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During thermal annealing at 1425 °C nominal electric field strengths of 50 V/mm and 150 V/mm were applied along the grain boundary planes of a near 45° (100) twist grain boundary in SrTiO$_3$. Electron microscopy characterization revealed interface expansions near the positive electrode around 0.8 nm for either field strength. While the interface width decreased to roughly 0.4 nm after annealing at 50 V/mm, the higher field strength caused decomposition of the boundary structure close to the negative electrode. Electron energy-loss and X-ray photoelectron spectroscopies demonstrated an increased degree of oxygen sublattice distortion at the negative electrode side, and enhanced concentrations of Ti$^{3+}$ and Ti$^{2+}$ compared to bulk for both single crystals and bicrystals annealed with an external electric field, respectively. Oxygen migration due to the applied electric field causes the observed alteration of grain boundary structures. At sufficiently high field strength the agglomeration of anion vacancies may lead to the decomposition of the grain boundary.

A Position Calibration Method (PCM) is proposed for a single cell measurement with Electrochemical Impedance Spectroscopy (EIS). It improves the measurement accuracy by reducing the error induced by position difference. First, the relationship between the impedance and the position is explored with numerical simulation. The impedance is calculated in different positions of the single cell with the finite model. Second, a mathematical model is established based on the relationship between the impedance and the position. Then, the experiments are conducted to verify the valid of the PCM. In the experiments, Na2O∙CaO∙6SiO particles and Zebrafish eggs are used. The result shows that the impedance near the electrode is less than the center of the sensor, while the impedance of the sensor center is less than the sensor boundary, which is the same as the numerical simulation. Finally, a coincidence degree is employed to evaluate the position calibration method. After position calibration, the coincidence degree of numeric simulation could reach to 99.999%, and the experimental coincidence degree reaches to 99.87%. In this paper, the reasons of impedance varying with positions are also explored. The electric field intensity turns out to be the main internal factor that causes the impedance varying with positions. Furthermore, the PCM is expected to realize the detection of a cell structure.

Pulsed electric field disinfection is an effective non-thermal water disinfection technology. Compared to conventional disinfection techniques, PEF inactivation has several advantages including no by-products. In this context, the use of silver ions in conjunction with a reverse osmosis filtration system has been proposed as a safe and cost-effective treatment approach that can be used in a point of use technologies. This system contains two silver meshes as electrodes inside a reverse osmosis membrane with the application of a pulsed electric field on it as a disinfection method, After conducting chemical and physical tests of the water samples before and after the treatment system, it was noticed that most of these characteristics were significantly affected by increasing the number of electrical impulses and the intensity of the applied voltage as a result of the increase in the ionization process of silver in water.

An algorithm for solving exciton Schrodinger equation in an arbitrary 2D multiple quantum well structure under applied electric field is proposed, allowing one to model both the absorption and refraction spectra consistently and efficiently. It gives much better quantitative results than variational approximation, while being faster than more advanced methods. The algorithm is implemented using R language and tested by comparing to other published results. Possible improvements are discussed.

One of the major challenges of the food industry is to develop more sustainable processing technologies. To address this change, it is necessary to have more information about available innovative technologies and their effect on different food matrices and processes to ensure efficiency in food chain management. The aim of this research was to increase the understanding of the physical modifications induced by the combination of pulsed electric field (PEF) pre-treatment and further drying in carrot and potato tissues by modelling the sorption isotherms and the textural properties. High coefficient of determination up to 0.980 for GAB and 0.977 for BET were obtained confirming the good ability of both models to describe the sorption isotherm of foodstuff. Either BET and GAB classified carrot in a III type shape and potato in II type shape for sorption isotherm. Mechanical properties for carrot and potato considering all PEF treatment and aw levels were reported and fitted by modified Fermi distribution. High coefficient of determination up to 0.995 confirm the ability of Fermi model to describe mechanical properties in relation to water activity (aw).

The electromagnetic radiation produced by cellular towers in Ramadi city, west of Iraq, is measured and analyzed in this research. This contains basic nodes, hub repeaters, and feeders for transmitting the carrier throughout the entire Ramadi city as well as the surrounding areas. As a result, this research focused on this area to measure and assess energy to determine if it is safe for people or has over the danger threshold. The study region was split into fifty-five mobile phone tower locations. In general, electric field intensity levels surpass 1.7 V/m, which is dangerous and should be reduced. However, apart from a few sites (2, 3, 35, 36, 45, 51, and 53), the magnetic field intensity and radiation density are acceptable based on the findings. The energy severity criteria are based on LATNEX corporation's guidelines.

Background and ObjectiveTranscranial direct current stimulation (tDCS) has wide ranging applications in neuro-behavioural and physiological research, and in neurological rehabilitation. However, it is currently limited by substantial inter-subject variability in responses, which may be explained, at least in part, by anatomical differences that lead to variability in the electric field (E-field) induced in the cortex. Here, we tested whether the variability in the E-field in the stimulated cortex during tDCS, estimated using computational simulations, explains the variability in tDCS induced changes in GABA, a neurophysiological marker of stimulation effect.MethodsData from five previously conducted MRS studies were combined. The anode was placed over the left primary motor cortex (M1, 3 studies, N = 24) or right temporal cortex (2 studies, N = 32), with the cathode over the contralateral supraorbital ridge. Single voxel spectroscopy was performed in a 2×2×2cm voxel under the anode in all cases. MRS data were acquired before and either during or after 1mA tDCS using either a sLASER sequence (7T) or a MEGA-PRESS sequence (3T). sLASER MRS data were analysed using LCModel, and MEGA-PRESS using FID-A and Gannet. E-fields were simulated in a finite element model of the head, based on individual MPRAGE images, using SimNIBS. Separate linear mixed effects models were run for each E-field variable (mean and 95th percentile; magnitude, and components normal and tangential to grey matter surface, within the MRS voxel). The model included effects of time (pre or post tDCS), E-field, grey matter volume in the MRS voxel, and a 3-way interaction between time, E-field and grey matter volume. Additionally, we ran a permutation analysis using PALM to determine whether E-field anywhere in the brain, not just in the MRS voxel, correlated with GABA change.ResultsIn M1, higher mean E-field magnitude was associated with greater tDCS-induced decreases in GABA (t(24) = 3.24, p = 0.003). Further, the association between mean E-field magnitude and GABA change was moderated by the grey matter volume in the MRS voxel (t(24) = −3.55, p =0.002). These relationships were consistent across all E-field variables except the mean of the normal component. No significant relationship was found between tDCS-induced GABA decrease and E-field in the temporal voxel. No significant clusters were found in the whole brain analysis.ConclusionsOur data suggest that the electric field induced by tDCS within the brain is variable, and is significantly related to tDCS-induced decrease in GABA, a key neurophysiological marker of stimulation. These findings strongly support individualised dosing of tDCS, at least in M1. Further studies examining E-fields in relation to other outcome measures, including behaviour, will help determine the optimal E-fields required for any desired effects.HighlightsWe study the link between individually simulated electric field dose and tDCS-induced change in GABA in the cortex.The electric field strength in the brain correlates with a decrease in GABA in the motor cortex.The correlation between the electric field and GABA change is modulated by the amount of grey matter in the MRS voxel.We find no association between the electric field and GABA in the temporal cortex.

