Two parallel planes 1.2x1.2 are splited by a distance of 1.2 m. the emissivity's of the planes are 0.4 and 0.6, and the temperature are 760 and 300 oC, correspondingly. A 1.2x1.2 radiation shield having an emissivity of 0.05 on both side situated equidistance among the two planes. The combined arrangement is placed in a large room which is maintained at 40 oC. (a) Determine heat transfer rate from each of the two planes if the shield were not present. (b) Determine heat transfer rate from each of the two planes if the shield were present. (c) Temperature of the shield.