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Abstract This study extensively investigated the ageing characteristics and lifetime model of oil–paper insulation for oil‐immersed paper condenser bushing. The accelerated thermal and electrothermal ageing experiments of oil‐immersed paper condenser bushing were conducted respectively. The properties of oil–paper insulation during the ageing process were investigated. Results showed that descending speed of degree of polymerization of the innermost and the outermost layer paper was higher than that of middle layer paper, the difference in water content on different paper layers caused varying deterioration speeds. The aluminium foil contributed to a surge in aluminium dissolution in oil, further accelerating the ageing of insulation. Based on the obtained degree of polymerization data under thermal ageing at 90°C, 100°C and 130°C, the lifetime model of oil–paper insulation for condenser bushing model was established. In addition, the surface breakdown of the scale model of bushing occurred after 133 days ageing, the properties of bushing decreased gradually during the ageing process and sharply after the breakdown. Degree of polymerization deviation of different paper layers in bushing between calculated value according to the above lifetime model and actual value of bushing after the breakdown was less than 6%, further verifying the validity of lifetime model.

In recent years, electrophoretic display (EPD) attracts great attention for its ultra‐low power consumption, which is suitable for self‐powered applications. In this case, an energy storage system, simple as the capacitor, is essential for the self‐powered driving of EPDs. However, significance on the capacitor‐based driving of EPDs was underestimated in spite of its great practical value. This paper investigated the capacitor‐based driving of EPD for better performances of self‐powered EPDs. Based on this novel scheme, sports shoes with self‐powered EPD patterns were demonstrated as the future wearable applications. [ABSTRACT FROM AUTHOR]

This paper describes a flow control of the dye in the paper mill with the quasi-Z-source indirect matrix converter (QZSIMC) fed induction motor drive. More than a decade the voltage-source inverter (VSI) and current-source inverter (CSI) have been used to control the speed of the induction motor, which in turns controls the flow of dye. Recently, the matrix converter (MC) has been an excellent competitor for the VSI or CSI for its compactness. The voltage transfer ratio of the VSI, CSI, and MC has been limited to 0.866. Thus, the efficiency of these converters is less. To improve the voltage transfer ratio the quasi-Z-source network (QZSN) is to be used between voltage source and indirect MC (IMC). The modification in the shoot-through duty ratio of the QZSN varies the voltage transfer ratio greater than 0.866. Different voltage transfer ratios are needed for different voltage sag conditions. For a variation of the duty ratio of the QZSN, the fuzzy logic controller has been presented. To control the IMC vector control with space vector modulation has been presented. This paper proposes the implementation of QZSIMC adjustable speed drive for the flow control of dye in paper mill during different voltage sag conditions. A 4-kW prototype has been built and the effectiveness of the proposed system is verified with simulation results and experimental setup. Simulation is done in MATLAB, Simulink platform. Experimental setup is done with the aid of a TMS320F2812 (Texas Instrument) processor. The experimental results validate the maintenance of the speed of an induction motor at the set condition, thus controlling the perfect flow of dye in paper manufacturing technology. [ABSTRACT FROM AUTHOR]

Vertical, organic, light‐emitting transistors (VOLETs) combine three of the four essential components of an active matrix lightemitting diode (AMOLED) pixel ‐ the drive transistor, the storage capacitor, and the OLED stack ‐ into a single, highly‐stable, selfemissive structure. VOLETs can be manufactured on amorphous silicon (a‐Si) thin‐film transistor (TFT) backplanes to enable lowcost AMOLED displays with improved brightness and lifetime characteristics. We report on the current status of VOLET development and prospective impact on the active‐matrix display industry. [ABSTRACT FROM AUTHOR]

