WorldWideScience

Sample records for atmospheric electric circuit

  1. The global atmospheric electrical circuit and climate

    CERN Document Server

    Harrison, R G

    2004-01-01

    Evidence is emerging for physical links among clouds, global temperatures, the global atmospheric electrical circuit and cosmic ray ionisation. The global circuit extends throughout the atmosphere from the planetary surface to the lower layers of the ionosphere. Cosmic rays are the principal source of atmospheric ions away from the continental boundary layer: the ions formed permit a vertical conduction current to flow in the fair weather part of the global circuit. Through the (inverse) solar modulation of cosmic rays, the resulting columnar ionisation changes may allow the global circuit to convey a solar influence to meteorological phenomena of the lower atmosphere. Electrical effects on non-thunderstorm clouds have been proposed to occur via the ion-assisted formation of ultrafine aerosol, which can grow to sizes able to act as cloud condensation nuclei, or through the increased ice nucleation capability of charged aerosols. Even small atmospheric electrical modulations on the aerosol size distribution ca...

  2. Atmospheric Electric Field measurements at Eastern North Atlantic ARM Climate Research Facility: Global Electric Circuit Evolution

    Science.gov (United States)

    Lopes, Francisco; Silva, Hugo; Nitschke, Kim; Azevedo, Eduardo

    2016-04-01

    The Eastern North Atlantic (ENA) facility of the ARM programme (established an supported by the U.S. Department of Energy with the collaboration of the local government and University of the Azores), is located at Graciosa Island of the Azores Archipelago (39° N; 28° W). It constitutes a strategic observatory for Atmospheric Electricity since it is located in the Atlantic Ocean basin exposed to clean marine aerosol conditions which reduces the well known spectral signature of atmospheric pollution and enables the study of the so called Global Electrical Circuit (GEC). First evidences of the existence of a GEC affecting the Earth's Electric Environment has retrieved by the Carnegie cruise expedition, in what became known as the Carnegie Curve. Those measurements were made in the Ocean in several campaigns and the present studies aims at reconsidering measurements in similar conditions but in a long-term basis, at least 5 years. This will contribute to the understanding of the long-term evolution of the Ionospheric Potential (IP). In literature there is theoretical evidence that it is decreasing IP in strength, but that conjecture is still lacking valid experimental evidence. Moreover, to clearly identify the GEC signal two effects must be taken into account: the effect of surface radon gas variation, because the Azores Archipelago is a seismic active region the possible influence of Earthquakes cannot be discarded easily; the effect of short-term solar activity on the Atmospheric Electricity modulation, solar flares emitting solar particles (e.g., solar energetic protons) need to be considered in this study.

  3. The global atmospheric electric circuit and its effects on cloud microphysics

    International Nuclear Information System (INIS)

    This review is an overview of progress in understanding the theory and observation of the global atmospheric electric circuit, with the focus on its dc aspects, and its short and long term variability. The effects of the downward ionosphere-earth current density, Jz, on cloud microphysics, with its variability as an explanation for small observed changes in weather and climate, will also be reviewed. The global circuit shows responses to external as well as internal forcing. External forcing arises from changes in the distribution of conductivity due to changes in the cosmic ray flux and other energetic space particle fluxes, and at high magnetic latitudes from solar wind electric fields. Internal forcing arises from changes in the generators and changes in volcanic and anthropogenic aerosols in the troposphere and stratosphere. All these result in spatial and temporal variation in Jz. Variations in Jz affect the production of space charge in layer clouds, with the charges being transferred to droplets and aerosol particles. New observations and new analyses are consistent with non-negligible effects of the charges on the microphysics of such clouds. Observed effects are small, but of high statistical significance for cloud cover and precipitation changes, with resulting atmospheric temperature, pressure and dynamics changes. These effects are detectable on the day-to-day timescale for repeated Jz changes of order 10%, and are thus second order electrical effects. The implicit first order effects have not, as yet, been incorporated into basic cloud and aerosol physics. Long term (multidecadal through millennial) global circuit changes, due to solar activity modulating the galactic cosmic ray flux, are an order of magnitude greater at high latitudes and in the stratosphere, as can be inferred from geological cosmogenic isotope records. Proxies for climate change in the same stratified depositories show strong correlations of climate with the inferred global circuit

  4. The global atmospheric electric circuit and its effects on cloud microphysics

    Science.gov (United States)

    Tinsley, B. A.

    2008-06-01

    This review is an overview of progress in understanding the theory and observation of the global atmospheric electric circuit, with the focus on its dc aspects, and its short and long term variability. The effects of the downward ionosphere-earth current density, Jz, on cloud microphysics, with its variability as an explanation for small observed changes in weather and climate, will also be reviewed. The global circuit shows responses to external as well as internal forcing. External forcing arises from changes in the distribution of conductivity due to changes in the cosmic ray flux and other energetic space particle fluxes, and at high magnetic latitudes from solar wind electric fields. Internal forcing arises from changes in the generators and changes in volcanic and anthropogenic aerosols in the troposphere and stratosphere. All these result in spatial and temporal variation in Jz. Variations in Jz affect the production of space charge in layer clouds, with the charges being transferred to droplets and aerosol particles. New observations and new analyses are consistent with non-negligible effects of the charges on the microphysics of such clouds. Observed effects are small, but of high statistical significance for cloud cover and precipitation changes, with resulting atmospheric temperature, pressure and dynamics changes. These effects are detectable on the day-to-day timescale for repeated Jz changes of order 10%, and are thus second order electrical effects. The implicit first order effects have not, as yet, been incorporated into basic cloud and aerosol physics. Long term (multidecadal through millennial) global circuit changes, due to solar activity modulating the galactic cosmic ray flux, are an order of magnitude greater at high latitudes and in the stratosphere, as can be inferred from geological cosmogenic isotope records. Proxies for climate change in the same stratified depositories show strong correlations of climate with the inferred global circuit

  5. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan

    1957-01-01

    Atmospheric Electricity brings together numerous studies on various aspects of atmospheric electricity. This book is composed of 13 chapters that cover the main problems in the field, including the maintenance of the negative charge on the earth and the origin of the charges in thunderstorms. After a brief overview of the historical developments of atmospheric electricity, this book goes on dealing with the general principles, results, methods, and the MKS system of the field. The succeeding chapters are devoted to some aspects of electricity in the atmosphere, such as the occurrence and d

  6. Electric circuits essentials

    CERN Document Server

    REA, Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electric Circuits I includes units, notation, resistive circuits, experimental laws, transient circuits, network theorems, techniques of circuit analysis, sinusoidal analysis, polyph

  7. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  8. Fair weather atmospheric electricity

    International Nuclear Information System (INIS)

    Not long after Franklin's iconic studies, an atmospheric electric field was discovered in 'fair weather' regions, well away from thunderstorms. The origin of the fair weather field was sought by Lord Kelvin, through development of electrostatic instrumentation and early data logging techniques, but was ultimately explained through the global circuit model of C.T.R. Wilson. In Wilson's model, charge exchanged by disturbed weather electrifies the ionosphere, and returns via a small vertical current density in fair weather regions. New insights into the relevance of fair weather atmospheric electricity to terrestrial and planetary atmospheres are now emerging. For example, there is a possible role of the global circuit current density in atmospheric processes, such as cloud formation. Beyond natural atmospheric processes, a novel practical application is the use of early atmospheric electrostatic investigations to provide quantitative information on past urban air pollution.

  9. Influence of the external electrical circuit on the regimes of a nanosecond repetitively pulsed discharge in air at atmospheric pressure

    International Nuclear Information System (INIS)

    This paper presents 2D simulations of nanosecond repetitively pulsed discharges in air at atmospheric pressure coupled with a model of the external electrical circuit used in experiments. Then, during the pulsed discharge, the voltage applied to the electrodes varies in time as a function of the time dependent value of the plasma channel conductivity. In this work, we have simulated several consecutive nanosecond pulsed discharges between two point electrodes in air initially at 1000 K at a frequency of 10 kHz. First, we have simulated three consecutive nanosecond spark discharges. We have shown that the air temperature increases significantly pulse after pulse in the discharge channel. As a consequence, for the three consecutive simulated nanosecond spark discharges, we have put forward a decrease in the discharge radius, pulse after pulse. Then, to further limit the discharge current, a ballast resistance R has been added into the electrical circuit and the results are presented for seven consecutive nanosecond discharges. For a value of R = 1000 Ω in the conditions studied in this work, we have shown that the first nanosecond discharges are in the glow regime, with a small gas heating per pulse. However, as the number of pulses increases due to the gas heating by each pulse, the discharge may transit to a multipulse nanosecond spark regime. For a higher value of R = 10 000 Ω, we have put forward that the gas heating by each nanosecond discharge becomes negligible and then the multipulse nanosecond discharge remains in this case in a stable ‘quasi-periodic’ multipulse glow regime. (paper)

  10. Electric circuits problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of electric circuits currently av

  11. Electric circuit theory applied electricity and electronics

    CERN Document Server

    Yorke, R

    1981-01-01

    Electric Circuit Theory provides a concise coverage of the framework of electrical engineering. Comprised of six chapters, this book emphasizes the physical process of electrical engineering rather than abstract mathematics. Chapter 1 deals with files, circuits, and parameters, while Chapter 2 covers the natural and forced response of simple circuit. Chapter 3 talks about the sinusoidal steady state, and Chapter 4 discusses the circuit analysis. The fifth chapter tackles frequency response of networks, and the last chapter covers polyphase systems. This book will be of great help to electrical

  12. Fair weather terrestrial atmospheric electricity

    Science.gov (United States)

    Harrison, G.

    Atmospheric electricity is one of the oldest experimental topics in atmospheric science. The fair weather aspects, although having less dramatic effects than thunderstorm electrification, link the microscale behaviour of ion clusters to currents flowing on the global scale. This talk will include a survey of some past measurements and measurement methods, as atmospheric electrical data from a variety of sites and eras are now being used to understand changes in atmospheric composition. Potential Gradient data was the original source of information on the global atmospheric electrical circuit, and similar measurements can now be used to reconstruct past air pollution concentrations, and black carbon loading.

  13. Variational integrators for electric circuits

    International Nuclear Information System (INIS)

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator

  14. New model simulations of the global atmospheric electric circuit driven by thunderstorms and electrified shower clouds: The roles of lightning and sprites

    DEFF Research Database (Denmark)

    Rycroft, Michael J.; Odzimek, Anna; Arnold, Neil F.;

    2007-01-01

    Several processes acting below, in and above thunderstorms and in electrified shower clouds drive upward currents which close through the global atmospheric electric circuit, These are all simulated in a novel way using the software package PSpice. A moderate negative cloud-to-ground lightning...... cloud-to-ground lightning discharge from the bottom of a thunderstorm decreases the ionospheric potential by 0.014%. Such a discharge may trigger a sprite, causing the ionospheric potential to decrease by similar to 1 V. The time scales for the recovery of the ionospheric potential are shown to be...... similar to 250 s, which is of the same order as the CR time constant for the global circuit. Knowing the global average rate of lightning discharges, it is found that negative cloud-to-ground discharges increase the ionospheric potential by only similar to 4%, and that positive cloud-to-ground discharges...

  15. Effects of lightning and sprites on the ionospheric potential, and threshold effects on sprite initiation, obtained using an analog model of the global atmospheric electric circuit

    Science.gov (United States)

    Rycroft, M. J.; Odzimek, A.

    2010-06-01

    A quantitative model of the global atmospheric electric circuit has been constructed using the PSpice electrical engineering software package. Currents (˜1 kA) above thunderstorms and electrified rain/shower clouds raise the potential of the ionosphere (presumed to be an equipotential surface at 80 km altitude) to ˜250 kV with respect to the Earth's surface. The circuit is completed by currents flowing down through the fair-weather atmosphere in the land/sea surface and up to the cloud systems. Using a model for the atmospheric conductivity profile, the effects of both negative and positive cloud-to-ground (CG) lightning discharges on the ionospheric potential have been estimated. A large positive CG discharge creates an electric field that exceeds the breakdown field from the ionosphere down to ˜74 km, thereby forming a halo, a column sprite, and some milliseconds later, from ˜67 km down to ˜55 km at ˜60 ms after the discharge, a “carrot” sprite. Estimates are made of the return stroke current and the thundercloud charge moment change of a +CG discharge required to exceed the threshold breakdown field, or the threshold field for creating and sustaining negative or positive streamers. The values for breakdown at 80 km altitude are 35 kA and 350 C.km, (Coulomb.kilometers), respectively, and those at 70 km altitude are 45 kA and 360 C.km, respectively. The different temporal and spatial developments of the mesospheric electric field distinguishing between column and carrot sprites agree with the latest deductions from recent observations. The current flowing in the highly conducting sprite reduces the ionospheric potential by ˜1 V.

  16. Planetary Atmospheric Electricity

    CERN Document Server

    Leblanc, F; Yair, Y; Harrison, R. G; Lebreton, J. P; Blanc, M

    2008-01-01

    This volume presents our contemporary understanding of atmospheric electricity at Earth and in other solar system atmospheres. It is written by experts in terrestrial atmospheric electricity and planetary scientists. Many of the key issues related to planetary atmospheric electricity are discussed. The physics presented in this book includes ionisation processes in planetary atmospheres, charge generation and separation, and a discussion of electromagnetic signatures of atmospheric discharges. The measurement of thunderstorms and lightning, including its effects and hazards, is highlighted by articles on ground and space based instrumentation, and new missions.Theory and modelling of planetary atmospheric electricity complete this review of the research that is undertaken in this exciting field of space science. This book is an essential research tool for space scientists and geoscientists interested in electrical effects in atmospheres and planetary systems. Graduate students and researchers who are new to t...

  17. Electrical circuit theory and technology

    CERN Document Server

    Bird, John

    2014-01-01

    This much-loved textbook explains the principles of electrical circuit theory and technology so that students of electrical and mechanical engineering can master the subject. Real-world situations and engineering examples put the theory into context. The inclusion of worked problems with solutions help you to learn and further problems then allow you to test and confirm you have fully understood each subject. In total the book contains 800 worked problems, 1000 further problems and 14 revision tests with answers online. This an ideal text for foundation and undergraduate degree students and those on upper level vocational engineering courses, in particular electrical and mechanical. It provides a sound understanding of the knowledge required by technicians in fields such as electrical engineering, electronics and telecommunications. This edition has been updated with developments in key areas such as semiconductors, transistors, and fuel cells, along with brand new material on ABCD parameters and Fourier's An...

  18. Trip electrical circuit of the gyrotion

    International Nuclear Information System (INIS)

    The electron cyclotron resonance heating system of INPE/LAP is shown and the trip electrical circuit of the gyrotron is described, together with its fundamental aspects. The trip electrical circuit consists basically of a series regulator circuit which regulates the output voltage level and controls the pulse width time. Besides that, a protection circuit for both tubes, regulator and gyrotron, against faults in the system. (author)

  19. Quantum Electric Circuits Analogous to Ballistic Conductors

    OpenAIRE

    Dragoman, Daniela

    2007-01-01

    The conductance steps in a constricted two-dimensional electron gas and the minimum conductivity in graphene are related to a new uncertainty relation between electric charge and conductance in a quantized electric circuit that mimics the electric transport in mesoscopic systems. This uncertainty relation makes specific use of the discreteness of electric charge. Quantum electric circuits analogous to both constricted two-dimensional electron gas and graphene are introduced. In the latter cas...

  20. Relaxation Based Electrical Simulation for VLSI Circuits

    Directory of Open Access Journals (Sweden)

    S. Rajkumar

    2012-06-01

    Full Text Available Electrical circuit simulation was one of the first CAD tools developed for IC design. The conventional circuit simulators like SPICE and ASTAP were designed initially for the cost effective analysis of circuits containing a few hundred transistors or less. A number of approaches have been used to improve the performances of congenital circuit simulators for the analysis of large circuits. Thereafter relaxation methods was proposed to provide more accurate waveforms than standard circuit simulators with up to two orders of magnitude speed improvement for large circuits. In this paper we have tried to highlights recently used waveform and point relaxation techniques for simulation of VLSI circuits. We also propose a simple parallelization technique and experimentally demonstrate that we can solve digital circuits with tens of million transistors in a few hours.

  1. Realizing a supercapacitor in an electrical circuit

    Energy Technology Data Exchange (ETDEWEB)

    Fukuhara, Mikio, E-mail: fukuhara@niche.tohoku.ac.jp; Kuroda, Tomoyuki; Hasegawa, Fumihiko [New Industry Creation Hatchery Center, Tohoku University, Sendai 980-8579 (Japan)

    2014-11-17

    Capacitors are commonly used in electronic resonance circuits; however, capacitors have not been used for storing large amounts of electrical energy in electrical circuits. Here, we report a superior RC circuit which serves as an electrical storage system characterized by quick charging and long-term discharging of electricity. The improved energy storage characteristics in this mixed electric circuit (R{sub 1} + R{sub 2}C{sub 1}) with small resistor R{sub 1}, large resistor R{sub 2}, and large capacitor C{sub 1} are derived from the damming effect by large R{sub 2} in simple parallel R{sub 2}C{sub 1} circuit. However, no research work has been carried out previously on the use of capacitors as electrical energy storage devices in circuits. Combined with nanotechnology, we hope that our finding will play a remarkable role in a variety of applications such as hybrid electric vehicles and backup power supplies.

  2. On equivalent resistance of electrical circuits

    CERN Document Server

    Kagan, Mikhail

    2015-01-01

    While the standard (introductory physics) way of computing the equvalent resistance of non-trivial electrical ciruits is based on Kirchhoff's rules, there is a mathematically and conceptually simpler approach, called the method of nodal potentials, whose basic variables are the values of electric potential at the circuit's nodes. In this paper, we review the method of nodal potentials and illustrate it using the Wheatstone bridge as an example. At the end, we derive - in a closed form - the equivalent resistance of a generic circuit, which we apply to a few sample circuits. The final result unveils a curious interplay between electrical circuits, matrix algebra, and graph theory and its applications to computer science. The paper is written at a level accessible by undergraduate students who are familiar with matrix arithmetic. For the more inquisitive reader, additional proofs and technical details are provided in the appendix.

  3. Chemical Detection using Electrically Open Circuits having no Electrical Connections

    Science.gov (United States)

    Woodward, Stanley E.; Olgesby, Donald M.; Taylor, Bryant D.; Shams, Qamar A.

    2008-01-01

    This paper presents investigations to date on chemical detection using a recently developed method for designing, powering and interrogating sensors as electrically open circuits having no electrical connections. In lieu of having each sensor from a closed circuit with multiple electrically connected components, an electrically conductive geometric pattern that is powered using oscillating magnetic fields and capable of storing an electric field and a magnetic field without the need of a closed circuit or electrical connections is used. When electrically active, the patterns respond with their own magnetic field whose frequency, amplitude and bandwidth can be correlated with the magnitude of the physical quantities being measured. Preliminary experimental results of using two different detection approaches will be presented. In one method, a thin film of a reactant is deposited on the surface of the open-circuit sensor. Exposure to a specific targeted reactant shifts the resonant frequency of the sensor. In the second method, a coating of conductive material is placed on a thin non-conductive plastic sheet that is placed over the surface of the sensor. There is no physical contact between the sensor and the electrically conductive material. When the conductive material is exposed to a targeted reactant, a chemical reaction occurs that renders the material non-conductive. The change in the material s electrical resistance within the magnetic field of the sensor alters the sensor s response bandwidth and amplitude, allowing detection of the reaction without having the reactants in physical contact with the sensor.

  4. Electric Current Circuits in Astrophysics

    CERN Document Server

    Kuijpers, Jan; Fletcher, Lyndsay

    2014-01-01

    Cosmic magnetic structures have in common that they are anchored in a dynamo, that an external driver converts kinetic energy into internal magnetic energy, that this magnetic energy is transported as Poynting flux across the magnetically dominated structure, and that the magnetic energy is released in the form of particle acceleration, heating, bulk motion, MHD waves, and radiation. The investigation of the electric current system is particularly illuminating as to the course of events and the physics involved. We demonstrate this for the radio pulsar wind, the solar flare, and terrestrial magnetic storms.

  5. Demonstrating Boolean Logic Using Simple Electrical Circuits

    Science.gov (United States)

    McElhaney, Kevin W.

    2004-01-01

    While exploring the subject of geometric proofs, boolean logic operators AND and OR can be used to allow students to visualize their true-or-false patterns. An activity in the form of constructing electrical circuits is illustrated to explain the concept.

  6. Compact atmospheric pressure plasma self-resonant drive circuits

    Science.gov (United States)

    Law, V. J.; Anghel, S. D.

    2012-02-01

    This paper reports on compact solid-state self-resonant drive circuits that are specifically designed to drive an atmospheric pressure plasma jet and a parallel-plate dielectric barrier discharge of small volume (0.5 cm3). The atmospheric pressure plasma (APP) device can be operated with helium, argon or a mixture of both. Equivalent electrical models of the self-resonant drive circuits and discharge are developed and used to estimate the plasma impedance, plasma power density, current density or electron number density of three APP devices. These parameters and the kinetic gas temperature are dependent on the self-resonant frequency of the APP device. For a fixed switching frequency and APP device geometry, the plasma parameters are controlled by adjusting the dc voltage at the primary coil and the gas flow rate. The resonant frequency is controlled by the selection of the switching power transistor and means of step-up voltage transformation (ferrite core, flyback transformer, or Tesla coil). The flyback transformer operates in the tens of kHz, the ferrite core in the hundreds of kHz and Tesla coil in the MHz range. Embedded within this work is the principle of frequency pulling which is exemplified in the flyback transformer circuit that utilizes a pickup coil for feedback control of the switching frequency.

  7. Compact atmospheric pressure plasma self-resonant drive circuits

    International Nuclear Information System (INIS)

    This paper reports on compact solid-state self-resonant drive circuits that are specifically designed to drive an atmospheric pressure plasma jet and a parallel-plate dielectric barrier discharge of small volume (0.5 cm3). The atmospheric pressure plasma (APP) device can be operated with helium, argon or a mixture of both. Equivalent electrical models of the self-resonant drive circuits and discharge are developed and used to estimate the plasma impedance, plasma power density, current density or electron number density of three APP devices. These parameters and the kinetic gas temperature are dependent on the self-resonant frequency of the APP device. For a fixed switching frequency and APP device geometry, the plasma parameters are controlled by adjusting the dc voltage at the primary coil and the gas flow rate. The resonant frequency is controlled by the selection of the switching power transistor and means of step-up voltage transformation (ferrite core, flyback transformer, or Tesla coil). The flyback transformer operates in the tens of kHz, the ferrite core in the hundreds of kHz and Tesla coil in the MHz range. Embedded within this work is the principle of frequency pulling which is exemplified in the flyback transformer circuit that utilizes a pickup coil for feedback control of the switching frequency. (paper)

  8. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    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. 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....

  9. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    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. 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...

  10. Effect of increased ionization on the atmospheric electric field

    International Nuclear Information System (INIS)

    This study is a review of atmospheric electrical theory with the purpose of predicting the atmospheric electrical effects of increased ionization caused by radioactive inert gases. A time-independent perturbation model for the global atmospheric electric circuit precdicts that the electric field at the sea surface would be reduced to about 76% of its unperturbed value by a surface 85Kr concentration of 3 nCi/m3. The electric field at a typical land station is predicted to be about 84% of its unperturbed value. Some scientists have suggested that the atmospheric electric field is part of a closed electrical feedback loop. The present model does not include such a closed feedback loop and may underestimate the total effects. This model is also useful for interpreting atmospheric electrical responses to natural fluctuations in the cosmic-ray component of background radiation

  11. Market price simulator based on analog electrical circuit

    OpenAIRE

    Aki-Hiro Sato; Hideki Takayasu

    2001-01-01

    We constructed an analog electrical circuit which generates fluctuations in which probability density function has power law tails. In the circuit fluctuations with an arbitrary exponent of the power law can be obtained by adjusting the resistance. With this low cost circuit the random fluctuations which have the similar statistics to foreign exchang rates can be generated as fast as an expensive digital computer.

  12. The Elusive Memristor: Properties of Basic Electrical Circuits

    Science.gov (United States)

    Joglekar, Yogesh N.; Wolf, Stephen J.

    2009-01-01

    We present an introduction to and a tutorial on the properties of the recently discovered ideal circuit element, a memristor. By definition, a memristor M relates the charge "q" and the magnetic flux [phi] in a circuit and complements a resistor R, a capacitor C and an inductor L as an ingredient of ideal electrical circuits. The properties of…

  13. Equivalent electric circuit of a carbon nanotube based molecular conductor

    CERN Document Server

    Yam, ChiYung; Wang, Fan; Li, Xiaobo; Chen, GuanHua; Zheng, Xiao; Matsuda, Yuki; Tahir-Kheli, Jamil; Goddard, William A

    2008-01-01

    We apply our first-principles method to simulate the transient electrical response through carbon nanotube based conductors under time-dependent bias voltages, and report the dynamic conductance for a specific system. We find that the electrical response of the carbon nanotube device can be mapped onto an equivalent classical electric circuit. This is confirmed by studying the electric response of a simple model system and its equivalent circuit.

  14. Device, system and method for a sensing electrical circuit

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2009-01-01

    The invention relates to a driven ground electrical circuit. A driven ground is a current-measuring ground termination to an electrical circuit with the current measured as a vector with amplification. The driven ground module may include an electric potential source V.sub.S driving an electric current through an impedance (load Z) to a driven ground. Voltage from the source V.sub.S excites the minus terminal of an operational amplifier inside the driven ground which, in turn, may react by generating an equal and opposite voltage to drive the net potential to approximately zero (effectively ground). A driven ground may also be a means of passing information via the current passing through one grounded circuit to another electronic circuit as input. It may ground one circuit, amplify the information carried in its current and pass this information on as input to the next circuit.

  15. The elusive memristor: properties of basic electrical circuits

    OpenAIRE

    Joglekar, Yogesh N.; Wolf, Stephen J.

    2008-01-01

    We present a tutorial on the properties of the new ideal circuit element, a memristor. By definition, a memristor M relates the charge q and the magnetic flux $\\phi$ in a circuit, and complements a resistor R, a capacitor C, and an inductor L as an ingredient of ideal electrical circuits. The properties of these three elements and their circuits are a part of the standard curricula. The existence of the memristor as the fourth ideal circuit element was predicted in 1971 based on symmetry argu...

  16. Electrical Equivalent Circuits of d.c. MHD Generators

    International Nuclear Information System (INIS)

    A simple electric system can be found in which the dependence between electrical parameters is identical with those in MHD generators. Such an electric system, called an electrical equivalent circuit of the MHD generator, makes it possible to calculate all electrical parameters of the generator based on the elementary principles of the theory of electrical circuits. To determine the equivalent circuit it is necessary to find out the appropriate connection system of the internal resistance and electromotive forces and to determine their values. In the paper the equivalent circuits of the generators with the segmented electrodes electrically connected in various ways are determined (generators with the electrodes connected in series, with Hall- and Faraday-connected electrodes). Constant gas dynamic parameters, constant generator cross-section, constant.magnetic field, uniformity of current density and electric field were assumed. Electrode effects, end effects and ''ion slip'' are neglected. From the equivalent circuits the following electrical terminal values of generator as voltage, current, internal resistance, electric power, brake power, ohmic losses, electrical efficiency can be easily determined. Terminal values are given as a function of geometric dimensions of the generator. Hall parameter and connection system of electrodes. (author)

  17. Layout to circuit extraction for three-dimensional thermal-electrical circuit simulation of device structures

    OpenAIRE

    Krabbenborg, B.H.; Bosma, A.; Graaff, de, G.C.; Mouthaan, A.J.

    1996-01-01

    In this paper, a method is proposed for extraction of coupled networks from layout information for simulation of electrothermal device behavior. The networks represent a three-dimensional (3-D) device structure with circuit elements. The electrical and thermal characteristics of this circuit representation are calculated with a circuit simulator. Spatial potential distributions, current flows, and temperature distributions in the device structure are calculated on the spatial coordinates. Thi...

  18. Chapter 12: Trapped Electrons as Electrical (Quantum) Circuits

    Science.gov (United States)

    Verdú, José

    2014-01-01

    In this chapter, we present a detailed model of the equivalent electric circuit of a single trapped particle in a coplanar-waveguide (CPW) Penning trap. The CPW-trap, which is essentially a section of coplanar-waveguide transmission-line, is designed to make it compatible with circuit-quantum electrodynamic architectures. This will enable a single trapped electron, or geonium atom, as a potential building block of microwave quantum circuits. The model of the trapped electron as an electric circuit was first introduced by Hans Dehmelt in the 1960s. It is essential for the description of the electronic detection using resonant tank circuits. It is also the basis for the description of the interaction of a geonium atom with other distant quantum systems through electrical (microwave) signals.

  19. Lightning, atmospheric electricity and climate change

    International Nuclear Information System (INIS)

    Temperature records indicate that a global warming of 0.5-0.7 degrees C has occurred over the past century (Hansen and Lebedeff, 1987). Whether this trend is a result of increased trace gas concentrations in the atmosphere, or simply a result of natural variability; is still not known. These temperature trends are derived from thousands of observations worldwide. However, these observations are concentrated largely over continental areas, and then mainly in the northern hemisphere's populated regions. This northern hemisphere continental bias results in large uncertainties in estimates of global temperature trends. Due to the increasing evidence that the present buildup of greenhouse gases in the atmosphere may result in an additional global warming of 1-5 degrees C by the year 2050 (IPCC, 1990), it is increasingly important to find afternative methods to monitor fluctuations in global surface temperatures. As shown by two recent studies (Williams, 1992; Price, 1993), the global atmospheric electric circuit may provide a promising afternative for monitoring future climate change

  20. Fabrication, electrical characterization, and detection application of graphene-sheet-based electrical circuits

    OpenAIRE

    Peng, Yitian; Lei, Jianping

    2014-01-01

    The distribution of potential, electric field, and gradient of square of electric field was simulated via a finite element method for dielectrophoresis (DEP) assembly. Then reduced graphene oxide sheets (RGOS)- and graphene oxide sheets (GOS)-based electrical circuits were fabricated via DEP assembly. The mechanically exfoliated graphene sheets (MEGS)-based electrical circuit was also fabricated for comparison. The electrical transport properties of three types of graphene-based electrical ci...

  1. The elusive memristor: properties of basic electrical circuits

    International Nuclear Information System (INIS)

    We present an introduction to and a tutorial on the properties of the recently discovered ideal circuit element, a memristor. By definition, a memristor M relates the charge q and the magnetic flux φ in a circuit and complements a resistor R, a capacitor C and an inductor L as an ingredient of ideal electrical circuits. The properties of these three elements and their circuits are a part of the standard curricula. The existence of the memristor as the fourth ideal circuit element was predicted in 1971 based on symmetry arguments, but was clearly experimentally demonstrated just last year. We present the properties of a single memristor, memristors in series and parallel, as well as ideal memristor-capacitor (MC), memristor-inductor (ML) and memristor-capacitor-inductor (MCL) circuits. We find that the memristor has hysteretic current-voltage characteristics. We show that the ideal MC (ML) circuit undergoes non-exponential charge (current) decay with two time scales and that by switching the polarity of the capacitor, an ideal MCL circuit can be tuned from overdamped to underdamped. We present simple models which show that these unusual properties are closely related to the memristor's internal dynamics. This tutorial complements the pedagogy of ideal circuit elements (R, C and L) and the properties of their circuits, and is aimed at undergraduate physics and electrical engineering students

  2. The elusive memristor: properties of basic electrical circuits

    Energy Technology Data Exchange (ETDEWEB)

    Joglekar, Yogesh N; Wolf, Stephen J [Department of Physics, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202 (United States)], E-mail: yojoglek@iupui.edu

    2009-07-15

    We present an introduction to and a tutorial on the properties of the recently discovered ideal circuit element, a memristor. By definition, a memristor M relates the charge q and the magnetic flux {phi} in a circuit and complements a resistor R, a capacitor C and an inductor L as an ingredient of ideal electrical circuits. The properties of these three elements and their circuits are a part of the standard curricula. The existence of the memristor as the fourth ideal circuit element was predicted in 1971 based on symmetry arguments, but was clearly experimentally demonstrated just last year. We present the properties of a single memristor, memristors in series and parallel, as well as ideal memristor-capacitor (MC), memristor-inductor (ML) and memristor-capacitor-inductor (MCL) circuits. We find that the memristor has hysteretic current-voltage characteristics. We show that the ideal MC (ML) circuit undergoes non-exponential charge (current) decay with two time scales and that by switching the polarity of the capacitor, an ideal MCL circuit can be tuned from overdamped to underdamped. We present simple models which show that these unusual properties are closely related to the memristor's internal dynamics. This tutorial complements the pedagogy of ideal circuit elements (R, C and L) and the properties of their circuits, and is aimed at undergraduate physics and electrical engineering students.

  3. Hamilton´s principle and electric circuits Tudory

    OpenAIRE

    Daniel Mayer

    2006-01-01

    In the theory of electrical or electromechanical circuits different methods are known for construction of mathematical model. In this paper another, alternative method is introduced that is based on Hamilton variational principle that is generally valid in physics.

  4. Pre-assembling electric circuits of braided conductors

    International Nuclear Information System (INIS)

    The present article has for object to give to know an innovative concept of pre-assembling electric circuits for distribution of normal and regulated power, to the work position like integral subsystems of the calls intelligent buildings

  5. Note on homological modeling of the electric circuits

    International Nuclear Information System (INIS)

    Based on a simple example, it is explained how the homological analysis may be used for modeling of the electric circuits. The homological branch, mesh and nodal analyses are presented. Geometrical interpretations are given.

  6. Model of Pulsed Electrical Discharge Machining (EDM using RL Circuit

    Directory of Open Access Journals (Sweden)

    Ade Erawan Bin Minhat

    2014-10-01

    Full Text Available This article presents a model of pulsed Electrical Discharge Machining (EDM using RL circuit. There are several mathematical models have been successfully developed based on the initial, ignition and discharge phase of current and voltage gap. According to these models, the circuit schematic of transistor pulse power generator has been designed using electrical model in Matlab Simulink software to identify the profile of voltage and current during machining process. Then, the simulation results are compared with the experimental results.

  7. Baseline characterization of electrical circuits to support plant life extension

    International Nuclear Information System (INIS)

    To (a) provide data on the relative condition of certain electrical cable in use on one of its nuclear plants, and (b) gain experience with state-of-the-art equipment and procedures for obtaining these data under the US Department of Energy (DOE) technology transfer to industry program, Southern California Edison Company (SCE) performed a program in association with EG and G Idaho, Inc., at the San Onofre Nuclear Generating Station (SONGS), Unit 1 during the Cycle IX Refueling Outage in April and May 1986. The program obtained baseline data for characterization of electrical circuits utilizing the Electrical Circuit Characterization and Diagnostic (ECCAD) System, developed by EG and G Idaho, Inc. under contract to the DOE. The ECCAD system and the SONGS 1 program to utilize it are described to show a method for characterizing electrical circuits by comparison to baseline data or to data from similar circuits. This demonstrates a capability to identify the effects of environment and aging on electrical circuits. This technique was shown to have both short-term (diagnostic) potential and long-term (characterizing aging effects) potential for use in applications where electrical circuits may be subjected to environmental conditions that can lead to cable degradation

  8. Using Hydraulic Network Models to Teach Electric Circuit Principles

    Science.gov (United States)

    Jones, Irvin; EERC (Engineering Education Research Center) Collaboration

    2013-11-01

    Unlike other engineering disciplines, teaching electric circuit principles is difficult for some students because there isn't a visual context to rely on. So concepts such as electric potential, current, resistance, capacitance, and inductance have little meaning outside of their definition and the derived mathematical relationships. As a work in progress, we are developing a tool to support teaching, learning, and research of electric circuits. The tool will allow the user to design, build, and operate electric circuits in the form of hydraulic networks. We believe that this system will promote greater learning of electric circuit principles by visually realizing the conceptual and abstract concepts of electric circuits. Furthermore, as a teaching and learning tool, the hydraulic network system can be used to teach and improve comprehension of electrical principles in K through 12 classrooms and in cross-disciplinary environments such as Bioengineering, Mechanical Engineering, Industrial Engineering, and Aeronautical Engineering. As a research tool, the hydraulic network can model and simulate micro/nano bio-electro-chemical systems. Organization within the Swanson School of Engineering at the University of Pittsburgh.

