Spill-over region

The jellium double layer is highly polarizable and should not be compared with the classical parallel-plate capacitor. For instance, the thickness of the double layer changes with the charge density. An infinitesimal negative charge density da (<0) on the surface leads to an extension of the spill-over region and an increase in the surface potential dhfM =

0, hence Cm < 0 The double layer of the metal surface has a considerable influence on the structure of the electrochemical double layer. It will also become clear that several features of the electrochemical double layer at a metal can only be understood if the metal surface dipole is taken into account. 

Figure 16. Schematic repmsentation of an electrochemical double layer at a mctal/elcctrolytc solution interface, (a) The jcllium double layer (with electron spill-over region contacts a layer of (ordered) solvent molecules, chemisorption of a negative ion is also shown, (b) Representation of the double layer capacitance as a series connection of the capacitance corresponding to the double layer of the metal surface, and the capacitance of (he Helmholtz layer al the solution side.

Physiological studies have identified both post- and presynaptic roles for ionotropic kainate receptors. Kainate receptors contribute to excitatory post-synaptic currents in many regions of the CNS including hippocampus, cortex, spinal cord and retina. In some cases, postsynaptic kainate receptors are codistributed with AMPA and NMDA receptors, but there are also synapses where transmission is mediated exclusively by postsynaptic kainate receptors for example, in the retina at connections made by cones onto off bipolar cells. Extrasynaptically located postsynaptic kainate receptors are most likely activated by spill-over glutamate (Eder et al. 2003). Modulation of transmitter release by presynaptic kainate receptors can occur at both excitatory and inhibitory synapses. The depolarization of nerve terminals by current flow through ionotropic kainate receptors appears sufficient to account for most examples of presynaptic regulation however, a number of studies have provided evidence for metabotropic effects on transmitter release that can be initiated by activation of kainate receptors. The hyperexcitability evoked by locally applied kainate, which is quite effectively reduced by endocannabinoids, is probably mediated preferentially via an activation of postsynaptic kainate receptors (Marsicano et al. 2003). 

Material spills over the shaft back into the previous pitch space due to the lowering of the effective angle of the central region of the flight from below the angle of slip. 

There are two more aspects of the FTIR study shown in Fig. 2.20(b), which merit comment. First, the carbonate region (1750-1000 cm ) of the spectra is also modified by the chemisorption of Hg on Au/CZ, which suggests that the adsorbed carbonate species present in the sample may also act as a trap for the spilled-over hydrogen. Second, in parallel with the onset of the t)-OH bands, there is an additional peak at 2133 cm f In accordance with earlier studies, this band is assigned to a forbidden electronic transition Fg/g -> F7/2 in The band at 2126 cm" reported in... 

Schematic of the energy bands of a double heterojunction laser. The Fermi level is above the conduction band edge in the n-AlGaAs and below the valence band in the p-GaAs. Forward biasing the junction (below) causes the electrons to spill over into the active p-GaAs region where they are confined by the higher bandgap AlGaAs. The confined inverted population in the active region promotes stimulated emission.

Parker H D and Cormack D (1984) Evaluation of Infrared Line Scan (IRLS) and Side Looking Airborne Radar (SLAR) over controlled oil spills in the North Sea, in Remote Sensing for Control of Marine Pollution, Jean-Marie Massin ed., NATO-Challenges of Modem Society Vol. 6, pp 237-256 REMPEC For the Regional Marine Pollution Emergency Response Centre for the Mediterranean Sea (REMPEC) see http //www.rempec.org... 

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