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We have studied charging effect in a lateral split gate quantum dot defined by metal gates in the two dimensional electron gas of a GaAs structure. The gate structures allows an independent control of conductance's of the two tunnel barriers separating the quantum dot from the two dimensional leads, and enable us to vary number of m[ that are located in the dot. We have measured coulomb blockade oscillations in the conductance as the function of gate voltage. Figures 1 - 3 are the results of the study. The conductance at high temperature is constant and at low temperature show oscillation both in positive and negative gate voltage. The current is carried by successive discrete charging and discharging of the dot, form single charge tunnelling. [ABSTRACT FROM AUTHOR]

There is an urgent need to develop a robust capacitor charge power supply (CCPS) system to meet the requirement of pulsed load in all‐weather mobile occasions such as vehicle, ship and aircraft. Brushless doubly fed alternator (BDFA) works through the rotor's pole pairs' transformation to get excitation indirectly, without magnets, brushes and slip rings. Both DC and AC excitation can be used. Therefore, it has high reliability and a good application prospect in the CCPS system. However, the existing research studies lack analysis of the parameters that affect charging performance, and have no experimental analysis of the prototype. To solve this problem, a comprehensive design method and experimental procedure of the pulsed BDFA are proposed and investigated. First, the operation principle of the pulsed BDFA is illustrated. Then, the charging performances under different design schemes are comparatively analysed through the finite element analysis (FEA). Finally, a prototype of the pulsed BDFA is manufactured, and the related experiments are carried out. The results verify the feasibility of the experimental procedure and the accuracy of FEA. The comprehensive design method and experimental procedure in this work provide a straightforward reference for the subsequent applications in the CCPS system. [ABSTRACT FROM AUTHOR]

To find out the law of charging effects of high-energy electrons in artificial radiation belt produced by a high-altitude nuclear explosion (HANE) on the dielectric materials, we present a simulation model of high-energy electrons in artificial radiation belt contributing to internal charging of dielectric material, which are commonly used inside the satellites or spacecraft. The deposition electric parameters such as injection current density, charge deposition rate, and radiation dose rate are obtained by using the Monte Carlo simulation method. The equations of charging electric field of Teflon material have been presented and numerically solved. The distributions of electric field and potential in the dielectric material Teflon charged by artificial radiation belt and the change rules with charging time have been obtained. The results show that the peak charging electric field produced by artificial radiation belt in dielectric material is lower than that produced by 1-MeV single-energy electron under the same injection current density. When the artificial radiation belt generated by the HANE with a yield of 5 kt charges the Teflon material with a thickness of 4 mm, the time needed for charging to reach saturation will be more than 24 h, and the saturated charging electric field can reach 106 V/m, so the discharge risk is low. For artificial radiation belt generated by the HANE with a yield 1.4 Mt, when the time to start charging is within 100 days after the explosion and the charging duration is within 1 h, the maximum charging electric field in Teflon material will exceed 107 V/m and the discharge risk will be high. [ABSTRACT FROM AUTHOR]

Measurement of electron energy spectra of dielectrics is a challenge due to charging issues. This article presents experimental results of electron energy spectra of dielectric materials under electron irradiation obtained by transforming the charging process into a spectroscopic tool. The technique was verified on conductive materials in a previous paper. This method is based on capturing the charging transient of the secondary electron emission current. Dielectric materials are irradiated with a single train of pulses of monoenergetic electrons. The evolution of the number of emitted electrons as a function of time is measured. The rate of this evolution coupled to the arising potential on the surface of the material conveys the energy at which the secondary electrons are emitted. The total incident dose used in this method is about 10 pC/mm2, in contrast to the high doses required when other common methods are utilized. The use of low doses ensures a minimal distortion of the pristine state of the dielectric material by avoiding radiation damage, deep charging, defects, aging and other electron induced phenomena in the insulator. This method was applied to obtain the secondary electron energy spectra of the Kapton, Teflon, and Ultem polymers.