  9. Middle atmosphere electrical energy coupling

    Science.gov (United States)

    Hale, L. C.

    1989-01-01

    The middle atmosphere (MA) has long been known as an absorber of radio waves, and as a region of nonlinear interactions among waves. The region of highest transverse conductivity near the top of the MA provides a common return for global thunderstorm, auroral Birkeland, and ionospheric dynamo currents, with possibilities for coupling among them. Their associated fields and other transverse fields map to lower altitudes depending on scale size. Evidence now exists for motion-driven aerosol generators, and for charge trapped at the base of magnetic field lines, both capable of producing large MA electric fields. Ionospheric Maxwell currents (curl H) parallel to the magnetic field appear to map to lower altitudes, with rapidly time-varying components appearing as displacement currents in the stratosphere. Lightning couples a (primarily ELF and ULF) current transient to the ionosphere and magnetosphere whose wave shape is largely dependent on the MA conductivity profile. Electrical energy is of direct significance mainly in the upper MA, but electrodynamic transport of minor constituents such as smoke particles or CN may be important at other altitudes.

  10. Electric circuit element in type 2 superconductive material

    International Nuclear Information System (INIS)

    The present invention describes the fabrication process of an electric circuit element in a multi-layer orientated texture type 2 superconductor, in reversible magnetization field conditions. Element great axis is orthogonal to the c cristallographic axis of the superconductive phase, with electrical input and output contacts on each layer. 5 refs., 6 figs

  11. Introduction to Biosensors From Electric Circuits to Immunosensors

    CERN Document Server

    Yoon, Jeong-Yeol

    2013-01-01

    Introduction to Biosensors: From Electric Circuits to Immunosensors discusses underlying circuitry of sensors for biomedical and biological engineers as well as biomedical sensing modalities for electrical engineers while providing an applications-based approach to the study of biosensors with over 13 extensive, hands-on labs. The material is presented using a building-block approach, beginning with the fundamentals of sensor design and temperature sensors and ending with more complicated biosensors. This book also: Provides electrical engineers with the specific knowledge they need to understand biological sensing modalities Provides biomedical engineers with a solid background in circuits and systems Includes complete coverage of temperature sensors, electrochemical sensors, DNA and immunosensors, piezoelectric sensors and immunosensing in a micofluidic device Introduction to Biosensors: From Electric Circuits to Immunosensors aims to provide an interdisciplinary approach to biosensors that will be apprecia...

  12. Switchless charge-discharge circuit for electrical capacitance tomography

    International Nuclear Information System (INIS)

    The main factor limiting the performance of electrical capacitance tomography (ECT) is an extremely low value of inter-electrode capacitances. The charge-discharge circuit is a well suited circuit for a small capacitance measurement due to its immunity to noise and stray capacitance, although it has a problem associated with a charge injected by the analogue switches, which results in a dc offset. This paper presents a new diode-based circuit for capacitance measurement in which a charge transfer method is realized without switches. The circuit was built and tested in one channel configuration with 16 multiplexed electrodes. The performance of the elaborated circuit and a comparison with a classic charge-discharge circuit are presented. The elaborated circuit can be used for sensors with inter-electrode capacitances not lower than 10 fF. The presented approach allows us to obtain a similar performance to the classic charge-discharge circuit, but has a simplified design. A lack of the need to synchronize the analogue switches in the transmitter and the receiver part of this circuit could be a desirable feature in the design of measurement systems integrated with electrodes. (paper)

  13. Adaptive Electronic Quizzing Method for Introductory Electrical Circuit Course

    OpenAIRE

    Issa Batarseh; Feras Batarseh; Ruba Akram Amarin

    2009-01-01

    The interactive technical electronic book, TechEBook, currently under development at the University of Central Florida, provides a useful tool for engineers and scientists through unique features compared to the most used traditional electrical circuit textbooks available in the market. TechEBook has comprised the two worlds of classical circuit books and an interactive operating platform such as laptops and desktops utilizing Java Virtual Machine operator. The TechEBook provides an interacti...

  14. Updating the science of atmospheric electricity

    Science.gov (United States)

    Pinto, Osmar, Jr.; Williams, Earle R.

    2011-12-01

    XIV International Conference on Atmospheric Electricity; Rio de Janeiro, Brazil, 7-12 August 2011 The main goal of the XIV International Conference on Atmospheric Electricity (ICAE 2011) was to provide a comprehensive description of the status of knowledge in the field of atmospheric electricity, as well as to provide an opportunity for extensive interaction among researchers in this field. The history of the ICAE goes back to the first conference held in May 1954 in Portsmouth, N. H. The conference was attended by 51 scientists from 10 countries, and only three topics were addressed: fair weather electricity, thunderstorm electrification, and lightning.

  15. Students' Understanding of Direct Current Resistive Electrical Circuits

    CERN Document Server

    Engelhardt, P V; Engelhardt, Paula V.; Beichner, Robert J.

    2003-01-01

    Research has shown that both high school and university students' reasoning patterns regarding direct current resistive electric circuits often differ from the currently accepted explanations. At present, there are no standard diagnostic examinations in electric circuits. Two versions of a diagnostic instrument called Determining and Interpreting Resistive Electric circuits Concepts Tests (DIRECT) were developed, each consisting of 29 questions. The information provided by the exam provides classroom instructors a means with which to evaluate the progress and conceptual difficulties of their students and their instructional methods. It can be used to evaluate curricular packages and/or other supplemental materials for their effectiveness in overcoming students' conceptual difficulties. The analyses indicate that students, especially females, tend to hold multiple misconceptions, even after instruction. During interviews, the idea that the battery is a constant source of current was used most often in answerin...

  16. Electrical overstress (EOS) devices, circuits and systems

    CERN Document Server

    Voldman, Steven H

    2013-01-01

    Electrical Overstress (EOS) continues to impact semiconductor manufacturing, semiconductor components and systems as technologies scale from micro- to nano-electronics.  This bookteaches the fundamentals of electrical overstress  and how to minimize and mitigate EOS failures. The text provides a clear picture of EOS phenomena, EOS origins, EOS sources, EOS physics, EOS failure mechanisms, and EOS on-chip and system design.  It provides an illuminating insight into the sources of EOS in manufacturing, integration of on-chip, and system level EOS protection networks, followed by examples in spe

  17. In situ measurements of contributions to the global electrical circuit by a thunderstorm in southeastern Brazil

    Science.gov (United States)

    Thomas, J.N.; Holzworth, R.H.; McCarthy, M.P.

    2009-01-01

    The global electrical circuit, which maintains a potential of about 280??kV between the earth and the ionosphere, is thought to be driven mainly by thunderstorms and lightning. However, very few in situ measurements of electrical current above thunderstorms have been successfully obtained. In this paper, we present dc to very low frequency electric fields and atmospheric conductivity measured in the stratosphere (30-35??km altitude) above an active thunderstorm in southeastern Brazil. From these measurements, we estimate the mean quasi-static conduction current during the storm period to be 2.5 ?? 1.25??A. Additionally, we examine the transient conduction currents following a large positive cloud-to-ground (+ CG) lightning flash and typical - CG flashes. We find that the majority of the total current is attributed to the quasi-static thundercloud charge, rather than lightning, which supports the classical Wilson model for the global electrical circuit.

  18. Atmospheric electricity and aerosol-cloud interactions in earth's atmosphere

    Science.gov (United States)

    Manninen, Hanna E.; Tammet, Hannes; Mäkelä, Antti; Haapalainen, Jussi; Mirme, Sander; Nieminen, Tuomo; Franchin, Alessandro; Petäjä, Tuukka; Kulmala, Markku; Hõrrak, Urmas

    2013-05-01

    Firstly, atmospheric ions play an important role in the fair weather electricity in Earth's atmosphere. Small ions, or charged molecular clusters, carry electric currents in the atmosphere. These small ions are continuously present, and their lifetime in lower atmosphere is about one minute. It's essential to find out a connection between the production rate of cluster ions, ion-ion recombination, and ion-aerosol attachment, and their ambient concentrations, in order to understand electrical properties of air. Secondly, atmospheric ions are important for Earth's climate, due to their potential role in secondary aerosol formation, which can lead to increased number of cloud condensation nuclei (CCN), which in turn can change the cloud properties. Our aim is to quantify the connections between these two important roles of air ions based on field observations.

  19. Quantum interface between an electrical circuit and a single atom

    CERN Document Server

    Kielpinski, D; Woolley, M J; Milburn, G J; Taylor, J M

    2011-01-01

    We show how to bridge the divide between atomic systems and electronic devices by engineering a coupling between the motion of a single ion and the quantized electric field of a resonant circuit. Our method can be used to couple the internal state of an ion to the quantized circuit with the same speed as the internal-state coupling between two ions. All the well-known quantum information protocols linking ion internal and motional states can be converted to protocols between circuit photons and ion internal states. Our results enable quantum interfaces between solid state qubits, atomic qubits, and light, and lay the groundwork for a direct quantum connection between electrical and atomic metrology standards.

  20. Teaching an Electrical Circuits Course Using a Virtual Lab

    Science.gov (United States)

    Rahman, Md Zahidur

    2014-01-01

    This paper describes designing and implementing a scholarship of teaching and learning (SoTL) study in a basic electrical circuits course at LaGuardia Community College. Inspired by my understanding of Shulman's (2005) concept of "signature pedagogy" and Mazur's (2009) emphasis on student-centered approaches, and aware that our…

  1. Peculiarities of dynamics of the global electric circuit elements during very low solar activity

    International Nuclear Information System (INIS)

    Complete text of publication follows. Accumulated data about dynamics of various elements of the solar - terrestrial relationship allow us to approach the problem of the solar activity influence on the middle atmosphere with taking into account role of the ground surface electrical conductivity. A special importance of this problem appears in the 23 cycle of the solar activity (2006-2009 years). This period is characterized by unusually low values of solar UV radiation as well as of magnitudes of the solar wind magnetic field. It means that impact of the solar electromagnetic energy on the near - Earth space is much weaker than usually. The Earth global electric circuit which includes the ionosphere, the stratosphere and the ground surface as its vital components has its own specific features during considered period. In this paper we outline these peculiarities of the global electric circuit and its influence on the middle atmosphere. First of all, we will demonstrate that experimental values of the atmospheric electric field (observations at Vostok Station, Antarctica) are the lowest during the last 3 years. We claim that role of the electric conductivity of the ground surface begin to play more significant role in the dynamics of the global electric circuit. To confirm that suggestion we studied interaction between the stratospheric temperature distribution in the high latitudes in winters of 2008 - 2009 and the area of the old sea ice (pack ice) in the Arctic Ocean during the same period. We will show that the areas of the low temperatures in the polar stratosphere correspond pretty well to distribution of the pack ice in the Arctic. Our explanation of the phenomena is based on difference of electric conductivity of the ice and of the open ocean water.

  2. High-speed Integrated Circuits for electrical/Optical Interfaces

    DEFF Research Database (Denmark)

    Jespersen, Christoffer Felix

    2008-01-01

    This thesis is a continuation of the effort to increase the bandwidth of communicationnetworks. The thesis presents the results of the design of several high-speed electrical ircuits for an electrical/optical interface. These circuits have been a contribution to the ESTA project in collaboration...... with the OptCom project. The aim of the ESTA project was to investigate issues at 100 Gb/s and beyond, such as architecture and components. The OptCom project had a more tangible purpose; to create a 100 Gb/s optical/electrical transceiver demonstrator. The thesis focuses on the design of VCO, LA and...... process represents the avant-garde of InP technology, with ft and fmax well above 300 GHz. Principles of high speed design are presented and described as a useful background before proceeding to circuits. A static divider is used as an example to illustrate many of the design principles. Theory and...

  3. Modelling a river catchment using an electrical circuit analogue

    Directory of Open Access Journals (Sweden)

    C. G. Collier

    1998-01-01

    Full Text Available An electrical circuit analogue of a river catchment is described from which is derived an hydrological model of river flow called the River Electrical Water Analogue Research and Development (REWARD model. The model is based upon an analytic solution to the equation governing the flow of electricity in an inductance-capacitance-resistance (LCR circuit. An interpretation of L, C and R in terms of catchment parameters and physical processes is proposed, and tested for the River Irwell catchment in northwest England. Hydrograph characteristics evaluated using the model are compared with observed hydrographs, confirming that the modelling approach does provide a reliable framework within which to investigate the impact of variations in model input data.

  4. Circuit Theory for the Electrically Declined

    Science.gov (United States)

    Gregg, J. F.; Thornton, M. J.

    Such is the sophistication of many contemporary University Physics Courses that their followers are at ease with the finer details of the Dirac equation and have no difficulty in thinking in a many-dimensioned Hilbert-space: however they are often less confident when faced with knowing which end of a soldering iron gets hot. Spin Electronics is above all a practical science which ultimately promises to implement a new and revolutionary technology in a form which will ultimately impact everyday existence. Card-carrying theoretical physicists doubtless have their part to play in this new and exciting field, but for the rapid and successful development of this science, the importance of practical knowledge and experimental dexterity is paramount. Those who would claim proficiency as Spin Electronicians must, above all, be capable of the simple, basic skills with which every TV repair engineer is acquainted. To those devotees of Spin Electronics whose degree courses have left you electrically deprived, this chapter is dedicated to you. Evidently, in the few pages available, only the surface of this topic may be scratched, but at least the basics can be laid, topics of major confusion like transistors and transformers can be treated and signposts pointed to further study.

  5. Using graph theory for automated electric circuit solving

    Science.gov (United States)

    Toscano, L.; Stella, S.; Milotti, E.

    2015-05-01

    Graph theory plays many important roles in modern physics and in many different contexts, spanning diverse topics such as the description of scale-free networks and the structure of the universe as a complex directed graph in causal set theory. Graph theory is also ideally suited to describe many concepts in computer science. Therefore it is increasingly important for physics students to master the basic concepts of graph theory. Here we describe a student project where we develop a computational approach to electric circuit solving which is based on graph theoretic concepts. This highly multidisciplinary approach combines abstract mathematics, linear algebra, the physics of circuits, and computer programming to reach the ambitious goal of implementing automated circuit solving.

  6. Mathematical Modelling and Simulation of Electrical Circuits and Semiconductor Devices

    CERN Document Server

    Merten, K; Bulirsch, R

    1990-01-01

    Numerical simulation and modelling of electric circuits and semiconductor devices are of primal interest in today's high technology industries. At the Oberwolfach Conference more than forty scientists from around the world, in­ cluding applied mathematicians and electrical engineers from industry and universities, presented new results in this area of growing importance. The contributions to this conference are presented in these proceedings. They include contributions on special topics of current interest in circuit and device simulation, as well as contributions that present an overview of the field. In the semiconductor area special lectures were given on mixed finite element methods and iterative procedures for the solution of large linear systems. For three dimensional models new discretization procedures including software packages were presented. Con­ nections between semiconductor equations and the Boltzmann equation were shown as well as relations to the quantum transport equation. Other issues dis...

  7. Electrical characterization and an equivalent circuit model of a microhollow cathode discharge reactor

    International Nuclear Information System (INIS)

    This paper reports the electrical characterization and an equivalent circuit of a microhollow cathode discharge (MHCD) reactor in the self-pulsing regime. A MHCD reactor was prototyped for air plasma generation, and its current-voltage characteristics were measured experimentally in the self-pulsing regime for applied voltages from 2000 to 3000 V. The reactor was modeled as a capacitor in parallel with a variable resistor. A stray capacitance was also introduced to the circuit model to represent the capacitance of the circuit elements in the experimental setup. The values of the resistor and capacitors were recovered from experimental data, and the proposed circuit model was validated with independent experiments. Experimental data showed that increasing the applied voltage increased the current, self-pulsing frequency and average power consumption of the reactor, while it decreased the peak voltage. The maximum and the minimum voltages obtained using the model were in agreement with the experimental data within 2.5%, whereas the differences between peak current values were less than 1%. At all applied voltages, the equivalent circuit model was able to accurately represent the peak and average power consumption as well as the self-pulsing frequency within the experimental uncertainty. Although the results shown in this paper was for atmospheric air pressures, the proposed equivalent circuit model of the MHCD reactor could be generalized for other gases at different pressures.

  8. Java Based Symbolic Circuit Solver For Electrical Engineering Curriculum

    OpenAIRE

    Ruba Akram Amarin; Ehab Shoubaki; Issa Batarseh

    2012-01-01

    The interactive technical electronic book, TechEBook, currently under development at the University of Central Florida (UCF), introduces a paradigm shift by replacing the traditional electrical engineering course with topic-driven modules that provide a useful tool for engineers and scientists. The TechEBook comprises the two worlds of classical circuit books and interactive operating platforms such as iPads, laptops and desktops. The TechEBook provides an interactive applets screen that hold...

  9. Nonlinear lumped circuit modeling of an atmospheric pressure rf discharge

    Science.gov (United States)

    Lapke, M.; Ziegler, D.; Mussenbrock, T.; Gans, T.; Schulz-von der Gathen, V.

    2006-10-01

    The subject of our modeling approach is a specifically modified version of the atmospheric pressure plasma jet (APPJ, originally proposed by Selwyn and coworkers^1) with reduced discharge volume, the micro atmospheric pressure plasma jet (μ-APPJ). The μ-APPJ is a homogeneous nonequilibrium discharge operated with Argon or Helium as the feedstock gas and a percentage volume admixture of a molecular gas (O2, H2, N2). The efficiency of the discharge is mainly due to the dissociated and activated molecules in the effluent that can be selected depending on the application. A variety of applications in surface treatment have already been demonstrated, e.g., in semiconductor technology, restoration and bio-medicine. In this contribution we present and analyze a nonlinear lumped circuit model of the μ-APPJ. We apply a two-scale formalism. The bulk is modeled by a generalized Ohm's law, whereas the sheath is described on a considerably higher level of mathematical sophistication. The main focus lies on the spectrum of the discharge current in order to support the characterization of the discharge via model-based diagnostics, i.e., the estimation of the spatially averaged electron density from the frequency of certain self-excitated collective resonance modes. J. Park et al., Appl. Phy. Lett. 76, 288 (2000)

  10. 49 CFR 236.16 - Electric lock, main track releasing circuit.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Electric lock, main track releasing circuit. 236... Rules and Instructions: All Systems General § 236.16 Electric lock, main track releasing circuit. When an electric lock releasing circuit is provided on the main track to permit a train or an engine...

  11. The PWM auto-control circuit of neutron tube atmospheric pressure

    International Nuclear Information System (INIS)

    Ion source atmospheric pressure auto-control circuit for C/O logging neutron generator is introduced. The pulse circuit of ion source adopts zero-voltage quasi-resonant switch technique and the heating circuit for replenisher adopts PWM converter

  12. Measurements of middle-atmosphere electric fields and associated electrical conductivities

    Science.gov (United States)

    Hale, L. C.; Croskey, C. L.; Mitchell, J. D.

    1981-01-01

    A simple antenna for measuring the vertical electric field in the 'middle atmosphere' has been flown on a number of rocket-launched parachute-borne payloads. The data from the first nine such flights, launched under a variety of geophysical conditions, are presented, along with electrical conductivities measured simultaneously. The data include indications of layered peaks of several volts per meter in the mesospheric field at high and low latitudes in situations of relatively low conductivity. During an auroral 'REP' event the electric field reversed direction in the lower stratosphere, accompanied by a substantial enhancement in conductivity. The data generally do not confirm speculations based only on the extension of the thunderstorm circuit from below or the mapping of ionospheric and magnetospheric fields from above, but seem to require, in addition, internal generation processes in the middle atmosphere.

  13. Electrical properties of ions in the atmosphere of Titan

    Energy Technology Data Exchange (ETDEWEB)

    Owen, N R; Aplin, K L; Stevens, P A [Space Science and Technology Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, 0X11 OQX (United Kingdom)], E-mail: k.l.aplin@rl.ac.uk

    2008-12-01

    The Permittivity, Wave and Altimetry (PWA) package on the Huygens probe measured atmospheric electrical activity during its 14 January 2005 descent into Titan's atmosphere. Electrical mobilities of positive ions have been estimated using a combination of predictions of mass from the available chemical models, and the atmospheric properties measured by Huygens. Disc-shaped relaxation probes were used on the PWA to measure air conductivity. In this paper we present the extension of an inversion technique, originally developed to extract ion mobility information from cylindrical relaxation probe data, to the disc geometry. The maximum distance from which typical positive ion species are influenced by the electric field of the relaxation probe in Titan's troposphere and stratosphere is calculated, and found to be {approx}10{mu}m. However, loss of positive ion data from the Huygens probe prevents the application of the new technique. Based on the Huygens data, evidence for, and possible characteristics of, a global electric circuit on Titan are also discussed.

  14. THEORETICAL FOUNDATIONS OF ELECTRICAL ENGINEERING. MATHEMATICAL AND COMPUTER MODELING PROCESSES IN ELECTRIC CIRCUITS

    OpenAIRE

    A.A.ZELENKOV

    2012-01-01

    CONTENTS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 INTRODUCTION TRANSMISSION OF ELECTRIC ENERGY BY DC LINE …………………………………………………… TRANSFORMATION OF LINEAR PASSIVE ELECTRIC CIRCUITS ………………………………………………. INPUT RESISTANCE OF THE PASSIVE TWO – TERMINAL NETWORK ……………………………… DISTRIBUTION OF VOLTAGES AND CURRENTS IN ELECTRIC CIRCUITS ………………………………… ANALYSIS OF THE COMPLEX DC ELECTRIC CIRCUITS …………………………...

  15. Java Based Symbolic Circuit Solver For Electrical Engineering Curriculum

    Directory of Open Access Journals (Sweden)

    Ruba Akram Amarin

    2012-11-01

    Full Text Available The interactive technical electronic book, TechEBook, currently under development at the University of Central Florida (UCF, introduces a paradigm shift by replacing the traditional electrical engineering course with topic-driven modules that provide a useful tool for engineers and scientists. The TechEBook comprises the two worlds of classical circuit books and interactive operating platforms such as iPads, laptops and desktops. The TechEBook provides an interactive applets screen that holds many modules, each of which has a specific application in the self learning process. This paper describes one of the interactive techniques in the TechEBook known as Symbolic Circuit Solver (SymCirc. The SymCirc develops a versatile symbolic based linear circuit with a switches solver. The solver works by accepting a Netlist and the element that the user wants to find the voltage across or current on, as input parameters. Then it either produces the plot or the time domain expression of the output. Frequency domain plots or Symbolic Transfer Functions are also produced. The solver gets its input from a Web-based GUI circuit drawer developed at UCF. Typical simulation tools that electrical engineers encounter are numerical in nature, that is, when presented with an input circuit they iteratively solve the circuit across a set of small time steps. The result is represented as a data set of output versus time, which can be plotted for further inspection. Such results do not help users understand the ultimate nature of circuits as Linear Time Invariant systems with a finite dimensional basis in the solution space. SymCirc provides all simulation results as time domain expressions composed of the basic functions that exclusively include exponentials, sines, cosines and/or t raised to any power. This paper explains the motivation behind SymCirc, the Graphical User Interface front end and how the solver actually works. The paper also presents some examples and

  16. 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.

  17. Dynamical properties of electrical circuits with fully nonlinear memristors

    CERN Document Server

    Riaza, Ricardo

    2010-01-01

    The recent design of a nanoscale device with a memristive characteristic has had a great impact in nonlinear circuit theory. Such a device, whose existence was predicted by Leon Chua in 1971, is governed by a charge-dependent voltage-current relation of the form $v=M(q)i$. In this paper we show that allowing for a fully nonlinear characteristic $v=\\eta(q, i)$ in memristive devices provides a general framework for modeling and analyzing a very broad family of electrical and electronic circuits; Chua's memristors are particular instances in which $\\eta(q,i)$ is linear in $i$. We examine several dynamical features of circuits with fully nonlinear memristors, accommodating not only charge-controlled but also flux-controlled ones, with a characteristic of the form $i=\\zeta(\\varphi, v)$. Our results apply in particular to Chua's memristive circuits; certain properties of these can be seen as a consequence of the special form of the elastance and reluctance matrices displayed by Chua's memristors.

  18. Pupils' understanding of simple electrical circuits. Some implications for instruction

    Science.gov (United States)

    Shipstone, David

    1988-03-01

    There have been many studies worldwide of children's understanding of basic electrical concepts so that there is now quite a clear picture of many of their difficulties. By contrast, work on remediation is in its infancy. The article describes research findings concerning children's difficulties with the concepts of circuit, current and electrical energy and discusses some possible approaches to instruction which arise in the light of these findings. Much of the research carried out has been within the paradigm of constructivist psychology which views all human beings as prototypical scientists, constructing hypotheses and testing these against experience as their way of understanding the world around them. In seeking to understand electrical phenomena children construct a variety of explanatory conceptual models, some of which they then hold very tenaciously.

  19. Reduce of Threshold of Laser Inducing Breakdown in Atmosphere by Introducing an Electric Spark

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xian-Bin; SHI Wei; LI Hua

    2005-01-01

    @@ We report laser-generated plasmas in atmosphere with electrical spark generated by a synchronization circuit.The breakdown thresholds under the conditions that the electrical spark is used and not used are compared.The breakdown threshold has a distinct decrease after the electrical spark is used. Breakdown thresholds as afunction of atmosphere pressure have also been measured at laser wavelengths 532nm and 1064 nm for the laserpulse width of 15ns. We also discuss the principle and performances of the ionized atmosphere by Nd:YAGlaser under the condition of electrical spark introduction. Multiphoton ionization and cascade ionization playimportant roles in the whole process of atmosphere ionization. The free electron induced by electrical spark cansupply the initialization free electron number for multiphoton ionization and cascade ionization. A model forbreakdown in atmosphere, which is in good agreement with the experimental results, is described.

  20. 5th International Conference on Atmospheric Electricity

    CERN Document Server

    Reiter, Reinhold; Landsberg, Helmut

    1976-01-01

    These Proceedings are published to give a full account of the Fifth International Conference on Atmospheric Electricity held in September 1974 in Garmisch-Partenkirchen in the Bavarian Alps in Germany. Traditionally, the Proceedings of these Conferences have served as reference books updating the textbooks and monographs on Atmospheric Electricity. As treated by these Conferences, Atmos­ pheric Electricity covers all aspects of this science, including the processes and problems which reach out into the Earth's environment as well as analogous processes on other planets and on the Moon. A history of these Conferences, an account of their purpose, and an outline of the scope and the preparation is to be found at the end of these Proceedings. There, also the Business Meetings of the involved organizations are mentioned. The Proceedings closely follow the original program and are accordingly organized into "Sessions". The papers printed in each "Session" in this book are the ones which were accepted for the sess...

  1. Extinction properties of electric arcs in high voltage circuit breakers

    Science.gov (United States)

    Ziani, A.; Moulai, H.

    2009-05-01

    This paper is devoted to the development of a 0D model of the electric arc extinction in SF6 high voltage circuit breakers taking into account the thermal radiation of the plasma, in addition to the conduction and convection phenomena. The Stefan-Boltzmann equation is coupled with the heat equation, and both equations are solved simultaneously in order to follow the evolution of the arc voltage and the conductance of the thermal plasma as functions of time. The obtained results are found to be in good agreement with experimental recordings.

  2. Basic electric circuit theory a one-semester text

    CERN Document Server

    Mayergoyz, Isaak D

    1996-01-01

    This is the only book on the market that has been conceived and deliberately written as a one-semester text on basic electric circuit theory. As such, this book employs a novel approach to the exposition of the material in which phasors and ac steady-state analysis are introduced at the beginning. This allows one to use phasors in the discussion of transients excited by ac sources, which makes the presentation of transients more comprehensive and meaningful. Furthermore, the machinery of phasors paves the road to the introduction of transfer functions, which are then used in the analysis of tr

  3. Electrical Circuit Modeling for Somatosensory Evoked Fields in Magnetoencephalogram

    Science.gov (United States)

    Ishihara, Shinichi; Tanaka, Keita; Uchikawa, Yoshinori; Kobayashi, Koichiro

    We measured somatosensory evoked fields (SEFs) by applying on electric stimulus to the right finger (medium nerve and ulnar nerve) and the right ankle (posterior tibial nerve) with a 39-channel SQUID system, which can measure magnetic-field components perpendicular (Br) and tangential to the scalp (Bθ, Bφ) simultaneously. To investigate the relationship between phase lag and stimulus repetition frequency (SRF), the delay time of a component synchronized with the SRFs was calculated by convoluting the reference signal and the measured SEF. The phase lag was linear to SRF for at least three different ranges of the SRFs in each SEF data. We simulated the SEF responses based on the results of phase-lag characteristics and determined the parameters for modeling. To quantitatively characterize the component of SEF, we proposed electric circuit model for the characteristics of phase-lag of the SEF with stimuli frequency.

  4. Adaptive Electronic Quizzing Method for Introductory Electrical Circuit Course

    Directory of Open Access Journals (Sweden)

    Issa Batarseh

    2009-08-01

    Full Text Available The interactive technical electronic book, TechEBook, currently under development at the University of Central Florida, provides a useful tool for engineers and scientists through unique features compared to the most used traditional electrical circuit textbooks available in the market. TechEBook has comprised the two worlds of classical circuit books and an interactive operating platform such as laptops and desktops utilizing Java Virtual Machine operator. The TechEBook provides an interactive applets screen that holds many modules, in which each had a specific application in the self learning process. This paper describes one of the interactive techniques in the TechEBook known as, QuizMe, for evaluating the readers’ performance and the overall understanding for all subjects at any stage. The QuizMe will be displayed after each section in the TechEBook for the user to evaluate his/her understanding, which introduces the term me-learning, as a comprehensive full experience for self or individualized education. In this paper, a practical example of applying the QuizMe feature is discussed as part of a basic electrical engineering course currently given at the University of Central Florida.

  5. Inferring convective responses to El Niño with atmospheric electricity measurements at Shetland

    International Nuclear Information System (INIS)

    Pacific ocean temperature anomalies associated with the El Niño–Southern Oscillation (ENSO) modulate atmospheric convection and hence thunderstorm electrification. The generated current flows globally via the atmospheric electric circuit, which can be monitored anywhere on Earth. Atmospheric electricity measurements made at Shetland (in Scotland) display a mean global circuit response to ENSO that is characterized by strengthening during ‘El Niño’ conditions, and weakening during ‘La Niña’ conditions. Examining the hourly varying response indicates that a potential gradient (PG) increase around noon UT is likely to be associated with a change in atmospheric convection and resultant lightning activity over equatorial Africa and Eastern Asia. A secondary increase in PG just after midnight UT can be attributed to more shower clouds in the central Pacific ocean during an ‘El Niño’.

  6. An investigation of algebraic quantum dynamics for mesoscopic coupled electric circuits with mutual inductance

    Science.gov (United States)

    Pahlavani, H.; Kolur, E. Rahmanpour

    2016-08-01

    Based on the electrical charge discreteness, the Hamiltonian operator for the mutual inductance coupled quantum mesoscopic LC circuits has been found. The persistent current on two driven coupled mesoscopic electric pure L circuits (two quantum loops) has been obtained by using algebraic quantum dynamic approach. The influence of the mutual inductance on energy spectrum and quantum fluctuations of the charge and current for two coupled quantum electric mesoscopic LC circuits have been investigated.

  7. Circuit modeling of the electrical impedance: I. Neuromuscular disease

    International Nuclear Information System (INIS)

    Multifrequency electrical impedance myography (MFEIM) in the 3–300 kHz range was applied to 68 subjects representing 19 different neuromuscular diseases, and the impedances analyzed using the 5-element circuit model. Depending on severity, the ‘cellular’ parameters r2, r3, 1/c1 and 1/c2 were found to be as much as 10- to 20-fold larger than for normal subjects (taking age and girth into account), but in almost every case the extracellular fluid parameter r1 was at most only marginally affected. Strong correlations are found between r2 and 1/c1, but in the case of ALS that breaks down when c1 (representing the muscle fiber membrane capacitance) falls below half the normal value. Also, c2 (tentatively associated with intracellular organelle membranes) was found to be the most sensitive to disease progress in ALS, about three times more so than the 50 kHz phase, already suggested for use in clinical drug testing. We conclude that following parameters obtained using the combined MFEIM/5-element circuit analysis scheme offer a reliable, non-invasive and objective way of characterizing muscle in neuromuscular disease or during clinical drug testing. (paper)

  8. Extragalactic Jets as Electrical Circuits and Transmission Lines

    Science.gov (United States)

    Kronberg, Philipp

    2014-10-01

    I describe the first attempt to measure a current in an extended radio galaxy jet: ~1018A at ~50 kpc from the elliptical galaxy's ultra-compact nucleus. This class of jet is known to transport its magnetic energy ``intact'', up to supragalactic scales. I discuss plasma parameters for 3C303 and recent attempts to measure its jet axial current. I discuss analogies with both electrical circuits, - and transmission lines. Power is delivered into a ``load'', whose impedance, Z, is close to that of free space, and the jet power flow I2 Z is ~1035 erg s-1 - broadly consistent with astronomically measured total power outputs, luminosities and lifetimes of AGN-powered radio lobes.The current and power levels are also consistent with SMBH accretion disk model predictions by Stirling Colgate, H. Li, V. Pariev, J. Finn, and others, beginning with Lovelace 1976 (Nature). A further analogy with transmission lines shows how the supragalactic power flows can be disrupted by a complex impedance in the ``circuit.'' Reactive components in space, i.e. a complex Z, can disrupt, reflect or deflect the power flow. This could explain the wide variety of magneto-plasma configurations seen in these systems. Funded by NSERC Discovery Grant A5713.

  9. Electric circuit element in type 2 supraconductive material. Element de circuit electrique en materiau supraconducteur de type 2

    Energy Technology Data Exchange (ETDEWEB)

    Tournier, R.; Sulpice, A.; Lejay, P.; Chaminade, J.P.

    1991-07-12

    The present invention describes the fabrication process of an electric circuit element in a multi-layer orientated texture type 2 superconductor, in reversible magnetization field conditions. Element great axis is orthogonal to the c cristallographic axis of the superconductive phase, with electrical input and output contacts on each layer. 5 refs., 6 figs.

  10. Modeling DC-circuit-breakers for long distance electricity transmission

    Science.gov (United States)

    Agnihotri, Ashutosh; Ebert, Ute; Hundsdorfer, Willem

    2014-10-01

    Modeling a circuit-breaker is a multiple timescale problem which involves a cascade of physical processes from avalanche phase to streamer, spark and post discharge phase, with a transition phase between each pair of processes. In particular, Jin Zhang and Bert van Heesch at Eindhoven University of Technology investigate now whether the conventional SF6 can be replaced by supercritical nitrogen. We focus on modeling space charge effects, gas heating and secondary electron emission from cathode. We develop a two-dimensional drift-diffusion model for streamers coupled to the Euler equations for the gas to study the related phenomena. We perform simulations to capture thermal shocks and induced pressure waves caused by the electrical breakdown of the surrounding gas. We include heat exchange mechanisms between the electrons/ions and the surrounding gas.

  11. Fourth Graders' Framing of an Electric Circuits Task

    Science.gov (United States)

    Winters, Victoria; Hammer, David

    2009-11-01

    Previous work shows that college students have more difficulty lighting a bulb with a single wire and a battery than with two wires [1], results that have informed the design of activities [2]. We present some unexpected findings from two 4th grade classes engaged in a 15-hour inquiry module on electric circuits. Students successfully lit the bulb with a single wire in a variety of ways, but students from both classes showed and expressed the view that the bulb must be in direct contact with a battery in order for it to light. We suggest this arose from students framing the task as a building activity, and we analyze two classroom episodes in support of this interpretation.

