10.1016#j.applthermaleng.2013.06.055.xml		An optical differential scanning calorimeter (DSC) system was used in studying the thermal properties of phase change material (PCM). In this study, several typical PCMs were studied on its thermal properties by the optical DSC system. These PCMs are sodium sulfate (Na2SO4·10H2O), paraffin, n-octadecane, and the paraffin/n-octadecane composites at different mass ratios. The thermal properties and micro-structure change of these PCMs were mainly investigated. The results showed that for Na2SO4·10H2O, paraffin and n-octadecane, the measured phase change temperatures and enthalpies appeared no large relative deviation (<5%) from the theoretic values. A high measurement accuracy of the optical DSC system has been obtained and concluded from the experimental results. For the paraffin/n-octadecane composites, the measured phase change temperatures appeared to be lower than that of paraffin, and could be adjusted from 24.2 °C to 49.6 °C by changing the mass fractions of n-octadecane. The lowest eutectic temperature was obtained at the mass fraction 40% of n-octadecane. The measured phase change enthalpies, however, appeared no large variation between 186.4 J/g (paraffin) and 230.5 J/g (n-octadecane). And according to the micro-photos before and after phase change, n-octadecane existed as crystal particles which disappeared with increasing temperature and finally combined with the paraffin matrix.
10.1016#j.mtcomm.2020.101665.xml		Spinel-type Fe2SiO4 has been one of the materials receiving much attention in the field of new spintronics and optoelectronics materials, due to its promising physical properties of high transparency achieved experimentally. In this research, we systematically investigate the structural stabilities, elastic, optical and magnetic, properties of Fe2SiO4 spinel using the first-principles theory within generalized gradient approximation (GGA) and GGA + U frameworks. With the GGA + U method, Fe2SiO4 is shown to be stable for both spin-up and down calculations. Furthermore, incorporating the Hubbard correction parameter due to the localized Fe-3d electrons produced the bandgap value to be close to available experimental data. Our result reveals additional information on Fe2SiO4 spinel which is useful for molecular magnet and spintronics devices.
10.1016#j.micromeso.2003.11.011.xml		Transparent mesoporous silica films were successfully prepared by spin-coating on silicon wafers at room temperature. The X-ray diffraction patterns of the films indicate that both hexagonal and cubic mesoporous films can be formed by varying the surfactant to silicon mole ratio. These films have reasonable thermal stability and are calcinable up to 670 °C and crack free when thickness is less than 0.5 μm. The calcined films have a thickness of 433±2 nm as measured by cross-sectional scanning electron microscopy. Methylphenothiazine was incorporated into the mesoporous silica films and after photoionization by ultraviolet light, the radical cation photoproduced was characterized by electron spin resonance spectroscopy. Erbium 8-hydroxyquinolinate was incorporated into the mesoporous silica films and the mesoporous silica films with incorporated Er(III) were characterized by photoluminescence and isothermal nitrogen physisorption studies. The characteristics of the silica films were studied by X-ray diffraction, thermal gravimetric analysis, scanning electron microscopy, high resolution transmission electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy and isothermal nitrogen physisorption.
10.1016#j.jallcom.2019.02.277.xml		Oxy-fluoro tellurophosphate glasses with molar composition (40-x)P2O5-20TeO2-20ZnF2-20RO-xEu2O3 (where R = Ca, Sr, and Ba and x = 1) were prepared by melt quenching technique. The structural, optical, and photoluminescent properties were studied for the prepared glass. The Fourier transform infrared (FT-IR) studies revealed the presence of poly-phosphate structure and maximum depolymerization was observed for BaO network modifier mixed glass. The band gap and Urbach energy values were calculated based on the absorption spectra. The intense emission peak was observed at 613 nm (5D0→7F2) under the excitation of 392 nm, which matches well with the emission of commercial near ultraviolet (n-UV) LED chips. The highest emission intensity and quantum efficiency were observed for BaO network modifier mixed glass. Based on these results, BaO network modifier glass samples with molar composition (40-x)P2O5-20TeO2-20ZnF2-20BaO-xEu2O3 (x = 3, 5, 7, and 9) were prepared to optimize the emission intensity. The optimized doping concentration of Eu2O3 was 5 mol% and the Commission International de l’Eclairage (CIE) chromaticity coordinates fall in the red region. The interaction among Eu3+ ions was dipole-dipole in nature, which was confirmed by Dexter theory and Inokuti-Hirayama (I-H) model. The above results suggest the applicability of the glass as a potential red photoluminescent material in photonic devices.
10.1016#0008-6215(94)00249-F.xml		The characterization of the main composite sugars of commercial gelling red algae galactans (agarose, iota and kappa carrageenans) by methanolysis and separation of the methyl glycosides produced by high performance liquid chromatography is described. The methanolysis (methanolic hydrochloric acid strength, temperature, and reaction time) was optimized in order to release monosaccharides in near quantitative yield. The results were compared to those obtained by (1) gas chromatography of the alditol acetates of the neutral sugars released by acid hydrolysis and (2) specific colorimetric determination of the acid-labile 3,6-anhydrogalactosyl residue. Conditions such as methanolic 0.125 M HCl for 1 h at 85°C were sufficient to release all of the galactosidic and 3,6-anhydrogalactosidic bonds for iota carrageenan without apparent degradation of the anhydrogalactosyl unit. However, with the same conditions, the yields of 3,6-anhydrogalactosyl residues were 80 and 70% for kappa carrageenan and agarose, respectively. These yields were not improved by stronger conditions. At the opposite extreme, under very mild methanolysis conditions such as methanolic 0.01 M HCl at 100°C for 1 h, agars and gelling carrageenans were well differentiated by the respective determination of agarobiose- and carrabiose-dimethyl acetal which are well-separated on octadecyl reversed phase HPLC columns with water as eluent.
