Aww plant has ww with 450 mg/l bod (the soluble bod is 250 mg/l) and 280 mg/l ss. the biological tower treatment process consists of high-density, cross-flow packing media with dimensions of 480 sq ft by 20 ft high. the packing has a specific area of 42 sq ft/cubic ft, n = 0.5 and k20 =0.0035 (gpm/sq ft)0.5. the primary clarifier effluent is 0.8 mgd at 18oc. the recirculation ration is 1.0. calculate the effluent soluble bod at 20oc, then correct the calculation for actual temperature. calculate the soluble and total effluent bod assuming that the effluent has 0.54 soluble bod/total bod.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.