Sample records for cell flying capacitor

  1. Practical Results of a Five-level Flying Capacitor Inverter

    O. Sivkov


    Full Text Available This paper investigates the realization of a five-level Flying Capacitor Inverter. After a brief description of general Power Electronic Converters and an introduction to the advantages of Multilevel Inverters over conventional two-level Inverters the main focus is on the five-level Flying Capacitor Inverter. The Flying Capacitor Multilevel Inverter (FCMI is a Multilevel Inverter (MI where the capacitor voltage can be balanced using only a control strategy for any number of levels. After a general description of five-level FCMI topology, the simulation and experimental results are presented. The capacitor voltage is stabilized here with various output voltage amplitude values. The simulation and experimental results of five-level FCMI show that the voltage is stabilized on capacitors using the control strategy. A single-phase five-level FCMI model is currently being developed and constructed in the laboratory. Some of the experimental results are available.

  2. Test demonstration of magnet power supply with the flying capacitor

    Japan Proton Accelerator Research Complex (J-PARC) aims at achieving a MW-class proton accelerator facility. One of the promising solutions for increasing the beam power is to fasten the repetition rate of Main Ring (MR) from current rating of 2.5 sec to 1 sec in the future. However, in this scheme, the increase of output voltage and the power variation on the electric system are serious concerns for main magnets. We have considered that the energy recovery scheme based on capacitive energy storage is one of the best solution to compensate the power variation induced by a magnet power supply. In order to achieve the idea, we have decided to innovate the flying capacitor method to produce the high output voltage and return the capacitor energy with magnetic energy. However driving power supply with the flying capacitor method needs to establish the charging method of them in each pattern. In this article, we report the test result of magnetic power supply with the mini model of the power supply using the flying capacitor method. (author)

  3. New zero voltage switching DC converter with flying capacitors

    Lin, Bor-Ren; Shiau, Tung-Yuan


    A new soft switching converter is presented for medium power applications. Two full-bridge converters are connected in series at high voltage side in order to limit the voltage stress of power switches at Vin/2. Therefore, power metal-oxide-semiconductor field-effect transistors (MOSFETs) with 600 V voltage rating can be adopted for 1200 V input voltage applications. In order to balance two input split capacitor voltages in every switching cycle, two flying capacitors are connected on the AC side of two full-bridge converters. Phase-shift pulse-width modulation (PS-PWM) is adopted to regulate the output voltage. Based on the resonant behaviour by the output capacitance of MOSFETs and the resonant inductance, active MOSFETs can be turned on under zero voltage switching (ZVS) during the transition interval. Thus, the switching losses of power MOSFETs are reduced. Two full-bridge converters are used in the proposed circuit to share load current and reduce the current stress of passive and active components. The circuit analysis and design example of the prototype circuit are provided in detail and the performance of the proposed converter is verified by the experiments.

  4. Bulk Modulus Capacitor Load Cells

    Measurement of forces present at various locations within the SSC Model Dipole collared coil assembly is of great practical interest to development engineers. Of particular interest are the forces between coils at the parting plane and forces that exist between coils and pole pieces. It is also desired to observe these forces under the various conditions that a magnet will experience such as: during the collaring process, post-collaring, under the influence of cryogens, and during field excitation. A twenty eight thousandths of an inch thick capacitor load cell which utilizes the hydrostatic condition of a stressed plastic dielectric has been designed. These cells are currently being installed on SSC Model Dipoles. The theory, development, and application of these cells will be discussed

  5. Active control of flying capacitor currents in multilevel voltage-source inverters

    Kokeš, Petr; Semerád, Radko


    Roč. 58, č. 4 (2013), s. 393-410. ISSN 0001-7043 Institutional support: RVO:61388998 Keywords : voltage source inverter (VSI) * multilevel inverter * flying capacitor Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  6. High Step-Up 3-Phase Rectifier with Fly-Back Cells and Switched Capacitors for Small-Scaled Wind Generation Systems

    Yi-Feng Wang


    Full Text Available This paper proposes and discusses a novel AC/DC converter suitable for small-scaled wind power generation system applications. By introducing flyback cells into the three-phase single-switch Boost circuit, the proposed converter is designed as single-stage and has both rectification and high step-up power conversion functions. It is able to obtain high voltage gain at low input voltage level, and high efficiency, low total harmonic distortion (THD at rated power. The inherent power factor correction (PFC is also determined, and can reach 0.99. Besides, since no electrolytic capacitor is employed and high voltage gain is achieved, the converter can also collect weak power at low input voltage in combination with energy storage devices, and contribute to a better low-wind-speed/low-power performance. Finally, a 400 W prototype is built to verify the theoretical analysis, and its efficiency is 87.6%, while THD is 7.4% at rated power.

  7. Simulation Study of the Carrier-Based PWM Method in Three- Phase Flying Capacitor Inverters

    Adrian Şchiop


    This paper is a simulation study ofmodulation strategies in three-phase flying capacitorinverters. Under investigation are those strategies thatsolve the capacitor voltage balancing problem: phaseshiftPWM method, the saw-tooth rotation PWM methodand carrier redistribution PWM method. The results areshown through simulation.

  8. Floating body cell a novel capacitor-less DRAM cell

    Ohsawa, Takashi


    DRAM together with NAND Flash is driving semiconductor technologies with wide spectrum of usage ranging from PC, mobile phone and digital home appliances to solid-state disk (SSD). However, the DRAM cell which consists of a data storage capacitor (1C) and a switching transistor (1T) is facing serious difficulty in shrinking the size of the capacitor whose capacitance needs to be kept almost constant (20~30fF) throughout generations. The availability of a new DRAM cell which does not rely on an explicit capacitor for storing its data is more than ever awaited for further increasing the bit dens




    Full Text Available This paper presents the comparison of unipolar multicarrier Pulse Width Modulation (PWM techniques for the Flying Capacitor Multi Level Inverter (FCMLI. Due to switch combination redundancies, there are certain degrees of freedom to generate the five level AC output voltage. This paper presents the use of Control Freedom Degree (CFD combination. The effectiveness of the PWM strategies developed using CFD are demonstrated by simulation and experimentation. The results indicate that the multilevel inverter triggered by the developed USHPWM strategy exhibits reduced harmonics. PWM strategies developed are implemented in real time using dSPACE/Real Time Interface (RTI. The simulation and experimental output closely match with each other validating the strategies presented.

  10. Powering microbial electrolysis cells by capacitor circuits charged using microbial fuel cell

    Hatzell, Marta C.


    A microbial electrolysis cell (MEC) was powered by a capacitor based energy storage circuit using energy from a microbial fuel cell (MFC) to increase MEC hydrogen production rates compared to that possible by the MFC alone. To prevent voltage reversal, MFCs charged the capacitors in a parallel configuration, and then the capacitors were discharged in series to boost the voltage that was used to power the MECs. The optimal capacitance for charging was found to be ∼0.01 F for each MFC. The use of the capacitor charging system increased energy recoveries from 9 to 13%, and hydrogen production rates increased from 0.31 to 0.72 m3 m-3-day-1, compared to coupled systems without capacitors. The circuit efficiency (the ratio of the energy that was discharged to the MEC to the energy provided to the capacitor from the MFCs) was ∼90%. These results provide an improved method for linking MFCs to MECs for renewable hydrogen gas production. © 2012 Elsevier B.V. All rights reserved.

  11. Digital Control of a power conditioner for fuel cell/super-capacitor hybrid system

    Caballero, Juan C Trujillo; Gomis-Bellmunt, Oriol; Montesinos-Miracle, Daniel;


    This article proposes a digital control scheme to operate a proton exchange membrane fuel cell module of 1.2 kW and a super-capacitor through a DC/DC hybrid converter. A fuel cell has been proposed as a primary source of energy, and a super-capacitor has been proposed as an auxiliary source of...... energy. Experimental validation of the system implemented in the laboratory is provided. Several tests have been performed to verify that the system achieves excellent output voltage (V0) regulation and super-capacitor voltage (V SC) control under disturbances from fuel cell power (PFC) and output power...

  12. Miniature wire-shaped solar cells, electrochemical capacitors and lithium-ion batteries

    Shaowu Pan; Zhitao Zhang; Wei Weng; Huijuan Lin; Zhibin Yang; Huisheng Peng


    It is critically important to develop miniature energy harvesting and storage devices in modern electronics, for example, for portable and foldable electronic facilities. In this review article, novel miniature solar cells, electrochemical capacitors and lithium-ion batteries as well as their integrated devices are carefully summarized. Particular emphasis has been paid to wire-shape energy devices that exhibit unique and promising advantages such as being lightweight and weaveable compared w...

  13. Miniature wire-shaped solar cells, electrochemical capacitors and lithium-ion batteries

    Shaowu Pan


    Full Text Available It is critically important to develop miniature energy harvesting and storage devices in modern electronics, for example, for portable and foldable electronic facilities. In this review article, novel miniature solar cells, electrochemical capacitors and lithium-ion batteries as well as their integrated devices are carefully summarized. Particular emphasis has been paid to wire-shape energy devices that exhibit unique and promising advantages such as being lightweight and weaveable compared with the conventional planar architecture. Recent new materials and attractive designs are highlighted for these wire-shaped energy devices.

  14. Super-capacitors fuel-cell hybrid electric vehicle optimization and control strategy development

    In the last decades, due to emissions reduction policies, research focused on alternative powertrains among which hybrid electric vehicles (HEVs) powered by fuel cells are becoming an attractive solution. One of the main issues of these vehicles is the energy management in order to improve the overall fuel economy. The present investigation aims at identifying the best hybrid vehicle configuration and control strategy to reduce fuel consumption. The study focuses on a car powered by a fuel cell and equipped with two secondary energy storage devices: batteries and super-capacitors. To model the powertrain behavior an on purpose simulation program called ECoS has been developed in Matlab/Simulink environment. The fuel cell model is based on the Amphlett theory. The battery and the super-capacitor models account for charge/discharge efficiency. The analyzed powertrain is also equipped with an energy regeneration system to recover braking energy. The numerical optimization of vehicle configuration and control strategy of the hybrid electric vehicle has been carried out with a multi objective genetic algorithm. The goal of the optimization is the reduction of hydrogen consumption while sustaining the battery state of charge. By applying the algorithm to different driving cycles, several optimized configurations have been identified and discussed

  15. Fractal capacitors

    Samavati, Hirad; Hajimiri, Ali; Shahani, Arvin R.; Nasserbakht, Gitty N.; Lee, Thomas H.


    A linear capacitor structure using fractal geometries is described. This capacitor exploits both lateral and vertical electric fields to increase the capacitance per unit area. Compared to standard parallel-plate capacitors, the parasitic bottom-plate capacitance is reduced. Unlike conventional metal-to-metal capacitors, the capacitance density increases with technology scaling. A classic fractal structure is implemented with 0.6-μm metal spacing, and a factor of 2.3 increase in the capacitan...

  16. An Automatic Switched-Capacitor Cell Balancing Circuit for Series-Connected Battery Strings

    Yuanmao Ye


    Full Text Available In this paper, a novel voltage equalizer is developed for series battery strings based on the two-phase switched capacitor technique. Different from the conventional voltage equalizers which are developed by switched-mode power converters, bulky magnetic components and complex monitoring and control system are avoided in the proposed system. Just a pair of complementary pulse signals with constant switching frequency and fixed duty ratio are required to control all of switches employed in the proposed voltage equalizer, and charge transfers from the higher voltage battery cells to lower voltage ones automatically. The circuit configuration and operation principle are provided in this paper. The model of the proposed voltage equalizer is also derived. Comparison with other works indicates that the proposed method is superior to the conventional switched-capacitor (SC voltage equalizer for the high stack of series battery strings. Experimental results demonstrate that the proposed voltage equalization system is capable of excellent voltage balancing performance with a simple control method.

  17. Unsubstituted polyaromatic hydrocarbons (PAH's) in extracts of coal fly ash from the fly ash test cell in Montour, Pennsylvania

    Isotope Dilution Mass Spectrometry (IDMS) was used to identify and to quantify trace amounts of selected, unsubstituted polyaromatic hydrocarbons (PAH's) present in extracts of coal fly ash from the solid waste disposal test cell at Montour, Pennsylvania. Isotope dilution experiments using deuterated analogs of polyaromatic hydrocarbons demonstrated that the concentrations of benzo[a]pyrene and anthracene were lower than 1 ng/g of fly ash. Isotope dilution experiments demonstrated that benzo[a]pyrene could be detected at concentrations as high as 1 ng/g when an isotopic carrier was used at a concentration of 125 ng/g in the analytical method. Maximum concentrations of fluorene, fluoranthene, pyrene and chrysene were conservatively estimated to be 3 ng/g of fly ash, using a 95 percent confidence interval based on analytical precision of ±1 ng/g of fly ash. Concentrations of phenanthrene were found to range from 6 to 38 ng/g of fly ash with a mean concentration of 14 ng/g of fly ash. Two sources of phenanthrene were speculated: incomplete combustion of phenanthrene in the coal furnace and addition of phenanthrene to the fly ash after collection by electrostatic precipitators

  18. Use of super-capacitors in the motorization of fuel cell electric powered vehicles; Utilisation de supercondensateurs dans la motorisation de vehicules electriques a pile a combustible

    Djerdir, A.; Gualous, H.; Berthon, A. [L2ES, IGE, 90 - Belfort (France); Bouquain, D. [CREEBEL, 90 - Belfort (France); Ayad, M.Y.; Rasoanarivo, I.; Rael, S.; Davat, B. [GREEN, 54 - Vandoeuvre les Nancy (France)


    The aim of this work is to integrate super-capacitors in a fuel cell vehicle as an auxiliary energy source able to provide and to recover an energy power. The super-capacitors elements are got together in series/parallel and inserted on-board of the vehicle. A tension level and an energy converter/packager have been chosen. (O.M.)

  19. Generalized Multi-Cell Switched-Inductor and Switched-Capacitor Z-source Inverters

    Li, Ding; Chiang Loh, Poh; Zhu, Miao;


    . Their boosting gains are, therefore, limited in practice. To overcome these shortcomings, the generalized switched-inductor and switched-capacitor Z-source inverters are proposed, whose extra boosting abilities and other advantages have already been verified in simulation and experiment....

  20. Rotary capacitor


    The rotating wheel of the rotary capacitor representing the most critical part of the new radio-frequency system of the synchro-cyclotron. The three rows of teeth on the circumference of the wheel pass between four rows of stator blades with a minimum clearance of 1 mm at a velocity of 1700 rev/min.

  1. Sliding mode control of an autonomous parallel fuel cell-super capacitor power source

    More, Jeronimo J. [Universidad Nacional de La Plata (UNLP), La Plata, Buenos Aires (Argentina). Facultad de Ingenieria. Lab. de Electronica Industrial, Control e Instrumentacion], Email:; Puleston, Paul F. [Consejo de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina); Kunusch, Cristian; Colomer, Jordi Riera I. [Universitat Politecnica de Catalunya, Barcelona (Spain). Inst. de Robotica i Informatica Industrial (IRII)


    Nowadays, hydrogen fuel cell (FC) based systems emerge as one promising renewable alternative to fossil fuel systems in automotive and residential applications. However, their output dynamic response is relatively slow, mostly due to water and reactant gases dynamics. To overcome this limitation, FC-super capacitors (SCs) topologies can be used. The latter is capable of managing very fast power variations, presenting in addition high power density, long life cycle and good charge/discharge efficiency. In this work, a FC-SCs-based autonomous hybrid system for residential applications is considered. The FC and SCs are connected in parallel, through two separate DC/DC converters, to a DC bus. Under steady state conditions, the FC must deliver the load power requirement, while maintaining the SCs voltage regulated to the desired value. Under sudden load variations, the FC current rate must be limited to assure a safe transition to the new point of operation. During this current rate limitation mode, the SCs must deliver or absorb the power difference. To this end, a sliding mode strategy is proposed to satisfy to control objectives. The main one is the robust regulation of the DC bus voltage, even in the presence of system uncertainties and disturbances, such as load changes and FC voltage variations. Additionally, a second control objective is attained, namely to guarantee the adequate level of charge in the SCs, once the FC reaches the new steady state operation point. In this way, the system can meet the load power demand, even under sudden changes, and it can also satisfy a power demand higher than the nominal FC power, during short periods. The proposed control strategy is evaluated exhaustively by computer simulation considering fast load variations. The results presented in this work, corresponds to the first stage of a R and D collaboration project for the design and development of a novel FC-SCs-based autonomous hybrid system. In the next phase, the proposed

  2. Study of the selective effect on cells induced by nanosecond pulsed electric field with the resistor-capacitor circuit model

    Xu Fei; Xiao Dengming; Li Zhaozhi


    A resistor-capacitor (RC) circuit model is proposed to study the effect of nanosecond pulsed electric field on cells according to the structure and electrical parameters of cells. After a nanosecond step field has been applied, the variation of voltages across cytomembrane and mitochondria membrane both in normal and in malignant cells are studied with this model. The time for selectively targeting the mitochondria membrane and malignant cell can be evaluated much easily with curves that show the variation of voltage across each membrane with time. Ramp field is the typical field applied in electrobiology. The voltages across each membrane induced by ramp field are analyzed with this model. To selectively target the mitochondria membrane, proper range of ramp slope is needed. It is relatively difficult to decide the range of a slope to selectively affect the malignant cell. Under some conditions, such a range even does not exist.

  3. Switched-capacitor isolated LED driver

    Sanders, Seth R.; Kline, Mitchell


    A switched-capacitor voltage converter which is particularly well-suited for receiving a line voltage from which to drive current through a series of light emitting diodes (LEDs). Input voltage is rectified in a multi-level rectifier network having switched capacitors in an ascending-bank configuration for passing voltages in uniform steps between zero volts up to full received voltage V.sub.DC. A regulator section, operating on V.sub.DC, comprises switched-capacitor stages of H-bridge switching and flying capacitors. A current controlled oscillator drives the states of the switched-capacitor stages and changes its frequency to maintain a constant current to the load. Embodiments are described for isolating the load from the mains, utilizing an LC tank circuit or a multi-primary-winding transformer.

  4. Analysis and Design of a Bidirectional Isolated DC-DC Converter for Fuel Cell and Super-Capacitor Hybrid System

    Zhang, Zhe; Ouyang, Ziwei; Thomsen, Ole Cornelius;


    Electrical power system in future uninterruptible power supply (UPS) or electrical vehicle (EV) may employ hybrid energy sources, such as fuel cells and super-capacitors. It will be necessary to efficiently draw the energy from these two sources as well as recharge the energy storage elements by...... the DC bus. In this paper, a bidirectional isolated DC-DC converter controlled by phase-shift and duty cycle for the fuel cell hybrid energy system is analyzed and designed. The proposed topology minimizes the number of switches and their associated gate driver components by using two high frequency...... transformers which combine a half-bridge circuit and a full-bridge circuit together on the primary side. The voltage doubler circuit is employed on the secondary side. The current-fed input can limit the input current ripple that is favorable for fuel cells. The parasitic capacitance of the switches is used...

  5. Quantum, Photo-Electric Single Capacitor Paradox

    Kapor, Darko


    In this work single capacitor paradox (a variation of the remarkable two capacitor paradox) is considered in a new, quantum discrete form. Simply speaking we consider well-known usual, photoelectric effect experimental device, i.e. photo electric cell, where cathode and anode are equivalently charged but non-connected. It, obviously, represents a capacitor that initially, i.e. before action of the photons with individual energy equivalent to work function, holds corresponding energy of the electrical fields between cathode and anode. Further, we direct quantum discretely photons, one by one, toward cathode where according to photo-electrical effect electrons discretely, one by one, will be emitted and directed toward anode. It causes discrete discharge of the cell, i.e. capacitor and discrete decrease of the electrical field. Finally, total discharge of the cell, i.e. capacitor, and total disappearance of the electrical field and its energy will occur. Given, seemingly paradoxical, capacitor total energy loss...

  6. Formation of reactive oxygen species in rat epithelial cells upon stimulation with fly ash

    K Voelkel; H F Krug; S Diabaté


    Fly ash was used as a model for ambient particulate matter which is under suspicion to cause adverse pulmonary health effects. The fly ash was pre-sized and contained only particles < 20 m including an ultrafine fraction (< 100 nm) that contributed 31% to the particle number. In our study, we investigated the influence of fly ash on the promotion of early inflammatory reactions like the formation of reactive oxygen species (ROS) in rat lung epithelial cells (RLE-6TN). Furthermore, we determined the formation of nitric oxide (NO). The cells show a clear dose-response relationship concerning the formation of ROS with regard to the mass of particles applied. Lipopolysaccharide (LPS) added as a co-stimulus did not increase the formation of ROS induced by fly ash. Furthermore, in LPS (0.1 g/ml) and tumour necrosis factor-alpha (TNF-alpha; 1 ng/ml) pre-treated cells no increase in reactive oxygen species comparable to fly ash alone is observable. In presence of the metal chelator, desferrioxamine (DFO), ROS formation can be significantly reduced. Neither fly ash nor LPS induced a significant NO release in RLE-6TN cells.

  7. Capacitors with low equivalent series resistance

    Fleig, Patrick Franz (Inventor); Lakeman, Charles D. E. (Inventor); Fuge, Mark (Inventor)


    An electric double layer capacitor (EDLC) in a coin or button cell configuration having low equivalent series resistance (ESR). The capacitor comprises mesh or other porous metal that is attached via conducting adhesive to one or both the current collectors. The mesh is embedded into the surface of the adjacent electrode, thereby reducing the interfacial resistance between the electrode and the current collector, thus reducing the ESR of the capacitor.

  8. Design of an hybrid source with fuel cell and super-capacitors; Conception d'une source hybride utilisant une pile a combustible et des supercondensateurs

    Thounthong, Ph.


    The design and testing of a purely super-capacitor energy storage device as auxiliary power source in electrical vehicle applications having a PEM fuel cell as main source are presented. The two control strategies are explained. The control algorithms are that fuel cell is simply operating in almost steady state conditions in order to lessen the mechanical stresses of fuel cell and to ensure a good synchronization between fuel flow and fuel cell current. Super-capacitors are functioning during absence of energy from fuel cell, transient energy delivery or transient energy recovery. The system utilizes two modules of SAFT super-capacitive storage device. This device is connected to a 42 V DC bus by a 2-quadrant dc/dc converter, and fuel cell is connected to the dc bus by a boost converter. The system structure is realized by analogical current loops and digital control (dSPACE) for voltage loops and estimation algorithms. Experimental results with a 500 W PEM fuel cell point out the slow dynamics naturally of fuel cell because of thermodynamic and mechanical operation, and also substantiate that the super-capacitors can improve dynamics and power conditioning for automotive electrical system. (author)

  9. On-Orbit Demonstration Of Thin-Film Multi-Junction Solar Cells And Lithium-Ion Capacitors As Bus Components

    Kukita, Akio; Takahashi, Masato; Shimazaki, Kazunori; Toyota, Hiroyuki; Imaizumi, Mitsuru; Kobayashi, Yuki; Takamoto, Tatsuya; Uno, Masatoshi; Shimada, Takanobu


    This paper describes an on-orbit demonstration plan for a lightweight solar panel using thin-film multi-junction (MJ) solar cells and aluminum-laminated lithium-ion capacitors (LICs). Thin-film MJ solar cells such as inverted metamorphic InGaP/GaAs/InGaAs 3J cells have flexibility as well as conversion efficiencies superior to conventional rigid 3J solar cells. A substantial reduction of satellite mass is achieved by the combination of thin-film MJ solar cells and light flexible paddles. An LIC is a hybrid-type capacitor that uses activated carbon as the cathode and carbon material pre-doped with lithium ion as the anode. LICs can be rapidly charged and discharged, and can operate in a wide temperature range for long periods. LICs are therefore suitable for long-term missions such as planetary explorations. Although these devices are very promising, so far there has been no opportunity to demonstrate their use in orbit. A lightweight thin solar panel with thin-film MJ solar cells will be installed on the Small Scientific Satellite Platform for Rapid Investigation and Test-A (SPRINT-A) satellite, which will be launched on the Epsilon launch vehicle in 2013. Utilizing the capacitor-like voltage behavior of LICs, we will employ a simple constant-power charging circuit without feedback control.

  10. Mutations in the Borrelia burgdorferi Flagellar Type III Secretion System Genes fliH and fliI Profoundly Affect Spirochete Flagellar Assembly, Morphology, Motility, Structure, and Cell Division

    Gao, Lihui; Zhao, Xiaowei; Liu, Jun; Norris, Steven J.


