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The mechanical instability of the Solid Electrolyte Interphase (SEI) layer in lithium ion (Li-ion) batteries causes significant side reactions resulting in Li-ion consumption and cell impedance rise by forming further SEI layers, which eventually leads to battery capacity fade and power fade. In this paper, the composition-/structure-dependent elasticity of the SEI layer is investigated via Atomic Force Microscopy (AFM) measurements coupled with X-ray Photoelectron Spectroscopy (XPS) analysis, and atomistic calculations. It is observed that the inner layer is stiffer than the outer layer. The measured Young's moduli are mostly in the range of 0.2–4.5 GPa, while some values above 80 GPa are also observed. This wide variation of the observed elastic modulus is elucidated by atomistic calculations with a focus on chemical and structural analysis. The numerical analysis shows the Young's moduli range from 2.4 GPa to 58.1 GPa in the order of the polymeric, organic, and amorphous inorganic components. The crystalline inorganic component (LiF) shows the highest value (135.3 GPa) among the SEI species. This quantitative observation on the elasticity of individual components of the SEI layer must be essential to analyzing the mechanical behavior of the SEI layer and to optimizing and controlling it. | battery |
Abstract Climate change mitigation requires the development of new processes to reduce the amount of carbon dioxide in the atmosphere. The products of CO2 utilization can supplement or replace chemical feedstocks, fine chemicals, pharmaceutical, and polymers. Carbon capture and utilization based on innovative electroreduction processes is one of the suggested routes to reduce the use of coal and oil as carbon sources due to the recycling of carbon. Some chemicals may be produced using carbon dioxide, decreasing the use of natural resources. The electrocatalytic processes to obtain formate and methanol as derived products from CO2 are discussed in this chapter, taking into account the electro-catalysts and the reactor design in the development of innovative processes. | non-battery |
Publisher Summary This chapter reviews several energy-aware design techniques for controlling both active and standby power consumptions that are applicable to MPSoCs. The techniques discussed are for multiprocessor systems-on-chips (MPSoC) processor cores, the on-chip memory hierarchy, the on-chip communication system, and MPSoC energy-aware software. The majority of the techniques are derived from existing uni-processor energy-aware systems that take on new dimensions in the MPSoC space. Techniques for energy and power consumption reduction are successfully applied at all levels of the design space in uni-processor systems—circuit, logic gate, functional unit, processor, system software, and application software levels. The primary focus has been on reducing active power. As technology continues to scale up, accompanied by reductions in the supply and threshold voltages, the percentage of the power budget due to standby energy has driven the development of additional techniques for reducing standby energy. | non-battery |
The full-length Schedule for Nonadaptive and Adaptive Personality - 2nd Edition (SNAP-2, Clark et al. 2014) and various derivative versions were developed as measures of normal- and pathological-range personality traits. We report herein on the development and initial validation of the SNAP Brief Other-Description Rating Form (SNAP-BORF), an abbreviated version of the SNAP Other-Description Rating Form (ORF; Harlan and Clark Assessment, 6, 131–145, 1999). Our goal was to create a more efficient SNAP informant short form by making items more succinct rather than by eliminating items. SNAP-ORF word count was reduced by 68%, and the 1.5-page SNAP-BORF can be completed in approximately 10 min, one-third to one-half the time required to complete the SNAP-ORF. Mean-level differences between the SNAP-ORF and SNAP-BORF scales were negligible for all scales except propriety. Using exploratory factor analysis, we found the SNAP-BORF had a three-factor structure (NA vs. Low PA, Disinhibition vs. Constraint, and Antagonism) broadly consistent with extant literature. The SNAP-BORF showed good convergent/ discriminant validity with respect to the SNAP-family measures as well as measures of normal personality and symptoms of depression, anxiety, and worry. Results indicated that the SNAP-BORF is a useful measure when a very brief informant assessment of adaptive and maladaptive personality is needed.
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Single phase Li4Ti5O12 powder with porous particle structure is synthesized via a simple, mild and productive citric-acid combustion method. The Li4Ti5O12 particle is composed of submicro-scaled grains with size of 100–200nm. The synthesized Li4Ti5O12 shows high reversible capacity (ca. 165mAhg−1 at 0.5C), excellent rate-capability (ca. 115 and 100mAhg−1 at 10 and 20C, respectively) and high temperature cycling stability (50°C). Under expanded cut-off voltage range of 0.01–2.5V, it delivers a high specific capacity of ca. 230 and 170mAhg−1 at 0.5 and 10C, respectively, while maintaining an excellent cycling stability. The synthesized Li4Ti5O12 shows fast de-lithiation but slow lithiation kinetic processes. When discharged at constant 1C while charged at 10, 20 and 30C, respectively, the specific capacity of 162, 160 and 158mAhg−1 can be achieved. The excellent electrochemical performance of the combustion synthesized Li4Ti5O12 is ascribed to the porous particle structure and small grain size feature, which ensure the good contact with electrolyte and reduce the lithium ion/electron diffusion distance, and therefore enhance the electrode reaction process. | battery |
The cells applied with a three-dimensionally (3D) patterned Li4Ti5O12 (LTO) electrode showed good performance as a rechargeable lithium-ion battery. The 3D-patterned electrode was fabricated with a printing apparatus and has many lined patterns with a high aspect ratio standing in line on a current collector. The cell using 3D-patterned electrode showed much better rate capability than that using a conventional flat electrode. In this research, cyclic voltammetry was carried out to investigate the mechanism realizing the high rates of charging and discharging in 3D-patterned electrode. Various types of line patterns were fabricated for 3D electrode by using LTO electrode slurry, and the influences of basic specifications of electrode structure (the space between two neighboring electrode lines, the height and width of electrode) on the charge and discharge characteristics were evaluated to optimize the electrode pattern. In addition, the electrode performance was discussed from the viewpoints of ohmic resistance and charge-transfer resistance of the cells with 3D-patterned and conventional flat electrodes. | battery |
The effect of potential cycling conditions on redox processes observed in the potential region of electrochemical stability window, between hydrogen and oxygen evolution reactions, of platinum, gold and glassy carbon electrodes has been investigated in aqueous lithium bis(trifluoromethylsulfonyl)imide (LITFSI) solutions with concentration ranging from 1 to 21 molal (moles of salt/kg of water). Following potential cycling to positive potential upon which oxidation of Pt is barely observable in contrast to Au, which is characterized by a well-defined oxidation wave, both electrodes showed on the return scan a cathodic wave corresponding to the electrochemical reduction of corresponding metal oxides. In the potential region more negative than about 0 V, voltammograms recorded by avoiding scanning to a positive potential limit reaching the onset of the oxygen evolution reaction, show no well-defined cathodic waves prior to hydrogen evolution reaction. This provides strong evidence that TFSI anions are not electrochemically reduced in this potential region at Pt, Au and glassy carbon electrodes. Furthermore, X-ray photoelectron spectroscopy measurements of electrode surface, following potential cycling to a value negative enough to reach the onset of hydrogen evolution, showed formation of surface layer with a high fluorine/sulfur ratio (higher than 3 expected for TFSI) that could be explained by chemical degradation of TFSI by species generated during hydrogen evolution with preferential dissolution of sulfur-based compounds. | battery |
A single phase of LiMn1−x Fe x PO4(OH) with the tavorite structure is synthesized by a H+/Li+ exchange reaction of Mn1−x Fe x PO4·H2O precursors and LiNO3 in the composition range 0≤ x ≤0.3. The materials are characterized by X-ray diffraction, thermogravimetry–differential thermal analysis, scanning electron microscopy, and charge–discharge measurements. Rietveld refinement results of synchrotron X-ray powder diffraction data reveal that LiMn1−x Fe x PO4(OH) forms a continuous solid solution over the entire composition range with a triclinic structure (space group: P–1). A linear reduction in the unit cell dimensions a and b and a linear increase in the cell parameter c are accompanied by a local change in the bonding geometry of M 3+O6 and LiO6 octahedra with increasing iron content. Iron-substituted phases exhibit an improved charge–discharge performance with a 30% increase in capacity for voltages in the range of 2.0–4.6V as the iron content increases from x =0.0 to 0.3. The improved electrochemical properties and thermal stability reveal a correlation with distortion relaxation in the local geometry caused by partial substitution of Mn3+ by Fe3+ in LiMnPO4(OH). | battery |
Lithium–chromium–manganese oxides, LiMn x Cr1−x O2 (0≤x≤0.6), were synthesized as solid solutions by simple calcination of emulsion-dried powder precursor. The product was well crystallized to an α-NaFeO2 structure (space group: R 3 ̄ m). By combination of Rietveld analysis of X-ray diffraction data and X-ray absorption near edge structure (XANES) techniques, the final product is considered to be [LiI]3a oct[Mn x IIICr1−x III]3b oct[O2]6c (0≤x≤0.6). The prepared oxides were electrochemically active, and capacity as cathode materials for lithium-ion battery was improved with increasing Mn substitution amount. | battery |
This paper reviews the system components, modeling, and control of microgrids for future smart buildings in current literature. Microgrids are increasingly widely studied due to their reliability in the event of grid failure or emergency, their incorporation of renewable energy sources, and the potential they represent for overall cost reduction for the consumer. Greater accuracy in microgrid modeling enables the design of more advanced control methods, resulting in better objective optimization. This paper begins with an overview of microgrids and their components, their importance to both utility providers and building owners, and typical problems that they may be used to solve, as well as modeling challenges that microgrid researchers may face. An overview of microgrid control and optimization is given in terms of objectives, constraints, and optimization methods. Microgrid modeling is a complex task due to the number, variety, and complexity of microgrid components, which can include building loads, distributed energy resources, and energy storage systems. Various component modeling methods including physics-based and data-driven models are reviewed, to include battery degradation models. Furthermore, this paper provides a review of various data-driven forecasting methods for the microgrid controls. Different types of control methods including rule-based and model predictive control are reviewed, including latest occupancy-based model predictive control for buildings. Lastly, a discussion of current challenges that may be faced by researchers is presented, as well as future directions. | battery |
Owing to data collection challenges, the vertical variation in population in cities and particulate air pollution are typically not accounted for in exposure assessments, which may lead to misclassification of exposures based on elevation of residency. To better assess this misclassification, the vertical distribution of the potentially highly exposed population (PHEP), defined as all residents within the 100-m buffer zone of above-ground highways or the 200-m buffer zone of a highway-tunnel exit, was estimated for four floor categories in Boston’s Chinatown (MA, USA) using the three-dimensional digital geography methodology. Vertical profiles of particle number concentration (7–3000 nm; PNC) and particulate matter (PM2.5) mass concentration were measured by hoisting instruments up the vertical face of an 11-story (35-m) building near the study area throughout the day on multiple days. The concentrations from all the profiles (n=23) were averaged together for each floor category. As measurement elevation increased from 0 to 35 m PNC decreased by 7.7%, compared with 3.6% for PM2.5. PHEP was multiplied by the average PNC for each floor category to assess exposures for near-highway populations. The results show that adding temporally-averaged vertical air pollution data had a small effect on residential ambient exposures for our study population; however, greater effects were observed when individual days were considered (e.g., winds were off the highways). | non-battery |
Thin films of lithium iron phosphate (LiFePO4, LFP), with a thickness between 80 nm and 320 nm are prepared by ion beam sputter deposition. X-ray diffraction, transmission electron microscopy, and electron energy loss spectroscopy show that the films exhibit the desired structure, morphology, and chemical composition. Chrono potentiometry and cyclic voltammetry are carried out to determine the electrochemical behavior of the LFP films. Within these electrochemical measurements, a well-defined lithium intercalation/deintercalation reaction at around 3.45 V vs. Li/Li+ and a specific capacity of 104 mAh g−1 are observed. Moreover, a quite high cycling stability is found: Measurement data at 1C rate indicate a capacity fading of only 20% after ≈1700 charge–discharge cycles. In addition, the diffusion of lithium within the LFP thin films is studied by cyclic voltammetry and galvanostatic intermittent transition technique. Within these measurements it is observed that the lithium kinetics in the sputter-deposited thin films is about two orders of magnitude faster, compared to the powder material and thin films deposited by pulsed laser deposition. This behavior may be explained by the strong texture of the sputtered films. | battery |
Grafting is commonly used to relieve damage caused by soil-borne diseases and to enhance the nutrient uptake in watermelon plants. Certain reports have shown the proteomic changes of plant tissues involved in grafting, while little information about the secretome after watermelon grafting is available. To gain insight into the root-secreted protein profile, root exudates of three types of seedlings (own-root watermelon (W), grafted-root watermelon (WB) and own-root bottle gourd (B)) were collected under hydroponic conditions, desalted and concentrated using Amicon ultracentrifugal filter devices, and separated by one-dimensional SDS–PAGE. Principal component analysis revealed that the protein profile was distinctly altered after grafting, and the diversity of root-secreted proteins of WB was significantly higher than that of W and B. Moreover, analysis by LC-QTOF/MS/MS revealed that some proteins associated with biotic and abiotic stress resistance appeared in response to grafting, such as disease resistance protein At4g27190, callose synthase, HVA22, and Clp protease. These results indicate that grafting can shift the root-secreted protein profile and thus could increase stress resistance. This study would help to reveal the mechanisms of disease resistance and growth promotion achieved through grafting. | non-battery |
The ever-present challenge of matching polymer electrolyte to electrode in making any type of electrochemical device is addressed herein. Since fundamental experimental data on the structural nature of the polymer–inorganic interface at the atomic level is scarce (not to say non-existent), molecular dynamics simulation can give the first suggestive insights into how an idealized interface — here between PEO and double-layered V2O5 gel – can behave. The model simulated here (at a nominal 400 K) comprises ca. 20 Å-thick slabs of PEO and 15 Å-thick V2O5 gel layers arranged to form an infinite sandwich-type structure. A number of clear trends emerge: dynamical motion in both PEO and V2O5 is significantly reduced in the interface region, where it is also clear that relatively stable local structural configurations develop. These appear to be controlled by interactions between the ether oxygens of the PEO and the VO bonds which form the surface of the V2O5. Experimental confirmation of such features is lacking. | battery |
A number of review or survey articles have previously appeared on human action recognition where either vision sensors or inertial sensors are used individually. Considering that each sensor modality has its own limitations, in a number of previously published papers, it has been shown that the fusion of vision and inertial sensor data improves the accuracy of recognition. This survey article provides an overview of the recent investigations where both vision and inertial sensors are used together and simultaneously to perform human action recognition more effectively. The thrust of this survey is on the utilization of depth cameras and inertial sensors as these two types of sensors are cost-effective, commercially available, and more significantly they both provide 3D human action data. An overview of the components necessary to achieve fusion of data from depth and inertial sensors is provided. In addition, a review of the publicly available datasets that include depth and inertial data which are simultaneously captured via depth and inertial sensors is presented.
