Electrical peak voltage

The theory and appHcation of SF BDV and COV have been studied in both uniform and nonuniform electric fields (37). The ionization potentials of SFg and electron attachment coefficients are the basis for one set of correlation equations. A critical field exists at 89 kV/ (cmkPa) above which coronas can appear. Relative field uniformity is characterized in terms of electrode radii of curvature. Peak voltages up to 100 kV can be sustained. A second BDV analysis (38) also uses electrode radii of curvature in rod-plane data at 60 Hz, and can be used to correlate results up to 150 kV. With d-c voltages (39), a similarity rule can be used to treat BDV in fields up to 500 kV/cm at pressures of 101—709 kPa (1—7 atm). It relates field strength, SF pressure, and electrode radii to coaxial electrodes having 2.5-cm gaps. At elevated pressures and large electrode areas, a faH-off from this rule appears. The BDV properties ofHquid SF are described in thehterature (40—41). 

The power demand of electrolysers and power outputs of oxy-hydrogen turbines can be changed very rapidly compared to traditional peak-electricity production technologies. Consequently, these systems can be used for power regulation to produce higher quality electricity (constant voltage and frequency). This is a very high value utility service. 

A mercury atom that was ionized by a weak electron beam was captured in a miniature Paul (radio frequency) trap that has internal dimensions of rQ s 466 pm and zQ s 330 pm. The rf trapping frequency was 21.07 MHz with a peak voltage amplitude of about 730 V. The ion was laser cooled by a few microwatts of cw laser radiation that was frequency tuned below the 6s Si -6p Pi electric dipole transition near 194 nm. When the Hg+ ion was cold and the 194 nm radiation had sufficient intensity to saturate the strongly allowed S-P transition, 2 x 10 photons/s were scattered. With our collection efficiency, this corresponded to an observed peak count rate of about 10 s-1 against a background of less than 50 s— -. 

In a mass spectrometer, positive ions are produced when a gaseous mixture is ionized by electron bombardment produced by an electric discharge. When the electric-discharge voltage is low, singly positive ions are produced and the following peaks are observed in the mass spectrum. 

The coil must be able to sustain a peak current of roughly 20 A and, without electrical breakdown, a peak voltage of 5 kV. 

A typical PEF system consists of a pulse modulator which supplies high-voltage pulses of sufficient peak voltage and repetition rate, and a treatment chamber in which the product is exposed to the electric field. For pumpable media such as fruit juices, milk or fruit mashes, the treatment can be performed continuously in a tubular treatment chamber consisting of cylindrical electrodes. Whole fruits or pieces can be submerged in water in a flume, but a dry PEF treatment with direct contact between the product and the electrodes is desirable for meat pieces, in order to prevent crossFurther information on the principles and mechanisms of action of PEF, as well as its technical aspects and appUcations, are available elsewhere (Lelieveld et al, 2007 Raso and Heinz, 2007). 

Fig. 10 (a) Schematic diagram of fabrication process for electrospun PANI/CA actuators, (b) harmonic responses, (c) hysteresis responses of electrospun actuators under sinusoidal electrical inputs with peak voltage of 3 V and excitation frequency of 0.1 Hz (Hong et aL 2013. 2013 Elsevier Ltd. Reproduced by permission of Elsevier BV. All rights reserved.)... 

One published application of time-resolved asynchronous FT-IR spectrometry involves the reorientation dynamics of ferroelectric liquid crystals induced by the reversal of the external electric field [26,27]. For the study to be described here, the liquid crystals were held in a 2-pm CaFa cell whose windows had been coated with indium tin oxide, which served as the electrode, and with a polyimide film that had been oriented by stroking it in one direction. After the sample had been heated to 90° C to ensure that it was all in the isotropic liquid phase, it was injected into the cell, which had been heated to the same temperature. The cell was then allowed to cool to 40°C at a rate of 1°C min to obtain a homogeneously oriented liquid crystal. An IR polarizer was set at an angle of 45° to the orientation direction of the liquid crystal to obtain the maximum change in the absorption spectrum. Rectangular electric pulses with 20-V peak voltages and a 20-ps period were applied to the cell. 

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