Role of migration

Sverjensky, D. A., 1987, The role of migrating oil field brines in the formation of sediment-hosted Cu-rich deposits. Economic Geology 82, 1130-1141. 

Bis-(trifluoromethyl)-phenyl plays the role of migrating ring in the Smiles rearrangement in the Najera and co-workers [106,107] modification of the olefination reaction. Judka and Makosza (Judka and Makosza, 2006, personal commimication) have shown that pentachlorophenyl and some very simple phenyl derivatives may be conveniently used in the olefination reactions imder mild conditions. Indubitably, several other aromatic and hete-rocycHc systems will be estabhshed as the templates in the direct olefination reaction, allowing for convenient choice of experimental conditions and stereochemical bias. 

Hatten ME. 1993. The role of migration in central nervous system neuronal development. Curr Opin Neurobiol 3 38-44. 

In case b it can be shown [1] that the convective diffusion of ions occurs in the same way as that of neutral molecules if effects of the order C1/C3 are neglected. Here Ci designates the concentration of the reacting ions, C3 is the concentration of the foreign electrolyte. The presence of foreign electrolyte reduces the role of migration. 

Sverjensky DA (1987) The role of migrating oil field brines in the formation of sediment-hosted Cu-rich deposits. Econ Geol 82 1130-1141 Sverjensky DA (1989) Chemical evolution of basinal brines that formed sediment-hosted Cu-Pb-Zn deposits. In Boyle RW, Brown AC, Jefferson CW, Jowett EC, Kirkham RV (eds) Sediment-hosted stratiform copper deposits. Geol Assoc Can Spec Pap 36 127-134... 

Lee MC, Choi W (2002) Solid phase photocatalytic reaction on the soot/Ti02 interface the role of migrating OH radicals. J Phys Chem B 106(45) 11818-11822... 

The explicit mathematical treatment for such stationary-state situations at certain ion-selective membranes was performed by Iljuschenko and Mirkin 106). As the publication is in Russian and in a not widely distributed journal, their work will be cited in the appendix. The authors obtain an equation (s. (34) on page 28) similar to the one developed by Eisenman et al. 6) for glass membranes using the three-segment potential approach. However, the mobilities used in the stationary-state treatment are those which describe the ion migration in an electric field through a diffusion layer at the phase boundary. A diffusion process through the entire membrane with constant ion mobilities does not have to be assumed. The non-Nernstian behavior of extremely thin layers (i.e., ISFET) can therefore also be described, as well as the role of an electron transfer at solid-state membranes. 

The role of disorder in the photophysics of conjugated polymers has been extensively described by the work carried out in Marburg by H. Bassler and coworkers. Based on ultrafast photoluminescence (PL) (15], field-induced luminescence quenching [16J and site-selective PL excitation [17], a model for excited state thermalizalion was proposed, which considers interchain exciton migration within the inhomogenously broadened density of states. We will base part of the interpretation of our results in m-LPPP on this model, which will be discussed in some detail in Sections 8.4 and 8.6. 

Jacobs et al. [59,925,926] (Fig. 17). While this scheme conveniently summarizes many features of the observed behaviour, a number of variations or modifications of the mechanisms indicated have been proposed. Maycock and Pai Vemeker [924,933] emphasize the possible role of point defects and suggest, on the evidence of conductivity measurements, that the initial step may be the transfer of either a proton or an electron. Boldyrev et al. [46] suggest that proton conduction permits rapid migration of HC104 within the reactant and this undergoes preferential decomposition in distorted regions. More recently, the ease of proton transfer and the mobilities of other species in or on AP crystals have been investigated by a.c. [360] and d.c. [934] conductivity measurements. Owen et al. [934] could detect no surface proton conductivity and concluded that electron transfer was the initial step in decomposition. At the present time, these inconsistencies remain unresolved. 

This study, in conjunction with that discussed in 12.2.1.2, show that when using aqueous electrolytes or Nafion saturated with H20, the induction of NEMCA on finely dispersed noble metal catalysts is rather straightforward. The role of the electronically conducting porous C support is only to conduct electrons and to support the finely dispersed catalyst. The promoting species can reach the active catalyst via the electrolyte or via the aqueous film without having to migrate on the surface of the support, as is the case when using ceramic solid electrolytes. 

In the theoretical treatment of ion exchange polymers the roles of charge propagation and of migration of ions were further studied by digital simulation. Another example of proven 3-dimensional redox catalysis of the oxidation of Ks[Fe(CN)5] at a ruthenium modified polyvinylpyridine coated electrode was reported... 

The time-dependent nature of migration and chemical reaction of free radicals [30] in irradiated polymers can play an important role in altering the polymer structure and properties, e.g., cross-link formation via reactive sites or chain scission, or postirradiation oxidative influences (irradiation in presence of air or oxygen). 

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