Fick's law


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Fick's law

Etymology: Adolf E. Fick, German physiologist, 1829-1901
1 (in chemistry and physics) an observed law stating that the rate at which one substance diffuses through another is directly proportional to the concentration gradient of the diffusing substance.
2 (in medicine) an observed law stating that the rate of diffusion across a membrane is directly proportional to the concentration gradient of the substance on the two sides of the membrane and inversely related to the thickness of the membrane.

Fick's law

Diffusion through a tissue membrane is directly proportional to the cross-sectional area, driving pressure, and gas coefficient and inversely proportional to tissue thickness.
References in periodicals archive ?
Observed values of effective diffusivity (Def) for the drying condition analyzed by the Fick's Law model Tests [D.
Under the above assumption, the plasma/nuclear membranes will be replaced by construing membrane flux employing Fick's law of diffusion.
This means that if we replace plasma/nuclear membranes by construing membrane flux employing Fick's law of diffusion, then it has no effect on toxicity level of chemical compounds and therefore detailed spherical model can be replaced by simplified spherical model for less time consumption and computational ease.
Equation 8 is Fick's law of diffusion, written specifically for the electrolyte in a lithium-ion battery.
By neglecting spatial variations in solution concentration, the single particle model is able to: (1) represent each battery electrode by a single spherical diffusion particle (hence the model's name), (2) eliminate the need for solving Fick's law of diffusion for the solution, (3) replace Ohm's law for both the solid and electrolytic media by lumped equivalent resistors.
This initial comparison shows close agreement between loss diffusivity derived from fitting hloss hloss (the humidity-induced change in loss from the dry state) to Fick's law and moisture diffusivity.
Keywords: Epoxy resins, drying, heat and mass transfer, waterborne, aerospace, aircraft, Fick's law
It is known that the partial solution of the one dimensional equation of Fick's law
The other major component of Fick's law is the diameter of the cross-sectional area of the diffusing path.
Since diffusion has been shown to follow Fick's Law for low concentrations of all the penetrants experimentally studied, it is reasonable to assume this will also be true for larger molecules.
Fick's laws shows good agreement with the normalization based on [D.