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The body mass index (BMI) of breakfast eaters is frequently reported to be lower compared with that of breakfast skippers. This is not explained by differences in energy intakes, indicating there may be other mechanisms serving to drive this paradoxical association between breakfast and BMI. This study aimed to investigate the effect of eating breakfast versus morning fasting on measures predominantly of metabolism in lean and overweight participants who habitually eat or skip breakfast. | non-battery |
Sn-doped Li3V2− x Sn x (PO4)3/C (x =0, 0.02, 0.04, 0.08) composites are prepared using an ultrasonic-assisted sol–gel method under a static inert atmosphere. The effects of Sn-doping on the structure and electrochemical performance of Li3V2(PO4)3/C are investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical measurements. The XRD patterns demonstrate that Sn-doping affects the preferred crystal growth direction of Li3V2(PO4)3. The SEM results show that the particles of the Sn-doped samples have a polyhedron shape. The particles are micron-size and present high crystallinity. The Li3V1.98Sn0.02(PO4)3/C sample, which has initial capacities of 122.7 and 117.2mAhg−1 at 0.2 and 5C between 3.0 and 4.3V, respectively, shows the best electrochemical performance among obtained samples. During Li+ de-intercalation and intercalation processes, Sn4+ could functions as a cushion bracket to protect the Li3V2(PO4)3 crystal lattice from shrinking, which greatly improves the rate performance and cycling performance of Li3V2(PO4)3. | battery |
The thermal management of batteries for use in electric and hybrid vehicles is vital for safe operation and performance in all climates. Lithium-ion batteries are the focus of the electric vehicle market due to their high power density and life cycle longevity. To investigate the performance of two liquid cooling designs for lithium-ion battery packs, a series of numerical models were created. The effects of channel number, hole diameter, mass flow rate and inlet locations are investigated on a mini channel-cooled cylinder (MCC) and a channel-cooled heat sink (CCHS); those being the two most efficient concepts. The results show that the maximum temperature can be controlled to under 313 K for both designs with mass flow rates over 5E-05 kg/s, and maximum temperature variation can be controlled to less than 3.15 K for both designs. Considering both maximum temperature and temperature uniformity, the MCC design provides superior performance to the CCHS. The maximum temperature of the MCC is less than that of the CCHS but the temperature is less uniform. The MCC is a more complex design and so would incur greater manufacturing costs. But, it increases the efficiency of such systems for the rechargeable battery packs of the electric vehicle industry. | battery |
Non-aqueous Li-O2 battery has attracted plenty of interest due to its super theoretical energy density. Nevertheless, it also faces formidable challenges with respect to an unaccepted overpotential during charge process and a low round trip efficiency, which leads to a poor cycle life. Herein, we present a novel binder-free composite cathode comprised of MgCo2O4@3D graphene with a three-dimensional structure, which has never been used in the lithium oxygen batteries, as a cathode applied in the non-aqueous Li-O 2 battery. The MgCo2O4 nanowires as the catalyst is grown on the graphene substrate supported by the nickel foam. The discharge-product Li2O2 formed with a flake-like morphology decompose at a low potential ascribed to excellent catalytic activity from MgCo2O4. Finally, we demonstrate a non-aqueous Li-O2 battery capable of operating over 480 cycles with limiting capacity and rate values at 400 mAhg−1 and 200 mAg−1. | battery |
The Li[Li(1/3−x/3)Cr x Mn(2/3−2x/3)]O2 (0.15≤ x ≤0.3) cathode materials were synthesized by sol–gel process using aqueous solutions of metal acetates and citric acid as the chelating agent. The precipitate of metal citrate was dried in a vacuum oven for 10h at 100°C. After drying, the gel precursor was calcined at 300°C for about 10h. The resulted powder was ground and heated at 900°C. The structural characterization was carried out by fitting the XRD data with Rietveld program. The samples exhibited a well defined layered structure and the unit cell parameters linearly increased with increasing chromium contents in Li[Li(1/3−x/3)Cr x Mn(2/3−2x/3)]O2 Surface morphology was determined by SEM and HRTEM and it is found that the cathode material consisted of highly ordered single crystalline particles with layered-hexagonal structure. Test cells were assembled and cycled in the voltage range of 2.0–4.9V with a current density of 7.947mA/g. Electrode with (x =0.2) delivered a high reversible capacity of around 280mAh/g in cycling. | battery |
Mice deficient in glucose-6-phosphate dehydrogenase (G6PD) cannot replenish the cellular antioxidant glutathione, which detoxifies neurodegenerative reactive oxygen species (ROS). To determine the functional consequences of G6PD deficiency, young and aging G6PD-deficient mice were evaluated for brain G6PD activity, DNA damage (comets, γH2AX), Purkinje cell loss, brain function (electrophysiology, behaviour) and lifespan. DNA comet formation was increased and Purkinje cell counts were decreased in a G6pd gene dose-dependent fashion. γH2AX formation varied by age, sex and brain region, with increased levels in G6PD-deficient young and aging females, and in aging males. Aging male G6PD-deficient mice exhibited synaptic dysfunction in hippocampal slices. G6PD-deficient young and aging females exhibited deficits in executive function, and young deficient mice exhibited deficits in social dominance. Conversely, median lifespan in G6PD-deficient females and males was enhanced. Enhanced ROS-initiated brain damage in G6PD deficiency has functional consequences, suggesting that G6PD protects against ROS-mediated neurodegenerative disorders. | non-battery |
Publisher Summary A large number of people, representing a variety of diagnostic categories exhibit self injurious behavior, including autism, childhood schizophrenia, intellectual disability, visual impairment, emotional disturbance, and learning disabilities. This chapter describes the analyses of different intervention methods for preventing self-injurious behavior and its devastating effects, such as primary, secondary, and tertiary prevention. Both prevalence studies and stimulus control studies of self-injurious behavior suggest that there are risk factors, which, if averted, would decrease the probability of onset of self-injurious behavior. The preventive techniques for averting self-injurious behavior or preventing its development would avoid much human suffering, and be much more cost-effective than current methods; however, the area of early identification and intervention with self-injurious behavior is in its infancy. With the help of the new genetics and advances in the neurobiology of self-injurious behavior, drugs can be prescribed much more effectively, with more specificity and fewer serious side effects than ever before. But, much work remains to be done to have better diagnostic instruments to guide the selection of psychotropic drugs for the appropriate complex disorder related to self-injurious behavior. The chapter also presents a variety of empirically supported, rational treatment procedures for self injurious behavior and also includes noncontingent restraint, sensory integration therapy, and multisensory environments. However, whether changing the context, in which behavior interventions occur, will be sufficient to decrease all self-injurious behavior remains to be seen. | non-battery |
The irreversible formation of zinc oxide (ZnO) in Zn–air batteries is not avoidable. Because of the formation of ZnO, the battery capacity, potential, and coulombic efficiency decrease. The low electrochemical reactivity of ZnO is the main obstacle that interferes with building an electrochemically rechargeable Zn–air battery. In this work, electrolytic additives that suppress the formation of ZnO are studied. The zincate ion (Zn(OH)4 2−) is an intermediate ion, which transforms into ZnO in basic solutions during the discharge process. Some hydroxide ions in zincate can be replaced with alkoxide and acetate ions; this resulted in a clear improvement of the reversibility of Zn–air batteries. The modification of zincate with alkoxide/acetate suppresses its transformation into ZnO, which results in improved retention of capacity in cycle tests. | battery |
A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system’s dynamic behavior, such as a dynamic air flow rate into the vehicle’s cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle’s cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid–air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semi-analytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid–air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system experimental data for solidification using paraffin wax as the PCM. Through modeling, we demonstrate the importance of capturing the airside heat exchange impact on system performance, and we investigate system response to dynamic operating conditions, e.g., air recirculation. | battery |
Observations and modeling are used to assess potential impacts of sediment releases due to dam removals on the Hudson River estuary. Watershed sediment loads are calculated based on sediment-discharge rating curves for gauges covering 80% of the watershed area. The annual average sediment load to the estuary is 1.2 Mt, of which about 0.6 Mt comes from side tributaries. Sediment yield varies inversely with watershed area, with regional trends that are consistent with substrate erodibility. Geophysical and sedimentological surveys in seven subwatersheds of the Lower Hudson were conducted to estimate the mass and composition of sediment trapped behind dams. Impoundments were classified as (1) active sediment traps, (2) run-of-river sites not actively trapping sediment, and (3) dammed natural lakes and spring-fed ponds. Based on this categorization and impoundment attributes from a dam inventory database, the total mass of impounded sediment in the Lower Hudson watershed is estimated as 4.9 ± 1.9 Mt. This represents about 4 years of annual watershed supply, which is small compared with some individual dam removals and is not practically available given current dam removal rates. More than half of dams impound drainage areas less than 1 km2, and play little role in downstream sediment supply. In modeling of a simulated dam removal, suspended sediment in the estuary increases modestly near the source during discharge events, but otherwise effects on suspended sediment are minimal. Fine-grained sediment deposits broadly along the estuary and coarser sediment deposits near the source, with transport distance inversely related to settling velocity. | non-battery |