Numerical modeling is applied to elucidate the formation mechanism of the large lower positive charge centers (LPCCs) observed during thunderstorms over the Tibetan Plateau based on the simulation of a storm at the northeastern boundary of the plateau. Four sensitivity tests were carried out to explore the impacts of inductive charging, reversal temperature, and the choice of noninductive charging scheme. The results show that the unique environmental conditions of the Qinghai‐Tibet Plateau, which include weak convection and low freezing level, are fundamental to the formation of large LPCC. A weakened charge density in the upper positive charge center highlights the role of a LPCC in lightning initiation although the charge density of the LPCC has no obvious change compared to that in the LPCC of the typical tripole structure. This accounts for Tibetan Plateau thunderstorms having low frequencies of lightning flashes, which occur mainly in the lower dipole. Inductive electrification, which provided more than 50% of the positive charge on graupel and increased the positive and negative charge on cloud drops by 2 orders of magnitude, is an important complement to the lower dipole of the tripole charge structure originally established by noninductive electrification. The inductive electrification also evidently enhances the LPCC and the middle negative charge center while slightly reducing the upper positive charge center. Subsequently, the lightning activity is strengthened, and lightning flashes are more likely to be initiated at the lower dipole. Varying the reversal temperatures and noninductive charging scheme does not fundamentally affect the formation of the LPCC. Key Points: Low freezing level and weak convection in the Tibetan Plateau appear to be the root cause of the formation of the large LPCCInductive charging is an important complement to the lower dipole of the tripole charge structure; its impact is assessed quantitativelyWeak updraft is the key to produce the similar characteristics between Tibetan Plateau thunderstorms and Japanese winter storms [ABSTRACT FROM AUTHOR]

Charging effects of dielectric due to space electron beam irradiation have a huge impact on spacecraft. To understand charging equilibrium characteristics of dielectric under electron beam irradiation, in this paper, we present a novel numerical simulation method for analyzing the secondary electron yield (SEY) based on a charging balance mode. We used the Mott scattering model and the Penn dielectric function (PDF) model to calculate the collisions between incident electrons and material the atoms of material. For internal charge transport, we considered the processes of drift, diffusion, trapping, and neutralization. These were calculated with a finite-difference time-domain (FDTD) method. Based on mechanisms of import–export dynamic charge evolution, charging balance can be categorized into three modes: SE mode, leakage (LE) mode, and cooperation (CO) mode (a combination of the two). In most situations, the SE mode corresponds to the surface charging state, while the LE mode always corresponds to deep charging states. Shortening the distance of free charge transport, a thinner sample is more likely to present as LE mode. Although the surface potential can be enhanced by monotonously increasing the thickness, the total internal charge quantity approaches a local maximum with thickness because of a charging balance mode transformation. In addition, with a larger average density of carriers in the LE mode, the material conductivity is enhanced and the dielectric loss tends to be larger at low frequencies (<103 Hz). The charging balance mode method in this study can also be appropriate to the analyses of altering irradiation parameters and materials intrinsic parameters. [ABSTRACT FROM AUTHOR]

During the bombardment of insulator materials with high-energy particles, the samples are often emitting light and are sparking. This fact makes both the ion-beam analysis and the ion implantation of insulating materials more difficult. Light may disturb the detectors, sparks usually disturb the current-integration systems and electronics. Moreover, the accumulation of positive charges alters the results of the experiments via decelerating the incoming ions and accelerating the outgoing particles. In case of ion implantation, the projected range may be changed, while in ion-beam analysis the shape of the spectra can be changed resulting evaluation problems. To avoid the charge accumulation several methods have been used in the daily practice such as applying thin cover layers, wrapping or masking the samples, applying relatively low beam currents or electron sources in the experimental chamber. A short review of the above mentioned methods to avoid the charge accumulation is given. Moreover, the evaluation problems of the spectra taken on sparking (or at least charged-up) samples are also discussed. Proton and helium backscattering spectrometry as well as elastic recoil detection analysis are used to demonstrate the capability of a simple model of charge accumulation which is implemented to DEPTH code. [ABSTRACT FROM AUTHOR]

