testing reveals the effect of the updates to be acceptable, the state of the host system is transformed to match that of the virtual container instance containing the installed updates. [0033] According to an embodiment of the present invention an asset is installed conventionally on a host machine. An update (patch), or other code modification, is delivered in a virtual container. A virtual machine monitor on the host system runs this container in a mode wherein the host environment can be accessed (read) but not modified (written). When code in the container attempts to modify the host environment a copy-on-write mechanism (known to those with knowledge in the art) is used to create the illusion within the container that the modification has taken place without contaminating the host environment. [0034] The patch is applied in the container resulting in a virtual container with the patched application that can be tested without affecting the environment on the host machine. Rollback can be achieved by simply discarding this instance of the container. Other mechanisms may be needed to prevent interactions with databases and other machines during testing from escaping containment. In some cases, the original and patched applications could be run in tandem with input replicated between the two instances and the output compared. [0035] When the system administrator is satisfied with the behavior of the patched application, the effects of the patch can be “devirtualized” into the host machine's environment. Devirtualization causes the host machine environment to be transformed to reflect the state of the virtual container. [0036] Several techniques may be used to test combinations of patches. A virtual container could be built to contain multiple patches, and a system administrator could create multiple instances of the container with different combinations applied in each. Or, different combinations of patches could be built into different virtual containers. Or, each container could possess a single patch, and the effect of applying two patches would be achieved by running one container inside another. [0037] According to an embodiment of the present invention, a working application is developed, installed and put into production. Any updates to the application are made and captured as a virtualized overlay. The changes or updates (the virtualized overlay) are then tested in a virtual container running instead of (or in tandem with) the production version. When the behavior of the modified application is deemed acceptable, the contents of the container are devirtualized onto the production machine. [0038] Referring to FIG. 2 there is shown an embodiment of the present invention as it might be used by naïve users. First a virtual machine monitor (VMM) is obtained and installed on the host system 2005 . Then a virtual container is obtained 2010 containing a patch to an application previously installed on the host computer. This container is configured to allow some or all of the state of the host machine to appear within the container, and to allow changes to be made to this state within the container, but to prevent such changes from affecting the state of the host machine (except such parts of the host machine used by the virtual machine monitor to support the execution of the container). The patch is then applied to the application in the container 220 . The container now has the patched application while the unpatched application remains intact on the host. [0039] The patched application is then run in production mode from within the virtual container 2030 . This solution is subject to the same failure modes as the process depicted in FIG. 1 (except that execution of the patched application in its container will not break other applications running on the host). However, full or partial recovery can be achieved by merely removing the container and restarting the unpatched application. One skilled in the art will readily see how to package steps 2005 , 2010 , 2020 , and 2030 so that the user will only need to indicate the application and the patch in order to run the patched application in a virtual container. The virtual container may be a virtual application container or a virtual system container. [0040] FIG. 4 shows how an embodiment of the invention might be used by a more sophisticated user such as a system administrator. Step 4010 is the same as steps 2005 and 2010 from FIG. 2 . Likewise, step 4020 is the same as step 2020 from FIG. 2 . Step 4030 differs from step 2030 only in that the application runs in testing mode rather than in production mode. [0041] After the patched application has been tested, a decision is made as to whether the patched application is behaving acceptably 4040 . If any problems were encountered, the container is discarded 4050 , and the unpatched application restarted in production mode on the host 4060 . [0042] Otherwise, if the patch test was successful, a selection 4070 must be made as to whether to: 1) run the patched application in production mode in the container 4080 ; or 2) apply the patch on the host machine 4090 , optionally discard the container 4100 , optionally discard the virtual machine monitor 4110 , and run the patched application on the host machine in production mode 4120 ; or 3) devirtualize the container 4130 , optionally discard the container 4100 , optionally discard the virtual machine monitor 4110 , and run the patched application in production mode on the host machine 4120 . One with knowledge in the art will also see that other methods resolving conflicts between the state of the host and that of the container could also be used within the spirit and scope of the invention. [0043] FIG. 5 depicts the process of devirtualization. First, files having different contents on the host, or a designated portion thereof, than in the container and files existing on the host, or designated portion thereof, but not in the container are deleted from the host, or designated portion thereof in step 5010 . Then, files that do not exist on the host, or designated portion thereof, but do exist in the container, are copied from the container to the host, or designated portion thereof in step 5020 . [0044] The files moved to the host from the virtual container are either: created in the virtual container or moved from the host, or designated portion thereof, and then modified (copy on write) when the patch was applied, or created in the virtual container or moved from the host, or designated portion thereof, and then modified (copy on write) while the patched application was being tested in the virtual container. One with knowledge in the art will understand how the operations on “files” in 5010 and 5020 could be performed on “Windows Registry Keys,” or “environment variables,” or any other units of state. This step may involve copying keys into a Windows registry (possibly overwriting the values of previously existing keys). These keys may originate from: application of the patch in the virtual container, modification of keys on the host system (copied on write into the virtual container) during patch application, or execution of the patch in the virtual container during testing either by direct key creation or by modification of the values of keys on the host machine, or designated portion thereof, (causing the modified values to be instantiated in the container by the virtual machine monitor's copy on write mechanism). [0045] Optionally, the container may be discarded in step 5030 . Optionally, the virtual machine monitor may be removed from the host 5040 , leaving the host in a state as if it had been conventionally patched as in FIG. 1 or 3 . [0046] FIG. 6 depicts the nesting of virtual containers. Techniques for running one virtual container within another date back to the IBM System 370 in the 1970's. The host computer is depicted as a box 6010 . Two virtual containers are depicted as boxes 6020 and 6030 within the box representing the host computer 6010 . Another virtual container 6040 is depicted as a box within the box 6020 representing one of the other virtual containers. One with knowledge in the art will see how multiple virtual containers can execute simultaneously and immediately on the same host machine. One with knowledge in the art will also see how one virtual machine can execute within another and how the levels of nesting need not have any fixed bound. [0047] FIG. 7 depicts two virtual containers running in tandem. The host computer 7010 contains two containers 7020 and 7030 . Access to the containers is intermediated by a mechanism 7040 that multiplexes input to each. Output from, and/or performance of, the containers is monitored by another mechanism 7050 . One with knowledge in the art will recognize how this arrangement can be used to determine that a patched application has the same behavior and/or performance as the unpatched application or that its behavior and/or performance differ in an expected way. It may be desirable to run two or more virtual containers with updated applications, possibly including one containing a “vanilla” update (an update which does not modify the application). One with knowledge in the art will understand that three or more containers could be similarly managed by mechanisms like those depicted in 7040 and 7050 . One with knowledge in the art will see that two or more containers could be spread over two or more computers in networked configuration. One versed in the art will understand that one or more host computers could be used instead of one or more of the containers. [0048] The method according to embodiments of the present invention can be performed on a fee basis for clients. Updates and test runs would need to be logged for billing purposes. Alternatively, a client may select to have access to the services by paying a monthly subscription fee. [0049] Referring to FIG. 8 , there is shown a block diagram of a host system 800 configured to operate according to an embodiment of the present invention. For purposes of this invention, computer system 800 may represent many types of computers, information processing system or other programmable electronic device, The computer system 800 may be a stand-alone device or networked into a larger system. [0050] The system 800 could include a number of operators and peripheral devices as shown, including a processor 802 , a memory 804 , and an input/output (I/O) subsystem 806 . The I/O subsystem 806 may be operatively connected to an input multiplexer 840 and an output analyzer 860 . The processor 802 may be a general or special purpose microprocessor operating under control of computer program instructions executed from a memory. The processor may include a number of special purpose sub-processors, each sub-processor for executing particular portions of the computer program instructions. Each sub-processor may be a separate circuit able to operate substantially in parallel with the other sub-processors. Some or all of the sub-processors may be implemented as computer program processes (software) tangibly stored in a memory that perform their respective functions when executed. RAM may be embodied in one or more memory chips. The memory may be partitioned or otherwise mapped to reflect the boundaries of the various memory subcomponents. [0051] The memory 804 represents either a random-access memory or mass storage. It can be volatile or non-volatile. The system 800 can also comprise a magnetic media mass storage device such as a hard disk drive. [0052] The I/O subsystem 806 may comprise various end user interfaces such as a display, a keyboard, and a mouse. The I/O subsystem 806 may further comprise a connection to a network such as a local-area network (LAN) or wide-area network (WAN) such as the Internet. Processor and memory components are physically interconnected using conventional bus architecture. Also shown here is a virtual machine monitor 880 operatively connected to the processor 806 . [0053] According to an embodiment of the invention, a computer readable medium, such as a CDROM 801 can include program instructions for operating the programmable computer 800 according to the invention. [0054] What has been shown and discussed is a highly-simplified depiction of a programmable computer apparatus. Those skilled in the art will appreciate that a variety of alternatives are possible for the individual elements, and their arrangement, described above, while still falling within the scope of the invention. Thus, while it is important to note that the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of signal bearing media include ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communication links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The signal bearing media make take the form of coded formats that are decoded for use in a particular data processing system. [0055] According to another embodiment of the invention, a computer readable medium, such as a CDROM can include program instructions for operating the programmable computer 800 according to the invention. What has been shown and discussed is a highly-simplified depiction of a programmable computer apparatus. Those skilled in the art will appreciate that other low-level components and connections are required in any practical application of a computer apparatus. [0056] Therefore, while there has been described what is presently considered to be the preferred embodiment, it will understood by those skilled in the art that other modifications can be made within the spirit of the invention. The above descriptions of embodiments are not intended to be exhaustive or limiting in scope. The embodiments, as described, were chosen in order to explain the principles of the invention, show its practical application, and enable those with ordinary skill in the art to understand how to make and use the invention. It should be understood that the invention is not limited to the embodiments described above, but rather should be interpreted within the full meaning and scope of the appended claims.

A method for updating an application on a host system includes steps or acts of: installing an application on the host system; installing a virtual machine monitor on the host system, installing a first virtual container on the host system, wherein the first virtual container comprises at least one update to the installed application; and instantiating the first virtual container under the virtual machine monitor in a mode wherein the host system can be accessed but not modified and wherein instantiating the first virtual container includes updating the installed application in the first virtual computer and running the updated application in the first virtual container. The method may also include a step of confirming that the updated application runs properly. Optionally, the virtual container may be devirtualized. A system for updating an application on a host system includes: at least one virtual machine monitor, at least one virtual container; at least one application; at least one update to the application contained within the at least one virtual container; and a processor configured for carrying out the above method steps. The system may also include an input multiplexer configured for mediating access to the at least one virtual container; and an output analyzer configured for confirming that the updated application performed as expected in at least one virtual container.

REFERENCE TO RELATED APPLICATION This application is related to U.S. patent application Ser. No. 07/217,480 filed on even date herewith; assigned to the same assignee hereof; and entitled Improved Variable Ratio Drive Mechanism, to H. Leonard. FIELD OF THE INVENTION This invention relates to variable ratio drive mechanisms and more particularly to an improved variable ratio drive mechanism particularly adapted for use with bicycles. BACKGROUND OF THE INVENTION Variable speed drives using chains and sprockets have been employed with bicycles for many years. The drawbacks of such systems are well known and are described in U.S. Pat. No. 4,030,373 to H. Leonard. Therein is disclosed a variable ratio transmission for bicycles which includes a plurality of movable sheave segments, with each sheave segment having a releasable toothed retaining means which normally retains the sheave segment at a fixed radial position in a toothed track. That structure is, essentially, a variable diameter pulley or sheave, whose diameter is adapted to be selectively adjusted by the rider. A flexible belt is wrapped around and engages different adjacent sheave segments to impart rotary motion to the drive mechanism. The relative position of each sheave segment in its toothed track is adjusted only when a sheave segment comes out of contact with the drive belt. The mechanism described in the '373 patent for locking each sheave segment into place after adjustment contains relatively small and highly stressed parts requiring close manufacturing tolerances. The setting mechanism is sensitive to both axial location and warpage. Locking surety also degrades somewhat with wear. In U.S. Pat. No. 4,530,676 to H. Leonard, an improved variable ratio drive mechanism is disclosed which also employs driving and driven sheaves, each of which is provided with a set of adjustable sheave segments. In that mechanism, individual sheave segments are one-piece, belt-loaded-locked units which engage saw-tooth shaped steps along associated trackways. The center line of each sheave segment is offset from a radial line so that the belt's force on each sheave segment applies an offset torque which forces the sheave segment's teeth into engagement with opposed saw tooth steps along one side of the trackway. When each sheave segment becomes free of the belt's force, it can be engaged by a shifter which causes it's teeth to move out of engagement with the track's steps. The sheave segment is then radially movable in either an outward or inward manner. In order to unlock the sheave segment's teeth from engagement, means are provided to cause a modest amount of rotation of a segment's teeth so that they can ratchet up or down relative to the track's steps. This design is not suitable for small sheave diameters and for applications involving relatively resilient belts which are subjected to grossly fluctuating driving tensions. Furthermore, the design is adapted only to a single direction drive. In U.S. patent application Ser. No. 140,232, filed Dec. 31, 1987 and entitled "Variable-Ratio Transmissions, Separately and In Bicycles" to H. Leonard, there is disclosed still another improved transmission of the type that includes sheave segments coupled together by a drive belt. That transmission employs a sheave segment locking mechanism which runs the full length of each disk track in the drive mechanism. The locking mechanism described therein is controlled by a fixed path cam whose action is unrelated to the radial position of the sheave. More specifically, the locking mechanism is released and removed from interaction with an individual sheave segment by a cam means which is operative only when the sheave segment is out of contact with the drive belt. Under those circumstances, the sheave segment is free floating and can be either moved inwardly or outwardly by a shift mechanism. In this mechanism, positive and consistent lock-up is dependent upon light springs and free fitting, cooperating parts. Relatively close tolerances are required and lock-up surety decreases with wear. Accordingly, it is an object of this invention to provide an improved variable ratio drive mechanism of simple design. It is a further object of this invention to provide an improved variable ratio drive mechanism which exhibits substantial resistance to wear and positive lock-up. It is another object of this invention to provide an improved variable ratio drive mechanism which is adapted to bidirectional operation. SUMMARY OF THE INVENTION In accordance with the above objects, the invention relates to an apparatus for positioning a bearing surface relative to a track. The invention, in one embodiment, includes a rotatably mounted drive mechanism which is provided with a plurality of radially oriented tracks. The drive mechanism preferably comprises a pair of opposed drive disks with colinear radial tracks having tooth-like formations arranged therein. A movable sheave segment is mounted in each toothed track. Each sheave segment is engaged by an endless belt when the drive mechanism traverses through a predetermined arc of rotation but is disengaged from the drive belt when outside the predetermined arc of rotation. Toothed means are associated with each sheave segment to provide a means for locking the sheave segment into place in the track. Wedge-cam locking means associated with each sheave segment are forced by belt pressure to rigidly bias the sheave segments' toothed means against the tooth-like formations in the track. Spring means are also provided to resiliently bias the toothed means into engagement with the track so that the sheave segments are lightly held in place even when out of engagement with the drive belt. DESCRIPTION OF THE DRAWINGS FIG. 1 is a right elevation of a typical bicycle equipped with a variable ratio drive mechanism embodying the invention. FIG. 2 is a right elevation of a variable ratio drive mechanism embodying the invention, a portion of which elevation has been broken away to show the internal arrangement of the sheave segments. FIG. 3 is a fragmentary exploded perspective of the variable ratio drive mechanism shown in FIG. 2 with the pedal somewhat rotated. FIG. 4 is a fragmentary side elevation showing the orientation of various portions of the sheave segment when it is engaged by a drive belt. FIG. 5 is a fragmentary side elevation showing a sheave segment when it is both out of engagement with the drive belt and in engagement with the gate cams associated with the shift gate. FIG. 6 is a section of a sheave segment with a modified bias arrangement. FIG. 7 is a section of a modified sheave segment which includes a pair of inverted, pivotally mounted locking blocks. It should be noted that none of the above drawings are drawn to scale and that the segments and tracks are purposely drawn larger than the rest of the assembly to more clearly describe the invention. DETAILED DESCRIPTION OF THE INVENTION U.S. Pat. Nos. 4,030,373, 4,530,676 and U.S. patent application Ser. No. 140,232 all to H. Leonard, each describe variable ratio transmissions which are usable with both bicycles and other apparatus. The disclosures of those patents and application are incorporated herein by reference. The variable speed drive mechanism to be described below is particularly adapted for inclusion with the transmission described in the aforementioned patent application Ser. No. 140,232--with appropriate modifications being made thereto to accommodate this invention. For instance, the following structural changes to the transmission shown in the aforementioned application would be necessary: The slot geometry has been altered and affects the structure of disks 82, 84, 110 and 112 (see FIGS. 13 and 19); the radial camming structure has been eliminated i.e. parts 95, 96, 97 and 146 (see FIGS. 13, 15, and 18); the segment design has been changed (see 46 and 48 in FIGS. 7 and 13); and the locking method changed (parts 90 and 94 eliminated in FIG. 13). Although the invention disclosed herein is described for use in a bicycle transmission, it is to be understood that it may be used in many other applications. In general, its application is for repositioning a bearing surface relative to a track. Referring now to FIG. 1, a bicycle 10, of the commonly accepted form, is shown and includes an adjustable ratio transmission 12. Transmission 12 provides the drive coupling between pedal crank 14 and rear wheel 16. A manual transmission ratio control 18 includes a pivoted finger actuated member that is conveniently operable by the person riding the bicycle. Ratio control 18 enables the rider to control transmission 12 via cable means 20. The details of shift control 18 are disclosed in copending U.S. patent application Ser. No. 140,232 and will not be further described herein. Suffice to say that the movement of shift control 18 one way or the other has the effect of conditioning transmission 12 to change its ratio in progressive steps using force exerted by pedal crank 14. So long as shift control 18 remains off center, continued operation of the pedal crank 14 will cause, within design limits, continuous step by step change in the transmission's ratio. Referring now to both FIGS. 1 and 2, transmission unit 12 includes a front drive mechanism which includes within housing 22, an adjustable diameter sheave that is operated by pedal crank 14. Transmission unit 30 is mounted in rear wheel 16 and further includes a rear drive mechanism which may include either a fixed or variable diameter sheave. Transmission 12 and its variable diameter pulley or sheave includes a plurality of radially adjustable sheave segments 32. An endless member or belt 34 may be in driving or driven frictional contact with each of sheave segments 32. When a selected transmission ratio is in effect, sheave segments 32 are locked at a fixed radius so as to enable the creation of the desired transmission ratio. Referring to FIGS. 2 and 3, drive mechanism 30 is further comprised of two, coaxial, spaced-apart disks 36 and 38 which form a unitary rotatable member coupled to pedal crank 14 and supported by roller bearings (not shown). Each of disks 36 and 38 is provided with a plurality of extended, toothed slots 42, which are radially aligned on disks 36 and 38 respectively. Each of slots 42 has formed thereabout on the outer surface of each of disks 36 and 38, indented areas 44 and 46 which encompass tooth-like formations such as teeth 48 and 50, respectively. In this embodiment, teeth 48 and 50 are oriented in parallel fashion; the sides of the teeth slant oppositely; meet at apexes and roots; and are aligned so that the roots and apexes thereof are directly opposite each other. Each sheave segment 32 is shown in detail in FIG. 3 and comprises four main components: cap 42, a wedge cam assembly 54, a left engagement block 56 and a right engagement block 58. In this embodiment, cap 52 is grooved on its upper surface so as to mate with the grooved surface of endless belt 34. It is to be understood that other belt configurations, such as flat belts, can be used and in such cases, cap 52 is not provided with a grooved surface, but rather with a surface which properly mates with the belt's surface. Cap 42 may also incorporate a roughened surface for added friction between itself and a flat belt or it may be toothed to engage teeth in a toothed belt (such as are used with synchronous or timing belts). Cap 52 is further provided with a downwardly extending portion 60 which mates with opening 62 in wedge cam assembly 54. Portion 60 may be fastened into opening 62 by any suitable means so as to make a single unitary assembly of cap 52 and wedge cam assembly 54. Cap 52 and wedge cam assembly 54 may also be made as one piece, if desired. Wedge cam assembly 54 comprises a bar 64 to which wedge cams 66 and 68 are rigidly attached. The upper portions of wedge cams 66 and 68 extend above cap 52 and act as guides for belt 34. The lower, bearing portions of wedge cams 66 and 68 perform the function of providing the force which locks a sheave segment 32 into position when cap 52 is in contact with drive belt 34. A pair of pins 70 (only one is shown) mate with holes 72 in wedge cam assembly 54 and provide anchor points for the attachment of springs 76 and 78, as will be hereinafter described. Left and right engagement blocks 56 and 58 are mirror images of each other. Each engagement block includes a pair of outer retaining plates 80 and 82 which are adapted respectively, to slidably move in indented areas 44 and 46 on each of disks 36 and 38. Extending from the outer surfaces of retaining plates 80 and 82 are nubbins 84 and 86 which provide two functions. First, they provide pivot points about which left and right engagement blocks 56 and 58 may pivot during the operation of a sheave segment. Second, they provide an outward extension adapted to be engaged by shift gates of a shifting assembly to enable radial movement of each sheave segment in either the outward or inward direction. Each of engagement blocks 56 and 58 is provided with a pair of toothed engagement surfaces 90 which are adapted, respectively, to interact with teeth 48 and 50 on disks 36 and 38. Each toothed engagement surface 90 is provided with an inward oriented follower surface 92 which is adapted to receive the lower most portions of wedge cams 66 and 68, respectively. The lowermost portions of left and right engagement blocks 56 and 58 include a pair of downwardly extending arm pairs 94 which are adapted to receive pins 96. Pins 96 form the lower anchors for springs 76 and 78, whose other ends are anchored to pins 70 in wedge cam assembly 54. When the entire structure of FIG. 3 is assembled, cap 52 is fixedly emplaced between wedge cams 66 and 68. Wedge cam assembly 54 fits between retaining plates 80 and 82 of left and right engagement blocks 56 and 58, respectively. The lateral dimensions of wedge cam assembly 54 are such as to allow it to move easily within retaining plates 80 and 82 without binding. Under such conditions, nubbins 84 form a pivot axis for left and right engagement blocks 56 and 58. The lower most surfaces of wedge cams 66 and 68 rest upon follower surfaces 92 and tend to force apart engagement blocks 56 and 58. In addition, springs 76 also tend to bias apart left and right engagement blocks 56 and 58. When left and right engagement blocks 56 and 58 are forced apart, toothed surfaces 90 are caused to mate with teeth 48 and 50 on disks 36 and 38, respectively. In this regard it should be noted that the outer most edges 98 of each of left and right retaining plates 80 and 82 are slanted slightly inwardly from top to bottom and are rounded at their uppermost extremities 81, and 83. When wedge cam assembly 54 forces the engagement blocks apart and edges 98 are forced towards the edges of indented areas 44 and 46, no engagement occurs therebetween. However, when retaining plates 80 and 82 are pivoted towards each other during shifting, rounded edges 81 and 83 ride on the edges of indented areas 44 and 46. FIG. 4 is a schematic drawing of a sheave segment with the outer retaining plates removed. Belt 34 bears down upon cap 52 which, in turn, imparts a downward force on wedge cam 66. Wedge cam 66 forces both the left and right engagement blocks 56 and 58 apart so as to cause toothed surfaces 90 to engage with teeth 48 and 50. Thus, the pressure exerted by drive belt 34 is seen to lock the sheave segment rigidly into place. Returning to FIG. 2, it will be recalled that in each of the above noted patents and patent application incorporated herein by reference (as well as in this invention), sheave segments 32 are adapted for movement along radial tracks 42 only when out of engagement with belt 34. Thus, for the entire arc of rotation of drive mechanism 30 during which sheave segments 32 are engaged by belt 34, they are not enabled for radial transfer of position. When, however, a sheave segment 32 is out of contact with belt 34, the force directed radially inward on cap 52 and wedge cam assembly 54 is released. Thus, the downward pressure is also eased which keeps apart left and right engagement blocks 56 and 58, respectively. Nevertheless, springs 76 and 78 maintain toothed surfaces 90 in relatively lighter contact with teeth 48 and 50 during this interval to prevent relative movement therebetween. As shown in phantom in FIG. 2, shift mechanism 100 is positioned to engage a nubbin 86 when its associated sheave segment 32 is out of contact with belt 34. As is fully described in copending U.S. patent application Ser. No. 140,232, the position of shift mechanism 100 is movable both inwardly and outwardly in relation to drive mechanism 30. Thus, when one of the cam surfaces of shift mechanism 30 contacts a nubbin 86, the associated sheave segment 32 is caused to ratchet either inwardly or outwardly depending upon the orientation of shift mechanism 100. This interaction is shown schematically in FIG. 5 wherein shift mechanism 100 has engaged nubbin 86 and caused toothed surfaces 90 to come out of engagement with teeth 48 and 50. As the sheave segment moves either radially inward or outward, the interacting toothed surfaces ratchet, one against the other until nubbin 86 no longer engages the cam surfaces of shift mechanism 100. Referring now to FIG. 6, there is schematically shown a modification to the sheave segments shown in FIGS. 2-5. Outer retaining plates 80 have been removed so as to enable better viewing of the modification. In lieu of having a pair of bias springs 76 and 78 to outwardly bias engagement blocks 56 and 58, a single compression spring 110 has been substituted which bears against arms 94 and biases toothed surfaces 90 into engagement with toothed tracks 44 and 50. A still further modification of sheave segment 32 is shown in FIG. 7. Here again, the outermost retaining plates have been removed to show the interior structure of left and right engagement blocks 112 and 114. In this case, nubbin 116 is mounted in the most radially inward orientation and the engagement blocks open outwardly. Wedge cam assembly 54 is again adapted to force left and right engagement blocks 112 and 114 apart in the directions shown by arrows 118 and 120 respectively. Here, toothed surfaces 90 engage with teeth 48 and 50 on disks 36 and 38 in the identical manner as aforestated. A tension spring 122 is provided between a shaft connecting the nubbins and wedge cam assembly 54. Tension spring 122 acts to bias wedge cam assembly 54 inwardly thereby tending to force left and right engagement blocks 112 and 114 apart to maintain the sheave segment in place even when it is not engaged by belt 34. It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.

The described invention includes a rotatably mounted drive mechanism which is provided with a plurality of radially oriented tracks. The drive mechanism preferably comprises a pair of opposed drive disks with colinear radial tracks having tooth-like formations arranged therein. A movable sheave segment is mounted in each track. Each sheave segment is engaged by an endless belt when the drive mechanism traverses through a predetermined arc of rotation but is disengaged from the drive belt when outside the predetermined arc of rotation. Toothed engagement blocks are associated with each sheave segment to provide a engagement blocks for locking the sheave segment into place in the track. A wedge cam is associatd with each sheave segment and is forced by belt pressure to rigidly bias the sheave segemnts' toothed engagement blocks against the tooth-like formations in the track. Spring(s) are also provided to resiliently bias the toothed engagement blocks into engagement with the track so that the sheave segments are lightly held in place even when out of engagement with the drive belt.

BACKGROUND OF THE INVENTION This invention relates to a multi-part collet for a blind riveting tool and a blind riveting tool incorporating a collet. The invention is also applicable to other tools in which rods or pins are gripped intermittently by means of a collet. One commercially successful design of a blind riveting tool possesses a jaw mechanism in which the mandrel of the rivet is gripped by a multi-part collet which is spring biased to grip the mandrel. The collet is housed within a tubular member whose bore is tapered and the outer surface of the collet is provided with corresponding tapers so that a different sized mandrel can be accepted by relative adjustment of the position of the collet within the tubular housing. Such collets are normally provided in two parts and the inner surfaces of the collet formed with transverse indentations or ridges in order to provide a better gripping surface. A disadvantage of the existing design of collet is that when a large run of one particular diameter rivet is used, the area of gripping surface becomes clogged with swarf from the rivet mandrels, even after a relatively short time of such use, and the tool begins to slip. U.S. Pat. No. 3,363,445 goes some way toward solving this problem by providing a multi-part collet whose collet parts have stepped ridged gripping surfaces provided with V-shaped grooves. Although these V-shaped grooves help remove swarf, they do not prevent its formation. Thus, as the serrations at the points of contact with the mandrel of a blind rivet are tangential, the contact area is relatively large and so a relatively low contact pressure is generated. This in turn leads to slippage and generation of swarf which eventually clogs up the gripping surfaces. SUMMARY OF THE INVENTION The present invention provides a multi-part collet for a blind riveting tool, wherein the internal surface of each part of the collet is provided with at least one longitudinal groove. Advantageously, that portion of the internal surface of each collet part which, in use, forms a gripping surface for the mandrel of a rivet, is formed with a plurality of transverse ridges. Preferably, the channel or each groove of each collet part extends over the entire length of said ridged portion. The grooves in the collet parts reduce the contact area between the collet and the mandrel thereby increasing the effective contact pressure between the mandrel of a blind rivet and the collet so that the collet bites more deeply into the mandrel. Consequently, the chance of slippage between the collet and the mandrel is reduced, which enables far longer runs of use of the tool without the necessity of cleaning or replacing the collets. The problem of slippage between the jaws and the mandrel is most pronounced in the case of small rivets since the amount of force which can be applied to the mandrel is limited to that needed to upset the rivet. As a consequence of reducing the contact area, the same force results in greater penetration of the mandrel by the collet, leading to reduced slippage and less swarf creation. The invention also provides a blind riveting tool incorporating a jaw mechanism provided with a multi-part collet as defined above. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: FIG. 1 is a part-sectional elevation of the jaws and associated parts of a blind riveting tool with a rivet in place in the jaws; FIG. 2 is an elevation of one part of a two-part conventional collet; FIG. 3 is an end view of the two-part collet in FIG. 2; FIG. 4 is an elevation of one part of a two-part collet constructed in accordance with the invention; and FIG. 5 is an end view of the completer two-part collet shown in FIG. 4. DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. 1 of the accompanying drawings, the jaws of the riveting tool are contained within a tubular housing 1 which is fixed at one end of one of the handles 2 of the tool. The jaw assembly of the tool is received within the housing 1, the jaw assembly comprising a member 3 which is pivotally mounted by a pivot 4 on the other handle 5 of the tool. The member 3 contains a longitudinal bore 6 housing a two-part collet 7, 7'. The forward end of the bore 6 is formed with a taper as shown and the external surfaces of the collet 7, 7' are formed with corresponding tapers. It will thus be appreciated that the collet 7, 7' is able to receive the mandrels 8 of blind rivets of different diameters according to the extent by which the nose of the collet extends out of the bore 6 in the member 3. The collet 7, 7' is urged outwardly by a plunger 9 and a coil spring 10 acting between the plunger and the pivot 4. A nipple 11 is screwed into the nose of the housing 1 and has a bore therethrough which is appropriate to the size of the mandrel 8 of a blind rivet 12. Usually, the riveting tool is sold with two or more nipples 11 having bores of different diameters for accepting rivets of different sizes. In use, the handles 2 and 5 of the blind riveting tool are pulled together as indicated by the arrows and this action upsets the end of the rivet remote from the tool causing riveting together of plates 13 and 14. One known form of collet is shown in FIGS. 2 and 3 from which it will be seen that the internal surface of the collet parts are formed with a grooved transverse pattern 15 of sharp ridges which enable the parts of the collet to grip a rivet mandrel. It will be appreciated that the gripping action performed by the collet will be concentrated in different parts of the grooved area for different sized rivets and an extended run of riveting work using a particular sized rivet will cause the grooved area of the collet in these parts to be clogged with swarf. A collet constructed in accordance with the invention is shown in FIGS. 4 and 5 from which it is apparent that the internal faces of the collet are formed with a channel or groove 16 which divides a similar pattern of ridges into two ridged areas 17 and 18. Each groove 16 is shaped as is shown in FIGS. 4 and 5 and thus has a profile which is substantially like that of a "square wave" form. The formation of the grooved area in this way reduces the area of contact between the collet and the mandrel and provides areas of point contact between the collet and the mandrel in the areas indicated by the reference numerals 20 in the boundary between the channels 16 and the ridged areas 17 and 18. This arrangement has the effect of increasing the effective contact pressure between the collet and the mandrel, thus enabling the collet to penetrate and grip the mandrel more deeply and therefore grip it more securely. As a result there is less tendency for slip to occur between the jaws and the mandrel during upsetting of the rivet and the generation of swarf is consequently greatly reduced, thereby enabling the tool to be used for greater runs without being cleaned or the collets changed. Moreover, any swarf generated can escape along the grooves 16 which further prevents build up of swarf and further increases the length of runs which the tool can do without changing or cleaning the collets. The collets may be produced by any suitable method, for example, machining or casting and the ridged areas and channels or grooves may be formed by pressing or machining. Normally the collets are given a final case hardening treatment. It will be appreciated that the collets may be formed with more than one channel or groove and that the invention is applicable to all power and hand operated tools where a collet is provided for firmly gripping a mandrel or similar pin.

A blind riveting tool incorporates a jaw mechanism provided with a multi-part collet. The jaw mechanism includes a generally tubular member whose bore tapers towards that end of the mechanism through which enters the mandrel of a rivet. The internal surface of each part of the collet is provided with a longitudinal groove.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an automatic transfer apparatus for a liquid crystal display (LCD) device and a method for sensing obstacle using the same, and particularly, to an automatic transfer apparatus for an LCD device which is capable of preventing a damage on a structure of an automatic transfer apparatus due to an obstacle by mounting a sensing member which is mounted at a bottom surface of the automatic transfer apparatus to sense the obstacle on the bottom, and by previously checking an existence of the obstacle. [0003] 2. Background of the Invention [0004] Development of information society has gradually enhanced requirements for various types of display devices. Among various types of flat panel display devices such as liquid crystal displays (LCDs), plasma display panels (PDPs), electro luminescent displays (ELDs), field emission displays (FEDs), and the like LCDs are spotlighted the most to continue be developed as monitors for TV sets and desktop computers as well as monitors for notebook computers. [0005] The LCD device may broadly be divided into LCD panels for displaying images and a driving unit for applying a driving signal to the LCD panels. [0006] As shown in FIG. 1 , a related art LCD panel includes first and second substrates 1 and 2 which are bonded to each other with a certain space therebetween, and a liquid crystal layer 3 injected between the first and second substrates 1 and 2 . [0007] Here, the first substrate 1 (i.e., a thin film transistor (TFT) array substrate) includes a plurality of gate lines 4 arranged in one direction by a certain interval therebetween, a plurality of data lines 5 arranged by a certain interval therebetween in a direction perpendicular to each gate line 4 , a plurality of pixel electrodes P formed in a matrix shape at each pixel region defined at an intersection between the gate lines 4 and the data lines 5 , and a plurality of TFTs which are switched by a signal from the gate line 4 to transfer a signal from the data line 5 to each pixel electrode P. [0008] Furthermore, the second substrate 2 (i.e., a color filter substrate) includes a black matrix layer 7 for preventing light from being transmitted to regions rather than the pixel regions, R, G and B color filter layers 8 for rendering color and a common electrode 9 for implementing images. Here, the common electrode 9 may be formed on the first substrate 1 in an LCD device employing a horizontal electric field mode. [0009] The LCD device having such structure is fabricated by processes for fabricating a TFT array on the first substrate 1 , fabricating a color filter layer on the second substrate 2 , bonding the first and second substrates 1 and 2 to each other, injecting a liquid crystal between the bonded substrates 1 and 2 and sealing the liquid crystal, testing and repairing each LCD panel in which the liquid crystal has been injected, and mounting a back light or the like in each LCD panel with a good quality and mounting a driving circuit to fabricate a liquid crystal display module. [0010] The substrates undergoes such various processes to completely be the LCD device. The substrates are transferred to devices which perform each process by use of an automatic transfer apparatus. [0011] With reference to FIGS. 2 and 3 , explanation will now be given for a related art automatic transfer apparatus used to transfer the substrates to the devices for performing each process upon fabricating an LCD device. [0012] FIG. 2 is a schematic view showing a related art automatic transfer apparatus having a cassette. [0013] FIG. 3 is a schematic view showing the related art automatic transfer apparatus having the cassette, which shows a case that there is an obstacle on a movement direction. [0014] Referring to FIG. 2 , a related art automatic transfer apparatus 10 includes a mounting unit 15 for placing a cassette 31 in which a plurality of substrates are received in order to perform each process, and a moving unit 11 disposed at a bottom of the mounting unit 15 and moving within a designated interval, namely, moving toward each processing device by use of rotational movement members 13 . A distance T 1 is a height between the outer bottom surface 41 and the lower portion of the moving unit 11 . The mounting unit 15 of the automatic transfer apparatus 10 has a robot arm 21 which is used to load the cassette 31 which is positioned at an input port (not shown) and an output port (not shown) of a stoker (not shown) directly on the mounting unit 15 or to unload the cassette 31 which has been loaded on the mounting unit 15 to the stoker. [0015] In a state that the automatic transfer apparatus 10 is moved toward each processing device in order to perform each process, the cassette 31 which has been loaded on the mounting unit 15 by the robot arm 21 or the cassette which is placed at the input port or output port is moved to each processing device or to the stoker. [0016] However, as shown in FIG. 3 , it is impossible for the automatic transfer apparatus 10 according to the related art to sense an obstacle 51 on the bottom out of the range in which a front of the obstacle 51 can be sensed. Here, T 2 is a thickness of the obstacle 51 . [0017] Therefore, impurities come into the bottom of the automatic transfer apparatus 10 , which causes interference with a lower structure of the automatic transfer apparatus 10 , resulting in problems in devices. That is, when an obstacle which is not sensed at a bottom of a movement detecting sensor or the moving unit is sucked into the bottom of the automatic transfer apparatus, damages may occur on the bottom structure of the automatic transfer apparatus. SUMMARY OF THE INVENTION [0018] Therefore, an object of the present invention is to provide an automatic transfer apparatus for a liquid crystal display (LCD) device and a method for sensing obstacle using the same capable of preventing a damage on a structure of an autom atic transfer apparatus by mounting a device for sensing an obstacle on a bottom of the automatic transfer apparatus. To achieve these and other advantages and in accordance with the purpose of the pr esent invention, as embodied and broadly described herein, there is provided an aut omatic transfer apparatus for a liquid crystal display device comprising: a mounting u nit; a moving unit disposed at the mounting unit; a sensing member disposed at the moving unit for sensing an obstacle; and an alarm signal unit for generating alarm signal. [0019] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provide d a method for sensing obstalcle using an automatic transfer apparatus for a liquid cr ystal display device comprising: providing a mounting unit; providing a moving unit disposed at the mounting unit; disposing a sensing member at the moving unit for se nsing an obstacle; and disposing an alarm signal unit to generate alarm signal. [0020] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0021] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. [0022] In the drawings: [0023] FIG. 1 is an exploded perspective view showing a part of a related art LCD panel; [0024] FIG. 2 is a schematic view showing a related art automatic transfer apparatus in which a cassette is mounted; [0025] FIG. 3 is a schematic view showing the related art automatic transfer apparatus in which the cassette is mounted, which shows a case that there exists an obstacle on a movement direction; [0026] FIG. 4 is a schematic view showing an automatic transfer apparatus for an LCD device according to an one embodiment of the present invention; [0027] FIG. 5 is a lateral view showing the automatic transfer apparatus according to the one embodiment of the present invention, which shows an obstacle sensing member. [0028] FIG. 6 is a schematic view showing an obstacle sensing member mounted at a bottom portion of the automatic transfer apparatus according to the one embodiment of the present invention; and [0029] FIG. 7 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to the one embodiment of the present invention. [0030] FIG. 8 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to an another embodiment of the present invention. [0031] FIG. 9 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. [0032] FIG. 10 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. [0033] FIG. 11 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0034] Description will now be given in detail of the present invention, with reference to the accompanying drawings. [0035] Hereinafter, an automatic transfer apparatus for an LCD device according to the present invention will be explained in detail with reference to the attached drawings. [0036] FIG. 4 is a schematic view showing an automatic transfer apparatus for an LCD device according to an one embodiment of the present invention, and FIG. 5 is a lateral view of the automatic transfer apparatus according to the one embodiment of the present invention, which shows an obstacle sensing member. [0037] FIG. 6 is a schematic view showing an obstacle sensing member at a bottom of the automatic transfer apparatus according to the one embodiment of the present invention. [0038] FIG. 7 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom of the automatic transfer apparatus according to the one embodiment of the present invention. [0039] As shown in FIGS. 4 and 5 , an automatic transfer apparatus 100 according to the present invention includes a mounting unit 115 for placing a cassette 141 in which a plurality of substrates are received in order to perform each process, and a moving unit 111 disposed at a lower portion of the mounting unit 115 and moving within a designated interval (section), namely, toward each processing device, by rotational movement members 113 . [0040] Furthermore, the mounting unit 115 of the automatic transfer apparatus 100 is provided with a robot arm 131 , which is used to load the cassette 141 placed at an input port (not shown) or an output port (not shown) of a stoker (not shown) to the mounting unit 115 or to unload the cassette 141 loaded on the mounting unit 115 to the stoker (not shown). [0041] In a state that the automatic transfer apparatus 100 is moved toward each processing device by virtue of the movement of the automatic transfer apparatus 100 in order to perform each process, the cassette 141 which has been loaded on the mounting unit 115 by the robot arm 131 or the cassette which is placed at the input port or output port is moved to each processing device or the stoker. [0042] A sensing member is provided within the moving unit 111 of the automatic transfer apparatus 100 . The sensing member includes two tape sensors 121 and 123 and an obstacle sensing bar 125 . The one tape sensor 123 of the two tape sensors 121 and 123 is coupled to the obstacle sensing bar 125 . One end of the obstacle sensing bar 125 is protruded downwardly to outer bottom surface 151 by a predeter mined distance T 3 . The distance T 3 is a height between the outer bottom surfa ce 151 and the end portion of the obstacle sensing bar 125 . Further, the automatic transfer apparatus 100 includes an alarm signal unit (not shown) for generating alarm sigal when the obstacle is sensed by the sensing member. [0043] As shown in FIGS. 5 , 6 and 7 , the obstacle sensing bar 125 is protruded enough to sense an obstacle 161 having a thickness T 2 smaller than a height T 1 between the moving unit 111 of the automatic transfer apparatus 100 and the outer bottom surface 151 . The obstacle sensing bar 125 is protruded downwardly to outer bottom surface 151 . And the obstacle sensing bar 125 maybe incline in a forward or backward direction. The obstacle sensing bar 125 is configured to be pushed back when it is contacted with the obstacle 161 . When the obstacle sensing bar 125 is moved by being pushed back by the obstacle 161 , the tape sensor 123 coupled to the obstacle sensing bar 125 is simultaneously moved in a direction opposite to that of the obstacle sensing bar 125 , to be in contact with the other tape sensor 121 corresponding thereto. [0044] Hence, as shown in FIG. 7 , when the automatic transfer apparatus 100 is moved forwardly, if the obstacle 161 placed at the front area of the automatic transfer apparatus 100 is in contact with the obstacle sensing bar 125 , the obstacle sensing bar 125 is pushed back by the obstacle 161 . Then the tape sensor 123 coupled to the obstacle sensing bar 125 is moved in the opposite direction to that of the obstacle sensing bar 125 to be in contact with the other tape sensor 121 . The tape sensors 121 and 123 which have been contacted to each other start to be operated, thereby giving the automatic transfer apparatus 100 to a pause and operating an alarm by the alarm singal unit (not shown). [0045] Afterwards, an operator removes the obstacle 161 sensed at the bottom of the automatic transfer apparatus 100 to continue to perform the operation. [0046] Meanwhile, another embodiments of the present invention is described as follows. [0047] FIG. 8 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to an another embodiment of the present invention. [0048] FIG. 9 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. [0049] FIG. 10 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. [0050] FIG. 11 is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. [0051] As shown in FIG. 8 , a sensing member according to an another embodiment of the present invention includes two tape sensors 221 a and 221 b spaced apart from each other and an obstacle sensing bar 225 coupled to a tape sensor portion 223 . Accordingly, the tape sensor portion 223 coupled to one of two tape sensors 221 a and 221 b. [0052] Accordingly, one of the tape sensors 221 a and 221 b and the sensor portion 223 which have been contacted to each other start to be operated, thereby giving the automatic transfer apparatus to a pause and operating an alarm by the alarm signal unit (not shown). [0053] Afterwards, an operator removes the obstacle 261 sensed at the bottom of the automatic transfer apparatus to continue to perform the operation. [0054] As shown in FIG. 9 , a sensing member according to further another embodiment of the present invention includes tape sensors 321 and 323 is in contact with each other and an obstacle sensing bar 325 coupled to a tape sensor 323 . Accordingly, when the obstacle sensing bar 325 is pushed back by the obstacle 361 , the tape sensor 323 is not contacted with the tape sensor 321 . [0055] Accordingly, the tape sensors 321 and 323 have been not contacted to each other start to be operated, thereby giving the automatic transfer apparatus to a pause and operating an alarm by the alarm singal unit (not shown). [0056] Afterwards, an operator removes the obstacle 361 sensed at the bottom of the automatic transfer apparatus to continue to perform the operation. [0057] As shown in FIG. 10 , a sensing member according to further another embodiment of the present invention includes a tape sensor 421 , and a obstacle sensing bar 425 spaced apart from the tape sensor 421 . Further, the obstacle sensing bar 425 includes another tape sensor portion 425 a which is in contact with the tape sensor 421 . The obstacle sensing bar 425 and the another tape sensor 425 a comprise a single body. [0058] Accordingly, the tape sensors 421 and 425 a have been contacted to each other start to be operated, thereby giving the automatic transfer apparatus to a pause and operating an alarm by the alarm singal unit (not shown). [0059] Afterwards, an operator removes the obstacle 461 sensed at the bottom of the automatic transfer apparatus to continue to perform the operation. [0060] As shown in FIG. 11 , a sensing member according to further another embodiment of the present invention includes a obstacle sensing bar 525 . The obstacle sensing bar 525 has a sensor function for sensing the obstacle. [0061] Accordingly, when the obstacle sensing bar 525 senses the obstacle 561 , thereby giving the automatic transfer apparatus to a pause and operating an alarm by the alarm singal unit (not shown). [0062] Afterwards, an operator removes the obstacle 561 sensed at the bottom of the automatic transfer apparatus to continue to perform the operation. [0063] As aforementioned, several effect can be expected by use of the automatic transfer apparatus for the LCD device according to the present invention. [0064] Regarding the automatic transfer apparatus for the LCD device according to the present invention, the sensing bar capable of sensing the obstacle is mounted at the automatic transfer apparatus. Accordingly, the sensing bar can be used to easily sense and remove the obstacle while moving the automatic transfer apparatus, whereby such small obstacles which have not been detected can be sensed to accordingly be possible to protect the lower structure of the automatic transfer apparatus from being damaged due to the small obstacles. [0065] Hence, upon using the automatic transfer apparatus according to the present invention, the obstacles can previously be detected to make the automatic transfer apparatus pause, thereby ensuring high stability of the automatic transfer apparatus. [0066] As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.

An automatic transfer apparatus for a liquid crystal display device comprising a mounting unit for placing a cassette in which a plurality of substrates are received, a moving unit disposed at a lower surface of the mounting unit and moving within a designated interval or section, and a sensing member mounted in the moving unit for sensing an obstacle, wherein the sensing member for sensing an obstacle at a bottom is disposed at the lower surface of the automatic transfer apparatus so as to enable a previous checking an existence of the obstacle, thereby preventing a structure of the automatic transfer apparatus from being damaged due to the obstacle.

FIELD OF THE INVENTION This invention relates to ready-to-assemble components having brackets attached thereto and method to use brackets to easily assemble components, such as furniture. BACKGROUND OF THE INVENTION Assembling furniture is ordinarily complicated. Present technology for assembling furniture is labor and part intensive. Presently, a piece of furniture will have many component parts and requires several tools for assembly. Moreover, with present technology, assembly of furniture usually requires more than one person. Other ready to assemble furniture systems utilize location dependent brackets that multiply the effort needed to assemble the furniture components and that intensify the complexity of the process. Presently, most furniture is assembled by the seller because of the complexity of assembling. Thus, furniture is handled fully or most fully assembled which creates bulky cargo that takes up a considerable amount of space and is difficult to transport. Additionally, when one part of a piece of furniture is damaged, the entire product must be returned instead of the damaged part. For example, when the frame of the arm of a couch is defective, the entire couch must be returned. Regarding other ready-to-assemble furniture systems for furniture, all entail many component parts, are not stable and require considerable time to assemble. See e.g., Cwik U.S. Pat. No. 4,459,920 and Boycott, et al., U.S. Pat. No. 5,671,974. BRIEF SUMMARY OF THE INVENTION This invention provides a bracket assembly for interconnecting components made of a receiving bracket and an engaging bracket. The engaging bracket is made of an elongated riser having an inner surface and an outer surface. A plurality of flanges extend from the elongated riser to form a line of intersection. The elongated riser is configured to extend beyond the plurality of flanges to form a cantilevered projection. The cantilevered projection is made of a first portion and a second portion. The first portion extends along the line of intersection. The receiving bracket is made of a riser having an inner surface and an outer surface and a plurality of flanges. The first portion of the cantilevered projection of the engaging bracket is configured to contact the inner surface of the receiving bracket. The plurality of flanges preferably include an aperture sized to receive an attachment means. In one embodiment, the elongated riser is made of two spaced apart vertical members and a top member forming a hollow internal section. The bracket assembly of this invention is made of two main parts: a receiving bracket and an engaging bracket. In the preferred embodiment, the receiving bracket is made of a riser that is formed from two spaced apart vertical members connected with a receiving top member. The spaced apart vertical members and top member form the hollow internal section of the receiving bracket. At least one flange, but preferably to two coplanar flanges, extend perpendicularly from the vertical members. The flange preferably includes at least one aperture to receive an attachment means. The aperture allows the receiving bracket to be fixedly attached to a component. The second main part of the bracket assembly is an engaging bracket. In the preferred embodiment, the engaging bracket is made of an elongated riser that is formed from two spaced apart vertical members connected with an engaging top member. At least one flange, but preferably two coplanar flanges, perpendicularly extends from one of the vertical members and has at least one aperture. A portion of the engaging top member projects beyond the at least one flange to form a cantilevered projection. The cantilevered projection is sized to fit in the receiving internal section of the receiving bracket. The inner surface of the receiving bracket is configured to contact the outer surface of the engaging bracket elongated riser. In the preferred embodiment, the receiving bracket has an aperture in the riser that is sized to receive a locking means. In the preferred embodiment, the engaging bracket has an aperture in the elongated riser which is sized to receive a locking means. In the preferred embodiment, two coplanar parallel flanges of the receiving bracket off-set two coplanar parallel flanges of the engaging bracket, upon assembly. In this way, various furniture components can be secured together. Additionally, this invention provides a system for a ready to assemble furniture piece made of a plurality of bracketed furniture components having at least one bracket being either an engaging bracket or a receiving bracket, whereby the bracketed furniture components are interconnected through a receiving bracket on one furniture component with accommodating engaging bracket on second furniture component. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a receiving bracket. FIG. 2 is a schematic view of an engaging bracket. FIG. 3 is a schematic view of a bracket assembly. FIG. 4A is a schematic top view of a receiving bracket. FIG. 4B is a schematic side view of a bracket assembly. FIG. 4C is a schematic view of a receiving bracket and an engaging bracket. FIG. 5A is a schematic top view of a receiving bracket and a compressible material. FIG. 5B is a schematic side view of a receiving bracket and a compressible material. FIG. 5C is a schematic view of a receiving bracket and a compressible material. FIG. 6A shows a schematic view of the assembly process involving two arm components and a base component. FIG. 6B shows the result achieved by the assembly of two arm components and a base component. FIG. 7A shows a schematic view of the assembly process involving the seat component and the result in FIG. 6B . FIG. 7B shows the result achieved by the assembly of the seat component, the base component and two arm components. FIG. 8 shows a schematic view of the assembly process involving the back component and the result in FIG. 7B . FIG. 9 shows the result achieved by the assembly of the back component, the seat component, the base component and two arm components. FIG. 10A shows a schematic view of a connected table support connector. FIG. 10B shows a schematic view of a disconnected table support connector. FIG. 11A shows a schematic view of a connected headboard and bedrail. FIG. 11B shows a top schematic view of a headboard and bedrail. FIG. 11C shows a front schematic view of a headboard and bedrail. FIG. 11D shows a right schematic view of a headboard and bedrail. FIG. 12A shows a schematic side view of a receiving bracket and pole. FIG. 12B shows a schematic side view of a sign connected to a pole via a bracket assembly. FIG. 12C shows a schematic view of a sign with engaging bracket and pole with receiving brackets. FIG. 13A is a schematic view of a portion of a casket. FIG. 13B is a schematic view of a portion of a casket. FIG. 13C is a schematic view of a portion of a casket. FIG. 13D is a schematic view of a portion of a casket. DETAILED DESCRIPTION OF THE INVENTION Referring now to FIGS. 1-3 , the bracket assembly 5 is made of a receiving bracket 2 and an engaging bracket 4 . Now referring to FIG. 1 , a receiving bracket 2 is made of a riser 34 . The riser 34 has an inner surface 44 and an outer surface 45 . The riser 34 may be straight, orthogonal, horizontal, sloped or curved. The riser 34 forms hollow internal section 20 . The receiving bracket 2 also includes a plurality of flanges 1 and 3 . In the preferred embodiment, two coplanar parallel flanges 1 and 3 perpendicularly extend from the riser 34 . In the preferred embodiment, two spaced apart vertical members 34 A extend from a receiving top member 35 to form the riser 34 . In this embodiment, the vertical riser 34 A is straight and orthogonal. Receiving brackets 2 are preferably two and a half inches in width and two inches in length, but may be any size as desired by one skilled in the art. Receiving brackets 2 are preferably made of steel or iron although other materials, such as plastic or a synthetic modification thereof, may be used as desired by one skilled in the art. The engaging bracket 2 can be made integrally with a component. In a preferred embodiment, the receiving bracket 2 is made of at least one planar flange 1 having an aperture 6 to receive an attachment means, such as a bolt, but other attachment means, such as spot welding or clamping, may be used as desired by one skilled in the art. At least one aperture 6 is preferably positioned in the center of each of the substantially parallel flanges 1 and 3 allowing for the receiving bracket 2 to be attached to a component (not shown in FIG. 1 ). A lock-down aperture 22 is positioned on the receiving bracket 2 to allow a locking means, such as a bolt, to contact the engaging bracket 4 to form a secure bracket assembly 5 , but any other locking means may be used as desired by one skilled in the art. In this way, one bracketed component is interconnected with a second bracketed component. Referring to FIG. 2 , an engaging bracket 4 is made of an elongated riser 36 having an inner surface 46 and an outer surface 47 . The elongated riser 36 may be straight, orthogonal, horizontal, sloped or curved. A plurality of flanges 23 and 24 perpendicularly extend from the elongated riser 36 . The plurality of flanges 23 and 24 form a line of intersection 48 with the elongated riser 36 . The elongated riser 36 is configured to extend beyond the plurality of flanges 23 and 24 to form a cantilevered projection 39 . The cantilevered projection 39 is made of two portions. A first portion 40 and a second portion 41 . In the first portion 40 , the line of intersection 48 extends past the plurality of flanges 23 and 24 to form an outer surface sized to contact the inner surface 44 of the receiving bracket 2 . Additionally, the cantilevered projection 39 has a second portion 41 which tapers and narrows where the line of intersection 48 has been cut away allowing for easy assembly of the engaging bracket 4 and receiving bracket 2 . In the preferred embodiment, two coplanar parallel flanges 23 and 24 extend from two spaced apart vertical members 36 A. In the preferred embodiment, the two spaced apart vertical members 36 A are straight and orthogonal. The spaced apart vertical members 36 A extend from the engaging top member 38 . The term riser can refer generically to a bracket having an external surface and a hollow internal section. More specifically, the terms two spaced apart vertical members refers to the preferred embodiment where the riser 36 is formed from two spaced apart members 36 A and a top member 38 . Engaging top member 38 projects beyond at least one flange 23 to form a cantilevered projection 39 . The cantilevered projection 39 has a tapered guide portion 41 to allow ease of initial assembly between engaging bracket 4 and receiving bracket 2 . The cantilevered projection 39 is sized to fit, with minimal clearance in receiving bracket internal section 20 . In the preferred embodiment, the engaging bracket 4 is made of at least one planar flange 23 having an aperture 11 to receive attachment means, such as a bolt. Any other attachment means, such as spot welding or clamping, may be used as desired by one skilled in the art. In the preferred embodiment, two coplanar parallel flanges 1 and 3 of the receiving bracket 2 off-set two coplanar parallel flanges 23 and 24 of the engaging bracket 4 upon assembly. Engaging brackets 4 are preferably two and a half inches in width and four inches in length but can be any size as desired by one skilled in the art. Engaging brackets 4 are made of steel or iron although other materials, such as plastic or a synthetic modification thereof, may be used as desired by one skilled in the art. The described shape of the receiving bracket 2 and engaging bracket 4 are constant but the overall size may change. The receiving bracket 4 can be integrally made with the component. Now referring to FIG. 3 , a bracket assembly 5 is shown. The bracket assembly 5 is formed of a receiving bracket 2 and an engaging bracket 4 which are placed in contact. The stability of the bracket assembly 5 is based upon contact between the outer surface 47 of elongated riser 36 of the engaging bracket 4 and the inner surface 44 of riser 34 of the receiving bracket 2 . Additionally, the stability of the bracket assembly 5 is based on contact between the first portion 40 of the cantilevered projection 39 of the engaging bracket 4 with the inner surface 44 of the riser 34 of the receiving bracket 2 . Additionally, the stability of the bracket assembly 5 can be based on contact between outer surface 45 of riser 34 of the receiving bracket 2 being in contact with the surface onto which the receiving bracket 2 is mounted. Now referring to FIGS. 4A-C , alternative engaging and receiving brackets are shown. The inner surface 44 and riser 34 of the receiving bracket 2 are sized to contact the outer surface 45 of the engaging bracket 4 . In particular, the stability of the bracket assembly 5 is increased by the contact of the inner surface 44 of the receiving bracket 2 with the first portion 40 of the cantilevered projection 39 of the engaging bracket 4 . Additionally, the strength of the bracket assembly 5 can be increased by providing an interference fit between the receiving bracket 2 and engaging bracket 4 . An interference fit occurs when the receiving bracket 2 is mounted on a material, such as wood. Wood will compress on the open side 20 of receiving bracket 2 to create a tight fit. Additionally, an interference fit occurs when the receiving bracket 2 is mounted to a material dissimilar to the engaging bracket 4 material. Similarly, a compressible layer of material, such as rubber can be placed between the receiving bracket and the material to which the receiving bracket is mounted. Now referring to FIG. 5A-C , the interference fit can be enhanced by relying on the compressibility of the material onto which the receiving bracket 2 is mounted, such as wood. Wood will compress on the open side 20 of the receiving bracket 2 to create a tight fit. Similarly, a compressible layer of material 50 can be placed between the receiving bracket and the material onto which the receiving bracket 2 is mounted if the material to which the bracket is mounted, i.e., steel, has inadequate compressibility for this purpose. The bracket assembly 5 is further strengthened by lock down aperture 22 wherein a locking means such as a bolt is used to secure the receiving bracket 2 to engaging bracket 4 . Any other locking means may be used as desired by one skilled in the art. The lock down aperture 22 is positioned to allow a locking means, such as a bolt to contact the cantilevered portion 39 of engaging bracket 4 . The receiving bracket 2 and engaging bracket 4 are attached to panels which are formed into components. The components assemble to form furniture, signage and caskets. The terms “receiving” and “engaging” when used to describe a bracket refer to the shape of a bracket and not to the motion of the assembly process. A furniture component is at least one panel having at least one engaging or receiving bracket attached thereto. In a preferred embodiment, a furniture component is made of a plurality of panels. A furniture component is fixedly attached to another furniture component by forming bracket assemblies 5 between the furniture components. The furniture components with at least one engaging or receiving bracket are referred to as a bracketed furniture components. A furniture component is the basic building block of this system. Furniture will be shipped as bracketed furniture components. Now referring to FIGS. 6A-9 , the system and method to assemble a chair is shown. In this illustrative embodiment, the ready to assemble furniture piece 25 is made of five basic furniture components 10 , 12 , 14 and 16 including two opposing arm components 10 , a base component 12 , a seat component 14 , and a back component 16 . Depending on the styling of the furniture, more or less components can be used. These components are interconnected through receiving brackets 2 and engaging brackets 4 attached to the panels or made integrally with the panel. The bracketed furniture components 10 , 12 , 14 and 16 are preferably made of a plurality of furniture panels, such as 7 , 8 , 9 , 13 and 14 . A furniture component may be made of single panel as desired by one skilled in the art. A furniture panel is any part of the frame in which a bracket is attached, but not limited to wood; a panel can include other materials, such as steel and aluminum for example. Receiving brackets 2 and engaging brackets 4 are attached to the furniture components 10 , 12 , 14 and 16 in designated positions depending on the type and design of the ready to assemble furniture piece 25 desired. The brackets 2 and 4 are not location dependent. One skilled in the art may place the engaging brackets 4 and receiving brackets 2 at any location on the furniture components that allows for the furniture components to be interconnected by forming bracket assemblies 5 . The brackets can be attached anywhere on the panels as long as they position interlock with a corresponding bracket on another component. The number, shape and size of the arm components 10 , the base component 12 , the seat component 14 and back component will vary depending on the type and design of the ready-to-assemble furniture piece 25 desired. Also, the number of total bracket assemblies 5 used to interconnect furniture component will vary as desired by one skilled in the art. The number of receiving brackets 2 and engaging brackets 4 attached on the furniture panels 7 , 8 , 9 , 13 and 15 will vary depending type and design of the ready-to-assemble furniture piece 25 desired. A ready to assemble furniture piece 25 could be made of different bracketed components that those disclosed in this illustrative embodiment. For example, the bracketed component could be a table top, table leg, cabinet back, cabinet front, cabinet drawers, etc. Referring to FIG. 6A , a portion of chair or small couch is shown. More specifically, two furniture arm components 10 are shown. The arm components 10 are made of differing materials and vary in size depending on the type and design of the ready to assemble furniture piece 25 desired. The arm component 10 is made of three major elements: a back side arm panel 7 , a front side arm panel 17 ; and a side arm panel 8 . A back side arm panel 7 includes a means to support a receiving bracket, such as a substantially perpendicular member 26 . The receiving bracket 2 is attached by nails through aperture 6 to the perpendicular member 26 , but other attachment means may be used as desired by one skilled in the art. The receiving bracket 2 of the back side arm panel 7 is preferably attached between the middle and top of the back side arm panel 7 . The front side arm panel 17 is substantially parallel to the back side arm panel 7 and is connected to the side arm panel by a plurality of support members 27 . The side arm panel 8 is substantially perpendicular to the back side arm panel 7 and front side arm panel 17 , and is connected to both. The side arm panel has a plurality of receiving brackets 2 and a plurality of engaging brackets 4 attached thereto. The brackets are positioned to connect with corresponding brackets on another furniture component to form a bracket assembly. A bracket assembly can be strengthened by applying an adhesive, bolt or screw to lock down aperture 22 . The base component 12 is made of a first side base panel 9 and a second side base panel 30 . The base component 12 is also made of a front base panel 28 and a rear base panel 29 . The first side base panel 9 and second side base panel 30 has an interior and exterior surface to which engaging brackets 4 and receiving brackets 2 are attached. FIG. 6B depicts the result achieved by the assembly of two opposing arm components 10 and a base component 12 . More specifically, two arm components 10 are contactingly moved adjacent to base component 12 . A plurality of engaging brackets 4 attached to the horizontal side arm panel 8 are inserted into receiving brackets 2 on the exterior surface of the first side base panel 9 and second side base panels 30 of the base component 12 . Referring to FIG. 7A , the seat component 14 is made of a first and second side seat panels 13 . A plurality of engaging brackets 4 are vertically mounted on the exterior of each side seat panel 13 . In the preferred embodiment, two sets of engaging brackets 4 are attached near the front and rear sections of the side seat panels 13 allowing for the seat component 14 to lock with the arm components 10 upon assembly. The seat component 14 also includes a front seat panel 31 and rear seat panel 32 . The seat panels 13 , 31 and 32 are interconnected at right angles to form a frame. The receiving brackets 4 on the horizontal side arm panel 8 , and arm component 10 are positioned to receive engaging bracket 4 on side seat panel 13 of seat component 14 . FIG. 7B depicts the result achieved by the assembly of the seat component 14 , the base component 12 and the two opposing arm components 10 . Referring to FIG. 8 , the back component 16 is made of two side back panels 15 . An engaging bracket 4 is vertically mounted on the exterior of each side back panels 15 near the middle section of each side back panel 15 allowing for the back component 16 to interconnect with the arm components 10 upon assembly. An engaging bracket 4 is vertically mounted on the interior of the side back panels 15 in the lower section of each side back panel 15 allowing for the back component 16 to lock with the base component 12 upon assembly. The back component 16 is further made of a back panel 33 that is substantially perpendicular and attached to the two side back panels 15 . FIG. 9 depicts the ready to assembled furniture piece 25 . The ready to assemble furniture piece 25 , a chair, is preferably made of furniture components 10 , 12 , 14 and 16 including the back component 16 , the seat component 14 , the base component 12 and two arm components 10 . Each furniture component 10 , 12 , 14 and 16 is made of furniture panels 7 , 8 , 9 , 13 and 15 which are preferably wooden but may be made of other materials, as desired by one skilled in the art. The furniture components can be upholstered, allowing the brackets to be attached to the exterior of the upholstery or can be upholstered when assembled. The furniture components 10 , 12 , 14 and 16 are assembled by interconnecting the receiving brackets 2 and engaging brackets 4 which together form bracket assemblies 5 . The number of bracketed assemblies used will vary depending on the styling of the furniture. At least one receiving bracket 2 or engaging bracket 4 is attached to furniture panels 7 , 8 , 9 , 13 and 15 of each furniture component 10 , 12 , 14 and 16 . In relation to the presently illustrative configuration, it should be understood that the ready to assemble furniture piece 25 is readily adaptable to all types of furniture pieces including but not limited to sofas, sleepers, loveseats, chairs, and motion furniture. Moreover, the ready to assemble furniture piece is readily adaptable to most types and designs of furniture including but not limited to leather, fabric, show wood, loose cushion, single cushion, single back and split back. This system is not exclusively intended for upholstered furniture use, but can be used in other areas of the furniture industry, such as cabinets and tables. More specifically, as shown in FIGS. 10A and 10B a table support connection is shown. The table support 81 has a plurality of receiving brackets 2 attached around the table support 81 . A table leg 83 has an engaging bracket 4 attached. The receiving bracket 2 and engaging bracket 4 are positioned to allow the table leg 83 to connect with table support 81 . In the preferred embodiment, there are four receiving brackets 2 attached equidistantly around the table support 81 , but more or less brackets may be used as desired by one skilled in the art. The four receiving brackets are connected to four engaging brackets 4 to affix the table legs 83 to a table support 81 . Additionally, in FIGS. 11A-D , bedpost and bedrail connections are shown. In FIG. 11A , a bedrail 93 is attached by a bracket assembly 5 to a bedpost 91 . FIGS. 11B-11D show cutaway sections of the connection viewed from above ( FIG. 11B ), the side ( FIG. 11C ) and along the axis of the bedrail ( FIG. 11D ). In FIGS. 12A , 12 B and 12 C, signage connection is shown. More specifically, a pole 101 has a receiving bracket 2 attached thereto. An engaging bracket 4 is attached to the back surface of a sign 103 . The sign is attached to the pole 101 through bracket assembly 5 . Referring to FIGS. 13A-D , the receiving brackets 2 and engaging brackets 4 can be used to assemble a casket. In FIG. 13D , a bracket assembly 5 combines the components to form a casket. The bracket assembly and system is advantageous because it allows the assembly of all types of furniture by a single individual. Moreover, the present invention is advantageous because it allows assembly at any place with no tools required for assembly and in approximately one to two minutes. Unlike present technology which is complicated and labor and part intensive, the self-assembly bracket and system has no loose parts to assemble. The required hardware for the present invention is only the receiving brackets 2 and engaging brackets 4 placed at integral parts on the ready to assembly furniture piece 25 . Although the forgoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be obvious that certain changes and modifications can be made which are within the full scope of the invention.

The invention discloses unique brackets, which form a bracket assembly that may be placed at any location of various components to form an assembly piece, such as furniture. An assembled furniture piece made of furniture panels interconnected with attached engaging and receiving brackets is provided. The engaging and receiving brackets are positioned on components to facilitate the connection of the components. A method to assemble furniture having preformed arm, base, seat and back components is provided. This method of assembly saves on shipment costs, and facilitates the repair of damaged furniture.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of provisional U.S. Patent application No. 60/320,294 filed on Jun. 20, 2003 the disclosure of which is hereby incorporated by reference. BACKGROUND OF INVENTION [0002] Alpha Lipoic acid is taken up by cells and is reduced to a pharmacologically active dithiol form in several physiological reactions. However this active dithiol form is effluxed out of the cell rapidly decreasing the effectiveness of α-Lipoic acid. [0003] Various mechanisms have been devised to enhance the retention of the active dithiol form within the cell. One such approach is a structurally modified version of α-Lipoic acid called LA-plus, chemically N-[2-(dimethylamino)ethyl]-1,2-dithiolane-3-pentanamide monohydrochloride, which is represented by the formula [0004] The protonated form of the corresponding derived dithiol molecule under physiological conditions is more efficiently retained within the cell and performs much better in physiological reactions than the parent α-Lipoic acid. This has been the subject of research papers (Sen, Chandan K; Tirosh, Oren; Roy, Sashwati; Kobayashi, Michael S; Packer, Lester; Biochemical and Biophysical research Communications, (1998), 247, 223-228). [0005] These workers demonstrated that the uptake of LA-Plus was much higher in certain cells and also the intracellular amount of the corresponding dithiol form within the cell was much greater compared to α-Lipoic acid. Hence they came to the conclusion that LA-Plus is an improved form of Lipoic acid with enhanced therapeutic potential. [0006] The (R)-form of LA-Plus described in the above work was synthesized by the reaction of Lipoic acid to which three equivalents of N,N-dimethylethylenediamine were added followed by N-hydroxysuccinimide. Dicylohexylcarbodiimide was subsequently added and the reaction time was one day. The product was extracted into the aqueous phase using hydrochloric acid and extracted into chloroform after basification of the aqueous phase using sodium hydroxide. This organic phase was dried, filtered and evaporated to dryness. The residue was redissolved in dichloromethane and hydrogen chloride gas was passed through the organic solvent up to saturation. The dichloromethane solvent was evaporated and the HCl salt of N,N-dimethyl-N″-2-amidoethyl-lipoate was precipitated using anhydrous ether. [0007] It should be noted that the preparation LA-Plus hydrochloride involves extraction and re-extraction of the product in and out of aqueous/organic media. Also it involves the passage of hydrogen chloride gas, which is corrosive and difficult to use. Several solvents such as chloroform, methylene chloride, and dry diethyl ether are employed in the process. [0008] Hence the synthesis of LA-plus as described in prior art is involved and not easily adaptable to large-scale operations (Sen, Chandan K; Tirosh, Oren; Roy, Sashwati; Kobayashi, Michael S; Packer, Lester; Biochemical and Biophysical research Communications, (1998), 247, 223-228). [0009] More particularly, the product, both the racemeic (±)-LA-Plus hydrochloride and chiral (R)-LA-Plus hydrochloride forms are not good solids. They were also found to be hygroscopic and not easily handled during transfer and other operations. [0010] In spite of the difficulty of handling LA Plus hydrochloride, applications involving this hygroscopic salts have been claimed (U.S. Pat. No. 5,965,618, U.S. Pat. No. 6,090,842, WO 0180851). Hence there is a need for a new salt form of LA-plus base which would be a good solid, non-hygroscopic and easily handled for various operations. [0011] The preparation and use of compositions containing Lipoic acid or its derivatives, including LA-plus, for nutraceutical and cosmetic applications is widely described in prior art for example in U.S. Pat. Nos. 6,743,433 and 6,365,623 that describe compositions for the treatment of acne; U.S. Pat. Nos. 6,387,945, 6,235,772 and 6,090,842 that describe Lipoic acid analogs. The preparations of the current invention were found to be similarly biologically active. SUMMARY OF INVENTION [0012] The present invention describes a convenient method of manufacture of of LA Plus base (N-[2-(dimethylamino)ethyl]-1,2-dithiolane-3-pentanamide ((±)-N-1-[2-(dimethylamino)ethyl]-5-(1,2-dithiolan-3-yl) pentanamide) from Lipoic acid. In addition stable, crystalline salts of LA Plus are described which are easily stable, non-hygroscopic and handled. Uses of such salts are described in various cosmetic applications such as skin care and hair care applications. DETAILED DESCRIPTION [0013] Our present invention addresses these issues. In this invention, (±)-Lipoic acid is treated with a slight excess of 1,1′-Carbonyl diimidazole and the intermediate acyl imidazole is reacted with N,N-dimethylethylenediamine to form N-[2-(dimethylamino)ethyl]-1,2-dithiolane-3-pentanamide (LA-Plus base) in methylene chloride solution. Removal of methylene chloride and precipitation of the LA-Plus base as its maleate salt, LA-Plus maleate, forms the rest of the process. [0014] The structures of the materials referred in this patent are shown as follows [0015] Even though the examples are illustrative of the invention, they do not limit the scope of the invention. Lipoic acid is reacted with carbonyl diimidazole in a solvent such as methylene chloride. It is then treated with N,N-dimethylethylene diamine in the same solvent. The solvent was removed, replaced by acetone and the acid component was added to precipitate the desired material. For example, a similar process can be conceived for N,N-Dimethyl propylene diamine replacing N,N-dimethyl ethylenediamine to give another analog of LA-Plus. Similarly, another reactive acyl imidazole could be formed with 1,1″-Carbonylbis(2-methylimidazole), CAS registry no. 13551-83-2, with similar results. Such variations also fall within the scope of this invention. [0016] We also found that stable, non-hygroscopic salts of LA Plus could be formed with fumaric acid in place of maleic acid as another example illustrating this invention. [0017] The method is applicable for (±)LAPlus maleate as well as its chiral forms. For example, instead of (±)-Lipoic acid, if one uses R-(+)-Lipoic acid as the starting material, one again obtains the corresponding R-(+)-LA Plus maleate or fumarate depending on the acid that is employed for salt formation. [0018] The solubility data on the LA Plus salts described in this patent are given in Table 1 TABLE 1 Solubility Data WATER ETHANOL PROPYLENE SAMPLE (D. D.) (95%) GLYCOL Alpha lipoic acid 0.03%   57% 20% LA plus (Maleate) 60% 7.35%   13% LA plus (Fumarate) 100%  51% 23% R (+)-LA plus 60% 6.84%   10% (Maleate) Results in gm/dl; tests were done at 35 to 40° C. temperature. [0019] It is clear from the data that the solubilities of the maleate and fumarate salts in water are much higher than that of α-Lipoic acid. Hence these stable, nonhygroscopic salts are easy to formulate in water based formulations. TABLE 2 Antioxidant assay by DPPH radical scavenging activity Exposure to sun light for Absence of sun light 5 minutes Sample/Batch No. Conc. % Scavenging Conc. % Scavenging Alpha lipoic acid 6 mg 50% 45 μg 50% LA plus (Maleate) 6.6 mg 54% 55 μg 53% R(+)-LA plus 6.6 mg 49% 55 μg 47% (Maleate) LA plus (Fumarate) 6.2 mg 57% 55 μg 50% Ascorbic acid 6 μg 71% 6 μg 59% [0020] LA Plus maleate and fumarate salts and α-Lipoic acid showed a marked difference in scavenging the DPPH radical when exposed to sunlight which was not shown by Ascorbic acid. Even when the concentration was 120 times lesser, the activity was comparable with exposure to sunlight (5 minutes). This data attest to the unique antioxidant ability of LA Plus salts in particular. [0021] The inhibitory properties of LA Plus salts of the enzyme tyrosinase is shown in Table 3. Tyrosinase inhibition is one of the established in vitro methods of evaluating the skin fairness property. TABLE 3 Activity on Tyrosinase Tyrosinase Sample Conc. % Inhibition Alpha lipoic acid (KU030121) 100 μg 51% LA plus (Maleate) 120 μg 58% R(+)-LA plus (Maleate) 120 μg 58.6%   LA plus (Fumarate) 120 μg 53% [0022] LA Plus maleate, LA Plus fumarate and R(+) LA Plus maleate (the three water soluble LA Plus salts) and α-Lipoic acid have thus the property as skin fairness/de-pigmentation product. [0023] The inhibitory studies of LA Plus maleate, LA Plus fumarate and R(+) LA Plus maleate (the three water soluble LA Plus salts) and α-Lipoic acid on Collagenase and Elastase disclosed that these Lipoic acid derived salts are good inhibitors of these enzymes. The IC 50 values for Collagenase were found to be the same, namely, 1.6 mg/ml for LA Plus maleate, LA Plus fumarate and R(+) LA Plus maleate (the three water soluble LA Plus salts) and α-Lipoic acid. Similarly the IC 50 values for Elastase were found to be the same, namely, 1.4 mg/ml for LA Plus maleate, LA Plus fumarate and R(+) LA Plus maleate (the three water soluble LA Plus salts) and α-Lipoic acid. The formulations containing these salts are thus useful in antiaging effects and in preventing wrinkle formations in the skin. Our research further disclosed that LA Plus maleate, LA Plus fumarate and R(+) LA Plus maleate (the three water soluble LA Plus salts) and α-Lipoic acid display very good inhibition properties against Propionibacterium acnes . The important findings from these studies are as follows. [0024] Two of derivatives of α-Lipoic acid viz., R(+) LA+Maleate and α-LA+Maleate are giving good inhibition of P. acnes and are showing inhibition at the minimum concentration of 1.0%. This is well comparable with that of the control [Clindamycin]. [0025] The compound α-Lipoic acid and one of its derivatives, α-LA+Fumarate are giving inhibition of P. acnes at the concentrations of 5 and 2% respectively. [0026] The inhibitory activity of these compounds are in the following order: R (+) LA Plus Maelate>LA Plus Maleate>LA Plus Fumrate>α-Lipoic acid [0027] Our results show that the LA Plus salts show a better activity than a standard drug like Clindamycin. [0028] The results are presented in the following Table 4 TABLE 4 Zone of inhibition (in mm) α-Lipoic R(+) LA Conc. of the acid Plus LA Plus LA Plus sample (%) (α- LA) Maleate Maleate Fumarate Clindamycin 10 8 15 11 10 20 5 7 12 9 8 15 2 0 10 8 7 9 1 0 8 7 0 7 0.5 0 0 0 0 0 [0029] Conclusion: From these studies it is evident that two derivatives of α-Lipoic acid, viz., R (+) LA Plus Maleate and LA Plus Maleate can work as good antiacne agents. ILLUSTRATIVE EXAMPLES Example 1 (±)-Maleate salt of N-[2-(dimethylamino)ethyl]-1,2-dithiolane-3-pentanamide(±-Maleate salt of N-1-[2-(dimethylamino)ethyl]-5-(1,2-dithiolan-3-yl)pentanamide, (±)-LA Plus maleate salt) [0030] 1,1″-Carbonyl diimidazole (43 g in 150 ml of methylene chloride under nitrogen atmosphere) was cooled to 5-10° C. To the cold solution (±)-Lipoic acid (52 g in 250 ml of methylene chloride) was added slowly. Stirring was continued at room temperature after completion of addition. A clear solution was obtained. This solution was cooled to 5-10° C. and N,N-Dimethylethylenediamine (27 g) was added slowly. [0031] The resultant solution was stirred for 3 hours at room temperature The methylene chloride layer was dried over sodium sulfate and the solvent was removed. The residue was dissolved in dry acetone (250 ml) and to this well-stirred solution, maleic acid (28 g in 250 ml acetone) was added slowly. The precipitated product was filtered and dried. [0032] Yield: 89 g; Mp: 125-127° C.; Elemental analysis (Calculated values for C 16 H 28 N 2 O 5 S 2 in parentheses) Carbon, 48.94% (48.96%); Hydrogen, 7.22% (7.19%); Nitrogen, 7.15% (7.14%). Example 2 R-(+)-Maleate salt of N-[2-(dimethylamino)ethyl]-1,2-dithiolane-3-pentanamide(R-(+)-Maleate salt of N-1-[2-(dimethylamino)ethyl]-5-(1,2-dithiolan-3-yl)pentanamide, (+)-LA Plus maleate salt) [0033] Same procedure as in example 1 excepting that R-(+)-lipoic acid was used in place of (±)-Lipoic acid. [0034] Mp: 125-127° C.; Elemental analysis (Calculated values for C 16 H 28 N 2 O 5 S 2 in parentheses): Carbon, 49.12% (48.96%); Hydrogen, 7.06% (7.19%); Nitrogen, 6.99% (7.14%)Specific rotation: 53.80 (c=10.52 mg/ml of water) Example 3 (±)-Fumarate salt of N-[2-(dimethylamino)ethyl]-1,2-dithiolane-3-pentanamide(±)-Fumarate salt of N-1-[2-(dimethylamino)ethyl]-5-(1,2-dithiolan-3-yl)pentanamide, (±)-LA Plus fumarate salt) [0035] Same procedure as in Example 1 excepting that fumaric acid is used in place of maleic acid. [0036] Mp: 76-78° C.; Elemental analysis: (Calculated for values C 16 H 28 N 2 O 5 S 2 in parentheses) Carbon, 48.87% (48.96%); Hydrogen, 6.99% (7.19%); Nitrogen, 7.22% (7.14%).

A process for the manufacture of new crystalline salts of N-[2-(dimethylamino)ethyl]-1,2-dithiolane-3-pentanamide (racemic and chiral forms) is described. Such salts are stable, crystalline and have very good solubility in water. The salts exhibit antioxidant properties. They inhibit collagenase and elastase enzymes. They have excellent anti acne activity in addition tyrosinase inhibition. They are, by themselves and in combination with other known agents, important cosmetic ingredients.

BACKGROUND [0001] The present disclosure relates to synchronized wireless data concentrators. In particular, it relates to synchronized wireless data concentrators for airborne wireless sensor networks. SUMMARY [0002] The present disclosure relates to an apparatus, system, and method for synchronized wireless data concentrators for airborne wireless sensor networks. In one or more embodiments, the disclosed system for airborne wireless sensor networks includes at least one wireless data concentrator (WDC) operable as a router. The system further includes at least one processor that runs hosted applications related to at least one WDC operable as a router. Also, the system includes at least one network switch that is connected to at least one WDC operable as a router and connected to at least one processor. In addition, the system includes at least one node that is wirelessly in communication with at least one WDC operable as a router. [0003] In one or more embodiments, at least one WDC operable as a router includes at least one standard router, and at least one node that operates as a standard node. In at least one embodiment, at least one standard router and/or at least one node operable as a standard node employ a Zigbee communications protocol. In some embodiments, at least one standard router transmits and receives signals to at least one node operable as a standard node. In one or more embodiments, at least one node operable as a standard node is powered by battery power, a wired power line, and/or strong harvested energy. In some embodiments, the strong harvested energy is harvested from thermoelectric power, vibration, and/or inductive coupling to a high voltage (e.g., a high voltage produced by generators). [0004] In at least one embodiment, at least one WDC operable as a router includes at least one green router, and at least one node that operates as a green node. In one or more embodiments, at least one green router and/or at least one node operable as a green node employ the Zigbee communications protocol. In some embodiments, at least one green router receives signals from at least one node operable as a green node. In one or more embodiments, at least one node operable as a green node transmits its state three times sequentially in a row to at least one green router. In at least one embodiment, at least one node operable as a green node is powered by harvested energy. In some embodiments, the harvested energy is harvested from solar power and/or manual actuation power (e.g., the manual action of flipping a switch). [0005] In one or more embodiments, at least one processor is an application server. In at least one embodiment, at least one network switch is an Ethernet switch (e.g., an IEEE-1588 Ethernet switch). In some embodiments, the disclosed system further includes at least one WDC operable as a coordinator. In at least one embodiment, at least one WDC operable as a coordinator employs the Zigbee communications protocol. In one or more embodiments, at least one WDC operable as a coordinator is in wireless communication with at least one WDC operable as a router. In at least one embodiment, at least one WDC operable as a coordinator coordinates communications with at least one WDC operable as a router. [0006] In at least one embodiment, the disclosed method for airborne wireless sensor networks involves transmitting state information from at least one node. The method further involves receiving, by at least one wireless data concentrator (WDC) operable as a router, the state information from the node(s). In addition, the method involves transmitting the state information from at least one WDC operable as a router. Additionally, the method involves receiving, by at least one WDC operable as a coordinator, the state information from the WDC(s) operable as a router. Further, the method involves sending the state information, by at least one WDC operable as a coordinator, to at least one processor for processing. In one or more embodiments, the method further involves coordinating, by at least one WDC operable as a coordinator, communications with at least one WDC operable as a router. In at least one embodiment, the state information is sent from at least one WDC operable as a coordinator to at least one processor via a network switch. [0007] In one or more embodiments, the disclosed wireless data concentrator (WDC) for airborne wireless sensor networks includes at least one router, where at least one node is in communication with the router(s). In addition, the disclosed WDC includes at least one microprocessor, where the microprocessor(s) processes signals received by the router(s) from the node(s). The disclosed WDC further includes at least one clock crystal, where the clock crystal(s) is used for synchronizing communications for at least one router. [0008] The features, functions, and advantages can be achieved independently in various embodiments of the present inventions or may be combined in yet other embodiments. DRAWINGS [0009] These and other features, aspects, and advantages of the present disclosure will become better understood with regard to the following description, appended claims, and accompanying drawings where: [0010] FIG. 1 shows a high level architectural view of the disclosed system for synchronized wireless data concentrators (WDCs) for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. [0011] FIG. 2 is a detailed diagram showing the process for how keys are securely managed within the system of FIG. 1 , in accordance with at least one embodiment of the present disclosure. [0012] FIG. 3 is a diagram of a two-channel wireless data concentrator (WDC) that is employed by the system of FIG. 1 , in accordance with at least one embodiment of the present disclosure. [0013] FIG. 4 is a diagram of a four-channel WDC, in accordance with at least one embodiment of the present disclosure. [0014] FIG. 5 is a diagram of an eight-channel WDC, in accordance with at least one embodiment of the present disclosure. [0015] FIG. 6 is a diagram of a sixteen-channel WDC, in accordance with at least one embodiment of the present disclosure. [0016] FIG. 7 is a detailed diagram depicting the extended precision time protocol (PTP) operation on a two-channel WDC, in accordance with at least one embodiment of the present disclosure. [0017] FIG. 8 is a table that shows the typical drift rate for the two crystal (Xtal) devices employed by the disclosed system for synchronized WDCs for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. [0018] FIG. 9 is a diagram depicting a modification of a standard Zigbee/IEEE-802.15.4 software stack which is employed by the disclosed system for synchronized WDCs for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. DESCRIPTION [0019] The methods and apparatus disclosed herein provide an operative system for wireless data concentrators. Specifically, this system relates to synchronized wireless data concentrators (WDCs) for airborne wireless sensor networks. In particular, the present disclosure teaches a wireless data concentrator (WDC) architecture that significantly advances the flexibility, adaptability, utility, determinism, and security in a large network of wireless sensor network (WSN) devices, which are applied to a commercial aerospace environment. The application space for aircraft WSNs is diverse and poses challenges in reliability, bandwidth management, latency, and security domains. The present disclosure sets forth a broad architecture structure, and a WDC design, which can support the objectives of improved flexibility, adaptability, utility, determinism, and security more than the currently offered solutions. [0020] Key aspects that are provided by the disclosed system are: 1.) precision time synchronization of nodes in a wireless sensor network to enable a system design pattern of time-based real-time programming; 2.) bandwidth, throughput, and latency management in a large IEEE-802.15.4 wireless sensor network through the use of a wired Ethernet backbone topology; 3.) a distributed trust center, a wired secure key-transport, and key management system; and 4.) parallel WSN channel operation for optimized wireless bandwidth. [0021] Zigbee is a type of Low Power Wireless Personal Area Network (LP-WPAN) data communication protocol stack, which is used to standardize low data rate transmission between low power wireless devices. Zigbee does not describe the entire software communication stack, but is rather a set of networking framework layers built on top of the IEEE-802.15.4 standard. Systems and environments that typically deploy Zigbee are environments such as home automation, home entertainment, building automation and, most recently, smart energy. Aerospace non-essential systems represent a new area for LP-WPAN deployment so that smart wireless sensors can be distributed throughout the aircraft cabin, structures, and systems; and can provide monitoring, alerting, on-demand services, and non-essential control functions. [0022] However, when considering employing Zigbee for a large scale architecture adaptable to a wide range of aerospace applications, it is important to understand some of the shortcomings imposed by Zigbee. Although Zigbee is a robust stack, certain design decisions have been made by commercial microprocessor/radio hardware chip manufacturers and Zigbee software stack vendors. These decisions have been made in order to accommodate the size of object code that can fit into current program memory and runtime variables in data memory within various low cost Zigbee/802.15.4 radios in today's marketplace. Some of these shortcomings are: lack of medium access control (MAC) and network (NWK) layer support for time-slotted or time-based design patterns, the data security is limited to symmetric-key algorithms, lack of a secure key management system, and lack of robust support for energy harvesting sensor devices. [0023] The system of the present disclosure sets forth an architectural structure and a network topology that significantly improves over the limitations stated above to better address the additional environmental and application requirements of airborne systems. The main features of the disclosed system are: 1.) an introduction of a low cost, local host microprocessor within the wireless data concentrator, which is hardwire connected to both an Ethernet backbone and a plurality of wireless sensor network “router” devices; 2.) an inclusion of a system-wide hierarchical, precision time distribution means to bridge into the wireless sensor network area; 3.) a distributed security trust center mechanism for fast and secure management of network keys; and 4.) parallel Zigbee channel capability that can better handle throughput, latency, and energy harvesting performance demands on the system. [0024] FIG. 1 shows a high level architectural view of the disclosed system 100 for synchronized wireless data concentrators (WDCs) 110 , 120 for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. In this figure, the system 100 is shown to include five (5) WDCs. Four (4) of the WDCs 120 are operating as routers, and one WDC 110 is operating as a coordinator. The one WDC 110 operating as a coordinator 115 communicates wirelessly (as denoted by the dashed lines in the figure) with the four WDCs 120 , and coordinates the communications of the four WDCs 120 , which are all situated in a single aircraft zone. In general, one WDC 110 operating as a coordinator is employed per aircraft zone. An aircraft zone is, for example, a specific defined area within the cabin and/or cockpit of an aircraft. The WDC 110 operating as a coordinator is wired (as denoted by the solid line in the figure) to an IEEE-1588 Ethernet switch 160 , and employs the Zigbee communications protocol. [0025] The four WDCs 120 operating as routers are wired (as denoted by the solid lines in the figure) to the IEEE-1588 Ethernet switch 160 , which is connected to an application server 145 . The application server 145 , which includes at least one processor, is used to run host applications. In addition, a GPS receiver 155 is connected to an IEEE-1588 Grand Master 150 , which uses a GPS signal from the GPS receiver 155 for time synchronization. The Grand Master 150 is connected to the IEEE-1588 Ethernet switch 160 , and passes time synchronization data packets to the IEEE-1588 Ethernet switch 160 through that connection. [0026] Each of the four WDCs 120 operating as routers is shown to include one Zigbee green router 125 and one Zigbee standard router 130 . It should be noted that in other embodiments, the system 100 may employ WDCs 120 that include various different quantities of Zigbee green routers 125 and Zigbee standard routers 130 . Both the Zigbee green router 125 and the Zigbee standard router 130 employ the Zigbee communications protocol. The Zigbee standard router 130 transmits and receives signals to Zigbee standard endpoint nodes 140 , which contain monitoring sensors and are situated about the aircraft cabin within the specific aircraft zone of the WDCs 110 , 120 . The signals include information regarding the state of the Zigbee standard endpoint nodes 140 , time synchronization information, as well as acknowledgement (ACK) information (e.g., acknowledgement information sent in ACK data packets) regarding the receipt of the state information. The Zigbee standard endpoint nodes 140 are powered by various means including, but not limited to, battery power, a wired power line, and strong harvested energy. It should be noted that types of strong harvested energy include, but are not limited to, thermoelectric power, vibration, and inductive couple to a high voltage. [0027] The Zigbee green router 125 receives signals from Zigbee green endpoint nodes 135 , which contain monitoring sensors and are situated about the aircraft cabin within the specific aircraft zone of the WDCs 110 , 120 . It should be noted that the Zigbee green router 125 does not transmit signals, it only receives signals. The Zigbee standard endpoint nodes 135 periodically transmit their respective state three times sequentially in a row. Since the Zigbee green router 125 cannot transmit signals, the Zigbee green router 125 does not send acknowledgement signals regarding the receipt of state information to the Zigbee green endpoint nodes 135 . The Zigbee green endpoint nodes 135 are powered by harvested energy, which includes, but is not limited to, solar power and manual actuation power. [0028] The system 100 of FIG. 1 is applicable to numerous applications within the aircraft. Examples of these applications include, but are not limited to, passenger control of reading lights; window dimming and flight attendant call lights from energy harvesting control buttons in the seats; aircraft systems monitoring functions, such as temperature and air flow within the passenger cabin; and sensors within the aircraft structure, engines, landing gear, wings, tail sections, power systems, hydraulic systems, or any other system within the aircraft that can benefit from prognostic monitoring of aircraft health and system state. The sensors of the endpoints 135 , 140 are designed to sense various things according to their function for the particular application(s) of the system 100 . Types of things that the sensors are designed to sense include, but are not limited to, temperature, light, power, and air flow. In this figure, a software application server 145 contains certain “hosted functions.” These “hosted functions” are software programs designed to receive information from various sensing elements. The programs then store and process this information into useful operations for passengers, crew, and/or maintenance personnel, as dictated by the requirements of the “function.” The “hosted functions” communicate with various sensors via the Ethernet switch 160 , which is connected to a plurality of WDCs 110 , 120 strategically positioned throughout an aircraft. [0029] The disclosed system 100 uses the IEEE-1588 precision time protocol (PTP) as a baseline timing means that is extended to the various WDCs 110 , 120 through the IEEE-1588 compliant Ethernet switch 160 . In order to utilize IEEE-1588, a suitable PTP time generator, such as the Symmetricon “Timeprovider 5000”, is utilized to provide a grand master time base to the network. The IEEE-1588 grand master 150 typically gets its reference time from a GPS signal to provide better than a 100 nanosecond time synchronization to global Earth time. Precision time packets are distributed through the Ethernet switch 160 to each of the WDCs 110 , 120 , where the time synchronization is maintained at each WDC 110 , 120 within the typical performance limits of a typical IEEE-1588 Ethernet network (i.e. <microsecond). An important feature of this system 100 design is the bridging of the PTP protocol through the 802.15.4 Zigbee router devices 125 , 130 to Zigbee endpoints 135 , 140 served by each router 125 , 130 within a WDC 120 . In at least one embodiment, a single WDC 110 coordinator 115 starts the network in a traditional Zigbee protocol, but then can optionally distribute the coordinator function to selected WDCs 120 . This feature helps to improve the performance and management of large number of sensors within the purview of the WDC 110 selected for the distributed coordinator function, when the number of endpoints 135 , 140 exceeds a predetermined threshold. [0030] FIG. 2 is a detailed diagram showing the process for how keys are securely managed within the system 100 of FIG. 1 , in accordance with at least one embodiment of the present disclosure. A typical Zigbee environment will have a single trust center manager (TC M ) designated at the WDC 110 that is operating as a coordinator of the network. The Zigbee address of the trust center manager is usually aligned with the address of the WDC 110 that is operating as a coordinator, but this is generally a programmable register within any WDC 110 , 120 on a Zigbee network such that an alternate trust center (e.g., TC A , TC B , TC C , or TC D ) at a different WDC 120 may be established. Zigbee Pro only defines support for symmetric encryption keys. Zigbee networks employ three types of keys: a network key, a link key, and a master key. A network key is applicable to every Zigbee WDC device 110 , 120 in a given personal area network (PAN) within the aircraft (i.e. a Zigbee local network is identified by one unique PAN identification (ID)). A link key is a key established between two WDC devices 110 , 120 of a Zigbee application. The master key is a key which is used to allow a Zigbee WDC device 110 , 120 to initially join a network. In a high security mode, as defined in the Zigbee Pro specification, the master key is used to establish link keys, and must be configured on new WDC devices 110 , 120 “out-of-band.” “Out-of-band” refers to programming or configuring a WDC device 110 , 120 in an environment different from the wireless network, such as manually typing a key into a WDC device 110 , 120 at the time of manufacturing. [0031] FIG. 2 shows a preferred embodiment of a trusted supplier 210 providing device identifiers (“MAC addresses”) to a global universal trust 200 , which will then issue a set of trusted master keys corresponding to each of the WDC devices' MAC addresses. The trusted supplier 210 then pre-configures the WDC device 110 , 120 with the master key issued by the global universal trust 200 . In particular, as shown in this figure, a trusted Zigbee device supplier/manufacturer 210 sends a request 220 to the global universal trust center 200 for a key for a new WDC device 110 , 120 that it is manufacturing. The request that the supplier 210 sends to the trust center 200 includes the MAC address for the new WDC device 110 , 120 . The trust center 200 has a global key manifest 230 that contains a listing of the specific keys that correspond to particular WDC device MAC addresses. The trust center 200 sends to the supplier 210 a key 240 , which corresponds to the WDC device's MAC address according to the global key manifest 230 . In response, the supplier 210 sends a response 250 to the trust center 200 indicating that the supplier 210 successfully received the key (acknowledgement (ACK)) or did not successfully receive the key (no acknowledgement (NAK)). [0032] Upon initial commissioning of WDC devices 110 , 120 on a new aircraft (or for replacement equipment on an existing aircraft), a trusted Internet connection must be made between the application server 145 and the global universal trust 200 (i.e. trust center 200 ). New WDC devices 110 , 120 that attempt to join the aircraft Zigbee network will cause an aircraft trust center (located at a WDC 110 , 120 ) to communicate with the trust center manager function (TC MGR) 260 , which will make a request to the global universal trust 200 for a master key for the new WDC device 110 , 120 requesting to join the network. Once a WDC device 110 , 120 has been authenticated by the trust center manager 260 , then a key exchange process will occur, and a new encrypted key will be delivered to the new WDC device 110 , 120 joining the Zigbee network. In particular, as shown in FIG. 2 , the trust center manager function (TC MGR) 260 sends a request 270 to the global universal trust 200 for a key for the new WDC device 110 , 120 that is requesting to join the network. The request 270 that the trust center manager function 260 sends to the trust center 200 includes the MAC address for the new WDC device 110 , 120 . The global universal trust 200 sends 280 to the trust center manager function 260 a key 240 , which corresponds to the WDC device's MAC address according to the global key manifest 230 . In response, the trust center manager function 260 sends a response 290 to the global universal trust 200 indicating that the trust center manager function 260 successfully received the key (acknowledgement (ACK)) or did not successfully receive the key (no acknowledgement (NAK)). It should be noted that additional keys and data can be exchanged on the network with the new WDC device 110 , 120 . This includes issuing a network key, which is required for all Zigbee devices 110 , 120 on a given PAN. [0033] A feature of this key management method is an optional means to change the master key to a new value once the pre-determined master keys have been used to allow a WDC device 110 , 120 to join the network. The new master key may be additionally changed at a periodic rate with a last-known master key retained in the event of a master key change error event. If an original master key is lost, after being changed to a new master key, and having rolled past the last-known master key, it is gone forever. Only through a specific trusted new request sequence to the global universal trust 200 may a new pre-determined master key be delivered to a WDC device 110 , 120 whose master key becomes corrupt or lost. This level of security provides another long term layer of assurance that no rogue devices may be allowed to join an aircraft wireless sensor network. [0034] Another feature is the use of a distributed trust center scheme. For large networks of many hundreds or thousands of WDC devices 110 , 120 , having one trust center for the entire network can become unwieldy, and have undesirable latency and memory problems. As such, a distributed trust center allows for a management of subnets (e.g., PANs) by distribution of the trust center key tables 295 efficiently through a secure wired transport. A trust center is also responsible for updating the network key in a normal Zigbee network, and having this distributed trust center function located at the WDC device 110 , 120 enables a more deterministic behavior to occur during a network key update. The additional security feature of changing the master key requires that a list 295 of master keys and of the last-known master keys is maintained at each trust center responsible for a given network. This updated list is also synchronized with the trust center manager hosted function 260 at the application server 145 level to ensure a coherent backup of the trust center data is maintained should a WDC device 110 , 120 , acting as a trust center become non-functional or is replaced. Finally, each trust center is designated as a primary or backup trust center on a given PAN. Stated another way, in at least one embodiment, each PAN has a minimum of two trust centers, where each trust center contains a duplicate of the key list 295 for the WDC devices 110 , 120 within that PAN. [0035] FIG. 3 is a diagram of a two-channel wireless data concentrator (WDC) 120 that is employed by the system of FIG. 1 , in accordance with at least one embodiment of the present disclosure. Each WDC 120 , regardless of how many wireless router channels 125 , 130 are supported, includes a local host Ethernet gateway microprocessor 300 , which contains IEEE-1588 precision time protocol (PTP) hardware support within its TCP/IP MAC layer. Examples of devices that may be employed by the WDC 120 for the local host Ethernet gateway microprocessor 300 include, but are not limited to, a ST Micro STM32F107 device and a ARM Cortex-M3 32-bit RISC core microprocessor. The STM32F107 device, when employed by the local host Ethernet gateway microprocessor 300 for example, acts as the gateway microprocessor 300 and connects to both of the IEEE 802.15.4/Zigbee router microprocessors 125 , 130 by way of one of the serial peripheral interface (SPI) ports that are configured to clock data at a minimum rate of 4 megabits per second (Mbps). The local host microprocessor 300 also contains a software client 310 to handle the time management functions of the PTP network function, which provides the precise time. The local host microprocessor 300 also distributes a precise hardware interrupt signal to each of the 802.15.4/Zigbee router microprocessors 125 , 130 to enable the feature of extended precision time protocol, which is described later in the present disclosure. [0036] FIG. 4 is a diagram of a four-channel WDC 400 , in accordance with at least one embodiment of the present disclosure. In this figure, the four-channel WDC 400 is shown to include one Zigbee green router 125 and four Zigbee standard routers 130 . FIG. 5 is a diagram of an eight-channel WDC 500 , in accordance with at least one embodiment of the present disclosure. In particular, in this figure, the eight-channel WDC 400 is shown to include two Zigbee green routers 125 and six Zigbee standard routers 130 . FIG. 6 is a diagram of a sixteen-channel WDC 600 , in accordance with at least one embodiment of the present disclosure. In this figure, the eight-channel WDC 400 is shown to include four Zigbee green routers 125 and six Zigbee standard routers 130 . [0037] FIG. 7 is a detailed diagram depicting the extended precision time protocol (PTP) operation on a two-channel WDC 120 , in accordance with at least one embodiment of the present disclosure. The microprocessor 300 utilizes a 20.000 megahertz (MHz) (0.5 parts per million (ppm)) clock 700 , which enables a less frequent update period from the PTP master across the Ethernet network than a clock frequency that is less accurate. Also, a low cost 32.768 kilohertz (KHz) watch crystal (Xtal) 710 is used for the Zigbee devices that are nodes (i.e. the Zigbee green endpoint nodes 135 and the Zigbee standard endpoint nodes 140 ). In this case, if a node is battery operated (i.e. a battery operated Zigbee standard endpoint node 140 ), it will be sleeping most of the time at a very low current state. This will require a very low frequency clock source to keep backup time established so that a less frequent synchronization is required. [0038] In this figure, the Zigbee standard router 130 is shown to be transmitting and receiving time synchronization signals to the Zigbee standard endpoint node 140 . In particular, at time T 1 , the Zigbee standard router 130 sends a synchronization signal 720 (i.e. Sync( 1 ) 720 ) to the Zigbee standard endpoint node 140 , and at time T 2 , the Zigbee standard router 130 sends a follow-up signal 730 (i.e. Follow_Up( 2 ) 730 ) to the Zigbee standard endpoint node 140 . At time T 3 , the Zigbee standard endpoint node 140 sends a delay request signal 740 (i.e. Delay_Req( 3 ) 740 ) to the Zigbee standard router 130 . And, finally, at time T 4 , the Zigbee standard router 130 sends a delay response signal 750 (i.e. Delay_Resp( 4 ) 750 ) to the Zigbee standard router 130 . [0039] The PTP protocol introduces a hierarchical firewall nature of synchronization. To represent this synchronization firewall, a time synchronization firewall 760 (i.e. PTP Time Firewall 760 ) is shown to be present within the WDC 120 . This firewall 760 prevents any downstream extended PTP effect from disturbing the primary Ethernet PTP channels 125 , 130 . In other words, the time accuracy of the extended nodes 135 , 140 is strictly governed by the time accuracy and stability of the WDC 120 local host microprocessor 300 . [0040] FIG. 8 is a table 800 that shows the typical drift rates for the two crystal (Xtal) devices employed by the disclosed system for synchronized WDCs for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. In particular, the table 800 shows that the 20 MHz Xtal has better stability (0.5 parts per million (ppm) +/− spec (i.e. nominal frequency)) than the 32.768 KHz Xtal (5 ppm +/− spec). [0041] FIG. 9 is a diagram depicting a modification of a standard Zigbee/IEEE-802.15.4 software stack which is employed by the disclosed system for synchronized WDCs for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. In this modification, PTP time stamping support 900 is added to the MAC layer 910 to enable a low latency capture of the time when packets arrive on the 802.15.4 PHY layer 920 . This time stamp information is then communicated directly to the application layer 930 where a special PTP software application 940 is resident to compute the extended PTP synchronization. Once this operation is completed, then other application objects within the Zigbee endpoint nodes 135 , 140 may take advantage of a high accuracy time stamp. To allow for power down, drift trend information can be captured over time to determine the drift statistics. Referring to FIG. 8 again, one can see that the maximum drift count of the 32.768 Khz clock would be between 9 and 10 counts per minute. Once the drift is monitored in a real system (after synchronization is complete), then the drift can be managed by compensation based on the long term drift trend. A feature of this is a start up period where during certain periodic times, a higher frequency PTP synchronization occurs to determine the absolute drift during the non-critical time endpoint (i.e. node 135 , 140 ) operation period. [0042] Although certain illustrative embodiments and methods have been disclosed herein, it can be apparent from the foregoing disclosure to those skilled in the art that variations and modifications of such embodiments and methods can be made without departing from the true spirit and scope of the art disclosed. Many other examples of the art disclosed exist, each differing from others in matters of detail only. Accordingly, it is intended that the art disclosed shall be limited only to the extent required by the appended claims and the rules and principles of applicable law.

A system, method, and apparatus for a synchronized wireless data concentrator are provided for facilitating a precisely synchronized system of nodes in a wireless sensor network for airborne data systems. The wireless data concentrator contains a plurality of IEEE 802.15.4 radio/micro-processor subsystems, which are connected to a local host microprocessor, which is in turn connected to an aircraft data network. The airplane data network also contains a precision clock source and a plurality of specialized network switches, which have a low-jitter data-path routing capability.

BACKGROUND AND SUMMARY OF INVENTION This invention relates to a storage facility for video cassettes and, more particularly, a structure including a wire carrier adapted to be slidably removed from a case--such as an entertainment center--for labeling, splicing, etc. With the increasing popularity of video cassettes, it is not only desirable but necessary to provide convenient means for storing the same. Unsatisfactory attempts have been tried in the nature of compartmented drawers. These are not only heavy but expensive to construct and thus many people who have accumulated a number of video cassettes are left with no satisfactory storage facility. The instant invention addresses both opportunities for providing suitable cassette storage. In one aspect, a sturdy, installed carrier is provided which is essentially a wire network provided by the manufacturer of the case or other entertainment center. The carrier which includes a generally rectangular perimetric frame made up of four wires comes equipped with a heavy duty slide assembly to be inserted and removed from guide means provided in the case. The carrier includes a plurality of upstanding generally U-shaped wire elements fixed to the perimetric frame and spaced apart so as to receive a plurality of either Beta or VHS in a box video cassettes. Thus, the owner can easily remove the carrier for transport to a convenient work area. In another aspect, the invention addresses the lower cost market where the carrier is provided in knocked-down condition but ready-to-assemble. In this aspect, the generally rectangular perimetric frame is equipped with manifolds along two opposite sides for the installation of the upstanding generally U-shaped wire elements defining receiving spaces therebetween for video cassettes. Advantageously, the carrier can be "tiered" as by superposing through column means, a second or more carriers in vertically spaced relation to the initial carrier. This opens the further opportunity for storing audio cassettes between adjacent wire elements, the audio cassettes having smaller external dimensions than the video cassettes. In either event, the carrier can be provided with column means in the nature of vertically extending bars or the like so as to permit the fastening to the carrier of a pull-equipped drawer front. Thus, the owner has a finished storage facility that can fit within the existing opening of a case without the need of great expense and, more importantly, substantial weight. The invention is described in connection with several embodiments in the accompanying drawing, in which-- FIG. 1 is a perspective view of a case, i.e., an entertainment center, equipped with the inventive carrier and shown with a pull-equipped drawer front attached thereto; FIG. 2 is a fragmentary perspective view of the carrier assembly of FIG. 1 and enlarged relative thereto; FIG. 3 is a fragmentary front elevational view of the showing in FIG. 2 but with the drawer front removed; FIG. 4 is an exploded perspective view of one side of the carrier showing certain details of the slide and guide means associated therewith; FIG. 5 is an enlarged fragmentary view of a modified form of slide and guide means useful in the practice of the invention and which also can serve as a stabilizing means where tiered carriers are employed; FIG. 6 is a perspective view of yet another embodiment of the invention which illustrates a two-tiered assembly of carriers; FIG. 7 is an end elevational view of the showing in FIG. 6 and with a plurality of video cassettes shown in dotted line; FIG. 8 is a front elevational view of a modified form of the invention seen in FIG. 7 and which features audio cassettes (shown in dotted line) in the upper carrier; FIG. 9 is a perspective view of another entertainment center and which shows yet another modification of the invention --this for installation with openable doors on the entertainment center case; FIG. 10 is an exploded, enlarged perspective view of the carrier and associated guide means featured in FIG. 9; FIG. 11 is an enlarged fragmentary front elevational view of the lower left hand corner of the exploded assembly of FIG. 10 and which features the slide and guide means; FIG. 12 is an end elevational view of the carrier of FIG. 10 showing in dotted line a video cassette and on the upper carrier an audio cassette; FIG. 13 is a top plan view of a modified version of the invention such as is suitable for knock down shipment and assembly in the home; FIG. 14 is a front elevational view of the carrier assembly of FIG. 13; and FIG. 15 is a view similar to FIG. 5 but of a modified form of the invention. DETAILED DESCRIPTION In FIG. 1, the numeral 20 designates generally an entertainment center which may take a variety of forms. Generally, however, the center 20 includes a case 21 which is equipped with a front opening leading to a cassette storage space 23. Optionally, the VCR/television 24 may be provided in or with the case 21. The inventive carrier generally designated 25 is seen to be equipped with a drawer front 26 for movement into and out of the storage space 23. Reference is now made to FIG. 3 wherein the numeral 27 in the lower left designates a parting rail normally provided in a case equipped with a drawer. The parting rails--one at the front and one at the rear of the case may be part of the wall means defining the storage space. Details of the case construction are omitted inasmuch as the invention is adapted to be used in a variety of cases, depending upon the owner's choice. The basic building means for the carrier 25 is a perimetric frame 28 defined by two pairs of opposed wire members as at 29 and 30 for those adjacent the sides of the opening, 31 adjacent the front of the storage space and 32 adjacent the rear of the storage space. It will be noted that the carrier 25 is sized to receive 30 video cassettes. This is brought about by providing 10 rows with three cassettes in each row. For example, in FIG. 3 which is only a fragmentary showing, a first cassette VC1 is seen to the left and a second cassette VC2 is arranged in end-to-end relation with VC1. To define the slots or receiving areas for the video cassettes, I provide a plurality of generally U-shaped wire elements 33--see the left hand portion of FIG. 3. These are arranged in parallel, spaced apart relation as seen in FIG. 2 and each of the wire elements 33 is connected to a pair of opposed wire members as at 29 and 30. For example, the connection 34 seen at the lower left hand portion of FIG. 3 is advantageously achieved by spot welding and a similar connection is made relative to the wire member 30 at the other end of each wire element 33. Excellent results are achieved by using a 1/4" diameter steel wire which may be coated with plastic, epoxy, etc. For a less expensive version, I prefer to paint the integrated wire assembly. Also seen in FIGS. 2 and 3 are a plurality of further integrating wire members which extend fore and aft as at 35 and 36. These also can be advantageously spot-welded. In the case of the fore and aft members 35, these are connected between the other two wire members forming the perimetric frame 28 as at 31 and 32. The wire member 36 and its companion 37--see the upper central portion of FIG. 2--are connected to each of the generally U-shaped wire elements 33. In addition to rigidifying the carrier 28, the fore and aft members 36, 37 also define the slots for the receipt of the video cassettes--compare the relationship of the member 36 in the upper central portion of FIG. 3 with the outlines of the cassettes VC1 and VC2. Sideways shifting of the end cassettes (as at VC1 in FIG. 3) is inhibited by the provision of the slide means generally designated 38--see the lower left portion of FIG. 3. The slide means can be better appreciated from a consideration of the exploded view in FIG. 4. In the upper right hand portion of FIG. 4, it will be seen that the wire members 31, 32 are extended horizontally beyond the fore and aft wire member 29 to provide integral extensions 39 and 40. Fixed to the extensions 39 and 40 is a bar 41 which serves to connect the slide generally designated 42. The slide 42 includes an angled bracket 43 of generally Z-shaped cross section. The lower horizontal bar 44 of the bracket 43 is secured by riveting, welding, etc. to the bar 41 on the underside thereof as can be appreciated from the lower right portion of FIG. 11. At its rearward end, the slide 42 is equipped with a roller 45 which provides an anti-friction engagement with the guide means generally designated 46--see the lower left portion of FIG. 4. The guide means 46 is generally C-shaped--again, refer to FIG. 11 for an end elevational view. At its forward end, referring again to FIG. 4, the guide means is equipped with a cooperating roller 47 to complete the anti-friction mounting of the carrier 25 on the guide means 46. As can be appreciated from a comparison of FIGS. 2, 4 and 11, the weight of the forward end of the carrier 25 is placed on the roller 47 by virtue of the upper horizontal flange 48 of the slide 42. The weight of the rear of the carrier 25 is transmitted via the roller 45 to the lower leg of the C-shaped guide means 46--see the portion designated 49 in FIGS. 10 and 11. In turn, the guide means 46 is secured by angle clips 50 to the parting rails--see particularly the extreme left hand portion of FIG. 3 where the front parting rail 27 is seen in fragmentary form. The clips 50 are equipped with slots 50a and 50b as seen in FIG. 4 for ready adjustment of the mounting of the carrier assembly in the case. To facilitate removal of the carrier, the upper portion of the guide means 46 is cut away as at 51--see the lower left hand portion of FIG. 4. This permits the extraction of the roller 45 incident to upward pivoting of the carrier 25. It will be appreciated that an identical but mirror imaged arrangement is provided at the right hand portion of the carrier 25. To indicate to the owner that the drawer is substantially fully extracted from the case, overcomeable stop means 52 are provided in the slide 42--see the upper central portion of FIG. 4. These are depressions provided in the upper bar 48 of the bracket 43 adjacent the rear end thereof, but forwardly of the roller 45. The stop means 52 provide the signal for maximum extraction by engaging the roller 47 at the forward end of the guide means 45--see the lower central portion of FIG. 4. To remove, the carrier forward end is privoted upwardly for the stop means 52 to clear the roller 47 at which time the rear roller 45 can passs through the slot 51. Slide/Guide Modification Reference is made here to FIG. 5 which is a fragmentary view showing a less expensive version of the slide/guide compared to that shown in FIG. 1-4. In FIG. 5, the numeral 127 designates a wall of the carrier-receiving opening and secured thereto is a modified guide means generally designated 146. The guide means 146 is advantageously constructed of plastic material in the form of an elongated plastic block secured by screws or other means to the wall bottom 127. The guide means 146 is equipped with a sidewardly facing groove 153 which receives in bearing engagement the side portion of a fore and aft wire member 141 which is located similarly to the bar 41 of FIGS. 2-4. Here, the cross wire elements are arranged in the same way as in FIGS. 2-4. A suitable detent can be associated with the groove 153 to provide an overcomeable stop means. As will be brought out hereinafter, the same arrangement of slide/guide can be employed on upper tiers of carriers for stabilization. Reference is now made to FIG. 6 where a two-tier construction is depicted. The lower carrier 225 has the same basic construction as that seen with reference to the embodiment in FIGS. 1-4. However, here, the length of the generally U-shaped wire elements 233 is somewhat shorter and thus the carrier 225 is arranged to contain 20 video cassettes. However, the upper carrier generally designated 254 accommodates 20 additional cassettes, making this embodiment capable of supporting 40 video cassettes. This can be appreciated from a consideration of FIG. 7 where the cassettes are designated VC1-4. Column Means For achieving the tiered arrangement, I provide column means in the nature of vertically extending generally U-shaped wires 255 and 256 (see FIG. 6). These are connected between the front and rear wire members 231 and 230 of the lower carrier 225 and the counterpart members 257 and 256 on the upper carrier 254. The upper portions of the U-shaped column means 255 and 256 serve as handles for carrying the heavier assembly and for pulling the column means 255 serves as a handle for pulling the carrier out and pushing the carrier in. Additionally bar means 259 and 260 are provided for mounting a pull-equipped drawer front although in the embodiment illustrated, I prefer to utilize this in a case having openable doors as seen in FIG. 9. However, where 3 or 4 tiers of carriers are employed--as for 80 cassettes--I use the drawer front for additional stabilization. In the event a drawer front is desired, the connection can be that illustrated in FIG. 2 where the drawer front 26 is connected to the vertical bars 59, 60 and 61. Shift Preventing Means As indicated previously, the slides as at 42 restrict the sideways movement of cassettes in the lower carrier 225. To provide the same type of confinement or restraint, I angle the front and rear wire members 257, 258 of the upper carrier 254 so that the fore and aft wire members 262, 263 are somewhat elevated relative to the plane defined by the rest of the perimetric frame and fore and aft members. Audio Cassette Embodiment Reference is now made to FIG. 8 which is essentially similar to the showing in FIG. 7 except for the fact that the wire elements 364 of the upper carrier generally designated 354 have a much lesser height so as to accommodate audio cassettes as at AC1 and AC2. If stabilization is required by the height of the two or more stacked carrier assemblies, the arrangement of FIG. 5 can be advantageously employed whereby the right and left fore and aft members are free of any obstructions on their lower portions so as to be able to ride in a groove-equipped elongated guide means. Modification for Door-Equipped Case Reference is now made to FIG. 9 where the numeral 410 designates generally a somewhat different type of entertainment center--one that is equipped with openable doors 426. This can accommodate a relatively tall, narrow carrier assembly such as is designated 425 relative to the lower carrier and 454 relative to the upper carrier. In this connection, the cross wires have been omitted for ease of understanding but it will be appreciated that lesser height wires are employed as seen in the upper portion of FIG. 12 as at 464 to accommodate audio cassettes. These can have different spacings dependent on whether audio cassettes or discs are to be stored. The embodiment of FIGS. 10-12 insofar as the slide/guide means is concerned is identical to that of FIGS. 1-4, reference having been previously made to the showing in FIG. 11. In the event the openable doors 426 are not either desired or provided, it is possible to install a door front on the assembly of FIG. 10 through the use of the column means 455, 456. Knocked Down Assembly Reference is now made to FIGS. 13 and 14 which show a different type of carrier 525. Again, however, the basic building block of a generally rectangular perimetric frame 528 is employed. However, the fore and aft wire members 529 and 530 have rigidly attached thereto manifolds 565. Each manifold is advantageously a plastic or wood block or a flat metal strip drilled with holes at equal horizontal spacings for the receipt of the ends of the wire elements 533. Thus, the entire carrier can be shipped in a lay flat condition for ready assembly at the cassette owner's home. Also, in this embodiment, I prefer to use U-shaped wire elements which are only 1" high as contrasted to the 2" high wire elements 33, etc. Another modification is seen in FIG. 15 which achieves economies in fabrication and shipment. The guide means 546 is a metal extrusion. To reduce the frictional engagement of the wire 541, I employ a split plastic sleeve 566 ensleeved on the wire 541--or an extra heavy coating of epoxy or other plastic may be employed. Further, the screw or bolt 567 can provide an advantageous means for mounting an L-shaped overcomeable stop 568 for coaction with the wire 533 attached to the wire 541. This also has the advantage of simplicity for installation when the inventive carrier is provided in knocked-down condition. While in the foregoing specification a detailed description of the invention has been set down for the purpose of explanation, may variations in the details hereingiven may be made by those skilled in the art without departing from the spirit and scope of the invention.

A storage facility for video cassettes which employs a wire network carrier based on a generally rectangular perimetric frame with upstanding parallel horizontally spaced apart wire elements adapted to receive video cassettes between adjacent wire elements, the perimetric frame being equipped with slide means for cooperation with guide means in an entertainment center case for insertion and removal.

This application claims benefit, under U.S.C. §119(a) of French National Application Number 03.12221, filed Oct. 20, 2003; and also claims benefit, under U.S.C. §119(e) of U.S. provisional application 60/540,481, filed Jan. 30, 2004. FIELD OF THE INVENTION The present invention relates to polyamide/ thermoplastic polyurethane (TPU) multilayer structures for decorated articles. They are in the form of a film or sheet (usually, the term “film” is used up to a thickness of about 0.5 mm and the term “sheet” beyond that). These structures may be bonded, for example by hot pressing, to an article such as a ski, the polyamide layer being on the outside. In this case, the polyamide layer forms the top of the ski. Before the polyamide/TPU structure is bonded, the ski may be decorated beforehand on the top (that is to say on the opposite part from the sole that slides on the ski), thus, after the polyamide/TPU structure has been bonded and if the TPU layer is translucent or transparent, the decoration may be seen. It is also possible to decorate the ski after the polyamide/TPU structure has been bonded, by subliming inks into the polyamide layer. It is also possible to combine these two methods of decoration. According to another embodiment, the polyamide/TPU structures may be bonded to a polyurethane-foam—the structure obtained is useful, for example, for sports shoes. According to another embodiment, the polyamide/TPU structures may be bonded to a rigid polyurethane—the structure obtained is useful, for example, for making various objects. BACKGROUND OF THE INVENTION U.S. Pat. Nos. 5,616,418 and 5,506,310 disclose a structure consisting in succession of a polyamide layer, a layer made of a polyamide elastomer/grafted polyolefin blend and a layer that may be made of wood from a metal, epoxy or polyurethane. This structure may be a ski, that is to say the epoxy or polyurethane layer is not a thermoplastic layer but is the core of the ski. This part of the ski is not thermoplastic—the epoxy resin is crosslinked even if it is a polyurethane, i.e. a rigid polyurethane. SUMMARY OF THE INVENTION The present invention relates to a multilayer structure comprising a transparent polyamide-based layer and a layer based on a thermoplastic polyurethane (TPU). The invention also relates to a decorated article consisting of an object to which the above structure has been bonded, the polyamide layer being on the outside. The bonding may be carried out by hot pressing or using an adhesive. The decoration may already exist on the object before a structure is bonded; it is also possible to decorate the polyamide layer by sublimation of inks or by combining these two methods of decoration. According to another embodiment, the polyamide/TPU structures may be bonded to a polyurethane foam or to a polyurethane resin. It is also possible to overmould the polyurethane foam or the polyurethane resin to the polyamide/TPU structure placed in a mould, the polyamide layer being adjacent to the mould wall. The structure obtained is useful, for example for making skis or sports shoes. The invention also relates to these structures. Advantageously, the polyamide layer is semicrystalline. Advantageously, the TPU layer is transparent. Each of the layers may be formed from several layers. The structure of the invention has many advantages. The polyamide layer provides: abrasion resistance; impact strength, especially cold impact strength; the possible decoration by sublimation of inks thanks to its high melting point (or glass transition temperature), whereas the TPU and TPU/ABS blends cannot be decorated by sublimation of inks; complete transparency with semiaromatic or semicycloaliphatic (PAs) and their possible blends with aliphatic polyamides of the PA-11 or PA-12 type; UV and chemical resistant glossy appearance; and smooth feel. adhesion to the screen-printing inks, in particular the polyurethane (PU) ink for the decoration, it being possible for these inks to be deposited on lacquers—there is therefore adhesion to the inks and to the lacquers; adhesion to a PU foam; overmoulding TPUs; the TPU layer is such that the adhesion to the PA is very good; and no pretreatment needed. DETAILED DESCRIPTION OF THE INVENTION With regard to the polyamide layer, this comprises at least one polyamide chosen from semiaromatic or semicycloaliphatic PAs and aliphatic polyamides. The aliphatic polyamides may be chosen from PA-11, PA-12, aliphatic polyamides resulting from the condensation of an aliphatic diamine having from 6 to 12 carbon atoms and of an aliphatic diacid having from 9 to 12 carbon atoms, and 11/12 copolyamides having either more than 90% of 11 units or more than 90% of 12 units. By way of example of aliphatic polyamides resulting from the condensation of an aliphatic diamine having from 6 to 12 carbon atoms and of an aliphatic diacid having from 9–12 carbon atoms, mention may be made of: PA-6,12 resulting from the condensation of hexamethylenediamine and 1,12-dodecanedioic acid; PA-9,12 resulting from the condensation of the C 9 diamine and 1,12 dodecanedioic acid; PA-10,10 resulting from the condensation of the C 10 diamine and 1,10-decanedioic acid; and PA-10,12 resulting from the condensation of the C 9 diamine and 1,12-dodecanedioic acid. As regards the 11/12 copolyamides having either more than 90% of 11 units or more than 90% of 12 units, these result from the condensation of 1-amino-undecanoic acid with laurylactam (or of the C 12 α,ω-amino acid). The polyamide layer may also include copolymers having polyamide blocks and polyether blocks, but it is advantageous that this be in a proportion that does not impair the transparency of this layer. The copolymers having polyamide blocks and polyether blocks result in general from the copolycondensation of polyamide blocks having reactive end groups with polyether blocks having reactive end groups, such as, inter alia: 1) polyamide blocks having diamine chain ends with polyoxyalkylene blocks having dicarboxylic chain ends; 2) polyamide blocks having dicarboxylic chain ends with polyoxyalkylene blocks having diamine chain ends, obtained by cyanoethylation and hydrogenation of aliphatic dihydroxylated α, ω-polyoxyalkylene blocks called polyetherdiols; and 3) polyamide blocks having dicarboxylic chain ends with polyetherdiols, the products obtained being, in this particular case, polyetheresteramides. The copolymers of the invention are advantageously of this type. The polyamide blocks having dicarboxylic chain ends derive, for example, from the condensation of polyamide precursors in the presence of a dicarboxylic acid chain stopper. The polyamide blocks having diamine chain ends derive, for example, from the condensation of polyamide precursors in the presence of a diamine chain stopper. The polymers having polyamide blocks and polyether blocks may also include randomly distributed units. These polymers may be prepared by the simultaneous reaction of the polyether with the polyamide block precursors. For example, it is possible to react a polyetherdiol, polyamide precursors and a diacid chain stopper. What is obtained is a polymer having essentially polyether blocks and polyamide blocks of very variable length, but also the various reactants, having reacted in a random fashion, which are distributed randomly along the polymer chain. It is also possible to react a polyetherdiamine, polyamide precursors and a diacid chain stopper. What is obtained is a polymer having essentially polyether blocks and polyamide blocks of very variable length, but also the various reactants, having reacted in a random fashion, which are distributed randomly along the polymer chain. The amount of polyether blocks in these copolymers having polyamide blocks and polyether blocks is advantageously from 10 to 70% and preferably from 35% to 60% by weight of the copolymer. The polyether diol blocks are either used as such and copolycondensed with carboxyl-terminated polyamide blocks or they are aminated in order to be converted into polyetherdiamines and condensed with carboxyl-terminated polyamide blocks. They may also be blended with polyamide precursors and a diacid chain stopper in order to make the polymers having polyamide blocks and polyether blocks having randomly distributed units. The number-average molar mass {overscore (M)} n of the polyamide blocks is between 500 and 10000 and preferably between 500 and 4000 except for the polyamide blocks of the second type. The mass {overscore (M)} n of the polyether blocks is between 100 and 6000 and preferably between 200 and 3000. These polymers having polyamide blocks and polyether blocks whether they derive from the copolycondensation of polyamide and polyether blocks that were prepared beforehand or from a one-step reaction have, for example, an intrinsic viscosity, measured in methacresol at 25° C. for an initial concentration of 0.8 g/100 ml, of between 0.8 and 2.5. Mention may be made, for example, of the composition comprising, by weight: a) from 1 to 99%, preferably 5 to 95%, of a first polyamide characterized by the following chain sequences: in which: y 1 and y 2 are numbers such that their sum y 1 +y 2 is between 10 and 200 and y 1 /y 1 +y 2 =0.5; m, p, m′, p′ are numbers equal to or greater than 0; Z and Z′ in the —NH—Z—CO— and —NH—Z′—CO aliphatic units, which are identical or different, are either a polymethylene segment (CH 2 n where n is an integer equal to or greater than 6 and preferably between 7 and 11, or a sequence containing an amide functional group resulting from the approximately stoichiometric condensation of one or more aliphatic diamines containing at least 4 carbon atoms between the amine functional groups and of one or more aliphatic dicarboxylic acids containing at least 4, and preferably at least 6, carbon atoms between the acid functional groups; —HN—R—NH— is a cycloaliphatic and/or aliphatic and/or arylaliphatic diamine; it being possible for the aromatic diacid to be replaced by up to 30 mol % with an aliphatic dicarboxylic acid containing more than 4, preferably more than 6, carbon atoms between the acid functional groups; and b) 99 to 1%, preferably 95 to 5% of a semi-crystalline polyamide comprising at least 35%, preferably 50%, by weight of an aliphatic unit defined by the sequence —NH—(CH 2 ) n′ —CO— where n′ is an integer equal to or greater than 6 and preferably between 7 and 11, optionally as part of a semiaromatic unit, and/or of an aliphatic unit defined by the sequence containing an amide functional group resulting from the approximately stoichiometric condensation or one or more aliphatic diamines containing at least 4 carbon atoms between the amine functional groups and of one or more aliphatic dicarboxylic acids containing at least 4, and preferably at least 6, carbon atoms between the acid functional groups, that can be obtained using a process that includes a step of blending the said first polyamide and the said semi-crystalline polyamide at a temperature above 300° C., preferably between 300 and 400° C. The semicrystalline polyamide is preferably chosen from the above mentioned aliphatic polyamides and is advantageously PA-11 or PA-12. Advantageously, this composition comprises, by weight: 40 to 90% of the said first polyamide; and 60 to 10% of the said semicrystalline polyamide. Preferably, the composition comprises, by weight: 50 to 80% of the said first polyamide; and 50 to 20% of the said semicrystalline polyamide. Mention may also be made of the polyamide composition comprising a semicrystalline polyamide and a sufficient amount of amorphous polyamide having a glass transition temperature and having no phase change, in order to make it transparent and able to be processed hot without deformation, there can be obtained by blending its constituents at a temperature greater than or equal to 300° C. and by conversion at a temperature greater than or equal to 300° C., the transparency being such that the light transmission coefficient is greater than or equal to 50% measured at 700 nm and for a thickness of 2 mm. Advantageously, this composition comprises, by weight: 65 to 80% of the said semicrystalline polyamide; and 35 to 20% of the said amorphous polyamide. Preferably, this composition, comprise, by weight: 68 to 77% of the said semicrystalline polyamide; and 32 to 23% of the said amorphous polyamide. The semicrystalline polyamide is preferably chosen from the above mentioned aliphatic polyamides and is advantageously PA-11 or PA-12. Mention may also be made of the transparent composition, comprising by weight, the total being 100%: 5 to 40% of an amorphous polyamide (B) that results essentially from the condensation: either of at least one diamine chosen from cycloaliphatic diamines and aliphatic diamines and of at least one diacid chosen from cycloaliphatic diacid and aliphatic diacid, at least one of these diamine or diacid units being cycloaliphatic, or of a cycloaliphatic α,ω-aminocarboxylic acid, or of a combination of these two possibilities and optionally, at least one monomer chosen from α,ω-aminocarboxylic acids or their possible corresponding lactams, aliphatic diacids and aliphatic diamines; 0 to 40% of a flexible polyamide (C) chosen from copolymers having polyamide blocks and polyether blocks, and copolyamides; 0 to 20% of a compatibliser (D) for (A) and(B); 0 to 40% of a flexible modifier (M); with the condition that (C)+(D)+(M) is between 0 and 50%; the balance to 100% being a semicrystalline polyamide (A). The semicrystalline polyamide is preferably chosen from the abovementioned aliphatic polyamides and is advantageously PA-11 or PA-12. Mention may also be made of the transparent composition comprising, by weight, the total being 100%: 5 to 40% of an amorphous polyamide (B) that results essentially from the condensation of at least one possibly cycloaliphatic diamine, of at least one aromatic diacid and optionally of at least one monomer chosen from: α,ω-aminocarboxylic acids, aliphatic diacids, and aliphatic diamines; 0 to 40% of a flexible polyamide (C) chosen from copolymers having polyamide blocks and polyether blocks, and copolyamides; 0 to 20% of a compatibliser (D) for (A) and (B); (C)+(D) is between 2 and 50%; with the condition that (B)+(C)+(D) is not less than 30%; the balance to 100% being a semicrystalline polyamide (A). The semicrystalline polyamide is preferably chosen from the abovementioned aliphatic polyamides and is advantageously PA-11 or PA-12. In these last two compositions, the terms “transparent”, “polyamide”, “semi-crystalline” and “amorphous” have the following definitions: the term “transparent” corresponds to a light transmission coefficient of greater than or equal to 50%, measured at 560 nm and for a thickness of 2 mm, preferably it is greater than or equal to 80%; the term “polyamide” employed in the present description also covers copolyamides, possibly containing third monomers in a proportion that does not impair the essential properties of the polyamides; the term “semi-crystalline” covers (copolyamides) having both a glass transition temperature T g and a melting point T m ; and the term “amorphous” covers polyamides that pass into the liquid or molten state, therefore can be processed, above their T g . These polymers do not have a priori a T m in DSC. However, they may have a T m , but its intensity is then negligible and does not impair the essentially amorphous character of the polymer. With regard to the TPU layer, these TPUs are formed from polyether soft blocks, which are polyetherdiol residues, and hard (polyurethane) blocks that result from the reaction of at least one diisocyanate with at least one short diol. The short chain extender diol may be chosen from the group formed from neopentyl glycol, cyclohexane dimethanol and aliphatic glycols of formula HO(CH 2 ) n OH in which n is an integer ranging from 2 to 10. The polyurethane blocks and the polyether blocks are linked by bonds resulting from the reaction of the isocyanate functional groups with the OH functional groups of the polyetherdiol. Mention may also be made of polyester urethanes, for example those comprising diisocyanate functional units, units derived from amorphous polyesterdiols and units derived from a short chain extender diol. They may contain plasticisers. The TPU may be a blend with copolymers having polyamide blocks and polyether blocks and/or vinylaromatic resins. With regard to the vinylaromatic resin, the term “vinylaromatic monomer” is understood for the purpose of the present invention to mean an ethylenically unsaturated aromatic monomer such as styrene, vinyl toluene, α-methylstyrene, 4-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 2-hydroxymethylstyrene, 4-ethylestyrene, 4-ethoxystyrene, 3,4-dimethylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chloro-3-methylstyrene, 3-tert-butylstyrene, 2,4-dichlorostyrene, 2,6-dichlorostyrene and 1-vinylnaphthalene. The vinylaromatic resin is advantageously a styrene polymer. As examples of styrene polymers, mention may be made of polystyrene, polystyrene modified by elastomers, styrene/acrylonitrile copolymers (SAN), SAN modified by elastomers, ABS, obtained for example by grafting (graft polymerization) of styrene and acrylonitrile onto a polybutadiene or butadiene-acrylonitrile copolymer backbone, SAN/ABS blends, ABS modified by elastomers, SAN modified by elastomers, and blends of SAN and ABS modified by elastomers. The abovementioned elastomers may, for example, be EPR (ethylene-propylene rubber or ethylene-propylene elastomer), EPDM (ethylene-propylene-diene rubber or ethylene-propylene-diene elastomer), polybutadiene, acrylonitrile-butadiene copolymer, polyisoprene and isoprene-acrylonitrile copolymer. These elastomers are used to improve the cold impact strength. The impact polystyrene may be obtained either (i) by blending polystyrene with elastomers, such as polybutadiene, butadiene-acrylonitrile copolymers, polyisoprene or isoprene-acrylonitrile copolymers, or (ii) more usually by grafting styrene (graft polymerization) onto a polybutadiene or butadiene-acrylonitrile copolymer backbone. In the styrene polymers that have just been mentioned, one part of the styrene may be replaced with unsaturated monomers that can be copolymerized with styrene, for example mention may be made of alpha-methyl styrene and (meth)acrylic esters. As examples of styrene copolymers, mention may also be made of polychlorostyrene, poly(α-methylstyrene), styrene-chlorostyrene copolymers, styrene-propylene copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-vinyl chloride copolymers, styrene-vinyl acetate copolymers, styrene-alkylacrylate (methyl, ethyl, butyl, octyl or phenyl acrylate) copolymers, styrene-alkylmethacrylate (methyl, ethyl, butyl, octyl or phenyl methacrylate) copolymers, styrene-methylchloroacrylate copolymers and styrene-acrylonitrile-alkyl acrylate copolymers. In these copolymers, the comonomer content will generally be up to 20% by weight. The present invention also relates to metallocene polystyrenes having a high melting point. Advantageously, the vinylaromatic resin is ABS and SAN/ABS blends. The proportion of TPU in the TPU layer may have any value provided that it is greater than 1%, and advantageously at least 20%, by weight. According to one particular embodiment the polyamide layer is formed from two layers, an outer layer consisting of a polyamide chosen from semiaromatic or semicycloaliphatic PAs and aliphatic polyamides and, for example, either a layer of copolymers having polyamide blocks and polyether blocks, possibly containing a UV stabiliser, or a layer of a polyamide chosen from semiaromatic or semicycloaliphatic PAs and aliphatic polyamides, and possibly containing a UV stabiliser, that is to say the structure of the invention is a multilayer structure comprising, in succession, an outer layer consisting of a polyamide chosen from semiaromatic or semicycloaliphatic PAs and aliphatic polyamides, an intermediate layer which is either a layer of copolymers having polyamide blocks and polyether blocks possibly containing a UV stabiliser or a layer of a polyamide chosen from semiaromatic or semicycloaliphatic PAs and aliphatic polyamides and possibly containing a UV stabiliser, and a thermoplastic polyurethane (TPU) base layer. EXAMPLES TABLE 1 Lower Intermediate Upper layer layer layer Transparency Adhesion Decoration Counterexample PA12 <50% No Yes 1 Counterexample PA11-1 >50% No Yes 2 Counterexample TPU-1 >50% Yes No 3 Counterexample TPU + ABS >50% Yes No 4 Example 1 PA11-1 TPU-1 >50% Yes Yes Example 2 PA11-1 TPU-1 + >50% Yes Yes 10% PEBA2 Example 3 PA11-1 TPU-1 + >50% Yes Yes 50% PEBA2 Example 4 PA11-1 TPU-1 PEBA2 >50% Yes Yes Example 5 PA11-1 TPU-1 PEBA1 >50% Yes Yes Example 6 PA11-1 TPU-1 TPU-2 >50% Yes Yes Example 7 PA11-1 + TPU-1 >50% Yes Yes 20% PEBA1 Example 8 PA11-2 TPU-1 >50% Yes Yes Example 9 PA11-3 TPU-1 >50% Yes Yes  Example 10 PA12-1 TPU-1 >50% Yes Yes  Example 11 PA12-2 TPU-1 >50% Yes Yes  Example 12 PA11-4 TPU-1 >50% Yes Yes Lower Intermediate Upper layer layer Layer UV Impact Endurance Cohesion Counterexample PA12 good good good 1 Counterexample PA11-1 good good very good 2 Counterexample TPU-1 poor good poor 3 Counterexample TPU + ABS poor poor poor 4 Example 1 PA11-1 TPU-1 good good very good good Example 2 PA11-1 TPU-1 + good good very good very 10% good PEBA2 Example 3 PA11-1 TPU-1 + good good very good very 50% good PEBA2 Example 4 PA11-1 TPU-1 PEBA2 good good very good very good Example 5 PA11-1 TPU-1 PEBA1 good good very good very good Example 6 PA11-1 TPU-1 TPU-2 very good very good good good Example 7 PA11-1 + TPU-1 good good very good very 20% PEBA1 good Example 8 PA11-2 TPU-1 good good very good very good Example 9 PA11-3 TPU-1 good good very good good  Example 10 PA12-1 TPU-1 good good very good good  Example 11 PA12-2 TPU-1 good good very good good  Example 12 PA11-4 TPU-1 good good very good very good NB: The blends are preferably manufactured during a prior compounding step but may also be produced at the same time as the processing step. References of the products and definitions Transparency = light transmission at 560 nm for an object 2 mm in thick- ness. Decoration = capability of being decorated by sublimation. UV = Resistance to UV radiation. Impact = resistance to impact at low-temperature (0° C.–40° C.). Endurance = capability of withstanding external mechanical attack: abrasion by sand, blow by an object (for example a ski pole or ski edge). Cohesion = cohesion between the upper and lower layers. PA-12 = 45000 to 55000 Mw nylon-11. PA11-1 = 45000 to 55000 Mw nylon-11/35% PASA blend. TPU-1 = ether-based thermoplastic polyurethane of 85 Shore A hardness. TPU-2 = TPU-1 highly stabilised by UV stabilisers. PA11-2 = 45000 to 55000 Mw nylon-11/35% PAC2/20% PEBA1 blend. PA11-3 = 45000 to 55000 Mw nylon-11/35% PAC2 blend. PA11-4 = 45000 to 55000 Mw nylon-11/25% PAC2/6% AX8840 blend. PA12-1 = 45000 to 55000 Mw nylon-12/30% PAC1 blend. PA12-1 = 45000 to 55000 Mw nylon-12/30% PASA/20% PA11 blend. PAC1 = amorphous polyamide based on cycloaliphatic and ali- phatic monomers, IPD.12/12 polyamide, composed of 75% IPDs.12 and 25% of 12 (lactam 12) by weight, IPD being isophorone diamine. PAC2 = amorphous polyamide based on cycloaliphatic and ali- phatic monomers, IPD.10/12 polyamide, composed of 80% IPDs.10 and 20% of 12 (lactam 12) by weight, IPD being isophorone diamine. PASA = amorphous semiaromatic polyamide PA-12/BMACM, TA/BMACM, IA synthesised by melt polycondensation from bis-(3-methyl-4-aminocyclohexyl) methane (BMACM), lauryllactam (L12) and isophthalic and terephthalic acids (IA and TA) in a 1/1/0.3/0.7 molar ratio. PEBA1 = a copolymer having 5000 PA-12 blocks and 650 PTMG blocks and an MFI of 4 to 10 (g/10 min at 235° C./1 kg). PEBA2 = a copolymer having 1000 PA-12 blocks and 1000 PTMG blocks and an MFI of 4 to 10 (g/10 min at 235° C./1 kg). AX8840 = Lotada ®AX8840, an ethylene-glycidyl methacrylate copolymer having proportions of 92/8 by weight and an MFI at 190° C. at 2.16 kg of between 4 and 6, produced by Atofina.

The present invention relates to a multilayer structure comprising a transparent polyamide-based layer and a layer based on a thermoplastic polyurethane (TPU). The invention also relates to a decorated article consisting of an object to which the above structure has been bonded, the polyamide layer being on the outside. According to another embodiment, the polyamide/TPU structures may be bonded to a polyurethane foam or to a polyurethane resin. It is also possible to overmould the polyurethane foam or the polyurethane resin to the polyamide/TPU structure placed in a mould, the polyamide layer being adjacent to the mould wall. The structure obtained is useful, for example for making skis or sports shoes. The invention also relates to these structures. Advantageously, the polyamide layer is semicrystalline. Advantageously, the TPU layer is transparent. Each of the layers may be formed from several layers.

CROSS-REFERENCE TO RELATED APPLICATIONS This Application claims priority to U.S. patent application Ser. No. 60/295,132, filed Jun. 1, 2001, which is currently still pending. FIELD OF THE INVENTION This invention relates to amine catalysts useful in producing polyurethane foam products. More particularly, it relates to amine catalysts useful for producing polyurethane foam products which have low volatility. The low-volatility catalysts of the invention provide for the manufacture of polyurethane foam products useful as automotive interior components which do not emit vapors over time or under the effects of heat which would otherwise cause nuisance fogging of windshields, and also reduce the chemical content of the air inside vehicles to which a driver or passengers are otherwise exposed to. BACKGROUND The prior art is replete with catalyst systems useful in producing polyurethane foam products which may be used in the interior of automobiles. However, the catalysts used in polyurethane systems of prior art contain volatile amines which may exude out of the foam product and cause fogging on the windshield inside of a car or other vehicle, in addition to exposing the occupants of such vehicles to these amines. World Patent Application WO 01/02459 attempts to alleviate such problems by providing reactive imidazoles with reactive hydroxyl compounds for producing foams with low fogging characteristics. SUMMARY OF THE INVENTION The present invention provides a catalyst system useful in producing a polyurethane foam product which comprises: a) a first catalyst defined by the structure: and b) a second catalyst described by the structure: in which R is hydrogen or any alkyl group having between 1 and 10 carbon atoms, straight-chain or branched; and R″ is methyl or: DETAILED DESCRIPTION The present invention is concerned with the use of a catalyst system comprising N,N-bis-(3-dimethylaminopropyl) formamide as a component, which is represented by the chemical structure: in combination with one or more other catalytic materials which catalyze the reaction between an isocyanate group and a hydroxy group, wherein the hydroxy group is attached to a carbon atom backbone such as in a polyol, or water. The other catalytic materials are often referred to as “blowing” catalysts by those skilled in the art, because they catalyze the reaction between an isocyanate group and water. The catalyst component N,N-bis-(3-dimethylaminopropyl) formamide according to the invention is considered a non-reactive catalyst since it is not consumed during the curing of the polyurethane. Thus, a catalyst system useful in producing a polyurethane foam product according to in one aspect of the invention comprises: a) a first catalyst defined by the structure: and b) a second catalyst described by the structure: in which R is hydrogen or any alkyl group having between 1 and 10 carbon atoms, straight-chain or branched; and R″ is methyl or: The use of the non-reactive catalyst of the invention in combination with a reactive catalyst prevents fogging from occurring. Normally, in the use of a reactive catalyst, some detrimental effects are seen on the physical properties of the resultant loam. According to the present invention, a catalyst system is provided that has a low vapor pressure, is not very volatile, is not completely reactive, and provides a foam with good physical properties. Reactive catalyst components useful as components in producing a foam according to the invention include, without limitation: JEFFCAT® DMEA, JEFFCAT® ZR-70, JEFFCAT® Z-110, JEFFCAT® ZF-10, dimethylaminopropylurea, bis(dimethylaminopropyl)urea, or any material that is known to those skilled in the art as being capable of functioning as a blowing or gelling catalyst in a polyurethane system which contains three heteroatoms or active sights with two carbon spacing which is consumed during the formation of the foam. Non-reactive catalyst components useful as components in producing a foam according to the invention include, without limitation: JEFFCAT® TAP, JEFFCAT® ZF-22, JEFFCAT® DD, tetramethylbutanediammine, dimorpholinodiethylether, JEFFCAT®MEM, JEFFCAT®MEM DM-70, JEFFCAT®MEM bis(dimethylaminoethoxy)ethane, JEFFCAT® NMM, JEFFCAT® NEM, JEFFCAT® PM, JEFFCAT® M-75, JEFFCAT® MM-20, JEFFCAT® MM-27, JEFFCAT® DM-22, Pentamethydiethylenetriamine, Tetramethylethylenediammine, Tertamethylaminopropylamide, 3-dimethylamino-N,N-dimethylpropylamide, or any material that is known to those skilled in the art as being capable of functioning as a blowing or gelling catalyst in a polyurethane system which contains three heteroatoms or active sights with two carbon spacing which is not consumed during the formation of the foam. (JEFFCAT® is a registered trademark of Huntsman Petrochemical Corporation of Austin, Tex.) All of the foregoing JEFFCAT® trademarked materials are available from Huntsman Petrochemical Corporation, 7114 North Lamar Boulevard, Austin, Tex. Polyols useful in providing a polyurethane foam according to the present invention include polyetherpolyol, polymer polyols, and polyesterpolyols having 2 or more reactive hydroxyl groups. Polyetherpolyols include, for example, polyhydric alcohols such as glycol, glycerin, pentaerythritol, and sucrose; aliphatic amine compounds such as ammonia, and ethyleneamine; aromatic amine compounds such as toluene diamine, and diphenylmethane-4,4′-diamine; and/or a polyetherpolyol obtained by adding ethylene oxide or propylene oxide to a mixture of above-mentioned compounds. Polymer polyol is exemplified by a reaction product of said polyetherpolyol with ethylenic unsaturated monomer, such as butadiene, acrylonitrile, and styrene, the reaction being conducted in the presence of a radical polymerization catalyst. Polyesterpolyols include those which are produced from a dibasic acid and a polyhydric alcohol such as, for example, polyethyleneadipate and polyethyleneterephthalates which may include those products reclaimed from waste materials. As for the isocyanate or polyisocyanate component, known organic isocyanates or polyisocyanates may be employed including, for example, aromatic polyisocyanates such as toluenediisocyanate, diphenylmethane-4,4′-diisocyanate, and positional isomers thereof, polymerized isocyanate thereof, and the like; aliphatic polyisocyanates such as hexamethylenediisocyanate and the like; alicyclic polyisocyanates such a isophoronediisocyanate and the like; pre-polymers with end isocyanate groups such as toluenediisocyanate pre-polymer and diphenylmethane-4,4′-diisocyanate pre-polymer which are obtained by the reaction of the above-mentioned substances with a polyol; denatured isocyanate such as carbodiimide denatured substances; and further mixed polyisocyanates thereof. Blowing agents useful in accordance with the present invention are exemplified by low boiling point hydrocarbons, halogenated hydrocarbons, carbon dioxide, acetone, and/or water. Known halogenated methanes and halogenated ethanes may be used as halogenated hydrocarbons. Among them, preferably are chlorofluorocarbon compounds such as trichloromonofluoromethane (R-11), dichlorotrifluoroethane (R-123), dichloromonofluoroethane (R-141b), and the like. The amount of the foaming agent to be used is not particularly limited, but the amount of chlorofluorocarbon to be used is usually not larger than 35 parts by weight, preferably 0 to 30 parts by weight, based on 100 parts of polyol, and the amount of water to be used is not less than 2.0 parts, preferably 3.0 to 20.0 parts. The stabilizer is selected, for example, from non-ionic surfactants such as organopolysiloxanepolyoxyalkylene copolymers, silicone-glycol copolymers, and the like, or a mixture thereof. The amount of the stabilizer is not particularly specified, but usually 0 to 2.5 parts by weight based on 100 parts by weight of polyol. According to the present invention, other auxiliary agents may be added if necessary. They include flame retardants, coloring agents, fillers, oxidation-inhibitors, ultraviolet ray screening agents, and the like known to those skilled in the art. The polyurethane prepared by use of the amine catalyst of the present invention includes flexible foam, HR foam, semi-rigid foam, rigid foam, microcellular foam, elastomer, and the like which are prepared by the conventional known one-shot method, the pre-polymer method, and the like. Among these known processes, particularly preferable is the process for producing polyurethane foam by using a foaming agent which is processed in a combined form such as foil, coating, or border material, or by molding integratedly, with other materials. Said other materials referred to above include resins such as polyvinylchloride resin, ABS resin, polycarbonate resin, and the like, metals, glasses, and the like. Examples of applications of the product include interior articles of automobiles such as instrument panels, seats, head rests, arm rests, and door panels as well as packaging materials, and the like. The amount of the amine catalyst used in a composition from which a foam may be produced in accordance with the present invention is in the range of from 0.02 to 10 parts, more preferably 0.1 to 5 parts, by weight based on 100 parts of the polyol. This includes both the formamide catalyst and the reactive catalyst. In addition, other known tertiary amine catalysts, organic carboxylic acid salts thereof, and organo tin compounds which are usually used as co-catalysts may be employed as auxiliary catalysts. In the process for producing polyurethane using the amine catalyst of the present invention, polyols, polyisocyanates, and foaming agents, stabilizers, and if necessary, other auxiliary agents which are hitherto known, may be employed. The foams in the examples were made on a two component Hi-Tech RIM machine. The A and B pressures were set at 2000 psi. The A and B temperatures were held around 85 F. The throughput of the machine was set at 400 grams/second. Adjustment of the shot time was made to fill a 15 by 15 by 4-inch mold, which was pre-heated to 120 F. After filling the mold, the mold was closed and stuck back in the oven at 130 F for 5 minutes. The foam sample was removed from hot mold and crushed to open up the cells of the foam. A 15-gallon flush of the next material was made in-between the runs run to clean the lines of old material. The B-component tank was charge with 40 pounds of a pre-mixed blend consisting of a polyol component, 43.19 pbw, which had a hydroxyl value of 33.7, water, 1.57 pbw, and 0.21 pbw of silicon surfactant B-8690, Table 1. In addition, the catalyst package consisting of a gelling and blowing catalyst was mixed into the B-component. The amount of catalysts, on a pbw basis, is shown in Table 2 for the runs. The A-component is an isocyanate known as Rubinate® 7304 available from Huntsman International, LLC, although any isocyanate or polyisocyanate, as elsewhere described herein may be used. TABLE 2 Catalysts Amounts Example # Material, pbw 1 2 3 4 5 6 JEFFCAT TD-33A 0.21 JEFFCAT ZR-50 0.36 0.4 N,N-bis-(3-dimethylamino- 0.45 0.36 propyl-)formamide JEFFCAT ZR-50B 0.36 JEFFCAT ZF-22 0.084 0.06 JEFFCAT ZF-10 0.06 0.10 0.13 0.09 Physical properties of foams of the examples are shown in Table 3. TABLE 3 Physical Properties of Example 1-6 Physical property 1 2 3 4 5 6 25% 46.3 50.6 51.7 52.6 45.0 43.7 65% 136.0 147.1 143.2 150.2 133.2 129.7 25% return 34.1 36.9 38.4 38.9 33.9 32.9 sag 2.94 2.91 2.77 2.85 2.96 2.97 compression sets 50% 7.1 14.8 12.8 9.6 8.7 10.0 75% 11.8 43.2 25.8 13.1 12.5 41.9 Wet set 11.9 18.4 18.4 9.8 10.6 22.3 compressions Humid aged 16.3 21.3 20.9 16.0 15.2 21.5 comp sets CLD (avg.) 13.3 14.2 14.5 15.1 13.8 12.1 Density 3.1 3.1 3.0 3.0 3.1 3.1 Load (N) 25% 40.5 43.6 43.9 46.6 42.2 35.8 40% 54.8 58.0 58.6 61.6 56.1 48.2 65% 147.4 148.2 155.1 158.2 141.9 124.8 Stress (Pa) 3927 4222 4251 4517 4089 3470 25% 40% 5310 5616 5679 5969 5431 4673 65% 14280 14356 15020 15321 13748 12094 Example 1 is the control sample. Examples 2, 3, and 6 illustrate what happens when one uses a reactive gelling catalyst. Here, the increase in 70% humid aged compression sets and in the wet set test can be seen. Examples 4 and 5 produced in accordance with the invention (which is a combination of a non-reactive gelling catalyst with a reactive blowing catalyst) yield a foam with good physical properties test results in the 75% humid aged compression sets and the wet set tests. Consideration must be given to the fact that although this invention has been described and disclosed in relation to certain preferred embodiments, obvious equivalent modifications and alterations thereof will become apparent to one of ordinary. skill in this art upon reading and understanding this specification and the claims appended hereto. Accordingly, the presently disclosed invention is intended to cover all such modifications and alterations, and is limited only by the scope of the claims which follow.

Provided herein are catalyst systems useful for providing polyurethane foam products which exhibit low fogging characteristics while possessing favorable overall physical properties when used as interior components of automobiles and other motorized vehicles.

BACKGROUND OF THE DISCLOSURE The present invention is generally directed to a method for treating a doped amorphous silicon surface to enhance electrical contact. The method is applicable to the production of microelectronic circuit devices, and more particularly, is more applicable to the production of thin film amorphous silicon semiconductors, particularly those employed in liquid crystal display matrix addressed systems. A liquid crystal display device typically comprises a pair of flat panels sealed at their outer edges and containing a quantity of liquid crystal material. The flat panels generally possess transparent electrode material disposed on the inner surfaces in predetermined patterns. One panel is often covered completely by a single transparent ground plane electrode. The opposite panel is configured with an array of transparent electrodes, referred to herein as pixel (picture element) electrodes. Thus a typical cell in a liquid crystal display includes liquid crystal material disposed between a pixel electrode and a ground electrode forming, in effect, a capacitor-like structure disposed between transparent front and back panels. In general, however, transparency is required for only one of the two panels and the electrodes disposed thereon. In operation, the orientation of liquid crystal material is effected by voltages applied across the electrodes on either side of the liquid crystal material. Typically, voltage applied at the pixel electrode effects a change in the optical properties of the liquid crystal material. This optical change causes the display of information on the display screen. In conventional digital watch displays and in new LCD displays, screens used in some miniature television receivers, the visual effect is typically produced by variations in reflected light. However, the utilization of transparent front and back panels and transparent electrodes also the permits the visual effects to be produced by transmissive effects. These transmissive effects may be facilitated by subsequently powered light sources for the display including fluorescent type devices. This is typically referred to as back lighting. Various electrical mechanisms are employed to sequentially turn on and off individual pixel elements in an LCD display. Most relevantly, the switch element of the present invention comprises a thin film field effect transistor employing a layer of amorphous silicon. These devices are preferred in many LCD devices because of their potentially small size, low power consumption, switching speed, ease of fabrication, and compatibility with conventional LCD structures. Thin film field effect transistors made from plasma enhanced chemically vapor deposited (PECVD) amorphous silicon (a-Si) and silicon nitride are ideal for matrix addressing of liquid crystal displays. They are fabricated on glass substrates with high picture element density using methods and equipment employed in conventional integrated circuit fabrication. In one process for FET fabrication and LCD displays, a molybdenum contact is made to N + amorphous silicon using two masking steps. After a deposition of an insulative material such as silicon nitride, a layer of intrinsic amorphous silicon and the doping of the upper portions of the amorphous silicon layer, a thin layer of molybdenum is sputter deposited. This film is patterned back into small regions called mesas. Then the silicon nitride/silicon layers are patterned into regions somewhat larger than the mesas and referred to herein as islands. Subsequently, thick molybdenum is deposited on the wafer and patterned into source/drain and data line electrodes. The deposition of the thin molybdenum before subsequent processing into islands has been found to be necessary to ensure reliable contact of molybdenum to the N + silicon. Hence, it is seen that two masking steps are required to form the contact: the mesa and mask and the island mask. Reducing the number of masking steps is desirable because it reduces processing time and in general, increases device yield. SUMMARY OF THE INVENTION In accordance with a preferred embodiment of the present invention, a thin layer of molybdenum, about 50 nanometers in thickness, is sputter deposited on the N + silicon. This molybdenum layer is then removed by etching without any patterning required. The silicon/silicon nitride layer is then patterned into islands as before. Then molybdenum source/drain metal is deposited, patterned and etched and the process is completed. It is the deposition of this thin molybdenum layer and its subsequent removal which is believed responsible for the improvements in electrical contact between the molybdenum source/drain electrodes and the N + amorphous silicon material. It is noted that the present method of processing eliminates the need to form molybdenum mesas prior to formation of the source/drain contacts. Thus one masking step is eliminated. It is also noted that, without the present invention, the mesa/island structure is generally required since the overhang problem due to undercutting of the silicon/silicon nitride layers can develop and cause step coverage problems for the source/drain metallization. Accordingly, it is an object of the present invention to provide a method for improving electrical contact to amorphous silicon materials. It is also an object of the present invention to reduce the number of masking steps required in the formation of amorphous silicon thin film transistors. It is yet another object of the present invention to increase the yield of thin film field effect transistor devices employed in microcircuit applications. It is yet another object of the present invention to reduce the number of masking steps and improve the yield in the manufacture of matrix addressed liquid crystal displays. Lastly, but not limited hereto, it is an object of the present invention to provide a method for treating an amorphous silicon surface, particularly an N + doped amorphous silicon surface, to enhance electrical contact with said surface, particularly when the subsequent contacting material is molybdenum. DESCRIPTION OF THE FIGURES The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of practice, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which: FIG. 1A is a cross-sectional side elevation view illustrating the mesa and island structures present at one stage in thin film FET fabrication; FIG. 1B is a cross-sectional side elevation view similar to FIG. 1A, but more particularly illustrating the deposition of source/drain contact material and the etching of a gap therein to form an inverted field effect transistor device; FIG. 2A is a cross-sectional side elevation view illustrating an initial process step in accordance with the present invention; FIG. 2B is similar to FIG. 2A, but more particularly illustrates the removal of the thin layer of deposited molybdenum resulting in permanent alternation of the N + amorphous silicon surface; FIG. 2C is similar to FIG. 2B, but more particularly illustrates patterning via a mask step to form islands and particularly illustrating the absence of mesa structures; FIG. 2D is similar to FIG. 2C, but more particularly indicating the deposition and patterning of source/drain metallization. DETAILED DESCRIPTION OF THE INVENTION FIGS. 1A and 1B are provided to particularly illustrate the fact that the present invention utilizes one less masking step than is provided by other processing methods. In particular, FIG. 1A illustrates one stage in the fabrication of an inverted, thin film field effect transistor. FIG. 1B illustrates a completed FET structure produced in accordance a process which is different than the present invention. The transistor structures shown in FIG. 1 are seen as being disposed upon a glass substrate 10. This is the typical situation in which these transistors are employed in liquid crystal display devices. However, in general, any insulative substrate material which is thermally compatible and non-reactive with other materials employed in the transistor is suitable for use as a substrate. It is also noted that the transistor structures as illustrated in the figures herein are referred to as inverted since the gate electrode is deposited at a lower point in the transistor structure. In particular, FIG. 1A illustrates gate electrode 12 disposed on substrate 10. The disposition of gate electrode materials and conductive leads typically requires a separate masking and patterning step which is not specifically relevant to the practice of the present invention. However, following formation of metallic gate electrode patterns 12, insulative layer 14, typically comprising silicon nitride is deposited over the substrate. In a similar fashion, a layer of amorphous silicon material 16 is then deposited over insulative layer 14. Doped amorphous silicon layer 15 is then deposited in a conventional fashion using well known methods to produce layer 15 of doped N + amorphous silicon. Next, a layer of metallic material 18 such as molybdenum is employed. Molybdenum layer 18 is employed for the purpose of enhancing electrical contact to the doped N + amorphous silicon material 15. It is the improvement of this electrical contact to which the present invention is specifically addressed. In accordance with the process illustrated in FIGS. 1A and 1B, layer 18 is subject to a masking and patterning operation resulting in the formation of a mesa structure 18 shown in FIG. 1A. It is noted that this particular masking step is the one which is eliminated by the practice of the present invention. Nonetheless, in the process illustrated, a subsequent patterning and masking operation removes portions of layers 14, 15 and 16 so as to form island structures beneath the mesa structure shown. It is noted that if layer 18 is not removed or cut back into mesas prior to deposition and etching of source and drain electrode material, an overhang due to undercutting of the silicon/silicon nitride material is apt to develop and to cause step coverage problems for the source/drain metallization layer. Thus, the separate masking operations for mesa and island structures have been found to be highly desirable to prevent step coverage problems from occurring. FIG. 1B illustrates the completion of a process for forming a thin film field effect transistor from the structure seen in FIG. 1A. In particular, a layer of conductive material 19, preferably comprising molybdenum is deposited and patterned as shown. In particular, patterning of the molybdenum material results in the formation of an aperture or gap which separates source and drain portions of the field effect transistor. It is noted that contact improvement layer 18 is divided into portions 18' as shown. While typically comprising the same material, preferably molybdenum, structures 18' and 19 are shown as distinct in FIG. 1B since the structures actually perform somewhat different functions. In particular, as noted above, molybdenum layer 18 (also designated as 18' after patterning) is relatively thin, namely approximately 50 nm, and serves solely to improve electrical contact to the doped amorphous silicon layer 15. However, a much thicker metallization layer 19 is actually employed to provide source and drain metallization patterning and connection of these device elements to the rest of the circuit. In general, in a liquid crystal display type device as described above, each pixel element is associated with a single FET device such as that shown in FIG. 1B (or in FIG. 2D as is more particularly discussed below with reference to the process of the present invention). It is also noted that the figures of the present invention are not shown to scale and, in particular, the dimensions in the vertical direction have been exaggerated so as to more readily provide a pictorial illustration of the invention and also to provide drawings which are more readily understood by those skilled in the microelectronic fabrication arts. A process for carrying out the present invention is particularly illustrated in FIGS. 2A-2D. The processing required to produce the cross-section in FIG. 2A is typically the same processing that is employed in the construction of the device stage shown in FIG. 1A, as discussed above, up to and including the formation of doped amorphous silicon layer 15. In this regard, it is noted that while the doped region herein is referred to as a separate layer 15, it is nonetheless understood by those skilled in that art that this layer is actually formed by doping a portion of amorphous silicon layer 16 and as such, layers 15 and 16 essentially form a single structure with the exception that the uppermost regions of the amorphous silicon material are doped with a particular polarity dopant such as phosphorus. However, FIG. 2A illustrates the deposition of a thin layer of molybdenum which is preferably sputtered onto the N + doped amorphous silicon. This layer of molybdenum 21 is preferably approximately 50 nanometers in thickness, but may range from about 10 to about 100 nanometers in thickness. It is preferably deposited by sputtering, Also, in marked contrast to other processes, thin molybdenum layer 21 is removed. It is preferably removed by etching with a mixture of phosphoric, acetic, and nitric acids in an aqueous solution. This is typically referred to as a PAWN etch. Most importantly, it is noted that molybdenum layer 21 is removed without any patterning step being employed. This is in marked contrast to the process illustrated in FIGS. 1A and 1B. As a result of the deposition and removal of molybdenum layer 21, it is believed that a permanent alteration of N - doped amorphous silicon layer 15 is produced. This alteration is illustrated by heavy line 20 seen in FIGS. 2B, 2C and 2D. It is this permanent alteration which appears to produce the desirable characteristics of the present invention. In accordance with preferred embodiments of the present invention for forming thin film field effect transistors, the silicon/silicon nitride layer is then patterned into islands as described above. A typical resulting island is shown in FIG. 2C. It is particularly noted that mesa structures are absent in FIGS. 2C and 2D and that no problem of undercutting, overhanging or step coverage is present. Nonetheless, the alteration of the surface of N + doped amorphous silicon 15 renders that surface much more susceptible to electrical contact with subsequently deposited molybdenum material 19 which is patterned as described above to produce source and drain metallization. The resulting structure is seen in FIG. 2D. It has been found that if the deposition of molybdenum layer 21 is omitted from the process, the yield of good electrical contacts is significantly reduced. It is also noted that experiments conducted clearly indicate that it is the deposition and subsequent removal of molybdenum layer 21 which results in the beneficial effects provided by the process of the present invention. In particular, it has been determined by electrical measurements that there is an alteration of the N + silicon surface due to the deposition and removal of the molybdenum. Even after long etching in a PAWN etch to remove the molybdenum, the electrical conductivity of the N + silicon is much higher than for untreated N + silicon. Furthermore, sputter etching of the surface, followed by plasma etching sufficient to remove a small fraction of the N + material, results in a dramatic reduction of the N + conductivity in comparison with that observed from material exposed to molybdenum deposition and removal. This indicates that a permanent alteration of the N + surface has occurred. This alteration persists even through multiple resist processing steps including cleaning steps and oxygen ashing. This altered surface is important for producing a good bond and contact between the thick molybdenum layer 19 which is deposited and patterned into source and drain metallization after formation of the islands. In an alternate embodiment the first molybdenum cap is not removed until just prior to deposition of the source-drain metalization. This molybdenum cap protects the surface from contamination during intermediate processing steps such as ITO deposition and patterning. Subsequent etching of the molybdenum cap is also advantageous in that it strips the Si surface of the contaminants. Accordingly, from the above, it should be appreciated that the process of the present invention significantly improves contact to doped amorphous silicon surfaces. It is further seen that the process of the present invention reduces the number of masking steps employed in the fabrication of thin film amorphous transistors. It is also seen that the process described herein is particularly advantageous for forming FET control device in matrix addressed liquid crystal displays. It is also seen that the processing time and the device yield associated with fabrication of such transistors is also improved by the process of the present invention. While the invention has been described in detail herein in accord with certain preferred embodiments thereof, many modifications and changes therein may be effected by those skilled in the art. Accordingly, it is intended by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.

Electrical contact to doped amorphous silicon material is enhanced by depositing a thin layer of molybdenum on the amorphous silicon surface and subsequently removing it. This treatment is found to permanently alter the silicon surface so as to facilitate and improve electrical contact to the silicon material by subsequently deposited metallization layers for source and drain electrode attachment. The layer of molybdenum which is deposited and removed need only be approximately 50 nanometers in thickness to produce desirable results. The method is particularly useful in the fabrication of thin film, inverted, amorphous silicon field effect transistors. Furthermore, such devices are particularly useful in the fabrication of liquid crystal display systems employing such field effect transistors in matrix addressed arrays used for switching individually selected pixel elements.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an optical switch used for switching optical path lines in an optical communication system, and more particularly, to a semiconductor waveguide optical switch having a switching speed of the order of nanosecond. 2. Description of the Related Art In an optical communication network utilizing optical fibers, the reliability and the economy thereof cannot be fully enhanced by simply connecting two distant places by means of the optical fibers. Therefore, in order to further enhance the reliability and economy, attempts have been made to improve the availability of the optical fibers by providing an optical switch or switches in the optical fibers to switch optical information to a standby line so as to detour obstacles or switch optical information to an unused line. As the optical switch used in such an optical communication system, a mechanical type optical switch for switching the optical paths by mechanically moving the optical parts such as the optical fibers has been put into practical use. However, this type of optical switch has an inevitable problem that switching speed thereof is low and is of the order of millisecond (ms) and the number of switching times is limited by wear of the parts caused by the mechanical switching operations. For the reasons described above, a semiconductor waveguide optical switch has been developed as an optical switch which theoretically has a switching speed of the order of nanosecond (ns) and is free from wear. An optical switch having an X-junction optical waveguide shown in FIG. 1 is known in the prior art. As shown in FIG. 1, thin semiconductor layers of a predetermined composition are sequentially laminated as a lower clad layer, a core layer and an upper clad layer on a semiconductor substrate 51 to form optical waveguides 52 and 53 in a ridge configuration. The optical waveguides 52 and 53 intersect each other in the shape of letter "X" with a branch angle θ° to form a junction point or branch point 54. The entire surface of the structure is covered with a thin insulation film. That part of the thin insulation film which lies on the central portion of the branch point 54 is removed to form a narrow slit-like window (not shown) extending in a direction in which the optical waveguides are formed. For example, an adequate material is vapcuum evaporated on the upper clad layer via the window to form an electrode 55. The electrode 55 is used to inject a current of a predetermined value to the optical waveguides which intersect at the branch point 54. Portions 52a and 53a of the optical waveguides 52 and 53 which lie on one side of the optical waveguides with respect to the branch point 54 constitute input ports, respectively, and the other side portions 52b and 53b thereof constitute output ports, respectively. With the optical switch of the above construction, when a predetermined amount of current is injected via the electrode 55, the refractive index of that portion of the core layer which corresponds to the window and into which the current is injected is lowered by the action of the injected carriers. As a result, light waves incident on the input port 53a are subjected to total reflection at the interface between the current injection area and the non-injection area and then transmitted from the output port 52b to the exterior. On the other hand, when no current is injected via the electrode 55, light waves incident on the input port 53a straightly pass through the branch point 54 and are transmitted from the output port 53b to the exterior. That is, the light waves incident on the input port 53a are transmitted out from the output port 52b or 53b depending on whether a current is injected via the electrode 55 or not. In this way, the optical switch of FIG. 1 performs the switching operation. The current switching characteristic of the optical switch is shown in FIG. 2. FIG. 2 shows the output states of light from the output ports 52b and 53b when the current is injected via the electrode 55 while the light waves are incident to the input port 53a. As is clearly seen from FIG. 2, the light outputs from the output ports 53b and 52b are respectively "1" and "0" when an injected current is 0. On the other hand, when the injected current is larger than a predetermined value (Isw in FIG. 2), the light outputs from the output ports 53b and 52b are changed to "0" and "1", respectively. That is, Isw is a threshold value for the light output. This type of optical switch is called a digital optical switch because of the nature of the response. The injection current Isw may be influenced by the wavelength dependency of the optical switch. However, if the injection current is set to the maximum permissible value (Imax: Imax≧Isw) which can be used in the operable condition of the optical switch, the optical switch will correctly perform the switching function of outputting "0" or "1" in all the operating conditions thereof according to whether the current Imax is injected via the electrode 55 or not. That is, when a current of Imax or more is injected, the wavelength dependency of this type optical switch can be eliminated. This type of optical switch, that is, a digital switch, has the advantages over a waveguide optical switch utilizing the interference mode as will be described later that the switching operation can be attained simply by changing the refractive index of the optical waveguide according to the current injection and the wavelength dependency thereof can be eliminated. Further, it is possible to combine a plurality of the optical switches each having the X-junction optical waveguide so as to constitute an N×N exchange optical switch. However, in order to operate this type of optical switch in an ideal manner, it is necessary to form the light reflection surface at exactly the central position of the branch point 54 at the time of current injection. In order to meet this requirement, it is necessary to form the slit-shaped window in exactly the right portion of the branch point 54 and form the slit with the precisely determined shape and dimensions. However, at present, it is extremely difficult to form the slit-shaped window with such a high precision in the branch point 54 and the window will be formed in a position deviated in a right or left direction from the desired position of the branch point 54 although slightly. With the deviation of the slit-shaped window in a right or left direction, the light reflection surface is accordingly deviated and therefore the optical switching characteristics will be degraded. In particular, in the case of a single mode device, the total width of the optical waveguide is approx. 10 μm and therefore the deviation of the light reflection surface in a right or left direction develops into a serious problem. Further, since the width of the slit-shaped window in the width direction of the optical path cannot be increased beyond a certain extent, the thickness of the light reflection surface portion formed by injecting a current via the window cannot be increased. As a result, light waves which should be fully reflected on the light reflection surface may pass through the light reflection surface, causing a problem that an excellent extinction ratio cannot be obtained. A branching interference type modulator shown in FIG. 3 is known as another example of the optical switch. The modulator is constituted by a combination of Y-junction optical waveguides of the type shown in FIG. 4. As shown in FIG. 4, each of the Y-junction optical waveguides is constructed by sequentially laminating thin semiconductor layers of a predetermined composition as a lower clad layer, a core layer and an upper clad layer on a semiconductor substrate 61 to form an optical waveguide 62. The optical waveguide 62 includes a main optical waveguide 62a as an input port for light waves and two output optical waveguides 62b and 62c branching from the main optical waveguide 62 at a predetermined branch angle θ. Assume that the cross sections of the main optical waveguide 62a and the output optical waveguides 62b and 62c are the same. Then, the light waves incident on the main optical waveguide 62a are transmitted outwardly from the output optical waveguides 62b and 62c as light waves of the equal light outputs. More specifically, the light waves of the light output "1" incident on the main optical waveguide 62a are equally divided and then transmitted out from the output optical waveguides 62b and 62c as light waves of light output "0.5". The construction of the branching interference type modulator constituted by a combination of the Y-junction optical waveguides is shown in FIG. 3. That is, the output optical waveguides 62b and 62c of one Y-junction optical waveguide are respectively connected to the input optical waveguides 62b' and 62c' of the other Y-junction optical waveguide, and electrodes 63a and 63b are respectively formed on the connecting portions of the waveguides. A predetermined voltage can be applied to the electrodes 63a and 63b. With the modulator, light waves incident on the main optical waveguide 62a are equally divided by the output optical waveguides 62b and 62c. In this case, for example, since the guided light propagating from the output optical waveguide 62c to the optical waveguide 62c' is subjected to the phase shift according to the voltage applied via the electrode 63a, the guided light is combined or interfered with the guided light propagating from the output optical waveguide 62b to the optical waveguide 62b'. As a result, the light output of the light wave transmitted out from the main optical waveguide 62a' varies according to the phase difference between the guided light propagating through the optical waveguide path 62c-62c' and the guided light propagating through the optical waveguide path 62b-62b'. In the case of the branching interference type modulator, the mode interference of the light waves propagating through the optical paths is utilized. For this reason, the light output of the light waves to be transmitted is dependent on the polarization and wavelength of the light waves to be propagated. Accordingly, this type modulator can be properly operated only for the guided light of a specified polarization and a specified wavelength. Besides the X-junction optical switch based on total internal reflection as shown in FIG. 1, another type of digital optical switch is also disclosed by Y. Silberberg, et al. in "Digital Optical Switch" in 11th Conference on Optical Fiber Communication (paper No. THA3). Their switch disclosed utilizes a lithium niobate waveguide as a substrate material, and its operation principle is based on "mode evolution". The mode evolution is the phenomenon that the light wave incident on the junction is transmitted only to the output optical waveguide whose propagation constant is larger than that of the other output optical waveguide. This phenomenon was first reported by H. Yajima in the article of Applied Physics Letters (vol. 12, pp. 647-649, 1973) "Dielectric Thin Film Optical Branching Waveguide" and it was applied to the optical modulation by W. K. Burns, et al. who wrote the article entitled "Active Branching Waveguide Modulator", pp. 790-792 of the volume 22 issue of Applied Physics Letters. Y. Silberberg, et al. used this phenomenon to achieve polarization and wavelength insensitive switching with a help of digital response. The lithium niobate digital optical switch, however, has two main drawbacks. First, the device is large in length. This is because the linear electrooptic effect can induce a refractive index difference as small as 10 -4 . A typical electrode length is more than 10 mm. Secondly, a polarization independence is achieved at the cost of applied voltage. In the case of the lithium niobate, a polarization independent optical switch requires a voltage three times higher than that for a polarization dependent counterpart. This is because the linear electrooptic effect is anisotropic, that is, its magnitude depends on the direction of applied electric field and orientation of crystal. OBJECTS AND SUMMARY OF THE INVENTION An object of this invention is to provide a semiconductor waveguide optical switch in which the switching operation is not mechanically effected and therefore wear is not caused by the switching operation and the switching speed is high. Another object of this invention is to provide a semiconductor waveguide optical switch in which it is not necessary to form a window for current injection or voltage application on the branch point of the optical waveguides with high precision and therefore the manufacturing process can be made simple. Still another object of this invention is to provide a semiconductor waveguide optical switch whose switching characteristics are free from the polarization dependency and wavelength dependency. Another object of this invention is to provide a semiconductor waveguide optical switch whose device length is substantially shorter than a lithium niobate digital optical switch. Another object of this invention is to provide a semiconductor waveguide optical switch which exhibits a digital response using a physical effect other than the total internal reflection and mode evolution. Another object of this invention is to provide a semiconductor waveguide optical switch in which degradation in the extinction ratio and increase in the excessive loss can be suppressed without increasing the entire length of the element. In order to achieve the above objects, in an optical switch of this invention, two output optical semiconductor waveguides which make a predetermined angle θ (degree) are connected at the branch point thereof to at least one input optical semiconductor waveguide. Refractive index controlling means for electrically reducing the refractive index of the output optical waveguide is disposed in a position of at least one of the output optical waveguides and apart from the branch point. The refractive index controlling means includes an electrode disposed on at least one of the output optical waveguides and a current is injected via the electrode or a voltage is applied via the electrode to make the two output optical waveguides electromagnetically asymmetrical. Preferably, light attenuation means is disposed between the two output optical waveguides to prevent radiation mode light which has leaked from a portion near the branch point to the exterior of the optical waveguide from being re-combined with the guided mode light in the optical waveguide. Light absorbing means for absorbing the leaked radiation mode light or light scattering means for scattering the leaked radiation mode light may be used as the light attenuation means. Further, a distance between the physical branch point of the two output optical waveguides and the output end of the refractive index controlling means is preferably set to be not less than 100×θ/cos(θ/2) μm. A distance between the closest portions of the refractive index controlling means of the respective output optical waveguides is preferably set to a value smaller than twice the spot size which is defined as half a distance indicated by a light intensity distribution curve representing the light intensity distribution along the cross section of an optical path of the output optical waveguide, the distance being defined by two points on the light intensity distribution curve at which the light intensity is reduced to 1/e 2 (e is the base of the natural logarithms) times the peak value thereof. The optical switch of this invention can be applied to the Y-junction type and the X-junction type, and the refractive index controlling means may be disposed in each branch path or disposed in selected two of the branch paths. In the case of the X-junction optical switch, four branch paths are divided into groups of branch paths which make an angle of (180°-θ°) and the refractive index controlling means is suitably disposed on each branch path of a selected one of the branch path groups. The above and other objects, features and advantages of this invention may be fully understood from the following detail explanation based on the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of the conventional X-junction guided-wave optical switch; FIG. 2 is a switching characteristic diagram of the optical switch shown in FIG. 1; FIG. 3 is a schematic plan view showing the conventional branching interference type modulator; FIG. 4 is a schematic perspective view of a Y-junction optical waveguide used in the modulator shown in FIG. 3; FIG. 5 is a plan view showing a Y-junction optical switch according to this invention; FIGS. 6A to 6D are diagrams showing the cut-off states of the guided mode which are set according to variation in the refractive index of the optical switch of this invention; FIG. 7 is a plan view showing another embodiment of a Y-junction optical switch of this invention; FIG. 8 is a plan view showing an X-junction optical switch of this invention; FIG. 9 is a schematic perspective view showing another embodiment of an X-junction optical switch of this invention; FIG. 10 is a schematic perspective view showing still another embodiment of an X-junction optical switch of this invention; FIG. 11 is a perspective view showing the detail construction of the optical switch of FIG. 7; FIG. 12 is a cross sectional view taken along the line XII--XII of FIG. 11; FIG. 13 is a cross sectional view taken along the line XIII--XIII of FIG. 11; FIG. 14 is a graph showing the injection current-light output characteristics of the optical switch shown in FIG. 11; FIG. 15 is a graph showing the incident polarization direction angle and the branching ratio characteristic of the above optical switch; FIG. 16 is a schematic perspective view of a Y-junction optical switch of this invention having the extinction ratio improved; FIG. 17 is a cross sectional view taken along the line XVII--XVII of FIG. 16; FIG. 18 is a schematic perspective view of a Y-junction optical switch according to another embodiment of this invention and having the extinction ratio improved; FIG. 19 is a cross sectional view taken along the line XIX--XIX of FIG. 18; FIG. 20 is a plan view of a Y-junction optical switch according to still another embodiment of this invention and having the extinction ratio and excessive loss improved; FIG. 21 is a cross sectional view taken along the line XXI--XXI of FIG. 20; FIG. 22 is a plan view showing the arrangement of a Y-junction optical switch when the refractive index control section of the Y-junction optical switch is formed in the ideal condition; FIG. 23 is a plan view showing the arrangement of the above optical switch when the refractive index control section of the Y-junction optical switch is formed farther from the branch point thereof; FIG. 24 is a graph showing the correlation between a value obtained by dividing the distance between the refractive index control sections of the Y-junction optical switch by the spot size of light wave propagating along the output optical waveguide and the extinction ratio and an increased amount of excessive loss; FIG. 25 is a graph showing a curve representing the light intensity distribution on the cross section of an optical path, for explaining the definition of the spot size of the above optical switch; FIG. 26 is a diagram of the refractive index distribution obtained when the refractive index control section C 1 of the optical switch shown in FIG. 20 is operated; FIG. 27 is a diagram of the light intensity distribution showing the propagation state of the light wave and obtained by computer simulation when the optical switch is set in the state to exhibit the refractive index distribution of FIG. 26; FIG. 28 is a diagram of the refractive index distribution obtained when none of the refractive index control sections C 1 and C 2 of the optical switch shown in FIG. 20 is operated; FIG. 29 is a diagram of the light intensity distribution showing the propagation state of the light wave and obtained by computer simulation when the optical switch is set in the state to exhibit the refractive index distribution of FIG. 28; FIG. 30 is a plan view of an optical switch having a distance between the refractive index control sections C 1 and C 2 set to be larger than that of the optical switch shown in FIG. 20; FIG. 31 is a plan view of an optical switch having a distance between the refractive index control sections C 1 and C 2 set to be larger than that of the optical switch shown in FIG. 30; FIG. 32 is a graph showing the relation between the branch angle θ (°) and the length l (μm) of the refractive index control section of a Y-junction optical switch with the extinction ratio set at 10 dB; and FIGS. 33 to 35 are plan views showing the arrangements of the refractive index control sections when the length l of the refractive index control section is changed with the branch angle θ kept constant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In addition to the hints obtained from the prior art described previously, this invention was done by taking account of the fact that a magnitude of inducible refractive index change by current injection or quantum confined stark effect in semiconductor can reach as high as 1%. This is almost two orders of magnitude larger than that of linear electrooptic effect. This fact implies first that a device length of semiconductor optical switch can be shortened substantially as compared with a lithium niobate switch with linear electrooptic effect. It also implies that a new effect other than mode evolution, that is, mode cut-off in a waveguide junction can be used to achieve a digital response which will be described in detail later. Furthermore, refractive index reduction caused by current injection is isotropic, so its magnitude is polarization independent. Therefore, its switching operation is polarization independent by nature even without a help of digital response. Consequently, there is no degradation due to making a switching operation polarization independent, unlike a lithium niobate switch. This invention has been made in view of the background described above, and in the optical switch of this invention, an electrode is disposed on one of or both of the output optical waveguides instead of disposing the electrode on the branch point of the optical waveguide and the electrode or electrodes are activated to make the two output optical waveguides optically asymmetrical, thus performing the switching operation. In this case, the electrode is formed only to make the refractive index of one of the output optical waveguides smaller than that of the other optical waveguide. Therefore, the electrode may be formed with an adequate length and width (shape) on the upper surface of the output optical waveguide, and it is not necessary to form the electrode with such a high precision as required in the case of forming the total reflection surface shown in FIG. 1. As a result, formation of the electrode becomes extremely simple in comparison with the prior art case. FIG. 5 is a plan view of a Y-branching ridge type optical waveguide of this invention. An optical switch having the above optical waveguide is constructed by, for example, forming a GaAs semiconductor substrate with a thickness of 150 μm on a lower electrode of AuGeNi/Au with a thickness of 0.25 μm, forming an n + Al 0 .1 Ga 0 .9 As semiconductor layer with a thickness of 5 μm as a lower clad layer on the semiconductor substrate, forming an n - GaAs semiconductor layer with a thickness of 1 μm as a core layer on the lower clad layer, and then forming a p + Al 0 .1 Ga 0 .9 As semiconductor layer with a thickness of 1.5 μm as an upper clad layer on the core layer. In FIG. 5, the main optical waveguide 1 is used as an input port and branched at the branch point 2 into the output optical waveguides 3a and 3b to form a Y-junction. The branch angle θ of the Y-junction is set to be not greater than 3°, for example, to an angle as small as 2°. Provided that the relative differences in specific refractive index of the core/clad of the output optical waveguides 3a and 3b are Δ 1 and Δ 2 and the core widths thereof are w 1 and w 2 , then Δ 1 =Δ 2 and w 1 >w 2 . Therefore, the propagation constant β 1 of the output optical waveguide 3a becomes larger than the propagation constant β 2 of the output optical waveguide 3b and the output port sides become electromagnetically asymmetrical. A current injection electrode 4 is formed on the output optical waveguide 3a having the propagation constant β 1 . The electrode 4 may be formed by depositing Cr/Au to a thickness of approx. 0.25 μm by the vacuum evaporation method, for example. As shown in FIG. 5, the electrode 4 is formed to cover the upper surface of a portion of a predetermined length of the output optical waveguide 3a. However, the electrode 4 is not necessarily formed on the entire upper surface area of the optical waveguide 3a but may be formed only on a partial upper surface area thereof. When light waves are incident on the main optical waveguide 1 with no current injected via the electrode 4, the light waves will be transmitted out only from the output optical waveguide 3a having a larger propagation constant since the output optical waveguides 3a and 3b are set asymmetrical. If, in this condition, a current is injected via the electrode 4 to reduce the refractive index of the current injected portion of the output optical waveguide 3a by δn so as to set up the relation of Δ 1 -δ<<Δ 2 between the output optical waveguides 3a and 3b, then the relation of β 1 <β 2 can be obtained. When the propagation constant relation between the output optical waveguides is thus reversed, the light waves incident on the main optical waveguide 1 will be transmitted out only from the output optical waveguide 3b whose propagation constant now becomes larger. In this way, an optical switching effect can be obtained. In this case, it is preferable to set the reduced refractive index δn to be larger than the specific refractive index difference of the lateral core and clad portions of the optical waveguide on the output port side. If the refractive index is reduced by the value δn, the light wave propagating in the output optical waveguide can be completely cut off by setting the guided mode to 0. The cut-off of the light wave in the optical switch means that the output optical waveguide physically exists but can be regarded as being not present electromagnetically, that is, having no wave guide action appearing as the result of variation in the refractive index distribution. This is explained by taking the case of current injection as an example with reference to FIG. 6. There occurs a refractive index difference Δn between the waveguide portion (core portion) and the surrounding portion (clad portion) near the cross section of the optical path of the output optical waveguide (FIG. 6A). Assume now that a current I 1 is injected into the waveguide portion. Then, the refractive index of the waveguide portion is reduced by δn by the current injection. That is, the refractive index difference between the waveguide portion and the surrounding portion becomes (Δn-δn) (FIG. 6B). Further, when a larger current I 2 (I 2 >I 1 ) is injected, the refractive index of the waveguide portion is further reduced and can be set to (δn=Δn). That is, no refractive index difference occurs between the waveguide portion and the surrounding portion thereof and the wave guide action due to the presence of the refractive index distribution disappears, thereby setting up a condition in which the presence of the waveguide can be substantially disregarded (FIG. 6C). When the injection current is further increased to I 3 (I 3 >I 2 ), the refractive index of the waveguide portion is further decreased and becomes lower than that of the surrounding portion. Also, in this case, a substantial effect of the waveguide disappears (FIG. 6D). In the optical switch of this invention, the complete cut-off of the guided mode light means that the output optical waveguide is set into the states shown in FIGS. 6C and 6D. FIG. 7 shows an optical switch according to another embodiment of this invention. In the waveguide of the optical switch, output optical waveguides 5a and 5b on the output port side are formed with the same width w and electrodes 6a and 6b are formed on the respective waveguides. In this example, the output optical waveguides 5a and 5b can be made electromagnetically asymmetrical by injecting a current via one of the electrodes 6a and 6b and the light wave incident on the input port can be selectively transmitted out from one of the output optical waveguides 5a and 5b by selecting one of the electrodes via which the current is injected. In this type of optical switch, since the waveguides on the output side can be formed with the same width, connection of the optical fibers at the respective end faces may be made simple. An X-junction optical waveguide is explained as an optical switch according to still another embodiment of this invention with reference to FIG. 8. In this optical waveguide, electrodes 8a and 8b are respectively formed on output optical waveguides 7a and 7b of the same width disposed on the output port. In this embodiment, the waveguides 7a and 7b can be set electromagnetically asymmetrical by controlling the current injection via the electrodes 8a and 8b. Another X-junction guided-wave optical switch will be explained with reference to FIGS. 9 and 10. The optical switch is constructed by two optical waveguides which intersect at an angle θ° to form an X-junction optical waveguide. The optical switch can be regarded as being formed of four branches which are connected together at the intersection. Electrodes 12a, 12b, 13a and 13b are respectively formed on the branches 10a, 10b, 11a and 11b. In this case, a pair of branches 10a and 11b and a pair of branches 11a and 10b individually form an intersection angle of (180°-θ°). With the optical switch of FIG. 9, the optical waveguides 10a and 11a are used as input ports and the optical waveguides 10b and 11b are used as output optical waveguides if no current is injected or no voltage is applied via the electrodes 12a and 13a. In contrast, if none of the electrodes 12b and 13b is used, the optical waveguides 10b and 11b are used as input ports and the optical waveguides 10a and 11a are used as output optical waveguides. That is, the optical switch can be used as an optical switch capable of effecting the bi-directional communication. In the optical switch of FIG. 10, a pair of branches 14a and 15b which, among the branches 14a, 14b, 15a and 15b, make an intersection angle of (180°-θ°) are provided with electrodes 16a and 16b, respectively. With the optical switch of FIG. 10, if θ is smaller than a certain value, for example, greater than 1°, the light wave incident on the branch 14a or 15a is transmitted out equally from both the branch 14b and the branch 15b when no current is injected or no voltage is applied via the electrodes 16a and 16b. In contrast, if a current is injected or a voltage is applied via each of the electrodes 16a and 16b, propagation of the light wave along the optical waveguides 14a and 15b is completely interrupted, and all the light wave incident on the branch 15a is transmitted out from the branch 14b and all the light wave incident on the branch 14b is transmitted out from the branch 15a. In this way, the optical switch has a first switching state in which the branches 14a and 15a are respectively connected to it works as a broadcasting switch and a second switching state in which the branch 15a is connected to the branch 14b. In the optical switch of this invention, a portion of the thin insulation film formed on the surface of the output optical waveguide is removed and metal such as Cr/Au is vacuum evaporated, for example, on the exposed portion to form an upper electrode. In the structure thus obtained, the p-type semiconductor layer, n-type semiconductor layer and lower electrode are arranged in this order under the upper electrode. In an optical switch of the current injection type, a diode formed of the p- and n-type semiconductor layers may be biased in a forward direction by connecting the upper and lower electrodes respectively to the positive and negative terminals of a power source so that a current can be permitted to flow in the p- and n-type semiconductor layers to inject carriers into a portion near the pn junction thereof, thereby making it possible to reduce the refractive index. The refractive index can be reduced by about 1%. This is almost two orders of magnitude larger than that caused by the linear electrooptic effect which is exploited in the lithium niobate. Furthermore, the refractive index reduction caused by current injection itself is polarization independent. Therefore, the switching operation is polarization independent even without the cost of switching efficiency, as is not the case with a lithium niobate switch. In an optical switch of the voltage application type, a diode formed of the p- and n-type semiconductor layers may be reversely biased by connecting the upper and lower electrodes to the negative and positive terminals of a power source so that a depletion layer formed near the pn junction between the p- and n-type semiconductor layers may become larger to cause an electric field in the depletion layer, thereby making it possible to increase or decrease the refractive index. Particularly, in the case of a multiple quantum well structure, the refractive index can be varied by about 1%. This is quite large as compared with the value obtained by the linear electrooptic effect. At this time, the refractive index of the waveguide portion can be controlled by adjusting the amount of injection current or the applied voltage in such a state as shown in FIG. 6. FIGS. 11 to 13 show the detail construction of a symmetrical Y-junction waveguide type optical switch having a current injection electrode. In the structure of FIG. 11, the electrodes 27 are formed to cover the upper surface of the portions of a certain length of the respective output optical waveguides 20a and 20b. However, the electrodes 27 are not necessarily formed on the entire upper surface of the output optical waveguides 20a and 20b but may be formed only on the partial upper surface thereof. Further, the electrode 27 may be formed only on one of the output optical waveguides 20a and 20b. FIG. 12 shows the construction of that portion of the main optical waveguide 29 and the output optical waveguides 20a and 20b of the optical switch in which no electrode to be described later is formed. That is, an n + GaAs semiconductor substrate 21 is formed on a lower electrode 20 of AuGeNi/Au, and a lower clad layer 22 of n + AlGaAs semiconductor, a core layer 23 of n - GaAs semiconductor, a ridge-shaped upper clad layer 24 of n - AlGaAs semiconductor and a cap layer 25 of n - GaAs are sequentially laminated on the substrate 21. The entire surface of the structure is covered with a thin insulation film 28 of SiO 2 . FIG. 13 shows the construction of the electrode forming portion of the output optical waveguides 20a and 20b. In the electrode forming portion, a portion with an adequate width and length of the thin insulation film 28 is removed to form a window 28a. Zn is diffused into the upper clad layer 24 to a predetermined depth through the window 28a, to form a Zn diffusion region 26, and then a current injection electrode 27 of Cr/Au is formed over the window 28a. The optical switch of the above construction in which the branch angle θ was set at 2° and the width of the output optical waveguides 20a and 20b was set at 5 μm was used, and the light output of the light wave transmitted out from the output optical waveguides 20a and 20b was measured while a current to be injected via the electrode 27 was changed with the guided light of the wavelengths of 1.3 μm and 1.55 μm incident on the main optical waveguide 29. The measurement result is shown in FIG. 14. In FIG. 14, marks indicate the state of the output optical waveguide 20a and marks indicate the state of the output optical waveguide 20b. Further, the solid line indicates the case of using the light of the wavelength of 1.3 μm and the broken lines indicate the case of using the light of the wavelength of 1.55 μm. As is clearly seen from FIG. 14, in the above optical switch, the same amount of light is transmitted from the output optical waveguides 20a and 20b with respect to the guided light of the wavelengths of 1.3 to 1.55 μm when a current injected via the electrode 27 is 0. However, when the injection current becomes larger than 250 mA, switching characteristics of "0" or "1" may be obtained. That is, the Y-junction optical waveguide can be used as an optical switch for the guided light in the wavelength range of 1.3 to 1.55 μm by setting the injection current at or more than 250 mA. Incidentally, the electrode was only 1 mm long. This device length shorter by an-order-of-magnitude was achieved because of the very large refractive index reduction induced by current injection. At this time, a slight output loss occurs by the influence of the branch angle θ when the light wave incident on the input port is transmitted out from one of the output optical waveguides. However, the output loss is small and can be neglected in practical use. For example, when the guided light having the spot size of 4 μm and the wavelength of 1.55 μm is propagated in the branch optical waveguide in which the waveguide material is GaAs and the branch angle θ is 2°, the output loss calculated according to the theory of Beam Propagation Method (BPM) is 0.3 dB. When the branch angle θ is 3°, the output loss is 1.6 dB, and when the branch angle θ is 1°, the output loss is less than 0.1 dB. Also, the polarization dependency of the guided light having the above two wavelengths was checked with the injection current set at 100 mA. Assume now that three axes which cross one another at right angles are x, y and z axes and the plane wave propagates in a direction along the z axis. Then, the electric field component of the light wave lies in a plane which crosses the propagation direction at right angles or the x-y plane, and the light wave with the electric component parallel to the x axis is called the x-polarized wave and the light wave with the electric component parallel to the y axis is called the y-polarized wave. However, in general, since the electric component of the light wave is parallel to neither the x axis nor the y axis, the polarization dependency can be measured, that is, changes of the output ratio (branching ratio) between the outputs of the two output optical waveguides 20a and 20b can be measured when the directional angle α (°) of the electric field component is changed. The measurement result is shown in FIG. 15. In FIG. 15, marks indicate the case of using the light of the wavelength of 1.3 μm and marks indicate the case of using the light of the wavelength of 1.55 μm. As is clearly understood from FIG. 15, the switching characteristics of the Y-junction optical waveguide do not exhibit the polarization dependency. In the above example, the optical switch is constructed by the symmetrical Y-junction waveguide. However, the optical switch of the other embodiment may be constructed in the same manner as described above. For example, in the asymmetrical Y-junction waveguide of FIG. 5 in which the output optical waveguides have different widths and the X-junction optical waveguide shown in FIG. 8, the optical waveguide may be constructed with the same cross section as explained in the above example. In a case where a current is injected via the electrode of the optical waveguide, the injection current cannot be infinitely increased. Therefore, in general, the length of the electrode portion is finite and is generally limited to from several hundred μm to several mm. As a result, that portion of the output optical waveguide which lies on the downstream side of the downstream end of the electrode is always set in the light transmittable state. Therefore, the radiation mode light wave may be re-combined with the guided mode light in the output optical waveguide on the downstream of the electrode portion, thereby degrading the extinction ratio. The extinction ratio means, in the example of FIG. 7, for instance, Lmax/Lmin, where Lmax is the main light output from the waveguide 5a when a current is injected into the electrode 6b, and Lmin is the crosstalk light output from the waveguide 5a when a current is injected into the electrode 6a. In order to solve the above problem, it is considered that the branch angle θ between the two output optical waveguides is made extremely small so as to suppress generation of the radiation mode light. Alternatively, it is considered that the electrode length is made extremely long such that the light combined with the radiation mode light is attenuated. However, in the former method, the length of the element is significantly increased, making the whole size of the optical switch larger, and in the latter method, the injection current is increased, thereby increasing the amount of heat generated in the optical waveguide. For this reason, in the preferred embodiment of this invention, a light attenuator is disposed between the two output optical waveguides of the optical switch to positively attenuate the radiation mode light generated at the Y-junction point or the like, thereby suppressing the recombination of the radiation mode light with the guided mode light. As a result, degradation in the extinction ratio can be suppressed. In this type of optical switch, the light attenuation section is formed as a light absorbing section which is formed by disposing (laminating) a metal layer on the upper clad layer of the lateral clad portion between the lateral core portion of the output optical waveguides, or a light scattering section having an uneven surface pattern. Since the radiation mode light generated is attenuated by means of the light attenuating section while propagating along the clad portion, recombination with the guided mode light can be suppressed. Unlike the conventional optical switch, with this type of optical switch having the light attenuating section, it is not necessary to reduce the branch angle θ and increase the element length or increase the electrode length for current injection or voltage application, thereby making it possible to prevent the extinction ratio from being degraded by the radiation mode light. FIGS. 16 and 17 show an optical switch having the light absorbing section as the light attenuating section. In the optical switch, n + -type semiconductor layers 31 and 32 are sequentially formed on a lower electrode 30, and a lower clad layer 33 of n + -type semiconductor and a core layer 34 of n - -type semiconductor are sequentially formed on the semiconductor layer 32. An upper clad layer 35 of p + -type semiconductor is formed in a ridge form on the core layer 34 to form a Y-junction with a branch angle θ and the upper surface thereof is covered with a thin insulation film 36. The main optical waveguide A is an input port for the light wave and the output optical waveguides B 1 and B 2 are output ports for the light waves. A portion of the thin insulation film 36 is removed in the form of a slit with an adequate width and length so as to form windows (only one of them is shown in FIGS. 16 and 17 as a window 36b) in the output optical waveguides B 1 and B 2 . Upper electrodes 37a and 37b are formed in contact with different portions of the upper clad layer 35 via the respective windows by the vacuum evaporation method, for example. The optical absorbing section 38a is formed on the surface of a portion of the upper clad layer which lies between the output optical waveguides B 1 and B 2 branching in a Y-junction form from the main optical waveguide A and extending in a ridge form, and the upper surface thereof is covered with the thin insulation film 36. The light absorbing section 38a is formed to extend from the Y-junction point to the rear or downstream portions of the upper electrodes 37a and 37b. The light absorbing section 38a can be formed of any material which has a property of absorbing the radiation mode light, and may be formed of a metal layer deposited on a predetermined portion of the upper clad layer 35 by the vacuum evaporation method, for example. With the above optical switch, since the radiation mode light generated at the Y-junction point or the like can be absorbed by means of the light absorbing section 38a, recombination of the light in the branched optical waveguide B 1 or B 2 can be suppressed, thereby preventing degradation of the extinction ratio. FIGS. 18 and 19 show an optical switch having the light scattering section as the light attenuation section. In this type of optical switch, the light scattering section 38b is formed to extend from the Y-junction to the rear or downstream portion of upper electrodes 37a and 37b on the surface of the upper clad layer 35 of the ridge-shaped output optical waveguides B 1 and B 2 and the upper surface thereof is covered with a thin insulation film 36. The light scattering section 38b may be formed by, for example, an uneven surface pattern which can be attained by subjecting the surface of the upper clad layer 35 to the etching process, for example. The uneven surface pattern may be any pattern which can scatter light, and may be formed as a diffraction grating pattern or a random pattern having irregular areas randomly distributed. With the optical switch of the above construction, since the radiation mode light generated at the Y-junction point or the like is scattered to the exterior by means of the light scattering section and attenuated, recombination of the radiation mode light with the guided mode light can be suppressed, thereby preventing degradation of the extinction ratio. FIGS. 20 and 21 show a Y-junction guided-wave optical switch of another semiconductor structure. In the optical switch shown in FIGS. 20 and 21, n + GaAs semiconductor layers 41 and 42 are sequentially formed on a lower electrode 40, and a lower clad layer 43 of n + Al 0 .1 Ga 0 .9 As semiconductor and a core layer 44 of an n + GaAs semiconductor layer with a thickness of 1 μm are sequentially laminated on the semiconductor layer 42. An upper clad layer 45 of p + Al 0 .1 Ga 0 .9 As semiconductor is formed on the core layer 44 and the upper surface thereof is covered with a thin insulation film 46. A portion of the upper clad layer 45 is formed in a ridge form with a thickness of 1 μm and a cap layer 48 of p + GaAs semiconductor is formed on the upper surface of the ridge portion of the upper clad layer 45, thus constituting a main optical waveguide A, and output optical waveguides B 1 and B 2 along the ridge portion. The optical path width of the main optical waveguide A and output optical waveguides B 1 and B 2 is set to 6 μm and the branch angle θ between the output optical waveguides B 1 and B 2 is set at 2°. A portion of the thin insulation film 46 covering the output optical waveguides B 1 and B 2 is removed to form windows 46a and 46b having a plane pattern as shown in FIG. 20 on the optical waveguides B 1 and B 2 . Upper electrodes 47a and 47b are formed over the windows to be in contact with the cap layer 48, by vacuum evaporation a suitable electrode material. For example, when a current is injected into the cap layer 48 via the upper electrode 47a or a voltage is applied between the cap layer 48 and the n + -type semiconductor layer 41, the refractive index of a portion of a portion of the output optical waveguide which lies under the window 46a is changed. As a result, all the light wave incident on the main optical waveguide A will be transmitted out from the other output optical waveguide B 2 . In this way, the optical path can be changed or the optical switching function can be achieved. In this case, portions of the output optical waveguides which correspond in shape to the windows 46a and 46b function as refractive index controlling sections C 1 and C 2 . In a case where the optical path is changed by means of this type of optical switch, it is preferable to permit the light wave having propagated along the main optical waveguide A to change the propagation direction immediately behind the branch point A' and propagate along the output optical waveguide B 2 when the refractive index controlling section C 1 is operated, for example. In order to meet the above requirement, for example, it is ideal to form the end face of the refractive index controlling section C 1 near the branch portion A' to be coincident with a plane connecting the branch points A 1 and A 3 , and to form the end face of the refractive index controlling section C 2 near the branch portion A' to be coincident with a plane connecting the branch points A 2 and A 3 , as shown in the plan view of FIG. 22. However, if the refractive index controlling sections C 1 and C 2 are formed with the above configurations and when the refractive index controlling section C 1 is operated to control the refractive index of the output optical waveguide B 1 , the refractive index controlling section C 2 will also be operated since the refractive index controlling sections C 1 and C 2 are set in contact with each other at the branch point A 3 . That is, when refractive index controlling sections which are considered ideal are formed as in the optical switch shown in FIG. 22, it becomes impossible to operate the refractive index controlling sections independently from each other, making it impossible to switch the optical paths. On the other hand, when the end faces of the refractive index controlling sections C 1 and C 2 on the side of the branch portion A' are formed separately from the branch portion A' in the downstream of the optical paths in the optical switch shown in FIG. 23, that is, when the refractive index controlling sections C 1 and C 2 are disposed on the downstream side, the problem which has occurred in the optical switch of FIG. 22 will not occur. However, in this case, a large amount of the light wave having propagated along the main optical waveguide A is distributed at the branch portion A' to the output optical waveguides B 1 and B 2 and then reach the refractive index controlling sections C 1 and C 2 . Therefore, the radiation mode light significantly increases and is re-combined with the guided mode light to degrade the extinction ratio and increase the loss. In order to solve the above problem, according to the optical switch of the invention, the distance X (FIG. 20) between the nearest portions of the refractive index controlling sections C 1 and C 2 is preferably set to be equal to or less than twice the spot size of the light wave which propagates in the output optical waveguide. In general, as the distance between the two refractive index controlling sections at the branch portion of the Y-junction guided-wave optical switch is set smaller, the degradation degree of the extinction ratio becomes smaller. This is because the propagating direction of the light wave having propagated along the main optical waveguide is controlled by the action of the refractive index controlling sections before it is distributed to the two output optical waveguides and as a result it becomes difficult for the guided mode light to be re-combined with the radiation mode light. FIG. 24 shows the relation between the distance between the refractive index controlling sections, which distance is divided by the spot size as explained later, the extinction ratio and increase amount of excessive loss, obtained when a light wave is propagated through the output optical waveguide. In FIG. 24, the solid line indicates variation in the extinction ratio and the broken line indicates variation in the increase amount of the excessive loss. The excessive loss used here is defined as an amount of loss exceeding the loss observed in an ideal case of FIG. 22. Further, the spot size is defined as follows. First, the intensity distribution of light along the cross section of the optical path for the light wave propagated in the branch optical waveguide is drawn by plotting the width of the optical path extending from the center of the optical path along the abscissa and plotting the light intensity along the ordinate. As shown in FIG. 25, a symmetrical light intensity distribution curve p which has a peak value p 1 at the center of the optical path and whose light intensity is attenuated in both width directions of the optical path can be obtained. Two points p 2 and p 3 (p 2 =p 3 -p 1 ×1/e 2 ) at which the light intensity is attenuated to p 1 ×1/e 2 (e is the base of the natural logarithms) can be obtained on the curve p. At this time, the width of the optical path indicated by two perpendicular lines drawn from the points p 2 and p 3 to the abscissa, that is, a distance l indicated in FIG. 25 is defined as twice the spot size. In other words, the spot size is defined as 1/2×l. It is generally said that the extinction ratio is desirably larger than 20 dB. In order to meet the requirement, it is necessary to set the ratio of the distance between the refractive index controlling sections to the spot size smaller than 5 as is clearly seen from FIG. 24. That is, it is necessary to set the distance between the refractive index controlling sections less than five times the spot size. Further, if the permissible maximum value of the increase amount of the excessive loss is set at 1.5 dB, it becomes necessary to set the distance between the refractive index controlling sections less than twice the spot size as is also clearly seen from FIG. 24. Therefore, in order to control the degradation degree of the extinction ratio and the increase amount of the excessive loss according to the above values, it is necessary to set the distance between the refractive index controlling sections less than twice the spot size. In this way, with the optical switch in which the distance between the refractive index controlling sections is set in the above-described manner, the amount of the guided mode light which is re-combined with the radiation mode light is reduced and the extinction ratio can be set larger than 20 dB and the increase amount of the excessive loss can be set less than 1.5 dB. The distance x between the refractive index controlling sections C 1 and C 2 of the optical switch shown in FIGS. 20 and 21 is set at 10 μm. The optical switch of the above construction was used and the spot size of the light wave propagating in the output optical waveguide was set at 5 μm, and the computer simulation of light wave propagation in the output optical waveguides B 1 and B 2 was effected. In this case, the distance x between the refractive index controlling sections was set at twice the spot size. The results of the computer simulation are shown in FIGS. 26 and 27. FIG. 26 is a diagram showing the refractive index distribution obtained in a case where a current was injected only into the refractive index controlling section C 1 . As is clearly seen from FIG. 26, the refractive index of the output optical waveguide B 1 begins to be reduced immediately behind the branch portion A'. FIG. 27 is a diagram showing the simulation of the propagation state of the light wave propagating in the output optical waveguide B 2 while the refractive index controlling section C 1 is set in the same condition as in FIG. 26. As is clearly seen from FIG. 27, a favorable propagation state of the light wave was obtained. At this time, the extinction ratio was suppressed to approx. 20 dB and the increase amount of the excessive loss was suppressed to approx. 1.5 dB. FIGS. 28 and 29 respectively show the state of the refractive index distribution obtained when none of the refractive index controlling sections C 1 and C 2 is used and the propagation state of the light wave in each of the branch optical waveguides obtained at this time. Influence on the extinction ratio and the excessive loss due to variation in the distance x between the refractive index controlling sections C 1 and C 2 was checked. FIG. 30 is a plan view of an optical switch which is formed for comparison with the optical switch of FIGS. 20 and 21 and is similar to the optical switch shown in FIGS. 20 and 21 except that the refractive index controlling sections C 1 and C 2 are moved to the downstream side and the distance x between the nearest portions of the refractive index controlling sections C 1 and C 2 is set at 25 μm. In the optical switch of FIG. 30, the distance between the refractive index controlling sections is set to five times the spot size. The extinction ratio of the optical switch becomes lower than that of the optical switch in which the distance between the refractive index controlling sections is set to twice the spot size and is set to approx. 20 dB. However, increase amount of the excessive loss becomes approx. 3 dB and half the input power is dissipated as a loss. FIG. 31 is a plan view of an optical switch which is formed for comparison with the optical switch of FIGS. 20 and 21 and is similar to the optical switch shown in FIGS. 20 and 21 except that the refractive index controlling sections C 1 and C 2 are further moved to the downstream side and the distance x between the nearest portions of the refractive index controlling sections C 1 and C 2 is set at 50 μm. In the optical switch of FIG. 31, the distance between the refractive index controlling sections is set to ten times the spot size. With this optical switch, since the propagating direction of the light wave incident on the branch portion A' is controlled by means of the refractive index controlling sections C 1 and C 2 after a large portion of the light is distributed to the output optical waveguides B 1 and B 2 , the extinction ratio becomes less than 20 dB and the optical switch cannot be practically used. The light intensity of the radiation mode light increases as the branch angle θ becomes larger. Further, the radiation mode light diverges as it propagates along the upper clad layer disposed between the output optical waveguides and therefore the light intensity thereof gradually becomes smaller. Thus, the light intensity of the radiation mode light is determined depending on the branch angle θ and the length of the refractive index controlling section disposed on the downstream side of the physical branch point A 3 . FIG. 32 shows the correlation between the branch angle θ and the length l of the refractive index controlling section of one of the output optical waveguides in which the light wave propagation is suppressed under a condition that the specific refractive index difference Δ is set at 0 to obtain the extinction ratio of 10 dB. In this case, the specific refractive index difference Δ indicates a value obtained by dividing a difference between the effective refractive index of the core layer of the refractive index controlling section and the effective refractive index of the core layer lying between the two refractive index controlling sections by the effective refractive index of the above core layer. Further, the length l of the refractive index controlling section indicates a length from the physical branch point A 3 to the downstream end portion C 1b (or C 2b ) as measured in a direction parallel to a line bisecting the branch angle θ. Therefore, the relation l=L×cos(θ/2) is obtained between the length l and the actual length L from the physical branch point A 3 to the downstream end portion C 1b (or C 2b ). As is clearly seen from FIG. 32, recombination of the radiation mode light can be suppressed and the extinction ratio of more than 10 dB can be obtained by setting the relation l≧100×θ. That is, when the relation L≧100×θ/cos(θ/2) is set between the branch angle θ and the the length L of the refractive index controlling section, an optical switch in which degradation of the extinction ratio is suppressed to a minimum can be obtained. Influence of variation in the length L of the refractive index controlling section on the extinction ratio was checked while the length L was variously changed. FIG. 33 illustrates an example of a medium length L, FIG. 34 illustrates an example of a sufficiently large length L, and FIG. 35 illustrates an example of an excessively small length L. Symbols, C 1 , C 2 , C 1b , C 2b , A, B 1 , B 2 , A 3 , θ, L and l indicate the same meanings as mentioned above. FIG. 33 shows an optical switch in which the branch angle θ is set at 2° and l is set at 200 μm. The length L of the optical switch is 200/cos 1°=200.03 (μm) and is equal to the value of 100×θ/cos(θ/2). With the optical switch, the extinction ratio of equal to or larger than 10 dB could be obtained and therefore the optical switch can be applied for the optical exchange or the like. FIG. 34 shows an optical switch in which the branch angle θ is kept unchanged and the length l is further increased in comparison with that of the optical switch shown in FIG. 33 and is set to 500 μm. At this time, L is 500/cos 1°=500.08 (μm) and is larger than 100×2/cos 1°=200.03. In this case, the extinction ratio equal to or larger than 20 dB could be obtained. FIG. 35 is a plan view of an optical switch formed for comparison with the optical switch of the above embodiment in which the branch angle θ is set at 2° and the length l is set at 50 μm. At this time, the length L of the optical switch is 50/cos 1°=50.008 (μm) and is smaller than the afore-mentioned value of 100×2/cos 1°=200.03 (μm). In this case, significant recombination of the radiation mode light occurred and the extinction ratio of only a few dB could be obtained. Therefore, the optical switch cannot be practically used.

An optical switch includes at least one input optical semi-conductor waveguide. Two output optical semiconductor waveguides are connected at a branch point to the input optical waveguide, and diverge from the branch point with a preset angle θ (degree) between them. A refractive index controlling portion is located on at least one of the output optical waveguides and away from the branch point. The refractive index controlling portion effects a light mode cut-off by electromagnetically causing a reduction of the refractive index of the associated output optical waveguide.

FIELD OF THE INVENTION The present invention concerns a method for improving the conservation of a photographic product with a cellulose ester type support. BACKGROUND OF THE INVENTION The preservation of cinematographic films with a support of the cellulose ester type is an important criterion for producers, directors and institutions keen to safeguard their heritage. Different types of cellulose ester have been used, such as cellulose acetate butyrate, cellulose acetate propionate and cellulose triacetate. These types of support offer a certain advantage over cellulose nitrate, which was abandoned in the 1950s owing to its instability and the danger that it represented. However, archiving film of the cellulose ester type, exposed and developed, is made very difficult by the decomposition of the support, which is accompanied by a release of acetic acid, and hence the name "vinegar syndrome" given to this phenomenon described in the literature, see for example Adelstein, PZ et al, SMPTE Journal 1995, May, 281, or Ram, T et al, J. Imag. Sci. 1994, 38(3), 249. Certain chemical compounds required in the processing of film, along with atmospheric contaminants (hydrogen peroxide, sulphur dioxide, ozone, nitrogen oxide, etc) also contribute to the deterioration of the images contained on film with a triacetate support. U.S. Pat. No. 5,215,192 describes a method which improves the archiving of a photographic product which has been exposed and developed. This patent describes the use of zeolite-based molecular sieves having the ability to absorb moisture, acetic acid and residual solvents. These molecular sieves are packaged in sachets placed inside archive canisters. However, since most of the gaseous releases take place in the area where the film is winding between the reels (see U.S. Pat. No. 5,215,192 column 4, lines 36-41), the aforementioned technique does not inhibit deterioration sufficiently. This is why the present invention recommends a treatment applied directly to the film to be archived, which enables the level of acetic acid, moisture and residual solvents to be controlled, while leaving a transparent protective layer which preserves the quality of the image. The applicant recently described a fibrous inorganic polymer of aluminium and silicon and a method for synthesising it in the international patent application PCT/EP 95/04165, filed on 24 Oct. 1995, entitled "Alumino-silicate polymer and method for preparing it". The present invention has as its object the use of a composition of the aforementioned fibrous inorganic polymer to improve the conservation of a photographic product with a cellulose ester type support. SUMMARY OF THE INVENTION The composition used according to the invention is a film-forming aqueous composition which comprises a fibrous alumino-silicate polymer of formula Al x Si y O z in which x:y is between 1 and 3, and z is between 2 and 6. According to one embodiment, the composition also comprises a water-soluble polymer binder. According to the present invention, the polymer binder, when there is one, is water-soluble, that is to say it can be mixed with water in proportions enabling a person skilled in the art to obtain a composition which is homogeneous and optically clear to the naked eye, in a temperature range between room temperature and 75°. The binder must enable a transparent composition to be produced which is applicable in a layer using the usual techniques (see Research Disclosure, publication 17643, December 1978, chapter XVA, page 27). A person skilled in the art will be able to adjust the concentrations of the components so as to obtain a composition whose viscosity falls within a range of between 4 and 20 centipoise. Useful polymer binders comprise proteinaceous binders, for example deionised gelatine, gelatine derivatives, hydrophilic cellulosic substances such as methylcellulose, polyalkylene glycols such as polyethylene glycols, with a molecular mass between 103 and 106, polyvinyl alcohol, polyethylene oxides and polyacrylamides. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the composition according to the invention, the alumino-silicate is a fibrous substance, described in the aforementioned international patent application PCT/EP 95/04165. According to this patent application, the alumino-silicate is obtained by means of a method comprising the following main steps: (a) a mixed alcoxide of aluminium and silicon or a precursor of such an alcoxide is mixed with an aqueous alkali, at a pH between 4 and 6.5 and advantageously between 4.6 and 5.6, keeping the aluminium concentration between 5×10-4M and 10-2M, (b) the mixture obtained in (a) is heated at a temperature below 100° C. in the presence of a silanol group, for example in the form of divided silica, for a sufficient period to obtain a complete reaction resulting in the formation of a polymer, and (c) the ions are eliminated from the reactional mixture obtained in (b). The reaction in step (b) is considered to be complete when the reactional medium no longer contains any cations other then those of the alkali, that is to say when the Al and Si ions have been consumed. According to one embodiment, the initial product, at step (a), is a precursor which is the product of the hydrolysis reaction of an aluminium salt, for example aluminium chloride, and a silicon alcoxide. The composition according to the invention has a viscosity which is such that it can be layered easily. This viscosity will be between 4 and 20 centipoise. The composition according to the invention can contain different additives normally used in compositions of this type and designed to improve the characteristics which assist layering, or the stability of layers, for example thickeners, wetting agents, surfactants or preservatives. The alumino-silicate content of the composition will be adjusted by persons skilled in the art so as to obtain a layer after drying which has an Al+Si content between 50 and 100 mg/m2 (per treated face), and ideally between 70 and 90 mg/m2 (per treated face). The alumino-silicate polymer can be used in several ways. The cellulose ester support can be treated before the application of the photographic layers (as a substratum or under-layer), or after the application of the photographic layers (as a top layer), by means of a film-forming aqueous composition as described according to the invention. It is also possible to treat an exposed, developed film by passing it through a bath with such a composition or spraying such a composition onto its surface. In particular, the film to be treated can be either immersed in an extra bath, at the end of the photographic processing line, with a temperature between room temperature and 40° C., or coated onto both faces by means of a top layer based on the said composition using normal techniques (see Research Disclosure, publication 17643, December 1978, chapter XV-A, page 27). The layer obtained, after drying, has a thickness of at least 1 μm. In general terms, the binder used is not initially cross-linked, so that an optimum mixture with the alumino-silicate polymer is promoted, but the layer can, nonetheless, be tanned during a subsequent step, by means of the tanning agents normally used in the preparation of photographic products (see Research Disclosure, publication 36544, September 1994, chapter II-B, page 508). Where the binder is gelatine or a gelatine derivative, it is necessary to adjust the pH of the alumino-silicate polymer solution to a value below the isoelectric point of gelatine to avoid precipitation. The inside of the storage canisters for the reels can also be treated by coating with a top layer of the said composition. The reels can be stored in canisters made of plastic (polyethylene, polypropylene, polycarbonate, etc) or metal. In order to evaluate the efficacy of the method according to the invention, a method of accelerated ageing is used which is described in the literature, see for example Adelstein, PZ et al, SMPTE Journal 1995, May, 281, or Ram, T et al, J. Imag. Sci. 1994, 38(3), 249. The following examples illustrate the invention. EXAMPLE 1 An alumino-silicate polymer is prepared according to the method in Example 2 of the aforementioned patent application PCT/EP 95/04165. This alumino-silicate comprises 3.88 g of Al+Si/l, with an Al:Si molar ratio of 2. For a mixture of 1031 g of this alumino-silicate (4.0 g Al+Si), 0.18% by weight of Tween 80™ non-ionic surfactant is added with respect to the Al+Si weight. While stirring, the above composition is mixed with 400 g of an aqueous solution of Type IV photographic gelatine containing 1% by weight of dry gelatine while keeping the temperature at 40° C. The volume is adjusted to 1600 ml using water to obtain an Al+Si content of 2.5 g/l. The stirring of the mixture is continued for 1 hour 30 minutes while keeping the temperature at 40° C. This composition is applied to both faces of a film with an exposed and developed cellulose triacetate support. The covering on this film after drying is around 80 mg/m2 per face. The control film (film B), which is identical except that it does not include a layer of the composition and which comes from the same sample as film A, is placed in a second airtight metal canister identical to the preceding one. The two canisters are placed in the same oven at 80° C. for 21 days. The relative humidity level within the canisters is around 50%. This test simulates an accelerated ageing of the film. EXAMPLE 2 An alumino-silicate polymer is prepared according to the method in Example 2 of the aforementioned international patent application PCT/EP 95/04165. This alumino-silicate comprises 2.5 g Al+Si/l, with an Al:Si molar ratio of 2. This composition is applied directly to both faces of a film with an exposed and developed cellulose triacetate support. The covering of Al+Si on the top layer is around 80 mg/m2 per face after drying. The treated film (film C) is placed in an airtight metal canister. A control film (Film D) which is identical except that it does not have a top layer of the composition and which comes from the same sample as film C, is placed in a second airtight canister identical to the preceding one. The two canisters are placed in the same oven at 80° C. for 21 days. The relative humidity level within the canisters is around 50%. This test simulates an accelerated aging of the film. Results Following the treatments in Examples 1 and 2, the quality of the films A, B, C and D is assessed visually according to the following criteria: A=the support shows no sign of deterioration and the quality of the image is excellent; B=the support shows no sign of deterioration and the quality of the image is acceptable; C=the support has deteriorated and the quality of the image is unacceptable; The results obtained are shown in the following table: ______________________________________Quality of support and image______________________________________Example 1 Film A B Film B CExample 2 Film C B Film D C______________________________________ These results show that exposed, developed photographic films with a support of the cellulose ester type, which have undergone a treatment according to the invention, exhibit, after an accelerated ageing test, a quality of support and image which are much higher than the same films when untreated. In order to assess the ability of the protective top layer to adsorb acetic acid, a sample of blank cellulose triacetate is treated with a composition, according to the method in Example 2, having an alumino-silicate content expressed in terms of Al+Si of 5.87 g/l. The covering with Al+Si of the layer obtained after drying is around 200 mg/m2 per face. This treated support is placed in an airtight metal canister. A control sample of blank cellulose triacetate, untreated and identical to the previous one, is placed in a sealed canister identical to the previous one. These two canisters are placed in the same oven at 80° C. for 21 days. The relative humidity level within the canisters is around 50%. After heating, the treated support has an acceptable physical appearance while the untreated support has deteriorated. By scraping the treated support with a razor blade, a sample of the layer of alumino-silicate is obtained in the form of powder. A sample of the untreated support is prepared in powder form. These two samples are analysed by mass spectroscopy (Nermag R-10-100 model) under the following operating conditions: vacuum=10-5 torr starting temperature=30° C. heating: 20°/min maximum temperature=300° C. introduction of the sample=direct mode. The sample from the treated support clearly shows the presence of acetic acid, while the sample from the untreated support does not exhibit this characteristic. The layer of alumino-silicate polymer adsorbs the acetic acid and acts as a barrier against the release of acetic acid, which stabilise the cellulose ester type support. The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

The present invention improves the conservation of a photographic product with a cellulose ester type support. The present invention involves coating on the support or the photographic product with a transparent film-forming aqueous composition. The composition is a fibrous alumino-silicate polymer of formula Al x Si y O z in which x:y is between 1 and 3, and z is between 2 and 6. The support can be treated before the application of the photographic layers (as a substratum or under-layer) or after the application of the photographic layers (as a top layer). It is also possible to treat an exposed, developed film by applying a top layer of the said composition.

BACKGROUND OF THE INVENTION The present invention relates generally to a safety system for eliminating any risk of liquids being carried to the torch nose-piece or to the vent hole, during burning or dispersion of the gases associated with the production or with the treatment of hydrocarbons on land and off-shore. The present invention relates to a safety system for eliminating any risk of liquids being carried to the torch nose-piece during burning of the gases associated with the production of hydrocarbons, more especially off-shore. Generally, it is known that liquids carried along in the nose-piece of a torch, particularly resulting from choking up of the gas/oil or gas/condensate separators, constitutes a serious danger in hydrocarbon treatment and production installations and in particular in fixed or floating off-shore production installations. In fact, on leaving the nose-piece of the torch, the oil or the condensates carried along by the gas are set on fire and fall flaming back down on to the installation or in the immediate vicinity thereof, thus endangering the whole installation and the lives of the whole of the staff. This danger is all the more important, in off-shore installations, since the staff risk being imprisoned on the platform or the floating burning support and since further the oil or the condensate floating on the sea may form a sheet of fire prohibiting any possibility of evacuation. To try to eliminate this risk, one of the best arrangements used up to present is formed by placing, between the liquid hydrocarbon driving source and the nose-piece of the torch, three capacities, namely a separator, a safety purifying installation and a torch foot tank, mounted in series in the gas flow chain, these capacities being respectively equipped with three high level detection devices which cause, should the liquid level exceed a predetermined height, closure of the hydrocarbon feed of the installation. Furthermore, in such an installation, the torch foot tank has, or may have, a liquid retention capacity, such that it allows sufficient time for the hydrocarbon feed valves of the installation to be closed manually. However, it is clear that in any case, principally in the case where the torch is vertical or subvertical on the production support, the safety of the staff and of the whole of the platform will depend: on the operation of the automatic detection and mechanical actuation automatic devices which are always subject in time and depending on the operating conditions to break-downs, and as a last resort, on the time in which the liquid is retained in the torch foot tank, which is dimensioned with respect to the anticipated duration of human intervention, which is always problematic and the hazardous character of which does not conform to good safety logic. Furthermore, it should also be noted that the torch foot tank, which is generally placed in a low part of the installation, because of its dimensions risks causing considerable, even inacceptable inconvenience. SUMMARY OF THE INVENTION The invention has then as its aim to do away with all these disadvantages. It thus proposes a safety system comprising, in the gas flow chain between the liquid drive source and the nose piece of the torch, at least one chamber defining an excess volume or capacity such as for example a torch foot tank provided with an overflow column discharging below the level of the sea, at a given distance from its tapping point in said capacity. Thus, a particularly simple and reliable safety system is obtained possibly completing or even replacing the usual safety systems, and which has the advantage of using no detection device and no mechanical means subject to break-downs. Thus, in the case of a slow or sudden derangement of the system, the excess liquid will be discharged into the sea with a very low fire risk probability since: it would require a considerable hot point in the zone where the liquid will reach the surface of the sea to cause ignition thereof, because of the depth at which it is discharged, and because of the sea currents which exist in most sites, the liquid will only rise to the surface at a certain distance from the installations. Furthermore, the overflow column, in some applications, will be equipped with a device for discharging inside the column different products whose main purposes will be, but not limitatively so, to delay or prevent the liquid hydrocarbons from rising to the surface, reducing, delaying or inhibiting the pollution caused by the hydrocarbons. Moreover, in some applications, the torch will be equipped with manual or automatic ignition and extinction means allowing the flame to be initiated or blown out in different operating configurations or for safety reasons or similar. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will be described hereafter, by way of non limiting examples, with reference to the accompanying drawings in which: FIG. 1 is a schematical representation of a first production installation equipped with a safety device according to a first embodiment of the invention; FIG. 2 is a schematical representation of a second installation requiring less space and equipped with anti-pollution means; FIG. 3 is a schematical representation of a third installation in which the barrel of the torch serves as torch foot tank. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, the installation comprises first of all a liquid hydrocarbon drive source formed by an intake separator 1 receiving the crude oil or the gas through an intake pipe 2. This separator is equipped conventionally with a normal oil or condensate take-off circuit 3 and a gas outlet connected to a gas flow chain 4 as far as the nose-piece 5 of the torch. This gas flow chain 4 comprises, between separator 1 and the nose-piece of torch 5, a torch foot tank 6 equipped, in a conventional way, with a droplet take-off circuit 7 comprising a pump 8 or not. Separator 1 and torch foot tank 6 are both equipped with a high liquid level detection circuit 30, 32 (liquid level detectors) for closing, should the liquid level become abnormally high, the gas or crude oil feed of the installation. According to the invention, this installation comprises an overflow column 10 tapped (tapping 11) on the torch foot tank 6 at a position corresponding to a maximum predetermined level emerging below the level 12 of the sea at a distance L R below the tapping 11 on said tank 6. This overflow column 10 is equipped with a discharge conduit opening or device 14' and means 13' for removing liquid hydrocarbons overflowing in the overflow column so as to reinsert them into the normal treatment circuits. These take-off means will be formed, for example, by different types of pumps or liquid or gas ejectors (gas lift). They may be positioned during construction of the installation or later and they may be removable or not. Thus, under normal operating conditions, the two level detection systems will inform the operators of a malfunction and will turn off the crude oil intake if the malfunction has not been corrected. Should a sudden derangement and non operation of the two level detection circuits occur, the liquids will be discharged into the sea through the overflow column 10, the torch continuing to be fed with gas, until the defect has been corrected or unitl the crude oil intake has been closed manually or automatically. Thus a circuit is obtained of very high safety. However, because of the dimensions of the torch foot tank 6, it presents a considerable disadvantage (which may be eliminated by means of the arrangements which will be described more especially with reference to FIGS. 2 and 3). It should be stated that, to obtain acceptable operation, the overflow column 10 must satisfy given dimensioning criteria complying with at least two main conditions, namely: to prevent the liquids rising in the torch barrel 13, should choking occur; to prevent gas leaving through the lower end 14 of the overflow column 10 during normal service. These conditions may be expressed as follows: (A) To avoid choking up of the torch foot tank 6 or the rise of liquids in barrel 13, the flow of liquids into the sea should be ensured, which implies that the following equation (1) is at least satisfied, without taking into consideration the different pressure drops in the ducts: P.sub.1 +(L.sub.1 ×d.sub.o)9.81≧P.sub.atm +(L.sub.R -L.sub.1)(d.sub.w -d.sub.o)9.81 (1) in which: L 1 is the height of the tapping 11 with respect to the highest level of the sea (expressed in m); L R is the length of the overflow column 10 (expressed in m); P 1 is the pressure inside the torch foot tank 6 (expressed in P a ); P atm is the atmospheric pressure (in P a ); d o is the voluminal mass of the liquid (in Kg/m 3 at T 1 °; d w is the voluminal mass of the sea water (kg/m 3 at T 2 °). The most unfavorable conditions being reached when P 1 =P atm (the case of stopping after choking up and total filling with liquid of the overflow column 10 over the length L R ), the relationship (1) may be simplified to: L.sub.1 ×d.sub.o ≧(L.sub.R -L.sub.1)(d.sub.w -d.sub.o) (2) Applications (1) For d w =1020 d o =700 (imperfectly degasified oil) L R =50 m the minimum height L 1 is 15.7 m (example 1) (2) Under the same conditions as above but with a better degasified oil of d o =800, the height L 1 becomes 10.8 m (example 2). (3) Under the same conditions as in example 1 but with a shorter overflow column 10, L R =40 m, the minimum height L 1 is 12.5 m (example 3). (4) Under the same conditions as in example 3 but with an oil density d o =800, the minimum height L 1 becomes=8.62 m (example 4). (B) To prevent gas leaving through the lower end of the overflow column 10, the following relationship should be confirmed: 9.81(L.sub.R -L.sub.2)d.sub.w +P.sub.atm ≧P.sub.1 (3) In which L 2 is the height of the tapping with respect to the lowest level of the sea (expressed in m). Applications (1) with d x =1020 L R =50 m L 2 =30 m P atm =1.013×10 5 P a the pressure P 1 should be less than 3.013×10 5 P a . (2) with d x =1020 L R =40 m L 2 =30 m P atm =1.013×10 5 P a the pressure P 1 should be less than 2.013×10 5 P a . It follows, from an examination of the preceding relationships 1 and 3, that the safety system prposed will not be applicable in all cases, and in particular in water depths which are too shallow. If, for a given set-up, the relationships 1 and 3 are confirmed with reasonable safety coefficients, and if the dimensioning of the ducts is correct to take into account the different pressure drops, the risk of the torch being choked up is very unlikely. However, the risk of liquid being carried to the nose-piece of torch 5 remains, except if the torch foot tank 6 is designed and sized as a gas-liquid (two phase) separator in one possible embodiment, operating at a very low level. This leads to the use of a tank 6 whose dimensions and weight risk being prohibitive. Moreover, since the oil/gas separation takes place without real control, in the torch foot tank 6 where the internals are practically excluded, the risk of carrying along droplets of liquid remains high. An examination of relationships 1 and 3 shows that the increase in dimensions L 1 and L R leads to an improvement in safety. Pollution Should choking up occur, whether the installation comprises this safety system or not, the amount of liquids discharged into the sea will be substantially the same. Nevertheless, for choking up of limited duration, the volume of liquid "trapped" in the overflow column may be raised in the installations and discharged. However, the danger of inopportune ignition of liquid hydrocarbons is considerably less than when directly discharged in the sea. In FIG. 1, the liquids are discharged into the sea "like a spring", that is to say that it will need a considerable hot point in the zone where the liquid hydrocarbons will reach the surface of the sea to cause ignition thereof. However, taking into consideratioon the sea currents which may exist on a good number of sites, the liquid hydrocarbons will only come to the surface at a remote distance from the installations. By way of example, for an overflow column 10 discharging at 50 m below the mean level of the water and with oil of voluminal mass 850, this oil will only come to the surface at about 60 m from the vertical of column 10 for a current of 0.25 knot. Effect of the waves The level of the water inside the overflow column 10 will follow with a delay and damping the level of the water on the outside. However, this point should be confirmed so as to avoid air intakes into the torch barrel 13, especially in the case of short overflow columns 10 and small gas flows. As a general rule, the longer the overflow column 10, the less will be the effect of the waves. To take into account the points mentioned above, an arrangement (FIG. 2) is developed as follows: The torch foot tank 6, generally placed at a low point of the installation, during normal service is used to remove accumulated liquid (circuits 7,8). Its dimensions and its weight become acceptable again. It is completed by a liquid/gas separator 15 placed at the lower part of the torch barrel 13, this latter only being useful should choking up occur. This separator 15 may be housed in the tower 16 supporting the torch. It operates at a very low level and at low pressure. From a certain depth, the overflow column 10 may possibly be expanded to form an additional retention volume 17, thus avoiding any pollution for a limited period of time. The liquid hydrocarbons thus trapped may be subsequently reinserted into the installations by means 13. The lower part of column 10 may be fitted with lateral strainers so as to better disperse the liquid hydrocarbons into the sea. Finally, for some applications, the embodiment shown in FIG. 3 presents a simplified solution. The vertical torch barrel 20 is formed by a tube of variable section or not, being possibly for some applications self-resistant to external forces, and having a diameter such that the rise speed of the gas is sufficiently low for the gas/liquid separation to take place. The speeding up of the gas may be provided if necessary at the torch nose-piece 5 by passing through a reduced tubular section 21 or by any other means. The lower end 22 of the torch barrel serves as torch foot tank under normal operating conditions, and is equipped with an overflow column 10 such as those previously described as well as a droplet take-up circuit 7, 8 and 13'. An additional simplification will consist for some applications in constructing the overflow column-torch barrel assembly as a continuous tubing with possibly variable section, the droplet take-up circuit being then installed at a suitable height on the continuous tubing. Furthermore, in all the installation configurations of this safety system, this latter may use, for its construction, already existing tube parts, made from steel or other materials such as concrete, and able to fulfil other functions such as supporting the installations. The support thereof may also be provided by means of frames or supports required or not for fulfilling other functions.

A safety system for eliminating the risk of liquids, rather than gases, being carried to a torch nose-piece or to a vent hole, during burning or dispersion of the gases associated with the production or treatment of hydrocarbons, particularly on off-shore installations. The gas flow line is connected to a storage volume or capacity, such as a torch foot tank. An overflow column is also connected to the gas flow line, and discharges below a liquid level, such as for example the sea, at a distance from the connection to the overflow column.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Continuation Application of U.S. Ser. No. 09/412,042, filed Oct. 04, 1999 (Attorney Docket No. EXPO0001). BACKGROUND OF THE INVENTION [0002] 1. Technical Field [0003] The present invention relates to business models for managing foreign and domestic accounts receivable, and more specifically to client/server multi-user trade finance systems that assist manufacturers, traders and exporters in providing key trade finance information to financial institutions, credit insurance underwriters, insurance brokers and entities involved in the securitization of trade receivables. [0004] 2. Description of the Prior Art [0005] The international markets for United States manufacturers, traders, and exporters have grown tremendously in recent years, and this growth has principally been fueled by new technology. Such growth has also included the development of new and varied distribution channels. All of this has placed a great strain on existing finance methods and departments to deal with accounts-receivable problems. Foreign and domestic buyers insist that manufacturers, traders and exporters sell products to them on open account receivables terms. Original equipment manufacturers (OEM's), distributors, and resellers are also seeking extended payment terms to allow themselves enough time to install and collect from the end user before having to pay the manufacturer. [0006] New systems are needed that can reduce the credit exposure to foreign and domestic buyers, accelerate cash flow, improve and manage balance sheet efficiency ratios, etc. Requests for extended payment terms need to be accommodated, while avoiding high credit exposure, increased days sales, outstanding (DSO) and the offering of excessive cash discounts to accelerate collections. Such improved systems would be used to facilitate revenue recognition, and provide an overall increase in the return-on-capital. [0007] Credit insurance can be used as a source of repayment for the purchase/financing of accounts receivable. But such requires that accurate and timely information be provided by manufacturers, traders, and exporters that includes routine periodic reports and useful historical data. Management systems need to properly track and control large numbers of insured open accounts receivable. It would be beneficial if the manufacturers, traders, and exporters had systems that would allow them to function as the financial institutions' collection agent. Such necessitates the ability to properly monitor, segregate, and quickly remit collected funds. Seeing how much of the committed insurance/credit limit capacity has been used according to policy, country, buyer, and other parameters established by the credit insurer and/or financial institution can also facilitate financing and claims processing. SUMMARY OF THE INVENTION [0008] A trade finance automation system includes an accounts receivable database receiving and storing invoices issued by one or more prescribed vendors for sales made to specified buyers. A credit limits database contains various credit limits applicable to buyers invoices that are subject to existing third party financing, the credit limits dictated by factors including terms of said third party financing. A credit limits tester performs substantially real time checking of buyers invoices in the accounts receivable database to ensure compliance with the credit limits set forth in the credit limits database for said buyers. BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1 is a flowchart for a system embodiment of the present invention that includes an integrated software program used to monitor and track all aspects of the short-term export and domestic open accounts receivable process according to the invention; [0010] FIG. 2 is a flow diagram representing an accounts receivable finance system according to the invention that can be operated by computer on the Internet server utilized by the service provider of FIG. 1 ; [0011] FIG. 3 is a block diagram of a centralized Internet server topology according to the invention for the system of FIG. 2 ; [0012] FIG. 4 is a block diagram of a single-user topology according to the invention for the system of FIG. 2 ; [0013] FIG. 5 is a block diagram of a multi-user topology according to the invention for the system of FIG. 2 ; and [0014] FIG. 6 is a block diagram of a high-availability central server topology that can be used for the system of FIG. 2 . DETAILED DESCRIPTION OF THE INVENTION [0015] FIG. 1 is a flowchart for a system embodiment of the present invention that includes an integrated software program used to monitor and track all aspects of the short-term export and domestic open accounts receivable process, and is referred to herein by the general reference numeral 100 . System 100 provides for tracking of shipments, invoices, payments and remittances. It monitors manufacturer credit, buyer limits, country limits and other insurance policy/financing terms. It can determine the eligibility of receivables for financing or purchase by financial institutions. System 100 enforces realtime compliance with predetermined credit limits, insurance policies, financial institutions' financing agreements, and it can generate a variety of reports specific to the needs of manufacturers/traders/exporters, credit insurers/brokers, and financial institutions. [0016] System 100 is organized around an Internet server that is operated by a service provider 102 , e.g., Export Finance Systems, Inc. (San Francisco, Calif.). A bank 104 or other financial institution introduces the service provider 102 , who operates the Internet server, to a manufacturer/trader/exporter 106 . Such introduction may alternatively be made by an insurance broker 108 or an insurance underwriter 110 . The manufacturer/trader/exporter 106 is characterized by its generation of accounts receivables to foreign or domestic customers 112 that require some form of receivables financing or credit insurance on some or all of its trade accounts. The financial institution 104 , insurance broker 108 , and insurance underwriter 110 are in the business of arranging and/or providing such receivables financing or credit insurance. Each of the business operations shown in FIG. 1 is typically independent of the other and are physically remote. The Internet is used as a communications tool to make the physical separation distances between them of no consequence. [0017] In operation, the underwriter 110 and broker 108 determine the eligibility of the foreign or domestic customers 112 for a credit insurance policy. A commitment to the manufacturer/trader/exporter 106 is obtained from the underwriter 110 and a financing commitment is obtained from the financial institution 104 . The commitment letter from the financial institution issued to the manufacturer/trader/exporter 106 agrees to purchase a specified amount of accounts receivable of approved buyers 112 both insured and uninsured. All such commitments are recorded at the Internet server 102 . The manufacturer/trader/exporter 106 thereafter ships products or services to the buyers 112 . The invoices are generated and collections activities of the manufacturer/trader/exporter 106 are done with computer programs that are run and maintained by the manufacturer/exporter on its own enterprise system. The invoice and collection data generated by the manufacturer/trader/exporter 106 is either manually or electronically inputted into the Internet server 102 . Electronic input presently involves the inputting of data provided in various formats, sorting of such data, and processing of such data, such that the data are available to the system in a system format. In other embodiments of the invention, the data may be extracted directly from their source. [0018] The system screens and flags which accounts receivable qualify for particular commitment letters and insurance policies. The manufacturer/trader/exporter 106 sells/finances the insured accounts receivable to the financial institution or bank 104 . Each such account receivable selected for financing draws down the credit limit reserve maintained for each insurance policy, policy category or financial institution established credit limit. Each collection is used in realtime to free up the credit insurance or financial institution credit limit it corresponds to. [0019] Hundreds, if not thousands of independent financial institutions 104 , manufacturers/exporters 106 , insurance brokers 108 , insurance underwriters 110 , and buyers 112 can be simultaneously serviced by a single Internet server 102 or cluster of servers 102 . A per-use or subscription fee is charged by the Internet service provider 102 to one or more of the other participants. [0020] The manufacturer/trader/exporter 106 logs onto the Internet server 102 to update and monitor status of all insured/eligible receivables, as well as specific receivables sold/financed with financial institutions. Reports can be generated on the Internet server 102 by all relevant parties. Each buyer 112 pays off the accounts receivable to the manufacturer/trader/exporter 106 acting as collection agent for the purchaser/financier of the accounts receivables. The manufacturer/trader/exporter 106 remits funds to financial institution 104 . [0021] Some or many of the functions provided by the Internet server 102 can be distributed out to the manufacturers/traders/exporters 106 . The centralized system configuration is preferred in which each of the financial institutions 104 , manufacturers/traders/exporters 106 , insurance brokers 108 , insurance underwriters 110 , and buyers 112 use Internet browsers connected through their own Internet service providers (ISPs). [0022] In the distributed system configuration, system 100 is a Microsoft WINDOWS-based PC multi-user trade finance system operating at the manufacturers'/traders'/exporters' site to provide the same key trade finance information to manufacturers/traders/exporters, financial institutions, credit insurance underwriters and insurance brokers. The system 100 in the distributed environment provides for users to perform work on their own computer systems and periodically update a central system through an Internet connection. This topology requires that a system user have a computer with access to the Internet. [0023] Credit insurance policies vary depending on the insurance underwriter as well as the specific types and kinds of coverage required. However, there are general policy parameters that are common throughout all policies. The insurance policy is used to indemnify the insured for the insured percentage of the amount of a loss that is in excess of any applicable deductible arising from the failure of the buyer to pay the contract price of an insured transaction. The purpose of an accounts receivable tracking system is to test all the relevant parameters of each invoice to determine if that invoice is insured or uninsured or meets the buyer and credit requirements established by a financial institution. Each transaction is tested to see if it meets each of several different guidelines. For example, a buyer-limit test can check the total amount payable for all losses for a specified buyer. A country-limit test can check the total amount payable for all losses on all buyers in a specified country. A policy-limit test can check the specified dollar amount that represents the aggregate limit of liability of the insurance company. A ship-date test can check to assure the actual shipping date for the goods falls within the policy or financing agreement effective and expiration dates. A payment-terms test can check the maximum permitted number of open account days from the date of the invoice. A past-due test can check if the past due date or amount is exceeded. If so, subsequent invoices cannot be insured and/or financed. [0024] FIG. 2 represents an accounts receivable finance system 200 that can be operated by computer on the Internet server 102 ( FIG. 1 ). The accounts receivable finance system 200 begins with new shipment information provided by a manufacturer or exporter. Such information is typically entered with a personal computer and a browser logged on though the Internet to the Internet server 102 ( FIG. 1 ). A utility 202 allows the specific invoice data about the sale and shipment to be entered. Such information can be used in a utility 204 to update information in an exporter and buyer database 206 . If the buyer information and elements of the shipment are already known, the exporter and buyer database 206 is used to add information to the invoice, e.g., fill in the blank boxes. A test of the credit limits associated with the particular buyer is done in a utility 208 . A credit limits database 210 is used as a template. Such credit limits database 210 is built up from information included in the credit insurance underwriter's policy and the financial institution's commitment letter to provide credit to the manufacturer or exporter. A filter 212 is used by the manufacturer or exporter to select particular invoices for sale or financing from all those that seem to qualify. All invoices, selected or not, qualified for credit insurance or not, are stored in an accounts receivable database 214 . As payments, collections, and credits come in over time, a utility 216 is used to update the corresponding accounts receivable in the database 214 . Payments and credits are utilized by utility 216 so that the credit limits database 210 can be updated to immediately give back the credit reserve for use on new invoices. A user's accounting system 217 can be connected to the accounts receivable database so that invoice and payment information can be imported electronically into the accounts receivable database 214 . A reports generator 218 is used to provide periodic summaries, and various reports to each interested party. [0025] The exporter and buyer database 206 capture basic data about the exporter, e.g., general company information, company financial history, export sales experience and bank information. It also includes information about all of the exporter's major buyers. Such information includes general company information, sales experience, trade references, financial and credit information, etc. Once an insurance policy and/or financing agreement has been issued, the credit limits database 210 is used to store all of the relevant policy/financial institution information including general policy/financing agreement terms and limits, detailed manufacturer/trader/exporter limits, specific buyer limits, discretionary credit limits, special buyer credit limits, approved payment terms by buyer and country limits, etc. As shipments are made, the accounts receivable database 214 is updated to reflect invoice amount, shipment date, purchase order number, bill of lading information, invoice number, term and invoice date. As the required data of a shipment or invoice is entered into the system, the data is checked, monitored and tested to insure that all invoices meet the overall policy and financial institution terms and limits. Invoice totals are checked against the current outstanding balance and limit for each individual buyer. The entering of shipments or invoices captures information that is needed for the preparation of premium reports. The reports utility 218 preferably provides premium reporting, accounts receivable aging, past due invoices, activity reports, status of sold invoices, exporter credit limit, buyer credit limits, country credit limits, remittance reports, etc. [0026] The payments and credits utility 216 is used to enter payments from buyers and other credit adjustments to their accounts. As new payments are entered, the system updates all of the related limits for both the manufacturer/trader/exporter and buyer so insurance capacity or credit limits are freed-up. Such capacity is made available to subsequent invoices on a first-in, first-out basis. This allows an invoice to now become insured/eligible which was previously uninsured/ineligible because the total outstanding to a particular buyer exceeded its limit. [0027] Historical or realtime data for invoice and payment records can be entered manually or large amounts of data can be imported from a user's accounting software or mainframe 217 all at one time with an import utility function, e.g., to save time and reduce the possibility of errors. The selection of eligible invoices for sale or financing in utility filter 212 is used to select, flag and track those invoices that are eligible for sale or financing. Any of several filters enable the user to select only those invoices that meet certain criteria. The payments and credits utility 216 is used to record and track when collections on sold invoices are to be remitted to the financial institution. This capability assists in calculating the amount of interest earned by the purchaser/financier of the receivables and any possible rebate of interest due to the seller of the invoices. [0028] The Internet provides an unprecedented level of accessibility and connectivity between users, thereby allowing users to keep their data up-to-date using the most efficient connection available, regardless of their current location. [0029] The trade finance system can also be installed directly on a user's desktop computer or network. This distributed-type system is very responsive since the application resides on either the user's desktop computer or network, and the central data files can be replicated periodically via the Internet. Because system 200 can be run on the user's network, access to reports and other information in the system 200 is available to anyone with appropriate password authority at the client location. System 200 preferably provides for the electronic bulk import of data from the user's internal accounting system, which avoids time-consuming data reentry. Security can be provided through the use of password codes, data encryption and other security measures. The application used at client site can preferably be updated from a remote location. [0030] User Interface [0031] The control of each utility and database illustrated in FIG. 2 is preferably done through an associated graphical user interface (GUI), e.g., a browser display screen or window. An exporter and buyer information display screen preferably includes general and historical data about the exporter, the buyer parent and each of the buyers. Such screens are displayed from the administration section of a welcome screen, or main menu. The user typically enters this information once and updates it on a periodic basis, as needed. [0032] A credits limits display screen includes critical data that forms the functional basis of system 200 , so this data should only be entered or updated by personnel who understand the underlying concepts of the insurance policy/financing agreement and how it relates to each buyer. The edit functionality for these screens is preferably accessible at the highest manufacturer/trader/exporter security level only or directly inputted by the insurance underwriter, insurance broker, or financial institution via the Internet. Any original data or changes to the data entered into this display screen are supported by confirmation from the insurance underwriter and/or the financial institution. [0033] The policy screen includes the basic policy/credit limit information such as policy number and insurer name. In addition, all the critical information regarding the policy/credit limits and the outstanding invoice totals are displayed here. The country limits screen includes the credit limit information for each country and the dollar amount of outstanding invoices. The buyer limits screen includes the credit limit information for each buyer entered into system 200 and the dollar amount of each buyer's outstanding invoices. This display screen preferably describes how to access the screens and enter, edit and delete policy, country and buyer limits information. Definitions for each field relating to insurance information are provided. All the information for this display screen is preferably found in the insurance policy. [0034] The invoices display screens are preferably used to manually enter and edit shipment and invoice data for each insured buyer. The entry and edit functionality for these screens is preferably accessible at the operator security level. [0035] The import menu provides functionality for importing large data files including the shipment and invoice information. This screen is preferably also accessible at the operator security level. [0036] As invoices are entered into system 200 , each key field is preferably tested against the appropriate parameters and limits of the insurance policy/financing agreement. [0037] System 200 continually tests the limits as new invoices and payments are entered. An invoice that was uninsured/ineligible due to an over-limit situation can become insured/eligible at a later date as that condition is preferably eliminated. [0038] This invoices display screen covers two screens: invoice entry and invoice editing. The import menu screens cover: new import, history and edit invoices. [0039] The invoice entry screen is preferably a basic data entry screen for entering invoices manually. Once the data is preferably saved it automatically displays on the right half of the screen. This display allows users to keep track of the last invoice entered when inputting large quantities of invoice data. [0040] The invoice editing screen allows users to make changes to saved invoice data. In addition, it displays invoice-related information regarding coverage test failures, customer payments and bank remittances. [0041] A new import screen is preferably used for the setup screen for importing data files into system 200 . A history screen allows the tracking of which files have been imported into system 200 . The edit screens provide a way to review and correct any invoice or payment records that may have been rejected in the import process. This display screen preferably describes how to access these screens to manually enter, edit and delete shipment and invoice information and use the bulk import process. Although most fields are self-explanatory, descriptions and help screens are provided for most of the fields. The tab key is used to move through the fields. The text in blue are view-only fields. [0042] The payment entry screen is preferably a data entry screen to enter cash receipts and adjustments to specific invoices that have been previously entered on the invoice entry screen. For example, credit memos, write-offs, discounts taken, etc. The entry and edit functionality for these screens is preferably accessible at the operator security level. Once the data is preferably saved or imported it automatically displays on the right half of the screen. This display allows users to keep track of the last invoice entered when inputting large quantities of invoice data. [0043] A bulk import screen for payments preferably operates identically to the process for bulk invoices. An import edit screen for payments also provides the functionality for viewing and correcting errors in imported files. [0044] A financing-sell invoices display screen is preferably used to select eligible invoices in system 200 for sale or financing and flag the invoices that have actually been sold. The functionality for this screen is preferably accessible at the supervisor security level only. [0045] In one embodiment of the present invention, the system 200 selects for sale only insured/eligible invoices for all buyers. Partially insured/eligible or uninsured/ineligible invoices are not eligible for sale. When the date and amount criteria are entered in the designated fields, the corresponding invoices display with all their related information. Invoices can be reviewed and selected individually or a short cut key allows users to select all invoices at one time. This display screen preferably describes how to access the screen and select the invoices to sell or finance and create a report for the selected invoices. It also preferably describes how to edit the annual interest rate and sold date for batches of selected invoices. [0046] A financing-remittance display screen is preferably used to enter remittances made to the financial institution that bought a selected invoice. An employee with an operator security level may enter remittances. The remittance entry screen is preferably a basic data entry screen for individual remittances. Once the data is preferably saved it automatically displays on the right half of the screen. This display allows users to keep track of the last invoice entered when inputting large quantities of invoice data. The bulk remittance screen provides a way to enter a remittance for quantities of sold invoices at one time. When the date and amount criteria are entered in the designated fields the corresponding invoices display with all their related information. Invoices can be reviewed and selected individually or a short cut key allows users to select all invoices at one time. This display screen preferably describes how to access each screen and select the invoices to remit to the financial institution. It also preferably describes how to edit the remit date for batches of selected invoices. [0047] Reports [0048] A reports display screen is preferably used to provide a wide-range of integrated and useful reports. The use of a relational database allows a series of queries to design reports providing invoice, credit limits and policy data. A display screen can be used to provide a brief description of each report. A list of preferred report types follows. [0049] An invoice aging report uses an as of date to select and print a detail aged trial balance of all open accounts receivable. Invoices can be aged by due date or invoice date and aging can be selected on the following criteria: all outstanding invoices, all insured invoices or all sold invoices. Such report can also be selected by individual buyer or all buyers and can list in detail by buyer and exporter total and individual financial institutions or all financial institutions. [0050] An invoice past due report shows all of the invoices in detail that are past due based on the past due date that is preferably calculated for each invoice in system 200 . By specifying the date from which past dues are to be calculated, dollar amount threshold and the number of days past due, system 200 reports each past due invoice by buyer and the insured in total. This report is preferably used by the insurance underwriter, insurance broker and by the financial institution as well as by the insured. [0051] An invoice activity report lists either in summary or in detail, by buyer, all of the new invoices entered and all cash receipts and credits applied between a specified beginning date and ending date. This report is preferably particularly useful in reconciling changes in account balances between periods. [0052] An invoices sold report selects and prints a summary or in detail the current status of all invoices that have been sold on a specified date. An individual financial institution or all financial institutions can also be designated. [0053] A remittance history report selects and prints a summary of all remittances for corresponding invoices that have been made on a specified date. An individual financial institution or all financial institutions can also be designated. [0054] A remittance-detail report displays the amounts outstanding, the length of time outstanding, payments made and interest or discount earned for each sold invoice. Individual financial institutions or all financial institutions can also be designated. [0055] A borrowing base report displays eligible outstanding accounts receivable that can be used as a borrowing base for a financial institution loan. No disputed or previously sold invoices are included, unless they have been bought back. [0056] An exporter credit limits report can be selected by policy number and displays the current outstanding totals for all buyers covered under the insurance policy key, e.g., total invoices outstanding, total insured invoices outstanding, total uninsured invoices outstanding, total sold invoices outstanding, total uninsured invoices outstanding per books, and total sold invoices outstanding per financial institution. [0057] A country credit limits report shows the outstanding balances of invoices by country and by buyer within each country. These amounts are relevant because in some cases the insurance policy/financing agreement places limits on a country by country basis. [0058] A buyer credit limits report displays the current outstanding total for each individual buyer covered under the insurance policy and/or financing agreement and displays, e.g., approved buyer limit, limit expiration date, total invoices outstanding, total insured invoices outstanding, high credit, unused credit, uninsured invoices outstanding, sold invoices outstanding per books and sold invoices outstanding per financial institution. [0059] A policy premium report calculates the insurance premium earned based on the premium rate defined under the insurance policy and lists in either summary or invoice detail. Such as, all of the shipments entered into system 200 for the time period defined on the premium reports screen, and a dollar value of the shipments. [0060] System Architecture [0061] FIG. 3 represents an Internet topology 300 for system 200 ( FIG. 2 ). A user's PC 302 communicates with a centralized server 304 over an Internet connection 306 . The centralized server 304 is implemented with either UNIX or WINDOWS-NT running Web server software. The Internet server 304 contains three layers of services: a) client interaction management, b) business rules, and c) datastore services. A database engine functions as both a data store and to process transactions. Such database engine is preferred because it can easily be scaled from a single-user stand-alone system to a large scale clustered multiprocessor topology. Business rules can be implemented both in the database engine and as independent objects. A Web server provides client authentication and application launch services. These allow new versions of an interface program to be automatically downloaded from the centralized server 304 over an Internet connection 306 . [0062] A second main component is the client interface. The client interface uses a combination of HTML, browser-resident programs using ActiveX, Active Document, Java, or similar technical platforms and stand-alone utilities. The same code base will work with either the databases on a central server ( FIG. 3 ) or on a stand-alone PC ( FIG. 4 ). [0063] FIG. 4 shows a single-user topology 400 for system 200 which allows clients to manage their data on-site and not on a central server. A database engine is installed on a user's PC 402 . A central server 404 can be used as a data repository. Client data can be uploaded to the central server 404 via Internet connection 406 and thereafter passed to financial institutions, insurance underwriters and insurance brokers. A local backup 408 is included. [0064] FIG. 5 represents a multi-user topology 500 for system 200 . A user's PC 502 communicates with a client database engine 504 over a local area network (LAN) or wide area network (WAN) connection 506 . A centralized server 508 can be used as a data repository and uses an Internet connection 510 that communicates over port- 1433 , for example. A local backup 512 is included. The client database engine 504 includes procedures and a private data repository. [0065] FIG. 6 represents a high-availability central server topology 600 that can be used for system 200 . At a primary Web location 602 , e.g., San Francisco, is connected to a fall-back secondary location 604 via a point-to-point high speed connections 606 and 607 . Data synchronization is constantly provided over such high speed connections 606 and 607 . A web-site availability monitor 608 allows the adjustment of routing tables 610 associated with a primary logon web-site presence 612 . A web-server 614 responds to client logons and directs traffic and interactions with one of several primary client servers 616 - 618 physically located nearby. A fall-back logon web-site presence 620 is physically associated with several fallback severs 621 - 623 . The point-to-point high speed connection 606 allows the primary logon web-site presence 612 to directly access the fallback severs 621 - 623 . The point-to-point high speed connection 607 allows the fallback logon web-site presence 620 to directly access the primary client severs 616 - 618 . A fallback web-site availability monitor 628 allows the adjustment of routing tables 626 associated with the fallback logon web-site presence 620 . A development and test center 630 includes a webserver and database engine. As any server 616 - 618 becomes unavailable, clients are automatically redirected to a matching backup server 621 - 623 . [0066] Although the invention is preferably described herein with reference to the preferred embodiment, one skilled in the art will readily appreciate that other architectures may be substituted for those set forth herein without departing from the spirit and scope of the present invention. Accordingly, the invention should only be limited by the Claims included below.

