Determine the carburizing time necessary to achieve a carbon concentration of 0.45 wt% at a position 2mm into the iron-carbon alloy that initially contains 0.2wt.% C. The surface concentration is to be maintained at 1.3wt.% C, and the treatment is to be conducted at 1000oC. (D = 1.93 x 10-11 m2/s). Assume non-steady state diffusion

An air conditioning system consist of a 5 cm diameter pipe, operating at a pressure of 200 kpa. the air initially enters the pipe at 15°c with a velocity of 20 m/s and relative humidity of 80%. if the heat supply throughout the process is 960 w, determine the relative humidity and the temperature at the outlet

Which from the following instrument is commonly used to detect the high pitch butzing sound in bearings? [clo4] a)-digital ultrasonic meter b)-infrared camera c)-spectroscopic d)-vibrometer

Air (c-1.006 kj/kg. k, r-0.287 kj/kg. k) enters a nozzle steadily at 280 kpa and 77°c with a velocity of 50 m/s and exits at 85 kpa and 320 m/s. the heat losses from the nozzle to the surrounding medium at 20°c are estimated to be 3.2 kj/kg. determine (a) the exit temperature and (b) the total entropy change for this process. solve this problem using constant specific heats.