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The paper describes the composition and characteristics of GET 158-2020 State Primary Standard for the electric field strength unit within the frequency range from 0 to 20 kHz. The lower frequency range limit of AC electric field reproduction is extended from 20 Hz to 5 Hz in accordance with regulatory requirements, while the upper limit for the electric field strength (EFS) range amounts to 4000 V/m. The residual systematic error of GET 158-2020 reaches 1.4%; zero electric potential is ensured in the center of a field-generating system. Estimation specifics associated with the symmetric configuration of the standard are considered for the components of residual systematic error and error due to the transfer of the EFS unit, including those associated with the coupling of measuring antennas with the electrodes of field-generating systems. The State Verification Scheme for EFS measuring instruments, taking into account all trends in the development of this type of measurement, was drafted and discussed. [ABSTRACT FROM AUTHOR]

We present analysis of electrostatic waves around the ramp of a quasi‐perpendicular Earth's bow shock observed by the Magnetospheric Multiscale spacecraft. The electrostatic waves have amplitudes up to 800 mV/m, which is the largest value ever reported in the Earth's bow shock. In contrast to previous studies, the electrostatic waves have large amplitudes of the electrostatic potential, up to 20 V or 20% of local electron temperature. The wavelengths are from 150 m to 3 km, that is from 15 to 300 Debye lengths and typically from 0.4 to 1.5 thermal electron gyroradii. Importantly, these waves can propagate not only quasi‐parallel or oblique, but also almost perpendicular to local magnetic field. The electrostatic waves are interpreted in terms of ion‐acoustic waves, although the presence of electron cyclotron harmonic waves cannot be entirely ruled out. These results suggest that electrostatic waves may strongly affect the dynamics of electrons in collisionless shocks. Plain Language Summary: Electrostatic fluctuations are always present around collisionless shocks observed in the heliosphere. However, the effects of these fluctuations on the shock dynamics have not been quantified yet, mostly because experimental studies of their properties are scarce and, moreover, limited to electric field measurements in a spacecraft spin plane. We present analysis of electrostatic waves in a quasi‐perpendicular Earth's bow shock using three‐component electric field measurements aboard the Magnetospheric Multiscale spacecraft. We show that electrostatic waves have rather high amplitudes of the electrostatic potential, wavelengths comparable with thermal electron gyroradius, and can propagate at various angles to local magnetic field, including almost perpendicular propagation. The revealed properties indicate that electrostatic waves may be efficient in pitch‐angle scattering/demagnetization of electrons in collisionless shocks, thereby potentially facilitating electron heating and thermalization. Key Points: Ion‐acoustic waves have electric field amplitudes up to 800 mV/m and electrostatic potential amplitudes up to 20 VThe typical wavelength of ion‐acoustic waves is comparable with thermal electron gyroradiusIon‐acoustic waves can propagate at arbitrary angles to local magnetic field, including almost perpendicular propagation [ABSTRACT FROM AUTHOR]

By measuring the i-v characteristics of Y3N@[C80]6- anionic solid at various temperatures and electric field strengths, four conducting phases with i∞v , i∞v2 with low resistance, i∞v4 and i∞v2 with high resistance were observed. First, at temperatures below 100K and field strengths below 30 Vcm-1, the current passing through the sample was a linear function of the d.c. bias voltage due to free moving charges. Second, at the same field strengths, the trapped carrier was thermally activated with activation energies of 13.6meV for temperature range of 100-250 K and 88.7meV for 250-450 K. In this conducting phase, the carrier transport was governed by space charge limited conduction mechanism. Third, when the electric field increased from 30 to 120 Vcm-1, the i became a quartic function of the v because the carrier mobility is a quadratic function of the field strength. A conducting phase with high resistance was observed at temperatures below 100K. The trapped carrier was thermally activated with activation energies of 146.5meV for temperature range of 100-250K and 288.5meV for 250-450K. Finally, in the electric field strengths of 120-2000 Vcm-1, a high resistance phase appeared in the anionic solid at temperatures below 100K. The current was a quadratic function of the d.c. bias voltage, and the carrier mobility was independent of the field strength [ABSTRACT FROM AUTHOR]

In this thesis, the intensity of the local electric field in the cathode region of a hollow cathode discharge operated in hydrogen was measured, in a wide range of pressures and currents to study the influence of the diameter (10 and 15 mm) and material of the cathode used (stainless steel and tungsten). The method is based on the Stark effect of the level n=2, via the absorption of two 243 nm photons, circularly polarized in opposite directions, to eliminate the Doppler effect. When the atom is in the 2S state, it photo-ionizes, modifying the impedance of the plasma, which can be detected as the voltage drop on a resistor (optogalvanic spectroscopy). The local electric field is determined by comparing the separation of the Stark components with the theoretical values. [ABSTRACT FROM AUTHOR]

The objective of this paper is to propose a method for quantitatively estimating the breakdown voltage of double short vacuum gaps in series under the lightning impulse voltage. The study found a quantitative relationship between the breakdown voltage and the maximum electric field strength at the cathode. This relationship is validated by previous experimental works when the total gap distance is less than 20 mm. [ABSTRACT FROM AUTHOR]