10.1016#S0960-8974(97)00031-4.xml		The development of II–VI MOVPE is reviewed, contrasting the narrow bandgap materials with the wide bandgap. Common issues are the need to grow the layers at lower temperatures than their III–V cousins in order to avoid point defects. This means that II–VI MOVPE occurs in a surface kinetic regime for precursor decomposition and has stimulated a lot of research on alternative precursors. The narrow bandgap II–VI growers have settled on dimethyl cadmium (DMCd) combined with diisopropyl telluride (DIPTe) and a liquid Hg source but wide bandgap growers are split between pyrolytic and photo-assisted growth. Recent progress in p-type doping has enabled the demonstration of some new devices, including two colour infrared detectors and the first MOVPE grown green emitting laser structure. The common theme appears to be hydrogen passivation of the Group V dopant and some novel precursor solutions to this problem are discussed.10.1016#j.sab.2006.09.006.xml		A fast and simple method using Total Reflection X-ray Fluorescence has been developed for the determination of platinum plasma concentrations of patients undergoing chemotherapy with Pt-bearing drugs. Avoiding chemical digestion, micro liter amounts of blood plasma are employed using Compton peak standardization and the use of matrix-matched spiked samples with known amounts of platinum for spectrometer sensitivity determination. The analytical results with the proposed procedure are compared to values obtained with Graphite Furnace Atomic Absorption Spectrometry obtaining values of comparable accuracy and precision. Measurements of the time course of the Pt plasma concentration in single-dose treatments, and of the achieved plasma concentration of multiple infusion treatments demonstrate the potential usefulness of the method for pharmacokinetic studies or for routine optimization of Pt chemotherapy treatments.
10.1016#j.physe.2011.06.009.xml		Within tight-binding model, the band gaps of armchair and zigzag carbon nanotubes (CNTs) under both uniaxial tensile and torsional strains have been studied. It is found that the changes in band gaps of CNTs depend strongly on the strain type. The torsional strain can induce a band gap for armchair CNTs, but it has little effect on band gap of the zigzag CNTs. While the tensile strain has great effect on band gap of zigzag CNTs, but it has no effect on that of the armchair CNTs. More importantly, when both the tensile and torsional strains are simultaneously applied to the CNTs, the band gap changes of armchair CNTs are not equal to a simple sum over those induced separately by uniaxial tensile and torsional strains. There exists a cooperative effect between two kinds of strains on band gap changes of armchair CNTs. But for zigzag CNTs, the cooperative effect was not found. Analytical expressions for the band gaps of armchair and zigzag CNTs under combined uniaxial–torsional strains have been derived, which agree well with the numerical results.
10.1016#j.jcrysgro.2011.07.012.xml		TaN x  thin films were grown at temperatures ranging from 200 to 375°C using atomic layer deposition (ALD). Pentakis(dimethylamino)tantalum (PDMAT) was used as a tantalum source with either ammonia or monomethylhydrazine (MMH) as a nitrogen co-reactant. Self-limiting behaviour was observed for both ammonia and MMH processes, with growth rates of 0.6 and 0.4Å/cycle, respectively at 300°C. Films deposited using ammonia were found to have a mono-nitride stoichiometry with resistivities as low as 70mΩcm. In contrast, films deposited using MMH were found to be nitrogen rich Ta3N5 with high resistivities. A Quartz Crystal Microbalance (QCM) was used to measure mass gain and loss during the cyclic ALD processes and the data was used in combination with medium energy ion scattering (MEIS) to elucidate the PDMAT absorption mechanisms.
10.1016#j.jmst.2017.07.012.xml		As structural materials, closed-cell aluminum foams possess obvious advantages in product dimension, strength and process economics compared with open cell aluminum foams. However, as a kind of structure-function integration materials, the application of closed-cell aluminum foams has been restricted greatly in acoustic fields due to the difficulty of sound wave penetration. It was reported that closed-cell foams with macrostructures have important effect on the propagation of sound waves. To date, the relationship between macrostructures and acoustic properties of commercially pure closed-cell aluminum foams is ambiguous. In this work, different perforation and air gap types were designed for changing the macrostructures of the foam. Meanwhile, the effect of macrostructures on the sound absorption coefficient and sound reduction index were investigated. The results showed that the foams with half-hole exhibited excellent sound absorption and sound insulation behaviors in high frequency range (>2500Hz). In addition, specimens with air gaps showed good sound absorption properties in low frequency compared with the foams without air gaps. Based on the experiment results, propagation structural models of sound waves in commercially pure closed-cell aluminum foams with different macrostructures were built and the influence of macrostructures on acoustic properties was discussed.
10.1016#j.optmat.2010.08.009.xml		We have prepared macroporous Y3Al5O12 (YAG) monoliths doped with rare earth (RE) ions (RE=Ce, Eu, Sm, and Pr) via the ionic precursor-derived sol–gel reaction accompanied by phase separation and investigated their fluorescence and scattering properties. YAG monoliths with well-defined bicontinuous macropores and skeletons were synthesized from the mixture of water and ethanol containing yttrium(III), aluminum(III), and RE(III) salts using propylene oxide as a gelation initiator and poly(ethylene oxide) as a phase separation inducer. X-ray diffraction measurements reveal that the sample as-dried and that heat-treated at 700°C are amorphous, while a single crystalline phase of YAG is precipitated in the samples heat-treated at temperatures between 800 and 1100°C. The macroporous YAG:RE ceramics heat-treated at 800°C and higher temperatures exhibit fluorescence due to 4f–5d (Ce3+) and 4f–4f (Eu3+, Sm3+, Pr3+) electronic transitions characteristic of the RE ions occupying the eight-coordinated dodecahedral sites in YAG lattice. Coherent backscattering experiments indicate that the scattering strength is enhanced by the densification of skeletons in macroporous YAG monoliths, depending on the heat treatment temperature.
