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The emergence of planar electroluminescent diodes (including polymer light‐emitting diodes, organic light‐emitting diodes, quantum‐dot light‐emitting diodes, and perovskite light‐emitting diodes) is causing a revolution in displays, lighting, and wearable electronic devices. Continuous advancement in the comprehension and management of charge carrier dynamics in these devices has led to several significant breakthroughs, including diodes with ultrahigh luminance, memory devices, and amplified spontaneous emission. Transient electroluminescence (TrEL) spectroscopy is a relative powerful technology to investigate charge dynamics, including transport, distribution, and storage of charge carriers, in electrically‐driven planar light‐emitting diodes (LEDs). The aim of this review is to revisit the principle and applications of TrEL spectroscopy in planar electroluminescent diodes, and to evaluate the reliability of various parameters extracted using this technology. A particular focus is on electroluminescence response time, charge‐carrier transport and storage, and exciton species. First, the principle and equipment system of the TrEL, as well as specific attention during TrEL measurements are described in detail, following by the applications TrEL spectroscopy in planar LEDs. Further development on the TrEL technology is discussed in the third section. Finally, a summary and outlook for the TrEL are shown and challenges faced by the TrEL spectroscopy are also highlighted. [ABSTRACT FROM AUTHOR]

Abstract Affected by inverter station commutation failure and fast control, line fault characteristics are obviously different from traditional AC transmission line fault characteristics. The existing protection methods for AC line connected to line commutated converter based high voltage DC (LCC‐HVDC) inverter station (ACLs) have the problems of complex setting, weak anti‐noise and high demand for data synchronization. This paper proposes a pilot protection scheme based on high‐frequency transient current waveform similarity. Firstly, with analyzing the fault traveling wave propagation process, the obvious differences are found in the transient current waveforms at both ends of the line when internal and external faults occur. Then the similarity of transient current waveforms is measured with the improved longest common similar subsequence (LCSS) method. And the weak high‐frequency current is extracted with the improved synchronous squeezed S‐transform (SST) method. Finally, a large number of power systems computer aided design (PSCAD) simulation results show that the proposed protection method does not require strict data synchronization, has strong anti‐noise performance, and is tolerant to the influence of abnormal point fluctuations.

Affected by inverter station commutation failure and fast control, line fault characteristics are obviously different from traditional AC transmission line fault characteristics. The existing protection methods for AC line connected to line commutated converter based high voltage DC (LCC‐HVDC) inverter station (ACLs) have the problems of complex setting, weak anti‐noise and high demand for data synchronization. This paper proposes a pilot protection scheme based on high‐frequency transient current waveform similarity. Firstly, with analyzing the fault traveling wave propagation process, the obvious differences are found in the transient current waveforms at both ends of the line when internal and external faults occur. Then the similarity of transient current waveforms is measured with the improved longest common similar subsequence (LCSS) method. And the weak high‐frequency current is extracted with the improved synchronous squeezed S‐transform (SST) method. Finally, a large number of power systems computer aided design (PSCAD) simulation results show that the proposed protection method does not require strict data synchronization, has strong anti‐noise performance, and is tolerant to the influence of abnormal point fluctuations. [ABSTRACT FROM AUTHOR]

Two-dimensional material-based field-effect transistors are promising for future use in electronic and optoelectronic applications. However, trap states existing in the transistors are known to hinder device performance. They capture/release carriers in the channel and lead to hysteresis in the transfer characteristics. In this work, we fabricated MoTe2 field-effect transistors on two different gate dielectrics, SiO2 and h-BN, and investigated temperature-dependent charge trapping behavior on the hysteresis in their transfer curves. We observed that devices with SiO2 back-gate dielectric are affected by both SiO2 insulator traps and MoTe2 intrinsic bulk traps, with the latter becoming prominent at temperatures above 310 K. Conversely, devices with h-BN back-gate dielectric, which host a negligible number of insulator traps, primarily exhibit MoTe2 bulk traps at high temperatures, enabling us to estimate the trap energy level at 389 meV below the conduction band edge. A similar energy level of 396 meV below the conduction band edge was observed from the emission current transient measurement. From a previous computational study, we expect these trap states to be the tellurium vacancy. Our results suggest that charge traps in MoTe2 field-effect transistors can be reduced by careful selection of gate insulators, thus providing guidelines for device fabrication. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Refrigeration is the property of Journal of Refrigeration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Many neurons that fire high‐frequency action potentials express specialized voltage‐gated Na channel complexes that not only conduct transient current upon depolarization, but also pass resurgent current upon repolarization. The resurgent current is associated with recovery of transient current, even at moderately negative potentials where fast inactivation is usually absorbing. The combined results of many experimental studies have led to the hypothesis that resurgent current flows upon repolarization when an endogenous blocking protein that occludes open channels at depolarized potentials is expelled by inwardly permeating Na ions. Additional observations have suggested that the position of the voltage sensor of domain IV regulates the affinity of the channel for the putative blocker. To test the effectiveness of a kinetic scheme incorporating these features, here we develop and justify a Markov model with states grounded in known Na channel conformations. Simulations were designed to investigate whether including a permeation‐dependent unblocking rate constant and two open‐blocked states, superimposed on conformations and voltage‐sensitive movements present in all voltage‐gated Na channels, is sufficient to account for the unusual gating of channels with a resurgent component. Optimizing rate constant parameters against a wide range of experimental data from cerebellar Purkinje cells demonstrates that a kinetic scheme for Na channels incorporating the novel aspects of a permeation‐dependent unblock, as well as distinct high‐ and low‐affinity blocked states, reproduces all the attributes of experimentally recorded Na currents in a physiologically plausible manner. [ABSTRACT FROM AUTHOR]

