Consider a regenerative Brayton cycle operating with a pressure ratio of $8,$ where the air enters the compressor at $300$ K and $100$ kPa, while it enters the turbine at $1060$ K$.$ Assume that both the compressor and turbine are isentropic$,$ that speci$$c heats vary with temperature, and that the regenerator has an effectiveness of $74\%.$ Round all intermediate calculations to three decimal places.

What is the enthalpy at the entrance to the heat exchanger that rejects heat to the surrounding in kJ$/$kg$?$ Round your answer to two decimal places.

How much heat is rejected to the surroundings in kJ$/$kg$?$ Round your answer to two decimal places.

How much net work is produced in kJ$/$kg$?$ Round your answer to two decimal places.

What is the thermal efficiency as a percentage $(0\%-100\%)?$ Round your answer to one decimal place.

What is the thermal efficiency as a percentage $(0\%-100\%)$ if there was no regenerator? Round your answer to one decimal place.