Consider a 300 mm + 300 mm window in an aircraft. For a temperature difference of 80-C from the inner to the outer surface of the window, calculate the heat loss through L % 10-mm-thick polycarbonate, soda lime glass, and aerogel windows, respectively. The thermal conductivities of the aerogel and polycarbonate are kag % 0.014 W/m!K and kpc % 0.21 W/m!K, respectively. Evaluate the thermal conductivity of the soda lime glass at 300 K. If the aircraft has 130 windows and the cost to heat the cabin air is $1/kW! h, compare the costs associ- ated with the heat loss through the windows for an 8-hour intercontinental flight.