16 the oxygen sag caused by a cannery reaches a minimum do equal to 3.0 mg/l. upstream from the cannery, the river do is saturated at 10.0 mg/l, and it has no bod of its own. just downstream from the discharge point, the do is still essentially saturated (i. e., consider the initial oxygen deficit to be zero so the downstream deficit is propositional to the initial bod). by what percentage should the bod of the cannery waste be reduced to assume a healthy stream with at least 5.0 mg/l do everywhere?

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.