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The high electronic conductivity and tailorable structural properties of MXene materials make them promising candidates for energy storage. However, their poor chemical instability and self‐stacking effect greatly limit their application, especially in aqueous systems. Here, using a eutectic etching approach, hydroxylated borophene is used as a trifunctional mediator to construct robust Ti3C2Tx‐based MXene/B self‐assembled film electrodes for zinc‐ion capacitors (ZICs). Due to this mediator, the as‐formed strong interfacial binding within the heterostructure can give rise to an integrated modification effect and promote high‐efficiency interface energy storage. One is to strengthen the thermodynamic stability of local Ti─O bonds and inhibit the irreversible degradation of MXene; two is to enlarge the interface space of the MXene electrode and boost the ion transport; three is to improve the interfacial Zn2+ trapping ability without affecting Zn2+ migration on the MXene surface. Thus, the MXene/B electrode exhibits a high areal capacitance (537.9 mF cm−2) at a current density of 0.2 mA cm−2 and an extraordinary cycling stability at 1 mA cm−2, with 99.64% retention after 40 000 cycles, which far surpasses that of most previous reports. This work provides a pathway for overcoming the interface storage limit of MXene electrodes to construct high‐performance ZICs. [ABSTRACT FROM AUTHOR]

This paper proposes a common mode voltage (CMV) reduction method for power full‐bridge LLC converter. A detailed derivation of asymmetrical CMV source in energy transmission (ET) and dead time resonance (DR) is presented, and a common mode (CM) equivalent circuit model considering stray parameters of power devices and transformer for the high‐voltage power LLC converter is constructed. This study assesses the influence of asymmetric junction capacitances of power devices and stray capacitances of transformer on both the CMV source and the CM model. It also examines the impact of power level on the constituent elements of the CMV source. Additionally, a theory of asymmetric CMV source cancellation is deduced based on the nonideal power LLC converter, where asymmetric noise source and coupling pathway are taken into account, which helps mitigate it through matching circuit structure without extra components. Finally, a 30 kHz 2 × 50 kW prototype is constructed and validated to reduce the CMV where the experiments show that the output CMV within high‐frequency band could be reduced by 12.15 dB at rated operating conditions. [ABSTRACT FROM AUTHOR]

In this paper, a successful electric field modulation in Lateral Double-diffused Metal Oxide Semiconductor (LDMOS) transistors to enhance the electrical characteristics is presented. A β-Ga2O3 film in the drift region is incorporated. The β-Ga2O3 film leads to a more efficient electric field modulation and enhances the DC and RF capabilities. Also, a Silicon layer is embedded in the buried oxide of the proposed structure to improve self-heating effects. Overall, the proposed β-Ga2O3 film in SOI LDMOS (βF-LDMOS) structure offers improved performances in terms of electric field distribution, maximum available power gain, unilateral power gain, gate-drain capacitance, breakdown voltage, and maximum lattice temperature. This makes it a promising candidate for RF power applications requiring high voltage and high power handling capabilities. [ABSTRACT FROM AUTHOR]

In this study, AlGaN/GaN Fin-HEMTs with different nanochannel geometric parameters were fabricated and comprehensively characterized. In the arcuate Fin-HEMTs, where the sidewalls arcuate from the source to the drain side, enhancements in the drain current density and transconductance were observed. By extracting and analyzing parameters obtained from small-signal measurements and conducting an analysis of gate capacitance, it was demonstrated that the enhancement can be attributed to the modulation of gate capacitance. This enhances the control capability of the gate over channel carriers, resulting in increased transconductance of the device. Due to the enhanced transconductance, the fT and fmax of the arcuate Fin-HEMTs are both enhanced. Notably, the arcuate Fin-HEMTs achieved a power-added efficiency of 71.4% at a frequency of 3.6 GHz and a drain voltage of 20 V. Meanwhile, the linearity of the arcuate Fin-HEMTs is improved compared with the conventional Fin-HEMTs. [ABSTRACT FROM AUTHOR]

The congenital yield reduction caused by miss-seeding in spoon-type seed-metering device of small and medium-sized potato planter is huge. Based on the physical mechanism of different measured capacitance values between two fixed capacitor plates with different media, a miss-seeding detection scheme based on a spatial capacitance sensor is proposed first. A simple and efficient spatial capacitance sensor that can obtain as large capacitance measurement value as possible is designed, and a dual CPU coordinated seed-monitoring and compensation control system architecture is adopted. AD7745 is selected for the capacitance measure of the spatial capacitance sensor, and the code of grating encoder is also recorded at the same time. Thereby, when each potato spoon passing through the space surrounded by the capacitor plates, the maximum net capacitance fluctuation and its corresponding position can be acquired. A suitable threshold can distinguish between normal-seeding and miss-seeding effectively. Moreover, it should be emphasized that, this monitoring system only requires one monitoring point. Then, based on obtained information, an improved miss-seeding catching-up compensation plan is put forward. By utilizing the powerful memory capability of the CPU, this system does not need to complete compensation immediately after the miss-seeding identification. Instead, the miss-seeding information and the location of the accident can be just marked in advance, and only when the opportunity arrives, can the miss-seeding catching-up compensation be truly executed. In this way, the position of the seed-monitoring points can be free from restriction, and the control strategy can therefore be significantly simplified. The soil tank test data showed that, the identification accuracy of the miss-seeding detection system was not less than 94%. When the seed-metering chain speeds are 0.2, 0.3, and 0.4 m/s, the average success rates of the miss-seeding compensation system are 94.32%, 83.65%, and 75.00%, respectively. The final miss-seeding rate can be below 3%, and the average deviation compensation rate was not higher than 30%, the miss-seeding was suppressed significantly. This system is a beneficial try in the non-photoelectric detection field and low complexity miss-seeding compensation for potato seeding. [ABSTRACT FROM AUTHOR]

