 According to Glansdorff and Prigogine (1971, page 15), in general, these principles apply only to systems that can be described by thermodynamical variables, in which dissipative processes dominate by excluding large deviations from statistical equilibrium.The thermodynamical variables are defined subject to the kinematical requirement of local thermodynamic equilibrium.This means that collisions between molecules are so frequent that chemical and radiative processes do not disrupt the local Maxwell-Boltzmann distribution of molecular velocities.