WorldWideScience

Sample records for short circuit behavior

  1. Short-circuit logic

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.

    2010-01-01

    Short-circuit evaluation denotes the semantics of propositional connectives in which the second argument is only evaluated if the first argument does not suffice to determine the value of the expression. In programming, short-circuit evaluation is widely used. A short-circuit logic is a variant of

  2. [Shunt and short circuit].

    Science.gov (United States)

    Rangel-Abundis, Alberto

    2006-01-01

    Shunt and short circuit are antonyms. In French, the term shunt has been adopted to denote the alternative pathway of blood flow. However, in French, as well as in Spanish, the word short circuit (court-circuit and cortocircuito) is synonymous with shunt, giving rise to a linguistic and scientific inconsistency. Scientific because shunt and short circuit made reference to a phenomenon that occurs in the field of the physics. Because shunt and short circuit are antonyms, it is necessary to clarify that shunt is an alternative pathway of flow from a net of high resistance to a net of low resistance, maintaining the stream. Short circuit is the interruption of the flow, because a high resistance impeaches the flood. This concept is applied to electrical and cardiovascular physiology, as well as to the metabolic pathways.

  3. Short- circuit tests of circuit breakers

    OpenAIRE

    Chorovský, P.

    2015-01-01

    This paper deals with short-circuit tests of low voltage electrical devices. In the first part of this paper, there are described basic types of short- circuit tests and their principles. Direct and indirect (synthetic) tests with more details are described in the second part. Each test and principles are explained separately. Oscilogram is obtained from short-circuit tests of circuit breakers at laboratory. The aim of this research work is to propose a test circuit for performing indirect test.

  4. Detecting short circuits during assembly

    Science.gov (United States)

    Deboo, G. J.

    1980-01-01

    Detector circuit identifies shorts between bus bars of electronic equipment being wired. Detector sounds alarm and indicates which planes are shorted. Power and ground bus bars are scanned continuously until short circuit occurs.

  5. Cell short circuit, preshort signature

    Science.gov (United States)

    Lurie, C.

    1980-01-01

    Short-circuit events observed in ground test simulations of DSCS-3 battery in-orbit operations are analyzed. Voltage signatures appearing in the data preceding the short-circuit event are evaluated. The ground test simulation is briefly described along with performance during reconditioning discharges. Results suggest that a characteristic signature develops prior to a shorting event.

  6. Short-circuit impedance measurement

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Nielsen, Arne Hejde; Poulsen, Niels Kjølstad

    2003-01-01

    Methods for estimating the short-circuit impedance in the power grid are investigated for various voltage levels and situations. The short-circuit impedance is measured, preferably from naturally occurring load changes in the grid, and it is shown that such a measurement system faces different...

  7. Short-Circuit Modeling of a Wind Power Plant: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, E.; Gevorgian, V.

    2011-03-01

    This paper investigates the short-circuit behavior of a WPP for different types of wind turbines. The short-circuit behavior will be presented. Both the simplified models and detailed models are used in the simulations and both symmetrical faults and unsymmetrical faults are discussed.

  8. A Simple Short Circuit Analysis for Power Networks

    Directory of Open Access Journals (Sweden)

    Koşalay İlhan

    2016-01-01

    Full Text Available This study investigates the transient behavior of short circuits in power circuits. The circuit consists of two part; input part and load part. These two parts are connected with a circuit breaker switch. The circuit works in two modes; first mode is when the switch is open and second mode is when the switch is closed. This study analyses the circuit when the switch is closed. The analysis is done with different types of closing angle. The analysis is done by forming state equations and those equations are solved numerically by using Matlab. The analysis and conclusion is performed by observing the behaviors of the graphs.

  9. Behavioral synthesis of asynchronous circuits

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard

    2005-01-01

    This thesis presents a method for behavioral synthesis of asynchronous circuits, which aims at providing a synthesis flow which uses and tranfers methods from synchronous circuits to asynchronous circuits. We move the synchronous behavioral synthesis abstraction into the asynchronous handshake...... is idle. This reduces unnecessary switching activity in the individual functional units and therefore the energy consumption of the entire circuit. A collection of behavioral synthesis algorithms have been developed allowing the designer to perform time and power constrained design space exploration...

  10. Shapeable short circuit resistant capacitor

    Science.gov (United States)

    Taylor, Ralph S.; Myers, John D.; Baney, William J.

    2015-10-06

    A ceramic short circuit resistant capacitor that is bendable and/or shapeable to provide a multiple layer capacitor that is extremely compact and amenable to desirable geometries. The capacitor that exhibits a benign failure mode in which a multitude of discrete failure events result in a gradual loss of capacitance. Each event is a localized event in which localized heating causes an adjacent portion of one or both of the electrodes to vaporize, physically cleaning away electrode material from the failure site. A first metal electrode, a second metal electrode, and a ceramic dielectric layer between the electrodes are thin enough to be formed in a serpentine-arrangement with gaps between the first electrode and the second electrode that allow venting of vaporized electrode material in the event of a benign failure.

  11. The Short Circuit Model of Reading.

    Science.gov (United States)

    Lueers, Nancy M.

    The name "short circuit" has been given to this model because, in many ways, it adequately describes what happens bioelectrically in the brain. The "short-circuiting" factors include linguistic, sociocultural, attitudinal and motivational, neurological, perceptual, and cognitive factors. Research is reviewed on ways in which each one affects any…

  12. Worst Asymmetrical Short-Circuit Current

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holmstrøm, O; Grastrup, L

    2010-01-01

    In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...

  13. Short circuit in deep brain stimulation.

    Science.gov (United States)

    Samura, Kazuhiro; Miyagi, Yasushi; Okamoto, Tsuyoshi; Hayami, Takehito; Kishimoto, Junji; Katano, Mitsuo; Kamikaseda, Kazufumi

    2012-11-01

    The authors undertook this study to investigate the incidence, cause, and clinical influence of short circuits in patients treated with deep brain stimulation (DBS). After the incidental identification of a short circuit during routine follow-up, the authors initiated a policy at their institution of routinely evaluating both therapeutic impedance and system impendence at every outpatient DBS follow-up visit, irrespective of the presence of symptoms suggesting possible system malfunction. This study represents a report of their findings after 1 year of this policy. Implanted DBS leads exhibiting short circuits were identified in 7 patients (8.9% of the patients seen for outpatient follow-up examinations during the 12-month study period). The mean duration from DBS lead implantation to the discovery of the short circuit was 64.7 months. The symptoms revealing short circuits included the wearing off of therapeutic effect, apraxia of eyelid opening, or dysarthria in 6 patients with Parkinson disease (PD), and dystonia deterioration in 1 patient with generalized dystonia. All DBS leads with short circuits had been anchored to the cranium using titanium miniplates. Altering electrode settings resulted in clinical improvement in the 2 PD cases in which patients had specific symptoms of short circuits (2.5%) but not in the other 4 cases. The patient with dystonia underwent repositioning and replacement of a lead because the previous lead was located too anteriorly, but did not experience symptom improvement. In contrast to the sudden loss of clinical efficacy of DBS caused by an open circuit, short circuits may arise due to a gradual decrease in impedance, causing the insidious development of neurological symptoms via limited or extended potential fields as well as shortened battery longevity. The incidence of short circuits in DBS may be higher than previously thought, especially in cases in which DBS leads are anchored with miniplates. The circuit impedance of DBS

  14. Textbook Error: Short Circuiting on Electrochemical Cell

    Science.gov (United States)

    Bonicamp, Judith M.; Clark, Roy W.

    2007-01-01

    Short circuiting an electrochemical cell is an unreported but persistent error in the electrochemistry textbooks. It is suggested that diagrams depicting a cell delivering usable current to a load be postponed, the theory of open-circuit galvanic cells is explained, the voltages from the tables of standard reduction potentials is calculated and…

  15. SITE WIDE SHORT CIRCUIT STUDY ASSESSMENT

    International Nuclear Information System (INIS)

    CARRATT, R.T.

    2004-01-01

    The Department of Energy requested that Fluor Hanford develop a plan to update the electrical distribution studies for FH managed facilities. Toward this end, an assessment of FH's nuclear facilities was performed to determine whether a current short circuit study of the facility electrical distribution system exists, and the status of such study. This report presents the methodology and results of that assessment. The assessment identified 29 relevant facilities. Of these, a short circuit study could not be identified for 15 facilities. A short circuit study was found to exist for fourteen facilities, however, of these 14, four were not released into a controlled document system, and two were not performed for the entire electrical distribution system. It is recommended that for four of the facilities no further action is required based upon the limited nature of the existing electrical system, or as in the case of PFP, the status of the existing short circuit study was determined adequate. For the majority of the facilities without a short circuit study, it is recommended that one is performed, and released into a controlled document system. Two facilities require further evaluation due to missing or conflicting documentation. For the remainder of the facilities, the recommendations are to review and revise as appropriate the existing study, and release into a controlled document system. A summation of the recommendations is presented

  16. Short-Circuit Degradation of 10-kV 10-A SiC MOSFET

    DEFF Research Database (Denmark)

    Eni, Emanuel-Petre; Beczkowski, Szymon; Munk-Nielsen, Stig

    2017-01-01

    The short-circuit behavior of power devices is highly relevant for converter design and fault protection. In this work, the degradation during short-circuit of a 10 kV 10 A 4H-SiC MOSFET is investigated at 6 kV DC-link voltage. The study aims to present the behavior of the device during short-circuit...... transients as it sustains increasing short-circuit pulses during its life-time. As the short-circuit pulse length increases, degradation of the device can be observed in periodically performed characterizations. The initial degradation seems to be associated with the channel region, and continuous stressing...

  17. Estimating the short-circuit impedance

    DEFF Research Database (Denmark)

    Nielsen, Arne Hejde; Pedersen, Knud Ole Helgesen; Poulsen, Niels Kjølstad

    1997-01-01

    A method for establishing a complex value of the short-circuit impedance from naturally occurring variations in voltage and current is discussed. It is the symmetrical three phase impedance at the fundamental grid frequency there is looked for. The positive sequence components in voltage...... and current are derived each period, and the short-circuit impedance is estimated from variations in these components created by load changes in the grid. Due to the noisy and dynamic grid with high harmonic distortion it is necessary to threat the calculated values statistical. This is done recursively...... through a RLS-algorithm. The algorithms have been tested and implemented on a PC at a 132 kV substation supplying a rolling mill. Knowing the short-circuit impedance gives the rolling mill an opportunity to adjust the arc furnace operation to keep flicker below a certain level. Therefore, the PC performs...

  18. Tester Detects Steady-Short Or Intermittent-Open Circuits

    Science.gov (United States)

    Anderson, Bobby L.

    1990-01-01

    Momentary open circuits or steady short circuits trigger buzzer. Simple, portable, lightweight testing circuit sounds long-duration alarm when it detects steady short circuit or momentary open circuit in coaxial cable or other two-conductor transmission line. Tester sensitive to discontinuities lasting 10 microseconds or longer. Used extensively for detecting intermittent open shorts in accelerometer and extensometer cables. Also used as ordinary buzzer-type continuity checker to detect steady short or open circuits.

  19. 30 CFR 75.601-1 - Short circuit protection; ratings and settings of circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; ratings and settings... Trailing Cables § 75.601-1 Short circuit protection; ratings and settings of circuit breakers. Circuit breakers providing short circuit protection for trailing cables shall be set so as not to exceed the...

  20. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Science.gov (United States)

    2010-07-01

    ... short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... circuits; overload and short-circuit protection. Automatic circuit-breaking devices or fuses of the correct type and capacity shall be installed so as to protect all electric equipment and circuits against short...

  1. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Science.gov (United States)

    2010-07-01

    ... short circuit protection. 75.518 Section 75.518 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection... installed so as to protect all electric equipment and circuits against short circuit and overloads. Three...

  2. 30 CFR 56.12065 - Short circuit and lightning protection.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit and lightning protection. 56... Electricity § 56.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning. ...

  3. 30 CFR 57.12065 - Short circuit and lightning protection.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit and lightning protection. 57... MINES Electricity Surface Only § 57.12065 Short circuit and lightning protection. Powerlines, including trolley wires, and telephone circuits shall be protected against short circuits and lightning. ...

  4. Short circuit protection for a power distribution system

    Science.gov (United States)

    Owen, J. R., III

    1969-01-01

    Sensing circuit detects when the output from a matrix is present and when it should be present. The circuit provides short circuit protection for a power distribution system where the selection of the driven load is accomplished by digital logic.

  5. Automatic location of short circuit faults

    Energy Technology Data Exchange (ETDEWEB)

    Lehtonen, M. [VTT Energy, Espoo (Finland); Hakola, T.; Antila, E. [ABB Power Oy, Helsinki (Finland); Seppaenen, M. [North-Carelian Power Company (Finland)

    1996-12-31

    In this presentation, the automatic location of short circuit faults on medium voltage distribution lines, based on the integration of computer systems of medium voltage distribution network automation is discussed. First the distribution data management systems and their interface with the substation telecontrol, or SCADA systems, is studied. Then the integration of substation telecontrol system and computerised relay protection is discussed. Finally, the implementation of the fault location system is presented and the practical experience with the system is discussed

  6. Automatic location of short circuit faults

    Energy Technology Data Exchange (ETDEWEB)

    Lehtonen, M [VTT Energy, Espoo (Finland); Hakola, T; Antila, E [ABB Power Oy (Finland); Seppaenen, M [North-Carelian Power Company (Finland)

    1998-08-01

    In this chapter, the automatic location of short circuit faults on medium voltage distribution lines, based on the integration of computer systems of medium voltage distribution network automation is discussed. First the distribution data management systems and their interface with the substation telecontrol, or SCADA systems, is studied. Then the integration of substation telecontrol system and computerized relay protection is discussed. Finally, the implementation of the fault location system is presented and the practical experience with the system is discussed

  7. Automatic location of short circuit faults

    Energy Technology Data Exchange (ETDEWEB)

    Lehtonen, M [VTT Energy, Espoo (Finland); Hakola, T; Antila, E [ABB Power Oy, Helsinki (Finland); Seppaenen, M [North-Carelian Power Company (Finland)

    1997-12-31

    In this presentation, the automatic location of short circuit faults on medium voltage distribution lines, based on the integration of computer systems of medium voltage distribution network automation is discussed. First the distribution data management systems and their interface with the substation telecontrol, or SCADA systems, is studied. Then the integration of substation telecontrol system and computerised relay protection is discussed. Finally, the implementation of the fault location system is presented and the practical experience with the system is discussed

  8. Thyristor based short circuit current injection in isolated grids

    OpenAIRE

    Hoff, Bjarte; Sharma, Pawan; Østrem, Trond

    2017-01-01

    This paper proposes a thyristor based short circuit current injector for providing short circuit current in isolated and weak grids, where sufficient fault current to trigger circuit breakers may not be available. This will allow the use of conventional miniature circuit breakers, which requires high fault current for instantaneous tripping. The method has been validated through experiments.

  9. Synchronous Condenser Allocation for Improving System Short Circuit Ratio

    DEFF Research Database (Denmark)

    Jia, Jundi; Yang, Guangya; Nielsen, Arne Hejde

    2018-01-01

    With converter-based renewable energy sources increasingly integrated into power systems and conventional power plants gradually phased out, future power systems will experience reduced short circuit strength. The deployment of synchronous condensers can serve as a potential solution. This paper...... presents an optimal synchronous condenser allocation method for improving system short circuit ratio at converter point of common coupling using a modified short circuit analysis approach. The total cost of installing new synchronous condensers is minimized while the system short circuit ratios...

  10. LS1 Report: short-circuit tests

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    As the LS1 draws to an end, teams move from installation projects to a phase of intense testing. Among these are the so-called 'short-circuit tests'. Currently under way at Point 7, these tests verify the cables, the interlocks, the energy extraction systems, the power converters that provide current to the superconducting magnets and the cooling system.   Thermal camera images taken during tests at point 4 (IP4). Before putting beam into the LHC, all of the machine's hardware components need to be put to the test. Out of these, the most complicated are the superconducting circuits, which have a myriad of different failure modes with interlock and control systems. While these will be tested at cold - during powering tests to be done in August - work can still be done beforehand. "While the circuits in the magnets themselves cannot be tested at warm, what we can do is verify the power converter and the circuits right up to the place the cables go into the magn...

  11. Effect of Short-Circuit Faults in the Back-to-Back Power Electronic Converter and Rotor Terminals on the Operational Behavior of the Doubly-Fed Induction Generator Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Dimitrios G. Giaourakis

    2015-02-01

    Full Text Available This paper deals with the operational behavior of the Doubly-Fed Induction Generator Wind Energy Conversion System under power electronic converter and rotor terminals faulty conditions. More specifically, the effect of the short-circuit fault both in one IGBT of the back-to-back power electronic converter and in rotor phases on the overall system behavior has been investigated via simulation using a system of 2 MW. Finally, the consequences of these faults have been evaluated.

  12. High voltage short plus generation based on avalanche circuit

    International Nuclear Information System (INIS)

    Hu Yuanfeng; Yu Xiaoqi

    2006-01-01

    Simulate the avalanche circuit in series with PSPICE module, design the high voltage short plus generation circuit by avalanche transistor in series for the sweep deflection circuit of streak camera. The output voltage ranges 1.2 KV into 50 ohm load. The rise time of the circuit is less than 3 ns. (authors)

  13. Robustness of MW-Level IGBT modules against gate oscillations under short circuit events

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Wu, Rui; Iannuzzo, Francesco

    2015-01-01

    The susceptibility of MW-level IGBT power modules to critical gate voltage oscillations during short circuit events has been evidenced experimentally. This paper proposes a sensitivity analysis method to better understand the oscillating behavior dependence on different operating conditions (i...... the oscillation phenomenon, as well as to further improve the device performance during short circuit....

  14. Full Digital Short Circuit Protection for Advanced IGBTs

    OpenAIRE

    谷村, 拓哉; 湯浅, 一史; 大村, 一郎

    2011-01-01

    A full digital short circuit protection method for advanced IGBTs has been proposed and experimentally demonstrated for the first time. The method employs combination of digital circuit, the gate charge sense instead of the conventional sense IGBT and analog circuit configuration. Digital protection scheme has significant advantages in thevprotection speed and flexibility.

  15. TCAD analysis of short-circuit oscillations in IGBTs

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Iannuzzo, Francesco; Rahimo, Munaf

    2017-01-01

    Insulated-Gate Bipolar Transistors (IGBTs) exhibit a gate-voltage oscillation phenomenon during short-circuit, which can result in a gate-oxide breakdown. The oscillations have been investigated through device simulations and experimental investigations of a 3.3-kV IGBT. It has been found...... during short circuit....

  16. Electrical short circuit and current overload tests on aircraft wiring

    Science.gov (United States)

    Cahill, Patricia

    1995-01-01

    The findings of electrical short circuit and current overload tests performed on commercial aircraft wiring are presented. A series of bench-scale tests were conducted to evaluate circuit breaker response to overcurrent and to determine if the wire showed any visible signs of thermal degradation due to overcurrent. Three types of wire used in commercial aircraft were evaluated: MIL-W-22759/34 (150 C rated), MIL-W-81381/12 (200 C rated), and BMS 1360 (260 C rated). A second series of tests evaluated circuit breaker response to short circuits and ticking faults. These tests were also meant to determine if the three test wires behaved differently under these conditions and if a short circuit or ticking fault could start a fire. It is concluded that circuit breakers provided reliable overcurrent protection. Circuit breakers may not protect wire from ticking faults but can protect wire from direct shorts. These tests indicated that the appearance of a wire subjected to a current that totally degrades the insulation looks identical to a wire subjected to a fire; however the 'fire exposed' conductor was more brittle than the conductor degraded by overcurrent. Preliminary testing indicates that direct short circuits are not likely to start a fire. Preliminary testing indicated that direct short circuits do not erode insulation and conductor to the extent that ticking faults did. Circuit breakers may not safeguard against the ignition of flammable materials by ticking faults. The flammability of materials near ticking faults is far more important than the rating of the wire insulation material.

  17. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Science.gov (United States)

    2010-07-01

    ... short circuit protection; minimum requirements. 77.506-1 Section 77.506-1 Mineral Resources MINE SAFETY...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements. Devices providing either short circuit protection or protection against overload shall conform to the...

  18. 30 CFR 75.518-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 75.518-1 Section 75.518-1 Mineral Resources MINE SAFETY... short circuit protection; minimum requirements. A device to provide either short circuit protection or...

  19. Improved Short-Circuit Protection for Power Cells in Series

    Science.gov (United States)

    Davies, Francis

    2008-01-01

    A scheme for protection against short circuits has been devised for series strings of lithium electrochemical cells that contain built-in short-circuit protection devices, which go into a high-resistance, current-limiting state when heated by excessive current. If cells are simply connected in a long series string to obtain a high voltage and a short circuit occurs, whichever short-circuit protection device trips first is exposed to nearly the full string voltage, which, typically, is large enough to damage the device. Depending on the specific cell design, the damage can defeat the protective function, cause a dangerous internal short circuit in the affected cell, and/or cascade to other cells. In the present scheme, reverse diodes rated at a suitably high current are connected across short series sub-strings, the lengths of which are chosen so that when a short-circuit protection device is tripped, the voltage across it does not exceed its rated voltage. This scheme preserves the resetting properties of the protective devices. It provides for bypassing of cells that fail open and limits cell reversal, though not as well as does the more-expensive scheme of connecting a diode across every cell.

  20. Capacitive short circuit detection in transformer core laminations

    International Nuclear Information System (INIS)

    Schulz, Carl A.; Duchesne, Stephane; Roger, Daniel; Vincent, Jean-Noel

    2008-01-01

    A capacitive measurement procedure is proposed that serves to detect burr-induced short circuits in transformer core laminations. The tests are conducted on stacks of transformer steel sheets as used for transformer core production and yield a short-circuit probability indicative of the additional eddy current losses to be expected. Applied during the assembly of transformer cores, the measurements can help to decide whether the burr treatment process is working efficiently or has to be readjusted

  1. Simulation and experimental study on lithium ion battery short circuit

    International Nuclear Information System (INIS)

    Zhao, Rui; Liu, Jie; Gu, Junjie

    2016-01-01

    Highlights: • Both external and internal short circuit tests were performed on Li-ion batteries. • An electrochemical–thermal model with an additional nail site heat source is presented. • The model can accurately simulate the temperature variations of non-venting batteries. • The model is reliable in predicting the occurrence and start time of thermal runaway. • A hydrogel cooling system proves its strength in preventing battery thermal runaway. - Abstract: Safety is the first priority in lithium ion (Li-ion) battery applications. A large portion of electrical and thermal hazards caused by Li-ion battery is associated with short circuit. In this paper, both external and internal short circuit tests are conducted. Li-ion batteries and battery packs of different capacities are used. The results indicate that external short circuit is worse for smaller size batteries due to their higher internal resistances, and this type of short can be well managed by assembling fuses. In internal short circuit tests, higher chance of failure is found on larger capacity batteries. A modified electrochemical–thermal model is proposed, which incorporates an additional heat source from nail site and proves to be successful in depicting temperature changes in batteries. Specifically, the model is able to estimate the occurrence and approximate start time of thermal runaway. Furthermore, the effectiveness of a hydrogel based thermal management system in suppressing thermal abuse and preventing thermal runaway propagation is verified through the external and internal short tests on batteries and battery packs.

  2. Short-circuited coil in a solenoid circuit of a pulse magnetic field

    International Nuclear Information System (INIS)

    Kivshik, A.F.; Dubrovin, V.Yu.

    1976-01-01

    A short-circuited coil at the end of a long pulse solenoid attenuates the dissipation field by 3-5 times. A plug-configuration field is set up in the middle portion of the pulse solenoid incorporating the short-circuited coils. Shunting of the coils with the induction current by resistor Rsub(shunt) provides for the adjustment of the plug ratio γ

  3. The short circuit instability in protoplanetary disks

    DEFF Research Database (Denmark)

    Hubbard, A.; McNally, C.P.; Mac Low, M.M.

    2013-01-01

    We introduce a magneto-hydrodynamic instability which occurs, among other locations, in the inner, hot regions of protoplanetary disks, and which alters the way in which resistive dissipation of magnetic energy into heat proceeds. This instability can be likened to both an electrical short circui...

  4. [Electric short-circuit incident observed with "Upsher" laryngoscopes].

    Science.gov (United States)

    Tritsch, L; Vailly, B

    2006-01-01

    We observed an electrical short-circuit between a fasten screw of the printed circuit and the handle of an Upsher universal laryngoscope (serial number UQ1). The isolating Silicone layer was broken above the screw. This isolation defect was found all over our Upsher laryngoscopes of the UQ1 series. No doubt that if accumulators were used instead of batteries, emitted heat would be in largest amount and perhaps dangerous.

  5. Capacitive effects in IGBTs limiting their reliability under short circuit

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Iannuzzo, Francesco; Rahimo, Munaf

    2017-01-01

    The short-circuit oscillation mechanism in IGBTs is investigated in this paper by the aid of semiconductor device simulation tools. A 3.3-kV IGBT cell has been used for the simulations demonstrating that a single IGBT cell is able to oscillate together with the external circuit parasitic elements....... The work presented here through both circuit and device analysis, confirms that the oscillations can be understood with focus on the device capacitive effects coming from the interaction between carrier concentration and the electric field. The paper also shows the 2-D effects during one oscillation cycle...

  6. Integrating Neural Circuits Controlling Female Sexual Behavior.

    Science.gov (United States)

    Micevych, Paul E; Meisel, Robert L

    2017-01-01

    The hypothalamus is most often associated with innate behaviors such as is hunger, thirst and sex. While the expression of these behaviors important for survival of the individual or the species is nested within the hypothalamus, the desire (i.e., motivation) for them is centered within the mesolimbic reward circuitry. In this review, we will use female sexual behavior as a model to examine the interaction of these circuits. We will examine the evidence for a hypothalamic circuit that regulates consummatory aspects of reproductive behavior, i.e., lordosis behavior, a measure of sexual receptivity that involves estradiol membrane-initiated signaling in the arcuate nucleus (ARH), activating β-endorphin projections to the medial preoptic nucleus (MPN), which in turn modulate ventromedial hypothalamic nucleus (VMH) activity-the common output from the hypothalamus. Estradiol modulates not only a series of neuropeptides, transmitters and receptors but induces dendritic spines that are for estrogenic induction of lordosis behavior. Simultaneously, in the nucleus accumbens of the mesolimbic system, the mating experience produces long term changes in dopamine signaling and structure. Sexual experience sensitizes the response of nucleus accumbens neurons to dopamine signaling through the induction of a long lasting early immediate gene. While estrogen alone increases spines in the ARH, sexual experience increases dendritic spine density in the nucleus accumbens. These two circuits appear to converge onto the medial preoptic area where there is a reciprocal influence of motivational circuits on consummatory behavior and vice versa . While it has not been formally demonstrated in the human, such circuitry is generally highly conserved and thus, understanding the anatomy, neurochemistry and physiology can provide useful insight into the motivation for sexual behavior and other innate behaviors in humans.

  7. Integrating Neural Circuits Controlling Female Sexual Behavior

    Directory of Open Access Journals (Sweden)

    Paul E. Micevych

    2017-06-01

    Full Text Available The hypothalamus is most often associated with innate behaviors such as is hunger, thirst and sex. While the expression of these behaviors important for survival of the individual or the species is nested within the hypothalamus, the desire (i.e., motivation for them is centered within the mesolimbic reward circuitry. In this review, we will use female sexual behavior as a model to examine the interaction of these circuits. We will examine the evidence for a hypothalamic circuit that regulates consummatory aspects of reproductive behavior, i.e., lordosis behavior, a measure of sexual receptivity that involves estradiol membrane-initiated signaling in the arcuate nucleus (ARH, activating β-endorphin projections to the medial preoptic nucleus (MPN, which in turn modulate ventromedial hypothalamic nucleus (VMH activity—the common output from the hypothalamus. Estradiol modulates not only a series of neuropeptides, transmitters and receptors but induces dendritic spines that are for estrogenic induction of lordosis behavior. Simultaneously, in the nucleus accumbens of the mesolimbic system, the mating experience produces long term changes in dopamine signaling and structure. Sexual experience sensitizes the response of nucleus accumbens neurons to dopamine signaling through the induction of a long lasting early immediate gene. While estrogen alone increases spines in the ARH, sexual experience increases dendritic spine density in the nucleus accumbens. These two circuits appear to converge onto the medial preoptic area where there is a reciprocal influence of motivational circuits on consummatory behavior and vice versa. While it has not been formally demonstrated in the human, such circuitry is generally highly conserved and thus, understanding the anatomy, neurochemistry and physiology can provide useful insight into the motivation for sexual behavior and other innate behaviors in humans.

  8. Neural Circuit Mechanisms of Social Behavior.

    Science.gov (United States)

    Chen, Patrick; Hong, Weizhe

    2018-04-04

    We live in a world that is largely socially constructed, and we are constantly involved in and fundamentally influenced by a broad array of complex social interactions. Social behaviors among conspecifics, either conflictive or cooperative, are exhibited by all sexually reproducing animal species and are essential for the health, survival, and reproduction of animals. Conversely, impairment in social function is a prominent feature of several neuropsychiatric disorders, such as autism spectrum disorders and schizophrenia. Despite the importance of social behaviors, many fundamental questions remain unanswered. How is social sensory information processed and integrated in the nervous system? How are different social behavioral decisions selected and modulated in brain circuits? Here we discuss conceptual issues and recent advances in our understanding of brain regions and neural circuit mechanisms underlying the regulation of social behaviors. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Error Mitigation for Short-Depth Quantum Circuits

    Science.gov (United States)

    Temme, Kristan; Bravyi, Sergey; Gambetta, Jay M.

    2017-11-01

    Two schemes are presented that mitigate the effect of errors and decoherence in short-depth quantum circuits. The size of the circuits for which these techniques can be applied is limited by the rate at which the errors in the computation are introduced. Near-term applications of early quantum devices, such as quantum simulations, rely on accurate estimates of expectation values to become relevant. Decoherence and gate errors lead to wrong estimates of the expectation values of observables used to evaluate the noisy circuit. The two schemes we discuss are deliberately simple and do not require additional qubit resources, so to be as practically relevant in current experiments as possible. The first method, extrapolation to the zero noise limit, subsequently cancels powers of the noise perturbations by an application of Richardson's deferred approach to the limit. The second method cancels errors by resampling randomized circuits according to a quasiprobability distribution.

  10. Short Circuit Tests First Step of LHC Hardware Commissioning Completion

    CERN Document Server

    Barbero-Soto, E; Bordry, Frederick; Casas Lino, M P; Coelingh, G J; Cumer, G; Dahlerup-Petersen, K; Guillaume, J C; Inigo-Golfin, J; Montabonnet, V; Nisbet, D; Pojer, M; Principe, R; Rodríguez-Mateos, F; Saban, R; Schmidt, R; Thiesen, H; Vergara-Fernández, A; Zerlauth, M; Castaneda Serra, A; Romera Ramirez, I

    2008-01-01

    For the two counter rotating beams in the Large Hadron Collider (LHC) about 8000 magnets (main dipole and quadrupole magnets, corrector magnets, separation dipoles, matching section quadrupoles etc.) are powered in about 1500 superconducting electrical circuits. The magnets are powered by power converters that have been designed for the LHC with a current between 60 and 13000A. Between October 2005 and September 2007 the so-called Short Circuit Tests were carried-out in 15 underground zones where the power converters of the superconducting circuits are placed. The tests aimed to qualify the normal conducting equipments of the circuits such as power converters and normal conducting high current cables. The correct operation of interlock and energy extraction systems was validated. The infrastructure systems including AC distribution, water and air cooling and the control systems was also commissioned. In this paper the results of the two year test campaign are summarized with particular attention to problems e...

  11. Prevention of short circuits in solution-processed OLED devices

    NARCIS (Netherlands)

    Jolt Oostra, A.; Blom, P.W.M.; Michels, J.J.

    2014-01-01

    Pinholes in the emitting layer of an organic light emitting diode (OLED), e.g. induced by particle contamination or processing flaws, lead to direct contact between the hole-injection layer (HIL) and the cathode. The resulting short circuits give rise to catastrophic device failure. We demonstrate

  12. Packaging Solutions for Mitigating IGBT Short-Circuit Instabilities

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Iannuzzo, Francesco; Blaabjerg, Frede

    2017-01-01

    In this paper, the gate voltage oscillations occurring under short-circuit conditions in Insulated-Gate Bipolar Transistors are investigated, together with their dependency with respect to stray inductance variations. By using AnSYS Q3D Extractor, electromagnetic simulations are conducted to extr...

  13. A Computer Program for Short Circuit Analysis of Electric Power ...

    African Journals Online (AJOL)

    The Short Circuit Analysis Program (SCAP) is to be used to assess the composite effects of unbalanced and balanced faults on the overall reliability of electric power system. The program uses the symmetrical components method to compute all phase and sequence quantities for any bus or branch of a given power network ...

  14. 30 CFR 77.600 - Trailing cables; short-circuit protection; disconnecting devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Trailing cables; short-circuit protection... AREAS OF UNDERGROUND COAL MINES Trailing Cables § 77.600 Trailing cables; short-circuit protection; disconnecting devices. Short-circuit protection for trailing cables shall be provided by an automatic circuit...

  15. 30 CFR 75.518-2 - Incandescent lamps, overload and short circuit protection.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Incandescent lamps, overload and short circuit...-General § 75.518-2 Incandescent lamps, overload and short circuit protection. Incandescent lamps installed... or direct current feeder circuits, need not be provided with separate short circuit or overload...

  16. Chaotic behavior learning of Chua's circuit

    International Nuclear Information System (INIS)

    Sun Jian-Cheng

    2012-01-01

    Least-square support vector machines (LS-SVM) are applied for learning the chaotic behavior of Chua's circuit. The system is divided into three multiple-input single-output (MISO) structures and the LS-SVM are trained individually. Comparing with classical approaches, the proposed one reduces the structural complexity and the selection of parameters is avoided. Some parameters of the attractor are used to compare the chaotic behavior of the reconstructed and the original systems for model validation. Results show that the LS-SVM combined with the MISO can be trained to identify the underlying link among Chua's circuit state variables, and exhibit the chaotic attractors under the autonomous working mode

  17. On-Demand Cell Internal Short Circuit Device

    Science.gov (United States)

    Darcy, Eric; Keyser, Matthew

    2014-01-01

    A device implantable in Li-ion cells that can generate a hard internal short circuit on-demand by exposing the cell to 60?C has been demonstrated to be valuable for expanding our understanding of cell responses. The device provides a negligible impact to cell performance and enables the instigation of the 4 general categories of cell internal shorts to determine relative severity and cell design susceptibility. Tests with a 18650 cell design indicates that the anode active material short to the aluminum cathode current collector tends to be more catastrophic than the 3 other types of internal shorts. Advanced safety features (such as shutdown separators) to prevent or mitigate the severity of cell internal shorts can be verified with this device. The hard short success rate achieved to date in 18650 cells is about 80%, which is sufficient for using these cells in battery assemblies for field-failure-relevant, cell-cell thermal runaway propagation verification tests

  18. Improving the Short-Circuit Reliability in IGBTs

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Iannuzzo, Francesco; Rahimo, Munaf

    2018-01-01

    takes place during the IGBT short-circuit, whose time-varying element is the Miller capacitance, which is involved in the amplification mechanism. This hypothesis has been validated through simulations and its mitigation is possible by increasing the electric field at the emitter of the IGBT......In this paper, the oscillation mechanism limiting the ruggedness of IGBTs is investigated through both circuit and device analysis. The work presented here is based on a time-domain approach for two different IGBT cell structures (i.e., trench-gate and planar), illustrating the 2-D effects during...

  19. Cable Hot Shorts and Circuit Analysis in Fire Risk Assessment

    International Nuclear Information System (INIS)

    LaChance, Jeffrey; Nowlen, Steven P.; Wyant, Frank

    1999-01-01

    Under existing methods of probabilistic risk assessment (PRA), the analysis of fire-induced circuit faults has typically been conducted on a simplistic basis. In particular, those hot-short methodologies that have been applied remain controversial in regards to the scope of the assessments, the underlying methods, and the assumptions employed. To address weaknesses in fire PRA methodologies, the USNRC has initiated a fire risk analysis research program that includes a task for improving the tools for performing circuit analysis. The objective of this task is to obtain a better understanding of the mechanisms linking fire-induced cable damage to potentially risk-significant failure modes of power, control, and instrumentation cables. This paper discusses the current status of the circuit analysis task

  20. Tin Whisker Electrical Short Circuit Characteristics. Part 2

    Science.gov (United States)

    Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Lawrence L.; Wright, Maria C.

    2009-01-01

    Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.

  1. The short-circuit concept used in field equivalence principles

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1990-01-01

    In field equivalence principles, electric and magnetic surface currents are specified and considered as impressed currents. Often the currents are placed on perfect conductors. It is shown that these currents can be treated through two approaches. The first approach is decomposition of the total...... field into partial fields caused by the individual impressed currents. When this approach is used, it is shown that, on a perfect electric (magnetic) conductor, impressed electric (magnetic) surface currents are short-circuited. The second approach is to note that, since Maxwell's equations...... and the boundary conditions are satisfied, none of the impressed currents is short-circuited and no currents are induced on the perfect conductors. Since all currents and field quantities are considered at the same time, this approach is referred to as the total-field approach. The partial-field approach leads...

  2. A neuromorphic circuit mimicking biological short-term memory.

    Science.gov (United States)

    Barzegarjalali, Saeid; Parker, Alice C

    2016-08-01

    Research shows that the way we remember things for a few seconds is a different mechanism from the way we remember things for a longer time. Short-term memory is based on persistently firing neurons, whereas storing information for a longer time is based on strengthening the synapses or even forming new neural connections. Information about location and appearance of an object is segregated and processed by separate neurons. Furthermore neurons can continue firing using different mechanisms. Here, we have designed a biomimetic neuromorphic circuit that mimics short-term memory by firing neurons, using biological mechanisms to remember location and shape of an object. Our neuromorphic circuit has a hybrid architecture. Neurons are designed with CMOS 45nm technology and synapses are designed with carbon nanotubes (CNT).

  3. Investigation on the Short-Circuit Behavior of an Aged IGBT Module Through a 6 kA/1.1 kV Non-Destructive Testing Equipment

    DEFF Research Database (Denmark)

    Wu, Rui; Smirnova, Liudmila; Iannuzzo, Francesco

    2014-01-01

    This paper describes the design and development of a 6 kA/1.1 kV non-destructive testing system, which aims for short circuit testing of high-power IGBT modules. An ultralow stray inductance of 37 nH is achieved in the implementation of the tester. An 100 MHz FPGA supervising unit enables 10 ns...

  4. Composite behaviors of dual meminductor circuits

    International Nuclear Information System (INIS)

    Zheng Ci-Yan; Yu Dong-Sheng; Liang Yan; Chen Meng-Ke

    2015-01-01

    This paper focuses on analyzing the composite dynamic behaviors of two meminductors in serial and parallel connections with different polarities. Based on the constitutive relations, two time-integral-of-flux (TIF) controlled meminductors are adopted to theoretically demonstrate the variation of memductance in terms of TIF, charge, flux, and current. By utilizing a floating memristor-less meminductor emulator, the theoretical analysis reported in this paper is confirmed via a PSPICE simulation study and hardware experiment. Good agreement among theoretical analysis, simulation, and hardware validation confirms that dual meminductor circuits in composite connections behave as a new meminductor with higher complexity. (paper)

  5. Experimental study on short-circuit characteristics of the new protection circuit of insulated gate bipolar transistor

    International Nuclear Information System (INIS)

    Ji, In-Hwan; Choi, Young-Hwan; Ha, Min-Woo; Han, Min-Koo; Choi, Yearn-Ik

    2006-01-01

    A new protection circuit employing the collector to emitter voltage (V CE ) sensing scheme for short-circuit withstanding capability of the insulated gate bipolar transistor (IGBT) is proposed and verified by experimental results. Because the current path between the gate and collector can be successfully eliminated in the proposed protection circuit, the power consumption can be reduced and the gate input impedance can be increased. Previous study is limited to dc characteristics. However, experimental results show that the proposed protection circuit successfully reduces the over-current of main IGBT by 80.4% under the short-circuit condition

  6. Short-circuit experiments on a high Tc-superconducting cable conductor

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Jensen, E.H.; Traholt, C.

    2002-01-01

    A high temperature superconductor (HTS) cable conductor (CC) with a critical current of 2.1 kA was tested over a range of short-circuit currents up to 20 kA. The duration of the short-circuit currents is 1 s. Between each short-circuit test the critical current of the HTS CC was measured in order...

  7. 30 CFR 75.601 - Short circuit protection of trailing cables.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection of trailing cables. 75... MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Trailing Cables § 75.601 Short circuit protection of trailing cables. [Statutory Provisions] Short circuit protection for trailing cables...

  8. 30 CFR 75.601-2 - Short circuit protection; use of fuses; approval by the Secretary.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; use of fuses... Trailing Cables § 75.601-2 Short circuit protection; use of fuses; approval by the Secretary. Fuses shall not be employed to provide short circuit protection for trailing cables unless specifically approved...

  9. Closed Form Solution of Synchronous Machine Short Circuit Transients

    Directory of Open Access Journals (Sweden)

    Gibson H.M. Sianipar

    2010-05-01

    Full Text Available This paper presents the closed form solution of the synchronous machine transients undergoing short circuit. That analytic formulation has been derived based on linearity and balanced conditions of the fault. Even though restrictive, the proposed method will serve somehow or other as a new resource for EMTP productivity. Indisputably superior, the closed-form formulation has some features inimitable by discretization such as continuity, accuracy and absolute numerical stability. Moreover, it enables us to calculate states at one specific instant independent of previous states or a snapshot, which any discretization methods cannot do.

  10. Investigation on the Short Circuit Safe Operation Area of SiC MOSFET Power Modules

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Luo, Haoze; Iannuzzo, Francesco

    2016-01-01

    This paper gives a better insight of the short circuit capability of state-of-the-art SiC MOSFET power modules rated at 1.2 kV by highlighting the physical limits under different operating conditions. Two different failure mechanisms have been identified, both reducing the short-circuit capability...... of SiC power modules in respect to discrete SiC devices. Based on such failure mechanisms, two short circuit criteria (i.e., short circuit current-based criterion and gate voltage-based criterion) are proposed in order to ensure their robustness under short-circuit conditions. A Safe Operation Area (SOA...

  11. A Short-Circuit Safe Operation Area Identification Criterion for SiC MOSFET Power Modules

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Iannuzzo, Francesco; Luo, Haoze

    2017-01-01

    This paper proposes a new method for the investigation of the short-circuit safe operation area (SCSOA) of state-of-the-art SiC MOSFET power modules rated at 1.2 kV based on the variations in SiC MOSFET electrical parameters (e.g., short-circuit current and gate–source voltage). According...... to the experimental results, two different failure mechanisms have been identified, both reducing the short-circuit capability of SiC power modules with respect to discrete SiC devices. Based on such failure mechanisms, two short-circuit safety criteria have been formulated: 1) the short-circuit...

  12. Olfactory circuits and behaviors of nematodes.

    Science.gov (United States)

    Rengarajan, Sophie; Hallem, Elissa A

    2016-12-01

    Over one billion people worldwide are infected with parasitic nematodes. Many parasitic nematodes actively search for hosts to infect using volatile chemical cues, so understanding the olfactory signals that drive host seeking may elucidate new pathways for preventing infections. The free-living nematode Caenorhabditis elegans is a powerful model for parasitic nematodes: because sensory neuroanatomy is conserved across nematode species, an understanding of the microcircuits that mediate olfaction in C. elegans may inform studies of olfaction in parasitic nematodes. Here we review circuit mechanisms that allow C. elegans to respond to odorants, gases, and pheromones. We also highlight work on the olfactory behaviors of parasitic nematodes that lays the groundwork for future studies of their olfactory microcircuits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Analysis of High Power IGBT Short Circuit Failures

    Energy Technology Data Exchange (ETDEWEB)

    Pappas, G.

    2005-02-11

    The Next Linear Collider (NLC) accelerator proposal at SLAC requires a highly efficient and reliable, low cost, pulsed-power modulator to drive the klystrons. A solid-state induction modulator has been developed at SLAC to power the klystrons; this modulator uses commercial high voltage and high current Insulated Gate Bipolar Transistor (IGBT) modules. Testing of these IGBT modules under pulsed conditions was very successful; however, the IGBTs failed when tests were performed into a low inductance short circuit. The internal electrical connections of a commercial IGBT module have been analyzed to extract self and mutual partial inductances for the main current paths as well as for the gate structure. The IGBT module, together with the partial inductances, has been modeled using PSpice. Predictions for electrical paths that carry the highest current correlate with the sites of failed die under short circuit tests. A similar analysis has been carried out for a SLAC proposal for an IGBT module layout. This paper discusses the mathematical model of the IGBT module geometry and presents simulation results.

  14. Control of internal and external short circuits in lithium batteries using a composite thermal switch

    Science.gov (United States)

    Mcdonald, Robert C.; Pickett, Jerome; Goebel, Franz

    1991-01-01

    A composite material has been developed, consisting of a blend of metal and fluorocarbon particles, which behaves as an electronic conductor at room temperature and which abruptly becomes an insulator at a predetermined temperature. This switching behavior results from the difference in thermal expansion coefficients between the conductive and non-conductive portions of the composite. This material was applied as a thin film between the carbon cathode in Li/SOCl2 cells, and the metallic cathode current collector. Using test articles incorporating this feature it was shown that lithium cells externally heated or internally heated during a short circuit lost rate capability and the ability to overheat well below the melting point of lithium (180 C). Thus, during an internal or external cell short circuit, the potential for thermal runaway involving reactions of molten lithium is avoided.

  15. Compact electro-thermal modeling of a SiC MOSFET power module under short-circuit conditions

    DEFF Research Database (Denmark)

    Ceccarelli, Lorenzo; Reigosa, Paula Diaz; Bahman, Amir Sajjad

    2017-01-01

    A novel physics-based, electro-thermal model which is capable of estimating accurately the short-circuit behavior and thermal instabilities of silicon carbide MOSFET multi-chip power modules is proposed in this paper. The model has been implemented in PSpice and describes the internal structure.......2 kV breakdown voltage and about 300 A rated current. The short-circuit behavior of the module is investigated experimentally through a non-destructive test setup and the model is validated. The estimation of overcurrent and temperature distribution among the chips can provide useful information...

  16. Other origins for the fluorescence modulation of single dye molecules in open-circuit and short-circuit devices.

    Science.gov (United States)

    Teguh, Jefri S; Kurniawan, Michael; Wu, Xiangyang; Sum, Tze Chien; Yeow, Edwin K L

    2013-01-07

    Fluorescence intensity modulation of single Atto647N dye molecules in a short-circuit device and a defective device, caused by damaging an open-circuit device, is due to a variation in the excitation light focus as a result of the formation of an alternating electric current.

  17. Mineral processing by short circuits in protoplanetary disks

    DEFF Research Database (Denmark)

    Mcnally, C.P.; Hubbard, A.; Mac Low, M.-M.

    2013-01-01

    Meteoritic chondrules were formed in the early solar system by brief heating of silicate dust to melting temperatures. Some highly refractory grains (Type B calcium-aluminum-rich inclusions, CAIs) also show signs of transient heating. A similar process may occur in other protoplanetary disks......, as evidenced by observations of spectra characteristic of crystalline silicates. One possible environment for this process is the turbulent magnetohydrodynamic flow thought to drive accretion in these disks. Such flows generally form thin current sheets, which are sites of magnetic reconnection, and dissipate...... the magnetic fields amplified by a disk dynamo. We suggest that it is possible to heat precursor grains for chondrules and other high-temperature minerals in current sheets that have been concentrated by our recently described short-circuit instability. We extend our work on this process by including...

  18. Performance of Llampuedken with short circuit and plasma loads

    International Nuclear Information System (INIS)

    Chuaqui, Hernan; Mitchell, Ian H.; Aliaga-Rossel, Raul; Favre, Mario; Wyndham, Edmund S.

    2002-01-01

    Llampuedken is a pulsed power generator designed to deliver a 1 MA, 250 ns risetime current pulse into a dense plasma load. The main novel feature of this generator is the two auxiliary transmission lines which transmit the energy not absorbed by the load, reflect it at the open end of the line and deliver it to the load when the energy from the main lines is decreasing. With the auxiliary lines an increase of 30% on the current as well as a decrease of the voltage at the load is obtained. To date Llampuedken has been operated up to the 400 kA level, into both short circuit and plasma loads. Details of actual performance of the pulse power generator are presented and compared with simulations

  19. Short circuit analysis of distribution system with integration of DG

    DEFF Research Database (Denmark)

    Su, Chi; Liu, Zhou; Chen, Zhe

    2014-01-01

    and as a result bring challenges to the network protection system. This problem has been frequently discussed in the literature, but mostly considering only the balanced fault situation. This paper presents an investigation on the influence of full converter based wind turbine (WT) integration on fault currents......Integration of distributed generation (DG) such as wind turbines into distribution system is increasing all around the world, because of the flexible and environmentally friendly characteristics. However, DG integration may change the pattern of the fault currents in the distribution system...... during both balanced and unbalanced faults. Major factors such as external grid short circuit power capacity, WT integration location, connection type of WT integration transformer are taken into account. In turn, the challenges brought to the protection system in the distribution network are presented...

  20. MINERAL PROCESSING BY SHORT CIRCUITS IN PROTOPLANETARY DISKS

    Energy Technology Data Exchange (ETDEWEB)

    McNally, Colin P. [Niels Bohr International Academy, Niels Bohr Institute, DK-2100 Copenhagen (Denmark); Hubbard, Alexander; Mac Low, Mordecai-Mark [Department of Astrophysics, American Museum of Natural History, New York, NY 10024-5192 (United States); Ebel, Denton S. [Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 10024-5192 (United States); D' Alessio, Paola, E-mail: cmcnally@nbi.dk, E-mail: ahubbard@amnh.org, E-mail: mordecai@amnh.org, E-mail: debel@amnh.org, E-mail: p.dalessio@crya.unam.mx [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, 58089 Morelia, MICH (Mexico)

    2013-04-10

    Meteoritic chondrules were formed in the early solar system by brief heating of silicate dust to melting temperatures. Some highly refractory grains (Type B calcium-aluminum-rich inclusions, CAIs) also show signs of transient heating. A similar process may occur in other protoplanetary disks, as evidenced by observations of spectra characteristic of crystalline silicates. One possible environment for this process is the turbulent magnetohydrodynamic flow thought to drive accretion in these disks. Such flows generally form thin current sheets, which are sites of magnetic reconnection, and dissipate the magnetic fields amplified by a disk dynamo. We suggest that it is possible to heat precursor grains for chondrules and other high-temperature minerals in current sheets that have been concentrated by our recently described short-circuit instability. We extend our work on this process by including the effects of radiative cooling, taking into account the temperature dependence of the opacity; and by examining current sheet geometry in three-dimensional, global models of magnetorotational instability. We find that temperatures above 1600 K can be reached for favorable parameters that match the ideal global models. This mechanism could provide an efficient means of tapping the gravitational potential energy of the protoplanetary disk to heat grains strongly enough to form high-temperature minerals. The volume-filling nature of turbulent magnetic reconnection is compatible with constraints from chondrule-matrix complementarity, chondrule-chondrule complementarity, the occurrence of igneous rims, and compound chondrules. The same short-circuit mechanism may perform other high-temperature mineral processing in protoplanetary disks such as the production of crystalline silicates and CAIs.

  1. 30 CFR 75.601-3 - Short circuit protection; dual element fuses; current ratings; maximum values.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; dual element fuses... Trailing Cables § 75.601-3 Short circuit protection; dual element fuses; current ratings; maximum values. Dual element fuses having adequate current-interrupting capacity shall meet the requirements for short...

  2. Fast-responding short circuit protection system with self-reset for use in circuit supplied by DC power

    Science.gov (United States)

    Burns, Bradley M. (Inventor); Blalock, Norman N. (Inventor)

    2011-01-01

    A short circuit protection system includes an inductor, a switch, a voltage sensing circuit, and a controller. The switch and inductor are electrically coupled to be in series with one another. A voltage sensing circuit is coupled across the switch and the inductor. A controller, coupled to the voltage sensing circuit and the switch, opens the switch when a voltage at the output terminal of the inductor transitions from above a threshold voltage to below the threshold voltage. The controller closes the switch when the voltage at the output terminal of the inductor transitions from below the threshold voltage to above the threshold voltage.

  3. A Comprehensive Investigation on the Short Circuit Performance of MW-level IGBT Power Modules

    DEFF Research Database (Denmark)

    Wu, Rui; Reigosa, Paula Diaz; Iannuzzo, Francesco

    2015-01-01

    This paper investigates the short circuit performance of commercial 1.7 kV / 1 kA IGBT power modules by means of a 6 kA Non-Destructive-Tester. A mismatched current distribution among the parallel chips has been observed, which can reduce the short circuit capability of the IGBT power module unde...... short circuit conditions. Further Spice simulations reveal that the stray parameters inside the module play an important role in contributing to such a phenomenon....

  4. Integrated Power Flow and Short Circuit Calculation Method for Distribution Network with Inverter Based Distributed Generation

    OpenAIRE

    Yang, Shan; Tong, Xiangqian

    2016-01-01

    Power flow calculation and short circuit calculation are the basis of theoretical research for distribution network with inverter based distributed generation. The similarity of equivalent model for inverter based distributed generation during normal and fault conditions of distribution network and the differences between power flow and short circuit calculation are analyzed in this paper. Then an integrated power flow and short circuit calculation method for distribution network with inverte...

  5. Three-phase short circuit calculation method based on pre-computed surface for doubly fed induction generator

    Science.gov (United States)

    Ma, J.; Liu, Q.

    2018-02-01

    This paper presents an improved short circuit calculation method, based on pre-computed surface to determine the short circuit current of a distribution system with multiple doubly fed induction generators (DFIGs). The short circuit current, injected into power grid by DFIG, is determined by low voltage ride through (LVRT) control and protection under grid fault. However, the existing methods are difficult to calculate the short circuit current of DFIG in engineering practice due to its complexity. A short circuit calculation method, based on pre-computed surface, was proposed by developing the surface of short circuit current changing with the calculating impedance and the open circuit voltage. And the short circuit currents were derived by taking into account the rotor excitation and crowbar activation time. Finally, the pre-computed surfaces of short circuit current at different time were established, and the procedure of DFIG short circuit calculation considering its LVRT was designed. The correctness of proposed method was verified by simulation.

  6. Open circuit voltage-decay behavior in amorphous p-i-n solar due to injection

    Science.gov (United States)

    Smrity, Manu; Dhariwal, S. R.

    2018-05-01

    The paper deals with the basic recombination processes at the dangling bond and the band tail states at various levels of injection, expressed in terms of short-circuit current density and their role in the behavior of amorphous solar cells. As the level of injection increases the fill factor decreases whereas the open circuit voltage increases very slowly, showing a saturation tendency. Calculations have been done for two values of tail state densities and shows that with an increase in tail state densities both, the fill factor and open circuit voltage decreases, results an overall degradation of the solar cell.

  7. Device for testing continuity and/or short circuits in a cable

    Science.gov (United States)

    Hayhurst, Arthur R. (Inventor)

    1995-01-01

    A device for testing current paths is attachable to a conductor. The device automatically checks the current paths of the conductor for continuity of a center conductor, continuity of a shield and a short circuit between the shield and the center conductor. The device includes a pair of connectors and a circuit to provide for testing of the conductive paths of the cable. The pair of connectors electrically connects the conductive paths of a cable to be tested with the circuit paths of the circuit. The circuit paths in the circuit include indicators to simultaneously indicate the results of the testing.

  8. Representative-Sandwich Model for Mechanical-Crush and Short-Circuit Simulation of Lithium-ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao; Santhanagopalan, Shriram; Sprague, Michael A.; Pesaran, Ahmad A.

    2015-07-28

    Lithium-ion batteries are currently the state-of-the-art power sources for a variety of applications, from consumer electronic devices to electric-drive vehicles (EDVs). Being an energized component, failure of the battery is an essential concern, which can result in rupture, smoke, fire, or venting. The failure of Lithium-ion batteries can be due to a number of external abusive conditions (impact/crush, overcharge, thermal ramp, etc.) or internal conditions (internal short circuits, excessive heating due to resistance build-up, etc.), of which the mechanical-abuse-induced short circuit is a very practical problem. In order to better understand the behavior of Lithium-ion batteries under mechanical abuse, a coupled modeling methodology encompassing the mechanical, thermal and electrical response has been developed for predicting short circuit under external crush.

  9. Approximative calculation of transient short-circuit currents in power-systems

    Energy Technology Data Exchange (ETDEWEB)

    Heuck, K; Rosenberger, R; Dettmann, K D; Kegel, R

    1986-08-01

    The paper shows that it is approximatively possible to calculate the transient short-circuit currents for symmetrical and asymmetrical faults in power-systems. For that purpose a simple equivalent network is found. Its error of approximation is small. For the important maximum short-circuit current limits of error are pointed out compared to VDE 0102.

  10. Thirteen years test experience with short-circuit withstand capability of large power transformers

    NARCIS (Netherlands)

    Smeets, R.P.P.; Paske, te L.H.; Leufkens, P.P.; Fogelberg, T.

    2009-01-01

    The ability to withstand a short circuit is recognised more and more as an essential characteristic of power transformers. IEC and IEEE Standards, as well as other national standards specify short-circuit testing and how to check the withstand capability. Unfortunately, however, there is extensive

  11. Built-in unit with short-circuit insulation for hermetic cable ducts

    International Nuclear Information System (INIS)

    Tschacher, B.; Gurr, W.; Kusserow, J.; Katzmarek, W.

    1984-01-01

    The invention concerns a built-in unit with short-circuit insulation for hermetic cable ducts, especially for containments of nuclear power reactors. The short-circuit insulation is achieved by an insulation plate made from radiation-resistant insulating materials of high mechanical strength

  12. Fourteen years of test experience with short-circuit withstand capability of large power transformers

    NARCIS (Netherlands)

    Smeets, R.P.P.; Paske, te L.H.