Cobalt- and calcium-based metal–organic frameworks (Co-MOF and Ca-MOF) [Co (tpa) (Mi) and Ca (tpa)] (tpa = terephthalic acid and Mi = methyl imidazole) were synthesised through solvothermal method. Structural characterisation revealed that metal centres are equally occupied by Co2+ and Ca2+ ions. Supercapacitive behaviour of synthesised Co-MOF and Ca-MOF was evaluated using cyclic voltammetry (CV), galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS) measurements in 6 M KOH as electrolyte. The Co- and Ca-MOFs exhibited outstanding specific capacitance of 1726 and 185 Fg−1 at a discharge current density of 1 Ag−1, good rate capability, and 97.4% capacitance retention after 3000 cycles. To the best of our knowledge, Co-MOFs and Ca-MOFs are used in supercapacitor, and their encouraging properties indicate that Co-/Ca-MOF can be a promising candidate as an advanced electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

A century and a half ago, Helmholtz's model was at the forefront of development. There is no doubt that this model came into being because of the experimental data that was available at the time. Not only Helmholtz but also scientists like Nernst, Maxwell, and Pellat made their contribution to the double layer model. It is difficult to be precise about the date of origin of the Helmholtz model. Helmholtz formulated the definition of a double layer in 1853. It was in 1874 that Helmholtz pointed out the similarity between the double layer of platinum electrodes and a capacitor, but it was a capacitor with leakage (Ann. Phys. 226:483–495). Nevertheless, the 1879 article (Ann. Phys. 243:337–382) is traditionally considered the foundational work. Perhaps this opinion should be revised in favor of the 1874 work. In addition to the theoretical model, this article briefly reviews the development of experimental methods for measuring double layer capacitance: the instruments used, the equivalent circuit, and so on. The author hopes that this article will be useful in the teaching of electrochemistry. [ABSTRACT FROM AUTHOR]

Due to insufficient consideration of various factors during the dynamic evaluation of the service capacity of the electric vehicle public charging service network, the evaluation effect is poor. Therefore, the analytic hierarchy process is used to dynamically evaluate the service capacity of the network. This method first conducted an in-depth analysis of the influencing factors of charging service capacity, in order to reasonably arrange the location and quantity of charging stations. Then, considering the travel characteristics of electric vehicle users and their tendency to pursue maximum utility during the charging process, a prediction of the charging demand for charging stations was obtained. Finally, a charging service capability evaluation model was constructed using the analytic hierarchy process. By determining the weights of each evaluation indicator and combining these weights with the actual evaluation scores, the evaluation results were comprehensively calculated. The experimental results show that the proposed method performs well in terms of evaluation accuracy and evaluation duration, with a maximum evaluation accuracy of 98% and a maximum evaluation duration of only 22 s. This indicates that the method can effectively improve the accuracy of evaluation and shorten the evaluation time. [ABSTRACT FROM AUTHOR]

Discrete transmission lines constructed from ideal linear inductors and nonlinear capacitors (and possibly resistors) are studied. The localized travelling waves in the lossless transmission lines are the kinks and the solitons, the localized travelling waves in the lossy transmission lines are the dissipative kinks and the shocks. The speeds and profiles of all these waves are calculated. [ABSTRACT FROM AUTHOR]

Machine learning-based prediction of the output characteristics of a negative capacitance (NC) double gate (DG) Tunnel FET (TFET) (NC DG TFET) has been demonstrated in this paper. On current (ION), OFF current (IOFF) and sub-threshold slope (SS) have been predicted for different values of the body thickness (TSi), oxide thickness (TOX) and channel length (LCh) and the work function (WF). Random Forest Regression (RFR) model is used in the ML framework to explore the device characteristics. A total of 5444 simulated data has been generated by using the SILVACO ATLAS tool. After pre-processing the data, RFR-ML has been applied to obtain maximum accuracy. Root means square error (RMSE) (~0.34), R2 score (~0.965) and accuracy (~98.51%) parameter have been used as the figures of merit (FOM) to judge the efficiency of the proposed model with respect to the state-of-the-art literature. Besides, with higher accuracy, the model is capable of predicting the data within a few seconds compared to the few hundred hours using TCAD tools. This fast and accurate design strategy will surely be efficacious for the present VLSI industries. [ABSTRACT FROM AUTHOR]

The extraction of small‐signal parameters is of great importance for the modeling of InP heterojunction bipolar transistors (HBTs). This letter proposes an improved small‐signal parameter extraction method that considers both the emitter–collector capacitance effect and the current crowding effect. The corresponding parameter extraction procedure based on closed‐form equations is outlined. Furthermore, the model parameter extraction method is validated using two different‐sized InP HBT devices with multibias S‐parameters. The results demonstrate that the established small‐signal model exhibits greater than 90% accuracy across the frequency range of 1–110 GHz. In particular, in the high‐frequency band (above 50 GHz), the proposed model exhibits an improvement in accuracy of 7.4% after considering the emitter–collector capacitance and current crowding effects. This method can contribute to accurate modeling of the noise and large‐signal performance of InP HBT. [ABSTRACT FROM AUTHOR]

Summary: The article proposes a new DC‐link voltage balancing method for a single‐phase, five‐level DC/AC neutral point clamped (NPC) inverter. Nowadays, the NPC converter is a suitable solution for various applications; however, the unequal voltage of the DC‐link capacitors is a significant disadvantage of this topology. In this paper, a simple auxiliary unit is inserted in the DC‐link to enable a self‐balancing capacitor voltage. The auxiliary circuit is composed of two capacitors and four active switching devices. The idea of the proposed method is to construct an active DC‐link bus; thus, the two DC‐link capacitors can be connected in series during the charging process and in parallel during the discharging process. As a result, its capacitance and root mean square (RMS) current are greatly reduced. Unlike other auxiliary circuits, the new method requires no additional storage elements or complex control systems. The operating principle and switching schemes are analyzed. The effectiveness of the introduced method is evaluated experimentally using the balancing circuits under different load conditions and different value of modulation indices. [ABSTRACT FROM AUTHOR]

