A closed system contains 0.5 kg of air. It expands from 2 bar, 60°C to 1 bar, 40°C. During expansion it receives 2 kJ of heat from a reservoir at 100°C. Assuming conditions to be atmospheric at 0.95 bar and 30°C, calculate (i) the maximum, work, (ii) work done on atmosphere, and (iii) change in availability.