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Full-Text Articles in Physics
Dielectric Relaxation Behaviour Of Glycine In Acqueous Solution Medium In The Microwave Frequency Region, Ajaya Kumar Kavala
Dielectric Relaxation Behaviour Of Glycine In Acqueous Solution Medium In The Microwave Frequency Region, Ajaya Kumar Kavala
Mr Ajaya Kumar Kavala
No abstract provided.
Low-Energy Antiphase Boundaries, Degenerate Superstructures, And Phase Stability In Frustrated Fcc Ising Model And Ag-Au Alloys, Nikolai A. Zarkevich, Teck L. Tan, Lin-Lin Wang, Duane D. Johnson
Low-Energy Antiphase Boundaries, Degenerate Superstructures, And Phase Stability In Frustrated Fcc Ising Model And Ag-Au Alloys, Nikolai A. Zarkevich, Teck L. Tan, Lin-Lin Wang, Duane D. Johnson
Duane D. Johnson
An Ising model exhibits zero-energy antiphase boundaries (APBs) and frustration on close-packed face-centered cubic (fcc) and triangular lattices. The frustration results in degenerate structures and chains of long-period superstructures forming a quasicontinuous ground-state “hull” in the formation energy versus composition (c) diagram. In alloys, a nonzero but small APB energy yields a c-dependent reduction in this degeneracy that affects the phase diagram topology and range of the two-phase coexistence. Using density functional theory combined with cluster expansions (CEs), we study Ag-Au alloys as a prototype and find the effective cluster interactions (dominated by nearest-neighbor pairs), predict energetics of millions of …
Grain Growth And Texture Development In Lithium Fluoride Thin Films, Hakkwan Kim, Alexander H. King
Grain Growth And Texture Development In Lithium Fluoride Thin Films, Hakkwan Kim, Alexander H. King
Alexander H. King
We have studied grain-growth and texture development in polycrystalline lithium fluoride thin films using dark-field transmission electron microscopy. We demonstrate that we can isolate the size distribution of 〈111〉 surface normal grains from the overall size distribution, based on simple and plausible assumptions about the texture. The {111} texture formation and surface morphology were also observed by x-ray diffraction and atomic force microscopy, respectively. The grain-size distributions become clearly bimodal as the annealing time increases, and we deduce that the short-time size distributions are also a sum of two overlapping peaks. The smaller grain-size peak in the distribution corresponds to …
Predicting Enthalpies Of Molecular Substances: Application To Libh4, Nikolai A. Zarkevich, Duane D. Johnson
Predicting Enthalpies Of Molecular Substances: Application To Libh4, Nikolai A. Zarkevich, Duane D. Johnson
Duane D. Johnson
For molecular substances exhibiting harmonic and nonharmonic vibrations, we present a first-principles approach to predict enthalpy differences between phases at finite temperatures, including solid-solid and melting. We apply it to the complex hydride LiBH4. Using ab initio molecular dynamics, we predict a structure for the high-T solid phase of lithium borohydride, and we propose an approximation to account for nonharmonic vibrations. We then predict the enthalpy changes for solid-solid transition, melting, and an H-storage reaction, all in agreement with experiment.
Charge Transfer Mechanisms In Electrospinning, Jonathan J. Stanger
Charge Transfer Mechanisms In Electrospinning, Jonathan J. Stanger
Jonathan J Stanger
Electrospinning is a method of producing nano structured material from a polymer solution or melt using high strength electric fields. It is a process that has yet to find extensive industrial application yet shows promise if obstacles such as low rate of production overcome perhaps by more complete theoretical modelling. This work examines the effects of adding an ionic salt to a solution of poly(vinyl alcohol) in water. The direct effect was an increase the charge density and electric current. It was found that an increase in charge density decreases the mass deposition rate and forms a thinner initial jet. …
Morphologies And Kinetics Of A Dewetting Ultrathin Solid Film, Mikhail Khenner
Morphologies And Kinetics Of A Dewetting Ultrathin Solid Film, Mikhail Khenner
Mikhail Khenner
The surface evolution model based on geometric partial differential equation is used to numerically study the kinetics of dewetting and dynamic morphologies for the localized pinhole defect in the surface of the ultrathin solid film with the strongly anisotropic surface energy. Depending on parameters such as the initial depth and width of the pinole, the strength of the attractive substrate potential and the strength of the surface energy anisotropy, the pinhole may either extend to the substrate and thus rupture the film, or evolve to the quasiequilibrium shape while the rest of the film surface undergoes phase separation into a …
Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Mikhail Khenner
Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …