Random force migration

The LD can occur in populations as a consequence of a number of factors (see Ref. 13 for review) mutation when a new mutant arises, it occurs in one individual and is in LD with all polymorphic loci in the population selection—either acting directly on the two loci, or transient LD can also be created with neutral loci via a hitchhiking event with a selected locus (14) migration or admixture—generation of LD by these forces requires that the allelic frequencies of both loci in the two populations be different, and this difference must be substantial to generate very much LD and random genetic drift—while the expected value of pairwise LD due to drift over... 

The process of diffusion results from the random walk of ions the process of migration (i.e., conduction) results from the drift velocity acquired by ions when they experience a force. The drift of ions does not obviate their random walk in fact, it is superimposed on their random walk. Hence, the drift and the random walk must be... 

For a grain structure to be in metastable equilibrium the surface tensions must balance at every junction between the GBs. It is theoretically possible to construct a three-dimensional polycrystal in which the boundary tension forces balance at all faces and junctions, but in a real random polycrystalline aggregate there are always going to be boundaries with a net curvature in one direction and thus curved triple junctions. Consequently, a random grain structure is inherently unstable and, on heating at high temperatures, the unbalanced forces will cause the boundaries to migrate toward their center of curvature. 

Therefore, the molar conductivity is a parameter directly linked with the mobility and not with concentration. The basic unit is [S/m] per [mol/m ], or Sm /mol. The mobility, p, is related to the random molecular collisions and corresponding frictional force (viscosity t ) experienced by the migrating ion. The frictional force, f, is ideally related to the hydrodynamic radius, a, of the ion according to Stoke s law ... 

At constant temperature, the gradient of concentration inside a solution (without convection or migration) produces a flow of matter in the opposite direction, which arises from random fluctuations in the positions of molecules in space. This phenomenon, denominated by isothermal diffusion, is an irreversible process. The gradient of chemical potential in the real solution is treated as the true virtual force producing diffusion. 

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