    ABSTRACT The Lyme disease spirochete Borrelia burgdorferi migrates to distant sites in the tick vectors and mammalian hosts through robust motility and chemotaxis activities. FliH and FliI are two cytoplasmic proteins that play important roles in the type III secretion system (T3SS)-mediated export and assembly of flagellar structural proteins. However, detailed analyses of the roles of FliH and FliI in B. burgdorferi have not been reported. In this study, fliH and fliI transposon mutants were utilized to dissect the mechanism of the Borrelia type III secretion system. The fliH and fliI mutants exhibited rod-shaped or string-like morphology, greatly reduced motility, division defects (resulting in elongated organisms with incomplete division points), and noninfectivity in mice by needle inoculation. Mutants in fliH and fliI were incapable of translational motion in 1% methylcellulose or soft agar. Inactivation of either fliH or fliI resulted in the loss of the FliH-FliI complex from otherwise intact flagellar motors, as determined by cryo-electron tomography (cryo-ET). Flagellar assemblies were still present in the mutant cells, albeit in lower numbers than in wild-type cells and with truncated flagella. Genetic complementation of fliH and fliI mutants in trans restored their wild-type morphology, motility, and flagellar motor structure; however, full-length flagella and infectivity were not recovered in these complemented mutants. Based on these results, disruption of either fliH or fliI in B. burgdorferi results in a severe defect in flagellar structure and function and cell division but does not completely block the export and assembly of flagellar hook and filament proteins. PMID:25968649

  11. Fly-FUCCI: A Versatile Tool for Studying Cell Proliferation in Complex Tissues

    Norman Zielke


    Full Text Available One promising approach for in vivo studies of cell proliferation is the FUCCI system (fluorescent ubiquitination-based cell cycle indicator. Here, we report the development of a Drosophila-specific FUCCI system (Fly-FUCCI that allows one to distinguish G1, S, and G2 phases of interphase. Fly-FUCCI relies on fluorochrome-tagged degrons from the Cyclin B and E2F1 proteins, which are degraded by the ubiquitin E3-ligases APC/C and CRL4Cdt2, during mitosis or the onset of S phase, respectively. These probes can track cell-cycle patterns in cultured Drosophila cells, eye and wing imaginal discs, salivary glands, the adult midgut, and probably other tissues. To support a broad range of experimental applications, we have generated a toolkit of transgenic Drosophila lines that express the Fly-FUCCI probes under control of the UASt, UASp, QUAS, and ubiquitin promoters. The Fly-FUCCI system should be a valuable tool for visualizing cell-cycle activity during development, tissue homeostasis, and neoplastic growth.

  12. A High-Performance Operational Amplifier for High-Speed High-Accuracy Switch-Capacitor Cells

    Qi Fan; Ning Ning; Qi Yu; Da Chen


    A highspeed highaccuracy fully differenttial operational amplifier (opamp) is realized based on noMillercapacitor feedforward (NMCF) compensation scheme. In order to achieve a good phase margin, the NMCF compensation scheme uses the positive phase shift of lefthalfplane (LHP) zero caused by the feedforward path to counteract the negative phase shift of the nondominant pole. Compared to traditional Miller compensation method, the opamp obtains high gain and wide band synchronously without the polesplitting effect while saves significant chip area due to the absence of the Miller capacitor. Simulated by the 0.35 μm CMOS RF technology, the result shows that the openloop gain of the opamp is 118 dB with the unity gainbandwidth (UGBW)of 1 GHz, and the phase margin is 61°while the settling time is 5.8 ns when achieving 0.01% accuracy. The opamp is especially suitable for the frontend sample/hold (S/H)cell and the multiplying D/A converter(MDAC) module of the highspeed highresolution pipelined A/D converters(ADCs).

  13. EWS-FLI1 inhibits TNFα-induced NFκB-dependent transcription in Ewing sarcoma cells

    Research highlights: → EWS-FLI1 interferes with TNF-induced activation of NFκB in Ewing sarcoma cells. → EWS-FLI1 knockdown in Ewing sarcoma cells increases TNF-induced NFκB binding to DNA. → EWS-FLI1 reduces TNF-stimulated NFκB-dependent transcriptional activation. → Constitutive NFκB activity is not affected by EWS-FLI1. → EWS-FLI1 physically interacts with NFκB p65 in vivo. -- Abstract: Ewing sarcoma is primarily caused by a t(11;22) chromosomal translocation encoding the EWS-FLI1 fusion protein. To exert its oncogenic function, EWS-FLI1 acts as an aberrant transcription factor, broadly altering the gene expression profile of tumor cells. Nuclear factor-kappaB (NFκB) is a tightly regulated transcription factor controlling cell survival, proliferation and differentiation, as well as tumorigenesis. NFκB activity is very low in unstimulated Ewing sarcoma cells, but can be induced in response to tumor necrosis factor (TNF). We wondered whether NFκB activity could be modulated by EWS-FLI1 in Ewing sarcoma. Using a knockdown approach in Ewing sarcoma cells, we demonstrated that EWS-FLI1 has no influence on NFκB basal activity, but impairs TNF-induced NFκB-driven transcription, at least in part through inhibition of NFκB binding to DNA. We detected an in vivo physical interaction between the fusion protein and NFκB p65, which could mediate these effects. Our findings suggest that, besides directly controlling the activity of its primary target promoters, EWS-FLI1 can also indirectly influence gene expression in tumor cells by modulating the activity of key transcription factors such as NFκB.

  14. FOXO1 is a direct target of EWS-Fli1 oncogenic fusion protein in Ewing's sarcoma cells

    Research highlights: → Inducible and reversible siRNA knockdown of an oncogenic fusion protein such as EWS-Fli1 is feasible and more advantageous than other siRNA methods. → The tumor suppressor gene FOXO1 is a new EWS-Fli1 target. → While trans-activators are known for the FOXO1 gene, there has been no report on negative regulators of FOXO1 transcription. → This study provides first evidence that the EWS-Fli1 oncogenic fusion protein can function as a transcriptional repressor of the FOXO1 gene. -- Abstract: Ewing's family tumors are characterized by a specific t(11;22) chromosomal translocation that results in the formation of EWS-Fli1 oncogenic fusion protein. To investigate the effects of EWS-Fli1 on gene expression, we carried out DNA microarray analysis after specific knockdown of EWS-Fli1 through transfection of synthetic siRNAs. EWS-Fli1 knockdown increased expression of genes such as DKK1 and p57 that are known to be repressed by EWS-Fli1 fusion protein. Among other potential EWS-Fli1 targets identified by our microarray analysis, we have focused on the FOXO1 gene since it encodes a potential tumor suppressor and has not been previously reported in Ewing's cells. To better understand how EWS-Fli1 affects FOXO1 expression, we have established a doxycycline-inducible siRNA system to achieve stable and reversible knockdown of EWS-Fli1 in Ewing's sarcoma cells. Here we show that FOXO1 expression in Ewing's cells has an inverse relationship with EWS-Fli1 protein level, and FOXO1 promoter activity is increased after doxycycline-induced EWS-Fli1 knockdown. In addition, we have found that direct binding of EWS-Fli1 to FOXO1 promoter is attenuated after doxycycline-induced siRNA knockdown of the fusion protein. Together, these results suggest that suppression of FOXO1 function by EWS-Fli1 fusion protein may contribute to cellular transformation in Ewing's family tumors.

  15. Towards Prognostics of Electrolytic Capacitors

    National Aeronautics and Space Administration — A remaining useful life prediction algorithm and degradation model for electrolytic capacitors is presented. Electrolytic capacitors are used in several...

  16. Single Capacitor Paradox

    Pankovic, Vladan


    In this work single capacitor paradox (a variation of the remarkable two capacitor paradox) is considered. Simply speaking in an ideal (without any electrical resistance and inductivity) electrical circuit with single charged capacitor and switch, by transition from initial, open state (switch in OFF position) in the final, closed state (switch in ON position), there is a total loss of the initial energy of the electrical field in condenser. Given energy loss can be simply explained without any dissipative effects (Joule heating or electromagnetic waves emission) by work of the electrical field by movement of the charge from one in the other plate of the capacitor. (Two capacitors paradox can be, obviously, explained in the analogous way.)

  17. Englerin A Inhibits EWS-FLI1 DNA Binding in Ewing Sarcoma Cells.

    Caropreso, Vittorio; Darvishi, Emad; Turbyville, Thomas J; Ratnayake, Ranjala; Grohar, Patrick J; McMahon, James B; Woldemichael, Girma M


    High-throughput screening of extracts from plants, marine, and micro-organisms led to the identification of the extract from the plant Phyllanthus engleri as the most potent inhibitor of EWS-FLI1 induced luciferase reporter expression. Testing of compounds isolated from this extract in turn led to the identification of Englerin A (EA) as the active constituent of the extract. EA induced both necrosis and apoptosis in Ewing cells subsequent to a G2M accumulation of cells in the cell cycle. It also impacted clonogenic survival and anchorage-independent proliferation while also decreasing the proportion of chemotherapy-resistant cells identified by high ALDH activity. EA also caused a sustained increase in cytosolic calcium levels. EA appears to exert its effect on Ewing cells through a decrease in phosphorylation of EWS-FLI1 and its ability to bind DNA. This effect is mediated, at least in part, through a decrease in the levels of the calcium-dependent protein kinase PKC-βI after a transient up-regulation. PMID:26961871

  18. Anti-oxidative and inflammatory responses induced by fly ash particles and carbon black in lung epithelial cells

    Diabate, Silvia; Plaumann, Diana; Uebel, Caroline; Weiss, Carsten [Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Eggenstein-Leopoldshafen (Germany); Bergfeldt, Britta [Karlsruhe Institute of Technology, Institute of Technical Chemistry, Eggenstein-Leopoldshafen (Germany)


    Combustion-derived nanoparticles as constituents of ambient particulate matter have been shown to induce adverse health effects due to inhalation. However, the components inducing these effects as well as the biological mechanisms are still not fully understood. The fine fraction of fly ash particles collected from the electrostatic precipitator of a municipal solid waste incinerator was taken as an example for real particles with complex composition released into the atmosphere to study the mechanism of early biological responses of BEAS-2B human lung epithelial cells. The studies include the effects of the water-soluble and -insoluble fractions of the fly ash and the well-studied carbon black nanoparticles were used as a reference. Fly ash induced reactive oxygen species (ROS) and increased the total cellular glutathione (tGSH) content. Carbon black also induced ROS generation; however, in contrast to the fly ash, it decreased the intracellular tGSH. The fly ash-induced oxidative stress was correlated with induction of the anti-oxidant enzyme heme oxygenase-1 and increase of the redox-sensitive transcription factor Nrf2. Carbon black was not able to induce HO-1. ROS generation, tGSH increase and HO-1 induction were only induced by the insoluble fraction of the fly ash, not by the water-soluble fraction. ROS generation and HO-1 induction were markedly inhibited by pre-incubation of the cells with the anti-oxidant N-acetyl cysteine which confirmed the involvement of oxidative stress. Both effects were also reduced by the metal chelator deferoxamine indicating a contribution of bioavailable transition metals. In summary, both fly ash and carbon black induce ROS but only fly ash induced an increase of intracellular tGSH and HO-1 production. Bioavailable transition metals in the solid water-insoluble matrix of the fly ash mostly contribute to the effects. (orig.)

  19. Capacitor discharge engineering

    Früngel, Frank B A


    High Speed Pulse Technology, Volume III: Capacitor Discharge Engineering covers the production and practical application of capacitor dischargers for the generation and utilization of high speed pulsed of energy in different forms. This nine-chapter volume discusses the principles of electric current, voltage, X-rays, gamma rays, heat, beams of electrons, neutrons and ions, magnetic fields, sound, and shock waves in gases and liquids. Considerable chapters consider the applications of capacitor discharges, such as impulse hardening of steel, ultrapulse welding of precision parts, X-ray flash t

  20. High Temperature Capacitor Development

    John Kosek


    The absence of high-temperature electronics is an obstacle to the development of untapped energy resources (deep oil, gas and geothermal). US natural gas consumption is projected to grow from 22 trillion cubic feet per year (tcf) in 1999 to 34 tcf in 2020. Cumulatively this is 607 tcf of consumption by 2020, while recoverable reserves using current technology are 177 tcf. A significant portion of this shortfall may be met by tapping deep gas reservoirs. Tapping these reservoirs represents a significant technical challenge. At these depths, temperatures and pressures are very high and may require penetrating very hard rock. Logistics of supporting 6.1 km (20,000 ft) drill strings and the drilling processes are complex and expensive. At these depths up to 50% of the total drilling cost may be in the last 10% of the well depth. Thus, as wells go deeper it is increasingly important that drillers are able to monitor conditions down-hole such as temperature, pressure, heading, etc. Commercial off-the-shelf electronics are not specified to meet these operating conditions. This is due to problems associated with all aspects of the electronics including the resistors and capacitors. With respect to capacitors, increasing temperature often significantly changes capacitance because of the strong temperature dependence of the dielectric constant. Higher temperatures also affect the equivalent series resistance (ESR). High-temperature capacitors usually have low capacitance values because of these dielectric effects and because packages are kept small to prevent mechanical breakage caused by thermal stresses. Electrolytic capacitors do not operate at temperatures above 150oC due to dielectric breakdown. The development of high-temperature capacitors to be used in a high-pressure high-temperature (HPHT) drilling environment was investigated. These capacitors were based on a previously developed high-voltage hybridized capacitor developed at Giner, Inc. in conjunction with a

  1. Electrochemical flow capacitors

    Gogotsi, Yury; Presser, Volker; Kumbur, Emin Caglan


    The present invention generally relates to devices for energy storage technologies, and more particularly to electrochemical flow capacitor systems and applications. In some aspects, these flow capacitors have at least one electrode comprising a non-stationary solid or semi-solid composition comprising supercapacitive particles and an electrolytic solvent in electrical communication with at least one current collector, and energy is stored and/or released by charging and/or discharging the electrode(s).

  2. Fermilab Capacitor Tree

    The Fermilab Capacitor Tree is a capacitor bank used in series with the feeders carrying 3-phase, 13.8 kV power to the main ring power supply system. Its function is to reduce the voltage droop of the power supplies at high currents, by acting in series resonance with the leakage inductances of the system. A description is given of the electrical system and operational experience since May 1976

  3. Suspended graphene variable capacitor

    AbdelGhany, M.; Mahvash, F.; Mukhopadhyay, M.; Favron, A.; Martel, R; Siaj, M.; Szkopek, T.


    The tuning of electrical circuit resonance with a variable capacitor, or varactor, finds wide application with the most important being wireless telecommunication. We demonstrate an electromechanical graphene varactor, a variable capacitor wherein the capacitance is tuned by voltage controlled deflection of a dense array of suspended graphene membranes. The low flexural rigidity of graphene monolayers is exploited to achieve low actuation voltage in an ultra-thin structure. Large arrays compr...

  4. Materials for electrochemical capacitors

    Simon, Patrice; Gogotsi, Yury


    Electrochemical capacitors, also called supercapacitors, store energy using either ion adsorption (electrochemical double layer capacitors) or fast surface redox reactions (pseudo-capacitors). They can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. A notable improvement in performance has been achieved through recent advances in understanding charge storage mechanisms and the development of advanced nanostructured materials. The discovery that ion desolvation occurs in pores smaller than the solvated ions has led to higher capacitance for electrochemical double layer capacitors using carbon electrodes with subnanometre pores, and opened the door to designing high-energy density devices using a variety of electrolytes. Combination of pseudo-capacitive nanomaterials, including oxides, nitrides and polymers, with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries. The use of carbon nanotubes has further advanced micro-electrochemical capacitors, enabling flexible and adaptable devices to be made. Mathematical modelling and simulation will be the key to success in designing tomorrow's high-energy and high-power devices.

  5. Analysis of the distribution of the brain cells of the fruit fly by an automatic cell counting algorithm

    Shimada, Takashi; Kato, Kentaro; Kamikouchi, Azusa; Ito, Kei


    The fruit fly is the smallest brain-having model animal. Its brain is said to consist only of about 250,000 neurons, whereas it shows “the rudiments of consciousness” in addition to its high abilities such as learning and memory. As the starting point of the exhaustive analysis of its brain-circuit information, we have developed a new algorithm of counting cells automatically from source 2D/3D figures. In our algorithm, counting cells is realized by embedding objects (typically, disks/balls), each of which has exclusive volume. Using this method, we have succeeded in counting thousands of cells accurately. This method provides us the information necessary for the analysis of brain circuits: the precise distribution of the whole brain cells.

  6. Single Switched Capacitor Battery Balancing System Enhancements

    Joeri van Mierlo


    Full Text Available Battery management systems (BMS are a key element in electric vehicle energy storage systems. The BMS performs several functions concerning to the battery system, its key task being balancing the battery cells. Battery cell unbalancing hampers electric vehicles’ performance, with differing individual cell voltages decreasing the battery pack capacity and cell lifetime, leading to the eventual failure of the total battery system. Quite a lot of cell balancing topologies have been proposed, such as shunt resistor, shuttling capacitor, inductor/transformer based and DC energy converters. The shuttling capacitor balancing systems in particular have not been subject to much research efforts however, due to their perceived low balancing speed and high cost. This paper tries to fill this gap by briefly discussing the shuttling capacitor cell balancing topologies, focusing on the single switched capacitor (SSC cell balancing and proposing a novel procedure to improve the SSC balancing system performance. This leads to a new control strategy for the SSC system that can decrease the balancing system size, cost, balancing time and that can improve the SSC balancing system efficiency.


    Y.P.B.Yeung; K.W.E.Cheng; K.K.Law


    A family of switched-capacitor based resonant converters is present.All converters are in step-downmode.By adding different number of switched-capacitor cells,different output voltage conversion ratio can beobtained.All switching devices in the converters operate under zero-current switching.Both high frequencyoperations and high efficiency are possible.

  8. Capacitor discharge pulse analysis.

    Baker, Michael Sean; Griffiths, Stewart K.; Tanner, Danelle Mary


    Capacitors used in firing sets and other high discharge current applications are discharge tested to verify performance of the capacitor against the application requirements. Parameters such as capacitance, inductance, rise time, pulse width, peak current and current reversal must be verified to ensure that the capacitor will meet the application needs. This report summarizes an analysis performed on the discharge current data to extract these parameters by fitting a second-order system model to the discharge data and using this fit to determine the resulting performance metrics. Details of the theory and implementation are presented. Using the best-fit second-order system model to extract these metrics results in less sensitivity to noise in the measured data and allows for direct extraction of the total series resistance, inductance, and capacitance.

  9. Engineering electrochemical capacitor applications

    Miller, John R.


    Electrochemical capacitor (EC) applications have broadened tremendously since EC energy storage devices were introduced in 1978. Then typical applications operated below 10 V at power levels below 1 W. Today many EC applications operate at voltages approaching 1000 V at power levels above 100 kW. This paper briefly reviews EC energy storage technology, shows representative applications using EC storage, and describes engineering approaches to design EC storage systems. Comparisons are made among storage systems designed to meet the same application power requirement but using different commercial electrochemical capacitor products.

  10. An Improved Fruit Fly Optimization Algorithm Inspired from Cell Communication Mechanism

    Chuncai Xiao


    Full Text Available Fruit fly optimization algorithm (FOA invented recently is a new swarm intelligence method based on fruit fly’s foraging behaviors and has been shown to be competitive with existing evolutionary algorithms, such as particle swarm optimization (PSO algorithm. However, there are still some disadvantages in the FOA, such as low convergence precision, easily trapped in a local optimum value at the later evolution stage. This paper presents an improved FOA based on the cell communication mechanism (CFOA, by considering the information of the global worst, mean, and best solutions into the search strategy to improve the exploitation. The results from a set of numerical benchmark functions show that the CFOA outperforms the FOA and the PSO in most of the experiments. Further, the CFOA is applied to optimize the controller for preoxidation furnaces in carbon fibers production. Simulation results demonstrate the effectiveness of the CFOA.

  11. High ALDH activity identifies chemotherapy-resistant Ewing's sarcoma stem cells that retain sensitivity to EWS-FLI1 inhibition.

    Ola Awad

    Full Text Available BACKGROUND: Cancer stem cells are a chemotherapy-resistant population capable of self-renewal and of regenerating the bulk tumor, thereby causing relapse and patient death. Ewing's sarcoma, the second most common form of bone tumor in adolescents and young adults, follows a clinical pattern consistent with the Cancer Stem Cell model - remission is easily achieved, even for patients with metastatic disease, but relapse remains frequent and is usually fatal. METHODOLOGY/PRINCIPAL FINDINGS: We have isolated a subpopulation of Ewing's sarcoma cells, from both human cell lines and human xenografts grown in immune deficient mice, which express high aldehyde dehydrogenase (ALDH(high activity and are enriched for clonogenicity, sphere-formation, and tumor initiation. The ALDH(high cells are resistant to chemotherapy in vitro, but this can be overcome by the ATP binding cassette transport protein inhibitor, verapamil. Importantly, these cells are not resistant to YK-4-279, a small molecule inhibitor of EWS-FLI1 that is selectively toxic to Ewing's sarcoma cells both in vitro and in vivo. CONCLUSIONS/SIGNIFICANCE: Ewing's sarcoma contains an ALDH(high stem-like population of chemotherapy-resistant cells that retain sensitivity to EWS-FLI1 inhibition. Inhibiting the EWS-FLI1 oncoprotein may prove to be an effective means of improving patient outcomes by targeting Ewing's sarcoma stem cells that survive standard chemotherapy.

  12. Non-ideal effects of MOS capacitor in a switched capacitor waveform recorder ASIC

    Zhang, Hong-Yan; Deng, Zhi; Liu, Yi-Nong


    SCAs (Switched Capacitor Arrays) have a wide range of uses, especially in high energy physics, nuclear science and astrophysics experiments. This paper presents a method of using a MOS capacitor as a sampling capacitor to gain larger capacitance with small capacitor area in SCA design. It studies the non-ideal effects of the MOS capacitor and comes up with ways to reduce these adverse effects. A prototype SCA ASIC which uses a MOS capacitor to store the samples has been designed and tested to verify this method. The SCA integrates 32 channels and each has 64 cells and a readout amplifier. The stored voltage is converted to a pair of differential currents (±4 mA max) and multiplexed to the output. All the functionalities have been verified. The power consumption is less than 2 mW/ch. The INL of all the cells in one channel are better than 0.39%. The equivalent input noise of the SCA has been tested to be 2.2 mV with 625 kHz full-scale sine wave as input, sampling at 40 MSPS (Mega-samples per Second) and reading out at 5 MHz. The effective resolution is 8.8 bits considering 1 V dynamic range. The maximum sampling rate reaches up to 50 MSPS and readout rate of 15 MHz to keep noise smaller than 2.5 mV. The test results validate the feasibility of the MOS capacitor. Supported by National Natural Science Foundation of China (11375100), Strategic Pioneer Program on Space Sciences, Chinese Academy of Sciences (XDA04060606-06) and State Key Laboratory of Particle Detection and Electronics

  13. FOXO1 is a direct target of EWS-Fli1 oncogenic fusion protein in Ewing's sarcoma cells

    Yang, Liu, E-mail: [Department of Orthopedics, University of Washington, Seattle, WA 98195 (United States); Medical Research Service, VA Puget Sound Health Care System, Seattle, WA 98108 (United States); Hu, Hsien-Ming; Zielinska-Kwiatkowska, Anna; Chansky, Howard A. [Department of Orthopedics, University of Washington, Seattle, WA 98195 (United States); Medical Research Service, VA Puget Sound Health Care System, Seattle, WA 98108 (United States)


    Research highlights: {yields} Inducible and reversible siRNA knockdown of an oncogenic fusion protein such as EWS-Fli1 is feasible and more advantageous than other siRNA methods. {yields} The tumor suppressor gene FOXO1 is a new EWS-Fli1 target. {yields} While trans-activators are known for the FOXO1 gene, there has been no report on negative regulators of FOXO1 transcription. {yields} This study provides first evidence that the EWS-Fli1 oncogenic fusion protein can function as a transcriptional repressor of the FOXO1 gene. -- Abstract: Ewing's family tumors are characterized by a specific t(11;22) chromosomal translocation that results in the formation of EWS-Fli1 oncogenic fusion protein. To investigate the effects of EWS-Fli1 on gene expression, we carried out DNA microarray analysis after specific knockdown of EWS-Fli1 through transfection of synthetic siRNAs. EWS-Fli1 knockdown increased expression of genes such as DKK1 and p57 that are known to be repressed by EWS-Fli1 fusion protein. Among other potential EWS-Fli1 targets identified by our microarray analysis, we have focused on the FOXO1 gene since it encodes a potential tumor suppressor and has not been previously reported in Ewing's cells. To better understand how EWS-Fli1 affects FOXO1 expression, we have established a doxycycline-inducible siRNA system to achieve stable and reversible knockdown of EWS-Fli1 in Ewing's sarcoma cells. Here we show that FOXO1 expression in Ewing's cells has an inverse relationship with EWS-Fli1 protein level, and FOXO1 promoter activity is increased after doxycycline-induced EWS-Fli1 knockdown. In addition, we have found that direct binding of EWS-Fli1 to FOXO1 promoter is attenuated after doxycycline-induced siRNA knockdown of the fusion protein. Together, these results suggest that suppression of FOXO1 function by EWS-Fli1 fusion protein may contribute to cellular transformation in Ewing's family tumors.

