Design a journal bearing, required to resist a radial load of 8 kN. The oil used has a viscosity of 0.0087 kg/m-s at the operating temperature of 80C. Shaft speed is 720 rpm. Bearing diametral clearance may be assumed as 0.00025 mm per mm diameter and ambient temperature is 30C. If the heat radiating capacity of the bearing is 150 N-m per second per square meter of projected area of bearing per C, determine whether artificial cooling is necessary.