Technician A says to grind less than 0.020" from the tip of a valve stem to avoid grinding through the hardened area. Technician B says that the tip should be ground approximately the same amount as the face and seat in order to minimize valve guide wear by centering the rocker arm on the stem tip when the valve is half open. Who is right? a. Technician A only
b. Technician B only
c. Both A and B
d. Neither A nor B

Give heat transfer applications for the following, (i) gas turbines (propulsion) ) gas turbines (power generation). (iii) steam turbines. (iv) combined heat and power (chp). (v) automotive engines

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?

How much power could a wind turbine produce if it had the following specifications? cp = 0.45 -d=1.2kg/m3 d=50m v 5m/s