  14. BioCapacitor: A novel principle for biosensors.

    Sode, Koji; Yamazaki, Tomohiko; Lee, Inyoung; Hanashi, Takuya; Tsugawa, Wakako


    Studies regarding biofuel cells utilizing biocatalysts such as enzymes and microorganisms as electrocatalysts have been vigorously conducted over the last two decades. Because of their environmental safety and sustainability, biofuel cells are expected to be used as clean power generators. Among several principles of biofuel cells, enzyme fuel cells have attracted significant attention for their use as alternative energy sources for future implantable devices, such as implantable insulin pumps and glucose sensors in artificial pancreas and pacemakers. However, the inherent issue of the biofuel cell principle is the low power of a single biofuel cell. The theoretical voltage of biofuel cells is limited by the redox potential of cofactors and/or mediators employed in the anode and cathode, which are inadequate for operating any devices used for biomedical application. These limitations inspired us to develop a novel biodevice based on an enzyme fuel cell that generates sufficient stable power to operate electric devices, designated "BioCapacitor." To increase voltage, the enzyme fuel cell is connected to a charge pump. To obtain a sufficient power and voltage to operate an electric device, a capacitor is used to store the potential generated by the charge pump. Using the combination of a charge pump and capacitor with an enzyme fuel cell, high voltages with sufficient temporary currents to operate an electric device were generated without changing the design and construction of the enzyme fuel cell. In this review, the BioCapacitor principle is described. The three different representative categories of biodevices employing the BioCapacitor principle are introduced. Further, the recent challenges in the developments of self-powered stand-alone biodevices employing enzyme fuel cells combined with charge pumps and capacitors are introduced. Finally, the future prospects of biodevices employing the BioCapacitor principle are addressed. PMID:26278505

  15. Electrostatic spray deposition based lithium ion capacitor

    Agrawal, Richa; Chen, Chunhui; Wang, Chunlei


    Conventional Electrochemical double-layer capacitors (EDLCs) are well suited as power devices that can provide large bursts of energy in short time periods. However, their relatively inferior energy densities as compared to their secondary battery counterparts limit their application in devices that require simultaneous supply of both high energy and high power. In the wake of addressing this shortcoming of EDLCs, the concept of hybridization of lithium-ion batteries (LIBs) and EDLCs has attracted significant scientific interest in recent years. Such a device, generally referred to as the "lithium-ion capacitor" typically utilizes a lithium intercalating electrode along with a fast charging capacitor electrode. Herein we have constructed a lithium hybrid electrochemical capacitor comprising a Li4Ti5O12-TiO2 (LTO-TiO2) anode and a reduced graphene oxide and carbon nanotube (rGO-CNT) composite cathode using electrostatic spray deposition (ESD). The electrodes were characterized using scanning electron microscopy and X-ray diffraction studies. Cyclic voltammetry and galvanostatic charge-discharge measurements were carried out to evaluate the electrochemical performance of the individual electrodes and the full hybrid cells.

  16. Fuel cells, batteries and super-capacitors stand-alone power systems management using optimal/flatness based-control

    Benaouadj, M.; Aboubou, A.; Ayad, M. Y.; Bahri, M.; Boucetta, A.


    In this work, an optimal control (under constraints) based on the Pontryagin's maximum principle is used to optimally manage energy flows in a basic PEM (Proton Exchange Membrane) fuel cells system associated to lithium-ion batteries and supercapacitors through a common DC bus having a voltage to stabilize using the differential flatness approach. The adaptation of voltage levels between different sources and load is ensured by use of three DC-DC converters, one boost connected to the PEM fuel cells, while the two others are buck/boost and connected to the lithiumion batteries and supercapacitors. The aim of this paper is to develop an energy management strategy that is able to satisfy the following objectives: - Impose the power requested by a habitat (representing the load) according to a proposed daily consumption profile, - Keep fuel cells working at optimal power delivery conditions, - Maintain constant voltage across the common DC bus, - Stabilize the batteries voltage and stored quantity of charge at desired values given by the optimal control.Results obtained under MATLAB/Simulink environment prove that the cited objectives are satisfied, validating then, effectiveness and complementarity between the optimal and flatness concepts proposed for energy management. Note that this study is currently in experimentally validation within MSE Laboratory.

  17. Protection of large capacitor banks

    Large capacitor banks, as used in many pulsed plasma experiments, are subject to catastrophic failure in the event of a short in the output or in an individual capacitor. Methods are described for protecting such banks to minimize the damage and down-time caused by such a failure

  18. Carbon-Based Fibrous EDLC Capacitors and Supercapacitors

    Lekakou, C.; O. Moudam; Markoulidis, F; Andrews, T.; J. F. Watts; Reed, G.T.


    This paper investigates electrochemical double-layer capacitors (EDLCs) including two alternative types of carbon-based fibrous electrodes, a carbon fibre woven fabric (CWF) and a multiwall carbon nanotube (CNT) electrode, as well as hybrid CWF-CNT electrodes. Two types of separator membranes were also considered. An organic gel electrolyte PEO-LiCIO4-EC-THF was used to maintain a high working voltage. The capacitor cells were tested in cyclic voltammetry, charge-discharge, and impedance test...

  19. Electrically tuned super-capacitors

    Chowdhury, Tazima S


    Fast charging and discharging of large amounts of electrical energy make super-capacitors ideal for short-term energy storage [1-5]. In its simplest form, the super-capacitor is an electrolytic capacitor made of an anode and a cathode immersed in an electrolyte. As for an ordinary capacitor, minimizing the charge separation distance and increasing the electrode area increase capacitance. In super-capacitors, charge separation is of nano-meter scale at each of the electrode interface (the Helmholtz double layer). Making the electrodes porous increases their effective surface area [6-8]. A separating layer between the anode and the cathode electrodes is used to minimize unintentional electrical discharge (Figure 1). Here we show how to increase the capacitance of super-capacitors by more than 45 percent when modifying the otherwise passive separator layer into an active diode-like structure. Active control of super-capacitors may increase their efficiency during charge and discharge cycles. Controlling ion flow...

  20. Evaluation and Characterization of Magnets and Capacitors

    Seiber, L.E.; Cunningham, J.P.; Golik, S.S. (ORISE); Armstrong, G. (Maverick Systems)


    Advanced vehicle, fuel cell, hybrid electric vehicle (HEV), and plug in hybrid research and development is conducted by the U.S. Department of Energy (DOE) through its FreedomCAR and Vehicle Technologies (FCVT) program. The mission of this program is to develop more energy efficient and environmentally safe highway transportation technologies. Program activities include research, development, testing, technology validation, and technology transfer. These activities are done at the system and component levels. This report will discuss component level testing of prototype capacitors and magnets. As capacitor and magnet technologies mature, it is important to ascertain the limitations of these new technologies by subjecting the components to standardized tests to evaluate their capabilities. Test results will assist in the determination of their ability to provide improvements in power electronics and motor designs to meet the FCVT goals.

  1. Fractal Structures For Mems Variable Capacitors

    Elshurafa, Amro M.


    In accordance with the present disclosure, one embodiment of a fractal variable capacitor comprises a capacitor body in a microelectromechanical system (MEMS) structure, wherein the capacitor body has an upper first metal plate with a fractal shape separated by a vertical distance from a lower first metal plate with a complementary fractal shape; and a substrate above which the capacitor body is suspended.

  2. Ferroelectric capacitor with reduced imprint

    Evans, Jr., Joseph T. (13609 Verbena Pl., NE., Albuquerque, NM 87112); Warren, William L. (7716 Wm. Moyers Ave., NE., Albuquerque, NM 87122); Tuttle, Bruce A. (12808 Lillian Pl., NE., Albuquerque, NM 87122); Dimos, Duane B. (6105 Innsbrook Ct., NE., Albuquerque, NM 87111); Pike, Gordon E. (1609 Cedar Ridge, NE., Albuquerque, NM 87112)


    An improved ferroelectric capacitor exhibiting reduced imprint effects in comparison to prior art capacitors. A capacitor according to the present invention includes top and bottom electrodes and a ferroelectric layer sandwiched between the top and bottom electrodes, the ferroelectric layer comprising a perovskite structure of the chemical composition ABO.sub.3 wherein the B-site comprises first and second elements and a dopant element that has an oxidation state greater than +4. The concentration of the dopant is sufficient to reduce shifts in the coercive voltage of the capacitor with time. In the preferred embodiment of the present invention, the ferroelectric element comprises Pb in the A-site, and the first and second elements are Zr and Ti, respectively. The preferred dopant is chosen from the group consisting of Niobium, Tantalum, and Tungsten. In the preferred embodiment of the present invention, the dopant occupies between 1 and 8% of the B-sites.

  3. High Energy Density Capacitors Project

    National Aeronautics and Space Administration — Capacitor size and reliability are often limiting factors in pulse power, high speed switching, and power management and distribution (PMAD) systems. T/J...

  4. CRM1 Inhibition Promotes Cytotoxicity in Ewing Sarcoma Cells by Repressing EWS-FLI1-Dependent IGF-1 Signaling.

    Sun, Haibo; Lin, De-Chen; Cao, Qi; Guo, Xiao; Marijon, Helene; Zhao, Zhiqiang; Gery, Sigal; Xu, Liang; Yang, Henry; Pang, Brendan; Lee, Victor Kwan Min; Lim, Huey Jin; Doan, Ngan; Said, Jonathan W; Chu, Peiguo; Mayakonda, Anand; Thomas, Tom; Forscher, Charles; Baloglu, Erkan; Shacham, Sharon; Rajalingam, Raja; Koeffler, H Phillip


    Ewing sarcoma (EWS) is an aggressive bone malignancy that mainly affects children and young adults. The mechanisms by which EWS (EWSR1) fusion genes drive the disease are not fully understood. CRM1 (XPO1) traffics proteins from the nucleus, including tumor suppressors and growth factors, and is overexpressed in many cancers. A small-molecule inhibitor of CRM1, KPT-330, has shown therapeutic promise, but has yet to be investigated in the context of EWS. In this study, we demonstrate that CRM1 is also highly expressed in EWS. shRNA-mediated or pharmacologic inhibition of CRM1 in EWS cells dramatically decreased cell growth while inducing apoptosis, cell-cycle arrest, and protein expression alterations to several cancer-related factors. Interestingly, silencing of CRM1 markedly reduced EWS-FLI1 fusion protein expression at the posttranscriptional level and upregulated the expression of the well-established EWS-FLI1 target gene, insulin-like growth factor binding protein 3 (IGFBP3), which inhibits IGF-1. Accordingly, KPT-330 treatment attenuated IGF-1-induced activation of the IGF-1R/AKT pathway. Furthermore, knockdown of IGFBP3 increased cell growth and rescued the inhibitory effects on IGF-1 signaling triggered by CRM1 inhibition. Finally, treatment of EWS cells with a combination of KPT-330 and the IGF-1R inhibitor, linsitinib, synergistically decreased cell proliferation both in vitro and in vivo Taken together, these findings provide a strong rationale for investigating the efficacy of combinatorial inhibition of CRM1 and IGF-1R for the treatment of EWS. Cancer Res; 76(9); 2687-97. ©2016 AACR. PMID:26956669

  5. Fractal Structures For Fixed Mems Capacitors

    Elshurafa, Amro M.


    An embodiment of a fractal fixed capacitor comprises a capacitor body in a microelectromechanical system (MEMS) structure. The capacitor body has a first plate with a fractal shape separated by a horizontal distance from a second plate with a fractal shape. The first plate and the second plate are within the same plane. Such a fractal fixed capacitor further comprises a substrate above which the capacitor body is positioned.

  6. Radiation effects in polycarbonate capacitors

    Vujisić Miloš


    Full Text Available The aim of this paper is to examine the influence of neutron and gamma irradiation on the dissipation factor and capacitance of capacitors with polycarbonate dielectrics. The operation of capacitors subject to extreme conditions, such as the presence of ionizing radiation fields, is of special concern in military industry and space technology. Results obtained show that the exposure to a mixed neutron and gamma radiation field causes a decrease of capacitance, while the loss tangent remains unchanged.

  7. PLZT capacitor on glass substrate

    Fairchild, Manuel Ray; Taylor, Ralph S.; Berlin, Carl W.; Wong, Celine Wk; Ma, Beihai; Balachandran, Uthamalingam


    A lead-lanthanum-zirconium-titanate (PLZT) capacitor on a substrate formed of glass. The first metallization layer is deposited on a top side of the substrate to form a first electrode. The dielectric layer of PLZT is deposited over the first metallization layer. The second metallization layer deposited over the dielectric layer to form a second electrode. The glass substrate is advantageous as glass is compatible with an annealing process used to form the capacitor.

  8. Microwatt Switched Capacitor Circuit Design

    Vittoz, E.


    The micropower CMOS implementation of the three basic components of switched capacitor circuits is discussed. Switches must be carefully designed to allow low voltage operation and compensation of clock feed-through by dummy transistors. Matched capacitors can be implemented in single polysilicon technologies primarily designed for digital micropower circuits. Excellent micropower amplifiers are realized by using simple one-stage circuits which take advantage of the special behaviour of MOS t...

  9. Efficiency Improvement of Capacitor Operation

    V. P. Kashcheev


    Full Text Available A system of modernized capacitor ball-cleaning that prevents formation of depositions on internal capacitor tube surface has been developed in the paper.The system has been introduced at the Minsk TPP-4 (Power Block No.5. The paper presupposes that the economic effect will be nearly 0.43 million US dollars per year at one poer block with turbine Т-250/300-240.

  10. Technology of Pulse Power Capacitors

    Qin, Shanshan

    Polymer film of pulse discharge capacitors operated at high repetition rate dissipates substantial power. The thermal conductivity of biaxially oriented polypropylene (BOPP) is measured as a function of metallization resistivity. The thermal conductivity in the plane of the film is about twice that of bulk polypropylene. Thermal design is optimized based on the measurement for large capacitors with multiple windings in a container. High discharge speed results in high current density at the wire arc sprayed end connections which tend to deteriorate gradually, resulting in capacitor failure during operation. To assure the end connection quality before assembly, a test procedure and apparatus for end connection integrity was developed based on monitoring the partial discharge pattern from end connection during discharge. The mechanism of clearing is analyzed which shows arc extinguishes due to the increased arc length and reduced energy so that capacitor can function normally after breakdown. In the case of a clearing discharge, the power dissipation appears to increase with time, although this is not a feature of previous models. Submicrosecond discharge requires minimizing inductance which can be achieved by optimizing the winding structure so that submicrosecond discharge becomes practical. An analysis of the inductance of multisection, very high voltage capacitors is carried out, which identifies low inductance structures for this type of capacitor.

  11. Screening and identification of a novel target specific for hepatoma cell line HepG2 from the FliTrx bacterial peptide library

    Wenhan Li; Ping Lei; Bing Yu; Sha Wu; Jilin Peng; Xiaoping Zhao; Huffen Zhu; Michael Kirschfink; Guanxin Shen


    To explore new targets for hepatoma research, we used a surface display library to screen novel tumor cell-specific peptides. The bacterial FliTrx system was screened with living normal liver cell line L02 and hepatoma cell line HepG2 successively to search for hepatoma-specific peptides. Three clones (Hep1, Hep2, and Hep3) were identified to be specific to HepG2 compared with L02 and other cancer cell lines.Three-dimensional structural prediction proved that peptides inserted into the active site of Escherichia coli thioredoxin (TrxA) formed certain loop structures protruding out of the surface. Western blot analysis showed that FliC/TrxA-pepfide fusion proteins could be directly used to detect HepG2 cells.Three different FliC/TrxA-peptide fusion proteins targeted the same molecule, at approximately 140 kDa, on HepG2 cells.This work presented for the first time the application of the FliTrx library in screening living cells. Three peptides were obtained that could be potential candidates for targeted liver cancer therapy.

  12. Real-Time Cell-Electronic Sensing of Coal Fly Ash Particulate Matter for Toxicity-Based Air Quality Monitoring.

    Moe, Birget; Yuan, Chungang; Li, Jinhua; Du, Haiying; Gabos, Stephan; Le, X Chris; Li, Xing-Fang


    The development of a unique bioassay for cytotoxicity analysis of coal fly ash (CFA) particulate matter (PM) and its potential application for air quality monitoring is described. Using human cell lines, A549 and SK-MES-1, as live probes on microelectrode-embedded 96-well sensors, impedance changes over time are measured as cells are treated with varying concentrations (1 μg/mL-20 mg/mL) of CFA samples. A dose-dependent impedance change is determined for each CFA sample, from which an IC50 histogram is obtained. The assay was successfully applied to examine CFA samples collected from three coal-fired power plants (CFPs) in China. The samples were separated into three size fractions: PM2.5 (10 μm). Dynamic cell-response profiles and temporal IC50 histograms of all samples show that CFA cytotoxicity depends on concentration, exposure time (0-60 h), and cell-type (SK-MES-1 > A549). The IC50 values differentiate the cytotoxicity of CFA samples based on size fraction (PM2.5 ≈ PM10-2.5 ≫ PM10) and the sampling location (CFP2 > CFP1 ≈ CFP3). Differential cytotoxicity measurements of particulates in human cell lines using cell-electronic sensing provide a useful tool for toxicity-based air quality monitoring and risk assessment. PMID:27124590

  13. High-Energy-Density Capacitors

    Slenes, Kirk


    Capacitors capable of storing energy at high densities are being developed for use in pulse-power circuits in such diverse systems as defibrillators, particle- beam accelerators, microwave sources, and weapons. Like typical previously developed energy-storage capacitors, these capacitors are made from pairs of metal/solid-dielectric laminated sheets that are wound and pressed into compact shapes to fit into cans, which are then filled with dielectric fluids. Indeed, these capacitors can be fabricated largely by conventional fabrication techniques. The main features that distinguish these capacitors from previously developed ones are improvements in (1) the selection of laminate materials, (2) the fabrication of the laminated sheets from these materials, and (3) the selection of dielectric fluids. In simplest terms, a high-performance laminated sheet of the type used in these capacitors is made by casting a dielectric polymer onto a sheet of aluminized kraft paper. The dielectric polymer is a siloxane polymer that has been modified with polar pendant groups to increase its permittivity and dielectric strength. Potentially, this polymer is capable of withstanding an energy density of 7.5 J/cm3, which is four times that of the previous state-of-the-art-capacitor dielectric film material. However, the full potential of this polymer cannot be realized at present because (1) at thicknesses needed for optimum performance (.8.0 m), the mechanical strength of a film of this polymer is insufficient for incorporation into a wound capacitor and (2) at greater thickness, the achievable energy density decreases because of a logarithmic decrease in dielectric strength with increasing thickness. The aluminized kraft paper provides the mechanical strength needed for processing of the laminate and fabrication of the capacitor, and the aluminum film serves as an electrode layer. Because part of the thickness of the dielectric is not occupied by the modified siloxane polymer, the

  14. Electromechanical capacitor for energy transfer

    Inductive energy transfer between two magnets can be achieved with almost 100% efficiency with a transfer capacitor. However, the bulk and cost will be high, and reliability low if conventional capacitors are used. A homopolar machine, used as a capacitor, will be compact and economical. A homopolar machine was designed with counter-rotating copper disks completely immersed in a liquid metal (NaK-78) to work as a pulse capacitor. Absence of solid-brush collectors minimized wear and frictional losses. Wetting of the copper disks throughout the periphery by the liquid metal minimized the resistive losses at the collector interface. A liquid-metal collector would, however, introduce hydrodynamic and magnetohydrodynamic losses. The selected liquid metal, e.g., NaK-78 will produce the lowest of such losses among the available liquid metals. An electromechanical capacitor of this design was tested at various dc magnetic fields. Its measured capacitance was about 100 farads at a dc magnetic field of 1.15 tesla

  15. Tunable circuit for tunable capacitor devices

    Rivkina, Tatiana; Ginley, David S.


    A tunable circuit (10) for a capacitively tunable capacitor device (12) is provided. The tunable circuit (10) comprises a tunable circuit element (14) and a non-tunable dielectric element (16) coupled to the tunable circuit element (16). A tunable capacitor device (12) and a method for increasing the figure of merit in a tunable capacitor device (12) are also provided.

  16. Electrical characterization of thin film ferroelectric capacitors

    Tiggelman, M.P.J.; Reimann, K.; Klee, M.; Beelen, D.; Keur, W.; Schmitz, J.; Hueting, R.J.E.


    Tunable capacitors can be used to facilitate the reduction of components in wireless technologies. The tunability of the capacitors is caused by the sensitivity of the relative dielectric constant to a change in polarization with electric field. Thin film ferroelectric MIM capacitors on silicon offe

  17. Time flies

    Wit, Janneke

    The red thread of this dissertation is ageing, or life span, of Drosophila melanogaster. Because D. melanogaster is a model organism of which many basic molecular mechanisms are conserved in humans, studying ageing and its effects on a suite of functions in this organism helps to understand ageing...... result, the LS fly might be able to spend energy more generously on different tasks. Therefor, the capacity of LS and C lines to locate resources in a natural environment was tested. It turns out that LS flies are less likely to find food than C flies in such a setting, yet that as they age, their......, regardless of mating status. Generalising studies on ageing in D. melanogaster can be cumbersome, especially in light of discrepancy between correlated responses between studies. To elucidate which mechanisms might be conserved due to evolutionary constraints, life span of 13 species of Drosophila was...

  18. Flying Scared

    Dal Sie, Marco; Josiassen, Alexander

    In light of the burgeoning growth of long-haul LCCs in Southeast Asia, the study constructs a model aimed at comprehending which factors lead passengers to choose full-service rather than no-frills carriers on long-range flights. In particular, the research aims at determining to what extent...... service quality expectations and fear of flying affect travellers' flight choices on long-haul flights. The study was set in Bangkok and primary data were obtained from a large sample of travelers departing from Suvarnabhumi Airport. While service quality emerged as a relevant factor, fear of flying didn...

  19. Flying Cities

    Herbelin, Bruno; Lasserre, Sebastien; Ciger, Jan


    Flying Cities is an artistic installation which generates imaginary cities from the speech of its visitors. Thanks to an original interactive process analyzing people's vocal input to create 3D graphics, a tangible correspondence between speech and visuals opens new possibilities of interaction....... This cross-modal interaction not only supports our artistic messages, but also aims at providing anyone with a pleasant and stimulating feedback from her/his speech activity. As the feedback we have received when presenting Flying Cities was very positive, our objective is now to cross the bridge...

  20. Heat generation in double layer capacitors

    Schiffer, Julia; Linzen, Dirk; Sauer, Dirk Uwe [Electrochemical Energy Conversion and Storage Systems Group, Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University, Jaegerstrasse 17-19, D-52066 Aachen (Germany)


    Thermal management is a key issue concerning lifetime and performance of double layer capacitors and battery technologies. Double layer capacitor modules for hybrid vehicles are subject to heavy duty cycling conditions and therefore significant heat generation occurs. High temperature causes accelerated aging of the double layer capacitors and hence reduced lifetime. To investigate the thermal behavior of double layer capacitors, thermal measurements during charge/discharge cycles were performed. These measurements show that heat generation in double layer capacitors is the superposition of an irreversible Joule heat generation and a reversible heat generation caused by a change in entropy. A mathematical representation of both parts is provided. (author)

  1. Flying spot en-face OCT for monitoring cell distribution in collagen-based constructs

    Kosmidis, Konstantinos; Russell, Christopher D.; Black, Richard A.; Dobre, George; Podoleanu, Adrian Gh.


    The use of optical coherence tomography (OCT) as a monitoring tool in the growth of human fibroblasts cells in collagen-based constructs is investigated. Rat-tail tendon type-1 collagen based gels mixed with human fibroblasts were prepared and incubated. Fixed samples were then imaged using OCT, and subsequently cross-sectioned and analysed microscopically. The concentration of cells in samples under different contraction dynamics was investigated using analysis of the OCT images. Results show clear differences in scattering intensity as a consequence of cell concentration in both OCT images and micrographs.

  2. Capacitor ageing in electronic devices

    Richard B. N. Vital; Tatiane M. Vital


    The moment when an electronic component doesn’t work like requirements, previously established is a task that need to be considered since began of a system design. However, the use of different technologies, operating under several environmental conditions, makes a component choice a complex step in system design. This paper analyzes the effects that ageing phenomenon of capacitors may introduce in electronic devices operation. For this reason, reliability concepts, processes and ...


    Trunev A. P.