10.1016#j.ceramint.2014.03.160.xml		Pure BaCo2 W-type hexaferrites i.e. BaCo2−x Mg x Fe16O27 (x≤1) have been synthesized by the chemical co-precipitation method at 1223K and have been investigated for their structural, electrical and dielectric properties. The X-ray diffraction (XRD) patterns conformed to the standard single phase of the hexagonal W-type structure. We examined the surface morphology of the prepared samples by the use of scanning electron microscopy (SEM) analysis. The dc-electrical resistivity (ρ) measurements showed metal to semiconductor transition (T  M–S ), in a temperature range of 298–663K. The maximum, at which the T  M–S  occurs, varies with the magnesium concentration in the samples. Crystallographic distribution of Mg2+ cations was responsible for the variation in the overall resistivity (ρ) pattern of BaCo2-W type hexaferrites. The dielectric constant (ε  ′ ) and the dielectric loss (tan δ) measurements at room temperature showed normal behavior of hexaferrites. The obtained results indicated that the Mg2+ ions played an important role in the tuning of the electric and the dielectric properties of BaCo2-W hexaferrites, which might have possible applications in transformer cores to reduce the eddy current losses.
10.1016#j.ijadhadh.2011.01.002.xml		The mechanical and adhesives properties of epoxy formulations based on diglycidyl ether of bisphenol A cured with various aliphatic amines were evaluated in the glass state. Impact tests were used to determine the impact energy. The adhesive properties have been evaluated in terms single lap shear using steel adherends. Its durability in water at ambient temperature (24°C) and at 80°C has also been analyzed. The fracture mechanisms were determined by optical microscopy. It was observed a strong participation of the cohesive fracture mechanisms in all epoxy system studied. The 1-(2-aminoethyl)piperazine epoxy adhesive and piperidine epoxy adhesive presents the best adhesive strength and the largest impact energy. The durability in water causes less damage to piperidine epoxy networks. This behavior appears to be associated with the lower water uptake tendency of homopolymerised resins due to its lower hydroxyl group concentration.
10.1016#j.bios.2015.08.005.xml		A silver nanoparticles (AgNPs)-enhanced time-resolved fluorescence (TR-FL) sensor based on long-lived fluorescent Mn-doped ZnS quantum dots (QDs) is developed for the sensitive detection of vascular endothelial growth factor-165 (VEGF165), a predominant cancer biomarker in cancer angiogenesis. The aptamers bond with the Mn-doped ZnS QDs and the BHQ-2 quencher-labelling strands hybridized in duplex are coupled with streptavidin (SA)-functionalized AgNPs to form the AgNPs-enhanced TR-FL sensor, showing lower fluorescence intensity in the duplex state due to the fluorescence resonance energy transfer (FRET) between the Mn-doped ZnS QDs and quenchers. Upon the addition of VEGF165, the BHQ-2 quencher-labelling strands of the duplex are displaced, leading to the disruption of the FRET. As a result, the fluorescence of the Mn-doped QDs within the proximity of the AgNPs is recovered. The FL signal can be measured free of the interference of short-lived background by setting appropriate delay time and gate time, which offers a signal with high signal-to-noise ratio in photoluminescent biodetection. Compared with the bare TR-FL sensor, the AgNPs-based TR-FL sensor showed a huge improvement in fluorescence based on metal-enhanced fluorescence (MEF) effect, and the sensitivity increased 11-fold with the detection limit of 0.08nM. In addition, the sensor provided a wide range of linear detection from 0.1nM to 16nM.
10.1016#j.optcom.2010.03.059.xml		Molybdenum oxide thin films were prepared by pulsed laser deposition. The as-deposited films were dark. Annealing the films in air at 400°C resulted in transparent films. These films were further annealed in vacuum at 300 and 400°C to investigate thermocoloration. The structural, chemical, and optical properties of the films were determined. All films were predominantly amorphous. The air-annealed films were nearly stoichiometric. However, after annealing in vacuum at 400°C, the films became oxygen-deficient. The transmittance of the films progressively decreased as the vacuum-annealing temperature increased, indicating stronger coloration of the films. The optical constants were determined from the transmittance measurements. Both the refractive index and extinction coefficient increased upon vacuum annealing. However, the band gap slightly decreased after vacuum annealing.
10.1016#j.msec.2013.10.037.xml		Ti–25Nb–3Mo–3Zr–2Sn (TLM) substrates, which consist of pure β phase and duplex α+β phases were achieved by different heat treatment. Different substrates with and without α phase were subjected to surface mechanical attrition treatment (SMAT) for 5 and 30min, respectively. Investigated by transmission electron microscopy (TEM), it is found that the content and morphology of α phase in the TLM substrates play crucial roles in nanocrystallization of the alloy. During SMAT, the substrates composed of duplex α+β phases are much easier to nanocrystallized than that composed of pure β phase, and the duplex-phase substrate containing 35vt.% α needles is more inclined to grain refinement than those substrates containing 27vt.% α cobbles and 31vt.% α needles. Accompanied with the nanocrystallization in the surface layers of the duplex-phase substrates, the stress induced α-to-β phase transition occurs. In addition, employing hFOB1.19 cells, the behaviors of osteoblasts on the unSMATed and as-SMATed surfaces were evaluated by examining the morphology and viability of the cells. It shows that the SMAT-induced grain refinement in the surface layer of the alloy can significantly improve the osteoblast response. Our study lays the foundation for nanostructuring β titanium alloys to be used as biomedical implants.