Summary: In the state of the art of AC‐fed light‐emitting diode (LED) drivers, power factor correction (PFC), second harmonic LED current ripple elimination, low current total harmonic distortion (iTHD), removal of electrolytic capacitors (EC) and flicker‐free operation are the major challenging issues. This paper proposes a bridgeless universal voltagerange AC‐fed LED driver that overcome the major issues of LED driver. The bridgeless buck–boost PFC configuration minimizes the losses relative to the front‐end bridge rectifier‐based configurations. Operating in discontinuous conduction mode (DCM), the source current tracks the input voltage shape for a wide operating range, achieves inherent PFC and maintains low input current THD. Also, this provides significant reduction in the output current ripple with the ripple diversion circuit (RDC) connected in shunt across the LED load, which relatively reduces and utilizes low value of output capacitance. Hence, a flicker‐free operation is achieved without the use of electrolytic capacitors. In addition, the elimination of ECs improves the operating lifespan of the proposed LED driver. A detailed theoretical analysis and results of the proposed LED driver are validated on DSP and analog controller platforms with a 62 W/62 V experimental laboratory prototype. The experimental results confirm that the proposed LED driver achieves a power factor of 0.94–0.997, input current THD of maximum 6.8%, output current ripple of 5%, and a peak efficiency of 91.25% for the wide range of input voltage variation. These indices also satisfy IEC‐61000‐3‐2 and IEEE 1789‐2015 standard limits. [ABSTRACT FROM AUTHOR]

High sensitivity and low noise of superconducting quantum interference devices make them ideal for reading the minute changes in resistance of a transition-edge sensor, which occurs when it absorbs energy or power. A series of first-order gradient, cross-coupling octagonal SQUIDs specifically tailored for use in TES were developed and fabricated for the advantage of lower parasitic capacitance compared with the overlap-coupling ones. It is obtained that a lower screening parameter and increased shunt resistance per junction lead to a higher flux-to-voltage transfer coefficient. This enhancement significantly boosts detection sensitivity and effectively minimizes noise contributions from electronics operating at room temperature. The low-temperature measurement results of the sample with an input coil of 3.5 turns indicate that a small device current white noise of 4.8 pA/√Hz, a device flux white noise of 1.1 μΦ0/√Hz, and an optimal flux-to-voltage transfer coefficient of 338.2 μV/Φ0 are achieved. The bandwidth of a SQUID current sensor with a smaller inductance of the input coil and a larger shunt resistance exceeds 10 MHz. SQUID current sensors, featuring octagonal structures with the first-order gradient cross-coupling, exhibit low flux noise, low current noise, and a high flux-to-voltage transfer coefficient, which can satisfy the requirements of TES applications. [ABSTRACT FROM AUTHOR]

The influence of frequency characteristics of devices is complex. The effects of AlN barrier thickness, gate length, gate-drain spacing and work function on the frequency characteristics of AlN/ β-Ga2O3 high electron mobility transistor (HEMT) were studied by Sentaurus TCAD in this paper. The following conclusions are obtained: as the thickness of the AlN barrier layer increases from 10 nm to 25 nm, the cutoff frequency (fT) and maximum oscillation frequency (fmax ) rise by 18 and 17 GHz respectively. The decrease of gate capacitance is the main reason for the increase of fT . Furthermore, it was found that the thinner barrier layer enhanced the gate's ability to control the channel electrons. When the gate length is scaled down from 0. 9 μm to 0. 1 μm, fT and fmax increase by 84 and 98 GHz, respectively, representing a far more profound influence on frequency characteristics than the barrier layer thickness. However, when the gate length fell below 0. 1 μm, short-channel effects emerged. As the gate-drain spacing increase, fT exhibits a slight decrease. Coupled with the concurrent reduction in source resistance, this led to a synchronized trend in fmax and fT only when the gate-source voltage (VGS ) exceeds - 1. 2 V. The work function, on the other hand, has minimal impacts on fT and fmax, but an increase in the work function positively influenced the device' s pinch-off characteristics. In summary, this paper indicates that by shortening the gate length while concurrently augmenting the thickness of the AlN barrier layer, gate-drain spacing, and work function, one can enhance the frequency characteristics while also improving the pinch-off characteristics of the device, which has certain guiding significance for the design of HEMT devices. [ABSTRACT FROM AUTHOR]

This article presents the results of a study on the feasibility of a Rigid Overhead Conductor-rail System (ROCS) for a Mass Rapid Transit (MRT) system using 750 V DC power based on a carrying capacity transport-supply voltage level relationship. In particular, peak load conditions often cause serious problems of voltage drops occurring along the contact line, affecting the reliability, flexibility, system safety, and efficiency performance of the MRT system. The potential at the pantograph of a train on the segment of power supply depends significantly on the structure of the traction power supply network, contact network type, and voltage level. Recently, there have been studies on the dynamics of ROCSs under the impact of train motion, thereby applying the design to several railway systems in the world in specific conditions such as tunnels, stations, or viaducts. To consolidate the advantages of this trend, this paper studies the operating voltage of an ROCS in a full-line MRT system with a voltage level of 750 V DC belonging to the third rail. Matlab R2017b/Railway Systems is a reliable software for simulating and analyzing the necessary data. The results exhibit the feasibility of the designed ROCS. The system has a passenger carrying capacity of up to 90,000 passengers per hour per direction (p/h/d) under both normal and fault conditions. In this case, this capacity is achieved with a single-end feed at a distance of 2 km from a Traction Power Station (TPS), with the minimum feeder voltage at the pantograph point being 532.7200 V. The lowest operational feeder voltage of the system is 523.6667 V, supplied from a double-end feed at a distance of up to 5 km from the TPS. [ABSTRACT FROM AUTHOR]

This study presents the design and comprehensive 3D multiphysics simulation of a novel microfluidic immunosensor for non-invasive, real-time detection of pro-inflammatory biomarkers in human sweat. The patch-like device integrates magnetofluidic manipulation of antibody-functionalized magnetic nanoparticles (MNPs) with direct-field capacitive sensing (DF-CS). This unique combination enhances sensitivity, reduces parasitic capacitance, and enables a more compact design compared to traditional fringing-field approaches. A comprehensive 3D multiphysics simulation of the device, performed using COMSOL Multiphysics, demonstrates its operating principle by analyzing the sensor's response to changes in the dielectric properties of the medium due to the presence of magnetic nanoparticles. The simulation reveals a sensitivity of 42.48% at 85% MNP occupancy within the detection zone, highlighting the sensor's ability to detect variations in MNP concentration, and thus indirectly infer biomarker levels, with high precision. This innovative integration of magnetofluidic manipulation and DF-CS offers a promising new paradigm for continuous, non-invasive health monitoring, with potential applications in point-of-care diagnostics, personalized medicine, and preventive healthcare. [ABSTRACT FROM AUTHOR]