    Full Text Available The article presents a project of the capacitor in the Yang-Mills theory. Model capacitor represents the equipotential surfaces separated by a space. To describe the mechanism of condensation chromodynamics field used numerical models developed based on an average of the Yang-Mills theory. In the present study, we used eight-scalar component model that in the linear case is divided into two groups containing three or five fields respectively. In contrast to classical electrodynamics, a static model of the Yang-Mills is not divided into independent equations because of the nonlinearity of the model itself. However, in the case of a linear theory separation is possible. It is shown that in this particular case, the Yang-Mills theory is reduced to Poisson theory, which describes the electrostatic and magnetostatic phenomena. In the present work it is shown that in a certain region of the parameters of the capacitor of the Yang-Mills theory on the functional properties of the charge accumulation and retention of the field is similar to the capacitor of the electrostatic field or a magnet in magnetostatics. This means that in nature there are two types of charges, which are sources of macroscopic Yang-Mills field, which are similar to the properties of electric and magnetic charges in the Poisson theory. It is shown that in Yang-Mills only one type of charge may be associated with the distribution density of the substance, while another type of charge depends on the charge distribution of the first type. This allows us to provide an explanation for the lack of symmetry between electric and magnetic charges

  4. High Speed Capacitor-Inverter Based Carbon Nanotube Full Adder

    Rashtian M; Khatir A; Keshavarzian P; Navi K; Hashemipour O


    Abstract Carbon Nanotube filed-effect transistor (CNFET) is one of the promising alternatives to the MOS transistors. The geometry-dependent threshold voltage is one of the CNFET characteristics, which is used in the proposed Full Adder cell. In this paper, we present a high speed Full Adder cell using CNFETs based on majority-not (Minority) function. Presented design uses eight transistors and eight capacitors. Simulation results show significant improvement in terms of delay and power-delay...

  5. Charging Capacitors According to Maxwell's Equations: Impossible

    Funaro, Daniele


    The charge of an ideal parallel capacitor leads to the resolution of the wave equation for the electric field with prescribed initial conditions and boundary constraints. Independently of the capacitor's shape and the applied voltage, none of the corresponding solutions is compatible with the full set of Maxwell's equations. The paradoxical situation persists even by weakening boundary conditions, resulting in the impossibility to describe a trivial phenomenon such as the capacitor's charging process, by means of the standard Maxwellian theory.

  6. Charging Capacitors According to Maxwell's Equations: Impossible

    Funaro, Daniele


    The charge of an ideal parallel capacitor leads to the resolution of the wave equation for the electric field with prescribed initial conditions and boundary constraints. Independently of the capacitor's shape and the applied voltage, none of the corresponding solutions is compatible with the full set of Maxwell's equations. The paradoxical situation persists even by weakening boundary conditions, resulting in the impossibility to describe a trivial phenomenon such as the capacitor's charging...

  7. Electrical characterization of thin film ferroelectric capacitors

    Tiggelman, M.P.J.; Reimann, K.; Klee, M.; Beelen, D; Keur, W.; J. Schmitz; Hueting, R.J.E.


    Tunable capacitors can be used to facilitate the reduction of components in wireless technologies. The tunability of the capacitors is caused by the sensitivity of the relative dielectric constant to a change in polarization with electric field. Thin film ferroelectric MIM capacitors on silicon offer a re-use of electronic circuitry, low tuning voltages, a high capacitance density, a low cost, a presence of bulk acoustic wave resonance(s) and decoupling functionality. The basic operation and ...

  8. Nanostructured Electrode Materials for Electrochemical Capacitor Applications

    Hojin Choi; Hyeonseok Yoon


    The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, t...

  9. Capacitor discharges, magnetohydrodynamics, X-rays, ultrasonics

    Früngel, Frank B A


    High Speed Pulse Technology, Volume 1: Capacitor Discharges - Magnetohydrodynamics - X-Rays - Ultrasonics deals with the theoretical and engineering problems that arise in the capacitor discharge technique.This book discusses the characteristics of dielectric material, symmetrical switch tubes with mercury filling, and compensation conductor forms. The transformed discharge for highest current peaks, ignition transformer for internal combustion engines, and X-ray irradiation of subjects in mechanical motion are also elaborated. This text likewise covers the transformed capacitor discharge in w

  10. New Niobium Capacitors with Stable Electrical Parameters

    Lohwasser, W.; M. Stenzel; Zillgen, H.


    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 pr...

  11. Capacitor with a composite carbon foam electrode

    Mayer, S.T.; Pekala, R.W.; Kaschmitter, J.L.


    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy. 1 fig.

  12. Capacitor with a composite carbon foam electrode

    Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Kaschmitter, James L. (Pleasanton, CA)


    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid partides being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy.

  13. Flying Cities

    Ciger, Jan


    of providing a tangible correspondence between the two spaces. This interaction mean has proved to suit the artistic expression well but it also aims at providing anyone with a pleasant and stimulating feedback from speech activity, a new medium for creativity and a way to visually perceive a vocal...... performance. As the feedback we have received when presenting Flying Cities was very positive, our objective now is to cross the bridge between art and the potential applications to the rehabilitation of people with reduced mobility or for the treatment of language impairments....

  14. Capacitor ageing in electronic devices

    Richard B. N. Vital


    Full Text Available The moment when an electronic component doesn’t work like requirements, previously established is a task that need to be considered since began of a system design. However, the use of different technologies, operating under several environmental conditions, makes a component choice a complex step in system design. This paper analyzes the effects that ageing phenomenon of capacitors may introduce in electronic devices operation. For this reason, reliability concepts, processes and mechanism of degradation are presented. Additionally, some mathematical models are presented to assist maintenance activities or component replacement. The presented approach compares the operability of intact and aged components.

  15. New Temperature-Insensitive Electronically-Tunable Grounded Capacitor Simulator

    Muhammad Haroon Khan; Muhammad Taher Abuelma'atti


    A new circuit for simulating a grounded capacitor is presented. The circuit uses one operationalamplifier (OA), three operational-transconductance amplifiers (OTAs), and one capacitor. The realized capacitor is temperature-insensitive and electronically tunable. Experimental results are included.

  16. Characterization of coal fly ash nanoparticles and induced oxidative DNA damage in human peripheral blood mononuclear cells

    Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A. [Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Ali, Al-Yousef Sulaiman [Department of Medical Laboratory Sciences, College of Applied Medical Science, University of Dammam, P.O. Box 1683, Hafr Al Batin-31991 (Saudi Arabia); Musarrat, Javed, E-mail: [Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Department of Agricultural Microbiology, Faculty of Agricultural Sciences, AMU, Aligarh202002 (India)


    The nano-sized particles present in coal fly ash (CFA) were characterized through the X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analyses. The XRD data revealed the average crystallite size of the CFA nanoparticles (CFA-NPs) as 14 nm. TEM and SEM imaging demonstrated predominantly spherical and some polymorphic structures in the size range of 11 to 25 nm. The amount of heavy metal associated with CFA particles ({mu}g/g) were determined as Fe (34160.0 {+-} 1.38), Ni (150.8 {+-} 0.78), Cu (99.3 {+-} 0.56) and Cr (64.0 {+-} 0.86). However, the bioavailability of heavy metals in terms of percent release was in the order as Cr > Ni > Cu > Fe in CFA-dimethyl sulfoxide (DMSO) extract. The comet and cytokinesis blocked micronucleus (CBMN) assays revealed substantial genomic DNA damage in peripheral blood mononuclear (PBMN) cells treated with CFA-NPs in Aq and DMSO extracts. About 1.8 and 3.6 strand breaks per unit of DNA were estimated through alkaline unwinding assay at 1:100 DNA nucleotide/CFA ppm ratios with the Aq and DMSO extracts, respectively. The DNA and mitochondrial damage was invariably greater with CFA-DMSO extract vis-a-vis -Aq extract. Generation of superoxide anions (O{sub 2} Bullet {sup -}) and intracellular reactive oxygen species (ROS) through metal redox-cycling, alteration in mitochondrial potential and 8-oxodG production elucidated CFA-NPs induced oxidative stress as a plausible mechanism for CFA-induced genotoxicity. -- Highlights: Black-Right-Pointing-Pointer CFA consists of spherical crystalline nanoparticles in size range of 11-25 nm. Black-Right-Pointing-Pointer Alkaline unwinding assay revealed single-strandedness in CFA treated ctDNA. Black-Right-Pointing-Pointer CFA nanoparticles exhibited the ability to induce ROS and oxidative DNA damage. Black-Right-Pointing-Pointer Comet and CBMN assays revealed DNA and chromosomal

  17. Ultra-thin multilayer capacitors.

    Renk, Timothy Jerome; Monson, Todd C.


    The fabrication of ultra-thin lanthanum-doped lead zirconium titanate (PLZT) multilayer ceramic capacitors (MLCCs) using a high-power pulsed ion beam was studied. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The goal of this work was to increase the energy density of ceramic capacitors through the formation of a multilayer device with excellent materials properties, dielectric constant, and standoff voltage. For successful device construction, there are a number of challenging requirements including achieving correct stoichiometric and crystallographic composition of the deposited PLZT, as well as the creation of a defect free homogenous film. This report details some success in satisfying these requirements, although 900 C temperatures were necessary for PLZT perovskite phase formation. These temperatures were applied to a previously deposited multi-layer film which was then post-annealed to this temperature. The film exhibited mechanical distress attributable to differences in the coefficient of thermal expansion (CTE) of the various layers. This caused significant defects in the deposited films that led to shorts across devices. A follow-on single layer deposition without post-anneal produced smooth layers with good interface behavior, but without the perovskite phase formation. These issues will need to be addressed in order for ion beam deposited MLCCs to become a viable technology. It is possible that future in-situ heating during deposition may address both the CTE issue, and result in lowered processing temperatures, which in turn could raise the probability of successful MLCC formation.

  18. Pyrrole-Based Conductive Polymers For Capacitors

    Nagasubramanian, Ganesan; Di Stefano, Salvador


    Polypyrrole films containing various dopant anions exhibit superior capacitance characteristics. Used with nonaqueous electrolytes. Candidate for use in advanced electrochemical double-layer capacitors capable of storing electrical energy at high densities. Capacitors made of these films used in automobiles and pulsed power supplies.

  19. Fabrication and Electrochemical Properties of Carbon Nanotube-based Composite Electrodes for Electrochemical Capacitor Applications

    Kwang; Bum; Kim


    1 Results Electrochemical capacitors (ECs) are expected to be used in hybrid electric vehicles in combination with batteries or fuel cells because of their higher power density than batteries. ECs using electrical double layer capacitance of carbon based materials and pseudocapacitance of transition metal oxides are called electrochemical double layer capacitors (EDLC) and supercapacitors (or pseudocapacitor), respectively. Transition metal oxides are considered the best candidates for high energy dens...

  20. Nanostructured Electrode Materials for Electrochemical Capacitor Applications

    Hojin Choi


    Full Text Available The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, the latest trends in electrochemical capacitor research are also discussed through extensive analysis of the literature and by highlighting notable research examples (published mostly since 2013. Finally, a perspective on next-generation capacitor technology is also given, including the challenges that lie ahead.

  1. Modular thyristor controlled series capacitor control system

    Clark, K.; Larsen, E.V.; Wegner, C.A.; Piwko, R.J.


    A modular thyristor controlled series capacitor (TCSC) system, including a method and apparatus, uses phase controlled firing based on monitored capacitor voltage and line current. For vernier operation, the TCSC system predicts an upcoming firing angle for switching a thyristor controlled commutating circuit to bypass line current around a series capacitor. Each bypass current pulse changes the capacitor voltage proportionally to the integrated value of the current pulse. The TCSC system promptly responds to an offset command from a higher-level controller to control bypass thyristor duty to minimize thyristor damage, and to prevent capacitor voltage drift during line current disturbances. In a multi-module TCSC system, the higher level controller accommodates competing objectives of various system demands, including minimizing losses in scheduling control, stabilizing transients, damping subsynchronous resonance (SSR) oscillations, damping direct current (DC) offset, and damping power-swings. 67 figs.

  2. Creating a Buzz about Macrophages: The Fly as an In Vivo Model for Studying Immune Cell Behavior.

    Weavers, Helen; Wood, Will


    Drosophila macrophages exhibit functional parallels with their vertebrate counterparts in both their early developmental roles and later diverse roles in health and disease. This, together with the fly's genetic tractability and opportunities for live imaging, has recently established Drosophila as a powerful model to study macrophage behavior in vivo. PMID:27459064

  3. Contribution to dimensioning a pack of super-capacitors for 12/42 V application

    Rafik, F.; Karmous, M. [Ecole d' Ingenieurs de l' Arc Jurassien, CH (Switzerland); Gualous, H.; Berthon, A. [Universite de Franche-Comte, Lab. en Electronique, Electrotechnique et Systemes (L2ES), UTBM, 90 - Belfort (France); Gallay, R. [Maxwell Technologies, CH (Switzerland)


    Increase power demands on automotive are making current 12/14 V electrical systems inadequate. The total power demand will triple in some cars from 800 W today to an average of 2500 W and into kW range for peak demand in the future. Super-capacitor can be used for energy storage and for peak power requirement in order to increase the efficiency and the life cycle of the system. However, the sizing of energy storage with super-capacitors is very important for embedded applications, because of the weight and the volume of the system. This paper presents a sizing method of a pack of super-capacitors. The proposed method is based on the power and energy demand. In order to validate this method, a model of the Maxwell cell BCAP0010 of super-capacitors is presented and implemented in the SIMPLORER software. (authors)

  4. High Speed Capacitor-Inverter Based Carbon Nanotube Full Adder

    Rashtian M


    Full Text Available Abstract Carbon Nanotube filed-effect transistor (CNFET is one of the promising alternatives to the MOS transistors. The geometry-dependent threshold voltage is one of the CNFET characteristics, which is used in the proposed Full Adder cell. In this paper, we present a high speed Full Adder cell using CNFETs based on majority-not (Minority function. Presented design uses eight transistors and eight capacitors. Simulation results show significant improvement in terms of delay and power-delay product in comparison to contemporary CNFET Adder Cells. Simulations were carried out using HSPICE based on CNFET model with 0.6 V VDD.

  5. Gas evolution in aluminum electrolytic capacitors

    Gomez-Aleixandre, C.; Albella, J.M.; Martinez-Duart, J.M.


    Gas evolution in aluminum electrolytic capacitors constitutes one of their main drawbacks in comparison to other types of capacitors lacking a liquid electrolyte. In this respect, one of the most common causes of failure shown by liquid electrolyte capacitors is electrolyte leakage through the seal or even explosions produced by internal pressure buildup. In order to prevent these hazards, some substances, known as depolarizers, are usually added to the capacitor electrolyte with the purpose of absorbing the hydrogen evolved at the cathode (1, 2). Although the gas evolution problem in electrolytic capacitors has been known for a long time, there is a lack of literature on both direct measurements of the gas evolved and assessments of the amount of depolarizer active for the hydrogen absorption process. Aluminum electrolytic capacitors of and 40V nominal voltage, miniature type (diam 8 mm, height 18.5 mm), were manufactured under standard specifications. The capacitors were filled with about 0.5 ml of an electrolyte consisting essentially of a solution of boric, adipic, and phosphoric acids in ethylene glycol. Picric acid and p-benzoquinone in molar concentrations of 0.01M and 0.05M, respectively, were added as depolarizers, yielding an electrolyte with a resistivity of about 80 ..cap omega..-cm and a pH of 5.1. The pressure inside the capacitors was monitored by a conventional Ushaped manometer made from a capillary glass tube filled with distilled water. The number of mols of gas generated in the capacitor (/eta/ /SUB g/ ) was calculated from the measured pressure (sensitivity 0.1 mm Hg) and the value of the internal volume of the manometercapacitor system.

  6. The eradication of the Mexico killing fly

    In Mexico an industrial facility produces millions of sterile flies. These flies are then released in the wild to eliminate the 'Cochliomyia hominivorax' flu species whose larvae generate large sanitary and economical damage. The flies are made sterile through gamma irradiation at the cocoon stage. Containers filled with 40.000 cocoons are exposed to Cs137 gamma radiation doses of 55 Gy, the irradiation session lasts 2 minutes and a half. After the cocoons undergo strict quality control they are deposited in natural places. The irradiation generates cell damages in semen and ovaries while preserving the capacity of copulating and the lifetime of the flies. (A.C.)

  7. Carbon-Based Fibrous EDLC Capacitors and Supercapacitors

    C. Lekakou


    Full Text Available This paper investigates electrochemical double-layer capacitors (EDLCs including two alternative types of carbon-based fibrous electrodes, a carbon fibre woven fabric (CWF and a multiwall carbon nanotube (CNT electrode, as well as hybrid CWF-CNT electrodes. Two types of separator membranes were also considered. An organic gel electrolyte PEO-LiCIO4-EC-THF was used to maintain a high working voltage. The capacitor cells were tested in cyclic voltammetry, charge-discharge, and impedance tests. The best separator was a glass fibre-fine pore filter. The carbon woven fabric electrode and the corresponding supercapacitor exhibited superior performance per unit area, whereas the multiwall carbon nanotube electrode and corresponding supercapacitor demonstrated excellent specific properties. The hybrid CWF-CNT electrodes did not show a combined improved performance due to the lack of carbon nanotube penetration into the carbon fibre fabric.

  8. Alkaline Capacitors Based on Nitride Nanoparticles

    Aldissi, Matt


    High-energy-density alkaline electrochemical capacitors based on electrodes made of transition-metal nitride nanoparticles are undergoing development. Transition- metal nitrides (in particular, Fe3N and TiN) offer a desirable combination of high electrical conductivity and electrochemical stability in aqueous alkaline electrolytes like KOH. The high energy densities of these capacitors are attributable mainly to their high capacitance densities, which, in turn, are attributable mainly to the large specific surface areas of the electrode nanoparticles. Capacitors of this type could be useful as energy-storage components in such diverse equipment as digital communication systems, implanted medical devices, computers, portable consumer electronic devices, and electric vehicles.

  9. Recent series capacitor applications in North America

    Miske, S.A.; Lang, R.J.; Rowe, S.D. [Canadian General Electric Co. Ltd., Toronto, ON (Canada); Bilodeau, P.; Granger, M. [Hydro-Quebec, Montreal, PQ (Canada)


    Equipment used in three recent installations of series capacitors were reported on. Each set of equipment was designed to serve markedly different objectives. The first design discussed was that of the twelve series capacitor banks installed on the Hydro-Quebec 735 kV transmission system as part of a program to increase the system reliability of the power flow from James Bay to Montreal. The second was the unique series capacitors installed on the Hydro-Quebec 735 kV and 315 kV transmission systems solely for the purpose of blocking direct current. The third design discussed was the world`s first and only EHV three-phase multi-module thyristor-controlled series capacitor (TCSC) installed at the 500 kV Slatt Substation of the Bonneville Power Administration. This project has demonstrated the impressive power system swing and subsynchronous resonance damping capabilities of this technology. 3 refs., 15 figs.

  10. Flying insects and Campylobacter

    Hald, Birthe; Sommer, Helle Mølgaard; Skovgård, Henrik

    Campylobacter in flies Flies of the Muscidae family forage on all kind of faeces – various fly species have different preferences. M domestica prefer pigs, horses and cattle faeces, animals which are all known to frequently excrete Campylobacter. As a result, the insects pick up pathogenic micro...... organisms, which may collect on their bodies or survive passage through the fly gut. Campylobacter and other pathogens are then easily transferred to other surfaces, for instance peoples food – or to broiler houses where they may be swallowed by chickens or contaminate the environment. On a large material...... of several species of flies collected outside broiler houses, merely ~1% of the flies were found Campylobacter positive. However, the prevalence varied considerably with fly species, time of the year, and availability of Campylobacter sources. Influx of flies to broiler houses As the influx of flies...

  11. Development of self-healing capacitors for klystron modulators

    In order to realize a compact pulse modulator for klystron, a reliable capacitor with a long lifetime is required. We have evaluated lifetime performance of self-healing(SH) capacitor using a PFN-type modulator. From the test results, it was confirmed that the SH capacitor has energy densities more than three times compared with the conventional non-healing(NH) capacitor. This paper describes SH capacitors developed by KEK. (author)

  12. Thermal simulation for geometric optimization of metallized polypropylene film capacitors

    El-Husseini, M.,; VENET, Pascal; Rojat, Gérard; Joubert, Charles


    In this paper, we use an analytic model to calculate the losses in the metallized polypropylene film capacitors. The model is validated experimentally for capacitors having the same capacitance but different geometry. For each group of capacitors a temperature distribution in the roll is assumed with the aim of optimizing its thermal performance. It appears that the heating of a long capacitor is higher than that of an equivalent flat capacitor subjected to the same electric stresses.

  13. Definite Solution of the Two Capacitors Paradox

    Pankovic, Vladan


    In this work we suggest very simple solution of the two capacitors paradox in the completely ideal (without any electrical resistance or inductivity) electrical circuit. Namely, it is shown that electrical field energy loss corresponds to works done by electrical fields of both capacitors by movement of the electrical charge. It is all and nothing more (some dissipative processes, e.g. Joule heating and electromagnetic wave emission effects) is necessary.

  14. Transmission Line Resonator Segmented with Series Capacitors

    Zhurbenko, Vitaliy; Boer, Vincent; Petersen, Esben Thade


    Transmission line resonators are often used as coils in high field MRI. Due to distributed nature of such resonators, coils based on them produce inhomogeneous field. This work investigates application of series capacitors to improve field homogeneity along the resonator. The equations for optimal...... values of evenly distributed capacitors are presented. The performances of the segmented resonator and a regular transmission line resonator are compared....

  15. Choreographing the fly's danse macabre.

    Poon, Peter C; Pletcher, Scott D


    In several species, immune signaling networks are emerging as critical modulators of disease resistance, energy metabolism, and aging. In this issue of Cell Metabolism, Ren et al. (2007) lay the groundwork for dissecting the mechanisms of this coordination by characterizing the interplay between microbial pathogens and aging in the fly. PMID:17681142

  16. Recent trend of oil impregnated capacitor (self healing type)

    Shioda, Kohei; Wada, Eiichi; Fukai, Masayasu


    This paper describes the self healing type high pressure capacitor which is the newest type in oil impregnated capacitors. The self healing type oil impregnated capacitor has a structure holding a sheet of polypropylene film derivative between two sheets of double side metalized paper and this paper supports electrodes. Features of this capacitor are self healing, good impregnation, and built-in pressure sensing type protector. Performance of this capacitor depends on the impregnating agent and electrode. On the other hand, electric characteristic, dielectric characteristic, life, and safety of this capacitor are also examined. As a result, self healing type oil impregnated capacitors are suitable for capacitors of low-loss and high potential gradient. The self healing oil impregnated capacitor is supposed to play an important role for miniaturization, weight reduction, and resource saving. (10 figs, 1 tab)

  17. Inhibiting α-synuclein oligomerization by stable cell-penetrating β-synuclein fragments recovers phenotype of Parkinson's disease model flies.

    Ronit Shaltiel-Karyo

    Full Text Available The intracellular oligomerization of α-synuclein is associated with Parkinson's disease and appears to be an important target for disease-modifying treatment. Yet, to date, there is no specific inhibitor for this aggregation process. Using unbiased systematic peptide array analysis, we identified molecular interaction domains within the β-synuclein polypeptide that specifically binds α-synuclein. Adding such peptide fragments to α-synuclein significantly reduced both amyloid fibrils and soluble oligomer formation in vitro. A retro-inverso analogue of the best peptide inhibitor was designed to develop the identified molecular recognition module into a drug candidate. While this peptide shows indistinguishable activity as compared to the native peptide, it is stable in mouse serum and penetrates α-synuclein over-expressing cells. The interaction interface between the D-amino acid peptide and α-synuclein was mapped by Nuclear Magnetic Resonance spectroscopy. Finally, administering the retro-inverso peptide to a Drosophila model expressing mutant A53T α-synuclein in the nervous system, resulted in a significant recovery of the behavioral abnormalities of the treated flies and in a significant reduction in α-synuclein accumulation in the brains of the flies. The engineered retro-inverso peptide can serve as a lead for developing a novel class of therapeutic agents to treat Parkinson's disease.

  18. Flying insects and Campylobacter

    Hald, Birthe; Sommer, Helle Mølgaard; Skovgård, Henrik

    Campylobacter in flies Flies of the Muscidae family forage on all kind of faeces – various fly species have different preferences. M domestica prefer pigs, horses and cattle faeces, animals which are all known to frequently excrete Campylobacter. As a result, the insects pick up pathogenic micro...

  19. Determinants of propensity to fly

    Hugo Gordijn


    Flying has become a common form of travel. The main reasons not to fly are fear of flying and the cost of flying. Youngsters fly more often than older people. Only above 75 years diminishes the propensity to considerably. Women fly as often as men except for business reasons. The group with the hig

  20. High-Temperature Capacitor Polymer Films

    Tan, Daniel; Zhang, Lili; Chen, Qin; Irwin, Patricia


    Film capacitor technology has been under development for over half a century to meet various applications such as direct-current link capacitors for transportation, converters/inverters for power electronics, controls for deep well drilling of oil and gas, direct energy weapons for military use, and high-frequency coupling circuitry. The biaxially oriented polypropylene film capacitor remains the state-of-the-art technology; however, it is not able to meet increasing demand for high-temperature (>125°C) applications. A number of dielectric materials capable of operating at high temperatures (>140°C) have attracted investigation, and their modifications are being pursued to achieve higher volumetric efficiency as well. This paper highlights the status of polymer dielectric film development and its feasibility for capacitor applications. High-temperature polymers such as polyetherimide (PEI), polyimide, and polyetheretherketone were the focus of our studies. PEI film was found to be the preferred choice for high-temperature film capacitor development due to its thermal stability, dielectric properties, and scalability.

