Configurational regime

In equations (5) and (6), DM and DK are the molecular and Knudsen diffusivities, respectively, and e and x are the void fraction and the tortuosity of the porous solid, respectively. For pore dimensions significantly larger than the mean free path of the diffusant in the gas phase, the diffusivity is governed by molecular diffusion, but when the pore diameter becomes smaller than the mean free path, diffusion is properly described by Knudsen diffusion. When the pore diameter approaches that of the diffusing species, around 10, one enters the configurational regime. 

The different situations that can be encountered analysing the permeation of molecules through a porous membrane are reported below. When the pore diameter of a porous solid is in the macropore range, collisions between the molecules will occur much more frequently than collisions with the wall. In this case molecular diffusion is the dominant mechanism. As the size of the pores decreases (mesoporous solid), the number of collisions with the wall increases and can become more frequent and important than the molecule-molecule colUsions. At this point, Knudsen diffusion takes over. When the pore diameter becomes comparable to the size of the molecules (microporous solid), the molecules continuously collide with the walls. When this happens, diffusion behaves as an activated process and the term configurational regime is used to describe it. 

It enables first to explain the phenomena that happen in the thin-skin regime concerning the electromagnetic skin depth and the interaetion between induced eddy eurrent and the slots. Modelling can explain impedance signals from probes in order to verify experimental measurements. Parametric studies can be performed on probes and the defect in order to optimise NDT system or qualify it for several configurations. 

Do we expect this model to be accurate for a dynamics dictated by Tsallis statistics A jump diffusion process that randomly samples the equilibrium canonical Tsallis distribution has been shown to lead to anomalous diffusion and Levy flights in the 5/3 < q < 3 regime. [3] Due to the delocalized nature of the equilibrium distributions, we might find that the microstates of our master equation are not well defined. Even at low temperatures, it may be difficult to identify distinct microstates of the system. The same delocalization can lead to large transition probabilities for states that are not adjacent ill configuration space. This would be a violation of the assumptions of the transition state theory - that once the system crosses the transition state from the reactant microstate it will be deactivated and equilibrated in the product state. Concerted transitions between spatially far-separated states may be common. This would lead to a highly connected master equation where each state is connected to a significant fraction of all other microstates of the system. [9, 10]... 

FIG. IS Series of snapshot configurations obtained using lattices of side L = 1024 during the stationary regime of the HS model. (A) Cellular structures, (B) target patterns, (C) double spirals and (D) turbulence. (From Ref. 15.)... 

Flow and power numbers each decrease as the Reynolds number increases. In unbaffled tanks, a vortex forms that takes over the flow regime and does not allow the usual relationship to describe the performance of the mixing operation. It is proper and good practice to provide baffles in all vessels (see later description for the physical configurations). 

Ternary compounds CgBr Cli-j have been synthesized. The configuration having x - 0.55 seems to be especially stable, and the limiting value in the bromine-poor regime is x = 0.33 (Fll). 

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