A trade finance automation system includes an accounts receivable database receiving and storing invoices issued by one or more prescribed vendors for sales made to specified buyers. A credit limits database contains various credit limits applicable to buyers invoices that are subject to existing third party financing, the credit limits dictated by factors including terms of said third party financing. A credit limits tester performs substantially real time checking of buyers invoices in the accounts receivable database to ensure compliance with the credit limits set forth in the credit limits database for said buyers.

CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation of co-pending International Application No. PCT/EP98/00791, filed Feb. 12, 1998. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic ballast for operating at least one gas discharge lamp wherein the gas discharge lamp is supplied with an alternating voltage and wherein the lamp filaments are preheated. 2. Description of the Related Art Such a ballast is known from EP-A1-0 490 329. As in the case of other lamps as well, in the case of gas discharge lamps on account of the phenomena of wear of the heater filaments at the end of the life of the gas discharge lamp the effect that occurs is one where the lamp electrodes wear unevenly over time, that is, the erosion of the emitting layers on the lamp electrodes is different. On account of the differing wear of the lamp electrodes, differences result in the emitting power of the two lamp electrodes. FIG. 5 shows the consequences of this effect with reference to the current i L that is fed to the gas discharge lamp. It can be seen from FIG. 5 that a higher current flows in the one direction than in the other so that the time characteristic i L (t) has an excess of one half-wave (in FIG. 5 the positive half-wave) . As a result of the different erosion of the two lamp electrodes, asymmetries thus result that not only give rise to comparatively great light-flickering at the end of the life of the gas discharge lamp, but even in the extreme case also only permit operation of the gas discharge lamp during one half-wave (in FIG. 5 during the positive half-wave). In this case, the gas discharge lamp acts as a rectifier so that the previously described effect is termed a "rectification effect". The work function for the electrons is higher at that electrode which has worn away to a greater extent in the course of time than at the other electrode which has worn away to a lesser extent. The minimum energy required to draw an electron out of a metal, in the present case out of the lamp electrode, is generally termed the work function. The dipole layer at the surface of the metal, that is, the lamp electrode, is then an important factor in determining the work function. The electrode that has worn away to a greater extent and which has a higher work function for the electrons than the electrode which has worn away to a lesser extent consequently heats up to a greater extent when the gas discharge lamp is put into operation than the opposing electrode. The increase in temperature in the electrode can be so great, in particular in the case of lamps with a small diameter, that portions of the glass lamp bulb can melt. In order to avoid the risk of an accident resulting from the increase in temperature of the glass lamp bulb, consequently it is necessary to identify the rectification effect and, if applicable, switch off the gas discharge lamp or reduce its power input, in which case there are already mandatory standards for monitoring the previously described uneven emission of the lamp electrodes. As has already been mentioned above, the rectification effect manifests itself in asymmetry of the lamp current i L flowing by way of the gas discharge path of the lamp. one possibility for identifying the rectification effect is therefore to monitor the lamp current flowing by way of the gas discharge path of the lamp, in which case with this method it is certainly possible to identify differences in emission of the lamp electrodes directly, but the evaluation of these emission differences and also the translation of this identification process into a monitoring circuit arrangement that is designed as an integrated circuit, in particular as an application specific circuit (ASIC), are problematic. As an alternative to this, it is also possible to identify the rectification effect by monitoring the lamp voltage, since the asymmetries occurring in the lamp current are transferred to the lamp voltage. If, for example, the monitored lamp voltage exceeds a specific limiting value in one direction as a consequence of the asymmetrical emission of the lamp electrodes, the gas discharge lamp is switched off. In the case of this identification process, however, it is disadvantageous that the sensitivity of this method is limited, since in the case of a fault, that is, if the rectification effect occurs, the peak value of the lamp voltage that is detected is merely 60% higher than its value in the normal operating case. Moreover, even when the gas discharge lamp is dimmed, the lamp voltage is changed so that on account of the dimming of the gas discharge lamp and on account of the lamp voltage that rises in a corresponding manner as a result, it may possibly be concluded by mistake that the rectification effect is present in the gas discharge lamp. Furthermore, it would be desirable to use the changing arithmetical mean value of the monitored circuit variable for the detection of the rectification effect. This is not a possibility, however, when monitoring the lamp voltage, since--as already described--in the case of a fault the peak value of the lamp voltage is merely increased by 60% so that the increase in the mean value of the lamp voltage is not sufficient to detect the rectification effect in a sufficiently precise manner. All in all, therefore, the detection of the rectification effect by monitoring the lamp voltage is problematic. In the case of the electronic ballast known from EP-A1-0 490 329 belonging to the applicant, a first resistor is connected in series with the primary winding of the filament-heating transformer. The current flowing through the primary winding and the first resistor generates a voltage at the resistor, which voltage is proportional to the current flowing through the heater filaments of the lamp. The voltage drop across the first resistor is evaluated by a control and regulating circuit arrangement in order to detect overvoltage or undervoltage. Identification of a rectification effect is not, however, described in this publication. Identification of a rectification effect is, however, described in U.S. Pat. No. 5,023,516. For this purpose, a monitoring circuit arrangement is provided that comprises a series circuit arrangement consisting of two resistors and an inductor, with the series circuit arrangement being connected in parallel with a gas discharge lamp that is to be monitored. A thyristor, which is coupled to the inverter of the ballast, acts at the interconnection point between the one resistor and the inductor and thus evaluates the voltage dropping across the one resistor for the purpose of identifying the rectification effect. As soon as the voltage, which drops across the one resistor and which is proportional to the current flowing by way of the one resistor, has reached a specific limiting value, the thyristor is activated and consequently the inverter is switched off. The known monitoring circuit arrangement, however, only detects the presence of a rectification effect in one direction of polarity of the voltage dropping across the resistor. SUMMARY OF THE INVENTION The underlying object of the invention is to provide the known electronic ballast with a monitoring circuit arrangement with which the rectification effect can be detected in a more precise manner. This object is achieved in accordance with the invention by means of an electronic ballast for operating at least one gas discharge lamp. The ballast includes an inverter having a load circuit which is connected to the inverter and to which a gas discharge lamp can be connected. The electronic ballast also includes a filament-heating transformer for preheating the lamp filaments of the gas discharge lamp. The primary winding of the transformer is connected in series with a first resistor in parallel with the gas discharge lamp. A monitoring circuit arrangement is provided for monitoring current flowing by way of the primary winding of the filament-heating transformer or a variable that is proportionally dependent upon such current. The interconnection point between the primary winding of the filament-heating transformer and the first resistor is connected to the monitoring circuit arrangement by way of a second resistor so that the voltage drop across the first resistor and the current which flows by way of the second resistor are fed as monitoring variables to the monitoring circuit arrangement. The monitoring circuit arrangement assesses, as a monitoring variable, the presence of the rectification effect in the gas discharge lamp in the case of a voltage drop across the first resistor which increases in a positive direction or a current flowing through the first resistor which increases in a positive direction as a function of the voltage drop across the first resistor, in that the monitoring circuit arrangement assesses, as a monitoring variable, the presence of the rectification effect in the gas discharge lamp in the case of a voltage drop across the first resistor which increases in a negative direction or a current flow through the first resistor which increases in a negative direction as a function of the current flow through the second resistor, and in that the monitoring circuit arrangement is constructed to respond to the presence of a rectification effect in the gas discharge lamp upon the monitoring variable exceeding a predetermined limiting value. The solution in accordance with the invention thus guarantees that the rectification effect is detected in both directions of polarization of the voltage dropping across the first resistor and as a result with a high level of sensitivity. The circuit arrangement in accordance with the present invention can be extended in a simple manner in that devices with two or more flames can be reliably monitored for the occurrence of a rectification effect in one of the gas discharge lamps. The filament or heating current or the variable that is proportional to the heating current flowing by way of the primary winding of the filament-heating transformer is monitored in particular with the aid of a monitoring circuit arrangement which is of such a kind that, after identification of the rectification effect, it activates the inverter supplying the gas discharge lamp with an alternating voltage in order to change the frequency and/or the pulse duty factor of the alternating voltage delivered by the inverter and thus to reduce the power consumed by the gas discharge lamp. In this way, the glass bulb of the gas discharge lamp is reliably prevented from melting after the occurrence of the rectification effect. Other advantageous and novel features of the invention are described and claimed herein. BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in greater detail in the following with the aid of preferred exemplary embodiments and with reference to the enclosed drawing, in which: FIG. 1 shows a first exemplary embodiment of the electronic ballast in accordance with the invention for operating a gas discharge lamp; FIG. 2 shows voltage and current characteristics in the case of a heating current that increases in a positive direction in the circuit arrangement that is shown in FIG. 1; FIG. 3 shows voltage and current characteristics in the case of a heating current that increases in a negative direction in the circuit arrangement that is shown in FIG. 1; FIG. 4 shows a second exemplary embodiment of the electronic ballast in accordance with the invention; and FIG. 5 shows the characteristic of the lamp current over the gas discharge path of a gas discharge lamp when the rectification effect occurs. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first exemplary embodiment of the electronic ballast in accordance with the invention for operating a gas discharge lamp, wherein the inductor which is monitored and connected in parallel with the gas discharge lamp is formed by the primary winding of a filament-heating transformer. The solution in accordance with the invention generally consists in evaluating the current flowing by way of an inductor connected in parallel with the gas discharge lamp or a variable that is proportional thereto, since the asymmetries that occur in the lamp branch in the case of a rectification effect are transferred to the current flowing by way of this inductor. The electronic ballast shown in FIG. 1 in the main has a rectifier circuit arrangement 1, an inverter 2, a monitoring circuit arrangement 3 and also a load circuit connected to the inverter 2 which inter alia contains a gas discharge lamp 10 which is to be operated and monitored for the occurrence of the rectification effect. The rectifier 1 is connected to a mains voltage source and converts the mains voltage into a rectified intermediate voltage which is fed to the inverter 2. The inverter 2 as a rule comprises two controllable switches (not shown), for example MOS-field effect transistors, which are alternately activated by means of a corresponding control circuit arrangement so that in each case one of the switches is switched on and the other is switched off. The two inverter switches are connected in a series circuit arrangement between a supply voltage and earth, in which case the load circuit containing the gas discharge lamp 10 is connected to the common junction between the two inverter switches. In addition to the gas discharge lamp 10, the load circuit comprises a series-resonant circuit with a resonant circuit coil 4 and a resonant circuit capacitor 5 which is connected to earth. Connected to the interconnection point between the resonant circuit capacitor 5 and the resonant circuit coil 4 there is a coupling capacitor 6 which is connected to one of the lamp filaments of the gas discharge lamp 10. On account of the fact that the switches of the inverter 2 are activated alternately, the rectified intermediate voltage is converted into a "chopped" high-frequency alternating voltage. This high-frequency alternating voltage is fed to the gas discharge lamp 10 by way of the series-resonant circuit. Before the firing voltage is applied to the gas discharge lamp 10, the lamp electrodes of the gas discharge lamp 10 are preheated in order to extend the life of the gas discharge lamp. A filament-heating transformer having a primary winding 7A and two secondary windings 7B and 7C is provided for the purpose of preheating the gas discharge lamp 10. The primary winding is connected to the series resonant circuit, whilst the secondary windings are, in each case, connected in parallel with one of the lamp filaments. In this way it is possible to supply the lamp filaments with energy in the fired mode of operation as well. During the preheating operation, the frequency of the alternating voltage delivered by the inverter 2 is changed in relation to the resonant frequency of the series-resonant circuit in such a way that the voltage across the resonant-circuit capacitor 5 and thus across the gas discharge lamp 10 does not cause the gas discharge lamp 10 to be fired. In this case, a substantially constant current flows through the lamp electrodes of the gas discharge lamp 10 that are realized as filaments, whereby the lamp filaments are preheated. At the end of the preheating phase, the frequency of the alternating voltage delivered by the inverter 2 is shifted into the proximity of the resonant frequency of the series-resonant circuit, whereby the voltage applied to the resonant-circuit capacitor 5 and the gas discharge lamp 10 is increased so that the gas discharge lamp 10 is fired. In accordance with the invention it is proposed that the primary current i 1 flowing by way of the primary winding 7A of the filament-heating transformer be monitored. To this end, connected in series with the primary winding 7A there is a resistor 9 which is connected to earth. A further resistor 8 leads from the interconnection point between the primary winding 7A and the resistor 9 to the monitoring circuit arrangement 3 which for its part is connected to earth. The function of the electronic ballast in accordance with the invention, as shown in FIG. 1, is described in greater detail in the following with reference to FIG. 2 and FIG. 3. As shown in FIG. 5, when the rectification effect described at the beginning occurs, asymmetries result in the lamp current i L that flows by way of the gas discharge path of the gas discharge lamp 10. As soon as this asymmetrical current i L occurs in the lamp branch, the asymmetries are transferred to the primary current i 1 flowing by way of the primary winding 7A of the filament-heating transformer. In order to be able to detect and evaluate the asymmetries that occur in the primary current i 1 , the primary current i 1 is fed by way of the resistor 9 to the monitoring circuit arrangement 3. In this connection, a distinction is to be made between two different cases, depending on whether the half-waves of the lamp current i L shown in FIG. 5 relate to the positive or negative half-waves. In other words, in accordance with the invention a distinction is made between the rectification effect that occurs in the one direction of the gas discharge lamp 10 and the rectification effect that occurs in the opposite direction. For the case where on account of the rectification effect that occurs in the gas discharge lamp 10 a current i 3 that changes in a positive direction flows by way of the resistor 9, in accordance with the invention the rectification effect is detected by monitoring the voltage u 3 that drops across the resistor 9. FIG. 2a show the time characteristic of the voltage u 3 that drops across the resistor 9 in this case. On account of the different wear of the lamp electrodes that occurs as a result of the ageing of the lamp electrodes, in the course of time, as already described at the beginning, an excess of the positive half-waves in relation to the negative half-waves results in the voltage u 3 that drops across the resistor 9 or in the current i 3 flowing by way of the resistor 9 respectively. In the extreme case, over time the negative half-waves in the voltage and current characteristics of u 3 and i 3 respectively completely disappear so that the gas discharge lamp 10 acts as a rectifier. A threshold value U S can be defined by way of the resistance value of the resistor 9 and when this threshold value U S is exceeded the presence of the rectification effect is identified. In order to monitor the voltage u 3 dropping across the resistor 9, the monitoring circuit arrangement 3 is also connected to earth so that the monitoring point A of the monitoring circuit arrangement 3 cannot accept a potential that is more negative than the earth potential. FIG. 2b shows the characteristic of the potential u 4 that occurs at the monitoring point A. Since the potential u 4 cannot assume a more negative value than the earth potential, the voltage characteristic of u 4 only has positive half-waves that correspond to the positive half-waves of u 3 . If one of these half-waves exceeds the predefined threshold value U S , the monitoring circuit arrangement 3 interprets this as the occurrence of the rectification effect in the gas discharge lamp 10. FIG. 2c in a supplementary manner shows the current characteristic of the current i 2 flowing by way of the additional resistor 8. It can be seen from FIG. 2c that the current i 2 only occurs when the voltage u 4 applied at the monitoring point A is zero. FIG. 3 shows the corresponding voltage and current characteristics for the case where the previously described rectification effect in the gas discharge lamp 10 occurs in the opposite direction to the case described with respect to FIG. 2. In this case, the current i 3 flowing by way of the resistor 9 or the voltage u 3 dropping across the resistor 9 assume values which rise in a negative direction so that the negative half-waves are excessive in respect of the positive half-waves in the voltage characteristic and current characteristic of u 3 and i 3 respectively. In the extreme case in the course of time the positive half-waves disappear completely so that the gas discharge lamp 10 acts as a rectifier in the opposite direction to the direction described with reference to FIG. 2. In the same way as FIG. 2b, FIG. 3b also shows that the potential u 4 that occurs at the monitoring point A on account of the connection of the monitoring circuit arrangement 3 to earth can only assume positive values so that over time with the disappearance of the positive half-waves of the voltage u 3 dropping across the resistor 9 the voltage u 4 assumes the value zero. In order, nevertheless, to be able to identify the presence of the rectification effect in the gas discharge lamp 10 in this case, in accordance with the invention it is proposed that the current i 2 flowing by way of the resistor 8 be evaluated in this case. The current i 2 can only flow by way of the resistor 8 if the voltage u 4 that occurs at the monitoring point A assumes the value zero. For this reason, from the time at which the voltage u 4 completely disappears, the current i 2 can be monitored continuously by the monitoring circuit arrangement 3. The characteristic of the current i 2 is then changed in line with the half-waves of the voltage u 3 rising in the negative direction. For this reason, the rectification effect acting in the other direction of the gas discharge lamp 10 can be identified by monitoring the current i 2 flowing by way of the resistor 8, if this current i 2 exceeds a predetermined limiting value I S . This limiting value I S can be varied in particular by way of the value of the resistor 8. On the basis of the negative current values of the current i 2 represented in FIG. 3c, it can be seen in conjunction with FIG. 1 that the current i 2 flowing out from the monitoring circuit arrangement 3 by way of the monitoring point A is actually detected by the monitoring circuit arrangement 3. By simultaneously monitoring u 3 and also i 2 , the monitoring circuit arrangement 3 can thus reliably identify the rectification effect--irrespective of the direction in which the rectification effect occurs in the gas discharge lamp 10. The monitoring of i 2 and u 3 in order to determine whether the limiting value I S or U S respectively has been exceeded is advantageously effected by means of standard current and voltage comparators. As soon as the monitoring circuit arrangement 3 has identified that the voltage u 4 applied at the monitoring point A has exceeded the predetermined limiting value U S or the current i 2 flowing by way of the monitoring point A has exceeded the predetermined limiting value I S , the monitoring circuit arrangement 3 concludes that the rectification effect is present in the gas discharge lamp 10 and gives out a corresponding warning. The monitoring circuit arrangement 3 is advantageously connected to the inverter 2 and controls the operational performance of the inverter 2 after identification of a rectification effect in the gas discharge lamp 10 in such a way that the power consumed by the gas discharge lamp 10 is reduced. In particular, the monitoring circuit arrangement 3 controls the switching performance of the alternately switching switches of the inverter 2 in such a way that, for example, the frequency f of the switched-mode alternating voltage delivered by the inverter 2 is increased and/or the pulse duty factor d (that is, the relationship between the switch-on times of the two activated switches of the inverter 2) of the switched-mode alternating voltage is reduced so that the lamp current i L supplied to the gas discharge lamp 10 is reduced. In this way, excessive heating or melting of portions of the glass lamp bulb is reliably prevented. If applicable, the monitoring circuit arrangement 3 can also cause the inverter 2 to be switched off. FIG. 4 shows a second exemplary embodiment of the electronic ballast in accordance with the invention, with a two-lamp load circuit being represented in the figure. The second lamp circuit is connected up in a manner analogous to the first lamp circuit. The second lamp circuit likewise comprises a filament-heating transformer, the primary winding 11A of which is connected to the series-resonant circuit and the two secondary windings 11B and 11C of which are connected to the lamp filaments of a second gas discharge lamp 15. Connected in series with the primary winding 11A of the second filament-heating transformer there is a resistor 13, which is additionally connected to earth. A connection leads from the interconnection point between the primary winding 11A of the second filament-heating transformer and the resistor 13 to the monitoring circuit arrangement 3 by way of a resistor 12. The monitoring circuit arrangement 3 has an OR-circuit arrangement 14, the inputs of which are connected to the monitoring points A and B and also to the resistors 8 and 12. Each of the monitoring points A and B is, as explained with reference to FIGS. 2 and 3, monitored for the occurrence of a rectification effect in the gas discharge lamp 10 and 15 respectively. The OR-circuit arrangement 14 signals the presence of a rectification effect as soon as it is possible to identify the rectification effect in one of the two gas discharge lamps 10 and 15 by monitoring the monitoring points A and B. As in the case of the exemplary embodiment shown in FIG. 1, in accordance with FIG. 4 as well after a rectification effect has been identified the inverter 2 is activated in a corresponding manner in order to reduce the power consumed by the gas discharge lamps 10 and 15 connected to the inverter 2. The monitoring circuit arrangement 3 is advantageously designed as an ASIC (Application Specific Integrated Circuit). On account of the proposed manner, in accordance with the invention, of monitoring the heating current which flows by way of the primary windings 7A and 11A of the corresponding filament-heating transformers and the characteristic of which changes greatly when a rectification effect is present in the corresponding gas discharge lamp 10 and 15 respectively, it is possible to identify the rectification effect in the gas discharge lamp 10 and 15 with great precision and in a reliable manner. The circuit arrangement proposed in accordance with the invention can easily be extended by means of simple measures in terms of circuit engineering in order to monitor two or more gas discharge lamps.

Method for detecting the rectification effect in at least one gas discharge lamp (10) and electronic ballast for operating at least one gas discharge lamp, which recognises the appearance of the rectification effect in the gas discharge lamp (10). In order to be able to detect the appearance of the rectification effect in the gas discharge lamp (10) simply and with high sensitivity there is monitored the current (i 1 ) flowing via a primary winding (7A), connected parallel to the gas discharge lamp (10), of a heating transformer (7A-C) or a parameter (i 2 , u 3 ) dependent upon this current (i 1 ) , and in the event that a predetermined limit value is overshot the presence of the rectification effect in the gas discharge lamp (10) is determined.

FIELD OF THE INVENTION This invention relates to azeotrope-like mixtures of 2-trifluoromethyl-1,1,1,2-tetrafluorobutane. These mixtures are useful in a variety of vapor degreasing, cold cleaning and solvent cleaning applications including defluxing and dry cleaning. BACKGROUND OF THE INVENTION Vapor degreasing and solvent cleaning with fluorocarbon based solvents have found widespread use in industry for the degreasing and otherwise cleaning of solid surfaces, especially intricate parts and difficult to remove soils. In its simplest form, vapor degreasing or solvent cleaning consists of exposing a room temperature object to be cleaned to the vapors of a boiling solvent. Vapors condensing on the object provide clean distilled solvent to wash away grease or other contamination. Final evaporation of solvent from the object leaves behind no residue as would be the case where the object is simply washed in liquid solvent. For difficult to remove soils where elevated temperature is necessary to improve the cleaning action of the solvent, or for large volume assembly line operations where the cleaning of metal parts and assemblies must be done efficiently and quickly, the conventional operation of a vapor degreaser consists of immersing the part to be cleaned in a sump of boiling solvent which removes the bulk of the soil, thereafter immersing the part in a sump containing freshly distilled solvent near room temperature, and finally exposing the part to solvent vapors over the boiling sump which condense on the cleaned part. In addition, the part can also be sprayed with distilled solvent before final rinsing. Vapor degreasers suitable in the above-described operations are well known in the art. For example, Sherliker et al. in U.S. Pat. No. 3,085,918 disclose such suitable vapor degreasers comprising a boiling sump, a clean sump, a water separator, and other ancillary equipment. Cold cleaning is another application where a number of solvents are used. In most cold cleaning applications, the soiled part is either immersed in the fluid or wiped with rags or similar objects soaked in solvents and allowed to air dry. Fluorocarbon solvents, such as trichlorotrifluoroethane, have attained widespread use in recent years as effective, nontoxic, and nonflammable agents useful in degreasing applications and other solvent cleaning applications. Trichlorotrifluoroethane has been found to have satisfactory solvent power for greases, oils, waxes and the like. It has therefore found widespread use for cleaning electric motors, compressors, heavy metal parts, delicate precision metal parts, printed circuit boards, gyroscopes, guidance systems, aerospace and missile hardware, aluminum parts and the like. Azeotropic or azeotrope-like compositions are desired because they do not fractionate upon boiling. This behavior is desirable because in the previously described vapor degreasing equipment with which these solvents are employed, redistilled material is generated for final rinse-cleaning. Thus, the vapor degreasing system acts as a still. Unless the solvent composition exhibits a constant boiling point, i.e., is azeotrope-like, fractionation will occur and undesirable solvent distribution may act to upset the cleaning and safety of processing. Preferential evaporation of the more volatile components of the solvent mixtures, which would be the case if they were not azeotrope-like, would result in mixtures with changed compositions which may have less desirable properties, such as lower solvency towards soils, less inertness towards metal, plastic or elastomer components, and increased flammability and toxicity. The art has looked towards azeotrope or azeotrope-like compositions including the desired fluorocarbon components such as trichlorotrifluoroethane which include components which contribute additionally desired characteristics, such as polar functionality, increased solvency power, and stabilizers. The art is continually seeking new fluorocarbon, hydrofluorocarbon, and hydrochlorofluorocarbon based azeotrope-like mixtures which offer alternatives for new and special applications for vapor degreasing and other cleaning applications. Currently, of particular interest, are fluorocarbon, hydrofluorocarbon, and hydrochlorofluorocarbon based azeotrope-like mixtures with minimal or no chlorine which are considered to be stratospherically safe substitutes for presently used chlorofluorocarbons (CFCs). The latter are suspected of causing environmental problems in connection with the earth's protective ozone layer. Mathematical models have substantiated that hydrofluorocarbons, such as 2-trifluoromethyl-1,1,1,2-tetrafluorobutane (known in the art as HFC-467), will not adversely affect atmospheric chemistry, being negligible contributors to ozone depletion and to green-house global warming in comparison to chlorofluorocarbons such as 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). European Publication 431,458 published Jun. 12, 1991 teaches a mixture of 1,1,2,3,4,4-hexafluorobutane and ethanol. U.S. Pat. No. 5,023,010 teaches an azeotropic mixture of 1,1,1,2,3,3-hexafluoro-3-methoxypropane and methanol. U.S. Pat. No. 5,035,830 teaches an azeotropic mixture of hexafluoropropylene/ethylene cyclic dimer and methanol or ethanol. U.S. Pat. No. 5,064,559 teaches an azeotropic mixture of 1,1,1,2,3,4,4,5,5,5-decafluoropentane and methanol or ethanol. U.S. Pat. No. 5,073,291 teaches an azeotrope-type mixture of 1,4-dihydroperfluorobutane and methanol. U.S. Pat. Nos. 5,073,288 and 5,073,290 teach binary azeotrope-like compositions of 1,1,1,2,2,3,5,5,5-nonafluoro-4-trifluoromethylpentane or 1,1,1,2,2,5,5,5-octafluoro-4-trifluoromethylpentane and methanol or ethanol. DETAILED DESCRIPTION OF THE INVENTION Our solution to the need in the art for substitutes for chlorofluorocarbon solvents is mixtures comprising 2-trifluoromethyl-1,1,1,2-tetrafluorobutane and ethanol or isopropanol and optionally nitromethane. Also, novel azeotrope-like or constant-boiling compositions have been discovered comprising 2-trifluoromethyl-1,1,1,2-tetrafluorobutane and ethanol or isopropanol and optionally nitromethane. Preferably, the novel azeotrope-like compositions comprise effective amounts of 2-trifluoromethyl-1,1,1,2-tetrafluorobutane and ethanol or isopropanol and optionally nitromethane. The term "effective amounts" as used herein means the amount of each component which upon combination with the other component, results in the formation of the present azeotrope-like compositions. The azeotrope-like compositions comprise from about 64 to about 99.5 weight percent of 2-trifluoromethyl-1,1,1,2-tetrafluorobutane and from about 0.5 to about 36 of ethanol or isopropanol and from 0 to about 1 weight percent nitromethane. The present azeotrope-like compositions are advantageous for the following reasons. The 2-trifluoromethyl-1,1,1,2-tetrafluorobutane is a negligible contributor to ozone depletion and has a boiling point of 37° C. The ethanol and isopropanol components have good solvent properties. Thus, when these components are combined in effective amounts, an efficient azeotrope-like solvent results. The preferred ethanol based azeotrope-like compositions are in Table I below where 2-trifluoromethyl-1,1,1,2-tetrafluorobutane is abbreviated as HFC-467: TABLE I______________________________________ MORE MOST PRE- PRE- PRE- BOILING FERRED FERRED FERRED POINTCOM- RANGE RANGE RANGE (°C.)PONENTS (WT. %) (WT. %) (WT. %) (760mmHg)______________________________________HFC-467 64-99.5 79.5-99 84.6-98.5 36.5 ± 0.5Ethanol 0.5-36 1-20.5 1.5-15.4Nitromethane 0-1 0-0.5 0-0.4______________________________________ The preferred isopropanol based azeotrope-like compositions are in Table II below where 2-trifluoromethyl-1,1,1,2-tetrafluorobutane is abbreviated as HFC-467: TABLE II______________________________________ MORE MOST PRE- PRE- PRE- BOILING FERRED FERRED FERRED POINTCOM- RANGE RANGE RANGE (°C.)PONENTS (WT. %) (WT. %) (WT. %) (760mmHg)______________________________________HFC-467 71.5-99.5 78.3-99 82.9-98.6 38.1 ± 0.5Isopropanol 0.5-28.5 1-21.7 1.4-17.1Nitromethane 0-1 0-0.5 0-0.4______________________________________ All compositions within the indicated ranges, as well as certain compositions outside the indicated ranges, are azeotrope-like, as defined more particularly below. The precise azeotrope compositions have not been determined but have been ascertained to be within the above ranges. Regardless of where the true azeotropes lie, all compositions with the indicated ranges, as well as certain compositions outside the indicated ranges, are azeotrope-like, as defined more particularly below. The term "azeotrope-like composition" as used herein is intended to mean that the composition behaves like an azeotrope, i.e. has constant-boiling characteristics or a tendency not to fractionate upon boiling or evaporation. Thus, in such compositions, the composition of the vapor formed during boiling or evaporation is identical or substantially identical to the original liquid composition. Hence, during boiling or evaporation, the liquid composition, if it changes at all, changes only to a minimal or negligible extent. This is to be contrasted with non azeotrope like compositions in which during boiling or evaporation, the liquid composition changes to a substantial degree. As is readily understood by persons skilled in the art, the boiling point of the azeotrope-like composition will vary with the pressure. The azeotrope-like compositions of the invention are useful as solvents in a variety of vapor degreasing, cold cleaning and solvent cleaning applications including defluxing and dry cleaning. In one process embodiment of the invention, the azeotrope-like compositions of the invention may be used to dissolve contaminants or remove contaminants from the surface of a substrate by treating the surfaces with the compositions in any manner well known to the art such as by dipping or spraying or use of conventional degreasing apparatus wherein the contaminants are substantially removed or dissolved. The 2-trifluoromethyl-1,1,1,2-tetrafluorobutane of the present azeotrope-like compositions may be prepared by reacting commercially available 4-iodo-2-trifluoromethyl-1,1,1,2-tetrafluorobutane with zinc and hydrogen chloride. The ethanol; isopropanol; and nitromethane components of the novel solvent azeotrope-like compositions of the invention are known materials and are commercially available. The present invention is more fully illustrated by the following non-limiting Examples. EXAMPLE 1 This Example is directed to the preparation of 2-trifluoromethyl-1,1,1,2-tetrafluorobutane. A 500 milliliter flask fitted with a mechanical stirrer, distillation column, and take-off head was charged with 15 grams (0.046 mole) of commercially available 4-iodo-2-trifluoromethyl-1,1,1,2-tetrafluorobutane, 28.5 grams (0.45 mole) zinc dust, and 230 milliliters of 10% hydrogen chloride. The mixture was stirred and heated to 50° C. and 7.4 grams (80% yield) of distillate (boiling point 37° C.-39° C.) was collected. 1H NMR (CDCl 3 ): 2.1 (m, 2H), 1.2 (t, 3 H) ppm. EXAMPLE 2 This example shows that a minimum in the boiling point versus composition curve occurs in the region of 88.7 weight percent 2-trifluoromethyl-1,1,1,2-tetrafluorobutane (hereinafter HFC-467) and 11.3 weight percent ethanol indicating that an azeotrope forms in the neighborhood of this composition. A microebulliometer which consisted of a 15 milliliter round bottom double neck flask containing a magnetic stirbar and heated with an electrical heating mantel was used. Approximately 2.5 milliliters of the lower boiling material, HFC-467, was charged into the microebulliometer and ethanol was added in small measured increments by an automated syringe capable of injecting microliters. The temperature was measured using a platinum resistance thermometer and barometric pressure was measured. An approximate correction to the boiling point was done to obtain the boiling point at 760 mm Hg. The boiling point was measured and corrected to 760 mm Hg (101 kPa) for various mixtures of HFC-467 and ethanol. Interpolation of the data shows that a minimum boiling point occurs in the region of about 1.5 to about 18 weight percent ethanol. The best estimate of the position of the minimum is 11.3 weight percent ethanol, although the mixtures are constant-boiling, to within 0.3° C., in the region of 0.5 to 35 weight percent ethanol. A minimum boiling azeotrope is thus shown to exist in this composition range. From the above example, it is readily apparent that additional constant-boiling or essentially constant-boiling mixtures of the same components can readily be identified by anyone of ordinary skill in this art by the method described. No attempt was made to fully characterize and define the outer limits of the composition ranges which are constant-boiling. Anyone skilled in the art can readily ascertain other constant-boiling or essentially constant-boiling mixtures containing the same components. EXAMPLE 3 Example 2 was repeated except that isopropanol (purity 90%) was used instead of ethanol. Approximately 2.8 milliliters of the lower boiling material, HFC-467, were initially charged into the microebulliometer and isopropanol was added in small measured increments by an automated syringe capable of injecting microliters. The boiling point was measured and corrected to 760 mm Hg (101 kPa), for various mixtures of HFC-467 and isopropanol. Interpolation of these data shows that a minimum boiling point occurs in the region of about 1.4 to about 17.7 weight percent isopropanol. The best estimate of the position of the minimum is 8 weight percent isopropanol, although the mixtures are constant-boiling, to within 0.3° C., in the region of 0.5 to 27.5 weight percent isopropanol. A minimum boiling azeotrope is thus shown to exist in this composition range. EXAMPLES 4 AND 5 Performance studies are conducted wherein metal coupons are cleaned using the present azeotrope-like compositions as solvents. The metal coupons are soiled with various types of oils and heated to 93° C. so as to partially simulate the temperature attained while machining and grinding in the presence of these oils. The metal coupons thus treated are degreased in a three-sump vapor phase degreaser machine. In this typical three-sump degreaser, condenser coils around the lip of the machine are used to condense the solvent vapor which is then collected in a sump. The condensate overflows into cascading sumps and eventually goes into the boiling sump. The metal coupons are held in the solvent vapor and then vapor rinsed for a period of 15 seconds to 2 minutes depending upon the oils selected. The azeotrope-like compositions of Examples 2 and 3 are used as the solvents. Cleanliness testing of the coupons is done by measurement of the weight change of the coupons using an analytical balance to determine the total residual materials left after cleaning. EXAMPLES 6 AND 7 Each solvent of Examples 2 and 3 above is added to mineral oil in a weight ratio of 50:50 at 27° C. Each solvent is miscible in the mineral oil. EXAMPLES 8 AND 9 Metal coupons are soiled with various types of oil. The soiled metal coupons are immersed in the solvents of Examples 2 and 3 above for a period of 15 seconds to 2 minutes, removed, and allowed to air dry. Upon visual inspection, the soil appears to be substantially removed. EXAMPLES 10 AND 11 Metal coupons are soiled with various types of oil. The soiled metal coupons are sprayed with the solvents of Examples 2 and 3 above and allowed to air dry. Upon visual inspection, the soil appears to be substantially removed. Inhibitors may be added to the present azeotrope-like compositions to inhibit decomposition of the compositions; react with undesirable decomposition products of the compositions; and/or prevent corrosion of metal surfaces. Any or all of the following classes of inhibitors may be employed in the invention: alkanols having 4 to 7 carbon atoms, nitroalkanes having 2 to 3 carbon atoms, 1,2-epoxyalkanes having 2 to 7 carbon atoms, phosphite esters having 12 to 30 carbon atoms, ethers having 3 or 4 carbon atoms, unsaturated compounds having 4 to 6 carbon atoms, acetals having 4 to 7 carbon atoms, ketones having 3 to 5 carbon atoms, and amines having 6 to 8 carbon atoms. Other suitable inhibitors will readily occur to those skilled in the art. The inhibitors may be used alone or in mixtures thereof in any proportions. Typically, up to about 2 percent based on the total weight of the azeotrope-like composition of inhibitor might be used. When the present azeotrope-like compositions are used to clean solid surfaces by spraying the surfaces with the compositions, preferably, the azeotrope-like compositions are sprayed onto the surfaces by using a propellant. Preferably, the propellant is selected from the group consisting of hydrocarbons, chlorofluorocarbons, hydrochlorofluorocarbon, hydrofluorocarbon, dimethyl ether, carbon dioxide, nitrogen, nitrous oxide, methylene oxide, air, and mixtures thereof. Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

Azeotrope-like compositions comprising 2-trifluoromethyl-1,1,1,2-tetrafluorobutane and ethanol or isopropanol and optionally nitromethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to engines driven by pistons most usually and more particularly to internal combustion engines. These mechanisms are particularly useful for converting the reciprocating notion of a powered piston to a rotating output movement. Most conventional engines included at multiple cylinders in which a piston reciprocates. The piston is then connected to an output crank by an elongated connecting rod pivoted at the upper end to the piston at the lower end to the crank. It is conventional that the output of the powers for such an engine and, in particular, for internal combustion engines, is the crankshaft rotary output. It is the unique configuration of the present invention to provide an energy efficient easily maintained functional replacement for that design. 2. Description of the Prior Art Many patents have been granted to internal combustion designs utilizing gearing mechanisms for drives such as U.S. Pat. No. 1,316,437 patented Sep. 16, 1919 to H. L. Flood on a "Rack And Pinion Mechanism For Engines"; and U.S. Pat. No. 1,399,900 patented Dec. 13, 1921 to C. G. Sprado and assigned to Allis-Chalmers Manufacturing Company on a "Method Of And Apparatus For Manipulating Internal-Combustion Engines"; and U.S. Pat. No. 1,434,146 patented Oct. 31, 1922 to A. L. Powell and assigned to A. L. Powell Power Co. on an "Internal-Combustion Engine"; and U.S. Pat. No. 1,496,490 patented Jun. 3, 1924 to A. L. Powell and assigned to A. L. Powell Power Co. on a "Transmission For Engines"; and U.S. Pat. No. 1,567,172 patented Dec. 29, 1925 to A. L. Powell and assigned to A. L. Powell Power Co., Inc. on an "Internal-Combustion Engine"; and U.S. Pat. No. 1,569,582 patented Jan. 12, 1926 to C. W. Scott on an "Internal-Combustion Engine"; and U.S. Pat. No. 1,583,368 patented May 4, 1926 to A. L. Powell and assigned to A. L. Powell Power Company Incorporated on a "Transmission For Engines"; and U.S. Pat. No. 1,636,612 patented Jul. 19, 1927 to L. H. Noah on an "Internal-Combustion Engine"; and U.S. Pat. No. 1,687,744 patented Oct. 16, 1928 to F. M. Webb on a "Reciprocating Engine"; and U.S. Pat. No. 1,705,930 patented Mar. 19, 1929 to R. E. Leonard and assignment of one-half to David G. Lorraine on a "Long-Stroke Pump-Operating Mechanism"; and U.S. Pat. No. 1,708,888 patented Apr. 9, 1929 to I. N. Keeling and assignment of one-fourth to Andrew J. parks on a "Mechanical Movement"; and U.S. Pat. No. 1,735,543 patented Nov. 12, 1929 to V. H. Palm on an "Internal Combustion Engine"; and U.S. Pat. No. 1,885,298 patented Nov. 1, 1932 to A. A. Schell on an "Internal Combustion Engine"; and U.S. Pat. No. 2,088,504 patented Jul. 27, 1937 to E. Brzezinski on a "Crankless Motor"; and U.S. Pat. No. 2,155,497 patented Apr. 25, 1939 to A. Latil on a "Transforming Alternating Rectilinear Movement Into Continuous Rotary Movement"; and U.S. Pat. No. 2,334,684 patented Nov. 16, 1943 to A. T. Zappia and assigned to Fairmount Glass Works, Inc. on an "Intermittent Drive Mechanism"; and U.S. Pat. No. 2,337,330 patented Dec. 21, 1943 to Z. J. Julin on a "Driving Mechanism"; and U.S. Pat. No. 2,482,136 patented Sep. 20, 1949 to W. N. Wright on an "Engine"; and U.S. Pat. No. 3,528,319 patented Sep. 15, 1970 to Kenjiro Ishida and assigned to President Shizuoka University on a "Perfectly Balanced Vibrationless Rotation-Reciprocation Device Of Crankshaft Planetary Motion System"; and U.S. Pat. No. 3,604,204 patented Sep. 14, 1971 to H. Conrad et al and assigned to Fried Krupp Gesellschaft mit beschrankter Haftung on a "Counterpiston Machine, Especially Counterpiston Motor"; and U.S. Pat. No. 3,895,620 patented Jul. 22, 1975 to B. Foster on an "Engine And Gas Generator"; and U.S. Pat. No. 3,916,866 patented Nov. 4, 1975 to J. M. Rossi on an "Engine Having Reciprocating Piston And Rotary Piston"; and U.S. Pat. No. 3,991,736 patented Nov. 16, 1976 to R. C. Spellman and assigned to Raymond Lee Organization, Inc. on a "Ratchet Driving Internal Combustion Engine"; and U.S. Pat. No. 4,135,409 patented Jan. 23, 1979 to R. Ishimaru on a "Device For Converting Rocking Motion Into Reciprocating Rotary Motion"; and U.S. Pat. No. 4,411,165 patented Oct. 25, 1983 to L. Evans on a "Power Transmission Unit With Infinite Speeds"; and U.S. Pat. No. 4,465,042 patented Aug. 14, 1984 to R. Bristol on a "Crankless Internal Combustion Engine"; and U.S. Pat. No. 4,803,964 patented Feb. 14, 1989 to W. Kurek et al on an "Internal Combustion Engine"; and U.S. Pat. No. 4,890,589 patented Jan. 2, 1990 to H. Miyate and assigned to Nissan Shatai Company, Limited on a "Variable Capacity Type Reciprocating Piston Device"; and U.S. Pat. No. 4,938,186 patented Jul. 3, 1990 to L. Pal et al on an "Internal Combustion Engine Variable Stroke Mechanism"; and U.S. Pat. No. 4,951,615 patented Aug. 28, 1990 to N. Pahis on a "Motion-Conversion Mechanism For A Four Stroke Oscillating Piston Internal Combustion Engine". SUMMARY OF THE INVENTION The present invention provides an improved drive mechanism used for a reciprocating piston engine which includes a housing block defining multiple cylinders therein and preferably four such cylinders. A crankshaft is rotatably mounted within the housing block and includes a plurality of piston journals defined thereon. Preferably the crankshaft where mounted within the housing block includes crankshaft support journals therein to facilitate rotational movement of the crankshaft with respect to the housing block. A piston member is included positioned within each of the cylinders defined by the housing block such as to be movably axially therewithin. Each of the pistons preferably includes a piston head drive surface and a piston leg extending therefrom preferably downwardly. The piston leg is preferably fixedly secured with respect to the piston and is oriented perpendicularly with respect to the piston head drive surface. In this manner each of the pistons and the piston legs will be adapted to move axially within the cylinder without any component of movement thereof whatsoever laterally with respect to the axis of the particular cylinder. As such, conventional wobble of a piston head resulting from off-axis movement of a conventional connecting rod is avoided. A piston link arm apparatus is included pivotally attached with respect to each of the piston legs and pivotally attached with respect to the piston journal. The piston link arm preferably includes a first link arm end pivotally secured to the piston leg. Also the piston link arm preferably includes a second link arm end pivotally secured with respect to one of the piston journals. This second link arm also is positioned to be spatially disposed on the piston link arm remotely from the location of the first link arm in such a manner as to mechanically create pivotal linkage interconnecting the piston with respect to the crankshaft. A piston pin may also be included extending through the first link arm end and the piston leg in order to maintain the pivotal engagement therebetween. A power driveshaft is also included rotatably mounted within the housing block adjacent the path of movement of each of the piston legs. An idler driveshaft may also be included rotatably mounted within the housing block at a location opposite from the position of the power driveshaft. This idler driveshaft is preferably positioned extending generally parallel with respect to the power driveshaft and opposite therefrom with the path of movement of the piston leg positioned therebetween. A plurality of power clutch bearings are fixedly secured on each of the power driveshafts adjacent each of the piston legs. Each of these power clutch bearings include a power inner race fixedly secured to the power driveshaft and a power outer race. The power clutch bearings are adapted to provide the power inner race in fixed securement with respect to the power outer race only responsive to rotation thereof in a first power direction which is preferably clockwise. They are adapted to provide freewheeling relative rotatable attachment therebetween responsive to rotation thereof in a second power direction normally being counterclockwise. A plurality of power drive gears are each mounted securely to the power outer race of the one of the power clutch bearings. A plurality of power rack gears are preferably fixedly secured to the piston legs and are movable therewith adjacent the power driveshaft means. They are also preferably in engagement with the power driving gear mounted on the power driveshaft thereadjacent. The power rack gear also is preferably reciprocally movable with the piston leg and is maintained in continuous engagement with the power driving gear located thereadjacent. A power timing gear is preferably fixedly secured to the power driveshaft adjacent the output end thereof. A plurality of idler clutch bearings are fixedly secured onto the idler driveshaft adjacent each of the piston legs. Each of these idler clutch bearings include an idler inner race fixedly secured to the idler driveshaft and an idler outer race. The idler clutch bearing is adapted to provide the idler inner race in fixed securement with respect to the idler outer race responsive to rotation thereof in a first idler direction being preferably counterclockwise. It is also adapted to provide freewheeling rotatable attachment therebetween responsive to rotation thereof in a second idler direction which preferably is clockwise. A plurality of idler drive gears are included each mounted directly to the idler outer race of one of the idler clutch bearings. Also multiple idler rack gears are included each being fixedly secured to the piston leg and movable therewith adjacent the idler driveshaft. Each idler rack gear is in engagement with the idler driving gear mounted on the idler driveshaft thereadjacent. The idler rack gear is preferably reciprocally movable with the piston leg and maintained in continuous engagement with the idler driving gear located thereadjacent. Each of these idler rack gears are preferably oppositely positioned on the piston leg from the power rack gear located thereon. An idler timing gear is preferably fixedly secured to the idler driveshaft adjacent to the power timing gear and in operative engagement therewith in order to facilitate driving of the power driveshaft by the idler driveshaft at certain points in the cycle of reciprocating motion of this engine. A power output shaft may preferably be fixedly secured with respect to the power driveshaft in such a manner as to be axially coincident therewith in order to provide access to power for delivery as desired. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein maintenance requirements are minimized. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein initial capital cost outlay for producing the assembly is minimized. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein down time is minimized. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein output power is provided at an output shaft other than the crankshaft. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein rocking of pistons moving through the cylindrical cylinders is minimized. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein oil consumption is minimized. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein cylinder wear is minimized. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein less heat is generated in the engine generally and within the cylinders specifically. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with diesel and/or gasoline powered or other powered engine configurations is possible. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein the cost of production of the crankshaft can be greatly minimized since it requires less weight because it does not provide the source of drive output from the motor. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with a conventional internal combustion engine is possible. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with any fluid powered piston engine is possible including both pneumatic and hydraulic power piston systems. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein the unique combination and positioning of clutch bearings provide continuous power to the output shaft, which provides frictional power to the crankshaft. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with any number of multiple cylinders is possible. It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with any conventional valve configurations is made possible. BRIEF DESCRIPTION OF THE DRAWINGS While the invention is particularly pointed out and distinctly claimed in the concluding portions herein, a preferred embodiment is set forth in the following detailed description which may be best understood when read in connection with the accompanying drawings, in which: FIG. 1 is a perspective illustration of an embodiment of the improved drive mechanism for a reciprocating piston engine of the present invention; FIG. 2 is an end plan view of the embodiment shown in FIG. 1 as viewed from the left; FIG. 3 is a rear plan view of the embodiment shown in FIG. 1 as viewed from the right; FIG. 4 is a side plan view of the embodiment shown in FIG. 1 with the outer pistons in the uppermost position and the inner pistons in the lowermost position; FIG. 5 is the same view shown in FIG. 4 with the inner pistons in the uppermost position and the outermost pistons in the lowermost position; FIG. 6 is a front plan view of an embodiment of a power clutch bearing made in accordance with the present invention; and FIG. 7 is front plan view of the an embodiment of an idler clutch bearing made in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The improved drive mechanism for a reciprocating piston engine of the present invention includes a housing block 10 defining a plurality of individual cylinders 12 thereon. Preferably cylinders 12 are of a cylindrical cross section. A crankshaft 14 is rotatably mounted within the housing block 10 to facilitate rotation of crankshaft 14. It can include a plurality of crankshaft journals 18 thereon which are designed to be mounted within bearings in the housing block 10 in the conventional manner. The crankshaft 14 preferably also defines a plurality of piston journals 16 adjacent to each of the cylinders 12 to facilitate interconnection of the crankshaft with respect to the pistons located therewithin. A piston means 20 is preferably movably positioned within each of the cylinders 12. Each piston 20 includes a piston leg 24 fixedly secured thereto and extending downwardly therefrom. Each piston 20 also includes a piston head drive surface 22 facing the interior portion of the cylinder 12 to receive power transmitted therefrom. In the preferred orientation of the pistons 20 of the present invention the individual piston leg 24 will be oriented perpendicularly with respect to the piston head drive surface 22. The pistons 20 are designed to move as shown in FIG. 2 vertically along a cylindrical axis 26 within the cylinder 12. One of the important aspects of the present invention is that the piston 20 only has a vertical component of movement and has no lateral movement component 28 as shown in FIG. 3. The vertical movement component shown by arrow 23 is designed to smoothly slide along the interior wall surfaces of cylinder 12. Since there is no lateral movement component 28 in the apparatus of the present invention a distinct improvement over prior art internal combustion engines is achieved. The elimination of such lateral movement or wobble significantly reduces wear on the interior walls of the cylinder which enhances performance, efficiency and significantly reduces oil consumption thereof. In order to maintain this vertical orientation during movement of the piston, a piston link arm 30 is preferably positioned interconnecting the piston leg 24 with the piston journal 16. This piston link arm 30 preferably includes a first link arm end 32 and a second link arm end 36 spatially disposed with respect to one another preferably at opposite ends at the piston link arm 30. The first link arm means 32 is preferably secured to the piston leg 24 by a piston pin 34. The use of this piston pin 34 enhances the pivotal yet secure interconnection between the first link arm end 32 of piston link arm 30 and the piston leg 24. The opposite end of the piston link arm 30 which is defined as the second link arm end 36 is preferably pivotally secured with respect to piston journal 16 on the crankshaft 14. A very important aspect of the present invention is the inclusion of a power driveshaft 38 rotatably mounted within the housing block 10 preferably at a position above the crankshaft and running along one side of the cylinders 12. Power driveshaft 38 is preferably mounted in a plurality of power driveshaft journals 40 defined within housing block 10. On the opposite side of the cylinders 12 from the power driveshaft 38 is preferably located an idler driveshaft 42. Preferably idler driveshaft 42 is rotatably mounted within a plurality of idler driveshaft journals 44 defined within the housing block 10. The power driveshaft 38 and the idler driveshaft 42 are preferably spaced apart from one another and extend parallel with respect to one another and provides a means for withdrawing power from the apparatus of the present invention and for maintaining the piston 20 in vertical orientation during movement thereof. A plurality of power clutch bearings 46 are mounted on the power driveshaft 38 at each location thereof immediately adjacent to one of the cylinders 12. Power clutch bearing 46 includes a power inner race 48 as well as a power outer race 50 movably oriented with respect to one another. A power drive gear 56 is positioned fixedly secured to the power outer race 50 at each location of positioning of the power clutch bearing 46 adjacent each of the pistons 20. A power rack gear 58 is positioned fixedly secured with respect to the piston leg 24 and extending vertically at a position immediately adjacent to the power drive gear 56. Power timing gear 60 and idler timing gear 76 are positioned with the gear teeth thereof in engagement with respect to one another at all times. The configuration of the power clutch bearing 46 is such that rotation of the outer race 50 in a clockwise direction as shown in FIG. 2 causes similar clockwise rotation of the power inner race 48. However, as also shown in FIG. 2, rotation of the power outer race 50 counterclockwise with respect to the power inner race 48 will be freewheeling as controlled by the power clutch bearing 46. Clutch bearing 46, thus, is designed such that whenever power outer race 50 is rotated clockwise during movement of the piston 20 toward the crankshaft 14 a similar rotational movement will occur of the power inner race 48 and consequently the power driveshaft 38 resulting from powered engagement of the teeth of the power rack gear 58 in engagement with the power drive gear 56. This configuration is included for each of the cylinders 12. In a similar manner the power clutch bearing 46 is designed to disengage the power inner race 48 from the power outer race 50 and allows freewheeling thereof whenever, as shown in FIG. 2, the power outer race 50 is rotated in the counterclockwise direction 54. During that portion of the stroke one of the other cylinders will be in the drive mode causing rotation of its associated gearing mechanism for maintaining continuous drive powering of the engine of the present apparatus. With respect to the configuration shown in FIG. 2, whenever the piston 20 is moved toward the crankshaft 14 the power clutch bearing 46 will be in the drive mode firmly interconnecting the power inner race 48 with respect to the power outer race 50 causing driving movement. This results from movement in the first power direction 52 which is clockwise as shown in FIG. 2. The second power direction 54 is as described above, however, there is no connection within the clutch bearing during movement in that counterclockwise direction. This results in a freewheeling relationship between the power inner race 48 and the power outer race 50. The power driveshaft 38 so driven by the above described configuration will provide power output through a power output shaft 78 which is preferably axially coincident thereto and extending outwardly from the housing block 10. To provide continuous power to the output shaft 78 the present invention includes a supplementary power driving shaft. This is defined as the idler driveshaft 42. Outer driveshaft 42 is of a similar configuration to the power driveshaft 38 but is oppositely positioned with respect to the piston legs 24. The idler driveshaft 42 is driven and includes an idler timing gear 76 in engagement with a power timing gear 60 fixedly secured to the power driveshaft 38 adjacent the power output shaft 78 thereof. Powering of the idler driveshaft 42 thus will achieve powering of the power output shaft 78 due the engagement between the idler timing gear 76 and the power timing gear 60. The idler driveshaft 42 is crafted to a similar configuration as is the power driveshaft 38. Idler driveshaft 42 includes a plurality of idler clutch bearings 62 positioned thereon at each location immediately adjacent to a cylinder 12. Each idler clutch bearing 62 includes an idler inner race 64 and an idler outer race 66 which have controlled movement with respect to one another as controlled by the idler clutch bearing 62. Whenever the idler outer race 66 is moved as shown in FIG. 2 in the first idler direction 68, which in this configuration is the counterclockwise direction, then the idler inner race 64 and the idler outer race 66 are firmly secured with respect to one another causing driving of the idler inner race. Since the idler inner race is fixedly secured with respect to the idler driveshaft 42, power driving thereof is caused by rotation of the idler outer race 66 in the counterclockwise direction. The idler outer race 66 is adapted to receive an idler drive gear 72 mounted thereon. This idler drive gear 72 is adapted to engage the teeth of an idler rack gear 74 which is fixedly secured with respect to a piston leg 24. Normally such a piston leg 24 will include an idler rack gear 74 on one side thereof and a similarly configured power rack gear 58 on the opposite side thereof. The idler rack gear 74 being in engagement with respect to the idler drive gear 72 will cause rotation thereof. Whenever the piston 20 is moved toward the crankshaft 14 the idler rack gear 74 will cause rotation of the idler drive gear 72 as shown in FIG. 2 in the counterclockwise direction which is the drive direction for the idler clutch bearing 62. Thus, the idler inner race 64 will be rotating in a counterclockwise direction and cause drive rotation of the idler driveshaft 42. Whenever the piston 20 is moving in a direction away from the crankshaft 14 the idler rack gear 74 will cause clockwise rotation of the drive gear 72 and the idler outer race 66 secured thereto. This clockwise rotation is defined as the second idler direction 70 as shown in FIG. 2 which is freewheeling. The idler clutch bearing 62 defines such clockwise movement to be freewheeling and, as such, is the directional movement for non-power or non-driving driving of the idler driveshaft 42. By positioning of the idler rack gear 74 and the power rack gear 58 on opposite vertically extending sides of the piston leg 24, it will be wedged between the idler drive gear 72 and the power drive gear 56 within each cylinder configuration 12. As such, the piston 20 and the piston leg 24 will be always maintained in a vertical orientation to allow vertical movement 23 and to prevent any lateral movement component 28. The use of both the power driveshaft 38 and the idler driveshaft 42 provides an overall balance configuration which enhances the stability and strength and efficiency of operation of the drive mechanism for the reciprocating piston engine of the present invention. Thus we see that each of the pistons will alternately drive the idler drive gear 72 and the power drive gear 56 associated therewith depending on whether the piston is in power stroke moving downwardly. When moving downwardly in power stroke, the power is applied to the two power shaft, namely, the power driveshaft 38 and the idler driveshaft 42. Movement upward in the non-powered movement direction of the piston will result in freewheeling as controlled by the idler clutch bearing 62 and power clutch bearing 46. Fixed interconnection of the power driveshaft 38 with respect to the idler driveshaft 42 is achieved through the full and continuous engagement of the idler timing gear 76 with respect to the power timing gear 60. Coordinated movement of these parts provides power output to the power output shaft 78 axially coincident with the power driveshaft 38. Normally this power output shaft would be connected with respect to a flywheel or torque converter or other device that can be powered by a rotating driveshaft. This power output shaft 78 provides the power takeoff for the improved drive mechanism of the engine of the present invention. One of the important aspects of the present invention is that the crankshaft is not used as the means for transmitting power output. As a result the crankshaft of the present invention can be with much smaller parts since strength is not required. Thus, the cost of manufacturing and the weight of the crankshaft can be significantly reduced. The power is applied through the combination of the power driveshaft 38 and the idler driveshaft 42 which pinches the piston legs 24 between the drive gears mounted thereon for maintaining vertical orientation of the pistons within the cylinders and for receiving balanced coordinated power. The use of two powering shafts eliminates the necessity for a single extremely heavy duty power output shaft such as the crankshaft of a conventional internal combustion engine. Such parts tend to provide the weak link in regard to maintenance and construction of such engine assemblies. By avoiding the wobble or rocking of the individual pistons wear of the interior portion of the cylinders 12 is minimized. Less heat is also generated at this location and less oil is used. It should be appreciated that the apparatus of the present invention can be utilized with any type of piston powering system such as conventional internal combustion utilizing diesel or gasoline for power or any other fluid system such as hydraulic or pneumatic powering systems. The configuration of the driveshafts of the present invention is made possible by the clutch bearings which provide full drive in one direction and full freewheeling in the opposite direction. Such clutch bearings are readily available. Often movement in the freewheeling direction is also defined in such clutch bearings to be the overrun mode and movement in the drive direction is defined to be movement in the lock mode. It should be appreciated that a single clutch bearing component can comprise both the power clutch bearings 46 and the idler clutch bearings 62 of the present invention. Although we have included two separate figures to show these two bearings, actually the two bearing configurations can be provided by a single clutch bearing part merely by reversing the direction of the bearing axis to provide a clutch bearing which drives in the opposite direction on one side and in the freewheeling direction also oppositely. Thus, a single part can be used for the clutch bearing of the present invention wherein drive is achieved in one direction and freewheeling is created in the opposite direction. While particular embodiments of this invention have been shown in the drawings and described above, it will be apparent, that many changes may be made in the form, arrangement and positioning of the various elements of the combination. In consideration thereof it should be understood that preferred embodiments of this invention disclosed herein are intended to be illustrative only and not intended to limit the scope of the invention.

The present invention provides an improved drive mechanism for reciprocating engines primary adapted for converting reciprocating motion of a piston within a cylinder to rotary motion which includes a piston and piston leg assembly which moves solely axially within the piston chamber with two rack gear members secured to the sides of the piston leg. A power driveshaft and an idler driveshaft are positioned on opposite sides of the movable piston leg and include a plurality of gears thereon positioned adjacent to each piston chamber for receiving driving movement therefrom. This longitudinal movement of the piston is converted to rotational movement of the shaft through the rack gears and power and idler gears which are connected to the power driveshaft and the idler driveshaft through a unique configuration including clutch bearings adapted to convey power driving movement responsive to movement of the pistons toward the crankshaft and to be freewheeling during movement of the pistons away from the crankshaft. The power driveshaft and idler driveshaft are mounted parallel with respect to one another and are interconnected by drive gears. Power output is provided at the power driveshaft rather than at the crankshaft in a more conventional reciprocating piston engine configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is the U.S. National Phase application of PCT/FR2009/052341 filed Nov. 30, 2009, which claims priority to French Application No. 0858167 filed Dec. 1, 2008, which applications are incorporated herein by reference and made a part hereof. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates to the field of treating materials derived from recycling motor vehicles. [0004] 2. Description of the Related Art [0005] Numerous motor vehicle parts are made out of plastics materials. At the end of life, such parts can be recovered and recycled so as to be used in other applications. [0006] For this purpose, a first step consists in sorting scrap vehicle parts as a function of their respective main materials. Thereafter, the parts are shredded, and non-ferrous metals are recovered by magnetization and by eddy currents. The remaining shredded material is referred to as auto shredder residue (ASR) or “fluff”. This fluff generally contains a mixture of various plastics materials, such as, for example, polypropylene (PP) and polyethylene (PE), together with various other materials such as wood, various foams, fabrics, etc. [0007] In order to be suitable for recycling and reuse, it is preferable for the fluff to be as pure as possible, i.e., for it to contain a large majority of a single type of plastics material. The presence of several plastics materials in the residue generally gives rise to physical and mechanical properties that are not as good as those of a material that is almost pure. [0008] In particular, the presence of polyethylene mixed in the polypropylene spoils the mechanical properties of polypropylene such as impact strength or breaking elongation. [0009] That is why it is necessary to have an additional step of treating the fluff in order to reduce the quantity of polyethylene relative to the quantity of polypropylene. It is generally desirable to obtain a mixture having less than 5% polyethylene. [0010] At present, such treatment is relatively complex and expensive to implement since it consists either in setting up high-performance sorting systems seeking to separate the polyethylene from the polypropylene, or else in diluting mixtures of polypropylene and polyethylene with virgin polypropylene, which is expensive. SUMMARY OF THE INVENTION [0011] A particular object of the invention is to provide a method of treating a material derived from recycling that comprises a mixture of polypropylene and polyethylene, which method is simpler and less expensive than known methods. [0012] To this end, one embodiment of the invention provides a method of treating a material derived from recovery and shredding, the material comprising a mixture of polypropylene and of polyethylene, wherein the material is mixed with 1% to 5% by weight of copolymer of the ethylene-α-olefin type. [0013] Tests have shown that adding a small amount (lying in the range 1% to 5%) of ethylene-α-olefin type copolymer to a mixture of polypropylene and polyethylene makes it possible to obtain a material having mechanical performance that is substantially identical to that of virgin polypropylene. The copolymer has a compatibilizing effect on the mixture of polypropylene and polyethylene. [0014] This treatment operation is found to be particularly simple and inexpensive compared with treatment methods known in the state of the art, and it makes it possible to obtain a material that has practically the same properties as a virgin polypropylene. Furthermore, the method of the invention enables materials to be treated in which the polyethylene content may be as high as 30%. [0015] The quantity of copolymer to be added to the mixture has no need to be very great, and it may be limited to 5%. [0016] Because the material is derived from recovery and shredding, it includes a small proportion of in situ elastomer derived from the polypropylene being polymerized while it was being synthesized. These traces of elastomer in the mixture facilitate the compatibilizing effect of the copolymer, even when only a small quantity is mixed in. [0017] If the mixture of polypropylene and polyethylene were to be made from a virgin polypropylene, i.e., a polypropylene not derived from recovery and shredding, then a larger quantity of copolymer (e.g., greater than 20%) would be necessary in order to restore to the polypropylene the mechanical properties that it lost on being mixed with polyethylene. In the absence of traces of elastomer resulting from polymerization of the polypropylene reduces the compatibilizing effect of the copolymer. [0018] Thus, this method of treating a mixture of polypropylene and polyethylene is particularly adapted to treating materials derived from recovery and shredding, since the quantity of ethylene-α-olefin type copolymer that needs to be added under such circumstances is relatively small. [0019] Once the material derived from shredding has been treated by the method of the invention, the product that results from the treatment method may be used for fabricating various parts, such as new bumpers, or other applications in which the mechanical performance of the material plays an important role. [0020] A method of the invention may also include one or more of the following characteristics. [0021] The material is derived from auto shredding residue or from any other source of polypropylene polluted with polyethylene, such as electrical and electronic equipment waste, for example. As mentioned in the introduction, numerous motor vehicle parts may be recycled. For example, bodywork parts such as bumpers and fuel tanks are made from the most part out of polypropylene and polyethylene, and the result of shredding them to provide pieces having an area of a few square centimeters can be treated by the method of the invention. [0022] The copolymer of ethylene-α-olefin type is selected from any of the items of the group constituted by ethylene-octene and ethylene-butene. These two materials are particularly well adapted to implementing the method for compatibilizing a mixture of polypropylene and polyethylene. [0023] The polypropylene is a homopolymer or copolymer polypropylene. [0024] The polyethylene is a low, medium, or high density polyethylene. [0025] The invention also provides a motor vehicle part made of a material comprising: polypropylene; polyethylene; and 1% to 5% by weight of copolymer of ethylene-α-olefin type. [0026] In other words, the invention provides a motor vehicle part made of a material derived from the treatment method of the invention. [0027] A motor vehicle part of the invention may advantageously be made with polypropylene and polyethylene derived from auto shredder residue. [0028] Furthermore, the motor vehicle part may be a bodywork part. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0029] The invention can be better understood on reading the following description given solely by way of example. [0030] Polypropylene is a material that is commonly used for fabricating motor vehicle parts. This material is particularly advantageous because its mechanical strength characteristics are high. For a conventional virgin polypropylene, breaking stress is of the order of 19 megapascals (MPa) and breaking deformation is of the order of 500%. [0031] When the same breaking and elongation strength tests are performed with polypropylene derived from auto shredding residue, i.e., from polypropylene mixed with a large quantity of polyethylene, it is found that breaking stress is about 16 MPa and breaking deformation is about 115%. [0032] The presence of polyethylene in a polypropylene, in particular in auto shredding residue, therefore considerably degrades the mechanical properties of the polypropylene. [0033] The invention proposes mixing in the range 1% to 5% of copolymer of the ethylene-α-olefin type in a material derived from auto shredding residue that comprises a mixture of polypropylene and polyethylene in order to obtain a material having mechanical properties that are close to those of a virgin polypropylene. [0034] The copolymer of the ethylene-α-olefin type that is used may be ethylene-octene or ethylene-butene, for example. [0035] Tests have been performed by mixing auto shredding residue with 5% of ethylene-α-olefin. The results of those tests show that the material derived from that treatment possesses breaking stress of about 20 MPa and breaking deformation of about 600%. [0036] Consequently, it can be seen that by adding 5% of copolymer in a mixture derived from auto shredding residue, a material is obtained having mechanical properties that are substantially identical to those of a virgin polypropylene, or indeed better. [0037] Thus, the treatment method of the invention makes it possible to recycle effectively and in simple manner polypropylene that is derived from auto shredding residue, shredding residue derived from electrical and electronic equipment waste (EEEW), or from any other source of polypropylene having mechanical properties that are degraded by the polyethylene mixed therewith. [0038] The invention is described above with reference to the automobile industry field. Naturally, the invention is applicable to other technical fields in which there is a need to recycle parts made of polypropylene and of polyethylene for applications that require mechanical performance similar to that of a virgin polypropylene. [0039] While the process and product herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise process and product, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

A method of treating a material derived from recovery and shredding, the material comprising a mixture of polypropylene and polyethylene, wherein the material is mixed with 1% to 5% by weight of copolymer of ethylene-α-olefin type.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. provisional application 61/090,118, which was filed on Aug. 19, 2008, and which is incorporated herein in its entirety by reference. FIELD [0002] The present invention relates to methods of inspection usable, for example, in the manufacture of devices by lithographic techniques and to methods of manufacturing devices using lithographic techniques. BACKGROUND [0003] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g., comprising part of, one, or several dies) on a substrate (e.g., a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate. [0004] In order to monitor the lithographic process, it is necessary to measure parameters of the patterned substrate, for example the overlay error between successive layers formed in or on it. There are various techniques for making measurements of the microscopic structures formed in lithographic processes, including the use of scanning electron microscopes and various specialized tools. One form of specialized inspection tool is a scatterometer in which a beam of radiation is directed onto a target on the surface of the substrate, and properties of the scattered or reflected beam are measured. By comparing the properties of the beam before and after it has been reflected or scattered by the substrate, the properties of the substrate can be determined. This can be done, for example, by comparing the reflected beam with data stored in a library of known measurements associated with known substrate properties. Two main types of scatterometer are known. Spectroscopic scatterometers direct a broadband radiation beam onto the substrate, and measure the spectrum (intensity as a function of wavelength) of the radiation scattered into a particular narrow angular range. Angularly resolved scatterometers use a monochromatic radiation beam and measure the intensity of the scattered radiation as a function of angle. [0005] Measurement of the overlay error is generally achieved by etching specific targets in an unused area of the substrate, known as a scribelane. The overlay error of all the relevant features is then assumed to be the same as the measured overlay error of the target in a nearby scribelane. However, the true overlay error of a particular feature may be affected by a number of different factors, and thus may not be the same as the overlay error of the designated target in the scribelane. In particular, overlay targets may have a different response to changes in illumination mode, polarization and aberrations (static and dynamic) from the feature to measured. Additionally the scribelane may not be very close to the particular feature concerned and thus some interpolation between neighboring targets may be necessary. Furthermore, the process dependencies used of the feature and the target may be different due to different geometry and surrounding structures. SUMMARY [0006] It is desirable to provide a method which more accurately determines the overlay error of a feature of interest based on measuring overlay from dedicated targets. [0007] According to an embodiment of the invention, there is provided a method of determining overlay error of a feature exposed on a substrate by a lithographic apparatus comprising the following steps. Measuring the overlay error of a target. Determining the overlay error of the feature based on the overlay error of the target and a model of lithographic apparatus metrology. [0008] According to another embodiment of the invention, there is provided a method of determining the overlay error of a feature exposed on a substrate by a lithographic apparatus comprising the following steps. Measuring the overlay error of a target. Determining the overlay error of the feature based on the overlay error of the target and a model, the model modeling the relative overlay error at different positions on the substrate based on inputs from a substrate and/or the lithographic apparatus metrology. [0009] According to a further embodiment of the invention, there is provided a method of determining the overlay error of a feature on a substrate comprising the following steps. Measuring the overlay error of a target. Determining the overlay error of the feature based on the overlay error of the target and a model, the model modeling the characteristics of the feature. [0010] According to a still further embodiment of the invention, there is provided a lithographic apparatus to form a pattern on a substrate that is configured to determine the overlay error using one or more of the methods as described above. [0011] Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. It is noted that the invention is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES [0012] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the relevant art(s) to make and use the invention. [0013] FIGS. 1A and 1B respectively depict reflective and transmissive lithographic apparatuses. [0014] FIG. 2 depicts a lithographic cell or cluster. [0015] FIG. 3 depicts an exemplary scatterometer. [0016] FIG. 4 depicts another exemplary scatterometer. [0017] FIG. 5 is a flow chart depicting a method. [0018] The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number. DETAILED DESCRIPTION [0019] This specification discloses one or more embodiments that incorporate the features of this invention. The disclosed embodiment(s) merely exemplify the invention. The scope of the invention is not limited to the disclosed embodiment(s). The invention is defined by the claims appended hereto. [0020] The embodiment(s) described, and references in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. [0021] Embodiments of the invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the invention may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Further, firmware, software, routines, instructions may be described herein as performing certain actions. However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc. [0022] FIGS. 1A and 1B schematically depict lithographic apparatus 100 and lithographic apparatus 100 ′, respectively. Lithographic apparatus 100 and lithographic apparatus 100 ′ each include: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g., DUV or EUV radiation); a support structure (e.g., a mask table) MT configured to support a patterning device (e.g., a mask, a reticle, or a dynamic patterning device) MA and connected to a first positioner PM configured to accurately position the patterning device MA; and a substrate table (e.g., a wafer table) WT configured to hold a substrate (e.g., a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate W. Lithographic apparatuses 100 and 100 ′ also have a projection system PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion (e.g., comprising one or more dies) C of the substrate W. In lithographic apparatus 100 the patterning device MA and the projection system PS is reflective, and in lithographic apparatus 100 ′ the patterning device MA and the projection system PS is transmissive. [0023] The illumination system IL may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping, or controlling the radiation B. [0024] The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA, the design of the lithographic apparatuses 100 and 100 ′, and other conditions, such as for example whether or not the patterning device MA is held in a vacuum environment. The support structure MT may use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device MA. The support structure MT may be a frame or a table, for example, which may be fixed or movable, as required. The support structure MT may ensure that the patterning device is at a desired position, for example with respect to the projection system PS. [0025] The term “patterning device” MA should be broadly interpreted as referring to any device that may be used to impart a radiation beam B with a pattern in its cross-section, such as to create a pattern in the target portion C of the substrate W. The pattern imparted to the radiation beam B may correspond to a particular functional layer in a device being created in the target portion C, such as an integrated circuit. [0026] The patterning device MA may be transmissive (as in lithographic apparatus 100 ′ of FIG. 1B ) or reflective (as in lithographic apparatus 100 of FIG. 1A ). Examples of patterning devices MA include reticles, masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase shift, and attenuated phase shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which may be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in the radiation beam B which is reflected by the mirror matrix. [0027] The term “projection system” PS may encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors, such as the use of an immersion liquid or the use of a vacuum. A vacuum environment may be used for EUV or electron beam radiation since other gases may absorb too much radiation or electrons. A vacuum environment may therefore be provided to the whole beam path with the aid of a vacuum wall and vacuum pumps. [0028] Lithographic apparatus 100 and/or lithographic apparatus 100 ′ may be of a type having two (dual stage) or more substrate tables (and/or two or more mask tables) WT. In such “multiple stage” machines the additional substrate tables WT may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other substrate tables WT are being used for exposure. [0029] Referring to FIGS. 1A and 1B , the illuminator IL receives a radiation beam from a radiation source SO. The source SO and the lithographic apparatuses 100 , 100 ′ may be separate entities, for example when the source SO is an excimer laser. In such cases, the source SO is not considered to form part of the lithographic apparatuses 100 or 100 ′, and the radiation beam B passes from the source SO to the illuminator IL with the aid of a beam delivery system BD ( FIG. 1B ) comprising, for example, suitable directing mirrors and/or a beam expander. In other cases, the source SO may be an integral part of the lithographic apparatuses 100 , 100 ′—for example when the source SO is a mercury lamp. [0030] The source SO and the illuminator IL, together with the beam delivery system BD, if required, may be referred to as a radiation system. [0031] The illuminator IL may comprise an adjuster AD ( FIG. 1B ) for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution in a pupil plane of the illuminator may be adjusted. In addition, the illuminator IL may comprise various other components ( FIG. 1B ), such as an integrator IN and a condenser CO. The illuminator IL may be used to condition the radiation beam B, to have a desired uniformity and intensity distribution in its cross section. [0032] Referring to FIG. 1A , the radiation beam B is incident on the patterning device (e.g., mask) MA, which is held on the support structure (e.g., mask table) MT, and is patterned by the patterning device MA. In lithographic apparatus 100 , the radiation beam B is reflected from the patterning device (e.g., mask) MA. After being reflected from the patterning device (e.g., mask) MA, the radiation beam B passes through the projection system PS, which focuses the radiation beam B onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF 2 (e.g., an interferometric device, linear encoder or capacitive sensor), the substrate table WT may be moved accurately, e.g., so as to position different target portions C in the path of the radiation beam B. Similarly, the first positioner PM and another position sensor IF 1 may be used to accurately position the patterning device (e.g., mask) MA with respect to the path of the radiation beam B. Patterning device (e.g., mask) MA and substrate W may be aligned using mask alignment marks M 1 , M 2 and substrate alignment marks P 1 , P 2 . [0033] Referring to FIG. 1B , the radiation beam B is incident on the patterning device (e.g., mask MA), which is held on the support structure (e.g., mask table MT), and is patterned by the patterning device. Having traversed the mask MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF (e.g., an interferometric device, linear encoder or capacitive sensor), the substrate table WT can be moved accurately, e.g., so as to position different target portions C in the path of the radiation beam B. Similarly, the first positioner PM and another position sensor (which is not explicitly depicted in FIG. 1B ) can be used to accurately position the mask MA with respect to the path of the radiation beam B, e.g., after mechanical retrieval from a mask library, or during a scan. [0034] In general, movement of the mask table MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the mask table MT may be connected to a short-stroke actuator only, or may be fixed. Mask MA and substrate W may be aligned using mask alignment marks M 1 , M 2 and substrate alignment marks P 1 , P 2 . Although the substrate alignment marks as illustrated occupy dedicated target portions, they may be located in spaces between target portions (known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks may be located between the dies. [0035] The lithographic apparatuses 100 and 100 ′ may be used in at least one of the following modes: 1. In step mode, the support structure (e.g., mask table) MT and the substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam B is projected onto a target portion C at one time (i.e., a single static exposure). The substrate table WT is then shifted in the X and/or Y direction so that a different target portion C may be exposed. 2. In scan mode, the support structure (e.g., mask table) MT and the substrate table [0038] WT are scanned synchronously while a pattern imparted to the radiation beam B is projected onto a target portion C (i.e., a single dynamic exposure). The velocity and direction of the substrate table WT relative to the support structure (e.g., mask table) MT may be determined by the (de-)magnification and image reversal characteristics of the projection system PS. 3. In another mode, the support structure (e.g., mask table) MT is kept substantially stationary holding a programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the radiation beam B is projected onto a target portion C. A pulsed radiation source SO may be employed and the programmable patterning device is updated as required after each movement of the substrate table WT or in between successive radiation pulses during a scan. This mode of operation may be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as referred to herein. [0040] Combinations and/or variations on the described modes of use or entirely different modes of use may also be employed. [0041] In a further embodiment, lithographic apparatus 100 includes an extreme ultraviolet (EUV) source, which is configured to generate a beam of EUV radiation for EUV lithography. In general, the EUV source is configured in a radiation system, and a corresponding illumination system is configured to condition the EUV radiation beam of the EUV source. [0042] Combinations and/or variations on the above described modes of use or entirely different modes of use may also be employed. [0043] As shown in FIG. 2 , the lithographic apparatus LA forms part of a lithographic cell LC, also sometimes referred to a lithocell or cluster, which also includes apparatus to perform pre- and post-exposure processes on a substrate. IN one example, a lithocell or cluster may include spin coaters SC to deposit resist layers, developers DE to develop exposed resist, chill plates CH and bake plates BK. [0044] A substrate handler, or robot, RO picks up substrates from input/output ports I/O 1 , I/O 2 , moves them between the different process apparatus and delivers then to the loading bay LB of the lithographic apparatus. These devices, which are often collectively referred to as the track, are under the control of a track control unit TCU, which is itself controlled by the supervisory control system SCS, which also controls the lithographic apparatus via lithography control unit LACU. Thus, the different apparatus can be operated to maximize throughput and processing efficiency. [0045] In one example, it is desirable to inspect exposed substrates to measure properties such as overlay errors between subsequent layers, line thicknesses, critical dimensions (CD), etc. If errors are detected, adjustments may be made to exposures of subsequent substrates, especially if the inspection can be done soon and fast enough that other substrates of the same batch are still to be exposed. Also, already exposed substrates may be stripped and reworked, e.g., to improve yield, or discarded, thereby avoiding performing exposures on substrates that are known to be faulty. In a case where only some target portions of a substrate are faulty, further exposures can be performed only on those target portions which are good. [0046] An inspection apparatus is used to determine the properties of the substrates, and in particular, how the properties of different substrates or different layers of the same substrate vary from layer to layer. The inspection apparatus may be integrated into the lithographic apparatus LA or the lithocell LC or may be a stand-alone device. To enable most rapid measurements, it is desirable that the inspection apparatus measure properties in the exposed resist layer immediately after the exposure. However, the latent image in the resist may have a very low contrast, i.e., there is only a very small difference in refractive index between the parts of the resist which have been exposed to radiation and those which have not, and not all inspection apparatus have sufficient sensitivity to make useful measurements of the latent image. Therefore, measurements may be taken after the post-exposure bake step (PEB), which is customarily the first step carried out on exposed substrates and increases the contrast between exposed and unexposed parts of the resist. At this stage, the image in the resist may be referred to as semi-latent. It is also possible to make measurements of the developed resist image, at which point either the exposed or unexposed parts of the resist have been removed, or after a pattern transfer step, such as etching. The latter possibility limits the possibilities for rework of faulty substrates, but may still provide useful information. [0047] FIG. 3 depicts a scatterometer SM 1 according to an embodiment of the present invention. It comprises a broadband (e.g., white light) radiation projector 2 that projects radiation onto a substrate W. The reflected radiation is passed to a spectrometer detector 4 , which measures a spectrum 10 (e.g., intensity as a function of wavelength) of the specular reflected radiation. From this data, the structure or profile giving rise to the detected spectrum may be reconstructed by processing unit PU, e.g., by Rigorous Coupled Wave Analysis and non-linear regression or by comparison with a library of simulated spectra, as shown at the bottom of FIG. 3 . In one example, for the reconstruction the general form of the structure is known and some parameters are assumed from knowledge of the process by which the structure was made, leaving only a few parameters of the structure to be determined from the scatterometry data. Such a scatterometer may be configured as, for example, a normal-incidence scatterometer or an oblique-incidence scatterometer. [0048] FIG. 4 shows another scatterometer SM 2 according to another embodiment of the present invention. In this device, the radiation emitted by radiation source 2 is focused using lens system 12 through interference filter 13 and polarizer 17 , reflected by partially reflected surface 16 , and is focused onto substrate W via a microscope objective lens 15 , which has a high numerical aperture (NA), for example at least about 0.9 or at least about 0.95. In some examples, immersion scatterometers may even have lenses with numerical apertures over about 1. The reflected radiation then transmits through partially reflective surface 16 into a detector 18 in order to have the scatter spectrum detected. The detector may be located in the back-projected pupil plane 11 , which is at the focal length of the lens system 15 , however the pupil plane may instead be re-imaged with auxiliary optics (not shown) onto the detector 18 . For example, the pupil plane is the plane in which the radial position of radiation defines the angle of incidence and the angular position defines azimuth angle of the radiation. In one example, the detector is a two-dimensional detector so that a two-dimensional angular scatter spectrum of a substrate target 30 can be measured. The detector 18 may be, for example, an array of CCD or CMOS sensors, and may use an integration time of, for example, about 40 milliseconds per frame. [0049] Additionally, or alternative, a reference beam is often used, for example, to measure the intensity of the incident radiation. To do this, when the radiation beam is incident on the beam splitter 16 , part of it is transmitted through the beam splitter as a reference beam towards a reference mirror 14 . The reference beam is then projected onto a different part of the same detector 18 . [0050] Additionally, or alternatively, a set of interference filters 13 is available to select a wavelength of interest in the range of, for example, about 405-790 nm or even lower, such as about 200-300 nm. The interference filter may be tunable rather than comprising a set of different filters. A grating could be used instead of interference filters. [0051] The detector 18 may measure the intensity of scattered light at a single wavelength (or narrow wavelength range), the intensity separately at multiple wavelengths or integrated over a wavelength range. Furthermore, the detector may separately measure the intensity of transverse magnetic- and transverse electric-polarized light and/or the phase difference between the transverse magnetic- and transverse electric-polarized light. [0052] In one example, using a broadband light source (i.e., one with a wide range of light frequencies or wavelengths—and therefore of colors) is possible, which gives a large etendue, allowing the mixing of multiple wavelengths. The plurality of wavelengths in the broadband each has a bandwidth of *8 and a spacing of at least 2*8 (i.e., twice the bandwidth). Several “sources” of radiation can be different portions of an extended radiation source which have been split using fiber bundles. In this way, angle resolved scatter spectra can be measured at multiple wavelengths in parallel. A 3-D spectrum (wavelength and two different angles) can be measured, which contains more information than a 2-D spectrum. This allows more information to be measured which increases metrology process robustness. This is described in more detail in EP1,628,164A, which is incorporated by reference herein in its entirety. [0053] In one example, the target 30 on substrate W may be a grating, which is printed such that after development, the bars are formed of solid resist lines. The bars may alternatively be etched into the substrate. This pattern is sensitive to chromatic aberrations in the lithographic projection apparatus, particularly the projection system PL, and illumination symmetry and the presence of such aberrations will manifest themselves in a variation in the printed grating. Accordingly, the scatterometry data of the printed gratings is used to reconstruct the gratings. The parameters of the grating, such as line widths and shapes, may be input to the reconstruction process, performed by processing unit PU, from knowledge of the printing step and/or other scatterometry processes. [0054] FIG. 5 shows a flowchart depicting a method to measure an overlay error. First, an overlay error of a substrate may be measured. From this value, the overlay error of a feature is calculated. However, a number of factors may mean that the overlay error of a feature is not the same as the overlay error of a target. [0055] Firstly, the process of exposing the substrate, including both the feature and the target may itself yield variations in the overlay error between the feature and the target, due to different responses to the illumination mode, polarization and aberrations. This may include, for example, different inputs from the mask MA. [0056] In step S 1 , an overlay error of a target is measured. [0057] In step S 2 , a model is used to simulate any relative difference between the overlay error of a feature and the overlay error of the target. In various examples, the model can be generated either by using lithographic apparatus metrology, such as by taking aberration measurements and accounting for the illumination mode and polarization state, or alternatively by using a test substrate to measure the relative differences due to these factors. [0058] Secondly, the different locations of the feature and the target may also yield variations in the overlay error between the feature and the target. In step S 3 , a model is again used to simulate any relative differences due to the location of the feature and target. Again, in various examples, this model can be generated either by using metrology data from the lithographic apparatus and the mask or by using a test substrate to measure the relative differences due to these factors. [0059] Thirdly, differences between the feature structure and characteristics and the target structure and characteristics could result in different overlay errors due to the processing of the substrate, such as etching, deposition or polishing. These may be assessed using theoretical results, prior experience and/or databases. Alternatively, to assess the different effects, the overlay error for a sample feature can be measured and compared to the overlay error for a target. In step S 4 , this is then used to model the difference in overlay error calculations between the feature and the target due to product structure and characteristics. [0060] If there are multiple features of interest on a substrate, different models may be used for each feature to account for the different locations and different structures used. Furthermore the overlay error may vary over time and this factor may be included in the model(s). [0061] It is to be appreciated that to ensure the continued accuracy of this method over time, test substrates may be measured at regular and frequent intervals so that the models account for any changes in the apparatus and process over time. [0062] Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid-crystal displays (LCDs), thin film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” herein may be considered as synonymous with the more general terms “substrate” or “target portion”, respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology tool and/or an inspection tool. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers. [0063] Although specific reference may have been made above to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention may be used in other applications, for example imprint lithography, and where the context allows, is not limited to optical lithography. In imprint lithography a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device may be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured. [0064] In the embodiments described herein, the terms “lens” and “lens element,” where the context allows, may refer to any one or combination of various types of optical components, comprising refractive, reflective, magnetic, electromagnetic and electrostatic optical components. [0065] Further, the terms “radiation” and “beam” used herein encompass all types of electromagnetic radiation, comprising ultraviolet (UV) radiation (e.g., having a wavelength λ of 365, 248, 193, 157 or 126 nm), extreme ultra-violet (EUV or soft X-ray) radiation (e.g., having a wavelength in the range of 5-20 nm, e.g., 13.5 nm), or hard X-ray working at less than 5 nm, as well as particle beams, such as ion beams or electron beams. Generally, radiation having wavelengths between about 780-3000 nm (or larger) is considered IR radiation. UV refers to radiation with wavelengths of approximately 100-400 nm. Within lithography, it is usually also applied to the wavelengths, which can be produced by a mercury discharge lamp: G-line 436 nm; H-line 405 nm; and/or I-line 365 nm. Vacuum UV, or VUV (i.e., UV absorbed by air), refers to radiation having a wavelength of approximately 100-200 nm. Deep UV (DUV) generally refers to radiation having wavelengths ranging from 126 nm to 428 nm, and in an embodiment, an excimer laser can generate DUV radiation used within lithographic apparatus. It should be appreciated that radiation having a wavelength in the range of, for example, 5-20 nm relates to radiation with a certain wavelength band, of which at least part is in the range of 5-20 nm. [0066] While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. For example, the invention may take the form of a computer program containing one or more sequences of machine-readable instructions describing a method as disclosed above, or a data storage medium (e.g., semiconductor memory, magnetic or optical disk) having such a computer program stored therein. CONCLUSION [0067] It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventor(s), and thus, are not intended to limit the present invention and the appended claims in any way. [0068] The present invention has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. [0069] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present invention. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance. [0070] The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

The overlay error of a target in a scribelane is measured. The overlay error of the required feature in the chip area may differ from this due to, for example, different responses to the exposure process. A model is used to simulate these differences and thus a more accurate measurement of the overlay error of the feature determined.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method for an organic optoelectronic thin film, and more particularly to a manufacturing method for an organic optoelectronic thin film that adds a polymer oxide to a semiconductor layer, and transfers the semiconductor layer to a conductive polymer layer. 2. Description of the Related Art In the past, organic solar cells were generally manufactured by a solution manufacturing process. In the solution manufacturing process, a layer of solvent is coated onto a substrate first, and then the solvent is coated with poly(3-hexylthiophene) (P3HT) and phenyl C61-butyric acid methyl ester (PCBM). In the manufacturing process, the solvent will dissolve with P3HT and PCBM to cause various problems. To overcome the aforementioned problem of dissolving solvents during the solution manufacturing process, R.O.C. Pat. No. I318334 by Kumar, A. and Whitesides, G. M. et al. as well as M. L. Chabinyc, et al. disclosed a micro-contact printing technology in 2004, and such technology is illustrated in FIGS. 1A˜1D . In FIGS. 1A˜1D , the procedure of the micro-contact printing technology are demonstrated. In FIG. 1A , a silicon substrate 11 , whose surface is plated with a gold thin film 12 is shown. In FIG. 1B , a design pattern etched onto a surface is provided, and a layer of ink molecules 14 such as alkanethiol is formed on a poly(dimethylsiloxane) (PDMS) print mold 13 . The alkanethiol solution is poured onto the print mold 13 to ink the PDMS print mold 13 . In FIG. 1C , the gold plated silicon substrate 11 is in contact with the inked PDMS print mold 13 , the ink molecules 14 of alkanethiol on the print mold 13 are combined with gold atoms on the substrate 11 through the covalent bonding to form a self assembled monolayer. In FIG. 1D , after the PDMS print mold is removed, a layer with the design pattern is printed onto the gold plated silicon substrate 11 by the self assembled monolayer 15 with the covalent bonding of alkanethiol. In the aforementioned manufacturing process of the PDMS print mold, the manufacturing process of the PDMS print mold is too complicated and time consuming. In addition, when the PDMS print mold is processed appropriately during the use of the PDMS is used, the number of times of using the PDMS print mold is also limited. Therefore, it is the main subject for the present invention to simplify the solar cell manufacturing process and overcome the problem of dissolving solvents and using the PDMS print mold. SUMMARY OF THE INVENTION In view of the aforementioned problem, the present invention provides a manufacturing method for organic optoelectronic thin film, and the manufacturing method adds PEG into a semiconductor layer, and the semiconductor layer is transferred to a conductive polymer layer to solve the problems of the conventional solution manufacturing process that the solvents are dissolved by using the PDMS print mold of the micro-contact printing technology. Therefore, it is a primary objective of the present invention to overcome the aforementioned shortcomings of the prior art by providing a manufacturing method for an organic optoelectronic thin film, and the manufacturing method comprises the steps of: providing a substrate and a first electrode; forming a semiconductor layer on the substrate, and the semiconductor layer including a polyethylene glycol; coating a conductive polymer layer on the first electrode; placing the substrate and the semiconductor layer on the conductive polymer layer, and attaching the semiconductor layer with the conductive polymer layer; removing the substrate; and evaporating a second electrode on the semiconductor layer to form the organic optoelectronic thin film; wherein a first adhesion is generated between the semiconductor layer and the substrate, and a second adhesion is generated between the semiconductor layer and the conductive polymer layer, and the second adhesion is greater than the first adhesion, such that when the substrate is removed, the semiconductor layer is still attached onto the conductive polymer layer. In summation, the manufacturing method for an organic optoelectronic thin film in accordance with the present invention has one or more of the following advantages: (1) The invention simplifies the manufacturing process, and saves the trouble of manufacturing the PDMS print mold to achieve the same transfer effect. (2) The invention uses a roll-to-roll manufacturing process to coat the solution onto the flexible substrate quickly and easily, so as to further simplify the manufacturing process and reduce the manufacturing time for an easier entry of a mass production. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A˜1D show a procedure of a micro-contact printing technology; FIGS. 2A˜2F show a procedure of a manufacturing method of a solar cell in accordance with a preferred embodiment of the present invention; FIG. 3 is a graph of voltage versus current density of a solar cell manufacturing by a transfer method and a coating method of the semiconductor layer containing PEG and a coating method of a semiconductor layer of a solar cell without containing any PEG at 100 mW/cm 2 and with a standard solar energy simulated light of AM 1.5 G; and FIG. 4 is a schematic view of a roll-to-roll manufacturing process of a solar cell in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The foregoing and other objectives, characteristics and advantages of the present invention will become apparent by the detailed description of a preferred embodiment as follows. With reference to FIGS. 2A˜2F for the procedure of a manufacturing method of a solar cell 2 in accordance with a preferred embodiment of the present invention, the manufacture of the solar cell 2 as shown in FIG. 2A firstly provides a substrate 21 . The substrate 21 is one selected from the group consisting of a glass substrate, a polymer plastic substrate and an electronic circuit substrate, and the electronic circuit substrate is a silicon substrate. The polymer plastic substrate is made of a material selected from the group consisting of polyethylene teraphthalate (PET) and polycarbonate. In this preferred embodiment, the substrate 21 is, for example, the silicon substrate. Secondly, a p-type semiconductor material and an n-type semiconductor material are used for producing a solution, and a poly(ethylene glycol) (PEG) of different molecular weights is added into the solution. Finally, the substrate 21 is rinsed, and a spin-coating or deposition method is used for forming the solution onto the substrate 21 to form a semiconductor layer 22 . The p-type semiconductor material is one selected from the group consisting of polythiophene, polyfluorene, polyphenylenevinylene, polythiophene derivative, polyfluorene derivative, polyphenylenevinylene derivative, conjugated oligomer and small molecule, and the polythiophene derivative is poly(3-hexylthiophene) (P3HT); the polyfluorene derivative is poly(dioctylfluorene); the polyphenylenevinylene derivative is poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene]; the conjugated oligomer is sexithiophene, and the small molecule is one selected from the group consisting of pentacene, tetracene, hexabenzcoronene, phthalocyanine, porphyrines, pentacene derivative, tetracene derivative, hexabenzcoronene derivative, phthalocyanine derivative, and porphyrin compound derivative. The n-type semiconductor material is one selected from the group consisting of C60, C60 derivative, C70, C70 derivative, carbon nanotube, carbon nanotube derivative, 3,4,9,10-perylene tetracarboxylic-bis-benzimidazole (PTCBI), N,N′-dimethyl-3,4,9,10-perylenetetracarboxylic acid diimide (Me-PTCDI), 3,4,9,10-perylene tetracarboxylic-bis-benzimidazole (PTCBI) derivative, N,N′-dimethyl-3,4,9,10-tetracarboxylic acid dimide derivative, polymer and semiconductor nanoparticle; the C60 derivative is phenyl C61-butyric acid methyl ester (PCBM); the polymer is one selected from the group consisting of poly(2,5,2′,5′-tetrahexyloxy-7,8′-dicyano-di-p-phenylenevinylene) (CN-PPV) and poly(9,9′-dioctylfluorene-co-benzothiadiazole (F8BT); the carbon nanotube is a multi-walled carbon nanotube or a single-walled carbon nanotube, and the cross-sectional diameter of the carbon nanotube is smaller than 100 nm; and the semiconductor nanoparticle is one selected from the group consisting of titanium dioxide, cadmium selenide and cadmium sulfide. In this preferred embodiment, the p-type semiconductor material is preferably P3HT, and the n-type semiconductor material is preferably PCBM, and the ratio by weight of P3HT and PCBM is 1:1, and they are mixed into a solution with a percentage by weight of 2%. In the meantime, the PEG of different molecular weights and P3HT have a specific ratio by weight. For example, the weight ratio of PEG and P3HT is 1:5˜1:5, and preferably 1:20. After the semiconductor layer 22 is processed by a solvent annealing process for at least 2 hours, the semiconductor layer 22 is processed by a thermal annealing process at 110° C. for 15 minutes. In FIG. 2B , a patterned first electrode 23 is provided, and the first electrode 23 is a transparent conductor or a semi-transparent conductor; the transparent conductor is made of indium tin oxide (ITO) or indium zinc oxide; the semi-transparent conductor is a metal thin film, and the metal thin film is made of a material selected from the group consisting of silver, aluminum, titanium, nickel, copper, gold, and chromium. After the first electrode 23 is rinsed, a conductive polymer layer 24 is coated onto the first electrode 23 by a spin-coating process, and then the conductive polymer layer 24 and the first electrode 23 are baked dry at 120° C. for 60 minutes. The electrically conductive polymer of the conductive polymer layer 24 is made of a material selected from the group consisting of 3,4-polyethylenedioxythiophene-polystyrenesulfonate (PEDOT:PSS), polyaniline, polypyrrole and polyacetylene. The additive is a surfactant, and the surfactant is poly(oxyethylene tridecyl ether). In this preferred embodiment, the conductive polymer layer 24 is preferably made of PEDOT: PSS. In FIG. 2C , a transfer procedure takes place. Before the transfer, the conductive polymer layer 24 is heated at 110° C. for 5 minutes, and then the substrate 21 and the semiconductor layer 22 are placed on the conductive polymer layer 24 , and the semiconductor layer 22 is attached with the conductive polymer layer 24 . After the attachment, a uniform pressure is exerted onto a junction of the semiconductor layer 22 and the conductive polymer layer 24 as shown in FIG. 2D . A first adhesion is generated between the semiconductor layer 22 containing PEG of different molecular weights and the substrate 21 and a second adhesion is generated between the semiconductor layer 22 containing PEG of different molecular weights and the conductive polymer layer 24 . Since the PEG is deposited at a position near the substrate 21 or the PEG is distributed on the contact surface with the substrate 21 , therefore the adhesion between the semiconductor layer 22 and the substrate 21 is weaker than the adhesion between the semiconductor layer 22 and the conductive polymer layer 24 . In other words, the strength of the second adhesion is greater than the strength of the first adhesion. The weaker adhesion between the semiconductor layer 22 and the substrate 21 causes a weaker binding. Then, the substrate 21 is removed. Since the first adhesion is smaller than the second adhesion, therefore the semiconductor layer 22 will still be attached onto the conductive polymer layer 24 as shown in FIG. 2E to complete the transfer. In FIG. 2F , after the semiconductor layer 22 is transferred, a thermal evaporation method is used to evaporate a second electrode 25 onto the semiconductor layer 22 to complete manufacturing of the solar cell 2 . The second electrode 25 is a single-layer structure or a double-layer structure, and the single-layer structure is made of magnesium-gold alloy, and the double-layer structure is made of lithium/aluminum or calcium/aluminum. With reference to FIG. 3 for a graph of voltage versus current density of a solar cell manufacturing by a transfer method and a spin-coating method of the semiconductor layer containing PEG and a coating method of a semiconductor layer of a solar cell without containing any PEG at 100 mW/cm 2 and with a standard solar energy simulated light of AM 1.5 G, the characteristics of solar cells manufactured by using the transfer method and using the spin-coating method are similar, and it shows that the method of the present invention can be used for manufacturing the solar cells successfully by the transfer method. In addition, Table 1 shows the parameters of the solar cells manufactured by using a semiconductor layer containing PEG and a transfer method of (PEG600 (5%) (Transfer)), a spin-coating method of (PEG600 (5%) (Spin)), and using a semiconductor layer containing no PEG by a spin coating method of (P3HT and PCBM (Spin)). Parameters of each component of the solar cell are defined first. With infinite load resistance of the solar cell, the voltage is called open circuit voltage (VOC) when the external current is disconnected (or the current is equal to zero). When the voltage is zero, the current density is called short circuit current density (JSC). In the graph of the current density versus the voltage of the solar cell, the output power (P) at any working point is equal to the product (P=V×J) of the corresponding voltage (V) and current density (J) of the working point, wherein one of the working points (Vm, Jm) has the maximum output power (Pm, Pm=Vm×Jm). The ratio of the maximum output power and the product of the open circuit voltage and the short circuit current density is defined as a filling factor (FF) and FF=(Vm×Jm)/(VOC×J SC)). For solar cells with better component properties, the filling factor should be close to 1, in addition to the required high open circuit voltage and short circuit current density. The filling factor represents level of the maximum output power approaching the product of the open circuit voltage and close circuit current density. The power conversion efficiency (η=(V OC×J SC×FF)/P in) of the solar cell is defined as the ratio of the output power and the input light energy (P in), such that when the filling factor value is approaching to 1, the power conversion efficiency becomes increasingly higher. TABLE 1 Power Open circuit Short circuit conversion Filling voltage current density efficiency Factor VOC (V) Jsc (mA/cm 2 ) η(%) (FF) P3HT and PCBM 0.47 8.21 2.02 0.52 (SPIN) PEG600 0.51 9.47 2.25 0.47 (5%)(SPIN) PEG600 (5%) 0.53 7.86 2.16 0.52 (TRANSFER) From Table 1, the solar cell with the semiconductor layer containing no PEG has an open circuit voltage of 0.47V, a power conversion efficiency of 2.02%, and the solar cell with the semiconductor layer containing PEG and manufactured by the spin-coating method has an open circuit voltage increased to 0.51V, and a power conversion efficiency increased to 2.25%, and the solar cell with the semiconductor layer containing PEG and manufactured by the transfer method has an open-circuit voltage increased to 0.53V and a power conversion efficiency increased to 2.16%. Table 1 shows that the solar cell with the semiconductor layer containing PEG has a better function and effect than the solar cell with the semiconductor layer containing no PED, regardless of its manufacture by the spin-coating manufacturing process or the transfer manufacturing process. With reference to FIG. 4 for a schematic view of a roll-to-roll manufacturing process of a solar cell in accordance with the present invention, the roll-to-roll manufacturing process replaces the process of coating a solution onto the substrate as shown in FIG. 2A . In FIG. 4 , the roll-to-roll manufacturing process includes at least one roller 32 and a flexible substrate 31 , and further includes a solution 33 made by a p-type semiconductor material, an n-type semiconductor material and PEG. The surface of the roller 32 is made of a material similar to silicon dioxide, and with an appropriate pattern. When the surface of the roller 32 is rotating, the surface of the roller 32 is in contact with the solution 33 , such that the solution 33 is coated onto the flexible substrate 31 . The roll-to-roll manufacturing process makes use of the characteristic of the weaker contact force between the organic material and the surface of the roller, the solution can be coated quickly and easily onto the flexible substrate, so as to simplify the manufacturing process and reduce the manufacturing time for an easier entry of a mass production. The manufacturing method for an organic optoelectronic thin film in accordance with the present invention is not limited for the use of manufacturing solar cells only, but it can also be applied for manufacturing light emitting diodes, thin film transistors and flexible solar cells and modules. The manufacturing method for an organic optoelectronic thin film in accordance with the present invention can achieve the effects of simplifying the manufacturing process and saving the trouble of manufacturing the PDMS print mold to achieve the same transfer effect.

Disclosed is a manufacturing method for an organic optoelectronic thin film comprising the steps of providing a substrate and a first electrode; forming a semiconductor layer on the substrate, wherein the semiconductor layer includes polyethylene glycol (PEG); forming a conductive polymer layer on the first electrode; disposing the substrate and the semiconductor layer on the conductive polymer layer and adhering the semiconductor layer to the conductive polymer layer; and removing the substrate; and forming a second electrode on the semiconductor layer. A first adhesion between the semiconductor layer and the substrate is generated. A second adhesion between the semiconductor layer and the conductive polymer layer is generated. The second adhesion is greater than the first adhesion so that while the substrate is removed, the semiconductor layer and the conductive polymer layer are still adhered.

This is a continuation of application Ser. No. 484,360, filed Apr. 12, 1983, which was abandoned upon the filing hereof. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric fan device which is used with a cooling radiator for an automotive engine thereby to cool down the radiator. More specifically, the present invention relates to an electric fan device of the type, in which a cooling fan is attached to the output side of a flattened motor having a printed armature built therein. 2. Description of the Prior Art In an electric fan device for the radiator according to the prior art, a fan is fixed to the output shaft of an ordinary or flattened electric motor, and no special consideration is taken into the radiation of the heat which is generated in the armature of the electric motor. When the flattened electric motor is to be assembled and attached to the radiator, moreover, two divided motor housings are first assembled as the motor by means of rivets or screws and are then attached to the bracket or the like of the radiator. This requires both fixing means for fixing the motor to the bracket in addition to fastening means such as the screws for assembling the two divided housings and holes or the like which are formed in the housings for the fastening means and the fixing means. As a result, the electric fan device of the prior art has its assembly parts and steps increased to provide an expensive electric fan device. SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a radiator cooling electric fan device which makes use of a flattened electric motor so that it can efficiently radiate the heat to be generated in an armature whereby it can be prevented from having its output dropped. Another object of the present invention is to provide an electric fan device in which the assembly of the electric motor and the attachment to a radiator bracket are simplified so that the cost and the number of assembly steps can be reduced. According to a feature of the present invention, there is fixed to one of two divided housings a shaft, on which a metal rotor is rotatably supported, wherein a flattened armature plate is fixed to the metal rotor and a radiating member for radiating the heat generated in the armature plate to the outside is also fixed to the metal rotor. According to the construction thus made, the heat generated in the armature plate can be efficiently radiated to prevent the electric motor from having its output dropped. According to another feature of the present invention, at the joined portions of the two divided housings made of a ferromagnetic substance, one of the housings is formed with holes whereas the other is formed with annular projections to extend through those holes, and the two housings are joined to and held on each other by the magnetic force of the permanent magnet of the electric motor. At the stage of joining the two housings by the magnetic force of that permanent magnet, the assembly of the motor is completed. When the electric fan device is to be attached to the bracket of the radiator, the fastening means such as screws or rivets extend through the aforementioned annular projections to mount the motor on the bracket. As a result, simultaneously as the motor is mounted on the bracket, the two divided housings are fixedly joined at last. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially sectional view showing an electric fan device according to the present invention; FIG. 1A is a fragmentary sectional view showing on a larger scale a detail generally depicted at the upper left in FIG. 1; FIG. 2 is a side view showing the electric fan device; and FIG. 3 is an enlarged sectional view showing an essential portion of a modification in which terminals are connected with brush holders. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, an armature 1 will be described in the following. A center piece (or rotor) 2 made of die-cast or cold-forged aluminum is formed with steps 2a and 2b on its outer circumference. An armature plate 3 having a flattened shape is made to abut against the step of the center piece 2 such that it is electrically insulated by means of insulators 4 and 5 made of glass cloth. Then, a center ring 6 made of an aluminum or iron plate is made to abut against the lefthand side of the aforementioned insulator 4. Finally, the step 2b of the aforementioned center piece 2 is caulked to fix the aforementioned armature plate 3 to the center piece 2. In order to enhance the fixedness of the armature plate 3, incidentally, an adhesive may be applied to both the sides of the insulator 5. On the other hand, the cylindrical portion 7b of an oilless bearing 7 having a flange 7a is press-fitted in a step 2d, which is formed in the inner circumference of the center piece 2, such that the flange 7a abuts against the step 2d. On the other hand, a ball bearing 8 has its outer race 8a abutting against an opposite step 2e also formed in the inner circumference of the center piece 2. That outer race 8a in turn is press-fitted in the inner circumference 2f of the center piece 2 until it abuts against the step 2e. Moreover, the center piece 2 has its end face formed with a plurality of threaded portions 2g into which screws 10 for fixing a load (or fan) 9 are inserted. Next, one housing 11 will be described in the following. This housing 11 is formed by twice reducing a cold rolled steel plate with a bar ring 11b which is positioned at the center of a reduced portion 11a at the inner peripheral portion and which is directed inwardly. Moreover, the housing 11 is formed with one rectangular hole 11c into which a brush holder 12 can be inserted. Indicated at reference numeral 13 is a shaft which is formed with a flange 13a, a step 13b and a cylindrical portion 13c and which is fitted in the oilless bearing 7 and the ball bearing 8. The shaft 13 is made as a whole of carbon steel and is press-fitted in the inner wall of the aforementioned bar ring 11b. Moreover, the flange 13a of the shaft 13 is fixedly welded (as indicated at 13a1) in the form of a ring to the end face of the housing 11 so as to ensure water-tightness. On the other hand, the shaft 13 is formed at its portion opposite to the flange 13a with a groove 13d in which an E-ring 22 is fitted. The housing 11 is formed on its outer periphery with a reduced portion 11d which is directed inward likewise the bar ring 11b. Reference numeral 11e indicates an electric fan mounting hole. The brush holder 12 is molded of a phenol resin or the like and is formed with a rectangular hole 12a, in which a brush 14 and a brush holding spring 15 are inserted such that the brush 14 is urged to slide rightwardly of the drawing by the action of the spring 15. The brush 14 has its pigtail 14a welded and connected to the inner end of a terminal 16. The terminal 16 is formed with a pair of stopper pawls 16a and 16b and is inserted into a rectuangular slit 12b of the brush holder 12 so that it is prevented from coming out by the action of the pawls 16a and 16b. Moreover, the terminal 16 has its leading end portion formed with a hole 16c to which the core 19a of a lead wire 19 shown in FIG. 2 is connected after it has been inserted thereinto and welded thereto. As shown in FIG. 3, on the other hand, the rectangular slit 12b may have its inner periphery formed with projections 12c corresponding to the pawls 16a and 16b. In this modification, the terminal 16 can be fixed more fixedly to the brush holder 12. A ring-shaped magnet 20 is fixed by means of an adhesive to the flat portion 11f of the housing 11. This housing is formed at its outer periphery with the reduced portion 11d which is so axially bent as to cover the outer periphery of the other housing 17. A second housing 17 is made of a cold-rolled steel plate and is formed with a cylindrical portion 17a at its inner periphery. The cylindrical portion 17a has its inner circumference made larger than the external diameter of the step 2a of the center piece 2 of the aforementioned armature 1. Moreover, the cylindrical portion 17a has its leading end portion bent inward to repel water and dust. On the outer circumference of the cylindrical portion 17a, there is press-fitted a cylindrical portion 18a of a cap 18 which is made of a cold-rolled steel plate for water-tightness. The cap 18 is formed with a drain 18b which extends at a right angle (radially outwardly) with respect to the cylindrical portion 18a. Indicated at reference numeral 17b is the depth of reduction of the motor housing 17, which is selected to have such a size as to prevent the armature 3 from contacting with the housing 17. This housing 17 has its outer periphery formed with a flat portion 17c and made smaller than the outer periphery 11d of the housing 11. Moreover, the flat portion 17c is formed with a plurality of positioning and motor fixing bar rings 17d each of which is constituted by a respective annular projection which has its inner circumferential wall formed with internal threading 17e. Numeral 23a designates a radiating member made of a heat-conductive material such as aluminum, iron or the like and fixed to a radiator fan 23 made of a resin, for example. The radiating member 23a is then fixedly secured to the metal rotor 2 by means of the screws 10, so that heat generated at the armature 1 can be transmitted to the radiating member 23a through the rotor 2 and radiated into the air therefrom. Next, the order of the steps of assembling the embodiment thus constructed will be described in the following. First of all, the shaft 13 fixed to the housing 11 is inserted into the oilless bearing 7 and the ball bearing 8. Before this insertion, a clearance adjusting thrust washer 21 is sandwiched in position, if necessary, between the end face of the oilless bearing 7 and the step 13b of the shaft 13 so as to retain the clearance size between the surface of the armature plate 3 and the surface of the magnet 20. After this insertion, so as to retain the necessary thrusting allowance on the end face of the ball bearing 8, an adjusting thrust washer 21a is fitted, if necessary, and the E-ring 22 is press-fitted in the groove 13d of the shaft 13 so as to provide a stop for the thrusting motion. After the armature 1 has been assembled, a water-repelling sealing agent is applied to whole the periphery of the flat portion 17c of the housing 17, and the housings 11 and 17 are joined to each other. At this time, the housing 17 is fixed in position by the attracting force of the magnet 20 of the housing 11. Next, the method of assembling the fan 23 will be described in the following. The radiating member 23a of the fan 23 is applied to the end face of the armature center piece (rotor) 2 and fixedly fastened thereto by means of screws 10, and a sealing agent is applied to the head of the screws 10 so as to ensure the water-tightness. Next, the mounting structure of the electric fan device will be described in the following. The housing 11 is brought into abutment against the end face of a shroud 25 providing a mounting bracket, and a screw 26 is inserted into and fixedly fastened to the thread 17e of each bar ring 17d of the housing 17, each projection 17d having entered a respective hole 11e in the housing 11 in order to properly locate the housing 11 relative to the housing. Incidentally, although, in the foregoing embodiment, the male and female fitted portions of the locating means are formed of the holes 11e and the bar rings 17d, they may be formed of other portions to prevent the housings 11 and 17 from rotating relative to each other. Next, other embodiments of the present invention will be described in the following. The center piece 2 and the armature plate 3 may be integrally molded of a resin. In this case, the insulators 4 and 5 and the center ring 6 may be dispensed with. As the thrust stopping structure, on the other hand, in place of press-fitting the E-ring 22 into the groove 13d of the shaft 13, a toothed washer having a plurality of teeth on its inner wall may be axially press-fitted in accordance with the thrusting allowance required. In this case, a thrust washer may be inserted, if necessary. As the adjustment of the air gaps at both sides of the armature plate 3, on the other hand, the inner race of the ball bearing 8 and the cylindrical portion 13c of the shaft 13 are so sized that they can be fixedly press-fitted, in place of inserting the thrust washers 21 and 21a, and the bearing 8 is press-fitted on the shaft 13 so that the necessary air gaps may be retained at both the sides of the armature plate 3. With this construction, the thrust washers 21 and 21a can be dispensed with so that the assembly can be facilitated. As a counter-measure for preventing water from leaking around the screw 10 for mounting the fan 23, the sealing agent is applied to the head of the screw 10. According to another embodiment, however, a water preventing or repelling sealing agent may be applied to the righthand end face of the armature center piece 2. Moreover, the fan 23 may be assembled with the center piece 2 through a sealing gasket (or packing) or an O-ring. On the other hand, an insulating paint may be applied either by itself or together with a thin insulating seat to both the sides of the outer periphery of the armature plate 3, thereby to prevent the armature plate 3 from warping due to vibrations or the like and from contacting with the housing 17 and accordingly from being grounded. Incidentally, either the aforementioned insulating paint or thin insulating sheet may be applied to both the inner periphery of the housing 17 facing the armature plate 3 or the surface of the magnet 20. On the other hand, the armature center ring 6 for fixing the armature plate may be dispensed with by applying an adhesive to both the sides of the insulator 5 thereby to increase the fixedness. Although the cap 18 is press-fitted in the housing 17, the cap portion may be integrally molded by reducing the leading end portion 17a of the housing 17. In the above-described embodiment the fan 23 is attached by fixedly fastening the screw 10. However, the fan 23 may be fixed by forming a projection on the end face of the armature center piece 2, by inserting that projection into the hole of the member 23a of the fan 23 and by press-fitting a toothed washer having a plurality of teeth in the inner wall of the projection inserted. Incidentally, the housings 11 and 17 have to be made of a ferromagnetic substance such as steel if they are to be temporarily fixed by the magnetic force of the permanent magnet 20. The portions referred to as the bar rings 17d in the present invention are cylindrical projections which is cut out of a metal plate by the pressing operation. Moreover, the fixture 25 may be rivet or a bolt in addition to the screw. On the other hand, the bracket 25 may be an arm-shaped bracket or the like in addition to the shroud. In the embodiments of the present invention thus far described, by the force acting in the axial direction of the permanent magnet 20 and as a result that each bar ring 17d, for example, providing the male fitted portion is fitted in a respective hole 11e, for example, providing the female fitted portion, there can be attained effects that the housings 11 and 17 can be temporarily fixed to a sufficient extent without coming out in the axial directions and rotating relative to each other, that the housings 11 and 17 can be firmly fixed to each other simultaneously as the flattened electric motor is to be attached to the bracket 25, that the mounting fixture 26 can be commonly used, and that the number of the assembling steps can be reduced. In the foregoing embodiment of the present invention, moreover, the brush holder acts partly to hold the brush and partly to function as a grommet for extending therethrough the lead wire for leading the electric power into the housings of the electric motor. As a result, there can be attained an effect that the special grommet can be dispensed with so that the number of parts can be reduced together with the production cost.

As a drive source of a blowing fan for a vehicular radiator, there is used a flattened electric motor, wherein there is fixed to one of two divided housings a shaft, on which there is rotatably supported a rotor to which a flattened armature coil is joined and to which the blowing fan is fixed through a radiating member. Thus, the heat, which is generated in the armature coil, is transferred through the rotor and/or the shaft to the radiating member, by which it is efficiently radiated into the air.

CROSS REFERENCES TO RELATED APPLICATIONS This application is a continuation of U.S. application Ser. No. 10/089,427, filed on Jun. 26, 2002 now U.S. Pat. No. 6,698,342, which was a U.S. national stage application of International Application No. PCT/FI00/00821, filed Sep. 26, 2000, and claims priority on Finnish Application No 19992086 filed Sep. 29, 1999. STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT Not applicable. BACKGROUND OF THE INVENTION The present invention relates to the calendering of a fibrous web. Calendering is a method by means of which the properties, in particular the thickness profile, smoothness, gloss, surface porosity and translucence of a web-like material, such as a paper web, are sought to be generally improved. In calendering the paper web is passed into a nip which is formed between rolls pressed against each other and in which the paper web is deformed by the action of temperature, moisture and nip pressure, in which connection the physical properties of the paper web can be affected by controlling the above-mentioned parameters and the time of action. The good physical properties attained by calendering lead to better print quality, thereby bringing a competitive advantage to the manufacturer of paper. The so-called shoe rolls known in prior art are usually hydraulically deflection-compensated, zone-controlled rolls in which the shell is supported from a non-rotating central shaft of the roll by means of hydrostatic loading arrangements, such as rows of loading shoes, which transfer the nip force acting on the shell rotating around the central shaft so as to be carried by the central shaft. The loading element is generally also divided into zones, in which connection the loading pressure can be regulated as required by profiling. The zoning in this kind of zone-controlled shoe roll may comprise individual elements in the loading arrangement, in which connection the number of zones in the roll and in the loading arrangement may exceed 60—as examples may be mentioned the shoe rolls marketed by Metso Paper, Inc. under the trademarks SymCD™ and SymCDS™, or the zoning may comprise a group of elements in the loading arrangement, in which connection the roll and the loading arrangement normally comprise eight zones—as examples may be mentioned the shoe rolls marketed by Metso Paper, Inc. under the trademarks SymZ™, SymZS™, SymZL™, and SymZLC™. Extended-nip calendering accomplished by means of a shoe roll has generally been found to be good for producing low-gloss paper grades, i.e. grades having a Hunter gloss % below 40. When higher gloss is required, the nip pressure of extended-nip calendering is, however, not any more sufficient to provide gloss. In the papermaking art, grades of ever higher quality are required today. As the running speeds required of paper machines are continuously increasing, the direction in calendering technology is more and more towards on-line solutions. When the aim is to make higher quality printing paper grades, such as, for example, SC-A and LWC-roto grades and glossy coated paper grades, a substantial problem is that this kind of grades can be produced in practice only by using, after drying a fibrous web, intermediate winding and off-line supercalenders, several of said supercalenders, usually two or three, being used side by side to meet production capacity. Supercalendering is calendering in a calender unit in which nips are formed between a smooth-surface press roll, such as a metal roll, and a roll covered with a resilient coating, such as a paper or polymer roll. The resilient-surface roll adapts itself to the contours of the surface of paper and presses the opposite side of paper evenly against the smooth-surface press roll. Today, the supercalender typically comprises 10-12 nips and for the purpose of treating the sides of the web, the supercalender comprises a so-called reversing nip in which there are two resilient-surface rolls against each other. Linear load increases in the supercalender from the top nip to the bottom nip because of the force of gravity. This increase in load can be compensated for by using the relieving of the rolls. Supercalendering is an off- and on-line calendering method, and at the moment it provides the best paper qualities, such as, for example, WFC, LWC-roto and SC-A. Soft calendering is calendering in a calender unit in which nips are formed between a smooth-surface press roll, such as a metal roll, and a roll covered with a resilient coating, such as a paper or polymer roll. In a soft calender, the nips are formed between separate roll pairs. In order to treat both sides of the web in the soft calender, the order of the roll pairs forming the successive nips is inverted with respect to the web so that the resilient-surface roll may be caused to work on both surfaces of the web. Soft calendering is an on- or off-line calendering method, and grades, such as, for example, MFC and film coated LWC as well as SC-C can be produced by means of it. Multi-roll on-line, off-line calendering is calendering in a calender unit in which the number of rolls is higher than in soft calenders, most commonly 6-16. Multi-roll calenders are soft-nip calenders. The resilient-surface roll conforms to the contours of the surface of paper and presses the opposite side of paper evenly against the smooth-surface press roll. Linear load increases in the multi-roll calender from the top nip to the bottom nip because of the force of gravity. By using the relieving of rolls, this increase in load can be compensated for. This kind of relieving of the rolls is provided in Metso Paper, Inc.'s OptiLoad™ calender. Multi-roll on-line, off-line calendering is a calendering method, allowing grades from WFS up to uncoated fine paper to be produced. SUMMARY OF THE INVENTION The primary object of the present invention is to improve calendering of a fibrous web in connection with a papermaking process, to improve control of the moisture gradient of a fibrous web, such as a paper or board web, to diminish the process problems now associated with the manufacture of high quality paper grades, such as WFC, LWC-roto and SC-A, and to enable the manufacture of high quality paper grades, such as WFC, LWC-roto and SC-A by on- or off-line calendering. Thus, the invention is based on the new and inventive idea that an on- or off-line multi-roll calender comprising separate sets of rolls is used for calendering, and that the fibrous web is subjected to intermediate moistening between the sets of rolls. In accordance with an advantageous embodiment of the invention, the multi-roll calender comprises two sets of rolls, in which connection the moisture content of the fibrous web coming from the drying process is raised to a level of 3-10% by means of pre-moistening preceding the first set of rolls, the fibrous web is dried to a level of 1-6% in the first set of rolls, the moisture content of the fibrous web is raised to a level of 6-14% by means of intermediate moistening after the first set of rolls, and the fibrous web is dried in the second set of rolls to a desired final moisture level, which is advantageously in a range of 4.5-7.5%. With respect to the benefits of the invention, it may be mentioned that by means of the multi-stage moistening and gradient calendering according to the invention it is possible to better and more accurately affect only the surface layers of the fibrous web and to leave the inner layers of the fibrous web substantially untouched, which allows higher quality paper grades to be produced by on- or off-line calendering. BRIEF DESCRIPTION OF THE DRAWINGS In the following, the invention will be described in more detail by means of one of its embodiments considered advantageous with reference to the accompanying patent drawing whose figure FIG. 1 schematically shows a multi-roll calender according to an embodiment of the invention regarded as advantageous. DESCRIPTION OF THE PREFERRED EMBODIMENTS The calender in the embodiment shown in FIG. 1 is a multi-roll calender comprising two sets of rolls A and B in accordance with the invention. Both sets of rolls A and B of the multi-roll calender are formed of smooth-surface press rolls 3 , such as metal rolls, rolls 4 covered with a resilient coating, such as paper or polymer rolls, and reversing or guide members 5 guiding the run of a web W to be calendered, placed alternately one after the other in the machine direction. The successive nips N of the multi-roll calender are thus always formed between a roll 3 having a rigid shell and a roll 4 having a resilient shell. Since the multi-roll calender is an on- or off-line calender, the fibrous web W which is calendered is passed from a drying process D without any intermediate winding directly to the calendering process. In the calendering process accomplished by means of the multi-roll calender with two sets of rolls in accordance with the invention, the run of the fibrous web W to be calendered is as follows. The fibrous web W is passed by means of a guide roll 1 through pre-moistening into the topmost nip N of the first set of rolls A in the multi-roll calender, from which nip the fibrous web W is passed around a reversing member 5 , for example a reversing roll, into the next lower nip. After that, the fibrous web W meanders around a reversing member 5 and runs through the nips situated one underneath the other until the fibrous web W has been passed through the bottom nip in the first set of rolls A. After that, the fibrous web W is passed into the topmost nip N of the second set of rolls B, from which the fibrous web W is passed again around a reversing member 5 into the following lower nip. The fibrous web W meanders again around a reversing member 5 and runs through the nips N situated one underneath the other until the fibrous web W has been passed through the bottom nip N in the second set of rolls B. After the bottom nip of the second set of rolls B, the fibrous web W is passed to a process stage after calendering, which is, for example, reeling R. In accordance with the invention, this run of the fibrous web is affected such that the fibrous web to be calendered is dried in the drying process D so that it is overdried, i.e. to a moisture content that is lower than the equilibrium moisture content dependent on the ambient operating conditions, and the moisture content of the fibrous web W passed from the drying process D to the calendering is raised by means of a pre-moistening unit 2 preceding the first set of rolls A, the fibrous web W is dried in the first set of rolls A, the moisture content of the fibrous web W is raised after the first set of rolls A by means of an intermediate moistening unit 7 , and the fibrous web W is dried to a desired final moisture level in the second set of rolls B. In that connection, in accordance with the invention it is advantageous that the first drying with the pre-drying unit 2 raises the moisture content of the fibrous web W, which is advantageously overdried according to the invention, to a level of 3-10%, in which connection the first set of rolls A can dry the fibrous web W to a level of 1-6%, and that the second moistening with the intermediate moistening unit 7 raises the moisture content of the fibrous web W to a level of 6-14%, in which connection the second set of rolls B can dry the fibrous web W to a desired final moisture level, which is advantageously in a range of 4.5-7.5%. This kind of multi-stage moistening allows the moistening to be applied substantially only to the surface layers of the fibrous web and enables the moisture gradient of the fibrous web to be controlled with fewer problems and more quickly than before, thereby allowing provision of higher quality paper grades, such as, for example, WFC, LWC-roto and SC-A. To control the amount of the intermediate moistening of the fibrous web W and/or the penetration of moisture into the fibrous web and to thereby control the moisture gradient, the intermediate moistening unit 7 , which is either a water moistener or an electricity-aided moistener, can be arranged optionally either to moisten the fibrous web W on one side or to moisten the fibrous web on both sides. In order to minimize the formation of drop marks, the surface energy of the fibrous web W is lowered prior to the intermediate moistening unit 7 by manipulating the surface energy of the fibrous web, whereby the spreading of water on the surface of the fibrous web is accelerated because of the reduced surface energy of the fibrous web. In one embodiment of the invention regarded as advantageous, a unit 6 for reduction and/or manipulation of the surface energy of the fibrous web W comprises a unit for corona treatment of the fibrous web, which unit is linked with the intermediate moistening unit 7 composed of a water moistener. Above, the invention has been described only by way of example by means of one of its embodiments regarded as advantageous. This is naturally not intended to limit the invention and, as is clear to a person skilled in the art, a variety of alternative arrangements and modifications are feasible within the inventive idea and within the scope of protection thereof defined in the accompanying claims.

A multi-roll calender for controlling the moisture gradient of a fibrous web and for enabling the manufacture of high quality paper grades, such as WFC, LWC-roto and SC-A by on- and off-line calendering. An on- or off-line multi-roll calender formed of separate sets of rolls is used for calendering, and the fibrous web (W) is subjected to intermediate moistening between the sets of rolls (A, B).

This is a Continuation-In-Part of International Patent Application No. PCT/IL2005/000087, filed Jan. 25, 2005, and published as WO 2005/070583, which in turn takes priority from Provisional Patent Application No. 60/538,500 filed Jan. 26, 2004. FIELD AND BACKGROUND OF THE INVENTION The invention relates to an apparatus and method for forming of a vehicle's driveshaft having an elongated shaft and two coupling end parts. This is achieved, in accordance with the invention, by a pulsed magnetic force (PMF) process. A vehicle's driveshaft, having the general structure as outlined above, is commonly manufactured by welding ends of a cylindrical shaft to coupling end parts. Conventional welding is a time consuming and relatively expensive process. Furthermore, the workpieces are typically heated in this process and therefore at times cooling installations need to be included. A known way of rapid “cold” joining or welding of workpieces to one another is by the use of a PMF process. By this technology, a very short and intense electric pulse is discharged through a coil and this discharge induces eddy currents in a workpiece which yield magnetic repulsion between the electric coil and the workpiece. This repulsion then deforms the workpiece proximal to the forming coil causing its surface to rapidly move and impinge on another workpiece whereby it either pressure joins, and with higher energy surface welds to the other workpiece. A particular application of this process is in joining or surface welding of a tubular workpiece onto a cylindrical one contained therein by inducing inward radial deformation of the tubular workpiece. PMF processes and some specific applications thereof are disclosed in the following U.S. Pat. No.: 3,654,787 (Brower), U.S. Pat. No. 3,961,639 (Leftheris), U.S. Pat. No. 4,170,887 (Baranov), U.S. Pat. No. 4,531,393 (Weir), U.S. Pat. No. 4,807,351 (Berg et al.), U.S. Pat. No. 5,353,617 (Cherian et al.), U.S. Pat. No. 5,442,846 (Snaper) and U.S. Pat. No. 5,824,998 (Livshitz et al.). A specific application of the PMF process for the purpose of joining components for a vehicle's driveshaft is described in U.S. Pat. No. 5,981,921. There are some specific problems in the realization of the PMF process for forming a driveshaft in that the end pieces radially protrude beyond the circumference of the shaft. In order to utilize the PMF process, the forming coil should be brought into close proximity to the deformed workpiece and in this case this means that the forming coil needs to be closely fitted around the shaft. After joining or surface welding of the shaft and the coupling end part, it is not possible, with the prior art methods, to release the coil turnover and the driveshaft. This is the reason, that the PMF process has not yet found a true application in practice in the field of forming of driveshafts. SUMMARY OF THE INVENTION In accordance with the invention an apparatus and method for forming a driveshaft is provided. In accordance with the invention, the above noted problems are overcome by providing an apparatus and utilizing a method in which the forming coil is assembled around the shaft from two or more coil sections which are firmly attached to one another. This forming coil is associated with a current generating unit such that through current discharge from said unit a PMF is produced to cause pressure joining or surface welding of the two driveshaft components. In the following, the term “joining” will be used to jointly denote both joining of two workpieces, which means bringing their juxtaposed surfaces into very close proximity in a manner so that they pressure impact with one another, as well as surface welding which means in effect a molecular interaction between their juxtaposed surfaces of the two workpieces. In fact, whether joining or welding is achieved in the PMF process depends, to a large extent, on the amount of PMF energy and of the exact working parameters. The artisan will be able to define whether joining or surface welding is required and also to define the exact parameters needed to achieve either joining or welding. For parameters to achieve welding, reference is made to U.S. Pat. No. 5,824,998, which is incorporated herein by reference. As stated, the term “joining” should be construed as referring to either or both of joining and welding. In accordance with the invention there is provided a novel apparatus and method for forming a driveshaft of the kind having a shaft and two coupling end parts of radial dimensions larger than those of the shaft. The apparatus comprises one or two forming assemblies for forming one end or two ends of a driveshaft, respectively; the one or two forming assembles comprising each a holder and a forming unit. The holder is a adapted to receive and hold a driveshaft end part pre-assembly which after joining will form the end part of the driveshaft. The pre-assembly consists of two components, of which one is an end section of an elongated shaft that defines an axis, and the other is a coupling end part member, either the shaft end section or a portion of the end part member having a generally cylindrical shape with an axial cylindrical cavity that accommodates an axial cylindrical portion of the other snugly fitted therewith, the end section and said portion defining together a cylindrical joining section of the two components. The forming unit comprises a forming coil device that defines a forming space which can accommodate said joining section and comprises a current generating unit that is associated with the forming coil device, for generating a current pulse within the forming coil unit thereby to yield a PMF sufficiently strong to yield joining the two parts of the joining section. The forming coil device is assembled from two or more coiled sections which are firmly attached to one another at attachment faces thereof, which can be disassembled to permit release of the so formed driveshaft end part. The method for forming a driveshaft in accordance with the invention comprises: (a) providing a shaft, the shaft defining an axis, and a coupling end part member; either the shaft end section or a portion of the end part member having a generally cylindrical shape with an axial cylindrical cavity and the other having an axial cylindrical portion that can fit within said cavity, and fitting said cylindrical portion into said cavity to define together a joining section with an external cylindrical shape cavity can accommodate of the other snuggly fitted therewithin and defining together a cylindrical joining section of the two components; (b) fitting a forming coil device around said joining section, the forming coil device being assembled from two or more coil sections firmly attached to one another at attachment faces thereof and being associated with a current generating unit; (c) generating an intense current pulse through said forming coil device to generate a pulsed magnetic force (PMF) sufficient for joining the two parts of the joining section; and (d) disassembling the forming coil device to free the so formed end section of the driveshaft. Steps (a) and (d) may either be performed simultaneously for the two ends of the shaft to simultaneously join two coupling end part members one to each end of the shaft Alternatively, these steps may be performed in sequence by first carrying out steps (a) to (d) for joining one coupling end part member to one end of the shaft and then repeating these steps for joining another coupling end part member to the other end of the shaft. An apparatus for simultaneous forming of the two end parts of a driveshaft will comprise two forming assemblies. Where the apparatus comprises a single forming assembly, first one end will be formed, the shaft will then be reversed and the other end will then be formed. In accordance with one embodiment of the invention, the forming coil is connected directly to a current discharge circuitry. In accordance with this embodiment, the coil device is comprised of two or more, typically three or more coil sections of which two are end section connected each to one pole of the current discharge circuitry. In the case of three coil sections, for example, two are such end sections and one is an interconnecting section. In accordance with one embodiment, a coil of this kind is formed from a dielectric, non-electrically conducting material with an inner layer made of an electrical material. The dielectric material there serves as a structured element. An example of such a material is epoxy glass. The conducting layer may be made of copper as well as any other suitable method substance. Typically, the conducting layer extends also to the attachment faces and serves as the electrical link between the different sections. The different sections may be held together by a reinforcing structure, may be connected to one another by the use of screws and bolts and in general by any other suitable means. In accordance with another embodiment, the forming coil device is an independent coil device being an inductive association with a primary coil which is in turn connected to a current discharge circuitry, whereby a current pulse discharged through the primary coil induces the generation of a forming current pulse within the forming coil. In accordance with the one preferred embodiment, a forming unit comprises a primary coil connected to a current discharge circuitry for generating an intense current pulse, and two or more inserts, each of which constitutes a section of a forming coil device accommodated within an opening defined by the primary coil, the opening being of a diameter sufficient to permit the coupling end part to pass therethrough, and defining in turn a forming space to accommodate said joining section; the inserts being made of or having at least outer, inner and radial faces being made of an electrically conducting layer and being attached to one another at attachment faces with an electrically insulating layer between them. The inserts, in accordance with this embodiment, are typically a trapezoidal cross-section with the broad base facing outwards and the narrow base facing inwards juxtaposing the joining section. The method in accordance with the above preferred embodiment, comprises: fitting a forming coil device adjacent said joining section, the forming coil device comprises a primary coil connected to a current discharge circuitry for generating an intense current pulse, and two or more inserts, each of which constitutes a section of a forming coil device accommodated within an opening defined by the primary coil, the opening being of a diameter sufficient to permit the coupling end part to pass therethrough, and defining in turn a forming space to accommodate said joining section; the inserts being made of or having their external layer made of an electrically conducting layer and being attached to one another at attachment faces with an electrically insulating layer between them; generating an intense current pulse through said primary coil to induce a forming current in the inner face of the forming coil device to generate a pulsed magnetic force (PMF) sufficient for joining the two parts of the joining section; and disassembling said inserts and removing the primary coil by axially moving either the primary coil or the formed driveshaft end. In accordance with one preferred embodiment, it was found that superior joining is achieved by the use of an auxiliary device which is temporarily fitted together with the end part member to yield together a body having axial symmetry. After formation of the joins between the shaft and the end part member, the auxiliary device is removed. BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the invention and to see how it may be carried out in practice, a preferred embodiment will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: FIG. 1A is a schematic longitudinal section through a prior art vehicle driveshaft. FIG. 1B is a longitudinal section of the vehicle driveshaft of the invention. FIG. 1C shows the end section of the shaft overlapping the end recess of the end part prior to constriction to form the driveshaft of FIG. 1B . FIG. 2A is a partial longitudinal cross-section of an apparatus of the invention with a driveshaft to be formed therewith. FIG. 2B is a view from the direction of arrow II in FIG. 2A . FIG. 3A is a schematic longitudinal cross-section of an apparatus in accordance with another embodiment of the invention with the driveshaft to be formed therewith. FIG. 3B is a cross-section through lines III-III in FIG. 3A . FIG. 4 shows a typical fork-shaped driveshaft end piece. FIG. 5 is a partial view of an apparatus of the invention adapted for joining an end piece of FIG. 4 . FIG. 6 shows a coil device structure in accordance with another embodiment of the invention. FIG. 7 is a view similar to FIG. 1C illustrating use of an intermediate driver element according to a further feature of the present invention. FIG. 8 is a view similar to FIG. 3A illustrating use of an intermediate driver element according to a further feature of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference is first being made to FIG. 1A , which shows a prior art driveshaft. The driveshaft 1 consists of a tubular shaft 2 and two coupling end parts 3 and 4 , one at each end of shaft 2 . The two ends 2 A and 2 B of shaft 2 are sealed each in a respective recess 3 A and 3 B of end parts 3 and 4 , respectively, and welded to it by conventional welds 3 B and 4 B, respectively. In distinction from prior art driveshafts, driveshaft 6 made in accordance with the invention, shown in FIG. 1B (where like elements were given the same reference numeral with a prime indication), is formed by welding the shaft 2 ′ to the coupling end parts 3 ′ and 4 ′ by the use of a PMF process. The ends 2 A′ and 2 B′ are constricted and sealed in recesses 3 A′ and 4 A′, the constriction being achieved through a PMF process such as that will be described below. Through the PMF process ends 2 A′ and 2 B′ also become welded to respective recesses 3 A′ and 4 A′. As will also be appreciated, while the shaft shown herein is a tube, in other embodiments of the invention it may be a solid, elongate cylindrical mass. FIG. 1C shows the end 2 A′ of shaft 2 ′ overlapping the recess 3 A′ of end part 3 ′ prior to PMF application. There is a gap between these two workpieces such that ratio of h as the length l of the overlapping portion typically meet the formula h/l=0.1−0.5. FIGS. 2A and 2B show a forming coil device generally designated 8 accommodating a driveshaft pre-assembly consisting of an end part member 10 having flange portion 12 and an end section 11 of tubular shaft. The coil device 8 is a single wind coil formed by three coil sections 14 A, 14 B and 14 C each of which is constituted from respective dielectric body 15 A, 15 B and 15 C and with respective conducting layers 16 A, 16 B and 16 C. Layers 16 A, 16 B and 16 C may typically be made of copper or any other high conductive material. The dielectric body 15 A, 15 B and 15 C may, for example, be made of epoxy glass or any other suitable dielectric material which has the property of being able to resist strong and abrupt forces (the PMF process causes very strong radial forces on the forming coil). Each of the layers 16 A, 16 B and 16 C extend over attachment faces 17 by which the different coil sections are attached to one another. This ensures electrical contact between the conducting layers in the different coil sections whereby all conducting layers constitute together a single wind coil. At their other end conducting layers 16 A, 16 B terminate in two respective protruding conductor sections 18 A and 18 B linked to a discharge circuit 19 consisting of a capacitor battery 20 and a switch 21 . Bodies 15 A, 15 B and 15 C may comprise respective cooling channels 21 A, 21 B and 21 C having inlets and outlets, that is inlet 22 and outlet 23 , respectively, and transfer of a cooling fluid (a gas or liquid) therethrough. The different coil sections may be held together by a variety of means such as for example an external holding structure or any other suitable fixing arrangement as may be known per se. As can be readily appreciated, after joining of a tubular section 10 to the end section 11 of the shaft, the coil device is disassembled to free the formed driveshaft end section. Reference is now being made to FIGS. 3A and 3B showing an apparatus, generally designated 30 , with a driveshaft pre-assembly 31 consisting of a shaft 32 and two end part members 33 , one at each end of shaft 32 . In the apparatus of this embodiment, the two end parts of the driveshaft are formed simultaneously. Pre-assembly 31 is mounted between two holders 35 having a stepped protrusion 36 with an inner section 37 fitted within the lumen of shaft 32 , an intermediate section 38 and an outer flange 39 . In this way, the pre-assembly is firmly held in a firm pre-assembly arrangement. The apparatus comprises two forming assemblies 40 and 41 each including a multi-wind primary coil 44 and 45 , respectively, which are interconnected by a lead 46 and linked at their respective ends 47 to a current discharge circuitry 48 including a capacitor battery 49 and a switch 50 . The primary coils 44 and 45 are coaxial with shaft 32 . Two crescent shaped field shapers 42 and 43 are fitted within the space defined by the primary coils 44 , 45 and constitute together a forming coil device 51 also coaxially with the shaft 32 . The two field shapers 42 and 43 define together a forming space 52 fitted around the portions of the pre-assembly which are to be joined to one another. Holes 55 may be formed in the field shaper sections 42 , 43 for both cooling and current concentration. The ends 56 and 57 are insulated to avoid electric contact between the two inserts. In operation, a very short and intense electric pulse is actuated by the discharge circuitry 48 which then passes through primary coils 44 , 45 inducing an oppositely directed current in field shapers 42 and 43 and this current circulating in each of the field shapers causes a magnetic repulsion between the field shapers and the pre-assembly portions contained within the forming space thereby causing the two to pressure join, and with higher energies to surface weld, to one another. In this embodiment, both joins are formed simultaneously. It is appreciated that it is possible, in accordance with other embodiments, to separate the primary coils 44 and 45 and provide each with an independent current discharge circuitry having each an independent ignition arrangement. Alternatively, coils 44 and 45 may also be in a parallel electrical conductor (i.e. both to the same discharge circuitry). In the specific embodiments of the apparatus shown in FIGS. 3A and 3B , field shapers 43 are fixed onto a pole 60 while field shapers 42 are linked to an opening mechanism 61 . At the end of the operation, primary coils 44 and 45 can be moved axially to permit removal of field shapers 42 . After such removal, the so formed driveshaft may be removed. When the coupling end part member has a significant axial asymmetry close to the portion which is to be joined or welded, for example, a fork-shaped end part as is typically the case with driveshafts end parts, the electromagnetic field generated by the PMF process, may become irregular near the asymmetrical end piece portion, which may cause non-uniformity of the joins. In order to overcome this problem, an auxiliary device may be used, aimed at temporal restoring the axial symmetry of the coupling end part member. The insert is preferably produced from a material similar in electromagnetic properties to the coupling end part member. FIG. 4 shows a typical driveshaft coupling end part member which consists of a cylindrical joining portion 71 and a fork connector portion 72 . In FIG. 5 the axial asymmetry of fork 70 is compensated for by the use of an auxiliary device 75 , which in this case constitutes an integral part of the holder 31 . When the pre-assembly is fixed on holder 31 , the fork 72 combines with the auxiliary device 75 to induce a combined body with an axial symmetry. When the driveshaft is unloaded from the apparatus, the auxiliary device stays connected to a holder 31 . A coil assembly useful in an apparatus in accordance with another embodiment of the invention is shown in FIG. 6 . Two forming coil members 81 and 82 , form part of structures 83 and 84 , respectively, shown herein in an exploded view but which in use are placed proximal to one another with a distance between them of about 2 mm or less. Structure 83 is a closed loop conductor constituted by a planar conductive strip, but for coil member portion 81 . Structure 84 is constituted from a similar planar conductive strip, ending, however, at open ends 85 and 86 connected to a discharge circuitry (not shown). In use, when current is discharged through conductor structure 84 , current progresses along arrows 90 and this causes a counter current in the direction of arrows 91 in conductor structure 83 . This yields an overall circular current around forming space 95 defined by two coiled sections 81 and 82 . Placed in this forming space 95 , is the portion to be joined of the driveshaft pre-assembly with the coupling end part facing towards the interior of conductor structures 83 and 84 . Turning finally to FIGS. 7 and 8 , since the technique of PMF forming is based upon induced electric eddy currents within the workpiece, the energy efficiency of the technique is much lower for metals having relatively poor electrical conductivity (such as Steel, Titanium and Nickel alloys) than for those with high conductivity. In order to improve the efficiency of the technique, certain implementations of the present invention employ a driver element, formed from metal with a higher electrical conductivity than the workpieces, deployed around at least part of the joining region. The presence of this driver element reduces the energy required for a given welding effect. This feature will now be illustrated with reference to FIGS. 7 and 8 . FIGS. 7 and 8 are generally similar to FIGS. 1C and 3A , respectively, and employ the same reference numerals for equivalent elements. As seen in FIG. 7 , the workpiece is here modified by addition of a driver element 99 deployed in close overlapping relation with at least part of the region of overlap of end 2 A′ and recess 3 A′. Driver element 99 is formed from a metallic material with electrical conductivity higher than that of the recessed element, and most preferably, from a high-conductivity metallic alloy such as an Aluminum or Copper alloy. Driver element 99 preferably extends around the entire circumference of the cylindrical joining region, and most preferably also overlaps substantially the entire length l of the joining region. The element may be implemented as a solid metal collar, or may be flexible foil wrapped around the joining region. The total thickness of driver element 99 is preferably in the range from 0.3 mm to 2 mm, and its width (i.e., the dimension parallel to the axis of the shaft) is preferably in the range from 1 mm to 30 mm. After welding, driver element 99 may remain as part of the joined structure, or may be removed (e.g., peeled off) by any suitable mechanical or other technique. FIG. 8 shows a forming device similar to that of FIG. 3A , with equivalent elements labeled similarly. In this case, field shapers 42 and 43 have been modified to allow space of driver element 99 . In all other respects, the structure and operation of the device of FIG. 8 is essentially the same as that of FIG. 3A described above. It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims.

An apparatus ( 30 ) and method for forming of a vehicle's driveshaft ( 32 ) is provided which makes use of a PMF process. The coil device used in the PMF apparatus is assembled around the shaft from two or more coil sections ( 40, 41, 43; 42, 44, 45 ) firmly attached to one another, and which may be disassembled from one another to allow to remove the formed driveshaft ( 32 ).

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an element wire assembly that is applicable to, for example, motor coils as windings in which a plurality of element wires are bunched up into one unit and a method for manufacturing the element wire assembly. [0003] 2. Description of Related Art [0004] Technological development is conducted on a daily basis for attaining a downsizing and high output of a number of in-vehicle motors including a motor for driving a hybrid vehicle or an electric vehicle. One way to attain both objectives includes enhancing the space factor of a coil in a slot of a stator core. In addition, one way to enhance the space factor of the coil includes applying a rectangular cross-section wire to an element wire for the coil in place of a circular cross-section element wire (round wire) that has been commonly used so far. [0005] The rectangular wire that is conventionally used in general includes the element wire in which an insulating film made of thermoplastic resin such as polyamide (PA) or polyphenylene sulfide (PPS) or thermosetting resin such as enamel resin is formed on the periphery of a rectangular copper conducting wire and the cross section is shaped into a rectangle. [0006] Although the space factor of the coil can be enhanced by using the rectangular copper wire as the element wire as described above, the increase in the cross-sectional area of the copper element wire causes a problem of the increase in eddy current loss. [0007] One way to reduce such eddy current loss includes using an element wire assembly (also referred to as assembled copper wires) in which fine wires having small cross sections are bunched up. However, when the element wire assembly is formed by bunching up the element wires provided with an enamel coat or the like on the periphery of the copper conducting wire and then the coil is formed by winding the element wire assembly, clearance is easily created between the adjacent element wires. Thus, this may cause a problem of decrease in the space factor of the coil by contraries. [0008] Meanwhile, there is a way to prevent the decrease in the space factor described above by bunching up the element wires of different shapes to form the element wire assembly; however, such an element wire assembly requires the preparation of the element wires of different shapes, and this may need a manufacturing time and cause the increase in manufacturing cost. [0009] Japanese Patent Application Publication No. 2000-090747 (JP 2000-090747 A) discloses a rectangular Litz wire. The rectangular Litz wire is formed in a rectangle in cross section by rolling a round Litz wire that is circular in cross section and in which a plurality of enameled element wires are twisted together. Adhesive tape on which an adhesive material or a thermoplastic material is applied is longitudinally applied to the outer periphery of the rectangular Litz wire. [0010] Japanese Patent Application Publication No. 2009-199749 (JP 2009-199749 A) discloses a method for manufacturing a conducting wire including twisting a plurality of element wires coated with an insulating layer to constitute a stranded wire, compression-molding the stranded wire with a shaping die in this state to shape the cross section of the stranded wire into a specified shape, and then coating the surface of the stranded wire with the insulating layer that is thicker than the thickness of the insulating layer constituting the surface of the element wire. [0011] Furthermore, Japanese Patent Application Publication No. 2006-100077 (JP 2006-100077 A) discloses a wire rod for a winding that has a conductor insulating film on the outside of a conductor. One conductor of a specific cross section is formed by assembling a plurality of split element wires, and each of the split element wires is constituted by a conductor core wire and a core wire insulating film that covers the conductor core wire. The method for manufacturing a wire rod for a winding disclosed in JP 2006-100077 A includes a step of preparing a plurality of conductor core wires, a step of forming the split element wires by forming the core wire insulating film on each of the conductor core wires, a step of forming the conductor with a specified cross-sectional shape by assembling the plurality of split element wires, and a step of forming the conductor insulating film on the outside of the conductor. [0012] As described above, JP 2000-090747 A, JP 2009-199749 A, and JP 2006-100077 A disclose the element wire assembly and the method for manufacturing the same; however, each disclosure has been based on the manufacturing method in which the element wires having the insulating film are bunched up and formed in one unit by rolling and other processes. Thus, those disclosures do not solve the aforementioned problem, that is, the problem in which a clearance is easily created between adjacent element wires and the space factor of the coil decreases when the coil is formed by using the element wires. SUMMARY OF THE INVENTION [0013] The present invention relates to an element wire assembly in which a plurality of element wires are bunched up into one unit and a method for manufacturing the element wire assembly, and also the present invention provides the method for manufacturing the element wire assembly in which a coil with a high space factor and a superior eddy current loss reduction performance can be fabricated and the element wire assembly that is fabricated by the method for manufacturing the same. [0014] A first aspect of the present invention relates to a method for manufacturing an element wire assembly including: a first step of bunching up and rolling or drawing a plurality of circular cross-section conducting wires to shape each of the conducting wires into a polygon in cross section and form a conducting wire assembly; and a second step of heat-treating the conducting wire assembly to form an oxide film on a periphery of each conducting wire and form the element wire assembly that includes a plurality of element wires each of which consists of the conducting wires and the oxide film. [0015] In other words, circular cross-section conducting wires are bunched up and rolled or drawn, a polygonal cross-section conducting wire assembly is first formed, and then the conducting wire assembly is heat-treated, an oxide film is formed on the periphery of each of the conducting wires that constitute the assembly, and an element wire assembly that includes the conducting wires and oxide films is formed. [0016] By bunching up and rolling or drawing the circular cross-section conducting wires to shape the conducting wires into a polygon in cross section and eliminate the clearance between the adjacent conducting wires, and then forming the oxide film on the periphery of the conducting wire, the manufactured element wire assembly has no void or very little voids in its inside, and when the element wire assembly is wound around a tooth to form a coil, the coil with a high space factor can be formed. [0017] The circular cross-section conducting wire used in the first step may be a conducting wire made of copper, for example. Here, the “circular” means the shape of not only a perfect circle but also circles including a polygon approximate to a circle, an ellipse, and a flattened circle. [0018] In addition, the “polygon” that is formed by the deformation of the circular cross-section conducting wire by rolling or drawing in the first step means a rectangle such as a square or an oblong as well as multiangular shapes other than the rectangle. In the method for manufacturing according to the present invention, the shape of the element wire assembly itself that is formed finally is a rectangle. [0019] The cross sectional shapes of all conducting wires are processed to make close contact with each other by rolling or drawing, and therefore the conducting wire assembly without any clearance between the conducting wires can be formed. [0020] In the second step, the conducting wire assembly is heat treated, and therefore the surfaces of all conducting wires constituting the assembly are oxidized, and for example, copper oxide that is the oxide film is formed on the periphery of the conducting wire made of copper. The formed copper oxide has enough electric resistance, and therefore the eddy current loss reduction effect can be expected. [0021] The conducting wire without insulating film on its periphery may be used for the circular cross-section conducting wire before the rolling. [0022] In addition, a second aspect of the present invention relates to the element wire assembly manufactured by the method for manufacturing the same as described above. [0023] Furthermore, in this element wire assembly, the thickness of the oxide film may be 5 nm to 500 nm. [0024] The thickness of the oxide film that is thicker than 500 nm is not preferable because the oxide film itself becomes brittle and is easily broken in processing or when left standing in a market for long period. On the other hand, the thickness of the oxide film thinner than 5 nm is not preferable due to insufficient electric resistance, and therefore the value range of 5 nm to 500 nm has been determined. [0025] In consideration of adhesion durability at high temperatures now, it is further preferable that the thickness of the oxide film be 200 nm or less (Hereinafter, the adhesion durability at high temperatures will be referred to an a high temperature adhesiveness durability). In order to prevent the influence of surface roughness of the conducting wire after rolling or drawing, the thickness of the oxide film is desirably 50 nm or greater. The high temperature adhesiveness durability is measured by heating a copper base-material with the oxide film at a temperature of 200° C. for a specified time, conducting a tape peel experiment with cross-cut at intervals of 1 mm on the oxide film, and determining the presence and absence of peeling-off of the oxide film. If no peeling-off of the oxide film is observed, the high temperature adhesiveness durability is evaluated to be passed. [0026] It can be understood from the above descriptions that, according to the method for manufacturing the element wire assembly and the element wire assembly manufactured by the method for manufacturing the same of the present invention, the circular cross-section conducting wires are bunched up and rolled or drawn, the polygonal cross-section conducting wire assembly is first formed, and then the conducting wire assembly is heat-treated. By heat treatment, the oxide film is formed on the periphery of each of the conducting wires that constitute the assembly, and the element wire assembly that includes the conducting wires and oxide films is formed. In this way, the coil with a high space factor and a superior eddy current loss reduction effect can be formed. BRIEF DESCRIPTION OF THE DRAWINGS [0027] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like element, and wherein: [0028] FIGS. 1A to 1C are flow diagrams that illustrate, in this order, the method for manufacturing the element wire assembly according to the embodiments of the present invention. DETAILED DESCRIPTION OF EMBODIMENTS [0029] A description will hereinafter be made on embodiments of the method for manufacturing the element wire assembly according to the present invention with reference to the drawings. The illustrated example shows one form of the wire assembly in which six conducting wires of circular cross section are bunched up in three columns and two rows and rolled together, and then heat-treated. However, it should be noted that there are various numbers and forms of conducting wires to be bunched up (in two columns and three rows, or five columns and three rows, for example) besides the illustrated example. [0030] (Embodiments of Element Wire Assembly and Method for Manufacturing the Element Wire Assembly) FIGS. 1A to 1C are flow diagrams that illustrate, in this order, the method for manufacturing the element wire assembly according to the embodiments of the present invention. [0031] First, as shown in FIG. 1A , conducting wires 1 that have equal dimensions and are circular in cross section and made of copper are bunched up in three columns and two rows. As a form of “bunch(ing) up” herein, there are the form of simply placing and stacking the conducting wires side by side, the form of placing and stacking the conducting wires side by side and then twisting together, or the form of placing and stacking the conducting wires side by side and then braided together. Preferably, the conducting wires 1 to be used have no insulating films on the periphery. [0032] Next, six circular cross-section conducting wires 1 that are bunched up in three columns and two rows are rolled or drawn, and thus six rectangular cross-section conducting wires 1 ′ are formed as shown in FIG. 1B , which forms a conducting wire assembly 10 (first step). It should be noted that each conducting wire 1 ′ to be processed may have a polygonal shape besides the rectangular shape. [0033] The conducting wire assembly 10 ′ shown in FIG. 1B has a structure in which the conducting wires 1′ of rectangular cross section are arranged in close contact with each other, and therefore the conducting wire assembly 10 has no clearance or very little clearances between the adjacent conducting wires 1 ′. [0034] After the conducting wire assembly 10 is formed in the first step, as shown in FIG. 1C , the entire conducting wire assembly 10 is heat-treated, and the periphery of each conducting wire 1 ′ is oxidized to form an oxide film 2 . Then, an element wire assembly 20 is formed with a set of element wires 3 that include rectangular cross-section conducting wires 1 ′ and oxide films 2 on the periphery (second step). The entire surface of the conducting wire 1 ′ is covered by the oxide films 2 . [0035] According to the method for manufacturing the element wire as shown in FIGS. 1A to 1C , the circular cross-section conducting wires 1 are bunched up to be rolled or drawn, and the conducting wire assembly 10 is formed with a set of rectangular cross-section conducting wires 1 ′ in the first instance. Then, the conducting wire assembly 10 is heat-treated, the oxide films 2 are formed on the periphery of all the conducting wires 1 ′ constituting the assembly 10 , and thus the rectangular element wire assembly 20 is formed with a set of element wires 3 that are provided with the conducting wires 1 ′ and the oxide films 2 . In this way, the assembly for a coil with a high space factor and a superior eddy current loss reduction effect can be fabricated. [0036] [Experiment and the results in which eddy current loss reduction effect could be determined] The inventors of the present invention fabricated the test pieces of element wire assembly according to Examples 1 and 2 and Comparative Examples 1 to 4 as shown in Table 1 below and measured the eddy current loss by using an AC magnetic property test equipment. [0037] (Fabrication Method of Element Wire Assembly of Examples 1 and 2) The used conducting wires (fine wires) of circular cross section were prepared by bunching up and twisting six round solid copper wires (1.1 mm dia.) together. Then, a rectangular conducting wire assembly of 2.0×3.4 mm was formed by using a die and placed in a drying oven. After that, the periphery of the conducting wire was oxidized under a specified condition to form the oxide film, and therefore the element wire assembly was prepared by bunching up and twisting six element wires together that were constituted by the rectangular conducting wires and the oxide films. [0038] (Measuring Method of Eddy Current Loss) The AC magnetic property test equipment (manufactured by METRON, Inc., popularly called a C-Epstein measurement device) was used to measure the alternating-current loss of the element wire assembly. At this time, the magnetic flux having the frequency. of 0 to 2 kHz and the magnetic flux density of ±0.1 T was generated in the test equipment. The loss reduction ratio for any of the test pieces was calculated with respect to the loss in a rectangular bare copper conducting wire of 2.0×3.4 mm. In Example 1, the eddy current loss of the bare conducting wire was 100 W, but it was reduced to 15 W by the oxide film. That is to say, the loss reduction ratio in Example 1 was 85%. [0039] (Details of Test Pieces) <Comparative Example 1> The conducting wires were not oxidized, and the element wire assembly was formed without the oxide films. [0040] <Comparative Example 2> The conducting wires were kept circular in cross section without being rolled and then heat-treated (oxidized) at 250° C. for 10 min. After that, the conducting wires were twisted together and rolled so that each conducting wire had a rectangular shape. [0041] <Comparative Example 3> The circular cross-section conducting wires were twisted together and then heat-treated (oxidized) at 250° C. for 10 min. After that, the conducting wires were rolled so that each conducting wire had a rectangular shape. [0042] <Examples 1 and 2> The element wire assembly was fabricated in accordance with the fabrication method of Examples 1 and 2 described above. [0043] <Comparative Example 4> Six enameled wires (circular cross-section element wires having polyamide-imide films of 1.1 mm dia.) were twisted together and worked with the die so that all the element wires had equal dimensions and the rectangular shape. [0000] TABLE 1 Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 1 Example 2 Example 4 Oxidation No Circular Oxide film Rolling Rolling Element Process oxidation cross-section formation followed followed wire Order conducting followed by oxide by oxide having wire (no by rolling film film enamel oxide film) process formation formation coat Oxidizing — 250° C. 250° C. 250° C. 275° C. — Condition 10 min. 10 min. 10 min. 10 min. Thickness of — 50 nm 50 nm 50 nm 200 nm — Oxide Film Electrical — — — 0.3 Ω    3 Ω — Resistance Loss Reduction 60% 60% 55% 85% 85% 85% Ratio (**) Oxide Film Effect — No No Yes Yes — Space Factor 70% 70% 70% 70% 70% 55% (**) representing eddy current loss reduction effect with respect to the rectangular wire having the same dimensions. [0044] (Consideration) In Examples 1 and 2, the formation of the oxide film by heat treatment is carried out after rolling, and thus the oxide film can uniformly be formed on all the conducting wires. On this account, it is supposed that the loss reduction effect of Examples 1 and 2 is higher than that of Comparative Examples. [0045] In Comparative Examples 2 and 3, the oxide film is formed on the periphery of the conducting wire before rolling and other processes, and thus a part of the oxide film is damaged during twisting or rolling. On this account, it is supposed that the loss reduction effect of Comparative Examples 2 and 3 is lower than that of Examples. [0046] In Comparative Example 4, insulation is fully provided by the enamel coat between the adjacent element wires, and therefore the loss reduction effect of Comparative Example 4 is as high as that of Examples 1 and 2. However, in Comparative Example 4, the space factor is lower than that of Examples 1 and 2. [0047] It was verified by the aforementioned experimental results that the element wire assembly manufactured by the manufacturing method according to the examples of the present invention had a high space factor and superior eddy current loss reduction performance. [0048] While the embodiments of the present invention have been described with reference to the drawings, it is to be understood that the specific constitution is not limited to the described embodiments. When design change or other modification is made without departing from the scope of the invention, such a change is intended to fall within the present invention. For example, the element wire according to the aforementioned examples can be wound on a stator core of the motor, and thus the motor with a high space factor can be produced.

A method for manufacturing an element wire assembly includes: a first step of bunching up and rolling or drawing a plurality of circular cross-section conducting wires ( 1 ) to shape each of the conducting wires into a polygon in cross section and form the conducting wires ( 1′ ) and form a conducting wire assembly ( 10 ); and a second step of heat-treating the conducting wire assembly ( 10 ) to form an oxide film ( 2 ) on the periphery of each of the conducting wires ( 1′ ) to form element wires ( 3 ) and, form an element wire assembly ( 20 ).

CROSS REFERENCE This application is a continuation of U.S. application Ser. No. 12/001,777, filed Dec. 11, 2007, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to methods of blow molding polymeric tubing for stent manufacturing. 2. Description of the State of the Art This invention relates to radially expandable endoprostheses, which are adapted to be implanted in a bodily lumen. An “endoprosthesis” corresponds to an artificial device that is placed inside the body. A “lumen” refers to a cavity of a tubular organ such as a blood vessel. A stent is an example of such an endoprosthesis. Stents are generally cylindrically shaped devices, which function to hold open and sometimes expand a segment of a blood vessel or other anatomical lumen such as urinary tracts and bile ducts. Stents are often used in the treatment of atherosclerotic stenosis in blood vessels. “Stenosis” refers to a narrowing or constriction of the diameter of a bodily passage or orifice. In such treatments, stents reinforce body vessels and prevent restenosis following angioplasty in the vascular system. “Restenosis” refers to the reoccurrence of stenosis in a blood vessel or heart valve after it has been treated (as by balloon angioplasty, stenting, or valvuloplasty) with apparent success. The treatment of a diseased site or lesion with a stent involves both delivery and deployment of the stent. “Delivery” refers to introducing and transporting the stent through a bodily lumen to a region, such as a lesion, in a vessel that requires treatment. “Deployment” corresponds to the expanding of the stent within the lumen at the treatment region. Delivery and deployment of a stent are accomplished by positioning the stent about one end of a catheter, inserting the end of the catheter through the skin into a bodily lumen, advancing the catheter in the bodily lumen to a desired treatment location, expanding the stent at the treatment location, and removing the catheter from the lumen. In the case of a balloon expandable stent, the stent is mounted about a balloon disposed on the catheter. Mounting the stent typically involves compressing or crimping the stent onto the balloon. The stent is then expanded by inflating the balloon. The balloon may then be deflated and the catheter withdrawn. In the case of a self-expanding stent, the stent may be secured to the catheter via a retractable sheath or a sock. When the stent is in a desired bodily location, the sheath may be withdrawn which allows the stent to self-expand. The stent must be able to satisfy a number of mechanical requirements. First, the stent must be capable of withstanding the structural loads, namely radial compressive forces, imposed on the stent as it supports the walls of a vessel. Therefore, a stent must possess adequate radial strength. Radial strength, which is the ability of a stent to resist radial compressive forces, is due to strength and rigidity around a circumferential direction of the stent. Radial strength and rigidity, therefore, may also be described as, hoop or circumferential strength and rigidity. Once expanded, the stent must adequately maintain its size and shape throughout its service life despite the various forces that may come to bear on it, including the cyclic loading induced by the beating heart. For example, a radially directed force may tend to cause a stent to recoil inward. Generally, it is desirable to minimize recoil. In addition, the stent must possess sufficient flexibility to allow for crimping, expansion, and cyclic loading. Longitudinal flexibility is important to allow the stent to be maneuvered through a tortuous vascular path and to enable it to conform to a deployment site that may not be linear or may be subject to flexure. Finally, the stent must be biocompatible so as not to trigger any adverse vascular responses. The structure of a stent is typically composed of scaffolding that includes a pattern or network of interconnecting structural elements often referred to in the art as struts or bar arms. The scaffolding can be formed from wires, tubes, or sheets of material rolled into a cylindrical shape. The scaffolding is designed so that the stent can be radially compressed (to allow crimping) and radially expanded (to allow deployment). A conventional stent is allowed to expand and contract through movement of individual structural elements of a pattern with respect to each other. Additionally, a medicated stent may be fabricated by coating the surface of either a metallic or polymeric scaffolding with a polymeric carrier that includes an active or bioactive agent or drug. Polymeric scaffolding may also serve as a carrier of an active agent or drug. Furthermore, it may be desirable for a stent to be biodegradable. In many treatment applications, the presence of a stent in a body may be necessary for a limited period of time until its intended function of, for example, maintaining vascular patency and/or drug delivery is accomplished. Therefore, stents fabricated from biodegradable, bioabsorbable, and/or bioerodable materials such as bioabsorbable polymers should be configured to completely erode only after the clinical need for them has ended. There are several characteristics that are important for implantable medical devices, such as stents, including high radial strength and good fracture toughness. Some crystalline or semi-crystalline polymers that may be suitable for use in implantable medical devices have potential shortcomings with respect to some of these characteristics, in particular, fracture toughness. SUMMARY OF THE INVENTION Various embodiments of the present invention include a method for fabricating stent comprising: radially deforming a polymer tube for use in fabrication of a stent from the deformed tube, wherein the radial deformation propagates along the tube axis as the tube is heated along the axis, the polymer tube having an internal tube pressure higher than ambient; controlling the propagation rate or the radial deformation rate to provide a selected fracture resistance of a stent fabricated from the tube; and fabricating the stent from the deformed tube. Further embodiments of the present invention include a method for fabricating a stent comprising: radially deforming a polymer tube for use in fabrication of a stent from the deformed tube, wherein the radial deformation propagates along the tube axis as the tube is heated along the axis, the polymer tube having an internal tube pressure higher than ambient; controlling a temperature of the polymer tube to provide a selected fracture resistance of the stent fabricated from the tube; and fabricating the stent from the deformed tube. Additional embodiments of the present invention include a method for fabricating a stent comprising: increasing an internal pressure of a tube to a deformation pressure; translating a heat source along an axis of the polymer tube to heat the tube to a deformation temperature; allowing the tube to radially expand as the heat source translates along the axis of the polymer tube, wherein the heating of the tube and the increase in pressure allow the tube to radially expand; and controlling one or more process parameters to provide a selected fracture resistance a stent fabricated from the tube, wherein the process parameters are selected from the group consisting of the deformation pressure, the translation rate of the heat source, the deformation temperature; and fabricating the stent from the deformed tube. Other embodiments of the present invention include a method for fabricating a stent comprising: determining one or more process parameters of a radial deformation process of a tube to provide a selected fracture resistance of a stent fabricated from the tube, the radial deformation process comprising: increasing an internal pressure of a tube to a deformation pressure; translating a heat source along an axis of the polymer tube to heat the tube to a deformation temperature; allowing the tube to radially expand as the heat source translates along the axis of the polymer tube, wherein the heating of the tube and the increase in pressure allow the tube to radially expand, wherein the process parameters are selected from the group consisting of the deformation pressure, the translation rate of the heat source, the deformation temperature; and fabricating the stent from the deformed tube. Further embodiments of the present invention include a method for fabricating a stent comprising: increasing an internal pressure of a polylactide tube to between 120 psi and 130 psi; translating a heat source along an axis of the polymer tube at a translation rate between 0.5 and 0.7 mm/s to heat the tube to between 190° F. and 210° F.; allowing the tube to radially expand as the heat source translates along the axis of the polymer tube, wherein the heating of the tube and the increase in pressure allow the tube to radially expand; and fabricating the stent from the deformed tube. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a stent. FIG. 2 depicts a tube. FIGS. 3A-3C depict blow molding of a polymeric tube. FIG. 4 depicts a schematic plot of the crystal nucleation rate and the crystal growth rate, and the overall rate of crystallization. FIG. 5 depicts experimental results for the R CG of PLLA. FIG. 6 is a photograph of a stent. FIG. 7 is a graph showing the number of cracks observed in stents made from tubes with different expansion process parameters. DETAILED DESCRIPTION OF THE INVENTION The various embodiments of the present invention relate to methods of fabricating a polymeric stent that have good or optimal toughness and selected mechanical properties along the axial direction or circumferential direction of the stent, or both. The present invention can be applied to devices including, but is not limited to, self-expandable stents, balloon-expandable stents, stent-grafts, and grafts (e.g., aortic grafts). For the purposes of the present invention, the following terms and definitions apply: The “glass transition temperature,” T g , is the temperature at which the amorphous domains of a polymer change from a brittle vitreous state to a solid deformable or ductile state at atmospheric pressure. In other words, the T g corresponds to the temperature where the onset of segmental motion in the chains of the polymer occurs. When an amorphous or semicrystalline polymer is exposed to an increasing temperature, the coefficient of expansion and the heat capacity of the polymer both increase as the temperature is raised, indicating increased molecular motion. As the temperature is raised the actual molecular volume in the sample remains constant, and so a higher coefficient of expansion points to an increase in free volume associated with the system and therefore increased freedom for the molecules to move. The increasing heat capacity corresponds to an increase in heat dissipation through movement. T g of a given polymer can be dependent on the heating rate and can be influenced by the thermal history of the polymer. Furthermore, the chemical structure of the polymer heavily influences the glass transition by affecting mobility. “Stress” refers to force per unit area, as in the force acting through a small area within a plane. Stress can be divided into components, normal and parallel to the plane, called normal stress and shear stress, respectively. Tensile stress, for example, is a normal component of stress applied that leads to expansion (increase in length). In addition, compressive stress is a normal component of stress applied to materials resulting in their compaction (decrease in length). Stress may result in deformation of a material, which refers to a change in length. “Expansion” or “compression” may be defined as the increase or decrease in length of a sample of material when the sample is subjected to stress. “Strain” refers to the amount of expansion or compression that occurs in a material at a given stress or load. Strain may be expressed as a fraction or percentage of the original length, i.e., the change in length divided by the original length. Strain, therefore, is positive for expansion and negative for compression. “Modulus” may be defined as the ratio of a component of stress or force per unit area applied to a material divided by the strain along an axis of applied force that results from the applied force. For example, a material has both a tensile and a compressive modulus. “Stress at peak” is the maximum tensile stress which a material will withstand prior to fracture. Stress at break can also be referred to as the tensile strength. The stress at break is calculated from the maximum load applied during a test divided by the original cross-sectional area. “Stress at break” is the tensile stress of a material at fracture. “Toughness” is the amount of energy absorbed prior to fracture, or equivalently, the amount of work required to fracture a material. One measure of toughness is the area under a stress-strain curve from zero strain to the strain at fracture. The stress is proportional to the tensile force on the material and the strain is proportional to its length. The area under the curve then is proportional to the integral of the force over the distance the polymer stretches before breaking. This integral is the work (energy) required to break the sample. The toughness is a measure of the energy a sample can absorb before it breaks. There is a difference between toughness and strength. A material that is strong, but not tough is said to be brittle. Brittle substances are strong, but cannot deform very much before breaking. A stent can have a scaffolding or a substrate that includes a pattern of a plurality of interconnecting structural elements or struts. FIG. 1 depicts an example of a view of a stent 100 . Stent 100 has a cylindrical shape with an axis 160 and includes a pattern with a number of interconnecting structural elements or struts 110 . In general, a stent pattern is designed so that the stent can be radially compressed (crimped) and radially expanded (to allow deployment). The stresses involved during compression and expansion are generally distributed throughout various structural elements of the stent pattern. The present invention is not limited to the stent pattern depicted in FIG. 1 . The variation in stent patterns is virtually unlimited. The underlying structure or substrate of a stent can be completely or at least in part made from a biodegradable polymer or combination of biodegradable polymers, a biostable polymer or combination of biostable polymers, or a combination of biodegradable and biostable polymers. Additionally, a polymer-based coating for a surface of a device can be a biodegradable polymer or combination of biodegradable polymers, a biostable polymer or combination of biostable polymers, or a combination of biodegradable and biostable polymers. A stent such as stent 100 may be fabricated from a polymeric tube or a sheet by rolling and bonding the sheet to form a tube. For example, FIG. 2 depicts a tube 200 . Tube 200 is cylindrically-shaped with an outside diameter 205 and an inside diameter 210 . FIG. 2 also depicts an outside surface 215 and a cylindrical axis 220 of tube 200 . In some embodiments, the diameter of the polymer tube prior to fabrication of an implantable medical device may be between about 0.2 mm and about 5.0 mm, or more narrowly between about 1 mm and about 3 mm. Polymeric tubes may be formed by various types of methods, including, but not limited to extrusion or injection molding. A stent pattern may be formed on a polymeric tube by laser cutting a pattern on the tube. Representative examples of lasers that may be used include, but are not limited to, excimer, carbon dioxide, and YAG. In other embodiments, chemical etching may be used to form a pattern on a tube. The pattern of stent 100 in FIG. 1 varies throughout its structure to allow radial expansion and compression and longitudinal flexure. A pattern may include portions of struts that are straight or relatively straight, an example being a portion 120 . In addition, patterns may include bending elements 130 , 140 , and 150 . Bending elements bend inward when a stent is crimped to allow radial compression. Bending elements also bend outward when a stent is expanded to allow for radial expansion. After deployment, a stent is under static and cyclic compressive loads from the vessel walls. Thus, bending elements are subjected to deformation during use. “Use” includes, but is not limited to, manufacturing, assembling (e.g., crimping stent on a catheter), delivery of stent into and through a bodily lumen to a treatment site, and deployment of stent at a treatment site, and treatment after deployment. Additionally, stent 100 is subjected to flexure along axis 160 when it is maneuvered through a tortuous vascular path during delivery. Stent 100 is also subjected to flexure when it has to conform to a deployment site that may not be linear. There are several mechanical properties that are important for a stent. These include high radial strength, adequate toughness, low recoil, and resistance to physical aging. A stent must have adequate strength, particularly, in the radial direction to withstand structural loads, namely radial compressive forces, imposed on the stent as it supports the walls of a vessel. Radial strength is associated with strength of the stent around the circumferential direction of the stent. In addition, the stent must possess sufficient toughness so that the stent exhibits sufficient flexibility to allow for crimping, expansion, and flexure. A stent should have sufficient toughness so that it is resistant to crack formation, particularly, in high strain regions. Recoil refers to the retraction of a stent radially inward from its deployed diameter. A stent can be made in whole or in part of a biodegradable polymer. A biodegradable stent can be configured erode away from an implant site when it is no longer needed. A biodegradable stent allows further surgery or intervention, if necessary, on a treated vessel and reduces the likelihood of late stent thrombosis, a condition in which clots form on the surface of the stent months or years after deployment. Some crystalline or semi-crystalline biodegradable polymers that are glassy or have a glass transition temperature (Tg) above body temperature are particularly attractive as stent materials due to their strength and stiffness at physiological conditions. Such glassy polymers can be absorbed through chemical degradation, such as hydrolysis. Physiological conditions refer to conditions that an implant is exposed to within a human body. Physiological conditions include, but are not limited to, human body temperature, approximately 37° C. However, the mechanical properties of such polymers may require improvement to be suitable as stent materials. For example, the struts of stent may have to be undesirably large to have radial strength sufficient to support the walls of a vessel. Therefore, the strength of such polymers may need improvement. Additionally, the toughness of such polymers can be lower than desired, in particular, for use in stent applications. For example, polymers such as poly(L-lactide) (PLLA) are stiff and strong, but tend to be brittle under physiological conditions. These polymers can exhibit a brittle fracture mechanism at physiological conditions in which there is little or no plastic deformation prior to failure. A stent fabricated from such polymers can have insufficient toughness for the range of use of a stent. As a result, cracks, particularly in high strain regions, can be induced which can result in mechanical failure of the stent. Furthermore, recoil can result from creep and stress relaxation which result from relaxation or rearrangement of polymer chains. Creep refers to the gradual deformation that occurs in a polymeric construct subjected to an applied load. Stress relaxation occurs when deformation (or strain) is constant and is manifested by a reduction in the force (stress) required to maintain a constant deformation Physical aging can also be a problem with such semicrystalline polymers. Physical aging, as used herein, refers to densification in the amorphous regions of a semi-crystalline polymer. Densification is the increase in density of a material or region of a material and results from reordering of polymer chains. Densification tends to decrease the fracture toughness of a polymer. In general, the mechanical properties of a polymer depend upon its morphology or microstructure. Various embodiments of the present invention include processing a polymeric construct that is a precursor to a stent to obtain desirable or selected mechanical properties of the stent. Such desirable or selected mechanical properties can correspond to a particular structure or morphology. Embodiments of the present invention include adjusting the processing conditions to obtain selected or desirable properties. Morphology includes, but is not limited to, crystallinity, molecular orientation of polymer chains, and crystal size. A polymer may be completely amorphous, partially crystalline, or almost completely crystalline. A partially crystalline polymer includes crystalline regions separated by amorphous regions. The degree of crystallinity is the sum of all the crystalline regions. Molecular orientation refers to the relative orientation of polymer chains along a longitudinal or covalent axis of the polymer chains. The orientation can refer to both the orientation of polymer chains the crystalline regions and the amorphous regions. The relationship between the morphology and mechanical properties can be of use in alleviating some of the shortcomings of the semi-crystalline polymers mentioned above. In general, the modulus of a polymer increases as crystallinity increases. As mentioned above, a semi-crystalline polymer with a high degree of crystallinity can be brittle and is susceptible to cracking. An amorphous polymer may be more flexible or ductile, but may have insufficient radial strength. Additionally, the size of crystalline regions in a polymer can affect mechanical properties. It is believed that decreasing the size of crystalline regions or domains while maintaining a degree of crystallinity in a polymer increases the fracture toughness of the polymer. Furthermore, the strength and toughness of a polymer can be affected by the orientation of polymer chains. The toughness of a semi-crystalline polymer can be increased by inducing orientation of polymer chains in both the crystalline and amorphous regions. In addition, the strength of the polymer is also increased along the direction of preferred orientation. It is believed that crystalline domains can act as net points to tie polymer chains in the amorphous regions between the domains. Smaller domains at a given degree of crystallinity result in a greater number of domains and tie molecules, resulting in increased toughness. The strength and toughness of the amorphous regions can be further be increased by inducing orientation in the amorphous regions. It is expected that a higher number of net points and tie molecules with induced orientation can lead to higher strength and fracture toughness. Certain embodiments of the present invention include processing a stent precursor construct, such as a polymer tube, to modify the morphology of the polymer in the construct so that the construct has desired or selected properties. It is well known by those skilled in the art that the mechanical properties of a polymer can be modified by applying stress to a polymer. James L. White and Joseph E. Spruiell, Polymer and Engineering Science, 1981, Vol. 21, No. 13. The application of stress can induce molecular orientation along the direction of stress which can modify mechanical properties along the direction of applied stress. Induced orientation in constructs such as polymer tubes can be particularly useful since tubes formed by extrusion tend to possess no or substantially no polymer chain alignment in the circumferential direction. A tube made from injection molding has a relatively low degree of polymer chain alignment in both the axial and circumferential directions. In certain embodiments, the processing of the stent precursor construct can include deformation of a polymer tube radially, axially, or both to obtain selected or desirable mechanical properties. The processing can modify structural or morphological characteristics of the polymeric construct including crystallinity, crystal size, and molecular orientation. The processing can include radially deforming a polymer tube through application of an outwardly directed radial force. The radial force can be from an internal pressure of a fluid in the tube that is above ambient pressure. Ambient pressure corresponds to the pressure outside of the tube which is typically at or near atmospheric pressure. Furthermore, the deformation can be facilitated by heating the tube prior to the deformation. Additionally, the tube can also be heated prior to and during the deformation of the tube. In some embodiments, the tube can be heated to a temperature above the Tg of the polymer of the tube. In further embodiments, the polymeric tube can be axially deformed or stretched. The tube can be axially deformed by applying a tensile force at one end with the other end fixed or applying a tensile force at both ends. The temperature of the tube can be increased to a deformation temperature prior to the deformation of the tube and maintained at the deformation temperature during deformation. The deformation temperature may be in a range at or slightly below the Tg of the polymer of the tube to the melting temperature of the polymer of the tube. “Slightly below” the Tg can refer to temperatures of 5% below the Tg to the Tg of the polymer. The temperature of the tube can also be increased at a constant or nonlinear rate during deformation. The degree of radial expansion, and thus induced radial orientation and strength, of a tube can be quantified by a radial expansion (RE) ratio: Inside ⁢ ⁢ Diameter ⁢ ⁢ of ⁢ ⁢ Expanded ⁢ ⁢ Tube Original ⁢ ⁢ Inside ⁢ ⁢ Diameter ⁢ ⁢ of ⁢ ⁢ Tube The RE ratio can also be expressed as a percent expansion: % Radial expansion=(RE ratio−1)×100% Similarly, the degree of axial extension, and thus induced axial orientation and strength, may be quantified by an axial extension (AE) ratio: Length ⁢ ⁢ of ⁢ ⁢ Extended ⁢ ⁢ Tube Original ⁢ ⁢ Length ⁢ ⁢ of ⁢ ⁢ Tube The AE ratio can also be expressed as a percent expansion: % Axial expansion=(AE ratio−1)×100% In further embodiments, the deformed tube can be heat set or annealed while the tube is maintained in the deformed state. In such embodiments, the internal pressure in the tube or the axial tension can be at levels that maintain the tube in the deformed state. The deformed tube can also be maintained at the deformation temperature or at a temperature above or below the deformation temperature. The heat setting or annealing can release internal stresses in the polymer. In addition, the heat setting or annealing allows crystallization to continue resulting in further increasing of the crystallinity. During the heat setting or annealing, the polymer chains are allowed to rearrange to approach an equilibrated configuration, relieving internal stresses. Additionally, the deformed tube may then be cooled. The tube can be cooled slowly from above Tg to below Tg. Alternatively, the tube can be cooled quickly or quenched below Tg to an ambient temperature. The tube can be maintained at the deformed diameter during cooling. In certain embodiments of the present invention, a polymeric tube may be deformed by blow molding. A balloon blowing apparatus may be adapted to radially deform a polymer tube. In blow molding, a tube can be deformed radially by conveying a fluid into the tube which increases the internal pressure in the tube. The polymer tube may be deformed axially by applying a tensile force by a tension source at one end while holding the other end stationary. Alternatively, a tensile force may be applied at both ends of the tube. The tube may be axially extended before, during, and/or after radial expansion. In some embodiments, blow molding may include first positioning a tube in a cylindrical member or mold. The mold controls the degree of radial deformation of the tube by limiting the deformation of the outside diameter or surface of the tube to the inside diameter of the mold. The inside diameter of the mold may correspond to a diameter less than or equal to a desired diameter of the polymer tube. Alternatively, the fluid temperature and pressure may be used to control the degree of radial deformation by limiting deformation of the inside diameter of the tube as an alternative to or in combination with using the mold. As indicated above, the temperature of the tube can be heated to temperatures above the Tg of the polymer during deformation. The polymer tube may also be heated prior to, during, and subsequent to the deformation. In some embodiments, the tube may be heated by translating a heating source along the cylindrical axis of the tube. As the heat source translates and heats the tube, the radial deformation propagates along the axis of the tube. In other embodiments, in addition to the heat source, the tube may be heated by the mold or the fluid conveyed into the tube to expand the tube. The mold may be heated, for example, by heating elements on, in, and/or adjacent to the mold. Certain embodiments may include first sealing, blocking, or closing a polymer tube at a distal end. The end may be open in subsequent manufacturing steps. The fluid, (conventionally a gas such as air, nitrogen, oxygen, argon, etc.) may then be conveyed into a proximal end of the polymer tube to increase the pressure in the tube. The pressure of the fluid in the tube may radially expand the tube. Additionally, the pressure inside the tube, the tension along the cylindrical axis of the tube, and the temperature of the tube may be maintained above ambient levels for a period of time to allow the polymer tube to be heat set. Heat setting may include maintaining a tube at a temperature greater than or equal to the Tg of the polymer and less than the Tm of the polymer for a selected period to time. The selected period of time may be between about one minute and about two hours, or more narrowly, between about two minutes and about ten minutes. The polymer tube may then be cooled to below its Tg either before or after decreasing the pressure and/or decreasing tension. Cooling the tube helps insure that the tube maintains the proper shape, size, and length following its formation. Upon cooling, the deformed tube retains the length and shape imposed by an inner surface of the mold. FIGS. 3A-C depict a schematic blow molding system 300 which illustrates deforming a polymer tube with blow molding. In some embodiments, a polymer tube for use in manufacturing stent can have a diameter of 1-3 mm. However, the present invention is applicable to polymer tubes less than 1 mm or greater than 3 mm. The wall thickness of the polymer tube can be 0.03-0.06 mm, however, the present invention is application to tubes with a wall thickness less than 0.03 mm and greater than 0.06 mm. FIG. 3A depicts an axial cross-section of a polymer tube 301 with an undeformed outside diameter 305 positioned within a mold 310 . Mold 310 limits the radial deformation of polymer tube 301 to a diameter 315 , the inside diameter of mold 310 . Polymer tube 301 may be closed at a distal end 320 . Distal end 320 may be open in subsequent manufacturing steps. A fluid may be conveyed, as indicated by an arrow 325 , into an open proximal end 321 of polymer tube 301 to increase an internal pressure within tube 301 to radially deform tube 301 . A tensile force can be applied at proximal end 321 , a distal end 320 , or both. Polymer tube 301 is heated by a nozzle 330 with fluid ports that direct a heated fluid at two circumferential locations of tube 310 , as shown by arrows 335 and 340 . FIG. 3B depicts a radial cross-section showing tube 301 , mold 310 , and nozzle 330 having structural members 360 . Additional fluid ports can be positioned at other circumferential locations of tube 310 . The heated fluid flows around tube 301 , as shown by arrows 355 , to heat mold 310 and tube 301 to a temperature above ambient temperature. Nozzle 330 translates along the longitudinal axis of tube 310 as shown by arrows 365 and 367 . As nozzle 330 translates along the axis of mold 310 , tube 301 radially deforms. The increase in temperature of tube 301 and the increased pressure cause deformation of tube 301 , as depicted in FIG. 3C . FIG. 3C depicts system 300 with a deforming section 372 and deformed section 370 of tube 301 . Section 372 deforms radially as shown by an arrow 380 . Deformed section 370 has an outside diameter the same as the inside diameter of mold 310 . Processing parameters of the above-described deformation process include, but are not limited to, the deformation temperature, deformation pressure (or force), nozzle translation rate, heat setting temperature, and the time of heat setting. It is expected that the deformation rate depends at least upon the deformation pressure, deformation temperature, and heat source or nozzle translation rate. The deformation rate has both a radial component in the radial direction and an axial component corresponding to the propagation rate of the radial deformation along the axis of the tube. The deformation in the radial direction is shown by arrow 380 in FIG. 3C and the axial component is shown by an arrow 382 in FIG. 3C . It is expected that the radial deformation rate has a greater dependence on the deformation pressure and the axial component has a greater dependence on the translation rate of the heat source along the axis of the tube. Since deformation of a polymer is a time dependent process, it is expected that the deformation rate will also affect the morphology and structure of the deformed polymer. The morphology and consequently the mechanical properties of the deformed tube are expected to depend upon the processing parameters. Embodiments of the present invention include determining or optimizing processing parameters of a blow molding process of a polymer tube. In such embodiments, the processing parameters are determined or optimized to achieve or provide desired mechanical properties of a stent fabricated from the blow molded or deformed tube. In some embodiments, the processing parameters can be determined or optimized to obtain a selected morphology of the polymer of the deformed tube that provides the desired mechanical properties. Additionally, in such embodiments, the processing parameters include, but are not limited to, the deformation temperature, deformation pressure, and nozzle speed. Further embodiments of the present invention include controlling, adjusting, or modifying processing parameters of a blow molding process of a polymer tube that provide the desired mechanical properties. In these embodiments, a stent may then be fabricated from the blow molded tube. In some embodiments, the processing parameters that provide desired mechanical properties can be determined or optimized by blow molding two or more tubes. One or more the processing parameters can be varied so that two or more tubes are blow molded with at least one different processing parameter. Stents can then be fabricated from the tubes and the mechanical properties and performance determined for the stents using known testing techniques. For example, the radial strength and modulus can be determined. The toughness and fracture resistance can be evaluated by examining the fracture and breaking of struts when the stents are expanded to a deployment diameter or greater than a deployment diameter. Additionally, the morphology (e.g., crystallinity, molecular orientation of polymer chains, and crystal size) of the tubes can be determined by known testing techniques, as discussed in examples below. Furthermore, the desired mechanical properties can include high radial strength, high toughness, high modulus, and low recoil. A polymer stent fabricated from the polymer tube can have a high resistance to failure upon expansion of the stent. The high resistance to failure can be demonstrated by few or no cracks in struts of a stent or no broken struts upon expansion of the stent to a deployment diameter. In such embodiments, the processing parameters can be modified to change the morphological characteristics, such as crystallinity, molecular orientation of polymer chains, and crystal size. In certain embodiments, the axial propagation rate, the radial deformation rate, the deformation temperature, or any combination thereof can be optimized and controlled to provide selected or desired mechanical properties of a stent such as selected fracture resistance. In such embodiments, the axial propagation rate or the radial deformation rate can be controlled or adjusted by the deformation pressure, heat source translation rate, or a combination thereof. The temperature of the deformation process can be used to control the degree of crystallinity and the size of the crystalline domains. In general, crystallization tends to occur in a polymer at temperatures between Tg and Tm of the polymer. The rate of crystallization in this range varies with temperature. FIG. 4 depicts a schematic plot of the crystal nucleation rate (R N ), the crystal growth rate (R CG ), and the overall rate of crystallization (R CO ). The crystal nucleation rate is the growth rate of new crystals and the crystal growth rate is the rate of growth of formed crystals. The overall rate of crystallization is the sum of curves R N and R CG . In certain embodiments, the temperature of the tube during deformation can be controlled to have a crystallization rate that provides a selected degree of crystallization and crystal size distribution. In some embodiments, the temperature can be in a range in which the crystal nucleation rate is larger than the crystal growth rate. For example, as shown in FIG. 4 , the temperature can be in a range as shown by “X”. In such embodiments, the temperature can be in a range at which the crystal nucleation rate is relatively high and the crystal growth rate is relatively low. For example, the temperature can be in a range where the ratio of the crystal nucleation rate to crystal growth rate is 2, 5, 10, 50, 100, or greater than 100. In exemplary embodiments, the temperature can be from about Tg to about 0.6(Tm−Tg)+Tg or from about Tg to about 0.9(Tm−Tg)+Tg. Under these conditions, the resulting polymer can have a relatively large number of crystalline domains that are relatively small. As the size of the crystalline domains decreases along with an increase in the number of domains, the fracture toughness of the polymer can be increased reducing or minimizing brittle behavior. By deforming and the polymer tube as described, the size of the crystals can range from less than about 15, less than about 10, less than about 6, less than about 2, or less than about 1 micron. FIG. 5 depicts experimental results for the R CG of PLLA. (Eur. Polymer Journal, 2005) At lower temperatures, there is fast nucleation rate and slow crystal growth rate and at higher temperatures, there is slow nucleation rate and fast crystal growth. In certain embodiments, the processing parameters can be modified to obtain a morphology corresponding to an amorphous structure having relatively small crystalline domains with polymer chains having a high degree of orientation. The size of the crystalline domains can be minimized by adjusting a temperature in the range X shown in FIG. 4 . A pressure and nozzle speed can also be adjusted to obtain the desired mechanical properties. As shown in the examples below, the deformation pressure and nozzle speed can be adjusted to increase the strength and toughness of the deformed polymer tube. Polymers can be biostable, bioabsorbable, biodegradable or bioerodable. Biostable refers to polymers that are not biodegradable. The terms biodegradable, bioabsorbable, and bioerodable are used interchangeably and refer to polymers that are capable of being completely degraded and/or eroded when exposed to bodily fluids such as blood and can be gradually resorbed, absorbed, and/or eliminated by the body. The processes of breaking down and eventual absorption and elimination of the polymer can be caused by, for example, hydrolysis, metabolic processes, bulk or surface erosion, and the like. It is understood that after the process of degradation, erosion, absorption, and/or resorption has been completed, no part of the stent will remain or in the case of coating applications on a biostable scaffolding, no polymer will remain on the device. In some embodiments, very negligible traces or residue may be left behind. For stents made from a biodegradable polymer, the stent is intended to remain in the body for a duration of time until its intended function of, for example, maintaining vascular patency and/or drug delivery is accomplished. Representative examples of polymers that may be used to fabricate or coat an implantable medical device include, but are not limited to, poly(N-acetylglucosamine) (Chitin), Chitosan, poly(hydroxyvalerate), poly(lactide-co-glycolide), poly(hydroxybutyrate), poly(hydroxybutyrate-co-valerate), polyorthoester, polyanhydride, poly(glycolic acid), poly(glycolide), poly(L-lactic acid), poly(L-lactide), poly(D,L-lactic acid), poly(D,L-lactide), poly(caprolactone), poly(trimethylene carbonate), polyester amide, poly(glycolic acid-co-trimethylene carbonate), co-poly(ether-esters) (e.g. PEO/PLA), polyphosphazenes, biomolecules (such as fibrin, fibrinogen, cellulose, starch, collagen and hyaluronic acid), polyurethanes, silicones, polyesters, polyolefins, polyisobutylene and ethylene-alphaolefin copolymers, acrylic polymers and copolymers other than polyacrylates, vinyl halide polymers and copolymers (such as polyvinyl chloride), polyvinyl ethers (such as polyvinyl methyl ether), polyvinylidene halides (such as polyvinylidene chloride), polyacrylonitrile, polyvinyl ketones, polyvinyl aromatics (such as polystyrene), polyvinyl esters (such as polyvinyl acetate), acrylonitrile-styrene copolymers, ABS resins, polyamides (such as Nylon 66 and polycaprolactam), polycarbonates, polyoxymethylenes, polyimides, polyethers, polyurethanes, rayon, rayon-triacetate, cellulose, cellulose acetate, cellulose butyrate, cellulose acetate butyrate, cellophane, cellulose nitrate, cellulose propionate, cellulose ethers, and carboxymethyl cellulose. Another type of polymer based on poly(lactic acid) that can be used includes graft copolymers, and block copolymers, such as AB block-copolymers (“diblock-copolymers”) or ABA block-copolymers (“triblock-copolymers”), or mixtures thereof. Additional representative examples of polymers that may be especially well suited for use in fabricating or coating an implantable medical device include ethylene vinyl alcohol copolymer (commonly known by the generic name EVOH or by the trade name EVAL), poly(butyl methacrylate), poly(vinylidene fluoride-co-hexafluororpropene) (e.g., SOLEF 21508, available from Solvay Solexis PVDF, Thorofare, N.J.), polyvinylidene fluoride (otherwise known as KYNAR, available from ATOFINA Chemicals, Philadelphia, Pa.), ethylene-vinyl acetate copolymers, and polyethylene glycol. EXAMPLES The examples and experimental data set forth below are for illustrative purposes only and are in no way meant to limit the invention. The following examples are given to aid in understanding the invention, but it is to be understood that the invention is not limited to the particular materials or procedures of examples. Example 1 The following example describes the adjusting or optimizing of morphology and mechanical properties of expanded PLLA tubes. A commercially available balloon blower or expander was used for radially expanding the polymer tubes. The expander was modified to allow change in morphology at different process conditions. The modified expander includes a displacement control function. The displacement control function allows fabrication of samples of expanded tubing with different mechanical properties from the same source or lot of extruded tubing. The effect of three process parameters on the morphology of the polymer tube and mechanical properties of stents was studied. These parameters include the deformation temperature, deformation pressure, and nozzle speed. Tubes were deformed using two different values for each parameter to examine influence of the parameters and different combinations of values of parameters on the properties of the tubes and stents. Deformation runs using three combinations of these values were performed to determine optimal values and combinations for the parameter values. Table 1 lists the values of the deformation temperature and the relative deformation pressure and speed. High and low temperature and pressures and a slow and fast nozzle speeds were used. The different parameter values are expected to provide different crystallization rates, radial deformation rates, and axial deformation rates. The high temperature provides a higher crystallization rate compared to the low temperature. The high pressure provides a higher radial deformation rate compared to the low pressure. The fast nozzle speed provides a higher axial deformation rate than the slow nozzle speed. TABLE 1 Values of deformation temperature and deformation pressure Temp (° F.) Relative Pressure Relative Speed 200 low slow 300 high fast Tubes were deformed using three different combinations or options of the parameter values shown in Table 1. Table 2 lists the three combinations of the processing parameter values. TABLE 2 Combinations or options of processing parameters. Option Temp Pressure Speed 1 High High Fast 2 Low High Slow 3 Low Low Slow Polymer tubes were deformed at the processing conditions for each option. The tubes were then made into stents for mechanical testing. FIG. 6 is a photograph of a stent having the pattern of the stent used in the testing. The stents were designed for 3.0 mm deployment. Stents were aged by heat-setting in an oven at 40° C. for 16 hours. Stent were deployed to 3.5 mm and 4.0 mm in order to induce failure during testing. This testing technique allows the observation of stent failure early at extreme conditions. The stents were fabricated from tubes with the same dimension of expanded tubing, with different processing conditions used to expand the tubes. The toughness of the stents were assessed through comparison of the number of cracks observed in the stent samples at zero time point when deployed at diameters of 3.5 mm and 4 mm. FIG. 7 is a graph showing the number of cracks observed in stents made from tubes processed using options 2 and 3. Two different crack size ranges were determined: “>25%” refers to cracks greater than 25% of the strut width. “>50%” refers to cracks greater than 50% of the strut width. As shown in FIG. 7 , the number of cracks for option 3 stents for each crack size is less than the corresponding crack size for option 2 stents. Table 3 shows crack data for stents made from tubes processed with option 1 and option 2 parameters. The results for four stents at each option are shown. Table 3 shows that for stents deployed to 3.5 mm, the cumulative number of cracks for option 2 stents at each crack number range is less than for option 1 stents. No broken struts were observed at 3.5 mm for any of the stents tested. The option 1 stents had more broken struts at 4 mm deployment than the option 2 stents. TABLE 3 Crack counts for stents made from tubes processed with option 1 (300° F.) and option 2 (200° F.) processing parameters. Crack Crack Broken Broken Expansion >25% at >50% at Strut at Strut at Stent Temp (° F.) 3.5 mm 3.5 mm 3.5 mm 4.0 mm B-1 200 0 0 0 0 B-2 200 2 0 0 2 B-3 200 0 0 0 0 B-4 200 2 0 0 0 C-1 300 4 2 0 10 C-2 300 4 1 0 7 C-3 300 2 1 0 4 C-4 300 3 1 0 5 Table 4 summarizes the comparison of the three processing options shown in Table 2. As shown, option 3 provides the best mechanical performance which is demonstrated in FIG. 7 and Table 3. The appearance of the deformed tubes is also affected by processing conditions. Option 3 parameters result in a tube having a clear appearance. It is believed that option 3 provides the best mechanical performance in part because the lower temperature results in the formation of a greater number of smaller crystalline domains. Additionally, option 3 is better because the slower deformation rate facilitates the development of an oriented molecular structure with reduced internal stresses. TABLE 4 Summary of results for options 1, 2, and 3. Stent Morphology Option Temp Pressure Speed Appearance Performance Development 1 High High Fast Clear Worse Faster crystallization temp. Faster deformation Higher crystallinity, lower amorphous orientation 2 Low High Slow Hazy Better Faster deformation in radial direction Lower crystallization rate 3 Low Low Slow Clear Best Slower deformation rate Lower crystallization rate Example 2 Table 5 depicts desirable processing conditions for expanding a tube that provide good stent performance for three stent materials. The first material is 100% PLLA. The second is a PLLA/elastomeric polymer blend that includes PLLA with a dispersed elastomeric block copolymer to increase toughness. The elastomeric copolymer is (CL-co-GA)-b-PLLA. The (CL-co-GA) blocks form a dispersed elastomeric phase and the PLLA block increases adhesion between the PLLA matrix and the elastomeric phase. The third material is the polymer blend with dispersed bioceramic nano-particles. TABLE 5 Desirable tube expansion parameters for three stent materials. Temp Pressure Speed Stent Run (° F.) (psi) (mm/s) Appearance Performance Polymer 1 200 ± 20 130 ± 20 0.6 Clear Good 100% PLLA 2 190 ± 10 120 ± 20 0.6 Hazy Good PLLA/Elastomeric copolymer Blend 3 190 ± 10 120 ± 20 0.6 Hazy Good PLLA/Elastomeric copolymer/nano-particles Example 3 The following example describes a study on the effect of deformation temperature on morphology for expanded PLLA tubes. Table 6 lists the four samples that were studied. Stent samples 1 and 4 were made from tubes expanded at 200° F. and samples 2 and 3 were made from tubes expanded at 300° F. TABLE 6 Tube dimension, expansion ratio and appearance of stent samples. Before Expansion After Expansion ID OD ID OD RE % Appearance #1 0.017 0.0565 0.073 0.0845 300% Transparent #2 0.016 0.06 0.082 0.094 412% Turbid #3 0.014 0.06 0.082 0.094 486% Turbid #4 0.024 0.074 0.125 0.137 421% Turbid Differential scanning calorimetry (DSC) was used to determine the crystallinity of each of the samples. Table 7 lists the enthalpy of crystallization, enthalpy of melting, and % crystallinity for each sample. As expected, the % crystallinity is lower for samples 1 and 4 than for samples 2 and 3 due the higher crystal growth rate at the higher temperature. TABLE 7 DSC results for expanded tubing. ∇Hc (J/g) ∇Hm (J/g) Xc (%) #1 3.332 51.17 51.4% #2 1.285 49.87 52.2% #3 0.8725 49.85 52.7% #4 1.576 48.19 50.1% Wide angle x-ray scattering (WAXS) was used to determine the crystal size in the expanded tubes. The tube samples were scanned both horizontally along the tube axis and vertically perpendicular to the tube axis. Table 8 shows the results of the WAXS for the four stent samples. As expected, samples 1 and 4 had smaller crystal sizes than samples 2 and 3 since the crystal growth rate is smaller at the lower temperature. Table 8. Crystal Size of samples from X-ray Crystal Sample Linewidth 2θ size/nm #1 H 0.83261 16.456 9.95 V 0.7590 16.414 10.9 #2 H 0.58275 16.457 14.2 V 0.49191 16.477 16.8 #3 H 0.60212 16.509 13.8 V 0.56963 16.546 14.5 #4 H 0.95572 16.427 8.67 V 0.73321 16.478 11.3 While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications can be made without departing from this invention in its broader aspects. Therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit and scope of this invention.

Methods to expand polymer tubing with desirable or optimum morphology and mechanical properties for stent manufacture and fabrication of a stent therefrom are disclosed.

TECHNICAL FIELD [0001] The present invention relates to a method and device for taking up fish from a body of water for slaughtering, control, scientific examination, treatment and/or transfer to a net cage, transport container or the like. A specific embodiment of the invention relates to fish farming. BACKGROUND ART [0002] Fish is often held in net cages in industrial farming in coastal districts. The mostly used net cages comprises a ring formed floater onto which a fastened to define and enclosure for the fish to be cultured therein. The fish is kept at a relatively high density in the net cage and has to be treated to avoid parasites, such as salmon louse and other illnesses at planned intervals or according to the need thereof. The treatment may be performed by taking up the fish for injections, or by covering the net cage by means of an outer bag shaped impermeable tarpaulin or the like, and mixing in chemicals for treatment of the fish into the water inside of the tarpaulin. [0003] Both for taking up fish and for treatment inside the net cage covered by an impermeable tarpaulin or the like, the volume inside of the net cage has to be reduced to further increase the density of the fish inside the net cage. This is done by partly lifting up the net cage to reduce the volume thereof. The lifting of the net cage requires lifting equipment as cranes and the like that are expensive in use and exposes the net cage for physical stress that may damage the equipment. The reduction of volume may cause stress with the fishes inside the net cage, and even physical damage to the fish due to the increased fish density. [0004] Normally, specialized pumps are used for taking up the fish. The pumps do also expose the fish for further physical damage and further stress, which may also result in increased mortality. If the fish is taken up for slaughtering, the physical damage and stress may have effect on the quality of the fish and thus the sales value thereof. [0005] For in situ treatment against e.g. salmon louse using an impermeable tarpaulin or the like outside the net cage, time is an important issue as the chemical used are poisonous to the fish by long time exposure, and as the tarpaulin reduces or even stops the introduction of fresh oxygen rich water into the net cage. The treatment time is a compromise between obtaining a sufficient treatment time and reducing the poisoning and/or drowning (i.e. dying due to lack of oxygen) of the fish to a minimum. [0006] Methods and allowing migrating fishes between waters separated from each other's, or where waterfalls prevents fish from swimming upstream, are known from the prior art. [0007] Salmon ladders are well known ways for providing a way for e.g. salmon and trout to pass dams and waterfalls that are too high to pass. A salmon ladder normally comprises several small dams connected by small waterfalls that may be passed upstream by the fish. SE527974 relates to a variant of a salmon ladder where a tubular member is connecting two separate water basins at different levels. The tube has different diameter along the length thereof to obtain a varying velocity of flow in different parts of the tube. GB2299920 relates to a floating fish pass connecting two water basins at different levels, the fish pass being a channel having rectangular cross section, where the fish is allowed to swim upstream in the flowing water. [0008] FR2666960 and US20100086357 both relate to eel passes, comprising a slanting channel having a bottom portion covered with a bristle substrate to imitate grass. The bristle substrate is kept wet by irrigation with water for keeping the bristle substrate sufficiently wet to imitate the wet grass in which eels normally migrate between waters. According to FR2666960, a collecting sump for collecting eel falling over the upper edge of the slanting channel is arranged to collect the eels and to lead the eels into a tubular member to transport the eels together with water to a location where the eels are to be released. It is mentioned that eels may be taken out here for weighing, etc. [0009] An object for the present invention is to provide for a method and a device for taking up fish, such as trout, salmon, char, or any other fish naturally migrating against flowing water, and thereby using the instincts of the fish for transfer of the fish to another net cage or transport container, for treatment and/or control, or for slaughtering, and at the same time avoiding the problems of the prior methods and devices. [0010] Other object will be clear for the skilled person in reading the present description and claims. SUMMARY OF INVENTION [0011] According to a first aspect, the present invention relates to a A method for taking fish up from a body of water comprising the steps of: providing a duct having a lower open end below the water surface and an upper open end arranged at a floating working platform above sea level, introducing water into the duct from the upper open end to give a water stream from the upper open end of the duct to the lower open end of the duct, and allowing the fish to swim up in the duct against the water stream therein, wherein the incoming water is directed to flow into the duct, and that the fish is separated from the flowing by means of a grating inclining from the top end of the duct to a separation plate arranged above the water level in the duct. [0015] The instinct of many fish species tells the fish to swim upstream as they do in the nature. Fish swimming upwards will end up at the top of the duct and may be taken from there for control, treatment, sorting, slaughtering, etc. By using the instinct of the fish, the stressful situations as mentioned on the introduction of the description are avoided, both reducing the stress of the fish and situations that may cause physical damage to the fish. [0016] According to a first embodiment, the fish is led from the grating to the separation plate by its own swimming speed, and is led further from the separation plate into a processing duct. By taking advantage of the swimming speed of the fish and only leading the fish onto the separation plate and further into a processing duct, the device may be kept simple and easy to maintain, at the same time as devices that may stress or even damage the fish, may be avoided. [0017] The processing duct may be provided for processing the fish swimming up the present device. One possible process may be that the fish is sprayed with chemicals in aqueous solution in the processing duct. [0018] The fish may alternatively or additionally be sorted according to present parameters in the processing duct. The fish that is released from the processing duct after being sprayed with chemicals and/or sorted may be introduced into one or more cage net (s) and/or containers. [0019] According to one embodiment, the fish is led into a facility for slaughtering of the fish. [0020] According to one embodiment, the body of water is body of water inside of a sea farm enclosure, such as a cage net. [0021] According to a second aspect, the present invention provides a device for taking up fish from a body of water, the device comprising: a duct arranged connected to a working platform above sea level where the duct is arranged to be placed with a lower open end at the surface of the water, and an upper open end arranged at the working platform; a water source for introducing water into the duct at the upper open end of the duct to give an artificial waterfall through the duct, wherein a grating is arranged upwards inclining from the upper end of the duct to a separation plate arranged above the water level in the duct, for leading the swimming fish from the duct onto the separation plate. [0024] According to one embodiment, the water source is a pumping arrangement is arranged for pumping up water from a depth and introducing the water into the duct. [0025] According to one embodiment, the water pumping arrangement comprises a vertically arranged tube that at is upper end is connected to a water inlet for introduction of water into the duct, and is open in its lower end, and where an air tube is arranged for introduction of air into the lower open end of the tube. This type of pumping device is a simple, and reliable pumping device only needing a compressor or other source of compressed air at the working platform, and no submerged moving parts needing maintenance, making it a cost efficient solution. Water pumped up from a depth is normally colder than the surface water. The cold water combined with introduction of air into the water, give an oxygen rich water in the duct. Fish tends to be attracted by water being more oxygen rich than the water where they are swimming. Accordingly, the use of this kind of pumping device will increase the efficiency of the present device in getting up fish, especially from fish farming cage nets or the like, where fish density may be so high that keeping a sufficiently high oxygen concentration in the water may be a challenge. [0026] According to one embodiment, the device further comprises a processing duct for processing of the fish. [0027] According to one embodiment, the processing duct comprises spray nozzles for spaying of fish with aqueous solutions of chemicals. [0028] According to one embodiment, the processing duct comprises detectors for measuring weight, size, number etc. of the fish passing through the processing duct. [0029] According to another embodiment, the processing duct comprises equipment for injecting medicine and/or identification markers into the fish. BRIEF DESCRIPTION OF DRAWINGS [0030] FIG. 1 is a side view of a net cage and a device according to the present invention, [0031] FIG. 2 is a perspective view of a net cage and a device according to the present invention, [0032] FIG. 3 is a detail view of a separation part of the present invention, and [0033] FIG. 4 is a partly cut through side view of a treatment zone of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0034] FIG. 1 is a side view illustrating of a net cage 1 and a device according to the present invention. A ring shaped floater 2 connected to a bag-shaped net 3 forms the basic part of the net cage 1 . The skilled person will know that a net cage will normally comprise additional elements, which are irrelevant for the understanding of the present invention. [0035] A device according to the present invention is arranged on a float 4 . The illustrated float 4 is a catamaran comprising a deck structure 5 connecting two hulls 6 , 6 ′. The float 4 may also comprise propulsion means, indicated by two outboard motors 7 . The float 4 forms a basis and support for the present device. The skilled person will understand that the float 4 may be a small vessel as illustrated, or a larger vessel. It is also possible to arrange a device according to the present invention permanently or temporary on a structure connected to the ring shaped floater 2 . [0036] A tube 10 is arranged substantially vertically downwards from the deck structure 5 . The tube 10 is preferably made of a flexible material, such as tarpaulin material, or tarp, for easy uptake and putting out of the tube for transport of the device, as will be further described below. Preferably, rings or a helix of metal or any other suitable material are/is preferably attached to the flexible tube material to prevent that the tube collapses in use. At its lower end, the tube is held in down by means of a weight body 11 . The illustrated weight body 11 is a ring shaped body, which also is arranged to keep the lower opening of the tube 10 open. Lifting wires 9 are in their lower ends connected to the weight body and are connected to the lower end of the tube 10 . The lifting wires 9 are arranged inside the tube 10 or are arranged in channels in the tube walls. The lifting wires are connected to a winch 8 at the floater for lifting and lowering of the tube 10 . [0037] An air tube 12 is also arranged from an air compressor at the deck structure 5 to a position below the lower opening of the tube 10 , ending in one or more nozzle(s) as air distributors arranged so that the air raises towards the water surface through the tube 10 . The illustrated air tube 12 is arranged inside the tube 10 and is lifted or lowered together with the tube 10 . [0038] A compressor 19 is arranged on the floater for production of compressed air for the air tube 12 . The air is released immediately below the lower opening of the tube 10 . The air streaming upwards inside of the tube 10 will cause water to flow upwards together with the air and will lift the resulting water column above the sea level to a level depending on the airflow. The upper opening of the tube 10 is connected to a water inlet 13 at the deck structure 5 for introduction of the water into a duct 14 , arranged from the water inlet 13 and ending below the water surface inside of the net cage as an artificial river. The duct 14 is preferably held in the required angle to the water surface by means of pontoons 15 connected to the duct and floating at the water surface. [0039] Fish like trout, salmon, and char, and relatives thereof living at least parts of their life in fresh water in the wild tend to swim against a current caused by flowing water, and more so if the incoming streaming water is more oxygen rich than the surrounding water basin. The water flowing down the duct is oxygen rich due to the use of the above-described “air pump” action. Additionally, as the water withdrawn from a depth, such as e.g. 10 to 100 meters, such as 20 to 50 meters, normally is colder than the water close to the water surface, even more oxygen may be dissolved in the water. The length of the tube 10 is adjusted to the preferred depth for taking in water at the place of use. [0040] The skilled person will understand that the present method and device is not dependent on the use of the above described “air pump” action, and that any other convenient pump may be used without leaving the scope of the invention. The air driven pump as described above where water is caused to flow upwards in the tube 10 by countercurrent flow with air blown into the tube, is the presently preferred pump as it is simple and adds oxygen to the water. If mechanical pumps are used, air or oxygen might be added to the water before introduction into the duct 14 . [0041] Provided that the fish in the cage net is of a species attracted to running, and oxygen rich water, the fish in the net cage will be attracted to the flowing water in the duct and will start swimming upwards the duct. It is assumed that an inclination of the duct of about 0.2% to about 5%, i.e. an inclination of 0.2 cm per meter, to 5 cm per meter from the sea level to the top of the duct. It is assumed that the most preferred inclination will be from about 0.4 to 3%, such as 0.5 to 2.5%, dependent on the fish species to be taken up. [0042] The water inlet 13 is connected to the duct 14 so that the water is directed into the duct. A separation plate 17 is arranged at a level above the level of the streaming water to avoid the upcoming water to flow in any other direction. A grating 16 is arranged to prevent the fish from swimming down into the tube 10 and to lead the fish up on the separation plate 17 . The grating is inclining upwards from the upper end of the duct, so that fishes swimming upwards the duct 14 are lifted up by means of their own speed and the tilted grating 16 onto the separation plate 17 . [0043] The fish entering the separation plate 17 has a speed sufficient to slide over the separation plate and into a processing duct 18 . The processing duct is preferably slightly obliquely arranged so that the incoming fish slides from the separation plate 17 downwards the processing duct 18 . The inclination of the processing duct may be from about 0.1 to 2%, such as from 0.2 to 1% from separation plate towards the sea level. Fish entering the processing duct will normally move through the processing duct by the speed at which they enter the processing duct and their own swimming movement so that only a small inclination as indicated is necessary for the fish to move through the processing duct. The length of the processing duct is adopted to allow for the required process step(s) to be performed in the processing duct. Dependent on the needs and specific setup, different processing steps may be performed as the fish passes through the processing duct. Additionally, or alternatively, the fish may be led from the processing duct into specific treatment sections to ascertain that the treatment is finalized. [0044] The skilled person will understand that a duct with grating at its bottom part may be arranged between the separation plate 17 and the processing duct 18 for further separation of water from the fish, if needed. [0045] The embodiment illustrated in the figures includes equipment for treatment of the fish by spraying the fish with relevant chemicals. The chemicals in question may e.g. be chemicals for treatment against salmon louse or other parasites or illnesses. [0046] For such treatment, an aqueous solution of the relevant chemical(s) is introduced through spraying nozzles 20 arranged on a nozzle tube 21 above the fish sliding through the processing duct. A collection sump 22 covered by a grid 23 to allow water and chemicals is arranged in the bottom of the lower end of the processing duct, to collect water and chemicals and reduce the release of chemicals into the surroundings. The fish slides at the top of the grid 23 and into a fish outlet tube 24 . [0047] A chemicals outlet tube 25 is connected to the sump for withdrawing the used aqueous solution of chemicals for the treatment. The used solution may be recirculated into the nozzle tubes 21 and nozzles 20 by means of a treatment liquid pump 26 . A not shown bleed tube is preferably arranged to withdraw a part of the solution collected in the sump for deposition. Additionally, a not illustrated chemicals addition tube connected to a chemicals tank is preferably provide to add chemicals to the circulating treatment liquid to substitute loss of chemicals, to adjust the concentration of chemicals in the circulating liquid due to dilution thereof by water following the fish, and to substitute loss of chemicals and any bled off of chemicals. [0048] The skilled person understands that parts or all of the duct 14 , separation plate 17 and/or the processing duct 16 is covered, to avoid that any of the fishes escapes over the edges of the duct or further parts of the device. A cover 28 is illustrated over a part of the duct 14 . [0049] The illustrated fish outlet tube is arranged to release the treated fish into the same cage net from which it was taken up. The skilled person will understand that the fish outlet tube 24 can be arranged to release the treated fish into a different cage net, to ascertain that all the fish in one cage net to be treated is treated, and that only the treated fish is released into the other cage net. [0050] The skilled person will also understand that the processing duct are applicable here. In addition to, or instead of, a chemical treatment, the fish may be measured, weighted, sorted into different cage nets or other tanks, etc. The skilled person will be able to identify the relevant equipment for such operations and to make addition to the embodiment described herein without departing from the invention as defined in the claims. If the processing duct comprises separation means based on parameters such as weight, length etc. of the fish, more than one fish outlet tubes may be provided for leading and releasing the sort fish into different cage nets, tanks, etc. [0051] The processing duct may also comprise equipment for removing parasites at the outside of the fish, such as salmon louse by spraying with water or an aqueous solution. One possibility is here to include sensor equipment for identifying parasites to use spraying equipment targeting the individual parasite for removing them from the fish without damaging the fish. The skilled person will also understand that separator plates for aligning the fish may be an advantage for such spraying to reduce the sideways movement of the fish, movement that may do the spraying less efficient or less targeted to the parasite. [0052] The present method may also be used for medical treatment, such as individual injections in the fish and/or for tagging of the fish by injecting an identifiable tag, such as a RFID. Methods for injections of smolt is known in the art. Such injections will presumable require using alignment devices so that the fish is introduced individually into injection section(s). As soon as the fishes are aligned and individually separated from each other, they may also be weighted, scanned, sorted etc. [0053] One other possible use for the present invention may be for taking up fish to be slaughtered. The above-described processing duct may then be substituted by equipment for slaughtering of the fish, or the fish outlet tube 24 may lead the fish directly into a plant for slaughtering of the fish, or into a tank for transport of the fish to be slaughtered. [0054] A collection net 29 shaped as a half funnel having its smallest opening towards the lower end or the duct 14 may be connected to the lower end of the duct 14 , and opening into the water inside the cage net. The collection net 29 will assist in leading the fish from the cage net into the funnel 14 . Collection net floaters 31 are arranged at the sides of the collection net to keep the sides of the collection net floating at the surface as illustrated in the figures. [0055] The duct 14 is preferably pivotally arranged on the float 4 , so that it may be placed onto the deck 5 for transport. The duct 14 may also be divided into separate sections that may be separated for transport, or may be telescopically adjustable for transport. The fish outlet tube is also preferably arranged so that it may be taken onboard the float for transport. The skilled person will also understand that the tube 10 is winded up and out of the water for transport. [0056] The skilled person will understand that the present device for taking up fish may be arranged on a separate vessel as illustrated and described above, or the device or parts thereof may be arranged at the cage net floater. [0057] Even though the invention has been described with reference to a fish farm and cage nets, the skilled person will understand that the present method and device may be used for other purposes, such as taking up fish for treatment, control, scientific purposes etc. in any relevant body or water. Accordingly, it is also assumed that the present device and method may be of use for taking up fish in the wild during migration of fish where fish density normally is high, or for catching fish that has escaped from a fish farm e.g. due to damage or breakdown of a cage net or the like.

A method for taking fish up from a body of water comprising the steps of providing a duct ( 14 ) having a lower open end below the water surface and an upper open end arranged at a floating working platform ( 5 ) above sea level; introducing water into the duct ( 14 ) from the upper open end to give a water stream from the upper open end of the duct to the lower open end of the duct; and allowing the fish to swim up in the duct against the water stream therein. The incoming water is directed to flow into the duct, and the fish is separated from the flowing by means of a grating ( 16 ) inclining upwards from the top end of the duct to a separation plate ( 17 ) arranged above the water level in the duct. A device for taking up fish, using the mentioned method is also described.