10.1016#j.jelechem.2007.09.033.xml		Different immobilization procedures for horseradish peroxidase (HRP) were investigated using, as support matrices, self-assembled monolayers (SAM) formed on gold electrodes. The influences of these immobilization processes in the biosensor performance were also evaluated. For this, monolayers were prepared from thiols with different structures, carbon chain sizes and terminal groups. It was shown that the thiol carbon chain size influences especially in monolayer coverage and, consequently, in the biomolecule immobilization efficiency. From the studies carried out for SAM characterization on the electrode surface it was verified that thiols with shorter chains (n <9) tend to form monolayers with a considerable amount of defects on the gold surface that lead to a lower coverage. However, thiols with a longer carbon chain present a higher coverage degree, which are not suited as substrate to the development of electrochemical biosensors, because they passivate the transduction interface, making difficult the electron transfer and, consequently, reducing electrode sensitivity. In relation to the enzyme immobilization on gold electrodes, it was verified, using different techniques, that monolayers that possess –NH2 terminal groups provided the best results, probably due to the use of glutaraldeyde as ligand during the immobilization process. Analyzing biosensor performances for hydrogen peroxide, it was verified that SAM formed by cysteamine is the most adequate for HRP immobilization, because it provides better efficiency for enzyme immobilization associated to high sensitivity for H2O2.
10.1016#S1872-2067(20)63623-3.xml		The solar-driven catalytic conversion of CO2 to useful chemical fuels is regarded as an environmentally friendly approach to reduce the consumption of fossil fuels and mitigate the greenhouse effect. However, it is highly intriguing and challenging to promote the selectivity and efficiency of visible-light-responsive photocatalysts that favor the adsorption of CO2 in photoreduction processes. In this work, three-dimensional hierarchical Cd0.8Zn0.2S flowers (C8Z2S-F) with ultrathin petals were successfully synthesized through an in-situ self-assembly growth process using sodium citrate as a morphology director. The flower-like Cd0.8Zn0.2S solid solution exhibited remarkable photocatalytic performance in the reduction of CO2, generating CO up to 41.4 μmol g−1 under visible-light illumination for 3 h; this was nearly three times greater than that of Cd0.8Zn0.2S nanoparticles (C8Z2S-NP) (14.7 μmol g−1). Particularly, a comparably high selectivity of 89.9% for the conversion of CO2 to CO, with a turnover number of 39.6, was obtained from the solar-driven C8Z2S-F system in the absence of any co-catalyst or sacrificial agent. Terahertz time-domain spectroscopy indicated that the introduction of flower structures enhanced the light-harvesting capacity of C8Z2S-F. The in situ diffuse reflectance infrared Fourier transform spectroscopy unveiled the existence of surface-adsorbed species and the conversion of photoreduction intermediates during the photocatalytic process. Empirical characterizations and predictions of the photocatalytic mechanism demonstrated that the flower-like Cd0.8Zn0.2S solid solution possessed desirable CO2 adsorption properties and an enhanced charge-transfer capability, thus providing a highly effective photocatalytic reduction of CO2.
10.1016#j.ceja.2021.100105.xml		The graphene oxide @nickel phosphate (GO:NPO) nanocomposites (NCs) are prepared by using a one-pot in-situ solar energy assisted method by varying GO:NPO ratio i.e. 0.00, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, and 2.00 without adding any surfactant or a structure-directing reagent. As produced GO:NPO nanosheets exhibited an improved photocatalytic activity due to the spatial seperation of charge carriers through interface, where photoinduced electrons transferred from NiPO4 to the GO sheets without charge-recombination. Out of the series, the system 1.00 GO:NPO NC show the optimum hydrogen production activity (15.37 μmol H2 h−1) towards water splitting under the visible light irradiation. The electronic environment of the nanocomposite GO-NiO6/NiO4-PO4 elucidated in the light of advance experimental analyses and theoretical DFT spin density calculations. Structural advanmcement of composites are well correlated with their hydrogen production activity.
10.1016#j.tsf.2016.07.027.xml		Phase pure Cu2SnSe3 thin films were successfully obtained on glass substrates by annealing of successive ionic layer adsorption and reaction (SILAR) deposited thin films at 623K for an hour in selenium atmosphere. Structural, morphological, compositional, and optical properties of films were investigated, before and after annealing, via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Raman spectroscopy, and optical absorption measurements. XRD results showed that films were polycrystalline nature with cubic structure, the crystallinity was improved with annealing and the secondary phase of SnSe disappeared as well. SEM images revealed existence of the relatively big islands, which were formed overlapping large number of small grains, was observed on the surfaces. The images also showed a considerable change in the shape of the grains with annealing. EDAX measurements revealed that chemical composition of the annealed film was very close to the ideal value 2:1:3. The results of Raman measurement confirmed the formation of Cu2SnSe3 and disappearance of the secondary phase of SnSe after annealing. The optical absorption studies showed that the films have direct transitions with band gap energies of 1.38eV and 1.34eV before and after annealing, respectively.
10.1016#j.saa.2004.09.025.xml		Electron paramagnetic resonance (EPR) and optical absorption spectra of vanadyl ions in zinc lead borate (ZnO–PbO–B2O3) glass system have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of VO2+ ions. The values of spin-Hamiltonian parameters indicate that the VO2+ ions in zinc lead borate glasses were present in octahedral sites with tetragonal compression and belong to C4V symmetry. The spin-Hamiltonian parameters g and A are found to be independent of V2O5 content and temperature but changing with ZnO content. The decrease in Δg ∥/Δg ⊥ value with increase in ZnO content indicates that the symmetry around VO2+ ions is more octahedral. The decrease in intensity of EPR signal above 10mol% of V2O5 is attributed to a fall in the ratio of the number of V4+ ions (N 4) to the number of V5+ ions (N 5). The number of spins (N) participating in resonance was calculated as a function of temperature for VO2+ doped zinc lead borate glass sample and the activation energy was calculated. From the EPR data, the paramagnetic susceptibility was calculated at various temperatures and the Curie constant was evaluated from the 1/χ–T graph. The optical absorption spectra show single absorption band due to VO2+ ions in tetragonally distorted octahedral sites.