  12. New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

    Science.gov (United States)

    Robin-Jouan, Ph.; Yousfi, M.

    2007-12-01

    The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure, namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively. Based on solving a multi-term electron Boltzmann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions. The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K. These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests.

  13. New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

    Institute of Scientific and Technical Information of China (English)

    Ph.ROBIN-JOUAN; M.YOUSFI

    2007-01-01

    The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure,namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively.Based on solving a multi-term electron Boltzmann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions.The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K.These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests.

  14. New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

    International Nuclear Information System (INIS)

    The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure, namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively. Based on solving a multi-term electron Boltzmann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions. The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K. These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests

  15. 30 CFR 18.51 - Electrical protection of circuits and equipment.

    Science.gov (United States)

    2010-07-01

    ... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES... the junction with the main circuit when the branch-circuit conductor(s) has a current carrying capacity less than 50 percent of the main circuit conductor(s), unless the protective device(s) in the...

  16. Analogue Electrical Circuit for Simulation of the Duffing-Holmes Equation

    DEFF Research Database (Denmark)

    Tamaseviciute, E.; Tamasevicius, A.; Mykolaitis, G.; Bumeliene, S.; Lindberg, Erik

    2008-01-01

    An extremely simple second order analogue electrical circuit for simulating the two-well Duffing-Holmes mathematical oscillator is described. Numerical results and analogue electrical simulations are illustrated with the snapshots of chaotic waveforms, phase portraits (Lissajous figures) and...

  17. The Electron Runaround: Understanding Electric Circuit Basics through a Classroom Activity

    Science.gov (United States)

    Singh, Vandana

    2010-01-01

    Several misconceptions abound among college students taking their first general physics course, and to some extent pre-engineering physics students, regarding the physics and applications of electric circuits. Analogies used in textbooks, such as those that liken an electric circuit to a piped closed loop of water driven by a water pump, do not…

  18. Investigation of Status of Primary School Teaching Students as Regards Installing and Figuring Out Electrical Circuits

    OpenAIRE

    ÇELİK, Harun; PEKTAŞ, Hüseyin Miraç; Murat DEMİRBAŞ

    2013-01-01

    This study is carried out to present students’ problems which are about electric circuit experiments and are faced during the experiments process in Science and Technology Laboratory Course. The problems are associated with setting up simple electric circuits, fi guring out and using circuit elements (resistances in series, parallel and mixed connection). Researchers used special case method because the method provides utilizing both qualitative and quantitative methods in this study. Firstly...

  19. Modelling a point absorbing wave energy converter by the equivalent electric circuit theory: A feasibility study

    Science.gov (United States)

    Hai, Ling; Svensson, Olle; Isberg, Jan; Leijon, Mats

    2015-04-01

    There is a need to have a reliable tool to quickly assess wave energy converters (WECs). This paper explores whether it is possible to apply the equivalent electric circuit theory as an evaluation tool for point absorbing WEC system modelling. The circuits were developed starting from the force analysis, in which the hydrodynamic, mechanical, and electrical parameters were expressed by electrical components. A methodology on how to determine the parameters for electrical components has been explained. It is found that by using a multimeter, forces in the connection line and the absorbed electric power can be simulated and read directly from the electric circuit model. Finally, the circuit model has been validated against the full scale offshore experiment. The results indicated that the captured power could be predicted rather accurately and the line force could be estimated accurately near the designed working condition of the WEC.

  20. Ground water flow analysis of potential low level radioactive waste disposal sites using electrical circuit analogies

    International Nuclear Information System (INIS)

    The analogy between electrical circuits and ground water flow systems is developed. The analogy previously required an extensive electrical network to obtain the desired results. This paper deals with adapting the analogy to a computer based electrical circuit analysis program. The application of the analogy is then demonstrated through a preliminary ground water modeling of a proposed Low-Level Radioactive Waste Disposal Site in Illinois, USA. (orig.)

  1. Applications of Electrified Dust and Dust Devil Electrodynamics to Martian Atmospheric Electricity

    Science.gov (United States)

    Harrison, R. G.; Barth, E.; Esposito, F.; Merrison, J.; Montmessin, F.; Aplin, K. L.; Borlina, C.; Berthelier, J. J.; Déprez, G.; Farrell, W. M.; Houghton, I. M. P.; Renno, N. O.; Nicoll, K. A.; Tripathi, S. N.; Zimmerman, M.

    2016-04-01

    Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kV m-1 to 100 kV m-1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m-1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)—MicroARES (Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ electrical measurements.

  2. Carnegie Institution Atmospheric-Electricity and Meteorological Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Department of Terrestrial Magnetism at the Carnegie Institute of Science conducted observations of atmospheric electricity and magnetic storms. In addition to...

  3. Displacement damage analysis and modified electrical equivalent circuit for electron and photon-irradiated silicon solar cells

    Science.gov (United States)

    Arjhangmehr, Afshin; Feghhi, Seyed Amir Hossein

    2014-10-01

    Solar modules and arrays are the conventional energy resources of space satellites. Outside the earth's atmosphere, solar panels experience abnormal radiation environments and because of incident particles, photovoltaic (PV) parameters degrade. This article tries to analyze the electrical performance of electron and photon-irradiated mono-crystalline silicon (mono-Si) solar cells. PV cells are irradiated by mono-energetic electrons and poly-energetic photons and immediately characterized after the irradiation. The mean degradation of the maximum power (Pmax) of silicon solar cells is presented and correlated using the displacement damage dose (Dd) methodology. This method simplifies evaluation of cell performance in space radiation environments and produces a single characteristic curve for Pmax degradation. Furthermore, complete analysis of the results revealed that the open-circuit voltage (Voc) and the filling factor of mono-Si cells did not significantly change during the irradiation and were independent of the radiation type and fluence. Moreover, a new technique is developed that adapts the irradiation-induced effects in a single-cell equivalent electrical circuit and adjusts its elements. The "modified circuit" is capable of modeling the "radiation damage" in the electrical behavior of mono-Si solar cells and simplifies the designing of the compensation circuits.

  4. INFLUENCE OF CONTACT NETWORK PARAMETERS ON VALUE OF CURRENT RISE SPEED DURING SHORT CIRCUIT IN POWER CIRCUITS OF ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    O. A. Karzova

    2014-03-01

    Full Text Available Purpose. Influence investigation of contact system parameters on current rate of rise during short circuit, and the difference of these parameter values under different connection diagrams of traction motors in the power circuit. Methodology. The mathematical model and method for determining the effect of the contact system parameters, such as inductance and active resistance of the contact wire, on rise speed during the short circuit current were offered. Besides that, it is determined the influence of current speeds on their difference in power circuits of DC electric locomotive in different points of short circuit, different variants of traction electric engines connection and different distances of electric locomotives from the traction substation. The proposed model and method can be used for any type of electric DC locomotive at any point of a short circuit in traction engine circuit. Findings. Qualitative and quantitative influence of contact system parameters on values of current rise speed during short circuit and on the differences value of these parameters with different connection diagram of traction electric engines was established. Originality. The investigation method concerning determination of the influence of contact system parameters on current rise speed in short circuit and on the difference of these parameters on different distances of electric locomotives from traction substation was proposed. Practical value. The results can be used in selection of protective devices of rolling stock power circuits, where the main parameter is the current rise speed during the short circuit.

  5. ELECTRICAL SIMULATION METHODOLOGY DEDICATED TO EMC DIGITAL CIRCUITS EMISSIONS ANALYSIS ON PCB

    OpenAIRE

    Dienot, J.M.; Demarcq, Yves

    2002-01-01

    Electronic CAO tools are actually efficient and helpful for circuit designers separately in many domains : RF, low-signal circuits, electromagnetic, power circuits...Nevertheless, they have to take in account the reconciliation in the future of complex electronic commands boards associated to power energy converters system integrated on closer structures, and the upsurge of electric/electromagnetic couplings in a large frequency band . In this context, we present a global modelling methodolog...

  6. Using Electrical Simulation Software to Understand Electrical Quantities in Resistive Circuits

    Directory of Open Access Journals (Sweden)

    André Schwantes

    2016-02-01

    Full Text Available This paper describes the development and application of a workshop presented for high school physics teachers, in order to apply the use of electrical simulation software for teaching the basics of resistive circuits. The workshop was developed aiming at the use of active learning strategies and the concepts of David Ausubel’s Meaningful Learning theory. These activities workshops were developed in a practical way, using the electrical simulation software to illustrate a scenario where students are encouraged to engage more actively in their learning. As a result of this workshop, an increase in the importance of the use of new technologies in the classroom was evidenced when used in accordance with the teaching-learning methodologies that promote a more active participation of students.

  7. Design Failures in Aerospace Electrical Systems(The Identification of Sneak Circuits

    Directory of Open Access Journals (Sweden)

    C. Goodchild

    2000-01-01

    Full Text Available The malfunction or failure of an aircraft electrical system because signal or power flow paths were unintentionally designed into the electrical circuit, is known to be the cause of several major failures of engineering systems. These unintentional signal or power paths are called sneak circuits. The nature of Sneak Circuits was first considered after they had been identified as the cause of some spectacular and expensive rocket failures in the United States space programme. This paper reviews the status of Sneak Circuit Analysis (SCA and presents a general systematic approach the author has devised to identify sneak circuits during the circuits design phase. The application of the method of SCA is illustrated with a case study. The paper makes a case to take the investigation of an electrical failure or malfunction beyond the identification of a failed component to include a search for possible sneak circuits. The obvious fact that could result from the discovery of a sneak circuit is the shift in legal responsibility from the component manufacturer to the circuit designer.

  8. Technological Literacy Learning with Cumulative and Stepwise Integration of Equations into Electrical Circuit Diagrams

    Science.gov (United States)

    Ozogul, G.; Johnson, A. M.; Moreno, R.; Reisslein, M.

    2012-01-01

    Technological literacy education involves the teaching of basic engineering principles and problem solving, including elementary electrical circuit analysis, to non-engineering students. Learning materials on circuit analysis typically rely on equations and schematic diagrams, which are often unfamiliar to non-engineering students. The goal of…

  9. 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.

  10. High school physics teacher forms of thought about simple electric circuits

    International Nuclear Information System (INIS)

    According to some researches on students and on science teachers, they have same conceptual difficulties about simple electric circuits and these affect their further learning or/and teaching. [2], [5], [8], [9], [11], [13]. The main aim of this study was to investigate in-service high school physics teachers form of thought about simple electric circuits. In this purpose a test that was developed by Kucukozer [7], contains eight questions related to simple electric circuits was applied to in-service physics teachers (25 subjects) in various Anatolian Teacher High School in Turkey. After analyzing and evaluating of their data, it was found that, the physics teachers have conceptual difficulties about simple electric circuits, especially the concepts about source of stationary current and current usage

  11. Simulation of electrical machines, circuits and control systems using finite element method and system simulator

    OpenAIRE

    Kanerva, Sami

    2005-01-01

    The aim of this study is to provide a combined simulation environment capable of modelling and analyzing the interaction between electrical machines and controlled converters. For that purpose, two indirect methods are presented for coupling the magnetic field computation of electrical machines with the simulation of circuits and control systems. The methods are implemented for the system simulator SIMULINK as functional blocks, which solve the field and circuit equations relating to the elec...

  12. Frequency response of an electric equivalent circuit for a skin type system

    OpenAIRE

    F. Gómez-Aguilar; J. Bernal-Alvarado; J. Rosales-García; M. Guía-Calderón; T Córdova-Fraga; M. Sosa-Aquino

    2011-01-01

    In the present work we consider a theoretical representation of an electrical circuit equivalent to a multilayer biological system. The proposed system is of the skin type, containing epidermis, dermis and the subcutaneous tissue. Electrical circuit theory is used, and the behavior of the system is shown in the form of Nyquist and Bode plots. The proposed theoretical approach is a general treatment to describe the bioelectrical transport in a three-layered system, especially in the ele...

  13. Global surface temperatures and the atmospheric electrical circuit

    Science.gov (United States)

    Price, Colin

    1993-01-01

    To monitor future global temperature trends, it would be extremely useful if parameters nonlinearly related to surface temperature could be found, thereby amplifying any warming signal that may exist. Evidence that global thunderstorm activity is nonlinearly related to diurnal, seasonal and interannual temperature variations is presented. Since global thunderstorm activity is also well correlated with the earth's ionospheric potential, it appears that variations of ionospheric potential, that can be measured at a single location, may be able to supply valuable information regarding global surface temperature fluctuations. The observations presented enable a prediction that a 1 percent increase in global surface temperatures may result in a 20 percent increase in ionospheric potential.

  14. Global Electric Circuit Diurnal Variation Derived from Storm Overflight and Satellite Optical Lightning Datasets

    Science.gov (United States)

    Mach, Douglas M.; Blakeslee, R. J.; Bateman, M. J.; Bailey, J. C.

    2011-01-01

    We have combined analyses of over 1000 high altitude aircraft observations of electrified clouds with diurnal lightning statistics from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) to produce an estimate of the diurnal variation in the global electric circuit. Using basic assumptions about the mean storm currents as a function of flash rate and location, and the global electric circuit, our estimate of the current in the global electric circuit matches the Carnegie curve diurnal variation to within 4% for all but two short periods of time. The agreement with the Carnegie curve was obtained without any tuning or adjustment of the satellite or aircraft data. Mean contributions to the global electric circuit from land and ocean thunderstorms are 1.1 kA (land) and 0.7 kA (ocean). Contributions to the global electric circuit from ESCs are 0.22 kA for ocean storms and 0.04 kA for land storms. Using our analysis, the mean total conduction current for the global electric circuit is 2.0 kA.

  15. Enhanced interaction between a mechanical oscillator and two coupled resonant electrical circuits

    CERN Document Server

    Dmitriev, A V

    2014-01-01

    This paper reports result of calculation and experimental realization of an electromechanical system that consists of a high-Q mechanical oscillator parametrically coupled in the manner of a capacitive transducer with a RF circuit, which is in turn inductively coupled with another RF circuit. The system operates in the resolved sideband regime when the mechanical oscillator's frequency is larger than the electrical circuits' bandwidths. Using two coupled RF circuits allowed one to enhance the interaction between them and the mechanical oscillator which is one of flexural vibrational modes of a free-edge circular silicon wafer. Such a coupled electromechanical system can be used as a high-sensitive capacitive vibration sensor.

  16. Electric circuit analysis for plasma breakdown in JT-60SA

    International Nuclear Information System (INIS)

    To obtain stable plasma breakdown and for designing the details of a power supply system in JT-60SA, a precise evaluation of the magnetic field performance using an accurate circuit analysis model has to be conducted. This evaluation should include AC/DC converters such as thyristor converters and a high voltage generation circuit which consists of a DC current interrupter and a resistor set. In this paper, the preparation procedure of the analysis model is presented. Using this modeling method, a circuit analysis including not only complex interactions but also nonlinear phenomenon can be performed. As one of the applications of it, a circuit analysis of the tokamak system JT-60SA is demonstrated using the PSIM code. Specifically, some circuit analysis results of plasma breakdown at t=0 - 60 ms are shown using an ideal voltage source and a thyristor converter model for comparison. Then, the voltage fluctuations of the generator (H-MG, 400 MVA) at plasma initiation and their influence are also described. (author)

  17. Investigation on no-load mechanical endurance and electrical degradation of a circuit breaker model under short circuit current interruption

    OpenAIRE

    Suwanasri, Thanapong

    2006-01-01

    The demand on reducing circuit breaker failure, extending service life, increasing equipment reliability and lowering the related operating and maintenance costs are nowadays of prime importance for the electricity supply network. According to statistics, the major failure mode is originated from operating mechanism, whereas interrupter has the highest percentage of failure in high voltage component. Thus, the method to facilitate the assessment of internal mechanical conditions by using comm...

  18. Generalisation of Helmholtz-Thevenin theorem to three-phase electrical circuits

    OpenAIRE

    Gheorghe MIHAI

    2009-01-01

    The scope of this paper is to determine the generalized form for equivalent tension generator theorem (Helmholtz-Thevenin theorem) for three-phase electrical circuit. Any complicated electrical power systems we can reduce depending on any three-phase electrical consumer to a three-phase electrical generator that has certain internal impedance. Starting with this assumption, we have demonstrated the way to obtain the electromotive voltages for an equivalent generator and its internal impedances.

  19. Measurements of the vertical atmospheric electric field and of the electrical conductivity with stratospheric balloons

    Science.gov (United States)

    Iversen, I. B.; Madsen, M. M.; Dangelo, N.

    1985-01-01

    Measurements of the atmospheric (vertical) electric field with balloons in the stratosphere are reported. The atmospheric electrical conductivity is also measured and the current density inferred. The average vertical current shows the expected variation with universal time and is also seen to be influenced by external (magnetospheric) electric fields.

  20. Predictive maintenance of electrical components through computer-controlled acquisition and trending of standard circuit parameters

    International Nuclear Information System (INIS)

    Condition monitoring techniques are finding greater acceptance within many power plant maintenance organizations as plant operators develop predictive maintenance programs. This paper describes a proven condition monitoring technique and it's application in an electrical circuit predictive maintenance program. The technique performs a series of standard electrical measurements, under computer control, using a pre-defined test methodology. The test data is evaluated by utilizing statistical analysis methods and by comparisons through graphical representations. These methods allow comparisons with data from similar circuits or with baseline measurements. Circuit and component degradation appears as a change in one or more of the measured electrical parameters. Trending these parameters over time provides for early identification of circuit degradation. Incorporating this technique into a plant predictive maintenance program will switch maintenance personnel from a reactive to proactive position

  1. Teaching Electric Circuits with Multiple Batteries: A Qualitative Approach

    Science.gov (United States)

    Smith, David P.; van Kampen, Paul

    2011-01-01

    We have investigated preservice science teachers' qualitative understanding of circuits consisting of multiple batteries in single and multiple loops using a pretest and post-test method and classroom observations. We found that most students were unable to explain the effects of adding batteries in single and multiple loops, as they tended to use…

  2. Electric Circuits: A New Approach--Part 1.

    Science.gov (United States)

    Shipstone, David; Cheng, Peter C-H.

    2001-01-01

    Shows how box diagrams and AVOW diagrams may be used to solve problems concerning networks of resistors that obey Ohm's Law. Presents outcomes and feedback from students and teachers. Concludes with suggestions as to how these techniques might be incorporated into the teaching of basic circuit theory. (Contains 22 references.) (DDR)

  3. Physics of Atmospheric Electric Discharges in Gases: An Informal Introduction

    CERN Document Server

    Treumann, R A; Parrot, M

    2007-01-01

    A short account of the physics of electrical discharges in gases is given in view of its historical evolution and application to planetary atmospheres. As such it serves as an introduction to the articles on particular aspects of electric discharges contained in this book, in particular in the chapters on lightning and the violent discharges which in the recent two decades have been observed to take place in Earth's upper atmosphere. In addition of briefly reviewing the early history of gas discharge physics we discuss the main parameters affecting violent atmospheric discharges like collision frequency, mean free path and critical electric field strength. Any discharge current in the atmosphere is clearly carried only by electrons. Above the lower bound of the mesosphere the electrons must be considered magnetized with the conductivity becoming a tensor. Moreover, the collisional mean free path in the upper atmosphere becomes relatively large which lowers the critical electric field there and more easily ena...

  4. Electrical cycle in the Earth's atmosphere

    International Nuclear Information System (INIS)

    A qualitative physical picture of atmospheric electricity as a secondary phenomenon of atmospheric water circulation is presented using the key electrical atmospheric processes, their average observed parameters, and a detailed analysis of separate processes as the basis. The electrical processes begin with the charging of aerosols at kilometer altitudes due to aerosols of different aggregate states colliding with one another. Atmospheric electric currents arise from the fall speed difference (in cumulus clouds) between mass-different positively and negatively charged aerosols, resulting in aerosols with a negative charge of, on average, (25-30)e at the lower edge of a cloud. This creates an electric field between Earth and the cloud, and the subsequent penetration of streams of warm wet air into the cloud causes the atmosphere to electrically break down, thus producing lightning flashes. At the same time, these processes cause aerosols to grow and to fall as rain onto Earth. Processes in atmospheric air, including those involving aerosols, electrons, and ions, provide a unified physical picture of electric phenomena in the terrestrial atmosphere. (reviews of topical problems)

  5. A simple atmospheric electrical instrument for educational use

    CERN Document Server

    Bennett, A J

    2007-01-01

    Electricity in the atmosphere provides an ideal topic for educational outreach in environmental science. To support this objective, a simple instrument to measure real atmospheric electrical parameters has been developed and its performance evaluated. This project compliments educational activities undertaken by the Coupling of Atmospheric Layers (CAL) European research collaboration. The new instrument is inexpensive to construct and simple to operate, readily allowing it to be used in schools as well as at the undergraduate University level. It is suited to students at a variety of different educational levels, as the results can be analysed with different levels of sophistication. Students can make measurements of the fair weather electric field and current density, thereby gaining an understanding of the electrical nature of the atmosphere. This work was stimulated by the centenary of the 1906 paper in which C.T.R. Wilson described a new apparatus to measure the electric field and conduction current densi...

  6. Ground-based instrumentation for measurements of atmospheric conduction current and electric field at the South Pole

    Science.gov (United States)

    Byrne, G. J.; Benbrook, J. R.; Bering, E. A.; Few, A. A.; Morris, G. A.; Trabucco, W. J.; Paschal, E. W.

    1993-01-01

    Attention is given to instruments constructed to measure the atmospheric conduction current and the atmospheric electric field - two fundamental parameters of the global-electric circuit. The instruments were deployed at the Amundsen-Scott South Pole Station in January 1991 and are designed to operate continuously for up to one year without operator intervention. The atmospheric current flows into one hemisphere, through the electronics where it is measured, and out the other hemisphere. The electric field is measured by a field mill of the rotating dipole type. Sample data from the first days of operation at the South Pole indicate variations in the global circuit over time scales from minutes to hours to days.

  7. Self-control of chaos in neural circuits with plastic electrical synapses

    Science.gov (United States)

    Zhigulin, V. P.; Rabinovich, M. I.

    2004-10-01

    Two kinds of connections are known to exist in neural circuits: electrical (also called gap junctions) and chemical. Whereas chemical synapses are known to be plastic (i. e., modifiable), but slow, electrical transmission through gap junctions is not modifiable, but is very fast. We suggest the new artificial synapse that combines the best properties of both: the fast reaction of a gap junction and the plasticity of a chemical synapse. Such a plastic electrical synapse can be used in hybrid neural circuits and for the development of neural prosthetics, i.e., implanted devices that can interact with the real nervous system. Based on the computer modelling we show that such a plastic electrical synapse regularizes chaos in the minimal neural circuit consisting of two chaotic bursting neurons.

  8. Fluctuations of entropy production in partially masked electric circuits

    Science.gov (United States)

    Chiang, Kuan-Hsun; Chou, Chia-Wei; Lee, Chi-Lun; Lai, Pik-Yin; Chen, Yung-Fu

    2016-02-01

    We experimentally investigate fluctuations of entropy production in a coupled driven-RC circuit. In particular, we focus on the hidden-variable problem, where part of the circuit is neglected intentionally. In the two versions of the reduced descriptions we provide for the system, the fluctuation theorem (FT) is valid in all timescales for weak coupling. However, FT fails in the strong-coupling regime, in the short-time limit for one version, and in the long-time limit for the other. In these timescales where FT fails, both descriptions still give FT-like behavior. The failure of FT implies non-Markovian dynamics, meaning there exists a hidden variable that cannot be incorporated into the heat bath. We argue that FT can be restored with the introduction of a timescale-dependent effective noise.

  9. Picosecond electrical spectroscopy using monolithic GaAs circuits

    OpenAIRE

    Konishi, Y; Kamegawa, M.; Case, M; Yu, R.; Rodwell, M. J. W.; York, R A; Rutledge, D. B.

    1992-01-01

    This article describes an experimental apparatus for free-space mm-wave transmission measurements (spectroscopy). GaAs nonlinear transmission lines and sampling circuits are used as picosecond pulse generators and detectors, with planar monolithic bowtie antennas with associated substrate lenses used as the radiating and receiving elements. The received pulse is 270 mV amplitude and 2.4 ps rise time. Through Fourier transformation of the received pulse, 30–250 GHz measurements are demonstrate...

  10. Atmospheric Breathing Electric Thruster for Planetary Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This study will investigate the development of an atmosphere-breathing electric propulsion solar-powered vehicle to explore planets such as Mars. The vehicle would...

  11. Thermodynamic optimization of an electric circuit as a non-steady energy converter

    OpenAIRE

    Valencia-Ortega, G.; Arias-Hernandez, L. A.

    2016-01-01

    Electrical circuits with transient elements can be good examples of systems where non-steady irreversible processes occur, so in the same way as a steady state energy converter, we use the formal construction of the first order irreversible thermodynamic (FOIT) to describe the energetics of these circuits. In this case, we propose an isothermic model of two meshes with transient elements and passive elements, besides it contains two voltage sources (which can be functions of time); this is a ...

  12. Stochastic Differential Equations and Markov Processes in the Modeling of Electrical Circuits

    Directory of Open Access Journals (Sweden)

    R. Rezaeyan

    2010-06-01

    Full Text Available Stochastic differential equations(SDEs, arise from physical systems that possess inherent noise and certainty. We derive a SDE for electrical circuits. In this paper, we will explore the close relationship between the SDE and autoregressive(AR model. We will solve SDE related to RC circuit with using of AR(1 model (Markov process and however with Euler-Maruyama(EM method. Then, we will compare this solutions. Numerical simulations in MATLAB are obtained.

  13. Electrically Small Resonators for Planar Metamaterial, Microwave Circuit and Antenna Design: A Comparative Analysis

    OpenAIRE

    Miguel Durán-Sindreu; Jordi Naqui; Ferran Paredes; Jordi Bonache; Ferran Martín

    2012-01-01

    Planar metamaterials and many microwave circuits and antennas are designed by means of resonators with dimensions much smaller than the wavelength at their resonance frequency. There are many types of such electrically small resonators, and the main purpose of this paper is to compare them as building blocks for the implementation of microwave components. Aspects such as resonator size, bandwidth, their circuit models when they are coupled to transmission lines (as is usually required), as we...

  14. Importance of Practical Relevance and Design Modules in Electrical Circuits Education

    OpenAIRE

    Kalpathy Sundaram; Issa Batarseh; Arthur Weeks; Ruba Akram Amarin

    2011-01-01

    The interactive technical electronic book, TechEBook, currently under development at the University of Central Florida (UCF), provides a useful tool for engineers and scientists through unique features compared to the most used traditional electrical circuit textbooks available in the market. TechEBook has comprised the two worlds of classical circuit books and an interactive operating platform such as iPads, laptops and desktops utilizing Java Virtual Machine operator. The TechEBook provides...

  15. Crisis induced intermittency in a fourth-order autonomous electric circuit

    International Nuclear Information System (INIS)

    The chaotic dynamics of a fourth-order autonomous nonlinear electric circuit has been studied. The circuit consists of two active elements, one linear negative conductance and one nonlinear resistor exhibiting a symmetrical piecewise-linear v-i characteristic and two capacitances C 1 and C 2, which serve as the control parameters of the system. Experimental time series and the corresponding phase portraits were used to register the intermittent behaviour of the corresponding dynamical system between two interacting subattractors. The distribution of the times τ, between successive transitions from the one subattractor to the other indicates that a crisis induced intermittency occurs in the studied circuit

  16. Electrical and thermal analyses for the radio-frequency circuit of ITER NBI ion source

    Energy Technology Data Exchange (ETDEWEB)

    Zamengo, A. [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti, 4, 35127 Padova (Italy)], E-mail: andrea.zamengo@igi.cnr.it; Recchia, M. [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti, 4, 35127 Padova (Italy); Department of Electrical Engineering, University of Padua, Via Gradenigo 6/A, 35131 Padova (Italy); Kraus, W. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, D-85748 Garching (Germany); Bigi, M. [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti, 4, 35127 Padova (Italy); Martens, C. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, D-85748 Garching (Germany); Toigo, V. [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti, 4, 35127 Padova (Italy)

    2009-06-15

    This paper covers specific electrical and thermal aspects of the radio-frequency (RF) circuit which supplies the ion source of the International Thermonuclear Experimental Reactor (ITER) Neutral Beam Injector (NBI). Firstly, a matching circuit for the RF Antennas is presented and a possible solution for the matching components discussed, in relation to the anticipated equivalent circuit parameters of the RF driven plasma. Secondly, the thermal behaviour of the RF transmission line is analyzed, utilising finite element tools, to evaluate the RF line overtemperature under the heaviest foreseen operating conditions.

  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. On the modeling of electrical boundary layer (electrode layer) and derivation of atmospheric electrical profiles, eddy diffusion coeffcient and scales of electrode layer

    Indian Academy of Sciences (India)

    Madhuri N Kulkarni

    2010-02-01

    Electrode layer or electrical boundary layer is one of the charge generators in the global atmospheric electric circuit. In spite of this we find very few model studies and few measurements of it in the literature. Using a new technique it is shown that in this layer, the space charge density varies exponentially in vertical. A new experimental method based on the surface measurements is discussed to determine all the characteristic scales and an average electrical and meteorological state of an electrode layer. The results obtained are in good agreement with the previous studies. So, it is suggested that an exponential space charge density profile will no longer be an assumption in the case of electrode layer studies. The profiles of atmospheric electric field and electrical conductivity are also derived and a new term named as electrode layer constant is introduced.

  19. LS1 Report: the electric atmosphere of the LHC

    CERN Multimedia

    Simon Baird

    2013-01-01

    In the LHC, testing of the main magnet (dipole and quadrupole) circuits has been completed. At the same time, the extensive tests of all the other circuits up to current levels corresponding to 7 TeV beam operation have been performed, and now the final ElQA (Electrical Quality Assurance) tests of the electrical circuits are proceeding.   In Sectors 4-5 and 5-6, where the ElQA checks have been finished, the process of removing and storing the helium has started (see the article Heatwave warning for the LHC, in this issue). This is the first step in warming up the whole machine to room temperature so that the main LS1 activities, SMACC (Super Conducting Magnet and Circuit Consolidation) and the R2E (Radiation Two Electronics) programmes, which are scheduled to start on 19 April and 22 March respectively, can get under way. As far as the LHC injectors are concerned, LINAC2 and the PS Booster are in shutdown mode, having completed their preparatory hardware test programmes, and shutdown work has alr...

  20. Electric circuit networks equivalent to chaotic quantum billiards

    OpenAIRE

    Bulgakov, Evgeny N.; Maksimov, Dmitrii N.; Sadreev, Almas F.

    2004-01-01

    We formulate two types of electric RLC resonance network equivalent to quantum billiards. In the network of inductors grounded by capacitors squared resonant frequencies are eigenvalues of the quantum billiard. In the network of capacitors grounded by inductors squared resonant frequencies are given by inverse eigen values of the billiard. In both cases local voltages play role of the wave function of the quantum billiard. However as different from quantum billiards there is a heat power beca...

  1. Electromechanical power flowcharts in systems of electrical circuits

    CERN Document Server

    de la Cruz, Jose M Diaz

    2016-01-01

    We present an original undergraduate level compilation for the physics of electromechanical systems with special consideration of power flow. An approach based on energy considerations is presented that is specially suited to compute the mechanical and electrical actions of electromagnetic fields and to draw power flowcharts that clarify the path taken by energy in typical devices. The procedure guarantees energy conservation and provides a consistent way for auditing the power flow.

  2. An atmospheric electrical method to determine the eddy diffusion coefficient

    Indian Academy of Sciences (India)

    M N Kulkarni; A K Kamra

    2010-02-01

    The ion–aerosol balance equations are solved to get the profiles of atmospheric electric parameters over the ground surface in an aerosol-rich environment under the conditions of surface radioactivity. Combining the earlier results for low aerosol concentrations and the present results for high aerosol concentrations, a relation is obtained between the average value of atmospheric electric space charge in the lowest ∼2m, the surface electric field and eddy diffusivity/aerosol concentration. The values of eddy diffusivity estimated from this method using some earlier measurements of space charge and surface electric field are in reasonably good agreement with those calculated from other standard methods using meteorological or electrical variables.

  3. The Stellar-Disk Electric (Short) Circuit: Observational Predictions for a YSO Jet Flow

    CERN Document Server

    Liffman, Kurt

    2007-01-01

    We discuss the star-disk electric circuit for a young stellar object (YSO) and calculate the expected torques on the star and the disk. We obtain the same disk magnetic field and star-disk torques as given by standard magnetohydrodynamic (MHD) analysis. We show how a short circuit in the star-disk electric circuit may produce a magnetically-driven jet flow from the inner edge of a disk surrounding a young star. An unsteady bipolar jet flow is produced that flows perpendicular to the disk plane. Jet speeds of order hundreds of kilometres per second are possible, while the outflow mass loss rate is proportional to the mass accretion rate and is a function of the disk inner radius relative to the disk co-rotation radius.

  4. New experimental method of visualizing the electric field due to surface charges on circuit elements

    Science.gov (United States)

    Jacobs, Rebecca; de Salazar, Alex; Nassar, Antonio

    2010-12-01

    Although static surface charges on circuit elements are of enormous interest, recent papers and textbooks have only discussed the problem theoretically using analytical or numerical approaches. The only well-known experimental method to visualize the structure of electric fields around circuit elements was reported by Jefimenko almost half a century ago. In our paper, we report on a simple method to visualize the electric field produced by static surface charges on current-carrying circuit elements. Our method uses a mixture of PTFE (Teflon) sealant and mineral oil, a copper wire placed in the mixture's container, and two 6 kV power supplies. We believe that our new method can be used directly in the classroom.

  5. Identifying and Investigating Difficult Concepts in Engineering Mechanics and Electric Circuits. Research Brief

    Science.gov (United States)

    Streveler, Ruth; Geist, Monica; Ammerman, Ravel; Sulzbach, Candace; Miller, Ronald; Olds, Barbara; Nelson, Mary

    2007-01-01

    This study extends ongoing work to identify difficult concepts in thermal and transport science and measure students' understanding of those concepts via a concept inventory. Two research questions provided the focal point: "What important concepts in electric circuits and engineering mechanics do students find difficult to learn?"…

  6. Wireless Electrical Device Using Open-Circuit Elements Having No Electrical Connections

    Science.gov (United States)

    Woodard, Stanley E. (Inventor); Taylor, Bryant Douglas (Inventor)

    2012-01-01

    A wireless electrical device includes an electrically unconnected electrical conductor and at least one electrically unconnected electrode spaced apart from the electrical conductor. The electrical conductor is shaped for storage of an electric field and a magnetic field. In the presence of a time-varying magnetic field, the electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses. Each electrode is at a location lying within the magnetic field response so-generated and is constructed such that a linear movement of electric charges is generated in each electrode due to the magnetic field response so-generated.

  7. Further signatures of long-term changes in atmospheric electrical parameters observed in Europe

    Directory of Open Access Journals (Sweden)

    F. Märcz

    2005-09-01

    Full Text Available Long-term decreases found recently in both the atmospheric electrical potential gradient (PG and the air-Earth current density (Jz, using observation series from the UK and Hungary, have motivated studies of other European data. Two surface data series somewhat longer than a decade were available: PG data obtained at Serra do Pilar (Portugal, and PG, Jz and positive air conductivity measurements at Athens (Greece. Selecting data to minimise local effects, the 1960–1971 Serra do Pilar PG values decrease at dawn and in the evening. Dawn data obtained at Athens (1967–1977 indicate a reduction in Jz, while the simultaneous PG values there increase (coincident air conductivity values decrease for the periods investigated. The Athens PG increase is attributed to local aerosol influences, typical of urban environments. Despite the urban influence, the Athens Jz shows similarities with soundings of the ionospheric potential. The decline in Jz at Athens occurs simultaneously with a decrease reported previously in Jz at Kew (UK, indicating that, at least, a regional decrease in the global atmospheric electrical circuit occurred during part of the twentieth century. Similar surface changes occur in European atmospheric electrical parameters, with a decrease of about 0.5% to 0.7% per year between 1920 and 1970 (possibly extending back to 1898, an annual decrease of between 2.7 and 3.4%, between 1959 and 1971 and a continued decrease of about ~1% per year between 1967 and 1984, possibly still continuing.