FIELD OF THE INVENTION [0001] The present invention relates, in most general terms, to polymer based nanoparticles for the dermal or systemic delivery of therapeutic compounds. BACKGROUND OF THE INVENTION [0002] Dermal therapy is still a challenge due to the inability to bypass the skin and deliver sufficient amounts of therapeutic compounds, either hydrophilic or lipophilic, to the deep skin layers. The penetration and permeation of poorly absorbed active ingredients can be improved by the addition of specific enhancers to the formulation, by the use of colloidal delivery systems, especially nanoparticles. The benefits of nanoparticles in such applications have been shown recently in several scientific fields, but little is known about the potential penetration of nanoparticles through the different skin layers. Nanoparticles may exert biological effects, simply by virtue of their dimension (100 nm or less). [0003] Encapsulation using nanoparticulate systems is an increasingly implemented strategy in drug targeting and delivery. Such systems have been proposed for topical administration to enhance percutaneous transport into and across the skin barrier. However, the mechanism by which such particulate formulations facilitate skin transport remains ambiguous. These nanometric systems present a large surface area, a property that renders them very promising delivery systems for dermal and transdermal delivery. Their small particle size ensures close contact with the stratum corneum and the ability to control the particle diameter may modulate the skin site deep layer localization [1]. [0004] In a recent study, confocal laser scanning microscopy (CLSM) was used to visualize the distribution of non-biodegradable, fluorescent, polystyrene nanoparticles (diameters 20 and 200 nm) across porcine skin. The surface images revealed that (i) polystyrene nanoparticles accumulated preferentially in the follicular openings, (ii) this distribution increased in a time-dependant manner, and (iii) the follicular localization was favored by the smaller particle size. Apart from follicular uptake, localization of nanoparticles in skin “furrows” was apparent from the surface images. However, cross-sectional images revealed that these non-follicular structures did not offer an alternative penetration pathway for the polymer vectors, which transport was clearly impeded by the stratum corneum [2]. [0005] Recently, lipid nanoparticles have shown a great potential as vehicles for topical administration of active substances, principally owing to the possible targeting effect and controlled release in different skin strata. Ketoprofen and naproxen loaded lipid nanoparticles were prepared, using hot high pressure homogenization and ultra sonication techniques, and characterized by means of photocorrelation spectroscopy and differential scanning calorimetry. Nanoparticle behavior on human skin was assessed, in vitro, to determine drug percutaneous absorption (Franz cell method) and in vivo to establish the active localization (tape-stripping technique) and the controlled release abilities (UVB-induced erythema model). Results demonstrated that the particles were able to reduce drug penetration, increasing, simultaneously, the permeation and the accumulation in the horny layer. A prolonged anti-inflammatory effect was observed in the case of drug loaded nanoparticles with respect to the drug solution. Direct as well as indirect evidences corroborate the early reports on the usefulness of lipid nanoparticles as carriers for topical administration, stimulating new and deeper investigations in the field [3]. [0006] Polymeric nanocapsules have also been proposed as carriers for active agents for topical application. Among the many advantages of such delivery systems is the ability of the polymeric shell to achieve sustained release of the active ingredient and increase the sensitive compounds, thus resulting in an improved therapeutic effect of dermatological formulations. Currently, several commercially available cosmetic products have incorporated nanoparticles for the encapsulation of vitamin A, rose extract and wheat germ oil [4]. [0007] Another very recent paper published by Wu et al. [5] shows that polystyrene and poly(methyl methacrylate) nanoparticles were not able to pass beyond the most superficial layers of the skin, i.e., Stratum Corneum, following a 6 hours topical application; even polystyrene nanoparticles as small as 30 nm were not able to penetrate beyond the Stratum Corneum. On the other hand, the hydrophobic compound encapsulated inside the nanoparticles was released and was able to diffuse across the deeper layers of the skin. [0008] The fact that nanoparticles are retarded at the skin surface may be an advantage, since the active ingredient can be slowly released over a prolonged period and diffuse across the skin barrier, while the nanoparticles themselves will not be systemically translocated. Thus, the authors [5] suggest that the penetration of nanoparticles across intact skin seems unlikely to induce a systemic effect. [0009] Nevertheless, health authorities are very attentive to the potential negative effects that may be induced by non biodegradable nanoparticles within and across the skin following topical application. In fact, starting November 2009, member states of the EU have adopted a single regulation for cosmetic products: this was in fact the first national legislation to incorporate rules relating to the use of nanomaterials in any cosmetic products [6]. According to this regulation, anyone who wishes to distribute a new nanomaterials containing product will be required to hand out safety information to the European Commission prior to entry to the market. It should be stressed that these concerns are related to the use of non biodegradable nanoparticles, whereas, the use of nanoparticles that will be degraded in the skin over a reasonable period of time is not expected to elicit any adverse effect especially if the degradation products are safe. [0010] In the 1970s, biodegradable polymers were suggested as appropriate drug delivery materials circumventing the requirement of polymer removal [7]. Aliphatic polyesters such as poly(ε-caprolactone) (PCL), poly(3-hydroxybutyrate) (PHB), poly(glycolic acid) (PGA), poly(lactic acid) (PLA) and its copolymers with glycolic acid i.e., poly(D,L-lactide-coglycolide) (PLGA) [8-11] have been widely used to formulate the controlled release devices. The reason why PLA and PLGA are widely used in the preparation of micro and nanoparticles, lies in the fact that they are non-toxic, well tolerated by the human body, biodegradable and biocompatible [12-13]. PLA and PGLA are FDA approved polymers for subcutaneous and intramuscular injections. [0011] The degradation process of PLGA, also known as bulk erosion, occurs by autocatalytic cleavage of the ester bonds through spontaneous hydrolysis into oligomers and D,L-lactic and glycolic acid monomers [14]. Lactic acid enters the tricarboxylic acid cycle and is metabolized and eliminated as CO 2 and water. Glycolic acid is either excreted unchanged in the urine or enters the Krebs cycle and is also eliminated as CO 2 and water. [0012] Recently the suitability of biodegradable poly-lactic acid nanoparticles (PLA, MW 30,000), loaded with fluorescent dyes as carriers for transepidermal drug delivery, was investigated in human skin explants using fluorescence microscopy, confocal laser scanning microscopy and flow cytometry [15]. The results showed that PLA particles penetrated into 50% of the vellus hair follicles, reaching a maximal depth corresponding to the entry of the sebaceous gland in 12-15% of all observed follicles. The accumulation of particles in the follicular ducts was accompanied by the release of dye to the viable epidermis and its retention in the sebaceous glands for up to 24 h. Kinetic studies in vitro as well as in skin explants revealed destabilization of the particles and significant release of incorporated dye occurred upon contact with organic solvents and the skin surface. According to the authors these results suggest that particles based on PLA polymers may be ideal carriers for hair follicle and sebaceous gland targeting. REFERENCES [0000] [1] Alves M P, Scarrone A L, Santos M, Pohlmann A R and Guterres S S (2007) Human skin penetration and distribution of nimesulide from hydrophilic gels containing nanocarriers. International journal of pharmaceutics 341(1-2):215-220. [2] Alvarez-Roman R, Naik A, Kalia Y N, Guy R H and Fessi H (2004) Skin penetration and distribution of polymeric nanoparticles. J Control Release 99(1):53-62. [3] Puglia C, Blasi P, Rizza L, Schoubben A, Bonina F, Rossi C and Ricci M (2008) Lipid nanoparticles for prolonged topical delivery: an in vitro and in vivo investigation. International journal of pharmaceutics 357(1-2):295-304. [4] Wu X, Price G J and Guy R H (2009b) Disposition of nanoparticles and an associated lipophilic permeant following topical application to the skin. Molecular pharmaceutics 6(5): 1441-1448. [5] Wu X, Griffin P, Price G J and Guy R H (2009a) Preparation and in vitro evaluation of topical formulations based on polystyrene-poly-2-hydroxyl methacrylate nanoparticles. Molecular pharmaceutics 6(5):1449-1456. [6] Bowman D M, van Calster G and Friedrichs S (2010) Nanomaterials and regulation of cosmetics. Nature nanotechnology 5(2):92. [7] Jalil R and Nixon J R (1990) Biodegradable poly(lactic acid) and poly(lactide-co-glycolide) microcapsules: problems associated with preparative techniques and release properties. Journal of microencapsulation 7(3):297-325. [8] Vert M, Schwach G, Engel R and Coudane J (1998) Something new in the field of PLA/GA bioresorbable polymers? J Control Release 53(1-3):85-92. [9] Jain R A (2000) The manufacturing techniques of various drug loaded biodegradable poly(lactide-co-glycolide) (PLGA) devices. Biomaterials 21(23):2475-2490. [10] Uhrich K E, Cannizzaro S M, Langer R S and Shakesheff K M (1999) Polymeric Systems for Controlled Drug Release. Chemical Reviews 99(11): 3181-3198. [11] Park T G (1995) Degradation of poly(lactic-co-glycolic acid) microspheres: effect of copolymer composition. Biomaterials 16(15):1123-1130. [12] Pistner H, Bendix D R, Muhling J and Reuther J F (1993) Poly(L-lactide): a long-term degradation study in vivo. Part III. Analytical characterization. Biomaterials 14(4):291-298. [13] Mordenti J, Thomsen K, Licko V, Berleau L, Kahn J W, Cuthbertson R A, Duenas E T, Ryan A M, Schofield C, Berger T W, Meng Y G and Cleland J (1999) Intraocular pharmacokinetics and safety of a humanized monoclonal antibody in rabbits after intravitreal administration of a solution or a PLGA microsphere formulation. Toxicol Sci 52(1):101-106. [14] Li S (1999) Hydrolytic degradation characteristics of aliphatic polyesters derived from lactic and glycolic acids. Journal of biomedical materials research 48(3):342-353. [15] Rancan F, Papakostas D, Hadam S, Hackbarth S, Delair T, Primard C, Verrier B, Sterry W, Blume-Peytavi U, Vogt A (2009) Investigation of polylactic acid (PLA) nanoparticles as drug delivery systems for local dermatotherapy. Pharm Res 26(8):2027-36. [16] Mitragotri S (2004) Breaking the skin barrier. Advanced drug delivery reviews 56(5):555-556. [17] Tan G, Xu P, Lawson L B, He J, Freytag L C, Clements J D and John V T (2010) Hydration effects on skin microstructure as probed by high-resolution cryo-scanning electron microscopy and mechanistic implications to enhanced transcutaneous delivery of biomacromolecules. Journal of pharmaceutical sciences 99(2):730-740. [18] Fessi H, Puisieux F, Devissaguet J P, Ammoury N and Benita S (1989) Nanocapsule formation by interfacial polymer deposition following solvent displacement. International Journal of Pharmaceutics 55 R1-R4. [19] PCT publication no. WO 2010/091187 [20] PCT publication no. WO 2004/084871 [21] US patent application no. US 2010/0247668 [22] PCT publication no. WO 2010/059253 SUMMARY OF THE INVENTION [0035] The present invention is based on a novel approach for the construction of therapeutic vehicles, which by themselves or in combination with various active therapeutic agents have the ability to penetrate the skin and induce a therapeutic effect. Where the vehicles are associated with active agents, they are capable of delivering sufficient amounts of the agents, either hydrophilic or lipophilic, to the deep skin layers, to thereby induce either a topical or a systemic effect. While the invention may be utilized primarily to deliver therapeutic agents via the skin or other tissue barriers, it may also be utilized to deliver therapeutic agents via numerous other routes of administration, e.g., oral, i.v., i.m, s.c ophthalmic, etc. as further disclosed herein. The vehicles of the invention are able to cross biological membranes, provide the ability to simultaneously deliver more than one agent to a desired site, in particular both hydrophobic and hydrophilic agents, and most importantly, are able to deliver macromolecules which administration is otherwise impeded or not possible. As may be appreciated, known nanoparticulate delivery systems such as liposomes and nano-emulsions are limited in their ability, mainly because such systems cannot incorporate significant concentrations of hydrophilic macromolecules and/or enhance their penetration and prolonged residence time in the upper layers of the skin. [0036] The nanoparticle vehicles of the invention possess a long physicochemical shelf-life over long storage periods, as freeze-dried powders, which can maintain their initial properties upon reconstitution with the addition of purified or sterile water prior to use. [0037] The invention disclosed herein is based on a nanoparticle which may be used per se (i.e. without additional active agents where the therapeutic effect is denoted by the particle itself), or may be modified to carry one or more therapeutic agents. The nanoparticle of the invention is able, naked or comprising additional therapeutic agents, to penetrate into a tissue barrier, e.g., skin, to at least the 10 superficial epidermis layers, to a depth of at least 4-20 μm (micrometers). The nanoparticles biodegrade in the skin layer into which they penetrate and can thus, in addition to the effect that may be exerted by the associated therapeutic agent, mainly a hydrating or moisturizing effect, provide xerosis cutis treatment (dry skin) to the penetrable tissue by lactic acid and glycolic acid or only the lactic acid for a period of at least 24 hours, 72 hours, and even for a period of weeks. [0038] Thus, in a first aspect of the invention there is provided a poly(lactic glycolic) acid (PLGA) nanoparticle having an average diameter of at most 500 nm, the PLGA having an average molecular weight of between 2,000 and 20,000 Da, wherein said nanoparticle being associated with at least one agent selected from a hydrophilic therapeutic agent conjugated to or associated with the surface of said nanoparticle, and a lipophilic therapeutic agent contained within said nanoparticle [0039] In some embodiments, the invention provides a poly(lactic glycolic) acid (PLGA) nanoparticle having an average diameter of at most 500 nm, the PLGA having an average molecular weight of between 2,000 and 20,000 Da, the nanoparticle being surface-associated to at least one hydrophilic therapeutic agent. [0040] In further embodiments, the invention provides a PLGA nanoparticle having an average diameter of at most 500 nm, the PLGA having an average molecular weight of between 2,000 and 20,000 Da, the nanoparticle containing therein at least one lipophilic therapeutic agent; namely, the nanoparticle may entrap or encapsulate the lipophilic therapeutic agent. [0041] As a person of skill in the art would understand, the therapeutic agent may be associated with the surface of the nanoparticle or may be contained within said nanoparticle as further explained below. In some embodiments, the therapeutic agent is not contained within the nanoparticles, namely the core or matrix of the nanoparticles is essentially free of such therapeutic agents. [0042] In some embodiments, the PLGA has an average molecular weight of between 2,000 and 10,000 Da. In other embodiments, the PLGA has an average molecular weight of between 2,000 and 7,000 Da. In other embodiments, the PLGA has an average molecular weight of between 2,000 and 5,000 Da. In still further embodiments, the PLGA has an average molecular weight of between 4,000 and 20,000 Da, or between 4,000 and 10,000 Da, or between 4,000 and 5,000 Da. In still other embodiments, the PLGA has an average molecular weight of about 2,000, about 4,500, about 5,000, about 7,000, or about 10,000 Da. [0043] As used herein, the “nanoparticle” of the invention is a particulate carrier, a nanocapsule (NC) or a nanosphere (NS), which is biocompatible and sufficiently resistant to chemical and/or physical destruction, such that a sufficient amount of the nanoparticles remain substantially intact after administration into the human or animal body and for sufficient time to be able to reach the desired target tissue (organ). Generally, the nanoparticles are spherical in shape, having an average diameter of up to 500 nm. Where the shape of the particle is not spherical, the diameter refers to the longest dimension of the particle. [0044] In some embodiments, the average diameter is between about 10 and 50 nm In further embodiments, the average diameter is at least about 50 nm. [0045] In some embodiments, the average diameter is between about 100 and 200 nm. In other embodiments, the average diameter is between about 200 and 300 nm. In further embodiments, the average diameter is between about 300 and 400 nm. In further embodiments, the average diameter is between about 400 and 500 nm. [0046] In other embodiments, the average diameter is between about 50 and 500 nm In other embodiments, the average diameter is between about 50 and 400 nm. In further embodiments, the average diameter is between about 50 and 300 nm. In further embodiments, the average diameter is between about 50 and 200 nm. In further embodiments, the average diameter is between about 50 and 100 nm. In further embodiments, the average diameter is between about 50 and 75 nm. In further embodiments, the average diameter is between about 50 and 60 nm. [0047] The nanoparticles may each be substantially of the same shape and/or size. In some embodiments, the nanoparticles have a distribution of diameters such that no more than 0.01 percent to 10 percent of the particles have a diameter greater than 10 percent above or below the average diameter noted above, and in some embodiments, such that no more than 0.1, 0.2, 0.4, 0.6, 0.8, 1, 2, 3, 4, 5, 6, 7, 8, or 9 percent of the nanoparticles have a diameter greater than 10 percent above or below the average diameters noted above. [0048] The PLGA polymer is a copolymer of polylactic acid (PLA) and polyglycolic acid (PGA), the copolymer being, in some embodiments, selected amongst block copolymer, random copolymer and grafted copolymer. In some embodiments, the copolymer is a random copolymer. [0049] In some embodiments, the nanoparticles are of PLGA listed as Generally Recognized as Safe (GRAS) under Sections 201(s) and 409 of the Federal Food, Drug, and Cosmetic Act, and are approved for use in microparticulate systems. [0050] In some embodiments, the average molecular weight of each of PLA and PGA, independently of the other, as present in the copolymer, is between 2,000 and 20,000 Da. In some embodiments, the PLA monomer is present in the PLGA in excess amounts. In other embodiments, the molar ratio of PLA to PGA is selected amongst 95:5, 90:10, 85:15, 80:20, 75:25, 70:30, 65:35, 60:40, 55:45 and 50:50. In some embodiments, the PLA to PGA molar ratio is 50:50 (1:1). [0051] In some embodiments, the nanoparticle is formed of a random copolymer of equimolar PLA and PGA, wherein the copolymer has a molecular weight of at least 4,500 Da, and is in the form of a nanoparticle having an average diameter between 100 and 200 nm. [0052] Nanoparticles of the invention or those utilized in accordance with the invention, which by themselves have a therapeutic effect (without an additional active agent) are used mainly for moisturizing/hydration purposes in cases of excess skin dryness that accompanies medical conditions, such as: atopic and contact dermatitis, psoriasis, eczema, thyroid disorders, ichtyosis, scleroderma, Sjorgen's disease and others. [0053] The nanoparticles according to the invention may be used as such to induce at least one effect, e.g., therapeutic effect, or may be associated with at least one agent, e.g., therapeutic agent, which is capable of inducing, enhancing, arresting or diminishing at least one effect, by way of treatment or prevention of unwanted conditions or diseases in a subject. The at least one agent (substance, molecule, element, compound, entity, or a combination thereof) may be selected amongst therapeutic agents, i.e., agents capable of inducing or modulating a therapeutic effect when administered in a therapeutically effective amount, and non-therapeutic agents, i.e., which by themselves do not induce or modulate a therapeutic effect but which endow the nanoparticles with a selected characteristic, as will be further disclosed hereinbelow. [0054] The at least one therapeutic agent may be selected amongst vitamins, proteins, anti-oxidants, peptides, polypeptides, lipids, carbohydrates, hormones, antibodies, monoclonal antibodies, vaccines and other prophylactic agents, diagnostic agents, contrasting agents, nucleic acids, nutraceutical agents, small molecules (of a molecular weight of less than about 1,000 Da or less than about 500 Da), electrolytes, drugs, immunological agents and any combination of any of the aforementioned. [0055] In some embodiments, the at least one agent is a macromolecule (molecular weight above 1000 Da), which delivery through the skin layers is otherwise not possible. Such macromolecules may be lipophilic. [0056] In some embodiments, the at least one therapeutic agent is selected from calcitonin, cyclosporin, insulin, dexamethasone, dexamethasone palmitate, cortisone, prednisone and others. [0057] For certain applications, the at least one therapeutic agent is selected in accordance with its molecular weight. Thus, the at least one therapeutic agent may be selected to have a molecular weight higher than 1,000 Da. In other embodiments, the agent is selected to have a molecular weight of no more than 300 Da. In further embodiments, the agent is selected to have a molecular weight of between 500 and 1,000 Da. [0058] In some embodiments, the nanoparticles of the invention may be further associated with a non-active agent. The non-active agent (non-therapeutic agnet) may be selected to modulate at least one characteristic of the nanoparticle, such characteristic may for example be one or more of size, polarity, hydrophobicity/hydrophilicity, electrical charge, reactivity, chemical stability, clearance rate, distribution, targeting and others. [0059] In some embodiments, the non-active agent is a substantially linear carbon chain having at least 5 carbon atoms, and may or may not have one or more heteroatoms in the linear carbon chain. [0060] In some embodiments, the non-active agent is selected from polyethylene glycols (PEG) of varying chain lengths, fatty acids, amino acids, aliphatic or non-aliphatic molecules, aliphatic thiols, aliphatic amines, and others. The agents may or may not be charged. [0061] In some embodiments, the non-active agent is a fatty amino acid (alkyl amino acid). In other embodiments, the alkyl portion of said alkyl amino acid has between 10 and 30 carbon atoms and may be linear or branched, saturated, semi saturated or unsaturated. In further embodiments, the amino acid portion of said alkyl amino acid may be selected amongst natural or non-natural amino acids, and/or amongst alpha- and/or beta-amino acids. [0062] In some embodiments, the nanoparticle may be non-PEGylated, i.e. the non-active agent is different from PEG. [0063] Thus, depending on various parameters (which may be therapeutic or non-therapeutic) associated with the at least one agent, e.g., therapeutic or non-active, (the parameters being, for example, solubility, molecular weight, polarity, hydrophobicity/hydrophilicity, electrical charge, reactivity, chemical stability, biological activity, and others), the agent may be contained (encapsulated) in said nanoparticle, embedded in the polymer matrix making up the nanoparticle and/or chemically or physically associated with the surface (whole surface or a portion thereof) of the nanoparticle. For the chosen application, the nanoparticle may therefore be in the form of core/shell (termed hereinafter also as nanocapsule), having a polymeric shell and a core which may be empty of an active material or contain at least one agent. [0064] Alternatively the nanoparticles are of a substantially uniform composition not featuring a distinct core/shell structure. These nanoparticles are herein referred to as nanospheres (NSs). In some embodiments, the inner part (core or inner matrix) of the nanoparticles are devoid of the at least one hydrophilic agent but can contain lipophilic agent dispersed or dissolved in the core or matrix, namely, the at least one hydrophilic agent may reside on or be associated with the surface of the nanoparticles. [0065] In other embodiments, the nanoparticles consist essentially of PLGA. [0066] Where nanocapsules (NCs) are employed, the at least one (active) lipophilic agent may be contained within the nanoparticles core (cavity), e.g., in an oily matrix, surrounded by a shell of the PLGA copolymer. [0067] In some embodiments, at least one therapeutic agent is associated with the surface of the nanoparticle and at least one different therapeutic agent is associated to be contained within a core of said nanoparticle or within a matrix of said nanoparticle. [0068] In some embodiments, the nanoparticles are nanocapsules containing at least one hydrophobic agent (the agent being contained in an oil core and thus is lipophilic). Depending on a particular intended application, the oily core may be selected amongst any oily organic solvent or medium (single material or mixture), such materials may be selected, in a non-limiting fashion, from octanoic acid, oleic acid, glyceryl tributyrate, long chain triglycerides (such as soybean) and others. [0069] Alternatively, relatively uniform structures, e.g., nanospheres may be employed, where the at least one agent may be embedded within the nanoparticles matrix, e.g., homogenously, resulting in a nanoparticle in which the concentration of the active agent within the nanoparticle is uniform. [0070] In some embodiments, modification of the nanoparticles (either nanocapusles or nanospheres) surface may be required to enhance the effectiveness of the nanoparticles in the delivery of a therapeutic agent. For example, the surface charge of the nanoparticles may be modified to achieve modified biodegradation and clearance of the nanoparticles. The porosity of the polymer element of the particle (whether the core in the nanocapsule or the uniform matrix in the nanosphere) may also be optimized to achieve extended and controlled release of the therapeutic agent. [0071] In another manifestation of the invention, the nanoparticles are modified to permit association therewith with at least one (therapeutic or non-therapeutic, or targeting) agent; the association may be a chemical association, such as covalent bonding, electrostatic bonding, ionic interaction, dipole-dipole interaction, hydrophilic interaction, van der Waal's interaction, hydrogen bonding, or a physical association of at least a portion of the agent with the nanoparticle. The physical association may be such that at least a portion of the at least one agent (or a linker moiety associated therewith) is entrapped, embedded, adsorbed or anchored into the nanoparticle element or surface. Herein, the physical association is referred to in general as “physical anchoring”. [0072] A nanoparticle may be associated with one or more of a variety of agents, either therapeutic or non-therapeutic. For example, when two or more agents are used, they can be similar or different. Utilization of a plurality of agents in a particular nanoparticle can allow the targeting of multiple biological targets or can increase the affinity for a particular target. In addition, the nanoparticle may contain two agents, each having a different solubility—one hydrophobic (e.g., in the core) and one hydrophilic (e.g., in the shell or extending out of the particle). [0073] The association between each of the nanoparticles and the various agents may be selected, based on the intended application, to be labile, namely undergo dissociation under specific conditions, or non-labile. Typically, where the at least one agent is a therapeutic agent, it is either associated with the surface of the nanoparticles via labile bond(s) or via one or more linker moieties. [0074] In some embodiments, the at least one agent is a therapeutic agent which association with the nanoparticles is via one or more linker moieties, the linker moiety being bifunctional, namely having a first (e.g., hydrophobic) portion which is capable of association (interaction) with the surface of the nanoparticles, and a second (e.g., hydrophilic) portion which is capable of association with the therapeutic agent. [0075] The nanoparticle associated with a plurality of such linker moieties is referred to herein as a “modified nanoparticle”, namely a nanoparticle, as defined, which at least a part of its surface is associated with linker moieties which are capable of undergoing association with at least one agent. The plurality of linkers interacting with the surface of the nanoparticles, need not all be associated with therapeutic agents. Some may be associated with other non-therapeutic agents; others may have bare end-groups (unassociated with any agent). In some embodiments, the linkers are associated with one or more different therapeutic agents. [0076] The association between the linker and the nanoparticle surface is typically selected from covalent bonding, electrostatic bonding, hydrogen bonding and physical anchoring (non-covalent) of at least a portion of the linker into the nanoparticle surface. The association between the linker and the at least one therapeutic agent is selected from covalent bonding, electrostatic bonding, and hydrogen bonding. [0077] In some embodiments, the linker moiety is associated with one or both of (a) the at least one therapeutic agent and (b) the nanoparticle surface via covalent bonding. In other embodiments, the association between the linker and the nanoparticle surface is via anchoring (e.g., in the surface of the nanoparticle and may penetrate into the solid/oil core of the nanoparticle) of at least a portion of the linker into the nanoparticle surface, with another portion of the linker exposed and extending away from the nanoparticle surface. [0078] In further embodiments, the linker is covalently bonded to said at least one therapeutic agent. In some embodiments, one or both of (a) the association of the linker with the therapeutic agent and (b) the association with the linker with the nanoparticle surface is labile. [0079] In some embodiments, in the nanoparticle having anchored (non-covalently) on its surface a plurality of linker moieties, each of said plurality of linker moieties is covalently bonded to at least one agent; both surface anchoring and covalent boding are labile. [0080] The association of the linker and any of the nanoparticles and the agent may be labile, namely the linker may be a readily cleavable linker, which is susceptible to dissociation under conditions found in vivo. For example, where the nanoparticles of the invention are employed as drug delivery systems for skin applications, topical or systemic, upon passing into and through one or more skin layers, the therapeutic may be released from the linker or the nanoparticles carrier. Readily cleavable associations can be such that are cleaved by an enzyme of a specific activity or by hydrolysis. For skin applications, the association between the linker and the therapeutic or between the nanoparticles and the linker may be selected to be cleavable by an enzyme present in one or more layers of skin tissue. [0081] In some embodiments, the linker moiety contains a carboxylic acid group (to form esters) or a thiol group (to form a sulfide bond). [0082] In other embodiments, the linker moiety is selected according to the half-life of the cleavable association, namely the quantity of the therapeutic that becomes dissociated from the linker. In some embodiments, the association of the linker to the therapeutic has a half-life of between 1 minute and 48 hours. In some embodiments, the half-life is less than 24 hours. [0083] In further embodiments, the linker moiety comprises a functional group selected from —S—, —NH—, —C(═O)O—, —C(═O)S—, —C(═O)NH—, —C(═S)NH—, —OC(═O)NH—, —NH(═O)NH—, —S(═O)NH—, —S(═O) 2 NH—, and others. [0084] In some embodiments, the linker is selected amongst polyethylene glycols (PEG) of varying chain lengths. PEG linkers may also be employed in combination with other linkers for the purpose of eluding the immune system and fending off attacking degradative enzymes. [0085] In some embodiments, the linker moiety is a fatty amino acid (alkyl amino acids), wherein the alkyl portion has between 10 and 30 carbon atoms and may be linear or branched, saturated, semi saturated or unsaturated. The amino acid portion may be selected amongst natural or non-natural amino acids, and/or amongst alpha- and/or beta-amino acids. The amino acid group of the linker may be derivable from an amino acid selected, without limitation, from alpha and beta amino acids. [0086] In some embodiments, the linker is a fatty cystein having an alkyl chain of at least 10 carbon atoms. [0087] In further embodiments, the linker is oleylcysteineamide of the formula I: [0000] [0088] In some embodiments, the linker moiety is a thiolated compound, and thus the modified nanoparticle is a thiolated nanoparticle capable of association with, e.g., macromolecules (molecular weight above 1000 Dalton), hydrophilic molecules and electrolytes. The association between the thiolated nanoparticle and the agent may be via an active group on the agent, such group may be a maleimide functional group. [0089] The present invention also provides a polymeric nanoparticle having on its surface a plurality of therapeutic agents, each agent being associated (bonded) to said nanoparticle via a linker moiety, the nanoparticles being of a polymeric material selected from poly(lactic acid) (PLA), poly(lacto-co-glycolide) (PLG), poly(lactic glycolic) acid (PLGA), poly(lactide), polyglycolic acid (PGA), poly(caprolactone), poly(hydroxybutyrate) and/or copolymers thereof. In some embodiments, said polymeric material is selected from PLA, PGA and PLGA. In further embodiments, the polymeric nanoparticles are of PLGA. [0090] In some embodiments, the linker moiety is oleylcysteineamide. In other embodiments, the nanoparticle has the physical characteristics disclosed hereinabove. In some embodiments, the nanoparticle is a poly(lactic glycolic) acid (PLGA) nanoparticle having an average diameter of at most 500 nm, the PLGA having an average molecular weight of up to 20,000 Da. [0091] The nanoparticles of the invention may be used in the preparation of pharmaceutical compositions for medical use. In some embodiments, the compositions are used in methods of therapeutic treatments, namely—treatment and/or prevention of skin disorders, diseases of the eye, and any other disease which may be treatable by the compositions of the invention. [0092] The concentration of nanoparticles in a pharmaceutical composition may be selected so that the amount is sufficient to deliver a desired effective amount of a therapeutic agent to the subject, and in accordance with the particular mode of administration selected. As known, the “effective amount” for purposes herein may be determined by such considerations as known in the art. The amount must be effective to achieve the desired therapeutic effect, depending, inter alia, on the type and severity of the disease to be treated and the treatment regime. The effective amount is typically determined in appropriately designed clinical trials (dose range studies) and the person versed in the art will know how to properly conduct such trials in order to determine the effective amount. As generally known, the effective amount depends on a variety of factors including the affinity of the ligand to the receptor, its distribution profile within the body, a variety of pharmacological parameters such as half life in the body, on undesired side effects, if any, on factors such as age and gender, and others. [0093] The pharmaceutical composition of the invention may comprise varying nanoparticle types or sizes, of different or same dispersion properties, utilizing different or same dispersing materials. [0094] The nanoparticles may also be used as drug or bioactive delivery systems to transport a wide range of therapeutic agents topically, orally, by inhalation, nasally, or parenterally into the circulatory system following administration. The nanoparticle delivery systems of the invention facilitate targeted drug delivery and controlled release applications, enhance drug bioavailability at the site of action also due to a decrease of clearance, reduce dosing frequency, and minimize side effects. [0095] In most general terms, the delivery system of the invention comprises: (i) a polymeric nanoparticle as disclosed herein; and (ii) at least one agent associated with said nanoparticle, said at least one agent being optionally associated with said surface via a linker moiety. [0098] In some embodiments, the linker has a first portion physically anchored (non-covalently associated) to said surface and a second portion associated with said at least one agent. In some embodiments, the first portion physically anchored to said surface is hydrophobic, and the second portion associated with said at least one agent is hydrophilic. [0099] The delivery system of the invention is capable of delivering the therapeutic agent at a rate allowing controlled release of the agent over at least about 12 hours, or in some embodiments, at least about 24 hours, or in other embodiments, over a period of 10-20 days. As such, the delivery system may be used for a variety of applications, such as, without limitation, drug delivery, gene therapy, medical diagnosis, and for medical therapeutics for, e.g., skin pathologies, cancer, pathogen-borne diseases, hormone-related diseases, reaction-by-products associated with organ transplants, and other abnormal cell or tissue growth. [0100] The delivery systems are typically administered as pharmaceutical compositions, comprising the system and a pharmaceutically acceptable carrier. The pharmaceutically acceptable carrier may be selected from vehicles, adjuvants, excipients, and diluents, which are readily available to the public. The pharmaceutically acceptable carrier is selected to be chemically inert to the delivery system of the invention or to any component thereof and one which has no detrimental side effects or toxicity under the conditions of use. [0101] The invention provides compositions formulated for a variety of applications. In some embodiments are provided compositions adapted for transdermal administration, e.g., for delivery of a therapeutic into the circulatory system of a subject. In further embodiments are provided compositions for topical administration. The topical composition is typically employed for delivering a therapeutic agent across the Stratum corneum. In further embodiments are provided compositions adapted for oral administration of a therapeutic agent. Further provided are compositions adapted for ophthalmic administration of a therapeutic agent. The ophthalmic compositions may be administered as eye drops or via injection into the eye. [0102] In some embodiments, an ophthalmic composition is provided which comprises at least one nanoparticle according to the invention, said nanoparticle being associated with a therapeutic macromolecule, the association being optionally via at least one linker. In some embodiments, the composition is in a form suitable for interoccular injection or in the form of eye drops. [0103] The choice of carrier will be determined in part by the particular therapeutic agent, as well as by the particular method used to administer the composition or the delivery system. Accordingly, the pharmaceutical composition or the delivery system of the present invention may be formulated for oral, enteral, buccal, nasal, topical, transepithelial, rectal, vaginal, aerosol, transmucosal, epidermal, transdermal, dermal, ophthalmic, pulmonary, subcutaneous, intradermal and/or parenteral administration routes. In some embodiments, the pharmaceutical composition or delivery system is administered transdermally, topically, subcutaneously and/or parenterally. [0104] The delivery system can be administered in a biocompatible aqueous or lipid solution. This solution can be comprised of, but not limited to, saline, water or a pharmaceutically acceptable organic medium. [0105] In some embodiments, the composition of the invention is essentially free of water. [0106] The administration of delivery system formulation can be carried out at a single dose or at a dose repeated once or several times after a certain time interval. The appropriate dosage may vary according to such parameters as the therapeutically effective dosage as dictated by and directly dependent on the individual being treated, the mode of administration, the unique characteristics of the therapeutic agent and the particular therapeutic effect to be achieved. Appropriate doses can be established by the person skilled in the art. [0107] The pharmaceutical composition of the present invention may be selected to treat, prevent or diagnose any pathology or condition. The term “treatment” or any lingual variation thereof, as used herein, refers to the administering of a therapeutic amount of the composition or system of the present invention which is effective to ameliorate undesired symptoms associated with a disease, to prevent the manifestation of such symptoms before they occur, to slow down the progression of the disease, slow down the deterioration of symptoms, to enhance the onset of remission period, slow down the irreversible damage caused in the progressive chronic stage of the disease, to delay the onset of said progressive stage, to lessen the severity or cure the disease, to improve survival rate or induce more rapid recovery, or to prevent the disease from occurring or a combination of two or more of the above [0108] Pharmaceutical compositions of the present invention may be particularly advantageous to those tissues protected by physical barriers. Such barriers may be the skin, a blood barrier (e.g., blood-thymus, blood-brain, blood-air, blood-testis, etc), organ external membrane and others. Where the barrier is the skin, the skin pathologies which may be treated by the pharmaceutical compositions of the invention include, but are not limited to antifungal disorders or diseases, acne, psoriasis, vitiligo, a keloid, a burn, a scar, xerosis, ichthoyosis, keratosis, keratoderma, dermatitis, pruritis, eczema, skin cancer, and a callus. [0109] The pharmaceutical compositions of the invention may be used to prevent or treat any dermatologic condition. In some embodiments, the dermatological condition is selected amongst dermatologic diseases, such as dermatitis, eczema, contact dermatitis, allergic contact dermatitis, irritant contact dermatitis, atopic dermatitis, infantile eczema, Besnier's prurigo, allergic dermatitis, flexural eczema, disseminated neurodermatitis, seborrheic (or seborrhoeic) dermatitis, infantile seborrheic dermatitis, adult seborreic dermatitis, psoriasis, neurodermatitis, scabies, systemic dermatitis, dermatitis herpetiformis, perioral dermatitis, discoid eczema, Nummular dermatitis, Housewives' eczema, Pompholyx dyshidrosis, Recalcitrant pustular eruptions of the palms and soles, Barber's or pustular psoriasis, Generalized Exfoliative Dermatitis, Stasis Dermatitis, varicose eczema, Dyshidrotic eczema, Lichen Simplex Chronicus (Localized Scratch Dermatitis; Neurodermatitis), Lichen Planus, Fungal infection, Candida intertrigo, tinea capitis, white spot, panau, ringworm, athlete's foot, moniliasis, candidiasis; dermatophyte infection, vesicular dermatitis, chronic dermatitis, spongiotic dermatitis, dermatitis venata, Vidal's lichen, asteatosis eczema dermatitis, autosensitization eczema, or a combination thereof. [0110] In further embodiments, the compositions of the invention may be used to prevent or treat pimples, acne vulgaris, birthmarks, freckles, tattoos, scars, burns, sun burns, wrinkles, frown lines, crow's feet, café-au-lait spots, benign skin tumors, which in one embodiment, is Seborrhoeic keratosis, Dermatosis papulosa nigra, Skin Tags, Sebaceous hyperplasia, Syringomas, Xanthelasma, or a combination thereof; benign skin growths, viral warts, diaper candidiasis, folliculitis, furuncles, boils, carbuncles, fungal infections of the skin, guttate hypomelanosis, hair loss, impetigo, melasma, molluscum contagiosum, rosacea, scapies, shingles, erysipelas, erythrasma, herpes zoster, varicella-zoster virus, chicken pox, skin cancers (such as squamos cell carcinoma, basal cell carcinoma, malignant melanoma), premalignant growths (such as congenital moles, actinic keratosis), urticaria, hives, vitiligo, Ichthyosis, Acanthosis Nigricans, Bullous Pemphigoid, Corns and Calluses, Dandruff, Dry Skin, Erythema Nodosum, Graves' Dermopathy, Henoch-Schönlein Purpura, Keratosis Pilaris, Lichen Nitidus, Lichen Planus, Lichen Sclerosus, Mastocytosis, Molluscum Contagiosum, Pityriasis Rosea, Pityriasis Rubra Pilaris, PLEVA, or Mucha-Habermann Disease, Epidermolysis Bullosa, Seborrheic Keratoses, Stevens-Johnson Syndrome, Pemphigus, or a combination thereof. [0111] In further embodiments, the compositions of the invention may be used to prevent or treat insect bites or stings. [0112] In additional embodiments, the compositions of the present invention may be used to prevent or treat dermatologic conditions that are associated with the eye area, such as Syringoma, Xanthelasma, Impetigo, atopic dermatitis, contact dermatitis, or a combination thereof; the scalp, fingernails, such as infection by bacteria, fungi, yeast and virus, Paronychia, or psoriasis; mouth area, such as Oral Lichen Planus, Cold Sores (Herpetic Gingivostomatitis), Oral Leukoplakia, Oral Candidiasis, or a combination thereof; or a combination thereof. [0113] As known, human skin is made of numerous layers which may be divided into three main group layers: Stratum corneum which is located on the outer surface of the skin, the epidermis and the dermis. While the Stratum corneum is a keratin-filled layer of cells in an extracellular lipid-rich matrix, which in fact is the main barrier to drug delivery into skin, the epidermis and the dermis layers are viable tissues. The epidermis is free from blood vessels, but the dermis contains capillary loops that can channel therapeutics for transepithelial systemic distribution. [0114] While transdermal delivery of drugs seems to be the route of choice, only a limited number of drugs can be administered through this route. The inability to transdermally deliver a greater variety of drugs depends mostly on the requirement for low molecular weight (drugs of molecular weights not higher than 500 Da), lipophilicity and small doses of the drug. The delivery system of the invention clearly overcomes these obstacles. As noted above, the system of the invention is able of holding therapeutic agents of a great variety of molecular weights and hydrophilicities. The delivery system of the invention permits the transport of the at least one therapeutic agent across at least one of the skin layers, across the Stratum corneum, the epidermis and the dermis layers. Without wishing to be bound by theory, the ability of the delivery system to transport the therapeutic across the Stratum corneum depends on a series of events that include diffusion of the intact system or the dissociated therapeutic agent and/or the dissociated nanoparticles through a hydrated keratin layer and into the deeper skin layers. [0115] Thus, the invention also provides a delivery system comprising: (i) a PLGA nanoparticle as defined herein; and (ii) at least one therapeutic agent associated with said nanoparticle, said at least one therapeutic agent being optionally associated with said surface via a linker moiety having, or is alternatively contained within said nanoparticle. [0118] Further provided is a multistage delivery system which comprises: (i) a polymeric nanoparticle as disclosed herein; (ii) a linker moiety associated with the surface of said polymeric nanoparticles; (iii) at least one therapeutic agent associated with said linker moiety; and (iv) optionally at least one additional agent which may be associated with the nanoparticle. [0123] With the ability of the delivery system of the invention to dissociate under biological conditions, the multistage system provides one or more of the following advantages: (1) the multistage system permits the transport of the therapeutic agent through a tissue barrier by various mechanisms; (2) the therapeutic agent may be dissociated from the linker or from the nanoparticle in cases where the agent is directly associated with the nanoparticle and thus deliverable to a particular target tissue or organ in the body of a subject administered with the delivery system; and (3) the modified nanoparticle, comprising the polymeric nanoparticle and the linker moiety (free of the therapeutic agent) may further travel through additional barrier tissues, increasing their hydration and inducing additional therapeutic effects; and (4) where the nanoparticles are nanocapsules also holding an agent within the capsule core, they may allow for simultaneous delivery and localization of a plurality of therapeutic agents. [0124] Accordingly, in the delivery system of the invention, each component may be designed to have a separate intended function, which may be different from an intended function of another component. For example, the therapeutic agent may be designed to target a specific site, which may be different from a site targeted by the linker moiety or the bare nanoparticle, and thus overcome or bypass a specific biological barrier, which may be different from the biological barrier being overcome or bypassed the system as a whole. For example, where the at least one agent is an antibody linked to the nanoparticle, it can bind to specific antigens on the surface of the cells in the epidermis or dermis while the agent within the core of the nanoparticle can be released earlier by simple diffusion. Furthermore, the incorporated agent can be mostly released from the nanoparticles while the nanoparticle can be fragmented or biodegraded more slowly and be eliminated through the dermis as monomers of PLA or PGA. [0125] The invention also provides a process for the preparation of a delivery system according to the invention, the process comprising: obtaining a nanoparticle, as defined herein; reacting said nanoparticle with a linker moiety under conditions permitting association between the nanoparticle surface and the linker moiety, to thereby obtain a surface-modified nanoparticle; and contacting the surface modified nanoparticle with at least one agent, e.g., therapeutic or non-therapeutic, to allow association between the linker end group; to thereby obtain a delivery system in accordance with the present invention. [0129] In some embodiments, the linker moiety may be associated with the therapeutic agent prior to the contacting with the nanoparticle and the process may thus comprise: obtaining a nanoparticle, as define herein; obtaining a therapeutic agent associated linker moiety; and reacting the therapeutic agent associated linker with said nanoparticle to permit association of at least a portion of said linker with the surface of the nanoparticle. [0133] In some embodiments, the delivery system/multistage system comprises nanoparticles associated with oleylcysteineamide, which is anchored at the interface of nanoparticles and thus may be easily applied to various PLA and PLGA polymer mixtures of different molecular weights, thereby resulting in a wide range of thiolated nanoparticles. [0134] The linking process does not require a priori chemical modification of the particle-forming polymer. This is achieved by the use of a molecular linker, e.g., oleylcysteineamide, having a lipophilic portion which non-covalently anchors to the particle's polymeric matrix or polymeric nanocapsule wall and a second portion comprising a thiol compound to which it is possible, in a subsequent step, to bind the desired therapeutic agent either directly or activated by a maleimide group. This approach eliminates the need to tailor for each different therapeutic agent a different nanoparticle composition, and enables a generic linker (with an active therapeutic), which can be used for different therapeutic applications. [0135] Other than employing the methods available for chemically associating the therapeutic agent to the linker, e.g., carbodimide mediated conjugation, the thiol modified nanoparticle surface may be used also or alternatively for the chelation and dermal delivery of vital electrolytes, e.g., divalent metals, such as copper, selenium, calcium, magnesium and zinc. The thiolated nanoparticles may also serve as a delivery system to chelate undesired excess amounts of metals and thus reduce the metal catalyzed ROS (Reactive Oxygen Species) mediated deleterious effect on the skin. [0136] The invention also provides a poly(lactic glycolic) acid (PLGA) nanoparticle, the PLGA having an average molecular weight of between 2,000 and 20,000 Da, said nanoparticle being surface-associated to at least one agent (therapeutic or non-therapeutic), and having an average diameter of at most 500 nm, the nanoparticles being obtainable by a process comprising: obtaining a PLGA nanoparticle having an average diameter of at most 500 nm, the PLGA having an average molecular weight of between 2,000 and 20,000 Da; reacting said nanoparticle with a linker moiety under conditions permitting association between the nanoparticle surface and the linker moiety, to thereby obtain a surface-modified nanoparticle; and contacting the surface-modified nanoparticle with at least one agent being selected from a therapeutic or non-active agent, to allow association between the linker end group with said at least one agent. [0140] Also provided is a process for the preparation of a poly(lactic glycolic) acid (PLGA) nanoparticle, the PLGA having an average molecular weight of between 2,000 and 20,000 Da, said nanoparticle being surface-associated to at least one agent, and having an average diameter of at most 500 nm, the process comprising: obtaining a PLGA nanoparticle having an average diameter of at most 500 nm, the PLGA having an average molecular weight of between 2,000 and 20,000 Da; reacting said nanoparticle with a linker moiety under conditions permitting association between the nanoparticle surface and the linker moiety, to thereby obtain a surface-modified nanoparticle; and contacting the surface-modified nanoparticle with at least one agent being selected from a therapeutic or non-active agent, to allow association between the linker end group with said at least one agent. [0144] In some embodiments, in the processes and products produced thereby, the linker moiety (e.g., oleylcysteineamide) is associated with the at least one agent prior to the association with the nanoparticle. The at least one agent is typically a therapeutic agent. [0145] Further provided is a process for the preparation of a poly(lactic glycolic) acid (PLGA) nanoparticle, the PLGA having an average molecular weight of between 2,000 and 20,000 Da, said nanoparticle being surface-associated to at least one agent, and having an average diameter of at most 500 nm, the process comprising: obtaining a PLGA nanoparticle having an average diameter of at most 500 nm, the PLGA having an average molecular weight of between 2,000 and 20,000 Da; reacting said nanoparticle with at least one agent being selected from a therapeutic or non-therapeutic agent, to allow association between the at least one agent and the surface of said nanoparticle. [0148] Also provided are polylactic acid (PLA) nanoparticles having an average diameter of at most 500 nm, the PLA having an average molecular weight of up to 10,000 Da. [0149] In some embodiments, the PLA has an average molecular weight of between 1,000 and 10,000 Da. In other embodiments, the PLA has an average molecular weight of between 1,000 and 5,000 Da. In further embodiments, the PLA has an average molecular weight of between 1,000 and 3,000 Da. In still other embodiments, the PLA has an average molecular weight of about 1,000, about 2,000, about 3,000, about 4,000 or about 5,000 Da. [0150] Further provided are uses of oleylcysteineamide in processes for preparing delivery systems for delivering therapeutic agents to a subject, said processes comprising reacting said oleylcysteineamide to a therapeutic agent to be delivered to said subject. [0151] Also provided is oleylcysteineamide for use in association with at least one nanoparticle. [0152] Further provided is a macromolecule chemically associated (e.g., via covalent bonding) to oleylcysteineamide. [0153] Also provided is a PLGA nanoparticle having on its surface a plurality of surface-exposed thiol groups, said thiol groups being activated for association with at least one agent selected from a therapeutic agent and a non-therapeutic agent, as disclosed herein. In some embodiments, said thiol groups are of oleylcysteineamide. BRIEF DESCRIPTION OF THE DRAWINGS [0154] In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [0155] FIGS. 1A-B are CRYO-TEM images of blank PLGA 4500 nanoparticles at various areas of the carbon grid ( FIG. 1A ) and blank PLGA 4500 nanoparticles at various areas of the carbon grid following one month storage at 4° C. ( FIG. 1B ). [0156] FIGS. 2A-B are CRYO-TEM images of DHEA loaded PLGA 4500 nanocapsules at various areas of the carbon grid ( FIG. 2A ) and DHEA loaded PLGA 50000 nanocapsules at various areas of the carbon grid ( FIG. 2B ). [0157] FIG. 3 is a collection of fluorescent images of various consecutive tape-stripping following topical administration over 3 h of different NIR-PLGA nanosphere formulations (2.25 mg/cm 2 ). Scanning was performed using ODYSSEY® Infra Red Imaging System. [0158] FIGS. 4A-D is a depiction of reconstructed fluorescent images of whole skin specimens, 2 h following topical administration of DiD incorporated nanocapsules or nanospheres (4.5 mg/cm 2 ). FIG. 4A-DiD loaded PLGA 4500 nanospheress; FIG. 4B-DiD loaded PLGA 50000 nanospheres; FIG. 4C-DiD control solution; FIG. 4D-DiD loaded PLGA 4500 nanocapsules. Z stack scanning was performed using a Zeiss LSM 710 confocal microscope. [0159] FIGS. 5A-E is a depiction of reconstructed fluorescent images of whole skin specimens, 2 h following topical administration of varied fluorescent nanocapsules or nanospheres (3.75 mg/cm 2 ). FIG. 5A-DiD incorporated and rhodamine B conjugated PLGA 4500 nanospheres; FIG. 5B-DiD incorporated and rhodamine B conjugated PLGA 4500 nanocapsules; FIG. 5C-Rhodamin B incorporated latex nanospheres; FIG. 5D-DiD and rhodamine B conjugated PLGA 4500 aqueous dispersion control; FIG. 5E-DiD and rhodamine B conjugated PLGA 4500 MCT containing aqueous dispersion control. Z stack scanning was performed using a Zeiss LSM 710 confocal microscope. [0160] FIGS. 6A-B exhibits DiD ( FIG. 6A ) and Rhodamine B ( FIG. 6B ) cumulative fluorescence intensity as a function of skin depth following 2 hours topical administration of various DiD incorporated RhdB-PLGA formulations (3.75 mg/cm 2 ) using 27 μm incremental optical sectioning. [0161] FIGS. 7A-D CLSM images of 8 μm thick vertical skin sections 2 h after topical administration of DID incorporated RhdB-PLGA NPs ( FIG. 7A ) and NCs ( FIG. 7B ) and their respective controls ( FIG. 7C and FIG. 7D ) (3.75 mg/cm 2 ). Bar=100 μm. [0162] FIG. 8 exhibits Rhodamine B cumulative fluorescence intensity as a function of skin depth following 2 hours topical administration of various rhodamine B incorporated formulations including PLGA nanospheres, nanocapsules and latex nanspheres (3.75 mg/cm 2 ) using 27 μm incremental optical sectioning. [0163] FIGS. 9A-D [ 3 H]DHEA ( FIG. 9A and FIG. 9C ) and [ 3 H]COE ( FIG. 9B and FIG. 9D ) distribution in the viable epidermis ( FIG. 9A and FIG. 9B ) and dermis ( FIG. 9C and FIG. 9D ) skin compartments over time following incubation of various radioactive nanocarriers and their respective controls. FIG. 9A and FIG. 9C : positively (♦) and negatively (▪) charged [ 3 H]DHEA NCs and their respective oil controls (⋄, □); FIG. 9B and FIG. 9D : [ 3 H]COE NSs (▴), [ 3 H]COE NCs () and their respective controls (Δ, ∘). Significant difference (P value <0.05) of the positively (*) and negatively (**) charged DHEA NCs in comparison to their respective controls [0164] FIG. 10 exhibits [ 3 H]DHEA amounts recorded in the receptor compartment fluids following topical application of positive (♦) and negative (▪) DHEA loaded NCs and their respective oily controls (⋄, □). Values are mean±SD. Significant difference (P value <0.05) of the positively (*) and negatively (**) charged DHEA NCs in comparison to their respective controls. [0165] FIGS. 11A-C are transmission electron microscopy microphotography of cetuximab immunonanoparticles (INPs) following incubation over 1 h, using goat anti-human IgG secondary antibody conjugated to 12 nm gold particle at different magnifications. [0166] FIGS. 12A-C are flow cytometry histograms demonstrating the binding of cetuximab immune nanoparticles to A549 cells. Depicted are surface activated nanoparticles ( FIG. 12A ) and rituximab (isotype matched) immunonanoparticles ( FIG. 12B ) at increasing concentrations (0.025 μg/ml, 0.05 μg/ml, 0.1 μg/ml, 0.5 μg/ml and 1 μg/ml) ( FIG. 12C ). 0.1 μg/ml, 0.5 μg/ml and 1 μg/ml equivalents of cetuximab INPs compared to 1 μg/ml equivalent of rituximab immune nanoparticles (full background histogram). [0167] FIGS. 13A-E are reconstructed fluorescent images of whole skin specimens, 3 h following topical administration of various immunological and reference nanoparticulate formulations (6 mg/cm 2 eq. to 0.12 mg MAb/cm 2 ), following specific immunohistochemistry staining Scanning was performed using an Olympus confocal microscope. [0168] FIG. 14 depicts individual fluorescence intensities per cm 2 calculated separately in up to twelve consecutive ˜35 μm sections, following topical administration of various immunological and reference nanoparticulate formulations (6 mg/cm 2 eq. to 0.12 mg MAb/cm 2 ), and specific immunohistochemistry staining. [0169] FIG. 15 depicts extrapolated cumulative fluorescent intensities per cm 2 calculated for up to 385 μm, following topical administration of various immunological and reference nanoparticulate formulations (6 mg/cm 2 eq. to 0.12 mg MAb/cm 2 ), and specific immunohistochemistry staining. [0170] FIG. 16 depicts calculated AUC values of cumulative fluorescent intensities per cm 2 calculated for up to 385 μm, following topical administration of various immunological and reference nanoparticulate formulations (6 mg/cm 2 eq. to 0.12 mg MAb/cm 2 ), and specific immunohistochemistry staining. DETAILED DESCRIPTION OF THE INVENTION I. Lactic Acid and Glycolic Delivery to The Skin [0171] Use is made of the clinically well-accepted PLGA polymers as well as PLA particles of a specific molecular weight, to prepare nanoparticles of a certain particle size that are applied onto the skin, penetrate in the upper layers of the dermis and release, in a controlled manner over time, lactic and glycolic acid, or only lactic acid, which are natural moisturizing factors, allowing a prolonged and sustained hydration of the skin without being harmful. [0172] The PLGA nanoparticles, per se, empty or loaded with appropriate actives are used as the prolonged active hydrating ingredients, as a result of their degradation within the skin leading to the progressive and continuous release of lactic and glycolic acid. Even if the nanoparticles penetrate into the deep layer of the epidermis or even the dermis, they do not induce any damage as previously described since the hydrolysis product lactic and glycolic acids are naturally eliminated or excreted. [0173] It should be emphasized the PLGA (or PLA), as the active hydrating components of the composition of the invention, are not merely used as carriers for delivery of other components to the skin, although the invention also encompasses the possibility that other beneficial active components are used. Thus, in accordance with the invention the composition is intended for topical application, i.e., contains carriers for topical applications, as well as for other applications. [0174] The nanoparticles of the invention are typically of a size smaller than 500 nm Typically, the nanoparticles are of a size range of between 100 and 200 nm, or between 50 and 100 nm. [0175] In some embodiments, the molecular weight of PLGA and the ratio between PLA and PGA is tailored so that the nanoparticles have the following properties: (a) Penetrate into the skin to at least the 10 superficial epidermis layers; (b) Penetrate to a depth of at least 4-20 micrometers into the skin; (c) Biodegrade in the skin layer into which they penetrate (typically about 15% in the Stratum corneum); (d) Sustained release of the lactic acid and glycolic acid or only the lactic acid for a period above 24 hours, preferably above 72 hours, more preferably about a week. [0180] Without wishing to be bound by theory, there seems to be interplay between the size of particle (which influences the penetration rate and the deepness of penetration), the ratio of PLA and PGA and the molecular weight of the PLGA, in such a way that the above properties can be achieved by a number of combinations. Several changes in parameters may neutralize each other. [0181] In some embodiments, the ratio of PLA:PGA is 85:15; 72:25; or 50:50. In some embodiments, the ratio is 50:50. [0182] In other embodiments, the molecular weight of the PLGA ranges from 2,000 to 10,000 Da. In some embodiments, the ratio is between 2,000 and 4,000. [0183] In other embodiments, the PLA particles may be employed per se, in such embodiments the PLA molecular weight is in the range of 4,000 and 20,000. II. Encapsulation Strategies of Insoluble Compounds in Nanoparticles—the Potential of DHEA Loaded PLGA Nanoparticles [0184] In the present invention, the nanoparticles may be loaded with active materials such as vitamins, peptides, and others as disclosed hereinabove. [0185] Humans have adrenals that secrete large amounts of dehydroepiandrosterone (DHEA) and its sulphate derivatives (DHEAS). A remarkable feature of plasma DHEA(S) levels in humans is their great decrease with aging. Researchers have postulated that this age-related decline in DHEA(S) levels may explain some of the degenerative changes associated with aging. Three mechanisms of action of DHEA(S) have been identified. DHEA and DHEA(S) are precursors of testosterone and estradiol. DHEA(S) is a neurosteroid, which modulates neuronal excitability via specific interactions with neurotransmitter receptors, and DHEA is an activator of calcium-gated potassium channels. [0186] Randomized, placebo-controlled clinical trials which included 280 healthy individuals (140 men and 140 women) aged 60-years and over treated with (near) physiological doses of DHEA (50 mg/day) over one year have yielded very positive results. Impact of DHEA replacement treatment was assessed on mood, well being, cognitive and sexual functions, bone mass, body composition, vascular risk factors, immune functions and skin. Interestingly, an improvement of the skin status was observed, particularly in women, in terms of hydration, epidermal thickness, sebum production, and skin pigmentation. Furthermore, no harmful consequences were observed following this 50 mg/day DHEA administration over one year. [0187] It is known that DHEA might be related to the process of skin aging through the regulation and degradation of extracellular matrix protein. It was demonstrated that DHEA can increase procollagen synthesis and inhibit collagen degradation by decreasing matrix metalloproteinase (MMP)-1 synthesis and increasing tissue inhibitor of matrix metalloprotease (TIMP-1) production in cultured dermal fibroblasts. DHEA (5%) in ethanol:olive oil (1:2) was topically applied to buttock skin of volunteers 12 times over 4 weeks, and was found to significantly increase the expression of procollagen alpha 1 (I) mRNA and protein in both aged and young skin. On the other hand, topical DHEA significantly decreased the basal expression of MMP-1 mRNA and protein, but increased the expression of TIMP-1 protein in aged skin. These recent results suggest the possibility of using DHEA as an anti-skin aging agent. [0188] Based on the overall reported results, exogenous DHEA, administered topically may promote keratinization of the epidermis, enhance skin hydration by increasing the endogenous production and secretion of sebum subsequently reinforcing the barrier effect of the skin, treat the atrophy of the dermis by inhibiting the loss of collagen and connective tissue and finally can modulate the pigmentation of the skin. These properties render DHEA the active of choice as an anti-aging active ingredient provided DHEA is adequately dissolved in the topical formulation, can diffuse from the formulation towards the skin and be fully bioavailable for skin penetration following dermal application. Indeed, DHEA exhibits complex solubility limitations in common cosmetic and pharmaceutical solvents such as water, polar oils and vegetable oils. DHEA is practically insoluble in water (0.02 mg/ml) and is known for its tendency to precipitate rapidly within topical regular formulations even at concentrations lower than 0.5%, yielding several polymorphic crystal forms which are difficult to control and exhibit very slow dissolution rate. Furthermore, DHEA shows low solubility in lipophilic phases with a maximum solubility of 1.77% in mid chain triglycerides. The most accepted topical dosage form is the o/w emulsion in which the DHEA should be dissolved in the lipophilic phase. However, this solution is very difficult to accomplish since very high concentrations of oil phase (more than 70%) are needed to achieve a DHEA concentration eliciting an adequate efficacy activity (approximately 0.5% w/v). Topical products with such high oil phase concentrations will be unpleasant and unappealing, ruling out their usefulness as cosmetic products. [0189] There is no doubt that the recrystallization process of DHEA should be prevented since it can potentially cause significant variations in therapeutic bioavailability and efficacy. The drug crystals need first to re-dissolve in the skin prior to diffusing and penetrating the superficial skin layers. Such a process is unlikely to occur easily and will significantly affect the activity of the product. Moreover, the recrystallization process can affect the stability and the physical appearance of the formulation. Thus, there is clearly a need to prepare pleasant and convenient o/w topical formulations where DHEA loaded nanoparticles can be dispersed at an adequate concentration precipitate out of the formulation. Furthermore, the DHEA embedded nanocarrier should be incorporated in a topical formulation, which can promote penetration of the active ingredient within the epidermis and dermis layers where its action is most needed. III. Delivery of Surface Bound Macromolecules and Minerals into the Skin Using Thiol Activated Nanoparticles [0190] Commercially available products utilizing transdermal delivery have been mainly limited to low molecular weight lipophilic drugs (MW<500 Da) [16], with larger molecular weights (MW>500 Da) facing penetration difficulties [17]. Due to the impervious nature of the Stratum corneum towards macromolecules, a suitable penetration enhancer should substantially improve transport of macromolecules through the skin Various technologies have been developed for this purpose, including the use of microneedles, electroporation, laser generated pressure waves, hyperthermia, low-frequency sonophoresis, iontophoresis, penetration enhancers, or a combination of these methods. Many penetration enhancement techniques face inherent challenges, such as scale-up and safety concerns [17]. The present invention proposes the delivery of macromolecules, mostly hydrophilic, by a non invasive method, using a surface binding technique of macromolecules to thiolated nanoparticles. Thiolated NPs—State of the Art [0191] Nanoparticles were functionalized with a maleimide moiety, which were then conjugated to a thiolated protein. Alternatively, nanoparticles can be functionalized with a thiol group then conjugated to a maleimidic residue on the protein. Traditionally, such delivery systems have been mostly used for the targeted delivery of drug loaded nanoparticles, principally to malignant tumors, where the surface conjugated protein is used simply as a targeting moiety recognizing disease specific epitopes. IV. Experimental 1. DiD Loaded PLGA NPs and NCs and/or Rhodamine B PLGA Conjugated NPs or NCS Preparation [0192] PLGA was dissolved in acetone containing 0.2% w/v Tween 80, at a concentration of 0.6% w/v. In case were NCs were prepared, octanoic acid or MCT at a concentration of 0.13% w/v was also added to the organic phase. If DiD loaded NPs were prepared then, an aliquot of acetone DiD solution at a concentration of 1 mg/ml was also added to the organic phase, resulting in a final concentration of 15-μg/ml. If rhodamine B PLGA conjugated NPs or NCs were prepared, 0.03% w/v rhodamine B tagged PLGA were dissolved in acetone together with 0.57% w/v non labeled PLGA. The organic phase was added to the aqueous phase containing 0.1% w/v Solutol® HS 15. The suspension was stirred at 900 rpm over 15 minutes and then concentrated by evaporation to a final polymer concentration of 30 mg/ml. The aqueous and oil control compositions were identical to the formulation described above, only without the polymer presence. 2. [ 3 H]DHEA and [ 3 H]COE PLGA Solid Nanoparticle Encapsulation and Evaluation DHEA NPs Preparation [0193] DHEA loaded PLGA nanocapsules were prepared using the interfacial deposition method [18]. DHEA was solubilized in octanoic acid/MCT/oleic acid and in acetone. If positively charged DHEA NCs were prepared, the cationic lipid, DOTAP [1,2-dioleoyl-3-trimethylammonium-propane], at a concentration of 0.1% w/v was added to the organic phase. In case were radioactive DHEA NCs were prepared, 15 μCi of tritiated DHEA were inserted into the oil core of the NCs during the preparation of the NCs together with 1 mg of cold DHEA. In case [ 3 H]Cholesteryl oleyl ether ([ 3 H]COE) were prepared, 80 and 127 μCi [ 3 H]COE were either dissolved in MCT to form NCs or simply added to the organic phase for NPs formation, respectively. The organic phase was added drop wise to the aqueous phase under stirring at 900 rpm, and the formulation was concentrated by evaporation to a polymer concentration of 8 mg/ml. The formulations were filtered through 0.8 μm membrane and then 3 ml from the different [ 3 H]DHEA NCs were dia-filtrated with 30 ml PBS (pH 7.4) (Vivaspin 300,000 MWCO, Vivascience, Stonehouse, UK) and filtered through 1.2 μm filter (w/0.8 μm Supor® Membrane, Pall corporation, Ann Arbor, USA). The radioactivity intensity for the overall formulations and their respective controls was set so a finite dose applied will be in the range of a total of 0.63-1.08 μCi/ml. The compositions of the organic phase and the aqueous phase are presented in Table 1. [0000] TABLE 1 compositions of organic phase and aqueous phase Organic phase Aqueous phase PLGA 4500 MW - 150 mg Solutol HS 15 - 50 mg Octanoic acid - 75 μl Water - 100 ml DHEA - 10 mg TWEEN 80 - 50 mg Acetone - 50 ml [0194] Particle size analysis: mean diameter and particle size distribution measurements were carried out utilizing an ALV Noninvasive Back Scattering High Performance Particle Sizer (ALV-NIBS HPPS, Langen, Germany) at 25° C. and using water as diluent. [0195] Zeta potential measurements: the zeta potential of the NPs was measured using the Malvern zetasizer (Malvern, UK) diluted in HPLC grade water. [0196] Scanning (SEM) and Transmission electron microscopy (TEM): morphological evaluation was performed by means of scanning and transmission TEM (Philips Technai F20 100 KV). Specimens for TEM visualization are prepared by mixing the sample with phosphotungstic acid 2% (w/v) pH 6.4 for negative staining. [0197] Cryo-Transmission Electron Microscopy (Cryo-TEM): [0198] A drop of the aqueous phase was placed on a carbon-coated holey polymer film supported on a 300 mesh Cu grid (Ted Pella Ltd), the excess liquid was blotted and the specimen was vitrified via a fast quench in liquid ethane to −170° C. The procedure was performed automatically in the Vitrobot (FEI). The vitrified specimens were transferred into liquid nitrogen for storage. The fast cooling is known to preserve the structures present at the bulk solution and therefore provides direct information on the morphology and aggregation state of the objects in the bulk solution without drying. The samples were studied using a FEI Tecnai 12 G2 TEM, at 120 kV with a Gatan cryo-holder maintained at −180° C., and images were recorded on a slow scan cooled charge-coupled device CCD Gatan manufactured camera. Images were recorded with the Digital Micrograph software package, at low dose conditions, to minimize electron beam radiation damage. 3. Diffusion Experiments [0199] Franz diffusion cells (Crown Glass, Sommerville, N.J., USA) with an effective diffusion area of 1/0.2 cm 2 and an acceptor compartment of 8 ml were used. The receptor fluid was a phosphate buffer, pH 7.4. [0200] Throughout the experiment, the receptor chamber content was continuously agitated by a small magnetic stirrer. The temperature of the skin was maintained at 32° C. by water circulating system regulated at 37° C. Finite doses of the vehicle and formulations (10-50 mg polymer per cell) were applied on the horny layer of the skin or cellulose membrane. The donor chamber was opened to the atmosphere. The exact time of application was noted and considered as time zero for each cell. At 4, 8, 12 and 24 h or 26 h, the complete receptor fluid was collected and replaced with fresh temperature equilibrated receptor medium. The determination of the diffused active ingredient concentration was determined from aliquots. At the end of the 24- or 26-h period, the skin surface was washed 5 times with 100 ml of distilled water or ethanol. The washing fluids were pooled and an aliquot part (1 ml) was assayed for the active ingredient concentration. [0201] The cells were then dismantled and the dermis separated from the epidermis by means of elevated temperature as described above. The active ingredient content was determined by means of HPLC or other validated analytical techniques. Furthermore, the presence of lactic or glycolic acid in the receptor medium was examined 4. DiD Loaded PLGA NPs and NCs and/or Rhodamine PLGA Conjugated NPs or NCS Site Localization [0202] Excised human skin or porcine ear skin samples were placed on Franz diffusion cells (PermeGear, Inc., Hellertown, Pa.), with an orifice diameter of 5/11.28 mm, ⅝ mL receptor volume and an effective diffusion area of 0.2/1.0 cm 2 . The receptor fluid was phosphate buffer, pH 7.4. Throughout the experiment, the receptor chamber content was continuously agitated by a small magnetic stirrer. The temperature of the skin was maintained at 32° C. by water circulating system regulated at 37° C. The solutions and different NP and NCs formulations either loaded with entrapped DiD fluorescent probe with free PLGA or PLGA covalently bound to rhodamine B were applied on the skin as detailed below. This protocol was adopted to follow the skin localization of both the entrapped DiD probe and of the conjugated rhodamine B polymer. The various formulations were prepared as described in the experimental section above. The dose applied for each formulation on the excised skin samples was 125 μl of a 30 mg/ml PLGA polymer concentration with an initial entrapped fluorescent content of DiD 30 μg/ml. [0203] After single incubation period or at different time intervals, some of the skin samples were dissected to identify the localization site of the nanocarrier in the various skin layers by confocal microscope. The procedure was as follows using histological sectioning. The skin specimens were fixated using formaldehyde 4% for 30 minutes. The fixated tissues were placed in an adequate plastic cubic embedding in tissue freezing medium (OCT, Tissue-Tek). Skin samples were then deeply frozen at −80° C. and vertically cut into 10 μm thick sections, utilizing Cryostat at −20° C. Then, the treated specimens were stored in a refrigerator untill to the confocal microscopic analysis. [0204] In addition, some whole mount skin specimens were kept intact after Franz cells incubation at selected time interval of 2 h and immediately observed by confocal microscope and further reconstructed using 3D imaging from z-stacks pictures. The fluorescence intensity versus skin depth for nanocarriers and respective controls using line profile (calculated intensity for each section and whole specimen accumulative intensity are reported). Samples data is provided in Table 2. [0000] TABLE 2 Description of the composition of each formulation topically applied with specific equivalent dose PLGA- DiD eq. PLGA, rhodamine B Oil core Volume dose Formulation mg/cm 2 conjugated % type in applied Applied Composition (MW, kDa) w/w from NPs NCs (μl) (μl) (μg) DiD NPs 4.5 (4) — — 150 1.125 DiD NPs 4.5 (50) — — 150 1.125 DiD NCs 4.5 (4) — Octanoic 150 1.125 acid (75) DiD micellar solution — — — 150 1.125 DiD incorporated 3.75 (4) 5 — 125 3.75 rhodamine B conjugated PLGA NPs DiD incorporated 3.75 (4) 5 MCT (113) 125 3.75 rhodamine B conjugated PLGA NCs Rhodamine B 3.75 (NA) — 125 — incorporated Latex NPs DiD and rhodamine — 5 — 125 3.75 B conjugated PLGA aqueous dispersion DiD and rhodamine — 5 MCT (113) 125 3.75 B conjugated PLGA oil containing aqueous dispersion 5. [ 3 H]DHEA NCs Site Localization and Deep Skin Layer Localization [0205] [ 3 H]DHEA NCs formulations were applied on the skin using the Franz cell diffusion system. [ 3 H]DHEA localization in the various skin layers was determined by skin compartment dissection technique. Dermatome pig skin (600-800 μm thick) was mounted on Franz diffusion cells (Crown Glass, Sommerville, N.J., USA) with an effective diffusion area of 1 cm 2 and an acceptor compartment of 8 ml (PBS, pH 7.4). At different time intervals, skin compartment dissection was carried out to identify the localization site of the nanocarriers in the skin surface, upper corneocytes layers, epidermis, dermis and receptor cell. First, the remainder of the formulation was collected following serial washings to allow adequate recovery. Then, the skin surface was removed by adequate sequential tapes stripping, contributing the first strip to the donor compartment. The rest of the viable epidermis was separated from the dermis by means of heat elevated temperature, and then chemically dissolved by solvable digestion liquid. Finally the receptor fluids were also collected and further analyzed. [0206] In addition, in an attempt to reveal quantitatively the biofate of the NCs and NPs in the various layers of the skin, 80 and 127 μCi [ 3 H]Cholesteryl oleyl ether ([ 3 H]COE) were either dissolved in the oil core of the NCs or entrapped in the nanomatrices of the NPs respectively. The radioactive tracer, [ 3 H]Cholesteryl oleyl ether ([ 3 H]COE) is highly lipophilic with a log P above 15 (>15) and its localization within skin layers reflects the localization of either the oil core of the NC or the nanomatrix of the NP since the probe cannot be released from the nanocarriers in view of its extremely high lipophilicity. 6. Oleylcysteineamide Synthesis and Characterization Oleylcysteineamide Synthesis [0207] Under a flow of nitrogen the flask was charged via syringe with oleic acid (OA) (2.0 g, 7.1 mmol), 60 ml of dry tetrahydrofuran, and triethylamine (0.5 ml, 7.1 mmol). Stirring was commenced, and the solution was cooled to an internal temperature of −15° C. using a dry ice-isopropyl alcohol bath at −5° to −10° C. Ethyl chloroformate (0.87 ml, 6.1 mmol) was added and the solution was stirred for 5 min. The addition of ethyl chloroformate resulted in an internal temperature rise to +8 to +10° C. and the precipitation of a white solid. Following the precipitation the continuously stirred mixture, still in the dry-isopropyl alcohol bath, was allowed to reach an internal temperature of −14° C. Cysteine (1.0 g, 8.26 mmol) dissolved in 5% Na 2 CO 3 solution (10 ml) introduced into the flask via a syringe needle, was vigorously bubbled through the solution for 10 min with manual stirring: the internal temperature rises abruptly to 25° C. With the flask still in the cooling bath, stirring was continued for an additional 30 min, and the reaction mixture was stored in the freezer at −15° C. overnight. The slurry was stirred with tetrahydrofuran (100 ml) at room temperature for 5 min and ammonium salts were removed by suction filtration through a Büchner funnel. After the solids were rinsed with tetrahydrofuran (20 ml), the filtrate was passed through a plug of silica gel (25 g Merck 60 230-400 mesh) in a coarse porosity sintered-glass filter funnel with aspirator suction. The funnel was further washed with acetonitrile (100 ml) and the combined filtrates were evaporated (rotary evaporator) to give a viscous liquid. [0208] Formation of oleylcysteineamide was confirmed by H-NMR (Mercury VX 300, Varian, Inc., CA, USA) and LC-MS (Finnigan LCQDuo, ThermoQuest, NY, USA). Oleylcysteineamide Characterization [0209] 1 H-NMR (CDCl 3 , δ): 0.818, 0.848, 0.868, 0.871, 0.889, 1.247, 1.255, 1.297, 1.391, 1.423, 1.452, 1.621, 1.642, 1.968, 1.989, 2.008, 2.174, 2.177, 2.268, 2.2932.320, 2.348, 3.005, 3.054, 4.881, 5.316, 5.325, 5.335, 5.343, 5.353, 5.369, 6.516, 6.540, 7.259 ppm. [0210] LC-MS: Peak at: 384.42. [0211] The NMR analysis confirms the formation of the linker oleylcysteineamide, while the LC-MS spectrum clearly corroborates the molecular weight of the product which is 385.6 g/mol 7. Preparation and Characterization of Surface Activated Nanoparticles and Macromolecules Conjugation [0212] Nanoparticles were prepared using the well established interfacial deposition method [18]. The oleylcysteineamide linker molecule was dissolved in the organic phase containing the polymer dissolved in water soluble organic solvent. The organic phase was then added drop wise to the aqueous phase which contains a surfactant. The suspension was evaporated at 37° C. under reduced pressure to a final nanoparticulate suspension volume of 10 ml. A maleimide bearing spacer molecule (LC-SMCC) was reacted with the desired macromolecule at pH 8 for subsequent conjugation to the thiol moiety. The thiol activated NPs and the relevant maleimide bearing molecule were then mixed and allowed to react overnight under a nitrogen atmosphere. The following day, free unbound molecules were separated from the conjugated NPs using a dia-filtration method. [0000] TABLE 3 Formulation composition Organic phase Aqueous phase Polymer Solutol HS 15 300 mg 100 mg Oleyl cysteine Water 20 mg 100 ml Tween 80 100 mg Acetone 50 ml Size and Zeta Potential Characterization: [0213] The size and zeta potential of the various NPs were measured in water using a DTS zetasizer (Malvern, UK). Determination of the Conjugation Efficiency of the Various Macromolecules to NPs: [0214] The conjugation efficiency of the macromolecules such as MAbs was determined using the calorimetric Bicinchoninic acid assay (BCA) for protein quantification (Pierce, Ill., USA). [0215] It should be noted, that the same procedure disclosed herein has been used to link hyaluronic acid to the nanoparticles. 8. Incorporation of Nanoparticles into Anhydrous Cream [0216] The advantages of dispersing the final product in anhydrous cream are enormous. Increasing amounts (0.1-10%) of freeze-dried powders of the NPs and the NPs prepared are incorporated into a novel cream comprising no water. The relative amounts of the ingredients of this cream are detailed in Table 4. [0000] TABLE 4 relative amounts of ingredients Ingredient Relative amont/100 Dow corning 9040 - 40.0-50.0 Cyclopentasiloxane (and) Dimethicone crosspolymer Dimethicone 5.0-7.0 Cyclopentasiloxane 10.0-15.0 Shin etsu KSG-16 20.0-35.0 Dimethicone (and) Dimethicone/Vinyl dimethicone Crosspolymer Boron Nitride  0.3-0.70 lauroyl Lysine Ajinomoto  0.2-0.70 hyaluronic acid MP 50000  0.1-0.40 Palmitoyloligopeptide - 0.05-0.3  Biopeptide CL Sederma Palmitoyl tetrapeptide - N- 0.05-0.3  Palmitoyl-Rigin IV. Preliminary Results Nanoparticle Formulation and Characterization [0217] Fluorescent nanoparticles were prepared to facilitate visual detection of the nanoparticles. PLA was conjugated to the fluorescent Rhodamine B probe. The nanoparticles were then prepared as described in the experimental section above. [0218] The results demonstrate a homogenous nanoparticle formulation. It was possible to see the nanoparticles owing to the fluorescence labeling with Rhodamine fluorophore at excitation/emission 560/580 nm. The nanoparticles exhibited a mean diameter of 52 nm and a Zeta potential value of −37.3 mV. [0219] This technique was used to detect and identify the localization of the nanoparticles with time in the various layers of the skin following topical application. Cryo-TEM Visualization of PLGA Biodegradable NPs One Month Following Preparation [0220] The Cryo-TEM images of blank PLGA 4500 nanoparticles at various areas of the carbon grid are depicted in FIG. 1A . Nanoparticles appear quite homogenous in size and shape. Furthermore, cryo-TEM images of blank PLGA 4500 nanoparticles at various areas of the carbon grid following one month storage at 4° C. are depicted in FIG. 1B . Nanoparticles are at different degradation stages. It can be noted that nanoparticles degraded with time in an aqueous environment. DHEA Loaded PLGA Nanoparticles [0221] DHEA was encapsulated within the oil core of PLGA (4500 or 50000 Da) nanocapules. The Cryo-TEM images at various areas of the carbon grid are depicted in FIGS. 2A and 2B . The nanocapsules appear spherical and nanometric and no DHEA crystals were observed. [0222] For encapsulation efficiency and active substance content determination, [ 3 H]DHEA was incorporated within MCT NCs. The initial theoretical DHEA content for the cationic and anionic NCs, following diafiltration with PBS (pH 7.4), were 0.49 and 0.52%, while the observed contents were 0.18 and 0.15% respectively. The encapsulation efficiency was therefore 36.5 and 30.4% for the positively and negatively charged NCs, respectively (as shown in Table 5). [0000] TABLE 5 DHEA content and loading efficiency within MCT NCs Theoretical Observed Yield Formulation conc. (%, w/v) conc. (%, w/v) (%) Positively charged [ 3 H]DHEA 0.013 0.006 36.53 loaded MCT NCs Negatively charged [ 3 H]DHEA 0.013 0.005 30.40 loaded MCT NCs Skin Penetration of Fluorescent Labeled Nanospheres [0223] To evaluate skin penetration of NPs, nanospheres comprising of PLGA 4500 or PLGA 50000 were prepared, while a quantity of the polymer was covalently labeled with the infra-red dye NIR-783. Fluorescent formulations were topically administered on abdominal human skin of 60 years old male, using Franz cells (2.25 mg/cm 2 ). After 3 h, skin specimens were washed and scanned using ODYSSEY® Infra Red Imaging System (LI-COR Biosciences, NE, USA). Fluorescent images of various consecutive tape stripping following topical administration are presented in FIG. 3 . Without being bound to theory, the results suggest that PLGA 4500 penetrate deeper than PLGA 50000 into the skin layers. This may be attributed to the more rapid biodegradation of PLGA 4500 compared to PLGA 50000 Skin Penetration of Fluorescent Labeled Nanocapsules [0224] To evaluate skin penetration of nanocapsules (NCs), as compared to nanospheres (NSs), formulations were incorporated with the fluorescent probe DiD. In order to define the bio-fate of PLGA nanocarrier, DiD fluorescent-probe-loaded-MCT NCs coated with PLGA covalently bound to rhodamine B were prepared. In the absence of MCT, NPs were formed. Non-degradable commercially available rhodamine B loaded Latex nanospheres were also investigated. [0225] The fluorescent formulations were topically administered on abdominal human skin of 40 years old female, using Franz cells (4.5 mg/cm 2 ). After 2 h, skin specimens were washed and scanned using Zeiss LSM710 confocal laser scanning microscope. Reconstructed fluorescent images of whole skin specimens are depicted in FIGS. 4A-D . The results clearly indicate that all DiD loaded nanoparticles elicited larger fluorescent values as compared to DiD control solution. In addition, PLGA 4500 nanocapsules exhibited superior skin penetration/retention as compared to other nanoparticulate delivery systems. [0226] The dually labeled nanocarriers formulations and their respective controls were applied for 2 hours on abdominal human skin of 50 years old female. Reconstructed fluorescent images of whole skin specimens are depicted in FIGS. 5A-E . The 3D of the NPs and NCs following 2 hours of topical treatment showed that more of the fluorescent cargo was released from NCs than NPs although both reached the same depth (close to 200 μm), while the respective controls remained on the superficial skin layers. The results clearly indicate that DiD loaded nanoparticles penetrates at the same fashion as was previously described. Furthermore, rhodamine B intensity, which originally derived from the fluorescent probe conjugation to PLGA, was much higher when the PLGA based nanoparticulate carriers were topically administered as compared to their respective treatments ( FIGS. 6A-B ), as was also depicted in the cross section images ( FIGS. 7A-D ). [0227] Finally, poor rhodamine B intensity was recorded following 2 hours incubation of non-degradable rhodamine B latex NSs on abdominal human skin of 30 years female. This result suggests that non-degradable based carrier has a major limit to release its cargo when compared to degradable systems ( FIG. 8 ). [ 3 H]DHEA NCs Site Localization and Deep Skin Layer Localization [0228] The results reported in FIGS. 9A-D show the ex-vivo dermato-biodistribution in the skin compartments of [ 3 H]DHEA following topical application of negatively and positively charged [ 3 H]DHEA loaded PLGA NCs and their respective controls at different incubation periods. Above 90% from the initial amount applied of the radiolabeled DHEA, from the different oil controls were recovered from the donor cell at each time interval up to 24 h. When DHEA loaded NCs were applied, again, most of the radioactive compound was collected at the donor compartment, with an average of over 90% up to 6 hours, with a notable decrease to approximately 80, 65 and 55% recorded at 8, 12 and 24 hours, respectively. [ 3 H]DHEA distribution in the upper skins layers as a function of SC depth following a sequential 10 tape stripping (TS) is depicted in Table 6. Each pair of TS was extracted and analyzed by liquid scintillation, resulting in a sequence of five sub-layers description of the SC from each specimen. Regardless to the treatment applied, it can be noted that the highest levels of [ 3 H]DHEA were detected in layers A and B, which represents the outermost layers of the SC, with a coordinate decrease recorded at the inner layers C, D and E. Time related accumulation of the radioactive compound in the different SC layers occurred when the negatively and positively charged [ 3 H]DHEA loaded NCs were applied. It should be noted that irrespective of the formulation, the concentration of radioactivity within the SC was low (around 1-2%). It can clearly be observed that at 24 h post application, the concentration of radioactivity diminished progressively in the internal layers (Table 6) of the SC. However, marked differences between the DHEA loaded NCs and their respective controls were recorded in the viable skin compartments (epidermis and dermis). [ 3 H]DHEA levels reached a plateau of ˜3% and 5.5% in the epidermis and dermis respectively, following 6 hours incubation of both positively and negatively charged DHEA NCs ( FIG. 9 ), while [ 3 H]DHEA levels obtained in the epidermis and dermis with the respective oil controls did not reach 1% over all the treatment periods up to 24 h ( FIG. 9 ) (P<0.05). [0000] TABLE 6 [ 3 H]DHEA distribution over time in the different SC layers of porcine skin following incubation with different nanocapsule formulations. Values are mean ± SD. N = 4 Incubation periods Stratum corneum layers (strips number) Formulation (hours) A (1-2) B (3-4) C (5-6) D (7-8) E (9-10) Positively 1 0.2% ± 0.0 0.2% ± 0.1 0.1% ± 0.0 0.1% ± 0.1 0.1% ± 0.1 charged 3 0.3% ± 0.2 0.2% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 [ 3 H]DHEA 6 0.3% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 loaded MCT NCs 8 0.7% ± 0.6 0.3% ± 0.2 0.2% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 12 2.0% ± 1.8 0.8% ± 0.7 0.3% ± 0.2 0.3% ± 0.2 0.2% ± 0.1 24 1.9% ± 0.9 0.8% ± 0.1 0.6% ± 0.2 0.4% ± 0.1 0.3% ± 0.1 Negatively 1 1.3% ± 0.1 0.4% ± 0.1 0.2% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 charged 3 0.3% ± 0.0 0.2% ± 0.0 0.1% ± 0.0 0.1% ± 0.0 0.1% ± 0.0 [ 3 H]DHEA 6 0.2% ± 0.1 0.2% ± 0.0 0.1% ± 0.0 0.1% ± 0.0 0.1% ± 0.0 loaded MCT NCs 8 0.8% ± 0.8 0.3% ± 0.3 0.3% ± 0.1 0.2% ± 0.1 0.2% ± 0.1 12 1.9% ± 1.3 0.8% ± 0.3 0.4% ± 0.1 0.3% ± 0.2 0.3% ± 0.2 24 2.9% ± 1.8 1.4% ± 0.5 0.7% ± 0.3 0.5% ± 0.3 0.4% ± 0.2 Positively 1 1.5% ± 0.9 1.1% ± 1.1 0.4% ± 0.5 0.2% ± 0.1 0.2% ± 0.1 charged oil 3 3.4% ± 1.4 1.4% ± 0.7 0.5% ± 0.3 0.2% ± 0.1 0.2% ± 0.1 control 6 2.4% ± 0.8 0.8% ± 0.3 0.3% ± 0.1 0.3% ± 0.1 0.2% ± 0.1 8 1.5% ± 0.5 0.7% ± 0.3 0.3% ± 0.1 0.2% ± 0.1 0.1% ± 0.1 12 4.6% ± 1.7 1.4% ± 0.6 0.5% ± 0.2 0.3% ± 0.1 0.2% ± 0.1 24 2.7% ± 0.8 0.9% ± 0.3 0.5% ± 0.2 0.3% ± 0.2 0.2% ± 0.2 Negatively 1 2.2% ± 2.4 0.8% ± 0.7 0.2% ± 0.2 0.1% ± 0.0 0.1% ± 0.1 charged oil 3 1.7% ± 0.7 0.5% ± 0.2 0.2% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 control 6 1.1% ± 0.3 0.3% ± 0.0 0.1% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 8 1.3% ± 0.1 0.4% ± 0.1 0.2% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 12 1.0% ± 0.5 0.2% ± 0.1 0.1% ± 0.0 0.1% ± 0.0 0.0% ± 0.0 24 2.0% ± 0.6 0.7% ± 0.2 0.3% ± 0.1 0.2% ± 0.1 0.1% ± 0.1 [0229] Increasing levels of the radioactive DHEA were found over time in the receptor compartment fluids when both positively and negatively DHEA loaded NCs were incubated, reaching 0.5%, 2.5% and 14% from the initial dose applied following 1 hour, 8 and 24 hours, respectively. On the other hand, the respective oil controls exhibited constant [ 3 H]DHEA levels lower than 1% radioactivity at most time intervals. Although lag time of 3 hours was observed for the different formulations, [ 3 H]DHEA appearance in the receptor fluids following positively and negatively NCs application was significantly higher than from the respective oil controls. The total amount of DHEA in the receptor fluids (μ g/cm 2 ), released from the different treatments, is plotted against the square root of time ( FIG. 10 ). The low slow flux value 0.063 (μg/cm 2 /h 0.5 ), calculated from the slopes of the plotted graphs, for the oil controls correlates with their reported limited release profile. Then again, significant higher [ 3 H]DHEA levels recorded in the receptor fluids when the negatively and positively DHEA NCs were topically applied, underlines a superior flux and superior percutaneous permeation of the drug when loaded into nanocarriers formulation. It should be emphasized that no significant difference between the two NCs formulation was observed at all time points indicating that the nature of the charge did not contribute to the enhanced skin penetration but rather the type of nanostructure used, i.e. vesicular nanocapsules. [0230] The highly lipophilic radioactive compound, [ 3 H]COE, was incorporated into PLGA NSs and MCT containing NCs, in an attempt to identify the fate of the empty nanocarrier when topically applied. Following diafiltration with PBS (pH=7.4) the encapsulation efficiency was 45% and 70% for the NSs and the NCs, respectively. Aqueous and oil controls of [ 3 H]COE, without polymer, were prepared for the ex-vivo experiments. Again, over 90% from the initial amount of the tritiated COE were collected from the donor compartment following each incubation period, irrespective of the formulation type (data not shown). Table 7 exhibits [ 3 H]COE dermatobiodistribution as a function of the SC layers following the different treatments, as was previously described for [ 3 H]DHEA. Up to 8 hours incubation of [ 3 H]COE loaded NSs and NCs, less than 1% from the applied dose were extracted from the upper skin layers. Interestingly, a notable increase in layers A and B of was observed following 12 hours incubation of the NSs and NCs, similar to the previous observation reported when DHEA NCs were applied. Although no notable differences, associate to the incubation periods, in the levels of [ 3 H]COE were recorded when the different controls were topically applied, the constant distribution of the [ 3 H]COE in MCT was higher in comparison to the [ 3 H]COE surfactant solution (Table 7). Finally, less than 0.5% of radioactivity was counted in the viable compartments (epidermis, dermis and receptor fluids) during the incubation periods, when both nanocarriers formulations and their respective control were applied ( FIG. 9 ). It appears that more incubation time is needed to differentiate between the various formulations of COE. [0000] TABLE 7 [ 3 H]COE distribution over time in the different SC layers of porcine skin following incubation with different nanocapsules formulations. Values are mean ± SD. N = 3 Incubation periods Stratum corneum layers (strips number) Formulation (hours) A (1-2) B (3-4) C (5-6) D (7-8) E (9-10) [ 3 H]Cholesteryl 1 0.7% ± 0.8 0.2% ± 0.2 0.1% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 oleyl ether 3 0.2% ± 0.1 0.2% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 0.1% ± 0.0 loaded PLGA NSs 6 0.3% ± 0.2 0.2% ± 0.2 0.1% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 8 0.9% ± 1.0 0.3% ± 0.4 0.1% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 12 0.9% ± 1.3 0.4% ± 0.5 0.4% ± 0.5 0.2% ± 0.2 0.1% ± 0.2 24 3.6% ± 0.7 1.5% ± 0.8 0.9% ± 0.5 0.7% ± 0.4 0.5% ± 0.4 [ 3 H]Cholesteryl 1 0.2% ± 0.2 0.1% ± 0.0 0.1% ± 0.0 0.0% ± 0.0 0.0% ± 0.0 oleyl ether 3 0.4% ± 0.5 0.1% ± 0.1 0.1% ± 0.0 0.0% ± 0.0 0.0% ± 0.0 loaded PLGA NCs 6 0.4% ± 0.6 0.1% ± 0.1 0.2% ± 0.3 0.1% ± 0.1 0.0% ± 0.0 8 0.6% ± 0.7 0.2% ± 0.2 0.1% ± 0.2 0.1% ± 0.1 0.1% ± 0.1 12 1.2% ± 0.8 0.4% ± 0.4 0.2% ± 0.1 0.2% ± 0.2 0.1% ± 0.1 24 2.4% ± 1.8 0.8% ± 0.6 0.4% ± 0.3 0.3% ± 0.2 0.2% ± 0.2 [ 3 H]Cholesteryl 1 0.4% ± 0.8 0.2% ± 0.3 0.2% ± 0.3 0.1% ± 0.2 0.3% ± 0.6 oleyl ether 3 0.1% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 0.0% ± 0.0 0.0% ± 0.0 surfactant 6 0.2% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 0.1% ± 0.0 0.1% ± 0.0 solution 8 0.5% ± 0.5 0.3% ± 0.3 0.3% ± 0.3 0.1% ± 0.2 0.1% ± 0.1 12 0.5% ± 0.4 0.3% ± 0.2 0.2% ± 0.2 0.1% ± 0.1 0.1% ± 0.1 24 0.5% ± 0.1 0.3% ± 0.2 0.2% ± 0.1 0.2% ± 0.1 0.1% ± 0.1 [ 3 H]Cholesteryl 1 1.8% ± 0.5 0.6% ± 0.4 0.3% ± 0.2 0.1% ± 0.1 0.1% ± 0.0 oleyl ether oil 3 1.0% ± 0.7 0.4% ± 0.3 0.1% ± 0.1 0.1% ± 0.0 0.0% ± 0.0 control 6 1.2% ± 0.3 0.4% ± 0.2 0.1% ± 0.0 0.1% ± 0.0 0.1% ± 0.0 8 1.7% ± 0.5 0.8% ± 0.5 0.3% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 12 1.2% ± 0.5 0.7% ± 0.2 0.2% ± 0.1 0.1% ± 0.1 0.1% ± 0.1 24 1.6% ± 0.3 0.5% ± 0.3 0.3% ± 0.1 0.1% ± 0.1 0.1% ± 0.0 Thiol Surface Activated NPs and MAbs Conjugated NPs [0231] Thiol surface activated NPs were prepared from the following polymers: PLGA of a MW of approximately 48,000 Da, PEG-PLGA 50,000 and PLGA 4500 , PEG-PLA 100,000 Preparation of ImmunoNPs Conjugated to Various MAbs [0235] The following MAbs were successfully conjugated to the surface of the thiolated NPs with high conjugation efficiency (see Table 8): Cetuximab Rituximab Herceptin Avastin [0000] TABLE 8 Properties of INPs conjugated to relevant MAbs Size Zeta potential Conjugation Polymer MAb (nm) (mV) (%) PEG-PLGA 50,000 / Cetuximab 75 −46 93 PLGA 48,000 PEG-PLGA 50,000 / Rituximab 73.75 N.A 86.7% PLGA 48,000 Morphological Evaluation Using TEM [0240] The coupling of cetuximab MAb to INPs was qualitatively confirmed by TEM observations, using 12 nm gold labeled goat anti-human IgG (Jackson ImmunoResearch Laboratories, PA, USA). Each gold black spot observed in FIGS. 11A-C represents MAb molecule attached to the INPs surfaces sites that reacted with the gold labeled IgG. It can be deduced that the MAb was conjugated to the surface of the INPs by the linker and the reaction conditions did not affect the affinity of the MAb to the secondary antibody. Binding Capacity Determination In Vitro in A549 Cell Line by Flow Cytometry [0241] For evaluation of the binding properties evaluation using flow cytometry, cells were detached using a 0.05% solution of EDTA. Cells were re-suspended in FACS medium (1% BSA, 0.02% Sodium Azide in PBS). 200,000 cells in 200 μl were used for each treatment. Cells were centrifuged at 1200 rpm at 4 degrees. Then, cells were incubated with either native cetuximab antibody or equivalent concentrations of cetuximab immunonanoparticles over ice, for 1 h. 0.005 μg/ml, 0.01 μg/ml, 0.025 μg/ml, 0.05 μg/ml, 0.1 μg/ml and 0.5 μg/ml cetuximab antibody or INPs equivalents were used. The anti-CD-20 antibody, rituximab (Mabthera®) was used as an isotype matched irrelevant nonbinding control. Cells were also incubated with equivalent concentrations of surface activated NPs and rituximab INPs as negative controls, to exclude non specific binding of INPs. Following 1 h incubation, cells were centrifuged and washed twice with FACS medium. Cells were then incubated for forty minutes at 4° C. in the dark with FITC-conjugated AffiniPure F(ab)′ 2 Fragment goat anti-human IgG (Jackson Immunoresearch). Cells were then centrifuged and washed twice with FACS medium. Cells were re-suspended in FACS medium and fluorescence was determined by flow cytometry. The results are depicted in FIGS. 12A-C . The results clearly indicate that cetuximab immunonanoparticles exhibited excellent binding properties, at all MAb concentrations evaluated. Non specific binding was eliminated by cell incubation of both surface activated NPs (thiol bearing NPs) and isotype matched rituximab immunonanoparticles. Skin Penetration of Immunonanoparticles [0242] To evaluate the ability of nanoparticles to enhance the penetration of macromolecules into the skin, INPs covalently conjugated to cetuximab MAb were prepared. 6 mg/cm 2 equivalent to 0.12 mg MAb/cm 2 were topically administered to 44 years old female abdominal human skin, over 3 h, against relevant controls. Then, skin specimens were washed and immunostained with Cy5 labeled goat anti-human secondary IgG (Jackson ImmunoResearch Laboratories, PA, USA). Reconstructed fluorescent images were performed using an Olympus confocal Microscope ( FIGS. 13A-E ). [0243] FIGS. 14 and 15 deal with the same experiment. It can be noted qualitatively and quantitatively) that the NPs and the INPs elicited the more intense fluorescent values with a more preannounced effect for the INPs as compared to NPs. FIG. 14 clearly demonstrates the most marked quantitative fluorescent intensity per cm 2 elicited by the INPs. From FIG. 15 and FIG. 16 it can be observed that INPs elicited the highest cumulative intensity per cm 2 , clearly indicating that the NPs promote MAb skin penetration/retention.

The present invention relates to a poly(lactic glycolic) acid (PLGA) nanoparticle associated with therapeutic agents for a variety of therapeutic applications.

PRIORITY [0001] The present application claims the benefit of U.S. Provisional Application Ser. No. 61/053,147, filed May 14, 2008, which is herein incorporated by reference in its entirety. THE FIELD OF THE INVENTION [0002] The present invention relates to precast composite floor systems. More specifically, the present invention relates to a precast composite floor which provides decreased weight, is able to bolt directly into a steel frame structure, and which allows for forming holes through the floor slab without concern for tensioning strands as well as the passage of mechanical equipment through the vertical stem wall of the floor section. BACKGROUND [0003] Precast concrete construction is often used for commercial and industrial buildings, as well as some larger residential buildings such as apartment complexes. Precast construction has several advantages, such as more rapid erection of a building, good quality control, and allowing a majority of the building structural members to be precast. Conventional precast structures, however, suffer from several disadvantages such as being heavy, requiring more material, and requiring more difficult connections between precast members and to the rest of the building structure. [0004] Currently, precast single tee and double tee panels are used for constructing floors. The precast single and double tees are typically eight feet wide and often between 25 and 40 feet long or longer. The single tee sections typically have a deck surface about 1.5 to 2 inches thick and a concrete beam extending down from the deck surface along the longitudinal center of the deck. The beam is usually about 8 inches thick and about 24 inches tall. [0005] Double tee panels usually have a deck surface which is about 2 inches thick and have two beams extending down from the deck. The beams are placed about four feet apart running down the length of the panel, and are about 6 inches thick and 24 inches tall. Often, the single and double tee panels are installed and about 2 or 3 inches of concrete topping is placed on top of the panels. [0006] Single and double tee panels have several drawbacks. These precast floor panels are heavy. Heavy floor panels require heavier columns and beams to support the floor panels and so on, increasing the weight of nearly every part of the building structure. Heavier structural elements use more materials and are thus more expensive, require increased lateral and vertical support, and may limit the height of the building for a particular soil load bearing capacity. [0007] Another drawback of the conventional precast floor systems is that mechanical equipment and ducts must be suspended beneath the beams, increasing the vertical space required for a floor. SUMMARY OF THE INVENTION [0008] The present invention is a precast composite floor system which is made up of composite floor panels and composite girders. The floor system is able to be fabricated in a factory, shipped to a job site, and erected in a manner that is quicker and more efficient than existing systems. The present invention provides precast panels which are lighter than existing panels. Reducing the amount of material in the floor of a building reduces the overall weight of the building, which in turn allows for smaller columns, foundations, and lateral systems. [0009] It is an object of the present invention to provide an improved precast composite concrete floor system. [0010] According to one aspect of the invention, a floor system is provided which reduces the weight of the floor panels. Floor panels of the present invention weight about half as much as conventional double tee floor panels. Reducing the weight of the floor panels reduces the load placed on the columns and other structural members of the building, allowing further reductions in weight. The reduction in building weight allows for the construction of taller structures and alleviates other construction limitations such as soil with poor load bearing capacity. [0011] According to another aspect of the present invention, a floor panel is provided with openings formed in the stem wall, allowing mechanical equipment to be run through the stem wall. Placing mechanical equipment through the stem walls reduces or eliminates the need for suspending ducts or other equipment below the floor panels, reducing the vertical space necessary for the floor. [0012] According to another aspect of the invention, a floor panel is provided which bolts into the steel structure of a building. Conventional precast floor panels are reinforced concrete members which have weld plates embedded therein. The floor panels are supported by concrete girders and columns, and the weld plates are welded to adjacent weld plates in other floor or wall members. Bolting the floor panels of the present invention to a steel structure allows for more rapid construction while requiring fewer trades to be present to install the floor panels. [0013] According to another aspect of the invention, there are no tensioning strands in the floor deck (slab), allowing most openings through the deck to be made at any time during the construction process, and allowing holes to be cut through virtually any location in the floor slab 2 except for directly over the beam section. [0014] These and other aspects of the present invention are realized in a precast composite floor system as shown and described in the following figures and related description. BRIEF DESCRIPTION OF THE DRAWINGS [0015] Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein: [0016] FIG. 1 is a perspective view of a finished composite panel; [0017] FIG. 2 is a perspective view of a finished composite girder; [0018] FIG. 3 is a cross-sectional view of a composite panel; [0019] FIG. 4 is a cross-sectional view of a panel beam with attached vertical L-shaped rebar; [0020] FIG. 5 is a side elevation view of a finished composite panel; [0021] FIG. 6 is a cross-sectional side elevation view of a composite panel; [0022] FIG. 7 is a partial cross-sectional side elevation view of a composite panel; [0023] FIG. 8 is a cross-sectional plan view of a composite panel at mid-slab level; [0024] FIG. 9 is a perspective view of a typical panel end embedded weld plate; [0025] FIG. 10 is a perspective view of a typical panel edge embedded weld plate; [0026] FIG. 11 is a cross-sectional view of a composite girder; [0027] FIG. 12 is a plan view of a finished composite girder; [0028] FIG. 13 is a side elevation view of a finished composite girder; [0029] FIG. 14 is a cross-sectional side elevation view of a composite girder; [0030] FIG. 15 is a perspective view of a typical girder embedded weld plate; [0031] FIG. 16 is a bottom view of three panels connected to a girder at each end; [0032] FIG. 17 is a cross-sectional view through a panel to panel connection at the slab edge weld plates; [0033] FIG. 18 is a bottom view of a panel to panel connection at the slab edge weld plates; [0034] FIG. 19 is a cross-sectional view of a panel to girder connection at the centerline of the longitudinal axis of the panel; [0035] FIG. 20 is a cross-sectional view of a panel to girder connection, with panels on both sides of the girder, at the centerline of the longitudinal axis of the panels; [0036] FIG. 21 is a cross-sectional perspective view of a composite panel; [0037] FIG. 22 is a cross sectional view of a composite panel in the casting form; and [0038] FIG. 23 is a cross sectional view of a composite girder in the casting form. [0039] It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single FIGURE, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity. Similarly, not every embodiment need accomplish all advantages of the present invention. DETAILED DESCRIPTION [0040] The invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The drawings and descriptions are exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims. [0041] The present system has several advantages over conventional concrete double tee systems. The biggest advantage is the reduced weight. A concrete double tee system with similar spans and loading conditions would weigh approximately 100% more per square foot than the present invention. Other structural members such as concrete girders and concrete columns that are used with double tee systems are also much heavier than columns used with the present invention. Increased weight of the double tee floor system necessitates larger footings and foundation walls. This is restrictive for taller structures and for construction in areas with poor soil bearing capacity. [0042] The vertical legs or walls of a double tee floor panel are solid and will not allow for passage of mechanical, plumbing or electrical through the Tee, thereby increasing the floor to floor dimension because all of the utilities need to be run below the floor structure. Openings in the stem wall of the present system allow the mechanical, electrical and plumbing to pass through the structure, thereby eliminating the need to run these elements below the floor structure. [0043] The present system also allows for greater flexibility in locating slab penetrations (openings through the floor slab) because the beams are spaced farther apart, typically 8 feet on center versus 4 or 5 feet for the legs of a double tee system. [0044] Double tee systems are assembled by weld plates embedded in each component and must bear on concrete or masonry structures. The current system is bolted into a lighter steel structure which makes it possible to use in mid to high-rise construction. [0045] Conventional steel and concrete composite construction also has several problems which are alleviated by the present invention. Conventional composite floor framing is very labor intensive on site. After installation of the columns for a conventionally framed floor, the rest of the materials for the conventional system are installed individually, and include the girders, joists, metal deck, nelson studs, reinforcing, edge enclosures, and poured concrete. This assembly takes much longer than the present invention due to the precast nature of the present system. With the present invention, tradesmen are able to occupy the floor to complete construction in a much shorter time frame which means shortened overall construction time. [0046] Because of the way the calculations are performed for a conventional composite floor, the concrete that is below the top of the flute in the decking is not used in the composite section, but still contributes to the weight of the concrete in the building and the cost for that material. By precasting the floor panels, the present system has eliminated the need for the metal deck. This eliminates the material and the labor required to weld the steel deck in place. [0047] In normal steel construction, the controlling factor over the size of the steel members is the necessity of the steel framing members to carry the full weight of the wet concrete without any of the concrete strength. In the present invention, the steel beams will be completely shored by the forms while the concrete is wet. This by itself reduces the size of the steel beam and eliminates the need for precambering the beam since the beams aren't required to support the weight of the wet concrete. [0048] Additionally, in normal steel construction the beams are aligned so that the tops of the girders and joists are flush. This is done because the metal deck is placed on the joists and girders and the deck is used as a form for the concrete slab. When calculating the section properties for this system, the distance from the top of steel beam to the middle of the concrete is one of the biggest factors. The present invention places a composite stem wall between the steel beam and the concrete deck, thereby increasing the distance from top of the steel beam to the centerline of the concrete slab. As such, the load-bearing strength and span capabilities of the precast panel system are greatly increased. The present flooring system eliminates a significant amount of steel and concrete material as compared to a conventional poured-in-place system. [0049] In describing the composite flooring system of the present invention, multiple views of the floor panel and girder are shown, including views of the parts thereof and cross-sectional views showing the internal construction thereof. Not every structure of the panel or girder is labeled or discussed with respect to every figure for clarity, but are understood to be part of the panel or girder. [0050] As shown in FIG. 1 , the composite floor panel 15 of the present invention is made up of steel panel beam 1 , a concrete slab or floor deck 2 , steel braces 3 , and a concrete stem wall 4 . The panel is Tee shaped, with the upper horizontal portion of the Tee being the concrete slab 2 . The concrete slab 2 is typically 3 inches thick and is supported by and connected to the concrete stem wall 4 . The stem wall 4 is connected to the steel beam, which is the lower portion of the tee, by welded studs and/or rebar. The concrete and steel together form a composite floor panel. [0051] When a beam supported at both ends is loaded the top half of the beam is under compression while the bottom half of the beam is under tension. Concrete has high compressive strength but low tensile strength, while steel has high tensile and compressive strength. In the present invention, the concrete slab at the top of the tee is under compression and the steel beam at the lower portion of the tee is under tension. The configuration of materials of the floor panel 15 utilizes the best structural properties of each material, making the panel more efficient. [0052] The stem wall 4 , for the majority of the span of the floor, can have large openings 4 a , or blockouts. Preferably, 50 percent of the thickness of the floor deck 2 is retained at the top of the stem wall 4 , leaving a small ridge as is visible in FIG. 1 . One advantage to putting in these holes is that it reduces the amount of concrete needed which in turn reduces the dead load of the panels. Because of the methods used for designing composite beams, this concrete adds very little strength to the section, and is only necessary to transfer shear loads between the slab and the steel beam. The amount of concrete necessary to do this can be retained between the blockouts 4 a . These holes are advantageous as they provide a convenient space to run HVAC ducts, piping and electrical conduit. [0053] Diagonal braces 3 which are welded to the panel beam 1 and embedded weld plates in the slab 2 provide additional support for the slab. In a typical configuration, the floor slab 2 is about 8 feet wide and between 25 and 40 feet long. The concrete floor deck 2 is typically about 3 inches thick. The stem wall 4 is typically between 12 and 36 inches tall. The openings 4 a in the stem wall 4 are typically located adjacent the stem wall, and may occupy the entire height of the stem wall if necessary. Thus, for an exemplary 24 inch stem wall 4 , the openings 4 a may be about 24 inches wide and 24 inches tall and have approximately 12 inch pillars of concrete between the openings. The steel beam 1 is typically about 12 inches tall and between 4 and 8 inches wide. [0054] As shown in FIG. 2 , a composite girder 16 for the present flooring system includes a concrete stem wall 12 and a steel wide flange beam 17 . The beam 17 has rebar 18 (or another similar reinforcement) welded to the top flange of the steel beam 17 . The rebar 18 extends into the stem wall 12 . Shear plates are welded onto the steel girder beam and are used for connecting the panel steel beam 1 to the girder steel beam 17 . The stem wall 12 includes openings 12 a which may be used to run HVAC ducts, pipes, and electrical conduit. A sufficient amount of continuous concrete 12 b (preferably between 50 and 33 percent of the height of the stem wall 12 ) is left above the openings 16 a so as to provide sufficient compression strength to make a strong composite girder from the stem wall 16 and beam 17 . [0055] The girder 16 is typically long enough to support several floor sections as shown in FIG. 16 , and as such the steel beam 17 may be about 24 feet long. The steel beam 17 is typically the same height as the steel beam 1 , and is thus typically 12 inches tall and between 4 and 8 inches wide. The stem wall 12 of the girder is typically between 12 and 36 inches tall, and typically matches the height of the stem wall 4 so that the floor deck 2 rests on top of the stem wall 12 when installed. The openings 12 a in the stem wall 12 are typically about half as tall as the stem wall, and thus may be about 12 inches tall and 24 inches wide for a 24 inch stem wall. [0056] Panel Construction [0057] The composite panel 15 is cast in steel forms 30 , as shown in FIG. 22 . The structure of the forms can vary in length and width as well as construction so long as the inside shape of the form is the correct profile for the finished tee-shaped panel 15 . The forms should be of sufficient strength to allow for numerous repetitive uses while maintaining the correct shape and configuration. [0058] The structure of the floor panel 15 is illustrated in FIGS. 3-10 , showing the completed panel and various parts thereof. The wide flange beam 1 for the panel 15 is cut to the appropriate length per shop drawings approved by the engineer of record. The holes 1 c used for connecting the panel beam 1 to the girder beam 17 are then drilled into each end of the panel beam 1 . The beam is then placed upright so that it is resting flush on its bottom flange 1 a . Nelson studs 7 or similar connectors are then welded to the top side of the top flange 1 b . Spacing of the nelson studs 7 is per approved shop drawings at intervals less than or equal to the maximum spacing allowed by prevailing building codes. Vertical L-shaped reinforcing bars 6 are then welded into place adjacent to the Nelson studs 7 which were previously welded to the top flange 1 b of the beam. The vertical reinforcing bars 6 project upward from the top flange of the beam and then turns 90 degrees so that the short leg 6 a of the L-shaped reinforcing bars 6 run horizontally and perpendicular to the longitudinal axis of the beam 1 . The vertical reinforcing bars 6 are spaced according to the shop drawings approved by the engineer of record, typically with one vertical reinforcing bar 6 per every Nelson Stud 7 . [0059] Lifting loops 10 made from reinforcing bar which have been bent into u-shapes are welded to the top flange 1 b of the beam at a point between the vertical reinforcing bars 6 where the concrete of the stem wall 4 will be poured to surround the lifting loops 10 and vertical reinforcing bars 6 , leaving the tops of the lifting loops uncovered by concrete for lifting the panel with a crane. The length of the lifting loops 10 is approximately 0.25″ less than the distance from the top side of the top flange 1 b of the beam 1 to the top surface of the finished concrete slab 2 . Lifting loops 10 are spaced at intervals determined by the overall length of the composite panel 15 . Typically three lifting loops 10 are used per panel 15 , with a minimum of two lifting loops on any single panel. [0060] The beam assembly, consisting of the wide flange beam 1 , lifting loops 10 and vertical L-shaped reinforcing bar 6 , is then moved to a floor-mounted jig to hold it steady while the horizontal slab reinforcing rebar 8 , 9 is tied to the horizontal leg 6 a of the L-shaped vertical reinforcing bars 6 . Reinforcing bars 9 running parallel to the longitudinal axis of the beam 1 are tied into place using standard tie wire to the underside of the horizontal leg 6 a of the L-shaped reinforcing bar 6 which was welded to the beam 1 . Horizontal reinforcing bars 8 running perpendicular to the longitudinal axis of the beam 1 are tied to the previously installed horizontal reinforcing bars 9 which are running parallel to the longitudinal axis of the beam 1 . Reinforcing bars 8 , 9 are cut to a length about two inches shorter than the overall length or width of the slab 2 in which they are to be cast. Horizontal reinforcing bars 8 , 9 are typically tied with 16 gauge tie wire at all intersections. [0061] Openings 4 a in the concrete stem wall 4 are created by attaching a formed shape to the beam 1 between the vertical reinforcing bars 6 . These openings 4 a are typically referred to as blockouts. Blockout forms are made using a variety of materials, including but not limited to, styrene foam, rubber, wood and steel. The most common method of blockout form construction is styrene foam blocks which are secured to the beam 1 by use of tape or glue. The blockout forms are coated in form release oil or silicone to prevent it from bonding to the stem wall concrete 4 that is poured around it. [0062] Weld plates 5 , 11 are placed into the form bed and secured by tie wire or small bolts to hold the weld plates into position until the concrete has cured sufficiently. These weld plates are also referred to as embedded weld plates or simply as embeds. There are several configurations of weld plates 5 , 11 used at different locations in the panel slab 2 . The slab edge embed 5 consists of a short length of angle iron 5 a , usually eight to twelve inches in length, with two straight reinforcing bars 5 b welded to the inside of the angle 5 a in a manner so that they extend out in the horizontal plane of the concrete slab 2 once they are placed in the forms. The weld plates 5 , 11 are spaced at equal intervals along both sides of the concrete slab 2 and are used to connect adjacent panels 15 to each other at the slab 2 level. [0063] Slab end weld plates 11 consist of short lengths of flat steel bar 11 a , usually eight to twelve inches in length, with two L-shaped reinforcing bars 11 b welded to one side of the flat bar and positioned so that the long leg of the L-shape will extend outward into the horizontal plane of the concrete slab 2 once they are placed in the forms. Slab end weld plates 11 are used to secure the panel slab 2 to the girder 16 below. [0064] The beam assembly, consisting of the steel wide flange beam 1 with attached vertical reinforcing 6 , the horizontal slab reinforcing 8 , 9 and the stem wall blockout forms, is lifted and set into the forms which have been sprayed with form release oil. The weld plates 5 , 11 have been tied or bolted to the forms and are then in contact with the horizontal reinforcing rebar 8 , 9 and all bars of the weld plates 5 , 11 are then tied with 16 gauge tie wire to intersecting reinforcing bars at each intersection. [0065] Rebar chairs may be placed under the horizontal reinforcing 9 to maintain the minimum distance between the bottom surface 2 a of the concrete slab 2 and the underside of the horizontal reinforcing 9 . Rebar chairs are spaced as needed, as determined by visual inspection once the beam assembly has been set in place and all weld plates 5 , 11 have been tied securely to the horizontal reinforcing 8 , 9 . [0066] Concrete is placed in the forms in a manner to ensure that all reinforcing bar 8 , 9 is sufficiently covered. The upper surface of the concrete slab 2 b is finished to industry standards for concrete floors. Typically the panels 15 are covered by plastic or concrete blankets and heated air is introduced under the forms to accelerate curing of the concrete. Once the concrete has cured sufficiently the panel 15 is lifted out of the forms by the lifting loops 10 attached to the beam 1 . The panel 15 is set on a flat, level surface and is held level by blocking, stands or other means acceptable to hold it level without putting excessive stresses on any one point in the panel 15 . [0067] Braces 3 are then welded to the underside of the slab at the slab edge weld plates 5 and run diagonally down to intersect with the vertical web id of the wide flange panel beam 1 . The brace 3 is welded to the beam 1 and the embed 5 so that in plan view the brace is perpendicular to the longitudinal axis of the panel beam 1 . One brace 3 is attached at each slab edge embed 5 . [0068] The blockout forms are removed from the beam assembly leaving voids in the concrete stem wall 4 . All bolts or tie wire which were used to secure the weld plates 5 , 11 in place before the concrete was formed and which are projecting from the concrete slab 2 are cut off flush with the bottom surface of the concrete slab 2 a. [0069] Girder Construction [0070] As shown in FIG. 23 , the composite girder 16 is cast in steel forms 31 . The structure of the forms can vary so long as the inside shape of the form is the correct profile for the finished composite girder 16 . The forms should be of sufficient strength to allow for numerous repetitive uses while maintaining the correct shape and configuration. [0071] FIGS. 11-15 show the various parts of the girder 16 . The wide flange beam 17 for the girder 16 is cut to the appropriate length per shop drawings approved by the engineer of record. The holes 17 c used for connecting the girder beam 17 to columns are then drilled into each end of the beam. The beam 17 is then stood upright so that it is resting flush on its bottom flange 17 a . Nelson studs 7 or similar connectors are then welded to the top side of the top flange 17 b . Spacing of the nelson studs 7 is per approved shop drawings at intervals less than or equal to the maximum spacing allowed by prevailing building codes. Vertical L-shaped reinforcing bars 18 are then welded into place adjacent to the Nelson studs 7 which were previously welded to the top flange 17 b of the beam. The vertical reinforcing bar 18 projects upward from the top flange 17 b of the beam and then turns ninety degrees to project horizontally and perpendicular to the longitudinal axis of the beam 17 . The vertical reinforcing bars 18 are spaced according to the shop drawings approved by the engineer of record, typically with one vertical reinforcing bar 18 per every Nelson Stud 7 . [0072] Lifting loops 10 , made from reinforcing bar which has been bent into a u-shape, are welded to the top flange 17 b of the beam. The length of the lifting loops 10 is approximately 0.25″ less than the distance from the top side of the top flange 17 b of the beam to the top surface of the girder stem wall. Lifting loops 10 are spaced at intervals determined by the overall length of the composite girder 16 . A minimum of two lifting loops 10 are used on any single girder 16 . [0073] The beam assembly, consisting of the wide flange beam 17 , lifting loops 10 and vertical L-shaped reinforcing bar 18 , is then moved to a floor-mounted jig to hold it steady while the horizontal reinforcing 19 is tied to the horizontal leg of the 1-shaped vertical reinforcing bars 18 which have been welded to the beam 17 . Reinforcing bars 19 running parallel to the longitudinal axis of the beam 17 are tied into place using 16 gauge tie wire to the top side of the horizontal leg 18 a of the L-shaped reinforcing bar 18 which was welded to the beam 17 . [0074] Blockouts or openings 12 a in the concrete of the girder 16 are created by attaching a formed shape to the beam 17 between the vertical reinforcing bars 18 which were welded to the beam 17 . The blockouts 12 a in a girder 16 are formed in the same manner as the blockouts in a panel stem wall 4 . [0075] The girder beam assembly is placed into the forms 31 on its side (although they could also be poured vertically. Rebar chairs 14 are used as necessary to keep the rebar 19 away from the form bed. Weld plates 25 (as shown in FIG. 15 ) are placed in the form at the desired intervals, and are typically secured to the forms as discussed above with respect to the floor panels 15 . Concrete is placed in the forms in a manner to ensure that all reinforcing bar 19 is sufficiently covered, typically leaving the tops of the lifting hoops 10 not covered in concrete. The side of the concrete girder 16 which is now in the horizontal position is finished to industry standards for concrete floors. The girders 16 are covered by plastic or concrete blankets and heated air is introduced under the forms to accelerate curing of the concrete. Once the concrete has cured sufficiently the girder 16 is lifted out of the forms by the lifting loops 10 attached to the beam 17 . [0076] Floor Assembly [0077] FIGS. 16 through 20 show a floor assembly and various details of the floor assembly. The girders 16 of the floor system are installed first. A girder 16 is lifted by a crane attached to the lifting loops 10 which were welded to the girder beam 17 and embedded in concrete. Girders 16 are attached to standard steel columns through bolted connections at the ends of the girders, using holes 17 c . Welded connections can be specified by the engineer of record if it is deemed necessary. [0078] Once the girders 16 are in position, the panels 15 can be installed. A panel 15 is lifted by a crane secured to the lifting loops 10 which were welded to the panel beam 1 and embedded into the concrete of the stem wall 4 . The panel 15 is set into place so that the vertical web 1 c of the panel beam 1 is in line with the appropriate shear tab 21 . The shear tabs are welded inside the girder beam 17 , connecting to the top flange, bottom flange, and web as shown. A separate bolt plate 20 is attached to both the girder shear tab 21 and the panel beam 1 with bolts. The bolted connection transfers all of the gravity forces acting on the panel 15 into the girder beam 17 . [0079] Floor panels 15 are connected to each other through the embedded weld plates 5 a at the slab edges. Lateral forces are transferred through these connections at the slab edge. As shown in FIG. 16 , a flat steel bar 22 of sufficient strength is welded to the underside of two adjacent weld plates 5 to bridge the weld plates. The minimum amount of weld is typically specified by the engineer of record on the project. As is seen in FIG. 17 , Panels 15 are typically placed with a small gap between the edges of the concrete slab 2 . Foam backer rod 23 is inserted into the gap and the remainder of the void is filled with non-shrink grout 24 . [0080] The underside of the panel slab 2 is attached to the top of the girder 16 by welding the embedded weld plate 11 in the bottom of the slab 2 to the embed weld plate 25 in the top of the girder 16 . Once all of the floor panels 15 are in place and all joints have been filled with grout 24 a lightweight topping of concrete 26 is often poured over the floor slabs 2 to provide the final wear surface and level out any variations in the slab elevations. [0081] There is thus disclosed an improved precast composite flooring system. It will be appreciated that numerous changes may be made to the present invention without departing from the scope of the claims.

A precast composite flooring system utilizes girders and floor panels having steel lower structures placed in tension and concrete upper structures places in compression. Openings through a stem wall allow ducts, pipes, and conduits to be run therethrough. The system provides reduced weight over conventional precast or pour in place systems, allowing further reduction in the weight and size of other building components. The floor deck does not use tensioning strands, allowing openings to be formed at nearly any stage of construction and with reduced concern over cutting steel reinforcement. The floor panels and girders bolt together and bolt to a steel column frame, allowing for more efficient assembly.

BACKGROUND OF THE INVENTION This invention relates to spring suspensions for vehicle seats. It is well known to provide a spring suspension for a vehicle seat, the suspension comprising a seat frame and a base frame interconnected by a scissor-action linkage arm system, the system including two pairs of scissor-action linkage arms spaced apart on a common pivot axis, said arms having pivotal interconnections at their opposite ends with said frames, to permit the frames to move towards and away from one another, each pivotal connection on one pair of arms being coaxial with a corresponding pivotal connection on the other pair of arms, and a biassing spring connected between parts of the suspension which pivot relatively to one another during relative movement of the frames towards or away from each other, to bias the two frames away from one another. A vehicle seat incorporating such a suspension is described in U.S. Pat. No. 3,109,621. Such a vehicle seat spring suspension is very effective in isolating the seat occupant from vibrations transmitted in a vertical direction from the base frame to the seat frame, but has little if any effect on vibrations transmitted between the base frame and seat frame in a direction longitudinally of the suspension (i.e. in the fore-and-aft direction). The seat occupant can be isolated from such longitudinal vibrations by mounting the seat suspension on a mechanism designed to isolate longitudinal vibrations, but such a mechanism increases the space necessary to accommodate the seat and adds considerably to cost. There is therefore a requirement, in a spring suspension of the type described, for simple and inexpensive means for damping vibrations transmitted between the base frame and seat frame in the longitudinal direction. SUMMARY OF THE INVENTION The above-mentioned requirement is met, in accordance with the invention, by all of the pivotal connections between one of said frames and the adjacent ends of the linkage arms connected thereto being displaceable connections extending in a common direction to permit both relative pivotal movement between the linkage arms of each pair and relative translational movement between all the linkage arms and said one frame, and a motion limiting resilient coupling including an anchoring spring of limited expansion and contraction connected between said one frame and the linkage arm system to permit relative translational movement along said common direction between the whole linkage arm system and said one frame within the limits of expansion and contraction of the spring thereby reducing the transmission of vibration in said common direction between the base frame and the seat frame. In particular, the resilient coupling includes a manually operable locking device connected between said one frame and at least one linkage arm which, in its inoperative state, permits said relative translational movement between said one frame and the linkage arm system under the restraint of the anchoring spring, and in its operative state locks said one frame to at least one said linkage arm to prevent said relative translational movement. BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of a spring suspension in accordance with the present invention will now be described by way of example only with reference to the accompanying drawings in which: FIG. 1 is a side elevation of a vehicle seat incorporating a scissor-action linkage arm suspension to which the present invention is directed; FIG. 2 is a plan view of the spring suspension, in accordance with the present invention, shown in FIG. 1; FIG. 3 is a section on the line III--III of FIG. 2, showing the suspension in its down-stop position; FIG. 4 is a side elevation of the spring suspension of FIG. 2 seen from the right-hand side of FIG. 2; and FIG. 5 is a front view of the spring suspension of FIG. 2. DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the drawings, the spring suspension, in the basic form shown in FIG. 1, comprises a base frame 11, a seat frame 12 on which a seat part 10 can be mounted, and two horizontally spaced pairs of scissor-action linkage arms 13, 14 (only one pair being seen in FIG. 1), the linkage arms 13, 14 having pivotal connections 15, 16 at their forward ends to the base frame 11 and seat frame 12 respectively, and further pivotal connections 17, 18 at their rearward ends to the seat frame 12 and base frame 11 respectively. Only one each of connections 15-18 are seen in FIG. 1. The arms 13, 14 of each pair are pivotally interconnected on the common scissors axis at their intersection 20. A torsion bar spring 22, for biassing the seat frame away from the base frame, is mounted within a torsion bar tube 23 which is rigidly secured to the upper forward ends of linkage arms 14. The opposite ends of tube 23 are journalled in bearings in the sides of the seat frame, these bearings forming the pivotal connections 16. The torsion bar spring 22 is secured at one end thereof to one end of the tube 23 and at its opposite end to the seat frame 12 via a manually-operable preload-adjusting screw mechanism 24 by operation of which the preload in the torsion bar can be varied. The details of the screw mechanism 24 form no part of the present invention but are described in the above-mentioned Patent Specification. In the suspension shown in FIG. 1, the upper ends of linkage arms 13 are interconnected by a transverse shaft 25 whose ends 26 support rollers 27. The rollers 27 engage in guides 28 mounted on and extending longitudinally of the seat frame 12 to permit relative sliding movement between the upper ends of arms 13 and the seat frame 12. Sliders could be used throughout instead of rollers. Similarly, pivot pins 30 are provided on the lower ends of linkage arms 14 to support rollers 31 engaging in guides 32 which permit relative sliding movement in the fore and aft direction between the lower ends of linkage arms 14 and the base frame 11. Although, in the prior art suspension illustrated in the above-mentioned Patent, the pivotal connections 15 between linkage arms 13 and base frame 11 were fixed pivotal connections, in the present embodiment, these connections are formed as sliding connections, and a motion limiting coupling device, including an anchoring spring, is connected between the linkage arm system and the base frame to provide vibrational isolation yet limit relative translational movement therebetween. In particular (as shown in FIG. 2) a transverse shaft 33 interconnects the lower ends of linkage arms 13, the shaft 33 having its opposite ends 34 engaging in rollers 35 which roll in guides 36. The motion limiting device takes the form of a shaft 40 which extends along the fore and aft centre line of the seat and is located in a flexible bush 41 at the rear of the base frame and a flexible bush 42 at the front of the base frame, and is connected to a split bearing 43 which embraces the transverse shaft 33. As shown, the shaft 40 is formed of two parts separated by the bearing 43. The forward and rear flexible bushes 42,41 have high lateral stiffness and low vertical stiffness so that the main support for the suspension is through the rollers 31, 35 and is not influenced by the support of the central shaft 40. Any "yawing" tendency of the suspension is resisted by the high lateral stiffness of the bushes 41, 42. The shaft 40 also supports two apertured spring-supporting plates 44, 45 between which a helical spring 46 is compressed, the plates 44, 45 being secured against movement away from each other by pins 47, 48 passing through the shaft 40. Movement of the plate 44 in a rearward direction and movement of plate 45 in a forward direction is prevented by two locating plates 50, 51, mounted on the base frame and having upturned supporting lugs 50',51' having apertures through which the shaft passes and within which stepped portions of plates 44, 45 are received. It will be seen therefore that if a vibration applied to the base frame 11 causes it to move forwardly relative to the seat part 10, the transverse shaft 33 moves in a rearward direction relative to base frame 11, and this movement is transmitted through bearing 43 and shaft 40 to plate 48. Plate 48 thus moves rearwardly against the force of spring 46 which is supported through plate 44 on the upturned lug 50' of plate 50. Conversely, if base frame 11 moves rearwardly relative to seat part 10, the relative movement of shaft 33 is forwardly, and this movement is transmitted through bearing 43 and shaft 40 to plate 44 which moves forwardly against the force of spring 46, the latter being supported in this case by plate 45 bearing aganst lug 51'. The movement therefore of shaft 33 and hence of the entire linkage arm system in a forward or rearward direction is opposed by spring 46 and limited in extent to the extent by which resilient buffers 71, 72 mounted on the shaft 40 can move toward stops 73, 74 formed by flanges on the base frame 11. This limited movement of the linkage arm system enables vibrations acting in the fore and aft directions to be at least partially absorbed by spring 46, or in other words spring 46 acts to isolate the seat frame, at least in part, from fore and aft vibrations applied to the base frame. In order to lock out the vibration isolator formed by the above-mentioned motion limiting device, a locking device is provided to act between shaft 40 and base frame 11. This locking device comprises a rotary locking latch 55 mounted in a sleeve 56 secured on the forward end of shaft 40 between locating pins 57, 58. These pins 57, 58 locate the sleeve 56 axially yet permit it to be rotated relative to the shaft 40. A handle 60 formed with an operating knob 61 is secured to the sleeve 56 to permit rotation of the sleeve and hence rotation of the latch 55. A spaced pair of plates 62 positioned on opposite sides of the forward end of shaft 40 and secured to the base frame 11 are recessed adjacent their forward end to form catches co-operable with the latch 55. In one rotational position of the latch 55, the catches engage and lock the latch 55 to the plates 62 and thus prevent longitudinal movement of shaft 40 relative to the base frame. By rotation of handle 60, the latch 55 can be rotated out of engagement with the catches of the plates 62 into a position in which longitudinal movement of shaft 40 is permitted to allow the vibration isolator to be effective. An over-centre spring 70 is provided between a point on the handle 60 and a bracket 75 fixed to the end of shaft 40 so that the latch 55 is biassed by the spring 70 into its engaged position in the plates 62 or into its disengaged position depending on which side of the centre position the spring 70 is located. Although the suspension has been described as located with the handle 60 at the front, it may on occasion be desired that the suspension as shown in FIG. 2 be reversed relative to the seat part so that handle 60 is at the rear. In a modification, not shown, the shaft 33 is split and secured at the adjacent ends to a supporting block which replaces bearing 43, and in this case the shaft 40 is formed in one piece and passed through this supporting block. Although the suspension has been illustrated and described in a form in which the resilient coupling is connected between the linkage arm system and the base frame, it could alternatively be located between the linkage arm system and the seat frame. In the latter event, the biassing spring would act between the seat frame and one of the linkage arms.

A vehicle seat suspension, of the type comprising a seat frame supported on a base frame by two spaced pairs of scissor action linkage arms, has the ends of the linkage arms connected to one of the frames wholly by pivotal connections having freedom for displacement longitudinally of the suspension and a resilient coupling connecting the one frame to one of the linkage arms to damp the transmission of vibrations between the frames in the longitudinal direction.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to a liquid coating machine of a rotary screen printing press or the like. [0003] 2. Description of the Related Art [0004] In screen printing by a rotary screen printing press, ink is placed in a screen printing forme, and the screen printing forme is pressed against paper by a squeegee or a doctor roller to transfer the ink to a printing surface of the paper through the openings of the screen printing forme. The screen printing forme needs to be replaced each time a different printing product is to be printed. [0005] The work of replacing the screen printing forme will be described, for example, in connection with an intaglio and rotary screen printing press as shown in FIG. 6 . [0006] In this printing press (liquid coating machine), sheets of paper (sheets, for short) W are fed one by one from a feeder 10 onto a feedboard 11 . Then, the sheet W is passed from a swing arm shaft pregripper 12 on to a transfer cylinder 13 , and then gripped by grippers 14 a of an impression cylinder 14 for the purpose of transport (transport means). On the other hand, conventional inks are supplied from within ink fountains 20 to chablon rollers 17 via ink fountain rollers 19 and intermediate rollers 18 , and supplied to an ink collecting cylinder 16 (other device). Then, the inks are collectively supplied to an intaglio plate of a plate cylinder 15 . Also, special ink is directly supplied, in a constant amount in a predetermined pattern, from within a rotary screen cylinder (stencil printing cylinder) 22 to the intaglio plate of the plate cylinder 15 via a rubber roller 21 (liquid coating unit). [0007] These inks have their surplus amounts removed by a wiping roller 23 , and are then transferred to the sheet W passed on to the impression cylinder 14 for the purpose of printing. The printed sheet W is transported and delivered by a delivery chain 26 via a delivery cylinder 25 . [0008] In such a rotary screen printing press, when the screen printing forme (stencil printing plate) of the rotary screen cylinder 22 is to be replaced, it has been common practice for two operators to hold opposite end portions of the screen printing forme in places near entrances 28 to the machine. This is because a forme or plate replacing work space S for replacing the screen printing forme of the rotary screen cylinder 22 has its upper side closed with a printing unit or a transport unit for the sheet W, and has its fore-and-aft direction restrained by other printing devices. Thus, the space S is only a narrow space defined by these printing devices. Moreover, the machine entrances 28 formed on both sides of a machine frame 27 are narrow. These situations make it difficult for one operator to do replacing work while holding the screen printing forme. [0009] Thus, the two operators have to do the work in a well-coordinated manner with an unnatural posture, thus posing the problems of decreasing the operators' work efficiency and imposing a burden on the operators. SUMMARY OF THE INVENTION [0010] The present invention has been proposed in light of the above-described problems. It is an object of the invention to provide a liquid coating machine by which only one operator is required to do the work of replacing a stencil printing plate with ease. [0011] An aspect of the present invention is a liquid coating machine including transport means for transporting a sheet, a stencil printing cylinder, provided below the transport means, for coating a liquid on the sheet transported by the transport means, and a plate replacing work space whose upper side is closed, with respect to which a transport direction of the sheet is restrained by other device and a liquid coating unit including the stencil printing cylinder, which is open in at least one of directions orthogonal to the transport direction of the sheet, and where an operator performs work of replacing a stencil printing plate, the liquid coating machine comprising a plate rest provided below the stencil printing cylinder and supported to be movable to a first position within the liquid coating unit and a second position within the plate replacing work space. [0012] The plate rest may be supported by a horizontal movement guide member to be movable to the first position and the second position. [0013] A rolling body may be provided on a surface on a side of the plate rest supporting the stencil printing plate, and the stencil printing plate may be supported via the rolling body. [0014] The liquid coating machine may further comprise a four-joint link for supporting the plate rest, and drive means for swinging the four-joint link, and the plate rest may be moved to the first position and the second position by the drive means via the four-joint link. [0015] An ink pan may be supported by the plate rest, and the stencil printing plate may be supported by the plate rest via the ink pan. [0016] A pair of plate bearers having inclined surfaces opposing each other may be integrally formed on an upper surface of the ink pan, and the stencil printing plate may be supported on the inclined surfaces of the plate bearers. [0017] A pair of plate bearers having a plurality of rolling bodies annexed thereto may be integrally formed on an upper surface of the ink pan, and the stencil printing plate may be supported by the rolling bodies of the plate bearers. [0018] The plate rest may be moved to reciprocate between the first position and the second position during the work of replacing the plate. [0019] According to the liquid coating machine concerned with the present invention, one operator is enough to perform the work of replacing the stencil printing plate easily, by using the plate rest, while avoiding the expansion of the plate replacing work space or the machine entrance of the frame. BRIEF DESCRIPTION OF THE DRAWINGS [0020] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: [0021] FIG. 1 is a schematic configurational sectional view of a rotary screen printing unit in a rotary screen printing press showing Embodiment 1 of the present invention; [0022] FIG. 2 is a schematic right side view of the rotary screen printing unit in FIG. 1 ; [0023] FIG. 3 is a perspective view of a slide rail; [0024] FIG. 4 is an explanation drawing using a four-joint link and drive means (air cylinder) showing Embodiment 2 of the present invention; [0025] FIG. 5A is an explanation drawing using rolling bodies (rollers) showing Embodiment 3 of the present invention; [0026] FIG. 5B is an explanation drawing using the rolling bodies (rollers) showing the Embodiment 3 of the present invention; and [0027] FIG. 6 is a schematic configurational view of a conventional intaglio and rotary screen printing press. DETAILED DESCRIPTION OF THE INVENTION [0028] A liquid coating machine according to the present invention will be described in detail by embodiments with reference to the accompanying drawings. Embodiment 1 [0029] FIG. 1 is a schematic configurational sectional view of a rotary screen printing unit in a rotary screen printing press showing Embodiment 1 of the present invention. FIG. 2 is a schematic right side view of the rotary screen printing unit in FIG. 1 . FIG. 3 is a perspective view of a slide rail. [0030] In a rotary screen printing unit in a rotary screen printing press (liquid coating machine), as shown in FIG. 1 , a rotary screen cylinder (stencil printing cylinder) 32 is supported between right and left frames 31 erected on a bed 30 via eccentric bearings 33 to be capable of throw-on and throw-off with respect to a rubber roller, an impression cylinder, etc. (not shown). The right and left eccentric bearings 33 are supported by the right and left frames 31 to be pivotable and slidable in the lateral direction (axial direction). [0031] The rotary screen cylinder 32 comprises a cylindrical screen printing forme (stencil printing plate) 35 supported between right and left tubular end members 34 , and in small-diameter parts of the right and left tubular end members 34 , is also supported by the eccentric bearings 33 to be rotatable via bearings 36 . The screen printing forme 35 comprises a mesh-shaped body portion 35 a , and tubular mounting members 35 b attached to the opposite ends of the body portion 35 a. [0032] A toothing 34 a is engraved in the outer periphery of the small-diameter part of the right tubular end member 34 , and a gear 37 meshes with the toothing 34 a . Thus, the rotary screen cylinder 32 is rotationally driven, and can be circumferentially registered, by a motor (not shown) via the above-mentioned gear mechanism. [0033] In a slot formed in a flange portion 33 a of each of the right and left eccentric bearings 33 , a head 38 a of a bolt 38 is fitted to be rotatable and movable in the major-diameter direction of the slot, but immovable in the axial direction of the slot A threaded portion 38 b of the bolt 38 is screwed into a threaded bore of the frame 31 . A gear 39 a is secured to each of the heads 38 a of the right and left bolts 38 , and a gear 39 b secured onto an output shaft of a motor 40 meshes with each of the gears 39 a . The right and left motors 40 are mounted on support brackets 41 bound to the right and left frames 31 . [0034] Thus, the right and left eccentric bearings 33 are slid in the lateral direction (axial direction) by the motor 40 via the aforementioned gear mechanism and feed screw mechanism to permit the tension adjustment of the screen printing forme 35 and the movement of the bearings during removal of the screen printing forme 35 . [0035] A pipe-shaped support shaft 42 closed at a right end is inserted through the rotary screen cylinder 32 , and a rubber squeegee (not shown) is supported by the support shaft 42 . The leading end of this squeegee makes sliding contact with the inner peripheral surface of the screen printing forme 35 (body portion 35 a ) Thus, the ink (liquid) supplied through the interior of the support shaft 42 into the screen printing forme 35 is transferred onto a printing surface of the sheet via the openings of the body portion 35 a. [0036] In the present embodiment, as shown in FIG. 2 as well, a quadrilateral frame-shaped forme or plate rest 50 having a withdrawing grip 51 annexed to each of right and left front parts thereof is disposed on the bed 30 , which is located below the rotary screen cylinder 32 in the assembled state, via slide rails 55 and angle members 56 to be described later. [0037] An ink pan 53 , which receives ink dripping from the screen printing forme 35 of the rotary screen cylinder 32 during printing and during stoppage of printing, is placed on the forme rest 50 . A pair of (i.e., front and rear) forme or plate bearers 52 having inclined surfaces 52 a opposing each other are formed integrally with the ink pan 53 . A pull-out grip 54 is annexed to each of right and left parts of the ink pan 53 (the pull-out grip 54 may be provided at one of the right and left parts corresponding to one of machine entrances 31 a to be described later). [0038] The forme rest 50 is supported by the right and left (paired) slide rails (horizontal movement guide members) 55 to be movable from the aforementioned position (a first position within the liquid coating unit, as indicated by solid lines in FIG. 2 ) to a second position (a position indicated by dashed double-dotted lines in FIG. 2 ) within a forme or plate replacing work space S which an operator can go into and out of through the machine entrance 31 a formed in at least one of the right and left frames 31 . [0039] The slide rail 55 , as shown in FIG. 3 , comprises a moving rail 55 a , a stationary rail 55 b , and an intermediate rail 55 c slidably fitted to both of the moving rail 55 a and the stationary rail 55 b . The moving rail 55 a is fixed to the right and left parts of the forme rest 50 , while the stationary rail 55 b is fixed to the pair of (i.e., right and left) L-shaped angle members 56 laid in the fore-and-aft direction on the bed 30 . [0040] The slide rail 55 has a locking mechanism (not shown) for locking and unlocking in the most contracted state at the first position within the liquid coating unit, and in the most extended state at the second position within the forme replacing work space S. [0041] Because of the above-described features, the following work procedure is performed in replacing the screen printing forme 35 for printing a different printing product: [0000] (1) First of all, the operator enters the forme replacing work space S through the machine entrance 31 a , and then while pressing the used screen printing forme 35 , operates a switch for moving the tubular end members 34 at the opposite ends of the rotary screen cylinder 32 outwards by driving of the motors 40 , thereby moving the tubular end members 34 outwards, and also detaching the used screen printing forme 35 from the tubular end members 34 . Then, the operator places the used screen printing forme 35 on the inclined surfaces 52 a of the forme bearers 52 of the ink pan 53 placed on the forme rest 50 . (2) Then, the operator grasps the withdrawing grips 51 , and moves the forme rest 50 , together with the ink pan 53 , from the first position within the liquid coating unit toward the second position within the forme replacing work space S. During this movement, the operator goes out of the forme replacing work space S through the machine entrance 31 a. (3) Then, the operator removes the used screen printing forme 35 placed on the ink pan 53 on the forme rest 50 located at the second position within the forme replacing work space S. On this occasion, if the screen printing forme 35 is severely soiled, for example, the pull-out grips 54 may be grasped, and the screen printing forme 35 may be taken out of the machine together with the ink pan 53 . (4) Then, the operator places another screen printing forme 35 , which is used in subsequent printing, on the inclined surface 52 a of the forme bearers 52 of the ink pan 53 on the forme rest 50 . (5) Then, the operator grasps the withdrawing grips 51 , and moves the forme rest 50 , together with the ink pan 53 , from the second position within the forme replacing work space S to the first position within the liquid coating unit. (6) Finally, the operator enters the forme replacing work space S through the machine entrance 31 a , and while pressing the screen printing forme 35 to be used in subsequent printing, operates a switch for moving the tubular end members 34 at the opposite ends of the rotary screen cylinder 32 inwards by driving of the motors 40 , thereby moving the tubular end members 34 inwards, and also allowing the tubular end members 34 to support the screen printing forme 35 to be used in subsequent printing. [0042] Since the screen printing forme 35 is replaced in the above-mentioned manner, one operator is enough to perform the work of replacing the screen printing forme 35 easily, by using the forme rest 50 , even if the forme replacing work space S or the machine entrance 31 a of the frame 31 is narrow, in other words, without the need to widen the space S or the entrance 31 a . Moreover, the machine can be downsized. [0043] Furthermore, since the ink pan 53 is present, it brings the advantages that it can serve as an ink receptacle if an ink scatter, for example, occurs during printing, and that it can be carried to a utility room without the need for holding a dirty screen printing forme 35 at the time of replacement. Of course, the ink pan 53 may be omitted. [0044] In the present embodiment, the forme rest 50 may be automatically withdrawn by an air cylinder or the like, instead of being withdrawn by the withdrawing grips 51 . [0045] Moreover, the horizontal movement guide member, such as a mere slide table, other than the slide rails 55 , may be used. Embodiment 2 [0046] FIG. 4 is an explanation drawing using a four-joint link and a drive means (air cylinder) showing Embodiment 2 of the present invention. [0047] This is an embodiment in which the forme rest 50 can be moved between the first position within the liquid coating unit and the second position within the forme replacing work space S by air cylinders (drive means) 58 via four-joint links 57 instead of the slide rails 55 as the horizontal movement guide members of Embodiment 1. [0048] The above feature obtains the advantage that the replacing work can be performed more promptly, in addition to the same actions and effects as those in Embodiment 1. [0049] In the present embodiment, it is possible to substitute the air cylinder 58 by a gas damper without using the air cylinder 58 , attach an operating lever to the fulcrum, and provide a stopper at the position of attachment and detachment, thereby converting the mode of operation into a manual mode. Embodiment 3 [0050] FIGS. 5A and 5B are explanation drawings using rolling bodies (rollers) showing Embodiment 3 of the present invention. [0051] This is an embodiment in which many rollers (rolling bodies) 60 are discretely arranged in the longitudinal direction on the forme bearers 52 of Embodiment 1. [0052] The above feature obtains the advantage that the screen printing forme 35 can be easily withdrawn from and placed in the machine, in addition to the same actions and effects as those in Embodiment 1. [0053] While the present invention has been described in the foregoing fashion, it is to be understood that the invention is not limited thereby, but may be varied in many other ways. For example, the present invention can be applied to machines other than the rotary screen printing press, such as a stencil printing press and a coating machine for supplying varnish instead of ink and performing coating instead of printing. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the appended claims.

A rotary screen printing press, which includes a rotary screen cylinder for coating ink on a sheet transported by transport means, and a plate or forme replacing work space whose upper side is closed, with respect to which a transport direction of the sheet is restrained by other device and a liquid coating unit including the rotary screen cylinder, which is open in at least one of directions orthogonal to the transport direction of the sheet, and where an operator performs work of replacing a screen printing forme, comprises a plate or forme rest provided below the rotary screen cylinder and supported to be movable to a first position within the liquid coating unit and a second position within the forme replacing work space.

BACKGROUND OF THE INVENTION (1) Field of the Invention The present invention relates to a heat-sensitive recording element. More particularly, the present invention relates to a heat-sensitive recording element in which a starch partially esterified with an organic carboxylic acid is used as a polymeric binder for dispersing and binding a leuco pigment and an organic acidic substance. (2) Description of the Prior Art The silver salt photographic process, the diazo photographic process, the electrophotographic process and other electric recording processes have heretofore been utilized as means for recording informations. Recently, the thermographic recording process has been noted as the recording process in which a visible image can be directly obtained without performing development and fixation treatments. A recording element comprising a recording layer formed on a substrate, said recording layer comprising a leuco pigment which is colorless or light-colored in the normal state, an organic acidic substance which is solid at normal temperatures but is fusible under heating, and a polymeric binder in which said leuco pigment and organic acidic substance are dispersed, is broadly used as the recording element for the thermographic recording process. Water-soluble substances capable of dispersing the organic acidic substance and leuco pigment therein without dissolving them are ordinarily used as the polymeric binder. Various starches and starch derivatives such as hydroxyethyl starch, hydroxypropyl starch, carboxymethyl starch, oxidized starch and soluble starch have been known as polymeric binders which meet the above requirement and are available at low costs. However, certain defects are commonly observed when these starches and starch derivatives are used. For example, since starch or starch derivative is a nutrient for microorganisms, an aqueous solution of a starch or starch derivative readily gets moldy when the aqueous solution is stored. Most of starches and starch derivatives are easily soluble in hot water, but hot water solutions of starches or starch derivatives are readily gelatinized when they are cooled. When a starch derivative not having such tendency is used, the water resistance of the resulting recording layer is extremely poor, and if the recording layer falls in contact with water, flow-out or bleeding of the image is readily caused. Moreover, starches and starch derivatives which have been heretofore used in this field are not satisfactory in such properties as the property of dispersing and binding a leuco pigment and an acidic substance, the easily defoaming property and the water resistance. SUMMARY OF THE INVENTION It was found that when a starch partially esterified with an organic carboxylic acid is selected among various starch derivatives and is used as the polymeric binder for formation of a heat-sensitive recording layer, the abovementioned defects involved in the conventional starch or starch derivative binders can be eliminated. In accordance with the present invention, there is provided a heat-sensitive recording element comprising a substrate and a recording layer formed on said substrate, said recording layer comprising a leuco pigment, an organic acidic substance which is solid at normal temperatures and is fusible under heating, and a polymeric binder in which said leuco pigment and organic acidic substance are dispersed, wherein said polymeric binder is a starch partially esterified with an organic carboxylic acid. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The starch partially esterified with an organic carboxylic acid (hereinafter referred to as "CPES"), that is used in the present invention, is characterized in that even if it is stored for a long time in the form of an aqueous solution, molds such as blue mold and white mold are not formed and it is very excellent in the storage stability. Furthermore, CPES is easily soluble in hot water, and even if a hot water solution is cooled to room temperature, gelation is not caused and a heat-sensitive recording layer formed from this solution is much excellent in the water resistance over heat-sensitive recording layers formed from solutions of other starch derivatives. CPES that is used in the present invention is characterized in that a leuco pigment and an organic acidic substance can be dispersed in the finely divided form in CPES without gelation of CPES as the binder or agglomeration or coarsening of dispersed particles. Accordingly, a color of a high density can be formed on heating for coloration. Furthermore, the adhesion of the recording layer to the substrate is remarkably strong and the cohesive force of the recording layer per se is very high. Still further, the solution of CPES has a relatively low viscosity and has no bubbling property, and the solution of CPES has a good adaptability to the coating operation. CPES that is used in the present invention is a known substance and can easily be obtained by partially acylating starch with an anhydride of an organic carboxylic acid. As the organic carboxylic acid, there are preferably used monocarboxylic acids having up to 6 carbon atoms, such as formic acid, acetic acid, propionic acid and butyric acid. Dibasic acids such as succinic anhydride, maleic acid, fumaric acid and phthalic anhydride or aromatic monocarboxylic acids such as benzoic acid and phenylacetic acid may be used singly or in the form of mixtures with lower monocarboxylic acids. It is important that the esterified starch that is used in the present invention should be partially esterified with an organic carboxylic acid. An esterified starch in which all of hydroxyl groups (three hydroxyl groups) of the glucose unit are esterified (acylated) is completely insoluble in water and this starch cannot be used for attaining the objects of the present invention. CPES especially suitable for attaining the objects of the present invention is one having 0.01 to 0.2 acyl group (ester group), especially 0.02 to 0.1 acyl group, per glucose residue on the average (hereinafter referred to as "substitution degree"). If the number of the acyl group is smaller than 0.01 per glucose residue, the mold resistance and solubility are insufficient, and if the number of the acyl group is larger than 0.2 per glucose residue, the water resistance and viscosity characteristic are not satisfactory. All of leuco pigments that have heretofore been used for heat-sensitive recording papers can be used in the present invention. For example, there may be used triphenylmethane type leuco pigments, fluoran type leuco pigments, spiropyran type leuco pigments, rhodamine lactam type leuco pigments, auramine type leuco pigments and phenothiazine type leuco pigments. These leuco pigments may be used singly or in the form of mixtures of two or more of them. Preferred examples of these leuco pigments are described below. Triphenylmethane Type Leuco Pigments 3,3-Bis-(p-dimethylaminophenyl)phthalide, 3,3-bis-(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3,3-bis-(p-dimethylaminophenyl)-6-diethylaminophthalide, 3,3-bis-(p-dimethylaminophenyl)-6-methoxyphthalide, 4-hydroxy-4'-dimethylaminotriphenylmethane lactone and 4,4'-bis-dihydroxy-3,3'-bis-diaminotriphenylmethane lactone. Fluoran Type Leuco Pigments 3-Dimethylamino-5,7-dimethylfluoran, 3-diethylamino-5,7-dimethylfluoran, 3-diethylamino-6,7-dimethylfluoran, 3-cyclohexylamino-6-chlorofluoran, 3-dimethylamino-6-methoxyfluoran, 3,6-bis-β-methoxyethoxyfluoran, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3,7-bis-diethylaminofluoran and 3-diethylamino-7-methoxyfluoran. Spiropyran Type Leuco Pigments 8'-Methoxybenzoindolinospiropyran, 3-phenyl-8'-methoxybenzoindolinospiropyran, 6'-chloro-8'-methoxybenzoindolinospiropyran, 5,6'-dichloro-8'-methoxybenzoindolinospiropyran, 4,7,8'-trimethoxybenzoindolinospiropyran, benzo-β-naphthospiropyran, 3-methyl-di-β-naphthospiropyran and 1,3,3-trimethyl-6'-chloro-8'-methoxyindolinobenzospiropyran. Rhodamine Lactam Type Leuco Pigments 9-(p-Nitroanilino)-3,6-bis-(diethylamino)-9-xanthyl-o-benzoic acid lactam and 2-[3,6-bis-(diethylamino)-9-(o-chloroanilino)xanthyl]-benzoic acid lactam. Auramine Type Leuco Pigments 2,5-Dichloro-N-phenylleucoauramine, 4,4'-bis-dimethylamino-3,4-chlorophenylleucoauramine and 4,4'-bis-dimethylaminopiperazine-hydrol. Phenothiazine Type Leuco Pigments Benzoylleucomethylene blue, p-chlorobenzoylleucomethylene blue, 3,4-dichlorobenzoylleucomethylene blue and p-methoxybenzoylleucomethylene blue. An organic acidic substance which is solid at normal temperatures and is fusible under heating is selected among organic acidic substances customarily used for formation of heat-sensitive recording papers and is used in combination with a leuco pigment such as mentioned above. As specific examples, there can be mentioned 4,4'-isopropylidenediphenol, 4,4'-methylene-bis-(2,6-tert-butylphenol), 4,4'-isopropylidene-bis-(2-chlorophenol), 4,4'-isopropylidene-bis-(2,6-dichlorophenol), 4,4'-isopropylidene-bis-(2,6-dimethylphenol), 4,4'-isopropylidene-bis-(2-tert-butylphenol), 4,4'-sec-isobutylidene-bis-(2-methylphenol), 4,4'-cyclohexylidenediphenol, 2,2'-thio-bis-(4,6-dichlorophenol), p-tert-butylphenol, 3,4-dichlorodiphenol, 0,0'-diphenol, 4-hydroxydiphenoxide, 2,2'-dihydroxybisphenol, 2,2'-methylene-bis-(4-chlorophenol), 2,6-dihydroxybenzoic acid and 1-hydroxy-2-naphthoic acid. In the present invention, it is preferred that the leuco pigment be used in an amount of 30 to 70% by weight (all of "%" and "parts" given hereinafter are by weight), especially 40 to 60%, based on the CPES binder, and that the organic acidic substance be used in an amount of 100 to 400%, especially 150 to 350%, based on the CPES binder. Known additives may be added in known amounts so as to improve various properties of the heat-sensitive recording layer. For example, a white pigment such as titanium dioxide or a filler such as clay or calcium carbonate may be incorporated so as to improve the whiteness of the recording layer or increase the volume of the recording layer. Furthermore, animal, vegetable and mineral waxes such as paraffin wax and carnauba wax, fatty acids and their derivatives such as stearic acid, various soaps and fatty acid amides and synthetic waxes such as polyethylene wax, polypropylene wax and polyethylene glycol may be incorporated so as to adjust the recording sensitivity. Alkanol amines such as triethanol amine and other organic bases may be incorporated so as to prevent coloration of the background (background coloration). A water resistance improver and a defoaming agent may be incorporated if desired, though in the present invention it is ordinarily unnecessary to use such additives. A coating composition for formation of the heat-sensitive recording layer may preferably be prepared by dissolving the CPES binder in hot water, cooling the formed solution, dispersing the leuco pigment and the organic acidic substance separately into the solution to form 2 dispersions and mixing them before the coating operation. As the substrate on which the recording layer is to be formed, there can optionally be used papers, non-woven fabrics, artificial papers, films, metal foils and laminates thereof. It is preferred that the recording layer be formed so that the dry base weight is 2 to 10 g/m 2 , especially 3 to 8 g/m 2 . The heat-sensitive recording element of the present invention is valuable as a recording element for use in facsimile, printers, data communication, computer terminals, measuring instruments, passometers and copying machines including a thermal heat, a heat pen, an infrared flash lamp or a laser device as a heat source. The present invention will now be described with reference to the following Examples that by no means limit the scope of the invention. Incidentally, all of "parts" and "%" are by weight in these Examples. EXAMPLE 1 One part of crystal violet lactone was dispersed in 6.8 parts of a 5% aqueous solution of a binder to form a liquid A. Separately, 5 parts of 4,4'-isopropylidenephenol was dispersed in 34 parts of a 5% aqueous solution of the binder to form a liquid B. The two liquids were sufficiently stirred in ball mills for 10 hours separately, and they were mixed together to form a homogeneous coating composition. The coating composition was coated on high quality paper (base paper for a diazo type photosensitive sheet) by using a wire bar so that the dry base weight of the coating was about 4.5 g/m 2 . The coating was dried at 60° C. for 5 minutes and was then naturally dried at room temperature. Seven binders shown in Table 1 were used as the binder. Water was added to the liquid A or B according to need, so that the viscosity of the coating composition was adjusted to a level suitable for the coating operation. The so-prepared heat-sensitive recording sheet was passed through between heating rollers maintained at 120° C. or 140° C. and moved at a linear speed of 4 cm/sec to effect coloration. The coloring state and other properties of the heat-sensitive recording sheet were examined to obtain results shown in Table 1. The adhesion was evaluated based on results of the peeling test using an adhesive cellophane tape. The coloration density was measured through a red filter by using a reflection densitometer (model PDA-65 manufactured by Konishiroku Shashin Kogyo). TABLE 1__________________________________________________________________________ Disper- Defoaming Background Coloration DensityRun No.Binder sibility Property Adhesion Coloration 120° C. 140° C.__________________________________________________________________________1 polyvinyl alcohol X X O O 0.23 0.972 polyacrylamide O X O O 0.24 0.793 starch esterified with O O O O 0.44 1.07acetic acid (substitu-tion degree = 0.02)4 crosslinked starch O X Δ O 0.33 0.975 corn starch O X O O 0.41 1.006 acrylic resin emulsion O Δ O X 0.76 0.907 ethylene-vinyl chloride O Δ O X 0.69 1.08copolymer emulsion__________________________________________________________________________ Note- O: good Δ: ordinary X: bad The used binders were the following commercially available products. Polyvinyl alcohol: Gosenol GL-50 manufactured by Nihon Gosei Kagaku Kogyo Polyacrylamide: Product manufactured by Yoneyama Yakuhin Kogyo Acetic acid-esterified starch: Product manufactured by Nichiden Kagaku Crosslinked starch: Product manufactured by Nichiden Kagaku Acrylic resin emulsion: Acryl Emulsion HD-3 manufactured by Toa Gosei Kagaku Ethylene-vinyl chloride copolymer emulsion: Product manufactured by Sankyo Kasei Corn starch: Product supplied by Nichiden Kagaku EXAMPLE 2 Heat-sensitive recording sheets were prepared in the same manner as described in Example 1 except that acetic acid-esterified starch having a substitution degree different from that of the esterified starch used in Example 1 or hydroxypropylated starch (product manufactured by Nichiden Kagaku) was used as the binder. Each sheet was passed through between heating rolls maintained at 150° C. and moved at a linear speed of 4 cm/sec. The colored sample was dipped in water maintained at 25° or 50° C. for 90 seconds to examine the water resistance. More specifically, the coloration density was measured before and after the dipping treatment and the water resistance was evaluated based on the residual ratio of the coloration density. Furthermore, the aqueous solution of the binder was stored at 30° C. for 10 days and formation of molds was checked. The obtained results are shown in Table 2. TABLE 2__________________________________________________________________________ After Dipping at 25° C. After Dipping at 50° MoldRun Coloration Density Coloration Residual Coloration Residual Resis-No. Binder Before Dipping Density Ratio (%) Density Ratio (%) tance__________________________________________________________________________1 polyvinyl alcohol 1.12 0.91 81.3 0.75 67.0 O2 hydroxypropylated starch 1.11 0.95 85.6 0.80 72.1 X3 acetic acid-esterified 1.15 1.11 96.5 0.95 82.6 Δ starch (substitution degree = 0.01)4 acetic acid-esterified 1.20 1.18 98.3 1.02 85.0 O starch (substitution degree = 0.03)5 acetic acid-esterified 1.20 1.15 95.8 0.98 81.7 O starch (substitution degree = 0.05)6 acetic acid-esterified 1.20 1.15 95.8 0.95 79.2 O starch (substitution degree = 0.08)__________________________________________________________________________ Note- X: formation of molds observed Δ: formation of molds not observed but precipitates O: formation of molds or precipitates not observed EXAMPLE 3 Heat-sensitive recording sheets were prepared by using acetic acid-esterified starches differing in the substitution degree, which were used in Example 2 and 3-dimethylamino-6-methyl-7-anilinofluoran as the leuco pigment in the same manner as described in Example 2. When these heat-sensitive recording sheets were passed through between heating rolls maintained at 140° C. and moved at a linear speed of 4 cm/sec, black images having a reflection density of 1.1 (as determined by using a neutral filter) were obtained on all the heat-sensitive recording sheets. Heat-sensitive recording sheets were prepared in the same manner as described above except that 2.7 parts of a polyethylene emulsion (Chemipar W; solid content=37%; manufactured by Mitsui Sekiyu Kagaku) was added to the coating composition. When these heat-sensitive recording sheets were used for printing using a thermal head, it was found that clear images free of bleeding in copied letters or patterns were obtained and these heat-sensitive recording sheets had excellent recording characteristics and their water resistance was highly improved.

Disclosed is a heat-sensitive recording element comprising a recording layer including a starch partially esterified with an organic carboxylic acid as a polymeric binder for dispersing therein a leuco pigment and an organic acidic substance. This recording element provides a recorded image excellent in the water resistance and recording characteristics when it is used for thermographic recording. An aqueous solution of this partially esterified starch has a good storage stability and it does not get moldy even if it is stored for a long time.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of application Ser. No. 09/276,063, filed Mar. 25, 1999, now U.S. Pat. No. 6,286,212, entitled “Thermally Conductive Material and Method of Utilizing the Same”, which is a continuation-in-part of U.S. Ser. No. 08/654,701, filed May 29, 1996, now U.S. Pat. No. 5,930,893, issued Aug. 3, 1999, entitled “Thermally Conductive Material and Method of Using the Same.” BACKGROUND OF THE INVENTION This invention relates to a thermally conductive compound and method of constructing a low impedance, thermal interface/joint between an electronic component and a heat sink the compound having desired adhesive and closure force characteristics. Electrical components, such as semiconductors, transistors, etc., optimally operate at a pre-designed temperature which ideally approximates the temperature of the surrounding air. However, the operation of electrical components generates heat which, if not removed, will cause the component to operate at temperatures significantly higher than its normal operating temperature. Such excessive temperatures can adversely affect the optimal operating characteristics of the component and the operation of the associated device. To avoid such adverse operating characteristics, the heat should be removed, one such method being a conduction of the heat from the operating component to a heat sink. The heat sink can then be cooled by conventional convection and/or radiation techniques. During conduction, the heat must pass from the operating component to the heat sink either by surface contact between the component and the heat sink or by contact of the component and heat sink surfaces with an intermediate medium. In some cases, an electrical insulator must be placed between the component and heat sink. Thus, a heat-conducting path must be established between the component and the heat sink surfaces with or without an electrical insulator therebetween. The lower the thermal impedance of this heat conducting path the greater the conductivity of heat from the component to the heat sink. This impedance depends upon the length of the thermal path between the component and heat sink as well as the degree of effective surface area contact therebetween. As the surfaces of the heat sink and component are not perfectly flat and/or smooth, a full contact of the facing/mating surfaces is not possible. Air spaces, which are poor thermal conductors, will appear between these irregular mating surfaces and thus increase the path's impedance to conduction. It is thus desirable to remove these spaces by utilizing a heat conducting medium, the medium designed to contact the mating surfaces and fill the resulting air spaces. The removal of these air spaces lowers the path's thermal impedance and increases the path's thermal conductivity. Thus, the conduct of heat along the thermal path is enhanced. Mica insulators with silicone grease thereon, the silicone grease containing “heat conducting particles,” such as a metallic oxide, have been inserted between the component and heat sink to establish a thermal path. The grease can also be applied directly to the mating surfaces in an attempt to fill the resulting voids therebetween. However, the non-soluble grease is messy and can contaminate the equipment, clothing and personnel. Another proposed solution was to coat a polymeric insulating gasket with a metallic oxide thereon, the gasket being inserted between the component and heat sink during assembly. Such oxides can be expensive, toxic and adhesion to the gasket can be difficult. Moreover, the gasket may not fully mesh with the irregular mating surfaces of the component and heat sink resulting in undesirable, inefficient air spaces therebetween. The use of a compound comprising a paraffin wax with a softener such as petroleum jelly as the intermediate medium has been proposed in the Whitfield U.S. Pat. Nos. 4,299,715, 4,473,113, 4,466,483. The softener is intended to make the compound less brittle so it will not crack when coated onto the intermediate flexible insulator. However, this compound changes from a solid to a liquid state at the component's normal operating temperature which decreases its thermal conductivity. Also, the compound tends to flow away from the thermal path/joint which increases the impedance of the thermal path. Moreover, this flow can contaminate the surrounding surfaces. Also, the use of softeners makes the resulting compound more susceptible to abrasion or chemical solvents. Thus, the compound can be rubbed off its substrate carrier during handling or component cleaning. Also, the “blocking temperature” of the compound is lowered, i.e., the temperature at which the coated carriers will stick to each other. (If the blocking temperature is equal to or lower than the room temperature, the coated carriers will stick to each other.) Also, the softeners make the compound stickier which makes it difficult to manipulate and susceptible to collection of foreign matters thereon. Such foreign materials can lead to component malfunctions, if not failure. In response thereto I have invented a method of selecting a compound for establishing an efficient thermal joint between the surfaces of an electrical component and heat sink. With cognizance of a normal operating temperature of a selected component, the compound is selected to melt only during initial component operation by either external heat or a component temperature well above the component's normal operating temperature. Once initially liquified or sufficiently deformable, the clamping pressure of the component to the heat sink causes the compound to fill the spaces resulting in the thermal path between the heat sink and the component. This action presents a thermal path of low impedance which initiates an effective conduct of the heat from the component to the heat sink. The component temperature then falls to a temperature below the compound melt temperature and to its normal operating temperature which causes the compound to resolidify. Upon subsequent operation of the component, the component reaches only the components normal operating temperature as the previously established compound joint formed during initial component operation remains in a solid state. As the compound does not melt during subsequent component operation, a higher thermal conductivity is maintained. Moreover, as compounds of high molecular weight can be used in the above process, a higher thermal conductivity will result with or without the use of heat conductive particles. I have also invented a simple method of applying a compound to a heat sink which is simple, cost effective and easy to use. The method basically utilizes a rod of preselected compound and cross section which is depressed against the heat sink for a selected length of time to leave a deposit of material thereon. The selection of certain characteristics of the compound material constricts the deposit to the cross-sectional area of the rod. The method is not limited to the particular compounds described herein. As above discussed, the shorter the path between the component and heat sink the lower the thermal resistance. Thus, the lower the force required to reduce the thickness of the thermal compound interface the easier to reduce the thermal resistance of this path. This force must be coordinated with the closure force. By closure force I mean the aforementioned clamping pressure/force needed to initially join the component, thermal interface and heat sink. It is known to have a film, e.g., a diamond film, along the component interface which serves as a “heat spreader”. Any localized heat on the component will be dispersed along the film in all directions (isotropic) which enhances the transmission of the heat from the component to the heat sink. The diamond films may be rigid, inflexible and fragile. In order to manipulate these films the film must have a thickness of at least a few hundred microns. However, these films result from a slow chemical vapor deposition process. The deposit process is a slow one, i.e., only about one micron/hour. In order to take advantage of the basic thin film and its high thermal conductivity, it is desirable to have a thermal interface compound that can interface the film with the component and heat sink at a very low closure force. Otherwise, the film will break at a high closure force. It is also desirable that the interface material become flowable during initial component operation and/or deformable under low closure forces but not so flowable as to migrate away from the interface area. However, the interface material should not be so viscous that it requires high closure forces for component mounting which could damage the component or any associated “heat spreader” film. Thermal resistance and closure forces are thus related. Since thermal resistance is lower when the thermal path is reduced, it is desirable that a very thin interface be formed at low closure forces. Otherwise, a large closure force may damage the component and/or intermediate film. Most electrical components cannot withstand closure forces of more than 10-20 psi. The diamond film is even more sensitive to closure forces. Known interface materials require hundreds of psi to achieve a path having a low thermal resistance. Thus, a closure force problem exists. It is noted that the ASTM test standard on thermal phase change materials is done at 438 psi, well above the maximum closure force that should be applied to an electronic component. Thus, the problem may not be a recognized one. It is desirable to have an interface material at room temperature that will change phase to a flowable state at elevated temperatures and/or deformable at low closure forces. The material should not be so viscous that it requires large closure forces to deform so as to obtain the desired component interface. The material should not migrate away from the component/heat sink under elevated temperatures or under closure forces. A very thin thermal interface at low closure forces should be created to preclude damage to the component and/or heat sink and/or any intermediate film therebetween. The thermal material need not be used with a substrate carrier. A substrate increases the distance between the electrical component and the heat sink and thus increases the thermal resistance. Thus, the material should be free standing if a carrier is not desired. Currently, pressure sensitive adhesive (PSA) strips along the edges of the thermal interface material adhere the thermal interface to the heat sink. However, these strips can only partially cover the interface material as the strips have high thermal impedance and increase the thermal path. At times these strips do not provide sufficient adhesion. Moreover, foreign matter can migrate between the PSA strips and the heat sink which increases thermal resistance. Thus, the thermal interface material should be flexible, easy to handle at room temperature and dry to the touch. It also should flow at a temperature above room temperature and deform under low closure forces. The material should adhere to the heat sink and component surfaces but be removable therefrom by heat application. Also, the interface material should be able to be stored on the heat sink for transport and subsequent use. In response thereto I have arrived at a process for selecting an interface compound that meets the above objectives as well as presents the following characteristics: 1. The interface material can be manufactured in sheet or roll form, cut to a desired shape and then placed on the heat sink for subsequent sandwiching between the electrical component and the heat sink or otherwise compressed on the heat sink for adherence upon cooling. 2. The interface material can be melted by either external heat or the heat generated by the initial component operation. 3. Upon cooling below its melt/phase change temperature, the material provides sufficient adhesion to maintain the electric component to the heat sink. Thus, mechanical fasteners, e.g., PSA strips, are not required. 4. As long as the operating temperature of the component remains below the melt/phase change temperature of the thermal interface material, the component remains firmly adhered to the heat sink. 5. The projection of external hot air onto the component will increase the thermal interface temperature so as to reduce the adhesive bond for component removal. It is therefore a general object of this invention to provide an improved compound and method of selecting the same for reducing the impedance to heat flow through a thermal joint established between an electrical component and a heat sink while providing an effective adhesive bond. Another object of this invention is to provide a compound and method, as aforesaid, which is initially liquified/deformable during initial component operation but remains in a solid state during subsequent component use. A further object of this invention is to provide a compound and method, as aforesaid, wherein the compound does not melt at a subsequent normal operating temperature of the component but can be removed upon the application of external heat at a higher temperature thereto. A more particular object of this invention is to provide a compound, as aforesaid, which is easily coated onto a substrate carrier for placement between the component and heat sink. Another object of this invention is to provide a compound and method, as aforesaid, which provides a high thermal conductivity relative to previous compounds utilizing material softeners. A further object of this invention is to provide a compound, as aforesaid, which is easy to manipulate and does not contaminate surrounding personnel and equipment. Another particular object of this invention is to provide a compound, as aforesaid, which includes a material therein so as to avoid the problems associated with material softeners. A further object of an embodiment of this invention is to provide a compound which initially adheres the electrical component to the heat sink at a low closure force. Another object of this invention is to provide a compound, as aforesaid, which deforms under low closure forces of the component to the heat sink. Still another object of this invention is to provide a compound, as aforesaid, which may be effectively utilized with “heat spreader” type films. Another particular object of this invention is to provide a compound, as aforesaid, which can be used in sheet, roll or rod form and on printed circuit boards. A further object of this invention is to provide a method of depositing a pad of compound acting as a phase change material on a heat sink. Another object of this invention is to provide a method, as aforesaid, which produces a vacuum between the rod and heat sink to constrict the deposited compound material to the cross-sectional configuration of the end of the rod. A particular object of this invention is to provide a method, as aforesaid, wherein the rod remains in stable form after repeated application. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of the irregularities of the mating surfaces of an electrical component and a heat sink; FIG. 2 is a diagrammatic view, on an enlarged scale, of a semiconductor and a heat sink with a compound coated on an intermediate carrier substrate; FIG. 3 is a diagrammatic view showing the compound, as coated on a carrier substrate, the substrate being positioned between the mating surfaces of an electrical component and heat sink; FIG. 4 illustrates first and second time/temperature curves of an electrical component in connection with using the selected thermally conductive material; and FIG. 5 is a diagrammatic view illustrating a method for depositing a pad of the compound on a heat sink. DESCRIPTION OF THE PREFERRED EMBODIMENT Turning more particularly to the drawings, FIG. 1 diagrammatically shows a surface 210 of an electrical component 200 , e.g., as a transistor, semiconductor, etc., facing a heat sink 100 surface 110 . It is understood that such surfaces 110 , 210 are not smooth, such irregularities being diagrammatically shown. Upon mating the surfaces 110 , 210 , air spaces will appear between these irregular surfaces. As air is a poor conductor of heat, it is desirable to fill these resulting voids with a heat conducting medium so as to lower the impedance of the thermal joint/path 1000 established between the component 200 and heat sink 100 . The lower the impedance of the thermal path the more efficient the conduct of heat from component 200 to heat sink 100 . FIG. 2 shows a compound carrier in the form of a flexible gasket 300 which may act as an electrical insulator between surfaces 110 , 210 . The gasket 300 may also be embedded with metallic oxide/heat conducting particles so as to enhance the heat conductivity along the thermal path 1000 . However, as the gasket 300 alone may not fill all the air spaces appearing between the irregular mating surfaces 110 , 210 , the gasket 300 can act as a substrate carrier for a compound designed to fill these resulting air spaces. I have devised a method of selecting a compound which can either be coated onto the facing surfaces of the component 200 or heat sink 100 or onto opposed surfaces of an intermediate carrier substrate 300 so as to optimally fill the resulting air spaces and present an efficient thermal joint between the component 200 and the heat sink 100 . The compound is selected so that it can be coated onto a substrate 300 and inserted between the component 200 and heat sink 100 during assembly. As the compound is initially in a solid state, it does not fill all the resulting voids between the mating surfaces 110 , 210 . Thus, during initial component 200 operation, the thermal path is an inefficient one. This inefficiency causes the component 200 to reach a temperature above its normal operating temperature as well as the melt temperature of the chosen compound. The operating component 200 will thus heat the compound to its melt temperature causing the compound to liquify or deform and fill the voids between the nominally mating surfaces 110 , 210 of the component 200 and the heat sink 100 . Once the voids are so filled an efficient thermal joint 1000 is established which enhances the conductivity along the thermal joint 1000 . In turn, more heat flows from the component 200 to the heat sink 100 such that the component temperature is reduced to its normal operating temperature. During this component cool down, the compound temperature drops below its melt temperature which returns the compound to its solid state, the previously established joint 1000 being maintained. Upon subsequent operation of the electrical component 200 the component 200 will heat only to its normal operating temperature as the previously established thermal joint 1000 conducts heat from component 200 to heat sink 100 . The compound will not liquify/deform as the normal operating temperature of the component 200 remains below the compound's melt temperature. As the compound cannot liquify, it maintains a higher thermal conductivity relative to the conductivity of its liquid state. Moreover, as the compound will not flow away from the thermal joint the joint integrity is maintained. Utilizing the above principles various compounds can be selected so as to achieve an efficient thermal joint 1000 . As a first example, a compound comprises 95 parts of a paraffin wax having a 51° C. melting point. To this paraffin I add five parts by weight a 28% ethylene/vinyl acetate copolymer hardener with a 74° C. melting point. One such copolymer is an Elvax resin available from the Dupont Company, Polymer Products Division of Wilmington, Dela. The element proportions are selected so that the resulting compound will have a melt temperature above the normal operating temperature of the component. Upon heating the compound to a temperature beyond its melt temperature, i.e., approximately 52° C., the viscosity of the compound will decrease so that a carrier 300 can be dip coated into the compound. The carrier can be a 0.002 inch thick polymer insulating material with or without heat conducting materials impregnated therein. The compound resolidifies into a thin layer about 0.001 inch thick on the opposed surfaces of the polyamide carrier 300 . When the temperature of the electrical component reaches 80° C., the compound is heated beyond its melt temperature, i.e., 52° C., so as to fill the empty spaces appearing between the heat sink 100 and component 200 surfaces. This compound action will reduce the thermal impedance of the thermal joint 1000 between the component 200 and heat sink 100 such that the component 200 will eventually return to its normal operating temperature. (The thermal impedance of this compound is approximately 0.179 C/W.) As the component must initially operate beyond the compound melt temperature so as to heat the compound to its melt temperature, it is understood that by choosing a wax and copolymer with specific melt temperatures, the melt temperature of the resulting compound can be varied and chosen according to the initial and normal operating temperatures of the component. FIG. 4 diagrammatically relates the temperatures of the component 200 to the melt temperature of the compound. As shown in FIG. 4, the first heat up curve 900 of the component 200 shows the component reaching a maximum temperature at T 1 . Upon reaching this temperature, the compound will be heated beyond its melt temperature T 2 so as to become sufficiently deformable to fill the spaces between the component surface 210 and heat sink surface 110 . Upon these spaces being filled, the thermal impedance of the path between the component and the heat sink is reduced which reduces the temperature of the component 200 to the desired component operating temperature T 3 , this temperature being below the chosen compound melt temperature T 2 . Upon a subsequent operation of the component 200 , the curve 950 shows the temperature of the component 200 reaching a maximum of T 3 , the component's normal operating temperature. As the temperature of the component 200 will not increase beyond T 3 , due to the previously established efficient thermal joint 1000 , the component temperature T 3 remains below the compound melt temperature T 2 . Thus the compound will remain in a solid state during normal operation of the component, it being understood that the compound will have a higher conductivity than when in a liquid state. Thus, a more efficient conduct of heat through thermal joint 1000 will occur as compared to the prior art in which the compound is designed to liquefy. Moreover, as the resulting compound will remain in a generally solid state at the normal operating temperatures of the component 200 and not phase into a liquid state the problems with the prior art have also been addressed, e.g., the elimination of the messy liquids and a compound flow away from the thermal joint. It is also noted that as the initial heat up curve allows the component to heat beyond its normal operating temperature, compounds having high melt temperatures can be used. Thus, compounds having high molecular weights can be used, it being understood that such compounds have a better conductivity as opposed to compounds of lower molecular weight. For example, a synthetic wax having a melt point of 100° C. and a molecular weight of approximately 1000 can be used, the wax being a type of wax known as a Fischer-Tropsch wax. The wax was coated onto a carrier 300 as above described. Upon initial operation of a semiconductor the semiconductor reached a temperature of 105° C. which melted the wax. Upon the wax establishing the thermal joint the temperature of the semiconductor fell to 82° C. The thermal conductivity of the wax at 150° C. is 0.191 W/mK while at 82° C. is 0.242 W/mK. As the compound will not reach its melt temperature during subsequent use, the thermal conductivity of the joint 1000 will be greater than if the compound is liquefied as found in the prior art. Accordingly, it is desirable to have the electrical component initially heat to a temperature considerably above its normal operating temperature so as to melt the compound. Thus, the addition of the Elvax to the wax or the use of a wax of a high molecular weight can be used which results in a material which initially presents an inefficient thermal joint. (It is noted that the compound should also be relatively hard and undeformable by the normal mounting/clamping forces utilized in mounting the component to the heat sink.) This inefficient thermal joint allows the component 200 to heat to a temperature which will melt the component so as to establish a thermal joint between the component 200 and heat sink 100 . This joint will reduce the component temperature and allow the compound to resolidify. Due to this joint 1000 presence, the component 200 will not reach a temperature to subsequently melt the compound. Thus, the integrity of joint 1000 is maintained. Moreover, the use of the Elvax hardener in the compound or use of a medium of high molecular weight solves the problems associated with the prior art. Although the above has been discussed without the use of any heat conducting particles in the compound or barrier, it is also understood that heat conducting particles may also be used which may further decrease the thermal impedance of the thermal joint/path. As above set forth, I have described an interface compound in which the heat needed for melting may be generated by the component itself. Also, it is advantageous to use externally applied heat to either initially cause a flow and/or reflow the compound interface. The application of external heat to the compound interface can be utilized as most electrical components can withstand externally applied heat above its maximum operating temperature. It is also desirable that when the component cools and the compound interface returns to a solid state that it presents an adhesive characteristics sufficient to adhere the component and heat sink thereto. It is also advantageous that the compound be deformable at low closure forces so as to assist the migration of the compound into the air spaces whether prior to or after the compound is melted. It is also advantageous to vary the compound interface formulation so that the compound interface can have various adhesion characteristics at different temperatures for use with various low closure forces. In some applications the components and the heat sink must be separated by an electrically insulating medium. In other applications it is not required and in these cases a thermally conductive compound can also be electrically conductive. To achieve these characteristics I have discovered one compound which comprises 25 parts of paraffin wax having a melting point of 51° C. To this paraffin I add six parts by weight of 28% ethylene/vinyl acetate copolymer having a melt temperature of approximately 74° C. Such copolymer is an Elvax resin available from the DuPont Company. To this mixture 69 parts by weight of zinc oxide heat conducting particles may be added. These ingredients are mixed together. These proportions are found to provide a compound having a melt temperature of about 57° C. as well as provide the following values: A thermoplastic material with sufficient cohesiveness which can be laminated, molded, die-cut and physically handled during normal installation without disintegrating. A thermoplastic material which can firmly hold electric components to heat sinks. The adhesive bond between the components and the aluminum heat sink is about 25 psi. A thermoplastic material which is easily deformed under low closure forces on electronic components to form a very thin interface, the closure forces being below a fracture force damaging the component. A thermoplastic material which will not migrate away from the interface area during closure forces and subsequent component operation. I have simultaneously achieved the above characteristics with the last above-described formulation. It is noted that the reduction of the wax from the first described example from 95 parts to 25 parts along with an increase of the copolymer from five to six parts, increases the adhesion characteristic of the compound. My invention is, however, not to be limited to the above-described example as the materials of various melt temperature and proportions can be used to vary the compound melt temperature depending on the operating temperature of the component to be used thereon. The melt temperature in the latter example approaches that of the wax (51° C.) as the proportion of wax is greater than the co-polymer. (Formulas for computing a compound melt temperature based on the melt temperatures of the compound parts are known.) For example: MT =( MT 1 ×% M 1 )+( MT 2 ×% M 2 ) where MT=compound melt temperature MT 1 =material 1 melt temperature MT 2 =material 2 melt temperature Thus, various modifications may be made by choosing different characteristics, e.g., the melt points for the paraffin and the acetate copolymer. For example, if the wax and copolymer components had the same 74° C. melt temperature, the compound will have a 74° C. melt temperature. The adhesion will be about 25 psi up to this 74° C. melt temperature. If, however, the melt temperature of the paraffin is considerably higher (100° C.) than the copolymer, the adhesiveness of the compound would begin to diminish from about 25 psi at 74° C. to almost 0 psi at 100° C. as the adhesive quality decreases after the copolymer melt temperature is reached. Although an increase in the copolymer parts will increase the adhesion characteristics, this increase must be balanced against the increase in viscosity and stickiness of the compound. Also any increase in the wax percentage in the compound must be balanced against the increase in fluidity of the resulting compound. It is also understood that particles which are electrically conductive can be utilized. The use of electrically conductive metal particles rather than the electrically insulating metal oxide particles can enhance the heat transfer through the interface material. As such, I have used very small size metallic silver particles instead of the zinc oxide particles in the above example. The same volume as the volume of zinc oxide was used. In both examples, the above features were obtained. As an example of use, a compound interface similar to the one above described (25 parts wax/six parts copolymer) was screen printed via a stencil of appropriate thickness onto a preheated aluminum heat sink to present a 0.005 inch pad. The heat sink was preheated to a temperature above the reflow/melt temperature of the compound. When the heat sink cooled to room temperature the thermal pad was firmly adhered to the heat sink surface. The above compound interface can also be extruded in bulk, e.g., to form rods of material having various cross sections, e.g., various square, round, etc. shapes. The rod is pressed against a heat sink preheated above the compound melt temperature. This contact and removal of the rod deposits a pad of the thermal material thereon. The electric component is then pressed against the thermal pad which further flows the thermal material. Upon cooling, a very low thermal resistance of the thermal interface occurs between the heat sink and component with a bead 240 of the compound interface formed around the exterior of the component at its juncture with the heat sink. The compound interface firmly adheres the heat sink to the component. The above interface may be first applied to the heat sink for later connection of the component thereto upon heating the heat sink and interface material to the melt temperature with external heat or using the heat of component operation. The interface may be utilized with hot melt glue equipment as well as in computer controlled syringes for deposit on the desired heat sink surface and/or component surface. This resulting bead precludes dirt from entering the thermal interface. Another example is that the compound interface can be screen printed onto circuit boards 900 . The soldering paste can then be screen printed onto the board. A clamping device then clamps the components to the circuit board with the compound interface therebetween. The closure force provided by the clamping device may initially cause deformation to the underlying compound to cause an initial compound migration/flow. The board can then be placed in a soldering oven which simultaneously solders the components and causes the compound interface to flow creating the desired thermal interface. The above compound may also be utilized with computer controlled syringes or with melt glue equipment to deposit the compound interface on the desired surface. I have also invented a method for efficiently depositing a pad of the compound interface on a heat sink which can be utilized with various types of interface materials. Thermal interface materials, e.g., the above-identified materials, may be formed into sheets or rolls of material which are then die-cut and supplied on sheets or rolls. This method requires significant labor. If due-cut, the interface material must be first manufactured according to a desired configuration and then manually installed which includes the following operations: (1) The interface material must be between two release liners; (2) The interface material with release liners must then be die cut to the desired configuration; (3) The release liners must be removed prior to installation; (4) The material must then be installed on the heat sink. Expensive equipment must be used to dispense the phase change material on the heat sink. This equipment requires frequent clean up and maintenance, and is not easily adaptable to modification. Dispensers, which pre-melt the phase change material inside the dispenser, for subsequent “painting” of the material onto the heat sink surface are also known. The present invention provides a method which uses a preselected material formulation that remains form stable even after repeated applications. As such the material allows a simple method allowing simple equipment to be used, i.e., a simple vertically reciprocative arm to apply the material to preheated heat sink passing thereunder. The above-described phase material can be any material as long as it is highly thixotropic, e.g., a wax-based thermoplastic (not thermosetting) so that it can readily melt and resolidify. This phase change material is extruded, molded or otherwise formed into a rod having a desired cross-section corresponding to the configuration of the heat sink. The rod 1100 can then be manually depressed onto the heat sink 1200 and be installed into a vertically reciprocative arm 1300 , the arm being either manually controlled or computer controlled in a timed up and down movement. The heat sink 1200 to which the pad of thermal interface material may be preheated by any convenient method, e.g., heat lamp, hot plate, conveyor oven 1600 , etc. The heat sink should be heated to a temperature above the phase change temperature of the selected material of the above thermal compound rod but should not exceed the maximum operating temperature of this thermal interface material. For a material with a 52° C. phase change temperature, the minimum heat sink 1200 temperature should be about 60° C. so as to ensure that the heat sink 1200 is adequately heated to melt the thermal material. (Most wax containing materials should not be heated above about 200° C. so this would be the maximum heat sink temperature.) The exact temperature is not critical. Once the heat sink 1200 is heated, the rod 1100 is simply depressed vertically against the heat sink 1200 for a few seconds, then removed. The viscoelastic properties of most phase change thermal materials causes the tip of the rod 1100 to deform when melted and pressed against a heated surface. Normally, repeated application of a rod tip to heated surfaces makes the tip become progressively larger and deformed. However, in the present invention the thixotropic and viscoelastic properties of the thermal material are chosen to prevent the melted material at the rod tip from flowing beyond the dimensions of the rod. Such material will create a vacuum between the molten tip and the heated heat sink 1200 surface. The thermal material is chosen to have a highly thixotropic characteristic such that the molten material of the rod tip will not flow laterally under its own weight. Thus, when the rod is pressed against the heated heat sink surface the phase change material at the tip of the rod melts. The weight of the material causes a deposit on the heat sink as a vacuum has been formed between the rod tip and heat sink 1200 . However, as soon as the molten material tries to flow beyond the edges of the tip of the rod, the air pressure about the outside of the rod precludes the thixotropic material from flowing therebeyond. Thus, the molten material is constricted to the perimeter of the cross section of the rod. As such, removal of the rod tip from the heat sink helps to retain the shape and size of the rod tip for subsequent application. Because of these preselected properties of the thermal compound, repeated applications to the heat sink does not deform the rod tip and produces essentially the same size and thickness of a deposited thermal pad with each application. Thus, an entire rod can be used with the final deposited thermal pad on the heat sink being substantially the same as the first deposited pad. Upon movement of the rod away from the heat sink 1200 , a pad of molten, thermoplastic, thermal material, corresponding to the cross section of the rod end is deposited on the heat sink. Due to the combination of the air pressure, vacuum and thixotropic characteristic of the material, the rod material will not drip, migrate or leave a “peak” of material vertically projecting from the deposited thermal pad. After deposit, two alternative courses of action may follow: 1) The heat sink is allowed to cool, shipped and stored for later installation of the electronic component on the heat sink. In this case heat from component operation will again reflow the thermoplastic thermal material and create a very thin, low thermal resistance thermal interface assuming the above-identified material is utilized. 2) While the thermal material is still molten, the electronic component may be pressed against the molten thermal material such that the material forms a very thin thermal interface between the heat sink and component. When the heat sink cools below the phase change temperature of the thermal compound, the thermal interface material, as above described, solidifies and firmly adheres the component to the heat sink. The assembly can now be shipped or stored without worry about the shelf life or thermal degradation due to deterioration of a pressure sensitive adhesive on the thermal pad surface. These thermal material rods can be used manually or in simple, automatic equipment which holds the rods vertically and bring the rods down onto the conveyed heated heat sink surface to achieve increased repeatability of position, force and dwell time of the rod on the heat sink. Thus, the same rod can be used for manual application as well as high-speed volume production. EXAMPLES OF THE MATERIAL A thermal compound is formed by mixing: 4.25 parts by weight of Paraffin Wax having a melt point of 52° C. 1 part by weight of Ethylene-Vinyl Acetate Copolymer (Elvax) having a melt temperature of 71° C. 11.5 parts by weight of finely divided Zinc Oxide powder In some cases a surface-active agent may be used as known to those skilled in the art. The amount of heating conducting particles can be varied over a considerable range. The amount of ZnO used in such formulations should be sufficient to make the viscosity of the material high enough that the material will not migrate or flow in typical electronics interface applications. The viscosity of the resulting compound, when in the molten state is approximately 80 to 100 poises. After thorough mixing the resulting thixotropic, highly viscous thermal material was formed into rods of material using an extruder. Rods 0.5×0.5″×8″ long were produced to create thermal pads as above described. The shape and size of the thermal pads produced by the rod was substantially the same at the end of the rod as at the beginning. The data below shows the typical operating parameters for use of the rods, i.e., a heat sink temperature of 65° C.; pressure on rod of five to 10 psi and a dwell time of one second resulting in a pad thickness of 0.003″. The temperature can vary considerably without great variation in the pad that is created on the heat sink. For example, utilizing the same material in connection with a heat sink temperature of 75° C.; a pressure on rod of five to 10 psi and a dwell time of one second resulted in a pad thickness of 0.003″. Accordingly, variations in the heat sink temperature may not have a significant effect on the resulting pad thickness. Testing can be easily accomplished to find a maximum heat sink temperature which does not affect the deposit. Accordingly, it is understood that various compound materials may be used with my method as long as the selection of the compound is guided by the above-desired characteristics. Once chosen tests can be conducted as to temperature, dwell time and viscosity to assure that an undesirable migration of the rod material does not occur beyond the perimeter of the rod cross section. Other objects and advantages of the above embodiments will become apparent from the above description taken in connection with the accompanying drawings. It is to be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto, except in so far as such limitations are included in the following claims and equivalents thereof.

A method for depositing a thermal interface onto a heat sink including the selection of a highly thixotropic compound formed into a bulk form so as to present a tip which is melted upon contact with a preheated heat sink. The tip cross section preferably corresponds to the cross section of the heat sink. Upon depressing a tip of the compound against the heat sink a resulting vacuum therebetween cooperates with the ambient air pressure to preclude migration of the melted compound beyond the exterior of the tip such that the compound is deposited on the heat sink in the desired cross section form. Upon displacement of the tip from the heat sink, the ambient air pressure precludes subsequent migration of the compound onto the heat sink precluding a build up of the deposited material thereon. The component may then be subsequently pressed against the subsequent heat sink without a deformation of the compound tip precluding a subsequent deposit. Alternatively, after cooling the heat sink with pad may be reheated to melt the thermal pad for subsequent placement of a component thereon.

CROSS REFERENCE TO RELATED APPLICATION This application claims priority from Japanese Patent Application No. 2010-230585 filed Oct. 13, 2010. The entire content of the priority application is incorporated herein by reference. TECHNICAL FIELD The invention relates to an image processor provided with correcting means for correcting image data based on a correction table. BACKGROUND Many conventional printing devices for printing images on paper or other printing media using colorants, such as toner or ink, execute a calibration process for maintaining uniform printing densities, and color balance. In the calibration process, the printing device forms density patches at a plurality of density levels with the colorant used for printing, measures the densities of these patches, and updates a correction table for correcting image data based on the measured densities. By executing this calibration process at appropriate times for updating the correction table and correcting image data based on the updated correction table, the printing device can maintain consistent quality in printed images, even when the performance of the printing device changes over time. One such conventional printing device that performs this calibration process is configured to restrain toner consumption when the device is getting low on toner by either lengthening the interval between scheduled calibration processes or skipping the process entirely. SUMMARY Normally, printing devices that print images with colorant are designed to estimate the number of pages that can be printed with the amount of unused colorant remaining Naturally, it is desirable that this estimated number of printable pages does not differ greatly from the actual number of printable pages. It is particularly desirable that the actual number of printable pages be not greatly less than the estimated number of printable pages. The estimated number of printable pages is determined by estimating the quantity of colorant used for printing one sheet of the printing media. However, this estimated quantity is determined based on a default correction table created before the calibration process is executed. If the quantity of colorant used for printing one sheet of the printing media increases in the correction table when the table is updated through the calibration process, there is a high likelihood that the printing device will run out of colorant before the actual number of printable pages reaches the estimated number of printable pages. In addition, since this conventional printing device restricts execution of the calibration process when the amount of residual toner is low, aspects of printing quality such as printing density and color balance worsen. Moreover, since this conventional printing device does not account for the originally predicted number of printable pages, the device restricts execution of the calibration process when the quantity of toner runs low, even when the actual number of printable pages is greater than the estimated number. In view of the foregoing, it is an object of the invention to provide an art capable of preventing the problem of colorant running out before the actual number of printable pages reaches the estimated number of printable pages. In order to attain the above and other objects, the invention provides an image processing device includes a processing unit and a memory. The memory has instructions stored thereon that, when executed by the processing unit, cause the processing unit to function as an acquiring part, a color conversion part, a correction part, an update part, an amount determining part, and a modifying part. The acquiring part acquires image data indicating an image and having an input value. The image data is printed by using at least one color material. The color conversion part converts the input value to an output value by using a color profile that correlates the input value to the output value. The output value specifies an amount of a color material of the at least one color material. The correction part corrects the output value to a corrected value by using a correction table that correlates the output value to the corrected value. The update part updates the correction table based on a density patch formed by using the at least one color material. The amount determining part determines for each color material of the at least one color material whether a first amount is greater than a second amount. The first amount is an estimated amount of the each color material to be consumed when corrected image data corrected by using the updated correction table is printed. The second amount is an estimated amount of the each color material to be consumed when corrected image data corrected by using an initial correction table that is not updated is printed. When the amount determining part determines that the first amount is greater than the second amount for one color material of the at least one color material, the modifying part modifies the color profile such that the output value in the modified color profile specifies a less amount of color material corresponding to the one color material than an amount of color material specified by the output value in the unmodified color profile corresponding to the one color material. According to another aspect, the invention provides a non-transitory computer readable storage medium storing a set of program instructions installed on and executed by a computer. The program instructions includes acquiring image data indicating an image and having an input value where the image data is printed by using at least one color material, converting the input value to an output value by using a color profile that correlates the input value to the output value where the output value specifies an amount of a color material of the at least one color material, correcting the output value to a corrected value by using a correction table that correlates the output value to the corrected value, updating the correction table based on a density patch formed by using the at least one color material, determining for each color material of the at least one color material whether a first amount is greater than a second amount where the first amount is an estimated amount of the each color material to be consumed when corrected image data corrected by using the updated correction table is printed, and where the second amount is an estimated amount of the each color material to be consumed when corrected image data corrected by using an initial correction table that is not updated is printed, modifying the color profile, when the determining determines that the first amount is greater than the second amount for one color material of the at least one color material, such that the output value in the modified color profile specifies a less amount of color material corresponding to the one color material than an amount of color material specified by the output value in the unmodified color profile corresponding to the one color material. BRIEF DESCRIPTION OF THE DRAWINGS The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which: FIG. 1 is a block diagram showing a general structure of a printing system according to a first embodiment; FIG. 2( a ) is an explanatory diagram illustrating a binary image data generation process according to the first embodiment; FIG. 2( b ) is an explanatory diagram illustrating a calibration process and a color profile adjustment process according to the first embodiment; FIG. 2( c ) is an explanatory diagram illustrating a binary image data generation process according to a second embodiment; FIG. 3( a ) is an explanatory diagram illustrating input values in a color profile; FIG. 3( b ) is an explanatory diagram illustrating output values in the color profile corresponding to input values shown in FIG. 3( a ) before the color profile is modified; FIG. 3( c ) is an explanatory diagram illustrating corrected values obtained by correcting output values shown in FIG. 3( b ) according to a default correction table; FIG. 3( d ) is an explanatory diagram illustrating corrected values obtained by correcting output values shown in FIG. 3( b ) according to an updated correction table; FIG. 3( e ) is an explanatory diagram illustrating differences obtained by subtracting values in FIG. 3( c ) form values in FIG. 3( d ); FIG. 3( f ) is an explanatory diagram illustrating output values in a modified color profile corresponding to input values shown in FIG. 3( a ); FIG. 3( g ) is an explanatory diagram illustrating corrected values obtained by correcting output values shown in FIG. 3( f ) according to the updated correction table; FIG. 3( h ) is an explanatory diagram illustrating differences obtained by subtracting values in FIG. 3( c ) from values in FIG. 3( g ); FIG. 4 is a graph showing a relation between the input color values and the output color values in the color profile; FIG. 5( a ) is a flowchart illustrating the calibration process according to the first embodiment; FIG. 5( b ) is a flowchart illustrating a color profile adjustment process according to the first embodiment; FIG. 6 is a flowchart illustrating an active profile setting process according to the first embodiment; FIG. 7( a ) is an explanatory diagram illustrating an image to be printed; FIG. 7( b ) is a conceptual diagram showing an active profile setting region; FIG. 8 is a flowchart illustrating the binary image data generation process according to the first embodiment; FIG. 9 is a flowchart illustrating the binary image data generation process according to the second embodiment; and FIG. 10 is a flowchart illustrating an excessive toner usage calculation process according to the second embodiment. DETAILED DESCRIPTION 1. First Embodiment 1-1. Overall Structure of a Printing System FIG. 1 is a block diagram showing the general structure of a printing system configured of a personal computer 1 and a printer 2 that are capable of communicating with each other. The personal computer 1 is a general-purpose data processor and includes a control unit 11 , a communication unit 12 , an operating unit 13 , a display unit 14 , and a storage unit 15 . The control unit 11 performs overall control of the components in the personal computer 1 . The control unit 11 includes a CPU 111 , a ROM 112 , and a RAM 113 . The communication unit 12 is an interface enabling the personal computer 1 to communicate and exchange data with the printer 2 . The operating unit 13 is an input device enabling the user to input commands through external operations. In the embodiment, the operating unit 13 includes a keyboard and pointing device, such as a mouse or touchpad. The display unit 14 is an output device for displaying various information to the user as images that the user can interpret. In the embodiment, the display unit 14 is configured of a liquid crystal display. The storage unit 15 is a nonvolatile storage device storing data that can be overwritten. In the embodiment, the storage unit 15 is configured of a hard disk drive. Various software programs are installed on the storage unit 15 , including an operating system (OS) 151 , an application program 152 such as a graphics tool, and a printer driver 153 that enables the personal computer 1 to use the printer 2 . The printer 2 is an electrophotographic printing device and includes a control unit 21 , a communication unit 22 , an operating unit 23 , a display unit 24 , a storage unit 25 , an image-forming unit 26 , and a density sensor 27 . The control unit 21 performs overall control of the components in the printer 2 . The control unit 21 includes a CPU 211 , a ROM 212 , and a RAM 213 . The communication unit 22 is an interface that enables the printer 2 to communicate and exchange data with the personal computer 1 . The operating unit 23 is an input device enabling the user to input commands through external operations. The operating unit 23 includes various operating buttons. The display unit 24 is an output device for displaying various information to the user as images that the user can interpret. The display unit 24 includes a small liquid crystal display. The storage unit 25 is a nonvolatile storage device for storing data that can be overwritten. In the embodiment, the storage unit 25 is configured of flash memory. The image-forming unit 26 is a component for forming images expressed in binary image data as visible images according to an electrophotographic method that uses toner in the four colors cyan (C), magenta (M), yellow (Y), and black (K). The image-forming unit 26 includes four photosensitive members corresponding to the four toner colors. During image formation in the image-forming unit 26 , chargers apply an electric charge to the surfaces of the photosensitive members, and exposure devices such as LED heads irradiate light onto the charged surfaces of the photosensitive members to form electrostatic latent images thereon based on binary image data for each of the CMYK colors that altogether represent a color image. The electrostatic latent images formed on the photosensitive members are developed into visible toner images by toner in the CMYK colors supplied from developing devices. The toner images in each of the CMYK colors are transferred onto a sheet of paper or other recording medium conveyed by a conveying belt so as to be superposed on each other. Subsequently, the toner images are fixed to the printing medium by heat in a fixing unit, thereby completing the process of printing an image on the printing medium. The components used for this printing process are well known in the art and, therefore, have been omitted from the drawings. When a calibration process described later is executed, the image-forming unit 26 also forms density patches directly on the conveying belt with the toner used for printing. The density patches represent a plurality of density levels for each of the CMYK colors. The image-forming unit 26 is also provided with a cleaning member for recovering the density patches formed on the conveying belt after the calibration process. The density sensor 27 is used for measuring the densities of the density patches formed by the image-forming unit 26 on the conveying belt. The CPU 21 estimates the number of sheets that can be printed with the amount of unused toner based on the predetermined quantity of toner for printing one sheet printed by using the default correction table. 1-2. Process Overview Next, an overview of processes executed on the above printing system will be described. The printer driver 153 is started when the user of the personal computer 1 initiates a print operation in the application program 152 while the application program 152 is executing. As a process of the application program 152 , the printer driver 153 passes image data representing an image to be printed to the control unit 11 of the personal computer 1 , and the control unit 11 converts the image data to binary image data for the CMYK colors so that the data can be rendered on the printer 2 , and transfers the converted binary image data to the printer 2 . Here, the image data represents the image and specifies the pixel values. The image data passed from the application program 152 is configured of draw commands. These draw commands can be classified as bitmap draw commands for drawing photo objects (hereinafter referred to as “photo draw commands”), text draw commands for drawing text objects, and graphics draw commands for drawing graphics objects. Therefore, in the personal computer 1 according to the embodiment, the control unit 11 first develops the image data configured of draw commands into image data expressed in 256-level RGB values. Next, as indicated in FIG. 2( a ), the control unit 11 performs a color conversion process on the RGB image data for converting this image data into data expressed in CMYK values based on a color profile that specifies correlations between the input color values (RGB values) and the output color values (CMYK values). Note that the color profile according to the embodiment refers to a device link profile linking the device profile of the display unit 14 (an ICC profile) to the device profile of the printer 2 (an ICC profile). FIG. 3( a ) shows an example of input color values for the color profile. In this example, the input color values range from white (RGB=255, 255, 255) to blue (RGB=0, 0, 255) and from blue to black (RGB=0, 0, 0). FIG. 3( b ) is an example of output color values in the color profile. Here, the output color values correspond to the input color values in FIG. 3( a ). For example, the output color values (CMYK values) for blue corresponding to the input color values for blue (RGB=0, 0, 255) are CMYK=237, 83, 0, 0. As shown in the graph of FIG. 4 , the color progression arrives at blue with a density of 100% just before the Y and K components are added. In the following description, the “dark region” refers to the range of densities greater than blue at 100% (primary blue), while the “light region” refers to the density range from 0 to 50% blue. The range of colors between 50 and 100% blue will be referred to as the “intermediate region”. The personal computer 1 according to the embodiment is provided with three different color profiles for various types of objects (photos, text, and graphics). Specifically, a photo color profile is provided for photo objects, a text color profile for text objects, and a graphics color profile for graphics objects. After undergoing the color conversion process, the image data is then subjected to a correction process based on a correction table, as shown in FIG. 2( a ). The correction table in the embodiment is a look-up table specifying correlations between input values configured of CMYK values, and output values configured of corrected CMYK values (denoted as C′M′Y′K′ values in FIG. 2( a ) to distinguish them from the input values). Therefore, the corrected image data is also expressed in 256-level CMYK values. Following the correction process, the image data is further subjected to a thresholding process using the dither method to generate binary image data for each of the CMYK colors. The personal computer 1 then transmits this binary image data to the printer 2 , and the printer 2 prints the image represented by this binary image data. A correction table to be used in the correction process is created when the calibration process is performed. However, prior to performing the calibration process, a default correction table is used. In other words, the correction table used in the correction process is updated each time the calibration process is performed. In the embodiment, the control unit 11 compares the correction table newly created in each calibration process (hereinafter referred to as the “updated correction table”) to the default correction table and determines whether the quantity of toner usage in the updated correction table is greater than that in the default correction table for each color of toner, as shown in FIG. 2( b ). When the control unit 11 of the personal computer 1 determines that the quantity of toner usage in the updated correction table has increased from that in the default correction table for toner of one or more colors, the control unit 11 of the personal computer 1 adjusts one or more color profiles to reduce the output values for colors whose toner usage has increased. 1-3. Detailed Description of the Processes Next, the calibration process executed by the control unit 11 of the personal computer 1 (and more specifically the CPU 111 of the control unit 11 ) will be described with reference to the flowchart in FIG. 5( a ). The control unit 11 executes the calibration process as a function of the printer driver 153 in response to a user request. In S 101 at the beginning of the calibration process, the control unit 11 instructs the printer 2 to measure the densities of density patches. Accordingly, the printer 2 directly forms density patches on the conveying belt with toner used for printing and measures the densities of the density patches with the density sensor 27 . Here, the density patches represent a plurality of density levels for each of the CMYK colors. In S 102 the control unit 11 receives measured densities for the density patches from the printer 2 . In S 103 the control unit 11 creates a new correction table (updated correction table) based on the measured densities and subsequently ends the calibration process. The new correction table is created such that the printer 2 can maintain consistent quality in printed imaged even when the performance of the printer 2 changes over time. Next, a color profile adjustment process executed by the control unit 11 of the personal computer 1 (and more specifically the CPU 111 of the control unit 11 ) will be described with reference to the flowchart in FIG. 5( b ). The control unit 11 executes this color profile adjustment process after the calibration process described in FIG. 5( a ). In S 201 at the beginning of the color profile adjustment process, the control unit 11 compares the updated correction table to the default correction table, and in S 202 determines for each color of toner whether the toner usage in the updated correction table is higher (greater in density) than that in the default correction table. Specifically, the control unit 11 compares the sum of the correction values (output values) for all input values in the updated correction table to the sum of the correction values (output values) for all input values in the default correction table for each color of toner, and determines that toner usage in the updated correction table has increased over that in the default correction table when there exists at least one color for which the sum of correction values in the updated correction table is greater than the sum of correction values in the default correction table. If the control unit 11 determines in S 202 that toner usage in the updated correction table has increased over that in the default correction table, then in S 203 the control unit 11 calculates the amount of increase (difference) in toner usage for colors whose sum of correction values in the updated correction table exceeds the sum of correction values in the default correction table. This difference may be calculated, for example, as the sum of differences obtained by subtracting values resulting from performing the correction process on output values in the color profile according to the default correction table from values produced in the correction process on these output values in the color profile according to the updated correction table. FIG. 3( c ) shows the values produced in a correction process on the output color values in FIG. 3( b ) using the default correction table, while FIG. 3( d ) shows the values obtained from the correction process performed on the output color values in FIG. 3( b ) according to the updated correction table. FIG. 3( e ) shows the differences obtained by subtracting the values in FIG. 3( c ) from the values in FIG. 3( d ). In this example, the sum of differences for the CMYK colors is found to be 64, 64, 28, and 22, respectively. In S 204 the control unit 11 newly creates a modified photo color profile based on the original photo color profile by adjusting the output color values in the dark region of the original photo color profile so that the sum of output color values in the modified photo color profile for each color is equal to a value obtained by subtracting the sum of the differences for that color calculated in S 203 from the sum of the output values in the original photo color profile for that color. FIG. 3( f ) shows the modified output color values obtained by reducing the output color values overall in the dark region so that the sum of output color values for each of the CMYK colors in the modified photo color profile is equal to a value obtained by subtracting the sum of the differences for that color shown in FIG. 3( e ) from the sum of the output values for that color shown in FIG. 3( b ). FIG. 3( g ) shows the values obtained by performing a correction process on the output color values in FIG. 3( f ) according to the updated correction table. FIG. 3( h ) shows the differences obtained by subtracting the values in FIG. 3( c ) from the values in FIG. 3( g ). Here, the sum of the differences is “0” for each of the CMYK colors. In other words, the increase in the CMYK values in the updated correction table is canceled by reducing the output color values in the color profile. In the embodiment, the output color values in the dark region for each color shown in FIG. 3( g ) is obtained by subtracting a constant value (“4” for C′ values, for example) from the output color values in the dark region shown in FIG. 3( d ). In S 205 the control unit 11 creates a modified text color profile based on the original text color profile by adjusting output color values in regions other than the light region of the text color profile (the region of densities greater than 50%; i.e., the intermediate region and the dark region) so that the sum of output color values for each color in the modified text color profile is equal to a value obtained by subtracting the sum of the differences for that color calculated in S 203 from the sum of output color values for that color in the original text color profile. The details of this process are essentially the same as the process described in S 204 for the photo color profile, except that output color values in the intermediate region are modified (reduced) in addition to the dark region. Note that the output color values in the light region depicting text are not modified because reducing the output color values in this region could make the light text so light as to be illegible. In S 206 the control unit 11 creates a modified graphics color profile based on the original graphics color profile by adjusting all output color values in the graphics color profile so that the sum of output color values for each color in the modified graphics color profile is equal to a value obtained by subtracting the sum of the difference for that color calculated in S 203 from the sum of output color values for that color in the original graphics color profile. The details of the process to adjust the graphics color profile are similar to those for the photo color profile described in S 204 , except that the control unit 11 adjusts all output color values in the graphics color profile. Subsequently, the control unit 11 ends the color profile adjustment process. However, if the control unit 11 determines in S 202 that toner usage in the updated correction table has not increased over that in the default correction table (S 202 : NO), the control unit 11 ends the color profile adjustment process without adjusting color profiles. Next, an active profile setting process executed by the control unit 11 of the personal computer 1 (and specifically the CPU 111 of the control unit 11 ) will be described with reference to the flowchart in FIG. 6 . The control unit 11 executes the active profile setting process as a function of the printer driver 153 when the user has initiated a print operation for printing image represented by the image data in the application program 152 . In S 301 at the beginning of the active profile setting process, the personal computer 1 initializes an active profile setting region. The active profile setting region is an area of the RAM 113 allocated for storing profile flags indicating the type of color profile to be used in a color conversion process (hereinafter referred to as the “active profile”) for each pixel in the image to be printed. Specifically, in S 301 the control unit 11 initializes the profile flags to “0” for all pixels in the active profile setting region. In subsequent processes (S 305 and S 308 ), the control unit 11 sets profiles flags to “1” for pixels whose active profile is the photo color profile, and “2” whose active profile is the text color profile. The profile flag is left unchanged at “0” for pixels whose active profile is the graphics color profile. FIG. 7( a ) shows a sample image to be printed. As shown in FIG. 7( a ), the image includes a photo object A 1 , text objects A 2 , and graphics objects A 3 . FIG. 7( b ) is a conceptual drawing showing the active profile setting region storing profile flags for the image in FIG. 7( a ). In FIG. 7( b ), each pixel in a region B 0 depicted in white has been initialized to “0”, each pixel in a region B 1 has the profile flag “1” indicating a photo color profile, and each pixel in regions B 2 depicted in black has been set to the profile flag “2” indicating a text color profile. Returning to FIG. 6 , in S 302 the control unit 11 acquires one draw command that has not yet been subjected to one of the draw processes in S 304 , S 307 , and S 309 described below. The draw command is acquired from all draw commands constituting the image data representing the image to be printed and set as the process target. That is, each draw command corresponds to one object. When objects in the image to be printed are arranged in overlapping positions, the control unit 11 acquires draw commands in overlapping positions in order with the command for the topmost object being last. Consequently, the active profile for areas with overlapping objects is set based on the draw command of the topmost object at each overlapping position. In S 303 the control unit 11 determines whether the draw command acquired in S 302 as the process target is a bitmap draw command (photo draw command). That is, the control unit 11 determines whether the object of the process target is the bitmap. If the control unit 11 determines that the process target is a bitmap draw command (S 303 : YES), in S 304 the control unit 11 executes the draw process based on the draw command. Through this process, the process target is developed into 256-level RGB data representing the photo object. In S 305 the control unit 11 sets the profile flag to “1” indicating the photo color profile for all pixels in the active profile setting region that correspond to the drawing region for the RGB data generated in S 304 . In other words, the control unit 11 sets the active profile for all pixels constituting the photo object developed in S 304 to the photo color profile. Subsequently, the control unit 11 advances to S 310 . However, if the control unit 11 determines in S 303 that the process target is not a bitmap draw command (S 303 : NO), in S 306 the control unit 11 determines whether the process target is a text draw command. That is, the control unit 11 determines whether object of the process target is text. If the control unit 11 determines that the process target is a text draw command (S 306 : YES), in S 307 the control unit 11 executes a draw process based on the process target. That is, if the process target is graphics draw command (i.e. the object of the process target is the graphics), the profile flags is left unchanged at “0”. Through this draw process, the process target is developed into 256-level RGB data representing the text object. In S 308 the control unit 11 sets the profile flag to “2” indicating the text color profile for all pixels in the active profile setting region that correspond to the drawing region for the RGB data generated in S 307 . In other words, the active profile for all pixels constituting the text object developed in S 307 is set to the text color profile. Subsequently, the control unit 11 advances to S 310 . However, if the control unit 11 determines in S 306 that the process target is not a text draw command (i.e., that the process target is a graphics draw command; S 306 : NO), in S 309 the control unit 11 executes a draw process based on the process target. Through this draw process, the process target is developed into 256-level RGB data representing a graphics object. Subsequently, the control unit 11 advances to S 310 . In S 310 the control unit 11 determines whether the draw process has been executed for all draw commands in the image data representing the image to be printed. The control unit 11 returns to S 302 upon determining that there remain draw commands for which the draw process has not yet been executed (S 310 : NO) and ends the active profile setting process upon determining that the draw process has been executed for all draw commands (S 310 : YES). Next, a binary image data generation process executed by the control unit 11 of the personal computer 1 (and more specifically, the CPU 111 of the control unit 11 ) will be described with reference to the flowchart in FIG. 8 . The control unit 11 executes the binary image data generation process after completing the active profile setting process in FIG. 6 as a function of the printer driver 153 . In S 401 at the beginning of the binary image data generation process, the control unit 11 acquires pixel data (256-level RGB values) for one pixel that has yet to be subjected to a thresholding process described later (S 409 ) from the pixels in the image to be printed. In S 402 the control unit 11 acquires the active profile from the active profile setting region that has been set for the pixel data acquired in S 401 . In S 403 the control unit 11 determines whether the active profile acquired in S 402 is the photo color profile. When the control unit 11 determines that the active profile is the photo color profile (S 403 : YES), in S 404 the control unit 11 executes the color conversion process using the photo color profile. If the control unit 11 creates the modified photo color profile in the color profile adjustment process shown in FIG. 5( b ), the control unit executes the color conversion process using the modified photo color profile. If the modified photo color profile was not created, the control unit 11 uses the original photo color profile. Subsequently, the control unit 11 advances to S 408 described below. However, if the control unit 11 determines that the active profile is not the photo color profile (S 403 : NO), in S 405 the control unit 11 determines whether the active profile acquired in S 402 is the text color profile. If the control unit 11 determines that the active profile is the text color profile (S 405 : YES), in S 406 the control unit 11 executes the color conversion process using the text color profile. If the control unit 11 creates the modified text color profile in the color profile adjustment process shown in FIG. 5( b ), the control unit executes the color conversion process using the modified text color profile. If the modified text color profile was not created, the control unit 11 uses the original text color profile. Subsequently, the control unit 11 advances to S 408 described below. However, if the control unit 11 determines that the active profile is not the text color profile (i.e., that the active profile is the graphics color profile; S 405 : NO), in S 407 the control unit 11 executes the color conversion process using the graphics color profile. If the control unit 11 creates the modified graphics color profile in the color profile adjustment process shown in FIG. 5( b ), the control unit executes the color conversion process using the modified graphics color profile. If the modified photo color profile was not created, the control unit 11 uses the original graphics color profile. Subsequently, the control unit 11 advances to S 408 . In S 408 the control unit 11 performs the correction process to correct the CMYK values produced from the color conversion process based on the correction table. In S 409 the control unit 11 executes the thresholding process for converting the 256-level CMYK values produced from the correction process into binary values (2-level values). In S 410 the control unit 11 determines whether the thresholding process has been executed for all pixels in the image to be printed. The control unit 11 returns to S 401 upon determining that there remain pixels that have not been subjected to the thresholding process (S 410 : NO) and ends the binary image data generation process upon determining that all pixels have been subjected to the thresholding process (S 410 : YES). 1-4. Effects of the Embodiment According to the first embodiment described above, the personal computer 1 can reduce the levels of toner used through the color conversion process by adjusting the color profiles so as to reduce output color values when the toner usage in the updated correction table is greater than that in the default correction table. As a result, the personal computer 1 can neutralize the increase in toner usage so that the printer 2 is less likely to run out of toner before the actual number of printed sheets reaches the number of printable sheets estimated based on the default correction table. By adjusting the photo color profile to reduce output color values in the dark region in particular, the personal computer 1 can reduce toner usage without a likely drop in the quality of printed photo objects. Color balance and gradation levels are extremely important for photo objects, and changes in toner usage in light and intermediate regions can upset the CMYK color balance. However, since the dark region contains near-black colors, reducing output color values in the dark region does not dramatically change the color tones, despite there being a slight shift in the color balance. Further, the personal computer 1 according to the embodiment adjusts the text color profile to reduce output color values in regions other than the light region. Accordingly, the personal computer 1 can reduce the quantity of toner usage while preventing light text from becoming so light as to be illegible. Further, the personal computer 1 according to the embodiment adjusts the graphics color profile to reduce all output color values. Hence, the personal computer 1 can prevent a drop in quality in the printed images. In addition, by making an overall determination as to whether the toner usage in the updated correction table is greater than that in the default correction table without regard for the image being printed, the personal computer 1 can reduce the process load required for this determination. 2. Second Embodiment 2-1. Differences from the First Embodiment Next, a second embodiment of the invention will be described. The second embodiment has the same basic configuration as the first embodiment, but differs in the following points. (1) The personal computer 1 according to the second embodiment determines whether toner usage in the updated correction table has increased over toner usage in the default correction table by comparing the sums of CMYK values for all pixels obtained when correcting the image data representing the image to be printed based on the default correction table to the sums of CMYK values for all pixels obtained when correcting the image data based on the updated correction table for each of the toner colors. In other words, the personal computer 1 determines whether toner usage in the updated correction table is greater than that in the default correction table based on the image to be printed. (2) The personal computer 1 according to the second embodiment calculates the differences obtained by subtracting the sum of CMYK values for all pixels obtained when correcting the image data based on the updated correction table from the sum of CMYK values for all pixels obtained when correcting the image data based on the default correction table for each of the toner colors. These differences are accumulated for each color of toner as the total surplus (as described later in S 513 ) each time the image is printed. (3) The personal computer 1 according to the second embodiment determines whether the quantity of toner usage in the updated correction table has increased over the quantity of toner usage in the default correction table for one or more colors. When this amount of increase, which is the amount of excessive usage, exceeds the total surplus calculated above, the personal computer 1 adjusts the color profile to reduce the output color values (CMYK values) for the colors whose toner usage has increased. Specifically, as shown in FIG. 2( c ), the personal computer 1 according to the second embodiment calculates the total surplus of toner based on image data produced in the correction process. If the excessive usage is less than or equal to the total surplus, the personal computer 1 does not adjust the color profile, even though the toner usage in the updated correction table is greater than that in the default correction table. Hence, rather than performing the color profile adjustment process in FIG. 5( b ), the active profile setting process in FIG. 6 , and the binary image data generation process in FIG. 8 described in the first embodiment, the personal computer 1 according to the second embodiment performs a binary image data generation process shown in FIG. 9 and an excessive toner usage calculation process shown in FIG. 10 . The remaining configuration of the second embodiment is identical to that in the first embodiment and will not be described below. 2-2. Detailed Description of the Processes Next, the binary image data generation process executed by the control unit 11 of the personal computer 1 (and more specifically, the CPU 111 of the control unit 11 ) will be described with reference to the flowchart in FIG. 9 . The control unit 11 executes the binary image data generation process as a function of the printer driver 153 in response to a print operation for printing the represented by the image data initiated by the user. The binary image data generation process is performed after the control unit 11 executes a draw process for image data including draw commands in the drawing region. In S 501 at the beginning of the binary image data generation process, the control unit 11 executes the color conversion process using a normal color profile. In S 502 the control unit 11 executes an excessive toner usage calculation process. FIG. 10 is a flowchart illustrating steps in the excessive toner usage calculation process. In S 601 of the process in FIG. 10 , the control unit 11 corrects the CMYK image data according to the default correction table. In S 602 the control unit 11 corrects the CMYK image data based on the current correction table. The “current correction table” is the default correction table before the calibration process has been executed once and is the updated correction table after the calibration process has been executed once. In S 603 the control unit 11 sets a target toner color X to cyan (C). Here, X is a variable representing one of the colors C, M, Y, and K. In the following description, X will be treated as the color set as the process target. In S 604 the control unit 11 sets a target pixel (i.e., a pixel to be processed) to the first pixel in the image (the pixel in the upper left, for example). In S 605 the control unit 11 compares the value of X toner in the image data created in S 601 (hereinafter referred to as the “default correction value”) to the value of X toner in the image data created in S 602 (hereinafter referred to as the “current correction value”) for the target pixel and calculates the difference between the two values (i.e., current correction value—default correction value). In S 606 the control unit 11 updates the excessive usage of X toner by adding the difference calculated in S 605 to the quantity of excessive usage for X toner accumulated thus far and temporarily stored in the RAM 113 . Hence, the control unit 11 adds up the difference calculated for each target pixel in order to find the sum of differences for all pixels in the image, and sets this sum as the excessive usage. The control unit 11 updates the excessive usage in the RAM 113 such that the excessive usage indicates this sum. In S 607 the control unit 11 determines whether the target pixel is the last pixel in the image (the pixel on the bottom right, for example). If the control unit 11 determines that the target pixel is not the last pixel of the image (S 607 : NO), in S 608 the control unit 11 sets the target pixel to the next pixel after the current target pixel, and subsequently returns to S 605 . However, if the control unit 11 determines that the target pixel is the last pixel (S 607 : YES), in S 609 the control unit 11 determines whether the toner color X currently being processed is black (K). If the control unit 11 determines that the toner color X is not black (S 609 : NO), in S 610 the control unit 11 changes the toner color set as X to another color. Specifically, if the toner color X is currently cyan, the control unit 11 changes the process target to magenta. If the toner color X is currently magenta, the control unit 11 changes the process target to yellow. If the toner color X is currently yellow, the control unit 11 changes the process target to black. Subsequently, the control unit 11 returns to S 604 . However, if the control unit 11 determines in S 609 that the process target of the toner color X is black (i.e., that all of the CMYK colors have been processed; S 609 : YES), the control unit 11 ends the excessive toner usage calculation process. Through the excessive toner usage calculation process described above, the control unit 11 calculates excessive toner usage (amount of increase in toner usage) for each of the CMYK colors. In S 606 the difference (current correction value—default correction value) for the target pixel is added to the excessive usage for each toner color X. After the control unit 11 finishes the excessive toner usage calculation process that repeats S 605 and S 606 shown in FIG. 10 , the excessive usage for each color indicates a difference of a sum of the current correction value for all pixels and a sum of the default correction value for all pixels for each of CMYK colors. Returning to the flowchart in FIG. 9 , in S 503 the control unit 11 sets the toner color X to the process target cyan. In S 504 the control unit 11 resets the X toner correction amount to “0”. In S 505 the control unit 11 determines whether the excessive usage of X toner calculated in S 502 is greater than “0”. In other words, the control unit 11 determines whether the amount of toner usage in the current correction table has increased over that in the default correction table. When the control unit 11 determines in S 505 that the excessive usage of X toner is greater than “0” (S 505 : YES), in S 506 the control unit 11 determines whether the excessive usage of X toner is greater than the total surplus of X toner. If the control unit 11 determines that the excessive usage of X toner is greater than the total surplus of X toner (S 506 : YES), in S 507 the control unit 11 finds the X toner correction quantity by subtracting the total surplus of X toner from the excessive usage of X toner. In other words, the control unit 11 sets the correction quantity to the portion of the excessive usage not counterbalanced by the total surplus. Subsequently, the control unit 11 advances to S 508 . However, if the control unit 11 determines in S 505 that the excessive usage of X toner is less than or equal to “0” (S 505 ; NO) or if the control unit 11 determines in S 506 that the excessive usage of X toner is less than or equal to the total surplus of X toner (S 506 : NO), then the control unit 11 advances directly to S 508 while leaving the correction quantity for X toner at “0”. In S 508 the control unit 11 determines whether the current process target of the toner color X is black. If the toner color X is not black (S 508 : NO), in S 509 the control unit 11 changes the process target for the toner color X. That is, if the toner color X is currently cyan, the control unit 11 changes the process target to magenta. If the toner color X is currently magenta, the control unit 11 changes the process target to yellow. If the toner color X is currently yellow, the control unit 11 changes the process target to black. Subsequently, the control unit 11 returns to S 504 . However, if the control unit 11 determines in S 505 that the process target of toner color X is black (i.e., that the above process has been performed for all CMYK colors; S 508 : YES), in S 510 the control unit 11 determines whether the toner correction quantity is no greater than “0” for all four CMYK colors. If the control unit 11 determines that one or more toner colors have a correction quantity greater than “0” (S 510 : NO), in S 511 the control unit 11 creates a color profile that reduces the toner usage for each color by the toner correction quantity of the corresponding color. The same method described in the first embodiment may be used to correct the color profile. For example, the control unit 11 may adjust all output color values so that the sum of output color values for each color is reduced an amount equivalent to the toner correction quantity. As described in the first embodiment, the control unit 11 may perform separate processes based on the type of object. In S 512 the control unit 11 performs the color conversion process using the new color profile created in S 511 . Subsequently, the control unit 11 returns to S 502 and repeats the process described above from S 502 using the adjusted color profile. However, if the control unit 11 determines in S 510 that the toner correction quantity for each of the four CMYK colors is “0” or less (S 510 : YES), in S 513 the control unit 11 updates the total surplus by subtracting the excessive usage from the current total surplus for toner in each of the CMYK colors. Note that the total surplus is increased when the excessive usage is smaller than “0”. The excessive usage for each color indicated the difference of the sum of the current correction value for all pixels and the sum of the default correction value for all pixels. Thus, the total surplus indicates the accumulation of the negative value of the excessive usage. The total surplus resets to a prescribed initial value when a new toner (a toner cartridge (not shown), for example) is mounted. In S 514 the control unit 11 executes a thresholding process for converting image data produced in the correction process based on the current correction table in S 602 to binary values. Subsequently, the control unit 11 ends the binary image data generation process. 2-3. Effects of the Second Embodiment As described above, the personal computer 1 according to the second embodiment can make a relatively more accurate determination regarding whether toner usage in the updated correction table has increased over that in the default correction table since the personal computer 1 makes this determination for each printing operation using the image data representing the image being printed. Moreover, the personal computer 1 according to the second embodiment does not adjust the color profile unless the excessive usage of toner has exceeded the total surplus, even when the toner usage in the updated correction table has increased over that in the default correction table. Hence, this method prevents the personal computer 1 from unnecessarily restricting toner usage when extra toner was left over from a previous printing operation. 3. Variations of the Embodiments While the invention has been described in detail with reference to specific embodiments thereof, it would be apparent to those skilled in the art that many modifications and variations may be made therein without departing from the scope of the invention, the scope of which is defined by the attached claims. (A) The personal computer 1 according to the first embodiment described above uses a photo color profile for photo objects, a text color profile for text objects, and a graphics color profile for graphics objects, but the invention is not limited to this configuration. For example, the personal computer 1 may share the same color profile for both text and graphics objects so that overall output color values in text objects are also adjusted, as with the graphics color profile. (B) In the embodiments described above, the printer 2 forms density patches on the conveying belt used for conveying the printing media. However, if the printer 2 is configured to transfer toner images temporarily from the photosensitive members to an intermediate transfer belt and subsequently to transfer the full color image from the intermediate transfer belt to the printing medium, the printer 2 may form the density patches on the intermediate transfer belt. Alternatively, the printer 2 may form density patches on the printing medium. (C) Although toner is used as an example of colorant (color material) in the embodiments, the colorant of the invention is not limited to toner, but may instead be ink, for example. (D) While the process according to the invention is performed by the personal computer 1 in the embodiments, this process may be performed on the printer 2 side instead, for example.

In the image processing device, the color conversion part converts the input value to an output value by using a color profile. The correction part corrects the output value to a corrected value by using a correction table. The update part updates the correction table based on a density patch. The first and second amount is an estimated amount of the color material to be consumed when corrected image data corrected by either using the updated correction table or using an initial correction table, respectively, is printed. When the amount determining part determines that the first amount is greater than the second amount, the modifying part modifies the color profile such that the output value in the modified color profile specifies a less amount of color material than an amount of color material specified by the output value in the unmodified color profile.

This is a continuation of application Ser. No. 07/252,801, filed Sep. 30, 1988, now abandoned. FIELD OF THE INVENTION The present invention relates to oxynitride frontside microstructures, and to their fabrication. BACKGROUND OF THE INVENTION The application of silicon-based electronics systems, especially for automotive applications, has seen an almost explosive growth in the last few years. The silicon-based electronics are used to store control algorithms, process information, and to direct actuators to perform various functions, including steering, suspension, and display of driver information, to name but a few. While the electronics revolution unfolds, sensor technology, on the other hand, is not keeping pace, and sensor designs continue to be based on dated technologies with inbred limitations. Recent trends have identified silicon as the basis for future sensor technology, and this hopefully will close this technology gap and permit greater application of control systems utilizing sensor technology. Existing control systems use silicon-based electronics, and nearly all have embedded microprocessors. Silicon is widely recognized in the industry as being suitable for this application in view of its high reliability, high strength and low cost. In addition, silicon sensor designs can be created using a variety of manufacturing processes, one of the most promising of which is referred to as "micromachining" which uses chemical processes to introduce three-dimensional mechanical structures into silicon. These "microstructures", as they are referred to, can be made sensitive to specific physical phenomena, such as acceleration, pressure or fluid flow, by taking advantage of several special properties of silicon, including piezo resistance, piezo electric and controlled resistance. For example, a micromachined cantilevered beam produces a minute resistance change when flexed by the force of acceleration. However, the output signal from this micromachined sensor is very small (millivolts), so that additional electronic circuitry is necessary for signal conditioning and amplification. These electronic circuits are usually integrated circuit chips which are interconnected to the micromachined element. Different aspects of micromachining are reviewed in Lee et al, "Silicon Micromachining Technology For Automotive Applications", SAE Publication No. SP 655, February 1986, and the entire content of that publication is hereby incorporated by reference. A disadvantage associated with polycrystalline silicon is that it possesses an inherent high compressive stress. For example, undoped polycrystalline silicon has a stress of the order of -5×10 9 dyne/cm 2 . This high compressive stress is a disadvantage especially when polysilicon is used for the fabrication of free-standing microstructures, such as cantilevers or bridges, which must be mechanically stable and must not buckle or break. Such structures must have a low level of stress in order to produce free-standing stable structures of sufficient dimension to be useful as a sensing element. In a typical polysilicon deposition process used widely in the fabrication of integrated circuits today, silane gas is injected into a process tube at low pressure and a temperature of approximately 625° C. These processing conditions produce a very uniform layer of deposited polysilicon material on a substrate. However, the polysilicon layer and the underlying substrate will produce a net compressive stress force in the polysilicon and this gives rise to the disadvantages noted earlier. Recently, there has been much research into methods for producing stress-free polycrystalline silicon. These methods have primarily been to deposit the silicon at a temperature that will produce an amorphous silicon film having little or no crystalline structure present. There have been other attempts to anneal the polysilicon in different ways to relieve the stress. All of the prior methods suffer from the disadvantage of changing the polysilicon deposition parameters and utilizing high temperatures (i.e. above 600° C.) and are incompatible with current technology trends and processing methods. In particular, the use of high temperatures for annealing and other processing is precluded if pre-existing electronic circuitry is present. SUMMARY OF THE INVENTION It has now been found that it is possible to fabricate devices such as microsensors at relatively low temperatures by creating an oxynitride microstructure on a suitable semiconductor substrate. Thus, according to one aspect of the present invention; there is provided a method of producing a microstructure comprising forming an oxynitride microstructure on the surface of a silicon substrate. According to another aspect of the present invention, there is provided a method of forming an integrated silicon sensor comprising forming an oxynitride microstructure on a major surface of a substrate having at least one integrated circuit provided on that major surface, under conditions which do not adversely affect the integrated circuit. According to a yet further aspect of the present invention, there is provided a device comprising a semiconductor substrate and an oxynitride microstructure disposed on a major surface of the substrate. It will be appreciated that by fabricating the oxynitride microstructure at relatively low temperatures, typically not higher than 500° C., and preferably within the range of about 80° to 450° C., it is possible to fabricate sensors and other components on a prefabricated integrated circuit without destroying or otherwise harming the electronics. The method of the present invention thus facilitates exploitation of the so-called "foundry" concept in which integrated circuit processing is first carried out on a silicon wafer and this is followed, at a later stage, by fabrication of integrated sensor microstructures on vacant real estate of the wafer. By fabricating the sensor microstructures at temperatures less than 500° C., and preferably less than 400° C., it is possible to introduce a large number of sensors having different architecture without damaging the electronic circuitry already present on the wafer. A further advantage realized according to the present invention is that the fabrication of the microstructures can be controlled so as to produce a low stress oxynitride. Typically, the stress of the oxynitride of the microstructures of the present invention is less than about 5×10 8 dynes/cm 2 , and may be in the range of 5×10 6 to 5×10 8 dynes/cm 2 , which enables the formation of stable and flexible oxynitride bridges and cantilevers. The material ordinarily used for fabrication of microstructures is polysilicon but, as indicated earlier, polysilicon suffers from an inherent compressive stress, and requires deposition temperatures in excess of 550° C., usually in the region of 625° to 650° C. This inherent compressive stress associated with polysilicon makes that material somewhat unsuitable for the fabrication of sensors which rely on a bridge or cantilever-type configuration. The stress of the oxynitride microstructure can be carefully controlled by adjusting the ingredients used to form the oxynitride, typically silane, nitrous oxide and nitrogen. As a result of the stability and flexibility of the oxynitride microstructures of the present invention, it is possible to fabricate free-standing microstructures suitable for use as, for example, accelerometers, pressure sensors and mass air flow sensors, such as anemometers. Other sensing functions are also within the purview of the microstructures of the present invention, such as, for example, in the automobile industry for detecting fuel flow rate, valve position and cylinder pressure. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, in which: FIGS. 1 through 6 show schematically the principal method steps of the present invention; FIG. 7 shows a side view of an integrated silicon sensor comprising an integrated circuit and a cantilever oxynitride microstructure; FIG. 8 shows an enlarged cross-sectional view of embodiments of the cantilever of FIG. 7. DETAILED DESCRIPTION OF THE INVENTION It will be understood that, for purposes of simplicity and ease of description and understanding, the invention will now be described with respect to the formation of an oxynitride microstructure of an uncomplicated type. It will be appreciated, however, that in a typical arrangement, there may be one or more integrated circuit components and one or more microstructures formed on the same side of the silicon substrate. In addition, since oxynitride is an insulator, the sensor comprising oxynitride is adapted for measurement of the sensed phenomenon, such as fluid flow rate, pressure or acceleration, utilizing capacitive, piezo electric or piezo resistive techniques. This is discussed below in connection with FIGS. 7 and 8. Referring to FIGS. 1 through 6, there is shown a silicon substrate 2, typically in the form of a wafer, on which there is formed a spacer layer 4. The spacer layer may be a metal layer such as an aluminum layer formed by sputtering aluminum at elevated temperatures, typically about 200° C., using conventional sputtering technology. Alternatively, the spacer layer 4 may be an oxide layer, for example a layer of silicon dioxide formed by oxidizing the silicon substrate 2 at an elevated temperature, for example 950° to 1100° C., typically 1000° to 1050° C., for a period of about 3 to 6 hours, usually about 4 hours, in the presence of steam. The process in which the silicon dioxide layer is formed is conventional, and well known to a person of ordinary skill in this art. The resulting spacer layer 4 is generally about 1 to 2 microns thick. The spacer layer 4 is then etched using conventional photolithography techniques to produce an etched spacer layer. In this step, the spacer layer is coated with an emulsion 6 of a standard photoresist material, and subjected to ultraviolet light through a mask 8 to define a desired pattern in the photoresist material, as shown in FIG. 2. The exposed photoresist material is then developed and etched using conventional techniques to produce an etched spacer layer as shown in FIG. 3. It can be clearly seen in FIG. 3 that the etched layer 4 has windows 10 extending through to the silicon substrate 2. An oxynitride layer 12 is then deposited on the etched spacer layer 4 to produce the structure shown in FIG. 4. The oxynitride is deposited utilizing plasma-enhanced chemical vapor deposition (PECVD) to produce an oxynitride layer having a thickness of, for example, between 1000 and 25000 Angstroms, such as 7000 to 8000 Angstroms. The oxynitride layer is formed from a mixture of silane (silicon tetrahydride), nitrous oxide and nitrogen. The relative proportions of silane, nitrous oxide and nitrogen are carefully chosen so as to ensure that the resulting oxynitride layer is of low stress, i.e. less than 5×10 8 dyne/cm 2 . It has been found that this can be achieved by adjusting the relative amounts of silane, nitrous oxide and nitrogen so that the volume ratio between those constituents is 0.5 to 2 (silane):3 to 12 (nitrous oxide):5 to 20 (nitrogen), preferably about 1 (silane):6 (nitrous oxide):10 (nitrogen). The stress of the microstructures of the present invention is measured by techniques known to persons of ordinary skill in this art. In particular, the method described by Guckel et al, "A Simple Technique for the Determination of Mechanical Strain in Thin Films with Application to Polysilicon", J. App. Phys., 1671, 1985 may be used to measure the strain in the silicidated microstrucure. The stress is then calculated from a knowledge of known mathematical techniques. An alternative method for measuring the stress is to use a stress guage, such as the one manufactured by Ionic Systems Inc. under the model number 30122. Such a guage measures the average stress across the wafer. The deposition of the oxynitride layer is carried out at a temperature of not more than 500° C., and is preferably in the region of 150° to 300° C. The deposition is effected under reduced pressure, typically in the region of about 200 to 400 microtorr (mtorr), preferably about 300 mtorr. Ordinarily, the deposition is carried for a period of about 20 to 40 minutes, depending on the desired thickness of oxynitride layer, and at a power level of about 40 to 60 watts. It has been found, according to a preferred embodiment, that an oxynitride layer having a thickness of about 7200 Angstroms can be obtained by depositing oxynitride under conditions of plasma-enhanced chemical vapor deposition using silane, nitrous oxide and nitrogen in a volume ratio of about 1:6:10 at a pressure of about 300 mtorr, a temperature of about 300° C., over a time period of about 20 minutes at a power level of 45 watts. Following deposition, the oxynitride layer 12 is then subjected to etching using conventional photoresist techniques. This produces an etched oxynitride layer 12 as shown in FIG. 5. FIG. 6 shows the result of etching the spacer layer (or sacrificial layer) 4 to give a low stress free-standing microstructure 14. As will be seen from FIG. 6, the microstructure 14 can possess cantilever portions 16 or bridge portions 18 which are stable and do not buckle or break in view of the absence of tensile or compressive stress in the oxynitride material. As noted earlier, the stress of the oxynitride layer is less than 5×10 8 dyne/cm 2 , and preferably less than 1×10 8 dyne/cm 2 . A particularly preferred aspect of the present invention is illustrated in FIG. 7. In that Figure, there is shown an oxynitride microstructure 20 formed on the frontside 22 of the silicon substrate 2 in close proximity to the integrated circuit 24. The fabrication of such frontside microstructures is made possible by the fact that the present invention is carried out at temperatures not higher than 500° C., and preferably less than 400° C. so that adjacent integrated circuit electronics are not subjected to heat damage. A further important advantage associated with this approach is that all of the processing and manipulation of the wafer is effected on one side of the silicon substrate (i.e. the frontside), thereby obviating the need to effect processing manipulation on both sides of the wafer, such as is required when using conventional back-etch techniques. The overall strength of the integrated sensor is thereby increased, and the overall cost of production is reduced. FIG. 8 shows a cantilever of the invention adapted for measuring acceleration as reflected by flexing of the cantilever terminal portion 26. In the embodiment shown in FIG. 8, the cantilever 20 has a metal layer 30 sandwiched between two layers of oxynitride 32, 34. Such a structure may be fabricated using conventional deposition techniques, e.g. sputtering or evaporation, discussed earlier. The metal may be selected from aluminum, platinum, nickel, titanium, tungsten, gold, chromium, silver, palladium, titanium-tungsten, titanium-platinum, aluminum-silicon, aluminum-silicon-copper. The preferred metal layer is aluminum. The layer can be present as a thin layer, for example not more than 1000 Angstroms thick. While the preferred structure shown in FIG. 8 contains three layers, it is possible to use two layers or more than three layers. Whichever arrangement is employed, it is important to encapsulate the metal layer (as shown in FIG. 8), especially when the layer is aluminum, to minimise corrosion and wear. In the FIG. 8 embodiment, the capacitive change is being measured as a result of flexing of the cantilever 20 with respect to the substrate 2. Alternatively, however, it is possible to measure the movement of the cantilever by use of a piezoelectric or piezoresistive element such as that shown at 36. The element is disposed on a highly stressed part of the cantilever structure 20 and detects movement of the free end of the cantilever. Any suitable piezoelectric material, for example zinc oxide, or piezoresistive material, for example silicon, may be used. The invention will now be further described with reference to the following Example. EXAMPLE Three silicon wafers having an aluminum film formed on the surface thereof were prepared using conventional electron (E)-beam techniques at 200° C. The thickness of the aluminum film in each instance was about 2 microns. An emulsion of standard photoresist material was then applied to the aluminum film of each of the three wafers, and each were exposed to ultraviolet light through a standard contact mask. Each wafer was then developed and subjected to etching using standard procedures to etch the aluminum film down to the silicon in accordance with the pattern of the mask. The three wafers thus formed were then treated as follows: Sample 1 A nitride film was deposited on the wafer using plasma-enhanced chemical vapor deposition under the following conditions: SiH 4 --19% (11 sccm) NH 3 --10% (7.2 sccm) N 2 --18% (189 sccm) The PECVD was carried out at 300° C. for 35 minutes at a power level of 57 watts and a pressure of 400 mtorr. This resulted in a nitride layer having a thickness of about 8000 Angstroms. Sample 2 A nitride layer was deposited on the wafer using PECVD under the following conditions: SiH 4 --17% (8.5 sccm) NH 3 --55% (41.25 sccm) N 2 --10% (100 sccm) The PECVD was carried out at 350° C. for 34 minutes at a power level of 57 watts and a pressure of 350 mtorr. This resulted in a nitride layer having a thickness of about 7300 Angstroms. Sample 3 An oxynitride layer was deposited on the wafer under the following conditions: SiH 4 --20% (10 sccm) N 2 O--80% (60.0 sccm) N 2 --10% (100 sccm) The PECVD was carried out at a temperature of 300° C. for 23 minutes at a power level of 45 watts and a pressure of 300 mtorr. This resulted in a oxynitride layer having a thickness of about 7200 Angstroms. Each wafer was then subjected to photolithography using conventional techniques followed by reactive ion etching (RIE) with a nitride etch, using a power level of 60 watts (20%) under a pressure of 90 mtorr with a CF 4 /O 2 mixture introduced at a flow rate of 16 sccm (40%). The etch time was about 10 to 20 minutes. Finally, a sacrificial layer etch was carried out using potassium hydroxide or "pirahana" (a hydrogen peroxide/sulphuric acid mixture) to remove remaining aluminum and produce a free-standing microstructure. Samples 1 and 2 (with the nitride layers) collapsed due to high stress present in the nitride layer. Sample 3, on the other hand, resulted in a stable, low stress oxynitride free-standing structure which did not collapse or buckle, as evidenced by scanning electron microscope (SEM) photography.

Method for producing a low stress silicon oxynitride microstructure on a semiconductor substrate at temperatures not higher than 500° C. The method is particularly adapted for forming integrated silicon sensors where the oxynitride microstructure is fabricated on a substrate under conditions which do not harm the integrated circuit electronics.

The present invention relates to a process for preparing 5′-acetylstavudine, an intermediate which is useful in the preparation of 2′,3′-didehydro-3′-deoxythymidine, an active principle with antiviral action which is commonly known as stavudine (D4T). TECHNICAL FIELD OF THE INVENTION Many processes for preparing stavudine have been described in the literature, such as, for example, those reported in: EP-A-0 340 778, EP-A-0 493 602, EP-A-0 501 511, WO 92/09599, EP-A-0 334 368, EP-A-0 519 464, EP-A-0 653 435, EP-A-0 653 436, EP-A-0 735 044, in Mansuri et al., J. Org. Chem. 1989, 54, 4780-4785 and in Classon et al., Acta Chem. Scand., B36, 1982, 251. Among these, EP-A-0 334 368, Mansuri et al. and Classon et al. describe the preparation of stavudine by deacetylation of 5′-acetylstavudine; in greater detail, both EP-A-0 334 368 and Mansuri et al. describe a process for preparing 5′-acetylstavudine (B) by reductive elimination of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine (A) in the presence of zinc as reducing agent and copper as activating agent, according to the reaction scheme given below. 5′-Acetylstavudine is then converted into the final product by hydrolysis with sodium methoxide in methanol. The synthetic scheme described in Classon et al. is substantially identical, the only difference being that the reductive elimination reaction is carried out in the presence of zinc as reducing agent and acetic acid as activating agent. However, the two synthetic processes described above are relatively unsatisfactory, in particular on account of the reductive elimination reaction which gives only moderate yields and, thus, is difficult to apply at the industrial level; the purpose of the present invention is thus to find a process which allows the reductive elimination of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine in yields greater than those of the processes known in the art. DESCRIPTION OF THE INVENTION A process has now been found, and this constitutes the subject of the present invention, which makes it possible to prepare 5′-acetylstavudine in yields that are substantially greater than those of the processes described above; according to this process, 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine is converted into 5′-acetylstavudine by reductive elimination in the presence of zinc as reducing agent combined with an ammonium salt or a phosphonium salt as activating agent. Among the various ammonium salts, the ones that are particularly preferred are the halides and sulphates; among the halides, those that are most indicated for carrying out the invention are selected from tributylamine hydrochloride, triethylamine hydrochloride, ammonium chloride, tributylamine hydrobromide, triethylamine hydrobromide and/or ammonium bromide. Among the phosphonium salts, the ones that are preferred are the halides, in particular the bromides, for example such as triphenylphosphine hydrobromide. As will be seen from the examples which follow, and which should be considered as purely illustrative of and non-limiting on the invention, zinc is generally used in an amount of between 1 and 4 equivalents and preferably between 1.5 and 2.4 equivalents, while the ammonium salt is used in an amount of between 0.2 and 2 equivalents and preferably between 0.5 and 1.5 equivalents. The process according to the present invention may be carried out in the usual organic solvents used in reductive eliminations, such as alcohols, ethers, esters or dipolar aprotic solvents; among these, the preferred solvents are dipolar aprotic solvents such as, for example, DMF or DMSO and ethereal solvents such as, for example, THF, or mixtures thereof. In the preferred embodiment of the invention, 1.5-2.4 equivalents of zinc powder are added to a solution at 20° C. of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine in DMF, DMSO or THF, or mixtures thereof. The reaction mixture is left stirring for about 10 minutes and 0.5-1.5 equivalents of the ammonium salt, preferably tributylamine hydrochloride, triethylamine hydrochloride, ammonium chloride, tributylamine hydrobromide, triethylamine hydrobromide or ammonium bromide, are then added; the system is then left to react at 30° C. for about 2 hours, until the reaction is complete. As may be appreciated from the examples attached, the process according to the present invention allows the production of 5′-acetylstavudine in particularly high yields when compared those of processes known in the prior art; specifically, 5′-acetyl-10 stavudine may be obtained in yields of 56-67% working with 86-90 g of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine and in yields of greater than 70% by working with about 10 g of starting material; in contrast, the processes described in EP-A-0 334 368, Mansuri et al. and Classon et al. give yields of 44-52% by working using substantially smaller starting amounts of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine, that is to say more or less of the order of 1.6-2 g. The 5′-acetylstavudine obtained according to the process of the present invention may then be converted into stavudine according to the various processes known in the art, such as, for example, those disclosed in EP-A-0 334 368, Mansuri et al. and Classon et al., which should thus be considered as included in the present description also as regards the preparation of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine. EXAMPLE 1 Zinc powder (352 g) is added to a solution of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyl-uridine (90.8 g) in DMF (998 ml) at 20° C. The reaction mixture is left stirring for 10 minutes. Ammonium chloride (13.1 g) is then added. An exothermic reaction takes place, the temperature rises spontaneously to 35-40° C. and the system is left to react at 30° C. The solid is filtered off and the DMF is evaporated off under vacuum at 60-65° C. to give a dense oil. This material is taken up in tetrahydrofuran (700 ml) and stirred for 2 hours. The precipitate is filtered off and washed with tetrahydrofuran (100 ml). The solution thus obtained is evaporated to dryness and the solid thus obtained is taken in isopropanol (450 ml) and heated to reflux, distilling off the head fractions up to the boiling point of the isopropanol. The mixture is cooled slowly to 20-25° C. and left stirring at this temperature for 3 hours. The solid thus obtained is filtered off and washed with isopropanol (50 ml). The wet solid thus obtained is redissolved in hot isopropanol, decolorized with charcoal, filtered, left to cool slowly and allowed to crystallize at 20-25° C. The solid is filtered off, washed with isopropanol and dried under vacuum at 60° C. to give 34.2 g of acetylstavudine (yield relative to the theoretical amount=57.3%). EXAMPLE 2 Zinc powder (20.8 g) is added to a solution of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine (86 g) in DMF (946 ml) at 20° C. The reaction mixture is left stirring for 10 minutes. Triethylamine hydrochloride (14.6 g) is then added. An exothermic reaction takes place, the temperature rises spontaneously to 35-40° C. and the system is left to react at 30° C. The solid is filtered off and the DMF is evaporated off under vacuum at 60-65° C. to give a dense oil. This material is taken up in tetrahydrofuran (700 ml) and stirred for 2 hours. The precipitate is filtered off and washed with tetrahydrofuran (100 ml). The solution thus obtained is evaporated to dryness and the solid thus obtained is redissolved in isopropanol (200 ml) and this solution is evaporated under vacuum. The residue is taken up in isopropanol (400 ml) and heated to reflux, distilling off the head fractions up to the boiling point of the isopropanol. The mixture is cooled slowly to 20-25C and left stirring at this temperature for 3 hours. The solid thus obtained is filtered off and washed with isopropanol (75 ml). The wet solid thus obtained is redissolved in hot isopropanol, decolorized with charcoal, filtered while hot, left to cool slowly and allowed to crystallize at 20-25° C. The solid is filtered off, washed with isopropanol and dried under vacuum at 60° C. to give 33.8 g of acetylstavudine (yield relative to the theoretical amount=60%). EXAMPLE 3 2′-Deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine (86 g) is dissolved in THF (1l) at 20±5° C. and zinc powder (28.8 g) is then added. The reaction mixture is left stirring for 15 minutes. Tributylamine hydrochloride (70.6 g) dissolved in THF (290 ml) is added as quickly as possible. An exothermic reaction takes place. The reaction mixture is stirred at 30° C. until the reaction is complete, and is then cooled to 20° C. and stirred for 2 hours at this temperature, after which the suspension is filtered through Celite and washed with THF (100 ml). The solution thus obtained is evaporated under vacuum at 40° C. The solid thus obtained is taken up in isopropanol (150 ml) and concentrated under vacuum at 40° C., and the operation is repeated with further isopropanol (150 ml). The residue thus obtained is taken up in isopropanol (400 ml) and heated to reflux until completely dissolved. This solution is cooled slowly to 20° C. and left stirring at this temperature for 3 hours. The solid is filtered off and washed with isopropanol (70 ml). The wet solid thus obtained is redissolved in hot isopropanol, left to cool slowly to 20-25° C. and stirred at this temperature. The solid is filtered off, washed with isopropanol (70 ml) and dried under vacuum at 50° C. to give 31.8 g of acetylstavudine (yield relative to theoretical amount=56.3%). EXAMPLE 4 Zinc powder (32.3 g) is added to a solution of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine (100 g) in THF (1.4 1) and DMSO (80 ml) at 20° C. The reaction mixture is left stirring for 10 minutes. Tributylamine hydrochloride (78.4 g) is then added. An exothermic reaction takes place, the temperature rises spontaneously to 35-40° C. and the system is left to react at 30° C. until the reaction is complete. The solid is filtered off and the THF is evaporated off under vacuum at 60-65° C. to give a dense oil. The residue thus obtained is taken up in isopropanol (2×150 ml) and this solution is evaporated under vacuum. The residue is taken up in isopropanol (465 ml) and the solution is brought to reflux. The mixture is cooled slowly to 20-25° C. and left stirring at this temperature for 3 hours. The solid thus obtained is filtered off and washed with isopropanol (100 ml). The wet solid thus obtained is redissolved in hot isopropanol, decolorized with charcoal, filtered while hot, left to cool slowly and allowed to crystallize at 20-25° C. The solid is filtered off, washed with isopropanol (100 ml) and dried under vacuum at 60° C. to give 41.0 g of acetylstavudine (yield relative to the theoretical amount=65.4%). EXAMPLE 5 Zinc powder (32.3 g) is added to a solution of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine (100 g) in THF (1.4 1) and DMSO (80 ml) at 20° C. The reaction mixture is left stirring for 10 minutes. Tributylamine hydrobromide (98.5 g) is then added. An exothermic reaction takes place, the temperature rises spontaneously to 35-40° C. and the system is left to react at 30° C. until the reaction is complete. The solid is filtered off and the THF is evaporated off under vacuum at 60-65° C. to give a dense oil. The residue thus obtained is taken up in isopropanol (2×150 ml) and this solution is evaporated under vacuum. The residue is taken up in isopropanol (465 ml) and the solution is brought to reflux. The mixture is cooled slowly to 20-25° C. and left stirring at this temperature for 3 hours. The solid thus obtained is filtered off and washed with isopropanol (100 ml). The wet solid thus obtained is redissolved in hot propanol, decolorized with charcoal, filtered while hot, left to cool slowly and allowed to crystallize at 20-25° C. for 3 hours. The solid is filtered off, washed with isopropanol (100 ml) and dried under vacuum at 60° C. to give 42.1 g of acetylstavudine (yield relative to the theoretical amount=67%). EXAMPLE 6 In order to ascertain the possible influence of the acid activator on the yield of the reductive elimination reaction of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine, the reaction in the presence of zincitriethylamine hydrochloride was compared with a similar reaction carried out in the presence of zinc/trifluoroacetic acid; the trifluoroacetic acid was used at a concentration such as to minimize the pH measured in an aqueous solution of triethylamine hydrochloride (pH 5.6±0.2) at a concentration of 5.1 g/110 ml. Reaction with triethylamine hydrochloride Zinc powder (3.2 g) is added to a solution of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-20 methyluridine (10 g ) in 110 ml of DMF at 20° C. The reaction mixture is left stirring for 10 minutes. Triethylamine hydrochloride (5.1 g) is then added. An exothermic reaction takes place and the temperature rises spontaneously to 35-40° C. This mixture is left to react at 30° C. for 3 hours. At the end of the 3 hours, the conversion of the 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine into 5′-2 5 acetylstavudine was evaluated by HPLC. HPLC analysis (percentage areas): 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine (starting material)<0.5%, acetylstavudine 78.7%. Conversion yield determined by HPLC titre=73%. Reaction with trifluoroacetic acid Zinc powder (3.2 g) is added to a solution of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine (10 g) in 110 ml of dimethylformamide at 20° C. The reaction mixture is left stirring for 10 minutes. Trifluoroacetic acid is then added (1 ml of a 0.003% solution of trifluoroacetic acid in dimethylformamide). The amount of trifluoroacetic acid is that required to reproduce the calculated pH generated by the triethylamine hydrochloride under the conditions described in the above experiment. The reaction mixture is stirred for 15 minutes, without any increase in temperature being observed. The reaction mixture is then heated to 30-35° C. for 3 hours. At the end of the 3 hours the conversion of the 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine into 5′-acetylstavudine was evaluated by HPLC, and it was found that no conversion 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine into 5′-acetylstavudine had taken place (HPLC analysis of the reaction mixture: no acetylstavudine detectable). Conclusions As may be readily observed by the comparison between the yield for the reaction carried out in the presence of zinc/triethylamine hydrochloride (73%) and that for the reaction carried out in the presence of zinc/trifluoroacetic acid (no product formed), it may reasonably be concluded that the acidity of the reaction medium does not play an important role in activating the reductive elimination reaction of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine. EXAMPLE 7 Zinc powder (3.2 g) is added to a solution of 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine (10 g) in THF (142 ml) and DMSO (8 ml) at 20° C. The reaction mixture is stirred for 10 minutes. Triphenylphosphine hydrobromide (12.1 g) is then added. An exothermic reaction takes place, the temperature rises spontaneously to 35-40° C. and the system is left to react at 30° C. until reaction is complete. At the end of the three hours, the conversion of the 2′-deoxy-2′-bromo-3′,5′-diacetyl-5-methyluridine into 5′-acetylstavudine was evaluated by HPLC. Conversion yield determined by HPLC titre=65%.

The present invention relates to a process for preparing 5′-acetylstavudine, an intermediate which is useful in the preparation of 2′,3′-didehydro-3′-deoxythymidine, an active principle with antiviral action which is commonly known as stavudine (D4T).

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for reducing noise due to head-tape contact in a single-ended magnetoresistive read element. 2. Background of the Invention Information is written onto a magnetic tape by magnetizing tape elements. These magnetized tape elements produce a magnetic field that can be detected and converted to an electrical signal by a read head. A common type of read head for carrying out this conversion is the magnetoresistive (MR) read head. A simple MR head consists of a thin film of magnetoresistive material, such as permalloy, between two insulating layers. When the MR layer is formed, a magnetic field is typically applied in a direction parallel to the plane of the thin layer. Thus, the MR layer exhibits a uniaxial anisotropy with an easy-axis of magnetization parallel to the direction of the applied field. If an external magnetic field, such as from a magnetic tape, is applied normal to the easy-axis, the magnetization direction of the MR layer will rotate away from the easy-axis and toward the direction of the applied magnetic field. This magnetization rotation causes a change in resistance in the MR layer. When no external field is applied, the resistance is greatest. The resistance decreases with increasing applied field. For practical geometries of the MR layer, resistance as a function of applied field traces a bell-shaped curve. The MR head is often biased with an applied current such that a zero magnitude applied field results in a resistance near an inflection point on the resistance curve. Thus, small changes about a zero magnitude applied external field result in nearly linear changes in resistance. To accommodate increasing densities of data stored on magnetic tape, the geometries of read heads continue to shrink. As read head geometries become smaller, however, MR read heads become increasingly susceptible to noise. Dual-element read heads may be used in a differential manner to counteract some of this susceptibility by eliminating common-mode noise, but at a cost of slightly increased head size and loss of data density on the recording medium. A need exists, therefore, for a read head that allows for a smaller physical size than conventional double-element read heads, but with less susceptibility to noise. SUMMARY OF THE INVENTION The present invention is directed toward a single-element magnetoresistive (MR) read head with reduced susceptibility to noise. In particular, the present invention addresses the problem of noise generated thermally through contact with the recording medium. The present invention solves this problem by keeping the temperature of the read head at a level that minimizes the noise level. According to a preferred embodiment of the present invention, the shielding material used in the read head is recessed with respect to the magnetic-medium-bearing surface. In an alternative embodiment of the present invention, a thin coating of metal on the read head surface is applied. In yet another embodiment, the read element is operated with a low bias current so as to minimize the thermal effect of power consumption due to electrical resistance. In still another embodiment, the read element makes use of insulating material that is both an electrical insulator and a high quality thermal insulator. BRIEF DESCRIPTION OF THE DRAWINGS The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: FIG. 1 is a diagram depicting the main components of a magnetic tape drive in which the teachings of the present invention may be applied; FIG. 2 is a diagram of a magnetoresistive read element and associated read circuitry as may be incorporated into a preferred embodiment of the present invention; FIG. 3 is a diagram of a magnetoresistive read element in which the shielding material is recessed with respect to the active surface of the read element in accordance with a preferred embodiment of the present invention; and FIG. 4 is a diagram of a magnetoresistive read element with thin metal layer in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is directed generally toward a magnetoresistive (MR) read element for reading information from a magnetic storage medium in a storage device. FIG. 1 depicts the primary components of a magnetic tape drive, which is one type of storage device in which the present invention may be implemented. Magnetic tape 108 moves from source spool 110 to take-up spool 112 in a pulley action from force applied by motor 114 . Source spool 110 and take-up spool 112 may exist separately, or may be incorporated into an integrated package, such as a tape cartridge or cassette. Data recorded to magnetic tape 108 will preferably be written in the form of several parallel tracks extending longitudinally along a surface of magnetic tape 108 . Read/write assembly 106 will preferably contain multiple read heads and write heads for reading and writing to/from these tracks simultaneously. Read/write assembly 106 maintains alignment with magnetic tape 108 by way of a servo control 124 , which uses solenoid 126 to position read/write assembly 106 vertically with respect to magnetic tape 108 . Read/write assembly 106 is generally positioned so that its read and write heads are kept at a very small distance from magnetic tape 108 in order to detect the small magnetic flux reversals on magnetic tape 108 that encode digital data or other information (e.g. analog signals or audio). Because read/write assembly 106 is positioned at only a small distance from magnetic tape 108 , which is a moving medium, intermittently the read/write assembly 106 and the read and write elements it contains will make contact with magnetic tape 108 . This intermittent contact with magnetic tape 108 causes the temperature of the read and write elements in read/write assembly 106 to fluctuate. When the read elements are very small in size, this contact with magnetic tape 108 can result in a significant amount of thermally-generated noise being injected into the signal read from magnetic tape 108 . One of ordinary skill in the art will recognize that this thermally-generated noise resulting from contact with the recording medium (hereinafter referred to as “thermal contact noise”) is not a phenomenon limited to magnetic tapes, but may also occur in other magnetic media without limitation. Examples of other magnetic media include floppy disks, hard disks, and magnetic drums. FIG. 2 is a diagram depicting a single-element magnetoresistive (MR) read element 200 as may be incorporated into a preferred embodiment of the present invention. MR read element 200 comprises a layer of magnetoresistive material 202 , such as permalloy, sandwiched between two layers of an electrically insulating material 204 to form a generally rectangular block, which is in turn sandwiched between two layers of magnetic shielding material (shields) 211 . One side of MR read element 200 that contains an exposed portion of magnetoresistive material 202 is designated as an active side 206 of MR read element 200 and is the side of MR read element 200 that faces recording medium 208 . In the presence of a magnetic field, such as that provided by recording medium 208 , magnetoresistive material 202 changes in electrical resistance. Thus, magnetoresistive material 202 acts as a variable resistor or rheostat that varies in resistance in response to changes in the local magnetic field. Thus, a signal may be read from recording medium 208 via MR read element 200 by incorporating magnetoresistive material 202 into a circuit to fulfill the role of a rheostat. In FIG. 2 , magnetoresistive material 202 is used as a variable feedback resistor in an operational amplifier (op-amp) circuit operating in an inverting configuration. A voltage source 210 is connected through a fixed resistor 212 to inverting input 216 of an op-amp 214 , while non-inverting input 218 of op-amp 214 is grounded (optionally through a resistor 220 , as shown). Magnetoresistive material 202 is connected in a feedback path from output 222 of op-amp 214 to inverting input 216 of op-amp 214 . This arrangement allows a bias current to flow through magnetoresistive material 202 and allows the resistance of magnetoresistive material to control the gain of the resulting inverting amplifier circuit provided by op-amp 214 . Thus, a magnetic signal recorded on recording medium 208 in converted by the resulting variable-gain amplifier circuit into a corresponding voltage level at output 222 . Returning attention now to the physical characteristics of MR read element 200 , it can be seen from FIG. 2 that active side 206 of MR read element 200 forms a rectangle in two dimensions. The width of each constituent component in the MR read element sandwich is the “element width” of MR read element 200 (dimension 224 ). The length of the entire MR read element 200 across the sandwich layers is called the “total shield distance” of MR read element 200 (dimension 226 ). It can be shown experimentally that thermal contact noise in an MR read element such as MR read element 200 becomes significant when element width 224 is equal to or less than total shield distance 226 , the element's operating temperature is substantially higher than the ambient temperature, and when the thermal conduction from the MR element to the media is too high. Thermal contact noise can be reduced by minimizing the temperature change of the read element by tape contact. The tape cools the element by the following process: First, the tape transfers heat from the shields, cooling them. Then, since the shields are in thermal equilibrium with the element the element will cool also. We can therefore minimize element temperature changes by either minimizing heat flow between the shields and tape, or providing a means to make the heat flow more constant. Minimizing heat flow between shields and tape can be done by A) Keeping the element temperature close to the tape temperature, thereby not heating the shields with the element and thus lowering the temperature differential between shields and tape. We accomplish this by either maintaining a bias current below a pre-determined amount, or lowering resistance below a pre-determined amount, or both. B) Thermally isolating the element from the shields, thereby not heating the shields with the element and thus lowering the temperature differential between shields and tape. We accomplish this by either using a high-quality thermal insulator for the insulating material 204 , or by increasing the thickness of this material, or both. Making the heat flow between shields and tape more constant can by done by A) Enhancing thermal contact between tape and shields with a coating on the head surface, thereby keeping heat transfer between shields and tape more constant and less susceptible to intermittent, discrete cooling events. This is depicted in FIG. 4 . B) Reducing thermal contact between the tape and shields by recessing the shields from the tape bearing surface, thereby minimizing heat transfer between the shields and tape. This is depicted in FIG. 3 . FIG. 3 is a diagram of an MR read element 300 in accordance with a preferred embodiment of the present invention. MR read element 300 contains magnetoresistive material 302 surrounded by shields 310 , separated from magnetoresistive material 302 by layers of insulating material 304 . Shields 310 are then enclosed by closure layers 315 , which are separated from shields 310 by insulating layers 313 . Closure layers 315 are, in a preferred embodiment, made from an alloy such as an aluminum-titanium-carbon (AlTiC) alloy, both other materials may be substituted without departing from the scope and spirit of the present invention. Closure layers 315 have medium-bearing surfaces 320 that make contact with magnetic medium 317 (e.g., magnetic tape or disk). Shields 310 (as well as magnetoresistive material 302 and insulating layers 304 and 313 in this example) are recessed from the plane of tape bearing surfaces 320 . This configuration avoids heat transfer between shields 310 and magnetic medium 317 , and thus reduces thermal contact noise. FIG. 4 is a diagram depicting an alternative embodiment of an MR read element 400 in accordance with a preferred embodiment of the present invention. MR read element 400 , in addition to having a layer of magnetoresistive material 402 , layers of insulative material 404 , and layers of shielding material 411 , also has a thin layer of metal applied to the active side of MR read element 400 . The metal layer allows for more even cooling of MR read element 400 and helps to stabilize the temperature of MR read element 400 to avoid noise. The metal layer in one particular embodiment consists of a 10 Angstrom layer of gold. The alternative embodiment of the present invention depicted in FIG. 4 is particularly useful in single-use or limited-use magnetic reading devices, where erosion of the metal layer over time is not a problem. As stated previously, additional alternative embodiments of the present invention reduce thermal contact noise by lowering a bias current of the magnetoresistive material or steady state resistance of the magnetoresistive material to beneath a pre-determined amount. This prevents heating of the shields by the magnetoresistive material by keeping the current density of the magnetoresistive material low and thus lowers the temperature differential between the shields and magnetic medium (e.g., tape). This can also be accomplished by using a high-quality insulating material and/or increasing the thickness of the insulating material to prevent the magnetoresistive material portion of the MR read element from heating the shields. The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

A single-element magnetoresistive (MR) read head with reduced susceptibility to noise is disclosed. In particular, the present invention addresses the problem of noise generated thermally through contact with the recording medium. The present invention solves this problem by keeping the temperature of the read head at a level that minimizes the noise level. According to a preferred embodiment of the present invention, the shielding material used in the read head is recessed with respect to the magnetic-medium-bearing surface. In an alternative embodiment of the present invention, a thin coating of metal on the read head surface is applied. In yet another embodiment, the read element is operated with a low bias current so as to minimize the thermal effect of power consumption due to electrical resistance. In still another embodiment, the read element makes use of insulating material that is both an electrical insulator and a high quality thermal insulator.

