This paper examines some experimental evidence for coupling between particle and energy anspor t in tokamak plasmas and presents analytical and numerical investigations of this type of transport. This coupling generally leads to discrepancies between the effective thermal diffusivities inferred from analyses of power balance and perturbation measurements. Such discrepancies have been observed e...

The fragmentation process of primordial-gas cores during prestellar collapse is studied using three-dimensional nested-grid hydrodynamics. Starting from the initial central number density of nc ∼ 10 cm, we follow the evolution of rotating spherical cores up to the stellar density nc ≃ 10 cm. An initial condition of the cores is specified by three parameters: the ratios of the rotation and therm...

Real-time perturbation theory is formulated for complex scalar fields away from thermal equilibrium in such a way that dissipative effects arising from the absorptive parts of loop diagrams are approximately resummed into the unperturbed propagators. Low order calculations of physical quantities then involve quasiparticle occupation numbers which evolve with the changing state of the field syst...

2014 We study the effect of the coupling between front deformation and solutal convection on the position of the bifurcation from the planar quiescent state of a dilute binary alloy submitted to directional solidification. We set up a perturbation treatment of the coupling between the « bare » (Mullins-Sekerka and solutal convective) bifurcations. We show that the shift of the Mullins-Sekerka b...

Abstract. In this paper we present a model for computing thermal stress inside a crystal with facets. Using a systematical perturbation analysis, a semi-analytical thermal stress solution is obtained for constrained directional growth with small lateral heat flux. Our solution can be applied to crystals grown by various growth techniques such as the Czochralski method. The semianalytical nature...

INTRODUCTION: Lipid theories of anesthesia implicate perturbation of membrane lipids as the locus for acute anesthetic action. [1] Chronic exposure to alcohols and anesthetics induces an adaptive response in membrane phospholipids that confers resistance to many of the acute actions of alcohols and anesthetics. [2] We have proposed a colligative thermodynamic reformulation of the Meyer-Overton ...

The aim of this work is to apply the homotopy perturbation method and homotopy analysis method to the problem of thermal explosion in a flammable gas mixture with the addition of volatile fuel droplets. The system of equations that describes the effects of heating, evaporation, and combustion of fuel in a polydisperse spray is simplified. Both convective and radiative heating of droplets is tak...

In this article, we are interested in the behaviour of a single ferromagnetic mono-domain particle submitted to an external field with a stochastic perturbation. This model is the first step toward the mathematical understanding of thermal effects on a ferromagnet. In a first part, we present the stochastic model and prove that the associated stochastic differential equation is well defined. Th...

Thermal perturbation of mantle phase relations in subduction zones gives rise to significant buoyancy anomalies. Finite element modeling of stresses arising from these anomalies reveals transition from principal tension to compression near ∼400 km depth, down-dip compression over ∼400-690 km (peaking at ∼550 km), and transition to rapidly fading tension below ∼690 km. Such features, even when c...