    Keywords. Meteorology and atmospheric dynamics (Atmospheric electricity – Geomagnetism and paleomagnetism (Time variations, secular and long term – Atmospheric composition and structure (Aerosols and particles

  8. Alignment of atmospheric mineral dust due to electric field

    OpenAIRE

    Ulanowski, Z.; Bailey, J.; P.W. Lucas; Hough, J. H.; E. Hirst

    2007-01-01

    International audience Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been due to an electric field of the order of 2 kV/m. Two alternative mechanisms for the origin of the field are examined: the effect of reduced atmospheric conductivity and ch...

  9. A simple atmospheric electrical instrument for educational use

    Directory of Open Access Journals (Sweden)

    A. J. Bennett

    2007-07-01

    Full Text Available Electricity in the atmosphere provides an ideal topic for educational outreach in environmental science. To support this objective, a simple instrument to measure real atmospheric electrical parameters has been developed and its performance evaluated. This project compliments educational activities undertaken by the Coupling of Atmospheric Layers (CAL European research collaboration. The new instrument is inexpensive to construct and simple to operate, readily allowing it to be used in schools as well as at the undergraduate University level. It is suited to students at a variety of different educational levels, as the results can be analysed with different levels of sophistication. Students can make measurements of the fair weather electric field and current density, thereby gaining an understanding of the electrical nature of the atmosphere. This work was stimulated by the centenary of the 1906 paper in which C. T. R. Wilson described a new apparatus to measure the electric field and conduction current density. Measurements using instruments based on the same principles continued regularly in the UK until 1979. The instrument proposed is based on the same physical principles as C. T. R. Wilson's 1906 instrument.

  10. A simple atmospheric electrical instrument for educational use

    Science.gov (United States)

    Bennett, A. J.; Harrison, R. G.

    2007-07-01

    Electricity in the atmosphere provides an ideal topic for educational outreach in environmental science. To support this objective, a simple instrument to measure real atmospheric electrical parameters has been developed and its performance evaluated. This project compliments educational activities undertaken by the Coupling of Atmospheric Layers (CAL) European research collaboration. The new instrument is inexpensive to construct and simple to operate, readily allowing it to be used in schools as well as at the undergraduate University level. It is suited to students at a variety of different educational levels, as the results can be analysed with different levels of sophistication. Students can make measurements of the fair weather electric field and current density, thereby gaining an understanding of the electrical nature of the atmosphere. This work was stimulated by the centenary of the 1906 paper in which C. T. R. Wilson described a new apparatus to measure the electric field and conduction current density. Measurements using instruments based on the same principles continued regularly in the UK until 1979. The instrument proposed is based on the same physical principles as C. T. R. Wilson's 1906 instrument.

  11. Background voltage distortion influence on power electric systems in the presence of the Steinmetz circuit

    Energy Technology Data Exchange (ETDEWEB)

    Sainz, Luis; Pedra, Joaquin [Department of Electrical Engineering, ETSEIB-UPC, Av. Diagonal 647, 08028 Barcelona (Spain); Caro, Manuel [IDOM Ingenieria y Arquitectura, C. Barcas 2, 46002 Valencia (Spain)

    2009-01-15

    In traction systems, it is usual to connect reactances in delta configuration with single-phase loads to reduce voltage unbalances and avoid electric system operation problems. This set is known as Steinmetz circuit. Parallel and series resonances can occur due to the capacitive reactance of the Steinmetz circuit and affect power quality. In this paper, the series resonance ''observed'' from the supply system is numerically located. The study of this resonance is important to avoid problems due to background voltage distortion. Experimental measurements are also presented to validate the obtained numerical results. (author)

  12. Importance of Practical Relevance and Design Modules in Electrical Circuits Education

    Directory of Open Access Journals (Sweden)

    Kalpathy Sundaram

    2011-05-01

    Full Text Available The interactive technical electronic book, TechEBook, currently under development at the University of Central Florida (UCF, provides a useful tool for engineers and scientists through unique features compared to the most used traditional electrical circuit textbooks available in the market. TechEBook has comprised the two worlds of classical circuit books and an interactive operating platform such as iPads, laptops and desktops utilizing Java Virtual Machine operator. The TechEBook provides an interactive applets screen that holds many modules, in which each had a specific application in the self learning process. This paper describes two of the interactive techniques in the TechEBook known as, Practical Relevance Modules (PRM and Design Modules (DM. The Practical Relevance Module will assist the readers to learn electrical circuit analysis and to understand the practical application of the electrical network theory through solving real world examples and problems. The Design Module will help students design real-life problems. These modules will be displayed after each section in the TechEBook for the user to relate his/her understanding with the outside world, which introduces the term me-applying and me-designing, as a comprehensive full experience for self or individualized education. The main emphasis of this paper is the PRM while the DM will be discussed in brief. A practical example of applying the PRM and DM features is discussed as part of a basic electrical engineering course currently given at UCF and results show improved student performances in learning materials in Electrical Circuits. In the future, such modules can be redesigned to become highly interactive with illustrated animations.

  13. Earth's Atmospheric Electricity Parameter Response During Venus Transit

    Directory of Open Access Journals (Sweden)

    Syam Sundar De

    2015-01-01

    Full Text Available Venus transited across the Sun on 06 June 2012, introducing significant contribution to the tidal characteristics of the solar atmosphere. _ atmosphere was perturbed due to an anomalous Coronal Mass Ejection (CME and γ-radiationγ-radiation influenced by the solar tide due to Venus transit, thereby the Earth-ionosphere waveguide characteristics were changed. In this anomalous situation we measured some atmospheric electricity parameters such as Schumann resonance (SR amplitude, very low frequency (VLF sferics, subionospheric transmitted signals and the point discharge current (PDC along with the vertical electrical potential gradient (PG at the ground surface on the day of transit. The results showed some remarkable variations during the transit as well as pre- and post-transit periods. The observed anomalies in the recorded data were interpreted in terms of the anomalous solar tidal effects initiated due to Venus transit.

  14. Wireless Open-Circuit In-Plane Strain and Displacement Sensor Requiring No Electrical Connections

    Science.gov (United States)

    Woodard, Stanley E. (Inventor)

    2014-01-01

    A wireless in-plane strain and displacement sensor includes an electrical conductor fixedly coupled to a substrate subject to strain conditions. The electrical conductor is shaped between its ends for storage of an electric field and a magnetic field, and remains electrically unconnected to define an unconnected open-circuit having inductance and capacitance. In the presence of a time-varying magnetic field, the electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses. The sensor also includes at least one electrically unconnected electrode having an end and a free portion extending from the end thereof. The end of each electrode is fixedly coupled to the substrate and the free portion thereof remains unencumbered and spaced apart from a portion of the electrical conductor so-shaped. More specifically, at least some of the free portion is disposed at a location lying within the magnetic field response generated by the electrical conductor. A motion guidance structure is slidingly engaged with each electrode's free portion in order to maintain each free portion parallel to the electrical conductor so-shaped.

  15. Numerical simulation for arc-plasma dynamics during contact opening process in electrical circuit-breakers

    Science.gov (United States)

    Gupta, D. N.; Patil, G. N.; Srinivas, D.; Kale, S. S.; Potnis, S. B.

    2010-02-01

    The high-energy, high-current thermal plasma that develops between electric contacts in a gas circuit-breaker during circuit interruption is an important phenomenon in the power transmission industry. The high temperature and pressure arc dissipates the tremendous amount of energy generated by the fault current. Simultaneously, this energy has to be transferred away from the contacts to build the dielectric strength level of the circuit-breaker. In order to interrupt the current, the arc must be weakened and finally extinguished. We model these phenomena by using a computer software code based on the solution of the unsteady Euler equations of gas dynamics. We consider the equations of fluid flows. These equations are solved numerically in complex circuit breaker geometries using a finite-volume method. The domain is initially filled with SF6 gas. We begin our simulations from cold mode, where the fault current is not present (hence no arc). An axis-symmetric geometry of a 145 kV gas circuit-breaker is considered to study the pressure, density, and temperature profile during contact opening process.

  16. Simulation of Higher-Order Electrical Circuits with Stochastic Parameters via SDEs

    Directory of Open Access Journals (Sweden)

    BRANCIK, L.

    2013-02-01

    Full Text Available The paper deals with a technique for the simulation of higher-order electrical circuits with parameters varying randomly. The principle consists in the utilization of the theory of stochastic differential equations (SDE, namely the vector form of the ordinary SDEs. Random changes of both excitation voltage and some parameters of passive circuit elements are considered, and circuit responses are analyzed. The voltage and/or current responses are computed and represented in the form of the sample means accompanied by their confidence intervals to provide reliable estimates. The method is applied to analyze responses of the circuit models of optional orders, specially those consisting of a cascade connection of the RLGC networks. To develop the model equations the state-variable method is used, afterwards a corresponding vector SDE is formulated and a stochastic Euler numerical method applied. To verify the results the deterministic responses are also computed by the help of the PSpice simulator or the numerical inverse Laplace transforms (NILT procedure in MATLAB, while removing random terms from the circuit model.

  17. Numerical simulation for arc-plasma dynamics during contact opening process in electrical circuit-breakers

    International Nuclear Information System (INIS)

    The high-energy, high-current thermal plasma that develops between electric contacts in a gas circuit-breaker during circuit interruption is an important phenomenon in the power transmission industry. The high temperature and pressure arc dissipates the tremendous amount of energy generated by the fault current. Simultaneously, this energy has to be transferred away from the contacts to build the dielectric strength level of the circuit-breaker. In order to interrupt the current, the arc must be weakened and finally extinguished. We model these phenomena by using a computer software code based on the solution of the unsteady Euler equations of gas dynamics. We consider the equations of fluid flows. These equations are solved numerically in complex circuit breaker geometries using a finite-volume method. The domain is initially filled with SF6 gas. We begin our simulations from cold mode, where the fault current is not present (hence no arc). An axis-symmetric geometry of a 145 kV gas circuit-breaker is considered to study the pressure, density, and temperature profile during contact opening process.

  18. Electric Circuit Model Suitable for Common Mode Current Paths Distributing in the Motor Drive System

    Science.gov (United States)

    Mutoh, Nobuyoshi; Ogata, Mitsukatsu; Harashima, Fumio

    Experimental date are used to analyze conducted EMI noises which are produced in a motor drive system with power converters comprised of a converter and an inverter. The processes are investigated in which common mode noises (voltages and currents) are strongly influenced by voltage fluctuations occurring due to switching operations. It is found that the common mode currents are resonance currents which appear in series resonance circuits distributed in the motor drive system. The circuits have various kinds of resonance frequencies related to voltage fluctuations produced by switching operations and micro-surge voltages generated at the terminal of machines such as an ac rector or a motor. Thus, parameters of the distributed series resonance circuits are estimated using the transient waveforms obtained by separating the common mode current into waves analyzed by the FFT method. It is proved through simulations and experiments that the proposed circuit models closely represent actual electric circuits for common mode current paths distributed in the motor drive system.

  19. Thermal radiation effect on the extinction properties of electric arcs in HV circuit breakers

    Directory of Open Access Journals (Sweden)

    Ziani Abderrahmane

    2009-01-01

    Full Text Available During the formation of the electric arc at the opening of a high voltage circuit breaker, the generated plasma will be the seat of a very important thermal exchange. Models founded only on conduction and convection thermal transfers don't reproduce the whole thermal exchanges that are governing the extinction process. This paper is devoted to the development of a model of the electric arc extinction in a high voltage circuit breaker taking in account the thermal radiation of the plasma, in addition to the conduction and convection phenomena. The Stefan-Boltzman equation is coupled with the heat equation, and both equations are solved simultaneously in order to follow the evolution of the arc voltage and the conductance of the thermal plasma. The obtained results are found in good agreement with experimental recordings.

  20. 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.

  1. Laser cooling and optical detection of excitations in a LC electrical circuit

    DEFF Research Database (Denmark)

    Taylor, J. M.; Sørensen, Anders Søndberg; Marcus, Charles Masamed; Polzik, Eugene Simon

    2011-01-01

    We explore a method for laser cooling and optical detection of excitations in a room temperature LC electrical circuit. Our approach uses a nanomechanical oscillator as a transducer between optical and electronic excitations. An experimentally feasible system with the oscillator capacitively coup...... coupled to the LC and at the same time interacting with light via an optomechanical force is shown to provide strong electromechanical coupling. Conditions for improved sensitivity and quantum limited readout of electrical signals with such an “optical loud speaker” are outlined....

  2. A strategy for adaptive synchronization of an electrical chaotic circuit based on nonlinear control

    International Nuclear Information System (INIS)

    This paper deals with the adaptive synchronization of an electrical chaotic oscillator through a nonlinear control law. The nonlinear controller is designed to synchronize two identical chaotic systems. Lyapunov stability theory is applied to prove that under some conditions the drive-response system can achieve practical synchronization. The designed controller contains only continuous nonlinear terms existing in the dynamical systems and is easy to implement in practice. As an illustrative example to verify the validity of the proposed method, a hyperbolic tangent-based electrical and chaotic circuit is chosen and its dynamics is briefly investigated to demonstrate its chaotic behavior.

  3. Development and Implementation of an Electric Circuits On-Line Course

    Directory of Open Access Journals (Sweden)

    Ahmed Hussain

    2009-02-01

    Full Text Available An electric circuit on-line course has been developed at KFUPM to support student centered learning. The course has been used in the first stage to supplement the class room face-to-face instruction. This paper describes the development stages of the on-line course and highlights its fundamental features that are not available in the traditional methods of instruction. The paper also includes the results of a survey conducted among students who have utilized the on-line material to supplement their traditional study of the electric circuits’ course. The results of the survey showed a general satisfaction with the course content and the instructional effectiveness.

  4. Detection and location of electrical insulation faults on the LHC superconducting circuits during hardware commissioning

    CERN Document Server

    Bozzini, D; Mess, K H; Russenschuck, Stephan

    2008-01-01

    As part of the electrical quality assurance program (ELQA), the insulation of all superconducting circuits of the LHC has to be tested with a d.c. voltage of up to 1.9 kV. Fault location within a ± 3 m range over the total length of 2700 m has been achieved in order to limit the number of interconnection openings for repair. In this paper, the methods, tooling, and procedures for the detection and location of electrical faults will be presented in view of the practical experience gained in the LHC tunnel. Three particular cases of localized faults during LHC hardware commissioning will be discussed.

  5. Parameterization of electrical equivalent circuits for pem fuel cells; Parametrierung elektrischer Aequivalentschaltbilder von PEM Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Haubrock, J.

    2007-12-13

    Fuel cells are a very promising technology for energy conversion. For optimization purpose, useful simulation tools are needs. Simulation tools should simulate the static and dynamic electrical behaviour and the models should parameterized by measurment results which should be done easily. In this dissertation, a useful model for simulating a pem fuel cell is developed. the model should parametrizes by V-I curve measurment and by current step respond. The model based on electrical equivalent circuits and it is shown, that it is possible to simulate the dynamic behaviour of a pem fuel cell stack. The simulation results are compared by measurment results. (orig.)

  6. 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.

  7. Full wave analysis of non-radiative dielectric waveguide modulator for the determination of electrical equivalent circuit

    Indian Academy of Sciences (India)

    N P Pathak; A Basu; S K Koul

    2008-07-01

    This paper reports the determination of electrical equivalent circuit of ON/OFF modulator in non-radiative dielectric (NRD) guide configurations at Ka-band. Schottky barrier mixer diode is used to realize this modulator and its characteristics are determined experimentally using vector network analyzer. Full wave FEM simulator HFSS is used to determine an equivalent circuit for the mounted diode and modulator in ON and OFF states. This equivalent circuit is used to qualitatively explain the experimental characteristics of modulator.

  8. IE Information No. 87-12: Potential problems with metal clad circuit breakers, General Electric type AKF-2-25

    International Nuclear Information System (INIS)

    This notice is to alert recipients of potential problems with the General Electric Company (GE) AKF-2-25 type circuit breakers failing to fully open on demand. The GE AKF type circuit breakers have been shown to be susceptible to failure as a result of binding within the breaker cam mechanism, unless proper maintenance procedures are developed and followed by individuals trained specifically to service the AKF breaker. Maintenance information is given that should be incorporated into programs for these circuit breakers

  9. Investigation on critical breakdown electric field of hot carbon dioxide for gas circuit breaker applications

    Science.gov (United States)

    Sun, Hao; Rong, Mingzhe; Wu, Yi; Chen, Zhexin; Yang, Fei; Murphy, Anthony B.; Zhang, Hantian

    2015-02-01

    Sulfur hexafluoride (SF6) gas is widely used in high-voltage circuit breakers, but due to its high global warming potential, substitutes are being sought. CO2 has been investigated as a candidate based on its arc interruption performance. The hot gas in the circuit breaker after current zero, with a complicated species composition caused by the dissociation and many other reactions, will lead to the electrical breakdown, which is one of the major concerns in assessing the arc interruption performance. Despite this, little research has been reported on the dielectric strength of hot CO2. In this paper, the dielectric properties of hot CO2 related to the dielectric recovery phase of the circuit breaker were investigated in the temperature range from 300 to 4000 K and in the pressure range from 0.01 to 1.0 MPa. Under the assumptions of local thermodynamic equilibrium (LTE) and local chemical equilibrium (LCE), the equilibrium compositions of hot CO2 were obtained based on Gibbs free energy minimization. The cross sections for interactions between electrons and the species are presented. The critical reduced electric field strength of CO2 was determined by balancing electron generation and loss. These were evaluated using the electron energy distribution function (EEDF) derived from the two-term Boltzmann transport equation. The result indicates that unlike SF6 or air, in hot CO2 the reduced critical electric field strength does not change monotonically with increasing heavy-particle temperature from 300 to 4000 K. CO2 has a superior dielectric strength to pure SF6 above 2500 K at 0.5 MPa, which means it has the potential to improve the interruption performance of the circuit breakers, while reducing the global warming effect. Good agreement was found with published experimental results and calculations for CO2 at room temperature, and with previous calculations for hot CO2.

  10. Investigation on critical breakdown electric field of hot carbon dioxide for gas circuit breaker applications

    International Nuclear Information System (INIS)

    Sulfur hexafluoride (SF6) gas is widely used in high-voltage circuit breakers, but due to its high global warming potential, substitutes are being sought. CO2 has been investigated as a candidate based on its arc interruption performance. The hot gas in the circuit breaker after current zero, with a complicated species composition caused by the dissociation and many other reactions, will lead to the electrical breakdown, which is one of the major concerns in assessing the arc interruption performance. Despite this, little research has been reported on the dielectric strength of hot CO2. In this paper, the dielectric properties of hot CO2 related to the dielectric recovery phase of the circuit breaker were investigated in the temperature range from 300 to 4000 K and in the pressure range from 0.01 to 1.0 MPa. Under the assumptions of local thermodynamic equilibrium (LTE) and local chemical equilibrium (LCE), the equilibrium compositions of hot CO2 were obtained based on Gibbs free energy minimization. The cross sections for interactions between electrons and the species are presented. The critical reduced electric field strength of CO2 was determined by balancing electron generation and loss. These were evaluated using the electron energy distribution function (EEDF) derived from the two-term Boltzmann transport equation. The result indicates that unlike SF6 or air, in hot CO2 the reduced critical electric field strength does not change monotonically with increasing heavy-particle temperature from 300 to 4000 K. CO2 has a superior dielectric strength to pure SF6 above 2500 K at 0.5 MPa, which means it has the potential to improve the interruption performance of the circuit breakers, while reducing the global warming effect. Good agreement was found with published experimental results and calculations for CO2 at room temperature, and with previous calculations for hot CO2. (paper)

  11. Alignment of atmospheric mineral dust due to electric field

    Science.gov (United States)

    Ulanowski, Z.; Bailey, J.; Lucas, P. W.; Hough, J. H.; Hirst, E.

    2007-12-01

    Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been due to an electric field of the order of 2 kV/m. Two alternative mechanisms for the origin of the field are examined: the effect of reduced atmospheric conductivity and charging of the dust layer, the latter effect being a more likely candidate. It is concluded that partial alignment may be a common feature of Saharan dust layers. The modelling indicates that the alignment can significantly alter dust optical depth. This "Venetian blind effect" may have decreased optical thickness in the vertical direction by as much as 10% for the case reported here. It is also possible that the alignment and the electric field modify dust transport.

  12. Alignment of atmospheric mineral dust due to electric field

    Directory of Open Access Journals (Sweden)

    Z. Ulanowski

    2007-12-01

    Full Text Available Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been due to an electric field of the order of 2 kV/m. Two alternative mechanisms for the origin of the field are examined: the effect of reduced atmospheric conductivity and charging of the dust layer, the latter effect being a more likely candidate. It is concluded that partial alignment may be a common feature of Saharan dust layers. The modelling indicates that the alignment can significantly alter dust optical depth. This "Venetian blind effect" may have decreased optical thickness in the vertical direction by as much as 10% for the case reported here. It is also possible that the alignment and the electric field modify dust transport.

  13. A joint dataset of fair-weather atmospheric electricity

    Science.gov (United States)

    Tammet, H.

    2009-02-01

    A new open access dataset ATMEL2007A ( http://ael.physic.ut.ee/tammet/dd/) takes advantage of the diary-type data structure. The dataset comprises the measurements of atmospheric electric field, positive and negative conductivities, air ion concentrations and accompanying meteorological measurements at 13 stations, including 7 stations of the former World Data Centre network. The dataset incorporates more than half a million diurnal series of hourly averages and it can easily be expanded with additional data. The dataset is designed for importing into a personal computer, which makes possible the appending of private data and safely protecting it from public access. Available free software allows extracting data excerpts in the form of traditional data tables or spreadsheets. Examples show how the dataset can be used in the research of the correlations and trends in atmospheric electricity and air pollution.

  14. Fairweather atmospheric electricity at Antarctica during local summer as observed from Indian station, Maitri

    Indian Academy of Sciences (India)

    C Panneerselvam; C Selvaraj; K Jeeva; K U Nair; C P Anilkumar; S Gurubaran

    2007-06-01

    Surface measurements of the atmospheric electrical parameters like Maxwell current, electric field and conductivity studied at the Indian station, Maitri (70.75°S, 11.75°E, 117m above mean sea level), Antarctica, during austral summer have been analyzed for the years 2001 to 2004. A total of 69 days were selected which satisfied the ‘fairweather’ conditions, i.e., days with absence of high winds, drifting or falling snow, clouds, and fog effects. The diurnal variation curve of electric field and vertical current averaged for 69 fairweather days is a single periodic with a minimum at 03:00UT and a maximum near 19:00UT, which is very similar to the Carnegie curve. The correlation coefficient between these measured parameters has a high value (more than 0.9) for all the days. During fairweather days the measured current and field variations are similar and hence it is clear that the conductivity is more or less stable. During magnetically disturbed days, the dawn-dusk potential drop has clear influences on the diurnal variation and it modifies the conductivity. Apart from the day-to-day variation in low latitude thunderstorm activity, there are diurnal, seasonal, inter-annual variations in the electric potential and the currents, as well as solar influences on the measured parameters. This study will help us to examine the impact of solar and geophysical phenomena like solar flares, geomagnetic storms and substorms on the global electric circuit.

  15. Electrical, Optical and acoustic diagnostics of atmospheric pressure gas discharges

    OpenAIRE

    O'Connor, Niall

    2011-01-01

    This thesis presents original diagnostic investigations of atmospheric pressure gaseous discharges, operating in owing helium and helium with low concentrations (0.1 - 1 %) of gas admixtures, together with novel biomedical surface functionalisations. The initial body of this work focuses on comprehensive electrical and optical diagnostics of the operation of an industrial scale dielectric barrier discharge (DBD), maintained in a 10 l/min w of both helium and helium with 1% admixed ...

  16. Effect of atmospheric electricity on dry deposition of airborne particles from atmosphere

    Science.gov (United States)

    Tammet, H.; Kimmel, V.; Israelsson, S.

    The electric mechanism of dry deposition is well known in the case of unattached radon daughter clusters that are unipolar charged and of high mobility. The problematic role of the electric forces in deposition of aerosol particles is theoretically examined by comparing the fluxes of particles carried by different deposition mechanisms in a model situation. The electric mechanism of deposition appears essential for particles of diameter 10-200 nm in conditions of low wind speed. The electric flux of fine particles can be dominant on the tips of leaves and needles even in a moderate atmospheric electric field of a few hundred V m -1 measured over the plane ground surface. The electric deposition is enhanced under thunderclouds and high voltage power lines. Strong wind suppresses the relative role of the electric deposition when compared with aerodynamic deposition. When compared with diffusion deposition the electric deposition appears less uniform: the precipitation particulate matter on the tips of leaves and especially on needles of top branches of conifer trees is much more intensive than on the ground surface and electrically shielded surfaces of plants. The knowledge of deposition geometry could improve our understanding of air pollution damage to plants.

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

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, M. S.; Gusev, Yu. P., E-mail: GusevYP@mpei.ru; Monakov, Yu. V.; Cho, Gvan Chun [National Research University “Moscow Power Engineering Institute,” (Russian Federation)

    2016-01-15

    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.

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

    International Nuclear Information System (INIS)

    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

  19. On-chip detection circuit for protection design in display panel against electrical fast transient (EFT) disturbance

    International Nuclear Information System (INIS)

    A new on-chip detection circuit is proposed for electrical fast transient (EFT) protection design in a display system. For microelectronic products, electrical transient disturbances often cause upset or frozen states under the IEC test standard. The output signal of the proposed detection circuit can be used as a firmware index to execute system automatic recovery operations and to release the EFT-induced locked states in display panels. The circuit function to detect positive or negative electrical transients has been investigated in HSPICE simulation and verified in silicon chip. The experimental results have confirmed successful circuit performance under EFT tests. With hardware/firmware co-design, the immunity of a display system against electrical transient disturbance has been significantly improved.

  20. Identification of a Retinal Circuit for Recurrent Suppression Using Indirect Electrical Imaging.

    Science.gov (United States)

    Greschner, Martin; Heitman, Alexander K; Field, Greg D; Li, Peter H; Ahn, Daniel; Sher, Alexander; Litke, Alan M; Chichilnisky, E J

    2016-08-01

    Understanding the function of modulatory interneuron networks is a major challenge, because such networks typically operate over long spatial scales and involve many neurons of different types. Here, we use an indirect electrical imaging method to reveal the function of a spatially extended, recurrent retinal circuit composed of two cell types. This recurrent circuit produces peripheral response suppression of early visual signals in the primate magnocellular visual pathway. We identify a type of polyaxonal amacrine cell physiologically via its distinctive electrical signature, revealed by electrical coupling with ON parasol retinal ganglion cells recorded using a large-scale multi-electrode array. Coupling causes the amacrine cells to fire spikes that propagate radially over long distances, producing GABA-ergic inhibition of other ON parasol cells recorded near the amacrine cell axonal projections. We propose and test a model for the function of this amacrine cell type, in which the extra-classical receptive field of ON parasol cells is formed by reciprocal inhibition from other ON parasol cells in the periphery, via the electrically coupled amacrine cell network. PMID:27397894

  1. Electrically detected magnetic resonance modeling and fitting: An equivalent circuit approach

    International Nuclear Information System (INIS)

    The physics of electrically detected magnetic resonance (EDMR) quadrature spectra is investigated. An equivalent circuit model is proposed in order to retrieve crucial information in a variety of different situations. This model allows the discrimination and determination of spectroscopic parameters associated to distinct resonant spin lines responsible for the total signal. The model considers not just the electrical response of the sample but also features of the measuring circuit and their influence on the resulting spectral lines. As a consequence, from our model, it is possible to separate different regimes, which depend basically on the modulation frequency and the RC constant of the circuit. In what is called the high frequency regime, it is shown that the sign of the signal can be determined. Recent EDMR spectra from Alq3 based organic light emitting diodes, as well as from a-Si:H reported in the literature, were successfully fitted by the model. Accurate values of g-factor and linewidth of the resonant lines were obtained

  2. The impact of the conceptual change model on grade 10 learners using simple electric circuits / Mmaletsegetla Paulus Manabile

    OpenAIRE

    Manabile, Mmaletsegetla Paulus

    2014-01-01

    Poor academic performance in science is a problem in the world. Numbers of factors contribute to this academic performance. Secondary school learners, particularly those in grade 10 are experiencing problems in understanding simple electric circuits in Physical Sciences. Lack of exposure to practical work might be one of the factors that contribute to lack of understanding of simple electric circuit and inability to link what they learn in class with the outside world. For that reason, it ...

  3. Global Electric Circuit Implications of Total Current Measurements over Electrified Clouds

    Science.gov (United States)

    Mach, Douglas M.; Blakeslee, Richard J.; Bateman, Monte G.

    2009-01-01

    We determined total conduction (Wilson) currents and flash rates for 850 overflights of electrified clouds spanning regions including the Southeastern United States, the Western Atlantic Ocean, the Gulf of Mexico, Central America and adjacent oceans, Central Brazil, and the South Pacific. The overflights include storms over land and ocean, with and without lightning, and with positive and negative Wilson currents. We combined these individual storm overflight statistics with global diurnal lightning variation data from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) to estimate the thunderstorm and electrified shower cloud contributions to the diurnal variation in the global electric circuit. The contributions to the global electric circuit from lightning producing clouds are estimated by taking the mean current per flash derived from the overflight data for land and ocean overflights and combining it with the global lightning rates (for land and ocean) and their diurnal variation derived from the LIS/OTD data. We estimate the contribution of non-lightning producing electrified clouds by assuming several different diurnal variations and total non-electrified storm counts to produce estimates of the total storm currents (lightning and non-lightning producing storms). The storm counts and diurnal variations are constrained so that the resultant total current diurnal variation equals the diurnal variation in the fair weather electric field (+/-15%). These assumptions, combined with the airborne and satellite data, suggest that the total mean current in the global electric circuit ranges from 2.0 to 2.7 kA, which is greater than estimates made by others using other methods.

  4. Effects of extraordinary solar cosmic ray events on variations in the atmospheric electric field at high latitudes

    Science.gov (United States)

    Shumilov, O. I.; Kasatkina, E. A.; Frank-Kamenetsky, A. V.

    2015-09-01

    Studies of variations in the atmospheric electric field vertical component ( E z ) are illustrated based on data from the Apatity high-latitude observatory (geomagnetic latitude Φ' = 63.8°) for three solar cosmic ray (SCR) events that occurred on April 15, April 18, and November 4, 2001. For the SCR event of April 15, 2001, the observed E z variations have been compared with the corresponding data from the Voeykovo midlatitude observatory and the Vostok observatory on the polar cap. It has been indicated that solar coronal mass ejections and some powerful SCR events can result in variations in the global electric circuit. Disturbances in the atmospheric electric field can be used to diagnose the development of intense processes on the Sun.

  5. Global Electric Circuit Implications of Combined Aircraft Storm Electric Current Measurements and Satellite-Based Diurnal Lightning Statistics

    Science.gov (United States)

    Mach, Douglas M.; Blakeslee, Richard J.; Bateman, Monte G.

    2011-01-01

    Using rotating vane electric field mills and Gerdien capacitors, we measured the electric field profile and conductivity during 850 overflights of thunderstorms and electrified shower clouds (ESCs) spanning regions including the Southeastern United States, the Western Atlantic Ocean, the Gulf of Mexico, Central America and adjacent oceans, Central Brazil, and the South Pacific. The overflights include storms over land and ocean, and with positive and negative fields above the storms. Over three-quarters (78%) of the land storms had detectable lightning, while less than half (43%) of the oceanic storms had lightning. Integrating our electric field and conductivity data, we determined total conduction currents and flash rates for each overpass. With knowledge of the storm location (land or ocean) and type (with or without lightning), we determine the mean currents by location and type. The mean current for ocean thunderstorms is 1.7 A while the mean current for land thunderstorms is 1.0 A. The mean current for ocean ESCs 0.41 A and the mean current for land ESCs is 0.13 A. We did not find any significant regional or latitudinal based patterns in our total conduction currents. By combining the aircraft derived storm currents and flash rates with diurnal flash rate statistics derived from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) low Earth orbiting satellites, we reproduce the diurnal variation in the global electric circuit (i.e., the Carnegie curve) to within 4% for all but two short periods of time. The agreement with the Carnegie curve was obtained without any tuning or adjustment of the satellite or aircraft data. Given our data and assumptions, mean contributions to the global electric circuit are 1.1 kA (land) and 0.7 kA (ocean) from thunderstorms, and 0.22 kA (ocean) and 0.04 (land) from ESCs, resulting in a mean total conduction current estimate for the global electric circuit of 2.0 kA. Mean storm counts are 1100 for land

  6. Monte Carlo simulations of air showers in atmospheric electric fields

    CERN Document Server

    Buitink, S; Falcke, H; Heck, D; Kuijpers, J

    2009-01-01

    The development of cosmic ray air showers can be influenced by atmospheric electric fields. Under fair weather conditions these fields are small, but the strong fields inside thunderstorms can have a significant effect on the electromagnetic component of a shower. Understanding this effect is particularly important for radio detection of air showers, since the radio emission is produced by the shower electrons and positrons. We perform Monte Carlo simulations to calculate the effects of different electric field configurations on the shower development. We find that the electric field becomes important for values of the order of 1 kV/cm. Not only can the energy distribution of electrons and positrons change significantly for such field strengths, it is also possible that runaway electron breakdown occurs at high altitudes, which is an important effect in lightning initiation.

  7. Reconfigurable anisotropy and functional transformations with VO$_{2}$-based metamaterial electric circuits

    CERN Document Server

    Savo, Salvatore; Castaldi, Giuseppe; Moccia, Massimo; Galdi, Vincenzo; Ramanathan, Shriram; Sato, Yuki

    2014-01-01

    We demonstrate an innovative multifunctional artificial material that combines exotic metamaterial properties and the environmentally responsive nature of phase change media. The tunable metamaterial is designed with the aid of two interwoven coordinate-transformation equations and implemented with a network of thin film resistors and vanadium dioxide ($VO_{2}$). The strong temperature dependence of $VO_{2}$ electrical conductivity results in a relevant modification of the resistor network behavior, and we provide experimental evidence for a reconfigurable metamaterial electric circuit (MMEC) that not only mimics a continuous medium but is also capable of responding to thermal stimulation through dynamic variation of its spatial anisotropy. Upon external temperature change the overall effective functionality of the material switches between a "truncated-cloak" and "concentrator" for electric currents. Possible applications may include adaptive matching resistor networks, multifunctional electronic devices, an...

  8. Study of switching electric circuits with DC hybrid breaker, one stage

    Science.gov (United States)

    Niculescu, T.; Marcu, M.; Popescu, F. G.

    2016-06-01

    The paper presents a method of extinguishing the electric arc that occurs between the contacts of direct current breakers. The method consists of using an LC type extinguishing group to be optimally sized. From this point of view is presented a theoretical approach to the phenomena that occurs immediately after disconnecting the load and the specific diagrams are drawn. Using these, the elements extinguishing group we can choose. At the second part of the paper there is presented an analyses of the circuit switching process by decomposing the process in particular time sequences. For every time interval there was conceived a numerical simulation model in MATLAB-SIMULINK medium which integrates the characteristic differential equation and plots the capacitor voltage variation diagram and the circuit dumping current diagram.

