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Optische Methode zur Bestimmung von Diffusionskoeffizienten
Author(s) -
van Tets A.,
Günthard Hs. H.
Publication year - 1961
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19610440522
Subject(s) - chemistry , slab , diffusion , phase function , transformation (genetics) , absorption (acoustics) , phase (matter) , surface (topology) , thermodynamics , optics , geometry , physics , radiative transfer , biochemistry , mathematics , organic chemistry , geophysics , gene
A method for determination of surface and bulk diffusion coefficients from measurements of optical density on thin slabs is discussed. In principle the spectral absorption of a substance diffusing from gaseous phase into the slab is measured as a function of time. The limitations of the method and the problem of determination of the diffusion coefficients through the surface and inside the slab are discussed and several methods, including the use of time derivatives of optical density, numerical L APLACE transformation and successive approximation by least squares are given. Explicit formulae, numerical tables and curves for the relevant functions are given which might be useful in practical applications of the method.