First-principles calculations were performed on the evaporation field of Fe, Cu, Mn, and Si in Fe (001) and on the evaporation field and roll-up effect of Fe, Cu, and Mn in the Fe (001) step structure. The larger the evaporation barrier energy tendency, at an electric field of 0 V/nm (absorption energy), the larger was the evaporation field. Electric field evaporation calculation results indicate that the order in which the electric field is easily evaporated is Mn > Cu > Fe > Si. The tendency that Mn and Cu evaporate more easily than does Fe and that the evaporation of Si is less probable is consistent with the experiment of a dilute element in steel. In the Fe (001) step structure, when the electric field is low, the roll-up effect where the evaporated atoms move on the step is large, and when the electric field is large, the roll-up effect is small. The roll-up effect of Cu was almost the same as that of Fe, and the roll-up effect of Mn was small because the chemical bond between Mn and Fe was weak.

As a three-dimensional characterization method, atom probe tomography can provide key information that other methods cannot offer. Conductive coatings have proved to be an effective way for biological samples, and nonconductive samples in general, to be analyzed using voltage-pulsed atom probe tomography. In this study, we analyzed the effects of graphene coating on an electrically conductive material and were able to confirm the detection of carbon atoms. We compare quantitative electrostatic field metrics for a single-coated and a multi-coated specimen and measure both a reduced voltage after graphene coating and lowered charge-state ratios for different ion species, suggesting a lowered evaporation field related to the graphene coating. This information will be instructive for future studies on graphene-coated, nonconductive biological specimens.

Recently, fabricating type-II vertical van der Waals (vdWs) heterostructure is a promising material for hydrogen production. The absorption capability, charge density distributions, band alignments and electronic properties of the monolayers and heterostructures are systematically investigated using computational studies. Using ab initio molecular dynamics, binding energy and phonon calculations, the stability of the heterostructures are verified. Both heterostructures are type-II materials, which can increase the separation of charge carriers. Moreover, the charge density difference and the potential drop across the interface of MSe2/BSe creates a high built-in electric field that can prevent the recombination of charge carriers. We found that the visible-light optical properties of both heterostructures are much enhanced with suitable bandgap energy for water splitting. The band alignment suggests that the heterostructures straddle water redox potentials in acid solutions (0

Background: The re-emergence of infectious diseases and the increasing rate of the appearance of many antibiotic-resistant strains are major public health concerns. Zinc oxide nanoparticles (ZnO-NPs) have a great antibacterial effect. Few reports stated the antibacterial effect of low electric field (LEF). Objective: The paper aimed to study the antibacterial effect of LEF at low frequency and investigate the antibacterial effectiveness of using LEF in synergy with ZnO-NPs. Methods: Pseudomonas aeruginosa and Staphylococcus aureus were examined as models for Gramnegative and Gram-positive bacteria, respectively. The bacterial suspension was exposed to different concentrations of Zn-NPs ranging from 100-1600 μg/ml or 2 V/cm, 500 Hz AC electric field for 5 min. ZnO-NPs were prepared and characterized by UV-Vis spectroscopy, XRD, FTIR, TEM, and SEM. The combined effect of LEF exposure with each ZnO-NPs concentration was assessed. Results: 1600 μg/ml ZnO-NPs cause 41.93% and 48.15% death, LEF produces 20.88% and 28.03% death, and the synergetic effect causes 50.41% and 70.27% death for P. aeruginosa and S. aureus, respectively. The death percentages were correlated with DNA concentration and deformation, reactive oxygen species concentration, and ultrastructure changes. Conclusions: LEF has antibacterial properties and can be used in combination with ZnO-NPs to increase its lethal effect.