    2010-01-01

    Experience is reported of short-circuit testing of large power transformers during the past 14 years by KEMA in the Netherlands. In total, 119 transformers > 25 MVA participated in the survey. KEMA shows that at initial access to standard IEC short-circuit tests, 28% failed initially in a wide range

  13. On-line diagnosis of inter-turn short circuit fault for DC brushed motor.

    Science.gov (United States)

    Zhang, Jiayuan; Zhan, Wei; Ehsani, Mehrdad

    2018-06-01

    Extensive research effort has been made in fault diagnosis of motors and related components such as winding and ball bearing. In this paper, a new concept of inter-turn short circuit fault for DC brushed motors is proposed to include the short circuit ratio and short circuit resistance. A first-principle model is derived for motors with inter-turn short circuit fault. A statistical model based on Hidden Markov Model is developed for fault diagnosis purpose. This new method not only allows detection of motor winding short circuit fault, it can also provide estimation of the fault severity, as indicated by estimation of the short circuit ratio and the short circuit resistance. The estimated fault severity can be used for making appropriate decisions in response to the fault condition. The feasibility of the proposed methodology is studied for inter-turn short circuit of DC brushed motors using simulation in MATLAB/Simulink environment. In addition, it is shown that the proposed methodology is reliable with the presence of small random noise in the system parameters and measurement. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Sixteen years of test experiences with short-circuit withstand capability of large power transformers

    NARCIS (Netherlands)

    Smeets, R.P.P.; Paske, te L.H.

    2012-01-01

    Experience is reported of short-circuit testing of large power transformers during the past 16 years by KEMA in the Netherlands. In total, 174 transformers > 25 MVA participated in the survey. KEMA shows that at initial access to standard IEC short-circuit tests, 24% failed initially in a wide range

  15. Neural circuit mechanisms of short-term memory

    Science.gov (United States)

    Goldman, Mark

    Memory over time scales of seconds to tens of seconds is thought to be maintained by neural activity that is triggered by a memorized stimulus and persists long after the stimulus is turned off. This presents a challenge to current models of memory-storing mechanisms, because the typical time scales associated with cellular and synaptic dynamics are two orders of magnitude smaller than this. While such long time scales can easily be achieved by bistable processes that toggle like a flip-flop between a baseline and elevated-activity state, many neuronal systems have been observed experimentally to be capable of maintaining a continuum of stable states. For example, in neural integrator networks involved in the accumulation of evidence for decision making and in motor control, individual neurons have been recorded whose activity reflects the mathematical integral of their inputs; in the absence of input, these neurons sustain activity at a level proportional to the running total of their inputs. This represents an analog form of memory whose dynamics can be conceptualized through an energy landscape with a continuum of lowest-energy states. Such continuous attractor landscapes are structurally non-robust, in seeming violation of the relative robustness of biological memory systems. In this talk, I will present and compare different biologically motivated circuit motifs for the accumulation and storage of signals in short-term memory. Challenges to generating robust memory maintenance will be highlighted and potential mechanisms for ameliorating the sensitivity of memory networks to perturbations will be discussed. Funding for this work was provided by NIH R01 MH065034, NSF IIS-1208218, Simons Foundation 324260, and a UC Davis Ophthalmology Research to Prevent Blindness Grant.

  16. Resonant magnetoelectric response of composite cantilevers: Theory of short vs. open circuit operation and layer sequence effects

    Directory of Open Access Journals (Sweden)

    Matthias C. Krantz

    2015-11-01

    Full Text Available The magnetoelectric effect in layered composite cantilevers consisting of strain coupled layers of magnetostrictive (MS, piezoelectric (PE, and substrate materials is investigated for magnetic field excitation at bending resonance. Analytic theories are derived for the transverse magnetoelectric (ME response in short and open circuit operation for three different layer sequences and results presented and discussed for the FeCoBSi-AlN-Si and the FeCoBSi-PZT-Si composite systems. Response optimized PE-MS layer thickness ratios are found to greatly change with operation mode shifting from near equal MS and PE layer thicknesses in the open circuit mode to near vanishing PE layer thicknesses in short circuit operation for all layer sequences. In addition the substrate layer thickness is found to differently affect the open and short circuit ME response producing shifts and reversal between ME response maxima depending on layer sequence. The observed rich ME response behavior for different layer thicknesses, sequences, operating modes, and PE materials can be explained by common neutral plane effects and different elastic compliance effects in short and open circuit operation.

  17. THE RATE OF CURRENT CHANGE DURING A SHORT CIRCUIT IN THE POWER CIRCUITS OF THE ELECTRIC ROLLING STOCK WITH REGARD TO EDDY CURRENTS

    Directory of Open Access Journals (Sweden)

    L. V. Dubinets

    2010-04-01

    Full Text Available In the article the issue of influence of vortical currents on rate of change of short circuit current is considered, a mathematical model for the calculation of short circuit currents in the traction mode in the power circuits of DC electric rolling stock is presented, and the research results are given.

  18. Modification of feeding circuits in the evolution of social behavior.

    Science.gov (United States)

    Fischer, Eva K; O'Connell, Lauren A

    2017-01-01

    Adaptive trade-offs between foraging and social behavior intuitively explain many aspects of individual decision-making. Given the intimate connection between social behavior and feeding/foraging at the behavioral level, we propose that social behaviors are linked to foraging on a mechanistic level, and that modifications of feeding circuits are crucial in the evolution of complex social behaviors. In this Review, we first highlight the overlap between mechanisms underlying foraging and parental care and then expand this argument to consider the manipulation of feeding-related pathways in the evolution of other complex social behaviors. We include examples from diverse taxa to highlight that the independent evolution of complex social behaviors is a variation on the theme of feeding circuit modification. © 2017. Published by The Company of Biologists Ltd.

  19. Modulation of short-term plasticity in the corticothalamic circuit by group III metabotropic glutamate receptors.

    Science.gov (United States)

    Kyuyoung, Christine L; Huguenard, John R

    2014-01-08

    Recurrent connections in the corticothalamic circuit underlie oscillatory behavior in this network and range from normal sleep rhythms to the abnormal spike-wave discharges seen in absence epilepsy. The propensity of thalamic neurons to fire postinhibitory rebound bursts mediated by low-threshold calcium spikes renders the circuit vulnerable to both increased excitation and increased inhibition, such as excessive excitatory cortical drive to thalamic reticular (RT) neurons or heightened inhibition of thalamocortical relay (TC) neurons by RT. In this context, a protective role may be played by group III metabotropic receptors (mGluRs), which are uniquely located in the presynaptic active zone and typically act as autoreceptors or heteroceptors to depress synaptic release. Here, we report that these receptors regulate short-term plasticity at two loci in the corticothalamic circuit in rats: glutamatergic cortical synapses onto RT neurons and GABAergic synapses onto TC neurons in somatosensory ventrobasal thalamus. The net effect of group III mGluR activation at these synapses is to suppress thalamic oscillations as assayed in vitro. These findings suggest a functional role of these receptors to modulate corticothalamic transmission and protect against prolonged activity in the network.

  20. Evaporating short-circuits in the ATLAS liquid argon barrel presampler 006

    CERN Document Server

    Belhorma, B; Lund-Jensen, B; Rydström, S; Yamouni, M

    2005-01-01

    A technique to eliminate or limit the implications of short-circuits in the ATLAS barrel presampler is described. A high voltage capacitor with a large capacity is charged at different high voltages and discharged through the short-circuit which allows either to disintegrate the dust being the origin of the short-circuit, or to burn away a thin etched copper strip which acts as a fuse on the corresponding presampler anode. This effect is possible even in the presence of a resistive HV cable (10 to 30 ohms) in series which dampens the pulse.

  1. Direct observation of short-circuit diffusion during the formation of a single cupric oxide nanowire

    International Nuclear Information System (INIS)

    Cheng, C-L; Ma, Y-R; Chou, M H; Huang, C Y; Yeh, V; Wu, S Y

    2007-01-01

    Short-circuit diffusion was observed in a single CuO nanowire synthesized using a thermal oxidation method. The confocal Raman spectra of a single CuO nanowire permit direct observation of the nature of an individual CuO nanowire. The parameter order obtained from the inverse Raman B g 2 peak linewidth results in the length dependence of the linewidth and a short-circuit diffusion length of 3.3 μm. The observed structural information is also consistent with the energy dispersive x-ray spectroscopic mapping. The results confirm that the growth of CuO nanowires occurs through the short-circuit diffusion mechanism

  2. Non-Destructive Investigation on Short Circuit Capability of Wind-Turbine-Scale IGBT Power Modules

    DEFF Research Database (Denmark)

    Wu, Rui; Iannuzzo, Francesco; Wang, Huai

    2014-01-01

    This paper presents a comprehensive investigation on the short circuit capability of wind-turbine-scale IGBT power modules by means of a 6 kA/1.1 kV non-destructive testing system. A Field Programmable Gate Array (FPGA) supervising unit is adpoted to achieve an accurate time control for short...... circuit test, which enables to define the driving signals with an accuracy of 10 ns. Thanks to the capability and the effectiveness of the constructed setup, oscillations appearing during short circuits of the new-generation 1.7 kV/1 kA IGBT power modules have been evidenced and characterized under...

  3. Clearance of short circuited ion optics electrodes by capacitive discharge. [in ion thrusters

    Science.gov (United States)

    Poeschel, R. L.

    1976-01-01

    The ion optics electrodes of low specific impulse (3000 sec) mercury electron bombardment ion thrusters are vulnerable to short circuits by virtue of their relatively small interelectrode spacing (0.5 mm). Metallic flakes from backsputtered deposits are the most probable cause of such 'shorts' and 'typical' flakes have been simulated here using refractory wire that has a representative, but controllable, cross section. Shorting wires can be removed by capacitive discharge without significant damage to the electrodes. This paper describes an evaluation of 'short' removal versus electrode damage for several combinations of capacitor voltage, stored energy, and short circuit conditions.

  4. Predicting the behavior of microfluidic circuits made from discrete elements

    Science.gov (United States)

    Bhargava, Krisna C.; Thompson, Bryant; Iqbal, Danish; Malmstadt, Noah

    2015-10-01

    Microfluidic devices can be used to execute a variety of continuous flow analytical and synthetic chemistry protocols with a great degree of precision. The growing availability of additive manufacturing has enabled the design of microfluidic devices with new functionality and complexity. However, these devices are prone to larger manufacturing variation than is typical of those made with micromachining or soft lithography. In this report, we demonstrate a design-for-manufacturing workflow that addresses performance variation at the microfluidic element and circuit level, in context of mass-manufacturing and additive manufacturing. Our approach relies on discrete microfluidic elements that are characterized by their terminal hydraulic resistance and associated tolerance. Network analysis is employed to construct simple analytical design rules for model microfluidic circuits. Monte Carlo analysis is employed at both the individual element and circuit level to establish expected performance metrics for several specific circuit configurations. A protocol based on osmometry is used to experimentally probe mixing behavior in circuits in order to validate these approaches. The overall workflow is applied to two application circuits with immediate use at on the bench-top: series and parallel mixing circuits that are modularly programmable, virtually predictable, highly precise, and operable by hand.

  5. Predicting the behavior of microfluidic circuits made from discrete elements.

    Science.gov (United States)

    Bhargava, Krisna C; Thompson, Bryant; Iqbal, Danish; Malmstadt, Noah

    2015-10-30

    Microfluidic devices can be used to execute a variety of continuous flow analytical and synthetic chemistry protocols with a great degree of precision. The growing availability of additive manufacturing has enabled the design of microfluidic devices with new functionality and complexity. However, these devices are prone to larger manufacturing variation than is typical of those made with micromachining or soft lithography. In this report, we demonstrate a design-for-manufacturing workflow that addresses performance variation at the microfluidic element and circuit level, in context of mass-manufacturing and additive manufacturing. Our approach relies on discrete microfluidic elements that are characterized by their terminal hydraulic resistance and associated tolerance. Network analysis is employed to construct simple analytical design rules for model microfluidic circuits. Monte Carlo analysis is employed at both the individual element and circuit level to establish expected performance metrics for several specific circuit configurations. A protocol based on osmometry is used to experimentally probe mixing behavior in circuits in order to validate these approaches. The overall workflow is applied to two application circuits with immediate use at on the bench-top: series and parallel mixing circuits that are modularly programmable, virtually predictable, highly precise, and operable by hand.

  6. Cage-rotor induction motor inter-turn short circuit fault detection with and without saturation effect by MEC model.

    Science.gov (United States)

    Naderi, Peyman

    2016-09-01

    The inter-turn short fault for the Cage-Rotor-Induction-Machine (CRIM) is studied in this paper and its local saturation is taken into account. However, in order to observe the exact behavior of machine, the Magnetic-Equivalent-Circuit (MEC) and nonlinear B-H curve are proposed to provide an insight into the machine model and saturation effect respectively. The electrical machines are generally operated near to their saturation zone due to some design necessities. Hence, when the machine is exposed to a fault such as short circuit or eccentricities, it is operated within its saturation zone and thus, time and space harmonics are integrated and as a result, current and torque harmonics are generated which the phenomenon cannot be explored when saturation is dismissed. Nonetheless, inter-turn short circuit may lead to local saturation and this occurrence is studied in this paper using MEC model. In order to achieve the mentioned objectives, two and also four-pole machines are modeled as two samples and the machines performances are analyzed in healthy and faulty cases with and without saturation effect. A novel strategy is proposed to precisely detect inter-turn short circuit fault according to the stator׳s lines current signatures and the accuracy of the proposed method is verified by experimental results. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Short Circuits of a 10 MW High Temperature Superconducting Wind Turbine Generator

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Liu, Dong; Polinder, Henk

    2016-01-01

    Direct drive high temperature superconducting (HTS) wind turbine generators have been proposed to tackle challenges for ever increasing wind turbine ratings. Due to smaller reactances in HTS generators, higher fault currents and larger transient torques could occur if sudden short circuits happen...... at generator terminals. In this paper, a finite element model that couples magnetic fields and the generator’s equivalent circuits is developed to simulate short circuit faults. Afterwards, the model is used to study the transient performance of a 10 MW HTS wind turbine generator under four different short...... that the short circuits pose great challenges to the generator, and careful consideration should be given to protect the generator. The results presented in this paper would be beneficial to the design, operation and protection of an HTS wind turbine generator....

  8. PSPICE simulation of bipolar pulse converter based on short-circuited coaxial transmission line

    International Nuclear Information System (INIS)

    Shi Lei; Fan Yajun

    2010-01-01

    The operating principle of the bipolar pulse converter based on short-circuited coaxial transmission line type is given. The output bipolar pulses are simulated by using PSPICE program on condition of different electric length and different impedance of the short-circuited coaxial transmission line. The bipolar pulses are generated by using unipolar pulse with pulse width of 2 ns in experiment, the experimental result fit well with the simulation result. (authors)

  9. Modeling of Short-Circuit-Related Thermal Stress in Aged IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Iannuzzo, Francesco; Uhrenfeldt, Christian

    2017-01-01

    In this paper, the thermal stress on bond wires of aged IGBT modules under short-circuit conditions has been studied with respect to different solder delamination levels. To ensure repeatable test conditions, ad-hoc DBC (direct bond copper) samples with delaminated solder layers have been purposely...... in the surface temperature distribution, which confirms the hypothesis that short-circuit events produce significantly uneven stresses on bond wires....

  10. Prediction of Short-Circuit-Related Thermal Stress in Aged IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Iannuzzo, Francesco; Uhrenfeldt, Christian

    2016-01-01

    In this paper, the thermal stress on bond wires of aged IGBT modules under short-circuit conditions has been studied with respect to different solder delamination levels. To ensure repeatable test conditions, ad-hoc DBC (direct bond copper) samples with delaminated solder layers have been purposely...... in the surface temperature distribution which confirms the hypothesis that short-circuit events produce significantly uneven stresses on bond wires....

  11. Short-Circuit Current Analysis for DFIG Wind Farm Considering the Action of a Crowbar

    Directory of Open Access Journals (Sweden)

    Yan Hong Yuan

    2018-02-01

    Full Text Available With the increasing capacity of wind farms integrated into the power grid, the short-circuit current analysis for wind farms becomes more and more important. Since the wind turbine is usually integrated into the power grid via power electronic devices, the “crowbar” is installed in the wind turbine to protect the power electronic devices and to improve the fault ride through capability. The impact of the crowbar has to be considered during the short-circuit current analysis for the wind farm. In order to fully analyze the short-circuit current characteristics of a wind farm, the short-circuit currents for a doubly-fed induction generator (DFIG wind turbine under symmetrical and asymmetrical faults considering the crowbar action characteristic are derived firstly. Then the action situation of the crowbar of a DFIG wind turbine is studied and the action area curve is obtained. Taking the crowbar action, or not, as the grouping criterion, wind turbines in the wind farm are divided into two groups, and the wind farm is aggregated into two equivalent wind turbines. Using the equivalent model, the short-circuit current of a wind farm can be calculated accurately. Finally, simulations are performed in MATLAB/Simulink which is the commercial math software produced by the MathWorks company in Natick, Massachusetts, the United States to verify the proposed short-circuit current calculation method for the DFIG wind farm.

  12. Minimum short-circuit ratios for grid interconnection of wind farms with induction generators

    Energy Technology Data Exchange (ETDEWEB)

    Reginatto, Romeu; Rocha, Carlos [Western Parana State University (UNIOESTE), Foz do Iguacu, PR (Brazil). Center for Engineering and Exact Sciences], Emails: romeu@unioeste.br, croberto@unioeste.br

    2009-07-01

    This paper concerns the problem of determining the minimum value for the short-circuit ratio which is adequate for the interconnection of a given wind farms to a given grid point. First, a set of 3 criteria is defined in order to characterize the quality/safety of the interconnection: acceptable terminal voltage variations, a minimum active power margin, and an acceptable range for the internal voltage angle. Then, the minimum short circuit ratio requirement is determined for 6 different induction generator based wind turbines, both fixed-speed (with and without reactive power compensation) and variable-speed (with the following control policies: reactive power, power factor, and terminal voltage regulation). The minimum short-circuit ratio is determined and shown in graphical results for the 6 wind turbines considered, for X/R in the range 0-15, also analyzing the effect of more/less stringent tolerances for the interconnection criteria. It is observed that the tighter the tolerances the larger the minimum short-circuit ratio required. For the same tolerances in the interconnection criteria, a comparison of the minimum short circuit ratio required for the interconnection of both squirrel-cage and doubly-fed induction generators is presented, showing that the last requires much smaller values for the short-circuit ratio. (author)

  13. Oxygenator in short-term LVAD circuit: a rescue in post-LVAD pulmonary complications.

    Science.gov (United States)

    Mohite, Prashant N; Patil, Nikhil P; Popov, Aron-Frederik; Bahrami, Toufan; Simon, Andre R

    2016-10-01

    Pulmonary complications after left ventricular assist device (LVAD) implantation, though infrequent, can be potentially catastrophic. A 62-year-old female with cardiogenic shock, supported on short-term LVAD, developed pulmonary oedema. An oxygenator was introduced into the LVAD circuit, which improved the gas exchange and, eventually, after weaning off the oxygenator, the patient received long-term LVAD. The introduction of an oxygenator into the short-term LAVD circuit is a lifesaving manoeuvre in such a situation. It offers freedom of introducing and removing the oxygenator into the LVAD circuit without opening the chest and competing for LVAD flow. © The Author(s) 2016.

  14. Short Circuits of a 10-MW High-Temperature Superconducting Wind Turbine Generator

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Liu, Dong; Polinder, Henk

    2017-01-01

    Direct Drive high-temperature superconducting (HTS) wind turbine generators have been proposed to tackle challenges for ever increasing wind turbine ratings. Due to smaller reactances in HTS generators, higher fault currents and larger transient torques could occur if sudden short circuits take...... place at generator terminals. In this paper, a finite element model that couples magnetic fields and the generator's equivalent circuits is developed to simulate short-circuit faults. Afterward, the model is used to study the transient performance of a 10-MW HTS wind turbine generator under four...... show that the short circuits pose great challenges to the generator, and careful consideration should be given to protect the generator. The findings presented in this paper would be beneficial to the design, operation and protection of an HTS wind turbine generator....

  15. Measuring RF circuits exhibiting nonlinear responses combined with short and long term memory effects

    NARCIS (Netherlands)

    Janssen, E.J.G.; Milosevic, D.; Baltus, P.G.M.

    2010-01-01

    All RF circuits that incorporate active devices exhibit nonlinear behavior. Nonlinearities result in signal distortion, and therefore state the upper limit of the dynamic range of the circuits. A measure for linearity used quite commonly in RF is the P1dB and/or IP3 point. These quantities are

  16. The Simulation Computer Based Learning (SCBL) for Short Circuit Multi Machine Power System Analysis

    Science.gov (United States)

    Rahmaniar; Putri, Maharani

    2018-03-01

    Strengthening Competitiveness of human resources become the reply of college as a conductor of high fomal education. Electrical Engineering Program UNPAB (Prodi TE UNPAB) as one of the department of electrical engineering that manages the field of electrical engineering expertise has a very important part in preparing human resources (HR), Which is required by where graduates are produced by DE UNPAB, Is expected to be able to compete globally, especially related to the implementation of Asean Economic Community (AEC) which requires the active participation of graduates with competence and quality of human resource competitiveness. Preparation of HR formation Competitive is done with the various strategies contained in the Seven (7) Higher Education Standard, one part of which is the implementation of teaching and learning process in Electrical system analysis with short circuit analysis (SCA) This course is a course The core of which is the basis for the competencies of other subjects in the advanced semester at Development of Computer Based Learning model (CBL) is done in the learning of interference analysis of multi-machine short circuit which includes: (a) Short-circuit One phase, (B) Two-phase Short Circuit Disruption, (c) Ground Short Circuit Disruption, (d) Short Circuit Disruption One Ground Floor Development of CBL learning model for Electrical System Analysis course provides space for students to be more active In learning in solving complex (complicated) problems, so it is thrilling Ilkan flexibility of student learning how to actively solve the problem of short-circuit analysis and to form the active participation of students in learning (Student Center Learning, in the course of electrical power system analysis.

  17. Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

    Science.gov (United States)

    Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

    2010-01-01

    To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish .

  18. Short circuit detection in the winding and operation of superconducting magnets

    International Nuclear Information System (INIS)

    Walstrom, P.L.

    1982-01-01

    Three categories of shorts will be discussed: (1) shorts to the metallic bobbin or other structural elements, (2) shorts between turns caused by instrumentation wires that are deliberately connected to a turn at the end (e.g., voltage taps) and that short out to another turn but are not completely severed in the process, and (3) short circuits between turns caused by direct contact due to insulation failure by chips of metal bridging turns and by instrumentation wires that bridge turns but are severed in the process of shorting

  19. Detection Method for Soft Internal Short Circuit in Lithium-Ion Battery Pack by Extracting Open Circuit Voltage of Faulted Cell

    Directory of Open Access Journals (Sweden)

    Minhwan Seo

    2018-06-01

    Full Text Available Early detection of internal short circuit which is main cause of thermal runaway in a lithium-ion battery is necessary to ensure battery safety for users. As a promising fault index, internal short circuit resistance can directly represent degree of the fault because it describes self-discharge phenomenon caused by the internal short circuit clearly. However, when voltages of individual cells in a lithium-ion battery pack are not provided, the effect of internal short circuit in the battery pack is not readily observed in whole terminal voltage of the pack, leading to difficulty in estimating accurate internal short circuit resistance. In this paper, estimating the resistance with the whole terminal voltages and the load currents of the pack, a detection method for the soft internal short circuit in the pack is proposed. Open circuit voltage of a faulted cell in the pack is extracted to reflect the self-discharge phenomenon obviously; this process yields accurate estimates of the resistance. The proposed method is verified with various soft short conditions in both simulations and experiments. The error of estimated resistance does not exceed 31.2% in the experiment, thereby enabling the battery management system to detect the internal short circuit early.

  20. Internal Short Circuits in Lithium-Ion Cells for PHEVs

    Energy Technology Data Exchange (ETDEWEB)

    Sriramulu, Suresh [Tiax LLC, Lexington, MA (United States); Stringfellow, Richard [Tiax LLC, Lexington, MA (United States)

    2013-05-25

    Development of Plug-in Hybrid Electric Vehicles (PHEVs) has recently become a high national priority because of their potential to enable significantly reduced petroleum consumption by the domestic transportation sector in the relatively near term. Lithium-ion (Li-ion) batteries are a critical enabling technology for PHEVs. Among battery technologies with suitable operating characteristics for use in vehicles, Li-ion batteries offer the best combination of energy, power, life and cost. Consequently, worldwide, leading corporations and government agencies are supporting the development of Li-ion batteries for PHEVs, as well as the full spectrum of vehicular applications ranging from mild hybrid to all-electric. In this project, using a combination of well-defined experiments, custom designed cells and simulations, we have improved the understanding of the process by which a Li-ion cell that develops an internal short progresses to thermal runaway. Using a validated model for thermal runaway, we have explored the influence of environmental factors and cell design on the propensity for thermal runaway in full-sized PHEV cells. We have also gained important perspectives about internal short development and progression; specifically that initial internal shorts may be augmented by secondary shorts related to separator melting. Even though the nature of these shorts is very stochastic, we have shown the critical and insufficiently appreciated role of heat transfer in influencing whether a developing internal short results in a thermal runaway. This work should lead to enhanced perspectives on separator design, the role of active materials and especially cathode materials with respect to safety and the design of automotive cooling systems to enhance battery safety in PHEVs.

  1. Method of repair of short circuits for in-situ leaching

    International Nuclear Information System (INIS)

    Baughman, D.R.; Bergeson, J.R.

    1984-01-01

    In an acidic in-situ leaching system, a short circuit passage through a subterranean formation between a fracture associated with an injection well and a fracture associated with a production well can be plugged by introducing a non-acidic liquid for displacing acidic leach liquid from the short circuit passage, introducing into the injection well a basic composition including a sealing material that gels under acidic conditions, and introducing sufficient liquid into the injection well to displace at least a portion of the basic composition containing sealing material from the injection well into the short circuit passage. Liquid flow between the injection well and the production well is then discontinued for a sufficient time for residual acid in the subterranean formation surrounding the short circuit passage to contact the sealing material and cause gelation of the sealing material in the short circuit passage. The introduction of acidic leach liquid to the formation can then continue. The sealing material may be a polymer or a water soluble silicate

  2. Short-circuit protection of LLC resonant converter using voltages across resonant tank elements

    Directory of Open Access Journals (Sweden)

    Denys Igorovych Zaikin

    2015-06-01

    Full Text Available This paper describes two methods for the short-circuit protection of the LLC resonant converter. One of them uses the voltage across the capacitor and the other uses the voltage across the inductor of the resonant tank. These voltages can be processed (integrated or differentiated to recover the resonant tank current. The two circuits illustrated in the described methods make it possible to develop a robust LLC converter design and to avoid using lossy current measurement elements, such as a shunt resistor or current transformer. The methods also allow measuring resonant tank current without breaking high-current paths and connecting the measuring circuit in parallel with the inductor or capacitor of the resonant tank. Practical implementations of these indirect current measurements have been experimentally tested for the short-circuit protection of the 1600 W LLC converter.

  3. Short Circuit Ratio analysis of multi-infeed HVDC system with a VSC-HVDC link

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2011-01-01

    As an important indicator of system stability, Short Circuit Ratio (SCR) is commonly used in power system analysis. For systems include HVDC link connection, the Effective SCR (ESCR) is mostly applied to indicate the strength of HVDC infeed bus. The contribution of VSC-HVDC link to multi......-infeed HVDC system stability has been analyzed a lot but the study on ESCR of this kind of system is still insufficient. This paper presents a calculation method for ESCR of the hybrid multi infeed HVDC system based on a simple two-infeed HVDC system model. The equivalent circuit of this system under short...... circuit situation is firstly obtained based on the model. Then its Thevenin equivalent circuit is derived and system ESCR can be calculated. At last, simulation study verified that the calculated ESCR value under different cases can indicate the change of system stability....

  4. Apparatus including a plurality of spaced transformers for locating short circuits in cables

    Science.gov (United States)

    Cason, R. L.; Mcstay, J. J. (Inventor)

    1978-01-01

    A cable fault locator is described for sensing faults such as short circuits in power cables. The apparatus includes a plurality of current transformers strategically located along a cable. Trigger circuits are connected to each of the current transformers for placing a resistor in series with a resistive element responsive to an abnormally high current flowing through that portion of the cable. By measuring the voltage drop across the resistive element, the location of the fault can be determined.

  5. Alterations in Striatal Circuits Underlying Addiction-Like Behaviors.

    Science.gov (United States)

    Kim, Hyun Jin; Lee, Joo Han; Yun, Kyunghwa; Kim, Joung-Hun

    2017-06-30

    Drug addiction is a severe psychiatric disorder characterized by the compulsive pursuit of drugs of abuse despite potential adverse consequences. Although several decades of studies have revealed that psychostimulant use can result in extensive alterations of neural circuits and physiology, no effective therapeutic strategies or medicines for drug addiction currently exist. Changes in neuronal connectivity and regulation occurring after repeated drug exposure contribute to addiction-like behaviors in animal models. Among the involved brain areas, including those of the reward system, the striatum is the major area of convergence for glutamate, GABA, and dopamine transmission, and this brain region potentially determines stereotyped behaviors. Although the physiological consequences of striatal neurons after drug exposure have been relatively well documented, it remains to be clarified how changes in striatal connectivity underlie and modulate the expression of addiction-like behaviors. Understanding how striatal circuits contribute to addiction-like behaviors may lead to the development of strategies that successfully attenuate drug-induced behavioral changes. In this review, we summarize the results of recent studies that have examined striatal circuitry and pathway-specific alterations leading to addiction-like behaviors to provide an updated framework for future investigations.

  6. Fault Detection and Location of IGBT Short-Circuit Failure in Modular Multilevel Converters

    Directory of Open Access Journals (Sweden)

    Bin Jiang

    2018-06-01

    Full Text Available A single fault detection and location for Modular Multilevel Converter (MMC is of great significance, as numbers of sub-modules (SMs in MMC are connected in series. In this paper, a novel fault detection and location method is proposed for MMC in terms of the Insulated Gate Bipolar Translator (IGBT short-circuit failure in SM. The characteristics of IGBT short-circuit failures are analyzed, based on which a Differential Comparison Low-Voltage Detection Method (DCLVDM is proposed to detect the short-circuit fault. Lastly, the faulty IGBT is located based on the capacitor voltage of the faulty SM by Continuous Wavelet Transform (CWT. Simulations have been done in the simulation software PSCAD/EMTDC and the results confirm the validity and reliability of the proposed method.

  7. In-situ short-circuit protection system and method for high-energy electrochemical cells

    Science.gov (United States)

    Gauthier, Michel; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Rouillard, Jean; Rouillard, Roger; Shiota, Toshimi; Trice, Jennifer L.

    2003-04-15

    An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

  8. In-situ short circuit protection system and method for high-energy electrochemical cells

    Science.gov (United States)

    Gauthier, Michel; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Rouillard, Jean; Rouillard, Roger; Shiota, Toshimi; Trice, Jennifer L.

    2000-01-01

    An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

  9. Data on the natural ventilation performance of windcatcher with anti-short-circuit device (ASCD).

    Science.gov (United States)

    Nejat, Payam; Calautit, John Kaiser; Majid, Muhd Zaimi Abd; Hughes, Ben Richard; Jomehzadeh, Fatemeh

    2016-12-01

    This article presents the datasets which were the results of the study explained in the research paper 'Anti-short-circuit device: a new solution for short-circuiting in windcatcher and improvement of natural ventilation performance' (P. Nejat, J.K. Calautit, M.Z. Abd. Majid, B.R. Hughes, F. Jomehzadeh, 2016) [1] which introduces a new technique to reduce or prevent short-circuiting in a two-sided windcatcher and also lowers the indoor CO2 concentration and improve the ventilation distribution. Here, we provide details of the numerical modeling set-up and data collection method to facilitate reproducibility. The datasets includes indoor airflow, ventilation rates and CO2 concentration data at several points in the flow field. The CAD geometry of the windcatcher models are also included.

  10. Modelling the short-circuit current of polymer bulk heterojunction solar cells

    International Nuclear Information System (INIS)

    Geens, Wim; Martens, Tom; Poortmans, Jef; Aernouts, Tom; Manca, Jean; Lutsen, Laurence; Heremans, Paul; Borghs, Staf; Mertens, Robert; Vanderzande, Dirk

    2004-01-01

    An analytical model has been developed to estimate the short-circuit current density of conjugated polymer/fullerene bulk heterojunction solar cells. The model takes into account the solvent-dependent molecular morphology of the donor/acceptor blend, which was revealed by transmission electron microscopy. Field-effect transistors based on single and composite organic layers were fabricated to determine values for the charge carrier mobilities of such films. These values served as input parameters of the model. It is shown that the difference in short-circuit current density that was measured between toluene-cast and chlorobenzene-cast conjugated polymer/fullerene photovoltaic cells (Appl. Phys. Lett. 78 (2001) 841) could be very well simulated with the model. Moreover, the calculations illustrate how increasing the hole and electron mobilities in the photoactive blend can improve the overall short-circuit current density of the solar cell

  11. Allocation of synchronous condensers for restoration of system short-circuit power

    DEFF Research Database (Denmark)

    Marrazi, Emanuel; Yang, Guangya; Weinreich-Jensen, Peter

    2017-01-01

    Modern power systems, employing an increasing number of converter-based renewable energy sources (RES) and decreasing the usage of conventional power plants, are leading to lower levels of short-circuit power and rotational inertia. A solution to this is the employment of synchronous condensers...... in the grid, in order to provide sufficient short-circuit power. This results in the increase of the short-circuit ratio (SCR) at transmission system bus-bars serving as points of interconnection (POI) to renewable generation. Evaluation of the required capacity and grid-location of the synchronous condensers......, isinherently a mixed integer non-linear optimization problem, which could not be done on manual basis considering each type of machine and all bus-bars. This study therefore proposes a method of optimal allocation of synchronous condensers in a hypothetic future scenario of a transmission system fed...

  12. Allocation of synchronous condensers for restoration of system short-circuit power

    DEFF Research Database (Denmark)

    Marrazi, Emanuel; Yang, Guangya; Weinreich-Jensen, Peter

    2017-01-01

    Modern power systems, employing an increasing number of converter-based renewable energy sources (RES) and decreasing the usage of conventional power plants, are leading to lower levels of short-circuit power and rotational inertia. A solution to this is the employment of synchronous condensers...... in the grid, in order to provide sufficient short-circuit power. This results in the increase of the short-circuit ratio (SCR) at transmission system bus-bars serving as points of interconnection (POI) to renewable generation. Evaluation of the required capacity and grid-location of the synchronous condensers...... by renewable generation. Total cost of synchronous condenser installations in the system is minimized and the SCRs at the POIs of central renewable power plants are strengthened. The method has potential for application on larger grids, aiding grid-integration of RES....

  13. A Behavior-Based Circuit Model of How Outcome Expectations Organize Learned Behavior in Larval "Drosophila"

    Science.gov (United States)

    Schleyer, Michael; Saumweber, Timo; Nahrendorf, Wiebke; Fischer, Benjamin; von Alpen, Desiree; Pauls, Dennis; Thum, Andreas; Gerber, Bertram

    2011-01-01

    Drosophila larvae combine a numerically simple brain, a correspondingly moderate behavioral complexity, and the availability of a rich toolbox for transgenic manipulation. This makes them attractive as a study case when trying to achieve a circuit-level understanding of behavior organization. From a series of behavioral experiments, we suggest a…

  14. Short-Circuit Current Analysis for DFIG Wind Farm Considering the Action of a Crowbar

    OpenAIRE

    Yan Hong Yuan; Feng Wu

    2018-01-01

    With the increasing capacity of wind farms integrated into the power grid, the short-circuit current analysis for wind farms becomes more and more important. Since the wind turbine is usually integrated into the power grid via power electronic devices, the “crowbar” is installed in the wind turbine to protect the power electronic devices and to improve the fault ride through capability. The impact of the crowbar has to be considered during the short-circuit current analysis for the wind farm....

  15. Influence of an inner short-circuit on the behaviour of the superconducting magnet

    International Nuclear Information System (INIS)

    Zizek, F.

    1984-01-01

    On exciting one of the superconducting quadrupole magnets, voltage pulses were observed on the winding outlets. Over a certain current level the pulses disappeared and a quench of the magnet was registered. A subsequent analysis proved that phenomenon was caused by short-circuiting of the turns inside one of the quadrupole coils. The voltage pulses were caused by repeated quenches of the short-circuited part of the winding. The above effect did not appear until a certain rate of rise of the current was attained

  16. Influence of an inner short-circuit on the behaviour of the superconducting magnet

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F. (Skoda k.p., Plzen (Czechoslovakia))

    1984-01-01

    On exciting one of the superconducting quadrupole magnets, voltage pulses were observed on the winding outlets. Over a certain current level the pulses disappeared and a quench of the magnet was registered. A subsequent analysis proved that phenomenon was caused by short-circuiting of the turns inside one of the quadrupole coils. The voltage pulses were caused by repeated quenches of the short-circuited part of the winding. The above effect did not appear until a certain rate of rise of the current was attained.

  17. Defects influence on short circuit current density in p-i-n silicon solar cell

    International Nuclear Information System (INIS)

    Wagah F Mohamad; Alhan M Mustafa

    2006-01-01

    The admittance analysis method has been used to calculate the collection efficiency and the short circuit current density in a-Si:H p-i-n solar cell, as a function of the thickness of i-layer. Its is evident that the results of the short circuit current can be used to determine the optimal thickness of the i-layer of a cell, and it will be more accurate in comparison with the previous studies using a constant generation rate or an empirical exponential function for the generation of charge carriers throughout the i-layer

  18. Forces and stresses in cryoturbogenerator rotor in presence of short circuit

    International Nuclear Information System (INIS)

    Kovarskii, M.E.; Rubinraut, A.M.; Tsyrlin, A.L.

    1981-01-01

    A method is presented for determining the electrodynamic forces, mechanical stresses, and strains in the shells of a cryogenic-turbogenerator cryostat in the presence of an abrupt short circuit. The physical pattern of occurrence of forces in a cryostat shell is considered for capacitive, inductive, and active armature-current cases. It is shown that in addition to the radial component, there is a tangential component of the electrodynamic forces, with the interaction of the two components governing the strength in the presence of short circuits. Results are reported for mechanical-strength calculations, based on the proposed method, for a 200 kw cryogenic turbogenerator

  19. Voltage Recovery of Grid-Connected Wind Turbines with DFIG After a Short-Circuit Fault

    DEFF Research Database (Denmark)

    Sun, Tao; Chen, Zhe; Blaabjerg, Frede

    2004-01-01

    The fast development of wind power generation brings new requirements for wind turbine integration to the network. After clearance of an external short-circuit fault, the voltage at the wind turbine terminal should be re-established with minimized power losses. This paper concentrates on voltage......-establish the wind turbine terminal voltage after the clearance of an external short-circuit fault, and the restore the normal operation of the variable speed wind turbine with DFIG, which has been demonstrated by simulation results....

  20. Unstable behaviour of normally-off GaN E-HEMT under short-circuit

    Science.gov (United States)

    Martínez, P. J.; Maset, E.; Sanchis-Kilders, E.; Esteve, V.; Jordán, J.; Bta Ejea, J.; Ferreres, A.

    2018-04-01

    The short-circuit capability of power switching devices plays an important role in fault detection and the protection of power circuits. In this work, an experimental study on the short-circuit (SC) capability of commercial 600 V Gallium Nitride enhancement-mode high-electron-mobility transistors (E-HEMT) is presented. A different failure mechanism has been identified for commercial p-doped GaN gate (p-GaN) HEMT and metal-insulator-semiconductor (MIS) HEMT. In addition to the well known thermal breakdown, a premature breakdown is shown on both GaN HEMTs, triggered by hot electron trapping at the surface, which demonstrates that current commercial GaN HEMTs has requirements for improving their SC ruggedness.

  1. Verification of the short-circuit current making capability of high-voltage switching devices

    NARCIS (Netherlands)

    Smeets, R.P.P.; Linden, van der W.A.

    2001-01-01

    Switching-in of short-circuit current leads to pre-arcing in the switching device. Pre-arcing affects the ability of switchgear to close and latch. In three-phase systems, making is associated with transient voltage phenomena that may have a significant impact on the duration of the pre-arcing

  2. Development of internal/external short circuit protection for lithium D cells

    Science.gov (United States)

    Mcdonald, Robert C.; Bragg, Bobby J.

    1992-01-01

    A brief discussion of short circuit protection for lithium D cells is given in viewgraph format. The following topics are presented: (1) historical need; (2) program objectives; (3) composite thermal switch (CTS) development; (4) laboratory cells with CTS; and (5) the incorporation of CTS into lithium D cells.

  3. Short Circuits of a 10 MW High Temperature Superconducting Wind Turbine Generator

    NARCIS (Netherlands)

    Song, X.; Polinder, H.; Liu, D.; Mijatovic, Nenad; Holbøll, Joachim; Jensen, Bogi Bech

    Direct drive high temperature superconducting (HTS) wind turbine generators have been proposed to tackle challenges for ever increasing wind turbine ratings. Due to smaller reactances in HTS generators, higher fault currents and larger transient torques could occur if sudden short circuits happen at

  4. Electro-thermal modeling of high power IGBT module short-circuits with experimental validation

    DEFF Research Database (Denmark)

    Wu, Rui; Iannuzzo, Francesco; Wang, Huai

    2015-01-01

    A novel Insulated Gate Bipolar Transistor (IGBT) electro-thermal modeling approach involving PSpice and ANSYS/Icepak with both high accuracy and simulation speed has been presented to study short-circuit of a 1.7 kV/1 kA commercial IGBT module. The approach successfully predicts the current...

  5. Network model and short circuit program for the Kennedy Space Center electric power distribution system

    Science.gov (United States)

    1976-01-01

    Assumptions made and techniques used in modeling the power network to the 480 volt level are discussed. Basic computational techniques used in the short circuit program are described along with a flow diagram of the program and operational procedures. Procedures for incorporating network changes are included in this user's manual.

  6. Short-Circuit Robustness Assessment in Power Electronic Modules for Megawatt Applications

    DEFF Research Database (Denmark)

    Iannuzzo, Francesco

    2016-01-01

    In this paper, threats and opportunities in testing of megawatt power electronic modules under short circuit are presented and discussed, together with the introduction of some basic principles of non-destructive testing, a key technique to allow post-failure analysis. The non-destructive testing...

  7. L2 Reading Ability: Further Insight into the Short-Circuit Hypothesis.

    Science.gov (United States)

    Taillefer, Gail F.

    1996-01-01

    Discusses the notion of a language proficiency threshold that short circuits the transfer of reading ability from the native language (L1) to a second language (L2). This study, in which cognitive complexity of tasks and students' L2 proficiency levels vary, focuses on university students in France reading preprofessional English texts. (39…

  8. Current-zero measurements of vacuum circuit breakers interrupting short-line faults

    NARCIS (Netherlands)

    Smeets, R.P.P.; Linden, van der W.A.

    2003-01-01

    Current zero measurements are performed during short-line fault interruption tests of vacuum circuit breakers. This switching cycle is characterized by a very steep transient recovery voltage. High-resolution measurements of near current-zero arc current and voltage were carried out. Various

  9. Integrated Power Flow and Short Circuit Calculation Method for Distribution Network with Inverter Based Distributed Generation

    Directory of Open Access Journals (Sweden)

    Shan Yang

    2016-01-01

    Full Text Available Power flow calculation and short circuit calculation are the basis of theoretical research for distribution network with inverter based distributed generation. The similarity of equivalent model for inverter based distributed generation during normal and fault conditions of distribution network and the differences between power flow and short circuit calculation are analyzed in this paper. Then an integrated power flow and short circuit calculation method for distribution network with inverter based distributed generation is proposed. The proposed method let the inverter based distributed generation be equivalent to Iθ bus, which makes it suitable to calculate the power flow of distribution network with a current limited inverter based distributed generation. And the low voltage ride through capability of inverter based distributed generation can be considered as well in this paper. Finally, some tests of power flow and short circuit current calculation are performed on a 33-bus distribution network. The calculated results from the proposed method in this paper are contrasted with those by the traditional method and the simulation method, whose results have verified the effectiveness of the integrated method suggested in this paper.

  10. Results of experimental research of the modes of short circuit in a traction network

    Directory of Open Access Journals (Sweden)

    P.Ye. Mykhalichenko

    2012-08-01

    Full Text Available In the article the results, namely oscillograms of the transitional feeder electric values obtained by the experimental tests of the short circuit modes in case of setting off different types of substation fast-acting switches are presented. The experiments were conducted on the operating electrified track sections of the Prydniprovs’ka Railway.

  11. EQUATIONS OF ELECTRIC MOTOR POWER SUPPLY UNIT DISSYMMETRY UNDER PHASE SHORT-CIRCUIT FAULT

    Directory of Open Access Journals (Sweden)

    V.Y. Tchaban

    2013-04-01

    Full Text Available In the paper, a formula is introduced for calculating electric motor supply unit voltage under feeding by a common transformer in the condition of a phase short-circuit in one of the motors. The formula is used in every time step of electromechanical state equations integration.

  12. The influence of gamma irradiation on short-circuit current in CuGaSe2

    International Nuclear Information System (INIS)

    Gasimoglu, I.; Mamedova, I.A.; Bagirov, A.G.

    2005-01-01

    Full text : The influence of gamma irradiation on a short-circuit current at 77 K was investigated. The appeared strip with a maximum at 1,61 ///// after irradiation in spectral dependence connected with p-type radiating defects [ru

  13. Conditions of the existence of 'short circuit' effect for plasma in a conducting cylinder

    International Nuclear Information System (INIS)

    Zhilinskij, A.P.; Kuteev, B.V.

    1975-01-01

    It has been experimentally established that in a cylindrical container with conducting side and end walls, the phenomenon of short circuit (the Symon effect) is not always realized. The short circuiting of plane end and of side surfaces causes an acceleration of a plasma decay only during the initial stage in a comparatively short time. Characteristic lifetimes during the late stage remain unchanged in this case. In conditions of a stable plasma they correspond to classical values of the plasma decay constant at the ambipolar diffusion of charged particles along and across force lines of a magnetic field. A fundamental change in the nature of the diffusion and a decrease of the plasma lifetime almost by two orders are realized in an instrument in which an end conducting wall for plasma in created with a short cylinder at the end of a solenoid in a sharply nonuniform magnetic field. The data obtained testify to the fact that the short circuit effect takes place in conditions when on boundaries of plasma the possibility of simultaneous flowing of unipolar electron flows along and of ion flows across a magnetic field is assured. The results of the experiments are compared with a theory

  14. NREL/NASA Internal Short-Circuit Instigator in Lithium Ion Cells

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, Matthew; Long, Dirk; Pesaran, Ahmad; Darcy, Eric; Shoesmith, Mark; McCarthy, Ben

    2015-10-11

    Lithium-ion cells provide the highest specific energy (>280 Wh/kg) and energy density (>600 Wh/L) rechargeable battery building block to date with the longest life. Electrode/electrolyte thermal instability and flammability of the electrolyte of Li-ion cells make them prone to catastrophic thermal runaway under some rare internal short circuit conditions. Despite extensive QC/QA, standardized industry safety testing, and over 18 years of manufacturing experience, major recalls have taken place and incidents still occur. Many safety incidents that take place in the field originate due to an internal short that was not detectable or predictable at the point of manufacture. The Internal Short-Circuit Instigator can be used to study types of separators, non-flammable electrolytes, electrolyte additives, fusible tabs, propagation studies, and gas generation within a cell.

  15. Load Flow and Short Circuit Analysis of the Class III Power System of HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. K.; Jung, H. S

    2005-12-15

    The planning, design, and operation of electric power system require engineering studies to assist in the evaluation of the system performance, reliability, safety and economics. The Class III power of HANARO supplies power for not only HANARO but also RIPF and IMEF. The starting current of most ac motors is five to ten times normal full load current. The loads of the Class III power are connected in consecutive orders at an interval for 10 seconds to avoid excessive voltage drop. This technical report deals with the load flow study and motor starting study for the Class III power of HANARO using ETAP(Electrical Transient Analyzer Program) to verify the capacity of the diesel generator. Short-circuit studies are done to determine the magnitude of the prospective currents flowing throughout the power system at various time intervals after a fault occurs. Short-circuit studies can be performed at the planning stage in order to help finalize the system layout, determine voltage levels, and size cables, transformers, and conductors. From this study, we verify the short circuit current capacity of air circuit breaker(ACB) and automatic transfer switch(ATS) of the Class III power.

  16. The effect of recombination under short-circuit conditions on the determination of charge transport properties in nanostructured photoelectrodes.

    Science.gov (United States)

    Villanueva-Cab, J; Anta, J A; Oskam, G

    2016-01-28

    We report on the commonly unaccounted for process of recombination under short-circuit conditions in nanostructured photoelectrodes with special attention to the charge collection efficiency. It is observed that when recombination under short circuit conditions is significant, small perturbation methods overestimate the charge-collection efficiency, which is related to the inaccurate determination of the electron diffusion coefficient and diffusion length.

  17. Approaching Repetitive Short Circuit Tests on MW-Scale Power Modules by means of an Automatic Testing Setup

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Wang, Huai; Iannuzzo, Francesco

    2016-01-01

    An automatic testing system to perform repetitive short-circuit tests on megawatt-scale IGBT power modules is pre-sented and described in this paper, pointing out the advantages and features of such testing approach. The developed system is based on a non-destructive short-circuit tester, which has...

  18. Several problems of algorithmization in integrated computation programs on third generation computers for short circuit currents in complex power networks

    Energy Technology Data Exchange (ETDEWEB)

    Krylov, V.A.; Pisarenko, V.P.

    1982-01-01

    Methods of modeling complex power networks with short circuits in the networks are described. The methods are implemented in integrated computation programs for short circuit currents and equivalents in electrical networks with a large number of branch points (up to 1000) on a computer with a limited on line memory capacity (M equals 4030 for the computer).

  19. Diagnosis of Soft Spot Short Defects in Analog Circuits Considering the Thermal Behaviour of the Chip

    Directory of Open Access Journals (Sweden)

    Tadeusiewicz Michał

    2016-06-01

    Full Text Available The paper deals with fault diagnosis of nonlinear analogue integrated circuits. Soft spot short defects are analysed taking into account variations of the circuit parameters due to physical imperfections as well as self-heating of the chip. A method enabling to detect, locate and estimate the value of a spot defect has been developed. For this purpose an appropriate objective function was minimized using an optimization procedure based on the Fibonacci method. The proposed approach exploits DC measurements in the test phase, performed at a limited number of accessible points. For illustration three numerical examples are given.

  20. The stochastic behavior of a molecular switching circuit with feedback

    Directory of Open Access Journals (Sweden)

    Smith Eric

    2007-05-01

    Full Text Available Abstract Background Using a statistical physics approach, we study the stochastic switching behavior of a model circuit of multisite phosphorylation and dephosphorylation with feedback. The circuit consists of a kinase and phosphatase acting on multiple sites of a substrate that, contingent on its modification state, catalyzes its own phosphorylation and, in a symmetric scenario, dephosphorylation. The symmetric case is viewed as a cartoon of conflicting feedback that could result from antagonistic pathways impinging on the state of a shared component. Results Multisite phosphorylation is sufficient for bistable behavior under feedback even when catalysis is linear in substrate concentration, which is the case we consider. We compute the phase diagram, fluctuation spectrum and large-deviation properties related to switch memory within a statistical mechanics framework. Bistability occurs as either a first-order or second-order non-equilibrium phase transition, depending on the network symmetries and the ratio of phosphatase to kinase numbers. In the second-order case, the circuit never leaves the bistable regime upon increasing the number of substrate molecules at constant kinase to phosphatase ratio. Conclusion The number of substrate molecules is a key parameter controlling both the onset of the bistable regime, fluctuation intensity, and the residence time in a switched state. The relevance of the concept of memory depends on the degree of switch symmetry, as memory presupposes information to be remembered, which is highest for equal residence times in the switched states. Reviewers This article was reviewed by Artem Novozhilov (nominated by Eugene Koonin, Sergei Maslov, and Ned Wingreen.

  1. Circadian remodeling of neuronal circuits involved in rhythmic behavior.

    Directory of Open Access Journals (Sweden)

    María Paz Fernández

    2008-03-01

    Full Text Available Clock output pathways are central to convey timing information from the circadian clock to a diversity of physiological systems, ranging from cell-autonomous processes to behavior. While the molecular mechanisms that generate and sustain rhythmicity at the cellular level are well understood, it is unclear how this information is further structured to control specific behavioral outputs. Rhythmic release of pigment dispersing factor (PDF has been proposed to propagate the time of day information from core pacemaker cells to downstream targets underlying rhythmic locomotor activity. Indeed, such circadian changes in PDF intensity represent the only known mechanism through which the PDF circuit could communicate with its output. Here we describe a novel circadian phenomenon involving extensive remodeling in the axonal terminals of the PDF circuit, which display higher complexity during the day and significantly lower complexity at nighttime, both under daily cycles and constant conditions. In support to its circadian nature, cycling is lost in bona fide clockless mutants. We propose this clock-controlled structural plasticity as a candidate mechanism contributing to the transmission of the information downstream of pacemaker cells.

  2. Measurements of impedances for determinating the minimum short-circuit current in main systems 500 V of underground mining establishments

    Energy Technology Data Exchange (ETDEWEB)

    Rittinghaus, D

    1981-09-01

    The complex short-circuit impedances of energized low-voltage main systems were measured with a double-bridge in underground mining operation. The magnitude of the short-circuit currents depends on these impedances. Customary calculations of such currents depend on empirical approximations. To verify the accuracy of these approximations, the measured impedances of 61 nodes in three different main systems were compared with the results of the calculations. The comparison made between the short-circuit currents determined by measurable quantities and the values calculated according to VDE 0118 shows that the stipulated coefficients for calculating the minimum short-circuit currents lie very far on the safe side. An amendment for calculating the short-circuit in accordance with VDE 0118 is therefore suggested.

  3. Simultaneous improvement in short circuit current, open circuit voltage, and fill factor of polymer solar cells through ternary strategy.

    Science.gov (United States)

    An, Qiaoshi; Zhang, Fujun; Li, Lingliang; Wang, Jian; Sun, Qianqian; Zhang, Jian; Tang, Weihua; Deng, Zhenbo

    2015-02-18

    We present a smart strategy to simultaneously increase the short circuit current (Jsc), the open circuit voltage (Voc), and the fill factor (FF) of polymer solar cells (PSCs). A two-dimensional conjugated small molecule photovoltaic material (SMPV1), as the second electron donor, was doped into the blend system of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C71-butyric acid methyl (PC71BM) to form ternary PSCs. The ternary PSCs with 5 wt % SMPV1 doping ratio in donors achieve 4.06% champion power conversion efficiency (PCE), corresponding to about 21.2% enhancement compared with the 3.35% PCE of P3HT:PC71BM-based PSCs. The underlying mechanism on performance improvement of ternary PSCs can be summarized as (i) harvesting more photons in the longer wavelength region to increase Jsc; (ii) obtaining the lower mixed highest occupied molecular orbital (HOMO) energy level by incorporating SMPV1 to increase Voc; (iii) forming the better charge carrier transport channels through the cascade energy level structure and optimizing phase separation of donor/acceptor materials to increase Jsc and FF.

  4. Model-based evaluation of the short-circuited tripolar cuff configuration.

    Science.gov (United States)

    Andreasen, Lotte N S; Struijk, Johannes J

    2006-05-01

    Recordings of neural information for use as feedback in functional electrical stimulation are often contaminated with interfering signals from muscles and from stimulus pulses. The cuff electrode used for the neural recording can be optimized to improve the S/I ratio. In this work, we evaluate a model of both the nerve signal and the interfering signals recorded by a cuff, and subsequently use this model to study the signal to interference ratio of different cuff designs and to evaluate a recently introduced short-circuited tripolar cuff configuration. The results of the model showed good agreement with results from measurements in rabbits and confirmed the superior performance of the short-circuited tripolar configuration as compared with the traditionally used tripolar configuration.

  5. Asymmetrical short circuits in medium-voltage networks with grounded neutral through resistance

    Energy Technology Data Exchange (ETDEWEB)

    Tanasescu, M.; Maries, H.

    1981-01-01

    This article introduces the concepts of ''damage to ground'' and ''current to ground indicator'', which characterize the efficiency of the operating mode of the neutral. The values of these two indicators are assigned by directive (eletric power plan design instruction PE109/1980) and must be provided when selecting the parameters of compensating devices installed in the neutral. Possible aymmetrical short circuits in medium-voltage networks with neutral ground are examined. Formulas are derived for determining the short-circuiting currents and undamaged phase voltages in order to determine the damage to ground indicator and ground current indicator; an example of a calculation is given.

  6. Influence of wavelength on transient short-circuit current in polycrystalline silicon solar cells

    International Nuclear Information System (INIS)

    Ba, B.; Kane, M.

    1993-10-01

    The influence of the wavelength of a monochromatic illumination on transient short-circuit current in an n/p polycrystalline silicon part solar cell junction is investigated. A wavelength dependence in the initial part of the current decay is observed in the case of cells with moderate grain boundary effects. This influence is attenuated in polycrystalline cells with strong grain boundary activity. (author). 10 refs, 6 figs

  7. On Demand Internal Short Circuit Device Enables Verification of Safer, Higher Performing Battery Designs

    Energy Technology Data Exchange (ETDEWEB)

    Darcy, Eric; Keyser, Matthew

    2017-05-15

    The Internal Short Circuit (ISC) device enables critical battery safety verification. With the aluminum interstitial heat sink between the cells, normal trigger cells cannot be driven into thermal runaway without excessive temperature bias of adjacent cells. With an implantable, on-demand ISC device, thermal runaway tests show that the conductive heat sinks protected adjacent cells from propagation. High heat dissipation and structural support of Al heat sinks show high promise for safer, higher performing batteries.

  8. Increased short circuit current in an azafullerene-based organic solar cell.

    Science.gov (United States)

    Cambarau, Werther; Fritze, Urs F; Viterisi, Aurélien; Palomares, Emilio; von Delius, Max

    2015-01-21

    We report the synthesis of a solution-processable, dodecyloxyphenyl-substituted azafullerene monoadduct (DPC59N) and its application as electron acceptor in bulk heterojunction organic solar cells (BHJ-OSCs). Due to its relatively strong absorption of visible light, DPC59N outperforms PC60BM in respect to short circuit current (JSC) and external quantum efficiency (EQE) in blends with donor P3HT.

  9. An Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

    Science.gov (United States)

    Courey, Karim; Wright, Clara; Asfour, Shihab; Onar, Arzu; Bayliss, Jon; Ludwig, Larry

    2009-01-01

    In this experiment, an empirical model to quantify the probability of occurrence of an electrical short circuit from tin whiskers as a function of voltage was developed. This empirical model can be used to improve existing risk simulation models. FIB and TEM images of a tin whisker confirm the rare polycrystalline structure on one of the three whiskers studied. FIB cross-section of the card guides verified that the tin finish was bright tin.

