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Sensitization potential dependence

VII. OXIDES AND SENSITIZATION CELLS 1. Potential Dependence of Interfacial Rate Constants... [Pg.510]

Methyl rotors pose relatively simple, fundamental questions about the nature of noncovalent interactions within molecules. The discovery in the late 1930s1 of the 1025 cm-1 potential energy barrier to internal rotation in ethane was surprising, since no covalent chemical bonds are formed or broken as methyl rotates. By now it is clear that the methyl torsional potential depends sensitively on the local chemical environment. The barrier is 690 cm-1 in propene,2 comparable to ethane,... [Pg.158]

Thus, besides being sensitive to absorbing species on the electrode surface as well as in the solution in the region very close to the surface, it is possible to obtain potential dependent behavior in fine detail. We have applied these techniques to examine the interaction of simple ions such as CN and Ny with polycrystalline electrodes of silver, gold and copper. The observed vibrational spectra can be interpreted with the help of selection rules based on symmetry and analysis of ab-initio SCF wavefunctions of clusters. The results of these studies will be reviewed. [Pg.322]

The LLNA is the preferred method when compared to the GPMT because (a) it can equivalently predict human contact dermatitis, (b) a dose-response can be obtained, and (c) it is in line with current animal welfare efforts. Nevertheless, several situations exist where the GPMT is advantageous, depending predominantly on the choice of test substances. The LLNA is known for less powerful detection of the sensitization potential of metallic compounds, high molecular weight proteins, strong irritants, and for substances with low adhesion to the skin surface (skin wettability is a prerequisite for the successful application of LLNA) [136-140],... [Pg.21]

In addition to examining the surface structure, the STM may also be used as a transducer to monitor deformation associated with potential dependence of the surface stress and associated electrocapillary phenomena at solid electrodes. In this instance, the high z-sensitivity of the STM is used to follow the minute displacements of a surface, which is supported in a cantilever geometry [54,55],... [Pg.256]

Sensitivity Potential Limited, Depending on Resolution Aspect Ratio Requirements Less Limited than ILRs, Depending on Special Resist Combinations Most Unlimited, Only Limited by AvailABLE Resist Sensitivity... [Pg.344]

We have seen in previous sections that the determination of the potential dependence of a is a very powerful tool in the study of dissociative ETs. a is obtained from the experimental activation/driving force plots and, being a derivative, is also particularly sensitive to changes in the slope of these plots. [Pg.129]

Another technique which has much potential in analysis, but which to date has had only limited use, is the formation of radioactive derivatives of non-radioactive compounds for quantitation by radiocounting. A radiolabeled reagent is used to form the derivative. This approach has been of use in combination with chromatography. The advantage of this technique is that it avoids problems of sample background which are often associated with spectrophotometric methods. The 14C-methylation of carboxylic acids and the 14 C-acetylation of hydroxyl groups have been studied [39,40]. These methods are quantitative and the sensitivity is dependent on the activity of the radioactive group added to the molecules. The radioactive derivatization of lipids has been reviewed [41]. [Pg.29]

The application of surface-enhanced Raman spectroscopy (SERS) for monitoring redox and other processes at metal-solution interfaces is illustrated by means of some recent results obtained in our laboratory. The detection of adsorbed species present at outer- as well as inner-sphere reaction sites is noted. The influence of surface interaction effects on the SER spectra of adsorbed redox couples is discussed with a view towards utilizing the frequency-potential dependence of oxidation-state sensitive vibrational modes as a criterion of reactant-surface electronic coupling effects. Illustrative data are presented for Ru(NH3)63+/2+ adsorbed electrostatically to chloride-coated silver, and Fe(CN)63 /" bound to gold electrodes the latter couple appears to be valence delocalized under some conditions. The use of coupled SERS-rotating disk voltammetry measurements to examine the kinetics and mechanisms of irreversible and multistep electrochemical reactions is also discussed. Examples given are the outer- and inner-sphere one-electron reductions of Co(III) and Cr(III) complexes at silver, and the oxidation of carbon monoxide and iodide at gold electrodes. [Pg.135]

The sensitivity of the heterogeneous electron transfer rate constant to the overpotential depends on the extent of electronic coupling between the reactant and the electrode [19]. For strongly coupled reactants, electron transfer occurs predominantly through states near the Fermi level of the electrode and the adiabatic potential-dependent rate constant is given by the product of the frequency factor, vn, and the density of acceptor states in the molecule, Dox, according to the following ... [Pg.37]


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See also in sourсe #XX -- [ Pg.311 ]

See also in sourсe #XX -- [ Pg.356 ]




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Potential Dependence of Sensitization Currents

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