5.16. Imagine that a stream of fluid in steady-state flow serves as a heat source for an infinite set of Carnot engines, each of which absorbs a differential amount of heat from the fluid, causing its temperature to decrease by a differential amount, and each of which rejects a differential amount of heat to a heat reservoir at temperature T. As a result of the operation of the Carnot engines, the temperature of the fluid decreases from T1 to T2. Equation (5.8) applies here in differential form, wherein is defined as: dW/d