  9. Estimation of Operating Condition of Appliances Using Circuit Current Data on Electric Distribution Boards

    Science.gov (United States)

    Iwafune, Yumiko; Ogimoto, Kazuhiko; Yagita, Yoshie

    The Energy management systems (EMS) on demand sides are expected as a method to enhance the capability of supply and demand balancing of a power system under the anticipated penetration of renewable energy generation such as Photovoltaics (PV). Elucidation of energy consumption structure in a building is one of important elements for realization of EMS and contributes to the extraction of potential energy saving. In this paper, we propose the estimation method of operating condition of household appliances using circuit current data on an electric distribution board. Circuit current data are broken down by their shape using a self-organization map method and aggregated by appliance based on customers' information of appliance possessed. Proposed method is verified using residential energy consumption measurement survey data.

  10. On the symmetry of electric fields exerting on interdigitated structures: Qucs equivalent circuit model and experiment

    International Nuclear Information System (INIS)

    The symmetry of the electric field in a dielectric medium sandwiched between comb-fingers dominates the stability of the comb-drive actuator. The stability can be spontaneously broken by the asymmetry appearing on the two sides of the finger array. A quite universal circuit simulator (Qucs) equivalent circuit model was built to illustrate that the symmetry is not preserved in the outer four comb-fingers, especially the first and last fingers, because they are subjected to unbalanced electrostatic forces. Experiments were conducted to verify the proposed Qucs model, which also demonstrated that symmetry exists everywhere in an imaginary comb-finger array with infinite interdigitaed fingers. In this work, the ideal comb-finger array can be nearly realized by making the two outermost fingers five times wider than the others; as a result, the symmetry is preserved and the instability is effectively suppressed in the comb-finger array.

  11. Integrated bistable generator for wideband energy harvesting with optimized synchronous electric charge extraction circuit

    International Nuclear Information System (INIS)

    Bistable generators have been proposed as potential solutions to the challenge of variable vibration frequencies. In the authors' previous works, a specific BSM (Buckled-Spring-Mass) harvester architecture has been suggested. It presents some properties of interests: simplicity, compactness and wide bandwidth. Using a normalized model of the BSM generator for design and optimization at different scales, this paper presents a new integrated BSM bistable generator design with the OSECE (Optimized Synchronous Electric Charge Extraction) technique which is used for broadband energy harvesting. The experimental results obtained from an initial prototype device show that the BSM generator with the OSECE circuit exhibits better performance for low coupling cases or reverse sweep excitations. This is also confirmed by simulations for the proposed integrated generator. Good applications prospective is expected for the bistable generator with the nonlinear OSECE circuit

  12. An Equivalent Electrical Circuit Model of Proton Exchange Membrane Fuel Cells Based on Mathematical Modelling

    Directory of Open Access Journals (Sweden)

    Dinh An Nguyen

    2012-07-01

    Full Text Available Many of the Proton Exchange Membrane Fuel Cell (PEMFC models proposed in the literature consist of mathematical equations. However, they are not adequately practical for simulating power systems. The proposed model takes into account phenomena such as activation polarization, ohmic polarization, double layer capacitance and mass transport effects present in a PEM fuel cell. Using electrical analogies and a mathematical modeling of PEMFC, the circuit model is established. To evaluate the effectiveness of the circuit model, its static and dynamic performances under load step changes are simulated and compared to the numerical results obtained by solving the mathematical model. Finally, the applicability of our model is demonstrated by simulating a practical system.

  13. Factors influencing the renal arterial Doppler waveform: a simulation study using an electrical circuit model (secondary publication

    Directory of Open Access Journals (Sweden)

    Chang Kyu Sung

    2016-01-01

    Full Text Available Purpose: The goal of this study was to evaluate the effect of vascular compliance, resistance, and pulse rate on the resistive index (RI by using an electrical circuit model to simulate renal blood flow. Methods: In order to analyze the renal arterial Doppler waveform, we modeled the renal blood-flow circuit with an equivalent simple electrical circuit containing resistance, inductance, and capacitance. The relationships among the impedance, resistance, and compliance of the circuit were derived from well-known equations, including Kirchhoff’s current law for alternating current circuits. Simulated velocity-time profiles for pulsatile flow were generated using Mathematica (Wolfram Research and the influence of resistance, compliance, and pulse rate on waveforms and the RI was evaluated. Results: Resistance and compliance were found to alter the waveforms independently. The impedance of the circuit increased with increasing proximal compliance, proximal resistance, and distal resistance. The impedance decreased with increasing distal compliance. The RI of the circuit decreased with increasing proximal compliance and resistance. The RI increased with increasing distal compliance and resistance. No positive correlation between impedance and the RI was found. Pulse rate was found to be an extrinsic factor that also influenced the RI. Conclusion: This simulation study using an electrical circuit model led to a better understanding of the renal arterial Doppler waveform and the RI, which may be useful for interpreting Doppler findings in various clinical settings.

  14. Factors influencing the renal arterial Doppler waveform: a simulation study using an electrical circuit model (secondary publication)

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Chang Kyu [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Han, Bong Soo [Dept. of Radiological Science, College of Health Science, Yonsei University, Wonju (Korea, Republic of); Kim, Seung Hyup [Dept. of Radiology, Institute of Radiation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2016-01-15

    The goal of this study was to evaluate the effect of vascular compliance, resistance, and pulse rate on the resistive index (RI) by using an electrical circuit model to simulate renal blood flow. In order to analyze the renal arterial Doppler waveform, we modeled the renal blood-flow circuit with an equivalent simple electrical circuit containing resistance, inductance, and capacitance. The relationships among the impedance, resistance, and compliance of the circuit were derived from well-known equations, including Kirchhoff’s current law for alternating current circuits. Simulated velocity-time profiles for pulsatile flow were generated using Mathematica (Wolfram Research) and the influence of resistance, compliance, and pulse rate on waveforms and the RI was evaluated. Resistance and compliance were found to alter the waveforms independently. The impedance of the circuit increased with increasing proximal compliance, proximal resistance, and distal resistance. The impedance decreased with increasing distal compliance. The RI of the circuit decreased with increasing proximal compliance and resistance. The RI increased with increasing distal compliance and resistance. No positive correlation between impedance and the RI was found. Pulse rate was found to be an extrinsic factor that also influenced the RI. This simulation study using an electrical circuit model led to a better understanding of the renal arterial Doppler waveform and the RI, which may be useful for interpreting Doppler findings in various clinical settings.

  15. An Overview of Peach, the Atmospheric Electricity Component of Hymex

    Science.gov (United States)

    Defer, E.; Coquillat, S.; Pinty, J.; Soula, S.; Martin, J.; Prieur, S.; Richard, E.; Rison, W.; Krehbiel, P. R.; Rodeheffer, D.; Ducrocq, V.; Bousquet, O.; Labatut, L.; Roussot, O.; Farges, T.; Vergeiner, C.; Schulz, W.; Anderson, G.; Pedeboy, S.; Betz, H.; Lagouvardos, K.; Ortega, P.; Molinié, G.; Blanchet, P.

    2012-12-01

    The PEACH (Projet en Electricité Atmosphérique pour la Campagne HyMeX) project is the Atmospheric Electricity component of the HyMeX (Hydrology cycle in the Mediterranean Experiment) experiment aimed at measuring and analyzing the lightning activity and electrical state of thunderstorms over the Mediterranean Sea. During the SOP1 (Special Observation Period; September-October 2012), records of four European operational lightning detection networks (ATDNET, UKMO; EUCLID; LINET, nowcast; ZEUS, NOA) and the NMT Lightning Mapping Array (LMA) were used to locate and characterize the lightning activity over South-Eastern France. Other research instruments such as induction rings (LA), electric field measurements (OVE; LA; NMT), video camera (OVE; ONERA), microbarometer and microphone arrays (CEA) were deployed to document the properties of the lightning flashes as well as the electrical state of parent thunderclouds. All these observations are used to document the evolution of the electrical activity during the life cycle of SOP storms in conjunction with microphysics and kinematics description of the parent storms as derived mainly from ground-based radar and airborne in situ observations. Interpretation of the results are performed with the use of cloud models (MM5; MESO-NH with its electrification and lightning schemes). We will present an overview of the PEACH project. We will discuss some of the recorded cases. We will also introduce some of the products that will be made available to the HyMeX Community.

  16. An ultracapacitor circuit for reducing sulfation in lead acid batteries for Mild Hybrid Electric Vehicles

    International Nuclear Information System (INIS)

    The nickel metal hydride (NiMH) batteries used in most hybrid electric vehicles (HEVs) provide satisfactory performance, but are quite expensive. In spite of their lower energy density, lead acid batteries would be much more economical except they are prone to sulfation in HEV applications. However, sulfation can be greatly reduced by a circuit that uses an ultracapacitor in conjunction with the battery. The resulting system will provide much cheaper energy storage if ultracapacitor prices can be reduced to levels predicted by some manufacturers. (author)

  17. Development and Implementation of an Electric Circuits On-Line Course

    OpenAIRE

    Ahmed Hussain; Umar Johar; Noman Tassaduq; Hussain Al-Jamid; Mahmoud M. Dawoud

    2009-01-01

    An electric circuit on-line course has been developed at KFUPM to support student centered learning. The course has been used in the first stage to supplement the class room face-to-face instruction. This paper describes the development stages of the on-line course and highlights its fundamental features that are not available in the traditional methods of instruction. The paper also includes the results of a survey conducted among students who have utilized the on-line material to supplement...

  18. Alignment of atmospheric mineral dust due to electric field

    Directory of Open Access Journals (Sweden)

    Z. Ulanowski

    2007-09-01

    Full Text Available Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction consistent with the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been due to an electric field of the order of 2 kV/m. Two alternative mechanisms for the origin of the field are examined: the effect of reduced atmospheric conductivity and charging of the dust layer, the latter effect being a more likely candidate. It is concluded that partial alignment may be a common feature of Saharan dust layers. The modelling also indicates that the alignment can significantly alter dust optical depth. This "Venetian blind effect" may have decreased optical thickness in the vertical direction by as much as 10% for the case reported here.

  19. NRC Information No. 90-41: Potential failure of General Electric Magne-Blast circuit breakers and AK circuit breakers

    International Nuclear Information System (INIS)

    This information notice is intended to alert addressees to potential safety concerns that may result from failures of GE vertical lift (AM) and horizontal draw-out (AMH) Magne-Blast circuit breakers utilizing ML-13 operating mechanisms to open or close them and AK circuit breakers. The particular breaker failures reported herein were caused by operating problems with prop springs, snap rings and lubricating grease. GE Nuclear Energy has informed the NRC that it is aware of these problems and that GE routinely checks and corrects them if the circuit breakers are serviced at one of the four GE nuclear service centers in the US. However, the NRC is aware that some utilities may have their circuit breakers repaired or serviced at facilities other than the four GE nuclear service centers

  20. Simple voltage-controlled current source for wideband electrical bioimpedance spectroscopy: circuit dependences and limitations

    International Nuclear Information System (INIS)

    In this work, the single Op-Amp with load-in-the-loop topology as a current source is revisited. This circuit topology was already used as a voltage-controlled current source (VCCS) in the 1960s but was left unused when the requirements for higher frequency arose among the applications of electrical bioimpedance (EBI). The aim of the authors is not only limited to show that with the currently available electronic devices it is perfectly viable to use this simple VCCS topology as a working current source for wideband spectroscopy applications of EBI, but also to identify the limitations and the role of each of the circuit components in the most important parameter of a current for wideband applications: the output impedance. The study includes the eventual presence of a stray capacitance and also an original enhancement, driving with current the VCCS. Based on the theoretical analysis and experimental measurements, an accurate model of the output impedance is provided, explaining the role of the main constitutive elements of the circuit in the source's output impedance. Using the topologies presented in this work and the proposed model, any electronic designer can easily implement a simple and efficient current source for wideband EBI spectroscopy applications, e.g. in this study, values above 150 kΩ at 1 MHz have been obtained, which to the knowledge of the authors are the largest values experimentally measured and reported for a current source in EBI at this frequency

  1. Simple voltage-controlled current source for wideband electrical bioimpedance spectroscopy: circuit dependences and limitations

    Science.gov (United States)

    Seoane, F.; Macías, R.; Bragós, R.; Lindecrantz, K.

    2011-11-01

    In this work, the single Op-Amp with load-in-the-loop topology as a current source is revisited. This circuit topology was already used as a voltage-controlled current source (VCCS) in the 1960s but was left unused when the requirements for higher frequency arose among the applications of electrical bioimpedance (EBI). The aim of the authors is not only limited to show that with the currently available electronic devices it is perfectly viable to use this simple VCCS topology as a working current source for wideband spectroscopy applications of EBI, but also to identify the limitations and the role of each of the circuit components in the most important parameter of a current for wideband applications: the output impedance. The study includes the eventual presence of a stray capacitance and also an original enhancement, driving with current the VCCS. Based on the theoretical analysis and experimental measurements, an accurate model of the output impedance is provided, explaining the role of the main constitutive elements of the circuit in the source's output impedance. Using the topologies presented in this work and the proposed model, any electronic designer can easily implement a simple and efficient current source for wideband EBI spectroscopy applications, e.g. in this study, values above 150 kΩ at 1 MHz have been obtained, which to the knowledge of the authors are the largest values experimentally measured and reported for a current source in EBI at this frequency.

  2. Electrical Circuit Modeling Considering a Transient Space Charge for Nonsteady Poisson-Nernst-Planck Equations

    Science.gov (United States)

    Sugioka, Hideyuki

    2015-10-01

    Transient space charge phenomena at high step voltages are interesting since they play a central role in many exotic nonequilibrium phenomena of ion dynamics in an electrolyte. However, the fundamental equations [i.e., the nonsteady Poisson-Nernst-Planck (PNP) equations] have not been solved analytically at high applied voltages because of their large nonlinearity. In this study, on the basis of the steady PNP solution, we propose an electrical circuit model that considers transient space charge effects and find that the dc and ac responses of the total charge of the electrical double layer are in fairly good agreement with the numerical results even at large applied voltages. Furthermore, on the basis of this model, we find approximate analytical solutions for the nonsteady PNP equations that are in good agreement with the numerical solutions of the concentration, charge density, and potential distribution at high applied voltages at each time in a surface region.

  3. A high-speed electrical impedance measurement circuit based on information-filtering demodulation

    International Nuclear Information System (INIS)

    In the paper, an information-filtering demodulation method is proposed and a high-speed ac-based electrical impedance measurement circuit with a simple configuration is presented. As a crucial part of the ac-based impedance measurement circuit, the information-filtering demodulator can output a preliminary demodulation result by processing only a small number of sampling data within a signal period and the signal-to-noise ratio (SNR) can be further improved by involving more sampling data. Compared with other digital demodulators requiring integer multiples of the signal's period, the information-filtering demodulator is more advantageous in flexibility. Moreover, compared with the recursive least-squares-based demodulator, the proposed demodulator is of relatively low computation complexity and suitable to be implemented on a field programmable gate array. Using this demodulator, the ac impedance measurement circuit based on the ac self-balancing bridge can achieve a high measurement speed. Experimental results showed that one measurement can be accomplished in 17 µs, corresponding to one-third of the signal period, at an excitation frequency of 20 kHz, and the demodulation SNR can reach up to 65 dB. If the data of a complete signal period are used for demodulation like other widely used digital demodulators, the SNR of amplitude demodulation will be higher than 75 dB and the standard deviation of the demodulated phase is below 0.012°, which validates the good performance of both the new demodulator and the impedance measurement circuit. (paper)

  4. A high-speed electrical impedance measurement circuit based on information-filtering demodulation

    Science.gov (United States)

    Sun, Shijie; Xu, Lijun; Cao, Zhang; Zhou, Haili; Yang, Wuqiang

    2014-07-01

    In the paper, an information-filtering demodulation method is proposed and a high-speed ac-based electrical impedance measurement circuit with a simple configuration is presented. As a crucial part of the ac-based impedance measurement circuit, the information-filtering demodulator can output a preliminary demodulation result by processing only a small number of sampling data within a signal period and the signal-to-noise ratio (SNR) can be further improved by involving more sampling data. Compared with other digital demodulators requiring integer multiples of the signal's period, the information-filtering demodulator is more advantageous in flexibility. Moreover, compared with the recursive least-squares-based demodulator, the proposed demodulator is of relatively low computation complexity and suitable to be implemented on a field programmable gate array. Using this demodulator, the ac impedance measurement circuit based on the ac self-balancing bridge can achieve a high measurement speed. Experimental results showed that one measurement can be accomplished in 17 µs, corresponding to one-third of the signal period, at an excitation frequency of 20 kHz, and the demodulation SNR can reach up to 65 dB. If the data of a complete signal period are used for demodulation like other widely used digital demodulators, the SNR of amplitude demodulation will be higher than 75 dB and the standard deviation of the demodulated phase is below 0.012°, which validates the good performance of both the new demodulator and the impedance measurement circuit.

  5. Atmospheric Electric Field Measurements at 100 Hz and High Frequency Electric Phenomena

    Science.gov (United States)

    Conceição, Ricardo; Gonçalves da Silva, Hugo; Matthews, James; Bennett, Alec; Chubb, John

    2016-04-01

    Spectral response of Atmospheric Electric Potential Gradient (PG), symmetric to the Atmospheric Electric Field, gives important information about phenomena affecting these measurements with characteristic time-scales that appear in the spectra as specific periodicities. This is the case of urban pollution that has a clear weekly dependence and reveals itself on PG measurements by a ~7 day periodicity (Silva et al., 2014). While long-term time-scales (low frequencies) have been exhaustively explored in literature, short-term time-scales (high frequencies), above 1 Hz, have comparatively received much less attention (Anisimov et al., 1999). This is mainly because of the technical difficulties related with the storage of such a huge amount of data (for 100 Hz sampling two days of data uses a ~1 Gb file) and the response degradation of the field-meters at such frequencies. Nevertheless, important Electric Phenomena occurs for frequencies above 1 Hz that are worth pursuing, e.g. the Schumann Resonances have a signature of worldwide thunderstorm activity at frequencies that go from ~8 up to ~40 Hz. To that end the present work shows preliminary results on PG measurements at 100 Hz that took place on two clear-sky days (17th and 18th June 2015) on the South of Portugal, Évora (38.50° N, 7.91° W). The field-mill used is a JCI 131F installed in the University of Évora campus (at 2 m height) with a few trees and two buildings in its surroundings (~50 m away). This device was developed by John Chubb (Chubb, 2014) and manufactured by Chilworth (UK). It was calibrated in December 2013 and recent work by the author (who is honored in this study for his overwhelming contribution to atmospheric electricity) reveals basically a flat spectral response of the device up to frequencies of 100 Hz (Chubb, 2015). This makes this device suitable for the study of High Frequency Electric Phenomena. Anisimov, S.V., et al. (1999). On the generation and evolution of aeroelectric structures

  6. The measurement principles for the principal parameters of atmospheric electricity - Experimental results for a slightly polluted marine atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Renoux, A. (Brest, Universite, Brest, France); Paugam, J.Y. (Commissariat a l' Energie Atomique, Laboratoire de Physique de l' Atmosphere, Fontenay-aux-Roses, Hauts-de-Seine, France)

    1979-10-01

    The theories underlying various methods for measuring the electrical parameters of the atmosphere are examined, and results of an experimental investigation of the principal electrical parameters of the slightly polluted atmosphere along the coast near Brest, France are presented. The origins of atmospheric electricity are reviewed, and the use of the field mill electrostatic voltmeter, the Gerdien tube cylindrical condenser, the Obolensky direct filtration method and the Kasemir matching method to measure atmospheric electric field, unipolar conductivity, space charge and vertical currents, respectively, is outlined. Measurements of these parameters reveal elevated values of the electric field and space charge, small total conductivities and a marked dissymmetry of unipolar conductivities during the summer at the coast, with lesser fields and space charges and greater conductivities during the winter, in contrast to the situation inland, where the electric field is weak, space charge moderate, and conductivities are symmetric and elevated.

  7. Combined Aircraft and Satellite-Derived Storm Electric Current and Lightning Rates Measurements and Implications for the Global Electric Circuit

    Science.gov (United States)

    Mach, Douglas M.; Blakeslee, Richard J.; Bateman, Monte G.

    2010-01-01

    Using rotating vane electric field mills and Gerdien capacitors, we measured the electric field profile and conductivity during 850 overflights of electrified shower clouds and thunderstorms spanning regions including the Southeastern United States, the Western Atlantic Ocean, the Gulf of Mexico, Central America and adjacent oceans, Central Brazil, and the South Pacific. The overflights include storms over land and ocean, with and without lightning, and with positive and negative fields above the storms. The measurements were made with the NASA ER-2 and the Altus-II high altitude aircrafts. Peak electric fields, with lightning transients removed, ranged from -1.0 kV/m to 16 kV/m, with a mean value of 0.9 kV/m. The median peak field was 0.29 kV/m. Integrating our electric field and conductivity data, we determined total conduction currents and flash rates for each overpass. With knowledge of the storm location (land or ocean) and type (with or without lightning), we determine the mean currents by location and type. The mean current for ocean storms with lightning is 1.6 A while the mean current for land storms with lightning is 1.0 A. The mean current for oceanic storms without lightning (i.e., electrified shower clouds) is 0.39 A and the mean current for land storms without lightning is 0.13 A. Thus, on average, land storms with or without lightning have about half the mean current as their corresponding oceanic storm counterparts. Over three-quarters (78%) of the land storms had detectable lightning, while less than half (43%) of the oceanic storms had lightning. We did not find any significant regional or latitudinal based patterns in our total conduction currents. By combining the aircraft derived storm currents and flash rates with diurnal lightning statistics derived from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) low Earth orbiting satellites, we reproduce the diurnal variation in the global electric circuit (i.e., the Carnegie

  8. Charging of aerosol and nucleation in atmospheric pressure electrical discharges

    Energy Technology Data Exchange (ETDEWEB)

    Borra, J P [Laboratoire de Physique des Gaz et Plasmas, CNRS-Univ. Paris-Sud, F-91405, SUPELEC, 3 Rue Joliot Curie, Gif-sur-Yvette, F-91192 (France)], E-mail: jp.borra@pgp.u-psud.fr

    2008-12-15

    The paper focuses on applications of atmospheric pressure plasmas (dc corona, streamer, spark and ac dielectric barrier discharges (DBDs)) in aerosol processes for materials and environment. Since aerosol kinematics depends mainly on electric forces acting on charged particles, the two mechanisms of aerosol charging by the collection of ions are presented in corona, post-corona and DBDs. In such defined charging conditions, field and diffusion charging laws are depicted, with respect to applications of controlled kinematics of charged aerosol. Then key parameters controlling the formation by nucleation and the growth by coagulation of particles in plasmas are presented. Sources of vapor leading to nucleated nanoparticles are depicted in atmospheric pressure electrical discharges: (i) when filamentary dc streamer and spark as well as ac-DBDs interact with metal or dielectric surfaces and (ii) when discharges induce reactions with gaseous precursors in volume. In both cases, condensable gaseous species are produced, leading to nano-sized particles by physical and chemical routes of nucleation. The composition, size and structure of primary nanoparticles as well as the final size of agglomerates are related to plasma parameters (energy, number per unit surface and time and thermal gradients around each filament as well as the transit time)

  9. An improved electrical and thermal model of a microbolometer for electronic circuit simulation

    Science.gov (United States)

    Würfel, D.; Vogt, H.

    2012-09-01

    The need for uncooled infrared focal plane arrays (IRFPA) for imaging systems has increased since the beginning of the nineties. Examples for the application of IRFPAs are thermography, pedestrian detection for automotives, fire fighting, and infrared spectroscopy. It is very important to have a correct electro-optical model for the simulation of the microbolometer during the development of the readout integrated circuit (ROIC) used for IRFPAs. The microbolometer as the sensing element absorbs infrared radiation which leads to a change of its temperature due to a very good thermal insulation. In conjunction with a high temperature coefficient of resistance (TCR) of the sensing material (typical vanadium oxide or amorphous silicon) this temperature change results in a change of the electrical resistance. During readout, electrical power is dissipated in the microbolometer, which increases the temperature continuously. The standard model for the electro-optical simulation of a microbolometer includes the radiation emitted by an observed blackbody, radiation emitted by the substrate, radiation emitted by the microbolometer itself to the surrounding, a heat loss through the legs which connect the microbolometer electrically and mechanically to the substrate, and the electrical power dissipation during readout of the microbolometer (Wood, 1997). The improved model presented in this paper takes a closer look on additional radiation effects in a real IR camera system, for example the radiation emitted by the casing and the lens. The proposed model will consider that some parts of the radiation that is reflected from the casing and the substrate is also absorbed by the microbolometer. Finally, the proposed model will include that some fraction of the radiation is transmitted through the microbolometer at first and then absorbed after the reflection at the surface of the substrate. Compared to the standard model temperature and resistance of the microbolometer can be

  10. Number-Phase Quantization Scheme and the Quantum Effects of a Mesoscopic Electric Circuit at Finite Temperature

    Science.gov (United States)

    Wang, Shuai

    2009-05-01

    For L-C circuit, a new quantized scheme has been proposed in the context of number-phase quantization. In this quantization scheme, the number n of the electric charge q( q= en) is quantized as the charge number operator and the phase difference θ across the capacity is quantized as phase operator. Based on the scheme of number-phase quantization and the thermo field dynamics (TFD), the quantum fluctuations of the charge number and phase difference of a mesoscopic L-C circuit in the thermal vacuum state, the thermal coherent state and the thermal squeezed state have been studied. It is shown that these quantum fluctuations of the charge number and phase difference are related to not only the parameters of circuit, the squeezing parameter, but also the temperature in these quantum states. It is proven that the number-phase quantization scheme is very useful to tackle with quantization of some mesoscopic electric circuits and the quantum effects.

  11. Wireless temperature sensing using temperature-sensitive dielectrics within responding electric fields of open-circuit sensors having no electrical connections

    International Nuclear Information System (INIS)

    All temperature sensors or sensor systems previously developed have one common feature-–the sensors are part of electrically closed circuits and electrical connections are used to form the closed circuits. Using existing frameworks for designing, powering and interrogating sensors, any damage that ruptures the circuit can render the sensor non-functional. In many damage events, it is necessary to identify that the damage has occurred and also continue the measurement. In this paper we report a new temperature sensing method that uses a recently developed technique for designing, powering and interrogating sensors developed at NASA. In lieu of sensors being a collection of components assembled using electrical connections, the open-circuit sensors are patterns of electrically conductive material that can store electric fields and magnetic fields without electrical connections. These sensors are powered using oscillating magnetic fields and respond with their own electric and magnetic fields whose signatures provide temperature information. Because no electrical connections are used, there is no point on the sensor that if damaged renders the sensor non-functional. Damage to the sensor simply shifts the sensor's frequency range, allowing it to continue measurement while damaged. Temperature-sensitive dielectric material is placed within the sensor's responding electric field to modulate the sensor's resonant frequency. Temperature sensitivity and functional temperature range are dependent upon the temperature-sensitive material used and how it is placed within sensor's responding electric field. The principle and design strategies of the open-circuit temperature sensors are discussed and experimental results are presented

  12. Thermosphere and ionosphere response on seismogenic disturbances of the global electric circuit

    Science.gov (United States)

    Karpov, Mikhail; Namgaladze, Aleksandr; Knyazeva, Maria

    2016-04-01

    Conditions of warm, humid and ionized air over the active tectonic faults favor the formation of clouds and generation of the intense vertical electric current between the Earth and ionosphere. The latter arises due to separation and vertical transport of the oppositely charged particles by the gravity force and pressure gradients. Additional transport of charged particles into the ionosphere causes disturbances of the ionosphere plasma (under the action of the electric currents in the E-layer and electromagnetic plasma drift in the F2-layer) and thermosphere neutral gas (via the momentum transfer from electric to neutral particles). The thermosphere and ionosphere variations formed under the action of the electric field created by this vertical electric current have been calculated by using the Upper Atmosphere Model (UAM), and a good agreement was found between observed and the UAM calculated perturbations of the electric field, electron and ion concentrations, total electron content (TEC), ion and electron temperatures as well as wind velocities and neutral gas temeperature and concentrations. The roles of the internal gravity waves and electromagnetic plasma drift in generation of the seismogenic TEC variations are discussed.

  13. 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).

  14. Circuit modeling of the electrical impedance: II. Normal subjects and system reproducibility

    International Nuclear Information System (INIS)

    Part I of this series showed that the five-element circuit model accurately mimics impedances measured using multi-frequency electrical impedance myography (MFEIM), focusing on changes brought on by disease. This paper addresses two requirements which must be met if the method is to qualify for clinical use. First, the extracted parameters must be reproducible over long time periods such as those involved in the treatment of muscular disease, and second, differences amongst normal subjects should be attributable to known differences in the properties of healthy muscle. It applies the method to five muscle groups in 62 healthy subjects, closely following the procedure used earlier for the diseased subjects. Test–retest comparisons show that parameters are reproducible at levels from 6 to 16% (depending on the parameter) over time spans of up to 267 days, levels far below the changes occurring in serious disease. Also, variations with age, gender and muscle location are found to be consistent with established expectations for healthy muscle tissue. We conclude that the combination of MFEIM measurements and five-element circuit analysis genuinely reflects properties of muscle and is reliable enough to recommend its use in following neuromuscular disease. (paper)

  15. Circuit modeling of the electrical impedance: part III. Disuse following bone fracture

    International Nuclear Information System (INIS)

    Multifrequency measurements of the electrical impedance of muscle have been extended to the study of disuse following bone fracture, and analyzed using the five-element circuit model used earlier in the study of the effects of disease. Eighteen subjects recovering from simple fractures on upper or lower limbs were examined (ten males, eight females, aged 18–66). Muscles on uninjured contralateral limbs were used as comparison standards, and results are presented in terms of the ratios p(injured)/p(uninjured), where p stands for the circuit parameter r1, r2, r3, 1/c1 or 1/c2. These are strikingly similar to the diseased-to-healthy ratios for patients with neuromuscular disease, reported in part I of this series. In particular, r1 is virtually unaffected and the ratios for r2, r3, 1/c1 and 1/c2 can be as large as in serious disease. Furthermore, the same pattern of relationships between the parameters is found, suggesting that there is a common underlying mechanism for the impedance changes. Atrophy and fibrosis are examined as candidates for that mechanism, but it is argued that their effects are too small to explain the observed changes. Fundamental considerations aside, the sensitivity, reproducibility and technical simplicity of the technique recommend its use for in-flight assessments of muscles during orbital or interplanetary missions. (paper)

  16. Electrical characterization of atmospheric pressure dielectric barrier discharge in air

    International Nuclear Information System (INIS)

    This paper reports the electrical characterization of dielectric barrier discharge produced at atmospheric pressure using a high voltage power supply operating at 50Hz. The characteristics of the discharge have been studied under different values as such applied voltage and the electrode gap width. The results presented in this work can be helpful in understanding the influence of dielectric material on the nature of the discharge. An attempt has also been made to investigate the influence of ballast resistor on the magnitude of discharge current and also the density of micro-discharges. Our results indicated that with this power supply and electrode geometry, a relatively more homogenous discharge is observed for 3 mm spacing. (author)

  17. Strategy Levels for Guiding Discussion to Promote Explanatory Model Construction in Circuit Electricity

    Science.gov (United States)

    Williams, E. Grant; Clement, John J.

    2007-01-01

    A framework for describing and tracking the whole-class discussion-based teaching strategies used by a teacher to support students' construction and development of explanatory models for concepts in circuit electricity is described. A new type of diagram developed to portray teacher-student discourse patterns facilitated the identification of two distinct types, or levels, of teaching strategies: 1) those that support dialogical or conversational elements of classroom interaction; and 2) those that support cognitive model construction processes. The latter include the higher-level goals of promoting a cycle of Observation, model Generation, model Evaluation, and model Modification. While previous studies have focused primarily on the dialogical strategies that are essential for fostering communication as an enabling condition, the cognitive strategies identified herein are aimed at fostering conceptual model construction.

  18. Investigating the role of model-based reasoning while troubleshooting an electric circuit

    Science.gov (United States)

    Dounas-Frazer, Dimitri R.; Van De Bogart, Kevin L.; Stetzer, MacKenzie R.; Lewandowski, H. J.

    2016-06-01

    We explore the overlap of two nationally recognized learning outcomes for physics lab courses, namely, the ability to model experimental systems and the ability to troubleshoot a malfunctioning apparatus. Modeling and troubleshooting are both nonlinear, recursive processes that involve using models to inform revisions to an apparatus. To probe the overlap of modeling and troubleshooting, we collected audiovisual data from think-aloud activities in which eight pairs of students from two institutions attempted to diagnose and repair a malfunctioning electrical circuit. We characterize the cognitive tasks and model-based reasoning that students employed during this activity. In doing so, we demonstrate that troubleshooting engages students in the core scientific practice of modeling.

  19. Quantifying Demyelination in NK venom treated nerve using its electric circuit model

    Science.gov (United States)

    Das, H. K.; Das, D.; Doley, R.; Sahu, P. P.

    2016-03-01

    Reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. Clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. Here we have developed formulation of nerve conduction velocity (NCV) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from NCV measurements. This approach has been validated and demonstrated with toad nerve model treated with crude Naja kaouthia (NK) venom and also shows the effect of Phospholipase A2 and three finger neurotoxin from NK-venom on peripheral nerve. This opens future scope for non-invasive clinical measurement of demyelination.

  20. Investigating the role of model-based reasoning while troubleshooting an electric circuit

    CERN Document Server

    Dounas-Frazer, Dimitri R; Stetzer, MacKenzie R; Lewandowski, H J

    2016-01-01

    We explore the overlap of two nationally-recognized learning outcomes for physics lab courses, namely, the ability to model experimental systems and the ability to troubleshoot a malfunctioning apparatus. Modeling and troubleshooting are both nonlinear, recursive processes that involve using models to inform revisions to an apparatus. To probe the overlap of modeling and troubleshooting, we collected audiovisual data from think-aloud activities in which eight pairs of students from two institutions attempted to diagnose and repair a malfunctioning electrical circuit. We characterize the cognitive tasks and model-based reasoning that students employed during this activity. In doing so, we demonstrate that troubleshooting engages students in the core scientific practice of modeling.

  1. Memory Elements: A Paradigm Shift in Lagrangian Modeling of Electrical Circuits

    CERN Document Server

    Jeltsema, Dimitri

    2012-01-01

    Meminductors and memcapacitors do not allow a Lagrangian formulation in the classical sense since these elements are nonconservative in nature and the associated energies are not state functions. To circumvent this problem, a different configuration space is considered that, instead of the usual loop charges, consist of time-integrated loop charges. As a result, the corresponding Euler-Lagrange equations provide a set of integrated Kirchhoff voltage laws in terms of the element fluxes. Memristive losses can be included via a second scalar function that has the dimension of action. A dual variational principle follows by considering variations of the integrated node fluxes and yields a set of integrated Kirchhoff current laws in terms of the element charges. Although time-integrated charge is a somewhat unusual quantity in circuit theory, it may be considered as the electrical analogue of a mechanical quantity called absement. Based on this analogy, simple mechanical devices are presented that can serve as did...

  2. Estimation of reactive fluxes in gradient stochastic systems using an analogy with electric circuits

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, M.K., E-mail: cameron@math.umd.edu

    2013-08-15

    Highlights: •The MaxFlux functional should be called the resistivity functional. •A Hamilton–Jacobi approach for computing transition paths in collective variables. •Conversion of the network of reactive channels into an electric circuit. •Test on the Alanine-Dipeptide. Perfect agreement. •Application to the problem of CO escape from Myoglobin. -- Abstract: We propose an approach for finding dominant reactive channels and calculating percentages of reactive flux through each channel in chemical systems driven by a deterministic potential force and a small thermal noise. We assume that the temperature is low enough so that the reactive flux focuses around a finite number of paths connecting the reactant and the product states. These paths can be found in a systematic way by solving a Hamilton–Jacobi equation for the so called MaxFlux functional. We argue that the name “MaxFlux” is misleading: it should be called the resistivity functional instead. Once the network of transition paths is found, one can define an equivalent electric circuit and find the currents through each of its wires. These currents give estimates of the reactive flux along the corresponding transition paths. We test our approach on the problem of finding transition paths in the Alanine-Dipeptide with two dihedral angles where the reactive current can be computed exactly. The percentages of the reactive flux through each reactive channel given by our approach turn out to be in remarkable agreement with the exact ones. We apply this approach to the problem of finding escape paths of a CO molecule from a Myoglobin protein. We find a collection of exit locations and establish percentages of the reactive flux through each of them.