Highlights • It is unique to use the flexibility provided by electrical vehicle to optimize power-traffic system operation. • A hierarchical operation approach is designed to shave the peak and smooth the ramp for both systems. • The electrical vehicles and charging/discharging stations are used to couple the power-traffic system. • The distributed algorithm is designed to reduce the computation time. Abstract The power distribution system and urban transportation system are two networked system bare their own operation constraints, such peak load in power systems and traffic congestion in transportation system. With the increasing number of electrical vehicles and charging/discharging stations, two systems are become tightly coupled. However, to optimize the two systems target using electrical vehicles as decision control variables cannot be easily solved using a uniformed optimization frame work. Thus we propose a hierarchical optimization approach to address this problem, which consists of a higher and a lower level. In the higher level, the power distribution system and urban transportation system are treated together to minimize the social cost. Meanwhile, the electrical vehicles and the charging/discharging stations are treated as customers to minimize their own expenditures. Then, an equilibrium is designed to determine the optimal charging/discharging price. In the lower level, the models of power distribution system and urban transportation system are developed to provide a detailed analysis. Specifically, in power distribution system, the three-phase unbalanced optimal power flow problem is relaxed with the semidefinite relaxation programming, and solved with alternating direction method of multiplier. A dynamic user equilibrium problem is formulated for the urban transportation system. For electrical vehicles, the state of charge is considered to optimize the charging/discharging schedule and reduce the impacts of power distribution systems. We conducted the simulation and numerical analysis using the IEEE 8500-bus distribution system and the Sioux Falls system with about 10,000 cars. The results demonstrate the feasibility and effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

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Discharge rate is a key parameter affecting the cycle life of lithium-ion batteries (LIB). Normally, lithium-ion batteries deteriorate more severely at a higher discharge rate. In this paper, we report that the cycle performance of LiNi0.8Co0.15Al0.05O2/graphite high-energy 2.8 Ah 18650 cells is abnormally worse at a 1.5 C discharge rate than at a 2.0 C discharge rate. Combining macromethods with micromethods, the capacity/rate performance, electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) morphology of the electrodes are systematically investigated. We have found that the impedance of the negative electrodes after 2.0 C aged is smaller than that after 1.5 C aged, through EIS analysis, and the discharge rate performance of the negative electrodes after 2.0 C aged is better than that after 1.5 C aged through coin cell analysis. In addition, some special microcracks in the negative electrodes of aged cells are observed through SEM analysis, which can accelerate the side reaction between active and electrolyte and form the thicker SEI which will hinder the Li+ insertion and cause resistance increase. In short, the LiNi0.8Co0.15Al0.05O2/graphite-based lithium-ion batteries show better cycle life at a 2.0 C discharge rate than at a 1.5 C discharge rate which indicates that the negative electrodes contribute more than the positive electrodes. [ABSTRACT FROM AUTHOR]

Catenary-free trams with an onboard supercapacitor have been an emerging and energy-efficient way for urban rail transportation. However, the high-power charging load from catenary-free trams brings a new challenge to the design of charging systems. The traditional single-module charging system typically suffers from a high power and thermal pressure, which reduces the reliability of the charging system. In this paper, we propose a multimodule charging system to improve the system reliability by decomposing power pressure to multiple charging modules. Specifically, a cooperative charging protocol is proposed to improve the dynamic performance of the charging system by suppressing the current imbalance and avoiding the current overshoot during the startup process. First, we mathematically model the multimodule charging system using the state-space averaging method and graph theory. Second, the cooperative charging protocol is designed using the leader–follower consensus algorithm, where the virtual leader represents the desired charging current for each module with a warm-start mechanism. Third, multiple-input multiple-output root locus technique is exploited to characterize the dynamic performance of the charging system. Both simulation and experiment results show that the proposed protocol effectively suppresses the imbalance and avoids the overshoot during the startup of the charging system. [ABSTRACT FROM AUTHOR]

Plug-in electric vehicles are the currently favoured option to decarbonize the passenger car sector. However, a decarbonisation is only possible with electricity from renewable energies and plug-in electric vehicles might cause peak loads if they started to charge at the same time. Both these issues could be solved with coordinated load shifting (demand response). Previous studies analyzed this research question by focusing on private vehicles with domestic and work charging infrastructure. This study additionally includes the important early adopter group of commercial fleet vehicles and reflects the impact of domestic, commercial, work and public charging. For this purpose, two models are combined. In a comparison of three scenarios, we find that charging of commercial vehicles does not inflict evening load peaks in the same magnitude as purely domestic charging of private cars does. Also for private cars, charging at work occurs during the day and may reduce the necessity of load shifting while public charging plays a less important role in total charging demand as well as load shifting potential. Nonetheless, demand response reduces the system load by about 2.2 GW or 2.8% when domestic and work charging are considered compared to a scenario with only domestic charging. [ABSTRACT FROM AUTHOR]

SUMMARY: Spacecraft need high‐voltage power generation for high power. However, the high voltage can cause severe discharge problem on spacecraft. This paper describes the mechanism of spacecraft charging and discharging. Mitigation methods are also mentioned. [ABSTRACT FROM AUTHOR]