Epidural spinal cord electrical stimulation (ESCS) has been used as a means to facilitate locomotor recovery in spinal cord injured humans. Electrode arrays, instead of conventional pairs of electrodes, are necessary to investigate the effect of ESCS at different sites. These usually require a large number of implanted wires, which could lead to infections. This paper presents the design, fabrication and evaluation of a novel flexible active array for ESCS in rats. Three small (1.7 mm2) and thin (100 μm) application specific integrated circuits (ASICs) are embedded in the polydimethylsiloxane-based implant. This arrangement limits the number of communication tracks to three, while ensuring maximum testing versatility by providing independent access to all 12 electrodes in any configuration. Laser-patterned platinum-iridium foil forms the implant’s conductive tracks and electrodes. Double rivet bonds were employed for the dice microassembly. The active electrode array can deliver current pulses (up to 1 mA, 100 pulses per second) and supports interleaved stimulation with independent control of the stimulus parameters for each pulse. The stimulation timing and pulse duration are very versatile. The array was electrically characterized through impedance spectroscopy and voltage transient recordings. A prototype was tested for long term mechanical reliability when subjected to continuous bending. The results revealed no track or bond failure. To the best of the authors’ knowledge, this is the first time that flexible active electrode arrays with embedded electronics suitable for implantation inside the rat’s spinal canal have been proposed, developed and tested in vitro. | non-battery |
This paper is to present the implementation for maintenance of the 5kW a-Si GPV systems that were installed on the building-top of the Electrical Engineering Department at RMUTSB Nonthaburi, Thailand. The author had studied the way to maintain this system after operating for three years (2004–2006). The maintenance methods are classified into three parts. They are electrical, mechanical and component maintenance. Then the author used the maintenance check list for building-top GPV that author had developed. The period for planned maintenance was on July 2004, July 2005 and July 2006. The results are as follows: 1. The time for GPV shutdown system is 232h or 0.88% of system operating time. 2. The maintenance quantities are 17 times. They are 13 times for electrical maintenance and four times for component maintenance. 3. The time required for maintenance is 50h. Thirty-six hours for electrical maintenance and 14h for component maintenance. 4. The maintenance time (percent) used for the first year was 8%, second year was 20% and the last year was 72%. | battery |
The ionic conduction in a novel solid sodium-ion conductor of Na2Zn2TeO6 (NZTO) is investigated from the point of view of defect chemistry. NZTO shows an ionic conductivity of 0.57 mS cm−1 at room temperature, and the grain bulk conductivity and the grain-boundary conductivity are individually measured using the AC impedance spectroscopy at temperatures down to −30 °C. The grain-boundary conductivities are about two orders of magnitude lower than those of the grain bulk; such a phenomenon can be ascribed to the Schottky barrier at the grain boundaries of the NZTO electrolyte. The concentration and mobility of the charge carriers in the grain bulk are calculated from the grain bulk conductivity. The concentration and mobility of the charge carriers and the Schottky barrier height can be tuned by doping; the ionic conductivity of NZTO is enhanced to 0.83 mS cm−1 by the doping of 2.5 mol% Ga at the Zn sites, because the Ga-doping increases the concentration and mobility of the charge carriers, and lowers the Schottky barrier height. | battery |
Multi-walled carbon nanotube (MWNT) thin films have been fabricated by electrophoretic deposition technique in this study. The supercapacitors built from such thin film electrodes have exhibited near-ideal rectangular cyclic voltammograms even at a scan rate as high as 1000mVs−1 and a high specific power density over 20kWkg−1. More importantly, the supercapacitors showed superior frequency response, with a frequency ‘knee’ at about 7560Hz, which is more than 70 times higher than the highest ‘knee’ frequency (100Hz) so far reported for such supercapacitors. Our study also demonstrated that these carbon nanotube thin films can serve as a coating layer over ordinary current collectors to drastically enhance the electrode performance, indicating the huge potential in supercapacitor and battery manufacturing. Finally, it is clear that electrophoretic deposition is a promising technique for massive fabrication of carbon nanotube electrodes for various electronic devices. | battery |
This study aims at analyzing the response of Li-ion cells and at identifying the hazards and governing phenomena from hard to soft external short circuit conditions. 10 Ah pouch cells and 4.5 mAh coin cells were short circuited while synchronized current, potential and temperature signals, audio, IR and visual video recordings were registered. The anode, cathode and separator harvested from the cells were characterized by Scanning Electron Microscopy, micro X-ray Computed Tomography and 3D-profilometry. The complex short circuit behavior obtained can be described by 3 regions: In the first region 274C-rate is observed which is mainly governed by the cell's double and diffusion layer discharge. In the second region, the current drops significantly to 50–60C-rate where mass transport becomes the current limiting factor. The maximum temperature (77–121 °C) is reached and cell rupture, venting and electrolyte leakage may occur. In the final, third region the current decline continues due to the decaying electromotive force. The normalized external/internal resistance ratio is found to be the main influential factor on current and hazards rather than the external resistance or the capacity of the cell. The implications on the relevance and fitness-for-purpose of external short circuit test in standards are outlined. | battery |
Background Neurocognitive impairments are the strongest predictor of functional deficits in schizophrenia, but adaptive (i.e., functional) capacity, typically measured with performance-based assessments, yields an objective index of current abilities, whereas real-world functional performance relies on observations of community activity. However, limited experiences in the community may limit the acquisition, retention, or expression of these skills. Methods We examined the frequency of engagement in behaviors that are assessed in the current “gold standard” in person functional capacity assessment. The UCSD Performance-Based Skills Assessment (i.e., UPSA) examines skills associated with recreational engagement, handling money, scheduling appointments, and navigating public transportation. We used neurocognition, experience, and UPSA performance as predictors of the relationships among cognition and real-world functioning variables. Results Neurocognition was a significant correlate of UPSA scores regardless of whether it was forced into the model before or after prior experience, whereas experience was only a significant predictor of UPSA scores when entered before neurocognition. Further, functional capacity, neurocognition, and experience were significant predictors of real-world outcomes and experience remained a significant predictor regardless of the order it was entered into the model. Conclusions The amount of current experience with functional tasks is not a rate-limiter of the relationships between neurocognition and functional capacity but does account for some previously unexplained variance in the functional capacity–everyday functioning relationship. These findings underscore the importance of neurocognitive deficits as they relate to functional capacity in schizophrenia, and suggest an incremental functional cost of limited experience with independent living. | non-battery |
A number of pharmacological agents for treating negative symptoms in schizophrenia are currently in development. Unresolved questions regarding the design of clinical trials in this area were discussed at an international meeting in Florence, Italy in April 2012. Participants included representatives from academia, the pharmaceutical industry, and the European Medicines Agency (EMA). Prior to the meeting, participants submitted key questions for debate and discussion. Responses to the questions guided the discussion during the meeting. The group reached agreement on a number of issues: (1) study subjects should be under the age of 65; (2) subjects should be excluded for symptoms of depression that do not overlap with negative symptoms; (3) functional measures should not be required as a co-primary in negative symptom trials; (4) information from informants should be included for ratings when available; (5) Phase 2 negative symptom trials should be 12weeks and 26weeks is preferred for Phase 3 trials; (6) prior to entry into a negative symptom study, subjects should demonstrate clinical stability for a period of 4 to 6months by collection of retrospective information; and (7) prior to entry, the stability of negative and positive symptoms should be confirmed prospectively for four weeks or longer. The participants could not reach agreement on whether predominant or prominent negative symptoms should be required for study subjects. | non-battery |
Hearing impairment is the most common body system disability in veterans. In 2008, nearly 520,000 veterans had a disability for hearing loss through the Department of Veterans Affairs (VA). Changes in eligibility for hearing aid services, along with the aging population, contributed to a greater than 300% increase in the number of hearing aids dispensed from 1996 to 2006. In 2006, the VA committed to having no wait times for patient visits while providing quality clinically-appropriate care. One approach to achieving this goal is the use of group visits as an alternative to individual visits. We sought to determine: 1) if group hearing aid fitting and follow-up visits were at least as effective as individual visits, and 2) whether group visits lead to cost savings through the six month period after the hearing aid fitting. We describe the rationale, design, and characteristics of the baseline cohort of the first randomized clinical trial to study the impact of group versus individual hearing aid fitting and follow-up visits. | non-battery |
Different LiCoO2 thin films are prepared with radio-frequency (RF) sputtering technique. The physical and electrochemical properties of the films are characterized with X-ray diffraction (XRD), Raman scattering spectroscopy (RS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and charge–discharge experiments. The films obtained at high sputtering power such as 150W or 200W which are composed of bigger particles or larger pieces of the target material exhibit better electrochemical performance than the films obtained at low sputtering powers. It should avoid further annealing process of the thin film electrodes. The experimental results have explained why the as-deposited films become better crystallized and therefore their charge–discharge performance is further improved with the increase of the sputtering power. | battery |
While it has been hypothesized that brown adipocytes responsible for mammalian thermogenesis are absent in birds, the existence of beige fat has yet to be studied directly. The present study tests the hypothesis that beige fat emerges in birds as a mechanism of physiological adaptation to cold environments. Subcutaneous neck adipose tissue from cold-acclimated or triiodothyronine (T3)-treated chickens exhibited increases in the expression of avian uncoupling protein (avUCP, an ortholog of mammalian UCP2 and UCP3) gene and some known mammalian beige adipocyte-specific markers. Morphological characteristics of white adipose tissues of treated chickens showed increased numbers of both small and larger clusters of multilocular fat cells within the tissues. Increases in protein levels of avUCP and mitochondrial marker protein, voltage-dependent anion channel, and immunohistochemical analysis for subcutaneous neck fat revealed the presence of potentially thermogenic mitochondria-rich cells. This is the first evidence that the capacity for thermogenesis may be acquired by differentiating adipose tissue into beige-like fat for maintaining temperature homeostasis in the subcutaneous fat ‘neck warmer’ in chickens exposed to a cold environment.
