DOUBLE DIFFUSION EFFECTS IN A CYLINDRICAL POROUS BED, FILLED WITH SALT WATER

1986 ◽  
Author(s):  
H. Sandner
Keyword(s):  
Salt Water ◽  
Double Diffusion ◽  
Porous Bed ◽  
Diffusion Effects

The evolution of under-ice melt ponds, or double diffusion at the freezing point

1974 ◽  
Vol 64 (3) ◽  
pp. 507-528 ◽  
Author(s):  
Seelye Martin ◽  
Peter Kauffman
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Freezing Point ◽  
Salt Water ◽  
Ice Sheet ◽  
Water Layer ◽  
Double Diffusion ◽  
Theoretical Models ◽  
Interfacial Region ◽  
Ice Melt

In an experimental and theoretical study, we model a phenomenon observed in the summer Arctic, where a fresh-water layer at a temperature of 0°C floats both over a sea-water layer at its freezing point and under an ice layer. Our results show that the ice growth in this system takes place in three phases. First, because the fresh-water density decreases upon supercooling, the rapid diffusion of heat relative to salt from the fresh to the salt water causes a density inversion and thereby generates a high Rayleigh number convection in the fresh water. In this convection, supercooled water rises to the ice layer, where it nucleates into thin vertical interlocking ice crystals. When these sheets grow down to the interface, supercooling ceases. Second, the presence of the vertical ice sheets both constrains the temperatureTand salinitysto lie on the freezing curve and allows them to diffuse in the vertical. In the interfacial region, the combination of these processes generates a lateral crystal growth, which continues until a horizontal ice sheet forms. Third, because of theTandsgradients in the sea water below this ice sheet, the horizontal sheet both migrates upwards and increases in thickness. From one-dimensional theoretical models of the first two phases, we find that the heat-transfer rates are 5–10 times those calculated for classic thermal diffusion.

Mixed convection flow of couple stress fluid between rotating discs with chemical reaction and double diffusion effects

2016 ◽  
Vol 5 (4) ◽  
Author(s):  
K. Kaladhar ◽  
D. Srinivasacharya
Keyword(s):  
Chemical Reaction ◽  
Couple Stress ◽  
Double Diffusion ◽  
Couple Stress Fluid ◽  
Convection Flow ◽  
Rotating Disks ◽  
Soret And Dufour Effects ◽  
Rotating Discs ◽  
Diffusion Effects ◽  
Lower Disc

AbstractThe chemical reaction, Soret and Dufour effects on steady flow of a couple stress fluid between two rotating disks are studied. The lower disc is rotating with angular velocity

MHD and Double Diffusion Effects on Heat and Mass Transfer in Non-Darcy Fluid Flows Over a Vertical Plate

2012 ◽  
Author(s):  
A. S. N. Murti ◽  
P. K. Kameswaran ◽  
T. Poorna Kantha ◽  
A. A. V. L. A. S. Acharyulu
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Vertical Plate ◽  
Fluid Flows ◽  
Double Diffusion ◽  
Integration Scheme ◽  
Physical Parameters ◽  
Transfer Rates ◽  
Linear Partial Differential Equations ◽  
Diffusion Effects

In the present paper we investigate double diffusion effects on mixed convective heat and mass transfer over a Newtonian vertical plate. Diffusion and chemical reaction terms are considered in the energy and concentration equations. A similarity transformation was used to convert governing non linear partial differential equations into ordinary. The dimensionless governing equations are solved numerically by using fourth-order Runge–Kutta integration scheme along with shooting technique. Detailed results for various physical parameters like velocity, temperature and concentration fields as well as the heat and mass transfer rates have been presented. In the absence of Magnetic and double diffusion effects our results are good in agreement with the results in the literature.

Theoretical Study of a Laminar Jet in a Double-Diffusion Environment

1995 ◽  
Vol 117 (3) ◽  
pp. 341-346 ◽  
Author(s):  
M. Priven ◽  
J. F. Atkinson ◽  
G. A. Bemporad ◽  
H. Rubin
Keyword(s):  
Theoretical Study ◽  
Double Diffusion ◽  
Two Dimensional ◽  
Local Reference Frame ◽  
Field Development ◽  
Laminar Jet ◽  
Fluid Layers ◽  
Diffusion Effects ◽  
Local Reference ◽  
Layer Development

The flow field development associated with the injection of negatively, neutrally, and positively buoyant fluid layers into a stratified environment was analyzed in this study. The analysis considered two-dimensional (horizontal slot) fluid injection under laminar conditions in either temperature-stratified, salinity-stratified or double-diffusive stratified environments. The major features characterizing the buoyant layer development were identified. A numerical model, which integrates in a local reference frame the equations governing mass, momentum, heat and salinity fluxes, was developed. The model was used to examine the characteristic flow patterns for the two-dimensional buoyant discharges of interest in this study. It was also possible to show that double-diffusion effects may significantly influence the development of initially neutral fluid layers and cause a certain vertical deviation.

Immunological Evidence for Prothrombin in Human Platelets

1986 ◽  
Vol 55 (02) ◽  
pp. 268-270
Author(s):  
R J Alexander
Keyword(s):  
Electrophoretic Mobility ◽  
Platelet Activation ◽  
Double Diffusion ◽  
Human Platelets ◽  
Secreted Proteins ◽  
Platelet Surface ◽  
Activated Platelets ◽  
Similar Protein ◽  
Diffusion Assay ◽  
Supernatant Solution

SummaryAn attempt was made to isolate from plasma the platelet surface substrate for thrombin, glycoprotein V (GPV), because a GPV antigen was reported to be present in plasma (3). Plasma fractionation based on procedures for purification of GPV from platelets revealed a thrombin-sensitive protein with appropriate electrophoretic mobility. The protein was purified; an antiserum against it i) reacted with detergent-solubilized platelet proteins or secreted proteins in a double diffusion assay, ii) adsorbed a protein from the supernatant solution of activated platelets, and iii) inhibited thrombin-induced platelet activation, but the antiserum did not adsorb labeled GPV. The purified protein was immunochemically related to prothrombin rather than to GPV. Other antibodies against prothrombin were also able to adsorb a protein from platelets. It is concluded that 1) plasma does not contain appreciable amounts of GPV, and 2) platelets contain prothrombin or an immunochemically similar protein.

NUMERICAL AND EXPERIMENTAL INVESTIGATION OF PASSIVE HEAT REMOVAL FROM POROUS BED IN PATH FACILITY

2018 ◽  
Author(s):  
Anil Kumar Sharma ◽  
Venkateswarlu S ◽  
E Hemanth Rao ◽  
B Malarvizhi ◽  
S S Murthy ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Heat Removal ◽  
Porous Bed
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