10 Facts About Non-equilibrium thermodynamics

Non-equilibrium thermodynamics is a branch of thermodynamics that deals with physical systems that are not in thermodynamic equilibrium but can be described in terms of macroscopic quantities that represent an extrapolation of the variables used to specify the system in thermodynamic equilibrium.

Non-equilibrium thermodynamics is concerned with transport processes and with the rates of chemical reactions.

Equilibrium Non-equilibrium thermodynamics restricts its considerations to processes that have initial and final states of thermodynamic equilibrium; the time-courses of processes are deliberately ignored.

Consequently, equilibrium thermodynamics allows processes that pass through states far from thermodynamic equilibrium, that cannot be described even by the variables admitted for non-equilibrium thermodynamics, such as time rates of change of temperature and pressure.

Non-equilibrium thermodynamics is a work in progress, not an established edifice.

Some concepts of particular importance for non-equilibrium thermodynamics include time rate of dissipation of energy, time rate of entropy production, thermodynamic fields, dissipative structure, and non-linear dynamical structure.

One initial approach to non-equilibrium thermodynamics is sometimes called 'classical irreversible thermodynamics'.

In some writings, it is assumed that the intensive variables of equilibrium Non-equilibrium thermodynamics are sufficient as the independent variables for the task ; in particular, local flow intensive variables are not admitted as independent variables; local flows are considered as dependent on quasi-static local intensive variables.

In Non-equilibrium thermodynamics one is often interested in a stationary state of a process, allowing that the stationary state include the occurrence of unpredictable and experimentally unreproducible fluctuations in the state of the system.

Non-equilibrium thermodynamics defined 'local thermodynamic equilibrium' in a 'cell' by requiring that it macroscopically absorb and spontaneously emit radiation as if it were in radiative equilibrium in a cavity at the temperature of the matter of the 'cell'.