  10. An Investigation of Short Circuits in All-solution Processed and All-organic Solar Cells

    OpenAIRE

    Johansson, Jim

    2015-01-01

    Organic solar cells have shown great promise of becoming a cheaper alternative to inorganic solar cells. Additionally, they can also be made semitransparent. To avoid using expensive indium tin oxide electrodes in organic solar cells the electrodes can be made from conductive polymer, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). However, these so-called PEDOT-PEDOT solar cells are prone to short-circuiting. The work behind this thesis thus aimed to find the cause of the...

  11. Modeling and Fault Diagnosis of Interturn Short Circuit for Five-Phase Permanent Magnet Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Jian-wei Yang

    2015-01-01

    Full Text Available Taking advantage of the high reliability, multiphase permanent magnet synchronous motors (PMSMs, such as five-phase PMSM and six-phase PMSM, are widely used in fault-tolerant control applications. And one of the important fault-tolerant control problems is fault diagnosis. In most existing literatures, the fault diagnosis problem focuses on the three-phase PMSM. In this paper, compared to the most existing fault diagnosis approaches, a fault diagnosis method for Interturn short circuit (ITSC fault of five-phase PMSM based on the trust region algorithm is presented. This paper has two contributions. (1 Analyzing the physical parameters of the motor, such as resistances and inductances, a novel mathematic model for ITSC fault of five-phase PMSM is established. (2 Introducing an object function related to the Interturn short circuit ratio, the fault parameters identification problem is reformulated as the extreme seeking problem. A trust region algorithm based parameter estimation method is proposed for tracking the actual Interturn short circuit ratio. The simulation and experimental results have validated the effectiveness of the proposed parameter estimation method.

  12. Investigation on a short circuit of large-area OLED lighting panels

    International Nuclear Information System (INIS)

    Park, J W; Kim, T W; Park, J B

    2013-01-01

    A short circuit often arises from large-area organic light-emitting device (OLED) lighting panels due to particles (i.e. dust, organic or metal debris) or the spike-like surface of the indium–tin–oxide (ITO) anode. On the emergence of a short circuit, an instant current crowding occurs, thereby reducing substantially the resistance of the panels and causing a failure of a dimming control. In this paper, we investigate the effect of the surface morphology of ITO on the resistance and dimmability of the panels. We have demonstrated that the peak-to-valley roughness of ITO should be much less than 20 nm or the resistance of the panels should be much higher than 1 MΩ in order to avoid an unwanted short-circuit phenomenon and thus achieve the high-yield fabrication of OLED lighting panels. It is also addressed that much care is taken to ensure a dimming control of OLED lighting panels with a larger active area because the resistance of those panels varies depending more sensitively on the surface roughness of ITO. (paper)

  13. A Nanostructured Composites Thermal Switch Controls Internal and External Short Circuit in Lithium Ion Batteries

    Science.gov (United States)

    McDonald, Robert C.; VanBlarcom, Shelly L.; Kwasnik, Katherine E.

    2013-01-01

    A document discusses a thin layer of composite material, made from nano scale particles of nickel and Teflon, placed within a battery cell as a layer within the anode and/or the cathode. There it conducts electrons at room temperature, then switches to an insulator at an elevated temperature to prevent thermal runaway caused by internal short circuits. The material layer controls excess currents from metal-to-metal or metal-to-carbon shorts that might result from cell crush or a manufacturing defect

  14. Development of processing procedures for advanced silicon solar cells. [antireflection coatings and short circuit currents

    Science.gov (United States)

    Scott-Monck, J. A.; Stella, P. M.; Avery, J. E.

    1975-01-01

    Ten ohm-cm silicon solar cells, 0.2 mm thick, were produced with short circuit current efficiencies up to thirteen percent and using a combination of recent technical advances. The cells were fabricated in conventional and wraparound contact configurations. Improvement in cell collection efficiency from both the short and long wavelengths region of the solar spectrum was obtained by coupling a shallow junction and an optically transparent antireflection coating with back surface field technology. Both boron diffusion and aluminum alloying techniques were evaluated for forming back surface field cells. The latter method is less complicated and is compatible with wraparound cell processing.

  15. Errors in short circuit measurements due to spectral mismatch between sunlight and solar simulators

    Science.gov (United States)

    Curtis, H. B.

    1976-01-01

    Errors in short circuit current measurement were calculated for a variety of spectral mismatch conditions. The differences in spectral irradiance between terrestrial sunlight and three types of solar simulator were studied, as well as the differences in spectral response between three types of reference solar cells and various test cells. The simulators considered were a short arc xenon lamp AMO sunlight simulator, an ordinary quartz halogen lamp, and an ELH-type quartz halogen lamp. Three types of solar cells studied were a silicon cell, a cadmium sulfide cell and a gallium arsenide cell.

  16. An Investigation of the Electrical Short Circuit Characteristics of Tin Whiskers

    Science.gov (United States)

    Courey, Karim J.

    2008-01-01

    Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has a currently unknown probability associated with it. Due to contact resistance electrical shorts may not occur at lower voltage levels. In this experiment, we study the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From this data we can estimate the probability of an electrical short, as a function of voltage, given that a free tin whisker has bridged two adjacent exposed electrical conductors. Also, three tin whiskers grown from the same Space Shuttle Orbiter card guide used in the aforementioned experiment were cross-sectioned and studied using a focused ion beam (FIB). The rare polycrystalline structure seen in the FIB cross section was confirmed using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size to determine that the tin plating on the card guides had a bright finish.

  17. Research Tool to Evaluate the Safety Response of Lithium Batteries to an Internal Short Circuit

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, Matthew; Darcy, Eric; Pesaran, Ahmad

    2016-06-19

    Li-ion cells provide the highest specific energy and energy density rechargeable battery with the longest life. Many safety incidents that take place in the field originate due to an internal short that was not detectable or predictable at the point of manufacture. NREL's internal short circuit (ISC) device is capable of simulating shorts and produces consistent and reproducible results. The cell behaves normally until the ISC device is activated wherein a latent defect (i.e., built into the cell during manufacturing) gradually moves into position to create an internal short while the battery is in use, providing relevant data to verify abuse models. The ISC device is an effective tool for studying the safety features of parts of Li-ion batteries.

  18. Feasibility study of superconducting power cables for DC electric railway feeding systems in view of thermal condition at short circuit accident

    Science.gov (United States)

    Kumagai, Daisuke; Ohsaki, Hiroyuki; Tomita, Masaru

    2016-12-01

    A superconducting power cable has merits of a high power transmission capacity, transmission losses reduction, a compactness, etc., therefore, we have been studying the feasibility of applying superconducting power cables to DC electric railway feeding systems. However, a superconducting power cable is required to be cooled down and kept at a very low temperature, so it is important to reveal its thermal and cooling characteristics. In this study, electric circuit analysis models of the system and thermal analysis models of superconducting cables were constructed and the system behaviors were simulated. We analyzed the heat generation by a short circuit accident and transient temperature distribution of the cable to estimate the value of temperature rise and the time required from the accident. From these results, we discussed a feasibility of superconducting cables for DC electric railway feeding systems. The results showed that the short circuit accident had little impact on the thermal condition of a superconducting cable in the installed system.

  19. Comportamiento del tiempo de duración, la frecuencia de los cortocircuitos y la conductividad eléctrica durante el reencendido del arco en la soldadura SMAW (AC con electrodos E6013 Behavior of short-circuit frequency and duration time and electrical conductivity on arc turn- on during SMAW (AC with E6013 electrodes

    Directory of Open Access Journals (Sweden)

    Alejandro García Rodríguez

    2009-03-01

    Full Text Available El presente trabajo tiene como objetivo la evaluación del comportamiento del tiempo de duración, la frecuencia de los cortocircuitos y la conductividad durante el reencendido del arco en el proceso de soldadura SMAW (Shielded Metal Arc Welding, con corriente alterna y electrodos E6013. El análisis estadístico no-paramétrico garantiza un procesamiento robusto de los datos, atenuando la influencia de valores atípicos y errores derivados del empleo de aproximaciones a distribuciones continuas conocidas. La mediana y la mediana de la desviación absoluta (MAD, respecto a la mediana de los datos, constituyen los estimadores de localización y dispersión utilizados, respectivamente. El electrodo, en el régimen de 160 A, presenta una mayor estabilidad, en el aporte metálico, dada por el menor valor del MAD promedio del período de cortocircuito (39,36 ms y de la duración del cortocircuito (1,43 ms, reafirmada con la presencia de una mayor conductividad eléctrica durante el reencendido (1766,17x10-3 S·s-1.The objective of this work is the valuation of the behavior of short-circuits frequency and duration time and electrical conductivity on arc reigniting in SMAW (Shielded Metal Arc Welding process with alternate current and E6013 electrodes. The non parametric statistic analysis realize a robust data processing, minimizing the outliers influence and mistakes derivates about employ of approximations to well know continues distributions. The median and the median absolute deviation (MAD respect to median of the data are the localization and dispersion estimators used, respectively. The electrode at 160 A present a better stability on metal transference supported on the most little value of MAD for the period of transference (39,36 ms, and the MAD of the short-circuit duration (1,43 ms, according with the presence of a major electric conductivity during the arc reigniting (1766,17x10-3 S·s-1.

  20. Short-Circuit Characterization of 10 kV 10A 4H-SiC MOSFET

    DEFF Research Database (Denmark)

    Eni, Emanuel-Petre; Beczkowski, Szymon; Munk-Nielsen, Stig

    2016-01-01

    The short-circuit capability of a power device is highly relevant for converter design and fault protection. In this paper a 10kV 10A 4H-SiC MOSFET is characterized and its short circuit withstand capability is studied and analyzed at 6 kV DC-link voltage. The test setup for this study is also...... introduced as its design, especially the inductance in the switching loop, can affect the experimental results. The study aims to present insights specific to the device which are different from that of silicon (Si) based devices. During the short-circuit operation, MOSFET saturation current, ID...

  1. Controlled Conjugated Backbone Twisting for an Increased Open-Circuit Voltage while Having a High Short-Circuit Current in Poly(hexylthiophene) Derivatives

    KAUST Repository

    Ko, Sangwon

    2012-03-21

    Conjugated polymers with nearly planar backbones have been the most commonly investigated materials for organic-based electronic devices. More twisted polymer backbones have been shown to achieve larger open-circuit voltages in solar cells, though with decreased short-circuit current densities. We systematically impose twists within a family of poly(hexylthiophene)s and examine their influence on the performance of polymer:fullerene bulk heterojunction (BHJ) solar cells. A simple chemical modification concerning the number and placement of alkyl side chains along the conjugated backbone is used to control the degree of backbone twisting. Density functional theory calculations were carried out on a series of oligothiophene structures to provide insights on how the sterically induced twisting influences the geometric, electronic, and optical properties. Grazing incidence X-ray scattering measurements were performed to investigate how the thin-film packing structure was affected. The open-circuit voltage and charge-transfer state energy of the polymer:fullerene BHJ solar cells increased substantially with the degree of twist induced within the conjugated backbone-due to an increase in the polymer ionization potential-while the short-circuit current decreased as a result of a larger optical gap and lower hole mobility. A controlled, moderate degree of twist along the poly(3,4-dihexyl-2,2′:5′,2′′- terthiophene) (PDHTT) conjugated backbone led to a 19% enhancement in the open-circuit voltage (0.735 V) vs poly(3-hexylthiophene)-based devices, while similar short-circuit current densities, fill factors, and hole-carrier mobilities were maintained. These factors resulted in a power conversion efficiency of 4.2% for a PDHTT:[6,6]-phenyl-C 71-butyric acid methyl ester (PC 71BM) blend solar cell without thermal annealing. This simple approach reveals a molecular design avenue to increase open-circuit voltage while retaining the short-circuit current. © 2012 American

  2. Controlled conjugated backbone twisting for an increased open-circuit voltage while having a high short-circuit current in poly(hexylthiophene) derivatives.

    Science.gov (United States)

    Ko, Sangwon; Hoke, Eric T; Pandey, Laxman; Hong, Sanghyun; Mondal, Rajib; Risko, Chad; Yi, Yuanping; Noriega, Rodrigo; McGehee, Michael D; Brédas, Jean-Luc; Salleo, Alberto; Bao, Zhenan

    2012-03-21

    Conjugated polymers with nearly planar backbones have been the most commonly investigated materials for organic-based electronic devices. More twisted polymer backbones have been shown to achieve larger open-circuit voltages in solar cells, though with decreased short-circuit current densities. We systematically impose twists within a family of poly(hexylthiophene)s and examine their influence on the performance of polymer:fullerene bulk heterojunction (BHJ) solar cells. A simple chemical modification concerning the number and placement of alkyl side chains along the conjugated backbone is used to control the degree of backbone twisting. Density functional theory calculations were carried out on a series of oligothiophene structures to provide insights on how the sterically induced twisting influences the geometric, electronic, and optical properties. Grazing incidence X-ray scattering measurements were performed to investigate how the thin-film packing structure was affected. The open-circuit voltage and charge-transfer state energy of the polymer:fullerene BHJ solar cells increased substantially with the degree of twist induced within the conjugated backbone--due to an increase in the polymer ionization potential--while the short-circuit current decreased as a result of a larger optical gap and lower hole mobility. A controlled, moderate degree of twist along the poly(3,4-dihexyl-2,2':5',2''-terthiophene) (PDHTT) conjugated backbone led to a 19% enhancement in the open-circuit voltage (0.735 V) vs poly(3-hexylthiophene)-based devices, while similar short-circuit current densities, fill factors, and hole-carrier mobilities were maintained. These factors resulted in a power conversion efficiency of 4.2% for a PDHTT:[6,6]-phenyl-C(71)-butyric acid methyl ester (PC(71)BM) blend solar cell without thermal annealing. This simple approach reveals a molecular design avenue to increase open-circuit voltage while retaining the short-circuit current.

  3. Circuit motifs for contrast-adaptive differentiation in early sensory systems: the role of presynaptic inhibition and short-term plasticity.

    Science.gov (United States)

    Zhang, Danke; Wu, Si; Rasch, Malte J

    2015-01-01

    In natural signals, such as the luminance value across of a visual scene, abrupt changes in intensity value are often more relevant to an organism than intensity values at other positions and times. Thus to reduce redundancy, sensory systems are specialized to detect the times and amplitudes of informative abrupt changes in the input stream rather than coding the intensity values at all times. In theory, a system that responds transiently to fast changes is called a differentiator. In principle, several different neural circuit mechanisms exist that are capable of responding transiently to abrupt input changes. However, it is unclear which circuit would be best suited for early sensory systems, where the dynamic range of the natural input signals can be very wide. We here compare the properties of different simple neural circuit motifs for implementing signal differentiation. We found that a circuit motif based on presynaptic inhibition (PI) is unique in a sense that the vesicle resources in the presynaptic site can be stably maintained over a wide range of stimulus intensities, making PI a biophysically plausible mechanism to implement a differentiator with a very wide dynamical range. Moreover, by additionally considering short-term plasticity (STP), differentiation becomes contrast adaptive in the PI-circuit but not in other potential neural circuit motifs. Numerical simulations show that the behavior of the adaptive PI-circuit is consistent with experimental observations suggesting that adaptive presynaptic inhibition might be a good candidate neural mechanism to achieve differentiation in early sensory systems.

  4. Spectral analysis to detection of short circuit fault of solar photovoltaic modules in strings

    International Nuclear Information System (INIS)

    Sevilla-Camacho, P.Y.; Robles-Ocampo, J.B.; Zuñiga-Reyes, Marco A.

    2017-01-01

    This research work presents a method to detect the number of short circuit faulted solar photovoltaic modules in strings of a photovoltaic system by taking into account speed, safety, and non-use of sensors and specialized and expensive equipment. The method consists on apply the spectral analysis and statistical techniques to the alternating current output voltage of a string and detect the number of failed modules through the changes in the amplitude of the component frequency of 12 kHz. For that, the analyzed string is disconnected of the array; and a small pulsed voltage signal of frequency of 12 kHz introduces him under dark condition and controlled temperature. Previous to the analysis, the signal is analogic filtered in order to reduce the direct current signal component. The spectral analysis technique used is the Fast Fourier Transform. The obtained experimental results were validated through simulation of the alternating current equivalent circuit of a solar cell. In all experimental and simulated test, the method allowed to identify correctly the number of photovoltaic modules with short circuit in the analyzed string. (author)

  5. Avoiding short circuits from zinc metal dendrites in anode by backside-plating configuration

    Science.gov (United States)

    Higashi, Shougo; Lee, Seok Woo; Lee, Jang Soo; Takechi, Kensuke; Cui, Yi

    2016-01-01

    Portable power sources and grid-scale storage both require batteries combining high energy density and low cost. Zinc metal battery systems are attractive due to the low cost of zinc and its high charge-storage capacity. However, under repeated plating and stripping, zinc metal anodes undergo a well-known problem, zinc dendrite formation, causing internal shorting. Here we show a backside-plating configuration that enables long-term cycling of zinc metal batteries without shorting. We demonstrate 800 stable cycles of nickel–zinc batteries with good power rate (20 mA cm−2, 20 C rate for our anodes). Such a backside-plating method can be applied to not only zinc metal systems but also other metal-based electrodes suffering from internal short circuits. PMID:27263471

  6. Model-based fault diagnosis approach on external short circuit of lithium-ion battery used in electric vehicles

    International Nuclear Information System (INIS)

    Chen, Zeyu; Xiong, Rui; Tian, Jinpeng; Shang, Xiong; Lu, Jiahuan

    2016-01-01

    Highlights: • The characteristics of ESC fault of lithium-ion battery are investigated experimentally. • The proposed method to simulate the electrical behavior of ESC fault is viable. • Ten parameters in the presented fault model were optimized using a DPSO algorithm. • A two-layer model-based fault diagnosis approach for battery ESC is proposed. • The effective and robustness of the proposed algorithm has been evaluated. - Abstract: This study investigates the external short circuit (ESC) fault characteristics of lithium-ion battery experimentally. An experiment platform is established and the ESC tests are implemented on ten 18650-type lithium cells considering different state-of-charges (SOCs). Based on the experiment results, several efforts have been made. (1) The ESC process can be divided into two periods and the electrical and thermal behaviors within these two periods are analyzed. (2) A modified first-order RC model is employed to simulate the electrical behavior of the lithium cell in the ESC fault process. The model parameters are re-identified by a dynamic-neighborhood particle swarm optimization algorithm. (3) A two-layer model-based ESC fault diagnosis algorithm is proposed. The first layer conducts preliminary fault detection and the second layer gives a precise model-based diagnosis. Four new cells are short-circuited to evaluate the proposed algorithm. It shows that the ESC fault can be diagnosed within 5 s, the error between the model and measured data is less than 0.36 V. The effectiveness of the fault diagnosis algorithm is not sensitive to the precision of battery SOC. The proposed algorithm can still make the correct diagnosis even if there is 10% error in SOC estimation.

  7. Enhanced charging kinetics of porous electrodes: surface conduction as a short-circuit mechanism.

    Science.gov (United States)

    Mirzadeh, Mohammad; Gibou, Frederic; Squires, Todd M

    2014-08-29

    We use direct numerical simulations of the Poisson-Nernst-Planck equations to study the charging kinetics of porous electrodes and to evaluate the predictive capabilities of effective circuit models, both linear and nonlinear. The classic transmission line theory of de Levie holds for general electrode morphologies, but only at low applied potentials. Charging dynamics are slowed appreciably at high potentials, yet not as significantly as predicted by the nonlinear transmission line model of Biesheuvel and Bazant. We identify surface conduction as a mechanism which can effectively "short circuit" the high-resistance electrolyte in the bulk of the pores, thus accelerating the charging dynamics and boosting power densities. Notably, the boost in power density holds only for electrode morphologies with continuous conducting surfaces in the charging direction.

  8. Utilisation of symmetrical components in a communication-based protection for loop MV feeders with variable short-circuit power

    DEFF Research Database (Denmark)

    Ciontea, Catalin-Iosif; Bak, Claus Leth; Blaabjerg, Frede

    2018-01-01

    -circuit power is presented. It relies on utilisation of symmetrical components of the short-circuit currents and on communication between the protection relays. The proposed method addresses the Single Phase to Ground (SPG) faults occurring in directly grounded distribution networks, with focus on closed......Variability of the available short-circuit power also implies variation of the fault level, which can potentially cause several protection problems in the electric networks. In this paper, a novel protection method that is insensitive to the fault level changes caused by variable short......-loop Medium Voltage (MV) feeders. Case studies are presented, which demonstrate that the proposed protection scheme is capable of effectively detecting the SPG faults in closed-loop feeders with variable short-circuit power....

  9. Spatially resolved determination of the short-circuit current density of silicon solar cells via lock-in thermography

    International Nuclear Information System (INIS)

    Fertig, Fabian; Greulich, Johannes; Rein, Stefan

    2014-01-01

    We present a spatially resolved method to determine the short-circuit current density of crystalline silicon solar cells by means of lock-in thermography. The method utilizes the property of crystalline silicon solar cells that the short-circuit current does not differ significantly from the illuminated current under moderate reverse bias. Since lock-in thermography images locally dissipated power density, this information is exploited to extract values of spatially resolved current density under short-circuit conditions. In order to obtain an accurate result, one or two illuminated lock-in thermography images and one dark lock-in thermography image need to be recorded. The method can be simplified in a way that only one image is required to generate a meaningful short-circuit current density map. The proposed method is theoretically motivated, and experimentally validated for monochromatic illumination in comparison to the reference method of light-beam induced current.

  10. Correction: The effect of recombination under short-circuit conditions on the determination of charge transport properties in nanostructured photoelectrodes.

    Science.gov (United States)

    Villanueva-Cab, J; Anta, J A; Oskam, G

    2016-05-28

    Correction for 'The effect of recombination under short-circuit conditions on the determination of charge transport properties in nanostructured photoelectrodes' by J. Villanueva-Cab et al., Phys. Chem. Chem. Phys., 2016, 18, 2303-2308.

  11. Maximizing the short circuit current of organic solar cells by partial decoupling of electrical and optical properties

    Science.gov (United States)

    Qarony, Wayesh; Hossain, Mohammad I.; Jovanov, Vladislav; Knipp, Dietmar; Tsang, Yuen Hong

    2018-03-01

    The partial decoupling of electronic and optical properties of organic solar cells allows for realizing solar cells with increased short circuit current and energy conversion efficiency. The proposed device consists of an organic solar cell conformally prepared on the surface of an array of single and double textured pyramids. The device geometry allows for increasing the optical thickness of the organic solar cell, while the electrical thickness is equal to the nominal thickness of the solar cell. By increasing the optical thickness of the solar cell, the short circuit current is distinctly increased. The quantum efficiency and short circuit current are determined using finite-difference time-domain simulations of the 3D solar cell structure. The influence of different solar cell designs on the quantum efficiency and short circuit current is discussed and optimal device dimensions are proposed.

  12. Reducing the Risk of Damage to Power Transformers of 110 kV and Above Accompanying Internal Short Circuits

    Energy Technology Data Exchange (ETDEWEB)

    L’vova, M. M. [JSC “R& D Center at Federal Grid Company of the Unified Power System” (Russian Federation); L’vov, S. Yu. [Presselektro LLC (Russian Federation); Komarov, V. B. [IPCE RAS (Russian Federation); Lyut’ko, E. O. [JSC “R& D Center at Federal Grid Company of the Unified Power System” (Russian Federation); Vdoviko, V. P. [EMA Ltd. (Russian Federation); Demchenko, V. V. [JSC “Boguchanskaya HPP” (Russian Federation); Belyaev, S. G. [PKF Konif Ltd. (Russian Federation); Savel’ev, V. A. [Ivanovo State Power University (Russian Federation); L’vov, M. Yu., E-mail: timashova@nte-power.ru; L’vov, Yu. N. [JSC “R& D Center at Federal Grid Company of the Unified Power System” (Russian Federation)

    2015-03-15

    Methods of increasing the operating reliability of power transformers, autotransformers and shunting reactors in order to reduce the risk of damage, which accompany internal short circuits and equipment fires and explosions, are considered.

  13. A survey of SiC power MOSFETs short-circuit robustness and failure mode analysis

    DEFF Research Database (Denmark)

    Ceccarelli, L.; Reigosa, P. D.; Iannuzzo, F.

    2017-01-01

    The aim of this paper is to provide an extensive overview about the state-of-art commercially available SiC power MOSFET, focusing on their short-circuit ruggedness. A detailed literature investigation has been carried out, in order to collect and understand the latest research contribution within...... this topic and create a survey of the present scenario of SiC MOSFETs reliability evaluation and failure mode analysis, pointing out the evolution and improvements as well as the future challenges in this promising device technology....

  14. The effect of different solar simulators on the measurement of short-circuit current temperature coefficients

    Science.gov (United States)

    Curtis, H. B.; Hart, R. E., Jr.

    1982-01-01

    Gallium arsenide solar cells are considered for several high temperature missions in space. Both near-Sun and concentrator missions could involve cell temperatures on the order of 200 C. Performance measurements of cells at elevated temperatures are usually made using simulated sunlight and a matched reference cell. Due to the change in bandgap with increasing temperature at portions of the spectrum where considerable simulated irradiance is present, there are significant differences in measured short circuit current at elevated temperatures among different simulators. To illustrate this, both experimental and theoretical data are presented for gallium arsenide cells.

  15. Variations in the electrical short-circuit current decay for recombination lifetime and velocity measurements

    Science.gov (United States)

    Jung, Tae-Won; Lindholm, Fredrik A.; Neugroschel, Arnost

    1987-01-01

    An improved measurement system for electrical short-circuit current decay is presented that extends applicability of the method to silicon solar cells having an effective lifetime as low as 1 microsec. The system uses metal/oxide/semiconductor transistors as voltage-controlled switches. Advances in theory developed here increase precision and sensitivity in the determination of the minority-carrier recombination lifetime and recombination velocity. A variation of the method, which exploits measurements made on related back-surface field and back-ohmic contact devices, further improves precision and sensitivity. The improvements are illustrated by application to 15 different silicon solar cells.

  16. Comparison of short-circuit characteristics of trench gate and planar gate U-shaped channel SOI-LIGBTs

    Science.gov (United States)

    Zhang, Long; Zhu, Jing; Sun, Weifeng; Zhao, Minna; Huang, Xuequan; Chen, Jiajun; Shi, Longxing; Chen, Jian; Ding, Desheng

    2017-09-01

    Comparison of short-circuit (SC) characteristics of 500 V rated trench gate U-shaped channel (TGU) SOI-LIGBT and planar gate U-shaped channel (PGU) SOI-LIGBT is made for the first time in this paper. The on-state carrier profile of the TGU structure is reshaped by the dual trenches (a gate trench G1 and a hole barrier trench G2), which leads to a different conduction behavior from that of the PGU structure. The TGU structure exhibits a higher latchup immunity but a severer self-heating effect. At current density (JC) 640 A/cm2. Comparison of layouts and fabrication processes are also made between the two types of devices.

  17. Effect of notch depth of modified current collector on internal-short-circuit mitigation for lithium-ion battery

    Science.gov (United States)

    Wang, Meng; Noelle, Daniel J.; Shi, Yang; Le, Anh V.; Qiao, Yu

    2018-01-01

    Formation of internal short circuit (ISC) may result in catastrophic thermal runaway of lithium-ion battery (LIB). Among LIB cell components, direct contact between cathode and anode current collectors is most critical to the ISC behavior, yet is still relatively uninvestigated. In the current study, we analyze the effect of heterogeneity of current collector on the temperature increase of LIB cells subjected to mechanical abuse. The cathode current collector is modified by surface notches, so that it becomes effectively brittle and the ISC site can be isolated. Results from impact tests on LIB cells with modified current collectors suggest that their temperature increase can be negligible. The critical parameters include the failure strain and the failure work of modified current collector, both of which are related to the notch depth.

  18. Transient analysis of unbalanced short circuits of the ERDA-NASA 100 kW wind turbine alternator

    Science.gov (United States)

    Hwang, H. H.; Gilbert, L. J.

    1976-01-01

    Unbalanced short-circuit faults on the alternator of the ERDA-NASA Mod-O100-kW experimental wind turbine are studied. For each case, complete solutions for armature, field, and damper-circuit currents; short-circuit torque; and open-phase voltage are derived directly by a mathematical analysis. Formulated results are tabulated. For the Mod-O wind turbine alternator, numerical calculations are given, and results are presented by graphs. Comparisons for significant points among the more important cases are summarized. For these cases the transients are found to be potentially severe. The effect of the alternator neutral-to-ground impedance is evaluated.

  19. Modulation of neural circuits: how stimulus context shapes innate behavior in Drosophila.

    Science.gov (United States)

    Su, Chih-Ying; Wang, Jing W

    2014-12-01

    Remarkable advances have been made in recent years in our understanding of innate behavior and the underlying neural circuits. In particular, a wealth of neuromodulatory mechanisms have been uncovered that can alter the input-output relationship of a hereditary neural circuit. It is now clear that this inbuilt flexibility allows animals to modify their behavioral responses according to environmental cues, metabolic demands and physiological states. Here, we discuss recent insights into how modulation of neural circuits impacts innate behavior, with a special focus on how environmental cues and internal physiological states shape different aspects of feeding behavior in Drosophila. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Detection of Internal Short Circuit in Lithium Ion Battery Using Model-Based Switching Model Method

    Directory of Open Access Journals (Sweden)

    Minhwan Seo

    2017-01-01

    Full Text Available Early detection of an internal short circuit (ISCr in a Li-ion battery can prevent it from undergoing thermal runaway, and thereby ensure battery safety. In this paper, a model-based switching model method (SMM is proposed to detect the ISCr in the Li-ion battery. The SMM updates the model of the Li-ion battery with ISCr to improve the accuracy of ISCr resistance R I S C f estimates. The open circuit voltage (OCV and the state of charge (SOC are estimated by applying the equivalent circuit model, and by using the recursive least squares algorithm and the relation between OCV and SOC. As a fault index, the R I S C f is estimated from the estimated OCVs and SOCs to detect the ISCr, and used to update the model; this process yields accurate estimates of OCV and R I S C f . Then the next R I S C f is estimated and used to update the model iteratively. Simulation data from a MATLAB/Simulink model and experimental data verify that this algorithm shows high accuracy of R I S C f estimates to detect the ISCr, thereby helping the battery management system to fulfill early detection of the ISCr.

  1. Circuit-Host Coupling Induces Multifaceted Behavioral Modulations of a Gene Switch.

    Science.gov (United States)

    Blanchard, Andrew E; Liao, Chen; Lu, Ting

    2018-02-06

    Quantitative modeling of gene circuits is fundamentally important to synthetic biology, as it offers the potential to transform circuit engineering from trial-and-error construction to rational design and, hence, facilitates the advance of the field. Currently, typical models regard gene circuits as isolated entities and focus only on the biochemical processes within the circuits. However, such a standard paradigm is getting challenged by increasing experimental evidence suggesting that circuits and their host are intimately connected, and their interactions can potentially impact circuit behaviors. Here we systematically examined the roles of circuit-host coupling in shaping circuit dynamics by using a self-activating gene switch as a model circuit. Through a combination of deterministic modeling, stochastic simulation, and Fokker-Planck equation formalism, we found that circuit-host coupling alters switch behaviors across multiple scales. At the single-cell level, it slows the switch dynamics in the high protein production regime and enlarges the difference between stable steady-state values. At the population level, it favors cells with low protein production through differential growth amplification. Together, the two-level coupling effects induce both quantitative and qualitative modulations of the switch, with the primary component of the effects determined by the circuit's architectural parameters. This study illustrates the complexity and importance of circuit-host coupling in modulating circuit behaviors, demonstrating the need for a new paradigm-integrated modeling of the circuit-host system-for quantitative understanding of engineered gene networks. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  2. Controlled Conjugated Backbone Twisting for an Increased Open-Circuit Voltage while Having a High Short-Circuit Current in Poly(hexylthiophene) Derivatives

    KAUST Repository

    Ko, Sangwon; Hoke, Eric T.; Pandey, Laxman; Hong, Sanghyun; Mondal, Rajib; Risko, Chad; Yi, Yuanping; Noriega, Rodrigo; McGehee, Michael D.; Bré das, Jean-Luc; Salleo, Alberto; Bao, Zhenan

    2012-01-01

    and charge-transfer state energy of the polymer:fullerene BHJ solar cells increased substantially with the degree of twist induced within the conjugated backbone-due to an increase in the polymer ionization potential-while the short-circuit current decreased

  3. The Effect of Current-Limiting Reactors on the Tripping of Short Circuits in High-Voltage Electrical Equipment

    International Nuclear Information System (INIS)

    Volkov, M. S.; Gusev, Yu. P.; Monakov, Yu. V.; Cho, Gvan Chun

    2016-01-01

    The insertion of current-limiting reactors into electrical equipment operating at a voltage of 110 and 220 kV produces a change in the parameters of the transient recovery voltages at the contacts of the circuit breakers for disconnecting short circuits, which could be the reason for the increase in the duration of the short circuit, damage to the electrical equipment and losses in the power system. The results of mathematical modeling of the transients, caused by tripping of the short circuit in a reactive electric power transmission line are presented, and data are given on the negative effect of a current-limiting resistor on the rate of increase and peak value of the transient recovery voltages. Methods of ensuring the standard requirements imposed on the parameters of the transient recovery voltages when using current-limiting reactors in the high-voltage electrical equipment of power plants and substations are proposed and analyzed

  4. Three-Phase Short-Circuit Current Calculation of Power Systems with High Penetration of VSC-Based Renewable Energy

    Directory of Open Access Journals (Sweden)

    Niancheng Zhou

    2018-03-01

    Full Text Available Short-circuit current level of power grid will be increased with high penetration of VSC-based renewable energy, and a strong coupling between transient fault process and control strategy will change the fault features. The full current expression of VSC-based renewable energy was obtained according to transient characteristics of short-circuit current. Furtherly, by analyzing the closed-loop transfer function model of controller and current source characteristics presented in steady state during a fault, equivalent circuits of VSC-based renewable energy of fault transient state and steady state were proposed, respectively. Then the correctness of the theory was verified by experimental tests. In addition, for power grid with VSC-based renewable energy, superposition theorem was used to calculate AC component and DC component of short-circuit current, respectively, then the peak value of short-circuit current was evaluated effectively. The calculated results could be used for grid planning and design, short-circuit current management as well as adjustment of relay protection. Based on comparing calculation and simulation results of 6-node 500 kV Huainan power grid and 35-node 220 kV Huaisu power grid, the effectiveness of the proposed method was verified.

  5. LTS and FS inhibitory interneurons, short-term synaptic plasticity, and cortical circuit dynamics.

    Directory of Open Access Journals (Sweden)

    Itai Hayut

    2011-10-01

    Full Text Available Somatostatin-expressing, low threshold-spiking (LTS cells and fast-spiking (FS cells are two common subtypes of inhibitory neocortical interneuron. Excitatory synapses from regular-spiking (RS pyramidal neurons to LTS cells strongly facilitate when activated repetitively, whereas RS-to-FS synapses depress. This suggests that LTS neurons may be especially relevant at high rate regimes and protect cortical circuits against over-excitation and seizures. However, the inhibitory synapses from LTS cells usually depress, which may reduce their effectiveness at high rates. We ask: by which mechanisms and at what firing rates do LTS neurons control the activity of cortical circuits responding to thalamic input, and how is control by LTS neurons different from that of FS neurons? We study rate models of circuits that include RS cells and LTS and FS inhibitory cells with short-term synaptic plasticity. LTS neurons shift the RS firing-rate vs. current curve to the right at high rates and reduce its slope at low rates; the LTS effect is delayed and prolonged. FS neurons always shift the curve to the right and affect RS firing transiently. In an RS-LTS-FS network, FS neurons reach a quiescent state if they receive weak input, LTS neurons are quiescent if RS neurons receive weak input, and both FS and RS populations are active if they both receive large inputs. In general, FS neurons tend to follow the spiking of RS neurons much more closely than LTS neurons. A novel type of facilitation-induced slow oscillations is observed above the LTS firing threshold with a frequency determined by the time scale of recovery from facilitation. To conclude, contrary to earlier proposals, LTS neurons affect the transient and steady state responses of cortical circuits over a range of firing rates, not only during the high rate regime; LTS neurons protect against over-activation about as well as FS neurons.

  6. Short-circuit testing of monofilar Bi-2212 coils connected in series and in parallel

    International Nuclear Information System (INIS)

    Polasek, A; Dias, R; Serra, E T; Filho, O O; Niedu, D

    2010-01-01

    Superconducting Fault Current Limiters (SCFCL's) are one of the most promising technologies for fault current limitation. In the present work, resistive SCFCL components based on Bi-2212 monofilar coils are subjected to short-circuit testing. These SCFCL components can be easily connected in series and/or in parallel by using joints and clamps. This allows a considerable flexibility to developing larger SCFCL devices, since the configuration and size of the whole device can be easily adapted to the operational conditions. The single components presented critical current (Ic) values of 240-260 A, at 77 K. Short-circuits during 40-120 ms were applied. A single component can withstand a voltage drop of 126-252 V (0.3-0.6 V/cm). Components connected in series withstand higher voltage levels, whereas parallel connection allows higher rated currents during normal operation, but the limited current is also higher. Prospective currents as high as 10-40 kA (peak value) were limited to 3-9 kA (peak value) in the first half cycle.

  7. Methods for stable recording of short-circuit current in a Na+-transporting epithelium.

    Science.gov (United States)

    Gondzik, Veronika; Awayda, Mouhamed S

    2011-07-01

    Epithelial Na(+) transport as measured by a variety of techniques, including the short-circuit current technique, has been described to exhibit a "rundown" phenomenon. This phenomenon manifests as time-dependent decrease of current and resistance and precludes the ability to carry out prolonged experiments aimed at examining the regulation of this transport. We developed methods for prolonged stable recordings of epithelial Na(+) transport using modifications of the short-circuit current technique and commercial Ussing-type chambers. We utilize the polarized MDCK cell line expressing the epithelial Na(+) channel (ENaC) to describe these methods. Briefly, existing commercial chambers were modified to allow continuous flow of Ringer solution and precise control of such flow. Chamber manifolds and associated plumbing were modified to allow precise temperature clamp preventing temperature oscillations. Recording electrodes were modified to eliminate the use of KCl and prevent membrane depolarization from KCl leakage. Solutions utilized standard bicarbonate-based buffers, but all gasses were prehydrated to clamp buffer osmolarity. We demonstrate that these modifications result in measurements of current and resistance that are stable for at least 2 h. We further demonstrate that drifts in osmolarity similar to those obtained before prior to our modifications can lead to a decrease of current and resistance similar to those attributed to rundown.

  8. Adrenomedullin increases the short-circuit current in the mouse seminal vesicle: actions on chloride secretion.

    Science.gov (United States)

    Liao, S B; Cheung, K H; O, W S; Tang, Fai

    2014-08-01

    Adrenomedullin (ADM) may regulate seminal vesicle fluid secretion, and this may affect sperm quality. In this study, we investigated the effect of ADM on chloride secretion in the mouse seminal vesicle. The presence of ADM in mouse seminal vesicle was confirmed using immunostaining, and the molecular species was determined using gel filtration chromatography coupled with enzyme-linked assay for ADM. The effects of ADM on chloride secretion were studied by short-circuit current technique in a whole-mount preparation of mouse seminal vesicle in an Ussing chamber. The effects of specific ADM and calcitonin gene-related peptide (CGRP) receptor antagonists were investigated. Whether the ADM effect depended on the cAMP- and/or calcium-activated chloride channel was also studied using specific chloride channel blockers. The results showed that ADM was present in seminal vesicle epithelial cells. The major molecular species was precursor in the mouse seminal vesicle. ADM increased short-circuit current through the calcium-activated chloride channel in mouse seminal vesicle, and CGRP receptor was involved. We conclude that ADM may regulate chloride and fluid secretion from the seminal vesicle, which may affect the composition of the seminal plasma bathing the sperm and, hence, fertility. © 2014 by the Society for the Study of Reproduction, Inc.

  9. Synaptic plasticity, neural circuits, and the emerging role of altered short-term information processing in schizophrenia

    Science.gov (United States)

    Crabtree, Gregg W.; Gogos, Joseph A.

    2014-01-01

    Synaptic plasticity alters the strength of information flow between presynaptic and postsynaptic neurons and thus modifies the likelihood that action potentials in a presynaptic neuron will lead to an action potential in a postsynaptic neuron. As such, synaptic plasticity and pathological changes in synaptic plasticity impact the synaptic computation which controls the information flow through the neural microcircuits responsible for the complex information processing necessary to drive adaptive behaviors. As current theories of neuropsychiatric disease suggest that distinct dysfunctions in neural circuit performance may critically underlie the unique symptoms of these diseases, pathological alterations in synaptic plasticity mechanisms may be fundamental to the disease process. Here we consider mechanisms of both short-term and long-term plasticity of synaptic transmission and their possible roles in information processing by neural microcircuits in both health and disease. As paradigms of neuropsychiatric diseases with strongly implicated risk genes, we discuss the findings in schizophrenia and autism and consider the alterations in synaptic plasticity and network function observed in both human studies and genetic mouse models of these diseases. Together these studies have begun to point toward a likely dominant role of short-term synaptic plasticity alterations in schizophrenia while dysfunction in autism spectrum disorders (ASDs) may be due to a combination of both short-term and long-term synaptic plasticity alterations. PMID:25505409

  10. Experimental investigation of internal short circuits in lithium-ion batteries

    Science.gov (United States)

    Poramapojana, Poowanart

    With outstanding performance of Lithium-ion batteries, they have been widely used in many applications. For hybrid electric vehicles and electric vehicles, customer concerns of battery safety have been raised as a number of car accidents were reported. To evaluate safety performance of these batteries, a nail penetration test is used to simulate and induce internal short circuits instantaneously. Efforts to explain failure mechanisms of the penetration using electrochemical-thermal coupled models have been proposed. However, there is no experimental validation because researchers lack of a diagnostic tool to acquire important cell characteristics at a shorting location, such as shorting current and temperature. In this present work, diagnostic nails have been developed to acquire nail center temperatures and shorting current flow through the nails during nail penetration tests. Two types of cylindrical wall structures are used to construct the nails: a double-layered stainless steel wall and a composite cylindrical wall. An inner hollow cylinder functions as a sensor holder where two wires and one thermocouple are installed. To study experimental reproducibility and repeatability of experimental results, two nail penetration tests are conducted using two diagnostic nails with the double-layered wall. Experimental data shows that the shorting resistance at the initial stage is a critical parameter to obtain repeatable results. The average shorting current for both tests is approximately 40 C-rate. The fluctuation of the shorting current is due to random sparks and fire caused loose contacts between the nail and the cell components. Moreover, comparative experimental results between the two wall structures reveal that the wall structure does not affect the cell characteristics and Ohmic heat generation of the nail. The wall structure effects to current measurements inside the nail. With the composite wall, the actual current redistribution into the inner wall is

  11. Robustness of a rhythmic circuit to short- and long-term temperature changes.

    Science.gov (United States)

    Tang, Lamont S; Taylor, Adam L; Rinberg, Anatoly; Marder, Eve

    2012-07-18

    Recent computational and experimental work has shown that similar network performance can result from variable sets of synaptic and intrinsic properties. Because temperature is a global perturbation that differentially influences every biological process within the nervous system, one might therefore expect that individual animals would respond differently to temperature. Nonetheless, the phase relationships of the pyloric rhythm of the stomatogastric ganglion (STG) of the crab, Cancer borealis, are remarkably invariant between 7 and 23°C (Tang et al., 2010). Here, we report that, when isolated STG preparations were exposed to more extreme temperature ranges, their networks became nonrhythmic, or "crashed", in a reversible fashion. Animals were acclimated for at least 3 weeks at 7, 11, or 19°C. When networks from the acclimated animals were perturbed by acute physiologically relevant temperature ramps (11-23°C), the network frequency and phase relationships were independent of the acclimation group. At high acute temperatures (>23°C), circuits from the cold-acclimated animals produced less-regular pyloric rhythms than those from warm-acclimated animals. At high acute temperatures, phase relationships between pyloric neurons were more variable from animal to animal than at moderate acute temperatures, suggesting that individual differences across animals in intrinsic circuit parameters are revealed at high temperatures. This shows that individual and variable neuronal circuits can behave similarly in normal conditions, but their behavior may diverge when confronted with extreme external perturbations.

  12. Developing an Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

    Science.gov (United States)

    Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

    2009-01-01

    To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.

  13. Effects of Armature Winding Segmentation with Multiple Converters on the Short Circuit Torque of 10-MW Superconducting Wind Turbine Generators

    DEFF Research Database (Denmark)

    Liu, Dong; Polinder, Henk; Abrahamsen, Asger Bech

    2017-01-01

    Superconducting synchronous generators (SCSGs) are drawing more attention in large direct-drive wind turbine applications. Despite low weight and compactness, the short circuit torque of an SCSG may be too high for wind turbine constructions due to a large magnetic air gap of an SCSG. This paper...... aims at assessing the effects of armature winding segmentation on reducing the short circuit torque of 10-MW SCSGs. A concept of armature winding segmentation with multiple power electronic converters is presented. Four SCSG designs using different topologies are examined. Results show that armature...... winding segmentation effectively reduce the short circuit torque in all the four SCSG designs when one segment is shorted at the terminal....

  14. Digital-circuit analysis of short-gate tunnel FETs for low-voltage applications

    International Nuclear Information System (INIS)

    Zhuge, Jing; Huang, Ru; Wang, Yangyuan; Verhulst, Anne S; Vandenberghe, William G; Dehaene, Wim; Groeseneken, Guido

    2011-01-01

    This paper investigates the potential of tunnel field-effect transistors (TFETs), with emphasis on short-gate TFETs, by simulation for low-power digital applications having a supply voltage lower than 0.5 V. A transient study shows that the tunneling current has a negligible contribution in charging and discharging the gate capacitance of TFETs. In spite of a higher resistance region in the short-gate TFET, the gate (dis)charging speed still meets low-voltage application requirements. A circuit analysis is performed on short-gate TFETs with different materials, such as Si, Ge and heterostructures in terms of voltage overshoot, delay, static power, energy consumption and energy delay product (EDP). These results are compared to MOSFET and full-gate TFET performance. It is concluded that short-gate heterostructure TFETs (Ge–source for nTFET, In 0.6 Ga 0.4 As–source for pTFET) are promising candidates to extend the supply voltage to lower than 0.5 V because they combine the advantage of a low Miller capacitance, due to the short-gate structures, and strong drive current in TFETs, due to the narrow bandgap material in the source. At a supply voltage of 0.4 V and for an EOT and channel length of 0.6 nm and 40 nm, respectively, a three-stage inverter chain based on short-gate heterostructure TFETs saves 40% energy consumption per cycle at the same delay and shows 60%–75% improvement of EDP at the same static power, compared to its full-gate counterpart. When compared to the MOSFET, better EDP can be achieved in the heterostructure TFET especially at low static power consumption

  15. An alternative explanation for the occurrence of short circuit current increases in the small intestine following challenge by bacterial enterotoxins.

    Science.gov (United States)

    Lucas, M L

    2013-10-01

    Secretory diarrhoeal disease due to enterotoxins is thought to arise from the enhancement to pathologically high rates of normally occurring chloride ion and therefore fluid secretion from enterocytes. In support of this concept, many enterotoxins increase intestinal short-circuit current, regarded now as faithfully reflecting the increased chloride ion secretion. Contradicting this assumption, STa reduces absorption but does not cause secretion in vivo although short-circuit current is increased in vitro. There is therefore a mismatch between an assumed enterocyte mediated secretory event that should but does not cause net fluid secretion and an undoubtedly increased short-circuit current. It is proposed here that short-circuit current increases are not themselves secretory events but result from interrupted fluid absorption. A noteworthy feature of compounds that inhibit the increase in short-circuit current is that the majority are vasoactive, neuroactive or both. In general, vasodilator substances increase current. An alternative hypothesis for the origin of short-circuit current increases is that these result from reflex induction of electrogenic fluid absorption. This reflex enhances a compensatory response that is also present at a cellular level. An intestinal reflex is therefore proposed by which decreases in interstitial and intravascular volume or pressure within the intestine initiate an electrogenic fluid absorption mechanism that compensates for the loss of electrically neutral fluid absorption. This hypothesis would explain the apparently complex pharmacology of short-circuit current increases since many depressor substances have receptors in common with enterocytes and enteric nerves. The proposed alternative view of the origin of short-circuit current increases assumes that these do not represent chloride secretion from the enterocytes. This view may therefore aid the successful development of anti-diarrhoeal drugs to overcome a major cause of

  16. Transient stability of DFIG wind turbines at an external short-circuit fault

    DEFF Research Database (Denmark)

    Sun, Tao; Chen, Zhe; Blaabjerg, Frede

    2005-01-01

    The fast development of wind power generation brings new requirements for wind turbine integration into the network. After clearance of an external short-circuit fault, gridconnected wind turbines should restore their normal operation without power loss caused by disconnections. This article...... are described in detail. The transient process of grid-connected wind turbines with DFIGs at an external shortcircuit fault is analysed, and in critical post-fault situations a measure is proposed for the voltage recovery of DFIG wind turbines after fault clearance. Simulation results demonstrate...... that in uncritical post-fault situations the control schemes are able to restore the wind turbine's normal operation without disconnections.lt is also proved that the proposed measure is effective in re-establishing the voltage at the wind turbine terminal in critical post-fault situations....

  17. Short-circuit current improvement in thin cells with a gridded back contact

    Science.gov (United States)

    Giuliano, M.; Wohlgemuth, J.

    1980-01-01

    The use of gridded back contact on thin silicon solar cells 50 micrometers was investigated. An unexpected increase in short circuit current of almost 10 percent was experienced for 2 cm x 2 cm cells. Control cells with the standard continuous contact metallization were fabricated at the same time as the gridded back cells with all processes identical up to the formation of the back contact. The gridded back contact pattern was delineated by evaporation of Ti-Pd over a photo-resist mask applied to the back of the wafer; the Ti-Pd film on the controls was applied in the standard fashion in a continuous layer over the back of the cell. The Ti-Pd contacts were similarly applied to the front of the wafer, and the grid pattern on both sides of the cell was electroplated with 8-10 micrometers of silver.

  18. Growth Mechanism Studies of ZnO Nanowires: Experimental Observations and Short-Circuit Diffusion Analysis.

    Science.gov (United States)

    Shih, Po-Hsun; Wu, Sheng Yun

    2017-07-21

    Plenty of studies have been performed to probe the diverse properties of ZnO nanowires, but only a few have focused on the physical properties of a single nanowire since analyzing the growth mechanism along a single nanowire is difficult. In this study, a single ZnO nanowire was synthesized using a Ti-assisted chemical vapor deposition (CVD) method to avoid the appearance of catalytic contamination. Two-dimensional energy dispersive spectroscopy (EDS) mapping with a diffusion model was used to obtain the diffusion length and the activation energy ratio. The ratio value is close to 0.3, revealing that the growth of ZnO nanowires was attributed to the short-circuit diffusion.

  19. On the short circuit resilience of organic solar cells: prediction and validation.

    Science.gov (United States)

    Oostra, A Jolt; Smits, Edsger C P; de Leeuw, Dago M; Blom, Paul W M; Michels, Jasper J

    2015-09-07

    The operational characteristics of organic solar cells manufactured with large area processing methods suffers from the occurrence of short-circuits due to defects in the photoactive thin film stack. In this work we study the effect of a shunt resistance on an organic solar cell and demonstrate that device performance is not affected negatively as long as the shunt resistance is higher than approximately 1000 Ohm. By studying charge transport across PSS-lithium fluoride/aluminum (LiF/Al) shunting junctions we show that this prerequisite is already met by applying a sufficiently thick (>1.5 nm) LiF layer. We demonstrate that this remarkable shunt-resilience stems from the formation of a significant charge transport barrier at the PSS-LiF/Al interface. We validate our predictions by fabricating devices with deliberately severed photoactive layers and find an excellent agreement between the calculated and experimental current-voltage characteristics.

  20. Short circuit current changes in electron irradiated GaAlAs/GaAs solar cells

    Science.gov (United States)

    Walker, G. H.; Conway, E. J.

    1978-01-01

    Heteroface p-GaAlAs/p-GaAs/n-GaAs solar cells with junction depths of 0.8, 1.5, and 4 microns were irradiated with 1 MeV electrons. The short-circuit current for the 4 micron junction depth cells is significantly reduced by the electron irradiation. Reduction of the junction depth to 1.5 microns improves the electron radiation resistance of the cells while further reduction of the junction depth to 0.8 microns improves the stability of the cells even more. Primary degradation is in the blue region of the spectrum. Considerable recovery of lost response is obtained by annealing the cells at 200 C. Computer modeling shows that the degradation is caused primarily by a reduction in the minority carrier diffusion length in the p-GaAs.

  1. Modulation of neural circuits: how stimulus context shapes innate behavior in Drosophila

    OpenAIRE

    Su, Chih-Ying; Wang, Jing W.

    2014-01-01

    Remarkable advances have been made in recent years in our understanding of innate behavior and the underlying neural circuits. In particular, a wealth of neuromodulatory mechanisms have been uncovered that can alter the input-output relationship of a hereditary neural circuit. It is now clear that this inbuilt flexibility allows animals to modify their behavioral responses according to environmental cues, metabolic demands and physiological states. Here, we discuss recent insights into how mo...

  2. Effect of Short-Circuit Pathways on Water Quality in Selected Confined Aquifers (Invited)

    Science.gov (United States)

    McMahon, P. B.

    2010-12-01

    Confined aquifers in the United States generally contain fewer anthropogenic contaminants than unconfined aquifers because confined aquifers often contain water recharged prior to substantial human development and redox conditions are more reducing, which favors degradation of common contaminants like nitrate and chlorinated solvents. Groundwater in a confined part of the High Plains aquifer near York, Nebraska had an adjusted radiocarbon age of about 2,000 years, and groundwater in a confined part of the Floridan aquifer near Tampa, Florida had apparent ages greater than 60 years on the basis of tritium measurements. Yet compounds introduced more recently into the environment (anthropogenic nitrate and volatile organic compounds) were detected in selected public-supply wells completed in both aquifers. Depth-dependent measurements of flow and chemistry in the pumping supply wells, groundwater age dating, numerical modeling of groundwater flow, and other monitoring data indicated that the confined aquifers sampled by the supply wells were connected to contaminated unconfined aquifers by short-circuit pathways. In the High Plains aquifer, the primary pathways appeared to be inactive irrigation wells screened in both the unconfined and confined aquifers. In the Floridan aquifer, the primary pathways were karst sinkholes and conduits. Heavy pumping in both confined systems exacerbated the problem by reducing the potentiometric surface and increasing groundwater velocities, thus enhancing downward gradients and reducing reaction times for processes like denitrification. From a broader perspective, several confined aquifers in the U.S. have experienced large declines in their potentiometric surfaces because of groundwater pumping and this could increase the potential for contamination in those aquifers, particularly where short-circuit pathways connect them to shallower, contaminated sources of water, such as was observed in York and Tampa.

  3. Failure Analysis of Short-Circuited Lithium-Ion Battery with Nickel-Manganese-Cobalt/Graphite Electrode.

    Science.gov (United States)

    Lee, Seung-Mi; Kim, Jea-Yeon; Byeon, Jai-Won

    2018-09-01

    Accidental failures and explosions of lithium-ion batteries have been reported in recent years. To determine the root causes and mechanisms of these failures from the perspective of material degradation, failure analysis was conducted for an intentionally shorted lithium-ion battery. The battery was subjected to electrical overcharging and mechanical pressing to simulate internal short-circuiting. After in situ measurement of the temperature increase during the short-circuiting of the electrodes, the disassembled battery components (i.e., the anode, cathode, and separator) were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Regardless of the simulated short-circuit method (mechanical or electrical), damage was observed in the shorted batteries. Numerous small cracks and chemical reaction products were observed on the electrode surface, along with pore shielding on the separator. The event of short-circuiting increased the surface temperature of the battery to approximately 90 °C, which prompted the deterioration and decomposition of the electrolyte, thus affecting the overall battery performance; this was attributed to the decomposition of the lithium salt at 60 °C. The gas generation due to the breakdown of the electrolyte causes pressure accumulation inside the cell; therefore, the electrolyte leaks.

  4. Implications of electronic short circuiting in plasma sprayed solid oxide fuel cells on electrode performance evaluation by electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    White, B.D. [Department of Mechanical Engineering, The University of British Columbia, 2054-6250 Applied Sciences Lane, Vancouver, British Columbia (Canada); Kesler, O. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, Ontario (Canada)

    2008-02-15

    Electronic short circuiting of the electrolyte in a solid oxide fuel cell (SOFC) arising from flaws in the plasma spray fabrication process has been found to have a significant effect on the perceived performance of the electrodes, as evaluated by electrochemical impedance spectroscopy (EIS). The presence of a short circuit has been found to lead to the underestimation of the electrode polarization resistance (R{sub p}) and hence an overestimation of electrode performance. The effect is particularly noticeable when electrolyte resistance is relatively high, for example during low to intermediate temperature operation, leading to an obvious deviation from the expected Arrhenius-type temperature dependence of R{sub p}. A method is developed for determining the real electrode performance from measurements of various cell properties, and strategies for eliminating the occurrence of short circuiting in plasma sprayed cells are identified. (author)

  5. Implications of electronic short circuiting in plasma sprayed solid oxide fuel cells on electrode performance evaluation by electrochemical impedance spectroscopy

    Science.gov (United States)

    White, B. D.; Kesler, O.

    Electronic short circuiting of the electrolyte in a solid oxide fuel cell (SOFC) arising from flaws in the plasma spray fabrication process has been found to have a significant effect on the perceived performance of the electrodes, as evaluated by electrochemical impedance spectroscopy (EIS). The presence of a short circuit has been found to lead to the underestimation of the electrode polarization resistance (R p) and hence an overestimation of electrode performance. The effect is particularly noticeable when electrolyte resistance is relatively high, for example during low to intermediate temperature operation, leading to an obvious deviation from the expected Arrhenius-type temperature dependence of R p. A method is developed for determining the real electrode performance from measurements of various cell properties, and strategies for eliminating the occurrence of short circuiting in plasma sprayed cells are identified.

