arXiv subjects

J. P. Badiali

Publications and source records attributed to J. P. Badiali.

24 records · Page 2Linked to original sources

arXiv2005

On the double criticality of fluids adsorbed in disordered porous media

The phase transition of a fluid adsorbed in a heterogeneous system is studied with two simple lattice gas models within the framework of a mean-field theory. Despite the different origin of the heterogeneity (spatial variation of binding energy or fluid coordination numbers), the fluid can undergo two phase transitions if the hosting system is sufficiently heterogeneous. It is clearly shown that such a polymorphism in the confined fluid results from the successive condensations in distinct spatial regions of the host. We have found the precise conditions at which one two phase transitions occur. The insight gained from the present study allows one to understand better some recent puzzling simulation results.

cond-mat.stat-mech↗

arXiv2004

Entropy, time irreversibility and Schroedinger equation in a primarily discrete space-time

In this paper we show that the existence of a primarily discrete space-time may be a fruitful assumption from which we may develop a new approach of statistical thermodynamics in pre-relativistic conditions. The discreetness of space-time structure is determined by a condition that mimics the Heisenberg uncertainty relations and the motion in this space-time model is chosen as simple as possible. From these two assumptions we define a path-entropy that measures the number of closed paths associated with a given energy of the system preparation. This entropy has a dynamical character and depends on the time interval on which we count the paths. We show that it exists an like-equilibrium condition for which the path-entropy corresponds exactly to the usual thermodynamic entropy and, more generally, the usual statistical thermodynamics is reobtained. This result derived without using the Gibbs ensemble method shows that the standard thermodynamics is consistent with a motion that is time-irreversible at a microscopic level. From this change of paradigm it becomes easy to derive a $H-theorem$. A comparison with the traditional Boltzmann approach is presented. We also show how our approach can be implemented in order to describe reversible processes. By considering a process defined simultaneously by initial and final conditions a well defined stochastic process is introduced and we are able to derive a Schroedinger equation, an example of time reversible equation.

quant-ph↗

arXiv2004

Surface rearrangement at complex adsorbate-substrate interfaces

On the basis of the information theory approach we propose a novel statistical scheme for analyzing the evolution of coupled adsorbate-substrate systems, in which the substrate undergoes the adsorbate-induced transformations. A relation between the substrate morphology and the adsorbate thermodynamic state is established. This allows one to estimate the surface structure in terms of incomplete experimental information and the one concerning the adsorbate thermodynamic response to the structural modifications.

cond-mat.stat-mech↗

arXiv2003

Role of structural fluctuations in the insertion into complex host matrices

A coupling of structural and thermodynamic fluctuations in the course of various-type insertion processes is investigated within a combination of Gibbsian statistics and the information theory approach. It is shown that the coupling makes it possible to restore (at least partially) the information, inaccessible from experimental tests. This enables one to make physically reasonable predictions under limited information on the system.

cond-mat.stat-mech↗

arXiv2003

A correlation between the equilibrium and transport properties of intercalation systems

Employing the lattice gas model, combined with the linear elasticity theory, a correlation between the equilibrium and transport properties of intercalated species is investigated. It is shown that the major features of the intercalation isotherms and the concentration dependence of the chemical diffusion coefficient can be well understood in terms of the change of the host volume in the course of intercalation. Theoretical predictions are compared to the experimental observations on PdH_x, Li_xWO_3 and Li-graphite systems.

cond-mat.stat-mech↗

arXiv2003

Thermodynamic non-additivity in disordered systems

It is shown that there is a mapping of the replica approach to disordered systems with finite replica index $n$ on the Tsallis non-extensive statistics, if the average thermodynamic entropy differs from the information entropy for the probability distribution. In the case of incomplete information the entropic index $q=1-n$ is shown to be related to the degree of lost information.

cond-mat.stat-mech↗