High-intensity electric field

Ade-Omowaye BIO, Rastogi NK, Angersbach A and Knorr D. 2002. Osmotic dehydration of bell peppers influence of high intensity electric field pulses and elevated temperature treatment. J Food Eng 54 35—43. Ajlouni S, Kremer S and Masih L. 2001. Lycopene contents in two different tomato cultivars. Food Aust... 

Rastogi, N.K., Eshtiagi, M.N., and Knorr, D. 1999. Accelerated mass transfer during osmotic dehydration of high intensity electrical field pulse pretreated carrots. J. Food Sci. 64, 1020-1023. 

There is a modest increase in the electrical conductance with an increase in the electric-field gradient, an effect that operates with both strong and weak electrolytes (the first Wien effect). More important in the present context is the marked increase in electrical conductance of weak electrolytes when a high-intensity electric field is applied (second Wien effect). The high field promotes an increase in the concentration of ion pairs and free ions in the equilibrium... 

An important advantage of two-dimensional methods is the solitary migration of each fraction on its own path. In contrast with unidimensional or zone electrophoresis where each fraction migrates its own distance but over a common path, no contamination of fractions is possible (Fig. 40). If the substrate is sufficiently long and wide and a high intensity electrical field is applied, it becomes possible to separate fractions reasonably completely from each other. If the physical forces involved are deployed skillfully, the electrical field can be driven up so that rapid and wide separations are obtained. This point is especially important in star electrophoresis, whereas in collecting electrophoresis mastery of the physical forces provides an excellent continuous preparative tool. 

Note that the configurations in Figure 20 involve point electrodes. To initiate a pulsed discharge in water, it is necessary to have a high-intensity electric field (107-109 V m ) at the tip of the electrode. Proper insulation of the electrode is essential, because water is much more conductive than air. A small protrusion of the point electrode from the insulator surface... 

Various poups have in recent years studied the possibility of inducing the cationic polymerisation of undiluted liquid monomers by the effect of high-intensity electric fields. Two basic principles have been plied to obtain bare cation radicals as primary intermediates in these processes ... 

When a molecule is subjected to laser light (that is—very high intensity electric field), its polarizability can change and be driven beyond the normal regime. Therefore, the polarization, which is a function of the applied field and leads to nonlinear effect, can be expressed as. 

Expression of the therapeutic protein is enhanced by electroporation - the application of a small amount of electricity at the site of injection for a few milliseconds. This high-intensity electric field induces temporary and reversible breakdown of the plasma membrane allowing plasmids and other molecules to gain intracellular access [110]. This plasmid-based PA-inducible transgene regulating... 

In the absence of an electrical field and in dilute solutions, the degree of ionic selectivity depends solely on the physico-chemical properties of the membrane, but in the presence of a high intensity electrical field and the resultant large field gradients in concentrated solutions, the dynamic properties of both the membrane and solution interact with the imposed electrical field to provide the anomalous permselectivity observed. 

DEP force. The frequency dependence and the direction of the DEP force are governed by the real part of the Clausius-Mossotti factor. If the particle is more polarisable than the medium, (Re[/cm] > 0). the particle is attracted to high intensity electric field regions. This is termed as positive dielectrophoresis (pDEP). Conversely, if the particle is less polarisable than the medium, (Re[/cm] < 0), the particle is repelled from high intensity field regions and negative dielectrophoresis (nDEP) occurs. Therefore the real part of the Clausius-Mossotti factor characterizes the frequency dependence of the DEP force, as demonstrated in Fig. 1. 

In a dielectric interface, like the DDL, the material tends to undergo densifica-tion in regions of high-intensity electrical field, as sketched in Figure 2.11. This is an irreversible process known as electrostriction. Here, the phenomenon of elec-trostriction is thought to play a role for DDL to react as a capacitor when an external potential is applied to clay-electrolyte systems. The analogy of electrostriction in dielectric materials is analogous to volumetric compression of mechanical systems. 

The Electrophoretic Displays make use of the migration of Charged pigment particles, suspended in an inert solvent (generally a solvent of class 7) which contains a contrasting Application of a high intensity electric field drivra the... 

High-intensity electric field pulses accelerated osmotic dehydration of carrot [18], A Fickian diffusion coefficient for water and solute increased exponentially with electric field strength. This effect was attributed to increased cell wall permeability, which was also manifested by the softening of product. 

The relatively high surface/volume ratio of the separation compartment ensures efficient Joule heat transfer from the separation space, which allows application of high-intensity electric fields, up to 1000 Vcm resulting in fast and highly efficient separations of analytes. 

Field desorption (FD) is perhaps the simplest technique, the sample is coated as a thin film onto a special filament placed within a very high intensity electric field. Ions created by field-induced removal of an electron from the molecule are extracted into the mass spectrometer. Field ionization (FI) is the equivalent process whereby gas-phase molecules are ionized by a high electric potential. These techniques are sometimes applied to relatively large, polymeric molecules but are not commonplace. 

Jones JL, Jones RE, Balasky G. Microlesion formation in myocardial cells by high-intensity electric field stimulation. Am J Physiol 1987 253 H480-6. 

The cation is more reactive than the free radical, thereby dominating the initiation reaction. Radical cations can also he formed by high energy electrons, vacuum UV radiation, high intensity electric fields, or anodic oxidation of the monomer. Nuclear chemical initiation involves the use of tritium this method produced very high molecular weight polyisobutylenes and polystyrenes (65). 

Essentially, this method is based on subjecting cell membranes, in which high intensity electrical fields occur naturally, to a short external electric field pulse of comparable intensity. Under these conditions the membrane breaks down locally and becomes permeable. This process is... 

Knorr, D Angersbach, A., 1998. Impact of high-intensity electric field pulses on plant membrane permeabiUzation. Trends Food Sci. Technol. 9 185-191. 

Taiwo, K. A., Angersbach, A., Knorr, D., 2002. Influence of high intensity electric field pulses and osmotic dehydration on the rehydration characteristics of apple slices at different temperatures. J. Food Eng. 52 185-192. 

Accelerated mass transfer during osmotic dehydration of high intensity electrical field pulse pretreated carrots. f Food Sci. 64 1020-1023. 

One can interpret the images shown in Figure 13.7 as a topology change of the vesicle when submitted to high intensity electric fields. Such interpretation was... 

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