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Although Δ9-tetrahydrocannabinol (THC) and other mixed CB1/CB2 receptor agonists are well established to elicit antinociceptive effects, their psychomimetic actions and potential for abuse have dampened enthusiasm for their therapeutic development. Conversely, CB2 receptor-selective agonists have been shown to reduce pain and inflammation, without eliciting apparent cannabinoid behavioral effects. In the present study, we developed a novel ethyl sulfonamide THC analog, O-3223, and compared its pharmacological effects to those of the potent, mixed CB1/CB2 receptor agonist, CP55,940, in a battery of preclinical pain models. Competitive cannabinoid receptor binding experiments revealed that O-3223 was approximately 80-fold more selective for CB2 than CB1 receptors. Additionally, O-3223 behaved as a full CB2 receptor agonist in [35S]GTPγS binding. O-3223 reduced nociceptive behavior in both phases of the formalin test, reduced thermal hyperalgesia in the chronic constriction injury of the sciatic nerve (CCI) model, and reduced edema and thermal hyperalgesia elicited by intraplantar injection of LPS. These effects were blocked by pretreatment with the CB2 receptor-selective antagonist SR144528, but not by the CB1 receptor antagonist, rimonabant. Unlike CP55,940, O-3223 did not elicit acute antinociceptive effects in the hot-plate test, hypothermia, or motor disturbances, as assessed in the rotarod test. These data indicate that the CB2 receptor-selective agonist, O-3223, reduces inflammatory and neuropathic nociception, without affecting basal nociception or eliciting overt behavioral effects. Moreover, this compound can serve as a template to develop new CB2 receptor agonists with increased receptor selectivity and increased potency in treating inflammatory and neuropathic pain. | non-battery |
Generally, routing algorithms for opportunistic networks rely on the fact that nodes are willing to accept data from other nodes under any circumstances, but this is not the case. Selfish nodes might not want to participate in the routing process for various reasons, such as low resources (e.g. battery, memory, CPU, and network bandwidth), fear of malicious data from unknown users, or even lack of interest in helping nodes from other communities. Therefore, these types of nodes should be detected and avoided in the routing process. Moreover, incentive mechanisms that reward nodes when they actively take part in the network and punish them when they do not, should be employed where possible. In this paper, we propose SENSE, a novel social-based collaborative content and context-based selfish node detection algorithm with an incentive mechanism, which aims to reduce the issues of having selfish nodes in an opportunistic network. Since local information may not be sufficient to reach an informed decision, nodes running SENSE collaborate through gossiping, for the final goal of detecting selfish nodes, punishing and avoiding them. We compare our approach to an existing algorithm (IRONMAN) and show that it behaves better in terms of network performance and detection accuracy. Moreover, we show that SENSE behaves well even when we simulate the existence of devices with batteries that get depleted, thus rendering them inactive for given time periods. | non-battery |
As a promising anode material alternative to the carbons, Li4Ti5O12 has drawn wide attention for its overwhelming advantages in meeting requirements of lithium ion batteries with high power density, long cycling life and safety for electric vehicles and electricity storage stations. Its stability issue during storage is interesting and of large importance. In this work, the stability of commercial spinel Li4Ti5O12 material in air has been characterized by a series of physical and electrochemical techniques. First-principles calculations indicate that Li4Ti5O12 is lithium-truncated at the surface. This explains why it tends to absorb H2O and CO2 to form Li2CO3 but the formation of Li2CO3 does not significantly impact its electrochemical performances. | battery |
There is a substantial amount of public concern about patient safety, as, according to estimates from major studies, hundreds of thousands die in hospitals each year all over the developed world as a result of medical errors that could have been prevented. Unprecedented research commissioned by the EU has found that almost one out of every four families has experienced a serious medical error. Greek citizens concerning about serious medical errors in the hospital environment, were at the top of the list. Greek Ombudsman's report on medical errors has raised the debate among health policy makers as to the appropriate response to the problem. Proposals range from the implementation of nationwide mandatory reporting with public release of performance data, to voluntary reporting and quality-assurance efforts that protect the confidentiality of error-related data. Any successful safety program will first require a national effort to make significant investments in information systems, along with providing an environment and education that enables to contribute to an active quality improvement process. In this paper we propose the development and implementation of Medical Error Reporting Information System (MERIS), in order to identify, collect, analyse and report medical errors and patient adverse events, as a tool for enhancing patient safety and health care quality. We also describe the necessary organisational structure and the infrastructure environment of the system and the barriers to its successful implementation. | non-battery |
Subjective ratings of fatigue are increasingly being used as part of a suite of tools to assess fatigue-related risk on the road and in the workplace. There is some debate however, as to whether individuals can accurately gauge their own fatigue states, particularly under conditions of sleep restriction. It is also unclear which references are used by individuals to assess fatigue – for example prior sleep, time of day, workload, or previous ratings. The current study used a sophisticated laboratory protocol to examine the independent contributions of sleep, circadian phase and sleep debt to fatigue ratings. Importantly, participants had no knowledge of time of day, how much sleep they were getting, or how long they were awake. Twenty-eight healthy, young males participated in one of two conditions of a 28h forced desynchrony protocol – severe sleep restriction (4.7h sleep and 23.3h wake) or moderate sleep restriction (7h sleep and 21h wake). Fatigue ratings were provided prior to and following each sleep period using the Samn–Perelli fatigue scale. Repeated measures ANOVAs were used to analyse the effects of circadian phase, sleep dose and study day. Results demonstrated an effect of circadian phase on both pre-sleep and post-sleep fatigue ratings. The significant effect of study day is interpreted as an effect of circadian time, as opposed to accumulating sleep debt. An effect of sleep dose was only seen in post-sleep fatigue ratings. The findings suggest that post-sleep fatigue ratings may be sensitive to prior sleep and may be useful as an indicator of fatigue-related risk, particularly when triangulated with information about recent total sleep time. | non-battery |
The use of carbide-derived carbon (CDC) as the positive electrode material for lithium-ion capacitors (LICs) is investigated. CDC based LIC cells are studied utilizing two different negative electrode materials: graphite and lithium titanate Li4Ti5O12 (LTO). The graphite electrodes are prelithiated before assembling the LICs, and LTO containing cells are studied with and without prelithiation. The rate capability and cycle life stability during 1000 cycles are evaluated by galvanostatic cycling at current densities of 0.4–4 mA cm−2. The CDC shows a specific capacitance of 120 F g−1 in the organic lithium-containing electrolyte, and the LICs demonstrate a good stability over 1000 charge-discharge cycles. The choice of the negative electrode is found to have an effect on the utilization of the CDC positive electrode during cycling and on the specific energy of the device. The graphite/CDC cell delivers a maximum specific discharge energy of 90 Wh kg−1 based on the total mass of active material in the cell. Both the prelithiated and non-prelithiated LTO/CDC cells show a specific energy of around 30 Wh kg−1. | battery |
The rate-determining step in electrochemical oxidation reaction of Li metal at the interface between an Li negative electrode and xLi2S–(100−x)P2S5 (x = 75, 70 or 67) solid electrolyte was determined on the basis of the study on Ag+ ion conductive solid electrolytes. For this purpose, potential step technique using a microelectrode was applied. Two possible rate-determining steps, the diffusion of Li+ ion vacancies and the reaction between interstitial Li+ ions and Li+ ion vacancies, were assumed, and we found the diffusion of Li+ ion vacancies is the rate-determining step in the present study. We also evaluated the exchange current density (i 0) of the Li/Li+ couple reaction and ionic conductivity (κ) of each solid electrolyte. Both i 0 and κ were increased as the x value was increased, suggesting that the conductivity of Li+ ions or the rate of the diffusion of Li+ ion vacancies was closely related to the rate of the Li/Li+ couple reaction. | battery |
A combined modelling-experiments approach is presented with the aim of determining in-situ key characteristics of a RFB. The porous electrode impedance was calculated and measured without and with a faradaic reaction, by means of a symmetric cell. The technique was applied to the specific [Fe(CN)6]3-/[Fe(CN)6]4- couple whose interest for RFB application is substantial. The interpretation of Electrochemical Impedance Spectroscopy (EIS) data enabled the determination of the key membrane and electrode resistances and the investigation of their evolutions during the battery operation. The effects of the cation composition in the supporting electrolyte, the carbon material and the cycling were analysed. The results gave insights on degradation mechanisms that can hinder RFB performance, and delineated the phenomena occurring during electrolyte circulation or during battery operation. | battery |
Although prey capture by cnidarians is mediated through nematocysts, their influence on prey selection by cnidarians remains poorly documented. The difficulty in visualizing nematocyst–prey interactions remains the chief obstacle to understanding how the wide variety of nematocyst types influences the mechanics of prey capture. One solution to this limitation has been to assign functional roles to nematocysts based on morphological characters of discharged cnidae. Here we report results of an alternative approach based upon dynamic traits of nematocyst discharge. We examined tubule lengths, tubule discharge velocities and net-to-gross displacement ratios of tubules of discharging nematocysts possessed by the cosmopolitan scyphomedusa, Cyanea capillata. This nematocyst assemblage consisted of euryteles, birhopaloids and three different isorhizas — a-isorhizas, A-isorhizas and O-isorhizas. Dynamic traits varied little within each nematocyst type but there were significant differences between the different types. Most importantly, dynamic traits varied significantly within a broad category of nematocyst – the isorhizas – indicating that conventional classification schemes that infer function based on broad nematocyst categories may not appropriately describe the functional roles of these nematocysts. The dynamic properties of discharging nematocysts were consistent with physical results described in studies using scanning electron microscopy images of nematocyst–prey interactions. These data suggest that nematocysts vary significantly in their roles during predation, but that inferences relating prey selection with broad nematocyst categories merit careful examination. | non-battery |
Low Co AB5-type MmNi3.8Co0.4Mn0.6Al0.2B x (x=0, 0.1, 0.2, 0.3, 0.4) hydrogen storage alloys were prepared by cast and rapid quenching. The microstructures and electrochemical performances of the as-cast and quenched alloys were analysed and measured. The effects of boron additive and rapid quenching technique on the microstructures and electrochemical properties of as-cast and quenched alloys were investigated comprehensively. The experimental results showed that the microstructure of as-cast MmNi3.8Co0.4Mn0.6Al0.2B x (x=0, 0.1, 0.2, 0.3, 0.4) alloys was composed of CaCu5-type main phase and a small amount of CeCo4B-type secondary phase. The abundance of the secondary phase increases with the increase of boron context x. The rapid quenching techniques were used in the preparation of the alloys. The amount of secondary phase in the alloys decreased with the increase of quenching rate. Rapid quenching made lattice constants increase slightly. The effects of rapid quenching on the electrochemical performances of the alloys are very significant. The discharge capacity of the alloys decreased obviously and the cycle stability increased dramatically with the increase of quenching rate. Rapid quenching made the activation capability of the alloys lowered. However, the activate performance and high rate discharge capability as well as discharge voltage characteristic of the alloys were modified obviously with the increase of boron content x. | battery |
Personality traits are related with risk of hazardous alcohol use and alcohol dependence. The Substance Use Risk Profile Scale (SURPS) measures personality traits associated with addictive substance abuse. We examined psychometric properties of the SURPS in Lithuanian population. | non-battery |
The advanced technology of computing system was followed by the rapid improvement of medical instrumentation and patient record management system. The typical examples are hospital information system (HIS) and picture archiving and communication system (PACS), which computerized the management procedure of medical records and images in hospital. Because these systems were built and used in hospitals, doctors out of hospital have problems to access them immediately on emergent cases. To solve these problems, this paper addressed the realization of system that could transmit the images acquired by medical imaging systems in hospital to the remote doctors’ handheld PDA’s using CDMA cellular phone network. The system consists of server and PDA. The server was developed to manage the accounts of doctors and patients and allocate the patient images to each doctor. The PDA was developed to display patient images through remote server connection. To authenticate the personal user, remote data access (RDA) method was used in PDA accessing the server database and file transfer protocol (FTP) was used to download patient images from the remove server. In laboratory experiments, it was calculated to take ninety seconds to transmit thirty images with 832 × 488 resolution and 24 bit depth and 0.37 Mb size. This result showed that the developed system has no problems for remote doctors to receive and review the patient images immediately on emergent cases. | non-battery |
Single-chamber solid oxide fuel cells (SC-SOFCs) incorporating thin-film Sm0.15Ce0.85O1.925 (SDC) as the electrolyte, thick Ni+SDC as the (supporting) anode and SDC+BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3−δ ) as the cathode were operated in a mixture of methane, oxygen and helium at furnace temperatures of 500–650°C. Because of the exothermic nature of the oxidation reactions that occur at the anode, the cell temperature was as much as 150°C greater than the furnace temperature. Overall, the open circuit voltage was only slightly sensitive to temperature and gas composition, varying from ∼0.70 to ∼0.78V over the range of conditions explored. In contrast, the power density strongly increased with temperature and broadly peaked at a methane to oxygen ratio of ∼1:1. At a furnace temperature of 650°C (cell temperature ∼790°C), a peak power density of 760mWcm−2 was attained using a mixed gas with methane, oxygen and helium flow rates of 87, 80 and 320mLmin−1 [STP], respectively. This level of power output is the highest reported in the literature for single chamber fuel cells and reflects the exceptionally high activity of the BSCF cathode for oxygen electro-reduction and its low activity for methane oxidation. | battery |
A critical issue to boost the development of sodium ion batteries is the development of advanced active materials via meticulous understanding of the synthesis process. The practical application of sodium vanadium phosphate (Na3V2(PO4)3), which shows high energy density, stable structure and excellent thermal properties, is hindered by the intrinsic poor electronic conductivity. Carbon coating was proved to be an effective strategy to cover such pristine limitation and deserved systematic and intensive investigation. Herein, saccharides that widely distributed in nature with different molecular weights were selected to identify the function mechanism of carbon sources in preparing Na3V2(PO4)3@C composite via solid state reaction. Comprehensive and systematic results evidenced that the high polymer starch with glucose polymerization could construct three-dimensional interconnected carbon network, which would boost the electron conductivity and stabilize the structure upon repeated sodium ions insertion/extraction. As a consequence, the extraordinary high rate capability and long-time stability were obtained: a high rate capacity of 72 mA h g−1 could be delivered even at 40 C and the cell retained a capacity retention of 82.8% after 1000 cycles at 1 C. We believe that our work presents here would provide important insights into the carbon coating strategy, which will be favourable for accelerating the commercialization of SIBs. | battery |
A novel precious metal-free electrode catalyst SnO2/m-ZSM-5 nanocomposite has been successfully synthesized. This SnO2/m-ZSM-5 nanocomposite shows high and stable electrochemical catalytic activity for methanol oxidation, which is comparable to Pt/C. The high electrochemical performance has been attributed to the synergetic catalytic effects between the mesoporous ZSM-5 matrix and the loaded SnO2 nanocrystals.