10.1016#j.rinp.2018.11.013.xml		A novel design of Hexa Sectored Photonic Crystal Fiber (HS-PCF) with high nonlinearity and high birefringence has been revealed in this paper where core is slotted and filled with Gallium Phosphide (GaP). Finite Element Method has been used for numerical investigation of the proposed PCF along with finer mesh. Different optical parameters like nonlinearity, effective area, power fraction, birefringence, confinement loss and Numerical Aperture (NA) have been explored by proper tuning of Geometrical variables. The investigation shows that, proposed PCF exhibits high nonlinearity of 9.47 × 104 W−1Km−1 at the operating wavelength of 1.4 μm along with high birefringence of 0.259, Numerical aperture of 0.8774 and very low confinement loss of 5.78 × 10−9 dB/m at the optical wavelength of 2.0 μm. Therefore, it is expected that this proposed PCF could be a strong candidate in biomedical imaging, super continuum generation and sensing applications considering polarized light.
10.1016#j.ancr.2015.10.003.xml		In the present work, we have synthesized a new water soluble colorless chemical compound 7-O-tert-butyldiphenylsilyl-4-methylcoumarin (TBDPSC) that releases fluorescent molecules imparting blue fluorescence to the solution, upon interaction with fluoride ions in water. The blue fluorescence can be visualized using simple hand held ultraviolet (UV) lamps. TBDPSC has excellent sensitivity and selectivity towards fluoride and our results indicate that fluoride concentrations as low as 0.2 mg/L can be accurately detected within a few seconds. Fluoride testing with TBDPSC is simple and rapid compared to the conventional methodologies without the requirement of trained personnel. Hence, the present fluoride detection method can be easily field deployable and particularly useful for monitoring water quality in limited resource communities.
10.1016#j.elecom.2007.01.043.xml		The gelation of multi-component solvent mixtures with lithium salts was investigated in the presence of gelator 4, 4′bis(stearoylamino)diphenyl ether (BSDE). Ordered structures can be formed by non-covalent interactions in both miscible and non-miscible solvent mixtures. In a non-miscible solvent mixture, there was a soluble competition for BSDE, which can be explained by the different polarities of the solvents. The presence of lithium salt in the solvent mixtures seems to not affect the microscopic morphologies of the aggregates. TEM and SEM images of the gels indicated that BSDE aggregated and self-assembled into flexual, wrinkled and interconnected sheets in the solvent mixtures. These sheet-like aggregates are different from the fibril-like aggregates formed in single component solvents as reported previously. The ion conductivity of the organogels formed by these solvent mixtures confirms that the three-dimensional network does not affect the ions diffusion in the large interconnected liquid domains. The organogels of solvent mixtures containing lithium salts exhibit high conductivities which are in the range of 10−1–10−2 Scm−1 at room temperature, and in the range of 10−3–10−4 Scm−1 at −40°C.
10.1007#s11244-012-9826-y.html		A wide range of metal halides and triflates were examined for the conversion of d-glucose to HMF in DMSO. Chromium and aluminium salts were identified as the most promising catalysts. The effect of process variables like initial d-glucose concentration (0.1–1.5 M), reaction time (5–360 min) and reaction temperature (100–140 °C) on the yield of HMF were examined at a fixed Al(OTf)3 concentration (50 mM). Highest yields of HMF (60 mol%) were obtained using 1 M d-glucose (16 wt%), Al(OTf)3 (5 mol%) at a temperature of 140 °C. A reaction pathway involving initial isomerisation of d-glucose to d-fructose followed by a number of dehydration steps is proposed. Kinetic analysis reveals that the reaction is second order in d-glucose with an activation energy of 138 kJ mol−1.
10.1016#j.tet.2004.08.050.xml		Benzylaminomethyl groups are introduced to the 3,3′-positions of BINOL. The resulting compounds can be used to conduct the enantioselective fluorescent recognition of mandelic acid and N-benzyloxycarbonylphenylglycine. In the presence of (S)-mandelic acid, compound (R)-2  showed over 30-fold fluorescence enhancement with the ef [ef=enantiomeric fluorescence difference ratio=(I S−I 0)/(I R−I 0)] up to 4.2. In the presence of d-N-benzyloxycarbonylphenylglycine, compound (RR)-4  showed up to 15-fold fluorescence enhancement with the ef up to 5.0. These high fluorescence sensitivity and enantioselectivity make compounds (R)-2  and (RR)-4  practically useful sensors for the recognition of the chiral acids in apolar solvents.
10.1016#j.matpr.2020.05.226.xml		In industries Metal Oxides received attention owing to its salient features such as physical, chemical and optical properties. This work focused thickness, film composition, structural and optical properties of Copper Oxide thin films. A low cost, economically friendly electrodeposition technique has been employed to prepare Copper Oxide thin films on Indium doped Tin Oxide conducting glass substrates. Structural features shown that the deposited films have polycrystalline nature with cubic structure. Weight difference method has been used to find out the range of thickness of the deposited films. Energy dispersive X-ray analysis has been carried to determine the film stoichiometry of the deposited films.. Optical properties showed that the deposited films have band gap value around 2.42 eV.
10.1016#j.ijleo.2011.06.002.xml		In recent days amino acid single crystals are gaining importance due to good optical behavior. The title compound consists of l-alanine; an amino acid and maleic acid; an aromatic organic compound. It has been successfully synthesized and the single crystal has been grown by slow evaporation solution growth. The grown single crystal has been characterized by powder X-ray diffraction (PXRD) analysis and FTIR measurements. The crystalline perfection was examined by high-resolution X-ray diffraction (HRXRD) technique and found that the specimen quality is quite good. Optical behavior has been assessed by UV–Vis analysis and found that there is no absorption in the entire visible region. The relative second harmonic generation (SHG) efficiency measurement reveals that the incorporation of maleic acid to l-alanine leads to increase its value of SHG. The mechanical behavior and the thermal analysis have been carried out using Vickers microhardness and TG/DTA measurements respectively. Its hyperpolarizability was estimated by density functional theory (DFT).
