Studies on transfer processes in mixing vessels: effect of particles on gas-liquid hydrodynamics using modified Rushton turbine agitators

1997 ◽  
Vol 16 (3) ◽  
pp. 135 ◽  
Author(s):  
R. V. Roman ◽  
R. Z. Tudose
Keyword(s):  
Rushton Turbine ◽  
Transfer Processes ◽  
Mixing Vessels

scholarly journals Periodic Behaviour of Mean Velocity Fields in Rushton Turbine (RT) Driven Stirred Tank

2019 ◽  
Vol 4 (6) ◽  
pp. 1341-1351
Author(s):  
Devarajan Krishna Iyer ◽  
Ajey Kumar Patel
Keyword(s):  
Axial Direction ◽  
Velocity Fields ◽  
Stirred Tank ◽  
Cfd Model ◽  
Mean Velocity ◽  
Rushton Turbine ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Periodic Behaviour ◽  
Cylindrical Region

The present study predicts the periodic behavior of mean velocity fields from the properly verified and validated CFD model to determine the extent of vortex and turbulent activity in a baffled tank stirred by standard six bladed Rushton Turbine. This region includes most of the vortex and turbulent action that controls the mixing and mass transfer processes in the stirred tank. The complexity of periodicity of mean radial and tangential velocities in the radial direction and mean axial velocity in the axial direction is used to fix the proper radial as well as axial extents of the vortex generated by RT. The extent of flow periodicity in the present stirred tank configuration is confined within a cylindrical region around the impeller of radius 0.753 times the impeller diameter and a height of 0.323 times the impeller diameter above and below the impeller center plane.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

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