The present study proposes a methodology for improving terahertz (THz) radiation through the utilisation of a laser directed towards a graphene strip that has been coated onto a GaAs structure. The presence of a non-uniform voltage results in the production of a transient current when the laser interacts with GaAs material. The generation of THz radiation is attributed to the current that is produced along the length of GaAs structures. Concurrently, a portion of the laser beam interacts with the graphene strip, inducing a surface plasma wave (SPW) that propagates along the surface of the graphene. The amplitude of the SPW experiences an exponential decay as it travels away from the interface in both the media. The impact of the transverse electric field of surface plasmon waves in graphene on the transient current in GaAs material has been observed to enhance THz radiation. The frequency of the SPW increases in a parabolic manner as the graphene strip increases with rises with rise in propagation vector. The plasmonics (Graphene plasmons: GPs) approach used for the proposed model enables us to making the emitted radiation suitable for Terahertz spectroscopy, imaging and non-destructive testing, Highspeed data transfer, Terahertz microscopy, Terahertz microscopy, Terahertz microscopy, Quantum technology.

Porous Ni-doped copper oxide (NCO) photocatalyst has been produced using chemical activation and metal doping techniques. Structural, optical, morphological, and electrical analyses were performed on copper oxide (CO) and porous NCO photocatalysts. The monoclinic-phased, UV/Vis light-triggered, electrically conductive, and porous-surfaced NCO photocatalyst was successfully synthesized, according to a detailed physicochemical investigation. The photo-decomposition abilities of synthetic porous NCO and counterpart CO photocatalysts were investigated and compared using Allura red (AR). According to the photocatalytic study, the porous NCO photocatalyst outperformed its counterpart (CuO) and eliminated 91.4% (adsorption: 18%; decomposition: 79%) of the AR dye in 48 min. Over the porous NCO photocatalyst, the AR dye disintegrated at a rate of 0.024 min−1, which is more than 1.84 times quicker than the rate of disintegration over the CO photocatalyst. The porous NCO photocatalyst, as synthesized, preserved 88% of its photocatalytic activity after five recyclability tests and had remarkable electron-hole separation activity, according to reusability tests and transient-photocurrent measurements. Also, the radical capture experiment suggested that superoxide and hydroxyl are important for porous NCO's photocatalytic activity. According to the findings of this research, the synthesis of ferromagnetic metal-doped and porous semiconductive materials has a great potential for azo dye breakdown, which makes it an efficient, cost-effective, and environmentally acceptable solution for the clean-up of polluted water. [Display omitted] [ABSTRACT FROM AUTHOR]

The presence of intrinsic ion migration in metal halide perovskites (MHPs) is one of the main reasons that perovskite solar cells (PSCs) are not stable under operation. In this work, we quantify the ion migration of PSCs and MHP thin films in terms of mobile ion concentration (No) and ionic mobility (µ) and demonstrate that No has a larger impact on device stability. We study the effect of small alkali metal A-site cation additives (e.g., Na+, K+, and Rb+) on ion migration. We show that the influence of moisture and cation additive on No is less significant than the choice of top electrode in PSCs. We also show that No in PSCs remains constant with an increase in temperature but μ increases with temperature because the activation energy is lower than that of ion formation. This work gives design principles regarding the importance of passivation and the effects of operational conditions on ion migration. [ABSTRACT FROM AUTHOR]