  1. Switched capacitor arrays analog memory for sparse data sampling

    We present the design and the test performed on ADeLinel, a Full-Custom Analog Memory for sparse data sampling. It has been designed as an array of switched capacitors. It is only one channel of 8 cells. The control part of the ADeLine chip is custom designed for the size reduction, high speed performance and low power dissipation. The memory has been integrated in double poly, double metal AMS 0.8 μm CMOS. It has 3.5 V input and output swings, a linearity within ± 6 mV in a 2 V range and 11 bits of resolution. (author)

  2. The Fly Printer - Extended

    Beloff, Laura; Klaus, Malena


    Artist talk / Work-in-progress What is the purpose of a machine or an artifact, like the Fly Printer, that is dislocated, that produces images that have no meaning, no instrumentality, that depict nothing in the world? The biological and the cultural are reunited in this apparatus as a possibility...... to break through a common way of depicting the world, trying to find different surfaces and using strange apparatus to insist in the interstice of visibility. The Fly Printer is a printing apparatus in a form of a closed environment that contains a flock of fruit flies. The flies eat special food...... that is prepared for them that is mixed with laser jet printer inks. The flies digest the food and gradually print different color dots onto the paper that is placed under the fly habitat. In the Fly Printer biological organisms are used for replacing a standard part of our common printer technology...

  3. BioCapacitor--a novel category of biosensor.

    Hanashi, Takuya; Yamazaki, Tomohiko; Tsugawa, Wakako; Ferri, Stefano; Nakayama, Daisuke; Tomiyama, Masamitsu; Ikebukuro, Kazunori; Sode, Koji


    This research reports on the development of an innovative biosensor, known as BioCapacitor, in which biological recognition elements are combined with a capacitor functioning as the transducer. The analytical procedure of the BioCapacitor is based on the following principle: a biocatalyst, acting as a biological recognition element, oxidizes or reduces the analyte to generate electric power, which is then charged into a capacitor via a charge pump circuit (switched capacitor regulator) until the capacitors attains full capacity. Since the charging rate of the capacitor depends on the biocatalytic reaction of the analyte, the analyte concentration can be determined by monitoring the time/frequency required for the charge/discharge cycle of the BioCapacitor via a charge pump circuit. As a representative model, we constructed a BioCapacitor composed of FAD-dependent glucose dehydrogenase (FADGDH) as the anodic catalyst, and attempted a glucose measurement. Charge/discharge frequency of the BioCapacitor increased with the increasing glucose concentration, exhibiting good correlation with glucose concentration. We have also constructed a wireless sensing system using the BioCapacitor combined with an infrared light emitting diode (IRLED), an IR phototransistor system. In the presence of glucose, the IRLED signal was observed due to the discharge of the BioCapacitor and detected by an IR phototransistor in a wireless receiver. Therefore, a BioCapacitor employing FADGDH as its anodic catalyst can be operated as a self-powered enzyme sensor. PMID:19013784

  4. Antenna Miniaturization with MEMS Tunable Capacitors

    Barrio, Samantha Caporal Del; Morris, Art; Pedersen, Gert Frølund


    In today’s mobile device market, there is a strong need for efficient antenna miniaturization. Tunable antennas are a very promising way to reduce antenna volume while enlarging its operating bandwidth. MEMS tunable capacitors are state-ofthe- art in terms of insertion loss and their characterist......In today’s mobile device market, there is a strong need for efficient antenna miniaturization. Tunable antennas are a very promising way to reduce antenna volume while enlarging its operating bandwidth. MEMS tunable capacitors are state-ofthe- art in terms of insertion loss and their...

  5. Printed Barium Strontium Titanate capacitors on silicon

    In this paper, we show that Barium Strontium Titanate (BST) films can be prepared by inkjet printing of sol–gel precursors on platinized silicon substrate. Moreover, a functional variable capacitor working in the GHz range has been made without any lithography or etching steps. Finally, this technology requires 40 times less precursors than the standard sol–gel spin-coating technique. - Highlights: • Inkjet printing of Barium Strontium Titanate films • Deposition on silicon substrate • Inkjet printed silver top electrode • First ever BST films thinner than 1 μm RF functional variable capacitor that has required no lithography

  6. Printed Barium Strontium Titanate capacitors on silicon

    Sette, Daniele [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Luxembourg Institute of Science and Technology LIST, Materials Research and Technology Department, L-4422 Belvaux (Luxembourg); Kovacova, Veronika [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Defay, Emmanuel, E-mail: [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Luxembourg Institute of Science and Technology LIST, Materials Research and Technology Department, L-4422 Belvaux (Luxembourg)


    In this paper, we show that Barium Strontium Titanate (BST) films can be prepared by inkjet printing of sol–gel precursors on platinized silicon substrate. Moreover, a functional variable capacitor working in the GHz range has been made without any lithography or etching steps. Finally, this technology requires 40 times less precursors than the standard sol–gel spin-coating technique. - Highlights: • Inkjet printing of Barium Strontium Titanate films • Deposition on silicon substrate • Inkjet printed silver top electrode • First ever BST films thinner than 1 μm RF functional variable capacitor that has required no lithography.

  7. Clocking Scheme for Switched-Capacitor Circuits

    Steensgaard-Madsen, Jesper

    A novel clocking scheme for switched-capacitor (SC) circuits is presented. It can enhance the understanding of SC circuits and the errors caused by MOSFET (MOS) switches. Charge errors, and techniques to make SC circuits less sensitive to them are discussed.......A novel clocking scheme for switched-capacitor (SC) circuits is presented. It can enhance the understanding of SC circuits and the errors caused by MOSFET (MOS) switches. Charge errors, and techniques to make SC circuits less sensitive to them are discussed....

  8. Electric field mapping inside metallized film capacitors

    Nielsen, Dennis Achton; Popok, Vladimir; Pedersen, Kjeld


    Failure mode and effect analysis (FMEA) is an important step in the reliability assessment process of electric components. It provides knowledge of the physics of failure of a component that has been subjected to a given stress profile. This knowledge enables improvement of the component robustness...... of the metallization stripes had lost contact to the end-spray. Thus, it is shown that the surface electric potential distributions on micro-sectioned film capacitors can be obtained through KPFM analysis. We have, from KPFM measurements, shown that the degraded capacitors under investigation had suffered from...

  9. Low-Voltage Switched-Capacitor Circuits

    Bidari, E.; Keskin, M.; Maloberti, F.; Moon, U.; Steensgaard-Madsen, Jesper; Temes, G.C.

    Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications.......Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications....

  10. Clocking Scheme for Switched-Capacitor Circuits

    Steensgaard-Madsen, Jesper


    A novel clocking scheme for switched-capacitor (SC) circuits is presented. It can enhance the understanding of SC circuits and the errors caused by MOSFET (MOS) switches. Charge errors, and techniques to make SC circuits less sensitive to them are discussed.......A novel clocking scheme for switched-capacitor (SC) circuits is presented. It can enhance the understanding of SC circuits and the errors caused by MOSFET (MOS) switches. Charge errors, and techniques to make SC circuits less sensitive to them are discussed....

  11. Wide Temperature DC Link Capacitors for Aerospace Power Electronics Project

    National Aeronautics and Space Administration — This project will develop advanced DC link capacitors using flexible ultrathin glass dielectric materials. The glass capacitor will be able to be operated in a...

  12. Fly ash carbon passivation

    La Count, Robert B; Baltrus, John P; Kern, Douglas G


    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  13. Design and Characterization of Vertical Mesh Capacitors in Standard CMOS

    Christensen, Kåre Tais


    This paper shows how good RF capacitors can be made in a standard digital CMOS process. The capacitors which are also well suited for binary weighted switched capacitor banks show very good RF performance: Q-values of 57 at 4.0 GHz, a density of 0.27 fF/μ2, 2.2 μm wide shielded unit capacitors, 6...

  14. Iodine encapsulation in CNTs and its application for electrochemical capacitor

    Taniguchi, Y.; Ishii, Y.; Rashid, M.; Syakirin, A.; Al-zubaidi, A.; Kawasaki, S.


    We report the experimental results for new type electrochemical capacitor using iodine redox reaction in single-walled carbon nanotubes (SWCNTs). It was found that the energy density of the present redox capacitor using SWCNTs is almost three times larger than that of the normal electric double layer capacitor.

  15. The mystery of lost energy in ideal capacitors

    James, A. P.


    The classical two-capacitor problem shows a mysterious lose of energy even under lossless conditions and questions the basic understanding of energy relation in a capacitor. Here, we present a solution to the classical two-capacitor problem. We find that by reinterpreting the energy calculations we achieve no lose of energy thereby obeying the conservation of energy law.

  16. The role of the hedgehog/patched signaling pathway in epithelial stem cell proliferation:from fly to human



    The hedgehog-patched(hh-ptc)intercellular signaling pathway has recently been shown to control the proliferation of epithelial stem cells in both Drosophila and Vertebrated.Mutant and ectopic expression analyses in Drosophila suggest that the HH protein diffuses from the signaling cells to promote the proliferation of nearby ovarian somatic stem cells by antagonizing the suppression of its receptor PTC towards the CI transcription factor in the stem cells.Consequently,the transcription of CIdependent genes leads to stem cell proliferation.This regulatory pathway appears to function also in vertebrates, where defects in ptc cause basal cell carcinoma,tumors of epidermal stem cell origin.Basal cell carcinoma can also be induced by ectopic expression of Sonic hedgehog (shh) or Glil,the vertebrate homolog of ci.These studies suggest the conservation of the hh signaling pathway in controlling epithelial stem cell divisions among different organisma.

  17. Performance of a combined capacitor based on ultrafine nickel oxide/carbon nanotubes composite electrodes

    Xiaofeng Wang; Yanqiu Cao; Yiqiang Lu; Qiqian Sha; Ji Liang


    A new sol-gel process for the preparation of ultrafine nickel hydroxide electrode materials was developed. The composite electrodes consisting of carbon nanotubes and Ni(OH)2 were developed by mixing the hydroxide and carbon nanotubes together in different mass ratios. In order to enhance energy density, a combined type pseudocapacitor/electric double layer capacitor was considered and its electrochemical properties were characterized by cyclic voltammetry and dc charge/discharge test. The combined capacitor shows excellent capacitor behavior with an operating voltage up to 1.6 V in KOH aqueous electrolyte. Stable charge/discharge behaviors were observed with much higher specific capacitance values of 24 F/g compared with that of EDLC (12F/g) by introducing 60% Ni(OH)2 in the anode material. By using the modified anode of a Ni(OH)2/carbon nanotubes composite electrode, the specific capacitance of the cell was less sensitive to discharge current density compared with that of the capacitor employing pure nickel hydroxide as anode. The combined capacitor in this study exhibits high energy density and stable power characteristics.

  18. Electrochemical performance of nickel oxide/KOH/active carbon super-capacitor


    The fabrication and characterization of new type Nickel oxide/KOH/Active carbon super-capacitor have been described. Porous nickeloxide was prepared by hydrolysis of nickel acetate and heated in air at 300℃. The resulting nickel oxide behaved as an electrochemical capacitor electrode with a specific capacitance (50-70F/g) superior to most active carbon electrodes. This kind of nickel oxide maintained highutilization at high rate of discharge (i.e., high power density) and had excellent cycle life more than 1000 times, while the capacitance of the cell composed of two identical nickel oxide electrodes was poor at high discharge current density and the maximum operational voltage of this type capacitor was limited to 0.5V. A new type super-capacitorwas designed in which the nickel oxide and the active carbon were applied to the positive and negative electrodes respectively. The breakdown voltage of this type super-capacitor was improved effectively to 0.8V and excellent characteristic of high power discharge was attained in this way. The Nickel oxide/KOH/Active carbon super-capacitor has promising potentials in portable telecommunications, uninterruptable power supplies and battery load leveling applications.

  19. Equal Plate Charges on Series Capacitors?

    Illman, B. L.; Carlson, G. T.


    Provides a line of reasoning in support of the contention that the equal charge proposition is at best an approximation. Shows how the assumption of equal plate charge on capacitors in series contradicts the conservative nature of the electric field. (ZWH)

  20. Capacitors and Resistance-Capacitance Networks.

    Balabanian, Norman; Root, Augustin A.

    This programed textbook was developed under a contract with the United States Office of Education as Number 5 in a series of materials for use in an electrical engineering sequence. It is divided into three parts--(1) capacitors, (2) voltage-current relationships, and (3) simple resistance-capacitance networks. (DH)

  1. Circular plate capacitor with different disks

    Paffuti, Giampiero; Di Lieto, Alberto; Maccarrone, Francesco


    In this paper we write a system of integral equations for a capacitor composed by two disks of different radii, generalizing Love's equation for equal disks. We compute the complete asymptotic form of the capacitance matrix both for large and small distances obtaining a generalization of Kirchhoff's formula for the latter case.

  2. Low-Voltage Switched-Capacitor Circuits

    Bidari, E.; Keskin, M.; Maloberti, F.;


    Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications....

  3. High voltage AC/AC electrochemical capacitor operating at low temperature in salt aqueous electrolyte

    Abbas, Qamar; Béguin, François


    We demonstrate that an activated carbon (AC)-based electrochemical capacitor implementing aqueous lithium sulfate electrolyte in 7:3 vol:vol water/methanol mixture can operate down to -40 °C with good electrochemical performance. Three-electrode cell investigations show that the faradaic contributions related with hydrogen chemisorption in the negative AC electrode are thermodynamically unfavored at -40 °C, enabling the system to work as a typical electrical double-layer (EDL) capacitor. After prolonged floating of the AC/AC capacitor at 1.6 V and -40°C, the capacitance, equivalent series resistance and efficiency remain constant, demonstrating the absence of ageing related with side redox reactions at this temperature. Interestingly, when temperature is increased back to 24 °C, the redox behavior due to hydrogen storage reappears and the system behaves as a freshly prepared one.

  4. Carbon additives for electrical double layer capacitor electrodes

    Weingarth, D.; Cericola, D.; Mornaghini, F. C. F.; Hucke, T.; Kötz, R.


    Electrochemical double layer capacitors (EDLCs) are inherently high power devices when compared to rechargeable batteries. While capacitance and energy storage ability are mainly increased by optimizing the electrode active material or the electrolyte, the power capability could be improved by including conductive additives in the electrode formulations. This publication deals with the use of four different carbon additives - two carbon blacks and two graphites - in standard activated carbon based EDLC electrodes. The investigations include: (i) physical characterization of carbon powder mixtures such as surface area, press density, and electrical resistivity measurements, and (ii), electrochemical characterization via impedance spectroscopy and cyclic voltammetry of full cells made with electrodes containing 5 wt.% of carbon additive and compared to cells made with pure activated carbon electrodes in organic electrolyte. Improved cell performance was observed in both impedance and cyclic voltammetry responses. The results are discussed considering the main characteristics of the different carbon additives, and important considerations about electrode structure and processability are drawn.

  5. High energy density capacitors using nano-structure multilayer technology

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.


    Today, many pulse power and industrial applications are limited by capacitor performance. While incremental improvements are anticipated from existing capacitor technologies, significant advances are needed in energy density to enable these applications for both the military and for American economic competitiveness. We propose a program to research and develop a novel technology for making high voltage, high energy density capacitors. Nano-structure multilayer technologies developed at LLNL may well provide a breakthrough in capacitor performance. Our controlled sputtering techniques are capable of laying down extraordinarily smooth sub-micron layers of dielectric and conductor materials. With this technology, high voltage capacitors with an order of magnitude improvement in energy density may be achievable. Well-understood dielectrics and new materials will be investigated for use with this technology. Capacitors developed by nano-structure multilayer technology are inherently solid state, exhibiting extraordinary mechanical and thermal properties. The conceptual design of a Notepad capacitor is discussed to illustrate capacitor and capacitor bank design and performance with this technology. We propose a two phase R&D program to address DNA`s capacitor needs for electro-thermal propulsion and similar pulse power programs. Phase 1 will prove the concept and further our understanding of dielectric materials and design tradeoffs with multilayers. Nano-structure multilayer capacitors will be developed and characterized. As our materials research and modeling prove successful, technology insertion in our capacitor designs will improve the possibility for dramatic performance improvements. In Phase 2, we will make Notepad capacitors, construct a capacitor bank and demonstrate its performance in a meaningful pulse power application. We will work with industrial partners to design full scale manufacturing and move this technology to industry for volume production.

  6. The onion fly

    This paper describes the origin, practical application, problems in application and prospects of control of the onion fly, Delia antiqua (Diptera: Anthomyiidae), in the Netherlands by the Sterile Insect Technique (SIT). The larva of the onion fly is a severe pest in onions in temperate regions. Development of resistance of the onion fly against insecticides caused research on the SIT to be started by the Dutch Government in 1965. This research was on mass-rearing, long-term storage of pupae, sterilization, and release and ratio assessment techniques. By 1979 sufficient information had been turned over to any interested private company. In the case of the onion fly the SIT can be applied like a control treatment instead of chemical control to individual onion fields. This is due to the limited dispersal activity of the flies and the scattered distribution of onion fields in the Netherlands, with 5-10% of the onion growing areas planted with onions

  7. High ALDH Activity Identifies Chemotherapy-Resistant Ewing's Sarcoma Stem Cells That Retain Sensitivity to EWS-FLI1 Inhibition

    Ola Awad; Jason T Yustein; Preeti Shah; Naheed Gul; Varalakshmi Katuri; Alison O'Neill; Yali Kong; Brown, Milton L.; Toretsky, Jeffrey A.; Loeb, David M.


    BACKGROUND: Cancer stem cells are a chemotherapy-resistant population capable of self-renewal and of regenerating the bulk tumor, thereby causing relapse and patient death. Ewing's sarcoma, the second most common form of bone tumor in adolescents and young adults, follows a clinical pattern consistent with the Cancer Stem Cell model - remission is easily achieved, even for patients with metastatic disease, but relapse remains frequent and is usually fatal. METHODOLOGY/PRINCIPAL FINDINGS: We h...

  8. High-Energy-Density Electrolytic Capacitors

    Yen, Shiao-Ping S.; Lewis, Carol R.


    Reductions in weight and volume make new application possible. Supercapacitors and improved ultracapacitors advanced electrolytic capacitors developed for use as electric-load-leveling devices in such applications as electric vehicle propulsion systems, portable power tools, and low-voltage pulsed power supplies. One primary advantage: offer power densities much higher than storage batteries. Capacitors used in pulse mode, with short charge and discharge times. Derived from commercially available ultracapacitors. Made of lightweight materials; incorporate electrode/electrolyte material systems capable of operation at voltages higher than previous electrode/electrolyte systems. By use of innovative designs and manufacturing processes, made in wide range of rated capacitances and in rated operating potentials ranging from few to several hundred volts.

  9. Hidden Momentum in a moving Capacitor

    Asti, Giovanni


    A very simple system like a parallel-plate capacitor reveals striking features when we examine the peculiar phenomena appearing when it is moving at low speed in different directions. Both hidden momentum and hidden energy appear and their addition, with their sign, to the corresponding electromagnetic component results in the expected ordinary kinetic momentum or energy of the electrostatic mass equivalent. What's happening is that passing from one inertial reference frame to another, part of the energy or momentum is transferred from the electromagnetic component to the material part of the system or the other way around. A paradoxical self-accelerating behavior is evidenced if one admits that the capacitor is discharging through an electrical resistance during its motion. It is shown that one must take into account the mass of the produced heat.

  10. Tunable microstrip resonators with ferroelectric capacitors

    Zakharov, A. V.; Ilchenko, Mikhail Ye.; Karnauh, V. Ya.; Pinchuk, L. S.


    The question of increasing the tuning band of microstrip resonators that use ferroelectric capacitors for tuning in the region of increased electric lengths is considered which allows using them in the upper part of the centimeter band (Ku-band, K-band). Band properties of regular and step-irregular resonators operating at the lowest resonant frequency are analyzed.It is determined that step-irregular resonators possess a wider tuning band than regular ones. Their use allows widening the tuni...

  11. The elastic capacitor and its unusual properties

    Partensky, Michael B.


    The 'elastic capacitor' (EC) model was first introduced in studies of lipid bilayers (the major components of biological membranes). This electro-elastic model accounted for the compression of a membrane under applied voltage and allowed obtaining information about the membrane's elastic properties from the measurements of its capacitance. Later on, ECs were used to analyze the electrical breakdown of biological membranes. The EC model was also helpful in studies of electric double layers in ...

  12. Materials development for commercial multilayer ceramic capacitors

    Mikkenie, Ronald


    Electronic devices like notebooks, smart phones, GPS units, LED TVs and other daily life applications are produced with increased functionality and complexity from year to year. Today’s electronic devices must be equipped with new smart electronic circuitry designs to add more functionality within a single device, while not making them larger in size. As the electronic circuits are made of various components, active semiconducting chips and passive components, like resistors, capacitors and i...

  13. Polarization fatigue of organic ferroelectric capacitors

    Dong Zhao; Ilias Katsouras; Mengyuan Li; Kamal Asadi; Junto Tsurumi; Gunnar Glasser; Jun Takeya; Blom, Paul W. M.; de Leeuw, Dago M.


    The polarization of the ferroelectric polymer P(VDF-TrFE) decreases upon prolonged cycling. Understanding of this fatigue behavior is of great technological importance for the implementation of P(VDF-TrFE) in random-access memories. However, the origin of fatigue is still ambiguous. Here we investigate fatigue in thin-film capacitors by systematically varying the frequency and amplitude of the driving waveform. We show that the fatigue is due to delamination of the top electrode. The origin i...

  14. A 100 MS/s 9 bit 0.43 mW SAR ADC with custom capacitor array

    Jingjing, Wang; Zemin, Feng; Rongjin, Xu; Chixiao, Chen; Fan, Ye; Jun, Xu; Junyan, Ren


    A low power 9 bit 100 MS/s successive approximation register analog-to-digital converter (SAR ADC) with custom capacitor array is presented. A brand-new 3-D MOM unit capacitor is used as the basic capacitor cell of this capacitor array. The unit capacitor has a capacitance of 1 fF. Besides, the advanced capacitor array structure and switch mode decrease the power consumption a lot. To verify the effectiveness of this low power design, the 9 bit 100 MS/s SAR ADC is implemented in TSMC IP9M 65 nm LP CMOS technology. The measurement results demonstrate that this design achieves an effective number of bits (ENOB) of 7.4 bit, a signal-to-noise plus distortion ratio (SNDR) of 46.40 dB and a spurious-free dynamic range (SFDR) of 62.31 dB at 100 MS/s with 1 MHz input. The SAR ADC core occupies an area of 0.030 mm2 and consumes 0.43 mW under a supply voltage of 1.2 V. The figure of merit (FOM) of the SAR ADC achieves 23.75 fJ/conv. Project supported by the National High-Tech Research and Development Program of China (No. 2013AA014101).

  15. Matching Properties of Femtofarad and Sub-Femtofarad MOM Capacitors

    Omran, Hesham


    Small metal-oxide-metal (MOM) capacitors are essential to energy-efficient mixed-signal integrated circuit design. However, only few reports discuss their matching properties based on large sets of measured data. In this paper, we report matching properties of femtofarad and sub-femtofarad MOM vertical-field parallel-plate capacitors and lateral-field fringing capacitors. We study the effect of both the finger-length and finger-spacing on the mismatch of lateral-field capacitors. In addition, we compare the matching properties and the area efficiency of vertical-field and lateral-field capacitors. We use direct mismatch measurement technique, and we illustrate its feasibility using experimental measurements and Monte Carlo simulations. The test-chips are fabricated in a 0.18 \\\\mutext{m} CMOS process. A large number of test structures is characterized (4800 test structures), which improves the statistical reliability of the extracted mismatch information. Despite conventional wisdom, extensive measurements show that vertical-field and lateral-field MOM capacitors have the same matching properties when the actual capacitor area is considered. Measurements show that the mismatch depends on the capacitor area but not on the spacing; thus, for a given mismatch specification, the lateral-field MOM capacitor can have arbitrarily small capacitance by increasing the spacing between the capacitor fingers, at the expense of increased chip area.