Purpose. The use of modeling as a tool that allows you to identify design weaknesses in electrical equipment and, on their basis, perform its optimization in order to level weaknesses due to design imperfections. Designation of a real problem in the design of polymer bushings, which negatively affects their technical, economic and operational characteristics and makes them less competitive compared to other types of insulators. Methodology. Analysis of experiments to detect partial discharges, simulation of electric field strength, synthesis of analyzed works and simulation results. Findings. As a result of the performed scientific research, it was found that the process of partial discharges has a direct effect on the electrical strength of the polymer bushing insulator. This fact is taken as the basis for searching for methods of further influence on the design of the insulator in order to increase its service life. It was found in the work that the reason for the occurrence of partial discharges is the uneven distribution of the electric field strength. This was the reason for further study of the electric field strength of the pass-through insulator and its modeling. As a result of the simulation, points of concentration of the electric field strength in the bushing polymer insulator were found and designated as points of action to increase the electrical strength of the bushing polymer insulator. Originality. The scientific novelty of the performed research work lies in the use of the simulation of the electric field of a polymer bushing as a tool for detecting weak points in its design, when exposed to which, a positive effect on its technical characteristics can be observed. Practical value. The practical value of the research work done is that the results of the research serve as a solid foundation for further optimization of the design of polymer bushings, which will lead to a positive impact on their technical characteristics and make them competitive compared to other types of insulators., Цель работы. Использование моделирования как инструмента, позволяющего выявлять слабые места конструкции в электрическом оборудовании и на их основе выполнить ее оптимизацию, с целью нивелирования слабостей из-за несовершенства конструкции. Обозначение реально существующей проблемы в конструкциях проходных полимерных изоляторов, что негативно влияет на их технико-экономическую и эксплуатационную характеристику и делает их менее конкурентными по сравнению с другими типами изоляторов. Методы исследования. . Анализ экспериментов по выявлению частичных разрядов, моделирование напряженности электрического поля, синтез анализируемых работ и результатов моделирования. Полученные результаты. В результате выполненного научного исследования было обнаружено, что непосредственное влияние на электрическую прочность проходного полимерного изолятора оказывает процесс возникновения частичных разрядов. Данный факт принят за основу для поиска методов дальнейшего воздействия на конструкцию изолятора с целью увеличения срока его службы. В работе обнаружено, что причиной возникновения частичных разрядов является неравномерность распределения напряженности электрического поля. Это послужило причиной для дальнейшего исследования напряженности электрического поля прохидного изолятора и его моделирования. В результате моделирования были обнаружены точки концентрации напряженности электрического поля в проходном полимерном изоляторе и обозначены их как точки воздействия для повышения электрической прочности проходного полимерного изолятора. Научная новизна. Научная новизна выполненной научно-исследовательской работы заключается в использовании моделирования электрического поля полимерного проходного изолятора как инструмента для обнаружения слабых мест в его конструкции, при воздействии на которые можно будет наблюдать положительное влияние на его технические характеристики.. Практическая ценность. Практическая ценность проделанной научно-исследовательской работы заключается в том, что результаты исследования служат прочным фундаментом для дальнейшей оптимизации конструкции проходных полимерных изоляторов, что приведет к положительному воздействию на их технические характеристики и сделает их конкурентными по сравнению с другими типами изоляторов., Мета роботи. Використання моделювання, як інструменту, що дозволить виявляти слабкі місця конструкції в електричному обладнанні та на їх основі виконати її оптимізацію, з метою нівелювання слабкостей через недосконалість конструкції. Позначення реально існуючої проблеми в конструкціях прохідних полімерних ізоляторів, що негативно впливають на їх техніко-економічних та експлуатаційних характеристика і робить їх менш конкурентними у порівнянні з іншими типами ізоляторів. Методи дослідження. Аналіз експериментів по виявленню часткових розрядів, моделювання напруженості електричного поля, синтез аналізованих робіт та результатів моделювання. Отримані результати. В результаті виконаного наукового дослідження було виявлено, що безпосередній вплив на електричну міцність прохідного полімерного ізолятору має процес виникнення часткових розрядів. Даний факт прийнято за основу для пошуку методів подальшого впливу на конструкцію ізолятора, з метою збільшення строку його служби. В роботі виявлено, що причиною виникнення часткових розрядів є нерівномірність розподілу напруженості електричного поля. Це послугувало причиною для подальшого дослідження напруженості електричного поля прохідного ізолятору та його моделювання. В результаті моделювання, було виявлено точки концентрації напруженості електричного поля в прохідному полімерному ізоляторі та позначено їх, як точки впливу для підвищення електричної міцності прохідного полімерного ізолятора. Наукова новизна. Наукова новизна виконаної науково-дослідної роботи полягає у використанні моделювання електричного поля полімерного прохідного ізолятору, як інструмента для виявлення слабких місць в його конструкції, при впливі на котрі можна буде спостерігати позитивний вплив на його технічні характеристики. Практична цінність. Практична цінність виконаної науково-дослідної роботи полягає в тому, що результати дослідження слугують міцним фундаментом для подальшої оптимізації конструкції прохідних полімерних ізоляторів, що призводитиме до позитивного впливу на їх технічні характеристики та зробить їх конкурентними у порівнянні з іншими типами ізоляторів.

Radial diffusion has been established as one of the most important mechanisms contributing to both the acceleration and loss of relativistic electrons in the outer radiation belt, as well as to the supply of particles to the inner radiation belt. In the framework of the “SafeSpace” project, we have used 9 years (2011–2019) of multi-point magnetic and electric field measurements from THEMIS A, D and E satellites to create a database of radial diffusion coefficients (DLL) and ultra-low-frequency (ULF) wave power spectral densities (PSDs) spanning an L∗ range from 3 to 8. In this work we investigate the dependence of the DLL on the various solar wind parameters, geomagnetic indices and coupling functions, as well as the L-shell, during the solar cycle 24. Moreover, we discuss the uncertainties introduced on the estimation of DLL time series by the partial azimuthal coverage provided by in situ measurements. Furthermore, we investigate, via a superposed analysis, the dependence of the DLL on solar wind drivers. We show, for the first time to the best of our knowledge, that the interplanetary coronal mass ejection (ICME)-driven disturbances accompanied by high solar wind pressure values combined with intense magnetospheric compression can produce DLLB values comparable to or even greater than the ones of DLLE. This feature cannot be captured by semi-empirical models and introduces a significant energy dependence on the DLL. Finally, we show the advantages of using DLL time series by means of numerical simulations of relativistic electron fluxes performed with the Salammbô code and significant deviations in the predictions of several semi-empirical models depending on the level of geomagnetic activity and L-shell.

A 320 x 240 indirect time-of-flight (i-ToF) image sensor with a 5.6-μm two-tap 1.5-V pump gate modulation pixel has been designed. Novel characteristics, such as the optimized pinned layer doping and potential buffer region (PBR) structure with pump gate modulator (PGM), are proposed to achieve a maximum lateral modulation electric field of 1500 V/cm under the front-side illumination (FSI) process. As a result, the proposed time-of-flight (ToF) sensor shows 200-mW power consumption and 54% demodulation contrast (DC) at 50-MHz modulation frequency, depth noise less than 1% with 940-nm illuminator from 0.3 to 3 m.

Solving physics problems for which we know the equations, boundary conditions and symmetries can be done by deep learning. The constraints can be either imposed as terms in a loss function or used to formulate a neural ansatz. In the present case study, we calculate the induced field inside and outside a dielectric cube placed in a uniform electric field, wherein the dielectric mismatch at edges and corners of the cube makes accurate calculations numerically challenging. The electric potential is expressed as an ansatz incorporating neural networks with known leading order behaviors and symmetries and the Laplace's equation is then solved with boundary conditions at the dielectric interface by minimizing a loss function. The loss function ensures that both Laplace's equation and boundary conditions are satisfied everywhere inside a large solution domain. We study how the electric potential inside and outside a quasi-cubic particle evolves through a sequence of shapes from a sphere to a cube. The neural network being differentiable, it is straightforward to calculate the electric field over the whole domain, the induced surface charge distribution and the polarizability. The neural network being retentive, one can efficiently follow how the field changes upon particle's shape or dielectric constant by iterating from any previously converged solution. The present work's objective is two-fold, first to show how an a priori knowledge can be incorporated into neural networks to achieve efficient learning and second to apply the method and study how the induced field and polarizability change when a dielectric particle progressively changes its shape from a sphere to a cube.