Supercapacitors (SCs) have attracted great scientific interest as competitive power sources for energy storage. In this work, we aim at preparing a high-performance anode material for SCs. With the goal of designing anode material with high specific capacitance, excellent rate capability, and long-term cycling stability, we prepared high-quality Mo-doped Fe3O4 nanoparticles decorated on rGO (MFO/G) composite with unique architecture as an innovative negative electrode material for SCs through a straightforward, economical, and scalable solvothermal technique. The thin rGO nanosheets-encapsulated MFO active sites interconnect with each other, which reduces the length of the ion diffusion path between the electrolyte and electrode, leading to enhanced electrochemical performance. Significantly, the MFO/G composite exhibited a maximum specific capacitance of 807 F g−1 at a current density of 1 A g−1, along with outstanding cycle life that retaining 85.5% of its primary capacitance following 10,000 successive cycles. The results demonstrate its promising prospects as an anode material for the advancement of high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control 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 Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control 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.)

In this research, manganese cobaltite (MCO) nanoparticles with different morphologies were synthesized by a simple hydrothermal method with excellent electrochemical properties. To investigate the physical features of prepared samples, XRD analysis was used to study the crystalline structure. The SEM and TEM proved that the morphology of synthesized materials formed as flake and nanoplane structures. The electrode of samples was prepared using the hydrothermal method and the electrochemical properties of samples were investigated by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopy (EIS) and cyclic stability analysis. Results showed that the flake structures of nanoparticles revealed the highest capacitance of 1971.98 F ⋅ g − 1 at 0.5 Ag − 1 as well as longer stability compared to the others with the nanoplane structure. The high cyclic stability of 91.47% after 5000 cycles introduces this electrode as a durable and promising electrode for use in energy storage devices. [ABSTRACT FROM AUTHOR]

This article offers a novel flux controlled floating memristor emulator based on second‐generation current conveyor (CCII). The floating memristor is designed using two CCIIs, one resistor, and one PMOS transistor. The presented memristor emulator does not need external capacitance. The proposed designed circuit exhibits pinch hysteresis loops in voltage–current plane up to 2 GHz frequency. The performance of the circuit under consideration is evaluated using 180 nm CMOS technology parameter by the SPICE simulator. The circuit requires a DC power supply of ±1.2 V and exhibits a power consumption of 0.766 mW. Furthermore, the resilience of the planned circuit is assessed by examining process corner fluctuation, supply voltage variation, temperature variation, and transistor size variations. In addition, a Schmitt trigger circuit and high order filters based on designed memristor are used to confirm the operation of the proposed design at high and low frequency, respectively. [ABSTRACT FROM AUTHOR]

With the increasing penetration level of electric vehicles (EVs) in distribution networks, the limited capacity of distribution networks has become a bottleneck for EV integration. Considering the difficulties of capacity expansion in distribution networks, especially in large cities, integrating EVs with photovoltaic (PV) generation systems and battery energy storage systems has become a possible technical solution for distribution networks. However, uncertainties in the PV generation systems and EV loads make planning and operating methods difficult for such systems. This paper presents an evaluation model that simulates the uncertainties of EV and PV power generation systems using a large number of stochastic scenarios generated by the Monte Carlo method to assess the revenue of various operators under multiple possible scenarios. Multiple operation constraints were considered in the proposed method, including voltage deviations, capacity limitation of the transformer, EV owner satisfaction, and other physical constraints. In order to accelerate the evaluation process of the EVs, the Distflow equations for distribution networks were applied in the proposed evaluation model. The results of case studies indicate that the maximum capacity of EVs with different scenarios can be calculated by the proposed model. [ABSTRACT FROM AUTHOR]

An organic bulk heterojunction based on a blend of a conjugated polymer PBDB‐T‐2F (PM6) and a non‐fullerene acceptor BTP‐4F (Y6) has come forward in recent years as an archetypical system for the study of the operating principles of organic photovoltaic devices. One of the experimental techniques that has shown immense value in the study of this blend is impedance spectroscopy (IS). In spite of its relative simplicity, this method and its derivatives offer the possibility of diverse, all‐round characterization of materials and devices of interest. This Perspective summarizes recent research demonstrating the application of IS as a powerful method to obtain multifaceted information on PM6:Y6 and presents a current understanding of the experimental results. A description of general approaches employed in the processing of experimental data, including the Nyquist plots, capacitance spectra, and energy‐resolved electrochemical IS data, is supplemented by additional analysis, notably on characterization of non‐geminate recombination of free charge carriers and their transport in this groundbreaking organic blend. Finally, this work outlines the perspectives and limitations of IS in the study of future promising materials and devices. [ABSTRACT FROM AUTHOR]

A fault protection method is proposed for flexible direct-current (DC) power systems based on the cosine similarity of currents in current-limiting reactors. The typical characteristics of external and internal faults in a flexible DC power system were analyzed. The principles of cosine similarity and the fault current characteristics of current-limiting reactors were used to distinguish between internal and external faults. The ratio of the average positive and negative voltages of the current-limiting reactor was then used to distinguish the fault types and fault line. Finally, a simulation model of a circular flexible DC power system was constructed using MATLAB/Simulink software (2018b). The simulation results show that the proposed protection scheme can quickly and accurately identify the location and type of faults, and has a strong ability to withstand fault resistance and is less affected by distributed capacitance, noise, and communication delay. [ABSTRACT FROM AUTHOR]