Herein, cobalt-nickel mixed ferrite (Co 0 · 5 Ni 0 · 5 Fe 2 O 4 , CNFO) and gadolinium doped cobalt-nickel mixed ferrite (Co 0 · 5 Ni 0.5 Gd 0.1 Fe 1 · 9 O 4 , G-CNFO) materials have been synthesized at the nanoscale via the microemulsion technique. The physicochemical features of the CNFO and G-CNFO materials were examined by advanced structural (PXRD and FTIR), morphological (FESEM), elemental (EDX), and optical (UV/Vis and transient photocurrent) studies. Under visible light, the catalytic activity of CNFO and G-CNFO materials was compared using Congo red and Aniline blue dyes as model textile pollutants. The G-CNFO material showed better photocatalytic activity than CNFO material, as it eliminated almost 21% more dye than CNFO material under the same experimental conditions. In order to find the optimal parameter for the experiments, the variables affecting the catalytic properties of the G-CNFO material were investigated in considerable detail. These variables included pH, catalyst dosage, dye concentration, temperature, and irradiation time. Scavenging and transient photocurrent experiments were also carried out in order to determine the key reactive oxygen species and the formation of electron-hole pairs. The G-CNFO mineralized the Congo red dye almost three times faster than its counterpart and showed a negligible loss in its catalytic activity even after five successive catalytic cycles. The combined effects of the G-CNFO material's tuned band structure, high light harvesting abilities, reduced electron-hole recombination, and nanostructured morphology resulted in its enhanced photocatalytic activity. [ABSTRACT FROM AUTHOR]

The mechanism and improvement of transient drain current characteristics of p‐channel low‐temperature polycrystalline silicon driving‐thin film transistor (LTPS DTFT) were studied in this work. The drain current variation with time can be simulated by attenuation of logarithmic index which might be originated from hole trapping and de‐trapping process. Simulation was used to directly correlate the transient Ids characteristics to the density of border trap. We optimized the buffer and gate insulator layer deposition condition, in addition, we applied a fixed bias in TFT bottom gate, the transient Ids decreased from 27% to 15%. [ABSTRACT FROM AUTHOR]

Abstract The access of large‐scale renewable energy and power electronic equipment to the power grid makes the power source and short‐circuit paths possess time‐varying characteristics when faults occur, which has a serious impact on the traditional protection based on power frequency components. Besides, higher requirements are needed for relay protection in the power grid. The transient fault current contains a large amount of fault information. First, the bus capacitance has a strong reflection effect on the high frequency signal, and there are obvious differences in the high frequency component of the fault current of internal and external faults. Next, a transient quantity algorithm based on sequential overlapping derivative transform is introduced. The algorithm can effectively suppress the low frequency component and enhance the high frequency component in the current, which simply and effectively highlights the difference between the transient current of internal and external faults. Finally, through the ratio of high frequency energy of each outgoing line, the fault direction can be accurately determined, and the transient directional pilot protection can be formed. The accuracy of the protection scheme is verified by a large number of simulation experiments.

The ring-shaped DC distribution network based on modular multilevel converter (MMC) has attracted much attention because of its power supply reliability advantage. The stable operation of MMC ring-shaped DC distribution network is closely related to the fast and reliable line protection method. To meet this requirement, a Pearson correlation coefficient protection method based on fault transient current was proposed. First, the line mode components of the current at the beginning and end of the line in the ring-shaped DC distribution network were extracted, and the difference of the line mode current was used to complete the identification of internal and external faults. According to the characteristics of single-pole grounding and double-pole short-circuit faults, using the numerical difference of the correlation coefficient between the positive and negative transient currents of the line, the single and bipolar faults were judged, and the fault pole selection was completed. Finally, a ring-shaped DC distribution network model was built in power systems computer aided design / electromagnetic transients including DC(PSCAD/ EMTDC) for verification. It can operate quickly and reliably within 2 ms, can protect the full length of the line, and has strong resistance to transition resistance. In the case of 40 dB noise, it can still identify faults, has a certain anti-interference ability, and does not strictly require synchronous communication. [ABSTRACT FROM AUTHOR]

The paper inhere presents the implementation of one idea that has been realized during the COVID-19 pandemics in the period from 2019 until 2022 i.e. the implementation of the software product PTC Mathcad in the virtual training of students, illustrating in an interactive and attractive way the surge theory in second order linear electrical circuits. [ABSTRACT FROM AUTHOR]