This paper proposes a time-domain method of characteristics to simulate the impulse corona with background space charge, and derives the ordinary differential equations of the space charge generated by the impulse corona along the electric field line. The corresponding boundary conditions, the selection of time step and space step, and the update strategy of space charge are given. The calculation result of the impulse corona onset voltage is consistent with the test result, proving that the background space charge has almost no effect on the impulse corona onset electric field which is obtained by Kaptzov's assumption. The q-u curve obtained by simulation is compared with the test results to verify the effectiveness of the simulation method. The simulation method is used to obtain the development process of space charge during the application of the opposite polarity impulse voltage. By analyzing the space charge distribution during the process of impulse corona, and the corresponding microscopic charge distribution and macroscopic charge amount at different corona states, the characteristics of impulse corona are explained.

Frequent failures of transition joints were reported mainly near to the crutch area of the paper insulated cable side of the joints. In this paper, the authors present an estimation of the electric field and temperature distribution in the paper insulated cable side of a transition joint using simulations based on finite element method for 3-D geometry, which, apparently did not get much attention until now. It is found that non-linearities in material properties result in drastic changes in the distribution of electric field. The results indicate electric field enhancement near crutch area. The effect of varying load current, and ambient temperature on the peak electric field has been investigated. The simulations are validated analytically. The results are considered important for utilities and manufacturers.

In this work, a Bi2O2.33-CdS direct Z-scheme heterojunction was fabricated based on energy band engineering. The Bi2O2.33 core nanoflakes were first synthesized by electrodeposition which was followed by an annealing process to fabricate this heterojunction. Then the CdS shell was deposited on Bi2O2.33 nanoflakes utilizing the solution method, during which a suitable concentration of CdCl2 solution was used for forming a homogeneous and continuous integrated CdS shell. A space charge region and an internal electric field from CdS (+) to Bi2O2.33 (−), which drove a direct Z-scheme charge transfer process, were formed at the interface. The Bi2O2.33-CdS exhibited excellent photocatalytic performance for CO2 reduction mainly attributed to the satisfactory photoinduced charge separation and transport efficiency in the direct Z-scheme heterojunction. The photocatalytic CO2 reduction ability of Bi2O2.33-CdS was significantly enhanced compared with single Bi2O2.33 or CdS, with a CO yield rate of ca. 2.9 μmol/(cm2 h) under a 300 W Xe lamp. The reduction of CO2 to CO demonstrated 94.0% selectivity.

In this study, the utilization of an electric field generated by the high voltage discharge plasma over a liquid water surface containing glycine compound to synthesize titanium dioxide (TiO2) nanoparticles was demonstrated. The experiments were conducted in a batch-type system with applied voltages ranging from 18.6 − 23.4 kV under various pressurized gases at room temperature. The results indicated that the applied voltages, applied pulse numbers, and pulsed repetition rates had a significant influence on the decomposition reaction of glycine compounds and titanium rod electrode erosion. The ultraviolet − visible (UV − vis) spectra showed that titanium dioxide nanoparticles could be observed in each solution product, and most of them were brookite-type structures. According to the HRTEM images, TiC was also produced as a nanoparticle product. Based on the experimental results, this process is applicable and could result in advanced metal-based nanoparticle synthesis technology.

The degradations of electrical parameters for depletion mode GaN devices in the cascode configuration under repetitive hard-switching stress are investigated in detail. With the help of TCAD simulations and comprehensive experimental analysis, two different mechanisms behind the degradations are demonstrated. Under a relatively low Vds hard-switching condition, hot electron injection is proved to be the only influence factor, which results in the increase of Rdson under low gate bias voltage. Furthermore, under the low Vds switching condition, influence of different stages on the degradation trend of the device is verified. It is found that the turn-on procedure has a greater degradation risk due to higher energy consumption. However, when Vds is high during hard-switching, the surface trapping effect is triggered due to high electric field at the end of gate field plate, and finally results in the device degradation trend. It results in the increase of the Rdson under high gate bias condition. Therefore, considering the stability and safety of power systems which adopt cascode devices as switches, shorter turn-on time or a soft-switching operation condition should be considered in the design.

Compared with antiferroelectric (AFE) orthorhombic R phases, AFE orthorhombic P phases in NaNbO3 (NN) ceramics have been rarely investigated, particularly in the field of energy-storage capacitors. The main bottleneck is closely related to the contradiction between difficultly-achieved stable relaxor AFE P phase and easily induced P-R phase transition during modifying chemical compositions. Herein, we report a novel lead-free AFE ceramic of (1-x)NN-x(Bi0.5K0.5)ZrO3 ((1-x)NN-xBKZ) with a pure AFE P phase structure, which exhibits excellent energy-storage characteristics, such as an ultrahigh recoverable energy density (Wrec) ∼4.4 J/cm3 at x = 0.11, a large powder density PD ∼104 MW/cm3 and a fast discharge rate t0.9 ∼45 ns. The analysis of polarization-field response, Raman spectrum and transmission electron microscopy demonstrates that the giant amplification of Wrec by ≥177% should be mainly ascribed to the simultaneously and effectively enhanced AFE P-phase stability and its relaxor characteristics, resulting in a diffused reversible electric field-induced AFE P-ferroelectric phase transition with concurrently increased driving electric fields. Different from most (1-x)NN-xABO3 systems, it was found that the reduced polarizability of B-site cations dominates the enhanced AFE P-phase stability in (1-x)NN-xBKZ ceramics, but the almost unchanged tolerance factor tends to cause the AFE R phase to be induced at a relatively high x value.

ABSTRCT Sustainable light energy from ambient environment has attracted particular attention to meet the ever-growing need of small-scale electronics. The modulation of intercorrelated thermal and electronic transport is one of the crucial aspects for reliable photothermoelectric electronics. Herein, a defect-promoted photothermoelectric effect is demonstrated in densely aligned ZnO nanorod array with rich lattice defects. The defect-rich ZnO device delivers high electrical conductivity and large Seebeck coefficient to enable significant improvement of photothermoelectric energy conversion and self-powered photodetection. The position sensitivity reaches approximately 0.19 mV·mm-1, and the temperature gradient induced electric field makes up for the suppression in the photothermoelectric process. The synergism between intrinsic defects and extra temperature field plays an important role in promoting the photothermoelectric properties of dense ZnO nanorod array. This study is interesting for interpreting the thermo-phototronic phenomena as well as demonstrating the possibility of defect engineering and phonon engineering to enable highly efficient light energy scavenging and self-powered photodetection.