At present, the method of obtaining the voltage of transmission lines by using the inverse problem of the electric field is generally faced with the difficulties of solving data equations. Aiming at the above problems, the method that solves transmission wire voltage through spatial electric field integration based on D-dot sensor is proposed. In this paper, with the ground as the reference potential and the vertical line of the transmission line to the ground as the integral path, D-dot electric field sensor is applied to measure the instant electric field values of several nodes on the integral path and the transmission wire voltage is directly solved combined with Gauss–Legendre numerical integration algorithm. The Gauss–Legendre algorithm is verified by the electric field distribution data on the integration path obtained by simulation. Furthermore, the improvement of the Gauss–Legendre algorithm is realized through optimizing the integral interval so that the location of integral nodes is more reasonable. Finally, the measurement system based on LabVIEW is designed and the experiment platform of the analog transmission line is constructed. Experiment results show that the measurement method of transmission wire voltage through the improved Gauss–Legendre algorithm based on D-dot sensor owns high accuracy with an error of less than 1%. [ABSTRACT FROM AUTHOR]

In search of an optimal gene electrotransfer (GET) protocol, an electroporation-based (EP) tumor treatment with great potential as a non-viral gene-delivery system, the concept of the dose-response relationship is introduced. It is shown that a reliable dose parameter is the pulse dosage and reliable response parameters are the reversibly electroporated tissue area as well as the unwanted damaged tissue area and plasmid damage due to pH. The standard stationary EP model consists in computing the reversibly electroporated tissue area in the first pulse as the region of tissue subjected to an electric field distribution higher than an electric field threshold for EP, where the electric field threshold comes from an experimental measurement and the electric field distribution from the solution of the nonlinear stationary Laplace equation for the electrostatic potential. The extended standard EP model introduced here consists in replicating for n consecutive pulses the standard EP model, via the experimental measurement in time of the successive thresholds. Because experimental data of this threshold variation is lacking, an exponential time decay function is assumed based on experimental measurements. The damage induced by pH fronts is defined as the tissue area subjected to pH abrupt changes above a basic threshold or below an acid threshold, where these changes come from numerical solutions via the electrolytic ablation (EA) model for EP-based protocols and the basic and acid thresholds from experiments. An optimal dose-response relationship in a GET protocol, for the range of pulse intensities with fixed pulse length and frequency, tested here, is predicted as the critical pulse dosage yielding maximum reversibly electroporated tissue area with minimal tissue area damage induced by pH fronts. Moreover, since damage induced by pH changes is proportional to the Coulomb dosage, damage induced by pH fronts is negligible in typical EP-based tumor protocols such as in electrochemotherapy (ECT) and irreversible electroporation (IRE) but not in GET, due to the most often longer pulses applied/used, i.e. higher dosage applied. Image 1 • Pulse dosage is a reliable dose parameter in a GET protocol. • Reversibly electroporated tissue, and damaged tissue induced by pH fronts are reliable response parameters in a GET protocol. • Optimal dose-response in GET protocols is the critical pulse dose yielding maximum electroporated tissue with minimum damage. • pH damage is negligible in ECT and IRE, but not in GET, due to the most often higher dosage applied. [ABSTRACT FROM AUTHOR]

To study corona discharge in air, it is important to measure the electric field in the discharge space, which is directly related to the corona discharge process. In this paper, we present a method for measuring the electric field with electro-optical modulation. This method uses space laser modulation based on Bi4Ge3O12 (BGO) crystals, and we suggest using the dual optical path difference method to improve the measurement performance. The measurement error is analyzed from theory, including the measurement error of a highly inhomogeneous electric field and the error due to theoretical approximation. In system calibration, the system noise and the dual optical path difference method were analyzed. The dynamic linear range is determined, and measurement effectiveness in the severely nonuniform electric field is verified by comparison with a finite element numerical simulation. We measured the electric field in Trichel pulses under negative dc voltage and found electric field pulses. These measurement results show that the characteristics of Trichel pulses are directly related to the electric field. Therefore, this method can provide strong support for the study of corona discharges. [ABSTRACT FROM AUTHOR]

Both Standards EN 50522 and IEEE 81 propose the fall of potential method (FPM) to carry out the measurement of the resistance to earth ($R_{\text{ES}}$) of an earthing system (ES). However, in urban areas, the recommended distances between the ES and auxiliary electrodes are not easy to respect, due to the presence of buildings and tarmac. Furthermore, unknown buried metallic parts and interconnections among ESs could modify the earth potential profile of the area, affecting the measurement results. In this paper, the key-issues that influence the measured $R_{\text{ES}}$ when the FPM is used in an urban environment are presented. A parametric analysis, carried out with Comsol Multiphysics, quantifies the errors due to wrong positioning of the auxiliary electrodes and due to the presence of interconnected ESs in the proximity of the ES under test. In addition, a real case of field measurement is described, emphasizing the main aspects that could compromise the results. Finally, practical suggestions to reduce errors are provided. [ABSTRACT FROM AUTHOR]