This work presents the comparison of measurement results for four types of encapsulated high‐efficiency c‐Si solar cells measured by 10 laboratories based in Asia, Europe and North America utilizing a wide range of voltage sweeping methods, which include well‐established procedures that represent good industry practice, as well as recently introduced ones that have not been verified yet. The aim of the round‐robin interlaboratory comparison was to examine the measurement comparability of different laboratories with respect to their measurement methods of high‐efficiency solar cells. A proficiency test was employed to examine the consistency of results and their corresponding uncertainties. The short‐circuit current (ISC) under STC measured by four accredited laboratories was firstly compared. In order to investigate the consistency related to the high device capacitance, the value of the ISC was fixed for all 10 participants. The results of all participant laboratories—compared via En number analysis—generally remained well within [−1; 1], thus indicating consistency between the measured values and the reference values within stated measurement uncertainties. The differences remained within ±1.15% in PMAX and within ±0.35% in VOC for all participants and methods applied. Correlations were observed among the PMAX, VOC, and FF differences from their weighted mean. An analysis of the effects of transient current (dQ/dt) at maximum power point caused by hysteresis effect on the measurement error of PMAX showed a significant linear correlation between error of maximum power and junction voltage sweep rate for heterojunction (HJT) solar cells. This work forms the basis to validate all applied methods and their stated measurement uncertainties. [ABSTRACT FROM AUTHOR]

In an inertia-type motor, a piezoelectric multilayer actuator is espoused to a transient vibration velocity as high as 1.0 m/s during slip time. This vibration velocity makes the inertia-type motors dynamic but not quasi-static. We propose a kinetic model to describe the condition under which slippage can occur between a slider and a stator. The transient current absorbed by the multilayer actuators in a stator during slip time defines the slippage behavior of the slider. A new thickness-mode force factor expression (A33), which is a relation between the transient current and the transient vibration velocity, is described in electrical domain. Impact force acting on a friction coupler produced by the actuators in the stator is proportional to the rate of change in the transient current during the sliding time. Additionally, we present the structure and characteristics of a two-phase inertia-drive-type piezoelectric motor, on which the proposed model was evaluated. Driving the multilayer actuators with truncated and mirrored sawtooth signals enhances the system dynamics. As one actuator expands and the other shrinks, their respective hysteretic nonlinearities are canceled. The motor operating frequency can be as great as 30 kHz and typically load characteristics are unloaded velocity greater than 16.0 mm/s and generated force higher than 3.0 N. [ABSTRACT FROM AUTHOR]

Understanding the response law and mechanism of weak currents stimulated from coal under an impact load is significant for the prediction of coal bumps in deep coal mines. In this paper, the system for the weak current measurement of coal under an impact load is established and the response characteristics of weak currents induced by the deformation of coal under an impact load are investigated. Physical models are established to describe the process of charge transfer and explain the generation mechanism of those currents. The results show that a transient current is stimulated from the coal sample when an impact load is applied, and then, the current decays slowly, tending to be a stable value that is slightly greater than the background current. The weak current flows from the loaded volume to the unloaded volume of the coal and increases with the impact velocity in a negative exponential form. Analysis of weak currents using non-extensive entropy shows that the attenuation of the weak current obeys non-extensive statistical mechanics and the non-extensive parameter q is greater than 2. The carriers are mainly electrons, of which the distribution obeys the tip effect that electrons tend to enrich towards the tip of a crack. The generation mechanism of those weak currents induced by coal deformation is the instantaneous movement of electrons under a density difference caused by the tip effect. Research results can provide a new perspective to understand the electric phenomena of coal under an impact load as well as a new method for coal bump prediction. [ABSTRACT FROM AUTHOR]

In the current study, a method for generating terahertz (THz) radiation using a GaAs structure array and an incident laser is proposed. When a laser beam is directed onto GaAs material, carriers are generated within the material. These carriers, under the influence of an electric field, produce a transient current as they respond to the applied field. The time-varying current is induced in short intervals of picoseconds. Consequently, this induced current functions as a dipole. The calculation of THz emission from a GaAs array involves the application of antenna theory to the photoconductive antenna. This calculation specifically considers the electron mobility constant as the sole factor during the rising of the current density. The phased array of oscillating dipoles is generating coherent terahertz (THz) radiation. The electrical current flowing along the length of these structures is accountable to produce terahertz (THz) radiation, where the entire system acts as phase-array dipole antennae. Laser interaction with a periodic array of GaAs structures has a wide range of applications across various domains, such as imaging, spectroscopy, communications, non-destructive testing, security, biomedical research, and material science.

