Skin depth definition

Additionally, Biot (1956a, b) introduced a complex correction function (F) which accounts for a frequency-dependent viscous flow resistance (r /K). In fact, while the assumption of an ideal Poiseuille flow is valid for lower frequencies, deviations of this law occnr at higher frequencies. For short wavelengths the inflnence of pore flnid viscosity confines to a thin skin depth close to the sediment frame, so that the pore fluid seems to be less viscous. To take these effects into account the complex fnnction (F) modifies the viscous flow resistance (p/K) as a fnnction of pore size, pore flnid density, viscosity and freqnency. A complete definition of (F) can be fonnd in Stoll (1989). 

By definition the range of small parameters ai/hi and L/hi corresponds to conditions when the skin depth in every uniform part of the medium is much greater than its geometric parameters, such as the radius of the borehole and the invaded zone, the length of two-coil probe, that is ... 

Attenuation of the electric field by a metal is characterized by the skin depth S. By definition, S = 2/a, where a is the decay constant (1.1.17°). The electric field decreases exponentially by the factor of e over a distance of 5, whereas the light intensity [Poynting vector (1.1.15°)] decreases by the factor of over a distance of S. Equation (1.24) gives... 

There is a definite association between the size of a primary melanoma lesion and the likelihood of metastases. The prognostic factor originally used to determine survival was based on the cross-sectional profile of the primary tumor. The cross-sectional profile could be evaluated if the deepest invasive tumor cells lay above or below the sweat glands. This assessment was further clarified by Clark, who described the relationship of depth of invasion of the cancer cells to the standard anatomic landmarks of the skin (Table 133-3). Clark s classification is a practical approach for patients with more superficial tumors, because tumors classified as Clark levels I through III seldom metastasize. That classification system has been criticized because of problems associated with practical measurements. Melanoma lesions that occur in the presence of lymphoid infiltration, fibrosis, or even the cells of preexisting nevi are difficult to assess with classic reference landmarks. 

Dermatomed skin, in which the lower dermis has been removed to a definite depth... 

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