Lengthened ion pathway in porous carbon cathode, especially under high mass loading and packing state, severely impeded the ion transport, thus leading to a far unsatisfactory energy/power out of Zn//C capacitors. Here, we report a novel kapok-derived quasi-2D thin-walled porous carbon tile (CT) with proper curvature and rich doping used as stacked bricks. Together with high conductivity single-walled carbon nanotubes, a porous yet relatively packed self-standing carbon cathode was constructed, which features a hierarchical ion path including short ion pathways inside thin-walled porous CTs and adequate channels "highways" caused by rational sub-micron interlayer spacing, thus leading to an excellent combination of rate and gravimetric/volumetric/areal performance at practical mass loading (12 mg cm−2). [Display omitted] • A porous thin-walled layered carbon tile with proper curvature was prepared as bricks. • Porous yet packed cathode feathers hierarchical paths for fast ion/charge transfer. • High rate and gravimetric/volumetric capacity remain in high loading cathode. • The areal capacity increases linearly with the mass loading of cathode. Long ion pathway inside large-sized carbon particle or stacked 2D assembly greatly limit the electrochemical performance of practical carbon cathode (>10 mg cm−2) in Zn//C capacitors. Highly porous activated carbon and holy graphene can alleviate such ion-transport issue, but usually suffer from a far lower packing density and severe restacking, respectively. Herein, a kapok-derived quasi-2D thin-walled microporous carbon tile (CT) with optimized curvature and rich doping was developed and used as bricks. Assisted with single-walled carbon nanotubes (SWNTs), a porous yet relatively packed paper cathode was constructed. The unique doped thin wall (∼700 nm) can effectively shorten the ion-penetration pathways from electrolyte deep into pore structure inside CTs, and thus enlarge ion-accessible surface areas. Combined with rational sub-micron interlayer spacing among proper-curved CTs and bridged-like SWNTs, the continuous ion/charge transport "highways" are fabricated. As a result, such self-standing carbon cathode delivers outstanding rate and gravimetric/areal performance (114 mAh g−1/1.37 mAh cm−2) without sacrificing volumetric capacity even at high mass loading (12 mg cm−2). [ABSTRACT FROM AUTHOR]

[Display omitted] • Aramid-based energy storage capacitor was synthesized by a convenient method. • Electrical breakdown strength was optimized by the interface engineering. • Good dielectric constant thermal stability from RT to 300 °C was achieved. • Our finds promoted the energy storage capacitors in commercial use. Polymer-based dielectric energy storage capacitors show more potential than conventional rigidity ceramic-based capacitors. Recent studies were classified into two categories: the excellent room temperature performance in poly (vinylidene fluoride) (PVDF) systems and the enhanced thermal stability in polyimide-based systems. Only now, however, both of them are still far from commercial use because of their inferior heat resistance or poor processability. By adding BaTiO 3 (BT) particles in maturely used aramid nanofibers, we synthesized the aramid nanofiber (ANF)/BT-based flexible paper capacitors through a convenient industrialized technology in this work. Due to the intrinsic laminated structure of ANF and the uniform distribution of BT particles, the composite film with BT addition of 8 vol% exhibits outstanding dielectric thermal stability. With the help of the interfacial resistance in the organic–inorganic interface, which protected the ANF matrix from being breakdown too early by optimizing the electrical field distribution, a high and stable energy storage density of 6.70 J/cm3 was obtained in ANF/BT5. In addition, excellent energy storage frequency stability with ultrafast discharge speed was also achieved. This work offered a highly repeatable way to synthesize commercially used flexible capacitors, bridging the lab investigation and commercial use in high-power density energy storage polymers. [ABSTRACT FROM AUTHOR]

Copyright of Electrical Engineering & Electromechanics is the property of National Technical University, Kharkiv Polytechnic Institute 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.)

To effectively improve the power density and rate capability of layered double hydroxide (LDH) based supercapacitors, a hybrid supercapacitor (HSC) comprising of hierarchical ultrathin NiAl-LDH nanosheet arrays on carbon nanotube paper (CNP-LDH) is developed with porous graphene nanosheets as the negative electrode for the first time. SEM image shows that hierarchical NiAl LDH nanosheet arrays are assembled by numerous ultrathin nanosheets with thickness of a few to tens of nanometers. Remarkably, with an operating voltage of 1.6 V, the HSC possesses a high energy density of 50.0 Wh kg −1 at an average power density of 467 W kg −1 . Even at a fast discharging time of 3.9 s, a high energy density (23.3 Wh kg −1 ) could also be retained at a power density of 21.5 kW kg −1 . Moreover, the HSC exhibits cycling stability with a retention rate of 78% after 5000-cycle charge-discharge test at 5 A g −1 . The results inspire us to propose our high-performance CNP-LDH as a promising electrode for energy storage applications. [ABSTRACT FROM AUTHOR]

Supercapacitors have drawn numerous attentions in recent years since they can deliver relatively high power and energy densities. This article introduces an all-printed paper based surface mountable supercapacitor (SMS), which could withstand the reflow soldering process when integrated into microelectronic systems. The device was fabricated by screen printing and stencil printing processes, contributing to low cost and large-scale fabrication. Furthermore, building electronic devices on ubiquitous paper substrates had advantages of light weight, low cost, and eco-friendliness, etc. Based on activated carbon electrode material and ionic liquid electrolyte, the capacity of the supercapacitor could reach 14 mF at the device volume of 3.2 mm ? 2.5 mm ? 0.175 mm, besides, the specific volumetric capacity was superior than most of the commercial SMS devices. [ABSTRACT FROM PUBLISHER]

