Permeability of a solid

Critical distances [32] of ion stabilization in organic solids for the rectangular, Rrcr, and the Coulomb, Rccr, forms of the barrier for electron tunneling, and critical coefficients, -D, of ion diffusion as functions of the ionization energy, 7d, of the donor, and the static dielectric permeability of a solid,... 

In order to determine the permeability of a solid, a fluid, usually water, is passed through the solid bed or core sample located in a cylindrical autoclave and sealed toward the inner walls of the vessel in order to inhibit leakages (Figure 7.9). In a certain range of mass flow and corresponding pressure drop, a definite value of permeability can be calculated. 

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