  16. Cryogenic Cermic Multilayer Capacitors for Power Electronics

    Recent advances in the areas of high temperature superconductors and low temperature MOSFET devices have opened the door to the possibility of developing highly efficient low-temperature power electronics. The most commonly used high-efficiency capacitors are based on high dielectric constant (K ∼ 1000-4000) barium titanate doped to yield and X7R temperature dependence (±15% change in capacitance from -55 deg. C to 125 deg. C); however, below their minimum use temperature the capacitance drops-off quickly leading to a low volumetric efficiency and high temperature coefficient of capacitance (TCC) at cryogenic temperatures.A series of low temperature materials with moderate to high dielectric constants have been specifically developed for low temperature operation (below 80K). The capacitors fall into three main categories: low TCC, high volumetric efficiency, and energy storage. In the low TCC category, co-fired multilayer ceramic capacitors (MLCCs) were fabricated with capacitance values up to 62nF at 30K, TCCs from 0.9 to 2% below 80K, and losses on the order of 0.0001. In the high volumetric efficiency category, dielectrics with permittivities ranging from 1,000 to 30,000 were demonstrated

  17. Substituted Quaternary Ammonium Salts Improve Low-Temperature Performance of Double-Layer Capacitors

    Brandon, Erik J.; Smart, Marshall C.; West, William C.


    Double-layer capacitors are unique energy storage devices, capable of supporting large current pulses as well as a very high number of charging and discharging cycles. The performance of doublelayer capacitors is highly dependent on the nature of the electrolyte system used. Many applications, including for electric and fuel cell vehicles, back-up diesel generators, wind generator pitch control back-up power systems, environmental and structural distributed sensors, and spacecraft avionics, can potentially benefit from the use of double-layer capacitors with lower equivalent series resistances (ESRs) over wider temperature limits. Higher ESRs result in decreased power output, which is a particular problem at lower temperatures. Commercially available cells are typically rated for operation down to only 40 C. Previous briefs [for example, Low Temperature Supercapacitors (NPO-44386), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), p. 32, and Supercapacitor Electrolyte Solvents With Liquid Range Below 80 C (NPO-44855), NASA Tech Briefs, Vol. 34, No. 1 (January 2010), p. 44] discussed the use of electrolytes that employed low-melting-point co-solvents to depress the freezing point of traditional acetonitrile-based electrolytes. Using these modified electrolyte formulations can extend the low-temperature operational limit of double-layer capacitors beyond that of commercially available cells. This previous work has shown that although the measured capacitance is relatively insensitive to temperature, the ESR can rise rapidly at low temperatures, due to decreased electrolyte conductance within the pores of the high surface- area carbon electrodes. Most of these advanced electrolyte systems featured tetraethylammonium tetrafluoroborate (TEATFB) as the salt. More recent work at JPL indicates the use of the asymmetric quaternary ammonium salt triethylmethylammonium tetrafluoroborate (TEMATFB) or spiro-(l,l')-bipyrrolidium tetrafluoroborate (SBPBF4) in a 1:1 by volume solvent

  18. Capacitors can radiate - some consequences of the two-capacitor problem with radiation

    Choy, T C


    We fill a gap in the arguments of Boykin et al [American Journal of Physics, Vol 70 No. 4, pp 415-420 (2002)] by not invoking an electric current loop (i.e. magnetic dipole model) to account for the radiation energy loss, since an obvious corollary of their results is that the capacitors should radiate directly even if the connecting wires are shrunk to zero length. That this is so is shown here by a direct derivation of capacitor radiation using an oscillating electric dipole radiator model for the capacitors as well as the alternative less widely known magnetic 'charge' current loop representation for an electric dipole [see for example "Electromagnetic Waves" by S.A.Schlekunoff, van Nostrand (1948)]. Implications for Electromagnetic Compliance (EMC) issues as well as novel antenna designs further motivate the purpose of this paper.

  19. 64-Channel, 5 GSPS ADC Module with Switched Capacitor Arrays

    We present a 5 GSPS ADC/Data processing module with up to 64 channels and 2048 cells per channel, designed for fast-sampling, front-end applications. This is a 6U VME board that incorporates 16 pieces DRS4 ( (, [1]) Switched Capacitor Array chips developed at Paul Scherrer Institut, Switzerland. The 16 DRS4 chips are grouped in four independent input blocks. A block, with a geometric size of 43×120 mm, has four pieces DRS4 chips, four pieces AD9222 converters, and one Altera Stratix III FPGA. Each DRS4 chip has eight channels and each channel has 1024 sampling cells, which can be daisy-chained for larger sampling depth. This feature allows for a great level of flexibility in choosing the number of channels relative to capacitor array size, for a particular application. The first prototype Printed Circuit Board (PCB) was designed for a sampling depth of 2048 cells and 16 channels in a 42 mm wide block, i.e. 64 channels for the 6U VME board. This compact form factor allows for these input blocks to be used as front-end electronics for the Cherenkov Telescope Array (CTA) cameras. In this VME board, the four blocks are fully independent and can run each in different modes without any conflict. A global FPGA, also a Stratix III device, provides control and interfacing. The module can run with a local oscillator or with input system clocks in the range of 20–550 MHz. The front panel is fitted with a 2.5 Gbps serial link transceiver

  20. The effect of lithium loadings on anode to the voltage drop during charge and discharge of Li-ion capacitors

    Cao, W. J.; Greenleaf, M.; Li, Y. X.; Adams, D.; Hagen, M.; Doung, T.; Zheng, J. P.


    The IR voltage drop from the anode and cathode of Li-ion capacitors during charge and discharge was studied. Li-ion capacitors were made with activated carbon cathode and hard carbon anode with different loadings of stabilized lithium metal powder (SLMP). It was found that the LICs with high SLMP loadings showed smaller voltage drop than LICs with low SLMP loadings. It was also found that at low SLMP loadings, the IR voltage drops at high cell voltages were smaller than that at low cell voltages; while at high SLMP loadings, small IR voltage drops were obtained for both low and high cell voltages. The electrochemical impedance spectroscopy confirmed that voltage drops are directly related to the internal resistances of Li-ion capacitors.

  1. Super capacitor modeling with artificial neural network (ANN)

    Marie-Francoise, J.N.; Gualous, H.; Berthon, A. [Universite de Franche-Comte, Lab. en Electronique, Electrotechnique et Systemes (L2ES), UTBM, INRETS (LRE T31) 90 - Belfort (France)


    This paper presents super-capacitors modeling using Artificial Neural Network (ANN). The principle consists on a black box nonlinear multiple inputs single output (MISO) model. The system inputs are temperature and current, the output is the super-capacitor voltage. The learning and the validation of the ANN model from experimental charge and discharge of super-capacitor establish the relationship between inputs and output. The learning and the validation of the ANN model use experimental results of 2700 F, 3700 F and a super-capacitor pack. Once the network is trained, the ANN model can predict the super-capacitor behaviour with temperature variations. The update parameters of the ANN model are performed thanks to Levenberg-Marquardt method in order to minimize the error between the output of the system and the predicted output. The obtained results with the ANN model of super-capacitor and experimental ones are in good agreement. (authors)

  2. Capacitor requirements for controlled thermonuclear experiments and reactors

    Future controlled thermonuclear experiments as well as controlled thermonuclear reactors will require substantial numbers of capacitors. The demands on these units are likely to be quite severe and quite different from the normal demands placed on either present energy storage capacitors or present power factor correction capacitors. It is unlikely that these two types will suffice for all necessary Controlled Thermonuclear Research (CTR) applications. The types of capacitors required for the various CTR operating conditions are enumerated. Factors that influence the life, cost and operating abilities of these types of capacitors are discussed. The problems of capacitors in a radiation environment are considered. Areas are defined where future research is needed. Some directions that this research should take are suggested. (U.S.)

  3. Capacitors can radiate - some consequences of the two-capacitor problem with radiation

    Choy, T. C.


    We fill a gap in the arguments of Boykin et al [American Journal of Physics, Vol 70 No. 4, pp 415-420 (2002)] by not invoking an electric current loop (i.e. magnetic dipole model) to account for the radiation energy loss, since an obvious corollary of their results is that the capacitors should radiate directly even if the connecting wires are shrunk to zero length. That this is so is shown here by a direct derivation of capacitor radiation using an oscillating electric dipole radiator model ...

  4. Study of electric capacitors using Finite Element Method

    Alina Neamț; Anca Bărcuteanu


    A capacitor is made of two armatures and a dielectric between the two armatures. In this paper, we are going to study the plane capacitor , which is made of two equal metal armatures, plane and parallel, having the S surface, situated at a distance d much shorter than the armatures dimensions, between which there is a liniar, homogenous and isotropic dielectric having a constant electrical permittivity.The purpose of studying the plane capacitor, through MEF, presented in this...

  5. Optimization of capacitor banks in the Skagerak networks transmission grid

    Ledesma, Hector Marañon


    Capacitor banks have been widely used in electric power networks. This master thesis presents a study of introducing new capacitor banks into a transmission network. The network comprises two areas at Telemark and Vestfold with voltages levels of 55kV, 66kV and 132kV, owned by Skagerak Nett AS. Capacitor banks improve the electric network in five ways: power factor correction, increased capacity, reduction of losses, voltage support and reactive power support. International sta...

  6. MOSFET and MOS capacitor responses to ionizing radiation

    Benedetto, J. M.; Boesch, H. E., Jr.


    The ionizing radiation responses of metal oxide semiconductor (MOS) field-effect transistors (FETs) and MOS capacitors are compared. It is shown that the radiation-induced threshold voltage shift correlates closely with the shift in the MOS capacitor inversion voltage. The radiation-induced interface-state density of the MOSFETs and MOS capacitors was determined by several techniques. It is shown that the presence of 'slow' states can interfere with the interface-state measurements.

  7. Flying insects and robots

    Ellington, Charlie


    Understanding flight mechanics of insects can aid engineers in developing intelligent flying robots. In this seminal book, biologists and engineers detail the mechanics, technology, and intelligence of insects then discuss potential benefits of their research.

  8. Fruit fly eradication: Argentina

    Fruit exports account for 9% of Argentina's total agricultural exports and generate annually close to $450 million. This could be increased but for fruit flies that cause damage equivalent to 15% to 20% of present production value of fruit and also deny export access to countries imposing quarantine barriers. The Department of Technical Co-operation is sponsoring a programme, with technical support from the Joint FAO/IAEA Division, to eradicate the Mediterranean fruit fly using the Sterile Insect Technique (SIT). (IAEA)

  9. Control carrot fly

    van den Broek, Rob


    The larva of the carrot fly, Psila rosae, may in some umbelliferous plants cause significant damage. The insect is mainly in the temperate regions of the northern hemisphere, but also in some subtropical areas. Everywhere in the Netherlands where carrots are grown, is degradation. In the Netherlands organic growers seem well with the carrot fly problem to go, the number of reports of harm and disapproval is not too bad. With smart cultivation measures, the problems are manageable and, underst...

  10. A review on electrochemical double-layer capacitors

    Various energy storage technologies have been developed in the market for various applications. Batteries flywheels, fuel cells are a few which are much common, those are being used in several countries and also research is also carrying on these technologies to make much better them. The electrochemical double-layer capacitor (EDLC) is an emerging technology, which really plays a key part in fulfilling the demands of electronic devices and systems, for present and future. This paper presents the historical background, classification, construction, modeling, testing, and voltage balancing of the EDLC technology. The applications of EDLC in electrical vehicles, power quality, and others are also discussed and their advantages over other storages technologies are also discussed.

  11. Capacitor performance limitations in high power converter applications

    El-Khatib, Walid Ziad; Holbøll, Joachim; Rasmussen, Tonny Wederberg


    High voltage low inductance capacitors are used in converters as HVDC-links, snubber circuits and sub model (MMC) capacitances. They facilitate the possibility of large peak currents under high frequent or transient voltage applications. On the other hand, using capacitors with larger equivalent...... ratings and capacitances where investigated and compared a) on a component scale, characterizing the capacitors transient performance and b) as part of different converter applications, where the series inductance plays a role. In that way, better insight is achieved on how the capacitor construction can...... affect the total performance of the converter....

  12. Aging Methodologies and Prognostic Health Management for Electrolytic Capacitors

    National Aeronautics and Space Administration — Understanding the ageing mechanisms of electronic components critical avionics systems such as the GPS and INAV are of critical importance. Electrolytic capacitors...

  13. Cryogenic Capacitors for Low-Temperature Power Systems Project

    National Aeronautics and Space Administration — TRS Technologies proposes to develop low-temperature multilayer ceramic capacitors (MLCCs) capable of operating at cyrogenic temperatures (<77K). These...

  14. Accelerated Aging Experiments for Capacitor Health Monitoring and Prognostics

    National Aeronautics and Space Administration — This paper discusses experimental setups for health monitoring and prognostics of electrolytic capacitors under nominal operation and accelerated aging conditions....

  15. O fly, where art thou?

    Grover, Dhruv; Tower, John; Tavaré, Simon


    In this paper, the design of a real-time image acquisition system for tracking the movement of Drosophila in three-dimensional space is presented. The system uses three calibrated and synchronized cameras to detect multiple flies and integrates the detected fly silhouettes to construct the three-dimensional visual hull models of each fly. We used an extended Kalman filter to estimate the state of each fly, given past positions from the reconstructed fly visual hulls. The results show that our...

  16. Superoxide Dismutase (SOD)-mimetic M40403 Is Protective in Cell and Fly Models of Paraquat Toxicity

    Filograna, Roberta; Godena, Vinay K.; Sanchez-Martinez, Alvaro; Ferrari, Emanuele; Casella, Luigi; Beltramini, Mariano; Bubacco, Luigi; Whitworth, Alexander J.; Bisaglia, Marco


    Parkinson disease is a debilitating and incurable neurodegenerative disorder affecting ∼1–2% of people over 65 years of age. Oxidative damage is considered to play a central role in the progression of Parkinson disease and strong evidence links chronic exposure to the pesticide paraquat with the incidence of the disease, most probably through the generation of oxidative damage. In this work, we demonstrated in human SH-SY5Y neuroblastoma cells the beneficial role of superoxide dismutase (SOD) enzymes against paraquat-induced toxicity, as well as the therapeutic potential of the SOD-mimetic compound M40403. Having verified the beneficial effects of superoxide dismutation in cells, we then evaluated the effects using Drosophila melanogaster as an in vivo model. Besides protecting against the oxidative damage induced by paraquat treatment, our data demonstrated that in Drosophila M40403 was able to compensate for the loss of endogenous SOD enzymes, acting both at a cytosolic and mitochondrial level. Because previous clinical trials have indicated that the M40403 molecule is well tolerated in humans, this study may have important implication for the treatment of Parkinson disease. PMID:26953346

  17. Low-dimensional carbon and MXene-based electrochemical capacitor electrodes

    Yoon, Yeoheung; Lee, Keunsik; Lee, Hyoyoung


    Due to their unique structure and outstanding intrinsic physical properties such as extraordinarily high electrical conductivity, large surface area, and various chemical functionalities, low-dimension-based materials exhibit great potential for application in electrochemical capacitors (ECs). The electrical properties of electrochemical capacitors are determined by the electrode materials. Because energy charge storage is a surface process, the surface properties of the electrode materials greatly influence the electrochemical performance of the cell. Recently, graphene, a single layer of sp2-bonded carbon atoms arrayed into two-dimensional carbon nanomaterial, has attracted wide interest as an electrode material for electrochemical capacitor applications due to its unique properties, including a high electrical conductivity and large surface area. Several low-dimensional materials with large surface areas and high conductivity such as onion-like carbons (OLCs), carbide-derived carbons (CDCs), carbon nanotubes (CNTs), graphene, metal hydroxide, transition metal dichalcogenides (TMDs), and most recently MXene, have been developed for electrochemical capacitors. Therefore, it is useful to understand the current issues of low-dimensional materials and their device applications.

  18. Carbon-Based Materials for Lithium-Ion Batteries, Electrochemical Capacitors, and Their Hybrid Devices.

    Yao, Fei; Pham, Duy Tho; Lee, Young Hee


    A rapidly developing market for portable electronic devices and hybrid electrical vehicles requires an urgent supply of mature energy-storage systems. As a result, lithium-ion batteries and electrochemical capacitors have lately attracted broad attention. Nevertheless, it is well known that both devices have their own drawbacks. With the fast development of nanoscience and nanotechnology, various structures and materials have been proposed to overcome the deficiencies of both devices to improve their electrochemical performance further. In this Review, electrochemical storage mechanisms based on carbon materials for both lithium-ion batteries and electrochemical capacitors are introduced. Non-faradic processes (electric double-layer capacitance) and faradic reactions (pseudocapacitance and intercalation) are generally explained. Electrochemical performance based on different types of electrolytes is briefly reviewed. Furthermore, impedance behavior based on Nyquist plots is discussed. We demonstrate the influence of cell conductivity, electrode/electrolyte interface, and ion diffusion on impedance performance. We illustrate that relaxation time, which is closely related to ion diffusion, can be extracted from Nyquist plots and compared between lithium-ion batteries and electrochemical capacitors. Finally, recent progress in the design of anodes for lithium-ion batteries, electrochemical capacitors, and their hybrid devices based on carbonaceous materials are reviewed. Challenges and future perspectives are further discussed. PMID:26140707

  19. Peripheral Ferroelectric Domain Switching and Polarization Fatigue in Nonvolatile Memory Elements of Continuous Pt/SrBi2Ta2O9/Pt Thin-Film Capacitors

    We verify the domain sideway motion around the peripheral regions of the crossed capacitors of top and bottom electrode bars without electrode coverage. To avoid the crosstalk problem between adjacent memory cells, the safe distance between adjacent elements of Pt/SrBi2Ta2O9/Pt thin-film capacitors is estimated to be 0.156 μm. Moreover, the fatigue of Pt/SrBi2Ta2O9/Pt thin-film capacitors is independent of the individual memory size due to the absence of etching damage. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  20. Waveform digitization utilizing switched-capacitor arrays

    Compared with traditional waveform digitization with flash-ADCs, waveform digitization with switched-capacitor arrays (SCAs) is able to achieve the sampling speed above 1 GS/s without degrading the analog to digital conversion precision significantly. In this paper, we present the implementation of a fast waveform digitization system with the use of SCAs, and evaluate its performance of waveform digitization and the waveform timing. At about 5 GS/s, the dynamic input range of the digitizer is about 66 dB, and its timing precision is about 20 ps (RMS). (authors)

  1. Characterization of internal boundary layer capacitors

    Internal boundary layer capacitors were characterized by scanning transmission electron microscopy and by microscale electrical measurements. Data are given for the chemical and physical characteristics of the individual grains and boundaries, and their associated electric and dielectric properties. Segregated internal boundary layers were identified with resistivities of 1012-1013 Ω-cm. Bulk apparent dielectric constants were 10,000-60,000. A model is proposed to explain the dielectric behavior in terms of an equivalent n-c-i-c-n representation of ceramic microstructure, which is substantiated by capacitance-voltage analysis

  2. Polymer--Ionic liquid Electrolytes for Electrochemical Capacitors

    Ketabi, Sanaz

    Polymer electrolyte, comprised of ionic conductors, polymer matrix, and additives, is one of the key components that control the performance of solid flexible electrochemical capacitors (ECs). Ionic liquids (ILs) are highly promising ionic conductors for next generation polymer electrolytes due to their excellent electrochemical and thermal stability. Fluorinated ILs are the most commonly applied in polymer-IL electrolytes. Although possessing high conductivity, these ILs have low environmental favorability. The aim of this work was to develop environmentally benign polymer-ILs for both electrochemical double layer capacitors (EDLCs) and pseudocapacitors, and to provide insights into the influence of constituent materials on the ion conduction mechanism and the structural stability of the polymer-IL electrolytes. Solid polymer electrolytes composed of poly(ethylene oxide) (PEO) and 1-ethyl-3-methylimidazolium hydrogen sulfate (EMIHSO4) were investigated for ECs. The material system was optimized to achieve the two criteria for high performance polymer-ILs: high ionic conductivity and highly amorphous structure. Thermal and structural analyses revealed that EMIHSO4 acted as an ionic conductor and a plasticizer that substantially decreased the crystallinity of PEO. Two types of inorganic nanofillers were incorporated into these polymer electrolytes. The effects of SiO2 and TiO2 nanofillers on ionic conductivity, crystallinity, and dielectric properties of PEO-EMIHSO 4 were studied over a temperature range from -10 °C and 80 °C. Using an electrochemical capacitor model, impedance (complex capacitance) and dielectric analyses were performed to understand the ionic conduction process with and without fillers in both semi crystalline and amorphous states of the polymer electrolytes. Despite their different nanostructures, both SiO2 and TiO2 promoted an amorphous structure in PEO-EMIHSO 4 and increased the ionic conductivity 2-fold. While in the amorphous state, the

  3. Parkinson disease-linked GBA mutation effects reversed by molecular chaperones in human cell and fly models.

    Sanchez-Martinez, Alvaro; Beavan, Michelle; Gegg, Matthew E; Chau, Kai-Yin; Whitworth, Alexander J; Schapira, Anthony H V


    GBA gene mutations are the greatest cause of Parkinson disease (PD). GBA encodes the lysosomal enzyme glucocerebrosidase (GCase) but the mechanisms by which loss of GCase contributes to PD remain unclear. Inhibition of autophagy and the generation of endoplasmic reticulum (ER) stress are both implicated. Mutant GCase can unfold in the ER and be degraded via the unfolded protein response, activating ER stress and reducing lysosomal GCase. Small molecule chaperones that cross the blood brain barrier help mutant GCase refold and traffic correctly to lysosomes are putative treatments for PD. We treated fibroblast cells from PD patients with heterozygous GBA mutations and Drosophila expressing human wild-type, N370S and L444P GBA with the molecular chaperones ambroxol and isofagomine. Both chaperones increased GCase levels and activity, but also GBA mRNA, in control and mutant GBA fibroblasts. Expression of mutated GBA in Drosophila resulted in dopaminergic neuronal loss, a progressive locomotor defect, abnormal aggregates in the ER and increased levels of the ER stress reporter Xbp1-EGFP. Treatment with both chaperones lowered ER stress and prevented the loss of motor function, providing proof of principle that small molecule chaperones can reverse mutant GBA-mediated ER stress in vivo and might prove effective for treating PD. PMID:27539639

  4. Crystallization and preliminary X-ray analysis of the FliH–FliI complex responsible for bacterial flagellar type III protein export

    The FliH–FliI complex from the bacterial flagellar type III export apparatus has been expressed, purified and crystallized, and the crystals have been characterized by X-ray diffraction. The bacterial flagellar proteins are translocated into the central channel of the flagellum by a specific protein-export apparatus for self-assembly at the distal growing end. FliH and FliI are soluble components of the export apparatus and form an FliH2–FliI heterotrimer in the cytoplasm. FliI is an ATPase and the FliH2–FliI complex delivers export substrates from the cytoplasm to an export gate made up of six integral membrane proteins of the export apparatus. In this study, an FliHC fragment consisting of residues 99–235 was co-purified with FliI and the FliHC2–FliI complex was crystallized. Crystals were obtained using the hanging-drop vapour-diffusion technique with PEG 400 as a precipitant. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 133.7, b = 147.3, c = 164.2 Å, and diffracted to 3.0 Å resolution

  5. Functional genomics of the horn fly, Haematobia irritans (Linnaeus, 1758

    Quiroz-Romero Héctor


    Full Text Available Abstract Background The horn fly, Haematobia irritans (Linnaeus, 1758 (Diptera: Muscidae is one of the most important ectoparasites of pastured cattle. Horn flies infestations reduce cattle weight gain and milk production. Additionally, horn flies are mechanical vectors of different pathogens that cause disease in cattle. The aim of this study was to conduct a functional genomics study in female horn flies using Expressed Sequence Tags (EST analysis and RNA interference (RNAi. Results A cDNA library was made from whole abdominal tissues collected from partially fed adult female horn flies. High quality horn fly ESTs (2,160 were sequenced and assembled into 992 unigenes (178 contigs and 814 singlets representing molecular functions such as serine proteases, cell metabolism, mitochondrial function, transcription and translation, transport, chromatin structure, vitellogenesis, cytoskeleton, DNA replication, cell response to stress and infection, cell proliferation and cell-cell interactions, intracellular trafficking and secretion, and development. Functional analyses were conducted using RNAi for the first time in horn flies. Gene knockdown by RNAi resulted in higher horn fly mortality (protease inhibitor functional group, reduced oviposition (vitellogenin, ferritin and vATPase groups or both (immune response and 5'-NUC groups when compared to controls. Silencing of ubiquitination ESTs did not affect horn fly mortality and ovisposition while gene knockdown in the ferritin and vATPse functional groups reduced mortality when compared to controls. Conclusions These results advanced the molecular characterization of this important ectoparasite and suggested candidate protective antigens for the development of vaccines for the control of horn fly infestations.

  6. Development of a Fruit Fly Strain for Sterile Fly Detection

    Full text: A white-striped oriental fruit fly strain, derived from hot-water treated eggs, was developed for sterile fly detection. It was applied to evaluate the effectiveness of fruit fly population control by releasing the radiation induced sterile flies. The objectives of this reported set of experiments were to study the effects of mass rearing on the quality of white-striped oriental fruit flies, the effectiveness of controlling the wild fly population and the accuracy of detection of the released white-striped flies. It was found that mass rearing decreased the pupal yield but increased the pupal quality of white-striped flies comparing with normal flies. Controlling the wild fruit fly population by releasing sterile white-striped flies integrated with other control methods at Tambon Trok Nong, Amphoe Khlung, Chanthaburi Province, could suppress the wild fruit fly population by 96.02 %. The use of white-striped oriental fruit flies yielded a higher detection accuracy upon releasing and reduced the operating time and costs when compared with the use of fluorescent dye marking approach

  7. Evaluation of high temperature capacitor dielectrics

    Hammoud, Ahmad N.; Myers, Ira T.