Graphite, an allotrope of carbon, is also a moderately good conductor of electricity. The shading pencil lead consists of graphite mixed with clay and, therefore, can conduct electricity, allowing one to construct and demonstrate different properties and the underlying concepts of circuit elements. The grade displayed on the pencil relates to the graphite-to-clay ratio, with higher B grades indicating a higher graphite-to-clay ratio. In this paper, the main objective is to show the dependence of resistance and capacitors on different physical parameters and to calculate the value of π electrically. The materials used in this activity are readily available, affordable, and suitable for demonstration purposes. The materials used to perform these activities are shading pencils of different grades, A-4 size papers, crocodile clips, and an LCR meter. [ABSTRACT FROM AUTHOR]

In this study, the multifunctionality of structural dielectric capacitor made by integrating graphene oxide paper into carbon fibre reinforced composite has been investigated. The study is based on an earlier work on the use of graphene oxide for dielectric material in the structural dielectric capacitor, in which electrical properties have been characterized. In this work, an in-depth study on electrical and mechanical properties of this kind of structural dielectric capacitor have been carried out. In addition, the multifunctional efficiency of structural dielectric capacitors were evaluated and compared with existing structural dielectric capacitors. Through experiments, it is revealed that both electrical and mechanical properties of the structural dielectric capacitors were significantly enhanced by interleaving a graphene oxide paper in the middle of composite. Therefore, the multifunctional efficiency of this kind of structural dielectric capacitors has been ultimately improved, indicating the excellent potential of graphene oxide paper in the development of multifunctional materials for energy storage, potentially for high-strength required applications, such as electric vehicles and unmanned aerial vehicles. [ABSTRACT FROM AUTHOR]

The necessity of drying the graphene oxide suspension (GOsus) using Hummer's Method to produce graphene oxide (GO) powder was studied. The undried GOsus was compared to the dried GO. The GO materials were used as Pt supports via NaBH4 reduction for O2 reduction. XRD patterns showed similar d-spacing in both while the half-cell tests of the Pt/rGOsus and Pt/rGO catalysts were similar. GOsus film, deposited onto Toray Carbon Paper and electrochemically reduced in aq. H2SO4 was tested as a capacitor. The suspension and dried graphene-based capacitor showed similar XRD and XPS patterns and the erGOsus capacitor displayed increased capacitance. [ABSTRACT FROM AUTHOR]

Electronic capacitors were constructed via hand-printing on paper using pencil graphite. Graphite traces were used to draw conductive connections and capacitor plates on opposing sides of a sheet of standard notebook paper. The paper served as the dielectric separating the plates. Capacitance of the devices was generally < 1000 pF and scaled with surface area of the plate electrodes. By combining a pencil-drawn capacitor with an additional resistive pencil trace, an RC low-pass filter was demonstrated. Further utility of the pencil-on-paper devices was demonstrated through description of a capacitive force transducer and reversible chemical sensing. The latter was achieved for water vapor when the hygroscopic cellulose matrix of the paper capacitor’s dielectric adsorbed water. The construction and demonstration of pencil-on-paper capacitive elements broadens the scope of paper-based electronic circuits while allowing new opportunities in the rapidly expanding field of paper-based sensors. [ABSTRACT FROM AUTHOR]

The identification and quantification of chemicals play a vital role in evaluation and surveillance of environmental health and safety. However, current techniques usually depend on costly equipment, professional staff, and/or essential infrastructure, limiting their accessibility. In this work, we develop paper-based capacitive sensors (PCSs) that allow simple, rapid identification and quantification of various chemicals from microliter size samples with the aid of a handheld multimeter. PCSs are low-cost parallel-plate capacitors (~$0.01 per sensor) assembled from layers of aluminum foil and filter paper via double-sided tape. The developed PCSs can identify different kinds of fluids ( e.g. , organic chemicals) and quantify diverse concentrations of substances ( e.g. , heavy metal ions) based on differences in dielectric properties, including capacitance, frequency spectrum, and dielectric loss tangent. The PCS-based method enables chemical identification and quantification to take place much cheaply, simply, and quickly at the point-of-care (POC), holding great promise for environmental monitoring in resource-limited settings. [ABSTRACT FROM AUTHOR]

A capacitor formed of fluid-impregnated paper metalized on one side and a polymer film results in a relaxation peak caused by the much more rapid polarization of the dielectric fluid impregnated paper relative to the polymer film. This results in the capacitance being a function of frequency, with a substantial increase in capacitance at very low frequencies. A theory for such a capacitor is developed and compared with measurements on actual capacitors with relatively good agreement. The implications of the theory for discharge current and discharge efficiency are discussed. [ABSTRACT FROM AUTHOR]

In this paper, we designed a novel multicolor electrochromic (EC) device having hybrid capacitor electrochromic device based on 4,4 '‐biphenyl dicarboxylic acid diethyl ester and phenothiazine molecule with carbon electrode. The EC properties of the device were analyzed and discussed for the possibility to multicolor representation. [ABSTRACT FROM AUTHOR]