10.1016#j.ceramint.2019.09.193.xml		A novel approach to enhance the solar cell efficiency via employing a luminescent downshifting mechanism is presented in this work. Gold metal ions were diffused into a commercially available sodalime silicate glass using a versatile field-assisted solid-state ion diffusion technique under different experimental conditions. Some of these samples were irradiated with ns-laser to segregate the diffused ions into dimers and trimers to enhance their luminescence characteristics. The consequent structural modifications in the glass matrix were examined using Fourier transform infrared spectroscopy. Optical absorption and luminescence measurements were performed to check the presence of resonant plasmonic absorption of nanoclusters and suitability of the samples as luminescent downshifters, respectively. At UV excitation wavelengths (260 and 340 nm), the doped samples downshifted the solar spectrum compared to their undoped counterparts. Furthermore, ns-laser irradiation of the doped samples significantly enhanced the luminescence intensity in comparison to the unirradiated samples. Real-time performance of these samples was tested by measuring the output power of a Si solar cell covered with the treated coverglass when illuminated with a solar simulator. Finally, the Vicker's micro-indentation was applied to conclude that ionic diffusion increased the glass hardness as well.
10.1016#j.jpcs.2014.06.006.xml		Powder ZnAl2O4 (gahnite) samples doped with 0, 4.3, 7.6 and 11.7at% Mn (in relation to Zn) were prepared by a sol–gel technique followed by thermal treatment. The effect of manganese doping on microstructure of the samples has been investigated by transmission electron microscopy and X-ray diffraction. Diffraction patterns showed that all samples were cubic with a spinel structure, space group Fd   3   ̄    m. Diffraction lines were broadened indicating nanocrystalline samples. Transmission electron microscopy investigations confirmed that the samples were nanocrystalline. Particles (grains) in the samples, as observed by transmission electron microscopy, were evenly shaped and grain size distribution could be fitted to a lognormal function. Grain sizes determined by TEM analysis and crystallite sizes obtained from diffraction line-broadening analysis were similar. Both decreased with increasing manganese doping level. Increase in doping level from 0 to 11.7at% Mn caused the change in grain size from 25.0(7)nm to 14.2(3)nm and the change in crystallite size from 24.1(1)nm to 18.0(1)nm. Doping Mn2+ cations acted as defects in the gahnite structure that increased lattice strain from 0.07(1)% for undoped sample to 0.21% for sample doped with 11.7at% Mn, and disturbed the crystallites to grow.
10.1016#j.solidstatesciences.2014.10.005.xml		A facile and effective solution phase reduction method was developed to synthesize graphene-based magnetic metal nanocomposites. Metals (Co, and Ni) or alloys (Fe51Co49, Fe48Ni52, Ni49Co51, Co51Cu49, and Ni52Cu48)/reduced graphene oxide (RGO) nanocomposites were successfully prepared by reduction of the corresponding aqueous metal ions and ethylenediamine (EDA)–graphene oxide (GO) with hydrazine hydrate at 353 K for 1 h under N2 atmosphere. The effects of synthetic parameters such as metal ions concentration, adding sequence of NaOH and N2H4·H2O, linkage agent and reaction time on the formation of nanocomposites were investigated. The experimental results showed that using ethylenediamine and adding sequence played critical roles in the formation of metals or alloys/RGO nanocomposites. Magnetic hysteresis measurements revealed that the as-synthesized metals or alloys in nanocomposites showed excellent soft magnetic behavior with enhanced saturation magnetization, and could have promising applications in biotechnology, catalysis, and magnetic storage devices.
10.1016#j.optcom.2018.11.058.xml		Integrated optical gyros (IOG) draw attention due to the remarkable promise of miniaturization, mass-manufacturability and high reliability. However, the wafer-scale integration of these devices is not available. A heterogeneous platform of lithium niobate (LN) and silicon nitride (Si3N4) waveguide is proposed in this study to enable the integration of phase modulator and resonator firstly, with large polarization intensity extinction ratio and low loss. The optical interlayer coupling between LN and Si3N4 waveguide is realized using Si3N4 bilevel taper above the lithium niobate on insulator (LNOI) substrate. The relationship between polarization intensity extinction ratio and lithium niobate thin film (LNTF) thickness of LN waveguide is developed based on polarization model. The optimal polarization intensity extinction ratio is achieved when the thickness of LNTF is 0. 2  μ m . At the start of the interlayer coupler, the Si3N4 strip with width=0. 9  μ m  and thickness=0.  1  μ m  is designed to maximize the fraction of optical power in the LNTF layer. The polarization intensity extinction ratio of the LN waveguide is 85.6 dB/mm. At the end of the coupler, the optical power in the Si3N4 strip with width of 0. 9  μ m  and thickness of 0. 9  μ m  reaches its maximum. Along the direction of light propagation from LN to Si3N4 waveguide, the optical interlayer coupler with length= 110  μ m  is designed to achieve optical coupling between LN and Si3N4 waveguide while maintaining its state of polarization all the way from the feeder waveguides. The coupling efficiency of the optimized interlayer coupler has been improved to about 99 %.
