THE RATE OF ENTROPY PRODUCTION AS AN EVOLUTION CRITERION IN CHEMICAL-SYSTEMS .1. OSCILLATING REACTIONS

Three chemicals oscillating models were chosen to be studied: Autocata lator, Brusselator and Oregonator. All of them exhibit an exotic behav ior during the evolution of its intermediary species, in the form of t emporal or spatial periodic oscillations (under determined conditions) . Models were numerically integrated, by using Gear's algorithm. It wa s shown that an evolutive criterion for such systems could be sought f rom the eulerian derivative of the rate of entropy production respect to time as a function of the control parameters of the system. Thus, d uring evolution, such chemical systems, far from the thermodynamic equ ilibrium, go through stationary states, qualitatively different, as a result of Hop's bifurcation. This gives rise to self-organization and the rate of entropy production in each state is decreased in compariso n with the previous one.