Thermal instability driven by radiation pressure might be relevant for intrinsically bright accreting sources. The most promising candidate where this instability seems to be at work is one of the two known galactic superluminal sources, GRS 1915+105 (Belloni et al. 1997). In spite of being of relevance, this scenario has not yet been confirmed by proper time-dependent modelling. Non-linear tim...

This paper is concerned with the analysis of the stability of the Vlasov-PoissonFokker-Planck system with respect to the physical constants. If the scaled thermal mean free path converges to zero and the scaled thermal velocity remains constant, then a hyperbolic limit or equivalently a high-field limit equation is obtained for the mass density. The passage to the limit as well as the existence...

The design and fabrication of nanostructured materials to control both thermal and electrical properties are demonstrated for high-performance thermoelectric conversion. We have focused on silicon (Si) because it is an environmentally friendly and ubiquitous element. High bulk thermal conductivity of Si limits its potential as a thermoelectric material. The thermal conductivity of Si has been r...

For the past few years, nanoscale structures have been proposed and investigated experimentally for their enhanced thermoelectric properties over bulk materials. These structures offer several advantages: 1) increased local density of states, which can improve the Seebeck coefficient and 2) reduced thermal transport due to phonon confinement and increased scattering. Recently, nanocrystalline c...

Original scientific paper Nondimensional expressions for the work output, thermal efficiency, heat input, and entropy generation number in the Brayton cycle with a recuperator are given as functions of seven input parameters: pressure ratio, temperature ratio, recuperator effectiveness, turbine and compressor isentropic efficiencies, nondimensional pressure drop in the combustor and recuperator...

In this work, the strontium-doped lanthanum manganite- a ceramic material- used as cathode in solid oxide fuel cells. An impression of grinding time on the structural and thermal properties of Sr-doped LaMnO3 system with La1-xSrxMnO3 (x=0.2) stoichiometric ratio was investigated. The nano crystallite LSM powder with cubic structure was prepared by varying the milling time of planetary monomill ...

a new correlation function for the calculation of viscosity for five typical supercritical gases is presented using the rainwater-friend and modified enskog theory. it is shown that by using accurate value for the thermal pressure and co-volume in the modified enskog theory, this correlation function is suitable for calculation of the viscosity of supercritical gases, without any density and te...

The paper deals with devising the combination of fuzzy inference systems (FIS) and neural networks called the adaptive network fuzzy inference system (ANFIS) to determine the forming limit diagram (FLD). In this paper, FLDs are determined experimentally for two grades of low carbon steel sheets using out-of-plane (dome) formability test. The effect of different parameters such as work hardening...

this work presents a numerical analysis of entropy generation in γ-shaped enclosure that was submitted to the natural convection process using a simple thermal lattice boltzmann method (tlbm) with the boussinesq approximation.  a 2d thermal lattice boltzmann method with 9 velocities, d2q9, is used to solve the thermal flow problem. the simulations are performed at a constant prandtl number (pr ...