Secondary electron emission has an important role on the triggering of the multipactor effect; therefore, its study and characterization are essential in radio-frequency waveguide applications. In this paper, we propose a theoretical model, based on equivalent circuit models, to properly understand charging and discharging processes that occur in dielectric samples under electron irradiation for secondary electron emission characterization. Experimental results obtained for Pt, Si, GaS, and Teflon samples are presented to verify the accuracy of the proposed model. Good agreement between theory and experiments has been found. [ABSTRACT FROM AUTHOR]

Abstract: In pursuing higher energy density, without compromising the power density of supercapacitor platforms, the application of an advanced 2D nanomaterial is utilized to maximize performance. Antimonene, for the first time, is characterized as a material for applications in energy storage, being applied as an electrode material as the basis of a supercapacitor. Antimonene is shown to significantly improve the energy storage capabilities of a carbon electrode in both cyclic voltammetry and galvanostatic charging. Antimonene demonstrates remarkable performance with a capacitance of 1578 F g−1, with a high charging current density of 14 A g−1. Hence, antimonene is shown to be a highly promising material for energy storage applications. The system also demonstrates a highly competitive energy and power densities of 20 mW h kg−1 and 4.8 kW kg−1, respectively. In addition to the excellent charge storing abilities, antimonene shows good cycling capabilities. [ABSTRACT FROM AUTHOR]

This paper proposes a design procedure which optimizes the electrical parameters involved in the Inductively Coupled Power Transfer (ICPT) system and correlates them with geometrical dimensions of the charging coils involved for charging of electric vehicles. The Inductively Coupled Power Transfer (ICPT) system makes it possible to charge the Electric Vehicles (EVs) wirelessly at some distance to avoid safety issues and to provide convenience to the users. The ICPT system has potential applications in the field of medical sciences, office appliances, industrial loading machines, and battery charging applications. Although the ICPT system has been successful for the charging of the electric vehicles, but it retains some challenges, prominently limitation of misalignment tolerance and low efficiency of the overall circuit. The methodology presented in this paper helps in choosing appropriate dimension of the coils and electrical parameters to cope with the issue of misalignment tolerance. A program based on the mathematical model has been developed in Matlab software to determine optimal values of overall ICPT system circuit parameters and the geometrical dimensions of coils. The experiments of the ICPT system have been carried out with developed optimal coil design for 1 kW power transfer at various air gaps. The misalignment tolerance of the ICPT system has been recorded and presented in the paper. The proposed optimal design achieves maximum efficiency of 90.5% at perfect alignment, however, it maintains the efficiency of 72% at 35–40% misalignment between the coils. The misalignment test results support the design of coils for EV charging application. [ABSTRACT FROM AUTHOR]

Wireless power transfer (WPT) system usually suffers from wide range of coupling condition. This causes deep impact on the transferred power level, which further limits the mobility of receiver. In this paper, a dual-side-detuned series–series (SS) compensation method is proposed to provide stable power transfer over wide geometric area. The primary and secondary tuning methods are classified into three categories, respectively, namely fully tuned, inductively tuned, and capacitively tuned. Then, the general power transfer characteristic against coupling factor is identified and it is found that the primary inductively and secondary capacitively tuned (PISC) system is advantageous over other candidates in performance, especially the resistance to variation of coupling factor. Compared to conventional fully tuned SS system, the PISC-type WPT system provides much wider stable power transfer region, which enables higher mobility for the receiver side. The design consideration and principle of the detuned resonant tank is developed, based on which the iteration approach is proposed to guide parameter design procedure. Finally, the validity of the proposed dual-side-detuned SS topology is experimentally verified. Under coupling variation from 0.08 to 0.2, the power transfer is maintained above 80% of its nominal power level with agreeable efficiency. [ABSTRACT FROM PUBLISHER]

Besides the photochromism isomerization, scientists are likely to focus more and more on the influence on the electrochemical reduction conditions of the azobenzene isomerization process. Diverse azobenzene compounds were chosen to study the behavior of their trans and cis isomers upon electrochemical reduction. Hence, thermal reaction mechanisms for the neutral, cationic and anionic azobenzene derivatives isomerization with a wide variety of electron-donating and electron-withdrawing groups in the para-position of the benzene ring in ground state have been systematically examined applying the density functional theory method. Some prominent changes in structure, energy barrier and reaction rate arose from charge changes of azobenzenes have been detected and interpreted in terms of the strengths of substituents, the polarity of solvents and charge effect. Our findings indicate that the radical anion of the cis isomer can isomerize to the corresponding trans configured counterpart rapidly with a tremendously enhanced rate and obvious decreased energy barriers with respect to the neutral species as the distribution of the electron density changed, signifying that the metastable isomer of a photoswitch is able to isomerize to the more stable one catalytically upon reduction and the charge effect has obvious influence on the reaction mechanism. [ABSTRACT FROM AUTHOR]

