22. The function(s) of the draft tube in an airlift bioreactor is
A.to reduce bubble coalescence
B.to improve circulation
C.to even out shear conditions throughout the reactor
D.all of the above

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23. The Monod Model relates
A.substrate utilized with the biomass consumption
B.specific growth rate to the substrate availability
C.yield with the biomass utilization
D.the biomass concentration with specific growth rate

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24. The height to diameter ratio (H/D) for the column fermenters is
A.<3
B.>3
C.<1.5
D.>1.5

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25. The high oxygen transfer efficiencies of airlift bioreactors is due to
A.the large aspect ratio of the reactor, which leads to a high gas hold-up
B.the large aspect ratio of the reactor, which leads to a high oxygen solubility at the base of the reactor
C.the draft tube, which reduces bubble coalescence in the reactor
D.all of the above

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26. The maximum specific growth rate (μm) of an organism in batch culture is equal to slope of a plot of
A.In [biomass] against time for exponential phase data only
B.In [biomass] against time
C.biomass against time
D.biomass against time for stationary phase data only

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27. The region of an airlift bioreactor in which the liquid travels in a downward direction is called the
A.downcomer
B.disengagement zone
C.air riser
D.flotsam

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28. Population doubling time, td can be expressed as (where μ is the specific growth rate.)
A.log2/μ
B.ln2/μ
C.μ/ln2
D. μ/log2

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