  3. 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.

  4. A time-resolved imaging and electrical study on a high current atmospheric pressure spark discharge

    Science.gov (United States)

    Palomares, J. M.; Kohut, A.; Galbács, G.; Engeln, R.; Geretovszky, Zs.

    2015-12-01

    We present a time-resolved imaging and electrical study of an atmospheric pressure spark discharge. The conditions of the present study are those used for nanoparticle generation in spark discharge generator setups. The oscillatory bipolar spark discharge was generated between two identical Cu electrodes in different configurations (cylindrical flat-end or tipped-end geometries, electrode gap from 0.5 to 4 mm), in a controlled co-axial N2 flow, and was supplied by a high voltage capacitor. Imaging data with nanosecond time resolution were collected using an intensified CCD camera. This data were used to study the time evolution of plasma morphology, total light emission intensity, and the rate of plasma expansion. High voltage and high current probes were employed to collect electrical data about the discharge. The electrical data recorded allowed, among others, the calculation of the equivalent resistance and inductance of the circuit, estimations for the energy dissipated in the spark gap. By combining imaging and electrical data, observations could be made about the correlation of the evolution of total emitted light and the dissipated power. It was also observed that the distribution of light emission of the plasma in the spark gap is uneven, as it exhibits a "hot spot" with an oscillating position in the axial direction, in correlation with the high voltage waveform. The initial expansion rate of the cylindrical plasma front was found to be supersonic; thus, the discharge releases a strong shockwave. Finally, the results on equivalent resistance and channel expansion are comparable to those of unipolar arcs. This shows the spark discharge has a similar behavior to the arc regime during the conductive phase and until the current oscillations stop.

  5. Analogy for Drude's free electron model to promote students' understanding of electric circuits in lower secondary school

    Science.gov (United States)

    de Almeida, Maria José BM; Salvador, Andreia; Costa, Maria Margarida RR

    2014-12-01

    Aiming at a deep understanding of some basic concepts of electric circuits in lower secondary schools, this work introduces an analogy between the behavior of children playing in a school yard with a central lake, subject to different conditions, rules, and stimuli, and Drude's free electron model of metals. Using this analogy from the first school contacts with electric phenomena, one can promote students' understanding of concepts such as electric current, the role of generators, potential difference effects, energy transfer, open and closed circuits, resistances, and their combinations in series and parallel. One believes that through this analogy well-known previous misconceptions of young students about electric circuit behaviors can be overcome. Furthermore, students' understanding will enable them to predict, and justify with self-constructed arguments, the behavior of different elementary circuits. The students' predictions can be verified—as a challenge of self-produced understanding schemes—using laboratory experiments. At a preliminary stage, our previsions were confirmed through a pilot study with three classrooms of 9th level Portuguese students.

  6. Self-Regulated Learning Strategies of Engineering College Students While Learning Electric Circuit Concepts with Enhanced Guided Notes

    Science.gov (United States)

    Lawanto, Oenardi; Santoso, Harry

    2013-01-01

    The current study evaluated engineering college students' self-regulated learning (SRL) strategies while learning electric circuit concepts using enhanced guided notes (EGN). Our goal was to describe how students exercise SRL strategies and how their grade performance changes after using EGN. Two research questions guided the study: (1) To what…

  7. Utility design of electronic circuit

    International Nuclear Information System (INIS)

    This is comprised of eleven chapters about electronic circuit design and utility circuit for electronics, which includes the point of design on electronic circuit like logical circuit, sensor circuit and power circuit, acoustic system, image system, communication system like FSK demodulation circuit, measurement and control system, appliance, operating amplifier, conversion device, counter and timer, sensor circuit, motor control such as DC motor control circuit and stepping motor drive circuit and power device like electric current control circuit.

  8. Atmospheric Electricity Effects of Eastern Mediterranean Dust Storms

    Science.gov (United States)

    Katz, Shai; Yair, Yoav; Yaniv, Roy; Price, Colin

    2016-04-01

    We present atmospheric electrical measurements conducted at the Wise Observatory (WO) in Mizpe-Ramon (30035'N, 34045'E) and Mt. Hermon (30024'N, 35051'E), Israel, during two massive and unique dust storms that occurred over the Eastern Mediterranean region on February 10-11 and September 08-12, 2015. The first event transported Saharan dust from Egypt and the Sinai Peninsula in advance of a warm front of a Cyprus low pressure system. In the second event, dust particles were transported from the Syrian desert, which dominates the north-east border with Iraq, through flow associated with a shallow Persian trough system. In both events the concentrations of PM10 particles measured by the air-quality monitoring network of the Israeli Ministry of the Environment in Beer-Sheba reached values > 2200 μg m-3. Aerosol Optical Thickness (AOT) obtained from the AERONET station in Sde-Boker reached values up to 4.0. The gradual intensification of the first event reached peak values on the February 11th > 1200 μg m-3 and an AOT ~ 1.8, while the second dust storm commenced on September 8th with a sharp increase reaching peak values of 2225 μg m-3 and AOT of 4.0. Measurements of the fair weather vertical electric field (Ez) and of the vertical current density (Jz) were conducted continuously with a 1 minute temporal resolution. During the February event, very large fluctuations in the electrical parameters were measured at the WO. The Ez values changed between +1000 and +8000 V m-1 while the Jz fluctuated between -10 and +20 pA m-2 (this is an order of magnitude larger compared to the fair weather current density of ~2 pA m-2. In contrast, during the September event, Ez values registered at WO were between -430 and +10 V m-1 while the Jz fluctuated between -6 and +3 pA m2. For the September event the Hermon site showed Ez and Jz values fluctuating between -460 and +570 V m-1 and -14.5 and +18 pA m-2 respectively. The electric field and current variability, amplitude and the

  9. Module Twelve: Series AC Resistive-Reactive Circuits; Basic Electricity and Electronics Individualized Learning System.

    Science.gov (United States)

    Bureau of Naval Personnel, Washington, DC.

    The module covers series circuits which contain both resistive and reactive components and methods of solving these circuits for current, voltage, impedance, and phase angle. The module is divided into six lessons: voltage and impedance in AC (alternating current) series circuits, vector computations, rectangular and polar notation, variational…

  10. Circuit analysis for dummies

    CERN Document Server

    Santiago, John

    2013-01-01

    Circuits overloaded from electric circuit analysis? Many universities require that students pursuing a degree in electrical or computer engineering take an Electric Circuit Analysis course to determine who will ""make the cut"" and continue in the degree program. Circuit Analysis For Dummies will help these students to better understand electric circuit analysis by presenting the information in an effective and straightforward manner. Circuit Analysis For Dummies gives you clear-cut information about the topics covered in an electric circuit analysis courses to help

  11. Reactor facility for district heating with atmospheric pressure in the primary circuit (RUTA-70)

    International Nuclear Information System (INIS)

    The RUTA-70 is a Russian abbreviation for the reactor facility of 70 MW(th) for district heating with atmospheric pressure in the primary circuit. Single-purpose nuclear heating plants (NHP) are regarded as the possible sources of heat supply for district heating in Russia. A challenging design in this area is the reactor facility RUTA designed specifically as a heat source for district heating systems. A reliable and simple design of the RUTA is ensured, first of all, by the lack of excess pressure in the primary coolant (in the reactor pool). NHPs with such reactors are characterized by inherent safety features and could be located in the immediate vicinity of the heat users. NHPs with the RUTA reactors are suitable for heat supply to urban areas with a p population in the range of 10 to 100 thousand people. In 1990, the Research and Development Institute of Power Engineering of the Rosatom of the Russian Federation (NIKIET) with the participation of IPPE (Obninsk, Russia) has developed the conceptual design of the RUTA plant with a 20 MW(th) output. In 1992, based on this design, the Russian organizations NIKIET, IPPE, VNIPIET and the Mining Institute of the Kola Research Centre of the Russian Academy of Sciences (MI KRC RAS) prepared a feasibility report called 'Designing of the underground NHP with the RUTA reactor for district heating of Apatity, Murmansk region', where it was suggested to use two reactors of 20 MW(th) each for the identified purpose. When discussing these proposals with the town council of Apatity and with the authorities of the Murmansk region, it was considered feasible to develop the design of the RUTA NHP for Apatity and several smaller towns with the unit power output of the reactor increased to 50-60 MW(th). The feasibility report, 'Underground NHP with the RUTA reactors of 4 x 55 MW(th) output for district heating in Apatity, Murmansk region', was prepared in 1994 by joint efforts of specialists from the NIKIET, IPPE, VNIPIET, MI KRC

  12. Initial effect of the Fukushima accident on atmospheric electricity

    Science.gov (United States)

    Takeda, M.; Yamauchi, M.; Makino, M.; Owada, T.

    2011-08-01

    Vertical atmospheric DC electric field at ground level, or potential gradient (PG), suddenly dropped by one order of magnitude at Kakioka, 150 km southwest from the Fukushima Dai-ichi nuclear power plant (FNPP) right after the plant released a massive amount of radioactive material southward on 14 March, 2011. The PG stayed at this level for days with very small daily variations. Such a long-lasting near-steady low PG has never been observed at Kakioka. The sudden drop of PG with one-hour time scale is similar to those associated with rain-induced radioactive fallout after nuclear tests and the Chernobyl disaster. A comparison with the PG data with the radiation dose rate data at different places revealed that arrival of the radioactive dust by low-altitude wind caused the PG drop without rain. Furthermore, the PG might have reflected a minor release several hours before this release at the distance of 150 km. It is recommended that all nuclear power plant to have a network of PG observation surrounding the plant.

  13. Influence factor analysis of atmospheric electric field monitoring near ground under different weather conditions

    International Nuclear Information System (INIS)

    Monitoring of atmospheric electric field near ground plays a critical role in atmospheric environment detecting and lightning warning. Different environmental conditions (e.g. buildings, plants, weather, etc.) have different influences on the data's coherence in an atmospheric electric field detection network. In order to study the main influence factors of atmospheric electric field monitoring under different weather conditions, with the combination of theoretical analysis and experiments, the electric field monitoring data on the ground and on the top of a building are compared in fair weather and thunderstorm weather respectively in this paper. The results show that: In fair weather, the field distortion due to the buildings is the main influence factor on the electric field monitoring. In thunderstorm weather, the corona ions produced from the ground, besides the field distortion due to the buildings, can also influence the electric field monitoring results.

  14. Application of physical electric circuit modeling to characterize Li-ion battery electrochemical processes

    Science.gov (United States)

    Greenleaf, M.; Li, H.; Zheng, J. P.

    2014-12-01

    A physical electric circuit model (PECM) was used to identify several electrochemical processes occurring in two commercial Li-ion batteries of different cathode materials (LixFePO4 and LixCoO2) via electrochemical impedance spectroscopy (EIS). Through defining these electrochemical processes in these two cells, it was determined that the charge transfer resistance (or exchange current density) observed via EIS was due to the cathodic exchange current densities in both the LixFePO4 and LixCoO2 full cells. In discussing the ionic diffusion of the examined cells, the anode of one cell and the cathode of the other were primarily responsible for the observed diffusion of the full cells. Lastly, the measured double layer capacitance was determined to be represented in EIS scans by the anodes of both full cells. The diffusion coefficient was calculated using Fick's1st Law estimation, and from this coefficient, the particle size was calculated and evaluated against scanning electron microscopy (SEM).

  15. Investigation on critical breakdown electric field of hot sulfur hexafluoride/carbon tetrafluoride mixtures for high voltage circuit breaker applications

    Science.gov (United States)

    Wang, Weizong; Murphy, Anthony B.; Rong, Mingzhe; Looe, Hui M.; Spencer, Joseph W.

    2013-09-01

    Sulfur hexafluoride (SF6) gas, widely used in high-voltage circuit breakers, has a high global warming potential and hence substitutes are being sought. The use of a mixture of carbon tetrafluoride (CF4) and SF6 is examined here. It is known that this reduces the breakdown voltage at room temperature. However, the electrical breakdown in a circuit breaker after arc interruption occurs in a hot gas environment, with a complicated species composition because of the occurrence of dissociation and other reactions. The likelihood of breakdown depends on the electron interactions with all these species. The critical reduced electric field strength (the field at which breakdown can occur, relative to the number density) of hot SF6/CF4 mixtures corresponding to the dielectric recovery phase of a high voltage circuit breaker is calculated in the temperature range from 300 K to 3500 K. The equilibrium compositions of hot SF6/CF4 mixtures under different mixing fractions were determined based on Gibbs free energy minimization. Full sets of improved cross sections for interactions between electrons and the species present are presented. The critical reduced electric field strength of these mixtures was obtained by balancing electron generation and loss mechanisms. These were evaluated using the electron energy distribution function derived from the Boltzmann transport equation under the two-term approximation. The result indicates that critical electric field strength decreases with increasing heavy-particle temperature from 1500 to 3500 K. Good agreement was found between calculations for pure hot SF6 and pure hot CF4 and experimental results and previous calculations. The addition of CF4 to SF6 was found to increase the critical reduced electric field strength for temperatures above 1500 K, indicating the potential of replacing SF6 by SF6/CF4 mixtures in high-voltage circuit breakers.

  16. NRC Information No. 87-41: Failures of certain Brown Boveri Electric circuit breakers

    International Nuclear Information System (INIS)

    On April 20, 1987, Duquesne Light Company, the Beaver Valley Unit 2 licensee, notified the NRC of the failure of a BBE Type 5HK Class IE 4-KV circuit breaker. When the circuit breaker was racked onto the bus and 125-V DC control power was applied to the breaker's control circuit, the closing spring charged and the circuit breaker immediately closed and opened several times before the control power could be turned off. The licensee determined by field testing that the closing coil was not being energized. Another problem with BBE circuit breakers occurred at River Bend and was reported March 6, 1987. On February 6, 1987, with the unit at full power, the Division I diesel generator 4.16-KV output circuit breaker (Gould-Brown Boveri Type 5HK) failed to close during a weekly surveillance test. The licensee's inspection of the output circuit breaker revealed that a mounting bolt had fallen out of the closing spring charging motor, rendering the motor inoperable. Further investigation revealed several other circuit breakers that contained loose or missing charging motor mounting bolts. The licensee also stated that the River Bend circuit breaker preventive maintenance program, which the licensee believes to be in accordance with the vendor's recommendations, did not detect this problem. The licensee believes the root cause of the problem to be insufficient torquing of the charging motor mounting bolts by the vendor

  17. Alternating current multi-circuit electric machines a new approach to the steady-state parameter determination

    CERN Document Server

    Asanbayev, Valentin

    2015-01-01

    This book details an approach for realization of the field decomposition concept. The book presents the  methods as well as techniques and procedures for establishing electric machine circuit-loops and determining their parameters. The methods developed have been realized using the models of machines with laminated and solid rotor having classical structure. The use of such models are well recognized and simplifies practical implementation of the obtained results. This book also: ·         Includes methods for a construction of electric machine equivalent circuits that allows the replacement of the field models of the machine with simple circuit models ·         Demonstrates the practical implementation of the proposed techniques and procedures ·         Presents parameters of the circuit-loops in the form most convenient for practical implementation ·         Uses methods based on machine models widely used in practice

  18. Constructional details for A simple atmospheric electrical instrument for educational use

    CERN Document Server

    Bennett, A J

    2007-01-01

    Electricity in the atmosphere provides an ideal topic for educational outreach in environmental science. To support this objective, a simple instrument to measure real atmospheric electrical parameters has been developed and its performance evaluated. This project compliments educational activities undertaken by the Coupling of Atmospheric Layers (CAL) European research collaboration. The new instrument is inexpensive to construct and simple to operate, readily allowing it to be used in schools as well as at the undergraduate University level. It is suited to students at a variety of different educational levels, as the results can be analysed with different levels of sophistication. Students can make measurements of the fair weather electric field and current density, thereby gaining an understanding of the electrical nature of the atmosphere. This work was stimulated by the centenary of the 1906 paper in which C.T.R. Wilson described a new apparatus to measure the electric field and conduction current densi...

  19. A Coupled Dynamical Model of Redox Flow Battery Based on Chemical Reaction, Fluid Flow, and Electrical Circuit

    OpenAIRE

    Li, Minghua; Hikihara, Takashi

    2008-01-01

    The redox (Reduction-Oxidation) flow battery is one of the most promising rechargeable batteries due to its ability to average loads and output of power sources. The transient characteristics are well known as the remarkable feature of the battery. Then it can also compensate for a sudden voltage drop. The dynamics are governed by the chemical reactions, fluid flow, and electrical circuit of its structure. This causes the difficulty of the analysis at transient state. This paper discusses the...

  20. On the role of non-electrified clouds in the Global Electric Circuit

    Directory of Open Access Journals (Sweden)

    A. J. G. Baumgaertner

    2014-04-01

    Full Text Available Non-electrified clouds in the fair-weather part of the Global Electric Circuit (GEC reduce conductivity because of the limited mobility of charge due to attachment to cloud water droplets, effectively leading to a loss of ions. A high-resolution GEC model, which numerically solves the Poisson equation, is used to show that in the fair-weather region currents partially flow around non-electrified clouds, with current divergence above the cloud, and convergence below the cloud. An analysis of this effect is presented for various types of non-electrified clouds, i.e. for different altitude extents, and for different horizontal dimensions, finding that the effect is most pronounced for high clouds with a diameter below 100 km. Based on these results, a method to calculate column and global resistance is developed that can account for all cloud sizes and altitudes. The CESM1(WACCM Earth System Model as well as ISCCP cloud data are used to calculate the effect of this phenomenon on global resistance. From CESM1(WACCM, it is found that when including non-electrified clouds in the fair-weather estimate of resistance the global resistance increases by up to 73%, depending on the parameters used. Using ISCCP cloud cover leads to an even larger increase, which is likely to be overestimated because of time-averaging of cloud cover. Neglecting current divergence/convergence around small clouds overestimates global resistance by up to 20%, whereas the method introduced by previous studies underestimates global resistance by up to 40%. For global GEC models, a conductivity parametrization is developed to account for the current divergence/convergence phenomenon around non-electrified clouds. Conductivity simulations from CESM1(WACCM using this parametrization are presented.

  1. Influence of atmospheric electric fields on the radio emission from extensive air showers

    Science.gov (United States)

    Trinh, T. N. G.; Scholten, O.; Buitink, S.; van den Berg, A. M.; Corstanje, A.; Ebert, U.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Köhn, C.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Rutjes, C.; Schellart, P.; Thoudam, S.; ter Veen, S.; de Vries, K. D.

    2016-01-01

    The atmospheric electric fields in thunderclouds have been shown to significantly modify the intensity and polarization patterns of the radio footprint of cosmic-ray-induced extensive air showers. Simulations indicated a very nonlinear dependence of the signal strength in the frequency window of 30-80 MHz on the magnitude of the atmospheric electric field. In this work we present an explanation of this dependence based on Monte Carlo simulations, supported by arguments based on electron dynamics in air showers and expressed in terms of a simplified model. We show that by extending the frequency window to lower frequencies, additional sensitivity to the atmospheric electric field is obtained.

  2. Influence of Atmospheric Electric Fields on the Radio Emission from Extensive Air Showers

    CERN Document Server

    Trinh, T N G; Buitink, S; Berg, A M van den; Corstanje, A; Ebert, U; Enriquez, J E; Falcke, H; Hörandel, J R; Köhn, C; Nelles, A; Rachen, J P; Rossetto, L; Rutjes, C; Schellart, P; Thoudam, S; ter Veen, S; de Vries, K D

    2016-01-01

    The atmospheric electric fields in thunderclouds have been shown to significantly modify the intensity and polarization patterns of the radio footprint of cosmic-ray-induced extensive air showers. Simulations indicated a very non-linear dependence of the signal strength in the frequency window of 30-80 MHz on the magnitude of the atmospheric electric field. In this work we present an explanation of this dependence based on Monte-Carlo simulations, supported by arguments based on electron dynamics in air showers and expressed in terms of a simplified model. We show that by extending the frequency window to lower frequencies additional sensitivity to the atmospheric electric field is obtained.

  3. Disassembly and physical separation of electric/electronic components layered in printed circuit boards (PCB)

    International Nuclear Information System (INIS)

    Highlights: ► The disassembly of electric/electronic components (EECs) layered in PCB as the first-step in recycling process. ► The disassembling treatment was carried out by the new designed apparatus. ► Most of the EECs (over 95%) can be recovered in a nondestructive state. ► These EECs contain 17 groups and can be classified into 54 types based on their shapes and sizes. ► The successive 3 stages of physical separation would enables the recovery of minor ingredients. - Abstract: Although printed circuit boards (PCBs) contain various elements, only the major elements (i.e., those with content levels in wt% or over grade) of and precious metals (e.g., Ag, Au, and platinum groups) contained within PCBs can be recycled. To recover other elements from PCBs, the PCBs should be properly disassembled as the first step of the recycling process. The recovery of these other elements would be beneficial for efforts to conserve scarce resources, reuse electric/electronic components (EECs), and eliminate environmental problems. This paper examines the disassembly of EECs from wasted PCBs (WPCBs) and the physical separation of these EECs using a self-designed disassembling apparatus and a 3-step separation process of sieving, magnetic separation, and dense medium separation. The disassembling efficiencies were evaluated by using the ratio of grinding area (Earea) and the weight ratio of the detached EECs (Eweight). In the disassembly treatment, these efficiencies were improved with an increase of grinder speed and grinder height. 97.7% (Earea) and 98% (Eweight) could be accomplished ultimately by 3 repetitive treatments at a grinder speed of 5500 rpm and a grinder height of 1.5 mm. Through a series of physical separations, most groups of the EECs (except for the diode, transistor, and IC chip groups) could be sorted at a relatively high separation efficiency of about 75% or more. To evaluate the separation efficiency with regard to the elemental composition, the

  4. Coupled mechanical-electrical-thermal modeling for short-circuit prediction in a lithium-ion cell under mechanical abuse

    Science.gov (United States)

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

    2015-09-01

    In order to better understand the behavior of lithium-ion batteries under mechanical abuse, a coupled modeling methodology encompassing the mechanical, electrical and thermal response is presented for predicting short-circuit under external crush. The combined mechanical-electrical-thermal response is simulated in a commercial finite element software LS-DYNA® using a representative-sandwich finite-element model, where electrical-thermal modeling is conducted after an instantaneous mechanical crush. The model includes an explicit representation of each individual component such as the active material, current collector, separator, etc., and predicts their mechanical deformation under quasi-static indentation. Model predictions show good agreement with experiments: the fracture of the battery structure under an indentation test is accurately predicted. The electrical-thermal simulation predicts the current density and temperature distribution in a reasonable manner. Whereas previously reported models consider the mechanical response exclusively, we use the electrical contact between active materials following the failure of the separator as a criterion for short-circuit. These results are used to build a lumped representative sandwich model that is computationally efficient and captures behavior at the cell level without resolving the individual layers.

  5. 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.

  6. Electrical safety in flammable gas/vapor laden atmospheres

    CERN Document Server

    Korver, WOE

    1992-01-01

    This book provides comprehensive coverage of electrical system installation within areas where flammable gases and liquids are handled and processed. The accurate hazard evaluation of flammability risks associated with chemical and petrochemical locations is critical in determining the point at which the costs of electrical equipment and installation are balanced with explosion safety requirements. The book offers the most current code requirements along with tables and illustrations as analytic tools. Environmental characteristics are covered in Section 1 along with recommended electrical ins

  7. Probing Atmospheric Electric Fields in Thunderstorms through Radio Emission from Cosmic-Ray-Induced Air Showers.

    Science.gov (United States)

    Schellart, P; Trinh, T N G; Buitink, S; Corstanje, A; Enriquez, J E; Falcke, H; Hörandel, J R; Nelles, A; Rachen, J P; Rossetto, L; Scholten, O; Ter Veen, S; Thoudam, S; Ebert, U; Koehn, C; Rutjes, C; Alexov, A; Anderson, J M; Avruch, I M; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brüggen, M; Butcher, H R; Ciardi, B; de Geus, E; de Vos, M; Duscha, S; Eislöffel, J; Fallows, R A; Frieswijk, W; Garrett, M A; Grießmeier, J; Gunst, A W; Heald, G; Hessels, J W T; Hoeft, M; Holties, H A; Juette, E; Kondratiev, V I; Kuniyoshi, M; Kuper, G; Mann, G; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Moldon, J; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H; Scaife, A M M; Schwarz, D J; Serylak, M; Smirnov, O; Steinmetz, M; Swinbank, J; Tagger, M; Tasse, C; Toribio, M C; van Weeren, R J; Vermeulen, R; Vocks, C; Wise, M W; Wucknitz, O; Zarka, P

    2015-04-24

    We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields. PMID:25955053

  8. Probing Atmospheric Electric Fields in Thunderstorms through Radio Emission from Cosmic-Ray-Induced Air Showers

    CERN Document Server

    Schellart, P; Buitink, S; Corstanje, A; Enriquez, J E; Falcke, H; Hörandel, J R; Nelles, A; Rachen, J P; Rossetto, L; Scholten, O; ter Veen, S; Thoudam, S; Ebert, U; Koehn, C; Rutjes, C; Alexov, A; Anderson, J M; Avruch, I M; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brüggen, M; Butcher, H R; Ciardi, B; de Geus, E; de Vos, M; Duscha, S; Eislöffel, J; Fallows, R A; Frieswijk, W; Garrett, M A; Grießmeier, J; Gunst, A W; Heald, G; Hessels, J W T; Hoeft, M; Holties, H A; Juette, E; Kondratiev, V I; Kuniyoshi, M; Kuper, G; Mann, G; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Moldon, J; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H; Scaife, A M M; Schwarz, D J; Serylak, M; Smirnov, O; Steinmetz, M; Swinbank, J; Tagger, M; Tasse, C; Toribio, M C; van Weeren, R J; Vermeulen, R; Vocks, C; Wise, M W; Wucknitz, O; Zarka, P

    2015-01-01

    We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields.

  9. Analysis of Electrical Circuits with Controlled Sources through the Principle of Superposition

    Directory of Open Access Journals (Sweden)

    T. S. Rathore

    2012-07-01

    Full Text Available In the text books, while solving the circuits with controlled sources using Principle of superposition (POS, controlled sources are not deactivated. Thus POS has not been applied in the ‘true sense’ to circuits with dependent sources. It is shown here that POS can be applied in the ‘true sense’ to such circuits also, but with caution. POS is applicable to all those circuits with dependent sources as well, if it is applicable to these circuits when all the dependent sources are treated as independent sources. We have included two such examples: one which cannot be solved only employing series-parallel reduction, current voltage division, and Ohm’s law, second which has more than one controlled sources. The method based on POS is compared with that based on Miller equivalents and generalized matrix method. It is shown that the latter one is the most efficient. It is hoped that the teachers will emphasize that POS can be applied, in the true sense, for analysing circuits with controlled sources. The prospective authors would include this theory in their future text books. However, they should motivate the students to use generalized matrix method for better efficiency.

  10. Improving the electromagnetic compatibility of track circuits with electric rolling stock of double power supply with induction traction motors and electrictraction network

    Directory of Open Access Journals (Sweden)

    N.G. Visin

    2012-04-01

    Full Text Available In this article the research results of many authors on the effect of current interference from the existing electric rolling stock with induction traction motors (ITM on the track circuits and the possibility of exceeding the train traffic safety standards are used. The new promising scheme of power circuit for electric locomotive of double power supply with an ITM applying the intermediary high-frequency transformer for reducing significantly the interference effects to SCB and communication devices is developed.

  11. Formulation of an electric equivalent circuit of PEMFC and its behavioral studies under steady and transient conditions

    International Nuclear Information System (INIS)

    In this paper electric equivalence model is formulated is formulated for the constructional and operational features of a Polymer Electrolyte Membrane Fuel Cell (PEMFC). The proposed model is capable of explaining the behavior of PEMFC in both steady state and transient modes of operation. For the efficient designing of fuel cell related applications it is highly desirable to model the electrical output of fuel cell in terms of its internal electrochemical dynamics. The proposed model includes the phenomenon like activation polarization, ohmic polarization and mass transport effect. An analogical electrical circuit is formulated by taking these phenomena into considerations. Within acceptable limits, the effects of load variation on output voltage, efficiency and fuel flow demands are also investigated. The static and dynamic characteristics obtained through simulations are compared with the standard available data. Simulation results show that the model can be used in PEM fuel cell distributed generation related control studies. (author)

  12. IMPROVING THE RELIABILITY OF THE POWER CIRCUIT OF THE ELECTRIC TRAINS ЕР2Т AND ЕПЛ2Т

    Directory of Open Access Journals (Sweden)

    N. H. Visin

    2010-02-01

    Full Text Available The transitional processes in shunt circuit of traction engines, which armatures and excitation windings are connected in non-conducting direction as to the flowing power current, are considered in this paper. The changes in the control circuits of braking switch and in the shunt power circuit of traction engines with additional mounting a resistor of 0.5 Ohm are proposed. All this modernization will allow increasing greatly the operation reliability of power circuit of ЭР2Т and ЕПЛ2Т electric locomotives during their service life.

  13. 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.

  14. Towards Photonic-Plasmonic Integrated Circuits: Study and Fabrication Of Electrically-Pumped Plasmonic Nano-Laser

    Science.gov (United States)

    Hseih, Chunhan Michael

    For the next generation of optical communication, Photonic Integrated Circuits (PIC) and optoelectronic integrated circuits has been of great interest because of the possibility of integrating multiple optical components and electronics together to give high performance opto-electronic system on a small chip that can be produced cost-effectively. Integrated semiconductor laser, as the main light source for generating signals in optical communications, is one of the most important function on a photonic integrated circuit. In the recent advancements in nanophotonics, strong confinement of light in strongly-guiding optical waveguide structure comparing to conventional structures, has been used to improve certain performances of on-chip semiconductor lasers and miniaturize the laser device sizes. However, compared to electronics, even with use of nanophotonic device technology, optoelectronic device footprints are still relatively large due to the diffraction limit of light, which poses a limit on the sizes of optoelectronic devices. Plasmonic photonic device area has been an intensive field of research that utilizes plamonic photonic waveguides to confine light smaller than the diffraction limit through the effect of surface plasmon polariton, a coupling between photons and plasmon along a metal-dielectric interface. In this dissertation, an electrically pumped Plasmonic nanolaser has been designed using 2D-FDTD simulation. The nanolaser has the potential of lasing utilizing achievable optical gain in the typical compound (group III-V) semiconductor materials. The laser electrical pumping structure is compatible with device integration on silicon photonics platform utilizing silicon-on-insulator (SOI) substrate. Electrically pumped thin film based laser structure is shown to be realizable with the use of TCO material as transparent electrodes on the waveguide cladding. Indium oxide (In2O3) and Zinc-Indium-Tin-Oxide (ZITO) deposited by ion-beam-assisted deposition

  15. Conceptual difficulties experienced by senior high school students of electrochemistry: Electric circuits and oxidation-reduction equations

    Science.gov (United States)

    Garnett, Pamela J.; Treagust, David F.

    The purpose of this research was to investigate students' understanding of electrochemistry following a course of instruction. A list of conceptual and propositional knowledge statements was formulated to identify the knowledge base necessary for students to understand electric circuits and oxidation-reduction equations. The conceptual and propositional knowledge statements provided the framework for the development of a semistructured interview protocol which was administered to 32 students in their final year of high school chemistry. The interview questions about electric circuits revealed that several students in the sample were confused about the nature of electric current both in metallic conductors and in electrolytes. Students studying both physics and chemistry were more confused about current flow in metallic conductors than students who were only studying chemistry. In the section of the interview which focused on oxidation and reduction, many students experienced problems in identifying oxidation-reduction equations. Several misconceptions relating to the inappropriate use of definitions of oxidation and reduction were identified. The data illustrate how students attempted to make sense of the concepts of electrochemistry with the knowledge they had already developed or constructed. The implications of the research are that teachers, curriculum developers, and textbook writers, if they are to minimize potential misconceptions, need to be cognizant of the relationship between physics and chemistry teaching, of the need to test for erroneous preconceptions about current before teaching about electrochemical (galvanic) and electrolytic cells, and of the difficulties experienced by students when using more than one model to explain scientific phenomena.

  16. Electronic meter with custom integrated circuit for electric energy measurement; Medidor eletronico de energia eletrica com circuito integrado dedicado

    Energy Technology Data Exchange (ETDEWEB)

    Caldas, Roberto Pereira

    1990-04-01

    The design and implementation of an electrical energy electronic meter for operation at low voltages, according to two steps of development carried out in Centro de Pesquisas de Energia Eletrica - CEPEL is described. In the first step, an electronic meter with discrete commercial components has been developed, in order to demonstrate to the Brazilian power suppliers the feasibility of such a device for electrical energy metering and charging. The second step was constituted by the design of an integrated circuit, aiming the reduction of the cost of the meter as well as the enhancement of its reliability. Several techniques of electrical energy measurement are presented. The meter with discrete components makes use of a time division multiplier (TDM), in order to determine the active power in the load. Voltage and current levels have been reduced through the use of voltage and current sensors compatible with the TDM's inputs. A V-F converter employing continuos integration, has been used for the determination of the energy consumed by the load through the integration of the TDM's output signal. Most of the discrete components of the meter have been replaced by the dedicated integrated circuit. The TDM has remained essentially the same, but the V-F converter has been changed into a dual-slope one, which is more adequate for implementation in a single chip. The tests performed with the prototypes of the meter including both the meter with discrete components and the meter with the custom-made integrated circuit have presented measurement errors of less the 0,2 %. The initial goal, according to Brazilian specifications of electromechanical meters and international specifications for electronic meters, was 1 %. (author)

  17. System and method to determine electric motor efficiency using an equivalent circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Bin; Habetler, Thomas G.

    2015-10-27

    A system and method for determining electric motor efficiency includes a monitoring system having a processor programmed to determine efficiency of an electric motor under load while the electric motor is online. The determination of motor efficiency is independent of a rotor speed measurement. Further, the efficiency is based on a determination of stator winding resistance, an input voltage, and an input current. The determination of the stator winding resistance occurs while the electric motor under load is online.

  18. Electric fields in the solar atmosphere - A review

    Science.gov (United States)

    Foukal, P.; Hinata, S.

    1991-01-01

    A review is presented of remote sensing techniques which measure the electric field component transverse to the line of sight and achieve a sensitivity range of 5-10 V/cm. Three models are shown to predict quasistatic, macroscopic values of E(parallel), the electric field component parallel to the magnetic vector, beyond the sensitivity range considered. These processes are: the discharge model of flares; the models of return currents related to flare particle beams; and the models of neutral sheets related to two-ribbon flares and postflare loops. Time dependent electric fields related to MHD and plasma waves, and to plasma disturbance, may allow the detection of both E components (parallel and perpendicular). The uncertainty relating to the emission measures, time scales, volumes, and plasma conditions of these flares and electrified plasma volumes is emphasized. It is pointed out, however, that important information can be obtained by observing electric fields at existing sensitivity levels. By measuring these E-fields, the understanding of flares and related dynamic events can be improved.

  19. Optical correlator using very-large-scale integrated circuit/ferroelectric-liquid-crystal electrically addressed spatial light modulators

    Science.gov (United States)

    Turner, Richard M.; Jared, David A.; Sharp, Gary D.; Johnson, Kristina M.

    1993-01-01

    The use of 2-kHz 64 x 64 very-large-scale integrated circuit/ferroelectric-liquid-crystal electrically addressed spatial light modulators as the input and filter planes of a VanderLugt-type optical correlator is discussed. Liquid-crystal layer thickness variations that are present in the devices are analyzed, and the effects on correlator performance are investigated through computer simulations. Experimental results from the very-large-scale-integrated / ferroelectric-liquid-crystal optical-correlator system are presented and are consistent with the level of performance predicted by the simulations.