10.1016#j.polymer.2017.02.012.xml		We prepared cellulose tris(ethylcarbamate) (CTEC), cellulose tris(n-butylcarbamate) (CTBC), and cellulose tris(n-octadecylcarbamate) (CTODC) samples with different molecular weight to determine their conformational properties in dilute solution. Weight average molar masses M w, z-average mean-square radii of gyration 〈S 2〉z, particle scattering functions P(q), and intrinsic viscosities [η] of the CTEC, CTBC, and CTODC samples in tetrahydrofuran (THF) at 25 °C were determined by size exclusion chromatography equipped with multi-angle light scattering detectors (SEC-MALS), small angle X-ray scattering (SAXS), and viscometry. Infrared (IR) absorption measurements were also made to observe intramolecular hydrogen bonding between C=O and NH groups. The obtained 〈S 2〉z, P(q), and [η] data were analyzed in terms of the wormlike chain model to determine the Kuhn segment length (stiffness parameter, or twice of the persistence length) λ −1 and the helix pitch (rise) per residue h. While CTBC has the highest chain stiffness in the three cellulose derivatives as in the case of the corresponding amylose derivatives, the difference in the wormlike chain parameters is less significant for the cellulose alkylcarbamate derivatives. Indeed, intramolecular hydrogen bonding of CTEC, CTBC, and CTODC is weaker and fewer than that for the corresponding amylose derivatives owing to the main chain linkage, α or β.
10.1016#j.nimb.2005.02.014.xml		We report a bi-layer optical waveguide in a Ce-doped strontium barium niobate (SBN) crystal formed by double boron ion implantation. The energies of the B+ and B3+ ions are 3 and 6MeV, respectively, while the doses of the two boron implantation are both 2×1014 ions/cm2. A classic m-lines arrangement is performed to investigate the waveguide properties of the sample. The reconstructed refractive index profile of the waveguide shows a double-barrier confined shape, which suggests the formation of a bi-layer waveguide structure. The thickness of the two guide layers are 2.6 and 4.6μm, respectively, which is in a good agreement with the mean projective range of the implanted boron ions of 3 and 6MeV in the crystal. The nuclear energy loss distribution of the boron ions into SBN has a similar shape to that of the waveguide index, which means an inherent relationship between the waveguide formation and the energy deposition of the energetic ions.
10.1016#j.msec.2016.04.064.xml		In this study, a series of magnetic polyurethane/Fe3O4 elastomer nanocomposites were prepared by covalently embedding novel thiacalix[4]arenes (TC4As) functionalized Fe3O4 nanoparticles (TC4As-Fe3O4) which contain macrocycles with reactive hydroxyl groups. Surface functionalization of Fe3O4 nanoparticles with TC4As macrocycles as unique reactive surface modifier not only gives specific characteristics to Fe3O4 nanoparticles but also improves the interphase interaction between nanoparticles and the polyurethane matrices through covalent attachment of polymer chains to nanoparticle surfaces. The novel synthesized TC4As-Fe3O4 nanoparticles were characterized by FTIR, XRD, TGA, VSM and SEM analysis. Furthermore, the effect of functionalization of Fe3O4 nanoparticles on the various properties of resulting nanocomposites was studied by XRD, TGA, DMTA, SEM, and a universal tensile tester. It was found that the functionalization of nanoparticles with TC4As affords better mechanical and thermal properties to polyurethane nanocomposites in comparison with unmodified nanoparticles. The SEM analysis showed finer dispersion of TC4As-Fe3O4 nanoparticles than unmodified Fe3O4 nanoparticles within the polyurethane matrices, which arising from formation of covalent bonding between TC4As functionalized Fe3O4 nanoparticles and polyurethane matrices. Moreover, the investigation of in vitro biocompatibility of novel nanocomposites showed that these samples are excellent candidate for biomedical use.
10.1016#j.ceramint.2018.09.076.xml		Aurivillius single-phase ceramics of Gd3+ substituted SrBi4Ti4O15 with nominal formula of Sr1-xGd2×/3Bi4Ti4O15 (where x = 0.00, 0.02, 0.04, 0.06, 0.08 and 0.1) herein denoted as SGBT-x have been prepared by using mixed oxide technique. The primary structural analysis from XRD study confirms that orthorhombic distortion to increase with increase in Gd-content, which was strongly supported by Raman spectroscopy. Two of the relaxation mechanisms were clearly identified from cole-cole plot and modulus spectroscopy analysis, which could be discerned to both grain and grain boundary contributions effect. The kinetic study of frequency dependent AC conductivity at various temperature was investigated by using Jonscher's power law equation, σtot(ω)=A(T) ωs + σDC(T); where 0 < s < 1. Close resemblance of obtained activation energy from relaxation mechanism, DC conductivity as well as hopping conduction below transition temperature (TC) suggested that the transport behavior is to originate from oxygen vacancy related hopping mechanism in SGBT-0.08 specimen. In order to further confirm the possible conduction mechanisms in the system the 's' exponent has also been analyzed detail at different temperature regions. Overall we examine that CBH (correlated barrier hopping) and NSPT (non-overlapping small polaron) are two of the appropriate models for conduction process in ferroelectric and paraelectric region respectively. Also the orthorhombic distortion (b/a) of SGBT system plays a major role in the conduction and relaxation process.
10.1016#j.heliyon.2020.e05464.xml		The molecular structural dimerization of biologically potent 2-chloro-5-fluoro phenol (2C5FP) is optimized. A combined experimental and theoretical characteristics of vibrational spectral determinations (NMR, FT-IR and Raman) on 2-chloro-5-fluoro phenol (2C5FP) were used at DFT-B3LYP/6–31++G (d,p) level of computation. A close coherence is achieved when experimentally observed wave numbers are compared with calculated wave numbers by refinement of the scale factors. Calculated values of global chemical descriptors of the present molecule reveal significant molecular stability and chemical reactivity. Non-Linear optical (NLO) property of the present molecule is investigated by determining the second order non linear parameter of first hyperpolarizability β. Moreover, hydrogen bond and thermodynamic parameters at various temperatures are determined and discussed. Investigated compound 2C5FP possesses a better antibacterial activity against Echerichia coli, Streptococcus aureus, Pseudomonas aureus,and Staphylococcus aureus, respectively. The title molecule is subjected to molecular docking studies with two different proteins, namely Staphylococcus aureus Tyrosyl-tRNA synthetase (PDB ID: 1JIL) and human dihydroorotate dehydrogenase (hDHODH) (PDB ID: 6CJF). The results of molecular docking analysis support the antibacterial activity and demonstrate a strong interaction with the DHODH inhibitor.
