Pulsed electric field strength

Essentially, this method is based on subjecting cell membranes to a short external electric field pulse of an intensity comparable to the electric field strength of the membrane 77). Under these conditions the membrane breaks down locally and becomes permeable. This process is reversible, i.e. the membrane reconstitutes its original properties in time intervals which can be experimentally controlled. 

Figure 7.6 Bursting of charged vesicles subjected to electric pulses. The time after the beginning of the pulse is marked on each image, (a) Phase contrast microscopy snapshots from fast-camera observation of a vesicle in salt solution subjected to a pulse with field strength of 120kVm and duration of 200ps. The field direction is indicated in...

McDonald, C.J., Lloyd, S.W., Vitale, M.A., Petersson, K., and Innings, E. 2000. Effects of pulsed electric fields on microorganisms in orange juice using electric field strengths of 30 and 50kV/cm. Journal of Pood Science 65 984—989. 

Zhang, Q.H., Qin, B.-L., Barbosa-Canovas, G.V., and Swanson, B.G. 1995b. Inactivation of Escherichia coli for food pasteurization by high-strength pulsed electric fields. Journal of Food Processing and Preservation 19 103-118. 

Consider the decrease of the number of ions in a liquid as a function of time after an instantaneous pulse of radiation. The ions that undergo geminate neutralization move together under the influence of their mutual electric field. The relative velocity v of a pair of ions with respect to each other is negative and is given by the negative product of the electric field strength between them and the sum of their mobilities ... 

Most of the experiments discussed in this book are performed using continuous wave or nanosecond-pulsed lasers at I < 109 W/cm2 intensities, which correspond to electromagnetic radiation electric field strengths of < 9 x 105 V/cm. Such electric fields are weak relative to typical intramolecular field strengths, ° = 1 a.u. = 5.14 x 109 V/cm and are appropriately treated perturbatively (see Sections 6.1.2 and 6.5.3). 

Figure 4 The ratio R of the fraction of CFjHCl dissociated by i.r. MPD per laser pulse in the irradiated volume with and without the electric field, as a function of the laser fluence (Jcm ). The electric field strength vva. 4.2 kVcm" CFjHCl pressure 300mTorr...

The electric field strength at a distance x from the anode is proportional to Hx. If the applied voltage of a cylindrical chamber of 1 cm radius is 1000 V, the pot tial in die immediate vicinity of a center wire of 0.0025 cm diameter is approximately 7 X 10 V cm. As the primary electrons reach the vicinity of this high field and increase their kinetic energy, they cause secondary ionization which increases the pulse detected at the wire anode. The collected charge is given by (8.2), where a, the gas multiplication factor, is > 1. 

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