<Dl> <Dd> f (T 1, T 3) = g (T 3) g (T 1) = q 3 q 1 . (\ displaystyle f (T_ (1), T_ (3)) = (\ frac (g (T_ (3))) (g (T_ (1)))) = (\ frac (q_ (3)) (q_ (1))).) </Dd> </Dl> <Dd> f (T 1, T 3) = g (T 3) g (T 1) = q 3 q 1 . (\ displaystyle f (T_ (1), T_ (3)) = (\ frac (g (T_ (3))) (g (T_ (1)))) = (\ frac (q_ (3)) (q_ (1))).) </Dd> <P> i.e. The ratio of heat exchanged is a function of the respective temperatures at which they occur . We can choose any monotonic function for our g (T) (\ displaystyle g (T)); it is a matter of convenience and convention that we choose g (T) = T (\ displaystyle g (T) = T). Choosing then one fixed reference temperature (i.e. triple point of water), we establish the thermodynamic temperature scale . </P> <P> It is to be noted that such a definition coincides with that of the ideal gas derivation; also it is this definition of the thermodynamic temperature that enables us to represent the Carnot efficiency in terms of T and T, and hence derive that the (complete) Carnot cycle is isentropic: </P>

Kinetic energy and total energy at triple point