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Harvesting energy from ambient vibration sources with ultrathin flexible piezoelectric energy harvesters (PEHs) for battery-free electronics has received attention in recent years. However, the excitation modes in the environment and human body motion are more complicated than the ideal harmonic modes employed in previous theoretical analyses, and their influence on the efficiency of PEHs has received little attention. In this study, these environmental excitation modes are classified into three types, i.e., the triangular, sinusoidal, and square wave modes, with varied duty ratios. We derived theoretically the output power of flexible PEHs under these excitation modes and establish a simple scaling law, in which the normalized output power depends only on two combined normalized parameters, i.e., the intrinsic system parameter and the excitation mode. Results reveal that the output power of PEHs changes dramatically for different excitation modes with varied duty ratios even when all the other parameters including excitation amplitude, excitation frequency, electrical parameter, and geometrical and material parameters of the PEHs are identical. This paper may provide a systematic understanding in the effect of excitation modes on the output power of flexible PEHs and promote the realization of energy harvesting from the complex environmental and human body motions.
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Traditional sodium-ion battery cathodes utilize the change in oxidation state of the transition metal(s) in the structure to accommodate the electron transfer during charge and discharge. Recent researches on sodium-rich compounds such as Na2RuO3 and Na2IrO3 suggest that anionic reaction with oxygen can be an additional source of electrons during electrochemical reactions. Here we demonstrate for the first time that stoichiometric NaVO3, despite the valence of vanadium of 5+, delivers a reversible capacity by activating it beyond 4.5 V. Elemental analysis confirms Na removal and insertion from/into NaVO3 during charge/discharge. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy results show that the oxidation state of vanadium remains unchanged, while oxygen is likely to compensate for the charge transfer during charge/discharge. Theoretical calculation on spin density of electrons in the lattice also supports the involvement of oxygen during sodium removal. Our demonstration of the unique behaviors of NaVO3 provides a new exciting direction for research in sodium-ion battery cathodes. | battery |
School underachievement means a certain quantity of human resource which is taken out of educational circuit. The purpose of study is to investigate this phenomenon at the high school students age in order to identify personality correlates according to age, gender and type of high school they attend (sciences or humanities). We tested 120 students from four classes, two of sciences and two of humanities, from two high schools in Brasov. Predominance of verbalism in education leads to an insufficient valorization of boys. Excitement-seeking, need for actions, role of peers are significantly limited by Romanian education. The progressive character of school underachievement imposes measure of structural change to increase the opportunity of students’ school adjustment. | non-battery |
Mathematical modeling and simulation methods are important tools in studying various processes in science and engineering. In the current review, we focus on the applications of hybrid models (HMs) in chemical processes, oil and gas processes, and applied energy systems. These processes suffer from complexities that demand advanced mathematical tools to be employed for various purposes such as process development, identification, simulation and modeling, optimization, control, classification, clustering, forecasting, and monitoring. Beside the lack of adequate knowledge about the processes related to the chemical and energy systems, there are other mathematical complexities such as non-linearity, large and multi-scale, long dynamics, uncertainties, and high dimensionality. The HMs can provide a practical solution to such complex processes. The arrangements of different black-box models with themselves or with white-box models are alternatively used to reduce the model complexities. The hybrid gray-box models are of significant importance as they combine the physical significance and generalization capabilities of the white-box models with the complexity reduction capability of the black-box models to facilitate/enhance the modeling strategy, while a desired precision is targeted. Such a hybridized model enables the physically-meaningful computation for the time-demanding applications. In this paper, we review different sub-models, hybridization strategies, structural designs, screening criteria, and new directions in hybrid modeling, with focus on the corresponding applications in chemical, petroleum, and energy systems. | battery |
Results of theoretical and experimental studies of corrosion processes of graphite in vanadium electrolytes and methods for corrosion prevention are presented. Electric contact of positive half-cell electrolyte in the inlet/outlet channels of vanadium redox flow batteries (VRFB) with graphite collectors generates parasitic electric currents, which cause electrochemical oxidation of carbon atoms on the surface of the collectors. This leads to damaging the collectors and flow battery failure. The parasitic currents in the electrolyte channels were calculated and measured. Methods to prevent the corrosion, caused by the parasitic currents, were investigated: the graphite planar collectors were electrically isolated from electrolyte in inlet/outlet channels by o-rings and in inlet/outlet area of half-cell by isolation films. A corrosion resistant battery with collectors, fabricated from pyrolytic graphite, was constructed. | battery |
Cyclic voltammograms, current transients at constant potential and potential decay transients have been used to study the formation of lead dioxide surface films in the presence of cobalt ions and their role in decreasing the oxidation rate of a lead alloy under steady state conditions typical of copper electrowinning. The observations in the present work indicate, consistent with the surface film model, that the formation of a continuous PbSO4 + α-PbO2 film on the surface of the lead alloy in the presence of cobalt ions hinders further oxidation of the metal. The protectiveness of the film is dynamic in the steady state; the film is continuously forming and dissolving. Also studied was the potential of the oxygen evolution reaction on α-PbO2 and β-PbO2 in 170 g L−1 H2SO4 with and without cobalt ions. The steady state potential for oxygen evolution on β-PbO2 in 170 g L−1 H2SO4 at 285 A m−2 decreased in the presence of cobalt ions and the steady state potential of β-PbO2 was essentially the same as that of (i) the Pb–Ca–Sn alloy and (ii) α-PbO2. The implication is that the potential of the Pb–Ca–Sn alloy is determined by the α-PbO2 and/or β-PbO2 on its surface. | battery |
Core–shell nanocatalysts have demonstrated potential as highly active low-Pt fuel cell cathodes for the oxygen reduction reaction (ORR); however, challenges remain in optimizing their surface and interfacial structures, which often exhibit undesirable structural degradation and poor durability. Here, we construct an unsupported nanoporous catalyst with a Pt–Pd shell of sub-nanometre thickness on Au, which demonstrates an initial ORR activity of 1.140 A mgPt−1 at 0.9 V. The activity increases to 1.471 A mgPt−1 after 30,000 potential cycles and is stable over a further 70,000 cycles. Using aberration-corrected scanning transmission electron microscopy and atomically resolved elemental mapping, the origin of the activity change is revealed to be an atomic-scale evolution of the shell from an initial Pt–Pd alloy into a bilayer structure with a Pt-rich trimetallic surface, and finally into a uniform and stable Pt–Pd–Au alloy. This Pt–Pd–Au alloy possesses a suitable configuration for ORR, giving a relatively low free energy change for the final water formation from adsorbed OH intermediate during the reaction. | battery |
Lead dioxide electrodes with three-dimensional porous titanium as substrate (3D-Ti/PbO2) were prepared by galvanostatic electrodeposition. The structure, morphology and electrochemical performances of 3D-Ti/PbO2 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammetry and galvanostatic charge-discharge techniques. The electrochemical performances of 3D-Ti/PbO2 were optimized by adjusting the applied deposition current density. Results reveal that the 3D-Ti/PbO2 prepared at 1mAcm−2 had nanoparticles on its surface with abundant crystal orientations. It had a high capacity of 132 mAh g−1 with an active material utilization of 57% at discharge current density of 0.9 A g−1. With the same condition, the lead dioxide electrode with planar titanium substrate (Ti/PbO2) only had a capacity of 20.8 mAh g−1. The high electrochemical active surface area and small charge transfer resistance resulted in the high capacity of 3D-Ti/PbO2. The possible factors, which affected the electrochemical performances of 3D-Ti/PbO2, were interpreted in detail with voltammetric charge analysis and electrochemical impedance spectroscopy. | battery |
We have developed an efficient method to generate highly active Pd nanoparticles supported on graphene (Pd/G) by microwave-assisted chemical reduction of the corresponding aqueous mixture of a palladium salt and dispersed graphite oxide (GO) sheets. The Pd/G demonstrated excellent catalytic activity for the carbon–carbon cross-coupling reactions (Suzuki, and Heck) with a broad range of utility under ligand-free ambient conditions in an environmentally friendly solvent system. It also offers a remarkable turnover frequency (108,000h−1) observed in the microwave-assisted Suzuki cross-coupling reactions with easy removal from the reaction mixture, recyclability with no loss of activity, and significantly better performance than the well-known commercial Pd/C catalyst. The catalyst was fully characterized by a variety of spectroscopic techniques including X-ray diffraction (XRD), Raman, TGA, electron microscopy (SEM, TEM), and X-ray photoelectron spectroscopy (XPS). The remarkable reactivity of the Pd/G catalyst toward Suzuki cross-coupling reactions is attributed to the high degree of the dispersion and concentration of Pd(0) nanoparticles supported on graphene sheets with small particle size of 7–9nm due to an efficient microwave-assisted reduction method. | non-battery |
We explore the operations, balancing requirements, and costs of the Western Electricity Coordinating Council power system under a stringent greenhouse gas emission reduction target. We include sensitivities for technology costs and availability, fuel prices and emissions, and demand profile. Meeting an emissions target of 85% below 1990 levels is feasible across a range of assumptions, but the cost of achieving the goal and the technology mix are uncertain. Deployment of solar photovoltaics is the main driver of storage deployment: the diurnal periodicity of solar energy availability results in opportunities for daily arbitrage that storage technologies with several hours of duration are well suited to provide. Wind output exhibits seasonal variations and requires storage with a large energy subcomponent to avoid curtailment. The combination of low-cost solar technology and advanced battery technology can provide substantial savings through 2050, greatly mitigating the cost of climate change mitigation. Policy goals for storage deployment should be based on the function storage will play on the grid and therefore incorporate both the power rating and duration of the storage system. These goals should be set as part of overall portfolio development, as system flexibility needs will vary with the grid mix. | battery |
Functional nanofibrous polymer membranes were prepared by incorporating poly(2-aminothio phenol) (P2AT) stabilized Au NPs onto electrospun polyvinylidene fluoride (PVdF) nanofibers (designated as P2AT-Au NPs@PVdF-NFM). The preparation of P2AT-Au NPs@PVdF-NFM involves two steps: loading of 2AT (monomer) into electrospun PVdF nanofibrous membrane and polymerization of 2AT by gold chloride. P2AT and Au NPs were simultaneously formed into the electrospun PVdF-NFM. Transmission electron microscope image of P2AT-Au NPs@PVdF-NFM informs the presence of Au NPs (with sizes ~10 nm) onto PVdF-NFM. | non-battery |
Genomic and proteomic analysis are potent tools for metabolic characterization of microorganisms. Although cellulose usually triggers cellulase production in cellulolytic fungi, the secretion of the different enzymes involved in polymer conversion is subjected to different factors, depending on growth conditions. These enzymes are key factors in biomass exploitation for second generation bioethanol production. Although highly effective commercial cocktails are available, they are usually deficient for β-glucosidase activity, and genera like Penicillium and Talaromyces are being explored for its production. | non-battery |
The effect of water contamination in the electrolyte on the performance of AC/graphite capacitor has been investigated by electrochemical tests and in situ XRD measurements. The deterioration mechanisms for the charge storage ability of the electrodes in the capacitors using polluted electrolytes have also been addressed. | battery |
Limitations of standard clinical pressure transducers have hampered our ability to provide reliable measurements of intra-abdominal pressure (IAP) during physical activities. To overcome these limitations, a novel intravaginal transducer (IVT) capable of accurate, reliable, and continuous IAP measurements during normal activity was developed. The design was validated through comparison with standard clinical pressure transducers in both bench top and clinical tests. The IVT demonstrated an improved dynamic response when compared to a standard rectal balloon catheter. Additionally, the radially symmetric design allows for accurate measurement within non-fluid-filled tissue cavities and simple placement within the vaginal canal. This is an advantage over sensor-tipped transducers which are only reliable in fluid-filled compartments. The IVT design presented here is preliminary to a wireless version that will allow for IAP measurement during activities outside the clinic. | non-battery |
LiCoO2 is synthesized via a hydrothermal reaction of cobalt salt, LiOH·H2O and suitable amount of H2O2. A series of LiCoO2 + x% S mixtures are prepared by simply mixing LiCoO2 and S powder with different LiCoO2/S weight ratios, and investigated as anode material for alkaline secondary battery. At the discharge current density of 500mAg−1, LiCoO2 +5% S mixture electrode displays the maximum discharge capacity of 320mAhg−1. Meanwhile, the LiCoO2 +10% S mixture electrode shows the most outstanding cycle performance with a capacity retention rate of over 94% after 150th charge–discharge cycles. Moreover, the charge–discharge reaction mechanism of LiCoO2 + x% S mixture electrodes is also investigated. | battery |