MgO thin film has a high secondary electron emission coefficient. However, the accumulation of electric charge on the surface of the thin film will inhibit it. This paper mainly discusses this phenomenon with the method of reactive magnetron sputtering. We prepared a MgO/Au buffer layer by co-sputtering Au in the inner layer of MgO. The experiments show that Au distributes mainly in the gap of the MgO grains. Adding appropriate Au will promote the growth of MgO grains in the longitudinal direction, increase the conductivity of the material, suppress the accumulation of electric charge on the surface, and increase the secondary electron emission coefficient of the thin film. NiO was also used as the transition layer of MgO and substrate in the experiments, so as to increase the adhesion of the MgO films and improve the quality of the thin film. According to the experiment results, the maximum secondary electron emission coefficient of MgOAu multilayer composite film increased by 28.9% compared with that of the pure MgO film. Under the continuous irradiation of 200 eV incoming energy, the decay rate decreased from 35.2% to 30.6% in 1 h. [ABSTRACT FROM AUTHOR]

Ion-ion interactions in supercapacitor (SC) electrolytes are considered to have significant influence over the charging process and therefore the overall performance of the SC system. Current strategies used to weaken ionic interactions can enhance the power of SCs, but consequently, the energy density will decrease due to the increased distance between adjacent electrolyte ions at the electrode surface. Herein, we report on the simultaneous enhancement of the power and energy densities of a SC using an ionic mixture electrolyte with different types of ionic interactions. Two types of cations with stronger ionic interactions can be packed in a denser arrangement in mesopores to increase the capacitance, whereas only cations with weaker ionic interactions are allowed to enter micropores without sacrificing the power density. This unique selective charging behavior in different confined porous structure was investigated by solid-state nuclear magnetic resonance experiments and further confirmed theoretically by both density functional theory and molecular dynamics simulations. Our results offer a distinct insight into pairing ionic mixture electrolytes with materials with confined porous characteristics and further propose that it is possible to control the charging process resulting in comprehensive enhancements in SC performance. [ABSTRACT FROM AUTHOR]

Images of Ga+-implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga+ density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast. [ABSTRACT FROM AUTHOR]

The charging state of aerosols in an 8 m 3 reaction chamber was measured using an electrostatic classifier with a condensation particle counter at different levels of ionization in the chamber. By replacing the Kr-85 neutralizer in the classifier with a radioactively neutral dummy we were able to measure only the aerosols that were charged inside our reaction chamber. These measurements were then compared with measurements using the neutralizer to get the charging state of the aerosols, which refers to the charged fraction of the aerosols compared to an equilibrium charge distribution. Charging states were measured for both positively and negatively charged aerosols while the ionization in the chamber was varied using external gamma sources. We find that the negatively charged aerosols were overcharged (relative to the equilibrium) by up to about a factor of 10 below 10 nm and at 16 ± 2 % from 10 to 70 nm. At higher levels of radiation on the chamber the smaller aerosols were less overcharged while the large aerosols were more overcharged ( 23 ± 2 % ). For the positively charged aerosols only the smallest aerosols were overcharged while those over 10 nm were undercharged (relative to the equilibrium) by 21 ± 3 % . Increasing the radiation on the chamber increased the undercharge above 10 nm to 25 ± 2 % while the overcharge below 10 nm disappeared. The split between positive and negative charges above 10 nm can be explained by differences in mobility of small negative and positive ions. The overcharge below 10 nm can be explained by ions participating in the formation of aerosols of both signs, while the reduction in this overcharge at higher levels of ionization may be explained by faster recombination. [ABSTRACT FROM AUTHOR]

