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871.
La0.5Sr0.5CoO3-yttria-stabilized zirconia (LSCO-YSZ) composite cathode for solid oxide fuel cell (SOFC) has been fabricated by wet impregnation method. Nitrate precursors of La, Sr, and Co have been impregnated into the pre-sintered porous YSZ matrix, which is converted into LSCO phase after calcination at 850 °C in the presence of glycine as confirmed from X-ray diffraction. LSCO of 5, 7, and 10 wt% impregnated porous YSZ have been electrochemically characterized using 2-probe AC conductivity method. Maximum ionic conductivity of 0.27 S/cm at 800 °C and activation energy of 0.15 eV between 600 and 800 °C have been observed for 10 wt% LSCO-YSZ cathode. Area-specific resistance of 1.01 Ω cm2 at 800 °C is estimated for the electrolyte-supported half-cell (10 wt% LSCO-YSZ/YSZ). After testing the LSCO-YSZ cathode matrix, the electrolyte-supported full cell (10 wt% LSCO-YSZ/YSZ/NiO-YSZ) has been tested and produced maximum power density 51.12 mW/cm2 (109.38 mA/cm2) at 800 °C. The electrolyte-supported full cell exhibited 6 Ω cm2 electrode polarization at 800 °C in H2, which is in higher side leading to low performance. LSCO-YSZ/YSZ/NiO-YSZ SOFC found to give stable performance up to 2 h and scanning electron microscopy analysis has been carried out before and after cell testing to assess the morphological changes. 相似文献
872.
We have measured the electroluminescence (EL) and carrier lifetime characteristics in InGaN/Sapphire purple light emitting diode (LED), namely, UV3TZ-405-30 in a temperature range from 350 to 120 K and have compared them with those of a similar LED (UV3TZ-395-15) but with different Indium concentration, measured earlier. While it is found that for the present device the EL intensity decreases drastically with lowering of temperature after reaching a maximum (99%) at 228 K, this is markedly different from the previous device where intensity continues to increase monotonically till lowest temperature. This qualitatively distinct temperature dependence indicates difference in nature of localisation of carriers in the multiple quantum wells for varying Indium content in the two devices. The light–current–temperature data have been analysed in terms of the semiconductor rate equations to determine different optoelectronic properties. Next, estimating the ideality factor from the current–voltage (I–V) measurements, the effective carrier lifetime has been evaluated from the open circuit voltage decay process. Using the above measurements, the temperature dependence of the internal quantum efficiency of the device has been calculated and it is found to attain a maximum value of 99.88% at 228 K. Unlike all previous calculations, a unique feature of the present approach has been to include the effect of temperature dependence of the radiative recombination coefficient (B) in the rate equation analysis. Finally, a comparative study of the temperature dependence of the different optoelectronic properties of both devices is presented with and without this effect. 相似文献
873.
Abhishek?Saha Saptarshi?Basu Ranganathan?KumarEmail author 《Experiments in fluids》2012,52(3):795-807
Preferential accumulation and agglomeration kinetics of nanoparticles suspended in an acoustically levitated water droplet
under radiative heating has been studied. Particle image velocimetry performed to map the internal flow field shows a single
cell recirculation with increasing strength for decreasing viscosities. Infrared thermography and high speed imaging show
details of the heating process for various concentrations of nanosilica droplets. Initial stage of heating is marked by fast
vaporization of liquid and sharp temperature rise. Following this stage, aggregation of nanoparticles is seen resulting in
various structure formations. At low concentrations, a bowl structure of the droplet is dominant, maintained at a constant
temperature. At high concentrations, viscosity of the solution increases, leading to rotation about the levitator axis due
to the dominance of centrifugal motion. Such complex fluid motion inside the droplet due to acoustic streaming eventually
results in the formation of a ring structure. This horizontal ring eventually reorients itself due to an imbalance of acoustic
forces on the ring, exposing larger area for laser absorption and subsequent sharp temperature rise. 相似文献
874.
M. Haridas S. Srivastava J. K. Basu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(1):93-100
Optical properties of polymer capped gold nanoparticles of various sizes (diameter 3–6 nm) have been studied. We present a
new scheme to extract size dependent variation of total dielectric function of gold nanoparticles from measured UV-Vis absorption
data. The new scheme can also be used, in principle, for other related systems as well. We show how quantum effect, surface
atomic co-ordination and polymer-nanoparticle interface morphology leads to a systematic variation in interband part of the
dielectric function of gold nanoparticles, obtained from the analysis using our new scheme. Careful analysis enables identification
of the possible changes to the electronic band structure in such nanoparticles. 相似文献
875.
