Permeability centrifugal filtration

For cakes of high permeability, the capillary drain height may be an insignificant fraction of cake thickness, and film drainage becomes the controlling factor in a centrifugal field (7). Under unsteady-state conditions, equation 18 represents the drainable liquid left in the cake as a function of the centrifugal filtration parameters ... 

Although there is much evidence to suggest that the envelopes of photosyntheti-cally competent plastids are relatively impermeable to MVA, the origin of the MVA required for chloroplastidic terpenoid biosynthesis in plastids that are not able to fix CO2 is not yet certain. Studies using silicone-oil centrifugal filtration have shown that etioplasts and 1—2 h etiochloroplasts have envelopes that are permeable to acetate and MVA, but plastids from etiolated tissues that have been illuminated for periods of 4 h or longer show progressive impermeability to these precursors. 

It is inportant to measure a parameter that is relevant to tire process because ahhoir other measurements of behaviour will be rdat they may not have a close or linear relationship. Thus for a gravity sedimentation ipphcatitni it is obviously senile to measure settling rate and for filtration it would be appropriate to examine permeability or specific cake redstance. hr some processes such as sedimenting centrifugation and... 

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