    Experiments were carried out to evaluate four candidate materials for high temperature capacitor dielectric applications. The materials investigated were polybenzimidazole polymer and three aramid papers: Voltex 450, Nomex 410, and Nomex M 418, an aramid paper containing 50 percent mica. The samples were heat treated for six hours at 60 C and the direct current and 60 Hz alternating current breakdown voltages of both dry and impregnated samples were obtained in a temperature range of 20 to 250 C. The samples were also characterized in terms of their dielectric constant, dielectric loss, and conductivity over this temperature range with an electrical stress of 60 Hz, 50 V/mil present. Additional measurements are underway to determine the volume resistivity, thermal shrinkage, and weight loss of the materials. Preliminary data indicate that the heat treatment of the films slightly improves the dielectric properties with no influence on their breakdown behavior. Impregnation of the samples leads to significant increases in both alternating and direct current breakdown strength. The results are discussed and conclusions made concerning their suitability as high temperature capacitor dielectrics.

  8. Capacitors Would Help Protect Against Hypervelocity Impacts

    Edwards, David; Hubbs, Whitney; Hovater, Mary


    A proposal investigates alternatives to the present bumper method of protecting spacecraft against impacts of meteoroids and orbital debris. The proposed method is based on a British high-voltage-capacitance technique for protecting armored vehicles against shaped-charge warheads. A shield, according to the proposal, would include a bare metal outer layer separated by a gap from an inner metal layer covered with an electrically insulating material. The metal layers would constitute electrodes of a capacitor. A bias potential would be applied between the metal layers. A particle impinging at hypervelocity on the outer metal layer would break apart into a debris cloud that would penetrate the electrical insulation on the inner metal layer. The cloud would form a path along which electric current could flow between the metal layers, thereby causing the capacitor to discharge. With proper design, the discharge current would be large enough to vaporize the particles in the debris cloud to prevent penetration of the spacecraft. The shield design can be mass optimized to be competitive with existing bumper designs. Parametric studies were proposed to determine optimum correction between bias voltage, impacting particle velocity, gap space, and insulating material required to prevent spacecraft penetration.

  9. Hydrogel membrane electrolyte for electrochemical capacitors

    S Sampath; N A Choudhury; A K Shukla


    Polymer electrolytes are known to possess excellent physicochemical properties that are very useful for electrochemical energy systems. The mobility in polymer electrolytes is understood to be mainly due to the segmental motion of polymer chains and the ion transport is generally restricted to the amorphous phase of the polymer. Gel polymer electrolytes (GPE) that are formed using plastizicers and polymers along with ionic salts are known to exhibit liquid-like ionic conductivity while maintaining the dimensional stability of a solid matrix. In the present study, the preparation and characterization of poly(vinyl alcohol)-based hydrogel membranes (PHMEs) as electrolytes for electrochemical capacitors have been reported. Varying HClO4 dopant concentration leads to different characteristics of the capacitors. The EC comprising PHME doped with 2 M HClO4 and black pearl carbon (BPC) electrodes has been found to exhibit a maximum specific capacitance value of 97 F g-1, a phase angle value of 78°, and a maximum charge-discharge coulombic efficiency of 88%.

  10. High-Efficiency Self-Adjusting Switched Capacitor DC-DC Converter with Binary Resolution

    Kushnerov, Alexander


    Switched-Capacitor Converters (SCC) suffer from a fundamental power loss deficiency which make their use in some applications prohibitive. The power loss is due to the inherent energy dissipation when SCC operate between or outside their output target voltages. This drawback was alleviated in this work by developing two new classes of SCC providing binary and arbitrary resolution of closely spaced target voltages. Special attention is paid to SCC topologies of binary resolution. Namely, SCC systems that can be configured to have a no-load output to input voltage ratio that is equal to any binary fraction for a given number of bits. To this end, we define a new number system and develop rules to translate these numbers into SCC hardware that follows the algebraic behavior. According to this approach, the flying capacitors are automatically kept charged to binary weighted voltages and consequently the resolution of the target voltages follows a binary number representation and can be made higher by increasing t...

  11. Direct Mismatch Characterization of femto-Farad Capacitors

    Omran, Hesham


    Reducing the capacitance of programmable capacitor arrays, commonly used in analog integrated circuits, is necessary for low-energy applications. However, limited mismatch data is available for small capacitors. We report mismatch measurement for a 2fF poly-insulator-poly (PIP) capacitor, which is the smallest reported PIP capacitor to the best of the authors’ knowledge. Instead of using complicated custom onchip circuitry, direct mismatch measurement is demonstrated and verified using Monte Carlo Simulations and experimental measurements. Capacitive test structures composed of 9 bit programmable capacitor arrays (PCAs) are implemented in a low-cost 0:35m CMOS process. Measured data is compared to mismatch of large PIP capacitors, theoretical models, and recently published data. Measurement results indicate an estimated average relative standard deviation of 0.43% for the 2fF unit capacitor, which is better than the reported mismatch of metal-oxide-metal (MOM) fringing capacitors implemented in an advanced 32nm CMOS process.

  12. Metallized Film Capacitor Lifetime Evaluation and Failure Mode Analysis

    Gallay, R


    One of the main concerns for power electronic engineers regarding capacitors is to predict their remaining lifetime in order to anticipate costly failures or system unavailability. This may be achieved using a Weibull statistical law combined with acceleration factors for the temperature, the voltage, and the humidity. This paper discusses the different capacitor failure modes and their effects and consequences.

  13. Physics based Degradation Modeling and Prognostics of Electrolytic Capacitors under Electrical Overstress Conditions

    National Aeronautics and Space Administration — This paper proposes a physics based degradation modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors are critical components in...

  14. Prognostics Health Management and Physics based failure Models for Electrolytic Capacitors

    National Aeronautics and Space Administration — This paper proposes first principles based modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors and MOSFETs are the two major...

  15. Design of electric capacitor bank of electrical system

    Capacitor bank is a electrical equipment which can the function to compensating the line reactive power in that reactive power such reduced and angle between voltage and current is small. Principle of this capacitor bank can compensating the reactive power in which that reduction reactive power and the electric power factor can be improved. With of use the this capacitor bank . can improvement the electric power factor of electrical system in building 70 and 71. In this design, amount of the apparent power 1400 KVAR required two the capacitor capacity 150 KVAR which installed low voltage switchgear A and low voltage switchgear B as figure 4 can to improve the electric power factor of electric system of 0, 82 up to 0,87. With this improve of electric power can increased voltage of 360 volt up to 370 volt. In both capacitor bank such to installed parallel with load which installed on low voltage switchgear A and B. (author)

  16. A capacitor charging power supply using series resonant topology

    A capacitor charging power supply has to perform under wide range of load variations. Initially the capacitor will act as a short circuit so the topology must be such that it should withstand short circuit condition repetitively. This power supply has been specially developed using series resonant topology for capacitor charging applications. The capacitor charging power supply (CCPS) will charge a 100 uF energy storage capacitor from 0V to 600V in 35 ms exhibiting a charging power of 514.28 J/s at a repetition rate of 25 Hz. Topology selection is based on the fact that the series resonant converter with switching frequency below 50% of the resonant frequency (fs r) act as a current source. (author)

  17. Absorption Voltages and Insulation Resistance in Ceramic Capacitors with Cracks

    Teverovsky, Alexander


    Time dependence of absorption voltages (Vabs) in different types of low-voltage X5R and X7R ceramic capacitors was monitored for a maximum duration of hundred hours after polarization. To evaluate the effect of mechanical defects on Vabs, cracks in the dielectric were introduced either mechanically or by thermal shock. The maximum absorption voltage, time to roll-off, and the rate of voltage decrease are shown to depend on the crack-related leakage currents and insulation resistance in the parts. A simple model that is based on the Dow equivalent circuit for capacitors with absorption has been developed to assess the insulation resistance of capacitors. Standard measurements of the insulation resistance, contrary to the measurements based on Vabs, are not sensitive to the presence of mechanical defects and fail to reveal capacitors with cracks. Index Terms: Ceramic capacitor, insulation resistance, dielectric absorption, cracking.

  18. Quality inspection on electrolytic capacitors using micro-computed tomography

    Pratama, I. B. G. P.; Suparta, Gede B.


    A set of electrolyte capacitors were inspected using x-ray micro-computed tomography (μ-CT) system developed at the Department of Physics Gadjah Mada University, Indonesia. Testing was done for three electrolyte capacitors. The one is in good condition and the other two are considered broken. Those were broken due to either high voltage operation or leakage of the tube. Under customized μ-CT inspection, 3-D presentations of the objects have been developed. The results showed that the image profiles, radiation attenuation profiles and linear attenuation coefficient distribution on top, middle and bottom area were able to determine the aluminum plate and electrolyte papers. Good electrolyte capacitor has higher radiation attenuation and nearly uniform across the core of the capacitor. This is in contrast with the broken capacitors.

  19. Evaluation of Commercial Automotive-Grade BME Capacitors

    Liu, Donhang


    Three Ni-BaTiO3 ceramic capacitor lots with the same specification (chip size, capacitance, and rated voltage) and the same reliability level, made by three different manufacturers, were degraded using highly accelerated life stress testing (HALST) with the same temperature and applied voltage conditions. The reliability, as characterized by mean time to failure (MTTF), differed by more than one order of magnitude among the capacitor lots. A theoretical model based on the existence of depletion layers at grain boundaries and the entrapment of oxygen vacancies has been proposed to explain the MTTF difference among these BME capacitors. It is the conclusion of this model that reliability will not be improved simply by increasing the insulation resistance of a BME capacitor. Indeed, Ni-BaTiO3 ceramic capacitors with a smaller degradation rate constant K will always give rise to a longer reliability life.

  20. Advanced Wet Tantalum Capacitors: Design, Specifications and Performance

    Teverovsky, Alexander


    Insertion of new types of commercial, high volumetric efficiency wet tantalum capacitors in space systems requires reassessment of the existing quality assurance approaches that have been developed for capacitors manufactured to MIL-PRF-39006 requirements. The specifics of wet electrolytic capacitors is that leakage currents flowing through electrolyte can cause gas generation resulting in building up of internal gas pressure and rupture of the case. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. This presentation gives a review of specifics of the design, performance, and potential reliability risks associated with advanced wet tantalum capacitors. Problems related to setting adequate requirements for DPA, leakage currents, hermeticity, stability at low and high temperatures, ripple currents for parts operating in vacuum, and random vibration testing are discussed. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  1. Autonomous Flying Controls Testbed

    Motter, Mark A.


    The Flying Controls Testbed (FLiC) is a relatively small and inexpensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches. The most recent version of the FLiC is configured with 16 independent aileron segments, supports the implementation of C-coded experimental controllers, and is capable of fully autonomous flight from takeoff roll to landing, including flight test maneuvers. The test vehicle is basically a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate (AATD) at Fort Eustis,Virginia and NASA Langley Research Center. Several vehicles have been constructed and collectively have flown over 600 successful test flights.

  2. Mutually repressing repressor functions and multi-layered cellular heterogeneity regulate the bistable Salmonella fliC census

    Stewart, Mary K.; Cookson, Brad T.


    Summary Bistable flagellar and virulence gene expression generates specialized Salmonella subpopulations with distinct functions. Repressing flagellar genes allows Salmonella to evade caspase-1 mediated host defenses and enhances systemic colonization. By definition, bistability arises when intermediate states of gene expression are rendered unstable by the underlying genetic circuitry. We demonstrate sustained bistable fliC expression in virulent Salmonella 14028 and document dynamic control of the distribution, or single-cell census, of flagellar gene expression by the mutually repressing repressors YdiV and FliZ. YdiV partitions cells into the fliC-OFF subpopulation, while FliZ partitions cells into the fliC-HIGH subpopulation at late timepoints during growth. Bistability of ΔfliZ populations and ydiV-independent FliZ control of flagellar gene expression provide evidence that the YdiV-FliZ mutually repressing repressor circuit is not required for bistability. Repression and activation by YdiV and FliZ (respectively) can shape the census of fliC expression independently, and bistability collapses into a predominantly intermediate population in the absence of both regulators. Metered expression of YdiV and FliZ reveals variable sensitivity to these regulators and defines conditions where expression of FliZ enhances fliC expression and where FliZ does not alter the fliC census. Thus, this evolved genetic circuitry coordinates multiple layers of regulatory heterogeneity into a binary response. PMID:25315056

  3. A Novel Flying Capacitor Transformerless Inverter for Single-Phase Grid Connected Solar Photovoltaic System

    Siwakoti, Yam Prasad; Blaabjerg, Frede


    connected to the grid, so no leakage current, (2) voltage stress of all switches are same and equal to the dc-link voltage, (3) reactive power can be send to grid, so no problem of reactive power compensation (4) peak of output ac voltage is equal to input dc-voltage (unlike bridge and NPC type which...... requires two times of the peak ac-voltage magnitude). This property can potentially replace industry standard conventional H-bridge single phase inverter with this new topology for any application especially for motor drives. In addition, industry standard half bridge module can be implemented in the new...

  4. Solid State Transformer Based on the Flying Capacitor Multilevel Converter for Intelligent Power Management

    Ghias, Amer M.Y.M.; Ciobotaru, M.; Agelidis, Vassilios; Pou Félix, Josep


    Future grids will consist of large scale of integration of both renewable and other distributed energy sources. Therefore, advanced power electronics converters for critical loads will be needed in order to enhance power quality, and to ensure proper and secure operation of future grids. These power converters must be able to provide intelligent power management as well as ancillary services. This paper proposes a solid state transformer (SST) which consists of medium fre...

  5. Complexity and Fly Swarms

    Cates, Grant; Murray, Joelle

    Complexity is the study of phenomena that emerge from a collection of interacting objects and arises in many systems throughout physics, biology, finance, economics and more. Certain kinds of complex systems can be described by self-organized criticality (SOC). An SOC system is one that is internally driven towards some critical state. Recent experimental work suggests scaling behavior of fly swarms-one of the hallmarks of an SOC system. Our goal is to look for SOC behavior in computational models of fly swarms.

  6. Sustainable AC/AC hybrid electrochemical capacitors in aqueous electrolyte approaching the performance of organic systems

    Abbas, Qamar; Babuchowska, Paulina; Frąckowiak, Elżbieta; Béguin, François


    A high energy hybrid AC/AC electrochemical capacitor has been realized in aqueous Li2SO4+KI electrolyte mixture. Owing to the redox processes associated with the 2I-/I2 system, the positive electrode operates in narrow potential range and displays high capacity. During prolonged potentiostatic floating at 1.6 V, the hybrid cell demonstrates remarkably stable capacitance and resistance. Analyses by temperature programmed desorption after floating at 1.6 V proved that oxidation of the positive AC electrode is prevented by the use of Li2SO4+KI, which enables the maximum potential of this electrode to be shifted below the water oxidation potential. When charged at 0.2 A g-1 up to U = 1.6 V, the hybrid cell displays a high capacitance of 75 F g-1 (300 F g-1 per mass of one electrode) compared to 47 F g-1 (188 F g-1 per mass of one electrode) for a symmetric cell in Li2SO4. At 0.2 A g-1 up to 1.6 V, the hybrid capacitor in Li2SO4+KI displays an energy density of 26 Wh kg-1 which approaches the energy density of 30.9 Wh kg-1 measured when the same carbon is implemented in a capacitor using TEABF4/ACN electrolyte and charged up to 2.5 V.

  7. The elastic capacitor and its unusual properties

    Partensky, M B


    The 'elastic capacitor' (EC) model was first introduced in studies of lipid bilayers (the major components of biological membranes). This electro-elastic model accounted for the compression of a membrane under applied voltage and allowed obtaining information about the membrane's elastic properties from the measurements of its capacitance. Later on, ECs were used to analyze the electrical breakdown of biological membranes. The EC model was also helpful in studies of electric double layers in various electrified interfaces (of which the electrode/ electrolyte interface is the most common example). This comparatively simple model, which analysis requires only high-school physics, has a close relationship to some real-life problems in physics, chemistry and biology. I hope that both teachers and students will find its discussion interesting, challenging and instructive.

  8. Flake tantalum powder for manufacturing electrolytic capacitors

    HE Jilin; YANG Guoqi; PAN Luntao; LIU Hongdong; BAO Xifang


    The FTP200 flake tantalum powder was introduced.The microstructures of the powder with leaf-like primary particles having an average flakiness of 2 to 20 and porous agglomerated particles were observed.The chemical composition,physical properties,and electrical properties of the FTP200 powder were compared with those of the FTW300 nodular powder.The FTP200 powder is more sinter-resistant,and the surface area of the flake tantalum powder under sintering at high temperature has less loss than that of the nodular tantalum powder.The specific capacitance of the flake tantalum powder is higher than that of the nodular tantalum powder with the same surface area when anodized at high voltage,Thus,the flake tantalum powder is suitable for manufacturing tantalum solid electrolytic capacitors in the range of median and high (20-63 V) voltages.

  9. Breakdown properties of irradiated MOS capacitors

    The authors have studied the effects of ionizing and non-ionizing radiation on the breakdown properties of different types of MOS capacitors, with thick (200 nm) and thin (down to 8 nm) oxides. In general, no large variations of the average breakdown field, time-to-breakdown at constant voltage, or charge-to-breakdown at constant voltage, or charge-to-breakdown values have been observed after high dose irradiation (20 Mrad(Si) 9 MeV electrons on thin and thick oxides, 17(Si) Mrad Co60 gamma and 1014 neutrons/cm2 only on thick oxides). However, some modifications of the cumulative failure distributions have been observed in few of the oxides tested

  10. Charge fluctuations in nano-scale capacitors

    Limmer, David T; Salanne, Mathieu; Chandler, David; Madden, Paul A; van Roij, René; Rotenberg, Benjamin


    The fluctuations of the charge on an electrode contain information on the microscopic correlations within the adjacent fluid and their effect on the electronic properties of the interface. We investigate these fluctuations using molecular dynamics simulations in a constant-potential ensemble with histogram reweighting techniques. This approach offers an efficient and accurate route to the differential capacitance and is broadly applicable. We demonstrate these methods with three different capacitors: pure water between platinum electrodes, and a pure as well as a solvent-based organic electrolyte each between graphite electrodes. The total charge distributions with the pure solvent and solvent-based electrolytes are remarkably Gaussian, while in the pure ionic liquid the total charge distribution displays distinct non-Gaussian features, suggesting significant potential-driven changes in the organization of the interfacial fluid.

  11. Fly on the Wall

    Berry, Dave; Korpan, Cynthia


    This paper describes the implementation of a peer observation program at the University of Victoria called the Lecture Club. The observers are not interactive during the class--they are the proverbial flies on the wall. The paper identifies the program as self-developmental, discussing the attributes of this learning-to-teach and peer-sharing…

  12. Ageing behaviour of electrochemical double layer capacitors. Part II. Lifetime simulation model for dynamic applications

    Bohlen, Oliver; Kowal, Julia; Dirk Uwe Sauer [Institute for Power Electronics and Electrical Drives ISEA, RWTH Aachen University, Aachen (Germany)


    Based on the results of the experimental study in Part I, a holistic simulation model that combines electrical and thermal simulation of electrochemical double-layer capacitor (EDLC) modules with an ageing model is presented. This simulation model allows analysing self-accelerating degradation effects caused by elevated voltages and temperatures. Furthermore, the divergence of cell performance in a stack of cells can be investigated which makes the model a valuable tool for cell and stack design as well as for testing operating strategies and cooling systems. (author)

  13. Defibrillation thresholds are lower with smaller storage capacitors.

    Leonelli, F M; Kroll, M W; Brewer, J E


    Present implantable cardioverter defibrillators use a wide range of capacitance values for the storage capacitor. However, the optimal capacitance value is unknown. We hypothesized that a smaller capacitor, by delivering its charge in a time closer to the heart chronaxie, should lower the defibrillation threshold (DFT). We compared the energy required to defibrillate 10 open-chest dogs, after 15 seconds of ventricular fibrillation, with a monophasic, time-truncated waveform delivered from either a 85-microF or a 140-microF capacitor. Shocks were delivered through a pair of 14-cm2 epicardial patch electrodes: The two capacitors were randomly tested twice with each dog using a modified 3-reversal method for each DFT determination. The average stored and delivered DFT energies for the 85-microF capacitor were 6.0 +/- 1.7 joules and 5.2 +/- 1.5 joules, respectively, compared to 6.7 +/- 1.7 joules and 6.0 +/- 1.5 joules for the 140-microF capacitor (P = 0.01 and P = 0.004, respectively). The mean leading edge voltages were higher, the pulse duration shorter, and the mean impedance lower for the 85-microF capacitor. The impedance was inversely related to the pulse duration and the voltage decay suggesting that, at least in part, the mechanism of improved defibrillation could be accounted for by the waveform electrical characteristics. There was an equal number of episodes of postshock bradyarrhythmias and tachyarrhythmias following discharges from each capacitor. Moreover, there was no relationship between the likelihood of these arrhythmias and either the initial voltage or the delivered current nor there was a higher number of episodes of postshock hypotension following the smaller capacitor discharges.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7491309

  14. Development of High Temperature Capacitor Technology and Manufacturing Capability

    None, None


    The goal of the Development of High Temperature Capacitor Technology and Manufacturing Capability program was to mature a production-ready supply chain for reliable 250°C FPE (fluorinated polyester) film capacitors by 2011. These high-temperature film capacitors enable both the down hole drilling and aerospace industries by enabling a variety of benefits including: - Deeper oil exploration in higher temperature and pressure environments - Enabling power electronic and control equipment to operate in higher temperature environments - Enabling reduced cooling requirements of electronics - Increasing reliability and life of capacitors operating below rated temperature - Enabling capacitors to handle higher electrical losses without overheating. The key challenges to bringing the FPE film capacitors to market have been manufacturing challenges including: - FPE Film is difficult to handle and wind, resulting in poor yields - Voltage breakdown strength decreases when the film is wound into capacitors (~70% decrease) - Encapsulation technologies must be improved to enable higher perature operation - Manufacturing and test cycle time is very long As a direct result of this program most of the manufacturing challenges have been met. The FPE film production metalization and winding yield has increased to over 82% from 70%, and the voltage breakdown strength of the wound capacitors has increased 270% to 189 V/μm. The high temperature packaging concepts are showing significant progress including promising results for lead attachments and hermetic packages at 200°C and non-hermetic packages at 250°C. Manufacturing and test cycle time will decrease as the market for FPE capacitors develops.

  15. Drug-mediated inhibition of Fli-1 for the treatment of leukemia

    The Ets transcription factor, Fli-1 is activated in murine erythroleukemia and overexpressed in various human malignancies including Ewing's sarcoma, induced by the oncogenic fusion protein EWS/Fli-1. Recent studies by our group and others have demonstrated that Fli-1 plays a key role in tumorigenesis, and disrupting its oncogenic function may serve as a potential treatment option for malignancies associated with its overexpression. Herein, we describe the discovery of 30 anti-Fli-1 compounds, characterized into six functional groups. Treatment of murine and human leukemic cell lines with select compounds inhibits Fli-1 protein or mRNA expression, resulting in proliferation arrest and apoptosis. This anti-cancer effect was mediated, at least in part through direct inhibition of Fli-1 function, as anti-Fli-1 drug treatment inhibited Fli-1 DNA binding to target genes, such as SHIP-1 and gata-1, governing hematopoietic differentiation and proliferation. Furthermore, treatment with select Fli-1 inhibitors revealed a positive relationship between the loss of DNA-binding activity and Fli-1 phosphorylation. Accordingly, anti-Fli-1 drug treatment significantly inhibited leukemogenesis in a murine erythroleukemia model overexpressing Fli-1. This study demonstrates the ability of this drug-screening strategy to isolate effective anti-Fli-1 inhibitors and highlights their potential use for the treatment of malignancies overexpressing this oncogene

  16. Comb-Line Filter with Coupling Capacitor in Ground Plane

    Toshiaki Kitamura


    Full Text Available A comb-line filter with a coupling capacitor in the ground plane is proposed. The filter consists of two quarter-wavelength microstrip resonators. A coupling capacitor is inserted into the ground plane in order to build strong coupling locally along the resonators. The filtering characteristics are investigated through numerical simulations as well as experiments. Filtering characteristics that have attenuation poles at both sides of the passband are obtained. The input susceptances of even and odd modes and coupling coefficients are discussed. The filters using stepped impedance resonators (SIRs are also discussed, and the effects of the coupling capacitor for an SIR structure are shown.

