entropientropiflödespar

Entropientropiflödespar is a theoretical construct in the study of non-equilibrium thermodynamics and information theory, describing the coupled pair that characterizes entropy behavior in a system. The term combines the Swedish words for entropy (entropi) and flow pair (flödespar), and is used to express how entropy is generated internally and how it is exchanged with the surroundings.

The concept comprises two quantities: the rate of entropy generation inside the system (often denoted σ or S_dot_gen) and the rate of entropy flow across system boundaries (often denoted J_S or Φ_S). Together they describe the balance of entropy as systems evolve. In many formulations, the system’s entropy rate change dS/dt is related to σ and the net entropy flow across boundaries, emphasizing irreversibility and external exchanges.

Origin and usage of the term are most evident in specialized Swedish-language and European theoretical literature that seeks to unify internal irreversibility with external exchanges under a single descriptive pair. It is used to analyze energy systems, chemical reactors, and complex biological or information-processing networks where both internal generation of disorder and boundary exchanges are important.

Applications focus on understanding efficiency and control. Entropy generation arises from real-world irreversibilities such as friction, finite temperature differences, and chemical reactions, while entropy flow tracks heat and mass transfer to or from the environment. By examining the entropientropiflödespar, researchers aim to optimize performance and reduce wasted energy in practical systems.

See also: entropy, entropy production, non-equilibrium thermodynamics, open systems.