A three-dimensional (3D) finite-element analysis model is established based on the structural characteristics of ±1100 kV oblique-dry-type smoothing reactor, to optimisation of the external insulation configuration thereof by the Comsol Multiphysics. The electric field on the grading ring and insulators surface is calculated and analysed. The results show that the electric field is extremely uneven and the electric field strength of the outer layer of the rain cover and the grading ring connected with the lowest layer of the main body is the largest around the whole model. Accordingly, it is proposed to enlarge the diameter of the outer layer of the grading ring, reduce the layer numbers of grading ring on the rain cover, and reduce the smoothing layer numbers of grading ring outside the insulation pillar: this should make the electric field distribution of the reactor surface more uniform. The experimental platform was established in Beijing Changping ultra-high voltage test base and causalcomparative tests of setup were undertaken to compare the external insulation characteristics of the smoothing reactor optimised with the original. The experimental results demonstrate that the switching impulse voltage of the smoothing reactor increases and the external insulation performance of the smoothing reactor are thus improved. [ABSTRACT FROM AUTHOR]

Active flow control with electrohydrodynamics (EHD) force in the channel flow has been numerically investigated for enhancing heat transfer. This study focuses on the effect of electrode bank arrangements and the number of electrodes on corona wind and fluid flow for heat transfer onto a porous medium. Aligned and staggered configurations of electrode banks are compared. The numerical results show that electric field intensity depends on electrical voltage and the number of electrodes. Shear flow is increased with larger numbers of electrodes and in the aligned configuration, resulting in the enhancement of vortex strength. The swirling flow from staggered configurations spread wider than that of aligned configurations, but the aligned configuration produced more turbulence. In addition, the temperature distribution in the channel flow is increased with increasing numbers of electrodes. With the effect of swirling flow, airflow above the porous sample surface is faster leads the heat to more transfer to the porous sample surface. This causes the temperature of porous medium to increase rapidly so the convective heat transfer coefficient on porous medium surface is increased. Finally, the modified case of the numerical results is validated against the experimental results. The experimental flow visualization is based on the incense smoke technique, in order to verify the accuracy of the swirling flow pattern subjected to the electric field. It is shown that the comparison results in both techniques are in good agreement. [ABSTRACT FROM AUTHOR]

This paper deals with Potential Induced Degradation (PID) of p -type monocrystalline PV modules (Evergreen) from a photovoltaic power plant that has been in operation mode for 7 years. Within the PV module affected by the PID degradation, the effect of the electric field on individual PV cells is studied. The distribution of the electric field was simulated by SolidWorks software. The results show a random distribution of affected PV cells not related to the size and distribution of the electric field intensity. Furthermore, the dependencies of negative voltage potential on the range of PID degradation of individual PV modules located in the negative pole of the PV string is made. From measured current voltage characteristics (measured at STC), it is evident that the value of negative voltage potential is not directly proportional to the PID occurrence. These results are supplemented by electroluminescence images which confirm this finding. [ABSTRACT FROM AUTHOR]

A theoretical method for the determination of an electric field near a paraboloidal metal (conducting) tip has been proposed. The accuracy of the proposed numerical solution has been analyzed. The dependence of the electric field strength at the tip vertex on the distance to the plane, which is applicable for predicting fields in various physical problems and engineering calculations, has been considered. The characteristic spatial distributions of the electric potential and field are presented. [ABSTRACT FROM AUTHOR]

Overhead line energization can be performed under normal or faulty conditions. The latter indicates an occurrence of a fault along the line that exists at the moment of energization. This can lead to significant over-voltages that could endanger proper line operation. The issue gets more complex to protective devices when it comes to high-resistance faults, which impair the ability of relays to react promptly and accurately. Consequently, installation of additional detection devices becomes necessary. This paper proposes a novel method that properly detects and classifies line operating conditions at the moment of energization. The method is designed to be useful for utilities and it can be considered as a low-cost, fast, and accurate detection and classification approach, suitable for dealing with both low-resistance and high-resistance faults. Through comprehensive mathematical modeling it was found that both normal and faulty conditions during line energization are accompanied by the zero-sequence voltages of specific characteristics. The differences between zero voltage sequences are reflected in harmonic content, magnitudes of dominant frequencies, and their phase angles in regard to supply voltage. These findings are taken as the method's detection and classification criteria. The validity of the proposed model is verified by simulations and by field measurements. [ABSTRACT FROM AUTHOR]

In urban and industrial areas, a relevant presence of buried metallic objects (e.g., gas and water pipes, etc.) can be detected. Usually, these elements are imagined as widespread meshed metallic grids in a good contact with the soil. In the last years, an arising interest on their role in the identification of a global earthing system has been expressed by the scientific community. Unfortunately, the geometrical and electrical properties of this kind of buried metallic parts cannot be provided by any documentations. This is mostly due to the fact that no trustworthy schemes are provided, as the management of these metallic parts is responsibility of different companies, which have installed them during several years. In order to characterize the buried metallic elements with reference to the electrical safety issue, the main quantity of interest is their resistance to earth. With this aim, a field measurement campaign was organized and the resistance to earth of more than 800 metallic objects has been evaluated through a simplified measurement protocol. In this paper, the measurement protocol, the setup, the results, and their analysis are reported. [ABSTRACT FROM PUBLISHER]