The access of large‐scale renewable energy and power electronic equipment to the power grid makes the power source and short‐circuit paths possess time‐varying characteristics when faults occur, which has a serious impact on the traditional protection based on power frequency components. Besides, higher requirements are needed for relay protection in the power grid. The transient fault current contains a large amount of fault information. First, the bus capacitance has a strong reflection effect on the high frequency signal, and there are obvious differences in the high frequency component of the fault current of internal and external faults. Next, a transient quantity algorithm based on sequential overlapping derivative transform is introduced. The algorithm can effectively suppress the low frequency component and enhance the high frequency component in the current, which simply and effectively highlights the difference between the transient current of internal and external faults. Finally, through the ratio of high frequency energy of each outgoing line, the fault direction can be accurately determined, and the transient directional pilot protection can be formed. The accuracy of the protection scheme is verified by a large number of simulation experiments. [ABSTRACT FROM AUTHOR]

With the big data and artificial intelligence era coming, SiNx-based resistive random-access memories (RRAM) with controllable conductive nanopathways have a significant application in neuromorphic computing, which is similar to the tunable weight of biological synapses. However, an effective way to detect the components of conductive tunable nanopathways in a-SiNx:H RRAM has been a challenge with the thickness down-scaling to nanoscale during resistive switching. For the first time, we report the evolution of a Si dangling bond nanopathway in a-SiNx:H resistive switching memory can be traced by the transient current at different resistance states. The number of Si dangling bonds in the conducting nanopathway for all resistive switching states can be estimated through the transient current based on the tunneling front model. Our discovery of transient current induced by the Si dangling bonds in the a-SiNx:H resistive switching device provides a new way to gain insight into the resistive switching mechanism of the a-SiNx:H RRAM in nanoscale. [ABSTRACT FROM AUTHOR]

Unique fault behaviors of renewable energy sources (RESs) may lead to the misoperation of traditional pilot protection. To cope with this issue, this article proposes a new pilot protection method using the improved Euclidean distance. For normal operation or external faults, the currents on both ends are completely opposite, so the Euclidean distance of current absolute values on both ends is equal to 0. However, it will be much larger than 0 for internal faults because transient currents on both ends will have a big difference at this time. Therefore, internal and external faults can be detected reliably. In order to facilitate the setting calculation, the Euclidean distance is normalized, and a stability factor is introduced to avoid invalid calculation results. The proposed method can be applied to different RES types and different fault ride through strategies. Meanwhile, it can withstand larger fault resistance and noise interference. Compared with other methods using the RES fault currents, this approach can operate correctly without any additional criteria when the circuit breaker recloses on a permanent fault or RESs output a low power. PSCAD simulation and real-time digital simulator experiment verify this method. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The theoretical analysis of the diffusional electrode for EC' mechanism in the pseudo-first-order catalytic reaction is discussed. The exact, new, closed and compact form of the current profile is derived for this mechanism for all times and with all catalytic rate constants using Danckwerts' expression or the Laplace transform method. The influence of parameters on current is also discussed.

Since neutrons are electrically neutral, the methods used to detect neutrons generally rely on secondary charged particles, which are produced by the interaction of neutrons and neutron conversion materials (such as 6LiF, 10B). In this report, the SRIM code has been used to analyze the ionization properties of $\alpha $ particles and 3H particles traveling through the Silicon Carbide (SiC) diode, and subsequently, the final Bragg ionization distribution has been obtained. Next, according to the obtained ionization distribution of secondary particles, the linear energy transfer (LET) distribution of the secondary particles is extraced accurately. Finally, based on the distribution of LET, Technology Computer Aided Design (TCAD) simulations are utilized to analyze the transient current pulses of thin-film-coated and trench-type SiC diodes. In addition, the effects of particle energy and applied reverse bias on the output pulse characteristics of SiC diodes are also explored. Essentially, this paper augments the understanding of output response from SiC neutron detectors, and for trench-type detectors, the order of output current pulse amplitude decreases significantly and has a long-tail. Therefore, the trench-type detectors not only need a more advanced fabrication process but also require the design of dedicated readout electronics. [ABSTRACT FROM AUTHOR]

Non-isolated bidirectional dc–dc converters (NBDCs) are widely used in energy storage systems. However, the zero-voltage switching (ZVS) for NBDCs is hard to realize by adding auxiliary circuits. The auxiliary current should be larger than the filtering inductor current. Then the auxiliary current causes high conduction losses, which have adverse effects on efficiency. In this paper, a ZVS NBDC with a transient current built-up technique is proposed, where the transient current is built in a very short time by an auxiliary circuit. The average value of the auxiliary current is quite small, which results in low conduction loss. The proposed auxiliary circuit does not result in high current or voltage stresses and does not affect the filtering inductor current. Experimental results show the correctness of the proposed zero-voltage switching method. They also show that the efficiency of the proposed NBDC is higher than that of the hard switching NBDC. [ABSTRACT FROM AUTHOR]