Deep dielectric charging/discharging is a serious space environmental effect. Charging electric fields are the fundamental cause of dielectric discharging. In order to quantitatively mitigate deep dielectric charging effects, the GEANT4 toolkit and radiation-induced conductivity model were used to calculate the maximum possible internal charging potential and electric field with different shielding layer thicknesses, dielectric thicknesses, and ground types. The study selected electron spectra from geostationary earth orbit (GEO) and jupiter orbits as the input environment. With these calculations, a criterion for shielding, dielectric thickness, and ground types is provided such that spacecraft engineers may choose the appropriate method to decrease the deep dielectric charging effects. The charging time constants of flame retardant 4 and polytetrafluoroethylene are ~20 and 500 h, respectively, with a little dependence on input electron spectra, ground type, shield thickness, or dielectric thickness. The dielectric characteristics, ground types, and thicknesses, which can significantly change the value of the electric field, are critical for preventing deep dielectric charging. The maximum saturation charging potential and electric field at jupiter orbit are much larger than those at GEO. [ABSTRACT FROM PUBLISHER]

A novel method is developed to study the charging of a conducting surface covered by a thin dust layer in plasma. The potential profile in the dust layer and the floating potential of the surface underneath are measured directly by embedding conducting wires in the dust and connecting the wires to a measurement plate outside the vacuum chamber, where a Trek non-contacting electrostatic voltmeter measures the floating potential of the measurement plate. Laboratory experiments are carried out to study plasma charging of a conducting plate covered by lunar dust simulant, JSC-1A. The results show that the plate potential is dependent on both the ambient plasma condition and the dust layer thickness. The current balance condition controls the floating potential of the dust surface while the dust layer acts as a capacitor and controls the potential of the plate with respect to the dust surface. Hence, a dust covered conducting plate will be charged more negatively than a clean plate. [ABSTRACT FROM AUTHOR]

The charging time-consuming and lifespan of lithium-ion batteries have always been the bottleneck for the tremendous application of electric vehicles. In this paper, cycle life tests are conducted to reveal the influence of different charging current rates and cut-off voltages on the aging mechanism of batteries. The long-term effects of charging current rates and cut-off voltages on capacity degradation and resistance increase are compared. The results show that there exists a critical charging current and a critical charging cut-off voltage. When the charging stress exceeds the critical value, battery degradation speed will be greatly accelerated. Furthermore, battery aging mechanisms at various charging currents and cut-off voltages are investigated using incremental capacity analysis. It is indicated that charging current and cut-off voltage should be reduced to retard battery degradation when the battery degrades to a certain extent. The time when the loss of electrode material accelerates is taken as the crisis to reduce charging current and the time when the loss of lithium inventory accelerates is taken as the crisis to reduce charging cut-off voltage. Moreover, an experiential model quantitatively describing the relationship between capacity degradation rate and charging stresses at different aging states is established. [ABSTRACT FROM AUTHOR]

A liquid vapor deposition (LVD) method, in which vapor from a liquid silicon precursor, cyclopentasilane (CPS), is utilized, allows homogeneous incorporation of silicon into mesopores of monodispersed starburst carbon spheres (MSCS). The amount of silicon incorporated can be precisely controlled just by changing the amount of CPS. MSCS consists of carbon nanorods and their surfaces are shown to be coated with silicon. The Si/MSCS is tested for an anode of LIB. It is found to retain a capacity of more than 2000 mAh/g after 100 charging cycles when an appropriate amount of silicon is incorporated into MSCS. [ABSTRACT FROM AUTHOR]

This work presents a systematic evaluation of the effect of dissimilar charging / discharging temperatures on the long-term performance of lithium iron phosphate / graphite based cells by using multi-factor analysis of variance. Specifically, the degradation of prototype pouch cells is presented in a range of charging and discharging temperatures from -20 °C to +30 °C, counting a total of 10 temperature combinations. In this manner, not only the effect of charging and discharging temperatures was analyzed, but also the correlations between them. Fitting of the data showed a quadratic relationship of degradation rate with charging temperature, a linear relationship with discharging temperature and a correlation between charging and discharging temperature. Cycling at the charge/discharge temperatures (+30 °C, -5 °C) produced the highest degradation rate, whereas cycling in the range from -20 °C to +15 °C, in various charge/discharge temperature combinations, created almost no degradation. It was also found that when Tc≅ 15 °C the degradation rate is independent of Td . When Tc < +15 °C, the higher degradation occurs at higher Td and at Tc > +15 °C lower degradation occurs at higher Td . [ABSTRACT FROM AUTHOR]