FIELD OF THE INVENTION The present invention relates generally to the field of oil and gas well drilling. More particularly, the present invention relates to a method and system for directional drilling in which the drill string is rotated back and forth between selected surface measured torque magnitudes without changing the tool face angle, thereby to reduce friction between the drill string and the well bore. BACKGROUND OF THE INVENTION It is very expensive to drill bore holes in the earth such as those made in connection with oil and gas wells. Oil and gas bearing formations are typically located thousands of feet below the surface of the earth. Accordingly, thousands of feet of rock must be drilled through in order to reach the producing formations. Additionally, many wells are drilled directionally, wherein the target formations may be spaced laterally thousands of feet from the well's surface location. Thus, in directional drilling, not only must the depth but also the lateral distance of rock must be penetrated. The cost of drilling a well is primarily time dependent. Accordingly, the faster the desired penetration location, both in terms of depth and lateral location, is achieved, the lower the cost in completing While many operations are required to drill and complete a well, perhaps the most important is the actual drilling of the bore hole. In order to achieve the optimum time of completion of a well, it is necessary to drill at the optimum rate of penetration and to drill in the minimum practical distance to the target location. Rate of penetration depends on many factors, but a primary factor is weight on bit. Directional drilling is typically performed using a bent sub mud motor drilling tool that is connected to the surface by a drill string. During sliding drilling, the drill string is not rotated; rather, the drilling fluid circulated through the drill string cause the bit of the mud motor drilling tool to rotate. The direction of drilling is determined by the azimuth or face angle of the drilling bit. Face angle information is measured downhole by a steering tool. Face angle information is typically conveyed from the steering tool to the surface using relatively low bandwidth mud pulse signaling. The driller attempts to maintain the proper face angle by applying torque or drill string angle corrections to the drill string. Several problems in directional drilling are caused by the fact that a substantial length of the drill string is in frictional contact with and supported by the borehole. Since the drill string is not rotating, it is difficult to overcome the friction. The difficulty in overcoming the friction makes it difficult for the driller to apply sufficient weight to the bit to achieve an optimal rate of penetration. The drill string exhibits stick/slip friction such that when a sufficient amount of weight is applied to overcome the friction, the drill the weight on bit tends to overshoot the optimum magnitude. Additionally, the reactive torque that would be transmitted from the bit to the surface through drill string, if the hole were straight, is absorbed by the friction between the drill string and the borehole. Thus, during drilling, there is substantially no reactive torque at the surface. Moreover, when the driller applies drill string angle corrections at the surface in an attempt to correct the bit face angle, a substantial amount of the angular change is absorbed by friction without changing the face angle in stick/slip fashion. When enough angular correction is applied to overcome the friction, the face angle may overshoot its target, thereby requiring the driller to apply a reverse angular correction. It is known that the frictional engagement between the drill string and the borehole can be reduced by rocking the drill string back and forth between a first angle and a second angle. By rocking the string, the stick/slip friction is reduced, thereby making it easier for the driller to control the weight on bit and make appropriate face angle corrections. SUMMARY OF THE INVENTION The present invention provides a method and system for directional drilling that reduces the friction between the drill string and the well bore. According to the present invention, a downhole drilling motor is connected to the surface by a drill string. The drilling motor is oriented at a selected tool face angle. The drill string is rotated at the surface location in a first direction until a first torque magnitude is reached, without changing the tool face angle. The drill string is then rotated in the opposite direction until a second torque magnitude is reached, again without changing the tool face angle. The drill string is rocked back and forth between the first and second torque magnitudes. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial view of a directional drilling system. FIG. 2 is a block diagram of a directional driller control system according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and first to FIG. 1, a drilling rig is designated generally by the numeral 11 . Rig 11 in FIG. 1 is depicted as a land rig. However, as will be apparent to those skilled in the art, the method and system of the present invention will find equal application to non-land rigs, such as jack-up rigs, semisubmersibles, drill ships, and the like. Rig 11 includes a derrick 13 that is supported on the ground above a rig floor 15 . Rig 11 includes lifting gear, which includes a crown block 17 mounted to derrick 13 and a traveling block 19 . Crown block 17 and traveling block 19 are interconnected by a cable 21 that is driven by draw works 23 to control the upward and downward movement of traveling block 19 . Traveling block 19 carries a hook 25 from which is suspended a top drive 27 . Top drive 27 supports a drill string, designated generally by the numeral 31 , in a well bore 33 . Top drive 27 can be operated to rotate drill string 31 in either direction. According to an embodiment of the present invention, drill string 31 is coupled to top drive 27 through an instrumented sub 29 . As will be discussed in detail hereinafter, instrumented top sub 29 includes sensors that provide drill string torque information according to the present invention. Drill string 31 includes a plurality of interconnected sections of drill pipe 35 a bottom hole assembly (BHA) 37 , which includes stabilizers, drill collars, and a suite of measurement while drilling (MWD) instruments including a steering tool 51 . As will be explained in detail hereinafter, steering tool 51 provides bit face angle information according to the present invention. A bent sub mud motor drilling tool 41 is connected to the bottom of BHA 37 . As is well known to those skilled in the art, the face angle of the bit of drilling tool 41 used to control azimuth and pitch during sliding directional drilling. Drilling fluid is delivered to drill string 31 by mud pumps 43 through a mud hose 45 . During rotary drilling, drill string 31 is rotated within bore hole 33 by top drive 27 . As is well known to those skilled in the art, top drive 27 is slidingly mounted on parallel vertically extending rails (not shown) to resist rotation as torque is applied to drill string 31 . During sliding drilling, drill string 31 is held in place by top drive 27 while the bit is rotated by mud motor 41 , which is supplied with drilling fluid by mud pumps 43 . The driller can operate top drive 27 to change the face angle of the bit of drilling tool 41 . Although a top drive rig is illustrated, those skilled in the art will recognize that the present invention may also be used in connection with systems in which a rotary table and kelly are used to apply torque to the drill string The cuttings produced as the bit drills into the earth are carried out of bore hole 33 by drilling mud supplied by mud pumps 43 . Referring now to FIG. 2, there is shown a block diagram of a preferred system of the present invention. The system of the present invention includes a steering tool 51 , which produces a signal indicative of drill bit face angle. Typically, steering tool 51 uses mud pulse telemetry to send signals to a surface receiver (not shown), which outputs a digital face angle signal. However, because of the limited bandwidth of mud pulse telemetry, the face angle signal is produced at a rate of once every several seconds, rather than at the preferred five times per second sampling rate. For example, the sampling rate for the face angle signal may be about once every twenty seconds. The system of the present invention also includes a drill string torque sensor 53 , which provides a measure of the torque applied to the drill string at the surface. The drill string torque sensor may implemented as a strain gage in instrumented top sub 29 (illustrated in FIG. 1 ). The torque sensor 53 may also be implemented as a current measurement device for an electric rotary table or top drive motor, or as pressure sensor for an hydraulically operated top drive. The drill string torque sensor 53 provides a signal that may be sampled at the preferred sampling rate of five times per second. In FIG. 2, the outputs of sensors 51 and 53 are received at a processor 55 . Processor 55 is programmed according to the present invention to process data received from sensors 51 - 53 . Processor 55 receives user input from user input devices, such as a keyboard 57 . Other user input devices such as touch screens, keypads, and the like may also be used. Processor 55 provides visual output to a display 59 . Processor 55 also provides output to a drill string rotation controller 61 that operates the top drive ( 27 in FIG. 1) or rotary table to rotate the drill string according to the present invention. According to the present invention, drilling, tool 41 is oriented at tool face angle selected to achieve a desired trajectory. As drilling tool 41 is advanced into the hole, processor 55 operates drill string rotation controller 61 to rotate drill string 35 in a first direction while monitoring drill string torque with torque sensor 53 and tool face angle with steering tool 51 . As long as the tool face angle remains constant, rotation controller 61 continues to rotate drill string 35 in the first direction. When the steering tool 51 senses a change in tool face angle, processor 55 notes the torque magnitude measured by torque sensor 53 and actuates drill string rotation controller 61 to reverse the direction of rotation of drill string 31 . Torque is a vector having a magnitude and a direction. When torque sensor 53 senses that the magnitude of the drill string torque has reached the magnitude measured in the first direction, processor 55 actuates rotation controller 61 reverse the direction of rotation of drill string 31 . As drilling progresses, processor 55 continues to monitor drill torque with torque sensor 53 and actuates rotation controller 61 to rotate drill string 31 back and forth between the first torque magnitude and the second torque magnitude. The back and forth rotation reduces or eliminates stick/slip friction between the drill string and the well bore, thereby making it easier for the driller to control weight on bit and tool face angle. Alternatively, the torque magnitude may be preselected by the system operator. When the torque detected by the torque sensor 53 reaches the preselected value, the processor 55 sends a signal to the controller 61 to reverse direction of rotation. The rotation in the reverse direction continues until the preselected torque value is reached again. In some embodiments, the preselected torque value is determined by calculating an expected rotational friction between the drill string ( 35 in FIG. 1) and the wellbore wall, such that the entire drill string above a selected point is rotated. The selected point is preferably a position along the drill string at which reactive torque from the motor 41 is stopped by friction between the drill string and the wellbore wall. The selected point may be calculated using “torque and drag” simulation computer programs well known in the art. Such programs calculate axial force and frictional/lateral force at each position along the drill string for any selected wellbore trajectory. One such program is sold under the trade name WELLPLAN by Landmark Graphics Corp., Houston, Tex. While the invention has been disclosed with respect to a limited number of embodiments, those of ordinary skill in the art, having the benefit of this disclosure, will readily appreciate that other embodiments may be devised which do not depart from the scope of the invention. Accordingly, the scope of the invention is intended to be limited only by the attached claims.

A method of and system for directional drilling reduces the friction between the drill string and the well bore. A downhole drilling motor is connected to the surface by a drill string. The drilling motor is oriented at a selected tool face angle. The drill string is rotated at said surface location in a first direction until a first torque magnitude without changing the tool face angle. The drill string is then rotated in the opposite direction until a second torque magnitude is reached, again without changing the tool face angle. The drill string is rocked back and forth between the first and second torque magnitudes.

RELATED APPLICATIONS The present application is a continuation of U.S. patent application Ser. No. 11/463,112 filed Aug. 8, 2006 now U.S. Pat. No. 7,847,260, which is a continuation-in-part (CIP) of U.S. patent application Ser. No. 11/348,040 filed Feb. 6, 2006, which claims the benefit of Israel Patent Application No. 166701 filed Feb. 6, 2005, and also claims the benefit under 35 U.S.C. §1.19(e) of U.S. Provisional Applications 60/649,541 filed Feb. 4, 2005; 60/651,622 filed Feb. 11, 2005; 60/654,964 filed Feb. 23, 2005. U.S. patent application Ser. No. 11/348,040 also claims the benefit under 35 U.S.C. §1.19(e) of U.S. Provisional Applications 60/706,013 filed Aug. 8, 2005; 60/706,752 filed Aug. 10, 2005; 60/707,154 filed Aug. 11, 2005; 60/709,428 filed Aug. 19, 2005; 60/710,891 filed Aug. 25, 2005; 60/596,769 filed Oct. 20, 2005; 60/596,814 filed Oct. 24, 2005; 60/597,354 filed Nov. 28, 2005; 60/597,434 filed Dec. 1, 2005; 60/597,435 filed Dec. 1, 2005, 60/597,569 filed Dec. 10, 2005; 60/597,629 filed Dec. 14, 2005; and 60/767,379 filed Mar. 23, 2006. The disclosures of all applications are incorporated herein by reference. FIELD OF THE INVENTION The present invention is in the field of threat detection and in particular the detection of nuclear/radiological threats. BACKGROUND OF THE INVENTION For a number of years governments have been struggling with how to keep terrorists from trafficking in special nuclear materials (SNM) and devices containing such materials and radiological dispersion devices (RDD). Such materials include weapon grade Uranium (WGU) and weapon grade Plutonium (WG) and radioactive sources used for RDD. Such trafficking can take place by people, car, truck, container, rail, ship or other supply chain means. There is a long perceived need for a cost/effective system to screen, detect, locate and identify SNM or RDD materials or devices that are being transported. Furthermore there is a long felt need for an effective means to scan, locate and identify suspected areas in which those threats may be present. Such screening is difficult in practice due, at least in part, to the environment in which it is done. Firstly, environmental radiation (including terrestrial and atmospheric radiation) of gamma rays and neutrons is substantial. Secondly, benign Normally Occurring Radiological Materials [NORM] like K-40 occur in nature and are present in many benign cargos. For example, kitty litter, plywood, concrete and bananas, emit substantial amounts of benign radiation. Additionally, humans undergoing nuclear medicine imaging or radiation treatment using implanted radioactive seeds can emit sizeable amounts of radiation. These and other “natural” or “benign” sources of radiation: this phenomena coupled with the ability to shield the SNM and RDD, make simple detection schemes either ineffective in finding nuclear radiological threats or prone to a poor receiver operating characteristic (ROC), for example a large percentage of false positives. Substantial numbers of false positives produce a large number of vehicles that have to be searched or otherwise vetted manually, making such simple systems practically useless for screening large numbers of vehicles. At present the leading means to screen RDD and SNM trafficking vehicles are the so called next generation Advanced Spectroscopic Portals (ASP) developed recently for the U.S. DHS DNDO. More than 90% of the ASP systems use an array of 8 or 16 relatively small NaI(Tl) scintillators (e.g., 0.1×0.1×0.4 meter), to detect the gamma energy spectroscopic signatures of SNM and RDD, and a small array of He-3 Neutron detectors to detect and count neutron emissions. ASP systems do not provide nuclear imaging of either gamma rays or neutrons. ASP systems detection performance is limited primarily due to the high cost of NaI detectors, which limits the system detection area/sensitivity. Because of the high price and practical cost constraints, the NaI(Tl) and He-3 detectors, their number is small [typically the ASP NaI detectors have a sensitive area is 0.64 meter 2 ] relative to the distance from the threat radiation source, resulting in a small solid angle of the detector as viewed by the threat. This limits the detection sensitivity. It is noted that while, for a given stand-off distance, the total detected radiation (background radiation and the threat radiation) is proportional to the solid angle subtended by the detectors at the emitting radiation sources, the background radiation sigma (statistical standard deviation) is proportional to the square root of the solid angle. Thus, a 100 fold increase in solid angle (≈detector size) results in a 10 fold increase in detection certainty (number of standard deviations above the mean) to threats in a given screening condition. For example, if the small area (i.e. small solid angle) could reliably detect a source with 10 microCurie of activity, the 100 times larger detector will detect 1 microCurie with the same certainty (same rate of true and false detections, given the same geometry and background radiation). Furthermore, the ASP detects only one threat signature for WGU and RDD—its gamma spectroscopic signature, since such materials do not emit neutrons in an amount much different from background. For WGP it detects also a second signature its neutron emission. Having only a single signature makes the system less reliable. In addition, ASP systems do not provide several other SNM-RDD signatures such as 1D, 2D and 3D nuclear imaging, temporally based signatures such as cascade isotopes (e.g. Co 60 ) doublets detection and gamma/neutron salvo emanating from spontaneous fission of SNM. Having such additional signatures would improve the ROC. These and other limitations are known in the art and drove the DHS DNDO to publish the BAA-06-01 document. This publication states the need to come up with transformational technologies which will provide a much better than ASP SNM signatures detection performance, such as lower cost detectors, improved energy resolution detectors, the use of other than gamma energy spectroscopy SNM-signatures (e.g spontaneous fission signature, imaging), detection of incident gamma or neutron directionality and other means that improve the overall system ROC. The prior art teaches that organic scintillators (OS) provide a highly robust and stable material that is easily formable in many shapes and has the best detection sensitivity when cost per detected Gamma events is considered. On the other hand, there is a common belief in the prior art that organic scintillators, although some non-spectroscopic OS based portals have been used in the past, fail to provide acceptable ROC as they do not provide energy resolution (or at best a very limited one) in the context of nuclear threat detection. This explains why organic scintillators haven not been used for direct gamma spectroscopy isotope identification in nuclear radiological spectroscopic portals (NRSPs) (in the way NaI(Tl) and HPGe detectors are used in ASP) to identify and/or provide reliable energy window of SNM, RDD and NORM selected gamma energies. Furthermore, it is accepted that for all practical purposes screening portals organic scintillators have a poor gamma efficiency or “stopping power” at energies above 300 keV as compared to NaI(Tl). A review of this issue is given in: Stromswold, D. C. et al., “Comparison of plastic and NaI(Tl) scintillators for vehicle portal monitor applications” in: Nuclear Science Symposium Conference Record, 2003 IEEE, Vol (2) pp. 1065-1069. October 2003. The disclosure of this paper is incorporated herein by reference. In recent studies related to anti-neutrino detection (see http://arxiv.org/ftp/physics/papers/404/0404071.pdf) and in other publication of the same group (see F. Suekane et al., “An overview of the KamLAND 1; K-RCNP International School and mini-Workshop for Scintillating Crystals and their Applications in Particle and Nuclear Physics Nov. 17-18, 2003, KEK, Japan, it has been shown that extremely large (8 meter diameter) expensive (>$100 million, due mainly to the very large detector size and large number of large [18″] photomultiplier tubes (PMTs) used) liquid scintillator detectors can provide gamma energy resolution which is close to that of NaI(Tl). Such devices are not practical for large scale (or even small scale) deployment for threat detection due to their geometry and astronomical cost. The disclosure of this paper is incorporated herein by reference. R. C. Byrd et al., in “Nuclear Detection to Prevent or Defeat Clandestine Nuclear Attack”, IEEE Sensors Journal, Vol. 5 No. 4, pp. 593-609, 2005, present a review of prior art of SNM-RDD screening, detection and identification techniques. The disclosure of these papers is incorporated herein by reference. In a PNNL report by Reeder, Paul L. et al., “Progress Report for the Advanced Large-Area Plastic Scintillator (ALPS) Project: FY 2003 Final” PNNL-14490, 2003, a PVT light collection efficiency of 40% for a 127 cm long detector is described. It should be noted that a straight forward extension to 4 meters length of the PNNL OS approach would have resulted in less than 25% light collection and less than 15% light collection for a 6 m long detector. The disclosure of the PNNL report is incorporated herein by reference. Further information on the state of the art can be found in the Background section of and referenced prior art listed and included by reference in the above referenced US patent application and provisional patent applications. SUMMARY OF THE INVENTION An aspect of some embodiments of the invention is concerned with a detector for nuclear threat detection. In an exemplary embodiment of the invention, the detector is segmented such that gamma rays can be transmitted substantially without impediment between segments while light generated by scintillations within a segment stays substantially within that segment. Optionally, the detector is a planar detector formed as a series of elongate detector segments placed side by side. Preferably, the detector is also segmented in a direction normal to the plane of the detector, by light reflecting, low Z radiation passing barriers, such that light from scintillations that occur at different depths in the detector are confined to the detector segments in which they occur. Since the barriers are substantially transparent to gamma and neutron radiation, gamma and neutron radiation that contains residual energy after a scintillation can pass substantially unimpeded to a different segment. For nuclear threat detection in vehicles, such as trucks and maritime containers a 4 m×4 m×0.5 m detector assembly is typically segmented into 200 elongated segments, each measuring 0.1 m×0.1 m×4 m. However, the cross-section of the elongate segments can have various other forms in addition to the rectangular form indicated above. In an exemplary embodiment of the invention, at least two photo-sensors, such as a photomultiplier tube (PMT), are optically coupled to the ends of each segment. The coupled photo-sensors collect light from the ends of the scintillator segments. By comparing the time and/or intensity of the light detected at the two photo-sensors (or signals generated by the photo-sensors in response to the light), the position of the initial scintillation within of the segment can be estimated using one or both of time of flight (TOF) techniques and the ratio of the PMT signals. As the total charge emanating from the two PMTs is integrated, it represents the total collected light, which can be used to determine the deposited energy of the scintillation, especially after the segment is calibrated as described herein. Thus, a two dimensional array of such elongate segment can be used to localize the position of the incident particle scintillation within the detector assembly in three dimensions. By summing the signals produced by the individual PMTs in response to the scintillations, determine the incident particle energy, assuming full energy deposition within the detector volume. It should be understood that such scintillators can be made of any scintillating material. However, the present inventor has found that organic scintillators and especially liquid organic scintillators (LS) have the requisite requirements for detection of nuclear threats. Typical LS for use in the invention comprises a cocktail of (for a 4 m×4 m×0.5 m volume detector) 12 kg PPO 6.3 m 3 normal-dodecane and 1.6 m 3 pseudo cumene. The barriers can be of any material. One useful material is thin nylon sheets, coated with a thin layer of reflecting paint. In some embodiments of the invention, the segments are formed by creating such partitions in a bath of LS material. In an embodiment of the invention, the detector is a 2D imaging detector. It is capable of imaging suspected one or both of gamma rays and neutrons. In one embodiment, the detector is fitted with high Z (e.g. lead) collimators for gamma collimation. Alternatively or additionally, the detector is formed of segments, some of which act as collimators for other segments, since they absorb both gammas and neutrons. This second option is also useful for imaging neutrons, which the present inventor believes has never been previously achieved, especially in WGP threat detection devices. Alternatively or additionally, gross direction capability for both incident gammas and neutrons is achieved even without collimators. As to gamma rays, the incident gamma rays produce a number of scintillations as they travel through the detector segments. The side of the detector, the 2D positions facing the screened item, sub-nanosecond event times, and deposited energy of these scintillations are determined, and a gross direction of incidence of the gamma ray is estimated from analysis of positions of the first and second scintillations. This methodology is especially useful in reducing terrestrial and atmospheric radiation by a veto on particles that most probably come from a direction other than the direction of the screened object. As to neutrons, it is possible to determine if the neutrons entered the detector from the top, sides, front side facing the screened object or rear side facing to screened object, since neutrons of typical WgP spontaneous fission energies are captured within the first 5-10 cm of OS detector material. This enables the rejection of more than a half the environmental neutron radiation and an increase in selectivity (e.g., improved ROC) of the system. Optionally, since a number of images are obtainable as the vehicle passes the large detector, linear (partial views tomography) using one or two slanted collimation means or trans-axial tomography can be performed by using more than two detectors. There is also a possibility to provide concurrently linear and transaxial tomography. Techniques for performing such tomography in the field of X-ray and nuclear tomography are well known, but have not been applied to nuclear threat detection. An aspect of some embodiments of the invention is concerned with large area detectors (optionally imaging detectors) preferably having >85% stopping power at 0.1-3 MeV gamma energy range suitable for screening a threat “vehicle” such as a person, car, truck, container, package, train, aircraft or boat. Generally speaking, such detectors are very expensive due to the cost of the detector assembly, the costs of scintillators and/or the costs of the relatively large numbers of photo-sensors or direct nuclear detectors like high purity germanium HPGe detectors that are required. A segmented OS (e.g. LS or PVT) detector according to some embodiments of the invention allows for the construction of a large detectors having extremely high sensitivity for both neutrons and gammas, NaI(Tl) like gamma energy resolution, temporal resolution and intrinsic gamma and neutron spatial resolution that are suitable for reliable nuclear/radiological threat detection for the cost of the most advanced prior art methods. In some embodiments of the invention, the detector, the associated circuitry and software algorithms are capable of identifying and rejecting incident gammas which do not deposit all of their initial energy in the detector. The identification and rejection of so called “escape quanta” events allows for better gamma spectroscopy isotope identification and/or energy windowing. In some embodiments of the invention a loci dependent light collection efficiency correction is applied to the detector segments energy signals. This correction mitigates a significant variable of loci dependent energy signals, resulting in a better energy resolution. In a preferred embodiment of the invention, a segmented LS detector having high light reflecting partitions, coupled to PMTs photocathodes which cover more than 73% of the segments cross section is used. In some embodiments, LS filled optical couplers are used to match the sizes of the PMT and the segments. Such segments use OS such as the PPO based LS described above which have a “mean attenuation length” larger than 15 meters and an index of refraction of approximately 1.5 to match the PMT glass index of refraction. The PMT face is preferably in contact with the LS. This ensemble may, under some circumstances, provide near 50% or even more light collection efficiency, even for long 3-6 meter detector segments. This increases the number of photoelectrons per MeV at the PMTs, resulting in better energy resolution. It should be noted that one of the reasons that the prior art believes that OS detectors had poor gamma spectroscopic ability was the low light collection efficiency of elongated scintillators that might be useful for threat detection. In some embodiments of the invention an OS scintillator assembly larger than 1×1×0.4 meter is used to allow most of the incident gammas having energies of more than 2.6 MeV to deposit their full energy in the scintillator assembly, thus eliminating most of the gamma energy resolution loss due to escape quanta associated with smaller detectors. In a typical embodiment, a scintillation detector approximately 50 cm deep can have a 4×4 or 6×4 (length×height) meter front face. Larger devices can be constructed, and smaller sizes, such as 2×2 m can be useful for “car size only” or pallets lanes. Such large detectors have a number of potential advantages. One advantage is that the efficiency of capture of gammas and neutrons emanating from the screened field of view is greatly improved, due to the large subtended angle that they present to the radiation sources. If radionuclide imaging using high Z collimators is implemented this high gamma sensitivity hike is reduced. A second advantage is that the efficiency of detecting temporally coincident SNM RDD signatures like cascaded isotopes and spontaneous fission gamma/neutron salvos is increased. For example, doublet capture is greatly improved, since the probability of doublet capture is roughly the square of the probability of singlet capture. A substantial percentage of doublet capture results in improved discrimination between some doublet emitting threats like Co −60 and non-threatening radiation and improved sensitivity to threatening radiation. It should be noted that the probability of random chance detectability of doublets is extremely low as the background radiation rate is low approximately 1-3 kcounts per second per square meter, while the doublets detection temporal coincidence window is short (about 20 nanosec). Another advantage of large detectors, especially imaging detectors, is the amount of time each portion of a moving vehicle is screened. Taking into account the movement of the vehicle, every portion of a moving vehicle is captured for almost 40 times as long by a four meter long imaging detector as by a detector having an ASP 10 cm detection length in the direction of movement of the vehicle. This allows for √{square root over (40)} increase in signal to background radiation discrimination which translates into the detection of threats with less than ⅙ the activity. Another aspect of this advantage is that compared to the ASP requirement to move the vehicle at 5 MPH, we can theoretically move the vehicle at 5×40=200 MPH and get the ASP number of detected particles. In practice the length of the detector allows screening at highway speeds of 60 MPH while getting close to twice the detectability of an ASP at 5 MPH. Thus, it is possible to get, at highway speed, a higher detectability then that specified for ASP at only 5 MPH. An aspect of some embodiments of the invention is concerned with a non-imaging and/or imaging detector that can detect both gamma rays and neutrons and provide spectral and/or spatial imaging of the radiation of at least one of the kinds. Optionally, both kinds are screened. This allows for the use of a single detector for sensing a wide range of threat signatures. An aspect of some embodiments of the invention is concerned with a detector that can identify the general or gross direction of an incident gamma and/or neutron particle independent of the use of a collimator and/or shielding. In an embodiment of the invention, at least some events that are incident from a direction other than a direction from which they are expected when screening an object, can be rejected. This allows for a decrease in background radiation both from environmental radiation and from radiation emanating from other objects (e.g. nuclear medicine patients outside the field of screening). In addition, it enables the rejection of events that enter from the back, sides, top and bottom of the detector. Rejecting events that do not come from the expected direction can increase the reliable threat detectability of the system many fold. An aspect of some embodiments of the invention is concerned with imaging guided spectroscopy. In this process, the imaging capability of the detector is used to detect point sources that could be identified as an RDD or SNM or a case of NORM point source at some limited probability (e.g. three to four standard deviations over the ocean of background). To further identify if the point source is a benign (e.g. NORM) or threat, a spectroscopic isotope ID is then applied over a limited area (for example, 1 square meter) around the suspected point source. This eliminates from the spectra most of the non-target background radiation, greatly improving the ability to identify the spectral signature of SNM or RDD. An aspect of some embodiments of the invention is the provision of one or a plurality of energy windowed images on an isotope-by-isotope basis. This technique is used in nuclear medicine imaging to provide maps of individual isotopes. Providing maps for different isotopes in threat detectors improves the image and its point source contrast over the ocean of background radiation. An aspect of some embodiments of the invention is concerned with an organic scintillator with both intrinsic spatial and temporal resolution and spectrographic properties to discriminate between isotopes. In an embodiment of the invention, the presence of escape quanta can be detected for a given incident particle, and the event vetoed. This can provide a significant improvement in spectroscopic isotope identification. The combination of high light detection efficiency and high and uniform collection efficiency associated with loci dependent light collection variation correction and the small rate of escape quanta (due to the large detector) allows for gamma spectroscopic isotope I.D. that is similar to that of detectors with NaI(Tl) scintillators. It should be noted that the exact design of the detector is dependent on a tradeoff between gamma spectroscopic identification and imaging capability. If imaging capability is desired, then some kind of collimation may be required. This reduces the capture efficiency based threat signatures performance. On the other hand, if high particle collection efficiency is desired, for spectroscopy, and temporal coincidence signatures (e.g. cascading isotopes I.D. spontaneous fission gamma/neutron I.D.) detection (discussed below) no collimators are more desirable. In some embodiments, a combination of areas that have collimation and areas that do not have collimation provide a compromise design. Such embodiments are discussed herein. An aspect of some embodiments of the invention is related to a novel class of detectors which combines high spatial resolution over some areas of the detector and high system sensitivity over the other areas of the detector. As indicated above, only gross directionality of the incoming radiation can generally be determined without collimation. In particular, it is noted that gamma rays give up their energy in an organic scintillator material, in a series of time and geometrically spaced events (e.g. Compton interactions), each of which produces a separate scintillation. In general, it is preferred to have the size of the segments matched to a mean length between scintillations (this indicates a compromise between low [100 KeV gammas having a short distance] and high energy gammas [2.6 MeV having a long distance]), such that the position of each event in the detector is, with high probability, in a different segment. The time constant of a single scintillation is the same order of magnitude (a few nsec) as the time between scintillations of the same event, hence they can not easily be discriminated from each other by time. If, however, they occur in different segments, their leading edge timestamp, deposited energy and 2D location are separately detected and measured. This allows the use of algorithms used in Compton imaging techniques to detect the gross directionality of the incident gamma. This allows rejection of gammas that are incident from the back face and to a great extent terrestrial and atmospheric gammas and neutrons. The requirements for neutron detection are different. In general, the energy (other than the rest energy) is given up over a short path length. This path length is within one or two segments and thus only gross direction can be determined for such events, for example whether the neutron entered the front detector face, the top or the back detector face. To determine improved directionality for either type of particle, some collimation is often desirable. Since the spatial resolution required is very modest (˜0.4-1 Meter FWHM), the collimation can be modest as well. In an embodiment of the invention, some areas of the detector have relatively high collimation and other areas have low or no collimation, but are relatively thick. In a preferred embodiment of the invention, the thick and thin areas are interleaved and the thick areas provide some or all of the collimation of the thin areas. This detector self-collimation method allows for imaging of both gammas and neutrons. In some embodiments of the invention, collimation is applied only for gamma rays and optionally only over a part of the detector to allow for both imaging and high detection (capture) efficiency. In general, in prior art nuclear threat detection systems the detection sensitivity for gamma rays is so small (due to the small size of the detectors) that the detection rate for doublets does not allow for consideration of doublets or spontaneous fission γ/N salvos, for identification of cascading sources. An aspect of some embodiments of the invention is related to multi-lane chokepoints where a single detector is used to scan threats in lanes on both sides of the detector. Thus, it is possible to scan N lanes nuclear threat portals in which only N+1 detectors are used instead of 2N detectors to form gamma and/or neutron screening of threats in adjoining lanes. This saving in number of detectors uses the unique property of the detector to identify whether an incident gamma and/or neutron entered from the back or front of each detector assembly. An aspect of the invention is concerned with screening for vehicles moving at highway speeds. As this design allows the fabrication of 4-6 meter long detectors (in the vehicle's travel direction) vs. the 0.1 meter of ASP, the detection sensitivity is 40-60 times that of an ASP. Thus, detectors of the type described herein can provide sensitivity to a target moving at 60 mph that is >3 times that for ASP for targets that move at 5 mph. This level of sensitivity opens the possibility of screening of vehicles in highway traffic. Optionally, the detector is covertly mounted in a screening vehicle providing a roadside and on the road moving optionally covert screening portal. Optionally, the detectors can be covertly mounted under the road and/or in tunnels, walls or bridges. While the invention is described mainly with respect to closely packed segments with rectangular cross-sections, in some embodiments of the invention the individual detector segments have non rectangular cross section such as a cylindrical form to improve the scintillation light collection efficiency to improve light collection efficiency and/or uniformity thus improving gamma energy resolution. Alternatively or additionally, the segments are spaced from each other. In some embodiments of the invention, the SNM-RDD screening portal images are fused or correlated with CCTV imaging of the vehicle. The position of the image in the vehicle can be used as an indicator of whether the detected material is a threat. This has been discussed in the above referenced regular U.S. patent application Ser. No. 11/348,040. In some embodiments of the invention, the partitioning of the large detector consists of various sizes of detector sections, with smaller partitions being used near the front face of the detector. There is thus provided, in accordance with an embodiment of the invention, a detector for detecting nuclear radiation threats, the detector comprising: a plurality of elongate scintillator segments arranged in a side by side array; and at least one pair of light sensors optically coupled to ends of each of the elongate scintillator segments such that they receive light from scintillations produced in the scintillator segments and generate electrical signals responsive thereto. In an embodiment of the invention, the segments are separated by partitions that are substantially transparent to gamma radiation and are reflectors for light. Optionally, the segments are contiguous, separated only by said partitions. Alternatively, the scintillator segments are at least partly non-contiguous. Optionally, the segments have a rectangular cross-section perpendicular to the elongate direction. Alternatively, the segments have a circular cross-section perpendicular to the elongate direction. In an embodiment of the invention, the scintillator segments comprise an organic scintillator, optionally a liquid organic scintillator. Optionally, the light sensors have input face plates and wherein the faceplates are in direct contact with the liquid organic scintillator. Optionally, the detector includes: a controller that receives the electrical signals and generates an image of the sources of radiation that cause the scintillations. Optionally, the scintillator produces scintillations responsive to incoming neutrons, and the detector further comprises: a controller that receives the electrical signals and determines the positions of the incident neutrons on the detector. Optionally, the scintillator produces scintillations responsive to incoming neutrons, and the detector further comprises: a controller that receives the electrical signals and generates an image of the sources of neutron radiation that cause the scintillations. Optionally, the detector includes: a controller that receives the electrical signals, and produces an energy value, the energy value being responsive to the electrical signals, wherein the energy value is corrected based on the location of the scintillation within the scintillator segment. In an embodiment of the invention, the detector includes: a plurality of collimators on a front face of the organic scintillator that block radiation that would be detected by the said detector from parts of the radiation field. Optionally, the plurality of collimators restrict block radiation over only a portion of the front face. Optionally, the plurality of elongate scintillators form a detector having a front face having a total area greater than 1 meter by 1 meter. In an embodiment of the invention for detecting nuclear threats that generate one of both of neutrons and gammas, wherein the photo-detectors receive light of scintillations in the liquid organic scintillator caused by gammas and neutrons; and including: a controller that receives the electrical and generates both a count of the incident neutrons and a spectroscopic energy analysis of the gammas. In an embodiment of the invention, wherein the plurality of elongate scintillators form a detector having a front face and a back face and the scintillators produce scintillations in response to radiation that enters the detector via the front face and the back, the detector comprising: a controller that receives the electrical signals, and discriminates between the radiation entering the front and rear faces. In an embodiment of the invention where the plurality of elongate scintillators form a detector having a front face, the detector comprising: a controller that receives the electrical signals, generates a gross direction of incidence of the incident radiation from said signals, without considering the presence or absence of collimation and rejects at least some incident radiation particles that do not come from a direction at which a suspected source is situated. In an embodiment of the invention where the plurality of elongate scintillators form a detector having a front face, the front face is not flat, and alternating portions of the front face extend further front than other portions. In an embodiment of the invention a plurality of said arrays are stacked in a direction perpendicular to the direction of said array to form a three dimensional array of said elongate scintillator segments. In a embodiment of the invention the plurality of segmented detectors comprise a plurality of segments formed of a series of light reflecting low atomic weight partitions placed in a vessel filled with liquid scintillator material, such that the partitions form the individual elongate segments. Optionally, the detector includes: a controller that receives the electrical signals and generates a timestamp reflecting the time that the light arrives at the photo-detector. Optionally, the sum of the signals relating to an incident particle is proportional to the total energy deposited in the detector by the incident particle. Optionally the light sensors are photomultiplier tubes (PMTs). Optionally, the controller corrects the timestamps for systematic variations of PMT light channel delays. Optionally, the controller corrects the signals for loci dependent light collection efficiency systematic variations. Optionally, the thickness of the stacks is deep enough to allow full energy deposition in the detector for more than 60% of 2.6 MeV gamma particles incident at the center of the front face. Optionally the detector is utilized in a screening portal having a lane, wherein a detector is placed at one side of the lane, or on each side of the lane. Optionally, a plurality of detectors are spaced to form a plurality of vehicle lanes and where a single detector is utilized to detect radiation from adjoining lanes. Optionally the detector is utilized in a screening portal having a lane wherein the at least one detector surrounds at least 50% of the lane. Optionally the detector is utilized in a screening portal having a lane wherein the at least one detector surrounds at least 75% of the portal opening or completely surrounds the portal opening. Optionally, the detector is mounted in a vehicle to provide a portable nuclear threat screening device. Optionally the detector includes a controller that identifies a plurality of scintillations as emanating from a single incident particle based on a time window within which they fall and their spatial proximity within the detector. Optionally, the detector function is disguised or hidden so that it detects threats in a covert manner. Optionally, the detector includes: a source of activating radiation that stimulates emission of radiation from SNM and radiation shielding materials, wherein the scintillator segments are positioned to receive said stimulated emission. Optionally the detector includes: a controller that receives the electrical signals and generates a tomographic image of sources of the radiation. Optionally, the scintillator is a PPO based liquid scintillator. There is further provided, in accordance with an embodiment of the invention, a system for detection of radiation signatures of SNM and RDD devices and materials from a screened object, comprising: at least one scintillator which produces scintillations when impinged by gamma and neutron radiation; a plurality of optical sensors optically coupled to the at least one scintillator such that they receive light from scintillations produced in the scintillator and generate electrical signals responsive thereto; and a controller that receives the signals and performs a multi-signature detection of threats including a plurality of the following threat detection inputs or characterizations: (a) gamma spectroscopy isotope signature; (b) gamma imaging morphologic signature; (c) neutron counting; (d) neutron imaging; (e) cascaded isotopes doublets or triplets signature; (f) SNM spontaneous fission signature; (g) comparison with optical images of the screened object; and (h) gross directionality of incidence of radiation as compared to the direction of the screened object. Optionally, the at least one scintillator comprises a segmented organic scintillator comprising at least four elongate segments. Optionally, the scintillator comprises a liquid scintillator. Optionally, the detector comprises at least three, four, five or more of said threat detection inputs or characterizations. There is further provided, in accordance with an embodiment of the invention, a detector for detecting incident neutrons, comprising; at least one scintillator that produces scintillations responsive to incoming neutrons produced by WPG; a plurality of photo-detectors that receive light of the scintillations and produces electrical signals responsive thereto; and a controller that receives the electrical signals and generates an image of the sources of neutron radiation that cause the scintillations. There is further provided an SNM detection system, effective to screen vehicles moving at a velocity greater than 40 MPH. There is further provided a method of SNM detection comprising screening a suspected item by placing it before at least one detector while the item is stationary to increase the number of radiation events captured by the detector. There is further provided, in accordance with an embodiment of the invention a detector for detecting radiation, comprising: an organic scintillator; a plurality of photo-detectors that receive light of scintillators in the organic scintillator and generates electrical signals responsive thereto; and a controller that receives the light and generates an image of the sources of radiation that cause the scintillations. There is further provided, in accordance with an embodiment of the invention a detector for detecting incident neutrons, comprising; a scintillator that produces scintillations responsive to incoming neutrons; a plurality of photo-detectors that receive light of the scintillations and produces electrical signals responsive thereto; and a controller that receives the electrical signals and determines the positions of the incident neutrons on the detector. There is further provided, in accordance with an embodiment of the invention a detector for detecting radiation, comprising: an organic scintillator element; a plurality of light sensors functionally connected to the scintillator such that they receive light from scintillations produced in the scintillator and generate electrical signals responsive thereto; and a controller that receives the electrical signals, and produces an energy value, the energy value responsive to the electrical signals, the energy value being corrected based on the location of the scintillation within the scintillator element. There is further provided, in accordance with an embodiment of the invention a detector for detecting radiation, comprising: an organic scintillator; a plurality of light sensors functionally connected to the scintillator such that they receive light from scintillations produced in the scintillator and generate electrical signals responsive thereto; and a plurality of collimators on a front face of the organic scintillator that restrict the field of view of portions of the scintillator. Optionally, the plurality of collimators restrict the field of view over only a portion of the front face. There is further provided, in accordance with an embodiment of the invention a detector for detecting radiation, comprising: an substantially planar organic scintillator having an input face greater than 1 meter by 1 meter; a plurality of light sensors functionally connected to the scintillator such that they receive light from scintillations produced in the scintillator and generate electrical signals responsive thereto; and a controller that receives the electrical signals, and produces an energy value, the energy value responsive to the electrical signals, the energy value being corrected based on the location of the scintillation within the scintillator element. There is further provided, in accordance with an embodiment of the invention a detector for detecting nuclear threats that generate one of both of neutrons and gammas, the detector comprising: a liquid organic scintillator that produces light scintillations responsive to interactions with gammas and neutrons that are incident thereon; a plurality of photo-detectors that receive light of scintillations in the liquid organic scintillator and generates electrical signals responsive thereto; and a controller that receives the electrical signals and generates both a count of the incident neutrons and a spectroscopic energy analysis of the gammas. There is further provided, in accordance with an embodiment of the invention a detector for detecting radiation, comprising: a substantially planar scintillator having at least a front and back side; a plurality of light sensors functionally connected to the scintillator such that they receive light from scintillations produced in the scintillator from radiation that enters the scintillator via the front and rear faces and generate electrical signals responsive thereto; and a controller that receives the electrical signals, and discriminates between the radiation entering the front and rear faces. There is further provided, in accordance with an embodiment of the invention a detector for scanning to determine a source of radiation, comprising: a substantially planar scintillator having a front surface for receiving radiation; a plurality of light sensors functionally connected to the scintillator such that they receive light from scintillations produced in the scintillator from radiation that enters the scintillator and generate electrical signals responsive thereto; and a controller that receives the electrical signals, generates a gross direction of incidence of the radiation from said signals, without considering the presence or absence of collimation and rejects at least some scintillations that do not come from a direction at which a suspected source is situated. There is further provided, in accordance with an embodiment of the invention a detector for detecting radiation, comprising: an organic scintillator unit having a front face and a back; and a plurality of light sensors functionally connected to the scintillator such that they receive light from scintillations produced in the scintillator from radiation that enters the scintillator and generate electrical signals responsive thereto; wherein the front face is not flat, and wherein alternating portions of the front face extend further front than other portions. BRIEF DESCRIPTION OF THE DRAWINGS Exemplary, non-limiting, embodiments of the invention are described below in conjunction with the following drawings, in which like numbers are used in different drawings to indicate the same or similar elements. FIG. 1 is a schematic drawing illustrating a general view of part of a threat-detecting portal in accordance with an embodiment of the invention; FIGS. 2A and 2B illustrate two kinds of events that occur in nuclear threat materials; FIG. 3 is a partial cut-away drawing of a detector assembly in accordance with an embodiment of the invention; FIGS. 4A and 4B are plane views of two types of elongated detector segments, in accordance with an embodiment of the invention; FIG. 5 is a schematic drawing similar to FIG. 1 , which also illustrates the incident gamma and neutron interactions which take place in detectors of the type described with respect to FIGS. 3 , 4 A and 4 B; FIG. 6 shows Cs-137 energy spectrum comparisons between a PPO based LS detector without escape quanta veto and with escape quanta veto; FIG. 7 shows U-232 (daughter) 2.6 MeV energy spectrum comparisons between a NaI(Tl) based detector and a PPO based LS detector according to an embodiment of the invention; FIG. 8 is a schematic block diagram of exemplary front-end electronics, for use with each elongate segment of FIGS. 4A and 4B ; FIG. 9 illustrates various interactions of incident gammas with the segmented detector and a methodology for rejection of events which do not come through the front face; FIG. 10 is a schematic illustration of a detection portal according to an embodiment of the invention in which a partially collimated detector is used; FIG. 11 illustrates an alternate detector, in which collimation is provided, in accordance with embodiments of the invention; FIGS. 12A-12E are simplified flow charts illustrating the methodology used to determine threats and their type, in accordance with an embodiment of the invention; FIG. 13 shows a system in which additional detectors are used to improve capture efficiency and provide an option for transaxial tomography; and FIG. 14 shows a multi-lane system in which a same detector is used for adjoining lanes. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS FIG. 1 shows a schematic drawing of a portion of a system 100 for detecting nuclear threats. As illustrated, vehicles 102 , for example a truck, pass between two detectors 104 , 106 . In some embodiments only a single detector is used and in some, as described below, three or more such detectors are used. In a preferred embodiment of the invention, the detectors are of one of the types of detectors described below. The detectors are optionally high enough to cover the entire height of the truck or other objects being scanned. The length of the detector (in the direction of motion of the vehicle) is not related to the height; however in some embodiments of the invention it is made 3, 4, 6 or more meters long, so as to provide a desired detection sensitivity. For illustration purposes, vehicle 102 is shown carrying a nuclear material 108 . A controller 110 receives signals from the detectors and based on these signals, and optionally on information regarding the speed and location of the vehicle, determines whether a possible threat is present. In the event that a threat is determined, the vehicle is either stopped for further checking or sent to additional screening stations, as described with respect to FIG. 30 of the above-referenced U.S. patent application Ser. No. 11/348,040. FIGS. 2A and 2B schematically illustrate common types of emissions that occur from nuclear threat material 108 . FIG. 2A shows nuclear material (e.g. WGP) emitting both gamma rays and neutrons. The rate of emission is generally rather low and the events illustrated do not occur simultaneously, and can generally be discriminated between by the detectors 104 , 106 . In cases where simultaneous γ and neutrons as produced, they are generally separated in space (in different segments) so that they can be distinguished. It should be noted that some of the emitted particles are not directed toward the detectors. In addition to emissions in the forward and backward directions, emissions take place in a direction above and below the detectors, since the emission from the threat material is generally isotropic. In general the capture efficiency of any detector or set of detectors is proportional to the solid angle subtended by the detector as seen by the source of emissions, and its stopping power. Thus, the larger the detectors the greater the capture efficiency (sensitivity). FIG. 2B shows a cascade gamma event in which a first gamma ray is emitted in a first transition and a second gamma ray is emitted in a second emission immediately afterward. Such cascaded emissions are characteristic of some radioactive isotopes, such as Co 60 , and can form a very sensitive signature for recognition of such materials. These two cascaded emissions are shown as being directed to different detectors, however, in practice, there is virtually no correlation between the directions of the gamma rays and they can be directed to the same detector or more likely, only one of the events will be detected. Since the probability of detecting a single gamma event is proportional to the solid angle subtended by the detectors, the probability of detecting doublets is proportional to the square of the solid angle. Thus, the size of the detector is critical to the detection of doublets. FIG. 3 , shows a partial cut-away view of a segmented detector 200 (corresponding to detectors 104 and 106 of FIG. 1 , in an embodiment of the invention). In the following discussion, the visible face of the detector is referred to as a front face 202 and the other face, as the rear face. As shown in the exemplary embodiment of FIG. 3 and referring also to FIG. 4A , detector 200 is segmented into elongate segments of scintillation material (one of which is referenced with reference numeral 204 ) by reflective partitions 206 . Thus, light from a scintillation which occurs in a particular segment is reflected from the partitions and remains in the same segment. By the nature of the reflections, the light is reflected toward one or the other end of the elongate segment, where it is optionally concentrated by a light concentrator before being sensed by a light detector such as a photomultiplier tube (PMT). Two light concentrators 208 and 210 and two PMTs 212 and 214 are shown on either end of the elongate scintillation material. Preferably, the scintillation material is an organic scintillator and more preferably a liquid organic scintillator (LS) material. Typical LS for use in the invention comprises (for a 4 m×4 m×0.5 m volume detector) a cocktail of 12 kg PPO, 6.3 m 3 normal-dodecane and 1.6 m 3 pseudo cumene. The barriers can be made of low Z materials. One useful material is thin nylon sheets, coated with a thin layer of reflective paints. It should be noted that the PPO Based LS cocktail mentioned above provides extremely good transparency (20 m light loss distance) and an ideal index of refraction (1.5) and a scintillation light spectrum which matches the sensitivity spectrum of Bi-Alkali photocathodes. It should be also noted that the light concentrators are preferably filled with the LS. Organic scintillators have various advantages over other scintillators, including robustness, stability and low cost, ease of manufacturing and forming, etc. Its two major deficiencies relative to the commonly used NaI(Tl) scintillator is lower stopping power and lower scintillation efficiency of about 10.000 Photones/Mev. Both of these deficiencies are compensated for in some embodiments of the invention. Organic scintillator materials are well known and have been used for simple detectors which are not used for gamma spectroscopic applications nor for imaging applications. FIG. 4B is similar to FIG. 4A except that the segment cross section is round. It should be noted that while there are spaces between the segments when they are arranged as in FIG. 3 , this does not effect operation substantially, since these spaces do not interact significantly with the gamma rays. In an embodiment of invention the individual detector segments have a cylindrical form to improve the scintillation light collection efficiency. While the rectangular segments can be either self supported or partitions within a bath, it is believed that cylindrical segments have to be self supported. Alternatively or additionally, the rectangular segments are spaced from each other. If solid OS segments are used, then the construction is simpler and all that is need is to form the segments and paint them with light reflecting paint. When a scintillation takes place, the light generated is emitted in all directions. Thus, some of the light travels toward one end and is detected by one of the PMTs and some travels in the other direction and is detected up by the other PMT. Any light photons that are not directly aimed along the elongated segment, will reflect off the reflective walls, possibly multiple times and arrive at the end with a slight delay compared to the directly aimed photons. Since the velocity of light in the scintillation medium is known, the time difference between the ‘leading edge’ of the light signal by the two PMTs is indicative of the position of the interaction along the length of the segment. This method is known in the art as Time of Flight (TOF) localization. In addition since there is some path length dependent attenuation of the light as it travels through the scintillator material, the amplitude of the light is different at the two ends if the scintillation does not occur at the exact midpoint. In an embodiment of the invention one or both of the TOF and amplitude ratio are used to determine the position of the scintillation along elongate segment 204 . Since both time differences and amplitude ratio are affected by other factors, the segments are preferably calibrated using a procedure described below. As was shown in the incorporated regular U.S. patent application Ser. No. 11/348,040, with respect to FIGS. 27-29 , elongate detectors can be used as threat detectors with one dimensional position discrimination. As can be seen from FIG. 3 of the present application, segments 204 are stacked vertically. Thus, each such stack will provide information as to position of a scintillation occurring at its depth in both the vertical and horizontal directions, i.e., two dimensional position detection. It is noted that the depth of the detector does not by itself provide a 3D image. Scintillation materials of the preferred type detect both neutrons and gamma rays. However, the footprints of scintillations that are produced are different. In both cases, the energy of the incoming radiation is given up via a series of interactions, which result in scintillations. However, the distance between such events is different, being substantially longer for the gamma rays than for neutrons of typical energies. In an embodiment of the invention, the depth and height of the segments is such that, in many cases, a single scintillation takes place in a particular segment for gamma rays and multiple interactions, even most of the interactions, take place in a same segment for neutrons of energies that are expected from fissile materials. Another difference is the scintillation rate of decay for the two types of interactions, especially when all the scintillations caused by an incoming event is considered. This phenomenon is well known and has been used to discriminate between gamma rays and neutrons in non-imaging detectors using PSD methods. In threat detectors the rate of incoming events is generally low at rates of a few thousand counts per second per meter 2 . At such low rates, the probability that two scintillations from different incident gamma events will take place in a nearby location at the same time window is low, hence each incident particle and its associated scintillations can be analyzed individually. If the signals produced by the PMTs are time stamped and digitized, then scintillations in different segments can be correlated and the positions of a series of scintillations caused by a single incident particle can be correlated. The utility of this information will be described below. In the preferred embodiment of the invention, the partitions are substantially transparent to gamma rays and other quanta such as higher energy electrons, neutrons and protons. Thus, while light is trapped within a particular segment, residual energy, in the form of a gamma ray, or other quanta, not converted to light (or heat) in a particular interaction can pass through the partition into a neighboring (or farther) segment. In an exemplary embodiment detector 200 comprises a plurality of layers of segments, arranged in the direction perpendicular to front face 202 , as shown in FIG. 3 . Thus, an incoming incident gamma event will cause a series of scintillations as it interacts with the detector. Often, depending on the incident gamma energy, each scintillation takes place in a different segment. FIG. 5 , which is similar to FIG. 1 except that gamma and neutron events and the train of scintillations they cause are shown. As shown in FIG. 5 , nuclear material 108 emits both gamma and neutrons particles. The neutrons cause a series of scintillations, generally in one segment. These scintillations are treated as a single scintillation. This series of scintillations can be identified as being generated by a fast neutron, from a characteristic pulse shape measured by PMTs 212 and 214 ( FIGS. 3 and 4 ). It is noted that a further large scintillation at 2.2 MeV caused by the thermalized (slowed down) neutron capturing on Hydrogen may optionally be considered as an additional correlation, although the time delay for that secondary event is longer and randomly variable. Incoming gamma rays generate a more complex pattern of scintillations. As indicated above, the mean distance between scintillations could be large as compared with the cross-sectional dimensions of segments 204 . Thus, some gamma event causes a series of distinct scintillations as it moves through the detector and gives up energy. One such series is indicated by reference numerals 502 , 504 and 506 . A statistical most probable incoming direction of the event can be calculated. This direction is only a gross direction and is generally not sufficiently good for imaging. However, it does enable substantial rejection of background radiation such as terrestrial and atmospheric radiation. This is based on the fact that the direction of the gamma particle having the residual energy after Compton an interaction is related to the incoming direction. Generally, the most probably incoming direction is a straight line between the first and second scintillations. It should be noted that since detector 200 collects light from all of the scintillations caused by the incident gamma rays, the light collected by scintillator 204 can be used for spectroscopic isotope identification. The spectral resolution depends on a number of factors, some of which are correctable. One of these is a systematic variation in light collection efficiency as a function of position of the scintillation within a segment. In general, the main variable in this respect is the distance and average number of reflections that light from a scintillation event has to undergo in order to reach each of the photomultiplier tubes. This can be calculated (or measured for a typical segment, as described below) and an appropriate correction made to the energy signal (integral of the light received) indicated at the front-end electronics or system software, based on the determined scintillation position along the segment. Other correctable variations are gain and delay variations among the individual PMTs. These can also be determined as part of an overall calibration for the segment. In an experimental calibration of loci dependent light collection efficiency variation correction, according to an embodiment of the invention, a point source of mono-energetic gamma rays or high energy mono-energetic betas is placed adjacent to an individual segment and the energy signals provided by the sum of the two PMTs is measured. This is repeated for a number of positions along the length of the segment. Interactions between the OS material in the segment and the ray will cause scintillations. The signals generated by these scintillations in the PMTs at the end of the segments can be used to define a ratio of signals and a time delay between signals as a function of actual position along the segment. For betas, the entire energy is transferred in a single interaction. However, for gamma, the energy transferred in the interactions (and the energy in the scintillations) is variable. However, the peak energy scintillations can be assumed to be the result of a direct photoelectric effect interaction (or otherwise a full energy deposition within the segment) and thus their energy is known (i.e., it is the energy of the incoming gamma). This known energy and position can be used as a standard for generating a position dependent energy correction table. This measurement is repeated for all of the segments and used to provide a look-up table of corrections which enable the conversion of pairs of time-stamped light signals into energy signals and position values, which are used in the method described in FIG. 12 . Alternatively, the energy collection efficiency can be assumed to be the same for all the segments. Similarly, the collection efficiency as a function of position along the segment can also be assumed to be the same for all segments. Thus, measurements of energy signal correction factors can be approximated for all of the segments, by measurements on a single segment. Such approximation can be expected to give poorer spectral results than when energy correction is based on individual measurements of each detector. Alternatively, the absolute energy sensitivity of the individual segments is measured, and the spatial distribution is assumed to be the same for all segments. In order to do this, an energy measurement, as described above is performed, but only for a single point along the length of the segment. The sum of the values of the signals is compared to a standard and the energy efficiency of collection is determined by the ratio of the signals. Optionally, the standard is based on measurements of a number of segments. It is noted that this alternative also gives a time difference between the detectors on both ends of the segment. However, neither this nor the other alternative methods of energy signal calibration allow for determination of an absolute time delay, which is used for some embodiments of the invention. Absolute time delay (and a correction for such delay variations) for each PMT channel can be determined by feeding a light signal that simulates a scintillation into the segment and then measuring the time delays of the signals outputted by each of the two PMTs at the ends of the segment. If the signal is fed into center of the segment for all of the segments, the time delays of all of the PMTs channels for all the segments can be determined so that a comparison of the times of the signals from each PMT can be used to provide a consistent time stamp for each scintillation event. It is noted that the segments partitions are coated by a light reflecting material. In order to feed light into the segment, a very small portion of the segment is left uncoated at the center of the segment. Optionally, an LED is embedded in the segment wall and the delay testing is performed on the segments in the assembled detector. These measurements can be performed periodically to partially compensate for instability or drift of the PMTs. Optionally, alternatively or additionally, the PMTs and their associated circuitry are calibrated before assembly by feeding a light impulse of a standard intensity and timing into the PMT. The output of the circuitry is then measured and the gain and delay is noted and used to determine a correction factor for both energy measurement and timing. Optionally, the circuitry is adjusted to change the gain and time delay such that the outputs of all the PMTs have the same integrated signal output and timestamps. Optionally, the PMTs can be removed from the rest of the segments so that they can be replaced, or adjusted when they go out of the calibration range. If the segments are not separable (e.g., they are in a bath) other methods can be used to determine energy and time delay corrections. In this case a collimated beam of high energy gammas (e.g., 1.4 MeV of K-40) is introduced perpendicular to the face of the detector. This beam has a substantial half length in the LS, before the first interaction and some of the interactions will be photoelectric interactions. The energy of these interactions is known and the difference in signals produced in the various segments (also as a function of position along the segments) is used to calibrate for energy. It can also be used to calibrate for position determination using signal strength, using the ratio of signals when the beam is at the center of the section as a standard correction for the ratios produced during detection of threats. This measurement can also define a relative difference in delay between the two end PMTs which can be used to determine the y position correction. As to absolute timing, this can be determined to a reasonable accuracy by the use of LEDs situated near each of the PMTs. An additional source of reduction in gamma spectroscopic isotope ID quality is caused by energy that is lost when a residual gamma or electron escapes from the detector. While this phenomenon is well known, correcting for it is difficult, since it can not be determined on an individual basis if such escape occurred and also how much energy escaped. The result will be that the spectrum of an monoenergetic gamma source will have a lower energy pedestal as seen in FIGS. 6 and 7 . It has been found that in general most incoming gamma rays of a given energy have a certain range of number of scintillations before they give up all their energy. If events that have below this number of scintillation are rejected, then the spectrum is substantially improved, at the expense of some loss of events. This phenomenon is shown graphically in FIG. 6 . FIG. 6 shows the results of two Monte Carlo. simulations. One without and one with escape quanta veto. The first simulation (represented by the upper spectrum) is a straight forward single energy gamma spectrum. Note that the escape quanta result in a lower energy pedestal on the left side of the peak. This phenomenon impairs the detectability of lower energy peaks. The same simulation was repeated. This time the total number of scintillations was counted for each incident gamma particle. Individual incident gammas which resulted in less than a threshold number of scintillations have been rejected (vetoed). Note the disappearance of a low energy pedestal in the second simulation and the reduction of peak sensitivity. FIG. 7 shows normalized 2.6 Mev gamma energy spectrum comparisons between an NaI(Tl) detector and a detector of the type described above. FIG. 8 is a schematic block diagram of exemplary front end electronics 600 , for use with each elongate segments of FIGS. 4A and 4B . It is noted that the circuitry is symmetrical about the center of the center of the drawing. Only the upper half of the drawing is discussed. The upper signal line represents circuitry 602 for gain stabilization PMT voltage division and outputting 604 of signals from the upper PMT anode (PM 2 ). This signal is fed to a snap-off timing discriminator 606 and a delay circuit or delay line 608 , typically 15 nsec long. It is also fed to an adder 610 . The snap-off timing discriminator and timestamp circuitry are used to provide a timestamp representing the time of the leading edge of the signal. This value is saved to be used in the analysis described below with respect to FIG. 12 . The signals fed to the fast amplifier by the PMTs are added to provide a crude energy signal for the scintillation. The amplitude of this gives a rough measure of the amplitude of the signals in a scintillation range ID circuit, 616 . This measure is used to set a variable gain amplifier 612 with an appropriate gain, before the signal from the PMT has passed delay circuit 608 . An 8 bit flash ADC ( 614 ) is used to digitize the signal, preferably with a sampling rate of 1-2 nsec. The digitized signal (and its companion from the other PMT) is stored together with the time stamp. Thus for each PMT, an uncorrected intensity and timestamp are stored. The use of these stored values is described in conjunction with FIG. 12 . The circuits shown between the upper and lower lines could be replaced by a pair of 14 bit flash ADCs. However, the circuit shown is substantially less expensive. FIG. 9 illustrates a methodology for rejection of events which do not come through the front face of the detector, or alternatively for identifying and separating between the events that come through the front or rear faces. As was indicated above, it is possible to determine a statistically probable direction of incidence of a gamma ray. FIG. 9 further illustrates this method. Detector 104 , having a front face 202 and a back face 203 is shown with tracks 906 , 908 , 910 of scintillations caused by three incident gamma rays. While the probable direction of incidence of gammas associated with tracks 906 and 908 can only be estimated statistically, it is practically certain that the gamma ray that resulted in track 906 is incident from the front of the detector and that associated with track 908 is incident from the back of the detector. This is true for two reasons. First, the initial scintillation 907 of track 906 is nearer the front than the back face and the initial scintillation 909 of track 908 is nearer the back face. This provides a certain probability (depending on the mean free path of the gamma ray and the thickness of the detector) that the track resulting in 906 is caused by an incident ray passing through the front and the track resulting in 908 is caused by a ray passing through the back face. Thus, the sequence of scintillations or each track provides an indication of rear or front entry of the event. In addition, the direction determined from the initial path of the track shows a high probability of incidence from the front for track 906 and from the back for 908 . In embodiment of the invention, one or both of these factors (nearness and probable direction) are utilized to separate between gamma rays that enter from the front and those that enter from the back. Track 910 corresponds to a gamma ray that has a much lower number of scintillations than normal. This is preferably classified as an event that for which not all the energy is captured. Such scintillations are preferably ignored. FIG. 10 is a schematic illustration of a detection station 700 according to an embodiment of the invention in which a pair of partially collimated detectors 702 , 704 is used. As was indicated above, it is not possible, based on the detected scintillations alone, to accurately determine the direction of incidence of gammas, let alone neutrons, except for determining the detector side in which neutrons interacted. Detectors 702 and 704 have a portion 703 of the detector that is collimated by High Z collimator plates 706 and a portion 705 that has no collimators. In an embodiment of the invention the collimated portion is used for detection and imaging of gammas and the uncollimated portion is used for detection of gammas. The entire detector is used for the detection of neutrons, without imaging. Also shown on FIG. 10 is a pair of CCTV cameras 710 . These cameras are one example of how the velocity and position of the vehicle is determined and allow for the construction of a composite image based on scintillations detected over the entire time that the vehicle travels between the detectors in a coordinate system that moves with the vehicle. In addition, by correlating the detected gamma and neutron images determined from the detectors with the optical images from a CCTV camera or camera, the position of the suspected threat within the vehicle can be estimated and used to better access the probability of threat. As described in U.S. patent application Ser. No. 11/348,040, this can improve the system ROC. FIG. 11 illustrates an alternative detector 800 , in which collimation is provided, in accordance with embodiments of the invention. Detector 800 is characterized by having a different depth over different portions of the detector. This detector is meant to provide a trade-off between sensitivity and spatial resolution as well as between spatial and energy resolution. This corresponds to a trade-off between image based threat detection quality and other signatures detection quality. Consider first section 802 , which has less depth. However, the front face of this section is bounded by adjoining sections 804 . Sections 804 act as collimators for section 802 , since they absorb gamma rays and neutrons that do not arrive via angle β N . Thus, for sections 802 , the direction of captured neutrons in the direction shown is limited. For gammas the angle is smaller, and is reduced by optional collimator plates 806 to an angle β γ . Furthermore, collimators plates can be placed inside the cavities in the detector, parallel to the plane of the drawing. This will similarly limit the angle in the other direction for the gammas. Optionally, neutron absorbing OS material can be used instead of high z collimators to provide a measure of collimation in the other direction for neutrons. Now consider the second section 804 ; this section will have a lesser directivity a for gammas (and only gross directivity for neutrons), but, since the detector is deeper at this point, will have generally better energy selectivity for gamma rays. This is based on the expectation that more of the energy will be captured by making the detector thicker. α, β γ , and β N are typically of the order of 4, 1.2 and 2 meters, FWHM at a distance of two meters. It is understood that these values are a balance between image spatial resolution, particle capture efficiency and to a lesser degree, spectral selectivity (based mainly on a reduction of capture efficiency). FIGS. 12A-12E are simplified flow charts illustrating the methodology used to determine threats and their type, in accordance with an embodiment of the invention. FIG. 12A is an overall, simplified flow chart of a method 1200 . In the illustrated method, a plurality of signals from each PMT 212 is acquired, for example, using the circuitry of FIG. 8 . This acquisition is explained more fully below with reference to FIG. 12B . The individual PMT data is stored ( 1210 ) and signals are corrected and paired ( 1212 ) to reconstruct the characteristics of each scintillation event. This process is described more fully with respect to FIG. 12C . Data for each scintillation is stored ( 1220 ). The stored data is grouped by incident particles which are reconstructed and individually analyzed ( 1222 ). This process is described more fully with the aid of FIG. 12D . The individual particle data is then stored ( 1240 ). The incident particle data is analyzed to determine one or more “signatures” ( 1242 ) characteristic of SNM, RDD and NORM and/or their isotopes. This is discussed more fully with respect to FIG. 12E . Based on the individual signatures, a determination is as to whether a threat is present ( 1260 ). If a threat is identified with a high probability (e.g. >5σ), then an alarm is generated ( 1262 ). If multimodal analysis is available, then such analysis ( 1264 ), as described further below, is performed. If it is not available, then 1260 , 1262 are replaced by 1280 , 1282 , 1284 and 1286 , described immediately below. It should be noted that if multi-modal analysis is available, then it is usually performed before any alarm is sounded to verify the single modality determination and to reduce false alarms. After multi-modal analysis, (and more preferably a plurality of multi-mode analyses) a threat assessment ( 1280 ) is performed. If the multi-modal threat probability is above a certain threshold, then an alarm is generated ( 1282 ), If it is below a second, lower threshold, then the vehicle/object being tested is cleared ( 1284 ). If it is between the two thresholds, then the vehicle/package is sent for further manual or machine testing ( 1286 ). Returning to 1202 , reference is made to FIG. 12B , which is a simplified flow chart of the processes of single PMT signal acquisition. At 1204 the signal is identified as a signal and given a time stamp. The signal is acquired ( 1206 ) and digitized ( 1208 ). In an embodiment of the invention, the circuitry of FIG. 8 is used to acquire the signals. Returning to 1212 , reference is made to FIG. 12C , which is a simplified block diagram of the process of reconstructing the characteristics of individual scintillations from the separate signals of the PMTs. The data in the PMT raw database is corrected in accordance with the correction factors described above. The time stamp is corrected ( 1214 ) for each scintillation, according to the time delay correction described above. Then, the PMT signals are paired ( 1215 ) and associated with a given detector based on the time stamp (i.e., the signals have a time stamp within the maximum corrected time for signals from PMTs of the same segment). The energy signal (sum of the energy deposited signals indicated by each PMT) of the signals preferably corrected by the loci dependent light correction efficiency correction described above is determined ( 1216 ) and identified as the energy signal of the scintillation. The position of the scintillation, along the length of the segment is determined ( 1217 ) based on the one or both of the energy difference between the paired PMT signals or the difference between their corrected time stamps (difference between TOFs). In addition, the determination of whether the scintillation is caused by an interaction with a γ or a neutron, is optionally determined ( 1218 ) by the decay time constants or shape difference of the signals. It is well known in the art that in OS, the neutron caused scintillation decay is substantially longer than that caused by a gamma. The information on the scintillations is sent for storage ( 1220 , FIG. 12A ) in a scintillation database. Returning to 1222 , FIG. 12D is a simplified block diagram of the process of single incident particle analysis and reconstruction. First, the scintillations are grouped ( 1221 ) in accordance with their time stamps as scintillations that are generated by a single incident gamma or neutron. In practice, all scintillations that occur with a window of −10 nsec and +20 nsec of the “first” scintillation are considered as part of the same group, so long as they are geometrically close (e.g., closer than 1 meter apart). Since the time between incident particles is much larger than the time between scintillations, there is only a small chance of overlap of scintillations from different incident particles. In the event that there is such overlap, this in itself could be indicative of a cascaded event, spontaneous fission salvo or an RDD or of a very large unshielded source. Once the scintillations have been grouped, the total energy ( 1232 ) transferred from the incoming event can be determined by summing the individual energy signals of the scintillations in the group. Separately from the energy determination, the scintillations are sequenced ( 1223 ) based on their corrected time stamps. A time stamp for the incident radiation is determined as the first of the sequence of scintillations ( 1224 ) and its position of incidence is determined ( 1225 ) from the position along the segment as described above (for y) and by the segment in which it appears (x,z). The sequence is optionally traced ( 1226 ) through the detector to determine its path. This path is optionally used to determine ( 1227 ) a gross direction of incidence. Depending on the energy, this gross direction can be used for rejecting ( 1228 , 1229 ) events that are from terrestrial or sky sources and those that enter the detector from the sides other than the front face. For higher energy gamma, for which the scatter is relatively low, the gross direction becomes sharper and may be useful for imaging as well. Alternatively or additionally where collimation is available, a direction of incidence can be derived for one or both of gammas and neutrons, depending on the type and configuration of the collimation as described above. Furthermore, using the principles described above, with respect to FIG. 9 , some of the events can be classified as having escape quanta ( 1230 ) and rejected ( 1231 ). The particle is then characterized ( 1233 ) by (1) its time of incidence; (2) its x, y incident coordinates; (3) its direction of incidence, if available; (4) whether it is a neutron or an gamma; and (5) its energy (if a gamma). This information is sent to 1240 for storage. Returning to 1240 , FIG. 12E is a simplified block diagram of actions performed in single modality threat detection. It is noted that different detector configurations are generally needed for optimizing these single modalities. For example, if collimation is used, the event capture efficiency is reduced and the gamma spectroscopy and coincidence (doublet, triplet and γ/N coincidence) signature detection are degraded. On the other hand, when collimation is used the ability to determine where the threat is in the vehicle and whether it is a small source (and thus more probably an SNM or RDD) is enhanced. Thus, it may be useful to have more than one detector each with different capabilities. A second detector can be used to screen all of the vehicles/packages or only those that look suspicious when they pass the first detector. First, information on reconstructed events that are stored is retrieved ( 1243 ). To the extent possible (depending on the detector capabilities) related events (for example gammas with a same energy or neutrons) are optionally imaged ( 1244 ). Using the information that is stored in 1240 the following signature/analyses are possible: doublet/triplet coincidence ( 1245 ); gamma spectroscopy isotope ID (with or without imaging and on the entire detector or vehicle or only in the area of a possible threat) ( 1246 ); image based NORM ID to identify the NORM signature ( 1247 ); SNM-RDD “point” source ID (based on the understanding that threats are generally less than 0.5 meters in extent) ( 1248 ); neutron counting/imaging ( 1250 ); and spontaneous fission γ/N ID, based on the temporal coincidence of a gamma and/or neutron events ( 1251 ). When a modality produces an image, then this image can be superimposed on an optical image of the vehicle ( 1252 ). All of the generated analyses are sent to a single modality alarm ( 1260 ) which compares the level of the individual threats probability and determines if an alarm should be generated based on only a singe threat. Appropriate ones of these single modality analyses are subject to multi-modal analysis 1264 . It is well known in the art of statistics (and in particular in threat analysis) that probability of detection false alarm or overlooked threat rates can be significantly reduced when information from orthogonal sources (or semi-orthogonal sources) are available. Any of the techniques available in the art would appear to be suitable for the present multi-modal analysis. Some of the multimodal analyses include: image guided gamma spectroscopic SNM-RDD ID; combined Neutron counting and gamma spectroscopy ID; doublet detection and Gamma Spectroscopy SNM-RDD-NORM ID; doublet detection and imaging SNM-RDD-NORM ID; and fused nuclear and gamma imaging. FIG. 13 shows a system 1000 , in which additional detectors are used to improve capture efficiency. In system 1000 , five detectors 1002 , 1004 , 1006 , 1008 and 1010 are used. As can be seen the additional detectors increase the solid angle subtended by the source. Alternatively to providing five detectors, three detectors (detectors 104 and 108 are omitted and the other detectors are extended to close the gap); four detectors (one detector on each side, one above and one below the vehicle); or eight detectors (an arrangement of three detectors beneath the vehicle similar to that shown in FIG. 14 above the vehicle), may be provided. Other variations of placement will be apparent to the person of skill in the art. These detectors can provide axial tomography and/or linear tomography to better detect threat “point” sources. FIG. 14 , shows a multi-lane system 1100 , in which a same detector is used for adjoining lanes. As indicated above, one detector is needed between two lanes, since the detector can discriminate between incident events which come from different directions. Thus, only N+1 detectors are required for a multi-lane checkpoint portal having N lanes. It should be noted that while the invention is described herein as using at least two detectors, in some embodiments of the invention, a single detector can be used, with reduced sensitivity/efficiency. Alternatively, more than two detectors can be placed around the path of the vehicle, such as top, bottom and two sides. Such detectors can not only improve SNM-RDD detection sensitivity but can also shield against environmental and foreign background radiation, resulting in further improved ROC. While the preferred OS is a liquid OS, in some embodiments of the invention a plastic OS, such as PVT can be used. Although the detectors are described in the context of passive detection of nuclear threats, in some embodiments of the invention, the large detector is used as a gamma and/or neutron detector of active portals. Although the detectors are described in the context of threat detection of SNM-RDD devices and radioactive materials carried on vehicles, in some embodiments the large OS detectors are used to screen supply chain articles (e.g. containers, pallets, air cargo, mail bags, etc.) While described explicitly, corrections known in the art, such as background correction, can be applied in portals using detectors of the present invention. In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb. The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the present invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments will occur to persons of the art. The scope of the invention is limited only by the following claims.

A detector for detecting radiation, the detector comprising: a plurality of elongate scintillator segments arranged in a side by side array; and at least one pair of light sensors optically coupled to ends of each of the elongate scintillator such that they receive light from scintillations produced in the scintillator and generate electrical signals responsive thereto.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 10/957,240 filed Oct. 1, 2004 now U.S. Pat No. 7,246,668. Further, this application claims benefit of U.S. provisional patent application Ser. No. 60/664,487 filed Mar. 23, 2005, which is herein incorporated by reference. Each of the aforementioned related patent applications are herein incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention Embodiments of the present invention generally relate to safety valves. More particularly, embodiments of the present invention pertain to subsurface safety valves configured to actuate using wellbore pressure in the event of an unexpected pressure drop. More particularly still, embodiments of the present invention pertain to the further ability to control the safety valves from the surface. 2. Description of the Related Art Subsurface safety valves are commonly used to shut-in oil and gas wells. The safety valves are typically fitted in a string of production tubing installed in a hydrocarbon producing well. The safety valves are configured to selectively seal fluid flow through the production tubing to control the flow of formation fluids upwardly should a failure or hazardous condition occur at the well surface. Typically, subsurface safety valves are rigidly connected to the production tubing and may be installed and retrieved by known conveyance methods, such as tubing or wireline. During normal production, safety valves are maintained in an open position by the application of hydraulic fluid pressure transmitted to an actuating mechanism. The actuating mechanism in such embodiments may be charged by application of hydraulic pressure through hydraulic control systems. Hydraulic control systems may comprise a clean oil supplied from a surface fluid reservoir through a control line. A pump at the surface delivers regulated hydraulic fluid under pressure from the surface to the actuating mechanism through the control line. The control line resides within the annular region between the production tubing and the surrounding well casing. In the event of a failure or hazardous condition at the well surface, fluid communication between the surface reservoir and the control line is interrupted. This, in turn, breaks the application of hydraulic pressure against the actuating mechanism. The actuating mechanism recedes within the valve, allowing a flapper to quickly and forcefully close against a corresponding annular seat—resulting in shutoff of the flow of production fluid. In many cases, the flapper can be reopened (and production flow resumed) by restoring the hydraulic fluid pressure to the actuating mechanism of the safety valve via the control lines. For safety reasons, most surface controlled subsurface safety valves (such as the ones described above) are “normally closed” valves, i.e., the valves are in the closed position when the hydraulic pressure in the control lines is not present. The hydraulic pressure typically works against a powerful spring and/or gas charge acting through a piston. In many commercially available valve systems, the power spring is overcome by hydraulic pressure acting against the piston, producing axial movement of the piston. The piston, in turn, acts against an elongated “flow tube.” In this manner, the actuating mechanism is a hydraulically actuated and axially movable piston that acts against the flow tube to move it downward within the tubing and across the flapper. These safety valves require a control system for operation from the surface in order to open the valve and produce. Safety valves employing control lines, as described above, have been implemented successfully for standard depth wells with reservoir pressures that are less than 15,000 psi. However, wells are being drilled deeper, and the operating pressures are increasing correspondingly. For instance, formation pressures within wells developed in some new reservoirs are approaching 30,000 psi. In such downhole environments, conventional safety valves utilizing control lines are not operable because of the pressure limitations of the control line. In other words, high-pressure wells have exceeded the capability of many existing control systems. Therefore, a need exists for a subsurface safety valve that is equipped with a self contained control system without control lines conveying hydraulic fluid to an actuating mechanism. A further need exists for a subsurface safety valve that is suitable for use in high pressure environments. There is yet a further need for the ability to reopen the safety valve remotely from the surface of the well. There is a further need for the ability to close the safety valve from the surface. SUMMARY OF THE INVENTION The present invention generally can be a wireline or a tubing safety valve which can be operated from the surface of the well. The present invention generally provides a method and apparatus for selectively sealing a bore. The tubular valve generally includes a closing member for seating in and closing the bore, and a pressure-actuated, retention member having first and second opposed piston surfaces opening and closing the valve. The tubular valve prevents sudden loss of pressure in the tubular and is controllable from the surface. In one embodiment the invention is a downhole valve for selectively sealing a bore. The valve includes a closing member for sealing the bore, a retention member having first and second piston surfaces for initially holding the closing member in an open position, a pressure chamber for applying pressure to the second piston surface, and a control line in communication with the pressure chamber. In another embodiment the invention is a method of operating a downhole valve. The method includes providing the valve in a downhole tubular, the valve having: a closing member for sealing a bore, a retention member having a first and second piston surface, mechanically biased to interfere with a closing member normally keeping the valve open, a pressure chamber in communication with the second piston surface and a control line in communication with the pressure chamber. The method further includes applying a wellbore pressure to the first piston surface and increasing the pressure in the pressure chamber to a level sufficient to overcome the mechanical bias of the retention member, but insufficient to overcome both the pressure on the first piston surface and the mechanical bias. In yet another embodiment the invention is a downhole valve. The valve includes a flapper mechanically biased to seal a bore, a retention member mechanically biased to interfere with the flapper to maintain the bore in the open position, a pressure chamber for controllably moving the retention member out of interference with the flapper, a control line for controlling the pressure chamber, and a bore pressure for applying a force to the retention member. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. FIG. 1 is a cross-sectional view of a wellbore illustrating a string of production tubing having a subsurface safety valve in accordance with one embodiment of the present invention. FIG. 2A is a cross-sectional view of the subsurface safety valve in an open position. FIG. 2B is a cross-sectional view of the subsurface safety valve of FIG. 2A , shown in the closed position. FIGS. 3A and 3B illustrate cross-sectional views of a subsurface safety valve in accordance with an alternative embodiment of the present invention. FIGS. 4A-4C illustrate cross-sectional views of a subsurface safety valve in accordance with yet another embodiment of the present invention. FIG. 5 is a chart illustrating the operation of the subsurface safety valve when an orifice design is used. FIG. 6 is a chart illustrating the operation of the subsurface safety valve with no orifice. DETAILED DESCRIPTION The apparatus and methods of the present invention allow for a safety valve for subsurface wells. Embodiments of the present invention provide safety valves that utilize normal wellbore pressure for actuation of the valve, which removes the need for hydraulic systems with control lines extending from the surface to the valve, however, a control system is incorporated into the invention for further control of the valve. FIG. 1 is a cross-sectional view of an illustrative wellbore 10 . The wellbore is completed with a string of production tubing 11 . The production tubing 11 defines an elongated bore through which servicing fluid may be pumped downward and production fluid may be pumped upward. The production tubing 11 includes a safety valve 200 in accordance with one embodiment of the present invention. The safety valve 200 controls the upward flow of production fluid through the production tubing 11 in the event of a sudden and unexpected pressure loss (also referred to herein as a “pressure drop”). The pressure drop may coincide with a corresponding increase in flow rate within the production tubing 11 . Such a condition could be due to the loss of flow control (i.e., a blowout) of the production fluid at the wellbore surface. In the event of such a condition, a subsurface safety valve, implemented according to embodiments of the current invention, automatically actuates and shuts off the upward flow of production fluid. Further, when flow control is regained at the surface, the safety valve is remotely reopened to reestablish the flow of production fluid. Further still, the safety valve is remotely closed or opened to shut off or reestablish flow of production fluid at any time through use of a control line 600 . Discussion of the components and operation of embodiments of the safety valve of the present invention are described below with reference to FIGS. 2A-2B , 3 A- 3 B, 4 A- 4 C, 5 and 6 . It should be understood, that as used herein, the term “production fluid” may represent both gases or liquids or a combination thereof. Those skilled in the art will recognize that production fluid is a generic term used in a number of contexts, but most commonly used to describe any fluid produced from a wellbore that is not a servicing (e.g., treatment) fluid. The characteristics and phase composition of a produced fluid vary and use of the term often implies an inexact or unknown composition. FIG. 2A illustrates a cross-sectional view of a subsurface safety valve in an open position, in accordance with one embodiment of the present invention. The safety valve 200 comprises an upper housing 201 A threadedly connected to a lower housing 201 B, which, in turn, is threadedly connected to a bottom sub 202 . The upper housing 201 A makes up the top of the safety valve 200 and extends upward. Accordingly, the bottom sub 202 makes up the bottom of the safety valve 200 and extends downward. Both the upper housing 201 A and the bottom sub 202 are configured with threads to facilitate connection to production tubing 11 (or other suitable downhole tubulars) above and below the safety valve 200 , respectively. The safety valve 200 comprises a flapper 203 and a flow tube 204 . The flapper 203 is rotationally attached by a pin 203 B to a flapper mount 203 C. The flapper 203 is mechanically or hydraulically biased toward the closed position. The flapper 203 pivots between an open position and a closed position in response to axial movement of the flow tube 204 . As shown in FIG. 2A , the flapper 203 is in the open position creating a fluid pathway through the bore of the flow tube 204 , thereby allowing the flow of fluid through the safety valve 200 . Conversely, in the closed position, the flapper 203 blocks the fluid pathway through the bore of the flow tube 204 , thereby preventing the flow of fluid through the valve 200 . As stated earlier, FIG. 2A illustrates the safety valve 200 in the open position. In the open position, the flow tube 204 physically interferes with and restricts the flapper 203 from closing. As will be described with reference to FIG. 2B , when the safety valve 200 is in the closed position, the flow tube 204 translates sufficiently upward to enable the flapper 203 to close completely and shut off flow of production fluid. While production fluid is conveyed to the surface under stable and controlled conditions, the safety valve 200 remains in the open position. Under such conditions, the flow tube 204 remains bottomed out against an upward facing internal shoulder 230 of the bottom sub 202 , thereby restricting the flapper 203 from closing. The flow tube 204 is held in this position due to a net downward force resulting from the force exerted by a spring 211 biased towards the extended position. A gap 231 between the inner diameter of the upper housing 201 A and the outer diameter of the flow tube 204 allows a piston surface 209 to be in fluid communication with the wellbore. As shown in FIG. 2A , a pressure chamber 205 is located in the annular space between the outer diameter of the flow tube 204 and the inner diameter of the lower housing 201 B. The pressure chamber 205 is bound by a piston seal 206 on top and the tube seal 207 on bottom. The pressure chamber 205 contains an opening 605 with a control line 600 attached to it. The control line 600 allows for adjustment of the pressure in the pressure chamber 205 from the surface. A spring 211 is also located in the annular area between lower housing 201 B and the flow tube 204 . The spring is held in place by a spring retainer 212 and surface 213 of the flow tube 204 . In one embodiment, during normal operation, while the valve 200 is in the open position, the pressure chamber 205 is filled with production fluid that enters the pressure chamber 205 through an orifice 208 . The orifice 208 meters flow that passes through it, regardless of whether the fluid is entering or exiting the pressure chamber 205 . While the valve 200 is in the open position, the fluid flow through the orifice 208 ensures that the pressure of the fluid inside the pressure chamber 205 , acting on surface 210 eventually equalizes with the pressure of the fluid flowing through the bore of the flow tube 204 and acting on the piston surface 209 . In the event of a catastrophic failure at the surface of the wellbore and loss of flow control, the safety valve 200 automatically closes, as seen in FIG. 2B . The loss of flow control typically means that production fluid is flowing upward at a flow rate that is much higher than normal. In keeping with Bernoulli's Rule, the pressure of production fluid flowing through the bore of the flow tube 204 is much lower than prior to loss of flow control. However, the pressure in the pressure chamber 205 is not reduced in unison with the production flow pressure. This is because the metering effect of the orifice 208 does not allow the fluid to flow out of the pressure chamber 205 to allow for the equalization process to occur immediately. Accordingly, for a particular time span, the pressure of the fluid flowing through the bore and acting on the piston surface 209 is appreciably lower than the pressure of fluid in the pressure chamber 205 acting on the surface 210 . The pressure difference between the fluid within the pressure chamber 205 and the production fluid results in the pressure chamber 205 increasing in volume and the flow tube 204 being urged upward. It should be noted that as the flow tube 204 moves upward, it meets resistance as the spring 211 is compressed. Provided that the pressure difference is large enough and the pressure chamber 205 expands sufficiently, the flow tube 204 travels sufficiently upward so that it no longer restricts the flapper 203 from closing as seen in FIG. 2B . Further, the safety valve 200 can close at any time through use of control line 600 . The control line 600 monitors and regulates the pressure in the pressure chamber 205 at the surface. To close the safety valve 200 the control line 600 increases the pressure in the pressure chamber 205 until the pressure acting on surface 210 is large enough to overcome the spring 211 force and the pressure acting on piston surface 209 . The control line 600 can further remove pressure from the pressure chamber 205 allowing the safety valve 200 to remain open if desired. Further, this control line 600 can be used to gather more volume for the pressure chamber 205 . The control line 600 monitors any volume changes in the pressure chamber 205 , allowing for better control of the safety valve 200 from the surface. In another embodiment, the orifice 208 is not present. Only the control line 600 can relieve the pressure in pressure chamber 205 . The pressure in the pressure chamber 205 increases from the static wellbore pressure and can be decreased as desired with the control line 600 . With the pressure in the pressure chamber 205 lower than that required to overcome the spring 211 force, the safety valve 200 remains open. In a normal producing well the production fluid pressure acts on surface 209 to act with the spring 211 force in order to keep the safety valve 200 open. An increase in the pressure chamber 205 pressure sufficient to overcome the spring 211 force, but insufficient to overcome the production fluid pressure acting on surface 209 and the spring 211 force will have no effect on the open safety valve 200 . If a sudden loss of production fluid pressure occurs in the production tubular the pressure inside the pressure chamber 205 forces the safety valve 200 closed as described above. In this embodiment, however the pressure chamber 205 will not automatically equalize with the production fluid pressure. In yet another embodiment, the orifice 208 described in the preceding paragraph, operates as a one way valve. The orifice 208 allows fluid from the bore to enter the pressure chamber 205 , but not exit. Thus, the pressure in the pressure chamber 205 equalizes with the wellbore pressure, if the control line 600 is not used. In the event of a sudden pressure loss, the flow tube 204 will move upward, allowing the flapper 203 to close, as described above. The pressure chamber 205 is controllable with the control line 600 , but is not necessary in order for operation of the valve 200 . After the flapper 203 closed, the pressure of the production fluid acting on the underside of the flapper 203 (pushing upward) is enough to forceably keep the flapper 203 in the closed position. In terms of the pressure chamber 205 , it should be noted if the orifice 208 is present the instant of the rapid pressure loss (corresponding to the loss of flow control) the metered flow of fluid through the orifice 208 allows for the pressure equalization process to resume. However, even after the pressure equalizes again, the pressure of the downhole fluid against the bottom-side of the flapper will keep it shut. Embodiments of the present invention also provide functionality to remotely reopen the subsurface safety valve 200 . Obviously, this would be done after the flow control apparatus at the surface of the wellbore is returned to working order. In order to reopen the safety valve 200 from the surface, fluid is pumped down to the safety valve 200 and the pressure is built up so that the pressure above the flapper 203 is the same as the pressure of the production fluid below the flapper 203 (i.e., pressure is equalized across the flapper 203 ). It should be noted that by this time, the flow of fluid through the orifice 208 has allowed pressure of fluid within the pressure chamber 205 to again equalize with the pressure of fluid outside the pressure chamber 205 . In an embodiment without the orifice 208 the system equalizes when desired by the operator. The spring 211 stays compressed, and the pressure chamber 205 does not return to its previous volume because the flow tube 204 is not allowed to move downwards due to the closed flapper 203 . However, once there is equal pressure on both sides of the flapper 203 , the spring 211 , biased towards the extended position, will urge the flow tube 204 downwards, which in turn will push the flapper 203 to the open position. Thereafter, the flow tube will bottom out against a corresponding internal shoulder 230 of the bottom sub 202 . With reference to the discussion above, it can be understood that the amount of upward movement of the flow tube 204 is dependent on the difference in pressure (i.e., “pressure drop”) between the fluid in the pressure chamber 205 and the pressure of the fluid flowing through the bore of the flow tube 204 at the moment of loss of flow control. In other words, the higher the difference in pressure between the fluid in the pressure chamber 205 and the fluid flowing through the bore of the flow tube 204 , the greater the amount of upward movement of the flow tube 204 . Maximizing upward movement of the flow tube 204 is important because it ensures that the flow tube 204 does not restrict the flapper 203 from fully closing in the event of a loss of flow control. Other embodiments of the present invention are envisioned for providing more upward movement of the flow tube for a given pressure drop. FIG. 3A , for instance, illustrates a cross-sectional view of a subsurface safety valve configured with bellows according to an alternative embodiment of the present invention. As will be described below, use of bellows for creating a pressure chamber is beneficial because bellows provide a large change in volume between the compressed and uncompressed position. Greater variance in the volume of the pressure chamber while the safety valve is in the open position versus closed position translates into more axial movement of the flow tube, which ensures complete closure of the flapper. Referring now to FIG. 3A , a safety valve 300 is provided with a housing 301 that is threadedly connected to a bottom sub 302 . Both the housing 301 and the bottom sub 302 are configured with threaded connections to allow for installing the safety valve 300 in a string of production tubing 11 . As with the embodiment described earlier, safety valve 300 comprises a flapper 303 and a flow tube 304 . The flapper 303 is rotationally attached by a pin 303 B to a flapper mount 303 C. The flapper 203 is mechanically or hydraulically biased toward the closed position. The flapper 303 pivots between an open position and a closed position in response to axial movement of the flow tube 304 . As shown in FIG. 3A , the safety valve 300 is in the open position; the flow tube 304 restricts the flapper 303 from pivoting. However, with sufficient upward movement of the flow tube 304 , the flapper 303 pivots to block the upward flow of production fluid. An important component of this embodiment is the use of bellows 306 for creating an expandable pressure chamber 305 . The bellows 306 may be made of a variety of materials, including, but not limited to metals. For one embodiment, the bellows 306 are configured with pleated metal to facilitate a volumetric variance between its compressed and uncompressed positions. The annular space between the bellows 306 and the flow tube 304 define the pressure chamber 305 . The pressure chamber 305 is bound on the top by the connection between the bellows 305 and the bellows retainer 307 . The lower end of the pressure chamber 305 is bound by a cap 320 . In one embodiment, there are two or more channels by which production fluid can enter the pressure chamber 305 : fluid can enter through opening 605 through which control line 600 passes, fluid can go past a packing 309 , or fluid can flow into the pressure chamber 305 via an orifice 308 . The control line 600 operates in the same manner as described above and can go through any part of the housing 301 so long as it is in fluid communication with the pressure chamber 305 . While the valve 300 is in the open position, the fluid flow through the orifice 308 and the packing 309 ensures that the pressure of the fluid inside the pressure chamber 305 is equalized with the pressure of the fluid flowing through the bore of the flow tube 304 . FIG. 3B provides a detailed view of the orifice 308 and the packing 309 . In the context of the current application, the packing 309 can be thought of as a one-way valve. As seen in FIG. 3A , the packing 309 is configured to allow fluid to flow into the pressure chamber 305 , but not out of it. An orifice 308 is also provided to allow for fluid to flow into the pressure chamber 305 . It should be noted that the orifice 308 and control line 600 provide the only paths by which fluid is allowed to flow out of the pressure chamber 305 . The orifice 308 meters the fluid that flows through at a relatively low flow rate. A pressure equalization port 321 extending through the cap 320 is provided to ensure that the pressure on either side of the cap 320 is equalized. Further, the port 321 provides a secondary path for production fluid to reach the packing 309 in the event that the path formed around the bottom end of the flow tube 304 and through the area adjacent to the flapper 303 is plugged. The safety valve 300 comprises a spring 311 that resists the upward movement of the bellows retainer 307 and the flow tube 304 . The bottom of the spring 311 rests against the bellows retainer 307 . The top portion of the spring 311 interfaces with a downward-facing internal shoulder of the housing 301 . In the open position of the safety valve 300 , with the flow tube 304 bottomed out, the spring 311 is fully extended. In the closed position of the safety valve 300 , with the flow tube 304 all the way up, the spring 311 is compressed and it exerts a downward force against the bellows retainer 307 . This embodiment operates the same as the previous embodiment. In the event of a loss of flow control at the surface of the wellbore, there would be a pressure drop between the fluid flowing through the bore of the flow tube 304 and the fluid in the pressure chamber 305 . As with the previous embodiment, the pressure in the pressure chamber 305 is not reduced in concert with the pressure of the production flow because the metering effect of the orifice 308 does not allow the fluid to flow out of the pressure chamber 305 to allow for pressure equalization to occur immediately. As a result, the pressure chamber 305 expands by extending the bellows 306 axially, which, in turn, urges the bellows retainer 307 and flow tube 304 to move upward, compressing the spring 311 . Upon sufficient upward movement of the flow tube 304 , the flapper 303 will close to shut-in the wellbore. Further, the safety valve 300 can be closed at any time through use of the control line 600 . The control line 600 monitors and regulates the pressure in the pressure chamber 305 at the surface. To close the safety valve 300 the control line 600 increases the pressure in the pressure chamber 305 which expands the bellows axially until the force acting on a bellow retainer 307 is large enough to overcome the spring 311 force and the pressure acting on a surface 319 . The control line 600 can further remove pressure from the pressure chamber 305 allowing the safety valve 300 to remain open if desired. Further, the control line 600 can be used to gather more volume for the pressure chamber 305 . The control line 600 can be used to monitor any volume changes in the pressure chamber 305 , allowing for better control of the safety valve 300 from the surface. In another embodiment, the orifice 308 is not present. The flow path past the packing 309 is optional. Without the flow path only the control line 600 controls the pressure in the pressure chamber 305 (described above). The pressure in the pressure chamber 305 increases and decreases as desired with the control line 600 . When the pressure in the pressure chamber 305 is lower than that required to overcome the spring 311 force, the safety valve 300 remains open. In a normal producing well the production fluid acts on surface 319 to act with the spring 311 force in order to keep the safety valve 300 open. An increase in the pressure chamber 305 pressure sufficient to overcome the spring 311 force but insufficient to overcome the production fluid pressure acting on surface 319 and the spring 311 force has no effect on the open safety valve. If a sudden loss of fluid pressure occurs in the production tubular the pressure inside the pressure chamber 305 forces the safety valve 300 closed as described above. In this embodiment, however the pressure chamber 305 will not automatically equalize with the production fluid pressure. In yet another embodiment the flow path past packing 309 is present without the orifice 308 . This allows fluid from the bore to enter the pressure chamber 305 , but not exit. Thus, the pressure in the pressure chamber 305 equalizes with the wellbore pressure, if the control line 600 is not used. In the event of a sudden pressure loss, the flow tube 304 will move upward allowing the flapper 303 to close, as described above. The pressure chamber 305 is controllable with the control line 600 , but it is not necessary in order for operation of the valve 300 . As with the embodiment described earlier with reference to FIGS. 2A and 2B , the valve can be reopened by equalizing pressure on both sides of the flapper 303 and allowing the spring 311 to urge the flow tube 304 downwards. This, in turn, would return the flapper 303 to the open position. FIG. 4A illustrates yet another embodiment of the present invention that is designed to provide additional axial movement of the flow tube for a given pressure drop. A cross-sectional view of a subsurface safety valve configured with extension rods sliding in their corresponding cylinders is provided. As will be described below, the axial movement of rods for expanding a pressure chamber is beneficial because the process of displacing rods in cylinders with fluid can yield a tremendous amount of axial movement of a flow tube for a given pressure drop. As stated earlier, complete upward movement of the flow tube ensures complete closure of the flapper. Referring now to FIG. 4A , a safety valve 400 has a housing 401 that is threadedly connected to a crossover sub 402 , which is threadedly connected to a lower housing 403 . The lower housing 403 connects to a bottom sub 423 . Both the housing 401 and the bottom sub 423 are configured with threaded connections to allow for installing the safety valve 400 in a string of production tubing 11 . As with previously described embodiments, the safety valve 400 includes a flow tube 404 , spring 411 and flapper 406 , which is rotationally attached by a pin 406 B to a flapper mount 406 C, each of which provides generally the same functionality as with other embodiments described above. The lower end 422 of the crossover sub 402 seals into the lower housing 403 . It should be understood that because the lower end 422 of the crossover sub 402 is sealingly connected (e.g., press fit, static seal, etc.) to the lower housing 403 , production fluid is not able to flow past the seal between the lower end 422 of the crossover sub 402 and the lower housing 403 . However, the lower end 422 of the crossover sub 402 does contain an orifice 408 that allows fluid to flow into and out of a pressure chamber 405 . Fluid arrives at the orifice 408 by flowing around the top or bottom of the flow tube 404 and within the annular space between the lower end 422 of the crossover sub 402 and flow tube 404 . The pressure chamber 405 is defined by the annular space between the lower housing 403 and the lower end of the crossover sub 402 . The pressure chamber 405 also includes the bores within the crossover sub 402 in which rods 420 are located. The pressure chamber 405 contains an opening 605 with a control line 600 attached to it. The control line 600 allows for adjustment of the pressure in the pressure chamber 405 from the surface. Fluid can flow into the pressure chamber 405 one or more ways: via the orifice 408 , and/or by flowing past rod packings 421 and through the control line 600 as described above. As with the packing 309 described with reference to the previous embodiment, rod packings 421 function as one-way valves, wherein fluid is allowed to flow into the pressure chamber 405 (downwards) past the rods 420 , but the fluid is not allowed to flow out from the pressure chamber 405 (upward) past the interface between the rods 420 and the rod packings 421 . FIG. 4B provides a detailed view of the interface between a rod 420 and a rod packing 421 . During normal operation, while the valve 400 is in the open position, the pressure chamber 405 is filled with the production fluid. While the valve 400 is in the open position, the fluid flow into the pressure chamber 405 ensures that the pressure of the fluid inside the chamber is equalized with the pressure of the fluid flowing through the bore of the flow tube 404 . In the event of a sudden pressure drop, as described in the previous embodiments, the fluid is not capable of immediately exiting the pressure chamber via the orifice 408 (for purposes of pressure equalization), so the pressure in pressure chamber 405 is higher than the pressure of the flowing production fluid. Consequently, the pressure chamber 405 expands and displaces the rods 420 upward from the cylinders. The rods 420 move the flow tube 404 upward against the spring 411 . After the flow tube 404 has moved sufficiently upward, the flapper 406 closes and shuts-in the well. Further, the safety valve 400 can close at any time through use of control line 600 . The control line 600 monitors and regulates the pressure in the pressure chamber 405 at the surface. To close the safety valve 400 the control line 600 increases the pressure in the pressure chamber 405 until the pressure acting on a surface 410 of the piston 420 is large enough to overcome the spring 411 force and the pressure acting on a surface 409 . The control line 600 can further remove pressure from the pressure chamber 405 allowing the safety valve 400 to remain open if desired. Further, this control line 600 can be used to gather more volume for the pressure chamber 405 . The control line 600 monitors any volume changes in the pressure chamber 405 , allowing for better control of the safety valve 400 from the surface. In another embodiment, the orifice 408 is not present. The flow path past the rod packings 421 is optional. Without the flow path only the control line 600 controls the pressure in the pressure chamber 405 (described above). The pressure in the pressure chamber 405 increases and decreases as desired with the control line 600 . With the pressure in the pressure chamber 405 is lower than that required to overcome the spring 411 force, the safety valve 400 remains open. If a sudden loss of fluid pressure occurs in the production tubular, the pressure inside the pressure chamber 405 forces the safety valve 400 to close as described above. In this embodiment, however, the pressure chamber 405 will not automatically equalize with the production fluid pressure. In yet another embodiment the flow path past rod packings 421 is present without the orifice 408 . This allows fluid from the bore to enter the pressure chamber 405 , but not exit. Thus, the pressure in the pressure chamber 405 equalizes with the wellbore pressure, if the control line 600 is not used. In the event of a sudden pressure loss the flow tube 404 will move upward, allowing the flapper 406 to close, as described above. The pressure chamber 405 is controllable with the control line 600 , but it is not necessary in order for operation of the valve 400 . It can be seen from FIG. 4C that the collective cross-sectional area of rods 420 is considerably less than the annular area between the inner diameter of the lower housing 403 and the lower end of the crossover sub 402 . Accordingly, the use of rods 420 in this manner requires less expansion of pressure chamber 405 to achieve the required amount of axial movement of the flow tube 404 to allow the flapper 403 to close. This is because the volumetric change of the pressure chamber 405 need only be enough to displace the volume of the rods 420 , rather than the entire annular area between the lower mandrel and the flow tube 404 . While three rods 420 are shown for the current embodiment, it should be understood that the number of rods can vary based on the requirements of a particular implementation. Those skilled in the art will recognize that safety valves according to embodiments of the present invention may be utilized in any wellbore implementation where a pressure differential (i.e. pressure drop) may arise. For instance, the safety valves described herein are fully functional if there is a pressure differential between fluid in the pressure chamber and fluid flowing through the bore of the safety valve, regardless of the absolute pressures of the respective fluids. Therefore, safety valves according to embodiments of the present invention may be utilized in low pressure wellbores as well as high pressure wellbores. While the exemplary safety valves described herein are configured for use with production tubing, those skilled in the art will acknowledge that embodiments of the present invention may be configured for use in a variety of wellbore implementations. For example, some embodiments of the present invention may be implemented as safety valves configured for use with wireline. Yet other embodiments may be configured for use with drill pipe or coiled tubing. FIG. 5 illustrates a chart for the operation of the safety valve 200 , 300 and 400 with use of the orifice 208 , 308 and 408 . As shown the solid line 700 represents the flowing wellbore pressure. The upper dashed line 710 represents the pressure in the pressure chamber 205 , 305 and 405 , and the distance between the upper dashed line 710 and the lower dashed line 720 represents the pressure drop required in the wellbore to close the valve 200 , 300 and 400 . As can be seen as the wellbore pressure decreases naturally the pressure in the pressure chamber 205 , 305 and 405 also decreases, which enables the valve 200 , 300 and 400 to remain open. If a sudden drop in wellbore pressure occurs as shown by the solid line branch 730 the valve 200 , 300 and 400 closes upon the line reaching the pressure of the lower dashed line 720 . If need be, the pressure in the pressure chamber can increase or decrease with the control line and the valve 200 , 300 and 400 could be closed or remain open. FIG. 6 illustrates a chart for the operation of the safety valve 200 , 300 , and 400 without use of the orifice 208 , 308 , and 408 . As shown the solid line 800 represents the natural wellbore pressure. The upper dashed line 810 represents the pressure in the pressure chamber 205 , 305 , and 405 , and the distance between the upper dashed line 810 and the lower dashed line 820 represents the pressure drop required in the wellbore to close the valve 200 , 300 , and 400 . As can be seen as the wellbore pressure decreases naturally the pressure in the pressure chamber 205 , 305 , and 405 remains constant. Therefore as the wellbore pressure naturally decreases the pressure required to overcome the spring 211 , 311 , and 411 and wellbore pressure decreases. In this case, a stronger spring 211 , 311 , and 411 may be required in order to ensure the valve 200 , 300 , and 400 does not close during normal operation. If a sudden drop in wellbore pressure occurs as shown by the solid line branch 830 the valve 200 , 300 , and 400 closes upon the line 830 reaching the pressure of the lower dashed line 820 . If need be, the pressure in the pressure chamber 205 , 305 , and 405 can increase or decrease with the control line 600 and the valve 200 , 300 , and 400 could be closed or remain open. While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

The present invention generally provides a method and apparatus for selectively sealing a bore. The tubular valve generally includes a closing member for seating in and closing the bore, and a pressure-actuated, retention member having first and second opposed piston surfaces opening and closing the valve. The tubular valve prevents sudden loss of pressure in the tubular and is controllable from the surface.

RELATED APPLICATIONS This application claims priority from Provisional Application No. 60/114,521 filed Dec. 31, 1999 and Provisional Application No. 60/135,894 filed May 26, 1999 both of which are herein incorporated by reference. FIELD OF THE INVENTION The present invention relates to a method and apparatus for providing electronic storage and retrieval of handwritten notes. More particularly, it relates to a method and apparatus for providing electronic storage and retrieval of handwritten notes, along with other drawings, in an electronic device such as a personal digital device (PDD). BACKGROUND Personal digital devices (“PDD”) have become extremely popular for recording, storing and retrieving information. Examples of PDDs include personal computers, such as laptop computers and handheld computer devices having a display area and an input area. In one version of a handheld computer device, a user inputs information in the input area by writing with a specialized pen. The pen does not mark on the input area, but the PDD converts the writing to electronic information through a resistive contact surface. According to a common version of a PDD, the user writes in a specialized manner to represent alpha-numeric characters. Movement of the pen on the resistive contact surface is recognized by the PDD and converted into a corresponding character. Each character is created at the same location on the resistive contact surface. The characters are then displayed in the display area of the PDD. Depending upon the operation of the PDD the characters are stored in various formats to record information, such as names, addresses, telephone numbers, appointments, and notes. The PDD can be connected to another electronic device, such as a personal computer, for exchanging information with the other device. While many PDDs are desirable because they are compact and portable, one drawback of typical prior art PDDs is that they use specialized writing systems that can be awkward to learn and may be hard for some users to master. Also, in typical prior art PDDs markings do not appear on the resistive contact surface during writing thereon. As a result, it can be difficult for users to track their writing portions to obtain the correct character, furthermore, non-character marks typically cannot be made or stored in prior art PDDs. Thus, drawings cannot be entered into the PDD. In addition, a PDD user typically enters characters one at a time, significantly limiting the speed with which one can take notes or record information. Therefore, a need exists for a PDD which allows users to write in a more fluid and familiar manner and to include noncharacters in their writing. In other words, a need exists for a PDD that records free-hand writing and/or drawing. Various devices have been developed to convert written documents into electronic forms in order to reduce storage space and retrieval time. For example, scanners can convert previously existing documents into an electronic format for storage and retrieval. In addition, a personal computer using certain software packages can allow a user to input data, e.g., to create an original document such as a drawing. The user can input data in a variety of ways, e.g., using a mouse on a desktop. The personal computer can display the original document on a screen. Furthermore, the personal computer can store the input data in memory or on a magnetic storage disk. Similarly, computers with touch screens and pads allow a user to create input data, e.g., to create an original document such as a handwritten note or a drawing, using a finger or stylus. Again, the computer can display the document on a screen and/or store it in an electronic format. However, creating an original document using one of these methods is somewhat awkward. The instrument used to mark on the touch screen or pad does not make a mark, and typically the user has to watch a separate display screen to observe what is recorded as a result of the writing motion. A. T. Cross of Lincoln R. I. has a product, sold under the name CROSSPAD, which converts handwritten documents into electronic form. The product includes a conventional notepad combined with a unique pen and printed circuit board assembly (“PCBA”) for the notepad. The user writes on the pad using the pen. The pen has an ink tip that can be used to make marks on the pad. The pen also includes a RF transmitter. The RF transmitter operates in conjunction with the PCBA for the pad to translate pen movement into electronic signals representing the user's writing motion. A switch in the pen turns the transmitter on when the pen is in contact with the pad. The switch is activated as a result of the force exerted by the pad on the tip of the pen. This system can be used to make electronic copies of handwritten notes. The electronic copies can then be stored and retrieved for later use. The user can write on the pad in an ordinary manner. However, a need remains for a system which allows storage, retrieval and searching of content in electronic copies of handwritten information. In addition, a need exists for a portable PDD system that allows for the creation, storage, searching, and retrieval of handwritten information. SUMMARY OF THE INVENTION An object of the present invention is to set forth a palm pad system that overcomes deficiencies and limitations of the prior art. In accordance with embodiments of the present invention, the palm pad system comprises an electronic notepad coupled to a conventional PDD. The electronic notepad and the PDD are retained in position on a common base. The electronic notepad includes an integrated printed circuit board having a plurality of etched loops formed thereon. The etched loops are uniformly distributed over the surface of the board and define an X-grid pattern and a Y-grid pattern. The X-grid pattern and Y-grid pattern are receptive to signals generated by a source, which source is positioned in close proximity to the grid patterns defined on the notepad. The electronic notepad further includes a paper-pad, which is securely mounted adjacent to the printed circuit board. The source for generating the signals can be an electromechanical transmitter, which transmitter is mounted in an elongated pen. The pen further includes a first end having a conventional retractable writing tip, such as a ball point pen tip, for marking on paper. The writing tip is coupled to the electromechanical transmitter via a micro-switch. The micro-switch is pressure actuated so that when the writing tip is pressed against a writing surface, such as the paper-pad, the transmitter coupled therewith is enabled for generating the signal. The signal is sensed by the X-grid pattern and the Y-grid pattern. The signal sensed by the X-grid pattern and the Y-grid pattern is further processed by electronics coupled therewith to determine the relative location of the writing tip with respect to the paper-pad. When a user composes handwritten data by moving the writing tip of the pen over the paper-pad, the relative locations of the writing tip are processed to concomitantly reproduce and electronically display the handwritten data on a display associated with the PDD. The electronically reproduced data can further be saved as an electronic file, which file can be retrieved at a later time. The pen further includes a cap having an aperture with a retractable non-writing tip mounted therein. When the cap is positioned over the writing tip, which is defined at the first end of the pen, the non-writing tip cooperates with the first end of the pen to force the non-writing tip into a retracted position defined in the cap. When the cap is positioned over a second end of the pen, the non-writing tip cooperates with the second end of the pen to force non-writing tip, which tip is defined in the cap, to extend outwardly from the aperture defined on the cap. In another embodiment, the palm pad system for enabling a user to electronically display, store, and retrieve hand written data comprises a means for converting handwritten data into an electronic file. The means for converting handwritten data into an electronic file is retained on a base. The palm pad system further comprises a means for receiving and processing the electronic file. The means for receiving and processing the electronic file is also retained on the base. The means for receiving and processing the electronic file is constructed and arranged to display, store, and retrieve the electronic file. In an embodiment, the means for receiving and processing the electronic file comprises a means for displaying the electronic file; a means for storing the electronic file; a means for retrieving the electronic file; and a control means for controlling the displaying, storing and retrieving of the electronic file. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects of this invention, the various features thereof, as well as the invention itself, may be more fully understood from the following description, when read together with the accompanying drawings in which: FIG. 1 ( a ) is a planar view of a palm pad system in accordance with one embodiment of the present invention; FIG. 1 ( b ) is a planar view of an integrated printed circuit board assembly included in the palm pad system shown in FIG. 1 ( a ); FIG. 2 ( a ) is an isometric view of the palm pad system shown in FIG. 1 ( a ); FIG. 2 ( b ) is a folded view of the palm pad system shown in FIG. 2 ( a ); FIG. 2 ( c ) is a side view of the palm pad system shown in FIG. 2 ( b ); FIG. 3 ( a ) is an isometric view of one embodiment of a pen, which is adapted to cooperate with the palm pad system of FIG. 1 ( a ); FIG. 3 ( b ) is a cross sectional view of the pen shown in FIG. 3 ( a ); FIG. 4 ( a ) is an isometric view of another embodiment of a pen, which is adapted to cooperate with the palm pad system of the present invention; FIG. 4 ( b ) is a cross sectional view of the pen shown in FIG. 4 ( a ); FIGS. 5 ( a ), 5 ( b ), 5 ( c ), and 5 ( d ) shows various views of a PDD integrated with a flip-down electronic notepad in accordance with another embodiment of the present invention; FIG. 6 is an isometric view laptop computer integrated with an electronic notepad; and FIG. 7 is a planar view of a fully integrated palm pad system. DETAILED DESCRIPTION In accordance with embodiments of the present invention, a portable palm pad system is set forth for enabling a user to electronically display, store, and retrieve hand written data. Referring to FIG. 1 ( a ), portable palm pad system 5 in accordance with one embodiment of the present invention comprises electronic notepad 10 coupled to a conventional PDD 15 . Palm pad system 5 further includes pen 200 , which is shown in FIGS. 3 and 4, and will be described in detail latter. Referring to FIG. 1 ( a ), one example of a conventional PDD 15 is a palm pilot, which is manufactured by 3COM. Electronic notepad 10 and PDD 15 coupled therewith are mounted on common base 20 . Generally, PDD 15 includes a microprocessor (not shown), memory (not shown), display area 25 and input area 30 . Display area 25 is typically comprised of a touch sensitive liquid crystal display (“LCD”) 25 a . Input area 30 typically has a number of control buttons 30 a , which a user can actuate, to enter or display data on LCD 25 a , conventional software, which is stored in the memory defined in PDD 15 , is executed to manage data entry or data displaying operations. One example of such software is IBM's INK MANAGER SOFTWARE, which provides note editing, searching, organization and sharing tools. The control buttons 30 A , LCD 25 a and software are all associated with the PDD 15 and are known to those of ordinary skill in the art. Referring further to FIGS. 1 ( a ) and 1 ( b ), electronic notepad 10 defined on palm pad system 5 includes integrated printed circuit board assembly (“PCBA”) 35 adapted to securely hold an ordinary paper-pad 40 thereon. Paper-pad 40 can be written on just like any other ordinary paper-pad. PCBA 35 includes a plurality of etched loops 36 formed thereon. Etched loops 36 are uniformly distributed over the surface of PCBA 35 and form an X-grid pattern (not shown) and a Y-grid pattern (not shown). The X-grid pattern and the Y-grid pattern are coupled with position determining electronics 21 . The PCBA 35 is powered parasitically through data bus 45 to PDD 15 . Of course, many other methods can be employed to provide power to PCBA 35 , including a separate power source. In an embodiment, the notepad includes four AAA batteries (not shown) that allow the notepad to operate for 3-4 months with moderate use. Electronic notepad 10 and PDD 15 are coupled through an interface 50 . According to an embodiment of the invention, interface 50 is a standard RS232 interface. As noted above, notepad 10 and PDD 15 can use a variety of communications technologies. PCBA 35 contained within notepad 10 transmits position and status information to PDD 15 through the interface 50 via data bus 45 . The position and status information can include separate X and Y coordinates of pen 200 (FIGS. 3 and 4 ), which is adapted to cooperate with notepad 10 , and the status of micro-switch (FIGS. 3 and 4) contained pen 200 (FIGS. 3 and 4 ). Furthermore, information directed to actuation of various controls 55 on notepad 10 can be communicated to PDD 15 . Although not shown in the drawings, other interfaces can be employed to form a communication channel between electronic notepad 10 and PDD 15 , for example, a substantially flat interface (not shown) can be integrated with the common base 20 . PDD 15 further includes software that operates to interpret the position and status information provided by PCBA 35 . The software converts the position and status information received from PCBA 35 into an electronic copy of markings or writings composed by a user on paper-pad 40 . The An electronic copy 24 of the markings or writings composed by the user can then be stored, retrieved and/or, as shown in FIG. 1 ( a ), displayed on PDD 15 , as with any other data received by the PDD. Alternatively, the notepad 10 , as shown in FIGS. 1 ( a ) and 1 ( b ), can include software or hardware 23 disposed therein for processing the position and status information to create electronic copies 24 of markings or writings composed on the pad by a user. Then, only electronic copies 24 would be transferred to PDD 15 for storage, retrieval and display. Referring to FIG. 2 ( a ), in an embodiment of the present invention, binder 20 includes PDD retaining surface 20 a and notepad retaining surface 20 b . Common base 20 can be formed of various materials including: leather, ballistic nylon and synthetics. PDD retaining surface 20 a and notepad retaining surface 20 b are coupled by a flexible section 20 c . Flap 60 defined on common base 20 substantially encloses and protects interface 50 (FIG. 1 ( a ), which enables communication between PDD 15 and notepad 10 via data bus 45 . Both PDD retaining surface 20 a and notepad retaining surface 20 b can be folded towards each other, which bends flexible section 20 c to orient the common base 20 into a folded position as shown in FIG. 2 ( b ). At least one tab 65 , with an appropriate closure mechanism can be used to hold common base 20 in the folded position as shown in FIG. 2 ( c ). FIG. 2 ( c ) further shows a set of loops 70 defined on flexible portion 20 c of common base 20 . When common base 20 is folded, loops 70 form a space 70 a . Space 70 a can accommodate a cylindrical object such as pen 200 (FIGS. 3 and 4 ). Common base 20 further includes an additional power supply retaining structure 75 adapted to retain batteries (not shown or other power supply in a secure position defined on common base 20 . FIGS. 3 ( a ) and 3 ( b ); 4 ( a ) and 4 ( b ) show embodiments of a pen 200 used in conjunction with embodiments of the present invention. U.S. Pat. No. 5,434,371, issued to Brooks and incorporated herein by reference, teaches a hand-held electronic writing implement including a writing tip for marking a surface and a pressure sensor located at the writing tip for emitting a pressure signal once the writing tip contacts the writing surface. Furthermore, U.S. Pat. No. 5,635,682 issued to Cherdak et al. and incorporated herein by reference, teaches a wireless stylus and disposable stylus cartridge for use with a pen computing device. The hand-held electronic writing implement set forth in U.S. Pat. No. 5,434,371 and the wireless stylus and disposable stylus cartridge set forth in U.S. Pat. No. 5,635,682 can be adapted for use with embodiments of the present invention. In an embodiment of the present invention, the pen 200 includes an ordinary writing tip 205 defined at a first end 206 of the pen, which writing tip 205 can write on paper pad 40 (FIG. 1 ( a ), and rubber tip 210 or non-writing tip which makes no marks. More specifically and referring to FIG. 1 ( a ) as well as to FIGS. 3 ( a ) and 3 ( b ), pen 200 includes body 215 and cap 220 . The body 215 houses ink supply 225 connected to writing tip 205 . Ink supply 225 and writing tip 205 can be comprised of many ordinary forms for pens, such as a replaceable cartridge with a ball point tip. Body 215 also houses electromechanical transmitter 230 . Transmitter 230 provides a signal used by notepad 10 to determine the status and position of pen 200 . The signal is frequency encoded to relay the status of writing tip 205 and a side switch (not shown). All frequencies are set within the frequency range of 335 to 500 kHz, and are assigned in a manner to allow enough tolerance to eliminate the need for tuning each pen 200 . The status of writing tip 205 is determined by micro switching mechanism 235 . Switching mechanism 235 is operable when writing tip 205 contacts paper pad 40 . The pressure of writing tip 205 on paper pad 40 is sufficient to activate switch 235 and transmitter 230 . Non-writing tip 210 is retractably mounted in cap 220 and is adapted for use with the touch sensitive display 25 a which is associated with PDD 15 . When cap 220 is positioned over writing tip 205 , non-writing tip 210 is retracted within cap 220 as shown in FIG. 3 ( b ). When cap 220 is positioned over second end 207 of pen 200 , which is defined diametrically opposite from writing tip 221 , second end 207 thereof cooperates with non-writing tip 210 to force non-writing tip 210 to extend outwardly from aperture 221 defined on cap 220 as shown in FIGS. 4 ( a ) and 4 ( b ). Therefore, when the user removes cap 220 from writing tip 205 to begin writing on notepad 10 , the user can also position cap 220 over second end 207 of pen to extend non-writing tip 210 outwardly from aperture 221 defined on cap 220 , which non-writing tip 210 can be used to operate touch sensitive display 25 a and/or control buttons 30 a (FIG. 1 ( a ) associated with PDD 15 . Pen 200 can include a single AAA battery 240 , which provides pen 200 with a 6 - 12 month average life. During use of writing tip 205 , writing tip 205 is pressed against paper-pad 40 for actuating micro-switch 235 to enable transmitter 230 to provide a signal. The signal provided by transmitter 230 is communicated to the etched loops 36 defined on PCBA 35 . The relative amplitudes of the received signals on individual etched loops 36 are used as inputs to algorithms (not shown) which determine writing tip's 205 relative location on paper-pad 40 . Therefore, when a user composes handwritten data by moving writing tip 205 of pen 200 over paper-pad 40 , the algorithms determine writing tip's 205 relative location on paper-pad 40 . The relative locations of writing tip 205 are further processed to concomitantly reproduce and electronically display the handwritten data on display 25 a associated with PDD 15 . The electronically reproduced data can further be saved as an electronic file, which file can be retrieved at a later time. More simply stated, a user's hand written notes, which are written on paper-pad 40 , are concomitantly displayed on touch sensitive display 25 a associated with PDD 15 . Thereafter, the user's handwritten notes can be electronically stored to and retrieved from memory which is associated with PDD 15 . FIGS. 5 ( a ), 5 ( b ), 5 ( c ), and 5 ( d ) show various views of another embodiment of palm pad system 5 b according to principles of the present invention. More specifically and referring to FIG. 5 ( a ), palm pad system 5 b includes a conventional PDD 15 b having a pivotal flip-down connection 17 to electronic notepad 10 b . A flexible data communication bus (not shown) connected between PDD 15 b and notepad 10 b enables data communication between PDD 15 b and notepad 10 b . FIG. 5 ( b ) is a side view of palm pad system 5 b . FIG. 5 ( c ) shows palm pad system 5 b in a closed position. FIG. 5 ( d ) is an isometric view of palm pad system 5 b positioned in a user's hand during use. Referring to FIG. 6, another embodiment of the present invention includes the integration of electronic notepad 10 c with laptop computer 300 . Electronic notepad 10 c can be coupled to a conventional processor (not shown) as well as conventional memory (not shown) contained within laptop computer 10 c . Such a configuration allows a user to take handwritten notes on electronic notepad 10 c and electronically store the notes in laptop computer 300 . Thereafter, the stored notes can be retrieved and displayed on a screen 310 associated with laptop computer 300 . Referring to FIG. 7, another embodiment of the present invention includes a fully integrated palm pad system 5 C. Integrated palm pad system 5 C includes a substantially rigid housing 400 containing electronic notepad 10 d and PDD 15 d . Electronic notepad 10 d is positioned adjacent to a first window defined on housing 400 and PDD 15 d is positioned adjacent to a second window defined on housing 400 . Although not shown in FIG. 7, the electronic notepad 10 d and PDD 15 d are coupled together by a data bus which operates in a similar manner as that previously described in earlier embodiments. The above described palm pad system 5 has many advantages over the prior art such as enabling handwritten notes to be converted into an electronic file or pages which can be stored and/or retrieved in the memory of PDD 15 . The electronic file can further be displayed on a touch sensitive display 25 a associated with PDD 15 . The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of the equivalency of the claims are therefore intended to be embraced therein.

A palm pad system including an electronic notepad coupled to a conventional personal digital device (“PDD”) via a data bus is set forth that enables a user to transpose handwritten data into electronic files or pages. The notepad and PDD are mounted onto a common base. The base includes a retaining structure for retaining the notepad on the base and another retaining structure for retaining the PDD on the base. The base further includes a flexible portion that permits the base to be folded into a compact form for protecting the notepad and PDD during transport. A pen containing a transmitter is employed by the palm pad system to transmit a signal to receptive electronics while a user writes data on the notepad with a writing tip contained in the pen. The signal received by the electronics is processed to generate an electronic file representative of the user's handwritten data. The electronic file can be electronically stored and retrieved. The electronic file can also be displayed on a touch sensitive display, which is associated with the PDD, immediately after composition by the user.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority of European application no.: 10189401.2 filed on Oct. 29, 2010 and European application no.: 101633182 filed on Dec. 1, 2010, the entire contents of both applications being hereby incorporated by reference herein. FIELD OF THE INVENTION The invention relates to a method for defining a search sequence for a soft-decision sphere decoding algorithm for use in receivers for quadrature amplitude modulation (QAM) communication signals. BACKGROUND OF THE INVENTION The system model of MIMO-OFDM systems using N T transmit and N R receive antennas can be described in the frequency domain for every OFDM subcarrier individually by the received signal vector y=[y 1 , . . . , y N R ] T , the N R ×N T channel matrix H, the transmitted symbol x=[x 1 , . . . , x N T ] T , and a disturbance vector n=[n 1 , . . . , n N R ] T which represents the thermal noise on the receive antennas. The following equation then describes the transmission model: y=H·x+n   (1). The elements of the transmitted symbol vector x are complex valued QAM symbols taken from a QAM modulation e.g. 4-QAM, 16-QAM, or 64-QAM. Depending on the modulation alphabet, every QAM symbol is associated to a number of transmitted bits N Bit , with N Bit = { 2 for ⁢ ⁢ 4 - Q ⁢ ⁢ A ⁢ ⁢ M 4 for ⁢ ⁢ 16 - Q ⁢ ⁢ A ⁢ ⁢ M 6 for ⁢ ⁢ 64 - Q ⁢ ⁢ A ⁢ ⁢ M The elements of the channel matrix h i,j are also complex valued. They are estimated by the receiver. At a certain stage of the signal processing chain the receiver computes softbits for every transmitted bit associated to the transmitted symbol vector x. Several methods are known for this purpose, with different error probabilities and different computational complexities. One near-optimal approach in terms of error probability is soft-decision sphere decoding. A soft-decision sphere decoder takes the received signal vector y and the channel matrix H as input and outputs a softbit (i.e. a likelihood value) for every bit associated to x. When denoting the bits associated to x j (the QAM symbols of the j-th transmit antenna) by [b j,1 , . . . , b j,n , . . . , b j,Nbit(j) ], a softbit ρ j,n is defined by the following Euclidean distances: d 0 , j , n 2 = min x 0 , j , n ⁢ {  y - H · x 0 , j , n  2 } ⁢ ⁢ d 1 , j , n 2 = min x 1 , j , n ⁢ {  y - H · x 1 , j , n  2 } ( 2 ) wherein d 0,j,n 2 and d 1,j,n 2 are the minimum Euclidean distances between the received signal vector y and all possible combinations of transmit symbols x, with the restriction that x 0,j,n represents all those combinations of x for which the n-th bit of the j-th transmit antenna is zero. On the other hand, x 1,j,n represents all those combinations of x for which the n-th bit of the j-th transmit antenna is one. The softbit for the n-th bit of the j-th transmit antenna is given by ρ j,n =d 0,j,n 2 −d 1,j,n 2   (3). A straight-forward algorithm would have to consider all combinations of x in the above equations in order to compute the softbits for one OFDM subcarrier. Since this approach is computationally very intensive and implies an exponential complexity, soft-decision sphere decoding algorithms have been proposed as a way to simplify the search. The simplification is achieved by QR decomposition of the channel matrix H followed by a tree search. QR decomposition decomposes the channel matrix H into a orthogonal rotation matrix Q and an upper triangular matrix R, such that H=Q·R. Since rotation by Q does not influence the Euclidean distances in the above equations, one can simplify the Euclidean distances d 0,j,n 2 and d 1,j,n 2 by d 0 , j , n 2 = min x 0 , j , n ⁢ {  y ′ - R · x 0 , j , n  2 } ⁢ ⁢ d 1 , j , n 2 = min x 1 , j , n ⁢ {  y ′ - R · x 1 , j , n  2 } ⁢ ⁢ with ⁢ ⁢ y ′ = Q H · y . ( 4 ) A second step of the sphere decoding algorithm is the tree search. The Euclidean distance from above, d 2 =∥y′−R·x∥ 2 , can be separated into partial Euclidean distances p 1 2 , . . . , p N T 2 as follows: d 2 =  ( y 1 ′ … y N T ′ ) - ( r 11 … r 1 ⁢ N T 0 … … 0 0 r N T ⁢ N T ) ⁢ ( x 1 … x N T )  2 = p 1 2 + … + p N T 2 ⁢ ⁢ with , ( 5 ) p N T 2 =  y N T ′ - r N T ⁢ N T · x N T  2 ⁢ ⁢ … ( 6 ) p 1 2 =  y 1 ′ - r 11 · x 1 - … - r 1 ⁢ N T · x N T  2 . ( 7 ) More generally, the partial Euclidean distances at a level k of a search tree are expressed as: p k 2 =  y k ′ - ∑ j = k N T ⁢ r kj · x j  2 . ( 8 ) The partial Euclidean distances separate the original Euclidean distance into N T portions. Due to the upper triangular structure of the R matrix, the partial Euclidean distances also separate the distance computation from the possibly transmitted QAM symbols x 1 , . . . , x N T such that p N T 2 only depends on the QAM symbol x N T , and is not dependent on x 1 , . . . , x N T −1. Also, p N T −1 2 only depends on x N T and x N T −1, and is not dependent on x 1 , . . . , x N T −2. This kind of dependency separation is utilized by the sphere decoding tree search in order to find the “closest” possible transmit symbol vector x min . The sphere decoding tree search assumes a maximum Euclidean distance d max 2 which is definitely smaller than the Euclidean distance of the “closest” transmit symbol vector x min . If now the search would start by choosing a candidate for x N T , the partial Euclidean distance p N T 2 is determined, in case of p N T 2 >d max 2 , all the Euclidean distances d 2 for all possible combinations of x 1 , . . . , x N T −1 (assuming the chosen x N T ) will also exceed the maximum search radius d max 2 . Therefore, the search can skip computing the partial Euclidean distance p 1 2 , . . . , p N T −1 2 , and can continue with another candidate for x N T . This search procedure can be illustrated as a tree search as depicted in FIG. 1 . The search tree consists of N T levels, that correspond to the QAM symbols of the different transmit antennas. In FIG. 1 N T =3 is assumed. Each tree node is associated to one possible QAM symbol x 1 , . . . , x N T . Therefore, the leave nodes of the tree represent all possible combinations of x. In the example above, with p N T 2 >d max 2 , after choosing a candidate for x N T , the complete sub-tree below the chosen x N T would be skipped during the sphere search. For finding the “closest” transmit symbol vector x, the maximum Euclidean distance d max 2 is initialized with ∞ (infinity). This means, that the partial Euclidean distances never exceed the limit, and that the sphere search reaches the bottom level after N T depth-first steps. The resulting Euclidean distance d 2 then provides an update of the maximum search distance d max 2 . The sphere search would now continue and try to update d max 2 if the bottom level of the tree is reached and if the resulting Euclidean distance would shrink d max 2 . The result of this search process is d max 2 being the Euclidean distance according to the “closest” possible symbol vector x min . If x min is restricted to certain bits being 0 or 1, the search tree can be adopted accordingly such that the search tree is built upon QAM symbols which meet the respective restrictions. FIG. 2 illustrates an improvement of the sphere search by ordering the sibling nodes at a tree level k by increasing partial Euclidean distances p k 2 . In a case where the maximum search distance d max 2 is exceeded at a tree level k (solid tree node) and the partial Euclidean distances p k 2 are not ordered, the search would continue with the next candidate node (the respective QAM symbol x k ) on the same level (arrow “A”). However, if the nodes in the tree are ordered by increasing p k 2 , the search can continue with the next node at level k−1 (arrow “B”). This is, permissible simply because due to the ordering of the sibling nodes the next candidate at the same level k would also exceed the maximum search distance d max 2 . In this case, the sub-tree which is skipped during the sphere search is much larger, and thus search complexity is much lower. It will be understood from the above that ordering of the sibling nodes by increasing partial Euclidean distances is essential for any efficient sphere decoding algorithm. Thus, a general task is to find a sequence of complex QAM symbols x i sorted by the partial Euclidean distance relative to a complex valued receive point z. For a 64-QAM, this means that at a search tree level k the ordering algorithm would have to sort all 64 QAM symbols according to the partial Euclidean distance p k 2 p k 2 =  z - r kk · x k  2 . ⁢ with ⁢ ⁢ z = y k ′ - ∑ j = k + 1 N T ⁢ r kj · x j . ( 9 ) This ordering algorithm would have to be performed for every parent node in the search tree which is visited during the sphere search, i.e. for all visited nodes of the search tree except those at tree level 1. Furthermore, for practical implementations the ordering algorithm has to be performed in parallel to the sphere search, therefore this algorithm has to output a “next ordered” node within every clock cycle. An object of the invention is to provide a low complexity method for determining a search sequence of nodes for a soft-decision sphere decoding algorithm. SUMMARY OF THE INVENTION According to the invention there is provided a method for defining a search sequence for a soft-decision sphere decoding algorithm for use in receivers for quadrature amplitude modulation (QAM) communication signals. The method comprises determining a first member of the search sequence by rounding a received symbol to a first constellation symbol of a plurality of constellation symbols which form a QAM constellation, said first constellation symbol being the constellation symbol closest to the received symbol, and determining the remaining members of the search sequence by (1) classifying, with a processing unit, the remaining constellation symbols of the QAM constellation into a plurality of sub-sets of constellation symbols having the same distance metric relative to said first constellation symbol according to a metric d sequ(n) =2a·n=max{|real(x c −x i )|,|imag(x c −x i )|}, wherein a is a scaling factor of the constellation grid, the constellation symbols being spaced by 2a in both horizontal and vertical directions, and ordering said sub-sets of constellation symbols in ascending order of their distance metric relative to the first constellation symbol, and (2) ordering the members of each sub-set of constellation symbols that are defined by the same distance metric according to their Euclidean distances. One or more aspects of the present invention are performed by a processing unit, including but not limited to, a processor or other device capable of performing the algorithm or steps thereof. The processing unit may be implemented in a receiver for QAM communication signals, or in a separate device connected to and/or associated with the receiver. The disclosed method is an approximate solution to the general task of ordering all QAM symbols of a specific constellation according to their partial Euclidean distances as expressed by (9), however, it is accurate enough for practical soft-decision sphere decoding. The computational complexity of the presented approach is much lower than it is for exact Euclidean distance ordering. The invention can be used for all sphere-decoding applications, in particular in MIMO-OFDM receiver implementations. In contrast to known ordering methods which use exact Euclidean distance ordering or look-up-table based approaches, the invention provides an efficient method for ordering the complex QAM symbols x i relative to a complex valued receive point z. The disclosed approach provides a solution for the stated problem with much lower computational complexity, since the multiplication required in (9) to compute the power of 2 is eliminated. Another advantage of the method according to the invention is that one ordered QAM symbol is output every clock cycle which means that the ordering can be applied in parallel to the sphere search since it does not require any pre-computation. Also, no look-up-tables are required for the ordering algorithm. BRIEF DESCRIPTION OF THE DRAWINGS Additional features and advantages of the present invention will be apparent from the following detailed description of specific embodiments which is given by way of example only and in which reference will be made to the accompanying drawings, wherein: FIG. 1 illustrates a tree search scheme; FIG. 2 illustrates an optimization of sphere search in the tree search scheme of FIG. 1 ; FIG. 3 shows a complex grid of a 64-QAM constellation; FIG. 4 shows an ordering sequence for a sub-set of QAM symbols defined by the same distance metric; and FIG. 5 shows two exemplary ordering sequences for two different received symbols. DETAILED DESCRIPTION The ordering method of the invention will now be described with reference to FIG. 3 and FIG. 4 . FIG. 3 shows the complex grid of a 64-QAM constellation. The QAM symbols x i are arranged on discrete real and imaginary positions ±a, . . . , ±7a, wherein a is a scaling factor depending on the application, i.e. the channel. A received symbol z is shown in the figure as an enlarged solid point. The proposed ordering algorithm starts with rounding z to the closest QAM symbol which is referred to as the center symbol x, below. Since the complex grid is discrete, this operation is very simple. The algorithm outputs the center symbol as the first ordered QAM symbol. The next member QAM symbols x i of the search sequence are defined using the following metric: d sequ(n) =2 a·n= max{|real( x c −x i )|,|imag( x c −x i )|}  (10). This metric defines a plurality of concentric squares around the center symbol x c , as illustrated in FIG. 3 which shows a small square for d sequ(1) =2a and a larger square with d sequ(2) =4a. Each of the metrics d sequ(n) , with n=1 . . . 7 for the case of a 64-QAM, defines a sub-set of constellation symbols. According to the invention, the next members of the search sequence are defined by ordering the constellation symbols according to the metric (10) in ascending order of their distance metrics relative to the center symbol x c and by ordering the members of each sub-set of constellation symbols that is defined by the same distance metric according to their Euclidean distances. For the exemplary received symbol z which is illustrated in FIG. 3 , the center symbol forms the first member of the search sequence, the 2 nd to 9 th members of the search sequence are defined by the small square, i.e. by d sequ(1) relative to the center symbol, the 10 th to 25 th members of the search sequence are defined by the large square, i.e. by d sequ(2) , the 26 th to 36 th members of the search sequence are defined by d sequ(3) , the 37 th to 49 th members of the search sequence are defined by d sequ(4) , and the 50 th to 64 th members of the search sequence are defined by d sequ(5) which gives a complete enumeration of the symbols of a 64 QAM constellation. It will be noted here that the ordering algorithm considers the constrained grid given by the QAM modulation. In other words, constellation symbols that are defined by a metric d sequ(n) do not necessarily form a complete square around the center symbol. Rather, square edges are ignored during the ordering process, as is the case for metrics d sequ(3) to d sequ(5) for the exemplary received symbol illustrated in FIG. 3 and received symbol z 1 of FIG. 5 , and also for metrics d sequ(1) to d sequ(7) relative to receive received symbol z 2 of FIG. 5 . The number of QAM symbols with the same distance metric shall be denoted by N d . In FIG. 3 , N d =8 for d sequ(1) =2a, and N d =16 for d sequ(2) =4a. A very important aspect for the accuracy of the ordering method of the invention is to order the N d QAM symbols with the same d sequ(n) according to their Euclidean distances. Simulations have shown that omitting an optimized ordering among the sub-set of QAM symbols that is defined by a specific d sequ(n) results in a significant performance decrease of the overall sphere decoding algorithm. FIG. 4 illustrates one exemplary embodiment of ordering the N d QAM symbols with the same d sequ(n) according to their Euclidean distances. The ordering sequence {0, 1, . . . , N d −1} is given by the annotation in FIG. 4 . It will be obvious from the figure that the constellation points identified by 0, 1, 2, and 3 have the smallest Euclidean distances from the center which forms the crossing point of a virtual pair of horizontal and vertical axes with “0” at the right end and “1” at the left end of the horizontal axis and “2” at the upper end and “3” at the lower end of the vertical axis. Also, it will be obvious from the figure that the constellation points in the corners have the largest Euclidean distances from the center. Accordingly, the first four QAM symbols {0, 1, 2, 3} of a sub-sequence which comprises the members of a sub-set of constellation symbols that is defined by a certain n of the distance metric d sequ(n) are those having the same real or imaginary coordinate as the center symbol. Therefore, the first four ordered QAM symbols are on a virtual pair of horizontal and vertical axes, respectively, which axes are in parallel with the coordinate axes of FIG. 3 and cross in the center symbol x c found by the rounding operation. In the exemplary embodiment of FIG. 4 , the next four ordered QAM symbols {4, 5, 6, 7} are given by rotating the horizontal and vertical axis by +1 symbol space (i.e. by 2a) of the member symbols of the sub-set of constellation symbols defined by d sequ(n) . {8, 9, 10, 11} is given by rotating the axis by −1 symbol space (i.e. by −2a). The next four ordered QAM symbols {12, 13, 14, 15} are given by rotation of the horizontal and vertical axis by +2 symbol spaces, the next four ordered QAM symbols {16, 17, 18, 19} are given by the reverse rotation by −2 symbol spaces. The last 4 ordered QAM symbols {N d −4, . . . , N d −1} are those residing in the square corners. It is equally possible to reverse the sense of rotation, i.e. first rotating the pair of horizontal and vertical axes clockwise to define QAM symbols {4, 5, 6, 7}, then counter-clockwise to define QAM symbols {8, 9, 10, 11}, then clockwise again, by two symbol spaces to define QAM symbols {12, 13, 14, 15} and so on. The sequence of constellation symbols as depicted in FIG. 4 is but one embodiment for ordering the member symbols of each sub-set of constellation symbols that are defined by the same distance metric. More generally, if the sub-set of constellation symbols defined by a certain n of the distance metric according to (10) forms a complete square around a center symbol, it comprises quadruplets of constellation symbols having the same Euclidean distance relative to this center symbol x c . Generally, according to the invention, these quadruplets are ordered into a sequence with ascending Euclidean distance of the quadruplets. When imagining a 2D coordinate system with the crossing point of the axes at x c , sets of constellation symbols having the same Euclidean distance relative to x c are defined by {(+2 an, +/− 2 am ),(−2 an,−/+ 2 am ),(−/+2 am,+ 2 an ),(+/−2 am,− 2 an )}  (11) for m=0 . . . n, as far as these points fall into the QAM constellation. Expression (11) gives a first quadruplet with the smallest Euclidean distance relative to the first constellation symbol (x c ) for m=0 at {(+2an,0), (−2an,0), (0,+2an), (0,−2an)}, i.e. including the symbols having the same real or imaginary coordinate as the first constellation symbol x c . Also, expression (11) gives a last quadruplet with the largest Euclidean distance relative to the first constellation symbol (x c ) for m=n at {(+2an,+2an), (−2an, −2an), (−2an,+2an), (+2an,−2an)}, i.e. including the symbols at the corners of the square defined by the same distance metric. Furthermore, expression (11) gives pairs of quadruplets with the same Euclidean distance relative to the first constellation symbol x c for m=1 . . . (n−1). However, in case the constellation symbols that are defined by a metric d sequ(n) with a specific n do not form a complete square due to the constraints of the grid given by the QAM modulation, there won't be quadruplets or pairs of quadruplets with the same Euclidean distance relative to the center symbol x c but sets of less than eight symbols having the same Euclidean distance. For example in FIG. 5 , d sequ(1) relative to receive symbol z 2 only defines three members that fall into the constellation, and d sequ(2) relative to receive symbol z 2 only defines five members that fall into the constellation. Among the three members defined by d sequ(1) , the symbols designated “2” and “3” form a set having the same Euclidean distance relative to the center symbol which is designated by “1”. Among the five members defined by d sequ(2) , the symbols designated “5” and “6” form a set having the same Euclidean distance relative to the center symbol “1”, and the symbols designated “7” and “8” form a set having the same Euclidean distance relative to the center symbol “1” and larger than that of symbols “5” and “6”. Generally, the ordering sequence among the quadruplets of QAM symbols can be any. To randomize and minimize the error introduced by the proposed approximation algorithm, it is however preferred to predefine a succession of these symbols and to maintain this succession for any quadruplet or pair of quadruplets throughout the algorithm. In the exemplary embodiment illustrated in FIG. 4 the same succession of symbols {east, west, north, south} is applied throughout the algorithm. FIG. 5 shows two exemplary ordering sequences for two different received symbols z 1 and z 2 using the exemplary ordering scheme of FIG. 4 . The disclosed ordering method provides an approximate solution for the task of defining a search sequence of QAM symbols for sphere decoding by ordering them according to increasing partial Euclidean distances during sphere decoding. Simulations have shown that the deviation of the search sequence ordering according to the invention from the exact Euclidean distance ordering is negligible for soft-decision sphere decoding.

A low complexity method for determining a search sequence of nodes for an efficient soft-decision sphere decoding algorithm for use in receivers for quadrature amplitude modulation (QAM) communication signals is achieved by determining a first member of the search sequence by rounding a received symbol (z) to a first constellation symbol (x c ) of the QAM constellation, classifying the remaining constellation symbols (x i ) of the QAM constellation into a plurality of sub-sets of constellation symbols having the same distance metric relative to said first constellation point (x c ) according to a metric d sequ(n) =2a·n=max{|real(x c −x i )|,|imag(x c −x i )|}, a being a scaling factor of the constellation grid, and ordering said sub-sets of constellation symbols in ascending order of their distance metric relative to the first constellation symbol (x c ), and ordering the members of each sub-set of constellation symbols that are defined by the same distance metric according to their Euclidean distances.

FIELD [0001] A stuffing box for a wellhead that is temperature conditioned. BACKGROUND [0002] A stuffing box is a packing gland chamber used to hold packing material compressed around a moving pump rod to reduce the escape of fluids from a well. Instead, the well fluids are directed to a production line. In cold temperatures, stuffing boxes may begin to leak well fluids, the grease or oil may become more viscous, and the well head may freeze. In warm temperatures, the lubricant is less viscous and therefore more difficult to control, which may result in the packing becoming brittle and fatigue more rapidly. SUMMARY [0003] There is provided a temperature conditioned stuffing box, comprising a housing having an outer surface, an inner surface defining a packing-receiving bore, a lower surface for attaching to a wellhead and an upper surface. A flow passage through the housing for passes temperature-conditioned fluid through the housing, the flow passage having an input and an output. BRIEF DESCRIPTION OF THE DRAWINGS [0004] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein: [0005] FIG. 1 is a side elevation view in section of a temperature conditioned stuffing box with containment. [0006] FIG. 2 is a side elevation view in section of a temperature conditioned stuffing box attached to a wellhead. [0007] FIG. 3 is a side elevation view in section of a temperature conditioned stuffing box without containment. [0008] FIG. 4 is a top plan view of a temperature conditioned stuffing box showing the containment cavity and vertical passages for the temperature conditioned housing. [0009] FIG. 5 is a partially transparent bottom plan view showing a passage of the temperature conditioned housing connecting two vertical passages. [0010] FIG. 6 is a perspective view of a flow path. DETAILED DESCRIPTION [0011] A temperature conditioned stuffing box generally identified by reference numeral 10 , will now be described with reference to FIG. 1 through 6 . [0012] Structure and Relationship of Parts: [0013] In cold temperatures, the stuffing boxes 10 tend to leak well fluids. Referring to FIG. 2 , it has been found that one of the causes of this leakage is that, as the packing gland 12 in a stuffing box 10 becomes cold, it does not compress around the polish rod 14 . In addition, in cold temperatures, the lubricant, such as grease or oil, may also be come stiff and less effective. Furthermore, most wells in cold weather will freeze at the wellhead 16 , including the stuffing box 10 . By using a temperature conditioned stuffing box 10 as described herein, this effect can be prevented, or at least reduced, resulting in less spillage and torn packing glands 12 in the stuffing box 10 . In warm temperatures, the stuffing boxes 10 also risk leaking as the lubricant becomes more difficult to control, resulting in more brittle packing that fatigues more rapidly. In both situations, a more moderate temperature may reduce the risk of leakage. [0014] FIG. 2 shows the temperature conditioned stuffing box housing 18 on a typical wellhead 16 , flanged above a flow-tee 22 of the wellhead 16 and the radigan blowout preventer 24 . Below that is the wellhead tubing bonnet 28 . Above the stuffing box 10 is a driver 30 that drives the polish rod 14 . While the driver 30 is shown to be a hydraulic cylinder, it will be understood that the stuffing box 10 may be adapted to be used with polish rods 14 that rotate or that reciprocate, and that the driver 30 may therefore be a drive head that rotates the polish rod 14 , or a pumping jack the reciprocates the rod vertically. [0015] As the drive head 30 or jack causes fluids to be pumped from the well, the fluids come up the well into the wellhead 16 , and exit through the flow-tee 22 . The packing glands 12 of the stuffing box 10 seal against the polish rod 14 to prevent fluid from flowing up through the stuffing box 10 . The stuffing box 10 is preferably provided with a lantern spring 32 to compress the packing 12 as it wears. A plate 36 is bolted over the spring 32 and the packing gland cavity 38 to enclose the packing. A cavity 38 is located at the top of the stuffing box 10 above the plate 36 that contains the packing 12 and where the polish rod 14 exits the packing glands 12 . The driver 30 or another plate 40 may be bolted on top to form a containment chamber 42 with the cavity 44 to contain any fluids that leak through the packing glands 12 . As the chamber 42 fills with fluid, it may be piped to a holding system 45 through a test cock 46 . [0016] Referring to FIG. 1 and FIG. 3 , the housing 18 of the stuffing box 10 is formed to have a “temperature conditioned housing”, with an input 48 and an output 50 for temperature conditioned fluid to flow through. Examples of heated fluids that are generally available on a well site include heated water, steam, hydraulic oil, engine coolant, etc. Examples of generally available cooling fluids include water, such as pumping water through the passages, etc. It will be understood that any suitable fluid may be used to heat or cool the housing 18 . The temperature-conditioned fluid may be used to maintain the packing gland 12 at a constant temperature or within a preferred temperature range. The housing 18 may be formed by casting, machining, or a combination of methods. Referring to FIG. 4 and FIG. 5 , the passages 52 in the housing are preferably made by machining, and connect the various passages 52 to create a flow path that flows around the packing glands 12 (not shown in these figures) in the body. This may be done by having a series of inputs 48 and outputs 50 that connect the passages 52 externally, or preferably, by sealing the holes at the surface of the housing 18 while leaving the adjacent channels 52 connected inside the housing 18 . The channels 52 may be formed vertically as well as horizontally to achieve a higher coverage. FIG. 5 shows a series of horizontal and vertical passages 52 that pass around the stuffing box 10 . Since the passages 52 are preferably made by machining from the surface, the outside of these passages 52 are filled or plugged to prevent fluid from escaping. An example of a completed flow path between input 48 and output 50 made up of various passages 52 is shown in FIG. 6 . It will be understood that other flow paths may be made using the principles discussed herein, which may or may not involve 90 degree corners as shown. [0017] There are different ways of controlling the temperature of the stuffing box 10 . Since the stuffing box 10 is able to operate in a range of temperatures, it is not always necessary to maintain a specific temperature, such as by using a thermostat, although it is possible to do so. Two main ways of controlling the temperature of stuffing box 10 are to control the temperature of the fluid entering housing 18 , and to control the flow rate of the fluid through housing 18 . For example, heated coolant from an engine, or heated hydraulic oil are readily available sources of heated fluid. However, it is generally easier to provide a flow control that restricts the amount of fluid that enters the housing than to control the temperature of the coolant or oil. [0018] In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. [0019] The following claims are to understood to include what is specifically illustrated and described above, what is conceptually equivalent, and what can be obviously substituted. Those skilled in the art will appreciate that various adaptations and modifications of the described embodiments can be configured without departing from the scope of the claims. The illustrated embodiments have been set forth only as examples and should not be taken as limiting the invention. It is to be understood that, within the scope of the following claims, the invention may be practiced other than as specifically illustrated and described.

A temperature conditioned stuffing box includes a housing having an outer surface, an inner surface defining a packing-receiving bore, a lower surface for attaching to a wellhead and an upper surface. A flow passage through the housing for passing temperature-conditioned fluid through the housing has an input and an output.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a waste disposal apparatus and, more particularly, to an apparatus particularly suited for the sanitary and odorless disposal of waste such as soiled diapers. 2. Description of the Related Art There are a number of systems for disposing of waste materials such as soiled diapers. The systems are often touted as a convenient way to dispose of such waste materials and reduce or eliminate any odor that may emanate from the materials. An example of such systems is U.S. Pat. No. 5,147,055 which discloses a diaper container that includes an activated charcoal filter to retain and absorb orders within the container. European patent application No. 0005660, the contents of which are incorporated by reference herein, describes a device for disposing kitchen refuse in packages enclosed by flexible tubing derived from a tubular pack of tubing surrounding a tubular guide. The device includes a tube sealing mechanism. The tubing passes from the pack over the top of and then down the guide to a position beneath the guide where it has been closed by fusion to provide a receptacle within the guide means. When this receptacle is full of refuse, a lever is manually operated to actuate an electromechanical apparatus including clamping and fusion devices that travel round closed tracks to perform the four-fold task of drawing the receptacle down below the tubular guide, fusing the tubing walls together to seal the top of the receptacle, sealing the tubing walls together to provide the closed base of the next receptacle and dividing the tubing by heat at a location between these two fusion locations to separate the filled package. There are a number of disadvantages with this device including the need for latches to prevent the wheels extending from the heating elements from inadvertently returning up the central track portions (as opposed to following the outer track portions as they should. A further disadvantage is that the heating element must be at least the width of the tube in order to seal the tube all the way across thereby preventing, for example, the escape of odors from the waste. Another device for use in disposing of diapers is disclosed in U.S. Pat. No. 6,370,847 to Jensen, et al., and U.S. Pat. No. 6,516,588 to Jensen, et al., the contents of which are incorporated by reference herein. The devices disclosed include tube sealing mechanisms. These related patents disclose a sealable diaper-disposal system that includes a container body 44 , a tubular core 63 in which flexible tubing 62 is stored, and a pair of heating elements 76 and 78 . The tubing 62 extends between two sealing members 76 and 78 that are operable to move toward each other to seal across the width of the tubing 62 and away from each other to allow the tubing 62 to be pushed into the lower portion of the container body 44 . A disadvantage of the Jensen system is that the soiled diaper must be pushed into the device beyond the tubular core 63 and the separated sealing members 76 and 78 so the sealing members can seal the tubing 62 to form a closed package with diaper enclosed. A further disadvantage is that the heating elements 76 and 78 must be at least the width of the tubing 62 in order to seal the tubing all the way across. Another popular approach to disposing of such diapers has been with a device using a tube twisting mechanism to form a pouch about the diaper. As an example, see the disclosures of U.S. Pat. Nos. 4,869,049, 5,590,512, 5,813,200, the contents of all of which are incorporated by reference herein. The U.S. Pat. No. 5,813,200 discloses a device for disposing of soiled diapers in twisted packages. The device has a container body with a hinged base, a hinged lid, and an upward cylinder secured within the container body. A tubular core rests on a portion of the upward cylinder to allow rotation there between. A flexible tube or sleeve rests on a portion of the tubular core with the tubing being circumferentially pleated as stored. Springs are fixed to the container and project radially inward to engage a package formed from the tube. The springs are equally spaced around the interior of the container to hold the package during the forming of a twist in the tube. The device disclosed in U.S. Pat. No. 5,813,200 is used to form a series of packages enclosing objects. The top of the flexible tubing is pulled upwards and tied into a knot. The closed end formed by the knot can then form the bottom of a package with the sidewalls formed by the tubing. The object is inserted and rests against the tubing near the knot. A rotatable interior lid is put into place and rotated such that the unused tubing and the tubular core rotate with respect to the package that is being formed. The package being formed does not rotate because it is held in place by friction between it and springs. Thus a package is formed between the knot and a first twist. Subsequently, objects are disposed and twisted in a like manner to form discrete packages with twists between them. Devices such as that disclosed in U.S. Pat. No. 5,813,200 are a convenient way of disposing of soiled diapers. A disadvantage of the system is that the twists between packages may become unraveled, thereby allowing groups of diapers to collect within the tubing, which makes emptying the container more difficult. Further, the twists do not create a continuous, complete seal and, therefore, may allow odor to escape from a package. Increasing the twists between packages may eliminate the above disadvantages, however, this requires the use of additional tubing. From the above it can be understood by those having ordinary skill in the art that there are a number of disadvantages associated with prior art waste disposal devices using flexible tubing to form packets for disposal of waste materials. It is clear that a device is needed that will eliminate the disadvantages described above. Such a device should be relatively economical to purchase and operate, ensure that the seals between packets are complete and cannot come undone, and be easy to operate. SUMMARY OF THE INVENTION The inventors of the present invention disclose a waste disposal apparatus including a container having a first end and a second end; a tubing cassette for supplying tubing, the tubing cassette mounted proximate the first end of the container; a first sealing member having ends and a second sealing member having ends, the first and second sealing members mounted to the container with their lengths in parallel relationship, positioned between the tubing cassette and the second end of the container, and moveable between an open position, wherein tubing from the tubing cassette can pass between the first and second sealing members, and a closed position, wherein the first and second sealing members can be activated to create a seal in the tubing; a first pair of guide pins each mounted to an end of the first sealing member and biased to move away from each other; a second pair of guide pins each mounted to an end of the second sealing member and biased to move away from each other; a first pair of channels between which the first sealing member is positioned and in each of which one of the first pair of guide pins travels as the first sealing member moves between the open position and the closed position; and a second pair of channels between which the second sealing member is positioned and in each of which one of the second pair of guide pins travels as the second sealing member moves between the open position and the closed position. The inventors further disclose a waste disposal apparatus including a container having a first end and a second end; a tubing cassette for dispensing tubing, the tubing cassette mounted proximate the first end of the container and rotatable in relation to the container, said dispensed tubing being operationally positioned with respect to the container such that a twist can be formed in the tubing to form a receptacle closed on a first end, into which waste material may be placed; a retention means positioned between the tubing cassette and the second end of the container for preventing rotation of a tubing receptacle filled with waste material when the tubing cassette is rotated; and a first sealing member and a second sealing member mounted to the container between the tubing cassette and the second end of the container and moveable between an open position, wherein tubing from the tubing cassette can pass between the first and second sealing means, and a closed position, wherein a twist formed in the tubing can be sealed. The inventors further disclose a method for disposing of waste material including the steps of providing a length of tubing having a first sealed portion of the tubing at a location along its length and an open end of the tubing; inserting waste material through the open end of the tubing until it contacts the first sealed portion of the tubing to form a waste package; retaining the waste package such that the waste package does not rotate in relation to the open end of the tubing; rotating the open end of the tubing such that a twist is formed in the tubing between the open end of the tubing and the waste package; and sealing at least a portion of the twisted tubing to form a second sealed portion. BRIEF DESCRIPTION OF THE FIGURES A more complete appreciation of the invention and the advantages thereof will be more readily apparent by reference to the detailed description of the preferred embodiments when considered in connection with the accompanying figures, wherein: FIG. 1 is a side elevation view of an apparatus for packaging waste in individual packages distributed along a length of flexible tubing; FIG. 2 is a perspective view of the sealing mechanism shown in FIG. 1 ; FIG. 3 is an exploded view of the sealing member housing and associated components shown in FIG. 2 ; FIG. 4 is a cross-sectional view of the sealing member housing and associated components shown in FIG. 2 ; FIG. 5 is a side elevation view of a tube sealing mechanism in a start/end position; FIG. 6 is a side elevation view of a tube sealing mechanism in a partially lowered position; FIG. 7 is a side elevation view of a tube sealing mechanism in a lowered position; FIG. 8 is a side elevation view of a tube sealing mechanism in a partially raised position; FIG. 9 is a side elevation view of a tube sealing mechanism in a raised position just after the heating elements meet; and FIG. 10 is a side elevation view similar to FIG. 1 , wherein an inner lid is rotated to twist one end of the flexible tubing material that contains waste prior to sealing the twisted area with a tube sealing mechanism. It is notable that similar items depicted in the figures may be given the same item number (e.g., all guide pins are identified with item number 42 , all stepped channels are identified with item 48 ), and similar items depicted in the figures that are not specifically numbered may be referred to by the same item number (e.g., all inner channels are referred to as item 94 ). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A waste disposal apparatus is disclosed for disposing of waste materials such as soiled diapers. The apparatus has improved features over prior art devices including, for example, tube twisting and sealing mechanisms that ensure the seals between packages are airtight, compact, and facilitates automation of the sealing process. Also disclosed are attributes that reduce the complexity of such mechanisms and reduce the cost to manufacture and assemble the same. Referring to FIG. 1 , an apparatus in accordance with an embodiment of line present invention is illustrated at 10 . The apparatus 10 includes a cylindrical container 12 having a removable cover 14 at the top of the cylindrical container 12 and an access door 15 at the bottom of the cylindrical container 12 . The removable cover 14 has an opening covered by a hinged lid 16 . The apparatus 10 further includes a tube twisting mechanism 18 and a tube sealing mechanism 20 . Specific embodiments these mechanisms arc described herein below, however, various other mechanisms that may be employed to obtain advantages (e.g., improved seals between waste packages, more economical heating element configuration) of the invention as discussed in detail herein. Exemplary tube twisting mechanisms are disclosed in U.S. Pat. No. 6,128,890 and U.S. Publication No. US 2002/0162304, the contents of all of which are incorporated by reference herein. Exemplary tube sealing mechanisms are disclosed in U.S. Pat. Nos. 6,065,272 and 6,370,847, the contents of all of which are incorporated by reference herein. Tube twisting mechanism 18 includes a channel-shaped flange 22 that is located inside of and fixed to the cylindrical container 12 , a tubing cassette 23 resting on the channel-shaped flange 22 , and an inner lid 28 mounted to the tubing cassette 23 . The tubing cassette 23 has a tubular core 24 and a continuous length of flexible tubing 26 stored in within the tubular core 24 . An exemplary tubing cassette is disclosed in U.S. Pat. No. 4,934,529, the contents of which are incorporated by reference herein. When the inner lid 28 is rotated it causes the tubing cassette 23 to rotate in relation to the channel-shaped flange 22 . Flexible tubing 26 is shown to extend from the top of the tubing cassette 23 , over the inner lid 28 , and through the center of the tubular core 24 of the tubing cassette 23 . Waste packages 29 are shown formed at the free end of the flexible tubing 26 within the cylindrical container 12 . A flat flange 30 extends from the cylindrical container 12 . A plurality of retention means, for example, retention springs 32 are attached to the flat flange 30 and retain or hold a waste package 29 stationary while the inner lid 28 is rotated to twist the flexible tubing 26 . As used herein, the term “retention means” shall include any retention device for retaining a waste package 29 stationary while the flexible tubing 26 is rotated. The term shall include, for example, retention devices as disclosed in U.S. Pat. Nos. 4,869,049, 5,590,512, 6,170,240, 6,128,890, 6,370,847, JP 592039015 (P2000-247401 A), and U.S. Patent Publication No. US 2002/0162304, the contents of all of which are incorporated by reference herein. Tube sealing mechanism 20 includes a sealing member housing 36 in which a first sealing member 38 and a second sealing member 40 are housed. As described in more detail herein below, the first and second sealing members' 38 and 40 are configured to heat a twist created in the tubing 26 by the tube twisting mechanism 18 . Guide pins 42 extend from the first and second sealing members 38 , 40 , protrude through longitudinal openings 44 in the sealing member housing 36 , protrude through the upper ends of guide links 46 , and engage with stepped channels 48 . The stepped channels 48 are formed in base plates 49 which are attached to the cylindrical container 12 . The lower end of the guide links 46 are pivotally attached by pivot pins 50 to the upper ends of pull bars 51 . The lower ends of the pull bars 48 are pivotally attached by pivot pins 52 to an actuation lever 54 , which is pivotally attached by one end to the cylindrical container 12 by pivot pins 56 and its other end extends through the sidewall of the cylindrical container 12 . A pedal 58 is attached to the end of actuation lever 54 that extends out of the cylindrical container 12 . Pneumatic spring cylinders 60 are connected between the sealing member housing 36 and the cylindrical container 12 . It is notable that the term “waste package” is used broadly herein to describe flexible tubing enclosing waste material and sealed on one end of the package (e.g., the “waste package” formed above the sealing member housing 36 with only one end of the package sealed), or flexible tubing enclosing waste material and sealed on both ends of the package (e.g., the “waste packages” 29 formed below the sealing member housing 36 with both ends of the package sealed). Referring to FIGS. 1 and 2 , in one embodiment of the invention the first sealing member 38 includes a heating element 62 and the second sealing member 40 includes a backing element 64 . Of course, the first and second sealing element may, in an alternative embodiment, both be heating elements. When the heating element 62 and backing element 64 are in contact, or the closed position, the heating element 62 is sufficiently pressed against the backing element 64 and energized so that a seal forms in the flexible tubing 26 . The sealing in the embodiments of FIGS. 1 and 2 is performed through thermal heating of the flexible tubing 26 , however, as would be understood by one of ordinary skill in the art, sealing may also be obtained by ultrasonic techniques, application of adhesive to the tubing, activation of adhesive in the tubing material, or other sealing techniques. The heating element 62 is powered through an electrical cord 66 attached to a transformer 68 through a timing switch 70 . The transformer 68 receives power from a standard 115 volt outlet through a standard electrical cord and plug 72 . Alternative power sources may be provided. A magnetically activated proximity switch 74 is mounted to the top of one of the base plates 49 . The proximity switch 74 is connected to the timing switch 70 for activating the switch 70 , which in turn activates the heating element 62 for a predetermined amount of time to seal the flexible tubing 26 . The proximity switch 74 is activated by a magnet 76 that is attached to the top of the sealing member housing 36 . Referring to FIG. 3 , an exploded view of the sealing member housing 36 of FIG. 2 and associated components is shown. The sealing member housing 36 of such embodiment includes an upper half 80 and a lower half 82 , which are fastened together with fasteners 84 . The first and second sealing members 38 , 40 , having length approximately equal to “L” (the width of the first and second sealing members 38 , 40 ) are slidingly assembled between the upper and lower halves 80 , 82 of the sealing member housing 36 . Springs 86 urge the guide pins 42 out of their mounting holes in the first and second sealing members 38 , 40 , and toward the bottoms of their respective stepped channels 48 . Springs 88 urge the first and second sealing members 38 , 40 toward each other. Referring to FIG. 4 , a cross-sectional view of the sealing member housing 36 and associated components is shown. The first and second sealing members 38 , 40 are urged toward each other by springs 88 , thereby causing heating element 62 to contact backing element 64 . Backing element 64 is also separately urged by springs 90 against heating element 62 . This arrangement enables more precise adjustment of pressure between the backing element 64 and the heating element 62 , and also compensates for tolerance inaccuracies between the components (e.g., tolerance inaccuracies between the stepped channels 48 ). Alternatively, heating element 62 can be separately urged by a spring (not shown) against backing element 64 (which may or may not be spring loaded) to provide the same advantages. Referring to FIG. 2 , the stepped channels 48 include ramps and steps to ensure that each pair of guide pins 42 mounted to the first and second sealing members 38 , 40 travel around the stepped channels 48 in the same direction. It should be readily apparent that all four of the stepped channels 48 include similar features. Considering one stepped channel 48 (the right-hand stepped channel in FIG. 2 ) and following the path that a guide pin 42 would travel during operation of the tube sealing mechanism 20 , an upper channel 92 has a relatively flat bottom and is about horizontal. When the tube sealing mechanism 20 is activated by a user (e.g., by stepping on pedal 58 , FIG. 1 ), the sealing member housing 36 is urged downward. Consequently, guide pin 42 follows an inner channel 94 downward. Inner channel 94 is tapered inward (i.e., toward the sealing member housing 36 ), thereby causing guide pin 42 to be pressed into the first sealing member 38 against the bias of spring 86 . The inner channel 94 intersects a lower channel 96 . The lower channel 96 is at about the same depth as the upper channel 92 , therefore a step 96 is formed between the inner channel 94 and the lower channel 98 . As the guide pin 42 travels over the step 98 , it snaps outwardly (i.e., away from the sealing member housing 36 ). When the sealing member housing 36 is allowed to travel upward (e.g., by releasing pedal 58 , FIG. 1 ), the guide pin 42 travels upwardly due to the bias of the pneumatic springs 60 against sealing member housing 36 . Because of the step 98 between inner channel 94 and lower channel 96 , and the angle of lower channel 96 , the guide pin 42 follows lower channel 96 to an outer channel 100 . Outer channel 100 is tapered inward (i.e., toward the sealing member housing 36 ), thereby causing guide pin 42 to be pressed into the first sealing member 38 against the bias of spring 86 . The outer channel 100 intersects the upper channel 92 . A step 102 is formed between the outer channel 100 and the upper channel 92 . As the guide pin 42 travels over the step 102 , it snaps outwardly (i.e., away from the sealing member housing 36 ). Thereafter springs 88 urge the first and second sealing members 38 , 40 toward each other. Guide pin 42 travels in upper channel 92 until it contacts the end of the channel (i.e., at the intersection of the upper channel 92 and the inner channel 94 ). Referring to FIGS. 5-9 , there is shown sequentially a sealing cycle embodiment of the invention. In such sealing cycle the flexible tubing 26 , any waste contained therein, and any waste package 29 attached thereto are pulled downwardly into the lower portion of cylindrical container 12 ; the first and second sealing members 38 , 40 are separated to move upwardly past the waste-filled flexible tubing 26 ; the first and second sealing members 38 , 40 are urged toward each other so the heating element 62 and backing element 64 are in contacting relationship; and the heating element is energized to seal the flexible tubing 26 , thereby forming a waste package 29 . Referring to FIG. 5 , there is shown yet another embodiment wherein the tube sealing mechanism 20 is in the start position. That is, sealing member housing 36 is shown in a start position, for example, a user has not pressed the pedal 58 downwardly, wherein the pneumatic springs 60 maintain the sealing member housing 36 in the upper position; the first and second sealing members 38 , 40 are urged toward each other by springs 88 ; the guide pins 42 are positioned in the stepped channels 48 at the intersection of the upper channels 92 and the inner channels 94 ; and the heating element 62 and backing element 64 grip a sealed portion of the flexible tubing 26 between a waste-filled portion of the flexible tubing 26 positioned above the heating element 62 and backing element 64 , and a waste package 29 positioned below the heating element 62 and backing element 64 . Referring to FIG. 6 , the tube sealing mechanism 20 is shown just after having been actuated, for example, by a user stepping on pedal 58 (FIG. 1 ). That is, the sealing member housing 36 is shown in a partially lowered position, wherein the pneumatic springs 60 are partially compressed; the first and second sealing members 38 , 40 are urged toward each other by springs 88 ; the guide pins 42 are positioned in the stepped channels 48 in inner channels 94 , partially pressed into the first sealing member 38 and the second sealing member 40 because of tapers in inner channels 94 ; the heating element 62 and backing element 64 grip a sealed portion of the flexible tubing 26 between the waste-filled portion of the flexible tubing 26 positioned above the heating element 62 and backing element 64 , and the waste package 29 positioned below the heating element 62 and backing element 64 ; and the flexible tubing 26 , waste contained therein, and waste package 29 attached thereto are pulled downwardly toward the lower portion of cylindrical container 12 . Referring to FIG. 7 , the tube sealing mechanism 20 is shown in a lowered position after having been fully actuated and released, for example, where a user pressed pedal 58 completely downwardly and just released the pedal 58 (FIG. 1 ). That is, the sealing member housing 36 is shown in a lowered position, wherein the pneumatic springs 60 are about fully compressed; the first and second sealing members 38 , 40 are separating because guide pins 42 are positioned in stepped channels 48 in lower channels 96 moving toward outer channels 100 due to the force exerted by pneumatic springs 60 . Note that guide pins 42 cannot move upwardly into inner channels 94 because of steps 98 (FIG. 2 ). Referring to FIG. 8 , the tube sealing mechanism 20 is shown in a partially raised position. That is, the sealing member housing 36 is shown in a partially raised position, wherein the pneumatic springs 60 are partially compressed and urging the sealing member housing 36 upwardly; the first and second sealing members 38 , 40 are separated from each other because the guide pins 42 are positioned in the stepped channels 48 in outer channels 100 , partially pressed into the first sealing member 38 and the second sealing member 40 because of the tapers in outer channels 100 ; and the first and second sealing members 38 , 40 are sufficiently separated to clear the waste-filled portion of the flexible tubing 26 . Referring to FIG. 9 , the tube sealing mechanism 20 is shown in a fully raised position. That is, the sealing member housing 36 is shown in a fully raised position, wherein the pneumatic springs 60 are fully extended, maintaining the sealing member housing 36 in the fully raised position; the first and second sealing members 38 , 40 are urged together by springs 88 because the guide pins 42 had passed over steps 102 in the stepped channel 48 and thereafter followed the upper channels 92 toward the intersection of the upper channels 92 and the inner channels 94 ; the heating element 62 and backing element 64 are in contact and press the upper end of the waste-filled portion of the flexible tubing 26 ; and the magnet 76 causes the proximity switch 74 to activate timing switch 70 to provide electrical power to the heating element 62 for a predetermined amount of time to seal the flexible tubing 26 . Once the timing switch 70 turns off, the heating element 62 will cool and the tube sealing mechanism is ready to begin another cycle. It should be readily apparent to those having ordinary skill in the art that other sealing cycles can be used. For example, the sealing member housing 36 can start in the lower position (e.g., wherein the guide pins 42 are positioned at the intersection of the inner channels 94 and the lower channels 96 ). In such case, the pneumatic springs 60 would be of the type to bias the sealing member housing 36 downward and the guide links 46 , pull bars 51 , and actuation lever 54 would be configured to cause the sealing member housing 36 upward. Referring to FIG. 10 , a side elevation view similar to FIG. 1 is shown, wherein a tube twisting mechanism 18 is used to twist flexible tubing 26 . That is, the inner lid 28 is rotated in direction “A” to twist the flexible tubing material 26 , thereby forming a waste package 29 prior to sealing the twisted area 110 with the tube sealing mechanism 20 . A significant advantage of twisting the flexible tubing 26 prior to sealing with the tube sealing mechanism 20 is that twisting makes it possible to use a substantially shorter heating element 62 and backing element 64 (i.e., substantially shorter than length “L”, FIG. 3 ) since the width of the area to be sealed is only as wide as the twisted area 110 . In addition, twisting the flexible tubing 26 prior to sealing eliminates the need to include a tube cutting mechanism, which have been found to get clogged after repeated use, since the waste packages 29 will lie more randomly in the lower portion of the cylindrical container 12 (the wide, flat seal made between waste packages 29 that have not been twisted tend to cause the packages 29 to stack up). Furthermore, by sealing the twisted areas 110 , the twisted areas will not untwist, thereby preventing the unwanted leaking of odors. Of course, it is not necessary to include a tube twisting mechanism 18 in the present invention. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims. For example, components in one figure can be combined with components shown in another figure.

The present invention discloses a waste disposal apparatus including a container having a first end and a second end. A tubing cassette for supplying tubing is mounted proximate the first end of the container. A first sealing member and a second sealing member are moveable between an open position, wherein tubing from the tubing cassette can pass between the first and second sealing members, and a closed position, wherein the first and second sealing members can be activated to create a seal in the tubing. The first and second sealing members are guided by guide pins that travel along stepped channels for moving the first and second sealing members between the open and closed positions, and for pulling the tubing and waste packages through the waste disposal apparatus.

The Goverment has rights in this invention pursuant to Contract No. F08635-82-C-0001 awarded by the Department of the Air Force. TECHNICAL FIELD This invention is directed to a system which is active on a missile before the firing of its rocket motor and which senses heat around the missile which might ignite the rocket motor. When such heat is sensed, the sides of the rocket motor are opened to prevent pressure buildup in the rocket motor due to fuel combustion and, thus, prevent the rocket from generating thrust. BACKGROUND OF THE INVENTION The usual missile has a rocket motor and armament and guidance control systems. The armament has a safety thereon which prevents arming of the warhead until after it is launched. The warhead can be designed to be safe in a fire. However, when a missile motor or a rocket motor is subjected to temperatures which would be reached in a fortuitous fuel fire, the solid fuel of the rocket motor will ignite. Unless steps are taken, ignition will cause thrust and the missile will be propelled. Should this occur in an enclosed space such as a hangar or on an airport or a flight deck, the resultant missile flight is quite dangerous and destructive. Thus, there is need for a missile motor and rocket motor safety system which senses the ambient temperature and prevents the motor from developing thrust. In addition, the same safety problem exists with any pressure vessel or pressurized gas generator, which may develop thrust when a valve or fitting or adjacent line is burned off by an adjacent fire. SUMMARY OF THE INVENTION In order to aid in the understanding of this invention, it can be summarized that it is directed to a thermally actuated safety system wherein a thermal sensor detects temperature around the missile motor, rocket motor, gas generator or pressure vessel above a predetermined value and the system partially or completely cuts the motor case or other pressure vessel when the sensed temperature is reached in order to prevent fuel combustion or other violent pressure release from producing thrust or other damage. It is a purpose and advantage of this invention to provide a thermally actuated safety system wherein the rocket motor or pressure vessel is rendered ineffective to produce thrust when, while on the ground, it is subjected to temperatures over a sufficient time which will ignite the rocket motor fuel or violently burst the pressure vessel. It is a further purpose and advantage of this invention to provide a safety system which detects and responds to the ambient temperature condition surrounding a rocket motor or other pressure vessel such that when, on the ground, should these temperatures reach dangerous levels over a sufficient length of time, the rocket motor or pressure vessel casing is cut to laterally vent the products of rocket fuel combustion, thus significantly eleminating or releasing the contained pressure without generating significant thrust. Other purposes and advantages of this invention will become apparent from a study of the following portion of the specification, the claims and the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, with parts broken away, of a missile carrying the thermally actuated safety system of this invention. FIG. 2 is an enlarged section taken generally along the line 2--2 of FIG. 1. FIG. 3 is a further enlarged view of the control portion of the safety system, with parts broken away and parts taken in section, as seen when the cover is removed, generally along the line 3--3 of FIG. 1. FIG. 4 is a longitudinal section through the control portion, as seen generally along the line 4--4 of FIG. 3. FIG. 5 is an enlarged view of the safety latch shown in FIG. 3, with the latch in the safe position. FIG. 6 is a section through the control portion at the position of the safety latch, taken generally along line 6--6 of FIG. 4. FIG. 7 is an enlarged view, with parts broken away and parts taken in section, showing the sealing cap over the stem of the safety latch. FIG. 8 is an enlarged section through the cutting explosive cord which in the preferred embodiment is a linear shaped charge lying against the motor case, as seen generally along the line 8--8 of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION Missile 10 is broken away at the left or forward end thereof in FIG. 1. The forward end carries the guidance electronics and warhead of the missile. Most of the portion of the missile 10 shown in FIG. 1 is the rocket motor portion. The rocket motor has a case 12 which throughout most of its length is in the form of a cylindrical tube. The rocket motor case is normally closed, except for nozzle 14 at its rear end. Rocket motor case 12 normally carries a grain of solid rocket fuel therein. Upon combustion, this grain produces hot gas which raises the pressure within the rocket motor case. The hot gas is expelled from nozzle 14 producing thrust. Rocket motor case 12 is normally sufficiently strong to withstand the pressure of hot gas generation therein. The safety system of this invention is directed to opening the side of the rocket motor case 12 or weakening it sufficiently so that internal hot gas pressure causes opening of the side as the pressure rises. Missile 10 is carried on a rail on the aircraft by means of hook 16. There is a similar hook farther forward on the missile. Opposite the hook, harness cover 18 is secured to the outside of the motor case 12 and extends forward along the outside of the missile from the motor case. Harness cover 18 carries various usual electrical connections across the rocket motor between the guidance and control sections. The invention is illustrated in connection with a missile wherein the rocket motor case 12 is the outer wall of the aft part of the missile. This necessitates a harness cover which then also serves as a cover for the safety system of this invention. The harness cover also acts to provide an appropriate standoff distance for the thermal cord. In those missiles with a slip-in motor case, the system of this invention can be housed within the airframe with the thermal cord recessed into the skin. When the safety system is used with other gas generators or pressure vessels, the thermal cord can be positioned with hardware that provides the proper standoff. On its exterior surface, harness cover 18 has recesses 20 and 22 therein, see FIG. 2. Two lengths of thermal cord 24 and 26 lie in these recesses, substantially flush with the exterior of the harness cover 18. Thermal cords 24 and 26 are pyrotechnic devices which are specifically sensitive to temperature and are formulated to ignite (and provide a signal indicative thereof) when a preselected temperature and temperature duration have been reached. In the present case, thermal cords 24 and 26 self-ignite in a maximum time of 30 seconds when exposed to temperatures above 550° F. to 600° F. The signal must be provided by ignition of the thermal cords in a time less than the fast cookoff time of the rocket motor grain or other device being protected. The fast cook-off time is the time that the motor is exposed to a given temperature with a requirement for survival (i.e. no explosion or ignition of the motor fuel grain). Two cords are provided for redundancy. They are protected by a thin coat of black epoxy sealant. The inner ends of the cords 24 and 26 extend through an opening in harness cover 18, into an opening in the control module 28 to terminate in propellant 30 within bore 32 within control module 28. The outer end of bore 32 is closed by plug 34, see FIG. 4, which is held in place by pin 36. An O-ring around plug 34 aids in sealing, and in addition, packing is provided at the inner end of the plug and adhesive sealant is provided at the outer end of the plug. Propellant 30 generates hot gas when it is ignited by one of the thermal cords 24 or 26. With the right hand end of the bore 32 closed, as seen in FIG. 4, the gas expands to the left through the bore. Piston 38 is slidablly mounted in the bore and carries an O-ring therearound to protect propellant 30 before it is ignited and obturates the gas chamber. When the propellant is ignited, piston 38 is thrust to the left. Piston 38 carries firing pin 40 thereon. Firing pin 40 extends toward transfer assembly 42 which contains percussion primer 44 and booster charge 46. Booster charge 46 has an explosive output. The transfer assembly 42 carrying primer 44 and booster charge 46 is a separate unit inserted into bore 48 in the body of control module 28. Bore 48 is in line with bore 32. Firing pin 40 is of such length that when fired, the firing pin 40 strikes primer 44 so that flame is generated to the left through bore 48. Shear pin 41 holds piston 38 in its unactuated position until propellant 30 generates sufficient gas so that pressure shears the pin 41. Thereupon, the gas under pressure thrusts firing pin 40 to the left. Block ring 50 is of arcuate shape. It is in the form of a segment of a circular, tubular cylinder. Block ring 50 is positioned in its pocket 52, which is also of arcuate shape. Pocket 52 is sufficiently long to permit rotation of ring 50 within the pocket from the safe position illustrated in FIG. 3 to a firing position. In the safe position shown, block ring 50 completely closes off bore 48 so that the portion in which transfer assembly 42 is located is physically separated from the left end of the bore and prevents explosive transfer from the booster to the cutting charge. This is a physical barrier safety mechanism. This mechanism prevents ignition of primer 44 (without striking by the firing pin 40) from initiating flame propagation. Shear pin 58 prevents inadvertent rotation of the block ring. However, block ring 50 can be rotated so that window 54 in the block ring is in alignment with bore 48 to permit explosive propagation leftward through bore 48 when the unit is in firing condition. Actuator 56 is positioned in the way of firing pin 40 when block ring 50 is in the blocking position. When the firing pin 40 moves to the left, it engages on actuator 56 which moves to the left. As the actuator moves to the left, it engages ring 50, shears pin 58 and moves the ring to its non-blocking position. As actuator 56 moves to the left, it drops off of shoulder 60 to move out of the way of firing pin 40. Thereupon, firing pin 40 can strike and fire the primer 44 to cause explosive propagation leftward down bore 48. The left end of bore 48 has therein the end of an explosive charge such as linear shaped charge 62. As is seen in FIG. 8, the linear shaped charge 62 has a V-shaped linear explosive charge 64 and is captivated within charge holder 66 which, in turn, is surrounded by protective tubing 68. The charge holder is preferably of rubberlike material which maintains proper standoff. The protective tubing is of a suitable material for preventing moisture from collecting near the explosive. The protective tubing is preferably a heat-shrinking synthetic polymer composition material. Charge holder 66 carrying linear shaped charge 62 is secured by adhesive 69 within harness cover 18, as shown in FIG. 8. This maintains the charge at the proper standoff distance. When the explosive charge is ignited, it preferably cuts one or more stress raising notches in the outer portion of the case, or may cut directly through the case to the grain. The stress raising notches may be cut in selected locations along the length of the case. These notches or cuts are sufficient so that when the grain ignites, the rocket motor case splits and pressure is vented out of the split side rather than developing pressure which causes significant thrust by exhausting from the nozzle. In this way, the missile is prevented from uncontrolled flight due to fire while the missile is in storage, transport, or on the airplane prior to flight. Selectivity of notching or cutting along the length of the linear shaped charge can be controlled by insertion of an energy-absorbing structure such as lead wire within the V-groove along the charge in the lengths where no cutting is desired. The use of a shaped charge for case cutting is preferred. However, linear non-shaped explosives such as Primacord or non-linear explosives can be used for case cutting. When the case is subjected to fire, the exterior surface of the grain (next to the case) will burn so that pressure will build up between the grain and the case to split open the case at the stressraising notches. No nozzle thrust is produced because the interior of the grain is not ignited. The use of a stress-raising notch rather than a cut protects the grain from an exterior fire that might ignite the grain early if the case were split open. In addition, the explosion should not cause substantial distribution of debris, which could endanger nearby fire fighters. In some missiles, the aerodynamic heating of the missile 10 during normal flight is sufficiently high to cause ignition of the thermal cords 24 and 26. Of course, destruction of the missile in flight toward its target is undesired and, for this reason, in such missiles an inertial mechanism is provided in control module 28. Inertia mass 70 is positioned within pocket 72. Pocket 72 is sufficiently long to permit longitudinal sliding of the mass within the pocket. The side walls of the pocket guide the mass to limit it to longitudinal motion. Cover 74 encloses the mass within its pocket and also serves to cover block ring 50 within its pocket 52 and retain actuator 56 in its place. Compression spring 76 engages around firing pin 40 and between piston 38 and inertia mass 70. When the missile is accelerated upon launch, the acceleration forces inertia mass 70 to the right end of its pocket, compressing spring 76. With the inertia mass 70 in this position, piston 38 cannot move to the left because piston 38 is larger than the pocket in mass 70 in which lies spring 76. With mass 70 in the right position, the firing pin 40 cannot reach the primer in transfer assembly 42. Latch assembly 78 has shaft 80 which carries latch 82. When in the unactuated position shown in FIG. 3, latch 82 lies in longitudinal slot 84 in mass 70. Leaf spring 86 lies just outside of the slot 84 and is positioned and oriented to turn latch 82. It is seen that as the inertia mass 70 moves to the right with respect to the missile, from the position of FIG. 3 to the position of FIG. 5, the spring turns the latch. When the compression spring 76 attempts to return inertia mass 70 to the left, the latch engages against the end 88 of mass 70 because the latch is out-of-line with its slot. This retains inertia mass 70 in the rightmost position and prevents the firing pin 40 from moving to the left and precludes opening of the block ring and firing of the primer. The missile may be dropped, or otherwise subjected to accelerations during shipping and handling, which would cause the inertia mass to move to the safe position shown in FIG. 5 where the thermally actuated safety system is ineffective. In order to provide visual inspection of the position of the latch, boss 90 which carries the shaft 80 therein, extends outward into an opening in harness cover 18 as shown in FIG. 6 and FIG. 7. The outer end of shaft 80 of the latch assembly has slot 92 therein which is in line with latch 82. Thus, the slot 92 is visible from the exterior of the missile so that the state of the safety system can be readily inspected and observed. In order to prevent contamination from entering into control module 28 through the opening between shaft 80 and boss 90, transparent sealing cover 94 is snapped into place, see FIG. 7. The outer end of the shaft is undercut and cover 94 snaps into that undercut and firmly engages in the shaft hole within the boss. Since the cover 94 is transparent, the orientation of slot 94 can be inspected. Should the latch assembly be in the system inactive position of FIG. 5, it can be returned to the active position by removal of cover 94 and engagement of a screwdriver in slot 92. The screwdriver will rotate the latch into alignment with longitudinal slot 84, whereupon the spring will return the inertia mass 70 to the left, active position. As can be seen from this description of the structure, the entire thermally actuated rocket motor safety system is incorporated within the already existing harness cover 18. Therefore, there is no adverse influence upon the missile drag. Furthermore, the system is thermally activated, in direct response to high ambient temperature and sufficient time. The system is arranged so that the temperature sensing portion is remote from the rocket motor case cutter. Since it is remote, the control module 28 can be placed therebetween. The control module maintains the system in the armed state and is placed in a safe condition by acceleration of the missile after the missile launch to prevent inadvertent firing of the rocket motor case cutter due to aerodynamic heating. The armed and safe positions are visible by inspection from the exterior of the missile. In this way, a thermally actuated rocket motor safety system provides safety against missile thrust due to fire near the missile while the missile is on the ground, during storage, transport or positioning on the aircraft ready for use. This invention has been described in its presently contemplated best mode, and it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims.

A thermally actuated rocket motor safety system has a fire temperature pyrotechnic sensor which ignites a gas generator (30) which drives piston (38) to the left. Firing pin (40) strikes the primer in transfer booster assembly (42). The transfer booster assembly transmits explosive energy through window (54) in now open block ring (50) to initiate charge (62) which lies adjacent the rocket motor case. This stresses the rocket motor case by producing a stress raising notch in the case wall. Subsequent grain burning opens the case to vent the rocket motor pressure. Inertia mass (70) slides to the right upon acceleration due to normal rocket motor firing and locks in the rightmost position by means of latch (82). In the locked position, inertia mass (70) prevents leftward motion of the firing pin (40).

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a technique of fabricating a light guide used for a liquid crystal display, and more particularly to a light guide fabricating apparatus and a manufacturing method thereof having a simplified mold structure. 2. Description of the Related Art Generally, a liquid crystal display (LCD) controls light transmissivity of liquid crystal cells arranged in a matrix pattern with the aid of a video signal applied thereto to display a picture corresponding to the video signal. To this end, the LCD includes a liquid crystal display panel having liquid crystal cells arranged in an active matrix which control an amount of light transmitted from the lower portion thereof; a backlight unit for emitting light from the lower portion of the liquid crystal display panel; red, green and blue color filters corresponding to each liquid crystal cell at the lower portion of the liquid crystal display panel; and a black matrix layer for defining pixels. The backlight unit functions to evenly emit white light from the rear side of the liquid crystal display panel, and consists of a light source, a light guide, a reflector and a diffuser, etc. for uniformly transmitting light emitted from the light source into the panel. FIG. 1 shows a sectional structure of a conventional backlight unit provided at the lower portion of a liquid crystal display panel. Referring to FIG. 1, the backlight unit includes a backlight lamp 22 for generating white light, a prism light guide 4 for guiding light passing through a light input 20 from the backlight lamp 22 , a lamp housing 24 for mounting the backlight lamp 22 and reflecting light into the light guide 4 , a reflector 2 for reflecting light from the lower portion of the prism light guide 4 toward the upper portion thereof where the liquid crystal display panel is positioned, first and second diffusing films 6 and 12 , and first and second prism films 8 and 10 for controlling diffusion and transmission direction of the light passing through the prism light guide 4 . The light guide 4 is formed in a prism shape with an inclined lower surface as shown in FIG. 2 and allows light inputted from the backlight lamp 22 to smoothly progress toward the upper portion thereof. Light transmission, via the lower surface of the prism light guide 4 , toward the lower portion thereof is reflected upward by the reflector 2 provided at the lower portion of the light guide 4 . Light passing through the prism light guide 4 is uniformly diffused by means of the first diffusing film 6 . Light passing through the first diffusing film 6 is controlled to make its transmission direction perpendicular to the liquid crystal display panel at the first and second prism films 8 and 10 . Light passing through the first and second prism films 8 and 10 is incident on the liquid crystal display panel by way of the second diffusing film 12 again. For instance, the lower surface of the prism light guide 4 is inclined and provided with minute grooves 26 having a uniform distance as shown in FIG. 2 . Such grooves 26 are referred to as “prism unevenness”, which smooths a diffusion of light as well and reduces light loss on a path where light is transmitted toward the upper portion of the light guide 4 . This increases the amount of light transmitted toward the liquid crystal display panel. Typically, the prism light guide 4 is made from an acryl such as PMMA, etc., and the grooves 26 are formed in an equal distance to have a pitch width of about 0.07 to 0.08 mm by a machine working. The prism light guide 4 having the structure as mentioned above is, for example, fabricated by an injection-molding device 30 as shown in FIG. 3 . Referring to FIG. 3, the conventional light guide injection-molding device 30 consists of a stamper 32 for forming groves 26 , a stationary core 34 to which the stamper 32 is attached, a vacuum tube 36 and a vacuum device (not shown) for attaching the stamper 32 to the stationary core 34 by a vacuum force, a stamper fixing segment 38 provided at the side portion of the stationary core 34 to determine an attached position of the stamper 32 , a movable core 40 defining a mold 46 along with the stationary core 34 , and a stationary molding plate 42 and a movable molding plate 44 for fixing the stationary and movable cores 34 and 40 at the exterior thereof. The stationary core 34 has a thickness of about 20 mm while the stamper 32 has a thickness of about 0.1 to 0.4 mm. In the conventional art, a brass plate (which is easy to work by a grinding process) is preferably used to make the stamper 32 . Recently, a high-hardness nickel has been used because the relatively soft brass plate wears too easily, which affects mass production operation. However, since nickel is very hard, it is difficult to form the grooves 26 at an equal distance by a grinding process. In order to solve this problem, a nickel stamper 32 has been made by using a brass plate provided with the prism unevenness grooving as a master, then electroplating nickel on the surface of the brass plate provided with the prism unevenness grooving to a desired thickness. In manufacturing the stamper 32 according to the electroplating method, the stamper 32 has a thickness of about 0.1 to 0.4 mm because it is difficult to make a large plating thickness. Hereinafter, a conventional method of fabricating the prism light guide 4 is described. First, a position of the stamper 32 to be attached to the stationary core 34 is determined by the stamper fixing segment 38 . The stamper 32 is then attached to the attached portion of the stationary core 34 . The portion of the stamper 32 attached to the stationary core 34 has a plurality of vacuum holes connected the vacuum tube 36 . The stamper 32 is attached to the stationary core 34 by a vacuum force provided by evacuating air through the vacuum tube 36 . Thereafter, a prism light guide material is injected into a space between the stationary core 40 and the stamper 32 and then injection-molded to be made into the prism light guide 4 having the prism unevenness grooves 26 . The conventional injection-molding device has a structure in which the stamper 32 is separate from the core 34 of the mold 46 . The stamper 32 is temporarily attached to the stationary core 34 of the mold 46 by evacuating air through the vacuum holes provided at the attached portion of the stamper 32 to the stationary core 34 . Such a stamper fixing method is mainly used for a product that must be changed frequently. In conventional compact disc injection-molding device (as an example of another application), various kinds of discs must be formed so various kinds of stampers must be changed frequently. Thus, the stamper fixing method employing a vacuum system is used in which attachment and detachment of the appropriate stamper is easy. However, the prism light guide 4 in the LCD is mass produced and therefore does not require frequent attachment and detachment of the stamper until a life of the stamper 32 expires. Therefore, the above-mentioned stamper attaching method using a vacuum system is not available. The conventional injection-molding device 30 has a drawback because it requires an additional device for evacuating air and the attached portion of the stamper 32 to the stationary core 34 must be provided with a plurality of vacuum holes, so device 30 has complex structure and facilities. Also, the conventional injection-molding device 30 unstable attachment due to a deterioration of the vacuum force applied to the stamper 32 , its manufacturing becomes unstable. Furthermore, it is inconvenient because cleaning and fine surface grinding work, etc. on the attached portion of the stationary core 34 to the stamper 32 are required to provide an easy air evacuation and strengthen the vacuum force. SUMMARY OF THE INVENTION Accordingly, the present invention provides an apparatus for manufacturing a light guide in a liquid crystal display and a manufacturing method thereof wherein a mold structure is simplified. The present invention also provides an apparatus for manufacturing a light guide in a liquid crystal display and a manufacturing method thereof that are adapted to make a stable light guide molding work. Therefore, a light guide fabricating apparatus according to one aspect of the present invention includes a stamper for molding a light guide; a core material portion with a desired thickness fixed to the stamper, to constitute an integral molding core; and a fixing member or structure for fixing the stamper to the core material portion, said integral-type molding device defining a mold for molding the light guide along with the stationary core and the movable core. A method of manufacturing a light guide fabricating apparatus according to another aspect of the present invention includes fixing a light guide molding stamper to a core material portion having a desired thickness to form an integral mold core; and fixing the integral mold core to the stationary core and the movable core to define a mold. BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects of the present invention will be apparent from the following detailed description of the embodiments of the present invention with reference to the accompanying drawings, in which: FIG. 1 is a section view showing a structure of a general backlight unit provided at the lower portion of a liquid crystal display panel; FIG. 2 is a section view showing a detailed structure of the prism light guide in FIG. 1; FIG. 3 is a section view showing a structure of a conventional injection-molding device used for fabricating the prism light guide; FIG. 4 is a section view showing a structure of a light guide fabricating apparatus according to a first embodiment of the present invention; FIG. 5A to FIG. 5E are section views for explaining a method of manufacturing a stamper-integrated mold core according to a first embodiment of the present invention; FIG. 6 is a section view showing a structure of a light guide fabricating an apparatus for molding double-faced prism unevenness grooving having an integral mold structure according to the first embodiment of the present invention; and FIG. 7 is a section view showing a structure of a light guide fabricating apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 4, a light guide fabricating apparatus according to a first embodiment of the present invention is shown. In the conventional light guide injection-molding device, a stamper for injection-molding the prism light guide is separate from a core. However, in a light guide injection-molding device according to the first embodiment of the present invention, the stamper is engaged to a core material portion having a desired thickness to be made into an integral mold. In order to form prism unevenness grooves having the same shape at the lower surface of a prism light guide 52 , the injection-molding device 50 includes a stamper 54 provided with prism unevenness grooves at a surface contacting an injected light guide material, a core material portion 58 to which the stamper 54 is attached by virtue of a nickel electroplate structure 56 on the surfaces of the stamper 54 and the core material portion 58 , a movable core 62 for fixing an integral molding device 60 in which the stamper 54 and the core inside material 58 are fixedly joined by nickel electroplating 56 , a stationary core 66 of a mold 64 provided along with the integral molding device 60 and the movable core 62 , and a stationary molding plate 68 and a movable molding plate 70 for fixing the stationary core 66 and the movable core 62 , respectively. The stamper 54 is formed about 0.3 to 0.4 mm thick by electroplating nickel on the surface of a brass plate master provided with prism unevenness grooves. The core material portion 58 to which the stamper 54 is attached uses the same metal (e.g., nickel) as the stamper 54 or a different metal (e.g., Prehardening steel) from the stamper 54 , and has a thickness of about 20 to 30 mm. The prism light guide 52 is manufactured by injecting a substance such as acryl, etc. into a space between the integral molding device 60 fixed with the stamper 54 and the stationary core 66 under pressure. The light guide fabricating apparatus according to the present invention does not require additional complex facilities such as the conventional vacuum device, etc. because the stamper 54 and the core inside material 58 are mutually bonded to each other by virtue of the nickel electroplate 56 on the surface thereof. Accordingly, it is possible to provide a simplified mold structure as well as more stable manufacturing of the prism light guide 52 because the stamper 54 is always kept attached to the inside material portion 58 . In a first embodiment of the present invention, a method of manufacturing the molding device 60 will be described with reference to FIGS. 5A to FIG. 5 E. First, as shown in FIG. 5A, prism unevenness grooves 82 are formed on the surface of a brass plate by a grinding process employing, for example, a bit 80 to prepare a master 84 . By a mechanical machining using the bit 80 , a pitch width P of the prism unevenness grooves 82 are formed at equal distances on the surface of the master 84 , from 0.07 to 0.08 mm. Next, as shown in FIG. 5B, the surface of the master 84 provided with the prism unevenness grooves 82 is electroplated with nickel to form a nickel electrotype 86 . Subsequently, as shown in FIG. 5C, the nickel electrotype 86 is separated from the master 84 to provide a nickel electrotype 86 having the prism unevenness grooves 82 . Then, the rear and side surfaces of the electrotype 86 are machined to complete the nickel stamper 54 . In this case, the stamper 54 has a thickness of about 0.3 to 0.4 mm. Finally, the manufactured stamper 54 is put on the core material portion 58 with a thickness of 20 to 30 mm to perform an electrotyping work for fixing the stamper 54 and the core material portion 58 . In other words, as shown in FIG. 5E, the surfaces of the stamper 54 and the core inside material portion 58 are electroplated with nickel to form a nickel sealing electroplate 56 . The core material portion 58 may be made from the same metal material (e.g., nickel) as the stamper 54 or a different metal material (e.g., Prehardening steel). Consequently, the integral-type molding device 69 in which the stamper 54 and the core material portion 58 are sealed together by the nickel electroplate 56 is completed. Such a molding device also is applicable to a molding device for forming unevenness grooves at both sides of the prism light guide. In this case, groove-forming stampers 92 and 94 are provided at the upper and lower portions of the injection-molded prism light guide 90 , respectively, as shown in FIG. 6 . The stamper 92 for forming prism unevenness grooves on the lower surface of the prism light guide 90 is fixed to a core material portion 98 at the lower portion thereof by a nickel electroplate 96 similar to that in FIG. 4, to make molding device 106 . On the other hand, the upper stamper 94 for forming the prism unevenness grooves on the upper surface of the prism light guide 90 is fixed to an upper core material portion 102 by an upper nickel electroplate 100 to make an upper molding device 104 . A general core metal such as Prehardening steel is used as the lower and upper core material portions 98 and 102 . Since complex features such as an additional vacuum device for fixing the stampers are not required, the mold structure can be simplified. Also, because the lower stamper 92 or the upper stamper 94 is always fixed to the core material portions 98 and 102 by the nickel electroplates 96 and 100 , a stable injection-molding work can be made. Referring to FIG. 7, a light guide fabricating apparatus according to a second embodiment of the present invention is shown. In a light guide injection-molding device according to the second embodiment of the present invention, a stamper is engaged with a core by bolt members to provide a mold. In order to form prism unevenness grooves on the lower surface of prism light guide 112 , the light guide injection-molding device 110 includes a stamper 114 provided with prism unevenness grooves on a surface contacting an injected light guide material, a molding core 116 to which the stamper 114 is attached, one or more bolts 118 for engaging the stamper 114 with the molding core 116 , a stationary core 126 constituting a mold 124 along with the integral-type molding device 120 made by engaging the stamper 114 and the molding core 116 , and a movable core 122 , and a stationary molding plate 128 and a movable molding plate 130 for fixing the stationary core 126 and the movable core 122 at the exterior thereof, respectively. The stamper 114 is manufactured by the nickel electroplating system using a brass plate master like the first embodiment. In the second embodiment, however, since bolt holes are formed in the stamper 114 to engage the stamper 114 and the molding core with bolts, the plated electrotype must have a middle thickness of about 6 to 12 mm. For the sake of bolt-engaging, the stamper 114 is put on the molding core 116 and a plurality of bolt-engaging holes are formed from the lower portion of the molding core 116 to a desired depth of the stamper 114 by a grinding process. Bolts 118 are then inserted into the holes to fix the stamper 114 to the molding core 116 . By this method, the mold structure can not only be simplified, but also the stamper 114 can also be stably fixed to the molding core 116 . The stamper-integrated mold structure employing the bolt-engagement system is also applicable to a double-faced unevenness-molding device for transcription-molding both sides of the prism light guide. In this case, the upper and lower stampers are fixed to the stationary and movable cores, respectively, by bolts to be integrally formed. As described above according to the present invention, a light guide molding stamper is fixed to an core material portion by nickel electroplate or by bolt members and the like. Such a fixing method is advantageous because it is useful for mass production of a mold structure with a considerably simplified structure. In addition, fixing the stamper to the core material portion of the core as well as stable product manufacturing can be obtained. Although the present invention has been explained by the embodiments shown in the drawings described above, it should be understood to the ordinary skilled person in the art that the invention is not limited to the embodiments, but rather that various changes or modifications thereof are possible without departing from the spirit of the invention. Accordingly, the scope of the invention shall be determined only by the appended claims and their equivalents.

An apparatus for manufacturing a light guide in a liquid crystal display and a manufacturing method thereof with a simplified mold structure. In the apparatus, an core material portion is fixed to a light guide molding stamper to constitute a molding device along with the stamper. A fixing member fixes the stamper to the core material portion. The molding device constitutes a mold for molding the light guide, along with a stationary core and a movable core. Accordingly, the stamper and the molding core are integrally formed and sealed, so that a mold structure can be simplified and stable manufacturing of the light guide can be provided.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is entitled to the benefit of French Patent Application No. 0511846 filed on Nov. 23, 2005. FIELD OF THE INVENTION The invention relates to a method of fabricating a lug on a structural element of composite material, in particular a connecting rod. BACKGROUND OF THE INVENTION Connecting rods are known that comprise a hollow body of composite material, e.g. obtained by winding filaments around a mandrel, or indeed by winding a ply of woven fibers. The thickness of the hollow body is obtained by winding an appropriate number of turns. Composite material connecting rods are also known in which the solid body is made by stacking plies. It is also known to provide extensions, either from the wall of the hollow body or from the solid body that serve to become the lugs of coupling forks. After the body has been polymerized, it suffices to pierce holes in the extensions and possibly to cut them to shape in order to obtain the lugs. Nevertheless, the thickness of the lugs obtained in that way is the same as the thickness of the wall of the hollow body or the thickness of the solid body. Unfortunately that thickness is not necessarily sufficient. The state of the art is illustrated by the following patent documents: FR 2 060 049, DE 37 26 340, FR 2 705 610, U.S. Pat. No. 5,279,892, U.S. Pat. No. 6,036,904. OBJECT OF THE INVENTION An object of the invention is to propose a novel method of producing one or more lugs on a structural element of composite material. BRIEF DESCRIPTION OF THE INVENTION To achieve this object, the invention provides a method of fabricating a lug on a structural element of composite material made at least locally out of a stack of primary plies of composite fibers defining at least one extension for forming the lug, the method including the step of separating the primary plies at least in the extension and of inserting intermediate plies between the primary plies. Thus, the thickness of the extension is no longer tied to the thickness of the structural element. In particular the extension can be made thicker in order to obtain a lug of suitable thickness. BRIEF DESCRIPTION OF THE DRAWINGS The invention can be better understood in the light of the following description given with reference to the figures in the accompanying drawings, in which: FIG. 1 is a perspective view of a connecting rod obtained by the method of the invention; FIG. 2 is a face view of a cut-out pattern for fabricating a connecting rod of the invention; FIG. 3 is a section on line III-III through the body of the FIG. 1 connecting rod; FIG. 4 is a fragmentary view of the FIG. 1 pattern seen edge-on; FIG. 5 is a section view on line V-V of FIG. 1 ; and FIG. 6 is a diagrammatic view of a fabric comprising a plurality of bonded-together plies suitable for use in implementing the method of the invention. DETAILED DESCRIPTION OF THE INVENTION With reference to FIG. 1 , the method of the invention serves to obtain a completely composite connecting rod 100 comprising a tubular body 102 with two forks 103 , each comprising two facing lugs 104 . According to a particular aspect of the invention shown in FIG. 2 , an initial step lies in cutting out a pattern 110 from a fiber fabric, a carbon fiber fabric in this example, which pattern 110 has a central portion 111 with two opposite edges 112 and has four extensions 113 projecting therefrom, comprising two extensions at each end of the central portion 111 , on either side of an axis of symmetry 114 of the pattern. The fiber fabric is preferably obtained from a so-called “2.5 D” weave, comprising a plurality of primary plies having weft fibers interconnected by warp fibers that extend from one primary ply to another in order to bond the primary plies together. Such bonding between the primary plies enables them to be secured to one another, while allowing for relative sliding between the primary plies while the pattern is being shaped. In this respect, the preferred fabric is the fabric described in patent document FR 2 759 096, and described below with reference to FIG. 6 . The fabric comprises a basic weave that is constituted: firstly by at least twenty-eight weft fibers 1 to 28 organized in at least eight columns C 1 to C 8 each extending in the thickness direction E of the fabric, and disposed in a staggered configuration with alternation between columns C 2 , C 4 , C 6 , C 8 having at least three superposed weft fibers spaced apart at a predetermined pitch P, and columns C 1 , C 3 , C 5 , C 7 having at least four superposed weft fibers spaced apart by the same pitch P, the weft fibers 1 to 28 extending to define at least seven primary plies N 1 to N 7 ; and secondly, by at least twelve warp fibers 29 to 40 disposed in at least four parallel planes P 1 , P 2 , P 3 , P 4 that are offset in the weft fiber direction, each plane containing three superposed parallel warp fibers arranged in each of these planes as follows: a first warp fiber (respectively numbered 29 , 32 , 35 , 38 ) connects the topmost warp fiber ( 1 , 8 , 15 , 22 ) of a four-weft fiber column (C 1 , C 3 , C 5 , C 7 ) to an upper intermediate weft fiber ( 16 , 23 , 2 , 9 ) of a four-weft fiber column (C 5 , C 7 , C 1 , C 3 ) that is spaced apart from the preceding column by at least two pitch steps P, the first warp fiber returning over a top end weft fiber ( 1 , 8 , 15 , 22 ) of a four-weft fiber column (C 1 , C 3 , C 5 , C 7 ) that is spaced apart from the first column by at least four pitch steps P; a second warp fiber (respectively numbered 30 , 33 , 36 , 39 ) connecting a top intermediate weft fiber ( 2 , 9 , 16 , 23 ) of a four-weft fiber column (C 1 , C 3 , C 7 ) to a lower intermediate weft fiber ( 17 , 24 , 3 , 10 ) of a four-weft fiber column (C 5 , C 7 , C 1 , C 3 ) that is spaced apart from the preceding column by at least two pitch steps P, the second warp fiber returning over an upper intermediate weft fiber ( 2 , 9 , 16 , 23 ) of a four-weft fiber column (C 1 , C 3 , C 5 , C 7 ) that is spaced apart from the first column by at least four pitch steps P; and a third warp fiber (respectively numbered 31 , 34 , 37 , 40 ) connecting a lower intermediate weft fiber ( 3 , 10 , 17 , 24 ) of a four-weft fiber column (C 1 , C 3 , C 5 , C 7 ) to the bottommost weft fiber ( 18 , 25 , 4 , 11 ) of a four-weft fiber column (C 5 , C 7 , C 1 , C 3 ) spaced apart from the preceding column by at least two pitch steps P, the third warp fiber returning over a lower intermediate weft fiber ( 3 , 10 , 17 , 24 ) of a four-weft fiber column (C 1 , C 3 , C 5 , C 7 ) that is spaced apart from the first column by at least four pitch steps P. The positions of the parallel warp fibers ( 29 , 30 , 31 ; 32 , 33 , 34 ; 35 , 36 , 37 ; 38 , 39 , 40 ) are offset longitudinally by one pitch step P from one plane to another. Continuous lines represent the warp fibers 29 , 30 , 31 of plane P 1 , short dashed lines represent the warp fibers 23 , 33 , 34 of plane P 2 , chain-dotted lines represent the warp fibers 35 , 36 , 37 of plane P 3 , and finally long dashed lines represent the warp fibers 38 , 39 , 40 of the plane P 4 . The offset can be seen particularly clearly. Returning to FIG. 2 , the pattern 110 is cut out from said fabric in such a manner that the weft fibers extend along the axis of symmetry 114 of the pattern 110 . According to a particular aspect of the invention, the pattern 110 is then rolled up to form a tube by bringing its edges 112 close together. As shown diagrammatically in FIG. 3 , the plies of the fabric slide relative to one another, with sliding being zero on the axis of symmetry 114 and at its maximum in the vicinity at the edges 112 , such that the edges take on a chamfered shape. The edges 112 are then placed against one another. Preferably, the end face of one of the edges 112 bears against the inside face of the pattern 110 so that the thickness of the resulting tube is substantially constant in the join zone. Since the edges 112 are not parallel in this example, a tubular portion is obtained that is conical in shape. However it would be possible to obtain a cylindrical tubular portion in the same manner by cutting the pattern 110 to have edges 112 that are parallel. According to a particular aspect of the invention, as shown in FIG. 4 , the warp fibers are removed from the ends of the extensions 113 in order to separate the primary plies formed by the weft fibers. This produces primary plies N 1 to N 7 (seen edge-on and represented by thick lines) that can be spaced apart from one another. Intermediate plies 116 (represented by fine lines with only one intermediate ply being given a reference) are inserted between adjacent primary plies so that the fibers constituting the intermediate plies 116 extend obliquely, preferably at 45° relative to the weft fibers making up the primary plies N 1 to N 7 . The intermediate plies 116 are preferably disposed in such a manner as give the extensions 113 thickness that varies progressively so as to reach an end thickness that is constant and substantially twice that of the fabric. To do this, intermediate plies 116 are inserted of lengths that increase with increasing distance from the center of the extension 113 . Transverse fibers 117 are then introduced across the primary plies N 1 to N 7 and the intermediate plies 116 in order to reinforce the ends of the extensions 113 (the transverse fibers are represented by dashed lines, with only one of them carrying a reference in the figure. This gives a three-dimensional structure to said end that is particularly strong and that prevents the plies from sliding one on another. The transverse fibers are preferably inserted by stitching. The pattern fitted with its intermediate plies is shaped on a mandrel (not shown). Thereafter, using the conventional resin transfer molding (RTM) technique, resin is diffused between the fibers of the pattern and of the intermediate plies. The overlapping edges 112 are thus bonded together by the resin. The overlapping chamfers provide a larger bonding area between the two edges 112 such that the join (visible in FIG. 1 ) is very strong and makes the connecting rod suitable for withstanding stresses both in tension and in compression. This produces a strong tubular body with two arms of increased thickness at each end formed by the extensions, said arms extending facing each other in pairs. It then remains to cut the arms to shape and to pierce them in order to transform them into the lugs 104 . This produces the connecting rod shown in FIG. 1 that is made entirely out of composite material. Preferably, and as shown in FIG. 5 , the lugs are each provided with a pair of rings 120 , each pair comprising a first ring 121 having a cylindrical portion 122 extending in the hole in one of the lugs 104 , together with a collar 123 extending against one of the flanks of the lugs 104 , and a second ring 125 having a cylindrical portion 126 extending tightly inside the cylindrical portion 122 of the first ring 121 , together with a collar 127 that bears against the end of said cylindrical portion 122 . The length of said cylindrical portion 122 is preferably very slightly shorter than the width of the lug 104 so that the lug is lightly clamped between the collars 123 and 127 . Such a connecting rod is advantageously used for constituting folding braces or stays for landing gear. Such braces comprise two connecting rod elements that are hinged together and that work essentially in traction and compression, such that the connecting rod of the invention can advantageously be used in such an application. In addition, it is known that such braces or stays can also be subjected to impacts, e.g. from stones thrown up by the tires. The “2.5 D” fabric used is specifically well-known for its high resistance to impacts and to delamination. Dimensioning has shown that the saving in weight compared with metal braces or stays is significant. Furthermore, manufacturing time is considerably shortened. The invention is not limited to the description above, but on the contrary covers any variant coming within the ambit defined by the claims. In particular, although the use of a particular fabric is described with reference to FIG. 6 , it is possible to use a similar fabric having a larger number of primary plies, or indeed to use other fabrics that allow primary plies to slide relative to one another. Such a fabric can be obtained by superposing primary plies and stitching them together loosely. In order to reinforce the edge-to-edge join, it is possible to stitch the two edges together before polymerization. Although the method of the invention is associated with a connecting rod, the method of the invention can be applied equally well to any other structural element made of composite material.

The invention provides a method of fabricating a lug on a structural element of composite material made at least locally out of a stack of primary plies of composite fibers defining at least one extension for forming the lug. The method includes the step of separating the primary plies at least in the extension and of inserting intermediate plies between the primary plies.

This is a continuation of application Ser. No. 485,284, filed July 2, 1974 now abandoned. BACKGROUND This invention relates to the Preparation of α-amino-β'-nitroanthraquinone According to German Offenlegungsschrift No. 2,211,411, α,β-diaminoanthraquinones are obtained by reacting α,β-dinitroanthraquinones with ammonia in acid amides. SUMMARY Surprisingly, it has now been found that α-amino-β'-nitroanthraquinones can be obtained in high yields by reacting α,β'-dinitroanthraquinones with ammonia in water, ethers, aliphatic or cycloaliphatic or, aromatic hydrocarbons which may optionally be substituted by alkyl groups or, optionally, in mixtures of these compounds. Accordingly, this invention relates to a process for the production of α-amino-β'-nitroanthraquinones, which is characterised by the fact that α,β'-dinitroanthraquinones and ammonia are reacted in ethers, aliphatic, cycloaliphatic or in aromatic hydrocarbons which may optionally be alkyl-substituted in water or in mixtures of these compounds, preferably under pressure, at elevated temperature, i.e., at a temperature of at least 100° C., preferably at a temperature in the range of from 100° to 220° C. and, more particularly, at a temperature of from 140° to 200° C., the ammonia and α,β'-dinitroanthraquinone being reacted in a molar ratio of at least 3 : 1, more especially within the range of 10 : 1 to 40 : 1 and, more especially in a molar ratio in the range of from 15 : 1 to 30 : 1. DESCRIPTION It is possible to use both pure 1,6- and 1,7-dinitroanthraquinone, which may be obtained, for example, in accordance with Helv. Chim. acta 14, 1404, and also mixtures of these compounds. Suitable ethers are, in particular, aliphatic, cycloaliphatic and aromatic ethers, such as dibenzylether, di-sec.-butylether, diisopentylether, ethyleneglycol dimethylether, diethyleneglycol dimethylether, diethyleneglycol diethylether, methoxycyclohexane, ethoxycyclohexane, dicyclohexylether, anisole, phenetol, diphenylether, 2-methoxynaphthalene, tetrahydrofuran, dioxan, amylphenylether, benzylisoamylether, dibenzylether, diglycol-di-n-butylether, glycolmethyleneether and methylbenzylether. Suitable aliphatic and cycloaliphatic hydrocarbons are, for example, n-pentane, n-hexane, n-heptane, cyclohexane, methylcyclohexane, cyclododecane, decalin, cycloheptane, cyclopentane, n-decane, 1,2-dimethylcyclohexane, 1,3-dimethylcyclohexane, 1,4-dimethylcyclohexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, isopropylhexane, methylcyclohexane, 2-methylheptane, 3-methylheptane, 4-methylheptane, 2-methylhexane, 3-methylhexane, 2-methyloctane, 3-methyloctane, 4-methyloctane, 2-methylpentane, 3-methylpentane, n-octane, penta-isobutane, triethylmethane, 2,2,3-trimethylpentane, 2,2,4-trimethylpentane and 2,2,3-trimethylpentane. Suitable aromatic hydrocarbons are, for example, benzene, toluene, o-, m-, p-xylene, isopropylbenzene, trimethylbenzene, diethylbenzene, tetramethylbenzene, diisopropylbenzene, isododecylbenzene, tetralin, naphthalene, methylnaphthalene diphenyl, diphenylmethane, o-, m-, p-cymol, dibenzyl, dihydronaphthalene, 2,2'-dimethyldiphenyl, 2,3'-dimethyldiphenyl, 2,4'-dimethyldiphenyl, 3,3'-dimethyldiphenyl, 1,2-dimethylnaphthalene, 1,4-dimethylnaphthalene, 1,6-dimethylnaphthalene, 1,7-dimethylnaphthalene, 1,1-diphenylethane, hexamethylbenzene, isoamylbenzene, pentamethylbenzene, 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, 1,2,7-trimethylnaphthalene and 1,2,5-trimethylnaphthalene. According to a preferred embodiment the process according to the invention is carried out under the following conditions: at a temperature of at least 100° C., preferably at a temperature in the range of from 100° to 220° C., and more especially at a temperature in the range of from 140° to 200° C. and with a molar ratio (of ammonia to α,β'-dinitroanthraquinones) of at least 2 : 1, preferably in the range of 10 : 1 to 40 : 1 and more particularly in the range of 15 : 1 to 30 : 1. The reaction is generally carried out under superatmospheric pressure. The reaction time is governed by the reaction temperature, the reaction pressure and the molar ratio, the reaction velocity increasing with increasing temperature and increasing molar ratio. For example, if the reaction is carried out at a pressure above 30 atms and with a molar ratio of 10 : 1 at a temperature of 200° C; 150° C.; or 130° C., the reaction is completed after 0.5; 3; or 5 hours, respectively hours, whereas, for example, with a molar ratio of 50 : 1 and a reaction temperature of 100° C.; or a ratio of 30 : 1 at 130° C. or a ratio of 20 : 1 at 150° C., the reaction can be expected to take less than 5 hours; less than 4 hours or 0.5 hours respectively. The process can be carried out either continuously or in batches. The reaction mixture can be worked up by conventional methods, for example by filtering off the product crystallised out of the organic solvent after cooling to room temperature. The mother liquor which accumulates can be recycled to the reaction. However, the reaction mixture can also be worked up by distilling off the solvent or by precipitating the α-amino-β'-nitroanthraquinones with the aid of a diluent which reduces the solubility of the α-amino-β'-nitroanthraquinones in the reaction solution (for example petroleum ether). If desired, the reaction product can be further purified by treatment with acids, for example sulphuric acid, or by distillation in vacuo. α-Amino-β-nitro-anthraquinones are dyes for synthetic fibres, or intermediate products for the production of these dyes which are obtained, for example, by acylating the amino group or by halogenation and/or optionally by other conversions of the kind known for α-amino-anthraquinones. EXAMPLE 1 A mixture of 310 g of 1,6-dinitroanthraquinone (96%) and 1 liter of toluene was reacted with 170 g of ammonia in an autoclave for 2 hours at a temperature of 150° C. (molar ratio 10 : 1; pressure 50 atms). After cooling to room temperature, the reaction mixture was filtered under suction, the residue was washed with a little toluene and dried in vacuo. Yield: 277 g of a 93.1% 1-amino-6-nitroanthraquinone (96% of the theoretical yield). Similar yields and purity levels can be obtained by using, instead of toluene, benzene, 1,3,5-trimethylbenzene, isopropyl benzene, isododecylbenzene, diphenylmethane, n-hexane, n-heptane, decalin, tetralin, methylcyclohexane, cyclododecane, n-dipropylether, dibutylether, diethyleneglycol dimethylether, diethyleneglycol diethylether, methoxycyclohexane, dicyclohexyl ether, anisole, phenetol, diphenylether, tetrahydrofuran, dioxan or mixtures thereof. EXAMPLE 2 A mixture of 301 g of 1,7-dinitroanthraquinone (99%) and 1 liter of ethyleneglycol dimethylether was reacted with 510 g of ammonia in an autoclave over a period of 4 hours at a temperature of 130° C. (molar ratio 30 : 1; pressure 60 atms). After cooling, the reaction mixture was poured into 5 litres of water and the deposit which precipitated was filtered off under suction, washed with water and dried. Yield: 264 g of a 93% 1-amino-7-nitroanthraquinone (91% of the theoretical yield). EXAMPLE 3 310 g of 1,6-dinitroanthraquinone (96%) were reacted 0.5 hours with 340 g of ammonia (molar ratio 20:1; pressure 80 atms) in 1 liter of n-pentane in an autoclave at 150° C.; the reaction mixture obtained was freed from the solvent by distillation. Residue: 269 g of a 91.5% 1-amino-6-nitroanthraquinone (89% of the theoretical yield). EXAMPLE 4 A suspension of 317 g of 1,7-dinitroanthraquinone (94%) in 2 liters of water was stirred with 340 g of ammonia (molar ratio 20 : 1; pressure 40 atms) in an autoclave for a period of 2 hours at a temperature of 180° C. After venting, the reaction mixture was filtered under suction at room temperature. The mother liquor was recycled, whilst the residue was dried. Yield: 274 g of a 90% 1-amino-7-nitroanthraquinone (92% of the theoretical yield).

α-Amino-β'-nitroanthraquinone is prepared by reacting α,β'-dinitroanthraquinone with ammonia in an ether, an aliphatic, a cycloaliphatic or an optionally alkyl-substituted aromatic hydrocarbon, water or a mixture of the foregoing.

BACKGROUND OF THE INVENTION This invention relates to a vibratory pump applicable to pump liquids. A vibratory pump is known, which includes a housing of synthetic material and formed of a lower part and an upper part linked to each other by means of a connection which is formed in the lower part, an axial oscillating member and a static electric bobbin covered with resin and acting on a movable electric bobbin, which is placed in the axial oscillating member. The middle region of the oscillating member is supported and slides in a bearing and has a flexible membrane, which is disposed near the periphery of the housing in which the axial oscillating member is positioned. The latter supports a cupped glass element which is in cooperation with the flexible membrane. A part of the housing defines a variable volume chamber which communicates with the exterior through an admission valve and with an outer tube. The valve is constituted by a central chamber, which communicates with the variable volume chamber, through a movement of the cupped glass element positioned in the extremity of the axial member, and with the exterior through the opening. A second cupped glass is positioned on the wall of the valve. In the conventional structure of the pump, the fixed electric bobbin is placed in the interior of the housing and covered with resin; under these conditions the bobbin warms up to the level which is above optimal level. SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved vibratory pump. This and other objects of the invention are attained by a pump in which the static part of the bobbin is positioned in a water refrigeration chamber which ensures the maintenance of the temperature of the bobbin within the acceptable limits. In the conventional pump of the foregoing type the adjacent extremities of the housing are linked to each other by the connection of external flanges to each other. This solution requires, however, an enormous number of screws to be tightened and untightened each time it is necessary to open or close the pump in the maintenance work and the like; such operation is considered to be annoying and should be eliminated. Furthermore, the main membrane in the conventional pump is formed by an extension that projects from the lower part of the water chamber to a connection region between the upper and lower parts of the housing, where a flange is coupled to a profiled tooth of the upper part and a flange of the bearing of the central oscillating member, which is interconnected between the flanges of the parts of the housing. It is another object of the invention to substantially simplify maintenance operations for the vibratory pump. These and other objects of the invention are attained by a vibratory pump, comprising a housing being substantially cylindrical, said housing including an upper part and a lower part connected to each other; connection means for connecting said lower and upper part to each other; a static electric bobbin covered with resin; a movable electric bobbin on which said static electric bobbin acts; an axial oscillating member supporting said movable bobbin; a bearing supporting said oscillating member; a main membrane supported on said oscillating member and having a periphery set close to an internal face of the housing and in cooperation with the housing defining a variable volume chamber, said lower part of the housing having a cooling chamber filled with water and accomodating said static electric bobbin; an admission central valve connected to said chamber and also to means which provides the cooling chamber with water; a stainless steel membrane having a periphery set in an internal face of said lower part of the housing and positioned between the static electric bobbin and the movable electric bobbin, said lower part having openings which are in communication with the said cooling chamber and with an exterior of the pump, said connection means including a flange region formed in the lower part of the housing and a flange formed on the upper part of the housing, said flange region being spaced from a wall of the upper part by an annular space, a profiled ring accomodated in said space near said flange and coupled to the said flange region by thread means and said ring having on a face thereof a plurality of circular grooves; and a plurality of radial triangular wings circumferentially spaced from each other. The main membrane may have a profiled flange which is fixed between a tooth formed on the upper part of the housing and a ring which is disposed on the bearing of the oscillating member. The static electric bobbin may have a cover fixed in the lower part of the housing by ultrasonic soldering. The admission valve may include an assembly ring provided with a screw thread screwed in an internal surface of the upper part of the housing and a flexible rubber ring having an internal rim, said assembly ring having an external rim on which is set the internal rim of a flexible rubber ring, said upper part having openings for water entry to said chamber, said rubber ring being adapted to cover said openings. The assembly ring may have an internal rim and an elongated cup-shaped portion co-axial to the assembly ring and having a central opening, and further including a rubber cup-shaped membrane and a pin received in said opening, said membrane being received and adjusted in an internal part of the cup-shaped portion of the assembly ring; said membrane having a lateral wall which covers a wall of the portion of the assembly ring, through which water contained in the chamber flows to an outlet of the pump. The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top plan view of the pump; FIG. 2 is an axial sectional view through the pump; FIG. 3 is a plan view of a detail of connection means between two housing parts; FIG. 4 shows a section B--B of FIG. 3 and illustrates connection means between the parts of the housing in further detail; FIG. 5 shows a view from arrow C of FIG. 4; FIG. 6 is a sectional view of the admission and emission valve of the vibratory pump with separated parts; and FIG. 7 is a sectional view of the valve in the assembled condition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in detail, a vibratory pump of this invention includes an essentially cylindrical housing made of synthetic material or the like and having a lower part 1 and an upper part 2 connected to each other by means of connection 3. Housing 1, 2 accommodates in its lower part 1, a static electric bobbin 4 covered with synthetic resin 5. Bobbin 4 acts on a movable bobbin 6 positioned in the interior extremity of an oscillating member 7. The latter is disposed axially in the housing 1, 2. Oscillating member 7 is capable of sliding in a bearing 8 supported between parts 1 and 2 of the housing. The oscillating member 7 is supported by a main membrane 9 which limits, in cooperation with the upper part of the housing, a chamber of variable volume 10 which communicates with a central admission valve 11 and with a duct 12; the admission valve has a chamber communicating through opening 14 with the chamber of variable volume 10 in which a flexible cupped glass element 13 is positioned. A second upper cupped glass element 15 which acts on the opening 14 is positioned on the wall defining the admission valve chamber. The first embodiment of the vibratory pump includes a refrigeration chamber 16. The lower part 1 of the housing is divided by a stainless steel membrane 17 which is disposed between the static electric bobbin 4 and the movable electric bobbin 6. Membrane 17 separates an upper region or chamber from refrigeration chamber 16. The latter is filled with water which surrounds the static electric bobbin 4 and communicates with exterior by means 19. The connection 3 between the lower part 1 of the housing and its upper part of 2 is formed by a relatively short portion 20 of the lower part 1 in which an external flange 21 of the upper part of the housing is fitted. Flange 21 is formed so that a space is formed between the external surface of the upper part 2 of the housing near the flange and the internal surface of the portion 2. A ring 22 is received in this space. Flange 20 is coupled to ring 22 by a screw thread 23. Connection 3 can alternatively be formed by radial pins 25 (FIG. 4) which are projections extending from the ring external face. Pins 25 are engaged in corresponding grooves 26 formed in the internal face of the portion 20. These grooves 26 have the "L" shape and have each a portion extending in longitudinal direction of the pump and a perpendicular region 27 in the circumferential part of the housing. The profiled ring (22) is provided with grooves 28 (FIGS. 1, 4) and has radial triangular vanes 29 responsible for the ring movement in the opening and closing operations. The vibratory pump further includes a main membrane 9 which is formed with a profiled flange 30-31 which is clamped between a tooth formed on a part 33 of the upper part 2 of the housing and a ring 34 which is positioned on a bearing of the oscillating member 7. The resin cover 5 of the static electric bobbin 4 is connected to housing parts 1, 2 by ultrasound soldering or other means 35 and it can be substituted by electrostatic covering to enlarge the refrigeration area. Membrane 17 as well as other structural parts are fixed in the housing, for example by auto-gluing means 36. The admission valve 11 may be formed as valve 37 (FIGS. 6 and 7). Valve 37 has a ring 38 which is provided with a screw thread 39 that is screwed in a corresponding screw thread 40 formed in an outlet portion 12 of the housing part 2. The ring 38 has an external rim 41 on which in assembly is positioned an internal rim 42 of a membrane 43 of a flexible rubber ring type. Openings 44 in the upper housing part serve for the entry of water into the variable volume chamber 10. An internal rim 45 is provided on ring 38. A cup-shaped region 46 co-axial to the assembly ring 38 has a projection 47 which has a central opening 48 in which a pin 49 of a cup-shaped flexible rubber membrane 50 is received. Pin 49 is adjusted in the internal region of portion 46 of the assembly ring 38; the flexible rubber membrane 50 has a peripheral wall 51 which covers openings 52 which are formed in the wall 53 of the cup-shaped portion 46 of the assembly ring 38, through which openings water contained in the chamber 10 passes to the outlet of the pump. When the axial oscillating member 7 of the pump is lowered it enlarges the volume of chamber 10 and causes a depression in the internal part of the chamber, which in turn causes the flexible rubber ring 43 to open the openings 44 and the consequent entry of a portion of water into the chamber 10 and simultaneously, causes the compression of wall 51 of flexible rubber membrane 50, which wall meets the outlet openings 52 of the water chamber 10, and closes those openings. When the axial member 7 ascends it reduces the capacity of the chamber and causes the compression of the flexible rubber ring 43 which meets the openings 44 which are closed, and simultaneously causes the compression of the flexible rubber ring 50 which opens the openings 52 through which a part of water of the chamber 10 passes to the outlet or duct 12. It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of vibratory pumps differing from the types described above. While the invention has been illustrated and described as embodied in a vibratory pump, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

A vibratory pump comprises a skeleton composed by an interior part and an exterior part interlinked by a connection with a movable static bobbin covered with resin that acts on a main membrane that in cooperation with a skeleton delimits a variable volume repression chamber communication with the exterior part through an admission central valve and also acts with a repression duct.

CROSS REFERENCE TO RELATED APPLICATION This application is a continuation of U.S. application Ser. No. 11/284,379, filed Nov. 21, 2005, which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to method of producing hydrofluorocarbons, and particularly lower alkyl hydrofluorocarbons, from hydrochlorocarbons. 2. Description of Related Art It is known that when certain halocarbons are released into the atmosphere, they undergo reactions that result in the depletion of the Earth's ozone layer. Examples of environmentally harmful halocarbons include certain hydrochlorocarbons (HCCs), hydrochlorofluorocarbons (HCFCs), and chlorofluorocarbons (CFCs). One such CFC is trichlorofluoromethane (CFC-11), a compound that conventionally has been used in foam insulation applications. Due to CFC-11's potential for environmental damage, replacements for this compound have been sought. One proposed substitute for CFC-11 in foaming application is 1,1-dichloro-1-fluoroethane (HCFC-141b). Although HCFC-141b also adversely affects the ozone layer, its impact is significantly less than that of CFC-11. Certain lower alkyl hydrofluorocarbons, including the compound 1,1,1,3,3-pentafluoropropane (HFC-245fa), have been identified as a potential replacements for HCFC-141b in a variety of applications, most notably insulation and refrigeration applications. HFC-245fa has good insulation characteristics, low toxicity, correct vapor pressure and low flammability properties. Accordingly the demand for HFC-245fa has grown and as well as a need for more economical means of producing compounds such as HFC-245fa. Methods for producing hydrofluorocarbons (HFCs) by reacting hydrogen fluoride (HF) with various hydrochlorocarbon and/or hydrochlorofluorocarbon compounds are known. For example, various schemes for producing HFC-245fa from 1,1,1,3,3-pentachloropropane (HCC-240fa) or 1,3,3,3-tetrachloro-1-propene (HCC-1230) and hydrogen fluoride (HF) either in the liquid or vapor phase have been described. See, for example, U.S. Pat. Nos. 5,902,912 and 5,710,352. For liquid phase processes, a catalyst such as SbCl 5 or SbF 3 Cl 2 is usually required to promote the exchange of chlorine atoms on the organic reactant with fluorine atoms of the hydrogen fluoride reactant. Unfortunately, the reaction conditions (e.g. reactant and catalyst concentrations, temperatures, pressures and the need for oxidants such as chlorine to maintain catalyst activity) required to promote this halogen exchange process can be extremely corrosive to metals commonly used for liquid phase reactors, such as Monel, Inconel and Hastelloy C. As a result of the extremely corrosive reaction environment most reactors used for fluorination processes must be lined with fluoropolymers. However, these lined reactors suffer from poor heat transfer and HF permeation of the liner. In addition, the use of Cl 2 as an oxidant results in a yield loss due to chlorination of various raw materials, intermediates, and reactants. SUMMARY OF THE INVENTION Applicants have discovered advantageous methods for preparing alkyl hydrofluorocarbons, such as C2-C4 hydrofluorocarbons, and preferably HFC-245fa. In preferred embodiments the methods include liquid phase reactions which overcome many of the disadvantages of prior processes, including the many of the problems mentioned herein. In one preferred aspect, applicants have discovered that HFC-245fa can be employed as a solvent for a superacid system in which HFC-245fa can also be prepared at commercially viable production rates and under conditions that are not corrosive to metals such as Hastelloy C. The preferred methods of the present invention utilize a reaction system (eg., reactants, solvent, acid, and catalyst) capable of achieving low to negligible corrosion rates with respect to certain metals and alloys, while also achieving productivities (defined as amount of product made per unit of time per unit volume of reaction mass) equal to or greater than systems which employ corrosive “conventional” halide exchange liquid phase reaction systems (e.g. high concentration SbCl 5 ). The preferred method and systems of the present invention can thus utilize reactors constructed with contact materials having greater heat transfer rates (eg., metals) as compared to fluoropolymer lined reactors which are necessitated by the highly corrosive conventional liquid phase reaction systems. In addition, the preferred aspects of the present invention can be in the form of continuous production methods and systems using equipment configurations similar to those currently employed in the production of other HCFC and HFC compounds such as chlorodifluoromethane (HCFC-22), 1,1-dichloro-1-fluoroethane (HCFC-141b), and 1,1,1-trifluoroethane (HCFC-143a). According to preferred aspects of the present invention, at least one non-fluorinated hydrochlorocarbon, such as HCC-240fa and/or HCC-1230, is added to a solution comprising: (a) a solvent (preferably C2-C4 hydrofluorocarbon solvent, more preferably C3 hydrofluorocarbon solvent, and even more preferably HFC-245fa solvent); (b) a fluorinating agent (such as HF); and (c) a fluorination catalyst, such as a metal pentafluoride under conditions effective to produce the desired C2-C4 hydrofluorocarbon reaction product, preferably HFC-245fa. Although not wanting to be bound to any particular theory, it is thought that when a fluorinating agent, particularly HF, reacts in the presence of metal halide catalyst, such as SbF 5 , TaF 5 , and NbF 5 , an exothermic reaction occurs to form a superacid system. It is believed that this reaction may occur according to the following reaction scheme: 2 HF+MF 5 →[H 2 F] (+) [MF 6 ] (−) The higher Lewis acidity of super-acids such as anhydrous hexafluoroantiminic acid (HSbF 6 ), anhydrous hexafluorotantalic acid (HTaF 6 ), or anhydrous hexafluoroniobic acid (HNbF 6 ) relative to conventional acid catalysts such as “HSbCl 5 F” and “HSbF 4 Cl 2 ” (as measured by the Hammet scale) allow for lower concentrations of catalyst to be employed while still achieving similar productivity. In addition, the reaction mechanism may be different than the “Swarts” reaction based systems which are presumably dominant under conditions of high SbCl 5 concentration and low HF concentration. Moreover, compared to conventional acid catalysts, fully fluorinated superacids require much less, if any, oxidants (such as chlorine) to maintain their activity, thus further lowering yield losses due to the presence of Cl 2 in the reaction system and further lowering the corrosive tendency of the reaction system. The corrosion of reactors which use lower concentrations of fully fluorinated superacid catalyst is considerably less compared to conventional high SbCl 5 concentration system. The latter has been demonstrated to be very corrosive to metals such as Hastelloy C and Monel 400. Also, the low catalyst concentration system of certain preferred aspects of the present invention has other benefits, such as the low viscosity and the presence of only one liquid phase in the reactor. One preferred aspect of the present invention provides methods of producing C2-C4 hydrofluorcarbons, preferably 1,1,1,3,3-pentafluoropropane, comprising: (a) providing a solution comprising a metal halide fluorination catalyst at least partially dissolved in an azeotrope-like mixture of 1,1,1,3,3-pentafluoropropane and hydrogen fluoride; and (b) adding to the solution at least one non-fluorinated HCC to form a liquid reaction system under conditions effective to convert at least a portion, and preferably a substantial portion, of said non-fluorinated HCC (preferably by reaction of said HCC with said HF) to the desired C2-C4 hydrofluorcarbon, preferably 1,1,1,3,3-pentafluoropropane. In certain preferred embodiments, the present invention provides a continuous process for the preparation of HFC-245fa which comprises continuously introducing a stream comprising C3 hydrochlorocarbon, preferably 1,1,1,3,3-pentachloropropane, 1,3,3,3-tetrachloro-1-propene or combinations of these into a reactor containing a solution of HFC-245fa, HF, and a metal halide fluorination catalyst selected from the group consisting of SbF 5 , NbF 5 , TaF 5 and mixtures of TaF 5 and SnF 4 under conditions which produce HFC-245fa. Preferably the process also includes the step of introducing anhydrous hydrogen fluoride into said reaction system. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a schematic representation of an embodiment of the present invention wherein a desired HFC (such as HFC-245fa) is produced via a continuous process. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Preferred aspects of the present invention provide for the catalytic, liquid phase fluorination of at least one non-fluorinated hydrochlorocarbon, such as HCC-240fa, HCC-1230, or a mixture of HCC-240fa and HCC-1230, with HF, wherein the reaction product and the solvent for the reaction are both HFC-245fa. In certain embodiments of the invention, a solution of HFC-245fa, HF and catalyst is first prepared in a fluorination reactor. The reactor according to such preferred aspects of the invention may be any suitable fluorination reaction pressure vessel or autoclave which is constructed from materials that are resistant to the corrosive effects of hydrogen fluoride at the temperatures and pressures of the reaction, such as Hastelloy C, Monel, Inconel, Molybdenum or fluoropolymer lined steel. After this solution is prepared and the reactor is brought to the desired temperature and pressure, the hydrochlorocarbon and HF are fed into the reactor, preferably substantially simultaneously. Preferred liquid phase metal halide catalysts for this reaction are SbF 5 , NbF 5 , TaF 5 , mixtures of TaF 5 and SnF 4 , and some combination thereof. At the preferred concentrations and temperatures employed in this reaction, the HFC-245fa, HF, and catalyst are preferably completely, or at least mostly, miscible. The exothermic reaction between the HF and metal halide preferably occurs to form a superacid, presumably according to the following scheme: 2 HF+MF 5 →[H 2 F] (+) [MF 6 ] (−) The reaction mixture is then preferably brought to reaction temperature and pressure conditions such that the HF/HFC-245fa azeotrope-like composition is formed, and preferably begins to reflux. As used herein the term “azeotrope-like” refers, in a broad sense, to compositions that are strictly azeotropic and compositions that behave like azeotropic mixtures. From fundamental principles, the thermodynamic state of & fluid is defined by pressure, temperature, liquid composition, and vapor composition. An azeotropic mixture is a system of two or more components in which the liquid composition and vapor composition are equal at the state pressure and temperature. In practice, this means that the components of an azeotropic mixture are constant boiling and cannot be separated during a phase change. Thus, “azeotrope-like” compositions are constant boiling or essentially constant boiling. In other words, for azeotrope-like compositions, the composition of the vapor formed during boiling or evaporation is identical, or substantially identical, to the original liquid composition. Thus, with boiling or evaporation, the liquid composition changes, if at all, only to a minimal or negligible extent. This is to be contrasted with non-azeotrope-like compositions in which, during boiling or evaporation, the liquid composition changes to a substantial degree. Another characteristic of azotrope-like compositions is that there is a range of compositions containing the same components in varying proportions that are azeotrope-like or constant boiling. All such compositions are intended to be covered by the terms “azeotrope-like” and “constant boiling”. For example, it is well known that at differing pressures, the composition of a given azeotrope will vary at least slightly, as does the boiling point of the composition. Thus, an azeotrope of A and B represents a unique type of relationship, but with a variable composition depending on temperature and/or pressure. It follows that, for azeotrope-like compositions, there is a range of compositions containing the same components in varying proportions that are azeotrope-like. All such compositions are intended to be covered by the term azeotrope-like as used herein. The reactor in accordance with preferred aspects of the present invention is preferably maintained at a temperature of from about 60° C. to 120° C., more preferably from about 70° C. to 110° C., and even more preferably from about 80° C. to 100° C. The reactor pressure is preferentially maintained at the vapor pressure of the HF/HFC-245fa azeotrope-like composition, which is largely determined by the temperature of the reactor system as well as its composition. The HF/HFC-245fa azeotrope-like vapor pressure characteristics and compositions are described in U.S. Pat. No. 6,001,796, which is incorporated herein by reference. Preferred non-fluorinated hydrochlorocarbons include, HCC-240fa, HCC-1230, and combinations thereof. Without being bound by or to any particular theory of operation, it is believed that when these reactants are used the overall net reactions are as follows: HCC-240fa CCl 3 —CH 2 —CH 2 Cl+5 HF→CF 3 —CH 2 —CF 2 H+5HCl HCC-1230 CCl 3 —CH═CHCl+5 HF→CF 3 —CH 2 —CF 2 H+4HCl During the latter parts of the reactions, it is believed that certain volatile intermediates are formed which can be separated from the reaction product and returned back to the reactor in order to be converted into the HFC-245fa product, which has a boiling point of 15° C. at 1 atmosphere of pressure. These intermediates include, but are not limited to, the following compounds: 1,3,3,3-tetrfluoro-1-chloropropane (HCFC-244) nbp=39° C. 3,3,3-trifluoro-1-chloropropene (HCFC-1233) nbp=21° C. 1,3,3,3-tetrafluoro-1-propene (HFC-1234) nbp=−19° C. The preferred net molar feed ratio of HF to HCC (preferably HCC-240, HCC-1230, or some combination thereof) is from about 3:1 to about 8:1, more preferably from about 4:1 to about 6:1, and even more preferably in certain embodiments about 5:1. Since some HF may be lost from the reaction system via carryover with the HCl byproduct, this loss is preferably compensated for by raising the feed ratio accordingly. A significantly higher ratio could result in the gradual accumulation of HF in the reactor, while a significantly lower net ratio could result in the gradual depletion of HF in the reactor. Of course, the exact amount of HF in the feed can be controlled by monitoring the amount of HF in the reaction product in accordance with known techniques. Preferably, the mole ratio of HF to HCC-230 and/or HCC-1230 in the reaction system is greater than about 10:1. The mole ratio of HF:HFC-245fa in the reactor is preferably not more than about 12:1, more preferably not more than about 8:1, and most preferably about 6:1. The amount of catalyst in the reactor can vary within the broad scope of the present invention depending upon numerous factors, including the trade-off between increased production and the potential increase in corrosion. The amount of catalyst preferably ranges from about 0.5 wt % to about 10 wt % of the starting mixture, more preferably from about 1 wt % to about 5 wt % and most preferably from about 2 wt % to about 4 wt %. The molar ratio of HF to catalyst initially present and prior to the HCC addition is preferably at least about 10:1, more preferably at least about 20:1, and even more preferably at least about 40:1. The amount of HFC-245fa solvent present in the reaction mixture at steady state preferably ranges from about 40 to about 80 wt %, more preferably from about 45 to about 70 wt %, and even more preferably from about 50 to about 60 wt %. In certain preferred embodiments, the solvent is put into the reaction vessel at startup and preferably maintained within acceptable levels, which in preferred embodiments is substantially constant amount, by removal of HFC-245fa as it is generated. Due to the azeotrope-like composition formed by HF and the product/solvent, any HF lost is preferably replaced by additional HF input. This loss can arise when a portion of the HF/HFC-245fa azeotrope-like composition is removed from the reactor so that at least a part of the HFC-245fa can be separated as a product. Any suitable means can be used to separate HFC-245fa from the azeotrope-like composition, including the extraction of HF from the azeotrope-like composition by concentrated sulfuric acid. HFC-245fa has very limited miscibility in H 2 SO 4 relative to HF, and the resulting HF—H 2 SO 4 solution can be heated to distill off the HF, which can then be returned to the reactor as a recycle stream. The preferred feed rate of HCC-240fa or HCC-1230 ranges from about 0.1 to about 10 lbs/gallon-hour based upon the total volume of liquids in the reactor. A more preferred range is from about 1 to about 5 lbs/gallon-hour, while the most preferred range is from about 2 to about 4 lbs/gallon-hour. In certain preferred embodiments, the unreacted hydrochlorocarbons, such as HCC-230, and partially fluorinated intermediates are volatilized from the liquid reaction mixture, along with HF and the HF/HFC-245fa azeotrope-like composition, and then recycled back to the to the reactor for further fluorination. In general, almost all of the intermediates are less volatile than the product, and therefore this recycle of higher boiling materials (with the exception of HFC-1234) is easily effected by fractional distillation techniques well known to those skilled in the art. This continuous production process can utilize several features of existing liquid phase HF reaction processes, including a pressure reactor connected to a continuous fractional distillation column or series of columns. FIG. 1 depicts one preferred embodiment of this invention wherein a reactor is maintained at a constant level and composition by feeding HF, chlorinated feed and recycled organics into the reaction vessel R-1 at a rate that the chlorinated materials will be converted into the desired product, such as the preferred HFC-245fa. In addition to the HF and organic feeds, small amounts of desiccants, such as SOCl 2 , COCl 2 or COF 2 may be added in order to remove any trace amounts of water that would enter the reaction system. For example, HF may contain 500 ppm H 2 O, which, over time, can accumulate in the reboiler if not removed (e.g. by a reaction that consumes the water molecules). The vapor outputs from the reactor, consisting mostly of HCl, the HF/HFC-245fa azeotrope-like composition, and various smaller amounts of intermediates and feedstock, are preferably directed to a fractional distillation column T-1, where most of the higher boiling compounds are condensed/refluxed back to the reactor. The vapor stream leaving the partial condenser of T-1 is then preferably fed to another column T-2, under conditions so that the by-product HCl is refluxed and vented off for either collection or neutralization. The higher boiling materials from the reboiler of column T-2 can then be fed to another column T-3, wherein the remaining trace intermediates, such as HFC-1234, are preferably distilled-off and recycled back to the reactor, while higher boiling compounds that accumulate are preferably then fed to column T-4. In this T-4 distillation column, when present, the HFC-245fa/HF azeotrope-like composition (which generally comprises from about 22 wt % HF/88 wt % HFC-245fa) is preferably distilled off and transferred to the HF extraction unit while the accumulated higher boiling compounds such as HCFC-244 and HCFC-1233 are fed back to the reactor, preferably at rates equal to their accumulation. The HF/HFC-245fa vapor stream leaving the top of T-4 (via the partial condenser) is then preferably fed to an HF extraction column, where the HF present in the vapor azeotrope-like composition is extracted by a fluid such as sulfuric acid or fluorosulfonic acid. The crude HFC-245fa is then collected and, if desired, further purified to yield the desired product. In many preferred embodiments it is highly desired that the catalyst and the HCC material(s) not be allowed to contact each other except in the presence of a molar excess of HF in order to inhibit or substantially prevent catalyst deactivation. Such a deactivation may occur by a process known as the Swarts reaction, resulting in a chlorinated metal halide that possesses a significantly lower (Lewis) acidity, as measured via the Hammet scale. An example of the undesired Swarts reaction would be as follows: CCl 3 —CH 2 —CHCl 2 +SbF 5 →CF 3 —CH 2 —CCl 2 H+SbF 3 Cl 2 In contrast, the preferred reaction mechanism according to the present invention is believed to be represented as follows: R—Cl+[H 2 F][SbF 6 ][R (+) ][SbF 6 ] (−) +HCl+HF [R (+) ][SbF 6 ] (−) +2HF→R—F+[H 2 F][SbF 6 ] The HCl byproduct is preferentially vented off from the system and either condensed with a low temperature coolant in a second distillation system, or neutralized with an appropriate base such as NaOH or CaCO 3 . If the HCl by-product is to be neutralized, the high pressure gas (at a range of 100 to 300 psig) can be used as a source of refrigeration as it is expanded from the cold high pressure state to atmospheric pressure. This would reduce the energy consumption of the process, as there is a considerable amount of HCl made from the conversion of HCC-240 into HFC-245fa (1.36 lbs HCl/lb HFC-245fa). The present mechanism differs from the Swarts reaction, even though the end result is similar. The Swarts reaction, which can take place even in the absence of HF, occurs as follows: R ⁢ - ⁢ C ⁢ ⁢ l + SbF ( 5 - x ) ⁢ C ⁢ ⁢ l ( x ) → [ R ( + ) ] ⁡ [ SbF ( 5 - x ) ⁢ Cl ( x + 1 ) ( - ) ] ⁢ → R ⁢ - ⁢ F + SbF ( 4 - x ) ⁢ Cl ( x + 1 ) x = 0 , 1 , 2 , 3 ⁢ ⁢ or ⁢ ⁢ 4 In practice, the Swarts catalyst can be regenerated with HF: Sb (4−x) Cl (x+1) +HF→SbF (5−x) Cl (x) +HCl The by-product HCl formed, is easily distilled away from the re-generated Swarts catalyst due to its low boiling point (nbp=−83° C.) versus the normal boiling point of HF (nbp=+20° C.). This catalyst can also decompose into the +3 valency by eliminating Cl 2 ; for example: SbF 3 Cl 2 →SbF 3 +Cl 2 This is a temperature related equilibrium reaction (increasing dramatically as the temperature rises from 75° C.) that needs to be reversed by the addition of Cl 2 into the reaction system. The Sb +3 halides are ineffective as halogen exchange catalysts with HCCs/HFCs. According to certain preferred embodiments, the reaction process has a first step wherein a carefully maintained ratio of HF to HCC (such as HCC-240fa, HCC-1234 or combinations of these) is fed into a reactor after a HFC-245fa/HF/catalyst system is refluxing at the correct temperature and pressure, for example in column T-1. As the system approaches steady state, recycled organic feeds and recycled HF can be sent back to the reactor; as this occurs, the HF:organic feed ratio can be trimmed back to a mole ratio of about 5:1. This method is preferred because the vapor exiting the initial column would contain HCl, HFC-245fa, and HF in a molar ratio of approximately 5:1:1.68, and thus depleting the HF in the reactor, leading to the possibility of increased corrosion as the net molar ratio of catalyst to HF increases towards undesirable levels. Since both the HF and organic feed might contain a small but significant amount of water (500 ppm with the HF, <50 ppm for the organic), a dehydrating agent such as SOCl 2 or COF 2 can be added in small amounts depending upon the amount of water present in these feeds. Water may act as a base in the system, decreasing the acidity of the system as measured on the Hammet scale. Since CO 2 and HCl have very similar vapor pressures, the use of dehydrating agents that also produce CO 2 are preferred because the CO 2 can then be easily vented off from the system along with the HCl at the top of column T-2. The liquid accumulated in the reboiler of column T-2 is then be sent to column T-3, where the small amounts of more volatile organic intermediates can be separated from the HFC-245fa and HF. The HF/HFC-245fa enriched mixture that accumulates in the reboiler of column T-3 is then be sent to column T-4, where the HF/HFC-245fa is distilled away from higher boiling intermediates such as HCFC-244 and these higher boiling compounds are then sent back to the reactor at a rate equal to their accumulation in the reboiler. The HF/HFC-245fa azeotrope-like composition can exit from the top of column T-4 and be vented into the HF extraction unit. The purified vapor leaving the top of this extraction column (the extraction column where concentrated H 2 SO 4 is added in a counter-current fashion) is then be condensed and accumulated prior to any further purification steps—for example the removal of trace HF and trace amounts of unsaturated compounds, such as CF 3 —CH═CClH and CF 3 —CH═CFH. The resulting sulfuric acid-HF-fluorosulfonic acid solution leaving the bottom of the extraction column is then sent to a reboiler where the majority of the HF would be fractionally distilled away from the H 2 SO 4 —HSO 3 F solution. The HF distillate can be condensed and recycled back to the HCFC synthesis reactor, while the HF depleted hot H 2 SO 4 solution can be sent back to the extraction column T-4 after being cooled. The small amount of HFC-245fa and volatile unsaturated compounds contained in the distilled HF can also be included in this recycle stream. At this point, an HFC-245fa product having a purity at least about 99% is achievable. EXAMPLES The following non-limiting examples serve to illustrate certain aspects of the invention. Example 1 Into a stirred 600 ml Hastelloy C autoclave was added 7.0 gram (0.032 gram-mole) of SbF 5 and 56.7 grams anhydrous HF (2.84 gram-moles). Next, 85.9 grams of HFC-245fa (0.642 mole) was added, followed by 48.5 grams (0.224 mole) of HCC-240fa. The mixture was then pressurized with N 2 to 170 psig, and then heated to about 120° C. over a 1 hour period and maintained at this temperature for an additional 2.5 hours. The bulk of the reaction took place in 34 minutes, as indicated by the amount of HCl byproduct vented from the system. The starting mole ratio of HF to HFC-245fa to SbF 5 was 88:19.8:1. Due to the evolution of HCl, the pressure rose significantly above the HF/HFC-245fa autogeneous pressure, and gas from the autoclave at a pressure greater than 400 psig was vented through a KOH scrubber/dryer and into a liquid nitrogen chilled collection cylinder over a 34 minute period. In this acid removing scrubber, a considerable amount of the product underwent a dehydrohalogenation reaction (forming the HFC-1234). The gas evolution ceased after the first hour, and was bled to atmospheric pressure at the end of the experiment. A total of 106.4 grams of organic was collected in the receiver with the following composition: 85.7% HFC-245fa, 9.4% HFC-1234, 2.52% HCFC-1233 and 1.48% HCFC-244 (the latter 3 compounds are intermediates in the synthesis of HFC-245fa). The net yield of product and formation of HFC-1234 byproduct, based upon the HCC-240 consumed, was 42.4% and 42.4%, respectively. There was no visible corrosion observed in this reaction, where the maximum temperature was 121° C. (560 psig. The net substitution of fluorine for chlorine on the organic feed was 98.1%. The reactor productivity was 2.5 lbs HFC-245fa/gallon-hr and 2.15 lbs HFC-1234/gallon-hr. When the HFC-245fa and HFC-1234 are treated as all HFC-245fa (HFC-245fa+KOH→HFC-1234+KF+H 2 O), the productivity would be near 5 lbs/gallon-hour. Comparative Example 2 This example demonstrates the corrosion rate of a SbCl 5 /HF system on equipment that can be used to produce HFC-245fa. Into a stirred Hastelloy C autoclave was added 299 parts SbCl 5 (1 mole) and 60 parts HF (3 mole). The mixture was heated to 80° C. for 4 hours in preparation for the addition of HCC-240fa and Cl 2 , when HF was observed to be leaking from the autoclave. The corrosion rate was approximately 0.06 inches/hour on the baffle/thermowell, and even greater on the agitator blades, where the fluid velocities were greatest. Example 3 A corrosion study was performed on an HF/SbF 5 /HFC-245fa system at 90° C. upon various metals and alloys. Using a solution of 5 wt % SbF 5 , 47.7 wt % HF and 47.3 wt % HFC-245fa, the corrosion rate for Hastelloy C, Inconel 600, Incoloy 825, Monel 400, SS 316 and C1018 carbon steel. The results of this example are provided in Table 1. TABLE 1 Materials of Construction Corrosion Rate (mils/year) Hastelloy C 0 Inconel 600 27 Incoloy 825 9 Monel 400 30 SS 316 21 C1018 carbon steel 96 Having thus described a few particular embodiments of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements, as are made obvious by this disclosure, are intended to be part of this description though not expressly stated herein, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and not limiting. The invention is limited only as defined in the following claims and equivalents thereto.

