Diffusion with memory in two cases of biological interest

摘要: The complexity of a biological structure, such as membrane where the transport process may carry solid particles which obstruct some pores, diminishing their size and making permeability dependent on local structure medium, suggests introduction space-dependent diffusion constant. In this note, profile concentration diffusing solutes inside cell has been calculated basis Fick equation modified by introducing memory formalism (diffusion with memory). This approach employed to describe when sudden change in medium bathing one its face is applied for limited interval time. A further application method concerns so-called boundary layer that occurs at membrane-aqueous interface, solute depends, even considerable depth, interface. These profiles are compared recent experiments concerning ethanol close nephrophane membrane. generalizes models based more complex systems, space-independent coefficient could be inappropriate take into account large variety processes systems.