This paper presents a 14‐Gb/s dual mode receiver with MIPI D‐PHY and C‐PHY interfaces for mobile display drivers. To reduce size overhead from the dual mode interfaces, we propose the termination circuit that can share 50‐Ω terminations and common‐mode capacitors while maintaining a perfectly matched load balance. The proposed dual mode receiver supports up to 14 Gb/s total bandwidth in each interface mode, resulting in broad compatibility with application processors. A mobile display driver using the proposed dual mode receiver is fabricated in a 28‐nm high‐voltage CMOS process and verified up to 3.5 Gb/s per lane in the D‐PHY mode and 2.2‐Gs/s per lane in the C‐PHY. [ABSTRACT FROM AUTHOR]

Measurements of capacitors made with paper sheets reveal a significant decrease in capacitance with increasing frequency from 10 to 100,000 Hz, offering a simple demonstration of complex dielectric phenomena using common equipment. [ABSTRACT FROM AUTHOR]

Power capacitors are highly reliable due to their completely enclosed configuration. They are relatively trouble-free over the long term. However, their dielectric strength can be reduced due to some stresses, including overvoltage application or thermal degradation of the insulation material during long periods of operation; these events can result in dielectric breakdown of capacitors in extreme cases. Since almost all power capacitors with oil-impregnated paper have been operated for more than twenty years, some kind of failure should be expected. To prevent these incipient accidents, it is important to examine the insulation deterioration mechanism and evaluate the degree of deterioration before capacitor breakdown. To establish a diagnostic method of deterioration of the capacitors with oil-impregnated paper, we have conducted thermally and electrically accelerated deterioration tests and investigated the changes of their characteristics. Based on the experimental results we obtained, it can be concluded that the behavior of the oil-dissolved gases can be used as a useful index to diagnose the insulator deterioration of these capacitors. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a flexible and freestanding carbon nanofiber/graphene nanosheet (CNF/GNS) composite paper is prepared via electrospinning followed by high-temperature annealing using a polyacrylonitrile/GNS/dimethylformamide mixture as electrospun precursor. The structure characterizations show that GNS homogeneously distributes in the CNF, forming a thin, light-weight and flexible composite paper. Due to the reinforcing effects coming from CNF and GNS, the Brunauer Emmett Teller (BET) specific surface area, conductivity and capacitance performance of pure CNF are significantly improved after adding GNS. The GNS/CNF composite paper exhibits the largest specific capacitance of 197Fg−1, about 24% higher than that of pure CNF paper. Therefore, based on the above investigations, such GNS/CNF composite paper can be a potential candidate for high-performance flexible capacitors. [Copyright &y& Elsevier]

In order to improve the efficiency of ruthenium dioxide, RuO2, as an electrochemical capacitor electrode, a RuO2 thin film is deposited on carbon paper and its structure and properties are evaluated. This new composite material is prepared via solution dip-coating of a Ru-ethoxide precursor and heat conversion. The coating thickness is easily controlled by varying the number of repetitions of the preparation process. The resulting structure consists of a by homogeneously coated RuO2 film on carbon paper which has a porous graphite matrix. Extensive electrochemical studies have been performed in 1 M H2SO4 electrolyte in order to evaluate the properties of the composite as an electrode in an electrochemical capacitor. The composite material shows not only high specific capacitance (620 F g−1) but also good power characteristics. [Copyright &y& Elsevier]

This paper describes a new vacuum thermal recycling (VTR) method for treating discarded polychlorinated biphenyls (PCB)-contaminated capacitors and pressure-sensitive paper. Based on results demonstrating an exceptionally high PCB separation efficiency and recovery ratio from capacitors containing high-concentration PCBs, i.e. > 99.9%, respectively, the presented VTR method is verified to effectively remove PCBs. In addition, associated safety aspects of the employed procedure were confirmed. [Copyright &y& Elsevier]