This paper presents a complete analysis of the electrical and dielectric characteristics of N i C o 2 O 4 (NCO) bulk ceramic synthesized by the co-precipitation process as a future electronic device material. The structural analysis following the synthesis process revealed the formation of cubic-phase spinel NCO in the shape of nanospheres, with an approximate diameter of 25 nm. The present study aimed to examine the relationship between capacitance and conductance for the NCO under investigation, focusing on their frequency and temperature dependencies. The frequency range of interest ranged from 100 Hz to 1.5 MHz, while the temperature range considered was from 300 K to 450 K. The C/f plot has exhibited the phenomenon of negative capacitance, which may be attributed to the augmentation of polarization and the incorporation of additional minority carriers inside the structure. The dielectric parameters, such as permittivity, dielectric loss, alternating current conductance, and electrical modulus, were determined by capacitance and conductance measurements, taking into account their frequency and temperature reliance. All dielectric calculations were influenced by negative capacitance measurements. The negative capacitance feature of N i C o 2 O 4 is attributed to the ferroelectric properties of the Ni and Co elements in its composition. In conclusion, this paper has made a valuable contribution to the existing body of literature by enhancing our comprehension of the negative capacitance behavior and dielectric characteristics of the NCO. [Display omitted] [ABSTRACT FROM AUTHOR]

Inverters are important interfaces between micropower sources and consuming loads. However, the varying inductors and capacitors, modeling errors, measurement errors, and external disturbances would lead to degradation of the inverters' performances when conventional linear control is adopted, causing instability problems. To address it, a disturbance-rejection passivity-based nonlinear control strategy is proposed for the inverters of micropower sources. The proposed method innovatively introduces an extended high-gain state observer into the passivity-based controller to achieve online observation and elimination of complex influencing factors such as external disturbances, time-varying parameter uncertainties, and modeling errors, thus ensuring the global stability of the inverter under various disturbances. The design details on the passivity-based controller and the extended high-gain state observer are elaborated. The effectiveness and feasibility of the proposed control strategy are verified by the experiments performed by a 15 kVA inverter designed in the lab. The results show that the proposed control is able to ensure the inverter's stable operation under the following conditions: constant power load, the filter inductance and capacitance reduce up to 33% and 96%, and the input voltage varies more than 22%. [ABSTRACT FROM AUTHOR]

In this study, we examine the movement of ions that are in a water solution which flows along a duct, due to the existence of an electric field, taking into account the size of the ions, a phenomenon known as the steric effect. We compare the results from the above model with the classical one (the one that uses the Boltzmann distribution where ions are considered dimensionless) for various parameters such as surface charge density, electric field and differential capacitance. It is shown that for dilute water solutions (1019–1024 ions/m3 final concentration at the center of the duct), with ions of valence z = 1 (let us say saline water), steric effects become important for potentials greater than 1 V, and the phenomenon is more pronounced at higher concentrations. Furthermore, the steric effect model is applied to the calculation of the percentage of reduction in ion concentration in the main volume of the solution as a function of duct width for various electrode potentials and initial ion concentrations. Removal times are also calculated using Modified PNP equations which take into account steric effects. It is found that with a potential of 2.6 V, a 96% reduction in ions is achieved in the main volume of the solution for duct width 0.1 mm for 1021 ions/m3 final concentration at the center of the duct within approximately 1.6 s, while the percentage drops to 80% for duct width 1 mm. For smaller potentials, no noticeable decrease in concentration is observed, while for higher potentials, there are more impressive results, but we must be very careful because there is the case of other electrochemical phenomena taking place. The results are better when reducing the width of the duct, but relatively large widths are considered for the method to be practically applicable. With the increase in the concentration of the ions, their reduction percentage in the main volume of the solution decreases but remains significant up to 1023 ions/m3 final concentration at the center of the duct. In addition, the completion time is shown to be proportional to the duct width. Therefore, for example, with the other parameters the same (2.6 V, 1021 ions/m3) but with L ~ 1   mm , the completion time can be estimated to be approximately 16 s. This observation enables us to estimate the completion time for different duct widths, eliminating the need for repeated numerical computation of the MPNP equations. [ABSTRACT FROM AUTHOR]

Tunnel field-effect transistors (TFETs) face challenges in integrated circuit applications due to their low on current and ambipolar behavior, despite their steeper subthreshold slope. To enhance the on current and mitigate ambipolar conduction, heterojunction approaches are crucial, which ultimately improve the on to off current ratio of tunnel field effect transistors. This research presents an analytical model for heterostructure nanotube tunnel FETs. The model derives surface potential, capacitance, and drain current estimations by solving Poisson's equation, incorporating both accumulation and ionized charges. These factors are also considered in the capacitance modelling to account for the effects of n-type impurity atoms in the channel. The model accounts for the combined influence of gate and drain voltages. The performance of the proposed model is validated by comparison with simulation results from Silvaco Atlas TCAD, showing impressive agreement. [ABSTRACT FROM AUTHOR]

In this work, a new laterally double diffused metal oxide semiconductor (LDMOS) using In0.53Ga0.47As/In0.52Al0.48As Quantum well (QW) layer with a p-well step gate has been proposed. In the proposed device structure, the gate region splits into three steps in which the oxide thickness increases from the source to the drain end. As the gate insulator width varies from source to drain end, it results in better control of the gate over the channel and also a reduction in the gate-to-drain capacitance (CGD). These features offer higher transconductance with reduced switching delays, which makes the device appropriate for RF applications. Again, the concentration of current in the channel section is enhanced due to the presence of the Quantum well region and the InP spacer layer, which drastically reduces the On-resistance. But, the device achieves lesser gate-to-drain capacitance which results in decrease in the switching speed. On the other hand the proposed device offers less gate charge with the low value of CGD gives minimised switching loss. Based on 2D TCAD simulation, the proposed QW LDMOS exhibits 70% improvement in On-resistance, 45% in breakdown voltage, 84% improvement in peak transconductance, 26% improvement in switching delay, and 19% improvement in gate charge density as compared to conventional In0.53Ga0.47As devices. [ABSTRACT FROM AUTHOR]

This work presents an improved noncontact electromagnetic probe for near-field diagnosis and characterization, driven by a network vector analyzer (VNA) operating in the frequency range of 1 kHz to 1 GHz. Two configurations of a modified near-field microstrip probe (NFMP) are designed and studied, featuring a tip and a dipole termination. Simulations and experimental tests are conducted to assess the probe performances in detecting microcracks. Notably, the detection of cracks of 10 × 20 × 30 μm is achieved by leveraging the shift in resonance frequency. However, the impedance mismatch between the VNA and the probe presents a challenge to the system sensitivity. To address this limitation, a modification is proposed, introducing a surface-adjustable capacitance to the microstrip. This enhancement improves the probe sensitivity and enables full adjustability during measurements. An improvement of 27.13 dB in the reflection parameter is obtained. The developed probes provide nondestructive testing capabilities across a wide frequency range, from 1 kHz to 1 GHz, making them well-suited for integration with VNA systems and facilitating rapid and reliable external measurements. [ABSTRACT FROM AUTHOR]