  6. Transient analysis of the output short-circuit fault of high power and high voltage DC power supply

    International Nuclear Information System (INIS)

    Yang Zhigang; Zhang Jian; Huang Yiyun; Hao Xu; Sun Haozhang; Guo Fei

    2014-01-01

    The transient conditions of output short-circuit fault of high voltage DC power supply was introduced, and the energy of power supply injecting into klystron during the protection process of three-electrode gas switch were analyzed and calculated in detail when klystron load happening electrode arc faults. The results of calculation and simulation are consistent with the results of the experiment. When the output short-circuit fault of high voltage power supply occurs, switch can be shut off in the microsecond, and the short circuit current can be controlled in 200 A. It has verified the rapidity and reliability of the three-electrode gas switch protection, and it has engineering application value. (authors)

  7. Increasing emitter efficiency in 3.3-kV enhanced trench IGBTs for higher short-circuit capability

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Iannuzzo, Francesco; Rahimo, Munaf

    2018-01-01

    In this paper, a 3.3-kV Enhanced Trench IGBT has been designed with a high emitter efficiency, for improving its short-circuit robustness. The carrier distribution profile has been shaped in a way that it is possible to increase the electric field at the surface of the IGBT, and thereby, counteract...... the Kirk Effect onset. This design approach is beneficial for mitigating high-frequency oscillations, typically observed in IGBTs under short-circuit conditions. The effectiveness of the proposed design rule is validated by means of mixed-mode device simulations. Then, two IGBTs have been fabricated...... with different emitter efficiencies and tested under short circuit, validating that the high-frequency oscillations can be mitigated, with higher emitter efficiency IGBT designs....

  8. Transient Analysis of Grid-Connected Wind Turbines with DFIG After an External Short-Circuit Fault

    DEFF Research Database (Denmark)

    Sun, Tao; Chen, Zhe; Blaabjerg, Frede

    2004-01-01

    The fast development of wind power generation brings new requirements for wind turbine integration to the network. After the clearance of an external short-circuit fault, the grid-connected wind turbine should restore its normal operation with minimized power losses. This paper concentrates...... on transient analysis of variable speed wind turbines with doubly fed induction generator (DFIG) after an external short-circuit fault. A simulation model of a MW-level variable speed wind turbine with DFIG developed in PSCAD/EMTDC is presented, and the control and protection schemes are described in detail....... After the clearance of an external short-circuit fault the control schemes manage to restore the wind turbine?s normal operation, and their performances are demonstrated by simulation results both during the fault and after the clearance of the fault....

  9. An Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers-Part I

    Science.gov (United States)

    Courey, Karim; Wright, Clara; Asfour, Shihab; Bayliss, Jon; Ludwig, Larry

    2008-01-01

    Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has a currently unknown probability associated with it. Due to contact resistance, electrical shorts may not occur at lower voltage levels. In this experiment, we study the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From this data, we can estimate the probability of an electrical short, as a function of voltage, given that a free tin whisker has bridged two adjacent exposed electrical conductors. In addition, three tin whiskers grown from the same Space Shuttle Orbiter card guide used in the aforementioned experiment were cross sectioned and studied using a focused ion beam (FIB).

  10. The short-circuit current of the ileum, but not the colon, is altered in the streptozotocin diabetic rat.

    Science.gov (United States)

    Forrest, Abigail; Makwana, Rajesh; Parsons, Mike

    2006-02-01

    Ion transport in control and streptozotocin-diabetic rat colon and ileum was studied using the Ussing chamber technique. No differences were observed between control and diabetic colonic mucosal short-circuit current under either basal or carbachol (100 nmol/L-1 micromol/L)-stimulated or prostaglandin E2 (100 nmol/L-1 micromol/L)-stimulated conditions. Similarly to colonic tissues, no differences in the short circuit current in either carbachol-stimulated or prostaglandin E2-stimulated tissues were observed between control and diabetic ileal mucosa. The basal diabetic ileal short circuit current (99.58 +/- 22.67 microA) was significantly greater than that of control ileal tissues (29.67 +/- 4.45 microA). This difference was abolished by the sodium-glucose-cotransporter inhibitor, phloridzin (50 micromol/L) (118.00 +/- 28.09 microA vs. 25.60 +/- 4.59 microA) and was also prevented by the replacement of glucose with mannitol in the buffer bathing the apical side of the tissue (control: 17.05 +/- 5.85 microA vs. 17.90 +/- 3.10 microA). Acetazolamide (450 micromol/L; a carbonic anhydrase inhibitor), amiloride, and bumetanide (100 micromol/L each; Na+-channel blockers), piroxicam (50 micromol/L; a COX1 cyclooxygenase inhibitor), and ouabain (1 mmol/L; a K+ transport inhibitor) had no effect on the basal short circuit current of either control or diabetic ileal tissues. This indicated that the alteration in the basal short circuit current of diabetic ileal tissues was due to a change in cellular glucose transport, whereas the evoked changes in short circuit current were unaffected by the diabetic state.

  11. Technical Study on Improvement of Endurance Capability of Limit Short-circuit Current of Charge Control SMART Meter

    Science.gov (United States)

    Li, W. W.; Du, Z. Z.; Yuan, R. m.; Xiong, D. Z.; Shi, E. W.; Lu, G. N.; Dai, Z. Y.; Chen, X. Q.; Jiang, Z. Y.; Lv, Y. G.

    2017-10-01

    Smart meter represents the development direction of energy-saving smart grid in the future. The load switch, one of the core parts of smart meter, should be of high reliability, safety and endurance capability of limit short-circuit current. For this reason, this paper discusses the quick simulation of relationship between attraction and counterforce of load switch without iteration, establishes dual response surface model of attraction and counterforce and optimizes the design scheme of load switch for charge control smart meter, thus increasing electromagnetic attraction and spring counterforce. In this way, this paper puts forward a method to improve the withstand capacity of limit short-circuit current.

  12. Short circuit experiment on an FCL coil wound with YBCO tape with a high-resistance stabilizing layer

    Energy Technology Data Exchange (ETDEWEB)

    Yazawa, T; Iijima, Y; Saito, T [Toshiba Corporation, Fujikura Ltd (Japan); Amemiya, N [Toshiba Corporation, Yokohama National University (Japan); Shiohara, Y [Toshiba Corporation, ISTEC SRL (Japan); Koyanagi, K; Ono, M; Urata, M, E-mail: takashi.yazawa@toshiba.co.jp

    2008-02-15

    One of the programs in the Ministry of Economy, Trade and Industry regarding R and D for developing YBCO conductors is to evaluate the suitability of the conductors in several applications. This paper focuses on one of the expected power applications, namely, a fault current limiter (FCL). YBCO tape conductors with ion beam assisted deposition (IBAD) substrates are used in this work. In order to increase the resistivity of the conductor, which is preferable for FCL applications, the thickness of a protective layer made of silver was decreased as much as possible. After obtaining the required current limiting performance in short sample experiments, a model coil was developed aiming at 6.6 kV-class FCLs. Short circuit experiments were conducted with a short-circuit generator. The coil successfully suppressed a short-circuit current of over 1.4 kA to about 500 A under an applied voltage of 3.8 kV, which is the nominal phase-to-ground voltage. The coil also suppressed a short-circuit current of 17 kA down to 700 A. The experimental results are as expected and show promise toward FCL applications.

  13. Short circuit experiment on an FCL coil wound with YBCO tape with a high-resistance stabilizing layer

    International Nuclear Information System (INIS)

    Yazawa, T; Iijima, Y; Saito, T; Amemiya, N; Shiohara, Y; Koyanagi, K; Ono, M; Urata, M

    2008-01-01

    One of the programs in the Ministry of Economy, Trade and Industry regarding R and D for developing YBCO conductors is to evaluate the suitability of the conductors in several applications. This paper focuses on one of the expected power applications, namely, a fault current limiter (FCL). YBCO tape conductors with ion beam assisted deposition (IBAD) substrates are used in this work. In order to increase the resistivity of the conductor, which is preferable for FCL applications, the thickness of a protective layer made of silver was decreased as much as possible. After obtaining the required current limiting performance in short sample experiments, a model coil was developed aiming at 6.6 kV-class FCLs. Short circuit experiments were conducted with a short-circuit generator. The coil successfully suppressed a short-circuit current of over 1.4 kA to about 500 A under an applied voltage of 3.8 kV, which is the nominal phase-to-ground voltage. The coil also suppressed a short-circuit current of 17 kA down to 700 A. The experimental results are as expected and show promise toward FCL applications

  14. Internal short circuit and accelerated rate calorimetry tests of lithium-ion cells: Considerations for methane-air intrinsic safety and explosion proof/flameproof protection methods.

    Science.gov (United States)

    Dubaniewicz, Thomas H; DuCarme, Joseph P

    2016-09-01

    Researchers with the National Institute for Occupational Safety and Health (NIOSH) studied the potential for lithium-ion cell thermal runaway from an internal short circuit in equipment for use in underground coal mines. In this third phase of the study, researchers compared plastic wedge crush-induced internal short circuit tests of selected lithium-ion cells within methane (CH 4 )-air mixtures with accelerated rate calorimetry tests of similar cells. Plastic wedge crush test results with metal oxide lithium-ion cells extracted from intrinsically safe evaluated equipment were mixed, with one cell model igniting the chamber atmosphere while another cell model did not. The two cells models exhibited different internal short circuit behaviors. A lithium iron phosphate (LiFePO 4 ) cell model was tolerant to crush-induced internal short circuits within CH 4 -air, tested under manufacturer recommended charging conditions. Accelerating rate calorimetry tests with similar cells within a nitrogen purged 353-mL chamber produced ignitions that exceeded explosion proof and flameproof enclosure minimum internal pressure design criteria. Ignition pressures within a 20-L chamber with 6.5% CH 4 -air were relatively low, with much larger head space volume and less adiabatic test conditions. The literature indicates that sizeable lithium thionyl chloride (LiSOCl 2 ) primary (non rechargeable) cell ignitions can be especially violent and toxic. Because ignition of an explosive atmosphere is expected within explosion proof or flameproof enclosures, there is a need to consider the potential for an internal explosive atmosphere ignition in combination with a lithium or lithium-ion battery thermal runaway process, and the resulting effects on the enclosure.

  15. High short-circuit current density CdTe solar cells using all-electrodeposited semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Echendu, O.K., E-mail: oechendu@yahoo.com; Fauzi, F.; Weerasinghe, A.R.; Dharmadasa, I.M.

    2014-04-01

    CdS/CdTe and ZnS/CdTe n–n heterojunction solar cells have been fabricated using all-electrodeposited semiconductors. The best devices show remarkable high short-circuit current densities of 38.5 mAcm{sup −2} and 47.8 mAcm{sup −2}, open-circuit voltages of 630 mV and 646 mV and conversion efficiencies of 8.0% and 12.0% respectively. The major strength of these device structures lies in the combination of n–n heterojunction with a large Schottky barrier at the n-CdTe/metal back contact which provides the required band bending for the separation of photo-generated charge carriers. This is in addition to the use of a high quality n-type CdTe absorber layer with high electron mobility. The potential barrier heights estimated for these devices from the current–voltage characteristics exceed 1.09 eV and 1.13 eV for CdS/CdTe and ZnS/CdTe cells respectively. The diode rectification factors of both devices are in excess of four orders of magnitude with reverse saturation current densities of 1.0 × 10{sup −7} Acm{sup −2} and 4.0 × 10{sup −7} Acm{sup −2} respectively. These all-electrodeposited solar cell device structures are currently being studied and developed as an alternative to the well-known p–n junction structures which utilise chemical bath-deposited CdS. The preliminary material growth, device fabrication and assessment results are presented in this paper. - Highlights: • Two-electrode deposition. • High J{sub sc} Schottky barrier solar cells. • CdCl{sub 2} + CdF{sub 2} treatment.

  16. Behavioral Synthesis of Asynchronous Circuits Using Syntax Directed Translation as Backend

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Sparsø, Jens; Madsen, Jan

    2009-01-01

    The current state-of-the art in high-level synthesis of asynchronous circuits is syntax directed translation, which performs a one-to-one mapping of a HDL-description into a corresponding circuit. This paper presents a method for behavioral synthesis of asynchronous circuits which builds on top...... description language Balsa [1]. This ”conventional” template architecture allows us to adapt traditional synchronous synthesis techniques for resource sharing, scheduling, binding etc, to the domain of asynchronous circuits. A prototype tool has been implemented on top of the Balsa framework, and the method...... is illustrated through the implementation of a set of example circuits. The main contributions of the paper are: the fundamental idea, the template architecture and its implementation using asynchronous handshake components, and the implementation of a prototype tool....

  17. Short-Circuit Fault Detection and Classification Using Empirical Wavelet Transform and Local Energy for Electric Transmission Line.

    Science.gov (United States)

    Huang, Nantian; Qi, Jiajin; Li, Fuqing; Yang, Dongfeng; Cai, Guowei; Huang, Guilin; Zheng, Jian; Li, Zhenxin

    2017-09-16

    In order to improve the classification accuracy of recognizing short-circuit faults in electric transmission lines, a novel detection and diagnosis method based on empirical wavelet transform (EWT) and local energy (LE) is proposed. First, EWT is used to deal with the original short-circuit fault signals from photoelectric voltage transformers, before the amplitude modulated-frequency modulated (AM-FM) mode with a compactly supported Fourier spectrum is extracted. Subsequently, the fault occurrence time is detected according to the modulus maxima of intrinsic mode function (IMF₂) from three-phase voltage signals processed by EWT. After this process, the feature vectors are constructed by calculating the LE of the fundamental frequency based on the three-phase voltage signals of one period after the fault occurred. Finally, the classifier based on support vector machine (SVM) which was constructed with the LE feature vectors is used to classify 10 types of short-circuit fault signals. Compared with complementary ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and improved CEEMDAN methods, the new method using EWT has a better ability to present the frequency in time. The difference in the characteristics of the energy distribution in the time domain between different types of short-circuit faults can be presented by the feature vectors of LE. Together, simulation and real signals experiment demonstrate the validity and effectiveness of the new approach.

  18. Microscale failure mechanisms leading to internal short circuit in Li-ion batteries under complex loading scenarios

    NARCIS (Netherlands)

    Sahraei, E.; Bosco, E.; Dixon, B.; Lai, B.

    2016-01-01

    One of the least understood mechanisms of Li-ion batteries is the development of internal short circuits under mechanical loads. In this study, a micro mechanical model is developed and subjected to various loading scenarios to understand the sequence of failure in the multi-layer, multi-material

  19. Fast and Accurate Icepak-PSpice Co-Simulation of IGBTs under Short-Circuit with an Advanced PSpice Model

    DEFF Research Database (Denmark)

    Wu, Rui; Iannuzzo, Francesco; Wang, Huai

    2014-01-01

    A basic problem in the IGBT short-circuit failure mechanism study is to obtain realistic temperature distribution inside the chip, which demands accurate electrical simulation to obtain power loss distribution as well as detailed IGBT geometry and material information. This paper describes an unp...

  20. EQUATIONS OF ELECTRIC MOTOR POWER SUPPLY UNIT DISSYMMETRY UNDER PHASE-TO-PHASE SHORT-CIRCUIT FAULT

    Directory of Open Access Journals (Sweden)

    V.Y. Tchaban

    2013-10-01

    Full Text Available In the paper, a formula is introduced to calculate electric motor supply unit voltage under feeding by a common transformer in the condition of a phase-to-phase short-circuit. The formula is used in every time step of electromechanical state equations integration.

  1. An iterative approach for symmetrical and asymmetrical Short-circuit calculations with converter-based connected renewable energy sources

    DEFF Research Database (Denmark)

    Göksu, Ömer; Teodorescu, Remus; Bak-Jensen, Birgitte

    2012-01-01

    As more renewable energy sources, especially more wind turbines are installed in the power system, analysis of the power system with the renewable energy sources becomes more important. Short-circuit calculation is a well known fault analysis method which is widely used for early stage analysis...

  2. Mode of the short circuit in the direct current electric traction network with different feed charts of fyder area

    Directory of Open Access Journals (Sweden)

    P. Mihalichenko

    2012-12-01

    Full Text Available In the article the results of mathematical design of the system of electric traction of direct current are represented in the mode of short circuit and different feed charts of fyder area: two-sided; one-sided. Comparison of transitional electric sizes which characterize electromagnetic processes during these malfunctions is analysed and executed.

  3. Short-circuit current density imaging of crystalline silicon solar cells via lock-in thermography: Robustness and simplifications

    International Nuclear Information System (INIS)

    Fertig, Fabian; Greulich, Johannes; Rein, Stefan

    2014-01-01

    Spatially resolved determination of solar cell parameters is beneficial for loss analysis and optimization of conversion efficiency. One key parameter that has been challenging to access by an imaging technique on solar cell level is short-circuit current density. This work discusses the robustness of a recently suggested approach to determine short-circuit current density spatially resolved based on a series of lock-in thermography images and options for a simplified image acquisition procedure. For an accurate result, one or two emissivity-corrected illuminated lock-in thermography images and one dark lock-in thermography image have to be recorded. The dark lock-in thermography image can be omitted if local shunts are negligible. Furthermore, it is shown that omitting the correction of lock-in thermography images for local emissivity variations only leads to minor distortions for standard silicon solar cells. Hence, adequate acquisition of one image only is sufficient to generate a meaningful map of short-circuit current density. Beyond that, this work illustrates the underlying physics of the recently proposed method and demonstrates its robustness concerning varying excitation conditions and locally increased series resistance. Experimentally gained short-circuit current density images are validated for monochromatic illumination in comparison to the reference method of light-beam induced current

  4. Towards behavioral synthesis of asynchronous circuits - an implementation template targeting syntax directed compilation

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Sparsø, Jens; Madsen, Jan

    2004-01-01

    This paper presents a method for behavioral synthesis of asynchronous circuits. Our approach aims at providing a synthesis flow which is very similar to what is found in existing synchronous design tools. We adapt the synchronous behavioral synthesis abstraction into the asynchronous handshake...

  5. Fission and corrosion products behavior in primary circuits of LMFBR's

    International Nuclear Information System (INIS)

    Feuerstein, H.; Thorley, A.W.

    1987-08-01

    Most of the 20 presented papers report items belonging to more than one session. The equipment results of primary circuits of LMFBR's relative to corrosion and fission products, release and chemistry of fuel, measurement techniques and analytical procedures of sodium sampling, difficulties with radionuclides and particles, reactor experiences with EBR-II, FFTF, BR10, BOR60, BN350, BN600, JOYO, and KNK-II, DFR, PFR, RAPSODIE, PHENIX, and SUPERPHENIX, and at least the verification of codes for calculation models of radioactive products accumulation and distribution are described. All 20 papers presented at the meeting are separately indexed in the database. (DG)

  6. Consequences and mitigation of saltwater intrusion induced by short-circuiting during aquifer storage and recovery in a coastal subsurface

    Science.gov (United States)

    Gerardus Zuurbier, Koen; Stuyfzand, Pieter Jan

    2017-02-01

    Coastal aquifers and the deeper subsurface are increasingly exploited. The accompanying perforation of the subsurface for those purposes has increased the risk of short-circuiting of originally separated aquifers. This study shows how this short-circuiting negatively impacts the freshwater recovery efficiency (RE) during aquifer storage and recovery (ASR) in coastal aquifers. ASR was applied in a shallow saltwater aquifer overlying a deeper, confined saltwater aquifer, which was targeted for seasonal aquifer thermal energy storage (ATES). Although both aquifers were considered properly separated (i.e., a continuous clay layer prevented rapid groundwater flow between both aquifers), intrusion of deeper saltwater into the shallower aquifer quickly terminated the freshwater recovery. The presumable pathway was a nearby ATES borehole. This finding was supported by field measurements, hydrochemical analyses, and variable-density solute transport modeling (SEAWAT version 4; Langevin et al., 2007). The potentially rapid short-circuiting during storage and recovery can reduce the RE of ASR to null. When limited mixing with ambient groundwater is allowed, a linear RE decrease by short-circuiting with increasing distance from the ASR well within the radius of the injected ASR bubble was observed. Interception of deep short-circuiting water can mitigate the observed RE decrease, although complete compensation of the RE decrease will generally be unattainable. Brackish water upconing from the underlying aquitard towards the shallow recovery wells of the ASR system with multiple partially penetrating wells (MPPW-ASR) was observed. This leakage may lead to a lower recovery efficiency than based on current ASR performance estimations.

  7. Effect of dislocations on the open-circuit voltage, short-circuit current and efficiency of heteroepitaxial indium phosphide solar cells

    Science.gov (United States)

    Jain, Raj K.; Flood, Dennis J.

    1990-01-01

    Excellent radiation resistance of indium phosphide solar cells makes them a promising candidate for space power applications, but the present high cost of starting substrates may inhibit their large scale use. Thin film indium phosphide cells grown on Si or GaAs substrates have exhibited low efficiencies, because of the generation and propagation of large number of dislocations. Dislocation densities were calculated and its influence on the open circuit voltage, short circuit current, and efficiency of heteroepitaxial indium phosphide cells was studied using the PC-1D. Dislocations act as predominant recombination centers and are required to be controlled by proper transition layers and improved growth techniques. It is shown that heteroepitaxial grown cells could achieve efficiencies in excess of 18 percent AMO by controlling the number of dislocations. The effect of emitter thickness and surface recombination velocity on the cell performance parameters vs. dislocation density is also studied.

  8. Optical effects of shadow masks on short circuit current of organic photovoltaic devices.

    Science.gov (United States)

    Lin, Chi-Feng; Lin, Bing-Hong; Liu, Shun-Wei; Hsu, Wei-Feng; Zhang, Mi; Chiu, Tien-Lung; Wei, Mau-Kuo; Lee, Jiun-Haw

    2012-03-21

    In this paper, we have employed different shadow masks attached on top of organic photovoltaic (OPV) devices to study the optical effects of the former on the short circuit current (J(SC)). To rule out possible lateral electrical conduction and simplify the optical effects inside the device, a small-molecular heterojunction OPV device with a clear donor/acceptor interface was employed with a hole extraction layer exhibiting high resistance intentionally. Careful calibration with a shadow mask was employed. By attaching two layers of opaque masks in combination with a suitable holder design to shield the light from the edges and backside, the value of J(SC) approached that of the dark current, even under 1-sun radiation. With different illumination areas, we found that the photons illuminating the non-active region of the device contributed to 40% of the J(SC) by optical effect within the width of about 1 mm around the active region. When illuminating the non-active area with 12 mm to the active area, a 5.6 times improvement in the J(SC) was observed when the incident angle was 75°. With the introduction of a microstructured film onto the OPV device and an increase in the reflection from the non-active region, a 15% enhancement of the J(SC) compared to the control device was achieved.

  9. Solar Cell Short Circuit Current Errors and Uncertainties During High Altitude Calibrations

    Science.gov (United States)

    Snyder, David D.

    2012-01-01

    High altitude balloon based facilities can make solar cell calibration measurements above 99.5% of the atmosphere to use for adjusting laboratory solar simulators. While close to on-orbit illumination, the small attenuation to the spectra may result in under measurements of solar cell parameters. Variations of stratospheric weather, may produce flight-to-flight measurement variations. To support the NSCAP effort, this work quantifies some of the effects on solar cell short circuit current (Isc) measurements on triple junction sub-cells. This work looks at several types of high altitude methods, direct high altitude meas urements near 120 kft, and lower stratospheric Langley plots from aircraft. It also looks at Langley extrapolation from altitudes above most of the ozone, for potential small balloon payloads. A convolution of the sub-cell spectral response with the standard solar spectrum modified by several absorption processes is used to determine the relative change from AMO, lscllsc(AMO). Rayleigh scattering, molecular scatterin g from uniformly mixed gases, Ozone, and water vapor, are included in this analysis. A range of atmosph eric pressures are examined, from 0. 05 to 0.25 Atm to cover the range of atmospheric altitudes where solar cell calibrations a reperformed. Generally these errors and uncertainties are less than 0.2%

  10. Investigation of Permanent Magnet Demagnetization in Synchronous Machines during Multiple Short-Circuit Fault Conditions

    Directory of Open Access Journals (Sweden)

    Stefan Sjökvist

    2017-10-01

    Full Text Available Faults in electrical machines can vary in severity and affect different parts of the machine. This study focuses on various kinds of short-circuits on the terminal side of a generic 20 kW surface mounted permanent magnet synchronous generator and how successive faults affect the performance of the machine. The study was conducted with the commercially available finite element method software COMSOL Multiphysics ® , and two time-dependent models for demagnetization of permanent magnets were compared, one using only internal models and the other using a proprietary external function. The study is simulation based and the two models were compared to a previously experimentally verified stationary model. Results showed that the power output decreased by more than 30% after five successive faults. In addition, the no-load voltage had become unsymmetrical, which was explained by the uneven demagnetization of the permanent magnets. The permanent magnet with the lowest reduction in average remanence was decreased by 0.8%, while the highest average reduction was 23.8% in another permanent magnet. The internal simulation model was about four times faster than the external model, but slightly overestimated the demagnetization.

  11. On the short distance behavior of string theories

    International Nuclear Information System (INIS)

    Guida, R.; Konishi, K.; Provero, P.

    1991-01-01

    Short distance behavior of string theories is investigated by the use of the discretized path-integral formulation. In particular, the minimum physical length and the generalized uncertainty relation are re-derived from a set of Ward-Takahashi identities. In this paper several issues related to the form of the generalized uncertainty relation and to its implications are discussed. A consistent qualitative picture of short distance behavior of string theory seems to emerge from such a study

  12. Investigation and Classification of Short-Circuit Failure Modes Based on Three-Dimensional Safe Operating Area for High-Power IGBT Modules

    DEFF Research Database (Denmark)

    Chen, Yuxiang; Li, Wuhua; Iannuzzo, Francesco

    2018-01-01

    is implemented to motivate advanced contributions in future dependence research of device short-circuit failure modes on temperature. Consequently, a comprehensive and thoughtful review of where the development of short-circuit failure mode research works of IGBT stands and is heading is provided....

  13. The short-circuit test results of 6.9 kV/2.3 kV 400 kVA-class YBCO model transformer

    International Nuclear Information System (INIS)

    Tomioka, A.; Otonari, T.; Ogata, T.; Iwakuma, M.; Okamoto, H.; Hayashi, H.; Iijima, Y.; Saito, T.; Gosho, Y.; Tanabe, K.; Izumi, T.; Shiohara, Y.

    2011-01-01

    The 6.9 kV/2.3 kV 400 kVA-class single-phase YBCO model transformer with the YBCO tape with copper tape was manufactured for short-circuit current test. Short-circuit test was performed and the short-circuit current of primary winding was 346 A which was about six times larger than the rated current. The I-V characteristics of the winding did not change before and after the test. The transformer withstood short-circuit current. We are planning to turn the result into a consideration of a 66 kV/6.9 kV-20 MVA-class three-phase superconducting transformer. We are developing an elemental technology for 66 kV/6.9 kV 20 MVA-class power transformer with YBCO conductors. The protection of short-circuit technology is one of the elemental technologies for HTS transformer. Since short-circuit current is much higher than critical current of YBCO tape, there is a possibility that superconducting characteristics may be damaged during short-circuit period. We made a conductor to compose the YBCO tape with copper tape. We manufactured 6.9 kV/2.3 kV 400 kVA-class YBCO model transformer using this conductor and performed short-circuit current test. The short-circuit current of primary winding was 346 A which was about six times larger than the rated current. The I-V characteristics of the winding did not change before and after the test. We may consider this conductor withstands short-circuit current.

  14. Detection of inter-turn short-circuit at start-up of induction machine based on torque analysis

    Directory of Open Access Journals (Sweden)

    Pietrowski Wojciech

    2017-12-01

    Full Text Available Recently, interest in new diagnostics methods in a field of induction machines was observed. Research presented in the paper shows the diagnostics of induction machine based on torque pulsation, under inter-turn short-circuit, during start-up of a machine. In the paper three numerical techniques were used: finite element analysis, signal analysis and artificial neural networks (ANN. The elaborated numerical model of faulty machine consists of field, circuit and motion equations. Voltage excited supply allowed to determine the torque waveform during start-up. The inter-turn short-circuit was treated as a galvanic connection between two points of the stator winding. The waveforms were calculated for different amounts of shorted-turns from 0 to 55. Due to the non-stationary waveforms a wavelet packet decomposition was used to perform an analysis of the torque. The obtained results of analysis were used as input vector for ANN. The response of the neural network was the number of shorted-turns in the stator winding. Special attention was paid to compare response of general regression neural network (GRNN and multi-layer perceptron neural network (MLP. Based on the results of the research, the efficiency of the developed algorithm can be inferred.

  15. Benefits of Compression Garments Worn During Handball-Specific Circuit on Short-Term Fatigue in Professional Players.

    Science.gov (United States)

    Ravier, Gilles; Bouzigon, Romain; Beliard, Samuel; Tordi, Nicolas; Grappe, Frederic

    2018-04-04

    Ravier, G, Bouzigon, R, Beliard, S, Tordi, N, and Grappe, F. Benefits of compression garments worn during handball-specific circuit on short-term fatigue in professional players. J Strength Cond Res XX(X): 000-000, 2016-The purpose of this study was to investigate the benefits of full-leg length compression garments (CGs) worn during a handball-specific circuit exercises on athletic performance and acute fatigue-induced changes in strength and muscle soreness in professional handball players. Eighteen men (mean ± SD: age 23.22 ± 4.97 years; body mass: 82.06 ± 9.69 kg; height: 184.61 ± 4.78 cm) completed 2 identical sessions either wearing regular gym short or CGs in a randomized crossover design. Exercise circuits of explosive activities included 3 periods of 12 minutes of sprints, jumps, and agility drills every 25 seconds. Before, immediately after and 24 hours postexercise, maximal voluntary knee extension (maximal voluntary contraction, MVC), rate of force development (RFD), and muscle soreness were assessed. During the handball-specific circuit sprint and jump performances were unchanged in both conditions. Immediately after performing the circuit exercises MVC, RFD, and PPT decreased significantly compared with preexercise with CGs and noncompression clothes. Decrement was similar in both conditions for RFD (effect size, ES = 0.40) and PPT for the soleus (ES = 0.86). However, wearing CGs attenuated decrement in MVC (p handball-specific circuit provides benefits on the impairment of the maximal muscle force characteristics and is likely to be worthwhile for handball players involved in activities such as tackles.

  16. Interaction of ultrashort laser pulses and silicon solar cells under short circuit conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mundus, M., E-mail: markus.mundus@ise.fraunhofer.de; Giesecke, J. A.; Fischer, P.; Hohl-Ebinger, J.; Warta, W. [Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstraße 2, 79110 Freiburg (Germany)

    2015-02-28

    Ultrashort pulse lasers are promising tools for numerous measurement purposes. Among other benefits their high peak powers allow for efficient generation of wavelengths in broad spectral ranges and at spectral powers that are orders of magnitude higher than in conventional light sources. Very recently this has been exploited for the establishment of sophisticated measurement facilities for electrical characterization of photovoltaic (PV) devices. As the high peak powers of ultrashort pulses promote nonlinear optical effects they might also give rise to nonlinear interactions with the devices under test that possibly manipulate the measurement outcome. In this paper, we present a comprehensive theoretical and experimental study of the nonlinearities affecting short circuit current (I{sub SC}) measurements of silicon (Si) solar cells. We derive a set of coupled differential equations describing the radiation-device interaction and discuss the nonlinearities incorporated in those. By a semi-analytical approach introducing a quasi-steady-state approximation and integrating a Green's function we solve the system of equations and obtain simulated I{sub SC} values. We validate the theoretical model by I{sub SC} ratios obtained from a double ring resonator setup capable for reproducible generation of various ultrashort pulse trains. Finally, we apply the model to conduct the most prominent comparison of I{sub SC} generated by ultrashort pulses versus continuous illumination. We conclude by the important finding that the nonlinearities induced by ultrashort pulses are negligible for the most common I{sub SC} measurements. However, we also find that more specialized measurements (e.g., of concentrating PV or Si-multijunction devices as well as highly localized electrical characterizations) will be biased by two-photon-absorption distorting the I{sub SC} measurement.

  17. Vasotocin- and mesotocin-induced increases in short-circuit current across tree frog skin.

    Science.gov (United States)

    Takada, Makoto; Fujimaki-Aoba, Kayo; Hokari, Shigeru

    2011-02-01

    In adult amphibian skin, Na(+) crosses from outside to inside. This Na(+) transport can be measured as the amiloride-blockable short-circuit current (SCC) across the skin. We investigated the effects of arginine vasotocin (AVT) and mesotocin (MT), and those of antagonists of the vasopressin and oxytocin receptors, on the SCC across Hyla japonica skin. (1) Both AVT (100 pmol/L or more) and MT (1 nmol/L or more) increased the SCC. (2) The AVT- and MT-induced increases in SCC recovered with time (downregulation). (3) These AVT/MT-induced effects were blocked by application of OPC-31260 (vasopressin V(2)-receptor antagonist). (4) The OPC-31260 concentration needed to block the AVT-induced response was lower upon post-application (after application of agonist) than upon pre-application (before application of agonist), suggesting the number of receptors may have decreased after AVT application. (5) Upon repeated application of AVT (100 pmol/L), the induced SCC increase did not differ significantly between the 1st and 2nd applications. (6) The time to reach the half-maximum value of the AVT-induced or MT-induced increase in SCC was not significantly different between washout and post-application of OPC-31260, suggesting that post-application of OPC-31260 cleared AVT and MT from their receptors. The effects of AVT, MT, and their antagonists in H. japonica, which is adapted to a terrestrial habitat, are compared with our previously published data on Rana catesbeiana (=Lithobates catesbeianus), which is adapted to a semiaquatic habitat.

  18. cAMP Stimulates Transepithelial Short-Circuit Current and Fluid Transport Across Porcine Ciliary Epithelium.

    Science.gov (United States)

    Cheng, Angela King-Wah; Civan, Mortimer M; To, Chi-Ho; Do, Chi-Wai

    2016-12-01

    To investigate the effects of cAMP on transepithelial electrical parameters and fluid transport across porcine ciliary epithelium. Transepithelial electrical parameters were determined by mounting freshly isolated porcine ciliary epithelium in a modified Ussing chamber. Similarly, fluid movement across intact ciliary body was measured with a custom-made fluid flow chamber. Addition of 1, 10, and 100 μM 8-Br-cAMP (cAMP) to the aqueous side (nonpigmented ciliary epithelium, NPE) induced a sustained increase in short-circuit current (Isc). Addition of niflumic acid (NFA) to the aqueous surface effectively blocked the cAMP-induced Isc stimulation. The administration of cAMP to the stromal side (pigmented ciliary epithelium, PE) triggered a significant stimulation of Isc only at 100 μM. No additive effect was observed with bilateral application of cAMP. Likewise, forskolin caused a significant stimulation of Isc when applied to the aqueous side. Concomitantly, cAMP and forskolin increased fluid transport across porcine ciliary epithelium, and this stimulation was effectively inhibited by aqueous NFA. Depleting Cl- in the bathing solution abolished the baseline Isc and inhibited the subsequent stimulation by cAMP. Pretreatment with protein kinase A (PKA) blockers (H89/KT5720) significantly inhibited the cAMP- and forskolin-induced Isc responses. Our results suggest that cAMP triggers a sustained stimulation of Cl- and fluid transport across porcine ciliary epithelium; Cl- channels in the NPE cells are potentially a cellular site for this PKA-sensitive cAMP-mediated response.

  19. Behavior of stainless steels in pressurized water reactor primary circuits

    International Nuclear Information System (INIS)

    Féron, D.; Herms, E.; Tanguy, B.

    2012-01-01

    Stainless steels are widely used in primary circuits of pressurized water reactors (PWRs). Operating experience with the various grades of stainless steels over several decades of years has generally been excellent. Nevertheless, stress corrosion failures have been reported in few cases. Two main factors contributing to SCC susceptibility enhancement are investigated in this study: cold work and irradiation. Irradiation is involved in the stress corrosion cracking and corrosion of in-core reactor components in PWR environment. Irradiated assisted stress corrosion cracking (IASCC) is a complex and multi-physics phenomenon for which a predictive modeling able to describe initiation and/or propagation is not yet achieved. Experimentally, development of initiation smart tests and of in situ instrumentation, also in nuclear reactors, is an important axis in order to gain a better understanding of IASCC kinetics. A strong susceptibility for SCC of heavily cold worked austenitic stainless steels is evidenced in hydrogenated primary water typical of PWRs. It is shown that for a given cold-working procedure, SCC susceptibility of austenitic stainless steels materials increases with increasing cold-work. Results have shown also strong influences of the cold work on the oxide layer composition and of the maximum stress on the time to fracture.

  20. Frank Beach Award Winner: Steroids as Neuromodulators of Brain Circuits and Behavior

    Science.gov (United States)

    Remage-Healey, Luke

    2014-01-01

    Neurons communicate primarily via action potentials that transmit information on the timescale of milliseconds. Neurons also integrate information via alterations in gene transcription and protein translation that are sustained for hours to days after initiation. Positioned between these two signaling timescales are the minute-by-minute actions of neuromodulators. Over the course of minutes, the classical neuromodulators (such as serotonin, dopamine, octopamine, and norepinephrine) can alter and/or stabilize neural circuit patterning as well as behavioral states. Neuromodulators allow many flexible outputs from neural circuits and can encode information content into the firing state of neural networks. The idea that steroid molecules can operate as genuine behavioral neuromodulators - synthesized by and acting within brain circuits on a minute-by-minute timescale - has gained traction in recent years. Evidence for brain steroid synthesis at synaptic terminals has converged with evidence for the rapid actions of brain-derived steroids on neural circuits and behavior. The general principle emerging from this work is that the production of steroid hormones within brain circuits can alter their functional connectivity and shift sensory representations by enhancing their information coding. Steroids produced in the brain can therefore change the information content of neuronal networks to rapidly modulate sensory experience and sensorimotor functions. PMID:25110187

  1. Analog Circuit Design Low Voltage Low Power; Short Range Wireless Front-Ends; Power Management and DC-DC

    CERN Document Server

    Roermund, Arthur; Baschirotto, Andrea

    2012-01-01

    The book contains the contribution of 18 tutorials of the 20th workshop on Advances in Analog Circuit Design.  Each part discusses a specific to-date topic on new and valuable design ideas in the area of analog circuit design. Each part is presented by six experts in that field and state of the art information is shared and overviewed. This book is number 20 in this successful series of Analog Circuit Design, providing valuable information and excellent overviews of Low-Voltage Low-Power Data Converters - Chaired by Prof. Anderea Baschirotto, University of Milan-Bicocca Short Range Wireless Front-Ends - Chaired by Prof. Arthur van Roermund, Eindhoven University of Technology Power management and DC-DC - Chaired by Prof. M. Steyaert, Katholieke University Leuven Analog Circuit Design is an essential reference source for analog circuit designers and researchers wishing to keep abreast with the latest development in the field. The tutorial coverage also makes it suitable for use in an advanced design.

  2. Homology and homoplasy of swimming behaviors and neural circuits in the Nudipleura (Mollusca, Gastropoda, Opisthobranchia)

    Science.gov (United States)

    Newcomb, James M.; Sakurai, Akira; Lillvis, Joshua L.; Gunaratne, Charuni A.; Katz, Paul S.

    2012-01-01

    How neural circuit evolution relates to behavioral evolution is not well understood. Here the relationship between neural circuits and behavior is explored with respect to the swimming behaviors of the Nudipleura (Mollusca, Gastropoda, Opithobranchia). Nudipleura is a diverse monophyletic clade of sea slugs among which only a small percentage of species can swim. Swimming falls into a limited number of categories, the most prevalent of which are rhythmic left–right body flexions (LR) and rhythmic dorsal–ventral body flexions (DV). The phylogenetic distribution of these behaviors suggests a high degree of homoplasy. The central pattern generator (CPG) underlying DV swimming has been well characterized in Tritonia diomedea and in Pleurobranchaea californica. The CPG for LR swimming has been elucidated in Melibe leonina and Dendronotus iris, which are more closely related. The CPGs for the categorically distinct DV and LR swimming behaviors consist of nonoverlapping sets of homologous identified neurons, whereas the categorically similar behaviors share some homologous identified neurons, although the exact composition of neurons and synapses in the neural circuits differ. The roles played by homologous identified neurons in categorically distinct behaviors differ. However, homologous identified neurons also play different roles even in the swim CPGs of the two LR swimming species. Individual neurons can be multifunctional within a species. Some of those functions are shared across species, whereas others are not. The pattern of use and reuse of homologous neurons in various forms of swimming and other behaviors further demonstrates that the composition of neural circuits influences the evolution of behaviors. PMID:22723353

  3. Short-circuit tests of 1650 and 96 MVA transformers for 1300 MW french nuclear power plants

    International Nuclear Information System (INIS)

    Mailhot, M.

    1989-01-01

    Power evacuation and feeding of the auxiliaries directly from the 400 kV grid are sensitive points governing the security of 1300 MW PWR Nuclear Power Plants of the French Program. These two different functions are provided by two specific types of transformers. - Banks of 3 single-phase 550 MVA - 400 kV/20 kV transformers. - Three-phase 96 MVA - 400 kV / 3 x 6.8 kV transformers. These passive elements must have a never failing reliability and assure a continuous service in spite of electric, thermal and mechanical stresses that may occur during the lifetime of the power plant. Dielectric and thermal tests carried out in the manufacturers test floors insure these stresses withstand capabilities of transformers. In France, high short-circuit power for the 400 kV network added to often low impedance voltages for transformers impose on them very high stresses during short-circuits. Calculation and experimentation on scale or partial models are not sufficient to insure short-circuit currents withstand capabilities of transformers. The margin of uncertainty dependent on obligatory extrapolations for this kind of complex systems [steel, magnetic sheets, copper, oil, paper and transformerboard] can be reduced in a significant way only by real scale tests on prototypes. These tests that need both high power and voltage cannot be performed in manufacturers test floors. So, in France they are carried out at the EDF Les Renardieres Laboratory. Following paper deals with SHELL TYPE TRANSFORMERS which, particularly thanks to their interleaved rectangular windings display a great resistance to short-circuit stresses

  4. Extra-high short-circuit current for bifacial solar cells in sunny and dark-light conditions.

    Science.gov (United States)

    Duan, Jialong; Duan, Yanyan; Zhao, Yuanyuan; He, Benlin; Tang, Qunwei

    2017-09-05

    We present here a symmetrically structured bifacial solar cell tailored by two fluorescent photoanodes and a platinum/titanium/platinum counter electrode, yielding extra-high short-circuit current densities as high as 28.59 mA cm -2 and 119.9 μA cm -2 in simulated sunlight irradiation (100 mW cm -2 , AM1.5) and dark-light conditions, respectively.

  5. Striatal fast-spiking interneurons selectively modulate circuit output and are required for habitual behavior.

    Science.gov (United States)

    O'Hare, Justin K; Li, Haofang; Kim, Namsoo; Gaidis, Erin; Ade, Kristen; Beck, Jeff; Yin, Henry; Calakos, Nicole

    2017-09-05

    Habit formation is a behavioral adaptation that automates routine actions. Habitual behavior correlates with broad reconfigurations of dorsolateral striatal (DLS) circuit properties that increase gain and shift pathway timing. The mechanism(s) for these circuit adaptations are unknown and could be responsible for habitual behavior. Here we find that a single class of interneuron, fast-spiking interneurons (FSIs), modulates all of these habit-predictive properties. Consistent with a role in habits, FSIs are more excitable in habitual mice compared to goal-directed and acute chemogenetic inhibition of FSIs in DLS prevents the expression of habitual lever pressing. In vivo recordings further reveal a previously unappreciated selective modulation of SPNs based on their firing patterns; FSIs inhibit most SPNs but paradoxically promote the activity of a subset displaying high fractions of gamma-frequency spiking. These results establish a microcircuit mechanism for habits and provide a new example of how interneurons mediate experience-dependent behavior.

  6. Double-layer rotor magnetic shield performance analysis in high temperature superconducting synchronous generators under short circuit fault conditions

    Science.gov (United States)

    Hekmati, Arsalan; Aliahmadi, Mehdi

    2016-12-01

    High temperature superconducting, HTS, synchronous machines benefit from a rotor magnetic shield in order to protect superconducting coils against asynchronous magnetic fields. This magnetic shield, however, suffers from exerted Lorentz forces generated in light of induced eddy currents during transient conditions, e.g. stator windings short-circuit fault. In addition, to the exerted electromagnetic forces, eddy current losses and the associated effects on the cryogenic system are the other consequences of shielding HTS coils. This study aims at investigating the Rotor Magnetic Shield, RMS, performance in HTS synchronous generators under stator winding short-circuit fault conditions. The induced eddy currents in different circumferential positions of the rotor magnetic shield along with associated Joule heating losses would be studied using 2-D time-stepping Finite Element Analysis, FEA. The investigation of Lorentz forces exerted on the magnetic shield during transient conditions has also been performed in this paper. The obtained results show that double line-to-ground fault is of the most importance among different types of short-circuit faults. It was revealed that when it comes to the design of the rotor magnetic shields, in addition to the eddy current distribution and the associated ohmic losses, two phase-to-ground fault should be taken into account since the produced electromagnetic forces in the time of fault conditions are more severe during double line-to-ground fault.

  7. Determination of short circuit stresses in an air core reactor using ...

    African Journals Online (AJOL)

    DR OKE

    developed has crossed the boundary condition limit of 70 MPa whereas the ... The method can be used to identify the inter layer forces ... Power transformer design using magnetic circuit theory and finite element analysis – A Comparison.

  8. Effect of cAMP on short-circuit current in isolated human ciliary body.

    Science.gov (United States)

    Wu, Ren-yi; Ma, Ning; Hu, Qian-qian

    2013-07-01

    Cyclic adenosine monophosphate (cAMP) could activate chloride channels in bovine ciliary body and trigger an increase in the ionic current (short-circuit current, Isc) across the ciliary processes in pigs. The purpose of this study was to investigate how cAMP modulates Isc in isolated human ciliary processes and the possible involvement of chloride transport across the tissue in cAMP-induced Isc change. In an Ussing-type chamber system, the Isc changes induced by the cAMP analogue 8-bromo-cAMP and an adenylyl cyclase activator forskolin in isolated human ciliary processes were assessed. The involvement of Cl(-) component in the bath solution was investigated. The effect of Cl(-) channel (10 µmol/L niflumic acid and 1 mmol/L 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS)), K(+) channel (10 mmol/L tetraethylammonium chloride (TEA)), or Na(+) channel blockers (1 mmol/L amiloride) on 8-bromo-cAMP-induced Isc change was also studied. Dose-dependently, 8-bromo-cAMP (10 nmol/L-30 µmol/L) or forskolin (10 nmol/L-3 µmol/L) increased Isc across the ciliary processes with an increase in negative potential difference on the non-pigmented epithelium (NPE) side of the tissue. Isc increase induced by 8-bromo-cAMP was more pronounced when the drug was applied on the NPE side than on the pigmented epithelium side. When the tissue was bathed in low Cl(-) solutions, the Isc increase was significantly inhibited. Finally, niflumic acid and DIDS, but not TEA or amiloride, significantly prevented the Isc increase induced by 8-bromo-cAMP. cAMP stimulates stroma-to-aqueous anionic transport in isolated human ciliary processes. Chloride is likely to be among the ions, the transportation of which across the tissue is triggered by cAMP, suggesting the potential role of cAMP in the process of aqueous humor formation in human eyes.

  9. The dependence of the short circuit current with γ-radiation in CuGaSe2

    International Nuclear Information System (INIS)

    Gasimoglu, I.; Mamedova, I.A.; Bagirov, A.G.

    2005-01-01

    Full text: The A I B III C IV semiconducting compounds are of interest for semiconducting devising. In particular the presence of the birefringence makes the compounds as a perspective materials for using in nonlinear optical transformers. Besides, the complex generation-recombination processes in these compounds are due to the local states in the band gap, which is also due to the complex chemical structure of these compounds. In this report the results of the influence of γ-radiation on the short circuit current in CuGaSe 2 are presented. The Co 6 0 with the quantum energy of 1.25 MeV was a source of radiation. The resistance was 10 2 kΩ at 300 K. The In-Ga eutectic was used as a contact. The measurements have been carried out at 77 K. The electrometer B7-30 was used for the short circuit current measurements, sensitivity of which is 10 -15 A. The intensity of γ-rays was 20 R/s, durability of radiation was 15 min. The spectrometer SPM-2 was used as a source of radiation of monoxrmator light. The spectral dependence of short circuit current of non radiated CuGaSe 2 crystal has a maximum at λ=700 nm (0.77 eV) with the half width of 0.26 eV. The maximum of short circuit current is in good agreement with the value 1.8 eV at 300 K. That is why one can assume that observed peak in J sc ∼∼f(λ) dependence with the maximum at 1.77 eV is due to electronic transitions from the valence band to conduction band. After radiation of CuGaSe 2 crystal new maximum is observed in the spectral dependence of short circuit current at λ=770 nm (1.61 eV) at 77 K. Splitting between the peaks is 0.13 eV. The appearance of the second peak maybe is due to the formation of radiation defects of acceptor type, which are located for 0.13 eV above than the top of valence band. The peak at 1.59 eV, which is due the donor-acceptor recombination, is observed in photoluminescence spectra. It is assumed that, Se vacancy forms the donor levels, Cu vacancy -acceptor levels

  10. THE RELIABILITY OF DETERMINING THE SHORT CIRCUIT ZONE OF THE LINES OF 6–35 kV

    Directory of Open Access Journals (Sweden)

    F. А. Romaniuk

    2018-01-01

    Full Text Available A method of increasing the reliability of determining the zone of short-circuit at the current step protection of the lines of 6–35 kV with unilateral power, aimed at improvement of their technical perfection, is presented in the paper. Having taken the relative simpleness of the current protection into account the authors consider the unilateral remote method of accounting the parameters of the emergency mode and the type of fault to be the most suitable for the implementation of the algorithm of its functioning as compared with the existing methods of fault location. The major factors affecting the accuracy of determining the short circuit zone based on the remote method are noted. With the use of the method of computational experiment the influence of the load currents and contact resistances of various levels on the magnitude and character of changes of errors of determination of the calculated distance of the point of fault from the protection installation location taking into account the errors of measuring transformers. It is demonstrated that in many cases of arc short circuit in a loaded line in order to define the zone of short-circuit with fair accuracy correction of the estimated distance to the fault as calculated by the parameters of the damaged loop (loops is required. According to the results of numerical experiments corrective expressions on the basis of two relative asymmetry currents determined by the current values of the differences of the phase currents of the line for detecting a type of a short circuit have been obtained. The assessment of the efficiency of the proposed method has been performed. It is shown that the application of the proposed correction method makes it possible to increase the accuracy of fault zone detection. The dynamic properties of the proposed method applied to different modes of the line functioning have been studied. It is determined that in the worst case the definition of the fault zone for a

  11. Electromechanical stress in transformers caused by three-phase short-circuits; Estresse eletromecanico em transformadores causado por curtos-circuitos trifasicos

    Energy Technology Data Exchange (ETDEWEB)

    Rosentino, A.J.J. Pereira; Delaiba, A.C.; Saraiva, E.; Oliveira, J.C. de; Lynce, M. [Universidade Federal de Uberlandia (UFU), MG (Brazil). Fac. de Engenharia Eletrica], Emails: arnaldoufu@gmail.com, delaiba@ufu.br, elise.saraiva@yahoo.com.br, jcoliveira@ufu.br, lynce@ufu.br; Bronzeado, H. de S. [Companhia Hidro Eletrica do Sao Francisco (CHESF), Recife, PE (Brazil)], Emails: herivelto.bronzeado@gmail.com, hebron@chesf.gov.br

    2009-07-01

    One of the reasons for internal failures of transformers is the weakness of the isolation of its conductors/coils due to vibrations caused by electromechanics forces produced by the high short-circuit currents. In this context, this paper presents a methodology to estimate the electromechanical stress in transformers caused by three-phase short circuits. Details of the characteristics of radial and axial forces that can occur in concentric windings of transformers, focusing mainly on the axial are presented. It is presented the preliminary description of techniques for diagnosis and monitoring of transformers in the face of mechanical stress caused by short circuit. This study considers the transformers core involved.

  12. Various mechanisms and clinical phenotypes in electrical short circuits of high-voltage devices: report of four cases and review of the literature.

    Science.gov (United States)

    Tsurugi, Takuo; Matsui, Shogo; Nakajima, Hiroshi; Nishii, Nobuhiro; Honda, Toshihiro; Kaneko, Yoshiaki

    2015-06-01

    An electrical short circuit is a rare complication in a high-voltage implantable cardioverter-defibrillator (ICD). However, the inability of an ICD to deliver appropriate shock therapy can be life-threatening. During the last 2 years, four cases of serious complications related to an electrical short circuit have been reported in Japan. A spark due to an electrical short circuit resulted in the failure of an ICD shock to terminate ventricular tachycardia and total damage to the ICD generator in three of four cases. Two of the four patients died from an electrical short circuit between the right ventricle and superior vena cava (SVC) leads. The others had audible sounds from the ICD generator site and were diagnosed with a lead-to-can abrasion, which was manifested by the arc mark on the surface of the can. It is still difficult to predict the occurrence of an electrical short circuit in current ICD systems. To reduce the probability of an electrical short circuit, we suggest the following: (i) avoid lead stress at ICD implantation, (ii) select a single-coil lead instead of a dual-coil lead, or (iii) use a unique algorithm which automatically disconnect can or SVC lead from shock deliver circuit when excessive current was detected. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  13. Study on Oscillations during Short Circuit of MW-Scale IGBT Power Modules by Means of a 6-kA/1.1-kV Nondestructive Testing System

    DEFF Research Database (Denmark)

    Wu, Rui; Diaz Reigosa, Paula; Iannuzzo, Francesco

    2015-01-01

    This paper uses a 6-kA/1.1-kV nondestructive testing system for the analysis of the short-circuit behavior of insulated-gate bipolar transistor (IGBT) power modules. A field-programmable gate array enables the definition of control signals to an accuracy of 10 ns. Multiple 1.7-kV/1-kA IGBT power...... modules displayed severe divergent oscillations, which were subsequently characterized. Experimental tests indicate that nonnegligible circuit stray inductance plays an important role in the divergent oscillations. In addition, the temperature dependence of the transconductance is proposed as an important...

  14. The principle of elaboration of the relay protection against short circuits between the closely placed phases of high voltage electrical line

    Directory of Open Access Journals (Sweden)

    Kiorsak M.

    2015-12-01

    Full Text Available The article is devoted to the elaboration of the principle of relay protection against short circuits between the closely placed phases of higher voltage electrical line with self-compensation, based on the six phase’s symmetrical components. It is shown that the unsymmetrical short circuits between the closely placed phases are characterized by appearance of zero and tertiary sequences of symmetrical components. This fact can be used to choose them for relay protection. The electrical basic circuits and formulas for calculation of the passive parameters of zero and tertiary filters of currents (voltages are done. It is presented the structural-functional basic circuit scheme for relay protection against short circuits between the closely placed phases of higher voltage electrical line with self-compensation.

  15. Achieving 12.8% Efficiency by Simultaneously Improving Open-Circuit Voltage and Short-Circuit Current Density in Tandem Organic Solar Cells.

    Science.gov (United States)

    Qin, Yunpeng; Chen, Yu; Cui, Yong; Zhang, Shaoqing; Yao, Huifeng; Huang, Jiang; Li, Wanning; Zheng, Zhong; Hou, Jianhui

    2017-06-01

    Tandem organic solar cells (TOSCs), which integrate multiple organic photovoltaic layers with complementary absorption in series, have been proved to be a strong contender in organic photovoltaic depending on their advantages in harvesting a greater part of the solar spectrum and more efficient photon utilization than traditional single-junction organic solar cells. However, simultaneously improving open circuit voltage (V oc ) and short current density (J sc ) is a still particularly tricky issue for highly efficient TOSCs. In this work, by employing the low-bandgap nonfullerene acceptor, IEICO, into the rear cell to extend absorption, and meanwhile introducing PBDD4T-2F into the front cell for improving V oc , an impressive efficiency of 12.8% has been achieved in well-designed TOSC. This result is also one of the highest efficiencies reported in state-of-the-art organic solar cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Design and flight performance evaluation of the Mariners 6, 7, and 9 short-circuit current, open-circuit voltage transducers

    Science.gov (United States)

    Patterson, R. E.

    1973-01-01

    The purpose of the short-circuit voltage transducer is to provide engineering data to aid the evaluation of array performance during flight. The design, fabrication, calibration, and in-flight performance of the transducers onboard the Mariner 6, 7 and 9 spacecrafts are described. No significant differences were observed in the in-flight electrical performance of the three transducers. The transducers did experience significant losses due to coverslides or adhesive darkening, increased surface reflection, or spectral shifts within coverslide assembly. Mariner 6, 7 and 9 transducers showed non-cell current degradations of 3-1/2%, 3%, and 4%, respectively at Mars encounter and 6%, 3%, and 4-12%, respectively at end of mission. Mariner 9 solar Array Test 2 showed 3-12% current degradation while the transducer showed 4-12% degradation.

  17. Inclusions and mechanical behavior in the short transverse direction

    International Nuclear Information System (INIS)

    Aubert, H.; Bouleau, M.; Laniesse, J.; Lelong, C.; Pigoury, M.

    1977-01-01

    The variables liable to characterize the distribution of inclusions in plates, and the relationships between the mechanical properties and the fatigue behavior in, on the one hand, the short transverse direction, and, on the other hand, the inclusions are studied. A decoherence is shown between inclusions and matrix as the cause of the failure by lamellar tearing [fr

  18. Laser induced non-monotonic degradation in short-circuit current of triple-junction solar cells

    Science.gov (United States)

    Dou, Peng-Cheng; Feng, Guo-Bin; Zhang, Jian-Min; Song, Ming-Ying; Zhang, Zhen; Li, Yun-Peng; Shi, Yu-Bin

    2018-06-01

    In order to study the continuous wave (CW) laser radiation effects and mechanism of GaInP/GaAs/Ge triple-junction solar cells (TJSCs), 1-on-1 mode irradiation experiments were carried out. It was found that the post-irradiation short circuit current (ISC) of the TJSCs initially decreased and then increased with increasing of irradiation laser power intensity. To explain this phenomenon, a theoretical model had been established and then verified by post-damage tests and equivalent circuit simulations. Conclusion was drawn that laser induced alterations in the surface reflection and shunt resistance were the main causes for the observed non-monotonic decrease in the ISC of the TJSCs.

  19. Spatial patterns of persistent neural activity vary with the behavioral context of short-term memory.

    Science.gov (United States)

    Daie, Kayvon; Goldman, Mark S; Aksay, Emre R F

    2015-02-18

    A short-term memory can be evoked by different inputs and control separate targets in different behavioral contexts. To address the circuit mechanisms underlying context-dependent memory function, we determined through optical imaging how memory is encoded at the whole-network level in two behavioral settings. Persistent neural activity maintaining a memory of desired eye position was imaged throughout the oculomotor integrator after saccadic or optokinetic stimulation. While eye position was encoded by the amplitude of network activity, the spatial patterns of firing were context dependent: cells located caudally generally were most persistent following saccadic input, whereas cells located rostrally were most persistent following optokinetic input. To explain these data, we computationally identified four independent modes of network activity and found these were differentially accessed by saccadic and optokinetic inputs. These results show how a circuit can simultaneously encode memory value and behavioral context, respectively, in its amplitude and spatial pattern of persistent firing. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Composite dynamical behaviors in a simple series–parallel LC circuit

    International Nuclear Information System (INIS)

    Manimehan, I.; Philominathan, P.