This study addresses two problems in the context of battery electric vehicles (EVs) for intercity trips: the EV routing problem and the EV optimal charging station location problem (CSLP). The paper shows that EV routing on the shortest path subject to range feasibility for one origin–destination (O–D) pair, called the shortest walk problem (SWP), as well as a stronger version of the problem – thep-stop limited SWP – can be reduced to solving the shortest path problem on an auxiliary network. The paper then addresses optimal CSLPs in which EVs are range feasible with and withoutp-stops. We formulate the models as mixed-integer multi-commodity flow problems on the same auxiliary network without path and relay pattern enumeration. Benders decomposition is used to propose an exact solution approach. Numerical experiments are conducted using the Indiana state network. [ABSTRACT FROM AUTHOR]

Physical-model guided design on transistor test structures aiming for extracting backend metal charging design rules is demonstrated for the first time. Based on experimental data from a six-metal-layer technology, the demonstration shows such design methodology to be feasible. The methodology enables adequate design for the test structures from which a complete set of metal charging design rules can be extracted for a given process technology. This paper concludes that a significant reduction in the number of the required test structures and accordingly a large saving for test chip layout space during process development can be realized with the new design methodology. The number of the design-rule-extraction test structures could be reduced by a half for a six-metal-layer technology and by 77% for a thirteen-metal-layer layer technology, with a minimum number as low as four per transistor type, gate oxide thickness, and gate protection option if such methodology is adopted. The advantage inherited in the new methodology is delineated. [ABSTRACT FROM PUBLISHER]

Amorphous InHfZnO (a-IHZO) thin-film devices have attracted considerable attention owing to their high mobility. However, the mobility of a-IHZO thin-film transistors has not been correctly determined, because it is affected by fast charging. In this letter, we investigated the effect of transient charging on the mobility. On the basis of the pulse \textI\mathrm {DS} – \textV\mathrm {GS} method, we present an approach to estimate a correction factor for the measured apparent mobility, which was extracted from pulse amplitude versus threshold voltage shift. [ABSTRACT FROM PUBLISHER]

Ferroelectrets are non-polar polymer foams or polymer systems with internally charged cavities. They are charged through a series of dielectric barrier discharges (DBDs) that are caused by the electrical breakdown of the gas inside the cavities. Thus, the breakdown strength of the gas strongly influences the charging process of ferroelectrets. A gas with a lower breakdown strength has a lower threshold voltage, thus decreasing the onset voltage for DBD charging. However, a lower threshold voltage also leads to a lower value for the remanent polarization, as back discharges that are caused by the electric field of the internally deposited charges can take place already at lower charge levels. On this basis, a charging strategy is proposed where the DBDs start in a gas with a lower breakdown strength (in the present example, helium) and are completed at a higher breakdown strength (e.g., nitrogen or atmospheric air). Thus, the exchange of the gas in the cavities during charging can significantly enhance the charging efficiency, i.e., yield much higher piezoelectric coefficients in ferroelectrets at significantly lower charging voltages. [ABSTRACT FROM AUTHOR]

We report on the progress made during the initial stage of our research to study charging rate and charge distribution in a thin walled dielectric wakefield accelerator (DWA) from a passing charge bunch and the physics of conductivity and discharge phenomena in dielectric materials useful in accelerator applications. The issue is the role played by the beam halo and intense wakefields in charging the dielectric, possibly leading to undesired deflection of charge bunches and degradation of the dielectric material: the effects that may grow over many pulses, albeit perhaps differently at different repetition rates. During the initial stage of development, a microwave apparatus was built and signal processing was developed to observe time-dependent charging of dielectric surfaces and/or plasmas located on or near the inner surface of a thin-wall hollow dielectric tube. Three frequencies were employed to improve the data handling rate and the signal-to-noise. The test and performance results for a plasma test case are presented; in particular, the performance of the test unit shows capability to detect small changes ~0.1% of a dielectric constant, which would correspond to the scraping-off of only 0.3 nC to the walls of the dielectric liner inside the cavity from the passing charge bunch. [ABSTRACT FROM AUTHOR]

We propose a novel approach for monitoring the wafer-level plasma-induced charging effect in advanced CMOS fin-shaped field effect transistor (FinFET) processes, and successfully demonstrate that ON-chip charge collectors, consisting of antenna-coupled floating gates (FGs), can record the plasma charging levels during back-end-of-the-line processes. The charge stored on these in situ recorders helps to project the actual potential on the transistor gates during plasma-charging stress. Wafer maps containing the potential distribution, as estimated by the level of positive and negative charging effects on the FGs, provide a powerful tool for future FinFET process optimization and yield additional insights for device reliability analysis. [ABSTRACT FROM PUBLISHER]