A process for the production of C2-C4 hydrofluorocarbon, such as 1,1,1,3,3-pentafluoropropane, by contacting a non-fluorinated hydrochlorocarbon with a fluorinating agent, such as hydrogen fluoride, in a liquid catalyst system preferably comprising fluorinated superacid catalyst prepared from SbF 5 , NbF 5 , TaF 5 or TaF 5 /SnF 4 and HF.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a capping apparatus for capping containers, such as bottles, and, in particular, to a constant-torque capping apparatus capable of capping a container at a predetermined tightening torque accurately at all times. This invention is related to U.S. Pat. No. 4,535,583 issued Aug. 20, 1985, entitled "Rotary Type Capping Apparatus". 2. Description of the Prior Art Typically, a prior art capping apparatus includes a turn table having a plurality of container holders disposed along the periphery of the turn table and a plurality of capping heads which are each provided corresponding in position to the container holders and driven to move along a circular path together with the turn table. Each of the capping heads has a cap holder which releasably holds a cap at its bottom and which is driven to rotate so as to have the cap screwed onto the mouth of the container held by the corresponding container holder on the turn table. In such a prior art capping apparatus, a sun gear is commonly provided as fixed in position and coaxial with a rotary shaft of the turn table and a plurality of pinions are provided in mesh with and disposed around the sun gear. Each of the pinions is fixedly provided on a driving shaft which is operatively connected to the corresponding cap holder so that the cap holder may be driven to rotate when the corresponding pinion moves around the sun gear in mesh therewith, thereby causing the cap held by the cap holder to be screwed onto the mouth of the corresponding container. In this prior art structure, a clutch is typically provided in a power transmitting system between the pinion and the cap holder and a slippage is induced in the clutch when the cap tightening force has reached a predetermined value. However, in such a prior art capping apparatus, since the rotation of each pinion around its own axis depends on the rotation of the turn table, a torque for screwing a cap onto a container is directly determined by the rotation of the turn table. As a result, if the rotation of the turn table varies for some reason, the screwing or tightening torque also varies accordingly. This has been found to be extremely disadvantageous because the rotational speed of the turn table is sometimes desired to be set at different levels to accomodate other processing stations in the same container handling line, such as a filling station where desired contents are filled in the containers and a labelling station where labels are glued onto the containers. Moreover, even if the capping apparatus itself is operated at constant speed, the magnitude of inertia torque applied to the cap at the final stage of the capping operation tends to fluctuate for various reasons so that there has been encountered a difficulty in maintaining the cap tightening torque at a constant value with high accuracy. SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to obviate the above-described disadvantages of the prior art and to provide an improved capping apparatus. Another object of the present invention is to provide an improved capping apparatus capable of capping containers, such as bottles, at predetermined tightening torque at high accuracy at all times. A still further object of the present invention is to provide an improved capping apparatus for having caps tightly screwed onto the mouth of containers at constant tightening torque one after another in a continuous manner. Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration showing the general flow of containers which are uncapped when supplied into a capping apparatus of the present invention and which are capped when discharged out of the capping apparatus; FIG. 2 is a schematic illustration showing partly in cross-section the overall structure of the capping apparatus constructed in accordance with one embodiment of the present invention; FIG. 3 is a schematic illustration showing the detailed structure of one of the capping heads of the capping apparatus shown in FIG. 2; and FIG. 4 is a timing chart which is useful for explaining the operation of the present capping apparatus shown in FIGS. 2 and 3. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, a capping apparatus 1 of the present invention receives containers 3 (see FIG. 2), such as bottles, as supplied from a transporting conveyor 2 via an inlet star wheel 4, and after having been capped within the capping apparatus 1, the containers 3 are discharged to another transporting conveyor 6 through an outlet star wheel 5. The detailed structure of these star wheels may be found in copending U.S. patent application, Ser. No. 06/537,465, which is also assigned to the assignee of this application and which is incorporated herein by reference. As illustrated in FIG. 2, the capping apparatus includes a fixed shaft 7 which extends vertically from a base of the apparatus, and a rotary cylinder 8 which is rotatably fitted onto the fixed shaft 7 from above. The rotary shaft 8 is operatively coupled to a motor 9, which is fixedly mounted on the base of the apparatus, and, thus, the rotary cylinder 8 may be driven to rotate around the fixed shaft 7 when driven by the motor 9. It is to be noted that although not shown specifically, the motor 9 is driven in a manner which controls the rotational speed of the rotary cylinder 8 in association with the operating speed at other associated stations, such as filling and labelling stations, which are disposed in the same container handling line as the present capping apparatus. A turn table 10 is provided as fixedly mounted on the rotary cylinder 8, and the turn table 10 is provided with a plurality of container holders 11 as arranged along the periphery thereof at an equally spaced interval. Also provided immediately above and integral with the rotary cylinder is a capping head assembly which includes a plurality of cap holders 13 corresponding in number to the container holders 11 and arranged above in registry in position with and movable closer to or away from the corresponding container holders 11 and torque motors 12 for driving to rotate the corresponding cap holders 13. The torque motors 12 are fixedly mounted on respective brackets 14, which are, in turn, slidably supported on guide rods 15 fixedly mounted on the rotary cylinder 8 and arranged therearound. And, thus, the brackets 14 are moved up and down as guided by the guide rods 15. A cam rail 16 having a predetermined shape is also provided as extending around the rotary cylinder 8 and fixed in position. The brackets 14 are engaged with the cam rail 16 so that the brackets 14 move up and down as guided not only by the guide rods 15 but also by the cam rail 16. As shown in FIG. 3, the cap holder 13 is fixedly attached at the bottom end of a driving shaft 20 which is operatively coupled to a rotary shaft 21 of torque motor 12 through a cylindrical connector 22, which is fixedly mounted on the rotary shaft 21 and which is formed with a longitudinal groove in its inner peripheral surface. At the top end of the driving shaft 20 is provided a key 24 which is loosely fitted into the groove 23. Thus, the driving shaft 20 is in sliding contact with the connector 22 and thus may be moved up and down within a predetermined range with respect to the connector 22 while maintaining a power transmitting relation between the torque motor 12 and the cap holder 13. Also provided is a stopper ring 25 fixedly mounted on the driving shaft 20. The stopper ring 25 determines the lowermost position of the cap holder 13 and prevents the driving shaft 20 from slipping away. The cap holder 13 is provided to temporarily hold a cap 29 to be tightly screwed onto the mouth of the container 3 which stands upright on the turn table 10 and is held in position by the container holder 11. As shown, the cap holder 13 is provided with a pressure chamber 30 a part of which is defined by a disc 31, which is forced to move downward when a pressurized gas is introduced into the pressure chamber 30. A ring-shaped elastic member 32 is also provided partly in contact with and below the disc 31, and the ring-shaped elastic member 32 has an opening whose diameter is slightly larger than the outer diameter of the cap 29 used. Since the disc 31 is provided with a circular ridge extending along the periphery at its bottom, the ridge is normally in contact with the ring-shaped elastic member 32, which is supported on a closure member provided with a center hole large enough for allowing the cap 29 to extend therethrough. Thus, when the disc 31 is pressed downward, the ring-shaped elastic member 32 deforms thereby making its opening smaller in diameter so that the cap 29 becomes temporarily held by the cap holder 13. The pressure chamber 30 is fluid-dynamically connectable to a pressure gas source 38 through passages 33, 34 and 35, conduit 36 and electromagnetic valve 37. It is to be noted that additional passages 39 and 40 are provided in the cap holder 13 from a point where the top surface of the cap 29 comes to be located when held by the ring-shaped elastic member 32 to the atmosphere, whereby the cap 29 is prevented from being stuck to the cap holder 13 due to creation of vacuum at its top. The torque motor 12 is provided with a r.p.m. detector 45, such as a rotary encoder, and, as shown in FIG. 2, the capping apparatus includes a position detector 46 for detecting the rotary position of the rotary cylinder 8 mounted on its machine housing. Lead lines 47 from the detectors 45 are connected to a control unit 50, such as a microcomputer, through a rotary joint 48, and a lead line 49 from the other detector 46 is directly connected to the control unit 50. The control unit 50 controls an output of each of the torque motors 12 and thus the level of torque for tightening the cap 29 by the cap holder 13 by adjusting the level of electric current supplied to each of the torque motors 12. And, as will be described later in detail, depending on the rotary position of the rotary cylinder 8, during a first stage of the capping operation, a torque applied to the cap 29 by the cap holder 13 is set at a first level which is larger than a predetermined reference level. During the second stage of the capping operation, the torque is set at a second level which is smaller than the predetermined reference level, followed by a third stage of the capping operation in which the torque is set at the predetermined reference level. With the above-described structure, when the rotary cylinder 8 is driven to rotate by the motor 9, the containers 3 standing on the transporting conveyor 2 still uncapped are lead into the corresponding container holders 11 on the turn table 10 one by one in sequence as regulated by the inlet star wheel 4 and temporarily secured in position on the turn table 10 standing upright. Meanwhile the caps 29 are supplied from a source (not shown) to be individually held by the cap holders 13 as indicated in FIG. 3. When cap 29 is inserted into the opening defined in the ring-shaped elastic member 32, a detection signal is supplied to the control unit 50 by means of a detector (not shown), and, thus, the control unit 50 supplies an activation signal to the electromagnetic valve 37 to have it energized thereby establishing the open condition. Thus, a gas under pressure is supplied into the pressure chamber 30 from the pressurized gas source 38, so that the ring-shaped elastic member 32 deforms thereby temporarily grabbing the cap 29 securely. FIG. 4 shows, from right to left, a progression of steps which occur during a revolution of turn table 10. First, cam rail 16 moves lower to a starting position S, remains low through steps A, B, and C, and rises again after ending position E. Before reaching the starting position S, with the uncapped container 3 securely held by the container holder 11 in position on the turn table 10 and the cap 29 securely held by the cap holder 13, the torque motor 12 and cap holder 13 gradually descend with the rotation of turn table 10 as guided by the cam rail 16 so that the cap 29 now securely held by the cap holder 13 comes to be fitted onto the mouth of the corresponding container 3. The torque motor 12 is maintained inoperative until it is brought to its lower predetermined position. As indicated in FIG. 4, when the detector 46 detects the condition that the rotary position of the rotary cylinder 8 is at a screwing operation initiation position S, i.e., the condition in which the torque motor 12 is located at its lowered position with the cap 29 becoming fitted onto the mouth of the corresponding container 3, the detector supplies a detection signal to the control unit 50, and, thus, the control unit 50 supplies a first driving signal to the torque motor 12 thereby causing it to be driven at a first torque G which is higher in level than a closure torque F having a predetermined reference level. The reason why the larger torque G is applied at the first stage of capping operation is to prevent the cap 29 from being improperly oriented, or inclined, with respect to the container 3 to be capped. That is, even if the cap 29 is initially inclined with respect to the mouth of the container 3 when brought into engagement by the downward motion of the cap holder 13, it can be properly oriented with respect to the mouth of the container 3 when driven at the larger torque G. The actual level of this larger driving torque G may be set advantageously in consideration of the material and shape of the cap 29. Position A on FIG. 4 is that position in the rotation of turn table 10 reached when cap 29 has rotated a single revolution. When the cap 29 has rotated a little more than a single revolution from the initial position S, the cap 29 necessarily becomes engaged with a threaded section of the mouth of the container 3, so that the control unit 50 now supplies a second driving signal to the torque motor 12 whereby the torque motor 12 is driven at a second torque H which is lower in level than the closure torque F. Assuming that the cap 29 has been rotated over a predetermined number of revolutions from the initial position S, the screwing operation for having the cap 29 screwed onto the mouth of the container 3 terminates at least at a position prior to position B indicated in FIG. 4 if the thread engagement between the cap 29 and the mouth of the container 3 is normal. At this time, the rotation of the cap 29 ceases as indicated by a one-dotted line I shown in FIG. 4. At this moment, even if an inertia torque due to rotation, which is higher in level than the torque H, is applied to the cap 29, no problem arises in the present invention as long as the final closure torque F is set larger than such an inertia torque. When the control unit 50 detects the fact that the cap 29 is not in rotation at position B by the detector 45, it supplies a third driving signal to the torque motor 12 so that the torque motor 12 becomes driven to rotate at the final closure torque F. Thus, the cap 29 can be tightly screwed onto the mouth of the container 3 always at the same torque level. Thereafter, when the control unit 50 detects the fact that the rotary cylinder 8 takes a position C indicated in FIG. 4, it causes the torque motor 12 to stop its rotation and to deenergize the electromagnetic valve 37 thereby releasing the cap 29 from the cap holder 13. Then, through the engagement with the cam rail 16, the cap holder 13 and torque motor 12 are returned to their original upper positions. Meanwhile, the container 3 now properly capped with the cap 29 is transferred from the container holder 11 to the transporting conveyor 6 via the outlet star wheel 5. If the detector 45 detects at position A the condition that the cap holder 13 is not in rotation, the control unit 50 is preferably so structured to supply an alarm signal for activating an alarm device (not shown). Or, alternatively, it may be so structured that the corresponding container 3 when released from the container holder 11 is transported to a predetermined location through an appropriate mechanism for eliminating the container 3 in question from the normal process line. On the other hand, if the cap holder 13 is detected to be in rotation at position B and also at position C, since this indicates a faulty condition, it is preferably so structured that the control unit 50 supplies an alarm signal or activates the above-described eliminating mechanism. In FIG. 4, a position E indicates the position which is determined to be prior to the position where the cap holder 13 and torque motor 12 return to their original upper positions through engagement with the cam rail 16 after a time period required for releasing the cap 29 by the cap holder 13. If the control operation by the control unit 50 still continues at position E for some reason, such as malfunctioning, its control operation is forcibly terminated thereby causing the cap 29 to be positively released from the cap holder 13. Instead of using the detector 46, there may be provided another detector for exclusively detecting this position E. In the above-described embodiment, the level of the torque at the torque motor 12 is directly controlled. However, the present invention is also applicable to the previously described sun gear-pinion combination if a multilevel clutch is provided in the power transmitting system between the sun gear and the pinion, in which the clutch adjusts the level of torque to be transmitted by an appropriate means, such as air pressure. In this case, the clutch transfers torques of different levels depending on the level of air pressure supplied thereto. While the above provides a full and complete disclosure of the present embodiments of the present invention, various modifications, alternate constructions and equivalents may be employed without departing from the true spirit and scope of the invention. Therefore, the above description and illustration should not be construed as limiting the scope of the invention, which is defined by the appended claims.

A capping apparatus includes a turn table which is supported to be rotatable and provided with a plurality of container holders for temporarily holding the containers securely, a plurality of cap holders for releasably holding caps to be screwed onto the mouth portion of the containers, a plurality of torque motors individually provided for rotating the corresponding cap holders and a microcomputer for controlling the level of torque applied to the cap holders by the torque motors. The torque applied to the cap holder during the screwing operation is set to be higher in level during the first revolution of the cap and lower in level during the remaining rotation of the cap than the torque applied upon completion of the screwing operation so that the caps can be screwed onto the threaded mouth portions of the containers all at the same tightening level.

This is a continuation of application Ser. No. 195,845, filed Oct. 10, 1980, now abandoned. BACKGROUND OF THE INVENTION The invention relates to a compound internal combustion and external combustion engine, and more particularly to a compound engine having working cylinders operated as a conventional internal combustion engine, preferably of the diesel-cycle type, co-operating with power cylinders of the external combustion type utilizing the normally wasted heat of the exhaust gases of the internal combustion working cylinders. It is known that the efficiency of internal combustion engines is somewhat poor, and that a great portion of the wasted energy appears in the form of heat which must be dissipated by means of sometimes complex, and always energy-wasteful, air or liquid fluid cooling systems. A great proportion of the energy wasted in the form of heat is in the exhaust gases. Diverse systems have been proposed in the past to recuperate, at least in part, the heat energy wasted in the exhaust systems of internal combustion engines, such as, for example, utilizing the flow of hot exhaust gases for driving a compressor or supercharger compressing the ambient air introduced into the air induction system of the engine, thus increasing the over-all efficiency of the engine. Other arrangements have been used in the past for utilizing directly or indirectly the heat lost in the exhaust of an internal combustion engine and for converting the heat to useful mechanical energy which is returned as driving power to the engine. For example, U.S. Pat. No. 951,171 contemplates an internal combustion engine driving an air compressor and utilizing the heat from the cooling system coolant and from the exhaust gases, through the coolant, to heat the air between the compressor and the inlet of a hot air cylinder to which the compressed air is supplied. U.S. Pat. No. 2,826,894 discloses vaporizing the coolant of an internal combustion engine and running an auxiliary cylinder, coupled to the internal combustion engine crankshaft, as a steam engine. U.S. Pat. No. 3,877,229 discloses operating an internal combustion engine in a fuel-rich mode, afterburning the fuel-rich exhaust gases and utilizing the heat from the exhaust gases to heat and expand air supplied to a hot air engine coupled to the crankshaft of the internal combustion engine. U.S. Pat. No. 4,086,771 contemplates utilizing a gas cooling medium, rather than a liquid, in the coolant jacket of an internal combustion engine, and supplying the heated gas to working cylinders in which the heated gas is expanded prior to returning to the cooling jacket. SUMMARY OF THE INVENTION The present invention provides an arrangement of elements whereby the exhaust gases from an internal combustion engine cylinder are circulated, prior to exhausting to the atmosphere, through the cylinder head heating jacket of a working external combustion cylinder into which atmospheric air has been introduced and compressed. The air in the working cylinder is heated by convection through the walls of the heating jacket, and the expansion of the heated air is converted to useful mechanical energy displacing a piston coupled to a crankshaft driven by the piston of the internal combustion cylinder. The air in the external combustion working cylinder, after expansion, is exhausted upon the return stroke of the piston into the inlet of the internal combustion cylinder. The many objects and advantages of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawing wherein: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic top plan view of a compound engine according to the present invention; FIG. 2 is a partial section along line 2--2 of FIG. 1; FIG. 3 is a partial enlarged section along the line 3--3 of FIG. 1; FIG. 4 is a section from line 4--4 of FIG. 3; and FIGS. 5a through 5d are diagrams useful in explaining the working cycle of the compound engine of the invention during a 702° rotation of the engine crankshaft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, and more particularly to FIGS. 1-2, an example of structure for a compound engine according to the present invention is illustrated as comprising a cylinder block 12 in which are provided four cylinders 14, 16, 18 and 20, in each of which is disposed a reciprocable piston, the four pistons being designated by reference numerals 22, 24, 26 and 28, respectively. The pistons 22-28 are connected to a common crankshaft 30, in the usual conventional manner by way of connecting rods 32, the crankshaft 30 being supported at the bottom of the cylinder block 12 through the usual main bearing 34, and having appropriate crank pins 36 each accepting the big end bearing of each connecting rod 32. The crank pins 36 corresponding respectively to the cylinder 14-piston 22 assembly and to the cylinder 18-piston 26 are also aligned but disposed 180° away from the two other crank pins 36. A crankcase cover 38 is fastened to the bottom of the cylinder block 12, and normally contains a provision of lubricating oil and the lubricating oil circulation pump and conduits, not shown, in a manner well known in the art. A cylinder head block 40 is bolted on the top of the cylinder block 12 such as to close the open end of the cylinders 14-20 above the pistons 22-28. In the structure illustrated, the extreme cylinders 14 and 20 are the internal combustion working cylinders of the compound engine of the invention, while the intermediary cylinders 16 and 18 are the external combustion working cylinders. The internal combustion working cylinders 14 and 20 are working preferably according to a diesel-cycle, although it will be readily appreciated that they could be of the Otto-cycle type, or spark ignition internal combustion engine type. Each of the working cylinders 14-20, internal combustion type as well as external combustion type, are four-cycle, i.e. a complete working cycle, consisting of intake, compression, expansion and exhaust, is accomplished during a 720° rotation, or two revolutions, of the crankshaft 30. However, it will be appreciated that the principles of the invention are also applicable to two-cycle internal and external combustion compound engines, in which the working cycle is accomplished during a 360° rotation, or single revolution, of the crankshaft. A camshaft 42 is longitudinally disposed through the cylinder block 12, substantially parallel to the longitudinal axis of the crankshaft 30, and is connected to the crankshaft by a gear or sprocket wheels and chain drive, not shown, in the usual manner such as to be driven in rotation from the crankshaft at half the speed of rotation of the crankshaft 30. The camshaft 42 is provided with a plurality of cams for operating in timed relationship appropriate inlet and exhaust valves associated with each of the cylinders 14-20. The end cylinder 14 is provided with a pair of overhead exhaust valves 44, interconnected by a cross member 48 and operated in unison through a common rocker arm 52 by a pushrod 56. The end cylinder 20 is similarly provided with a pair of exhaust valves 46 interconnected by a cross member 50 and operated by a rocker arm 54 and pushrod 58 assembly. The internal combustion cylinders 14 and 20 are also provided each with a pair of side inlet valves 60 and 62, respectively, the valves in each pair being operated in unison from the camshaft 42. The external combustion cylinders 16 and 18 have each a side inlet valve 64 and 66, respectively, and a side exhaust valve 68 and 70, respectively. As best shown at FIG. 2, and in more details and at a larger scale at FIGS. 3-4 with respect to the external combustion cylinder 18, each of the external combustion cylinders 16 and 18 is placed in communication at its top with an annular heating chamber 72 into which the gaseous contents of the corresponding cylinder is displaced when the corresponding piston 24 or 26 is at its top dead center, with the inlet valves 64 and 66 and the outlet valves 68 and 70 closed, consequently at the end of the compression stroke of either the piston 24 or the piston 26. Each annular chamber 72 has a cylindrical outer wall 83 and a cylindrical inner wall 84, spaced apart, and is provided with substantially diametrically opposed radial passageways 74 and 76 to allow the exhaust gases from the internal combustion cylinders 14 and 20, admitted to an internal exhaust manifold 78 during opening of the exhaust valves 44 and 46, to flow across the heating hollow annular members 72. An inverted dome baffle 80 is disposed substantially coaxially within the cylindrical space defined by the annular heating chamber, spaced apart therefrom as to form a relatively narrow space 82 through which the exhaust gases are caused to circulate such as to be in contact with the inner wall 84 of the annular heating chamber 72. The inverted dome baffle 80 is provided with a disk or annular base 86 bolted over a corresponding opening 88 formed in the cylinder head 40. The bottom face of each inverted dome baffle 80 forms a space 90 directly above the cylinder 16 or 18, through which also circulate the exhaust gases, the inner wall 84 of the annular heating chamber 72 forming an integral parting wall 92 directly above the cylinder 16 or 18. A downwardly directed ridge 94 is peripherally disposed on the outer surface of the inverted dome baffle 80, such as to enhance flow of the hot exhaust gases passing from the passageway 74 to the passageway 76 downwardly in the bottom space 90 such as to cause direct heating of the gas remaining in the cylinder 16 or 18 above the top surface of the respective pistons 24 and 26. Therefore, when, for example, the exhaust valves 44 of the internal combustion cylinder 14 open at the end of the working cycle of the cylinder 14, the exhaust gases flowing through the exhaust manifold 78 are caused to heat the gas contained between the walls 83 and 84 of the hollow annular heating chamber 72 on the top of the external combustion cylinder 16, thus heating the gas in the annular chamber 72 and the remaining gas in the cylinder 16 above the top surface of the piston 24. The gas within the cylinder 16 above the top of the piston 24 is thus caused to expand, in turn displacing the piston 24 downwardly and supplying energy to the crankshaft 30 through the connecting rod 32. A spring return gate valve 94, disposed in the exhaust manifold 78 proximate the exhaust valve 44 of the internal combustion cylinder 14, is arranged to open during exhaust of the exhaust gases from the cylinder 14, but is caused by its return spring (not shown) to close and oppose reverse flow at all other times. Similarly, a gate valve 96 is disposed in the exhaust manifold 78 of the working internal combustion cylinder 20. After circulating around the annular heating chamber 72 and below the inverted dome baffle 80 corresponding to the external combustion cylinder 16, the exhaust gases, which by now have been substantially cooled as a result of supplying heat to the gas in the cylinder 16, are caused to flow through a channel 98 and around and across the annular heating chamber 72 of the external combustion cylinder 18, thus supplying a small amount of heat to the walls 83 and 84 of the heating chamber 72 of the cylinder 18 and to the cylinder end wall 92. The small amount of heat thus supplied to the cylinder 18 is readily dissipated as the cylinder 18 is at this time in the course of its intake stroke, as will be explained hereinafter in more details. As the gate valve 96 is closed, the cooled exhaust gases are directed into a final exhaust passageway 100, FIGS. 3 and 4, the operation of a final exhaust valve 102 by the corresponding cam of the camshaft 42 being so timed that the exhaust valve 102 is open and let the exhaust gases escape through an exhaust manifold 104 to an appropriate muffler or pollution scrubber, not shown. FIG. 1 arbitrarily illustrates the respective position of the diverse pistons 22-28 that correspond to the beginning of the cycle illustrated at FIG. 5a as being 0° of crankshaft rotation. The exhaust valves 44 of the internal combustion cylinder 14 remain open during the exhaust stroke of the piston 22 from substantially 0° of rotation of the crankshaft to its 180° position, or for half a revolution. During the exhaust cycle of the internal combustion cylinder 14, the external combustion cylinder 16 is timed to operate during its expansion cycle, as the gas charge inside of the cylinder 16 above the top of the piston 24 is heated and thus caused to expand as a result of the hot exhaust gases from the cylinder 14 supplying heat to the annular heating chamber 72 of the external combustion cylinder 16. The external combustion cylinder 18 is timed to operate at its intake cycle, FIG. 5a, the inlet valve 66 thereof being open such as to let atmospheric air from the intake manifold 106, FIG. 1 flow into the cylinder 18 above the top of the piston 26, while the piston 26 is passively displaced downwardly as a result of the rotation of the crankshaft 30. As schematically illustrated at FIG. 1, an injector 108 is arranged to inject into the atmospheric air charge taken in by the cylinder 18 atomized alcohol or water, or a mixture of both, for the double purpose of further cooling the atmospheric air introduced into the cylinder 18, and to provide additional expansion and energy as a result of turning the alcohol and/or water into vapors when heat is supplied to the charge in the external combustion cylinder 18. Similarly, the external combustion cylinder 16 is provided with an injector 110 for the same purpose, and it will be appreciated that a single injector may be provided for injecting alcohol, water, a mixture of both, or any other fluid, directly into the intake manifold 106. At 0° of the rotation of the crankshaft, the internal combustion working cylinder 20 is at the beginning of its compression cycle, FIG. 5a, all of its valves, inlet valves 62 as well as outlet valve 46 being closed, the end of the compression cycle in the cylinder 20 occurring at the 180° position of the crankshaft. At FIG. 5a, the arrow 112 symbolically indicates that hot exhaust gases from the internal combustion engine cylinder 14 flow to the heat exchanger formed by the annular heating chamber 72 of the external combustion cylinder 16, thus causing expansion of the charge in the cylinder 16 and applying torque to the crankshaft 30, during the exhaust portion of the cycle of the cylinder 14. As shown schematically at FIG. 1, the external combustion cylinders 16 and 18 exhaust into a common transfer manifold 113 which serves as the intake manifold for the internal combustion cylinders 14 and 20. During the subsequent 180° rotation of the crankshaft 30 from its 180° position to its 360° position, FIG. 5b, the internal combustion cylinder 14 is in the course of its intake cycle, during which its inlet valves 60 are open and its exhaust valves 46 are closed, the piston 22 reciprocating from its top dead center to its bottom dead center. During the intake cycle of the internal combustion cylinder 14, the external combustion cylinder 16 operates in its exhaust cycle, its piston 24 reciprocating from bottom dead center to top dead center and the exhaust valve 68 being open. The gas expelled from the external combustion cylinder 16 during the upstroke of its piston 24 is thus transferred to the cylinder 14 during the downstroke of its piston 22 through the transfer manifold 113. The arrow 114, FIG. 5b, symbolically represents the fluid transfer from the external combustion cylinder 16 to the internal combustion cylinder 14. Simultaneously, during the rotation of the crankshaft from its 180° position to its 360° position, the external combustion cylinder 18 is operating through its compression cycle, while the internal combustion cylinder 20 is operating through its expansion cycle, firing of the charge in the cylinder 20 having occurred substantially at the 180° position of the crankshaft, or, to be more precise, a few degrees prior thereto when fuel was injected into the compressed air above the piston 28 shortly prior to the piston 28 reaching its top dead center. At the 360° position of the crankshaft, the charge in the internal cylinder combustion 20 is fully expanded, thus having applied energy to the piston 28 during its downstroke displacement from its top dead center to its bottom dead center and driving the crankshaft 30 through the corresponding connecting rod 32. Approximately when the crankshaft occupies its 360° position, FIG. 5c, the exhaust valves 46 of the internal combustion cylinder 20 open and, during the subsequent rotation of the crankshaft from its 360° position to its 540° position, upstroke of the piston 28 pushes the hot exhaust gases through the internal exhaust manifold 78 associated with the cylinder 20, the gate valve 96 being caused to open by the flow of exhaust gases while the gate valve 94 is caused to close. The exhaust gases release the majority of their heat to the pre-compressed air in the external combustion cylinder 18, thus causing expansion of the air, and of the alcohol or water vapors mixed therewith, thus forcibly displacing the piston 26 from its top dead center to its bottom dead center and applying motive power to the crankshaft. During that portion of the cycle, the external combustion cylinder 16 is taking a fresh charge through its open intake valve 64 and the internal combustion cylinder 14 is operating during its compression stroke or cycle. The arrow 116, FIG. 5c, arbitrarily indicates the flow of exhaust gases from the internal combustion cylinder 20. When the crankshaft occupies its 540° position, FIG. 5d, or more exactly a few degrees prior to the crankshaft occupying that position, fuel is introduced into the combustion chamber of the internal combustion cylinder 14, while the piston 22 is at, or proximate to, its top dead center, after the charge of atmospheric air in the compression chamber above the top of the piston has been compressed to its smallest volume. During rotation of the crankshaft from its 540° position to its 720° position, FIG. 5b, the ignited fuel-air mixture is expanding, and energy is transferred from the piston 22, during its downward stroke from top dead center to bottom dead center, through the connecting rod 32 and the crank pin 36 to the crankshaft 30. Simultaneously, the external combustion cylinder 16 is operating through its compression cycle, while the external combustion cylinder 18 is exhausting into the combustion chamber of the internal combustion cylinder 20 operating through its intake cycle. The arrow 118 arbitrarily represents such transfer of the charge from the external combustion cylinder 18 to the internal combustion cylinder 20. The four operating cycles of each cylinder are subsequently repeated through the next 720° rotation of the crankshaft. The crankshaft 30 is therefore subjected to four working cycles for each 720° rotation, or two revolutions, each working cycle extending substantially over each 180° rotation of the crankshaft during a complete cycle. It will be appreciated that the internal combustion cylinders 14 and 20 may operate as conventional or Otto-cycle spark ignition internal combustion cylinders, an appropriate fuel, such as gasoline for example, being introduced by conventional carburetor means into the charge transferred from an external combustion cylinder to a corresponding internal combustion cylinder during the simultaneous exhaust cycle of the external combustion engine cylinder and intake cycle of the corresponding internal combustion cylinder, FIGS. 5b and 5d. Starting of the compound engine of the invention is facilitated by a decompression valve 120, FIG. 4, mounted on a cover plate 122 over the external combustion cylinder intake and exhaust valves such as to enable direct atmospheric air intake into the diesel-cycle internal combustion cylinders 14 or 20, if so desired, to enable cold start of the engine. During normal functioning of the engine, the presence of vapors of alcohol or water, or both, in the air charge taken by the internal combustion cylinders greatly improves the combustion characteristics of the air-fuel mixture and the flame propagation characteristics, and greatly reduces pre-ignition and detonation. It is desirable to have the exhaust gases from the internal combustion cylinders to be as high a temperature as feasible, taking into consideration the metallurgical characteristics of the material used for making the exhaust valves and exhaust valve seats and the exhaust passageways and manifolds. Preferably, the surface of the inverted dome baffle 80 in contact with the exhaust gases is coated with a thin layer of ceramic material, as shown at 124 at FIG. 3. The walls of the exhaust manifold 98 may also be protected with a thin layer of ceramic material which, in addition to being substantially thermo-shock proof, acts as a heat insulation reducing substantially transfer of the heat to the subjacent metal, cast iron or steel, used for making the manifold and the dome-shaped baffle 80. Considerable heat energy is present in the exhaust gases whose temperature is generally in the range of 350° C. to 900° C., or even more when such exhaust gases are obtained from a leaned-out internal combustion cylinder. Cooling exhaust gases from such a high temperature to 200°-250° C. through transfer of their heat to the gas contained on the top of the pistons 24 and 26 in the external combustion cylinders 16 and 18, before allowing the exhaust gases to escape to the atmosphere and transforming that heat energy into motive power energy, result in an appreciable increase of the over-all efficiency of any internal combustion engine.

A compound engine having at least one internal combustion cylinder operating in a conventional manner, and an air or external combustion cylinder associated therewith. The external combustion cylinder operates according to the same cycle as the internal combustion cylinder, namely through consecutive intake, compression, expansion and exhaust strokes of the piston associated therewith. The charge taken by the external combustion engine is not fired and is caused to expand by transferring the heat of the exhaust gases from the internal combustion cylinder to the charge in the external combustion cylinder, at the end of the compression cycle thereof, so as to cause the gaseous fluid charge therein to expand to apply motive power to a driven output common to both the internal combustion cylinder and the external combustion cylinder.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to automatic washing machines and more particularly to drive mechanisms for automatic washing machines. 2. Description of the Prior Art An automatic washer spin delay mechanism is disclosed in U.S. Pat. No. 4,218,899 assigned to Whirlpool Corporation, the assignee of this application, in which a delay mechanism provides a delay in the spin cycle of an automatic washer which is operated by means of a pawl pivotable about a stud rotating on an eccentric, which in turn is engageable with a spin gear only in one direction of rotation, and thereby provides a delay of substantially one revolution of the eccentric upon a change in direction of rotation of the eccentric. The delay mechanism is utilized between an agitate portion of the wash cycle and a spin and pump-out portion of the wash cycle to allow for disengagement of rack and pinion means utilized to translate rotational movement of the motor to oscillatory movement of the agitator during the wash portion of the cycle. The oscillatory means must be disengaged so that the agitator is free to rotate with the basket at high speed during a spin portion of the cycle. During this period of time, the washing machine is filled with wash liquid when the basket and agitator begin to rotate in the spin mode. In the washing process it has been found advantageous to pump wash and rinse liquid from the machine while the transmission is in an idle or neutral position, neither agitating nor spinning. This reduces loading on the machine's transmission and also has some advantages in alleviating redeposition of lint and soil from the wash and rinse water onto the laundered garments. In addition, the wrinkling of garments is reduced when the machine has been drained before spinning. Thus, a means for shifting the transmission to an idle or neutral position while the wash liquid is being pumped from the wash tub, is required to gain the advantages listed above. Several attempts have been made to provide a means to shift the drive mechanism of an automatic washer into neutral including solenoid operated shifter arm mechanism in U.S. Pat. No. 4,283,928, a rotary damping action in U.S. Pat. No. 4,231,237, a water level responsive delay mechanism in U.S. Pat. No. 4,038,841 and a centrifugal force mechanism delaying spin in U.S. Pat. No. 3,197,982. SUMMARY OF THE INVENTION An automatic washer of the present invention utilizes a single motor and drive mechanism to operate a vertical axis agitator and a clothes basket during washing and drying portions of a complete cycle. A rack and pinion means is provided to translate rotational movement of the motor to osillatory movement of the agitator during the wash portion of the cycle. The oscillatory means must be disengaged by means of a jaw clutch so that it is free to rotate with the basket at a high speed during a spin portion of the cycle. The jaw clutch is provided to cause engagement and disengagement of the oscillatory means with the agitator upon a change in direction of rotation of the motor. The disengagement means requires one complete rotation of a drive gear to ensure complete disengagement. In addition, it is found to be desirable to shift the transmission into a neutral or idle position in which the basket and agitator are neither spinning or agitating while the wash or rinse liquid are being pumped out of the washer tub. In accordance with the present invention, the transmission is shifted to an idle position for an amount of time sufficient to allow substantially all of the wash or rinse liquid to be pumped from the wash tub prior to initiation of the spinning mode. Also, means may be provided to ensure that the basket and agitator will remain in the spin mode if power is interrupted during the spin mode operation. More specifically, a spring tang which rotates a drive pawl into a spin position when the main drive gear begins rotating in the spin direction, is prevented from engaging the drive pawl by being captured by a centrifugal latch mechanism. A first hook intercepts the tang which is mounted on the spin gear for rotation therewith, but which also can slip on the spin gear, such that the tang does not contact the drive pawl to pivot it into the spin position but rather allows it to remain in the neutral position. After the liquid has been pumped from the washer tub, there is a pause provided by the automatic timer mechanism which allows the motor and main drive gear to come to rest. At this point the latch mechanism releases the tang which then rotates into contact with the drive pawl, pivoting it into the spin position. When power is resumed, the drive pawl engages an abutment on a spin gear to drive the spin gear and washer basket. If there is a power interruption during the spin cycle, such as occurs whenever the access lid is opened during spin, the coasting of the basket will cause the spin gear tang to move away from the drive pawl. To prevent the tang from being reintercepted by the latch mechanism upon reinstatement of power, there is provided a second hook on the latch mechanism to capture the tang to prevent excessive rotation relative to the latch mechanism. Restarting of the motor in a spin direction will cause the tang to pass the first hook of the latch mechanism and to again abut the drive pawl to pivot it into the spin position. If the motor is restarted in the agitate direction, the latch mechanism will release the tang and the tang will rotate in the opposite direction to contact an opposite side of the drive pawl to positively hold it in the agitate position. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view, partially broken away, of an automatic laundry appliance embodying the present invention. FIG. 2 is an enlarged sectional view of the clutch and spin delay mechanism taken generally along the lines II--II of FIG. 4. FIG. 3 is an enlarged partial sectional view of the second pawl mechanism taken generally along the lines III--III of FIG. 4. FIG. 4 is an enlarged sectional view of the clutch and spin delay mechanism of the laundry appliance of FIG. 1 in the agitate position. FIG. 5 is an enlarged partial sectional view of the pawl mechanism of FIG. 4 in the latched or pump-out position. FIG. 6 is a sectional view similar to that shown in FIG. 5 with the mechanism in the spin position. FIG. 7 is a sectional view similar to that shown in FIG. 5 with the mechanism in the spin interrupted position. DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic washing machine is generally illustrated in FIG. 1 at 10 and comprises a cabinet 12 with a top 14 and an openable lid 16 thereon. The lid 16 opens to provide access to the interior of a perforate wash basket 18 mounted concentrically within an imperforate wash tub 20. A vertically mounted agitator 22 is carried within the wash basket 18 and is driven by an electric motor 24 operating through a transmission 26. The motor 24 also drives a water pump 25 for discharging wash liquid from the wash tub 20 to a drain (not shown). The top 14 of the washing machine is provided with a console 32 which carries the user operated controls including a timer actuated control 34 used in selecting and operating the machine through a series of washing, rinsing and drying steps. Referring to FIGS. 2 and 4, a worm gear 36 is carried on one end of a drive shaft (not shown), the other end of which is connected to the motor 24 (FIG. 1). The worm gear 36 is disposed within a transmission housing 37 including a gear case cover 38 and engages teeth 39 disposed circumferentially on a lower surface of a main drive gear 40. The drive gear 40 is rotatably mounted on a jack shaft 42 and rests on a bearing washer 44. An upper portion of the drive gear 40 has an eccentric 46 integrally formed thereon. One end of a rack 48 has an opening for receiving the eccentric and operates in slidable movement therewith. A bearing plate 50 is positioned above the rack 48 on the eccentric 46 and held in place by a stud 52 which is received in a receptacle 54 in the eccentric 46. Mounted above the bearing plate 50 and concentric with the drive gear 40 is a spin gear 56 having teeth 58 which engage teeth 60 on a spin pinion 62 rotatable about agitator shaft 64. All elements mounted on the jack shaft 42 are maintained in adjacent relation by a washer 66 which is held in place by a snap ring 68. An opposite end of the rack 48 has a loop 70 which surrounds the agitator shaft 64. A row of teeth 72 are formed on one side of the loop 70 and engage teeth 74 formed on a portion of the exterior of an agitate pinion 76 rotatably mounted about the agitator shaft 64. The side of the loop 70 opposite the teeth 72 has a smooth bearing surface 78 movable against a portion of the exterior of the pinion 76 having no teeth thereon, thereby ensuring complete engagement of the teeth 74 on the agitate pinion and the teeth 72 on the rack. As the eccentric 46 is rotated by the main gear 40, a reciprocal motion in a plane normal to the agitator shaft 64 is imparted to the rack 48. This reciprocatory motion is transferred to the agitate pinion 76 by means of engagement of the teeth 72 and 74, causing the oscillatory motion in the agitate pinion. This oscillatory motion is then transferred to the agitator shaft 64 through a jaw clutch means as described and disclosed in U.S. Pat. No. 4,218,899 which is incorporated herein by reference. As seen in FIGS. 2 and 4, there is a drive pawl 80 pivotally mounted on the stud 52 for corotation with the drive gear 40 about the jack shaft 42. The pawl 80 has a first end 82 having an angled surface 84 which is capable of drivingly engaging an abutment 86 on an outer wall 93 of an annular channel 95 formed in the lower side of the spin gear 56 when the drive pawl 80 is pivoted into a spin position such as shown in FIG. 6. A second end 88 of the drive pawl 80 is provided in a size and shape to prevent pivotal movement of the drive pawl when the drive gear 40 is rotated at high speeds. The second end 88 is shaped to provide a clearance with the abutment 86 when the drive pawl 80 and drive gear 40 rotate in the clockwise agitate direction relative to the stationary spin gear 56. A control spring 90 having a radially outwardly extending tang 92 is fitted around an inner wall 94 of an annular channel 95. The control spring 90 is slidingly mounted on the inner wall 94 such that a rotating force supplied to the control spring 90 via the tang 92 will not cause rotation of the spin gear 56. As the drive gear 40 rotates in the clockwise agitate direction, an inner surface 96 on the inwardly extending portion of the drive pawl 80 contacts a first edge 98 of the tang 92 which causes the drive pawl 80 to pivot about stud 52 in a counterclockwise direction. This pivoting action moves the second end 82 of the drive pawl radially inwardly so that it will clear the abutment 86 on the spin gear 56. As the drive pawl 80 mounted on the drive gear 40 continues to rotate in a clockwise direction around the jack shaft 42, the control spring 90 and tang 92 are caused to slide on the surface 94 of the spin gear without causing the spin gear itself to rotate. Upon reversal of the drive motor 24, the transmission mechanism would normally shift into a spin position in accordance with the teachings of U.S. Pat. No. 4,218,899. However, it has been found desirable to shift the transmission into a neutral or pause position to allow the water pump 25 to substantially drain tub 20 before the basket 18 is rotated to centrifuge the laundry. There is provided a latch mechanism designated generally at 100 in FIGS. 2 through 7 which is comprised of a latch pawl 102 pivotally mounted by means of a pivot pin 104 (FIG. 3) to the bearing plate 50 which is secured for rotation to the eccentric 46 of the drive gear 40. The latch pawl 102 is pivotally mounted in an off-center manner such that a first end 106 extends a greater distance from the pivot pin 104 and contains more mass than a second end 108. The second end 108 has a first hook portion 110 associated therewith which comprises a radially inwardly extending nose portion 112 and an abutment surface 114. A spring mounting member 120 mounts a return spring 116 on the bearing plate 50. The spring 116 engages an outer wall 118 on the first end 106 side of the pivot pin 104. This return spring 116 biases the latch pawl 102 in a counterclockwise direction about pivot pin 104. As the latch pawl 102 rotates with the rotating drive gear 40, centrifugal force acting on the relatively massive and extending first end 106 of the latch pawl 102 causes the latch pawl to pivot in a clockwise manner about pivot pin 104 overcoming the bias of the return spring 116. The spring mounting means 120 forms a stop member radially outwardly from the latch pawl 102 to provide a limit on the pivotal movement of the latch pawl 102. This ensures that the outer surface 118 of the latch pawl 102 will not contact the abutment 86 on the spin gear 56 as the drive gear 40 rotates relative to the spin gear. As seen in FIG. 4, when the drive gear 40 is rotating in the clockwise agitate direction, the tang 92 of the control spring 90 is contacted at edge 98 by the inner surface 96 of the drive pawl 80 which urges the drive pawl 80 to rotate counterclockwise about stud 52 into a neutral position not driving the spin gear 56. When the motor is shifted to the opposite spin and pump-out direction, the drive gear 40 rotates in a counterclockwise direction thereby resulting in the drive pawl 80 moving away from the tang 92 of the control spring 90. This occurs because the control spring 90 is mounted on the spin gear 56 which remains stationary. As the drive gear 40 begins moving in the counterclockwise spin direction, centrifugal force acts on the first end 106 of the latch pawl 102 urging it outward and thereby causing the first hook portion 110 to be pivoted inwardly. As the drive gear 40 continues its rotation, the abutment surface 114 of the first hook 110 comes into contact with a second edge 122 of the tang 92 as seen in FIG. 5. The hook 110 positively intercepts the tang 92 and thereby prevents it from contacting the second end 82 of the drive pawl 80 which could cause it to move into the spin position. In this manner, the drive pawl 80 remains in the neutral position as is shown in FIG. 5 and the control spring 90 and tang 92 are caused to slide on the surface 94 of the spin gear 56 without rotating the spin gear. Thus, the pump is able to pump wash liquid from the wash tub without the basket 18 spinning. The timer mechanism 34 is provided with pause at the end of the pump-out portion of the wash cycle to allow the motor 24 and main drive gear 40 to come to rest. Due to the force of the return spring 116 and since the frictional torque on the spin gear spring 90 is basically constant with velocity, a trip point occurs during deceleration of the main drive gear 40 which forces the latch pawl 102 to pivot in a counterclockwise direction about pin 104 thereby disengaging the hook portion 110 from the end 122 of the tang 92. This results in the drive pawl 80 rotating into contact with end 122 of the tang 92 causing the first end 82 of the drive pawl 80 to be rotated radially outwardly. Upon restarting the motor in the spin direction, the first end 82 of the drive pawl 80 will be rotated into contact with the abutment 86 such that the abutment surface 84 of the drive pawl 80 drivingly engages the abutment 86 and drives the spin gear 56 and thus the basket 18 in a rotary manner (FIG. 6). In this mode, the drive gear 40 and spin gear 56 are corotating about the jack shaft 42 by means of the connection of the drive pawl 80. If there is a power interruption to the motor 24 during the spinning portion of wash cycle, as would occur if lid 16 were opened, it has been found that the basket 18 and spin gear 56 will continue to coast after the drive gear 40 has stopped. This results in the control spring 90 and tang 92 rotating in a counterclockwise direction away from the drive pawl 80. As the basket, and thus spin gear 56 make one revolution, the abutment 86 would push against the first end 82 of the drive pawl 80 causing it to pivot in a counterclockwise direction and thus into the neutral position. To prevent the transmission from operating in the neutral position after power to the motor has been reinstated during the spin portion of the cycle, a second hook means 124 is provided on the latch pawl 102 on the first end 106 side of the pivot pin 104 but sufficiently close to the first hook 110 such that the second end 122 of the tang 92 will be closely adjacent the first hook 110. With the return spring 116 urging the latch pawl 102 in a counterclockwise pivotal direction about pivot pin 104, the tang 92 is positively captured by the second hook 124 as the second hook 124 contacts the first edge 98 of the tang as seen in FIG. 7. If power to the motor is restarted in the spin direction, the rounded portion of the second edge 122 of the tang 92 will contact the nose portion 112 of the first hook 110 thereby permitting the tang 92 to pass the first hook portion 110 before sufficient centrifugal force operates on the latch pawl 102 to pivot the latch pawl 102 in a clockwise direction to an intercept position. Thus, the drive pawl 80 will be rotated into contact with the second end 122 of the tang 92 and will be pivoted again into the spin position as shown in FIG. 6. In this manner, the transmission will be prevented from remaining in the neutral position after interruption during the spin portion of the cycle. If the motor is restarted in the agitate direction after power interruption during the spin portion of the cycle, the drive gear 40 will begin rotating in the clockwise direction and as its speed builds, centrifugal force will act on the latch pawl 102 causing the first end 106 to pivot radially outwardly thereby releasing the second hook 124 from the first edge 98 of the tang 92. Then as the drive gear 40 continues to rotate, the interior surface 96 of the drive pawl 80 will contact the first edge 98 of the tang 92 at the second end 88 of the drive pawl 80 to positively pivot the drive pawl 80 into the agitate and neutral position. Thus, there will be sufficient clearance between the drive pawl 80 and the abutment 86 on the spin gear 56 to prevent rotation of the spin gear. In this manner, the transmission will operate in the agitate direction as is shown in FIG. 4. In this manner, the transmission can be operated in a neutral position to provide a pump-out portion of a wash cycle and the transmission is prevented from returning to the neutral position after a power interruption during a spin portion of the wash cycle by the utilization of only a drive pawl and a latch pawl, additional parts and mechanisms not being necessary. As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.

A means for operating a washing machine transmission in a neutral state is provided which includes a reversible drive gear for driving the transmission in a first agitate direction and an opposite spin direction. A drive pawl is pivotally mounted on the drive gear. Pawl pivoting means, being a circular control spring with an outwardly extending tang is selectively rotatable against either side of the pivoted pawl and a latching pawl selectively captures the tang when the drive gear is rotating in the spin direction to operate the transmission in a neutral state until the rotation of the spin gear is interrupted. Means are provided on the latch pawl to prevent relatching of the control spring if the rotation of the drive gear is subsequently interrupted.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60/733,982, filed Nov. 3, 2005, and is a continuation-in-part of U.S. patent application Ser. No. 10/786,023, filed Feb. 26, 2004. The entire contents of those applications are incorporated herein by reference. FIELD OF INVENTION [0002] This invention relates to a computer system and method of authenticating identities for making transactions, such as making payment deposits, or for obtaining access to restricted information, without the need for security or encryption devices. BACKGROUND [0003] In today's fast paced computer dependent world, people make purchases, payments, deposits, and other financial transactions without the exchange of traditional money, checks, or even the simple act of handing a teller a credit or debit card. Many transactions made by individuals today are done over the telephone or Internet. To accomplish this, people must submit unique identifiers in order for their preferred payment instruments to be accepted and activated. Such identifiers include the person's name, address, credit card number, CVS number, and frequently, a PIN or “shared secret” such as a mother's maiden name or family pet's name. Identifiers can quickly become dispersed among several credit card company databases, healthcare databases, mortgage company databases, and on-line merchant databases. These identifiers may be transferred over a wireless network or a portion of the Internet, which may make them vulnerable to be copied in transit. These identifiers may be captured by spy-ware sending keystrokes on a computer to a thief lurking in any corner of the world. [0004] It is not unusual in the course of a consumer's relationship with a bank, a healthcare provider, an insurance company, a merchant or a credit card company for him to need to access his account records. It might be to dispute a payment, to prove a payment was made, to verify an order, or to simply check an account balance. To gain access to his records a person must provide his unique identifier information to validate his identity. In certain healthcare circumstances, only a person's duly authorized physician may access a healthcare provider's databases containing his medical records. [0005] With so many in-person enrollments and on-line registrations for various utility companies, on-line merchants, and banking and healthcare providers, it is a common practice for people to use the same passwords, PINs, and “shared secrets,” so they can remember what to provide should they someday need access to a certain database. An unintended byproduct of the dispersal of a person's unique identifiers among so many locations is the emergence of identity theft crime. Once a weak link in the chain of trust breaks, a fraudster can appropriate an identity and direct an unauthorized flow of funds. [0006] Depending on the payment instruments used, detection of this illegal activity might not occur for several days, weeks, or even months. There is not a priori notification to the true owner of such unique identifiers that access to information is being sought because it is assumed that the person gaining access to such information IS that person. Economic harm is not the only kind of harm wrought by fraudsters. For instance, illegal access to health records can prevent a job hire, cancel an insurance policy, or restrict freedom of movement. [0007] Therefore, there remains a need in the art for an easy and convenient system and method for validating another person's identity without the need for security or encryption devices. There also is a need in the art for notifying a person when authentication of their identity is made, by whom, and for what purpose. There is a need to deeply validate identity involving access to restricted records such as digital signatures of the registrar-institution that deposited the person's unique identifiers. There is the need for banks and healthcare institutions to obtain proof that information's accuracy is protected by a liability contract. There is a need for individuals to be able to know about and approve transactions that can involve private aspects of their identity. [0008] User concerns that need to be addressed are: How can I be SAFELY identified on Internet? Who's willing to vouch for me to third parties? Shouldn't I be informed when my information is sought, by whom and for what purpose? How do I know what's known about me, by what entities, and how is their knowledge cloaked or hidden? [0013] Privacy Rights Management is a new industry. Numerous registries of identities exist today and identifiers can be correlated among them. There is a need for information to flow to consumers when such correlations happen so they can approve the use of their private identifiers. [0014] This need in the art extends but is not limited to specific communities of interest wherein access to information, or approval of a transaction involving transfer of a financial or information asset, is an essential element. This is a key part of interactions between various users, consumers, businesses, agencies, regulators, and/or other interested parties. These interactions may include validation and authentication for instances such as: approving access for review purposes to financial, health care, subscription, personal, or other information; determining identity-related status for shipping and receiving of physical items; determining suitable status for the transfer of tokens and access rights for digital products; for eligibility to view and print tickets, reservations, airline boarding passes, or other digital documents; and for determining authenticity of source when material for publication or edits to web-knowledge repositories such as Wikipedia is submitted by persons whose identities are not hidden or partially obscured, but true. [0020] Finally, there is a need in the art to mediate between public and private aspects of potentially shared information. In particular, there is a need for identifiers that enable access and transactions while preserving privacy and protecting information. This includes identifiers that are suitable for public exposure, for direct use (e.g., the “one-way” public payment addresses known as Linked Credit Account or LCA and others of its class of payment addresses having similar one-way characteristics), or for indirect use (e.g., simply as an identifier solely used to initiate authentication processing). It also includes healthcare identifiers used to access personal healthcare information (PHI) for individuals, as well as identifiers and related transactions relevant to other communities of interest. SUMMARY [0021] It is an objective of the present invention to provide individuals and institutions with an easy and convenient way to authenticate identities for transactions to receive payment and credit or for actions to obtain access to restricted information. [0022] Another objective of the present invention is to establish a system that accepts authenticated identities without the need for security or encryption devices. [0023] It is a further objective of the present invention to utilize the particular types of identity in conjunction with various accounts for financial transactions or for accessing restricted information. [0024] It is a further objective of the present invention to utilize the particular types of identity in conjunction with various systems or networks for financial transactions or for accessing restricted information. [0025] It is a further objective of the present invention to utilize the particular types of identity in conjunction with financial systems and networks worldwide. [0026] These and other objectives of the present invention will be apparent in the following description. [0027] The identities and transactions embodied in this invention are applicable to banks, customer payment addresses, and making and receiving payments; to healthcare providers, healthcare identifiers of individuals, and access to healthcare information records; and for other communities of interest, their respective identity/authentication providers, subscriber identifiers, and transactions relevant to their respective community. This invention preferably includes the use of ENUM technology to associate phone numbers with respective identifiers (such as certain payment addresses) in public systems (such as the DNS) or in private systems. [0028] In one aspect, the invention comprises an Identity Authentication Bureau that functions as a registry that lists identifiers in a directory that has both open and restricted access. This registry is referred to herein for convenience as “Greenlist.” It is designed for third parties to use to verify identities for making financial transactions or for obtaining access to restricted information. Third parties function as transaction enablers. These entities bear certain risks of negative consequences when one party is not who or what it claims to be. One unique characteristic of the Greenlist registry (or directory of identifiers) is that it can be completely trusted by risk-bearers. This trust can be established with certainty. Liability for risk can be transferred to the registrars of the information contained within the registry. This liability transferal substantially reduces the cost of bearing risks. Third parties responsible for certifying that someone or some entity claiming to be an authorized party is not an impostor can now offer new levels of service at a substantially lower cost for a variety of transactions. [0029] Trust in the Greenlist can be “constructed” with Digital Signatures as specified by liability and fraud-protection contracts. Various entities can define and create their communities of interest by authorizing their banks to function as registrars and supply record access information in an extension of ENUM, the Internet standard method for using phone numbers in the Internet's Domain Name System. Telephone Number Mapping (ENUM or Enum, from TElephone NUmber Mapping) is a suite of protocols to unify the telephone numbering system E.164 with the Internet addressing system DNS by using an indirect lookup method, to obtain NAPTR records. The records are stored at a DNS database. [0030] In the VoIP context (making phone calls via the Internet), ENUM has been used as follows: if a calling party on the PSTN network or the Internet identifies a called party ENUM number by the called party's E.164 number, that E.164 number will be translated at the ENUM gateway into the corresponding URI. This E.164 number will be used to look up and fetch a NAPTR record obtaining the URI that indicates the called party's instructions for how the call should be forwarded or terminated. The registrant (the called party) has specified in the ‘NAPTR record’, “Naming Authority Pointer Resource Records” as defined in RFC2915 (superseded by RFC 3403), and the URI it contains, such as e-mail addresses, a fax number, a personal website, a VoIP number, mobile telephone numbers, voice mail systems, IP-telephony addresses, web pages, GPS coordinates, call diversions or instant messaging. [0031] ENUM technology is being used in a range of public and private environments. Records stored in the DNS are accessible via public queries. Records stored in private databases using DNS and ENUM technologies have controlled access. VoIP is an example of an ENUM-enabled application, wherein an application uses ENUM to map a phone number to a URI for a service that the application can then use to perform its services. [0032] Use of ENUM as a directory service infrastructure makes ENUM more valuable as a public resource. The Identity Authentication Bureau, Greenlist, can be accessed directly for public identity information such as a public payment address, as described in U.S. patent application Ser. No. 10/786,023, filed Feb. 26, 2004. The present invention comprises an improvement on the “publicly available” aspects discussed in U.S. patent application Ser. No. 10/786,023. The Greenlist provides, for each user, a webpage that payors (or others) can access. Different payors, and risk bearing enablers of transactions, via digital certificates or other means of identification, may be allowed to view different information (for example, an insurance provider may be able to access a social security number). Also, the Greenlist operator provides assurance that the payee is who he says he is and his specified payment address is true. [0033] The Greenlist acts as a virtual safe deposit box, where identity information may be deposited and withdrawn without need for data replenishment. Withdrawals can be made by simple database lookup conventions. Information that needs to be certified as true and vouched for by registrar entities willing to transfer liability for risk bearers, may or may not be derived from the external processes described, for example, in U.S. Pat. App. Pub. No. 2005/0259658, filed Aug. 6, 2005. All information may be trusted as true because identity information can only be removed or modified by the original depository institution that is liable for its accuracy and currency. [0034] Some identity information may be withdrawn only by members of a community of interest. When a bank performs a mobile authentication step, owners of that record for the Payor and Payee are notified in the manner of preference as specified during enrollment (e.g., email, fax, voice messaging, or instant messaging). Different communities of interest can use the Greenlist to enable authenticated access or authenticated transactions, e.g., for granting digital rights, for receiving shipments, or for printing documents such as tickets or boarding passes. [0035] In one aspect, the invention comprises a system for authenticating a payor and a payee in an electronic fund transfer, comprising: a bank computer linked via a computer network to a payor's computer and a directory computer, the payor having at least one account at the bank and having been authenticated to the bank computer; wherein the directory computer is operable to maintain a first database of authenticated registrant information comprising authenticated information for the payee identifying at least one linked credit account of the payee and to provide a portion of the first database via the computer network to the bank computer on periodic basis, the portion comprising the authenticated information for the payee; wherein the bank computer is operable to maintain a second database comprising data from the portion of the first database and further comprising ENUM data for registrants in the portion of the first database; and wherein the bank computer is operable to receive ENUM information and payment information from the payor computer identifying the payee, map the information identifying the payee to the linked credit account of the payee using the portion of the first database, and transmit a payment from the payor's at least one account to the payee's linked credit account. [0036] In another aspect, the invention comprises a method of authenticating a payor in a financial transaction, comprising: (a) receiving, via a computer network, information comprising linked credit account information and telephone number information from a payee who has an account at a first bank and who has been authenticated; (b) associating via a computer of the first bank the linked credit account information and telephone number information of the payee with a URN; (c) transmitting information comprising the telephone number information and the associated URN to a database in communication with a computer of a second bank; and (d) electronically receiving funds from a payor account to the linked credit account. [0037] In another aspect, the invention comprises a method of authenticating a payee and a payor in a financial transaction, comprising: (a) receiving via a computer network payee phone number information from a payor who has an account at a bank and who has been authenticated; (b) associating via a computer linked to the computer network the payee phone number information to linked credit account information of the payee using ENUM; (c) transmitting to the payor via the computer network verification that the telephone number has been associated with the linked credit account information of the payee; (d) receiving via the computer network authorization from the payor to transfer funds from the payor account to the linked credit account; and (e) electronically transferring the funds from the payor account to the linked credit account. [0038] In another aspect, the invention comprises a method of providing authentication, comprising: (a) receiving authenticated registrant comprising a registrant telephone number and registrant account information; (b) storing the registrant information in an electronic database accessible by a computer in communication with a computer network; (c) associating the registrant information with ENUM data; (d) transmitting the registrant information to a directory computer; and (e) transmitting the associated information to a directory user. [0039] In various embodiments: (1) the directory user is a bank; (2) the directory user is a health care institution; (3) the registrant account information comprises a linked credit account; and (4) the associated information comprises personal health care information. [0040] In another aspect, the invention comprises a system for authenticating a sender and a receiver in an asset transfer, comprising a bank computer linked via a computer network to a sender's computer and a directory computer, the sender having at least one asset account at the bank and having been authenticated to the bank computer; wherein the directory computer is operable to maintain a first database of authenticated registrant information comprising authenticated information for the receiver identifying at least one linked account of the receiver and to provide a portion of the first database via the computer network to the bank computer on periodic basis, the portion comprising the authenticated information for the receiver; wherein the bank computer is operable to maintain a second database comprising data from the portion of the first database and further comprising ENUM data for registrants in the portion of the first database; and wherein the bank computer is operable to receive ENUM information and payment information from the sender computer identifying the receiver, map the information identifying the receiver to the at least one linked account of the receiver using the portion of the first database, and transmit an asset transfer from the sender's at least one account to the receiver's at least one linked account. [0041] In various embodiments: (1) the bank is a licensee of the directory computer; (2) the linked account is an identifier, encodable as a URN, of the receiver; (3) the payment information comprises information identifying the receiver; (4) the asset transfer actually transfers an asset or transfers ownership thereof from the sender to the receiver; (5) the asset is a payment or financial instrument; (6) the asset is a digital construct; (7) the asset is one or more physical objects; and (8) the asset is information, right or access permission. BRIEF DESCRIPTION OF THE DRAWINGS [0042] FIG. 1 is a diagram showing preferred components of a system embodiment of the invention. [0043] FIG. 2 depicts a preferred Master Directory enrollment process. [0044] FIG. 3 depicts a preferred Master Directory bank setup/maintenance process. [0045] FIG. 4 depicts a preferred Master Directory enrollment/maintenance process. [0046] FIG. 5 depicts a preferred bank subsystem Greenlist update process. [0047] FIG. 6 depicts a preferred Greenlist Internet inquiry process. [0048] FIG. 7 depicts a preferred Master LCA account assignment/validation process. DETAILED DESCRIPTION [0049] FIG. 1 is a diagram showing preferred components of a system embodiment of the invention. Greenlist 100 is a set of directory and processing systems. The Greenlist maintains databases 105 . A bank 110 that enrolls with the Greenlist may offer Greenlist subscriptions to customers. Bank 110 maintains its own databases 115 . [0050] A Greenlist subscriber 120 may opt for ENUM functionality: the Greenlist subscriber is an ENUM registrant, the bank and the Greenlist handle ENUM registration, and the subscriber's phone number (as a domain name) is entered in the Internet's Domain Name System, commonly referred to as the DNS 130 . Alternatively, the subscriber's phone number (as a domain name) may be entered in an analogous system, e.g., for private ENUM, possibly with controlled access. [0051] A payment (or other) transaction may be performed by a transaction processing system 140 . The transaction may be initiated by an initiator 150 , such as a payor, a payee, or a third party. The initiator 150 may (or may not) be a Greenlist subscriber choosing to initiate a transaction with another Greenlist subscriber 120 . [0052] The transaction processing system 140 may discover that the transaction will require the involvement of or certain information about a Greenlist subscriber 120 . Instances may include (but are not limited to) the following: a payee may be notified that a payment has been received, thus allowing for purchased goods to be shipped; a payor's preferred notification methods and public payment address may be needed so that the payor can authorize the payor's bank to make a payment from an associated non-public account. [0053] The transaction processing system 140 may satisfy its information and processing requirements related to a Greenlist subscriber 120 by first placing an ENUM query via the DNS 130 using the subscriber's phone number to retrieve a Greenlist identity for the subscriber. The system 140 may then interact with the bank's systems 110 as needed. In one instance, the bank 110 may interact with a subscriber 120 who is a payor in order to receive authorization to make a payment. [0054] Once the transaction processing system 140 has satisfied its information and processing requirements related to a Greenlist subscriber 120 , possibly involving ENUM-enabled applications that may query systems such as the DNS 130 , it can complete the transactions and return status notification to the initiator 150 . [0055] When a subscriber 120 enrolls with a Greenlist Bank 110 , the subscriber may be assigned one or more identifiers related to a transaction processing system 140 associated with a particular community of interest. These identifiers may be public or private. Such an identifier may be encoded as a “name” (more formally, as a Uniform Resource Name). Further, such an identifier may be associated with the subscriber's phone number for retrieval from the DNS 130 or analogous public or private system (more formally, through the use of the NAPTR Resource Record, as described in the Terminology section below). [0056] A particular example is the use of a public payment address, such as a Linked Credit Account (LCA), which may be retrieved by an ENUM query of the DNS using a phone number as the starting point, and leading to a payment transaction facilitated by the Greenlist 100 and the bank 110 . [0057] In one aspect, this invention comprises elements and functions that can be grouped into three conceptual layers. The outer layer, the Transaction/Consumer Layer, is closest to the consumer. The intermediate layer, the Enrollment Layer, makes the consumer a conceptual part of the infrastructure. The innermost layer, the ENUM/Greenlist Layer, is the conceptual infrastructure for the system of the invention. [0058] I. TRANSACTION/CONSUMER LAYER (also Merchant Layer and Small and Medium Business-SMB Layer) [0059] This outer layer, for financial transactions, is comprised in one embodiment of users' banks seeking to discover validated payment addresses so that money can be sent between banks in a more efficient manner than that of the current payments model. This is accomplished by querying the GreenList. [0060] In one embodiment, the user does not need to know that any ENUM-enabled directories are queried because this is accomplished by his bank acting as his proxy. The user only experiences his bank's on-line banking portal, which might have a pull-down tab offering him search options to discover his friend's payment address. All he really knows or cares about is his trust relationship with his personal bank. The very act of presenting a search tool and a result implies that payment address validation has been accomplished to the satisfaction of a bank. This trust relationship is already present between a consumer and his personal bank before the consumer asks his bank to enroll him in the Identity Bureau. [0061] The user can enroll for mobile authentication features through the Greenlist Web Portal. [0062] The features of mobile authentication include the following: [0063] a.) they can be activated for his existing bank account; [0064] b.) they can be activated for his proxy Greenlist bank account while he retains his true bank account at another bank; and [0065] c.) they can specify a separate receive-only payment address in addition to activating powerful mobile authentication features. [0066] When the user's enrollment is complete, he is said to have (or to have been) “enrolled” in the GreenList. He has been “GreenListed.” [0067] II. ENROLLMENT/BANK LAYER (also Bank Clearinghouse Layer and Healthcare Clearinghouse Layer) [0068] This layer is where many linkages occur. It is the enrollment, registration, and provisioning layer for the user. This layer assigns a Greenlist account number for the user who enrolls in the GreenList so that he can then make mobile-authenticated e-payments. This layer also functions as an ENUM Registrar, or works with the user's existing ENUM Registrar on his behalf, for subsequent provisioning of his GreenList enrollment information into his ENUM domain (maintained by his ENUM Tier II Provider, described below). [0069] A bank may take this additional step for its customers (registrants) when it wishes its customers to be able to receive e-payments from other persons who are banked at other banks and who have registered in other Greenlist payment systems. The GreenList bank may digitally sign the “Payload” that it is provisioning into the user's ENUM domain. [0070] In the case when the user does not already have his phone number registered for ENUM, the bank can act on behalf of the user as an ENUM Registrar, or as his agent with an existing ENUM Registrar. This process “registers” the user's phone number into ENUM and sets up the relationships for the user's ENUM domain to be maintained by an ENUM Tier II Provider. Once this is in place, the GreenList bank acting as or via an ENUM Registrar can provision the user's GreenList “Payload” information into the user's ENUM domain as maintained by his ENUM Tier II Provider. [0071] III. ENUM/GreenList LAYER [0072] This is the conceptual layer providing the information infrastructure. This layer contains ENUM domains, maintained by users' ENUM Tier II Providers, and is managed subject to standards certified by the ENUM CC1 LLC. This layer also can be called the GreenList Root Layer since it contains the Greenlist, maintained by the GreenList bank. [0073] Terminology [0074] This section explains how certain terms are used in this description. [0075] ENUM is Electronic NUMbering, an IETF Protocol, described in RFC 3761. [0076] An ENUM Subscriber is the assignee of an E.164 number who has agreed to register that E.164 number for insertion and use as a domain name in the Internet DNS and who subsequently requests population of its ENUM domain with certain DNS resource records containing data associated with that E.164 number. This data consists of Uniform Resource Identifiers (URIs), such as web addresses, and each such URI is contained in its own Naming Authority Pointer DNS (NAPTR) Resource Record. It is these NAPTRs that are populated into the subscriber's ENUM domain, and it is the subscriber's ENUM Tier II Provider that hosts and operates his ENUM domain. The ENUM subscriber has full control over the provision and content of the NAPTR resource records in the ENUM domain for the E.164 number. [0077] An ENUM User is a person or entity who is querying the DNS about an E.164 number, typically using an ENUM-enabled Application Client or an ENUM Client, in order to retrieve DNS resource records associated with the E.164 number. The ENUM User will generally be aware only of the application and not of the use of ENUM by the application. [0078] An ENUM Registrar can do many things, but minimally it must register the user's phone number into the Domain Name Server/Service (DNS). In this document, the ENUM Registrar for an ENUM Subscriber will be viewed as the primary point of contact between the ENUM Subscriber and the DNS, and acting on the ENUM subscriber's behalf, handles and coordinates the processes of registration of the phone number for ENUM, setting up the ENUM domain for the phone number, and populating that domain with the DNS resource records that are associated with that phone number. [0079] An ENUM Registrant is the telephone number assignee, the ENUM Subscriber. [0080] An ENUM Tier II Provider is an entity that operates the ENUM domain for the ENUM Subscriber within the Internet DNS. The ENUM Tier II provider is responsible for maintaining the ENUM Subscriber's DNS resource records. [0081] An E.164 Number is a telephone number that contains an E.164 telephone country code, and that can be dialed on the public telephone network. “E.164” refers to ITU-T Recommendation E.164, “The international public telecommunication numbering plan.” In this document, “phone number” and “telephone number” may be taken to refer to E.164 numbers, which are the phone numbers used for ENUM. [0082] A URI, or Uniform Resource Identifier, is described in RFC 3986. A URI identifies a resource on the Internet. There are two kinds of URIs. The more common is the URL, or Uniform Resource Locator, and it identifies a service and location on the Internet, e.g., http://www.paymentpathways.com. The other is used as a name, the URN, or Uniform Resource Name. The ENUM protocol allows an ENUM subscriber to associate the ENUM subscriber's phone number with URIs for end users to obtain from the DNS. Typically, such URIs may be used to provide specific service-related contact information that could otherwise be found on a business card, including email. addresses, web pages, and SIP addresses for VoIP phone calls. URNs have been used for a range of other kinds of applications, including for identifying publications by encoding the International Standard Book Number (ISBN), in public systems, and for financial messaging by encoding the Society for Worldwide Interbank Financial Telecommunication (SWIFT) address in private systems. [0083] An ENUM Service is a protocol element of the ENUM protocol. It describes the Internet-based service for which a URI may be used. [0084] A NAPTR is a Naming Authority Pointer DNS Resource Record described in several RFCs. ENUM uses NAPTR records. Each NAPTR record is identified by the ENUM domain name of a phone number. Each NAPTR record contains one URI along its ENUM Service. [0085] An ASP is an Application Service Provider, which is in general responsible for a particular URI related to an ENUM Subscriber. For example, the ENUM Subscriber could have a home page on the web that is hosted by a particular ASP. The URI for that web page (in other words, the http address of the page) may be put into a NAPTR in the ENUM Subscriber's ENUM domain. Then an ENUM user could query the subscriber's phone number and get back the address of the subscriber's home page in return. [0086] The Greenlist is the Identity Authentication Bureau described herein, which enables third parties to verify identities for making financial transactions or for obtaining access to restricted information. There is an enrollment process for putting identities into the Greenlist. [0087] The Greenlist Registry is responsible for maintaining the Greenlist database and for maintaining appropriate relationships with the following: [0088] 1.) ENUM Registrar: agent who registers the phone number of the GreenList enrollee into ENUM; [0089] 2.) ENUM Tier II Provider: agent who manages the ENUM domain of the GreenList enrollee and who populates the enrollee's NAPTR records into ENUM; [0090] 3.) GreenList Enroller ASP: agent who assigns the enrollee's GreenList payment address and who thus creates the contents of the NAPTR; and [0091] 4.) GreenList ENUM Agent: agent who has a contractual (liability transfer) relationship with a GreenList Enroller. The purpose of the relationship is to provision the contents of a NAPTR, the “signed” public Payment Address (that goes along with a Bank Account), into the ENUM domain of the enrollee so that it can be searched by those having access to ENUM. The act of “signing” digitally a public Payment Address that originates at a bank is the assurance that ENUM records that are appropriately “signed” can indeed be trusted as true. [0092] The Greenlist Enrollment Process is the process followed by an entity that chooses to have an identity entered into the Greenlist. [0093] The ENUM Registration Process is the process followed by an ENUM Registrant to have his number entered into ENUM. [0094] The ENUM Query Process is the process of using the ENUM protocol to issue a DNS query for a phone number and receiving in return the NAPTR Resource Records, if any, associated with that phone number. [0095] A Transaction Identity Authentication Process is the process of verifying an identity by first using ENUM to retrieve public Greenlist information related to a phone number, and then accessing the private Greenlist, in order to authenticate an identity. [0096] A Linked Credit Account can be a bank account that is designed to filter most or all debit ACH instructions. It is linked to a normal checking account and owners can instruct their bank regarding the frequency with which funds can be “swept” to their traditional bank account, which may or may not be located at the same institution as the LCA. When the Greenlist is used to resolve certain public identifiers to locate a safe, public payment address, it functions as a doorway that only allows funds to travel in one direction, thereby creating a one-way account. No one other than the client can withdraw funds from the Linked Credit Account. Any account that has a system for debits and credits can be modified by subtraction by rendering it incapable of being debited or by rendering it filtered to an extent that only a few approved entities can debit it. This means that even telephone accounts can safely become enabled to receive credits (funds) by adding a layer of Linked Credit Account protection that has, in effect, a similar one-way characteristic for the direction funds can flow. [0097] A Greenlist Licensee is also referred to herein as a Greenlist member bank. [0098] Master Directory [0099] This section describes the concepts and workings of the Master Directory. It includes: Process Descriptions and Data, Edits, and Lookups. [0102] Behind the Linked Credit Account and the associated messaging is the Greenlist Master Directory (“GMD”). The Greenlist is the authoritative address book for all Linked Credit Account and other bank-registered, debit blocked account holders in the world (e.g., UPICs; IBAN; UIDs etc.). In addition to having its own LCA or UPIC account numbers listed for receipt of funds transfers, a GMD provider may transfer funds to EPN UPIC, UID account number destinations or LCAs at EPN and/or non EPN affiliated banks alike. Common to all forms of Linked Credit Accounts is the requirement that an FDIC insured bank (or a bank's properly designated proxy) MUST submit at least a Greenlist ID # to the Internet accessible Master Greenlist Directory. Because the Linked Credit Account and UPICs are for credit deposit only, the account number may safely be publicly published. The Greenlist Master Directory is the preferred method for publicizing that information. [0103] Characteristics of the Master Directory include: A publicly published and Internet accessible Master Directory of accounts for payees (billers); Capability for being deployed over the web either as an independent entity or as an embedded link with pointers within banks' home-banking portal software; A user interface that is web-enabled and provides for retrieval of bank member data using standard web based search methodologies (e.g., Google); A GMD provider is the sole authorized publisher of certified LCA account number(s); Contains payee payment receipt acknowledgment notification preference information; The Master Directory is designed to be synchronized with all local standalone bank Greenlist directory installations; Provides a repository for UPIC customer information in addition to the LCA account information; Highly secured in terms of maintenance and updates to prevent data alteration and miss-direction/interception of funds; and Provides a repository for TripleDES Key Pair information from an authoritative TripleDES Root server source (TBD). [0113] Master Directory Process Descriptions [0114] This section describes processes related to the Master Directory (see FIG. 2 ). These are: Setup of a New Bank Member Record in the Authorized Greenlist Bank Master (see FIG. 3 ). Modify a Bank Member Record within the Authorized Greenlist Bank Master (see FIG. 3 ). Deactivate a Bank Member Record within the Authorized Greenlist Bank Master (see FIG. 3 ). Provide an Update Mechanism to the Greenlist Master Directory (see FIG. 4 ). Provide Nightly Update Feeds to/from Member Bank-Directory sub Systems (see FIG. 5 ). Provide Internet Search Capability of the Greenlist Master Directory (see FIG. 6 ). Assign a valid LCA account range to a licensed member bank in the Authorized Greenlist Bank Master (see FIG. 7 ). [0122] These process descriptions provide detailed information about functional aspects related to setting up and using the Greenlist. These descriptions include Input, Processing, Output, Dependencies, and Data. Setup of a New Bank Member Record in the Authorized Greenlist Bank Master [0123] This process is related to the preferred Master Directory bank setup/maintenance process 200 depicted in FIG. 3 . [0124] A) Input 1. Display entry input screen. a. Greenlist System Administrator 280 enters their authorization id and password to input information to the Greenlist System. b. An action code of add/modify/deactivate is selected. c. The input data source is from the bank's Registration Contract agreement 310 between Greenlist and the financial institution. The data element fields of the Bank Profile Database (see below) are populated from information on the Registration Contract. d. Registration Contract also includes an identification of the block of linked credit account (LCA) numbers 325 each bank has registered with Greenlist. [0130] B) Processing 1. Verify Greenlist user id. entered with the authorization level within the Security Authorization File 245 to perform add/modify/delete functions for bank profile data. 2. Display data input screen for all of the Bank Profile database data elements 200 . 3. Input screens must contain drop down boxes with valid values for specific data fields (e.g., flags for EPN; CHIPS; SWIFT (if applicable)). 4. Check to see that required fields and format are entered. 5. Validate each entry field 225 . 6. Verify Greenlist ID account number is a valid number from the Master Greenlist ID Account file for financial institutions 240 ; or; 7. Verify “LCA number” is a valid Electronic Payment Network (EPN) UPIC account # 265 , or 8. Verify bank's routing number against file of ABA Route Numbers 255 . 9. Validate structure of addresses, city/state/zip combination 260 . 10. Verify e-mail address syntax. [0141] C) Output 1. Post entry to Authorized Greenlist Bank Master file 240 . 2. Print entry in New Bank Audit Maintenance log 270 . 3. Post completion message on entry screen. [0145] D) System Dependencies 1. Bank approved Security System must be in place. [0147] E) Data 1. Data validation sources: a. ABA routing # edit validation file 255 . b. State code validation table 260 . c. Zip code validation table 260 . d. CHIPS and SWIFT validation files (if applicable). e. EPN UPIC master account # list (if applicable) 265 . 2. Data populated/maintained a. Authorized Greenlist Bank Master file 240 . Modify a Bank Member Record Within the Authorized Greenlist Bank Master [0156] This process is related to the preferred Master Directory bank setup/maintenance process 200 depicted in FIG. 3 . [0157] A) Input 1. Greenlist Administrator enters action code (add/modify/delete) and Bank (ABA routing # or financial institution's assigned identifier number) to be modified. 2. Greenlist Administrator modifies bank profile elements. [0160] B) Processing 1. Identify correct bank based on ABA routing #. 2. Display bank profile elements to be modified. 3. Perform validation on any elements that are changed. [0164] C) Output 1. Post entry into the Authorized Greenlist Bank Master Data Base. 2. Post completion message on entry screen. 3. Print entry in New Bank Audit Maintenance log. [0168] D) System Dependencies 1. Security System. [0170] E) Data 1. Data validation sources a. Same as bank enrollment. 2. Data populated/maintained a. Authorized Greenlist Bank Master Data Base. Deactivate a Bank Member Record Within the Authorized Greenlist Bank Master [0175] This process is related to the preferred Master Directory bank setup/maintenance process 200 depicted in FIG. 3 . [0176] A) Input 1. Greenlist Administrator enters action code (add/modify/delete) and Bank (ABA routing # or financial institution's assigned identifier number) to be deactivated. 2. Greenlist Administrator confirms deactivation request. [0179] B) Processing 1. Identify correct bank based on ABA routing #. 2. Display bank profile elements to verify correct bank location to be deactivated. 3. Prompt user “Confirm this bank entry is to be deactivated.” 4. Flag record to prevent future transactions from utilizing the bank being deactivated. [0184] C) Output 1. Post status flag entry to the Authorized Greenlist Bank Master file. 2. Post completion message on entry screen. 3. Post entry activity in the Bank Master audit log. [0188] D) System Dependencies 1. Security system. [0190] E) Data 1. Data validation sources a. None. 2. Data populated/maintained a. Greenlist Bank master database. Provide an Update Mechanism to the Greenlist Master Directory [0195] This process is related to the preferred Master Directory enrollment/maintenance process 230 depicted in FIG. 4 . [0196] A) Input 1. Input screens for bank's customer service representatives for manual entry of member profile enrollment information for bank's customers, or for the bank's customers themselves to enter enrollment information through a bank's home banking portal 280 . The customer populates the record with appropriate information which is then verified and released by the bank into their Greenlist remote directory. 2. Greenlist Bank Authentication process must verify the transaction header is an authorized member within the Authorized Greenlist Bank Master 240 . 3. Greenlist Enrollment System must be built to have capability to accept fixed format file feeds for mass enrollments. System should populate the Master Directory account profile information with the member's transaction. All updates must be received via a valid Greenlist member bank. a. Input record must be fixed format. b. Input record will contain a status flag field of add; modify or delete. 4. Screens a. Input screen must provide for all account profile database data elements. b. Where possible, input screens must contain drop down boxes with valid values for specific data fields (e.g., state, flags for notification preferences, etc.). [0205] B) Processing 1. Access to screen requires a security check to verify individual's id. and password for the bank's Greenlist system administrator has the appropriate security level to permit them to perform maintenance (add; modify; delete) on its customer's profile information. 2. Record status field identifies whether the transaction is an add; modify or deletion record. 3. Edits/Validations 225 : a. Verify Greenlist number is a valid number from the Master Greenlist list assigned (licensed) to that financial institution. b. Verify the bank's routing number against the file of valid ABA route numbers 255 . c. Verify the EPN LCA number is a valid UPIC from the EPN valid account # table 265 . d. Perform verification checks on the structure of the addresses; e-mail addresses; city/state/zip combination 260 . e. Delete transaction records will flag the master record with a delete flag and update the deletion date field with the system process date. f. Modify transaction record types will overlay the current Master Directory fields with the new transaction record updated fields. [0215] C) Output 1. Updated Greenlist Master Directory 235 . 2. Confirmation notification to the user display and to the Success/Failure Report file 275 . [0218] D) Dependencies 1. Process is a real time update process and has no dependency processes. [0220] E) Data 1. Data Validation Sources a. ABA routing table 255 . b. EPN UPIC account numbers 265 . c. US Postal Service zip code file 260 . 2. Data Populated/Maintained a. Authorized Greenlist Bank Master. b. ABA edit validation file. c. State code validation table. d. Zip code validation table. e. CHIPS and SWIFT validation files (if applicable). Provide Nightly Update Feeds to/from Member Bank-Directory Sub Systems [0231] This process is related to the preferred bank subsystem Greenlist update process 215 depicted in FIG. 5 . [0232] A) Input 1. None (nightly batch process). [0234] B) Processing 1. Create a nightly (or real time) formatted replication from the Greenlist Master Directory 235 to the sub-set Member Remote Local Directories 295 , 300 , 305 . 2. VPN will authenticate to check to ensure each bank entry in the bank Master file that is flagged for sub-directory update services is the correct ABA # as indicated in the Greenlist Bank Master file 240 . 3. System will strip off and only forward new adds, modifies and deletes to the member bank sub-directory. 4. A maintenance input screen will be designed to enable VPN information to be updated within the bank sub-system update process. 5. An edit report of those transactions which failed will be generated. [0240] C) Output 1. Bank specific transaction files of incremental changes to the Greenlist Master Directory file 270 . [0242] D) Dependencies 1. Updated Greenlist Master Directory. [0244] E) Data 1. Data Validation Sources a. None. 2. Data Populated/Maintained a. Greenlist Master Directory database. b. Greenlist Master transaction files. Provide Internet Search Capability of the Greenlist Master Directory [0250] This process is related to the preferred Greenlist Internet inquiry process 220 depicted in FIG. 6 . [0251] A) Input 1. Account holder name; bank name; bank location; ABA routing number; address, city, state; LCA number; telephone number; user ID and password. [0253] B) Processing 1. If entered, validate user ID and password. Determine security level. 2. Edit check state entered against Zip/state table 260 . 3. Edit check ABA routing numbers against ABA Routing Table 250 . 4. Locate and display records matching any of the fields of information input. [0258] C) Output 1. Display name; address; bank routing number; LCA number for all records matching input values. [0260] D) System Dependencies 1. None. [0262] E) Data 1. Data Validation Sources a. Zip code File 260 . b. ABA Routing # Table 255 . c. Security Authorization File 245 . Assign a Valid LCA Account Range to a Licensed Member Bank in the Authorized Greenlist Bank Master [0267] This process is related to the preferred Master Directory LCA account assignment/validation process 340 depicted in FIG. 7 . [0268] A) Input 1. Greenlist System Administrator provides user id. and password. 2. Member bank identified. 3. Valid Greenlist account block input. 4. Bank ABA routing number. [0273] B) Processing 1. Check for required fields and format. 2. Validate user id. and password against security database. 3. Display administration homepage. 4. Locate bank record via input ABA #. 5. Flag a valid Greenlist range as assigned or released for reuse. 6. Assign a “new-owner” member bank for the Greenlist range. 7. Update the assignment period (from/to) onto the Greenlist Master file. 8. Based on status flag either add or delete member bank's Greenlist range. 9. Input display is updated with completion notification. [0283] C) Output 1. Post entry in audit activity log. [0285] D) Dependencies 1. Authorized Greenlist Bank Master file record for member bank being updated. 2. LCA Master list database. [0288] E) Data 1. Data validation sources. 2. Security database—verification that administrator Id. has rights to make updates. 3. Greenlist range on Greenlist Master list Database is unassigned. 4. Validate LCA account number syntax and check digit. 5. Verify bank is a current bank member within Authorized Greenlist master Bank database. 6. Data Populated/Maintained. 7. LCA Master List File. [0296] Preferred Master Directory Data, Edits, and Lookups [0297] This section describes data, edits, and lookups related to the Master Directory. This includes: Preferred Financial Institutions Eligible To Operate Greenlist Directories; Bank/Financial Institution Enrollment Data Elements; Customer Enrollment/Profile Setup; Sub-System (Pay Transfer) Directory; Internet Lookup Of Greenlist Master Directory; Master Directory Account Lookup Validation; Greenlist Account Assignment; and Greenlist Master Directory Security/Maintenance Audit Log. Preferred Financial Institutions Eligible to Operate Greenlist Directories: [0306] A. Clearinghouse Institutions [0307] NACHA, Federal Reserve Bank of Cleveland (a.k.a. ACH) or an equivalent clearinghouse institution such as the Electronic Payments Network (EPN), and industry specific clearinghouse institutions such as Affiliated Network Services (through a sponsor bank). [0308] B. Bank Institution [0309] Any bank registered with the American Bankers Association and certified by the respective State Licensing Authority to conduct business in the United States. [0310] C. Non-Bank Financial Institution (NBFI) [0311] Limited to NBFIs that also own or are owned by banks: e.g., Metavante. [0312] Limited to NBFIs that are recognized as proxy institutions for banks: e.g., Zenith Information Systems' alliance partner relationships with banks. [0313] Bank/Financial Institution Enrollment Data Elements [0314] Bank profile data elements for each bank record preferably include the following: elements: Bank (branch) name* Bank address* Bank main phone number* Bank status* Password* ABA 9-digit routing/transit number* Greenlist Master/Directory account number* Bank parent entity Master Directory account number Bank Master Directory primary and alternate administrator contact name(s)* Bank Master Directory administrator contact address* Bank Master Directory administrator contact phone number* Bank Master Directory administrator e-mail address (if applicable) Bank administrator security authorization level* Bank Greenlist issued account number range Bank ACH customer support number Bank CHIPS number (if applicable) Bank CHAPS number (if applicable) Bank IBAN number (if applicable) Bank Federal Electronic Transfer Agent number (if applicable) Bank SWIFT number (if applicable) Bank EPN UPIC account number (if applicable) Requested preferred notification/acknowledgment means of communications method* Create user id (sys generated) Update user id (sys generated) Creation system date (sys generated) Creation system time stamp (sys generated) Update sysdate and time (sys generated) Comments section [0343] *Required fields (must have content (non-special character)) [0344] Edits to be performed by Greenlist on Greenlist Master Bank profile record input: Validate Master Directory account number (check sum digit). Validate ABA routing number against a valid ABA routing directory. Edit check comparison of phone number prefix to zip code for correct geographic location match. There must be a minimum of one bank administrator contact entered. Security authorization level requested must be valid and less than the Payment Pathway's data system administrator's authorization level. If available, validate the MAN; UPIC; CHAPS; CHIPS; SWIFT; ACH numbers against published directories. Note—the EPN UPIC account number may be used in lieu of the Greenlist LCA number. [0000] TABLE 1 BANK DATABASE Bank LCA identifier AN 17 Y LCA record identifier for bank (or branch) Bank LCA Status N  2 Y Value: “01” active; “02” pending; “03” inactive; “04” on hold Bank Fed routing number N  9 N Fed Reserve bank routing/transit number of BBK Bank name ANS 35 N Bank address line 1 ANS 35 N Bank address line 2 ANS 35 N Bank address line 3 ANS 35 N Bank address line 4 ANS 35 N City AN 32 N State/Prov AN 32 N Postal code AN 11 N Country AN  2 N Values defined by ISO-3166 2-letter code Bank's Internet address AN 50 N Master/parent LCA account number AN 17 N Bank's corporate master LCA identifier Bank primary Administrator id. N 10 N Administrator of bank's PayTransfer system Bank primary Administrator security level N  2 N Administrator e-mail address AN 50 N Bank alternate Administrator id. N 10 N Backup Administrator of bank's PayTransfer system Bank alternate Administrator security level N  2 N Alternate Administrator e-mail address AN 50 N Technical contact name at bank AN 80 N Technical contact phone# N 11 N Right justified for non-international Technical alternate contact name at bank AN 80 N Technical alternate contact phone# N 11 N Right justified for non-international Technical contact e-mail address AN 50 N Bank notification preference code AN  1 N Notification preference (e-mail; fax; telephone) Bank notification information AN 26 N E-mail address; notification or fax phone number EPN capable N  1 Y Valid values: “0” not enabled; “1” yes enabled CHIPS capable N  1 Y Valid values: “0” not enabled; “1” yes enabled CHIPS participant number N Y Bank SWIFT/BIC AN 11 BIC code of bank Wire pay N/A 1 AN 35 Y CHIPS/Fedwire payment name/address 1 Wire pay N/A 2 AN 35 Y CHIPS/Fedwire payment name/address 2 Wire pay N/A 3 AN 35 Y CHIPS/Fedwire payment name/address 3 Wire pay N/A 4 AN 35 Y CHIPS/Fedwire payment name/address 4 [0352] As part of the preferred input audit process, after the bank's profile record is successfully initialized, the Greenlist system issues an electronic acknowledgment notification back to the bank (either via e-mail or fax, as indicated by the bank's Requested Notification/Acknowledgment Means of Communication” field). The acknowledgment to the bank is a confirmation that the initialization of the bank-provided record was successful. The acknowledgement message may be similar to the following: [0353] “(BANK NAME) has been successfully initialized on the Greenlist Master Bank file as of (DATE AND TIME). The Greenlist Master Bank account number for (BANK NAME) is (BANK GREENLIST IDENTIFIER NUMBER). Authorized Master Directory administrators are (XYZ Administrators). All account administrative communications will be made to (list the e-mail or fax number). If you have any questions please contact (Greenlist Data Systems Administrator) at (phone number). New Individual/Business entities Master Directory accounts can now be added to your Greenlist system.” [0000] TABLE 2 MASTER DIRECTORY ACCOUNT HOLDER/ENTITY PROFILE LCA identifier AN 17 Y Linked Credit Account debit blocked unique identifier for individual or entity LCA Status N  2 Y Value: “01” active; “02” pending; “03” inactive; “04” on hold UPIC identifier AN 17 Y EPN Universal Payment Identification Code UPIC status N  2 Y Value: “01” active/open; “02” pending; “03” closed LCA effective date D  8 N Effective date when LCA made active (YYYYMMDD) UPIC effective date D  8 N Effective date when UPIC made active (YYYYMMDD) Master/parent LCA account number AN 17 N Corporate parent consolidation rollup account number (if applicable) Bank R/T # N  9 Y Fed Reserve Bank routing/transit # for customer's bank Account holder DDA account# AN 34 N Y DDA # (if EPN capable, max size is 17). Values left-justified/zero fill Taxpayor ID# or FTIN# AN 12 N Y Federal Tax Identification Number Account holder name AN 80 Y Account holder individual or entity Name Entity division name AN 80 Y Business division name (if applicable) Entity short name AN 16 N Shortened name of account holder Address1 AN 64 Y First address line Address line 2 AN 64 Y Second address line of address Address line 3 AN 64 Y Third address line Address line 4 AN 64 Y Fourth address line City AN 32 Y State/Prov AN 32 Y Postal code AN 11 Y Country AN  2 Y Values defined by ISO-3166 2-letter code Account holder/business entity phone N 11 N Right justified for non-international number Account holder mobile phone number N 11 N Y Right justified for non-international Account holder fax phone number N 11 N Y Right justified for non-international Technical contact name at entity AN 80 N Y Technical contact phone# N 11 N Y Technical alternate contact name at entity AN 80 N Y Technical alternate contact phone# N 11 N Y Account holder e-mail address AN 50 N Y Account holder notification preference AN  1 N Y Notification preference (“00” none; “1” e-mail; “2” fax; code “3” telephone) Account holder notification information AN 26 N Y E-mail address; notification or fax phone number Accounting software package N  2 N Y A/P and A/R software package of account holder Accounting software update flag N  1 N Y “0” no; “1” yes SIC Business code N  4 Y Standard industrial classification code DUNS Id N 10 Y D&B D-U-N-S number Thomas Register# N 10 Y Thomas Global Registry company identifier Payment network preference of biller N  1 Y “1” ACH; “2” SWIFT; “3” Fedwire; “4” CHIPS; “5” other BIC code AN 11 N SWIFT BIC code BEI code AN 11 N SWIFT business entity identifier IBAN code N 34 N International bank account number Customer Enrollment/Profile Setup: [0354] The actual process of establishing a new LCA account begins at the payee's bank. The bank may send out marketing forms announcing this new Greenlist product to their entire existing base of customers or include the option for new accounts. The Greenlist account holder can request listing on the Internet accessible Greenlist Master Directory. The setup can also be initiated by the bank's extended customer service function (e.g., healthcare clinic/dentists registration desk; school administration office; trade association/union; company payroll or shareholder relations department; company accounts receivable department, insurance carriers; credit card company, etc.). The system preferably accommodates potential mass batch input of member accounts from these types of organizations or entities on behalf of a member bank. In each of these “representative” initiated requests, however, there is still the requirement that each Individual/Business entity's affiliated bank or financial institution must have a pre-established Bank Profile account number established on the Greenlist Master Directory, the FED-ACH or the Electronic Payment Network's UPIC Directory. [0355] The enrollment system preferably is a browser-based registration system. The entry point preferably is one of the following: (1) a customer user interface via a link off the bank's on-line home banking portal site; (2) a kiosk banking station within the bank; or (3) via an on-site terminal (workstation) at a bank customer service desk. In the case of the latter, the individual or business entity customer would either be talking or providing information to the customer service representative in person or via telephone. [0356] In order for a “member” (biller/payee) of that bank to reside on the Greenlist Master Directory, a business entity or individual must first have established an LCA and a DDA (Demand Deposit Account) at the Greenlist subscribing Greenlist affiliated bank or an authorized partner organization bank (e.g., EPN). [0357] In order to access the Greenlist system registration screens, bank personnel or the bank customer member must supply their bank DDA and password. The DDA number and password is the front-end security mechanism for the account holder's portion of the Greenlist system. The DDA number is validated against the bank's active account database. The banking password is critical to prevent an intruder knowing a business entity or individual's bank demand deposit account number from creating a “redirecting LCA number” to his or her own LCA account. The Greenlist validation process would have trapped and flagged any “redirections” as the normal process would be a “remove and replace” by the system. [0358] Through the bank's on-line bank portal system, the business or individual “member” will make a request to their bank for a mobile payment capability (preferably utilizing a debit-filtered account variation of the LCA (i.e., linked credit account (LCA or UPIC for EPN Network bank). The LCA is linked to the DDA account. A secure hot-link from the home banking-portal to the bank's local Greenlist payment system guides the member's enrollment. [0359] New LCA member information requires name/address information, fields such as method of notification (e.g., fax, e-mail, telephone), and provisions for future use of other IDs (e.g., UPIC; SS #; IBAN #; FEIN #; DUNS #; industry). [0360] Note—the communication aspect of the system preferably allows for decentralized multi-branch banking systems to communicate all branch submissions to their centralized parent site for consolidation and nightly re-transmission to the Master Directory System. That parent bank may elect to push back to its entire branch Greenlist system locations all records relating to all of the banking systems member branch banks so each branch would have a Sub-Master Directory listing of all account holders for that entire banking system's member base. [0361] The Greenlist Master Directory System performs edits and validation checking. Some of the edits include a verification of the bank's ABA number, LCA, UPIC, and IBAN. [0362] After the new bank customer's LCA account is set up on the Master Directory, the new account member is sent a message from their bank similar to the following: [0363] “(BANK NAME) is pleased to inform you your new (BANK NAME) LCA account and Master Directory Greenlist accounts have been initialized on (system date) and is now operational to receive funds.” Your LCA account number is (LCA Individual/Business entity account number). It is suggested business entities include the LCA number on the remittance portion of your invoices with instructions to your payors to use this secure electronic account number in lieu of paper checks for making payments. As a reminder, please note the LCA account can only be used to receive funds. Any debit originations will be blocked. No withdrawal of funds can be made directly from this secure account. Monies received into the LCA account will be swept into your demand deposit account(s) on a regular basis according to the schedule established with (bank name).” [0364] The system will also create and send a notification audit report to the bank advising of the successful or unsuccessful processing of the previous night's customer directory account maintenance. [0365] The member enrollment process is complete at this stage. The “member's” record containing their new LCA (or UPIC) account number on the Greenlist Master Directory is at this point searchable via the Internet. The new Greenlist/LCA Account is active and ready to begin receiving payments. [0366] Another embodiment provides for a mass batch sign-up of individual consumers from an organization (e.g., union, University, clearinghouse members, and groups such as AARP, etc.) under an unassigned-“pending-bank”-assignment/bank-activation category. The organization of individual members is “shopped out” to a banking entity that is already a member or up-coming new member of the Greenlist Directory or EPN networks. [0367] The profile data elements to be captured for each Individual/Business entity include: [0368] Individual/Business Entity LCA Profile Record Individuals Greenlist account # Bank's 9 Digit ABA routing/transit number* Individual/Business entity LCA (National Billers Directory) number Individual/Business entity's bank demand deposit account (DDA) number Individual/business entity name* Individual/Business entity complete address* Individual/Business entity phone number* Individual/Business entity cell phone number (if applicable) International destination flag* Loyalty points field 1 or 10 Individual/Business entity fax number (if applicable) Individual/Business entity e-mail number (if applicable) Business entity Federal Tax Id # (if applicable) Business entity DUNS # (if applicable) Business entity industry Business entity LCA contact name Business entity LCA contact telephone Individual/Business entity UPIC number (if applicable) Individual social security # (potentially needed for insurance and healthcare providers) Individual/Business entity consolidation parent LCA number (if applicable) Individual/Business entity preferred communication method of billing notification/acknowledgment* [0390] (Depending on method chosen, data to facilitate that becomes a required field) Individual/Business entity preferred communication method of funds receipt notification/acknowledgment* [0392] (Depending on method chosen, data to facilitate that becomes a required field) Individual/Business entity status (new/existing/terminated/pending/hold**) Account system date of creation Account time stamp date of creation Bank personnel Greenlist Directory system ID Number Extended comments field [0398] *Required fields must have content (non-special character). [0399] Edits to be Performed by the Bank's Local Greenlist System Include: Validate field lengths for data entered. Validate LCA number (check digit sum). Validation of the UPIC numbers from an EPN UPIC verification file. Valid assigned Greenlist range for bank entity for NEW Individual LCA registrations. Range zip code phone prefix compare for valid geographic area. Note—a bank assigned “Hold” status for an Individual would have funds blocked from being swept. [0406] Note—whenever possible the data input fields preferably are pre-populated with existing bank information stored in the Greenlist (e.g., bank LCA number and ABA number) system or the banks own member account systems. [0407] Note—The bank's stored routing number in the Greenlist System and the LCA (next available sequential within the bank's block of numbers) will be system generated by the Greenlist system. The system preferably tracks any change to an individual or business organization's bank affiliation. The combination of an individual/business Greenlist account and the affiliated bank's routing number provides for the unique record identifier for financial transactions and acknowledgments within the Greenlist system. [0409] When an individual closes their demand account at a financial institution, it is the responsibility of that Greenlist member, as part of their termination process, to submit a standard Individual/Business entity LCA change of status (inactive) transaction. The Greenlist Master Directory will receive update transactions to reflect the change in status from “active” to “in-active” for the LCA account number. Procedurally, whenever an LCA customer changes their profile demographic information on their demand account, the bank will at the same time submit update maintenance to their local Greenlist system. This information preferably flows through and updates the Greenlist Master Directory records during nightly batch update processing. The LCA customer may be notified of the time necessary for the change to take effect (propagate across the entire system). Bank Sub-System (Pay Transfer) Directory [0410] Individual Bank Directories must be registered in order to be certified and maintained by Greenlist. Following this procedure will ensure a core infrastructure that financial institutions and enterprises can rely on to eliminate fraud and cost associated with paper and other single-factor payment methods such as off-line debit and credit cards. [0411] The local Greenlist System's look and feel may be “private-label” branded according to the look and feel standards the bank already employs for their own home-banking portal(s). The individual bank may be responsible for any coding necessary to incorporate the Greenlist Master Directory into the bank's current home banking portal. [0412] After agreements are signed, Greenlist may physically install a standalone Greenlist hardware/software system within the bank's firewalled environment. The necessary VPN communications links to the Master Directory System may be established and security directory management technology may be deployed and activated. [0413] Assisted by the Greenlist “Directory Administrator” or authorized banking personnel, the bank's authorized “Greenlist Administrator” would register the bank by completing the bank profile registration screen on their newly installed Greenlist system. [0414] Completion of this process generates a “pending bank profile” record and an update transaction file that is transmitted via secure VPN connection to the Greenlist Master Directory System. The bank's information is validated/verified (e.g., validated against Fed bank routing #; valid Greenlist authorized bank account #; valid UPIC number, etc.) by the Master Directory System. [0415] A successful validation will result in a “confirmation transaction record” being generated by the Greenlist Master Directory and transmitted back to the bank's Greenlist system to initialize the system and change the bank's system status field from a “pending” to an “active” status. Internet Lookup of Greenlist Master Directory [0416] Operationally, in order to use Greenlist for payment and settlement processing, an individual or entity (seller) wishing to bill a buyer (payor) preferably requests the buyer to deposit funds into a biller's LCA account. The buyer can locate the seller's account number by doing an Internet search on the Greenlist Master Directory. [0417] In order to facilitate the use of the Greenlist, billers or those who are to receive claim settlement (i.e., insurance) checks or stipend checks from government or other sources will be requested through the biller's (payee) bank and Greenlist marketing literature to notify those payor entities to route payments via the Greenlist Mobile Payment Network, ATM Networks, Electronic Payment Network, or Federal ACH Network. They will be requested to provide their bank routing and LCA or UPIC account number to the payor. [0418] All Individual/Business entity LCA and UPIC account numbers are open for public query/search. (Special security logic may be used help to require registration of the viewer in order to access demand deposit account numbers should the business requirements of the system permit inclusion of actual bank account numbers within the Directory as record keys. Access to the banking profile record information within the Greenlist Master Directory is also open for unrestricted public viewing [0419] The Greenlist Master Directory site is accessible via Internet link or through any public Internet search engine (e.g., Google). Master Directory Account Lookup Validation [0420] The Master Directory's successive levels of search criteria for biller account record lookup preferably include: Name (Individual or Business Entity) Type of entity drop down (e.g., government, telephone companies, gas and electric utilities) State or geographic region drop down Address (partial and full) Telephone number Bank name (and/or routing number) Bank Branch location [0428] The search will either reveal the biller LCA, UPIC number and bank routing information or return a message indicating an account number was not found or is unavailable. If the “not found” condition occurs, the system will also display information explaining how one can go about joining the Greenlist system. [0429] Note—an individual or business may have multiple account numbers if they perform financial transactions at multiple banks. [0430] It is preferable that a participating origin bank for the consumer establish a relationship with an authorized Greenlist financial institution (or EPN bank) or influence their existing bank to join the Greenlist system. That financial institution will be registered and have operational within its physical environment a Greenlist system. The enrollment system functionality built within the Greenlist system maintains a local directory and profile of all participating business entities and consumers that have enabled LCA accounts at the bank. The enrollment function of the Greenlist System maintains the replication of information between itself and the Master Directory. The Master Directory provides its members a national and international visibility via the Internet. Greenlist Account Assignment [0431] As indicated earlier, in one embodiment, as part of the contractual arrangement with the Greenlist Directory Services organization, each bank “rents for use” its block of registered Greenlist account numbers. As long as the owner of the LCA account is assigned to the bank that subscribes to the LCA service, the bank pays Greenlist a monthly fee for all registered (active and inactive) reserved LCA authorized accounts it “controls”. The Greenlist Directory System may require a process and system for monitoring and tracking these Greenlist assets. The account numbers are registered to the lessee bank for the period during which the bank's member has a demand deposit account at the bank. The tracking system will record the start and end dates for the period during which the account numbers were registered to that bank. Greenlist Master Directory Security/Maintenance Audit Log [0432] The Master Directory update/maintenance process logic provides an audit trail of any changes made to the Master Directory: Record for any add, modify and deletion of data within the Bank Profile Table. Password-based security in order for the bank's authorized systems administrator to log on to the Greenlist Master Directory to perform Directory maintenance for their bank. Security mechanism for the Greenlist Master Directory will be designed to provide for four security authorization levels: A. Level 3—Authority to view only (for bank staff; business entities and individual consumers; Greenlist non-system administrator personnel). B. Level 2—Authority to change indicative bank data. C. Level 1—Authority to add/delete a record. D. Level 0—Greenlist Systems Data Administrator. Audit trail with date and time stamp including the ID of the individual making changes. A record of any change made to the Directory's Bank Profile Table will be recorded in the PP Master and the Master Maintenance Audit Log tables. [0442] Maintenance Audit Log Table Content: Bank Master number Greenlist Individual's id. Bank systems administrator id. System date System time stamp Transaction (add/delete) status change from Transaction (add/delete) status change to Transaction (change) field name Transaction (change) field from Transaction (change) field to KEY TO FIGURES [0453] FIG. 1 [0454] 100 Greenlist [0455] 105 (points to Greenlist databases) [0456] 110 Bank [0457] 115 (points to Bank databases) [0458] 120 Subscriber [0459] 130 DNS [0460] 140 Transaction Processing [0461] 150 Initiator [0462] FIG. 2 [0463] 200 New Member Bank Setup Process [0464] 205 Licensee Number Assignment Process [0465] 210 GL Security Authentication Process [0466] 215 Nightly Member . . . Update Process [0467] 220 “Google” Search Process [0468] 225 Input validation Edits [0469] 230 Master Directory Update Process [0470] 235 GL Master Directory [0471] 240 Authorized GL Bank Master [0472] 245 Security Authorization File [0473] 250 Licensee Master File [0474] 255 ABA Banking Validation [0475] 260 ZIP/State Table [0476] 265 UPIC Master [0477] 270 Audit Log [0478] 275 Confirmation Reports [0479] 280 New Enrollment Input From Member Banks [0480] 285 Bank Enrollment by GL Sys Admin [0481] 290 Directory Internet Search Inquiry [0482] 295 Member Bank 1 Remote . . . [0483] 300 Member Bank 2 Remote . . . [0484] 305 Member Bank 3 Remote . . . [0485] FIG. 3 [0486] 200 New Member Bank Setup Process [0487] 205 Licensee Number Assignment Process [0488] 225 Bank Input validation Edits [0489] 240 Authorized GL Bank Master File [0490] 245 Security Authorization File [0491] 250 Licensee Master List File [0492] 255 ABA Banking Validation [0493] 260 New Bank Enrollment Input . . . [0494] 260 ZIP/State Table [0495] 270 New Bank Audit Maintenance Log [0496] 310 Contractual . . . [0497] FIG. 4 [0498] 210 GL Bank Authentication/Authorization Process [0499] 225 Input Validation Edits [0500] 230 Master Directory Update Process [0501] 235 Current GL Master Directory [0502] 235 Updated GL Master Directory [0503] 240 Authorized GL Bank Master [0504] 250 Licensee Master File [0505] 255 ABA Routing # [0506] 260 Zip/State Table [0507] 265 UPIC Master [0508] 275 Confirmation Success/Failure Reports [0509] 280 New Enrollment Input Requests . . . [0510] 280 New Mass Enrollment Input Requests . . . [0511] 315 File sort [0512] FIG. 5 [0513] 215 Nightly Member Bank(s) . . . Update Process [0514] 235 GL Master Directory [0515] 240 Authorized GL Bank Master File [0516] 270 Audit Log [0517] 295 Member Bank 1 Remote . . . [0518] 300 Member Bank 2 Remote . . . [0519] 305 Member Bank 3 Remote . . . [0520] 320 Communicate/Update Bank sub-Systems [0521] FIG. 6 [0522] 290 Directory Internet Search Inquiry [0523] 235 GL Master Directory [0524] 245 Security Authorization File [0525] 220 “Google” Directory Search Process [0526] 260 ZIP/State Table [0527] 240 Authorized GL Bank Master File [0528] 255 ABA Bank Routing Table [0529] FIG. 7 [0530] 210 GL Security Authentication Process [0531] 225 New Enrollments Input Validation Edits [0532] 230 Master Directory Update Process [0533] 235 GL Directory Master List File [0534] 240 Authorized GL Bank Master [0535] 245 Security Authorization File [0536] 265 UPIC Master [0537] 325 LCA Block Assignments . . . [0538] 330 EPN Update File [0539] 335 Licensee File Update Process [0540] 340 Licensee Validation Process Healthcare Embodiment [0541] Healthcare clearinghouses are now addressing the emerging needs for Electronic Remittance Advisory (ERA) payments (i.e., HIPAA-compliant medical payments). ERAs are mandated for Medicaid and Medicare, and many insurance carriers are implementing ERAs for all payments. These payment communities all require the ability to settle payments without today's security risks and payment delays. Here is how one embodiment of the invention works for healthcare: [0542] The use of a Greenlist, as discussed above, eliminates the potential risk of overdraft associated with DebitACHs by issuing CreditACHs. In addition to the above-mentioned efficiencies associated with authentication services provided by parties in the position to do so with the least cost (e.g., banks), in the healthcare context that use is augmented by two, more subtle, uses. First, reversal of the way that recurring billers are paid, putting control of payment release into the hands of the consumer or small business. Second, when a small or even medium sized business is a health care provider and the party billed is an insurance carrier; up to now these entities have been reluctant to provide their bank account information to the carriers for fear that payments for charges that are later determined to NOT be covered by an insurance policy could be debited or “clawed back” immediately, instead of being reconciled in the next month's payment cycle. [0545] Banks functioning as Greenlist registrars preferably enroll small businesses (such as health care providers) in the Greenlist and assess service fees. A portion of this monthly fee is net income, and a portion of the fee is used as net income for registrars to list debit blocked (or debit filtered) payment addresses in the public Greenlist. In Healthcare, the potential exists for a Clearinghouse and/or any federation banks serving Insurance Carriers to institute a company that functions as a proxy registrar (for banks) and perform Greenlist enrollment functions by obtaining a system use license. [0546] The Greenlist performs numerous services that are in demand today among Insurance Carriers. The Greenlist: [0547] (a) Allows private access to a complete Greenlist data field. For instance, social security numbers could be exposed to licensed participants among the carriers and their banks. This is useful to resolve Unique Identifiers pertaining to consumer identities into safe “where to pay” payment addresses (payments via CreditACH). Also, Clearinghouse identifiers may be obtained for PHI delivery (e.g. NPI, TaxID, TSO, etc.) [0548] (b) Accepts HIPAA X12 835/ERA mass enrollment transaction files from corporations (consumers who have opted in to be given safe and Greenlisted payment addresses so their insurance co-pay reimbursements can be electronically deposited). [0549] (c) Allows for the clearinghouse to act as a Claim/EFT clearinghouse for payors. Thus, as more and more payors begin to perform real time adjudication, the same clearinghouse that is processing the claims can also return the Greenlist-routed status responses with payment information and/or payment confirmation information, even for payors that have not yet begun to offer 835s/ERAs. The payors (insurance carriers) can contract for all their needs with the clearinghouse without having separate bank relationships for electronic payments to providers. [0550] (d) Allows for mass Greenlist enrollment at the time of ERA enrollment, particularly in the early phases when providers are not being enrolled, for the most part, one by one, but are being “mass enrolled.” [0551] For every provider enrolled by a clearinghouse, a number of “placeholder” Greenlist enrollment “slots” will be allocated by default, whether or not the provider has elected to use the Greenlist yet. Then if the healthcare provider decides to use the Greenlist, they merely indicate this to their Practice Management System (PMS) vendor or the clearinghouse and the PMS or clearinghouse simply flips the switch for that provider to trigger the registration process for creation and assignment of debit blocked bank accounts being created by the bank(s) registrars that are affiliated with the Clearinghouse. [0552] The Greenlist Directory provider performs numerous services that are in demand today among Health Care Providers of any size. The benefits are equally the same for clinics, large provider groups and possibly small hospitals that do not already have a system in place. The benefits include: no chance of payment reversals since payment addresses are debit-blocked (debit filtered); notification by Greenlist switch (optional) when payments arrive via method of customer's choosing. (email, voicemail, SMS); a PrivatePhone number (e.g., from NetZero) for voicemail so provider's business lines are not called with payment delivery notifications; avoids the worry by the provider that the carrier is not working directly with “their” bank since the system is bank neutral from the provider perspective; HIPAA compliant payment method; the same system (Greenlist) can be used to receive payments regardless of how many insurance carriers the provider works with (benefit of the clearinghouse being the intermediary); and can easily accommodate provider offices where each physician or dentist wants to be a separate “pay to.” [0560] Currently, many provider offices that wish to have payments go to specific TaxIDs must allow the payments to go to one TaxID and perform reconciliation at a later time because the payor cannot accommodate multiple payments to a single TaxID. [0561] In one embodiment, the Greenlist allows the clearinghouse to use the ERA/rendering provider to determine the payee and then distribute the payments to specific TaxIDs while also indicating this on the ERA so that the provider office/providers themselves can see the breakdown by line item and to whom the payment was distributed. Features of this embodiment include: The Greenlist storing the history of payments to allow the provider a second avenue for reconciling payor to provider payments distinct and separate from overall receivables. Periodic “keep alive” testing of payee addresses. Bank registrars warrant that payments coming IN to payees that are registered will be incapable of being clawed back because the Greenlisted e-lockbox account is a filtered DDA. [0564] There are forces moving toward Greenlist usage among healthcare clearinghouses and insurance companies migration to ERA payments. Already, ERA payments to ACH payment addresses are mandated by Medicaid/Medicare [0565] As of Oct. 1, 2006, Medicaid will no longer allow the use of paper remittance for any provider that has elected or decides to elect to received ERAs (electronic versions of the explanation of benefits). An inherent part of the ERA is the inclusion of payment information and ultimately, the coordination of payments. The ERA's value is diminished anytime it is delivered without payment information. Thus, CMS, the ADA and the AMA and the state societies (as well as industry organizations) are all pushing, primarily the clearinghouses, to derive a method whereby the provider and payor “can do what they do today” and the clearinghouse take on also being an EFT/ACH clearinghouse coordinating payments with the claim (it is most logical at this point in the claim processing process). [0566] The bottom line is that the ERA, which will eventually be mandated (not allowing providers to elect, but telling providers that they can only be a part of the carrier network if they are willing to receive ERAs over paper), cannot be effective, without the coordination of payment information. Medicaid is leading the charge and carriers will follow suit as the check printing and Explanation of Benefits (EoB) printing processes are inherently far more expensive than their electronic counterparts. Carriers now are addressing the objectives of lowering operational overhead for mail room, customer support, imaging and printing systems, etc. This was not true in previous years because new process implementations mandated by HIPAA overwhelmed the industry. In 2006, many payors are already offering incentives to providers who are willing to give up paper remittance for ERAs. This shift in priorities that are now being addressed by providers of all size, has tidal force. The Greenlist solves an important problem that is a barrier to full and speedy implementation of HIPAA 835/ERA payments: provider reluctance to supply a bank account number. Social Networking Embodiments [0567] The next step in the evolution of social networks will be payment transactions between two parties. Complementing each social network's directory of individuals will be a directory of payment addresses, the Greenlist, which identifies and validates each individual or commercial entity as real. This will allow consumers and businesses to electronically make payments or authorize account access through the social network. [0568] Banks will view social networking as an ideal market to drive demand among a huge cadre of financially viable, young consumers. Social networks are ideally positioned, therefore, to be Greenlist distribution channels. [0569] Today, two-thirds of U.S. youths have profiles on multiple networks—and 53 percent would join another if it were compelling enough. With potentially millions of U.S. consumers willingly Greenlisted, the motivation for leading banks to facilitate the enrollment process is higher. Similarly, merchants will be motivated to list themselves because of the spending power of this segment. Finally, the Greenlist allows banks to market to an emerging generation of customers that the banks have failed to connect with thus far. “Meet them where they are” is the right approach and this demographic group lives online and wants new payment services. [0570] Today, banks spend an average of $284/customer for marketing expenses devoted exclusively to acquiring new customers. This market pull strategy may be used to bring those young customers, in their millions, to the banks at a hugely reduced marketing cost. Such web portals offer the largest and fastest opportunity to trigger rapid adoption. [0571] However, social networking has taught the practice of masking one's true identity behind false names, false personas, etc. The transfer of information assets does not always flow downward from a repository to a consumer of information. For example, consumers, highly practiced in the art of bearing false witness with regard to their true identity can and do post false information on Wikipedia. Already this has resulted in discovery and permanent blocking of congressional staffers from making edits, posts, or removal of information pertaining to U.S. lawmakers. Greenlist, in one embodiment, will perform the role of switching an authentication request (that a person is who he says he is) to the least cost, most trusted arbiter of identity authentication: the bank. In our view, the banks will perform authentication for a small fee that will assign premium value to posts in repositories such as Wikipedia. In fact, a user, wishing to remain anonymous but identifiable after a fee is paid, can and will make posts in the future to free and paid repository information services alike. [0572] Finally, the implication for proving membership exists in paid subscription services when the user is moving from location to location and seeking access to film and music downloads to entertain friends is the culmination of the role Greenlist plays as the penultimate application layer switch. Embodiments for Communities of Interest [0573] In other embodiments, the invention may be used for communities of interest for which identifiers, authentication, and transactions are relevant. Examples of such communities of interest include digital rights management, air travel or ticket reservations or confirmations, and shippers and receivers of merchandise. A community of interest may operate with information held in either a public or a private set of databases. For each such community of interest, an embodiment comprises elements including the following, with labels as in FIG. 1 : An individual, user, consumer, company, or other identifiable entity that can be a Greenlist subscriber 120 . An organization, company, or other entity that can be Greenlist licensee 110 . The licensee acts as registrar, hosts the relevant remote portion of Greenlist data 115 , and handles authorization and possibly notification functions. An identifier that applies to each subscriber. The identifier is determined by the community of interest. The identifier may be associated with the subscriber in general, or the identifier may be generated for specific instances of use (e.g., incorporating a confirmation number for a purchased good or service). A transaction processor 140 that uses the Greenlist licensee for authentication and authorization based on the subscriber's identifier. The transaction processor is, or is acting on the behalf of, a risk bearer that is responsible for providing the assets to the particular community of interest. A public or private database 130 for lookups, including a public or private ENUM lookup that maps a subscriber's phone number to the subscriber's identifier, as appropriate for the particular community of interest. [0579] In the payments embodiments described above, a bank acts as a Greenlist licensee, and a subscriber's identifier may be a Linked Credit Account (LCA). The transactions are payment transfers. [0580] In a healthcare embodiment described above, a bank also acts as a Greenlist licensee. The transactions may involve payment transfers and/or routine or emergency access to medical records and notifications are made to transaction participants in the manner specified by the participants themselves during the time of registration. Notification preferences may be revised or enhanced by conditional assignments of parties to be notified, in what manner, etc. An example of this would be for first responders, having rights to access medical information via Greenlist's public identifiers without the delay of additional authentication and authorization that the owner of the information assets being accessed normally requires. The owner could be unconscious, for instance. Notification that medical information has been accessed by a first responder might be sent to the owner of the information, his health care provider (such as his primary physician), and his immediate family member. [0581] For a digital rights community of interest, a subscriber would be assigned a subscription identifier. A Greenlist licensee (e.g., a bank or other company so licensed to be a Greenlist Registrar) would authenticate users to a risk-bearer that manages the digital asset. For example, an individual with a media subscription may want to download or play a video or piece of music. A media company would authenticate the individual via the licensee. This example is analogous to a payments transaction: for payments, the asset is financial; for this example, the asset is digital. [0582] For a tickets-based community of interest, examples include a user accessing and printing hotel or event ticket reservations or confirmations, or a passenger printing out an airline boarding pass. The identifier may incorporate a confirmation number for the purchased ticket or room reservation. In these examples, the risk-bearer is responsible for the information-based asset (the ticket, confirmation, or boarding pass). The risk-bearer wants to authenticate a user who requests access, such as for printing. Again, this is analogous with the use of the invention in a payments embodiment. [0583] For shipping and receiving communities, the risk-bearer is responsible for a physical asset. In one example, a shipper will not ship or deliver goods until a user has been authenticated as a legitimate receiver of the goods. In another example, a merchant will not release goods for shipment until receipt of payment has been confirmed. The identifier would be appropriate to the particular transaction and/or transfer of a physical asset. [0584] This embodiment relates to the following patents related to dissemination of product information from manufacturers: U.S. Pat. Nos. 5,913,210; 6,154,738; 6,418,441; 7,117,227. See also U.S. Pat. App. Pub. No. 2006/0011720. [0585] U.S. Pat. No. 6,418,441 discloses and claims the “Web Register.” A block diagram (FIG. 6 in the patent) illustrates how a retailer's inventory control system sends UPC codes and on-hand quantities to a shared server which performs sales transactions for the retailers. The patent proposes that payments be made using standard credit card methods implemented by the shared sales server—but Greenlist is an enhancement to this prior art that further reduces costs associated with authentication of transaction parties when physical assets are transacted (moved), not monetary or informational assets. U.S. Pat. No. 7,117,227 covers the Object Name System (ONS) mechanism for cross-referencing electronic product codes (from RFID tags) to the internet addresses from which information about the tagged products can be retrieved. Pending application 2006/0011720 contains claims that will cover the Global Data Synchronization Network which has become the standard mechanism for providing product information from manufacturers to their trading partners. [0586] Although particular embodiments of the invention have been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made thereof by those skilled in the art without departing from the scope of the invention, which should be determined exclusively from the plain wording of the appended claims. Any details in the specification that are not included in the claims themselves should not be construed as limiting the scope of the invention.

The Greenlist tool provides payors desiring to pay a merchant a means to locate, validate and effect the transfer of assets to another party by routing transaction requests to a third party that functions as the transaction enabler. This task is performed without divulging confidential information about transactors while assigning liability for certain risk consequences to the lowest cost risk bearers: banks. Greenlist verifies identities before making financial transactions or before obtaining access to restricted information. The Greenlist can be completely trusted by risk-bearers. Liability for risk can be transferred to the registrars of the information contained within the registry. This liability transfer substantially reduces the payor's cost of bearing risks. Banks or third parties responsible for certifying that someone or some entity claiming to be an authorized party is not an impostor can now offer new levels of service at a substantially lower cost for a variety of transactions.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of application Ser. No. 13/225,131, filed on Sep. 2, 2011, which is a divisional of application Ser. No. 11/027,860, filed on Dec. 30, 2004, issued on Sep. 27, 2011 as U.S. Pat. No. 8,024,898, the contents of which are fully incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to a system and method for finishing fenestration openings. BACKGROUND OF THE INVENTION [0003] General contractors engaged in the construction of a commercial or residential building are responsible for scheduling various subcontractors to complete their assigned tasks in a timely manner. When a certain subcontractor's work is delayed for some reason, further delays may be caused for other subcontractors whose tasks are dependent on the first subcontractor. For instance, plumbing and electrical work must be completed before interior drywall can be hung; likewise painting and finishing cannot proceed until the drywall is hung. To the extent that a job can be planned so that as few subcontractors are dependent on the completion of each other's work as possible, a smoother job with fewer delays is likely to result. [0004] While better scheduling and planning on the part of the general contractor can reduce these bottlenecks, some are unavoidable due to requirements imposed by current building materials. For example, fenestration openings are unfinished openings in the side of a building which will ultimately receive a window or door assembly. Currently, windows are delivered by the manufacturer having a frame which is attached to the framing members of the fenestration opening. Until this frame is installed, the finishing crews, which apply the exterior finish such as plastering to the building as well as the interior drywall crews, cannot complete their work. Accordingly, delays in shipment and installation of the windows and frames lead to significant problems in work scheduling for the building as a whole, which can potentially cause an entire job to fall behind schedule. [0005] A need exists for a system and method which reduces the need for a high degree of coordination between subcontractors. With such a system and method, the burden on the window and door manufacturers to deliver on a tight schedule is reduced, and the general contractor regains a degree of control over his schedule without worrying about being held up by his custom window and door suppliers not delivering on time. SUMMARY OF THE INVENTION [0006] Accordingly, a fenestration cap system is provided as a separate piece from the frame of the window. The fenestration cap can be installed prior to the delivery of the widows and accompanying frames, and allows interior and exterior finishing to be completed without having to install the window and door systems. This allows more time for custom window and door orders to be filled by the supplier without holding up progress in other areas of the job. The waiting for the actual windows to arrive and be installed is no longer one of the critical paths of the job schedule, and may be completed at the convenience of the contractor. [0007] This system is compatible with the frames of major door and window suppliers, and gives consumers the flexibility to choose the windows and doors that best fit their specific needs without being forced to make a selection due to manufacturer lead times. Furthermore, the present system is easy to install, and can be done by tradesmen with minimal training. The inclusion in certain embodiments of the present invention of flanges and stops reduces the need for careful measuring and placement of finishing materials such as drywall sheeting. [0008] The fenestration cap system allows window and door openings to be made ready to receive their corresponding accessories, while at the same time being easily made weatherproof in the absence of these accessories with the addition of a simple piece of panel or sheeting. [0009] Additional benefits are provided if accessories such as windows and doors are installed after finishing crews complete their work, which may include the application of plaster to the outside of the storefront, or the installation of drywall along the inside. In this case, The window and door systems installed within the fenestration cap do not need to be masked off by the finishing crews, and they are not in danger of being damaged by the finishing crews. [0010] In one embodiment of the present fenestration cap system, future window replacement can be achieved by simply removing the window fasteners holding the window and possibly the frame within the fenestration cap, cutting out the perimeter window sealant, and sliding the window out leaving the integrity of the structural and building substrates in a finished undisturbed state. [0011] In an exemplary embodiment, a window sill comprises a structural base having a first side and a second side, a fenestration cap attached to the structural base, a window frame mounted on the fenestration cap, and finish elements applied to the structural base and adjacent to the fenestration cap. The window frame may be removed from the fenestration cap without disturbing the finish elements. [0012] In an alternative embodiment, a fenestration cap comprises a first surface for receiving a window and a second surface attached to the first surface for attachment to a fenestration opening. The window is separably detachable from the first surface and the fenestration opening is detachable from the second surface. Furthermore, detachability of the window from the first surface is independent of detachability of the fenestration opening from the second surface. [0013] A method of installing a window in a window opening comprises providing a window opening and preparing the window opening for receiving a fenestration cap, installing a fenestration cap by placement within and attachment to the window opening in a primary step, and installing a window within the window opening by placement within and attachment to the fenestration cap in a secondary step. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 shows a side view of a prior art commercial window assembly; [0015] FIG. 2 shows an isometric view of a prior art window assembly; [0016] FIG. 3 shows a fenestration cap according to one embodiment of the present invention; [0017] FIG. 4 shows a fenestration cap having a built in plaster key and a channel in the interior side according to another embodiment of the present invention; [0018] FIG. 5 shows a recessed fenestration cap having a built in plaster key and a flush interior side according to one embodiment of the present invention; [0019] FIG. 6 shows a recessed fenestration cap having a channel in the interior side according to one embodiment of the present invention; [0020] FIG. 7 shows a recessed fenestration cap having a flush interior side according to one embodiment of the present invention; [0021] FIG. 8 shows a fenestration cap having a built in plaster key which is attached to a window pane using a caulked butt joint; [0022] FIG. 9 shows a recessed fenestration cap having a built in plaster key which is attached a window pane using a caulked butt joint; [0023] FIG. 10 shows a sill detail of a fenestration cap anchored to a concrete slab; [0024] FIG. 11 shows a fenestration cap according to an alternative embodiment of the present invention; and [0025] FIG. 12 shows a head detail of a fenestration cap anchored to a concrete slab. [0026] Before any embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangements of components set forth in the following description, or illustrated in the drawings. The invention is capable of alternative embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the terminology used herein is for the purpose of illustrative description and should not be regarded as limiting. DETAILED DESCRIPTION OF THE INVENTION [0027] The present fenestration cap was designed to systematically coordinate and weatherproof fenestration openings before the installation of commercial or residential windows or doors. In one embodiment, the fenestration cap is a permanent fixtures in the building in which it is installed. The present cap allows for plastering and installation of interior drywall to be completed after installation of the fenestration cap itself, all of which may be completed at the leisure of a general contractor before delivery of the windows and associated frames is even taken. As such, a delay in such delivery will not unnecessarily inconvenience the contractor and delay the job; plasterers and finishing crews no longer need to wait for the delivery of windows to a job site to complete their portions of the build. [0028] Once the windows and frames do arrive, they can be installed separately by attachment to the fenestration cap with sheet metal screws or other appropriate fastening means. Furthermore, if the window panes themselves ever need to be replaced, the frames in which they are mounted can be easily detached from the fenestration cap without the need to remove the cap itself. Formerly, the unitary frame in which windows were mounted and which was attached directly to the window opening necessitated a complete tear-out of the window opening to replace the window itself. As such, windows and doors are made independent and easily replaceable building components rather than permanent parts of the building structure. [0029] FIG. 1 is a side view of a prior art commercial window assembly showing a nail on concrete slab detail. A sill can 150 is attached directly to a concrete slab 101 using a fastener 102 . A pair of caulk beads 152 are also shown at the periphery of the interface between the sill can 150 and the concrete slab 101 . A sealant 106 is used to waterproof the intersection of the fastener 102 and the sill can 150 . A shim 107 may be used to position the sill can 150 on the concrete slab 101 . Also, backer rods 108 may be used to provide a stop for the application of the caulk bead 152 . [0030] Such an arrangement is known by those skilled in the art to be prone to leakage. The sill can 150 , together with a sill can filler 155 and a sill can stop 160 forms a frame assembly which secures a window 170 . One or more top load gaskets 171 as well as a setting block 172 may also be used with this assembly to further secure, cushion and waterproof the window 170 . [0031] With the embodiment shown, finish work on the window opening may only be completed once the window 170 and frame arrives. As such, the scheduling problems discussed above are common with this prior art embodiment. Furthermore, if the window 170 and frame needed to be changed, any plastering and drywall used to finish the window opening would have to be removed at that time. [0032] FIG. 2 shows an isometric view of a prior art window assembly of a similar type to that shown in profile in FIG. 1 . Here, a vertical sill can 250 forms an assembly together with a sill can filler 255 and a sill can stop 260 to receive a window. The vertical sill can 250 is sealed to a jamb 201 using a caulk bead 25 . The vertical sill can 250 is shown at right angles to a horizontal sill can 250 which is secured to its mounting platform using a fastener 202 . [0033] FIG. 3 shows a fenestration cap 300 according to a simplified embodiment of the present invention. Alternative fenestration caps are discussed in greater detail with reference to the following figures. Here, a fenestration cap 300 is shown having a vertical flashing 312 , a drywall channel 345 and a plaster key 346 , in addition to one or more screw races 305 . The dry wall channel is defined between a mounting flange 305 and a top side 305 b. The fenestration cap 300 is an independent piece separate from any sill can or window frame assembly which may be independently installed from the window to act as a terminal point for plaster and drywall installation as well as other finish work. [0034] FIG. 4 shows one embodiment of a fenestration cap 400 according to the present invention. The cap shown in FIG. 4 is being used in a window opening framed by wood framing members 435 and faced on the exterior side by plywood sheeting 437 . FIG. 4 shows a sill can 450 supporting a window 470 . As is known to one skilled in the art, a head can of a like, though not necessarily identical design, may be used to support the top edge of the window 470 in a storefront. Similarly, the fenestration cap 400 may be used to finish the top of the window opening rather than the bottom as is shown in FIG. 4 so as to provide a platform for attachment of the head can. [0035] As discussed above, finishing crews are responsible for the installation of the plaster 436 and drywall sheeting 438 , but these elements cannot be installed until a terminal point is provided for them to be finished against. In the prior art, this terminal point was provided by the sill can or frame of the window itself. However, this caused the previously mentioned problems of delays in construction while the finishing crews waited for the window and associated sill can and frame to be delivered. [0036] In the embodiment shown in FIG. 4 , a fenestration cap 400 is provided as a single piece separate from any sill can or window frame; as such it may be independently installed and acts as a terminal point for plaster and drywall installation. To this end, the fenestration cap 400 includes a plaster key 446 on its exterior side. The front edge of the plaster key 446 is designed to act as a guide for the tradesperson applying the plaster 436 ; a trowel may easily be drawn along this edge of the plaster key 446 to quickly and neatly apply an even layer of plaster to the assembly. In one embodiment, the plaster 436 is applied to a depth of ⅞″. As mentioned above, because the fenestration cap 400 is provided as a single separate piece, plaster may be applied to the plaster key 446 prior to the installation of the window or frame, avoiding the risk of damage to these elements. [0037] Similarly, in the shown exemplary embodiment, the fenestration cap 400 includes a base 415 , a top side 417 generally parallel to the base, as well as a first support 419 and a second support 421 between the base and the top side. The key 446 has at least a portion that extends perpendicularly from a side 411 defining a flashing 412 , and along the same plane as the top side 471 . The exemplary embodiment fenestration cap also includes a drywall channel 445 provided as a guide to receive a piece of drywall sheeting 438 such as standard ⅝″ sheetrock. This channel aids an unskilled laborer in the installation of interior drywall, plaster or paneling. The built in receiving and self-aligning channel creates a level fit for the installation of interior finish materials. Accordingly, the sheeting running from a corner bead 439 to the fenestration cap 400 can be quickly and accurately installed in a level position without the time consuming process of shimming or manual adjustment of the sheeting necessary with prior art systems. [0038] In the embodiment of the present invention shown in FIG. 4 , inserting the drywall sheeting 438 into the drywall channel 445 is all that is necessary to present a finished appearance for the inside of the window assembly. It is not necessary to tape or spackle the exposed joint between the drywall sheeting 438 and the fenestration cap 400 which lies below the water dam 411 . Thus, further time and expense is saved in the installation process. The drywall channel 445 may include one or more vertical fins 417 therein, which aid in gripping the portion of drywall sheeting 438 inserted into the drywall channel 445 . These fins also provide a cushioning effect for the drywall sheeting 438 during seismic activity. [0039] In one embodiment of the present invention, the fenestration cap 400 is installed in the window opening using one or more wood screws 430 through the vertical flashing 412 and a mounting flange 415 to secure the fenestration cap 400 to the underlying structure of the window opening, namely the wood framing members 435 and/or the plywood sheeting 437 . A vertical flashing 412 may be provided allowing the fenestration cap 400 to be attached to the plywood sheeting 437 . A self healing membrane 434 may be placed between the vertical flashing 412 and the plywood sheeting 437 to provide further waterproofing for the underlying structure of the window opening. The self healing membrane 434 may be in one embodiment a continuous waterproof self healing rubberized membrane is manufactured from polypropylene. The vertical flashing 412 also provides additional waterproofing to the finished window assembly by providing a water barrier to any water which infiltrates behind the plaster 436 . The fenestration cap 400 may be attached by its interior side with one or more additional wood screws 430 to the wood framing members 435 . [0040] An expansion cavity 433 may be provided between the fenestration cap 400 and the wood framing members 435 which may contain a foam strip, 3/16″ thick in one exemplary embodiment to act as a shock absorber in the event of thermal or other expansion of the underlying members or seismic movement. [0041] It will be understood by one skilled in the art that the inventive concepts of the invention described herein are not limited to a fenestration cap for use only with the specific materials discussed above, such as plaster and drywall for instance. In lieu of plaster for example, a variety of siding materials can be used to finished the exterior of the storefront assembly shown in FIG. 4 . Likewise, plaster or paneling or a variety of other interior finishing materials may be used instead of the drywall sheeting 438 discussed above. [0042] The fenestration cap 400 shown in FIG. 4 can be made from aluminum, vinyl, steel, plastic and other appropriate materials known to those skilled in the art. In one exemplary embodiment, the fenestration cap may be manufactured as an extruded aluminum piece in twenty-four foot lengths. This exceeds the length of typical extruded pieces used in window openings such as j-molds, for which the industry standard length is ten feet. Accordingly, with this embodiment of the present invention, the need for making time consuming splices between the lengths is reduced. [0043] Furthermore, the width of the fenestration cap may be designed in various widths to fit various windows and window openings. The present invention is designed to work with window systems from multiple companies. As is known to one skilled in the art, the width of a commercial window is customarily measured with reference to its mullion width. These widths come in standard sizes including 2, 3, 4, 4.5 and 6 inches in width, among others. It is envisioned that a fenestration cap may be designed to match each of these standard window widths, although one skilled in the art will understand that a fenestration cap according to the present invention can be made to match any width window. FIG. 4 shows a window 4.5 inches in width, and the fenestration cap 400 shown therein has been designed to match a window of this width. [0044] The fenestration cap 400 may be assembled in the contractor's shop or on the job site itself into a custom system for any size window opening by cutting stock lengths of the fenestration cap 400 at forty-five degree angles (or any other set of complementary angles). These lengths can then be attached to each other using fasteners passing through the integral screw races 405 of adjacent lengths of fenestration cap 400 . For an aluminum fenestration cap, stainless steel sheet metal screws can be used as fasteners. [0045] If the fenestration cap 400 is assembled in the contractor's shop and transported to the job site, a blank made of styrofoam or other material may be inserted into the center of the fenestration cap assembly to stiffen it for transport. This blank may be secured within the assembly using double-sided tape. Furthermore, after the fenestration cap is installed in the window opening, a blank secured within the fenestration cap 400 assembly using double sided tape may be also used to weatherproof the capped window opening in lieu of the window itself. Taped plastic sheeting may also be used for this purpose. In any event, fenestration cap assembly provides and easy base from which to tape or otherwise weatherproof a window opening prior to the installation of the window assembly. [0046] The sill can 450 shown in FIG. 4 is an industry standard sill can having a number of interlocking parts. A sill can filler 455 and a sill can stop 460 snap into place within the sill can 450 to lock a window 470 in position. The window 470 is firmly held by a pair of top load gaskets 471 , which may be neoprene gaskets. The sill can 450 is shown engaging window 470 through the pair of top load gaskets 471 and a setting block 472 . These top load gaskets 471 are held partially snapped into receiving tracks in the sill can filler 455 and the sill can stop 460 . These gaskets are also known to those skilled in the art as self-locking gaskets, given that the weight of the window 470 bears on these gaskets to create a seal between the gaskets 471 and the window 470 . [0047] In one embodiment of the present invention, at some point after the fenestration cap 400 itself has been installed in the window opening, the sill can 450 , having a window 470 therein, may be lifted onto the length of fenestration cap 400 shown in FIG. 4 . The sill can 450 can then be attached to the fenestration cap 400 using one or more sheet metal screws 451 . In an exemplary embodiment, the window 470 may be surrounded on multiple sides by either a sill can or frame which abuts a length of fenestration cap to which the sill can or frame may be attached. [0048] If the fenestration cap 400 is used with a frame such as the sill can 450 and related components shown in FIG. 4 , the point of attachment of the sill can 450 to the fenestration cap 400 must be made waterproof. Accordingly, before the sill can 450 is attached to the fenestration cap 400 using the sheet metal screws 451 , a caulk bead 452 is laid down therebetween to waterproof the joint. In one embodiment, the caulk used for the caulk bead 452 is structural grade silicone. At the portion of the joint nearest the exterior side of the storefront, a gap of set height 453 is provided which is designed to match the warranty requirements of the standard window sealants used in the industry. In the embodiment shown in FIG. 4 , this gap has a height of ⅜ inches. [0049] A water dam 411 may be provided at the interior side of the caulk bead 452 as a further moisture barrier in the event that water is able to infiltrate through to the interior side of the caulk bead 452 . The water dam 411 also provides a stop allowing for easy installation of the window and sill can 450 . Once the fenestration cap 400 is in place in a window opening, an unskilled laborer would easily be able to install the sill can 450 and related components to provide a finished storefront by lifting the window assembly up and into the opening within the fenestration cap assembly, placing the interior edge of the sill can 450 firmly against the water dam 411 . As such, no measuring is required for the installation of the window assembly itself when the fenestration cap 400 has been used to frame the window opening ahead of time. [0050] Furthermore, even if despite all the precautions built into the design of the fenestration cap 400 , water is able fully infiltrate the joint in the area of the caulk bead 452 and pass over the water dam 411 , the fenestration cap 400 fully spans the width of the window opening in which it is placed so that any water which does manage to flow over the fenestration cap 400 is directed over, rather than into, the wall on which the fenestration cap 400 rests. [0051] The fenestration cap 400 may be provided with a thermal break 410 to reduce the transfer of heat through the fenestration cap 400 to help meet energy efficiency building requirements such as California's Title 24 requirements. Accordingly, an insulation material is formed in a cavity of the fenestration cap 400 . This insulation material has sufficient strength such that after it is formed in the cavity, a portion of the fenestration cap 400 can be removed in the vicinity of the insulation such that the fenestration cap 400 becomes two thermally separate pieces joined only by the insulation. This helps to substantially thermally isolate the interior from the exterior of the finished storefront by preventing heat transmission through the fenestration cap 800 . [0052] The fenestration cap 400 has the additional advantage that over prior art systems in that it can span doorway openings in a storefront and need not be trimmed to the jamb of a doorway. With the addition of a separate threshold unit, the section fenestration cap 400 , spanning the bottom of a doorway, presents a finished appearance. Accordingly, a single length or series of lengths of the fenestration cap 400 can be made to span the base of an entire storefront serving as both a sill of a window and a door threshold. [0053] FIG. 5 shows a fenestration cap 500 for use with a frameless window system. While the fenestration cap 500 shares many of the same elements as the cap shown in FIG. 4 , the cap 500 is shown engaging the window 570 through a top load gasket 571 and a setting block 572 , rather than incorporating a separate sill can, as is the case in the cap of FIG. 4 . In one embodiment, the top load gasket 571 may be provided by a silicone glazed bead. [0054] As in the previous embodiment, the fenestration cap 500 is attached to the wood framing members 535 and plywood sheeting 537 using a series of wood screws 530 . The fenestration cap 500 is provided with a drywall channel 545 and plaster key 546 designed to receive drywall sheeting 538 and plaster 536 . A spacer 509 may be provided to support the drywall sheeting 538 in the area of a corner bead 539 . [0055] FIG. 6 shows a recessed fenestration cap having a channel in the interior side according to one embodiment of the present invention. In FIG. 6 , the top and front edges of the plaster key 647 and the top edge of the lip 649 are designed to act as guides to the tradesperson applying the plaster 436 to the assembly; a trowel may easily be drawn along these edges to quickly and neatly apply an even layer of plaster in the space between the plaster key 647 and the lip 649 . The surface created by plastering between the plaster key 647 and the lip 649 will not be completely horizontal however; the fenestration cap 600 is designed so that when level, the top edge of the plaster key 647 lies on a 2% decline from the horizontal with respect to the top edge of the lip 649 . This encourages water to shed off of the architectural reveal created by this plastered surface toward the exterior of the storefront. Furthermore, the fenestration cap 600 is provided with a serrated texture 648 to better anchor the plaster to the fenestration cap 600 . Also, the plaster key 647 is provided with holes drilled therein (not shown) so that the plaster applied below the plaster key 647 and the plaster applied to the side of the plaster key 647 is able to form one contiguous and stable mass, leading to increased durability. FIG. 6 also depicts one of two sheet metal screws 651 entering a cavity. In some embodiments of the present invention, one or more sheet metal screws is used to affix the sill can 650 to the fenestration cap. If water leaks under the sill can and above the fenestration cap, it could leak down through the sheet metal screw 651 hole. However, if the screw hole goes through a portion of the fenestration cap into the cavity, the cavity will serve as a reservoir to hold the water, preventing water from entering into the interior, and trapping water in the cavity until it evaporates. [0056] FIG. 7 shows a recessed fenestration cap 700 having a flush interior side according to one embodiment of the present invention. The fenestration cap 700 is attached to the wood framing members 735 and plywood sheeting 737 using a series of wood screws 730 . The fenestration cap 700 is attached to an assembly comprising a sill can 750 , sill can filler and 755 sill can stop 760 using sheet metal screws 751 and a caulk bead 752 . This assembly is shown engaging the window 770 through a top load gasket 771 and a setting block 772 . In contrast to FIGS. 4 , 5 and 6 however, the fenestration cap 700 is not provided with a drywall channel designed to receive drywall sheeting. Instead, the fenestration cap 700 is designed as a relatively flush assembly which may be placed over a corner bead 739 applied to finish the joint between the drywall sheeting 738 and the wood framing members 735 . [0057] FIG. 8 shows a fenestration cap 800 attached to a window 870 using a butt joint 895 . The arrangement shown in FIG. 8 is a counterpart to the fenestration cap 500 of FIG. 5 for use with a frameless window system. While the fenestration cap 500 supports the sill of a window in a frameless window system, the fenestration cap 800 may be applied to the jamb of such a window opening to support the sides of the window 870 . [0058] As in the previous figures, the fenestration cap 800 is provided with a plaster key 846 to facilitate the easy application of the plaster 836 , and a drywall channel 845 to facilitate the installation of the drywall sheeting 838 . The fenestration cap 800 is secured to the wood framing members 835 and the plywood sheeting 837 using one or more wood screws 830 . Furthermore, the fenestration cap 800 is provided with a thermal break 810 , which may be supplemented with the creation of a saw cut 896 in the fenestration cap 800 to substantially thermally isolate the interior from the exterior of the finished storefront, preventing heat transmission through the fenestration cap 800 . [0059] FIG. 9 shows a recessed fenestration cap 900 having a built in plaster key 947 which is attached a window pane using a caulked butt joint. The fenestration cap 900 is similar to the fenestration cap 800 of FIG. 8 in that it may be applied to the jamb of a window opening in a frameless window system to support the window therein. However, it differs in that it features a set back similar to that used in the fenestration cap 600 of FIG. 6 , wherein the top and front edges of the plaster key 947 and the top edge of the lip 949 are designed to act as guides to the tradesperson applying the plaster 936 to the assembly. [0060] As in FIG. 6 , the surface created by plastering between the plaster key 947 and the lip 949 will not be completely horizontal. The fenestration cap 900 is designed so that when level, the top edge of the plaster key 947 lies on a slight decline from the horizontal with respect to the top edge of the lip 949 . This encourages water to shed off of this architectural reveal toward the exterior of the storefront. The fenestration cap 900 is also provided with a serrated texture 948 to better anchor the plaster 936 to the fenestration cap 900 . [0061] FIG. 10 is an alternative embodiment of the present invention wherein a sill detail a fenestration cap 1000 shown is anchored to a concrete slab 1001 using a fastener 1002 . The concrete slab 1001 may be part of an overhanging eve. In place on the fenestration cap 1000 are a sill can 1050 , a sill can filler 1055 , and a sill can stop 1060 which, though the top load gaskets 1071 secure the window 1070 . [0062] The gap between the sill can 1050 and the fenestration cap 1000 is sealed with a caulk bead 1052 . As in other embodiments, a gap of set height 1053 is provided as part of the caulk bead 1052 to match industry standard warranty requirements. A water dam 1011 is provided at the interior side of the caulk bead 1052 as a moisture barrier in the event that water is able to infiltrate through to the interior side of the caulk bead 1052 , and to provide a stop for easy installation of the sill can 1050 . [0063] The embodiment of FIG. 10 additionally shows that the fenestration cap 1000 is slightly wedge shaped; having a narrower edge on the exterior side. As such, water will be more inclined to run to the outside of the window 1070 both if it infiltrates between the fenestration cap 1000 and the sill can 1050 , and if it gets into the sill can 1050 itself. In prior art models, if water infiltrated the sill can 1050 for example by flowing between it and the sill can filler 1055 , it would pool within the sill can. Weep holes were sometimes added in the sill can 1050 to aid in drainage, but cannot prevent pooling in the event of an unfavorable alignment of the sill can 1050 itself. [0064] FIG. 11 shows a fenestration cap 1100 according to an alternative frameless embodiment of the present invention wherein the window 1170 is mounted directly on the fenestration cap 1100 using a caulk joint 1195 . As is the previous figures, the fenestration cap 1100 is provided with a plaster key 1146 to facilitate the easy application of the plaster 1136 , and a drywall channel 1145 to facilitate the installation of the drywall sheeting 1138 . The fenestration cap 1100 is secured to the wood framing members 1135 and the plywood sheeting 1137 using one or more wood screws 1130 . [0065] FIG. 12 shows a head detail of a fenestration cap 1200 anchored to an overhang 1201 . The fenestration cap 1200 is of a type which can be attached on a continuous eve or overhang 1201 without need of a flange. In the embodiment shown, the fenestration cap 1200 is attached using the fastener 1202 . On the fenestration cap 1200 is mounted an assembly comprising a sill can 1250 , sill can filler 1255 and sill can stop 1260 . This assembly may be mounted using sheet metal screws 1251 , and seamed using a caulk bead 1252 . A window 1270 may be mounted in this assembly using top load gaskets 1271 . The fenestration cap 1200 may be installed before the sill can 1250 to allow for the completion of work involving the plaster 1236 and drywall sheeting 1238 , the latter of which fits easily into the drywall channel 1245 . [0066] The preceding description has been presented with reference to some embodiments of the invention. Workers skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structure may be practiced without meaningful departing from the principal, spirit and scope of this invention. Accordingly, the foregoing description should not be read as pertaining only to the precise structures and methods described and illustrated in the accompanying drawings, but rather should be read consistent with and as support to the following claims which are to have their fullest and fair scope. For instance, FIG. 10 depicts a fenestration cap that is slightly wedge shaped, and thus parts of the fenestration cap may not be perfectly parallel or perfectly perpendicular in reference to one another. Therefore, as used herein, parallel and perpendicular could mean substantially parallel and substantially perpendicular.

In an exemplary embodiment, a window sill comprises a structural base having a first side and a second side, a fenestration cap attached to the structural base, a window frame mounted on the fenestration cap and finish elements applied to the structural base and adjacent to the fenestration cap. The window frame may be removed from the fenestration cap without disturbing the finish elements. Alternatively, a method of installing a window in a window opening comprises providing a window opening and preparing the window opening for receiving a fenestration cap, installing a fenestration cap by placement within and attachment to the window opening in a primary step, and installing a window within the window opening by placement within and attachment to the fenestration cap in a secondary step.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims foreign priority benefits under 35 U.S.C. §119(a)-(d) to German patent application number DE 102009020892.5, filed May 13, 2009, which is hereby incorporated by reference in its entirety. TECHNICAL FIELD [0002] The present invention relates to a method for closing containers, as well as to a packaging machine for carrying out such a method. BACKGROUND [0003] Packaging machines for closing already preformed and separated containers are known in the form of so-called tray sealers, for example from DE 10 2006 018 327 A1. Such machines are fed with already preformed and separated trays which are usually stacked and stocked after they have been formed. The containers are individually removed from the stock and placed onto a conveying belt where they are filled with a product from above. In the conventional tray sealer, a sealing foil is subsequently applied onto the trays that are open to the top which closes as well as seals the trays. [0004] In conventional tray sealers, the sealing foil must not be stretched by the product, as otherwise the sealing foil might tear off. Consequently, the trays must be comparably deep to prevent the products from projecting over the edge of the trays. This excessive height of the trays, however, also involves drawbacks. On the one hand, this leads to an increase in the required amount of material and costs of a package. On the other hand, less preformed or filled trays can be accommodated per volume, so that costs increase for the stock-keeping of the empty trays as well as for the distribution of the filled and closed trays. SUMMARY [0005] It is an object of the present disclosure to overcome these drawbacks with structural means that are as simple as possible. [0006] An embodiment of the present disclosure involves using a deep-drawable foil for closing already preformed and separated containers, and the foil is deep-drawn in a forming means or device of a packaging machine before the containers are closed with the lid foil. This deep-drawing offers the advantage that the package can be much better adapted to the respective product than before, although the containers are already preformed. In particular, products projecting over the container edge can also be accommodated in the containers, without the lid foil stretching over the product. Moreover, there are also esthetic advantages as, in contrast to conventional tray sealers, the upper side of each package does no longer have to be flat, but can be structured. [0007] The lid foil may be heated upstream of and/or in the forming device to permit deep-drawing. The preheating of the lid foil upstream of the forming device can accelerate deep-drawing and reduce superfluous waiting times of other components of the packaging machine. [0008] It is conceivable to deep-draw the lid foil towards the side of the lid foil facing the container during closing altogether or at least in sections. In this manner, a lid section which projects into the interior of the container is formed in the lid foil. This is in particular suited for products or regions of a product which are situated at a lower level than the edge of the container. [0009] As an alternative or in addition, it is conceivable to deep-draw the lid foil towards the side of the lid foil facing away from the container during closing altogether or at least in sections. In this manner, a dome shaped lid section is formed which projects upwards over the container edge and permits the accommodation of projecting products without the lid foil stretching over the product. [0010] By the method according to the present disclosure, in the deep-drawing process, at least one concave and/or one convex section can be formed on the side of the lid foil facing the container during closing. They can facilitate the placement of complementary formed regions of the products against the lid to prevent, for example, shifting of the products in the containers. [0011] The forming device can be provided separately from the closing station. The complete packaging machine, however, becomes more compact and the method thereby less complex, if deep-drawing is carried out within the closing station itself. [0012] As lid foil, a flexible foil or a hard foil could be used, if they can be deep-drawn in a suited manner. [0013] Depending on the product, it can be advantageous to use a multilayer foil as lid foil. For example, a combination of an outer layer impermeable to oxygen and an inner layer permeable to oxygen would be conceivable to permit oxygen to flow around the products. [0014] In one variant of the invention, the lid foil or the lid section formed in it, respectively, is only placed onto the respective containers by a form fit in the form of a “slip lid”. The lid section can, for example, snap in at an edge of the container to securely connect the lid to the container. [0015] In addition or as an alternative, it is possible for the lid foil to be sealed onto the containers, in particular if the interior of the container is to be hermetically sealed. [0016] If the lid foil is sealed to the containers, the transport of the closed containers connected with the lid foil out of the closing station can cause further lid foil to be drawn behind, which is used for closing following containers. In this manner, one could do without a separate conveyor device for the lid foil. [0017] The present disclosure also relates to a packaging machine for carrying out a method according to the present disclosure. The packaging machine comprises a forming means or device for deep-drawing the deep-drawable lid foil. [0018] It is appropriate for the forming device to comprise an exchangeable insert which determines the deformation of the lid foil to a lid section. This insert can be replaced if it is worn down, or if a different shape of the lids for the containers is to be produced. [0019] Mainly in comparably thick hard foils, the pulling force acting on the lid foil only by the movement of the closed containers still connected to the lid foil might not be sufficient. In this case, it is advantageous to provide, in addition to a transport means for the containers, such as a conveyor belt or any other suitable transport device, a separate conveying means for the lid foil, for example a clamp chain arranged on both sides which can also be used to stretch the lid foil laterally, or any other suitable conveyor device. [0020] The packaging machine according to the present disclosure may have a tool for placing and/or sealing the lid foil onto the containers. In this tool, the actual closing of the containers is thus accomplished. [0021] The tool itself can comprise a lower tool and an upper tool which can be moved relative to each other. For example, they can open for receiving the unclosed containers and reduce the space between them for closing and possibly evacuating and/or gassing the containers. [0022] It is appropriate if the lower tool and the upper tool can be spaced apart by the relative movement at least far enough to correspond to the sum of the height of a container and the height of a lid section of the lid foil. In this manner, the closing tool also permits the accommodation of containers in which the product and the lid project over the edge of the container. [0023] In the following, two advantageous embodiments of the present disclosure are illustrated more in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0024] FIG. 1 is a perspective view of a packaging machine according to the present disclosure; [0025] FIGS. 2 to 8 show schematic vertical sections through a first embodiment of the packaging machine in different steps of a method according to the present disclosure; and [0026] FIGS. 9 to 15 show a second embodiment of the packaging machine in different steps of the method according to the present disclosure. DETAILED DESCRIPTION [0027] In the Figures, equal and similar components are provided with the same reference numerals. [0028] FIG. 1 shows a first embodiment of a packaging machine 1 according to the invention in a perspective view. This embodiment is a tray sealer. The packaging machine 1 has a machine frame 2 on which a closing station 3 is arranged for closing as well as possibly evacuating, gassing and/or sealing supplied, tray-shaped containers as well as for cutting a lid foil used for closing. The closing station 3 is located under a cover 4 that can be opened. [0029] The packaging machine 1 furthermore has a feed belt 5 for feeding the containers, a discharge belt 6 for carrying away the closed containers, a foil feed roller 7 for taking up and feeding a roll of a lid foil, a foil stretching means 8 for stretching the lid foil, as well as a foil residue winder 9 for winding up the foil residues that remain after sealing. A display 10 permits the operator of the packaging machine 1 to check and control the operation of the packaging machine 1 . To this end, operational controls 11 can be provided at the display 10 , for example operator panels or switches to influence the operation of the packaging machine 1 . [0030] FIG. 2 shows, in a first embodiment of the packaging machine 1 according to the invention, a vertical section through the closing station 3 in a schematic view. The closing station 3 has a tool 12 which in turn comprises an upper tool 13 and a lower tool 14 . The upper tool 13 and the lower tool 14 can be moved in the vertical direction relative to each other. The upper and lower tools 13 , 14 can form a closed chamber 15 between themselves in a closed state (see FIG. 3 ). [0031] A lifting table 16 is provided at the lower tool 14 which can be traveled in the vertical direction via a lifting rod 17 independent of the lower tool 14 . The lifting table 16 forms a recess or cavity 18 for receiving a prefabricated, tray-shaped container 19 . This container 19 can consist, for example, of hard plastics. After preforming, a plurality of containers 19 are stacked and stocked in this manner. They can be individually removed from this stock and placed onto the feed belt 5 of the packaging machine 1 to be filled there. [0032] One can see in FIG. 2 that an edge 20 of the container rests on an edge of the lifting table 16 or cavity 18 . One can also see that the container 19 is filled with a product 21 which projects upwards beyond the level formed by the edge 20 of the container 19 . [0033] In the present embodiment, the upper tool 13 has a more complex design. It has on its part three tool components which can be traveled relatively to each other in the vertical direction within the upper tool 13 independent of each other as well as independent of the outer wall 22 of the upper tool 13 . The innermost tool component is a forming means 23 for forming a lid section in the single- or multilayer lid foil 24 advance by the foil feed roller 7 . In the present embodiment, the forming means 23 may comprise any suitable forming device, such as a forming mold or tool having a concave design on a surface 25 facing the container 19 . The forming means 23 can have vacuum lines (not shown) to create a vacuum between the surface 25 and the lid foil 24 . [0034] Above the forming means 23 , a sealing plate 26 is arranged which has sealing edges 27 projecting downwards. The sealing edges 27 are shaped such that they can contact the edge 20 of the container 19 when the sealing plate 26 is lowered. [0035] A cutting means 28 is provided above the sealing plate 26 , between the sealing plate 26 and the outer wall 22 of the upper tool 13 . The cutting means 28 may comprise any suitable cutting device, such as a movable cutting tool having cutting edges 29 projecting downwards which are configured for cutting the lid foil 24 in two. The tool 12 can moreover have means for evacuating and/or gassing the chamber 15 formed between the upper and the lower tool 13 , 14 . For example, the tool 12 may be connected to a vacuum pump, or any other suitable evacuating device, and/or a gas supply system. [0036] The deep-drawable (e.g., thermoplastic) lid foil 24 passes over a first deflection roller 30 and is there deflected such that it traverses the interior of the tool 12 essentially in parallel to the level formed by the edge 20 of the container 19 . The residual sections of the lid foil 24 remaining after the containers 19 have been closed and the lid sections punched out pass over a second deflection roller 31 to a residual foil winder 9 to be accumulated there. Between the foil feed roller 7 and the tool 12 , a foil stretching means 8 , which is not represented in FIG. 2 for a better overview, can be moreover provided. The foil stretching means 8 may be any suitable device, such as a movable plate or a system of rotatable drums or cylinders that includes one or more cylinders that are movable toward and away from another cylinder. [0037] Between the foil feed roller 7 and the first deflection roller 30 , a heating means or a preheating means 32 (if a further heating step is performed), respectively, is moreover provided. The heating means 32 can be a heating plate which is heated, for example, via a thermal fluid or an electric heating medium. The heating means 32 is used to heat a given section 33 of the lid foil 24 to a temperature which permits thermoplastic forming of the lid foil 24 during a deep-drawing operation. [0038] With reference to FIGS. 2 to 8 , a method according to the present disclosure and the operating sequence of the packaging machine 1 , respectively, will now be illustrated. [0039] FIG. 2 shows the tool 12 of the packaging machine 1 in a state in which a tray 19 filled with a product 21 has been inserted into the cavity 18 of the lifting table 16 and guided into the interior of the tool 12 . For this purpose, the upper and the lower tools 13 , 14 can be removed from each other to such an extent that the distance A between the lower edge of the upper tool 13 and the upper edge of the lower tool 14 is larger than the sum of the height of the container 19 and the projecting part of the product 21 , to permit in this manner the introduction of the filled container 19 into the tool 12 . A certain section 33 of the lid foil 24 is heated under the heating means 32 . [0040] FIG. 3 shows the tool 12 in a state in which first the lid foil 24 has been conveyed far enough for the heated section 33 to be located underneath the forming means 23 . At this time, the feed of the lid foil 24 is stopped. One can see in FIG. 3 that the upper tool 13 and the lower tool 14 move towards each other until they clamp the lid foil 24 between their edges and form a closed chamber 15 between themselves. As the feed of the lid foil 24 is stopped, now a further section 33 ′ of the lid foil can be brought to the temperature required for forming under or in the heating means 32 . [0041] It could already be seen in FIG. 3 that the forming means 23 contacts the lid foil 24 when the upper tool 13 is lowered. Arrows 34 in FIG. 4 indicate that now a vacuum is created at the surface 25 of the forming means 23 by suited provisions. In connection with the contact between the forming means 23 and the lid foil 24 , this vacuum takes care that the heated section 33 of the lid foil 24 is pulled against the concave surface 25 of the forming means 23 and in this manner deep-drawn to form a lid section 35 . [0042] The lid section 35 is represented in FIG. 5 . It has a shape which is complementary to the edge 20 of the container 19 on the outer surface. On the side facing the product 21 , the lid section 35 is concave. [0043] FIG. 6 shows the tool 12 in a state in which—starting from the state in FIG. 5 —the lifting table 16 was lifted until the edge 20 of the container 19 came into contact with the lid foil 24 . This movement of the lifting table 16 is indicated by arrow 36 . Simultaneously—as indicated by arrow 37 —the sealing plate 26 was lowered until its sealing edges 27 came into contact with the lid foil 24 from above. In this state, the lid foil 24 is now sealed onto the edge 20 of the container 19 . [0044] Subsequently or simultaneously with the sealing, the cutting means 28 is lowered—as shown in FIG. 7 —, so that its cutting edges 29 cut out the lid foil 24 all around the closed container 19 . This movement of the cutting means 28 is indicated by arrow 38 . [0045] In FIG. 8 , the tool 12 is opened. This is done by moving the lower tool 14 and the lifting table 16 downwards and the upper tool 13 with the forming means 23 , the sealing plate 26 and the cutting means 28 upwards. The lid section 35 is firmly connected to the rest of the container 19 by the sealing and remains at the container 19 . The filled container 19 can now be removed from the tool 12 . At the same time, the lid foil 24 can be transported forwards, while the rest of the lid foil 24 that remains during cutting is winding up on the foil residue winder 9 . The closing process can now be performed in the same manner for a subsequent container. [0046] FIG. 9 shows a second embodiment of a packaging machine 1 according to the present disclosure. It differs from the first embodiment in that the forming means 23 for forming the lid sections is now no longer provided in the closing tool 12 , but in the region of the heating means 32 . Apart from that, the upper tool 13 and the lower tool 14 of the closing tool 12 remain unchanged. In particular, the upper tool 13 still comprises a sealing plate 26 and a cutting means 28 , while the lower tool 14 still comprises a lifting table 16 . [0047] In the second embodiment, the forming means 23 comprises a first forming half 39 and a second forming half 40 . As indicated by the arrows 41 , the two forming halves 39 , 40 can be moved relative to each other perpendicular to the plane of the lid foil 24 , so that they can close around the lid foil 24 or can release the lid foil 24 , respectively. [0048] In the first forming half 39 , an exchangeable inset 42 is provided. Its surface 43 facing the lid foil 24 defines the shape of the lid section 35 if the section of the lid foil 24 heated by the heating means 32 in the opposite second forming half 40 is pulled closer by applying a vacuum to the surface 43 of the inset 42 to deep-draw the lid foil 24 . [0049] FIGS. 9 to 15 show various steps of the method according to the present disclosure during the operation of the packaging machine 1 according to the second embodiment. FIG. 9 shows the packaging machine 1 in a state in which a fresh section of the lid foil 24 has been brought into the forming means 23 . [0050] In FIG. 10 , the two forming halves 39 , 40 of the forming means 23 have been closed. Arrows 44 indicate that a vacuum is created at the inset 42 of the forming means to place the lid foil 24 in this region against the inset 42 of the first forming half 39 and to form a lid section 35 in this manner. The inset 42 can be exchanged if lid sections 35 having a different shape are to be produced. [0051] FIG. 11 shows the state of the packaging machine 1 after the lid foil 24 has been deep-drawn in the forming means 23 . The lid foil 24 now has a lid section 35 . [0052] In FIG. 12 , the two forming halves 39 , 40 have been removed from each other. The opening 45 formed between them now must be large enough—at least in the exiting direction out of the forming means 23 —to let the domed lid section 35 pass. [0053] Between the state in FIG. 12 and the state in FIG. 13 , the lid foil 24 has been moved into the conveying direction 45 far enough for the lid section 35 now to be positioned within the closing tool 12 over the container 19 to be closed. The first deflection roller 30 here only lies against an outer edge of the lid foil 24 , so that it does not collide with the lid section 35 in the central region of the lid foil 24 . [0054] FIG. 14 shows the packaging machine 1 in a state in which the closing tool 12 has been closed by moving the upper tool 13 and the lower tool 14 towards each other. A contact between the sealing edges 27 of the sealing plate 26 and the edge 20 of the container 19 , that is close by due to the lifting of the lifting table 16 , permits to seal the lid foil 24 to the container 19 . Simultaneously or subsequently, the cutting means 28 has been lowered to cut out the closed container. The forming means 23 has simultaneously closed around a new section of the lid foil 24 to form a further lid section 35 . [0055] In FIG. 15 , the forming means 23 as well as the closing tool 12 have been opened. The closed container 19 can now be removed from the tool 12 , and the cycle can start anew. [0056] Starting from the two embodiments described in detail, a method according to the present disclosure and a packaging machine according to the present disclosure can be modified in many ways. It is, for example, conceivable for the lid sections 35 not to be sealed to the edge 20 of the container 19 , but to only be placed onto the container 19 by a form fit in the form of slip lids. It is moreover possible to impart any arbitrary shape to the lid section 35 . In the first embodiment, too, the forming means 23 can have an exchangeable inset 42 . Though it is not shown, several lid sections 35 can be manufactured one after or one next to the other in the forming means 23 , and several containers 19 can be simultaneously closed in the closing station 3 . [0057] While exemplary embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.

The invention relates to a method for closing already preformed and separated containers ( 19 ), for example trays, with a lid foil ( 24 ) in a closing station ( 3 ). The invention is characterized in that a deep-drawable foil is used as lid foil ( 24 ), that the lid foil ( 24 ) is deep-drawn in a forming means ( 23 ) of the packaging machine ( 1 ), and that the deep-drawing of the lid foil ( 24 ) is accomplished before the containers ( 19 ) are closed with the lid foil ( 24 ). The invention also relates to a packaging machine ( 1 ) suited for carrying out such a method.

RELATED APPLICATIONS [0001] This application is a Continuation of and claims priority to U.S. application Ser. No. 13/592,202, filed on Aug. 22, 2012, which is a Continuation of and claims priority to U.S. application Ser. No. 13/013,680, filed on Jan. 25, 2011, which is a Continuation of and claims priority to U.S. application Ser. No. 12/704,097, filed on Feb. 11, 2010 and issued on Feb. 22, 2011 as U.S. Pat. No. 7,895,059, which is a Continuation of and claims priority to U.S. application Ser. No. 10/322,348, filed on Dec. 17, 2002 and issued on Feb. 23, 2010 as U.S. Pat. No. 7,668,730, which applications are herein incorporated by reference in their entirety. FIELD OF THE INVENTION [0002] The present invention relates to distribution of drugs, and in particular to the distribution of sensitive drugs. BACKGROUND OF THE INVENTION [0003] Sensitive drugs are controlled to minimize risk and ensure that they are not abused, or cause adverse reactions. Such sensitive drugs are approved for specific uses by the Food and Drug Administration, and must be prescribed by a licensed physician in order to be purchased by consumers. Some drugs, such as cocaine and other common street drugs are the object of abuse and illegal schemes to distribute for profit. Some schemes include Dr. shopping, diversion, and pharmacy thefts. A locked cabinet or safe is a requirement for distribution of some drugs. [0004] Certain agents, such as gamma hydroxy buterate (GHB) are also abused, yet also are effective for therapeutic purposes such as treatment of daytime cataplexy in patients with narcolepsy. Some patients however, will obtain prescriptions from multiple doctors, and have them filled at different pharmacies. Still further, an unscrupulous physician may actually write multiple prescriptions for a patient, or multiple patients, who use cash to pay for the drugs. These patients will then sell the drug to dealers or others for profit. [0005] There is a need for a distribution system and method that directly addresses these abuses. There is a further need for such a system and method that provides education and limits the potential for such abuse. SUMMARY OF THE INVENTION [0006] A drug distribution system and method utilizes a central pharmacy and database to track all prescriptions for a sensitive drug. Information is kept in a central database regarding all physicians allowed to prescribe the sensitive drug, and all patients receiving the drug. Abuses are identified by monitoring data in the database for prescription patterns by physicians and prescriptions obtained by patients. Further verification is made that the physician is eligible to prescribe the drug by consulting a separate database for a valid DEA license, and optionally state medical boards to determine whether any corrective or approved disciplinary actions relating to controlled substances have been brought against the physician. Multiple controls beyond those for traditional drugs are imposed on the distribution depending on the sensitivity of the drug. [0007] Education is provided to both physician and patient. Prior to shipping the drug for the first time, the patient is contacted to ensure that product and abuse related educational materials have been received and/or read. The patient may provide the name of a designee to the central pharmacy who is authorized to accept shipment of the drug. Receipt of the initial drug shipment is confirmed by contacting the patient. Either a phone call or other communication to the patient within a set time after delivery may be made to ensure receipt. Further, a courier service's tracking system is used to confirm delivery in further embodiments. If a shipment is lost, an investigation is launched to find it. [0008] In one embodiment, the drug may be shipped by the central pharmacy to another pharmacy for patient pick-up. The second pharmacy's ability to protect against diversion before shipping the drug must be confirmed. This ability may be checked through NTIS and State Boards of Pharmacy. [0009] Prescription refills are permitted in the number specified in the original prescription. In addition, if a prescription refill is requested by the patient prior to the anticipated due date, such refills will be questioned. A lost, stolen, destroyed or spilled prescription/supply is documented and replaced to the extent necessary to honor the prescription, and will also cause a review or full investigation. [0010] The exclusive central database contains all relevant data related to distribution of the drug and process of distributing it, including patient, physician and prescription information. Several queries and reports are run against the database to provide information which might reveal potential abuse of the sensitive drug, such as early refills. BRIEF DESCRIPTION OF THE DRAWINGS [0011] FIG. 1 is a block diagram of a computer system for use in implementing the system and method of the present invention. [0012] FIGS. 2A , 2 B and 2 C are a flowchart describing a method for sensitive drug distribution at least partially utilizing a computer system such as that shown in FIG. 1 . [0013] FIG. 3 is a flowchart of a physician success program at least partially implemented on a computer system such as that shown in FIG. 1 . [0014] FIGS. 4A and 4B are a flowchart describing a method for handling refill requests at least partially utilizing a computer system such as that shown in FIG. 1 . [0015] FIG. 5 is a flowchart of a process for requesting special reimbursement when a patient is uninsured or underinsured at least partially utilizing a computer system as that shown in FIG. 1 . [0016] FIG. 6 is a flowchart of a process for inventory control at least partially utilizing a computer system such as that shown in FIG. 1 . [0017] FIG. 7 is a block diagram of database fields. [0018] FIG. 8 is a block diagram showing a list of queries against the database fields. [0019] FIG. 9 is a copy of one example prescription and enrollment form. [0020] FIG. 10 is a copy of one example of a NORD application request form for patient financial assistance. [0021] FIG. 11 is a copy of one example voucher request for medication for use with the NORD application request form of FIG. 10 . [0022] FIG. 12 is a copy of certificate of medical need. [0023] FIGS. 13A , 13 B and 13 C are descriptions of sample reports obtained by querying a central database having fields represented in FIG. 7 . DETAILED DESCRIPTION OF THE INVENTION [0024] In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims. [0025] The functions or algorithms described herein are implemented in software or a combination of software and human implemented procedures in one embodiment. The software comprises computer executable instructions stored on computer readable media such as memory or other type of storage devices. The term “computer readable media” is also used to represent carrier waves on which the software is transmitted. Further, such functions correspond to modules, which are software, hardware, firmware of any combination thereof. Multiple functions are performed in one or more modules as desired, and the embodiments described are merely examples. The software is executed on a digital signal processor, ASIC, microprocessor, or other type of processor operating on a computer system, such as a personal computer, server or other computer system. [0026] A sensitive drug is one which can be abused, or has addiction properties or other properties that render the drug sensitive. One example of such a drug is sodium oxybate, also known as gamma hydroxy butyrate (GHB C 4 H 7 NaO 3 ) which is useful for treatment of cataplexy in patients with narcolepsy. GHB is marketed under the trademark of Xyrem® (sodium oxybate oral solution), which trademark can be used interchangeably with GHB herein. Sensitive drugs also include narcotics or other drugs which require controls on their distribution and use to monitor behaviors to prevent abuse and adverse side effects. [0027] In one embodiment, Xyrem® is subject to a restricted distribution program. One aspect of the program is to educate physicians and patients about the risks and benefits of Xyrem, including support via ongoing contact with patients and a toll free helpline. Initial prescriptions are filled only after a prescriber and patient have received and read the educational materials. Further, patient and prescribing physician registries are maintained and monitored to ensure proper distribution. [0028] In a further embodiment, bulk sodium oxybate is manufactured at a single site, as is the finished drug product. Following manufacture of the drug product, it is stored at a facility compliant with FDA Schedule III regulations, where a consignment inventory is maintained. The inventory is owned by a company, and is managed by a central pharmacy, which maintains the consignment inventory. Xyrem® is distributed and dispensed through a primary and exclusive central pharmacy, and is not stocked in retail pharmacy outlets. It is distributed by overnight carriers, or by US mail in one embodiment to potentially invoke mail fraud laws if attempts of abuse occur. [0029] FIG. 1 is a simplified block diagram of a computer system 100 , such as a personal computer for implementing at least a portion of the methods described herein. A central processing unit (CPU) 110 executes computer programs stored on a memory 120 . Memory 120 in one embodiment comprises one or more levels of cache as desired to speed execution of the program and access to data on which the programs operate. The CPU is directly coupled to memory 120 in one embodiment. Both CPU 110 and memory 120 are coupled to a bus 130 . A storage 140 , I/O 150 and communications 160 are also coupled to the bus 130 . Storage 140 is usually a long term storage device, such as a disk drive, tape drive, DVD, CD or other type of storage device. In one embodiment, storage 140 is used to house a database for use with the present invention. I/O 150 comprises keyboards, sound devices, displays and other mechanisms by which a user interacts with the computer system 100 . Communications 160 comprises a network, phone connection, local area network, wide area network or other mechanism for communicating with external devices. Such external devices comprise servers, other peer computers and other devices. In one embodiment, such external device comprises a database server that is used in place of the database on storage 140 . Other computer system architectures capable of executing software and interacting with a database and users may also be used. Appropriate security measures such as encryption are used to ensure confidentiality. Further, data integrity and backup measures are also used to prevent data loss. [0030] FIGS. 2A , 2 B and 2 C represent an initial prescription order entry process for a sensitive drug, such as Xyrem. At 202 , a medical doctor (MD) sends a Rx/enrollment form via mail, fax, email or other means to an intake/reimbursement specialist at 204 , who makes a copy of the RX/enrollment form that is stamped “copy”. The original fax is forwarded to a pharmacy team. The enrollment form contains prescriber information, prescription information, checkboxes for the prescriber indicating they have read materials, educated the patient, understand the use in treatment, and understand certain safety information, and also contains patient information. [0031] The prescriber information contains standard contact information as well as license number, DEA number and physician specialty. Patient and prescription information includes name, social security number, date of birth, gender, contact information, drug identification, patient's appropriate dosage, and number of refills allowed, along with a line for the prescriber's signature. Patient insurance information is also provided. [0032] There are two workflows involved at the pharmacy team, intake reimbursement 206 and pharmacy workflow 208 , which may proceed in parallel or serially. The intake work flow 206 starts with an intake reimbursement specialist entering the patient and physician information into an application/database referred to as CHIPS, which is used to maintain a record of a client home infusion program (CHIP) for Xyrem®. A check is made to ensure the information is complete at 212 . If not, at 214 , an intake representative attempts to reach the MD or prescriber to obtain the missing information. If the missing information has not been obtained within a predetermined period of time, such as 24 hours at 216 , the Rx/Enrollment form is sent back to the MD with a rejection explanation. A note is entered in CHIPS that the application was rejected. [0033] If the information is complete at 212 , the MD is contacted at 220 to verify receipt and accuracy of the patient's Rx. This contact is recorded in CHIPS. The intake and reimbursement specialist then sends a consent form and a cover letter to the patient at 224 . The insurance provider is contacted at 226 to verify coverage and benefits. At 228 , a determination is made regarding coverage for the drug. If it is not available, it is determined at 230 whether the patient is willing and able to pay. If not, a process is performed for handling patients who are uninsured or underinsured. In one embodiment, the process is referred to as a NORD process. [0034] If the patient is willing and able to pay at 230 , the patient is informed of the cost of the product and is given payment options at 234 . At 236 , once payment is received, the intake reimbursement specialist submits a coverage approval form with the enrollment form to the pharmacy team as notification to process the patient's prescription. If coverage is approved at 228 , the intake reimbursement specialist also submits the coverage approval form with the enrollment form to the pharmacy team as notification to process the patient's prescription. Processing of the prescription is described below. [0035] Upon receipt and initial processing of the prescription enrollment form and sending an original to the pharmacy work flow block 208 , the patient is shipped a Xyrem® success packet via mail. In one embodiment, the Xyrem® success packet contains educational material for a patient that advises of the proper use, care and handling of the drug and consequences of diversion at 268 . The medical doctor's credentials are checked to determine if the physician has a current DEA license to prescribe controlled substances and if he or she has had any actions related to misuse/misprescribing of controlled drugs against him or her, within a predetermined time, such as three months at 270 . If they have, a pharmacist holds the prescription until receiving a coverage approval form from the intake reimbursement specialist at 272 . [0036] If the credentials have not been recently checked, the pharmacist verifies the credentials and enters all findings in the database at 274 . If the credentials are approved at 276 , the physician is indicated as approved in a physician screen populated by information from the database at 280 . The prescription is then held pending coverage approval at 282 . [0037] If any disciplinary actions are identified, as referenced at block 278 , management of the pharmacy is notified and either approves processing of the prescription with continued monitoring of the physician, or processing of the prescription is not performed, and the physician is noted in the database as unapproved at 284 . The enrollment form is then mailed back to the physician with a cover letter reiterating that the prescription cannot be processed at 288 . The patient is also sent a letter at 290 indicating that the prescription cannot be processed and the patient is instructed to contact their physician. [0038] Actual filling of the approved prescription begins with receipt of the coverage approval form as indicated at 240 . The patient is contacted by the pharmacy, such as by a technician to complete a technician section of a patient counseling checklist. If a pharmacist verifies that the program materials were not read at 242 , the receipt of the material is confirmed at 244 and another call is scheduled to counsel the patient before the drug is shipped. [0039] If the program materials, were read at 242 , the checklist is completed at 246 and the technician transfers the patient to the pharmacist who reviews the entire checklist and completes remaining pharmacist specified sections. At 248 , the pharmacists indicates in the database that the patient counseling and checklist was successfully completed, indicating the date completed. [0040] At 250 , the pharmacist schedules the patient's shipment for the next business day or the next business day that the patient or designee is able to sign for the package. Further, as indicated at 252 , the shipment must be sent to the patient's home address unless the patient is traveling or has moved. In that event, the pharmacist may determine that an exception may be made. The patient or the patient's designee who is at least 18 years old, must sign for the package upon delivery. [0041] At 254 , the pharmacist enters the prescription order in the database, creating an order number. The pharmacist then verifies at 256 the prescription and attaches a verification label to the hard copy prescription. At 258 , a pick ticket is generated for the order and the order is forwarded to the pharmacy for fulfillment. The shipment is confirmed in the database at 260 , and the order is shipped by USPS Express Mail. Use of the US mail invokes certain criminal penalties for unauthorized diversion. Optionally, other mail services may be used. Potential changes in the law may also bring criminal penalties into play. Following shipment, the patient is called by the central pharmacy to confirm that the prescription was received. [0042] As noted at 266 , for the sensitive drug, Xyrem, all inventory is cycle counted and reconciled with the database system quantities before shipments for the day are sent. This provides a very precise control of the inventory. [0043] A physician success program materials request process begins at 310 in FIG. 3 . At 320 , the MD calls to the central pharmacy to request program materials. A special phone number is provided. MD demographics, DEA number, and data or request are entered into the database at 330 . At 340 , a request is made to ship the materials to the MD via a fulfillment website, or other mechanism. The request process ends at 350 . [0044] A refill request process begins at 302 in FIGS. 4A and 4B . There are two different paths for refills. A first path beginning at 404 involves generating a report from the central database of patients with a predetermined number of days or product remaining. A second path beginning at 406 is followed when a patient calls to request an early refill. [0045] In the first path, a copy of the report is provided to an intake reimbursement specialist at 408 . No sooner than 8 days before the medication depletion, a pharmacy technician contacts the patient at 410 to complete the pre-delivery checklist. At 412 , if the patient is not reached, a message is left mentioning the depletion, and a return number at 414 . A note is also entered into the database indicating the date the message was left at 416 . [0046] If the patient is reached at 412 , the next shipment is scheduled at 418 , the prescription is entered into the database creating an order at 420 , the pharmacist verifies the prescription and attaches a verification label at 422 and the shipment is confirmed in the database at 424 . Note at 426 that the inventory is cycle counted and reconciled with the database quantities before the shipments for a day or other time period are sent. A pick ticket is generated for the order and the order is forwarded for fulfillment at 428 , with the first path ending at 430 . [0047] The second path, beginning at 406 results in a note code being entered into the database on a patient screen indicating an early refill request at 432 . The pharmacist evaluates the patient's compliance with therapy or possible product diversion, misuse or over-use at 436 . In one embodiment, cash payers are also identified. The pharmacist then contacts the prescribing physician to alert them of the situation and confirm if the physician approves of the early refill at 438 . If the physician does not approve as indicated at 440 , the patient must wait until the next scheduled refill date to receive additional product as indicated at 442 , and the process ends at 444 . [0048] If the physician approves at 440 , the pharmacist enters a note in the database on a patient screen that the physician approves the request at 446 . The pharmacist notifies an intake reimbursement specialist to contact the patient's insurance provider to verify coverage for the early refill at 448 . If the insurance provider will pay as determined at 450 , the specialist submits the coverage approval form as notification that the refill may be processed at 452 . At 454 , the pharmacy technician contacts the patient to schedule shipment of the product for the next business day, and the process of filling the order is continued at 456 by following the process beginning at 240 . [0049] If the insurance provider will not pay at 450 , it is determined whether the patient is willing and/or able to pay at 458 . If not, the patient must wait until the next scheduled refill date to receive additional product at 460 . If it was determined at 458 that the patient was willing and able to pay, the patient is informed of the cost of the product and is given payment options at 462 . Once payment is received as indicated at 464 , the specialist submits a coverage approval form to the pharmacy team as notification that the refill request can be processed at 466 . At 468 , the pharmacy technician contacts the patient to schedule shipment. The process of filling the order is continued at 470 by following the process beginning at 240 . [0050] A process, referred to as a NORD process in one embodiment is used to determine whether donated, third party funds are available for paying for prescriptions where neither insurance will, nor the patient can pay. The process begins at 510 upon determining that a patient is uninsured or underinsured. A reimbursement specialist explains the NORD program to the patient and faxes an application request form to NORD for the patient. At 515 , the intake reimbursement specialist documents in the database that an application has been received through NORD. At 520 , NORD mails an application to the patient within one business day. [0051] A determination is made at 525 by NORD whether the patient is approved. If not, at 530 , NORD sends a denial letter to the patient, and it is documented in the database at 540 that the patient was denied by NORD. If the patient is approved, NORD sends an acceptance letter to the patient and faxes a voucher to the central pharmacy (SDS in one embodiment) to indicate the approval at 545 . At 550 , an intake reimbursement specialist submits a coverage approval form to the pharmacy team as notification that the patient has been approved for coverage. The process of filling the order is continued at 555 by following the process beginning at 240 . [0052] An inventory control process is illustrated in FIG. 6 beginning at 610 . Each week, a responsible person at the central pharmacy, such as the director of the pharmacy transfers inventory for the week's shipments to a segregated warehouse location for production inventory. At 620 , a purchase order is generated for the inventory transferred to the production location and is sent, such as by fax, to a controller, such as the controller of the company that obtained approval for distribution and use of the sensitive drug. At 630 , the controller invoices the central pharmacy for the product moved to production. The process ends at 640 . [0053] The central database described above is a relational database running on the system of FIG. 1 , or a server based system having a similar architecture coupled to workstations via a network, as represented by communications 160 . The database is likely stored in storage 140 , and contains multiple fields of information as indicated at 700 in FIG. 7 . The organization and groupings of the fields are shown in one format for convenience. It is recognized that many different organizations or schemas may be utilized. In one embodiment, the groups of fields comprise prescriber fields 710 , patient fields 720 , prescription fields 730 and insurance fields 740 . For purposes of illustration, all the entries described with respect to the above processes are included in the fields. In further embodiments, no such groupings are made, and the data is organized in a different manner. [0054] Several queries are illustrated at 800 in FIG. 8 . There may be many other queries as required by individual state reporting requirements. A first query at 810 is used to identify prescriptions written by physician. The queries may be written in structured query language, natural query languages or in any other manner compatible with the database. A second query 820 is used to pull information from the database related to prescriptions by patient name. A third query 830 is used to determine prescriptions by frequency, and a n th query finds prescriptions by dose at 840 . Using query languages combined with the depth of data in the central database allows many other methods of investigating for potential abuse of the drugs. The central database ensures that all prescriptions, prescribers and patients are tracked and subject to such investigations. In further embodiments, the central database may be distributed among multiple computers provided a query operates over all data relating to such prescriptions, prescribers and patients for the drug. [0055] An example of one prescription and enrollment form is shown at 900 in FIG. 9 . As previously indicated, several fields are included for prescriber information, prescription information and patient information. [0056] FIG. 10 is a copy of one example NORD application request form 1000 used to request that an application be sent to a patient for financial assistance. [0057] FIG. 11 is a copy of one example application 1100 for financial assistance as requested by form 1000 . The form requires both patient and physician information. Social security number information is also requested. The form provides information for approving the financial assistance and for tracking assistance provided. [0058] FIG. 12 is a copy of one example voucher request for medication for use with the NORD application request form of FIG. 10 . In addition to patient and physician information, prescription information and diagnosis information is also provided. [0059] FIGS. 13A , 13 B and 13 C are descriptions of sample reports obtained by querying a central database having fields represented in FIG. 7 . The activities grouped by sales, regulatory, quality assurance, call center, pharmacy, inventory, reimbursement, patient care and drug information. Each report has an associated frequency or frequencies. The reports are obtained by running queries against the database, with the queries written in one of many query languages. [0060] While the invention has been described with respect to a Schedule III drug, it is useful for other sensitive drugs that are DEA or Federally scheduled drugs in Schedule II-V, as well as still other sensitive drugs where multiple controls are desired for distribution and use.

A drug distribution system and method utilizes a central pharmacy and database to track all prescriptions for a sensitive drug. Information is kept in the database regarding all physicians allowed to prescribe the sensitive drug, and all patients receiving the drug. Abuses are identified by monitoring data in the database for prescription patterns by physicians and prescriptions obtained by patients. Further verification is made that the physician is eligible to prescribe the drug by consulting a separate database, and optionally whether any actions are taken against the physician. Multiple controls beyond those for normal drugs are imposed on the distribution depending on the sensitivity of the drug.

FIELD OF THE INVENTION This invention relates to outdoor electrical boxes, and particularly, to an improved electrical cover that can mount over a standard electrical box and provide a rain tight enclosure for a wide range of standard electrical devices. BACKGROUND OF THE INVENTION Outdoor electrical outlets are commonly used to provide electrical service near gardens, swimming pools, patios and the like. Some of those used outdoors have a weatherproof enclosure for covering the outlets which may be thermostats, timers for watering systems, switches, and similar electrical devices. These outdoor enclosures are commonly referred to in the industry as FS or field service boxes. Presently, popular forms of outlet covers for providing covers to existing electrical outlets requires that the installer purchase special mounting plates, manufactured specifically for that particular box, to configure the enclosure for the particular type of electrical service that is required. As many as approximately 50 different plates may be manufactured to provide for all the different types of electrical services that may be required in typical outdoor wiring applications. The requirement to provide a special plates increases the expense of the device and also requires the electrical distributor to increase inventory in order to stock all of the special plates. The first advantage of this invention is that one configuration of the enclosure of this invention will accommodate a range of outdoor electrical devices whereas standard covers commonly used in the trade require a vast range of configurations to provide the same functionality. A second advantage is that special electrical devices and mounting plates are not required. Standard electrical devices and standard face plates that are pre-existing with the electrical outlet are re-used. SUMMARY OF THE INVENTION This invention consists of an electrical enclosure that is used outdoors in conjunction with an existing standard electrical enclosure, either flush or surface mounted. The rear surface of the enclosure has an integral adapter plate that mates with the existing standard electrical box and creates a rain tight fit when a gasket is sandwiched between the two. The integral adapter plate is designed to accommodate a wide variety of standard electrical devices including common receptacles, twist lock plug receptacles, ground fault interrupt receptacles, switches, timers, and thermostats. The pre-existing plate is then used to seal the open area around the device mounted on the adapter plate. Special electrical covers for different boxes are therefore not required with the installation since the pre-existing devices and plates that are removed from the existing flush or surface mounted box may be re-used with the enclosure of this invention. OBJECTS AND ADVANTAGES The first object of this invention to provide a simple electrical box cover that may be installed outdoors over an existing junction box, either flush or surface mounted, to provide an enclosure for standard electrical devices and their plates. A second object of the invention is to provide a universal box in one configuration that will accommodate a wide range of standard electrical devices and their plates. The invention eliminates the need for special devices and plates or multiple boxes having different configurations. A third object of the invention is to provide a rain tight enclosure for mounting pre-existing electrical devices and plates. An integral adapter plate at the rear of the adapter box provides a rain tight fit when connected to the pre-existing junction box with a gasket sandwiched therebetween. Other objects and advantages of the present invention will be better understood from the following description when read in conjunction with the appropriate drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of the universal electrical box cover of the present invention together with pre-existing standard electrical components that are commonly used in conjunction with it. FIG. 2 is a cross-sectional view of the universal electrical box including a pre-existing standard receptacle and a pre-existing standard receptacle plate. FIG. 3 is a frontal view of the universal electrical cover including an integral adapter plate located at the back of the dry box. FIG. 4 is a perspective view of the universal electrical box cover including the integral adapter plate and front cover member pivoted to its upward or open position. DESCRIPTION OF THE INVENTION The invention is a universal electrical box cover that may be used outdoors in conjunction with a pre-existing standard outlet box either flush or surface mounted to a wall. Three separate parts; the open front enclosure having an integral adapter plate, the gasket, and the front cover member are interconnected to comprise the cover. FIG. 4 is a perspective view of the universal electrical box cover 10 except for the gasket but including the open front enclosure 12 with the integral adapter plate 14, and the front cover member 16. Pins 18 connect front cover member 16 pivotally to the open front enclosure 12 at its upper end. The universal electrical box cover is used in conjunction with a pre-existing standard outlet box 20, a pre-existing standard electrical receptacle 22, and a pre-existing standard receptacle plate 24 as shown in FIG. 1. The standard outlet box 20 is typically an existing box that is either flush or surface mounted in an outdoor location. The pre-existing standard electrical receptacle 22 and pre-existing standard receptacle plate or cover 24 may be unfastened from the existing outdoor box and reused with the universal electrical cover of this invention. After the electrical power has been cut off, the electrical connections to the standard receptacle 22 need not be broken, as the receptacle may be unscrewed from the pre-existing outlet box 20 and pulled through the window or opening 27 in the gasket and the window or opening 28 in the adapter plate 14. The gasket 26 and the open front enclosure 12 are aligned with the pre-existing standard outlet box 20. The screws 21 that had previously held the receptacle to the outlet box 20 are then re-inserted through the ears of the standard receptacle 22, through the matching holes 23 in the integral adapter plate 14, and through the matching holes 25 in the gasket 26. The outer periphery of adapter plate or back plate 14 has both a front surface as shown in FIG. 1 and a back surface on the opposite side thereof. The screws 21 fasten into same threaded holes 19 in the pre-existing outlet box 20 that were previously used for fastening the receptacle. The screws 21 that are used to fasten the universal electrical cover to the existing outlet box are usually the same screws that were previously used to hold the receptacle to the outlet box. As seen in FIG. 1 the pre-existing outlet box 20 has the threaded or screw receiving holes 19 in the front face thereof. After the standard receptacle 22 is fastened securely to the pre-existing outlet box 20, holding the open front enclosure 12 and gasket 26 firmly in place, the pre-existing standard receptacle plate 24 is fastened to the receptacle in the usual manner using the pre-existing screw 31 through the pre-existing receptacle plate threaded hole 33. Although pictured separate of the enclosure 12, the front cover member 16 is pinned to the open front enclosure 12 when manufactured. As seen in FIGS. 1 to 4 the pins 18 have an enlarged head and are placed through holes 46 in cover member 16 and forced into holes 48 in enclosure 12 which have bosses 50 to accommodate the pins. The holes 46 are oversized so the cover member 16 is free to pivot. The enclosure 12 has four side walls, 60, 61, 62, and 63, which enclose a chamber 64. The gasket is preferably made of closed cell weather resistant resilient foam and is substantially planar and of a size to overlay a substantial portion of the outside rear of the integral back plate 14. The cover member 16 is simply rotated to its open position when connecting the open front enclosure 12 to the existing outlet box as previously described. A lip 30 is provided on the outer surface of the enclosure 12 at the lower end to provide a device for holding the cover member 16 in the closed position. Cover member 16 is constructed of plastic and a slotted tab (not shown in FIG. 1) on the cover mates with lip 30 which forces the tab outward. When the slot clears the lip 30 the lip snaps into the slot within the tab. After the standard electrical receptacle 22 and standard plate 24 are fastened in the universal electrical cover as mentioned above and the cover member 16 is rotated to its closed position, the universal electrical cover is a rain tight enclosure that provides weather protection to the electrical devices enclosed within. The electrical devices could be any type of electrical service commonly used outdoors, including electrical receptacles, duplex receptacles, twist-lock receptacles, ground fault interrupt receptacles, switches, timers, etc. As shown in FIG. 3, in addition to holes 23 previously mentioned, several additional holes 38 are provided in the integral adapter plate 14 for connecting any of the various electrical devices that are commonly used in outdoor applications. Likewise, the gasket 26 has similar holes that align with the holes in adapter plate 14 as well with the window 27 and the outer periphery of the gasket 26 being coextensive with the window 28 and outer periphery of the adapter plate 14. As shown in FIG. 4, the front cover member 16 has cord exit holes 32 cut in the bottom surface 42 to allow for the exit of electrical cords (not shown) that may be connected to a receptacle within the enclosure 12. The electrical cords, with the cover member 16 closed, may therefore be kept dry while plugged in. The cover member 16 has a locking hole 34 which mates with a locking hole 36 in the enclosure 12 to provide a means for locking the cover member to the enclosure. With the cover member 16 closed against the enclosure 12, the hasp of a padlock is simply slipped through the mating holes. As shown in FIG. 4, a feature which provides rain tightness is the cavernous cover member 16 of the universal electrical cover 10. The cavernous cover member 16 provides ample space for the outward projection of thick cords that may be plugged into the receptacle within the cover. FIG. 4 also shows the tab 40 on cover member 16 that mates with the lip 30 on the enclosure. Tab 40 has a slot 44 within it which the lip 30 of the dry box slips through to provide a locking feature for the cover. FIG. 2 shows a cross sectional view of the universal electrical cover 10 of this invention including the enclosure 12, gasket 26, and cover member 16. The universal electrical cover 10 is shown fastened in place to a pre-existing outlet box 20 with a pre-existing standard electrical receptacle 22 and a pre-existing standard receptacle plate 24 enclosed within. Although there has been shown and described an example of what is at present considered the preferred embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims.

A rain tight universal electrical box cover that will attach to most pre-existing, standard sized, flush or surface mounted electrical boxes and convert it into a rain tight outdoor electrical enclosure. The box cover accepts pre-existing standard electrical devices such as receptacles, switches, timers, and other similar devices and their pre-existing cover plates thereby eliminating the need to provide special provisions or numerous designs to accommodate the variety of electrical devices as is required with many of the popular electrical box covers that are commonly used in the industry today.

[0001] This application is a Divisional of application Ser. No. 10/453,137, filed on Jun. 15, 2006, which is a divisional of application Ser. No. 10/952,836, filed on Sep. 30, 2004, and for which priority is claimed under 35 U.S.C § 120; and this application claims priority of application Ser. No. 093114660 filed in Taiwan, R.O.C. on May 24, 2004 under 35 U.S.C. § 119; the entire contents of all are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an outer suspension type lens shielding mask for a projection apparatus, and more particularly to a lens shielding mask mounted outside of a projection lens and designed for matching all kinds of aspect ratios of projection pictures to reduce the leaking of the diffusion light outside of tie picture. [0004] 2. Description of Related Art [0005] Diffusion light is yielded in a general projector when light is experienced a several reflection and projection after it is emitted from an optical engine. And, a contrast is lowered after the diffusion light is leaked out through the projection lens so that the quality of a dark scene is influenced when the projector is used on such as a home video picture playing. [0006] Therefore, for lowering the darkness of the dark scenes of a motion picture in a projector to enhance the performance of contrast, an optical grating is always added in an optical engine system. But, not only needs it to add elements in entire optical engine or change a design but also helps it nothing for a currently existed projector model if the optical grating is added in the optical engine. Therefore, substantially, it is necessary to add an optical grating device without changing the internal structure of a current projector and increasing production cost. SUMMARY OF THE INVENTION [0007] The main object of the present invention is to provide an outer suspension type lens shielding mask for a projection apparatus, capable of being mounted outside of a projection lens and being designed to a static optical grating or adjustable optical grating matching with every kind of different aspect ratio of projection picture. [0008] Another object of the present invention is to provide an outer suspension type lens shielding mask for a projection apparatus, capable of reducing production cost by elevating the picture quality from the outside of the projection apparatus without changing the design of an optical engine. [0009] Still another object of the present invention is to provide an outer suspension type lens shielding mask for a projection apparatus, capable of avoiding bad shadow outside of a picture caused from diffraction light so as to improve the quality of sight amusement. [0010] For attaining to the objects mentioned above, an outer suspension type lens shielding mask for a projection apparatus according to the present invention comprises a sheet body and a holding element, in which a rectangular hole is opened in the sheet body and the sheet body is combined with the holding element together for being fixed on a projection apparatus. Another outer suspension type lens shielding mask according to the present invention comprises a base plate, in which a rectangular hole is opened in the middle part thereof, upper and lower adjustable plates, installed behind the base plate and an open rectangular notch is respectively disposed at the middle parts of the upper and the lower adjustable plates, and an adjustment mechanism, consisting a plurality of connecting elements connected to the base plate and the upper and the lower adjustable plates for adjusting the relative positions of the upper and the lower adjustable plates on the base plate. [0011] Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present invention, and in which: [0013] FIG. 1 is a prospective view, showing a lens shielding mask with a fixed type optical grating of a preferred embodiment according to the present invention; [0014] FIGS. 2A and 2B are schematic views, showing a motion for mounting a lens shielding mask with a fixed type optical grating onto a projection apparatus; [0015] FIG. 3 is an explosive view, showing a lens shielding mask with an adjustable optical grating of another preferred embodiment according to the present invention; [0016] FIG. 4 is a cross sectional view, showing an assembled lens shielding mask with an adjustable optical grating of another embodiment according to the present invention; [0017] FIG. 5 is a schematic view, showing a motion for mounting a lens shielding mask with a fixed type optical grating onto a projection apparatus; [0018] FIG. 6 is an explosive view, showing a lens shielding mask with an adjustable optical grating of still another preferred embodiment according to the present invention; and [0019] FIG. 7 is a cross sectional view, showing an assembled lens shielding mask with an adjustable optical grating of still another embodiment according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0020] Please refer to FIG. 1 . FIG. 1 is a prospective view showing a lens shielding mask with a fixed type optical grating of a preferred embodiment according to the present invention. A lens shielding mask 10 with a static optical grating mainly comprises a circular disc type sheet body 101 made from an opaque material or a flat plate coated with an opaque material on the surface thereof and used for shielding diffraction light projected from a lens of a projector; the diameter thereof is approximately equal to the inner diameter of a outer frame in front of the lens of the projector as FIGS. 2A and 2B show. A rectangular hole 102 whose shape and location depend on the type of the lens is opened in the sheet body 101 Because the aspect of a general picture is 16:9, although the ratio of the length and the width of the rectangular hole is always fabricated to be 16.9, but it can also be fabricated to be 4:3 or even 2.35:1 for accommodating it to a different aspect ratio. The hole 102 is deviated from the center of the sheet body 101 according to the present invention. A plurality of clamping ears 103 are disposed around the circumference of the sheet body 101 . These clamping ears can be formed with the sheet body 101 into one body or combined with the sheet body 101 by means of adhesion or welding. The numbers and the locations of the clamping ears 103 are not particularly defined, only that a user can mount the lens filtering mask 10 conveniently on the outer frame of the lens of the projector is enough. In addition, a material such as fiber can be stuck on the circumference of the circular sheet body 101 for being taken as a clamping element to allow the sheet body to be engaged tightly in the outer frame of the lens. [0021] The motion for mounting the lens filtering mask with a fixed type optical grating mentioned above can be seen in FIGS. 2A and 2B . A user only uses his fingers to clip the clamping ears 103 on the sheet body 101 and aims the mask at and then mounts it on the outer frame 3 outside of the lens 2 of the projector 1 . Thereafter, the fingers are again used to clip the lens filtering mask 10 to rotate the sheet body 101 until the rectangular hole is aligned with a formation zone of image after the lens shielding mask 10 is mounted on the outer frame 3 . [0022] Next, please refer to FIGS. 3 and 4 . FIGS. 3 and 4 are explosive and cross sectional views respectively showing parts and after-assembly structure of a lens shielding mask with an adjustable optical grating of another preferred embodiment according to the present invention. A lens filtering mask 20 with an adjustable optical grating comprises a base plate 201 and upper and lower adjusting plates 202 and 203 . A sleeve 2011 is disposed at each corner of the base plate 201 and a rectangular hole 204 whose shape and location is disposed depending oil the aspect of a lens is opened in the base plate 201 ; according to the present invention, the hole is symmetrical to a center line in the direction of the width of the base plate (i.e. line A-A′ in FIG. 3 ), and the center point of the hole 204 is also disposed at a location beyond the center line in the direction of the length of the base plate (i.e. line B-B′ in FIG. 3 ) according to the design of the location of a picture projected from a general projector. Furthermore, open type rectangular notches 2022 and 2032 are respectively disposed at the centers of the lower edge of the upper adjusting plate 202 and the upper edge of the lower adjustable plate 203 , the sizes of these two open type rectangular notches 2022 and 2032 are same and corresponding to each other. And, sleeves 2021 and 2031 are respectively disposed at both of the left and the right sides of the rectangular notches 2022 and 2032 of the upper and the lower adjustable plates 202 and 203 . The sizes of the center holes of the sleeves 2011 , 2021 and 2031 respectively disposed at the left and the right sides of the base plate 201 and the upper and the lower adjustable plates are same; the center lines of the center holes at the left and the light sides are respectively aligned into one line and the two lines are parallel after assembly as FIG. 4 shows. In addition, screws exist in the center holes of only one pair of the sleeve 2021 at the right side of the upper adjustable plate 202 and the sleeve 2031 at the left side of the lower adjustable plate 203 , and the sleeve 2021 at the left side of the upper adjustable plate 202 and the sleeve 2031 at the fight side of the lower adjustable plate 203 and can be extended out of them to screw thread portions 2023 and 2033 to strengthen the moving stability when the upper and the lower adjustable plates driven by a bolt 205 . For convenience in explanation, the former structure is adopted in FIGS. 3 and 4 , i.e. the screw threads are only disposed in the center holes of the sleeve 2021 at the right side of the upper adjustable plate 202 and the sleeve 2031 at the left side of the lower adjustable plate 203 . And, no screw thread exists in the center holes of all the sleeves on the base plate 201 . [0023] Please refer to FIG. 4 . When the base 201 and the upper and the lower adjustable plate 202 and 203 want to be assembled to a lens filtering mask, the upper and the lower adjustable plates 202 and 203 are first placed between the upper and the lower sleeves 2011 on the base plate 201 . Next, two bolts 205 are respectively inserted into the sleeves 2011 , 2021 , 2031 and 2011 disposed into one straight line at the two sides of the base plate and the upper and the lower adjustable plates 202 and 203 . Fixing washers 207 are then engaged with end parts 2052 of the bolts 205 to prevent the assembling elements from falling down after the bolts 205 are passed through the lowermost end of the sleeve 2011 for conforming to a different aspect of projection picture, only rotate a rotating button on the bolt 205 , and the left sleeve 2021 on the upper adjustable plate 202 engaged with the bolt 205 or/and right sleeve 2031 on the lower adjustable 203 can then be driven to move the upper or/and lower adjustable plate/plates upwards or downward to change the size of a close rectangular hole formed by the open type rectangular notches 2022 and 2032 . Generally speaking, the ratio of the length and the width of the adjusted close rectangular hole can be an aspect ratio of a general projection picture such as 4:3, 16:9, 2.35:1 or anything else. [0024] Please refer to FIG. 5 . FIG. 5 is a schematic view showing a lens shielding mask is mounted on a projector according to the present invention. When the lens shielding mask 20 wants to be mounted on the projector 1 , holding sheets on the base plate 201 are respectively clamped at the upper and the lower rims of the projector close to the projection lens 2 and the ratio of the length and the width of the close rectangular hole is adjusted according to the steps mentioned above to conform to the aspect ratio of a projection picture. [0025] Please refer to FIGS. 6 and 7 . FIGS. 6 and 7 are explosive and cross sectional views respectively showing parts and after-assembly structure of a lens shielding mask with an adjustable optical grating of still another preferred embodiment according to the present invention. A lens shielding mask 30 with an adjustable optical grating comprises a base plate 301 and upper and lower adjustable plates 302 and 303 . A sleeve 3011 is disposed on every corner of the base plate 301 ; no screw thread is existed in any one of these four sleeves. A rectangular hole 304 is further opened in the base plate 301 ; the disposition location is identical to the rectangular hole 204 in the last preferred embodiment mentioned above so that the detail thereof is omitted here. Furthermore, in the base plate 301 , two guide notches 307 are disposed at the lateral center line of the rectangular hole 304 and adjacent to the two flank sides of the base plate. Two open type rectangular notches 3022 and 3032 , which are corresponding to each other and have a same size, are respectively disposed in the middles of the lower end of the upper adjustable plate 302 and the upper end of the lower adjustable plate 303 ; the width of the open type rectangular notches are almost equal to the one of the rectangular hole in the base plate. And, a lever plate connecting seat 308 is respectively disposed at each one of the two sides of the open type rectangular notches of the upper and the lower adjustable plates 302 and 303 ; an accepting hole 3081 is opened in each connecting seat 308 . Both of sleeves 3021 and 3031 are respectively disposed at the left and the right sides of the upper and the lower adjustable plates 302 and 303 . The sizes of the center holes of the sleeves at the same sides are equal, and screw threads are disposed in the center holes of the sleeves at the same side; the threads are disposed in the center holes of the sleeves at the left sides of the plates according to the present invention only for explaining the detail easily. [0026] The assembling of the lens filtering mask 30 according to the present invention can be seen in FIG. 7 . First, a buckling pin 3091 disposed on a lever plate shown in FIG. 6 is buckled into the accepting hole 3092 disposed in a corresponding and the end of the buckling pin 3091 is engaged into the guide notch 307 , and then another buckling pin 3091 on each lever plate is engaged into the accepting hole 3081 in the each connecting seat 308 on the upper and the lower adjustable plate 302 and 303 . Each connecting point after being connected including the one between the lever plates 309 and the one between the lever plate 309 and connecting seat 308 is pivotally connected. Thereafter, the whole set of after-combination upper and lower adjustable plates 302 and 303 and the lever plate 309 are mounted between the upper and the lower sleeves 3011 on the base plate 301 . After the center holes of the sleeves 3011 , 3021 , 3031 and 3011 on the left and right sides of the base plate 30 and the upper and the lower adjustable plates 302 and 303 are aligned, a bolt with both of left and right screw threads respectively disposed on the upper and the lower parts thereof and a straight shaft shown in FIG. 6 are respectively inserted into the left and the right sides of sleeve arrays. Fixing washers are used to engage respectively with both ends of the bolt 305 and the straight shaft 306 to prevent all the assembling elements from dropping after the bolt 305 and the straight shaft 306 are passed through the lowermost end of the sleeve 3011 the upper and the lower adjustable plates 302 and 303 can be closed and opened synchronically to adjust the size of the close opening formed by the open type rectangular notches 3022 and 3032 to conform to the size of the projection picture after the bolt with left and right screw threads respectively disposed on the upper and the lower parts thereof is engaged with the sleeves 3021 and 3031 in which the threads in the center holes of them are reverse to each other respectively disposed on the left sides of the upper and the lower adjustable plates. The coordination of the lever plates 309 and guide notches 307 and the coordination of the straight shaft 306 and the sleeves on the right side are operated to guide the upper and the lower adjustable plates 302 and 303 to move up and down smoothly. [0027] Furthermore, the thread of the center holes of the sleeves at the left side can also be extended to the outsides of the sleeves to increase the driven stability of the upper and the lower adjustable plates, it is the same situation as described in the preferred embodiment of the present invention mentioned above. [0028] Besides, the holding element used in the preferred embodiment mentioned above can also be used in this preferred embodiment for mounting convenience. The detail for mounting the mask on a projector is also omitted here because it is not different from the situation mentioned in the last preferred embodiment. [0029] It is noted that the outer suspension type lens shielding mask for a projection apparatus described above is the preferred embodiments of the present invention for the purpose of illustration only, and are not intended as a definition of the limits and scope of the invention disclosed. Any modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of the present invention.

An outer suspension type lens shielding mask for a projection apparatus including a sheet body and holding element, in which a rectangular hole is opened in the sheet body, and the sheet body is combined with the holding element to be fixed on a projection apparatus Another outer suspension type lens shielding mask includes a base plate, in which a rectangular hole is opened in the middle part thereof, and upper and lower adjustable plates are installed behind the base plate An open rectangular notch is respectively disposed at the middle parts of the upper and the lower adjustable plates. An adjustment mechanism includes a plurality of connecting elements connected to the base plate and the upper and the lower adjustable plates for adjusting the relative positions thereof, to avoid bad shadows yielded outside of a picture due to light diffraction and improve the quality of visual amusement.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation-in-part of pending application Ser. No. 08/389,804 filed Feb. 16, 1995. FIELD OF THE INVENTION [0002] The present invention relates to installations for the treatment of at least one fluid, of the type comprising at least one receptacle defining a non-vertical portion of a fluid path through at least two masses of adjacent particulate material disposed in the receptacle. BACKGROUND OF THE INVENTION [0003] Installations of this type find widespread application in the art, with particulate materials such as catalysts and/or adsorbents. In most of the these uses, obtaining optimal performance depends on the constant thickness of each mass of particulate material in the direction of fluid flow, which is to say the geometric precision of the interface between two adjacent layers. Until now, particularly in installations with masses of concentric different adsorbents, this interfacial precision requires the emplacement, which is delicate and difficult, of an intermediate grid, as described in EP-A-0.118.349. SUMMARY OF THE INVENTION [0004] The present invention has for its object to provide a simplified installation for the treatment of fluid, with considerably reduced capital costs and offering great flexibility of use and numerous possibilities for optimization. [0005] To do this, according to one characteristic of the invention, the two adjacent masses of particulate material are in direct contact with each other in an interfacial region, typically substantially vertical, substantially flat or preferably substantially cylindrical. [0006] In the present invention, by “direct contact in an interfacial zone”, is intended an interfacial zone without mixing, or with slight mixing for a slight depth, free from any wall or partition interposed between the two adjacent masses. BRIEF DESCRIPTION OF THE DRAWINGS [0007] The present invention has for another object industrial uses of such installations, particularly for the treatment of air flow, for example the drying and/or separation of at least one gaseous constituent of an air flow. [0008] Other characteristics and advantages of the present invention will become apparent from the following description of embodiments given by way of non-limiting example, with respect to the accompanying drawings, in which: [0009] [0009]FIG. 1 is a schematic vertical cross-sectional view of an installation for treatment according to the invention in the course of loading according to one embodiment of the installation; [0010] [0010]FIG. 2 is a schematic perspective view of the double pouring device of FIG. 1; [0011] [0011]FIGS. 3 and 4 are views similar to FIG. 1 showing modified embodiments of the invention; [0012] [0012]FIG. 5 is a schematic plan view of another embodiment of the invention; [0013] [0013]FIG. 6 is a schematic cross-sectional view of an installation according to FIG. 5; [0014] [0014]FIG. 7 is another alternative embodiment of an installation according to the invention; [0015] [0015]FIG. 8 depicts a container in the completely filled configuration; and [0016] [0016]FIG. 9 depicts a container at the start of filling. DETAILED DESCRIPTION OF THE INVENTION [0017] In the description which follows and the drawings, identical or analogous elements bear the same reference numerals, primed as may be. [0018] In FIG. 1 there is shown a receptacle 1 of an installation for purification by adsorption of the type described in EP-A-0.118.349 mentioned above, defining an internal closed volume with a vertical axis divided internally by a tubular central grid 2 and a tubular concentric peripheral grid 3 into a central volume 4 , an annular intermediate volume 5 , and a concentric annular peripheral volume 6 , the annular intermediate volume 5 being filled with at least one, and in this case two masses of adsorbent A, B, traversed successively by the gas flowing radially between the volumes 4 and 6 and, according to the invention, having no intermediate grid. For the purification of air before its distillation or for the separation of air by so-called adsorption techniques by pressure variation (PSA or VSA), the adsorbents A and B are generally constituted of particulate materials that differ from each other according to their composition and/or their granulometry, typically of particles of alumina and/or zeolith, respectively. [0019] In the embodiment shown in FIG. 1, an apparatus for using adsorbent masses A and B according to a process of the present invention comprises two side-by-side diffusing devices 7 and 8 of an overall width less than the radial width of the intermediate volume 5 and secured to a frame 9 comprising drive means, for example rollers 10 bearing radially on the walls of the grids 2 and 3 and driven in rotation by a motor 11 carried by the frame. Each diffusion device 7 , 8 comprises a principal portion forming a particulate material reserve prolonged downwardly and rearwardly in a rear thinner portion terminating in a distribution mouth 12 , 13 , respectively, the lower anterior surface of each device 7 , 8 having for example a profile of a rounded shoe 14 prolonged rearwardly by a horizontal support surface terminating at the pouring mouth 12 , 13 . In the illustrated embodiment, the principal portions of the diffusing devices 7 and 8 are connected by telescopic or flexible conduits 15 and 16 , respectively, to reservoirs 17 and 18 of particulate material supported rotatably at 19 on the upper imperforate end of the central grid 2 . The reservoirs 17 and 18 as well as the diffusing devices 7 and 8 are so dimensioned as to be able to pass through an access opening 20 formed preferably axially in the upper end of the shell of the receptacle 1 , so as to be withdrawn after filling the intermediate volume 5 . [0020] As will be seen clearly in FIG. 2, each diffusing device 7 , 8 leaves behind it, when it is moved in the direction away from the mouths 12 , 13 , a continuous strip 21 A, 21 B of particulate material having a cross section corresponding to that of the depositing mouth 12 , 13 , and hence of constant thickness. Thus, by turning the diffusing devices 7 and 8 in the intermediate chamber 5 , they deposit at each revolution a layer of two adjacent strips 21 A, 21 B of the same thickness occupying all the radial width of the intermediate volume 5 . With each new revolution, the diffusing devices 7 and 8 , bearing on the layer previously deposited and sliding on this latter, deposit progressively a new layer, so as to build up the height of the intermediate volume 5 , after which the diffusing devices and the reservoirs 17 and 18 are withdrawn and the blocking and/or sealing means are emplaced, at the top of the intermediate volume 5 , to prevent in use local phenomena of bypassing the fluid or fluidization of the masses A and B. [0021] As will also be seen in FIG. 2, the process for producing an installation according to the invention permits emplacing side by side at least two different adsorbent beds, of different material or of the same material having different granulometries, without having to provide according to the invention any separating or containing grid between the masses of particulate materials. Thus, the simultaneous side-by-side spreading in this embodiment of the strips 21 A, 21 B, of constant controlled thickness, in practice between 1 and 20 cm, avoids problems of sloping at the edges and limits, even with very fluid particulate materials, the problems of mixing between two adjacent strips, this mixing zone being of the order of the width of the slope, which is to say of the order of three times the thickness of the spread strip if spreading is sequential, or a value which is substantially less if the spreading is, as in this preferred embodiment, simultaneous. [0022] There is shown in FIGS. 3 and 4 embodiments of filling permitting giving freedom from the requirement to deposit simultaneously or semi-simultaneously and using a sliding barrier 30 of low height, therefore disposable in the height of the receptacle at the end of the filling phase and moving vertically with the deposit of the layers of particulate material, thereby achieving, by elimination of the slope, the same precise interface upon sequential spreading or deposition as for simultaneous spreading, as previously described. There is shown in FIG. 3 the two spreading devices 7 and 8 of FIG. 1, here separate and independent, as permitted by the sliding barrier 30 , but synchronized in their operation. A sliding barrier 30 is present in the form of a section of tube disposed concentrically within the space 5 and having an axial height greater than 1.5 times the axial height of the least high mouth ( 13 ) of the spreading devices 7 , 8 , between which it extends. Preferably, the upper end of the barrier 30 comprises a radial flange 31 bearing on a turning member 32 at the top of one of the spreading devices so as to be displaced axially simultaneously with this latter, the other spreading device being actuated in rotation in synchronism with the first. [0023] The embodiment of FIG. 4 is different from that of FIG. 3 by the fact that the filling of one of the masses of particulate material, in this instance the internal mass B, is here effected by pouring from above, as permitted by the sliding barrier 30 , via a manifold 80 displaced in rotation in synchronism with the deposition, by a spreading device 7 such as described above, of strata of constant thickness according to the processes of FIGS. 1 and 3. [0024] There is shown in FIG. 5 a device with two sliding barriers for loading three masses of concentric particulate material in the internal volume defined between the interior and exterior grids 2 and 3 . As shown in FIG. 5, the device comprises a rotating device 70 , displaceable axially by being preferably suspended at the top of the receptacle 1 , with three pouring hoppers 71 , 72 , 73 , connected by transverse arms 74 and provided with members that roll or bear with low friction coacting with the radial flanges 31 1 and 31 2 of two concentric tubular sliding barriers 30 1 , 30 2 , separating the volumes of the three concentric adsorbent masses A, B, C. The dispensing hoppers 71 - 73 , fed by supplies turning with the device as in the embodiment of FIG. 1, comprise lower pouring openings 81 , 82 , 83 , opening respectively into the annular spaces between the internal barrier 31 2 and the internal grid 4 , between the barriers 31 2 and 31 1 , and between the external barrier 31 1 and the external grid 3 . After filling the zone between the grids 2 and 3 , the device 10 is demounted and removed from the receptacle 1 through the opening 20 , then the upper volume above the masses A, B, C is at least partially occupied by one or several containing devices for the upper parts of the masses A-C, for example via an inflatable member 40 connectible to a source of gas under pressure. [0025] As will be understood from the above, the principal technical problem resides in the provision of at least two homogeneous masses of particulate material within the volume confined by the adsorber, more particularly when the masses are annular and concentric: it is necessary thus to maintain the levels of the particulate material within the receptacle volume or in the spreading devices within narrow limits (the height of the successive layers in the modifications according to FIGS. 1 and 2, the height of the sliding barrier in the modifications of FIGS. 3 to 5 , the height of the hopper of the diffusing device). These heights are thus necessarily limited by the need to be able to remove the pouring or spreading devices from the receptacle at the end of filling or to leave them within a volume or within the height of this latter without their impairing the good operation of the installation. It is therefore difficult, apart from installations with receptacles of small dimensions which can be assembled in a factory, to effect the filling of an upwardly open receptacle, which permits the use of at least one sliding barrier having a height greater than a third of that of the grids 2 and 3 , that can be removed after complete filling of the receptacle whose upper end will then be welded or assembled by a ring on the peripheral edge. According to the invention, the flow of each particulate material emplaced within the receptacle must be adapted at all times so as to maintain homogeneous levels. To this end, the pouring/diffusing devices should comprise at least a control means for the flow rate of the particulate material, typically upstream of the spreading device, for example withdrawal devices with valves or lugs, as shown at 51 and 52 in FIG. 1, means for measuring the level of the particulate material in the spreading hoppers, for example, photoelectric cells as shown at 53 and 54 in FIG. 2, or reflective devices, particularly ultrasonic, as shown in 55 and 56 in FIG. 5. [0026] Represented in FIG. 7 is another alternative embodiment of concentric annular beds in a concentric-bed plant similar to the previous ones. Shown again here are the particulate-material reservoirs 17 and 18 and their rotary support 19 , in this case of the supported-arm type, which are arranged, in this case, outside the container 1 , each discharging via a hose or telescopic pipe 15 , 16 , respectively, into the adjacent annular spaces delimited, in the intermediate annular volume 5 between the perforated walls 2 and 3 , by a shell forming a slip form 30 . [0027] As may be seen on the left-hand part of FIG. 7, the lower end of each pipe, respectively 16 and 15 , emerges slightly below the upper end of the form 30 and is fastened to the latter, in a disconnectible manner, at 46 . Thus, by discharging a quantity of particulate material greater than the free volume formed by the slip form, this volume is filled until the mass of particulate material is flush with the end of the pipe 15 , 16 , which thus interrupts the filling of the said volume. The discharge is then interrupted by the valves 51 , 52 and the form shell 30 is raised, for example by cables 47 passing through the passages 40 and the openings 41 , 42 , through a height less than the height of the shell itself, that is to say with its lower end still immersed in the previously deposited layers of particulate materials, the lower ends of the pipes 15 and 16 accompanying this movement and remaining in position with respect to the shell 30 for a new charging step. [0028] In the embodiment in FIG. 7, the pipes 15 and 16 extend through filling orifices 40 formed in the upper wall of the container 1 , vertically in line with the annular space 5 and angularly distributed around the axis of the container 1 , and through openings 41 , 42 formed in deflecting plates 43 and 44 converging typically on each other as a V, leaving an annular passage 45 at their vertex and forming the upper boundary of the active part of the annular beds A and B guiding the flows of fluid, in this zone, through these beds. When the shell 30 , after the end of raising, has reached the level of the deflecting plates 43 and 44 , it is pulled up, in the example shown, through the annular space 45 between the facing ends of these deflecting plates and remains permanently housed in the upper end of the container 1 in the configuration shown by dotted lines at the top of the right-hand part of FIG. 7. The openings 41 and 42 in the plates 43 and 44 are closed off and then reserves of particulate materials are poured in via the shortened pipes 15 and 16 above the deflecting plates 44 , 43 which remain separated by the shell 30 immobilized in its upper position. Filling is completed by discharging the particulate materials directly via the orifices 40 on either side of the shell 30 , after which the pipes 15 and 16 , the reservoirs 17 and 18 and their support 19 are removed, the passages 40 closed off and the container placed in the operational condition. [0029] In the embodiment in FIG. 8, which represents a container in the completely filled configuration, the slip form 30 includes a gas-“transparent” lower part 30 A, typically in the form of sandwiches of meshes, which does not disrupt the production of a distinct interfacial zone between two contiguous beds. In this case, as shown in the right-hand part in FIG. 8, the said meshed lower part can remain immersed in the operational zone of the beds A and B, beneath the deflectors 43 , 44 . Optionally, as shown in the left-hand part in FIG. 7, the deflectors may be omitted, the upper “solid” part of the form 30 , also immersed in the masses A and B, forming an obstacle and preventing short-circuiting passages of fluid via the top of the beds. [0030] Illustrated in FIG. 9, which represents a container at the start of filling, is another embodiment of contiguous vertical layers of differentiated materials without a separating screen according to the invention. In this case, the materials are discharged, in synchronism, directly into the annular chambers beneath the filling orifices 40 . These chambers are initially delimited by a shell 33 of defined height, the upper edge of which is fixed to the roof of the container and, permanently, to their lower end, by an annular bottom wall 34 which can slide in a sealed manner along the inner 2 and outer 3 containing screens, and which is retained, during its descent, by cables 47 . The bottom wall 34 is progressively lowered until it ends up resting on the bottom structure of the container 1 , as shown by dotted lines in the lower part of FIG. 9. It will be understood that, in this embodiment, the strata of adjacent beds, formed on either side of the shell 33 “descend” progressively with the bottom 34 , while being maintained contiguous and guided by the screens 2 and 3 . When the container is completely filled, the shell 33 , which extends as far as the upper level of the “let-through” zones of the containing screens 2 and 3 , acts as an anti-bypass baffle, in the manner of the form 30 of the embodiments in FIGS. 7 and 8. [0031] Although the present invention has been described with respect to particular embodiments, it is not thereby limited but on the contrary is susceptible to modifications and variations which will be apparent to one skilled in the art. Thus, the process of FIGS. 1 and 2 can be used to deposit sequentially parallel strips in vertical non-cylindrical treatment installations, particularly to provide therein a plurality of adjacent masses of particulate materials of small thickness and having different granulometries.

An installation for the treatment of fluid comprises a receptacle ( 1 ) defining a non-vertical portion of a path for fluid through at least two adjacent masses (A; B; C) of particulate materials, typically different from each other, each mass being in direct contact with its neighbor or neighbors, without the interposition of a separating grid. The installation is particularly useful for the separation or drying of air.

This application is a continuation-in-part-application of application Ser. No. 07/789,291, filed Nov. 8, 1991 abandoned. BACKGROUND OF THE INVENTION The present invention relates to a method for the stabilization of a higher unsaturated organic compound having at least one double bond in a molecule such as those compounds used in the control of insect pests by the method of mating disruption as a sex pheromone of the insect or, more particularly, to a method for the stabilization of an ester, alcohol, ketone or hydrocarbon compound having at least 10 carbon atoms and at least one double bond in a molecule. In relation to the pest control in agriculture by using agricultural chemicals, serious problems are noted in recent years including increased resistance against chemicals acquired by the insect species and the toxicity of the chemicals against the health of the agricultural workers as well as consumers of the agricultural products due to the residual amount of the chemicals in the products. As a countermeasure for these problems, biological methods for insect pest control are now under way of intensive investigations, of which the most promising is the method of mating disruption by utilizing various kinds of chemically synthesized sex pheromone compounds as a secretion of the insect females to attract males. It is very important in this method of pest control to keep a constant rate of release of the sex pheromone compound in the field over a long period of time, for example, by the use of the sustained-release dispensers disclosed in Japanese Patent Publication No. 61-16361. In this regard, difficulties are encountered in the use of the sex pheromone compounds for the insect pests belonging to the order of Lepidoptera which are each a long-chain aliphatic compound having at least 10 carbon atoms and at least one double bond in a molecule. The presence of double bonds in such a compound is responsible for the denaturation of the compound by the reaction of oxidation, isomerization, oligomerization and the like at the double bond when the sex pheromone compound is kept under outdoor conditions. With an object to solve this problem, a method is proposed for the stabilization of a sex pheromone compound by the admixture thereof with an antioxidant or ultraviolet absorber. For example, it is reported in Journal of Chemical Ecology, volume 14, No. 8, page 1659 (1988) that the stability of a sex pheromone compound can be improved by the addition of an antioxidant such as di-tert-butyl hydroxytoluene or tert-butyl hydroxyanisole in combination with an ultraviolet absorber such as 2-hydroxy-4-methoxy benzo-phenone and the like. Further, Japanese Patent Publication 63-12452 teaches that the stability of a higher unsaturated aliphatic aldehyde compound can be increased by the combined admixture of a benzophenone compound as an ultraviolet absorber with an antioxidant and a tertiary amine compound. Although it is indeed that combined use of a specific antioxidant and a specific ultraviolet absorber synergistically contributes more to the improvement of the stability of a sex pheromone compound having a double bond in the molecular structure than in the use of either one of them alone, no quite satisfactory stabilizing effect can be obtained with any combinations of heretofore known antioxidants and known ultraviolet absorbers. Accordingly, it is eagerly desired to obtain a high stabilizing effect on various sex pheromone compounds by the combined addition of stabilizing agents. It is proposed in U.S. Pat. No. 4,568,771 that a higher aliphatic unsaturated aldehyde compound can be stabilized against oxidation by the admixture of a tertiary amine compound, benzophenone compound, salicylate compound, benzotriazole compound or cyanoacrylate compound together with or without further admixture of an antioxidant. When the sex pheromone compound is not an aldehyde but an ester, alcohol, ketone or hydrocarbon compound, no very effective method is known for the stabilization of such a compound. SUMMARY OF THE INVENTION The present invention accordingly has an object to provide a very efficient method for the stabilization of a sex pheromone compound which is a long-chain aliphatic ester, alcohol, ketone or hydrocarbon compound having at least 10 carbon atoms in a molecule and at least one double bond in the molecular structure by the admixture of compounds having a stabilizing and antioxidizing effects thereon in combination to exhibit a synergistic effect. Thus, the method of the present invention for the stabilization of a compound belonging to one of the above named classes, which is a long-chain aliphatic compound having at least 10 carbon atoms in a molecule and at least one double bond in the molecular structure, comprises: admixing the compound with 2-(2′-hydroxy-5′-methyl-phenyl) benzotriazole and a phenolic compound as an antioxidant in combination each in an amount in the range from 0.1 to 10% by weight based on the amount of the compound to be stabilized. It is preferable, in particular, that the above mentioned phenolic compound as an antioxidant is selected from the group consisting of tert-butyl hydroquinone, 2,5-di-tert-butyl hydroquinone and 2,5-di-tert-amyl hydroquinone. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The above described method of the invention for the stabilization of a higher aliphatic unsaturated compound, the scope of which consists in the combined admixture of a specific benzotriazole compound and an antioxidant or, in particular, a specific hydroquinone compound, has been established as a result of the extensive studies undertaken by the inventors with an object to discover a combination of stabilizing agents capable of synergistically stabilizing such an unsaturated compound even when it is not a long-chain aliphatic aldehyde compound having at least one double bond in a molecule, which is notoriously unstable to cause denaturation by the reaction of oxidation, isomerization and oligomerization at the double bond as well as the autoxidation reaction of the aldehyde resulting in the formation of a carboxylic acid or an oligomer. It has been unexpectedly discovered that the above described combination of the specific stabilizing agents has a strong stabilizing effect on the long-chain unsaturated aliphatic ester, alcohol, ketone and hydrocarbon compounds belonging to the classes of sex pheromone compounds having at least one double bond in a molecule. It is important that the specific benzotriazole compound and an antioxidant or, in particular, the specific hydroquinone compound are used in combination in order to exhibit a strong synergistic effect. If desired, other types of stabilizing agents can be used in combination with these two compounds. The amounts of addition of these specific benzotriazole compound and antioxidant are each in the range from 0.1 to 10% by weight based on the amount of the higher aliphatic unsaturated compound. In particular, the amount of the benzotriazole compound is preferably in the range from 1 to 5% by weight based on the amount of the higher aliphatic unsaturated compound. When the amount of either one of the compounds is too small, the desired stabilizing effect cannot be fully exhibited as a matter of course while no further improvement can be obtained by increasing the amount thereof to exceed the above mentioned upper limit rather with an economical disadvantage. Examples of the phenolic compounds as an antioxidant which can be used in combination with the specific benzotriazole compound include tert-butyl hydroquinone, 2,5-di-tert-butyl hydroquinone, 2,5-di-tert-amyl hydroquinone, 4-methoxy phenol, 2-tert-butyl-4-methoxy phenol, 3-tert-butyl-4-methoxy phenol, 2,6-di-tert-butyl-4-methoxy phenol, 2,6-di-tert-butyl-4-methyl phenol, 2,5-di-tert-butyl-3-hydroxy phenol, hydroquinone, 4,4′-methylene bis-(2,6-di-tert-butyl phenol) and the like, of which tert-butyl hydroquinone, 2,5-di-tert-butyl hydroquinone and 2,5-di-tert-amyl hydroquinone are particularly preferable in view of the high stabilizing effect on and good miscibility with the higher aliphatic unsaturated ester, alcohol, ketone or hydrocarbon compound. The method of the present invention is applicable to any one of the ester, alcohol, ketone and hydrocarbon compounds provided that it is a long-chain aliphatic compound having at least one double bond in a molecule although the advantage obtained by the inventive method is remarkably high when the method is applied to a compound selected from the group consisting of: Z-7-dodecenyl acetate; Z-8-dodecenyl acetate; Z-9-dodecenyl acetate; E,Z-7,9-dodecadienyl acetate; E,E-8,10-dodecadienyl; E-4-tridecenyl acetate; Z-9-tetradecenyl acetate; Z-9-tetradecenol; Z-11-tetradecenyl acetate; Z,E-9,11-tetradecadienyl acetate; Z,E-9,12-tetradecadienyl acetate; Z-11-hexadecenyl acetate; Z,Z-7,11-hexadecadienyl acetate; E,E,Z-4,6,10-hexadecatrienyl acetate; Z,Z-3,13-octadecadienyl acetate; E,Z-3,13-octadecadienyl acetate; Z-13-icosen-10-one; E,E,Z-10,12,14-hexadecatrienyl acetate; E,Z,Z-4,7,10-tridecatrienyl acetate; E,Z-4,7-tridecadienyl acetate; Z,Z,Z-3,6,9-nonadecatriene; Z,Z,Z-3,6,9-eicosatriene; Z,Z,Z-3,6,9-heneicosatriene and the like. In particular, the advantage obtained by the inventive method is more remarkable when the compound to be stabilized is a long-chain aliphatic compound having two or more double bonds in a molecule such as long-chain aliphatic acetates and alcohols having a 1,3- or 1,4-dienic structure among the above named compounds. In the following, the method of the present invention is illustrated in more detail by way of examples and comparative examples although the scope of the invention is never limited thereby in any way. EXAMPLE In each of the tests No. 1 to No. 20 described below, a glass capillary tube (test No. 1 to No. 5) or polyethylene capillary tube (test No. 6 to No. 20) having an inner diameter of 1 mm, outer diameter of 2 mm and length of 200 mm was filled with 100 mg of a liquid mixture of one of the higher aliphatic unsaturated compounds I to VII shown below as the test compound with 2-(2′-hydroxy-5′-methylphenyl) benzotriazole, referred to as HMBT herein-below, in an amount of 1 to 3% by weight indicated in Table 1 and one of the five phenolic compounds shown below in an amount indicated in Table 1 and kept standing outdoors as tightly stoppered to be kept outdoors and exposed to direct sun light during a period of three months starting with June in central Japan (test No. 1 to No. 5) or kept standing for three months under irradiation with a xenon lamp (test No. 6 to No. 20). After the above mentioned three months exposure, the capillary tubes were opened and the liquid mixture taken out was subjected to the gas chromatographic analysis by the internal standard method to determine the percentage of the test compound remaining undecomposed in the respective mixtures. The results are shown in Table 1. Higher Aliphatic Unsaturated Compounds (test compounds) I: E,Z-7,9-dodecadienyl acetate II: E,Z-9,11-tetradecadienyl acetate III: E,Z-9,12-tetradecadienyl acetate IV: Z,Z-7,11-hexadecadienyl acetate V: E,E-8,10-dodecadienyl VI: Z-13-icosen-10-one VII: Z,Z,Z-3,6,9-eicosatriene Phenolic Antioxidant Compounds TBH: tert-butyl hydroquinone DBH: di-tert-butyl hydroquinone DAH: di-tert-amyl hydroquinone BHT: di-tert-butyl hydroxytoluene BHA: tert-butyl hydroxyanisole TABLE 1 Test Test com- HMBT Antioxidant added Undecompos- No. pound added, % Compound % ed amount, %  1 I 2 TBH 2 93  2 I 2 BHA 2 87  3 III 3 TBH 5 91  4 IV 3 TBH 2 94  5 IV 3 BHT 2 91  6 I 1 DBH 1 75  7 I 1 DAH 5 73  8 I 1 BHT 2 71  9 II 2 DBH 2 73 10 II 2 TBH 2 68 11 II 2 DAH 1 70 12 II 2 BHT 5 69 13 III 2 DAH 2 75 14 III 2 TBH 2 71 15 III 2 DBH 10 83 16 IV 1 DBH 0.2 89 17 V 1 BHT 2 88 18 V 1 DBH 1 85 19 VI 1 TBH 1 91 20 VII 2 DBH 5 67 COMPARATIVE EXAMPLE The experimental procedure in each of the comparative tests No. 21 to No. 3 was substantially the same as in the preceding tests by using a glass capillary tube under exposure to direct sun light (test No. 21 to 25) or by using a polyethylene capillary tube under irradiation with a xenon lamp (test No. 26 to No. 36) except that, in some of the tests, the stabilizing agents were entirely omitted, the HMBT was replaced with one of the substitute compounds 2-hydroxy-4-methoxy benzophenone, referred to as HMBP hereinbelow, and 2-hydroxy-4-octoxy benzophenone, referred to as HOBP hereinbelow, or the phenolic antioxidant compound was replaced with one of other antioxidant compounds identified below each in an amount indicated in Table 2. The results of the tests are shown in Table 2. Non-phenolic Antioxidant Compounds QL: quinoline VE: tocopherol VEN: tocopherol nicotinate TABLE 2 HMBT or substitute Test Test com- com- Antioxidant added Undecompos- No. pound pound % added compound % ed amount, % 21 I none none 8 22 I HMBP 5 BHA 5 52 23 III none BHA 5 54 24 IV none none 43 25 IV HMBP 5 TBH 1 76 26 I HOBP 2 VE 5 46 27 I HOBP 2 QL 1 34 28 II HOBP 2 VE 1 43 BHT 1 29 II HMBP 2 QL 5 39 30 II HMBT 2 QL 3 41 31 III HMBP 2 QL 5 28 32 III HOBP 2 VEN 5 33 33 III HMBT 3 VE 5 36 34 III HOBP 2 QL 3 40 DBH 1 35 V HMBP 2 QL 5 21 36 VII HOBP 2 VE 2 38 BHA 2

An efficient method is proposed for the stabilization of a sex pheromone compound of insect pest, which is a long-chain aliphatic unsaturated ester, alcohol, ketone or hydrocarbon compound having at least ten carbon atoms and at least one double bond in a molecule, used in pest control. The method comprises admixing the compound with 2-(2′-hydroxy-5′-methylphenyl) benzotriazole and an antioxidant which is preferably a hydroquinone compound such as tert-butyl hydroquinone, 2,5-di-tert-butyl hydroquinone and 2,5-di-tert-amyl hydroquinone.

