Consider a simple Brayton Cycle using air as the working fluid; has a pressure ratio of 12; has a maximum cycle temp of 600 Celsius; and operates the compressor inlet at 90 kPa and 15 Celsius. Which will have the greatest impact on the back work ratio; a compressor isentropic efficiency of 90 percent or a turbine isentropic efficiency of 90 percent? Use a constant specific heats at room temperature.