    2012-01-01

    Highlights: ► We have presented a simple circuit exhibiting rich dynamical behaviors. ► The detailed study of the circuit is given by two parameter bifurcation diagram. ► The numerical, analytical and experimental results are good in agreement. ► The Chosen system seems to have potential application in future. - Abstract: In this paper, we report a variety of dynamical behaviors exhibited in a compact series–parallel LC circuit system comprising of two active elements, one linear negative conductance and one ordinary junction diode with piecewise linear v − i characteristics. For convenience, we consider the amplitude (E f ) and frequency (f) of the driving force as control parameters amongst various other parameters. We observe the phenomenon of antimonotonicity, torus breakdown to chaos, bubbles to chaos, period doubling to chaos and emergence of multiple attractors which follow a progressive sequence, etc. As an overview to understand many more variety of bifurcations and attractors, the construction of two parameter phase diagram is also shown pictorially. The chaotic dynamics of this circuit is realized by laboratory experiment, numerical and analytical investigations and found that the results are in good agreement with each other.

  1. Evidence of Gate Voltage Oscillations during Short Circuit of Commercial 1.7 kV/ 1 kA IGBT Power Modules

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Wu, Rui; Iannuzzo, Francesco

    2015-01-01

    This paper analyzes the evidence of critical gate voltage oscillations in 1.7 kV/1 kA Insulated-Gate Bipolar Transistor (IGBT) power modules under short circuit conditions. A 6 kA/1.1 kV Non-Destructive Test (NDT) set up for repeatable short circuit tests has been built with a 40 nH stray inducta...

  2. Round busbar concept for 30 nH, 1.7 kV, 10 kA IGBT non-destructive short-circuit tester

    DEFF Research Database (Denmark)

    Smirnova, Liudmila; Pyrhönen, Juha; Iannuzzo, Francesco

    2014-01-01

    Design of a Non-Destructive Test (NDT) set-up for short-circuit tests of 1.7 kV, 1 kA IGBT modules is discussed in this paper. The test set-up allows achieving short-circuit current up to 10 kA. The important objective during the design of the test set-up is to minimize the parasitic inductance...

  3. New Circuits or Short Circuits?

    Science.gov (United States)

    McLaughlin, Frank

    1967-01-01

    Schools must refuse to contribute to this age of "information overload" and, through an interdisciplinary approach, assist students to become receptive to humane feelings and to understand the complexities of a culture. To these ends, educators must "re-program" the entire educational system by relinquishing their attachment to their own…

  4. Enhancement of short-circuit current density in polymer bulk heterojunction solar cells comprising plasmonic silver nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yuzhao; Lin, Xiaofeng; Ou, Jiemei; Chen, Xudong, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn [Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education of China, Sun Yat-sen University, Guangzhou 510275 (China); Qing, Jian; Zhong, Zhenfeng; Zhou, Xiang, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn; Chen, Yujie, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Hu, Chenglong [Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, Jianghan University, Wuhan 430056 (China)

    2014-03-24

    We demonstrate that the influence of plasmonic effects based on silver nanowires (Ag NWs) on the characteristics of polymer solar cells (PSCs). The solution-processed Ag NWs are situated at the interface of anode buffer layer and active layer, which could enhance the performance especially the photocurrent of PSCs by scattering, localized surface plasmon resonance, and surface plasmon polaritons. Plasmonic effects are confirmed by the enhancement of extinction spectra, external quantum efficiency, and steady state photoluminescence. Consequently, the short-circuit current density (J{sub sc}) and power conversion efficiency enhance about 24% and 18%, respectively, under AM1.5 illumination when Ag NWs plasmonic nanostructure incorporated into PSCs.

  5. A geometric approach for fault detection and isolation of stator short circuit failure in a single asynchronous machine

    KAUST Repository

    Khelouat, Samir

    2012-06-01

    This paper deals with the problem of detection and isolation of stator short-circuit failure in a single asynchronous machine using a geometric approach. After recalling the basis of the geometric approach for fault detection and isolation in nonlinear systems, we will study some structural properties which are fault detectability and isolation fault filter existence. We will then design filters for residual generation. We will consider two approaches: a two-filters structure and a single filter structure, both aiming at generating residuals which are sensitive to one fault and insensitive to the other faults. Some numerical tests will be presented to illustrate the efficiency of the method.

  6. Matlab/Simulink Implementation of Wave-based Models for Microstrip Structures utilizing Short-circuited and Opened Stubs

    Directory of Open Access Journals (Sweden)

    Biljana P. Stošić

    2011-12-01

    Full Text Available This paper describes modeling and analyzing procedures for microstrip filters based on use of one-dimensional wave digital approach. Different filter structures are observed. One filter is based on quarter-wave length short-circuited stubs and connecting transmission lines. The other one is based on cross-junction opened stubs. Frequency responses are obtained by direct analysis of the block-based networks formed in Simulink toolbox of MATLAB environment. This wave-based method allows an accurate and efficient analysis of different microwave structures.

  7. Small-bandgap polymer solar cells with unprecedented short-circuit current density and high fill factor.

    Science.gov (United States)

    Choi, Hyosung; Ko, Seo-Jin; Kim, Taehyo; Morin, Pierre-Olivier; Walker, Bright; Lee, Byoung Hoon; Leclerc, Mario; Kim, Jin Young; Heeger, Alan J

    2015-06-03

    Small-bandgap polymer solar cells (PSCs) with a thick bulk heterojunction film of 340 nm exhibit high power conversion efficiencies of 9.40% resulting from high short-circuit current density (JSC ) of 20.07 mA cm(-2) and fill factor of 0.70. This remarkable efficiency is attributed to maximized light absorption by the thick active layer and minimized recombination by the optimized lateral and vertical morphology through the processing additive. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Radial direct bandgap p-i-n GaNP microwire solar cells with enhanced short circuit current

    Energy Technology Data Exchange (ETDEWEB)

    Sukrittanon, Supanee [Graduate Program of Materials Science and Engineering, University of California, San Diego, La Jolla, California 92037 (United States); Liu, Ren; Pan, Janet L. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92037 (United States); Breeden, Michael C. [Department of Nanoengineering, University of California, San Diego, La Jolla, California 92037 (United States); Jungjohann, K. L. [Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Tu, Charles W., E-mail: ctu@ece.ucsd.edu, E-mail: sdayeh@ece.ucsd.edu; Dayeh, Shadi A., E-mail: ctu@ece.ucsd.edu, E-mail: sdayeh@ece.ucsd.edu [Graduate Program of Materials Science and Engineering, University of California, San Diego, La Jolla, California 92037 (United States); Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92037 (United States)

    2016-08-07

    We report the demonstration of dilute nitride heterostructure core/shell microwire solar cells utilizing the combination of top-down reactive-ion etching to create the cores (GaP) and molecular beam epitaxy to create the shells (GaNP). Systematic studies of cell performance over a series of microwire lengths, array periods, and microwire sidewall morphologies examined by transmission electron microscopy were conducted to shed light on performance-limiting factors and to optimize the cell efficiency. We show by microscopy and correlated external quantum efficiency characterization that the open circuit voltage is degraded primarily due to the presence of defects at the GaP/GaNP interface and in the GaNP shells, and is not limited by surface recombination. Compared to thin film solar cells in the same growth run, the microwire solar cells exhibit greater short circuit current but poorer open circuit voltage due to greater light absorption and number of defects in the microwire structure, respectively. The comprehensive understanding presented in this work suggests that performance benefits of dilute nitride microwire solar cells can be achieved by further tuning of the epitaxial quality of the underlying materials.

  9. TRANP - a computer code for digital simulation of steady - state and transient behavior of a pressurizer water reactor primary circuit

    International Nuclear Information System (INIS)

    Chalhoub, E.S.

    1980-09-01

    A digital computer code TRANP was developed to simulate the steady-state and transient behavior of a pressurizer water reactor primary circuit. The development of this code was based on the combining of three codes already developed for the simulation of a PWR core, a pressurizer, a steam generator and a main coolant pump, representing the primary circuit components. (Author) [pt

  10. Variable amplitude fatigue crack growth behavior - a short overview

    International Nuclear Information System (INIS)

    Singh, Konjengbam Darunkumar; Parry, Matthew Roger; Sinclair, Ian

    2011-01-01

    A short overview concerning variable amplitude (VA) fatigue crack growth behavior is presented in this paper. The topics covered in this review encompass important issues pertaining to both single and repeated overload transients. Reviews on transient post overload effects such as plasticity induced crack closure, crack tip blunting, residual stresses, crack deflection and branching, activation of near threshold mechanisms, strain hardening are highlighted. A brief summary on experimental trends and finite element modelling of overload induced crack closure is also presented

  11. Variable amplitude fatigue crack growth behavior - a short overview

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Konjengbam Darunkumar [Indian Institute of Technology, Guwahati (India); Parry, Matthew Roger [Airbus Operations Ltd, Bristol (United Kingdom); Sinclair, Ian [University of Southampton, Southampton (United Kingdom)

    2011-03-15

    A short overview concerning variable amplitude (VA) fatigue crack growth behavior is presented in this paper. The topics covered in this review encompass important issues pertaining to both single and repeated overload transients. Reviews on transient post overload effects such as plasticity induced crack closure, crack tip blunting, residual stresses, crack deflection and branching, activation of near threshold mechanisms, strain hardening are highlighted. A brief summary on experimental trends and finite element modelling of overload induced crack closure is also presented.

  12. A multilayer electro-thermal model of pouch battery during normal discharge and internal short circuit process

    International Nuclear Information System (INIS)

    Chen, Mingbiao; Bai, Fanfei; Song, Wenji; Lv, Jie; Lin, Shili

    2017-01-01

    Highlights: • 2D network equivalent circuit considers the interplay of cell units. • The temperature non-uniformity Φ of multilayer model is bigger than that of lumped model. • The temperature non-uniformity is quantified and the reason of non-uniformity is analyzed. • Increasing the thermal conductivity of the separator can effectively relieve the heat spot effect of ISC. - Abstract: As the electrical and thermal characteristic will affect the batteries’ safety, performance, calendar life and capacity fading, an electro-thermal coupled model for pouch battery LiFePO_4/C is developed in normal discharge and internal short circuit process. The battery is discretized into many cell elements which are united as a 2D network equivalent circuit. The electro-thermal model is solved with finite difference method. Non-uniformity of current distribution and temperature distribution is simulated and the result is validated with experiment data at various discharge rates. Comparison of the lumped model and the multilayer structure model shows that the temperature non-uniformity Φ of multilayer model is bigger than that of lumped model and shows more precise. The temperature non-uniformity is quantified and the reason of non-uniformity is analyzed. The electro-thermal model can also be used to guide the safety design of battery. The temperature of the ISC element near tabs is the highest because the equivalent resistance of the external circuit (not including the ISC element) is the smallest when the resistance of cell units is small. It is found that increasing the thermal conductivity of integrated layer can effectively relieve the heat spot effect of ISC.

  13. Estimation of expected short-circuit current levels in and circuit-breaker requirements for the 330 to 750 kV networks of the southern integrated power grid

    Energy Technology Data Exchange (ETDEWEB)

    Krivushkin, L.F.; Gorazeeva, T.F.

    1978-08-01

    Studies were made in order to project the operating levels in the Southern Integrated Power Grid to the year 2000. The short-circuit current levels and, the requirements which circuit breakers will have to meet are estimated. A gradual transition from 330 to 750 kV generation is foreseen, with 330 kV networks remaining only for a purely distribution service. The number of 330 kV line hookups and the number of circuit breakers at nodal points (stations and substations) will not change significantly, they will account for 40% of all circuit breakers installed in 25% of all nodal points. Short-circuit currents are expected to reach the 46 kA level in 750 kV networks and 63 kA (standing wave voltage 1.5 to 2.5 kV/microsecond) in 330 kV networks. These are the ratings of circuit breakers; of the 63 kA ones 150 will be needed by 1980--1990 and 400 by 1990--2000. It will also be eventually worthwhile to install circuit breakers with a 63 kA-750 kV rating.

  14. Effect of short circuited DC link capacitor of an AC–DC–AC inverter on the performance of induction motor

    Directory of Open Access Journals (Sweden)

    Hadeed Ahmed Sher

    2016-07-01

    Full Text Available Induction motors are widely used in industrial power plants due to their robustness, reliability and high performance under variable operating conditions in the electrical power system. Modern industrial progress is dependent on these ruggedly constructed induction motors. Almost every sophisticated process of the industry is based on induction motors. Most of these motors are controlled by means of inverters that change the line frequency. The change in parameters of inverter makes it possible to control the motor according to the design requirements. The reliability of inverter based motor control is an important issue for industrial applications and therefore, it becomes very vital for design engineers to have comprehensive analysis of the inverter fed induction machine. This paper investigates one of the faults that may occur on the DC link of an inverter fed induction motor. The effect of the capacitor short circuit is presented in this paper. It also deals with the effects of short circuited capacitor on freewheeling diode. DC link capacitors are well designed and even the probability of capacitor failure is high, it is always a rare case if they puncture, however this analysis will add to the reliability of the induction machine under variable operating condition.

  15. Internal Short-Circuiting Phenomena In An Open-Cycle MHD Generator

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Y.; Ishibashi, E. [Hitachi Research Laboratory, Hitachi-shi, Ibaraki-ken (Japan); Kasahara, T.; Kazawa, Y. [Hitachi Works, Hitachi Ltd., Hitachi-shi, Ibaraki-ken (Japan)

    1968-11-15

    The influence of internal electrical leakage due to circulating currents flowing through velocity boundary layers and due to metallic elements in insulating walls (peg walls) is experimentally investigated. For this purpose a combustion-driven MHD generator is utilized. The active part of the generator test section is 60 cm in length with a constant cross-section of 3 x 12 cm{sup 2}. At typical operating conditions about 70 g/s of diesel light oil is burned with oxygen-enriched air, resulting in a thermal input of 3 MW, a fluid velocity of 500 to 700 m/s and a gas temperature of 2700 to 2900 Degree-Sign K at the channel inlet. KOH is used as the seed material. The magnetic field can be raised up to 1.95 Teslas. In the range of lower magnetic fields (B < 0.8T) it is shown that an observed open-circuit voltage agrees well with the theoretical value OBh which is defined in a one-dimensional MHD model. In other words, the circulating currents scarcely affect the open-circuit voltage. The theoretical basis for this fact is obtained by the use of a simple model. Experimental results obtained in several runs using three sets of insulating walls show that thermal boundary layers at water-cooled metals are more conductive than expected and that the open- circuit voltage decreases because of leakage currents flowing through metal pegs, when the internal resistance of the generator is relatively large. Also, it is shown that an alumina coating is effective in reducing the leakage currents. (author)

  16. Lithium-Ion Battery Safety Study Using Multi-Physics Internal Short-Circuit Model (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, G-.H.; Smith, K.; Pesaran, A.

    2009-06-01

    This presentation outlines NREL's multi-physics simulation study to characterize an internal short by linking and integrating electrochemical cell, electro-thermal, and abuse reaction kinetics models.

  17. A SHORT-TERM CIRCUIT RESISTANCE PROGRAMME REDUCED EPICARDIAL FAT IN OBESE AGED WOMEN.

    Science.gov (United States)

    Rosety, Miguel Angel; Pery, Maria Teresa; Rodriguez-Pareja, Maria Antonia; Diaz, Antonio; Rosety, Jesus; Garcia, Natalia; Brenes-Martin, Francisco; Rosety-Rodríguez, Manuel; Toro, Rocío; Ordoñez, Francisco Javier; Rosety, Ignacio

    2015-11-01

    this study was conducted to ascertain the effects of resistance circuit training on epicardial adipose tissue (EAT) in obese aged women. A secondary objective was to assess muscle damage induced by supervised resistance training to confirm the intervention program was effective and safe. in the present interventional study, a total of 48 obese aged women were recruited from the community. Twenty-four of them were randomly assigned to perform a 12-week resistance circuit training programme, 3-days per week. This training was circularly performed in 6 stations: arm curl, leg extension, seated row, leg curl, triceps extension and leg press. The Jamar handgrip electronic dynamometer was used to assess maximal handgrip strength of the dominant hand. Two experienced observers assessed EAT by transthoracic two-dimensional echocardiography. Lastly, serum samples were analysed using one-step sandwich assays for creatine kinase activity (CK) and myoglobin (MB) concentration. as was hypothesized, resistance training significantly reduced EAT thickness (8.4 ± 1.0 vs. 7.3 ± 1.3 mm; p = 0.014; d = 0.76) in the experimental group. Resistance training induced no significant changes in markers of muscle damage such as CK (181.6 ± 36.9 vs. 194.2 ± 37.8 U/l; p = 0.31) and MB (62.4 ± 7.1 vs. 67.3 ± 7.7 ng/ml; p = 0.26). No significant changes in any of the tested outcomes were found in the control group. resistance training reduced EAT in aged obese women. A secondary finding was that the training program was effective and safe. While current results are promising, future studies are still required to consolidate this approach in clinical application. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  18. Study on Turn-to-turn Short Circuit On一line Monitoring System for Dry一type Ai r一core Reactor

    Directory of Open Access Journals (Sweden)

    GAO Zi-wei

    2017-04-01

    Full Text Available The change of current value caused by turn-to-turn short circuit of dry-type air-core reactor is so little that failure detection is difficult to be carried out. In order to solve this problem,a new on-line monitoring system based on impedance variation of turn-to-turn short circuit is proposed. The numerical method is applied to analyze the variation of equivalent resistance and equivalent reactance when dry-type air-core reactor winding short circuit happens in different places,and the monitoring method based on harmonic analysis method and quasi- synchronization sampling method is analyzed by theory. The hardware system,which takes single-chip microcomputer as the core of data processing and logic control,completes data acquisition of voltage signal and current signal of the reactor. In the respect of software design,the impedance variation will be uploaded to the PC after it has been calculated by using the above monitoring method,and then monitoring of turn-to-turn short circuit fault will be realized. Finally,the design of on-line monitoring system is studied by testing. The research result shows that,the equivalent resistance increases and the equivalent reactance decreases when turn-to-turn short circuit occurs,and the variation of equivalent resistance is more obvious than equivalent reactance. The experiment results prove that this monitoring method is true and the on-line monitoring system is feasible.

  19. Metabolic activation of amygdala, lateral septum and accumbens circuits during food anticipatory behavior.

    Science.gov (United States)

    Olivo, Diana; Caba, Mario; Gonzalez-Lima, Francisco; Rodríguez-Landa, Juan F; Corona-Morales, Aleph A

    2017-01-01

    When food is restricted to a brief fixed period every day, animals show an increase in temperature, corticosterone concentration and locomotor activity for 2-3h before feeding time, termed food anticipatory activity. Mechanisms and neuroanatomical circuits responsible for food anticipatory activity remain unclear, and may involve both oscillators and networks related to temporal conditioning. Rabbit pups are nursed once-a-day so they represent a natural model of circadian food anticipatory activity. Food anticipatory behavior in pups may be associated with neural circuits that temporally anticipate feeding, while the nursing event may produce consummatory effects. Therefore, we used New Zealand white rabbit pups entrained to circadian feeding to investigate the hypothesis that structures related to reward expectation and conditioned emotional responses would show a metabolic rhythm anticipatory of the nursing event, different from that shown by structures related to reward delivery. Quantitative cytochrome oxidase histochemistry was used to measure regional brain metabolic activity at eight different times during the day. We found that neural metabolism peaked before nursing, during food anticipatory behavior, in nuclei of the extended amygdala (basolateral, medial and central nuclei, bed nucleus of the stria terminalis), lateral septum and accumbens core. After pups were fed, however, maximal metabolic activity was expressed in the accumbens shell, caudate, putamen and cortical amygdala. Neural and behavioral activation persisted when animals were fasted by two cycles, at the time of expected nursing. These findings suggest that metabolic activation of amygdala-septal-accumbens circuits involved in temporal conditioning may contribute to food anticipatory activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Short-term Synaptic Depression in the Feedforward Inhibitory Circuit in the Dorsal Lateral Geniculate Nucleus.

    Science.gov (United States)

    Augustinaite, Sigita; Heggelund, Paul

    2018-05-24

    Synaptic short-term plasticity (STP) regulates synaptic transmission in an activity-dependent manner and thereby has important roles in the signal processing in the brain. In some synapses, a presynaptic train of action potentials elicits post-synaptic potentials that gradually increase during the train (facilitation), but in other synapses, these potentials gradually decrease (depression). We studied STP in neurons in the visual thalamic relay, the dorsal lateral geniculate nucleus (dLGN). The dLGN contains two types of neurons: excitatory thalamocortical (TC) neurons, which transfer signals from retinal afferents to visual cortex, and local inhibitory interneurons, which form an inhibitory feedforward loop that regulates the thalamocortical signal transmission. The overall STP in the retino-thalamic relay is short-term depression, but the distinct kind and characteristics of the plasticity at the different types of synapses are unknown. We studied STP in the excitatory responses of interneurons to stimulation of retinal afferents, in the inhibitory responses of TC neurons to stimulation of afferents from interneurons, and in the disynaptic inhibitory responses of TC neurons to stimulation of retinal afferents. Moreover, we studied STP at the direct excitatory input to TC neurons from retinal afferents. The STP at all types of the synapses showed short-term depression. This depression can accentuate rapid changes in the stream of signals and thereby promote detectability of significant features in the sensory input. In vision, detection of edges and contours is essential for object perception, and the synaptic short-term depression in the early visual pathway provides important contributions to this detection process. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Diagnosis of Short-Circuit Fault in Large-Scale Permanent-Magnet Wind Power Generator Based on CMAC

    Directory of Open Access Journals (Sweden)

    Chin-Tsung Hsieh

    2013-01-01

    Full Text Available This study proposes a method based on the cerebellar model arithmetic controller (CMAC for fault diagnosis of large-scale permanent-magnet wind power generators and compares the results with Error Back Propagation (EBP. The diagnosis is based on the short-circuit faults in permanent-magnet wind power generators, magnetic field change, and temperature change. Since CMAC is characterized by inductive ability, associative ability, quick response, and similar input signals exciting similar memories, it has an excellent effect as an intelligent fault diagnosis implement. The experimental results suggest that faults can be diagnosed effectively after only training CMAC 10 times. In comparison to training 151 times for EBP, CMAC is better than EBP in terms of training speed.

  2. Rapid battery depletion and loss of therapy due to a short circuit in bipolar DBS for essential tremor.

    Science.gov (United States)

    Allert, Niels; Barbe, Michael Thomas; Timmermann, Lars; Coenen, Volker Arnd

    2017-05-01

    Technical dysfunctions have been reported reducing efficacy of deep brain stimulation (DBS). Here, we report on an essential-tremor patient in whom a short circuit in bipolar DBS resulted not only in unilateral loss of therapy but also in high current flow and thereby rapid decline of the impulse-generator battery voltage from 2.83 V a week before the event to 2.54 V, indicating the need for an impulse-generator replacement. Immediate re-programming restored therapeutic efficacy. Moreover, the reduction in current flow allowed the battery voltage to recover without immediate surgical intervention to 2.81 V a week later.

  3. Navigating Monogamy: Nonapeptide Sensitivity in a Memory Neural Circuit May Shape Social Behavior and Mating Decisions

    Directory of Open Access Journals (Sweden)

    Alexander G. Ophir

    2017-07-01

    Full Text Available The role of memory in mating systems is often neglected despite the fact that most mating systems are defined in part by how animals use space. Monogamy, for example, is usually characterized by affiliative (e.g., pairbonding and defensive (e.g., mate guarding behaviors, but a high degree of spatial overlap in home range use is the easiest defining feature of monogamous animals in the wild. The nonapeptides vasopressin and oxytocin have been the focus of much attention for their importance in modulating social behavior, however this work has largely overshadowed their roles in learning and memory. To date, the understanding of memory systems and mechanisms governing social behavior have progressed relatively independently. Bridging these two areas will provide a deeper appreciation for understanding behavior, and in particular the mechanisms that mediate reproductive decision-making. Here, I argue that the ability to mate effectively as monogamous individuals is linked to the ability to track conspecifics in space. I discuss the connectivity across some well-known social and spatial memory nuclei, and propose that the nonapeptide receptors within these structures form a putative “socio-spatial memory neural circuit.” This purported circuit may function to integrate social and spatial information to shape mating decisions in a context-dependent fashion. The lateral septum and/or the nucleus accumbens, and neuromodulation therein, may act as an intermediary to relate socio-spatial information with social behavior. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating mating tactics is crucial to fully appreciate the suite of factors driving reproductive decisions and social decision-making.

  4. Navigating Monogamy: Nonapeptide Sensitivity in a Memory Neural Circuit May Shape Social Behavior and Mating Decisions

    Science.gov (United States)

    Ophir, Alexander G.

    2017-01-01

    The role of memory in mating systems is often neglected despite the fact that most mating systems are defined in part by how animals use space. Monogamy, for example, is usually characterized by affiliative (e.g., pairbonding) and defensive (e.g., mate guarding) behaviors, but a high degree of spatial overlap in home range use is the easiest defining feature of monogamous animals in the wild. The nonapeptides vasopressin and oxytocin have been the focus of much attention for their importance in modulating social behavior, however this work has largely overshadowed their roles in learning and memory. To date, the understanding of memory systems and mechanisms governing social behavior have progressed relatively independently. Bridging these two areas will provide a deeper appreciation for understanding behavior, and in particular the mechanisms that mediate reproductive decision-making. Here, I argue that the ability to mate effectively as monogamous individuals is linked to the ability to track conspecifics in space. I discuss the connectivity across some well-known social and spatial memory nuclei, and propose that the nonapeptide receptors within these structures form a putative “socio-spatial memory neural circuit.” This purported circuit may function to integrate social and spatial information to shape mating decisions in a context-dependent fashion. The lateral septum and/or the nucleus accumbens, and neuromodulation therein, may act as an intermediary to relate socio-spatial information with social behavior. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating mating tactics is crucial to fully appreciate the suite of factors driving reproductive decisions and social decision-making. PMID:28744194

  5. Optimization of the short-circuit current in an InP nanowire array solar cell through opto-electronic modeling.

    Science.gov (United States)

    Chen, Yang; Kivisaari, Pyry; Pistol, Mats-Erik; Anttu, Nicklas

    2016-09-23

    InP nanowire arrays with axial p-i-n junctions are promising devices for next-generation photovoltaics, with a demonstrated efficiency of 13.8%. However, the short-circuit current in such arrays does not match their absorption performance. Here, through combined optical and electrical modeling, we study how the absorption of photons and separation of the resulting photogenerated electron-hole pairs define and limit the short-circuit current in the nanowires. We identify how photogenerated minority carriers in the top n segment (i.e. holes) diffuse to the ohmic top contact where they recombine without contributing to the short-circuit current. In our modeling, such contact recombination can lead to a 60% drop in the short-circuit current. To hinder such hole diffusion, we include a gradient doping profile in the n segment to create a front surface barrier. This approach leads to a modest 5% increase in the short-circuit current, limited by Auger recombination with increased doping. A more efficient approach is to switch the n segment to a material with a higher band gap, like GaP. Then, a much smaller number of holes is photogenerated in the n segment, strongly limiting the amount that can diffuse and disappear into the top contact. For a 500 nm long top segment, the GaP approach leads to a 50% higher short-circuit current than with an InP top segment. Such a long top segment could facilitate the fabrication and contacting of nanowire array solar cells. Such design schemes for managing minority carriers could open the door to higher performance in single- and multi-junction nanowire-based solar cells.

  6. Bridging the Gap: Towards a Cell-Type Specific Understanding of Neural Circuits Underlying Fear Behaviors

    Science.gov (United States)

    McCullough, KM; Morrison, FG; Ressler, KJ

    2016-01-01

    Fear and anxiety-related disorders are remarkably common and debilitating, and are often characterized by dysregulated fear responses. Rodent models of fear learning and memory have taken great strides towards elucidating the specific neuronal circuitries underlying the learning of fear responses. The present review addresses recent research utilizing optogenetic approaches to parse circuitries underlying fear behaviors. It also highlights the powerful advances made when optogenetic techniques are utilized in a genetically defined, cell-type specific, manner. The application of next-generation genetic and sequencing approaches in a cell-type specific context will be essential for a mechanistic understanding of the neural circuitry underlying fear behavior and for the rational design of targeted, circuit specific, pharmacologic interventions for the treatment and prevention of fear-related disorders. PMID:27470092

  7. A method of increasing the sensitivity of protection from single-phase short-circuits to ground in the 6 – 10 kV network

    International Nuclear Information System (INIS)

    Manilov, A. M.; Mel’nik, D. A.

    2012-01-01

    A method of increasing the sensitivity of protection from single-phase short-circuits to ground by acting on the signal with brief dummy grounding of the neutral is described. After determining the damage, the neutral is again grounded through a high resistance and an arc-quenching reactor. An increase in the protection sensitivity is thereby obtained, the damage detection time is shortened, and the probability of the single-phase short-circuit to ground converting into double and multipoint earth faults is reduced.

  8. Application of Copper Cladding Aluminum Composites in UHV Portable Earthing and Short-circuiting Wires

    Directory of Open Access Journals (Sweden)

    Zhu Jianjun

    2018-01-01

    Full Text Available Aiming at the heavy weight and inconvenience when carrying and installing copper earthing wires on the UHV transmission lines, in this paper, we present the use of copper clad aluminum(CCA composite materials as a lightweight method for UHV earthing wire conductor. Theoretical calculations and tests of the fusing current in a short time for copper and CCA material are conducted. The results show that the theoretical value of the earthing wire conductor's fusing current corresponds with the test value on condition of the conductor cross section greater than 4mm2 as well as fusing time less than 1.5s. The CCA-10 earthing wires get 36.2% weight reduction compared with copper wires.

  9. Activation of adenosine low-affinity A3 receptors inhibits the enteric short interplexus neural circuit triggered by histamine.

    Science.gov (United States)

    Bozarov, Andrey; Wang, Yu-Zhong; Yu, Jun Ge; Wunderlich, Jacqueline; Hassanain, Hamdy H; Alhaj, Mazin; Cooke, Helen J; Grants, Iveta; Ren, Tianhua; Christofi, Fievos L

    2009-12-01

    We tested the novel hypothesis that endogenous adenosine (eADO) activates low-affinity A3 receptors in a model of neurogenic diarrhea in the guinea pig colon. Dimaprit activation of H2 receptors was used to trigger a cyclic coordinated response of contraction and Cl(-) secretion. Contraction-relaxation was monitored by sonomicrometry (via intracrystal distance) simultaneously with short-circuit current (I(sc), Cl(-) secretion). The short interplexus reflex coordinated response was attenuated or abolished by antagonists at H2 (cimetidine), 5-hydroxytryptamine 4 receptor (RS39604), neurokinin-1 receptor (GR82334), or nicotinic (mecamylamine) receptors. The A1 agonist 2-chloro-N(6)-cyclopentyladenosine (CCPA) abolished coordinated responses, and A1 antagonists could restore normal responses. A1-selective antagonists alone [8-cyclopentyltheophylline (CPT), 1,3-dipropyl-8-(2-amino-4-chlorophenyl)xanthine (PACPX), or 8-cyclopentyl-N(3)-[3-(4-(fluorosulfonyl)benzoyloxy)propyl]-xanthine (FSCPX)] caused a concentration-dependent augmentation of crypt cell secretion or contraction and acted at nanomolar concentrations. The A3 agonist N(6)-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) abolished coordinated responses and the A3 antagonist 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(+/-)-dihydropyridine-3,5-dicarboxylate (MRS1191) could restore and further augment responses. The IB-MECA effect was resistant to knockdown of adenosine A1 receptor with the irreversible antagonist FSCPX; the IC(50) for IB-MECA was 0.8 microM. MRS1191 alone could augment or unmask coordinated responses to dimaprit, and IB-MECA suppressed them. MRS1191 augmented distension-evoked reflex I(sc) responses. Adenosine deaminase mimicked actions of adenosine receptor antagonists. A3 receptor immunoreactivity was differentially expressed in enteric neurons of different parts of colon. After tetrodotoxin, IB-MECA caused circular muscle relaxation. The data support the novel concept that

  10. Illuminating the role of cholinergic signaling in circuits of attention and emotionally salient behaviors

    Directory of Open Access Journals (Sweden)

    Antonio eLuchicchi

    2014-10-01

    Full Text Available Acetylcholine (ACh signaling underlies specific aspects of cognitive functions and behaviors, including attention, learning, memory and motivation. Alterations in ACh signaling are involved in the pathophysiology of multiple neuropsychiatric disorders. In the central nervous system, ACh transmission is mainly guaranteed by dense innervation of select cortical and subcortical regions from disperse groups of cholinergic neurons within the basal forebrain (e.g. diagonal band, medial septal, nucleus basalis and the pontine-mesencephalic nuclei, respectively. Despite the fundamental role of cholinergic signaling in the CNS and the long standing knowledge of the organization of cholinergic circuitry, remarkably little is known about precisely how ACh release modulates cortical and subcortical neural activity and the behaviors these circuits subserve. Growing interest in cholinergic signaling in the CNS focuses on the mechanism(s of action by which endogenously released ACh regulates cognitive functions, acting as a neuromodulator and /or as a direct transmitter via nicotinic and muscarinic receptors. The development of optogenetic techniques has provided a valuable toolbox with which we can address these questions, as it allows the selective manipulation of the excitability of cholinergic inputs to the diverse array of cholinergic target fields within cortical and subcortical domains. Here, we review recent papers that use the light-sensitive opsins in the cholinergic system to elucidate the role of ACh in circuits related to attention and emotionally salient behaviors. In particular, we highlight recent optogenetic studies which have tried to disentangle the precise role of ACh in the modulation of cortical-, hippocampal- and striatal-dependent functions.

  11. Impact of adolescent social experiences on behavior and neural circuits implicated in mental illnesses.

    Science.gov (United States)

    Burke, Andrew R; McCormick, Cheryl M; Pellis, Sergio M; Lukkes, Jodi L

    2017-05-01

    Negative social experiences during adolescence are central features for several stress-related mental illnesses. Social play fighting behavior in rats peaks during early adolescence and is essential for the final maturation of brain and behavior. Manipulation of the rat adolescent social experience alters many neurobehavioral measurements implicated in anxiety, depression, and substance abuse. In this review, we will highlight the importance of social play and the use of three separate social stress models (isolation-rearing, social defeat, and social instability stress) to disrupt the acquisition of this adaptive behavior. Social stress during adolescence leads to the development of anxiety and depressive behavior as well as escalated drug use in adulthood. Furthermore, sex- and age-dependent effects on the hormonal stress response following adolescent social stress are also observed. Finally, manipulation of the social experience during adolescence alters stress-related neural circuits and monoaminergic systems. Overall, positive social experiences among age-matched conspecifics during rat adolescence are critical for healthy neurobehavioral maturation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Autism-associated neuroligin-3 mutations commonly impair striatal circuits to boost repetitive behaviors.

    Science.gov (United States)

    Rothwell, Patrick E; Fuccillo, Marc V; Maxeiner, Stephan; Hayton, Scott J; Gokce, Ozgun; Lim, Byung Kook; Fowler, Stephen C; Malenka, Robert C; Südhof, Thomas C

    2014-07-03

    In humans, neuroligin-3 mutations are associated with autism, whereas in mice, the corresponding mutations produce robust synaptic and behavioral changes. However, different neuroligin-3 mutations cause largely distinct phenotypes in mice, and no causal relationship links a specific synaptic dysfunction to a behavioral change. Using rotarod motor learning as a proxy for acquired repetitive behaviors in mice, we found that different neuroligin-3 mutations uniformly enhanced formation of repetitive motor routines. Surprisingly, neuroligin-3 mutations caused this phenotype not via changes in the cerebellum or dorsal striatum but via a selective synaptic impairment in the nucleus accumbens/ventral striatum. Here, neuroligin-3 mutations increased rotarod learning by specifically impeding synaptic inhibition onto D1-dopamine receptor-expressing but not D2-dopamine receptor-expressing medium spiny neurons. Our data thus suggest that different autism-associated neuroligin-3 mutations cause a common increase in acquired repetitive behaviors by impairing a specific striatal synapse and thereby provide a plausible circuit substrate for autism pathophysiology. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Modelling Li-ion cell thermal runaway triggered by an internal short circuit device using an efficiency factor and Arrhenius formulations

    DEFF Research Database (Denmark)

    Coman, Paul Tiberiu; Darcy, Eric; Veje, Christian

    2017-01-01

    This paper presents a novel model for analyzing the thermal runaway in Li-ion battery cells with an internal short circuit device implanted in the cell. The model is constructed using Arrhenius formulations for representing the self-heating chemical reactions and the State of Charge. The model...

  14. Short-circuit ruggedness assessment of a 1.2 kV/180 A SiC MOSFET power module

    DEFF Research Database (Denmark)

    Ionita, Claudiu; Nawaz, Muhammad; Ilves, Kalle

    2017-01-01

    is typically encountered in applications for devices of these ratings. Five modules were failed in total, with a critical short-circuit energy, Ecr ranging from 7.3 J to 9.7 J. The failure mechanism is generally the thermal runaway. Prior to failure, a decrease in VGS can be observed which is an indication...

  15. Prospective single and multi-phase short-circuit current levels in the Dutch transmission, sub-transmission and distribution grids

    NARCIS (Netherlands)

    Janssen, A.L.J.; van Riet, M.J.M.; Smeets, R.P.P.; Kanters, J.; van den Akker, W.F.; Aanhaanen, G.L.P.

    2012-01-01

    As elsewhere in the world, also in the Netherlands utilities face an increase in the actual and future short-circuit current levels at all voltages. This development is provoked by the required increase in transmission capacity as well as the concentration of power generation capacity. Large

  16. Sub-module Short Circuit Fault Diagnosis in Modular Multilevel Converter Based on Wavelet Transform and Adaptive Neuro Fuzzy Inference System

    DEFF Research Database (Denmark)

    Liu, Hui; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    for continuous operation and post-fault maintenance. In this article, a fault diagnosis technique is proposed for the short circuit fault in a modular multi-level converter sub-module using the wavelet transform and adaptive neuro fuzzy inference system. The fault features are extracted from output phase voltage...

  17. The factors influencing nonlinear characteristics of the short-circuit current in dye-sensitized solar cells investigated by a numerical model.

    Science.gov (United States)

    Shi, Yushuai; Dong, Xiandui

    2013-06-24

    A numerical model for interpretation of the light-intensity-dependent nonlinear characteristics of the short-circuit current in dye-sensitized solar cells is suggested. The model is based on the continuity equation and includes the influences of the nongeminate recombination between electrons and electron acceptors in the electrolyte and the geminate recombination between electrons and oxidized dye molecules. The influences of the order and rate constant of the nongeminate recombination reaction, the light-absorption coefficient of the dye, the film thickness, the rate constant of geminate recombination, and the regeneration rate constant on the nonlinear characteristics of the short-circuit current are simulated and analyzed. It is proposed that superlinear and sublinear characteristics of the short-circuit current should be attributed to low electron-collection efficiency and low dye-regeneration efficiency, respectively. These results allow a deep understanding of the origin of the nonlinear characteristics of the short-circuit current in solar cells. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Effects of an electromagnetic shield and armature teeth on the short-circuit performance of a direct drive superconducting generator for 10 MW wind turbines

    DEFF Research Database (Denmark)

    Liu, Dong; Polinder, Henk; Abrahamsen, Asger Bech

    2015-01-01

    reactance. An electromagnetic (EM) shield between the rotor and the stator as well as iron or non-magnetic composite (NMC) armature teeth affects the sub-transient reactance of a superconducting machine so that they play a role in the short-circuit performance of a superconducting wind generator. This paper...

  19. MATHEMATICAL MODELING OF TRANSIENT EMERGENCY ELECTROMAGNETIC PROCESSES IN THE SYSTEM OF THE ELECTROMAGNETIC TRACTION DC. 2. SHORT CIRCUIT WITH ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    P. E. Mihalichenko

    2010-04-01

    Full Text Available The article deals with the description of mathematical model of the system of traction electric power supply with load in the short circuit condition as well as the calculation results of this emergency process. The transition values as well as the character of their change, which can be used for detection of emergency processes, have been determined.

  20. Room Temperature Magnetic Field Measurements as a Tool to Localize Inter-turns Electrical Short Circuits in the LHC Main Dipole coils

    CERN Document Server

    Bellesia, B; Todesco, E

    2006-01-01

    In this report the method for the localization of the electric shorts circuits in the main LHC dipoles using the magnetic measurements at room temperature is presented. The steps of the method are discussed, and two cases are studied in detail. A complete statistics of the 12 cases analyzed up to now is given.

  1. Shaping vulnerability to addiction - the contribution of behavior, neural circuits and molecular mechanisms.

    Science.gov (United States)

    Egervari, Gabor; Ciccocioppo, Roberto; Jentsch, J David; Hurd, Yasmin L

    2018-02-01

    Substance use disorders continue to impose increasing medical, financial and emotional burdens on society in the form of morbidity and overdose, family disintegration, loss of employment and crime, while advances in prevention and treatment options remain limited. Importantly, not all individuals exposed to abused substances effectively develop the disease. Genetic factors play a significant role in determining addiction vulnerability and interactions between innate predisposition, environmental factors and personal experiences are also critical. Thus, understanding individual differences that contribute to the initiation of substance use as well as on long-term maladaptations driving compulsive drug use and relapse propensity is of critical importance to reduce this devastating disorder. In this paper, we discuss current topics in the field of addiction regarding individual vulnerability related to behavioral endophenotypes, neural circuits, as well as genetics and epigenetic mechanisms. Expanded knowledge of these factors is of importance to improve and personalize prevention and treatment interventions in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Multisensory integration for odor tracking by flying Drosophila: Behavior, circuits and speculation.

    Science.gov (United States)

    Duistermars, Brian J; Frye, Mark A

    2010-01-01

    Many see fruit flies as an annoyance, invading our homes with a nagging persistence and efficiency. Yet from a scientific perspective, these tiny animals are a wonder of multisensory integration, capable of tracking fragmented odor plumes amidst turbulent winds and constantly varying visual conditions. The peripheral olfactory, mechanosensory, and visual systems of the fruit fly, Drosophila melanogaster, have been studied in great detail;1-4 however, the mechanisms by which fly brains integrate information from multiple sensory modalities to facilitate robust odor tracking remain elusive. Our studies on olfactory orientation by flying flies reveal that these animals do not simply follow their "nose"; rather, fruit flies require mechanosensory and visual input to track odors in flight.5,6 Collectively, these results shed light on the neural circuits involved in odor localization by fruit flies in the wild and illuminate the elegant complexity underlying a behavior to which the annoyed and amazed are familiar.

  3. A Cortical Circuit for Sexually Dimorphic Oxytocin-Dependent Anxiety Behaviors.

    Science.gov (United States)

    Li, Kun; Nakajima, Miho; Ibañez-Tallon, Ines; Heintz, Nathaniel

    2016-09-22

    The frequency of human social and emotional disorders varies significantly between males and females. We have recently reported that oxytocin receptor interneurons (OxtrINs) modulate female sociosexual behavior. Here, we show that, in male mice, OxtrINs regulate anxiety-related behaviors. We demonstrate that corticotropin-releasing-hormone-binding protein (CRHBP), an antagonist of the stress hormone CRH, is specifically expressed in OxtrINs. Production of CRHBP blocks the CRH-induced potentiation of postsynaptic layer 2/3 pyramidal cell activity of male, but not female, mice, thus producing an anxiolytic effect. Our data identify OxtrINs as critical for modulation of social and emotional behaviors in both females and males and reveal a molecular mechanism that acts on local medial prefrontal cortex (mPFC) circuits to coordinate responses to OXT and CRH. They suggest that additional studies of the impact of the OXT/OXTR and CRHBP/CRH pathways in males and females will be important in development of gender-specific therapies. Published by Elsevier Inc.

  4. High performance of PbSe/PbS core/shell quantum dot heterojunction solar cells: short circuit current enhancement without the loss of open circuit voltage by shell thickness control.

    Science.gov (United States)

    Choi, Hyekyoung; Song, Jung Hoon; Jang, Jihoon; Mai, Xuan Dung; Kim, Sungwoo; Jeong, Sohee

    2015-11-07

    We fabricated heterojunction solar cells with PbSe/PbS core shell quantum dots and studied the precisely controlled PbS shell thickness dependency in terms of optical properties, electronic structure, and solar cell performances. When the PbS shell thickness increases, the short circuit current density (JSC) increases from 6.4 to 11.8 mA cm(-2) and the fill factor (FF) enhances from 30 to 49% while the open circuit voltage (VOC) remains unchanged at 0.46 V even with the decreased effective band gap. We found that the Fermi level and the valence band maximum level remain unchanged in both the PbSe core and PbSe/PbS core/shell with a less than 1 nm thick PbS shell as probed via ultraviolet photoelectron spectroscopy (UPS). The PbS shell reduces their surface trap density as confirmed by relative quantum yield measurements. Consequently, PbS shell formation on the PbSe core mitigates the trade-off relationship between the open circuit voltage and the short circuit current density. Finally, under the optimized conditions, the PbSe core with a 0.9 nm thick shell yielded a power conversion efficiency of 6.5% under AM 1.5.

  5. On-Line Detection of Coil Inter-Turn Short Circuit Faults in Dual-Redundancy Permanent Magnet Synchronous Motors

    Directory of Open Access Journals (Sweden)

    Yiguang Chen

    2018-03-01

    Full Text Available In the aerospace and military fields, with high reliability requirements, the dual-redundancy permanent magnet synchronous motor (DRPMSM with weak thermal coupling and no electromagnetic coupling is needed. A common fault in the DRPMSM is the inter-turn short circuit fault (ISCF. However, research on how to diagnose ISCF and the set of faulty windings in the DRPMSM is lacking. In this paper, the structure of the DRPMSM is analyzed and mathematical models of the motor under normal and faulty conditions are established. Then an on-line ISCF detection scheme, which depends on the running modes of the DRPMSM and the average values for the difference of the d-axis voltages between two sets of windings in the latest 20 sampling periods, is proposed. The main contributions of this paper are to analyze the calculation for the inductance of each part of the stator windings and propose the on-line diagnosis method of the ISCF under various operating conditions. The simulation and experimental results show that the proposed method can quickly and effectively diagnose ISCF and determine the set of faulty windings of the DRPMSM.

  6. KNOWLEDGE TRANSFER AND LEARNING: PROBLEMS OF KNOWLEDGE TRANSFER ASSOCIATED WITH TRYING TO SHORT-CIRCUIT THE LEARNING CYCLE

    Directory of Open Access Journals (Sweden)

    Sue Newell

    2006-11-01

    Full Text Available Knowledge is considered to be a key organizational resource in the 21st century and the knowledge management ‘movement’ has alerted organizations to the fact that they should more strategically exploit their knowledge assets. Companies are thus lured by the suggestion that they can gain competitive advantage by the more astute management of their knowledge base and in particular, by the transfer of knowledge across individuals, groups and organizational units, using IT to accomplish this. In this paper, we reflect on this common view of knowledge transfer. More specifically, we question an implication of this view - essentially the possibility of short-circuiting the learning cycle, so that individuals do not have to rely on their personal or shared experiences to identify better practices, but can learn from the codified lessons of others in IT systems. More importantly, we consider the characteristics of knowledge – that knowledge is distributed, ambiguous and disruptive – that makes its transfer highly problematic. Drawing on case research, we relate this to the learning cycle (Kolb 1984 and thereby identify barriers to knowledge transfer. We conclude by considering ways of overcoming these barriers by emphasizing the importance of social systems alongside technical systems.

  7. Open- and Short-Circuit Fault Identification for a Boost dc/dc Converter in PV MPPT Systems

    Directory of Open Access Journals (Sweden)

    Diego R. Espinoza Trejo

    2018-03-01

    Full Text Available This paper proposes a fault identification system for short and open-circuit switch faults (SOCSF for a dc/dc converter acting as a Maximum Power Point Tracker (MPPT in Photovoltaic (PV systems. A closed-loop operation is assumed for the boost dc/dc converter. A linearizing control plus a Proportional-Derivative (PD controller is suggested for PV voltage regulation at the maximum power point (MPP. In this study, the SOCSF are modeled by using an additive fault representation and the fault identification (FI system is synthesized departing from a Luenberger observer. Hence, an FI signal is obtained, which is insensitive to irradiance and load current changes, but affected by the SOCSF. For FI purposes, only the sensors used in the control system are needed. Finally, an experimental evaluation is presented by using a solar array simulator dc power supply and a boost dc/dc converter of 175 W in order to validate the ideas this study exposes.

  8. Theoretical and experimental analysis of a linear accelerator endowed with single feed coupler with movable short-circuit

    International Nuclear Information System (INIS)

    Forno, Massimo Dal; Craievich, Paolo; Penco, Giuseppe; Vescovo, Roberto

    2013-01-01

    The front-end injection systems of the FERMI@Elettra linac produce high brightness electron beams that define the performance of the Free Electron Laser. The photoinjector mainly consists of the radiofrequency (rf) gun and of two S-band rf structures which accelerate the beam. Accelerating structures endowed with a single feed coupler cause deflection and degradation of the electron beam properties, due to the asymmetry of the electromagnetic field. In this paper, a new type of single feed structure with movable short-circuit is proposed. It has the advantage of having only one waveguide input, but we propose a novel design where the dipolar component is reduced. Moreover, the racetrack geometry allows to reduce the quadrupolar component. This paper presents the microwave design and the analysis of the particle motion inside the linac. A prototype has been machined at the Elettra facility to verify the new coupler design and the rf field has been measured by adopting the bead-pull method. The results are here presented, showing good agreement with the expectations

  9. Small-Molecule Solar Cells with Simultaneously Enhanced Short-Circuit Current and Fill Factor to Achieve 11% Efficiency.

    Science.gov (United States)

    Nian, Li; Gao, Ke; Jiang, Yufeng; Rong, Qikun; Hu, Xiaowen; Yuan, Dong; Liu, Feng; Peng, Xiaobin; Russell, Thomas P; Zhou, Guofu

    2017-08-01

    High-efficiency small-molecule-based organic photovoltaics (SM-OPVs) using two electron donors (p-DTS(FBTTh 2 ) 2 and ZnP) with distinctively different absorption and structural features are reported. Such a combination works well and synergically improves device short-circuit current density (J sc ) to 17.99 mA cm -2 and fill factor (FF) to 77.19%, yielding a milestone efficiency of 11%. To the best of our knowledge, this is the highest power conversion efficiency reported for SM-OPVs to date and the first time to combine high J sc over 17 mA cm -2 and high FF over 77% into one SM-OPV. The strategy of using multicomponent materials, with a selecting role of balancing varied electronic and structural necessities can be an important route to further developing higher performance devices. This development is important, which broadens the dimension and versatility of existing materials without much chemistry input. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Grating-coupled surface plasmon enhanced short-circuit current in organic thin-film photovoltaic cells.

    Science.gov (United States)

    Baba, Akira; Aoki, Nobutaka; Shinbo, Kazunari; Kato, Keizo; Kaneko, Futao

    2011-06-01

    In this study, we demonstrate the fabrication of grating-coupled surface plasmon resonance (SPR) enhanced organic thin-film photovoltaic cells and their improved photocurrent properties. The cell consists of a grating substrate/silver/P3HT:PCBM/PEDOT:PSS structure. Blu-ray disk recordable substrates are used as the diffraction grating substrates on which silver films are deposited by vacuum evaporation. P3HT:PCBM films are spin-coated on silver/grating substrates. Low conductivity PEDOT:PSS/PDADMAC layer-by-layer ultrathin films deposited on P3HT:PCBM films act as the hole transport layer, whereas high conductivity PEDOT:PSS films deposited by spin-coating act as the anode. SPR excitations are observed in the fabricated cells upon irradiation with white light. Up to a 2-fold increase in the short-circuit photocurrent is observed when the surface plasmon (SP) is excited on the silver gratings as compared to that without SP excitation. The finite-difference time-domain simulation indicates that the electric field in the P3HT:PCBM layer can be increased using the grating-coupled SP technique. © 2011 American Chemical Society

  11. Mechanism of the entire overdischarge process and overdischarge-induced internal short circuit in lithium-ion batteries.

    Science.gov (United States)

    Guo, Rui; Lu, Languang; Ouyang, Minggao; Feng, Xuning

    2016-07-22

    Lithium-ion batteries connected in series are prone to be overdischarged. Overdischarge results in various side effects, such as capacity degradation and internal short circuit (ISCr). However, most of previous research on the overdischarge of a cell was terminated when the cell voltage dropped to 0 V, leaving the further impacts of overdischarge unclear. This paper investigates the entire overdischarge process of large-format lithium-ion batteries by discharging the cell to -100% state of charge (SOC). A significant voltage platform is observed at approximately -12% SOC, and ISCr is detected after the cell is overdischarged when passing the platform. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that the overdischarge-induced ISCr is caused by Cu deposition on electrodes, suggesting possible Cu collector dissolution at the voltage platform near -12% SOC. A prognostic/mechanistic model considering ISCr is used to evaluate the resistance of ISCr (RISCr), the value of which decreases sharply at the beginning of ISCr formation. Inducing the ISCr by overdischarge is effective and well controlled without any mechanical deformation or the use of a foreign substance.

  12. Eco-friendly preparation of large-sized graphene via short-circuit discharge of lithium primary battery.

    Science.gov (United States)

    Kang, Shaohong; Yu, Tao; Liu, Tingting; Guan, Shiyou

    2018-02-15

    We proposed a large-sized graphene preparation method by short-circuit discharge of the lithium-graphite primary battery for the first time. LiC x is obtained through lithium ions intercalation into graphite cathode in the above primary battery. Graphene was acquired by chemical reaction between LiC x and stripper agents with dispersion under sonication conditions. The gained graphene is characterized by Raman spectrum, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Atomic force microscope (AFM) and Scanning electron microscopy (SEM). The results indicate that the as-prepared graphene has a large size and few defects, and it is monolayer or less than three layers. The quality of graphene is significant improved compared to the reported electrochemical methods. The yield of graphene can reach 8.76% when the ratio of the H 2 O and NMP is 3:7. This method provides a potential solution for the recycling of waste lithium ion batteries. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Theoretical and experimental analysis of a linear accelerator endowed with single feed coupler with movable short-circuit.

    Science.gov (United States)

    Dal Forno, Massimo; Craievich, Paolo; Penco, Giuseppe; Vescovo, Roberto

    2013-11-01

    The front-end injection systems of the FERMI@Elettra linac produce high brightness electron beams that define the performance of the Free Electron Laser. The photoinjector mainly consists of the radiofrequency (rf) gun and of two S-band rf structures which accelerate the beam. Accelerating structures endowed with a single feed coupler cause deflection and degradation of the electron beam properties, due to the asymmetry of the electromagnetic field. In this paper, a new type of single feed structure with movable short-circuit is proposed. It has the advantage of having only one waveguide input, but we propose a novel design where the dipolar component is reduced. Moreover, the racetrack geometry allows to reduce the quadrupolar component. This paper presents the microwave design and the analysis of the particle motion inside the linac. A prototype has been machined at the Elettra facility to verify the new coupler design and the rf field has been measured by adopting the bead-pull method. The results are here presented, showing good agreement with the expectations.

  14. Impact of hydroelectric installations on the morphology's short-circuited reaches of the Durance and the Verdon Rivers

    International Nuclear Information System (INIS)

    Lefort, Philippe; Chapuis, Margot

    2012-01-01

    Attenuation of flood peaks by the reservoirs of Serre Poncon and along the Verdon River, and diversions of the Durance River's flow in the industrial canal significantly modify the flow regime in the short-circuited beds. Upstream inflow of gravel materials is decreased, bed-load transport is significantly reduced, channels' mobility is atrophied, or becomes even nonexistent. The vegetation impact leads then to an obstruction of the braided channel, the rare occurrence of high flows is not able to prevent. Clearing the bed has been and stays an efficient response to the vegetation encroachment, and a necessary condition to maintain the discharge capacity during high flow, the originality and the diversity of the natural landforms. The loss of mobility is also due to bed-load transport's interruption through dams, but even more to the past gravel extractions and to weirs that sustain low flow: bed-load transport restoration through dams, sedimentary recharge of the bed with gravels coming from lateral terraces and increasing of high flows intensity will lead to a minimal required mobility. (authors)

  15. Short-Circuit Fault Tolerant Control of a Wind Turbine Driven Induction Generator Based on Sliding Mode Observers

    Directory of Open Access Journals (Sweden)

    Takwa Sellami

    2017-10-01

    Full Text Available The installed energy production capacity of wind turbines is growing intensely on a global scale, making the reliability of wind turbine subsystems of greater significance. However, many faults like Inter-Turn Short-Circuit (ITSC may affect the turbine generator and quickly lead to a decline in supplied power quality. In this framework, this paper proposes a Sliding Mode Observer (SMO-based Fault Tolerant Control (FTC scheme for Induction Generator (IG-based variable-speed grid-connected wind turbines. First, the dynamic models of the wind turbine subsystems were developed. The control schemes were elaborated based on the Maximum Power Point Tracking (MPPT method and Indirect Rotor Flux Oriented Control (IRFOC method. The grid control was also established by regulating the active and reactive powers. The performance of the wind turbine system and the stability of injected power to the grid were hence analyzed under both healthy and faulty conditions. The robust developed SMO-based Fault Detection and Isolation (FDI scheme was proved to be fast and efficient for ITSC detection and localization.Afterwards, SMO were involved in scheming the FTC technique. Accordingly, simulation results assert the efficacy of the proposed ITSC FTC method for variable-speed wind turbines with faulty IG in protecting the subsystems from damage and ensuring continuous connection of the wind turbine to the grid during ITSC faults, hence maintaining power quality.