BACKGROUND OF THE INVENTION [0001] This invention relates to shaft journal bearings and, more particularly, to an improved bearing assembly seal arrangement for use in a railway freight car. [0002] Roller bearing assemblies incorporating two rows of tapered roller bearings preassembled into a self-contained, pre-lubricated package for assembly onto journals at the ends of axles or shafts are known. Such bearing assemblies are used as rail car bearings assembled onto journals at the ends of the axles. Bearings of this type typically employ two rows of tapered roller bearings fitted one into each end of a common bearing cup with their respective bearing cones having an inner diameter dimensioned to provide an interference fit with the shaft journal and with a cylindrical sleeve or spacer positioned between the cones providing accurate spacing and proper lateral clearance on the journal. Seals mounted within each end of the bearing cup provide sealing contact with wear rings bearing against the outer ends or back face of the respective bearing cones at each end of the assembly. Such seals are shown in U.S. Pat. Nos. 5,975,533, 7,607,836, and 7,534,047. [0003] In a typical rail car installation, the axle journal is machined with a fillet at the inboard end. A backing ring having a surface complementary to the contour of the fillet and an abutment surface for engaging the inboard end of an inner wear ring accurately position the bearing assembly on the journal. An end cap mounted on the end of the axle by bolts threaded into bores in the end of the axle engages the outboard wear ring and clamps the entire assembly on the end of the axle. The wear rings typically have an inner diameter dimensioned to provide interference fit with the journal over at least a portion of their length so that the entire assembly is pressed as a unit onto the end of the journal shaft portion of the axle. SUMMARY OF THE INVENTION [0004] The bearing assembly of the present invention is a roller bearing that includes an inner race or cone fitted around the journal portion of the axle or shaft. The inner race includes an outwardly directed raceway. An outer race or cup has an inwardly directed raceway. Roller elements are located between and contacting the inner and outer raceways. [0005] A backing ring has a contoured surface complementary to and engaging the contoured surface of a fillet formed on the shaft. The fillet leads from the journal to the shoulder of the shaft. The contoured surfaces cooperate to fix the backing ring against axial movement along the shaft. [0006] The bearing assembly includes a seal assembly that provides a barrier for lubricant to be retained within the seal assembly and for contaminants to be kept out. A slinger is provided to interact with a wear ring and a seal element to provide an improved seal. The inter-related relationship between the seal element, wear ring, and slinger act to retain the lubricant within the seal assembly and to keep contaminants out. BRIEF DESCRIPTION OF THE DRAWINGS [0007] In the drawings, [0008] FIG. 1 is a sectional view of a shaft journal having mounted thereon a tapered roller bearing assembly in accordance with a first embodiment of the present invention; [0009] FIG. 2 is a detailed partial view in cross section of a tapered roller bearing seal assembly in accordance with the first embodiment of the present invention; [0010] FIG. 3 is a detailed view in partial cross section of a tapered roller bearing assembly in accordance with a second embodiment of a present invention, and [0011] FIG. 4 is a detailed view in partial cross section of a tapered roller bearing assembly in accordance with a third embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0012] Referring now to FIG. 1 of the drawings, a bearing assembly indicated generally by the reference numeral 10 on FIG. 1 is shown mounted on a journal 12 on the free, cantilevered end of a shaft or axle 14 , typically a rail car axle. Journal 12 is machined to very close tolerances and terminates at its inner end in a contoured fillet 22 leading to a cylindrical shoulder 18 of axle 14 . At the free end of the axle, journal portion 12 terminates in a slightly conical or tapered guide portion 24 dimensioned to facilitate installation of the bearing assembly onto the journal. A plurality of threaded bores 26 are formed in the end of axle 14 for receiving threaded cap screws, or bolts 28 for mounting a bearing retaining cap 30 on the end of the shaft to clamp the bearing in position as described more fully herein below. [0013] Bearing assembly 10 is preassembled before being mounted and clamped on journal 12 by retaining cap 30 and bolts 28 . The bearing assembly includes a unitary bearing cup or outer raceway 32 having a pair of inner facing raceways 34 , 36 formed one adjacent each end thereof which cooperate with a pair of bearing cones 38 , 40 , having outer facing raceways respectively, to support the two rows of tapered rollers 42 , 44 , respectively there between. A center spacer 46 is positioned between cones 38 , 40 to maintain the cones in accurately spaced position relative to one another allowing for proper bearing lateral clearance. [0014] Bearing cup 32 is provided with cylindrical counterbores 17 , 19 at its axially outer ends and a pair first end sections 48 , 50 of seal sections 52 , 54 are pressed one into each of the cylindrical counterbores 17 , 19 in cup 32 . Each second end section 55 , 63 of seal section 52 , 54 may include resilient sealing elements 56 , 58 which rub upon and form a seal with radial outer surfaces 37 , 61 of a pair of seal wear rings 60 , 62 having an inwardly directed end in engagement with the outwardly directed ends of bearing cones 38 , 40 respectively. Seal section 54 is similar to seal section 52 and will not be described in detail. The other end of wear ring 60 is received in a cylindrical counterbore 64 in the axially outwardly directed end of an annular backing ring 66 which, in turn, has a counterbore 68 at its other end which is dimensioned to be received in interference and non-interference relation on the cylindrical shoulder 18 of shaft 14 . The counterbore 64 and the outer diameter of wear ring 60 are also dimensioned to provide an interference fit so that wear ring 60 is pressed into the backing ring 66 which is accurately machined to provide a contoured inner surface 70 complementary to and engaging the contour of fillet 22 when the bearing is mounted on the shaft. The outwardly directed end of wear ring 62 bears against a counterbore 31 in a retaining cap 30 . [0015] Referring now to FIG. 2 , a detailed view of seal assembly portion of bearing assembly 10 is provided. Seal section 52 is seen to comprise a generally cylindrical piece, having a larger diameter first end section 48 pressed or fit into a complementary counterbore 17 in a cup 32 . Seal section 52 includes an intermediate section 27 normal to first end section 48 and a main intermediate cylindrical section 53 that extends parallel to end section 48 , wherein main intermediate cylindrical section 53 has a smaller diameter than first end section 48 . [0016] Second end section 55 of seal section 52 extends from main intermediate section 53 at a normal angle thereto. Resilient sealing element 56 is fitted onto second end section 55 . Resilient sealing element 56 is comprised of a rubber or elastomer compound, such as nitrile rubber compound. Resilient sealing element 56 includes a main section that includes an opening to receive second end section 55 of seal section 52 . [0017] Slinger section 72 comprises a generally cylindrical structure having a base section 74 attached to outer surface 37 of seal wear ring 60 and end section 76 extending from base section 74 . Slinger section 72 is usually a unitary structure comprised of a structural plastic or steel. [0018] Referring now to FIG. 3 , a second embodiment of the roller bearing seal assembly of the present invention is shown generally at 110 . Elements such as bearing cup 32 , backing ring 66 , seal section 52 and seal wear ring 60 are similar to FIGS. 1 and 2 and are similarly numbered. [0019] Slinger section 172 comprises a generally cylindrical structure having a base section 174 attached to outer surface 37 of seal wear ring 60 , an intermediate section 178 extending from base section 174 , and end section 176 extending from and at an angle of approximately 90 degrees to intermediate section 178 . Intermediate section 178 is seen to have a protrusion 178 A that contacts the axially inward facing surface 55 A of second end section 55 of seal section 52 . Slinger section 172 is usually a unitary structure comprised of a structural plastic or steel. Slinger end section 176 extends toward and is adjacent the radial outer surface of main intermediate cylindrical section 53 of seal section 52 . [0020] Referring now to FIG. 4 , a third embodiment of the roller bearing seal assembly of the present invention is shown generally at 210 . Elements such as seal section 52 and seal wear ring 60 with radial outer surface 37 are similar to FIGS. 1 and 2 and are similarly numbered. However, backing ring 266 is seen to have an annular protrusion 268 extending axially from its outer radial surface. [0021] Slinger section 272 comprises a generally cylindrical structure having a base section 274 attached to outer surface 37 of seal wear ring 60 , an intermediate section 278 extending from base section 274 , and end section 276 extending from and normal to intermediate section 278 . Slinger section 272 is usually a unitary structure comprised of a structural plastic or steel. Intermediate section 278 is seen to have a protrusion 278 A that contacts the axially inward facing surface 55 A of second end section 55 of seal section 52 . Slinger end section 276 extends at a radius and an angle of approximately 90 degrees from intermediate section 278 and extends toward and is adjacent the radial outer surface of main intermediate cylindrical section 53 seal section 52 .

A bearing assembly is provided having a roller bearing with an inner raceway fitted around the journal portion of an axle. An outer raceway combines with the inner raceway to receive roller elements. An improved lubricant seal arrangement is provided between the wear ring and the supporting outer raceway comprising a slinger element.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to pyrido[2,3-b]indolizine derivatives and aza analogues thereof that selectively bind to corticotropin-releasing factor (CRF) receptors. It also relates to pharmaceutical compositions comprising such compounds. It further relates to the use of such compounds in treating stress related disorders such as post traumatic stress disorder (PTSD) as well as depression, headache and anxiety. [0003] 2. Description of the Related Art [0004] Posselt, K., Arzneim.-Forsch. 1978, 28, 1056-65, describe the synthesis of 10-(4-methoxyphenyl)pyrido[2,3-b]indolizine. Volovenko et al., Khim. Geterotsikl. Soedin. 1991, 6, 852, describe the synthesis of 2-chloro and 2-methylthio-10-tosylmethylpyrimido[4,5-b]indolizine. SUMMARY OF THE INVENTION [0005] This invention provides novel compounds of Formula I which interact with CRF receptors. [0006] In one aspect, the invention provides pharmaceutical compositions comprising compounds of Formula I. In another aspect, it provides compositions useful in treating stress related disorders such as post traumatic stress disorder (PTSD) as well as depression, headache and anxiety. These compositions include a compound of Formula I. Further, in a third aspect, the invention provides methods of treating such stress related disorders. [0007] Accordingly, a broad aspect of the invention is directed to compounds of Formula I: [0008] Ar is phenyl, 1- or 2-naphthyl, 2-, 3-, or 4-pyridyl, 2- or 3-thienyl, 4- or 5-pyrimidyl, each of which is optionally mono-, di-, or trisubstituted with halogen, trifluoromethyl, hydroxy, amino, mono- or di(C 1 -C 6 ) alkyl amino, carboxamido, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkoxy, with the proviso that at least one of the positions ortho or para to the point of attachment of Ar to the tricyclic ring system is substituted; [0009] R 1 and R 2 independently represent [0010] C 1 -C 6 alkyl; [0011] C 3 -C 7 cycloalkyl; [0012] C 3 -C 7 cycloalkyl(C 1 -C 6 )alkyl; [0013] C 1 -C 6 alkoxy(C 1 -C 6 )alkyl; or [0014] aryl(C 1 -C 6 )alkyl where aryl is phenyl, 1- or 2-naphthyl, 2-, 3-, or 4-pyridyl, 2- or 3-thienyl or 2-, 4 or 5-pyrimidyl, each of which is optionally mono- or disubstituted with halogen, hydroxy, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 1 -C 6 alkoxy, or (C 1 -C 6 alkylene)—A—R 4 , wherein A is O, S, NH, or N(C 1 -C 6 alkyl) and R 4 is hydrogen, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkyl; or [0015] R 1 and R 2 taken together represent —(CH 2 ) n —A—(CH 2 ) m — wherein n is 2, 3 or 4, A is methylene, oxygen, sulfur, or NR 5 , wherein R 5 is hydrogen, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkyl, and m is 0, 1, or 2; [0016] R 3 is C 1 -C 6 alkyl, or (C 1 -C 6 alkylene)—G—R 6 , wherein G is O, S, NH, or N(C 1 -C 6 alkyl) and R 6 is hydrogen, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkyl; and [0017] W, X, Y, and Z are independently N or C—R 7 , wherein R 7 is hydrogen, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkyl. [0018] These compounds are highly selective partial agonists or antagonists at CRF receptors and are useful in the diagnosis and treatment of stress related disorders such as post traumatic stress disorder (PTSD) as well as depression and anxiety. [0019] Another aspect of the invention is directed to intermediates useful in the preparation of the compounds of Formula I. [0020] In a further aspect, the invention provides methods for making the compounds of Formula I and the intermediates for preparing such compounds. DETAILED DESCRIPTION OF THE INVENTION [0021] Preferred compounds of Formula I are those where Ar is phenyl substituted in the 2, 4, and 6 positions, preferably with methyl, ethyl or propyl; naphthyl substituted in the 2 and 6 positions, preferably with methyl, ethyl or propyl; or 3-pyridyl substituted in the 2, 4, and 6 positions, preferably with methyl, ethyl or propyl; 5-pyrimidiyl substituted in the 2, 4, and 6 positions, preferably with methyl, ethyl, or propyl. Particularly, preferred components of Formula I include those where the Ar group is substituted in the 2 and 6 or the 2, 4, and 6 positions with methyl. [0022] Preferred compounds of the invention have Formula II: [0023] wherein Ar, R 1 , R 2 , and R 3 are as defined above for Formula I; and [0024] X, Y, and Z are independently N or C—R 7 , wherein R 7 is hydrogen, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkyl. [0025] Preferred compounds of Formula II are those where X and Z are both CH and Y is CH or nitrogen. More preferred compounds of Formula II are those where R 3 is C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl(C 1 -C 3 )alkyl. Other more preferred compounds of Formula II are those where R 1 and R 2 independently represent C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl(C 1 -C 6 )alkyl, —(CH 2 ) 2 O(CH 2 ) 2 —; and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. Particularly preferred compounds of the Formula II are those where Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. [0026] Other particularly preferred compounds of Formula II are those where X, Y and Z are all CH. [0027] Other preferred compounds of the invention have Formula III [0028] wherein Ar, R 1 , R 2 , and R 3 are as defined above for Formula I; and [0029] X and Z are independently N or C—R 7 , wherein R 7 is hydrogen, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkyl [0030] More preferred compounds of Formula III are those where R 3 is C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl(C 1 -C 3 )alkyl. Other more preferred compounds of Formula III are those where R 1 and R 2 independently represent C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl(C 1 -C 6 )alkyl, —(CH 2 ) 2 O(CH 2 ) 2 —; and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. Particularly preferred compounds of the Formula III are those where Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. [0031] Still other preferred compounds of the invention have formula: [0032] wherein [0033] wherein Ar, R 1 , R 2 , and R 3 are as defined above for Formula I; and [0034] W, X, and Z are independently N or C—R 7 , wherein R 7 is hydrogen, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkyl. [0035] Preferred compounds of Formula IV are those where X and Z are both CH. [0036] More preferred compounds of Formula IV are those where R 3 is C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl(C 1 -C 3 )alkyl. Other more preferred compounds of Formula IV are those where R 1 and R 2 independently represent C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl(C 1 -C 6 )alkyl, —(CH 2 ) 2 O(CH 2 ) 2 —; and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. Particularly preferred compounds of the Formula IV are those where Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. [0037] Other particularly preferred compounds of IV are those where W is CH and X and Z are both CH. [0038] Yet other preferred compounds of the invention have formula: [0039] wherein Ar, R 1 , R 2 , and R 3 are as defined above for Formula I; and [0040] X and Z are independently N or C—R 7 , wherein R 7 is hydrogen, C 3 -C 7 cycloalkyl, or C 1 -C 6 alkyl. [0041] Preferred compounds of Formula V are those where R 3 is C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl(C 1 -C 3 )alkyl. Other more preferred compounds of Formula V are those where R 1 and R 2 independently represent C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl(C 1 -C 6 )alkyl, —(CH 2 ) 2 O(CH 2 ) 2 —; and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. Particularly preferred compounds of the Formula V are those where Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. [0042] The invention also provides intermediates useful in preparing compounds of Formula I. These intermediates have Formulae VI-X. [0043] where Ar, and X, Y and Z are defined as above for Formula I. [0044] Preferred compounds of Formula VI are those where Y is CH or N and X and Z are CH, and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the methylene group. Particularly preferred compounds of the Formula VII are those where Y is CH or N, X and Z are CH, and Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the methylene group. [0045] where R 8 is NH 2 or N═C(R 3 )C(R 7 ) where R 3 and R 7 are as defined above for Formula I; and [0046] Ar, and X, Y and Z are defined as above for Formula I. [0047] Preferred compounds of Formula VII are those where Y is CH or N and X and Z are CH, and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the bicyclic ring system. Particularly preferred compounds of the Formula VII are those where Y is CH or N; X and Z are CH; and Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the bicyclic ring system. [0048] where R 9 is halogen or hydroxy; and R 3 , R 7 , Ar, and X, Y and Z are defined as above for Formula I. [0049] Preferred compounds of Formula VIII are those where Y is CH or N; X and Z are CH; and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. Particularly preferred compounds of the Formula VIII are those where Y is CH or N; X and Z are CH; and Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. [0050] where R 10 is NH 2 or NHC(O)R 3 , where R 3 is as defined above for Formula I; and Ar, and X, Y and Z are defined as above for Formula I. [0051] Preferred compounds of Formula IX are those where Y is CH or N; X and Z are CH; and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the bicyclic ring system. Particularly preferred compounds of the Formula IX are those where Y is CH or N; X and Z are CH; and Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the bicyclic ring system. [0052] where R 3 , Ar, X, Y and Z are defined as above for Formula I. [0053] Preferred compounds of Formula X are those where Y is CH or N; X and Z are CH; and Ar is phenyl trisubstituted with C 1 -C 3 alkyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. Particularly preferred compounds of the Formula X are those where Y is CH or N; X and Z are CH; and Ar is phenyl trisubstituted with methyl in the 2, 4, and 6 positions relative to the point of attachment of Ar to the tricyclic ring system. [0054] In certain situations, the compounds of Formula I may contain one or more asymmetric carbon atoms, so that the compounds can exist in different stereoisomeric forms. These compounds can be, for example, racemates or optically active forms. In these situations, the single enantiomers, i.e., optically active forms, can be obtained by asymmetric synthesis or by resolution of the racemates. Resolution of the racemates can be accomplished, for example, by conventional methods such as crystallization in the presence of a resolving agent, or chromatography, using, for example a chiral HPLC column. [0055] Representative compounds of the present invention, which are encompassed by Formula I, include, but are not limited to the compounds in Table I and their pharmaceutically acceptable acid addition salts. In addition, if the compound of the invention is obtained as an acid addition salt, the free base can be obtained by basifying a solution of the acid salt. Conversely, if the product is a free base, an addition salt, particularly a pharmaceutically acceptable addition salt, may be produced by dissolving the free base in a suitable organic solvent and treating the solution with an acid, in accordance with conventional procedures for preparing acid addition salts from base compounds. [0056] Non-toxic pharmaceutical salts include salts of acids such as hydrochloric, phosphoric, hydrobromic, sulfuric, sulfinic, formic, toluenesulfonic, methanesulfonic, nitric, benzoic, citric, tartaric, maleic, hydroiodic, alkanoic such as acetic, HOOC—(CH 2 )n—COOH where n is 0-4, and the like. Those skilled in the art will recognize a wide variety of non-toxic pharmaceutically acceptable addition salts. [0057] The present invention also encompasses the acylated prodrugs of the compounds of Formula I. Those skilled in the art will recognize various synthetic methodologies which may be employed to prepare non-toxic pharmaceutically acceptable addition salts and acylated prodrugs of the compounds encompassed by Formula I. [0058] Where a compound exists in various tautomeric forms, the invention is not limited to any one of the specific tautomers. The invention includes all tautomeric forms of a compound. [0059] By “C 1 -C 6 alkyl” or “lower alkyl” in the present invention is meant straight or branched chain alkyl groups having 1-6 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, 2-pentyl, isopentyl, neopentyl, hexyl, 2-hexyl, 3-hexyl, and 3-methylpentyl. Preferred C 1 -C 6 alkyl groups are methyl, ethyl, propyl, butyl, cyclopropyl and cyclopropylmethyl. [0060] By “C 1 -C 6 alkoxy” or “lower alkoxy” in the present invention is meant straight or branched chain alkoxy groups having 1-6 carbon atoms, such as, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentoxy, 2-pentyl, isopentoxy, neopentoxy, hexoxy, 2-hexoxy, 3-hexoxy, and 3-methylpentoxy. [0061] By the term “halogen” in the present invention is meant fluorine, bromine, chlorine, and iodine. [0062] Representative pyrido[2,3-b]indolizine derivatives and their aza analogues of the present invention are shown in Table 1. The number below each compound is its compound number. TABLE 1 1 2 3 4 5 6 [0063] The interaction of compounds of the invention with CRF receptors is shown in the examples. This interaction results in the pharmacological activities of these compounds as illustrated in relevant animal models. [0064] The compounds of general formula I may be administered orally, topically, parenterally, by inhalation or spray or rectally in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In addition, there is provided a pharmaceutical formulation comprising a compound of general formula I and a pharmaceutically acceptable carrier. One or more compounds of general formula I may be present in association with one or more non-toxic pharmaceutically acceptable carriers and/or diluents and/or adjuvants and if desired other active ingredients. The pharmaceutical compositions containing compounds of general formula I may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsion, hard or soft capsules, or syrups or elixirs. [0065] Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monosterate or glyceryl distearate may be employed. [0066] Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin or olive oil. [0067] Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydropropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example, lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin. [0068] Oily suspensions may be formulated by suspending the active ingredients in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and flavoring agents may be added to provide palatable oral preparations. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid. [0069] Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present. [0070] Pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oil, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol, anhydrides, for example sorbitan monoleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monoleate. The emulsions may also contain sweetening and flavoring agents. [0071] Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be sterile injectable solution or suspension in a non-toxic parentally acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono-or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables. [0072] The compounds of general formula I may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials are cocoa butter and polyethylene glycols. [0073] Compounds of general formula I may be administered parenterally in a sterile medium. The drug, depending on the vehicle and concentration used, can either be suspended or dissolved in the vehicle. Advantageously, adjuvants such as local anesthetics, preservatives and buffering agents can be dissolved in the vehicle. [0074] Dosage levels of the order of from about 0.1 mg to about 140 mg per kilogram of body weight per day are useful in the treatment of the above-indicated conditions (about 0.5 mg to about 7 g per patient per day). The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. Dosage unit forms will generally contain between from about 1 mg to about 500 mg of an active ingredient. [0075] It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, and rate of excretion, drug combination and the severity of the particular disease undergoing therapy. [0076] The preparation of the pyrido[2,3-b]indolizines and aza analogues thereof of the present invention is illustrated in Schemes I and II. Those having skill in the art will recognize that the starting materials may be varied and additional steps employed to produce compounds encompassed by the present invention. [0077] In Scheme I, the variables Ar, R 1 , R 2 , R 3 , R 7 , X, Y, and Z are defined as above for Formula I. [0078] In Scheme I, the variables Ar, R 1 , R 2 , R 3 , X, Y, and Z are defined as above for Formula I. [0079] The disclosures of all articles and references mentioned in in this application, including patents, are incorporated herein by reference. [0080] The preparation of the compounds of the present invention is illustrated further by the following examples which are not to be construed as limiting the invention in scope or spirit to the specific procedures and compounds described in them. [0081] Commercial reagents were used without further purification. DMSO refers to dimethyl sulfoxide. THF refers to tetrahydrofuran. DMF refers to dimethylformamide. Room temperature refers to 20° to 25° C. Concentration in vacuo implies the use of a rotary evaporator. Chromatography refers to flash column chromatography performed using 32-63 mm silica gel. Proton NMR chemical shifts are reported in parts per million (d) relative to tetramethylsilane as an internal standard. EXAMPLE 1 [0082] A. 2-(2-Pyridinyl)-2-(2,4,6-trimethylphenyl)ethanenitrile [0083] A mixed solution of 2-(2,4,6-trimethylphenyl)ethanenitrile (20 g; 0.126 mol) and 2-bromopyridine (35 g; 0.22 mol) in DMSO (25 mL) is added to a solution of potassium t-butoxide (35 g; 0.31 mol) dissolved in DMSO (125 mL) dropwise slowly over a 1-hour period. After the addition, the mixture is further stirred for 4 hours at room temperature and then slowly poured into a stirred, ice-cold solution of ammonium chloride with vigorous stirring. The resulting tan precipitate is filtered, pressed, washed with methanol, and air-dried to give 20 g of the title compound as a pale yellow solid (67%): 1 H nmr (400 MHz, CDCl 3 ) d 2.30 (s, 6 H), 2.32 (s, 3 H), 5.76 (s, 1 H), 6.93 (s, 2 H), 7.12 (d, 1 H), 7.21 (dd, 1 H), 7.63 (t, 1 H), 8.63 (d, 1 H). [0084] B. Ethyl 2-amino-1-(2,4,6trimethylphenyl)indolizine-3-carboxylate [0085] Ethyl bromoacetate (23 mL; 0.21 mol) is added slowly dropwise over a 3-hour period to a mixture of 2-(2-pyridinyl)-2-(2,4,6-trimethylphenyl)-ethanenitrile (22.3 g; 0.094 mol) and potassium carbonate (78 g; 0.57 mol) suspended in DMSO (100 mL). The mixture is stirred for 1 day, poured into an aqueous ammonium chloride solution (ca. 1 L), and extracted with three 200 mL portions of ethyl ether. Combined extracts are washed with saturated brine, dried (Na 2 SO 4 ), filtered, and concentrated in vacuo. The residue is dissolved in THF (200 mL), cooled to 0° C., and potassium t-butoxide (12 g; 0.11 mol) is added slowly in portions over a 10-minute period. After 30 minutes at 0° C., the mixture is diluted with aqueous ammonium chloride and extracted twice with 150 mL portions of 50% ethyl ether in hexane. The combined extracts are washed with saturated brine, dried (Na 2 SO 4 ), filtered, concentrated in vacuo, and chromatographed (5 to 10% ethyl acetate in hexane) to give 19.2 g of the title compound as an oil (63%): 1 H nmr (400 MHz, CDCl 3 ) d 1.47 (t, 3 H), 2.06 (s, 6 H), 2.35 (s, 3 H), 4.46 (br q, 2 H), 6.6 (br t, 1 H), 6.75 (d, 1H), 6.9 (br t, 1 H), 7.00 (s, 2 H), 9.4 (br 1 H). [0086] C. 4-Hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyrido[2,3-b]-indolizine [0087] To a solution of 2-amino-3-ethoxycarbonyl-1-(2,4,6-trimethylphenyl)-indolizine (19.2 g; 59.6 mmol) in 2,2-dimethoxypropane (100 mL) is added di-camphorsulfonic acid (0.2 g). The mixture is stirred at reflux for 30 minutes and then distilled slowly to remove ca. 60 mL of volatiles over a 30-minute period. The solution is cooled to ambient temperature under an inert atmosphere, diluted with anhydrous toluene (50 mL), and concentrated in vacuo. The residue is dissolved in toluene (50 mL) and to the stirred solution is then added a 0.5M solution of potassium bis(trimethylsilyl)amide in toluene (250 mL; 125 mmol) dropwise over a 1-hour period. After the addition is complete, the mixture is further stirred for 2 hours at room temperature before being concentrated in vacuo to a small volume and then diluted with aqueous ammonium chloride. The resulting emulsion-like biphasic mixture is suction-filtered and washed succesively with water, methanol, and ethyl ether. Air- and vacuum drying provides 10.1 g of the title compound as a pale yellow solid (54%). [0088] D. 4-Chloro-2-methyl-10-(2,4,6-trimethylphenyl)pyrido[2,3-b]-indolizine [0089] A solution of 4-hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyrido-[2,3-b]indolizine (10.1 g; 32 mmol) in phosphorus oxychloride (60 mL) is heated at 100° C. for 1 hour, cooled to room temperature, and concentrated in vacuo. The residue is partitioned into ice water and dichloromethane. The aqueous phase is separated and extracted twice with dichloromethane. The combined organics are washed with a 1 N aqueous sodium hydroxide solution and then with water. The solution is dried (Na 2 SO 4 ), filtered, and concentrated in vacuo, and the resulting dark residue is filtered through a short pad of silica gel and washed with 25% ethyl acetate in hexane. The filtrate is concentrated in vacuo to give 10.1 g of the title compound as a yellow solid (94%): 1 H nmr (400 MHz, CDCl 3 ) d 2.00 (s, 6 H), 2.37 (s, 3 H), 2.64 (s, 3 H), 6.58 (t, 1 H), 6.95 (dd, 1 H), 7.00 (s, 2 H), 7.07 (s, 1 H), 7.08 (d, 1 H), 9.26 (d, 1 H). [0090] E. 4-(N,N-Dipropyl)amino-2-methyl-10-(2,4,6-trimethylphenyl)-pyrido[2,3]indolizine [0091] A mixture of 4-chloro-2-methyl-10-(2,4,6-trimethylphenyl)pyrido[2,3-b]indolizine (10.0 g; 30 mmol) and dipropylamine (15 mL; 1 mol) in DMSO (30 mL) is heated at 130° C. under nitrogen atmosphere for two days. The mixture is cooled to room temperature, diluted with water (ca. 300 mL), and extracted with ether (100 mL×2). The combined organics are washed successively with saturated ammonium chloride and saturated brine, dried (Na 2 SO 4 ), filtered, and concentrated. The concentrate is chromatographed (first with 5% ethyl acetate in hexane and then with 10% triethylamine in hexane) to give 10.4 g of the title compound (compound 1, Table 1) as a fluorescent yellow foam (87%) 1 H nmr (400 MHz, CDCl 3 ) d 0.90 (t, 6 H), 1.6 (br, 4 H), 2.02 (s, 6 H), 2.37 (s, 3 H), 2.62 (s, 3 H), 3.2 (br, 4 H), 6.52 (t, 1 H), 6.73 (s, 1 H), 6.89 (t, 1 H), 7.00 (s, 2 H), 7.06 (d, 1 H), 8.98 (d, 1 H). [0092] The following compounds are prepared essentially according to the procedures set forth above in Example 1. EXAMPLE 2 [0093] [0093] 4 -(N-Cyclopropanemethyl)propylamino-2-methyl-10-(2,4,6-trimethyl-phenyl)pyrido[2,3-b]indolizine (Compound 2; Table 1) EXAMPLE 3 [0094] [0094] 4 -(1-Morpholino)-2-methyl-10-(2,4,6-trimethyl-phenyl)pyrido[2,3-b]indolizine (Compound 3; Table 1) EXAMPLE 4 [0095] [0095] 4 -(N,N-Bis(2-methoxyethyl)amino)-2-methyl-10-(2,4,6-trimethyl-phenyl)pyrido[2,3-b]indolizine (Compound 4; Table 1) EXAMPLE 5 [0096] A. 4-Hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyrimido[4,5-b]indolizine [0097] A solution of 2-amino-3-cyano-1-(2,4,6-trimethylphenyl)indolizine (220 mg) in an acetic anhydride (0.5 mL)—acetic acid (2 mL) mixture is heated at 100° C. for 1 hour. The mixture is cooled to room temperature and concentrated in vacuo. The residue is then heated in 85% phosphoric acid (5 mL) at 100° C. for 1.5 hours, allowed to cool to room temperature, diluted with water, and neutralized to pH 7 by adding aqueous ammonium hydroxide. The resulting yellow suspension is extracted twice with dichloromethane and the combined extracts are dried (Na 2 SO 4 ), filtered, concentrated, and chromatographed (50% ethyl acetate in hexane to 10% methanol in ethyl acetate) to give 120 mg of the title compound as a yellow solid. [0098] B. 4-Chloro-2-methyl-10-(2,4,6-trimethylphenyl)pyrimido[4,5-b]indolizine [0099] A solution of 4-hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyrimido-[4,5-b]indolizine (120 mg) in phosphorus oxychloride (2 mL) is heated at 100° C. for 2 hours, cooled to room temperature, and concentrated in vacuo. The residue is partitioned into ice water and dichloromethane. The aqueous phase is separated and extracted twice with dichloromethane. The combined organic extracts are washed with a saturated sodium bicarbonate solution and subsequently dried (Na 2 SO 4 ), filtered, and concentrated in vacuo. The resulting dark residue is chromatographed on silica gel (10% to 20% ethyl acetate in hexane) to give 54 mg of the title compound as a greenish yellow foam: 1 H nmr (400 MHz, CDCl 3 ) d 1.99 (s, 6 H), 2.38 (s, 3 H), 2.79 (s, 3 H), 6.80 (m, 1 H), 7.00 (s, 2 H), 7.19 (m, 2 H), 9.27 (d, 1 H). [0100] C. 4-(N-Benzylethylamino)-2-methyl-10-(2,4,6-trimethylphenyl)-pyrimido[4,5-b]indolizine [0101] A mixture of 4-Chloro-2-methyl-10-(2,4,6-trimethylphenyl)pyrimido-[4,5-b]indolizine (15 mg) and N-benzylethylamine (0.04 mL) in DMSO (0.4 mL) is heated to 110° C. for 2 hours. The mixture is allowed to cool, diluted with aqueous ammonium chloride, and extracted twice with 50% ethyl ether in hexane. The combined extracts are washed with saturated brine, dried (Na 2 SO 4 ), filtered, and concentrated in vacuo. Chromatography (10% to 20% ethyl acetate in hexane) gives 22 mg of the title compound (compound 5, Table 1) as a yellow oil: 1 H nmr (400 MHz, CDCl 3 ) d 1.17 (t, 3 H), 2.00 (s, 6 H), 2.38 (s, 3 H), 2.70 (s, 3 H), 3.40 (q, 2 H), 4.72 (s, 2 H), 6.68 (t, 1 H), 7.00 (s, 2 H), 7.03 (d, 1 H), 7.13 (d, 1 H), 7.29 (d, 1 H), 7.35 (t, 2 H), 7.41 (d, 2 H), 8.61 (d, 1 H). [0102] The following compounds are prepared essentially according to the procedures set forth above in Example 5. EXAMPLE 6 [0103] [0103] 4 -(N-Cyclopropanemethyl)propylamino-2-methyl-10-(2,4,6-trimethyl-phenyl)pyrimido[4,5-b]indolizine. (Compound 7) EXAMPLE 7 [0104] [0104] 4 -(N,N-Bis-(2-methoxyethyl)amino)-2-methyl-10-(2,4,6-trimethyl-phenyl)pyrimido[4,5-b]indolizine. (Compound 8) EXAMPLE 8 [0105] A. 2-Pyrazinyl-2-(2,4,6-trimethylphenyl)ethanenitrile [0106] A mixture of 2-(2,4,6-trimethylphenyl)ethanenitrile (1.6 g) and chloro-pyrazine (1.6 g) in THF (6 mL) is slowly added dropwise to an ice-cold solution of potassium t-butoxide (3.4 g) in THF (10 mL). After the addition, the mixture is further stirred at 0° C. for 30 minutes and then diluted with aqueous ammonium chloride. The resulting mixture is extracted twice with ethyl ether and the combined extracts are washed with saturated brine, dried (Na 2 SO 4 ), filtered, and concentrated in vacuo. Chromatography (20 to 33% ethyl acetate in hexane) gives 2.15 g of the title compound as a beige solid 1 H nmr (400 MHz, CDCl 3 ) d 2.30 (s, 9 H), 5.78 (s, 1 H), 6.95 (s, 2 H), 8.46 (s, 1 H), 8.54 (d, 1 H), 8.60 (d, 1 H). [0107] B. Ethyl 2-amino-1-(2,4,6-trimethylphenyl)pyrrolo[1,2-a]pyrazine-2-carboxylate [0108] To a mixture of 2-pyrazinyl-2-(2,4,6-trimethylphenyl)ethanenitrile (1.6 g) and potassium carbonate (2.8 g) suspended in DMF (10 mL) at 0° C. is added a solution of ethyl bromoacetate (1.0 mL) in DMF (2 mL) slowly dropwise over a 15-minute period. After the addition, the mixture is further stirred at 0° C. for 1 hour, diluted with aqueous ammonium chloride, acidified with HCl to a pH of about 7. The resulting precipitate is filtered and air-dried to give 2.5 g of a dark, greenish solid. The solid is redissolved in THF (10 mL) and treated with potassium t-butoxide (1.0 M solution in THF, 7.5 mL) at 0° C. After 30 minutes, the mixture is diluted with aqueous ammonium chloride and extracted twice with ethyl ether. The combined extracts are washed with saturated brine, dried (Na 2 SO 4 ), filtered, and concentrated in vacuo. Chromatography (20 to 33% ethyl acetate in hexane) gives 0.40 g of the title compound as a yellow oil: 1 H nmr (400 MHz, CDCl 3 ) d 1.48 (t, 3 H), 2.02 (s, 6 H), 2.38 (s, 3 H), 4.50 (q, 2 H), 4.6 (br, 2 H, NH 2 ), 7.01 (s, 2 H), 7.69 (d, 1 H), 8.25 (s, 1 H), 9.0 (br, 1 H). [0109] C. 4-Hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyrido-[2′,3′:4.5]pyrrolo[1,2-a]pyrazine [0110] A catalytic amount of dl-camphorsulfonic acid is added to a solution of ethyl 2-amino-1-(2,4,6-trimethylphenyl)pyrrolo[1,2-a]pyrazine-2-carboxyl-ate (0.40 g) in 2,2-dimethoxypropane (10 mL) and the mixture is heated to reflux for 30 minutes. Over this period, about 5 mL of volatiles are removed by slow distillation; the remaining material is further refluxed for another 15 minutes. The mixture is cooled to room temperature and concentrated in vacuo. The residue is dissolved in THF (6 mL), cooled to 0° C. to the cooled solution is added dropwise a 1.0 M solution of sodium bis(trimethylsilyl)amide in THF (2.5 mL). After the addition, the deep red solution is allowed to warm to room temperature and stirred for 2 additional hours before being diluted with aqueous ammonium chloride and extracted with three portions of dichloromethane. The combined organic extracts are dried (Na 2 SO 4 ), filtered, concentrated in vacuo, and triturated with hot ethyl acetate. The product, which precipitates upon cooling and dilution with ethyl ether, is filtered and air-dried (220 mg). The filtrate is concentrated in vacuo and another crystallization in minimal ethyl acetate and ether provides an additional 100 mg crop of the title compound as a light yellow solid: 1 H nmr (400 MHz, CDCl 3 ) d 2.0 (s, 6 H), 2.38 (s, 3 H), 2.40 (s, 3 H), 6.14 (s, 1 H), 7.04 (s, 2 H), 7.81 (d, 1 H), 8.2 (br, 1 H), 8.60 (s, 1 H), 8.43 (d, 1 H). [0111] D. 4-Chloro-2-methyl-10-(2,4,6-trimethylphenyl)pyrido[2′,3′:4,5]-pyrrolo[1,2-a]pyrazine [0112] A solution of 4-Hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyrido-[2′,3′:4,5]pyrrolo[1,2-a]pyrazine (220 mg) in phosphorus oxychloride (2 mL) is heated to 100° C. for 1 hour. The resulting dark tan solution is concentrated in vacuo, diluted with water, and neutralized by adding saturated sodium bicarbonate solution. The neutralized solution is extracted 3 times with dichloromethane and the combined extracts are dried (Na 2 SO 4 ), filtered, concentrated, and chromatographed on silica gel (10 to 20% ethyl acetate in hexane) to give 120 mg of the title compound as a yellow foam: 1 H nmr (400 MHz, CDCl 3 ) d 2.03 (s, 5 H), 2.38 (s, 3 H), 2.69 (s, 3 H), 7.03 (s, 2 H) 7.25 (s, 1 H), 7.66 (d, 1 H), 8.70 (s, 1 H), 9.00 (d, 1 H). [0113] E. 4-(N,N-Dipropyl)amino-2-methyl-10-(2,4,6-trimethylphenyl)-pyrido[2′,3′:4,5]pyrrolo[1,2-a]pyrazine [0114] To a solution of 4-Chloro-2-methyl-10-(2,4,6-trimethylphenyl)pyrido-[2′,3′:4,5]pyrrolo[1,2-a]pyrazine (23mg) in DMSO (0.5 mL) is added dipropylamine (0.1 mL) and the resulting mixture is heated at 130° C. for 3.5 days. The mixture is then allowed to cool to room temperature, diluted with aqueous ammonium chloride, and extracted twice with ethyl ether. The extracts are combined, washed with saturated brine, dried (Na 2 SO 4 ), filtered, concentrated in vacuo, and chromatographed (10 to 20% ethyl acetate in hexane) to give 14.3 mg of the title compound (compound 6, Table 1) as a yellow, glassy oil: 0.90 (t, 6 H), 1.6 (m, 4 H), 2.03 (s, 6 H), 2.38 (s, 3 H), 2.62 (s, 3 H), 3.2 (br, 4 H), 6.81 (s, 1 H), 7.02 (s, 2 H), 7.60 (d, 2 H), 8.6 (m, 2 H). [0115] The following compounds are prepared essentially according to the procedures set forth above in Example 8. EXAMPLE 9 [0116] [0116] 4 -(1-Morpholino)-2-methyl-10-(2,4,6-trimethylphenyl)pyrido-[2′,3′:4,5]pyrrolo[1,2-a]pyrazine. (Compound 9) EXAMPLE 10 [0117] [0117] 4 -(N,N-Bis-(2-methoxyethyl)amino)-2-methyl-10-(2,4,6-trimethyl-phenyl)pyrido-[2′,3′:4,5]pyrrolo[1,2-a]pyrazine. (Compound 10) EXAMPLE 11 [0118] The pharmaceutical utility of compounds of the invention is indicated by the following assay. [0119] Assay for CRF receptor binding activity [0120] CRF receptor binding is performed using a modified version of the assay described by Grigoriadis and De Souza (Biochemical, Pharmacological, and Autoradiographic Methods to Study Corticotropin-Releasing Factor Receptors. Methods in Neurosciences, Vol. 5, 1991). Membrane pellets containing CRF receptors are resuspended in 50 mM Tris buffer pH 7.7 containing 10 mM MgCl 2 and 2 mM EDTA and centrifuged for 10 minutes at 48000 g. Membranes are washed again and brought to a final concentration of 150 mg/ml in binding buffer (Tris buffer above with 0.1% BSA, 15 mM bacitracin and 0.01 mg/ml aprotinin.). For the binding assay, 100 ml of the membrane preparation is added to 96 well microtube plates containing 100 ml of 125I-CRF (SA 2200 Ci/mmol, final concentration of 100 pM) and 50 ml of drug. Binding is carried out at room temperature for 2 hours. Plates are then harvested on a Brandel 96 well cell harvester and filters are counted for gamma emissions on a Wallac 1205 Betaplate liquid scintillation counter. Non-specific binding is defined by 1 mM cold CRF. IC 50 values are calculated with the non-linear curve fitting program RS/1 (BBN Software Products Corp., Cambridge, Mass.). The binding affinity for the compounds of the invention, expressed as an IC 50 value, generally ranges from about 0.5 nanomolar to about 10 micromolar. [0121] The invention and the manner and process of making and using it, are now described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains, to make and use the same. It is to be understood that the foregoing describes preferred embodiments of the present invention and that modifications may be made therein without departing from the spirit or scope of the present invention as set forth in the claims. To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification.

Disclosed are compounds of the formula: wherein Ar, R 1 , R 2 , R 3 , W, X, Y, and Z are substituents as defined herein, which compounds are highly selective partial agonists or antagonists at human CRF 1 receptors and are useful in the diagnosis and treatment of treating stress related disorders such as post traumatic stress disorder (PTSD) as well as depression, headache and anxiety.

BACKGROUND OF THE INVENTION The invention relates to a drilling apparatus having spun-up outer pipes and spun-up inner pipes, which can be driven by a rotary drive and a rotary impact drive, the outer pipe being adapted for coupling at one of shank ends projecting on both sides of the rotary drive and being engageable with a striker that is mounted on the inner pipe for axial movement therewith. Drilling apparatuses of this type are used in special underground construction, in mining and earth-moving operations and in the construction industry. They are used to form holes in rocks for insertion and fastening of anchors when various rocks are used as a foundation for construction. Such drilling apparatuses have an outer pipe string and an inner pipe string, each of the outer pipes and inner pipes having threads for making up the pipe strings. When flushing fluid is caused to pass through the interior of the inner pipes from the flushing head to the core drill bit, the flushing fluid filled with cuttings is removed to the ground surface through the space defined between the outer pipes and the inner pipes. Normally, the inner pipe is driven by a rotary impact drive, and the outer pipe is driven by a rotary drive only. This can be a problem, especially in dealing with hard rock. Accordingly, as described in DE-PS 35 03 893, the rotary impact drive for the inner string is also used to act upon the rear end of the outer string. For that purpose, the inner string has an annular shoulder for the impact engagement with the outer string. The impact mechanism can be pulled back axially with the ring shoulder, whereby the drilling apparatus can work with the outer pipes being driven for rotation only. To resolve this problem, the design according to DE-PS 35 03 893 involves gear teeth provided at the end face of the annular shoulder and at the end of the outer pipe to form a rotary coupling between the outer pipes and the inner pipes. This gearing causes another problem relating to strong wear of the annular shoulder and also of the end portions of the outer pipe, so such drilling apparatuses cannot be used for a long time. It should be also borne in mind that the annular shoulder that comes to engage the end portion of the outer pipe is also rotated together with the inner pipes. The two rotary systems are positively interconnected through the gearing. The invention is based on the problem of providing a drilling apparatus having a design in which an outer pipe can have a rotary or a rotary percussion connected to, and driven by, the drilling apparatus. SUMMARY OF THE INVENTION This problem is resolved, according to the invention, by the fact that the shank end is provided with a compensation ring on the rotary impact side, which has the hardness that is lower than that of the material of the pipe and striker and/or corresponds to that of the end portion of the shank end and has a form and/or surfaces to compensate for the applied forces. Using an annular shoulder for the striker to engage the end portion of the shank end is known from DE-PS 35 03 893. In this particular case, a compensation ring is provided between two engageable parts, namely the end portion of the shank end and the striker, and is used for compensation between the rotating impact part and the striking impact part to avoid premature overloading of, or damage to, both the striker and the end portion. With the proper construction and material for the compensation ring, even when the compensation ring is worn, the compensation ring is still capable of transmitting the applied forces and blows. This is ensured by a particular configuration and surface, as well as the general form of the compensation ring, that does not generally require any special material of treatment regardless of whether the drilling apparatus is used for a rotary or rotary impact drive of the outer pipe. Only when, for any reason, extreme stresses occur under an overload, is it required that the compensation ring be replaced when it shows signs of damage. In a preferred embodiment of the invention, the compensation ring has, on one side, a surface corresponding to the adjacent end portion of the shank end, which is three-dimensionally curved. This ensures the alignment of the compensation ring on the one side and the shank end on the other side without any need for exact guidance of both parts. At the same time, such a compensation ring and an appropriately designed shank end ensure the central application of forces to the outer pipe in the case of the offset application of forces. This ensures reliable compensation by means of the compensation ring. It is especially preferred, according to the invention, that the compensation ring have surfaces on both sides surface corresponding to the adjacent end portions of the shank ends, which are three-dimensionally curved, and it is understood that the shank end on the one side and the striker on the other side have surfaces that are respectively curved. The compensation ring has its curved surface or surfaces on the respectively curved shank end at the respectively curved striker. As will become clear from the description, in this manner the compensation ring will always remain in an optimum position without any additional adjustment or control devices being required. The compensation ring should be preferably installed at the shank end in such a manner that the compensation ring made as a loose part remains at the shank end when the impact drive with the striker is pulled back. In order to rule out slip, tilt, and the like, it is provided, according to the invention, that the shank end has a casing supported by the rotary drive motor encloses the compensation ring. It is preferred for the sake of simplicity to provide the casing with projections that are designed to fix the compensation ring, with the striker having a respectively smaller diameter to be received within the casing in such a manner as to be in contact with the respective surface of the compensation ring during the rotary percussion operation. It should be also noted that with the rotary percussion mode for the outer pipe described herein, the inner pipe and the striker of the rotary impact drive rotate simultaneously, because the rotary impact drive is connected to the inner pipe or is made integrally therewith. To avoid damage to the smooth surfaces, which can be in contact with the drilling fluid, according to the invention, the casing has lubrication holes opposite to the curved surfaces of the compensation ring. Grease or the like can be put into these lubrication holes at regular intervals, e.g., before starting operation or on an as-needed basis so as to ensure lubrication of both surfaces of the compensation ring and the mating faces of the shank end and the striker. To remove the grease moving under pressure on both sides sliding over each other and, more specifically, to facilitate insertion of the inner pipe through the compensation ring during assembly, it is preferred that the compensation ring have a central hole of a diameter that is larger than the diameter of the inner pipe. It is preferred that this central hole have a chamfer to reduce damage caused by blows of the striker in this area. It is also preferred that the striker also have the chamfered edge in this area, and the opposite side of the central hole may also have a chamfer. To ensure guidance for the compensation ring in the casing on the one hand and to allow the compensation ring to reciprocate over the full range over the surfaces of the shank end and the striker, the outer edges of the compensation ring are rounded. In this manner, the compensation ring has rounded edges all around to ensure good support for the compensation ring between the faces of the shank end and the striker. The striker is mainly a part of the inner pipe; it is appropriately driven by the rotary impact mechanism and can transmit the impact energy to the outer pipe string. To facilitate make-and-break operations and to optimize installation, according to the invention, the striker is made as a striker sleeve that is loosely connected to the shank end of the rotary impact drive. This shank end has appropriate threads for replacement of the attached striker sleeve when required, for ensuring its intimate contact with the rotary impact drive and with the rotary drive when the outer pipe is only rotated. Quick make-and-break operations are thus made possible, especially when it is required to replace the striker sleeve for a larger or smaller striker sleeve or when a simple replacement is needed. The compensation ring is engageable with the striker sleeve to assure the optimum transfer of appropriate forces if, according to the invention, the compensation ring has the outside diameter that corresponds to, and is preferably larger than, that of a head of the striker sleeve and of the shank end. The greater diameter of the compensation ring is advantageous in the case where the compensation ring is fixed in bosses or lugs of the casing. Otherwise, the compensation ring has the same diameter. The rotary drive and the rotary impact drive are axially movable together so as to move or drive the interconnected outer and inner pipes with their respective strings into the hole. To allow for independent operation, according to the invention, the striker sleeve is axially movable together with the rotary impact drive independently of the rotary drive of the outer pipe. The rotary impact drive is thus retracted from the striker sleeve in such a manner that it can be only driven to rotate so that the outer pipe will only rotate, and the inner pipe will be driven by the rotary impact drive to assure hole formation. As the outer pipe is to be driven only through a relatively limited thickness of the ground shell, the rotary drive is used for a soft rock, and the striker sleeve can be retracted from the compensation ring and from the shank end to facilitate movement of the pipe strings. To avoid injuries to the drilling crew, the striker sleeve is dogboned and has a funnel-shaped protective cover that is fixed at the end opposite to the compensation ring and covers the casing in a spaced relation thereto in the area of the compensation ring. This protective cover is preferably made of a flexible material, e.g., of hard rubber or plastic. It covers the striker area, i.e., the area in which the striker sleeve engages the compensation ring. If the striker sleeve is to be retracted from the compensation ring, the protective cover is made “shorter” and is preferably attached to the inner pipe, or more exactly, to the striker sleeve in order to move together therewith. The striker sleeve is in contact with the compensation ring, thus engaging the outer string and the shank end, and the protective cover is sealed against a respective projection of the casing, so that mishandling by the drilling crew cannot and does not damage the apparatus. If required, e.g., for inspection of the striker sleeve, the protective cover, which is secured by means of a retainer ring to the dogboned striker sleeve, may be removed. It can be also noted that both the shape and the material of the compensation ring are such that the ring can perform its compensating function. The material is chosen in such a manner that, on the one hand, it can reliably transmit the impact of the striker sleeve to the shank end and then to the outer pipe and, on the other hand, the same shank end is protected and is not damaged by the blows. Both the form and the material are also chosen in such a manner that the blows that are transmitted in an imperfect alignment do not inflict damage upon respective parts, and the rotating striker sleeve is as if being centered by means of the compensation ring. The compensation ring can shift aside or tilt even inside of the surfaces of the compensation ring, and the shank end and striker sleeve are appropriately shaped. Generally speaking, according to the invention, if the compensation ring has hardness, as well as heat conductivity and other properties chosen so as to differ from the material of the shank end and striker sleeve, and its toughness is preferably higher, the compensation ring can perform its function. It is preferred that this material be bronze and more specifically, forged bronze. Forged bronze ensures optimum properties for the compensation ring. It can take up the forces between the striker sleeve and the shank end both in terms of the hardness and toughness without causing damage to these parts. The invention is characterized by the fact that it provides a drilling apparatus that can be used for driving the outer pipe string in both the rotary and rotary percussive mode. The rotary drive is used for driving the inner pipe string or inner pipe in the known manner, with the outer pipe being simultaneously driven by impacts. Between individual parts, namely between the striker sleeve on the one side and the end face of the shank end coupled with the outer pipe, there is provided a compensation ring that is used for compensation in every aspect, which also allows the impacts transmitted from the rotary impact drive to be transferred to the outer pipe when required. The compensation ring is also used to protect against heat, as well as excessive energy at the shank ends, especially at the end of the striker sleeve. The positive centering and the reliable transmission of forces are assured owing to a specific configuration of the compensation ring. In general, a drilling apparatus is provided that has prolonged life and that can work continuously when used for drilling in very hard rocks, with the outer pipes being driven in the rotary percussive mode continuously for a long time. Other features and advantages of the present invention will become apparent from the following detailed description of its embodiments in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general view of a drilling apparatus having a twin impact clutch, in front elevation view; FIG. 2 is a sectional view taken in the area of a compensation ring; FIG. 3 is a sectional view of the compensation ring. DETAILED DESCRIPTION A drilling apparatus 1 for two pipe strings is shown in front elevation view in FIG. 1 . An outer pipe is shown at 2 , and an inner tube having a smaller diameter is shown at 3 . While the outer pipe 2 is engaged for rotation with a rotary drive 4 , which is not described in detail here, a rotary drive motor 6 is used for driving a rotary impact driven 7 with a striker device to drive the inner pipe 3 in the rotary percussive mode. FIG. 1 shows a shank end 5 of the end of the outer pipe 2 , having twin threads 14 . The rotary drive 4 and the rotary impact drive 7 are axially movable together on a slide, which is not referenced, so that the drilling pipe strings can be driven as a whole into the rock or into a building structure. The slide is divided into two parts. The parts are connected together by means of a hydraulic cylinder for retracting the rotary impact mechanism from the rotary drive. The outer pipe 2 and the shank end 5 should be driven not only for rotation by the rotary drive 4 , but also simultaneously in the rotary percussive mode, which is required, e.g., in the case where the twin pipe string is to be driven through rock such as stone. When the rock or stone hardness requires that a striker 8 be activated in order to drive the outer pipe 2 not only for rotation by the rotary drive 4 , but also under the action of the striker 8 for percussive driving, the striker 8 is moved toward casing 9 by the hydraulic cylinder to a position in which it engages a compensation ring 10 . In this case the inner pipe string, more specifically, the inner pipe 3 will transmit the impact energy to the outer pipe 2 . This can be more clearly seen in FIG. 2 . Similarly to the rotary drive 4 , the rotary impact drive 7 has a shank end 16 or a tail pipe that is in engagement with a rotary drive motor 6 ′ and a hammer member that is not shown. A force is transmitted directly from the shank end 16 to the inner pipe 3 . FIG. 1 also shows a flushing head 13 through which flushing fluid is supplied into an inner passage 20 of the inner pipe 3 and, more specifically, to the rotating inner pipe 3 . FIG. 2 also shows the flushing head 13 that is mounted on the inner pipe 3 , and the striker 3 that is made as a striker sleeve 15 . The striker sleeve 15 acts through the compensation ring 10 upon the end portion 11 of the shank end 5 and, through it, upon the outer pipe 2 . The inner pipe 3 is connected to the striker sleeve 15 by means of threads that are not shown here. A head 17 of the striker sleeve 15 directly engages the compensation ring 10 , the rotary motion of the striker sleeve 15 is not restricted, and grease is pressed through lubrication holes 12 that are located in the area of the compensation ring 10 . The drawing also shows the inner passages 20 through which the flushing fluid is supplied toward a core drill bit that is not shown. The head 17 of the striker sleeve 15 and the end portion of a casing 19 with the appropriately positioned compensation ring 10 are enclosed in, and protected by, a protective cover 18 that is attached to the end 19 of the striker sleeve 15 , which is apart from the compensation ring 10 , for reciprocation with the striker sleeve 15 and for covering the compensation ring during operation in the impact mode. FIG. 3 shows a sectional view of the compensation ring 10 , wherein surfaces 21 and 22 on both sides of the compensation ring 10 are shown as planar. Actually, as mentioned in the specification, these surfaces 21 , 22 are three-dimensionally curved, among other things, to ensure self-alignment of the striker sleeve 15 in the percussive mode and to increase the surface area (contact area). A central hole 23 is greater than the outside diameter of the inner pipe 3 , which can be clearly seen in FIG. 2, to facilitate insertion of the inner pipe without the inner pipe affecting the compensation ring 10 . Outer edges 24 , 25 are rounded as can be seen in FIG. 3, and inner edge 26 can also be rounded or chamfered. The compensation ring 10 is made of the above-discussed tough material, and the surfaces 21 , 2 should be sufficiently smooth to be able to eventually assure uniform movement of the rotating striker sleeve 15 even without a lubricant. It should be understood that the respective opposite surface of the striker sleeve 15 and the respective surface of the shank end 5 are also finished smoothly. All the above-described features of the invention illustrated in the drawings can be used, according to the invention, singly or in combination.

A drilling apparatus 1 having a twin-impact system can work continuously with a shank end 5 is provided with a compensation ring 10 on the rotary impact side, which has a material with hardness that is lower than that of the material of the pipe and striker 8 and/or corresponding to the adjacent end portion 11 of the shank end 5 and has a shape and/or surfaces 21, 22 to compensate for the applied forces.

RELATED APPLICATIONS [0001] This application is a U.S. national phase application of PCT Application Serial No. PCT/US2015/38543, filed Jun. 30, 2015, which claims the benefit of U.S. Provisional Application Ser. No. 62/023,419, filed Jul. 11, 2014, the entire contents of which are hereby incorporated by reference. BACKGROUND [0002] Shaving systems often consist of a handle and a cartridge in which one or more blades are mounted in a plastic housing. In some cases, the blades are held in place in the housing by a pair of metallic clips, mounted at opposite ends of the length of the blades. [0003] Most modern razor cartridges include one to five razor blades disposed between a guard and a cap. The cutting edge of each razor blade is positioned adjacent a plane that tangentially intersects the contact surfaces of the guard and the cap. This plane, referred to as the “contact plane,” represents the theoretical position of the surface being shaved. The position of a razor blade's cutting edge relative to the contact plane is described in terms of the “exposure” of the cutting edge. A cutting edge with “positive exposure” is one that extends through the contact plane and into the area normally occupied by the object being shaved. A cutting edge with “negative exposure” is one that is positioned below the plane and therefore does not intersect the contact plane. A cutting edge with “neutral exposure” is one that is contiguous with the contact plane. Generally, positioning the cutting edge of a blade at a positive exposure has been found to improve closeness, but potentially also increases the chance of skin irritation. On the other hand, neutral or negative blade exposure tends to reduce the likelihood of irritation, but also tends to decrease the closeness of the shave. [0004] The overall blade geometry of the cartridge, including blade exposure and other factors such as blade span, affects the comfort and closeness of the shave obtained with the razor, as well as the likelihood of nicks and cuts during shaving. As will be discussed further below, comfort and closeness is also impacted by “skin management,” i.e., the way in which the skin bulge contacted by the blade edges is affected by other elements of the razor, including the guard that is provided at the leading edge of most razor cartridges. SUMMARY [0005] In general, the present disclosure pertains to razor cartridges (also known as blade units), and to shaving assemblies that include such cartridges. [0006] In one aspect, the invention features a razor cartridge comprising (a) a frame defining a base, said frame having an opening defined in part by a composite guard having a leading guard surface and a cap having a trailing cap surface, said leading guard surface and said trailing cap surface cooperating to define a contact plane tangential thereto and extending across said opening; and (b) at least three razor blades attached to said base, said razor blades being fixedly spaced. The cutting edge of the razor blade closest to the leading guard surface has a cutting edge exposure relative to said contact plane that is positive, and the cutting edge exposures of the other razor blades become less positive from said leading guard surface to said cap. [0007] By “composite guard,” we mean a guard that includes a flexible elastomeric portion and a rigid or semi-rigid supporting portion that is closer to the blades than the flexible elastomeric portion and that is the last skin-engaging surface prior to the blades. [0008] Some implementations include one or more of the following features. [0009] The razor cartridge may include four or more blades, e.g., five blades. [0010] The composite guard may include an elastomeric guard bar having a skin contacting surface, and a rigid guard bar support defining said leading guard surface, wherein the rigid guard bar support is proximal to the cutting edge of the razor blade closest to the leading guard surface. In some cases, the skin contacting surface of the elastomeric guard bar is higher than an uppermost surface of the rigid guard bar support, e.g., by about 0.05 to 0.5 mm, preferably by about 0.2 to 0.3 mm. [0011] In some implementations, the cartridge has a pivot point that is closer to the trailing cap surface than to the leading guard surface. The pivot point may be below a lowermost portion of the blades. [0012] In preferred implementations, the blades are spaced relatively close together. At least two of the blades may have an inter-blade span that is less than about 0.9 mm, e.g., from about 0.75 to 0.85 mm. The primary span, i.e., the distance between a leading edge of the leading guard surface and the cutting edge closest to the leading guard surface may be from about 0.3 to 0.75 mm, e.g., from about 0.35 to 0.45 mm. [0013] In some implementations, the blades are bent blades, and the blades are fixedly supported within the frame such that the blades are not intended to move relative to the frame during shaving. [0014] In another aspect, the invention features a razor cartridge comprising (a) a frame defining a base, said frame having an opening defined in part by a guard having a leading guard surface and a cap having a trailing cap surface, said leading guard surface and said trailing cap surface cooperating to define a contact plane tangential thereto and extending across said opening; and (b) at least three razor blades attached to said base, said razor blades being fixedly spaced. The cutting edge of the razor blade closest to the leading guard surface has a cutting edge exposure relative to said contact plane that is positive, the cutting edge exposure of the cutting edges of the other razor blades become less positive from said leading guard surface to said cap, and one or more of the blades has a cutting edge exposure that is negative or neutral. [0015] In some implementations, razor cartridges according to this aspect of the invention may include any one or more of the features disclosed above. [0016] In other aspects, the invention features methods of contacting the skin with the razor cartridges described herein, and methods of manufacturing razor cartridges. DESCRIPTION OF THE DRAWINGS [0017] FIG. 1 is a perspective view of a razor cartridge according to one implementation. [0018] FIG. 2 is a cross sectional view of the razor cartridge shown in FIG. 1 , taken along line 2 - 2 in FIG. 4 . [0019] FIG. 3 is a cut-away perspective view of the razor cartridge shown in FIG. 1 , cut along line 3 - 3 in FIG. 1 . [0020] FIG. 4 is a rear plan view of the razor cartridge. [0021] FIG. 5 is a diagrammatic cross-sectional view of a portion of the razor cartridge, showing features of the blade geometry of the cartridge. [0022] FIG. 5A is an enlarged diagrammatic view showing details of the blade geometry. [0023] FIG. 6 is a cross-sectional view of the cartridge with the cartridge pivot point indicated. DETAILED DESCRIPTION [0024] FIG. 1 shows a razor cartridge 10 that includes a housing 12 , a cap 14 , a composite guard 16 , and a plurality of blades 18 disposed between the cap and guard. In some implementations, the cap 14 may be formed of a rigid plastic. The housing 12 defines a generally rectangular frame surrounding an open area in which the blades are positioned. As shown in FIGS. 2 and 5 , the housing also defines a rigid guard bar support 21 having a leading guard surface 11 ( FIG. 5 ), and a rigid cap support 23 having a trailing cap surface 13 ( FIG. 5 .) As will be discussed in detail below, the razor cartridge 10 includes a number of features that contribute to enhanced skin management and thus to a close, comfortable shave. [0025] Referring to FIGS. 2-3 , the composite guard 16 includes an elastomeric portion having a plurality of fins 17 and an elastomeric guard bar 19 , and a rigid portion provided by the rigid guard bar support 21 . The elastomeric guard bar 19 is supported by the rigid guard bar support 21 , which prevents excessive deflection of the elastomeric guard bar as the elastomeric guard bar stretches the user's skin during shaving. The elastomeric guard bar uniformly stretches, tensions, straightens and flattens the skin prior to the skin contacting the rigid guard bar support. The rigid guard bar support 21 is the last point of skin contact before the blades. Such composite guards are described in further detail in U.S. application Ser. No. 61/983,790, filed Apr. 24, 2014, the full disclosure of which is incorporated herein by reference. [0026] The elastomeric guard bar 19 is higher than the guard bar support 21 , and is also higher than the cutting edge of the blade that is closest to the guard bar support (hereafter referred to as the “primary blade.”) In some preferred implementations, the skin contacting surface of the elastomeric guard bar is higher than an uppermost surface of the rigid guard bar support by at least 0.05 mm, e.g., from about 0.05 to 0.5 mm or in some cases from about 0.2 to 0.3 mm higher. This height allows the elastomeric guard bar to stretch the skin prior to the skin contacting the primary blade, thereby managing the skin bulge and reducing the tendency of the primary blade to nick the skin. The rigid guard bar support then supports and manages the skin again prior to contact between the skin and the primary blade, setting the skin up for blade contact. [0027] Blades 18 are positioned relative to each other and relative to the cutting plane discussed in the Background section above (plane P c in FIG. 5A , defined herein between the leading surface 11 of the guard bar support 21 and the trailing surface 13 of the cap support 23 ) by blade positioning elements 22 ( FIG. 2 ). As shown in FIG. 4 , the blade positioning elements are positioned at intervals along the length of the blades, providing open areas 20 between the blade positioning elements for rinse through of hair and debris. Together, the blade positioning elements provide a base for the blades. [0028] Referring to FIG. 2 , each of the blade positioning elements 22 defines a plurality of slots 24 which hold the blades in predefined positions relative to each other, while the curved upper surfaces 26 of the positioning elements 22 support the lower surfaces of the upper portions of the blades to maintain the blades in a predefined shaving geometry. The blades are preferably fixed blades, i.e., they are positioned by the positioning elements 22 in a manner that is intended to substantially prevent deflection of the blades during shaving. [0029] Referring to FIG. 1 , a pair of clips 28 , disposed just inboard of the short ends of the housing 12 , retain the blades securely in the housing. The clips may be arranged, for example, as disclosed in U.S. application Ser. No. 61/885,906, filed Oct. 2, 2013, the full disclosure of which is incorporated herein by reference. [0030] Blades 18 are preferably bent blades, as shown in FIGS. 2-3 and 5-6 . By “bent blades,” we mean blades that include an elongated blade portion that tapers to a cutting edge, an elongated base portion that is integral with the blade portion, and a bent portion, intermediate the blade portion and the base portion. Such blades are described, for example, in U.S. Pat. No. 5,010,646, the full disclosure of which is incorporated herein by reference. [0031] It is also preferred that the blades be fixed blades, rather than “sprung” blades (e.g., blades of the type described in U.S. Pat. No. 4,270,268.) Thus, the blades are positioned by their placement in the slots of the blade positioning elements and held in place by the clips such that their position relative to the housing does not change during shaving. [0032] The distance between the cutting edges of adjacent blades, referred to herein as inter-blade span (S i , FIG. 5 ), is selected to enhance skin management, by managing the skin bulge as the cutting surface moves across the user's skin. The distance between each of the blade edges is preferably less than 0.9 mm, e.g., from about 0.75 to 0.85 mm. [0033] The primary span (S p , FIG. 5 ), i.e., the distance from the leading edge of the guard to the cutting edge of the primary blade, is also important to effective skin management. This distance, along with the relative heights of the elastomeric guard bar, guard bar support, and cutting edge of the primary blade, affects the balance between shaving comfort and closeness. The primary span is preferably from about 0.3 to 0.75 mm, more preferably from about 0.35 to 0.45 mm. Too small a distance tends to impact shaving closeness detrimentally, while too large a distance could cause the skin bulge to be too large, tending to result in nicking or skin irritation. [0034] The skin management provided by the features discussed above contributes to the ability to have a primary blade with a positive exposure relative to the cutting plane without compromising user comfort. Preferably, the primary blade is positive by at least 0.02 mm, preferably by at least 0.025, e.g., at least 0.035 mm, and in some cases by about 0.04 mm or more. In some implementations, the primary blade could be positive by as much as 0.1 mm. As shown in FIG. 5A , the remaining blades have a less positive exposure as the blades become closer to the cap, with the blades closest to the cap having a negative exposure. In some cases, the second blade (counting from the primary blade towards the cap) has a neutral or slightly positive exposure, the third blade has a neutral exposure, and the fourth and fifth blades have a negative exposure. [0035] The cartridge is designed to pivot in a manner that takes advantage of this blade exposure arrangement by causing shaving forces to be relatively evenly distributed over the blades during shaving, with somewhat less force being applied to the primary blade. By applying more force to the negative and neutral blades and less to the primary blade, shaving comfort is enhanced without deleteriously affecting closeness. [0036] Referring to FIG. 6 , in preferred implementations the pivot axis P of the cartridge is positioned closer to the cap trailing edge than to the guard leading edge, measured along the x axis, and below the bases of the blades, measured along the y axis. This arrangement, known as “rear pivoting,” reduces the likelihood of nicking due to the positive exposure of the primary blade, especially during clean up strokes, and spreads blade wear relatively evenly between the blades. The rear pivoting arrangement also helps to prevent nicking by the positively exposed primary blade. [0037] The pivot axis is also positioned below a lowermost portion of the base portions of the blades. This positioning allows the cartridge to have a small footprint. [0038] The housing 12 can be made of any suitable material including, for example, amorphous blends of polyphenylene ether and polystyrene, e.g., polymers sold under the tradename NORYL resins, acrylonitrile butadiene styrene (ABS), polystyrene, polyethylene terephthalate (PET or PETE), high density (HD) PETE, thermoplastic polymer, polypropylene, oriented polypropylene, polyurethane, polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyester, high-gloss polyester, nylon, or any combination thereof. The cap 14 is preferably formed of the same material as the housing. [0039] The clips can be made of metals (preferably Aluminum, aluminum alloys) or other malleable material. [0040] The guard, including the elastomeric portion of the composite guard, may be made of any suitable materials, e.g., as described in U.S. application Ser. No. 61/983,790, filed Apr. 24, 2014. [0041] A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. [0042] For example, the cartridge may have more or fewer than five blades. Moreover, the exposure of the blades other than the primary blade may in some implementations be different from the progression described above. [0043] As another example, while a composite guard bar consisting of an elastomeric guard bar and a rigid guard bar support has been described above, other types of guard bars may be used. [0044] Moreover, while a generally rectangular cartridge is shown in the Figures, other shapes can be used, e.g., oval. [0045] Accordingly, other embodiments are within the scope of the following claims.

Replaceable shaving assemblies are disclosed that include a razor cartridge having a blade geometry that is designed to provide a close, comfortable shave. Shaving systems including such shaving assemblies are also disclosed, as are methods of using such shaving systems and methods of manufacturing these cartridges.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of an improved foam of a thermosettable phenol-formaldehyde condensate. More particularly, it relates to an improved phenolic foam useful for insulating metallic conduits and other substrates which has a high resistance to combustion, is anti-punking, and is of low corrosion to the metallic substrate. 2. Description of the Prior Art With the advent of reinforced plastic casting, laminating and molding technology, the use of plastic materials has grown to include structural and decorative applications in buildings, aircraft, vehicles and other structures. The majority of the economically useful plastics are, however, combustible and the flammability of such materials is a prime consideration in determining their degree of usefulness in a given application. Phenolic resin foams are noted for their low flammability and their ability to resist a direct application of flame. These materials do not melt or soften unless such flame is accompanied by copious amounts of air or oxygen. It has been known to prepare such foams from aqueous phenol-formaldehyde resins using an acid catalyst. The reaction is exothermic, which converts the water present to steam. The liquid resin is gradually converted into an infusible solid, entrapping such steam which, in turn, gives the cellular structure of the foam. In place of, or in conjunction with water, other volatiles may also be used to aid in foam formation. However, it is a well-recognized problem that the phenolic foams produced in this manner experience severe punking after being exposed to flame. Punking, as is well known, is the phenomenon of continuing to glow and combust without a visible flame even after the combustion source has been removed. Such punking is a serious limitation in the use of these materials as thermal insulation, especially in inhabited structures. The production of non-punking foams has generally been disclosed in U.S. Pat. No. 3,298,973. In that patent, phenol-aldehyde resole resins having a viscosity of from about 200 to about 300,000 centipoises at 25° C. are reacted with a catalyst that is a mixture of at least two acidic reagents. The catalyst is a solid mixture of boric acid or its anhydride and an organic hydroxy acid in which the hydroxy group is on a carbon atom not more than one carbon atom removed from a carboxy group. Because of the viscosity of the resole resin, this process is disadvantageously carried out by a slow and tedious batch procedure. Further, even when using large amounts of boron oxides in these foams, punking is not completely controlled. Other boron-containing, non-punking phenol-formaldehyde foams are described in U.S. Pat. No. 3,663,489 disclosing boron-containing compounds formed by reacting boric acid or boric oxide with glyoxal and its derivatives, and U.S. Pat. No. 3,740,358 disclosing boron-containing compositions utilizing boric acid or boric oxide in conjunction with hydrochloric acid. British Pat. No. 824,251 sets forth a method for the production of phenol-aldehyde castings free from voids by using as catalysts boric acid or boric oxide with hydroxy organic compounds. The catalysts described in this latter patent are not capable of producing foams, and there is no indication that the materials produced have any improved fire-retardant or heat-resistant properties. The latter two United States patents, while producing non-punking foams, result in foamed materials that are extremely high in acidity and, when in contact with metallic substrates such as metallic pipes, girders, panels, tubes, and the like, cause severe corrosion. It is apparent, therefore, that there is a need in industry to provide heat-resistant phenolic foams which have a high degree of anti-punking character and which are also non-corrosive to metallic substrates over or on which such may be applied. SUMMARY OF THE INVENTION It is accordingly one object of the present invention to provide a new heat-resistant phenolic foam which will not burn or punk when exposed to direct flame. Another object of the present invention is to provide a novel phenolic foam containing compounds of boron which give a foam of superior resistance to combustion and punking when exposed to flame. Yet another object in accordance with the present invention is to provide a novel heat-resistant phenolic foam composition containing sodium tetraborate which gives a foam of superior resistance to combustion and punking and additionally creates a foam that is non-corrosive when used on or over metallic substrates. These and other advantages of the present invention will become apparent from the following detailed description and examples. DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with the objects, it has been discovered that phenolic foams with high flame and heat resistance and low corrosivity can be made by adding to a phenolic resole resin a boron-containing compound. The boron-containing compound is a sodium oxide/boron oxide composition commonly termed anhydrous borax, which is the product resulting from the substantially complete dehydration of normal borax. It is chemically equivalent to sodium tetraborate of the formula Na 2 B 4 O 7 . It has been found useful to employ sodium tetraborate in its completely anhydrous condition although the completely hydrated, more common form Na 2 B 4 O 7 .10H 2 O will also provide anti-punking foams of low corrosivity. Preferably, sodium tetraborate containing 0.3% water (on analysis) is used in accordance with the present invention, e.g. equivalent to a completely anhydrous sodium tetraborate of 99.7%. Various organic and/or inorganic impurities other than water may also be present in anhydrous sodium tetraborate, but such should not cause an undue influence on the catalysis of the thermosetting phenol-formaldehyde resole resin, e.g. act as a negative catalyst. Particle size of the anhydrous sodium tetraborate is also an important factor in the formation of an acceptable foam in accordance with the present invention. If the anhydrous sodium tetraborate is too small in particle size, such will inhibit the acid catalyst, causing slow or no foaming. Too large a particle size of the tetraborate causes ruptures in the blown foam cell walls and rough textures on the resulting foam. An anhydrous sodium borate particle size of 12-200 mesh (U.S. standard sieve number) is acceptable herein. A mesh size of 12-60 mesh is preferred. The phenol-aldehyde condensation products employed in this invention are not narrowly critical and are well known in the art of phenol foams. They are commonly called one-step resins or "resole resins", being the condensation product of a monohydric phenol with an aldehyde. They are generally produced, for instance, by condensing one mole of a phenol with about one to three moles of an aldehyde in an alkaline medium and subsequently distilling the water present in vacuum so as to obtain a liquid having a solids content of 60% to 99%, preferably 70% to 97% by weight. Any of the well-known conventional alkaline catalysts suitable for promoting the reaction of phenols and aldehydes to give resoles may be used. Examples of such catalysts are sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide, calcium oxide, sodium carbonate, and sodium bicarbonate. It will be appreciated that any of the alkali or alkaline earth metal oxides, hydroxides, carbonates and bicarbonates other than those mentioned above may also be employed. Preferred are the resins of phenol per se and formaldehyde, although other phenols such as metacresol, metaxylenol and the like can also be employed, as can mixtures of phenol and the cresols. Similarly, formaldehyde can be replaced by other aldehydes or compounds that liberate aldehydes such as paraformaldehyde, formalin and the like. As disclosed above, the liquid resole resins are alkaline catalyzed condensates which are carried to only a mild state of resinification so that they are normally liquid and generally water soluble. These are more often referred to in the art as "A" stage resins, the "C" stage resins being typical of the fully cured thermoset materials. The foamable resole resin of the present invention incorporates a surfactant to reduce the surface tension of the resin during foaming, thereby aiding in the stabilization of the growing cells. The amount of surfactant normally employed ranges from about 0.5% to about 10% by weight of the resole resin, preferably 3% to 5% is used. Typical of surface active agents that can be employed in the practice of the present invention include any of the non-ionic types such as the polyethers and the polyalcohols, including the condensation products of alkaline oxides such as ethylene oxides and propylene oxides with alkyl phenols, fatty acids, alkyl silanes and silicones and like materials. These are exemplified by such products as octadecyl phenol-ethylene oxide, polyoxyethylene dodecyl phenol, polyoxyethylene glycolates and similar polyoxyethylated fatty acids and vegetable oils. Preferred are the polyoxyethylated fatty acid esters of polyoxyethylene sorbitan such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan tristearate, polyoxypropylene sorbitan monolaurate, and polyoxyethylene sorbitan monopalmitate. Similarly useful are the siloxane-oxyalkylene block copolymers such as those containing a Si--C linkage between the siloxane and the oxyalkylene moieties. Quaternary ammonium compounds are also useful in the present invention such as dimethylbenzyl ammonium chloride and diisobutylphenoxyethoxyethyl dimethylbenzyl ammonium chloride. With regard to the blowing agents that may be used, any of the halogenated alkanes, or any inert volatile agent which will be volatile from about 70° F. to 220° F. at atmospheric pressure, are useful herein. As typical examples of such, hydrocarbons, oxyhydrocarbons, or halohydrocarbons such as alkyl ethers, ketones, lower alkanes and halogenated alkanes, as for example, pentane, hexane, diethylether, diisopropyl ether, acetone, dichloromethane, dichloroethane, and the like, are useful. Most of these agents provide open cell foams. Closed cell foams can be provided with the halogenated alkanes, such as trichlorofluoromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,1,2,2-tetrachloro-2,2,-difluoroethane, 1,1,1,2-tetrachloro-2,2-difluoroethane and the like. Other blowing agents with the 70°-220° F. boiling point can be used alone or in combination. A mixture of any such blowing agents can be employed in which each is designed to volatilize at different temperatures so as to give a volatilization throughout the entire exothermic curing reaction. The amount of foaming agent is not narrowly critical. Amounts of from 1 to 20 parts per 100 parts by weight of resole are most desirable, provided that the foamable composition is of viscosity above about 200 centipoises. Some of these foaming agents dilute the resole resin so as to depress the viscosity significantly and cannot be used in large amounts. However, and because of the unusual solubility phenomenon of the fluorocarbons, these can be employed in much greater amounts. These blowing agents are preferred and such are preferably employed in about 5 to 12 parts per 100 parts resin. Acidic curing agents are useful in accordance with the present invention in forming the foamable resole resin compositions. The acidic curing agent typically used in this process may be any strong acid compound which is conventionally used in curing phenolic foams. These are Lewis acids, hydrochloric acids, sulfuric acids, nitric acids, phosphoric acids, including pyrophosphoric acids, and polyphosphonic and, hydrobromic acids, hydroiodic acids, trichloroacetic acids, and sulfonic acids. The latter term is intended to include organic sulfonic acids such as phenol sulfonic acid, chlorosulfonic acid, mixed alkane sulfonic acid, 1-naphthol-8-sulfonic acid, resorcinol sulfonic acid, and the like. All such acids are used in aqueous solution. Especially preferred is a mixture of 60 parts of toluene sulfonic acid admixed with 20 parts solution of sulfuric acid, the balance (20 parts) being water. The acid catalyst is used in an amount ranging from 2% to about 20% by weight and preferably about 8% to 12% by weight of resin. It is to be understood that in the foamed resins of this invention, there may be present other ingredients so as to impart other desirable properties. These ingredients include plasticizers, metal salts, pigments, dyes, fillers, stabilizers, neutralizers, flame proofers, fiberglass, asbestos, silica, solid nucleating agents, and like additives without departing from this invention. In fact, certain beneficial properties result from many of such additives. For example, when using mineral oil as a plasticizer, it is advantageous to blend the anhydrous sodium tetraborate with this plasticizer and then to mix the resulting slurry with the resole and the acid catalyst, thus preventing atmospheric moisture from diminishing the ability of the anhydrous sodium tetraborate to absorb water from the resole reaction mixture. Mineral oil or other related plasticizers are effective in this composition from 0 to 50 parts per 100 parts resin, 4 through 8 are preferable. Metal salts are also useful ingredients in the foamed formulations, the most preferable one being anhydrous boric acid which can combine with water in the reacting mass and enhance the properties of the final foam. These are used in 1-15 parts per hundred parts of resole resin. In order to prepare the foamed phenol-formaldehyde composition having the desired properties of fire retardancy, anti-punking and low metallic corrosivity, the starting "A" stage resole resin should have a water content not greater than 25%. Although higher percentages of water can be present in the reacting mass, such higher percentages require additional anhydrous sodium tetraborate to be effective in giving the final product a low water content. An anhydrous sodium tetraborate content of greater than 25 parts per hundred parts of resole, for example, necessitates greater amounts of catalyst so as to complete the foaming reaction. It also causes the density and the strength of the final foam to be diminished. Concentrations of less than 1 part per hundred parts resole do not give any significant effect in anti-punking ability. In addition to controlling the amount of residual water in the final foam, the anhydrous sodium tetraborate serves to act as a catalyst in the foaming and curing of the phenol-aldehyde resole as a result of the heat generated from forming the decahydrate water reaction product. Further, both the hydrated reaction product and any unhydrated or partially hydrated sodium tetraborate provide sufficient alkalinity in the final foam so as to effectively neutralize any of the above-disclosed curing catalysts. It should be appreciated that the anhydrous sodium tetraborate particle size is particularly responsible for the slow rate of neutralization of the catalyst, such neutralization occurring effectively after the foam has been expanded and cured. Additionally, the boric acid formed from such neutralization serves to enhance the fire retardant properties of the foam. The process of the present invention is carried out by blending the components in a high intensity mixer. The individual components of the foamable resole resin mentioned above are delivered to the mixer by metering lines and mixed therein with sodium tetraborate anhydrate. To reduce the number of metering lines, some of the components can be premixed as earlier mentioned. After mixing the liquid phenol-formaldehyde resole, acid catalyst, and blowing agents, the anhydrous sodium tetraborate and optionally, plasticizer and anhydrous boric acid are added. The mixture may be deposited, for example, on a mandrel to be foamed and formed into a suitable pipe insulation. It may also be deposited onto a carrier sheet where, after foaming, a board-type or slab insulator is formed. The following examples and tests are presented to illustrate the preferred embodiments of this invention, but it is to be understood that they do not represent any limitations thereto. The phenol-aldehyde resole resin especially used in the following examples, hereafter disclosed in the examples and tables as "resole", was made by the following procedure. EXAMPLE 1 280 parts by weight of phenol are condensed with 450 parts of a 30 percent aqueous formaldehyde solution with the addition of 1.430 parts of sodium hydroxide in aqueous solution at 100° C. for 70 minutes. The reaction mixture obtained is then vacuum distilled down to a soild resin content of 72 to 78 weight percent. The resin thus made has at 20° C. a viscosity of 4000 to 7000 centipoises (Brookfield). The foam formulation made in accordance with the present invention and disclosed in the below table are formed from the above-disclosed resole resin and, additionally, from two commercially available resole resins. __________________________________________________________________________ Examples 2-10Ingredient II III IV V VI VII VIII IX X__________________________________________________________________________Resole.sup.a 100.sup.a 100.sup.a 100.sup.a 100.sup.g 100.sup.g 100.sup.g 100.sup.h 100.sup.h 100.sup.hSurfactant.sup.b 2 2 2 5 5 5 2 2 2Fluorotrichloromethane 15 15 15 10 10 10 15 15 15Catalyst mixture.sup.c 15 15 15 10 10 10 10 10 10Boric acid anhydride -- -- -- 6 6 6 -- -- --Anhydrous sodium tetraborate -- 7.5 10 -- 5 7.5 -- 5 10Plasticizer.sup.d -- -- -- 6 6 6 -- -- --Density, lbs./ft..sup.3 1.4 1.7 1.8 1.8 2.2 2.5 1.9 2.0 2.2Punk.sup. e Yes No No No No No Yes No NoFoam Collapse No No No No No No No No NopH 2 5 7 1.5 6.5 8.0 1-2 5.0 7.5Corrosion.sup.f 5-6 -- 2 5-6 -- 2 5-6 -- 2__________________________________________________________________________ .sup.a Reichold Chemical phenol-formaldehyde Plyophen DR-391; viscosity (25° C.) 3000-5000 cps; 78-82% solids; 1.23-1.25 specific gravity .sup.b Tween 60 (the polyoxyalkylene derivative of sorbitan monostearate) .sup.c 60-20-20 toluene sulfonic acid-sulfuric acid-water .sup.d Mineral oil .sup.e As outlined in Quarles, U.S. 3,298,973, Column 2, lines 36-51, tes time 1 minute minimum .sup.f Estimated on a scale of 1 to 10 (1 no corrosion) when the foam was adhered to a substrate of galvanized steel, copper and soft iron and removed for examination of substrate after 2 weeks at 30° F. and 6 months at 180° F. (average value). Note: Fiberglass insulation (Industry Standard) gives a corrosion value of 1-1.5. .sup.g From Example 1 .sup.h Union Carbide phenol-formaldehyde BRL-2760; viscosity (25° C.) 2350-3150 cps; 78-81% solids. All foams prepared in examples II-X of the above table and containing sodium tetraborate demonstrated a flame spread of under 25, and a smoke density index of 50 or less in accord with ASTM E-84 Tunnel Test, as set forth in "Standard Method of Test for Surface Burning Characteristics of Building Materials," both as to equipment and test procedure. This test procedure is identical in all respects to UL-723, ANSI No. 2.5, NFPA No. 255 and UBC No. 42-1. The test results covered two parameters: flame spread classification and smoke density during a 10-minute fire exposure period. Asbestos-cement board and red oak flooring are used as comparative standards and their responses are assigned arbitrary values of 0 and 100, respectively. The performance of each material is evaluated in relation to the performance of asbestos-cement board and red oak flooring under similar fire exposure. Various modifications and changes may be made herein without departing from the spirit and scope of the present invention.

A phenolic foam that is non-corrosive to metallic substrates over which it is applied is disclosed herein. The foam is prepared by hardening an intimate mixture of a conventional foamable phenolic resole resin containing a blowing agent, a hardener and a surface active agent, and sodium tetraborate.

This application is a continuation in part of Ser. No. 09/057,659 filing date Apr. 4, 1998. BACKGROUND OF INVENTION The prison population in the U.S. is now approaching the 2 million mark. With growing prison overcrowding and resultant inmate tensions, the guards and correctional officers are increasingly exposed to stab attacks by violent criminals using a variety of home made thrusting weapons such as shanks, ice picks, knives, sharpened nails or other objects. As these attacks can inflict life-threatening wounds, many guards are now wearing protective suits designed to stop penetration of such weapons. The suits are made with multiple woven fabric layers using high performance, high tenacity yarns. A typical fabric used is woven with one of the above yarns in a density of 70 picks×70 warp ends/inch. The fabric is coated with a special resin to resist and retard penetration of an ice pick point by preventing the weave components from shifting. About 27 layers or plies of fabric are combined to provide a protective, stab resistant shield placed inside the suit. The suits are tested using the current standard, which stipulates resistance to an impact valve of 81.1 foot-pounds using a 7 inch long pick in a diameter of 0.0163 inch with a 15:1 taper and steel hardness of 42 c, as per the State of California body armor specifications. Circular weft knit fabrics have also been introduced into this field. They are made on interlock or double knit machines. These fabrics rely on heavy resin impregnation to stabilize or “freeze” the loop components in order to enhance resistance to penetration by a pick or other weapon. One of the main disadvantages of woven fabrics in offering protection from thrust or stab weapons is the relative ease with which the weft and warp threads slide on each other as the weapon's point impinges on them, pushing them aside, and leading to effective penetration. All woven structures are held together by friction existing between its components and have to use various resins to immobilize them and preserve the fabric integrity as it is impacted by a thrusting point. This makes the fabric heavy, stiff and almost impenetrable to air, leading to wearer discomfort. Circular knit fabrics, while more permeable to air than woven ones, are inherently unstable due to their residual elasticity, which must be eliminated with the application of a heavy resin coating. Furthermore, circular knit fabrics cannot be made very tight in order to produce a high thread density per unit area. This is because of their rather open loop structure. For fabrics to be truly effective in resisting point penetrations, it is essential to have a high density of yarn crossings, firmly anchored in the matrix of its structure, and without relying on friction or resin impregnation. Warp knit fabrics satisfy these requirements better than wovens or circular knits. SUMMARY OF THE INVENTION A warp knit fabric for resisting point penetration of thrusting type weapons is provided. The fabric comprises a multiplicity of thread systems made from high performance yarns with a minimum tenacity of 7 gram/denier. Each of the thread systems are produced by bar guide movement having the formulation of: 1−0/n−(n+1), wherein n is the spaces traversed by the guide bar. In one embodiment, a multi-axial warp knit fabric is produced. One thread system comprises vertical warp inlays, while a second comprises horizontal weft inlays. Preferably, a series of diagonal inlay systems are also provided. Significantly, each thread system is disposed one on the other. A loop structure is provided for holding the thread systems together. The advantages of using warp knits as a point penetration protective medium are as follows: 1) ability to engineer structures with a much higher thread density than possible with either wovens or circular knits. 2) positively locked or anchored structure members, not relying on friction or resin impregnation to preserve its integrity when impacted by a point. 3) facility to use multiple guide bars to produce very dense combination fabrics. Any warp knit structure is the result of two or more sub-structures generated by each guide bar and interknitted with each other as to render a compact, dense product. 4) the thread density may further be enhanced by a technique known as warp and weft insertion where straight lengths of threads are introduced into the structure in the horizontal and vertical directions. 5) warp knit fabrics, because of their system of loops, have a natural air permeability, superior to wovens, which have to be tightly constructed to prevent slippage of their components. The permeability of warp knits enables them to transmit perspiration vapor through the fabric and thus enhance wearing comfort. 6) warp knit fabrics are more pliable and flexible than wovens and tend to conform to the contours of the wearer's body. Other advantages will be obvious or apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is made to the following description, taken in connection with the following drawings: FIG. 1 is a schematic view of the loop configuration of the inventive fabric; FIG. 2 is a schematic view showing one embodiment of the thread systems of the invention; FIG. 3 is a more detailed schematic view showing the second embodiment of the thread system of the invention; and FIG. 3A is a cross-sectional view of the fabric depicted in FIG. 3 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As will be shown, suitably constructed warp knit fabrics will serve as protection against penetration by ice picks or other thrusting weapons. Such a design constitutes a significant improvement over existing woven, circular knit or other fabric systems. The advantages of warp knit fabrics over other protective materials are: 1) Positively locked or anchored fabric structure members which do not rely on friction or resin impregnation to preserve their integrity when impacted by a point, as is the case with woven or other knit fabrics. 2) Facility to engineer structures with a much higher thread density than possible with other type fabrics. As can be appreciated, the greater the thread density, the more effective penetration stopping powers of the structure. 3) Diverse means of generating high thread density through multiplicity of guide bars, warp and welt insertion and multiaxial technology, unavailable with other fabric forming systems. 4) The multiaxial technology involves up to five systems of threads superimposed on top of each other in a star-like configuration, which enables the fabric structure to have equal strength and penetration resistance in every direction. Both wovens and circular knits have only two systems of threads and their strength is strictly directional. 5) Warp knit fabrics have a natural air permeability, thanks to their loop structure, and superior to wovens, which must be tightly constructed to prevent slippage of their components under the impact of a penetrating point. The air permeability enhances the wearing comfort of the protective suits. 6) Warp knit fabrics are more pliable and flexible than wovens and conform better to the contours of the wearer's body. 7) Warp knits are by nature more rip-resistant than wovens, which is a distinct advantage in penetration by a knife or other bladed weapon. FIG. 1 . illustrates schematically the loop configuration in a fabric made in accordance with the invention that is used for protection against stab attacks. The drawing portrays the fabric structure as it appears on the reverse or technical side. The fabric used is a “high performance” yarn with a tenacity greater than 7 gram/denier. Suitable yarns include such fibers trademarked as DuPont's “Kevlar,” AKZO's “Twaron,” Teijin's “Technora,” all in the Para-Aramid group, Allied-Signal's “Spectra” and the DSM-Toyobo's Dyneema in the ultra high molecular weight polyethylene group and the Hoechst-Celanese's “Vectran,” a liquid crystal polymer and Toyobo's PBO fiber known as “Zylon.” The fabric, in one example, is made on a 24 gauge tricot machine using 195 denier Kevlar on both guide bars and knit as tight as the equipment would allow in order to produce maximum thread density per unit area. A Raschel machine could also knit such a fabric, but not as tight because of the peculiarities of its loop forming elements. The digital guide bar movement notation (as accepted in the industry) for this example is: Front bar: 1−0/1−2. Back bar: 4−5/1−0. The heavy black lines on the diagram show the disposition of front bar threads, while the dotted line traces the paths of the back bar threads. As shown, the black lined threads ( 1 ) of the front bar overlay those of the back bar ( 2 ) as to immobilize them in their places and thus resist penetration of an ice pick point by not allowing them to shift aside. Anyone skilled in the art can appreciate that front bar movement may be increased to extend over a longer distance, normally expressed in the needle spaces traversed by the guide bar, like 3, 4 or 5 or even more, in order to increase thread density of the structure per unit area. The general formula for front guide bar movement may be written as follows: 1−0/n−(n+1), where n is the spaces traversed by the guide bar. Each guide bar may produce such stitches as chaining (1−0, 0−1) , inlays (O−0, 2−2) and the like, warp inlays (0−0, 0−0), or combinations and permutations thereof. Horizontal weft insertion may also be used. In order to boost thread density of the fabric structure, one could use an additional guide bar or two, each bar making its own contribution and adding to the total sum of threads per unit area. Preferably, thread density must be at least 7,500 threads/sq. inch. Good ice pick penetration stopping performance may be obtained with the aid of multiaxial technology, which arrays the thread systems in a star-like configuration, as illustrated on FIG. 2 . This provides the fabric structure with equal strength and penetration resistance in every direction, which is certainly a desirable feature in a protective suit. Because of the balanced construction of the fabric, an ice pick point is restrained simultaneously by all 5 thread systems, as shown on FIG. 3 . Threads 1 are the vertical warp inlays. Threads 2 are the horizontal weft inlays. Threads 3 and 4 are the diagonal inlays. Threads 5 are formed into a loop structure, which holds the entire system of 4 inlays locked together into an integral fabric featuring considerable thread density and integrity. FIG. 3A depicts the cross-section of the structure along its vertical axis in which all the inlay threads are superimposed on top of each other and bound into a coherent bundle by the loop members of threads 5 . The inclination of threads 3 and 4 may be set in the 30 to 60 angle range. It should be pointed out here that superimposing the four thread systems in a parallel-like configuration utilizes their entire tenacity strength, unlike in woven fabrics where the threads are interlaced and crimped, which reduces their strength and imposes a harmful shearing stress when the fabric is impacted. Any warp knit machine in suitable gauge and fitted with 5 guide bars may be used to simulate the multiaxial structure through appropriate knitting technique; a system of diagonal, horizontal and vertical inlays held together in a matrix of loops may thus be produced. In some cases, it may be advantageous to apply certain post-knitting processing in order to enhance the fabric resistance to penetration by the point of a thrusting weapon. Such processing may involve the following: 1. Calendaring: This process is based on flattening the fabric between two or more steel rolls under the application of heat and pressure. The calendared fabric is substantially compacted, which boosts its resistance to penetration. 2. Lamination: The fabric may be laminated or bonded to another fabric or substrate to make it more resistant to penetration. 3. Resin Coating: The fabric may be coated or impregnated with a resin or substance which increases the coefficient of friction between the fabric and the point of a thrusting weapon as to retard its penetration through the protective garment.

A warp knit fabric for resisting point penetration of thrusting type weapons is provided. The fabric comprises a multiplicity of thread systems made from high performance yarns with a tenacity of 7 gram/denier. Each of the thread systems are produced by front bar guide movement having the formulation of: 1−0/n−(n+1), wherein n is the spaces traversed by the guide bar.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority benefit from U.S. Provisional Patent Application No. 61/282,922, filed Apr. 22, 2010, which is hereby incorporated in its entirety by reference. FIELD OF THE INVENTION [0002] The present invention relates to alleviating Internet congestion generally and to doing so by predictive traffic steering in particular. BACKGROUND OF THE INVENTION [0003] Internet congestion is known. As Internet usage continues to increase, Internet service providers (ISPs) have experienced difficulties providing enough bandwidth to maintain acceptable levels of throughput for all users on a continual basis. One obvious solution is for the ISPs to add infrastructure to increase capacity. However, such infrastructure can be expensive, and rapid growth to keep pace with demand often leads to instability. Furthermore, even if/when an ISP manages to provide sufficient bandwidth most of the time, it may be difficult to do so during peak usage times. [0004] When an ISP experiences excess demand for bandwidth, the simplest approach is to provide less than the demand. The decision regarding how and/or to whom to deny bandwidth can be either arbitrary or based on a variety of factors including, for example, user profiles, the amount requested, bandwidth quality, physical/logical topologies, etc. [0005] Another approach is to actively seek to reduce the demand by implementing an external optimization platform (EOP). An EOP optimizes resource usage for a given Internet service. An EOP may use a variety of methods to optimize the video traffic, for example, transcoding and/or transrating. Transcoding includes reformatting the media content to be downloaded via the network to a different, presumably more efficient encoding technique that requires less bandwidth. For example, a media file identified as being in MPEG2 format may be converted to H264 format which requires less bandwidth for transmission while maintaining more or less the same quality. [0006] “Transrating” entails reducing the total media content bit rate by either manipulating the frame rate, and/or reducing the number of frames without changing the encoding technique. Transrating thus effectively reduces the quality of the media stream. However as with transcoding, the extent to which it is used determines whether the reduction in quality is acceptable and/or even perceived by the end user. [0007] In a typical EOP implementation, when Internet users attempt to open a session with an Internet service, the session is terminated by an EOP proxy server. For each intercepted Internet session, the proxy server opens a second session opposite an EOP. If the EOP recognizes the session's content as the type of data which it can optimize, then it in turn opens a session opposite the originally intended server and optimizes the received content before forwarding it to the user via the proxy server. If the EOP doesn't recognize the content, the EOP proxy server then opens a session opposite the originally intended server. [0008] FIG. 1 , to which reference is now made, illustrates an exemplary implementation 50 of a typical video traffic EOP 25 . User PCs 5 attempt to connect with remote application servers (RAS) 30 via Internet 10 . However, EOP proxy server 20 intercepts the connection attempts before they can continue to servers 30 . Accordingly, PCs 5 do not connect directly with servers 30 . Instead, the associated Internet sessions (arrows 8 ) are terminated by proxy server 20 . Proxy server 20 then initiates a new session (arrows 40 ) with EOP 25 on behalf of each terminated session. [0009] In the embodiment of FIG. 1 , each PC 5 attempts to connect to a remote application server 30 . PC 5 A attempts to connect with video server 30 A; PC 5 B attempts to connect with email server 30 B; and PC 5 C attempts to connect with IM server 30 C. EOP 25 is configured to optimize video sessions. Accordingly, when EOP proxy initiates a session with EOP 25 on behalf of PC 5 A, EOP 25 recognizes the data as “relevant”, i.e. “video traffic” and interacts with video server 30 A to optimize the resulting data session. [0010] EOP 25 cannot process all the incoming session data from EOP proxy server 20 . For example, as per the embodiment of FIG. 1 , PC 5 B is attempting to connect with email server 30 B and PC 5 C is attempting to connect with IM server 30 C. Accordingly, the sessions (arrows 40 B and C) initiated by proxy server 20 on their behalf do not contain video traffic, and EOP 25 will indicate to EOP proxy server 20 that it will not process their data. After receiving such indication, EOP proxy server will initiate new sessions opposite servers 30 B and C as per the original addressing provided by PCs 5 B and C respectively. [0011] Another typical implementation of an EOP based solution replaces EOP proxy server 20 with a traffic steering utility comprising deep packet inspection (DPI) functionality. The utility uses the DPI functionality to inspect packets from PCs 5 as they connect directly with servers 30 . When session data is identified as being relevant to an EOP 25 , the traffic steering utility diverts the session to the relevant EOP 25 instead of to the originally addressed server 30 . SUMMARY OF THE INVENTION [0012] There is provided, in accordance with a preferred embodiment of the present invention, an Internet steering gateway including a deep packet inspection (DPI) utility to at least ascertain an indication of a destination remote application server (RAS) from a first packet of a data session, an RAS database to at least store an optimization profile for each of a multiplicity of the RASs, and a steering utility to steer the data session to one of at least one external optimization platform (EOP) and a RAS as per the optimization profile associated with the indication. [0013] Further, in accordance with a preferred embodiment of the present invention, the gateway also includes means to lookup an optimization profile as per the indication. [0014] Still further, in accordance with a preferred embodiment of the present invention, the optimization profile includes at least an indication if data traffic associated with the RAS is optimizable. [0015] Additionally, in accordance with a preferred embodiment of the present invention, the optimization profile includes an indication of which EOP to steer the data session to for optimization. [0016] Moreover, in accordance with a preferred embodiment of the present invention, the at least one EOP is at least two EOPs. [0017] Further, in accordance with a preferred embodiment of the present invention, the gateway also includes an EOP database to store an EOP profile and address for at least one EOP. [0018] Still further, in accordance with a preferred embodiment of the present invention, the DPI utility is configurable to inspect multiple the data packets to ascertain whether or not the data session is optimizable. [0019] Additionally, in accordance with a preferred embodiment of the present invention, the gateway also includes means for associating a the optimizable data session with a the EOP profile in order to determine an appropriate the EOP for the RAS. [0020] Moreover, in accordance with a preferred embodiment of the present invention, [0021] the gateway according to claim 1 also includes means for updating the RAS database with the RAS and an associated the optimization profile, where the associated optimization profile comprises at least an indication of a the EOP that is appropriate for customizing the data traffic associated with the RAS. [0022] Further, in accordance with a preferred embodiment of the present invention, the at least one EOP is positioned internally within the steering gateway. [0023] There is also provided, in accordance with a preferred embodiment of the present invention, a method for optimizing network service delivery, implementable on an Internet service gateway, the method including: inspecting a first packet of a data session with a deep packet inspection (DPI) utility, identifying a destination address for an RAS from the first packet, looking up the RAS in a RAS database as per the destination address, and for a RAS found in the RAS database, steering the data session in accordance with a profile associated with the RAS. [0024] Still further, in accordance with a preferred embodiment of the present invention, the steering includes: steering the data session to an EOP in accordance with the profile, where the profile indicates that the data session is optimizable by the EOP. [0025] Additionally, in accordance with a preferred embodiment of the present invention, the steering includes steering the data session to the destination address, where the profile does not indicate that the data session is optimizable by an EOP. [0026] Moreover, in accordance with a preferred embodiment of the present invention, the method also includes inspecting a multiplicity of packets from the data session with the DPI utility, determining if the data session is optimizable, and associating the RAS with an appropriate the EOP in the associated profile. [0027] Further, in accordance with a preferred embodiment of the present invention, the method also includes: adding a record to the RAS database for the RAS, where the RAS was not found by the looking up. [0028] Still further, in accordance with a preferred embodiment of the present invention, the method also includes initializing the RAS database with a list of known the RASs with their associated the profiles prior to a first operation of the inspecting by the DPI utility. BRIEF DESCRIPTION OF THE DRAWINGS [0029] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which: [0030] FIG. 1 is a schematic illustration of a prior art implementation of a video traffic external optimization platform (EOP) with an EOP proxy server; [0031] FIG. 2 is a schematic illustration of a novel predictive Internet traffic steering system, constructed and operative in accordance with a preferred embodiment of the present invention; [0032] FIG. 3 is a schematic illustration of an exemplary steering gateway for the system of FIG. 2 ; and [0033] FIG. 4 is a block diagram of a process to be performed by the gateway of FIG. 3 . [0034] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. DETAILED DESCRIPTION OF THE INVENTION [0035] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. [0036] The prior art suffers from many drawbacks. Proxy based EOP implementations do not scale very well. In such an implementation each Internet session is necessarily processed and likely to be terminated by the proxy server. For each such session, the proxy server initially opens a second session opposite the EOP, and possibly a third opposite the originally intended addressee if the EOP cannot process the data. Effectively, the number of sessions in the network more than doubles in a given period of time. The additional resources required for handling the increased number of sessions may negate all or most of the benefit from the bandwidth savings realized by the sessions processed by the EOP. The cost of additional required equipment to provide the required scale of operation may be more expensive than just adding bandwidth. Furthermore, there is a critical limit to the number of instantaneous sessions which can be proxied by commercially available EOP machines. [0037] DPI aided traffic steering may have an advantage vis-à-vis proxy based solutions in that they do not entail terminating each session in the network. However, it may be necessary for the DPI to analyze several packets to “classify” the associated traffic, i.e. to establish the nature of a session's data. If so, by the time that the session is steered to the EOP, valuable information regarding the requested service may no longer be available to the EOP. As an EOP and/or the relevant application server typically require the information from the first few packets of a data session to properly set up and execute the requested service, instead of being optimized by the EOP, the service may fail altogether. [0038] Accordingly, in order for a traffic steering DPI based solution to work reliably, the session data must be forwarded starting with the first packet of the session. Applicant has realized that by “decoupling” traffic classification and traffic steering, a background packet inspection process may be used to identify RASs in real time whose data traffic may benefit from EOP based optimization. Accordingly, by accumulating and referencing profiles of historical session data, it may generally be possible to predict whether or not a given data session may be suitable for processing by a given EOP 25 . In such manner, the entire data session, including the first data packet, may be steered towards an EOP 25 for optimization. [0039] Reference is now made to FIG. 2 which illustrates a novel predictive Internet traffic steering system 100 , constructed and operative in accordance with a preferred embodiment of the present invention. As in the prior art, PCs 5 may attempt to connect with RASs 30 via Internet 10 . However, data sessions 108 pass through steering gateway 200 before continuing to RASs 30 . Steering Gateway 200 may comprise traffic steering utility 210 and DPI utility 220 . Traffic steering utility 210 may be any commercially available or proprietary Internet traffic steering utility such as known in the art. [0040] In accordance with a preferred embodiment of the present invention, DPI utility 220 may provide deep packet functionality similar to that disclosed in PCT patent application PCT/IL08/000829, entitled “A DPI MATRIX ALLOCATOR”, filed on Jun. 18, 2008, which is assigned to the common assignees of the present invention, and hereby disclosed in its entirety by reference. It will be appreciated, however, that DPI utility 220 may be provided by any commercially available or proprietary deep packet inspection utility such as known in the art. [0041] DPI utility 220 may inspect the data packets of data sessions 108 as they pass through gateway 200 . Traffic steering utility 210 may rely on input from utility 220 to determine how to steer continuing data sessions 108 ′. If, as may be disclosed hereinbelow, DPI utility 220 may indicate that a given data session 108 may benefit from EOP 25 , utility 210 may steer the associated data session 108 ′ to EOP 25 for processing. If DPI utility 220 may indicate that a data session 108 is not likely to benefit from optimization by EOP 25 , utility 210 may steer continuing data session 108 ′ directly to the originally addressed RAS 30 . [0042] Reference is now made to FIG. 3 which illustrates an exemplary steering gateway 200 , constructed and operative in accordance with a preferred embodiment of the present invention. As in the embodiment of FIG. 2 , steering gateway 200 may comprise traffic steering utility 210 and DPI utility 220 . Steering gateway may also comprise RAS database 230 . As may discussed in detail hereinbelow, RAS database 230 may comprise a list of some or all RASs 30 accessed by users connecting to Internet 10 via steering gateway 200 . Reference is also made to FIG. 4 which illustrates a block diagram of an exemplary predictive steering process 300 to be executed by steering gateway 200 in accordance with a preferred embodiment of the present invention. [0043] DPI utility 220 may inspect (step 310 ) RAS addressing information in the first packet of each new data session passing through steering gateway 200 . Such information may typically be in the form of an IP address and/or URL. Steering gateway 200 may lookup (step 320 ) the indicated RAS 30 in RAS database 230 as per the addressing information. [0044] If both the relevant RAS 30 is found (step 340 ) and the associated profile in database 230 indicates that traffic intended for the RAS is optimizable (step 340 ), steering utility 210 may steer (step 350 ) the data session to an appropriate EOP as per the RAS profile. It will be appreciated that the embodiment of FIG. 2 is exemplary, system 100 may be configured with multiple EOPs 25 associated with a multiplicity of RASs 30 . Accordingly, RAS database 230 may associate one or more EOPs 25 for each RAS 30 associated with optimizable traffic. [0045] If the RAS is not found (step 330 ) and/or if the associated profile in database 230 indicates that traffic intended for the RAS is not optimizable (step 340 ), steering utility 210 may steer (step 335 ) the data session directly to the originally addressed RAS. [0046] It will be appreciated that in such manner an EOP 25 may only handle the specific application related traffic for which it may provide optimization services. As opposed to the prior art where an EOP 25 may be expected to process all of the network's traffic, the present invention substantially reduces the percentage of traffic that is processed by an EOP 25 . For example, in an exemplary network video traffic there may be x data sessions of which one tenth may comprise optimizable video sessions. A prior art EOP proxy server 20 may have to handle x incoming data sessions, initiate an additional x sessions to EOP 25 , and then initiate another 0.9x data sessions with RASs 30 for sessions not handled by EOP 25 . Accordingly, in system 50 proxy server 20 may participate in 2.9x sessions and EOP 25 may participate in x. In contrast, as implemented in system 100 , steering gateway 200 may process only x data sessions and EOP 25 may participate in only 0.1x sessions. [0047] Returning to FIG. 4 , regardless of how the data session may be steered (i.e. whether via step 335 or step 350 ), DPI utility 220 may continue to inspect and analyze (step 360 ) the next several packets of the data session. [0048] Based on the results of step 360 , steering gateway 200 may update (step 370 ) RAS database 230 . For example, if the indicated RAS 30 was not found in the lookup of step 320 , gateway 200 may add a new record in database 230 with an associated profile per the addressing information of RAS 30 . The profile may then be updated as per the results of step 360 . If the analyzed data appears to be optimizable by an EOP 25 , then the record will be updated with at least one relevant EOP 25 . Accordingly, the next time a data session attempts to connect with the indicated RAS, steering gateway 200 may steer the data session to the relevant EOP 25 instead of directly to the RAS. [0049] It will be appreciated that in such manner, database 230 may be populated over time based on the historical results of step 360 . It will further be appreciated that system 100 may therefore begin operation in “learning mode” without an initial list of RAS profiles in database 230 . Steering gateway 200 may simply steer all incoming data sessions to their originally addressed RASs 30 until such time as an incoming RAS 30 may be found in database 230 . However, it will also be appreciated that RAS database 230 may be initialized with a list of known RAS profiles prior to the start of operation. [0050] There may be occasions on which the results of step 370 may not match the associated profile in RAS database 230 . For example, according to the profile, the data associated with the indicated RAS 30 may not be customizable, whereas the results of step 360 may indicate that the data may be customizable. Gateway 200 may be configured to update (step 370 ) RAS database 230 in accordance with the most recent results of step 36 . Alternatively, gateway 200 may be configured wait until the results of step 360 are confirmed one or more additional times before updating database 230 . [0051] It will be appreciated that the present invention may provide benefit even if a particular EOP 25 may not require proxy functionality, i.e. the EOP functionality does not require any session termination or other proxy like functionality. In the absence of the present invention, the EOP may be required to pre-process every session in the network if it may receive a direct feed of Internet traffic with no steering or filtering. Such pre-processing may likely require an EOP to handle traffic volumes much larger than necessary, thus leading scalability issues. [0052] It will also be appreciated that system 100 as illustrated in FIG. 2 may be exemplary. System 100 may not be limited to steering for any particular EOP 25 and/or RAS 30 . Furthermore, unlike the prior art, system 100 may be configured to support a multiplicity of different EOPs 25 processing a multiplicity of different types of data traffic. [0053] It will also be appreciated that steering gateway may comprise an EOP database (not shown) that may store details regarding EOPs 25 recognized by gateway 200 . The EOP database, may, for example, store a usage profile and addressing information for EOPs 25 . Gateway 200 may use the usage profile to identify an appropriate EOP for a customizable data session identified by DPI unit 220 , and steering unit 210 may use the addressing information to steer the data session accordingly. [0054] In accordance with a preferred embodiment of the present invention, steering gateway 200 may also comprise a load balancing unit (not shown) which may enable steering gateway 200 to distribute traffic among EOPs and RASs in a generally even manner. Some EOPs and/or RASs may be comprised of multiple servers operating in tandem. DPI unit 220 may forward information to the load balancing unit regarding ongoing data sessions with the individual servers components of relevant EPOs and RASs. The load balancing unit may use this information to instruct steering unit 210 in a manner such that the loads on the individual servers are generally even. [0055] Unless specifically stated otherwise, as apparent from the preceding discussions, it is appreciated that, throughout the specification, discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining,” or the like, refer to the action and/or processes of a computer, computing system, or similar electronic computing device that manipulates and/or transforms data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices. [0056] Embodiments of the present invention may include apparatus for performing the operations herein. This apparatus may be specially constructed for the desired purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk, including floppy disks, optical disks, magnetic-optical disks, read-only memories (ROMs), compact disc read-only memories (CD-ROMs), random access memories (RAMs), electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, Flash memory, or any other type of media suitable for storing electronic instructions and capable of being coupled to a computer system bus. [0057] The processes and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method. The desired structure for a variety of these systems will appear from the description below. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein. [0058] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

An Internet steering gateway includes a deep packet inspection (DPI) utility for ascertaining an indication of a destination remote application server (RAS) from a first packet of a data session, an RAS database to at least store an optimization profile for each of a multiplicity of the RASs, and a steering utility to steer the data session to one of at least one external optimization platform (EOP) and a RAS as per the optimization profile associated with the indication. A method for optimizing network service delivery, includes inspecting a first packet of a data session with a deep packet inspection (DPI) utility, identifying a destination address for an RAS from the first packet, looking up the RAS in a RAS database as per the destination address; and for a the RAS found in the RAS database, steering the data session in accordance with a profile associated with the RAS.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a division application based on U.S. application Ser. No. 13/241,165 filed on Sep. 22, 2011. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a functional polyurethane prepolymer, a method of preparing polyurethane by using the functional polyurethane prepolymer, and an application method thereof, in particular to a functional polyurethane prepolymer prepared by a non-isocyanate route, a method of preparing polyurethane by a using the functional polyurethane prepolymer, and an application method thereof. [0004] 2. Description of Related Art [0005] Polyurethane (PU) is a common polymer material widely used as a sports cushion material, an elastomer material, an adhesive material, a waterproof material or a coating material. [0006] In a conventional PU preparation process, the PU is synthesized by using isocyanates (such as diisocyanates and polyisocyanates) and polyols (such as diols or polyhydroxy polyols with high functionality) as major raw materials, but the manufacturing process of this sort usually requires phosgene which is a severely toxic pollutant. If the phosgene is leaked accidentally during the manufacturing process, the phosgene will pose an immediate threat to our environment and jeopardize our health such as causing pulmonary edema, and the manufacturing process itself will lead to a certain degree of risk. Therefore, scientists attempt to use non-isocyanates routes (which use absolutely no isocyanates at all) to manufacture polyurethane (PU). [0007] In 1993, Takeshi Endo proposed a PU manufacturing method without using any diisocyanates, wherein five-membered cyclic carbonates (Bis(cyclic carbonate)s) and primary amines are reacted at room temperature to produce a high yield of β-position hydroxyl PU (2-Hydroxyethylurethane), and the reaction is represented by the following chemical equation: [0000] [0008] Typically, the starting material (cyclic carbonate) of hydroxyl PU is prepared by a nucleophilic ring opening reaction of oxirane and carbon dioxide. As indicated in past literatures, cyclic carbonate is mainly prepared by a reaction of oxirane, carbon dioxide, and a catalyst at high pressure, and the common catalysts include amine, phosphine, quaternary ammonium salt, antimony compound, porpyrin and transition metal complex, and the manufacturing conditions and process involve a high level of difficulty. Until recent years, the ring opening reaction of oxirane and carbon dioxide taken place at normal pressure (1 atmosphere) was developed. [0009] Professor Takeshi Endo, et al. further published a preparation of hydroxyl PU by using di-functional amines and di-functional cyclic carbonates, and subsequent research reports related to the ring opening reaction of cyclic carbonates provided the related reaction conditions, and specifically pointed out that the ring opening reaction has a high chemoselectivity, and will not be affected by existing water, alcohols, or esters, so that the cyclic carbonate can be reacted with a compound containing a primary amine under appropriate reaction conditions for a ring-opening polymerization, and the reaction is represented by the following chemical equations: [0000] [0010] However, the aforementioned method is developed for the PU prepolymer with an amino functional group at an end and having a maximum average molecular weight falling within the range from 5000 g/mole to 8000 g/mole. The ring opening reaction process of the aforementioned method requires a time (20 hours or more), and this product cannot be applied for a coating application directly and effectively. SUMMARY OF THE INVENTION [0011] The present invention provides a method of preparing a polyurethane (PU) prepolymer, and the method does not use any conventional isocyanate as a raw material, and the manufacturing process does not require the use of phosgene. Epoxy resin and carbon dioxide are used as major raw materials for the preparation of the macromolecular polyurethane prepolymer. [0012] The preparation method of the present invention comprises the following steps: [0013] (1) Material mixing: An epoxy resin and a catalyst are mixed uniformly until the epoxy resin is dissolved completely to form a mixed raw material; and [0014] (2) Thermal reflux: Carbon dioxide gas is introduced into the mixed raw material, and a thermal reflux is performed at a high temperature for a predetermined time to form a bis-(cyclic carbonate) containing compound (BCC). [0015] The aforementioned reaction is represented by the following chemical equations: [0000] [0000] wherein R is [0000] [0016] (3) Ring-opening polymerization: After a bis-(cyclic carbonate) containing compound (BCC) and a di-amine compound are mixed uniformly, and the ring-opening polymerization is represented by the following chemical equations: [0000] [0017] (4) The amino-terminated PU prepolymer (obtained from the above reaction) is mixed and reacted with a di-acrylate compound (AHM) via a Michael to obtain an UV curable polyurethane, and the Michael addition is represented by the following chemical [0000] [0018] The present invention further provides a method of preparing polyurethane comprising the following steps: (1) Material mixing: An epoxy resin and a first catalyst are mixed uniformly until the epoxy resin is dissolved completely to form a mixed raw material; (2) Thermal reflux: Carbon dioxide gas is introduced into the mixed raw material, and a thermal reflux is performed at a high temperature for a predetermined time to form a bis-cyclic carbonate-containing oligomer; (3) Microwave reaction: The bis-cyclic carbonate-containing oligomer is mixed with a second catalyst uniformly, and then a ring-opening polymerization with one or more di-amine compound is performed to form a PU prepolymer containing an amino group at an end; and (4) Michael reaction: The aforementioned PU prepolymer with mixed with a third catalyst uniformly, and then a compound with an acrylic functional group is added to perform a Michael reaction at a low temperature to form an UV curable polyurethane. [0023] The present invention further provides an application method of polyurethane, wherein the polyurethane is produced by using an epoxy resin, carbon dioxide and a polyamine compound as major raw materials, and the application method comprises the following steps: (1) Dipping: An UV curable PU (UV-PU) material and a photoinitiator are mixed uniformly to form a PU raw material solution, and a fabric is placed into the PU raw material solution for pressure suction. Make sure the fabric absorbs a sufficient amount of the PU raw material. (2) Photoreaction: The treated fabric is placed into a medium pressure mercury lamp UV irradiation is provided for fixing the PU raw material solution onto a surface of the fabric. [0026] The method of the present invention does not require the conventional use of isocyanates and polyols as raw materials for preparing PU, and epoxy resin and carbon dioxide, and then di-amine oligomer are used as starting raw materials and polyamines are added to prepare the PU prepolymer, and the PU prepolymer produced by this method can be further used for synthesizing an UV curable PU (UV-PU) in a simple and convenient manner, and the UV-PU can be further coated onto a fabric surface, and the fabrics with UV-cured PU surface treatment is adopted to form a washing resisting and long-lasting hydrophilic or hydrophobic PU treated fabrics. BRIEF DESCRIPTION OF THE DRAWINGS [0027] The invention, as well as its many advantages, may be further understood by the following detailed description and drawings in which: [0028] FIG. 1A shows a Fourier infrared spectrum of polypropylene glycol diglycidyl ether (PPG-DGE) used in a first preferred embodiment of the present invention; [0029] FIG. 1B shows a Fourier infrared spectrum of PPG-type cyclic carbonates formed in the first preferred embodiment of the present invention; [0030] FIG. 2 shows a Fourier infrared spectrum of polyurethane (PU) formed in the first preferred embodiment of the present invention; [0031] FIG. 3 is a SEM photo of the produced UV curable polyurethane coated onto surfaces of fabric fibers and washed by water for 30 times in accordance with the first preferred embodiment of the present invention; [0032] FIG. 4A shows a Fourier infrared spectrum of bisphenol A epoxy resin used in a second preferred embodiment of the present invention; [0033] FIG. 4B shows a Fourier infrared spectrum of bis(cyclic carbonates) (BCC) formed in the second preferred embodiment of the present invention; [0034] FIG. 5 shows a 1 H NMR spectrum of bisphenol A epoxy resin used in the second preferred embodiment of the present invention; [0035] FIG. 6A shows a 1 H NMR spectrum of bis(cyclic carbonates) (BCC) formed in the second preferred embodiment of the present invention; [0036] FIG. 6B shows a 13 C NMR spectrum of bis(cyclic carbonates) (BCC) formed in the second preferred embodiment of the present invention; spectrum; [0037] FIG. 7 is a Fourier infrared spectrum of polyurethane (PU) formed in the second preferred embodiment of the present invention; and [0038] FIG. 8 shows a SEM photo of the produced UV cross-linking polyurethane coated onto surfaces of fabric fibers, processed by a UV light bridge, and washed by water for 30 times in accordance with the second preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0039] In the first preferred embodiment, the polyurethane (PU) prepolymer is prepared by an epoxy resin which is polypropylene glycol diglycidyl ether (PPG-DGE), and the aforementioned polyurethane prepolymer is used for manufacturing polyurethane (PU) and UV curable polyurethane (UV-PU), and the UV curable polyurethane (UV-PU) is further applied as a water-resisting material. [0040] (1) Method of Preparing Polyurethane Prepolymer: [0041] In this preferred embodiment, the polyurethane prepolymer is bis(cyclic carbonate) which is a PPG-type cyclic carbonate, the epoxy resin is polypropylene glycol diglycidyl ether (PPG-DGE), and the catalyst is lithium bromide (LiBr), and the method of preparing a PU prepolymer comprises the following steps: [0042] (S11) Material mixing: PPG-DGE (5 moles) and lithium bromide (5 mole percents) are mixed uniformly until the PPG-DGE is dissolved completely to form a mixed raw material; and [0043] (S12) Thermal reflux: Carbon dioxide gas is introduced into the mixed raw material, and a thermal reflux is performed at the pressure of one atmosphere and a temperature of 100° C. for 24 hours to form a bis(cyclic carbonate) product. [0044] In this preferred embodiment, a large quantity of deionized water and ethyl acetate are used for rinsing the bis(cyclic carbonates) product to remove remained catalysts and achieve the purification effect, so as to obtain a highly pure transparent colorless bis(cyclic carbonate) liquid. [0045] With reference to FIGS. 1A and 1B , a Fourier-transformed infrared spectroscopy is used for detecting and tracing the elimination state of the epoxy functional group (910 cm −1 ) and the formation state of the cyclic carbonate functional group (1800 cm −1 ). The Fourier infrared spectra show that the epoxy functional group is fully converted into the cyclic carbonate functional group. [0046] (2) Method of Preparing PU Prepolymer Containing an Amino Group at an End: [0047] The bis(cyclic carbonates) product produced by the aforementioned method can be used for manufacturing a PU prepolymer containing an amino group at an end, and the method comprises the following steps: [0048] (S21) Microwave treatment: The aforementioned bis(cyclic carbonate) product (0.1 mole), lithium bromide (5 mole percents) and Jeffamine compound (a di-amine D-2000, 0.15 mole) are mixed uniformly, and then a microwave reactor with the power of 100 W is provided for performing a ring-opening polymerization for half an hour to form a PU prepolymer containing an amino group at an end. [0049] With reference to FIG. 2 for a Fourier-transformed infrared spectrum of PU obtained in accordance with the preparation method of the present invention, a formation of an amino ester functional group is observed at the wavelength of 1720 cm −1 , indicating that the cyclic carbonate functional group (1800 cm −1 ) of the cyclic carbonate functional group in this step will disappear with the reaction time, and will be converted into an amino ester functional group (1720 cm −1 ). [0050] In the microwave treatment step (S21), the Jeffamine compound is a polyamine compound well known to those ordinarily skilled in the art, and the compound used in this preferred embodiment is one selected from the group of hydrophilic aliphatic diamines (such as 1,4-butanediol bis-3-aminopropyl ether), ethylene diamines, aliphatic diamines (such as 1,12-diaminododecane), aromatic diamines (such as m-xylyene diamine) or a hydrophobic diamine compounds, such as polydimethylsiloxane (PDMS) diamine. [0051] In addition, the microwave treatment step (S21) further selectively adds a solvent for a dilution to reduce the viscosity of the reactants, wherein the solvent can be ethyl lactate (EL), and the quantity of EL in this preferred embodiment is equal to 10 mL, and the Fourier infrared spectrum of the PU containing an amino group at an end after the reaction takes place is the same as that of the one added with a catalyst. [0052] Further, microwave intensity used in the microwave treatment step (S21) can be adjusted to a range from 15 W to 150 W, and the microwave treatment time can be adjusted to a range from 0.5 hour to 2 hours. [0053] (3) UV Curable Polyurethane (UV-PU): [0054] The PU prepolymer formed in accordance with the aforementioned method can be further used for manufacturing an UV-PU, and the method comprises the following steps: [0055] (S31) Michael reaction: The aforementioned PU prepolymer and a catalyst (triethyl amine, TEA) (5 mole percents) are mixed uniformly, and then 20 mL of ethyl acetate is added, and the mixed materials are dropped slowly into 0.2 mole of a compound containing diacrylate at 0° C. (or in an ice bath), and the Michael reaction is performed in the ice both for 24 hours to remove the catalyst TEA and ethyl acetate to produce an UV-PU material. [0056] In the Michael reaction step (S31), the ethyl acetate solvent may not be added for the reaction. [0057] (4) Application of UV-PU: [0058] The UV-PU material obtained in accordance with the method of the present invention can be used for forming a mesh bonding on a fabric surface and can be embedded into the surface of fiber bundles easily, so that the hydrophilic polymer in the fabric will not be changed or lost easily by rinsing, and the original hydrophilic property of the hydrophilic resin can be maintained, so as to obtain the long-lasting rinsing-resisting super-absorbent fabric, and the application method comprises the following steps: [0059] Dipping: The aforementioned UV-PU material is diluted by ethyl acetate (EA) to the concentration of 1˜10 wt %, and 5 phr of photoinitiator benzoin alkyl ether (1173) is added to form a UV-PU solution, and different fabrics (PET) are placed into the aforementioned UV-PU solution for pressure suction. After the fabric sufficiently absorbs the solution, and a fabric is placed into the PU raw material solution for pressure suction and make sure that the fabric absorbs a sufficient amount of PU raw material. [0060] Photoreaction: The aforementioned fabric is placed into a medium pressure mercury lamp UV irradiation for fixing the PU raw material solution onto the treated fabric to form a double-bond methyl acrylic functional group in of the UV-PU material, and a radical cross-linking reaction is performed to produce a mesh bonding, and the UV-PU material can be embedded into a surface of the fiber bundles easily, so that the hydrophilic polymer in the fabric will not be damaged or lost easily by rinsing, and the original hydrophilic property of the hydrophilic resin can be maintained, so as to obtain the long-lasting washing-resisting super-absorbent fabric. [0061] With reference to FIG. 3 for a SEM photo of the produced UV-PU solution coated onto surfaces of fabric fibers and washed by water for 30 times in accordance with the first preferred embodiment of the present invention, the photo shows that the high-density mesh bonding formed by the UV-PU material on the fabric surface is not damaged or lost by rinsing, and the original hydrophilic property of the hydrophilic resin is maintained. [0062] In this preferred embodiment, the photoinitiator is a photosensitizing agent such as benzophenone (BP) or a reactive diluent with acrylic double bonds is added into the UV-PU solution to increase the concentration of the acrylic double bonds, so as to enhance the crosslink density of the UV-PU material. [0063] In the second preferred embodiment, bisphenol A epoxy resin such as diglycidyl ether bisphenol A (DGEBA) is used as the epoxy resin for preparing the polyurethane prepolymer, and the aforementioned polyurethane prepolymer is used for manufacturing polyurethane (PU) and UV cross-linking polyurethane (UV-PU), and the UV cross-linking polyurethane (UV-PU) is further applied as a water-resisting coating material. [0064] (1) Method of Preparing Polyurethane Prepolymer: [0065] In this preferred embodiment, the bis(cyclic carbonates) (BCC) so formed is a polyurethane prepolymer, the epoxy resin is di-glycidyl ether of bisphenol A (DGEBA), and the catalyst is lithium bromide (LiBr). The method of preparing a polyurethane prepolymer comprises the following steps: [0066] (S11) Material mixing: DGEBA (5 moles) and lithium bromide (5 mole percents) are mixed uniformly until the DGEBA is dissolved completely to form a mixed raw material; and [0067] (S12) Thermal reflux: Carbon dioxide gas is introduced into the mixed raw material, and a thermal reflux is performed at a pressure of one atmosphere and a temperature of 100° C. for 24 hours to form a BCC product (or oligomer). [0068] The BCC product obtained in accordance with this preferred embodiment can be rinsed by a large quantity of deionized water to remove remained catalyst and solvent to achieve the purification effect, and then baked and dried to a fine pure white BCC powder. [0069] With reference to FIGS. 4A , 4 B, 5 , 6 A and 6 B for Fourier infrared spectra that detect the elimination state of the epoxy functional group (910 cm −1 ) and the formation state of the cyclic carbonate functional group (1800 cm −1 ), the Fourier infrared spectra show that the epoxy functional group is sufficiently converted into the cyclic carbonate functional group. In addition, a nuclear magnetic resonance (NMR) is used for performing a structure analysis to confirm the molecular structure of the BCC product produced in according to the procedure of this preferred embodiment. [0070] (2) Method of Preparing a PU Prepolymer Containing an Amino Group at an End: [0071] The BBC product produced in accordance with the aforementioned method can be used for preparing a PU prepolymer, and the preparation method comprises the following steps: [0072] (S21) Microwave treatment: The aforementioned BBC product (0.1 mole), lithium bromide (5 mole percents) and aliphatic amine which is Jeffamine D-2000 (0.15 mole) are mixed uniformly, and a microwave reactor with the power of 100 W is provided for performing a ring-opening polymerization for half an hour to form a PU prepolymer containing an amino group at an end. [0073] With reference to FIG. 7 for a Fourier-transformed infrared spectrum of PU obtained by this method, a formation of an amino ester functional group is observed at the wavelength of 1720 cm −1 . In this step, the cyclic carbonate functional group (1800 cm −1 ) in the cyclic carbonate functional group disappears with the reaction time and is converted into an amino ester functional group (1720 cm −1 ). The PU prepolymer formed by this method has a molecular weight of 20000 g/mole or above, which can be used more easily in the following applications. [0074] In the microwave treatment step (S21), a solvent can be added to dilute the solution and reduce the viscosity of the reactants, wherein the solvent is ethyl lactate (EL) or ethyl acetate (EA), and the quantity of the solvent used in this preferred embodiment is equal to 10 mL, and the Fourier infrared spectrum of the produced PU prepolymer containing an amino group at an end shows the same result with the one added with a catalyst. [0075] (3) Method of Preparing UV Curable Polyurethane (UV-PU): [0076] The PU prepolymer produced according to the aforementioned method can be used for preparing the UV-PU, and the preparation method comprises the following steps: [0077] (S31) Michael reaction: The aforementioned PU prepolymer and a catalyst (triethyl amine, TEA) (5 mole percents) are mixed uniformly, and then 20 mL of ethyl acetate is added, and 0.2 mole of a compound containing diacrylate is dropped into the solution slowly at 0° C. (or in an ice bath), and then the Michael reaction is performed in the ice bath for 24 hours to remove the catalyst TEA and ethyl acetate to produce an UV-PU material. [0078] In the Michael reaction step (S31), the solvent ethyl acetate solvent may not be used in the reaction. [0079] In this preferred embodiment, the compound containing diacrylate is 3-Acryloyloxy-2-hydroxypropyl methacrylate. [0080] (4) Application of UV-PU: [0081] The UV-PU material obtained according to the method of the present invention method can be used to form a mesh bonding on a fabric surface and can be embedded into a surface of fiber bundles successfully, so that the hydrophilic polymer in the fabric will not be changed or lost easily by rinsing, and the original hydrophilic property of the hydrophilic resin can be maintained, the long-lasting washing-resisting super-absorbent fabric. The application method comprises the following steps: [0082] Dipping: The aforementioned UV-PU material is diluted by ethyl acetate (EA) to a concentration of 1˜10 wt %, and then 5 phr of photoinitiator such as benzoin alkyl ether, (1173) is asked to form a UV-PU solution, and various different fabrics (PET, cotton) are placed into the UV-PU solution for pressure suction and make sure that the fabric absorbs a sufficient amount of PU raw material. [0083] Photoreaction: The aforementioned fabric is placed into a medium pressure mercury lamp UV irradiation for fixing the PU raw material solution onto the treated fabric to form a double-bond methyl acrylic functional group in of the UV-PU material, is used for performing a radical cross-linking reaction of the double-bond methyl acrylic functional group in the UV-PU material to produce a mesh bonding, and the UV-PU material can be embedded into the surface of fiber bundles successfully, so that the hydrophilic polymer in the fabric will not be damaged or lost easily by rinsing, and the original hydrophilic property of the hydrophilic resin can be maintained, so as to obtain the long-acting washing-resisting super-absorbent fabric. [0084] With reference to FIG. 8 for a SEM photo of the produced UV cross-linking polyurethane coated onto surfaces of fabric fibers and washed by water for 30 times in accordance with the second preferred embodiment of the present invention, the SEM photo shows that the high-density mesh bonding of the UV-PU material formed on the fabric surface is not damaged or lost by rinsing, and the original hydrophilic property of the hydrophilic resin is maintained. [0085] In this preferred embodiment, the photoinitiator is a photosensitizing agent such as benzophenone (BP) or a reactive diluent with acrylic double bonds is added into the UV-PU solution to improve the crosslink density of the UV-PU material. [0086] In this preferred embodiment, the epoxy resin is bisphenol A epoxy resin or di-glycidyl ether of bisphenol A (DGEBA). However, the invention is not limited to these substances only, but any equivalent epoxy resin such as Epoxy-128, Epoxy-506, Epoxy-904, aliphatic epoxy resin, PPG-DGE, PEG-DGE and any combination of the above can be used in the present invention as well. [0087] In summation of the description above, the present invention provides a novel process for manufacturing the polyurethane prepolymer and the UV curable polyurethane without using isocyanates and polyols as raw materials, so as to avoid the use of harmful substance such as phosgene and reduce the risk of harming our environment. In addition, the method of the present invention is simple and convenient and requires no specific ambient conditions. Compared with the conventional preparation methods, the present invention has the advantages of protecting the environmental and achieving the energy-saving and carbon reduction effects. [0088] Many changes and modifications in the above described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.

A method of preparing polyurethane prepolymer does not require using a toxic isocyanate monomer (manufactured by harmful phosgene) as a raw material. Epoxy resin and carbon dioxide are used as major raw materials to form cyclic carbonates to be reacted with a functional group oligomer, and then amino groups in a hydrophilic (ether group) or hydrophobic (siloxane group) diamine polymer are used for performing a ring-opening polymerization, and the microwave irradiation is used in the ring-opening polymerization to efficiently synthesize the amino-terminated PU prepolymer, and then an acrylic group at an end is added to manufacture an UV cross-linking PU (UV-PU) oligomer which can be coated onto a fabric surface, and the fabric is dried by UV radiation for a surface treatment to form a washing-resisted long lasting hydrophilic or hydrophobic PU fabric.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 08/899,012, filed Jul. 23, 1997 now U.S. Pat. No. 6,455,511, which is a continuation of U.S. patent application Ser. No. 08/310,681 filed Sep. 22, 1994 now abandoned, the disclosures of each of which are incorporated herein by reference in their entirety. FIELD OF THE INVENTION The invention relates to compositions for sports beverages containing an amount of trehalose (α,D-glucopyranosyl α,D-glucopyranoside) sufficient to produce an isotonic or hypotonic solution. Suitable salts, amino acids, flavorings, colorings etc. may also be added as may a variety of additional carbohydrates. BACKGROUND OF THE INVENTION A wide variety of sports beverages are available for replenishing fluids, nutrients and salts during exercise. Carbohydrates not only replace energy sources but also facilitate transport of salts through the wall of the intestinal tract and enhance the concomitant passage of water. A wide variety of carbohydrates are also used to sweeten, adjust osmolarity and provide a timed release form of glucose. Glucose is often the carbohydrate of choice as it is the principal form of sugar in blood. The nutrients are usually in the form of amino acid residues to prevent breakdown of muscle tissues during extreme exercise. Fats, peptides and proteins are difficult to digest and therefore not generally useful in such beverages. A wide variety of salts and minerals are generally added to sports beverages to enhance fluid uptake and to replace the electrolyte balance disrupted by loss of fluids by perspiration during exercise. The actual ability of salts to maintain electrolyte balance has been disputed and some sports beverages do not contain them. For a review of the importance of hydration during exercise, see Noakes, “Fluid Replacement During Exercise” in Exercise and Sport Science Reviews, Vol. 21, Holloszy ed. (1993) pp. 297-330. Original sports beverages were hypertonic (>300 mOsm) in order to deliver the greatest concentration of carbohydrates to athletes. It was found that hypertonic beverages, however, caused fluid to flow into the intestines, causing pressure, pain and increased peristalsis which results in diarrhea and increased dehydration. Most sports beverages are now isotonic or slightly hypotonic. Osmolarity is maintained by adjusting the amount of monosaccharides and, in some cases higher glucose polymers. Canadian Patent Application No. 2,013,820 describes sports beverages containing ten percent by weight of carbohydrates which are a mixture of mono-, di- and polysaccharides which are derived from desalinated and hydrolyzed whey concentrate. European Patent Application Publication No. 587,972 describes a sports beverage without added sugar or artificial sweetener which derives its carbohydrates from fruit juice. European Patent Specification Publication No. 223,540 describes a high energy hypotonic sports beverage containing free glucose and/or sucrose and glucose polymers. The preferred glucose polymers have a degree of polymerization between 4 and 15 and provide a timed release source of glucose. Such polymers of glucose may increase the number of glucose molecules which can be placed in an isotonic solution but do not provide an immediate source of energy as they must be processed over time to individual glucose molecules which are then absorbed through the intestinal tract. Sports beverages are provided in liquid formulations for immediate ingestion and in dry or concentrated formulations which must be mixed with water prior to ingestion. Commonly, the dry components are simply mixed together for subsequent-rehydration. U.S. Pat. No. 4,871,550 provides a method of producing a dry formulation comprising dry blending in separate batches the various factors and then blending the separate batches together to produce a powder which is more easily dissolved in water. It would be useful to provide higher concentrations of a readily assimilable form of glucose in a sports beverage without producing a hypertonic sports beverage. All references cited herein are hereby incorporated by reference. SUMMARY OF THE INVENTION The present invention provides sports beverage formulations containing trehalose as the major carbohydrate source and various salts, nutritional components and other additives. The sports beverages are provided in various forms including powders; liquids, both full strength and concentrated, as well as carbonated and non-carbonated; and tablets. Methods of making the formulations include various forms of preparing powders from an aqueous solution of trehalose and any additional components. DETAILED DESCRIPTION OF THE INVENTION Trehalose, α-D-glucopyranosyl-α-D-glucopyranoside, is a naturally occurring, non-reducing disaccharide initially found associated with the prevention of desiccation damage in certain plants and animals which dry out without damage and revive when rehydrated. Trehalose has been shown to be useful in preventing denaturation of proteins, viruses and foodstuffs during desiccation. See U.S. Pat. Nos. 4,891,319; 5,149,653; 5,026,566; Blakeley et al. (1990) Lancet 336:854-855; Roser (July 1991) Trends in Food Sci. and Tech. 166-169; Colaco et al. (1992) Biotechnol. Internat., 345-350; Roser (1991) BioPharm. 4:47-53; Colaco et al. (1992) Bio/Tech. 10:1007-1011; and Roser et al. (May 1993) New Scientist, pp. 25-28. Trehalose is found extensively in such diverse animal and plant species as bacteria, yeasts, fungi, insects and invertebrates. In insects, it is the major blood sugar. On a routine basis, it is not found in humans, as the only major regular dietary source for man is in certain strains of edible mushrooms. Madzarovova-Nohejlova (1973) Gastroenterology 65:130-133. Trehalose is described for use in a peritoneal dialysis system in U.S. Pat. No. 4,879,280 where it is mentioned as one of several disaccharides as a replacement for the prior art system which utilized glucose. Trehalose is mentioned for use in the dialysis system as a disaccharide that will not be readily cleaved to glucose and thus avoid raising the blood glucose level. Trehalose has also been described as suitable for use in parenteral formulations primarily because it can be sterilized by autoclaving without the browning associated with conventional parenteral formulations. Japanese Patent No. 6-70718. Neotrehalose (O-α-D-glucopyranosyl β-D-glucopyranoside or O-β-D-glucopyranosyl α-D-glucopyranoside) has been described for use in foods and beverages because of its sweetness and rapid absorption by the intestines. Canadian Patent Application No. 2,089,241 and U.S. Pat. No. 5,218,096. Trehalose is described as being unsuitable for such use on the grounds that trehalose is not readily hydrolyzed by enzymes such as amylases, not readily metabolized and absorbed by the human body and “does not release energy in a living body.” Trehalose is not a major component of the human diet, and therefore little in the way of specific information is available on the effects of ingested trehalose. However, information is available on its metabolism. Following oral ingestion, trehalose is not absorbed, as only monosaccharides can pass the intestinal epithelium. Ravich and Bayless (1983) Clin. Gast. 12:335-356. Trehalose is metabolized by the enzyme trehalase into two molecules of glucose. Sacktor (1968) Biochem. 60:1007-1012. Trehalase is a normal constituent of most mammalian bodies, including humans, and has been identified in human serum, lymphocytes and the liver, but is principally located in the brush border of both the intestinal tract and the renal proximal tubules. Belfiore et al. (1973) Clin. Chem. 19:447-452; Eze (1989) Biochem. Genet. 27:487-495; Yoshida et al. (1993) Clin. Chim. Acta 215:123-124; and Kramers and Catovsky (1978) Brit. J. Haematol. 38:453-461. Trehalase is a membrane-bound protein found in the human and animal intestinal tract. Bergoz et al. (1981) Digestion 22:108-112; Riby and Garland (1985) Comp. Biochem. Physiol. 82B:821-827; and Chen et al. (1987) Biochem. J. 247:715-723. The process by which intestinal trehalase metabolizes exogenous trehalose has been described. Intestinal hydrolases, such as trehalase, are surface components attached to the external side of the luminal membrane microvilli, and may be anchored to the membrane by phosphatidylinositol. Maestracci (1976) Biochim. et Biophys. Acta 433:469-481; and Galand (1989) Comp. Biochem Physiol. 94B:1-11. Trehalose is hydrolyzed on the brush border surface of the enterocyte, where the two subsequent glucose molecules are released in close proximity to the membrane. Ravich and Bayless (1983). There, glucose molecules are absorbed by an active rather than a passive transport system. This physiological function was originally described in conjunction with others sugars as “membrane contact digestion.” Thus, the disaccharide trehalose cannot be absorbed across the luminal membrane and likely explains why it has not been identified in human plasma. It has now been found that, in spite of the inability of trehalose to be absorbed across the intestine and its breakdown to glucose by trehalase in the intestine, it is suitable for use in sports beverages where it is preferred that isotonicity or hypotonicity of the beverage be maintained within the intestine. Thus the active transport of the glucose molecules produced by trehalase allows trehalose to be metabolized to glucose prior to absorption, and then normal physiological pathways metabolize the glucose. Without the active transport of glucose produced on the breakdown of trehalose, the intestinal concentration of glucose would increase resulting in an increase of osmolarity and subsequent discomfort. The use of trehalose as the primary carbohydrate source in sports beverages does not increase the osmolarity of the intestinal contents upon breakdown by trehalase, provides blood glucose levels two-fold over that of glucose alone and does not cause the delay in increasing blood glucose levels as when glucose polymers or other, non-glucose, carbohydrates are used. Trehalose also provides the advantage that it has a pleasant flavor which is not excessively sweet, does not produce an unpleasant mouthfeel upon ingestion and encourages greater fluid intake. Unlike synthetic sugars such as neotrehalose, trehalose is made by a wide variety of organisms and has been found to be well tolerated by humans. Trehalose is also rapidly and completely dissolved in water and thus provides an exceptionally clear sports beverage. Many commercially available sports beverages are cloudy or contain particulate matter; the use of trehalose avoids these drawbacks. The use of trehalose also allows the beverage to be carbonated. Other advantages of the use of trehalose will be discussed herein. In one embodiment, the present invention encompasses ready-to-drink sports beverages in aqueous solution. The sports beverages contain as their primary source of carbohydrate trehalose. Preferably, the concentration of trehalose and any other carbohydrates is sufficient to obtain an isotonic or slightly hypotonic solution, although hypertonic or slightly hypertonic formulations may be provided. Preferably, trehalose and other solutes are present in an amount sufficient to provide an isotonic or slightly hypotonic solution. If trehalose is the sole solute, the concentration required to obtain an isotonic solution is 300 mM. A 1 molar solution of trehalose results in a solution with an osmolarity of 1665 mOsm. 11.34 g of trehalose dihydrate dissolved in distilled deionized water to a final volume of 100 mL results in an isotonic solution with an osmolarity of 300 mOsm. Preferably the concentration of trehalose is 150 mM to 400 mM. More preferably the concentration is 250 mM. The beverage should be 300 mOsm or less; thus, if the concentration of trehalose is insufficient to attain 30 mOsm, additional carbohydrates or salts may be added to increase the osmolarity. Trehalose is available in food grade from a variety of sources, these include, but are not limited to, yeast. Other suitable carbohydrates include mono-, di- and polysaccharides. Suitable monosaccharides include, but are not limited to, fructose, mannose, glucose and galactose. Suitable disaccharides include, but are not limited to, sucrose, maltose and lactose. Suitable polysaccharides include, but are not limited to, maltodextrins and those described in European Patent Specification Publication No. 223,540. Suitable salts include, but are not limited to, sodium, potassium, magnesium and calcium. European Patent Application Publication No. 587,972 provides an extensive discussion of such salts and suitable concentrations thereof. Suitable sources of the salts include, but are not limited to, sodium chloride, potassium phosphate, potassium citrate, magnesium succinate and calcium pantothenate. Salts are optional, and, as discussed above, are primarily beneficial in increasing fluid intake by the intestinal tract. Thus, the amount of salts added is preferably suitable to affect an increase in fluid intake without resulting in an unpalatable drink. In addition to carbohydrates and salts, the sports beverage may also contain various other nutrients. These include, but are not limited to, vitamins, minerals, amino acids, peptides and proteins. Suitable vitamins include, but are not limited to, vitamin C, the B vitamins, pantothenic acid, thiamin, niacin, niacinamide, riboflavin, iron and biotin. Minerals include, but are not limited to, chromium, magnesium and zinc. Preferably, amino acids are included rather than peptides and proteins which require digestion prior to absorption. Suitable amino acids include, but are not limited to, the twenty amino acids utilized by humans. U.S. Pat. No. 4,871,550 discusses preferred amino acids. The effective amounts of the various nutrients are known in the art and are not described in detail herein. Other ingredients including, but not limited to, coloring, flavor, artificial sweeteners and preservatives may also be added. Suitable amounts and types of all ingredients described herein are known in the art and are not described in detail herein. It is within the skill of one in the art to prepare a beverage formulation having suitable concentrations of all the components. The sports beverage is available in several compositions. In one embodiment, the composition is a ready-to-drink aqueous solution that can be packaged in single serving or larger containers. The components are mixed together in sterile, filtered, or carbonated water and packaged for sale. In another embodiment, the components are mixed in an aqueous solution in a concentrated form. An aliquot of the concentrated solution is then mixed with a premeasured amount of water to prepare the beverage. In another embodiment, the composition is a dry powder form in which the dried components are mixed together and milled or mixed in aqueous solution and dried by one of the methods described below. An aliquot of the dried components is mixed with a premeasured amount of water to prepare the beverage. The dry powder may be loose or fashioned into tablets which can be easily added to a premeasured amount of water to prepare the beverage. The invention also encompasses methods of making the sports beverages. The use of trehalose allows heating of the components in solution to a high temperature, at least briefly, without losing activity of other nutrients, without aggregation of other nutrients and without the browning found with many carbohydrates. Thus, the liquid formulations, both ready-to-use and concentrated, can be sterilized by heat treatment to inhibit contamination and increase shelf-life. Products made with trehalose and sterilized have an almost indefinite shelf-life while most available sports beverages have a shelf-life of only a few months or less due to contamination and/or aggregation of the components. Previously, dried powders of sports beverages were merely mixed together in their dry form and milled to achieve a homogeneous powder. The milling has also been performed in separate steps for enhancing the solubility of the final composition. U.S. Pat. No. 4,871,550. The use of trehalose allows the components to be mixed in solution, heated to form a uniform dispersion and dried. The heating may also be used to form a sterile solution. Drying may be by any suitable method, including, but not limited to, spray drying, freeze drying, fluidized-bed drying and critical fluid extraction. One approach is to spray dry using precision nozzles to produce extremely uniform droplets in a drying chamber. Suitable machines include, but are not limited to, Buchi and Lab-plant spray driers used according to the manufacturers' instructions. Aliquots of the dried formulations are mixed with a premeasured amount of water to obtain the desired concentration of solutes. The use of trehalose provides powder which disperses almost immediately and completely in water. Many commercially available powders are hygroscopic and do not mix rapidly or completely with water. The use of trehalose thus avoids long mixing times and the waste common to prior art mixtures. Due to the increased solubility of trehalose formulations, the dried formulations can also be pressed into tablet form. The tablet form avoids the necessity of measuring loose powder and allows the rapid preparation of the sports beverages. For instance, an athlete can carry the tablets during sporting events and add them to water provided during the event. This is particularly helpful during endurance events such as marathons and triathlons where water may be provided but food or other nutrition is not. The following examples are meant to illustrate but not limit the invention. EXAMPLES Example 1 5.0 to 11.34 g of trehalose dihydrate is dry blended at an rpm greater than 18,000 until the consistency of is a uniform powder. Thereafter, the trehalose dihydrate is dissolved in distilled deionized water to a final volume of 100 mL and an osmolarity of 300 mOsm or less. For 11.34 g of trehalose the measured value was 287 mOsm. Measurement of the osmolarity of the final mixture is made on a Roebling Micro-Osmometer. Example 2 5.0 to 11.34 g of trehalose dihydrate is again dry blended at an rpm greater than 18,000 until the consistency is a uniform powder. Between 100 and 500% of the recommended daily allowance of vitamins and minerals is added to the trehalose powder, and the mixture is dry blended again until the milling action reduces the particle size to less than 50 μm. Thereafter, the mixture is dissolved to a final volume of 100 mL. Measurement of the osmolarity of the final mixture is made on a Roebling Micro-Osmometer. Example 3 5.0 to 11.34 g of trehalose dihydrate is again dry blended at an rpm greater than 18,000 until the consistency is a uniform powder. Between 100 and 500% of the recommended daily allowance of vitamins and minerals is added to the trehalose powder. An effective amount of sodium chloride and potassium phosphate are added in order to increase the fluid uptake by the intestinal tract. The mixture is dry blended again until the milling action reduces the particle size to less than 50 μm. Thereafter, the mixture is dissolved to a final volume of 100 mL. Measurement of the osmolarity of the final mixture is made on a Roebling Micro-Osmometer. Example 4 5.0 to 11.34 g of trehalose dihydrate is again dry blended at an rpm greater than 18,000 until the consistency is a uniform powder. Between 100 and 500% of the recommended daily allowance of vitamins and minerals is added to the trehalose powder. An effective amount of sodium chloride and potassium phosphate are added in order to increase the fluid uptake by the intestinal tract. The mixture is dry blended again until the milling action reduces the particle size to less than 50 μm. Thereafter, the mixture is dissolved to a final volume of 100 mL. An amount of color additives effective to improve the visual appeal of the final product is added. Flavor additives are also added in an amount necessary to provide a palatable taste. Measurement of the osmolarity of the final mixture is made on a Roebling Micro-Osmometer. Example 5 The solutions prepared by the examples 1 through 4, may then be carbonated using conventional techniques known in the art. Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be apparent to those skilled in the art that certain changes and modifications may be practiced. Therefore, the description and examples should not be construed as limiting the scope of the inventions, which is delineated by the appended claims.

The invention provides sports beverages which supply a readily metabolizable, natural carbohydrate, trehalose. The use of trehalose provides twice the concentration of glucose molecules for immediate energy compared to monosaccharide solutions of the same osmolarity.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 60/180,557 filed Feb. 4, 2000. BACKGROUND OF THE INVENTION [0002] A. Field of the Invention [0003] The invention relates generally to surgical microscopes, and more particularly to an improved configurations for linking a microscope body to an external power supply, control device, and light source. [0004] B. Description of the Prior Art [0005] A “surgical microscope” for the purposes of the invention is understood to be a microscope that is movable with respect to an object and thus possesses a certain flexibility in terms of any connections to external devices. Such microscopes are very often used in surgical operations. Such microscopes are often also used for industrial or commercial applications. [0006] Such microscopes often have an integrated illumination system in which the light source is built into the microscope. Often, however, the light source is remotely located so as to minimize heating, weight, and housing dimensions in the region of the microscope body. With such external accessories, the light is directed through a light guide from the external light source to the microscope body, and through the latter onto the surgical field. [0007] In addition, such microscopes—and video cameras incorporated into them—are often equipped with control elements, for example remotely controllable displacement mechanisms or actuators which comprise on the one hand electrical drive systems but also, on the other hand, sensors or the like whose signals are analyzed in external control systems or circuits. [0008] Such microscopes are often located on the extension arms of stands, while the external devices and control systems are housed in the column region of the stand. [0009] The connection between the external devices and the microscope body or the terminals located thereon is accomplished via flexible lines such as light guides, electrical cables, electronic data lines, etc. As a rule there are numerous such lines, which in many applications are a hindrance. In some cases they interfere with visibility, are heavy, result in jamming and limitations of movement, and moreover look untidy. In addition, they are susceptible to malfunction or can cause failures by being damaged. In the field of surgical microscopy, they result in increased surface areas which thus make the overall structure more susceptible to soiling. [0010] The assignee of the present application has already taken initial steps intended to remedy this unfavorable situation. Assignee's OH stand had provided, between stand arms, a flexible hose through which all the various cables were pulled. This hose was relatively bulky and inflexible, however, and did not make optimum use of space since it had to be made sufficiently large for subsequent installation of an undetermined number of cables, even if not all the cables were pulled through. The dead weight of the hose moreover increased the weight of the stand arms in question. SUMMARY OF THE INVENTION [0011] It is thus the object of the invention to implement the connection between the external devices and the microscope body in as lightweight, easily movable, and retrofittable a fashion as possible, and with as few cables as possible. [0012] The present invention, as broadly defined, achieves this principal object on the basis of a physical size reduction and simultaneous weight reduction. Further improved or developed ways of achieving the object, with greater integration and greater advantages over the existing art, are evident from the various embodiments described herein. [0013] A preferred configuration of a cable according to the present invention, which optionally can also be used independently of the invention, is coaxially multi-layered, one of the layers, but preferably the core of the cable, being configured as a mirror optical system or fiber optical system or as a liquid light guide, while at least two layers are configured as an at least two-pole power cable. Preferably connected to the light-guide portion of such a cable are electro-optical converters for the transfer of control, sensor, and video signals, while the power supply is connected to the power portion. [0014] Further improvements and details of the invention are evident from the drawings, which depict exemplary embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWING [0015] The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the preferred embodiment taken with the accompanying drawing figure, in which: [0016] [0016]FIG. 1 shows a schematic complete surgical microscope according to the present invention, on a stand, with corresponding external devices; [0017] [0017]FIG. 2 shows a detail of a light guide modified in accordance with the invention, having electro-optical data converters and apparatuses for reflecting light in and out; [0018] [0018]FIG. 3 shows another light guide with special armoring; [0019] [0019]FIG. 4 shows a detail of the armoring as shown in FIG. 3; [0020] [0020]FIG. 5 shows a variant of the light guide as shown in FIG. 3; [0021] [0021]FIG. 6 shows a further variant of the light guide as shown in FIG. 3; [0022] [0022]FIG. 7 shows a multi-strand cable as power and data carrier; and [0023] [0023]FIG. 8 shows a two-pole cable that serves as both a power line and a data line. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0024] The figures will be described in overlapping fashion. Identical parts bear identical reference characters; different parts having functions that are identical in principle bear identical reference characters with differing indices. The figures do not limit the invention, but rather are intended as possible exemplary embodiments. [0025] [0025]FIG. 1 shows a schematic configuration with a stand 11 that bears a microscope body 1 and various external devices 12 . These comprise, for example, a computer 13 for control and measurement tasks, a light source 10 for providing light flux that can be used as a power supply 5 and/or directed to microscope body 1 and onto a surgical field. A power connection 4 c in the form of a light guide transmits power in the form of light flux. A control device is connected to remotely controlled drive systems in the microscope, for example via a data connection 7 c integrated, in accordance with the invention, into power connection light guide 4 c . The microscope thus comprises a terminal 3 for power connection 4 c and a terminal 6 for the data connection. [0026] In this example, the data connection is implemented via electro-optical converters 9 a and 9 b that convert electrical signals into optical signals and vice versa. These signals are reflected into and out of light guide 4 c via beam splitters or mirrors 14 a and 14 b , so that by way of these, both the light flux from the light source and the optical signals from converter 9 a are sent to the microscope, and optical signals from converter 9 b are sent in the other direction to computer 13 and to control device 2 . [0027] An extremely wide variety of combinations lies within the context of the invention. For example, the power that is to be transferred can be optical and/or electrical power, while the data can be electrical and/or optical signals. This includes the case in which electrical signals are transferred over the light guide by light modulation. [0028] Some of the possibilities are explained with references to the examples shown in FIGS. 3 through 8: [0029] [0029]FIG. 7 shows a relatively simple configuration which does not provide any integrated light flux transfer, but does provide an electrical power transfer in power wires 4 a of a multi-strand cable 8 a , while data transfer occurs in data lines 7 a of the same cable 8 a. [0030] [0030]FIG. 8 uses only a two-pole power cable 4 b that is of twisted configuration for better shielding effect. By way of this power cable, a high-frequency (relative to the power flow) data transfer is performed simultaneously; for this purpose, corresponding signal couplers 15 a and 15 b are provided, which are connected at the other end to terminal 6 and to computer 13 or control device 2 . [0031] Signal couplers of this kind are optionally also provided in configurations according to FIGS. 3 through 5, if the electrical lines are also intended to be used for data purposes in the case of these configurations. [0032] [0032]FIG. 6 shows a light guide 4 e that has as its core a two-pole electrical cable 4 g. [0033] [0033]FIG. 3 shows another light guide in which a two-pole cable (in this example, a coaxial cable) 4 h is wound as armoring around light guide 4 d . For strengthening purposes, a tubular sheath 16 is also pulled on as an outer layer. [0034] [0034]FIG. 4 shows a detailed depiction of the coaxial cable according to FIG. 3, which of course in addition to power transfer could also be used for data transfer (although with less bandwidth than in the case of light). In this example, what is intended is a data transfer via light guide 4 d. [0035] [0035]FIG. 5 shows a combination of the examples shown in FIG. 3 and in FIG. 6, with a single-pole armoring 4 f 2 that, for example, can also be constituted from a conventional corrugated metal tube, and with a single-pole core 4 f 1 inside light guide 4 e. This configuration also results in a favorable shielding effect due to the coaxial configuration of electrical conductors 4 f 1 and 4 f 2 . Data can thus be transmitted through these easily and without interference, so that data transfer via light guide 4 e can optionally be dispensed with. [0036] The signals mentioned above preferably comprise amplitude-modulated or frequency-modulated current, or light including nonvisible light wavelength regions, for example infrared. [0037] The invention encompasses, on the one hand, corresponding modulation of the electrical or light fluxes that are flowing in the manner of power, and/or the fact that electrical or optical signals are sent, parallel to these flow power fluxes, over the same line in each case. List of Reference Characters:  1 Microscope body  2 Control device  3 Power terminal  4 Power connection  5 Power supply unit  6 Data terminal  7 Data connection  8 Cable  9 Conversion device; electro-optical converter 10 Light source 11 Stand 12 External devices 13 Computer 14 Beam splitter 15 Signal coupler 16 Tubular sheath

The invention concerns a microscope having a power and data transfer system between a microscope body ( 1 ) and an external control device or peripheral device ( 2, 13 ). According to the present invention, the power line ( 4 ) and data line ( 7 ) are laid physically together and are of integrated configuration, thus implementing a lightweight connection comprising few individual cables.

TECHNICAL FIELD [0001] The present invention relates to synchronization between mobile devices and fixed devices, and, more specifically, to systems for resolving conflicts detected during a synchronization session between the mobile device and the fixed device. BACKGROUND OF THE INVENTION [0002] Mobile devices, sometimes referred to as handheld devices, have become quite common today. The users of these mobile devices want to have their mobile device updated with current information quite frequently. The process for updating information involves communicating with a fixed device (i.e., server) and is commonly referred to as a synchronization session. Between synchronization sessions, the mobile device may change information in its mobile store and the fixed device may change information in its server store. If the information that is changed in the mobile store and the server store is associated with the same data object, a conflict is detected during the next synchronization session. In these situations, prior systems that synchronized data objects would provide some type of user interface on the mobile device that would indicate that the conflict existed and that the conflict was with a certain object. In one example, the device user would receive a notification regarding the conflict, when, in fact, the information changed on the object associated with the notification had identical information on both devices (i.e., both devices changed a last name field of a contact object from a maiden name to a married name). In addition to the unhelpful user interface that was provided, prior systems would also keep both versions of the data objects having the conflict on both the mobile device and on the fixed device. As one can imagine, keeping both objects wasted memory on the devices and caused extra work for the user to resolve the otherwise duplicate objects. In addition, sending the other version of the object used bandwidth on the data channel between the devices. Thus, there is a need for an improved method for resolving conflicts detected during a synchronization session that enhances the mobile user's experience. SUMMARY OF THE INVENTION [0003] Briefly described, the present invention provides a method for resolving a conflict detected while synchronizing a first data object in a first store associated with a mobile device and a second data object in a second store associated with a server. In accordance with the present invention, certain conflicts are automatically resolved without requiring user-intervention on the mobile device and without duplicating data objects on either the mobile device or the server. [0004] In general, once a conflict is detected, properties of the first data object are compared with corresponding properties of the second data object. If the corresponding properties that differ are designated as mergeable properties, the corresponding properties are merged. Merging the properties involves sending a preferred state associated with each of the conflicting properties to the mobile device and the server for updating the first data object and second data object, respectively, when an initial state for the properties and the corresponding properties is different than the preferred state. The preferred state is based on a likelihood that vital information would be lost if the preferred state did not replace the initial state of the property or the corresponding property. For example, if a read property for an email object is marked as read on the mobile device and as unread on the server, the preferred state (unread) is sent to the mobile device to update the email object. Thus, a user is insured that if data is lost, the most conservative approach to data loss results, thereby reducing the danger of the data loss. The merging is performed without user-intervention on the mobile device. In addition, the entire first data object or second data object is not sent to the mobile device to achieve the merge, thereby minimizing the data transfer to the mobile device. [0005] In another aspect of the invention, a system for resolving a conflict detected during a synchronization session is provided. The system includes a first device, a second device, and a server. The first device is associated with a first data store that stores several data objects. The second device is associated with a second data store that stores several corresponding data objects. Each data object in the first data stores is associated with one of the corresponding data objects in the second data store. The server is configured to detect a conflict between the data objects and their corresponding data objects by determining whether a property of the data object is different than a corresponding property of the corresponding data object. If the property and the corresponding property are designates as mergeable properties, the server is configured to merge the property of the data object and the corresponding property. The merging is performed without user-intervention on the first device. BRIEF DESCRIPTION OF THE DRAWINGS [0006] [0006]FIG. 1 illustrates an exemplary computing device that may be used in one exemplary embodiment of the present invention; [0007] [0007]FIG. 2 illustrates an exemplary mobile computing device that may be used in one exemplary embodiment of the present invention; [0008] [0008]FIG. 3 is a functional block diagram of one exemplary conflict resolution system as implemented using the computer device shown in FIG. 1 and the mobile computing device shown in FIG. 2; [0009] [0009]FIG. 4 is a graphical representation of one embodiment of the salient portions of a sample data object; [0010] [0010]FIG. 5 is a logical flow diagram generally illustrating an overview of a synchronization process with conflict resolution; [0011] [0011]FIG. 6 is a logical flow diagram illustrating a conflict resolution process suitable for use in FIG. 5; and [0012] [0012]FIG. 7 is a logical flow diagram illustrating a user-selectable conflict process suitable for use in FIG. 6, in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0013] The present invention may be implemented in one or more components operating within a distributed or wireless computing network. Those components may include software programs or applications operating on computing systems of various configurations. Two general types of computing systems are being used to implement the embodiments of the invention described here. Those two general types are illustrated in FIG. 1 and FIG. 2 and described below, followed by a detailed discussion of one illustrative implementation of the invention, illustrated in FIGS. 3 - 7 , based on these two types of computer systems. [0014] Illustrative Operating Environment [0015] With reference to FIG. 1, one exemplary system for implementing the invention includes a computing device, such as computing device 100 . In a very basic configuration, computing device 100 typically includes at least one processing unit 102 and system memory 104 . Depending on the exact configuration and type of computing device, system memory 104 may be volatile (such as RAM), non-volatile (such as ROM, flash memory, etc.) or some combination of the two. System memory 104 typically includes an operating system 105 , one or more program modules 106 , and may include program data 107 . This basic configuration is illustrated in FIG. 1 by those components within dashed line 108 . [0016] Computing device 100 may have additional features or functionality. For example, computing device 100 may also include additional data storage devices (removable and/or non-removable) such as, for example, magnetic disks, optical disks, or tape. Such additional storage is illustrated in FIG. 1 by removable storage 109 and non-removable storage 110 . Computer storage media may include volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. System memory 104 , removable storage 109 and non-removable storage 110 are all examples of computer storage media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by computing device 100 . Any such computer storage media may be part of device 100 . Computing device 100 may also have input device(s) 112 such as keyboard, mouse, pen, voice input device, touch input device, etc. Output device(s) 114 such as a display, speakers, printer, etc. may also be included. These devices are well know in the art and need not be discussed at length here. [0017] Computing device 100 may also contain communication connections 116 that allow the device to communicate with other computing devices 118 , such as over a network. Communications connections 116 is one example of communication media. Communication media may typically be embodied by computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave or other transport mechanism, and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. The term computer readable media as used herein includes both storage media and communication media. [0018] With reference to FIG. 2, one exemplary system for implementing the invention includes a mobile computing device, such as mobile computing device 200 . The mobile computing device 200 has a processor 260 , a memory 262 , a display 228 , and a keypad 232 . The memory 262 generally includes both volatile memory (e.g., RAM) and non-volatile memory (e.g., ROM, Flash Memory, or the like). The mobile computing device 200 includes an operating system 264 , such as the Windows CE operating system from Microsoft Corporation or other operating system, which is resident in the memory 262 and executes on the processor 260 . The keypad 232 may be a push button numeric dialing pad (such as on a typical telephone), a multi-key keyboard (such as a conventional keyboard). The display 228 may be a liquid crystal display, or any other type of display commonly used in mobile computing devices. The display 228 may be touch sensitive, and would then also act as an input device. [0019] One or more application programs 266 are loaded into memory 262 and run on the operating system 264 . Examples of application programs include phone dialer programs, email programs, scheduling programs, PIM (personal information management) programs, word processing programs, spreadsheet programs, Internet browser programs, and so forth. The mobile computing device 200 also includes non-volatile storage 268 within the memory 262 . The non-volatile storage 268 may be used to store persistent information which should not be lost if the mobile computing device 200 is powered down. The applications 266 may use and store information in the storage 268 , such as e-mail or other messages used by an e-mail application, contact information used by a PIM, appointment information used by a scheduling program, documents used by a word processing application, and the like. A synchronization application also resides on the mobile computing device 200 and is programmed to interact with a corresponding synchronization application resident on a host computer to keep the information stored in the storage 268 synchronized with corresponding information stored at the host computer. [0020] The mobile computing device 200 has a power supply 270 , which may be implemented as one or more batteries. The power supply 270 might further include an external power source, such as an AC adapter or a powered docking cradle, that supplements or recharges the batteries. [0021] The mobile computing device 200 is also shown with two types of external notification mechanisms: an LED 240 and an audio interface 274 . These devices may be directly coupled to the power supply 270 so that when activated, they remain on for a duration dictated by the notification mechanism even though the processor 260 and other components might shut down to conserve battery power. The LED 240 may be programmed to remain on indefinitely until the user takes action to indicate the powered-on status of the device. The audio interface 274 is used to provide audible signals to and receive audible signals from the user. For example, the audio interface 274 may be coupled to a speaker for providing audible output and to a microphone for receiving audible input, such as to facilitate a telephone conversation. [0022] The mobile computing device 200 also includes a radio interface layer 272 that performs the function of transmitting and receiving radio frequency communications. The radio interface layer 272 facilitates wireless connectivity between the mobile computing device 200 and the outside world, via a communications carrier or service provider. Transmissions to and from the radio interface layer 272 are conducted under control of the operating system 264 . In other words, communications received by the radio interface layer 272 may be disseminated to application programs 266 via the operating system 264 , and vice versa. [0023] Illustrative Conflict Resolution System [0024] [0024]FIG. 3 is a functional block diagram generally illustrating one embodiment for a synchronization system with conflict resolution 300 that resolves conflicts between data objects detected during a synchronization session between a fixed computing device, such as an information server 310 and a mobile device 320 , in accordance with the present invention. In this implementation, the information server 310 is a computing device such as the one described above in conjunction with FIG. 1, and the mobile device 320 (i.e., client) is a mobile computing device such as the one described above in conjunction with FIG. 2. A synchronization application 342 performs the synchronization process between the information server 310 and the mobile device 320 . The synchronization application 342 includes a conflict manager 380 for detecting and resolving the conflicts during the synchronization sessions. In the embodiment illustrated, the synchronization application 342 resides on a synchronization server 340 , which is a computing device as described above in conjunction with FIG. 1. Alternatively, the synchronization application 342 may reside in any acceptable location, such as directly on the information server 340 or on the mobile device 320 . The synchronization server 340 is shown coupled to the information server 310 over a local or wide area network in the conventional manner. In another embodiment, the synchronization application 342 may reside on information server 310 without departing from the scope of the present invention. [0025] The mobile device 320 maintains mobile data 322 (i.e., a mobile data store) locally in its non-volatile storage 268 (shown in FIG. 2). Information server 310 maintains server data 312 (i.e., a server data store) on its removable storage 109 or non-removable storage 110 (shown in FIG. 1). As mentioned earlier, the mobile data 322 and the server data 312 may include e-mail or other messages used by an e-mail application, contact information used by a PIM, appointment information used by a scheduling program, and the like. Typically, each type of data in the mobile data 322 or server data 312 is referred to as a “collection” (e.g., e-mail and contacts are two separate collections). Each collection includes a plurality of data objects. For example, the server data 312 includes a plurality of server data objects 314 and the mobile data 322 includes a plurality of mobile data objects 324 . A representative illustration of the salient portions of a sample data object is illustrated in FIG. 4 and described below. [0026] The mobile device 320 may change the mobile data 322 on the mobile device 320 at anytime. Once the mobile data 322 is changed, server data 312 accessible by the information server 310 will not have identical information. Similarly, the information server 310 may change the server data 312 , such as through any number of networked personal computers (not shown) connected to the information server 310 . Again, once the server data 312 is changed, the mobile data 322 and server data 312 are no longer identical (i.e., data is not synchronized and the changes on both sides create a conflict). In order for the mobile data 322 and the server data 312 to become identical (i.e., synchronized), typically, the mobile device 320 initiates a synchronization session. During the synchronization session, the synchronization application 342 attempts to update the server data objects 314 and the mobile data objects 324 to have identical information. In other words, after a successfully synchronization session, the server data objects 314 will have a corresponding mobile data object 324 with the same information. [0027] Briefly, during the synchronization session of one embodiment of the present invention, client synchronization data 330 is transmitted between the mobile device 320 and the synchronization application 342 , and server synchronization data 350 is transmitted between the synchronization application 342 and the information server 310 . The client synchronization data 330 specifies changes to the mobile data 322 since the last successful synchronization session and specifies changes to the server data 312 that the mobile device 320 should update on its mobile data 322 . The server synchronization data 350 specifies changes that the information server 310 should make to its server data 312 and specifies changes to the server data 312 that the mobile device 320 should make to its mobile data 322 . The synchronization application 342 saves information regarding the synchronization session in a synchronization state table 344 . [0028] During the synchronization sessions, the conflict manager 380 , briefly described here and illustrated in FIGS. 5 - 7 and described in detail below, determines which of the changes to the mobile data 322 and the server data 312 involve a conflict. After determining there is a conflict, the conflict manager 380 attempts to resolve the conflict without sending a conflict notification 382 to the mobile device 320 . In one embodiment, the client synchronization data 330 includes a parameter 332 , described in more detail with reference to FIGS. 6 and 7, that specifies how automatic conflict resolution should be handled. However, when certain types of conflicts occur, a conflict notification 382 is sent to the mobile device 320 . A sample XML message is shown below that represents a general format for one embodiment of the conflict notification 382 sent to the mobile device 320 . <SYNC> . . . <COLLECTION> <COLLECTIONTYPE>E-MAIL</> <RESPONSES> <RESPONSE> <OBJECT ID>123</> <COMMAND>CHANGE</> <STATUS>READ FLAG MODIFIED</> </> </> . . . </> [0029] As shown, the sample conflict notification includes the object id (shown as “ 123 ”) that has changed and a status (shown as “Read Flag Modified”) describing the type of change that occurred. In general, the conflict notification 382 provides sufficient information to the mobile device 320 such that the mobile device 320 may provide a suitable user interface (not shown) to the user regarding the conflict. The user interface may be implemented in any manner and will depend on how the application 266 (shown in FIG. 2) responsible for displaying the conflict information chooses to relay the conflict information to the user of the mobile device 320 . Because the specific user interface chosen is not pertinent to understand the present invention, the present discussion does not further describe the user interface on the mobile device 320 . The sample conflict notification shown above only includes the property that caused the conflict than the entire object. This embodiment increases the efficiency of the conflict resolution process when using wireless technology because less data is sent. [0030] As will be described in greater detail below, the conflict manager 380 in accordance with the present invention, automatically resolves certain conflicts and provides sufficient conflict notification 382 to the mobile device 320 for a user to select how the conflict should be resolved using the user interface on the mobile device 320 when the conflict can not be automatically resolved. Thus, the present invention provides an efficient method for resolving conflicts in data objects during a synchronization session. [0031] [0031]FIG. 4 is a graphical representation of one embodiment of the salient portions of a sample data object 400 that may be used as a server data object 314 or a mobile data object 324 in conjunction with present invention. The sample data object 400 includes an object id (OID) 402 , a plurality of properties P 1−N , and a change indicator 404 . The object id 402 may be a server ID (SID) if the object ID (OID) is stored on the server 310 or a device ID (DID) if the object ID is stored on the device 320 . As one skilled in the art will appreciate, after synchronization is complete, each SID typically has a corresponding DID on the mobile device to which it is mapped. The properties P 1−N store information associated with the data object based on the type of data object. [0032] A representative data object is illustrated in FIG. 4 and represents an email message object. The illustrative properties for the email message object may include a recipient field P 1 , a sender field P 2 , a read flag field P 3 , a message text field P 4 , a subject field P 5 , a data last read field P 6 , a priority field P 7 , a follow-up flag field P 8 and any other information regarding the email message object. The change indicator 404 indicates when any the properties P 1−N of the data object 400 have changed. For example, if a user reads the email message, property # 4 (read property) is set to indicate read and the change indicator 404 is marked indicating that the data object 400 has changed in some way. When the change indicator 404 is so marked, the data object 400 is sometimes referred to as “dirty”. The data object 400 is considered “dirty” even if the user reads the email message and then sets the email message as unread (the value of property # 4 would, in essence, remain the same). [0033] In accordance with the present invention, certain properties are also designated as syncable properties 406 . Syncable properties 406 are properties within the data object 400 that may be changed. Typically, properties that cannot be changed are not designated as syncable properties (e.g., the recipient field P 1 and the sender field P 2 ). However, these non-changeable properties may be designated as syncable properties without departing from the scope of the present invention. In addition, in accordance with the present invention, some of the designated syncable properties 406 are further designated as mergeable properties 408 (e.g., the read property P 3 ). As will be described in detail below in reference to FIGS. 5 - 7 , the conflict manager uses the change indicator 404 , the syncable properties 406 and the mergeable properties 408 when determining a “true” conflict and resolving the “true” conflict, in accordance with the present invention. By determining “true” conflicts in the manner described in the present invention, users do not receive unhelpful conflict messages and do not need to intervene each time both the mobile data object and the corresponding server data change. [0034] [0034]FIG. 5 is a logical flow diagram generally illustrating an overview of a synchronization process having a conflict resolution process for resolving conflicts detected during a synchronization session. Briefly, the overview of the synchronization process shown in FIG. 5 detects whether a potential conflict, in accordance with the present invention, may exist and the manner in which the potential conflict is resolved during the synchronization process. The synchronization process with conflict resolution 500 begins at block 501 , where a synchronization session has been initiated and both the mobile device 320 and the information server 320 have sent client synchronization data 330 and server synchronization data 350 to the synchronization application 342 , respectively. The synchronization application 342 has passed the client synchronization data 330 and server synchronization data 350 to the conflict manager 380 for conflict processing. Processing continues at blocks 502 and 504 . [0035] At blocks 502 and 504 , the conflict manager 380 gets one of the mobile data objects 324 (block 502 ) and a corresponding server data object 314 ( 504 ). [0036] At block 506 , the conflict manager 380 checks the change indicator 404 associated with the corresponding server data object 314 to determine whether any changes have been made to the server data object 314 . [0037] At decision block 508 , if the change indicator 404 associated with server data object 314 indicates that the server data object 314 is not “dirty” (i.e., no changes were made to any properties associated with the server data object 314 ), the process continues at block 510 . [0038] At block 510 , the conflict manager 380 checks the change indicator 404 associated with the mobile data object 324 to determine whether any changes have been made to the mobile data object 324 . [0039] At decision block 512 , if the change indicator 404 associated with the mobile data object 324 indicates that the mobile data object 324 is not “dirty” (i.e., no changes were made to any properties associated with the mobile data object 324 ), the mobile data object 324 and the server data object 314 are not synchronized because neither data object had updates. In one embodiment, either the mobile data object 324 or the server data object 314 will be “dirty”. This reduces the amount of data transmitted in the synchronization data because it insures at least one of the data objects has changed. If the mobile data object 324 is not “dirty” at decision block 512 , processing continues at decision block 514 . [0040] At decision block 514 , the conflict manager 380 determines whether there are any more mobile data objects 324 and corresponding server data objects 314 . If some data objects 314 , 324 still remain to be processed, the process loops back to block 502 and proceeds as described above. However, once all the data objects 324 314 have been processed, the conflict resolution processing within the synchronization process is complete and the process ends at end block 516 . [0041] Now, returning to decision block 508 , if the conflict manager 380 determines that the server data object is “dirty”, processing continues at block 518 and then to decision block 520 . At block 518 , the conflict manager 380 checks the change indicator 404 associated with the mobile data object 324 to determine whether any changes have been made to the mobile data object 324 . At decision block 520 , if the change indicator 404 associated with the mobile data object 324 indicates that the mobile data object 324 is not “dirty” (i.e., no changes were made to any properties associated with the mobile data object 324 ). If the mobile data object 324 is not “dirty”, this indicates that only one of the data objects is “dirty”. Thus, the data objects 314 324 may be synchronized using any well-known synchronization technique without performing the conflict resolution process of the present invention. Typically, the synchronization provided in block 522 attempts to update both data objects 314 324 to have identical information. Block 522 is also entered after a determination is made at decision block 512 that only the mobile data object 324 is “dirty”. Again, because only one of the data objects is “dirty”, synchronization is provided without performing the conflict resolution process of the present invention. [0042] However, if both data objects 314 324 are “dirty”, as determined at decision blocks 508 and 520 , processing continues to block 524 . Briefly, at block 524 , the conflict manager determines the extent of the conflict between the mobile data object 324 and the server data object 314 and attempts to resolve the conflict with as little user intervention as possible. A detailed description of the conflict resolution process is illustrated in FIG. 6 and described below. Processing then continues to decision block 514 and proceeds as described above. [0043] [0043]FIG. 6 is a logical flow diagram illustrating one embodiment of a conflict resolution process 600 suitable for use in FIG. 5. The conflict resolution process 600 begins at block 601 , after the conflict manager 380 has determined that there is a conflict between a mobile data object 324 and a corresponding server data object 314 . Processing continues at decision block 602 . [0044] At decision block 602 , a determination is made whether the change indicator 404 indicates that the server data object 324 was “dirty” because the server data object 314 has been deleted. If the server data object 314 has been deleted, processing continues to block 604 . At block 604 , the conflict manager instructs the synchronization application 342 (FIG. 3) to delete the corresponding mobile data object 324 . The synchronization application 342 may then include the appropriate information in the client synchronization data 330 sent to the mobile device 320 at some later time. The synchronization application may include the information in the current synchronization session or in a later synchronization session. Processing continues to return block 606 and back to FIG. 5. [0045] Returning back to decision block 602 , if the server data object 314 has not been deleted, processing continues to decision block 608 . At decision block 608 , a determination is made whether the change indicator 404 for the mobile data object 324 indicated that the mobile data object 324 was “dirty” because the mobile data object 324 has been deleted. If the mobile data object 324 has not been deleted, processing continues at block 610 . At block 610 , the conflict manager instructs the synchronization application 342 (FIG. 3) to delete the corresponding server data object 314 during one of the synchronization sessions. Processing continues to return block 606 and back to FIG. 6. [0046] Returning back to decision block 608 , if the mobile data object 324 has not been deleted, processing continues at block 612 . At block 612 , the properties of the mobile data object 324 and the server data object 314 that were designated as syncable properties are compared. As mentioned earlier, by specifying only certain of the properties as syncable properties 406 , the present invention decreases the number of conflicts that are reported compared to prior conflict resolution methods. In addition, the conflict resolution process, in accordance with the present invention, is able to automatically resolve these “true” conflicts based on the syncable properties without user intervention in certain situations. Processing continues to decision block 614 . [0047] At decision block 614 , a determination is made whether any of the syncable properties indeed differ. If none of the syncable properties differ, processing continues to block 616 , where the change indicator 404 for both the mobile data object 324 and the server data object 314 are reset to indicate that the corresponding object is not “dirty.” Thus, in accordance with the present invention, the user of the mobile device 320 does not receive an unintelligible conflict message due to changes in the data objects 314 324 that do not warrant user concern. For example, if only the “Read” property has been changed from unread to read on both objects, even though both messages are “dirty,” the information is the same and the user need not be informed. Processing continues to return block 606 and back to FIG. 6. [0048] Returning back to decision block 614 , if it is determined that syncable properties differ, processing continues to decision block 618 , where the syncable property is retrieved. [0049] At block 620 , a determination is made whether all the syncable properties that differ can be resolved using the simple merge process. This determination is based on whether the syncable properties that differ are also designated as mergeable properties 408 (FIG. 4) in the data objects. If any of the syncable properties that differ are designated as a mergeable property, the process continues at block 624 . [0050] At block 624 , a simple merge process is performed. In accordance with the present invention, each property designated as a mergeable property has an associated pre-determined preferred state for the property. In one embodiment, the preferred state is related to the likelihood that vital information would be lost if the property of the data object was not changed to the preferred state. In another embodiment, the user on the mobile device may specify the preferred state for the property designated as a mergeable property. During the simple merge process the preferred state for the property is pushed to the data object with the property in a state different than the preferred state. A beneficial effect on resolving the conflict using the simple merge process is that the user is not inconvenienced by an unintelligible conflict message that requires user-intervention and that the user does not lose vital information. Below are two tables summarizing the outcome of processing from block 624 . Table 1 summarizes the simple merge process (block 624 ) for conflicting email objects in which “UNREAD” is the preferred state. Table 2 summarizes the simple merge process (block 624 ) for conflicting appointment objects in which “POSTPONE” or “POSTPONE to earliest time” is the preferred state. TABLE 1 Starting State User Action State After Change Simple Merge Changes (Synched) (Disconnected) (Disconnected) (N/C = No Change) Server Device Server Device Server Device Server Device READ READ Marks Mail Marks Mail UNREAD READ UNREAD, Change to As As N/C UNREAD; UNREAD UNREAD, Send conflict then READs status to device mail READ READ Marks Mail Marks Mail READ READ READ, N/C READ, N/C As As UNREAD, UNREAD, then then READs READs it it READ READ Marks Mail Marks Mail READ UNREAD Change to UNREAD, N/C As As UNREAD UNREAD, UNREAD then READS it UNREAD UNREAD READs READs UNREAD READ UNREAD, Change to mail then Mail N/C UNREAD; Marks As Send conflict UNREAD status to device UNREAD UNREAD READs READs UNREAD UNREAD UNREAD, UNREAD, N/C mail, then mail, then N/C Marks As Marks As UNREAD UNREAD UNREAD UNREAD READs READs READ UNREAD Change to UNREAD, N/C Mail mail, then UNREAD Marks As UNREAD [0051] [0051] TABLE 2 Starting State User Action Simple Merge Action Performed (Synched) (Disconnected) (N/C = No Change) Server Device Server Device Server Device Reminder Reminder Dismiss Dismiss N/C N/C ON ON Reminder Reminder Dismiss Postpone for Change to N/C ON ON X minutes Postpone for X Minutes Reminder Reminder Postpone for Dismiss N/C Change to Postpone ON ON X minutes for X Minutes; send conflict property to device Reminder Reminder Postpone Postpone N/C N/C ON ON until X:00. until X:00. Reminder Reminder Postpone Postpone Sync the Sync the change that ON ON until X:00. until Y:00. change that re- reminds the user the minds the user earliest; send the earliest. conflict property to device. [0052] After the simple merge process is completed, processing continues at block 626 . [0053] At block 626 , a conflict notification for the above syncable property is prepared. As described earlier, the conflict notification provides sufficient information that the mobile device 320 may display a user interface with the information if desired. In one embodiment, only the property causing the conflict is sent to the mobile device rather than the entire data object. Processing continues to return block 606 and back to FIG. 5. [0054] Returning to decision block 620 , when all the syncable properties that differ cannot be resolved using a simple merge process, processing continue to block 622 . At block 622 , a user-selectable conflict resolution process is performed based on a conflict resolution method selected by the user of the mobile device 320 . Briefly, in one embodiment, a user may request one of three conflict resolution methods: client wins, server wins, or keep both. The user of the mobile device 320 selects the method using one of the input devices 112 available on the mobile device, such as a keypad. The appropriate program module 106 will then include the parameter 322 that specifies the selected method within the synchronization data 330 sent to the synchronization application 342 . The synchronization application 342 will provide the parameter 332 to the conflict manager 380 . The technique used to specify the selected method for conflict resolution and pass the information to the conflict manager 380 may be achieved using various techniques known with the art and which do not involve undue experimentation. The user-selectable conflict resolution is illustrated in FIG. 7 and described below in detail. Processing continues to return block 606 and back to FIG. 5. [0055] [0055]FIG. 7 is a logical flow diagram illustrating one embodiment of a user-selectable conflict process 700 suitable for use in FIG. 6. The user-selectable conflict resolution process 700 begins at block 701 , after there has been a determination that a simple merge process is not available for resolving the conflict between the mobile data object 324 and the corresponding server data object 314 . Processing continues at decision block 702 . [0056] At block 702 , a determination is made whether the user of the mobile device 320 chose the “client wins” method. If the “client wins” method was chosen, processing continues at block 704 . At block 704 , the server data object 314 is replaced with the mobile data object 324 . One skilled in the art will appreciate that the replacement of the data object may occur immediately or at some later time during the synchronization session or a later synchronization session. Processing continues to return block 718 and back to FIG. 6. [0057] Returning to block 702 , if the user did not chose the “client wins” method, processing continues to decision block 706 . At decision block 706 , a determination is made whether the user selected the “server wins” method. If the “server wins” method is chosen, processing continues to blocks 708 and 710 . At block 708 , a copy of the server data object 314 is sent to the mobile device 320 . At block 710 , the mobile data object 324 is replaced with the server data object 314 . Again, the actual replacement of the mobile data object 324 may occur at anytime during the synchronization session or may occur during a later synchronization session. Processing continues to return block 718 and back to FIG. 6. [0058] Returning to block 706 , if the user did not chose the “server wins” method, the default method “keep both” is performed. Processing continues at blocks 712 - 714 . At block 712 , a copy of the server data object 314 is sent to the mobile device 320 . At block 714 , the prior mobile data object 324 is sent to the server as a new data object during the next synchronization session. Processing continues to return block 718 and back to FIG. 6. [0059] The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.

A system and method is described for resolving a conflict detected while synchronizing a first data object in a first store associated with a mobile device and a second data object in a second store associated with a server. Once the conflict is detected, properties of the first data object are compared with corresponding properties of the second data object. If the properties and the corresponding properties that differ are designated as mergeable properties, the properties and the corresponding properties are merged. Merging the properties involves sending a preferred state associated with each of the properties and the corresponding properties to the mobile device and the server for updating the first data object and second data object, respectively, when an initial state for the properties and the corresponding properties is different than the preferred state. The preferred state is based on a likelihood that vital information would be lost if the preferred state did not replace the initial state of the property or the corresponding property. The merging is performed without user-intervention on the mobile device. In addition, the entire first data object or second data object is not sent to the mobile device to achieve the merge, thereby minimizing the data transfer to the mobile device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat commutator including conductive carbon elements and more particularly to such a flat commutator for use in a motor for a fuel pump utilized in a fuel tank of an automobile or the like. 2. Description of the Prior Art In general, fuel pumps have been used in automotive applications to supply liquid fuel contained in a fuel tank to the engine, and such fuel pumps are arranged in the fuel tanks. On the other hand, due to a rising cost of normal fuel and an increased consideration for environmental contamination, there has been noticed a new fuel containing an oxygen compound, such as methyl alcohol and ethyl alcohol, etc. Therefore, when the fuel pump is used in the fuel tank containing such a fuel and if such a fuel pump includes a motor including a metallic commutator, it will corrode by the above mentioned alcohol contained in the fuel, so that the life of the motor is shortened. Under such a circumstance, a commutator which includes conductive carbon elements has been developed. Such prior art commutators including the above mentioned conductive carbon elements are disclosed in U.S. Pat. Nos. 5,157,299 and 5,175,463 and in Japanese Utility Model Publication No. 2-53260. Among these documents, U.S. Pat. No. 5,157,299 discloses a structure wherein carbon segments are connected to a metallic segment support through an adhesive layer of solder. U.S. Pat. No. 5,175,463 discloses a structure wherein segments are attached on a base through the intermediary of a first conductive layer of material such as nickel, copper, etc. and a second conductive layer of material such as gold, silver, etc. JUMP No. 2-53260 discloses a structure wherein a hub body is mechanically and electrically connected to carbon segments partially shaped to be of particular configuration. In U.S. Pat. Nos. 5,157,299 and 5,175,463, however, there is no consideration of the strength of the commutator against a stress caused therein during its rotation, although suitable conductivity can be obtained in either case. In addition, the commutator disclosed in JUMP No. 2-53260 is not always shaped to have a simple configuration, so that manufacture thereof is not easy. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a commutator of simple structure which does not cause the life thereof to be shortened if a fuel containing an oxygen is used. This object of the invention is accomplished by provision of a flat commutator comprising a plurality of carbon segments each of which has a sectorial configuration, the carbon segments being made of conductive carbon material and defining a commutating surface of the commutator. The carbon segments are attached to respective metallic segments and are arranged circularly. Each metallic segment has fixing members that encroach onto inner and outer peripheral surfaces of the respective carbon segment, thereby fixing the carbon segment on the metallic segment. A hub body of synthetic resin encloses at least fixed portions of the inner and outer peripheral surfaces of the carbon segments that engage with the fixing members of the metallic segment. With this arrangement, since the carbon segments are engaged with the metallic segments through the fixing members which encroach upon the inner and outer peripheral surfaces of the carbon segments, the carbon segments can be fixed to the metallic segments rigidly and the appropriate conductivity therebetween can be attained. In addition, since the fixed portions of the carbon segments which are fixed by the fixing members of the metallic segment are enclosed in the hub body of synthetic resin, the fixed portions are not eroded even under conditions of use of fuel containing oxygen, and thus stable conductivity can be obtained. Further, if enclosing is achieved by use of a synthetic resin, the carbon segments will be supported more rigidly by the metallic segments. Preferably, in the above commutator, the fixed portions comprises recesses formed in the inner and outer peripheral surfaces of the carbon segments. In such a case, due to provision of the recesses, the positioning of the fixing members on the carbon segments can be ensured so that a deviation thereof relative to the metallic segments in the circumferential direction of the carbon segments can be prevented. In the present invention, preferably the metallic segment has a plurality of engagement members formed around the inner fixing members. In such case, provision of the engagement pieces ensures integration the metallic segment with the hub body. Further, in the present invention each metallic segment is provided on an outer periphery thereof with a connection terminal which projects radially outwardly of the metallic segment. The commutator according to the present invention is manufactured by a method comprising providing a base member having engagement portions formed on inner and outer peripheral surfaces thereof, the base member being made of conductive carbon in the form of a circular plate body, and providing a metallic plate member having a bottom face substantially identical to a bottom face of the base member, the metallic plate member further including connection terminals projecting from an outer periphery thereof and fixing members extending upwardly from inner and outer peripheries thereof. The base member is press-fit to the metallic plate member so that the fixing members encroach into the engagement portions of the base member. The engagement portions of the base member which are supported by the metallic plate member are enclosed with synthetic resin, thereby forming a synthetic resin hub body. Slits are formed in the base member and the metallic plate member to separate them into a plurality of segments so that each of the segments contains at least one pair of the engagement portions on the inner and outer peripheries of the base member, respectively. By the operations of press-fitting the base member to the metallic plate member so that the fixing members encroach into the respective engagement portions of the base member, sequently enclosing the engagement portions of the base member with the synthetic resin, and then forming slits in the base member and the metallic plate member, the commutator can be manufactured easily. Furthermore, since, at the engagement portions formed on inner and outer peripheral surfaces of the base member, the carbon segments and the metallic segments constituting the segments obtained by provision of the slits are fixed to each other in a stable and rigid condition, the segments can be supported stably in opposition to centrifugal force acting thereon when using the commutator. Thus, it is possible to maintain stable operation for a long period of time. Other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a commutator of the present invention, in which a part thereof is cut away; FIG. 2 is an exploded perspective view of a base member of a conductive carbon element and a metallic plate member, as constituents of carbon segments and metallic segments, and which are used for production of the commutator of FIG. 1; FIG. 3 is a perspective view showing a condition wherein the plate member is secured to the base member during production of the commutator of the present invention; and FIG. 4 is an enlarged perspective view showing fixing surfaces of fixing members of the plate member for fixing to the base member. DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention is now described with reference to the drawings. FIG. 1 is a perspective view of a commutator of the present invention, in which a part thereof is cut away to clarify an inside structure of the commutator. FIG. 2 is a perspective view of a base member 11 of a conductive carbon element and a metallic plate member 12 in a disassembled state, as constituents of carbon segments and metallic segments of the commutator of the invention. In an assembled state shown in FIG. 1, carbon segments 1 made of a conductive carbon material, each of which has a sectorial top face, are arranged in a circular manner spaced by respective slits 2 so as not to be in contact with each other. Further, each of the carbon segments 1 is provided on inner and outer peripheries thereof with projecting rims 3 which are located in the vicinity of lower ends of the respective peripheries. Provided under each of the carbon segments 1 is a respective metallic segment 4 which is made of a suitable material such as copper or the like. The segment 4 is provided at inner and outer peripheral ends thereof with fixing members 5 which extend upwardly therefrom. The fixing members 5 encroach or fit into recesses 6 formed in the respective projecting rims 3, so that it is possible to ensure not only electrical conductivity between each carbon segment 1 and the respective metallic segment 4, but also fixing of the carbon segments 1 on the respective segments 4 in the circumferential, diametrical and axial directions thereof. FIG. 4 shows fixing faces of outer fixing members 5 of plate member 12 to form one metallic segment 4. In the illustrated embodiment, a large number of irregularities are formed on the fixing face of each fixing member 5 so as to increase the area of engagement thereof with the respective carbon segment 1. Furthermore, as shown in FIG. 1, the carbon segments 1 and the metallic segment 4 are covered inside of respective inner peripheral ends thereof, outside of respective outer peripheral ends thereof and beneath the segments 4 with a non-conductive hub body 7 which is made of synthetic resin. The metallic plate member 12 includes a plurality of engagement members 8 in order to ensure an integration thereof with the hub body 7 and further includes a plurality of connection terminals 9 formed on an outer periphery thereof. The commutator of the invention is produced as follows. At first, as shown in FIG. 2, base member 11 of conductive carbon material is formed so as to be a circular plate member having projecting rims 3 integrally formed on inner and outer circumferential surfaces and in vicinities of respective lower edges thereof. Next, to provide for engagement with the fixing members 5 of the metallic plate member 12, recesses 6 are regularly formed on the respective rims 3 by cutting away material of the rims 3 at intervals by suitable cutting means. Alternatively, the recesses 6 and the rims 3 may be simultaneously formed by pressing, at the stage of manufacture of the circular base member 11. Further, the recesses 6 need not always be formed so as to have smooth surfaces in comparison with other surfaces of the base member 11. That is, if recesses 6 are formed with uneven surfaces, areas of engagement of the base member 11 with the fixing members 5 would be increased, thereby allowing conductivity and mechanical integration between the base member 11 and metallic plate member 12 to be increased. On the other hand, by a stamping operation or the like, metallic plate member 12 to form the metallic segments 4 is formed as to be of a circular shape and to have the fixing members 5 extending from inner and outer peripheries thereof at locations corresponding to respective recesses 6. At such stamping stage, the above-mentioned engagement members 8 are formed around the inner fixing members 5, and the connection terminals 9 are formed to project radially outwardly from the outer periphery of the member 12. Next, after positioning the respective recesses 6 of the base member 11 in alignment with the respective fixing members 5 of the plate member 12, the base member 11 is engaged with the plate member 12 by suitable means, such as press-fitting, so that an assembly as shown in FIG. 3 is formed. Thereafter, the non-conductive hub body 7 made of a suitable material such as synthetic resin or the like is formed integrally with such assembly so as to form a central portion into which an output shaft of a motor (not shown) can be inserted at the inside of the assembly and to extend around the outside of the assembly and under the metallic plate member 12. In this way, the integration of the base member 11 with the plate member 12 can be improved, whereby conductivity therebetween through the fixing members 5 further is improved. In addition, since also the engagement members 8 of the plate member 12 are surrounded by and embedded in the synthetic resin when molding the hub body 7, the plate member 12 is fixed securely to the hub body 7. Next, the slits 2 are formed in the thus formed commutator body to extend from a top face of the base member 11 downwardly to a level somewhat below the underside of the plate member 12. The commutator thus is completed. When the connection terminals 9 or bent, e.g. as shown in FIG. 1, since all contact between the carbon segments 1 and the metallic segments 4 are sealed in the synthetic resin, stable conductivity can be maintained over a long period of use. Furthermore, due to press-fitting of the fixing members 5, fixing attachment between the carbon segments I to the metallic segments 4 can be executed easily and maintained stably. According to the invention, the fixing members 5 have only to serve to fix the carbon segments 1 to the metallic segments 4 under conditions that each carbon segment 1 is clamped between the respective fixing members 5. It will be understood by those skilled in the art that the present invention is not limited to the aforementioned embodiment in terms of configuration, number, and position of the metallic segments, etc. Further, irregularities on back faces of the fixing members 5 other than those illustrated may be employed in terms of configuration, position and size, without departing from the object of increasing the area of engagement of the members 5 with the carbon segments 1. Although the projecting rims 3 are formed on both inner and outer peripheries of the carbon segments 1 in the shape of the bands, the configuration thereof is not limited to such illustrated embodiment. Finally, it will be understood by those skilled in the art that the invention is not limited to the forgoing description of the embodiment of the disclosed commutator, and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention.

A flat commutator includes a circular arrangement of sectorial carbon segments made of conductive carbon providing commutating surface of the commutator, metallic segments attached to respective of the carbon segments, and a hub body of synthetic resin. The metallic segments have fixing members encroaching into inner and outer peripheral surfaces of the carbon segments, thereby fixing the carbon segments to the metallic segments. The hub body encloses at least fixed portions of the inner and outer peripheral surfaces of the carbon segments that engage with the fixing members of the metallic segments.

FIELD OF THE INVENTION The present invention relates to polypeptides encoded by Rhodococcus ( Corynebacterium ) equi ( R. equi ), compositions including such polypeptides (Rpl) and antibodies to such polypeptides, which can be useful in the treatment of animals, specifically horses and foals, to minimise infection of animals, by R. equi . The invention further relates to methods of detection of R. equi using polypeptides (Rpl), antibodies with binding specificity to said polypeptides or nucleic acids or the like with binding specificity to nucleic acids encoding such polypeptides using, for example, PCR. BACKGROUND TO THE INVENTION Rhodococcus equi is a Gram-positive, facultative intracellular coccobacillus classified in the order of Acitnomycetales. It is primarily a soil organism. It has been recognised as a positive agent of a debilitating and potentially fatal bronchopneumonia affecting foals worldwide. R. equi is considered to be one of the most significant pathogens in the equine breeding industry. The successful early diagnosis and treatment of Rhodococcus equi in foals and management of the foals environment to reduce the risk of contracting the disease are, arguably, among the most challenging experiences currently facing equine stud farms. Presently the treatment of R. equi disease is by the prolonged administration of a combination of antimicrobials, macrolides, i.e. erythromycin, azithromycin or clarithromycin, and rifampicin. However, as this therapy risks antibiotic resistance and adverse drug reactions in the foal and the dam, improved means of therapy and prophylactic treatment are required. R. equi can also affect non-equine species. In pigs R. equi is associated with granulomatous lymphadenitis of cervical lymphatic tissue and in man R. equi can cause cavitary pneumonia, predominantly in immunocompromised individuals especially those with acquired immune deficiency syndrome (AIDS). As a consequence of the AIDS pandemic, R. equi pneumonia has become a disease of increasing significance in human medicine. R. equi infections have also been described in cattle, sheep, goats, lama, cats and dogs, but disease in these species is rare with lesions confined to lymph node abscessation or wound infection. Infection by R. equi relies on the ability of R. equi to colonise the airways and replicate inside macrophages which is dependent on its capacity to interfere with endosomal maturation following phagocytosis and to prevent acidification of the vacuole in which it resides. Eventually, intracellular proliferation of the pathogen leads to the necrotic death of the marcophages accompanied by massive damage to lung tissue characterised by cavitation and granuloma formation. Studies of the virulent strains of R. equi have determined that such strains possess an extra chromosomal DNA element known as a plasmid, which is associated with virulence. Plasmids isolated from regular strains infecting foals have been proposed to include a region that represents a pathogenicity island, which is a DNA fragment containing genes required for virulence. The pathogenicity island identified contains a family of nine virulence associated protein (Vap) chains (VapA-VapC-Vap-I, pseudo-VapE). Killed/inactivated R. equi organisms do not illicit protective immunity, and there is no consistent evidence that protein or DNA vaccines, based on the highly immunogenic VapA surface antigen, are efficacious in producing protection against a Rhodococcal pneumonia in foals. In view of the lack of an efficacious vaccine, R. equi infection is a major cause of mortality in young foals and the heavy economic losses incurred due to R. equi has a major economic impact in countries where thoroughbred racing and breeding is important (USA, Australia, Ireland, Argentina, UK, France, Spain, Germany, Austria, Japan etc.). There is a need for treatment regimes and a vaccine to be developed which can be used to control R. equi on farms, in particular stud farms. SUMMARY OF THE INVENTION The inventors have determined a novel diagnostic marker and vaccine candidate for Rhodococcus equi in horses and other susceptible species and treatment means. Specifically, the inventors have identified a rpl pathogenicity island that differs from the yap pathogenicity island and the inventors have determined the rpl pathogenicity island, in particular RplB, encodes a major adhesion factor of R. equi which enables host colonisation. The proteins (Rpl) encoded by the rpl pathogenicity island are considered to be major immunodominant antigens. The inventors have further determined that the rpl pathogenicity island is absent from non-pathogenic Rhodococcus species. These findings allow the use of probes to proteins or nucleic acid of the rpl pathogenicity island and antibodies with binding specificity to the proteins encoded by the rpl pathogenicity island in methods of detection of R. equi . Further, it enables the use of nucleic acids encoding proteins or proteins of the rpl pathogenicity island as immune system modulators, in particular to provoke a protective immune response to subsequent antigen challenge in an animal. Accordingly, a first aspect of the invention provides at least one immunogenic R. equi polypeptide having an amino acid sequence, encoded by a polynucleotide sequence comprising a polynucleotide sequence of a gene selected from a gene as listed at table one, or a fragment, derivative or variant of such a polypeptide. TABLE ONE Proposed function of SEQ rpl encoded Position in R. equi ID locus Identifier protein 103S NO rplA REQ_18350 Prepilin Position 1938280-1939068 1 peptidase (complement) in 103S genome rplB REQ_18360 Pilin subunit Position 1939395-1939601 2 in 103S genome rplC REQ_18370 Minor pilin Position 3 protein 1939683.-1940084 in 103S genome rplD REQ_18380 Putative Position 1940093-1941037 4 lipoprotein 1940084 in 103S genome rplE REQ_18390 Pilus assembly Position 1941047-1941784 5 protein in 103S genome rplF REQ_18400 Pilus assembly Position 1941781-1942980 6 ATPase in 103S genome rplG REQ_18410 Secretion Position 1942977-1944374 7 apparatus in 103S ATPsae genome rplH REQ_18420 Secretion Position 1944371-1946239 8 apparatus in 103S integral genome membrane protein rplI REQ_18430 Secretion Position 1946262-1947152 9 apparatus in 103S integral genome membrane protein In embodiments of the invention, the polypeptide or derivative or variant or fragment thereof can be encoded by a polynucleotide sequence comprising a polynucleotide sequence of a gene as listed in Table 2 TABLE TWO Proposed function of SEQ rpl encoded Position in R. equi ID locus Identifier protein 103S NO rplA REQ_18350 Prepilin Position 1938280-1939068 1 peptidase (complement) in 103S genome rplB REQ_18360 Pilin subunit Position 1939395-1939601 2 in 103S genome rplC REQ_18370 Minor pilin Position 3 protein 1939683.-1940084 in 103S genome rplD REQ_18380 Putative Position 1940093-1941037 4 lipoprotein 1940084 in 103S genome rplE REQ_18390 Pilus assembly Position 1941047-1941784 5 protein in 103S genome rplH REQ_18420 Secretion Position 1944371-1946239 8 apparatus in 103S integral genome membrane protein rplI REQ_18430 Secretion Position 1946262-1947152 9 apparatus in 103S integral genome membrane protein In particular embodiments the polypeptide or a derivative or variant or fragment thereof can be encoded by a polynucleotide sequence comprising a polynucleotide sequence of a gene selected from rplB (SEQ ID NO 2), rplC (SEQ ID NO 3), or rplD (SEQ ID NO 4). In an alternative embodiment, the polypeptide or a derivative can be encoded by a polynucleotide sequence comprising a polynucleotide sequence of a gene selected from rplB (SEQ ID NO 2), rplA (SEQ ID NO 1) or rplE (SEQ ID NO 5). In embodiments of the invention, the polypeptide or a derivative or fragment thereof is encoded by a polynucleotide sequence comprising a polynucleotide sequence of a gene selected from the list of genes of Table 1, more preferably selected from the list of genes of Table 2. In embodiments of the invention, the polypeptide or a derivative or fragment or variant thereof is encoded by a polynucleotide sequence consisting essentially of or consisting of a polynucleotide sequence of a gene selected from the list of genes of Table 1, more preferably selected from the list of genes of Table 2. In embodiments, the polypeptide is encoded by a polynucleotide sequence comprising the polynucleotide sequence of a gene encoding Rpl pilin ATGAACCTCTTCTTCGCGAACCTGTACCTCATGGGCTTAGACGTCAA GGACCGTCTGACCCGTGACGACCGCGGCGCCACTGCGGTCGAGTAC GGACTGATGGTCGCCGGCATCGCGATGGTGATCATTGTTGCGGTTTT CGCCTTCGGCGATAAGATTACCGACCTCTTCGATGGCTTCAACTTCG ACGATCCCGGCGGCGAGTAG (SEQ ID NO 2). In embodiments, the polypeptide is encoded by a polynucleotide sequence consisting essentially of or consisting of the polynucleotide sequence of a gene encoding Rpl pilin ATGAACCTCTTCTTCGCGAACCTGTACCTCATGGGCTTAGACGTCAA GGACCGTCTGACCCGTGACGACCGCGGCGCCACTGCGGTCGAGTAC GGACTGATGGTCGCCGGCATCGCGATGGTGATCATTGTTGCGGTTTT CGCCTTCGGCGATAAGATTACCGACCTCTTCGATGGCTTCAACTTCG ACGATCCCGGCGGCGAGTAG (SEQ ID NO 2). In embodiments, the polypeptide is encoded by a polynucleotide sequence comprising a fragment of the polynucleotide sequence of a gene encoding Rpl pilin ATGAACCTCTTCTTCGCGAACCTGTACCTCATGGGCTTAGACGTCAA GGACCGTCTGACCCGTGACGACCGCGGCGCCACTGCGGTCGAGTAC GGACTGATGGTCGCCGGCATCGCGATGGTGATCATTGTTGCGGTTTT CGCCTTCGGCGATAAGATTACCGACCTCTTCGATGGCTTCAACTTCG ACGATCCCGGCGGCGAGTAG (SEQ ID NO 2) wherein the polypeptide encoded by the fragment is a biologically active immunogenic fragment of a polypeptide encoded by the polynucleotide sequence comprising the polynucleotide sequence of the gene encoding Rpl pilin ATGAACCTCTTCTTCGCGAACCTGTACCTCATGGGCTTAGACGTCAA GGACCGTCTGACCCGTGACGACCGCGGCGCCACTGCGGTCGAGTAC GGACTGATGGTCGCCGGCATCGCGATGGTGATCATTGTTGCGGTTTT CGCCTTCGGCGATAAGATTACCGACCTCTTCGATGGCTTCAACTTCG ACGATCCCGGCGGCGAGTAG (SEQ ID NO 2). In embodiments, a derivative or fragment or variant can be an immunogenic derivative or fragment or variant that can provide an immune response in which antibodies with binding specificity to at least one of SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8, and 9 are generated for example antibodies cross-reactive to the biologically active immunogenic fragment and at least one of SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8 and 9. In particular embodiments such fragments, derivatives or variants can functionally provide a pilus in R. equi . Such derivatives, fragments or variants can be biologically active derivatives, fragments or variants. In embodiments the Rpl pilin polypeptide (RplB) can comprise an amino acid sequence MNLFFANLYLMGLDVKDRLTRDDRGATAVEYGLMVAGIAMVIIVAVFAFG DKITDLFDGFNFDDPGGE (SEQ ID NO 10). In embodiments, a polypeptide of the invention can consist of an amino acid sequence MNLFFANLYLMGLDVKDRLTRDDRGATAVEYGLMVAGIAMVIIVAVFAFG DKITDLFDGFNFDDPGGE (SEQ ID NO 10). In embodiments a polypeptide of the invention can comprise DKITDLFDGFNFDDPGGE (SEQ ID NO 11) or can be a variant thereof wherein such variant has at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10 amino acids different to that of SEQ ID NO 11. Substituted amino acids may suitably be conservative or non conservative amino acids. Alternatively, the variant may include insertions or deletions. Suitably, in embodiments a variant can demonstrate analogous biological function as a RplB pilin subunit or SEQ ID NO 11. In embodiments, a conserved variant may be provided by amino acid sequences comprising DKITDLFDGFNFDDPGGE (SEQ ID NO 11) wherein amino acids as shown are replaced by amino acids which are structurally conservative. For example, an aliphatic amino acid (alanine, serine, valine, leucine, isoleucine or the like) can be substituted with another suitable aliphatic amino acid, a hydrophobic amino acid (tyrosine, phenylalanine, tryptophan) can be substituted by another hydrophobic amino acid or a charged amino acid can be substituted by another charged amino acid. In such conserved variants, additional amino acids may be substituted. In embodiments a polypeptide of the invention can comprise the amino acid sequence DKITDLFDGFNFDDPGGE (SEQ ID NO 11). In embodiments a polypeptide of the invention consists of, or consists essentially of the amino acid sequence DKITDLFDGFNFDDPGGE (SEQ ID NO 11). A polypeptide of the invention may be provided using recombinant means or may be a synthetic polypeptide or may be extracted from R. equi bacteria, R. equi culture supernatant or from biological material infected with R. equi . In embodiments an isolated immunogenic polypeptide of the invention is expressed at the bacterial cell surface of a R. equi , or is secreted from R. equi. In embodiments, a polypeptide of the invention, or a fragment, derivative or variant thereof comprises an amino acid sequence of at least one polypeptide selected from the group consisting of the list provided by Table 3 or as set out in the sequences of FIG. 9 . TABLE THREE Rpl protein Identifier Proposed function SEQ ID NO RplA REQ_18350 Prepilin peptidase 12 product RplB REQ_18360 Pilin subunit 13 product RplC REQ_18370 Minor pilin protein 14 product RplD REQ_18380 Putative lipoprotein 15 product RplE REQ_18390 Pilus assembly 16 product protein RplF REQ_18400 Pilus assembly 17 product ATPase RplG REQ_18410 Secretion apparatus 18 product ATPsae RplH REQ_18420 Secretion apparatus 19 product integral membrane protein RplI REQ_18430 Secretion apparatus 20 product integral membrane protein All of the polypeptides shown in Table 3 are encoded in the rpl locus and are part of the R. equi Rpl pilus biogenesis machinery. In embodiments a polypeptide of the invention can be encoded by an R. equi . strain isolated from horses. In embodiments the polypeptide can be isolated from horses and can be from a virulent strain of R. equi . In embodiments, polypeptides of the invention can be made synthetically or recombinantly using techniques which are widely available in the art. The polypeptide of the invention may be optionally linked to an immunogenic carrier. Said immunogenic carrier may be a heterologous polypeptide, lipid, liposome, or another acceptable carrier molecule. Suitably, a polypeptide of the invention may be linked to the immunogenic carrier by chemical coupling or a polypeptide of the invention may be expressed as a fusion protein with the immunogenic carrier. A polypeptide of the invention, and/or a biologically active and/or immunogenic fragment, or derivative, or variant thereof, can be provided in an immunogenic composition, for example to raise antisera or monoclonal antibodies for passive immunisation, or as a vaccine. Alternatively, a polypeptide of the invention, fragment, derivative or variant thereof may be useful in an assay to detect antibodies specific for the polypeptide, including diagnostic assays. As set out herein, in embodiments, a derivative of a polypeptide of the invention can be a composite of specific polypeptide sequences of the invention, for example composites of SEQ ID NO 10, SEQ ID NO 11 and a polypeptide as set out in Table 3 or fragments thereof, or nucleotide sequences for example as set out at Table 1 or Table 2 disclosed herein. In embodiments, the nucleic acid sequences can be used to form concatemers and may be used to provide polypeptide sequences, for example relevant epitopes may be put in tandem or provided in multiples of 3, 4, 5, 6, or greater than 10, greater than 20 or more. Further, in embodiments a derivative can include a scrambled or chimeric polypeptide containing combinations of different relevant Rpl polypeptides. In such embodiments the combinations of relevant Rpl polypeptides can be provided in multiples of 2, 3, 4, 5, 6, or greater than 10, greater than 20 or more. It is important to note that even with knowledge of the genome of R. equi strain 103S, it would not be apparent that R. equi produced pili appendages or that the nine-gene locus encompassing nucleotide positions 1,938,280 to 1,947,152 (locus tags REQ18350-430) encoded a pilus biogenesis apparatus responsible for the production of R. equi pili involved in virulence and host colonisation. Pili are widespread among bacteria and can serve many functions unrelated to virulence. For example pili can facilitate attachment of bacteria to environmental surfaces such as soil particles, biofilm formation, be mediators of bacterial motility or enable adhesion to other bacteria. As will be appreciated, depending on pili function, in some instances, pili may not provide an immunogenic determinant suitable for vaccine development or be able to act as a diagnostic marker. Using visualisation by electron microscopy and genetic molecular analysis, the inventors demonstrated for the first that R. equi produces pili appendages or fimibriae, identified that the rpl locus R. equi encodes the pilus biogenesis apparatus, and further determined that proteins of R. equi pili are major virulence factors involved in host colonisation and that they are major immunodominant antigens. The latter determination would not have been suggested from sequence data alone. According to a second aspect of the present invention there is provided an isolated or recombinant nucleic acid encoding a polypeptide associated with pilus formation in R. equi . In embodiments of the invention there is provided an isolated or recombinant nucleic acid comprising a polynucleotide sequence comprising or consisting of a sequence as set forth in any one of SEQ ID NO 1, SEQ ID NO 2, SEQ ID NO 3, SEQ ID NO 4, SEQ ID NO 5, SEQ ID NO 6, SEQ ID NO 7, SEQ ID NO 8, and SEQ ID NO 9 or a variant or derivative or fragment thereof, for example as illustrated in the sequences of FIG. 10 . Due to the known degeneracy of the genetic code, a polynucleotide sequence which differs from those indicated by any one of SEQ ID 1, 2, 3, 4, 5, 6, 7, 8 or 9 can encode an active immunogenic derivative, variant or fragment and/or a biologically active derivative, variant or fragment of a polypeptide of the invention. In embodiments, a polynucleotide sequence which encodes such a derivative, fragment or variant sequence or an immunogenic biologically active derivative or fragment can result from silent mutations (e.g., occurring during PCR amplification), or nucleotide substitutions, deletions or insertions or the like or can be the product of deliberate mutagenesis of a native sequence. Variant polypeptides may be encoded by variant polynucleotide sequences having sequence homology (identity) of greater than at least 85%, 86%, 87%, 88%, 89%, preferably at least 90%, 91%, 92%, 93%, 94%, and more preferably 95%, 96%, 97%, 98%, 99% but less than 100% contiguous nucleotide sequence homology to any one of SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8, or 9 or fragments thereof. A variant polypeptide may be encoded by a polynucleotide sequence including nucleotide bases not present in the corresponding wild type nucleic acid molecule and/or internal deletions relative to the corresponding wild type nucleic acid molecule, such as SEQ ID NOs 1, 2, 3, 4, 5, 6, 7, or 8. Polynucleotide sequences encoding fragments of a polypeptide of the invention may be greater than 30 nucleotides in length, greater than 50 nucleotides in length, greater than 100 nucleotides in length, or greater than 150 nucleotides in length. The invention also provides isolated nucleic acids useful in the production of polypeptides. Suitably said biologically active immunogenic derivative, fragment or variant can elicit an immune response wherein the antibodies generated to said derivative, fragment or variant have a binding specificity to any one of SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8 or 9. In embodiments, there can be provided a polynucleotide sequence comprising or consisting of a sequence as set out in any one of SEQ ID NO 1, SEQ ID NO 2, SEQ ID NO 3, SEQ ID NO 4, SEQ ID NO 5, SEQ ID NO 6, SEQ ID NO 7, SEQ ID NO 8, and SEQ ID NO 9. In further embodiments there is provided an isolated or recombinant nucleic acid comprising a polynucleotide sequence comprising or consisting of a sequence as set forth in any one of SEQ ID NO 1, SEQ ID NO 2, SEQ ID NO 3, SEQ ID NO 4, SEQ ID NO 5, SEQ ID NO 8, and SEQ ID NO 9. In additional embodiments, there is provided an isolated or recombinant nucleic acid comprising a polynucleotide sequence comprising or consisting of a sequence as set forth in any one of SEQ ID NO 2, SEQ ID NO 3, and SEQ ID NO 4. In specific embodiments there is provided an isolated or recombinant nucleic acid comprising a polynucleotide sequence comprising or consisting of a sequence as set forth in SEQ ID NO 2. Polypeptides of the invention or a biologically active immunogenic fragment, derivative, or variant thereof may be prepared as a pharmaceutical preparation or composition. Such preparations will comprise the polypeptide or a biologically active immunogenic fragment, derivative, or variant thereof and a suitable carrier, diluent or excipient. These preparations may be administered by a variety of routes, for example, oral, buccal, topical, intramuscular, intravenous, subcutaneous, intranasal or the like. In a third aspect of the present invention, there is provided a composition comprising a polypeptide or antibody according to the invention, or a biologically active immunogenic fragment, derivative, or variant thereof, together with a pharmaceutically acceptable carrier. A carrier and/or excipient useful in a composition of the present invention will generally not inhibit to any significant degree a relevant biological activity of the polypeptide or antibody of the invention. Alternatively, or in addition, the carrier or excipient can comprise a compound that enhances uptake and/or delivery and/or efficacy of the polypeptide and/or antibody as described herein. Alternatively, or in addition, the carrier or excipient can comprise a compound that enhances the activity of a polypeptide and/or antibody as described herein and/or reduces inhibition of said polypeptide or antibody by degradative enzymes in the site of administration and/or on route to the site of action and/or at the site of action. For example, the carrier or excipient may comprise a protease inhibitor and/or a DNase inhibitor and/or an RNase inhibitor to thereby enhance the stability of a polypeptide and/or antibody as described herein above or nucleic acid encoding same. As will be apparent to the person skilled in the art based on the foregoing description, the methods of the present invention further comprise providing, producing or obtaining a composition comprising a polypeptide and/or an antibody or nucleic acid encoding said polypeptide. Suitable methods for producing such compositions will be apparent to the skilled artisan based on the disclosure herein. A polypeptide can also be delivered with other relevant antigens in a polyvalent protein vaccine. In certain further aspects, the present invention provides an antibody which has binding specificity to at least one of the polypeptides of the invention or a fragment, derivative, or variant thereof, or an antigen binding fragment of said antibody. Accordingly, in a fourth aspect of the invention there is provided an antibody which specifically binds to a polypeptide of the invention or an epitope, fragment, derivative or variant thereof. Antibodies of the present invention may confer protection against infection with R. equi . Additionally or alternatively, an antibody can specifically bind to a polypeptide of the invention or can bind to an epitope of the pili provided on R. equi or an R. equi antigen of the pili and whilst not conveying protection against infection with R. equi , may be a useful in an immunoassay for the detection of polypeptides of the invention or for diagnosis of R. equi infection. In certain embodiments, the antibody can be a polyclonal antibody. Alternatively, the antibody can be a monoclonal antibody, a chimeric antibody, or a synthesized or a synthetic antibody. Methods for producing a polyclonal and monoclonal antibodies are well known in the art and an antibody provided against a polypeptide of the pili is described herein. In certain further aspects, the present invention further extends to a method of producing an antibody which specifically binds to at least one polypeptide of the present invention, or a biologically active and/or immunogenic fragment, derivative or variant thereof, said method comprising: (i) immunising a host with a polypeptide or a fragment, derivative, or variant thereof as described herein according to any embodiment, and (ii) recovering antibodies generated by the host against said polypeptide or a fragment, derivative, or variant thereof. The present invention also provides a method for producing an antibody that binds to an antibody which specifically binds to at least one polypeptide of the present invention or a fragment, derivative, or variant thereof (i.e., a method for producing an anti-idiotypic antibody), said method comprising: (i) immunising a host with an antibody that binds to a polypeptide of the invention or a fragment, derivative, or variant thereof or an antigen binding fragment of said antibody, (ii) identifying antibodies generated by the host against an antigen binding site of said antibody; and (iii) recovering the antibodies identified at (ii). The present invention also provides an anti-idiotypic antibody that selectively binds to an antibody that binds to a polypeptide or a fragment, derivative, or variant thereof as described herein or an antigen binding fragment of said antibody. In a fifth aspect of the present invention there is provided a composition comprising an antibody of the invention together with a pharmaceutical carrier. The invention also provides vectors comprising nucleic acids of the invention and cells comprising such vectors. In the sixth aspect of the invention there is provided a construct comprising a nucleic acid molecule which encodes a polypeptide of the invention, for example an isolated nucleic acid, or a fragment, derivative, or variant thereof operably linked to a promoter which is functional to allow transcription of the nucleic acid sequence and the expression of an R. equi polypeptide of the invention. The present invention also provides a process for producing a polypeptide or a fragment, derivative, or variant thereof as described herein according to any embodiment, said method comprising culturing a cell comprising a nucleic acid encoding a polypeptide or a fragment, derivative, or variant thereof of the present invention operably linked to a promoter under conditions suitable for expression of the polypeptide or a fragment, derivative, or variant thereof. A suitable nucleic acid may comprise a polynucleotide sequence or fragment thereof of a gene selected from Table 1, or more preferably Table 2. In one example, the method additionally comprises recovering the polypeptide from the cell culture, e.g., from the medium in which the cell is cultured. In embodiments the present invention provides a method of producing a polypeptide or a fragment, derivative, or variant thereof of the invention, said method comprising the steps of: (i) culturing a host cell comprising a nucleic acid encoding a polypeptide of the present invention or a vector encoding the same, and (ii) recovering the polypeptide of the present invention from the host cell or culture medium. In embodiments, the construct comprises an isolated nucleic acid which encodes a polypeptide of the invention or a fragment, derivative, or variant thereof operably linked to a promoter which is functional in a host cell to allow transcription of the nucleic acid sequence and the expression of a R. equi polypeptide of the invention. In alternative embodiments, the construct comprises an isolated nucleic acid which encodes a polypeptide of the invention or a fragment, derivative, or variant thereof operably linked to a promoter which is functional in a heterologous host system, for example an attenuated vaccinal strain, including, but not limited to, a microbial system, a virus, a parasite, an attenuated pathogen or normal or immuno-stimulating microbiota. Suitably, the heterologous host system construct may be delivered as a live vaccine alone or in combination with other relevant protective antigens in a polyvalent vaccine. In embodiments, the construct can comprise a nucleic acid comprising a polynucleotide sequence of a gene selected from at least one gene identified by Table 1, more preferably a gene selected from Table 2, operably linked to a promoter. In embodiments, the construct can comprise a nucleic acid sequence comprising a polynucleotide sequence of SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8 or 9, more preferably a polynucleotide sequence which can encode SEQ ID NO 10 or 11. In a seventh aspect of the invention there is provided a construct of the sixth aspect of the present invention in combination with a pharmaceutical carrier. In an eighth aspect of the present invention there is provided a composition capable of treating or preventing a disease caused by R. equi , comprising one or more surface-associated (a polypeptide naturally associated to the surface structures or on the outer surface of R. equi .) or secreted polypeptides of R. equi wherein said polypeptides form pili of R. equi . In embodiments the composition can be a vaccine capable of preventing a disease caused by R. equi , which results in the production of antibodies against a polypeptide of R. equi which can form the pili of R. equi and wherein the polypeptide is reactive against antibodies or immune cells recovered from animals repeatedly infected with R. equi. In embodiments, the polypeptide of R. equi which can form the pili of R. equi , wherein the polypeptide is reactive against antibodies and/or immune cells recovered from animals repeatedly infected with R. equi comprises the amino acid sequence encoded by a polynucleotide sequence of a gene selected from Table 1, or more preferably Table 2 or is an immunogenic fragment or variant or derivative of such a polypeptide. In embodiments of the invention, the subject for which the vaccine can be administered is a foal and immunisation results in an immune response which inhibits or prevents R. equi infection and results in the production of antibodies employed as an immunogen. In embodiments the subject to which the vaccine is administered can be a horse and immunisation results in an immune response which inhibits or prevents R. equi ., or in the production of antibodies to the polypeptide employed as an immunogen. While the invention is particularly directed to polypeptide suitable as antigen in a vaccine for use in horses or foals, it will be clearly understood that it is applicable to any other animal which is susceptible to infection with R. equi , including humans, pigs, cattle, sheep, goats, lama, cats or animals which have a similar biology and would be understood to share a high degree of genomic similarity to horses. It will also be appreciated that the diagnostic, therapeutic and prophylactic aspects of the invention are also applicable to subjects which have been exposed to an animal infected with R. equi , or an environmental source contaminated with R. equi such as faeces, soil, or the like. According to a ninth aspect of the present invention there is provided a method of treating or preventing a disease or condition caused by R. equi comprising the step of administering a polypeptide of the invention or a fragment, derivative, or variant, an antibody, a nucleic acid, composition and/or a vaccine of the invention to subjects suffering from, or suspected to be suffering from, or at risk of a condition mediated by R. equi. There is provided the use of a polypeptide of the invention or a biologically active and/or immunogenic fragment, derivative, or variant, an antibody, a nucleic acid, composition and/or a vaccine of the invention in the preparation of a medicament for the treatment of a condition mediated by R. equi . In embodiments the treatment may be prophylactic treatment to prevent or inhibit infection. There is provided a polypeptide of the invention or a fragment, derivative, or variant, an antibody, a nucleic acid, composition and/or a vaccine of the invention for use in the treatment of a condition mediated by R. equi . In embodiments the treatment may be prophylactic treatment to prevent or inhibit infection. According to a tenth aspect of the present invention there is provided a method of detecting R. equi comprising the step of detecting a polypeptide of the invention or a fragment, derivative, or variant, or an antibody of the invention in a sample, or a polynucleotide of the invention which can encode a polypeptide of the invention or fragment thereof. In embodiments, a sample may be a soil sample. In embodiments, there is provided a method of diagnosing a disease or condition caused by R. equi comprising the step of detecting a polypeptide of the invention or a fragment, derivative, or variant, or an antibody of the invention in a biological sample from a subject suffering from, suspected to be suffering from, or at risk of such a condition, or a polynucleotide of the invention which can encode a polypeptide of the invention or fragment thereof. Detection of a polypeptide or an antibody of the invention may be achieved by a variety of methods, including but not limited immunoassay methods such as radioimmuno assay, enzyme linked immunoabsorbent assays (ELISA), chemiluminescence assays, immunohistochemistry, immunoblotting, for example Western blotting, immunofluorescence and mass spectrometry. An example of use of an antibody to detect a polypeptide of a R. equi pili (RplB) is provided in the Examples herein. Suitably, detection of antibodies with binding specificity to a polypeptide encoded by any one of SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8, or 9 may be used as a test for R. equi in horses. In embodiments, PCR testing for nucleic acids encoding a polypeptide of the pili, for example as encoded by any one of SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8, or 9 may be used as a test for R. equi , particularly where a quantitative detection is preferred. Based on the nucleic acid sequence data provided herein, suitable primers or probes for use in the detection of nucleic acid sequences which can encode polypeptides of the pili of R. equi could be provided as would be understood in the art. As will be understood, suitably, in embodiments, said probes or primers can hybridise to the nucleic acid sequences encoding peptides associated with pilus formation, preferably any one of SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8, or 9, under stringent conditions. Hybridisation refers to the binding, duplexing, or hybridizing of a molecule only to a particular nucleotide sequence under stringent conditions when that sequence is present in a complex mixture (e.g., total cellular) DNA or RNA. Stringent hybridisation occurs when a nucleic acid binds the target nucleic acid with minimal background. Typically, to achieve stringent hybridisation, temperatures of around 1° C. to about 20° C., more preferably 5° C. to about 20° C. below the Tm (melting temperature at which half the molecules dissociate from their partner) are used. However, it is further defined by ionic strength and pH of the solution. An example of highly stringent wash conditions is 0.15 M NaCl at 72° C. for about 15 minutes. An example of a stringent wash condition is a 0.2×SSC wash at 65° C. for 15 minutes (see, Sambrook and Russell, infra, for a description of SSC buffer). Often, a high stringency wash is preceded by a low stringency wash to remove background probe signal. An example of a medium stringency wash for a duplex of, for example, more than 100 nucleotides, is 1×SSC at 45° C. for 15 minutes. An example of a low stringency wash for a duplex of for example more than 100 nucleotides, is 4-6×SSC at 40° C. for 15 minutes. For short probes (for example about 10 to 50 nucleotides), stringent conditions typically involve salt concentrations of less than about 1.5 M, more preferably about 0.01 to 1.0 M, Na ion concentration (or other salts) at pH 7.0 to 8.3, and the temperature is typically at least about 30° C. and at least about 60° C. for long probes (for example, >50 nucleotides). Detection of a polynucleotide of the invention may be by any suitable means, for example using PCR, a microarray or the like as would be known in the art. In an eleventh aspect of the present invention there is provide a kit to detect R. equi wherein the kit comprises a polypeptide or antibody of the invention or a nucleic acid probe. In embodiments a kit can comprise a polypeptide or antibody of the invention. In embodiments, the kit is for use in the method of diagnosing a disease or condition caused by R. equi wherein the kit comprises a polypeptide or antibody of the invention or a nucleic acid probe. In embodiments a kit can comprise a polypeptide or antibody of the invention. In embodiments, the kit can include a solid support, for example a test strip, plastic bead or the like to which polypeptide or antibody of the invention can be coated. The kit may include a detection antibody capable of binding to a polypeptide or antibody of the invention which comprises a detectable label or binding site for a detectable label. Suitably a labelling molecule can include an enzyme, fluorescent label or radiolabel. Binding sites for detectable labels include avidin, biotin, streptavidin and the like. Additionally, the kit can include instructions for using the kit to practise the present invention. The instructions should be in writing in a tangible form or stored in an electronically retrievable form. A further aspect of the present invention provides a method of screening immunogenic R. equi polypeptides of the invention or a fragment, derivative, or variant thereof to determine if a test agent can bind to said polypeptide comprising the steps: providing a candidate immunogenic R. equi polypeptide of the invention or a fragment, derivative, or variant thereof, providing a test agent to the candidate immunogenic R. equi polypeptide and determining whether said test agent can bind to said candidate immunogenic R. equi polypeptide. A test agent which can bind to a R. equi polypeptide of the invention may inhibit the activity of said polypeptide, minimise its secretion or inhibit its ability to form functional pili. In embodiments, such a test agent may be a useful therapeutic. The present invention also provides the use of a polypeptide or a fragment, derivative, or variant thereof or an antibody as described herein in medicine. In a twelfth aspect, the present invention provides the use of a polypeptide of the invention or a fragment, derivative, or variant thereof, an antibody, composition and/or vaccine of the invention in the treatment or prevention of a disease or condition caused by R. equi. In one embodiment of the invention, a method of treatment comprises the steps: (i) identifying a subject suffering from a disorder associated with or R. equi or at risk of developing R. equi; (ii) administering a polypeptide, or composition as described herein to said subject. In another embodiment, the invention provides a method of treatment comprising administering or recommending a polypeptide, or a fragment, derivative, or variant thereof or an antibody or composition as described herein to a subject previously identified as having R. equi infection or suffering from a condition associated with R. equi infection. The invention may also provide a method of treatment of a subject in need thereof, said method comprising: (i) identifying a subject suffering from a disorder associated with or R. equi or at risk of developing R. equi; (ii) obtaining a polypeptide or a fragment, derivative, or variant thereof as described herein according to any embodiment, (iii) formulating the polypeptide or antibody with a suitable carrier and/or excipient to form a composition wherein said composition is in an amount sufficient to reduce or prevent or inhibit R. equi infection or suffering from a condition associated with R. equi infection and (iv) administering said composition to said subject. In a further embodiment there is provided a method of treatment of a subject in need thereof, said method comprising: (i) identifying a subject suffering from a disorder associated with or R. equi . or at risk of developing R. equi.; (ii) obtaining a polypeptide or a fragment, derivative, or variant thereof or an antibody as described herein according to any embodiment, (iii) formulating the polypeptide or antibody with a suitable carrier and/or excipient to form a composition wherein said composition is in an amount sufficient to reduce or prevent or inhibit R. equi infection or suffering from a condition associated with R. equi infection and (iv) recommending administration of a composition at (iii). In embodiments a polypeptide on the invention can be provided to a subject to generate a protective immune response in the subject. In particular embodiments the polypeptide may act as a vaccine. Sequences identified in the patent application include: SEQ ID NO 1 rpIA REQ_18350> - 3104103:3104891 GTGATCGTCGCAGCGGGCGTCGGCGCCGCACTCCTGGGTATCCTCG CCGGGGCGTTCGCGAACAGTGCGATCGACCGCGTGCGCCTGGAGA CCGCGTGCGCCGAGCCGAAGTCGACCCCCACCGGCTCAACCCCGC CGCCCCCCTCCCCTGCGTCCGCGGTAGCCACCCGGATCGCGATGAT CGACACCATCACGCGACGACACGACATCAGTGCCCGCCGCGTGCTC GTCGAACTCGCAACGGCCCTCCTGTTCGTCGGGATCACTCTCCGTCT CGCCGCTCTCGGTCTTCTCCCGGCAACACCGGCCTATCTCTTGCAAA CGGCTGCCGAACTTCCTCGTCGTACCGTCGTACCCGATCGTATTCGC CTGCCTTTCAGTGGGTTCCGTCGTGCCGTTCTGTTCGGGGTCTACTT CGTACTAGCCCTGATCTATCCGGCCGGCATGGGGTTCGGCGACGTC AAACTTGCCGGCGTCATCGGCGCCGTCCTCGCCTACCTGTCGTACG GCACATTGCTCGTCGGGGCGTTTCTCGCGTTCCTGGTGGCCGCACT CGTCGGCCTGATCATCCTGGTCACCCGTCGCGGTCGGATCGGGACC ACGATTCCCTTCGGGCCGTACATGATTGCGGCGGCCATCGTTGCGAT CCTGGCGGCCGATCCGCTGGCGCGCGCGTATCTGGACTGGGCCGC CGCGGCCTGA SEQ ID NO 2 rpIB REQ_18360> - 1939395:1939601 ATGAACCTCTTCTTCGCGAACCTGTACCTCATGGGCTTAGACGTCAA GGACCGTCTGACCCGTGACGACCGCGGCGCCACTGCGGTCGAGTAC GGACTGATGGTCGCCGGCATCGCGATGGTGATCATTGTTGCGGTTTT CGCCTTCGGCGATAAGATTACCGACCTCTTCGATGGCTTCAACTTCG ACGATCCCGGCGGCGAGTAG SEQ ID NO 3 rpIC REQ_18370> - 1939683:1940084 ATGAAGCGCCTCACTTCCGATTCAGGGGTCGCCGCAGTCGAATTCGC TCTCGTCGTTCCGATCCTGATCACACTGGTCCTCGGCATCGTGGAGT TCGGTCGGGGTTACAACGTCCAGAACGCGGTCAGCGCTGCTGCCCG CGAGGGTGCACGGACGATGGCGATCAAGAAGGATCCGGCGGCGGC GCGTGCTGCCGTGAAGGGCGCGGGTGTGTTCAGTCCGGCGATCACC GATGCGGAGATCTGCATCAGCACTTCGGGAACGCAGGGCTGTTCGG CAACGTCGTGTCCGAGCGGAAGTACCGTGACGCTCACGGTCAGCTA TCCACTCGAGTACATGACGGGACTCTTTCCCGGTAAGCCGACGCTCA CCGGCACGGGGGTCATGCGATGCGGTGGGTGA SEQ ID NO 4 rpID REQ_18380> - 1940093:1941037 ATGTCGAATGACGAGCGCGGGGTCGTCGCCGTGCTCGTTGCGATCC TCATGGTCGTGCTCCTGGGATGTGCTGCGATCTCGGTCGACATCGGT GCGAACTATGTCGTCAAACGTCAGTTGCAGAACGGGGCCGATGCGG CTGCGCTCGCCGTAGCTCAGGAATCCAGTTGCAAGGCAGGATCTTCC GCCTCATCCGTGTCGAGCCTTGTCCAGGCGAACGTCAACAGCTCGTC GGCTGCAAGTGCGGCGGTGATCGACGGTGTGAAGCGGAAGGTGAC GGTCACTGCGTCGGCGGTGGGTGACGACGGCCTCGCCGGCCGGAG GAACGTGTTCGCTCCGGTCCTCGGAGTCGACCGCAGCGAGATCTCG GCGTCTGCGACTGCAAGCTGCGTGTTTCCCCTCGGGGGGACCGCGG AACTCCCGCTCACGTTCCACAAGTGCCATTTCGACGAATCCCGCAGT CTGGACGTGAAGATCCTCGTCGCCTACAACGTGACGGCGCCGCGCT GCAATGGAACCTCGGGAAATGCGGCACCGGGCAATTTCGGCTGGCT GCAGGGGGCGAACGGTCGATGCCCGGCGAAGATCGACGCCGCCGT CTACGCAACACCGGGCGACACCGGTAACAACATTCCGGGGCCGTGC AAGGACACCATCAAGCAGTTTCAGAATGCCGTCGTGCGGGTCCCGAT CTACGACGTCGCAGGTGGAACCGGAAGCGGTGGATGGTTTCACGTC GTCGGTTTGGCTGCCTTCAAGATTCAGGGCTACCGGCTGAGCGGCA ACCCGGAGTTCAACTGGAACAACGATGTTCACGGGGCGCTGAGTTG CACCGGCAGCTGTCGCGGCATCATCGGCACCTTCGTGAAGATTGTCA GCCTCGATTCGGATCTGACGCCGGGAGGGATCGATTTCGGCGTGAG TACGATCAGCTTGCTCGATTAG SEQ ID NO 5 rpIE REQ_18390> - 1941047:1941784 TTGAGAACCCGAATCATTGCTGCGATCTGTGCGATCGTTCTCGCGGT CGCGGGAACCCTCGCCCTGATCTCGTATGTACGCGGGGCCGATGCC CGCGCCCTGGCGGGTACACGCACCGTCGATGTGCTCGTCGCCGATC AGACGATTCCGAAGAACACTCCCGCTGATTCGCTCGTGGGAATGGTT GTGGTCAAGAAACTTCCGGAAATGGCGGTGCTACCCGATCGGGTGA CCAGTCTCGACCAACTGTCCGGCAAGGTCGCGCTGACCGACCTCCT GCCTGGCGAACAACTGGTCTCGGCGCGATTCGTCGACCCGGCGACC GCCCGAAGTCAGGACCAGGGAGGAATCCCCGAGGGGATGCAGGAG GTGACGGTTCTTCTCGAGCCGCAACGCGCACTGGGAGGCCACATCG CGTCGGGCGATACCGTCGGCGTCTTCATGTCCTTCTCGCCGCCCGT CAAGAACTACGAAACACATCTGAGATTGCAGAAAGTGCGAGTCACGC GGGTCCAGGGAACGTTCTCCAACGCCGACGAAGGGGATTCGGCCAC GGTCGACTCGTCGCCGAGCCCTGCTCCCACCGAGGCCTTTCTCGTC TCGCTGGCGGTCGACGTGCCGATGGCGGAGCGCGTCGTTTTCGCCG CGGAGCACGGGACCATCTGGCTTTCCAATGAGCCGCCGAGTTCGAA CGAGGCCGGGGCATCCGTGGTCTCCCCGGAAGGAGTGTTCCGATGA SEQ ID NO 6 rpIF REQ_18400> - 1941781:1942980 ATGAGCCGCATCGTCCTGCTGACCGATCGCGACGATTTCGCCCGCC GCGTGTACCACGCCGCGGACGGCAACCTTCTGGTGTTGCCGGCGCA GCCGGTTCCCCGGGGGCCGGCGCAGTTGGTCGGGCTCGGCGTGAC CGTGCAACCAGAAGTTCTCGTTCTCGGTCCGGACGTGCCGGAAGTG GAGGGCCTCTCCCTCGCCGGCCGGATCGATCATTCGACGCCCGGCA CCACGGTGGTTCTGGCCAGTGATGCGGGCACCGACGTGTGGTTGCG GGCGATGCGCGCCGGCGTGCGGGACGTGATGTCGCCGGAGGCGGA GATCGCGGACGTTCGTGCGGTACTCGATCGAGCGGGCCAGGCCGCA CTGGCGCGACGTCAGGGGGCGAGTGCACCGGCGGAGCAGCATGCG GTTCAAGGGAAGGTCATCGTGGTCGCGTCGCCGAAAGGCGGAACCG GAAAGACCACCGTTGCGACGAATCTTGCAGTAGGACTCGCGGCGGC AGCGCCTCACTCGACGGTGTTGGTGGACCTCGACGTGCAGTTCGGG GACGTTGCCAGTGCTCTCCAGTTGGTTCCGGAACATTGCCTGACCGA CGCCGTCGCGGGCCCGGCCAGCCAGGACATGATCGTCCTCAAGACC GTCCTGACACCCCATTCCACAGGACTGCATGCGCTGTGTGGGTCGG ACTCGCCCGCGGCGGGCGACAGCATCACCGGCGAGCAGGTGAGCA CTCTGCTGACGCAGTTGGCGGCCGAATTCCGGTACGTGGTCGTCGA CACCGCGCCCGGTTTGCTCGAACACACCCTGGCGGCGCTCGACCTT GCTACCGACGTCGTGTTGGTGTCGGGTATGGACGTGCCCAGCGTCC GCGGGATGCACAAGGAACTGCAATTGCTGACGGAGCTGAATCTGGG TCCGGTCGTGCGGCATGTCGTGCTCAACTTTGCGGATCGACGCGAG GGGCTGACGGTCCAGGACATCCAGAACACCATCGGGGTCCCCGCCG ATATCGTGATCAAGCGCTCGAAAGCCGTTGCCCTCTCGACGAACCGG GGGGTTCCACTGCTTCAGAACCCGGGTCGGGATCGCACTGCGAAAG AGTTGTGGCGACTCGTCGGCCGTATCGATCCGGCTCCCGATACCGC CAAGGGTGGACGCGCGCGGCATCGGGCAGCCGAGGCGGTGGGTGC GAAATGA SEQ ID NO 7 rpIG REQ_18410> - 1942977:1944374 ATGAGACTGTCCCAACGGCTCGAGGCCGTGCGCGGAGCCGCACCC GTCGAAGCCGCCGCACCGATCCCGCCGGGGAAGCAGGGGAAGGCG AAAACGTCCCTCCCTCCGGCCGACGCTCTCGCCGAACTGAAGGACC GTGCGAGTGCGGCCCTGTACACCCGGATCGGCACCCGCTTCAACGA CTCCTCGTTGAGCGAGGAGCAACTGCATCTCCTGGTCCGTGAGGAA CTGGCCGAAATCGTGGAGCAGGAGACGACGCCACTCACCTTCGACG AACGGCAGCGCCTGCTCCGTGAGGTTGCCGACGAGGTACTGGGGCA CGGACCGCTCCAGCGGCTACTGGAGGACCCGTCGGTCACCGAGATC ATGGTCAACAGCCACGACATGGTCTACGTCGAGCGGGACGGCACCC TCGTCCGCAGCTCCGCGCGATTCGCGGACGAGGCGCACCTGCGTCG CGTGATCGAACGCATCGTTTCCGCCGTCGGTCGACGGATCGACGAA TCGTCCCCGCTCGTGGATGCACGCTTGGCGGATGGCTCCCGTGTCA ACGCGGTGATCCCACCGCTCGCATTCAACGGCTCCTCGCTCACCATT CGAAAGTTCTCGAAAGATCCGTTCCAGGTCGACGATCTCATCGCCTT CGGCACTCTCTCGCACGAGATGGCCGAACTGCTCGACGCGTGTGTG CAGGCGCGACTGAACGTCATCGTCTCGGGCGGCACGGGCACGGGG AAGACGACGCTGCTCAACGTGCTCTCGTCGTTCATTCCGGAAGGGGA GCGGATCGTCACCATCGAGGACGCCGTGGAACTGCAACTTCAGCAG GACCACGTCGTACGGTTGGAGAGCCGACCGCCGAACATCGAGGGCA AGGGTGCCGTCACCATCCGCGACCTGGTGCGGAACTCGCTGCGTAT GCGTCCCGACCGCATCGTGGTGGGGGAGTGTCGCGGAGGCGAGAG TCTCGACATGCTGCAAGCGATGAACACCGGTCACGACGGGTCGCTG TCGACGGTGCATGCGAATTCGCCCCGTGACGCCATCGCGCGCTTGG AGACGCTCGTGTTGATGGCCGGCATGGACCTGCCGTTGCGGGCGAT CCGGGAGCAGATTGCTTCGGCGGTCGACGTGATCGTGCAGCTCACT CGACTACGTGACGGCACTCGGCGAGTGACCCACGTGACCGAGGTCC AGGGCATGGAGGGTGAGATCGTCACCCTGCAGGATGCCTTCCTGTT CGACTACAGCGCCGGCGTCGACGCGCGCGGGCGATTCCTCGGCAG ACCGCAGCCGACCGGAGTGCGGCCGCGGTTCACCGACAGATTCCGA GATCTCGGTATTGCTTTGTCGCCGAGTGTTTTCGGGGTGGGAGAACC CTCCCGGGGGCGGGTATGA SEQ ID NO 8 rpIH REQ_18420> - 1944371:1946239 ATGAGCCGGTGCGTGGTGGCCGTCGTGCTCGCCCTCGGTGCGGGT GTTCTGGGAATTCCCGCCGTAGCCGCGGCGGCCGAGGAGGCTGTCC AGGTCTCGGCGGTCGACACGACCCGGTTTCCCGACATCGAGGTGTC CATCCTCGCGCCGCCCGGTATCGAAGGGCAGGCGATCGATCCGGGA ACGTTCGCGCTCACCGAGGGCGGCGTGCCGCGAGAGATCGAGGTC AGGCAGCAGCCGGGTTCCGAGCAGGACATCGTGCTCGCAATCGACG TGTCCGGGGGCATGTCGGGTCCGGCGCTGGACGACGTGAAGCGCG CCGCATCGGATTTCGTGCGGCAGGCGCCGGCCGGCGCCCACATCG GAATCGTCGCGATCTCGTCGACGCCACAGGTGCTCTCGGAACTGAC GACGGACTCCGAGGACCTGCTCCGCAGGATCGACGGACTGAAGGCG GGCGGCAACAGCGCGATCGCAGATTCGGTGGTGACCGCCGCCGAG ATGCTCGAGCGCGGCGAAGCGGCCAACAACATCCTGCTTCTGTTGA CGGACGGCGCCGACACGTCGAGTGCACACTCGATGTCGGAACTCCC GTCCGTCCTGAGTCGGTCGCGCGCGTCGCTGTACGCCGTGCAGATG TCGACACCCGAGACGAACTCTGCTCTCCTGCAGCAGGTTGCGCGGG AGTCGCGCGGTCAGTACGCGTCTGCGGGTGATACGGCGGCGCTGG GTGCGATCTACCAGTCGGCCGCTCGCGCGCTCGGAAACCTGTACGT CGTCCGATACCGATCGGAAGCGAATGGCGATACCCAGGTGGTGGCG AGCGTGCGCAGCGGCGCAGCCGGCCGAGTGAGCGATCCGTTCCCG GTGACATTGCCCGGTGTGGTGCCGACGCCGAGCGTCGTCGCCGGG ACCGTCGACGGTTTCTTCACGTCTTCGACGGGGCTGGTGATCGGGC TCCTAGCGTGCTACTCGGCGCTTGCGGGAGGCGTGCTGGCGGTCGC CGGTAGAGCGCCCGCGAGGATTTCGGCAGCACGTCGTGGGCGGCA GGACGGACGGGACTCGATGCTGTCCCGATTCGCGGAACGGCTGGTG CAGTGGATCGATCAGAACCTGAGGAGACGCGGACGCATCGCTGCCC GCACCCAGGCGCTACAGGAGGCGGGGCTGAAGCTTCGTCCAGGTGA CTTCATCGCCCTGGTCGGTGCTGCGGCGATCACCGCTGCGGCGATC GGTCTCCTGGCTTCGGGCATCGTGGCGGCGCTCTTGCTCGCGGCGA TCACAGTGGGATTGTCGAGAATCTATCTCCGTGTGATGGCCGGTAGG CGTCGGGCCGCGTTCGCTGATCAGCTCGACGATTCCCTGCAGCTGC TGGCCAGCAATCTCCGAGCCGGGCACAGCATGCTCCGAGCGCTCGA TTCCCTTTCCCGAGAGGCGGAGGTGCCGACTTCGGAGGAGTTCGCT CGGATCGTCAACGAGACTCGGGTGGGACGTGATCTCAACGAGTCTC TCGACGACGTGGCCCGGCGGATGCGAAGTGACGATTTCAACTGGAT AGCTCAGGCAATCGCCATCAACCGTGAGGTCGGAGGCGACCTCGCG GAAGTCCTCGACCAGGTGGGCAACACCATTCGAGAGCGAAATCAGAT TCGACGGCAGGTGAAAGCCCTTGCTGCCGAGGGGAAACTGTCCGCC TACGTGCTGATGGCGCTGCCCTTCGGTCTCACCGCATTTCTGCTCGT CTCGAATCCGGACTACCTGTCGAAGTTGACGGGTAGCGCCATCGGC TACGTGATGATCGCGGTGGGGCTCGTCATGCTGACCGTCGGTGGGC TGTGGATGAACAAGGTTGTCTCGGTCAAGTTCTAG SEQ ID NO 9 rpII REQ_18430> - 1946262:1947152 GTGATTCCACCGCTGGTGCTCATGGCGGCGCTGTCCGTCGGCGGGG CGTTGGGTGTTCTGGTGTGGTTGACGGTCGGCGCCCGAGATCCGGA ACGCGGACCCGCCCTTCGGAACCTGCAGTCGCAGCTGGCGTTGCCG ATTCCGGAGTCGGGAGGCGCGCCACCGCTTTCGCTCGGCCGATTCG TGAAGCTGCTGTCGCCGCCCGGGACGATGGCCCGCTTGGAACGACT GCACATCCTTGCCGGTCGTCCAGCGGCGTGGGTTCCGGAACGGGCC GCGATGGCGAAGATCGTTCTCGCCGCGGCCGCCGCCCTGCTCGGC CTTCTCGCGGTGGGTGCGTCGCCTGGCGTCGGCCGGGTGCTGTTCG CTGCGGCCGCCGTCGCGCTGGCGTATTTCGTCCCGGAACTTCTCCT GCAGAGCAGGGGGCAGGAGCGCCAAGCCGCGATCGAACTGGCGCT TGCCGACACCCTCGACCAGATGACGATCGCAGTCGAGGCGGGCCTG GGGTTCGAAGCCGCCATGCAGCGGGCCGCGAAGAACGGAAAGGGG CCGCTGGCCGAGGAATTCATCCGGACATTGCAGGACATACAGATGG GGCAGTCGAGGCGAATCGCGTACCTGGATCTTGCCGCCAGAACGAA AGCACCCAACTTGCGGAGGTTCCTTCGGGCCGTCATCCAAGCCGAC GAGTACGGCGTGGCCATCGCCGAGGTCCTGCGGACCCAGGCCTCG GAGATGCGTCTGAAACGCCGTCAGAGTGCTGAGGAGAAGGCGATGA AGGTTCCGGTGAAGGTGCTGTTTCCGTTGATGACCTGCATCCTGCCG ACCATCTTCATCGTGATCCTGGGTCCGGCGGTGATCAACATGATGGA GGTCTTGGGCGGTATGTAA SEQ ID NO 12 RpIA: VIVAAGVGAALLGILAGAFANSAIDRVRLETACAEPKSTPTGSTPPPPSP ASAVATRIAMIDTITRRHDISARRVLVELATALLFVGITLRLAALGLLPA TPAYLWFAAVGIALAVIDIDCKRLPNFLVVPSYPIVFACLSVGSVVTGDW SALLRAAIGAAVLFGVYFVLALIYPAGMGFGDVKLAGVIGAVLAYLSYGT LLVGAFLAFLVAALVGLIILVTRRGRIGTTIPFGPYMIAAAIVAILAADP LARAYLDWAAAA SEQ ID NO 13 RpIB: MNLFFANLYLMGLDVKDRLTRDDRGATAVEYGLMVAGIAMVIIVAVFAFG DKITDLFDGFNFDDPGGE SEQ ID NO 14 RpIC: MKRLTSDSGVAAVEFALVVPILITLVLGIVEFGRGYNVQNAVSAAAREGA RTMAIKKDPAAARAAVKGAGVFSPAITDAEICISTSGTQGCSATSCPSGS TVTLTVSYPLEYMTGLFPGKPTLTGTGVMRCGG SEQ ID NO 15 RpID: MSNDERGVVAVLVAILMVVLLGCAAISVDIGANYVVKRQLQNGADAAALA VAQESSCKAGSSASSVSSLVQANVNSSSAASAAVIDGVKRKVTVTASAV GDDGLAGRRNVFAPVLGVDRSEISASATASCVFPLGGTAELPLTFHKCH FDESRSLDVKILVAYNVTAPRCNGTSGNAAPGNFGWLQGANGRCPAKI DAAVYATPGDTGNNIPGPCKDTIKQFQNAVVRVPIYDVAGGTGSGGWF HVVGLAAFKIQGYRLSGNPEFNWNNDVHGALSCTGSCRGIIGTFVKIVSL DSDLTPGGIDFGVSTISLLD SEQ ID NO 16 RpIE: LRTRIIAAICAIVLAVAGTLALISYVRGADARALAGTRTVDVLVADQTIP KNTPADSLVGMVVVKKLPEMAVLPDRVTSLDQLSGKVALTDLLPGEQLVS ARFVDPATARSQDQGGIPEGMQEVTVLLEPQRALGGHIASGDTVGVFMSF SPPVKNYETHLRLQKVRVTRVQGTFSNADEGDSATVDSSPSPAPTEAFL VSLAVDVPMAERVVFAAEHGTIWLSNEPPSSNEAGASVVSP EGVFR SEQ ID NO 17 RpIF: MSRIVLLTDRDDFARRVYHAADGNLLVLPAQPVPRGPAQLVGLGVTVQP EVLVLGPDVPEVEGLSLAGRIDHSTPGTTVVLASDAGTDVWLRAMRAGV RDVMSPEAEIADVRAVLDRAGQAALARRQGASAPAEQHAVQGKVIVVA SPKGGTGKTTVATNLAVGLAAAAPHSTVLVDLDVQFGDVASALQLVPEH CLTDAVAGPASQDMIVLKTVLTPHSTGLHALCGSDSPAAGDSITGEQVST LLTQLAAEFRYVVVDTAPGLLEHTLAALDLATDVVLVSGMDVPSVRGMH KELQLLTELNLGPVVRHVVLNFADRREGLTVQDIQNTIGVPADIVIKRSK AVALSTNRGVPLLQNPGRDRTAKELWRLVGRIDPAPDTAKGGRARHRAA EAVGAK SEQ ID NO 18 RpIG: MRLSQRLEAVRGAAPVEAAAPIPPGKQGKAKTSLPPADALAELKDRASA ALYTRIGTRFNDSSLSEEQLHLLVREELAEIVEQETTPLTFDERQRLLRE VADEVLGHGPLQRLLEDPSVTEIMVNSHDMVYVERDGTLVRSSARFADEA HLRRVIERIVSAVGRRIDESSPLVDARLADGSRVNAVIPPLAFNGSSLTI RKFSKDPFQVDDLIAFGTLSHEMAELLDACVQARLNVIVSGGTGTGKTTL LNVLSSFIPEGERIVTIEDAVELQLQQDHVVRLESRPPNIEGKGAVTIRD LVRNSLRMRPDRIVVGECRGGESLDMLQAMNTGHDGSLSTVHANSPRDAI ARLETLVLMAGMDLPLRAIREQIASAVDVIVQLTRLRDGTRRVTHVTEVQ GMEGEIVTLQDAFLFDYSAGVDARGRFLGRPQPTGVRPRFTDRFRDLGI ALSPSVFGVGEPSRGRV SEQ ID NO 19 RpIH: MSRCVVAVVLALGAGVLGIPAVAAAAEEAVQVSAVDTTRFPDIEVSILAP PGIEGQAIDPGTFALTEGGVPREIEVRQQPGSEQDIVLAIDVSGGMSGPA LDDVKRAASDFVRQAPAGAHIGIVAISSTPQVLSELTTDSEDLLRRIDGL KAGGNSAIADSVVTAAEMLERGEAANNILLLLTDGADTSSAHSMSELPSV LSRSRASLYAVQMSTPETNSALLQQVARESRGQYASAGDTAALGAIYQSA ARALGNLYVVRYRSEANGDTQVVASVRSGAAGRVSDPFPVTLPGVVPT PSVVAGTVDGFFTSSTGLVIGLLACYSALAGGVLAVAGRAPARISAARRG RQDGRDSMLSRFAERLVQWIDQNLRRRGRIAARTQALQEAGLKLRPGD FIALVGAAAITAAAIGLLASGIVAALLLAAITVGLSRIYLRVMAGRRRAA FADQLDDSLQLLASNLRAGHSMLRALDSLSREAEVPTSEEFARIVNETRV GRDLNESLDDVARRMRSDDFNWIAQAIAINREVGGDLAEVLDQVGNTIRE RNQIRRQVKALAAEGKLSAYVLMALPFGLTAFLLVSNPDYLSKLTGSAIG YVMIAVGLVMLTVGGLWMNKVVSVKF SEQ ID NO 20 RpII: VIPPLVLMAALSVGGALGVLVWLTVGARDPERGPALRNLQSQLALPIPES GGAPPLSLGRFVKLLSPPGTMARLERLHILAGRPAAWVPERAAMAKIVLA AAAALLGLLAVGASPGVGRVLFAAAAVALAYFVPELLLQSRGQERQAAIE LALADTLDQMTIAVEAGLGFEAAMQRAAKNGKGPLAEEFIRTLQDIQMG QSRRIAYLDLAARTKAPNLRRFLRAVIQADEYGVAIAEVLRTQASEMRLK RRQSAEEKAMKVPVKVLFPLMTCILPTIFIVILGPAVINMMEVLGGM Preferred features and embodiments of each aspect of the invention are as for each of the other aspects mutatis mutandis unless context demands otherwise. Each document, reference, patent application or patent cited in this text is expressly incorporated herein in their entirety by reference, which means it should be read and considered by the reader as part of this text. That the document, reference, patent application or patent cited in the text is not repeated in this text is merely for reasons of conciseness. Reference to cited material or information contained in the text should not be understood as a concession that the material or information was part of the common general knowledge or was known in any country. Throughout the specification, unless the context demands otherwise, the terms ‘comprise’ or ‘include’, or variations such as ‘comprises’ or ‘comprising’, ‘includes’ or ‘including’ will be understood to imply the includes of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. By “consisting essentially of” it is meant that a nucleic acid does not include additional, substituted or deleted nucleotide(s) to a polynucleotide sequence of the invention described herein or a polypeptide does not include additional, substituted, or deleted amino acids which significantly alter the character of a sequence of the invention such that it is not immunogenic and biologically active. As used herein, the singular forms “a”, “an”, and “the” include the corresponding plural reference unless the context clearly dictates otherwise. Where a range of values is expressed, it will be understood that this range encompasses the upper and lower limits of the range and all values in between these limits. The terms “polypeptide”, “protein” and “peptide” are herein used interchangeably. The term “isolated” refers to materials, such as nucleic acid molecules, which are substantially free or otherwise removed from components that normally accompany or interact with the materials in a naturally occurring environment. An isolated nucleic acid typically contains less than about 50%, preferably less than about 75%, and most preferably less than about 90% of the components with which it was originally associated. Polypeptides, antibodies and nucleic acids of the invention as disclosed herein can be isolated. The terms “polynucleotide”, “polynucleotide sequence”, and “nucleic acid sequence” are used interchangeably herein. A “polynucleotide” as used herein refers to purine- and pyrimidine-containing polymers of any length, either polyribonucleotides or polydeoxyribonucleotides, which can be single or double stranded, such as, for example, DNA-DNA, DNA-RNA and RNA-RNA. A polynucleotide may optionally contain synthetic, non-natural or altered nucleotide bases. A polynucleotide in the form of a polymer of DNA may be comprised of one or more strands of cDNA, genomic DNA, synthetic DNA, or mixtures thereof. A “derivative” of a polypeptide as used herein will be understood to include polypeptides which have been subject to chemical modifications, including esterification, amidation, reduction, methylation, fusion to another peptide and the like. The polypeptide derivatives may be modified such that the modifications increase the stability and/or immunogenicity and/or bioavailability of the polypeptide derivative in comparison to the unmodified polypeptide. Covalent derivatives of the peptides or polypeptides of the invention can be prepared by linking the chemical moieties to functional groups on the amino acid side chains or at the N-terminus or C-terminus of the antigenic polypeptide. Conjugation of a polypeptide to another peptide may further be achieved by genetic means through the use of recombinant DNA techniques that are well know in the art, such as those set forth in the teachings of Sambrook et al. Molecular Cloning: A Laboratory Manual, 2 ed. Vol. 1, pp. 1.101-104, Cold Spring Harbor Laboratory Press, (1989) and F.M. Ausubel et al. Current Protocols in Molecular Biology, Eds. J.Wiley Press (2006), the relevant portions of which are incorporated herein by reference. A “variant” polypeptide of the invention can be a polypeptide which has an amino acid sequence which differs from the polypeptide encoded by SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8 or 9 due to the presence of one or more deletions, insertions, or substitutions of amino acid residues. In embodiments, a variant has at least 85%, 86%, 87%, 88%, 89%, preferably at least 90%, 91%, 92%, 93%, 94%, and more preferably 95%, 96%, 97%, 98%, 99% but less than 100% contiguous amino acid sequence identity to the corresponding polypeptide encoded by the nucleotide sequence as disclosed herein. Percentage identity may be determined using, for example computer programs as would be known by one skilled in the art. Variants can include polypeptides in which individual amino acids of the polypeptide of the invention are substituted by other amino acids which are closely related as understood in the art, for example, substitution of one hydrophobic residue such as isoleucine, valine, leucine or methionine for another, or the substitution of one polar residue for another, such as arginine for lysine, glutamic for aspartic acid or glutamine for asparagine. In embodiments, a fragment of a polypeptide of the present invention can consist of a truncated version of a polypeptide of the invention which has been truncated by 1, 2, 3, 4 or more than 5, more than 10, or more than 20 amino acids. An antigenic fragment may be generated using for example C-terminal deletion of any one of the polynucleotide sequences of the genes as listed in Table 1 or Table 2 and said C-terminal deletion constructs may then be inserted into a suitable prokaryotic or eukaryotic expression plasmid. The antigenic activity of the expression products derived from the constructs may then be tested by assessing reactivity with antisera from naturally and/or experimentally infected horse or foals using immunoblotting methods. Alternatively a series of synthetic polypeptide fragments with greater than 85%, greater than 90%, greater than 95%, or 100% sequence identity to portions of any one the polypeptides encoded by a polynucleotide sequence of a gene of Table 1 or more preferably Table 2 can be generated. These peptides may then be reacted with antisera from naturally or experimentally infected horses using an ELISA method to determine which peptide fragments are antigenic. Alternatively, synthetic peptides may be used to immunise, for example, mice, rabbits, or horses and the antisera produced can be assessed for reactivity with R. equi using indirect immunofluorescence assays. In this way immunogenic fragments may be identified and R. equi -specific antisera may be produced. These two latter approaches described are particularly advantageous for small peptides that contain linear, continuous epitopes. “Operably linked” means that a nucleic acid molecule is placed in functional relationship with another nucleic acid molecule. Generally an operably linked promoter will be linked such that it is contiguous with and in the same reading phase as the gene to be expressed. Generally the terms “treating”, “treatment” and the like are used to mean affecting a subject tissue or cell to obtain a desired pharmacological and/or physiological effect. As used herein, the term “treatment” and associated terms such as “treat” and “treating” means the reduction of the progression, severity and/or duration of infection or for the amelioration of at least one of the symptoms thereof by R. equi or may be prophylactic (preventative treatment). The term ‘treatment’ therefore refers to any regimen that can benefit a subject. References herein to “therapeutic” and “prophylactic” treatments are to be considered in their broadest context. The term “therapeutic” does not necessarily imply that a subject is treated until total recovery. Similarly, “prophylactic” does not necessarily mean that the subject will not eventually contract a disease condition. As used herein, the term “subject” refers to an animal, preferably a mammal and in particular a horse. FIGURES Embodiments of the present invention will now be described by way of example only with reference to the accompanying figures in which: FIG. 1 illustrates the R. equi pilus locus (rpl). (A) The 9 Kb rpl horizontally acquired (HGT) island (REQ18350-430) is absent from nonpathogenic Rhodococcus spp. (e.g. R. jostii RHA1 and R. erythropolis PR4). rpl genes have were detected in all R. equi clinical isolates (≈300 isolates tested). rpl gene products which are considered to be encoded are: A, prepilin peptidase; B, pilin subunit; C, TadE minor pilin; D, putative lipoprotein; E, CpaB pilus assembly protein; F, CpaE pilus assembly protein; GHI, Tad transport machinery. (B) Electron micrograph of R. equi 103S pili (indicated by arrowheads). Bar=0.5 μm. (C) R. equi pili visualized by immunofluorescence microscopy (×1,000 magnification). Reproduced from Letek et al. 2010, PLoS Genet. 6: e1001145). FIG. 2 illustrates a demonstration by targeted mutant construction and genetic re-complementation analysis that the rpl locus encodes the R. equi pilus. Negative staining transmission electron micrographs of wild-type R. equi 103S (WT) (panel A), isogenic rplB deletion mutant of 103S (ΔrplB, apiliated) (panel B), rplB-complemented mutant (piliated) (panel C), and mock-complemented mutant with an empty vector (no rplB gene). Bar=0.5 μm (panel D). FIG. 3 illustrates the effect of rplB gene deletion and complementation on R. equi adhesion to (A) macrophages (J774A.1 cell line) and (B) epithelial cells (HeLa cell line), two key target cell types in the pathogenesis of airborne lung infection. Data expressed as percentage of the control (WT); mean of at least three independent duplicate experiments±SEM. FIG. 4 illustrates the adhesion phenotype to (A) epithelial cells (HeLa cell line) and (B) macrophages (J774A.1 cell line) with additional rpl knock-out mutants (rplA and rplE). FIG. 5 illustrates Rpl pili are essential for R. equi lung colonization in mice as demonstrated using a novel in vivo lung infection model in mice developed by the inventors. It is based on a competitive virulence assay in which each mouse receives an intranasal inoculum containing 50% of wild-type (WT) R. equi bacteria and 50% of mutant (ΔrplB) R. equi bacteria. t=0 means 60 min after delivery of the intranasal inoculum. FIG. 6 illustrates production in rabbits of a specific antibody against the putative R. equi pilin subunit (RplB). (A) Amino acid sequence of putative RplB prepilin and of the C-terminal peptide used to raise a rabbit polyclonal antibody (boxed). Arrowhead indicates putative cleavage site of the prepilin. (B) Immunodetection of the RplB pilin by SDS-PAGE western blot analysis of whole cell extracts of wild-type R. equi (WT), an isogenic in-frame deletion rplB mutant (ΔrplB), the rplB-complemented mutant (ΔrplB+rplB), and a mock-complement mutant (ΔrplB+vector), using the anti-RplB peptide antibody (diluted 1:1,000; secondary antibody, alkaline phosphatase-conjugated mouse anti-rabbit monoclonal antibody, 1:10,000 diluted; reaction revealed with NBT/BCIP substrate. The anti-Rpl antibody specifically detects the Rpl pilin subunit in WT and re-completed rpl mutant, not in the apiliated rpl mutant and mock-complemented mutant. (C) Detection of Rpl pili production in R. equi by immunofluorescence using the anti-RplB peptide antibody and the same bacteria as in (B) (630× magnification, Leica AF6000 microscope). FIG. 7 illustrates Inhibition of R. equi attachment to (A) macrophages and (B) epithelial cells by an anti-RplB antibody. Prior to the adhesion assay, the antibody raised against the RplB (pilin subunit) peptide (see FIG. 6A ) was incubated for 60 min at 37° C. (40 μl/ml of a suspension in cell culture medium of exponentially grown R. equi bacteria at a density calculated for a multiplicity of infection of 15:1). As a control, the R. equi bacterial cell suspension was pre-incubated with an irrelevant antiserum (anti-Listeria monocytogenes rabbit polyclonal antibody). FIG. 8 illustrates RplB pilin antigens are recognized in vivo and elicit a strong antibody response in naturally infected foals. Representative example of the reactivity against the Rpl pilin of horse sera from bacteriologically confirmed cases of foal pneumonia, as determined by SDS-PAGE western blot analysis with whole cell extracts of wild-type R. equi (WT) and the isogenic ΔrplB mutant. All convalescent sera tested to date gave a strong reaction against the RplB pilin antigen whereas normal (non-case) sera did not. The Rpl pili dissociate into 18 kDa polypeptides that probably correspond to SDS-resistant homo-tetramers (predicted molecular mass of RplB pilin, 4.95 kDa) that remain non-covalently bound by strong monomer-monomer interactions via the N-terminal hydrophobic region of the pilin subunit. (A) indicates RplB is the first antigen detected in a curde R. equi protein preparation by the antibodies present in case sera. FIG. 9 illustrates variability of RplB amino acid sequence in R. equi strains and of other Rpl proteins. FIG. 10 illustrates the nucleotide sequences encoding Rpl proteins of other strains of R. equi. DETAILED DESCRIPTION OF THE INVENTION As indicated above, the inventors have identified polypeptides which play an important role in virulence of R equi and have used this knowledge to identify polypeptides which can be used to mediate an immune response in infected subjects, particularly horses, and in particular foals. Whilst the amino acid sequences of the polypeptides determined for the identified strain are noted, as will be understood, biologically active immunogenic fragments, derivatives or variants of such a polypeptide can also be used. As discussed variant polypeptides can comprise amino acid percent identity with the amino acid sequences disclosed herein. Alternatively, polypeptides of the invention may be encoded by variant nucleic acid sequences which have nucleotide percent identity with the polynucleotide sequences disclosed herein. The percent identity of two or more sequences may be determined by visual inspection and mathematical calculation. Alternatively, the percent identity of two nucleic acid sequences can be determined by comparing sequence information using the GAP computer program, version 6.0 described by Devereux et al. (Nucl. Acids Res. 12:387, 1984) and available from the University of Wisconsin Genetics Computer Group (UWGCG). The preferred default parameters for the GAP program include: (1) a unary comparison matrix (containing a value of 1 for identities and 0 for non-identities) for nucleotides, and the weighted comparison matrix of Gribskov and Burgess, Nucl. Acids Res. 14:6745, 1986, as described by Schwartz and Dayhoff, eds., Atlas of Protein Sequence and Structure, National Biomedical Research Foundation, pp. 353-358, 1979; (2) a penalty of 3.0 for each gap and an additional 0.10 penalty for each symbol in each gap; and (3) no penalty for end gaps. Other programs used by one skilled in the art of sequence comparison may also be used. Polypeptides of the invention may be prepared by any of a number of conventional techniques. A nucleic acid encoding a peptide or a biologically active immunogenic fragment, derivative, or variant thereof, may be subcloned into an expression vector for production of the polypeptide or fragment. The DNA sequence advantageously is fused to a sequence encoding a suitable leader or signal peptide and/or a promoter operable in a cell into which the nucleic acid is to be introduced. Alternatively, the desired fragment may be chemically synthesized using known techniques. DNA fragments also may be produced by restriction endonuclease digestion of a full length cloned DNA sequence, and isolated by electrophoresis on agarose gels. If necessary, oligonucleotides that reconstruct the 5′ or 3′ terminus to a desired point may be ligated to a DNA fragment generated by restriction enzyme digestion. Such oligonucleotides may additionally contain a restriction endonuclease cleavage site upstream of the desired coding sequence, and position an initiation codon (ATG) at the N-terminus of the coding sequence. Polymerase chain reaction (PCR) procedure also may be employed to isolate and amplify a DNA sequence encoding a desired polypeptide fragment. Oligonucleotides that define the desired termini of the DNA fragment are employed as 5′ and 3′ primers. The oligonucleotides may additionally contain recognition sites for restriction endonucleases, to facilitate insertion of the amplified DNA fragment into an expression vector. PCR techniques are described in Saiki et al., Science 239:487 (1988); Recombinant DNA Methodology, Wu et al., eds., Academic Press, Inc., San Diego (1989), pp. 189-196; and PCR Protocols: A Guide to Methods and Applications, Innis et al., eds., Academic Press, Inc. (1990). The invention encompasses polypeptides and biologically active immunogenic fragments, derivatives, or variants thereof in various forms, including those that are naturally occurring or produced through various techniques such as procedures involving recombinant DNA technology. For example, nucleotides encoding polypeptides of the invention can be derived from SEQ ID NO 1, 2, 3, 4, 5, 6, 7, 8, or 9 by in vitro mutagenesis, which includes site-directed mutagenesis, random mutagenesis, and in vitro nucleic acid synthesis. Such forms include, but are not limited to, derivatives, variants, and oligomers, as well as fusion proteins or fragments thereof. Polypeptide Derivatives Embodiments of a derivative of a polypeptide of the invention can comprise one or more non-naturally occurring amino acids or amino acid analogs, including non-genetically encoded L-amino acids, synthetic L-amino acids or D-enantiomers of an amino acid. Suitably, embodiments of a derivative can comprise one or more residues selected from the group consisting of: hydroxyproline, β-alanine, 2,3-diaminopropionic acid, α-aminoisobutyric acid, N-methylglycine (sarcosine), ornithine, citrulline, t-butylalanine, t-butylglycine, N-methylisoleucine, phenylglycine, cyclohexylalanine, norleucine, naphthylalanine, pyridylananine 3-benzothienyl alanine 4-chlorophenylalanine, 2-fluorophenylalanine, 3-fluorophenylalanine, 4-fluorophenylalanine, penicillamine, 1,2,3,4-tetrahydrotic isoquinoline-3-carboxylic acid β-2-thienylalanine, methionine sulfoxide, homoarginine, N-acetyl lysine, 2,4-diamino butyric acid, p-aminophenylalanine, N-methylvaline, homocysteine, homoserine, ε-amino hexanoic acid, δ-amino valeric acid, 2,3-diaminobutyric acid and mixtures thereof. Other amino acid residues that are useful for making the polypeptides and polypeptide derivatives described herein can be found, e.g., in Fasman, 1989, CRC Practical Handbook of Biochemistry and Molecular Biology, CRC Press, Inc., and the references cited therein. In embodiments, derivatives of polypeptides of the invention can also comprise an isostere of a polypeptide. The term “isostere” as used herein is intended to include a chemical structure that can be substituted for a second chemical structure because the steric conformation of the first structure fits a binding site specific for the second structure. The term specifically includes peptide back-bone modifications (i.e., amide bond mimetics) known to those skilled in the art. Such modifications include modifications of the amide nitrogen, the α-carbon, amide carbonyl, complete replacement of the amide bond, extensions, deletions or backbone crosslinks. Several peptide backbone modifications are known, including ψ[CH2S], ψ[CH2NH], ψ[CSNH2], ψ[NHCO], ψ[COCH2], and ψ[(E) or (Z) CH═CH]. In the nomenclature used above, ψ indicates the absence of an amide bond. The structure that replaces the amide group is specified within the brackets. Other modifications include, for example, an N-alkyl (or aryl) substitution (ψ[CONR]), or backbone crosslinking to construct lactams and other cyclic structures. In another example, a polypeptide derivative may be a retro-peptide analog. A retro-peptide analog comprises a reversed amino acid sequence of a polypeptide described herein. For example, a retro-peptide analog of a polypeptide comprises a reversed amino acid sequence of a sequence set forth in any one of SEQ ID NO 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. Retro-inverso polypeptides may be complete or partial. Complete retro-inverso peptides are those in which a complete sequence of a polypeptide described herein is reversed and the chirality of each amino acid in a sequence is inverted, other than glycine, because glycine does not have a chiral analog. Partial retro-inverso polypeptides are those in which only some of the peptide bonds are reversed and the chirality of only those amino acid residues in the reversed portion is inverted. For example, one or two or three or four or five or more than 10, more than 20, more than 30, more than 40 or more than 50 amino acid residues are D-amino acids. Suitably a polypeptide of and for use in the present invention may be further modified using at least one of C and/or N-terminal capping, and/or cysteine residue capping. Suitably, a polypeptide of and for use in the present invention may be capped at the N terminal residue with an acetyl group. Suitably, a polypeptide of and for use in the present invention may be capped at the C terminal with an amide group. Suitably, thiol groups of cysteines of polypeptides of the invention may be capped with acetamido methyl groups. In embodiments, the term derivative can include scrambled polypeptides comprising immunodominant epitopes of the rpl encoded pilus for example fragments of SEQ ID NOs 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. In embodiments derivatives can be encoded by rpl genes or fragments thereof which encode immunodominant epitopes of Rpl pilus provided in tandem, or as longer repeat stretches, for example concatemerized, to increase the immunogenicity of the encoded polypeptides. In embodiments, combinations of polypeptides of the invention (and corresponding nucleic acid sequences) can be fused in a single polypeptide. Polypeptide Synthesis A polypeptide or a biologically active immunogenic fragment, derivative, or variant thereof may be synthesized using any suitable chemical method known to the person skilled in the art. For example, synthetic peptides can be prepared using known techniques of solid phase, liquid phase, or peptide condensation, or any combination thereof, and can include natural and/or unnatural amino acids. Amino acids used for peptide synthesis may be standard Boc (Nα-amino protected Nα-t-butyloxycarbonyl) amino acid resin with the deprotecting, neutralization, coupling and wash protocols of the original solid phase procedure of Merrifield, J. Am. Chem. Soc., 85:2149-2154, 1963, or the base-labile Na-amino protected 9-fluorenylmethoxycarbonyl (Fmoc) amino acids described by Carpino and Han, J. Org. Chem., 37:3403-3409, 1972. Both Fmoc and Boc Nα-amino protected amino acids can be obtained from various commercial sources, such as, for example, Fluka, Bachem, Advanced Chemtech, Sigma, Cambridge Research Biochemical, Bachem, or Peninsula Labs. Generally, chemical synthesis methods comprise the sequential addition of one or more amino acids to a growing peptide chain. Normally, either the amino or carboxyl group of the first amino acid is protected by a suitable protecting group. The protected or derivatized amino acid can then be either attached to an inert solid support or utilized in solution by adding the next amino acid in the sequence having the complementary (amino or carboxyl) group suitably protected, under conditions that allow for the formation of an amide linkage. The protecting group is then removed from the newly added amino acid residue and the next amino acid (suitably protected) is then added, and so forth. After the desired amino acids have been linked in the proper sequence, any remaining protecting groups (and any solid support, if solid phase synthesis techniques are used) are removed sequentially or concurrently, to render the final polypeptide. By simple modification of this general procedure, it is possible to add more than one amino acid at a time to a growing chain, for example, by coupling (under conditions which do notracemize chiral centers) a protected tripeptide with a properly protected dipeptide to form, after deprotection, a pentapeptide. See, e.g., J. M. Stewart and J. D. Young, Solid Phase Peptide Synthesis (Pierce Chemical Co., Rockford, Ill. 1984) and G. Barany and R. B. Merrifield, The Peptides: Analysis, Synthesis, Biology, editors E. Gross and J. Meienhofer, Vol. 2, (Academic Press, New York, 1980), pp. 3-254, for solid phase peptide synthesis techniques; and M. Bodansky, Principles of Peptide Synthesis, (Springer-Verlag, Berlin 1984)and E. Gross and J. Meienhofer, Eds., The Peptides: Analysis. Synthesis. Biology, Vol. 1, for classical solution synthesis. Typical protecting groups include t-butyloxycarbonyl (Boc), 9-fluorenylmethoxycarbonyl (Fmoc) benzyloxycarbonyl (Cbz); p-toluenesulfonyl (Tx); 2,4-dinitrophenyl; benzyl (Bzl); biphenylisopropyloxycarboxy-carbonyl, t-amyloxycarbonyl, isobornyloxycarbonyl, o-bromobenzyloxycarbonyl, cyclohexyl, isopropyl, acetyl, o-nitrophenylsulfonyl and the like. Typical solid supports are cross-linked polymeric supports. These can include divinylbenzene cross-linked-styrene-based polymers, for example, divinylbenzene-hydroxymethylstyrene copolymers, divinylbenzene-chloromethylstyrene copolymers and divinylbenzene-benzhydrylaminopolystyrene copolymers. A peptide or a biologically active immunogenic fragment, derivative, or variant thereof as described herein according to any embodiment can also be chemically prepared by other methods such as by the method of simultaneous multiple peptide synthesis. See, e. g., Houghten Proc. Natl. Acad. Sci. USA 82: 5131-5135, 1985 or U.S. Pat. No. 4,631,211. Recombinant Polypeptide Production Alternatively, or in addition, a peptide or a biologically active immunogenic fragment, derivative, or variant thereof can be produced as a recombinant protein. To facilitate the production of a recombinant polypeptide, nucleic acid encoding the same is preferably isolated or synthesized. Typically the nucleic acid encoding the recombinant protein is/are isolated using a known method, such as, for example, amplification (e.g., using PCR or splice overlap extension) or isolated from nucleic acid from R. equi using one or more restriction enzymes or isolated from a library of nucleic acids. Methods for such isolation will be apparent to the ordinary skilled artisan and/or described in Ausubel et al (In: Current Protocols in Molecular Biology. Wiley Interscience, ISBN 047 150338, 1987), Sambrook et al (In: Molecular Cloning: Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratories, New York, Third Edition 2001). For expressing protein by recombinant means, a protein-encoding nucleic acid is placed in operable connection with a promoter or other regulatory sequence capable of regulating expression in a cell-free system or cellular system. For example, nucleic acid comprising a sequence that encodes a polypeptide of the pili of R. equi is placed in operable connection with a suitable promoter and maintained in a suitable cell for a time and under conditions sufficient for expression to occur. A number of other gene construct systems for expressing a nucleic acid of a gene selected from Table 1 or Table 2 in bacterial cells are well-known in the art and are described for example, in Ausubel et al (In: Current Protocols in Molecular Biology. Wiley Interscience, ISBN 047 150338, 1987), and Sambrook et al (In: Molecular Cloning: Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratories, New York, Third Edition 2001). A wide range of additional host/vector systems suitable for expressing a polypeptide of the present invention are available publicly, and described, for example, in Sambrook et al (In: Molecular cloning, A laboratory manual, second edition, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 1989). Following expression of a polypeptide, isolation and purification of the polypeptide may be accomplished by any suitable technique, as would be known in the art. Compositions A polypeptide or a biologically active immunogenic fragment, derivative, or variant thereof may be administered alone, but will preferably be administered as a pharmaceutical composition, which will generally comprise a suitable pharmaceutically acceptable excipient, diluent or carrier selected depending on the intended route of administration. Examples of suitable pharmaceutical carriers include; water, glycerol and ethanol. The term “carrier or excipient” as used herein, refers to a carrier or excipient that is conventionally used in the art to facilitate the storage, administration, and/or the biological activity of an active compound. A carrier may also reduce any undesirable side effects of the active compound. A suitable carrier is, for example, stable, e.g., incapable of reacting with other ingredients in the formulation. In one example, the carrier does not produce significant local or systemic adverse effect in recipients at the dosages and concentrations employed for treatment. Such carriers and excipients are generally known in the art. Suitable carriers for this invention include those conventionally used, e.g., water, saline, aqueous dextrose, and glycols are preferred liquid carriers, particularly (when isotonic) for solutions. Suitable pharmaceutical carriers and excipients include starch, cellulose, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, magnesium stearate, sodium stearate, glycerol monostearate, sodium chloride, glycerol, propylene glycol, water, ethanol, and the like. Pharmaceutical composition adapted for oral administration may be presented as discrete units such as capsules, soft gels, or tablets; powders or granules; solutions or suspensions in aqueous or non-aqueous liquids; edible foams or whips; or oil-in-water liquid emulsions or water-in-oil liquid emulsions. Pharmaceutical compositions provided as formulations adapted for parenteral administration include aqueous and non-aqueous sterile injection solutions which contain a polypeptide or a biologically active immunogenic fragment, derivative, or variant thereof or a antibody of the invention and optionally, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example sealed ampules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets. Administration As will be appreciated by a person of skill in the art, selecting an administration regimen for a therapeutic composition or vaccine of the invention depends on several factors, including the serum or tissue turnover rate of a polypeptide of the invention or an antibody invention, the level of symptoms, the immunogenicity of the polypeptide, and the accessibility of the target cells in the biological matrix. Preferably, an administration regimen maximizes the amount of therapeutic compound delivered to the subject consistent with an acceptable level of side effects. Accordingly, the amount of polypeptide, antibody or composition delivered depends in part on the polypeptide, antibody or composition and the severity of the condition being treated. A polypeptide or antibody can be provided, for example, by continuous infusion, or by doses at intervals of, e.g., one day, one week, or 1-7 times per week. A preferred dose protocol is one involving the maximal dose or dose frequency that avoids significant undesirable side effects. A total weekly dose depends on the type and activity of the compound being used. Determination of the appropriate dose is made by a veterinarian or clinician, for example using parameters or factors known or suspected in the art to affect treatment or predicted to affect treatment. EXAMPLES Example 1 Using electron microscopy and other microscopical techniques we demonstrated that R. equi produces long, thick and apparently rigid pili appendages, typically between two and four per bacteria cell ( FIG. 1 panels BC). Example 2 Genome Sequencing Genome sequencing of the complete genome sequence of R. equi strain 103S was determined in an international collaborative venture. The genome has just over 5 million base pairs and encodes 4598 genes of average length value 1009 pairs of nucleotides. Example 3 Demonstration that the rpl ( R. equi pili) locus (nucleotide positions 1,938,280 to 1,947,152, locus tags REQ18350-430) encodes the R. equi pilus by targeted mutant construction and genetic re-complementation analysis. An in-frame deletion mutant was constructed in the rplB gene putatively encoding the Rpl pilin subunit (RplB). Homologous recombination methodology previously devised (Navas et al. 2001, Identification and mutagenesis by allelic exchange of choE, encoding a cholesterol oxidase from the intracellular pathogen Rhodococcus equi . J. Bacteriol. 183: 4796-4805), and a novel suicide vector, pSelAct, for positive selection of double recombinants on 5-fluorocytosine (5-FC) (van der Geize et al. 2008, A novel method to generate unmarked gene deletions in the intracellular pathogen Rhodococcus equi using 5-fluorocytosine conditional lethality. Nucleic Acids Res. 36: el 51) was used in this approach. The ΔrplB mutant was complemented by stably inserting the rplB gene plus corresponding promoter region into the R. equi chromosome using the integrative vector pSET152 (Hong and Hondalus 2008, Site-specific integration of Streptomyces PhiC31 integrase-based vectors in the chromosome of Rhodococcus equi . FEMS Microbiol. Lett. 287: 63-68). As shown in FIG. 2 , the inactivation of the rplB gene results in loss of pili formation by R. equi . Pili formation is restored upon reintroduction of the rplB gene in the ΔrplB mutant but not by complementation with an empty vector, demonstrating that rplB is a gene directly responsible for the piliated phenotype. Example 4 Demonstration that the R. equi pili mediate attachment to mammalian cells. The ΔrplB mutant was tested in adhesion assays using monolayers of two cell types relevant to R. equi infection: epithelial cells to which the pathogen have to adhere to during the initial stages of lung colonization, and macrophages, which are used as host cells for bacterial intracellular replication. The rplB mutant was severely impaired in attachment to both eukaryotic cell types, and its complementation with the rplB gene but not an empty vector restored wild-type cytoadhesiveness ( FIG. 3 ). Two additional mutants were constructed in rplA and rplE ( FIG. 1A ) and they also caused a significant reduction of R. equi cytoadhesiveness ( FIG. 4 ), indicating that other genes from the rpl locus are involved in pilus-mediated attachment to eukaryotic cells (not shown). Example 5 Demonstration that the R. equi pili are essential for lung colonization in vivo in a mouse model of R. equi infection. A novel in vivo model of competitive R. equi lung infection in mice was developed and used to test the virulence of the rplB mutant in comparison to rplB-proficient (wild-type) bacteria. R. equi wild-type and an isogenic rplB knock-out mutant in equal amounts were inoculated intranasally to Balb/c mice. At specific time points after infection, the bacterial population was determined in lungs and tracheas to assess airway colonisation. The spleens were also analysed to determine the capacity of the bacteria to overwhelm local defences and spread deeper into host tissues. FIG. 4 shows that the mutant, initially accounting for 50% of the inoculum, was only detectable—in much less proportion—during the two first time points sampled (0 and 24 hour post inoculation), indicating that apiliated bacteria are immediately cleared from the lungs and thus substantially less virulent. In the first time point, only a very small fraction of the bacteria that translocated to the spleen were mutants. These data indicate that a wild-type capacity to attach to host cells via the Rpl pili is essential for host colonisation by R. equi. Example 6 Demonstration that the RplB (putative pilin subunit) protein is antigenic in vivo in rabbits. The synthetic RplB peptide indicated in FIG. 6A was used to hyperimmunize rabbits. The antiserum specifically detected the RplB pilin subunit in whole cell extracts of R. equi ( FIG. 6B ) and the production of Rpl pili in R. equi by immunofluorescence ( FIG. 6C ), indicating that it is immunogenic in vivo in rabbits. Example 7 Demonstration that RplB elicits neutralizing antibodies that inhibit R. equi attachment. The rabbit hyperimmune anti-RplB antiserum was used in attachment-inhibition assays in HeLa epithelial cells and J774A.1 macrophages. FIG. 7 shows that the RplB antiserum, but not an irrelevant antiserum, inhibited R. equi cytoadhesion. Given the key role of the Rpl pili in lung colonization by R. equi ( FIG. 4 ), these data indicate that RplB is a vaccine target to prevent lung infection by the pathogen. This is evidence that indicates that the pilin subunit RplB is recognised by the immune system in vivo and the animal body mounts a specific immune response with production of specific antibodies to the R. equi pilin subunit RplB. As the polyclonal antiserum containing anti-RplB antibodies inhibits attachment of R. equi to monolayers of HeLa epithelial cells or J774 macrophages if added to the infection assays, which effect is not seen if the Rpl antiserum is not added, or if an unrelated control antiserum raised against other bacteria (e.g. Listeria ) is used, this indicates a protective function of the antibodies through inhibition of bacterial attachment to host cells, the first phase of host colonisation during infection. Example 8 Demonstration that the RplB putative pilin subunit is an immunodominant antigen in naturally infected foals. Using SDS-PAGE western immunoblotting and whole-cell extracts from wild-type and rplB (apiliated) deletion mutant bacteria, it was shown that the sera from natural cases of R. equi infection in foals contain antibodies to the RplB putative pilin subunit ( FIG. 8 ). The RplB protein is the first detected in the crude R. equi protein preparation by the antibodies present in the case sera. Thus, the RplB pilin subunit is recognized in vivo by the foal's immune system during R. equi infection and is an immunodominant antigen. Normal, non-case sera did not react against the RplB protein, indicating that this antigen provides a suitable maker for the early detection and diagnosis of R. equi infection in foals. Although the invention has been particularly shown and described with reference to particular examples, it will be understood by those skilled in the art that various changes in the form and details may be made therein without departing from the scope of the present invention.

