Electronic components are mounted on the inner surface of a horizontal cylindrical duct whose inner diameter is 0.2 m, as To prevent overheating of the electronics, the cylinder is cooled by a stream of air flowing through it and by air flowing over it outer surface. Air enters the duct at 25oC, 1 bar and a velocity of 0.3 m/s and exits with negligible changes in kinetic energy and pressure at a temperature that cannot exceed 40oC. At steady state the electronic components require 0.20 kW of electric power. Determine the minimum rate of heat transfer from the cylinder's outer surface, in kW, for which the limit on the temperature of the exiting air is met.