Smita Basu Archana Mizar Tushar S. Basu Baul Eleonora Rivarola 《Hyperfine Interactions》2008,185(1-3):95-102
Several organotin(IV) compounds, viz., diorganotin(IV) compounds of the types Ph2SnLH (monomer), nBu2SnLH·OH2 (monomer), [Me2SnLH·OH2]2 (centrosymmetric dimer), [nBu2SnLH]3 (cyclic trinuclear), [Ph2SnLH] n (polymer), {[nBu2Sn(LH)]2O}2 (centrosymmetric tetranuclear), dinuclear di-/tri-mixed organotin(IV) compounds Ph2SnLH·Ph3SnCl (monomer) and triorganotin(IV) compounds of the types [Bz3SnLH]2 (centrosymmetric dimer) and [Me3SnL1H] n (Polymer) (LH = Schiff base carboxylate) have been studied in the solid state at liquid nitrogen temperature using 119Sn Mössbauer spectroscopy. The tin coordination geometry of the compounds determined from crystallography was correlated with the 119Sn Mössbauer results. 相似文献
876.
We present unpolarized and polarized neutron reflectometry data on Fe/Au multilayer sample for characterizing the layer structure and magnetic moment density profile. Fe/Au multilayer shows strong spin-dependent scattering at interfaces, making it a prospective GMR material. Fe/Au multilayer with bilayer thickness of 130 Å was grown on Si substrate by RF magnetron sputtering technique. Unpolarized neutron reflectivity measurement yields nuclear scattering length density profile. The magnetic scattering length density profile has been obtained from polarized neutron reflectivity measurements. 相似文献
877.
We report the density depth profile of an as-deposited Ni film and density profile for the same film after controlled electrochemical
corrosion by chloride ions, measured by unpolarized neutron reflectometry. The neutron reflectometry measurement of the film
after corrosion shows density degradation along the thickness of the film. The density profile as a function of depth, maps
the growth of pitting and void networks due to corrosion. The profile after corrosion shows an interesting peaking nature.
相似文献
878.
Chuan Li Zhe Jia Arghya Chakravorty Swagata Pahari Yunhui Peng Sankar Basu Mahesh Koirala Shailesh Kumar Panday Marharyta Petukh Lin Li Emil Alexov 《Journal of computational chemistry》2019,40(28):2502-2508
Electrostatic potential, energies, and forces affect virtually any process in molecular biology, however, computing these quantities is a difficult task due to irregularly shaped macromolecules and the presence of water. Here, we report a new edition of the popular software package DelPhi along with describing its functionalities. The new DelPhi is a C++ object-oriented package supporting various levels of multiprocessing and memory distribution. It is demonstrated that multiprocessing results in significant improvement of computational time. Furthermore, for computations requiring large grid size (large macromolecular assemblages), the approach of memory distribution is shown to reduce the requirement of RAM and thus permitting large-scale modeling to be done on Linux clusters with moderate architecture. The new release comes with new features, whose functionalities and applications are described as well. © 2019 The Authors. Journal of Computational Chemistry published by Wiley Periodicals, Inc. 相似文献
879.
Chirantan Gayen Upashi Goswami Kasturi Gogoi Srestha Basu Anumita Paul 《Chemphyschem》2019,20(7):953-958
Herein, we report the construction of intracellular logic operations using luminescent histidine stabilized gold nanoclusters (His Au NCs). The luminescence intensity of His Au NCs was found to be significantly enhanced following interaction with zinc ions, owing to “Crystallization induced emission enhancement”. Further, the luminescence intensity of His Au NCs was found to be effectively quenched in presence of sulphide ions, owing to transformation of emissive His Au NCs to non-emissive gold nanoparticles. Thus, the collective and individual effects of zinc ions and sulphide ions causing significant variation in the luminescence intensity of His Au NCs, were used as input parameters for construction of intracellular logic operations such as Tri state buffer, “on-off” switch and INHIBIT gate within mammalian cells. 相似文献
880.
In this paper a finite element (FE) based unitcell model has been devised with periodic boundary conditions to calculate the effective tan δ of a composite as a function of frequency. Using this method, it is demonstrated that the tan δ of the nano-composite manifests important information about the extent and properties of the interphase region that surrounds each nano-particle. Thus we imply that tan δ measurements provide a simple yet useful experimental tool to understand more about the interphase. However, severe agglomeration or wide size distribution of the nano-particles may introduce errors in measurement. 相似文献