Helmholtz free energy

Etymology
For, German physicist.

Noun

 * 1)  A measure of the useful work obtainable from a constant temperature, constant volume thermodynamic system; more precisely, the difference between internal energy (of a system) and the product of its absolute temperature and entropy.
 * $$ A = U - T S $$ where A is Helmholtz free energy, U is internal energy, T is temperature, and S is entropy.

Translations

 * Chinese:
 * Mandarin: 亥姆霍茲自由能
 * Finnish: Helmholtzin vapaa energia
 * Russian: свобо́дная эне́ргия Гельмго́льца