  16. Minimization of the Electromagnetic Torque Ripple Caused by the Coils Inter-Turn Short Circuit Fault in Dual-Redundancy Permanent Magnet Synchronous Motors

    Directory of Open Access Journals (Sweden)

    Yiguang Chen

    2017-11-01

    Full Text Available With the development of electric vehicles and More-Electric/All-Electric aircraft, high reliability is required in motor servo systems. The redundancy technique is one of the most effective methods to improve the reliability of motor servo systems. In this paper, the structure of dual-redundancy permanent magnet synchronous motor (DRPMSM with weak thermal coupling and no electromagnetic coupling is analyzed and the mathematical model of this motor is established. However, there is little research on how to suppress the torque ripple caused by short-circuited coils in the DRPMSM. The main contribution of this paper is to present the advantages of DRPMSM and to find a way to suppress the torque ripple caused by the short circuit fault in DRPMSM. In order to improve operation quality and enhance the reliability of DRPMSM after a short circuit occurs, the torque ripple caused by the coils inter-turn short circuit fault in DRPMSM is analyzed in detail. Then, a control method for suppressing the electromagnetic torque ripple of a short-circuited coil is proposed for the first time by using an improved adaptive proportional resonant (PR controller and a proportional integral (PI controller in parallel. PR control is a method of controlling alternating components without steady-state error, and it can be used to suppress torque ripple. DRPMSM adopts speed and current double closed-loop control strategies. An improved adaptive PR controller and a PI controller are employed in parallel for the speed loop, while traditional PI control is adopted in current loop. From the simulation and experimental results, the torque ripple is reduced from 45.4 to 5.6% when the torque ripple suppression strategy proposed in this paper is adopted, in the case that the speed is 600 r/min. The torque ripple suppression strategy based on the PR controller can quickly and effectively suppress the torque ripple caused by the short-circuited coils, which makes the motor speed

  17. Analog circuit design designing dynamic circuit response

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    This second volume, Designing Dynamic Circuit Response builds upon the first volume Designing Amplifier Circuits by extending coverage to include reactances and their time- and frequency-related behavioral consequences.

  18. Analog circuit design : low voltage low power; short range wireless front-ends; power management and DC-DC

    NARCIS (Netherlands)

    Steyaert, M.; Roermund, van A.H.M.; Baschirotto, A.

    2012-01-01

    The book contains the contribution of 18 tutorials of the 20th workshop on Advances in Analog Circuit Design. Each part discusses a specific to-date topic on new and valuable design ideas in the area of analog circuit design. Each part is presented by six experts in that field and state of the art

  19. Overcoming Short-Circuit in Lead-Free CH3NH3SnI3 Perovskite Solar Cells via Kinetically Controlled Gas-Solid Reaction Film Fabrication Process.

    Science.gov (United States)

    Yokoyama, Takamichi; Cao, Duyen H; Stoumpos, Constantinos C; Song, Tze-Bin; Sato, Yoshiharu; Aramaki, Shinji; Kanatzidis, Mercouri G

    2016-03-03

    The development of Sn-based perovskite solar cells has been challenging because devices often show short-circuit behavior due to poor morphologies and undesired electrical properties of the thin films. A low-temperature vapor-assisted solution process (LT-VASP) has been employed as a novel kinetically controlled gas-solid reaction film fabrication method to prepare lead-free CH3NH3SnI3 thin films. We show that the solid SnI2 substrate temperature is the key parameter in achieving perovskite films with high surface coverage and excellent uniformity. The resulting high-quality CH3NH3SnI3 films allow the successful fabrication of solar cells with drastically improved reproducibility, reaching an efficiency of 1.86%. Furthermore, our Kelvin probe studies show the VASP films have a doping level lower than that of films prepared from the conventional one-step method, effectively lowering the film conductivity. Above all, with (LT)-VASP, the short-circuit behavior often obtained from the conventional one-step-fabricated Sn-based perovskite devices has been overcome. This study facilitates the path to more successful Sn-perovskite photovoltaic research.

  20. The effect of acute hypoxia on short-circuit current and epithelial resistivity in biopsies from human colon.

    Science.gov (United States)

    Carra, Graciela E; Ibáñez, Jorge E; Saraví, Fernando D

    2013-09-01

    In isolated colonic mucosa, decreases in short-circuit current (ISC) and transepithelial resistivity (RTE) occur when hypoxia is either induced at both sides or only at the serosal side of the epithelium. We assessed in human colon biopsies the sensitivity to serosal-only hypoxia and mucosal-only hypoxia and whether Na, K-ATPase blockade with ouabain interacts with hypoxia. Biopsy material from patients undergoing colonoscopy was mounted in an Ussing chamber for small samples (1-mm2 window). In a series of experiments we assessed viability and the electrical response to the mucolytic, dithiothreitol (1 mmol/l). In a second series, we explored the effect of hypoxia without and with ouabain. In a third series, we evaluated the response to a cycle of hypoxia and reoxygenation induced at the serosal or mucosal side while keeping the oxygenation of the opposite side. 1st series: Dithiothreitol significantly decreased the unstirred layer and ISC but increased RTE. 2nd series: Both hypoxia and ouabain decreased ISC, but ouabain increased RTE and this effect on RTE prevailed even during hypoxia. 3rd series: Mucosal hypoxia caused lesser decreases of ISC and RTE than serosal hypoxia; in the former, but not in the latter, recovery was complete upon reoxygenation. In mucolytic concentration, dithiothreitol modifies ISC and RTE. Oxygen supply from the serosal side is more important to sustain ISC and RTE in biopsy samples. The different effect of hypoxia and Na, K-ATPase blockade on RTE suggests that their depressing effect on ISC involves different mechanisms.

  1. Approximate entropy—a new statistic to quantify arc and welding process stability in short-circuiting gas metal arc welding

    International Nuclear Information System (INIS)

    Cao Biao; Xiang Yuanpeng; Lü Xiaoqing; Zeng Min; Huang Shisheng

    2008-01-01

    Based on the phase state reconstruction of welding current in short-circuiting gas metal arc welding using carbon dioxide as shielding gas, the approximate entropy of welding current as well as its standard deviation has been calculated and analysed to investigate their relation with the stability of electric arc and welding process. The extensive experimental and calculated results show that the approximate entropy of welding current is significantly and positively correlated with arc and welding process stability, whereas its standard deviation is correlated with them negatively. A larger approximate entropy and a smaller standard deviation imply a more stable arc and welding process, and vice versa. As a result, the approximate entropy of welding current promises well in assessing and quantifying the stability of electric arc and welding process in short-circuiting gas metal arc welding

  2. Increased short circuit current in organic photovoltaic using high-surface area electrode based on ZnO nanowires decorated with CdTe quantum dots.

    Science.gov (United States)

    Aga, R S; Gunther, D; Ueda, A; Pan, Z; Collins, W E; Mu, R; Singer, K D

    2009-11-18

    A photosensitized high-surface area transparent electrode has been employed to increase the short circuit current of a photovoltaic device with a blend of poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl C61 butyric acid methyl ester (PCBM) as the active layer. This is achieved by directly growing ZnO nanowires on indium tin oxide (ITO) film via a physical vapor method. The nanowire surface is then decorated with CdTe quantum dots by pulsed electron-beam deposition (PED). The nanowires alone provided a 20-fold increase in the short circuit current under visible light illumination. This was further increased by a factor of approximately 1.5 by the photosensitization effect of CdTe, which has an optical absorption of up to 820 nm.

  3. Inverted Fuel Cell: Room-Temperature Hydrogen Separation from an Exhaust Gas by Using a Commercial Short-Circuited PEM Fuel Cell without Applying any Electrical Voltage.

    Science.gov (United States)

    Friebe, Sebastian; Geppert, Benjamin; Caro, Jürgen

    2015-06-26

    A short-circuited PEM fuel cell with a Nafion membrane has been evaluated in the room-temperature separation of hydrogen from exhaust gas streams. The separated hydrogen can be recovered or consumed in an in situ olefin hydrogenation when the fuel cell is operated as catalytic membrane reactor. Without applying an outer electrical voltage, there is a continuous hydrogen flux from the higher to the lower hydrogen partial pressure side through the Nafion membrane. On the feed side of the Nafion membrane, hydrogen is catalytically split into protons and electrons by the Pt/C electrocatalyst. The protons diffuse through the Nafion membrane, the electrons follow the short-circuit between the two brass current collectors. On the cathode side, protons and electrons recombine, and hydrogen is released. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Analysis of the impact of connecting a larger number of small hydroelectric power plants to the short-circuit currents values and relay protection system of distribution network

    Directory of Open Access Journals (Sweden)

    Sučević Nikola

    2017-01-01

    Full Text Available In this paper the influence of a large number of small hydro power plants on the short-circuit currents is analysed, as well as the operation of the relay protection system within the real distribution network in Serbia. The necessary modification of the existing protection functions, as well as the implementation of the new proposed protection functions, are presented and discussed. Network modeling and analysis are performed using the program tool DIgSILENT PowerFactory.

  5. Crack closure and growth behavior of short fatigue cracks under random loading (part I : details of crack closure behavior)

    International Nuclear Information System (INIS)

    Lee, Shin Young; Song, Ji Ho

    2000-01-01

    Crack closure and growth behavior of physically short fatigue cracks under random loading are investigated by performing narrow-and wide-band random loading tests for various stress ratios. Artificially prepared two-dimensional, short through-thickness cracks are used. The closure behavior of short cracks under random loading is discussed, comparing with that of short cracks under constant-amplitude loading and also that of long cracks under random loading. Irrespective of random loading spectrum or block length, the crack opening load of short cracks is much lower under random loading than under constant-amplitude loading corresponding to the largest load cycle in a random load history, contrary to the behavior of long cracks that the crack opening load under random loading is nearly the same as or slightly higher than constant-amplitude results. This result indicates that the largest load cycle in a random load history has an effect to enhance crack opening of short cracks

  6. Interhemispheric claustral circuits coordinate somatomotor and visuomotor cortical areas that regulate exploratory behaviors

    Directory of Open Access Journals (Sweden)

    Jared Brent Smith

    2014-05-01

    Full Text Available The claustrum has a role in the interhemispheric transfer of certain types of sensorimotor information. Whereas the whisker region in rat motor (M1 cortex sends dense projections to the contralateral claustrum, the M1 forelimb representation does not. The claustrum sends strong ipsilateral projections to the whisker regions in M1 and somatosensory (S1 cortex, but its projections to the forelimb cortical areas are weak. These distinctions suggest that one function of the M1 projections to the contralateral claustrum is to coordinate the cortical areas that regulate peripheral sensor movements during behaviors that depend on bilateral sensory acquisition. If this hypothesis is true, then similar interhemispheric circuits should interconnect the frontal eye fields (FEF with the contralateral claustrum and its network of projections to vision-related cortical areas. To test this hypothesis, anterograde and retrograde tracers were placed in physiologically-defined parts of the FEF and primary visual cortex (V1 in rats. We observed dense FEF projections to the contralateral claustrum that terminated in the midst of claustral neurons that project to both FEF and V1. While the FEF inputs to the claustrum come predominantly from the contralateral hemisphere, the claustral projections to FEF and V1 are primarily ipsilateral. Detailed comparison of the present results with our previous studies on somatomotor claustral circuitry revealed a well-defined functional topography in which the ventral claustrum is connected with visuomotor cortical areas and the dorsal regions are connected with somatomotor areas. These results suggest that subregions within the claustrum play a critical role in coordinating the cortical areas that regulate the acquisition of modality-specific sensory information during exploration and other behaviors that require sensory attention.

  7. Behavioral modeling of the dominant dynamics in input-output transfer of linear(ized) circuits

    NARCIS (Netherlands)

    Beelen, T.G.J.; Maten, ter E.J.W.; Sihaloho, H.J.; Eijndhoven, van S.J.L.

    2010-01-01

    We present a powerful procedure for determining both the dominant dynamics of the inputoutput transfer and the corresponding most influential circuit parameters of a linear(ized) circuit. The procedure consists of several steps in which a specific (sub)problem is solved and its solution is used in

  8. Short circuit behavior of distribution grids with a large share of distributied generation units

    NARCIS (Netherlands)

    Coster, E.J.; Karaliolios, P.; Xyngi, I.; Slootweg, J.G.; Popov, M.; Kling, W.L.; Sluis, van der L.

    2011-01-01

    increasing rapidly. Most of these units are connected to the distribution grid. With the increasing penetration level the impact of these units on for instance power flows, fault levels and protective systems cannot be neglected anymore. To allow an increasing penetration level of DG without causing

  9. The malleable brain: plasticity of neural circuits and behavior - a review from students to students.

    Science.gov (United States)

    Schaefer, Natascha; Rotermund, Carola; Blumrich, Eva-Maria; Lourenco, Mychael V; Joshi, Pooja; Hegemann, Regina U; Jamwal, Sumit; Ali, Nilufar; García Romero, Ezra Michelet; Sharma, Sorabh; Ghosh, Shampa; Sinha, Jitendra K; Loke, Hannah; Jain, Vishal; Lepeta, Katarzyna; Salamian, Ahmad; Sharma, Mahima; Golpich, Mojtaba; Nawrotek, Katarzyna; Paidi, Ramesh K; Shahidzadeh, Sheila M; Piermartiri, Tetsade; Amini, Elham; Pastor, Veronica; Wilson, Yvette; Adeniyi, Philip A; Datusalia, Ashok K; Vafadari, Benham; Saini, Vedangana; Suárez-Pozos, Edna; Kushwah, Neetu; Fontanet, Paula; Turner, Anthony J

    2017-06-20

    One of the most intriguing features of the brain is its ability to be malleable, allowing it to adapt continually to changes in the environment. Specific neuronal activity patterns drive long-lasting increases or decreases in the strength of synaptic connections, referred to as long-term potentiation and long-term depression, respectively. Such phenomena have been described in a variety of model organisms, which are used to study molecular, structural, and functional aspects of synaptic plasticity. This review originated from the first International Society for Neurochemistry (ISN) and Journal of Neurochemistry (JNC) Flagship School held in Alpbach, Austria (Sep 2016), and will use its curriculum and discussions as a framework to review some of the current knowledge in the field of synaptic plasticity. First, we describe the role of plasticity during development and the persistent changes of neural circuitry occurring when sensory input is altered during critical developmental stages. We then outline the signaling cascades resulting in the synthesis of new plasticity-related proteins, which ultimately enable sustained changes in synaptic strength. Going beyond the traditional understanding of synaptic plasticity conceptualized by long-term potentiation and long-term depression, we discuss system-wide modifications and recently unveiled homeostatic mechanisms, such as synaptic scaling. Finally, we describe the neural circuits and synaptic plasticity mechanisms driving associative memory and motor learning. Evidence summarized in this review provides a current view of synaptic plasticity in its various forms, offers new insights into the underlying mechanisms and behavioral relevance, and provides directions for future research in the field of synaptic plasticity. Read the Editorial Highlight for this article on doi: 10.1111/jnc.14102. © 2017 International Society for Neurochemistry.

  10. AC and DC electrical behavior of MWCNT/epoxy nanocomposite near percolation threshold: Equivalent circuits and percolation limits

    Science.gov (United States)

    Alizadeh Sahraei, Abolfazl; Ayati, Moosa; Baniassadi, Majid; Rodrigue, Denis; Baghani, Mostafa; Abdi, Yaser

    2018-03-01

    This study attempts to comprehensively investigate the effects of multi-walled carbon nanotubes (MWCNTs) on the AC and DC electrical conductivity of epoxy nanocomposites. The samples (0.2, 0.3, and 0.5 wt. % MWCNT) were produced using a combination of ultrason and shear mixing methods. DC measurements were performed by continuous measurement of the current-voltage response and the results were analyzed via a numerical percolation approach, while for the AC behavior, the frequency response was studied by analyzing phase difference and impedance in the 10 Hz to 0.2 MHz frequency range. The results showed that the dielectric parameters, including relative permittivity, impedance phase, and magnitude, present completely different behaviors for the frequency range and MWCNT weight fractions studied. To better understand the nanocomposites electrical behavior, equivalent electric circuits were also built for both DC and AC modes. The DC equivalent networks were developed based on the current-voltage curves, while the AC equivalent circuits were proposed by using an optimization problem according to the impedance magnitude and phase at different frequencies. The obtained equivalent electrical circuits were found to be highly useful tools to understand the physical mechanisms involved in MWCNT filled polymer nanocomposites.

  11. Feasibility Study of the PS Injection for 2 GeV LIU Beams with an Upgraded KFA-45 Injection Kicker System Operating in Short Circuit Mode

    CERN Document Server

    Kramer, Thomas; Borburgh, Jan; Ducimetière, Laurent; Feliciano, Luis; Ferrero Colomo, Alvaro; Goddard, Brennan; Sermeus, Luc

    2016-01-01

    Under the scope of the LIU project the CERN PS Booster to PS beam transfer will be modified to match the requirements for the future 2 GeV beams. This paper describes the evaluation of the proposed upgrade of the PS injection kicker. Different schemes of an injection for LIU beams into the PS have been outlined in the past already under the aspect of individual transfer kicker rise and fall time performances. Homogeneous rise and fall time requirements in the whole PSB to PS transfer chain have been established which allowed to consider an upgrade option of the present injection kicker system operated in short circuit mode. The challenging pulse quality constraints require an improvement of the flat top and post pulse ripples. Both operation modes, terminated and short circuit mode are analysed and analogue circuit simulations for the present and upgraded system are outlined. Recent measurements on the installed kickers are presented and analysed together with the simulation data. First measurements verifying...

  12. Parallel basal ganglia circuits for decision making.

    Science.gov (United States)

    Hikosaka, Okihide; Ghazizadeh, Ali; Griggs, Whitney; Amita, Hidetoshi

    2018-03-01

    The basal ganglia control body movements, mainly, based on their values. Critical for this mechanism is dopamine neurons, which sends unpredicted value signals, mainly, to the striatum. This mechanism enables animals to change their behaviors flexibly, eventually choosing a valuable behavior. However, this may not be the best behavior, because the flexible choice is focused on recent, and, therefore, limited, experiences (i.e., short-term memories). Our old and recent studies suggest that the basal ganglia contain separate circuits that process value signals in a completely different manner. They are insensitive to recent changes in value, yet gradually accumulate the value of each behavior (i.e., movement or object choice). These stable circuits eventually encode values of many behaviors and then retain the value signals for a long time (i.e., long-term memories). They are innervated by a separate group of dopamine neurons that retain value signals, even when no reward is predicted. Importantly, the stable circuits can control motor behaviors (e.g., hand or eye) quickly and precisely, which allows animals to automatically acquire valuable outcomes based on historical life experiences. These behaviors would be called 'skills', which are crucial for survival. The stable circuits are localized in the posterior part of the basal ganglia, separately from the flexible circuits located in the anterior part. To summarize, the flexible and stable circuits in the basal ganglia, working together but independently, enable animals (and humans) to reach valuable goals in various contexts.

  13. Short-Term Effects of Televised Aggression on Children's Behavior.

    Science.gov (United States)

    Liebert, Robert M.; Baron, Robert A.

    Recently collected data appear to warrant advancing some tentative conslusions concerning the short-term effects of violence in television on children: 1) children are exposed to a substantial amount of violent content on television, and they can remember and learn from such exposure; 2) correlational studies have disclosed a regular association…

  14. Optimal planning of series resistor to control time constant of test circuit for high-voltage AC circuit-breakers

    OpenAIRE

    Yoon-Ho Kim; Jung-Hyeon Ryu; Jin-Hwan Kim; Kern-Joong Kim

    2016-01-01

    The equivalent test circuit that can deliver both short-circuit current and recovery voltage is used to verify the performance of high-voltage circuit breakers. Most of the parameters in this circuit can be obtained by using a simple calculation or a simulation program. The ratings of the circuit breaker include rated short-circuit breaking current, rated short-circuit making current, rated operating sequence of the circuit breaker and rated short-time current. Among these ratings, the short-...

  15. Water quality, hydrology, and the effects of changes in phosphorus loading to Pike Lake, Washington County, Wisconsin, with special emphasis on inlet-to-outlet short-circuiting

    Science.gov (United States)

    Rose, William J.; Robertson, Dale M.; Mergener, Elizabeth A.

    2004-01-01

    Pike Lake is a 459-acre, mesotrophic to eutrophic dimictic lake in southeastern Wisconsin. Because of concern over degrading water quality in the lake associated with further development in its watershed, a study was conducted by the U.S. Geological Survey from 1998 to 2000 to describe the water quality and hydrology of the lake, quantify sources of phosphorus including the effects of short-circuiting of inflows, and determine how changes in phosphorus loading should affect the water quality of the lake. Measuring all significant water and phosphorus sources and estimating lesser sources was the method used to construct detailed water and phosphorus budgets. The Rubicon River, ungaged near-lake surface inflow, precipitation, and ground water provide 55, 20, 17, and 7 percent of the total inflow, respectively. Water leaves the lake through the Rubicon River outlet (87 percent) or by evaporation (13 percent). Total input of phosphorus to the lake was about 3,500 pounds in 1999 and 2,400 pounds in 2000. About 80 percent of the phosphorus was from the Rubicon River, about half of which came from the watershed and half from a waste-water treatment plant in Slinger, Wisconsin. Inlet-to-outlet short-circuiting of phosphorus is facilitated by a meandering segment of the Rubicon River channel through a marsh at the north end of the lake. It is estimated that 77 percent of phosphorus from the Rubicon River in monitoring year 1999 and 65 percent in monitoring year 2000 was short-circuited to the outlet without entering the main body of the lake.

  16. Fault clearance in medium-voltage networks using remote-monitored short-circuit alarms; Stoerungsbeseitigung im MS-Netz mit fernueberwachten Kurzschlussmeldern

    Energy Technology Data Exchange (ETDEWEB)

    Beran, B. [Reginalzentrum Neckar-Franken der EnBW Regional AG, Oehringen (Germany). Bereich Netzfuehrung; Deiss, R. [RBS Genius GmbH, Stuttgart (Germany). Bereich Korrosionsschutz und Gaslecksuche; Stibbe, T. [Phoenix Contact GmbH und Co KG, Blomberg (Lippe) (Germany). Vertrieb Deutschland

    2006-04-15

    In March 2005, a pilot project on remote monitoring of short-circuit alarms using GSM was started. In cooperation with RBS Genius GmbH (100 percent subsidiary of EnBW Regional AG) who already use a similar technology for controlling cathodic corrosion protection systems, and the EnBW-Regionalzentrum Neckar-Franken, the functionalities were specified. After only five months of development and assembly time, the first 15 units were installed in exposed and difficult-to-access sites. All sites were located along very long power lines in which localisation of the defect would be very time-consuming. (orig.)

  17. A Flexible Power Control Method of VSC-HVDC Link for the Enhancement of Effective Short-Circuit Ratio in a Hybrid Multi-Infeed HVDC System

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2013-01-01

    . To evaluate the contribution of the VSC-HVDC link on the voltage stability of HMIDC system, this paper proposes an effective short circuit ratio (ESCR) calculation method. Through the calculation, the voltage support capability of the VSC-HVDC link can be quantitatively represented by the ESCR. Furthermore......, based on the calculation results, a flexible power control strategy for the VSC-HVDC link is developed to provide maximum reactive power support under grid faults. The theoretical analysis of the HMIDC system is based on the Danish transmission grid, evaluated through PSCAD simulations under different...

  18. Hybrid solar cells with outstanding short-circuit currents based on a room temperature soft-chemical strategy: the case of P3HT:Ag2S.

    Science.gov (United States)

    Lei, Yan; Jia, Huimin; He, Weiwei; Zhang, Yange; Mi, Liwei; Hou, Hongwei; Zhu, Guangshan; Zheng, Zhi

    2012-10-24

    P3HT:Ag(2)S hybrid solar cells with broad absorption from the UV to NIR band were directly fabricated on ITO glass by using a room temperature, low energy consumption, and low-cost soft-chemical strategy. The resulting Ag(2)S nanosheet arrays facilitate the construction of a perfect percolation structure with organic P3HT to form ordered bulk heterojunctions (BHJ); without interface modification, the assembled P3HT:Ag(2)S device exhibits outstanding short-circuit current densities (J(sc)) around 20 mA cm(-2). At the current stage, the optimized device exhibited a power conversion efficiency of 2.04%.

  19. Pacing Behavior and Tactical Positioning in 500-and 1000-m Short-Track Speed Skating

    NARCIS (Netherlands)

    Noorbergen, Olaf S.; Konings, Marco J.; Micklewright, Dominic; Elferink-Gemser, Marge T.; Hettinga, Florentina J.

    Purpose: To explore pacing behavior and tactical positioning during the shorter 500- and 1000-m short-track competitions. Methods: Lap times and intermediate rankings of elite 500- and 1000-m short-track-skating competitors were collected over the 2012-13 season. First, lap times were analyzed using

  20. Fracture behavior of short circumferentially surface-cracked pipe

    International Nuclear Information System (INIS)

    Krishnaswamy, P.; Scott, P.; Mohan, R.

    1995-11-01

    This topical report summarizes the work performed for the Nuclear Regulatory Comniission's (NRC) research program entitled ''Short Cracks in Piping and Piping Welds'' that specifically focuses on pipes with short, circumferential surface cracks. The following details are provided in this report: (i) material property deteminations, (ii) pipe fracture experiments, (iii) development, modification and validation of fracture analysis methods, and (iv) impact of this work on the ASME Section XI Flaw Evaluation Procedures. The material properties developed and used in the analysis of the experiments are included in this report and have been implemented into the NRC's PIFRAC database. Six full-scale pipe experiments were conducted during this program. The analyses methods reported here fall into three categories (i) limit-load approaches, (ii) design criteria, and (iii) elastic-plastic fracture methods. These methods were evaluated by comparing the analytical predictions with experimental data. The results, using 44 pipe experiments from this and other programs, showed that the SC.TNP1 and DPZP analyses were the most accurate in predicting maximum load. New Z-factors were developed using these methods. These are being considered for updating the ASME Section XI criteria

  1. Nonlinear behavior analysis of split-winding dry-type transformer using a new star model and a coupled field-circuit approach

    Directory of Open Access Journals (Sweden)

    Azizian Davood

    2016-12-01

    Full Text Available Regarding the importance of short circuit and inrush current simulations in the split-winding transformer, a novel nonlinear equivalent circuit is introduced in this paper for nonlinear simulation of this transformer. The equivalent circuit is extended using the nonlinear inductances. Employing a numerical method, leakage and magnetizing inductances in the split-winding transformer are extracted and the nonlinear model inductances are estimated using these inductances. The introduced model is validated and using this nonlinear model, inrush and short-circuit currents are calculated. It has been seen that the introduced model is valid and suitable for simulations of the split-winding transformer due to various loading conditions. Finally, the effects of nonlinearity of the model inductances are discussed in the following.

  2. Short (

    NARCIS (Netherlands)

    Telleman, Gerdien; den Hartog, Laurens

    2013-01-01

    Aim: This systematic review assessed the implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients. A case report of a short implant in the posterior region have been added. Materials and methods: A search was conducted in the electronic databases of MEDLINE

  3. The Influence of Auditory Short-Term Memory on Behavior Problem Development

    Science.gov (United States)

    Low, Justin; Keith, Timothy

    2015-01-01

    The purpose of this research was to determine the influence of two subcomponents of auditory short-term memory on the developmental trajectories of behavior problems. The sample included 7,058 children from the NLSY79--Children and Young Adult survey between the ages 5 and 14 years. Results suggested that anxious/depressed behavior increases…

  4. Complete or partial reduction of the Met receptor tyrosine kinase in distinct circuits differentially impacts mouse behavior.

    Science.gov (United States)

    Thompson, Barbara L; Levitt, Pat

    2015-01-01

    Our laboratory discovered that the gene encoding the receptor tyrosine kinase, MET, contributes to autism risk. Expression of MET is reduced in human postmortem temporal lobe in autism and Rett Syndrome. Subsequent studies revealed a role for MET in human and mouse functional and structural cortical connectivity. To further understand the contribution of Met to brain development and its impact on behavior, we generated two conditional mouse lines in which Met is deleted from select populations of central nervous system neurons. Mice were then tested to determine the consequences of disrupting Met expression. Mating of Emx1 (cre) and Met (fx/fx) mice eliminates receptor signaling from all cells arising from the dorsal pallium. Met (fx/fx) and Nestin (cre) crosses result in receptor signaling elimination from all neural cells. Behavioral tests were performed to assess cognitive, emotional, and social impairments that are observed in multiple neurodevelopmental disorders and that are in part subserved by circuits that express Met. Met (fx/fx) /Emx1 (cre) null mice displayed significant hypoactivity in the activity chamber and in the T-maze despite superior performance on the rotarod. Additionally, these animals showed a deficit in spontaneous alternation. Surprisingly, Met (fx/fx; fx/+) /Nestin (cre) null and heterozygous mice exhibited deficits in contextual fear conditioning, and Met (fx/+) /Nestin (cre) heterozygous mice spent less time in the closed arms of the elevated plus maze. These data suggest a complex contribution of Met in the development of circuits mediating social, emotional, and cognitive behavior. The impact of disrupting developmental Met expression is dependent upon circuit-specific deletion patterns and levels of receptor activity.

  5. A study on the short-circuit test by fault angle control and the recovery characteristics of the fault current limiter using coated conductor

    International Nuclear Information System (INIS)

    Park, D.K.; Kim, Y.J.; Ahn, M.C.; Yang, S.E.; Seok, B.-Y.; Ko, T.K.

    2007-01-01

    Superconducting fault current limiters (SFCLs) have been developed in many countries, and they are expected to be used in the recent electric power systems, because of their great efficiency for operating these power system stably. It is necessary for resistive FCLs to generate resistance immediately and to have a fast recovery characteristic after the fault clearance, because of re-closing operation. Short-circuit tests are performed to obtained current limiting operational and recovery characteristics of the FCL by a fault controller using a power switching device. The power switching device consists of anti-parallel connected thyristors. The fault occurs at the desired angle by controlling the firing angle of thyristors. Resistive SFCLs have different current limiting characteristics with respect to the fault angle in the first swing during the fault. This study deals with the short-circuit characteristic of FCL coils using two different YBCO coated conductors (CCs), 344 and 344s, by controlling the fault angle and experimental studies on the recovery characteristic by a small current flowing through the SFCL after the fault clearance. Tests are performed at various voltages applied to the SFCL in a saturated liquid nitrogen cooling system

  6. Evolution of short circuit levels in the National Electric System, years 2007 to 2011; Evolucion de los niveles de cortocircuito del Sistema Electrico Nacional, anos 2007 al 2011

    Energy Technology Data Exchange (ETDEWEB)

    Quintana Castaneda, J; Reyes Escobedo, G [Instituto de Investigaciones Electricas (Mexico)]. E-mails: jqc@iie.org.mx; gustavo.reyes@iie.org.mx; Ibarra Romo, F.G. [Comision Federal de Electricidad (Mexico)]. E-mail: federico.ibarra@cfe.gob.mx

    2013-03-15

    The present document shows an analysis of 2011 short-circuit levels on the different nodes (substations) that integrate the National Electric System. This analysis presents the figures of short-circuit levels on past years, stating on 2007, with the purpose of detecting the variation on each one of these nodes and identify the cases that because it's high levels are considered as critical nodes of the transmission system. At the end of the analysis some recommendations to minimize the potential risks are given on those substations classified as critical nodes. [Spanish] En este documento se expone un analisis de los niveles de cortocircuito que se presentaron en el 2011 en los distintos nodos (subestaciones) que conforman la red del Sistema Electrico Nacional (SEN). Este analisis muestra las cifras de los niveles de cortocircuito que se han presentado desde el ano 2007, a fin de estudiar el comportamiento y evolucion que han tenido los nodos de la red electrica, identificando aquellos puntos que por sus altos niveles de cortocircuito se consideran como nodos criticos. En la parte final del analisis se dan algunas recomendaciones para disminuir los riesgos que se pudieran presentar en aquellas subestaciones clasificadas como nodos criticos.

  7. Adrenomedullin increases the short-circuit current in the rat prostate: Receptors, chloride channels, the effects of cAMP and calcium ions and implications on fluid secretion.

    Science.gov (United States)

    Liao, S B; Cheung, K H; Cheung, M P L; Wong, P F; O, W S; Tang, F

    2014-05-01

    In this study, we have investigated the effects of adrenomedullin on chloride and fluid secretion in the rat prostate. The presence of adrenomedullin (ADM) in rat prostate was confirmed using immunostaining, and the molecular species was determined using gel filtration chromatography coupled with an enzyme-linked assay for ADM. The effects of ADM on fluid secretion were studied by short-circuit current technique in a whole mount preparation of the prostate in an Ussing chamber. The results indicated that the ADM level was higher in the ventral than the dorso-lateral prostate and the major molecular species was the active peptide. ADM increased the short-circuit current through both the cAMP- and calcium-activated chloride channels in the ventral lobe, but only through the calcium-activated channels in the dorso-lateral lobe. These stimulatory effects were blocked by the calcitonin gene-related peptide (CGRP) receptor antagonist, hCGRP8-37. We conclude that ADM may regulate prostatic fluid secretion through the chloride channels, which may affect the composition of the seminal plasma bathing the spermatozoa and hence fertility. © 2014 American Society of Andrology and European Academy of Andrology.

  8. Influence of Metal Transfer Stability and Shielding Gas Composition on CO and CO2 Emissions during Short-circuiting MIG/MAG Welding

    Directory of Open Access Journals (Sweden)

    Valter Alves de Meneses

    Full Text Available Abstract: Several studies have demonstrated the influence of parameters and shielding gas on metal transfer stability or on the generation of fumes in MIG/MAG welding, but little or nothing has been discussed regarding the emission of toxic and asphyxiating gases, particularly as it pertains to parameterization of the process. The purpose of this study was to analyze and evaluate the effect of manufacturing aspects of welding processes (short-circuit metal transfer stability and shielding gas composition on the gas emission levels during MIG/MAG welding (occupational health and environmental aspects. Using mixtures of Argon with CO2 and O2 and maintaining the same average current and the same weld bead volume, short-circuit welding was performed with carbon steel welding wire in open (welder’s breathing zone and confined environments. The welding voltage was adjusted to gradually vary the transfer stability. It was found that the richer the composition of the shielding gas is in CO2, the more CO and CO2 are generated by the arc. However, unlike fume emission, voltage and transfer stability had no effect on the generation of these gases. It was also found that despite the large quantity of CO and CO2 emitted by the arc, especially when using pure CO2 shielding gas, there was no high level residual concentration of CO and CO2 in or near the worker’s breathing zone, even in confined work cells.

  9. Detecting the single line to ground short circuit fault in the submarine’s power system using the artificial neural network

    Directory of Open Access Journals (Sweden)

    Behniafar Ali

    2013-01-01

    Full Text Available The electric marine instruments are newly inserted in the trade and industry, for which the existence of an equipped and reliable power system is necessitated. One of the features of such a power system is that it cannot have an earth system causing the protection relays not to be able to detect the single line to ground short circuit fault. While on the other hand, the occurrence of another similar fault at the same time can lead to the double line fault and thereby the tripping of relays and shortening of vital loads. This in turn endangers the personals' security and causes the loss of military plans. From the above considerations, it is inferred that detecting the single line to ground fault in the marine instruments is of a special importance. In this way, this paper intends to detect the single line to ground fault in the power systems of the marine instruments using the wavelet transform and Multi-Layer Perceptron (MLP neural network. In the numerical analysis, several different types of short circuit faults are simulated on several marine power systems and the proposed approach is applied to detect the single line to ground fault. The results are of a high quality and preciseness and perfectly demonstrate the effectiveness of the proposed approach.

  10. Analysis of short and long crack behavior and single overload effect by crack opening stress

    International Nuclear Information System (INIS)

    Song, Sam Hong; Lee, Kyeong Ro

    1999-01-01

    The study analyzed the behaviors of short and long crack as well as the effect of single tensile overload on the crack behaviors by using fatigue crack opening behavior. Crack opening stress is measured by an elastic compliance method which may precisely and continuously provide many data using strain gages during experiment. The unusual growth behaviors of short crack and crack after the single tensile overload applied, was explained by the variations of crack opening stress. In addition, fatigue crack growth rate was expressed as a linear form for short crack as for long crack by using effective stress intensity factor range as fracture mechanical parameter, which is based on crack closure concept. And investigation is performed with respect to the relation between plastic zone size formed at the crack tip and crack retardation, crack length and the number of cycles promoted or retarded, and the overload effect on the fatigue life

  11. Short forms of the Texas Social Behavior Inventory /TSBI/, an objective measure of self-esteem

    Science.gov (United States)

    Helmreich, R.; Stapp, J.

    1974-01-01

    Two short (16 item) forms of the Helmreich, Stapp, and Ervin (1974) Texas Social Behavior Inventory, a validated, objective measure of self-esteem or social competence are presented. Normative data and other statistics are described for males and females. Correlations between each short form and long (32-item) scale were .97. Factor analysis and part-whole correlations verified the similarity of the two forms. The utility of the scale in research is described.

  12. Effect of the depth base along the vertical on the electrical parameters of a vertical parallel silicon solar cell in open and short circuit

    Directory of Open Access Journals (Sweden)

    Gokhan Sahin

    2018-03-01

    Full Text Available This article presented a modeling study of effect of the depth base initiating on vertical parallel silicon solar cell’s photovoltaic conversion efficiency. After the resolution of the continuity equation of excess minority carriers, we calculated the electrical parameters such as the photocurrent density, the photovoltage, series resistance and shunt resistances, diffusion capacitance, electric power, fill factor and the photovoltaic conversion efficiency. We determined the maximum electric power, the operating point of the solar cell and photovoltaic conversion efficiency according to the depth z in the base. We showed that the photocurrent density decreases with the depth z. The photovoltage decreased when the depth base increases. Series and shunt resistances were deduced from electrical model and were influenced and the applied the depth base. The capacity decreased with the depth z of the base. We had studied the influence of the variation of the depth z on the electrical parameters in the base. Keywords: Depth base, Conversion efficiency, Electrical parameters, Open circuit, Short circuit

  13. Extra high speed modified Lundell alternator parameters and open/short-circuit characteristics from global 3D-FE magnetic field solutions

    Science.gov (United States)

    Wang, R.; Demerdash, N. A.

    1992-06-01

    The combined magnetic vector potential - magnetic scalar potential method of computation of 3D magnetic fields by finite elements, introduced in a companion paper, is used for global 3D field analysis and machine performance computations under open-circuit and short-circuit conditions for an example 14.3 kVA modified Lundell alternator, whose magnetic field is of intrinsic 3D nature. The computed voltages and currents under these machine test conditions were verified and found to be in very good agreement with corresponding test data. Results of use of this modelling and computation method in the study of a design alteration example, in which the stator stack length of the example alternator is stretched in order to increase voltage and volt-ampere rating, are given here. These results demonstrate the inadequacy of conventional 2D-based design concepts and the imperative of use of this type of 3D magnetic field modelling in the design and investigation of such machines.

  14. Extra high speed modified Lundell alternator parameters and open/short-circuit characteristics from global 3D-FE magnetic field solutions

    Science.gov (United States)

    Wang, R.; Demerdash, N. A.

    1992-01-01

    The combined magnetic vector potential - magnetic scalar potential method of computation of 3D magnetic fields by finite elements, introduced in a companion paper, is used for global 3D field analysis and machine performance computations under open-circuit and short-circuit conditions for an example 14.3 kVA modified Lundell alternator, whose magnetic field is of intrinsic 3D nature. The computed voltages and currents under these machine test conditions were verified and found to be in very good agreement with corresponding test data. Results of use of this modelling and computation method in the study of a design alteration example, in which the stator stack length of the example alternator is stretched in order to increase voltage and volt-ampere rating, are given here. These results demonstrate the inadequacy of conventional 2D-based design concepts and the imperative of use of this type of 3D magnetic field modelling in the design and investigation of such machines.

  15. Improvement of Short-Circuit Current Density in Dye-Sensitized Solar Cells Using Sputtered Nanocolumnar TiO2 Compact Layer

    Directory of Open Access Journals (Sweden)

    Lung-Chien Chen

    2010-01-01

    Full Text Available The effect of a nanocolumnar TiO2 compact layer in dye-sensitized solar cells (DSSCs was examined. Such a compact layer was sputtered on a glass substrate with an indium tin oxide (ITO film using TiO2 powder as the raw material, with a thickness of ~100 nm. The compact layer improved the short-circuit current density and the efficiency of conversion of solar energy to electricity by the DSSC by 53.37% and 59.34%, yielding values of 27.33 mA/cm2 and 9.21%, respectively. The performance was attributed to the effective electron pathways in the TiO2 compact layer, which reduced the back reaction by preventing direct contact between the redox electrolyte and the conductive substrate.

  16. Size optimization for complex permeability measurement of magnetic thin films using a short-circuited microstrip line up to 30 GHz

    Science.gov (United States)

    Takeda, Shigeru; Naoe, Masayuki

    2018-03-01

    High-frequency permeability spectra of magnetic films were measured over a wideband frequency range of 0.1-30 GHz using a shielded and short-circuited microstrip line jig. In this measurement, spurious resonances had to be suppressed up to the highest frequency. To suppress these resonances, characteristic impedance of the microstrip line should approach 50 Ω at the junction between connector and microstrip line. The main factors dominating these resonances were structures of the jig and the sample. The dimensions were optimized in various experiments, and results demonstrated that the frequency could be raised to at least 20 GHz. For the transverse electromagnetic mode to transmit stably along the microstrip line, the preferred sample was rectangular, with the shorter side parallel to the line and the longer side perpendicular to it, and characteristic impedance strongly depended on the signal line width of the jig. However, too small a jig and sample led to a lower S/N ratio.

  17. Predictive Validity of the Columbia-Suicide Severity Rating Scale for Short-Term Suicidal Behavior

    DEFF Research Database (Denmark)

    Conway, Paul Maurice; Erlangsen, Annette; Teasdale, Thomas William

    2017-01-01

    adolescents (90.6% females) who participated at follow-up (85.9%) out of the 99 (49.7%) baseline respondents. All adolescents were recruited from a specialized suicide-prevention clinic in Denmark. Through multivariate logistic regression analyses, we examined whether baseline suicidal behavior predicted......Using the Columbia-Suicide Severity Rating Scale (C-SSRS), we examined the predictive and incremental predictive validity of past-month suicidal behavior and ideation for short-term suicidal behavior among adolescents at high risk of suicide. The study was conducted in 2014 on a sample of 85...... subsequent suicidal behavior (actual attempts and suicidal behavior of any type, including preparatory acts, aborted, interrupted and actual attempts; mean follow-up of 80.8 days, SD = 52.4). Furthermore, we examined whether suicidal ideation severity and intensity incrementally predicted suicidal behavior...

  18. Ape Behavior in Two Alternating Environments: Comparing Exhibit and Short-Term Holding Areas

    DEFF Research Database (Denmark)

    Ross, Stephen R.; Wagner, Katherine E.; Schapiro, Steven J.

    2010-01-01

    be balanced with the desire to maintain enriching and naturalistic exhibit enclosures that benefit ape residents and attract the visiting public. In these settings, examinations of ape behavior and welfare typically focus exclusively on activity in the primary exhibit area. However, physical, social...... and sensory experiences unique to each area may shape different patterns of behavior. In the current study, zoo-living chimpanzees and gorillas were moved each day from exhibit areas to off-exhibit holding areas for a short duration as a part of regular management procedures. Behavioral data indicated species......-specific reactions to the holding area, including increased aggression and self-directed behavior by chimpanzees and increased activity and prosocial behavior among gorilla subjects. Both species showed more feeding-foraging behavior while in the exhibit enclosure. Results suggest that holding areas may not meet all...

  19. Short-Term Compassion Training Increases Prosocial Behavior in a Newly Developed Prosocial Game

    Science.gov (United States)

    Leiberg, Susanne; Klimecki, Olga; Singer, Tania

    2011-01-01

    Compassion has been suggested to be a strong motivator for prosocial behavior. While research has demonstrated that compassion training has positive effects on mood and health, we do not know whether it also leads to increases in prosocial behavior. We addressed this question in two experiments. In Experiment 1, we introduce a new prosocial game, the Zurich Prosocial Game (ZPG), which allows for repeated, ecologically valid assessment of prosocial behavior and is sensitive to the influence of reciprocity, helping cost, and distress cues on helping behavior. Experiment 2 shows that helping behavior in the ZPG increased in participants who had received short-term compassion training, but not in participants who had received short-term memory training. Interindividual differences in practice duration were specifically related to changes in the amount of helping under no-reciprocity conditions. Our results provide first evidence for the positive impact of short-term compassion training on prosocial behavior towards strangers in a training-unrelated task. PMID:21408020

  20. Short-term effects of upper extremity circuit resistance training on muscle strength and functional independence in patients with paraplegia.

    Science.gov (United States)

    Yildirim, Adem; Sürücü, Gülseren Dost; Karamercan, Ayşe; Gedik, Dilay Eken; Atci, Nermin; Dülgeroǧlu, Deniz; Özgirgin, Neşe

    2016-11-21

    A number of exercises to strengthen the upper extremities are recommended to increase functional independence and quality of life (QoL) in patients with paraplegia. Circuit resistance training (CRT) is a type of progressive resistive exercise performed repeatedly at fixed mechanical exercise stations. The aim of this study was to investigate the potential benefits of CRT for upper extremity muscle strength, functional independence, and QoL in patients with paraplegia. Twenty-six patients with paraplegia who were participating in a conventional rehabilitation program at a tertiary education and research hospital were enrolled in this study. The participants were randomly assigned to two groups. The exercise group participated in the CRT program, which consisted of repetitive exercises for the upper extremities performed at fixed mechanical stations 5 sessions per week for 6 weeks, in addition to conventional rehabilitation. Participants in the control group received only conventional rehabilitation over the same period. We compared the groups with respect to QoL, as well as isokinetic muscle test outcomes in the upper extremities, using the Functional Independence Measure (FIM) and Borg's scale. We observed significant increases in scores on the physical component of the FIM, Borg's scale, and QoL in both the exercise and control groups. Furthermore, the large majority of isokinetic values were significantly more improved in the exercise group compared to the control group. When post-treatment outcomes were compared between the groups, improvements in scores on the physical component of the FIM and in most isokinetic values were significantly greater in the exercise group. This study showed that CRT has positive effects on muscle strength in the upper extremities and the physical disability components of the FIM when added to conventional rehabilitation programs for paraplegic patients. However, we observed no significant improvement in QoL scores after adding CRT

  1. Effects of arginine vasotocin and mesotocin on the activation and development of amiloride-blockable short-circuit current across larval, adult, and cultured larval bullfrog skins.

    Science.gov (United States)

    Takada, Makoto; Fujimaki-Aoba, Kayo; Hokari, Shigeru

    2010-03-01

    Amphibian skin has osmoregulatory functions, with Na(+) crossing from outside to inside. Na(+) transport can be measured as the short-circuit current (SCC). We investigated the short-term and long-term effects of arginine vasotocin (AVT) and mesotocin (MT) (which modulate Na(+) transport) on the activation and development of an amiloride-blockable SCC (adult-type feature) in larval, adult, and corticoid-cultured larval bullfrog skins. We found: (1) AVT-receptor (AVT-R) and MT-receptor (MT-R) mRNAs could be detected in both larval and adult skins, (2) in the short term (within 60 min), the larval SCC (amiloride-stimulated SCC) was increased by AVT, forskolin, and MT, suggesting that AVT and MT did not activate the inactive ENaC (epithelial sodium channel) protein thought to be expressed in larval skin, (3) in the short term (within 90 min), AVT, forskolin, and MT stimulated the adult SCC (amiloride-blockable SCC), (4) AVT and MT increased both the larval and adult SCC via receptors insensitive to OPC-21268 (an antagonist of the V(1)-type receptor), OPC-31260 (an antagonist of the V(2)-type receptor), and ([d(CH(2))(5),Tyr(Me)(2),Thr(4),Orn(8),des-Gly-NH (2) (9) ]VT) (an antagonist of the oxytocin receptor), (5) culturing EDTA-treated larval skin with corticoids supplemented with AVT (1 microM) or MT (1 microM) for 2 weeks (long-term effects of AVT and MT) did not alter the corticoid-induced development of an amiloride-blockable SCC (adult-type feature). AVT and MT thus have the potential to stimulate SCC though channels that are already expressed, but they may not influence the development of the amiloride-blockable SCC (an adult-type feature) in larval skin.

  2. Sequential reduction of external networks for the security- and short circuit monitor in power system control centers

    Energy Technology Data Exchange (ETDEWEB)

    Dietze, P [Siemens A.G., Erlangen (Germany, F.R.). Abt. ESTE

    1978-01-01

    For the evaluation of the effects of switching operations or simulation of line, transformer, and generator outages the influence of interconnected neighbor networks is modelled by network equivalents in the process computer. The basic passive conductivity model is produced by sequential reduction and adapted to fit the active network behavior. The reduction routine uses the admittance matrix, sparse technique and optimal ordering; it is applicable to process computer applications.

  3. An Icepak-PSpice Co-Simulation Method to Study the Impact of Bond Wires Fatigue on the Current and Temperature Distribution of IGBT Modules under Short-Circuit

    DEFF Research Database (Denmark)

    Wu, Rui; Iannuzzo, Francesco; Wang, Huai

    2014-01-01

    Bond wires fatigue is one of the dominant failure mechanisms of IGBT modules. Prior-art research mainly focuses on its impact on the end-of-life failure, while its effect on the short-circuit capability of IGBT modules is still an open issue. This paper proposes a new electro-thermal simulation...... approach enabling analyze the impact of the bond wires fatigue on the current and temperature distribution on IGBT chip surface under short-circuit. It is based on an Icepack-PSpice co-simulation by taking the advantage of both a finite element thermal model and an advanced PSpice-based multi-cell IGBT...

  4. Impact of Short-Term Training in Social Cognition in Preschoolers with Externalizing Behavior

    Science.gov (United States)

    Houssa, Marine; Jacobs, Emilie; Nader-Grosbois, Nathalie

    2017-01-01

    In two experimental and exploratory studies, we wanted to test the differentiated effects on preschoolers with externalizing behavior (EB) of two short-term social information processing (SIP) and Theory of Mind (ToM) training sessions, in comparison with typically developing (TD) preschoolers or with preschoolers with EB whom didn't receive…

  5. Introducing a short measure of shared servant leadership impacting team performance through team behavioral integration

    NARCIS (Netherlands)

    M. Sousa (Milton); D. van Dierendonck (Dirk)

    2016-01-01

    textabstractThe research reported in this paper was designed to study the influence of shared servant leadership on team performance through the mediating effect of team behavioral integration, while validating a new short measure of shared servant leadership. A round-robin approach was used to

  6. Influence of nonmetals recycled from waste printed circuit boards on flexural properties and fracture behavior of polypropylene composites

    International Nuclear Information System (INIS)

    Zheng Yanhong; Shen Zhigang; Cai Chujiang; Ma Shulin; Xing Yushan

    2009-01-01

    Flexural strength and flexural modulus of the composites can be successfully improved by filling nonmetals recycled from waste printed circuit boards (PCBs) into polypropylene (PP). By using scanning electron microscopy (SEM), the influence of nonmetals on fracture behavior of PP composites is investigated by in situ flexural test. Observation results show that the particles can effectively lead to mass micro cracks instead of the breaking crack. The process of the crack initiation, propagation and fiber breakage dissipate a great amount of energy. As a result, the flexural properties of the composites can be reinforced significantly. Results of the in situ SEM observation and analysis to the dynamic flexural process supply effective test evidence for the reinforcing mechanism of the nonmetals/PP composites on the basis of the energy dissipation theory

  7. Power distribution and substrate noise coupling investigations on the behavioral level for photon counting imaging readout circuits

    International Nuclear Information System (INIS)

    Lundgren, Jan; Abdalla, Suliman; O'Nils, Mattias; Oelmann, Bengt

    2007-01-01

    In modern mixed-signal system design, there are increasing problems associated with noise coupling caused by switching digital parts to sensitive analog parts. As a consequence, there is a growing necessity to understand these problems. In order to avoid costly design iterations, noise coupling simulations should be initiated as early as possible in the design chain. The problems associated with on-chip noise coupling have been discovered in photon counting pixel detector readout systems, where the level of integration of analog and digital circuits is very high on a very small area, and it would appear that these problems will continue to increase for future system designs in this field. This paper deals with the functionality of utilizing behavioral level models for simulating noise coupling in these readout systems. The methods and models are described and simulation results are shown for a photon counting pixel detector readout system

  8. Electrochemical migration, whisker formation, and corrosion behavior of printed circuit board under wet H2S environment

    International Nuclear Information System (INIS)

    Zou, Shiwen; Li, Xiaogang; Dong, Chaofang; Ding, Kangkang; Xiao, Kui

    2013-01-01

    Highlights: •The electrochemical migration, whisker formation, and corrosion behavior of PCB under wet H 2 S environment were observed and studied systematically. •The process of electrochemical migration of solder joints is explained. •The corrosion mechanism of PCB interconnectors induced by micro pores under wet H 2 S environment is discussed, and the corrosion reaction model is proposed. -- Abstract: Electrochemical migration, whisker formation, and corrosion behavior of printed circuit board (PCB) under wet H 2 S environment were analyzed by environment scanning electron microscope (ESEM), Energy dispersive X-ray spectroscopy (EDS) with mapping and element phase cluster (EPC) techniques, Raman Spectrum analysis and electrochemical impedance spectroscopy (EIS) technology. The results showed that nonuniform corrosion behavior occurred on PCB surfaces under 1 ppm wet H 2 S at 40 °C; whiskers formed on the inner sidewall of via-holes with a growth rate of 1.2 Å/s; numerous corrosion products migrated through the pore of plated gold layer, which broke off the protective layer. The corrosion rate was accelerated according to the big-cathode-small-anode model

  9. Asbestos as 'toxic short-circuit' optic-fibre for UV within the cell-net: — Likely roles and hazards for secret UV and IR metabolism

    International Nuclear Information System (INIS)

    Traill, Robert R

    2011-01-01

    The most toxic asbestos fibres have widths 250nm-10nm, and this toxicity is 'physical', which could mean either mechanical or optical: Tangling with chromosomes is a mechanical hazard occasionally reported, and fibres 100nm wide — or chrysotile (white asbestos) is >150nm. In both cases, UV A /UV B -transmission would then predominate. (Chrysotile 150nm might be benign — escaping both mechanical and optical!). But what would generate such UV, and why would its transmission be toxic? Thar and Kühl (J.Theor.Biol.:2004) explain that the long mitochondria on microtubules may be able to act as UV-lasers, (and many observers since Gurwitsch 1923 have reported ultraweak UV emissions escaping from all types of living bio-tissue). That all suggests some universal secret role for UV, apparently related to mitosis. Insertion of fibre 'short-circuits' could then cause upsets in mitosis-control, and hence DNA irregularities. Such UV-control could parallel similar lower-powered Infra-Red control-systems (as considered elsewhere for coaxial myelin; or as portrayed by G.Albrecht-Buehler's online animations etc.); and the traditional short mitochondria seem better suited for this IR task.

  10. Operant behavior to obtain palatable food modifies neuronal plasticity in the brain reward circuit.

    Science.gov (United States)

    Guegan, Thomas; Cutando, Laura; Ayuso, Eduard; Santini, Emanuela; Fisone, Gilberto; Bosch, Fatima; Martinez, Albert; Valjent, Emmanuel; Maldonado, Rafael; Martin, Miquel

    2013-02-01

    Palatability enhances food intake by hedonic mechanisms that prevail over caloric necessities. Different studies have demonstrated the role of endogenous cannabinoids in the mesocorticolimbic system in controlling food hedonic value and consumption. We hypothesize that the endogenous cannabinoid system could also be involved in the development of food-induced behavioral alterations, such as food-seeking and binge-eating, by a mechanism that requires neuroplastic changes in the brain reward pathway. For this purpose, we evaluated the role of the CB1 cannabinoid receptor (CB1-R) in the behavioral and neuroplastic changes induced by operant training for standard, highly caloric or highly palatable isocaloric food using different genetics, viral and pharmacological approaches. Neuroplasticity was evaluated by measuring changes in dendritic spine density in neurons previously labeled with the dye DiI. Only operant training to obtain highly palatable isocaloric food induced neuroplastic changes in neurons of the nucleus accumbens shell and prefrontal cortex that were associated to changes in food-seeking behavior. These behavioral and neuroplastic modifications induced by highly palatable isocaloric food were dependent on the activity of the CB1-R. Neuroplastic changes induced by highly palatable isocaloric food are similar to those produced by some drugs of abuse and may be crucial in the alteration of food-seeking behavior leading to overweight and obesity. Copyright © 2012 Elsevier B.V. and ECNP. All rights reserved.

  11. Transient behavior of redox flow battery connected to circuit based on global phase structure

    Science.gov (United States)

    Mannari, Toko; Hikihara, Takashi

    A Redox Flow Battery (RFB) is one of the promising energy storage systems in power grid. An RFB has many advantages such as a quick response, a large capacity, and a scalability. Due to these advantages, an RFB can operate in mixed time scale. Actually, it has been demonstrated that an RFB can be used for load leveling, compensating sag, and smoothing the output of the renewable sources. An analysis on transient behaviors of an RFB is a key issue for these applications. An RFB is governed by electrical, chemical, and fluid dynamics. The hybrid structure makes the analysis difficult. To analyze transient behaviors of an RFB, the exact model is necessary. In this paper, we focus on a change in a concentration of ions in the electrolyte, and simulate the change with a model which is mainly based on chemical kinetics. The simulation results introduces transient behaviors of an RFB in a response to a load variation. There are found three kinds of typical transient behaviors including oscillations. As results, it is clarified that the complex transient behaviors, due to slow and fast dynamics in the system, arise by the quick response to load.

  12. Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish: cellular organization and neurotransmitters.

    Science.gov (United States)

    Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E

    2009-09-20

    The sense of taste is crucial in an animal's determination as to what is edible and what is not. This gustatory function is especially important in goldfish, who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe, which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons that have radially directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca(++)-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (+/-)-alpha-amino-3-hydroxy- 5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediate neurotransmission between reflex interneurons and vagal motoneurons. Thus, the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system.

  13. Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish Cellular organization and neurotransmitters

    Science.gov (United States)

    Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E.

    2009-01-01

    The sense of taste is crucial in an animal’s determination as to what is edible and what is not. This gustatory function is especially important in goldfish who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons which have radially-directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca++-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (±)-α-amino-3-hydroxy-5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediates neurotransmission between reflex interneurons and vagal motoneurons. Thus the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system. PMID:19598285

  14. Limbic and motor circuits involved in symmetry behavior in Tourette's syndrome

    NARCIS (Netherlands)

    de Vries, F.E.; van den Heuvel, O.A.; Cath, D.C.; Groenewegen, H.J.; van Balkom, A.J.L.M.; Boellaard, R.; Lammertsma, A.A.; Veltman, D.J.

