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Molecular dynamic (MD) simulation is performed using a secondneighbor Finnis-Sinclair (FS) potential to study structural and atomic mass transport properties of molybdenum in the liquid phase for a temperature (T) range of 3100 to 3800 K. The Computed results for the pair correlation function, structure factor, and coordination number are discussed with similar findings. Transport coefficients like viscosity and self-diffusion coefficient follow Arrhenius law, which estimates activation energy between 1.34 to 1.62 eV. The discrepancy in computed densities and other properties beyond 3800 K is discussed, given the nature of interaction potentials and binding in liquid molybdenum. It is shown that EAM, MEAM, and FS potentials show analogous repulsive character and therefore give comparable results for structural properties. However, the attractive part of the interaction potential, which determines the binding in molybdenum is responsible for the difference in various high-T physical properties reported in the study. The sensitivity of physical properties on the attractive part of the interaction potential thus demands to incorporate the effect of temperature dependency of electron density-of-state (e- dos) and angular forces into the interaction for a proper account of the binding in liquid molybdenum. [ABSTRACT FROM AUTHOR]

The role of phonons is important in accounting various properties of materials. Crystal potential being an anharmonic function of volume, variations are seen in phonon derived properties with a change in volume. In the present work, we employ an approximate technique of expanding phonon frequencies using Taylor series expansion upto second-order in volume to calculate the volume dependent phonon frequencies of CaO in B1 and B2 phases. Equilibrium properties are obtained by fitting Murnaghan EoS to first principles DFT based results, however. The mode Grüneisen parameter and concavity parameter are computed with the help of present ab initio phonon frequencies for both the phases. Their volume dependence are estimated analytically using the proposed scheme. We find that phonon frequencies increase by decreasing volume. Analytically calculated volume dependent phonon frequencies are compared in reasonable agreement with the frequencies obtained directly using DFT for B1-phase. Thus, the present r-space computational scheme of deriving volume dependent phonon frequency proves to be an alternative to overcome lengthy phonon calculations. [ABSTRACT FROM AUTHOR]

Accurate assessment of electrical transport for heavy polyvalent metals pause challenge due to complex electronic band structure, where s-wave scattering theory due to Ziman is failed. Improving schemes like t-matrix resistivity and self-consistent approach are proposed. In the present study, we employ selfconsistent approach to compute electrical resistivity (ρ) in liquid Bi and Sb at different temperatures (T). Structural input is estimated through charged hard-sphere reference system. Electron-ion interaction is modelled by modified empty-core pseudopotential including electron exchange and correlation effects. Since only two parameters are independent, as the core radius RC (= 0.51 RaZ-1/3) is a theoretical input, we have tuned, once and for all, the single parameter to find ρ at melting temperature. The same set of parameters is used to deduce high-T resistivity, thermal conductivity and thermo-electric power. Overall good agreement is observed for transport properties for both metals. The present fitting scheme and so deduced results are discussed in comparison with other findings. [ABSTRACT FROM AUTHOR]

The present investigation focussed on the development of a novel strategy to enhance the bioavailability of risedronate sodium, which has poor and erratic absorption. Nanosponges were statistically developed by full 3² factorial design using Design of Experiment software considering concentration of polymer and stabilizer as independent variables and particle size and entrapment efficiency as experimental responses by utilizing the modified quasi-emulsion solvent diffusion technique. Optimized formulation showed 67.27± 1.05 % entrapment efficiency, 155.8±2.17 nm particle size and -35.4 mV of zeta potential. The data from in vitro release study showed burst release for initial 2 h followed by slow and sustained release up to 24 h, which followed a diffusion-controlled release mechanism by the Higuchi model. Scanning electron microscopy study showed uniformly discrete spherical particles with porous surface without any agglomeration. Stability study demonstrated no significant changes in particle size, entrapment efficiency and in vitro release, which indicated that the nanosponge formulation was stable. In conclusion, it appeared that the nanosponges were a suitable nanocarrier system that could play a significant role in improving osteoporotic condition. [ABSTRACT FROM AUTHOR]

Electron backscattered diffraction (EBSD) maps acquired in the diffusion zone of aluminised Super 304H steel samples showed that a phase change and associated grain growth phenomena had occurred during high temperature aging in flowing steam environments. This phase transformation could have a significant influence on reducing the oxidation resistance and mechanical stability of the aluminised layer at high temperatures. Scanning electron microscopy combined with energy dispersive X-ray spectroscopy and EBSD mapping provides a valuable insight into microstructural changes occurring in coated alloy systems during high temperature aging processes. [ABSTRACT FROM AUTHOR]