A gas turbine operating on an ideal Brayton cycle has a pressure ratio of 7. The gas temperature is 570K at the compressor outlet and 640K at the turbine outlet. Determine the gas temperatures at the turbine and compressor inlets, the back work ratio, and the thermal efficiency. If a regenerator is then added to the system, which provides heat transfer from the turbine exhaust gas to the air before it enters the combustion chamber at a rate of 55.223 KJ/kg, determine the effectiveness of the regenerator and the new thermal efficiency.