Two different bacterial species with doubling times of 2h and 4h are growing in a batch nutrient-rich medium with their maximum growth rate. the initial concentrations are the same.

a. What would be the ratio of X1/X2 after 10h of batch growth?
b. How long should the batch growth of the mixed cultures last in order to obtain X1/X2 = 10? Assume exponential growth

What is creep? what is stress relaxation?

To save energy, the air supply to a 2000 ft office has been shut off overnight and the room temperature has dropped to 40°f. in the morning, the thermostat is reset to 70°f and warm air at 120 f begins to flov in at 200ft'/min. the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct. the air pressure is nearly 1 atm everywhere. ignoring heat transfer with the surroundings and kinetic and potential energy effects, estimate how long it takes for the room temperature to reach 70°f. plot the room temperature as a function of time.

The quality is zero at a)-the saturated vapour state b)-the saturated liquid state c)-the saturated liquid-vapour mixture state d)-none of the states in the other answers