Insulators are the most crucial part of power systems. The insulation performance of insulators is vital for the sustainability of power systems. Recently, silicone rubber (SiR) insulators are used frequently in all sections of the power systems. In this paper, a SiR insulator currently used in power transmission systems has been analyzed under combined AC-DC voltage using the finite element method. In the analysis, positive and negative DC voltages in different amplitude ratios were superimposed over the phase-earth operating voltage of the insulator. Analyses in the study were made in time-dependent. Only DC voltage was applied to the insulator for the first 60 s, AC + DC voltage was applied between 60 to 120 s. Thus, the electric field behavior of the SiR insulator under combined AC-DC voltage has been obtained. The change of electric field based on positive and negative DC components was investigated. As a result of the study, the effect of the polarity of the DC component in the combined voltage was observed. As a result, effect of the polarity of the DC component in the combined voltage on the maximum electric field intensity was observed. (C) 2021 The Author(s). Published by Elsevier Ltd.

The present work exhibits a novel design of surface plasmon resonance (SPR) biosensor, which comprises CaF2 prism, TiO2, metal (Ag/Au), PtSe2, 2D materials (graphene/ transition metal dichalcogenides (MoS2/WS2)) and sensing medium, for point-of-care detection of various stages of malaria diseases. The transfer matrix method (TMM) is employed to examine the angular reflectivity of the proposed structure after judiciously optimizing the layer thicknesses and layer numbers. Phase interrogation technique is utilised to validate the position of occurrence of resonance angles. Additionally, the proposed SPR structure is designed using COMSOL Multiphysics, to assay the electric field intensity and electric field enhancement factor near the edge of 2D material-sensing layer interface. Simulation upshots revealed that the use of new class of 2D materials catapult the sensor performance to a new height compared to the traditional SPR configuration. A maximum sensitivity of 240.10°/RIU, quality factor of 78.46 RIU-1 and detection accuracy of 1.99 is attained for Ag-based SPR configuration with bilayer of WS2. Sensing parameters are compared with previously reported works to prove the superiority of the present research. Moreover, the real-time and label-free detection of malaria diseases makes the suggested sensor worth to fabricate as a SPR chip with the recent nanofabrication technologies.

SUMMARYRuddlesden-Popper (RP) perovskites are two-dimensional semiconductors for high performance devices. In this work, we report a long in-plane charge carrier diffusion length in 2D RP perovskite single crystals probed by scanning photocurrent microscopy. Carrier diffusion lengths of 7~14 µm are observed when the number of PbI6-2 octahedrons between organic spacers increases from 1 to 3. By detailed light intensity and electric field-dependent photocurrent measurements, we attribute the observed long diffusion length to the dominating dissociated free carrier transport. This is further validated by time-resolved photoluminescence measurements where the decay lifetime increases in the presence of an electric field. From our experiments, we conclude that the in-plane transport in RP perovskites is efficient because of the partial free carrier generation overcoming strong excitonic effects. Our results suggest that semiconducting devices fabricated from RP perovskite single crystals can be as efficient as their 3D counterparts.

Modeling of electromagnetic wave propagation inside a gas-insulated switchgear structure can be helpful for understanding and improving the utilization of partial discharge detection by providing information to help determine more optimal positioning of ultra-high frequency sensors. This paper studies the effect of insulating spacers, L- and T-type structures on electromagnetic wave propagation by simulating the time dependent wave propagation behavior for these arrangements within a gas-insulated switchgear busbar geometry. The attenuation characteristics and time delays produced by spacers, L- and T-type structures for partial discharge electromagnetic wave propagation behavior are presented. Emphasis is placed on comparison of attenuation characteristics and time delay between different observation points along the busbar both before and after the 90° bends formed by L- and T-type structures. Moreover, a comparative analysis of the radial electric field at the gas-insulated switchgear tank and its rate of change with time is also conducted. The paper demonstrates that if the location of the ultra-high frequency sensor is chosen appropriately based on knowledge of the physical structures, the attenuation effects introduced by L- and T-type structures could be reduced.

In this communication, we propose glide-symmetric double-layer spoof surface plasmon polaritons (SSPPs) structures for controlling the field confinement of SSPPs to achieve antenna beam manipulation with a large frequency-scanning angle. By changing the shape of the glide-symmetric double-layer SSPPs, we can control the electric field confinement of the SSPPs to emerge symmetric or asymmetric distribution. Hence, the proposed SSPPs structure can produce electromagnetic leakage on both sides or single side, furtherly achieving dual-beam or single-beam radiation. Two SSPPs antennas with dual beams and single beam are designed, fabricated, and measured. Both the dual-beam antenna and single-beam antenna operate from 9 GHz to 24 GHz. Within the working band, the dual-beam antenna accomplishes 134.3° (-90° to +44.3°) beam-scanning angle with the realized gain of 8.03-12.17 dBi, while the single-beam antenna achieves 119° (-77.9° to 41.1°) beam-scanning angle with 10.31-14.24 dBi realized gain. The simulated and experimental results verified the beam manipulation and large frequency-scanning angle in antenna design.

Two-dimensional (2D) moire materials provide a new solid-state platform with unprecedented controllability for studies of correlated quantum phenomena. To date, experimental studies have focused on the correlated electronic states; the correlated bosonic states in moire materials have remained practically unexplored. Here, we report a correlated dipolar excitonic insulator, a charge insulating state driven by the formation of excitons, in a Coulomb-coupled WSe2 monolayer and WSe2/WS2 moire bilayer at total hole doping density equal to the moire density. The system is a Mott insulator when all the holes reside in the moire layer. Under an out-of-plane electric field, the holes can be continuously transferred to the WSe2 monolayer, but remain strongly bound to the empty moire sites; they form an interlayer exciton fluid in the moire superlattice under a particle-hole transformation. We identify the phase space and determine the charge gap energy of the excitonic insulating state by optical spectroscopy and capacitance measurements, respectively. We further observe the emergence of local magnetic moments in the WSe2 monolayer induced by the strong interlayer Coulomb correlation. Our demonstration of an exciton fluid in a lattice paves the path for realizing correlated bosonic quantum phenomena described by the Bose-Hubbard model in a solid-state system.

Novel back-illuminated modified uni-traveling- carrier photodiodes (MUTC-PDs) are reported to demonstrate wide bandwidth and high output power performance at D-band (110–170 GHz) regime. A comprehensive design model is employed to predict and tune the frequency response by incorporating coplanar waveguides (CPWs) with different inductive peaking effects. As a demonstration, 4.5-μm-diameter photodiodes with two types of CPWs are fabricated to exhibit different frequency response profiles. Both PDs exhibit a 3-dB bandwidth over 150 GHz and the measured frequency responses are in excellent agreement with simulations. Thanks to the proper design of the CPW electrodes, the two PDs exhibit an output power roll-off of only 4.3 dB and 4.8 dB from dc to 170 GHz, respectively, and high saturation performance is maintained over the broadband frequency range of 130–170 GHz.