    2013-01-01

    The need for symmetry and ordering objects related to a "just right"-feeling is a common symptom in Tourette's syndrome (TS) and resembles symmetry behavior in obsessive-compulsive disorder, but its pathophysiology is unknown. We used a symptom provocation paradigm to investigate the neural

  15. Dopamine Modulation of Reunion Behavior in Short and Long Term Marmoset Pairs

    Directory of Open Access Journals (Sweden)

    Sarah B. Carp

    2018-05-01

    Full Text Available One major neurobiological substrate regulating social processes is dopamine (DA. DA is implicated in social behavior in species as diverse as fish and birds, and has an established role in regulating relationships between mates in socially monogamous rodents. Marmoset monkeys display traits associated with social monogamy including high rates of affiliation, biparental care, distress upon separation, and aggression toward strangers; several of these behavioral patterns change throughout the development of relationships. This temporal change may represent changing demands, as pairs are likely to jointly face new experiences (e.g., parenthood throughout pairing. We investigated the role of DA and pairing length on social behavior during reunion after separation from the mate. Marmosets were removed from their home environment and treated with agonists and antagonists for the D1 and D2 receptor subtypes. They were exposed to a novel environment containing an opposite-sex stranger and their pair mate, and then reunited with their mate in the home enclosure. Marmosets in long term pairs exhibited higher levels of food sharing during reunion than marmosets in short term pairs, with females in long term pairs sharing food more than males; no sex difference was observed in short term pairs. Subjects in short term pairs spent more time grooming their mate than receiving grooming during reunion, while marmosets in long term pairs displayed similar amounts of both initiated and received grooming. DA treatment altered pair-level behavior. When females received either a D2 agonist or antagonist, short term pairs spent less time in proximity, compared to when males received the same treatments. In long term pairs, treatment of females with either a D1 agonist or antagonist resulted in pairs spending less time in social proximity than when males were treated. These findings suggest that the function of the DA system in mate behavior may be similar between

  16. Experimental Study on Short Circuit Phenomena in Air Switch of Distribution Line due to Sparkover between Different Poles on Which One Surge Arrester of the Three Ones is Omitted

    Science.gov (United States)

    Sato, Tomoyuki; Uemura, Satoshi; Asakawa, Akira; Yokoyama, Shigeru; Honda, Hideki; Horikoshi, Kazuhiro

    In this study, we experimentally examined the possibility of the internal short circuit of an air switch due to the sparkover between different poles under the condition that no surge arrester exists in neighboring poles and one of three surge arresters is omitted at the pole with an air switch. Experiments at Shiobara Testing Yard and Akagi Testing Center of CRIEPI clarified the following. Fault current may flow via the grounding point of a pole with an air switch and that of the next pole on a different phase from grounded phase of the pole with an air switch. If the low-voltage wire, overhead ground wire or communication wire forms a short circuit between them, ultimately the air switch may burn out. Moreover Fault current continues even if the length of the short-circuit between different poles is increased. Although the increase of the short-circuit length results in the increase of wire impedance, the amount of increase is still small compared with source impedance.

  17. Dopaminergic control of motivation and reinforcement learning: a closed-circuit account for reward-oriented behavior.

    Science.gov (United States)

    Morita, Kenji; Morishima, Mieko; Sakai, Katsuyuki; Kawaguchi, Yasuo

    2013-05-15

    Humans and animals take actions quickly when they expect that the actions lead to reward, reflecting their motivation. Injection of dopamine receptor antagonists into the striatum has been shown to slow such reward-seeking behavior, suggesting that dopamine is involved in the control of motivational processes. Meanwhile, neurophysiological studies have revealed that phasic response of dopamine neurons appears to represent reward prediction error, indicating that dopamine plays central roles in reinforcement learning. However, previous attempts to elucidate the mechanisms of these dopaminergic controls have not fully explained how the motivational and learning aspects are related and whether they can be understood by the way the activity of dopamine neurons itself is controlled by their upstream circuitries. To address this issue, we constructed a closed-circuit model of the corticobasal ganglia system based on recent findings regarding intracortical and corticostriatal circuit architectures. Simulations show that the model could reproduce the observed distinct motivational effects of D1- and D2-type dopamine receptor antagonists. Simultaneously, our model successfully explains the dopaminergic representation of reward prediction error as observed in behaving animals during learning tasks and could also explain distinct choice biases induced by optogenetic stimulation of the D1 and D2 receptor-expressing striatal neurons. These results indicate that the suggested roles of dopamine in motivational control and reinforcement learning can be understood in a unified manner through a notion that the indirect pathway of the basal ganglia represents the value of states/actions at a previous time point, an empirically driven key assumption of our model.

  18. Decoupling the short- and long-term behavior of stochastic volatility

    DEFF Research Database (Denmark)

    Bennedsen, Mikkel; Lunde, Asger; Pakkanen, Mikko

    behavior) from long memory and persistence (long-term behavior) in a simple and parsimonious way, which allows us to successfully model volatility at all intraday time scales. Our prime model is based on the so-called Brownian semistationary process and we derive a number of theoretical properties...... measures of close to two thousand individual US equities, we find that both roughness and persistence appear to be universal properties of volatility. Inspired by the empirical findings, we introduce a new class of continuous-time stochastic volatility models, capable of decoupling roughness (short-term...

  19. The short-circuit test results of 6.9 kV/2.3 kV 400 kVA-class YBCO model transformer with fault current limiting function

    International Nuclear Information System (INIS)

    Tomioka, A.; Bohno, T.; Kakami, S.; Isozaki, M.; Watanabe, K.; Toyama, K.; Sugiyama, S.; Konno, M.; Gosho, Y.; Okamoto, H.; Hayashi, H.; Tsutsumi, T.; Iwakuma, M.; Saito, T.; Tanabe, K.; Shiohara, Y.

    2013-01-01

    Highlights: ► We manufactured the 400 kV A-class YBCO model transformer with FCL function. ► Short-circuit test was performed by applying 6.9 kV on primary side. ► The short-circuit current was limited to 174 A for a prospective current of 559 A. ► It agreed with the design and we also confirmed the I c did not degrade. ► The results suggest the possibility to design YBCO transformers with FCL function. -- Abstract: We are developing an elemental technology for 66/6.9 kV 20 MVA-class superconducting power transformer with fault current limiting function. In order to obtain the characteristics of YBCO conductor when the AC over current supplied to the conductor, the model coils were manufactured with YBCO tapes and tested. Based on these results, we manufactured the 6.9 kV/2.3 kV 400 kVA-class YBCO model transformer with fault current limiting function and performed short-circuit test. At the 0.25 s after short-circuit, the short-circuit current of primary winding was limited to about 174 A for a prospective current of 559 A. It was consistent with the design. The I–V characteristics of the winding did not change before and after the test. We consider the model transformer to be able to withstand AC over-current with the function of current limiting. The results suggest the possibility to design YBCO superconducting transformers with fault current limiting function for practical power grid

  20. Probing the short range behavior of nuclei with high PT photo- and electro-nuclear reactions

    International Nuclear Information System (INIS)

    Laget, J.M.

    1990-01-01

    The short range behavior of the nucleus and the use of the nucleus as a filter are studied. Special emphasis is given to photon and hadron induced reactions. The components of the nuclear wave function are described. The evidences of hard scattering processes in reactions induced by real photons as well as by hadrons on free nucleus are reviewed. The spin observables are also investigated. The perspectives opened by these studies in the nuclear environment are considered

  1. Introducing a Short Measure of Shared Servant Leadership Impacting Team Performance through Team Behavioral Integration

    OpenAIRE

    Sousa, Milton; Van Dierendonck, Dirk

    2016-01-01

    textabstractThe research reported in this paper was designed to study the influence of shared servant leadership on team performance through the mediating effect of team behavioral integration, while validating a new short measure of shared servant leadership. A round-robin approach was used to collect data in two similar studies. Study 1 included 244 undergraduate students in 61 teams following an intense HRM business simulation of 2 weeks. The following year, study 2 included 288 students i...

  2. May functional imaging be helpful for behavioral assessment in children? Regions of motor and associative cortico-subcortical circuits can be differentiated by laterality and rostrality

    Directory of Open Access Journals (Sweden)

    Julia M. August

    2015-06-01

    Full Text Available Background: Cortico-subcortical circuits are organized into the sensorimotor, associative and limbic loop. These neuronal preconditions play an important role regarding the understanding and treatment of behavioral problems in children. Differencing evidence argues for a lateralized organization of the sensorimotor loop and a bilateral (i.e. non-lateralized organization of the associative loop. However, a firm behavioral-neurobiological distinction of these circuits has been difficult, specifically in children. Objectives: Thus, the aim was a comprehensive functional visualization and differentiation of the sensorimotor and the associative circuit during childhood. As a new approach, laterality and rostrality features were used to distinguish between the two circuits within one single motor task. Methods: 24 healthy boys performed self-paced index finger tapping with each hand separately during functional magnetic resonance imaging at 3 Tesla. Results: A contrast analysis for left against right hand movement revealed lateralized activation in typical sensorimotor regions such as primary sensorimotor cortex, caudal supplementary motor area (SMA, caudal putamen and thalamus. A conjunction analysis confirmed bilateral involvement of known associative regions including pre-SMA, rostral SMA and rostral putamen. Conclusion: A functional visualization of two distinct corticostriatal circuits is provided in childhood. Both, the sensorimotor and associative circuit may be discriminated by their laterality characteristics already in minors. Additionally, the results support the concept of a modified functional subdivision of the SMA in a rostral (associative and caudal (motor part. A further development of this approach might help to nurture behavioral assessment and neurofeedback training in child mental health.

  3. Fast Calculation Model and Theoretical Analysis of Rotor Unbalanced Magnetic Pull for Inter-Turn Short Circuit of Field Windings of Non-Salient Pole Generators

    Directory of Open Access Journals (Sweden)

    Guangtao Zhang

    2017-05-01

    Full Text Available Inter-turn short circuit of field windings (ISCFW may cause the field current of a generator to increase, output reactive power to decrease, and unit vibration to intensify, seriously affecting its safe and stable operation. Full integration of mechanical and electrical characteristics can improve the sensitivity of online monitoring, and detect the early embryonic period fault of small turns. This paper studies the calculations and variations of unbalanced magnetic pull (UMP, of which the excitation source of rotor vibration is the basis and key to online fault monitoring. In grid load operation, ISCFW are first calculated with the multi-loop method, so as to obtain the numerical solutions of the stator and the rotor currents during the fault. Next, the air-gap magnetic field of the ISCFW is analyzed according to the actual composition modes of the motor loops in the fault, so as to obtain the analytic expressions of the air-gap magnetic motive force (MMF and magnetic density. The UMP of the rotor is obtained by solving the integral of the Maxwell stress. The correctness of the electric quantity calculation is verified by the ISCFW experiment, conducted in a one pair-pole non-salient pole model machine. On this basis, comparing the simulation analysis with the calculation results of the model in this paper not only verifies the accuracy of the electromagnetic force calculation, but also proves that the latter has the advantages of a short time consumption and high efficiency. Finally, the influencing factors and variation law of UMP are analyzed by means of an analytic model. This develops a base for the online monitoring of ISCFW with the integration of mechanical and electrical information.

  4. Magnetic electrospun short nanofibers wrapped graphene oxide as a promising biomaterials for guiding cellular behavior.

    Science.gov (United States)

    Feng, Zhang-Qi; Shi, Chuanmei; Zhao, Bin; Wang, Ting

    2017-12-01

    Magnetic particles show extremely wide application prospects in the biomedical field, particularly in the success of cellular manipulation, drug delivery systems, magnetic hyperthermia and NRI contrast enhancement. Graphene oxide with functional groups has a promising biological effect. In this work, we develop magnetic short-fibers wrapped graphene oxide for guiding cellular behavior with the aid of high-speed shear of nanofibers fabricated through electrospinning technique. The diameter and the length of short-fibers are about 300nm and 80μm, respectively. The short-fibers exhibit superior magnetic properties (saturation magnetization value: 50.33emu/g), which has a strong response appearance to the NdFeB magnet. SEM images and laser confocal images display that there has an extremely tight adhesion between the short-fibers wrapped graphene oxide and cells. The control of cell-fibers structure behavior can be realized by applying external magnet. The results may provide an attractive perspective on the treatment of disease with magnetic field. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Oscillator circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for oscillator circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listing

  6. Measuring circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for measuring circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listings

  7. Back-reactions, short-circuits, leaks and other energy wasteful reactions in biological electron transfer: redox tuning to survive life in O(2).

    Science.gov (United States)

    Rutherford, A William; Osyczka, Artur; Rappaport, Fabrice

    2012-03-09

    The energy-converting redox enzymes perform productive reactions efficiently despite the involvement of high energy intermediates in their catalytic cycles. This is achieved by kinetic control: with forward reactions being faster than competing, energy-wasteful reactions. This requires appropriate cofactor spacing, driving forces and reorganizational energies. These features evolved in ancestral enzymes in a low O(2) environment. When O(2) appeared, energy-converting enzymes had to deal with its troublesome chemistry. Various protective mechanisms duly evolved that are not directly related to the enzymes' principal redox roles. These protective mechanisms involve fine-tuning of reduction potentials, switching of pathways and the use of short circuits, back-reactions and side-paths, all of which compromise efficiency. This energetic loss is worth it since it minimises damage from reactive derivatives of O(2) and thus gives the organism a better chance of survival. We examine photosynthetic reaction centres, bc(1) and b(6)f complexes from this view point. In particular, the evolution of the heterodimeric PSI from its homodimeric ancestors is explained as providing a protective back-reaction pathway. This "sacrifice-of-efficiency-for-protection" concept should be generally applicable to bioenergetic enzymes in aerobic environments. Copyright © 2012 Federation of European Biochemical Societies. All rights reserved.

  8. Effects of tetrodotoxin and ion replacements on the short-circuit current induced by Escherichiacoli heat stable enterotoxin across small intestine of the gerbil (Gerbillus cheesmani

    Directory of Open Access Journals (Sweden)

    Fawzia Yaqoub Al-Balool

    2004-03-01

    Full Text Available The effects of mucosally added Escherichia coli heat stable enterotoxin (STa 30 ng ml-1 on the basal short-circuit current (Isc in µA cm-2 across stripped and unstripped sheets of jejuna and ilea taken from fed, starved (4 days, water ad lib and undernourished (50% control food intake for 21 days gerbil (Gerbillus cheesmani were investigated. The effect of neurotoxin tetrodotoxin (TTX 10 µM and the effects of replacing chloride by gluconate or the effects of removing bicarbonate from bathing buffers on the maximum increase in Isc induced by STa were also investigated. The maximum increase in Isc which resulted from the addition of STa were significantly higher in jejuna and ilea taken from starved and undernourished gerbils when compared with the fed control both using stripped and unstripped sheets. In the two regions of the small intestine taken from fed and starved animals TTX reduced the maximum increase in Isc induced by STa across unstripped sheets only. Moreover in jejuna and ilea taken from undernourished gerbils TTX reduced significantly the maximum increase in Isc induced by STa across stripped and unstripped sheets. Replacing chloride by gluconate decreased the maximum increase in Isc induced by STa across jejuna and ilea taken from undernourished gerbils only. Removing bicarbonates from bathing buffer decreased the maximum increase in Isc across the jejuna and ilea taken from starved and undernourished gerbils.

  9. Calculations of the displacement damage and short-circuit current degradation in proton irradiated (AlGa)As-GaAs solar cells

    Science.gov (United States)

    Yeh, C. S.; Li, S. S.; Loo, R. Y.

    1987-01-01

    A theoretical model for computing the displacement damage defect density and the short-circuit current (I sub sc) degradation in proton-irradiated (AlGa)As-GaAs p-n junction solar cells is presented. Assumptions were made with justification that the radiation induced displacement defects form an effective recombination center which controls the electron and hole lifetimes in the junction space charge region and in the n-GaAs active layer of the irradiated GaAs p-n junction cells. The degradation of I sub sc in the (AlGa)As layer was found to be negligible compared to the total degradation. In order to determine the I sub sc degradation, the displacement defect density, path length, range, reduced energy after penetrating a distance x, and the average number of displacements formed by one proton scattering event were first calculated. The I sub sc degradation was calculated by using the electron capture cross section in the p-diffused layer and the hole capture cross section in the n-base layer as well as the wavelength dependent absorption coefficients. Excellent agreement was found between the researchers calculated values and the measured I sub sc in the proton irradiated GaAs solar cells for proton energies of 100 KeV to 10 MeV and fluences from 10 to the 10th power p/square cm to 10 to the 12th power p/square cm.

  10. The short circuit current improvement in P3HT:PCBM based polymer solar cell by introducing PSBTBT as additional electron donor.

    Science.gov (United States)

    Sun, Lu; Shen, Liang; Mengd, Fanxu; Xu, Peng; Guo, Wenbin; Ruan, Shengping

    2014-05-01

    Here we demonstrate the influence of electron-donating polymer addition on the performance of poly(3-hexylthiophene) (P3HT):1 -(3-methoxycarbonyl)-propyl-1-phenyl-(6,6) C61 (PCBM) solar cells. Poly[(4,42-bis(2-ethylhexyl) dithieno [3,2-b:22,32-d] silole)-2,6-diylalt-(2,1,3-benzothiadiazole)-4,7-diyl] (PSBTBT) was chosen as the electron-donating polymer to improve the short circuit current (J(sc)) due to its distinct absorption in the near-IR range and similar HOMO level with that of P3HT. In the study, we found that J(sc) was improved for ternary blend (P3HT:PSBTBT:PCBM) solar cells. The dependence of device performance was investigated. J(sc) got decreased with increasing the ratio of PSBTBT. Result showed that J(sc) of ternary blend solar cells was improved greatly after thermal annealing at 150 degrees C, close to that of the binary blend (PSBTBT:PCBM) solar cells.

  11. Robust Diagnosis Method Based on Parameter Estimation for an Interturn Short-Circuit Fault in Multipole PMSM under High-Speed Operation.

    Science.gov (United States)

    Lee, Jewon; Moon, Seokbae; Jeong, Hyeyun; Kim, Sang Woo

    2015-11-20

    This paper proposes a diagnosis method for a multipole permanent magnet synchronous motor (PMSM) under an interturn short circuit fault. Previous works in this area have suffered from the uncertainties of the PMSM parameters, which can lead to misdiagnosis. The proposed method estimates the q-axis inductance (Lq) of the faulty PMSM to solve this problem. The proposed method also estimates the faulty phase and the value of G, which serves as an index of the severity of the fault. The q-axis current is used to estimate the faulty phase, the values of G and Lq. For this reason, two open-loop observers and an optimization method based on a particle-swarm are implemented. The q-axis current of a healthy PMSM is estimated by the open-loop observer with the parameters of a healthy PMSM. The Lq estimation significantly compensates for the estimation errors in high-speed operation. The experimental results demonstrate that the proposed method can estimate the faulty phase, G, and Lq besides exhibiting robustness against parameter uncertainties.

  12. Stator Vibration Characteristic Identification of Turbogenerator among Single and Composite Faults Composed of Static Air-Gap Eccentricity and Rotor Interturn Short Circuit

    Directory of Open Access Journals (Sweden)

    Yu-Ling He

    2016-01-01

    Full Text Available This paper investigates the radial stator vibration characteristics of turbogenerator under the static air-gap eccentricity (SAGE fault, the rotor interturn short circuit (RISC fault, and the composite faults (CFs composed of SAGE and RISC, respectively. Firstly, the impact of the faulty types on the magnetic flux density (MFD is analyzed, based on which the detailed expressions of the magnetic pull per unit area (MPPUA on the stator under different performing conditions are deduced. Then, numerical FEM simulations based on Ansoft and an experimental study are carried out, taking the SDF-9 type fault simulating generator as the study object. It is shown that SAGE will increase the stator vibration at 2f (f is the electrical frequency which already exists even in normal condition, while RISC and CF will bring in stator vibrations at f, 2f, 3f, and 4f at the same time. The vibration amplitudes under CF are larger than those under RISC. As SAGE increases, the vibration amplitudes of each harmonic component under CF will all be increased, while the development of RISC will decrease the 2nd harmonic vibration but meanwhile increase the 4th harmonic vibration. The achievements of this paper are beneficial for fault identification and condition monitoring of the turbogenerator.

  13. Short-term exposure to gold nanoparticle suspension impairs swimming behavior in a widespread calanoid copepod.

    Science.gov (United States)

    Michalec, François-Gaël; Holzner, Markus; Barras, Alexandre; Lacoste, Anne-Sophie; Brunet, Loïc; Lee, Jae-Seong; Slomianny, Christian; Boukherroub, Rabah; Souissi, Sami

    2017-09-01

    Calanoid copepods play an important role in the functioning of marine and brackish ecosystems. Information is scarce on the behavioral toxicity of engineered nanoparticles to these abundant planktonic organisms. We assessed the effects of short-term exposure to nonfunctionalized gold nanoparticles on the swimming behavior of the widespread estuarine copepod Eurytemora affinis. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of males, ovigerous and non-ovigerous females. We quantified changes in their swimming activity and in the kinematics and geometrical properties of their motion, three important descriptors of the motility patterns of zooplankters. In females, exposure to gold nanoparticles in suspension (11.4 μg L -1 ) for 30 min caused depressed activity and lower velocity and acceleration, whereas the same exposure caused minimal effects in males. This response differs clearly from the hyperactive behavior that is commonly observed in zooplankters exposed to pollutants, and from the generally lower sensitivity of female copepods to toxicants. Accumulation of gold nanoparticles on the external appendages was not observed, precluding mechanical effects. Only very few nanoparticles appeared sporadically in the inner part of the gut in some samples, either as aggregates or as isolated nanoparticles, which does not suggest systemic toxicity resulting from pronounced ingestion. Hence, the precise mechanisms underlying the behavioral toxicity observed here remain to be elucidated. These results demonstrate that gold nanoparticles can induce marked behavioral alterations at very low concentration and short exposure duration. They illustrate the applicability of swimming behavior as a suitable and sensitive endpoint for investigating the toxicity of nanomaterials present in estuarine and marine environments. Changes in swimming behavior may impair the ability of planktonic copepods to interact with their environment

  14. Single-Cell Memory Regulates a Neural Circuit for Sensory Behavior.

    Science.gov (United States)

    Kobayashi, Kyogo; Nakano, Shunji; Amano, Mutsuki; Tsuboi, Daisuke; Nishioka, Tomoki; Ikeda, Shingo; Yokoyama, Genta; Kaibuchi, Kozo; Mori, Ikue

    2016-01-05

    Unveiling the molecular and cellular mechanisms underlying memory has been a challenge for the past few decades. Although synaptic plasticity is proven to be essential for memory formation, the significance of "single-cell memory" still remains elusive. Here, we exploited a primary culture system for the analysis of C. elegans neurons and show that a single thermosensory neuron has an ability to form, retain, and reset a temperature memory. Genetic and proteomic analyses found that the expression of the single-cell memory exhibits inter-individual variability, which is controlled by the evolutionarily conserved CaMKI/IV and Raf pathway. The variable responses of a sensory neuron influenced the neural activity of downstream interneurons, suggesting that modulation of the sensory neurons ultimately determines the behavioral output in C. elegans. Our results provide proof of single-cell memory and suggest that the individual differences in neural responses at the single-cell level can confer individuality. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Short and long-lasting behavioral consequences of agonistic encounters between male Drosophila melanogaster.

    Science.gov (United States)

    Trannoy, Séverine; Penn, Jill; Lucey, Kenia; Popovic, David; Kravitz, Edward A

    2016-04-26

    In many animal species, learning and memory have been found to play important roles in regulating intra- and interspecific behavioral interactions in varying environments. In such contexts, aggression is commonly used to obtain desired resources. Previous defeats or victories during aggressive interactions have been shown to influence the outcome of later contests, revealing loser and winner effects. In this study, we asked whether short- and/or long-term behavioral consequences accompany victories and defeats in dyadic pairings between male Drosophila melanogaster and how long those effects remain. The results demonstrated that single fights induced important behavioral changes in both combatants and resulted in the formation of short-term loser and winner effects. These decayed over several hours, with the duration depending on the level of familiarity of the opponents. Repeated defeats induced a long-lasting loser effect that was dependent on de novo protein synthesis, whereas repeated victories had no long-term behavioral consequences. This suggests that separate mechanisms govern the formation of loser and winner effects. These studies aim to lay a foundation for future investigations exploring the molecular mechanisms and circuitry underlying the nervous system changes induced by winning and losing bouts during agonistic encounters.

  16. Pacing Behavior and Tactical Positioning in 500- and 1000-m Short-Track Speed Skating.

    Science.gov (United States)

    Noorbergen, Olaf S; Konings, Marco J; Micklewright, Dominic; Elferink-Gemser, Marije T; Hettinga, Florentina J

    2016-09-01

    To explore pacing behavior and tactical positioning during the shorter 500- and 1000-m short-track competitions. Lap times and intermediate rankings of elite 500- and 1000-m short-track-skating competitors were collected over the 2012-13 season. First, lap times were analyzed using a MANOVA, and for each lap, differences between sex, race type, final ranking, and stage of competition were determined. Second, Kendall tau-b correlations were used to assess relationships between intermediate and final rankings. In addition, intermediate rankings of the winner of each race were examined. Top-placed athletes appeared faster than bottom-placed athletes in every lap in the 500-m, while in the 1000-m no differences were found until the final 4 laps (P < .05). Correlations between intermediate and final rankings were already high at the beginning stages of the 50-m (lap 1: r = .59) but not for the 1000-m (lap 1: r = .21). Although 500- and 1000-m short-track races are both relatively short, fundamental differences in pacing behavior and tactical positioning were found. A fast-start strategy seems to be optimal for 500-m races, while the crucial segment in 1000-m races seems to be from the 6th lap to the finish line (ie, after ± 650 m). These findings provide evidence to suggest that athletes balance between choosing an energetically optimal profile and the tactical and positional benefits that play a role when riding against an opponent, as well as contributing to developing novel insights in exploring athletic behavior when racing against opponents.

  17. Reconciling long-term cultural diversity and short-term collective social behavior.

    Science.gov (United States)

    Valori, Luca; Picciolo, Francesco; Allansdottir, Agnes; Garlaschelli, Diego

    2012-01-24

    An outstanding open problem is whether collective social phenomena occurring over short timescales can systematically reduce cultural heterogeneity in the long run, and whether offline and online human interactions contribute differently to the process. Theoretical models suggest that short-term collective behavior and long-term cultural diversity are mutually excluding, since they require very different levels of social influence. The latter jointly depends on two factors: the topology of the underlying social network and the overlap between individuals in multidimensional cultural space. However, while the empirical properties of social networks are intensively studied, little is known about the large-scale organization of real societies in cultural space, so that random input specifications are necessarily used in models. Here we use a large dataset to perform a high-dimensional analysis of the scientific beliefs of thousands of Europeans. We find that interopinion correlations determine a nontrivial ultrametric hierarchy of individuals in cultural space. When empirical data are used as inputs in models, ultrametricity has strong and counterintuitive effects. On short timescales, it facilitates a symmetry-breaking phase transition triggering coordinated social behavior. On long timescales, it suppresses cultural convergence by restricting it within disjoint groups. Moreover, ultrametricity implies that these results are surprisingly robust to modifications of the dynamical rules considered. Thus the empirical distribution of individuals in cultural space appears to systematically optimize the coexistence of short-term collective behavior and long-term cultural diversity, which can be realized simultaneously for the same moderate level of mutual influence in a diverse range of online and offline settings.

  18. Predicting short-term weight loss using four leading health behavior change theories

    Directory of Open Access Journals (Sweden)

    Barata José T

    2007-04-01

    Full Text Available Abstract Background This study was conceived to analyze how exercise and weight management psychosocial variables, derived from several health behavior change theories, predict weight change in a short-term intervention. The theories under analysis were the Social Cognitive Theory, the Transtheoretical Model, the Theory of Planned Behavior, and Self-Determination Theory. Methods Subjects were 142 overweight and obese women (BMI = 30.2 ± 3.7 kg/m2; age = 38.3 ± 5.8y, participating in a 16-week University-based weight control program. Body weight and a comprehensive psychometric battery were assessed at baseline and at program's end. Results Weight decreased significantly (-3.6 ± 3.4%, p Conclusion The present models were able to predict 20–30% of variance in short-term weight loss and changes in weight management self-efficacy accounted for a large share of the predictive power. As expected from previous studies, exercise variables were only moderately associated with short-term outcomes; they are expected to play a larger explanatory role in longer-term results.

  19. Validation of a short Korean version of the UPPS-P Impulsive Behavior Scale.

    Science.gov (United States)

    Lim, Sun Young; Kim, Seog Ju

    2018-04-23

    The purpose of the present study was to validate a Korean version of the short UPPS-P Impulsive Behavior Scale (UPPS-P). This study included 724 undergraduate students who completed the following questionnaires: the Korean UPPS-P, Beck Depression Inventory, State-Trait Anxiety Inventory, Eating Disorder Inventory-2, Alcohol Use Disorder Identification Test, and Canadian Problem Gambling Index. A confirmatory factor analysis supported a 5-factor interrelated model. The internal consistency coefficients for the 5 factors of the short Korean UPPS-P were acceptable (.65-.78 across the subscales), and the subscales of the short Korean UPPS-P were strongly correlated with the long UPPS-P subscales. External validity was demonstrated by associations between the subfactors of impulsivity and various psychopathologies, including depression, anxiety, binge eating, alcohol abuse, and gambling. The present results indicate that the short Korean version of the UPPS-P may be a useful and reliable alternative to the original long-form UPPS-P. © 2018 John Wiley & Sons Australia, Ltd.

  20. Mechanical behavior and fatigue performance of SMA short fiber reinforced MMC

    Science.gov (United States)

    Al-Matar, Basem Jawad

    The mechanical behavior and performance of Shape Memory Alloy (SMA) short fiber NiTi reinforced Al was experimentally investigated for monotonic and fatigue test Al 6061 NiTi-SiC T6 was superior to unreinforced materials as well as to the reinforced Al T4. Taya three-dimensional model was performed on the monotonic tensile test at room temperature. It showed good agreement with experimental results. In order to utilize the compressive criterion for SMA, the NiTi reinforced Al composite was cooled at -10°C and prestrained at 1.2%. Beyond this limit composite suffered from damage. The net enhancement of SMA effect was around 10 MPa on composite yield stress. Results showed that the elastic constant for the composite did not change with loading and unloading suggesting that the inelastic behavior is plasticity. Further investigation on the inelastic behavior model as damage and/or plasticity by evaluating Poisson's ratio during loading was carried out by Adaptive Image Correlation Technique for Full-Field Strain Measurement. Poisson's ratio increased from around 0.33 to 0.5 demonstrating that it is plasticity that is responsible for the inelastic behavior. Scanning electron microscopy was also used and confirmed model results. The overall damage-behavior was quantified in terms of the post fatigue failure strength for low-cycle fatigue tests. Power law model was best to fit experimental findings.

  1. Bumetanide increases Cl--dependent short-circuit current in late distal colon: Evidence for the presence of active electrogenic Cl- absorption.

    Science.gov (United States)

    Tang, Lieqi; Fang, Xiefan; Winesett, Steven P; Cheng, Catherine Y; Binder, Henry J; Rivkees, Scott A; Cheng, Sam X

    2017-01-01

    Mammalian colonic epithelia consist of cells that are capable of both absorbing and secreting Cl-. The present studies employing Ussing chamber technique identified two opposing short-circuit current (Isc) responses to basolateral bumetanide in rat distal colon. Apart from the transepithelial Cl--secretory Isc in early distal colon that was inhibited by bumetanide, bumetanide also stimulated Isc in late distal colon that had not previously been identified. Since bumetanide inhibits basolateral Na+-K+-2Cl- cotransporter (NKCC) in crypt cells and basolateral K+-Cl- cotransporter (KCC) in surface epithelium, we proposed this stimulatory Isc could represent a KCC-mediated Cl- absorptive current. In support of this hypothesis, ion substitution experiments established Cl- dependency of this absorptive Isc and transport inhibitor studies demonstrated the involvement of an apical Cl- conductance. Current distribution and RNA sequencing analyses revealed that this Cl- absorptive Isc is closely associated with epithelial Na+ channel (ENaC) but is not dependent on ENaC activity. Thus, inhibition of ENaC by 10 μM amiloride or benzamil neither altered the direction nor its activity. Physiological studies suggested that this Cl- absorptive Isc senses dietary Cl- content; thus when dietary Cl- was low, Cl- absorptive Isc was up-regulated. In contrast, when dietary Cl- was increased, Cl- absorptive Isc was down-regulated. We conclude that an active Cl- extrusion mechanism exists in ENaC-expressing late distal colon and likely operates in parallel with ENaC to facilitate NaCl absorption.

  2. Introducing a Short Measure of Shared Servant Leadership Impacting Team Performance through Team Behavioral Integration

    Science.gov (United States)

    Sousa, Milton; Van Dierendonck, Dirk

    2016-01-01

    The research reported in this paper was designed to study the influence of shared servant leadership on team performance through the mediating effect of team behavioral integration, while validating a new short measure of shared servant leadership. A round-robin approach was used to collect data in two similar studies. Study 1 included 244 undergraduate students in 61 teams following an intense HRM business simulation of 2 weeks. The following year, study 2 included 288 students in 72 teams involved in the same simulation. The most important findings were that (1) shared servant leadership was a strong determinant of team behavioral integration, (2) information exchange worked as the main mediating process between shared servant leadership and team performance, and (3) the essence of servant leadership can be captured on the key dimensions of empowerment, humility, stewardship and accountability, allowing for a new promising shortened four-dimensional measure of shared servant leadership. PMID:26779104

  3. The association of 22 Y chromosome short tandem repeat loci with initiative-aggressive behavior.

    Science.gov (United States)

    Yang, Chun; Ba, Huajie; Zhang, Wei; Zhang, Shuyou; Zhao, Hanqing; Yu, Haiying; Gao, Zhiqin; Wang, Binbin

    2018-05-15

    Aggressive behavior represents an important public concern and a clinical challenge to behaviorists and psychiatrists. Aggression in humans is known to have an important genetic basis, so to investigate the association of Y chromosome short tandem repeat (Y-STR) loci with initiative-aggressive behavior, we compared allelic and haplotypic distributions of 22 Y-STRs in a group of Chinese males convicted of premeditated extremely violent crimes (n = 271) with a normal control group (n = 492). Allelic distributions of DYS533 and DYS437 loci differed significantly between the two groups (P initiative aggression in non-psychiatric subjects. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Introducing a Short Measure of Shared Servant Leadership Impacting Team Performance through Team Behavioral Integration.

    Science.gov (United States)

    Sousa, Milton; Van Dierendonck, Dirk

    2015-01-01

    The research reported in this paper was designed to study the influence of shared servant leadership on team performance through the mediating effect of team behavioral integration, while validating a new short measure of shared servant leadership. A round-robin approach was used to collect data in two similar studies. Study 1 included 244 undergraduate students in 61 teams following an intense HRM business simulation of 2 weeks. The following year, study 2 included 288 students in 72 teams involved in the same simulation. The most important findings were that (1) shared servant leadership was a strong determinant of team behavioral integration, (2) information exchange worked as the main mediating process between shared servant leadership and team performance, and (3) the essence of servant leadership can be captured on the key dimensions of empowerment, humility, stewardship and accountability, allowing for a new promising shortened four-dimensional measure of shared servant leadership.

  5. Flying Under the Radar: The Effects of Short-Sale Disclosure Rules on Investor Behavior and Stock Prices

    NARCIS (Netherlands)

    S. Jank (Stephan); C. Roling (Christoph); E. Smajlbegovic (Esad)

    2016-01-01

    textabstractThis paper analyzes how newly introduced transparency requirements for short positions affect investors' behavior and security prices. Employing a unique data set, which contains both public positions above and confidential positions below the regulatory disclosure threshold, we offer

  6. A cholinergic-regulated circuit coordinates the maintenance and bi-stable states of a sensory-motor behavior during Caenorhabditis elegans male copulation.

    Directory of Open Access Journals (Sweden)

    Yishi Liu

    2011-03-01

    Full Text Available Penetration of a male copulatory organ into a suitable mate is a conserved and necessary behavioral step for most terrestrial matings; however, the detailed molecular and cellular mechanisms for this distinct social interaction have not been elucidated in any animal. During mating, the Caenorhabditis elegans male cloaca is maintained over the hermaphrodite's vulva as he attempts to insert his copulatory spicules. Rhythmic spicule thrusts cease when insertion is sensed. Circuit components consisting of sensory/motor neurons and sex muscles for these steps have been previously identified, but it was unclear how their outputs are integrated to generate a coordinated behavior pattern. Here, we show that cholinergic signaling between the cloacal sensory/motor neurons and the posterior sex muscles sustains genital contact between the sexes. Simultaneously, via gap junctions, signaling from these muscles is transmitted to the spicule muscles, thus coupling repeated spicule thrusts with vulval contact. To transit from rhythmic to sustained muscle contraction during penetration, the SPC sensory-motor neurons integrate the signal of spicule's position in the vulva with inputs from the hook and cloacal sensilla. The UNC-103 K(+ channel maintains a high excitability threshold in the circuit, so that sustained spicule muscle contraction is not stimulated by fewer inputs. We demonstrate that coordination of sensory inputs and motor outputs used to initiate, maintain, self-monitor, and complete an innate behavior is accomplished via the coupling of a few circuit components.

  7. Short-distance behavior of the Bethe--Salpeter wave function in the ladder approximation

    International Nuclear Information System (INIS)

    Guth, A.H.; Soper, D.E.

    1975-01-01

    We investigate the short-distance behavior of the (Wick-rotated) Bethe--Salpeter wave function for the two spin-1/2 quarks bound by the exchange of a massive vector meson. We use the ladder-model kernel, which has the same p -4 scaling behavior as the true kernel in a theory with a fixed point of the renormalization group at g not equal to 0. For a bound state with the quantum numbers of the pion, the leading asymptotic behavior is chi (q/sup μ/) approx. cq/sup -4 + epsilon(g)/γ 5 , where epsilon (g) =1- (1-g 2 /π 2 ) 1 / 2 . Our method also provides the full asymptotic series, although it should be noted that the nonleading terms will depend on the nonleading behavior of the ladder-model kernel. A general term has the form cq - /sup a/(lnq)/sup n/phi (q/sup μ/), where c is an unknown constant, a may be integral or nonintegral, n is an integer, and phi (q/sup μ/) is a representation function of the rotation group in four dimensions

  8. Short-Term Dynamics of Behavioral Thermoregulation by Adults of the Grasshopper Melanoplus sanguinipes

    Science.gov (United States)

    O'Neill, Kevin M.; Rolston, Marni G.

    2007-01-01

    The short-term behavioral responses of adult grasshoppers, Melanoplus sanguinipes (F.) (Orthoptera: Acrididae), were examined after they experienced changes in microclimate when beingforced to change positions in their habitat. It was also determined if and when behavioral tactics allowed adults to achieve body temperatures within their preferred range. The preferred or set-point range, here taken as the interquartile range of temperatures selected on a laboratory thermal gradient, was estimated to be 37.4–40.5°C. In the field, adults progressed through a relatively consistent daily sequence of behaviors, basking on the soil early in the day, but moving onto vegetation as temperatures increased. Although basking allowed grasshoppers to maximize body temperature within the available range, as much as 7°C in excess of air temperature, they could not attain preferred body temperatures until soil surface temperatures reach about 35°C. Basking was more effective in grazed than ungrazed pastures due to a lower degree of shading of the soil surface. As soil surface temperatures exceeded 35°C, grasshoppers could achieve body temperatures within the preferred range by moving to the appropriate height on vegetation. These results illustrate the advantage of assessing behavior in the field in relation to preferred body temperatures determined in the laboratory. PMID:20302531

  9. Lasting effects of short-term training on preschoolers' street-crossing behavior.

    Science.gov (United States)

    Albert, Rachel R; Dolgin, Kim G

    2010-03-01

    Can short-term training improve preschoolers' knowledge of road-crossing concepts as well as behavior in a real traffic situation? Forty children, aged four to five years, were assigned to one of four conditions (game, story, song, and control). Each condition participated in four 15-min classroom-based lessons over four weeks. Two assessments measuring knowledge of street-crossing concepts and one assessment measuring behavior on a real street were used to evaluate performance at baseline and one week and six months post-training. Children in all three experimental conditions showed a significant improvement over the control on the two conceptual assessments. Only children in the game condition significantly improved their behavior on the street-crossing assessment. Furthermore, children in all three experimental conditions retained the same levels of improvement at the six-month follow-up. These results demonstrate that one hour of training can create lasting improvements on preschool children's conceptual knowledge of traffic safety and road-crossing behavior on a real street. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Moral Judgments on Short-Term Sexual Behaviors among Chinese College Students: Exploring the Roles of Gender and Physical Attractiveness.

    Science.gov (United States)

    Xiao, Qianguo; Li, Aijuan; Zhu, Yi

    2017-01-01

    This study primarily investigated the effects of gender and physical attractiveness on moral judgments on three typical kinds of short-term sexual behaviors (short-term fling, one-night stand, and hookup) in the Chinese culture context. A total of 120 university student subjects were presented with a series of stereotypically physically attractive (versus physically unattractive) photos before they rated the extent to which each of the three short-term sexual behaviors are morally acceptable. The results showed that male students judged all three behaviors to be more morally acceptable than female students did. Further analyses showed that this gender difference was moderated by the level of physical attractiveness. Under the high attractiveness condition, short-term flings and hookups were judged more morally acceptable by male students than by female students, but this gender difference was not significant under the low attractiveness condition. However, with regard to one-night stands, the data showed that male students judged this type of behavior to be more morally acceptable than did female students under the low attractiveness condition, while this gender difference was not significant under the high attractiveness condition. Thus, these findings further our understanding of how Chinese young people view different types of short-term sexual behaviors, and provide novel evidence regarding how physical attractiveness influences people's moral judgments on short-term sexual behaviors.

  11. Short-term effects of social encouragement on exercise behavior: insights from China's Wanbu network.

    Science.gov (United States)

    Wang, Liuan; Guo, Xitong; Wu, Tianshi; Lv, Lucheng; Zhang, Zhiwei

    2017-07-01

    The objective is to explore the short-term effects of social encouragement on exercise behavior in China. A longitudinal observational study. We collected longitudinal data on exercise and social interactions through public access to the Wanbu network, a large Chinese social network designed to encourage people to walk more. Our data set consisted of 5010 subjects who participated in the network between March 14, 2014, and September 4, 2015, and had at least one social interaction recorded. The data were analyzed using linear regression models relating the number of steps (NS) walked per day to the number of comments (NC), number of thumbs-up (NT), and number of posts (NP) received on the previous day, while adjusting for day of week, quarter of year, and a fixed or random subject effect, with or without a lag term (NS on the previous day) to account for serial correlation. We found that all three social interactions have positive effects on the next day's exercise level. The estimated effect sizes can be ordered as NT > NC > NP for each of the four models considered. The results also indicate that the participants walked less in the first quarter than in the other three quarters and more on weekdays than on weekends, with Monday being the most active day of a week. Social encouragement has positive short-term effects on exercise behavior. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  12. Short-term changes in affective, behavioral, and cognitive components of body image after bariatric surgery.

    Science.gov (United States)

    Williams, Gail A; Hudson, Danae L; Whisenhunt, Brooke L; Stone, Megan; Heinberg, Leslie J; Crowther, Janis H

    2018-04-01

    Many bariatric surgery candidates report body image concerns before surgery. Research has reported post-surgical improvements in body satisfaction, which may be associated with weight loss. However, research has failed to comprehensively examine changes in affective, behavioral, and cognitive body image. This research examined (1) short-term changes in affective, behavioral, and cognitive components of body image from pre-surgery to 1- and 6-months after bariatric surgery, and (2) the association between percent weight loss and these changes. Participants were recruited from a private hospital in the midwestern United States. Eighty-eight females (original N = 123; lost to follow-up: n = 15 at 1-month and n = 20 at 6-months post-surgery) completed a questionnaire battery, including the Body Attitudes Questionnaire, Body Checking Questionnaire, Body Image Avoidance Questionnaire, and Body Shape Questionnaire, and weights were obtained from patients' medical records before and at 1- and 6-months post-surgery. Results indicated significant decreases in body dissatisfaction, feelings of fatness, and body image avoidance at 1- and 6-months after bariatric surgery, with the greatest magnitude of change occurring for body image avoidance. Change in feelings of fatness was significantly correlated with percent weight loss at 6-months, but not 1-month, post-surgery. These findings highlight the importance of examining short-term changes in body image from a multidimensional perspective in the effort to improve postsurgical outcomes. Unique contributions include the findings regarding the behavioral component of body image, as body image avoidance emerges as a particularly salient concern that changes over time among bariatric surgery candidates. Copyright © 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  13. Short-Term Predictive Validity of Cluster Analytic and Dimensional Classification of Child Behavioral Adjustment in School

    Science.gov (United States)

    Kim, Sangwon; Kamphaus, Randy W.; Baker, Jean A.

    2006-01-01

    A constructive debate over the classification of child psychopathology can be stimulated by investigating the validity of different classification approaches. We examined and compared the short-term predictive validity of cluster analytic and dimensional classifications of child behavioral adjustment in school using the Behavior Assessment System…

  14. Bidirectional Long Short-Term Memory Network for Vehicle Behavior Recognition

    Directory of Open Access Journals (Sweden)

    Jiasong Zhu

    2018-06-01

    Full Text Available Vehicle behavior recognition is an attractive research field which is useful for many computer vision and intelligent traffic analysis tasks. This paper presents an all-in-one behavior recognition framework for moving vehicles based on the latest deep learning techniques. Unlike traditional traffic analysis methods which rely on low-resolution videos captured by road cameras, we capture 4K ( 3840 × 2178 traffic videos at a busy road intersection of a modern megacity by flying a unmanned aerial vehicle (UAV during the rush hours. We then manually annotate locations and types of road vehicles. The proposed method consists of the following three steps: (1 vehicle detection and type recognition based on deep neural networks; (2 vehicle tracking by data association and vehicle trajectory modeling; (3 vehicle behavior recognition by nearest neighbor search and by bidirectional long short-term memory network, respectively. This paper also presents experimental results of the proposed framework in comparison with state-of-the-art approaches on the 4K testing traffic video, which demonstrated the effectiveness and superiority of the proposed method.

  15. Measurement Development and Validation of the Family Supportive Supervisor Behavior Short-Form (FSSB-SF)

    Science.gov (United States)

    Hammer, Leslie B.; Kossek, Ellen Ernst; Bodner, Todd; Crain, Tori

    2013-01-01

    Recently, scholars have demonstrated the importance of Family Supportive Supervisor Behaviors (FSSB), defined as behaviors exhibited by supervisors that are supportive of employees’ family roles, in relation to health, well-being, and organizational outcomes. FSSB was originally conceptualized as a multidimensional, superordinate construct with four subordinate dimensions assessed with 14 items: emotional support, instrumental support, role modeling behaviors, and creative work-family management. Retaining one item from each dimension, two studies were conducted to support the development and use of a new FSSB-Short Form (FSSB-SF). Study 1 draws on the original data from the FSSB validation study of retail employees to determine if the results using the 14-item measure replicate with the shorter 4-item measure. Using data from a sample of 823 information technology professionals and their 219 supervisors, Study 2 extends the validation of the FSSB-SF to a new sample of professional workers and new outcome variables. Results from multilevel confirmatory factor analyses and multilevel regression analyses provide evidence of construct and criterion-related validity of the FSSB-SF, as it was significantly related to work-family conflict, job satisfaction, turnover intentions, control over work hours, obligation to work when sick, perceived stress, and reports of family time adequacy. We argue that it is important to develop parsimonious measures of work-family specific support to ensure supervisor support for work and family is mainstreamed into organizational research and practice. PMID:23730803

  16. Maternal separation modulates short-term behavioral and physiological indices of the stress response.

    Science.gov (United States)

    Litvin, Yoav; Tovote, Philip; Pentkowski, Nathan S; Zeyda, Thomas; King, Lanikea B; Vasconcellos, Amy J; Dunlap, Christopher; Spiess, Joachim; Blanchard, D Caroline; Blanchard, Robert J

    2010-07-01

    Early-life stress produces an anxiogenic profile in adulthood, presumably by activating the otherwise quiescent hypothalamic-pituitary-adrenal (HPA) axis during the vulnerable 'stress hyporesponsive period'. While the long-term effects of such early-life manipulations have been extensively characterized, little is known of the short-term effects. Here, we compared the short-term effects of two durations of maternal separation stress and one unseparated group (US) on behavioral and physiological indices of the stress response in rat pups. Separations included 3h on each of 12days, from postnatal day (PND) 2 to 13 (MS2-13) and 3days of daily, 6-h separation from PND11-13 (MS11-13). On PND14 (Experiment 1), both MS2-13 and MS11-13 produced marked reductions in freezing toward an adult male conspecific along with reduced levels of glucocorticoid type 2 (GR) and CRF type-1 (CRF(1)) receptor mRNA in the hippocampus. Group MS2-13 but not MS11-13 produced deficits in stressor-induced corticosterone secretion, accompanied by reductions in body weight. Our results suggest that GR and/or CRF(1) levels, not solely the magnitude of corticosterone secretion, may be involved in the modulation of freezing. In a second experiment, we aimed to extend these findings by testing male and female separated and unseparated pups' unconditioned defensive behaviors to cat odor on PND26, and subsequent cue+context conditioning and extinction throughout postnatal days 27-32. Our results show that maternal separation produced reductions in unconditioned freezing on PND26, with MS2-13 showing stronger deficits than MS11-13. However, separation did not affect any other defensive behaviors. Furthermore, separated rats failed to show conditioned freezing, although they did avoid the no-odor block conditioned cue. There were no sex differences other than weight. We suggest that maternal separation may have produced these changes by disrupting normal development of hippocampal regions involved in

  17. [Association of aggressive behaviors of schizophrenia with short tandem repeats loci].

    Science.gov (United States)

    Yang, Chun; Ba, Huajie; Tan, Xingqi; Zhao, Hanqing; Zhang, Shuyou; Yu, Haiying

    2017-12-10

    To assess the association of short tandem repeats (STRs) loci with aggressive behaviors of schizophrenia. Blood samples from 123 schizophrenic patients with aggressive behaviors and 489 schizophrenic patients without aggressive behaviors were collected. DNA from all samples was amplified with a PowerPlex 21 system and separated by electrophoresis to determine the genotypes and allelic frequencies of 20 STR loci including D3S1368, D1S1656, D6S1043, D13S317, Penta E, D16S639, D18S51, D2S1338, CSF1PO, Penta D, TH01, vWA, D21S11, D7S820, D5S818, TPOX, D8S1179, D12S391, D19S433, and FGA. All of the 20 STR loci have reached Hardy-Weinberg equilibrium in both groups. A significant difference was found in allelic and genotypic frequencies of loci Penta D between the two groups (alleles: P=0.042; genotypes: P=0.014) but not for the remaining 19 loci (P> 0.05). Univariate analysis also showed a significant difference for allele 10 and genotypes 10-12 of Penta D between the two groups (P=0.0027, P=0.0001), with the OR being 1.81 (95%CI: 1.22-2.67) and 4.33 (95%CI: 1.95-9.59), respectively. Penta D may be associated with aggressive behaviors of schizophrenia. Allele 10 and genotypes 10-12 of Penta D may confer a risk for the disease.

  18. Pacing Behavior and Tactical Positioning in 1500-m Short-Track Speed Skating.

    Science.gov (United States)

    Konings, Marco J; Noorbergen, Olaf S; Parry, David; Hettinga, Florentina J

    2016-01-01

    To gain more insight in pacing behavior and tactical positioning in 1500-m short-track speed skating, a sport in which several athletes directly compete in the same race. Lap times and intermediate rankings of elite 1500-m short-track- skating competitors were collected over the season 2012-13 (N = 510, 85 races). Two statistical approaches were used to assess pacing behavior and tactical positioning. First, lap times were analyzed using a MANOVA, and for each lap differences between sex, race type, final rankings, and stage of competition were determined. Second, Kendall tau b correlations were used to assess relationships between intermediate and final rankings. In addition, intermediate rankings of the winner of each race were examined. In 1500 m (13.5 laps of 111.12 m), correlations between intermediate and final ranking gradually increased throughout the race (eg, lap 1, r = .05; lap 7, r = .26; lap 13, r = .85). Moreover, the percentage of race winners skating in the leading position was over 50% during the last 3 laps. Top finishers were faster than bottom-place finishers only during the last 5 laps, with on average 0.1- to 1.5-s faster lap times of the race winners compared with the others during the last 5 laps. Although a fast start led to faster finishing times, top finishers were faster than bottom-placed finishers only during the last 5 laps. Moreover, tactical positioning at 1 of the foremost positions during the latter phase of the race appeared to be a strong determinant of finishing position.

  19. Characterization of the voltage control systems and speed of a synchronous machine of high power for short circuit testing; Caracterizacion de los sistemas de control de voltaje y velocidad de una maquina sincrona de alta potencia para pruebas de corto circuito

    Energy Technology Data Exchange (ETDEWEB)

    Segura Ozuna, Victor Octavio; Hernandez Rodriguez, Isaura Victoria; Alcaide Godinez, Indira Xochiquetzal; Garduno Ramirez, Raul; Montero Cervantes, Julio Cesar [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Ruiz Rodriguez, Genaro; Martinez Torres; Ricardo [CFE-LAPEM, Irapuato, Guanajuato (Mexico)

    2012-07-01

    This paper introduces a characterization of the behavior of the speed and voltage control systems of a special purpose synchronous machine (GCC) based on measuring and monitoring physical signals, and recording of the sampled waveforms. Basically, the GCC supplies the energy to perform high-power short-circuits tests to certify electrical equipment and components, as required by the Comision Federal de Electricidad (CFE) in Mexico. The GCC operates alternately as motor and generator. With the GCC operating as motor, speed control during startup, acceleration, re-acceleration and braking is carried out by a static frequency converter (SFC). Complementary, the voltage controller manipulates excitation power to control terminal voltage when the GCC operates as generator and regulates excitation current when the GCC operates as motor. Compared to conventional voltage regulation systems, which must go off in case of short-circuit, the GCC voltage regulator must keep controlling field excitation to maintain the required line current and terminal voltage during short-circuit tests. Monitoring of physical signals was carried out with a portable data acquisition system based on SCXI and PXI digital platforms. A total of 78 signals were monitored with a 6 kHz sampling rate that was enough to obtain detailed signal waveforms. Data captured was processed and plotted for analysis. The signal graphs show the current real behavior of both, the voltage control system and the speed control system, and constitute a precise characterization of their behavior. [Spanish] Este documento presenta una caracterizacion del comportamiento de los sistemas de control de velocidad y voltaje de una maquina sincrona de proposito especial (GCC) basada en la medicion y monitoreo de senales fisicas, asi como en el registro de las formas de onda muestreadas. Basicamente, la GCC suministra la energia para efectuar pruebas de corto circuito de alta potencia para certificar equipo y componentes

  20. Characteristic interpersonal behavior in dependent and avoidant personality disorder can be observed within very short interaction sequences.

    Science.gov (United States)

    Leising, Daniel; Sporberg, Doreen; Rehbein, Diana

    2006-08-01

    We present a behavior observation study of interpersonal behavior in 96 female subjects, who had been screened for the presence of dependent, avoidant, narcissistic and histrionic personality disorder features. Each subject took part in three short role-plays, taken from assertiveness training. Afterwards, both the subject and her role-play partner judged, how assertive the subject had been. Although observation time was very short, dependent and avoidant subjects could be easily identified from their overly submissive behavior in the role-plays. Histrionic and narcissistic subjects did not show distinctive interpersonal behavior. Contrary to a common belief, higher scores on some personality disorder (PD) scales were positively related to cross-situational variability of behavior. Results are discussed with regard to their implications for clinical diagnostics, therapy and the methodology of personality disorder research in general.

  1. Reorganization of brain function after a short-term behavioral intervention for stuttering.

    Science.gov (United States)

    Lu, Chunming; Zheng, Lifen; Long, Yuhang; Yan, Qian; Ding, Guosheng; Liu, Li; Peng, Danling; Howell, Peter

    2017-05-01

    This study investigated changes in brain function that occurred over a 7-day behavioral intervention for adults who stutter (AWS). Thirteen AWS received the intervention (AWS+), and 13 AWS did not receive the intervention (AWS-). There were 13 fluent controls (FC-). All participants were scanned before and after the intervention. Whole-brain analysis pre-intervention showed significant differences in task-related brain activation between AWS and FC- in the right inferior frontal cortex (IFC) and left middle temporal cortex, but there were no differences between the two AWS groups. Across the 7-day period of the intervention, AWS+ alone showed a significant increase of brain activation in the left ventral IFC/insula. There were no changes in brain function for the other two groups. Further analysis revealed that the change did not correlate with resting-state functional connectivity (RSFC) that AWS showed in the cerebellum (Lu et al., 2012). However, both changes in task-related brain function and RSFC correlated with changes in speech fluency level. Together, these findings suggest that functional reorganization in a brain region close to the left IFC that shows anomalous function in AWS, occurs after a short-term behavioral intervention for stuttering. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Organotins in Neuronal Damage, Brain Function, and Behavior: A Short Review

    Directory of Open Access Journals (Sweden)

    Igor Ferraz da Silva

    2018-01-01

    Full Text Available The consequences of exposure to environmental contaminants have shown significant effects on brain function and behavior in different experimental models. The endocrine-disrupting chemicals (EDC present various classes of pollutants with potential neurotoxic actions, such as organotins (OTs. OTs have received special attention due to their toxic effects on the central nervous system, leading to abnormal mammalian neuroendocrine axis function. OTs are organometallic pollutants with a tin atom bound to one or more carbon atoms. OT exposure may occur through the food chain and/or contaminated water, since they have multiple applications in industry and agriculture. In addition, OTs have been used with few legal restrictions in the last decades, despite being highly toxic. In addition to their action as EDC, OTs can also cross the blood–brain barrier and show relevant neurotoxic effects, as observed in several animal model studies specifically involving the development of neurodegenerative processes, neuroinflammation, and oxidative stress. Thus, the aim of this short review is to summarize the toxic effects of the most common OT compounds, such as trimethyltin, tributyltin, triethyltin, and triphenyltin, on the brain with a focus on neuronal damage as a result of oxidative stress and neuroinflammation. We also aim to present evidence for the disruption of behavioral functions, neurotransmitters, and neuroendocrine pathways caused by OTs.

  3. Feeding the developing brain: Juvenile rats fed diet rich in prebiotics and bioactive milk fractions exhibit reduced anxiety-related behavior and modified gene expression in emotion circuits.

