Thermodynamics and Fluctuations Far From Equilibrium

Abstract: We review a coherent mesoscopic presentation of thermodynamics and fluctuations far from and near equilibrium, applicable to chemical reactions, energy transfer and transport processes, and electrochemical systems. Both uniform and spatially dependent systems are considered. The focus is on processes leading to and in non‑equilibrium stationary states; on systems with multiple stationary states; and on issues of relative stability of such states. We establish thermodynamic state functions, dependent on the irreversible processes, with simple physical interpretations that yield the work available from these processes and the fluctuations. A variety of experiments are cited that substantiate the theory. The following topics are included: one-variable systems, linear and nonlinear; connection of thermodynamic theory with stochastic theory; multivariable systems; relative stability of different phases; coupled transport processes; experimental determination of thermodynamic and stochastic potentials; dissipation in irreversible processes and nonexistence of extremum theorems; efficiency of oscillatory reactions, including biochemical systems; and fluctuation-dissipation relations.