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[en] The surface-atom Casimir-Polder-Lifshitz force out of thermal equilibrium is investigated in the framework of macroscopic electrodynamics. Particular attention is devoted to its large distance limit that shows a new, stronger behaviour with respect to the equilibrium case. The frequency shift produced by the surface-atom force on the centre-of-mass oscillations of a harmonically trapped Bose-Einstein condensate and on the Bloch oscillations of an ultra-cold fermionic gas in an optical lattice are discussed for configurations out of thermal equilibrium

[en] The ability of fewest switches surface hopping (FSSH) approach, where the classical degrees of freedom are coupled to an implicit Langevin bath, to establish and maintain an appropriate thermal equilibrium was evaluated in the context of a three site model for electron transfer. The electron transfer model consisted of three coupled diabatic states that each depends harmonically on the collective bath coordinate. This results in three states with increasing energy in the adiabatic representation. The adiabatic populations and distributions of the collective solvent coordinate were monitored during the course of 250 ns FSSH-Langevin (FSSH-L) simulations performed at a broad range of temperatures and for three different nonadiabatic coupling strengths. The agreement between the FSSH-L simulations and numerically exact results for the adiabatic population ratios and solvent coordinate distributions was generally favorable. The FSSH-L method produces a correct Boltzmann distribution of the solvent coordinate on each of the adiabats, but the integrated populations are slightly incorrect because FSSH does not rigorously obey detailed balance. The overall agreement is better at high temperatures and for high nonadiabatic coupling, which agrees with a previously reported analytical and simulation analysis [J. R. Schmidt, P. V. Parandekar, and J. C. Tully, J. Chem. Phys. 129, 044104 (2008)] on a two-level system coupled to a classical bath

[en] We address estimation of temperature for finite quantum systems at thermal equilibrium and show that the Landau bound to precision $\mathrm{\delta <!--\; ??\; -->}{T}^2\propto <!--\; ???\; -->T^2$, originally derived for a classical not too small system being a portion of a large isolated system at thermal equilibrium, may be also achieved by energy measurement in microscopic quantum systems exhibiting vanishing gap as a function of some control parameter. On the contrary, for any quantum system with a non-vanishing gap Δ, precision of any temperature estimator diverges as $\mathrm{\delta <!--\; ??\; -->}{T}^2\gtrsim <!--\; ???\; -->T^4{e}^{\mathrm{\Delta <!--\; ??\; -->}/T}$. (letter)

[en] The effect of a radially bounding wall on a magnetically confined single-species plasma near thermal equilibrium is considered. Solutions to the like-particle collisional transport equation are obtained; the boundary conditions at the wall follow from simple physical considerations. Integral constraints on the plasma evolution imply that only a fraction of the plasma can ever be lost to the wall. Analytic estimates and numerical solutions give the scaled wall flux in terms of the unperturbed equilibrium density at the radius of the wall

[en] Computer Simulation has made it possible to solve highly-nonlinear, unpredictable interactions in a non-equilibrium, unstable open system. As a result, dark areas of Science, unrevealed by the conventional mathematical methodology, become shed light on. Discovery of orderliness or regularity, in seemingly complex behaviors, is an attractive, challenging theme in Science. It will be more challenging if some unified rules or laws exist in creating orderliness beyond hierarchy in a system or beyond different systems. Plasma is one typical system full of such complex behaviors. Examples of computer simulations are presented with a hope that readers would grasp some idea of this challenging approach to 'Complexity.' (author)

[en] This problem is concerned with the magnetohydrodynamic oscillatory motion of Rivlin-Erickson fluid between two co-axial circular cylinders both which execute longitudinal oscillation in their own plane. The amplitudes of the frequency have been taken different for the cylinders. The effect of porosity of medium on velocity is obtained and discussed. (author)

[en] In this work we show that tending to thermal equilibrium in one system, at least in certain cases, is associated with the coherent dynamical evolution of this system in interaction with another identical system. The temperature varying effect with time is manifestly shown in our analyses

[en] The charged particle system's energy level separation in the vertical direction of the magnetic field is considered, according to Boltzmann distribution. Several equations are obtained. The effects are obvious under the condition of low temperature and high intensity magnetic field. Several equations of plasma MHD are corrected

[en] Mechanisms of locomotion in microscopic systems are of great interest not only for technological applications but also for the sake of understanding, and potentially harnessing, processes far from thermal equilibrium. Downscaling is a particular challenge and has led to a number of interesting concepts, including thermal ratchet systems and asymmetric swimmers. Here we present a granular ratchet system employing a particularly robust mechanism that can be implemented in various settings. The system consists of wetted spheres of different sizes that adhere to each other, and are subject to a symmetric oscillating, zero average external force field. An inherent asymmetry in the mutual force network leads to force rectification and hence to locomotion. We present a simple model that accounts for the observed behaviour, underscores its robustness and suggests a potential scalability of the concept.