The electrical properties of cobalt-rich crusts are selected as the research object, which are necessary to study breaking cobalt-rich crusts by high voltage. A special testing platform is designed for testing this mineral to determine dielectric constant, breaking voltage and breaking electric field strength. Different specimens of cobalt-rich crusts and substrate rocks are tested on this platform. The experimental results are calculated and analysed, and the conclusions are as follows: Under different frequencies of inputting voltage, the relative dielectric constant of cobalt-rich crust is not a constant, usually the lower frequency and the larger dielectric constant. When the voltage frequency is 1 or 4 MHz, the values of dielectric constant of dry and wet specimens are close, and when the voltage frequency is within 1–100 kHz, the values of dielectric constant of dry and wet specimens have huge differences. From the calculated results, the breaking and fluctuating electric field strength of cobalt-rich crusts is much smaller than that of substrate rocks, which is the theoretical basis for breaking deep-sea cobalt-rich crusts by high voltage. [ABSTRACT FROM PUBLISHER]

Fouled anion exchange resins were regenerated by electric field intensification of Mg/Al doublemetal hydroxides. Regenerative experiments were performed with varying voltages (10-30 V) and dosages of Mg/Al hydroxides (0.045-0.135 mol and 0.015-0.045 mol, respectively) for 1-5 h. Optimal results were obtained under the following regenerative conditions: 20 V, 4 h, and 0.09/0.03 mol of Mg/Al hydroxides. The maximum regenerative capacity of resins was increased to 41.07%. The regenerative mechanism was presented by Fourier-transform infrared spectrum of resins and Mg/Al hydroxides, and the regenerative degree was analyzed with respect to conductivity, pH value, and electric current. Mg/Al hydroxides were also recycled after the regeneration. This method was proven to be cost-effective and environmentally friendly. [ABSTRACT FROM AUTHOR]

This paper proposes a fast and accurate method for determining the electric potential and the radial and axial components of electric field intensity produced by a finite cylindrical surface charge distribution. The surface charge density has been modeled having a linear variation along the axial dimension of the cylinder. This consideration is very important when large bodies are to be modeled by means of an arrangement of elements (such as finite cylinders, disks, cones, etc.) allowing the matching between them and also avoiding discontinuities on charge distribution. The mathematical expressions presented in this paper have shown high computational performance while ensuring accurate and reliable results. [ABSTRACT FROM AUTHOR]

An on-line monitoring system based on a two-stage voltage divider is presented for monitoring the switching and lightning over-voltages in 10–35-kV medium-voltage grids. A low-damped capacitive divider (voltage ratio of 1000:1) is designed as an over-voltage monitoring sensor for primary voltage division, and an R-C damped divider is designed for the secondary voltage division (voltage ratio of 10:1 for the 10-kV grid and 20:1 for the 35-kV grid). The divider's designing methods and response characteristics are analyzed. The result of the measurement indicates that the voltage divider has good frequency response, which can meet the requirements for monitoring switching and lightning over-voltages. Moreover, with the data double-buffering and high-speed sampling techniques, this device can collect longer data (64 Mbytes) and shorten the interval (less than 1 sec) at a high sampling rate (up to 20 MHz). Finally, the device has been installed in a 110-kV substation in parallel with a 10-kV bus for two years. Many over-voltage waveforms (including switching, induced lightning, and back-flashover lightning over-voltages) are captured on site. The actual measured results indicate that the device can monitor fast transient over-voltages precisely. [ABSTRACT FROM AUTHOR]

An analytical study of the plasma states in non-neutral plasma diodes in the presence of an external transverse magnetic field is presented for an arbitrary neutralization parameter γ. Considerations are restricted to the regime where no electrons are turned around by the magnetic field. The emitter electric field strength E0 is used as a characteristic function to investigate the existence of solutions depending on the diode length, the applied voltage, the neutralization parameter, and the magnetic field strength. The potential distribution has a wave form for small magnitudes of the external magnetic field, as well as for the case when magnetic field is absent. A new family of solutions appears along with the Bursian ones. On the other hand, as the Larmor radius becomes comparable with the beam Debye length, oscillations in the potential disappear, and only the Bursian branches remain. Unlike the vacuum diode, there are steady state solutions for the negative values of the emitter field strength. As the neutralization parameter (γ) increases, the emitter field strength relating to the SCL (space charge limit) bifurcation point diminishes, and at γ>1, the value of the emitter's electric field strength at the space charge limit (E0,SCL) turns out to be negative. [ABSTRACT FROM AUTHOR]