Bandpass filters are integral in modern communication systems for selecting specific frequency ranges to ensure interferencefree signal transmission and reception. This paper explores various bandpass filter designs, including those using active inductors, transmission-line unit-cells, microstrip open-loop resonators, and dual-port dual-frequency integration antennas. The focus is on the 10.7-MHz bandpass filter, widely used in FM radio and television systems. The study evaluates current-controlled and balanced designs, analyzing their performance, advantages, and drawbacks. Unique trade-offs in terms of linearity, distortion, temperature sensitivity, and component variations are discussed. Additionally, advancements in filter technology and diverse design options are presented. The paper introduces a novel current-balanced, frequency-adjusted bandpass filter to address odd-order noise issues. This filter aims to achieve high linearity, harmonic distortion attenuation, and the elimination of even-order harmonics. Through synthesis, analysis, simulation, and comparison with traditional filters, the proposed design enhances signal quality and efficiency. The fullybalanced current-tunable bandpass filter with the Caprio technique at 10.7 MHz is developed, exhibiting symmetrical characteristics with lower total harmonic distortion. The circuit’s structure is simple and adaptable for integration, validated through consistent simulation results. The study concludes by emphasizing the constant sensitivity of transistor differential amplifier circuits to the center frequency and the linear relationship between center frequency and adjustable bias current. The suggested transistor and capacitor selection criteria contribute to optimizing the circuit’s performance, aligning with the Caprio technique’s recommendations. Overall, this research presents a promising solution for achieving high-quality signal transmission in contemporary communication systems. [ABSTRACT FROM AUTHOR]

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

Abstract: A nanostructured Ni(OH)2 electrode was prepared and evaluated in supercapacitor application. Mesoporous Ni(OH)2 tubes were integrated onto carbon fiber paper without the use of a binder. The large surface area and porous structure of Ni(OH)2 combined with the effective diffusion of electrolytes through carbon network resulted in an excellent charge storage capacity and good long-term cyclability. [Copyright &y& Elsevier]

The letter presents the design, fabrication, and measurement of a configurable radio frequency identification (RFID) tag based on time-domain reflections. The tag circuit contains a microstrip line (ML) that propagates radio frequency (RF) signals, and a group of capacitors that introduce impedance discontinuities to encode binary codes. The configurability of the tag circuit is allowed by connecting the nearby-placed capacitors with the ML. Ink-jet printing technology is employed to implement the layout of the proposed tag on paper substrate. To overcome the limitations of printed metallic tracks, a linearly tapering technique is proposed. With this technique, a four-bit configurable passive chipless RFID tag is realized. Both time-domain reflectometry (TDR) measurements and ultrawideband (UWB) characterizations were conducted for the proposed tag, and the results are in good consistence with the simulation ones from the circuit simulator advanced design system (ADS). Owing to its low cost fabrication and environmentally friendly nature, the proposed tag has great potential to be widely employed in low-end RFID applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2781-2786, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26412 [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to better design the resonant tank parameters for LLC resonant converter. And, it is found that under heavy load, the voltage gain is affected by junction capacitors of the primary side switching and the parasitic parameters of the secondary side diodes converted to the primary side, which will cause the voltage gain decreased when the switching frequency decreased. Design/methodology/approach: This paper proposes an optimization parameters design method to solve this problem, which was based on impedance model considering the parasitic parameters of switching devices and diodes. Findings: The effectiveness of the proposed method is verified by impedance Bode plots and experimental results. Originality/value: From the perspective of impedance modeling, this paper finds the reasons for the insufficient voltage regulation capability of LLC resonant converters under heavy load and finds solutions through analysis. [ABSTRACT FROM AUTHOR]

Copper (Cu) based pastes have emerged as the termination materials of choice for ceramic capacitors with base metal internal electrodes. To prevent oxidation of nickel (Ni) internal electrode and the copper terminations, it is necessary to fire the terminations in a nitrogen atmosphere. This requirement places significant restrictions on raw material selection for the termination pastes. For example, acrylic-based resins are used as organic binder for their clean burning characteristics over the traditional ethyl cellulose based binder system. As the viscoelastic behavior of acrylic resin systems are different to those of cellulose systems, differences are observed in the flow behavior of the paste. In this paper, the influence of paste rheology on the green cosmetic defects such as mooning, peaking, etc. is discussed. Additionally, the influence of process condition such as dipping parameters, drying conditions etc., on the green cosmetic defects are discussed. Finally, properties of a copper termination, which can be processed between 800-825 °C, are discussed. [ABSTRACT FROM AUTHOR]

Presents a study that examined the aging process of mineral oil-impregnated-high density kraft paper capacitor bushing models subjected to voltage switching surges. Effects of the removal of electrical impulse stress over a finite time period; Thickness of the insulating system of the model capacitor bushing; Implication of the partial discharged inception stress characteristics for the doubled insulation specimen.