Nowadays, carbon frameworks derived from natural biomaterials have attracted extensive attention for electromagnetic interference (EMI) shielding due to their renewability and affordability. However, it is critical and challenging to achieve effective regulation of shielding effectiveness (SE) as well as weaken the strong EM reflection of highly conductive biomass-based carbon materials. Herein, commercial cotton pads with oriented structure were selected as carbonaceous precursor to fabricate aligned carbon networks by pyrolysis, and the EMI SE of the samples with increased temperature of 800-1000°C can be accurately controlled in the effective range of ∼21.7-29.1, ∼27.7-37.1 and ∼32.7-43.3 dB with high reflection coefficient of >0.8 by changing the cross-angle between the electric-field direction of incident EM waves and the fiber-orientation direction due to the occurrence of opposite internal electric field. Moreover, the further construction of Salisbury absorber-liked double-layer structure could result in an ultra-low reflection coefficient of only ∼0.06 but enhanced SE variation range up to ∼38.7-49.3 dB during the adjustment of cross-angle, possibly due to the destructive interference of EM waves in the double-layer carbon networks. This work would provide a simple and effective way for constructing high-performance biomass carbon materials with adjustable EMI shielding and ultra-low reflectivity.

Owing to the complex composition architecture of these solid solutions, some fundamental issues of the classical (1−x)Bi1/2Na1/2TiO-xBi1/2K1/2TiO3 (BNT-xBKT) binary system, such as details of phase evolution and optimal Na/K ratio associated with the highest strain responses, remain unresolved. In this work, we systematically investigated the phase evolution of the BNT-xBKT binary solid solution with x ranging from 0.12 to 0.24 using not only routine X-ray diffraction and weak-signal dielectric characterization, but also temperature-dependent polarization versus electric field (P-E) and current versus electric field (I-E) curves. Our results indicate an optimal Na/K ratio of 81/19 based on high-field polarization and electrostrain characterizations. As the temperature increased above 100 °C, the x = 0.19 composition produces ultrahigh electrostrains (> 0.5%) with high thermal stability. The ultrahigh and stable electrostrains were primarily due to the combined effect of electric-field-induced relaxor-to-ferroelectric phase transition and ferroelectric-to-relaxor diffuse phase transition during heating. More specifically, we revealed the relationship between phase evolution and electrostrain responses based on the characteristic temperatures determined by both weak-field dielectric and high-field ferroelectric/electromechanical property characterizations. This work not only clarifies the phase evolution in BNT-xBKT binary solid solution, but also paves the way for future strain enhancement through doping strategies. © 2021 The Chinese Ceramic Society. This work was supported by the National Natural Science Foundation of China (Grant Nos. 51772239 and 51761145024 ) and the Fundamental Research Funds for the Central Universities ( XJTU ). The SEM work was done at International Center for Dielectric Research (ICDR), Xi'an Jiaotong University, Xi'an, China.

This paper presents the characteristics of HgCdTe mid-wavelength infrared (MWIR) electron-initiated avalanche photodiodes (e-APDs) as a function of temperature under different biases. The devices show a low dark current density of the order of ${10^{ - 7}} \text{A/cm}^2$ at 80 K when the reverse bias voltage is below 4 V, with an exponential gain above 100 at − 8 V. Low excess noise factor of around 1.2 is also demonstrated for the devices at 80 K. The dark current and gain characteristics at different temperatures are analyzed, along with the device simulation results. A varied-temperature impact ionization model for MWIR e-APD devices is adopted based on the experimental results. In addition, a significant increase of the dark current in the APD device is observed at high temperature under large reverse bias, which can be associated with the local electric field redistribution due to the accumulation of holes in the depletion region at high temperatures. The analysis presented in this work paves the way to achieve a high operating temperature (HOT) of the HgCdTe APD with further optimization.

A compact tag antenna, which has a geometrical dimension of 31.5 mm × 31.5 mm × 3.2 mm, is constructed using a stacked PILA for metal-mountable applications in the UHF RFID passband. The new antenna is formed by inserting a shorted patch into a PILA structure to create a double-layered inverted antenna, which can be viewed as a cascade of two parallel resonant tanks. An increase in electric field intensity in the antenna structure has brought in sufficient capacitance for reducing the tag resonant frequency effectively to the useful UHF RFID passband. Due to the increase in the antenna reactance, conjugate impedance matching can be easily achieved between the antenna and the microchip. Fine-tuning schemes such as stubs and slits are also incorporated with the proposed tag antenna for adjusting the operating frequency to an exact precision. Measurements show that the proposed tag antenna can achieve a read distance of 7.25 m at an EIRP power of 4 W. The resonance of the proposed tag antenna is found to be very stable and it is insensitive to changes in the backing metal platform.

Herein, Ag1-3xSmxNbO3 (0 ≤ x ≤ 0.025) antiferroelectric ceramics were successfully synthesized by solid state methods. The effect of Sm3+ doping on the structure, property and energy storage performance were studied. With the increasing Sm3+ concentrations, the average grain size decreased. Meanwhile, the stability of high temperature M phases (i.e., the structure between Tf and T3) was expanded, which led to low loss for energy storage. Both of structure analysis and ferroelectric tests revealed the existence of weakly polar/AFE-like phase below Tf. The Sm3+ doping tended to suppress the ferroelectric behavior and expand the stability of antiferroelectricity. Consequently, a significantly enhanced energy storage performance (Wrec = 3.8 J/cm3, η = 73 %) could be achieved in Ag0.97Sm0.01NbO3 ceramic, which was almost 1.5 times larger than that in non-doped AgNbO3 (Wrec = 2.4 J/cm3, η = 45 %) under the similar applied field of 1705 kV/cm ± . In particular, the performance of the ceramic showed great temperature stability with variation of ± 5 % from 25 °C to 125 °C. These results indicated that the Ag0.97Sm0.01NbO3 ceramic could be an ideal lead-free candidate used in the energy storage field.