According to the operating specifications of existing electric field measuring instruments, measuring technicians must be located far from the instruments to eliminate the influence of the human body occupancy on a spatial electric field. Nevertheless, in order to develop a portable safety protection instrument with an effective electric field warning function for working staff in a high-voltage environment, it is necessary to study the influence of an approaching human body on the measurement of an electric field and to correct the measurement results. A single-shaft electric field measuring instrument called the Type LP-2000, which was developed by our research team, is used as the research object in this study. First, we explain the principle of electric field measurement and describe the capacitance effect produced by the human body. Through a theoretical analysis, we show that the measured electric field value decreases as a human body approaches. Their relationship is linearly proportional. Then, the ratio is identified as a correction coefficient to correct for the influence of human body proximity. The conclusion drawn from the theoretical analysis is proved via simulation. The correction coefficient kb = 1.8010 is obtained on the basis of the linear fitting of simulated data. Finally, a physical experiment is performed. When no human is present, we compare the results from the Type LP-2000 measured with Narda EFA-300 and the simulated value to verify the accuracy of the Type LP-2000. For the case of an approaching human body, the correction coefficient kb* = 1.9094 is obtained by comparing the data measured with the Type LP-2000 to the simulated value. The correction coefficient obtained from the experiment (i.e., kb*) is highly consistent with that obtained from the simulation (i.e., kb). Two experimental programs are set; under these programs, the excitation voltages and distance measuring points are regulated to produce different electric field intensities. Using kb = 1.9094, the corrected measurement of electric field intensity can accurately reflect the original environmental electric field intensity, and the maximal error is less than 6% in all the data comparisons. These results verify the effectiveness of our proposed method. [ABSTRACT FROM AUTHOR]

The payload of the four Cluster spacecraft dedicated to multipoint measurements in the earth’s magnetosphere includes ion emitters that can emit currents up to a few tens of microamperes to partially compensate for the photoemission current originating at the spacecraft surfaces and thereby achieve a reduction in the spacecraft potential from values often as high as several tens of volts positive to values well below 10 V. This effect is highly desirable to improve on-board particle measurements, especially of electrons, by reducing the photoelectron flux into the sensors and by reducing the distortions of particle trajectories in the spacecraft sheath. On the other hand, a perfectly stable spacecraft potential precludes the utilization of the spacecraft as a plasma probe, including the useful technique to estimate ambient plasma density from the spacecraft potential. This paper shows that the small residual variations of the potential still allow the determination of ambient plasma density, albeit at reduced accuracy. We present an outline of the applied method with examples. In spring 2002, in the cusp region, the Cluster interspacecraft distances were well below 1000 km. For selected intervals, the potentials of controlled and uncontrolled spacecraft are compared, taking advantage of the fact that the ion emitters were not operating on all spacecraft. Special considerations regarding the secondary electron production and its effect on the controlled spacecraft potential were found to be necessary, and examples of this aspect are presented as well. Finally, the effect of the potential control on the double-probe electric field measurements is assessed. It is found that the normal sun-aligned offset of the electric field caused by the asymmetric spatial distribution of photoelectrons around the spacecraft can be affected by the potential control. Nonetheless, the information about plasma density is not lost when active spacecraft potential control (ASPOC) is applied. This is also relevant for future missions with ASPOC, particularly the NASA Magnetospheric Multiscale mission launched in March 2015. Regular intercalibration of controlled and uncontrolled potentials is nonetheless advisable to increase the reliability of the method. [ABSTRACT FROM PUBLISHER]

Ionic micelles have been simulated in an aqueous solution of single-charged counterions using the molecular dynamics method. It has been demonstrated that the contribution of water molecules needs to be explicitly taken into account when computing the electrical field strength of a micelle. This contribution results in a complex local dependence of the electric charge and gives rise to a charge reversal region in the immediate vicinity of the micelle crown, thereby causing a nonmonotonic behavior of the electric potential. The computations have been performed for both cationic and anionic micelles. A model micelle consists of a rigid hydrocarbon core (impenetreable to water molecules and counterions) and cationic fragments of a surfactant. Data obtained for three molecular models of water (SPC, TIP5P, and two-centered S2 models) have been compared with the results of the continual description of the solvent. For all water models, its local contribution to the electric field around micelles is significant even at large distances from the particle surface. [ABSTRACT FROM AUTHOR]

An accurate model of nonlinear load is important for the evaluation of power quality (PQ). Among different PQ disturbance sources, alternating current electric arc furnace (AC EAF) is one of most complicated and serious loads. To provide effective operation prediction of AC EAF, a data-driven modeling approach based on time- and frequency-domain voltage-current (v -i) characterization is proposed in this paper. With the prediction of the proposed model in the time domain, the dynamic and short-term behavior of AC EAF can be observed. And the quasistationary and long-term features of AC EAF would be extracted via the frequency-domain phase of the proposed model. From the comparison on the field measurement data, the performance of the proposed model can be verified in the applications of PQ studies. [ABSTRACT FROM AUTHOR]