The work reported in this paper aims at developing an algorithm for system operators to solve a robust security-constrained AC optimal power flow (R-SC-ACOPF) problem, which also optimizes the settings of discrete controllers including load tap changers (LTCs) and shunt capacitor banks (SCBs). An iterative algorithm involving a master problem and a number of sub-problems is proposed. The master problem selects the optimal discrete controllers’ settings by taking into account primal SC-ACOPF constraints based on the single-component worst contingencies identified by the sub-problems. Each sub-problem is a bi-level max-min problem used to find the current worst contingency. The overall objective is to minimize the total cost, including generation and load shedding cost, while satisfying all relevant constraints. The master problem and sub-problems allow representing LTC tap positions, SCB status, and contingencies using binary variables. Two case studies are presented as applications of this novel technique. [ABSTRACT FROM AUTHOR]

This paper proposes a novel method to generate a SWEEP signal line‐by‐line for PWM driving microLED pixel circuit. The proposed method generates a SWEEP signal based on the linearly increasing voltage of the capacitor by flowing a constant current to the horizontal line parasitic capacitive load. The constant current is supplied by the sweep generation (SG) circuit in each line. Since the SG circuit utilizes the existing SCAN signals for the pixel circuit, additional SCAN or clock signals are not required. By using the proposed method, an individual SWEEP signal for each line can be generated without a significant increase in operational complexity in the display panel. [ABSTRACT FROM AUTHOR]

Germination paper (GP) is used as a growth substrate in plant development studies. Current studies bear two limitations: (1) The actual GP water content and variations in GP water content are neglected. (2) Existing irrigation methods either maintain the GP water content at fully sufficient or at a constant deficit. Variation of the intensity of water deficit over time for plants grown on GP is not directly achievable using these methods. In this contribution, a new measurement and control approach was presented. As a first step, a more precise measurement of water content was realized by employing the discharging process of capacitors to determine the electrical resistance of GP, which is related to the water content. A Kalman filter using an evapotranspiration model in combination with experimental data was used to refine the measurements, serving as the input for a model predictive controller (MPC). The MPC was used to improve the dynamics of the irrigation amount to more precisely achieve the required water content for regulated water uptake in plant studies. This is important in studies involving deficit irrigation. The novel method described was capable of increasing the accuracy of GP water content control. As a first step, the measurement system achieved an improved accuracy of 0.22 g/g. The application of a MPC for water content control based on the improved measurement results in an overall control accuracy was 0.09 g/g. This method offers a new approach, allowing the use of GP for studies with varying water content. This addressed the limitations of existing plant growth studies and allowed the prospection of dependencies between dynamic water deficit and plant development using GP as a growth substrate for research studies. [ABSTRACT FROM AUTHOR]

The metalized film capacitors (MFC) in converter valves are subjected to high-frequency currents under the action of power electronic switching, which will cause large differences in currents among capacitor elements inside MFC and seriously affect the stability of MFC. In this paper, experiments were conducted to measure the current waveforms among 90 elements under impulse, short-circuit discharge and sine waves at different frequencies. The equivalent circuit topology was simplified by using decoupling and controlled source equivalence, and parameters were extracted by electromagnetic calculations combined with experiments. Finally, an equivalent circuit model was established and the current distribution among elements was calculated. Influenced by the reactance of the parasitic inductor and the capacitor element, the frequency range can be divided into 3 regions based on the current distribution characteristics: in the high frequency range (>100 kHz), the current is mainly concentrated on several capacitor elements near the connection terminals. In the middle frequency range (about 10 kHz–100 kHz), the current oscillates between elements and the inductor, resulting in a wavy distribution of current amplitude, strongly influenced by frequency. In the low frequency range (<10 kHz), the current distribution varies very little among 90 elements. These results can support the study of performance evolution, fault analysis and design optimization in MFC. [ABSTRACT FROM AUTHOR]

Focuses on the recovery voltage method (RVM), a method used to estimate the polarization spectrum in composite oil/paper insulation systems. Methods for determining dielectric insulation; Mathematical description of the recovery voltage method; Identification of the equivalent circuit using a model with a single polarization capacitor.

Abstract: The requirements and development of high-k dielectric films for application in storage cells of future generation flash and Dynamic Random Access Memory (DRAM) devices are reviewed. Dielectrics with k-value in the 9–30 range are studied as insulators between charge storage layers and control gates in flash devices. For this application, large band gaps (>6eV) and band offsets are required, as well as low trap densities. Materials studied include aluminates and scandates. For DRAM metal–insulator–metal (MIM) capacitors, aggressive scaling of the equivalent oxide thickness (with targets down to 0.3nm) drives the research towards dielectrics with k-values >50. Due to the high aspect ratio of MIMCap structures, highly conformal deposition techniques are needed, triggering a substantial effort to develop Atomic Layer Deposition (ALD) processes for the deposition of metal gates and high-k dielectrics. Materials studied include Sr- and Ba-based perovskites, with SrTiO3 as one of the most promising candidates, as well as tantalates, titanates and niobates. [Copyright &y& Elsevier]

Abstract: We review our recent studies of the passivation of the GaAs and InGaAs surface using a combination of in situ and ex situ surface analysis and capacitor measurements. We find that the control of Ga-oxides in particular appears to play an important role in understanding the characteristics of III–V MOS devices. [Copyright &y& Elsevier]

