Carbon dioxide diffuses through a high-density polyethylene (hdpe) sheet 50 mm thick at a rate of 2.2 × 10–8 (cm3 stp)/cm2-s at 325 k. the pressures of carbon dioxide at the two faces are 4000 kpa and 2500 kpa, which are maintained constant. assuming conditions of steady state, what is the permeability coefficient at 325 k? express your answer in engineering notation to two significant figures.

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

Assuming compressible flow of air and that the measurements are done at flagstaff a pitot static tube that gives the difference of total and static pressure measures 0.35 m of mercury. what is the velocity of air? assume the temperature to be 300k. (submit your excel or matlab calculation sheet)

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.