A piston cylinder device contains 0.25 kg of air initially at 1.8 MPa and 360 °C. The air is first expanded isothermally to 400 KPa, then compressed polytropically with a polytropic exponent of 1.2 to the initial pressure, and finally compressed at the constant pressure to the initial state. Determine the following: (a) The boundary work for the isothermal expansion process. (b) The boundary work for the polytropic compression process. (c) The boundary work for the constant pressure process. (d) The net work done during the cycle.