Abstract: Atomic layer deposited (ALD) HfO2/GeO x N y /Ge(100) and Al2O3/In0.53Ga0.47As(100)−4×2 gate stacks were analyzed both by MOS capacitor electrical characterization and by advanced physical characterization to correlate the presence of electrically-active defects with chemical bonding across the insulator/channel interface. By controlled in situ plasma nitridation of Ge and post-ALD annealing, the capacitance-derived equivalent oxide thickness was reduced to 1.3nm for 5nm HfO2 layers, and mid-gap density of interface states, D it =3×1011 cm−2 eV−1, was obtained. In contrast to the Ge case, where an engineered interface layer greatly improves electrical characteristics, we show that ALD-Al2O3 deposited on the In0.53Ga0.47As (100)−4×2 surface after in situ thermal desorption in the ALD chamber of a protective As cap results in an atomically-abrupt and unpinned interface. By avoiding subcutaneous oxidation of the InGaAs channel during Al2O3 deposition, a relatively passive gate oxide/III–V interface is formed. [Copyright &y& Elsevier]

We developed a technique to directly observe at nanoscale resolution the degradation of gate SiO2 films observed in metal-oxide-semiconductor (MOS) capacitors by using conductive atomic force microscopy (C-AFM). As a result of observing gate SiO2 films subjected to a constant current stress, local leakage current spots related to the stress-induced leakage current (SILC) were detected. Distribution of defects induced by the electrical stress and the conduction mechanism of local leakage current caused by them are discussed. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 88(6): 18–26, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20123 [ABSTRACT FROM AUTHOR]

Here we report a highly sensitive single-axis membrane-type paper accelerometer. The accelerometer is consisted of a suspended parallel-plate sensing capacitor prepared by costeffective nano ink printing technologies on a flexible paper substrate. The proof mass and suspension bridge structures of the accelerometer are designed based on the simulation results for the optimization of sensitivity. Vertical acceleration sensitivity of the optimized design with long ellipse-shaped bridges and round-shaped proof mass can reach 20 fF/g at z-axis acceleration of 1–10 g. [ABSTRACT FROM AUTHOR]

The replacement of the anode material in tantalum capacitors by a new generation of high CV niobium powders offers the possibility to get an economical alternative to tantalum for a wide range of applications. Due to the high CV potential of niobium powder there is also an alternative to low voltage aluminum electrolytic capacitors. We developed a new niobium capacitor which shows stable electrical values. By optimizing the structure of the dielectric and the cathodic layers as well as the process parameters we gained a capacitor which can be used up to 105 °C. Electrical characteristics and lifetest behavior of niobium capacitors out of 100 k-150 k CV/g powder will be discussed. [ABSTRACT FROM AUTHOR]

A low frequency noise and charge carriers transport mechanism analysis was performed on tantalum capacitors in order to characterise their quality and reliability. The model of Ta-Ta 2 O 5 -MnO 2 MIS structure was used to give physical interpretation of VA characteristic both in normal and reverse modes. The self-healing process based on the high temperature MnO 2 -Mn 2 O 3 transformation was studied and its kinetic determined on the basis of noise spectral density changes. The correlation between leakage current and noise spectral density was evaluated and noise reliability indicator was suggested. In normal mode the noise spectral density at rated voltage increases with second power of current and it varies within two decades for given leakage current value. In reverse mode there is only weak correlation and for given applied voltage, the leakage current for all ensemble varies only by one order, whereas the noise spectral density of the same samples spread in five orders. [ABSTRACT FROM AUTHOR]

Discusses the stabilization of niobium-based solid electrolyte capacitors. Composition of electrolyte tantalum capacitors; Development of high efficiency ceramic capacitors and organic semiconductor capacitors; Consideration for the properties of niobium monooxide.

This research paper presents a symmetrical current-tunable active-RC all-pass filter that uses an active BJT coupled with R and C. The circuit's symmetrical structure ensures that the differential signals are treated equally, resulting in improved performance. Furthermore, the filter's ability to adjust the frequency by bias current makes it suitable for a wide range of applications, such as improving phase properties and creating other types of filters. The simulation results obtained through the Pspice program show that the value of the operating frequency can be adjusted by bias current, which is the highlight of this research. The transfer function of the circuit shows a response of about 0 dB and -90° respectively, indicating that the circuit can change the phase of the input signal without changing its magnitude. This feature is particularly useful in signal processing applications where phase changes are required. In addition, the paper discusses how the operating frequency can be increased by decreasing the capacitor. The transfer function of the circuit analyzed shows that the operating frequency (f0) is inversely proportional to the product of the capacitors. Therefore, decreasing the value of C increases the operating frequency of the circuit. Monte Carlo analysis results are also presented for resistors, capacitors, and transistors with error values. This analysis helps determine the effect of errors on the output signal of the circuit. The results show that the output signal is sensitive to changes in the resistor values, which can affect the accuracy of the filter. Therefore, it is important to select high-quality resistors to ensure that the filter operates accurately. [ABSTRACT FROM AUTHOR]

