It is proposed to deposit a 5 μm thick nickel coating uniformly on all surfaces of a ceramic strip measuring 15 cm x 5 cm x 2 cm by employing a vapor-phase deposition (evaporation-condensation) technique. The vapor pressure-temperature relationship for liquid Ni is of the following form: ln p (atm) = -(51,590/T) – 2.01 ln T + 32.40. The normal melting point and boiling point of nickel are 1453 C and 2730 C, respectively, and the density and atomic weights of Ni are 8.91 g. cm-3 and 58.71 atomic mass units respectively. Calculate the energy in joules needed to evaporate the required quantity of nickel.

Heat is added to a piston-cylinder device filled with 2 kg of air to raise its temperature 400 c from an initial temperature of t1 27 cand pressure of pi 1 mpa. the process is isobaric process. find a)-the final pressure p2 b)-the heat transfer to the air.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa. s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)