MXenes have extensive applications due to their different properties determined by intrinsic structures and various functional groups. Exploring different functional groups of MXenes leads to improved performance or potential applications. In this work, we prepared new Ti3C2PBrx (x=0.4–0.6) MXene with phosphorus functional groups (−P) through a two‐step gas‐phase reaction. The acquisition of −P is achieved by replacing bromine functional groups (−Br) of Ti3C2Br2 in the phosphorus vapor. After −Br is replaced with −P, Ti3C2PBrx MXene shows an improved areal capacitance (360 mF cm−2) at 20 mV s−1 compared with Ti3C2Br2 MXene (102 mF cm−2). At a current density of 5 mA cm−2 after 10000 cycles, the capacitance retention of Ti3C2PBrx MXene has not decreased. The pseudocapacitive enhancement mechanism has been discovered based on the dual redox sites of the functional groups −P and Ti. [ABSTRACT FROM AUTHOR]

In this paper, a beta-phase gallium oxide (β -Ga2O3) vertical FinFET with diamond-gate has been studied by Silvaco-ATLAS simulation. The diamond-gate structure achieves adjustable pin (p-insulator-n) junction owing to the diamond-SiO2-Ga2O3 heterostructure. This design also enhances heat dissipation by virtue of the high thermal conductivity of the diamond. Compared to conventional FinFETs, the diamond-gate FinFET (DG-FinFET) reduces the static operating temperature rise by around 17.30%. Additionally, due to its greater heat dissipation capacity, DG-FinFETs provide a 5.84% increase in current density at 1 kA cm−2 current density level. The structural changes in the diamond-gate also result in a significant reduction in the gate-source capacitance (C GS). At 1 MHz operating frequency and the same gate voltage, DG-FinFETs have 69.29% less gate-source charge (Q GS), 70.80% less charge/discharge delay time, 73.70% less switching loss, and 57.15% less conduction loss. Overall, the simulation and analysis presented in this work indicate a promising advancement of the DG-FinFET structure in high-power and rapid switching applications. [ABSTRACT FROM AUTHOR]

The accumulation of snow is one of the essential reasons for the significant decrease in the power generation efficiency of PV stations in winter. For this reason, this paper firstly provides a detailed review of the current research into the physical processes and shedding reasons for the natural melting of snow on PV module surfaces. Then, several common techniques to promote snow and ice melting on PV surfaces are discussed, and the feasibility and shortcoming of ultrasonic technology in removing high‐density snow and ice are analyzed in detail. Finally, this paper proposes two snow sensing technologies for PV modules, namely, image processing method and interdigital capacitance method. Among them, the image method based on fixed camera and UAV detection is more suitable for wide area PV power stations, while the interdigital capacitance method is helpful in obtaining snow characteristic parameters, such as icing type and LWC. The relevant research has certain reference significance for PV power stations to formulate a more reasonable snow removal plan and power generation forecast. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Coils are designed to have impedance characteristics appropriate for any use of the sensors, analog circuits and so on. The impedance characteristics of a coil depends on the coil shape and used materials, and these factors make coil design difficult. Therefore, we proposed a convenient method to obtain the impedance characteristics of a coil by theoretical calculation of the inductance, resistance, and capacitance. The difference between the calculated and measured values was within 15%, which demonstrated the usefulness of the proposed method. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The peels of pomegranate fruits were employed in the current work to produce activated carbon (AC) using the high temperature carbonization method. The generated activated carbon using pomegranate peel (AC-PP) powder was discovered to have a layered and porous form as revealed by scanning electron microscopic images. It was discovered that activated carbon had an energy gap (Eg) of 4.454 eV. The photocatalytic experiments performed for the degradation of fast blue dye reveal that after 120 min of UV light irradiation, the AC-PP powder achieve a decolorization rate of 62.9%, respectively. Current was collected through the nickel mesh, and the electrochemical elements in rGO, the principal active component in AC-PP powder, were supported by the mesh. Nickel mesh electrodes were analysed using impedance spectroscopy and cyclic voltammetry. Both AC-PP and AC-PP-rGO electrodes' hydrogen diffusion coefficients were determined to be 1.134 10–4 and 0.0014 cm2 s−1, respectively. Experiments with galvanostatic charge–discharge revealed the produced AC-PP and AC-PP-rGO electrodes' superior capacitance potential, which is useful in the fabrication of supercapacitors. The AC-PP and AC-PP-rGO electrodes have 175.6 and 324.8 F g−1 specific capacitances. These unique impacts can also be assessed by energy storage performance using affordable carbon resources in various applications. These novel results might be used for developing up particular resources for environmental and power storage applications. [ABSTRACT FROM AUTHOR]

This paper presents a new circuit approach to realize a capacitance multiplier circuit with positive and negative multiplication factors. Based on this approach, two new implementations of positive and negative grounded capacitance multiplier (GCM) circuits are proposed, which utilize only one current follower differential input transconductance amplifier (CFDITA), in conjunction with only one resistor and one virtually grounded capacitor. The presented GCM circuits can enhance a low capacitance value to a very high value (used in low frequency applications), up to 9202 times its original value. An important aspect of the proposed circuits involves designing a lossy parallel inductor circuit by interchanging the passive elements (RC:CR transformation) with each other. The obtained value of the capacitance and inductance can be controlled independently and electronically through the transconductance of CFDITA. The practical usability of the suggested circuits as first and second order filters is discussed. The functionality of the proposed GCM circuits is validated using CMOS CFDITA implemented with 180 nm TSMC technology parameters. Experimental verification of the proposed circuits and application examples is reinforced through the utilization of CFDITA implemented with readily available ICs AD844 and LM13700. These outcomes emphasize the dependability of the suggested circuits. [ABSTRACT FROM AUTHOR]

