logo

CuriousTab

CuriousTab

Discussion


Home Biochemical Engineering Agitation and Aeration Comments

  • Question
  • Froude number is avoided in calculation of power requirements for low viscosity liquid mixing systems when


  • Options
  • A. baffled systems are used
  • B. Reynolds number is less than 300
  • C. both (a)and(b)
  • D. none of these

  • Correct Answer
  • both (a)and(b) 


  • Agitation and Aeration problems


    Search Results


    • 1. Monoclonal antibodies are typically produced in fed batch reactors because

    • Options
    • A. hybridoma cells ferment at high maltose concentrations
    • B. hybridoma cells yield higher lactate at high glucose concentrations
    • C. hybridoma cells respire at high glucose concentrations
    • D. none of the above
    • Discuss
    • 2. Yeast is typically produced in fed batch reactors because

    • Options
    • A. yeast cells produce ethanol at low glucose concentrations
    • B. yeast cells ferment at low glucose concentrations
    • C. yeast cells respire at low glucose concentrations
    • D. all of the above
    • Discuss
    • 3. Continuous culture has an advantage over to a batch cultures as

    • Options
    • A. continuous reactors do not need to be shut down and cleaned as regularly as a batch reactor
    • B. most downstream and upstream processes are continuous in nature and thus the operation of continuous bioreactor can be better integrated into the overall manufacturing process
    • C. cells can be maintained at a constant physiological state simply by setting the dilution rate
    • D. all of the above
    • Discuss
    • 4. In an activated sludge process, the biomass is recycled to

    • Options
    • A. increase the efficiency of the process
    • B. reduce sludge volumes
    • C. increase the concentration of cells
    • D. all of the above
    • Discuss
    • 5. Production of organic acids in batch culture is generally growth associated phase followed by non-growth associated production. The probable reason for this is that

    • Options
    • A. organic acids uncouple catabolism from anabolism
    • B. biomass yields increase as the fermentation proceeds
    • C. organic acids are secondary metabolites
    • D. high concentrations of organic acid promote the growth of the microbial population
    • Discuss
    • 6. Larger propellers turn at the speed of

    • Options
    • A. 20 to 150 rpm
    • B. 150 to 300 rpm
    • C. 400 to 800 rpm
    • D. 1150 rpm
    • Discuss
    • 7. What is/are the major difference(s) between disc and turbine type stirrer?

    • Options
    • A. Blades in disc type are projected out beyond the edge of disc while blades are curved one in turbine type
    • B. Turbine type requires 50 % less air than disc type for the same yield and energy consumption
    • C. Both (a) and (b)
    • D. Number of blades in the stirrer
    • Discuss
    • 8. In the bubble boundary layer, oxygen concentration can be determined by measuring

    • Options
    • A. the steady state oxygen concentration in a mixed aerated reactor before inoculation
    • B. the steady state oxygen concentration in a mixed aerated reactor after inoculation
    • C. the steady state oxygen concentration in the boundary layer using a micro-probe
    • D. volume of oxygen supplied
    • Discuss
    • 9. The addition of antifoams to an aerated bioreactor will decrease oxygen transfer rates because antifoams

    • Options
    • A. increase the tendency of bubbles to coalesce
    • B. tend to accumulate in the gas liquid interface
    • C. reduce the surface tension of the liquid
    • D. All of the above answers
    • Discuss
    • 10. The dynamic technique is based on the

    • Options
    • A. oxygen material balance in an aerated batch fermenter during the growth of microorganisms
    • B. change of the oxygen concentration
    • C. oxidation of the sodium sulfite to sodium sulfate
    • D. oxygen material balance in a fermenter
    • Discuss


    Comments

    There are no comments.

Enter a new Comment