  17. Fission fragment detector by thin film capacitors. Pt. 2

    Fission fragments produce current pulses in thin film capacitors at applied electric fields lower than those required for the induction of breakdowns by such charged particles. This paper describes the use of silicon dioxide capacitors for the detection of fission fragments by these current pulses. With capacitor areas of 2 x 10-2 cm2, the pulses are not detectable when the oxide is relatively thin, but with 3,800 A thick oxide, fission fragments produce pulses of about 10-15C. The mechanisms producing the current pulses by fission fragments are finally discussed. (orig.)

  18. Hybridization of lithium-ion batteries and electrochemical capacitors: fabrication and challenges

    Agrawal, Richa; Hao, Yong; Song, Yin; Chen, Chunhui; Wang, Chunlei


    Conventional electrochemical double-layer capacitors (EDLCs) are well suited as power sources for devices that require large bursts of energy in short time periods. However, when compared to their battery counterparts, EDLCs suffer from low energy densities. The low energy density of EDLCs hinders their applications in devices that require a simultaneous supply of high power and high energy. In order to improve the energy density of EDLCs, the concept of hybridization of lithium-ion batteries (LIBs) and EDLCs has gathered much attention in past years. Such a hybrid is typically referred to as "lithium-ion capacitor" (LIC) or "lithium capacitor" and essentially utilizes a lithium intercalating anode (such as graphite or Li4Ti5O12) and a fast charging-discharging EDLC electrode (such as activated carbon, carbon nanostructures) in a lithium-salt based electrolyte. Although such a system sounds quite ideal in theory, there are major challenges that need to be addressed in order to fully realize the benefits of LIB and EDLC electrodes in conjunction. Most of these challenges stem from the mismatch in capacity of the electrodes and also the charging-discharging times of the electrodes. For instance, the EDLC electrode acts as the limiting factor for the capacity of the system while the LIB electrode limits the power of the system. Here we have fabricated a hybrid capacitor that utilizes a Li4Ti5O12 (LTO) based anode and an activated carbon (AC) composite based cathode. Half-cell testing for both LTO and AC have been shown along with full cell evaluation.

  19. Finite element analysis of underwater capacitor micromachined ultrasonic transducers.

    Roh, Yongrae; Khuri-Yakub, Butrus T


    A simple electro-mechanical equivalent circuit model is used to predict the behavior of capacitive micromachined ultrasonic transducers (cMUT). Most often, cMUTs are made in silicon and glass plates that are in the 0.5 mm to 1 mm range in thickness. The equivalent circuit model of the cMUT lacks important features such as coupling to the substrate and the ability to predict cross-talk between elements of an array of transducers. To overcome these deficiencies, a flnite element model of the cMUT is constructed using the commercial code ANSYS. Calculation results of the complex load impedance seen by single capacitor cells are presented, then followed by a calculation of the plane wave real load impedance seen by a parallel combination of many cells that are used to make a transducer. Cross-talk between 1-D array elements is found to be due to two main sources: coupling through a Stoneley wave propagating at the transducer-water interface and coupling through Lamb waves propagating in the substrate. To reduce the cross-talk level, the effect of structural variations of the substrate are investigated, which includes a change of its thickness and etched trenches or polymer walls between array elements. PMID:12322877

  20. Candida albicans Cas5, a Regulator of Cell Wall Integrity, Is Required for Virulence in Murine and Toll Mutant Fly Models

    Chamilos, Georgios; Nobile, Clarissa J.; Bruno, Vincent M.; Lewis, Russell E.; Mitchell, Aaron P.; Kontoyiannis, Dimitrios P.


    Candida albicans is the most common human fungal pathogen, yet the pathogenesis of C. albicans infection remains incompletely understood. We hypothesized that C. albicans has developed evolutionarily conserved mechanisms to invade disparate hosts and tested whether Toll mutant flies could serve as a model host for high-throughput screening of C. albicans virulence genes. We screened 34 C. albicans mutants defective in putative transcription factor genes (see

  1. Test What You Fly?

    Margolies, Don


    It was the first time on any NASA project I know of that all the instruments on an observatory came off for rework or calibration after the full range of environmental tests, and then were reintegrated at the launch center without the benefit of an observatory environmental retest. Perhaps you've heard the expression, 'Test what you fly, fly what you test'? In theory, it's hard to argue with that. In this case, I was willing to take the risk of not testing what I flew. As the project manager for the Advanced Composition Explorer (ACE) mission, I was the one who ultimately decided what risks to take, just as it was my responsibility to get buy-in from the stakeholders.

  2. Destructive tests on low voltage metallized polypropylene capacitors

    Cesari, S.


    This paper gives the results of destructive tests conducted on low voltage capacitors with metallized polypropylene dielectrics of the dry and impregnated types. The purpose of the tests was to check the behaviour of capacitors of the self-healing type in the event of a dielectric failure. A failure in the self-healing process of metallized polypropylene capacitors is usually accompanied by an increase in inside pressure which can cause the explosion in the casing if the capacitor is not equipped with a proper safety device. The tests were performed in accordance with ENEL (Italian Electricity Board) specifications. The effects of different test parameters, such as dielectric temperature and short-circuit current, were investigated and the results of the experiments were compared with those obtained in service and during service life tests.

  3. Electric Double-layer Capacitor Based on Activated Carbon Material


    In this study electric double-layer capacitors (EDLCs) based on activated carbon material and organic electrolyte (tetraethyl ammonium tetrafluoroborate) were explored. The fabrication method for EDLC is presented and the performance of EDLC was examined by using the cyclic voltammetry, constant-current charging and discharging technique, electrochemical impedance spectroscopy measurements. Influence of various components and design parameters on the performance of the capacitors were preliminarily investigated. Up to now, EDLC based on carbon materials can deliver 20.7 W/kg at the discharge rate ofI=0.3 mA, together with the energy density of 8.5 Wh/kg. Equivalent series resistance (ESR) is 0.716 Ω.cm2. The specific power of the capacitor is low and further attempts to raise the power capability of the capacitors are necessary. Some considerations are put forward to further improve the performance of EDLC.


    Patsiuk V.I.


    The class of nonstationary problems about the moving electric capacitor discharge on the long-distance transmission line is solved by means of characteristics method. The different velocities of the capacitor’s motion are considered.

  5. Improvement program for polycarbonate capacitors. [hermetically sealed, and ac wound

    Bailey, R. R.; Waterman, K. D.


    Hermetically sealed, wound, AC, polycarbonate capacitors incorporating design improvements recommended in a previous study were designed and built. A 5000 hour, 400 Hz ac life test was conducted using 384 of these capacitors to verify the adequacy of the design improvements. The improvements incorporated in the capacitors designed for this program eliminated the major cause of failure found in the preceding work, termination failure. A failure cause not present in the previous test became significant in this test with capacitors built from one lot of polycarbonate film. The samples from this lot accounted for 25 percent of the total test complement. Analyses of failed samples showed that the film had an excessive solvent content. This solvent problem was found in 37 of the total 46 failures which occurred in this test. The other nine were random failures resulting from causes such as seal leaks, foreign particles, and possibly wrinkles.

  6. Fringe Capacitance of a Parallel-Plate Capacitor.

    Hale, D. P.


    Describes an experiment designed to measure the forces between charged parallel plates, and determines the relationship among the effective electrode area, the measured capacitance values, and the electrode spacing of a parallel plate capacitor. (GA)

  7. Barium titanate nanocomposite capacitor FY09 year end report.

    Stevens, Tyler E.; DiAntonio, Christopher Brian; Yang, Pin; Chavez, Tom P.; Winter, Michael R.; Monson, Todd C.; Roesler, Alexander William; Fellows, Benjamin D.


    This late start RTBF project started the development of barium titanate (BTO)/glass nanocomposite capacitors for future and emerging energy storage applications. The long term goal of this work is to decrease the size, weight, and cost of ceramic capacitors while increasing their reliability. Ceramic-based nanocomposites have the potential to yield materials with enhanced permittivity, breakdown strength (BDS), and reduced strain, which can increase the energy density of capacitors and increase their shot life. Composites of BTO in glass will limit grain growth during device fabrication (preserving nanoparticle grain size and enhanced properties), resulting in devices with improved density, permittivity, BDS, and shot life. BTO will eliminate the issues associated with Pb toxicity and volatility as well as the variation in energy storage vs. temperature of PZT based devices. During the last six months of FY09 this work focused on developing syntheses for BTO nanoparticles and firing profiles for sintering BTO/glass composite capacitors.

  8. Fission fragment detector by thin film capacitors. Pt. 1

    Heavy ion detection by solid dielectrics has been so far obtained by chemical etching. In this paper the detection of fission fragments is based on the counting of breakdowns in thin films of solid dielectries. These films are used as dielectric materials in capacitors with one electrode usually less than 1000 A thick. Breakdowns in such capacitors are non-shorting and can be sometimes repeated up to millions of times per cm2 of the capacitor area. The property that makes these capacitors suited for detection is that fission fragments induce breakdowns at fields distinctly lower than those due to the application of field only. The characteristics of these new detecting systems are described and compared with those of the damage track detectors. (orig.)

  9. Prognostic Techniques for Capacitor Degradation and Health Monitoring

    National Aeronautics and Space Administration — This paper discusses our initial efforts in constructing physics of failure models for electrolytic capacitors subjected to electrical stressors in DC-DC power...

  10. Nanocurrent oscillator indefinitely powered by a capacitor battery

    Ragni, Luigi


    Some electrolytic capacitors show dielectric behaviour that can not be entirely explained by the well known long lasting relaxation. Extra charges able to generate a useful conduction current can be detected for an indefinite time. A squarewave oscillator based on MOSFET CMOS technology and requiring less than 2 nW was powered for 80 days at 25 {\\deg}C by a 58.2 mF capacitor battery, without voltage decrease during the last 53 days of observation. The battery consisted of three series of 16 parallel, 15 years aged, capacitors with DC capacitance of 10.9 mF. Capacitors so old, stored without voltage application, were affected by degradation and thinning of the alumina layer that could promote tunnelling of the charge. The main purpose of the present study is to stimulate further investigations aimed at confirming or disputing the observed phenomenon and, if necessary, at shedding light on its physical mechanisms.

  11. Flying Saucer? Aliens?


    No, it's not a flying saucer, it is the domed top to a 70 foot long vacuum tank at the Lewis Research Center's Electric Propulsion Laboratory, Cleveland, Ohio. The three technicians shown here in protective clothing had just emerged from within the tank where they had been cleaning in the toxic mercury atmosphere, left after ion engine testing in the tank. Lewis has since been renamed the John H. Glenn Research Center.

  12. Flying spot scanner

    An improved flying spot x-ray scanning equipment is described which includes a grid controlled x-ray tube and associated collimators for producing a pencil beam of x-rays. It is possible to control the position of the scan field relative to the patient, to control the width of the scan field and also to independently achieve an arbitary variation in the longitudinal dimension of the scan field. (U.K.)

  13. Highly-Durable Carbon Electrode for Electrochemical Capacitors

    Soshi Shiraishi


    [EN] The electric double layer capacitor (EDLC) is an electrochemical capacitor storing electric energy by charging the electric double layer on the micropores of a nanoporous carbon electrode such as activated carbon. The EDLC has a fast charge-discharge property and excellent cycle life, but its energy density is lower than other electrochemical energy storage devices such as the rechargeable battery. The energy density of the EDLC can be improved by increasing the double layer capacitance ...

  14. The possibility of giant dielectric materials for multilayer ceramic capacitors

    Ishii, Tatsuya; Endo, Makoto; Masuda, Kenichiro; Ishida, Keisuke


    There have been numerous reports on discovery of giant dielectric permittivity materials called internal barrier layer capacitor in the recent years. We took particular note of one of such materials, i.e., BaTiO3 with SiO2 coating. It shows expressions of giant electric permittivity when processed by spark plasma sintering. So we evaluated various electrical characteristics of this material to find out whether it is applicable to multilayer ceramic capacitors. Our evaluation revealed that the...

  15. CAPMIX - Deploying Capacitors for Salt Gradient Power Extraction

    Bijmans, M.F.M.; Burheim, O.S.; Bryjak, M.; Delgado, A; Hack, P.; Mantegazza, F.; Tenisson, S.; Hamelers, H.V.M.


    The process of mixing sea and river water can be utilised as a power source. At present, three groups of technology are established for doing so; i) mechanical; Pressure Retarded Osmosis PRO, ii) electrochemical reactions; Reverse ElectroDialysis (RED) and Nano Battery Electrodes (NBE) and iii) ultra capacitors; Capacitive Double Layer Expansion (CDLE) and Capacitors charge by the Donnan Potentials (CDP). The chemical potential for salt gradient power systems is only limited by th...

  16. Capacitor bonding techniques and reliability. [thermal cycling tests

    Kinser, D. L.; Graff, S. M.; Allen, R. V.; Caruso, S. V.


    The effect of thermal cycling on the mechanical failure of bonded ceramic chip capacitors mounted on alumina substrates is studied. It is shown that differential thermal expansion is responsible for the cumulative effects which lead to delayed failure of the capacitors. Harder or higher melting solders are found to be less susceptible to thermal cycling effects, although they are more likely to fail during initial processing operations.

  17. Enhancement of dielectric breakdown strengths in polymer film capacitors

    This paper reports that breakdown voltages of wound, polymer film/metal foil capacitors have been dramatically increased by briefly exposing them (after they had been spirally wound) to a low pressure, low temperature gas plasma. Exposure of wound, polycarbonate-based capacitors to a 96%CF4/4%O2 gas plasma for 4 minutes, for example, produced a 200% increase in breakdown voltage

  18. Partial Discharge in Capacitor Model at Low Temperature

    Rain, P.; M. Kachi; M. Remadnia; L. Herous; M. Nemamcha; Gosse, J.P.


    The partial discharge plays an important role in the ageing and the rupture process of solid or mixed insulation systems. Ithas been recognized that the failure of this insulation can be joined to the presence of partial discharge often in inclusionssparkling. Liquid filled cavities can be considered as the most likely defects that can exist in capacitors. In this paper wedescribe the partial discharge evolution at low temperatures in all-PP film capacitors according to the time and the appli...

  19. Anisotropic magneto-capacitance in ferromagnetic-plate capacitors

    Haigh, J. A.; Ciccarelli, C; Betz, A. C.; Irvine, A; Novák, V.; Jungwirth, T.; Wunderlich, J.


    The capacitance of a parallel plate capacitor can depend on applied magnetic field. Previous studies have identified capacitance changes induced via classical Lorentz force or spin-dependent Zeeman effects. Here we measure a magnetization direction dependent capacitance in parallel-plate capacitors where one plate is a ferromagnetic semiconductor, gallium manganese arsenide. This anisotropic magneto-capacitance is due to the anisotropy in the density of states dependent on the magnetization t...

  20. Ruthenium Oxide Electrochemical Super Capacitor Optimization for Pulse Power Applications

    Merryman, Stephen A.; Chen, Zheng


    Electrical actuator systems are being pursued as alternatives to hydraulic systems to reduce maintenance time, weight and costs while increasing reliability. Additionally, safety and environmental hazards associated with the hydraulic fluids can be eliminated. For most actuation systems, the actuation process is typically pulsed with high peak power requirements but with relatively modest average power levels. The power-time requirements for electrical actuators are characteristic of pulsed power technologies where the source can be sized for the average power levels while providing the capability to achieve the peak requirements. Among the options for the power source are battery systems, capacitor systems or battery-capacitor hybrid systems. Battery technologies are energy dense but deficient in power density; capacitor technologies are power dense but limited by energy density. The battery-capacitor hybrid system uses the battery to supply the average power and the capacitor to meet the peak demands. It has been demonstrated in previous work that the hybrid electrical power source can potentially provide a weight savings of approximately 59% over a battery-only source. Electrochemical capacitors have many properties that make them well-suited for electrical actuator applications. They have the highest demonstrated energy density for capacitive storage (up to 100 J/g), have power densities much greater than most battery technologies (greater than 30kW/kg), are capable of greater than one million charge-discharge cycles, can be charged at extremely high rates, and have non-explosive failure modes. Thus, electrochemical capacitors exhibit a combination of desirable battery and capacitor characteristics.

  1. Improvement of Routine Test Process of High Voltage Power Capacitors

    Vennerberg, Patrik


    The capacitor test process at ABB Capacitors in Ludvika must be improved to meet future demands for high voltage products. To find a solution to how to improve the test process, an investigation was performed to establish which parts of the process are used and how they operate. Several parts which can improves the process were identified. One of them was selected to be improved in correlation with the subject, mechanical engineering. Four concepts were generated and decision matrixes were us...

  2. Definite solution of the two (many) capacitors paradox

    Pankovic, Vladan


    In this work we suggest very simple solution of the two capacitors paradox in the completely ideal (without any electrical resistance or inductive) electrical circuit. Namely, it is shown that electrical field energy loss corresponds to works done by electrical fields of both capacitors by movement of the electrical charge. It is all and nothing more (some dissipative processes, e.g. Joule heating and electromagnetic wave emission effects) is necessary. Additionally, we shortly demonstrate th...

  3. Space Vehicle Power System Comprised of Battery/Capacitor Combinations

    Camarotte, C.; Lancaster, G. S.; Eichenberg, D.; Butler, S. M.; Miller, J. R.


    Recent improvements in energy densities of batteries open the possibility of using electric rather that hydraulic actuators in space vehicle systems. However, the systems usually require short-duration, high-power pulses. This power profile requires the battery system to be sized to meet the power requirements rather than stored energy requirements, often resulting in a large and inefficient energy storage system. Similar transient power applications have used a combination of two or more disparate energy storage technologies. For instance, placing a capacitor and a battery side-by-side combines the high energy density of a battery with the high power performance of a capacitor and thus can create a lighter and more compact system. A parametric study was performed to identify favorable scenarios for using capacitors. System designs were then carried out using equivalent circuit models developed for five commercial electrochemical capacitor products. Capacitors were sized to satisfy peak power levels and consequently "leveled" the power requirement of the battery, which can then be sized to meet system energy requirements. Simulation results clearly differentiate the performance offered by available capacitor products for the space vehicle applications.

  4. Capacitor discharge ignition system having a charging control means

    Fitzner, A.O.


    The invention provides charging control circuitry for a capacitor descharge ignition system having power capacitors connected to be discharged by main electronic switches such as SCR's into ignition transformers to sequentially fire the engine's spark plugs. The charging control circuits each include a charging SCR to limit charging current flow to the main capacitor, unless a discharge pulse into the ignition transformer has occurred in the recent past. Thus if a short circuit in either the main capacitor or main SCR in one of the ignition circuits prevents that ignition circuit form properly functioning, the charging SCR will limit the flow of charging current to the defective circuit and allow the other ignition circuit to receive charging current. The gate of the charging SCR is controlled by an amplified signal from a memory capacitor which is charged by the discharge pulse from the corresponding ignition circuit. The same memory capacitor also provides power to drive an indicator such as a light emitting diode.

  5. Physics Based Modeling and Prognostics of Electrolytic Capacitors

    Kulkarni, Chetan; Ceyla, Jose R.; Biswas, Gautam; Goebel, Kai


    This paper proposes first principles based modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors have become critical components in electronics systems in aeronautics and other domains. Degradations and faults in DC-DC converter unit propagates to the GPS and navigation subsystems and affects the overall solution. Capacitors and MOSFETs are the two major components, which cause degradations and failures in DC-DC converters. This type of capacitors are known for its low reliability and frequent breakdown on critical systems like power supplies of avionics equipment and electrical drivers of electromechanical actuators of control surfaces. Some of the more prevalent fault effects, such as a ripple voltage surge at the power supply output can cause glitches in the GPS position and velocity output, and this, in turn, if not corrected will propagate and distort the navigation solution. In this work, we study the effects of accelerated aging due to thermal stress on different sets of capacitors under different conditions. Our focus is on deriving first principles degradation models for thermal stress conditions. Data collected from simultaneous experiments are used to validate the desired models. Our overall goal is to derive accurate models of capacitor degradation, and use them to predict performance changes in DC-DC converters.

  6. Cryogenic Heat Engines Made Using Electrocaloric Capacitors

    Franz, Justin; Ordonez, Carlos A.


    It is possible to operate a heat engine using a cold substance, such as liquid nitrogen, as a heat sink and the atmosphere as a heat source.(C. A. Ordonez, American Journal of Physics 64), (1996) 479-481. With sufficient work produced per unit mass of liquid nitrogen, such a cryogenic heat engine may be suitable for powering short range, non-polluting automobiles.(C. A. Ordonez, Energy Conversion and Management 41) (2000) 331-341. Using existing liquid nitrogen plants to produce liquid nitrogen at about 50% of Carnot efficiency, and using renewable energy to power the liquid nitrogen plants, the cost to use liquid nitrogen to power an automobile per mile driven would be a few times the cost of using gasoline in the U.S. The increased ``fuel" cost may be acceptable for short range vehicles provided such vehicles have an acceptable price. We report on thermal-to-electrical energy conversion systems being studied for use as cryogenic heat engines. Specifically, capacitors made using paraelectric materials can provide energy conversion based on the electrocaloric effect. The electrocaloric effect is a change in electric field across a material that results from a change in temperature of the material.

  7. Capattery double layer capacitor life performance

    Evans, David A.; Clark, Nancy H.; Baca, W. E.; Miller, John R.; Barker, Thomas B.

    Double layer capacitors (DLCs) have received increased use in computer memory backup applications for consumer products during the past ten years. Their extraordinarily high capacitance density along with their maintenance-free operation makes them particularly suited for these products. These same features also make DLCs very attractive in military type applications. Unfortunately, lifetime performance data has not been reported in the literature for any DLC component. Our objective in this study was to investigate the effects that voltage and temperature have on the properties and performance of single and series-connected DLCs as a function of time. Evans model RE110474, 0.47-farad, 11.0-volt Capatteries were evaluated. These components have a tantalum package, use welded construction, and contain a glass-to-metal seal, all incorporated to circumvent the typical DLC failure modes of electrolyte loss and container corrosion. A five-level, two-factor Central Composite Design was used in the study. Single and series-connected Capatteries rated at 85 C, 11.0-volts operation were subjected to test temperatures between 25 and 95 C, and voltages between 0 and 12.9 volts (9 test conditions). Measured responses included capacitance, equivalent series resistance, and discharge time. Data were analyzed using a regression analysis to obtain response functions relating DLC properties to their voltage, temperature, and test time history. These results are described and should aid system and component engineers in using DLCs in critical applications.

  8. Elaboration of a microstructured inkjet-printed carbon electrochemical capacitor

    Pech, David; Brunet, Magali; Fabre, Norbert; Mesnilgrente, Fabien; Conedera, Veronique; Durou, Hugo [LAAS-CNRS, Universite de Toulouse, 7 av. du Colonel Roche, F-31077 Toulouse (France); Taberna, Pierre-Louis; Simon, Patrice [CIRIMAT-CNRS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse (France)


    Carbon-based micro-supercapacitors dedicated to energy storage in self-powered modules were fabricated with inkjet printing technology on silicon substrate. An ink was first prepared by mixing an activated carbon powder with a PTFE polymer binder in ethylene glycol stabilized with a surfactant then deposited by inkjet on patterned gold current collectors with the substrate heated at 140 C in order to assure a good homogeneity. Electrochemical micro-capacitors with electrodes in an interdigital configuration were fabricated, and characterized using electrochemical techniques in 1 M Et{sub 4}NBF{sub 4} propylene carbonate electrolyte. These micro-devices show an excellent capacitive behavior over a wide potential range of 2.5 V for a cell capacitance of 2.1 mF cm{sup -2}. The newly developed technology will allow the integration of the storage device as close as possible to the MEMS-based energy harvesting device, minimizing power losses through connections. (author)

  9. Pest Control on the "Fly"


    FlyCracker(R), a non-toxic and environmentally safe pesticide, can be used to treat and control fly problems in closed environments such as milking sheds, cattle barns and hutches, equine stables, swine pens, poultry plants, food-packing plants, and even restaurants, as well as in some outdoor animal husbandry environments. The product can be applied safely in the presence of animals and humans, and was recently permitted for use on organic farms as livestock production aids. FlyCracker's carbohydrate technology kills fly larvae within 24 hours. By killing larvae before they reach the adult stages, FlyCracker eradicates another potential breeding population. Because the process is physical-not chemical-flies and other insects never develop resistance to the treatment, giving way to unlimited use of product, while still keeping the same powerful effect.

  10. A Collision Resilient Flying Robot

    Briod, Adrien; Kornatowski, Przemyslaw Mariusz; Zufferey, Jean-Christophe; Floreano, Dario


    Flying robots that can locomote efficiently in GPS-denied cluttered environments have many applications, such as in search and rescue scenarios. However, dealing with the high amount of obstacles inherent to such environments is a major challenge for flying vehicles. Conventional flying platforms cannot afford to collide with obstacles, as the disturbance from the impact may provoke a crash to the ground, especially when friction forces generate torques affecting the attitude of the platform....