A sewage lagoon that has a surface area of 50,000m2 and a depth of 2m is receiving 8500m3d-1 of sewage containing 150mg/L of biodegradable contaminants. At steady state, the effluent from the lagoon must not exceed 20mg/L of biodegradable contaminant. Assuming the lagoon is well mixed and that there are no losses or gains of water in the lagoon other than the sewage input. What is the biodegradation reaction rate (d-1) for a first order reaction

1in2 processor chip can be modelled as an isothermal plane wall of silicon, isothermal on both sides. the power input to the bottom of the plane wall, or the processing power of the chip, often called the thermal design power (tdp), is 100w. assume the periphery is adiabatic. the silicon is 400 microns thick. the temperature at the junction, or in this case on the bottom of the isothermal plane wall, is 85°c. what is the top surface temperature, assuming that the only mode of heat transfer is conduction