Air enters the compressor of an ideal Brayton refrigeration cycle at 120 kPa and 275 K. The compressor pressure ratio is 3, and the temperature at the turbine inlet is 325 K. Treating air as a perfect gas, consider that the compressor and turbine have isentropic efficiencies of 80% and 90%, respectively. Determine for the modified cycle, (a) the coefficient of performance and (b) the irreversibility rates, per unit mass of air flow, in the compressor and turbine, each in kJ/kg, for T0 = 300 K.