Transport coefficients interdependence

The plot of permeability coefficient versus molecular radius in Figure 10 shows the interdependence of molecular size and electric charge. The permeability of the solutes decreases with increasing size. The protonated amines permeate the pores faster than neutral solutes of comparable size, and the anions of weak acids permeate the pores at a slower rate. The transport behavior of the ionic permeants is consistent with a net negatively charged paracellular route. These results are phenomenologically identical to those found in the transport kinetics of... 

Diffusion in multicomponent system is difficult to analyze. Transport of one component is affected by the presence of the other component due to their mumal interaction. This results in the coupling of fluxes. Thus, single-component diffusion equation cannot be used to predict diffusion in a multicomponent system. Greenlaw et al. [38] proposed a simple relationship in which the diffusion coefficients for components i and j are interdependent on both component concentrations ... 

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