Consider a 320 mm × 320 mm window in an aircraft. for a temperature difference of 80°c from the inner to the outer surface of the window, calculate the heat loss through l= 10-mm-thick polycarbonate, soda lime glass, and aerogel windows, respectively. the thermal conductivities of the aerogel and polycarbonate are ka⁢g= 0.014 w/m·k and kp⁢c= 0.21 w/m·k, respectively. evaluate the thermal conductivity of the soda lime glass at 300 k. if the aircraft has 110 windows and the cost to heat the cabin air is $1/kw·h, compare the costs associated with the heat loss through the windows for an 8-hour intercontinental flight.

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?

Burgers vector is generally parallel to the dislocation line. a)-true b)-false

For each of the following process: a) sketch the p-v diagram, b)sketch t-s diagram, c) sketch t-v diagram, d) sketch the boundary work on one of the diagrams (a, b or c) and e) sketch the reversible heat transfer on one of the diagrams (a, b or c): 1- isobaric process from compressed liquid to superheated vapor 2- isothermal process from compressed liquid to superheated vapor 3- isentropic process from compressed liquid to superheated vapor