• We investigated a-IGZO TFT current's transient behavior with varying RF power during sputter-deposition. • IGZO film are analyzed through XPS and AFM. • The occurrence level of each component changes sensitively according to RF power. • There exist optimized RF sputter power conditions that improve reliability. The device electrical and transient current characteristics of the amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) are comprehensively investigated according to the radio-frequency (RF) power during the sputter-deposition of IGZO active film. The RF power dependencies of the oxygen vacancy (V O) concentration in IGZO and the surface morphology of IGZO film are analyzed through X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). According to the RF power change in the range of 100 ∼ 250 W, the optimal point in terms of threshold voltage (V T), ON current (I on), field-effect mobility in the linear region (μ FE_lin), hysteresis voltage (V Hys), and the V T shift under current stress (ΔV T) is found to be 200 W. The existence of the optimal power condition originates from the RF-power dependencies of the electron carrier concentration, the density of electron traps in gate insulator (GI), and the interface trap density related to surface roughness. Furthermore, compared to the direct current (DC) current stress (CS) condition, it is found that when V GS rises rapidly, a total transient current ΔI D can be decomposed into three components, i.e., ΔI OS , ΔI BOOST , ΔI DEG. While ΔI OS is attributed to the non-quasi static Fermi-level rising, ΔI BOOST and ΔI DEG result from the donor creation in IGZO and the electron trapping into GI and interface. Noticeably, the occurrence level of each component changes sensitively according to RF power. Our result suggests that the 200 W device has the least overshoot of transient current and shows the best reliability in terms of deterioration due to transient current characteristics. [ABSTRACT FROM AUTHOR]

The transient current in low‐density polyethylene (LDPE) is studied, particularly in the presence of the small organic molecule acetophenone (ACP). Crosslinked LDPE is used extensively in high‐voltage power transmission, and acetophenone is a common byproduct of the crosslinking chemistry. Time‐dependent current measurements of LDPE with and without ACP soaked into the polymer as well as at one or both electrodes are performed by applying step voltages. The results demonstrate that the presence of ACP causes a deviation in the predicted power‐law current decay, suggesting that electron and hole injection at the anode and cathode, respectively, are affected by the presence of this small organic molecule. ACP contributes both to the ionic conduction and charge hopping mechanism. The charge mobility depends on the applied electric field and the sample thickness. The results suggests that the dispersive charge transport phenomenon influences the measured current. This study shows how such a molecule may alter charge transport in polyethylene. [ABSTRACT FROM AUTHOR]

A model of cyclic staircase voltammetry of enzymatic reactions on the rotating disk electrode is developed and the inhibition by the product is investigated. The responses are mostly time - dependent current - potential curves with maxima in the forward but not in the backward branch. If the maxima appear in both branches, the inhibition is potential - dependent either directly or indirectly. The source of the second maximum is explained. [ABSTRACT FROM AUTHOR]

A line-interactive uninterruptible power supply (UPS) system is one of the important installations implemented by industrial users to provide continuous power to sensitive industrial applications. Such loads often come with isolation transformers for voltage matching and protection purposes. Hence, a line-interactive UPS system experiences a serious problem of transient current when it operates under transformer-coupled loading conditions. The occurrence of this transient current can either impair the apparatus itself or turn on the overcurrent safety devices. In any situation, the interruption of electrical power for sensitive industrial loads is unavoidable. So as to keep the uninterrupted power and to eliminate transient current for industrial applications operating under transformer-coupled loading conditions, we propose a single-phase line-interactive UPS system based on a customary current-regulated inverter. The inverter of the proposed UPS system employs an improved current-regulating scheme implemented in a stationary frame of reference which regulates the load current and never let it to increase than a prescribed value as the transformer-coupled loads are turned on. Laboratory test results obtained under various operating and loading conditions of the single-phase line-interactive UPS system verify the operation of the proposed system.

In an inertia-type motor, a piezoelectric multilayer actuator is espoused to a transient vibration velocity as high as 1.0 m/s during slip time. This vibration velocity makes the inertia-type motors dynamic but not quasi-static. We propose a kinetic model to describe the condition under which slippage can occur between a slider and a stator. The transient current absorbed by the multilayer actuators in a stator during slip time defines the slippage behavior of the slider. A new thickness-mode force factor expression (A33), which is a relation between the transient current and the transient vibration velocity, is described in electrical domain. Impact force acting on a friction coupler produced by the actuators in the stator is proportional to the rate of change in the transient current during the sliding time. Additionally, we present the structure and characteristics of a two-phase inertia-drive-type piezoelectric motor, on which the proposed model was evaluated. Driving the multilayer actuators with truncated and mirrored sawtooth signals enhances the system dynamics. As one actuator expands and the other shrinks, their respective hysteretic nonlinearities are canceled. The motor operating frequency can be as great as 30 kHz and typically load characteristics are unloaded velocity greater than 16.0 mm/s and generated force higher than 3.0 N.

