Translations:Thermodynamic and Mechanical Study/558/en

${\dot{H}}_{ab}=\{\begin{array}{cc}{\dot{m}}_{ab}{C}_p{T}_a,& {\dot{m}}_{ab}\ge 0,\\ {\dot{m}}_{ab}{C}_p{T}_b,& {\dot{m}}_{ab}<0.\end{array}$