A method of predicting the residual breakdown electrical field strength of an epoxy-mica paper insulation system is described. This method was developed by using data on service?aged stator bars from generators as well as accelerated aging model bars. Thermal aging, mechanical aging, and combined thermal and mechanical aging were done individually as accelerated aging. The partial discharge characteristics, dissipation factor, and breakdown voltage were measured on the model bars and service?aged bars from generators. From these results, the residual breakdown electrical field strength was predicted based on the partial discharge characteristics and dissipation factor. First, the dominant type of deterioration (thermal or mechanical aging) on a bar?s insulation was determined by the pattern of voltage?partial discharge magnitude characteristics. Then the residual breakdown electrical field strength was predicted by using a predicting equation for both thermal and mechanical aging. Each predicting equation uses dissipation factor tip-up (i.e. difference in dissipation factor values between 2 kV and rated voltage) and partial discharge inception electrical field strength. The accuracy of this method was confirmed using data measured on 112 service-aged stator bars from generators and 10 accelerated aged model bars. The 95% confidence interval level included 94% of the measured residual breakdown electrical field strength values. This result shows that the method enables precise predictions of the residual breakdown electrical field strength of an epoxy-mica paper insulation system. [ABSTRACT FROM AUTHOR]

A methodology for extracting the lateral electric field ( \boldsymbol E\boldsymbol {x} ) in the drain extension of thin silicon-on-insulator high-voltage field-plate assisted reduced surface field (RESURF) devices is detailed including its limits and its accuracy. Analytical calculations and technology computer-aided design device modeling corresponding to experimental data are used. It is shown how to obtain trapped interface charge distributions (e.g., due to hot-carrier injection) from the extracted fields. Thus, a new method for determining the position and quantity of injected charges in the drain extension of RESURF power transistors is introduced. [ABSTRACT FROM AUTHOR]

Based on the similarity theory, a reduced-scale model is proposed to study the voltage distribution characteristics in ultrahighvoltage direct current converter transformer windings under the impulse voltage. Through comparing the distribution characteristics of electric field intensity and magnetic flux intensity of the scale model with that of the original model, the effectiveness of the reduced-scale method is verified. Furthermore, the actual production design is also considered in the model. The matrices of the inductance, capacitance, and resistance parameters for the reduced-scale model are obtained by finite element method. Then, the multi-conductor transmission line model is set up to study the propagation process of impulse voltage along the windings of the converter transformer. The voltage distribution curve is obtained under a standard lighting impulse voltage and the turn-to-turn fault is taken into consideration as well. The simulation results are the basis for the following experimental study. [ABSTRACT FROM AUTHOR]

A pole mounted 'field mill' type electrostatic fieldmeter provides a simple and practical way for measurement, and for long term continuous monitoring, of ground level atmospheric electric fields. The paper describes a number of studies of this measurement method. These show how atmospheric electric field values are derived from the response of the fieldmeter when earth bonded and its height above ground level. The response of the fieldmeter is calibrated via the linear variation of its response to voltage applied during the set up procedure. The studies confirm a linearity of fieldmeter response with height above ground. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present a numerical algorithm for investigating the dynamic characteristics of a simple model of the dielectric barrier discharge in air. The proposed algorithm is based on the finite element method and is capable of determining the distribution of electric field intensity and space charge density in the point-plane geometry, when the plane is covered with a thin dielectric layer and the needle is energized with a sinusoidal voltage. The simulation results show the behavior of corona current and space charge density for a few values of the input voltage and frequency. The aim of this parametric study is to investigate the effect of voltage, and frequency on the time variation of the discharge. [ABSTRACT FROM AUTHOR]

In this study, electric field effect was investigated by dry band arcing test method. ADSS (all-dielectric selfsupporting) cables are usually placed on power grids. These cables are affected by temperature and are exposed to many environmental effects such as wind and UV rays. In this study, the effect of water flow over ADSS cable on electric surface erosion on dry surfaces was investigated by electric arcing method, according to IEEE 1222 standard and the electric field intensity at the surface and the electric potential distribution were analyzed using the finite element method. [ABSTRACT FROM AUTHOR]

The acceptability of pulsed electric field (PEF) processing as an alternative method for liquid food preservation requires the elimination, or at least the reduction, of all the effects accompanying the flow of electric current. Metallic particles might be released from the electrode material as a result of electrically driven electrochemical reactions. The presence of such metallic particles can affect the quality and the safety of PEF-processed food. This paper investigates the effect of varying the parameters of applied electric pulses on the amount of released metals, aiming to reach the optimum conditions. It is expected that reducing the rate of releasing metals from the electrodes will extend their lifetime and reduce the running cost of the PEF process. [ABSTRACT FROM PUBLISHER]