Rhodococcus equi ( R.equi ) has been determined to have a major adhesion factor encoded by a rpl pathogenicity island which enables host colonisation, wherein the rpl pathogenicity islandis absent from non-pathogenic Rhodococcus species. Further, the proteins (Rpl) encoded by the rpl pathogenicity islandhave been determined to be major immunodominant antigens. There is provided a novel diagnostic marker and vaccine candidate for R. equi in horses and other susceptible species.

BACKGROUND OF THE INVENTION The invention relates to an optical switching device comprising a first optical layer in which at least one optical waveguide having an entrance and an outlet is formed and a second piezoelectric layer associated with the first optical layer and electrodes for production of an acoustic wave provided on the second piezoelectric layer. This type of acoustic-optic switching device is known in the prior art. For example, so-called "bulk-Bragg cells" are frequently used in optics in order to cause a deflection in free beam technology or to cause a frequency shift of the light wave in an acousto-optical modulator. Integrated optical Bragg cells are known from the use of piezoelectric crystalline materials, such as Lithium niobate (LiNbO 3 ) as an integrated optical waveguide (R. G. Hunsberger: "Integrated optics: Theory and Technology", Springer-Verlag, Heidelberg, 1985; M. S. Wu: "Low-Loss ZnO Optical Waveguides for SAW-AO Applications", IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol. 36, No. 4, 442(1989)). Moreover an optical switch in a silicon substrate in the form of an interferometer is known. Thus, for example, in the article, "5 Ghz-spaced, Eight-channel, Guided-wave Tunable Multi/demultiplexer for Optical FDM Transmission Systems", Electronic Letters 23, No. 15,788(1987) an integrated optical waveguide made from silicon dioxide doped with titanium is disclosed, which forms a Mach-Zehnder Interferometer, whose one arm can be heated with the help of a thin layer resistance. A phase shift between both partial waves can result from a definite temperature increase, which leads to an optical coupling in one of two outlet waveguides according to choice during guiding in an integrated-optical directional coupler. Inorganic light-guiding materials, such as silicon dioxide, have only a comparatively small thermo-optic coefficient so that the switching function is connected with comparatively high heat input. The known optical switch, especially the above-mentioned bulk-Bragg cells, have the disadvantage that they are very large and are not useable in the vicinity of integrated-optical components. Moreover no switching between two spatially separated outlets during which an optical frequency shift can be performed at the same time may be accomplished with other optical switches known from the state of the art. The necessity for this exists, e.g., in heterodyne interferometery. SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved optical switching device of the above-described type which is not only useful to switch a light beam on and off, but also to switch a light beam from one outlet to another. These objects, and others which will be made more apparent hereinafter, are attained in an optical switching device comprising an optical layer in which at least one optical waveguide having an entrance and an outlet is formed, a piezoelectric layer associated with the optical layer and electrodes for producing an acoustic wave provided on the piezoelectric layer. According to the invention, the optical switching device includes at least one other optical waveguide having an outlet provided in the optical layer and means for performing a Bragg light deflection with optical frequency shift by one of activating and deactivating the electrodes to optically couple the entrance of the at least one optical waveguide with one of the outlet of the at least one optical waveguide and the outlet of the at least one other optical waveguide. The optical switching device according to the invention has the advantage that it is a compact structural component which not only can be used to switch on and off a light beam, but also to shift it from one outlet to another with a frequency shift at the same time. Because of that, an optical waveguide cooperates with another optical waveguide in an optical layer, so that a light wave is deflected into the other optical waveguide in the vicinity of an acoustic wave produced by means of a piezoelectric layer. Thus a switching from one output to the other may be accomplished by a simple activation and deactivation of the acoustic wave. Particularly a compact structure using only two layers is sufficient to accomplish this. Electrodes for producing the acoustic waves advantageously are provided on the opposite side of the piezoelectric layer from the optical layer. Understandably an electrode arrangement on the other side is also conceivable. Embodiments in which the electrodes are arranged on both sides of the piezoelectric layer or, alternatively, one on one side and one on the other provide the advantage that, on the one hand, redundancies and operating reliability are increased, while, on the other hand, an electrode arrangement acting as a detector results, which detects whether the other electrode arrangement is activated or deactivated. The use of an optical beam spreader, e.g. in the form of a Horn-Taper structure, or lens structures, at the entrance of the one optical waveguide, is particularly advantageous in order to improve and intensify deflection by the acoustic wave, whereby the spread light beam is concentrated or focused again to its normal size by a suitable light beam focusing device. The layers may be applied to a common substrate with the help of thin layer technology so that a very compact structure resulted. Advantageously silicon may be used as the substrate material so that a compatible process for semiconductor manufacture is possible which allows an additional monolithic integration of electronic functions. Moreover the micromechanical structuring of substrate material can be used in order to provide local structure for optical waveguides (glass fibers) and thus in order to guarantee an adjustment-free coupling of optical waveguides in the integrated optical chip. Advantageously the first optical layer includes doped silicon dioxide layers. The selection of separate layer systems for guidance of the light waves and for excitation of the sound waves advantageously allows the independent optimization of the optical and the piezoelectric properties of the systems. The invention also comprises an optical by-pass circuit including an optical layer which is provided with at least one optical waveguide having an entrance and an outlet and with at least one other optical waveguide having another entrance and another outlet; a piezoelectric layer arranged on the optical layer; a common substrate made of silicon on which the piezoelectric layer and the optical layer are mounted; electrodes for producing an acoustic wave, each of which are provided on one side or the other of the piezoelectric layer; means for detecting the acoustic wave including at least one of the electrodes to generate a suitable detection signal and means for performing a Bragg light deflection with optical frequency shift by one of activating and deactivating the electrodes to optically couple one of the entrance of the at least one optical waveguide and the entrance of the at least one other optical waveguide with one of the outlets. The at least one optical waveguide crosses the at least one other optical waveguide at an angle which corresponds to a Bragg deflection angle and the optical layer includes a number of doped silicon dioxide layers. The optical by-pass circuit according to the invention has the advantage that it is possible in a simple manner using the optical switching device according to the invention to provide a switching matrix with two entrances and two outlets. Thus coupling devices may be provided in some embodiments by which several optical entrances may be coupled according to choice with one of several optical outlets, whereby a fixed predetermined coupling between an entrance and an outlet exists in a deactivated state coupling device. Thus the switching device shifts into a stable state independently of other parameters during interference. In an advantageous way an optical fiber is associated with one entrance and an optical fiber is associated with its corresponding outlet, while a light source is arranged at another entrance and a light detector, at another outlet. A signal processing device cooperating with the light source and the light detector is by-passed by an optical coupling between both optical fibers in the deactivated state. Interference with this device does not lead to an interruption of the transmission from one optical fiber to another. Additional advantageous embodiments are described further in the appended dependent claims. BRIEF DESCRIPTION OF THE DRAWING The objects, features and advantages of the invention will now be illustrated in more detail with the aid of the following description of the preferred embodiments, with reference to the accompanying figures in which: FIG. 1 is a schematic perspective view of one embodiment of an optical switching device according to the invention; FIG. 2 is a block diagram showing an application of an optical switching device according to the invention; and FIG. 3 is a schematic diagram of an optical by-pass circuit according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical switching device 1 is schematically illustrated in FIG. 1 and has a substrate layer 3, advantageously made of silicon, to which an optical layer 5 is applied. Particularly the known standard thin layer technology is suitable for the application process. The figure does not show that the optical layer 5 is formed as a layer system. The optical layer 5 is advantageously formed from a plurality of differently doped silicon dioxide layers, which guarantee vertical light guidance because of their different refractive indices. Lateral light guide means can also be provided in a simple way by a suitable lateral structuring of the layer system, which, e.g., can be attained by plasma etching. A piezoelectric layer 7 is arranged on this light guiding optical layer 5. It can be made, for example, by sputtering of zinc oxide or aluminum nitride. Understandably a plurality of other material systems and layer technologies can also be used, such as deposition of lead-zirconate-titanate layers in a sol-gel process. Besides the arrangement of the piezoelectric layer 7 on the optical layer 5 understandably also this layer may be arranged under the optical layer 5. An electrode arrangement 9 in the form of an interdigital converter is provided on the piezoelectric layer 7. An acoustic surface wave, which propagates in the Y-direction in FIG. 1, may be excited in the piezoelectric layer 7 by coupling of a high frequency in the electrode arrangement. Both a Rayleigh-mode and also modes of higher order (Sezawa-mode) can be used here as acoustic waves. These acoustic surface waves spread in the optical layer 5 and lead there to periodic index of refraction changes. The period corresponds to the wavelength of the sound wave. The index of refraction change results, because of a periodic spatial oscillation of a dynamic optical grid in which the light waves are deflected. As a result of the large lateral spreading of the sound wave, the grid may be represented by a Bragg grid, so that the angular deflection corresponds to twice the Bragg angle 2Θ B , wherein Θ B is given by: 2·Λ·sin Θ.sub.B =λ. Here Λ is the acoustic wavelength and λ is the optical wavelength of a light source in the optical layer 5, which is connected with the wavelength λ 0 in vacuo with λ=λ.sub.0 /neff. A Bragg angle Θ B of about 1.5° results with the usual light wavelengths of λ 0 ≅1.3 to 1.5 μm and acoustic surface waves with Λ≅20 μm when a silicon dioxide layer is used as the optical material with a refractive index of about 1.5. This effect is used in the circuit device shown in FIG. 1 for switching from one outlet to the other. A light waveguide or optical waveguide 11 is also provided in the optical layer 5, which connects an entrance 13 optically with an outlet 15. This optical waveguide 11 is arranged at an angle of Θ relative to the schematically illustrated wave front 17. An additional optical waveguide 21 is provided extending from this first optical waveguide 11 in a surface wave region 19, which opens into a second outlet 23. Also this optical waveguide is arrange at an angle of Θ relative to the wave front line 25. An optical fiber 27 is coupled to the entrance 13 for input of the light beam, while optical fibers 29.1 and 29.2 are associated with the outlets 15 and 23. The light beam input into the optical waveguide 11 is guided directly to the output 15 with the electrode arrangement deactivated, which means in the absence of a surface wave. When the electrode arrangement is activated the above-mentioned surface wave forms, which leads, as described above, to a deflection of the light beam about 2Θ. Thus an input light wave is deflected in the vicinity 19 about this angle and thus guided by means of the suitable arrangement of the light wave guide 21 to the output 23. Thus a switching between both outlets 15 and 23 is possible by activation and deactivation of the electrode arrangements. FIG. 2 shows an example of an application of the optical switching device according to the invention, which is a component of a participating node of an optical communication network, e.g. a local network. In one such network several participating stations are connected by a fixed data bus with each other. This data bus is an optical fiber in an optical network. In FIG. 2 one sees that a participating station 30 is connected with another downstream unshown participating station by an optical fiber 31.1 and with an additional upstream unshown participating station by an optical fiber 31.2. A signal processing device 33 is provided as an interface between the participating station 30 and the optical data bus 31. This signal processing device 33 controls an optical switching device 35, whose first entrance 37 is associated with the optical fiber 31.1 and whose first outlet 39 is associated with the optical fiber 31.2. FIG. 2 however shows that the optical switching device 35 has a second entrance 41, which is associated with a light source 43, for example a laser diode. The optical switching device 35 has a second outlet 45 available which is associated with a light detector 47. Both the transmitting device 43 and also the detector 47 are connected with the signal processing device 33. The participating node thus operates in the standard case so that the data coming over the optical fiber 31.1 are conducted to the detector 47 as shown by a dashed optical connection 51 in the optical switching device 35. The corresponding electronically converted data then reach the signal processing device 33, which filters out the information designed for the participating station 30 from the data stream, and newly added information and the data stream modified in this way is transmitted by the transmitting device 43 and over the optical connection 53 formed in the optical switching device 35 to the optical fiber 31.2 so that the data then reaches the downstream participating station. This data transmission from the upstream to the downstream participating station depends on the operational effectiveness of the signal processing device 33. In case this fails because of a voltage interruption, the network is paralyzed, since the incoming data cannot reach the optical fiber 31.2. In order to guarantee a friction-less operation of a network, an optical switching device is made by combination of two optical switching devices according to FIG. 1, which guarantees the two-dimensional connections 51,53 in the activated state. In the deactivated state, which for example occurs during a voltage drop, the optical switching device 35 is however switched so that a connection 54 is made between a first input 37 and a first outlet 39. Thus the data stream can flow to the downstream participating station avoiding the participating station 30 and the signal processing apparatus 33. The exact structure of this optical switching device is shown diagrammatically in FIG. 3. This optical switching device has substantially the same layers, as the optical switching device according to FIG. 1. A more detailed illustration is therefore not necessary. The embodiment shown in FIG. 3 differs from the optical switching device shown in FIG. 1, because of the presence of the additional optical waveguide 11.2 in the optical layer besides the optical waveguide 11.1. This optical waveguide 11.2 has an entrance 37 and an outlet 39 and it is superimposed on the optical waveguide 21 (FIG. 1) in the lower region. To guarantee the desired operation it is necessary that both optical waveguides 11.1 and 11.2 cross each other. The angle between these waveguides 11.1 and 11.2 is a Bragg-deflection angle of 2Θ B . On activation of an electrode arrangement, which means an acoustic surface wave is present, a light beam 55 is deflected in the Bragg grid about an angle 2Θ B and is conducted to outlet 45 by means of the corresponding optical waveguide. Thus an optical connection is made between the entrance 37 and the outlet 45. A light beam 57 is deflected about the same angle so that it is guided to the outlet 39 over the optical waveguide 21(11.2), as in the embodiment according to FIG. 1. Consequently an optical connection between the entrance 41 and the outlet 39 is obtained. Soon the electrode arrangement 9 is deactivated, which results in the absence of the acoustic surface waves necessary for bending, so that the light waves or light beams travel to the outlets diagonally across from the entrances. That means that the entrance 37, for example, is optically connected with the outlet 39. Thus an optical by-pass circuit is formed in a simple way by combination of two optical switching device shown in FIG. 1. FIG. 3 allows for detection so that the optical wave must be spread out with the acoustic surface waves in the region acting to cause the deflection, so that they extend laterally over several grid periods in order to guarantee a high deflection coefficient. An arrangement is provided in which the beam spreading is caused by a "so-called" Horn-Taper structure. The light beam or wave is reduced again in its lateral extent to its original width by inverse structuring at the outlet side of the optical waveguide crossing point. The disclosure in German Patent Application 196 16 934.8 of Apr. 27, 1996 is incorporated here by reference. This German Patent Application also discloses the invention described above and claimed in the claims appended hereinbelow and forms the basis for a claim of priority for the instant invention based on 35 U.S.C. 119. While the invention has been illustrated and described as embodied in a optical switching device, it is not intended to be limited to the details shown, since various modifications and changes may be made without departing in any way from the spirit of the present invention. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. What is claimed is new and is set forth in the following appended claims.

The optical switching device includes an optical layer (5) provided with at least one optical waveguide (11) having an entrance (13) and an outlet (15) and at least one other optical waveguide (21) provided in the optical layer (5) with another outlet (23); a piezoelectric layer (7) arranged on the optical layer (5); electrodes (9) for producing an acoustic wave provided on the piezoelectric layer (7); and a device for performing a Bragg light deflection with optical frequency shift by one of activating and deactivating the electrodes to optically couple the entrance (13) of the at least one optical waveguide (11) with one or the other of the outlets (15, 23). The invention also relates to an optical by-pass circuit which is a combination of two optical switching devices.

FIELD OF THE INVENTION [0001] The present invention relates to hydrophobic peptides and/or peptidomimetics capable of forming a (nanofibrous) hydrogel and hydrogels comprising said hydrophobic peptides and/or peptidomimetics and to various uses, such as in regenerative medicine, injectable therapies, delivery of bioactive moieties, wound healing, 2D and 3D synthetic cell culture substrate, biosensor development, biofunctionalized surfaces, and biofabrication. BACKGROUND OF THE INVENTION [0002] Self-assembly is an elegant and expedient “bottom-up” approach towards designing ordered, three-dimensional and biocompatible nanobiomaterials. Reproducible macromolecular nanostructures can be obtained due to the highly specific interactions between the building blocks. These intermolecular associations organize the supramolecular architecture and are mainly non-covalent electrostatic interactions, hydrogen bonds, van der Waals forces, etc. Supramolecular chemistry or biology gathers a vast body of two or three dimensional complex structures and entities formed by association of chemical or biological species. These associations are governed by the principles of molecular complementarity or molecular recognition and self-assembly. The knowledge of the rules of intermolecular association can be used to design polymolecular assemblies in form of membranes, films, layers, micelles, tubules, gels for a variety of biomedical or technological applications (J.-M. Lehn, Science, 295, 2400-2403, 2002). [0003] Peptides are versatile building blocks for fabricating supramolecular architectures. Their ability to adopt specific secondary structures, as prescribed by amino acid sequence, provides a unique platform for the design of self-assembling biomaterials with hierarchical three-dimensional (3D) macromolecular architectures, nanoscale features and tuneable physical properties (S. Zhang, Nature Biotechnology, 21, 1171-1178, 2003). Peptides are for instance able to assemble into nanotubes (U.S. Pat. No. 7,179,784) or into supramolecular hydrogels consisting of three dimensional scaffolds with a large amount of around 98-99% immobilized water or aqueous solution. The peptide-based biomaterials are powerful tools for potential applications in biotechnology, medicine and even technical applications. Depending on the individual properties these peptide-based hydrogels are thought to serve in the development of new materials for tissue engineering, regenerative medicine, as drug and vaccine delivery vehicles or as peptide chips for pharmaceutical research and diagnosis (E. Place et al., Nature Materials, 8, 457-470, 2009). There is also a strong interest to use peptide-based self-assembled biomaterial such as gels for the development of molecular electronic devices (A. R. Hirst et al. Angew. Chem. Int. Ed., 47, 8002-8018, 2008). [0004] A variety of “smart peptide hydrogels” have been generated that reaction external manipulations such as temperature, pH, mechanical influences or other stimuli with a dynamic behavior of swelling, shrinking or decomposing. Nevertheless, these biomaterials are still not “advanced” enough to mimic the biological variability of natural tissues as for example the extracellular matrix (ECM) or cartilage tissue or others. The challenge for a meaningful use of peptide hydrogels is to mimic the replacing natural tissues not only as “space filler” or mechanical scaffold, but to understand and cope with the biochemical signals and physiological requirements that keep the containing cells in the right place and under “in vivo” conditions (R. Fairman and K. Akerfeldt, Current Opinion in Structural Biology, 15, 453-463, 2005). [0005] Much effort has been undertaken to understand and control the relationship between peptide sequence and structure for a rational design of suitable hydrogels. In general hydrogels contain macroscopic structures such as fibers that entangle and form meshes. Most of the peptide-based hydrogels utilize 0-pleated sheets which assemble to fibers as building blocks (S. Zhang et al., PNAS, 90, 3334-3338, 1993: A. Aggeli et al., Nature, 386, 259-262, 1997, etc.). It is also possible to obtain self-assembled hydrogels from α-helical peptides besides 0-sheet structure-based materials (W. A. Petka et al., Science, 281, 389-392, 1998; C. Wang et al., Nature, 397, 417-420, 1999; C. Gribbon et al., Biochemistry, 47, 10365-10371, 2008; E. Banwell et al., Nature Materials, 8, 596-600, 2009, etc.). [0006] Nevertheless, the currently known peptide hydrogels are in most of the cases associated with low rigidity, sometimes unfavourable physiological properties and/or complexity and the requirement of substantial processing thereof which leads to high production costs. There is therefore a widely recognized need for peptide hydrogels that are easily formed, non-toxic and have a sufficiently high rigidity for standard applications. The hydrogels should also be suitable for the delivery of bioactive moieties (such as nucleic acids, small molecule therapeutics, cosmetic and anti-microbial agents) and/or for use as biomimetic scaffolds that support the in vivo and in vitro growth of cells and facilitate the regeneration of native tissue and/or for use in 2D and/or 3D biofabrication. [0007] “Biofabrication” utilizes techniques such as additive manufacturing (i.e. printing) and moulding to create 2D and 3D structures from biomaterial building blocks. During the fabrication process, bioactive moieties and cells can be incorporated in a precise fashion. In the specific example of “bio-printing”, a computer-aided device is used to precisely deposit the biomaterial building block (ink), using a layer-by-layer approach, into the pre-determined, prescribed 3D geometry. The size of these structures range from the micro-scale to larger structures. Additives such as growth factors, cytokines, vitamins, minerals, oligonucleotides, small molecule drugs, and other bioactive moieties, and various cell types can also be accurately deposited concurrently or subsequently. Bio-inert components can be utilized as supports or fillers to create open inner spaces to mimic biological tissue. Such biological constructs can be subsequently implanted or used to investigate the interactions between cells and/or biomaterials, as well as to develop 3D disease models. In the specific example of “moulding”, the biomaterial building block is deposited into a template of specific shape and dimensions, together with relevant bioactive moieties and cells (Malda J., et al. Engineering Hydrogels for Biofabrication. Adv. Mater. (2013); Murphy S. V., et al. Evaluation of Hydrogels for Bio-printing Applications. J. of Biomed. Mater. Res. (2012)). SUMMARY OF THE INVENTION [0008] It is therefore desirable to provide a biocompatible compound that is capable of forming a hydrogel, that meets at least some of the above requirements to a higher extent than currently available hydrogels and that is not restricted by the above mentioned limitations. [0009] The objects of the present invention are solved by a hydrophobic peptide and/or peptidomimetic capable of forming a (nanofibrous) hydrogel, the hydrophobic peptide and/or peptidoinimetic having the general formula II: [0000] Z—(X) a —Z′ b   II wherein Z is an N-terminal protecting group; X is a hydrophobic amino acid sequence of aliphatic amino acids, which, at each occurrence, are independently selected from the group consisting of aliphatic amino acids and aliphatic amino acid derivatives; a is an integer selected from 2 to 6, preferably 2 to 5; Z′ is a C-terminal group; and b is 0 or 1. [0016] The inventors have found that said aliphatic amino acids and aliphatic amino acid derivatives need to exhibit an overall decrease in hydrophobicity from the N-terminus to the C-terminus of said peptide and/or peptidomimetic in order to form nanofibrous hydrogels. [0017] The terms “peptoid” and “peptidomimetic” are used herein interchangeably and refer to molecules designed to mimic a peptide. Peptoids or peptidomimetics can arise either from modification of an existing peptide, or by designing similar systems that mimic peptides. These modifications involve changes to the peptide that will not occur naturally (such as altered backbones and/or the incorporation of non-natural amino acids). [0018] In particular, peptoids are a subclass of peptidomimetics. In peptoids, the side chains are connected to the nitrogen of the peptide backbone, differently to normal peptides. Peptidomitnetics can have a regular peptide backbone where only the normally occurring amino acids are exchanged with a chemically different but similar amino acids, such as leucine to norleucine. In the present disclosure, the terms are used interchangeably. [0019] In one embodiment, said aliphatic amino acids and aliphatic amino acid derivatives are either D-amino acids or L-amino acids. [0020] In one embodiment, said aliphatic amino acids are selected from the group consisting of alanine (Ala, A), homoallylglycine, homopropargylglycine, isoleucine (Ile, I), norleucine, leucine (Leu, L), valine (Val, V) and glycine (Gly, G), preferably from the group consisting of alanine (Ala, A), isoleucine (Ile, I), leucine (Leu, L), valine (Val, V) and glycine (Gly, G). [0021] In one embodiment, all or a portion of said aliphatic amino acids are arranged in an order of decreasing amino acid size in the direction from N- to C-terminus, wherein the size of the aliphatic amino acids is defined as I=L>V>A>G. [0022] In one embodiment, said aliphatic amino acids arranged in an order of decreasing amino acid size have a sequence which is a non-repetitive sequence. [0023] In one embodiment, the very first N-terminal amino acid of said aliphatic amino acids is less crucial (it can be G, V or A). The inventors found that this specific first amino acid has not a dominant on this otherwise mandatory requirement of decreasing hydrophobicity from N- to C-terminus. [0024] In one embodiment, the first N-terminal amino acid of said aliphatic amino acids is G, V or A. [0025] In one embodiment, said aliphatic amino acids have a sequence selected from [0000] (SEQ ID NO: 1) ILVAG (SEQ ID NO: 2) LIVAG, (SEQ ID NO: 3) IVAG, (SEQ ID NO: 4) LVAG, (SEQ ID NO: 5) ILVA, (SEQ ID NO: 6) LIVA, (SEQ ID NO: 13) IVG, (SEQ ID NO: 14) VIG, (SEQ ID NO: 15) IVA, (SEQ ID NO: 16) VIA, (SEQ ID NO: 17) VI and (SEQ ID NO: 18) IV, wherein, optionally, there is an G, V or A preceding such sequence at the N-terminus, such as [0000] (SEQ ID NO. 7) AIVAG, (SEQ ID NO. 8) GIVAG, (SEQ ID NO. 9) VIVAG, (SEQ ID NO. 10) ALVAG, (SEQ ID NO. 11) GLVAG, (SEQ ID NO. 12) VLVAG. [0026] In one embodiment, (X) a has a sequence selected from the group consisting of SEQ ID NOs. 1 to 18, [0000] preferably the sequence with SEQ ID NO: 1 and SEQ ID NO: 2. [0027] In one embodiment, all or a portion of the aliphatic amino acids are arranged in an order of identical amino acid size, preferably wherein said aliphatic amino acids arranged in order of identical amino acid size have a sequence with a length of 2 to 4 amino acids. [0028] For example, said aliphatic amino acids arranged in an order of identical size have a sequence selected from LLLL, LLL, LL, IIII, III, II, VVVV, VVV, VV, AAAA, AAA, AA, GGGG, GGG, and GG. [0029] In one embodiment, said N-terminal protecting group Z has the general formula —C(O)—R, [0000] wherein R is selected from the group consisting of H, unsubstituted or substituted alkyls, and unsubstituted or substituted aryls, wherein R is preferably selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl and isobutyl. [0030] In one embodiment, said N-terminal protecting group Z is an acetyl group. [0031] In one embodiment, said N-terminal protecting group Z is a peptidomimetic molecule, including natural and synthetic amino acid derivatives, wherein the N-terminus of said peptidomimetic molecule may be modified with a functional group selected from the group consisting of carboxylic acid, amide, alcohol, aldehyde, amine, imine, nitrile, an urea analog, phosphate, carbonate, sulfate, nitrate, maleimide, vinyl sulfone, azide, alkyne, alkene, carbohydrate, imide, peroxide, ester, aryl, ketone, sulphite, nitrite, phosphonate, and silane. [0032] In one embodiment, said C-terminal group Z′ is a non-amino acid, preferably selected from the group of small molecules, functional groups and linkers. Such C-terminal groups Z′ can be polar or non-polar moieties used to functionalize the peptide and/or peptidomimetic of the invention. [0033] In one embodiment, said C-terminal group Z′ is selected from functional groups, such as polar or non-polar functional groups, such as (but not limited to) —COOH, —COOR, —COR, —CONHR or —CONRR′ with R and R′ being selected from the group consisting of H, unsubstituted or substituted alkyls, and unsubstituted or substituted aryls, —NH 2 , —OH, —SH, —CHO, maleimide, imidoester, carbodiimide ester, isocyanate; small molecules, such as (but not limited to) sugars, alcohols, hydroxy acids, amino acids, vitamins, biotin; linkers terminating in a polar functional group, such as (but not limited to) ethylenediamine, PEG, carbodiimide ester, imidoester; linkers coupled to small molecules or vitamins, such as biotin, sugars, hydroxy acids, [0044] In one embodiment, wherein said C-terminal group Z′ can be used for chemical conjugation or coupling of at least one compound selected from bioactive molecules or moieties, such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides; label(s), dye(s), such as fluorescent or radioactive label(s), imaging contrast agents; pathogens, such as viruses, bacteria and parasites; micro- and nanoparticles or combinations thereof wherein said chemical conjugation can be carried out before or after self-assembly of the peptide and/or peptidomimetic. [0053] In one embodiment, the C-terminus of the peptide and/or peptidomimetic is functionalized (without the use of a C-terminal group or linker), such as by chemical conjugation or coupling of at least one compound selected from bioactive molecules or moieties, such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides; label(s), dye(s), such as fluorescent or radioactive label(s), imaging contrast agents; pathogens, such as viruses, bacteria and parasites; micro- and nanoparticles or combinations thereof wherein said chemical conjugation can be carried out before or after self-assembly of the peptide and/or peptidomimetic. [0062] In one embodiment, said C-terminal group Z′ is a peptidomimetic molecule, including natural and synthetic amino acid derivatives, wherein the C-terminus of said peptidomimetic molecule may be modified with a functional group selected from the group consisting of carboxylic acid, amide, alcohol, aldehyde, amine, imine, nitrile, an urea analog, phosphate, carbonate, sulfate, nitrate, maleimide, vinyl sulfone, azide, alkyne, alkene, carbohydrate, imide, peroxide, ester, aryl, ketone, sulphite, nitrite, phosphonate, and silane. [0063] In one embodiment, the hydrophobic peptide and/or peptidomimetic according to the invention is being stable in aqueous solution at physiological conditions at ambient temperature for a period of time in the range from 1 day to at least 6 months, preferably to at least 8 months more preferably to at least 12 months. [0064] In one embodiment, the hydrophobic peptide and/or peptidomimetic according to the invention is being stable in aqueous solution at physiological conditions, at a temperature up to 90° C., for at least 1 hour. [0065] The objects of the present invention are solved by a composition or mixture comprising [0000] (a) at least one hydrophobic peptide and/or peptidomimetic of the present invention, and (b) at least one hydrophobic peptide and/or peptidomimetic capable of forming a hydrogel, the hydrophobic peptide and/or peptidomimetic having the general formula: [0000] Z—(X) a —N′ b wherein Z is as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; X is as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; a is as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; N′ is a non-polar C-terminal group which differs from Z′, the polar C-terminal group as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; and is preferably carboxylic acid, amide, alcohol, biotin, inaleimide, sugars, and hydroxyacids, and b is 0 or 1. [0074] The objects of the present invention are solved by a hydrogel comprising the hydrophobic peptide and/or peptidomimetic of the present invention. [0075] In one embodiment, the hydrogel is stable in aqueous solution at ambient temperature for a period of at least 7 days, preferably at least 2 to 4 weeks, more preferably at least 1 to 6 months. [0076] In one embodiment, the hydrogel is characterized by a storage modulus G′ to loss modulus G″ ratio that is greater than 2. [0077] In one embodiment, the hydrogel is characterized by a storage modulus G′ from 100 Pa to 80,000 Pa at a frequency in the range of from 0.02 Hz to 16 Hz. [0078] In one embodiment, the hydrogel has a higher mechanical strength than collagen or its hydrolyzed form (gelatin). [0079] The objects of the present invention are solved by a hydrogel comprising [0000] (a) at least one hydrophobic peptide and/or peptidomimetic of the present invention, and (b) at least one hydrophobic peptide and/or peptidomimetic with a non-polar head group. [0080] Said at least one “hydrophobic peptide and/or peptidomimetic with a non-polar head group” is capable of forming a hydrogel and has the general formula: [0000] Z—(X) a —N′ b wherein Z, X and a are as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; N′ is a non-polar C-terminal group which differs from Z′, the polar C-terminal group as defined herein for the hydrophobic peptide and/or peptidomimetic of the present invention; and is preferably carboxylic acid, amide, alcohol, biotin, maleimide, sugars, and hydroxyacids, and b is 0 or 1. [0087] In one embodiment, the hydrogel comprises fibers of the hydrophobic peptide and/or peptidomimetic of the invention or fibers of the hydrophobic peptide and/or peptidomimetic with a non-polar head group as defined above, said fibers defining a network that is capable of entrapping at least one of a microorganism, a virus particle, a peptide, a peptoid, a protein, a nucleic acid, an oligosaccharide, a polysaccharide, a vitamin, an inorganic molecule, a synthetic polymer, a small organic molecule, a micro- or nanoparticle or a pharmaceutically active compound. [0088] In one embodiment, the hydrogel comprises at least one of a microorganism, a virus particle, a peptide, a peptoid, a protein, a nucleic acid, an oligosaccharide, a polysaccharide, a vitamin, an inorganic molecule, a synthetic polymer, a small organic molecule, a micro- or nanoparticle or a pharmaceutically active compound entrapped by the network of fibers of the hydrophobic polymer. [0089] In one embodiment, the fibers of the hydrophobic polymer are coupled to the at least one of a microorganism, a virus particle, a peptide, a peptoid, a protein, a nucleic acid, an oligosaccharide, a polysaccharide, a vitamin, an inorganic molecule, a synthetic polymer, a small organic molecule, a micro- or nanoparticle or a pharmaceutically active compound entrapped by the network of fibers of the amphiphilic polymer. [0090] In one embodiment, the hydrogel is comprised in at least one of a fuel cell, a solar cell, an electronic cell, a biosensing device, a medical device, an implant, a pharmaceutical composition and a cosmetic composition. [0091] In one embodiment, the hydrogel is injectable. [0092] The objects of the present invention are solved by the use of the hydrogel according to the present invention in at least one of the following: release of a pharmaceutically active compound and/or delivery of bioactive moieties, medical tool kit, a fuel cell, a solar cell, an electronic cell, regenerative medicine and tissue regeneration, wound healing, 2D and 3D synthetic cell culture substrate, stem cell therapy, injectable therapies, biosensor development, biofunctionalized surfaces, biofabrication, such as bio-printing, and gene therapy. [0107] For the uses, we also refer to the uses in biofabrication described in the inventors' parallel application “Self-assembling peptides, peptidomimetics and peptidic conjugates as building blocks for biofabrication and printing”, having the same filing date as the present application, and the subsequent embodiments and methods described therein, which also apply to the hydrophobic peptides and/or peptidomimetics of this invention. [0108] The objects of the present invention are solved by a method of preparing a hydrogel, the method comprising dissolving a hydrophobic peptide and/or peptidomimetic according to the present invention in an aqueous solution. [0109] In one embodiment, the dissolved hydrophobic peptide and/or peptidomimetic in aqueous solution is further exposed to temperature, wherein the temperature is in the range from 20° C. to 90° C., preferably from 20° C. to 70° C. [0110] In one embodiment, the hydrophobic peptide and/or peptidomimetic is dissolved at a concentration from 0.01 μg/ml to 100 mg/ml, preferably at a concentration from 1 mg/ml to 50 mg/ml, more preferably at a concentration from about 1 mg/ml to about 20 mg/ml. [0111] The objects of the present invention are solved by a method of preparing a hydrogel, the method comprising dissolving a hydrophobic peptide and/or peptidomimetic according to the present invention and a hydrophobic peptide and/or peptidomimetic with a non-polar head group as defined herein in an aqueous solution. [0112] The objects of the present invention are solved by a wound dressing or wound healing agent comprising a hydrogel according to the invention. [0113] The objects of the present invention are solved by a surgical implant, or stent, the surgical implant or stent comprising a peptide and/or peptidomimetic scaffold, wherein the peptide and/or peptidomimetic scaffold is formed by a hydrogel according to the invention. [0114] The objects of the present invention are solved by a pharmaceutical and/or cosmetic composition and/or a biomedical device and/or electronic device comprising the hydrophobic peptide and/or peptidomimetic according to the invention. [0115] The objects of the present invention are solved by a pharmaceutical and/or cosmetic composition and/or a biomedical device and/or electronic device comprising the hydrophobic peptide and/or peptidomimetic of the present invention and the hydrophobic peptide and/or peptidomimetic with a non-polar head group as defined herein. [0116] In one embodiment, the pharmaceutical and/or cosmetic composition and/or the biomedical device, and/or the electronic devices further comprises a pharmaceutically active compound. [0117] In one embodiment, the pharmaceutical and/or cosmetic composition is provided in the form of a topical gel or cream, a spray, a powder, or a sheet, patch or membrane, or wherein the pharmaceutical and/or cosmetic composition is provided in the form of an injectable solution. [0118] In one embodiment, the pharmaceutical and/or cosmetic composition further comprises a pharmaceutically acceptable carrier. [0119] The objects of the present invention are solved by a kit of parts, the kit comprising a first container with a hydrophobic peptide and/or peptidomimetic according to the invention and a second container with an aqueous solution. [0120] In one embodiment, the kit further comprises a third container with a hydrophobic peptide and/or peptidomimetic with a non-polar head group as defined herein. [0121] In one embodiment, the aqueous solution of the second container further comprises a pharmaceutically active compound. [0000] and/or wherein the first and/or third container with a hydrophobic peptide and/or peptidomimetic further comprises a pharmaceutically active compound. [0122] The objects of the present invention are solved by an in vitro or in vivo method of tissue regeneration comprising the steps: (a) providing a hydrogel according to the invention, (b) exposing said hydrogel to cells which are to fonn regenerated tissue, (c) allowing said cells to grow on said hydrogel. [0126] In one embodiment, wherein the method is performed in vivo, in step a), said hydrogel is provided at a place in a body where tissue regeneration is intended, [0000] wherein said step a) is preferably performed by injecting said hydrogel at a place in the body where tissue regeneration is intended. [0127] The objects of the present invention are solved by a method of treatment of a wound and for wound healing, said method comprising the step of applying an effective amount of a hydrogel according to the invention or a pharmaceutical composition according to the invention to a wound. [0129] The objects of the present invention are solved by a bioimaging device comprising a hydrogel according to the invention for in vitro and/or in vivo use, [0000] preferably for oral application, for injection and/or for topical application. [0130] The objects of the present invention are solved by a 2D or 3D cell culture substrate comprising a hydrogel according to the invention. [0131] The peptides, peptidomimetics and peptoids disclosed herein are suitable as ink(s) or (biomaterial) building block(s) in biofabrication, including bioprinting, (bio)moulding. [0132] “Biofabrication” as used herein refers to the use of techniques, such as additive manufacturing (i.e. bio-printing) and moulding to create 2D and 3D structures or biological constructs from biomaterial building blocks (i.e. the peptides and/or peptoids according to the invention). During the fabrication process, bioactive moieties and cells can be incorporated in a precise fashion. In the specific example of “bio-printing”, a computer-aided device is used to precisely deposit the biomaterial building block (ink), using a layer-by-layer approach, into the pre-determined, prescribed 3D geometry. The size of these structures range from the micro-scale to larger structures. Additives such as growth factors, cytokines, vitamins, minerals, oligonucleotides, small molecule drugs, and other bioactive moieties, and various cell types can also be accurately deposited concurrently or subsequently. Bio-inert components can be utilized as supports or fillers to create open inner spaces to mimic biological tissue. Such biological constructs can be subsequently implanted or used to investigate the interactions between cells and/or biomaterials, as well as to develop 3D disease models. In the specific example of “moulding”, the biomaterial building block is deposited into a template of specific shape and dimensions, together with relevant bioactive moieties and cells. [0000] (see Malda J., et al. Engineering Hydrogels for Biofabrication. Adv. Mater. (2013); Murphy S. V., et al. Evaluation of Hydrogels for Bio-printing Applications. J. of Biomed. Mater. Res. (2012)). [0133] “Bioprinting” is part of the field tissue engineering which is the use of a combination of cells, engineering and materials methods, and suitable biochemical and physio-chemical factors to improve or replace biological functions. [0134] Tissue engineering is used to repair or replace portions of or whole tissues (i.e., bone, cartilage, blood vessels, bladder, skin, muscle etc.). Often, the tissues involved require certain mechanical and structural properties for proper functioning. [0135] The term “bioprinting” as used herein also comprises a process of making a tissue analog by depositing scaffolding or ink material (the peptides/peptoids of the invention or hydrogels thereof) alone, or mixed with cells, based on computer driven mimicking of a texture and a structure of a naturally occurring tissue. [0136] An “ink” or “bio-ink” for bioprinting as used herein refers to the biomaterial building block that is sequentially deposited to build a macromolecular scaffold. [0137] In one embodiment, the C-terminal amino acid is further functionalized. [0138] In one embodiment, the polar functional group(s) can be used for chemical conjugation or coupling of at least one compound selected from bioactive molecules or moieties, such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides; label(s), dye(s), such as imaging contrast agents; pathogens, such as viruses, bacteria and parasites; micro- and nanoparticles or combinations thereof wherein said chemical conjugation can be carried out before or after self-assembly of the peptide and/or peptoid. [0147] In one embodiment, the use according to the invention comprises a conformational change of the peptide(s) and/or peptoid(s) during self-assembly, [0000] preferably a conformational change from a random coil conformation to a helical intermediate structure (such as α-helical fibrils) to a final beta turn or cross beta conformation, such as fibrils which further aggregate and/or condense into nanofibers (which make up a network), wherein, preferably, the conformational change is dependent on the peptide concentration, ionic environment, pH and temperature. [0148] In one embodiment, at least one peptide and/or peptoid as herein defined forms a hydrogel. [0149] The hydrogel is formed by self-assembly of the peptide and/or peptiod, as explained in further detail below. [0150] In one embodiment, different peptide(s) and/or peptoid(s) as defined herein are used to form the hydrogel. [0151] Preferably, different peptide(s) and/or peptoid(s) refers to peptide(s) and/or peptoid(s) that differ in their amino acid sequence, C-terminal group(s), conjugated/coupled compounds (such as different labels, bioactive molecules etc) or combinations thereof. [0152] In one embodiment, at least one peptide and/or peptoid as defined herein is dissolved in water and wherein the solution obtained can be dispensed through needles and print heads. [0153] In one embodiment, the use according to the invention comprises conjugation or coupling of further compound(s) to the peptides and/or peptoid, preferably to C-terminal group(s), post-assembly, wherein said further compound(s) can be selected from bioactive molecules or moieties, such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides; label(s), dye(s), such as imaging contrast agents; pathogens, such as viruses, bacteria and parasites; micro- and nanoparticles or combinations thereof. [0163] In one embodiment, the peptide and/or peptoid is present at a concentration in the range of from 0.1% to 30% (w/w), preferably 0.1% to 20% (w/w), more preferably 0.1% to 10% (w/w), more preferably 0.1% to 5% (w/w), even more preferably 0.1% to 3% (w/w), with respect to the total weight of said hydrogel. [0164] In one embodiment, the use according to the invention comprises the addition or mixing of cells prior or during gelation, which are encapsulated by the hydrogel, wherein said cells can be stem cells (mesenchymal, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells and primary cells isolated from patient samples (fibroblasts, nucleus pulposus). preferably comprising the addition of further compound(s) prior or during gelation, which are co-encapsulated by the hydrogel. [0166] In one embodiment, the use according to the invention comprises the addition of cells onto the printed hydrogel, wherein said cells can be stem cells (adult, progenitor, embryonic and induced pluripotent stein cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hematopoietic and cancer cells). [0167] In one embodiment, the use according to the invention comprises [0000] (1) the addition or mixing of cells prior or during gelation, which are encapsulated by the hydrogel, and (2) subsequently comprising the addition of cells onto the printed hydrogel, wherein said cells of (1) and (2) are the same or different, and can be stem cells (adult, progenitor, embryonic and induced pluripotent stein cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hematopoietic and cancer cells). [0168] In one embodiment, the use according to the invention comprises the addition of cross-linkers to the peptide(s) and/or peptoid(s), [0000] wherein said cross-linkers preferably include short linkers, linear and branched polymers, polymers conjugated with bioactive molecules or moieties. [0169] The objects of the present invention are solved by a method of preparing a hydrogel, the method comprising dissolving at least one peptide and/or peptoid as defined herein in an aqueous solution, such as water, or in a polar solvent, such as ethanol. [0170] In one embodiment, the method of the invention comprises stimuli-responsive gelation of the at least one peptide and/or peptoid as defined herein, [0000] wherein said stimulus/stimuli or gelation condition(s) is/are selected from pH, salt concentration and/or temperature. [0171] In one embodiment, the at least one peptide and/or peptoid comprises as the polar head group basic amino acid(s), such as lysine or lysine-mimetic molecules, preferably ainidated basic amino acid(s), [0000] and gelation is carried out in the presence of salt at physiological conditions (such as PBS or 0.9% saline and PBS) and/or at a pH above physiological pH, preferably pH 7 to 10 (such as by adding NaOH). [0172] In one embodiment, the at least one peptide and/or peptoid comprises as the polar head group acidic amino acid(s), [0000] and gelation is carried out at a pH below physiological pH 7, preferably pH 2 to 6. [0173] In one embodiment, the dissolved peptide and/or peptoid is further warmed or heated, wherein the temperature is in the range from 20° C. to 90° C., preferably from about 30° C. to 70° C., more preferably from about 37° C. to 70° C. [0174] In one embodiment, the at least one peptide and/or peptoid is dissolved at a concentration from 0.01 μg/ml to 100 mg/ml, preferably at a concentration from 1 mg/ml to 50 mg/ml, more preferably at a concentration from about 1 mg/ml to about 20 mg/ml. [0175] The objects of the present invention are solved by a method of preparing continuous fibres, the method comprising dissolving at least one peptide and/or peptoid as defined herein in an aqueous solution, such as water, and dispensing the solution obtained through needles, print heads, fine tubings and/or microfluidic devices into a buffered solution, such as PBS. [0178] In one embodiment, the method comprises the addition of further compound(s) prior or during gelation/self-assembly, which are encapsulated by the hydrogel, wherein said further compound(s) can be selected from bioactive molecules or moieties, such as growth factors, cytokines, lipids, cell receptor ligands, hormones, prodrugs, drugs, vitamins, antigens, antibodies, antibody fragments, oligonucleotides (including but not limited to DNA, messenger RNA, short hairpin RNA, small interfering RNA, microRNA, peptide nucleic acids, aptamers), saccharides; label(s), dye(s), such as imaging contrast agents; pathogens, such as viruses, bacteria and parasites; quantum dots, nano- and microparticles, or combinations thereof. [0188] In one embodiment, the method comprises the addition or mixing of cells prior or during gelation/self-assembly, which are encapsulated by the hydrogel, wherein said cells can be stein cells (mesenchymal, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells and primary cells isolated from patient samples (fibroblasts, nucleus pulposus). preferably comprising the addition of further compound(s) prior or during gelation (such as defined herein), which are co-encapsulated by the hydrogel. [0190] In one embodiment, the method comprises the addition of cells onto the printed hydrogel, wherein said cells can be stem cells (adult, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hematopoietic and cancer cells). [0191] In one embodiment, the method comprises the following steps: [0000] (1) the addition or mixing of cells prior or during gelation, which are encapsulated by the hydrogel, and (2) subsequently the addition of cells onto the printed hydrogel, wherein said cells of (1) and (2) are the same or different, and can be stem cells (adult, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hematopoietic and cancer cells). [0192] In one embodiment, the method comprises the addition of cross-linkers to the peptide(s) and/or peptoid(s) prior, during or after gelation/self-assembly, [0000] wherein said cross-linkers preferably include short linkers, linear and branched polymers, polymers conjugated with bioactive molecules or moieties (such as defined herein), wherein, preferably, said cross-linkers interact electrostatically with the peptides and/or peptoid(s) during self-assembly. [0193] In one embodiment, the method comprises the use of different peptide(s) and/or peptoid(s). [0194] Preferably, different peptide(s) and/or peptoid(s) refers to peptide(s) and/or peptoid(s) that differ in their amino acid sequence, C-terminal group(s), conjugated/coupled compounds (such as different labels, bioactive molecules etc) or combinations thereof. [0195] The objects of the present invention are solved by the use of a hydrogel obtained by a method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention for substrate-mediated gene delivery, [0000] wherein oligonucleotides are encapsulated in the hydrogel and cells are co-encapsulated or seeded onto said hydrogel. [0196] The objects of the present invention are solved by the use (of a peptide and/or peptoid for biofabrication) according to the invention or the use of a hydrogel obtained by a method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, for obtaining 2D mini-hydrogel arrays, [0000] preferably comprising using printers, pintools and micro-contact printing. [0197] Preferably, a microarray of the invention comprises hydrogels that encapsulate different biomolecules, drugs, compounds, cells etc. [0198] In one embodiment, said use comprises printing the 2D mini-hydrogels onto electrical circuits or piezoelectric surfaces that conduct current. [0199] The objects of the present invention are solved by the use (of a peptide and/or peptidomimetic for biofabrication) according to the invention or the use of a hydrogel obtained by a method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, as injectable or for injectable therapies, [0000] such as for the treatment of degenerative disc disease. [0200] An injectable is preferably an injectable scaffold or an injectable implant or an implantable scaffold. [0201] By virtue of their self-assembling properties, the stimuli-responsive ultrashort peptides of the present invention are ideal candidates for injectable scaffolds. Such scaffolds can be injected as semi-viscous solutions that complete assembly in situ. Irregular-shaped defects can be fully filled, facilitating scaffold integration with native tissue. These injectable formulations offer significant advantages over ex vivo techniques of preparing nanofibrous scaffolds, such as electrospinning, which have to be surgically implanted. During the process of in situ gelation, the ability to modulate gelation rate enables the clinician to sculpt the hydrogel construct into the desired shape for applications such as dermal fillers. Furthermore, the bio compatibility and in vivo stability bodes well for implants that need to persist for several months. Taking into consideration the stiffness and tunable mechanical properties, we are particularly interested in developing injectable therapies and implantable scaffolds that fulfill mechanically supportive roles. [0202] The objects of the present invention are solved by the use (of a peptide and/or peptoid for biofabrication) according to the invention or the use of a hydrogel obtained by a method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, comprising bioprinting, such as 3D microdroplet printing, and biomoulding. [0203] In one embodiment, said use is for obtaining 3D organoid structures or 3D macromolecular biological constructs. [0204] An organoid structure is a structure resembling an organe. [0205] The term “3D organoid structures” or “3D macromolecular biological constructs” refers to samples in which various cell types are integrated in a 3D scaffold containing various biochemical cues, in a fashion which resembles native tissue. These constructs can potentially be used as implants, disease models and models to study cell-cell and cell-substrate interactions. [0206] In one embodiment, said use comprises the use of moulds (such as of siliconde) to pattern the hydrogels in 3D. [0207] In one embodiment, said use is for obtaining multi-cellular constructs, [0000] which comprise different cells/cell types, which preferably comprise co-encapsulated further compound(s) (such as defined herein) and/or cross-linkers (such as defined herein). [0208] In one embodiment, said use is for obtaining 3D cellular constructs or scaffolds comprising encapsulated cells and cells deposited or printed onto the surface of the printed/fabricated scaffold. [0209] In one embodiment, said use is for preparation of cell based assays, preferably for identifying patient specimens, more preferably for identifying patient specimens containing pathogens (e.g. dengue, malaria, norovirus), which do not infect primary cells that have lost their native phenotype; recovery of infected cells to identify and expand pathogen(s) of interest, preferably for elucidating mechanism(s) of infection and/or enabling the design of molecules that inhibit pathogen infection and/or replication. [0214] The objects of the present invention are solved by a method for obtaining a multi-cellular construct, comprising preparing a hydrogel by the method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, comprising the addition or mixing of different cells or cell types prior or during gelation/self-assembly, which are encapsulated by the hydrogel, wherein said cells can be stem cells (mesenchymal, progenitor, embryonic and induced pluripotent stem cells), transdifferentiated progenitor cells and primary cells isolated from patient samples (fibroblasts, nucleus pulposus). preferably comprising the addition of further compound(s) (such as defined herein) prior or during gelation, which are co-encapsulated by the hydrogel, optionally comprising the addition of cross-linkers (such as defined herein) to the peptide(s) and/or peptoid(s) prior or during gelation/self-assembly, obtaining the multi-cellular construct. [0222] The objects of the present invention are solved by a method for obtaining a multi-cellular construct, comprising preparing a hydrogel by the method (for preparing a hydrogel and/or for preparing continuous fibers) according to the invention, comprising the following steps: (1) the addition or mixing of cells prior or during gelation, which are encapsulated by the hydrogel, and (2) subsequently the addition of cells onto the printed hydrogel, wherein said cells of (1) and (2) are different, and can be stem cells (adult, progenitor, embryonic and induced pluripotent stein cells), transdifferentiated progenitor cells, and primary cells (isolated from patients) and cell lines (such as epithelial, neuronal, hernatopoietic and cancer cells), preferably comprising the addition of further compound(s) (such as defined herein) prior or during gelation, which are co-encapsulated by the hydrogel, optionally comprising the addition of cross-linkers (such as defined herein) to the peptide(s) and/or peptidomimetic(s) prior or during gelation/self-assembly, obtaining the multi-cellular construct. [0232] In one embodiment, the multi-cellular construct obtained is formed in a mould (such as of silicone). [0233] The objects of the present invention are solved by a multi-cellular construct obtained according to the methods for obtaining a multi-cellular construct according to the invention and as described herein above, preferably comprising micro-domains. [0235] The objects of the present invention are solved by the use of a 3D biological construct obtained by a method (for obtaining a 3D biological construct) according to the invention or of a multi-cellular construct obtained according to the method (for obtaining a multi-cellular construct) according to the invention as: organoid model for screening biomolecule libraries, studying cell behavior, infectivity of pathogens and disease progression, screening infected patient samples, evaluating drug efficacy and toxicity, tissue-engineered implant for regenerative medicine, and/or in vitro disease model. [0239] In one embodiment, said use is for preparation of cell based assays, preferably for identifying patient specimens, more preferably for identifying patient specimens containing pathogens (e.g. dengue, malaria, norovirus), which do not infect primary cells that have lost their native phenotype; recovery of infected cells to identify and expand pathogen(s) of interest, preferably for elucidating mechanism(s) of infection and/or enabling the design of molecules that inhibit pathogen infection and/or replication. BRIEF DESCRIPTION OF THE DRAWINGS [0244] Reference is now made to the figures, wherein: [0245] FIG. 1 . Self-assembly of ultrashort peptides/peptidomimetics into macromolecular nanofibrous hydrogels. [0246] (A) These amphiphilic peptides have the characteristic motif, wherein the aliphatic amino acids are arranged in decreasing hydrophobicity from N-terminus. During self-assembly, the peptides are hypothesized to associate in an anti-parallel fashion, giving rise to α-helical intermediate structures detected by circular dichroism. (B) As the peptide concentration increases, conformational changes from random coil (black line) to α-helical intermediates (red line) to β-fibrils (blue line) are observed. The insert better illustrates the latter conformations. This phenomenon is observed for hexamers and trimers, though the transition concentration to β-fibrils is higher for the trimer. The peptide dimers subsequently stack in fibrils that aggregate into nanofibers and sheets, which entrap water to form hydrogels. (C) The nanofibrous architecture, as observed using field emission scanning microscopy, resembles extracellular matrix. The fibers extend into the millimeter range. The nanofibers of hexamers readily condense into sheets, while individual fibers are more easily observed for trimers. The fibers form interconnected three-dimensional scaffolds which are porous. [0247] FIG. 2 . Examples of subclasses of peptides/peptidomimetics that demonstrate stimuli-responsive gelation. (refers to the inventors' parallel application “Self-assembling peptides, peptidomimetics and peptidic conjugates as building blocks for biofabrication and printing”, having the same filing date as the present application) [0248] FIG. 3 . Stimuli-responsive gelation of amidated peptides/peptidomimetics containing primary amine groups. (refers to the inventors' parallel application “Self-assembling peptides, peptidomimetics and peptidic conjugates as building blocks for biofabrication and printing”, having the same filing date as the present application) [0249] (A) A subclass of ultrashort peptides with lysine as the polar residue at the C-terminus, form hydrogels more readily in salt solutions—the minimum gelation concentration is significantly lowered and the gelation kinetics are accelerated. Ac-LIVAGK-NH 2 forms hydrogels at 20 mg/mL in water, 12 mg/mL in saline, 7.5 ing/mL in PBS, and 10 mg/mL in 10 mM NaOH. (B) The rigidity, as represented by the storage modulus (G′), of 20 mg/mL Ac-LIVAGK-NH 2 hydrogels increases by one order of magnitude to 10 kPa when dissolved in normal saline (NaCl) as compared to water at 1 kPa. In phosphate buffered saline (PBS), G′ increases to 40 kPa. The stiffness also increases with peptide concentration. (C) The addition of sodium hydroxide (NaOH) enhances the rigidity of 20 mg/mL Ac-LIVAGK-NH 2 hydrogel from 1 kPa in water to 80 kPa. The rigidity increases with NaOH concentration. (D) Hydrogel droplet arrays of various dimensions can be obtained by mixing equivolumes of peptide solution (such as 10 mg/mL Ac-ILNAGK-NH 2 ) and PBS containing small molecules. Bioactive moieties can also be encapsulated; 1 μL droplets with green food colouring and 488 nm emission quantum dots, 2 μL droplets with red food colouring and 568 nm emission fluorophore conjugated to a secondary antibody, and 5 μL droplets with methylene blue and DAPI. (E) Hydrogel “noodles” are obtained by extruding 5 mg/mL peptide solution through a 27 gauge needle into a concentrated salt bath. [0250] FIG. 4 . Cells can be encapsulated and immobilized within the peptide hydrogels for various applications such as induction of differentiation and screening assays. [0251] (A) Human mesenchymal stem cells encapsulated within 2 μL droplets of 5 mg/mL peptide hydrogels. (Ai) Photograph of mini-hydrogels on a 25 mm cover slip. (Aii) The cells encapsulated visualised using fluorescent microscopy of a single mini-hydrogel, wherein the cells are stained with Phalliodin-FITC (cytoskeleton is stained green) and Dapi (nuclei stained blue). (Aiii) The encapsulated cells adopt an elongated morphology as demonstrated in this 2D projection image at 10× magnification. The cells are located on different focal planes. (Aiv) Higher magnification image (63×) showing the focal adhesions (in red). (B) Human mesenchymal stem cells cultured on hydrogel films also adopt an elongated morphology compared to those cultured on (C) glass cover slips. [0252] FIG. 5 . Oligonucleotides such as DNA, mRNA, siRNA can be encapsulated in the hydrogels for substrate mediated gene delivery. Cells can subsequently be co-encapsulated or seeded onto these hydrogels. [0253] (A) Hydrogels protect the oligonucleotide from nuclease degradation. (B) Hydrogels slowly release the encapsulated DNA over time. (C) Cells cultured on hydrogels encapsulating GFP mRNA express the protein of interest (GFP) after 2 days. [0254] FIG. 6 . 2D mini-hydrogel arrays for various applications. [0255] Such 2D arrays can be generated using existing technology such as printers, pintools and Micro-contact printing. (A) The array could be subject to electrical or magnetic stimuli, such as a electric field or point stimuli. The mini-hydrogels can also be printed onto electrical circuits or piezoelectric surfaces to conduct current. (B) Different small molecules or oligonucleotides can be encapsulated to create a biochemical gradient. (C) Different cells can be encapsulated in different mini-hydrogels and treated with the same drug/bioactive molecule dissolved in the bulk media. Alternatively, different drugs or biochemical cues can be incorporated to alter gene expression of the encapsulated cells. [0256] FIG. 7 . The stability and mechanical properties of mini-hydrogels can also be further enhanced through the addition of cross-linkers, including short linkers, linear and branched polymers. [0257] Such composite polymer-peptide hydrogels are produced by incorporating (A) linear and (B) branched polymers that can interact electrostatically with ultrashort peptides during self-assembly. The resulting hydrogels have better mechanical properties (due to cross-linking and increased elasticity) and (C) offer opportunities to incorporate bioactive functionalities to modulate the immune and physiological response. [0258] FIG. 8 . 3D bio printingor moulding techniques to create biological constructs with distinct, multi-functional micro-niches. [0259] Multi-cellular constructs can also be obtained as the hydrogel can spatially confine different cell types. [0260] FIG. 9 . A novel class of hydrophobic peptides which self-assemble into hydrogels. [0261] (A) These hydrophobic peptides have the characteristic motif, wherein the aliphatic amino acids are arranged in decreasing hydrophobicity from N-terminus, as exemplified by Ac-ILVAG. (B) A hydrogel comprising of peptide Ac-ILVAG (at 5 mg/mL), which has a carboxylic acid as a polar functional group at the C-terminus. [0262] FIG. 10 . C-terminus functionalization of the hydrophobic peptides. [0263] (A) The characteristic peptidic motif that drives self-assembly can be coupled to other functional groups, linkers and small molecules to obtain conjugates that self-assemble. (B) FESEM images of Ac-ILVAG-biotin reveal its nanofibrous architecture, confirming that functionalization at the C-terminus does not disrupt the nanofibrous architecture. DETAILED DESCRIPTION OF THE INVENTION Further Definitions [0264] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. [0265] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described. [0266] The terms “peptoid” and “peptidomimetic” are used herein interchangeably and refer to molecules designed to mimic a peptide. Peptoids or peptidomimetics can arise either from modification of an existing peptide, or by designing similar systems that mimic peptides. These modifications involve changes to the peptide that will not occur naturally (such as altered backbones and/or the incorporation of non-natural amino acids). See above. [0267] The term “amino acid” includes compounds in which the carboxylic acid group is shielded by a protecting group in the form of an ester (including an ortho ester), a silyl ester, an amide, a hydrazide, an oxazole, an 1,3-oxazoline or a 5-oxo-1,3,-oxazolidine. The term “amino acid” also includes compounds in which an amino group of the form —NH 2 or —NHR′ (supra) is shielded by a protecting group. Suitable amino protecting groups include, but are not limited to, a carbamate, an amide, a sulfonamide, an imine, an imide, histidine, a N-2,5,-dimethylpyrrole, an N-1,1,4,4-tetramethyldisilylazacyclopentane adduct, an N-1,1,3,3-tetramethyl-1,3-disilisoindoline, an N-diphenylsilyldiethylene, an 1,3,5-dioxazine, a N-[2-(trimethylsilyl)ethoxy]methylamine, a N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)amine, a N-4,4,4-trifluoro-3-oxo-1-butenylamine, a N-9-borabicyclononane and a nitroamine. A protecting group may also be present that shields both the amino and the carboxylic group such as e.g. in the form of a 2,2-dimethyl-4-alkyl-2-sila-5-oxo-1,3-oxazolidine. The alpha carbon atom of the amino acid typically further carries a hydrogen atom. The so called “side chain” attached to the alpha carbon atom, which is in fact the continuing main chain of the carboxylic acid, is an aliphatic moiety that may be linear or branched. The term “side chain” refers to the presence of the amino acid in a peptide (supra), where a backbone is formed by coupling a plurality of amino acids. An aliphatic moiety bonded to the α carbon atom of an amino acid included in such a peptide then defines a side chain relative to the backbone. As explained above, the same applies to an aliphatic moiety bonded to the amino group of the amino acid, which likewise defines a side chain relative to the backbone of a peptoid. [0268] The term “aliphatic” means, unless otherwise stated, a straight or branched hydrocarbon chain, which may be saturated or mono- or poly-unsaturated and include heteroatoms. The term “heteroatom” as used herein means an atom of any element other than carbon or hydrogen. An unsaturated aliphatic group contains one or more double and/or triple bonds (alkenyl or alkynyl moieties). The branches of the hydrocarbon chain may include linear chains as well as non-aromatic cyclic elements. The hydrocarbon chain, which may, unless otherwise stated, be of any length, and contain any number of branches. Typically, the hydrocarbon (main) chain includes 1 to 5, to 10, to 15 or to 20 carbon atoms. Examples of alkenyl radicals are straight-chain or branched hydrocarbon radicals which contain one or more double bonds. Alkenyl radicals generally contain about two to about twenty carbon atoms and one or more, for instance two, double bonds, such as about two to about ten carbon atoms, and one double bond. Alkynyl radicals normally contain about two to about twenty carbon atoms and one or more, for example two, triple bonds, preferably such as two to ten carbon atoms, and one triple bond. Examples of alkynyl radicals are straight-chain or branched hydrocarbon radicals which contain one or more triple bonds. Examples of alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, the n isomers of these radicals, isopropyl, isobutyl, isopentyl, sec-butyl, tert-butyl, neopentyl, 3,3 dimethylbutyl. Both the main chain as well as the branches may furthermore contain heteroatoms as for instance N, O, S, Se or Si or carbon atoms may be replaced by these heteroatoms. [0269] An aliphatic moiety may be substituted or unsubstituted with one or more functional groups. Substituents may be any functional group, as for example, but not limited to, amino, amido, azido, carbonyl, carboxyl, keto, cyano, isocyano, dithiane, halogen, hydroxyl, nitro, organometal, organoboron, seleno, silyl, silano, sulfonyl, thio, thiocyano, trifluoromethyl sulfonyl, p-toluenesulfonyl, bromobenzenesulfonyl, nitrobenzenesulfonyl, and methanesulfonyl. [0270] As should be apparent from the above, the side chain of an amino acid in a peptide/peptoid described herein may be of a length of 0 to about 5, to about 10, to about 15 or to about 20 carbon atoms. It may be branched and include unsaturated carbon-carbon bonds. In some embodiments one or more natural amino acids are included in the peptide or peptoid. Such a natural amino acid may be one of the 20 building blocks of naturally occurring proteins. [0271] In a peptide or peptoid, including a peptide/peptoid disclosed herein individual amino acids are covalently coupled via amide bonds between a carboxylic group of a first and an amino group of a second amino acid. [0272] The term hydrophobic refers to a compound that is soluble in non-polar fluids. The hydrophobic properties of the peptide and/or peptoid are due to the presence of non-polar moieties within the same peptide and/or peptoid. Besides the hydrophobic peptide sequemce part there is a C-terminal —COOH moiety included that can occur in free, unprotected form, or in protected form. Non-polar moieties of a peptide or peptoid include a hydrocarbon chain that does not carry a functional group. [0273] The non-polar moiety includes an amino acid, generally at least two amino acids, with a hydrocarbon chain that does not carry a functional group. The respective side chain, coupled to the α-carbon atom of the amino acid (supra), may have a main chain that includes 0 to about 20 or 1 to about 20, including 0 to about 15, 1 to about 15, 0 to about 10, 1 to about 10, 1 to about 5 or 0 to about 5 carbon atoms. The non-polar moiety may thus include an amino acid without side chain, i.e. glycine. The peptide and/or peptoid side chain may be branched (supra) and include one or more double or triple bonds (supra). Examples of peptide and/or peptoid side chains include, but are not limited to, methyl, ethyl, propyl, isopropyl, propenyl, propinyl, butyl, butenyl, sec-butyl, tert-butyl, isobutyl, pentyl, neopentyl, isopentyl, pentenyl, hexyl, 3,3 dimethylbutyl, heptyl, octyl, nonyl or decyl groups. As a few illustrative examples, the non-polar moiety may include an amino acid of alanine, valine, leucine, isoleucine, norleucine, norvaline, 2-(methylamino)-isobutyric acid, 2-amino-5-hexynoic acid. Such an amino acid may be present in any desired configuration. Bonded to the non-polar moiety may also be the C-terminus or the N-terminus of the peptide/peptoid. Typically the C-terminus or the N-terminus is in such a case shielded by a protecting group (supra). [0274] In some embodiments the non-polar moiety includes a sequence of amino acids that is arranged in decreasing or increasing size. Hence, a portion of the amino acids of the non-polar moiety may be arranged in a general sequence of decreasing or increasing size. Relative to the direction from N- to C-terminus or from C- to N-terminus this general sequence can thus be taken to be of decreasing size. By the term “general sequence” of decreasing or increasing size is meant that embodiments are included in which adjacent amino acids are of about the same size as long as there is a general decrease or increase in size. Within a general sequence of decreasing size the size of adjacent amino acids of the non-polar moiety is accordingly identical or smaller in the direction of the general sequence of decreasing size. In some embodiments the general sequence of decreasing or increasing size is a non-repetitive sequence. [0275] As an illustrative example, where a respective portion of amino acids is a sequence of five amino acids, the first amino acid may have a 3,4-dimethyl-hexyl side chain. The second amino acid may have a neopentyl side chain. The third amino acid may have a pentyl side chain. The fourth amino acid may have a butyl side chain. The fifth amino acid may be glycine, i.e. have no side chain. Although a neopentyl and a pentyl side chain are of the same size, the general sequence of such a non-polar peptide portion is decreasing in size. As a further illustrative example of a general sequence of decreasing size in a non-polar moiety the respective non-polar portion may be a sequence of three amino acids. The first amino acid may have an n-nonyl side chain. The second amino acid may have a 3-ethyl-2-methyl-pentyl side chain. The third amino acid may have a tert-butyl side chain. As yet a further illustrative example of a general sequence of decreasing size in a non-polar moiety, the non-polar moiety may be a sequence of nine amino acids. The first amino acid may have a 4-propyl-nonyl side chain. The second amino acid may have an n-dodecyl side chain. The third amino acid may have a 6,6-diethyl-3-octenyl side chain. An n-dodecyl side chain and a 6,6-diethyl-3-octenyl side chain both have 12 carbon atoms and thus again have a comparable size, Nevertheless, the 6,6-diethyl-3-octenyl group includes an unsaturated carbon-carbon bond and is thus of slightly smaller size than the dodecyl group. The fourth amino acid may have a 2-methyl-nonyl side chain. The fifth amino acid may have a 3-propyl-hexyl side chain. The sixth amino acid may have an n-hexyl side chain. The seventh amino acid may have a 2-butynyl side chain. The 8th amino acid may have an isopropyl side chain. The ninth amino acid may have a methyl side chain. [0276] Where a portion of the amino acids of the non-polar moiety arranged in a general sequence of decreasing (or increasing) size only contains naturally occurring amino acids (whether in the D- or the L-form), it may for example have a length of five amino acids, such as the sequence leucine-isoleucine-valine-alanine-glycine or isoleucine-leucine-valine-alanine-glycine, A general sequence of decreasing size of only natural amino acids may also have a length of four amino acids. Illustrative examples include the sequences isoleucine-leucine-valine-alanine, leucine-isoleucine-valine-alanine, isoleucine-valine-alanine-glycine, leucine-valine-alanine-glycine, leucine-isoleucine-alanine-glycine, leucine-isoleucine-valine-glycine, isoleucine-leucine-alanine-glycine or isoleucine-leucine-valine-glycine. A general sequence of decreasing size of only natural amino acids may also have a length of three amino acids. Illustrative examples include the sequences isoleucine-valine-alanine, leucine-valine-alanine, isoleucine-valine-glycine, leucine-valine-glycine, leucine-alanine-glycine, isoleucine-alanine-glycine or isoleucine-leucine-alanine. A general sequence of decreasing size of only natural amino acids may also have a length of two amino acids. Illustrative examples include the sequences isoleucine-valine, leucine-valine, isoleucine-alanine, leucine-alanine, leucine-glycine, isoleucine-glycine, valine-alanine, valine-glycine or alanine-glycine. [0277] In some embodiments the direction of decreasing size of the above defined general sequence of decreasing size is the direction toward the C-terminus of the hydrophobic linear sequence. Accordingly, in such embodiments the size of adjacent amino acids within this portion of the non-polar moiety is accordingly identical or smaller in the direction of the C-terminus. Hence, as a general trend in such an embodiment, the closer to the polar moiety of the amphiphilic linear sequence, the smaller is the overall size of a peptide and/or peptoid side chain throughout the respective general sequence of decreasing size. [0278] In some embodiments the entire non-polar moiety of the hydrophobic linear peptide and/or peptoid or the hydrophobic linear sequence, respectively, consists of the general sequence of decreasing (or increasing) size. In such an embodiment the general sequence of decreasing (or increasing) size may have a length of n−m amino acids (cf. above). In some embodiments the general sequence of decreasing or increasing size is flanked by further non-polar side chains of the peptide/peptoid. In one embodiment the general sequence of decreasing (or increasing) size has a length of n−m−1 amino acids. In this embodiment there is one further amino acid included in the peptide/peptoid, providing a non-polar peptide/peptoid side chain. This amino acid may be positioned between the general sequence of decreasing (or increasing) size and the C-terminus, the C-terminus may be positioned between this additional non-polar amino acid and the general sequence of decreasing (or increasing) size or the general sequence of decreasing (or increasing) size may be positioned between the C-terminus and this additional non-polar amino acid. Typically the general sequence of decreasing (or increasing) size is positioned between the C-terminus and this additional non-polar amino acid. The additional non-polar amino acid may for example define the N-terminus of the peptide/peptoid, which may be shielded by a protecting group such as an amide, e.g. a propionic acyl or an acetyl group. Together with the general sequence of decreasing (or increasing) size as defined above it may define the non-polar portion of the peptide/peptoid. The polar amino acid may define the C-terminus of the peptide/peptoid. In this example the general sequence of decreasing (or increasing) size is thus flanked by the polar amino acid on one side and by the additional non-polar amino acid on the other side. In one embodiment where embodiment the general sequence of decreasing (or increasing) size has a length of n−m−1 amino acids, the remaining non-polar amino acid of the non-polar moiety of n−m amino acids is one of alanine and glycine. [0279] As explained above, the polar moiety of the linear sequence may in some embodiments be defined by two or three consecutive amino acids. The polar moiety includes in aliphatic amino acids. Each of the in aliphatic amino acids is independently selected and carries an independently selected polar group. The symbol in represents an integer selected from 1, 2 and 3. The at least essentially non-polar moiety (supra) accordingly has a number of n−m, i.e. n−1, n−2 or n−3 amino acids. In some embodiments n is equal to or larger than m+2. In such an embodiment m may thus represent a number of n−2 or smaller. [0280] In an embodiment where the entire non-polar moiety of the linear peptide and/or peptoid consists of the general sequence of decreasing (or increasing) size (supra), this non-polar moiety may thus have a length of n−2 or n−3 amino acids. In an embodiment where the linear peptide and/or peptoid has a further non-polar side chain in addition to the non-polar moiety of decreasing (or increasing) size, this additional non-polar side chain may be included in an amino acid that is directly bonded to an amino acid of the general sequence of decreasing (or increasing) size. The non-polar moiety may thus be defined by the non-polar moiety of decreasing (or increasing) size and the respective further amino acid with a non-polar side chain. In one such an embodiment where m=1, the non-polar moiety may thus have a length of n−2 amino acids, of which the non-polar moiety of decreasing (or increasing) size has a length of n−3 amino acids. The general sequence of decreasing (or increasing) size may be positioned between the two polar amino acids and this additional non-polar amino acid, or the additional non-polar amino acid may be positioned between the general sequence of decreasing (or increasing) size and the two polar amino acids. Typically the general sequence of decreasing (or increasing) size is positioned between the two polar amino acids and this additional non-polar amino acid. As mentioned above, one of the two polar amino acids may define the C-terminus of the peptide/peptoid. In this example the general sequence of decreasing (or increasing) size may thus be flanked by the two consecutive polar amino acids on one side and by the additional non-polar amino acid on the other side. Again, in some embodiments where m=1 the two consecutive polar amino acids may also be positioned between the general sequence of decreasing (or increasing) size and the additional non-polar amino acid, in which case the non-polar moiety has a first portion with a length of n−3 amino acids and a further portion of one amino acid. [0281] Electrostatic forces, hydrogen bonding and van der Waals forces between hydrophobic linear sequences as defined above, including hydrophobic linear peptides and/or peptoids, result in these hydrophobic linear sequences to be coupled to each other. Without being bound by theory, thereby a cross-linking effect occurs that allows the formation of a hydrogel. In this regard the inventors have observed the formation of fibers based on helical structures. [0282] The fibers formed of hydrophobic linear sequences of hydrophobic peptides and/or peptoids disclosed herein typically show high mechanical strength, which renders them particularly useful in tissue regeneration applications, for instance the replacement of damaged tissue. Hydrophobic peptides and/or peptoids disclosed herein have been observed to generally assemble into a fiber structure that resembles collagen fibers. Collagen, a component of soft tissue in the animal and human body, is a fibrous protein that provides most of the tensile strength of tissue. The mechanical strength of fibers of hydrophobic peptides and/or peptoids disclosed herein has been found to typically be much higher than that of collagen (cf. e.g. Figures) of gelatine, the hydrolysed form of collagen. An hydrophobic peptide and/or peptoid disclosed herein may thus be included in a hydrogel that is used as permanent or temporary prosthetic replacement for damaged or diseased tissue. [0283] The hydrophobic linear sequence of the peptide/peptoid, which may represent the entire hydrophobic peptide/peptoid (supra) has been found to show remarkable stability at physiological conditions, even at elevated temperatures. It is in some embodiments stable in aqueous solution at physiological conditions at ambient temperature for a period of time in the range from 1 day to 1 month or more. It may in some embodiments be stable in aqueous solution at physiological conditions at 90° C. for at least 1 hour, at least 2 hours, at least 3 hours, at least 4 hours or at least 5 hours An hydrophobic linear sequence of an hydrophobic peptide and/or peptoid including an hydrophobic linear peptide and/or peptoid, is capable of providing a self assembling α-helical fiber in aqueous solution under physiological conditions. The peptides/peptoids (typically 3-7-mers) in the L- or D-form can self assemble into supramolecular helical fibers which are organized into mesh-like structures mimicking biological substances such as collagen. It has previously been observed in X-ray crystallography that peptides of a length of 3 to 6 amino acids with repetitive alanine containing sequences and an acetylated C-terminus take a helical conformation (Hatakeyama, Y, et al, Angew. Chem. Int. Ed. (2009) 8695-8698). Using peptides with an hydrophobic sequence, Ac-LD 6 (L), the formation of aggregates has for example been observed already at 0.1 mg/ml. As the concentration of peptide is increased to 1 mg/ml, the peptide monomers were found to align to form fibrous structures. With a formation of fibers occurring under physiological conditions at concentrations below 2 mM a peptide/peptoid is well suited as an injectable hydrogel material that can form a hydrogel under physiological conditions. Also disclosed herein is an hydrophobic linear peptide and/or peptoid as defined above for tissue engineering as well as to a tissue engineering method that involves applying, including injecting a respective hydrophobic linear peptide and/or peptoid. [0284] A hydrogel is typically characterized by a remarkable rigidity and are generally biocompatible and non-toxic. Depending on the selected peptide/peptoid sequence these hydrogels can show thermoresponsive or thixotropic character. Reliant on the peptide/peptoid assembling conditions the fibers differ in thickness and length. Generally rigid hydrogels are obtained that are well suited for cultivation of a variety of primary human cells, providing peptide/peptoid scaffolds that can be useful in the repair and replacement of various tissues. Disclosed is also a process of preparing these hydrogels. The exemplary usage of these hydrogels in applications such as cell culture, tissue engineering, plastic surgery, drug delivery, oral applications, cosmetics, packaging and the like is described, as well as for technical applications, as for example for use in electronic devices which might include solar or fuel cells. [0285] As an hydrophobic linear sequence of the peptide/peptoid, a hydrogel shows high stability at physiological conditions, even at elevated temperatures. In some embodiments such a hydrogel is stable in aqueous solution at ambient temperature for a period of at least 7 days, at least 14 days, at least a month or more, such as at least 1 to about 6 months. [0286] In some embodiments a hydrogel disclosed herein is coupled to a molecule or a particle, including a quantum dot, with characteristic spectral or fluorometric properties, such as a marker, including a fluorescent dye. A respective molecule may for instance allow monitoring the fate, position and/or the integrity of the hydrogel. [0287] In some embodiments a hydrogel disclosed herein is coupled to a molecule with binding affinity for a selected target molecule, such as a microorganism, a virus particle, a peptide, a peptoid, a protein, a nucleic acid, a peptide, an oligosaccharide, a polysaccharide, an inorganic molecule, a synthetic polymer, a small organic molecule or a drug. [0288] The term “nucleic acid molecule” as used herein refers to any nucleic acid in any possible configuration, such as single stranded, double stranded or a combination thereof. Nucleic acids include for instance DNA molecules (e.g., cDNA or genomic DNA), RNA molecules (e.g., mRNA), analogues of the DNA or RNA generated using nucleotide analogues or using nucleic acid chemistry, locked nucleic acid molecules (LNA), and protein nucleic acids molecules (PNA). DNA or RNA may be of genomic or synthetic origin and may be single or double stranded. In the present method of an embodiment of the invention typically, but not necessarily, an RNA or a DNA molecule will be used. Such nucleic acid can be e.g. mRNA, cRNA, synthetic RNA, genomic DNA, cDNA synthetic DNA, a copolymer of DNA and RNA, oligonucleotides, etc. A respective nucleic acid may furthermore contain non-natural nucleotide analogues and/or be linked to an affinity tag or a label. In some embodiments the nucleic acid molecule may be isolated, enriched, or purified. The nucleic acid molecule may for instance be isolated from a natural source by cDNA cloning or by subtractive hybridization. The natural source may be mammalian, such as human, blood, semen, or tissue. The nucleic acid may also be synthesized, e.g. by the triester method or by using an automated DNA synthesizer. [0289] Many nucleotide analogues are known and can be used in nucleic acids and oligonucleotides used in the methods of exemplary embodiments of the invention. A nucleotide analogue is a nucleotide containing a modification at for instance the base, sugar, or phosphate moieties. Modifications at the base moiety include natural and synthetic modifications of A, C, G, and T/U, different purine or pyrimidine bases, such as uracil-5-yl, hypoxanthin-9-yl, and 2-aminoadenin-9-yl, as well as non-purine or non-pyrimidine nucleotide bases. Other nucleotide analogues serve as universal bases. Universal bases include 3-nitropyrrole and 5-nitroindole. Universal bases are able to form a base pair with any other base. Base modifications often can be combined with for example a sugar modification, such as for instance 2′-O-methoxyethyl, e.g. to achieve unique properties such as increased duplex stability. [0290] A peptide may be of synthetic origin or isolated from a natural source by methods well-known in the art. The natural source may be mammalian, such as human, blood, semen, or tissue. A peptide, including a polypeptide may for instance be synthesized using an automated polypeptide synthesizer. Illustrative examples of polypeptides are an antibody, a fragment thereof and a proteinaceous binding molecule with antibody-like functions. Examples of (recombinant) antibody fragments are Fab fragments, Fv fragments, single-chain Fv fragments (scFv), diabodies, triabodies (Iliades, P., et al., FEBS Lett (1997) 409, 437-441), decabodies (Stone, E., et al., Journal of Immunological Methods (2007) 318, 88-94) and other domain antibodies (Holt, L. J., et al., Trends Biotechnol. (2003), 21, 11, 484-490). An example of a proteinaceous binding molecule with antibody-like functions is a mutein based on a polypeptide of the lipocalin family (WO 03/029462, Beste et al., Proc. Natl. Acad. Sci. U.S.A. (1999) 96, 1898-1903). Lipocalins, such as the bilin binding protein, the human neutrophil gelatinase-associated lipocalin, human Apolipoprotein D or glycodelin, posses natural ligand-binding sites that can be modified so that they bind to selected small protein regions known as haptens. Examples of other proteinaceous binding molecules are the so-called glubodies (see e.g. internation patent application WO 96/23879), proteins based on the ankyrin scaffold (Mosavi, L. K., et al., Protein Science (2004) 13, 6, 1435-1448) or crystalline scaffold (e.g. internation patent application WO 01/04144) the proteins described in Skerra, J. Mol. Recognit. (2000) 13, 167-187, AdNectins, tetranectins and avimers. Avimers contain so called A-domains that occur as strings of multiple domains in several cell surface receptors (Silverman, J., et al., Nature Biotechnology (2005) 23, 1556-1561). Adnectins, derived from a domain of human fibronectin, contain three loops that can be engineered for immunoglobulin-like binding to targets (Gill, D. S. & Damle, N. K., Current Opinion in Biotechnology (2006) 17, 653-658). Tetranectins, derived from the respective human homotrimeric protein, likewise contain loop regions in a C-type lectin domain that can be engineered for desired binding (ibid.). Where desired, a modifying agent may be used that further increases the affinity of the respective moiety for any or a certain form, class etc. of target matter. [0291] An example of a nucleic acid molecule with antibody-like functions is an aptamer. An aptamer folds into a defined three-dimensional motif and shows high affinity for a given target structure. Using standard techniques of the art such as solid-phase synthesis an aptamer with affinity to a certain target can accordingly be formed and immobilized on a hollow particle of an embodiment of the invention. [0292] As a further illustrative example, a linking moiety such as an affinity tag may be used to immobilise the respective molecule. Such a linking moiety may be a molecule, e.g. a hydrocarbon-based (including polymeric) molecule that includes nitrogen-, phosphorus-, sulphur-, carben-, halogen- or pseudohalogen groups, or a portion thereof. As an illustrative example, the peptide/peptoid included in the hydrogel may include functional groups, for instance on a side chain of the peptide/peptoid, that allow for the covalent attachment of a biomolecule, for example a molecule such as a protein, a nucleic acid molecule, a polysaccharide or any combination thereof. A respective functional group may be provided in shielded form, protected by a protecting group that can be released under desired conditions. Examples of a respective functional group include, but are not limited to, an amino group, an aldehyde group, a thiol group, a carboxy group, an ester, an anhydride, a sulphonate, a sulphonate ester, an imido ester, a silyl halide, an epoxide, an aziridine, a phosphoramidite and a diazoalkane. [0293] Examples of an affinity tag include, but are not limited to, biotin, dinitrophenol or digoxigenin, oligohistidine, polyhistidine, an immunoglobulin domain, maltose-binding protein, glutathione-S-transferase (GST), calmodulin binding peptide (CBP), FLAG′-peptide, the T7 epitope (Ala-Ser-Met-Thr-Gly-Gly-Gln-Gln-Met-Gly), maltose binding protein (MBP), the HSV epitope of the sequence Gln-Pro-Glu-Leu-Ala-Pro-Glu-Asp-Pro-Glu-Asp of herpes simplex virus glycoprotein D, the hemagglutinin (HA) epitope of the sequence Tyr-Pro-Tyr-Asp-Val-Pro-Asp-Tyr-Ala, the “myc” epitope of the transcription factor c-myc of the sequence Glu-Gln-Lys-Leu-Ile-Ser-Glu-Glu-Asp-Leu, or an oligonucleotide tag. Such an oligonucleotide tag may for instance be used to hybridise to an immobilised oligonucleotide with a complementary sequence. A further example of a linking moiety is an antibody, a fragment thereof or a proteinaceous binding molecule with antibody-like functions (see also above). [0294] A further example of linking moiety is a cucurbituril or a moiety capable of forming a complex with a cucurbituril. A cucurbituril is a macrocyclic compound that includes glycoluril units, typically self-assembled from an acid catalyzed condensation reaction of glycoluril and formaldehyde. A cucurbit[n]uril, (CB[n]), that includes n glycoluril units, typically has two portals with polar ureido carbonyl groups. Via these ureido carbonyl groups cucurbiturils can bind ions and molecules of interest. As an illustrative example cucurbit[7]uril (CB[7]) can form a strong complex with ferrocenemethylammonium or adatnantylarnmonium ions. Either the cucurbit[7]uril or e.g. ferrocenemethylammonium may be attached to a biomolecule, while the remaining binding partner (e.g. ferrocenemethylammonium or cucurbit[7]uril respectively) can be bound to a selected surface. Contacting the biomolecule with the surface will then lead to an immobilisation of the biomolecule. Functionalised CB[7] units bound to a gold surface via alkanethiolates have for instance been shown to cause an immobilisation of a protein carrying a ferrocenemethylammonium unit (Hwang, I., et al., J. Am. Chem. Soc. (2007) 129, 4170-4171). [0295] Further examples of a linking moiety include, but are not limited to an oligosaccharide, an oligopeptide, biotin, dinitrophenol, digoxigenin and a metal chelator (cf. also below). As an illustrative example, a respective metal chelator, such as ethylenediamine, ethylenediamine-tetraacetic acid (EDTA), ethylene glycol tetraacetic acid (EGTA), diethylenetriaminepentaacetic acid (DTPA), N,N-bis(carboxymethyl)glycine (also called nitrilotriacetic acid, NTA), 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), 2,3-dimercapto-1-propanol (dimercaprol), porphine or heme may be used in cases where the target molecule is a metal ion. As an example, EDTA forms a complex with most monovalent, divalent, trivalent and tetravalent metal ions, such as e.g. silver (Ag + ), calcium (Ca 2+ ), manganese (Mn 2+ ), copper (Cu 2+ ), iron (Fe 2+ ), cobalt (Co 3+ ) and zirconium (Zr 4+ ), while BAPTA is specific for Ca 2+ . In some embodiments a respective metal chelator in a complex with a respective metal ion or metal ions defines the linking moiety. Such a complex is for example a receptor molecule for a peptide of a defined sequence, which may also be included in a protein. As an illustrative example, a standard method used in the art is the formation of a complex between an oligohistidine tag and copper (Cu 2+ ), nickel (Ni 2+ ), cobalt (Co 2+ ), or zink (Zn 2+ ) ions, which are presented by means of the chelator nitrilotriacetic acid (NTA). [0296] Avidin or streptavidin may for instance be employed to immobilise a biotinylated nucleic acid, or a biotin containing monolayer of gold may be employed (Shumaker-Parry, J. S., et al., Anal. Chem. (2004) 76, 918). As yet another illustrative example, the biomolecule may be locally deposited, e.g. by scanning electrochemical microscopy, for instance via pyrrole-oligonucleotide patterns (e.g. Fortin, E., et al., Electroanalysis (2005) 17, 495). In other embodiments, in particular where the biomolecule is a nucleic acid, the biomolecule may be directly synthesised on the surface of the immobilisation unit, for example using photoactivation and deactivation. As an illustrative example, the synthesis of nucleic acids or oligonucleotides on selected surface areas (so called “solid phase” synthesis) may be carried out using electrochemical reactions using electrodes. An electrochemical deblocking step as described by Egeland & Southern (Nucleic Acids Research (2005) 33, 14, e125) may for instance be employed for this purpose. A suitable electrochemical synthesis has also been disclosed in US patent application US 2006/0275927. In some embodiments light-directed synthesis of a biomolecule, in particular of a nucleic acid molecule, including UV-linking or light dependent 5′-deprotection, may be carried out. [0297] The molecule that has a binding affinity for a selected target molecule may be immobilised on the nanocrystals by any means. As an illustrative example, an oligo- or polypeptide, including a respective moiety, may be covalently linked to the surface of nanocrystals via a thio-ether-bond, for example by using ω functionalized thiols. Any suitable molecule that is capable of linking a nanocrystal of an embodiment of the invention to a molecule having a selected binding affinity may be used to immobilise the same on a nanocrystal. For instance a (bifunctional) linking agent such as ethyl-3-dimethylaminocarbodiimide, N-(3-aminopropyl) 3-mercapto-benzamide, 3-aminopropyl-trimethoxysilane, 3-mercaptopropyl-trimethoxysilane, 3-(trimethoxysilyl) propyl-maleimide, or 3-(trimethoxysilyl) propyl-hydrazide may be used. Prior to reaction with the linking agent, the surface of the nanocrystals can be modified, for example by treatment with glacial mercaptoacetic acid, in order to generate free mercaptoacetic groups which can then employed for covalently coupling with an analyte binding partner via linking agents. [0298] Embodiments of the present invention also include a hydrogel, which can be taken to be a water-swollen water-insoluble polymeric material. The hydrogel includes, including contains and consists of a peptide and/or peptoid as defined above. Since a hydrogel maintains a three-dimensional structure, a hydrogel of an embodiment of the invention may be used for a variety of applications. Since the hydrogel has a high water content and includes amino acids, it is typically of excellent biocompatibility. [0299] A hydrogel according to an embodiment of the invention is formed by self-assembly. The inventors have observed that the peptides/peptoids assemble into fibers that form mesh-like structures. Without being bound by theory hydrophobic interaction between non-polar portions of peptides/peptoids are contemplated to assist such self-assembly process. [0300] The method of forming the hydrogel includes dissolving the peptide/peptoid in aqueous solution. Agitation, including mixing such as stirring, and/or sonication may be employed to facilitate dissolving the peptide/peptoid. In some embodiments the aqueous solution with the peptide/peptoid therein is exposed to a temperature below ambient temperature, such as a temperature selected from about 2° C. to about 15° C. In some embodiments the aqueous solution with the peptide/peptoid therein is exposed to an elevated temperature, i.e. a temperature above ambient temperature. Typically the aqueous solution is allowed to attain the temperature to which it is exposed. The aqueous solution may for example be exposed to a temperature from about 25° C. to about 85° C. or higher, such as from about 25° C. to about 75° C., from about 25° C. to about 70° C., from about 30° C. to about 70° C., from about 35° C. to about 70° C., from about 25° C. to about 60° C., from about 30° C. to about 60° C., from about 25° C. to about 50° C., from about 30° C. to about 50° C. or from about 40° C. to about 65° C., such as e.g. a temperature of about 40° C., about 45° C., about 50° C., about 55° C., about 60° C. or about 65° C. The aqueous solution with the peptide/peptoid therein may be maintained at this temperature for a period of about 5 min to about 10 hours or more, such as about 10 min to about 6 hours, about 10 min to about 4 hours, about 10 min to about 2.5 hours, about 5 min to about 2.5 hours, about 10 min to about 1.5 hours or about 10 min to about 1 hour, such as about 15 min, about 20 min, about 25 min, about 30 min, about 35 min or about 40 min. [0301] In some embodiments a hydrogel disclosed herein is a biocompatible, including a pharmaceutically acceptable hydrogel. The term “biocompatible” (which also can be referred to as “tissue compatible”), as used herein, is a hydrogel that produces little if any adverse biological response when used in vivo. The term thus generally refers to the inability of a hydrogel to promote a measurably adverse biological response in a cell, including in the body of an animal, including a human. A biocompatible hydrogel can have one or more of the following properties: non-toxic, non-mutagenic, non-allergenic, non-carcinogenic, and/or non-irritating. A biocompatible hydrogel, in the least, can be innocuous and tolerated by the respective cell and/or body. A biocompatible hydrogel, by itself, may also improve one or more functions in the body. [0302] Depending on the amino acids that are included in the peptide/peptoid that is included in a hydrogel, a respective hydrogel may be biodegradable. A biodegradable hydrogel gradually disintegrates or is absorbed in vivo over a period of time, e.g., within months or years. Disintegration may for instance occur via hydrolysis, may be catalysed by an enzyme and may be assisted by conditions to which the hydrogel is exposed in a human or animal body, including a tissue, a blood vessel or a cell thereof. Where a peptide is made up entirely of natural amino acids, a respective peptide can usually be degraded by enzymes of the human/animal body. [0303] A hydrogel according to an embodiment of the invention may also serve as a depot for a pharmaceutically active compound such as a drug. A hydrogel according to an embodiment of the invention may be designed to mimic the natural extracellular matrix of an organism such as the human or animal body. A fiber formed from the peptide/peptoid of an embodiment of the invention, including a respective hydrogel, may serve as a biological scaffold. A hydrogel of an embodiment of the invention may be included in an implant, in a contact lens or may be used in tissue engineering. In one embodiment, the peptides consist typically of 3-7 amino acids and are able to self-assemble into complex fibrous scaffolds which are seen as hydrogels, when dissolved in water or aqueous solution. These hydrogels can retain water up to 99.9% and possess sufficiently high mechanical strength. Thus, these hydrogels can act as artificial substitutes for a variety of natural tissues without the risk of immunogenicity. The hydrogels in accordance with the present invention may be used for cultivating suitable primary cells and thus establish an injectable cell-matrix compound in order to implant or reimplant the newly formed cell-matrix in vivo. Therefore, the hydrogels in accordance with the present invention are particularly useful for tissue regeneration or tissue engineering applications. As used herein, a reference to an “implant” or “implantation” refers to uses and applications of/for surgical or arthroscopic implantation of a hydrogel containing device into a human or animal, e.g. mammalian, body or limb. Arthroscopic techniques are taken herein as a subset of surgical techniques, and any reference to surgery, surgical, etc., includes arthroscopic techniques, methods and devices. A surgical implant that includes a hydrogel according to an embodiment of the invention may include a peptide and/or peptoid scaffold. This the peptide and/or peptoid scaffold may be defined by the respective hydrogel. A hydrogel of an embodiment of the invention may also be included in a wound cover such as gauze or a sheet, serving in maintaining the wound in a moist state to promote healing. [0304] Depending on the amino acid sequence used in the peptide/peptoid the hydrogel may be temperature-sensitive. It may for instance have a lower critical solution temperature or a temperature range corresponding to such lower critical solution temperature, beyond which the gel collapses as hydrogen bonds by water molecules are released as water molecules are released from the gel. [0305] The disclosed subject matter also provides improved chiral hydrophobic natural-based peptides and/or peptoids that assemble to peptide/peptoid hydrogels with very favorable material properties. The advantage of these peptide/peptoid hydrogels is that they are accepted by a variety of different primary human cells, thus providing peptide scaffolds that can be useful in the repair and replacement of various tissues. Depending on the chirality of the peptide monomer the character of the hydrogels can be designed to be more stable and less prone to degradation though still biocompatible. [0306] A hydrogel and/or a peptide/peptoid described herein can be administered to an organism, including a human patient per se, or in pharmaceutical compositions where it may include or be mixed with pharmaceutically active ingredients or suitable carriers or excipient(s). Techniques for formulation and administration of respective hydrogels or peptides/peptoids resemble or are identical to those of low molecular weight compounds well established in the art. Exemplary routes include, but are not limited to, oral, transdermal, and parenteral delivery. A hydrogel or a peptide/peptoid may be used to fill a capsule or tube, or may be provided in compressed form as a pellet. The peptide/peptoid or the hydrogel may also be used in injectable or sprayable form, for instance as a suspension of a respective peptide/peptoid. [0307] A hydrogel of an embodiment of the invention may for instance be applied onto the skin or onto a wound. Further suitable routes of administration may, for example, include depot, oral, rectal, transmucosal, or intestinal administration; parenteral delivery, including intramuscular, subcutaneous, intravenous, intramedullary injections, as well as intrathecal, direct intraventricular, intraperitoneal, intranasal, or intraocular injections. It is noted in this regard that for administering microparticles a surgical procedure is not required. Where the microparticles include a biodegradable polymer there is no need for device removal after release of the anti-cancer agent. Nevertheless the microparticles may be included in or on a scaffold, a coating, a patch, composite material, a gel or a plaster. [0308] In some embodiments one may administer a hydrogel and/or a peptide/peptoid in a local rather than systemic manner, for example, via injection. [0309] Pharmaceutical compositions that include a hydrogel and/or a peptide/peptoid of an embodiment of the present invention may be manufactured in a manner that is itself known, e. g., by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or lyophilizing processes. [0310] Pharmaceutical compositions for use in accordance with an embodiment of the present invention thus may be formulated in conventional manner using one or more physiologically acceptable carriers including excipients and auxiliaries that facilitate processing of the hydrogel and/or peptide/peptoid into preparations that can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen. [0311] For injection, the peptide/peptoid of an embodiment of the invention may be formulated in aqueous solutions, for instance in physiologically compatible buffers such as Hanks's solution, Ringer's solution, or physiological saline buffer. For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art. [0312] For oral administration, the hydrogel and/or peptide/peptoid can be formulated readily by combining them with pharmaceutically acceptable carriers well known in the art. Such carriers enable the hydrogel and/or peptide/peptoid, as well as a pharmaceutically active compound, to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a patient to be treated. Pharmaceutical preparations for oral use can be obtained by adding a solid excipient, optionally grinding a resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatine, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be added, such as the cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate. [0313] Dragee cores are provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterize different combinations of active compound doses. [0314] Pharmaceutical preparations that can be used orally include push-fit capsules made of gelatine, as well as soft, sealed capsules made of gelatine and a plasticizer, such as glycerol or sorbitol. The push-fit capsules can contain the active ingredients in admixture with filler such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the peptides/peptoids may be suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. All formulations for oral administration should be in dosages suitable for such administration. For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner. [0315] The hydrogel and/or peptide/peptoid may be formulated for parenteral administration by injection, e.g., by intramuscular injections or bolus injection or continuous infusion. Formulations for injection may be presented in unit dosage form, e. g., in ampules or in multi-dose containers, with an added preservative. The respective compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents. [0316] The hydrogel and/or peptide/peptoid may be formulated for other drug delivery systems like implants, or trandermal patches or stents. [0317] The present invention provides a novel class of hydrogel-forming hydrophobic peptides/peptidomimetics. [0318] The inventors have found advantages and properties that the absence of a polar head group, such as hydrophilic amino acid(s), is giving to small peptides consisting solely of hydrophobic amino acids. [0319] The absence of a polar group at the C-terminus gives rise to a new class of self-assembling peptides with different properties to the so far disclosed class of ultrashort peptides. It is not evident for a person aware of the state-of-the-art that a solely hydrophobic sequence of amino acids will be able to self-assemble to fibrous scaffolds, ending up in hydrogels. The so far explored assembly process of the currently explored type of ultrashort peptides was thought to be solely depending on amphiphilic sequences. The absence of a polar head group would have been more likely predicted to generate micelle-like structures, but not soft solid material. In addition, the absence of a polar head group leads to new material properties and gives so far unexplored possibilities to create novel smart biomaterial. [0320] New advantages in material properties can be designed by the functionalization via the conjugation of non-amino acids such as small molecules, functional groups and short linkers. [0321] These small molecule/functional group/short linkers bestow new material properties such as bio-adhesiveness and receptor-targeting. The new peptide sequence characteristics enables the development of new (and different to the one developed so far) applications. It also simplifies the purification of the desired compound. Compared to the peptide itself, the presence of the functional group/short linker at the C-terminus enhances ease of functionalization and the ability to chemically conjugate multiple bioactive molecules (such as cytokines, prodrugs etc) to a single peptidomimetic/peptidic conjugate. We can also eliminate undesired side reactions and non-specific interactions between the peptidomimetic/peptidic conjugate and bioactive molecules of interest. [0322] In a further aspect, the present invention provides the use of said hydrophobic peptides/peptidomimetics in biofabrication. [0323] Peptide self-assembly is an elegant and expedient “bottom-up” approach towards designing ordered, three-dimensional nanobiomaterials. Reproducible macromolecular nanostructures can be obtained due to the highly specific interactions that govern self-assembly. The amino acid sequence determines peptide secondary structure and interactions with other molecules, which in turn dictates the higher order macromolecular architecture. [0324] Self-assembled nanofibrillar peptide scaffolds are of great interest for applications in regenerative medicine. As their nanofibrous topography resembles the extracellular matrix, they have been extensively applied as biomimetic scaffolds, providing spatial and temporal cues to regulate cell growth and behavior. Spatially defined, large-scale three-dimensional scaffolds, incorporating cells and other biochemical cues, can be obtained by 3D microdroplet bio-printing and moulding techniques. Self-assembling peptides, peptidomimetics and peptidic conjugates can serve as building blocks for printing or moulding of biocompatible macromolecular scaffolds that support the growth of encapsulated cells. [0325] This disclosure describes a novel class of ultrashort peptides/peptidomimetics/conjugates, with a characteristic motif that facilitates self-assembly in aqueous conditions, forming porous, nanofibrous scaffolds that are biocompatible ( FIG. 1 ). Several subclasses demonstrate stimuli-responsive gelation ( FIG. 2 ) and can be used to for bio-printing of mini-hydrogel arrays and 3D organotypic biological constructs. The stimuli-responsive nature can also be exploited to produce hydrogel fibers or “noodles” through extrusion into salt solution baths. The resulting fibers can potentially be collected and used to create woven and aligned fibrous scaffolds. [0326] The characteristic motif that drives self-assembly consists of a N-terminus “tail” of 2 to 7 natural aliphatic amino acids, arranged in decreasing hydrophobicity towards the C-terminus ( FIG. 10 ). The C-terminus can be functionalized, such as with a functional group (e.g. carboxylic acid, amine, ester, alcohol, aldehyde, ketone, maleimide), small molecules (e.g. sugars, alcohols, vitamins, hydroxyl-acids, amino acids) or short polar linkers. [0327] Self-assembly in aqueous conditions occurs when the amino acids pair and subsequently stack into α-helical fibrils ( FIG. 1 ). Hydrogels are obtained when further aggregation of the fibrils into 3D networks of nanofibers entrap water ( FIG. 3A ). [0328] The presence of functional groups enables to perform chemical modifications pre- and post-assembly. For instance, bioactive moieties such as growth factors, lipids, cell-receptor ligands, hormones and drugs can be conjugated to the scaffold post-assembly, giving rise to functionalized hydrogels. [0329] Several subclasses of these peptides/peptidomimetics/conjugates demonstrate stimuli-responsive gelation ( FIG. 2 ). In particular, a subclass of peptides with lysine or lysine-mimetic molecules as the polar head group exhibit enhanced gelation and rigidity in the presence of salts and elevated pH ( FIGS. 3A , B and C). The gelation duration can be tuned by titrating the peptide and salt concentration. This opens avenues for the development of bio-printing, wherein gelation can be controlled and limited to desired areas through the co-injection of salt solutions. [0330] Furthermore, the gelation process is slightly endodermic, which adds an element of temperature-sensitivity and eliminates the possibility of thermal damage to encapsulated cells. During the process of gelation, the ability to modulate gelation duration enables to sculpt the hydrogel construct into the desired shape for applications in regenerative medicine. The mechanical properties of this subclass of peptide hydrogels are enhanced by increasing salt concentration and pH. The stiffness and tunable mechanical properties render this subclass of amidated peptides hydrogels as ideal candidates for developing biological constructs that fulfill mechanically supportive roles. Through the judicious addition of ionic buffers and bases, less peptide can be used to attain equivalent mechanical stiffness while maintaining the porosity for supporting cell migration. The ability to modulate the mechanical properties and porosity is integral to creating organotypic constructs with mechanical properties comparable to that of the native tissue. In comparison, other peptide hydrogels, based on self-assembling α-helices, β-hairpins (G′≦2 kPa) and β-sheets (G′≦2 kPa), cannot attain such high rigidity. (References: α-helices: Banwell, E. F. et al. Rational design and application of responsive alpha-helical peptide hydrogels. Nat Mater 8, 596-600 (2009). Yan, C. & Pochan, D. J. Rheological properties of peptide-based hydrogels for biomedical and other applications. Chem Soc Rev 39, 3528-3540 (2010). β-Hairpins: [0000] Yan, C. et al. Injectable solid hydrogel: mechanism of shear-thinning and immediate recovery of injectable β-hairpin peptide hydrogels. Soft Matter 6, 5143 (2010). Schneider, J. P. et al. Responsive hydrogels from the intramolecular folding and self-assembly of a designed peptide. J Am Chem Soc 124, 15030-15037 (2002). References: β-Sheets: [0000] Zhang, S., Holmes, T., Lockshin, C. & Rich, A. Spontaneous assembly of a self-complementary oligopeptide to form a stable macroscopic membrane. Proc. Natl. Acad. Sci. USA 90, 3334-3338 (1993). Liu, J., Zhang, L., Yang, Z. & Zhao, X. Controlled release of paclitaxel from a self-assembling peptide hydrogel formed in situ and antitumor study in vitro. Int J Nanomedicine 6, 2143-2153 (2011). Aggeli, A. et al. Responsive gels formed by the spontaneous self-assembly of peptides into polymeric beta-sheet tapes. Nature 386, 259-262 (1997).) [0338] As a proof-of-concept, this subclass of peptides was used to demonstrate the feasibility of bio-printing to develop mini-hydrogel arrays and 3D organoid structures for screening and regenerative medicine. This subclass of peptides demonstrates good solubility in water, forming solutions with low viscosity. This facilitates the printing and prevents the clogging of the needle/printer. Upon interacting with a physiological salt solution (such as phosphate buffered saline, PBS), the peptide solution gels instantaneously. As shown in FIG. 3D , arrays of microdroplets will form mini-hydrogels that adhere to a glass or polystyrene surface upon washing with PBS. [0339] The peptides/peptidomimetics are biocompatible. Stem cells (mesenchymal, progenitor, embryonic and induced pluripotent stem cells) and primary cells isolated from patient samples (fibroblasts, nucleus pulposus) can be mixed with the peptide during the dispensing process ( FIG. 4 ). Following gelation, the cells are immobilized to the drop. Nanoparticles, small molecule drugs, oligonucleotides, and proteins can be similarly co-encapsulated ( FIGS. 4 and 5 ). [0340] Coupled with the advent of high-throughput histological screening using slide scanners, this technology can be used to evaluate different test compounds using minimal cell numbers on a single microscope slide ( FIG. 6 ). [0341] By incorporating cross-linkers, we can improve the mechanical stability of these mini-hydrogels. Bioactive functionalities can be also incorporated through mixing or cross-linking with polymers ( FIG. 7 ). [0342] We can mix different peptides/peptidomimetics/conjugates without compromising their propensity for self-assembly. This allows us to combine different compounds to access different functional groups for conjugation and vary the bulk properties. [0343] Extending the technology towards 3D microdroplet printing and moulding, biological, organotypic constructs with distinct, multi-functional micro-niches can be obtained ( FIG. 8 ). Multi-cellular constructs can also be obtained as the hydrogel can spatially confine different cell types during the printing process. The peptide/peptidomimetic/conjugate scaffold will provide the co-encapsulated cells with mechanical stability. Genes, small molecules and growth factors can be co-delivered to enhance cell survival, promote stem cell differentiation and modulate the host immune response. The resulting 3D biological constructs can be used as organoid models for screening drugs, studying cell behavior and disease progression, as well as tissue-engineered implants for regenerative medicine. [0344] In addition to microdroplets, also obtain fibres (“noodles”) can be obtained by extruding the peptidic solution into a high concentration salt solution ( FIG. 3E ). Co-encapsulation of cells and bioactive moieties can be performed. The fibrous microenvironment can give rise to new applications such as woven scaffolds, aligned scaffolds and 3D patterned co-culture scaffolds. Key Features: [0000] A novel class of peptides/peptidomimetics/conjugates which only consists of 2 to 7 amino acids which can self-assemble into nanofibrous scaffolds. The significantly shorter sequence implies a lower cost and ease of synthesis and purification compared to other self-assembling peptide/conjugate technologies. An interesting mechanism of self-assembly into nanofibrous scaffolds in aqueous conditions and polar solvents. Such scaffolds can provide mechanical cues for cellular and tissue regeneration (biomimetic scaffold). A versatile material which can be formulated in different ways. Some subclasses are stimuli-responsive, which facilitates the development of bio-printing technologies. Several subclasses demonstrate stimuli-responsive behavior which can be exploited for various applications. A subclass of peptides demonstrates salt and pH-responsive gelation. In particular, instantaneous gelation can be obtained upon exposure to a physiologically compatible salt solution. When dissolved in water, the peptidic solution has low viscosity and can be easily dispensed through needles and print-heads. This minimizes the possibility of clogging. The stimuli-responsiveness can also be exploited to generate hydrogel fibers/′ noodles′. These fibers can subsequently be aligned or woven to create innovative scaffolds for tissue engineering and disease models. On a macroscale, we can also use moulds (such as those made of silicone) to pattern the hydrogels in a 3D fashion. The hydrogels are biocompatible and can be used to encapsulate cells. Upon gelation, the resulting hydrogel is stable and not easily dissociated. Therefore, encapsulated cells cannot escape. Bioactive moieties, such as oligonucleotides, proteins and small molecule drugs, as well as nano- and microparticles, can be co-encapsulated to influence cell behavior. Drug release can also be modulated by porosity and various molecular interactions. Post-assembly modifications are feasible due to the presence of functional groups. Large proteins such as growth factors can also be conjugated to the peptidic backbone or functional groups on the conjugate to modulate biological behavior. Examples [0355] Experiments have been performed to illustrate the technical aspects of exemplary embodiments of the present invention. The following examples are described in the Experimental Methods and Results. The skilled artisan will readily recognize that the examples are intended to be illustrative and are not intended to limit the scope of the present invention. Experimental Methods and Results Circular Dichroism (CD) Spectroscopy [0356] Secondary peptide structures were analyzed by measuring ellipticity spectra using the Aviv Circular Dichroism Spectrometer, model 410. CD samples were prepared by diluting stock peptides solutions (5-10 mg/ml) in water. The diluted peptide solutions were filled in to a cuvette with 1 mm path length and spectra were acquired. As a blank reference water was used and the reference was subtracted from the raw data before molar ellipticity was calculated. The calculation was based on the formula: [θ] λ =θ obs ×1/(10 Lcn), where [θ] λ□ is the molar ellipticity at λ in deg cm 2 d/mol, is the observed ellipticity at □λ in mdeg, L is the path length in cm, c is the concentration of the peptide in M, and n is the number of amino acids in the peptide. Secondary structure analysis was done using CDNN software. Environmental Scanning Electron Microscopy (ESEM) [0357] Samples were placed onto a sample holder of FEI Quanta 200 Environmental Scanning Electron Microscopy. The surface of interest was then examined using accelerating voltage of 10 kV at a temperature of 4° C. Field Emission Scanning Electron Microscopy (FESEM) [0358] Samples were frozen at −20° C. and subsequently to −80° C. Frozen samples were further freeze dried. Freeze dried samples were fixed onto a sample holder using conductive tape and sputtered with platinum from both the top and the sides in a JEOL JFC-1600 High Resolution Sputter Coater. The coating current used was 30 mA and the process lasted for 60 sec. The surface of interest was then examined with a JEOL JSM-7400F Field Emission Scanning Electron Microscopy system using an accelerating voltage of 5-10 kV. Preparation of Hydrogel Droplets [0359] We obtained hydrogel arrays by simply dispensing small volume droplets (0.5, 1, 2, 5, 10 and 20 μL) of peptide solution and subsequently mixing or washing with PBS. The viscosity and rigidity increases significantly upon gelation, conferring high shape fidelity, which enables us to localize the hydrogel droplets to the site of deposition, control the internal composition and suspend encapsulated cells or bioactive moieties, two important criteria for bioinks. To date, we have generated hydrogel droplet arrays of various volumes, encapsulating small molecules, DNA, mRNA, nanoparticles, proteins and cells. Encapsulation of Human Mesenchymal Stem Cells [0360] Human mesenchymal stem cells were obtained from Lonza (Basel, Switzerland) and cultured in α-MEM medium with 20% fetal bovine serum, 2% L-glutamine and 1% penicillin-streptomycin. Upon trypsinization, the cells were suspended in PBS and subsequently added into or onto peptide solutions (in PBS). The constructs were then allowed to gel at 37° C. for 15 minutes before media was added. [0000] Hydrophobic Peptides which Self-Assemble into Nanofibrous Hydrogels [0361] Materials. [0362] All peptides used in this study were manually synthesized by American Peptide Company (Sunnyvale, Calif.) using solid phase peptide synthesis and purified to >95% via HPLC. Amino acid and peptide content analysis were performed. [0363] Preparation of Hydrogels. [0364] To prepare the peptide hydrogels, the lyophilized peptide powders were first dissolved in milliQ water and mixed by vortexing for 30 seconds to obtain a homogenous solution. The gelation occurred between minutes to overnight, depending on the peptide concentration. Gelation can be facilitated by sonication or heating. [0365] Functionalization of C-Terminus. [0366] To functionalize the C-terminus, biotin and L-DOPA was incorporated during solid phase peptide synthesis by first reacting the Fmoc protected precursor to the Wang or Rink-amide resin. The final product was purified using HPLC/MS, lyophilized and evaluated for gelation. [0367] Field Emission Scanning Electron Microscopy. [0368] Hydrogel samples were flash frozen in liquid nitrogen and subsequently freeze-dried. Lyophilized samples were sputtered with platinum in a JEOL JFC-1600 High Resolution Sputter Coater. Three rounds of coating were performed at different angles to ensure complete coating. The coated sample was then examined with a JEOL JSM-7400F FESEM system using an accelerating voltage of 2-5 kV. [0369] The listing or discussion of a previously published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge. All documents listed are hereby incorporated herein by reference in their entirety for all purposes. [0370] Exemplary embodiments of the invention illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising”, “including,” containing”, etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by exemplary embodiments and optional features, modification and variation of the inventions embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention. [0371] The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein. [0372] Other embodiments are within the following claims. In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.

The present invention relates to hydrophobic peptides and/or peptidomimetics capable of forming a (nanofibrous) hydrogel and hydrogels comprising said hydrophobic peptides and/or peptidomimetics and to various uses, such as in regenerative medicine, injectable therapies, delivery of bioactive moieties, wound healing, 2D and 3D synthetic cell culture substrate, biosensor development, biofunctionalized surfaces, and biofabrication.

This application claims priority to provisional application No. 60/969,066 that was filed on Aug. 30, 2007. TECHNICAL FIELD The present application relates generally to the field of artificial lifts, and more specifically to artificial lifts in connection with hydrocarbon wells, and more specifically, associated downhole oil/water separation methods and devices. BACKGROUND Oil well production can involve pumping a well fluid that is part oil and part water, i.e., an oil/water mixture. As an oil well becomes depleted of oil, a greater percentage of water is present and subsequently produced to the surface. The “produced” water often accounts for at least 80 to 90 percent of a total produced well fluid volume, thereby creating significant operational issues. For example, the produced water may require treatment and/or re-injection into a subterranean reservoir in order to dispose of the water and to help maintain reservoir pressure. Also, treating and disposing produced water can become quite costly. One way to address those issues is through employment of a downhole device to separate oil/water and re-inject the separated water, thereby minimizing production of unwanted water to surface. Reducing water produced to surface can allow reduction of required pump power, reduction of hydraulic losses, and simplification of surface equipment. Further, many of the costs associated with water treatment are reduced or eliminated. However, successfully separating oil/water downhole and re-injecting the water is a relatively involved and sensitive process with many variables and factors that affect the efficiency and feasibility of such an operation. For example, the oil/water ratio can vary from well to well and can change significantly over the life of the well. Further, over time the required injection pressure for the separated water can tend to increase. Given that, the present application discloses a number of embodiments relating to those issues. SUMMARY An embodiment is directed to a downhole device comprising an electric submersible motor; a pump connected with the electric submersible motor, the pump having an intake and an outlet; the electric submersible motor and the pump extending together in a longitudinal direction; an oil/water separating device having an inlet in fluid communication with the pump outlet and having a first outlet and a second outlet, the first outlet connecting with a first conduit and the second outlet connecting with a second conduit; a redirector integrated with the first conduit and the second conduit, the redirector having a flow-restrictor pocket that extends in the longitudinal direction, a downhole end of the flow-restrictor pocket connecting with a re-injection conduit; the first conduit extending uphole to a level of the flow-restrictor pocket, and the second conduit extending farther uphole than the first conduit; the uphole end of the flow-restrictor pocket connecting with the second conduit; and a passage connecting the first conduit with the flow-restrictor pocket. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows a configuration of an embodiment; FIG. 2 shows a portion of a cross section of an embodiment; FIG. 3 shows a portion of a cross section of an embodiment; FIG. 4 shows a portion of a cross section of an embodiment; FIG. 5 shows a configuration of an embodiment; FIG. 6 shows a cross section of a portion of an embodiment; FIG. 7 shows a cross section of portion of an embodiment; FIG. 8 shows a cross section of a portion of an embodiment; and FIG. 9 shows a cross section of a portion of an embodiment in use. DETAILED DESCRIPTION In the following description, numerous details are set forth to provide an understanding of the present invention. However, those skilled in the art will understand that the present invention may be practiced without many of these details and that numerous variations or modifications from the described embodiments may be possible. In the specification and appended claims: the terms “connect”, “connection”, “connected”, “in connection with”, and “connecting” are used to mean “in direct connection with” or “in connection with via another element”; and the term “set” is used to mean “one element” or “more than one element”. As used herein, the terms “up” and “down”, “upper” and “lower”, “upwardly” and downwardly”, “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly described some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate. The present application relates to downhole oil/water separation, and more particularly, advantageously managing back-pressure to manipulate the oil/water separation. One way to advantageously control separation of fluids is by regulating back-pressure applied to the oil stream and/or the water stream. One way to regulate back-pressure is by regulating a flow-restriction (i.e., throttling) of the oil stream and/or the water stream exiting the oil/water separator. Embodiments herein relate to equipment that allows a stream to be throttled, i.e., a back-pressure to be manipulated. The magnitude of a throttling can cover a range from completely closed to wide open depending on the oil/water content of the well fluid. The form and function controlling backpressure and related flow is highly dependent upon the injection zone orientation relative to the producing zone (injection zone uphole or downhole of the producing zone). Some key differences between the two orientations relate to injecting uphole where the device can throttle and vent to a tubing annulus in a single operation, and injecting downhole where the device may need to throttle the flow “in-line”, .i.e. receive the injection flow from the tubing, throttle the flow, and then return the flow to another tube headed toward the injection zone. Some or all of these factors can be considered. The diameter of a throttle opening can generally be from 0.125 to 1.0 inches. FIG. 1 shows an overall schematic for an embodiment of a device. Some of the main components of the device are an ESP 100 comprising a motor 110 and a pump 120 . A centrifugal or cyclone oil/water separator 200 is connected adjacent to the pump 120 . The apparatus is placed downhole in a hydrocarbon well, preferably inside a well casing 10 . The motor 110 drives the pump 120 . The motor 110 also drives the oil/water separator 200 . During operation, well fluid is drawn into the pump 120 through a vent 125 . The oil/water mixture is driven out of the pump 120 and into the oil/water separator 200 , a centrifugal type separator in this case. The oil/water separator 200 accelerates and drives the oil/water mixture in a circular path, thereby utilizing centrifugal forces to locate more dense fluids (e.g., water) to a farther out radial position and less dense fluids (e.g., oil) to a position nearer to the center of rotation. An oil stream and a water stream exit the oil/water separator 200 and travel separately along different paths to a redirector 250 , where the water stream is redirected and re-injected into formation while the oil stream is directed uphole to surface. FIG. 2 shows a cut away view of the oil/water separator 200 , which is of the centrifugal type. A well fluid mixture is driven into and rotated in a cyclone chamber 201 of the oil/water separator 200 . The layers of the stream are separated by a divider 202 that defines a beginning of an oil conduit 204 and a beginning of a water conduit 206 . The oil conduit 204 is further inward in a radial direction with respect to the water conduit 206 . Back-pressure of the streams affects the oil/water separation process. For example, for well fluids having a high percentage of oil, higher back-pressure for the water stream 206 can improve separation results. Similarly, for well fluids having a higher percentage of water, a higher back-pressure for the oil stream 204 can improve oil/water separation. Essentially the same back-pressure principal applies to cyclone type oil/water separators. FIG. 3 shows another sectional view of the oil/water separator 200 having the oil conduit 204 and the water conduit 206 . Arrows 350 show a representative path of the oil stream. Arrows 355 show a representative path of the water stream. A flow-restrictor 304 , e.g., a throttle, is in the water conduit 206 . The water stream flows uphole into the flow-restrictor 304 . The flow-restrictor 304 could be located in the oil conduit 204 . One flow-restrictor 304 could be in the water conduit 206 and another flow-restrictor 304 could be in the oil conduit 206 simultaneously. Selection of a flow-restrictor 304 from a number of different flow-restrictors having different variations of orifice size and configuration enables adjustment of the aforementioned backpressure in the water stream 206 . There are many ways to replace the flow-restrictor 304 with another different flow-restrictor 304 having a different throttle, thereby adjusting the backpressure situation. Preferably, a wireline tool can be lowered to place/remove a flow-restrictor 304 . A flow-restrictor 304 can also be inserted and removed using slickline, coiled tubing, or any other applicable conveyance method. Slickline tends to be the most economical choice. In connection with use of a slickline, or coiled tubing for that matter, the oil stream channel is preferably positioned/configured to prevent tools lowered down by wireline, slickline or coiled tubing from inadvertently entering the oil conduit 204 . The oil conduit 204 can be angled to prevent the tool from entering the oil conduit 204 . The oil conduit 204 can further be sized such that the tool will not be accepted into the bore. Alternately, the flow-restrictor 304 can have a variable size throttle orifice so that replacement of the flow-restrictor is not required to vary orifice size. The orifice size can be varied mechanically in many ways, e.g., at surface by hand, by a wireline tool, a slickline tool, a coil tubing tool, a hydraulic line from the surface, by an electric motor controlled by electrical signals from the surface or from wireless signals from the surface, or by an electrical motor receiving signals from a controller downhole. Check valves 302 can be located in the oil conduit 204 and/or the water conduit 206 . The check valves 302 can prevent fluid from moving from the oil conduit 204 and the water conduit 206 down into the oil/water separator 200 , thereby causing damage to the device. Packers can be used to isolate parts of the apparatus within the wellbore. For example, FIG. 1 shows packers 410 and 420 isolating an area where water is to be re-injected into the formation from an area where well fluid is drawn from the formation. The packer configuration effectively isolates the pump intake from re-injection fluid. Alternately, the packer 420 could be located below the pump 200 , so long as the water is re-injected above the packer 410 or below the packer 420 , thereby adequately isolating the area where the well fluids are produced from the area of the formation where water is re-injected. No specific packer configuration is required, so long as isolation between producing fluid and injecting fluid is adequately achieved. The above noted configurations can also be used to inject stimulation treatments downhole. FIG. 4 shows the apparatus of FIG. 3 except with the flow-restrictor 304 removed. FIG. 4 shows pumping of stimulating treatments down the completion tubing and into both the oil conduit 204 and the water conduit 206 . A flow-restrictor can be replaced with a flow device that prevents treatment fluid from following along the path of re-injection water. The arrows 360 illustrate a representative path of the stimulating treatment. The check valves 302 can prevent the stimulation fluid from traveling into the oil/water separation 200 , thereby potentially causing detrimental effects. FIG. 5 shows a configuration to re-inject a water stream to a zone located below the producing zone. A motor 110 , a pump 120 , and an oil/water separator 200 are connected as before. A redirector 250 is connected uphole from the oil/water separator 200 . The redirector 250 is connected to a conduit 260 that extends downhole from the re-injection and through a packer 420 . The packer 420 separates a production area that is uphole from the packer 420 , from a re-injection area that is downhole from the packer 420 . In that embodiment, the water stream travels through a tailpipe assembly 270 . The tailpipe assembly 270 extends though the packer 420 into the re-injection area that is downhole from the packer 420 . FIG. 6 shows a more detailed cross section of an embodiment of the redirector 250 . FIG. 9 shows a cross section of a redirector 250 and a flow-restrictor 304 in operation with the flow-restrictor 304 positioned in the flow-restrictor pocket 610 . The flow-restrictor pocket 610 is configured to receive a flow-restrictor 304 . The water conduit 206 is configured to be radially outside the oil conduit 204 , i.e., a centrifugal oil/water separation. The oil conduit 204 extends from down-hole of the redirector 250 , through the redirector 250 , and uphole past the redirector 250 , where the oil conduit 204 connects with production tubing 620 (e.g., coil tubing). The water conduit 204 extends from below the redirector 250 and into the redirector 205 . The water conduit 204 merges into a water passage 630 that connects the water conduit 204 with the flow-restrictor pocket 610 . The water passage 630 can extend in a direction substantially perpendicular to the water conduit 204 proximate to the water passage. That is, during operation, the flow of the water makes approximately a 90 degree turn. The water can alternately make as little as approximately a 45 degree turn and as much as approximately a 135 degree turn. A re-injection passage 670 extends from the flow-restrictor pocket 610 downhole past the redirector 250 . The re-injection passage 670 can be connected with completion tubing or other tubing. FIG. 7 shows an embodiment of the flow-restrictor 304 . The flow-restrictor 304 has a body 701 that defines therein an upper inner chamber 725 and a lower inner chamber 720 . The upper inner chamber 725 and the lower inner chamber 720 are divided by a flow-restriction orifice 740 . The flow-restriction orifice 740 and the body 701 can be the same part, or two separate parts fit together. Preferably the flow-restriction orifice 740 has a narrower diameter in a longitudinal axial direction than either the upper inner chamber 725 or the lower inner chamber 720 . However, the diameter of the flow-restriction orifice 740 can be essentially the same diameter of either the upper inner chamber 725 or the lower inner chamber 720 . Passages 710 are located in the body 701 and hydraulically connect the upper inner chamber 725 with an outside of the flow-restrictor 304 . Passage 715 is on the downhole end of the flow-restrictor 304 . When the flow-restrictor 304 is in position in the flow-restrictor pocket 610 , the passages 710 allow fluid to pass from the water passage 630 , though the passages 710 and into the upper inner chamber 725 . The fluid then flows through the restrictor orifice 740 , into the lower inner chamber 720 and out of the flow-restrictor 304 for re-injection. It should be noted that the flow-restrictor 304 can have many internal configurations, so long as the flow is adequately restricted/throttled. The flow-restrictor 304 has an attachment part 702 that is used to connect to a downhole tool (not shown) to place and remove the flow-restrictor 304 from the flow-restrictor pocket 610 . As noted earlier, the downhole tool can be connected to any relay apparatus, e.g., wireline, slickline, or coiled tubing. There are many ways to determine an oil/water content of a well fluid. Well fluid can be delivered to surface where a determination can be made. Alternately, a sensor can be located downhole to determine the oil/water ratio in the well fluid. That determination can be transmitted uphole in many ways, e.g., electrical signals over a wire, fiber-optic signals, radio signals, acoustic signals, etc. Alternately, the signals can be sent to a processor downhole, the processor instructing a motor to set a certain orifice size for the flow-restrictor 304 based on those signals. The sensor can be located downstream from the well fluid intake of the oil/water separator, inside the oil/water separator, inside the redirector, inside the flow-restrictor, upstream of the oil/water separator, outside the downhole device and downhole of the well fluid intake, outside the downhole device and uphole of the sell fluid intake, or outside the downhole device and at the level of the well fluid intake. One embodiment shown in FIG. 8 has a flow-restrictor 304 having a sensor 800 located in the upper inner chamber 725 . The sensor could be in the lower inner chamber 720 . The sensor 800 can sense temperature, flow rare, pressure, viscosity, or oil/water ratio. The sensor 800 can communicate by way of a telemetry pickup 810 that is integrated with the redirector 250 . The sensor 800 can communicate through an electrical contact or “short-hop” telemetry with a data gathering system (not shown). The preceding description refers to certain embodiments and is not meant to limit the scope of the invention.

A downhole device having an oil/water separator having a well fluid inlet, an oil stream outlet conduit, and a water stream outlet conduit; a removable flow-restrictor located in at least one of the water stream outlet conduit or the oil stream outlet conduit.

FIELD OF THE INVENTION [0001] The present invention relates to an apparatus and method of deploying a desuperheater with a Seat-Ring designed to provide coolant injection at high temperature differential. The present invention's robust design provides for a high level of flexibility that allows operating at high temperature differentials between the coolant and the superheated fluid. The desuperheater Seat-Ring is made as a split hollow ring with a perpendicular slit traversing the ring's circumference. The opened slit design provides a high level of flexibility, which allows the seat ring to sustain severe temperature extremes by reducing thermal stress. The coolant is supplied to the seat ring through a specially designed coolant nipple liner connected to the seat-ring. BACKGROUND OF THE INVENTION [0002] In the operation of steam and boiler systems, it is often the case that steam which is available for use will be at a temperature much greater than is necessary or desired for a particular end use. In such cases, it is customary to utilize a desuperheater, by which a fluid, usually water is injected into the flowing stream of high temperature steam and subsequently mixed. Ideally, the injected fluid itself almost immediately turns to steam, serving to convert the incoming, high temperature steam to a somewhat larger volume of steam at a lower temperature, that is, the steam will have less superheat. [0003] An earlier patent granted to Sanford S. Bowlus, U.S. Pat. No. 2,945,685, discloses an advantageous form of automatic desuperheater device, known as a variable orifice desuperheater. In the device of the Bowlus patent, incoming steam, traveling vertically upward through a desuperheater housing inlet, was arranged to lift against gravity a weighted valve element. The extent to which the valve element opened is automatically a function of the volume and velocity of the incoming steam. [0004] Surrounding the weighted valve element is a small orifice communicating with a source of desuperheating water. When steam is flowing through the system the weighted valve element is lifted, resulting in a high velocity flow of the steam around the valve and an atomizing action of the steam on the surrounding water. The arrangement is such that, relatively independently of the volume of steam flow within reasonable limits, there will be an effective atomizing action of the steam upon the water. The amount of water injected into the desuperheater and combined with the incoming steam is controlled independently, as a function of steam temperature. [0005] In basic principle, the variable orifice desuperheater of the Bowlus U.S. Pat. No. 2,945,685 is highly effective in operation. Thus, the present invention seeks to utilize the significant operative principles of the earlier Bowlus patent, while at the same time incorporating such principles into a substantially improved physical embodiment, which is more resistant to thermal fatigue than prior devices and at the same time less costly to produce and maintain. These advantages are achieved without sacrifice of performance and, indeed, with improvement in performance in certain respects. [0006] For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment and to the accompanying drawings. SUMMARY OF THE INVENTION [0007] Embodiments of the present invention advantageously provide for a variable orifice desuperheater device for in-line operation in conjunction with upstream and downstream piping, comprising A desuperheating device for in-line operation in conjunction with superheated fluid piping upstream and downstream therefrom and of type comprising an upper housing section and a lower housing section joined with a middle housing chamber of enlarged diameter relative to the upstream and downstream piping to form a mixing chamber of enlarged diameter relative to the upstream and downstream piping, wherein said joined housing sections being adapted for connection to said upstream and downstream piping. It also includes a desuperheater seat ring support fixed in said middle housing and supporting therewith an annular seat injection ring with a slot and said annular seat injection ring being adapted for connection to a cooling fluid inlet piping to supply a cooling fluid to said annular seat injection ring and an axially disposed valve cage base structure mounted on said desuperheater seat ring support and a valve plug slideably received in the axially disposed valve cage base structure to cooperate with said slot of said annular seat injection. [0008] Another embodiment is for a method for cooling a superheated fluid with a desuperheater device, which comprises receiving at a lower section of a desuperheater device, said superheated fluid and flowing said superheated fluid though a variable orifice in a middle section of said desuperheater device and flowing a cooling liquid into said middle section. The method also include mixing said superheated fluid and said cooling liquid in said middle section to produce a less superheated fluid and flowing said less superheated fluid out of said desuperheater device through an upper section. [0009] An alternative embodiment is for the means for cooling a superheated fluid with a desuperheater device, including the means for receiving at a lower section of said desuperheater device said superheated fluid and the means for flowing said superheated fluid though a variable orifice in a middle section of said desuperheater device and the means for flowing a cooling liquid into said middle section. It further includes the means for mixing said superheated fluid and said cooling liquid in said middle section to produce a less superheated fluid and the means for flowing said less superheated fluid out of said desuperheater device through an upper section [0010] There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. [0011] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. [0012] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0013] The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will be better understood by reference to the following description of various embodiments of the disclosure taken in conjunction with the accompanying figures. [0014] FIG. 1 is a cross sectional view of the desupheater valve of an embodiment of the present invention. [0015] FIG. 1 a is a close up cross sectional view of the desupheater valve of an embodiment of the present invention. [0016] FIG. 2 is a plan view of the seat ring deployed in an embodiment of the present invention. [0017] FIG. 3 is a sectional slice view of the seat ring. [0018] FIG. 4 is a view of the seat ring ends of the seat ring. [0019] FIG. 5 illustrates a cutaway view of a desuperheater valve with flange connection. [0020] FIG. 6 is a plan view of the seat ring deployed in another embodiment of the present invention. [0021] FIG. 7 is a slide view of the seat ring showing the cooling fluid inlet which is deployed inside the seat ring. [0022] FIG. 8 is a side view orientation of the seat ring and its location in conjunction with seat ring support of the embodiment show in FIG. 6 . DETAILED DESCRIPTION OF THE INVENTION [0023] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof and show by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice them, and it is to be understood that other embodiments may be utilized, and that structural, logical and processing changes may be made. It should be appreciated that any list of materials or arrangements of elements is for example purposes only and is by no means intended to be exhaustive. The progression of processing steps described is an example; however, the sequence of steps is not limited to that set forth herein and may be changed as is known in the art, with the exception of steps necessarily occurring in a certain order. [0024] The Desuperheater consists of a body which houses the desuperheater internals. The body incorporates a seat over which a cage is located in such a manner that a coolant annulus is created around the seat. The coolant enters this annulus by means of a branch on the desuperheater body. The plug is free floating, but incorporates a spring-loaded stability button which provides stability to the plug under light load conditions. Incorporated in the top of the cage is a plug stop to limit the amount of travel of the plug. [0025] In service, incoming vapor acts on the underside of the plug, which is weighted in such a manner that a certain amount of the energy in the vapor is used to lift the plug. As more vapor flows through the desuperheater, the higher the plug is lifted, thus creating a variable orifice for the vapor flow. The energy used in lifting the plug creates a pressure drop across the seat which is quite constant regardless of the vapor flow. This pressure drop creates a relatively high velocity across the seat area, and it is at this point of low pressure constant velocity that the coolant is admitted into the vapor flow. [0026] Coolant enters the annulus under the dictates of a control valve responsive to a temperature controller sensing the downstream vapor temperature. The coolant is admitted into the vapor flow through a peripheral gap between the underside of the cage and the top of the seat. Coolant is admitted via slot located around the circumference of the seat to ensure that unequal cooling does not occur. [0027] The coolant is picked up by the vapor flow as it discharges from the seat, and the low pressure zone that exists at this point is instrumental in atomizing the coolant into fine particles. In the turbulence which ensues as a result of the change in direction and velocity of the vapor, intimate mixing of the vapor and coolant takes place. Above the plug, as the vapor attempts to return to laminar flow, a vortex is created and any particles of coolant not completely absorbed by the vapor are drawn into this vortex where they suffer a further pressure reduction which again speeds up the atomizing process. [0028] As virtually all of the desuperheating occurs within the desuperheater body itself, and as no coolant impinges on either the desuperheater or associated piping, no protective thermal liners for downstream piping are required. [0029] FIGS. 1 and 1 a are a cross sectional views of an embodiment of the present invention. The desuperheater valve assembly 10 has three sections, a desuperheated fluid outlet or upper housing section 22 , a middle housing section 26 and a superheated fluid inlet or lower housing section 20 . They are joined together by welds 2 . Although the welds are shown as a single welded butt joint, the joining of the upper housing section 22 , the middle housing section 26 and the lower housing section 20 can be accomplished by any coupling method or casting method. [0030] Inside the housing 26 , the segment rings 18 can be found adjacent to the seat support ring 42 . The seat support ring 42 holds and supports the annular seat injection ring 16 . A spacer ring 44 is located above the seat injection ring 16 . The valve cage base structure 38 is axially disposed inside the valve assembly and is on the downstream side of the spacer ring 44 . In this embodiment, the cage base structure 38 is welded to the housing 26 . A thermal liner 24 is attached to the cage base structure 38 and is positioned between the housing 26 and the internal cage 46 . Cage ribs 36 are located positioned above the cage base 38 . The plug stop 28 is located at the top of the internal cage 46 to limit travel of the plug assembly 40 . The plug assembly 40 includes a locking pin 30 , a loading spring 32 and a stability button 34 to provide stability to the plug under light load conditions. The thermal liner 24 is attached to the cage base structure 38 and is free to expand and contract reliving thermal stresses and protecting the housing 26 from thermal stress cracking. It may be attached, for example, by a welding process. [0031] In operation, the cooling fluid enters the desuperheater valve through the cooling manifold fluid inlet 12 and flows through a first end of the coolant thermal sleeve 14 . The coolant thermal sleeve protects the weld joints and also reduces thermal stresses, extending design live of the unit. The coolant thermal sleeve 14 has piston rings 48 positioned about the coolant thermal sleeve 14 to permit movement of the thermal sleeve 14 within the cooling manifold 12 . The other end of the thermal sleeve 14 is positioned inside the annular seat injection ring 16 . [0032] Now, referring to FIGS. 1-4 , the seat injection ring 16 is hollow and is shaped like a torus and includes a coolant nipple 17 attached to receive a cooling fluid. For example, the cooling fluid could be water, which is injected into the superheated fluid flowing through the desuperheater valve assembly 10 . As discussed above, the superheated fluid is moving through the desuperheater device, the plug assembly 40 will move away from the seat injection ring 16 creating an atomizing orifice area and the cooling fluid is then dispersed into the superheated fluid via slot 21 . The slot 21 travels around the circumference of the annular seat injection ring 16 . The cooling fluid is pulled into the superheated vapor flow and the low pressure zone that exists at this point is aids in atomizing the cooling fluid into fine particles. [0033] In this embodiment, the seat injection ring 16 is interrupted by two seat ring ends 19 and are attached by welds 2 a . The interruption permits the seat injection ring 16 to expand and contract without causing damage to the device. For example, when the ring becomes heated and expands, the gap between the two seat ring ends 19 will narrow. However, depending on the temperatures involved in the operation of the desuperheater valve and the materials making up the desuperheater valve itself, other configurations of the seat injection ring 16 can be deployed. For example, the seat ring could be continuous, without the interruption and would not need the seat ring ends 19 . The seat injection ring 16 many also employ only one seat ring end 19 to distribute the cooling liquid in a particular manner. [0034] When the desuperheater valve operation is closed, the plug assembly 40 meets up with the seat injection ring 16 covering the slot 21 . As the superheated fluid enters the desuperheater valve and the pressure builds, the generally cylindrical valve plug assembly 40 lifts, permitting the cooling fluid to with the superheated fluid, and thus lowering the temperature of the superheated fluid. FIG. 5 illustrates a cutaway view of the desuperheater valve of the present invention showing parts placement. [0035] Now referring to FIGS. 6-8 , the coolant nipple 17 is placed inside the seat injection ring 16 . This configuration provides valve designers more flexibility when sizing and scaling desuperheater valves. FIG. 8 illustrates an inner inlet seat ring support 43 which would accommodate the coolant nipple 17 if it were to be placed inside the seat injection ring 16 . [0036] The desuperheater valve can be made out of various temperature and pressure tolerant materials. For example, the desuperheater valve can be made out of carbon steel, stainless steel and other types of low alloy steel. [0037] The processes and devices in the above description and drawings illustrate examples of only some of the methods and devices that could be used and produced to achieve the objects, features, and advantages of embodiments described herein and embodiments of the present invention can be applied to indirect dry, direct dry and wet type heat exchangers. Thus, they are not to be seen as limited by the foregoing description of the embodiments, but only limited by the appended claims. Any claim or feature may be combined with any other claim or feature within the scope of the invention. [0038] The many features and advantages of the invention are apparent from the detailed specification, and, thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and, accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the invention.

The present invention relates to an apparatus and method of deploying a desuperheater with a Seat-Ring designed to provide coolant injection at high temperature differential. The present invention's robust design provides for a high level of flexibility that allows operating at high temperature differentials between the coolant and the superheated fluid. The desuperheater Seat-Ring is made as a split hollow ring with a perpendicular slit traversing the ring's circumference. The opened slit design provides a high level of flexibility, which allows the seat ring to sustain severe temperature extremes by reducing thermal stress. The coolant is supplied to the seat ring through a specially designed coolant nipple liner connected to the seat-ring.

RIGHTS OF THE U.S. GOVERNMENT The government of the United States of America has certain rights to this invention pursuant to National Science Foundation Grant No. INT 8520639. This is a divisional of copending application(s) Ser. No. 07/210,259 filed on June 23, 1988, now U.S. Pat. No. 4,985,612. PRIORITY Priority is claimed of Bulgarian Authorship (Patent) application filed under Ser. No. 81312 for "Method for Welding and Laminating Polyamides" on Sept. 29, 1987, in Sofia, Bulgaria. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for welding and laminating polyamides applicable to the production of various articles widely used in the national economy. 2. Prior Art It is known that polymer (including polyamide) laminate, can be obtained using special glues or bonding chemicals as well as dry self-bonding (e.g., of polyamide foils) at high temperatures under pressure (New Linear Polymers, H. Lee, D. Stoffery and K. Neville, McGraw-Hill Book Company (1967)). The disadvantages of these methods are the requirements for the use of complex and expensive chemical compounds and high energy consumption. Furthermore, the bonding is not always satisfactory, and the bonding compounds are often deleterious with respect to the properties of the polymer used, e.g., they lower its thermal stability. Laminating of oriented foils at high temperature by self-bonding leads to a decrease in the degree of orientation and hence to deterioration of the physico-mechanical characteristics of the laminate obtained. It is known that polyamide-6 can be crosslinked in the amorphous regions by methoxy-methylation (methylene bridges bond together the amide groups of neighboring macrochains) (1. Arakawa, F. Nagatoshi and N. Arai, J. Polym. Sci., Polym. Lett. Ed., 6 513-516 (1968)). For this purpose, polyamide is dipped into a solution of paraformaldehyde in methanol with the addition of small amounts of potassium hydroxide and anhydrous oxalic acid. After 30 hours at 30° C., the crosslinking agent penetrates into the polymer and reacts with the amide groups, making bridges of methylene groups. Crosslinking improves the polymer strength but it has the following disadvantages. When carried out on polymer granules, the subsequent processing of the polymer will be hampered due to the rise of the viscosity of its melt. Moreover, since the penetration of the crosslinking agent into the polymer is a slow diffusion process, the methoxy-methylation of polyamide articles having a considerable volume can prove too time-consuming from the viewpoint of its application on an industrial scale. DESCRIPTION OF THE INVENTION The object of this invention is to provide a method for welding and laminating polyamides by creating a chemical bond between separate polyamide bodies and avoiding residual substances which could change the polyamide properties and the use of severe conditions (high temperature) which worsen the quality of the starting polymer material, especially in the case when the latter has been subjected to a preliminary orientation. In this invention, welding (or lamination) of a polymer containing amide groups is carried out by the creation of methylene bridges between the nitrogen atoms of two closely situated amide groups. In this case, the methoxy-methylation reaction occurs between the contacting surfaces of two physically independent, separate bodies or substrates. The basis amide of the substrates may be alike or different and synthetic (polyamide-6, polyamide-12) or natural (protein, polypeptide). The polyamide bodies are coated (wetted) with a methoxy-methylating solution of paraformaldehyde in methanol (paraformaldehyde:methanol from 0.1:1 to 1:5 to which traces of KOH are added); they are then pressed together (pressure of 0.05 to 5 MPa) in order to achieve a good contact between the surfaces and the solution. This operation is carried out at a temperature of 5 to 40° C. for 30 minutes to 36 hours. A measurable effect can be observed even after 30 minutes while after 36 hours weld is so strong that in a shear test the material breaks outside the welded area. The advantages of the method according to the invention are as follows. Unlike the known methods, welding is not a mechanical one since it is based on the formation of a chemical bond and for this reason, it is very strong. The method does not require energy consumption since it can be carried out even without heating. An additional advantage is based on this fact: in the case of lamination of oriented foils, they preserve their oriented state and in all cases the polymer does not undergo any unfavorable changes caused by heating. Moreover, by using thin polyamide foils the formation of methylene bridges (crosslinking) takes place in the entire volume of the obtained laminate, regardless of its thickness. The proposed method is convenient and simple, it does not require expensive bonding compounds, it lacks a second material. Last but not least, an important advantage of the proposed method consists in the possibility of welding two, three or more physically different bodies even if they differ in their chemical nature, e.g., synthetic polyamides like polyamide-6, polyamide-12, etc., as well as natural proteins, e.g., animal membranes and polypeptides. The sole condition for the formation of a chemical bond according to the method of the present invention is the presence of amide groups (--CO--NH--) in the polymer macromolecule. EXAMPLE Oriented or isotropic polyamide foils (sheets) are coated (wetted) uniformly with a methoxy-methylating solution prepared as follows. Paraformaldehyde (75 g), and potassium hydroxide, (0.1 g) are added to 75 g of methanol. The mixture is heated at 60° C. until it gives a clear liquid. 6 g of anhydrous oxalic acid is then added as the catalyst of the reaction. Foils coated with the above mixture are pressed in a drill press vise and are stored there for 36 hours at a temperature of 30° C. Having described our invention,

Polyamide bodies, e.g., foils or sheets, are welding together or laminated by forming methylene bridges between nitrogen atoms in the separate bodies by pressing them together in the presence of a alkaline paraformaldehyde/methanol solution containing a catalytic amount of oxalic acid.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a portable electronic scale of minimal thickness and weight which can be easily carried in a bag, stored in a cabinet or hung on a wall, for measuring the weight of persons or objects. 2. Description of the Prior Art Most small scales, such as those used for personal weight measurement, require that the person stand or the object be placed on a flat and rigid load-bearing plate, which rests on a set of levers touching the plate from below at a number of discrete points. The levers rest on a second load-bearing plate which is, in turn, placed on a flat floor. The levers are connected in such manner that when a load is placed on the top plate, the levers exert a load at a single point which is equal to the total load on the top plate. This load is then measured, either by balancing it against a known load as in the scales commonly found in clinics, or by applying that load to a mechanically deformable element, such as a spring or a beam, and measuring the deformation. Common "portable" bathroom scales usually measure the movement of a spring by rotating a dial. Newer scales measure the deformation of a spring or an alternative mechanically-deformable element electronically, with strain gauges or capacitors, and display the measure digitally, usually with a light-emitting diode (LED). The lever mechanisms, the two (or more) load-bearing plates and the power requirements for the LED's usually impose discrete weight and thickness requirements on most known scales, making them too heavy and too bulky to be easily transported from place to place. The smallest scales for personal weight measurement, for example, weigh several pounds and are about one to three inches in thickness. This makes it difficult for them to be carried so that an individual can watch his or her weight while away from home. It also makes it difficult to lift the scales and store them in a cabinet or hang them on a wall when floor space (such as in a bathroom) is limited. A different principle for constructing a scale which does not require any lever mechanism for the mechanical transfer of loads for measurement at a single point has been in operation in some industrial scales for some time. It involves placing a rigid plate on a plurality of mechanically deformable elements, connecting force transducers such as strain gauges to these elements and summing up the electrical signals from these transducers in a Wheatstone bridge balancing circuit to obtain a measure proportional to the total load on the plate. Because the load on the plate is the sum of all the loads on the elements, this measure is the same regardless of the distribution of the load on the plate. Ostrelich U.S. Pat. No. 4,355,692 cites several U.S. patents for industrial scales operating on this principle, namely U.S. Pat. Nos. 4,150,729; 3,949,822; 3,966,003; and 4,146,100. Ostrelich then describes an application of this principle to a small scale for weighing persons, proposing to reduce the cost of manufacturing by replacing the more-common strain gauge transducers with a thick film resistor. He describes a weighing scale in which a load impressed on a plurality of spaced individual transducers is electrically added to indicate a total weight of the load. While not claiming that application of this principle for small scales for weighing persons is new, he does state that the application of the thick film resistors makes it possible to produce a scale of a very limited vertical dimension. The embodiments described by Ostrelich, however, impose discrete thickness as well as weight requirements on the scale incorporating the same. While the film resistors themselves, like strain gauges, are less than 0.01" in thickness, there are a number of other mechanical and electrical components with discrete thickness and weight requirements that are required for the scale. In the embodiments described by Ostrelich, each transducer is mounted on a load-bearing base plate, and placed under pressure by means of a pair of pins separating the base plate from a loading plate and a spaced load-bearing cover plate, which bear the applied load and transmit it to the transducers. The three spaced load-bearing plates, and the intermediate force-transmitting pins, impose discrete thickness and weight requirements on the scale incorporating the same. The Ostrelich device additionally incorporates a fairly large battery cell for powering the electronic circuit and the LED, further increasing the thickness of the scale assembly. Similar thickness and weight requirements are encountered with the small scales disclosed in Curchod U.S. Pat. No. 4,174,760; Schaenen U.S. Pat. No. 4,043,413; Hags U.S. Pat. No. 2,910,287; and Paddon et al. U.S. Pat. No. 4,363,368, for example. These discrete thickness and weight requirements have been found in all known industrial, medical and personal scales produced to-date, thus making it difficult to transport them in bags while travelling, to lift them for a closer look, to store them in a cabinet or to hang them on the wall so as to keep them away from the floor. Even though many scales are advertised as being "portable", they are rarely small or light enough to be easily moved. For a scale to be truly portable, it should be considerably thinner and lighter than scales produced to date, e.g. 1/4" or less in thickness and 1 lb. or less in weight. SUMMARY OF THE INVENTION The weight and thickness requirements for truly portable and at the same time accurate scale are achieved in the present invention, overcoming the disadvantages of the prior art. The scale of the present invention is lightweight, portable and of a very low profile, comprising: (a) a single rigid load-bearing composite plate having substantially flat upper and lower surfaces, the composite plate being of suitable size and strength to support the weight of a person standing or object placed thereon; (b) a plurality of supporting feet upon which the load-bearing composite plate is mounted, the feet being spaced across the under-surface of the composite plate to support a load placed on the top surface thereof; (c) a plurality of thin transducers containing mechanically deformable elements and means for translating the deformations into electrical signals, aligned with and mechanically linked to the respective supporting feet and free to deform when subject to a force exerted by the feet from below; and (d) electronic means of low power consumption and low vertical profile for powering the transducers and for summing their signal outputs and providing a read-out thereof, housed within the composite plate. The transducers and electronic means are contained within the composite plate so as not to reduce its rigidity or increase its thickness. The scale of the present invention provides accurate weight measurements and is thin and light enough to be easily transported by an individual, even within a small briefcase or bag. The composite plate is made up of two or more layers rigidly bonded to one another in a sandwich construction, making it possible to concentrate the compressive and tensile strength of the plate on its top and bottom surfaces. In one embodiment described herein, an intermediate layer (center core plate) is provided between the top and bottom layers. This center core plate acts mainly in shear with minimal need for high tensile or compressive strength, and can then be made of a material or structure of very light weight. While the top and bottom layers require heavier material for strength, they may nevertheless be extremely thin and therefore light in weight as well. The sandwich construction of the composite plate allows the layers to act structurally as a single rigid plate of minimal weight and thickness. In addition, the rigidity of the assembly makes it possible to raise it above the floor with a plurality of shallow feet located near the periphery of the plate, without causing the plate to touch the floor due to deflection caused by loading. The feet thus add only a minimal thickness (e.g., 0.2") to the scale as a whole. The load exerted downwards on the plate produces an equal and opposite force exerted upwards by the plurality of feet on the transducers. This permits the shallow feet themselves, which are needed to raise the plate above the floor in any case, to be used as an integral part of the load-measuring mechanism, and eliminates the need for separate force-transmitting pins or other load carrying members to act on independent transducer means, thus further reducing the required thickness of the scale. Measuring the upward loads exerted by the feet on the transducers embedded in the composite plate also eliminates the need for the multiple, separate plate structures proposed by Ostrelich, where a number of individual plates are needed--two to bear the load and one to house the transducers. In accordance with a further feature of the invention, the electronic means for summing the signal outputs of the several transducers comprises: (i) signal generating means for supplying a signal to each force transducer; (ii) means suitable for connecting a power source to the signal generating means; (iii) a Wheatstone bridge configuration of the transducers; (iv) an analog amplifier connected to output of the Wheatstone bridge for amplifying the output thereof; (v) an analog-to-digital converter connected to the output of the amplifier; (vi) a display driver and display connected to the output of the analog-to-digital converter; and (vii) switch means for enabling power to flow to the circuit; the electronic means operating to provide a display of weight information which corresponds to the cumulative signal outputs of the transducers. It is possible to employ a wide variety of thin force transducers or load cells in the present configuration. They may include a number of beam configurations with strain gauges bonded onto them; diaphragm-type transducers with strain gauge bonded onto them; capacitance-type transducers; piezo-electric crystals; diaphragms compressing a confined mass of carbon; or the thick film resistors proposed by Ostrelich. The force transducers incorporated in a preferred embodiment of the present invention comprise: (i) mechanically deformable beams which are free to deflect upwards in response to a force exerted by the feet from below when the composite plate is loaded from above, the beams being defined by slots cut into a thin disc or other member bonded onto the composite plate; and (ii) strain gauge means comprising at least one strain gauge bonded to each beam and positioned so as to provide a signal output directly proportional to the deflection of the beam and to the load on the beam. The circuitry which powers the transducers has a very batteries, such as lithium "coin"-type b tteries commonly found in electronic calculators and the like. The scale of the present invention features, yet the entire composite plate is only one-quarter inch or less in thickness, the feet are less than 0.2" in height, and the entire embodiment weighs less than one pound. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a embodiment of the electronic personal scale of minimal thickness and weight of the present invention; FIG. 2 is an end elevation view of the scale of FIG. 1; FIG. 2B is a bottom plan view of the scale of FIG. 1; FIG. 3 is an exploded isometric of the scale of FIG. 1 showing a three-layer composite plate; FIG. 4A is an enlarged, partial vertical section through the scale of the present invention with a three-layer composite plate, taken along line 4--4 of FIG. 2B; FIG. 4B is a top plan view of the transducer assembly of FIG. 4A; FIG. 4C is a cut-away isometric view of the transducer assembly of FIG. 4A; FIG. 4D is a cut-away isometric view of the transducer assembly of an alternative embodiment with a two-layer composite plate; and FIG. 5 is a schematic diagram showing the electronic components of the scale of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIGS. 1, 2A, 2B and 3, there are shown overall views of a preferred embodiment of the low-profile electronic personal scale of minimal thickness and weight of the present invention. As best illustrated in FIG. 3, the scale housing comprises a load-bearing composite plate of extremely thin layers or plates in a sandwich-type construction. The layers of this construction comprise a top plate 11, a center core plate 12 and a bottom plate 13. The layers are normally hidden from view by a marginal edge strip 14 placed around the periphery of the assembly. The marginal edge strip may be of plastic, rubber or other shock-absorbing material and is attached to the outside periphery of the plates 11, 12, 13 for protection and waterproofing. Alternatively, top plate 11 could be constructed so as to extend down over center core plate 12 and bottom plate 13, to form a continuous smooth surface without the need for edge 14, to protect the layers of the composite plate. There are several variations possible in constructing the composite plate so as to keep it thin and light and yet sufficiently strong to carry a load, such as a heavy person, without deflecting appreciably. In addition to the three-layer sandwich plate discussed in detail and shown in FIG. 3, it is possible to construct the composite plate from two bonded plates in sandwich construction as shown in FIG. 4D, in particular, (i) an upper plate made of moulded light-weight material of high elastic modulus with a substantially flat top and a set of cavities below formed by an arrangement of shallow ribs; and (ii) a bottom plate similar to that shown in FIG. 3. In FIG. 3, the plates are roughly rectangular in shape in the preferred embodiment, although oval, trapezoidal or any other configurations may alternatively be employed. These may have flat plates of a variety of sizes, depending on the size and shape of the objects to be measured. Among other forms of roughly rectangular shapes, it is possible to construct scales with the principles embodied here that are half the size of a plate needed to stand on with both legs. Such a half-size scale may be used for weighing a person standing on one leg. Furthermore, it is possible to construct scales which fold into two with different size plates (including the half-sized plate for standing on one leg) and with a different number and arrangement of feet to ensure stability and to prevent the scale from touching the floor near the hinge area. The feet in the folding versions can fit into cavities in the plate so as not to protrude from the scale when it is folded. Such folding scales may be more convenient for use in travelling. Top plate 11, which is preferably of steel, aluminum, or other rigid metal, plastic or like material of high elastic modulus and high tensile and compressive strength, defines a surface which is rigid enough and large enough to permit an adult to place both feet on the scale for weighing. Bottom plate 13 is preferably of a material of similar structural properties acting in tension when the composite plate is loaded from above. Bottom plate 13 also provides a housing for the transducers and protects the internal mechanical and electrical measuring components from below. The center core plate 12 is preferably made from very light-weight, rigid material (e.g., polyurethane foam) or a grid or honeycomb arrangement of a heavier material, but overall light in weight, acting in shear when the composite plate is loaded from above, and defining various cavities for housing the transducers and the electronic components of the scale. The three layers of the composite plate preferably are bonded together with adhesive, although they may be riveted, screwed or otherwise attached to one another. The top and center plate may also be made of the same material and moulded into one single entity as shown in FIG. 4D. The several layers of the assembly thus act structurally as a single load-bearing plate. Referring now to FIGS. 1 and 3, top plate 11 may contain over a substantial portion of its surface a coating 15 of non-slippery material warm to the touch, such as rubber, roughened plastic or other non-metallic material to provide adhesion for safety and a non-metallic surface for warmth. A liquid crystal display (LCD) 16 provides a visible read-out of the weight on the scale. Display 16, shown through opening 17, is preferably covered with a transparent display cover 18 for protection and waterproofing. As best shown in FIGS. 2A, 2B, 3, 4A, 4C, and 4D, a plurality of supporting feet 19 are provided, attached to the bottom plate 13. The supporting feet are spaced across the under-surface of bottom plate 10, preferably positioned near the corners thereof. The feet need not extend more than 0.2" from bottom plate 13. Feet 19, in addition to keeping the composite plate above the floor to prevent it from getting wet, also perform important load-transferring and weighing functions in the present invention. A silicone or other seal 22 (see FIG. 4A) provides waterproofing. The feet 19 have a spherical bottom but many other shapes of feet which touch the floor at a point below the center of the transducer beams 24 (described below) are possible. It is also possible to use hard rubber or plastic on the bottom of the feet without adding to their overall height so as not to scratch the floor. It is further possible to add height to the feet with separate components which fit under them or replace the feet with higher feet when the scale is to be used on a thick carpet. Directly above each supporting foot 19 is a transducer or load cell assembly 21. The transducer assemblies 21, which are best seen in FIGS. 3, 4A, 4B, 4C, and 4D, perform the actual mechanical weight measurement functions of the present invention. In an improvement over the prior art, the transducer assemblies are mechanically linked directly to the respective supporting feet 19 aligned therewith. In the preferred embodiment, each transducer assembly 21 comprises a transducer body 23 having a transducer beam 24, defined therein by slots 25. Transducer body 23 preferably is a shallow conical or cylindrical structure made of metal, composite material or other material of high elastic modulus (e.g. steel), and having substantially flat top and bottom surfaces and a horizontal lip 26. In the preferred embodiment, slots 25 are cut all the way through transducer body 23 and are substantially parallel to each other, although this is not required. There are many possible configurations of slots which may define a single beam, a pair of cross beams, or several beams in the shape of a star. It is also possible to construct a transducer body 23 without any slots at all acting as a thin diaphragm where the supporting foot 19 is bonded to the center of the diaphragm from below. As shown in FIG. 4B, slots 25 are also slightly enlarged at each end to establish areas of stress concentration at the ends of the beam. Further, the aligned supporting foot 19 is directly linked to transducer beam 24, thus providing a simplified, extremely thin scale construction. Each transducer assembly 21 fits within indentations 13a in bottom plate 13 (FIGS. 3 and 4A). The lip 26 of each transducer body 23 extends slightly under bottom plate 13 to hold the assembly in position. Transducer assemblies 21 may be manufactured and calibrated separately and then soldered or otherwise bonded into place in final assembly. The arrangement provides a very compact assembly for the transfer of force to the transducers for measurement. Directly above each transducer beam 24, and attached thereto, are resistive strain gauges 28 and 29. The center strain gauge 28 and the edge strain gauge 29 are each attached at points of maximum strain on the beam. The center strain gauge is at a point of maximum tensile strain, and the edge strain gauge, which straddles the "joint" between the bendable transducer beam 2 and the fixed portion of transducer body 23, is at the point of maximum compressive strain. In this way, strain gauges 28, 29 can measure the strain in transducer beam 24, which is directly proportional to the load exerted by the foot on the beam. In the preferred embodiment illustrated, two strain gauges are provided for each transducer assembly. Each gauge has two electrical leads for attachment to electronic circuitry (described below) for measurement of the load on the beam. As best seen in FIG. 3, immediately above the bottom plate containing the transducer assemblies is the center core plate 12. Center core plate 12 defines various varieties for housing various components of the invention. Shown, for example, are cavities 35 for indentations 13a formed in bottom plate 13 for the transducer assemblies 21; cavities 36 for batteries 37; cavity 38 for the LCD 16; a partial cavity 39 for a printed circuit board (PCB) 40; a cavity 41 for an integrated circuit 42; and other cavities 43 for other electronic components contained on PCB 40, which electronic components are shown generally as items 44. The PCB 40 containing electronic components 42, 44 and LCD 16 fits within cavity 39. In the preferred embodiment, all the electronic components are soldered or otherwise electrically connected to a PCB with an extremely thin vertical dimension (e.g., less than 0.030"). It is possible, furthermore, to surface mount all the components onto the PCB so as to eliminate the solder beads below the PCB and to further reduce the overall vertical dimension of the electronic assembly. PCB 40 may be electrically connected to removable batteries 37 via wires 49, which wires may be copper bonded to plastic to form thin ribbons to permit thinness of construction of the scale. Batteries 37 may, for example, comprise lithium coin type batteries, which are extremely thin, yet provide sufficient power to power the components for a period of one to two years, depending on the frequency of use of the scale. Alternatively, it is possible to use card-shaped batteries with an even thinner vertical dimension. The ends of wires 49 are also connected to the leads (not shown) of the strain gauges PCB 40 with its accompanying wires may be bonded into the cavities in center core plate 12 with adhesive or the like so as to form a relatively solid construction, to withstand shaking which may occur if the scale is transported and to increase the rigidity of the composite plate. Covering the undersurface of PCB 40, wires 49 and batteries 37 is bottom plate 13 (see FIG. 3). The bottom plate contains an opening 45 for removal of the batteries 37. The battery compartment is covered from below with waterproof battery compartment cover 48 on the underside of the bottom plate. Cover 48 may be screw-in, snap-in or slidably mounted. It is also possible to have an additional cavity and cover over all or part of the printed circuit board to make it possible to dismantle and repair it. Alternatively, it is possible to house the batteries and the printed circuit board, including the electronic components, in thin plastic compartments which may be slid into the composite plate from the top and bottom edges of the plate, rather than from below. As shown in FIG. 2B, small hanging hole 20 is provided at the top end of the bottom plate to make it possible to hang the scale on the wall. The mechanical operation of weight measurement may now be described. Referring to FIGS. 4A, 4B, 4C, and 4D, as weight presses down on the top plate 11, the load is transmitted through the transducer assemblies 21 to the supporting feet 19. A force equal and opposite to the weight is the transmitted by feet 19 upwards to the transducer beams 24. This causes each transducer beam 24 to deflect upwards. When the weight is removed, transducer beam 24, which is of high modulus of elasticity, returns to its original flat position flush with the upper surface of transducer body 23. The total force exerted upwards by the supporting feet, even if the weight is unevenly distributed on the top of the composite plate, must be equal to the weight pressing down from above. To know the value of this weight, one must know the value of the upward forces exerted on the four beams 24. These forces create strains at the center and at the edge of the beams which are proportional to the force exerted at its center vertically from below. The upward deflection of the transducer beams 24 places the center strain gauges 28 in tension and the edge strain gauges 29 in compression, as the strain gauges are similarly deflected upward. This causes the electrical resistance of the strain gauges to vary, varying any voltage differential which may be applied to the gauges in direct proportion to the strain in the strain gauges and thus modulating any electrical current which may be flowing through the gauges. Since the strain gauges are of the same type, they produce similar voltage differentials but of opposite signs. These can be added to produce approximately double the voltage differential of one strain gauge, thus doubling the sensitivity of each transducer. Having two gauge emitting signals of opposite signs also cancels any temperature effects on the strain gauges, and thus provides a distinct advantage over prior art scales, such as that disclosed by Ostrelich, which require thermal insulation. Turning now to the electronic circuitry of the present invention, FIG. 5 shows schematically the arrangement of components for converting signal outputs from the several strain gauges 28 29 into a digital read-out of the weight on the scale. In electrical operation, the strain gauges are arranged in a Wheatstone bridge configuration, so that the voltage differentials of all the strain gauges together may be summed up, the sum being proportional to the total weight on the top plate 11. This total voltage differential results in an analog signal that is fed into an integrated circuit (IC) 42, which converts it into a digital signal for driving LCD display 16. The total voltage differential may be scaled up or down as desired s that the digits of the display actually correspond to the weight expressed in pounds or kilograms, as required. In FIG. 5, the center strain gauges 28 are shown schematically as resistors 50-53 and edge strain gauges 29 are shown schematically as resistors 54-57, connected in parallel in two bridges, which electrically act as a single bridge. Each strain gauge may, for example, have a resistance of 350 ohms. For a given load on the composite plate, the total resistance at the output of the Wheatstone bridge is constant regardless of changes in the resistance of the individual strain gauges, thus permitting constant and accurate read-out of the weight despite uneven placement of weight on the scale. A high-resistance parallel circuit (resistors 57-60) is used for zero-balance in order to cancel bridge component mismatch at zero applied load. Opposite legs of the bridge are connected to the strain gauges 29 which are placed in compression (decreasing resistance), and to gauges 28, which are placed in tension (increasing resistance), respectively, in order to give the highest sensitivity when a load is applied. The bridge is energized with a regulated 1.2 volt power supply (such as provided by batteries 37) in order to maintain a calibrated output throughout the life of the batteries. Batteries 37 may be of the 3 volt, 250 mah type. The signal at the output of the Wheatstone bridge is amplified by amplifier 61, filtered, and then converted to digital form by an analog-to-digital (A/D) converter contained within integrated circuit 42. Integrated circuit 42 is connected to LCD display 16, and also provides a driving function for the display. Conventional switch 86 is a momentary "on" switch for permitting power to flow to the circuitry when one is ready to use the scale. It may, for example, comprise a membrane switch to minimize the thickness of the construction. The difference voltage signal at the output of the Wheatstone bridge is calibrated so a to display 10 microvolts/pound. Amplifier 61 may, for example, comprise an LM363D precision instrumentation amplifier, which is connected so as to have a fixed gain of 100, and an extremely low offset voltage drift. A filter network (elements 63-70), is placed at the input of amplifier 61 in order to eliminate electrical noise. An offset voltage adjustment network (elements 71-75) compensates for any output due to this effect. A gain control potentiometer 76 acts as a span calibration and can be used to calibrate the scale in pounds or kilograms. The voltage is then fed, through another filter network (elements 77-85) into IC 42, which includes a 41/2 digit, single-chip A/D converter (ICL7129), which converts the input voltage into a value for LCD 16 with better than 0.05% accuracy. Integrated circuit 42 also contains the driver circuitry necessary to operate display 16. The external voltage reference diode 87 (ICL8069) and associated elements 88-90 are used to energize the bridge and IC with regulated power from batteries 37. In the preferred embodiment, display 16 is of the LCD type which requires minimal operating current. It may be of triplex design which permits three elements to be energized per control line from IC 42. Resistor 60 may be used for zero adjust. Resistor 76 be used for span adjust (i.e., may be adjusted to denote different units of weight measurement, such as pounds or kilograms). Components 91-96 complete the circuit. The entire circuit draws less than 5 milliamperes of current from the batteries during operation. Nominal values for the electronic components in the preferred embodiment are as follows: ______________________________________FIG. 5Element No. Nominal Value______________________________________37 DL2430, 3 V, 250 mah42 ICL712950-57 350 ohm57 10K ohm, 1/4 W58 10K ohm, 1/4 W59 10K ohm, 1/4 W60 10K ohm61 LF363D or LM363D62 10 uF63 150 ohm, 1/4 W64 150 ohm, 1/4 W65 1 MEG, 1/4 W66 10K ohm, 1/4 W67 10K ohm, 1/4 W68 1 MEG, 1/4 W69 0.01 uF70 0.01 uF71 47K ohm, 1/4 W72 50 ohm, 1/4 W73 10K ohm, 1/4 W74 10K ohm75 47K ohm, 1/4 W76 10K ohm77 0.01 uF78 0.1 uF79 1 MEG, 1/4 W80 1 MEG, 1/4 W81 0.1 uF82 1.2K, 1/4 W83 560 pF84 0.1 uF85 150K, 1/4 W86 Momentary On Switch87 ICL8069 or ICL809688 6.8 uF89 1K, 1/4 W90 10K ohm91 1.0 uF92 270K, 1/4 W93 10 pF94 5 pF95 12K, 1/4 W96 6.8 uF______________________________________ The electronic circuit thus described operates to sum the signal outputs of the strain gauges to yield a signal proportional to the total weight on the composite plate, which signal is then simplified and digitized to drive display device to give a numerical read-out of the weight. The electronic circuitry described above is the preferred configuration for operating the scale of the present invention. There are a number of additional electronic features which may be incorporated into the scale without requiring a physical modification or a change in the scale's mode of operation. These include additional circuits for automatic zero-adjust; for locking the display on for a few seconds after a person steps down or the object is removed to enable the person to pick up the scale and look at the display at a closer distance; for switching the scale on automatically when a person touches it or steps on it; or for weighing something while a person is holding it (e.g. a suitcase) by zeroing out their individual weights first (e.g. weighing the items separately first, pushing a bottom and then weighing them again holding the object). Similarly, it is possible, for example, to light the display from below with an electro-luminescent film or other light-producing element which consumes a small amount of electrical current so that it may be read easily in a darker room. It is also possible to separate the display and the electronic controls from the composite plate in a separate compartment, connected to the plate by wire or by remote control. It will be apparent that many other modifications and variations may be effected without departing from the scope of the novel concepts of this invention, as defined in the claims appended hereto:

A portable electronic scale of minimal thickness and weight is provided which is suitable for measuring the weight of an individual or object and which can be easily carried in a bag, stored in a cabinet or hung on a wall. The scale comprises a single load-bearing composite plate of composite (sandwich) construction with its principle strength concentrated on its top and bottom surfaces, and including a center core plate which includes a number of small cavities for electronic components. A plurality of shallow supporting feet exert a force from below on a plurality of mechanically deformable elements embedded rigidly in the composite plate, which force is measured and translated by electronic transducers such as strain gauges into electrical signals. These signals are summed in a Wheatstone bridge configuration, amplified and converted electronically to a digital display of the weight. The electronic circuitry fits within the composite plate and consumes very small amounts of current when in use so that the need for a thick battery is eliminated. The scale (excluding the shallow feet) is less than 1/4" in thickness and weighs less than one pound.

BACKGROUND [0001] In drilling and completion industries such as hydrocarbon exploration and production, Carbon Dioxide sequestration, etc., tools are often run into the downhole environment for particular purposes requiring locating the tool at a target position. Traditionally an operator will keep track of a length of tubing in the hole and anticipate the specific tool at issue locating upon a feature within the hole. The feature may be a seat, profile, bottom, etc. Such “gauging” of where the tool is occurs in trips into the borehole, trips out of the borehole and movements of the tool in defined areas of the borehole. [0002] For example, an operation in a borehole may require several actions taking place between a downhole most location and an uphole most location for the particular operation. Providing profiles at these locations will provide a guide to the operator to keep the target tool in the target location for the job being done. [0003] While such measures are currently used, tools do not always engage profile properly and effective indication of position at the surface may not be received. Such situations result in lost time, which translates to cost increases. [0004] In order to address the foregoing, a downhole position locating device with fluid metering feature (U.S. Pat. No. 7,284,606, the entirety of which is incorporated herein by reference) was developed. Such a tool or others that function by providing a fluid movement component of their operation, which fluid component has an effect on tool operation such as in the ‘606 patent wherein the fluid delays an action until the fluid is removed by exhaustion or by movement to another chamber are useful as landing in a sought profile is better verifiable by a pull or push from surface that allows for a slower movement of the string. While the concept generally works well, there is a possibility that the tool experiences restricted movement due to friction, Blow Out Preventer (BOP) contact or other impediments rather than due to an engagement with a profile and fluid movement. In such case, the indication of tool location at surface would be inaccurate. Since accuracy in downhole operations improves efficiency and reduces costs, the industry will well receive improved arrangements supporting these goals. SUMMARY [0005] A downhole tool with a feedback arrangement including a tool having one or more fluid outflow ports that exhaust fluid during normal operation of the tool; and a feedback arrangement in operable communication with the fluid exhausted from the one or more fluid outflow ports during operation of the tool, the feedback arrangement interacting with exhausting fluid to produce a signal receivable at a remote location indicative of proper tool operation. [0006] A method for confirming operation of a downhole tool including disposing an oscillator within a fluid outflow path; actuating the tool thereby causing fluid to flow in the outflow path; affecting the oscillator with the fluid; and creating a signal with the oscillator representative of tool operation. BRIEF DESCRIPTION OF THE DRAWINGS [0007] Referring now to the drawings wherein like elements are numbered alike in the several Figures: [0008] FIGS. 1A-C is a representation of one embodiment of a metering tool with feedback arrangement in three distinct positions; [0009] FIGS. 2A-C is a representation of another embodiment of a metering tool with feedback arrangement in three distinct positions; and [0010] FIG. 3 is a plan view of an embodiment of a pulser. DETAILED DESCRIPTION [0011] It is to be appreciated that while the overall configuration of the metering tool of the ‘606 patent is utilized to illustrate two embodiments of the disclosed invention, other configurations where fluid movement is a part of the function of the tool will also benefit from the embodiments providing feedback as described herein. [0012] Referring to FIGS. 1A-C , a metering tool 10 is generally depicted with a feedback arrangement including an oscillator 12 . In this embodiment the oscillator is a spring mass that is positioned within a fluid outflow through outflow port(s) 14 caused by metering of the metering tool 10 . It is to be understood that although a spring mass is illustrated as oscillator 12 , any mass that can be caused to oscillate due to fluid flow can be used. As will be appreciated from a review of the metering tool in the incorporated by reference ‘606 patent, fluid is exhausted during the normal operation of the tool 10 . Because of the placement of the oscillator 12 , the fluid flow through outflow port(s) 14 interacts with the oscillator to cause the oscillator to oscillate. Oscillation of the oscillator produces a signal that can be received at remote locations and is indicative of proper tool operation. Different forms of oscillation can be transmitted to remote locations for reliable feedback of the operation of the tool. In this case, the spring mass, which may be a coil spring as shown, oscillates against the tool itself creating vibration that is transmitted through a string 16 supporting the tool back to surface or other remote location. The vibration is detectable at the remote location by hand or sensor or auditorily and confirms proper operation of the tool in the downhole environment. [0013] In another embodiment, referring to FIGS. 2A-C , a metering tool 10 with a feedback arrangement includes a pulser 20 mounted proximate a fluid outflow through the outflow port(s) 14 of the tool 10 . Upon fluid outflow, the pulser arrangement will rotate. The pulser, in one embodiment is hence a rotating member. Rotation of the pulser is due to one or more (four shown) openings 22 in the pulser 20 that are configured angularly relative to an axis of the rotatable pulser. Rotation of the pulser 20 results in an alternating pattern of openings and solid sections of the pulser aligning with the fluid outflow of the tool 10 . This alternatingly allows fluid passage and fluid blockage (or at least inhibition). Accordingly, pressure within the fluid downstream of the pulser changes alternatingly at the same rate that the pulser rotates. Pressure downstream of the pulser decreases when fluid flow is inhibited and returns to system pressure with each alignment of the openings 22 . More particularly, when one of the openings (or more of them if there are more fluid outflow ports or if the pulser is configured to align more than one of the openings with the fluid outflow (in the event that the fluid outflow is broader in area than one of the openings 22 plus an adjacent solid portion of the pulser 20 ) is aligned with the fluid outflow, the pressure downstream of the pulser is the same as it is upstream of the pulser. When the pulser rotates to a position where the fluid flow from the outflow port(s) is blocked or inhibited, the pressure in the fluid downstream of the pulser dips. The dip in pressure and subsequent recovery of system pressure can be received and in some cases might actually be measured a substantial distance from the pulser 20 and tool 10 . The pressure change is embodied as an acoustic signal propagating through fluid in the borehole and provides feedback at a remote location or at the surface of fluid outflow from the outflow port(s). Depending upon the length of time a particular tool has a fluid outflow, the acoustic signal may have time to reach a remote location such as the surface to be perceived or the signal may act as a post actuation confirmatory signal. This is because an appreciable amount time is required for signal propagation in a fluid medium. And while clearly the time factor for signal propagation in a fluid medium is directly related to the density of that fluid, (and of course distance is a factor in overall travel time) in virtually all cases of fluid borne acoustic signals from downhole tools, it will be likely that the actuation time causing the fluid outflow will be less than the transit time for the signal hence making such signals confirmatory. [0014] While the foregoing embodiment provides one method for propagating a signal based upon the structure shown, there is another that provides for much less of a time delay. This utilizes the actual work string the tool is disposed in to propagate a vibratory signal. Because the pulser, in addition to what it does as noted above, will also cause pressure variations in the tool that is exhausting fluid, the string itself experiences varying strain that is cyclic. A cyclic change in tensile strain can function as a signal. More specifically, and using the metering tool of the ‘606 patent as an example, as the tool contacts a locating profile, applied tension displaces fluid through the outflow ports and past the pulser. The flow of fluid rotates the pulser thereby restricting and unrestricting the flow of liquid through the ports. This variance in restriction results in a variance of the pressure within the tool chamber. The variance in chamber pressure in the tool will be manifested as a variance in force between the metering tool and the profile. This force variation is detectable as a variance in tensile force in the workstring upon which the tool has been run and operated. The signal provides increased confidence that the tool 10 is operating properly. One benefit of this embodiment is the speed at which a signal will propagate through metal as opposed to a fluid. In view of this speed increase, the signal is received virtually contemporaneously with the tool actuation. [0015] While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.

A downhole tool with a feedback arrangement including a tool having one or more fluid outflow ports that exhaust fluid during normal operation of the tool. A feedback arrangement in operable communication with the fluid exhausted from the one or more fluid outflow ports during operation of the tool. The feedback arrangement interacting with exhausting fluid to produce a signal receivable at a remote location indicative of proper tool operation. A method for confirming operation of a downhole tool is included.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the priority of German Application No. 100 53 139.3 filed Oct. 26, 2000, which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] This invention relates to a device in a fiber processing machine, such as a carding machine or a cleaner for setting the distance between cooperating clothings, such as the clothing of the main carding cylinder of a carding machine and the clothing of a flat bar of a traveling flats assembly. [0003] The distance between the clothing of the main carding cylinder and the clothing of a member cooperating therewith is of substantial significance as far as machine technology and fiber technology are concerned. The carding result, that is, the cleaning, nep-formation and fiber shortening is to a large measure dependent from the carding clearance, that is, the distance between the clothing of the main carding cylinder and the clothing of the traveling or stationary flat bars. The guidance of air about the main carding cylinder and the heat removal are also dependent from the distance between the clothing of the main carding cylinder and the facing clothed or even non-clothed surfaces, such as a waste separating mote knife or cover elements of the machine. The extent of the distances depend from different, partially opposed effects. The wear of cooperating clothings leads to an enlargement of the carding clearance which results in an increase of the nep number and a decrease of the fiber shortening. An increase in the carding cylinder rpm, for example to increase the cleaning effect, causes, because of centrifugal forces, an enlargement of the carding cylinder, including its clothing and thus a decrease in the carding clearance results. The carding cylinder also expands and thus the carding clearance decreases because of the temperature increase in case a large quantity of fiber is processed or particular fiber types, for example, chemical fibers are handled. [0004] In practice, during assembly of a carding machine, first the flat bars are installed and then the distance between the clothing points of the carding cylinder clothing and the clothing points of the flat bar clothings is determined by gauges. Such a distance is measured, for example, at every other flat bar, and an average value is formed from the measured values. The flat bars of a flat bar set regularly have different heights so that the distances are accordingly different. For changing the distance between the points of the flat bar clothings and the points of the main carding cylinder clothing, that is, to set a predetermined carding clearance, the position of the flexible bend (carrying the sliding guide for the flat bars) is radially adjusted at several locations by means of set screws. Thus, by changing the position of the sliding guide, the radial position of the flat bars is altered and, as a result, the distance between the clothings of the flat bars and the main carding cylinder is set. [0005] An adjustment of the flexible bends as outlined above is complicated, time-consuming and requires skill and experience. Further, the geometry of the flexible bend depends from the number of the circumferentially distributed set screws. It is a further drawback that the entire flexible bend cannot be adjusted in one step. It is a particular disadvantage that the differences in the height positions of the flat bars are included in the measurements. Because of these height differences and the use of a plurality of circumferentially distributed set screws, the carding clearance cannot be set in a desired manner. [0006] In a known arrangement, as described, for example, in European Patent No. 801 158 a sensor is provided with which the working distance of the carding clothings (also termed as “carding clearance”) can be measured, that is, the effective distance of the points of a clothing from a machine component facing the clothing can be determined. Such a machine component may also have a clothing but may also be, for example, a cover element provided with a guiding surface. The sensor is configured particularly for measuring the working distance between the carding cylinder and the flat bars of a traveling flats assembly. Such a working distance changes as the wear increases. By means of an optical instrument the carding clearance between the carding cylinder clothing and the flat bar clothings is to be sensed from the side of the working region. It is a disadvantage of this arrangement that the change of the carding clearance gives no indication to what extent the change is to be traced back to the different flat bars. SUMMARY OF THE INVENTION [0007] It is an object of the invention to provide an improved device of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, sets the carding clearance in a simple and time-saving manner. [0008] This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fiber processing machine includes a roll having a circumferential surface provided with a first clothing having clothing points; a counter member having a surface provided with a second clothing cooperating with the first clothing and having clothing points; and a device for setting a clearance between the clothing points of the first and second clothings. The device includes an arrangement for approaching the roll and the counter member to one another until the clothing points of the first and second clothings contact and for moving away the roll and the counter member from one another until the clothing points of the first and second clothings assume a desired clearance. The device further has an arrangement for emitting a signal when the clothing points of the first and second clothings contact one another. [0009] The measures according to the invention provide for a very accurate setting of the carding clearance in a simple and time-saving manner. It is a particular advantage of the invention that the setting is carried out without changing the shape of the flexible bend and the sliding guide; as a result, the previously uniformly and precisely set flexible bend and sliding guide retain their shape. It is a further advantage that the setting of a particularly narrow carding clearance is possible. This is of significance since the smaller the carding clearance, the better the carding effect. BRIEF DESCRIPTION OF THE DRAWINGS [0010] [0010]FIG. 1 is a schematic side elevational view of a carding machine incorporating the invention. [0011] [0011]FIG. 2 is a fragmentary side elevational view of a traveling flats assembly. [0012] [0012]FIGS. 3 a , 3 b and 3 c are fragmentary side elevational views of a traveling flats assembly illustrating the displacement of the flat bars before, during and after contact between the clothing of a flat bar and the clothing of the main carding cylinder. [0013] [0013]FIG. 4 a is a schematic side elevational view of a traveling flats assembly, also illustrating the flexible bend and a shiftable slide guide. [0014] [0014]FIG. 4 b is a view similar to FIG. 4 a showing the slide guide shifted in the direction A for radially repositioning the flat bars. [0015] [0015]FIG. 5 is a schematic side elevational view of a device for shifting the slide guide. [0016] [0016]FIGS. 6 and 6 a are schematic views of an embodiment of a device for determining a contact between clothing points. [0017] [0017]FIG. 7 a is a schematic side elevational view of a flexible bend having a series of set screws. [0018] [0018]FIG. 7 b is a sectional view taken along line 7 b - 7 b of FIG. 7 a. [0019] [0019]FIG. 8 is a block diagram of an electronic control and regulating device. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0020] [0020]FIG. 1 illustrates a carding machine CM which may be for example, an EXACTACARD DK 803 model, manufactured by Trützschler GmbH & Co. KG, Mönchengladbach, Germany. The carding machine CM has a feed roller 1 , a feed table 2 cooperating therewith, licker-ins 3 a , 3 b , 3 c , a main carding cylinder 4 having a rotary axis M, a doffer 5 , a stripping roll 6 , crushing rolls 7 , 8 , a web guiding element 9 , a sliver trumpet 10 , calender rolls 11 , 12 , a traveling flats assembly 13 , having flats 14 , a coiler can 15 and a sliver coiler 16 . [0021] Turning to FIGS. 2, 5 and 7 a , a flexible bend 17 is mounted by screws 32 on either side of the carding machine, laterally of the machine frame. The flexible bend 17 is provided with a plurality of set screws 31 . The flexible bend 17 has a convex upper face 17 a and an underside 17 b . The upper face 17 a of the flexible bend 17 supports a slide guide 20 , made, for example, of a low-friction synthetic material. The slide guide 20 has a convex upper surface 20 a and a concave lower surface 20 b . The concave lower surface 20 b lies on the convex upper surface 17 a and may slide thereon as indicated by the arrows A, B. The flat bars 14 have at opposite ends (spaced from one another parallel to the cylinder axis M) a flat bar head 14 a from which extend two steel pins 14 b adapted to glide on the convex upper surface 20 a of the slide guide 20 in the direction of the arrow C. The underface of each flat bar 14 carries a flat bar clothing 18 . The circle circumscribed on the flat bar clothings 18 is designated at 21 . The carding cylinder 4 has along its circumference a cylinder clothing 4 a such as a sawtooth clothing. The circle circumscribed about the cylinder clothing 4 a is designated at 22 . The clearance between the circles 21 and 22 is designated at d and amounts to, for example, 0.20 mm. The clearance between the convex upper surface 20 a of the slide guide 20 and the circle 22 is designated at e. The convex upper surface 20 a has a radius r 1 and the circle 22 has a radius r 2 . The radii r 1 and r 2 intersect in the rotary axis M of the carding cylinder 4 . [0022] [0022]FIGS. 3 a , 3 b and 3 c show, to an exaggerated extent for better understanding, the change of the distances between the clothings 18 of the flat bars 14 and the clothing 4 a of the carding cylinder 4 . [0023] [0023]FIG. 3 a shows the initial position of the flat bars 14 ′, 14 ″, 14 ′″ after their positioning on the upper face 20 a of the slide guide 20 . For manufacturing reasons the respective distances a 1 , b 1 and c 1 are different between the respective clothings 18 a , 18 b and 18 c , on the one hand and the cylinder clothing 4 a , on the other hand. For example, the distance a 1 between the clothing 18 a of the flat bar 14 ′ and the cylinder clothing 4 a is smaller than the distance b 1 (for example, {fraction (1/100)} inch) between the clothing 18 b of the flat bar 14 ″ and the cylinder clothing 4 a , whereas the distance cl between the clothing 18 c of the flat bar 14 ′″ and the cylinder clothing 4 a is greater than the distance b 1 . [0024] According to FIG. 3 b , the flat bars 14 ′, 14 ″ and 14 ′″ are slowly shifted radially to the carding cylinder 4 in the direction D until the points of the clothing 18 a (having the smallest clearance a 1 according to FIG. 3 a ) and the cylinder clothing 4 a are just in contact with one another, that is, the clearance a 2 is zero. Such a minimal contact is harmless even if the carding cylinder 4 rotates. The contact between a flat bar clothing 18 and the cylinder clothing 4 a is sensed by a device 23 as will be described in conjunction with FIGS. 6, 6 a. [0025] Subsequently, as shown in FIG. 3 c , the flat bars 14 ′, 14 ″ and 14 ′″ are shifted radially in the direction E in such a manner that the points of the clothing 18 a of the flat bar 14 ′ and the cylinder clothing 4 a are just separated from one another, that is, a clearance a 3 is obtained. The clearance a 3 should be as small as safely possible, for example, between {fraction (1/1000)} and {fraction (2/1000)} inch. As a result of the above-described manipulation the clearances b 3 and c 3 are as small as possible. A small distance a 3 , b 3 and c 3 , that is, a possibly small carding clearance is desirable for achieving superior carding results. [0026] In FIGS. 4 a and 4 b , shifting of the slide guide 20 on the flexible bend 17 in the direction of the arrow A is shown. Due to the wedge shape of the slide guide 20 , its circumferential displacement, for example, in the direction of the arrow A, will increase the clearance b 1 , b 2 and b 3 between the respective flat clothings 18 a , 18 b and 18 c on the one hand and the cylinder clothing 4 a , on the other hand; that is, the clearance between the circles 21 and 22 (FIG. 2) is increased. Thus, by shifting the slide guide 20 in the direction A, the flat bars 14 are lifted from their position shown in FIG. 4 a in the direction E into the position illustrated in FIG. 4 b . The flat bars 14 are slowly moved between the end roller 13 a and the end roller 13 b of the traveling flats assembly 13 by a non-illustrated belt in the direction C (FIG. 2) and are reversed as they travel on the end roller 13 b to be moved on the idling side of the traveling flats assembly in the rearward direction F. [0027] As shown in FIG. 5, a carrier element 26 affixed to the slide guide 20 is coupled with a toothed rack 27 a engaging a gear 27 b which is rotatable in the directions O, P and which is rotated by a drive, such as a reversible motor 28 . The device can circumferentially shift the slide guide 20 in the direction of the arrow A or B. The drive 28 is coupled with an inputting device 29 with which the desired, smallest carding gap a 3 , for example, {fraction (3/1000)} inch may be set as a desired magnitude. Such a setting may also be performed by an electronic control and regulating device 33 (FIG. 8) which has a desired value memory and/or an inputting device. [0028] As shown in FIG. 6, a device 23 is coupled to the flat bar clothings 18 and the cylinder clothing 4 a in an electric circuit for emitting a signal when the clothing 18 of a flat bar 14 contacts the clothing 4 a of the carding cylinder. Thus, the clothing points of the clothings 4 a and 18 act as electric contacts. The device 23 may be structured such that the clothing 4 a of the cylinder 4 whose bearings are electrically insulated from the frame, is connected with one pole of an electric current source 24 , whereas the other pole is coupled to the machine frame in a non-illustrated manner, so that the flat bars 14 are coupled with that pole of the current source. The electric circuit contains an indicating device 25 which shows whether or not a contact is present between the clothing points. Such a contacting may also be detected by measuring the electric resistance in the circuit, or by an arrangement based on sound detection. Or, as other alternatives of contact-sensing, the acceleration of the traveling flats is sensed or, in case of a stationary carding cylinder 4 , a motion of the carding cylinder as entrained by the contacting traveling flat bar is observed. [0029] Turning to FIG. 7 a , a circumferential groove 30 is provided in the flexible bend 17 . The slide guide 20 which is composed of an elastic, low-friction synthetic material is, as shown in FIG. 7 b , accommodated in the groove 30 such that one part of the slide guide 20 is situated within the groove 30 whereas another part projects beyond the convex upper surface 17 a of the flexible bend 17 . The slide guide 20 is shiftable within the groove in the direction of the arrows A, B so that the concave lower face 20 b slides on the bottom surface 25 a of the groove. The side faces 25 b and 25 c of the groove constitute lateral guides for the slide guide 20 . By means of the set screws 31 first the flexible bend 17 is set, while maintaining its correct shape, to a carding clearance of, for example, {fraction (6/1000)} inch. It is only with the device shown in FIGS. 4 a , 4 b and 5 that the carding clearance may be reduced to such an extent that the flat bar clothing 18 which originally has the smallest distance from the cylinder clothing 4 a , contacts the latter. Subsequently, the carding clearance may be set very accurately to a desired magnitude with the device shown in FIGS. 4 a , 4 b and 5 . [0030] [0030]FIG. 8 illustrates an electronic control and regulating device 33 , such as a microcomputer to which there are connected an inputting device 34 for the desired carding clearance, the drive 28 for rotating the gear 27 b , the device 23 to detect a contact between the flat bar clothing 18 and the cylinder clothing 4 a , the indicating device 25 , the inputting device 29 and a switching element 35 for actuating the drive 28 . [0031] It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

A fiber processing machine includes a roll having a circumferential surface provided with a first clothing having clothing points; a counter member having a surface provided with a second clothing cooperating with the first clothing and having clothing points; and a device for setting a clearance between the clothing points of the first and second clothings. The device includes an arrangement for approaching the roll and the counter member to one another until the clothing points of the first and second clothings contact and for moving away the roll and the counter member from one another until the clothing points of the first and second clothings assume a desired clearance. The device further has an arrangement for emitting a signal when the clothing points of the first and second clothings contact one another.

[0001] This application is related to HT05-013, filed on ______ as application Ser. No. ______ and is herein incorporated, by reference, in its entirety. FIELD OF THE INVENTION [0002] The invention relates to the general field of magnetic tunnel junctions (MTJs) with particular reference to the bottom electrode located between them and the inter-layer dielectric (ILD) of an integrated circuit. BACKGROUND OF THE INVENTION [0003] Magnetoresistive Random Access Memory (MRAM), based on the integration of silicon CMOS with Magnetic Tunnel Junction (MTJ)s, is a major emerging technology, highly competitive with existing semiconductor memories (SRAM, DRAM, Flash etc). The MTJ consists of two ferromagnetic layers separated by a thin dielectric layer. Magnetization of the two ferromagnetic layers can be arranged to be in either parallel (low resistance) or anti-parallel (high resistance) magnetization states, representing “1” and “0” respectively, The MTJ memory cells are usually inserted at the back end of a standard CMOS process. The high-speed version of MRAM architecture consists of a cell with an access transistor and a MTJ (1T1MTJ) in the array. The MTJ element is formed on top of the bottom conductor line, which is used to connect the base of the MTJ to the access transistor. Switching of the free layer magnetization in the MTJ device is accomplished by applying currents to orthogonal conductor lines. [0004] The conductors are arranged in a cross-point architecture that provides the field for selectively switching each bit. One line (bit line) provides the field parallel to the easy axis of the bit, while another line (write word line) provides the perpendicular (hard axis) component of the field. The intersection of the lines generates a peak field that is engineered to be just above the switching threshold of that MTJ. For high performance MTJ devices, the separation between the write word line (bit line) and MTJ free layer is made as small as possible. [0005] In a read operation, the read word line (RWL) is selected, and the transistor is turned on. This causes the MTJ device to be connected to ground. At this time, a sense current passes through the BL-MTJ-BE and to ground. The resistance of the MTJ device is low when the MTJ is storing a 1 and high when it is storing a 0. [0006] Referring now to FIG. 1 a , shown there is tantalum hard mask 15 which will be used to separate MTJ sheet stack 16 into individual devices, each resting on a bottom electrode that comprises material from layer 17 which rests on SiN ILD 11 . Also seen (though not relevant to the invention) are vias 18 . In FIG. 1 b , layer 16 has been patterned into individual MTJ devices 4 , with Ta mask 15 having been partly consumed during the etch operation. In FIG. 1 c bottom electrode layer 17 has also been patterned into individual electrodes. However, in the course of making certain that said electrodes are truly electrically isolated one from another, ILD layer has been over etched so that its top surface has been partly eroded, as symbolized by its being shown as a broken line in the figure. [0007] Reactive ion etching (RIE) has been preferred over IBE (ion beam etching) as the method for etching layer 17 . However, vertical features created by IBE always have an extended slope on the edge, which not only could creates electrical shorting problems but also limits further reduction of line width and make it impossible to make very high density IC device. In general, RIE is considered a better approach to creating well-defined three dimensional micro-features but there are several major problems currently associated with the RIE process: [0000] (I) The uncontrollable over etch mentioned above is due to the lack of etching selectivity between the bottom electrode and the ILD. FIG. 2 illustrates the structure of layer 17 in greater detail—immediately on ILD 11 is TaN layer 12 on which is alpha tantalum layer 13 . Layer 14 comprises a second TaN layer. (2) This etching process always results in a large amount of re-deposition all over the surface of the device due to the non-volatility of the reaction products. (3) The MTJ will experience two etching processes (first in its own etch and then during the BE etch). This not only affects the MTJ's overall dimensions, but also results in serious damage to the edge of the MTJ's tunnel barrier layer. [0008] A routine search of the prior art was performed with the following references of interest being found: U.S. Pat. No. 6,974,708 (Horng et al) discloses OSL on top of the bottom electrode. U.S. Pat. No. 6,703,654 (Horng et al) teaches a NiCr/Ru bottom electrode. U.S. Pat. No. 6,960,48 (Horng et al) discloses a bottom electrode of /NiCr/Ru/α-Ta. U.S. Patent Application 2005/0254293 (Horng et al) teaches layers comprising NiCr/Ru/αTa. U.S. Patent Application 2005/0016957 (Kodaira et al), the Anelva Co., shows dry etching using CH 3 OH. U.S. Patent Application 2006/0002184 (Hong et al) teaches bottom electrodes of NiCr/Ru/Ta or NiCr/Rulα-TaN. Other references, supplied by the inventor, are: 1. S. Tehrani et. al. “Magnetoresistive Random Access Memory using Magnetic tunnel junction” Proceeding of the IEEE. Vol. 91, p703-712, 2003. 2. C. Horng et. al. HTO3-022 “A novel structure/method to fabricate a high performance magnetic tunneling junction MRAM”. Magic touch and NiCr/Ru/alpha-Ta. 3. “Nanoscale MRAM elements” (including an extensive review of RIE), —S. J. Peraton and J. R. Childress (IBM and U of F). SUMMARY OF THE INVENTION [0018] It has been an object of at least one embodiment of the present invention to provide a process for forming a bottom electrode for an MTJ stack on a silicon nitride substrate in such a way as to minimize any possible surface damage to said substrate. [0019] A further object of at least one embodiment of the present invention has been that said substrate also serve as an ILD of an associated integrated circuit and that said ILD have a thickness no greater than about 500 Å thereby facilitating it proximity to a word line of said integrated circuit. [0020] Another object of at least one embodiment of the present invention has been that said bottom electrode have good electrical conductance. [0021] Still another object of at least one embodiment of the present invention has been that said MTJ stack have vertical, or near vertical, sidewalls and be spaced no more than about 0.3 microns from neighboring MTJ stacks. [0022] Yet another object of at least one embodiment of the present invention has been that said process not damage the edges of the tunnel barriers of said MTJ stacks. [0023] These objects have been achieved by including a layer of ruthenium as one of the layers that make up the bottom electrode. The ruthenium serves two purposes. First, it is a good electrical conductor. Second, it responds differently from Ta and TaN to certain etchants that may be used to perform RIE. Specifically, ruthenium etches much more slowly than Ta or TaN when exposed to CF 4 while the reverse is true when CH 3 OH is used. Furthermore, silicon nitride is largely immune to corrosion by CH 3 OH, so removal of a ruthenium layer at, or near, the silicon nitride surface can be safely performed. [0024] This differential etch behavior allows an included layer of ruthenium to be used as an etch stop layer during the etching of Ta and/or TaN while the latter materials may be used to form a hard mask for etching the ruthenium. [0025] A problem of the prior art has been the relatively poor adhesion of ruthenium to silicon nitride. This problem has been overcome by inserting a bilayer of NiCr on TaN as the ‘glue’ between the Ru and the SiN. BRIEF DESCRIPTION OF THE DRAWINGS [0026] FIGS. 1 a - 1 c show the prior art process for forming a bottom electrode for an MTJ stack. [0027] FIG. 2 illustrates the layer structure of an MTJ bottom electrode of the prior art. [0028] FIG. 3 illustrates the layer structure of an MTJ bottom electrode as used in the first embodiment of the present invention. [0029] FIG. 4 shows the structure seen in FIG. 3 after CF 4 etching during which the Ru layer acts as an etch stop. [0030] FIG. 5 shows the structure seen in FIG. 4 after CH 3 OH etching to remove Ru with minimum corrosion of the SiN substrate. [0031] FIG. 6 shows the starting point for the process of the second embodiment of the invention. [0032] FIG. 7 illustrates a key feature of the second embodiment, namely a protective coating that is partly consumed during etching of the alpha tantalum portion of the bottom electrode, [0033] FIG. 8 illustrates the patterning of the protective coating prior to etching down to the level of the ruthenium. [0034] FIGS. 9 and 10 show the final process steps whereby the SiN substrate on which the bottom electrodes lies suffers minimal corrosion after it is exposed and, furthermore, an amount of the protective coating is still present and is thus able to provide permanent protection to the structure. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0035] The invention discloses a novel bottom conductor layer structure that is smooth, flat, and has low resistance. In the first embodiment, the bottom conductor layer structure is NiCr30/Ru20/α-Ta120/TaN150. In the second embodiment, the bottom conductor layer structures is typically TaN/NiCr3/Ru30/α-Ta120/TaN150. The total thickness of these bottom conductor structures is 300 Å (as in the prior art). RIE of these bottom conductor layers is first achieved using an etchant of the CF 4 type to remove the top TaN/Ta layer, which is followed by an etchant of the CH 3 OH type to etch the ruthenium. [0036] In MTJ structures, topological roughness of the magnetic layers causes ferromagnetic coupling (Neel coupling) to shift the hysteresis loop. To minimize this inter-layer coupling effect, it is critical to form the MTJ stack on a flat/smooth bottom conductor. An example of a MTJ configuration that results in a high performance MTJ is: [0000] SiN/TaN/NiCr45/Ru100/Ta150/S.E./NiCr5O/MnPt150/CoFe20/Ru7.5/CoFeB21/AlOx(10-15)/NiFe35/CAP. |<BE<∥<MTJ stack>| where S.E.=sputter etch [0038] It is known that Ta formed on top of Ru grows in its a low resistance alpha-Ta phase. The high performance MTJ is formed on top of NiCr50/Ru100/Ta150 bottom conductor. The disclosed NiCr30/Ru20/Ta100/TaN150 bottom conductor of this invention is very flat and smooth (typically having a roughness value less than about 2 Å). The TaN150 cap is used here to protect Ta from oxidation. For the process to yield a high performance MTJ, this TaN cap is sputter-etched to a 30 Å thickness of the exposed TaN top layer. [0039] When using a photoresist mask, the etching selectivity for Ta (TaN)/Ru by CF 4 -RIE is around 10. Thus in the process of using RIE to pattern the NiCr30/Ru30/Ta100/TaN150 bottom conductor, the top Ta/TaN is subjected to CF 4 gas chemistry which is largely ineffective at the Ru surface. After photoresist strip, the etchant is then changed to CH 3 OH to etch the remaining Ru/NiCr. Ru etch rate is about same as SiN and NiCr etch rate is about 0.5 of SiN. Since the NiCr/Ru seed layer is much thinner than ILD SiN (50 Å vs 300 Å), even with a 100% over-etch of the Ru30/NiCr30 layers, over-etching into the SiN would amount to less than 50 Å. In contrast, for CF 4 -RIE of the TaN501Ta100/TaN150 (as used in the prior art), a 100% over-etch would result in the removal of over 300 Å of the SiN ILD. [0040] For the first embodiment, as an alternative to the use of NiCr as a ‘glue’ layer, a special treatment of the SiN substrate surface may be used instead: [0000] Sputter-clean SiN/OSURu30/α-Ta120/TaN150 [0041] where OSL stands for oxygen surfactant layer. When OSL is used to treat the SiN surface, SiOxyNitride/RuO is formed at the SiN/Ru interface which then promotes good adhesion. [0042] We now provide a description of the processes used to manufacture the two embodiments of the invention: 1 st Embodiment [0043] Referring now to FIG. 3 , the process starts with sputter cleaning of the surface of substrate layer 11 , followed by depositing thereon layer of NiCr 10 onto which is deposited ruthenium layer 31 to a thickness between about 20 and 30 Angstroms. This is followed by the deposition, to a thickness between about 100 and 200 Angstroms, of alpha tantalum layer 32 (on ruthenium layer 31 ). Next, tantalum nitride layer 12 is deposited on layer of alpha tantalum 32 (to a thickness between about 100 and 150 Angstroms). [0044] Now follows a key feature of the invention which is the process used to etch the bottom electrode sheet (layers 12 / 32 / 31 / 11 ) into individual bottom electrodes without, at the same time, significantly penetrating silicon nitride substrate 11 . This is accomplished in two main steps, as follows: [0045] Referring now to FIG. 4 , photoresist mask 41 , that defines the required multiple electrode shapes, is formed on the upper surface of layer 12 . Then, a first reactive ion etching step is performed, using as the etchant one of several possible gaseous compounds of carbon and fluorine, such as CF4, CHF 3 etc., with CF 4 being preferred. Etching of all unprotected areas now proceeds at a rate of about 80 nm/min. and layers 12 , and 32 are successively removed (where there is no photoresist). When however, layer 31 of ruthenium becomes exposed, the etch rate falls off substantially—typically by a factor of about one 10 th , at which point reactive ion etching may be terminated “at leisure” with no danger of etching through ruthenium layer 31 and penetrating silicon nitride substrate 11 . The appearance of the structure is now as shown in FIG. 4 with arrow 42 pointing to the region of separation between two individual bottom electrodes. [0046] Now moving to FIG. 5 , all remaining photoresist has been removed. At this point a second reactive ion etching process is initiated. In this case the etchant used is one of several possible gaseous compounds of carbon, oxygen, and hydrogen, such as CH 3 OH, CO+N H 3 , C 2 H 5 OH, etc., with CH 3 OH being preferred. No additional photoresist is required. Instead the previously etched layer 12 acts as a hard mask during the etching of layers 31 and 10 . Etching of all exposed ruthenium surfaces now proceeds at a rate of about 8 nm/min. until silicon nitride layer 11 is exposed, at which point the second reactive ion etching process may be terminated, also “at leisure”, with no danger of penetrating silicon nitride substrate 11 by more than about 60 Angstroms. The appearance of the structure is now as shown in FIG. 5 . 2 nd Embodiment [0047] Referring now to FIG. 6 , the process of the 2 nd embodiment starts with sputter cleaning of the surface of SiN substrate layer 11 onto which is deposited layer of tantalum nitride 61 to a thickness between about 20 and 30 Angstroms. This is immediately followed by the deposition (onto the top surface of 61 ) of layer 62 of NiCr to a thickness between about 20 and 30 Angstroms. Note that it is critical for the effectiveness of this embodiment that layers 61 and 62 always be used together. The motivation for this is the excellent adhesion of TaN to SiN, the excellent adhesion of NiCr to TaN, and the excellent adhesion of Ru to NiCr. Furthermore, NiCr is an effective seed layer for Ru so it also serves to minimize the resistivity of Ru layer 63 . [0048] Next, layer 63 of ruthenium is deposited on layer 62 and then alpha tantalum layer 64 is deposited on ruthenium layer 63 . Layers 61 - 64 now constitute a base layer on which MTJ devices can be formed. Seen in FIG. 6 are pinned layer sub-stack 65 , insulator tunneling layer 66 and free layer/capping layers 67 . The individual MTJ devices are formed by etching layers 65 - 67 (under a tantalum hard mask) by means of CF 4 —CH 3 OH, which etching process stops when alpha tantalum layer 64 is reached. The appearance of the structure after the individual MTJ devices have been formed is as illustrated in FIG. 6 . [0049] Referring next to FIG. 7 , following the formation of the MTJ devices they are coated with conformal continuous layer 71 of a material known to protect the MTJ junction during the bottom electrode etch that follows. Suitable materials for this layer include SiO 2 , SiN, and SiN/SiO 2 , with SiO 2 being preferred. Moving on to FIG. 8 , once layer 71 is in place, photoresist layer 81 is applied over the entire surface and patterned so as to define the individual bottom electrodes, following which this pattern is transferred to layer 71 by etching its unprotected areas. [0050] As shown in FIG. 9 , once all photoresist has been removed layer 71 becomes a hard mask suitable for etching alpha tantalum layer 64 . This is accomplished by means of a first RIE process based on one of several possible gaseous compounds of carbon and fluorine, such as CF 4 and CHF 3 , with CF 4 being preferred. It is important to note that the initial thickness of layer 71 is critical as it should be thin enough to provide good spatial resolution of the etched parts but thick enough so that there is always present a sufficient thickness to protect the areas that underlie it. This minimum remaining thickness should be about 600 Angstroms. [0051] When layer 63 of ruthenium becomes exposed, the etch rate falls off substantially—typically by a factor of about 10, at which point first reactive ion etching may be terminated “at leisure” with no danger of etching through ruthenium layer 63 and penetrating silicon nitride substrate 11 . The appearance of the structure is now as shown in FIG. 9 with arrow 92 pointing to the region of separation between two individual bottom electrodes [0052] The remains of layers 64 and 71 now serve as a hard mask for the removal of unprotected areas of ruthenium layer 63 , as well as layers 62 and 61 , by means of a second RIE process. The etchant used in the second reactive ion etching process is one of several possible gaseous compounds of carbon, oxygen, and hydrogen such as CO+NH 3 , CH 3 OH, and C 2 H 5 OH, with CH 3 OH being preferred. Once all exposed ruthenium has been removed, the etch rate drops by a factor of about ⅔ when silicon nitride substrate 11 becomes exposed, at which point the second reactive ion etching process may be terminated with minimal penetration of the silicon nitride substrate and with a non-zero thickness of conformal continuous layer 91 still present. This remnant of layer 91 can now serve as a protective layer for the structure. [0053] In summary, the advantages of the invention include: [0054] (a) It results in a well defined vertical profile for each MTJ [0055] (b) It avoids re-deposition of etching by-products on the device surface [0056] (c) It avoids any extensive over etching of the underlying thin SiN ILD. [0057] (d) it avoids possible exposure of the underlying Cu word line, thereby avoiding Cu corrosion by the etching chemicals [0058] (e) It provides an easily controlled manufacturing scheme for the bottom electrode layer of an MRAM device. [0059] (f) It solves the problem of weak adhesion between the BE and ILD [0060] (g) It provides a BE with good electrical conduction [0061] (h) It protects the exposed MTJ junction during BE etch.