    Science.gov (United States)

    Mika, Agnieszka; Gaffney, Michelle; Roller, Rachel; Hills, Abigail; Bouchet, Courtney A; Hulen, Kristina A; Thompson, Robert S; Chichlowski, Maciej; Berg, Brian M; Fleshner, Monika

    2018-01-30

    Early life nutrition is critical for brain development. Dietary prebiotics and bioactive milk fractions support brain development by increasing plasticity and altering activity in brain regions important for cognition and emotion regulation, perhaps through the gut-microbiome-brain axis. Here we examined the impact of a diet containing prebiotics, lactoferrin, and milk fat globule membrane (test diet) on beneficial gut bacteria, basal gene expression for activity and plasticity markers within brain circuits important for cognition and anxiety, and anxiety-related behavior in the open field. Juvenile male F344 rats were fed the test diet or a calorically matched control diet beginning postnatal day 24. After 4 weeks on diets, rats were sacrificed and brains were removed. Test diet significantly increased mRNA expression for cfos, brain derived neurotropic factor, and the GluN1 subunit of the NMDA receptor in the prefrontal cortex and reduced cfos mRNA within the amygdala. Diet-induced increases in fecal Lactobacillus spp., measured using selective bacterial culture, positively correlated with altered gene expression for cfos and serotonin receptors within multiple brain regions. In a separate cohort of juvenile rats, 4 weeks of the test diet increased time spent in the center of the open field, a behavior indicative of reduced anxiety. These data demonstrate that early life diets containing prebiotics and bioactive milk fractions can adaptively alter genes in neural circuits underlying emotion regulation and decrease anxiety-related behavior. Copyright © 2018. Published by Elsevier B.V.

  4. Corrosion Behavior of Carbon Steel Coated with Octadecylamine in the Secondary Circuit of a Pressurized Water Reactor

    Science.gov (United States)

    Jäppinen, Essi; Ikäläinen, Tiina; Järvimäki, Sari; Saario, Timo; Sipilä, Konsta; Bojinov, Martin

    2017-12-01

    Corrosion and particle deposition in the secondary circuits of pressurized water reactors can be mitigated by alternative water chemistries featuring film-forming amines. In the present work, the corrosion of carbon steel in secondary side water with or without octadecylamine (ODA) is studied by in situ electrochemical impedance spectroscopy, combined with weight loss/gain measurements, scanning electron microscopy and glow-discharge optical emission spectroscopy. The impedance spectra are interpreted using the mixed-conduction model to extract kinetic parameters of oxide growth and metal dissolution through it. From the experimental results, it can be concluded that ODA addition reduces the corrosion rate of both fresh and pre-oxidized carbon steel in secondary circuit significantly by slowing down both interfacial reactions and transport through the oxide layer.

  5. Noise Trauma-Induced Behavioral Gap Detection Deficits Correlate with Reorganization of Excitatory and Inhibitory Local Circuits in the Inferior Colliculus and Are Prevented by Acoustic Enrichment.

    Science.gov (United States)

    Sturm, Joshua J; Zhang-Hooks, Ying-Xin; Roos, Hannah; Nguyen, Tuan; Kandler, Karl

    2017-06-28

    Hearing loss leads to a host of cellular and synaptic changes in auditory brain areas that are thought to give rise to auditory perception deficits such as temporal processing impairments, hyperacusis, and tinnitus. However, little is known about possible changes in synaptic circuit connectivity that may underlie these hearing deficits. Here, we show that mild hearing loss as a result of brief noise exposure leads to a pronounced reorganization of local excitatory and inhibitory circuits in the mouse inferior colliculus. The exact nature of these reorganizations correlated with the presence or absence of the animals' impairments in detecting brief sound gaps, a commonly used behavioral sign for tinnitus in animal models. Mice with gap detection deficits (GDDs) showed a shift in the balance of synaptic excitation and inhibition that was present in both glutamatergic and GABAergic neurons, whereas mice without GDDs showed stable excitation-inhibition balances. Acoustic enrichment (AE) with moderate intensity, pulsed white noise immediately after noise trauma prevented both circuit reorganization and GDDs, raising the possibility of using AE immediately after cochlear damage to prevent or alleviate the emergence of central auditory processing deficits. SIGNIFICANCE STATEMENT Noise overexposure is a major cause of central auditory processing disorders, including tinnitus, yet the changes in synaptic connectivity underlying these disorders remain poorly understood. Here, we find that brief noise overexposure leads to distinct reorganizations of excitatory and inhibitory synaptic inputs onto glutamatergic and GABAergic neurons and that the nature of these reorganizations correlates with animals' impairments in detecting brief sound gaps, which is often considered a sign of tinnitus. Acoustic enrichment immediately after noise trauma prevents circuit reorganizations and gap detection deficits, highlighting the potential for using sound therapy soon after cochlear damage

  6. Resonance circuits for adiabatic circuits

    Directory of Open Access Journals (Sweden)

    C. Schlachta

    2003-01-01

    Full Text Available One of the possible techniques to reduces the power consumption in digital CMOS circuits is to slow down the charge transport. This slowdown can be achieved by introducing an inductor in the charging path. Additionally, the inductor can act as an energy storage element, conserving the energy that is normally dissipated during discharging. Together with the parasitic capacitances from the circuit a LCresonant circuit is formed.

  7. Analytical Analysis and Case Study of Transient Behavior of Inrush Current in Power Transformer for Designing of Efficient Circuit Breakers

    Science.gov (United States)

    Harmanpreet, Singh, Sukhwinder; Kumar, Ashok; Kaur, Parneet

    2010-11-01

    Stability & security are main aspects in electrical power systems. Transformer protection is major issue of concern to system operation. There are many mall-trip cases of transformer protection are caused by inrush current problems. The phenomenon of transformer inrush current has been discussed in many papers since 1958. In this paper analytical analysis of inrush current in a transformer switched on dc and ac supply has been done. This analysis will help in design aspects of circuit breakers for better performance.

  8. Wireless system for location of permanent faults by short circuit current monitoring in electric power distribution network; Sistema wireless para localizacao de faltas permanentes atraves da monitoracao da corrente de curto-circuito em redes de distribuicao de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Machado, A.G.; Correa, A.C.; Machado, R.N. das M.; Ferreira, A.M.D.; Pinto, J.A.C. [Instituto Federal de Educacao, Ciencia e Tecnologia do Para (IFPA), Belem, PA (Brazil)], E-mail: alcidesmachado000@yahoo.com.br; Barra Junior, W. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Tecnologia. Faculdade de Engenharia Eletrica], E-mail: walbarra@ufpa.br

    2009-07-01

    This paper presents the development of an automatic system for permanent short-circuits location in medium voltage (13.8 kV) electric power system distribution feeders, by indirect monitoring of the line current. When a permanent failure occurs, the developed system uses mobile telephony (GSM) text messages (SMS) to inform the power company operation center where the failure most likely took place. With this information in real time, the power company operation center may provide the network restoration in a faster and efficient way. (author)

  9. Relationships between body mass index and short-circuit current in human duodenal and colonic mucosal biopsies. Osbak PS, Bindslev N, Hansen MB. Acta Physiol (Oxf). 2011 Jan;201(1):47-53

    DEFF Research Database (Denmark)

    Osbak, Philip Samuel; Bindslev, Niels; Berner-Hansen, Mark

    2011-01-01

    Aim: Retrospectively, to investigate the relationship between body mass index (BMI) and basal electrogenic transport as measured by short-circuit current (SCC) in human duodenal and colonic mucosal biopsies. Methods: The study included biopsies from mucosa of normal appearance in the sigmoid colon...... and >25 kg m)2). Statistical significance was assessed by the unpaired t-test or Wilcoxon rank-sum test. Correlation coefficients were calculated by Pearson product moment correlation. Results: In colonic biopsies, basal SCC (mean standard deviation) was significantly higher in 59 biopsies from 30...

  10. Short timescale photometric and polarimetric behavior of two BL Lacertae type objects

    International Nuclear Information System (INIS)

    Covino, S.; Baglio, M. C.; Foschini, L.; Sandrinelli, A.; Tavecchio, F.; Treves, A.; Zhang, H.; Barres de Almeida, U.; Bonnoli, G.; Boettcher, M.; Cecconi, M.; D'Ammando, F.; Fabrizio, L. di; Giarrusso, M.; Leone, F.; Lindfors, E.; Lorenzi, V.; Molinari, E.; Paiano, S.; Prandini, E.; Raiteri, C. M.; Stamerra, A.; Tagliaferri, G.

    2015-01-01

    Context. Blazars are astrophysical sources whose emission is dominated by non-thermal processes, typically interpreted as synchrotron and inverse Compton emission. Although the general picture is rather robust and consistent with observations, many aspects are still unexplored. Aims. Polarimetric monitoring can offer a wealth of information about the physical processes in blazars. Models with largely different physical ingredients can often provide almost indistinguishable predictions for the total flux, but usually are characterized by markedly different polarization properties. We explore, with a pilot study, the possibility to derive structural information about the emitting regions of blazars by means of a joint analysis of rapid variability of the total and polarized flux at optical wavelengths. Methods. Short timescale (from tens of seconds to a couple of minutes) optical linear polarimetry and photometry for two blazars, BL Lacertae and PKS 1424+240, was carried out with the PAOLO polarimeter at the 3.6 m Telescopio Nazionale Galileo. Several hours of almost continuous observations were obtained for both sources. Results. Our intense monitoring allowed us to draw strongly different scenarios for BL Lacertae and PKS 1424+240, with the former characterized by intense variability on time-scales from hours to a few minutes and the latter practically constant in total flux. Essentially the same behavior is observed for the polarized flux and the position angle. The variability time-scales turned out to be as short as a few minutes, although involving only a few percent variation of the flux. The polarization variability time-scale is generally consistent with the total flux variability. Total and polarized flux appear to be essentially uncorrelated. However, even during our relatively short monitoring, different regimes can be singled out. Conclusions. No simple scenario is able to satisfactorily model the very rich phenomenology exhibited in our data. As a

  11. Comparison Study of Axial Behavior of RPC-CFRP Short Columns

    Directory of Open Access Journals (Sweden)

    Taghreed Khaleefa Mohammed Ali

    2015-05-01

    Full Text Available In this paper, the axial behaviors of reactive powder     concrete (RPC short  columns confined with carbon fiber reinforced polymer (CFRP were   investigated. All the specimens have square cross section of 100 mm × 100   mm and length of 400 mm with aspect ratio 4. The experimental work consists   of three groups. The first group consists of six specimens of RPC with 2%  micro steel fiber, without ordinary reinforcing steel and confining by zero, one and two layer of CFRP respectively. The second group consists of six    specimens of RPC with 2% micro steel fiber and minimum ordinary reinforcing  steel and confining by zero, one and two layers of CFRP respectively. The third  group consists of four specimens of RPC without micro steel fiber and ordinary  reinforcing steel and confining by one and two layers of CFRP respectively.  Experimental data for strength, longitudinal and lateral displacement and  failure mode were obtained for each test. The toughness (area under the curve  for each test was obtained by using numerical integration. The RPC columns confined with CFRP showed stiffer behavior compared with RPC columns without CFRP. The ultimate load of the RPC columns with 2% micro steel  fiber + two layers of CFRP + minimum ordinary reinforcement were more than that of the RPC columns with 2% micro steel fiber + minimum ordinary   reinforcement and without CFRP by about 1.333.

  12. Electronic circuit encyclopedia 2

    International Nuclear Information System (INIS)

    Park, Sun Ho

    1992-10-01

    This book is composed of 15 chapters, which are amplification of weak signal and measurement circuit audio control and power amplification circuit, data transmission and wireless system, forwarding and isolation, signal converting circuit, counter and comparator, discriminator circuit, oscillation circuit and synthesizer, digital and circuit on computer image processing circuit, sensor drive circuit temperature sensor circuit, magnetic control and application circuit, motor driver circuit, measuring instrument and check tool and power control and stability circuit.

  13. Electronic circuit encyclopedia 2

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Ho

    1992-10-15

    This book is composed of 15 chapters, which are amplification of weak signal and measurement circuit audio control and power amplification circuit, data transmission and wireless system, forwarding and isolation, signal converting circuit, counter and comparator, discriminator circuit, oscillation circuit and synthesizer, digital and circuit on computer image processing circuit, sensor drive circuit temperature sensor circuit, magnetic control and application circuit, motor driver circuit, measuring instrument and check tool and power control and stability circuit.

  14. Dry sliding wear behavior of epoxy composite reinforced with short palmyra fibers

    International Nuclear Information System (INIS)

    Biswal, Somen; Satapathy, Alok

    2016-01-01

    The present work explores the possibility of using palmyra fiber as a replacement for synthetic fiber in conventional polymer composites for application against wear. An attempt has been made in this work to improve the sliding wear resistance of neat epoxy by reinforcing it with short palmyra fibers (SPF). Epoxy composites with different proportions (0, 4, 8 and 12 wt. %) of SPF are fabricated by conventional hand lay-up technique. Dry sliding wear tests are performed on the composite samples using a pin-on-disc test rig as per ASTM G 99-05 standards under various operating parameters. Design of experiment approach based on Taguchi's L16 Orthogonal Arrays is used for the analysis of the wear. This parametric analysis reveals that the SPF content is the most significant factor affecting the wear process followed by the sliding velocity. The sliding wear behavior of these composites under an extensive range of test conditions is predicted by a model based on the artificial neural network (ANN). A well trained ANN has been used to predict the sliding wear response of epoxy based composites over a wide range. (paper)

  15. A short course on functional equations based upon recent applications to the social and behavioral sciences

    CERN Document Server

    Aczél, J

    1987-01-01

    Recently I taught short courses on functional equations at several universities (Barcelona, Bern, Graz, Hamburg, Milan, Waterloo). My aim was to introduce the most important equations and methods of solution through actual (not artifi­ cial) applications which were recent and with which I had something to do. Most of them happened to be related to the social or behavioral sciences. All were originally answers to questions posed by specialists in the respective applied fields. Here I give a somewhat extended version of these lectures, with more recent results and applications included. As previous knowledge just the basic facts of calculus and algebra are supposed. Parts where somewhat more (measure theory) is needed and sketches of lengthier calcula­ tions are set in fine print. I am grateful to Drs. J. Baker (Waterloo, Ont.), W. Forg-Rob (Innsbruck, Austria) and C. Wagner (Knoxville, Tenn.) for critical remarks and to Mrs. Brenda Law for care­ ful computer-typing of the manuscript (in several versions). A...

  16. Evaluation of a Short-term, Cognitive-Behavioral Intervention for Primary Age Children with Anger-Related Difficulties

    Science.gov (United States)

    Cole, Rachel L.; Treadwell, Susanne; Dosani, Sima; Frederickson, Norah

    2013-01-01

    This study evaluated the school-based short-term, cognitive-behavioral group anger management programme, "Learning How to Deal with our Angry Feelings" (Southampton Psychology Service, 2003). Thirteen groups of children aged 7- to 11-years-old were randomly allocated to two different cohorts: One cohort ("n"?=?35) first…

  17. The transfer function method for the evaluation of short-circuit tests and on-site diagnostics of power transformers; Die Uebertragungsfunktion als Methode zur Beurteilung der Stosskurzschlusspruefung und Vor-Ort-Isolationsdiagnose

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.; Feser, K. [Stuttgart Univ. (Germany). Inst. fuer Energieuebertragung und Hochspannungstechnik; Leibfried, T. [Siemens AG, Nuernberg (Germany). Geschaeftsgebiet Leistungstransformatoren; Jaeggi, F. [Aare-Tessin AG fuer Elektrizitaet, Olten (Switzerland)

    1999-03-22

    A short circuit test according to IEC 76-5 was performed on a 125 MVA, 245 kV/53 kV power transformer from the Siemens factory in Nuremberg at the Kema high power laboratory (Arnhem, Netherlands) in March 1997. Thereby, the transfer function method was examined as an additional method for evaluating the short-circuit test. The visual inspection of the transformer after returning to the Nuremberg factory carried out by engineers from Atel and Siemens and representatives of Kema showed no changes of the core and coil assembly. At the Flumenthal substation a second transformer of the same type was installed. Before commissioning, the transfer functions of both transformers have been measured. These measurements provide essential information concerning the comparability of measurements from different transformers and are the basis for measurements to be carried out in the future. (orig.) [Deutsch] Im Maerz 1997 wurde ein 125-MVA-Leistungstranformator aus dem Siemens Transformatorenwerk Nuernberg im Hochleistungslabor der Kema, Arnheim einer Stosskurzschlusspruefung unterzogen. Dabei wurde die Analyse der Uebertragungsfunktion des Transformators als zusaetzliche Methode zur Beurteilung der Stosskurzschlusspruefung untersucht. Der Aktivteil wurde danach im Herstellerwerk begutachtet. Dabei ergaben sich keine Beanstandungen. Im Umspannwerk Flumenthal wurde ein zweiter baugleicher Transformator installiert. Vor der Inbetriebnahme wurden zusaetzliche Vergleichsmessungen an den zwei baugleichen Transformatoren durchgefuehrt. (orig.)

  18. Current-mode minimax circuit

    NARCIS (Netherlands)

    Wassenaar, R.F.

    1992-01-01

    The minimum-maximum (minimax) circuit selects the minimum and maximum of two input currents. Four transistors in matched pairs are operated in the saturation region. Because the behavior of the circuit is based on matched devices and is independent of the relationship between the drain current and

  19. Junction and circuit fabrication

    International Nuclear Information System (INIS)

    Jackel, L.D.

    1980-01-01

    Great strides have been made in Josephson junction fabrication in the four years since the first IC SQUID meeting. Advances in lithography have allowed the production of devices with planar dimensions as small as a few hundred angstroms. Improved technology has provided ultra-high sensitivity SQUIDS, high-efficiency low-noise mixers, and complex integrated circuits. This review highlights some of the new fabrication procedures. The review consists of three parts. Part 1 is a short summary of the requirements on junctions for various applications. Part 2 reviews intergrated circuit fabrication, including tunnel junction logic circuits made at IBM and Bell Labs, and microbridge radiation sources made at SUNY at Stony Brook. Part 3 describes new junction fabrication techniques, the major emphasis of this review. This part includes a discussion of small oxide-barrier tunnel junctions, semiconductor barrier junctions, and microbridge junctions. Part 3 concludes by considering very fine lithography and limitations to miniaturization. (orig.)

  20. OCD-like behavior is caused by dysfunction of thalamo-amygdala circuits and upregulated TrkB/ERK-MAPK signaling as a result of SPRED2 deficiency.

    Science.gov (United States)

    Ullrich, M; Weber, M; Post, A M; Popp, S; Grein, J; Zechner, M; Guerrero González, H; Kreis, A; Schmitt, A G; Üçeyler, N; Lesch, K-P; Schuh, K

    2018-02-01

    Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disease affecting about 2% of the general population. It is characterized by persistent intrusive thoughts and repetitive ritualized behaviors. While gene variations, malfunction of cortico-striato-thalamo-cortical (CSTC) circuits, and dysregulated synaptic transmission have been implicated in the pathogenesis of OCD, the underlying mechanisms remain largely unknown. Here we show that OCD-like behavior in mice is caused by deficiency of SPRED2, a protein expressed in various brain regions and a potent inhibitor of Ras/ERK-MAPK signaling. Excessive self-grooming, reflecting OCD-like behavior in rodents, resulted in facial skin lesions in SPRED2 knockout (KO) mice. This was alleviated by treatment with the selective serotonin reuptake inhibitor fluoxetine. In addition to the previously suggested involvement of cortico-striatal circuits, electrophysiological measurements revealed altered transmission at thalamo-amygdala synapses and morphological differences in lateral amygdala neurons of SPRED2 KO mice. Changes in synaptic function were accompanied by dysregulated expression of various pre- and postsynaptic proteins in the amygdala. This was a result of altered gene transcription and triggered upstream by upregulated tropomyosin receptor kinase B (TrkB)/ERK-MAPK signaling in the amygdala of SPRED2 KO mice. Pathway overactivation was mediated by increased activity of TrkB, Ras, and ERK as a specific result of SPRED2 deficiency and not elicited by elevated brain-derived neurotrophic factor levels. Using the MEK inhibitor selumetinib, we suppressed TrkB/ERK-MAPK pathway activity in vivo and reduced OCD-like grooming in SPRED2 KO mice. Altogether, this study identifies SPRED2 as a promising new regulator, TrkB/ERK-MAPK signaling as a novel mediating mechanism, and thalamo-amygdala synapses as critical circuitry involved in the pathogenesis of OCD.

  1. Influence of ties on the behavior of short reinforced concrete columns strengthened by external CFRP

    Directory of Open Access Journals (Sweden)

    Sarsam Kaiss

    2018-01-01

    Full Text Available An experimental study was carried out to investigate the behavior of normal strength reinforce concret (RC circular short column strengthned with “carbon fiber reinforced polymer (CFRP sheets”. Three series comprising totally of (15 specimens loaded until failure under concentric compresion load. Strengthening was varied by changing the number of CFRP strips, spacing and wrapping methods. The findings of this research can be summarized as follows: for the columns without CFRP, the influence of the tie spacing was significant: compared with 130 mm tie spacing, dropping the spacing to 100 mm and 70 mm increased the load carrying capacity by 18% and 26%, respectively. The columns with less internal confinement (lesser amount of ties were strengthened more significantly by the CFRP than the ones with greater amount of internal ties. As an example of the varying effectiveness of the fully wrapped CFRP, the column with ties at 130 mm was strengthened by 90% with the CFRP. In contrast, the ones with 70 mm spaced ties only increased in strength with CFRP by 66%. Compared with the control specimen (no CFRP, the same amount of CFRP when used as hoop strips led to more strengthening than using CFRP as a spiral strip- the former led to nearly 9% more strengthening than the latter in the case of 130 mm spaced internal steel ties. In the case of 100 mm internal steel ties, the difference (between the hoops & spiral CFRP strengthening is close to 4%. In contrast, there is no difference between the two methods of strengthening in the heavily tied columns (70 mm tied spacing.

  2. What's new about generator circuit breakers

    International Nuclear Information System (INIS)

    Kolarik, P.L.

    1979-01-01

    The need for updating ANSI C37 Standards for AC high-voltage circuit breakers has become necessary because of the increased interest in power circuit breakers for generator application. These circuit breakers, which have continuous current ratings and rated short-circuit currents that are much higher than those presently covered by existing C37 Standards, take on added importance because they are being installed in critical AC power supplies at nuclear power stations

  3. GABAergic Signaling within a Limbic-Hypothalamic Circuit Integrates Social and Anxiety-Like Behavior with Stress Reactivity.

    Science.gov (United States)

    Myers, Brent; Carvalho-Netto, Eduardo; Wick-Carlson, Dayna; Wu, Christine; Naser, Sam; Solomon, Matia B; Ulrich-Lai, Yvonne M; Herman, James P

    2016-05-01

    The posterior hypothalamic nucleus (PH) stimulates autonomic stress responses. However, the role of the PH in behavioral correlates of psychiatric illness, such as social and anxiety-like behavior, is largely unexplored, as is the neurochemistry of PH connectivity with limbic and neuroendocrine systems. Thus, the current study tested the hypothesis that GABAergic signaling within the PH is a critical link between forebrain behavior-regulatory nuclei and the neuroendocrine hypothalamus, integrating social and anxiety-related behaviors with physiological stress reactivity. To address this hypothesis, GABAA receptor pharmacology was used to locally inhibit or disinhibit the PH immediately before behavioral measures of social and anxiety-like behavior in rats. Limbic connectivity of the PH was then established by simultaneous co-injection of anterograde and retrograde tracers. Further, the role of PH GABAergic signaling in neuroendocrine stress responses was tested via inhibition/disinhibition of the PH. These studies determined a prominent role for the PH in the expression of anxiety-related behaviors and social withdrawal. Histological analyses revealed divergent stress-activated limbic input to the PH, emanating predominantly from the prefrontal cortex, lateral septum, and amygdala. PH projections also targeted both parvicellular and magnocellular peptidergic neurons in the paraventricular and supraoptic hypothalamus. Further, GABAA receptor pharmacology determined an excitatory effect of the PH on neuroendocrine responses to stress. These data indicate that the PH represents an important stress-integrative center, regulating behavioral processes and connecting the limbic forebrain with neuroendocrine systems. Moreover, the PH appears to be uniquely situated to have a role in stress-related pathologies associated with limbic-hypothalamic dysfunction.

  4. Optically controllable molecular logic circuits

    International Nuclear Information System (INIS)

    Nishimura, Takahiro; Fujii, Ryo; Ogura, Yusuke; Tanida, Jun

    2015-01-01

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals

  5. A single social defeat induces short-lasting behavioral sensitization to amphetamine

    NARCIS (Netherlands)

    de Jong, JG; Wasilewski, M; van der Vegt, BJ; Buwalda, B; Koolhaas, Jacob

    2005-01-01

    Repeated, intermittent exposure to psychostimulants or stressors results in long-lasting, progressive sensitization of the behavioral effects of a subsequent amphetamine (AMPH) challenge. Although behavioral sensitization has also been observed following a single drug pretreatment, the sensitizing

  6. Modification of severe violent and aggressive behavior among psychiatric inpatients through the use of a short-term token economy.

    Science.gov (United States)

    Park, Jae Soon; Lee, Kyunghee

    2012-12-01

    Meager research has been carried out to determine the effectiveness of the token economy among patients behaving violently in mental hospitals. The purpose of this study was to examine the effectiveness of the Short-Term Token Economy (STTE) on violent behavior among chronic psychiatric in-patients. A nonequivalent control group design method was utilized. Participants in an experimental group (n=22) and control group (n=22) took part in this study from January to April, 2008. Observation on aggressive behavior among male in-patients in one hospital as a baseline was made during the week before the behavior modification program and measurement of aggressive behavior was done using the Overt Aggression Scale (OAS), which includes verbal attacks, property damage and physical attacks. The aggressive behavior scores of the experimental group decreased, those of the control group, scores showed an increase after the eight-week behavior modification program utilizing STTE. The results of the study indicate that STTE is effective in reducing the incidence of aggressive behavior among male in-patients in psychiatric hospitals. The outcome of this study should be helpful in reducing the use of coercive measures or psychoactive medication in controlling the violent behavior among in-patients in hospitals.

  7. Method for determining dynamic short circuit withstand capability of installations in meshed cable MV-networks, during switch on to a fault

    NARCIS (Netherlands)

    Parabirsing, E.N.; Coster, E.J.; Goerdin, S.A.V.

    2013-01-01

    tedin is the Distribution Grid Operator in the western part of the Netherlands and is known to be a "slim network operator" which means that it is only responsible for managing the gas and electricity networks. In this paper a method will be described with which Stedin proved that the dynamic short

  8. Psychological processes in chronic pain: Influences of reward and fear learning as key mechanisms - Behavioral evidence, neural circuits, and maladaptive changes.

    Science.gov (United States)

    Nees, Frauke; Becker, Susanne

    2017-09-07

    In the understanding of chronic pain, hypotheses derived from psychological theories, together with insights from physiological assessments and brain imaging, highlight the importance of mechanistically driven approaches. Physical system changes, for example following injury, can result in alterations of psychological processes and are accompanied by changes in corticolimbic circuits, which have been shown to be essential in emotional learning and memory, as well as reward processing and related behavior. In the present review, we thus highlight the importance of motivational, reward/pain relief, and fear learning processes in the context of chronic pain and discuss the potential of a mechanistic understanding of chronic pain within a clinical perspective, for example for the development of therapeutic strategies. We argue that changes in these mechanisms are not only characteristic for chronic pain, reflecting consequences of the disorder, but are also critically involved in the transition from acute to chronic pain states. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  9. Discrete meso-element simulation of the failure behavior of short-fiber composites under dynamic loading

    International Nuclear Information System (INIS)

    Liu Wenyan; Tang, Z.P.; Liu Yunxin

    2000-01-01

    In recent years, more attention has been paid to a better understanding of the failure behavior and mechanism of heterogeneous materials at the meso-scale level. In this paper, the crack initiation and development in epoxy composites reinforced with short steel fibers under dynamic loading were simulated and analyzed with the 2D Discrete Meso-Element Dynamic Method. Results show that the damage process depends greatly on the binding property between matrix and fibers

  10. Short fatigue cracks growth and closure behavior in an austenitic stainless steel at 600 C and 650 C

    International Nuclear Information System (INIS)

    Polvora, J.P.; Laiarinandrasana, L.; Drubay, B.; Piques, R.; Martelet, B.

    1995-01-01

    In this work, following fatigue crack growth tests carried out at the CEN-SACLAY (AMORFIS program) by Laiarinandrasana (1994) on 316 L(N) CT specimens at 650 0 C and 600 0 C, short crack behavior of cracks emanating from machined notches is investigated. Experimental results are presented and discussions are directed to notch plasticity effect in relation with variations in crack opening stress intensity factor, K op , with crack lenght (author). 12 refs., 5 figs., 2 tab

  11. Definition of the electric requirements for the equipment associated to the limiter reactor on a 550 kV line occurring from manoeuvres under short circuits; Definicao dos requisitos eletricos dos equipamentos associados ao reator limitador em 550 kV, em decorrencia de manobras sob curtos-circuitos

    Energy Technology Data Exchange (ETDEWEB)

    Machado Junior, Camilo; Furuoka, Nita; Rose, Eber Havila [ELETRONORTE, Brasilia, DF (Brazil)]. E-mail: eber@eln.gov.br; Violin, Airton; Martinez, Manuel Luis Barreira [Escola Federal de Engenharia de Itajuba (EFEI), MG (Brazil). Inst. de Engenharia Eletrica. Lab. de Alta Tensao; Saraiva, Carlos Alberto Moura [Consorcio THEMAG-ENGEVIX, Sao Paulo, SP (Brazil)

    2001-07-01

    This paper presents the ascertaining based on the TRT study results performed to the definition of the new circuit breakers characteristics for the second stage of the Tucurui hydroelectric power plant, placed at the northern Brazil and with final configuration of two power houses and two air isolated substations, amounting 9 GVA. To reduce the short-circuit level to satisfactory values series reactors were used among the 550 kV substations. The result of the studies associated to the circuit breaker specifications are presented.

  12. Double functions of porous TiO2 electrodes on CH3NH3PbI3 perovskite solar cells: Enhancement of perovskite crystal transformation and prohibition of short circuiting

    Directory of Open Access Journals (Sweden)

    Govindhasamy Murugadoss

    2014-08-01

    Full Text Available In order to analyze the crystal transformation from hexagonal PbI2 to CH3NH3PbI3 by the sequential (two-step deposition process, perovskite CH3NH3PbI3 layers were deposited on flat and/or porous TiO2 layers. Although the narrower pores using small nanoparticles prohibited the effective transformation, the porous-TiO2 matrix was able to help the crystal transformation of PbI2 to CH3NH3PbI3 by sequential two-step deposition. The resulting PbI2 crystals in porous TiO2 electrodes did not deteriorate the photovoltaic effects. Moreover, it is confirmed that the porous TiO2 electrode had served the function of prohibiting short circuits between working and counter electrodes in perovskite solar cells.

  13. Digital circuit boards mach 1 GHz

    CERN Document Server

    Morrison, Ralph

    2012-01-01

    A unique, practical approach to the design of high-speed digital circuit boards The demand for ever-faster digital circuit designs is beginning to render the circuit theory used by engineers ineffective. Digital Circuit Boards presents an alternative to the circuit theory approach, emphasizing energy flow rather than just signal interconnection to explain logic circuit behavior. The book shows how treating design in terms of transmission lines will ensure that the logic will function, addressing both storage and movement of electrical energy on these lines. It cove

  14. Advantages of the synthetic technique for the conduction of short circuit tests to breakers; Ventajas de la tecnica sintetica para realizar pruebas de corto circuito a interruptores

    Energy Technology Data Exchange (ETDEWEB)

    Sibilski, Henry [Instituto Electrotecnico de Varsovia, Varsovia (Poland); Ochoa Vivanco, Ruben [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    In this article the operational principle of the synthetic test is described; specifically of the current injection circuit in parallel. Its utilization in the research and development of new breaker models and its wide possibilities regarding its testing characteristics is outlined. Likewise the different tests that can be performed by means of the synthetic technique are described. Finally the importance of the synthetic tests is outlined for the development of own technology in the area of interruption equipment and emphasis is made that in industrialized countries this technique is of common practice. [Espanol] En este articulo se describe el principio de operacion de la prueba sintetica; especificamente del circuito de inyeccion de corriente en paralelo. Se destaca su utilizacion en la investigacion y desarrollo de nuevos modelos de interruptores y sus amplias posibilidades en cuanto a caracteristicas de prueba. Asimismo, se describen las diferentes pruebas que pueden realizarse mediante la tecnica sintetica. Por ultimo, se destaca la importancia de las pruebas sinteticas para el desarrollo de tecnologia propia en el area de equipos de interrupcion, y se hace notar que en paises desarrollados, esta tecnica es practica comun.

  15. The effect of a short-term high-intensity circuit training program on work capacity, body composition, and blood profiles in sedentary obese men: a pilot study.

    Science.gov (United States)

    Miller, Matthew B; Pearcey, Gregory E P; Cahill, Farrell; McCarthy, Heather; Stratton, Shane B D; Noftall, Jennifer C; Buckle, Steven; Basset, Fabien A; Sun, Guang; Button, Duane C

    2014-01-01

    The objective of this study was to determine how a high-intensity circuit-training (HICT) program affects key physiological health markers in sedentary obese men. Eight obese (body fat percentage >26%) males completed a four-week HICT program, consisting of three 30-minute exercise sessions per week, for a total of 6 hours of exercise. Participants' heart rate (HR), blood pressure (BP), rating of perceived exertion, total work (TW), and time to completion were measured each exercise session, body composition was measured before and after HICT, and fasting blood samples were measured before throughout, and after HICT program. Blood sample measurements included total cholesterol, triacylglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, glucose, and insulin. Data were analyzed by paired t-tests and one-way ANOVA with repeated measures. Statistical significance was set to P < 0.05. Data analyses revealed significant (P < 0.05) improvements in resting HR (16% decrease), systolic BP (5.5% decrease), TW (50.7%), fat tissue percentage (3.6%), lean muscle tissue percentage (2%), cholesterol (13%), triacylglycerol (37%), and insulin (18%) levels from before to after HICT program. Overall, sedentary obese males experienced a significant improvement in biochemical, physical, and body composition characteristics from a HICT program that was only 6 hours of the total exercise.

  16. Advantages of the synthetic technique for the conduction of short circuit tests to breakers; Ventajas de la tecnica sintetica para realizar pruebas de corto circuito a interruptores

    Energy Technology Data Exchange (ETDEWEB)

    Sibilski, Henry [Instituto Electrotecnico de Varsovia, Varsovia (Poland); Ochoa Vivanco, Ruben [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    In this article the operational principle of the synthetic test is described; specifically of the current injection circuit in parallel. Its utilization in the research and development of new breaker models and its wide possibilities regarding its testing characteristics is outlined. Likewise the different tests that can be performed by means of the synthetic technique are described. Finally the importance of the synthetic tests is outlined for the development of own technology in the area of interruption equipment and emphasis is made that in industrialized countries this technique is of common practice. [Espanol] En este articulo se describe el principio de operacion de la prueba sintetica; especificamente del circuito de inyeccion de corriente en paralelo. Se destaca su utilizacion en la investigacion y desarrollo de nuevos modelos de interruptores y sus amplias posibilidades en cuanto a caracteristicas de prueba. Asimismo, se describen las diferentes pruebas que pueden realizarse mediante la tecnica sintetica. Por ultimo, se destaca la importancia de las pruebas sinteticas para el desarrollo de tecnologia propia en el area de equipos de interrupcion, y se hace notar que en paises desarrollados, esta tecnica es practica comun.

  17. Behavior control in the sensorimotor loop with short-term synaptic dynamics induced by self-regulating neurons

    Directory of Open Access Journals (Sweden)

    Hazem eToutounji

    2014-05-01

    Full Text Available The behavior and skills of living systems depend on the distributed control provided by specialized and highly recurrent neural networks. Learning and memory in these systems is mediated by a set of adaptation mechanisms, known collectively as neuronal plasticity. Translating principles of recurrent neural control and plasticity to artificial agents has seen major strides, but is usually hampered by the complex interactions between the agent's body and its environment. One of the important standing issues is for the agent to support multiple stable states of behavior, so that its behavioral repertoire matches the requirements imposed by these interactions. The agent also must have the capacity to switch between these states in time scales that are comparable to those by which sensory stimulation varies. Achieving this requires a mechanism of short-term memory that allows the neurocontroller to keep track of the recent history of its input, which finds its biological counterpart in short-term synaptic plasticity. This issue is approached here by deriving synaptic dynamics in recurrent neural networks. Neurons are introduced as self-regulating units with a rich repertoire of dynamics. They exhibit homeostatic properties for certain parameter domains, which result in a set of stable states and the required short-term memory. They can also operate as oscillators, which allow them to surpass the level of activity imposed by their homeostatic operation conditions. Neural systems endowed with the derived synaptic dynamics can be utilized for the neural behavior control of autonomous mobile agents. The resulting behavior depends also on the underlying network structure, which is either engineered, or developed by evolutionary techniques. The effectiveness of these self-regulating units is demonstrated by controlling locomotion of a hexapod with eighteen degrees of freedom, and obstacle-avoidance of a wheel-driven robot.

  18. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

    A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...

  19. Circuit Training.

    Science.gov (United States)

    Nelson, Jane B.

    1998-01-01

    Describes a research-based activity for high school physics students in which they build an LC circuit and find its resonant frequency of oscillation using an oscilloscope. Includes a diagram of the apparatus and an explanation of the procedures. (DDR)

  20. Short-term compassion training increases prosocial behavior in a newly developed prosocial game

    OpenAIRE

    Leiberg, S.; Klimecki, O.; Singer, T.

    2011-01-01

    Compassion has been suggested to be a strong motivator for prosocial behavior. While research has demonstrated that compassion training has positive effects on mood and health, we do not know whether it also leads to increases in prosocial behavior. We addressed this question in two experiments. In Experiment 1, we introduce a new prosocial game, the Zurich Prosocial Game (ZPG), which allows for repeated, ecologically valid assessment of prosocial behavior and is sensitive to the influence of...

  1. Circuits regulating pleasure and happiness:the evolution of reward-seeking and misery-fleeing behavioral mechanisms in vertebrates

    Directory of Open Access Journals (Sweden)

    Anton J.M. Loonen

    2015-10-01

    Full Text Available The very first free-moving animals in the oceans over 540 million years ago must have been able to obtain food, territory and shelter, as well as reproduce. Therefore, they would have needed regulatory mechanisms to induce movements enabling achievement of these prerequisites for survival. It can be useful to consider these mechanisms in primitive chordates, which represent our earliest ancestors, to develop hypotheses addressing how these essential parts of human behavior are regulated and relate to more sophisticated behavioral manifestations such as mood. An animal comparable to lampreys was the earliest known vertebrate with a modern forebrain consisting of old and new cortical parts. Lampreys have a separate dorsal pallium, the forerunner of the most recently developed part of the cerebral cortex. In addition, the lamprey extrapyramidal system, which regulates movement, is modern. However, in lampreys and their putative forerunners, the hagfishes, the striatum, which is the input part of this extrapyramidal system, probably corresponds to the human centromedial amygdala, which in higher vertebrates is part of a system mediating fear and anxiety. Both animals have well-developed nuclear habenulae, which are involved in several critical behaviors; in lampreys this system regulates the reward system that reinforces appetitive-seeking behavior or the avoidance system that reinforces flight behavior resulting from negative inputs. Lampreys also have a distinct glutamatergic nucleus, the so-called habenula-projection globus pallidus, which receives input from glutamatergic and GABAergic signals and gives output to the lateral habenula. Via this route, this nucleus influences midbrain monoaminergic nuclei and regulates the food acquisition system. These various structures involved in motor regulation in the lampreys may be conserved in humans and include two complementary mechanisms for reward reinforcement and avoidance behaviors. The first

  2. Circuits regulating pleasure and happiness: the evolution of reward-seeking and misery-fleeing behavioral mechanisms in vertebrates.

    Science.gov (United States)

    Loonen, Anton J M; Ivanova, Svetlana A

    2015-01-01

    The very first free-moving animals in the oceans over 540 million years ago must have been able to obtain food, territory, and shelter, as well as reproduce. Therefore, they would have needed regulatory mechanisms to induce movements enabling achievement of these prerequisites for survival. It can be useful to consider these mechanisms in primitive chordates, which represent our earliest ancestors, to develop hypotheses addressing how these essential parts of human behavior are regulated and relate to more sophisticated behavioral manifestations such as mood. An animal comparable to lampreys was the earliest known vertebrate with a modern forebrain consisting of old and new cortical parts. Lampreys have a separate dorsal pallium, the forerunner of the most recently developed part of the cerebral cortex. In addition, the lamprey extrapyramidal system (EPS), which regulates movement, is modern. However, in lampreys and their putative forerunners, the hagfishes, the striatum, which is the input part of this EPS, probably corresponds to the human centromedial amygdala, which in higher vertebrates is part of a system mediating fear and anxiety. Both animals have well-developed nuclear habenulae, which are involved in several critical behaviors; in lampreys this system regulates the reward system that reinforces appetitive-seeking behavior or the avoidance system that reinforces flight behavior resulting from negative inputs. Lampreys also have a distinct glutamatergic nucleus, the so-called habenula-projection globus pallidus, which receives input from glutamatergic and GABAergic signals and gives output to the lateral habenula. Via this route, this nucleus influences midbrain monoaminergic nuclei and regulates the food acquisition system. These various structures involved in motor regulation in the lampreys may be conserved in humans and include two complementary mechanisms for reward reinforcement and avoidance behaviors. The first system is associated with

  3. [Experiences in short-term dialyses with 2 capillary dialyzers in parallel and serial circuit in 2 and 3 shift operations].

    Science.gov (United States)

    Gerhardt, W; Krohs, G

    1976-02-01

    It is reported on experiences made in 200 short-term dialyses with every 2 capillary dialysators. 167 dialyses of which 112 were performed by means of parallel arrangement and 55 by means of serial arrangement of the dialysators are analysed in detail. In their effectivity of dialysis the two variants proved to be nearly equivalent, in which cases the series-connection is of practical advantage. In two shifts of nurses up to 3 shifts of patients could be treated. In the large area dialysis an adaptation of the dialysate and a more intensive control of the patients must be performed. Advantages and disadvantages of this method are discussed.

  4. A Preliminary Report of Short-Term Cognitive-Behavioral Group Therapy for Inpatients With Personality Disorders

    Science.gov (United States)

    SPRINGER, TAMAR; LOHR, NAOMI E.; BUCHTEL, HENRY A.; SILK, KENNETH R.

    1996-01-01

    A randomized, controlled study evaluated the effectiveness of a cognitive-behavioral therapy group, based on Linehan’s dialectical behavior therapy, for inpatients with personality disorders. The treatment, a problem-solving skills group focused on parasuicidality, was compared with a discussion control group. Change was assessed by self-report measures and behavioral observations on the unit. Subjects in both groups improved significantly on most change measures, although no significant between-group differences were found. However, the treatment group patients viewed the intervention as more beneficial to them in their lives outside the hospital. The usefulness of this type of group on a short-term unit is discussed. PMID:22700265

  5. Pendulating-A grounded theory explaining patients' behavior shortly after having a leg amputated due to vascular disease.

    Science.gov (United States)

    Madsen, Ulla Riis; Hommel, Ami; Bååth, Carina; Berthelsen, Connie Bøttcher

    2016-01-01

    Although the group of vascular leg amputated patients constitutes some of the most vulnerable and frail on the orthopedic wards, previous research of amputated patients has focused on patients attending gait training in rehabilitation facilities leaving the patient experience shortly after surgery unexplored. Understanding patients' behavior shortly after amputation could inform health professionals in regard to how these vulnerable patients' needs at hospital can be met as well as how to plan for care post-discharge. To construct a grounded theory (GT) explaining patients' behavior shortly after having a leg amputated as a result of vascular disease. In line with constructivist GT methodology, data from ethnographic observations and interviews were simultaneously collected and analyzed using the constant comparative method covering the patients' experiences during the first 4 weeks post-surgery. Data collection was guided by theoretical sampling and comprised 11 patients. A GT was constructed. Patients went through a three-phased process as they realized they were experiencing a life-changing event. The first phase was "Losing control" and comprised the sub-categories "Being overwhelmed" and "Facing dependency." The second phase was "Digesting the shock" and comprised the sub-categories "Swallowing the life-changing decision," "Detecting the amputated body" and "Struggling dualism." The third phase was "Regaining control" and comprised the sub-categories "Managing consequences" and "Building-up hope and self-motivation." "Pendulating" was identified as the core category describing the general pattern of behavior and illustrated how patients were swinging both cognitively and emotionally throughout the process. The theory of "Pendulating" offers a tool to understand the amputated patients' behavior and underlying concerns and to recognize where they are in the process. Concepts from the theory could be used by health professionals who support patients coping with

  6. A Novel Method for Measurements of the Penetration Depth of MgB2 Superconductor Films by Using Sapphire Resonators with Short-Circuited Parallel Plates

    International Nuclear Information System (INIS)

    Jung, Ho Sang; Lee, J. H.; Cho, Y. H.; Lee, Sang Young; Seong, W. K.; Lee, N. H.; Kang, W. N.

    2009-01-01

    We introduce a measurement method that enables to measure the penetration depth(λ) of superconductor films by using a short-ended parallel plate sapphire resonator. Variations in the (λof MgB 2 films could be measured down to the lowest temperature using a sapphire resonator with a YBa 2 Cu 3 O 7-x film at the bottom. A model equation of λλ 0 [1-(T/T c ) τ ] -1/2 for MgB 2 films appeared to describe the observed variations of the resonant frequency of the sapphire resonator with temperature, with λ 0 , τ and T c used as the fitting parameters.

  7. The role of selective attention in short-term memory and goal-directed behavior

    NARCIS (Netherlands)

    Vissers, M.E.

    2018-01-01

    Selective attention enables the prioritization of goal-relevant aspects of our sensory environment in order to guide our actions, or to store goal-relevant information in short-term memory. Yet, it remains largely unclear how attention prioritizes goal-relevant information. For example, selective

  8. Dynamic behavior of HTSC opening switch models controlled by short over-critical current pulses

    International Nuclear Information System (INIS)

    Agafonov, A.V.; Krastelev, E.G.; Voronin, V.S.

    1999-01-01

    We present results of experimental research of dynamical properties of thin films of YBa 2 Cu 3 O 7 HTSC-switch models under action of short overcritical current pulses to test this method of control of fast high-power opening switches for accelerator applications

  9. Behavior change techniques used in group-based behavioral support by the English stop-smoking services and preliminary assessment of association with short-term quit outcomes.

    Science.gov (United States)

    West, Robert; Evans, Adam; Michie, Susan

    2011-12-01

    To develop a reliable coding scheme for components of group-based behavioral support for smoking cessation, to establish the frequency of inclusion in English Stop-Smoking Service (SSS) treatment manuals of specific components, and to investigate the associations between inclusion of behavior change techniques (BCTs) and service success rates. A taxonomy of BCTs specific to group-based behavioral support was developed and reliability of use assessed. All English SSSs (n = 145) were contacted to request their group-support treatment manuals. BCTs included in the manuals were identified using this taxonomy. Associations between inclusion of specific BCTs and short-term (4-week) self-reported quit outcomes were assessed. Fourteen group-support BCTs were identified with >90% agreement between coders. One hundred and seven services responded to the request for group-support manuals of which 30 had suitable documents. On average, 7 BCTs were included in each manual. Two were positively associated with 4-week quit rates: "communicate group member identities" and a "betting game" (a financial deposit that is lost if a stop-smoking "buddy" relapses). It is possible to reliably code group-specific BCTs for smoking cessation. Fourteen such techniques are present in guideline documents of which 2 appear to be associated with higher short-term self-reported quit rates when included in treatment manuals of English SSSs.

  10. Examining the Causes and Consequences of Short-Term Behavioral Change during the Middle Stone Age at Sibudu, South Africa.

    Directory of Open Access Journals (Sweden)

    Nicholas J Conard

    Full Text Available Sibudu in KwaZulu-Natal (South Africa with its rich and high-resolution archaeological sequence provides an ideal case study to examine the causes and consequences of short-term variation in the behavior of modern humans during the Middle Stone Age (MSA. We present the results from a technological analysis of 11 stratified lithic assemblages which overlie the Howiesons Poort deposits and all date to ~58 ka. Based on technological and typological attributes, we conducted inter-assemblage comparisons to characterize the nature and tempo of cultural change in successive occupations. This work identified considerable short-term variation with clear temporal trends throughout the sequence, demonstrating that knappers at Sibudu varied their technology over short time spans. The lithic assemblages can be grouped into three cohesive units which differ from each other in the procurement of raw materials, the frequency in the methods of core reduction, the kind of blanks produced, and in the nature of tools the inhabitants of Sibudu made and used. These groups of assemblages represent different strategies of lithic technology, which build upon each other in a gradual, cumulative manner. We also identify a clear pattern of development toward what we have previously defined as the Sibudan cultural taxonomic unit. Contextualizing these results on larger geographical scales shows that the later phase of the MSA during MIS 3 in KwaZulu-Natal and southern Africa is one of dynamic cultural change rather than of stasis or stagnation as has at times been claimed. In combination with environmental, subsistence and contextual information, our high-resolution data on lithic technology suggest that short-term behavioral variability at Sibudu can be best explained by changes in technological organization and socio-economic dynamics instead of environmental forcing.

  11. Examining the Causes and Consequences of Short-Term Behavioral Change during the Middle Stone Age at Sibudu, South Africa.

    Science.gov (United States)

    Conard, Nicholas J; Will, Manuel

    2015-01-01

    Sibudu in KwaZulu-Natal (South Africa) with its rich and high-resolution archaeological sequence provides an ideal case study to examine the causes and consequences of short-term variation in the behavior of modern humans during the Middle Stone Age (MSA). We present the results from a technological analysis of 11 stratified lithic assemblages which overlie the Howiesons Poort deposits and all date to ~58 ka. Based on technological and typological attributes, we conducted inter-assemblage comparisons to characterize the nature and tempo of cultural change in successive occupations. This work identified considerable short-term variation with clear temporal trends throughout the sequence, demonstrating that knappers at Sibudu varied their technology over short time spans. The lithic assemblages can be grouped into three cohesive units which differ from each other in the procurement of raw materials, the frequency in the methods of core reduction, the kind of blanks produced, and in the nature of tools the inhabitants of Sibudu made and used. These groups of assemblages represent different strategies of lithic technology, which build upon each other in a gradual, cumulative manner. We also identify a clear pattern of development toward what we have previously defined as the Sibudan cultural taxonomic unit. Contextualizing these results on larger geographical scales shows that the later phase of the MSA during MIS 3 in KwaZulu-Natal and southern Africa is one of dynamic cultural change rather than of stasis or stagnation as has at times been claimed. In combination with environmental, subsistence and contextual information, our high-resolution data on lithic technology suggest that short-term behavioral variability at Sibudu can be best explained by changes in technological organization and socio-economic dynamics instead of environmental forcing.

  12. Decreases in tanning behaviors following a short online survey: Potential for prevention?

    Science.gov (United States)

    Rodgers, Rachel F; Franko, Debra L; Gottlieb, Mark; Daynard, Richard

    2015-01-01

    To date, tanning prevention programs have led to limited success. The aim of the present study was to investigate potential unexpected prevention effects of completing an online survey focused on tanning attitudes, behaviors, and knowledge among female college tanners. A sample of 92 female undergraduate students from the USA, mean age = 20.09, SD = 1.41 years, who engaged in indoor tanning completed an online survey assessing awareness of tanning-related health risks, appearance-based motivations to tan and not to tan, media literacy related to tanning marketing, and tanning behaviors in 2013. Four months later, participants were invited to complete a follow-up survey assessing tanning intentions and behaviors since completing the initial survey. Fifty-one participants (55%) completed the follow-up questions, of whom 43 (84.3%) reported having decreased or ceased engaging in indoor tanning. In addition participants provided comments indicating that completing the survey had lead to decreases in their tanning behaviors. Our study presents novel and compelling support for using brief online surveys for decreasing health-risk behaviors such as sunbed use. Such measures are extremely cost-effective and easy to disseminate and implement. Replication and extension of these findings are warranted.

  13. The role of selective attention in short-term memory and goal-directed behavior

    OpenAIRE

    Vissers, M.E.

    2018-01-01

    Selective attention enables the prioritization of goal-relevant aspects of our sensory environment in order to guide our actions, or to store goal-relevant information in short-term memory. Yet, it remains largely unclear how attention prioritizes goal-relevant information. For example, selective attention may enhance processing of goal-relevant information, suppress processing of distracting information, or both. The research presented in this dissertation examined the neurophysiological mec...

  14. Cognitive Behavioral Therapy versus Short Psychodynamic Supportive Psychotherapy in the outpatient treatment of depression: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Kool Simone

    2007-10-01

    Full Text Available Abstract Background Previous research has shown that Short Psychodynamic Supportive Psychotherapy (SPSP is an effective alternative to pharmacotherapy and combined treatment (SPSP and pharmacotherapy in the treatment of depressed outpatients. The question remains, however, how Short Psychodynamic Supportive Psychotherapy compares with other established psychotherapy methods. The present study compares Short Psychodynamic Supportive Psychotherapy to the evidence-based Cognitive Behavioral Therapy in terms of acceptability, feasibility, and efficacy in the outpatient treatment of depression. Moreover, this study aims to identify clinical predictors that can distinguish patients who may benefit from either of these treatments in particular. This article outlines the study protocol. The results of the study, which is being currently carried out, will be presented as soon as they are available. Methods/Design Adult outpatients with a main diagnosis of major depressive disorder or depressive disorder not otherwise specified according to DSM-IV criteria and mild to severe depressive symptoms (Hamilton Depression Rating Scale score ≥ 14 are randomly allocated to Short Psychodynamic Supportive Psychotherapy or Cognitive Behavioral Therapy. Both treatments are individual psychotherapies consisting of 16 sessions within 22 weeks. Assessments take place at baseline (week 0, during the treatment period (week 5 and 10 and at treatment termination (week 22. In addition, a follow-up assessment takes place one year after treatment start (week 52. Primary outcome measures are the number of patients refusing treatment (acceptability; the number of patients terminating treatment prematurely (feasibility; and the severity of depressive symptoms (efficacy according to an independent rater, the clinician and the patient. Secondary outcome measures include general psychopathology, general psychotherapy outcome, pain, health-related quality of life, and cost

  15. Short fatigue cracks growth and closure behavior in an austenitic stainless steel at 600 C and 650 C

    Energy Technology Data Exchange (ETDEWEB)

    Polvora, J.P.; Laiarinandrasana, L.; Drubay, B.; Piques, R.; Martelet, B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1995-12-31

    In this work, following fatigue crack growth tests carried out at the CEN-SACLAY (AMORFIS program) by Laiarinandrasana (1994) on 316 L(N) CT specimens at 650{sup 0}C and 600{sup 0}C, short crack behavior of cracks emanating from machined notches is investigated. Experimental results are presented and discussions are directed to notch plasticity effect in relation with variations in crack opening stress intensity factor, K{sub op}, with crack lenght (author). 12 refs., 5 figs., 2 tab.

  16. Effects of short-term training on behavioral learning and skill acquisition during intraoral fine motor task

    DEFF Research Database (Denmark)

    Kumar, Abhishek; Grigoriadis, Joannis; Trulsson, Mats

    2015-01-01

    Sensory information from the orofacial mechanoreceptors are used by the nervous system to optimize the positioning of food, determine the force levels, and force vectors involved in biting of food morsels. Moreover, practice resulting from repetition could be a key to learning and acquiring a motor...... movements. Thirty healthy volunteers were asked to intraorally manipulate and split a chocolate candy, into two equal halves. The participants performed three series (with ten 10 trials) of the task before and after a short-term (approximately 30min) training. The accuracy of the split and vertical jaw...... task induces behavior learning, skill acquisition and optimization of jaw movements in terms of better performance and reduction in the duration of jaw movements, during the task. The finding of the present study provides insights on into how humans learn oral motor behaviors or the kind of adaptation...

  17. Difference in oxygen impurity behavior between repetitive short discharges and one long discharge on TRIAM-1M

    International Nuclear Information System (INIS)

    Ogawa, M.; Sakamoto, M.; Sato, K.N.; Zushi, H.; Nakamura, K.; Hanada, K.; Idei, H.; Hasegawa, M.; Kawasaki, S.; Nakashima, H.; Higashijima, A.

    2007-01-01

    Oxygen impurity behaviors of one long duration discharge and repetition of short duration discharges have been investigated in TRIAM-1M. In the former case, the OII line intensity divided by the line averaged electron density, which is considered as a monitor of oxygen concentration on the plasma facing surface (PFS), decreased with the time constant, τ d , of 30-50 s during the discharge due to the hydrogen flux to PFS. In the latter case, τ d is in the range of 70-600 s. There exists a big difference of global behavior of oxygen impurity between both cases. The difference seems to result from the absence or presence of the interval time between the discharges. The oxygen concentration on PFS increases during the interval time due to adsorption of H 2 O. The time constant of the increase in the oxygen concentration is evaluated to be about 5500 s from Langmuir adsorption isotherms analysis

  18. Short-Term Load Forecasting Based on the Analysis of User Electricity Behavior

    Directory of Open Access Journals (Sweden)

    Yuancheng Li

    2016-11-01

    Full Text Available The smart meter is an important part of the smart grid, and in order to take full advantage of smart meter data, this paper mines the electricity behaviors of smart meter users to improve the accuracy of load forecasting. First, the typical day loads of users are calculated separately according to different date types (ordinary workdays, day before holidays, holidays. Second, the similarity between user electricity behaviors is mined and the user electricity loads are clustered to classify the users with similar behaviors into the same cluster. Finally, the load forecasting model based on the Online Sequential Extreme Learning Machine (OS-ELM is applied to different clusters to conduct load forecasting and the load forecast is summed to obtain the system load. In order to prove the validity of the proposed method, we performed simulation experiments on the MATLAB platform using smart meter data from the Ireland electric power cooperation. The experimental results show that the proposed method is able to mine the user electricity behaviors deeply, improve the accuracy of load forecasting by the reasonable clustering of users, and reveal the relationship between forecasting accuracy and cluster numbers.

  19. Financial Literacy and Long- and Short-Term Financial Behavior in Different Age Groups

    Science.gov (United States)

    Henager, Robin; Cude, Brenda J.

    2016-01-01

    The purpose of this study was to examine the relationship between financial literacy and financial behaviors among various age groups. Financial literacy was measured in three ways: objective financial knowledge, subjective financial knowledge or confidence, and subjective financial management ability. The age groups were 18-24, 25-34, 35-44,…

  20. Decreases in tanning behaviors following a short online survey: Potential for prevention?

    Directory of Open Access Journals (Sweden)

    Rachel F. Rodgers

    2015-01-01

    Conclusions: Our study presents novel and compelling support for using brief online surveys for decreasing health-risk behaviors such as sunbed use. Such measures are extremely cost-effective and easy to disseminate and implement. Replication and extension of these findings are warranted.