Biochem - Fluid Flow Flashcards
(47 cards)
1
Q
- The viscosity of liquid was classified as both dilatant and rheopectic, which means that the viscosity
A
- Increased with stirring speed and increased with mixing time
2
Q
- Which of the following describes the detrimental effect of bubbles on animal cells?
A
- Both (a) and (b)
3
Q
- A fluid in which the viscosity decreases with increasing stirrer speed and mixing time, can be represented as
A
- Pseudoplastic, thixotropic fluid
4
Q
- Filamentous fungal cells are more shear sensitive than bacterial cells because of
A
- All of the above
5
Q
- The viscosity of water at STP is approximately
A
- 0.001 kg.m-1.s-1
6
Q
- Bubble free aeration systems requires
A
- Silicone tubing or gas permeable membranes to facilitate gas transfer
7
Q
- Non-linear relationship between shear stress and shear rate exists in
A
- Non-Newtonian fluids
8
Q
- If the viscosity of a fluid decreases with increasing stirrer speed, then the nature of the fluid is
A
- Pseudoplastic
9
Q
- A pseudoplastic fluid is one in which the viscosity
A
- Decreases with increasing stirrer speed
10
Q
- A viscoelastic fluid is one in which the viscosity
A
- Changes during mixing but returns to its original state after mixing
11
Q
- Mixing in stirred tank reactors can
A
- All of the above
12
Q
- In animal cell bioreactor, bubble damage can be minimized by
A
- All of the above
13
Q
- The viscosity of a fluid changes with either stirrer speed or mixing time. But when mixing ceases, the viscosity returns to its original state. This fluid is best described as
A
- Thixotropic
14
Q
- In sparged mammalian cell bioreactors, the cell damage is caused because of
A
- All of the above
15
Q
- The SI unit for viscosity is
A
- kg.m-1.s-1
16
Q
- The viscous nature of a non-Newtonian fluid
A
- Changes with the level of power input and/or the length of time during which the fluid is mixed
17
Q
- Which of the following compound, if added to a solution will lead to the greatest increase in viscosity?
A
- A long chain protein such as albumin
18
Q
- A Brookfield viscometer measures viscosity by determining
A
- The torque required to move an impeller at a set speed
19
Q
- Which of the following factors will affect the sensitivity of animal cells to shear conditions?
A
- All of the above
20
Q
- The best described action of Pluronic F68 (non-ionic detergent) in a cell culture medium is that, it
A
- Acts on the surface properties of the cells and the culture medium
21
Q
- Water is a
A
- Newtonian fluid
22
Q
- Which of the following affect the Kolmogorov eddy size?
A
- All of these
23
Q
- A liquid is flowing at 11,400 l.h-1 along a pipeline having a diameter of 4 cm. If the liquid has a density of 1 g.ml-1 and viscosity of 0.001kg.m-1.s-1, then the liquid would be in the
A
- Turbulent phase
24
Q
- The viscosity of a fluid increases with the length of time that it is being mixed. This fluid would be best described as being
A
- Rheopectic
25
25. Which of the following can act as a shear protectorant?
25. Serum
26
26. The viscosity of a fluid increases with increasing stirrer speed. This fluid would be best described as being
26. Dilatant
27
27. A dilatant fluid is one in which the viscosity
27. Increases with increasing stirrer speed
28
28. A rheopectic fluid is one in which the viscosity
28. Increases with mixing time
29
29. A fluid in which the viscosity increases with increasing stirrer speed and mixing time can be called as
29. Dilatant, rheopectic fluid
30
30. The medium will have the highest viscosity (considering that the cells do not secrete gums) with the presence of
30. Filamentous fungi that grow as long poorly branched chains
31
31. A Newtonian fluid is one in which the viscosity
31. Is constant regardless of the stirrer speed or mixing time
32
32. Which pattern of mixing is preferred in stirred tank reactors during the culture of aerobic microorganisms?
32. Turbulent flow
33
33. Animal cell cultures do not have much effect on shear forces because
33. The cell size is generally smaller than the critical eddy size at which shear will have an effect
34
34. The viscosity of the culture fluid is classified as both pseudoplastic and thixotropic which indicates that the viscosity
34. Decreases with stirring speed and decreases with mixing time
35
35. Pluronic F68 is added to cell culture media as
35. A shear protectorant
36
36. A stirred tank reactor containing a fluid with a density of 2.5 g.ml-1 and viscosity of 0.002 kg m-1s-1 is mixed at 120 rpm. If the fluid is mixed with an impeller having diameter 50 cm, then the Reynolds number of the liquid in the reactor is
36. 12,50,000
37
37. If the viscosity of a fluid decreases with the length of time that it is being mixed, then this fluid is
37. Thixotropic
38
38. Which of the following describes the importance of the Kolmogorov eddy size in the biotechnology?
38. All of the above
39
39. A thixotropic fluid is one in which the viscosity
39. Decreases with mixing time
40
40. Newtonian fluid is one in which the viscosity
40. Remains constant with time and power input
41
41. Reynolds number for laminar flow over a plate should be less than
41. 5×1055×105
42
42. The approach which is commonly used to determine the level of damage to animal cells in a culture medium is to monitor
42. The level of lactate dehydrogenase activity
43
43. A Brookfield viscometer cannot determine the shear stress because
43. The impeller type is given only by numbers
44
44. Which of the following is correct?
44. The viscosity of gases decreases with increasing temperature, but decreases in liquids
45
45. The Komologorov eddy size
45. Decreases with stirrer speed
46
46. Pluronic F68 protects mammalian cells from damage stems as it is a/an
46. Surface active agent which stabilizes foams
47
47. Reynolds number for turbulent flow over a plate should be more than
47. 5×1055×105
