Aflat tissue engineered skin (thickness 2.3 mm) is attached to the bottom of a dish and cultured with cell media atop it (which has an oxygen concentration of 0.15 mol/m3). the diffusivity of oxygen in the skin is 3.4 e-9 m2/s, and according to experiments that you’ve performed, you want to make sure that the concentration of oxygen in the device doesn’t fall below 0.060 mol/m3. (below that concentration harms the cells.)

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?

What is the direction and how to operate the lathe?

List three applications of coordinate measuring machine (cmm)