Showing papers on "Gibbs–Duhem equation published in 1992"

Gibbs-Duhem and Clausius-Clapeyron type equations for elastically stressed crystals

Abstract: General thermodynamic expressions relating the intensive variables in homogeneously deformed, nonhydrostatically stressed crystals are derived for both open and closed systems (Gibbs-Duhem equation). These equations are then combined with the equilibrium conditions to write Clausius-Clapeyron type equations for crystal-gas and multiphase crystalline systems. As the components of the elastic deformation (strain) can be either thermodynamic intensive variables or densities, depending upon the imposed boundary conditions and system geometry, various Gibbs-Duhem type equations exist; the equation to use depends on the problem under consideration.

Gibbs Ensemble Calculations with an Equation of State: An Application to Vapor-Liquid Equilibria

Abstract: A new modification of the Gibbs ensemble Monte Carlo computer simulation method for fluid phase equilibria is described. The modification is based on a thermodynamic model for the vapor phase, and uses an equation of state to account for the weak interactions between the vapor phase molecules. Reductions in the computational time by 30–40% as compared to the original Gibbs ensemble method are obtained. The algorithm is applied to Lennard-Jones - (12,6) fluids and their mixtures and the results are in good agreement with results obtained from simulations using the full Gibbs ensemble method.

Thermodynamic formulae of homogeneous nucleation

Abstract: Following Gibbs' method, interfacial thermodynamics is extended to systems with small fluid nuclei which may not possess homogeneous bulk properties even at their centers Physical meanings of the bulk and the interface terms in the Gibbs formula of the reversible work to form a critical nucleus are clarified by analyzing the thought process due to Gibbs Then, interfacial thermodynamics is further extended to systems with noncritical liquid clusters in vapor in order to establish the valid procedure, in the commonly used method, to determine the size and the composition of a critical nucleus In those works, however, difficult problem of unifying the Lothe-Pound theory and the interfacial thermodynamics is left unresolved

Corrigendum to 'Pore shape evolution by solution transfer: thermodynamics and mechanics'* by T. Reuschl6, L. Trotignon and

Abstract: The chemical potential of a component of the solid in solution is given by the equilibrium condition between the stressed solid and its solution. This condition was first established by Gibbs (1877) for a plane interface and then generalized to any curved interface. It was rederived later by Lehner & Bataille (1985) and Mullins & Sekerka (1985). Gibbs (1877) chose to have the solid and the fluid phases enclosed within rigid walls, thus preventing any exchange of mechanical work between the system (solid + fluid) and the environment. However, in the experience described in our reference paper, samples are subjected to constant stress conditions, which induce a deformation of the samples and thus an exchange of work with the environment. One may wonder if Gibbs’ classical equation is still valid under these conditions which are the usual conditions for creep of rocks by pressure solution. We tried to give an answer to this question by using an approach similar to the Griffith’s crack approach. Our derivation led us to the conclusion that Gibbs’ equation had to be modified to take into account the deformability of the solid. We thus proposed to add an elastic energy term to the classical Gibbs’ equation. The question arose as to whether or not Gibbs’ and Griffith’s approaches are compatible. In this corrigendum we want to correct our previous derivation by showing that it contained some omissions leading to an incorrect conclusion. In the reference paper, we proposed to write the variation AU of the internal energy of the system (solid+fluid) as follows (equation 9 of the reference paper): AU = AQ + AW = AU, + AU, + (uf - us) 6n (9)