This page will look better in a graphical browser that supports web standards, but is accessible to any browser or internet device.

Served by Samwise.


This theoretical model simulates the diffusional transport of fatty acid from a constant source through two unstirred regions separated by a permeable membrane.

Model number: 0135

Run Model: 
    Help running a JSim model.
Java runtime required. Web browser must support Java Applets.
(JSim model applet may take 10-20 seconds to load.)


 Model for albumin-facilitated diffusion of palmitate in plane slab from a plane 
 source (equilibrated) to a planar membrane which palmitate permeates. Same as the 
 1 region model except there are now 2 regions with spatial domains x and y, with 
 duplicated code, the second being suffixed “y” on variables and parameters so that 
 comparisons can be made. The 2 regions are not connected, but this code will serve 
 as the basis for code in which the regions are connected, which reproduces the full 
 model in Barta et al 2000. This model assumes only 1 binding site on albumin, and 
 has adjustable rates and kd. 	


For the full formulation see the paper by Barta et al. But briefly the set of partial differential equations in each of the regions is:

with boundary conditions:
at x=0

at x=xmembrane

and at x=xmax

The equations for this model may also be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.

Download JSim model project file


 Barta, Efrath; Sideman, Samuel; and Bassingthwaighte, James B.;
 Facilitated Diffusion and Membrane Permeation of Fatty Acid in Albumin Solutions, 
 ABME 28: 331-345, 2000	

Related Models

Key Terms

Facilitated diffusion, permeation, Fatty acid, Albumin, Albumin-fatty acid complex, Multiregion, PDE, Publication, Transport Physiology,

Model Feedback

We welcome comments and feedback for this model. Please use the button below to send comments:

Model History

Get Model history in CVS.

Posted by: BEJ


Please cite in any publication for which this software is used and send an email with the citation and, if possible, a PDF file of the paper to:
Or send a copy to:
The National Simulation Resource, Director J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.

[This page was last modified 14Mar18, 3:17 pm.]

Model development and archiving support at provided by the following grants: NIH U01HL122199 Analyzing the Cardiac Power Grid, 09/15/2015 - 05/31/2020, NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.