Developing fast-charging protocols for Li-ion batteries is a key issue for a wider deployment of electric vehicles and portable electrical devices. In this study, fast-charging of lithium iron phosphate batteries is investigated with different protocols. High charging rates are used with an extended constant current period thanks to a higher limit voltage based on the ohmic-drop compensation principle. This study shows that a compromise has to be found between the charging time and the durability of the battery. As an example a 6C charge with 57% ohmic-drop compensation allows to reach 95% of charge in 11min and the full charge in half an hour. With this protocol, more than 1500 cycles are reached before getting below 80% of state of health. | battery |
With the rapid surge of renewable energy integrations into the electrical grid, the main questions remain; how do we manage and operate optimally these surges of fluctuating resources? However, vast optimization approaches in renewable energy applications have been widely used hitherto to aid decision-makings in mitigating the limitations of computations. This paper comprehensively reviews the generic steps of stochastic optimizations in renewable energy applications, from the modelling of the uncertainties and sampling of relevant information, respectively. Furthermore, the benefits and drawbacks of the stochastic optimization methods are highlighted. Moreover, notable optimization methods pertaining to the steps of stochastic optimizations are highlighted. The aim of the paper is to introduce the recent advancements and notable stochastic methods and trending of the methods going into the future of renewable energy applications. Relevant future research areas are identified to support the transition of stochastic optimizations from the traditional deterministic approaches. We concluded based on the surveyed literatures that the stochastic optimization methods almost always outperform the deterministic optimization methods in terms of social, technical, and economic aspects of renewable energy systems. Thus, this review will catalyse the effort in advancing the research of stochastic optimization methods within the scopes of renewable energy applications. | battery |
Lithium-Sulfur (Li-S) battery technology is one of the promising candidates for next generation energy storage systems. Many studies have focused on the cathode materials to improve the cell performance. In this work we present a series of poly (S-DVB) copolymers synthesised by inverse vulcanization of sulfur with divinylbenzene (DVB). The poly (S-DVB) cathode shows excellent cycling performances at C/2 and C/4 current rates, respectively. It was demonstrated poly (S-DVB) copolymer containing 20% DVB did not influence the electrochemical performance of the sulfur material, compared to elemental sulfur as high specific capacities over ∼700 mAh g−1 at 500 cycles were achieved at C/4 current rate, comparable to conventional carbon-based S cathodes. However, the use of copolymer network is assumed to act firstly as sulfur reservoir and secondly as mechanical stabilizer, enhancing significantly the cycling lifetime. The Li-poly (S-DVB) cell demonstrated an extremely low degradation rate of 0.04% per cycle achieving over 1600 cycles at C/2 current rate. | battery |
This research explores the recovery of metals from spent Zn–Mn or Ni–Cd batteries by a bioleaching using six Aspergillus species. Two different nutrients, malt extract and sucrose, were used to produce different types of organic acids. Oxalic acid and citric acid were shown to be the dominant organic acid in malt extract and sucrose media, respectively. In the bioleaching, the metal removal was higher in sucrose media than malt extract. All species, except A. niger KUC5254, showed more than 90% removal of metals from Zn–Mn battery. For Ni–Cd battery, more than 95% of metals was extracted by A. niger KUC5254 and A. tubingensis KUC5037. As a result, A. tubingensis KUC5037 which is a non-ochratoxigenic fungus was considered to have the greatest potential for improving the safety and efficiency of the bioleaching. | non-battery |
Nanoflake nickel hydroxide and reduced graphene oxide composite (Ni(OH)2/rGO) has been prepared by a facile method of homogenous coprecipitation and subsequent reduction. The measurement results demonstrate that Ni(OH)2/rGO as an anode material for lithium ion batteries has 1500 and 1110mAhg−1 for the first discharge and charge capacities, respectively, as well as 1003mAhg−1 after 40 cycles. The Ni(OH)2/rGO composite is a promising candidate for high capacity lithium ion batteries. | battery |
Information on health status, risk factors, health insurance, and health-care utilization is used to plan, conduct, and evaluate public health programs, to inform policies, regulations, and legislation, and to conduct research to better understand the determinants and consequences of health and health care. Health is a social as well as a biologic concept, and health surveys address all aspects of health and health care. Major topics covered include the conceptualization and measurement of health status and the determinants of health, summary measures of health, health-care utilization, and health behaviors. Survey design issues discussed include sampling, data linkage, data quality, and the protection of privacy and confidentiality. | non-battery |
Retinoic acid mediates most of the biological actions of vitamin A. It is oxidized by CYP26A1 to 4-oxoretinoic acid, considered as an inactive catabolite of retinoic acid. However, in the light of studies reporting the presence of 4-oxoretinal or 4-oxoretinol as the predominant retinoids during morphogenesis, we analyzed the retinoid-like biological activity of these oxoretinoids in mouse skin in vivo. Topical 4-oxoretinal and 4-oxoretinol promoted significant epidermal hyperplasia and metaplasia in mouse tail. They induced a moderate response for epidermal inflammation, compared with retinal, whereas neither 4-oxoretinal nor 4-oxoretinol prevented menadione-induced epidermal lipid peroxidation, unlike retinal and retinol. As analyzed by quantitative PCR, 4-oxoretinal and 4-oxoretinol did not reproduce the significant increased expression of genes coding for keratin 4, amphiregulin, heparin-EGF and CYP26A1, that did induce retinal and retinol. However, both retinal and 4-oxoretinal significantly inhibited the lipopolysaccharide-induced maturation of human dendritic cells in vitro. As analyzed in vivo and in vitro, 4-oxoretinal and 4-oxoretinol were not converted into retinoic acid. We conclude that 4-oxoretinal and 4-oxoretinol exert a moderate direct retinoid-like activity in vivo, thus confirming previous in vitro studies in amphibians showing 4-oxometabolites of vitamin A as bioactive agents rather than inactive catabolites. | non-battery |
Zn-air batteries, which are cost-effective and have high energy density, are promising energy storage devices for renewable energy and power sources for electric transportation. Nevertheless, limited charge and discharge cycles and low round-trip efficiency have long been barriers preventing the large-scale deployment of Zn-air batteries in the marketplace. Technology advancements for each battery component and the whole battery/cell assembly are being pursued, with some key milestones reached during the past 20 years. As an example, commercial Zn-air battery products with long lifetimes and high energy efficiencies are being considered for grid-scale energy storage and for automotive markets. In this review, we present our perspectives on improvements in Zn-air battery technology through the exploration and utilization of different electrolyte systems. Recent studies ranging from aqueous electrolytes to nonaqueous electrolytes, including solid polymer electrolytes and ionic liquids, as well as hybrid electrolyte systems adopted in Zn-air batteries have been evaluated. Understanding the benefits and drawbacks of each electrolyte, as well as the fundamental electrochemistry of Zn and air electrodes in different electrolytes, are the focus of this paper. Further consideration is given to detailed Zn-air battery configurations that have been studied and applied in commercial or nearing commercial products, with the purpose of exposing state-of-the-art technology innovations and providing insights into future advancements. | battery |
Smart home systems are designed as platforms for connecting sensors, home appliances, and devices to exchange data and, ultimately, to provide useful services to home residents. However, such systems are vulnerable to Cybersecurity attacks that can affect the reliability and integrity of the delivered services. Sensors, planted at smart homes or equipped with smart appliances, are highly exposed to identity theft. Intruders can recognize through the understanding of the exchanged data, their locations, or knowing their associated services. Such information might make the home resident vulnerable to life attacks. Therefore, protecting sensors identities in smart home systems is of high interest in this domain. This paper introduces a novel technique that protects sensors’ identity from being recognized through cordless communication environments. Our proposed approach utilizes a three-phase technique that controls a synchronized queue among connected sensors and keeps their identity hidden from outsiders. The proposed approach preserves the linearity of time that is required to manage the protection of the home network. To validate the performance of our proposed approach, we conducted experiments on four different smart homes datasets. Furthermore, we performed a sensitivity analysis to measure how our proposed approach is affected by different environmental variables. The results indicated that the proposed approach provides a significant performance in protecting sensors identities in smart home area networks. Furthermore, during the sensitivity analysis, we found that our proposed technique’s performance is highly affected by the threshold value that defines each sensor’s time interval.
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Due to its weight and toxicity, Pb is usually not considered as possible anode for Li- and Na-ion (NIBs) batteries. Nevertheless the toxicity is related to specific applications and its recycling is more than 99% which is one of the highest recycling rates on the planet where no other power source is utilized in more applications with such sustainability. For this reason, we have investigated micrometric lead particles as electrode for NIBs in an ether-based electrolyte (1 M NaPF6 in diglyme). The cyclability, coulombic efficiency and rate capability of lead were unexpected. A high loaded lead electrode with 98%wt of Pb and only 1% of carbon additive showed i) a capacity retention of 464 mA h/g after 50 cycles with only 1.5% of capacity loss, which represents a high volumetric capacity of 5289 mA h/cm3 due to the high density of Pb and ii) a very interesting capacity retention even at high current rate (1950 mA/g). In situ XRD study confirmed a sodiation–desodiation process in four steps. Preliminary tests in Pb//Na3V2(PO4)2F3 full cells showed promising results demonstrating that Pb could be a practical candidate for future high energy density Na-ion batteries with an efficient sodiated or non sodiated positive electrode. | battery |
This paper first derives a model to describe a class of Na–metal–halide secondary batteries, using molten sodium as the anode, NASICON as the sodium-ion-conducting separator, and copper-iodide chemistry in an aqueous electrolyte for the cathode. The model is based upon solving transient conservation equations using a Nernst–Planck–Poisson (NPP) formulation. The broad objective is to develop a predictive model that can assist the design and development of large-scale grid-storage batteries. However, the model-predicted results and discussion are focused on a laboratory-scale battery. Several examples are discussed, considering the effects of current density and catholyte molar concentrations on battery performance. | battery |
The role of catalysts in vanadium flow batteries (VFBs) has been studied by introducing bismuth (Bi) nanoparticles on carbon felt (CF) and graphite felt (GF). The electrocatalytic activity and VFBs performance of CF and GF before and after modification with Bi nanoparticles are investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and VFB single cell charge–discharge test. The results show that CF exhibits the much higher electrocatalytic activity than GF, due to its higher amount of C–OH and quaternary nitrogen groups and more defect sites. Bi nanoparticles can effectively improve the electrocatalytic activity of CF and GF, especially GF, towards V2+/V3+ redox couple in VFBs. As a result, energy efficiency of a VFB with GF electrodes can be improved significantly by modification with Bi due to the dramatically reduced electrochemical polarization. However, the energy efficiency of a VFB with CF electrodes rarely changes after introduction of Bi nanoparticles, due to the fact that dominant limitation in a VFB with CF electrodes is ohmic polarization, and the reduced charge transfer resistance is not enough to improve the performance of this VFB remarkably. Therefore, CF is a more suitable electrode material for commercialized VFBs due to its higher electrocatalytic activity and lower cost. | battery |
The paper defines the methods for maintenance of maximum density (Nmax) in respect of the freshwater crayfish (Astacus leptodactylus) fingerlings (larvae/juveniles), a prospective model organism for aquaculture. The question of optimal maintenance of the fingerlings has been addressed in the present study, considering the following parameters: (1) the ratio between the total area on which the fingerlings are being grown, and the area occupied by one individual, and (2) the planting density dependence on the specific growth rate of differently aged individuals (Cw). Analysis of our results shows that the Nmax values decrease significantly with the growth of individuals (4167, 2222 and 617 ind. m−2 for 30, 65 and 120 days old fingerlings, respectively). The values of Cw for individuals at the age of 30 days, however, do not depend on rearing density within the range of 300–1500 ind. m−2. A linear decrease in Cw is observed in density gradient for older ages. The density at which Cw becomes equal to zero is 3553 ind. m−2 for 65 days old fingerlings, and 1307 ind. m−2 for the 120 days old ones. The revealed differences (with respect to growth rates and planting densities in different age groups) may presumably be caused by the influence of the specific mechanisms of an intra-populational regulation, tenable with the conditions of high densities of fingerlings.