We fabricated Bi0.5(Na1-xKx)0.5TiO3 (BNKT) [x = 0.16–0.24] relaxor ferroelectric ceramics that undergo a transition from the non-ergodic state (NR) to the ergodic state (ER) using a conventional solid-state reaction method. Structural analysis was conducted using X-ray diffraction (XRD), and the electrical properties related to the polarization (P) and strain (S) resulting from the external electric field were analyzed. With an increase in the component ratio x, from 0.16 to 0.24, the remnant polarization (Pr) reduced continuously from ∼18 to ∼3 μC/cm2, respectively. Concomitantly, the form of the S-E loops changed from a butterfly-like shape to a sprout shape (in which the negative strain value (Sneg) that approaches 0 appears as a special feature), suggesting that the NR of the BNKT relaxor ferroelectric ceramic at x = 0.16 transitions to the ER as the composition ratio x increases. In particular, for x = 0.20, the inverse piezoelectric coefficient (d33*) achieved a maximum value of 386 p.m./V, while the value of the Pr was relatively low at ∼ 6 μC/cm2. To investigate the possible application as a wearable energy harvester, BNKT ceramic powders of various compositions were mixed with polydimethylsiloxane (PDMS) to fabricate flexible generator devices. The change in the output voltage and current as a function of the composition ratio x had a similar tendency as the change in the value of d33*, suggesting that the ER of relaxor ferroelectric ceramics with a large strain value is suitable for application in wearable energy harvesters.

The purpose of this study is to show the validity of the simulation result for particle charge and trajectory in an ESP with multiple wire electrodes.The ESP in this study has wires-and-plates configuration composed of three high-voltage application wire electrodes placed between grounded plate electrodes with a gap of 15 mm. The potential, the electric field intensity and the negative ion density were calculated by coupled analysis of Poison’s and current- continuity equations. The fundamental equation of flow field considering the ionic gas flow was a k-ω turbulence flow model. The charge of the particles was calculated from the differential equations of the electric and diffusion charging equations, taking into account the temporal and spatial electric field and ion density. The charged particle trajectory in the ESP was analyzed by an equation of motion considering fluid drag force and Coulomb’s force. In the measurement of the charged particle trajectory, oil mist as the tracer particle was mixed into the gas flow, and analyzed by a particle image velocimetry (PIV) using the software.As a result, the analysis value of the current density distribution on the surface of the grounded plate electrode agreed with the experimental value. The analysis results of the particle trajectory showed that the particle velocity increased, and moved toward the grounded plate electrode as the discharge power increased. The x and y components of particle velocity measured using PIV almost agreed with the simulated result. These results indicated the validity of the simulation result for charged particle trajectory, which was calculated by fitting the analyzed corona current to the experimental value, in the gas flow considering the ionic flow in an ESP with multiple wire electrodes.

The paper studies the radiation effects on the junction leakage random telegraph signal (JL-RTS). Using arrays of transistors, a statistical study of the phenomenon in MOSFETs source p-n junctions is performed and the impact of the electric field, the type of irradiation, and the source design is investigated. It appears that although JL-RTS originate both from the DDD- and TID-induced defects, the latter is the dominant contribution in MOSFETs sources due to an electric field enhancement. The paper then completes the study with ab initio molecular simulations to investigate the origin of the JL-RTS. The results advocate for the adoption of the structural fluctuation model over the state charge fluctuation model to describe the origin of the phenomenon.

Lead-free relaxor bulk ceramics (LFRBCs) have the advantages of environment-friendliness, diffuse phase transition near room temperature (RT) and large heat absorption capacity, so as to be candidates for medium and large electric refrigeration and cooling equipment. Although considerable efforts have been made to explore LFRBCs with a large adiabatic temperature change (ΔT) near room temperature, the RT ΔT of LFRBCs is still too weak, baffling their practical applications. In addition, common strategy for achieving a large RT ΔT is mainly tuning phase transitions by compositional engineering. Unfortunately, this strategy is not enough to realize the required properties for EC cooling devices. In this work, based on the general phenomenological expressions of EC effect, we proposed a new strategy, i.e. coordinated regulation of phase transitions and applied electric fields, to achieve a large RT ΔT and a wide using temperature range in LFRBCs simultaneously. Encouragingly, the ΔT calculated using the indirect method inclines from 0.96 K to 1.7 K ranging from 300 K to 360 K in 0.25 mol. % La3+ doped Ba(Zr0.2Ti0.8)O3 ceramic under electric field change of 150 kV cm−1, which is much higher than that calculated using the indirect method so far in many LFRBCs designed using previous strategy for EC refrigeration, demonstrating a big step in LFRBCs for EC refrigeration. The large RT ΔT and broad operating temperature range are mainly attributed to diffuse phase transition near room temperature and a high applied electric field. Most importantly, this work provides a significant guideline to develop new LFRBCs with high comprehensive EC properties for high-efficiency cooling devices, which will bring a series of new LFRBCs with a large room-temperature ΔT in a wide temperature range for next-generation refrigeration in the future.

In this paper we investigate temporal linear instability and absolute/convective instability of coaxial viscoelastic jets in the presence of a radial electric field. With a leaky dielectric model to describe the finite conductivity of the outer liquid, both axisymmetric instability and nonaxisymmetric instability are studied and compared to determine the predominant mode in the jet instability. For relatively small wavenumbers, the electric field suppresses the axisymmetric instability, while it enhances axisymmetric instability for relatively large wavenumbers. As the electric field increases, the instability mode tends to be a short wave. The elasticity of the inner and outer liquid is found to contribute to the coaxial jet instability, and the increase of the inner-liquid elasticity is discovered to allow the para-sinuous mode to predominate over the helical mode. Furthermore, the spatiotemporal instability analysis indicates that under weaker electric fields the axisymmetric mode is convectively unstable, but becomes absolutely unstable when the electric field is relatively strong, when the outer liquid has a certain degree of elasticity. While the nonaxisymmetric mode is found to be always absolutely unstable. A boundary line between absolute and convective instability is given on the parameter space of the Deborah number (relative relaxation time) of the outer liquid and the electrical Euler number. Our results in temporal and spatiotemporal instability analysis can be useful for understanding the origin of the different modes and desired mode control in coaxial electrosipinning.

0-3 composites containing high permittivity ceramic particles and high breakdown strength polymer have aroused extensive concern for energy-storage application. In this research, flexible composite films were fabricated through incorporating of strontium titanate (SrTiO3) platelets (P-ST) and poly(vinylidene fluoride) (PVDF), and the effect of P-ST content on the dielectric and energy storage performances were researched systematically. It was found that at the relatively low electric field of 350 MV/m, the composite with 1 wt% P-ST exhibited an increased discharged energy density of 9.48 J/cm3, exceeding most of the current reports at the same electric field. And the distribution of local electric field and local polarization of composite films were simulated by COMSOL Multiphysics. This work provided a reference for polymer-based composite films featuring high energy storage property at relatively low applied electric field, which could reduce the possibility of failure for capacitors.