We report experimental observations of the controlled deformation of a dielectric liquid jet subjected to a local high-voltage electrostatic field in the direction normal to the jet. The jet deforms to the shape of an elliptic cylinder upon application of a normal electrostatic field. As the applied electric field strength is increased, the elliptic cylindrical jet deforms permanently into a flat sheet, and eventually breaksup into droplets. We interpret this observation--the stretch of the jet is in the normal direction to the applied electric field--qualitatively using the Taylor-Melcher leaky dielectric theory, and develop a simple scaling model that predicts the critical electric field strength for the jet-to-sheet transition. Our model shows a good agreement with experimental results, and has a form that is consistent with the classical drop deformation criterion in the Taylor-Melcher theory. Finally, we statistically analyze the resultant droplets from sheet breakup, and find that increasing the applied electric field strength improves droplet uniformity and reduces droplet size. [ABSTRACT FROM AUTHOR]

Highlights: [•] New method for charge mobility measurement in organic semiconductor thin films. [•] Measuring mobility as function of electric field and charge carrier density μ(F, n). [•] Direct measurement – no fitting to a mobility model required. [•] Based on space-charge limited current in single carrier devices of varying thickness. [•] Applicable to neat and blend layers. [Copyright &y& Elsevier]

Abstract: A calculation has been performed for the interaction force and the field strength in a system consisting of two charged conducting balls in three cases: 1) the balls are maintained at the preset potentials; 2) the balls are insulated and have fixed charges; 3) one of the balls has the preset potential, and the second one has the preset charge. Experimental measurements of forces in the first and third cases were performed and fair agreement with calculations was confirmed. A calculation method has been suggested, and the electric field strength on the nearest poles of the balls has been calculated for the three mentioned cases. A good agreement with the other authors' calculation results has been demonstrated. [Copyright &y& Elsevier]

A plasma actuator was operated at pressures from 760 to 88 torr to determine the mechanisms leading to decreased force production at low pressures. The actuator was driven with a 5 kHz sine wave and a peak to peak voltage of 13.4 kV. A passive measurement technique called the capacitive V-dot probe was adapted to the actuator to resolve the spatiotemporal evolution of the surface potential and electric field on the dielectric surface. At low pressures up to 20 times more plasma by visual inspection is present than at atmospheric conditions. Average force production is calculated and shown to decrease at lower pressures due to the fact that up to 88 % of the plasma is created in regions where the electric field is relatively weak. The calculated average body force shows a slight increase up to a pressure of 429 torr before trending to 0 at lower pressures in good qualitative agreement with experimental force measurements. Performing a power analysis shows that as pressure is decreased more power is used creating plasma rather than accelerating it, leading to a decrease in efficiency. [ABSTRACT FROM AUTHOR]

The response of field mill type electrostatic fieldmeters to alternating electric fields is limited by the chopping frequency. Measurements reported here show that alternating frequencies at the chopping frequency, and related harmonics, can create confusing low frequency outputs. Hence care is needed for interpreting observations where such alternating electric fields may be present. [ABSTRACT FROM AUTHOR]

The possibility of electrostatic charging of an electrically insulated metal body in plasma flow has been studied. Conditions for the appearance of a positive electric charge on the body surface are formulated in terms of plasma parameters and flow velocity. Estimates of the amount of charge, electric potential, and electric field strength of a metal sphere are obtained for an equilibrium state of charge/discharge currents. [ABSTRACT FROM AUTHOR]

This communication uncovers missing fundamental elements and an expanded model of gas phase electrodeposition; a relatively new and in large parts unexplored process, which combines particle generation, transport zone and deposition zone in an interacting setup. The process enables selected area deposition of charged nanoparticles that are dispersed and transported by a carrier gas at atmospheric pressure conditions. Two key parameters have been identified: carrier gas flow rate and spark discharge power. Both parameters affect electrical current carried by charged species, nanoparticle mass, particle size and film morphology. In combination, these values enable to provide an estimate of the gas flow dependent Debye length. Together with Langmuir probe measurements of electric potential and field distribution, the transport can be described and understood. First, the transport of the charged species is dominated by the carrier gas flow. In close proximity, the transport is electric field driven. The transition region is not fixed and correlates with the electric potential profile, which is strongly dependent on the deposition rate. Considering the film morphology, the power of the discharge turns out to be the most relevant parameter. Low spark power combined with low gas flow leads to dendritic film growth. In contrast, higher spark power combined with higher gas flow produces compact layers. This contribution describes an extended model of the gas phase electrodeposition. For the first time correlations between the transport gas flow, the spark discharge power, the nanoparticle flow, the nanoparticle mass and the film morphology are shown. The transport properties in the gas phase are strongly dependent on the transport gas flow, which represents the biggest difference in the description of the transport equation compared to classic electroplating. Image 1 • This article reports materials, methods and technology to increase the understanding of the in large parts unexplored gas phase electrodeposition process. • To understand the expanded model, two key parameters have been identified; the carrier gas flow rate and the spark discharge plasma power. • Both parameters affect measurable quantities such as the electrical current carried by the charged nanoparticles and gas ions, the nanoparticle mass, particle size and film morphology. • Particle generation rate, ratio between charged gas ions and charged nanoparticles are subsequently derived. • Together with Langmuir probe measurements of the electric potential and field distribution the transport can be described and understood. [ABSTRACT FROM AUTHOR]

