$9\mathrm{.}44$ The cycle of Problem $9\mathrm{.}43$ is modified to include a regenerator with an effectiveness of $70\%.$ Determine

a$.$ the specific enthalpy, in $k\frac{J}{k}g,$ and the temperature, in K $,$ for each stream exiting the regenerator and sketch the $T-s$ diagram.

b$.$ the mass flow rate of air, in $k\frac{g}{s}.$

c$.$ the rate of heat transfer, in kW $,$ to the working fluid passing through the combustor.

d$.$ the thermal efficiency.