A wastewater plant discharges 3 MGD of effluent with a dissolved oxygen concentration of 0.5 mg/L into a chloride-free river flowing at 50 cfs. Upstream of the wastewater treatment plant outfall, the river is saturated with oxygen an at a temperature of 46.4 Fahrenheit degrees (8 Celsius degrees). What is most nearly the dissolved oxygen deficit (in mg/L) in the river just downstream of the outfall caused by the wastewater treatment plant discharge?

10 kg of co2 is initially contained at 400 kpa and 300 k. the gas constant for carbon dioxide is 189 j/lkg k) and has a specific heat ratio, k, of 1.289. isentropic expansion then occurs until the pressure is 200 kpa. a) determine the initial volume of co2 in m. b) determine the final temperature in k. c) determine the work done by the system during the expansion kl.

Afoot bridge is made as a simple deck, 4 m long, with a cross section 2 m (wide) and 20 cm thick, and made of wood. the deck is supported at the two ends. the maximum load allowable on the bridge is 10 tons, provided it is uniformly distributed on the deck. to sense this load, a strain gauge is placed at the center of the bridge and its resistance is monitored. if the sensor has a nominal resistance of 350 s2 and a gauge factor of 3.6, what is the reading of the strain gauge at maximum load? the modulus of elasticity for the wood used in the construction is 10 gpa.

Heat transfer by is the fastest mode of heat transfer that requires no intervening medium. a)-conduction b)-convection c)-radiation d)-conduction and convection