One kg of R-134a contained within a piston-cylinder assembly undergoes a process from a state where the temperature is T1 = 20◦C and the refrigerant is a saturated liquid to a state where the pressure is p2 = 10 bar and the quality is x2 = 50%. Determine the change in specific entropy of the refrigerant, in kJ/kg·K. Can this process be accomplished adiabatically?

Atank with constant volume contains 2.27 kg of a mixture of water phases (liquid-vapor). in the initial state the temperature and the quality are 127 °c and 0.6, respectively. the mixture is heated until the temperature of 160 oc is reached. illustrate the process in a t-v diagram. then, determine (1) the mass of the vapor in kg at the initial state, (2) the final pressure in kpa.

Air inially occupying a volume of 1 m2 at 100 kpa, 27 c undergoes three internally reversible processes in series. process 1-2 compression to 500 kpa during which pv constant process 2-3 adiabatic expanslon to 100 kpa process 3-1: constant-pressure expansion to 100 kpa (a) calculate the change of entropy for each of the three processes. (b) calculate the heat and work involved in each process. (c) is this cycle a power cycle or refrigeration cycle?

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