Cation conduction

Fig. 24. Corrosion rates of carbon steel as a function of oxygen concentration at cation conductivity values of ( ...

This material was first synthesized in the middle 1960s by E.I. Du Pont de Nemours and Co., and was soon recognized as an outstanding ion conductor for laboratory as well as for industrial electrochemistry. The perfluorinated polymeric backbone is responsible for the good chemical and thermal stability of the polymer. Nation membrane swollen with an electrolyte solution shows high cation conductivity, whereas the transport of anions is almost entirely suppressed. This so-called permselectivity (cf. Section 6.2.1) is a characteristic advantage of Nation in comparison with classical ion-exchange polymers, in which the selective ion transport is usually not so pronounced. 

Shen, K Z. North, R. A (1992). Muscarine increases cation conductance and... 

Fesenko, E., Kolesnikov, S. S. and Lyubarsky, A. L. Induction by cyclic GMP of cationic conductance in plasma membrane of retinal rod outer segment. Nature 313 310-313,1985. 

Diffusion in the extrinsic region can readily be modified by doping, although knowledge of the mechanism by which the diffusion takes place is important if this is to be immediately successful. For example, sodium chloride structure materials that conduct by a vacancy mechanism can have the cation conductivity enhanced by doping with divalent cations, as these generate compensating cation vacancies. The inclusion of cadmium chloride into sodium chloride can be written ... 

Ingram, S. L. and Amara, S. G. (2000) Arachidonic acid stimulates a novel cocaine-sensitive cation conductance associated with the human dopamine transporter. J. Neurosci. 20,550-557. 

Examples of some ionic conductivity data. Sum of anionic and cationic conductivities may be used as estimates of salt conductivity... 

Amino Acids Glutamate NMDA, AMPA, kainate Cation conductance... 

Fig. 4.3 Schematic representation of interstitial cationic pair formation (a) and migration from one non bridging oxygen to another in a cation conducting glass (b).

Such a chemical approach which links ionic conductivity with thermodynamic characteristics of the dissociating species was initially proposed by Ravaine and Souquet (1977). Since it simply extends to glasses the theory of electrolytic dissociation proposed a century ago by Arrhenius for liquid ionic solutions, this approach is currently called the weak electrolyte theory. The weak electrolyte approach allows, for a glass in which the ionic conductivity is mainly dominated by an MY salt, a simple relationship between the cationic conductivity a+, the electrical mobility u+ of the charge carrier, the dissociation constant and the thermodynamic activity of the salt with a partial molar free energy AG y with respect to an arbitrary reference state ... 

Figure 4 shows a test of the diagnostic system for an incident of resin exhaustion for a cation conductivity sensor. The data are a combination of real and synthesized plant data and are given in Table IV. The condensate values for the condensate sensor are those recorded during the actual exhaustion of the... 

Table IV. Sensors related to a cation conductivity resin exhaustion incident...

The unavailability of data on dissociation degree and mobility has thus made ion conductivity an alternative metric that has been universally adopted by the battery research and development community to evaluate the transport ability of electrolytes. However, it should always be remembered that such a metric of convenience is based on an unstated assumption that is, the increase in the overall conductivity should originate, at least partially, from the improvement in the cation conductivity. Qualitatively, this assumption holds true, since a correlation does usually exist between ion conductivity and power performance in batteries, although quantitatively the distribution of this increase between anions and cations is unknown. 

Microfabrication Approaches for Small 4472 and Cation-Conductive Electrolytes ... 

Electrodeposition of Dieiectrics—Separators and Cation-Conductive Eiectroiytes... 

Gokel prepared a series of novel bis- and tris(macrocyclic) compounds, which have been designed as models for cation-conducting channels that function in... 

Compound Temperature (°C) Cationic Conductivity ionic Anionic Conductivity ionic total) Electronic Conductivity tytotal)... 

Motoneuron-Renshaw cell synapse Nicotinic nicotine Dihydro-B-erythroidine, a-bungarotoxin Excitatory t cation conductance... 

Glutamate Relay neurons at all levels and some interneurons N- Methyl-D-aspartate (NMDA) NMDA 2-Amino-5- phosphonovalerate, dizocilpine Excitatory t cation conductance, particularly Ca2+... 

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