Conducting gaps

Satomi K, Bansch D, Tilz R, et al. Left atrial and pulmonary vein macroreentrant tachycardia associated with double conduction gaps a novel type of man-made tachycardia after circumferential pulmonary vein isolation. Heart Rhythm 2008 5 43-51. 

Figure 1 gives the essential features for describing the Volta and compensation condenser states. In Figure la two conducting phases, a and / , face each other at a distance x across a non-conducting gap of,... 

Figure 1. Representation of the outer potentials (fain the non-conducting gap between the plane surfaces of two conducting phases, a and (3, separated by a distance, x, and connected to a potentiometer at potential E...

A problem that manifests itself with the use of certain ampholyte ranges and high field strengths is the appearance of "hot spots" (42). These "hot spots" are conductivity gaps in the gradient and serve as a limiting factor for the field strength that may be applied to the gel. 

With sufficiently high field strengths the "hot spots" become burn spots on the gel (19 > 31). This is an undesirable effect, especially when the proteln(s) of Interest has yet to be resolved. The problem can be solved by adjusting one of the electrodes (after a prescribed time into the run) to bypass the area of the gel where the conductivity gap exists. There then will be a shorter inter-electrode wick distance, a more uniform conductance across the gel, no gel burning, and the run can be completed to obtain the desired resolution. This approach has been successfully used for subtyping Go in bloodstains (31). 

Figure 11. (a) The conduction gap observed in small clusters of gold, palladium, cadmium, and silver as a function of cluster volume, (b) Normalized slope of the /-K curves (the conductance) as a fraction of cluster volume for the four metals studied. Above a critical volume of ca 4nm the slope becomes size-independent. This is possibly a direct indication of a size-induced-metal-insulator transition, as indicated. Taken from Vinod et a/. ... 

A special arrangement is the ring-disc electrode which is currently often used for kinetic and mechanistic studies [13]. In this case the rotating disc is surrounded by a ring electrode which is separated by a thin non-conducting gap. 

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