Aheat pump with refrigerant-134a as the working fluid is used to keep aspace at 25°c by absorbing heat from geothermal water that enters the evaporator at 60°c at a rate of 0.065 kg/s and leaves at 40°c. refrigerant enters the evaporator at 12°c with a quality of 15 percent and leaves at the same pressure as saturated vapor. if the compressor consumes 1.6 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the rate of heat supply, (c) the cop.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?

What is the major difference between thermoplastics and thermosetting plastics from the polymerization structure point of view?