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In a battery pack, cell-to-cell chemical variation, or the variation in operating conditions, can possibly lead to current imbalance which can accelerate pack ageing. In this paper, the Pseudo-Two-Dimensional(P2D) porous electrode model is extended to a battery pack layout, to predict the overall behaviour and the cell-to-cell variation under constant voltage charging and discharging. The algorithm used in this model offers the flexibility in extending the layout to any number of cells in a pack, which can be of different capacities, chemical characteristics and physical dimensions. The coupled electro-thermal effects such as differential cell ageing, temperature variation, porosity change and their effects on the performance of the pack, can be predicted using this modelling algorithm. The pack charging voltage is found to have an impact on the performance as well as the SEI layer growth. Numerical studies are conducted by keeping the cells at different thermal conditions and the results show the necessity to increase the heat transfer coefficient to cool the pack, compared to single cell. The results show that the thermal imbalance has more impact than the change in inter-connecting resistance on the split current distribution, which accelerates the irreversible porous filling and ageing. | battery |
Hurricanes can pose a greater threat for small islands if larger and more frequent storms are the future reality due to climate change. Apart from property damage, hurricanes can damage natural coastal communities and wash solid waste into coastal waters and wetlands. Our goal was to develop a rapid, synoptic survey method to evaluate what happens to the coasts of small islands after hurricanes. This study reports on the development of a hurricane rapid ecological assessment method (H-REA) that was carried out on small islands in collaboration with local communities. The H-REA focused on property damage, vegetation damage, flooding, coastal erosion, and solid waste accumulation in the coastal environment. The H-REA method was developed to evaluate the hurricane damage from Hurricane Matthew in 2016 and then applied to assess Hurricane Irma’s damage to both the built and natural environments in 2017. The H-REA proved to be an important tool for the rapid assessment of 2017 hurricane impacts on the southern Bahamian islands; results are shown for Great Exuma. The H-REA results highlighted the variability of damage across the islands as well as the value of coastal set-backs and protected coastal wetlands in reducing both property damage and the amount of solid waste, including plastics, entering the coastal oceans. A spatial database was established to visualize the patterns of building damage, flooding, and vegetation loss; the spatial database allows for the assessment of damage from successive hurricanes.
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This study analyzes the effect of increased thermal conductivity in energy storage, using paraffin wax with 8% w/w of aluminum foils, obtained from waste materials. Three configurations previously not published of the aluminum foil were tested: stripes, horizontal perforated disks and vertical perforated foils. The aluminum foils doubled the thermal conductivity, achieving values of 0.63 W/mK, without significant statistical influence of the metallic configuration inside this material. Solidification time depended on the configuration of the aluminum foils, where differences of up to 38% were detected between horizontal perforated disks and stripes. The equations for the solidification process were numerically solved in Matlab using the finite volume method, finding good agreement for the simulated output air temperature when compared with experimental values (relative error <10 %). Later, a thermal energy accumulator was designed and assessed, which consisted of 12 cans with paraffin wax, using the horizontal perforated disks configuration. The energy stored by the phase change material was removed with air velocities between 0.5 − 1.5 m/s, reaching efficiencies close to 90% for the maximum air velocity. | battery |
This paper proposes a new control and power management strategy for a grid-connected microgrid, which includes a hybrid renewable energy sources (HRES) system and a three-phase load. The HRES system consists of a photovoltaic (PV), a battery storage system (BSS), a super-capacitor (SC) and a solid oxide fuel cell (SOFC). The dynamic model of each of these units is described. The PV is the main energy source, while the SC and the BSS due to their various power densities are considered to provide a steady and transient load demand, respectively. For increasing the reliability of the system, SOFC source is selected to keep the BSS completely charged. All these units with different DC-DC converters are connected in parallel to a common DC bus. Then, a three-phase voltage source inverter (VSI) is employed to convert the DC voltage to AC. To maintain the power balance and appropriate load-sharing, an adaptive fractional fuzzy sliding mode control (AFFSMC) strategy for VSI-based HRES system is presented. The controller is able to track the pre-defined instruction precisely and quickly in the microgrid. For stable performance of the control strategy under load variation, a fractional order-based sliding surface is considered. Moreover, fractional adaptive rules-based fuzzy sets are employed to accurately estimate the uncertain parameters in the microgrid. The simulation results demonstrate the effectiveness and capability of an AFFSMC strategy under various faults and different loading conditions. Moreover, the proposed control strategy is compared with the conventional PI controller. | non-battery |
Substantial correlational evidence suggests that prefrontal regions are critical to honest and dishonest behavior, but causal evidence specifying the nature of this involvement remains absent. We found that lesions of the human dorsolateral prefrontal cortex (DLPFC) decreased the effect of honesty concerns on behavior in economic games that pit honesty motives against self-interest, but did not affect decisions when honesty concerns were absent. These results point to a causal role for DLPFC in honest behavior.
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Variability and intermittency are some of the main features that characterize renewable energy sources. Intermittency usually includes both predictable and unpredictable variations. The many drawbacks of intermittency of renewable sources can be overcome by considering some special design considerations. Integrating more than one renewable energy source and including backup sources and storage systems are among the few measures to overcome these drawbacks. These additional design considerations usually increase the overall cost of the renewable system. Furthermore, the presence of more than one energy supply/storage system requires the control of energy flow among the various sources. Therefore, optimizing the size of the components and adopting an energy management strategy (EMS) are essential to decreasing the cost of the system and limiting its negative effects. The energy management strategy is commonly integrated with optimization to ensure the continuity of load supply and to decrease the cost of energy production. Therefore, energy management is a term that collects all the systematic procedures to control and minimize the quantity and the cost of energy used to provide a certain application with its requirements. The energy management strategy usually depends on the type of energy system and its components. Various approaches and techniques have been used to develop a successful energy management strategy. In this paper, a comprehensive review of the approaches proposed and used by authors of many papers is conducted. These approaches include both the standalone hybrid renewable energy systems and the grid-connected hybrid renewable systems. More attention is focused on popularly used techniques to address the features of each system. The selected papers in this review cover the various configurations of the hybrid renewable energy systems for electric power generation only. | battery |
The metabolic dependencies of androgen receptor (AR)-driven growth in prostate adenocarcinoma are largely unknown but could represent a therapeutic target when hormonal manipulations fail. Here the authors demonstrate that the mitochondrial pyruvate carrier (MPC) is transcriptionally regulated by AR and that MPC inhibition suppresses tumour growth in hormone-responsive and castrate-resistant conditions.
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The effect of crowding on the identification of words was examined in normal readers and subjects with developmental dyslexia. In Experiment 1, a matching task was used. Words were presented either alone or embedded in other words. Vocal reaction times (RT) of dyslexics were slower and more sensitive to the presence of the surrounding stimuli than those of control subjects. Similar results were obtained in a control experiment using the same task for strings of symbols (isolated or crowded) instead of words. These data indicate that differences in crowding in control and dyslexic subjects arise at a pre-linguistic level. In Experiment 2, vocal RTs to word reading were measured. Two conditions putatively reducing the effect of crowding were tested: increasing inter-letter spacing and blurring. A moderate increase of inter-letter spacing produced faster vocal RTs in dyslexics, while no effect was present in normal controls. Moderate blurring of stimuli did not change dyslexics' RTs, while normal readers became slower. Group and individual results are discussed to evaluate the extent to which crowding contributes to the genesis of developmental dyslexia. | non-battery |
Developmental dyslexia is the most common learning disability in school-aged children with an estimated incidence of five to ten percent. The cause and pathophysiological substrate of this developmental disorder is unclear. Recently, a possible involvement of the cerebellum in the pathogenesis of dyslexia has been postulated. In this study, 15 dyslexic children and 7 age-matched control subjects were investigated by means of functional neuroimaging (fMRI) using a noun-verb association paradigm. Comparison of activation patterns between dyslexic and control subjects revealed distinct and significant differences in cerebral and cerebellar activation. Control subjects showed bilaterally well-defined and focal activation patterns in the frontal and parietal lobes and the posterior regions of the cerebellar hemispheres. The dyslexic children, however, presented widespread and diffuse activations on the cerebral and cerebellar level. Cerebral activations were found in frontal, parietal, temporal and occipital regions. Activations in the cerebellum were found predominantly in the cerebellar cortex, including Crus I, Crus II, hemispheric lobule VI, VII and vermal lobules I, II, III, IV and VII. This preliminary study is the first to reveal a significant difference in cerebellar functioning between dyslexic children and controls during a semantic association task. As a result, we propose a new hypothesis regarding the pathophysiological mechanisms of developmental dyslexia. Given the sites of activation in the cerebellum in the dyslexic group, a defect of the intra-cerebellar distribution of activity is suspected, suggesting a disorder of the processing or transfer of information within the cerebellar cortex. | non-battery |
An easy to fabricate and versatile cell that can be used with a variety of electrochemical techniques, also meeting the stringent requirement for undertaking cyclic voltammetry under transient conditions in in situ electrocrystallization studies and total external reflection X-ray analysis, has been developed. Application is demonstrated through an in situ synchrotron radiation-grazing incidence X-ray diffraction (SR-GIXRD) characterization of electrocrystallized cadmium (II)-tetracyanoquinodimethane material, Cd(TCNQ)2, from acetonitrile (0.1moldm−3 [NBu4][PF6]). Importantly, this versatile cell design makes SR-GIXRD suitable for almost any combination of total external reflection X-ray analysis (e.g., GIXRF and GIXRD) and electrochemical perturbation, also allowing its application in acidic, basic, aqueous, non-aqueous, low and high flow pressure conditions. Nevertheless, the cell design separates the functions of transient voltammetry and SR-GIXRD measurements, viz., voltammetry is performed at high flow rates with a substantially distended window to minimize the IR (Ohmic) drop of the electrolyte, while SR-GIXRD is undertaken using stop-flow conditions with a very thin layer of electrolyte to minimize X-ray absorption and scattering by the solution. | battery |
As the lightest and most electropositive material, lithium metal is regarded as the ultimate anode material for next-generation high-energy batteries. However, uncontrolled dendritic lithium growth as well as low Coulombic efficiency hinders its widespread application in secondary batteries. Interfacial modification of anodes with protective layers has been proved to be an effective way to inhibit the growth of ramified lithium. Here we report on a freestanding, highly flexible nanostructured carbon film, which is ready to be transferred onto electrodes with great ease. We show that such mechanically robust carbon films can effectively suppress the growth of Li dendrites upon cycling at practical current densities (0.25–1.0mAcm−2) with significantly improved Coulombic efficiency up to ~99.5% for over hundreds of cycles and thousands of operation hours. Notably, this semi-tubular carbon film demonstrated instant, reliable protection to electrodes in not only reactive electrolytes but also ambient environment with high humidity, offering a practically feasible route toward the dendrite-free lithium metal batteries. | battery |