Numerical computation of capacitance matrices using conventional finite‐difference (FD) technique for arbitrarily shaped multi‐conductor problems which typically involve thin dielectric coating is challenging due to the fact that an extremely fine discretization of the computational domain is required to capture the nuances of the geometries involved, which, in turn, exacts a high computational resource cost—both in terms of memory and time. In this paper, we present a novel finite‐difference‐based technique which utilizes polynomial interpolation and extrapolation techniques in conjunction with the conventional finite‐difference technique to handle 2‐dimensional problems involving multiple conductors, typically with a thin dielectric coating. The proposed technique does not require fine discretization of the computational domain and provides accurate results in an efficient manner. [ABSTRACT FROM AUTHOR]

[Display omitted] The behavior of cucurbit[6]uril at the electrode/solution interface in the presence of magnesium sulfate was investigated and quantified. It has been established that at the highest positive potential available for the adsorption of organic compounds, a structure is formed that consists entirely of neutral cavitand molecules. [ABSTRACT FROM AUTHOR]

As the precursor of 2D i -MXene, i -MAX phase appeals lots of exertions on the improvement of its chemical diversity, among which alloying is an effective strategy. Herein, we report on the synthesis of the M-alloyed i -MAX phase (Mo 0.75 M 0.25) 4/3 Er 2/3 GaC (M = Ti, V, Nb, Ta, W). Structure analysis identifies all of them as Cmcm orthorhombic. The corresponding M-alloyed i -MXene, (Mo 0.75 M 0.25) 1.33 CT z (M = Ti, V, Nb, Ta, W), was synthesized by HF etching and shows potential as an electrode for supercapacitors due to its improved charge storage performance and cyclic stability. A volumetric capacitance of 431.7 F g−1 was delivered at the scan rate of 2 mV s−1 for (Mo 0 · 75 V 0.25) 1.33 CT z , and a 94.8% capacitance was retained after 10,000 charge/discharge cycles for (Mo 0 · 75 W 0.25) 1.33 CT z. Modelling was performed to better understand the mechanism improving the electrochemical capacitance and to clarify the i-MXene alloying process. The alloying strategy shows a novel and simple way to control i-MXene's surface termination, which will make it facilitate to use in applications like high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

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Energy density, the Achilles' heel of aqueous supercapacitors, is simultaneously determined by the voltage window and specific capacitance of the carbon materials, but the strategy of synchronously boosting them has rarely been reported. Herein, we demonstrate that the rational utilization of the interaction between redox mediators (RMs) and carbon electrode materials, especially those with rich intrinsic defects, contributes to extended potential windows and more stored charges concurrently. Using 4‐hydroxy‐2,2,6,6‐tetramethylpiperidinyloxyl (4OH‐TEMPO) and intrinsic defect‐rich carbons as the RMs and electrode materials, respectively, the potential window and capacitance are increased by 67% and sixfold in a neutral electrolyte. Moreover, this strategy could also be applied to alkaline and acid electrolytes. The first‐principle calculation and experimental results demonstrate that the strong interaction between 4OH‐TEMPO and defect‐rich carbons plays a key role as preferential adsorbed RMs may largely prohibit the contact of free water molecules with the electrode materials to terminate the water splitting at elevated potentials. For the RMs offering weaker interaction with the electrode materials, the water splitting still proceeds with a thus sole increase of the stored charges. The results discovered in this work could provide an alternative solution to address the low energy density of aqueous supercapacitors. [ABSTRACT FROM AUTHOR]

Boosting the charge‐transport pathways in gel–polymer electrolytes (GPEs) is important to extract their full potential for non‐Faradaic, supercapacitive energy‐storage devices. Herein, a series of polyoxometalates (POMs) ([P6W18O79]20−, [PW9O34]9− and [PW12O40]3−) as electrochemical polarization promoters is demonstrated to achieve 15‐fold enhancement in ionic conductivity of 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide‐based GPEs. Fundamentally, the three POMs offer systematically differing charge densities (200, 45, and 6.5 e− nm−3) that are linearly correlated to the observed enhancements in ionic conductivities. The charge density on the POMs contributes to the formation of additional charge‐migrative pathways across the GPE, as evidenced from facile polarization characteristics. Importantly, the presence of POM beyond a critical concentration acts as charge‐trapping centers to impede the ionic conductivity of the GPEs. The insights obtained through such detailed spectroscopic and electrochemical techniques are integrated into full‐scale supercapacitive devices with a rationally designed porous hard carbon as the electrode material. The resulting electrode–electrolyte interface synergies achieve a best‐in‐class supercapacitor exhibiting energy density of 58 Wh kg−1, power density of 14 kW kg−1, and a relaxation time constant of 0.66 s, without compromising on cycling stability for direct integration with intermittent energy‐harvesting devices. Thus, the fundamental insights presented here outline the design principles for extracting high‐performance from GPE‐based energy‐storage devices. [ABSTRACT FROM AUTHOR]

A silicon carbide (SiC) SGT MOSFET featuring a "一"-shaped P+ shielding region (PSR), named SPDT-MOS, is proposed in this article. The improved PSR is introduced as a replacement for the source trench to enhance the forward performance of the device. Its improvement consists of two parts. One is to optimize the electric field distribution of the device, and the other is to expand the current conduction path. Based on the improved PSR and grounded split gate (SG), the device remarkably improves the conduction characteristics, gate oxide reliability, and frequency response. Moreover, the integrated sidewall Schottky barrier diode (SBD) prevents the inherent body diode from being activated and improves the reverse recovery characteristics. As a result, the gate-drain capacitance, gate charge, and reverse recovery charge (Qrr) of the SPDT-MOS are 81.2%, 41.2%, and 90.71% lower than those of the DTMOS, respectively. Compared to the double shielding (DS-MOS), the SPDT-MOS exhibits a 20% reduction in on-resistance and an 8.1% increase in breakdown voltage. [ABSTRACT FROM AUTHOR]

