Exposure to high concentration of gaseous ammonia can cause lung damage. To prevent gaseous ammonia from leaking out, ammonia is transported in its liquid state through a pipe (k 5 25 W/m?K, Di, pipe 5 2.5 cm, Do, pipe 5 4 cm, and L 5 10 m). Since liquid ammonia has a normal boiling point of 233.38C, the pipe needs to be properly insulated to prevent the surrounding heat from causing the ammonia to boil. The pipe is situated in a laboratory, where air at 208C is blowing across it with a velocity of 7 m/s. The convection heat transfer coefficient of the liquid ammonia is 100 W/m2?K. Calculate the minimum insulation thickness for the pipe using a material with k 5 0.75 W/m?K to keep the liquid ammonia flowing at an average temperature of 2358C, while maintaining the insulated pipe outer surface temperature at 108C