Diffusion in multilayer media: Transient behavior of the lateral diffusion coefficient

2006 ◽  
Vol 124 (15) ◽  
pp. 154710 ◽  
Author(s):  
Alexander M. Berezhkovskii ◽  
George H. Weiss
Keyword(s):  
Diffusion Coefficient ◽  
Lateral Diffusion ◽  
Transient Behavior ◽  
Lateral Diffusion Coefficient ◽  
Multilayer Media

Centerband-only-detection-of-exchange 31P nuclear magnetic resonance and phospholipid lateral diffusion: theory, simulation and experiment

2015 ◽  
Vol 17 (38) ◽  
pp. 25160-25171 ◽  
Author(s):  
Angel Lai ◽  
Qasim Saleem ◽  
Peter M. Macdonald
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Liquid Crystalline ◽  
Diffusion Theory ◽  
Lateral Diffusion ◽  
Liquid Crystalline Phases ◽  
Simulation And Experiment ◽  
Spherical Vesicles ◽  
Lateral Diffusion Coefficient

Theory of CODEX 31P NMR lateral diffusion coefficient measurements on phospholipids in spherical vesicles is described and used to simulate experimental results on DMPC in both the gel and liquid-crystalline phases.

scholarly journals On the Theory of Electron Diffusion in Electrostatic Fields in Gases

1974 ◽  
Vol 27 (2) ◽  
pp. 195 ◽  
Author(s):  
HR Skullerud
Keyword(s):  
Diffusion Coefficient ◽  
Boltzmann Equation ◽  
Diffusion Equation ◽  
Diffusion Tensor ◽  
Lateral Diffusion ◽  
Mean Square ◽  
Electrostatic Fields ◽  
The Mean ◽  
Lateral Diffusion Coefficient

The motion of electrons in a gas in the presence of large electron density gradients has been studied theoretically, starting from the two-term expansion of the Boltzmann equation. The effects of material boundaries have not been considered. An electron swarm released as a b-function in space and with an equilibrium energy distribution is found initially to develop as a spheroid with dimensions determined by the lateral diffusion coefficient. It subsequently passes through a stage involving a slowly decaying pear-shaped deformation, before ultimately becoming an ellipsoid with dimensions determined by the longitudinal and lateral components of the diffusion tensor. Numerical values cited in the literature for the long-term deviations from the mean square widths predicted by the diffusion equation have been found to be in error by factors of 10 or more.

The Impact of Parameterized Lateral Mixing on the Antarctic Circumpolar Current in a Coupled Climate Model

2020 ◽  
Vol 50 (4) ◽  
pp. 965-982 ◽  
Author(s):  
Sarah Ragen ◽  
Marie-Aude Pradal ◽  
Anand Gnanadesikan
Keyword(s):  
Diffusion Coefficient ◽  
Wind Stress ◽  
Antarctic Circumpolar Current ◽  
Climate Model ◽  
Lateral Diffusion ◽  
Intermediate Waters ◽  
Circumpolar Current ◽  
The Antarctic ◽  
The Impact ◽  
Lateral Diffusion Coefficient

AbstractThis study examines the impact of changing the lateral diffusion coefficient ARedi on the transport of the Antarctic Circumpolar Current (ACC). The lateral diffusion coefficient ARedi is poorly constrained, with values ranging across an order of magnitude in climate models. The ACC is difficult to accurately simulate, and there is a large spread in eastward transport in the Southern Ocean (SO) in these models. This paper examines how much of that spread can be attributed to different eddy parameterization coefficients. A coarse-resolution, fully coupled model suite was run with ARedi = 400, 800, 1200, and 2400 m2 s−1. Additionally, two simulations were run with two-dimensional representations of the mixing coefficient based on satellite altimetry. Relative to the 400 m2 s−1 case, the 2400 m2 s−1 case exhibits 1) an 11% decrease in average wind stress from 50° to 65°S, 2) a 20% decrease in zonally averaged eastward transport in the SO, and 3) a 14% weaker transport through the Drake Passage. The decrease in transport is well explained by changes in the thermal current shear, largely due to increases in ocean density occurring on the northern side of the ACC. In intermediate waters these increases are associated with changes in the formation of intermediate waters in the North Pacific. We hypothesize that the deep increases are associated with changes in the wind stress curl allowing Antarctic Bottom Water to escape and flow northward.

Altered behaviour of carbohydrate-bound molecules and lipids in areas of the tegument of adult Schistosoma mansoni worms damaged by praziquantel

Parasitology ◽  
1994 ◽  
Vol 109 (4) ◽  
pp. 469-477 ◽  
Author(s):  
S. F. Lima ◽  
L. Q. Vieira ◽  
A. Hardert ◽  
J. R. Kusel
Keyword(s):  
Diffusion Coefficient ◽  
Schistosoma Mansoni ◽  
Surface Properties ◽  
Fluorescent Probes ◽  
Lateral Diffusion ◽  
Praziquantel Treatment ◽  
Fluid Properties ◽  
Altered Surface ◽  
Mobile Fraction ◽  
Lateral Diffusion Coefficient

SUMMARYBy using fluorescent probes the distribution and fluid properties of lipid and saccharide-bound molecules was assessed in the tegument of praziquantel (−) treated Schistosoma mansoni adult male worms. Our results show that higher amounts of glycoproteins and/or glycolipids are exposed in damaged areas of the membrane compared with undamaged ones. At damaged regions these molecules present high lateral diffusion coefficient and mobile fraction values which suggests that after praziquantel(−) treatment they are being shed by the worm into the medium. The lateral diffusion coefficient of the lipid analogue 5'-octadecanoyl aminofluorescein is unchanged in damaged or undamaged areas but the mobile fraction is significantly reduced at damaged areas. The immunological significance of these altered surface properties is discussed.

scholarly journals The ratio of the lateral diffusion coefficient to mobility for electrons in argon at 294 K

1982 ◽  
Vol 35 (1) ◽  
pp. 105 ◽  
Author(s):  
HB Milloy ◽  
RW Crompton
Keyword(s):  
Diffusion Coefficient ◽  
Pressure Dependence ◽  
Pressure Gauge ◽  
Lateral Diffusion ◽  
Lateral Diffusion Coefficient

An error has been found in the calibration of the pressure gauge used for our experiments. The correction for this error has two consequences: an adjustment of all values in the published Table 1 by an amount ranging from 1.5 % to 0.7 %, and the elimination of the small (<1 %) pressure dependence exhibited by the data in the table and referred to on page 58.

Determination of the lateral diffusion coefficient of potassium oleate in the lamellar phase

1976 ◽  
Vol 64 (4) ◽  
pp. 1848-1849 ◽  
Author(s):  
Stephen B. W. Roeder ◽  
E. Elliott Burnell ◽  
An‐Li Kuo ◽  
Chas. G. Wade
Keyword(s):  
Diffusion Coefficient ◽  
Lateral Diffusion ◽  
Lamellar Phase ◽  
Potassium Oleate ◽  
Lateral Diffusion Coefficient
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