The corrosion mechanisms that occurred between the slag-line and mold flux under the applied external electric field are studied. The results show that the slag-line can be effectively protected when the slag-line is connected to the negative electrode, and the graphite as an auxiliary electrode is connected at positive potential. Under the applied negative electric field, a thick protective adhesion layer is formed on the surface of the slag-line due to the electrochemical reactions. Additionally, the slag-line material is further reacted with surface of the formed protective layer and generates another interface reaction layer. Under the effect of double protective layers, the slag-line can be perfectly devoid of corrosion attack under the negative electric field. The performance of the slag-line and the production time of the whole continuous casting can be improved. The external electric field is expected to be a new technical approach to alleviate corrosion of the SEN.

In the preparation process for advanced ceramics, how to reduce the sintering temperature, shorten the processing time and refine grains is the key to obtaining high-performance ceramic materials. The flash sintering (FS) provides an effective method to solve this issue. Here, (Zr + Ta) co-doped TiO2 colossal permittivity ceramics were successfully fabricated by conventional sintering (CS) and flash sintering under electric fields from 500 V/cm to 800 V/cm. The flash behavior, sintered crystal structure and microstructure, dielectric properties, and varistor characteristics were systematically investigated. The effects of the applied electric fields on the above behaviors were discussed. The results show that flash sintering can reduce the sintering temperature by 200 °C, decrease the processing time by 10 times and reduce grain sizes in TiO2 ceramics. All sintered samples were single rutile structures. Flash sintering led to similar electrical properties to conventional sintering. In the flash-sintered samples, with increasing the electric field, the permittivity of co-doped TiO2 ceramics increased at a frequency of 103–104Hz. The flash-sintered sample under an electric field of 800 V/cm possessed the best comprehensive properties, a dielectric permittivity of >105, a dielectric loss of ∼0.77 at 103 Hz, and a nonlinear coefficient of 5.2.

The use of semiconductors to construct heterojunctions to suppress the rapid recombination of photogenerated charges and holes is considered to be an effective way to improve the efficiency of photocatalytic hydrogen evolution. Herein, cobalt sulfide (CoSx) nanoparticles are cultivated in situ in the folds of three-dimensional flower-like nickel-aluminium layered double hydroxides (NiAl-LDHs) using a facile solvothermal method. The hydrogen production rate of the binary CoSx/NiAl-LDH heterojunction reaches 3678.59 μmol/g/h, which is 83.74 and 22 times the rates of CoSx and NiAl-LDH, respectively. The unique three-dimensional structure of NiAl-LDH facilitates the growth of CoSx and shortens the transfer pathway of photogenerated electrons. More importantly, the built-in electric field formed at the interface and the S-type charge transport mechanism caused by the bending of the energy band enhance not only charge separation but also maintain the strong oxidation ability of the holes. In this study, the newly designed S-scheme heterojunction offers a new strategy for enhancing photocatalytic water splitting.

With the development of energy-storage technology and power electronics industry, dielectric capacitors with high energy density are in high demand owing to their high power density. Especially for ferroic dielectrics (including ferroelectrics and antiferroelectrics) showing dipole moments in the perovskite unit cells, large dielectric response under electric fields makes them own outstanding potentials for achieving high energy-storage density. Particularly, destroying long-range ferroelectric/antiferroelectric ordering by enhancing compositional disorder is found to be effective for extremely improving energy-storage properties (both high recoverable energy-storage density and efficiency), because these macroscopic-nonpolar nanodomains are highly polarizable under strong external electric fields. Moreover, owing to the heterogeneous structure induced dielectric relaxation characteristics, excellent temperature stability can be achieved simultaneously. The recent developments of (anti)polar nanoregions with different possible local symmetries in various lead-free perovskite-structured dielectrics have been summarized in this review, together with the achieved energy-storage properties based on them. This review would provide a guidance for preparing high-performance energy-storage capacitors by local-structure engineering for next-generation pulse power applications.

In order to restrain the clogging in submerged entry nozzle (SEN) during the casting of rare earth steel, La–Ce alloy is explored in this work. Effects of external electric field on reaction behavior of La–Ce alloy with SEN are investigated. Results show that chemical mechanisms between La–Ce alloy and SEN during the reaction cannot be altered by electric field due to strong chemical reaction force of rare earth elements against SEN, but the speed of chemical reaction can be controlled by electric field, resulting in significant changes in reactions. By the application of positive electric field, stable and dense interface reaction layer can be formed on the surface of SEN. Specifically, newly formed protective layer can limit the formation of clogging at initial stage to continue till the end of the reaction. Proposed novel approach of external positive electric field can be expected to solve the clogging of SEN during rare earth steel casting process.

Recent use of ion currents as a sensing strategy in the mechanized oxyfuel cutting process motivated a series of studies which revealed that the steel work piece contributes secondary ions in addition to the primary ions classically identified in the oxyfuel flame. In this work, we present a computational model that has linked carbon-related chemi-ions as a source of secondary ions in preheating stage of oxyfuel cutting process subject to electric bias voltages. The flames' response to the electric field at different positive and negative polarities manifested a better understanding of the physical behavior of current-voltage (i-v) relationship. While copper surface exhibits stable and repeatable i-v characteristics, sporadically enhanced current was observed in positive saturation regime for steel surface, and this is believed to be due to the presence of secondary chemi-ions. To this extent, a source term of gaseous carbon has been assigned to mimic the ‘work surface’ reactions. The hypothesis is that since carbon is an important element, it will be diffusing out of the steel surface and evaporate into the flame.

This paper studies the AC pollution breakdown characteristics of the EGLA and broaden current knowledge of pollution flashover. Compared with the flashover of the normal insulator, three kinds of specificity of the EGLA were found. Firstly, the pollution flashover process can be divided into three categories. Secondly, the wet flashover voltage, Uf _wet, of the novel insulator is higher than the dry flashover voltage, Uf _dry. Thirdly, the piecewise fitting methods with aESDD^-b+d and aESDD^-b+ cESDD^-d are more suitable for fitting the empirical formula of flashover voltage. Furthermore, to explain specificity, the electric potential and electric field distribution are calculated based on the finite element method. Calculated results indicate that when the EGLA is covered with a 0.5mm water film, the maximum electric field intensity decreased from 2.17 kV/cm to 1.99 kV/cm. Also, U_arrester (the withstand voltage of the insulation section) was obtained from the tests and it presents a discontinuous and random increasing trend until flashover occurs, which is considered to be one of the important reasons for the specificity. Besides, based on the Obenaus model and Hampton's criterion, we further analyzed the arc development process by a simplified plate model