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21.
A simple and fast complexometric method for the determination of tin in alloys is presented. It is based on the initial complexation of tin with EDTA and its subsequent decomposition with mercaptosuccinic acid. Interference of ions normally encountered in determination of tin was studied. The method has been used for the analysis of alloys such as bronzes, solders, white metal and titanium base alloys. 相似文献
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Indium nitrate and thiourea were used as the precursor solutions for preparing indium sulfide thin films using Chemical Spray Pyrolysis (CSP) technique. Films having various In/S ratios were characterized using X-Ray Diffraction (XRD), Energy Dispersive X-ray Analysis (EDX), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), optical absorption, transmission and photosensitivity measurements. Sample having In/S ratio 2/3 showed better crystallinity with band gap 2.66 eV. Depth profile of the sample also indicated the formation of indium sulfide. It was also observed that In/S ratio in the initial precursor solution determined the composition as well as electrical properties of the films. Maximum photosensitivity was observed for the sample prepared using solution having In/S ratio 2/4. 相似文献
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A primary flexure problem defined by Kirchhoff theory of plates in bending is considered. Significance of auxiliary function introduced earlier in the in-plane displacements in resolving Poisson-Kirchhoff's boundary conditions paradox is reexamined with reference to reported sixth order shear deformation theories, in particular, Reissner's theory and Hencky's theory. Sixth order modified Kirchhoff's theory is extended here to include shear deformations in the analysis. 相似文献
26.
Radical Compatibility with Nonaqueous Electrolytes and Its Impact on an All‐Organic Redox Flow Battery
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Dr. Xiaoliang Wei Dr. Wu Xu Dr. Jinhua Huang Dr. Lu Zhang Dr. Eric Walter Dr. Chad Lawrence Dr. M. Vijayakumar Dr. Wesley A. Henderson Dr. Tianbiao Liu Dr. Lelia Cosimbescu Dr. Bin Li Dr. Vincent Sprenkle Dr. Wei Wang 《Angewandte Chemie (International ed. in English)》2015,54(30):8684-8687
Nonaqueous redox flow batteries hold the promise of achieving higher energy density because of the broader voltage window than aqueous systems, but their current performance is limited by low redox material concentration, cell efficiency, cycling stability, and current density. We report a new nonaqueous all‐organic flow battery based on high concentrations of redox materials, which shows significant, comprehensive improvement in flow battery performance. A mechanistic electron spin resonance study reveals that the choice of supporting electrolytes greatly affects the chemical stability of the charged radical species especially the negative side radical anion, which dominates the cycling stability of these flow cells. This finding not only increases our fundamental understanding of performance degradation in flow batteries using radical‐based redox species, but also offers insights toward rational electrolyte optimization for improving the cycling stability of these flow batteries. 相似文献
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G. R. Vijayakumar 《Graphs and Combinatorics》2011,27(1):143-148
A collection of nontrivial paths in a graph G is called a path pile of G, if every edge of G is on exactly one path and no two paths have a common internal vertex. The least number that can be the cardinality of a
path pile of G is called the path piling number of G. It can be shown that ε ≤ ν + η where ε, ν and η are respectively the size, the order and the path piling number of G. In this note we characterize structurally the class of all graphs for which the equality of this relation holds. 相似文献
29.
Chinnaswamy Thangavel Vijayakumar Rajendran Surender Kumaraswamy Rajakumar Sarfaraz Alam 《Journal of Thermal Analysis and Calorimetry》2011,103(2):693-699
The compound 2,2-bis[4-(4-maleimidophenoxy phenyl)]propane was prepared by the imidization of bisamic acid of 2,2-bis(4-aminophenoxy
phenyl)propane. Various nanoclays were blended with this bismaleimide and thermally cured. The structural characterization
of the synthesized materials and the thermal properties of the bismaleimide and their blends were investigated through FTIR,
1H and 13C NMR, differential scanning calorimetry and thermo gravimetric analysis. Among the various clays investigated, Cloisite 15A
shows strong influence on the cure exotherm of bismaleimide. Introduction of clay mineral into bismaleimide shifts the onset
of curing exotherm to higher temperature and is nearly 40 °C. The thermal stability of the clay loaded cured bismaleimide
increases and the presence of clay particles in the cured bismaleimide matrix enhances the char formation. 相似文献
30.
Vijayakumar S. RamachandraRao Bryan D. Vogt Ravi R. Gupta James J. Watkins 《Journal of Polymer Science.Polymer Physics》2003,41(23):3114-3126
The effect of carbon dioxide (CO2) sorption on the lower critical solution temperatures of deuterated polybutadiene/polyisoprene blends was determined with in situ small‐angle neutron scattering. CO2 was a poor solvent for both polymers and exhibited very weak selectivity between the blend components. The sorption of modest concentrations of CO2, at pressures up to 160 bar, induced phase segregation at temperatures well below the binary‐phase‐separation temperature and caused an increased asymmetry in the lower critical solution temperature curve. The origin of solvent‐induced phase segregation in this weakly interacting polymer blend system was attributed predominantly to an exacerbation of the existing disparity in the compressibility of the components upon CO2 sorption. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3114–3126, 2003 相似文献