Other phenomena in contrast seem barely accessible to a reaction-diffusion-based description such as the bulk movement in zebrafish lateral line morphogenesis.
Multifold increase in the observed catalytic activity was registered for the catalytic membrane operated with the forced flow of the reaction solution through the membrane, as compared to the value achieved at the same conditions, but in the absence of the forced flow (i.e. when the membrane porous space was accessible to the reactants due to diffusion only).
The porous material property of interest, the available volume fraction, Kav, represents the fraction of space that is accessible to a molecule for diffusion and depends on the molecule's size and matrix fiber composition [71], [72].
As frequency decreases, electrolyte ions by diffusion are accessible to more and deeper porous surface of the PPy nanotube arrays.
Conditions were such that siderophores were beneficial (iron was limiting) and accessible to cheats (liquid growth medium allows free diffusion of siderophores), and cooperation was not under positive social selection (competition was entirely within-patch).
Since covalently bound N might be less accessible to living organisms and less susceptible to volatilization, diffusion, and leaching than weakly sorbed NH3 and NH4+, it would also have very different implications for local N availability and global N cycling.
Given this restriction, how can noncommercial diffusion be simplified to make innovations more accessible to individuals who lack technical skills?
A complete mathematical discussion of diffusion requires partial differential equations and techniques not accessible to most of our target audience.
These models depend on several parameters such as kinetic constants or molecular diffusion constants which are in many cases not accessible to experimental determination.
Biological, fluorescent molecules as small as a few nanometers were accessible to single molecule observation in aqueous solution, and we succeeded to track molecules with a diffusion coefficient of greater than 100 µm2/s.
