The calculation of solid-fluid equilibrium at high pressure is important in the modeling and design of processes that use supercritical fluids to selectively extract solid solutes. We describe here a new method for reliably computing solid-fluid equilibrium at constant temperature and pressure, or for verifying the nonexistence of a solid-fluid equilibrium state at the given conditions. Difficu...

We study the asymptotic behavior of a one-dimensional, dynamical model of solid-solid elastic transitions in which the phase is determined by an order parameter. The system is composed of two coupled evolution equations, the mechanical equation of elasticity which is hyperbolic and a parabolic equation in the order parameter. Due to the strong coupling and the lack of smoothing in the hyperboli...

a second virial coefficient correlation suitable for two different temperatures ranges, (t*)-2£180 and (t*)-2>180, where t* is rt/dhvap is presented. the equation of state can be calculated for different, complicated non-polar, and slightly polar liquid mixtures at any temperature over the range from ttp to tc and up to high pressures. the latent heat of vaporization and density at the triple p...

We propose a phase field model for solid state dewetting where the surface energy is weakly anisotropic. The evolution is based on the Cahn-Hilliard equation with degenerate mobility and a free boundary condition at the film-substrate contact line. We derive the corresponding sharp interface limit via matched asymptotic analysis involving multiple inner layers. The resulting sharp interface mod...

nano-sized batio3 powders with particular nb concentrations were prepared by rotary- hydrothermal (rh) method. hydrothermal method was used at 180 °c for 5 hours with new ti pressure and the teflon vessel was rotated at a speed of 160 rpm during the hydrothermal reaction. new hydrothermal method was used instead of previous solid state reaction for the system batio3±nb2o3 in high temperature to...

A quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. The initial atomic coherence plays an essential role. At steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser fie...

a simple and sensitive method has been developed for the preconcentration and determination of trace level of co(ii) using uv-vis spectrophotometry. β-cyclodextrin polymer modified with 1-(2-pyridylazo)-2-naphthol (pan) is used for the preconcentration of co(ii) from samples at ph 8.5. the polymer is synthesized and characterized using elemental analysis, ft-ir and sem analysis. the factors aff...

this study aimed to evaluate enamel roughness after adhesive removal using different burs and an er:yag laser.the buccal surfaces of forty human premolars were sealed by two layers of nail varnish, except for a circular area of 3 mm in diameter on the middle third. the enamel surfaces were initially subjected to profilometry analysis and four parameters of surface irregularity (ra, rq, rt and r...

We introduce a method for treating soft modes within the analytical framework of the quasiharmonic equation of state. The corresponding double-well energy-displacement relation is fitted to a functional form that is harmonic in both the lowand high-energy limits. Using density-functional calculations and statistical physics, we apply the quasiharmonic methodology to solid periclase ~MgO!. We pr...

Green’s function, an analytical approach in inhomogeneous linear differential equations, is the impulse response, which is applied for deriving the wave equation solution in composite materials mediums. This paper investigates the study of SH wave’s transmission influenced by concentrated point source disturbance in piezomagnetic material resting over heterogeneous half-space. Green function ap...