Parallel Current Paths Research Articles

Voltammetry and coulometry with immersed thin layer electrodes—I. Model for effects of solution resistivity in linear sweep voltammetry

A model for the resistance-induced potential distribution at thin layer electrodes during linear sweep voltammetric experiments is considered and results of calculations based on this model are presented. It is shown that cell geometry is an extremely important factor in determining the extent to which linear sweep voltammograms are affected by solution resistivity. Cell geometries providing for a radially uniform current path are superior to those where a parallel current path exists. Other important factors include electrode area and placement of the Luggin capillary.

Grain boundaries and ionic conduction in sodium beta alumina

Grain boundary morphology and structure has been examined by means of transmission electron microscope lattice imaging, and a plausible correlation is advanced between the grain boundary structure and its transgranular ionic resistivity and capacitance. The geometrical aspects and resistance of the grain boundaries depend on whether or not dislocations with ab=1 spinel block can accommodate the misorientation. Such dislocations are shown to exist in a wide range of grain boundaries. The wide spread in grain boundary structure and the complexity of the microstructure, making parallel current path considerations necessary, can account qualitatively for the deviation from the ideal Maxwell dispersive behaviour. However, a physically relevant interpretation of equivalent circuit parameters determined from dispersive type measurements seems not justified. Several model circuits are used to illustrate the interpretational difficulties. The structure and effects of intergranular phases also have been studied and are discussed.

エレクトロスラッグ溶接法

1,217,877. Welding by fusion. MITSUBISHI JUKOGYO K.K. 13 Sept., 1968, No. 43797/68. Heading B3R. In electroslag welding using an electrode at least part of which is consumed during welding, the electrode, which is of steel plate, comprises a plurality of substantially parallel and coplanar branches 7a, 7b connected together (Fig. 4), or a plurality of separate substantially parallel and coplanar component electrodes (14, 15), (Fig. 7, not shown), electrically connected across the width of the plurality whereby a plurality of parallel current paths are produced through the weld pool, adjacent electrode branches or component electrodes being separated by a gap which is of such width that the thickness of the weld 13 produced is a maximum in the centre of the width thereof (Fig. 6). In the instance that separate component electrodes are used, each of these may be divided into a plurality of parallel and co-planar branches separated by gaps. Edges of the weld may be cooled, as at 6, 6 1 .