Disordered surface of anode materials accompanied by oxygen vacancies, has been developed as an efficient strategy to promote their charge-transfer kinetics and then improve their electrochemical properties. It is rarely explored for cathode materials before. Here, LiTi2-x Mn x (PO4-y )3 nanoparticles with a disordered surface and oxygen vacancies, are synthesized by a hydrothermal method following with an annealing in Ar/H2. Their disordered surface and heteroatom doping by reduced Mn/Ti species, have been supported by HRTEM images, XPS and EDS spectra. After 120 cycles at 0.2 C, these nanoparticles still deliver a capacity of 127 mAh g−1, much higher than the product without any doping, and that without a disordered surface. Even after 500 cycles, the capacity is still at 101 mAh g−1 for 5 C or at 71 mAh g−1 for 20 C. These results could be attributed to the reduced charge-transfer resistance caused by disordered surface, and the enhanced lithium-diffusion induced by doping. | battery |
H2V3O8 nanobelts have been successfully synthesised from commercial V2O5 powder through a fast and environmental friendly microwave-hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, thermogravimetric analysis, infrared spectroscopy, high-resolution transmission electron microscopy and ICP spectroscopy were used to characterise the morphology and structure–microstructure details. Nanobelts about 100 nm wide and several micrometres long are easily prepared in no more than 2 h. The electrochemical study reveals the reversible insertion of ca. 4 Li per formula unit (400 mAh g−1), through several pseudo-plateaus in the 3.75–1.5 V vs Li+/Li voltage range showing the interest of this material produced by a “green” route as an electrode for lithium rechargeable batteries. After the first cycle a significant capacity loss is observed, though a high capacity, ca. 300 mAh g−1, remains upon cycling. Furthermore, the similarity of discharge and charge curves, pointing to the absence of hydrogen displacement during lithium insertion in H2V3O8, shows that not all protonated systems must be discarded as prospective electrode materials. On the other hand, further reduction down to 1 V is possible to insert up to 5 Li per formula unit (480 mAh g−1). Interestingly it corresponds to full reduction of vanadium to V3+ as it is also confirmed by EELS experiments. However, the full reduction to V3+ is associated with a fast decay of the extra capacity developed at low voltage with increasing current rate. Then for practical use we may consider only the capacity obtained down to 1.5 V. | battery |
Understanding the activity and stability of oxygen-evolving anodes is crucial for developing better water splitting electrolysers. Researchers now show the importance of interactions between iron and hydr(oxy)oxide hosts in dynamically-stable electrocatalysts that balance dissolution and deposition of iron present in the electrolyte. | battery |
We report the characterization of a redox polyelectrolyte based on ferrocenated imidazolium and imidazole repeating units to evaluate the impact of the charged structure on the electron transfer rates. N-vinyl-N′-(methylferrocene)imidazolium chloride monomer was polymerized in the presence of various amounts of vinylimidazole to obtain the electroactive heteropolymer, as the homopolymerization was unsuccessful due to electrostatic repulsion between the imidazolium monomers. NMR was used to determine the ratio of electroactive to neutral monomers in the polymer. The electrochemistry of a thin film of the polymer casted on the surface of glassy carbon electrode was studied in 1 M NaClO4 aqueous electrolyte. Cyclic voltammetry at low scan rates (i.e. ν < 0.1 V s−1) showed a response close to the expected behavior for a surface-confined process without any significant interactions between the ferrocene redox centers, in contrast with poly(vinylferrocene). At high scan rates (ν > 1 V s−1); the behavior was diffusion-controlled. The diffusion coefficient of the ferrocene centers in the imidazolium polymer is 1.7 × 10−9 cm2 s−1 which is one order of magnitude higher than poly(vinylferrocene), and the standard rate constant, determined by the Nicholson's approach, was k0 = 3.8 × 10−4 cm s−1. These high values are explained by favorable interactions of the electrolyte with the charged imidazolium, providing a fast ion diffusion and pairing with ferrocenium. The potential use of this redox polymer in electrochemical systems is demonstrated via the formation of a composite with electrochemically exfoliated graphite to increase polymer loading. | battery |
Background Previous studies indicate that transcranial direct current stimulation (tDCS) with anode over motor cortex (M1) and cathode over contralateral supraorbital region (SO) may be effective in reducing pain, but these studies are limited in number and have not focused on older adults with osteoarthritis (OA). Objective To evaluate the preliminary efficacy and safety of M1-SO applied tDCS on clinical pain severity and mobility performance in adults with knee OA pain. Methods Forty 50- to 70-year-old community-dwelling participants with knee OA were randomly assigned to receive five daily sessions of 2 mA tDCS for 20 min (n = 20) or sham tDCS (n = 20). We measured clinical pain severity via Numeric Rating Scale, Western Ontario and McMaster Universities Osteoarthritis Index, and Short-Form McGill Pain Questionnaire. In addition, we measured mobility performance using the 6-Minute Walk Test and the Short Physical Performance Battery. Moreover, we obtained a sensation/safety questionnaire and measured cognition changes using the PROMIS-Applied Cognition-Abilities-Short Form 8a. Results Active tDCS over M1-SO significantly reduced Numeric Rating Scale of pain compared to sham tDCS after completion of the five daily sessions, and remained up to three weeks. No other measures were significantly different from sham. Participants tolerated tDCS over M1-SO well without serious adverse effects or cognition changes. Conclusion Although not consistent in all pain measurements, our findings demonstrate promising clinical efficacy for reduction in pain perception for older adults with knee OA. Trial registration ClinicalTrials.gov Identifier NCT02512393. | non-battery |
Porous graphitic carbon materials (PGCs) with a microtubular structure were synthesized by a simple method simultaneously completing graphitization and activation for the mixture of willow catkins, KCl, and different ferric salts. The introduction of KCl was crucial to develop a porous structure. KCl, replacing corrosive KOH or poisonous ZnCl2, greatly decreased the cost for production of PGCs. The resulting material PGCN, which was produced by willow catkins, KCl, and Fe(NO3)3, not only inherited the natural microtubular morphology of willow catkins but also possessed a high graphitization degree and abundant porosity. As such, PGCN could serve as an ideal substrate for MnO2 deposition to alleviate its accumulation and improve its conductivity. The obtained PGCN/MnO2 composite electrode significantly enhanced high specific capacitance 571.1 F g− 1 at 2 A g− 1 based on the mass of MnO2. Even at a high current density of 50 A g− 1, specific capacitance still reached 382.1 F g− 1. Furthermore, the electrode exhibited outstanding cycling stability with only 14.8% degradation after 3000 cycles. This study proposes a novel graphitization–activation way for synthesis of porous graphitic carbon by utilizing biomass waste to alleviate the dependence on non-renewable sources. | battery |
Background/purpose Vagus nerve stimulation (VNS) has been demonstrated to be safe and effective for adults and children with drug-resistant epilepsy and is able to improve most types of epilepsy. The aim of this study, in a paediatric population, was to assess the overall efficacy of vagus nerve stimulation on seizures, to assess tolerability and quality of life. Methods This single-centre, retrospective study reviewed the files of 29 children in whom a vagus nerve stimulator was implanted between 1995 and 2012. The response rate (greater than 50% reduction of the seizure frequency), antiepileptic efficacy according to the type of epilepsy or age at implantation or age at onset of epilepsy, the time-course of seizures, adverse effects, overall quality of life and number of hospitalisations were studied. Results In our population, vagus nerve stimulation achieved a significant reduction in the seizure frequency throughout follow-up (p = 0.015). Response rates were 59% at 3 months, and 66% at 6 months, and the response rate then remained stable at about 70%. Stimulation tended to be more effective in patients with non-idiopathic partial epilepsy than in patients with non-idiopathic and idiopathic generalised epilepsy (0.01 < p < 0.11). No other predictive factors of efficacy were identified. Patients, parents, caregivers reported improvement in overall quality of life in 38% of patients during clinical interviews. A significant reduction in the number of hospitalisations due to a reduction of seizure frequency was observed after implantation (p = 0.03). VNS was stopped because of complications or insufficient efficacy in 9 cases. Conclusion Vagus nerve stimulation is a safe and effective treatment option in children with drug-resistant epilepsy who are not candidates for surgery. | non-battery |
This paper reviews the current status of soft robots in biomedical field. Soft robots are made of materials that have comparable modulus of elasticity to that of biological systems. Several advantages of soft robots over rigid robots are safe human interaction, ease of adaptation with wearable electronics and simpler gripping. We review design factors of soft robots including modeling, controls, actuation, fabrication and application, as well as their limitations and future work. For modeling, we survey kinematic, multibody and numerical finite element methods. Finite element methods are better suited for the analysis of soft robots, since they can accurately model nonlinearities in geometry and materials. However, their real-time integration with controls is challenging. We categorize the controls of soft robots as model-based and model-free. Model-free controllers do not rely on an explicit analytical or numerical model of the soft robot to perform actuation. Actuation is the ability to exert a force using actuators such as shape memory alloys, fluid gels, elastomers and piezoelectrics. Nonlinear geometry and materials of soft robots restrict using conventional rigid body controls. The fabrication techniques used for soft robots differ significantly from that of rigid robots. We survey a wide range of techniques used for fabrication of soft robots from simple molding to more advanced additive manufacturing methods such as 3D printing. We discuss the applications and limitations of biomedical soft robots covering aspects such as functionality, ease of use and cost. The paper concludes with the future discoveries in the emerging field of soft robots.
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Numerous breast cancer patients experience cognitive changes during and after chemotherapy. Chemotherapy-related cognitive impairment can significantly affect quality of life. This pilot study attempted to determine the effects of a compensatory cognitive training on the objective and subjective cognitive functioning of breast cancer patients receiving adjuvant chemotherapy. | non-battery |
The cathode material, LiNi0.8Co0.2O2 was synthesized by acid dissolution method using lithium carbonate, nickel hydroxide (carbonate), cobalt hydroxide (carbonate) as insoluble starting materials, and acrylic acid, which acts as an organic acid as well as a chelating agent. Structural and chemical characterization of the spray-dried xerogel precursor was performed through its compositional and thermogravimetric analysis (TGA), which shows that the xerogel can be expressed as Li[MA]3, where M is the transition metal atom. The electrochemical performance of the synthesized powder was tested manufacturing the coin-type cells with lithium metal as an anode material. With the voltage range of 3.0–4.2V, the capacity retentions after 50 cycles were 98.6 and 94.5%, respectively, for the powders calcined at 800°C for 15 and 20h. At the rate capability test, discharge capacity ratio between 3.0 and 0.5C rate is about 91–84% till 60 cycles. | battery |
This paper presents a detailed analysis of the levelized cost of storage (LCOS) for different electricity storage technologies. Costs were analyzed for a long-term storage system (100MW power and 70GWh capacity) and a short-term storage system (100MW power and 400MWh capacity). Detailed data sets for the latest costs of four technology groups are provided in this paper. The LCOS method allows a cost comparison of technologies in different system designs and various operation modes. The results for the long-term storage show that Pumped-Storage Hydroelectricity has the lowest LCOS among the mature technologies today. Power to Gas technologies, once established on the market, may also provide long-term electricity storage at even lower LCOS. Pumped-Storage Hydroelectricity is also the cheapest technology for short-term storage systems. Battery systems at the moment still have high costs but are expected to have a sharp price decrease in the near future. Power to Gas and adiabatic Compressed Air Energy Storage systems may become cost competitive as short-term storage systems as well. The detailed analysis of the cost components shows that the cost composition is very inhomogeneous among the technologies. Plant design optimized to the application is therefore crucial for cost minimization. Sensitivity analysis shows that for most technologies the amount of energy discharged as well as the cost of electricity purchase are the most influential factors for the LCOS. | battery |