With the big data and artificial intelligence era coming, SiNx-based resistive random-access memories (RRAM) with controllable conductive nanopathways have a significant application in neuromorphic computing, which is similar to the tunable weight of biological synapses. However, an effective way to detect the components of conductive tunable nanopathways in a-SiNx:H RRAM has been a challenge with the thickness down-scaling to nanoscale during resistive switching. For the first time, we report the evolution of a Si dangling bond nanopathway in a-SiNx:H resistive switching memory can be traced by the transient current at different resistance states. The number of Si dangling bonds in the conducting nanopathway for all resistive switching states can be estimated through the transient current based on the tunneling front model. Our discovery of transient current induced by the Si dangling bonds in the a-SiNx:H resistive switching device provides a new way to gain insight into the resistive switching mechanism of the a-SiNx:H RRAM in nanoscale.

In this paper, we have developed a system of Time Domain Electric Field Integral Equation (TD-EFIE) for the resolution of a scattering electromagnetic problem by various shapes illuminated by an incident transient wave. The solvability of the TD-EFIE system is based on the Time Domain Method of Moments (TD-MoM) using Galerkin's method in space and time domains. In time domain, a linear combination of Laguerre functions is used as temporal basis functions. In order to approximate the unknown space variation of the transient current, we develop a novel space hybrid basis functions derived from the Rao-Wilton-Glisson function. The elaborated hybrid mesh technique using hexagonal and triangular mesh is applied for various analyzed structures: regular grid for planar structures and irregular grid for curved structures. The validity, the efficiency and the precision of developed meshing techniques are presented and discussed. [ABSTRACT FROM AUTHOR]

Pr0.7Ca0.3MnO3 (PCMO)-based resistive RAM (RRAM) shows promising memory properties like nonvolatility, low variability, multiple resistance states, and scalability. From a modeling perspective, the charge carrier dc current modeling of PCMO RRAM by drift diffusion (DD) in the presence of fixed oxygen ion vacancy traps and self-heating (SH) in Technology Computer Aided Design (TCAD) (but without oxygen ionic transport) was able to explain the experimentally observed space charge limited conduction (SCLC) characteristics, prior to resistive switching. Further, transient analysis using DD+SH model was able to reproduce the experimentally observed fast current increase at ~100 ns timescale, prior to resistive switching. However, a complete quantitative transient current transport plus resistive switching model requires the inclusion of ionic transport. We propose a reaction-drift (RD) model for oxygen ion vacancy-related trap density variation, which is combined with the DD+SH model. Earlier, we have shown that the Set transient consists of three stages and Reset transient consists of four stages experimentally. In this work, the DD+SH+RD model is able to reproduce the entire transient behavior over 10 ns–1 s range in timescale for both the Set and Reset operations for different applied biases and ambient temperatures. Remarkably, a universal Reset experimental behavior, log (I)∝(m × log(t)) where m ≈ −1/10 is reproduced in simulations. This model is the first model for PCMO RRAMs to significantly reproduce transient Set/Reset behavior. This model establishes the presence of SH and ionic-drift limited resistive switching as primary physical phenomena in these RRAMs. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper deals with an advanced electromagnetic radiation approach for analyzing the time-domain performance of grounding systems under pulse excitation currents. The model of the grounding systems presented within this paper is based on the homogeneous Tocklington integro-differential equation for the calculation of the current distribution on the grounding system and Lorentz gauge condition which is used for the grounding system transient voltage calculation. For the solution of the Pocklington integro-differential equation, the indirect boundary element method and marching on-in time method are used. Furthermore, the solution technique for the calculation of the grounding system transient voltage is presented. The numerical model for the calculation of the grounding system transients was verified by comparing it with onsite measurement results. [ABSTRACT FROM AUTHOR]

Clockless integrated circuits, as any type of integrated system, might today carry hardware Trojan (HT) circuits maliciously implanted in the designs during outsourced phases of fabrication. This paper proposes a testing technique dedicated to detect HTs in clockless circuits fabricated in CMOS technologies. The proposed technique applies a well-known machine learning approach – One-Class Support Vector Machine (OC-SVM) – for dealing with the particular current signature features of clockless circuits. Through simulation experiments we show the natural ability of clockless circuits in providing individual current signatures for identifying the presence of HTs. Moreover, the results demonstrate that our testing technique requires no extra circuitry or power ports to detect HTs of a few dozens of transistors in designs under Trojan test with more than 13 thousand transistors. [ABSTRACT FROM AUTHOR]

