The law of action and reaction for the effective force in a nonequilibrium colloidal system

We study a nonequilibrium Langevin many-body system containing two 'test' particles and many 'background' particles. The test particles are spatially confined by a harmonic potential, and the background particles are driven by an external driving force. Employing numerical simulations of the model, we formulate an effective description of the two test particles in a nonequilibrium steady state. In particular, we investigate several different definitions of the effective force acting between the test particles. We find that the law of action and reaction does not hold for the total mechanical force exerted by the background particles, but that it does hold for the thermodynamic force defined operationally on the basis of an idea used to extend the first law of thermodynamics to nonequilibrium steady states.Comment: 13 page

Derivation of Non-isotropic Phase Equations from a General Reaction-Diffusion Equation

A non-isotropic version of phase equations such as the Burgers equation, the K-dV-Burgers equation, the Kuramoto-Sivashinsky equation and the Benney equation in the three-dimensional space is systematically derived from a general reaction-diffusion system by means of the renormalization group method.Comment: 21pages,no figure

Statistical mechanics of glass transition in lattice molecule models

Lattice molecule models are proposed in order to study statistical mechanics of glass transition in finite dimensions. Molecules in the models are represented by hard Wang tiles and their density is controlled by a chemical potential. An infinite series of irregular ground states are constructed theoretically. By defining a glass order parameter as a collection of the overlap with each ground state, a thermodynamic transition to a glass phase is found in a stratified Wang tiles model on a cubic lattice.Comment: 18 pages, 8 figure

When Individuality Becomes a Plight in Richard Wright’s Black Boy and Albert Camus’ The Stranger

This paper portrays both Richard Wright's and Albert Camus' depiction, within Black Boy and The Outsider, of man's struggle against their biased societies. More precisely, it sheds light on the state of Meursault and Richard as individuals seeking individuality in the face of their rigid social milieu. Making distinctiveness their main purpose, each protagonist approaches it differently. While Meursault alienates himself, neglects his society, defies it, and dies for his belief in honesty as well as the universal absurdity of the society, Richard decides firmly to leave his racist community, attempts to adapt himself to his society, alienates himself, defies all sorts of authority, uses words and stories to empower him, and heads to the North where he believes he can have a full meaning of selfhood. Key words: Absurdity; Alienation; The individual; Society; Individuality; Honesty; Racism; Oppression; Struggle Résumé: Cet article décrit la représentation de Richard Wright et Albert Camus, au sein de Black Boy et The Outsider, la lutte des étre humains contre leurs sociétés biaisée. Plus précisément, il considere l'état de Meursault et Richard en tant que des personnes qui cherchent l'individualité dans de leur milieu social rigide. Considéré la spécificité comme leur but principal, chacun des protagonistes l'approche différemment. Pendant que, Meursault s'aliène, néglige sa société, la défie, et meurt pour preserver son honnêteté, Richard décide fermement de quitter sa communauté raciste, s'adapter artificiellement à sa société, s'alièner, défier toutes les sortes de pouvoir, et se diriger vers le Nord où il croit qu'il peut avoir un sens d' individualité. Mots-clés: Absurdité; L'aliénation; L'individu; La Société; L'individualité; L'honnêteté; Le Racisme; L'oppression; La Lutt

Equilibrium Chemical Engines

An equilibrium reversible cycle with a certain engine to transduce the energy of any chemical reaction into mechanical energy is proposed. The efficiency for chemical energy transduction is also defined so as to be compared with Carnot efficiency. Relevance to the study of protein motors is discussed. KEYWORDS: Chemical thermodynamics, Engine, Efficiency, Molecular machine.Comment: 5 pages, late

Energetics of Open Systems and Chemical Potential From Micro-Dynamics Viewpoints

We present the energetic aspect of open systems which may exchange particles with their environments. Our attention shall be paid to the scale that the motion of the particles is described by the classical Langevin dynamics. Along a particular realization of the stochastic process, we study the energy transfer into the open system from the environments. We are able to clarify how much energy each particle carries when it enters or leaves the system. On the other hand, the chemical potential should be considered as the concept in macro scale, which is relevant to the free energy potential with respect to the number of particles. Keywords: open systems, stochastic energetics, chemical potentialComment: 7 pages, 1 figur

Exact transformation of a Langevin equation to a fluctuating response equation

We demonstrate that a Langevin equation that describes the motion of a Brownian particle under non-equilibrium conditions can be exactly transformed to a special equation that explicitly exhibits the response of the velocity to a time dependent perturbation. This transformation is constructed on the basis of an operator formulation originally used in nonlinear perturbation theory for differential equations by extending it to stochastic analysis. We find that the obtained expression is useful for the calculation of fundamental quantities of the system, and that it provides a physical basis for the decomposition of the forces in the Langevin description into effective driving, dissipative, and random forces in a large-scale description.Comment: 14 pages, to appear in J. Phys. A: Math. Ge

Effects of Surface Soil Removal on Dynamics of Dissolved Inorganic Nitrogen in a Snow-Dominated Forest

To clarify the effect of vegetation and surface soil removal on dissolved inorganic nitrogen (N) dynamics in a snow-dominated forest soil in northern Japan, the seasonal fluctuation of N concentrations in soil solution and the annual flux of N in soil were investigated at a treated site (in which surface soil, including understory vegetation and organic and A horizons, was removed) and control sites from July 1998 to June 2000. Nitrate (NO3–) concentration in soil solution at the treated site was significantly higher than that of the control in the no-snow period, and it was decreased by dilution from melting snow. The annual net outputs of NO3– from soil at the treated site and control sites were 257 and –12 mmol m–2 year–1, and about 57% of the net output at the treated site occurred during the snowmelt period. NO3– was transported from the upper level to the lower level of soil via water movement during late autumn and winter, and it was retained in soil and leached by melt water in early spring. Removing vegetation and surface soil resulted in an increase in NO3– concentration of soil solution, and snowmelt strongly affected the NO3– leaching from treated soil and the NO3– restoration process in a snow-dominated region