A cylindrical storage tank, 1 m diameter by 1.2 m long has an outside surface temperature of 60 0C, and emissivity of 0.9. Calculate the rate of heat loss by radiation when the tank is in a large room, the walls of which are at 15 0C. Calculate also the reduction in the rate of heat loss by radiation if the tank is painted with aluminum paint of emissivity 0.4. Assume that the tank is a grey body.