Electrical dispersion of a water-in-oil emulsion under an electric field has an inhibitory effect on the eletrocoalescence. To clarify the mechanism of droplet breakup at the microscopic level, molecular dynamics simulation was performed to study the deformation and breakup characteristics of a moving droplet at different field strengths. The results showed that interparticle spacings increased with the growth of the field strength, leading to significantly higher values of the electrostatic potential and van der Waals potential, and hence an increase of the deformation degree. There was a substantial rise in the non-bonded potential energy with a sharp fall in the overall velocity of the droplet when the electric field was higher than 2.1 V nm−1, causing the development of droplet breakup. Through hydrogen bond and hydration analysis, it was found that the hydrogen bond lifetime and ion distribution were responsible for the formation of different breakup patterns. These results demonstrated that droplet break-up is highly dependent on weak intermolecular interactions such as strong attraction. • Weak interactions are used to explain droplet breakup mechanism. • Strong attraction has a significant impact on droplet breakup. • Three different droplet breakup modes are investigated. • Ion distribution and hydrogen bond lifetime can influence the breakup modes. [ABSTRACT FROM AUTHOR]

The economy of transporting large amount of power over long distance makes high voltage transmission line an important component of the power system. Outdoor insulators provide electrical insulation as well as mechanical support between energized conductor and grounded parts of the tower. Its performance is closely related to the reliability of power delivery. Various parameters affect the insulator flashover performance, but the measurement and analysis of all those parameters would be a challenging and complex task during online inspection. The performance of the insulators is directly dependent on the electric field distribution inside and surrounding them. The aim of this work is to obtain the relationship between flashover voltage and electric field distribution. Accordingly, a novel electric field measurement technology, which was recently commercially available, was utilized in this paper to measure the electric field distribution around six different varieties of composite and ceramic insulators. The relationship between conductivity of the contamination layer and the environmental relative humidity was initially evaluated. Further, the patterns of the electric field distribution for clean, uniform and non-uniform contamination cases were studied and its relationship with the flashover voltages was explored. Electric field calculation with commercially available package was performed to validate the experimental results and extend the conclusion to higher voltage levels. [ABSTRACT FROM AUTHOR]

• Study on the electromagnetic field onboard to evaluate EMI in critical points. • The onboard acquisition systems are potentially affect by electromagnetic noise. • A preliminary electromagnetic screening is advisable to optimize the ship cabling. When performing oceanography measurements, it is critical to assess the presence of the noise sources that could affect the measured data and lead to wrong interpretation of the results. This paper report the result of an oceanography survey conducted by ISMAR-CNR, Naples, in the north-eastern marine sector of the Ischia Island and assess the influence of EMI on the measured results. The analyzed measurements of the Electric and Magnetic fields showed values of the E up to 0.82 V/m and of B up to 85 μT. By assuming a standard conductor, an inductance L up to 47 Ω on the cable corresponding to an induced electromotive force of 1184 mV was calculated. Also the experimental data show the EMI increase in site where the Pearson index correlation is higher. The results demonstrate that in an oceanographic survey planning, a preliminary electromagnetic screening is advisable to optimize the measurement setup. [ABSTRACT FROM AUTHOR]

Plasma redistribution in a symmetric microchannel-cavity hybrid structure device has been investigated by modulating the applied electric field strength. The device array has been operated in 200 Torr of argon, driven by a 20 kHz bipolar waveform. With the existence of the intervening microchannel between microcavities, several stable modes of operation of the microplasma have been observed, including cavity mode, hybrid mode and channel mode. Transition between the modes occurs with modulation of the applied voltage from 800 to 1100 V. The characteristics of microplasma propagation in different modes are investigated and the propagation speed along diagonal direction of the device in cavity mode, hybrid and channel mode are calculated to be ~48, ~29 and ~32 km s−1, respectively. Nonhomogeneous electric field strength distribution and plasma interaction have been discussed to explain these experimental results. Emission intensity and propagation speed differences in the cavity mode between the polarities of the applied voltage are interpreted through spatially resolved measurements of the emission profile in a partial channel-cavity array. [ABSTRACT FROM AUTHOR]

We quantitatively separate interface optical second harmonic generation (SHG) and electric-field induced second harmonic generation (EFISH) from hydrogenated amorphous silicon (a-Si:H) interfaces and bulk. Using a 1.51 eV probe laser, we measure SHG signals from indium tin oxide (ITO) ITO/a-Si:H/ITO sandwich structures and vary the electric fields in the a-Si:H layer using an applied voltage bias. The a-Si:H/ITO interfaces form back-to-back diodes. Because of finite optical penetration depth, SHG probes only the front diode. When the front diode is reverse biased, the EFISH contribution dominates the SHG signal and probes the electric field in the ∼30 nm adjacent to the interface. Through fitting of the SHG data, we find that in this near-interface region, the electric field is proportional to the square root of the applied bias. The fitting measures the interfacial ITO/a-Si:H built-in voltage to be ∼0.2 V. [ABSTRACT FROM AUTHOR]