Fluctuation of wind turbine output power is one the most important drawbacks of these kinds of resources. This oscillation caused by wind speed variation is undesirable for the microgrid to which the wind turbine is connected. Therefore, reduction of output power oscillation of wind turbines is one of the most important issues related to this resource. In this paper, a new method based on Continuous Wind Speed Forecasting (CWSF) is proposed to reduce fluctuation. Output power fluctuation reduction is considered as momentary in transient power oscillations and performed using short term wind speed forecasting. The goal of this paper is to decrease the output power fluctuation of a set of wind turbines and their energy storage system by CWSF and Online Supervisory Control. The oscillation reduction is performed in both the charging and discharging modes of the ultra-capacitor. The studied wind turbine is a 50kW wind turbine and all simulations are implemented in MATLAB SIMULINK. [ABSTRACT FROM AUTHOR]

A two-dimensional cloud model with electrification and lightning processes is used to investigate the role of inductive charge separation in thunderstorm clouds. For the same dynamic and microphysical evolution, four cases that the same noninductive charging parameterization is combined with different inductive charging process are compared. Non-inductive charge separation alone is found to be sufficient to produce a dipolar charge structure. Intracloud (IC) and positive cloud-toground (+CG) flashes are initiated between a main negative charge region and an upper positive charge region. The inductive charging process between graupel and cloud droplets exhibits a normal tripole charge structure, consisting of a lower positive charge region under the main negative charge region. In the simulated tripole structure, negative cloud-to-ground (-CG) flashes are initiated between the main negative and lower positive charge regions. In addition, inductive charge separation between the graupel and ice crystal is found to be capable of producing strong charge separation in a dipole charge structure. Tests with inductive graupel-ice crystals process produce more flashes than that in the other cases. [ABSTRACT FROM AUTHOR]

Dust charging in an unmagnetized collisionless dusty plasma with two-temperature electrons was investigated based on the orbital motion limited theory, where the two-temperature electrons and ions are modelled by the Maxwellian distributions. Then by taking into account the effects of two-temperature electron and the associated charging fluctuations, the dispersion peculiarities of dust-acoustic waves are studied based on dust fluid dynamics. The present results show that the effect will introduce a dissipation on the mode, and the dispersion and the dissipation depend on the temperature ratio and number density ratio of hot and cold electrons. [ABSTRACT FROM AUTHOR]

Pharmaceutical powders are very prone to electrostatic charging by colliding and sliding contacts. In pharmaceutical formulation processes, particle charging is often a nuisance and can cause problems in the manufacture of products, such as affecting powder flow, fill, and dose uniformity. For a fundamental understanding of the powder triboelectrification, it is essential to study charge transfer under well-defined conditions. Hence, all experiments in the present study were conducted in a V-blender located inside a glove box with a controlled humidity of 20%. To understand tribocharging, different contact surfaces, namely aluminum, Teflon, poly methyl methacrylate, and nylon were used along with 2 pharmaceutical excipients and 2 drug substances. For the pharmaceutical materials, the work function values were estimated using MOPAC, a semiempirical molecular orbital package which has been previously used for the solid-state studies and molecular structure predictions. For a mechanistic understanding of tribocharging, a discrete element model incorporating charge transfer and electrostatic forces was developed. An effort was made to correlate tribocharging of pharmaceutical powders to properties such as cohesive energy density and surface energy. The multiscale model used is restricted as it considers only spherical particles with smooth surfaces. It should be used judiciously for other experimental assemblies because it does not represent a full validation of a tightly integrated model. [ABSTRACT FROM AUTHOR]

This paper presents a double-layer smart charging management algorithm (SCMA) for electric vehicles in working place parking lots considering smart grid concept. This model enables safe and controlled charging, which satisfies both power grid and drivers’ needs comprehensively. First level of SCMA controls each transformer power demand, transformer capacity, charging station status and the shortest way to reach suitable charger. Second level of SCMA is used during the charging process in order to provide cost-effective and reliable charging as well as less impact on power grid. The proposed SCMA strategy successfully routes the electric vehicles (EVs) to the most suitable charging point, decreases the charging costs and prevents the overloading of transformers. In this study, a comparison regarding the impacts of the whole charging process of the EVs on the power grid and drivers’ requests with/without the proposed SCMA is presented and the results are discussed in detail. [ABSTRACT FROM AUTHOR]