Formation of a bottom electrode for an MTJ device on a silicon nitride substrate is facilitated by including a layer of ruthenium near the silicon nitride surface. The ruthenium is a good electrical conductor and it responds differently from Ta and TaN to certain etchants. Adhesion to SiN is enhanced by using a TaN/NiCr bilayer as “glue”. Thus, said included layer of ruthenium may be used as an etch stop layer during the etching of Ta and/or TaN while the latter materials may be used to form a hard mask for etching the ruthenium without significant corrosion of the silicon nitride surface.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates more in particular to such a method and apparatus wherein non-cohesive bottom material, such as for example sand, or soft clay of mixtures of sand and soft clay, is fluidized by injecting a fluid at low velocity and at low pressure into the bottom material and wherein the conduit is allowed to sink into the fluidized bottom material. 2. Prior Art A related method and apparatus is described in British Pat. Nos. 1,219,879 and 1,291,250. The method of these patents is satisfactory when applied to the burying of a conduit in a bottom of a body of water when the bottom material along the planned route of the conduit is non-cohesive. However, when in certain areas of the planned route of the conduit lumps of cohesive material, for example lumps of hard clay, are present, difficulties may arise when the method of the above kind is applied. This is caused by the fact that the fluid used for the fluidization of the non-cohesive bottom material is injected at low pressure and at low velocity so that the fluid is not able to erode lumps of cohesive bottom material such as hard clay. In order to erode the lumps of cohesive bottom material high pressure fluid jets can be used, for example having a nozzle pressure drop in the range of about 100 to 1,000 psi. Power consumption of such high pressure jets is, however, rather high, in particular since a large number of such high pressure jets have to be applied because in cohesive bottom material such as hard clay, each jet issuing from a high pressure nozzle creates a hole having only a small diameter. Other pertinent art includes U.S. Pat. Nos. 2,659,211; 3,181,301; 3,504,504; 3,638,439; 3,751,927; 3,786,642; 3,877,237. SUMMARY OF THE INVENTION It is a purpose of the invention to provide a method and apparatus of the above kind, wherein only a relatively small number of nozzles for the high pressure jets is necessary so that a considerable reduction of the total power consumption of the high pressure jets is obtained. For this purpose the method of the invention comprises the steps of: A. DISPLACING A FLUIDIZATION DEVICE ALONG THE CONDUIT, B. VIA THE FLUIDIZATION NOZZLES OF THE FLUIDIZATION DEVICE INJECTING FLUID AT LOW VELOCITY AND AT LOW PRESSURE INTO THE NON-COHESIVE BOTTOM MATERIAL ADJACENT TO THE CONDUIT SO THAT THE NON-COHESIVE BOTTOM MATERIAL IS FLUIDIZED, C. ALLOWING THE CONDUIT, TOGETHER WITH THE FLUIDIZATION DEVICE, TO SINK INTO THE FLUIDIZED BOTTOM MATERIAL, D. If any cohesive bottom material is encountered, eroding the cohesive bottom material by injecting fluid at high velocity and at high pressure into the cohesive bottom material via the fluidization nozzles on the front of the fluidization device, E. DURING THE INJECTION OF THE FLUID AT HIGH VELOCITY AND AT HIGH PRESSURE INTO THE COHESIVE BOTTOM MATERIAL, MOREOVER MOVING THE FLUIDIZATION NOZZLES ON THE FRONT OF THE FLUIDIZATION DEVICE IN A DIRECTION OTHER THAN THE DIRECTION OF DISPLACEMENT OF THE FLUIDIZATION DEVICE, SO THAT A WIDE OPENING IS FORMED IN THE COHESIVE BOTTOM MATERIAL BY THE FLUID JETS ISSUING FROM THE SAID NOZZLES. Preferably, the movement of the fluidization nozzles according to step e is a rotation around an axis. An apparatus for carrying out the method according to the invention comprises a frame adapted to be displaced along the conduit, fluidization nozzles arranged on the frame, means for supplying fluid at low velocity and at low pressure to the fluidization nozzles, wherein the fluidization nozzles on the front of the frame are arranged in such a manner that they are movable relative to the frame in a direction other than the direction of displacement of the fluidization device, wherein means are present for supplying fluid at high velocity and at high pressure to the fluidization nozzles on the front of the frame and wherein means are present for moving the fluidization nozzles on the front of the frame relative to the frame. Preferably, the fluidization nozzles on the front of the frame are so arranged that they are rotatable around an axis relative to the frame. DESCRIPTION OF THE DRAWING The drawing shows a schematic side view of use of the apparatus. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawing reference numeral 1 indicates the top surface of the bottom of a body of water. A pipeline 5 is laying on the top surface 1. In order to bury the pipeline 5 in a fluidization device generally indicated by reference numeral 6 is displaced along the pipeline 5. The lower part of the frame 7 is provided with two spaced apart parallel tubes 8, each having a large number of fluidization nozzles 10. Each tube 8 is in communication with a fluid supply tube 11 which is provided with a fluid inlet 12. A number of rollers 9 is secured to the frame 7. The front of the fluidization device 6 is provided with two pairs of tubular elements 13 and 14 which are in communication with a fluid inlet 18. Each tubular element of a pair is spaced apart from the parallel to the other tubular element of said pair. Around each tubular element 14 a cylindrical element 15, having a larger diameter than tubular element 14, is arranged in such a manner that it is adapted to rotate around its longitudinal axis. The cylindrical element 15 is provided with a number of fluidization nozzles 16. A motor 17, preferaby a hydraulic motor, is arranged at the top end of the cylindrical element. The cylindrical element 15 is mounted in a fluid-tight manner on the tubular element 14. The tubular element 14 is provided with openings (not shown) which are adapted to create a fluid communication between the space within the tubular element 14 and the space within cylindrical element 15. Around each tubular element 13 a cylindrical element 20, having a larger diameter than tubular element 13, is arranged in such a manner that it is adapted to rotate around its longitudinal axis. The cylindrical element 20 is provided with a number of fluidization nozzles 21. A motor 22, preferably a hydraulic motor, is arranged at one end of the cylindrical element 20. The cylindrical element 20 is mounted in a fluid-tight manner on the tubular element 13. The tubular element 13 is provided with openings (not shown) which are adapted to create a fluid communication between the space within the tubular element 13 and the space within cylindrical element 20. The operation of the apparatus as shown in the drawing is as follows. The fluidization device 6, which is basically U-shaped as explained in the patent specification pertaining to British Pat. No. 1,219,879, is placed over the pipeline 5 so that it straddles the pipeline 5. The fluidization device 6 is displaced along the pipeline 5, for example by pulling it along the pipeline, for example by means of a winch on a work-boat. During this displacement of the fluidization device 6, fluid, for example water, is supplied to fluid inlet 12 and to fluid inlet 18. This water can be supplied to inlets 12 and 18 for example from a boat or barge which is connected to the inlets 12 and 18 by means of hoses (not shown). The water, which is supplied at low pressure and at low velocity to inlet 12, is passed via fluid supply tube 11 and via the tubes 8 of the fluidization device 6 to the fluidization nozzles 10. The water which is supplied at low pressure and at low velocity to inlet 18, is passed via tubular elements 14 and via tubular elements 13, respectively via the openings (not shown) in tubular elements 13 to the spaces within cylindrical elements 15 and within cylindrical elements 20 passes at low velocity and at low pressure respectively through the fluidization nozzles 16 and 21. The water leaving the fluidization nozzles 10, 16 and 21 is injected at low pressure and at low speed into the non-cohesive bottom material, which is for example sand, soft clay, or a mixture of sand and soft clay. The water injected into the non-cohesive bottom material will cause fluidization of said bottom material, so that the fluidized bottom material will behave like a liquid. In the drawing the area of the bottom which is in the fluidized condition is indicated by the reference numeral 3. The area of the bottom which has not yet been fluidized is indicated by the reference numeral 2. Since the bottom material in the fluidized area behaves like a liquid, the fluidization device 6 sinks into the fluidized bottom material until the rollers 9 contact the pipeline 5 and then the pipeline 5 together with the fluidization device 6, sinks into the fluidized bottom material, so that the position is reached as shown in the drawing. By displacing the fluidization device 6 along the pipeline 5 while injecting water via the fluidization nozzles 10 into the bottom material it is possible to bury the pipeline 5, as explained more in detail in the patent specifications pertaining to Applicant's British Pat. Nos. 1,219,879 and 1,291,250. If non-cohesive bottom material lumps of material are present which are of such a cohesive nature that fluidization is not possible, special measures have to be taken to break up or to erode such lumps of cohesive material. In the drawing a lump of cohesive material, which consists for example of hard clay, is indicated by the reference numeral 4. As soon as the fluidization device 6 encounters said lump 4, measures are taken to raise the pressure of the water supplied to the fluid inlet 18. This water, which is supplied at high pressure and at high velocity, is passed through the nozzles 16 and 21. The motor 17, which is for example driven by the water supplied at high pressure to the tubular element 14, drives the cylindrical element 15 so that the cylindrical element 15 rotates around its longitudinal axis. The motor 22, which is for example driven by the water supplied at high pressure to the tubular element 13, drives the cylindrical element 20 so that the cylindrical element 20 rotates around its longitudinal axis. The rotation of the cylindrical elements 15 and 20 can be continuous or instead it can be a swinging movement for example over an angle of 90°. The water leaving the fluidization nozzles 16, and 21 at high pressure and at high velocity erodes the part of the lump 4 of hard clay which would form an obstacle to the burial of the pipeline. Because of the rotation of the cylindrical elements 15 and 20, the water jets issuing from the nozzles 16 and 21 cover a wide area, so that a wide opening is formed in the lump of cohesive clay 4. Said wide opening allows the passage of the fluidization device 6 and the burial of the pipeline 5. In the embodiment of the invention as described above, the movement of the fluidization nozzles on the front of the fluidization device, in a direction other than the direction of displacement of the fluidization device, is a rotation around at least one axis. Instead, if desired, the movement of the said nozzles can be a linear movement in a direction other than the direction of displacement of the fluidization device. If desired, the fluidization nozzles on the front of the fluidization device, may be moved as well in a direction other than the direction of the displacement of the fluidization device, during the supply of water at low velocity and at low pressure to these nozzles. Some fixed fluidization nozzles 23 may be arranged adjacent to the corner formed by the elements 13 and 14 in order to cover the bottom area near said corner. These nozzles 23 are adapted to be fed as well with the fluid supplied via fluid inlet 18 and like the nozzles 16 and 21, the nozzles 23 are adapted to operate both with fluid supplied at low velocity and at low pressure to cause fluidization of non-cohesive bottom material and with fluid supplied at high velocity and at high pressure to cause erosion of lumps of cohesive bottom material.

The invention relates to a method and apparatus for burying a conduit at the bottom of a body of water.

BACKGROUND OF THE INVENTION The present invention relates to rice bowls and more particularly to a rice bowl which can be repeatedly used without the need to wash. Conventional disposable kitchen utensils are generally made of foamed plastics, which are to be thrown away each time after use. However, the use of foamed plastics may cause an environmental pollution because regular foamed plastics are not dissolvable in the weather. Further, foamed plastics may produce chemical reaction when it is used to contain hot fluid. During chemical reaction, harmful substances may produce simultaneously. Therefore, it is harmful to people's health to use such kind of disposable products for containing foods. An object of the present invention is to provide a rice bowl which can be repeatedly used without the need to wash. Another object of the present invention is to provide a rice bowl in which the cover layers are made of a kind of plastic material which does not cause chemical reaction when it is heated by hot fluid. Still another object of the present invention is to provide a rice bowl which does not produce environmental pollution. A yet further object of the present invention is to provide a rice bowl which is inexpensive to manufacture. In an embodiment of the present invention, a rice bowl includes a deep, rounded body which comprises several layers of plastic films smoothly secured thereto by means of a retainer ring. Two inner circular channels which have each a wider inner bottom and a narrower upper open are internally made on the body of the rice bowl so that the plastic films can be firmly retained thereto when they are covering over the surface of the rice bowl. The plastic films can be easily split off one after another through an indented line each time after meal, so that the rice bowl can be repeatedly used without the need to wash. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of a rice bowl in accordance with the present invention; FIG. 2 is a cross-sectional view of a retainer ring according to the present invention; FIG. 3 is a sectional assembly view of a rice bowl according to the present invention; FIG. 4 is a partly sectional view of a rice bowl according to the present invention, illustrating the positioning of plastic films and sponge sheet in an inner circular channel and a retainer ring in an external circular channel; FIGS. 5 through 10 illustrate a rice bowl production flow chart according to the present invention; FIG. 11 is a perspective view of a rice bowl embodying the present invention; and FIG. 12 illustrates an operation to split off an outer layer of plastic films from a rice bowl in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 through 4, a rice bowl in accordance with the present invention is generally comprised of a body 1, a retainer ring 2, a body holder 3, a set of plastic films 4 and a sponge sheet 5, wherein the plastic films 4 and the sponge sheet 5 are pressed to firmly attach to and cover on the inner surface of the deep, rounded body 1. As illustrated, the body 1 comprises two inner circular channels 10, 11, internally around its inner bottom and inner flank portion. The two circular channels 10, 11 have each a cross section including a wider inner bottom and a relatively narrower upper opening so that the plastic films 4 (or Mylar films) can be firmly retained thereto. An external circular channel 12 is made on the body 1 around its outer flank portion so that the retainer ring 2 (which has an arrow-like cross section as illustrated in FIG. 2) can be mounted thereon to bind up the plastic films 4 thereto. An outer thread 13 is made on the base portion of the bowl 1 so that the bowl holder 3 can be secured thereto through screw joint. As alternate forms of the present invention, the bowl holder 3 can be attached to the base of the bowl through any known connecting methods. FIGS. 5 through 10 illustrate a rice bowl production process according to the present invention. Referring first to FIGS. 5 and 6, a body 1 is positioned upside-down (with its open disposed downward) and disposed right above a bowl-shaped wooden mold 6. A set of plastic films (or Mylar films) 4 is mounted on the bowl-shaped wooden mold 6 which is fixedly secured to a movable stand 60, a sponge sheet 5 is further mounted on the bowl-shaped wooden mold 6 above the plastic films 4. The movable stand 60 is then moved upward to push its top bowl-like wooden mold 6 against the body 1 permitting the circular projecting portions 61, which are externally made on the wooden mold 6 corresponding to the two circular channels 10, 11 of the body 1, to respectively insert in the two circular channels 10, 11 of the body 1 such that the sponge sheet 5 and the plastic films 4 are simultaneously squeezed to secure to the body 1 and become firmly retained by the two circular channels 10, 11 of the body 1. Because the circular channels 10, 11 have each a wider inner bottom and narrower upper opening, the sponge sheet 5 and the plastic films 4 can be firmly clamped by the circular channels 10, 11 as soon as they are pushed to insert therein. As soon as the plastic films 4 and the sponge sheet 5 are pressed to secure to the body 1, a movable sleeve 7 is pushed to sleeve on the body 1 so as to turn the protruding portion of the plastic films 4 to cover over the outer wall surface of the body 1. Now, please refer to FIGS. 7 and 8. After the protruding portion of the plastic films 4 are forced by the movable sleeve 7 to cover on the outer wall surface of the body 1, a retainer ring 2 is directly mounted the outer wall of the body 1 over the plastic films 4. A rotary cylinder 8 which comprises cutting elements is moved downward to push the retainer ring 2 to seat in the external circular channel 12 of the body 1 so as to bind up the plastic films 4 with the body 1. During the operation of the rotary cylinder 8, the useless protruding portions of the plastic films 4 are trimmed by the cutting elements of the rotary cylinder 8 and the plastic films 4 are simultaneously pressed smooth on the body 1. Referring to FIGS. 9 and 10, after plastic films or Mylar films are covered on a body 1, bowl holder 3 which has an inner thread 130 is secured to the outer thread 13 of the base of the body 1 permitting the edge of the bowl holder 3 firmly pressed on the retainer ring 2 which is mounted on the external circular channel 12 of the body 1. FIG. 10 illustrates a finished product according to the present invention. Referring to FIGS. 11 and 12, the outer layer of plastic films 4 on the body 1 of a bowl in accordance with the present invention can be split off each time after meal, through the indented line 9 which is made on the plastic films during the production of the same, such that a clean bowl is ready for immediate use without the need to wash it.

A rice bowl, which comprises a plurality layers of plastic films smoothly secured thereto by means of a retainer ring and covering over the deep, rounded body thereof. The plastic films can be split off one after another each time after meal, so that the rice bowl can be repeatedly used without the need to wash.

BACKGROUND OF THE INVENTION The invention relates an apparatus to extract clean, cooled or heated bottled water from a water cooler/dispenser for distribution to a refrigerator or ice maker or other remote outlet. More specifically, the invention relates to a originally installed or retrofitted remote dispensing apparatus for use with conventional water heating/cooling dispensers having bottled water for dispensing the water substantially instantaneously to a remote outlet. In general, clean cold water can be made available in a household by means of either an expensive refrigerator with a cold water dispenser or a separate cooler and replaceable water bottles. The prior art shows water cooling and distribution systems of various types. Currently, there are two methods of direct dispensing of clean, cold water in a home. One method involves the use of bottled water and a cooler, the cooler often rented to the consumer. The bottles must be replaced and/or refilled from time to time with new bottles containing the water supply. A second method involves the use of built-in water dispensers in modem refrigerators. Refrigerators incorporating cold water dispensers are relatively expensive, and for the owner of the more conventional refrigerator, the problem still exists. It would be extremely expensive to retrofit existing refrigerators to incorporate water coolers therein. Another problem encountered with household water supplies is that of clean drinking water. Although the use of carbon and other filters has proliferated, carbon filters have a serious drawback. At room and higher temperatures, the charcoal used in such filters is a good breeding ground for bacteria. And, such filter systems do not allow the use of a conventional water cooler/heater to supply treated water to a remote location. In this situation, the consumer has already invested in a water cooler and replacement bottles in order to insure a steady supply of cooled or heated clean drinking water. Duplication in the form of additional water dispensers, bottles or cleaners is wasteful where the fresh treated water supply already exists within the home or office. U.S. Pat. No. 3,118,289, which issued to R. Schultz on Jan. 21, 1964 and U.S. Pat. No. 5,083,442, which issued to M. Vlock on Jan. 28, 1992 provide solutions to one or the other of the problems mentioned above. However, the Schultz patent does not address the problem of clean water, and the Vlock refrigerator would be expensive to produce. In order to obtain cold water using the Schultz apparatus, it would be necessary to flush all of the warm water out of any pipes or tubes downstream of the water tank in the refrigerator. Adapting the Vlock cooling system to existing conventional refrigerators would be too expensive to be practical. U.S. Pat. No. 5,502,978, issued to Field on Apr. 2, 1996, shows a carbon filter recirculating system. This invention involves a carbon filter and cooling reservoir combination for mounting in a refrigerator, a pipe system containing a faucet for dispensing cold water and returning water to the filter, and a pump/timer combination for periodically recycling the water in the pipe system through the filter, whereby cold water is always available at the faucet. Another attempt to solve the problem of remote availability of a water supply is found in kits available from manufacturers of liquid pumps, which ordinarily comprise a pump with tubing to siphon water from a bottle and supply the siphoned water to a remote location. This system has the drawback of requiring duplication of resources and extra storage space for a large water container. Another drawback of this system is that the water is not conditioned by the water cooler unit prior to its being transmitted to a remote location. Thus water can be neither cooled nor heated by a water cooler unit, and duplicate heating or cooling means must be supplied intermediate the water container and the remote outlet. Again, none of these inventions solve the problem of making a pre-existing water supply in a conventional water cooler/heater available to remote locations. The present invention provides a simple, inexpensive means of providing the water from a pre-existing water cooler to remote locations on demand without duplication of the water cooler equipment and without extensive modification of existing refrigerators or plumbing. SUMMARY OF THE INVENTION The present invention provides a simple, inexpensive means of pumping bottled water from a pre-existing water cooler to remote locations such as refrigerators and water faucets on demand without duplication of the water cooler equipment and without extensive modification of existing refrigerators or plumbing. The invention employs conventional, easily available parts with a custom pump bracket assembly in order to achieve its result. The invention also allows bottled water suppliers to retrofit bottled water dispensers/coolers in order to supply clean drinking water to refrigerators, sinks, and other remote outlet or faucet locations. The invention can supply a conventional refrigerator icemaker whether the icemaker is a stand-alone interior unit or a door mounted dispenser. The pumping of the water from the remote water dispenser is automatic and on demand, employing a pump that is sensitive to a pressure drop caused by opening a remote faucet. In accordance with the present invention, there is provided an apparatus whereby conventional bottled water dispensers/coolers may be used to supply water to a remote outlet; Another object of this invention is to provide an apparatus for pumping a consumer's favorite bottled water brand automatically into the ice maker and water dispenser of a conventional refrigerator; Another object of this invention is to provide an apparatus for pumping a bottled water such that the consumer can locate the bottled water dispenser/cooler anywhere in a home or office; Another object of this invention is to provide an apparatus for pumping a bottled water automatically on demand when a remote faucet is opened; Another object of this invention is to provide an apparatus that may be retrofitted to existing bottled water dispensers; Another object of this invention is to provide an apparatus that may be installed in existing homes and office or in new construction; Other objects and advantages will be more fully apparent from the following disclosure and appended claims. Accordingly, the present invention relates to a an apparatus for use with a bottled water dispenser comprising, depending on the application, a self-puncturing type pipe tap/saddle mount; a pump with a built-in predetermined constant pressure sensing device that keeps the pressure at a factory set level, and tubing sufficient to connect the water dispenser with the remote outlet BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features and objects of this invention and the manner of obtaining them will become apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a schematic view of an embodiment of the invention used with a single faucet water dispenser; FIG. 2 is a schematic view of an embodiment of the invention used with a dual faucet water dispenser; FIG. 3 is a schematic view of an embodiment of the invention used with a three faucet water dispenser; FIG. 4 is a schematic showing the inclusion of a switch; FIG. 5 is a view of the pump bracket; FIG. 6 is a parts list for preferred embodiments of the invention. DETAILED DESCRIPTION This invention is comprised of items manufactured by others, except for the pump bracket 6 , listed in FIG. 6 and shown in FIG. 5 . The invention is designed to give bottled water suppliers the ability to retrofit bottled water dispensers/coolers that are in place at this time. The invention may also be used in new production units with the omission of one part, the self-piercing saddle valve 18 listed in FIG. 6, substituting an alternative valve for diversion of the water from the unit. Referring now to the drawings, FIG. 1 illustrates a preferred embodiment of the invention where the existing water dispenser 24 has a single faucet 25 . The dispenser 24 also carries a water bottle 26 in the conventional manner. The dispenser 24 has internal existing tubing forming a conduit 27 (usually metal) installed during manufacture of the dispenser 24 . The conduit 27 is fluidly connects the water bottle 26 with the faucet 25 . Prior to the termination of conduit 27 at faucet 25 , a self-piercing saddle valve 18 is attached to the conduit 27 so that the conduit 27 is pierced and sealed to form a valve by which water may be extracted from the conduit 27 and diverted to a remote location. The self-piercing saddle valve 18 is fluidly connected to a polyethylene tube 3 of sufficient length to enable the respective desired locations of the water dispenser 24 and the remote outlet. The polyethylene tubing 3 is fluidly connected by means of a male connector 2 to an inlet port 30 of diaphragm pump 1 . The diaphragm pump 1 is preferably an automatic, pressure sensitive pump such as that manufactured by SHURflo, listed in FIG. 6 . The power to the diaphragm pump 1 is supplied by a conventional AC power cord 28 , preferably at standard U.S. household voltage of 115 volts. The power cord 28 is preferably spliced or wired into the power supply cord 29 that supplies power to the water dispenser 24 , thus eliminating the need for two power outlets. The diaphragm pump 1 has a second male connector 2 a located at an outlet port 31 for fluidly connecting the diaphragm pump 1 with polyethylene tube 3 a at the outlet side of diaphragm pump 1 . At this point, for single water outlets 34 such as a refrigerator, kitchen sink, bathroom lavatory, wet bar, or an optional gooseneck counter fixture 19 as listed in FIG. 6, the tube 3 a is of sufficient length to connect to the single remote location. The gooseneck counter fixture 19 may be installed in the kitchen sink or into any area of the countertop as required by the consumer. This gooseneck fixture 19 may also be installed in any lavatory or other area such as a wet bar or recreation area in the home whether it is an existing home or incorporated in the construction of a new home. Where multiple water outlets or plumbing points ( 35 a, b, c, d ) are to be configured with the same water supply, the tube 3 a is fluidly connected to a manifold comprised of one or more union tees 4 , 4 a and 4 b , preferably female tees manufactured by SMC as listed in FIG. 6 . The union tees 4 , 4 a and 4 b are preferably mounted to a floor joist or base trim using one or more wood screws 23 of the size listed in FIG. 6, and are shown in FIG. 1 connected in series with lengths of polyethylene tubing. Three of these manifold union tees 4 , 4 a and 4 b provide water from the water bottle 26 to four (4) remote outlets in the configuration shown in FIG. 1 . In general, one tee 4 can supply two (2) remote outlets; two (2) tees will supply three (3) outlets, etc. FIG. 2 shows the embodiment of the invention applied to a water dispenser 24 a configured with two spigots or outlets 25 a and 25 b . FIG. 3 shows the embodiment of the invention applied to a water dispenser 24 b configured with three spigots or outlets 25 a , 25 b and 25 c . It is customary for one of the three spigots to supply cooled water, one to supply heated water, and one to supply room temperature water. Depending on the desired outlet, the consumer may tap into any of the three supply lines for the desired water temperature to be supplied at the remote outlet ( 34 or 35 a, b, c, d ). In the case of the water cooler 24 only being used to supply a refrigerator model that has either an interior only or door mounted water and ice dispenser, the consumer may not want or need to get cold water directly from the cooler itself. FIG. 4 shows the use of a toggle switch 5 (usually installed by the water company mechanic) shown in the off position. Some coolers already have an option to turn off the cooler's compressor (some units having a hot water outlet may also have an independent switch installed in the heater power line). But in the case of a particular cooler not having this option, the 15 amp. (ampere) toggle switch 5 and two nylon insulated connectors 12 would be used. The toggle switch 5 should be installed in series in the compressor 32 AC hot lead 33 a (black), as opposed to the white lead 33 b or the green 33 c . This would allow the installer to switch off the compressor unit 32 while still maintaining AC input to the pump 1 . The wiring would be completed using #12 stranded wire in black (FIG. 6, part 11 ), red (FIG. 6, part 13 ), yellow (FIG. 6, part 14 ), green (FIG. 6, part 15 ) and white (FIG. 6, part 17 ) as required. This optional switch being installed would not only save wear and tear on the compressor unit in the cooler, it would also allow the consumer's utility bill to remain at the current level. The inclusion of this switch 5 would also be reflected in lower parts and replacement costs in overall maintenance of the cooler. FIG. 5 shows a pump bracket 6 , comprised of two identical bracket parts 6 a and 6 b . Each bracket part is an aluminum “L” shaped bracket with each side preferably one and one quarter inches in length. The configuration shown in FIG. 5 designates a hole schedule for drilling four “A” holes and two “B” holes as shown. With the center to center distance between “B” holes being 2.105 inches. The pump bracket 6 allows the diaphragm pump 1 to be secured to a surface convenient for the use and/or maintenance of the diaphragm pump 1 . In operation, the water bottle 26 supplies water through the conduit 27 located in dispenser 24 , where the water supply is diverted though the saddle valve 18 into a polyethylene tube 3 to supply a pump 1 that has a constant pressure sensing device built into the pump 1 that keeps the pressure at a predetermined level, usually a factory set level. When the consumer demands water from the refrigerator, in the case of a door mounted water dispenser the pump 1 turns on automatically when it senses the pressure drop. In turn pump 1 stops when demand ends and line pressure is back up to the preset factory level. In respect to the unit supplying the icemaker it works in the same fashion. The only difference is that the solenoid valve on the refrigerator is opened by a command from the icemaker as opposed to the customer. When the ice tray assembly in the icemaker in full, the icemaker closes the supply solenoid and the pump 1 again stops at the preset pressure. Since other modifications or changes will be apparent to those skilled in the art, there have been described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.

The invention relates an apparatus to extract clean, cooled or heated bottled water from a water cooler/dispenser for distribution to a refrigerator or ice maker or other remote outlet. More specifically, the invention relates to an originally installed, or retrofitted using a self-piercing saddle valve, remote dispensing apparatus for use with conventional water heating/cooling dispensers employing bottled water for dispensing the water substantially instantaneously to a remote outlet.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to metal oxide semiconductor technology and in particular to AND-gate clocks. 2. Description of the Prior Art The AND-ing of two or more inputs in a dynamic MOS clock circuit has been a particularly difficult problem, primarily because of the large transistor sizes involved and the high power dissipated before the clock is triggered. Previously, signals were ANDed in a dynamic clock as shown in FIG. 1. In this circuit the transistors T 10 and T 11 form an output stage wherein T 10 is the driving transistor. In this circuit, the output φ 3 is conditional upon both φ 1 and φ 2 being high. The problems occur when φ 1 occurs earlier than φ 2 , since the node N 5 goes high while the Node N 2 remains high. In order to prevent φ 3 from rising during this time, transistor T 11 is typically much larger than the transistor T 10 . However, the driving transistor, T 10 , must be very large in order to handle the capacitance C L . Thus, T 11 becomes very large, as much as approximately 700 microns in channel length for T 10 =100 microns. Also, during the time that φ 2 remains low, a large amount of current flows through T 10 and T 11 . SUMMARY OF THE INVENTION The present invention allows φ 1 to occur earlier than φ 2 . However, in this circuit, the gate of T 10 remains low, holding T 10 off. The additional power dissipated during this time is only the current flowing through an additional depletion transistor and a drain transistor. This can be kept small, since the capacitive load on the gate of T 10 is only that associated with the driving transistor T 10 , typically a small fraction of C L . Also, the transistor T 11 can now be made equal or even smaller than T 10 , since T 10 is now turned off. Finally, when the second output does go high, a full bootstrap voltage will appear on the input to the driving transistor, since the drain transistor will be turned off and the gate of the depletion transistor will be at the supply voltage. Therefore, considerable savings in power dissipation and layout area are achieved. DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a prior art AND-gate clock; FIG. 2 is a schematic diagram of one embodiment of the invention; and FIG. 3 is a clock diagram for use in connection with the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 2, a preferred embodiment of the invention, an AND-gate clock, is generally indicated by reference numeral 10. The AND-gate clock 10 is generally made up of stages shown by the broken blocks 12, 14 and 16. Block 12 includes an input stage, Block 14 includes an isolation stage, and Block 16 includes an output stage. Looking to the input stage 12, a first transistor T 1 is shown with its source grounded and its gate tied to a precharge signal. A second transistor, T 2 , has its source connected to the drain of the transistor T 1 , forming a node 1, N 1 . The transistor T 2 receives a first signal, φ 1 , at its gate, and a second signal, φ 2 , at its drain. A third transistor, T 3 , has its source grounded and its gate tied to the node, N 1 . The drain of the transistor T 3 is tied to the source of a transistor, T 4 , forming a node N 2 . The gate of the transistor T 4 is tied to a precharge signal while the drain is connected to a supply voltage, V cc . A fifth transistor, T 5 , has its source tied to the node N 2 and its gate connected to the supply voltage V cc . The drain of the transistor T 5 is tied to the gate of a sixth transistor, T 6 . The sixth transistor, T 6 , has its drain tied to the input first signal, φ 1 . A seventh transistor, T 7 , has its source grounded and its gate tied to the node N 2 . The drain of T 7 is connected to the source of an eighth transistor, T 8 , whose gate is tied to the source of T 6 . The drain of the eighth transistor, T 8 , is tied to supply voltage V cc . Finally, a capacitance C 1 is connected between the source of the transistor T 8 at the node N 4 and the gate of the transistor T 8 at node N 5 . The isolation stage 14 includes two transistors, T 9 and D 1 . D 1 is a depletion transistor. The transistor T 9 has its source connected to the node N 4 and its gate connected to the node N 2 . The drain of the transistor T 9 is tied to node N 6 to which the source of the transistor D 1 is also tied. The drain of the transistor D 1 is tied to the node N 5 and its gate is tied to the node N 4 . The output stage is a driver circuit composed of transistors T 10 and T 11 . T 10 is a driver transistor with its gate connected to the node N 6 and its drain connected to supply voltage V cc . The source of the transistor T 10 is tied to a node N 7 which forms an output φ 3 . The transistor T 11 has its source grounded and its gate connected to the node N 2 . The drain of the transistor T 11 is connected to the node N 7 . A load capacitance is represented by the capacitor C L connected at the output N 7 . The operation of the AND-gate clock 10 may now be observed by referring to the timing diagram of FIG. 3. During precharge, φ 1 and φ 2 will be at zero volts and the precharge signal will be at a voltage level, typically V cc . In this manner the transistor T 1 is turned on while T 2 is off, bringing the node N 1 to zero volts. This turns off the transistor T 3 while the transistor T 4 has been turned on by a precharge signal, bringing node N 2 to V cc -V T , where V T is the threshold voltage. Transistor T 5 is similarly turned on by the supply voltage V cc , which brings the node N 3 to V cc -V T . In this manner, transistor T 6 is turned on, but the source and drain will be at zero volts because of φ 1 . The voltage at N 2 turns on the transistor T 7 , bringing N 4 to ground. As N 4 and N 5 are now at zero volts, the transistor T 8 is off. Because of the voltage at N 2 , the transistor T 9 is turned on, bringing the node N 6 to ground. Remembering that a transistor is on whenever V G -V S -V T is greater than 0, and that a depletion transistor has a negative threshold voltage, the zero volts at N 4 will still turn on the transistor D 1 . Because of the small difference between V G and V S , depletion transistor D 1 will operate somewhat as a resistance. Transistor T 10 will be turned off by the zero voltage at its gate while the transistor T 11 is turned on by the voltage level at N 2 , thereby taking the node N 7 to ground. Therefore, at this point, φ 3 is at zero output while both input signals are at zero input. If φ 1 and φ 2 occur simultaneously, the circuit operates as a clock circuit and the invention serves to produce an output at φ 3 . However, φ 1 and φ 2 do not always occur simultaneously, and, in many applications, φ 2 may well occur after φ 1 . Note that one objective here is to keep φ 3 low until both φ 1 and φ 2 are high. Referring to the prior art circuit in FIG. 1, if φ 1 occurs earlier than φ 2 , N 5 will be driven high while N 2 will remain high. A large current flow then occurs through transistors T 10 and T 11 , which can only be compensated for by making transistor T 11 much larger than transistor T 10 . This is typically seven times as large. However, the transistor T 10 must be very large in order to drive the load capacitance. Therefore, transistor T 11 is larger than desirable. Under the invention disclosed here, if only φ 1 goes high, while in the meantime φ p has gone to a zero stage, transistor T 1 is turned off while transistor T 2 is turned on. However, node N 1 remains at zero volts because of the input at φ 2 . Therefore, T 3 remains off, while T 4 has similarly turned off. N 2 will remain floating at about V cc -V T while N 3 , due to the inherent capacitance C i across the gate and drain of T 6 , will float up due to the rise of φ 1 . Thus, a full signal φ 1 is transmitted across the transistor T 6 . It should be noted that the node N 4 has remained at ground and the full signal at N 5 will now charge the capacitors C 1 . Transistor T 8 has turned on, which will then raise the node N 4 to a point between V cc and ground due to the current flow between T 8 and T 7 . This rise in voltage at N 4 will raise the node N 5 even higher because of a bootstrap effect and will maintain D 1 in an on state. The transistor D 1 and the transistor T 9 are ratioed to give approximately zero volts at N 6 . This is done by making T 9 larger than D 1 . In a typical case, the channel W 1 of D 1 might be 8 microns, causing the channel of T 9 to be approximately 56 microns. Finally, T 10 is maintained off by the low voltage at N 6 , and T 11 remains on, keeping N 7 at zero. Now as φ 2 rises to its voltage level, T 2 is turned on, bringing N 1 to a full V cc -V T , and turning on T 3 , bringing N 2 to zero volts. N 3 will now be brought toward zero volts, turning off T 6 , although N 5 maintains its charge due to C 1 . T 7 is now turned off as is T 11 , which brings N 4 to V cc -V T . This turns on the transistor D 1 hard with a full transmission of the charged N 5 to the node N 6 , which turns on the transistor T 10 . Because of the bootstrap effect at N 5 and N 6 , the node N 7 will receive a full V cc . φ 3 now is an output at a V cc level. In summary, the upper path through the transistor T 6 has offered a faster path than the lower path through transistors T 2 , T 3 . While the prior art allowed a current flow through transistors T 10 and T 11 , the AND-gate clock 10 provides an alternative current flow through D 1 and T 9 . In this manner, T 11 does not have to be made significantly larger than T 11 , as T 9 and D 1 have accomplished this purpose.

An AND-gate clock having an input stage, an output stage, and an isolation stage. The input stage receives two signals, and gates them to produce a high signal. The output stage is used to drive a load typically having a large load capacitance when both signals are true. The isolation stage isolates the input stage from the output stage when only one signal is true, therefore preventing power dissipation by current flow through the output driver stage. The isolation stage provides an alternative current path through smaller transistors, thereby incurring lesser power dissipation and requiring less layout area. A small driver stage may then be used.

BACKGROUND OF THE INVENTION 1. Field of the Invention Graft copolymers of starch-containing materials (SCM) with unsaturated organic monomers are well known in the art and can be tailored for use in many diverse applications. For example, starch graft copolymers having the appropriate ionic functionalities have been extensively used in paper and mineral separation industries as pigment retention aids capable of adjunctly serving as internal sizing agents or as flocculants. A discussion of prior art uses of such water-soluble polymers is found in "Recent Advances in Ion-Containing Polymers," M. F. Hoover and G. B. Butler, J. Poly. Sci. Symp. No. 45: 32-34 (1974). However, the future of SCM graft copolymers as an alternative to other functional agents may well hinge upon the introduction of a simple and economical procedure to prepare them. This invention relates to an improved process for the graft polymerization of acrylic monomers onto SCM. 2. Description of the Prior Art Starch graft polymerizations are conventionally promoted by initiation of free radicals on the starch backbone by (1) chemical treatment, (2) physical treatment, or (3) irradiation. Reviews of these prior art procedures are found in Block and Graft Copolymerization, Vol. 1, Chapters 1 and 2, Ed. R. J. Ceresa, John Wiley & Sons, Inc., New York, N.Y. (1973) and "Starch, Graft Copolymers," Encyclopedia of Polymer Science and Technology, Supplement No. 2, George F. Fanta and E. B. Bagley, pp. 665-699, John Wiley & Sons, Inc., New York, N.Y. (1977). Chemical procedures include treatment with (a) inorganic ions, e.g., ceric, chromic, and cobaltic; (b) redox systems incorporating a reducing agent and an oxidizing agent, such as ferrous ion-peroxide; and (c) organic materials, e.g., azo compounds, or solvents such as xylene, etc. All previously known free radical initiations by chemical methods have required a liquid medium which comprises either an aqueous solvent or a combination of aqueous and organic solvents. Consequently, recovery of the polymerization product involves isolation, washing, and drying steps. These steps are often the most difficult and expensive in preparation of SCM graft copolymers because high viscosities develop as the reaction progresses. Also the spent reaction medium has to be recovered and processed in order to avoid contamination of the environment. This has lead to the investigation of several dry methods for preparing SCM graft copolymers. Physical procedures for initiating free radicals which can be conducted in the dry state include ball milling [J. Poly. Sci. 62(174): S123-S125 (1962), R. L. Whistler and J. L. Goatley], mechanical mastication [Staerke 16(9): 279-285 (1964), B. H. Thewlis], and heat and mastication as by an extruder or similar device ["Water-Soluble Polymers,"Polymer Science and Technology, Vol. 2, G. F. Fanta et al., pp. 275-290, Plenum Publishing Corp., New York, N.Y. (1973)]. The resulting products from these procedures are actually block polymers, and they tend to be highly degraded, rubbery to hard, and both chemically and physically brittle. More useful grafted starch products, although degraded, have been prepared by a dry irradiation technique. Cobalt 60 has been used to initiate the free radicals as described in "Water-Soluble Polymers," supra, and U.S. Pat. No. 3,976,552. Other types of conventional irradiation include electron beam, ultraviolet, and X-rays. However, because of the advance technology required, expense and problems of scaleup, and hazardous nature of the reaction, irradiation techniques for initiation of free radicals in dry grafting of unsaturated organic monomers onto SCM has remained only a laboratory curiosity. These above factors all reduce the commercial desirability and practicability of the prior art methods of producing SCM acrylic graft copolymers. SUMMARY OF THE INVENTION I have now unexpectedly discovered that acrylic monomers can be grafted onto SCM in the dry state using a chemical, free radical initiation which does not require a liquid medium. Even more surprising is the discovery that the chemical initiator, consisting essentially of a peroxide, is able to promote free radicals on the starch backbone in a dry state reaction without the need of a reducing agent in a defined redox system. The acrylic monomers and peroxides are added to the SCM as powders or sprays and when the reactants are thoroughly blended, the reaction proceeds without mixing. In accordance with this discovery, it is an object of the invention to prepare graft copolymers of starch-containing materials by means of a chemically initiated dry state reaction. It is also an object of the invention to provide a simple and economical procedure for preparing starch-based graft copolymers which are characterized by either cationic, anionic, or nonionic functionalities. It is a further object of the invention to prepare pigment retention aids and dry strength agents for use in the manufacture of paper which are superior to similar products prepared by dry irradiation techniques. Other objects and advantages of this invention will become readily apparent from the ensuing description. DETAILED DESCRIPTION OF THE INVENTION Starch-Containing Materials (SCM). The starting substrate useful in these reactions includes starches and flours of cereal grains such as corn, wheat, sorghum, rice, etc. and of root crops such as potato, tapioca, etc. The starches or flours may be unmodified or modified by procedures by which they are dextrinized, hydrolyzed, oxidized, or derivatized as long as they retain sites for subsequent reaction. Starch fractions, namely amylose and amylopectin, may also be employed. These SCM preferably contain their normal moisture content of 10 to 15%, though moisture as high as about 25% can be employed if it is not raised much beyond this level by addition of the reagent. Reagents The acrylic monomers which can be grafted onto the above-mentioned SCM in accordance with the invention are characterized by the following structural formulas: ##STR1## wherein R 1 =--H, or is from the group of C 1 -C 6 straight, branched, or cyclic alkyl radicals; ##STR2## with the proviso that if R 2 is --H, then the functional group A is eliminated; wherein each R 3 is independently selected from the group of --H, and C 1 -C 6 straight or branched alkyl radicals, and wherein two R 3 substituents may be joined together to form a cyclic structure; and wherein m=0, 1 and n=1-6; Of particular interest, without limitation thereto, are monomers in which A and B are as follows: A=a cationic group selected from: ##STR3## wherein R 3 is as defined above, and may be the same as or different from the R 3 on the R 2 group; and wherein X=Cl - , Br - , or I - ; and X'=X, R 3 X, or R 3 SO 4 - ; or an anionic group selected from: ##STR4## wherein R 4 is --H, alkali or alkali earth metal, or is from the group of C 1 -C 6 straight, branched, or cyclic alkyl radicals; or a nonionic group selected from: ##STR5## wherein R 1 , R 3 , m, and n are as defined above and may be the same as or different from similar designations in the structure; and ##STR6## wherein R 3 and X are as defined above; and wherein R 5 =--CH 3 , ##STR7## wherein r=0-7. Of course, it is understood that mixtures of the monomers could also be employed. Expressed in terms of weight percent, the amount of reagent for use in the reaction should be in the range of about 1-150% based on the dry weight of the SCM starting material. However, 3 to 18 weight percent is preferred. Catalysts Peroxide catalysts which can be incorporated in the reaction mixture to initiate free radicals include hydrogen peroxide; organic peroxides such as benzoyl, and acetyl; and inorganic peroxides of alkali and alkali earth metals such as sodium and calcium. In accordance with the invention, these peroxides constitute non-redox catalysis systems. Such a system is defined herein as one which excludes a discrete reducing agent; that is, an oxidizable agent present in the reaction mixture having the primary function of reducing the peroxide. For the non-flour SCM, the amount of peroxide needed to effect catalysis expressed as weight percent of O 2 based upon the dry weight of the SCM will be in the range of about 0.01 to about 0.5%, with the preferred range being 0.02-0.2%. It should be noted that the peroxides also serve as bleaching agents for the flours in the reaction. For example, a white corn flour product may be produced from a yellow corn flour starting material. Therefore, because of the color pigment (xanthophyll) and protein content of the flours about twice the amount of peroxide is needed as compared with a similar starch grafting reaction. Also, because the content of protein and pigment in agricultural vary from growing season to growing season, this amount of peroxide might require some adjustment to achieve the desired results for flours. Reaction Conditions When admixed with the SCM, the reagent and peroxide additives may be in either a dry powdery state or else dissolved or dispersed in a liquid vehicle such as water. The order of addition is not critical. If a vehicle is employed, its level should be limited to the extent that the reaction mixture as a whole remains in the form of a powder and its total moisture content is not raised beyond about 25% whereby the SCM would become sticky. A reaction mixture so characterized is defined herein as being in the dry state. Suitable reaction vessels include mixers of the conventional types used in industry, such as sigma blades, ribbon blades, pin blades, etc. I have found that continued mixing is optional once the additives have been thoroughly impregnated into the SCM. This may vary from a few minutes to several hours depending on the efficiency of equipment and the scale of run. The point of thorough impregnation would be readily determinable by a person or ordinary skill in the art. The reaction is carried out on the acid side at about pH 2 to 6.5. Since most SCM are inherently characterized by a pH in the range of 5-7, adjustment is usually unnecessary. The reaction temperatures are normally held within the range of about 25°-100° C. for inversely related periods of time ranging from 3 weeks to 1-2 hours, in which time the reaction is completed. The reaction is finished in 4 hours at 70° C. and 8 hours at 60° C. Properties of Products SCM graft copolymers of ionic monomers produced by this method are generally characterized by their change. Quality products are determined by the positive (cationic) or negative (anionic) charge possessed by samples that maintain them over a pH range of 3 to 10, whereas starting materials or samples that have not completely reacted with the reagent do not maintain the same ionic charge over the pH range. For those SCM products possessing a positive charge, cationic efficiencies are also helpful in determining their quality and effectiveness in end-use applications such as pigment retention aids in paper pulp. If reacted to completion within the limits of the time and temperature parameters set forth above, cationic efficiencies on the order of 99-100% are normally obtained. The SCM acrylic acids and esters (Formula 1), amides (Formula 2), and aminimides (Formula 3) produced by this process can be used in whatever application that similar products are conventionally employed as known in the art, and over a broad range of acid and alkaline pH's from about 3-10. For example, in the manufacture of paper, the cationic derivatives are useful pigment retention aids and strengthening agents when added to the wet pulp in concentration on the order of about 0.1 to 2% based on the dry weight of the pulp. These products may also be used in conjunction with other additives which are compatible with their ionic functionality as easily determined by a person in the art. Test Methods For purposes of evaluating the SCM products prepared in the examples below, the following tests procedures were employed. 1. pH was measured with a Beckman meter on a 1-2% aqueous pasted sample. The pasting procedures were water bath or steam jet cooking as described in Die Starke 28(5): 174 (1976). 2. Streaming current values were measured with a streaming current detector manufactured by Water Associates, Inc., Framingham, Mass. The instrument determines the magnitude of the cationic (positive) or anionic (negative) charge possessed by a sample. A 0.5% pasted sample (water bath cooked) was tested for these values (SCV) at various pH levels. The pH value was obtained by adjusting the paste solution with either 1 N HCl or NaOH solutions. 3. Cationic efficiency was determined by a modified procedure of Mehltretter et al., Tappi 46(8): 506 (1963) as reported in Tappi 52(1): 82 (1969). Briefly, percent efficiency was obtained photometrically when a 0.5% paste (cooked by water bath) sample is tested for the retention on dilute cellulosic pulp fibers of "Halopont Blue" (an intensely blue organic pigment). 4. Handsheets were made and tested by procedures cited in Tappi 52(1): 82 (1969). Controls containing no product additive as well as those containing 2% of product additive based on oven-dried unbleached pulp were prepared. The percent increase in sheet properties due to the additive were reported. Products tested were 1% pasted samples prepared by steam jet cooking. 5. Nitrogen determinations (dry basis) on samples were obtained by Kjeldahl analyses and moisture content on samples by drying them to constant weight at 100° C. in vacuo over phosphorous pentoxide. 6. To determine the amount of monomer grafted to polymer (SCM+monomer) and homopolymer (monomer+monomer) in the products, samples were washed by the following method: (1) distilled water; (2) 60:40 mixture by volume of ethanol:distilled water; (3) 100% ethanol. Ten grams of sample were stirred in a centrifugal bottle for 1/2 hour with 100 ml. of (1) at 25° C. The slurry was then centrifuged for 15 minutes and the supernatant poured off. This was repeated once. The residue was stirred with 100 ml. of (2), stirred with 100 ml. of (3), centrifuged, filtered, and washed with (3). The washed sample was oven dried overnight at 50° C., ground up, and analyzed. The following examples are intended only to further illustrate the invention and are not intended to limit the scope of the invention which is defined by the claims. EXAMPLE 1 One hundred and twenty-five grams (dry basis) of commercially obtained wheat starch having a 10% moisture content and 0.08% Kjeldahl nitrogen were placed in a laboratory model sigma blade kneading machine equipped with a removable transparent plastic cover, reagent admitting means, and a valved jacket for confining steam or coolant. The reagent was "Sipomer Q-6" (solution, Table I) of which 20 g. (75%, 12 weight percent monomer based on dry weight of starch) was sprayed onto the starch in 10 minutes while mixing. Mixing was continued 1/4 hour before flaking in powdered "Novadelox" 0.74 g. (32% benzoyl peroxide, 0.024% O 2 based on dry weight of starch). Mixing was continued another 1/4 hour, stopped, and samples were removed, bottled, and stored at 60° C. for 6 hours (A), 8 hours (B), and 10 hours (C). Table II gives results of analyses at various reaction time periods. A superior operative final cationic product is indicated by the presence of significantly increased retention efficiency of "Halopont" pigment dye (cationic efficiency) by the pulp and in the magnitude and positive (cationic) charge (SCV) over pH range of 3 to 10 as compared to those found for wheat starch (starting material) and sample 1A. EXAMPLE 2 Example 1 was repeated except a temperature of 70° C. was used for sample (A) 2 hours, (B) 4 hours, (C) 6 hours. Results are given in Table III. EXAMPLE 3 Example 1 was repeated except for the following: The reagent was "Sipomer Q-1" (solid, Table I) of which 16.7 g. (90%, 12 weight percent monomer based on dry weight of starch) was flaked into the starch. "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). Sample (A) was reacted at 25° C., (B) at 70° C., and (C) at 100° C. Samples were analyzed at various time periods to monitor the reaction and final results are present in Table IV. Further evaluation of products A and C is given in Example 14. TABLE I__________________________________________________________________________ % Mono- mer Phys- Reagent Mole in ical TradeAcrylic monomer Structure wt. reagent state Charge Company name__________________________________________________________________________2-hydroxy-3-methacryloyl- oxypropyltrimethylammonium chloride ##STR8## 237.6 90 solid cat- ionic Alcolac Chemical Corp. Sipomer Q-12-methacryloyloxyethyl- trimethylammonium methyl sulfate ##STR9## 283.4 40 liquid cat- ionic Alcolac Chemical Corp. Sipomer Q-52-methyacryloyloxyethyl- trimethylammonium chloride ##STR10## 207.6 75 liquid cat- ionic Alcolac Chemical Corp. Sipomer Q-6methacrylamidopropyl- trimethylammonium chloride ##STR11## 220.8 50 liquid cat- ionic Jefferson Chemical Co. MAPTAC2-acrylamido-2-methyl- propanesulfonic acid ##STR12## 207.0 100 solid an- ionic Lubrizol Corp. AMPS3-acrylamido-3-methyl butyltrimethylammonium chloride ##STR13## 234.8 100 solid cat- ionic Lubrizol Corp. AMBTAC__________________________________________________________________________ TABLE II______________________________________Reaction Resultsconditions SCV % Time, Temp., pH pH pH CationicExample hours °C. 3 6 10 efficiency______________________________________1A 6 60 +2.8 +2.8 -0.1 471B 8 60 +11.5 +5.6 +4.9 1001C 10 60 +6.3 +8.9 +3.3 100wheat -- -- +2.0 -16.0 -18.0 37starch______________________________________ Products A, B, and C have 13% moisture and 0.77% nitrogen; pH of pastes was 4.3. TABLE III______________________________________Reaction Resultsconditions SCV % Time, Temp., pH pH pH CationicExample hours °C. 3 6 10 efficiency______________________________________2A 2 70 +3.1 +2.9 -0.7 472B 4 70 +9.2 +7.4 +4.3 992C 6 70 +11.0 +12.3 +5.9 99______________________________________ Products A, B, and C have 14% moisture, and 0.78% nitrogen; pH of pastes was 4.3. TABLE IV______________________________________Reaction Resultsconditions SCV % Temp., pH pH pH CationicExample Time °C. 3 6 10 efficiency______________________________________3A 21 days 25 +8.0 +12.7 +5.0 1003B 4 hours 70 +14.5 +18.0 +5.6 1003C 2 hours 100 +16.3 +12.1 +4.0 100______________________________________ Products A, B, and C have 14% moisture, and 0.70% nitrogen; pH of pastes was 4.7. EXAMPLE 4 Example 1 was repeated except for the following: The reagent was "Sipomer Q-5" (solution, Table I) of which 47 g. (40%, 15 weight percent monomer based on dry weight of starch was sprayed onto the starch. "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). The sample was reacted for 2 hours at 100° C. The final product had 23% moisture, 0.70% nitrogen, pH 4, SCV at pH 3+10.8, pH 6+6.9, pH 10+4.8, and cationic efficiency 100%. Further evaluation of this product is given in Example 14. EXAMPLE 5 Example 1 was repeated except for the following: The reagent was "MAPTAC" (solution, Table I) of which 30 g. (50%, 12 weight percent monomer based on dry weight of starch) was sprayed onto the starch. Hydrogen peroxide was used instead of benzoyl peroxide and 0.88 g. (30% peroxide, 0.19% O 2 based on dry weight of starch) was sprayed onto the starch. The sample was reacted for 2 hours at 100° C. The final product had 19% moisture, 1.42% nitrogen, pH 4.5, SCV at pH 3+9.4, pH 6+5.1, pH 10+4.6, and cationic efficiency 99%. Further evaluation of this product is given in Example 14. EXAMPLE 6 Example 1 was repeated except for the following: The reagent was "AMBTAC" (solid, Table I) of which 15 g. (100%, 12 weight percent monomer based on dry weight of starch) was flaked into the starch. "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). The sample was reacted 2 hours at 100° C. The final product had 12% moisture, 1.27% nitrogen, pH 4.2, SCV at pH 3+8.4, pH 6+10, pH 10+3.4, and cationic efficiency 99%. EXAMPLE 7 Example 1 was repeated except for the following: The reagent was "AMPS" (solid, Table I) of which 15 g. (100%, 12 weight percent monomer based on dry weight of starch) was flaked into the starch. "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). The sample was reacted 2 hours at 100° C. The final product had 14% moisture, 0.88% nitrogen, pH 3.4, and SCV at pH 3 -14, pH 6 -19, pH 10 -21. The excellency of this anionic product is shown by the magnitude and negativity of its charge over a pH range of 3 to 10. EXAMPLE 8 Example 1 was repeated except for the following: The reagent was "Sipomer Q-1" (solid, Table I). "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). In sample (A) 18.9 g. (90%, 13.6 weight percent monomer based on dry weight of starch) of reagent was used, (B) 14.4 g. (10.4 weight percent), (C) 8.9 g. (6.4 weight percent), and (D) 4.4 g. (3.2 weight percent). The samples were reacted 2 hours at 100° C. To determine the amount of monomer grafted to the SCM, the homopolymer was washed out of the products by test procedure 6, analyzing both product and washed product. As noted by the results given in Table V, a relatively large proportion of the monomer is grafted onto the SCM. Further evaluation of these products is given in Example 14. EXAMPLE 9 For purposes of comparing the process of the invention to that of the prior art, Example 1 was repeated except for the following: The starch was 100 g. (dry basis) and the reagent was "Sipomer Q-5" (solution, Table I) of which 15.2 g. (40%, 6 weight percent monomer based on dry weight of starch) was sprayed onto the starch. Portions of the sample were bottled and irradiated with a Cobalt 60 source at three levels. Sample (A) 0.1 Mrad, (B) 1.0 Mrad, (C) 3.0 Mrad. The results are presented in Table VI. EXAMPLE 10 Comparative Example 9 was repeated except for the following: The starch was 125 g. (dry basis) and the reagent was "Sipomer Q-1" (solid, Table I) of which 12.6 g. (90%, 9 weight percent monomer based on dry weight of starch) was flaked into the starch. The results are presented in Table VI. TABLE V______________________________________ % MonomerProduct, % Washed product, % graftedExample Moisture Nitrogen Moisture Nitrogen to SCM*______________________________________8A 13 0.69 7 0.49 718B 12 0.54 8 0.36 678C 12 0.40 7 0.29 738D 13 0.23 7 0.15 65______________________________________ ##STR14## EXAMPLE 11 Comparative Example 9 was repeated except for the following: The starch was 125 g. (dry basis) and the reagent was "MAPTAC" (solution, Table I) of which 7.6 g. (50%, 3 weight percent monomer based on dry weight of starch) was sprayed onto the starch. The results are presented in Table VI. The cationic products prepared by the irradiation techniques of Examples 9-11 were inferior to the cationic products in the preceding examples of this invention as shown by their SCV and cationic efficiency values. EXAMPLE 12 For comparative purposes, Example 5 was substantially repeated without the peroxide catalyst. The reagent was "MAPTAC" (solution, Table I) of which 30 g. (50%, 12 weight percent based on dry weight of starch) was sprayed onto the starch. The mixture was held for 4 hours at 100° C. The moisture content, nitrogen content, paste pH, SCV, and cationic efficiency of the product were determined. The product was then washed by test procedure 6, and the moisture and nitrogen contents were again determined. The nitrogen content was less than in the wheat starch starting material. The results are shown in Table VII. EXAMPLE 13 For comparative purposes, Example 6 was substantially repeated without the peroxide catalyst. The reagent was "AMBTAC" (solid, Table I) of which 15 g. (100%, 12 weight percent monomer based on dry weight of starch) was flaked into the starch. The mixture was held for 4 hours at 100° C. The moisture content, nitrogen content, paste pH, SCV, and cationic efficiency of the product were determined. The product was then washed by test procedure 6, and the moisture and nitrogen contents were again determined. The nitrogen content was less than in the wheat starch starting material. The results are shown in Table VII. TABLE VI______________________________________ Results % Cat- Analysis ionicEx- % pH SCV effi-am- Co.sup.60 Mois- % of pH pH pH cien-ple Mrad ture N paste 3 6 10 cy______________________________________9A 0.1 17 0.30 4.8 +2.4 +2.4 -9.3 429B 1.0 17 0.30 4.8 +16.0 +9.8 +2.1 609C 3.0 17 0.30 4.8 +6.9 +11.0 +1.1 6410 3.0 14 0.69 5.6 +10.8 +15.9 +1.1 5811 3.0 16 0.38 5.0 +6.1 +8.8 +0.8 55______________________________________ TABLE VII__________________________________________________________________________ % Monomer SCV %Product, % Washed product, % grafted pH of pH pH pH CationicExampleMoisture Nitrogen Moisture Nitrogen to SCM* paste 3 6 10 efficiency__________________________________________________________________________12 18 1.38 8 0.04 <3 6.0 +4.3 -0.7 -2.4 3413 13 1.41 7 0.02 <2 6.0 +4.9 +0.5 -0.7 34__________________________________________________________________________ ##STR15## The SCV and cationic efficiency values and the nitrogen result on the washed product of Examples 12 and 13 indicated that the reaction did not take place in the absence of peroxide. EXAMPLE 14 Unbleached handsheets were prepared and tested as described above in test 4. Results are given in Table VIII. Products of this invention were far superior in increasing burst (three times) and tensile (six times) strengths in unbleached handsheets above that of the starting material. Also they were considerably better than that of the Co 60 irradiated sample of Example 9C. The jet-cooked pastes of Examples 8A, B, C, and D after standing 24 hours at room temperature showed a definite pattern of improvement in preventing paste retrogradation (settling out of solids) due to the modification. The improvement was 14>10>6>3 weight percent of the reagent, whereas the wheat starch starting material and Example 9C settled out in 1 hour. It is to be understood that the foregoing detailed description is given by way of illustration and that modification and variations may be made therein without departing from the spirit and scope of the invention. TABLE VIII______________________________________ 2% Addition of sample to unbleached handsheetsExample % Burst* % Tensile*______________________________________3A 47 343C 55 324 49 285 50 318A 55 338A (washed) 55 328B 51 298C 47 318D 42 319C 32 21starting material 17 5(wheat starch)______________________________________ *% Increase over control paper containing no sample.

Acrylic monomers are grafted onto starch-containing materials by a novel dry state process in which small amounts of peroxides chemically initiate the free radical reaction. Since the process is dry and the resultant products contain no contaminants, it is unnecessary to isolate, wash, and dry them before use. The products are useful in the paper and mineral separation industries.

TECHNICAL FIELD [0001] The invention relates to a post having a post anchor connected with the post and comprising two end sections, where one section extends into the post and the other section is intended for fastening on or in another element. BACKGROUND OF THE INVENTION [0002] A post anchor of this type is known from the prior art, for example, from DE 36 34 266. In that document, a screw-in threaded rod is adhesively bonded in a corresponding drillhole in a post, a longitudinal groove being provided on the threaded rod so that the glue can accordingly be allowed to enter the drillhole between the threaded rod and the wall of the drillhole. [0003] Another post anchor is known from DE 199 12 815, in which a threaded spike is provided on a plate which can be placed against the underside of a post, this threaded spike penetrating the post during positioning of the post anchor. Provided on the opposite side of the post anchor is a sleeve with an internal thread so that an anchor bar can be subsequently screwed in outside of the post. [0004] In all the proposals of the prior art, even when the threaded rods are glued in, there is a problem in terms of the parallelism of the post anchor and post. This means that the post anchor does not usually have its center axis lying exactly parallel to the longitudinal axis of the post. This is an unwanted property of such a system and a disadvantage when assembling such post anchor systems on building sites. [0005] In practice, the unit consisting of threaded rod and post is therefore not, as in DE 199 12 815, put together once on the building site; instead, this takes place beforehand so that the parallelism can be achieved to the greatest possible degree under industrial production conditions. [0006] Moreover, the connection of metal anchors in wooden posts usually leaves something to be desired in terms of the force required to extract the anchors, for example. SUMMARY OF THE INVENTION [0007] Taking this prior art as a starting point, the object on which the invention is based is to provide a post anchor of the type mentioned in the beginning which has better parallelism and in which the fixing is, moreover, better secured against twisting. [0008] In an embodiment of the present invention a post includes a post anchor connected with the post and includes two end sections, where one section extends into the post and the other section is intended for fastening on or in another element, wherein the post includes a drillhole, wherein one section is a drill bit section, having in a first segment, adjacent to its tip, a smaller drilling core diameter and having in a second segment, arranged nearer to the other section, a larger drilling core diameter, wherein the drillhole has substantially no radial play with the drill bit section for arranging the section introduced in the post in the drillhole in the post in a substantially stress-free manner. [0009] In another embodiment of the present invention, a post anchor includes two end sections, where one section can be introduced into a post and the other section is intended for fastening on or in another element, wherein the section which can be introduced into the post is a drill bit section for making a drillhole in the post in a substantially stress-free manner, which drillhole has substantially no radial play with the drill bit section, characterized in that the drill bit section has in a first segment, in the longitudinal direction adjacent to its tip, a smaller drilling core diameter and in a second segment, arranged nearer to the other section, a larger drilling core diameter. [0010] In yet another embodiment of the present invention, a method includes introducing a post anchor into a post, characterized in that it includes the following steps: (a) [0011] drilling a drillhole in the post with the drill bit section ( 11 ) of the post anchor, (b) introducing adhesive into the drillhole with the drill bit section inserted so as to take up, by filling, any remaining radial play and the axial play of the drill bit section in the drillhole, or, alternatively, withdrawing the drill bit section, introducing adhesive into the drillhole and reinserting the drill bit section into the at least partially adhesive-filled drillhole. [0012] This object is achieved with a post having a post anchor connected with the post and comprising two end sections, where one section extends into the post and the other section is intended for fastening on or in another element, wherein the post comprises a drillhole, wherein one section is a drill bit section, having in a first segment, adjacent to its tip, a smaller drilling core diameter and having in a second segment, arranged nearer to the other section, a larger drilling core diameter, wherein the drillhole has substantially no radial play with the drill bit section for arranging the section introduced in the post in the drillhole in the post in a substantially stress-free manner. BRIEF DESCRIPTION OF THE DRAWING [0013] FIG. 1 is a perspective view of a post according to an embodiment of the present invention DETAILED DESCRIPTION [0014] The invention will now be described in more detail with the aid of an exemplary embodiment with reference to the drawing. The single drawing shows a partly sectioned perspective view of a post together with an inserted post entrance. [0015] The reference number 1 is used to denote a post. The post 1 is made of wood and has a square cross section. Of course, the cross section may also be shaped differently, being for example round or elliptical, rectangular or polygonal. The material of the post 1 may also be chosen from another material only if these materials are similar to wood within the context given below. The similarity in question is in particular important for plastic materials. [0016] Said post 1 has a longitudinal axis whose orientation here is indicated by the arrow 2 running parallel to it. The post 1 can be fastened on a wall or floor surface (not shown in the FIGURE) with the aid of a post anchor (anchor 10 for short) according to the invention. The FIGURE shows one moment during the production of the connection between anchor 10 and post 1 when the anchor 10 has not yet been fully sunk in the post 1 . [0017] The anchor 10 is preferably constructed in one piece and as such comprises at least two different regions 11 and 12 . The first region 11 is made up of an auger bit, this region 11 being intended to be set into the post 1 . The second region 12 can be designed according to the particular application of the post anchor; in particular it may thus be a threaded rod section. This threaded rod section 12 , either by itself or by way of a further section (not shown in the drawing), can be positively connected to a drive, for example a drilling machine, to enable the auger bit 11 to be driven into the post 1 . [0018] The FIGURE shows, in dotted form, the outlines of a drillhole 20 in which the auger bit section 11 has already been advanced more than halfway. Instead of using an auger bit which allows chips cut out of the post to be lifted out, use may also be made of any other drill bit which makes possible the production of a stress-free bore, in particular in wood, in which there is no radial play. Radial play here is to be understood as meaning the distance 21 between the outside of the drill bit 11 and the inner wall of the bore 20 . [0019] The auger bit 11 extracts chips from the drillhole 20 and at the same time creates a certain free space in the axial direction, i.e., along the longitudinal axis 13 of the anchor 10 , into which free space an adhesive can be passed in through the upper opening 22 of the bore 20 once the drill bit section 11 has been fully inserted. Particularly advantageous adhesives are epoxy resin-based adhesives and polyurethanes. Before the adhesive is introduced, the anchor 10 may preferably be rotated back by an eight to a half of a rotation in order to make it easier to pass in the adhesive. Alternatively, it may be completely withdrawn, the adhesive poured in and the drill bit reinserted. [0020] A drill bit according to the prior art only supports its own weight and forces are solely applied in the longitudinal direction, i.e., along the axis 13 . The post anchor 10 here receives the bearing pressure. This is true for the threaded rod section 12 as well as for the drill bit section 11 . Therefore the drill bit section 11 according to the invention is divided into two different segments, having received the reference numerals 41 and 42 . The two segments are made in one piece. The drill bit section 11 has first drilling core diameter or central core 31 , followed by a central segment 42 of the drill bit 11 , having a second core diameter 32 , being larger than the diameter of the first drilling core diameter 31 . [0021] In a preferred embodiment the first drilling core diameter 31 is set between one fourth to one half of the external diameter of the drill bit 11 . The second drilling core diameter 32 is set between one half and ⅘ of the external diameter of the drill bit 11 . This creates between the two segments 41 and 42 a discontinuity between the diameters of the drilling cores 31 and 32 , respectively. The ratio between the axial length of the areas 41 and 42 can be, e.g., between 1:4 and 1:1 preferably around 1:2 for achieving a larger stiffness of the post anchor 10 without impeding the extraction of the chips due to a larger core drill diameter. [0022] Instead of two segments 41 and 42 it is also possible to provide three segments, wherein the smallest core drill diameter has a value of one fourth, the second central core drill diameter has a value of one half and the third largest core drill diameter has a value of ¾ of the external diameter of the drill bit 11 . It is of course possible to choose different transitions and a higher number of segments. [0023] Additionally it is possible to use a continuously enlarging drill core for achieving a steady growth of stiffness of the anchor 10 in direction of arrow 2 . [0024] The threaded rod section 12 comprises two different elements, the threaded rod as such and the drill chuck support. The threaded rod section 12 and the drill chuck support can be positioned one behind the other on an axis 13 , but it is also possible to adapt the side surface of the threaded rod section 12 , e.g., providing a groove, to create a drill chuck support within this section. [0025] At location 33 the drill head has a slightly larger diameter then the drill core 34 . [0026] The drill bit according to the invention ensures axially correct fitting, allowing the anchor 10 to be well centered in the post 1 . The prior art according to DE 199 12 815 employing the spike results in a displacement of the material of the post 1 and thus in stresses therein. The auger bit 10 produces a stress-free bore in wood and other comparable materials. [0027] The length of the anchor 10 depends on its field of application. For a post 1 having a diameter or cross-sectional dimensions of from 5 to 10 centimeters, given a diameter of the auger bit 11 of between 6 and 10 millimeters, a customary total length of the anchor may be between 10 and 70 centimeters. Preferably, this length is divided in half between the drill bit part 11 and the threaded rod part 12 . Of course, it is also possible for the threaded rod 12 or the auger bit 11 to be shorter or longer than the respective other section. It is also possible to provide a connection element (not shown in the drawing) between the auger bit 11 and the threaded rod 12 (or a flat rod without a thread). This may be an outer hexagonal section or a disc which is oriented radially with respect to the longitudinal axis. [0028] The anchor 10 according to this invention provides a simple, very secure anchor device which is able to be centered and which is correctly aligned axially, this anchor device 10 being driven into the post 1 beforehand within a storage area or during the production of said post. Alternatively, the post anchor 10 may be set into the posts 1 provided on a building site once on site. [0029] The diameter of the drill bit section 11 of the post anchor 10 can be chosen between 5 and 18 millimeters and the total length of the post anchor 10 can be chosen between 10 and 100 centimeters, wherein said length is preferably divided equally between the drill bit section 11 and the other section 12 . [0030] The scope of protection is in no way intended to be limited by the preceding description showing an exemplary embodiment and shall apply only to the claims which follow.

Disclosed is a post anchor ( 1 ) comprising two final sections ( 11, 12 ), one ( 11 ) of which can be introduced into a post ( 10 ) while the other one ( 12 ) is used for fixing the anchor ( 1 ) to or in another element. The section ( 11 ) that can be introduced into the post represents a drill bit section ( 11 ) which is used for introducing a bore ( 20 ) into the post ( 10 ) in a substantially stress-free manner. The drill bit section ( 11 ) in the bore ( 20 ) is provided with essentially no axial clearance and is preferably embodied as a screw bit. The drill bit section ( 11 ) has a first smaller drill core diameter ( 31 ) in a first zone ( 31 ) bordering the tip thereof while having a larger drill core diameter ( 32 ) in a second zone ( 32 ) located closer to the other section ( 12 ) in the longitudinal direction thereof ( 13 ).

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to Provisional U.S. Application No. 60/627,388 to Hawkins, which is hereby incorporated in its entirety. BACKGROUND [0002] 1. Field of the Invention [0003] This invention relates to refrigeration and specifically to the efficient cooling of freshly picked vegetables from the field. [0004] 2. Description of Related Art [0005] When produce, such as strawberries, cauliflower, cabbage, and the like, is harvested, workers in the field will pack the produce in cartons. These cartons or boxes are typically rectangular in shape and normally have side openings for facilitating holding of the cartons. Typically the cartons are stacked on pallets and the stacked cartons are in turn then transferred to a flat bed truck or other transportation means to be shipped to a distribution point. [0006] The shelf life of most produce is a function of how quickly the field heat can be removed from the produce once it has been harvested. If considerable time lapses from the time of harvesting to the time of initial cooling down of the produce, the overall shelf life at a retail store is substantially reduced. Any system which will speed up the process of pre-cooling or removing the field heat from the produce after harvesting, or which will increase the efficiency or reliability of machinery involved in such cooling, will have significant economic benefit. [0007] In U.S. Pat. No. 4,474,020, to Freeman, a cooling chamber for drawing down freshly picked and field warmed vegetables is disclosed. A group of individual pallets loaded with rectangular cartons of produce are placed in the field on a transport chassis and brought to the vicinity of the cooling chamber where they are simultaneously unloaded by a multi-pallet forklift truck. The chamber receives this multi-pallet load through an open door and a rear seal conforms to the periphery of the load to define a warm air return plenum. The main chamber door is closed to define a high pressure cool air plenum. Circulation of forced and cooled air occurs for rapid drawing down of the palletized load to a curing temperature. [0008] In U.S. Pat. No. 4,736,592, Ohling, an apparatus for directing cool air to stacks of containers holding freshly harvested produce to remove field heat is disclosed. The apparatus includes a housing having a suction fan for blowing air through an air cooler into a plenum from which the cool air passes through the containers of produce. The direction of the airflow is selectable by moving damper devices relative to the housing. [0009] A drawback of the prior art devices mentioned above is that the containers must be loaded and removed from the same entrance door area. Another drawback is that the devices are not readily adapted to work with differing sizes of pallets or differing sizes of stacks on pallets. A drawback of the Ohling device is that the change in the direction of airflow is accomplished with the use of dampers, which introduce a reliability risk and a maintenance cost. [0010] What is called for is an apparatus and method for the cooling of produce which allows for high volume through put, changes in direction in cooling air flow with a high reliability system, and seals which allow for sufficient latitude in container and pallet size and quantity to accommodate today's differing demands. SUMMARY [0011] An apparatus for the efficient cooling of produce directed to the cooling of freshly picked produce in containers on pallets. The apparatus has a first opening for the entrance of stacks of containers to be moved through cooling enclosure. The stacks of containers are moved through to a first cooling area wherein the containers are exposed to cooling air provided in a first direction. The stacks of containers are then moved through to a second cooling area wherein the containers are exposed to cooling air in a second direction. Isolation of the containers and routing of the air flow is supplemented with air inflatable seals which abut the containers. A method for the efficient cooling of produce utilizing an apparatus as described. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a top view of a two module apparatus according to some embodiments of the present invention. [0013] FIG. 2 is a side view of a two module apparatus according to some embodiments of the present invention. [0014] FIG. 3 is a partial cutaway view of an apparatus according to some embodiments of the present invention. [0015] FIG. 4 is an end view of cooling zone according to some embodiments of the present invention. [0016] FIG. 5 is a side view sketch illustrating the blower portion of a module according to some embodiments of the present invention. [0017] FIG. 6 is a top view sketch illustrating the blower portion of a module according to some embodiments of the present invention. [0018] FIG. 7 is an end view sketch illustrating the blower portion of a module according to some embodiments of the present invention. [0019] FIG. 8 is a side view of portions of an overhead air bag according to some embodiments of the present invention. [0020] FIG. 9 is an end view of portions of an overhead air bag according to some embodiments of the present invention. [0021] FIG. 10 is a side view of portions of an overhead air bag according to some embodiments of the present invention. [0022] FIG. 11 is a side view of portions of an overhead air bag according to some embodiments of the present invention. [0023] FIG. 12 is an end view of portions of an overhead air bag according to some embodiments of the present invention. [0024] FIG. 13 is a perspective view of portions of an expandable floor seal according to some embodiments of the present invention. [0025] FIG. 14 is an end view of a module showing a door according to some embodiments of the present invention. [0026] FIG. 15 is a sketch of a stack of produce cartons. [0027] FIG. 16 is pictorial representation of the air flow in a first zone according to some embodiments of the present invention. [0028] FIG. 17 is a pictorial representation of the air flow in a second zone according to some embodiments of the present invention. [0029] FIG. 18 is a sketch of the positive and negative pressure feeds and the flapper valve for the seal ducts according to some embodiments of the present invention. DETAILED DESCRIPTION [0030] FIGS. 1 and 2 are a top and side view, respectively, of a two module cooling apparatus 100 according to some embodiments of the present invention. In some embodiments of the present invention, a first module 101 and a second module 102 are linked front to back at center joint 111 . The cooling apparatus is adapted to receive pallets of cartons of produce via two infeed conveyors 112 , 113 . Typically, using strawberry cartons as an example, the pallets will be 40 inches wide and will have 108 cartons per pallet. Typically, the height of the cartons on the pallets will be 72 inches high. The cooling apparatus is not constrained by these dimensions and can accommodate variation in the sizes of the fed pallets and stacks as will be described below. [0031] In typical usage, pallets 109 , 110 will be fed in to the first module 101 via the infeed conveyors 112 , 113 . Pallets may be fed in groups of three per conveyor. A roll up door 108 is opened to allow the conveyors to move the produce into the first zone of the first module 101 . After the pallets have been moved into the first zone of the first module, the roll up door 108 is lowered. After cooling, the produce leaves the cooling apparatus 100 through a roll up door 107 . As seen in FIG. 2 , pallets 103 , 104 of cooled produce exits the cooling apparatus on outfeed conveyors 105 , 106 . Should the outfeed conveyors feed into a cooled area no doors may be required at the exit end of the apparatus. [0032] FIG. 3 is a partial cutaway view of a module 200 according to some embodiments of the present invention. In some embodiments of the present invention the module 200 has two zones 207 , 208 . Each of the zones 207 , 208 is of sufficient size to accept sets of three pallets 209 , 221 of cartons 210 , 222 of produce. The first zone is adapted to cool the produce by providing an air flow in a first direction, while the second zone is adapted to cool the produce by providing an air flow in a second direction. [0033] A first set of pallets 209 are moved along a first infeed conveyor 205 to transport a first plurality of produce cartons 222 into the first zone 207 . A second set of pallets 221 are moved along a second infeed conveyor 206 to transport a second plurality of produce cartons 210 into the first zone 207 . Typically both of the sets of pallets will be moved into the first zone simultaneously. The conveyor system may have an automated drive system in some embodiments. The pallets are moved into the first zone 207 and may substantially fill the first zone 207 along the length of the first zone 207 in the feed direction 228 . [0034] In some embodiments of the present invention, each portion of the conveyor system in each zone, and along each side of the zone, may have an independent drive system. The independent drive system may be coordinated such that the entire conveyor system works together to move pallets simultaneously. The conveyor system may be controlled by an electronic control system which implements the functionality just described. In addition, the electronic control system may have sensors incorporated which confirm that the inflatable seals are all deflated and withdrawn away from the cartons prior to allowing the conveyance of pallets by the conveyor system. In some embodiments, position sensors may be used to determine if the pallets of cartons have been conveyed into the proper position for sealing. [0035] In order to facilitate the cooling of the produce in the cartons, cool air is blown into the space along the sides of the cartons and flows through the cartons across the produce. Typically, as seen in FIG. 15 , produce cartons 260 are solid along one surface 263 and the surface opposite. Along the other two side surfaces of the carton, there are openings 261 allowing fluidic access to the produce 262 . Thus, cold air can be blown in from the sides in order to cool the produce. Additionally, if the cooling air cools the produce first by entering in one side of the carton, and then, after a period of cooling in that mode, the air flow is reversed, the produce on the other side of the carton will receive cooler air first and the cooling process will be much more even. In order to facilitate the air flow across the produce in the cartons, the cartons are substantially sealed relative to the inner surface of the enclosed zone so that the primary air flow is through the openings 261 and across the produce 262 . [0036] Referring back to FIG. 3 , a variety of inflatable seals are shown which are used to seal the inner surface of the enclosed area to the cartons, and thus route the cooling airflow through the cartons and across the produce. After the pallets are moved into the first zone 207 and have substantially filled the first zone 207 along the length of the first zone 207 in the feed direction 228 , overhead air seals 211 , 212 are inflated. The inflatable overhead seals are inflated with air and contact the cartons along their top surface. Inflatable side seals 224 , 223 , 215 , 216 , 225 are inflated with air and contact the cartons along their side surfaces at the ends of the sets of cartons. Inflatable lower seals 213 , 214 inflate with air and contact the cartons along the lower inside surfaces of the cartons. As seen in FIGS. 16 and 17 , these seals work together to divide the zone into regions such that pressurized cold air blown into one of the regions will travel through the side openings 261 in the cartons and across the produce. [0037] In some embodiments of the present invention, all of the inflatable seals for a single zone are fluidically coupled to a single ducting system. This ducting system then is either pressurized or placed into negative pressure by the switching of a flapper valve in the ducting system adjacent to the blower for that zone. The blower is able to provide either positive or negative pressure to ducting system coupled to the inflatable seals depending upon whether the flapper valve couples the ducting system to the positive pressure area downstream from the blower, or to the negative pressure area upstream from the blower. [0038] In some embodiments, the same blower which provides the cooling air also provides the positive and negative pressure for the inflatable seals. As the negative pressure from the upstream side of the blower is used to deflate the inflatable seals, and thus provide clearance between the seals and the produce to allow conveyance of the produce within the apparatus, the blowers will typically be running at all times that the apparatus is in the conveyance mode. [0039] As seen in FIG. 18 , the blower 219 provides the pressure for zone in a module. A positive pressure duct 232 is coupled to the blower housing and is a source for positive pressure air. A negative pressure duct 231 has an opening residing in the infeed stream to the blower and provides a source for negative pressure. Both the positive pressure duct 232 and the negative pressure duct 231 meet at a valve box 218 . The valve box 218 has an air actuated flapper valve which connects either the positive pressure or the negative pressure to the duct system which pressurizes the air inflatable seals for that zone. This system has the distinct advantage of using a single blower for all cooling processes as well as the sealing in a particular zone. An air filter 1010 is used to filter the positive pressure air from the blower before it reaches the duct system. [0040] The inflatable seals give a distinct advantage of being able to seal stacks of cartons of varying heights and widths. The inflatable seals are deflated when the pallets of cartons enter and exit the zone. The deflated seals may be subjected to negative pressure such that they collapse in an organized manner in order to not interfere with the movement of the cartons prior to and subsequent to cooling cycles. Also, due to their collapsible and expandable nature, the inflatable seals are adapted to seal cartons and pallets within a range of heights and widths. Also, as opposed to stationary flexible seats as used on prior art that must slightly interfere into the space occupied by the cartons in order to provide an air seal, the inflatable seals have the distinct advantage of eliminating all substantial interference with the cartons thereby avoiding hang-ups which are a serious problem with the art. [0041] In some embodiments, the inflatable seals are inflated and deflated using the same blowers that force the cooling air. As seen in FIG. 3 , a positive pressure duct 232 routes pressurized air into a valve box 218 which in turn routes pressurized air the inflatable seals in order to seal the inner surface of the enclosure to the cartons and pallet when the flapper valve within is actuated in a first direction. A negative pressure duct 231 routes negatively pressurized air to deflate the inflatable seals such that they collapse and clear the pallets and cartons such that the pallets can be conveyed through the enclosure when the flapper valve within the valve box is actuated in a second direction. In each zone, a positive pressure duct and a negative pressure duct meet in a valve box containing an air actuated flapper valve which will determine whether the ducting system fluidically coupled to the air inflatable seals will receive positive or negative pressure. [0042] After the produce has been sealed in the first zone 207 of the module and cooled with air flowing in a first direction across the produce, the first cooling cycle ends. The inflatable seals are then deflated and with negative pressure collapse and pull away from the cartons. The first and second plurality of produce cartons 210 , 222 are then moved along on the conveyor to the second zone 208 . Typically, a new set of cartons on pallets will be sent into the first zone behind the produce cartons 210 , 222 which have just moved into the second zone 208 . Once in the second zone, the first and second plurality of produce cartons 210 , 222 are sealed with a set of inflatable seals 230 , 226 , 229 215 , 216 used to seal the second zone. In the second zone 208 , the air flow may be in the opposite direction across the produce as in the first zone 207 . With subsequent zones set up to force cooling air in a different direction as with the prior zone, the air flow across the produce is reversed without the need for mechanical redirection of the cooling ducts, and without the requirements of maintaining such redirection mechanisms. [0043] FIG. 4 illustrates aspects of the inflatable seals according to some embodiments of the present invention. The inflatable center seal 411 (shown without the fabric outer bag portion) has a plurality of frame members 401 suspended from the ceiling of the enclosure. The frame members 401 are suspended using a plurality of rollers 402 such that the inflatable center seal 411 can collapse inward 403 when subjected to negative pressure and is deflated. When subjected to positive pressure, the inflatable center seal expands 410 , typically until the seal comes into contact with the comers of the cartons in the cooling area. This configuration allows for the easy sealing, and then unsealing, of the cartons of produce as they are moved into a cooling zone, sealed, cooled, unsealed, and then moved into the next zone (or out of the end of the apparatus) without the hanging up of the seals on the cartons. Additionally, this configuration allows for sealing against not just one width of carton stacks, but instead allows for sealing within a range of widths. [0044] The inflatable overhead seals 404 , 405 are also designed to be both adaptable and easy to use. The inflatable overhead seals 404 , 405 (shown in their inflated position in FIG. 4 ) inflate down from the ceiling in order to create a seal along the top of a stack of cartons. When it is desired to unseal the seal, as when the stacks are to be moved, the overhead seals are subjected to negative pressure, which draws the seals upwards and away from the stacks of cartons. A plurality of internal frame members 406 , 407 , 408 , 409 allow the inflatable overhead seals to maintain their structural and positional integrity as they are deflated such that they will be properly positioned to reseal when needed subsequently. Also, this configuration allows the seals to move down from the ceiling until contact is made with the tops of the carton stacks, and allows for sealing against a range of carton heights. This configuration also allows for clearance between the seals and the cartons when needed, as when moving the stacks. FIGS. 8, 9 , 10 , and 11 illustrate seal designs according to some embodiments of the present invention. [0045] In a typical embodiment, all of the air inflatable seals for a single zone are fluidically coupled to a single ducting system. This ducting system then is either pressurized or placed into negative pressure by the switching of a flapper valve in the ducting system adjacent to the blower for that zone. The blower is able to provide either positive or negative pressure to ducting system coupled to the inflatable seals depending upon whether the flapper valve couples the ducting system to the positive pressure area downstream from the blower, or to the negative pressure area upstream from the blower. Thus, a single command, that to change the position of the flapper valve for a particular zone, can be used to inflate (and seal) or deflate (and withdraw) all of the air inflatable seals in a particular zone. [0046] In some embodiments, the inflatable air seal bags are made from a coated fabric such as a rubberized nylon or similar material. The material need not be fully airtight, but sufficiently wind resistant such that the bags will remain inflated under the available pressure with a leak rate low enough that the seals function properly. In some embodiments, all of the seals in a zone which retract vertically when subjected to negative pressure may have some structural members in common such that they are joined into somewhat of an integrated unit. [0047] In some embodiments, an electronic control system may be used to control the sealing and unsealing of the air inflatable seals. A single control system may be used to control both zones of a two zone module. In some embodiments, a single control system may be used to control all aspects of the conveyance system and sealing system for a single module, or a multi-module apparatus. [0048] FIGS. 5, 6 , and 7 illustrate the forced air cooling and inflatable seals of a two zone module and the regions into which the zones are divided after the inflatable seals have sealed against the cartons in the enclosure according to some embodiments of the present invention. Blower 308 forces air through cooling coils 309 and into the area above enclosure ceiling 329 . The enclosure ceiling 329 has an open space 303 which allows for airflow of the cooled air down into the enclosure below. The cooled airflow enters a center region 324 between the cartons on the adjacent conveyors. As the cartons are sealed from overhead by inflatable overhead seals 314 , 315 and sealed along their vertical ends by inflatable side seals 322 , 323 and at their bottom with the inflatable lower seals 318 , 319 , the zone is essentially sealed off into three regions 324 , 325 , 326 . The cold air forced in through open space 303 into the center region 324 then flows through the cartons to the outer regions 325 , 326 . This airflow cools the produce in the cartons, with more cooling occurring in the produce along the centerline of the zone. The air that has traveled into outer regions 325 , 326 is then drawn up through the ceiling of the enclosure through outer open spaces 301 , 302 . This air flow then continues into the blower 308 , thus completing an airflow path for the first zone 327 . [0049] Once the produce has been exposed to the appropriate length of cooling with the first air flow direction, the seals are deflated and the pallets in the first zone 327 are moved into the second zone 328 where they are sealed in using the inflatable seals similarly to the first zone. In the second zone 328 , the blower 307 forces air through the cooling coils 310 . The cooled air flows down through outer open spaces 304 , 305 into regions on the outer periphery of the cartons. The positive pressure of the airflow forced the cooling air across the produce, this time from the outside regions toward the center region. The air then travels up through the center open space 306 and back into the blower 307 , thus completing an airflow cycle for the second zone. The produce has been cooled from both sides, which is desirable to cool the produce in an even manner. The air flow direction was changed across the produce without the need for heavy air flow dampers or other equipment. [0050] FIGS. 16 and 17 are pictorial representations of the air flow regimens described above. The first zone 327 described above is represented in FIG. 16 as a section 374 of the apparatus wherein the cold air 380 flows in through the ceiling into the center region 376 . As the pallets and cartons have been substantially sealed with inflatable seals, the air flows 385 substantially across the produce through the cartons into the outside regions 375 , 377 . The warmer air that has been used for cooling then flows 378 , 379 back into the ceiling to complete the airflow cycle as previously described. [0051] The second zone 328 described above is represented in FIG. 17 as a section 373 of the apparatus wherein the cold air 382 , 383 flows in through the ceiling into the outside regions 371 , 372 . As the pallets and cartons have been substantially sealed with inflatable seals, the air flows 384 substantially across the produce through cartons into the center region 370 . The warmer air that has been used for cooling then flows 381 back into the ceiling to complete the airflow cycle as described above. [0052] FIG. 7 illustrates a range of pallet widths and stack heights that can be accommodated by the inflatable seals according to some embodiments of the present invention. The inflatable overhead seals 314 , 315 can accommodate a range of stack heights 316 - 317 and still maintain the seal necessary for proper operation of the cooling apparatus. As the inflatable overhead seals 314 , 315 are deflated as the stack is moved into the zone, the deflation involves negative pressure and pulls the entire seal up towards the ceiling of the enclosure. As the seal is re-inflated, it may make appropriate contact through a range of heights, thus accommodating a range of stack heights. A similar situation is seen with regard to pallet widths and the inflatable lower seals. A range of pallet widths 320 - 321 may be accommodated by the inflatable lower seal 319 . As the inflatable lower seal 319 is deflated as the stack is moved into the zone, the deflation involves negative pressure and pulls the entire seal towards the center of the enclosure. As the seal is re-inflated, it may make appropriate contact through a range of widths, thus accommodating a range of pallet widths. [0053] FIG. 13 is an exploded view of aspects of the air inflatable lower seals for a two zone module according to some embodiments of the present invention. The air inflatable lower seals 440 , 441 , 442 , 443 are shown in their inflated positions. The air inflatable lower seals 440 , 441 , 442 , 443 are physically attached and fluidically coupled to the lower center ducts 445 , 446 . When the lower center ducts are subjected to negative pressure, the air inflatable lower seals 440 , 441 , 442 , 443 withdraw in a direction 444 towards the center of the apparatus. When subjected to positive pressure, the air inflatable lower seals 440 , 441 , 442 , 443 move outwards until they come into contact with and seal against the bottoms edges of the cartons or pallets on the conveyor system. [0054] FIG. 14 is an end view of a module showing a inlet door 1002 along the front side 1001 of a module. The inlet door rolls up into a storage unit 1003 . The module sits on a bottom surface 1004 on the ground or other area. [0055] In some embodiments of the present invention, the apparatus may have features to allow transportation without the need to be load up onto a tractor trailer, which may require a crane or significant lifting and pulling. In some embodiments, the apparatus is of sufficient width that a tractor trailer may be backed through it such that the rear wheels of the trailer are backed out of the apparatus after backing through it. The apparatus may then be jacked up and attached to the tractor trailer with the bottom of the apparatus sitting below the bed of the tractor trailer. The air inflatable seals which interfere with this operation may be removed before the tractor trailer is driven through the apparatus. Much of inflatable seal portion may remain in the apparatus and be adequately restrained. [0056] After the apparatus has been jacked up into place and attached to the tractor trailer, the apparatus may be moved to a new location. After arrival in the next location, the apparatus may be lowered back down to the ground and the tractor trailer may be driven back through the apparatus. [0057] A method for the cooling of produce comprising conveying two side by side sets of three pallets of produce cartons into a first enclosed zone. The sets of pallets are conveyed into a first zone while the air inflatable seals for the zone are subjected to negative pressure and are retracted. The pallets are conveyed into the first zone until they trip a position sensor that confirms that they have reached the proper position along the conveyor for sealing in the first zone. [0058] The flapper valve is then switched to place the duct system for the air inflatable seals into a positive pressure mode. The air inflatable seals then inflate and extend out to make a seal with the palletized cartons of produce, dividing the zone into sealed air spaces. Cooling air fed by a blower is fed into one or more of the sealed air spaces in such a manner that it is forced across the produce, thus cooling the produce. The air forced across the produce travels into another air space that is subjected to lower pressure and returns up to the blower. [0059] In an example embodiment using strawberries, the inlet air fed into the air spaces is at 27 F. The air temperature after the air has crossed the produce is in the range of 33 F. Using a four zone, two module apparatus, the produce remains in this first zone with a first air direction for 10-12 minutes. After the time period for cooling in this zone has expired, the inflatable air seals are subjected to negative pressure by the air actuation of the flapper valve in the valve box. [0060] The two sets of three pallets are then conveyed into a second zone. Once the appropriate location for the second zone has been reached by the pallets, the conveyor stops, and the air inflatable seals are re-inflated. Typically, there are another set of pallets behind the first which take the space in the first zone vacated by the pallets that have moved into the second zone. In the second zone, the air flow is configured such that the air flow across the produce is in the opposite direction as was the air flow across the produce in the first zone. The temperatures and the times for cooling in this zone are typically the same as used in the first zone. [0061] The cooling cycles and time are repeated as the produce travels through all four zones of the two modules. At the end of the final cycle, the produce will have been cooled for approximately 48 minutes and the produce will have reached the target temperature of 32-34 F. The cooled produce is now ready for transport. [0062] As evident from the above description, a wide variety of embodiments may be configured from the description given herein and additional advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is, therefore, not limited to the specific details, representative apparatus and illustrative examples shown and described. Accordingly, departures from such details may be made without departing from the spirit or scope of the applicant's general inventive concept.

An apparatus for the efficient cooling of produce directed to the cooling of freshly picked produce in containers on pallets. The apparatus has a first opening for the entrance of stacks of containers to be moved through cooling enclosure. The stacks of containers are moved through to a first cooling area wherein the containers are exposed to cooling air provided in a first direction. The stacks of containers are then moved through to a second cooling area wherein the containers are exposed to cooling air in a second direction. Isolation of the containers and routing of the air flow is supplemented with air inflatable seals which abut the containers. A method for the efficient cooling of produce utilizing an apparatus as described.

FIELD AND BACKGROUND OF THE INVENTION [0001] The present invention is a standoff force multiplier weapon, relating to distance control, enemy neutralization, and casualty reduction. [0002] When the U.S. military goes to war, it relies on sophisticated and efficient weaponry to defeat the enemy. Yet, no matter how sophisticated the weapons, an all-volunteer military cannot absorb large numbers of causalities. In an effort to reduce the number of causalities suffered by our troops, modern weapons are designed to deliver payloads from great distances with uncanny accuracy. Although these standoff weapon systems are intended to eliminate close infighting; pitch battles and firefights remain an integral part of military planning and tactics. [0003] Close infighting causes causalities because the ideal weapon balance has not been introduced into battle with the intention of neutralizing the enemy; rendering hiding useless; and eliminating counter fire. Many casualties occur when the enemy takes cover and returns fire. In fact, the best way to stop an enemy is to prevent them from using their weapons. If the enemy is deprived of the ability to return fire, the probability for causalities becomes near zero. The solution is to overwhelm the enemy with a firewall of pinpoint airburst detonations at the onset of battle and continue until the enemy is destroyed. The radius of the airburst detonations will devastate both the exposed and concealed. But, the firepower must be instantaneous, overwhelming and totally destructive. Fortunately, a new innovative weapon called the CMDP can accomplish both tasks simultaneously. The CMDP or Cruise Munitions Detonator Projectile is a weapon created to travel a predetermined distance to the enemy and detonate with pinpoint accuracy anywhere in the enemy's vicinity or range. The detonation of a single shell will suppress enemy fire and neutralized them at the same time. [0004] What makes the CMDP so deadly is: a) the distance to the target is determined by a range dial selector, laser range finder or radar, b) firing the gun and downloading range data into the CMDP's memory is done simultaneously, and c) the CMDP travels the distance to the target along a straight path and detonates. It can also be modified to detonate on impact. [0005] The CMDP application is not only limited to ground forces, it can also be used on aircraft; or tanks; in military camps; and on ships. CMDPs can be used with a modified grenade launcher to substitute for Claymore mines if motion detector sensors (systems) are positioned around the perimeter of a field camp. Aircraft, such as jets or helicopters equipped with the CMDP (along with an automatic tracking and aiming system) could defend themselves against enemy aircraft: SAMS, shoulder launched missiles and air-to-air missiles; by firing and detonating a CMDP or (CMDPs) at intersecting points along the object's fight path. The target will be destroyed. Current aircraft equipped with detection devices only warn of impending dangers, using flare and chaff dispensing systems to redirect threats, in order to evade them. Evading works sometimes, but the threat must be eliminated altogether to have a zero causality equation loss. AAA threats against attacking aircraft over a target area can be controlled and neutralized using the CMDP. Aircraft like the B52 bomber and A-10 Warthog could operate with impunity over targets while using the CMDP to destroy heat seeking missiles. And, if an aircraft lands in enemy territory, an undamaged CMDP/system has the potential to defend the aircraft and those on board. [0006] Unlike defense systems aboard ships where bullets must hit targets, the CMDP simply detonates in the path of the target. As described, the CMDP can be used as a defensive or offensive weapon. [0007] A Tank's main gun is another weapon platform that is known for its destructive power, but it too, has weaknesses against air-to-surface and shoulder launched missiles, that cause great causalities. Faced with immeasurable odds, multiple CMDPs fired from tanks can destroy hundreds, even thousands of enemy troops. And, if equipped with an automatic tracking and aiming system, it can defend itself against shoulder launched missiles and air-to-surface missiles by firing and detonating a CMDP or CMDPs at intersecting points along the object's fight path. [0008] Mortar attacks make military camps unsafe, resulting in loss of life and property. Lives can be saved with near zero percent causality if software controlled tracking systems equipped with CMDPs are used to defend against the incoming mortar. The gun systems can be daisy-chained to secure the entire camp. [0009] When Special Ops, patrol or recon units are in a jam and pinned down, they call in fire support to neutralize the enemy. If the action is too close; firing on the target is not an option. Without accurate firepower there will be no escape, resulting in inevitable causalities. These situations can be avoided if the units are armed with CMDPs, a modified grenade launcher equipped with a range dialer, laser range finder and thermo heat sensor. US forces should be confident that they have instantaneous and overwhelming firepower with them when fighting their way into and out of situations. The CMDP allows smaller forces to strategically neutralize larger forces with devastating effect. [0010] The CMDP is the optimum weapon for ground troops to engage snipers hiding on mountain ridges, in trees, rooftops, or building openings used for cover. It can also neutralize reinforced bunkers or weapons platforms. As previously stated, the CMDP is launched from a gun using a combination of a range selector; laser range finder, thermo sensor and radar to determine the distance to a target and to download the data into it. Adding or subtracting a quantity to or from the input data will achieve a desired distance. Aiming at a target is accomplished with a stand-alone gun or software controlled tracking system. The CMDP distance to the target is very accurate and is limited only by its range. SUMMARY OF THE INVENTION [0011] According to the present invention there is provided a CMDP for neutralizing large enemy ground forces and missiles while defending against enemy moving objects. The CMDP includes a data link and memory for downloading distance target information; a safe distance arming circuit; a pressure switch for initializing digital counting; and a comparator circuitry that determines the detonation time. [0012] According to one embodiment of the present invention, the CMDP is a shell requiring data input. [0013] According to another embodiment of the present invention, the CMDP is a shell. Preferably the shell is launched from a gun type system, tank or modified grenade launcher gun. [0014] According to a preferred embodiment of the present invention, the CMDP is a projectile. Preferably the projectile is launched to predetermined distances and then detonates. [0015] According to still further features in the described preferred embodiment, the projectile is a munitions. [0016] According to another feature in the described preferred embodiment, the projectile includes electronic circuitry for launch detection. [0017] According to still further features in the described preferred embodiment, the projectile includes an electronic safety circuit to arm the CMDP for detonation after clearing a safety zone. [0018] According to the described preferred embodiment, the projectile includes electronic circuitry for downloading range data into memory for targeting range. [0019] According to the described preferred embodiment, the projectile includes electronic circuitry for counter comparison detection to accurately determine when to detonate the munitions. [0020] According to a preferred embodiment of the present invention, the CMDP further includes electronic circuitry to detonate the projectile. [0021] According to a preferred embodiment of the present invention, the CMDP can be used to defend aircraft, warships and military camps against incoming missiles, mortars and enemy aircraft. [0022] According to a preferred embodiment of the present invention, the CMDP can be used to defend aircraft and passengers against enemy forces after forced landings. [0023] According to a preferred embodiment of the present invention, the CMDP can be used to neutralize distant targets. [0024] According to a preferred embodiment of the present invention, the CMDP can be used to reduce and eliminate casualties. [0025] According to a preferred embodiment of the present invention, the CMDP can be used to keep the enemy at bay. [0026] According to a preferred embodiment of the present invention, the CMDP can be used to neutralize large enemy forces. BRIEF DESCRIPTION OF THE DRAWINGS [0027] The invention is herein described by way of: an illustrated modified shell shown in FIG. 1 and the tested CMD schematic circuit shown in FIG. 3 : [0028] FIG. 1 , is a diagrammatic cross-section of a projectile according to one embodiment of the present invention wherein the projectile is a modified shell; [0029] FIG. 1 e , is a cross-section diagram showing the pressure switch in said projectile according to one embodiment of the preferred invention; [0030] FIG. 1 i , is a diagrammatic cross-section showing the Cruise Munitions Detonator (CMD) location in the projectile according to one embodiment of the preferred invention; [0031] FIG. 2 , is a diagram of the modified shell base plate according to an embodiment of the preferred invention; [0032] FIG. 2A , is a diagram of the seal and metal data ring according to one embodiment of the preferred invention; [0033] FIG. 2B , is a diagram of the data wire feeding into the seal according to one embodiment of the preferred invention; [0034] FIG. 3 , is the CMD circuit schematic according to one embodiment containing the pressure switch; memory data storage circuitry; counting and comparator circuitry; safe distance circuitry, and detonation enabling circuitry; [0035] FIG. 4 , is a diagram of a tank according to one embodiment; firing CMDPs into the mist of a large enemy force. [0036] FIG. 5 , is a diagram of CMDPs being fired into a reinforced bunker on a mountaintop and detonating in mid-air according to another embodiment of the preferred invention; [0037] FIG. 6 , is a diagram of CMDPs being fired according to one embodiment taking out enemy positions concealed along a mountaintop ridge; [0038] FIG. 7 , is a diagram of a CMDP according to one embodiment, detonating over the enemy in a crater; [0039] FIG. 8 , is a diagram of a helicopter according to one embodiment, defending against shoulder launched missiles using CMDPs; [0040] FIG. 9 , is a diagram of multi CMDPs according to one embodiment, defending against larger enemy formations; [0041] FIG. 10 a & 10 b , are diagrams of the Munitions Timer Input & Output Timing Chart according to one embodiment of the preferred invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0042] The present invention pertains to a projectile that detonates in mid-air after traveling along a programmed flight path and predetermined distance. The flight path of the projectile is determined by the operator or guidance system and is maintained in flight by its initial velocity. Specifically, the present invention can be used to neutralize larger enemy forces; combatants hiding behind objects or strategically placed combatants on the battlefield. The CMDP can also be fired from any aircraft or helicopter as an anti SAMS device, anti shoulder rocket device or anti air-to-air missile device. It would work well in neutralizing incoming mortar rounds in mid-air before they ever strike the ground. It can be deployed on aircraft as an excellent anti dog fighting weapon. Operating as an anti projectile eliminator, each system will use a radar or laser tracking system: electronic distance measuring, and calculating software (firmware) and an aiming device. The CMDP can be used to destroy moving or stationary targets. The CMDP allows one tank to fully engage larger size troop threats with efficient use of munitions, which means that the CMDP is a force multiplier. Modified Shell [0043] For the purpose of the present description and appended claims, by way of modified shell design (example only): [0044] A surface groove is symmetrically cut into and around the base plate as shown in FIG. 2 , and a small hole is drilled through the base plate within the path of the groove. The groove is deep enough to overlay the seal and metal data ring and remain flush with the surface of the base plate. FIG. 2A , shows a small AWG insulated wire attached to the stem of the data ring. The wire is aligned with the seal and pushed through the opening in the seal and into the shell as shown in FIG. 2B . The seal insulates the metal data ring from the shell's metal base plate. An insulated ground wire is soldered and insulated onto the inside of the shell and terminates into an insulated plug along with the data wire inside the shell see FIG. 1 b . The shell is then filled to a predetermined level with propellant (not shown) FIG. 1 g . A thin curve plate in FIG. 1 f , is placed over the propellant with the plug on top. An insulation material or foam is than used to insulate the plug from the other components (not shown). The pressure switch rests on top of a thin plate and makes contact as shown in FIG. 1 e. [0045] The base plate of a shell is modified (modified shell) to allow data to be transferred to the CMDP's memory. The CMDP's internal wires terminate into plug PI, as shown in FIG. 1 d. [0046] A cylinder is fastened to the center of the CMDP circuitry housing. The cylinder houses the pressure switch wires and data link wire. The detonator (not shown) is placed in the cylinder as shown in FIG. 1 h . The munitions type (not shown) is placed around the cylinder and filled to a predetermined level see FIG. 1 i . FIG. 1 j , shows the CMDP circuitry (CMD) housing. The nose cone is secured onto the projectile see FIG. 1 k. CMDP Circuitry Schematic (CMD) [0047] For the purpose of the present description and appended claims, by way of schematic circuitry design (tested); the present invention describes the CMD electronic schematic and refers to components, operations and functions in FIG. 3 . The schematic diagram also shows an array of circuit components interfaced to create block circuit operations needed to make the CMD work. [0048] The CMD is supplied voltage via switch s 4 , shown (lower left). The activation of s 4 simultaneously resets all onboard circuits via IC 4 A and IC 4 C (left center). The CMD is not limited to a manual power switch to power on, reset or power off the CMDP, it can also be equipped with an automatic power switching circuit that will accomplish the same function using an input code. Using an input code to control power to the CMD has many advantages. [0049] A sync pulse initiates and prepares the data link input circuit for incoming data. Afterwards, data words are stored into memory via the data link input and IC 8 B (center). Data initially enters into memory via IC 8 B, which is immediately disabled after the data is received and tansferred. IC 14 B, IC 6 B, IC 8 D, and CTX (center down) together create a block circuit for data synchronization for incoming data to be stored into memory chips IC 2 , IC 3 and IC 7 B (center right). A security code, IC 7 A pin 11 simultaneously transfers memory to buss B, enables IC 10 B (left center) and disables IC 8 B. IC 10 B enables IC 8 C (upper left) and IC 12 (lower right). The CMD is now ready for the CMDP to be fired from the gun. [0050] After the shell is fired, the combustion impacts the pressure switch enabling IC 10 A (upper left) to change states. IC 10 A (upper left) and the comparator circuit IC 11 , 5 & 12 (right) are enabled by the launch. ICIOA enables IC 6 A, U 1 and IC 13 B (upper center). IC 6 A controls the safety distance required for the projectile to travel before arming (enabling) one of two safety states for IC 8 A and IC 16 (upper center). U 1 initiates a continuous output pulse signal into IC 15 A to control IC 1 . IC 15 A is controlled by IC 8 A to increment and transfer data to buss A through IC 1 and IC 9 . IC 11 , IC 5 and IC 12 compare buses A and B. As the circuit computes the distance, the CMDP travels to the target area. If buss A equals buss B, IC 11 enables IC 13 A, then IC 13 A latches and arms the second IC 16 A safety detonating states. The detonation circuit changes states and detonates the munitions. [0051] Many safety latch states are built into the circuitry to prevent faulty detonation. All aspects of the CMD circuitry activates only if pre-conditions are met. [0000] Munitions Timer input & Output Timing Chart [0052] FIGS. 10 a & 10 b refers to the waveforms for the input clock and CMD timing and state changes at: IC 7 A- 11 , IC 8 B- 6 , IC 8 C- 9 , IC 8 C- 8 , IC 6 A- 2 , IC 6 A- 4 , IC 13 - 16 , IC 13 - 12 , IC 8 A- 2 and IC 8 A- 3 . Clock 1 , refers to the input clock frequency of the input device, and Clock 2 , refers to the clock frequency of the CMD. The frequencies for both units are the same and use SYNCH to synchronized them for data input transfer. Also, all timing signals depend on the clock operating frequency for operation. CMDP Operation, Functionality and Purpose [0053] For the purpose of the present description and appended claims, by way of operation, functionality and purpose; a CMDP fired from a gun will travel a predetermined distance and upon arriving at the designated distance will detonate. The present invention relates to the firing of a shell (projectile), from a gun, gun of a tank or modified grenade launcher, which detonates accurately along a fight path at, above or beside a target from a predetermined distance. A gun equipped with a laser range finder acquires the distance to the target and downloads the data into the projectile's electronic memory with only a touch of a button while the (projectile) shell is still inside the gun. Alternately, a gun equipped with a range dialer selects a distance to a target area and downloads the data into the projectile's electronic memory with a touch of the trigger while the projectile/shell is still inside the gun. Instantaneously, as the propellant inside the shell ignites and burns; it launches the projectile. The combustible force inside the shell impacts the pressure switch FIG. 1 e , activating and initiating the counter circuitry onboard the CMDP. As the projectile exits the gun and travels downrange towards the target, it clears a predetermined safe distance before enabling one of two munitions detonation safety states. This feature assures friendly forces are well outside the impact zone before target detonation. Also, simultaneously to the projectile's launch, the counter circuit initiates counting while still inside the gun and continues counting and comparing memory data until it reaches the target and detonates. After the memory and counter data compares and matches; a second safety detonator state enables and detonates the munitions. [0054] The projectile's flight is totally dependant on direction and height, initial velocity and the aiming mechanism of the gun. The CMDP used in a modified grenade launcher can simultaneously download data into memory and trigger the gun. Although the laser range finder may be the optimum choice to select a distant target, a range dial selection mode can be used in conjunction to rapidly engage the same distant target or newly acquired distant targets. Additional range can be added or subtracted from the range finder data to assure exact target detonation anywhere along the CMDP's flight path. The CMDP is a fire and forget device; is not dependant on target impact and will detonate upon reaching its predetermined range. After the first projectile is fired, the user can engage another target using the same range data or newly acquired data. The CMDP is self-contained and requires no additional signaling source after launching to acquire the target. The CMDP can be fitted with many types of munitions; white phosphorus, illumination, high explosive, smoke, fragmentation and cluster munitions or any number of munitions in the military's inventory. This new technology will dominate battles, minimize friendly causalities and reduce the duration of wars. [0055] Although the invention has been shown and described with respect to a certain preferred embodiment, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications and is limited only by the scope of the claims above.

A projectile, (Cruise Munition Detonator Projectile or CMDP), can be fired from a tank, modified grenade launcher or gun using a laser range finder, radar or manual input (dialer or keypad) range selector. The CMDP will prevent, neutralize and eliminate enemy close infighting. The CMDP can defend aircraft against SAM, shoulder launched missiles, and air-to-air missiles. The CMDP will travel a predetermined programmed distance and detonate in front of or behind, over or beside, or in the mist of a target. The CMDP allows small forces to strategically neutralize larger forces with devastating effect. The CMDP is a force multiplier and an anti-personnel weapon.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a light deflector for scanning an original image or a photosensitive member with a beam of light irradiated from a laser light source, for example, in an image reading system of a digital copying machine, a facsimile or a like apparatus or an image writing system of a laser beam printer or a like apparatus. 2. Description of the Related Art Conventionally, in a reading system for an original image, a method of irradiating a beam of light upon an original image to scan the original image to obtain density information for individual picture elements from reflected light is known, and in a writing system for a recording image, another method of irradiating a beam of light, which is modulated in accordance with picture information, upon a photosensitive member to scan the photosensitive member to form an electrostatic latent image is known. In both systems, an optical scanning system which employs a light deflector including a polygon mirror is known as a system for scanning an original image or a photosensitive member with a beam of light irradiated from a laser light source. FIG. 8 is a schematic view showing an image writing system which employs such scanning system. Referring to FIG. 8, the image writing system shown includes a laser light source 100, a collimator lens 101, a light deflector 102 including a polygon mirror 102a, an f-θ lens 103, and a photosensitive drum 104. A beam of light irradiated from the laser light source 100 is reflected by a reflecting mirror face of the polygon mirror 102a and introduced to the photosensitive drum 104. Thereupon, the beam of light is deflected by the polygon mirror 102a as the polygon mirror 102a rotates in the direction indicated by an arrow mark A so that it scans the photosensitive drum 104 along the direction indicated by an arrow mark B. Meanwhile, the photosensitive drum 104 rotates in the direction indicated by an arrow mark C, and a two-dimensional electrostatic latent image is formed on the photosensitive drum 104. Conventionally, a light deflector which is used for such an application as described above is disclosed in Japanese Patent Laid-Open Application No. Sho 59-23324 and Japanese Utility Model Laid-Open Application No. Hei 3-81915. In particular, the light deflector is constructed such that a rotary member is supported for rotation on a fixed shaft mounted uprightly on a housing while a polygon mirror is secured to a mirror flange formed on the rotary member and is rotated together with the rotary member by a motor section incorporated in the housing. Further, in the conventional light deflector, the polygon mirror is pressed against the mirror flange by a mirror cap screwed on an outer periphery of the rotary member and is thus held and fixed between and by the mirror cap and the mirror flange. In the conventional light deflector, however, since the mirror cap is screwed directly on the rotary member, if the mirror cap is fastened tightly to the rotary member in order to fix the polygon mirror with security, then the rotary member is compressed toward the inner side, resulting in the following problem. In particular, in light deflectors in recent years, in order to satisfy the demands for an increase of the speed of rotation and a decrease of vibrations of a polygon mirror and so forth, a dynamic pressure pneumatic bearing is employed to support the rotary member in a contactless condition on the fixed shaft. In this instance, since the gap (hereinafter referred to as bearing clearance) between the fixed shaft and the rotary member is only approximately 3 mm, if the rotary member is compressed toward the inner side, then the fixed shaft and the rotary member are brought into contact with each other, and consequently, rotation of the polygon mirror is disturbed. Or, even if the fixed shaft and the rotary member are not contacted with each other, if the bearing clearance varies, then rotation of the rotary member becomes non-uniform, resulting in non-uniform rotation of the polygon mirror. SUMMARY OF THE INVENTION It is an object of the present invention to provide a light deflector wherein a polygon mirror can be fixed firmly on a rotary member without disturbing smooth rotation of the polygon mirror. In order to attain the object described above, according to the present invention, there is provided a light deflector, which comprises a polygon mirror having a plurality of reflection mirror faces formed on an outer periphery thereof, a rotary member rotating at a predetermined speed and including an annular flange to which the polygon mirror is secured, a screw member having a male thread formed thereon and fitted on an outer periphery of the rotary member, and a mirror cap screwed with the screw member to press the polygon mirror against the mirror flange to secure the polygon mirror to the rotary member. In the light deflector, the rotary member may have any configuration only if it rotates smoothly holding the polygon mirror thereon, and for example, it may be a sleeve which rotates around the fixed shaft by way of a bearing or may be a rotary shaft which rotates at the center of a fixed sleeve by way of a bearing. Meanwhile, the mirror flange may be formed integrally with the rotary member or may be formed as a separate member from the rotary member and fitted on the outer periphery of the rotary member only if it is provided projectingly on the outer periphery of the rotary member and supports the polygon mirror thereon. Further, in the construction described above, when the mirror cap is fastened to the screw member, a compressing force acts in a radial direction of the screw member. In order to prevent the compressing force to be transmitted to the rotary member, preferably the screw member has a Young's modulus lower than that of the rotary member. By the way, when the rotary member rotates at a high speed, it is supposed that a centrifugal force acts upon the polygon mirror and that the temperatures of the polygon mirror, the screw member, the mirror cap and the mirror flange may be raised high due to heat generation by a motor section for driving the rotary member or by shearing frictional heat of air. Accordingly, in order to prevent such a situation as much as possible that the polygon mirror held between the mirror cap and the mirror flange is deformed by the centrifugal force or thermal expansion to cause distortion of the reflection mirror faces of the polygon mirror for a beam of light, preferably the Young's modulus and/or the coefficient of thermal expansion of the screw member are substantially equal to that or those of the polygon mirror. In this instance, preferably the Young's modulus and/or the coefficient of thermal expansion of the screw member are substantially equal to that or those of the mirror cap. Further preferably, the Young's modulus and/or the coefficient of thermal expansion of the mirror flange are substantially equal to those of the mirror cap and the screw member. Preferably, the coefficients of the mirror flange and/or the mirror cap are substantially equal to that of the polygon mirror. Preferably, the Young's modulus of the mirror flange and/or the mirror cap are substantially equal to that of the polygon mirror. Preferably, the mirror flange has an outer profile substantially same as or similar to that of the polygon mirror. Preferably, the light deflector further comprises a pressure adjustment member disposed between the polygon mirror and the mirror cap and having a Young's modulus substantially equal to or lower than that of the polygon mirror. In this instance, preferably the pressure adjustment member has a coefficient of linear expansion substantially equal to that of the polygon mirror. The pressure adjustment member may have a plurality of holes or a plurality of radial slits formed therein or may have a hollow structure. With the light deflector, since the screw member on which the male thread is formed is fitted on the outer periphery of the rotary member and the mirror cap which cooperates with the mirror flange to hold and secure the polygon mirror therebetween is screwed on the screw member, the compressing force by fastening of the mirror cap does not act directly upon the rotary member. Consequently, smooth rotational motion of the rotary member is assured while preventing non-uniform rotation of the rotary member, and the polygon mirror can be secured firmly on the rotary member without disturbing smooth rotation of the polygon mirror. The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference characters. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic axial sectional view of a light deflector showing a first preferred embodiment of the present invention; FIG. 2 is a transverse sectional view showing a motor of the light deflector shown in FIG. 1; FIG. 3 is a perspective view as viewed from above showing a mirror cap of the light deflector shown in FIG. 1; FIG. 4 is a perspective view as viewed from below showing the mirror cap shown in FIG. 3; FIG. 5 is a perspective view showing a screw member of the light deflector shown in FIG. 1; FIG. 6 is a schematic axial sectional view of another light deflector showing a second preferred embodiment of the present invention; FIG. 7 is a similar view but showing a third preferred embodiment of the present invention; FIG. 8 is a schematic perspective view showing an exemplary arrangement employing a light deflector; FIG. 9 is a schematic axial sectional view of a still further light deflector showing a fourth preferred embodiment of the present invention; FIG. 10 is a plan view of a pressure adjustment member employed in the light deflector shown in FIG. 9; FIGS. 11 and 12 are similar views but showing pressure adjustment members of different forms; and FIG. 13 is a cross sectional view showing a further different pressure adjustment member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, there is shown a light deflector according to a first preferred embodiment of the present invention, The light deflector shown includes a polygon mirror 1 having eight reflection mirror faces la on an outer periphery thereof, a rotary sleeve 2 for holding the polygon mirror 1 for integral rotation thereon, a mirror flange 3 provided projectingly on the rotary sleeve 2, a screw member 4 fitted on an outer periphery of the rotary sleeve 2, and a mirror cap 5 for being screwed on the screw member 4 to cooperate with the mirror flange 3 to hold the polygon mirror 1 therebetween. The rotary sleeve 2 is loosely fitted on a fixed shaft 7 mounted uprightly on a housing 6 with a predetermined gap (hereinafter referred to as bearing gap) left therebetween. The rotary sleeve 2 and the fixed shaft 7 thus construct a dynamic pressure pneumatic bearing for a radial direction. In particular, a plurality of dynamic pressure generating grooves 7a are formed in a herringbone pattern an an outer periphery of the fixed shaft 7, and when the rotary sleeve 2 rotates, a pneumatic dynamic pressure is generated in the bearing gap so that the rotary sleeve 2 is supported by an air lubrication film of a high pressure and rotates in a contactless condition around the fixed shaft 7. It is to be noted that, while the dynamic pressure generating grooves 7a in the present embodiment are formed on the outer periphery of the fixed shaft 7, such dynamic pressure generation grooves may alternatively be formed on an inner periphery of the rotary sleeve 2. The light deflect shown in FIG. 1 further includes a motor 8 for driving the rotary sleeve 2 to rotate. The motor 8 includes a rotor section 8a secured to an outer periphery of the rotary sleeve 2, and a stator section 8b secured to the housing 6. The rotor section 8a includes an annular inner magnet 9 and an annular outer magnet 10, which are securely mounted in a magnet yoke 11. Referring particularly to FIG. 2, the magnets 10 and 9 are disposed on an outer periphery and an inner periphery, respectively, of a stator core 12, which will be hereinafter described, and are each magnetized with four poles disposed at equal distances along a circumference. Each opposing ones of the magnetic poles of the magnets 9 and 10 across the stator core 12 have a same polarity. A magnetic attracting force always acts between the inner magnet 9 and the stator core 12 and between the outer magnet 10 and the stator core 12, and the magnets 9 and 10 and the stator core 12 cooperate with one another to construct a magnetic thrust bearing. In particular, if the mirror flange 3 is displaced in a thrust direction (axial direction of the fixed shaft) from a predetermined position, then the rotary sleeve 2 is drawn back by the magnetic attracting forces described above to the predetermined position at which the magnets 9 and 10 and the stator core 12 oppose regularly to each other, and the rotary sleeve 2 is always held at the predetermined position in the thrust direction. Meanwhile, the stator section 8b includes the stator core 12 supported on a stud 13 mounted uprightly on the housing 6, and electromagnetic coils (not shown) are wound each in a troidal shape around the stator core 12. A plurality of circuit board 15 are secured to the stator core 12 each by way of a stud 14, and the electromagnetic coils are connected to wiring lines printed on the circuit board 15. The circuit board 15 is connected to a control circuit section not shown by way of a wire 16 and a connector 17. The directions of electric currents to be supplied to the electromagnetic coils are determined in accordance with a detection signal of a magnetic detection sensor 18 mounted uprightly on the circuit board 15. In particular, the magnetic detection sensor 18 detects leakage fluxes of the inner magnet 9 and the outer magnet 10 of the rotor section 8a and transmits the detection signal to the control circuit section mentioned above. The control circuit section thus determines from the detection signal whether the magnetic poles of the inner magnet 9 and the outer magnet 10 which have passed the magnetic detection sensor 18 are the N poles or the S poles, and determines the directions of electric currents to be supplied to the electromagnetic coils wound at several locations of the stator core 12. As a result, a force always acts in a direction to continue the rotation of the rotary sleeve 2 between the electromagnetic coils and the magnets 9 and 10 so that a predetermined speed of rotation is provided to the rotary sleeve 2. Subsequently, mounting of the polygon mirror 1 onto the rotary sleeve 2 will be described. The polygon mirror 1 has a center hole formed therein which has an inner diameter a little greater than the outer diameter of the screw member 4, and the polygon mirror 1 is carried on the mirror flange 3 with the screw member 4 fitted in the center hole. The mirror cap 5 screwed on the screw member 4 contacts with the top of the polygon mirror 1 to press the polygon mirror 1 against the mirror flange 3. Referring now to FIG. 3, an annular balance adjustment groove 22 is formed at the top of the mirror cap 5, and a ballast or ballasts are suitably secured to the balance adjustment groove 22 to assure well balanced rotation of the polygon mirror 1. Further, a suitable number of connection holes 23 adapted to receive a jig for exclusive use (not shown) are formed at the top of the mirror cap 5 so that the mirror cap 5 may be tightened into the screw member 4 by means of the jig fitted in the connection holes 23. Meanwhile, the bottom face of the mirror cap 5 which contacts with the polygon mirror 1 is formed as a flattened face, and from the point of view of preventing loosening of the mirror cap 5 tightened to the screw member 4, preferably the bottom face of the mirror cap 5 has knurled grooves 24 formed thereon as shown in FIG. 4. The screw member 4 in which the mirror cap 5 is screwed is securely mounted on the outer periphery of the rotary sleeve 2 by force fitting or adhesion. Referring to FIG. 5, a male thread 25 with which the mirror cap 5 is screwed is formed on the outer periphery of the screw member 4, and several recessed grooves 26 for filling a bonding agent therein are formed on the male thread 25. Therefore, if the mirror cap is screwed with a bonding agent filled in the recessed grooves 26, then loosening of the mirror cap 5 tightened to the screw member 4 is prevented. Referring back to FIG. 1, in a condition wherein the mirror cap 5 is screwed on the screw member 4, an air room 19 is formed between the top end of the fixed shaft 7 and the mirror cap 5 to prevent damping in the thrust direction. The air room 19 is communicated with the external air by way of a fine hole 20 in order to stabilize the damping effect. A damper 21 is disposed on the housing 6 below the rotary sleeve 2 so as to prevent possible contact between the rotary sleeve 2 and the housing 6 when the rotary sleeve 2 is in a stopping condition or when an external force acts upon the rotary sleeve 2 during rotation. Further, in the present embodiment, the rotary sleeve 2 is formed from, for example, a ceramics material. Meanwhile, the polygon mirror 1 is formed from aluminum, and the screw member 4 is formed from aluminum which has a Young's modulus lower than that of the rotary sleeve 2 but substantially equal to that of the polygon mirror 1 and has a coefficient of thermal expansion substantially equal to that of the polygon mirror 1. In the present embodiment, the polygon mirror 1 is formed from aluminum and has a coefficient of thermal expansion of 23×10 -6 /deg and a Young's modulus of 7,500 kgf/mm 2 . Also the mirror flange 3 and the mirror cap 5 are formed from aluminum. In other words, the coefficients of thermal expansion and the Young's moduli of the mirror flange 3 and the mirror cap 5 are set substantially equal to those of the polygon mirror 1. Accordingly, even if thermal energy generated from the motor 8 flows into the polygon mirror 1, the mirror flange 3 and the mirror cap 5 to raise the temperatures of them high, since the coefficient of thermal expansion of the polygon mirror 1 in a radial direction is substantially equal to those of the mirror flange 3 and the mirror cap 5 between which the polygon mirror 1 is held, compressive stress or tensile stress is not generated in the polygon mirror 1, and consequently, distortion of the reflection mirror faces 1a by deformation of the polygon mirror 1 can be suppressed. Further, since the Young's moduli of the mirror flange 3 and the mirror cap 5 are set higher than that of the polygon mirror 1, even if the polygon mirror 1 tends to be deformed in a radial direction by a centrifugal force, the mirror flange 3 and the mirror cap 5 between which the polygon mirror 1 is held suppresses such possible deformation. Consequently, also in this regard, distortion of the reflection mirror faces 1a can be suppressed. In the light deflector of the present embodiment having the construction described above, since the polygon mirror 1 is held and fixed between and by the the mirror flange 3 and the mirror cap 5 by fastening the mirror cap 5 to the screw member 4, the polygon mirror 1 is deformed substantially uniformly without being locally deformed by a centrifugal force or heat generated by rotation of the polygon mirror 1. As a result, distortion of the reflection mirror faces 1a of the polygon mirror 1 is suppressed, and otherwise possible deterioration of the accuracy in reflection direction of a beam of light incident to the reflection mirror faces 1a, that is, deterioration of the accuracy of the angle by which a beam of light scans a photosensitive member or an original, can be prevented. Further, it has been confirmed by the inventors that, if the screw member 4 and the mirror cap 5 are tightened to each other with the fastening torque of 1 kgcm to 10 kgcm, then the distortion of the reflection mirror faces 1a can be suppressed to such a degree at which it has no influence on scanning of a photosensitive member or the like. Further, since the mirror cap 5 is screwed on the screw member 4 fitted on the outer periphery of the rotary sleeve 2, the compressing force in a radial direction generated by fastening of the mirror cap 5 is damped by the screw member 4 so that the compressing force can be prevented from acting upon the rotary sleeve 2 as much as possible. In addition, in the present embodiment, since the Young's modulus of the mirror cap 5 is lower than that of the rotary sleeve 2, the compressing force mentioned above is absorbed effectively by the screw member 4. Accordingly, even if the mirror cap 5 is tightened firmly, the rotary sleeve 2 and the fixed shaft 7 do not contact with each other, and such a situation that the bearing gap between the fixed shaft 7 and the rotary sleeve 2 varies to make rotation of the rotary sleeve 2 unstable does not occur. Consequently, the polygon mirror 1 can rotate stably. Further, in the present embodiment, since the Young's modulus and the coefficient of thermal expansion of the screw member 4 are substantially equal to those of the polygon mirror 1, even if a centrifugal force or heat acts upon the polygon mirror 1 and the screw member 4, they exhibit substantially equal amounts of deformation to each other, and consequently, the reflection mirror faces 1a of the polygon mirror 1 can be prevented from being distorted by an influence of a centrifugal force or heat. Further, if, in the present embodiment, the mirror cap 5 which presses the polygon mirror 1 against the mirror flange 3 has a Young's modulus and a coefficient of thermal expansion substantially equal to those of the polygon mirror 1 and the screw member 4, then the mirror cap 5 and the mirror flange 3 do not compress the polygon mirror 1 excessively by an influence of a centrifugal force or heat, and consequently, otherwise possible distortion of the reflection mirror faces 1a can be prevented further effectively. Referring now to FIG. 6, there is shown a light deflector according to a second preferred embodiment of the present invention. The present light deflector is a modification to and includes several common components to those of the light deflector of the first embodiment described above, and overlapping description of the common components will be omitted herein to avoid redundancy. This also applies to the other embodiments which will be hereinafter described. The present light deflector is different from the light deflector of the first embodiment in that a mirror flange 30 on which the polygon mirror 1 is supported is formed as a separate member from the rotary sleeve 2 and force fitted in the rotary sleeve 2. The mirror flange 30 has a Young's modulus and a coefficient of thermal expansion substantially equal to those of the polygon mirror 1, the screw member 4 and the mirror cap 5 so that the mirror cap 5 and the mirror flange 30 may not compress the polygon mirror 1 excessively by an influence of a centrifugal force or heat. Consequently, otherwise possible distortion of the reflection mirror faces 1a can be prevented further effectively. Referring now to FIG. 7, there is shown a light deflector according to a third preferred embodiment of the present invention. Also the present light deflector is a modification to and different from the light deflector of the first embodiment in that a polygon mirror securing sleeve 31 on which a male thread portion 31a with which the mirror cap is screwed and a mirror flange 31b are formed integrally is force fitted in the rotary sleeve 2 and the polygon mirror 1 is secured to the polygon mirror securing sleeve 31. The polygon mirror securing sleeve 31 has a Young's modulus and a coefficient of thermal expansion substantially equal to those of the polygon mirror 1 so that the mirror cap 5 and the mirror flange 31b may not compress the polygon mirror 1 excessively by an influence of a centrifugal force and heat. Consequently, otherwise possible distortion of the reflection mirror faces la can be prevented effectively. Referring now to FIG. 9, there is shown a light deflector according to a fourth preferred embodiment of the present invention. Also the present light deflector is a modification to the light deflector of the first embodiment. The present light deflector is different from the light deflector of the first embodiment in that a disk-shaped pressure adjustment member 27 is held between the polygon mirror 1 and the mirror cap 5. The pressure adjustment member 27 has a thickness of 0.1 mm and is formed from polyethylene terephthalate. The pressure adjustment member 27 has a center opening hole formed therein for fitting with the rotary sleeve 2 and the screw member 4. The polygon mirror 1 is formed from aluminum, and therefore, the pressure adjustment member 27 has a Young's modulus equal to or lower than that of the polygon mirror 1. Accordingly, when it is tried to tighten the mirror cap 5 to secure the polygon mirror 1, even if the pressing force acts locally upon the polygon mirror 1, the pressure adjustment member 27 disperses and absorbs the local pressing force, and consequently, local non-uniform concentrated stress is not generated in the polygon mirror 1 and otherwise possible distortion of the reflection mirror faces 1a of the polygon mirror 1 can be suppressed. The pressure adjustment member 27 may be formed from, in place of polyethylene terephthalate mentioned hereinabove, a polyphenyl ether resin, polyphenyl sulfide or polybutylene terephthalate. Further, if the pressure adjustment member 27 in this instance is formed from a material having a coefficient of linear expansion substantially equal to that of the polygon mirror 1, then the elongation of the pressure adjustment member 27 in a radial direction caused by a rise of temperature is substantially equal to that of the polygon mirror 1, and accordingly, local compressive stress or tensile stress is not generated in the polygon mirror 1. Also in this regard, distortion of the reflection mirror faces 1a of the polygon mirror 1 can be suppressed. Another pressure adjustment member is shown in FIG. 10. Referring to FIG. 10, the pressure adjustment member 40 shown has a plurality of holes 40b formed therein in addition to a center opening hole 40a so that it may efficiently disperse and moderate the pressing force of the mirror cap 5 acting on the polygon mirror 1. Accordingly, where the present pressure adjustment member 40 is employed, distortion of the reflection mirror faces 1a of the polygon mirror 1 can be suppressed further effectively. Meanwhile, a further pressure adjustment member 41 shown in FIG. 11 has a plurality of radial slits 41b formed therein in addition to a center opening hole 41a. The slits 41b correspond to outer angles of the polygon mirror 1. Also with the present arrangement, since the slits 41b are formed in the pressure adjustment member 41, the pressing force of the mirror cap 5 can be dispersed and moderated in conformity with the profile of the polygon mirror 1. A still further pressure adjustment member 42 shown in FIG. 12 has a plurality of elliptic slits 42b formed radially therein in addition to a center opening hole 42a. Also the present pressure adjustment member 42 may be formed in a polygonal shape having a number of outer angles equal to that of the polygon mirror 1. A yet further pressure adjustment member 43 shown in FIG. 13 is formed from a hollow material such as a tube shaped into an annular profile. The rotary sleeve 2 and the screw member 4 are fitted in a center opening hole 43a of the annular pressure adjustment member 43. A hollow portion 43b of the pressure adjustment member 43 is filled with air and is resiliently crushed in accordance with the pressing force of the mirror cap 5. Consequently, the pressure adjustment member 43 can efficiently disperse and moderate the pressing force to act upon the mirror cap 5, and distortion of the reflection mirror faces 1a of the polygon mirror 1 can be suppressed. Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein.

A light deflector wherein a polygon mirror rotating at a predetermined speed is used to deflect a beam of light irradiated from a laser light source to scan a photosensitive member or an original image with the deflected beam of light is improved in that the polygon mirror can be fixed firmly to the rotary member without disturbing smooth rotation of the polygon mirror. A screw member on which a male thread is formed is fitted on an outer periphery of the rotary member, and the polygon mirror is pressed against and secured to an annular mirror flange provided on the rotary member by a mirror cap screwed on the screw member.

BACKGROUND OF THE INVENTION [0001] The present invention relates to an information processing device. [0002] A digital device such as a personal computer and a printer is provided with a slot for transmitting and receiving data (image data) captured by a digital camera, a video camera, etc to and from the digital camera and the video camera. Further, for user's serviceability, a recording medium is attached and detached to and from the personal computer in a power-on status of a power source of a main body of the personal computer. [Patent document 1] Japanese Patent Application Laid-Open Publication No.2005-93381 SUMMARY OF THE INVENTION [0004] In the midst of writing the data to the recording medium, there is a case where the recording medium might be ejected from the personal computer. In this case, such a possibility arises that the original data as write target data might be destructed. Another possibility is that incomplete data interrupted in its writing might remain on the recording medium. It is therefore an object of the present invention to provide a technology capable of preventing the original data as the write target data from being destructed in the case of writing the data to the recording medium. It is another object of the present invention to provide a technology capable of preventing the incomplete data interrupted in its writing from remaining on the recording medium in the case of writing the data to the recording medium. [0005] The present invention adopts the following means in order to solve the problems. Namely, according to the present invention, an information processing device that writes data to an attachable/detachable recording medium comprises data segmenting means segmenting the data, data writing means writing the data segmented by the data segmenting means to the recording medium, and detecting means detecting ejection of the attached recording medium, wherein the data writing means stops writing when the detecting means detects the ejection of the recording medium. According to the present invention, in the case of detecting the ejection of the recording medium, the writing to the recording medium is stopped. It is therefore possible to prevent the original data as the write target data from being destructed. [0006] Further, the information processing device according to the present invention may further comprise deleting means deleting, when the detecting means detects the ejection of the recording medium, the data written by the writing means from the recording medium. According to the present invention, if the recording medium is ejected in the midst of writing the data to the recording medium, it is feasible to prevent the data interrupted in its writing from remaining on the recording medium. [0007] Moreover, the information processing device according to the present invention may further comprise means registering a write record of the data written to the recording medium by the data writing means in the data segmented by the data segmenting means, wherein the delete means deletes, based on the write record, the data written by the writing means from the recording medium. According to the present invention, the written data can be deleted from the recording medium by use of the write record of the data written to the recording medium. [0008] Further, the present invention may be a method by which a computer, other devices, machines, etc execute any one of the processes described above. Still further, the present invention may also be a program that makes the computer, other devices, machines, etc actualize any one of the functions described above. Yet further, the present invention may also be a recording medium recorded with such a program, which can be read by the computer etc. [0009] According to the present invention, the original write data can be prevented from being destructed in the case of writing the data to the recording medium. Further, according to the present invention, the incomplete data interrupted in its writing can be prevented from remaining on the recording medium in the case of writing the data to the recording medium. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 is a block diagram of pieces of hardware of a device body 1 . [0011] FIG. 2 is an explanatory diagram of an operation of a card slot 11 . [0012] FIG. 3 is an explanatory diagram of the operation of the card slot 11 . [0013] FIG. 4 is an explanatory diagram of the operation of the card slot 11 . [0014] FIG. 5 is an explanatory diagram of the operation of the card slot 11 . [0015] FIG. 6 is an explanatory diagram of the operation of the card slot 11 . [0016] FIG. 7 is an explanatory diagram of the operation of the card slot 11 . [0017] FIG. 8 is an explanatory diagram of an ejection detecting switch. [0018] FIG. 9 is an explanatory diagram of the ejection detecting switch. [0019] FIG. 10 is an explanatory diagram of an ejection detecting circuit. [0020] FIG. 11 is a diagram showing a connecting relationship between the card slot 11 , an EC 7 , a chip set 3 and a control unit 2 . [0021] FIG. 12 is a conceptual diagram explaining an operation when making a write request and an operation when interrupt occurs. [0022] FIG. 13 is a flowchart of an operation when starting up a filter driver 22 . DETAILED DESCRIPTION OF THE INVENTION [0023] An information processing device according to a best mode (which will hereinafter be termed an embodiment) for carrying out the present invention will hereinafter be described with reference to the drawings. A configuration in the following embodiment is an exemplification, and the present invention is not limited to the configuration in the embodiment. [0024] FIG. 1 shows a block diagram of pieces of hardware of a device body 1 provided in the information processing device. The device body 1 includes a control unit 2 , a chip set 3 , a ROM (Read Only Memory) 4 , a RAM (Random Access Memory) 5 , a recording unit 6 , an EC (Embedded Controller) 7 , a memory card controller 8 , an input unit 9 , an output unit 10 and a card slot 11 . The control unit 2 is exemplified such as a CPU (Central Processing Unit) and executes a variety of processes according to a program stored in the ROM 4 or the RAM 5 . The control unit 2 and the chip set 3 are connected to each other via a bus 12 A. The ROM 4 , the RAM 5 , the recording unit 6 , the EC 7 , the memory card controller 8 and the output unit 10 are connected via a bus 12 B to the chip set 3 . The input unit 9 is connected to the EC 7 . The chip set 3 controls connections to the respective units connected to the control unit 2 and to the chip set 3 . [0025] The ROM 4 is stored with a program required for the present information processing device to function and with parameters. The RAM 5 is temporarily stored with part of a program of operating system (OS) and an application program, which are executed by the control unit 2 . The recording unit 6 is employed as an external storage for the present information processing device. The EC 7 is connected via a signal line to the card slot 11 . The memory card controller 8 is connected via a signal line to the card slot 11 . The card slot 11 enables insertion of a memory card defined as a storage medium having a built-in semiconductor memory. [0026] The input unit 9 is exemplified such as a keyboard and a mouse, and is operated when inputting a predetermined command and a necessary item of data. The output unit 10 includes a display device such as a CRT (Cathode Ray Tube), a liquid crystal display and a plasma display, an audio output device such as a speaker, and an output device such as a printer device. [0027] Further, the information processing device in the present embodiment can be actualized as an information device such as a personal computer, a mobile information terminal and a mobile phone. [0028] Next, an operation of a card slot 11 included in the information processing device in the present embodiment will be explained. <Insertion of Memory Card> [0029] In the case of inserting the memory card 14 into the card slot 11 , the memory card 14 is pushed in a direction indicated by an arrowhead in FIG. 2 . As depicted in FIG. 3 , the memory card 14 is intruded up to an innermost portion within the card slot 11 . When the memory card 14 is intruded up to the innermost portion within the card slot 11 , the memory card 14 is returned to a position just anterior to the innermost portion within the card slot 11 . Then, as shown in FIG. 4 , the memory card 14 is locked in the position just anterior to the innermost portion within the card slot 11 . A locking function within the card slot 11 is broadly known, and therefore its explanation is omitted herein. [0030] The card slot 11 is provided with an unillustrated terminal for electrically connecting the memory card 14 to the card slot 11 . The memory card 14 is locked in the position just anterior to the innermost portion within the card slot 11 , and an unillustrated electrode provided on the memory card 14 is brought into contact with the terminal of the card slot 11 . The electrode provided on the memory card 14 is electrically connected to the terminal of the card slot 11 , thereby enabling the information processing device to access the memory card 14 . [0031] <Ejection of Memory Card> [0032] As illustrated in FIG. 5 , the memory card 14 is locked in the position just anterior to the innermost portion within the card slot 11 . In the case of ejecting the memory card 14 from the card slot 11 , the memory card 14 is pushed in a direction indicated by an arrowhead in FIG. 6 . When the memory card 14 is intruded up to the innermost portion within the card slot 11 , as depicted in FIG. 7 , the memory card 14 is ejected out of the card slot 11 . [0033] Next, the card slot 11 provided with an ejection detecting switch will be described. To begin with, the ejection detecting switch is provided on the card slot 11 . Specifically, as shown in FIG. 8 , the card slot 11 is connected to a signal line 13 and is further connected to a signal line 15 . [0034] As depicted in FIG. 8 , when the memory card 14 is locked in the position just anterior to the innermost portion within the card slot 11 , the signal line 13 is not brought into contact with the signal line 15 . As illustrated in FIG. 9 , when the memory card 14 is intruded up to the innermost portion within the card slot 11 , the signal line 13 is brought into contact with the signal line 15 . [0035] Next, an ejection detecting circuit will be explained. As shown in FIG. 10 , the signal line 13 is provided with a chattering removal circuit 16 . Further, the signal line 13 is provided with a Vcc power source 17 . Then, a resistance 18 is provided between the signal line 13 and the Vcc power source 17 . The chattering removal circuit 16 is constructed of a resistance 19 and a capacitor 20 . The chattering removal circuit 16 is a circuit that removes chattering of the signal received by the EC 7 via the signal line 13 . The signal line 13 is grounded. The capacitor 20 is provided between the signal line 13 and the ground. Further, the signal line 15 is grounded. Moreover, the signal line 13 is connected to the EC 7 . [0036] When the memory card 14 is locked in the position just anterior to the innermost portion within the card slot 11 , the signal line 13 and the signal line 15 are not brought into contact with each other. Hence, the EC 7 receives a High-level signal via the signal line 13 . [0037] When the memory card 14 is intruded up to the innermost portion within the card slot 11 , the signal line 13 and the signal line 15 are brought into contact with each other. Therefore, the EC 7 receives a Low-level signal via the signal line 13 . In the case of ejecting the memory card 14 out of the card slot 11 , the memory card 14 is intruded up to the innermost portion within the card slot 11 . In this case, the EC 7 receives the Low-level signal via the signal line 13 . [0038] The High- or Low-level signal received by the EC 7 via the signal line 13 is employed as an interrupt signal. Normally, a plurality of interrupt signals exists Therefore, the signal line 13 is connected not to the control unit 2 but to the EC 7 . Then, the High- or Low-level signal received by the EC 7 via the signal line 13 is transmitted to the control unit 2 via the chip set 3 . The interrupt signal received by the EC 7 via the signal line 13 is recorded in a register within the EC 7 . The Low-level signal recorded in the register within the EC 7 is set as a card ejection interrupt signal. [0039] FIG. 11 is a diagram showing a connecting relationship between the card slot 11 , the EC 7 , the chip set 3 and the control unit 2 . As depicted in FIG. 11 , a plurality of interrupt signal lines is connected to the EC 7 . One of the plurality of interrupt signal lines connected to the EC 7 is the signal line 13 . The EC 7 receives the interrupt signals via the plurality of interrupt signal lines. Then, the EC 7 transmits to the chip set 3 the interrupt signals received via the plurality of interrupt signal lines by use of the single signal line. The chip set 3 transmits the interrupt signals received from the EC 7 to the control unit 2 . [0040] Next, an operation in a case where writing to the memory card 14 occurs will be explained. FIG. 12 is a conceptual diagram that explains an operation when making a write request and an operation when the interrupt occurs. When the writing to the memory card 14 occurs, the OS (Operating System) 21 sends a file write request to a memory card driver 23 . Herein, a file is defined as an aggregation of data recorded in the recording unit 6 and stored in other storage devices. Further, the writing connotes transferring the data, copying the data and creating a new piece of data. [0041] When the OS 21 sends the file write request to the memory card driver 23 , for example, API (Application Program Interface) named “Write File” is used. [0042] Further, the file write request is given via a filter driver 22 to the memory card driver 23 from the OS 21 . Namely, when the OS 21 sends the file write request to the memory card driver 23 , the OS 21 sends the file write request to the filter driver 22 . Then, the filter driver 22 sends the file write request to the memory card driver 23 . [0043] The memory card driver 23 translates the file write request into a physical address of the memory card 14 . Namely, the memory card driver 23 , in the case of receiving the file write request, designates an address of a storage area of the write target memory card 14 . Moreover, the memory card driver 23 may also translate the file write request into a logical address of the memory card 14 . In this case, a controller within the memory card 14 translates the logical address into the physical address. [0044] The memory card controller 8 receives the file write request via the memory card driver 23 . To be specific, the memory card controller 8 receives the address designated by the memory card driver 23 . [0045] Then, the memory card controller 8 executes the writing to the memory card 14 inserted into the card slot 11 . [0046] Next, an operation when the interrupt occurs will be explained The control unit 2 , when receiving the interrupt signal, starts up BIOS (Basic Input/Output System) 26 . The BIOS 26 is stored (installed) in the ROM 4 . The BIOS 26 after being started up accesses the EC 7 . Then, the BIOS 26 analyzes an interrupt factor. Namely, the BIOS 26 judges whether the interrupt signal received by the control unit 2 is a card ejection interrupt signal or not. [0047] If the interrupt signal received by the control unit 2 is the card ejection interrupt signal, the BIOS 26 sends an interrupt message to an interrupt detecting driver 25 . In this case, the interrupt message is a message purporting that the interrupt occurs. The interrupt detecting driver 25 receiving the interrupt message sends the interrupt message to a monitor application 24 . Then, the monitor application 24 receiving the interrupt message sends the interrupt message to the filter driver 22 . The filter driver 22 receiving the interrupt message stops sending the write request to the memory card driver 23 . [0048] A detailed operation of the filter driver 22 will be described. FIG. 13 shows a flowchart of the operation when starting up the filter driver 22 . The operation of the filter driver 22 is actualized in such a way that the filter driver 22 is loaded into the RAM 5 and the control unit 2 controls the execution thereof. [0049] To start with, when the OS 21 makes the write request, the control unit 2 stores, in a queue, the write request target data as packet data (S 01 ). The queue is a storage area, provided in the RAM 5 , for storing the packet data. If there is a plurality of write request target files, it follows that there are plural pieces of packet data to be stored in the queue. [0050] Next, the control unit 2 acquires one piece of packet data stored in the queue (S 02 ). A scheme in this case is that none of the packet data acquired by the control unit 2 remains in the queue. [0051] Then, the control unit 2 clears a record of transmission (S 03 ). The record of transmission is a record showing completion of writing the write request target file. Further, the record of transmission is stored in the RAM 5 . The record of transmission corresponds to a “write record” according to the present invention. [0052] Next, the control unit 2 segments the packet data acquired from the queue (S 04 ). For instance, the control unit 2 segments the packet data by the unit of 100 bytes, which is acquired from the queue. In this case, the segmented packet data is assigned a unique number. Further, the unit for the packet segmentation can be arbitrarily set. [0053] Then, the control unit 2 transmits one of the segmented pieces of packet data (post-segmentation packet data) to the memory card driver 23 (S 05 ). [0054] Subsequently, the control unit 2 receives a completion message of the post-segmentation packet data transmitted to the memory card driver 23 (S 06 ). The completion message is a message representing that the memory card controller 8 completes the writing to the memory card 14 . [0055] Then, the control unit 2 registers, in the record of transmission, information about the post-segmentation packet data of which the completion message has been received (S 07 ). To be specific, the control unit 2 registers, in the record of transmission, the data number of the post-segmentation packet data of which the completion message has been received. [0056] Next, the control unit 2 judges whether there is the interrupt message or not (S 08 ). Namely, the control unit 2 judges whether or not the monitor application 24 sends the interrupt message to the filter driver 22 . [0057] If there is no interrupt message, the control unit 2 judges whether or not all the segmented packet data are transmitted to the memory card driver 23 (S 09 ). If all the segmented packet data are transmitted to the memory card driver 23 , the control unit 2 judges whether the packet data remains in the queue or not (S 10 ). If the packet data remains in the queue, the control unit 2 returns to the process in S 02 . Whereas if the packet data does not remain in the queue, the control unit 2 finishes the operation of the filter driver 22 . [0058] Moreover, if there is the interrupt message (if judged to be affirmative in the process in S 08 ), the control unit 2 sends to the memory card driver 23 a delete processing request of the packet data of which data number is registered in the record of transmission (S 11 ). Then, the memory card driver 23 transmits the delete processing request to the memory card controller 8 . The memory card controller 8 deletes the packet data with its writing completed out of the memory card 14 on the basis of the data number registered in the record of transmission. [0059] Next, the control unit 2 deletes all the packet data remaining in the queue (S 12 ). Further, the control unit 2 deletes all the segmented packet data. Thereafter, the control unit 2 finishes the operation of the filter driver 22 . [0060] Moreover, if all the segmented packet data are not transmitted to the memory card driver 23 (if judged to be negative in the process in S 10 ), the control unit 2 returns to the process in S 05 . Then, the processes in S 05 through S 10 are repeatedly executed till all the segmented packet data are transmitted to the memory card driver 23 . [0061] In the present embodiment, the write request target data is segmented and thus written to the memory card 14 . Then, each time the segmented data is written to the memory card 14 , it is judged whether the memory card 14 is ejected or not. If the memory card 14 is ejected, none of the data is written to the memory card 14 from this onward. [0062] If the writing of the data to the memory card 14 is completed before an elapse of ejection time, the write request target data is not destructed. The ejection time is a period of time expended till the memory card 14 is ejected from the card slot 11 since the memory card 14 has been intruded up to the innermost portion within the card slot 11 . [0063] In the present embodiment, the write request target data is segmented so that write time is shorter than the ejection time. The write time connotes a period of time elapsed till one of the segmented pieces of packet data is written to the memory card 14 since it has been judged whether the memory card 14 was ejected or not. [0064] For instance, if the ejection time is on the order of 40 msec, the write request target data is segmented, thereby reducing the write time down to 3 micro sec. In this case, even if the operation of ejecting the memory card 14 is started simultaneously with the start of the writing, the writing of the data to the memory card 14 is to be completed before the elapse of the ejection time. The values given above are, however, exemplifications, and the ejection time and the write time are not limited to the values given above. The ejection time and the write time are, it is sufficient, obtained from actual measurement or simulation. [0065] In the present embodiment, the write request target data is segmented and thus written to the memory card 14 , thereby making it possible to prevent the data from being destructed due to the ejection of the memory card 14 . [0066] Moreover, in the present embodiment, when ejecting the memory card 14 , in the segmented data, the data with its writing completed is deleted from the memory card 14 . As a result, any part of the segmented data can not remain in the memory card 14 . [0067] <Computer Readable Recording Medium> [0068] It is possible to record a program which causes a computer to implement any of the functions described above on a computer readable recording medium. By causing the computer to read in the program from the recording medium and execute it, the function thereof can be provided. The computer readable recording medium mentioned herein indicates a recording medium which stores information such as data and a program by an electric, magnetic, optical, mechanical, or chemical operation and allows the stored information to be read from the computer. Of such recording media, those detachable from the computer include, e.g., a flexible disk, a magneto-optical disk, a CD-ROM, a CD-R/W, a DVD, a DAT, an 8-mm tape, and a memory card. Of such recording media, those fixed to the computer include a hard disk and a ROM (Read Only Memory). <Others> [0069] The disclosures of Japanese patent application No. JP2006-074590 filed on Mar. 17, 2006 including the specification, drawings and abstract are incorporated herein by reference.

To prevent original data as a write target data from being destructed in the case of writing the data to a recording medium. An information processing device that writes data to an attachable/detachable recording medium includes data segmenting unit segmenting the data, data writing unit writing the data segmented by the data segmenting unit to the recording medium, and detecting unit detecting ejection of the attached recording medium, wherein the data writing unit stops writing when the detecting unit detects the ejection of the recording medium.

CROSS REFERENCE TO RELATED APPLICATIONS AND PRIORITY CLAIM [0001] This application claims priority to U.S. Provisional patent application Ser. No. 60/890,988, filed Feb. 21, 2007, which is incorporated by reference herein in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to transdermal delivery of a combination of dexamethasone and promethazine as well as pharmaceutical compositions, manufactures and methods of using the same. BACKGROUND OF THE INVENTION [0003] Nausea and vomiting are symptoms arising out of several different, unrelated physical conditions, many of which do not directly involve the stomach. Vomiting (emesis) is the forceful expulsion of stomach contents through the esophagus and mouth; nausea is the queasy feeling that one is going to vomit. There are various causes of nausea and vomiting. Motion sickness is a common form of nausea that may or may not include vomiting, which is caused by a difference in perception of motion between the inner ear and the eyes, often while riding some sort of mechanical conveyance, such as a car, an airplane or a boat. Morning sickness involves nausea and vomiting caused by hormonal fluctuations in pregnant women; it may be initiated or exacerbated by any of a variety of sensory cues, especially smells, some of which may actually seem pleasant to the same woman when she is not pregnant. Various drugs, other environmental stressors, migraine headaches, disease states and psychiatric conditions are also known to give rise to nausea and vomiting. [0004] While vomiting may, in some circumstances, serve the purpose of expelling harmful substances from the stomach, prolonged, frequent or severe vomiting is generally undesirable or even life threatening. Likewise, nausea is an uncomfortable feeling that may be accompanied by sweating, excessive salivating, chills or other unpleasant symptoms. Especially in the case of motion sickness, the cause of nausea and vomiting may be nearly or entirely benign, while the effects may range in severity from mildly uncomfortable to debilitating. Even where vomiting serves an initially salutary purpose, e.g. to expel a toxin from the body, continued or especially violent vomiting may be undesirable or deleterious to the patient. Several anti-nausea medications (broadly referred to as antiemetic drugs, or simply antiemetics) have been developed; but there are still patients who do not respond to the available antiemetics or are sensitive to, or demonstrate poor compliance with, current anti-nausea therapies. There is thus a need for a new and improved antiemetic drug. [0005] The invention meets the foregoing need and provides related advantages as well. SUMMARY [0006] The invention meets the foregoing need, and provides further advantages as well, by providing a pharmaceutical composition for transdermal drug delivery, comprising dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. The composition is adapted to deliver a combination of dexamethasone and promethazine across the skin. In some embodiments, the composition provides a therapeutically effective dose of a combination of dexamethasone and promethazine. In some particular embodiments, the composition is presented in unit dosage form. In some embodiments, the composition comprises an anti-emetic and/or anti-nausea effective amount of the combination of dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. In some embodiments, the composition further comprises a skin penetration enhancer. [0007] The foregoing and other needs are met by embodiments of the invention that provide a composition for transdermal drug delivery, comprising dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof, in admixture with a pharmaceutically acceptable transdermal delivery vehicle. In some embodiments, the composition is in unit dosage form. In some particular embodiments, the composition comprises an anti-emetic and/or anti-nausea effective amount of the combination of dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. In some embodiments, the composition further comprises a skin penetration enhancer. [0008] Further, the foregoing and other needs are met by embodiments of the invention that provide a composition for transdermal drug delivery, comprising dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof, in admixture with a pharmaceutically acceptable transdermal delivery excipient, adjuvant or penetration enhancer. In some embodiments, the composition is in unit dosage form. In some particular embodiments, the composition comprises an anti-emetic and/or anti-nausea effective amount of the combination of dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. Furthermore, the invention provides a transdermal patch comprising a therapeutically effective amount of dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. In some embodiments, the patch is selected from a single layer medicine in adhesive patch, a multi-layer medicine in adhesive patch, a reservoir patch, a matrix patch, a microneedle patch or an iontophoretic patch. [0009] The present invention also provides, in certain embodiments, a method of treating or preventing emesis in a subject, comprising transdermally administering to the subject a therapeutically effective amount of a combination of dexamethasone and promethazine or a pharmaceutically acceptable salt thereof. In some embodiments, the method comprises employing a therapeutically effective amount of dexamethasone and promethazine administered in admixture with a topically-applied vehicle. In other embodiments, the method comprises using a therapeutically effective amount of dexamethasone and promethazine administered as a transdermal patch. In still further embodiments, the transdermal patch is adapted for sustained release. [0010] The foregoing and further advantages are met by embodiments of the invention, which provide a kit comprising an antiemetically effective combination of dexamethasone and promethazine for transdermal administration. In some embodiments, the kit further comprises instructions for use of the combination of dexamethasone and promethazine as an antiemetic. In some particular embodiments, the invention provides a kit comprising a first patch comprising dexamethasone. Where a single patch is comprised within the kit, the patch contains a therapeutically effective amount of both dexamethasone and promethazine. Where more than one patch is contained within the kit, at least one patch contains dexamethasone and a second patch comprises promethazine. The combination of dexamethasone and promethazine in the two patches is therapeutically effective. In some embodiments, the first patch contains dexamethasone and the second patch contains promethazine. In particular embodiments, the first patch is substantially free of promethazine and the second patch is substantially free of dexamethasone. In other embodiments, one or both of the patches may contain a combination of promethazine and dexamethasone, so long as the combined dose in the two patches is a therapeutically effective combination of dexamethasone and promethazine. The kit may comprise multiple patches representing multiple doses. For example, the kit may comprise sufficient number of patches to provide 1 to about 30 days' worth of the combination of dexamethasone and promethazine, preferably 1 to about 10 days' worth, particularly about 1 to about 7 days' worth. [0011] The foregoing and further characteristics and advantages of the present invention are further described by the following detailed description of the invention. INCORPORATION BY REFERENCE [0012] All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. DETAILED DESCRIPTION OF THE INVENTION [0013] The invention meets the foregoing need and provides further advantages as well by providing a pharmaceutical composition for transdermal drug delivery, comprising dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. The composition is adapted to deliver a combination of dexamethasone and promethazine across the skin. In some embodiments, the composition provides a therapeutically effective dose of a combination of dexamethasone and promethazine. In some particular embodiments, the composition is presented in unit dosage form. In some embodiments, the composition comprises an anti-emetic and/or anti-nausea effective amount of the combination of dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. In some embodiments, the composition further comprises a skin penetration enhancer. [0014] Dexamethasone [0015] Dexamethasone [(11β,16α)-9-fluoro-11,17,21-trihydroxy-16-methylpregna-1,4-diene-3,20-dione] is a corticosteroid with the structural formula: [0000] [0016] Dexamethasone is a known corticosteroid, having anti-inflammatory and immune-suppressing activity. The present invention provides transdermal compositions containing an effective amount of a combination of dexamethasone and promethazine, optionally in admixture with one or more skin penetration enhancers, such as dimethylsulfoxide (DMSO). The present invention further provides a method of treating or preventing nausea or emesis in a patient in need of such therapy, comprising administering via a transdermal route of administration a therapeutically effective amount of a combination of dexamethasone and promethazine to the patient. In some embodiments, the transdermal route of administration comprises applying a patch capable of administering a therapeutically effective amount of a combination of dexamethasone and promethazine to the patient. In other embodiments, the transdermal route of administration comprises applying to a patient's skin a therapeutically effective amount of a transdermal solution or suspension, such as an ointment, cream, gel or lotion, comprising a therapeutically effective combination of dexamethasone and promethazine, and optionally comprising a skin penetration enhancer. [0017] Promethazine [0018] Promethazine (N,N,α-trimethyl-10H-phenothiazine-10-ethanaamine) is an antihistaminic compound having the formula: [0000] [0019] Promethazine is an antihistamine known to possess anti-allergy as well as antiemetic properties. In particular, promethazine has been used to treat motion sickness as well as post-operative (anesthesia-induced) nausea and vomiting. The present invention provides transdermal compositions containing an effective amount of a combination of dexamethasone and promethazine, optionally in admixture with one or more skin penetration enhancers, such as dimethylsulfoxide (DMSO). The present invention further provides a method of treating or preventing nausea or emesis in a patient in need of such therapy, comprising administering via a transdermal route of administration a therapeutically effective amount of a combination of dexamethasone and promethazine to the patient. In some embodiments, the transdermal route of administration comprises applying a patch capable of administering a therapeutically effective amount of a combination of dexamethasone and promethazine to the patient. In other embodiments, the transdermal route of administration comprises applying to a patient's skin a therapeutically effective amount of a transdermal solution or suspension, such as an ointment, cream, gel or lotion, comprising a therapeutically effective combination of dexamethasone and promethazine, and optionally comprising a skin penetration enhancer. [0020] The foregoing and other needs are met by embodiments of the invention that provide a composition for transdermal drug delivery, comprising dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof, in admixture with a pharmaceutically acceptable transdermal delivery vehicle. In some embodiments, the composition is in unit dosage form. In some particular embodiments, the composition comprises an anti-emetic and/or anti-nausea effective amount of the combination of dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. In some embodiments, the composition further comprises a skin penetration enhancer. [0021] Further, the foregoing and other needs are met by embodiments of the invention that provide a composition for transdermal drug delivery, comprising dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof, in admixture with a pharmaceutically acceptable transdermal delivery excipient, adjuvant or penetration enhancer. In some embodiments, the composition is in unit dosage form. In some particular embodiments, the composition comprises an anti-emetic and/or anti-nausea effective amount of the combination of dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. Furthermore, the invention provides a transdermal patch comprising a therapeutically effective amount of dexamethasone and promethazine, or a pharmaceutically acceptable salt thereof. In some embodiments, the patch is selected from a single layer medicine in adhesive patch, a multi-layer medicine in adhesive patch, a reservoir patch, a matrix patch, a microneedle patch or an iontophoretic patch. [0022] The present invention also provides, in certain embodiments, a method of treating or preventing emesis in a subject, comprising transdermally administering to the subject a therapeutically effective amount of a combination of dexamethasone and promethazine or a pharmaceutically acceptable salt thereof. In some embodiments, the method comprises employing a therapeutically effective amount of dexamethasone and promethazine is administered in admixture with a topically-applied vehicle. In other embodiments, the method comprises using a therapeutically effective amount of dexamethasone and promethazine is administered as a transdermal patch. In still further embodiments, the transdermal patch is adapted for sustained release. [0023] Transdermal Administration of Dexamethasone and Promethazine [0024] The present invention provides for the transdermal administration of a therapeutically effective amount of a combination of dexamethasone and promethazine. The phrase “Therapeutically effective” means that amount of the combination of dexamethasone and promethazine that is effective to treat or prevent nausea and/or vomiting. In this context, “to treat” nausea or vomiting means to reduce the intensity of nausea and/or vomiting, and includes complete alleviation of nausea or vomiting for a period of time. In the context of this invention, “to prevent” means to protect the patient from the onset of nausea and/or vomiting for a period of time. In some embodiments, the period of time for which the treatment or prevention is provided is from about 30 minutes to about 48 hours, especially about 1 hour to about 24 hour. In some specific embodiments, prevention or treatment is provided for about 3 hours, about 4 hours, about 6 hours, about 8 hours, about 12 hours, about 18 hours, about 24 hours, about 48 hours or about 72 hours. In other embodiments, e.g. where prevention or treatment is provided for acute onset nausea and/or vomiting, prevention or treatment may be for an indefinite time period. [0025] As used herein, all percent values relating to dexamethasone and promethazine are in units of % (weight of active per volume of solution, suspension or the like), unless otherwise specified. [0026] In the context of the present invention, the term “transdermal delivery” means delivery of the combination of dexamethasone and promethazine across the skin and into the bloodstream. Thus, in the context of the present invention, transdermal administration results in systemic administration of the combination of dexamethasone and promethazine, especially systemic administration that avoids the portal vein of the liver, thereby avoiding first-pass effects associated with dexamethasone and/or promethazine. [0027] Transdermal Patches [0028] Transdermal patches (also referred to as skin patches) are medicated adhesive patches designed to provide medication to a patient. Some advantages of transdermal release include simplicity of use and concomitantly increased patient compliance, avoidance of the portal vein and resulting avoidance of the first-pass hepatic metabolism of the drug due, and in some cases sustained release of the drug over time. In addition, each type of transdermal patch presents other advantages specific to that type of patch. [0029] Various transdermal patches are known in the art and considered suitable for practicing the present invention. The oldest known type of transdermal patches are the single layer patches, which comprise a patch substrate (or backing) and an adhesive, the latter of which contains the medication to be released into the patient. The patch is adhered to a detachable liner during storage; and the liner is removed and discarded prior to use. A layer of medication-containing adhesive is applied in one or more layers onto the substrate. The adhesive is adhered to the user's skin during use. Medication is released directly from the adhesive and through the skin into the patient's body. Thus, in some embodiments the invention provides a single layer transdermal adhesive patch, which comprises an adhesive in which the combination of dexamethasone and promethazine is dissolved. In some embodiments, the adhesive layer further comprises one or more penetration enhancers, which enhance the ability of dexamethasone, promethazine or both to penetrate the skin. [0030] Another type of known patch is the multiple-layered medication in adhesive patch. It too comprises a substrate and an adhesive that contains the medication. However, rather than being applied in a single layer, the adhesive is applied in multiple layers. In some cases, the multiple-layered patch further comprises a membrane that separates the multiple layers. In other cases, the membrane is omitted. In some cases, the membrane provides additional mechanical support for the additional layers of medicated adhesive. In other cases, the membrane provides a dampening effect on the release of at least some of the medication from the patch and into the body. In any case, the medication is mixed into the adhesive, from which it is released once the patch has been applied to the body. The layer of adhesive farthest from the substrate is adhered to the patient's body. Thus, in embodiments of the invention, there is provided a multiple-layered medication patch in which dexamethasone is provided in at least a first layer of the patch and promethazine is contained within at least a second layer of the patch. In some embodiments, at least some of the pharmaceutically effective amount of dexamethasone and promethazine is contained within the first layer. In some more particular embodiments, at least some of the pharmaceutically effective amount of dexamethasone and promethazine is contained within the second layer. In more particular embodiments of the invention, at least some of the pharmaceutically effective amount of dexamethasone and promethazine is contained within the first and second layers. In even more particular embodiments of the invention, the pharmaceutically effective amount of each of dexamethasone and promethazine is substantially evenly divided between the first and second layers. In some embodiments, the first layer, the second layer or both further comprise one or more penetration enhancers, which enhance the ability of dexamethasone, promethazine or both to penetrate the skin. [0031] A third type of transdermal patch is the reservoir type patch, which comprises a substrate, a reservoir, a medication-containing solution within the reservoir and an adhesive applied to the skin-facing side of the patch. In some embodiments, therefore, the invention provides a reservoir patch comprising dexamethasone and promethazine in the reservoir. In some embodiments, the reservoir further contains a skin penetration enhancer, which increases the ability of dexamethasone, promethazine or both to cross the skin. [0032] Matrix patches comprise a medication contained within a matrix, which is a semisolid in which the medication is dissolved or suspended. The adhesive is applied to the skin-facing side of the matrix. Thus, embodiments of the invention comprise a matrix patch in which a therapeutically effective amount of dexamethasone and promethazine are dissolved or suspended in the matrix. In some embodiments, the matrix also contains one or more skin penetration enhancers, which enhance the ability of dexamethasone, promethazine or both to cross the skin. [0033] Micro-needle patches are transdermal patches having micro- or nano-scale needles that pierce the cornified outer layer of the skin, thereby allowing the medication to pass from a reservoir or matrix and into the skin. Thus, embodiments of the invention comprise a microneedle patch comprising, within a reservoir or matrix, a therapeutically effective quantity of dexamethasone and promethazine. [0034] Iontophoretic patches work by applying a current to the drug, causing the drug to move out of the adhesive, matrix or reservoir and through the skin. As iontophoresis requires that the drug species be in an ionic form, one embodiment of the invention provides a transdermal patch comprising a therapeutically effective amount of pharmaceutically acceptable salts of dexamethasone and a promethazine in a matrix, adhesive or reservoir. The patch also comprises means for applying an electrical charge to the salts sufficient to force the drug combination out of the patch and through the skin. Means for applying an electrical current can include batteries, capacitors, and the like. [0035] In some embodiments, the present invention provides transdermal patches for delivery of a therapeutically effective amount of dexamethasone and promethazine. Transdermal patches have the advantage of providing controlled delivery of a dexamethasone and promethazine systemically, by delivering dexamethasone and promethazine across the skin and into the bloodstream. In some embodiments, dexamethasone and promethazine can be dissolved, dispersed or otherwise integrated into a suitable medium, such as an elastomeric matrix material. In some embodiments, penetration enhancers are used to increase the flux of the compound across the skin. The rate of such flux can be controlled by either providing a rate-controlling membrane or dispersing the compound in a polymer matrix or gel. [0036] A variety of types of transdermal patches are employed in embodiments of the invention. In some embodiments, an adhesive patch or adhesive matrix patch is prepared from a backing material and an adhesive, such as an acrylate adhesive. In such embodiments, dexamethasone and promethazine, and optionally a penetration enhancer, are formulated into an adhesive casting solution and allowed to mix thoroughly. The solution is then cast directly onto the backing material and the casting solvent is evaporated in an oven, leaving an adhesive film. A release liner is then attached to complete the system. [0037] In some embodiments, the invention provides a polyurethane matrix patch, which is employed to deliver the combination of dexamethasone and promethazine. The layers of this patch comprise a backing, a polyurethane drug/enhancer matrix, a membrane, an adhesive, and a release liner. The polyurethane matrix is prepared using a room temperature curing polyurethane prepolymer. Addition of water, alcohol, and the combination of dexamethasone and promethazine to the prepolymer results in the formation of a tacky firm elastomer that can be directly cast onto the backing material. A further embodiment of this invention uses a hydrogel matrix patch. In some embodiments, the hydrogel matrix comprises alcohol, water, a combination of dexamethasone and promethazine and hydrophilic polymers. The hydrogel matrix is then incorporated into a transdermal patch between the backing and the adhesive layer. [0038] In some embodiments, the invention provides foam matrix patches, which are similar in design and components to the liquid reservoir system, except that the gelled drug solution is constrained in a thin foam layer, typically a polyurethane. This foam layer is situated between the backing and the membrane which have been heat sealed at the periphery of the patch. [0039] In some embodiments, the invention provides a liquid reservoir patch comprising dexamethasone and promethazine. This type of patch comprises an impermeable or semi-permeable, heat-sealable backing material, a heat sealable membrane, an acrylate based pressure sensitive skin adhesive and a siliconized release liner. The backing is heat sealed to the membrane to form a reservoir, which is filled with a solution of the combination of dexamethasone and promethazine, penetration enhancer(s), gelling agent, and other excipients. [0040] In some embodiments, the invention provides a transdermal patch containing about 0.5 mg to about 100 mg of dexamethasone and about 1 mg to about 500 mg, especially about 5 mg to about 250 mg, and more particularly about 10 mg to about 100 mg, of promethazine per patch. In some embodiments, a patch adapted to release its contents into the patient over a period of about 12 hours releases about 0.5 mg to about 20 mg of dexamethasone and about 5 mg to about 100 mg, especially about 5 mg to about 50 mg, of promethazine into the patient's system per 12 hour period. In some embodiments, in which the patch is adapted to release its contents over a period of 3 to 6 hours, the patch contains about 0.5 mg to about 40 mg of dexamethasone and about 5 mg to about 100 mg of promethazine, especially about 10 mg to about 50 mg of promethazine. In some embodiments the patches according to the invention provide about 30 minutes to about 72 hours, more particularly about 1 hour to about 24 hours, of prevention or treatment of nausea and/or vomiting per patch. [0041] Transdermal Solutions, Suspensions and the Like [0042] In some embodiments, the invention provides a transdermal ointment, cream, gel, lotion or other transdermal solution or suspension. The transdermal ointment, cream, gel or lotion is made by admixing a suitable quantity of dexamethasone and promethazine with one or more excipients for the preparation of the ointment, cream, gel or lotion, in a conventional manner. In some particular embodiments, the transdermal composition further comprises at least one penetration enhancer, such as dimethyl sulfoxide, for improving the permeability of the skin and allowing passage of dexamethasone and promethazine through the skin and into the bloodstream of the patient. [0043] In some embodiments, a unit dose of the combination of dexamethasone and promethazine is in the range of about 50 μl to about 1,000 μl, especially about 100 to about 500 μl per dosage unit. In some embodiments, a unit dose of the combination of dexamethasone and promethazine contains about 0.5 mg to about 20 mg of dexamethasone and about 1 mg to about 500 mg, especially about 5 mg to about 250 mg, more particularly about 10 mg to about 100 mg of promethazine. In some embodiments, a dosage unit of a composition according to the invention contains about 0.5 mg to about 100 mg of dexamethasone and about 5 mg to about 50 mg, especially about 5 mg to about 50 mg of promethazine per unit. Thus, in some embodiments, the transdermal solution or suspension of the invention contains about 0.1% (weight/volume) to about 5% (especially about 0.5% to about 4%, and most especially about 1% to about 2%) dexamethasone and about 0.1% (weight/volume) to about 10% (weight/volume) of promethazine. In addition to conventional ointment, cream, gel and lotion ingredients, some embodiments of the invention include one or more penetration enhancers to aid in the penetration of dexamethasone, promethazine or both through the skin and into the bloodstream. [0044] The lotion, ointment, gel or cream should be thoroughly rubbed into the skin so that no excess is plainly visible, and the skin should not be washed in that region until most of the transdermal penetration has occurred preferably at least about 15 minutes and, more preferably, at least about 30 minutes. In some embodiments, each unit dose of transdermal solution, suspension or the like contains about 0.5 mg to about 20 mg of dexamethasone per dose and about 10 mg to about 100 mg of promethazine per dose and is administered about once every 3 to 24 hours, especially about once every 6 to 24 hours, and more particularly about 3 to 4 times per day. [0045] Antiemetic Kits [0046] The antiemetic compositions according to the invention are, in some embodiments, presented as part of a kit for the treatment or prevention of emesis and/or nausea. In some preferred embodiments, the kits comprise instructions for the antiemetic use of the compositions of the invention. In some embodiments, the kits comprise two or more transdermal patches comprising a therapeutically effective amount of dexamethasone and promethazine. In some particular embodiments, the kits comprise at least a first patch comprising dexamethasone and at least a second patch comprising promethazine. In some preferred embodiments, the first patch is substantially free of promethazine and/or the second patch is substantially free of dexamethasone. In such embodiments, the combination of dexamethasone in the first patch and promethazine in the second patch is a therapeutically effective amount of the combination of dexamethasone and promethazine. In such embodiments, the first and second patches constitute one dosage unit. In other embodiments, the invention provides at least a single patch comprising a therapeutically effective amount of a combination of dexamethasone and promethazine. In such embodiments, the single patch constitutes one dosage unit. Thus, a dosage unit is made up of sufficient dexamethasone and promethazine to constitute a therapeutically effective dose of the combination of dexamethasone and promethazine, whether divided between two or more patches or combined in a single patch. [0047] In some embodiments, the kit comprises more than one dosage unit. In particular embodiments, the kit comprises from 1 to about 120 or more, from 1 to about 60, from 1 to about 30, from 1 to about 10 or from 1 to about 7 dosage units. In cases where the patch(es) is (are) adapted to release a therapeutically effective amount of dexamethasone and promethazine over a 24 hour period, the kit conveniently comprises 1, about 5, about 7, about 10, about 14 or about 30 dosage units. In cases where the patch(es) is (are) adapted to provide a therapeutically effective amount of dexamethasone and promethazine over a 12 hour period, the kit conveniently comprises 1, 2, about 10, about 14, about 30 or about 60 dosage units. In cases where the patch(es) is (are) adapted to provide a therapeutically effective amount of dexamethasone and promethazine over an about 3 to about 10 hour (especially an about a 6 or 8 hour) period, the kit comprises about 1, about 4, about 40, about 60 or about 120 dosage units. The person skilled in the art will recognize that other numbers of dosage units may be included in the kit without departing materially from the present invention. [0048] Although preferred embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will be apparent to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered herein.

Relief or prophylaxis from nausea and/or emesis are provided by transdermal compositions comprising dexamethasone and promethazine. The transdermal compositions are in the form of transdermal solutions and/or suspensions, such as lotions, pastes, gels, ointments or transdermal patches.

BACKGROUND OF THE INVENTION This invention relates to an apparatus and method for cooking cereal grains and particularly to the use of a recycling step as well as use of a vertical cooker for continuously, evenly cooking a grain product while maintaining plug flow. It is well known in the cooking art to employ vertical cylindrical continuous cookers. A problem the prior art attempts to solve is even cooking of material added to cookers. Cookers of this type have a conical baffle disposed near the bottommost portion of the vertical cooker. In these prior art devices, grain is added to the top of the vertical cooker, which is circular in cross section, and removed from the bottom of the vertical cooker. The temperature of the water in a typical vertical cooker is maintained by a controller, and by use of direct steam injection or use of a steam jacket about the cooker, and the level of water in the cooker is also ordinarily controlled. In particular, it is known to use a vertical continuous cooker having a cone disposed near a bottom portion thereof. There are several teachings in the prior art of continuous process methods using vertical cookers as a part thereof. In one of these references, U.S. Pat. No. 2,638,838 issued to Talmey et al., an apparatus is shown for heating granular material in a continuous process. Talmey teaches a method of treating granular material, in a pressurized vessel, including grain, including steps of soaking, de-watering, cooking, again de-watering, dehydrating, and cooling. A float controlled valve is used to maintain constant head of water in tanks. Heated water of 200° F. is used in a mixer. Water is added along the sides of the tanks during cooking. Water separation occurs in the casing of the conveyor, not in the cooker, by way of a perforated section that is surrounded by an auxiliary jacket. The pressure cookeris vertical and has a baffle. Steam jets are supplied to the material as it gravitates downwardly in the cooker. The steam condenses and collects in the bottom of the cooker, the bottom having perforated openings so as to allow water to be drawn off by a pipe to a pump. This vessel is not, however, full of water, but rather steam which condenses and collects at the bottom. Furthermore, since direct steam injection is used, plug flow would be disrupted in this type of device. The water so collected is reinjected into the top of the cooker by a spray nozzle. However, there is no teaching or suggestion or injecting steam into the return water, nor of separating condensed water from the granular material within the vertical cooker, nor of maintaining plug flow within the vertical cooker. Furthermore, although additional treatment steps are shown, none relates to separating the final product and returning that condensate to the vertical cooker to aid cooking and ensure plug flow of the mixture of water and granular material through the vertical cooker. Such plug flow, if relatively uniform, would ensure even cooking of all grains in the cooker. Another patent, U.S. Pat. No. 3,778,521 to Fisher et al., shows a process for the continuous production of bulgur. The Fisher et al. patent shows the mixers having conical baffles therein used for the heating and mixing of wheat with water. A variety of control elements and use of steam are shown. However, steam injection appears to occur primarily in horizontal conveyor passage ways, and not in the vertical mixing devices. This differs significantly from the present invention, which doesn't use steam injection within the vertical cooker at all. Such steam injection would also disrupt plug flow if used in a vertical cooker. Moreover, the use of a separator to return liquid to a vertical cooker is not shown or suggested in Fisher nor is true plug flow taught therein. Another type of continuous process is taught in U.S. Pat. No. 3,132,948 to Smith et al., which teaches a process of producing bulgur. A multi-stage process is shown, including moistening wheat with excess water, tempering, cooking, and drying the product. U.S. Pat. No. 2,884,327, to Robbins, shows a methodof processing wheat. The wheat is subjected to heat and moisture while moving the wheat. These patents fail to teach plug flow using a vertical cooker as part of a process of cooking. Other patents, while not appearing to be as relevant as the foregoing, are also of interest. The U.S. Pats. Nos. 911,408, 1,067,342, 129,906, 3,684,526, and 3,944,678, all relate to the controlling of moisture in flour or wheat products. Each of these references relate to a vertical chamber in which a product is received and from which the product exits. The most relevant of these references is to Lowery, U.S. Pat. No. 3,684,526, showing a pipe 36 for injecting a spray mist, not disclosed to be steam, at point 39 so as to slightly moisten the flour to a moisture level of 1.9%. However, there is no suggestion in any of these patents of using water and granular material in pre-mixed form for introduction into a vertical cooker to avoid uneven cooking and to ensure plug flow. SUMMARY OF THE INVENTION It is accordingly one object of the present invention to provide a continuous process apparatus and method for uniformly cooking cereal grains, including a vertical cooker for cooking grain, a method of recirculating and reheating the cooking water, and a separator for separating the grain from cooking water, including recycling of the cooking water so separated to the mixture of grain and water entering the vertical cooker. A further object is to cook grain evenly and uniformly in plug flow in a vertical continuous cooker. Another object of the present invention is to provide a continuous process apparatus and method for cooking cereal grains including a vertical cooker receiving a pre-heated mixture of granular material and water, for continuous cooking in true plug flow to ensure even, uniform cooking; granular material such as wheat or the like being fed into the cooker by a continuous feeder, a separator including a sieve which receives recycled water combined with the water being separated and exiting from the vertical cooker, with a wheat and water mixture being separated at a sieve portion, water from the sieve being recycled to be mixed with the wheat input to the vertical cooker. It is another object of the present invention to provide an improved continuous process apparatus and method for cooking cereal grains, including a separator, a vertical cooker having a conical baffle to ensure plug flow, steam injection for heating the water, a water level controller, wheat level controller, and temperature controller for the vertical cooker, a metering pump to control the flow of grain exiting from the vertical cooker, recycling separated water from the vertical cooker by a sieve in the vertical cooker, the sieve being for separating the wheat and water. The improved continuous process apparatus and method for cooking cereal grains is used as follows. The invention is a continuous process method for cooking cereal grains. A vertical cooker is used for cooking a grain product. The cooker is filled with hot cooking water maintained at the desired cooking temperature and at a desired level within the cooker. The cooker is vertically oriented and has a conical baffle so as to ensure plug flow so that grain is neither undercooked nor overcooked. The cone angle used can be varied for different materials, as a result of routine experimentation if so desired. In the instant invention, the cooking water is maintained at a predetermined elevated temperature while drawing off a continuous stream of water through a sieve located near the lower portion of the conical baffle. The temperature of the water and wheat mixture added to the vertical cooker is maintained by a temperature controller, and the level fo water in the cooker is maintained by a level controller. A vibratory mechanism is used to ensure smooth plug flow of grain from the cooker, by vibrating the sieve and baffle members. Cooked grain exits from the bottom of the cooker under the action of a metering pump. The mixture of grain and water flows to a separator outside the vertical cooker. Grain is separated from the water by the separator, with water from the separator selectively returning to the cooker for recycling as needed. Water is recycled from the cooker to be mixed with the grain entering the vertical cooker, thereby causing convection heat transfer from the water to the grain due to the higher velocity of water relative to the grain, which is retained and metered in flow by the metering pump. This ensures plug flow in the cooker since no liquid injection disturbs flow in the cookers; also, since no steam jacket is used, an even, generally uniform, heating of the grain is possible since the hot water is pre-mixed with the grain before entering the cooker, and the conical barrier and the sieve permit controlled plug flow through the vertical cooker to ensure even cooking. Further details and advantages of the present invention appear from the following description of a preferred embodiment shown schematically in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a process according to the present invention; FIG. 2 is an elevational view of the vertical cooker partly broken away toshow the conical baffle and sieve members of the vertical cooker; FIG. 3 is a sectional view taken long line 3--3 of FIG. 2, showing struts connecting the sieve member to the conical baffle, with areas of the sieve member being visible about the baffle portion shown. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a schematic diagram of the continuous process of the present invention. A raw grain supply bin 62 supplies raw grain to supply 60 which supplies grain at a temperature range of approximately 50° F. to 110° F., or any ambient temperature, by a raw wheat supply conduit 2 to a wheat use bin 401. The raw wheat supply coming from storage can of course be at an ambient temperature lower or higher than the usual range given, depending on local conditions and storage methods. The wheat use bin 401 supplis grain to a continuous feeder 63, which supplies grain on a weighed basis as indicated at 114 to a mixer 101. The mixer 101 receives a steady stream of recirculating water from conduit 115, and also can receive make-up water from a fresh water supply 50 by a conduit 113. The mixer assures wetting and moistening of the individual grains of the granular material received from the continuous feeder, by the recirculating water and by the fresh make-up water. Any conventional mixing device can be used, for example, a tank having a motorized stirrer; any commercial mixer; a ribbon blender; a screw conveyor; continuous paddle mixer; or the like. The grain and water mixture, referred to hereinafter as a slurry, exits the mixer by a conduit 116 at approximately 200° F., depending upon the initial temperature of the water and wheat entering the mixer 101. The conduit 116 supplies the slurry to a heater 250. The heater 250 can be any type of heater, for example, a steam injection heater, a coiled-tube heater having a segregated heating fluid within the coils, any convection heater having a heating means associated therewith, or any other heater suitable for heating the slurry. The slurry is heated, in a preferred embodiment, to 210° F. by steam injuection. Any other heating means may obviously be used instead of steam injection. In the preferred embodiment, steam is supplied from a steam supply 70 at any pressure, from any source, in this case for example, at approximately 25 psig through a conduit 117 to the steam injection heater 250. There, the slurry and steam are mixed to heat the slurry to approximately 210° F. A steam injection control valve 42 controls the amount of steam injected to the heater 250, preferably by a temperature sensor communication line 33 which senses slurry temperature in the conduit 118. A temperature controller 22 receives the temperature information from the temperature sensor communication line 33, and the temperature controller 22 sends a control signal, by a steam valve controller communication line 32, to the steam control valve 42. This permits maintaining of any predetermined slurry temperature, in this case of approximately 210° F. Of course, any temperature appropriate to the particulate material (and process) could be maintained where particulate material other than grain is being cooked or otherwise processed. The conduit 118 carries the heated slurry from the heater 250 to the top 46 of the vertical cooker 20. The slurry falls to a grain level 701 below the water level surface 702, the grain level being controllable as desired. The liquid water level 702 is preferably maintained at a predetermined elevation above that of the grain level 701, although for other processes the liquid level can be maintained below the particulate level if such is desirable. This permits even distribution of the grain across the top of the cooker 20 to ensure plug flow. Plug flow is defined as the first grain in to the top of the cooker 20 is the first grain out, which ensures even cooking of all individual grains. This permits careful control of cooking time since overcooking of some grains is not required to ensure that all grains are properly cooked. Also, due to the controllable mass flow rate of recirculating water, discussed further hereunder, together with the separation and removal of the water by a sieve member 35 at the bottom of the cooker 20, the recirculating water can be controlled to flow with a relative downward speed or relative upward speed to the individual particulate grains. This would tend to increase the rate of heat transfer to individual grains by the water, since heat transfer is higher from a fluid to a solid when there is a relative velocity between them. This would tend to reduce the cooking time required, and would not disturb plug flow, as discussed further hereunder. A fill pipe 300 enters the top 46 of the cooker 20, and can be used to initially fill the system with water. The system can be cold-started in this manner without grain, so as to preheat the water to desired levels. A vent line 400 is provided at the top 46 of the cooker 20, to allow escape of vapor, air, or water if pressure builds up in the cooker 20. The cooker 20 in a preferred embodiment can operate at atmospheric pressure; however, the cooker 20 can be adapted, if desired, to be a pressure cooker, and the associated equipment would then be adapted for pressure operation also. For example, pressure could be built up by choice of an appropriate mixer 101 to pressurize the slurry in the line 116. A pressure relief valve could then be used atop the cooker 20 instead of the vent line 400, to permit a predetermined pressure level to be maintained in the cooker 20. The metering pump 145, together with valve 41, could be used to maintain system pressure. Then, the remaining components may optionally be adapted for high pressure use if desired, although from the preceding discussion it is readily apparent that no other additional pressurized equipment would be necessary. Atmospheric operation is an advantage over pressure cookers, since less structural cooker 20 material thickness and conduit thickness would be required for atmospheric operation. The vent line 400 for atmospheric operation can be an open conduit pipe, or any other type of vent means. The fill conduit 300 for atmospheric operation can be any conventional pipe or conduit means. A water level sensor 109 is attached to the cooker 20 in the vicinity of the desired water level 702. A wheat level sensor 110 is attached to the cooker 20 in the vicinity of the desired wheat level 701. These sensors can be optically actuated with electronic light detecting means to determine the presence of water or wheat, or they may be mechanical pivoting arm float devices; or may be any other known level sensing devices such as acoustic sensors which can send an output signal to a level controller, known in the art. Such level control is not crucial to the present invention, however, and may be done manually if desired using human operators watching a sight glass, for example, and operating appropriate control valves or motor controllers. The use of controllers in the present invention is described more fully hereunder. The vertical cooker 20 is shown in greater detail in FIG. 2. The cooker 20 has an upper cone baffle 502 connected to a lower cone baffle 501. The upper cone baffle 502 prevents "funneling" of grain through the central portion of the cooker 20, which funneling would prevent plug flow. A particular cone angle is successful for this purpose, which in the preferred embodiment is 45 degrees as measured at the cone apex. The cone angle, however, may be any appropriate angle that results in generally plug flow of the specific particulate material used. The optimum cone angle, for plug flow, is believed to depend upon the specific particulate material properties involved, such as grain size, adhesion properties, the fluid property behavior of the fluid used (in the present preferred embodiment, water), and so on. Thus, the optimum cone angle can be determined experimentally if necessary for a particular particulate material chosen and for particular operating conditions. Furthermore, although a cone is used in the preferred embodiment, other shapes can be used based, for example, upon complex curved shapes (such as a parabolic, hyperbolic, or dish shapes) determinable mathematically for a given set of particulate material and fluid parameters. The only criterion required is that the resulting baffle (here, cone 502) cause generally plug flow of grain through the vertical cooker. The lower baffle 501 prevents eddy current flow in what would otherwise be a "dead zone" which would otherwise exist beneath the upper baffle 502. This therefore further ensures plug flow, since no grains can be swirled, mixed, or trapped by eddy current flow in such a "dead zone". A flexible expansion joint 500 connects the vertical cooker 20 to the bottom 36, as seen in FIGS. 1 and 2. In FIG. 2, showing the cooker 20 and the bottom portion 36 cut away to reveal the interior details of the cooker, the sieve member 35 is seen as running parallel to the bottom 36. A valve 37 is preferably provided to control or shut off flow through conduit 8. The sieve member 35 is formed of a sieve material structure to permit passage of water therethrough but not of the entrained grain such as wheat. A sieve material structure could include, for example, a plate having holes therein, the holes being sufficiently small to prevent passage of individual particles of the particulate material. In the preferred embodiment, the holes would be smaller than the wheat grains. Other materials usable include a mesh screen, a corrugated sheet having slots therein, or any other material which can serve to permit passage of fluid but not individual particles of the particulate material (here, in the preferred embodiment, wheat grains are the particulate material). It is noted from FIGS. 1 and 2 that, while the sieve member is generaly conically shaped so as to be more or less generally parallel to the lower cone portion 501, any shape generally having a uniform spacing (or a gradually tapering spacing) from the member 501 can be used, since this tends to maintain plug flow. This is so since portion 501 is not limited to a cone shape, but can have other shapes as well, including complex curved or angled surfaces, so long as plug flow is substantially maintained. Such modifications are contemplated as being within the scope of the present invention. As seen in FIG. 2, a solid member 707 acts as a connector for members 36 and 35, and prevents leakage of water downward. This therefore prevents re-mixing of water (previously separated from the particulate material by the sieve 35) with the material flowing into conduit 8. The member 707 would appear generally disc-shaped if seen from the bottom of FIG. 2. A vibratory unbalanced motor 605, being connected by at least one strut 606 to the bottom portion 36 preferably continuously vibrates the bottom portion 36, including the bottom 36 and sieve 35, to facilitate the flow of grain across the sieve 35 without disrupting plug flow as would occur if no vibratory effects were present. The vibratory action is not transmitted directly to, or absorbed by, the vertical cooker 20, due to the presence of an expansion joint 500, which is resiliently flexible, disposed circumferentially about the vertical cooker 20 where it joins the bottom 36 and sieve 35. Struts 503 connect the upper baffle member 502 and lower baffle member 501 in spaced relationship to the sieve 35. The vibratory motion imparted to the lower portion, including the conical baffle members 501 and 502, is indicated as being generally horizontal by the arrows 504 in FIG. 2. However, such vibratory motion is not necessary to the present invention, and substantially plug flow (once started) would exist without in the cooker even in the absence of such vibratory motion. Thus, as can be seen from the figures, plug flow is maintained by the presence of the preferred conical baffle members 501 and 502, together with the sieve member 35 and the vibratory action of the motor 605 connected to the bottom portion 36. Wheat exits from the bottom-most portion of the bottom member 36. At the very bottom of the bottom member 36 in FIG. 2, a solid barrier 707 exists connecting the bottom-most edges of the bottom member 36 to the bottom-most edges of the sieve 35 to prevent flow of water downward with the flow of the remaining wheat-water mixture. Referring back to FIG. 1, the flow of the wheat-water mixture, flowing from the bottom 36 of the cooker 20, flows through a conduit 8 and a valve 37, and then to a metering pump 145 controlled by variable speed motor 45. This determines the speed with which the wheat migrates through the cooker 20 in plug flow. A level controller 105 controls the wheat level 701. The wheat level controller 105 senses the wheat level by a wheat level sensor communication line 106 connected to the wheat level sensor 110. The wheat level controller 105 sends a control signal along line 107 to the metering pump drive motor 45. This controls wheat residence time in the vertical cooker 20. Excess water removed by the sieve member 35 is recirculated through the system, the recirculated water being drawn off from the region between the sieve member 35 and the bottom member 36 by a conduit 119. A control valve 41 controls the flow of the recirculating water in the conduit 119, and is controlled by a level controller 21. The level controller 21 controls the water level 702, which level is sensed by the water level sensor 109. A water level sensor communication line 31 communicates the water level to the level controller 21; the level controller 21 then controls the position of the valve 41 by means of a water level controller communication line 34. A conduit 121 conveys the recirculating water to a separator 200. Due to the presence in the preferred embodiment of recirculating water in a flow volume and mass flow rate greater than that of the wheat, in turn due to the presence of the sieve member 35, water flows downward verticaly through the cooker 20 at a speed different from, and usually greater than, that of the grain. This results in greater convection heat transfer into the grain of heat from the water, so as to cook the grain completely to the interior of each grain particle. The grain and water mixture is associated in approximately equal portions and flow through the conduit 8 to the metering pump 145. From there, the metered mixture is carried by conduit 10 to a separator 80. The separator 80 is driven by a motive means 144, which may be pneumatic air or electrical power or rotary mechanical power, for example. Any conventional separator can be used, such as a centrifugal separator, vertical rotary separator, or the like. In the preferred embodiment, a vertical rotary-type separator is used to separate the water from the grain. During the cooking process, the grain absorbs water, and therefore a continuous heavier weight of cooked grain is produced than the continuous original entering weight of the raw uncooked grain entering the system. The cooked grain leaves the separator at outlet 4 and is conveyed or moved to be further processed as indicated at 85. The water separated from the cooked wheat exits the separator 80 along conduit 120, where conduit 120 joins with conduit 121 into an inlet conduit 122 to a fine solids separator 200. The separator 200 has a fine solids exit 201 and a water outlet 202, where the water has been sufficiently separated from wheat particles so as to be suitable for recycling in the system. A standpipe 9, having an oversized conduit portion 301 to receive the water from outlet 202, is provided. The water from the standpipe 9 communicates along conduit 306 with the inlet of a pump 43. Overflow and excess water from the oversized conduit portion 301 passes in the preferred embodiment to a drain or sewage conduit 112 along overflow conduit 303 which permits overflow water to fall into an oversized conduit 302, which oversized conduit 302 communicates with the drain or sewage 112. This also prevents overflowing of the conduit portion 301, since overflow water will be drained off over conduit 303. The fine solids collected from the separator 200 exit through conduit 201 and fall as indicated at 307 either alone or within a conduit, to a sludge receptacle as indicated at 111 as a car for hauling sludge which operates on wheels. These fine solids can be disposed of either as animal feed or as waste material which is unusable, or can be used in any other manner desired. The recirculating pump has a conduit 115 having a control valve 305 therein. The control valve 305 is controlled by a manual or automatic controller 304. This allows manual or automatic setting of the amount of recirculating water used in the system. The conduit 115 then enters mixer 101, previously described. This completes the recirculating portion of the cycle. As noted, the water level 702 in the preferred embodiment is maintained by a level controller 21 which controls valve 41 by way of the valve control communication line 34. The water level sensor communication line 31 communicates with the level controller to transmit the level sensed by level sensor 109. The control valves may be any type of control valve, including electrically operated, electro-mechanical, electronic, pneumatically-actuated, or the like. Also, the level sensing devices may be acoustic, gamma ray, electro-mechanical, optical, or may include any other type of level sensing device. An example of the operation of the system for a particular level of supply of grian is given hereunder. Wheat is supplied from the wheat use bin 62 to the feeder, preferably a feeder 63 which in the present example feeds the grain on a continuous basis evenly into the mixer 101 at a nominal approximate rate of 4,336 lb/hr. The initial wheat conditions in this example are 13% moisture content at 50° F. Therefore, approximately 9 GPM of water enters with the wheat. The wheat path into the mixer 101 is indicated by conduit 114. Recirculating water in the present exampel enters the mixer 101 along conduit 115, at a rate of 169 GPM at a temperature of approximately 205° F. Also, new supply water is added from the water supply 50 through conduit 113 into the mixer 101 at a rate of 9 GPM in the present example at a temperature of 114° F., which has been preheated to the stated temperature. It will be understood that none of the temperatures, pressures, and flow rates stated in the present example limit the possible temperature ranges, pressures, and flow rates in any way. The present example illustrates merely one set of operating conditions possible with the present invention. Any temperatures, pressure, or flow rates can be used as appropriate to the process being used in the present apparatus. The mixer 101 mixes the grains without crushing them, together with the recirculating water and new supply water. The mixture then flows through conduit 116 to the heater 250; at this point, a flow rate of 185 GPM water, at a temperature of 200° F., passes through the conduit 116. The heater 250 receives the flow in conduit 116 as well as steam at a pressure of 25 PSIG and at a rate of 1,240 lb/hr from the steam supply 70. Any steam pressure or flow rate can be used; the present valves indicated are for illustration only of operation in one example of the use of the present invention. The steam travels through conduit 117, and the flow rate is controlled by a controller valve 42 which is controlled by the temperature controller 22. The heated slurry exits from the heater along conduit 118, at a rate of 187 GPM, at a temperature of 210° F. of water, which has been heated by the steam supplied to the heater. The heated slurry enters the top of the cooker 46, with the grain settling to the grain level 701 and the water settling to the water level 702. This results in even distribution of the grain across the level 701. The grain descends in plug flow controlled by the metering pump 145. The upper conical baffle 502, together with the lower conical baffle 501, ensures plug flow. Water flows through the sieve member 35 and is drawn off along conduit 119 at a rate of 161 GPM at a temperature of 209° F. and having 1.5% solids. The wheat mixture exits through conduit 8 at a rate of 7,000 lb/hr of wheat and including water at a rate of 26 GPM. It will be understood that none of the temperatures, pressures, and flow rates stated in the present example limit the possible temperature ranges, pressures, and flow rates in any way. The present example illustrates merely one set of operating conditions possible with the present invention. Any temperature, pressure or flow rates can be used as appropriate to the process being used in the present apparatus. This flow enters conduit 10 where a separator 80 separates the wheat from the water, the wheat going into conduit 4 at a rate of 7,000 lb/hr of wheat having 47% moisture content, at a temperature of 200° F. The water separated from the wheat exits the separator 80 along conduit 120 at a rate of 14 GPM, having a temperature of 200° F. and a solids content of 1.5%. These flows combine in conduit 122 for a combined flow rate of water of 175 GPM entering the separator 200, where the fine solids are to be removed. The separator 200 removes approximately 300 lb/hr of sludge, at 205° F., moisture content of 92.5%, through outlet 201. This sludge enters the sludge cart 111 for disposal. The separated water flows through conduit 202 at a rate of 175 GPM at a temperature of 205° F. into the conduit 9. The conduit 303 carries approximately 6 GPM to the drain 302. This water then flows to a sewage conduit 112 (or to further wastewater processing). The recirculating water pump 43, then returns the water to the mixture 101 along conduit 115 at a water flow rate of 169 GPM. FIG. 3 is a view taken along line 3--3 of FIG. 2 showing the general arrangement of the parts in a top view which is partially in section. Here, the circular outline of the lower baffle member 501 is shown connected to the screen 35 by a plurality of struts 503. The textured nature of the screen 35 is generally indicated in FIG. 3 where the circular sectional portion in hatching of the screen 35 is shown with the remaining portion of the screen 35 visible. Also, the circular cross sectional outline of the bottom 36 is shown in FIG. 3 as well. Recycling the cooking water, heating, and mixing it externally results in a very even internal cooker temperature as well as even and flow distribution in the cooker and greater uniformity. If this mixing and heating were done in the cooker 20, flow disruption of the plug flow of wheat would occur, as would temperature non-uniformities in the grain occur. Such plug flow disruption would be undesirable and would result in overcooking of some particles, and undercooking of other particles of grain. Therefore, the recycling and mixing steps taking place outside of the cooker 20 provide an important improvement over the prior art. Conventional steam heating, i.e. the providing of heat by heating of the outer jacket of the cooker 20, would result in an uneven heat distribution of grain within the cooker 20, also resulting in uneven cooking. Also, the present cooker has no internal moving parts, and therefore is more reliable while at the sme time maintaining even cooking conditions and plug flow conditions of grain flow, which is critical to the success of this invention. Each grain particle receives uniform treatment with regard to heating as well as cooking water penetration. There is less mechanical maintenance required than in the prior art devices, and is a sanitary design allowing for clean-in-place cleaning. The step of removing water at the sieve 35 for recyling is essential, because the grain must be raised from a temperature of approximately 50° F. (or ambient temperature) to approximately 210° F. The grain must be held within the cooker 20 for a sufficient time to cook it fully. This time period will vary depending upon the type of grain used, and water temperature, such cooking times being generally known in the prior art. Because external heating is used, heat is continuously added to the recycling water and grain mixture, and therefore the water is the only medium used because even heating results therefrom. Steam injection directly into the cooker would destroy the uniform plug flow of grain through the cooker. As another example of the use of the present invention apparatus and process, a hypothetical set of values of water flow velocity and wheat flow velocity is calculated hereunder. This demonstrates how convection heat transfer can be controlled or increased in the vertical cooker 20 by control of the relative recirculating water flow rate to the wheat-and-water mixture flow rate in conduit 8. Assuring the flow rates in the preceding example, for an inner diameter of three feet of the vertical cooker 20, the water velocity an be calculated from the equation Q=VA, where Q=volume flow rate (which is calculated as mass flow rate divided by the material density); V=velocity (the variable to be determined); and A=effective cross-sectional area through which the material flows. It is assumed that the absolute density of water in the cooker is 62.27 lb/cubic foot; the absolute density of raw wheat is 81.0 lb/cubic foot; and the absolute density of cooked wheat is 75.9 lb/cubic foot. At the top of the cooker 20, between levels 701 and 702, the minimum water velocity is found by assuming that there is no falling raw grain (if there were, the effective area for the water flow would be reduced and the water velocity, by the equation, would be increased.) For the water flow rate of 187 GPM; and a cross-sectional area of 7.07 square feet; the minimum water velocity between level 702 and 701 is at least 213 ft./hr. A water and raw grain flows just below level 701, assuming for this example each effective area A (through which each material flows) is one-half the total available area, the velocities are as follows. The water velocity just below level 701 would be approximately 426 ft./hr.; the raw wheat velocity just below level 701 would be 23 ft./hr. Therefore, the velocity difference for heat transfer purposes is 403 ft./hr. in this hypothetical example. Similarly, for the relative velocities of water and cooked wheat just above the top of cone 502 (in this hypothetical example) would be as follows, again assuming the effective area for flow is one-half the total cross-sectional area. The cooked wheat velocity (which cooked wheat has an increased moisture content over raw wheat) would be 43.4 ft./hr.; the minimum water velocity (disregarding increased velocity due to transverse flow about individual particles) would remain at approximately 426 ft./hr. The velocity difference for convection heat transfer is then approximately 383 ft./hr. Other, more extreme examples could easily be calculated. For example, for a very dense particulate material, and for much greater recirculating fluid flow rates, greater convection heat transfer rates could be obtained if such is desired. Also, for the case of chemical reaction between the fluid and the particulate material, relative velocity would affect the reaction rate. The improved continuous process apparatus and method for cooking cereal grains of the present invention is capable of achieving the above-enumerated objects and while preferred embodiments of the present invention have been disclosed, it will be understood that is is not limited thereto but may be otherwise embodied within the scope of the following claims.

A vertical cooker vessel is used for cooking a grain product. The cooker is vertically oriented and has a conical baffle so as to ensure plug flow so that grain is neither undercooked nor overcooked. The cooking water fills the vessel and is maintained at a predetermined elevated temperature while a continuous stream of water is drawn off through a sieve in the bottom portion of the cooker, then recirculating the water, mixing with raw grain, and then heating, where steam is added to reheat the water and grain. The mixture is added to the top of the vessel. Cooked grain exits from the bottom of the cooker under control of a metering pump. Grain is separated from the water, with water from the separator returning to a mixer for mixing with the recycled water. A conical baffle is located near the sieve. This ensures plug flow of grain through the cooker. A lower second conical baffle prevents turbulent flow beneath the first conical baffle, which flow would otherwise disrupt plug flow.

BACKGROUND OF THE INVENTION 1) Field of the Invention The present invention relates to brassieres. The invention relates more particularly to brassieres including non-underwire and underwire brassieres, and blanks and methods for making such brassieres, wherein the blanks are formed from circularly knit fabric tubes. 2) Description of the Related Art Brassieres are generally designed to provide support, shaping, and separation of the wearer's breasts. Conventionally, brassieres for larger-breasted women often include underwires extending along the lower margins of the breast cups. Underwires provide a level of stability, or at least the perception of stability, that fabric alone generally cannot provide, in part because fabric cannot support compressive forces the way underwires can. Typically, brassieres are fashioned in a cut-and-sew manner, as exemplified for instance in U.S. Pat. No. 4,372,312. A brassiere made in this manner may consist of more than a dozen separate fabric pieces sewn together. One advantage of the cut-and-sew method is that different areas of the brassiere can be given different properties, since the various fabric pieces can be of different knits, different yarns, etc. It may be advantageous, for example, to make some portions of the brassiere resiliently stretchable to hug the wearer's body, while other portions are relatively unstretchable for greater stability. The cut-and-sew method, however, is disadvantageous in that it entails a great number of cutting and sewing operations. Accordingly, methods of fashioning brassieres from circularly knit fabrics have been developed in an effort to improve the speed and efficiency of production. For example, commonly assigned U.S. Pat. Nos. 5,479,791 and 5,592,826 disclose methods for making non-underwire brassieres from circularly knit tubular blanks. The brassieres are made from single-ply tubular blanks that have a turned welt at one end to form a torso portion of the brassiere. A series of courses for defining breast cups and front and rear shoulder straps are integrally knit to the turned welt. The brassiere requires sewing only for joining the front and rear shoulder straps to each other. The '826 patent discloses modifying the knit structure along outer edges of the breast cups nearest the wearer's arms to form panels having a greater resistance to coursewise stretching than the remainder of the fabric blank. The relatively unstretchable panels provide increased lift and support. U.S. Pat. No. 6,287,168 overcomes some of the aforementioned problems by providing a brassiere formed from a circularly knit fabric tube 50 , as shown in FIGS. 2 and 3 of the '168 patent. The blank is knit to have two pairs of breast cups 24 , torso encircling portions 26 and central panels 28 that are arranged in mirror image about a fold region 56 along which the blank is folded so that the cups, torso encircling portions and central panels overlap and form a two-ply structure. Advantageously, the central panel can be knit to have greater resistance to stretching than the cups and torso encircling portions for an effect similar to cut-and-sew brassieres but without seams for additional wearer comfort. Despite the minimal seams, however, the brassiere still requires the use of elastic banding 46 to secure the edges of the overlapping material together, as shown in FIG. 1 of the '168 patent. Elastic banding has the aesthetic drawback in that it can sometimes show through a blouse. In addition, elastic banding, depending upon its location, can reduce wearer comfort. Therefore, it would be advantageous to have a brassiere that provides adequate and comfortable support for the wearer while at the same time reducing the use of elastic banding and seams. It would be further advantageous if the brassiere were constructed of a circular knit fabric tube to minimize the amount of cutting and stitching necessary to construct the brassiere. BRIEF SUMMARY OF THE INVENTION The present invention addresses the above needs and achieves other advantages by providing a brassiere for extending around a wearer's torso and supporting the wearer's breasts. The brassiere includes a torso strap supporting a pair of breast cups which in turn support the wearer's breasts. The breast cups are constructed of a two-ply fabric, preferably a circularly knit fabric, and each of the breast cups has a fold line positioned along at least a portion of its upper edge so as to improve wearer comfort and eliminate the need for elastic trim along the upper edge and thereby reduce seams visible through clothing. Optionally, the fold may be knit to have a thinner material than the remaining plies to facilitate formation of a crisp fold along the upper edge of the breast cup, which helps the fold lie flat against the wearer's skin and thereby imparts a smooth, finished appearance. Also, an underwire may be attached along a lower edge of each of the breast cups to provide extra support. In one embodiment, the brassiere of the present invention includes a torso strap and a pair of breast cups. The torso strap has at least one pair of ends. A two-ply fabric material having an inner, body-adjacent layer and an outer layer defines the pair of breast cups. The breast cups are attached adjacently to each other and extend between the ends of the torso strap. Each of the breast cups has a lower edge that when worn extends under a respective one of the wearer's breasts. The lower edge includes a seam extending at least partly therealong. An upper edge of each of the breast cups is configured to extend over at least an upper portion of the respective one of the wearer's breasts. The upper edge is defined by a fold line between the inner and outer layers so as to provide a comfortable fit for the wearer. In another aspect, the upper edge is configured to extend along a medial portion of the wearer's breast. More particularly, the breast cups are attached at a point between the wearer's breasts and each folded upper edge extends laterally upwards from the attachment point along the medial portions of the wearer's breasts. The torso strap may also be constructed of a two-ply material and includes at least one edge defined by a fold line between its plies. Preferably, the fold line defines a lower edge of the torso strap. The torso strap may be separated into a pair of lateral panels each having a free end opposite the torso strap's attachment to one of the breast cups. Cooperative fastener members attached to the free ends of the two panels allow the free ends to be releaseably joined so that the torso strap can be secured about the wearer's body. The two-ply fabric material defining the breast cups may be formed of a circularly knit fabric blank folded upon itself along the fold line defining the upper edge of each of the breast cups. The free edges of the breast cups may have underwires either disposed against an exterior side of one of the plies, or between the plies to provide extra support for the wearer's breasts. In yet another embodiment, the present invention includes a blank for making a brassiere. The blank includes a first series of courses defining a first pair of breast cup panels and a first torso strap panel. The first series of courses begins at a first end of the fabric structure and progresses toward an opposite, second end of the fabric structure. An end of the first series of courses defines an upper edge of the breast cup panels and a lower edge of the torso strap panel. A second series of courses is knit to the end of the first series of courses, progressing to the second end of the fabric structure. The second series of courses defines a second pair of breast cup panels and a second torso strap panel arranged in mirror image to the corresponding panels of the first series of courses. In this manner, the fabric structure can be folded about a fold line located between the first and second series of courses to create a two-ply structure having the first breast cup panels and the first torso strap panel overlying the second breast cup panels and the second torso strap panel, respectively. Preferably, the fabric structure is a circularly knit fabric tube, which may have a turned welt at one or each end of the tube. Also, the fold line may have a thinner knit than the rest of the blank so as to facilitate sharp folding so that these edges of a finished brassiere that are formed by the fold will lie flat against the wearer's skin. The present invention has many advantages. For instance, the smooth upper medial edge on each of the breast cups and the smooth bottom edge of the torso strap minimizes the amount of stitching and or banding needed to form the brassiere. Banding and seams tend to show through clothing, creating unsightly lines, especially when in contact with the clothing, such as on the top edge of a breast cup immediately beneath a blouse or shirt. Avoiding the use of seams and/or banding on the upper edge of the breast cup where a blouse or top generally makes close contact therefore improves the aesthetic appearance of the wearer. In addition, reduction of banding and stitching tends to reduce the effort and cost of constructing the brassiere. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: FIG. 1 is a perspective view of a two-ply brassiere of one embodiment of the present invention being worn by a wearer; FIG. 2 is a plan view of the brassiere of FIG. 1 laid flat; FIGS. 3-5 are sectional views of the brassiere of FIG. 1 along the section lines shown in FIG. 2; FIG. 6 is a perspective view of a tubular blank defining panels of the brassiere of another embodiment of the present invention; and FIG. 7 is a plan view of the tubular blank of FIG. 6 cut longitudinally and laid flat. DETAILED DESCRIPTION OF THE INVENTION The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. A brassiere 10 of one embodiment of the present invention is shown in FIGS. 1 and 2. The brassiere includes a pair of breast cups 14 , a torso strap 16 attached to the breast cups and a pair of shoulder straps 20 attached to the breast cups and the torso strap. The brassiere 10 also includes an underwire 24 sewn to each breast cup for further stability, as shown in FIGS. 2, 3 and 5 . Each underwire 24 is encased in a fabric casing 26 and the casing is sewn or otherwise attached to the respective breast cup. The breast cups 14 and torso strap 16 preferably have a knit structure that makes them resiliently stretchable vertically and horizontally. The breast cups 14 and torso strap 16 can be knit, for example, from various types of face yarns depending on the desired properties of the fabric, and the face yarns can be of various deniers. The selection of the face yarns and the knit depend primarily on the desired characteristics of the fabric such as the hand, appearance, texture, etc. The breast cups 14 and torso strap 16 can also incorporate elastomeric yarns such as spandex (bare and/or covered) or the like so as to impart resiliency to the fabric. If desired, portions of the breast cups 14 and torso strap 16 may be knit to achieve greater resistance to stretching, as described in commonly assigned U.S. Pat. No. 6,287,168 which is incorporated herein by reference. For instance, some parts of the breast cups 14 and torso strap 16 may be knit from different yarns or can have a different configuration of stitch loops than the other parts. The torso strap 16 in the illustrated embodiment is formed in two halves comprising one lateral panel having one end attached to one of the breast cups 14 and another lateral panel having one end attached to the other breast cup. The free end of one of the halves of the torso strap has fastener members 28 , such as hooks, attached to it. The free end of the other half of the torso strap has cooperative fastener members 30 , such as eyes, attached to it for engagement with the opposite fastener members 28 so that the brassiere can be engaged about the torso of a wearer. The brassiere 10 preferably has a two-ply construction as best seen in the cross-sectional views of FIGS. 3 through 5. Each of the breast cups 14 and the torso strap 16 are formed from a piece of fabric, preferably cut from a single, continuous piece of circular-knit fabric, folded upon itself to define an inner ply 32 that faces the wearer's body and an outer ply 34 that faces outward. Advantageously, the plies of the breast cups are folded so as to strategically place their edges formed by folding for maximum comfort and to minimize the appearance of seams through outer clothing. For instance, as can be seen in the illustrated embodiment, a fold line of the plies of each of the breast cups 14 is positioned so as to form a bandless upper, medial edge 38 . A fold line of the torso encircling strap 16 is on the bottom of the torso encircling strap so as to form a bandless bottom edge 50 . The orientation and size of the smooth upper edge of the breast cups 14 can be changed to suit the style or type of the brassiere and still be within the scope of the present invention. For instance, a lateral portion of the upper edge may be smooth and seamless. The lower, free ends of the plies of each of the breast cups 14 are folded over (forming a four-ply region for a smooth edge) and stitched together with the same stitching used to secure the fabric casing 26 enclosing the underwire 24 to the breast cups, as shown by the sectional view in FIG. 3 . In non-underwire brassieres, the free edges of the breast cups can be secured by stitching, ultrasonically welding, gluing, or otherwise attaching a strip of elastic or non-elastic banding that is wrapped over the free edges of the breast cups for a finished edge. Also, the underwire can be attached in other configurations, such as by being sealed or stitched between the plies of the breast cups 14 , or housed in the fabric casing 26 stitched onto the front of the breast cups. Medial portions of the free ends of the plies forming the torso encircling strap 16 adjacent the breast cups 14 are also secured to the breast cups by stitching or otherwise attaching the fabric casing 26 and underwire 24 to the breast cups. In particular, the medial portions of the free ends of the torso strap 16 plies are secured between the plies of the breast cups 14 and the casing 26 , as shown by the sectional view in FIG. 5 . The remainder of the free ends of the plies along the upper edge of the torso strap 16 and the lateral edges of the breast cups 14 are secured together by extending the portions of the shoulder straps 20 thereover. The shoulder straps are preferably formed of a strip of banding 36 folded over on itself and joined together. The banding is also wrapped about the free edges of the plies of the breast cups 14 and torso strap 16 and secured thereto, as shown by the sectional view of FIG. 4 . The brassiere 10 preferably is fabricated from a circularly knit fabric tube 40 , as shown in FIG. 6 . The tube 40 preferably has a turned welt 42 formed at one end and may have another turned welt (not shown) at the other end to prevent the tube from raveling and to facilitate handling of the fabric in subsequent fabrication processes as described below. Knitting of the tube 40 begins by knitting the turned welt 42 . A first series of courses is then knit to the turned welt 42 so as to form a first tubular structure 40 a defining panels 14 for forming the breast cups and the torso strap 16 . The first series of courses terminates at a fold region 46 that will define the lowermost edge of the finished brassiere. Preferably, the fold region 46 is knit to be thinner than the rest of the fabric tube, which can be accomplished, for example, by dropping the heavier yarns for a few courses (e.g., for about 8 courses) such that only the lighter yarns are knit for those courses. Next, a second series of courses is knit to the end of the first series of courses so as to form a second tubular structure 40 b forming an extension of the first tubular structure 40 a . The second tubular structure 40 b defines breast cup panels 14 and torso strap panel 16 in mirror image to the corresponding features of the first tubular structure about the fold region 46 . At the end of the second series of courses, an optional turned welt can be knit and the fabric tube 40 is taken off the circular knitting machine. By folding the fabric tube 40 about the fold region 46 , the second tubular structure 40 b can be positioned in overlying relation to the first tubular structure 40 a so that the breast cup panels and torso strap panels of the two tubular structures are overlying and in registration with each other. If it is desired to fabricate a brassiere having a single continuous torso strap 16 (i.e., such that the wearer dons the brassiere by slipping it over the head and onto the torso), the folded fabric tube 40 can then be cut along sew lines defining the outlines of the breast cup panels 14 and the torso strap panels. In particular, a pair of the overlapping breast cup panels 14 are separated from the other pair of the overlapping breast cup panels and the overlapping torso panels 16 prior to folding and stitching. The panels are then stitched together into the above-described finished arrangement by rotating the breast cup panels 14 until the fold lines 38 are oriented as the upward medial edges of the breast cups, as shown in FIGS. 1 and 2. The medial portions of the free edges of the plies forming the torso encircling strap 16 are secured to the adjacent portions of free edges of the breast cups 14 by attachment of the underwire 24 and its fabric casing 26 , as shown in FIGS. 3 and 5. Attachment of the fabric casing also attaches the breast cups 14 together. The shoulder straps 20 are attached to the remaining free edges of the breast cup panels 14 and the torso panels 16 . It should be noted that these steps may be performed in different orders, such as cutting and then folding each of the panels. Alternatively, the fabric tube 40 can be slit along a longitudinal line 48 located generally diametrically opposite from the breast cup panels 14 , as shown in FIG. 6, and the slit tube can be opened up into a flat configuration as depicted in FIG. 7 . The resulting flat blank can then folded about the fold region 46 , and then the steps of cutting and attaching the underwires and the shoulder straps 30 can be peformed. In this case, the torso strap 26 is formed in two halves and fastener members 28 , 30 are attached to the ends of the two halves as with the brassiere 10 of FIG. 2 . This fabrication method enables the girth of the torso strap to be reduced from the full girth of the fabric tube 40 , if desired. The flat fabric blank of FIG. 7 can be boarded, if desired, to make it lay flat and to take out wrinkles. The turned welt 42 or welts can facilitate handling the blank during the boarding and other processes, and also prevent the edges of the blank from curling and raveling. Preferably, the breast cups 14 are molded after the fabric tube 40 is slit and breast cup panels are folded about the fold region 46 , so that the breast cups are shaped with a desired contour. To this end, the fabric at least in the breast cup regions includes a heat-settable yarn. Molding can be performed on a conventional molding device, which generally includes a heated convex form and a frame that stretches the fabric over the form so that the heat-settable yarn is softened while in the stretched condition. After softening, the fabric is removed from the form and the heat-settable yarn cools so as to permanently retain the contoured shape of the breast cup. If desired, one two-ply breast cup may be placed over the other two-ply breast cup prior to molding so that both cups are molded simultaneously. It is also possible to fabricate a blank for the brassiere by circularly knitting a two-ply fabric tube. The tube is essentially knit as one long turned welt by knitting a first series of courses that will become an outer ply of the blank and by knitting a second series of courses that will become the inner ply of the blank. For example, the tube can be knit on a circular knitting machine having cylinder needles and dial needles, the cylinder needles being used to knit the first series of courses and the dial needles being used to knit the second series of courses. The knitting of two-ply tubes is a process known to those of skill in the art, and hence is not further described herein. By knitting the tube as a two-ply structure, the tube does not require turned welts at the ends such as included with the previously described one-ply tube, and the blank comes off the knitting machine as a two-ply structure so as to eliminate the need to fold the blank before cutting. The present invention has many advantages. For instance, the smooth upper medial edge 38 on each of the breast cups 14 and the smooth bottom edge 50 of the torso strap 16 minimize the amount of stitching and or banding needed to form the brassiere 10 . Banding and seams tend to show through clothing, creating unsightly lines, especially when in contact with the clothing, such as on the top edge of a breast cup immediately beneath a blouse or shirt. Avoiding the use of seams and/or banding on the upper edge of the breast cup where a blouse or top generally makes close contact therefore improves the aesthetic appearance of the wearer. In addition, elimination of banding and stitching tends to reduce the effort and cost of constructing the brassiere 10 . Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

A brassiere for extending around a wearer's torso and supporting the wearer's breasts. The brassiere includes a torso strap supporting a pair of breast cups which in turn support the wearer's breasts. The breast cups are constructed of a two-ply fabric, preferably a circularly knit fabric, and each of the breast cups has a fold line positioned along at least a portion of its top edge so as to improve wearer comfort and reduce seams visible through clothing. Also, an underwire may be attached to an exterior side of one of the plies of the two-ply material of each of the breast cups to provide extra support. Optionally, the fold may be knit to have a thinner material than the remaining plies to facilitate formation of a smooth folded upper edge of the breast cup with a finished appearance.

STATEMENT REGARDING PRIOR DISCLOSURES The present application claims the grace period exception under AIA 35 USC §102(b)(1)(A) to Korean Patent Registration No. 10-1559077 (published on Oct. 8, 2015), which is hereby incorporated by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball check valve apparatus, and more particularly to a ball check valve apparatus that is installed in a wastewater pipe to prevent wastewater from flowing backwards. 2. Description of the Related Art In general, a check valve apparatus installed in a wastewater pipe according to the related art includes a structure that has a flip type opening/closing member mainly having a thin disk such that the interior of a pipe is selectively opened and closed while the opening/closing member is rotated forward or rearward. However, as the opening/closing member of the check valve apparatus according to the related art is frequently opened and closed, fatigues are accumulated in the opening/closing member and thus, a hinge of the opening/closing member is frequently damaged. Furthermore, a damage and impact noise are generated due to an excessive water impact when the opening/closing member closes the pipe, and solids contained in wastewater are interposed between the opening/closing member and the inner side of the pipe, making the operation of the opening/closing member unsmooth. Moreover, because the check valve apparatus according to the related art separately includes a valve seat structure for supporting the opening/closing member, the structure of the check valve apparatus is complex so that the check valve apparatus cannot be easily manufactured and maintained, causing an increase in the price of the product due to deterioration of productivity. SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above-mentioned problems, and provides a ball check valve apparatus that is installed to a wastewater pipe to reduce noise and damages to the ball check valve apparatus with a simple structure. In accordance with an aspect of the present disclosure, there is provided a ball check valve apparatus including: a first body into which wastewater is introduced; a second body coupled to the first body to be communicated with the first body and configured to discharge the wastewater introduced into the first body; and a valve member disposed in the first body to be elevated and configured to close an opening/closing hole formed in the first body by the self-weight thereof and open the opening/closing hole by a pressure of wastewater introduced through the opening/closing hole. The valve member may include a spherical opening/closing part seated at a periphery of the opening/closing hole, a connection part vertically extending from an upper side of the opening/closing part, and a guide ring disposed to be perpendicular to the connection part and having a pair of through-holes through which wastewater passes. The ball check valve apparatus may further include a weight balancing boss vertically extending from a lower end of the opening/closing part. The weight balancing boss may have an inverse conic shape. The diameter of the guide ring may be larger than the diameter of a discharge hole formed in the second body. According to the present invention, a separate hinge structure can be excluded from the valve member, and because, a valve seat structure of the valve member is provided in the first body 20 itself, the overall structure thereof can become simple and the ball check valve can be easily manufactured and maintained. Furthermore, according to the present invention, because the opening/closing part of the valve member has a spherical shape to improve durability, damage to the ball check valve apparatus due to a water impact cause by the flows of the wastewater when the valve member is opened and closed can be reduced and noise can be reduced. Because a hinge structure is excluded from the valve member and the valve seat structure of the valve member is provided for the first body, the overall structure of the ball check valve apparatus can be simplified and can be easily manufactured and maintained. In addition, according to the present invention, because the opening/closing part of the valve member has a spherical shape to improve durability, damage to the ball check valve apparatus due to a water impact can be reduced and noise can be reduced when the valve member is opened and closed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view illustrating a ball check valve apparatus according to an embodiment of the present invention; FIG. 2 is a plan view illustrating a valve member of FIG. 1 ; FIGS. 3 and 4 are sectional views illustrating coupled states in which an opening/closing hole is opened and closed as the valve member of the ball check valve apparatus according to the embodiment of the present invention is lifted and lowered; and FIG. 5 is a perspective view illustrating another example of the valve member of FIG. 1 . DETAILED DESCRIPTION OF THE INVENTION Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the embodiment described in the following is merely exemplary to help understanding of the present invention and may be variously modified differently from the embodiment of the present invention described herein. Meanwhile, in a description of the present invention, a detailed description and a detailed illustration of the known functions and configurations may be omitted to avoid making the essence of the present invention obscure. Further, the elements are not illustrated in actual scales but some of the elements may be exaggerated to help understanding of the present invention. Referring to FIGS. 1 to 3 , a ball check valve apparatus 10 according to an embodiment of the present invention includes a first body 20 , a second body 30 , and a valve member 40 . The first and second bodies 20 and 30 are disposed between first and second wastewater pipes 51 and 53 (see FIG. 3 ) for feeding wastewater discharged from a wastewater collection tank (not illustrated). A lower part 35 of the second body 30 is separately inserted into an upper part 21 of the first body 20 . In this case, an accommodation space 21 a that defines a movement space in which a valve member 40 may be elevated is formed inside the upper part 21 of the first body 20 . The accommodation space 21 a also acts as a passage through which wastewater passes. The upper part 21 of the first body 20 is inclined such that a lower end 21 b of the first body 20 becomes gradually narrower as towards the center of the first body 20 . Accordingly, an opening/closing hole 22 opened and closed by the valve member 40 is formed inside the first body 20 . A periphery of the opening/closing hole 22 acts as a valve seat in which a valve member 40 may be seated. A screw part 26 is formed at an outer periphery of the lower part 23 of the first body 20 to be screw-coupled to a first wastewater pipe 51 . In this case, a hexagonal protrusion 25 , with which the head of a spanner (not illustrated) may be fitted, is formed such that the first body 20 may be easily screw-coupled to a first wastewater pipe 51 (here, the first wastewater pipe 51 is directly communicated with a pump (not illustrated)). Moreover, although it is illustrated in the embodiment of the present invention that the screw part 26 of the first body 20 is connected to the first wastewater pipe 51 , the present invention is not limited thereto but the screw part 26 may be directly coupled to the pump (not illustrated). In this case, because a common pump generally has a female thread at an inner periphery of a coupling hole (not illustrated), to which a pipe is connected, it is preferable that the screw part 26 has a male thread in this aspect. As described above, the lower part 35 of the second body 30 is inserted into the upper part 21 of the first body 20 . The second body 30 has a coupling hole 33 , to which one end of a second wastewater pipe 53 is inserted, inside an upper part 31 of the second body 30 . A discharge hole 34 communicated with the accommodation space 21 a of the first body 20 is formed inside the second body 30 . In this case, it is preferable that the diameter of the discharge hole 34 is smaller than the diameter of a guide ring 45 of the valve member 40 . This structure prevents the valve member 40 from deviating from the accommodation space 21 a of the first body 20 when the valve member 40 is moved upwards by a hydraulic pressure of the wastewater. The valve member 40 includes an opening/closing part 41 , a connection part 43 , a guide ring 45 , and a weight balancing boss 48 . The opening/closing part 41 closes the opening/closing hole 22 of the first body 20 by the self-weight thereof (see FIG. 3 ), and in contrast, opens the opening/closing hole 22 while rising due to the pressure of the wastewater introduced through an interior space 23 a of the lower part 23 of the first body 20 (see FIG. 4 ) The connection part 43 is formed to be substantially perpendicular to the upper side of the opening/closing part 41 , and supports the guide ring 45 and spaces the guide ring 45 to the upper side of the opening/closing part 41 such that the guide ring 45 maintains a predetermined interval with the opening/closing part 41 . In this case, it is preferable that the connection part 43 has a substantially plate shape and has a thin plate shape not to be interfered by the flows of the wastewater that passes through the accommodation space 21 a of the first body 20 through the opening/closing hole 22 . The guide ring 45 is disposed substantially horizontally, and a pair of through-holes 46 a and 46 b are formed by the connection part 43 as illustrated in FIG. 2 . Various solids contained in the wastewater as well as the waste water pass through the pair of through-holes 46 a and 46 b As illustrated in FIG. 4 , the spherical opening/closing part 41 that is lifted by a pressure as the wastewater is introduced through the opening/closing hole 22 is not rotated but lifted substantially vertically by the guide ring 45 . The weight balancing boss 48 extends vertically downwards from a lower end of the opening/closing part 41 . In this case, the weight balancing boss 48 is disposed in the vertical direction as that of the connection part 43 . Because the weight balancing boss 48 acts as a weight pendulum, the center of weight of the opening/closing part 41 may be situated on the lower side of the center of the opening/closing part 41 when the opening/closing part 41 is elevated such that the posture of the opening/closing part 41 is maintained together with the aforementioned guide ring 45 . Referring to FIG. 5 , the opening/closing member 40 a may has a weight balancing boss 48 a having a different shape from the aforementioned weight balancing boss 48 of the opening/closing member 40 . The weight balancing boss 48 a may have a substantially inverse conic shape at a lower end of the opening/closing part 41 . In this way, when the weight balancing boss 48 a is manufactured to have an inverse conic shape, the wastewater introduced into the opening/closing hole 22 may be guided upwards while the interference with the outside of the opening/closing part 41 along an outer peripheral surface of the weight balancing boss 48 a is minimized. Accordingly, the flows of the wastewater that passes through the accommodation space 21 a of the first body 20 may become smoother. As described above, because a hinge structure is excluded from the valve member 40 and the valve seat structure of the valve member 40 is provided for the first body, the overall structure of the ball check valve apparatus can be simplified and can be easily manufactured and maintained. In addition, according to the present invention, because the opening/closing part 41 of the valve member 40 has a spherical shape to improve durability, damage to the ball check valve apparatus due to a water impact can be reduced and noise can be reduced when the valve member 40 is opened and closed. Although the present invention has been with reference to the limited embodiment and the drawings, the present invention is not limited thereto, but it should be noted that the present invention can be variously corrected and modified by those skilled in the part to which the present invention pertains within the technical spirit of the present invention and the equivalents of the claims, which will be described below.

Provided is a ball check valve apparatus including: a first body into which wastewater is introduced; a second body coupled to the first body to be communicated with the first body and configured to discharge the wastewater introduced into the first body; and a valve member disposed in the first body such that the valve member is movable up and down in the first body and configured to close an opening/closing hole formed in the first body by a self-weight thereof and open the opening/closing hole by a pressure of wastewater introduced through the opening/closing hole.

BACKGROUND OF THE INVENTION 1. Field Of The Invention This invention relates to devices which can detect a small loss of refrigerant charge from refrigeration systems while in operation, and function to trigger an audible and/or visual alarm during any time the system is operating. 2. Description Of The Related Prior Art The need for a method and apparatus to determine the amount of refrigerant in a refrigeration system, particularly a large system, has long been recognized. There are several reasons why this measurement is important, but the main concern for most refrigeration systems is the need to detect a low refrigerant condition as the result of a steady loss of refrigerant over time due to leaks in the pressurized system. A low refrigerant condition initially results in a gradual loss of cooling capacity which, if not detected and corrected, can result in such a critical loss of refrigerant that expensive damage can occur to a refrigerant compressor due to lubrication failure. U.S. Pat. No. 4,553,400, issued Nov. 19, 1985 to Michael A. Branz, discloses a comprehensive refrigerant monitor and alarm system with emphasis on the electrical and electronic features of the system. When adapted to commercial refrigeration systems for supermarket display cases, it is seen that the level of refrigerant in a large common receiver is to be monitored by a conventional liquid level sensing float. A liquid level indicator provides a constant readout of the level in the receiver, triggers a timer controlled alarm when a critically low level is reached. By contrast, the present invention reliably detects a loss of refrigerant at a convenient, accessible location which can be located remotely from the receiver. U.S. Pat. No. 4,308,725, issued Jan. 5, 1982 to Tsuneyuki Chiyoda discloses a simplistic device for detecting the quantity of refrigerant in a liquid receiver. In one embodiment, a floating hollow ball within a float guide can rise or fall with the refrigerant level, and as the level drops due to the loss of refrigerant, ultimately the ball comes in contact with a pair of electrical conducting elements, and the ball, being made of conductive material, then completes an alarm circuit through the contacts to energize an external alarm. An ingenious electronic circuit filters out very short electrical contact times in the detector which may be caused by mechanical vibrations. The positive make-or-break characteristics of the switching device of the present invention renders it largely immune to such rapid short contact times, as would be induced by mechanical vibration. U.S. Pat. No. 4,745,765, issued May 24, 1988 to Edward D. Pettitt, discloses a refrigerant detecting device which illustrates a new inventive trend in liquid level sensors. This type of sensor responds to "condition sensing" and can determine a low refrigerant charge level without actually being located within or near a receiver containing the bulk of the liquid charge. This condition sensing device, located in the discharge line from an evaporator, detects refrigerant super heat temperature and also contains a bi-metal ambient air temperature sensor. An internal electrical contact closes to activate an alarm when a predetermined combination of evaporator super heat and ambient air temperature occurs indicating an undesirably low amount of refrigerant in the system. It is a complex precision device compared to the simplicity of the present invention. U.S. Pat. No. 4,856,288, issued Aug. 15, 1989 to Robert C. Weber, discloses a refrigerant detection device which is to be installed at a predetermined location in a refrigerant high pressure liquid line. It consists of a preferably transparent hollow cylinder, a few inches in height in which a float of conductive material is disposed. As the conductive float follows the liquid level down in the cylinder, it eventually reaches a pair of electrically conductive contact points and thereby completes an electrical circuit which is indicative of refrigerant loss and therefore can activate a refrigerant low level alarm. Several embodiments of the invention are disclosed including versions having two conductive floats. A time delay means is suggested to avoid activation of the alarm during the compressor startup phase. The conductive float sensor of this invention may be subject to short, rapid electrical contact times which can be caused by mechanical vibrations, same as referred to above for the Chiyoda Patent, but the present invention is immune to the effects of mechanical vibration and the resultant rapid contact cycling. None of the above inventions and patents taken either singly or in combination, is seen to describe the instant invention as claimed. SUMMARY AND OBJECTS OF THE INVENTION By the present invention, an improved low cost reliable refrigerant loss detector is disclosed and claimed. It is capable of detecting the loss of a small amount of refrigerant in a closed system compared to the total system capacity. It is further provided with an electrical circuit containing a time delay apparatus which acts to prevent unnecessary and undesired false alarm signals, during transient refrigeration conditions which occur during the first minute of system operation. An audible alarm and/or visual alarm may sound after one minute, signaling a low refrigerant condition, and the alarm will continue as long as the refrigeration compressor is operating and the low refrigerant condition persists. Accordingly, it is a principal object of the present invention to provide a refrigerant loss detector which may be mounted at a point in a closed system remote from the refrigerant receiver, and which reliably determines that a small amount of refrigerant charge in the closed system has been lost. It is another object of the present invention to provide a refrigerant loss detector that can initiate and maintain an electrical circuit to an audible or visual alarm during continued operation of a refrigeration compressor in a system in which a loss of refrigerant has been detected. It is a further object of the present invention to include an interval time delay apparatus which functions to prevent the transmission of false alarm signals which may be initiated by the loss detector during the unstable, non-typical refrigerant conditions which exist during the brief system startup phase. Still another object of the present invention is to provide a refrigerant loss detector which can be readily installed in a refrigerant liquid line either by an original equipment manufacturer (OEM) at the factory, or by tradesmen during construction of a new system, or as a retrofit to an existing system. It is an object of the present invention to energize the refrigerant loss detector and alarm circuitry and maintain it in a monitoring status continuously during the time that the refrigeration compressor is operating. It is an object of the present invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purpose. These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-section elevational view of an embodiment of the refrigerant loss detector in which the float is buoyant at a high level of refrigerant. FIG. 2 is a cross-section elevational view of the embodiment of FIG. 1 in which the float is buoyant at a lower level of refrigerant. FIG. 3 is a cross-section elevational view of the buoyant float and mercury switch assembly. FIG. 4 is a top view of the loss detector removable cap. FIG. 5 is a wiring schematic of the refrigerant loss detector and alarm system. FIG. 6 is a piping schematic of a typical commercial refrigerant system showing the refrigerant loss detector installed. Similar reference characters denote corresponding features consistently throughout the attached drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The instant invention includes five major components, as shown on FIG. 5. Electric contacts in the compressor operating control 12 provide the source of power, generally 110 volts or 220 volts A.C. The loss detector 10 and alarm system are operational whenever the compressor operates. The control transformer 14 steps down the primary voltage which is generally 110 volts or 220 volts A.C., to a secondary voltage of 24 or 30 volts A.C. or D.C., which powers the warning device 16 through a time delay device 18 and the refrigerant sensor 10. The warning device 16 may produce an audible signal, such as a bell or horn, or a visual signal, or both, or an automatic printout. Refrigerant sensor 10 will be further described herein. Since the refrigerant loss detector 10 will be incorporated into standard closed loop refrigeration systems, the system of FIG. 6 will be explained in some detail as background for understanding the operating principles and preferred embodiment of the instant invention. A closed loop refrigeration system 20 including a refrigerant loss detector device 10 embodying the present invention is shown in FIG. 6. This system could apply to any large refrigeration system utilizing a liquid/vapor phase change refrigerant, examples of which include such materials as halogenated fluorocarbons (freon), ammonia, and sulfur dioxide. For a general application, the refrigerant system shall be considered a so-called "split system", one in which the refrigeration evaporator 22 apparatus is remotely located from the refrigerant compressor 24 and condensing apparatus 26. The refrigerant is a halogenated fluorocarbon (freon) for the preferred embodiment. Halogenated fluorocarbons are the most common refrigerants in use today. The description of FIG. 6 begins with the evaporator 22, of well known fin and tube construction, not further described herein. Air from the conditioned space moved by a power driven fan 28, passes across the heat transfer surface of the evaporator 22 wherein a refrigerant, having a boiling temperature that is lower than the temperature of the space to be cooled, permits the transfer of heat from the air passing through the evaporator 22 to the boiling refrigerant therein. The boiling refrigerant referred to undergoes a phase change from a liquid to a gas during this process. The liquid, now vaporized and exiting from the evaporator 22, courses through an accumulator 30 where any unvaporized liquid exiting from the evaporator is separated out. The refrigerant gas is then withdrawn from the accumulator 30 and enters the compressor 24 wherein both the pressure and the temperature of the gas are sharply increased. The now compressed refrigerant gas exiting from the compressor 24 at its discharge pressure has a saturation temperature low enough that it may be condensed in the condenser 26 by the condensing medium, usually air, as in this embodiment, but may also be water, using a suitable shell and tube heat exchanger (not shown) which is well known in the art. The vaporized refrigerant is condensed to a liquid in the condenser 26, from which the heat of vaporization is removed by ambient air circulated through the condenser 26 by fan 32. Excess liquid refrigerant is stored in receiver 34 and, upon demand of the throttling device or expansion valve 40, refrigerant will flow from the receiver 34 through filter dryer 35, sight glass 38, the refrigerant detector 10 of the instant invention and then through the expansion valve 40 completing the circuit into the evaporator 22. All of the above stated components are well known in the refrigeration art, except for refrigerant detector 10. As explained above, the pressure of the refrigerant gas leaving the compressor 24 and entering the condenser 26 need be great enough that the refrigerant exiting the condenser will have been liquified. Under a "standard operating condition" of 95 degrees F. ambient air temperature, with air as the cooling medium, and using R-22 as the refrigerant, the compressor 24 will need to discharge the refrigerant gas at a pressure of at least 230 pounds per square inch gauge, in order to assure that the refrigerant in the piping between the condenser 26 and the expansion valve 40 remains liquid. Upon a gradual loss of refrigerant from the system, the compressor is handling a reduced mass flow rate, and as a result the design discharge pressure can no longer be maintained. While the discharge pressure is falling, the condensing temperature does not fall proportionately; it can fall no lower than the ambient air temperature, using air as the cooling medium in this case. Thus, through leakage, the liquid refrigerant pressure is gradually falling toward the pressure at which it will flash into vapor, the vaporization pressure. Referring to FIG. 1, a preferred embodiment of the refrigerant sensor 10 comprises a generally vertical canister 42, within which is disposed a buoyant member 44 containing an inexpensive, sealed mercury switch 46 of the type generally used in the electronic industry to deactivate electrical circuits in the event of equipment tip over. The mercury switch 46 is connected through insulated copper conductors 48 within the vertical canister 42, and final connections being 1/64 inch thick copper braid 1/4 inch in length to provide hinge type flexible connections 48A. The insulated conductors are connected to spade type electrical connectors 50, suitably mounted in insulated plug-like members 52. The top 54 of canister 42 is threadably removable from the canister. An `O` ring 56 provides pressure sealing for the removable top 54. The refrigerant detector 10 is in communication with the liquid refrigerant through two tubular ports 58, and, preferably, is mounted as shown in FIG. 6, in a pressurized liquid line between the sight glass 38 and the expansion valve 40. Consequently when liquid refrigerant enters refrigerant detector 10 at a pressure close to the vaporization pressure, vapor bubbles will be forming and collecting in the top most volume of the canister 42 of sensor 10. Gradually the vapor will displace the liquid surface downward causing the buoyant member 44 to descend (FIG. 2) and also display a partial rotation owing to the restraint of the conductors 48. As shown in FIG. 2, the mercury bead 64 will move so as to bridge the two electrodes 60 and 60a (see FIG. 3), providing a positive electrical "make" circuit through the mercury switch 46. Referring to FIG. 5, a make circuit in refrigerant detector 10 completes a series electrical circuit from the transformer 14 secondary (not shown) through the time delay device 18 and also through the warning device 16. During the timed interval, the electronic time delay device provides only a weak current through the warning device 16, insufficient to activate it. After the delay period, full current flows from the secondary of the control transformer 14, through the time delay device 18, the refrigerant detector 10, and warning device 16 causing the warning device 16 to activate. As mentioned previously, the warning device 16 may be either audible, visual or a printout on a recording device. It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.

A refrigerant loss detector and alarm, the detector device suitable for installation in the piping of a refrigeration system which utilizes a liquid/vapor phase change substance as the refrigerant. Upon detection of refrigerant vapor accumulating in the loss detector, thereby displacing refrigerant liquid therefrom, the orientation of a float element containing a mercury switch is affected. Upon a fall in refrigerant liquid level in the loss detector, the mercury switch becomes activated, thereby completing an external electrical circuit which contains a time delay device and an alarm device.