  20. Testable Subsystems Generation for Fault Detection and Isolation Using a Structural Matching Rank Algorithm Testability of an Electrical Circuit

    Directory of Open Access Journals (Sweden)

    Benazzouz Djamel

    2013-05-01

    Full Text Available In this study, an advanced way of dealing with testable subsystems and residual generation for fault detection and isolation based on structural analysis is presented. The developed technique considers execution issues; therefore, it has a more realistic point of view compared to classical structural approaches available in the literature. First, theoretical aspects of structural analysis are considered and introduced. Then the way of incorporating them to test the structural proprieties is explained. Finally, we show how the proposed (upgraded matching rank algorithm can be used in order to choose the most suited matching that leads to computational sequences and detection tests. The method is demonstrated using an electrical circuit.

  1. High fidelity equivalent circuit representation of induction motor determined by finite elements for electric vehicle drive applications

    Energy Technology Data Exchange (ETDEWEB)

    Vamvakari, A.; Kandianis, A.; Kladas, A.; Manias, S. (National Technical Univ. of Athens (Greece))

    1999-05-01

    The paper presents the methodology for determination of an induction motor model suitable for harmonic representation on inverter supply. Harmonic iron losses are considered by convenient modifications of the standard equivalent circuit while the parameter variations for different operating conditions are determined by finite element modelling. The proposed motor representation is particularly important in cases that the drive efficiency is of major concern over a wide range of operating conditions such as in electrical vehicle applications. The method is illustrated with respect to an experimental set-up involving a 1,5 kW squirrel cage induction motor supplied by a PWM inverter.

  2. Fluctuations of Entropy Production in Partially Masked Electric Circuits: Theoretical Analysis

    OpenAIRE

    Chiang, K. -H.; Chou, C.-W.; Lee, C. -L.; Lai, P. -Y.; Chen, Y. -F.

    2016-01-01

    In this work we perform theoretical analysis about a coupled RC circuit with constant driven currents. Starting from stochastic differential equations, where voltages are subject to thermal noises, we derive time-correlation functions, steady-state distributions and transition probabilities of the system. The validity of the fluctuation theorem (FT) is examined for scenarios with complete and incomplete descriptions.

  3. 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.

  4. Electrical characterization of atmospheric pressure DBD in air

    International Nuclear Information System (INIS)

    Atmospheric pressure dielectric barrier discharge (DBD) in air was generated between two rectangular copper electrodes covering the lower electrode with a dielectric (glass or polycarbonate -PC) using low frequency (line frequency-50Hz) high voltage power supply. The discharge was studied for inter-electrode gap spacing in the range of 2 mm – 5 mm and their influence on breakdown voltage. Voltage-current characteristics and the analysis of the distribution of current pulses per half cycle of the current waveform indicated that the discharge is more uniform in 3 mm inter-electrode gap spacing with PC as a dielectric rather than glass. (author)

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

    Institute of Scientific and Technical Information of China (English)

    Xu Fei; Xiao Dengming; Li Zhaozhi

    2009-01-01

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

  6. STRUCTURAL DAMAGE DETECTION BY DISTRIBUTED PIEZOELECTRIC TRANSDUCERS AND TUNED ELECTRIC CIRCUITS

    OpenAIRE

    Dell'Isola, Francesco; Vestroni, Fabrizio; Vidoli, Stefano

    2005-01-01

    A novel technique for damage detection of structures is introduced and discussed. It is based on purely electric measurements of the state variables of an electric network coupled to the main structure through a distributed set of piezoelectric patches. The constitutive parameters of this auxiliary network are optimized to increase the sensitivity of global measurements- as the frequency, response functions relative to selected electric degrees of freedom-with respect to a given class of vari...

  7. Self-consistent radiation-based simulation of electric arcs: II. Application to gas circuit breakers

    Science.gov (United States)

    Iordanidis, A. A.; Franck, C. M.

    2008-07-01

    An accurate and robust method for radiative heat transfer simulation for arc applications was presented in the previous paper (part I). In this paper a self-consistent mathematical model based on computational fluid dynamics and a rigorous radiative heat transfer model is described. The model is applied to simulate switching arcs in high voltage gas circuit breakers. The accuracy of the model is proven by comparison with experimental data for all arc modes. The ablation-controlled arc model is used to simulate high current PTFE arcs burning in cylindrical tubes. Model accuracy for the lower current arcs is evaluated using experimental data on the axially blown SF6 arc in steady state and arc resistance measurements close to current zero. The complete switching process with the arc going through all three phases is also simulated and compared with the experimental data from an industrial circuit breaker switching test.

  8. Self-consistent radiation-based simulation of electric arcs: II. Application to gas circuit breakers

    International Nuclear Information System (INIS)

    An accurate and robust method for radiative heat transfer simulation for arc applications was presented in the previous paper (part I). In this paper a self-consistent mathematical model based on computational fluid dynamics and a rigorous radiative heat transfer model is described. The model is applied to simulate switching arcs in high voltage gas circuit breakers. The accuracy of the model is proven by comparison with experimental data for all arc modes. The ablation-controlled arc model is used to simulate high current PTFE arcs burning in cylindrical tubes. Model accuracy for the lower current arcs is evaluated using experimental data on the axially blown SF6 arc in steady state and arc resistance measurements close to current zero. The complete switching process with the arc going through all three phases is also simulated and compared with the experimental data from an industrial circuit breaker switching test

  9. Charge Yield at Low Electric Fields: Considerations for Bipolar Integrated Circuits

    Science.gov (United States)

    Johnston, A. H.; Swimm, R. T.; Thorbourn, D. O.

    2013-01-01

    A significant reduction in total dose damage is observed when bipolar integrated circuits are irradiated at low temperature. This can be partially explained by the Onsager theory of recombination, which predicts a strong temperature dependence for charge yield under low-field conditions. Reduced damage occurs for biased as well as unbiased devices because the weak fringing field in thick bipolar oxides only affects charge yield near the Si/SiO2 interface, a relatively small fraction of the total oxide thickness. Lowering the temperature of bipolar ICs - either continuously, or for time periods when they are exposed to high radiation levels - provides an additional degree of freedom to improve total dose performance of bipolar circuits, particularly in space applications.

  10. Student use of model-based reasoning when troubleshooting an electric circuit

    Science.gov (United States)

    Dounas-Frazer, Dimitri

    2016-05-01

    Troubleshooting systems is an integral part of experimental physics in both research and educational settings. Accordingly, ability to troubleshoot is an important learning goal for undergraduate physics lab courses. We investigate students' model-based reasoning on a troubleshooting task using data collected in think-aloud interviews during which pairs of students from two institutions attempted to diagnose and repair a malfunctioning circuit. Our analysis scheme was informed by the Experimental Modeling Framework, which describes physicists' use of mathematical and conceptual models when reasoning about experimental systems. We show that system and subsystem models were crucial for the evaluation of repairs to the circuit and played an important role in some troubleshooting strategies. Finally, drawing on data from interviews with electronics instructors from a broad range of institution types, we outline recommendations for model-based approaches to teaching and learning troubleshooting skills.

  11. An improved electrical and thermal model of a microbolometer for electronic circuit simulation

    OpenAIRE

    D. Würfel; Vogt, H.

    2012-01-01

    The need for uncooled infrared focal plane arrays (IRFPA) for imaging systems has increased since the beginning of the nineties. Examples for the application of IRFPAs are thermography, pedestrian detection for automotives, fire fighting, and infrared spectroscopy. It is very important to have a correct electro-optical model for the simulation of the microbolometer during the development of the readout integrated circuit (ROIC) used for IRFPAs. The microbolometer as the sens...

  12. Completing the Circuit: A Century of Electrical Education at MSM/UMR.

    Science.gov (United States)

    Ridley, Jack B.

    This book records highlights of the development of electrical engineering education at the University of Missouri-Rolla (UMR), first known as the University of Missouri School of Mines and Metallurgy (MSM). Chapter I focuses on the formative years (1871-1924), discussing the first course of study in electricity, expansion of the electrical…

  13. Structural-Damage Detection by Distributed Piezoelectric Transducers and Tuned Electric Circuits

    CERN Document Server

    dell'Isola, F; Vidoli, S

    2010-01-01

    A novel technique for damage detection of structures is introduced and discussed. It is based on purely electric measurements of the state variables of an electric network coupled to the main structure through a distributed set of piezoelectric patches. The constitutive parameters of this auxiliary network are optimized to increase the sensitivity of global measurements- as the frequency, response functions relative to selected electric degrees of freedom-with respect to a given class of variations in the structural-mechanical properties. Because the proposed method is based on purely electric input and output measurements, it allows for accurate results in the identification and localization of damages. Use of the electric frequency-response function to identify the mechanical damage leads to nonconvex optimization problems; therefore the proposed sensitivity-enhanced identification procedure becomes computationally efficient if an a priori knowledge about the damage is available.

  14. Atmospheric electrical field measurements near a fresh water reservoir and the formation of the lake breeze

    Directory of Open Access Journals (Sweden)

    Francisco Lopes

    2016-06-01

    Full Text Available In order to access the effect of the lakes in the atmospheric electrical field, measurements have been carried out near a large man-made lake in southern Portugal, the Alqueva reservoir, during the ALqueva hydro-meteorological EXperiment 2014. The purpose of these conjoint experiments was to study the impact of the Alqueva reservoir on the atmosphere, in particular on the local atmospheric electric environment by comparing measurements taken in the proximity of the lake. Two stations 10 km apart were used, as they were located up- and down-wind of the lake (Amieira and Parque Solar, respectively, in reference to the dominant northwestern wind direction. The up-wind station shows lower atmospheric electric potential gradient (PG values than the ones observed in the down-wind station between 12 and 20 UTC. The difference in the atmospheric electric PG between the up-wind and the down-wind station is ~30 V/m during the day. This differential occurs mainly during the development of a lake breeze, between 10 and 18 UTC, as a consequence of the surface temperature gradient between the surrounding land and the lake water. In the analysis presented, a correlation is found between the atmospheric electric PG differences and both wind speed and temperature gradients over the lake, thus supporting the influence of the lake breeze over the observed PG variation in the two stations. Two hypotheses are provided to explain this observation: (1 The air that flows from the lake into the land station is likely to increase the local electric conductivity through the removal of ground dust and the transport of cleaner air from higher altitudes with significant light ion concentrations. With such an increase in conductivity, it is expected to see a reduction of the atmospheric electric PG; (2 the resulting air flow over the land station carries negative ions formed by wave splashing in the lake's water surface, as a result of the so-called balloelectric effect

  15. Investigation and calculation of valleys of outgoing from substation grounding conductors for short-circuit in single-phase short of electrical grid

    OpenAIRE

    V.I. Nizhevskyi; I.V. Nizhevskyi; Ynoyatov, B.; Nasryddyny, S.

    2015-01-01

    Introduction. Earthing device electrical substation in modern conditions must meet both the requirements of electrical safety of people and animals, as well as electromagnetic compatibility requirements established her electrical equipment. These requirements are intended to address issues of protection against surges and interference caused by lightning impulse currents and switching. Aim. To investigate the distribution of single-phase short-circuit current in the substation grounding devic...

  16. Non-stationary corona around multi-point system in atmospheric electric field: I. Onset electric field and discharge current

    Science.gov (United States)

    Bazelyan, E. M.; Raizer, Yu. P.; Aleksandrov, N. L.

    2014-03-01

    The properties of a non-stationary glow corona maintained near the tips of a multi-point ground system in a time-varying thundercloud electric field have been studied numerically and analytically. Computer and analytical models were developed to simulate the corona discharge initiated from a system of identical vertical conductive electrodes distributed uniformly over a grounded plane surface. The simulation was based on a solution of the electrostatic equation for electric field and continuity equations for light and aerosol ions. The development of individual corona space charge layers from different points and the formation of a united plane layer were considered. The effect of system dimensions and that of the distance between electrodes on the external electric field corresponding to corona onset near the rod tips was investigated. The evolution in time of the corona current was calculated for systems with various numbers of coronating rods in time-varying atmospheric electric field. In the limit of infinite number of coronating rods, reasonable agreement was obtained between numerical calculations and analytical theory considering the effect of surrounding rods on the corona discharge from a given rod in a simplified integral way. Conditions were determined under which the corona properties of a multi-point system are similar to the properties of a plane surface emitting ions into the atmosphere. In this case, the corona current density is governed by the time derivative of the thundercloud electric field and is independent of the ion mobility and of the coronating system dimensions. The total corona space charge injected into the atmosphere per unit area by a given instant is controlled by the thundercloud electric field at this instant and depends on the geometrical parameters of the system only indirectly, through the corona onset atmospheric electric field. This simple model could be used to simulate a corona discharge during thunderstorms at the earth

  17. EXPOSURE TO CARBONIC GAS ENRICHED ATMOSPHERE OR ELECTRICAL WATER BATH TO STUN OR KILL CHICKENS

    OpenAIRE

    JP Nicolau; MF Pinto; EHG Ponsano; SHV Perri; M Garcia Neto

    2015-01-01

    ABSTRACTThe objective of this study was to compare the effects of two methods (electrical water bath or carbonic gas atmosphere) for stunning or killing broiler chickens prior to bleeding on weight loss due to bleeding and meat traits. A completely randomized design with 2 x 2 factorial arrangement (electrical or gas system x stunning or killing) was applied. The time required for stunning and killing and the birds' behavior were evaluated for the gas exposure method. The birds killed by the ...

  18. The electrical charging of inactive aerosols in high ionised atmosphere, the electrical charging of artificial beta radioactive aerosols

    International Nuclear Information System (INIS)

    The electrical properties of aerosols greatly influence their transport and deposition in a containment. In a bipolar ionic atmosphere, a neutral electric charge on aerosols is commonly assumed. However, many studies report a different charge distribution in some situations, like highly ionised atmosphere or in the case of radioactive aerosols. Such situations could arise from a hypothetical accident in a nuclear power plant. Within the framework of safety studies which are carried out at IPSN, our aims were the study of electrical properties of aerosols in highly ionised atmosphere, and the study of artificial radioactive aerosols, in order to suggest experimental validation of available theories. For this purpose, we designed an experimental device that allows us to measure non-radioactive aerosol charge distribution under high gamma irradiation, up to 104 Gy/h. With our experimental device we also studied the properties of small ions in the medium. Our results show a variation of the charge distribution in highly ionised atmosphere. The charge increases with the dose of gamma ray. We have related this variation with the one of the small ions in the gases, according to theoretical prediction. However, the model overestimates slightly our experimental results. In the case of the radioactive aerosols, we have designed an original experimental device, which allows us to study the charge distribution of a 137Cs aerosol. Our results show that the electric charging of such aerosols is strongly dependent on evolution parameters in a containment. So, our results underline a great enhancement of self-charging of particles which are sampled in a confined medium. Our results are qualitatively in agreement with the theoretical model; nevertheless the latter underestimates appreciably the self-charging, owing to the fact that wall effects are not taken into account. (author)

  19. History of Physics as a Tool to Detect the Conceptual Difficulties Experienced by Students: The Case of Simple Electric Circuits in Primary Education

    Science.gov (United States)

    Leone, Matteo

    2014-04-01

    The present paper advocates the use of History of Science into the teaching of science in primary education through a case study in the field of electricity. In this study, which provides both historical and experimental evidence, a number of conceptual difficulties faced by early nineteenth century physicists are shown to be a useful tool to detect 5th grade pupils' conceptions about the simple electric circuits. This result was obtained through the administration of schematics showing circuital situation inspired to early 1800s experiments on the effects of electric current on water electrolysis and on the behaviour of magnetic compasses. It is also shown that the detecting of pupils' alternative ideas about electric current in a circuit is highly dependent on the survey methodology (open ended questions and drawings, multiple-choice item, connecting card work, and history of science tasks were considered in this study) and that the so-called "unipolar model" of electric circuit is more pervasive than previously acknowledged. Finally, a highly significant hybrid model of electric current is identified.

  20. Variation of fair weather atmospheric electricity at Marsta Observatory, Sweden, 1993-1998

    Science.gov (United States)

    Israelsson, S.; Tammet, H.

    2001-11-01

    A modified atmospheric electrical station of the Kasemir-Dolezalek construction is continuously operating in the Marsta Observatory /(59°56'N,17°35'W) located in rural area 10km north of Uppsala, Sweden. The routinely recorded parameters are the electric field, positive and negative polar conductivities of air, and space charge density. The effect of possible local anthropogenic air pollution on the fair weather atmospheric electric measurements at Marsta is estimated according to Sheftel et al., 1994a (J. Geophys. Res. 99, 10,793) by comparing the Sunday and weekday values of air conductivity. The effect of local air pollution appears essentially less than at other evaluated continental atmospheric electric stations. The natural periodic variations of fair weather electric field and vertical air-earth current averaged over many years at Marsta are compared with the periodic variations of electric field measured during the Carnegie expeditions over the oceans where the global component of variations dominates over the local component. The diurnal variations of electric field and vertical current at Marsta are well correlated with the Carnegie curve during winter and ill correlated during summer. The correlation coefficient reaches 98% for the winter measurements of vertical air-earth current. In addition, a test has been carried out for a hypothesis that numerical reduction of the data according to the local temperature and wind variation could suppress the local component of fair weather atmospheric electric variations and thus help to study the global component of variation. The hypothesis proved to be inadequate. The reduction suppresses the annual variation, but the shape of the diurnal variation remains the same and the correlation with the Carnegie curve is even worse than in the case of unreduced measurements. The Marsta Observatory is recommended as a basis station for long-term routine atmospheric electric measurements to gather data for the study of

  1. First results of fair-weather atmospheric electricity measurements in Northeast India

    Indian Academy of Sciences (India)

    A Guha; B K De; S Gurubaran; S S De; K Jeeva

    2010-04-01

    During the month of March 2006, a short campaign was conducted to measure fair-weather atmospheric electricity parameters in Tripura, Northeast India (23.50°N, 91.25°E). The campaign was the first of its kind in this region of the globe. The main objective of the campaign was to characterize the diurnal variation of three parameters namely vertical potential gradient (), vertical air–earth current density (Jz) and atmospheric electrical conductivity () in fair-weather conditions. The diurnal variation of and Jz over sixteen fair-weather days shows two distinct maxima around 14UT and 20UT and a minimum around 03UT. The average vertical potential gradient is found to be 108V·m−1 and air–earth current density 1.85 pA·m−2. The average bipolar atmospheric electrical conductivity at the ground level is found to be 19.6 fS·m−1. An excellent positive correlation between and Jz is found, with a correlation coefficient of 0.96. A comparative study with Carnegie universal variation shows 70% correlation with observed variation of vertical potential gradient during the period of the campaign. The results are discussed in view of difficulty as well as possibility of getting global signatures in atmospheric electricity measurements made from tropical land stations.

  2. Influence of atmospheric electric fields on the radio emission from extensive air showers

    DEFF Research Database (Denmark)

    Trinh, T. N. G.; Scholten, O.; Buitink, S.;

    2016-01-01

    The atmospheric electric fields in thunderclouds have been shown to significantly modify the intensity and polarization patterns of the radio footprint of cosmic-ray-induced extensive air showers. Simulations indicated a very nonlinear dependence of the signal strength in the frequency window of ...

  3. Wideband energy harvesting using a combination of an optimized synchronous electric charge extraction circuit and a bistable harvester

    International Nuclear Information System (INIS)

    The challenge of variable vibration frequencies for energy harvesting calls for the development of wideband energy harvesters. Bistability has been proven to be a potential solution. Optimization of the energy extraction is another important objective for energy harvesting. Nonlinear synchronized switching techniques have demonstrated some of the best performances. This paper presents a novel energy harvesting solution which combines these two techniques: the OSECE (optimized synchronous electric charge extraction) technique is used along with a BSM (buckled-spring–mass) bistable generator to achieve wideband energy harvesting. The effect of the electromechanical coupling coefficient on the harvested power for the bistable harvester with the nonlinear energy extraction technique is discussed for the first time. The performances of the proposed solution for different levels of electromechanical coupling coefficients in the cases of chirp and noise excitations are compared against the performances of the bistable harvester with the standard technique. It is shown that the OSECE technique is a much better option for wideband energy harvesting than the standard circuit. Moreover, the harvested energy is drastically increased for all excitations in the case of low electromechanical coupling coefficients. When the electromechanical coupling coefficient is high, the performance of the OSECE technique is not as good as the standard circuit for forward sweeps, but superior for the reverse sweep and band-limited noise cases. However, considering that real excitation signals are more similar to noise signals, the OSECE technique enhances the performance. (paper)

  4. Development of hydraulic power unit and accumulator charging circuit for electricity generation, storage and distribution

    Institute of Scientific and Technical Information of China (English)

    C.N.Okoye; JIANG Ji-hai; LIU Hai-chang

    2008-01-01

    It is the purpose of the present paper to convert hydraulic energy to electric energy and saves both the pressure and electrical energy for re - use during the next system upstroke using two secondary units coupled to induction motor to drive cylinder loads. During upstroke operation, the variable pump/motor (P/M) driven by both electric motor and the second (P/M) works as hydraulic pump and output flow to the cylinders which drive the load. During load deceleration, the cylinders work as pump while the operation of the two secondary units are reversed, the variable (P/M) works as a motor generating a torque with the electric motor to drive the other(P/M) which transforms mechanical energy to hydraulic energy that is saved in the accumulator. When the en-ergy storage capacity of the accumulator is attained as the operation continues, energy storage to the accumulator is thermostatically stopped while the induction motor begins to work as a generator and generates electricity that is stored in the power distribution unit. Simulations were performed using a limited PT2 Block, I.e. 2nd-ordertransfer function with limitation of slope and signal output to determine suitable velocity of the cylinder which will match high performance and system stability. A mathematical model suited to the simulation of the hydrau-lic accumulator both in an open-or close-loop system is presented. The quest for improvement of lower energy capacity storage, saving and re-utilization of the conventional accumulator resulting in the short cycle time usage of hydraulic accumulators both in domestic and industrial purposes necessitates this research. The outcome of the research appears to be very efficient for generating fluctuation free electricity, power quality and reliability, energy saving/reutilization and system noise reduction.

  5. INVESTIGATION AND CALCULATION OF VALLEYS OF OUTGOING FROM SUBSTATION GROUNDING CONDUCTORS FOR SHORT-CIRCUIT IN SINGLE-PHASE SHORT OF ELECTRICAL GRID

    Directory of Open Access Journals (Sweden)

    V. I. Nizhevskyi

    2015-04-01

    Full Text Available Introduction. Earthing device electrical substation in modern conditions must meet both the requirements of electrical safety of people and animals, as well as electromagnetic compatibility requirements established her electrical equipment. These requirements are intended to address issues of protection against surges and interference caused by lightning impulse currents and switching. Aim. To investigate the distribution of single-phase short-circuit current in the substation grounding devices. Task. On the basis of the proposed design scheme of substitution substation grounding device, consisting of a substation earthing system and «cable-supported» an algorithm for calculating the resistance of the grounding device substation and distribution of single-phase short-circuit current on the circuit elements. Method. Mathematical modeling and calculation engine. Results. On the basis of calculations and studies analyzed the current distribution of single-phase short-circuit between the substation earthing system and earthing «rope-reliance». Studies carried out for the actual range of variation of the circuit parameters, showed that the earthing resistance substation substantially affects the current distribution in the one-phase short circuit fault. For example, using the graph shows that with increasing resistance grounding system of "rope-supported" the proportion of single-phase short-circuit current flowing from the substation earthing increases, while the proportion of single-phase short-circuit current flowing from the grounding device supports decreases and vice versa. In addition, when rationing grounding systems at substations for the touch voltage is necessary to analyze all the possible modes of operation of the network, which is substationed. Conclusion. The results obtained are recommended to take into account in the design of grounding systems at substations.

  6. A study of the main atmospheric electric parameters at a little polluted seashore site

    International Nuclear Information System (INIS)

    In order to study the electric elements of the air near the ground, we realized a set of apparatus for the measurement of several parameters: electric field, space charge, conductivities, air-earth current, as well as an automatic condensation nuclei counter. The characteristics of a very important photolytic process of nuclei production closely related to air exposure of living algae, at daytime low-tide periods were first determined. Then a systematic study of the electrical behaviour of the air at the seashore, was also carried out in relation with meteorological parameters. The results observed by sea winds, and especially the data on electric field and space charge showed out a very strong electrode effect above the sea surface, and were very different from those recorded at another site, 20 km inland. Finally, the atmospheric electric fog effect at the coastline and the possibility of using our results for forecasting the phenomenon were studied. (author)

  7. All-metallic electrically gated 2H-TaSe2 thin-film switches and logic circuits

    International Nuclear Information System (INIS)

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe2 were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe2–Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials

  8. The effects of electrical and controlled atmosphere stunning methods on meat and liver quality of geese.

    Science.gov (United States)

    Turcsán, Z S; Szigeti, J; Varga, L; Farkas, L; Birkás, E; Turcsán, J

    2001-11-01

    The objective of this research was to investigate the effects of electrical and gas stunning on the meat and liver quality characteristics of liver geese. Sixty birds were slaughtered at 12 wk of age, in groups of 20 at three different times. Thirty birds each were subjected to one of the two stunning methods. Deboned breast fillets and thigh muscles were evaluated for hemorrhaging, amount of blood in the veins, and color by using a visual grading system. Livers were removed from carcasses during evisceration and were subsequently graded. Besides external color and hemorrhaging, the degree of liver weight loss due to removal of blood vessels was also determined. The use of controlled atmosphere stunning significantly reduced the incidence of muscle hemorrhages when compared to electrical stunning. However, no significant difference was found for color or amount of blood remaining in the veins of muscles between geese receiving electrical or controlled atmosphere stunning. The hemorrhaging and color scores of livers from gas-stunned birds did not differ from those of electrically stunned birds. As for the liver weight loss caused by removal of veins and capillaries, stunning treatment had no significant effect on this parameter. These results suggest that controlled atmosphere stunning produced slightly better quality goose meat but did not improve liver quality when compared to the electrical stunning method used. PMID:11732683

  9. Ground and CHAMP observations of field-aligned current circuits generated by lower atmospheric disturbances and expectations to the SWARM to clarify their three dimensional structure

    Science.gov (United States)

    Iyemori, Toshihiko; Nakanishi, Kunihito; Aoyama, Tadashi; Lühr, Hermann

    2014-05-01

    Acoustic gravity waves propagated to the ionosphere cause dynamo currents in the ionosphere. They divert along geomagnetic field lines of force to another hemisphere accompanying electric field and then flow in the ionosphere of another hemisphere by the electric field forming closed current circuits. The oscillating current circuits with the period of acoustic waves generate magnetic variations on the ground, and they are observed as long period geomagnetic pulsations. This effect has been detected during big earthquakes, strong typhoons, tornados etc. On a low-altitude satellite orbit, the spatial distribution (i.e., structure) of the current circuits along the satellite orbit should be detected as temporal magnetic oscillations, and the effect is confirmed by a CHAMP data analysis. On the spatial structure, in particular, in the longitudinal direction, it has been difficult to examine by a single satellite or from ground magnetic observations. The SWARM satellites will provide an unique opportunity to clarify the three dimensional structure of the field-aligned current circuits.

  10. Some Key Issues in Creating Inquiry-Based Instructional Practices that Aim at the Understanding of Simple Electric Circuits

    Science.gov (United States)

    Kock, Zeger-Jan; Taconis, Ruurd; Bolhuis, Sanneke; Gravemeijer, Koeno

    2013-04-01

    Many students in secondary schools consider the sciences difficult and unattractive. This applies to physics in particular, a subject in which students attempt to learn and understand numerous theoretical concepts, often without much success. A case in point is the understanding of the concepts current, voltage and resistance in simple electric circuits. In response to these problems, reform initiatives in education strive for a change of the classroom culture, putting emphasis on more authentic contexts and student activities containing elements of inquiry. The challenge then becomes choosing and combining these elements in such a manner that they foster an understanding of theoretical concepts. In this article we reflect on data collected and analyzed from a series of 12 grade 9 physics lessons on simple electric circuits. Drawing from a theoretical framework based on individual (conceptual change based) and socio-cultural views on learning, instruction was designed addressing known conceptual problems and attempting to create a physics (research) culture in the classroom. As the success of the lessons was limited, the focus of the study became to understand which inherent characteristics of inquiry based instruction complicate the process of constructing conceptual understanding. From the analysis of the data collected during the enactment of the lessons three tensions emerged: the tension between open inquiry and student guidance, the tension between students developing their own ideas and getting to know accepted scientific theories, and the tension between fostering scientific interest as part of a scientific research culture and the task oriented school culture. An outlook will be given on the implications for science lessons.

  11. High School Students' Understanding of Resistance in Simple Series Electric Circuits.

    Science.gov (United States)

    Liegeois, Laurent; Mullet, Etienne

    2002-01-01

    Studies the understanding that 8-12 grade high school students were able to develop with regard to the interrelationships between resistance, potential difference, and current concepts (Ohm's law). Explores the immediate effects of exposure to electricity courses on the intuitive mastery of these relationships. (Contains 32 references.)…

  12. Relationship of ground-level aerosol concentration and atmospheric electric field at three observation sites in the Arctic, Antarctic and Europe

    Science.gov (United States)

    Kubicki, Marek; Odzimek, Anna; Neska, Mariusz

    2016-09-01

    Aerosol number concentrations in the particle size range from ~ 10 nm to 1 μm and vertical electric field strength in the surface layer was measured between September 2012 and December 2013 at three observation sites: mid-latitude station Swider, Poland, and, for the first time, in Hornsund in the Arctic, Spitsbergen, and the Antarctic Arctowski station in the South Shetland Islands. The measurements of aerosol concentrations have been performed simultaneously with measurements of the electric field with the aim to assess the local effect of aerosol on the electric field Ez near the ground at the three stations which at present form a network of atmospheric electricity observatories. Measurements have been made regardless of weather conditions at Swider and Arctowski station and mostly on fair-weather days at Hornsund station. The monthly mean particle number concentrations varied between 580 and 2100 particles cm- 3 at Arctowski, between 90 and 1270 particles cm- 3 in Hornsund, and between 6700 and 14,000 particles cm- 3 in the middle latitude station Swider. Average diurnal variations of the ground-level electric field Ez and particle number concentrations in fair-weather conditions were independent of each other for Arctowski and Hornsund stations. At Swider station the diurnal variation is usually characterized by an increase of aerosol concentration in the evening which results in the increased electric field. The assumption of neglecting the influence of varying aerosol concentration on the variation of the electric field in the polar regions, often adopted in studies, is confirmed here by the observations at Arctowski and Hornsund. The results of aerosol observations are also compared with modelled aerosol concentrations for global atmospheric electric circuit models.

  13. Strategy of atmospheric electric field and electromagnetic wave measurements by Mars lander

    Science.gov (United States)

    Takahashi, Yukihiro; Shimizu, Hisayoshi; Ishisaka, Keigo

    Measurement of atmospheric electric field and electromagnetic waves on the ground in Mars is very new and unique approach dedicated not only to the electrical current research but also to the meteorology. Dust devil and storm could be the generator of the currents via dust particle collision process in the very near surface region. If we compare the electric filed near the ground with the dust devil activity, we could clarify the mechanism of dust devil generation. Also the electromagnetic wave measurement makes it possible to know the location and the quantitative strength of dust devil wind only with few observation sites. This measurement also contributes to the studies both on the crust and the upper atmosphere physics. We propose an instrumentation set for the DC and AC electromagnetic observation installed at MArs lander.

  14. A miniature sensor for electrical field measurements in dusty planetary atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Renno, N O; Rogacki, S [Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor (United States); Kok, J F [Applied Physics Program, University of Michigan, Ann Arbor, MI (United States); Kirkham, H [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States)], E-mail: renno@alum.mit.edu

    2008-12-01

    Dusty phenomena such as regular wind-blown dust, dust storms, and dust devils are the most important, currently active, geological processes on Mars. Electric fields larger than 100 kV/m have been measured in terrestrial dusty phenomena. Theoretical calculations predict that, close to the surface, the bulk electric fields in martian dusty phenomena reach the breakdown value of the isolating properties of thin martian air of about a few 10 kV/m. The fact that martian dusty phenomena are electrically active has important implications for dust lifting and atmospheric chemistry. Electric field sensors are usually grounded and distort the electric fields in their vicinity. Grounded sensors also produce large errors when subject to ion currents or impacts from clouds of charged particles. Moreover, they are incapable of providing information about the direction of the electric field, an important quantity. Finally, typical sensors with more than 10 cm of diameter are not capable of measuring electric fields at distances as small as a few cm from the surface. Measurements this close to the surface are necessary for studies of the effects of electric fields on dust lifting. To overcome these shortcomings, we developed the miniature electric-field sensor described in this article.

  15. Improving the energy indicators of thyristor electric drive with asynchronous short-circuited motor of a deep pump unit by negative feedback

    Energy Technology Data Exchange (ETDEWEB)

    Aliyev, E.S.

    1983-01-01

    At the department of electric drive and automation of industrial units of the M. Azizbekov Azerbaijan Institute of Petrochemistry a system was developed for automated thyristor electric drive of alternating current with asynchronous short-circuited electric motor for smooth regulation of the output of a deep-pump unit, which at the same time makes it possible to improve the energy efficiency of the electric drive of the pumping unit with quasi steady-state mode of changing the voltage on the motor stator according to the load by using negative feedback for the rotation frequency of the motor.

  16. Thermoelectric cooling of microelectronic circuits and waste heat electrical power generation in a desktop personal computer

    International Nuclear Information System (INIS)

    Thermoelectric cooling and micro-power generation from waste heat within a standard desktop computer has been demonstrated. A thermoelectric test system has been designed and constructed, with typical test results presented for thermoelectric cooling and micro-power generation when the computer is executing a number of different applications. A thermoelectric module, operating as a heat pump, can lower the operating temperature of the computer's microprocessor and graphics processor to temperatures below ambient conditions. A small amount of electrical power, typically in the micro-watt or milli-watt range, can be generated by a thermoelectric module attached to the outside of the computer's standard heat sink assembly, when a secondary heat sink is attached to the other side of the thermoelectric module. Maximum electrical power can be generated by the thermoelectric module when a water cooled heat sink is used as the secondary heat sink, as this produces the greatest temperature difference between both sides of the module.

  17. Time domain simulation of Li-ion batteries using non-integer order equivalent electrical circuit

    Science.gov (United States)

    Riu, D.; Montaru, M.; Bultel, Y.

    2013-06-01

    For electric vehicle (EV) or hybrid EV (HEV) development and integration of renewables in electrical networks, battery monitoring systems have to be more and more precise to take into account the state-of-charge and the dynamic behavior of the battery. Some non-integer order models of electrochemical batteries have been proposed in literacy with a good accuracy and a low number of parameters in the frequential domain. Nevertheless, time simulation of such models required to approximate this non-integer order system by an equivalent high integer order model. An adapted algorithm is then proposed in this article to simulate the non-integer order model without any approximation, thanks to the construction of a 3-order generalized state-space system. This algorithm is applied and validated on a 2.3 A.h Li-ion battery.

  18. Work in progress-role of learning strategies in electrical circuits and analog electronics courses

    OpenAIRE

    Ramírez Echeverry, Jhon Jairo; Olarte Dussan, Fredy Andres; García Carrillo, Àgueda

    2014-01-01

    This work-in-progress describes a study intended to determine whether self-regulated learning strategies influence the academic performance of students from the Department of Electrical and Electronics Engineering at Universidad Nacional de Colombia. This research was conducted with 396 students in two terms, who were surveyed about their use of learning strategies using the CEAM II psychometric tool. Later, it was analyzed whether a significant correlation exists between the scores obtained ...

