questions

A. square root of the impeller diameter
B. impeller diameter
C. cube of the impeller diameter
D. square of the impeller diameter
A. bubbles tend to break down too rapidly under high shear conditions
B. bubbles tend to coalesce under the impeller
C. the cells clog up the surface of the bubble
D. bubbles tend to move too quickly through the bulk liquid
A. concentration is greater than the critical concentration
B. concentration is less than the critical concentration
C. levels are equal to saturation oxygen level
D. levels are greater than the saturation concentration of oxygen
A. 20,000 l
B. 10,000 l
C. 40,000 l
D. 30,000 l
A. axial flow impeller
B. radial flow impeller
C. Rushton turbine
D. intermig impeller
A. causes bubbles to expand
B. enhances bubble coalescence
C. increases the surface tension of the liquid
D. discourages bubble coalescence
A. 0.207atml/mmol
B. 0.793atml/mmol
C. 8.74 atml/mmol
D. 1.26 atml/mmol
A. accumulate at the gas liquid interface
B. decrease the surface tension of the liquid
C. all of the above
D. decrease the rate of bubble coalescence
A. Microbial growth is not oxygen limited since the oxygen concentration is lesser than the saturation concentration
B. Microbial growth is oxygen limited since the oxygen concentration is lesser than the saturation concentration
C. No conclusion can be drawn
D. Experimental error leads to the reduction
A. The fermenter medium spills out the reactor due to foaming
B. The air escapes without being distributed by the agitator
C. None of the above
D. The volume of foam is more than the volume of broth
A. Reynolds number is less than 300
B. baffled systems are used
C. none of these
D. both (and(
A. power consumption
B. superficial gas velocity
C. gas concentration
D. Both ( and (
A. the oxygen transfer rate and the bubble size
B. the partial pressure of oxygen and the saturation concentration of oxygen in the liquid
C. the oxygen transfer rate to the partial pressure of oxygen in the liquid
D. the oxygen transfer rate and the temperature
A. lowering KLa but increasing C*o
B. increasing KLa but lowering C*o
C. lowering KLa and lowering Co
D. increasing KLa and increasing Co
A. using diffusion ring with turbines
B. using baffles
C. none of these
D. both ( and (
A. flooded impeller
B. coalesced impeller
C. dry impeller
D. river impeller
A. tend to accumulate in the gas liquid interface
B. increase the tendency of bubbles to coalesce .
C. All of the above answers
D. reduce the surface tension of the liquid