Migration apparent conductivity

Note that the coefficient a / in the previous formula can now be treated as just a scaling factor, which can be found by minimizing the misfit between the observed and predicted data. Thus, on the basis of expression (11.44), we can introduce the so-called migration apparent conductivity, Aama [x, z),... 

Formula (11.45) plays an important role in fast inverse imaging. We can see from (11.45) that the migration apparent conductivity Aarnaix, z) is proportional (with some constant coefficient ko and weights w ) to the frequency stacked values of the product of the background (incident) field Ey (the field that corresponds to the background distribution of conductivity (Tj x, z)) and the migrated residual field E om, o,u>) — Ey x, o,u)]. We will show in the next sections of this... 

The passive film itself could not be treated as purely insulating since the known thickness of the film should give rise to a capacitive effect that would easily be seen in the impedance diagram. In fact, the film is apparently relatively conducting, probably through proton migration. 

Mg has been studied in a polyelectrolyte system where the counterion is a phosphazene-bound sulphonate group. In this case the finite but low conductivity is due to Mg migration. A large increase in conductivity is noted when a bicyclic ligand, crypt [2.1.1.], is introduced (Hancock and Martell, 1988). Apparently, the cation-anion and cation-polymer interactions are reduced by complex formation, resulting in a more mobile cation, despite its larger effective radius. 

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