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