In recent years, there is an increased use of passive filters in both transmission and distribution systems due to the proliferation of power electronic devices. However, the problem of filter design has not been well addressed in the past and one example is the application of high-pass filters in a filter package. Three types of HP filters are widely used to mitigate multiple harmonics, i.e., 2nd HP filter, 3rd HP filter and C-type filter. There is still a lack of research to clearly reveal the characteristics of each filter, which makes it difficult for the designer to select the optimal filter topology under different circumstances. The main goal of this paper is to solve the problem of how to select a proper configuration among three HP filter candidates for a given harmonic problem. Unlike the conventional optimization-based filter studies, this paper investigates three HP filters in an analytical way. As a result, the paper provides a deep insight into the inherent characteristics of the filter and the conclusions drawn in the paper are universal; thus can be used in different applications, ranging from low voltage levels to high voltage levels. The research results lead to a recommended application scope of each HP filter, which is very useful to guide the design of filter packages and help designers to evaluate the design results. [ABSTRACT FROM AUTHOR]

This paper proposes a single-phase, transformer-less, seven-level inverter that utilizes eight switches, three capacitors, and two diodes to produce seven voltage levels with triple boosting ability. The availability of the common-ground point eliminates the leakage current in PV applications. The proposed Transformer-Less Triple-Boosting Seven-Level Inverter (TLTB7LI) has the ability to feed different types of loads from non-unity to unity power factors. The voltage balancing of capacitors takes place naturally without the need for auxiliary circuits and complicated control strategies. This paper investigates the appropriateness of the proposed TLTB7LI for grid-connected application. The Peak Current Controller (PCC) is employed to generate the switching pulses and regulate the active/reactive power transfer between the converter and the output, which guarantees the high quality of injected current to the output. Moreover, the operational principles, its control technique, as well as the design procedure of the key components of the proposed inverter have been presented. The superiority of the proposed inverter over existing counterparts has been verified through comparative analysis. The simulation and experimental analysis validated the proper operation of the proposed TLTB7LI. [ABSTRACT FROM AUTHOR]

A grid-forming wind generation system exhibits exceptional grid frequency support abilities. The DC capacitor of the grid-forming wind generation system, which is characterized by rapid response and high sensitivity to minor disturbances, can provide short-term inertia support for the power system. This paper proposes the capacitor virtual inertia control for the grid-forming wind generation system, coupling the DC capacitor voltage with the power system frequency, which enables the DC capacitor to participate in the system frequency response process and reduces the rate of change of the system frequency during the disturbance. To analyze the inertia of the wind power generation system, this paper establishes an equivalent Philips-Heffron model for the grid-forming wind generation system and uses the equivalent inertia constant to quantify the inertia of the wind power generation system. The effectiveness of the proposed control strategy and the reasonableness of the inertia assessment method are verified through simulations in the single-turbine system and the IEEE four-machine two-area system. [ABSTRACT FROM AUTHOR]

Power converters enhance the DC-AC power supply by using multi-level inverters based on switched capacitor technology. The voltage stress on the switches in switched capacitor-based multi-level inverters decreases as the number of switches rises, and vice versa when the number of switches falls. This paper suggests a quadruple boost nine-level inverter based on a switched capacitor with a single voltage source to address this issue. Only nine switches are used in the suggested architecture to implement the inverter with two diodes and two capacitors. Since the diodes and capacitors are linked to the low voltage input side, the total voltage stress of the inverter is kept low even at the elevated for quadruple boost output voltage. The theoretical study, computations, and design parameters of the nine-level inverter are presented in this paper. The switching specifics of the seven-level boost extension topology are also reported in this work. Simulations and laboratory tests on a 120 W inverter prototype have confirmed the viability of the suggested topology. [ABSTRACT FROM AUTHOR]

In this paper, a new structure for a 1-bit full adder is proposed based on dynamic logic methodology, which utilises pass transistors. The clocking operation falls into two phases. The clocking operation consists of a pre-discharged cycle, during which pseudo capacitors are reset to zero when the clock signal is high, and an evaluation cycle, during which the circuit outputs the adder function when the clock signal is low. The circuit uses a combination of 12 pass-transistors to better implement the full adder logic function with the maximum of a NMOS threshold voltage drop. Moreover, the circuit has no direct connection to the power-supply node and so this can possibly save the power dissipation. Our new adder outperforms other 1-bit full adder structures in terms of power-delay factor, according to simulation results. [ABSTRACT FROM AUTHOR]