Clausius theorem

Developed by German physicist and mathematician Rudolf Clausius.

the Clausius theorem

1. A theorem stating that, for a thermodynamic system exchanging heat with external reservoirs and undergoing a thermodynamic cycle, ${\displaystyle \oint {\frac {\delta Q}{T_{\text{surr}}}}\leq 0,}$, where ${\displaystyle \delta Q}$ is the infinitesimal amount of heat absorbed by the system from the reservoir, and ${\displaystyle T_{\text{surr}}}$ is the temperature of the external reservoir (surroundings) at a particular instant in time.