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Modeling Membrane Permeability in a Coefficient Form PDE Model

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Hello,

I am trying to model diffusion of water through a cell modeled by a circle placed in the surrounding environment modeled by a square. I first tried out the model using natural boundary conditions or "continuity" at the circle boundary (membrane boundary). I would like to now model the membrane to behave more naturally, i.e. have a permeability value. I tried using the Flux/Source Option under Coefficient Form PDE Model but does this place an additional source on the boundary? I am not quite sure how to go about this and would greatly appreciate any help.

Thanks in advance,

Caroline

3 Replies Last Post 20 oct. 2014, 04:14 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 30 mars 2013, 03:28 UTC−4
Hi

there s a good book, unfortunately based on v3.3, its the one of Zimmerman (see the books on COSMOl main web site). I find it fully worth to dig into it and translate the examples to v4. It starts with PDE's and finish with full models (àla COMSOL GUI)

--
Good luck
Ivar
Hi there s a good book, unfortunately based on v3.3, its the one of Zimmerman (see the books on COSMOl main web site). I find it fully worth to dig into it and translate the examples to v4. It starts with PDE's and finish with full models (àla COMSOL GUI) -- Good luck Ivar

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Posted: 1 decade ago 30 mars 2013, 17:51 UTC−4
Thanks! I'll take a look

Caroline
Thanks! I'll take a look Caroline

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Posted: 1 decade ago 20 oct. 2014, 04:14 UTC−4
Hello, has the problem been solved?
I have the same issue with modelling a cell membrane: I have a permeability coefficient, a reflexion coefficient (only 2/3 of the molecules pass through the membrane), and would like to integrate them to my model.

More specifically, I am using Comsol v4.4 and would like to model molecule exchanges (intracellular and between the cells and the nutrient media). I have been using the diluted species transport (chds) module for the regular diffusion/degradation aspects but I haven't found how to integrate the permeability and reflexion parameters (porosity doesn't seem to be the way to go.)

I haven't found answers in the COMSOL publication database, it's quite possible that I missed something. Help would be much appreciated.
Hello, has the problem been solved? I have the same issue with modelling a cell membrane: I have a permeability coefficient, a reflexion coefficient (only 2/3 of the molecules pass through the membrane), and would like to integrate them to my model. More specifically, I am using Comsol v4.4 and would like to model molecule exchanges (intracellular and between the cells and the nutrient media). I have been using the diluted species transport (chds) module for the regular diffusion/degradation aspects but I haven't found how to integrate the permeability and reflexion parameters (porosity doesn't seem to be the way to go.) I haven't found answers in the COMSOL publication database, it's quite possible that I missed something. Help would be much appreciated.

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