Conventional dry electrodes often yield unstable results due to the presence of parasitic capacitance between the flat electrode surface and the non-uniform skin interface. To address this issue, a gel is typically placed between the electrodes to minimize parasitic capacitance. However, this approach has the drawbacks of being unsuitable for repeated use, limited lifetime due to gel evaporation, and the possibility of developing skin irritation. This is particularly problematic in underserved areas since, due to the cost of disposable wet electrodes, they often sterilize and reuse dry electrodes. In this study, we propose a method to neutralize the effects of parasitic capacitance by attaching high-value capacitors to the electrodes in parallel, specifically when applied to pulse wave monitoring through bioimpedance. Skin capacitance can also be mitigated due to the serial connection, enabling stable reception of arterial pulse signals through bioimpedance circuits. A high-frequency structure simulator (HFSS) was first used to simulate the capacitance when injection currents flow into the arteries through the bioimpedance circuits. We also used the simulation to investigate the effects of add-on capacitors. Lastly, we conducted preliminary comparative analyses between wet electrodes and dry electrodes in vivo with added capacitance values ranging from 100 pF to 1 μF, altering capacitance magnitudes by factors of 100. As a result, we obtained a signal-to-noise ratio (SNR) that was 8.2 dB higher than that of dry electrodes. Performance was also shown to be comparable to wet electrodes, with a reduction of only 0.4 dB using 1 μF. The comparative results demonstrate that the addition of capacitors to the electrodes has the potential to allow for performance similar to that of wet electrodes for bioimpedance pulse rate monitoring and could potentially be used for other applications of dry electrodes. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs), as high‐potential electrode materials for applications in supercapacitors, have received significant attention recently. Unfortunately, MOF materials still suffer from unsatisfactory specific capacitances due to poor conductivity and limited redox active sites. Herein, a novel cobalt–copper‐based bimetal–organic framework (CoCu‐MOF) is synthesized by a bottom‐up synthesis strategy, the material properties systematically characterized, and finally investigated as a supercapacitor electrode material. The synthesized CoCu‐MOF presents a high specific surface area of 62.4 m2 g−1, and 83% of the copper ions attains the +1 oxidation state contributing to the formation of additional redox active sites and leading to the formation of dual‐redox sites. The CoCu‐MOF displays an excellent specific capacitance of 618 F g−1 at a current density of 1 A g−1, which is more than twice that of Co‐MOF and four times that of Cu‐MOF. The CoCu‐MOF retains 75% of its original capacitance after 3000 charge–discharge cycles at the current density of 1 A g−1. Overall, this work demonstrates how the bimetallic synergistic strategy can effectively enhance the electrochemical properties of MOFs by providing a higher specific surface area and by the introduction of dual redox sites. [ABSTRACT FROM AUTHOR]

It is of great scientific and economic value to recycle waste poly (ethylene terephthalate) (PET) into high-value PET-based metal organic frameworks (MOFs) and further convert it into porous carbon for green energy storage applications. In the present study, a facile and costeffective hydrothermal process was developed to direct recycle waste PET bottles into MIL-53(Al) with a 100% conversation, then the MOFderived porous carbon was assembled into electrodes for high-performance supercapacitors. The results indicated that the as-synthesized carbon exhibited high SSA of 1712 m2 g-1 and unique accordion-like structure with hierarchical porosity. Benefit to these advantageous characters, the assembled three-electrode supercapacitor displayed high specific capacitances of 391 F g-1 at the current density of 0.5 A g-1 and good rate capability of 73.6% capacitance retention at 20 A g-1 in 6 mol L-1 KOH electrolyte. Furthermore, the assembled zinc ion capacitor still revealed outstanding capacitance of 335 F g-1 at 0.1 A g-1, excellent cycling stability of 92.2% capacitance retention after 10 000 cycles and ultra-high energy density of 150.3 Wh kg-1 at power density of 90 W kg-1 in 3 mol L-1 ZnSO4 electrolyte. It is believed that the current work provides a facile and effective strategy to recycle PET waste into high-valuable MOF, and further expands the applications of MOF-derived carbons for high-performance energy storage devices, so it is conducive to both pollution alleviation and sustainable economic development. [ABSTRACT FROM AUTHOR]

Direct-current (DC) power converters play an indispensable and crucial role in various systems, particularly in today's increasing electrification of global energy. The characteristics of DC power converters have garnered widespread attention in the design and practical application of energy-saving systems. General system design not only considers the output voltage and power rating of DC power converters but also factors such features as efficiency, input voltage regulation, output load regulation, dynamic load regulation, and ripple voltage characteristics as specified in the manufacturer's datasheet. The objective is to provide a stable power supply to ensure the regular operation of the system. However, the characteristics of maximum startup capacitance are often overlooked, and sometimes only numerical values from the datasheet are used as reference, limiting the insight into the startup characteristics curve. The improper assessment of the startup capacitance characteristics may lead to power startup failure or repetitive oscillations, thereby affecting the operational stability of the system. In this study, the in-depth examination of four high-power-density DC power converters is investigated. Firstly, foundational characteristics testing research is conducted. The characteristics of the maximum startup capacitance are examined in this study by constructing and analyzing the experimental environment. In this research, we explain the critical points in constructing the environment for maximum capacitor load testing and compare the differences between passive components for load and electronic load machine simulation experiments. Finally, we complete the experiment in a low-cost detection environment constructed with essential passive components and obtain the maximum capacitor load characteristic curves of the high-power-density DC power converters. This information will become a reference for system design, ensuring the stability assessment of DC power converters under maximum capacitor load conditions. Additionally, sensor integration for real-time performance monitoring further enhances the understanding of startup capacitance dynamics in high-power-density DC power converters. [ABSTRACT FROM AUTHOR]

The work focuses on vertical cavity surface emitting lasers (VCSELs) made of nitride materials that emit a wavelength of 445 nm. Two structures were examined: a laser with a tunnel junction and implantation (TJ VCSEL) and an ITO contact (ITO VCSEL). The analysis delves into capacitance phenomena influencing the modulation speed of these lasers. The results highlight differences in active currents between two structures, i.e., currents which contribute to the modulation of the laser emission. According to the authors' simulations, the TJ VCSEL is more effective in modulating the number of carriers in the active region than the ITO VCSEL, assuming the same modulation amplitude of driving current. [ABSTRACT FROM AUTHOR]