This paper investigates lightning surges on a distribution line reported using a finite-difference time-domain (FDTD) method. FDTD simulation results show a satisfactory agreement with measured lightning currents when lightning strikes ground nearby a distribution line. The current and voltage characteristics along the line, which were not measured in the test, are calculated by the FDTD simulation. Parametric analysis shows that lightning currents and voltages are dependent on the lightning position, distance from the lightning to the nearest pole, and pole grounding resistance. A large portion of phase-wire voltage is induced by the lightning channel current, and correspondingly, a large portion of phase-wire current is produced by the induced voltage. When the lightning channel is inclined, the peak current and voltage vary by +10% to −10% depending on the inclined angle. The effect of neutral wire position in the line is also investigated, and the induced voltage at the nearest pole to the lightning can be effectively suppressed by installing two neutral wires above and under the phase wires. EMTP simulation results agree qualitatively well with the measurement and FDTD results. [ABSTRACT FROM AUTHOR]

Grounding fault analysis is of vital importance for low voltage direct current (LVDC) supply and utilization systems. However, the existing DC grounding fault model is inappropriate for LVDC supply and utilization system. In order to provide an appropriate assessment model for the DC grounding fault impact on the LVDC supply and utilization system, an LVDC supply and utilization system grounding fault model is proposed in this paper. Firstly, the model is derived by utilizing capacitor current and voltage as the system state variable, which considers the impact of the converter switch state on the topology of the fault circuit. The variation of system state parameters under various fault conditions can be easily obtained by inputting system state data in normal conditions as the initial value. Then, a model solution algorithm for the proposed model is utilized to calculated the maximum fault current, the system maximum fault current with different grounding resistance is simple to acquired based on the solution algorithm. The calculation results demonstrate that grounding resistance and structure of LVDC supply and utilization system have remarkable impacts on the transient current. The effectiveness of the proposed model is verified in PSCAD/EMTDC. The simulation results indicate that the proposed method is appropriate for the system fault analysis under various fault conditions with different grounding resistance and the proposed model can offer theoretical guidance for system fault protection.

The performance of the CdTe radiation detectors heavily relies on the method of contact preparation. A convenient research method addressing this problem is the laser-induced transient current technique. In this paper, we compare the performance of two CdTe crystals which underwent different metallization processes. We showed that appropriately designed Au/Al contacts induce much less bulk polarization than commercial Pt/In electrodes under the same working conditions and can thus provide a convenient alternative to the industry standard. The comparison was based on the monitoring of the time-dependent sensor polarization measuring transient currents excited by above-bandgap laser illumination complemented by the Am 241 gamma spectroscopy. The theoretical analysis of current waveforms and radiation spectra enabled us to determine the charge carrier mobility, mobility-lifetime products of electrons and holes, and temporal and bias dependence of the space charge formation.

The switching process of ferroelectric P(VDF-TrFE) thin films with different thicknesses is investigated through transient switching current measurements. The profile of the transient current shows a strong size effect, i.e. whether there is a peak in the transient current depends on film thickness. The different switching current profiles are attributed to a transition of switching kinetics, characterized by a unique field dependent switching time turning to a distribution of switching times in the system. Furthermore, transient current at different temperature is evaluated. The Arrhenius dependence of peak time indicates that the switching process is thermally activated. [ABSTRACT FROM AUTHOR]

• Introducing the extended transient current region by adopting short-time overcurrent capacity of grid-side converter. • Current relaxation region (CRR) is proposed for description of transient current boundary and look-up table design. • A novel CRR-based LVRT strategy is proposed to alleviate active current reduction while maintaining the reactive current ability. This paper proposes a current relation region (CRR)-based low-voltage ride-through (LVRT) strategy for offshore wind turbines (OWTs). The proposed strategy seeks to minimize the detrimental shortfall of OWT's active current on the premise of maintaining the reactive support ability by considering short-time overcurrent capacity of grid-side converter (GSC) during low-voltage fault. Firstly, the extended transient current region (ETCR) is introduced to improve the transient current ability of OWTs with comparison to conventional transient current region (CTCR) based on rated current capacity of GSC. Combined with the introduced ETCR, grid code constraint and wind speed constraint are investigated for detailed description of OWT's transient current boundary of CRR. Furthermore, we design the CRR-based LVRT strategy with look-up tables to facilitate dispatching the transient current instructions to OWTs' controllers. Finally, extensive case studies based on PSCAD are performed and the results show that the proposed strategy can improve active current and reactive current simultaneously over the conventional strategy. In the scenario of the rated wind speed (11.4 m/s) and critical voltage (0.2 p.u.), this achievement can be clearly seen by the value improvement in the active current and reactive current by 0.328 p.u. and 0.05 p.u., respectively. [ABSTRACT FROM AUTHOR]