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The effects of material interface curvature on deflagration of a homogeneous solid energetic material (EM) is studied in a limit when the radius of curvature is much larger than the deflagration front thickness. Under the assumption of quasi-steady burning, a method of matched asymptotics is employed do derive first-order curvature corrections to the mass flux across the gas-solid interface as well as to the interface temperature. As an illustration, a problem of quasi-steady spherical particle deflagration is solved numerically and the simulation results are used to verify those obtained through asymptotic analysis. An algorithm for a fully-coupled unsteady solver suitable for EM deflagration simulation is presented. Numerical solution of the unsteady spherical particle deflagration is used to show that the assumption of quasi-steady deflagration is valid. [ABSTRACT FROM AUTHOR]

We have modeled the electrical properties of three magnetotunnel junctions (MTJs) using a density functional theory (DFT), non-equilibrium Green's functions (NEGFs) based commercial code. We find results similar to those in the literature, and propose investigations into the effects of perturbations to the exact positions of the atoms in these structures. [ABSTRACT FROM AUTHOR]

The article focuses on a study involving liquid crystal interfaces. The author revealed that the Bristol project focused on molecular orientation at the free surface of molecular fluids. He also stressed that the theoretical investigation on surface structure of liquid crystals used molecular cylindrical symmetry as its starting point.

The compatibility of different approximations to the Helmholtz free energy F is analysed in order to provide the consistent definition of the order parameters for liquid crystalline phases. In particular the diagrammatic expansion theory is compared to the weighted, also modified weighted, density approximations. The weight function w is shown to be proportional to the Mayer function. The explicit form of the weight function for the system of non-uniaxial polar molecules is given and the interaction terms of the polar and orientational order parameters in the free energy expansion are discussed. [ABSTRACT FROM AUTHOR]

The nematic-isotropic phase transitions in mixtures of rod-like and disc-like molecules are studied by a mean field theory. We consider both attraction and hard-core repulsion for the model molecules, thermotropic phase transitions are found from the isotropic to one of the two types of uniaxially symmetric nematic phases: optically positive N+ and negative N-. On the other hand, biaxially symmetric nematic phase is shown to be always less stable than the uniaxial phase. We predict that re-entrant phase transition occur for the lyotropic system. [ABSTRACT FROM AUTHOR]

We theoretically study interfacial properties between two coexisting phases in mixtures of a flexible polymer and a low molecular weight liquid crystal. By numerically solving Eular equations for concentration and orientation order parameters, we calculate order parameter profiles and interfacial tensions between coexisting nematic-isotopic and isotropic-isotropic phases at equilibrium. [ABSTRACT FROM AUTHOR]

The general formulation of double refraction or internal double reflection with different directions of propagation vector and wave vector in a uniaxial crystal is analysed in terms of Huygens' principle. Then double refraction and double reflection along the sequential interfaces in a crystal are discussed. On this basis, a configuration of electro-optic 1× N optical switch with modulators and birefringent crystal slabs integrated in a single block of crystal is suggested, which is simple and compact in construction, low in loss and insensitive to environment. Finally, calculations are given which lead to a proposed design of a 1×4 switch. [ABSTRACT FROM AUTHOR]