Which of the following statements is false regarding the Headworks design? O Low approach velocity increases solids deposition is the channel High velocity through the bar screen decreases headloss through screens High velocity through the bar screen increases the pass-through of debris The buildup of the headloss increase the water level before the screen

A settling chamber is to be used to collect particles of 50 micrometers diameter and 1400 kg/m3 density from a stream of air 1 atm and 300 degree kelvin with a volume flow rate of 2.5 m3/s. The overall chamber is 2m high, 4m wide and will have 25 trays including the bottom surface. Assuming laminar flow  (a) How long is the chamber for 100 percent removal efficiency  (b) What is the collection efficiency for particle sizes of 40, 30, 20 and 10 micrometers using the length found in part a

1. (e) One of the limitations of extending axis translation technique for measuring negative pore water pressure using null type pressure plate is: (i)Air diffusion occurs through the ceramic disk when the axis translation test is performed for a long time period. (ii) Water losses from specimen when the test is performed for a long time period. (iii) Secondary consolidation arises when test is performed for a long period of time (iv) All the above (a, b and c) (v) None of the above The ceramic disk used in the null pressure plate apparatus does not allow the air to flow; however, free flow water is possible. Explain the mechanism associated with this behavior. If the purpose of ceramic disk is not to allow the air out from it; how can the air come out from the specimen? What will be the impact of such a phenomenon?

A long, straight, horizontal 1000 ft length of 2 ft diameter pipe carries a 60°F water flow of 30 cfs. At this temperature, the water density is 1.94 slug/ft³, and the viscosity is 2.35x105 slug/ft-s. The equivalent sand grain roughness of the pipe is 0.0033 ft. What is the pressure drop over this length of pipe?