Factors influencing electrical conductivity

Several experimental techniques may be used, such as acid/base titration, electrical conductivity measurement, temperature measurement, or measurement of optical properties such as refractive index, light absorption, and so on. In each case, it is necessary to specify the manner of tracer addition, the position and number of recording stations, the sample volume of the detection system, and the criteria used in locating the end-point. Each of these factors will influence the measured value of mixing time, and therefore care must be exercised in comparing results from different investigations. 

Ions in a food oscillate transversely under the influence of the microwave electric field, colliding with their neighboring atoms or molecules. These collisions impart molecular motion which is defined as heat. Materials with mobile ions are conductive. The more available ions in a food, the higher the electrical conductivity. Microwave absorption in a food thus increases with its ionic content. The portion of microwave absorption due to ionic conduction can be described as a portion of the dielectric loss factor, ec. Geyer (1990) recently discussed this concept in his publication. 

The electrical conductivity of the electrolyte is influenced principally by two factors the concentration of additives and the temperature. The influence of... 

The electrical conduction process depends on several parameters, mainly on filler concentration. But filler morphology such as particle size and structure as well as filler-filler and filler-matrix interactions which determine the state of dispersion and filler orientation are key factors in determining the electrical properties. On the other hand, processing techniques also influence the electrical conductivity of... 

Now that we have discussed the CO2 resistances and conductances, we are ready to examine CO2 fluxes. We will do this for photosynthesis, a process that consumes CO2, as well as for respiration and photorespiration, processes that evolve CO2. Our analysis will use an electrical circuit so that we can represent the interrelationships among the various factors influencing net CO2 uptake by a leaf... 

The electric conductivity of carbon nanotubes is largely influenced by the presence of defects. Even effects as modest as axial strain with bond expansion change the band structure. Stone-Wales defects and other imperfections diminish the electric conductivity as well. This effect is especially pronounced for defects with two adjacent vacancies. The resistance of a 400 nm long SWNT, for example, increases by a factor of 1000 if the tube bears as little as 0.03% of these double vacancies. Single vacancies, on the other hand, do not cause such dramatic changes. In any case, however, the free path of the electrons is reduced considerably by the defects (in parts down to a few nanometers). Still, due to the multitude of existing conduction channels, this has no large influence on the overall conductivity. 

In many ways, analysis of the factors influencing biological electron transfer is analogous to the study of electric conduction in macroscopic systems. The properties of conducting systems may be described by Ohm s law ... 

In Sec. 7.3.1, the concept of electrical conductivity is introduced. Now in addition to ionic conductivity, the influence of mobile electronic defects has to be factored into the total conductance. How these electronic defects are introduced in a crystal was first encountered in the previous chapter and is further elaborated in Sec. 7.3.2. 

Two basic contributions are expected to the variation of dielectric properties of a hydrated material with respect to those of a dry one that of the polar water molecules themselves and the second one due to the modification of the various polarization and relaxation mechanisms of the matrix material itself by water [37]. In the low frequency region of measurements, there is a third contribution, often ignored in works dealing with high frequency measurements, which arises from the influence of moisture on conductivity and conductivity effects. The increase of electrical conductivity of the sample is the major effect present in wet samples dielectric response is often masked by conductivity, and it superposes the dielectric processes in the loss spectra and demands a conductivity correction of the dielectric loss spectra [9]. This dc conductivity strongly affects the modifled loss factor, e". In this case, it can be expressed as shown in the following equation ... 

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