10.1016#j.triboint.2008.02.019.xml		This paper presents a study concerning the influence of the amount of metallic nanoparticles on the wear behaviour of Fe0.5–Cr0.5–alumina nanocomposites rubbing on Ti–6Al–4V in fretting. Due to the elaboration process (metal–oxide nanopowder prepared by selective reduction in hydrogen of oxide solid solution and densified by spark plasma sintering), these materials generally own two sorts of nanoparticles: the intragranulars (size:  < 10  nm ) located within the alumina grains and the intergranulars (size:  > 100  nm ) located at the grain boundaries. This paper focuses on the role of each sort of nanoparticles with respect to the wear of the nanocomposite. Results show that the presence of intergranular nanoparticles is crucial for improving the wear resistance of nanocomposites whereas the intragranulars rather improve the mechanical properties of matrix grains. The lowest wear rate of the nanocomposite is obtained when the amount of intergranulars is about 3.5wt%. Finally, the fretting wear mechanism of nanocomposites and the mechanism enabling to prevent it by using nanoparticles are both identified and discussed.
10.1016#S0022-3093(97)00481-X.xml		The effect of different processing parameters on the efficiency of entrapment of pH indicators in a sol–gel-derived silica film is reported. An evanescent wave absorption approach was used to monitor dopant-leaching from these films. The issues investigated include the effect on the rate of leaching of the water:alkoxide ratio, the pH of the leachant solution and the choice of silicon alkoxide. Results indicate that the most suitable sol–gel films in terms of leaching and response time are those prepared using tetraethoxysilane as precursor, acid catalysis and a water:alkoxide ratio of at least 4. Leaching is more pronounced for films used directly after preparation and varies for different pH environments. Implications of leaching for the long-term use of sol–gel based pH sensors are discussed.
10.1016#j.solmat.2005.04.014.xml		The electrical conduction properties of ZincPhthalocyanine (ZnPc) thin films have been studied using copper, silver and aluminium electrodes. The sandwich structures were prepared by the thermal evaporation method. The I–V characteristics were investigated to identify the dominant charge transport mechanism in the films. Among all possible mechanisms, it was observed that the data fits well to the SCLC type of conduction in the Al/ZnPc/Al and Schottky type of conduction prevails in the Ag/ZnPc/Ag and Cu/ZnPc/Cu devices. The trap levels and its dependence of structure have been studied and results are discussed. The charge transport phenomenon in the ZnPc films seems to depend highly on the electrode material and temperature. The carrier mobility increases with increasing temperature whereas the density of trapped holes decreases with increasing temperature. The barrier height also decreases with increase in temperature. The influence of the temperature on the electrical parameters such as saturation current density (J s), barrier height (    Φ    b     ), density of states in the valence band edge N d (m−3), the position of the Fermi level E F (eV), ionized acceptor atom density N e (m−3), activation energy    Δ  Φ   (eV), mobilities of hole (    μ   0    ) and the concentration of free holes in the valence band (n 0) have been discussed in detail.
10.1016#S0032-3861(00)00861-2.xml		The molecular shape of well-defined poly(2-ethyl-2-oxazoline) (PEOz) chains in tetrahydrofuran (THF) at room temperature has been studied by a combination of static and dynamic light scattering and viscometry in the framework of the hard-sphere model. Data of the z-average radius of gyration as well as equivalent sphere radii such as the hydrodynamic radius (R H), the viscometric radius (R V), and the thermodynamic radius (R T) give some evidences of sphere-like structure. The unperturbed molecular dimension ((〈R G  2〉0/M w )∞ 1/2=624×10−4  nm) determined by an indirect method and the persistence length q=0.70 nm  determined by the Bushin–Bohdanecky method appear to be quite small compared to those of common flexible polymers. In particular, the R value (24.0), defined by 〈R G 2〉1/2/q, being of a considerably higher order than unity allows an estimation that the chain possibly has a type of “random Gaussian globule”. Based upon the experimental results so far obtained, it can be concluded that the chains of PEOz in THF at 25°C assume basically a shape that is very similar to that of a sphere in the least draining limit. Both the branch-like structure of the PEOz molecule and the intramolecular polar interaction between the nitrogen of the main chain and the carbonyl carbon in the side group are considered to be responsible for the chain contraction.
10.1016#j.jcrysgro.2015.01.019.xml		The bandedge optical properties of GaAsBi films, as thick as 470nm, with Bi content varying from 0.7% Bi to 2.8% Bi grown by molecular beam epitaxy on GaAs substrates are measured by photoluminescence (PL) and photothermal deflection spectroscopy (PDS). The PDS spectra were fit with a modified Fernelius model which takes into account multiple reflections within the GaAsBi layer and GaAs substrate. Three undoped samples and two samples that are degenerately doped with silicon are studied. The undoped samples show a clear Urbach absorption edge with a composition dependent bandgap that decreases by 56meV/% Bi and a composition independent Urbach slope parameter of 25meV due to absorption by Bi cluster states near the valence band. The doped samples show a long absorption tail possibly due to absorption by gap states and free carriers in addition to a Burstein–Moss bandgap shift. PL of the undoped samples shows a lower energy emission peak due to defects not observed in the usually available thin samples (50nm or less) grown under similar conditions.