A powerplant is emitting 80 g/s NO and has an effective stack height of 100 m. The windspeed is measured to be 4 m/s at a height of 10 m. It is a clear summer day and the sun is located directly overhead. Find: a. Ground-level NO concentration 2 km directly downwind of the powerplant. b. Maximum NO concentration at the ground-level. c. Ground-level NO concentration 2 km downwind and 0.1 km off the downwind axis.

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.