  19. Effects of the March 2015 solar eclipse on near-surface atmospheric electricity.

    Science.gov (United States)

    Bennett, A J

    2016-09-28

    Measurements of atmospheric electrical and standard meteorological parameters were made at coastal and inland sites in southern England during the 20 March 2015 partial solar eclipse. Clear evidence of a reduction in air temperature resulting from the eclipse was found at both locations, despite one of them being overcast during the entire eclipse. The reduction in temperature was expected to affect the near-surface electric field (potential gradient (PG)) through a reduction in turbulent transfer of space charge. No such effect could be unambiguously confirmed, however, with variability in PG and air-Earth current during the eclipse being comparable to pre- and post-eclipse conditions. The already low solar radiation for this latitude, season and time of day was likely to have contributed to the reduced effect of the eclipse on atmospheric electricity through boundary layer stability. The absence of a reduction in mean PG shortly after time of maximum solar obscuration, as observed during eclipses at lower geomagnetic latitude, implied that there was no significant change in atmospheric ionization from cosmic rays above background variability. This finding was suggested to be due to the relative importance of cosmic rays of solar and galactic origin at geomagnetic mid-latitudes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. PMID:27550771

  20. Circular polarization of radio emission from air showers probes atmospheric electric fields in thunderclouds.

    Science.gov (United States)

    Gia Trinh, Thi Ngoc; Scholten, Olaf; Buitink, Stijn; Corstanje, Arthur; Ebert, Ute; Enriquez, Emilio; Falcke, Heino; Horandel, Jörg R.; Nelles, Anna; Schellart, Pim; Rachen, Jorg; Rossetto, Laura; Rutjes, Casper; ter Veen, Sander; Thoudam, Satyendra

    2016-04-01

    When a high-energy cosmic-ray particle enters the upper layer of the atmosphere, it generates many secondary high-energy particles and forms a cosmic-ray-induced air shower. In the leading plasma of this shower electric currents are induced that emit electromagnetic radiation. These radio waves can be detected with LOw-Frequency ARray (LOFAR) radio telescope. Events have been collected under fair-weather conditions as well as under atmospheric conditions where thunderstorms occur. For the events under the fair weather conditions the emission process is well understood by present models. For the events measured under the thunderstorm conditions, we observe a large fraction of the circular polarization near the core of the shower which is not shown in the events under the fair-weather conditions. This can be explained by the change of direction of the atmospheric electric fields with altitude. Therefore, measuring the circular polarization of radio emission from cosmic ray extensive air showers during the thunderstorm conditions helps to have a better understanding about the structure of atmospheric electric fields in the thunderclouds.

  1. IE Information Notice No. 85-93: Westinghouse Type DS circuit breakers, potential failure of electric closing feature because of broken spring release latch lever

    International Nuclear Information System (INIS)

    On April 14, 1985, the Westinghouse Nuclear Services Integration Division (NSID) issued Technical Bulletin No. NSID-TB-85-17 advising their customers of a potential malfunction in Westinghouse Type DS Class 1E circuit breakers because of broken spring release latch levers. These electrically operated type DS breakers will not close electrically when the spring release latch lever has been broken off. Twenty-five broken levers have been reported and evaluated. This evaluation shows concentrations of incidents traceable to manufacturing in the following periods of time: early 1975, April 1976, and early 1978. This circuit breaker failure, as discussed, adversely affects the safety function (closing on demand) when the circuit breaker is used in the Engineered Safety Features Systems. However, this failure mode will not affect the safety trip function when it is used in the reactor protection system

  2. 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.

  3. Military Curricula for Vocational & Technical Education. Basic Electricity and Electronics. CANTRAC A-100-0010. Module 34: Linear Integrated Circuits. Study Booklet.

    Science.gov (United States)

    Chief of Naval Education and Training Support, Pensacola, FL.

    This individualized learning module on linear integrated circuits is one in a series of modules for a course in basic electricity and electronics. The course is one of a number of military-developed curriculum packages selected for adaptation to vocational instructional and curriculum development in a civilian setting. Two lessons are included in…

  4. Peculiarities of electric and magnetic tipper variations caused by meteorological disturbances in the atmosphere

    Science.gov (United States)

    Adushkin, V. V.; Spivak, A. A.

    2016-01-01

    We present the results of the analysis of experimental data of synchronous observations of variations in the electric and magnetic fields as well as acoustic oscillations in the surface zone of the Earth compared with variations in the meteorological parameters. We demonstrate the synchronous variations in these fields and atmospheric parameters. We revealed, for the first time, not only synchronous but also advancing manifestations of the geomagnetic field perturbations. We introduce a new parameter: the inverse magnetic tipper whose variations during atmospheric perturbations are clearly manifested compared with the variations in the magnetic tipper.

  5. The Effect of the Disturbed Electric Field of the Atmosphere on Cosmic Rays 2. Hard Component

    CERN Document Server

    Khaerdinov, S; Petkov, B

    2003-01-01

    The results of studying the correlation of the hard component of cosmic rays with the electric field of the atmosphere during thunderstorm periods are presented. The data at several energy thresholds are examined using the liquid scintillators of the the Baksan air shower array and the plastic scintillators of the muon detector with a threshold of 1 GeV. It is demonstrated that the quadratic effect (changing intensity of muons at the electric field of any sign) is the most pronounced for soft muons.

  6. The Effect of the Disturbed Electric Field of the Atmosphere on Cosmic Rays 1. Soft Component

    CERN Document Server

    Khaerdinov, S; Petkov, B; Surovetsky, Yu

    2003-01-01

    The results of studying the correlation of the soft component of cosmic rays (10-30 MeV) with the electric field of the atmosphere during thunderstorm periods are presented. The uncovered scintillators of the Baksan air shower array are used as detectors of the soft component, and the data for three seasons (2000--2002) are included into the analysis. It is shown that both linear and quadratic effects of the electric field are present in the soft component intensity. In this case, the linear term is rather stable and independent of the selection criteria, while the quadratic term is subject to significant variations.

  7. Theoretical computation for non-equilibrium air plasma electrical conductivity at atmospheric pressure

    International Nuclear Information System (INIS)

    Based on the Chapman-Enskog theory, we calculate the electrical conductivity of non-equilibrium air plasma in the two-temperature model. We consider different degrees of non-equilibrium, which is defined by the ratio of electronic temperature to heavy particles temperature. The method of computing the composition of air plasma is demonstrated. After calculating the electrical conductivity from electron temperature 1000 K to 15000 K, the present result is compared with Murphy's study for equilibrium case. All the calculation is completed at atmospheric pressure. The present results may have potential applications in numerical calculation of non-equilibrium air plasma. (authors)

  8. Design and construction of prototype transversely excited atmospheric (TEA nitrogen laser energized by a high voltage electrical discharge

    Directory of Open Access Journals (Sweden)

    Mukhtar Hussain

    2015-07-01

    Full Text Available The present study reports design and construction, of a prototype of Transversely Excited Atmospheric (TEA nitrogen laser, and a high voltage power supply to excite N2 gas in air, while air is used as an active lasing medium. A Blumlein line discharge circuit is used for operation of this laser. The high voltage is generated by a fly back transformer based power supply varying from 10 kV to 20 kV. The wavelength (337.1 nm of TEA nitrogen laser is measured employing a standard commercial spectrometer and the laser output energy of 300 μJ is measured from the constructed system. Different parameters such as beam profile, laser output spectrum, laser efficiency, and variation of E/P (Electrical field/Pressure value with respect to input voltage and electrodes separations are studied in order to optimize the overall operational efficiency of present nitrogen laser. The analysis of the high voltage prototype appeared in this designed source has also been made and described in this paper.

  9. Effect of annealing atmosphere on phase formation and electrical characteristics of bismuth ferrite thin films

    International Nuclear Information System (INIS)

    Bismuth ferrite thin films were deposited on Pt/Ti/SiO2/Si substrates by a soft chemical method and spin-coating technique. The effect of annealing atmosphere (air, N2 and O2) on the structure and electrical properties of the films are reported. X-ray diffraction analysis reveals that the film annealed in air atmosphere is a single-phase perovskite structure. The films annealed in air showed better crystallinity and the presence of a single BFO phase leading to lower leakage current density and superior ferroelectric hysteresis loops at room temperature. In this way, we reveal that BFO film crystallized in air atmosphere by the soft chemical method can be useful for practical applications, including nonvolatile digital memories, spintronics and data-storage media.

  10. Ambipolar Electric Field, Photoelectrons, and Their Role in Atmospheric Escape From Hot Jupiters

    Science.gov (United States)

    Cohen, O.; Glocer, A.

    2012-01-01

    Atmospheric mass loss from Hot Jupiters can be large due to the close proximity of these planets to their host star and the strong radiation the planetary atmosphere receives. On Earth, a major contribution to the acceleration of atmospheric ions comes from the vertical separation of ions and electrons, and the generation of the ambipolar electric field. This process, known as the "polar wind," is responsible for the transport of ionospheric constituents to Earth's magnetosphere, where they are well observed. The polar wind can also be enhanced by a relatively small fraction of super-thermal electrons (photoelectrons) generated by photoionization.We formulate a simplified calculation of the effect of the ambipolar electric field and the photoelectrons on the ion scale height in a generalized manner. We find that the ion scale height can be increased by a factor of 2-15 due to the polar wind effects. We also estimate a lower limit of an order of magnitude increase of the ion density and the atmospheric mass-loss rate when polar wind effects are included.

  11. AMBIPOLAR ELECTRIC FIELD, PHOTOELECTRONS, AND THEIR ROLE IN ATMOSPHERIC ESCAPE FROM HOT JUPITERS

    International Nuclear Information System (INIS)

    Atmospheric mass loss from Hot Jupiters can be large due to the close proximity of these planets to their host star and the strong radiation the planetary atmosphere receives. On Earth, a major contribution to the acceleration of atmospheric ions comes from the vertical separation of ions and electrons, and the generation of the ambipolar electric field. This process, known as the 'polar wind', is responsible for the transport of ionospheric constituents to Earth's magnetosphere, where they are well observed. The polar wind can also be enhanced by a relatively small fraction of super-thermal electrons (photoelectrons) generated by photoionization. We formulate a simplified calculation of the effect of the ambipolar electric field and the photoelectrons on the ion scale height in a generalized manner. We find that the ion scale height can be increased by a factor of 2-15 due to the polar wind effects. We also estimate a lower limit of an order of magnitude increase of the ion density and the atmospheric mass-loss rate when polar wind effects are included.

  12. Atmospheric electrification in the Solar System

    CERN Document Server

    Aplin, K

    2005-01-01

    Atmospheric electrification is not a purely terrestrial phenomenon: all Solar System planetary atmospheres become slightly electrified by cosmic ray ionisation. There is evidence for lightning on Jupiter, Saturn, Uranus and Neptune, and it appears likely to exist on Mars, Venus and Titan. Atmospheric electricity has controversially been implicated in climate on Earth; here, a comparative approach is employed to review the role of electrification in the atmospheres of other planets and their moons. This paper reviews planetary atmospheric electricity including ionisation and ion-aerosol interactions. The conditions necessary for a global electric circuit, and the likelihood of meeting these conditions in other planetary atmospheres are briefly discussed. Atmospheric electrification could be important throughout the Solar System, particularly at the outer planets which receive little solar radiation, increasing the significance of electrical forces. Nucleation onto atmospheric ions has been predicted to affect ...

  13. Basic of electric engineering

    International Nuclear Information System (INIS)

    This book deals with what is electricity?, how does electricity generate?, how does electricity generate by friction, heat, light, chemistry reaction and magnetism?, what is direct current?, magnetic filed, how is electric current measured? electromotive force, voltage, resistance circuit, direct current circuit, power, direct parallel circuit, kerchief's laws, current circuit instrument, alternating current circuit, inductance of current circuit, what is current?, Ohm's law what adjusts power flow? power of induction circuit, capacitance of current circuit, capacitor and reactance of capacitive.

  14. Sub-nanosecond dynamics of atmospheric air discharge under highly inhomogeneous and transient electric field

    Science.gov (United States)

    Tardiveau, Pierre; Magne, Lionel; Pasquiers, Stephane; Jeanney, Pascal; Bournonville, Blandine

    2015-09-01

    The effects of the application of extreme overvoltages (>500%) in air gaps over less than a few nanoseconds bring us to reconsider the classical physics of streamer used to describe air discharges at atmospheric pressure. Non equilibrium discharges created by extremely transient and intense electric fields in standard conditions of pressure and temperature exhibit unusual diffuse and large structure. In point-to-plane electrode configurations, a plasma cloud is observed which properties depend on voltage pulses features (amplitude, rise time, length, and frequency) and electrodes properties (material, shape, and gap length). Our parametric experimental study is based on fast electrical characterization and sub-nanosecond imaging and shows the different stages of propagation of the cloud. This work details the conditions to maximize the cloud size without moving towards a multi-channel streamer regime. Based on the analysis and the Abel transform processing of the emission of excited states of nitrogen from the discharge, a focus is made on the structuration of the plasma cloud while it is propagating. It shows how much, according to the experimental conditions, the external electric field can be screened by the plasma and, inversely, how deep and how long a high electric field can be sustained in the gap, that is challenging for pulsed atmospheric plasmas applications. This work benefits from the financial support of the National Agency of Research within the framework of the project ANR-13-BS09-0014.

  15. Electric fields, electron precipitation, and VLF radiation during a simultaneous magnetospheric substorm and atmospheric thunderstorm

    International Nuclear Information System (INIS)

    A balloon payload instrumented with a double-probe electric field detector and an X ray scintillation counter was launched from Roberval, Quebec, Canada (L=4.1) at 0828 UT (0328 LT) on July 9, 1975. A magnetospheric substorm was observed locally between 0815 and 1100 UT, which produced a maximum ΔB of approx.500 nT at approx.0930 UT. A single-cell atmospheric thunderstorm developed northeast of Roberval beginning around 0925 UT which was most intense from approx.1000 to 1035 UT. Detailed study of the electrical properties of the thunderstorm, the X ray precipitation data, and VLF spheric data leads to three conclusions. First, the electrical coupling from the thunderstorm to the magnetosphere increases with frequency from dc to the VLF; for the observed storm the amplitude at the ionosphere of thunderstorm produced electric fields was not significant at frequencies below 0.1 Hz. Second, the atmospheric conductivity above the thunderstorm was observed to be about one-half the fair weather value prior to 1000 UT; decreased to about one-quarter the fair weather value at about 1000 UT; and remained depressed after the end of the thunderstorm. This result was contrary to that expected on the basis of previous work and is one which merits considerably more investigation. Third, the data show a high probability that half-hop whistlers initiated by sferics from the thunderstorm triggered energetic electron precipitation from the magnetosphere

  16. Modeling of a distributed constant electric circuit considering contact resistance and coupling loss analyses for cable twisted at multiple stages

    International Nuclear Information System (INIS)

    AC losses in multi-strand superconducting cables, utilized in large-scale applications such as fusion machines, are governed by the contact resistance between strands. Especially, in cable twisted at multiple-stages, a variety of magnetic field diffusion time constants exist and these correspond to the quantity of inter-strand coupling loss in each cabling stage. The rate of magnetic field change is less than several T/s in an average fusion machine. Under this condition, the magnetic field penetrates the cable well and the coupling current circuit with the larger time constant causes larger AC loss. Here, the time constant is equal to the leakage inductance divided by the resistance along the coupling current loop. Therefore, by evaluating the coupling current in the larger loop, which consists of a higher twisting stage (e.g., usually the final cabling stage), the loss in the entire cable can be determined. The leakage inductance between sub-cables can be estimated by considering the electrical centers. On the other hand, inter-sub-cable contact resistance was not previously evaluated due to its complexity. In this study, we established an inter-sub-cable contact resistance model that allows the AC loss in cable with multiple twisting stages to be evaluated numerically. The modeling of contact resistance between sub-cables is discussed in detail. (author)

  17. An Examination of AC/HVDC Power Circuits for Interconnecting Bulk Wind Generation with the Electric Grid

    Directory of Open Access Journals (Sweden)

    Daniel Ludois

    2010-06-01

    Full Text Available The application of high voltage dc (HVDC transmission for integrating large scale and/or off-shore wind generation systems with the electric grid is attractive in comparison to extra high voltage (EHV ac transmission due to a variety of reasons. While the technology of classical current sourced converters (CSC using thyristors is well established for realization of large HVDC systems, the technology of voltage sourced converters (VSC is emerging to be an alternative approach, particularly suitable for multi-terminal interconnections. More recently, a more modular scheme that may be termed ‘bridge of bridge’ converters (BoBC has been introduced to realize HVDC systems. While all these three approaches are functionally capable of realizing HVDC systems, the converter power circuit design trade-offs between these alternatives are not readily apparent. This paper presents an examination of these topologies from the point of view of power semiconductor requirements, reactive component requirements, operating losses, fault tolerance, multi-terminal operation, modularity, complexity, etc. Detailed analytical models will be used along with a benchmark application to develop a comparative evaluation of the alternatives that maybe used by wind energy/bulk transmission developers for performing engineering trade-off studies.

  18. Twelve years of continuous measurements of atmospheric electrical activity in Mexico's Tropical highland

    Energy Technology Data Exchange (ETDEWEB)

    Troncoso Lozada, O. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico (UNAM), Mexico, D.F. (Mexico)

    2004-04-01

    Atmospheric electric activity measurements have been recorded continuously by a punctual lightning system at a tropical highland observatory from 1988 onwards, and were analyzed to obtain lightning statistical confident results for thunderstorms occurrence on the leeward side of the southern mountain ridge of Mexico's Valley. Shown, as examples, are individual profiles of the atmospheric electrical activity, associated with severe storms. The results make clear that the fastest possible sequence of electrical measurements is required to obtain significant and applications oriented data in connection with a whole series of thunderstorms taking into account the mean time variation of the atmospheric electricity measurements at an altitude of 2270 m a.s.l. The seasonal variation indicates that the lightning flash peak currents were found to be larger in summer with less than 10% occurring in the autumn and winter. With rainfall data from a network of 66 stations, we obtained a significant correlation with the lightning frequency. Special attention was undertaken concerning the question of the atmospheric electrical activity and climate at Valley of Mexico. [Spanish] Se midieron ininterrumpidamente las variaciones de la actividad electrica en la atmosfera, de enero de 1988 a diciembre de 1999, en un observatorio de altura (2,250 m s.n.m.), y se analizaron para obtener resultados estadisticos confiables con relacion a la ocurrencia de tormentas en la region sur del Valle de Mexico. Como ejemplos, se muestran los perfiles individuales de la actividad electrica atmosferica asociada con tormentas severas. Los resultados dejan claro que se requiere de la secuencia de medidas electricas lo mas rapida posible para obtener datos significativos y aplicables en relacion con una serie completa de tormentas, considerando la media del tiempo de variacion de las mediciones de la actividad electrica atmosferica a una altitud de 2,270 m s.n.m. La validacion estacional indica que

  19. Simulation of radio emission from air showers in atmospheric electric fields

    CERN Document Server

    Buitink, S; Falcke, H; Kuijpers, J

    2010-01-01

    We study the effect of atmospheric electric fields on the radio pulse emitted by cosmic ray air showers. Under fair weather conditions the dominant part of the radio emission is driven by the geomagnetic field. When the shower charges are accelerated and deflected in an electric field additional radiation is emitted. We simulate this effect with the Monte Carlo code REAS2, using CORSIKA-simulated showers as input. In both codes a routine has been implemented that treats the effect of the electric field on the shower particles. We find that the radio pulse is significantly altered in background fields of the order of ~100 V/cm and higher. Practically, this means that air showers passing through thunderstorms emit radio pulses that are not a reliable measure for the shower energy. Under other weather circumstances significant electric field effects are expected to occur rarely, but nimbostratus clouds can harbor fields that are large enough. In general, the contribution of the electric field to the radio pulse ...

  20. Optical and electrical characteristics of air dielectric barrier discharges in mode transition at atmospheric pressure

    International Nuclear Information System (INIS)

    Atmospheric pressure dielectric barrier discharges (DBDs) have a wide range of industrial applications, generally exhibiting either filamentary or diffuse (i.e. glow) discharges. The focus of this investigation is on the formation mechanisms of the discharge current pulse width, on the order of tens of microseconds, accompanied by a light source formation, which is called a light source (LS) mode in air DBDs at atmospheric pressure. From a macroscopic point of view, the characteristics of the discharge current in the LS mode are similar with those of the glow mode. The optical and electrical characteristics of air DBDs at atmospheric pressure are investigated in the transition from the filamentary mode to the LS mode by measuring the optical emission spectroscopy and electrical signals. It is shown that in the manual increasing voltage stage, the vibrational temperature almost never changes and the gas temperature, electron temperature, dielectric capacitance, gas voltage (Vg) and discharge power (P) increase with an increase in the applied voltage. In the automatic decreasing voltage stage, all of these parameters, except Vg and P, increase with a decrease in the voltage. But, when the voltage decreases to a minimum value corresponding to the LS mode, P reaches a maximum value. In this paper, the variations of these parameters are analyzed and discussed in detail. The formation of the LS mode originates from the secondary electrons. The formation mechanisms of the secondary electrons are also discussed. (paper)

  1. Long-Term Characterization of 6H-SiC Transistor Integrated Circuit Technology Operating at 500 C

    Science.gov (United States)

    Neudeck, Philip G.; Spry, David J.; Chen, Liang-Yu; Chang, Carl W.; Beheim, Glenn M.; Okojie, Robert S.; Evans, Laura J.; Meredith Roger D.; Ferrier, Terry L.; Krasowski, Michael J.; Prokop, Norman F.

    2008-01-01

    NASA has been developing very high temperature semiconductor integrated circuits for use in the hot sections of aircraft engines and for Venus exploration. This paper reports on long-term 500 C electrical operation of prototype 6H-SiC integrated circuits based on epitaxial 6H-SiC junction field effect transistors (JFETs). As of this writing, some devices have surpassed 4000 hours of continuous 500 C electrical operation in oxidizing air atmosphere with minimal change in relevant electrical parameters.

  2. Predicted electrical conductivity between 0 and 80 km in the Venusian atmosphere

    Science.gov (United States)

    Borucki, W. J.; Levin, Z.; Whitten, R. C.; Keesee, R. G.; Capone, L. A.; Toon, O. B.; Dubach, J.

    1982-01-01

    Calculations of the space charge, ion density, and conductivity in the Venus atmosphere were made. The presence of the cloud particles on Venus causes a profund reduction in the calculated values of the ion density and conductivity compared to the values that are obtained without consideration of the cloud particles. When the cloud particles are included in the calculations, the results for the ion density and conductivity are approximately the same as those of the terrestrial atmosphere at the same pressure-altitude. Because the particles span such a large range of sizes and are abundant over a substantial range of pressure, the space charge varies strongly with altitude and particle size. Differential settling of the particles is expected to produce weak electric fields in the clouds.

  3. Retrieval of global atmospheric electrical activity at a polluted urban site

    International Nuclear Information System (INIS)

    The atmospheric electrical Potential Gradient (PG) arises from global thunderstorm activity, but surface measurements of the atmospheric Potential Gradient (PG) are influenced by global thunderstorms and local aerosol concentration changes. The local aerosol change can be monitored independently, and in some cases the concentration changes are closely related to PG changes. For these circumstances, a general theory to remove the local aerosol influence on PG measurements has been developed. Continuous measurements of PG and aerosol mass concentration were made during 24-31 Dec, 2005 within an urban environment at Reading, UK. The average diurnal variation of PG showed a double diurnal cycle, with maxima in the early morning and evening hours. The aerosol concentration has similar double maxima. Removing the aerosol using from the PG and aerosol correlation returns a single diurnal cycle, suggestive of the more global PG diurnal cycle.

  4. 1D Modeling of a Bifacial Silicon Solar Cell under Frequency Modulation Monochromatic Illumination: Determination of the Equivalent Electrical Circuit Related to the Surface Recombination Velocity

    Directory of Open Access Journals (Sweden)

    H. Ly Diallo

    2012-06-01

    Full Text Available We present in this study the determination of the equivalent electrical circuits associated to the recombination velocities for a bifacial silicon solar cell under frequency modulation and monochromatic illumination. This determination is based on Bode and Nyquist diagrams that is the variations of the phase and the module of the back surface and intrinsic junction recombination velocities. Their dependence on illumination wavelength is also shown.

  5. 1D Modeling of a Bifacial Silicon Solar Cell under Frequency Modulation Monochromatic Illumination: Determination of the Equivalent Electrical Circuit Related to the Surface Recombination Velocity

    OpenAIRE

    H. Ly Diallo; Wade, M.; I. Ly; NDiaye, M; B. Dieng O.H. Lemrabott; A.S. Maïga; G. Sissoko

    2012-01-01

    We present in this study the determination of the equivalent electrical circuits associated to the recombination velocities for a bifacial silicon solar cell under frequency modulation and monochromatic illumination. This determination is based on Bode and Nyquist diagrams that is the variations of the phase and the module of the back surface and intrinsic junction recombination velocities. Their dependence on illumination wavelength is also shown.

  6. Electrical properties of metallic SmS phase stable at atmospheric pressure

    International Nuclear Information System (INIS)

    The electric conductivity, Hall effect and magnetoresistance of SmS metal phase, stable at atmospheric pressu re, produced by transformation of a thin polycrystalline semiconductor film to a metal state over the whole thickness with the use of mechanical polishing were investigated. The temperature of measurements ranged within 0.45 to 260 K. It is established from the behaviour of the Hall constant and Hall mobility that a metal film corresponds to a high pressure phase of SmS metal monocrystals. The concentration of conductivity electrons in the film at helium temperatures corresponds to 2.80 samarium ion valency

  7. Atmospheric electric field measurements in urban environment and the pollutant aerosol weekly dependence

    OpenAIRE

    Silva, Hugo; Conceição, Ricardo; Melgão, Marta; Nicoll, Keri; Mendes, P. B.; M. Tlemçani; Reis, A. Heitor; Harrison, R. G.

    2014-01-01

    The weekly dependence of pollutant aerosols in the urban environment of Lisbon (Portugal) is inferred from the records of atmospheric electric field at Portela meteorological station (38°47′N, 9°08′W). Measurements were made with a Bendorf electrograph. The data set exists from 1955 to 1990, but due to the contaminating effect of the radioactive fallout during 1960 and 1970s, only the period between 1980 and 1990 is considered here. Using a relative difference method a weekly d...

  8. Relationship Between Aerosol Number Size Distribution and Atmospheric Electric Potential Gradient in an Urban Area

    Science.gov (United States)

    Wright, Matthew; Matthews, James; Bacak, Asan; Silva, Hugo; Priestley, Michael; Percival, Carl; Shallcross, Dudley

    2016-04-01

    Small ions are created in the atmosphere by ground based radioactive decay and solar and cosmic radiation ionising the air. The ionosphere is maintained at a high potential relative to the Earth due to global thunderstorm activity, a current from the ionosphere transfers charge back to the ground through the weakly ionised atmosphere. A potential gradient (PG) exists between the ionosphere and the ground that can be measured in fair weather using devices such as an electric field mill. PG is inversely-proportional to the conductivity of the air and therefore to the number of ions of a given electrical mobility; a reduction of air ions will cause an increase of PG. Aerosols in the atmosphere act as a sink of air ions with an attachment rate dependent on aerosol size distribution and ion mobility. These relationships have been used to infer high particulate, and hence pollution, levels in historic datasets of atmospheric PG. A measurement campaign was undertaken in Manchester, UK for three weeks in July and August where atmospheric PG was measured with an electric field mill (JCI131, JCI Chilworth) on a second floor balcony, aerosol size distribution measured with a scanning mobility particle sizer (SMPS, TSI3936), aerosol concentration measured with a condensation particle counter (CPC, Grimm 5.403) and local meteorological measurements taken on a rooftop measurement site ~200 m away. Field mill and CPC data were taken at 1 s intervals and SMPS data in 2.5 minute cycles. Data were excluded for one hour either side of rainfall as rainclouds and droplets can carry significant charge which would affect PG. A quantity relating to the attachment of ions to aerosol (Ion Sink) was derived from the effective attachment coefficient of the aerosols. Further measurements with the field mill and CPC were taken at the same location in November 2015 when bonfire events would be expected to increase aerosol concentrations. During the summer measurements, particle number count (PNC

  9. Asymmetric surface dielectric barrier discharge in air at atmospheric pressure: electrical properties and induced airflow characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pons, Jerome; Moreau, Eric; Touchard, Gerard [LEA, University of Poitiers/CNRS/ENSMA, Bd. Curie, Teleport 2, BP 30179, 86962 Futuroscope Cedex (France)

    2005-10-07

    The electrical properties of an asymmetric surface dielectric barrier discharge in atmospheric air have been investigated experimentally. The discharge is used for airflow production close to the dielectric surface, and the time-averaged flow velocity spatial profiles have been measured. Velocities of up to 3.5 m s{sup -1} at heights of 1-2 mm are reached when filamentary discharges with current peaks up to 20 mA are produced along the surface. In terms of powers, mechanical powers (output) of a few milliwatts are obtained for electrical powers (input) up to 10 W. Variation laws or behaviour with several discharge parameters (applied voltage waveform, distance between electrodes, dielectric thickness and permittivity) have been experimentally determined.

  10. Lithium Ion Batteries—Development of Advanced Electrical Equivalent Circuit Models for Nickel Manganese Cobalt Lithium-Ion

    Directory of Open Access Journals (Sweden)

    Alexandros Nikolian

    2016-05-01

    Full Text Available In this paper, advanced equivalent circuit models (ECMs were developed to model large format and high energy nickel manganese cobalt (NMC lithium-ion 20 Ah battery cells. Different temperatures conditions, cell characterization test (Normal and Advanced Tests, ECM topologies (1st and 2nd Order Thévenin model, state of charge (SoC estimation techniques (Coulomb counting and extended Kalman filtering and validation profiles (dynamic discharge pulse test (DDPT and world harmonized light vehicle profiles have been incorporated in the analysis. A concise state-of-the-art of different lithium-ion battery models existing in the academia and industry is presented providing information about model classification and information about electrical models. Moreover, an overview of the different steps and information needed to be able to create an ECM model is provided. A comparison between begin of life (BoL and aged (95%, 90% state of health ECM parameters (internal resistance (Ro, polarization resistance (Rp, activation resistance (Rp2 and time constants (τ is presented. By comparing the BoL to the aged parameters an overview of the behavior of the parameters is introduced and provides the appropriate platform for future research in electrical modeling of battery cells covering the ageing aspect. Based on the BoL parameters 1st and 2nd order models were developed for a range of temperatures (15 °C, 25 °C, 35 °C, 45 °C. The highest impact to the accuracy of the model (validation results is the temperature condition that the model was developed. The 1st and 2nd order Thévenin models and the change from normal to advanced characterization datasets, while they affect the accuracy of the model they mostly help in dealing with high and low SoC linearity problems. The 2nd order Thévenin model with advanced characterization parameters and extended Kalman filtering SoC estimation technique is the most efficient and dynamically correct ECM model developed.

  11. Measurements of atmospheric electrical parameters and ELF electromagnetic emissions during a meteorological balloon flight.

    Science.gov (United States)

    Benda, Robert; Dujany, Matthieu; Berthomieu, Roland; Boissier, Mathilde; Bruneel, Pierre; Fischer, Lucie; Focillon, William; Gullo, Robin; Hubert, Valentin; Lafforgue, Gaétan; Loe-Mie, Marichka; Messager, Adrien; Roy, Felix; Auvray, Gérard; Bertrand, Fabrice; Coulomb, Romain; Deprez, Gregoire; Berthelier, Jean-Jacques

    2016-04-01

    Measurements of electric field and atmospheric conductivity were performed onboard a small payload flown under a meteorological balloon during a fair weather period. This experiment is part of a project to study thunderstorms and TLE organized in the frame of the engineering cursus at Ecole Polytechnique. The payload is equipped with 4 electrodes to measure the 3 components of the DC and AC electric fields up to 3.2 kHz. Dedicated sequences of operation, when one electrode is operated in the relaxation mode, have been used to determine the positive and negative electrical conductivities. Altitude profiles of the DC vertical electric field and conductivities in agreement with expected fair weather parameters were obtained from ~ 3.5 to ~ 13 km before the failure of a battery. At an altitude of ~ 9 km slight disturbances in the electric field suggest the traversal of thin clouds with disturbed electrical characteristics. Schumann resonances were observed up to the fifth harmonics at levels that are typical of a quiet period over Europe with most thunderstorms located over remote longitudinal sectors. EM waves due the power lines at 50Hz are detected during the whole measuring period and their altitude and horizontal variations will be presented as a function of the position of the balloon over the ground power network. A surprising and interesting observation was made of a Russian transmitter at 82 Hz located in Murmansk region and used for sub-marine communications. We shall present an initial analysis of the amplitude and polarization of the corresponding signal.

  12. Electric field development in γ-mode radiofrequency atmospheric pressure glow discharge in helium

    Science.gov (United States)

    Navrátil, Zdeněk; Josepson, Raavo; Cvetanović, Nikola; Obradović, Bratislav; Dvořák, Pavel

    2016-06-01

    Time development of electric field strength during radio-frequency sheath formation was measured using Stark polarization spectroscopy in a helium γ-mode radio-frequency (RF, 13.56 MHz) atmospheric pressure glow discharge at high current density (3 A cm-2). A method of time-correlated single photon counting was applied to record the temporal development of spectral profile of He I 492.2 nm line with a sub-nanosecond temporal resolution. By fitting the measured profile of the line with a combination of pseudo-Voigt profiles for forbidden (2 1P-4 1F) and allowed (2 1P-4 1D) helium lines, instantaneous electric fields up to 32 kV cm-1 were measured in the RF sheath. The measured electric field is in agreement with the spatially averaged value of 40 kV cm-1 estimated from homogeneous charge density RF sheath model. The observed rectangular waveform of the electric field time development is attributed to increased sheath conductivity by the strong electron avalanches occurring in the γ-mode sheath at high current densities.

  13. Automatic System for the D.C. High Voltage Qualification of the Superconducting Electrical Circuits of the LHC Machine

    CERN Document Server

    Bozzini, D; Russenschuck, Stephan; Bednarek, M; Jurkiewicz, P; Kotarba, A; Ludwin, J; Olek, S

    2008-01-01

    A d.c. high voltage test system has been developed to verify automatically the insulation resistance of the powering circuits of the LHC. In the most complex case, up to 72 circuits share the same volume inside cryogenic lines. Each circuit can have an insulation fault versus any other circuit or versus ground. The system is able to connect up to 80 circuits and apply a voltage up to 2 kV D.C. The leakage current flowing through each circuit is measured within a range of 1 nA to 1.6 mA. The matrix of measurements allows characterizing the paths taken by the currents and locating weak points of the insulation between circuits. The system is composed of a D.C. voltage source and a data acquisition card. The card is able to measure with precision currents and voltages and to drive up to 5 high voltage switching modules offering 16 channels each. A LabVIEW application controls the system for an automatic and safe operation. This paper describes the hardware and software design, the testing methodology and the res...

  14. Atmospheric electric field measurements in urban environment and the pollutant aerosol weekly dependence

    International Nuclear Information System (INIS)

    The weekly dependence of pollutant aerosols in the urban environment of Lisbon (Portugal) is inferred from the records of atmospheric electric field at Portela meteorological station (38°47′N, 9°08′W). Measurements were made with a Bendorf electrograph. The data set exists from 1955 to 1990, but due to the contaminating effect of the radioactive fallout during 1960 and 1970s, only the period between 1980 and 1990 is considered here. Using a relative difference method a weekly dependence of the atmospheric electric field is found in these records, which shows an increasing trend between 1980 and 1990. This is consistent with a growth of population in the Lisbon metropolitan area and consequently urban activity, mainly traffic. Complementarily, using a Lomb–Scargle periodogram technique the presence of a daily and weekly cycle is also found. Moreover, to follow the evolution of theses cycles, in the period considered, a simple representation in a colour surface plot representation of the annual periodograms is presented. Further, a noise analysis of the periodograms is made, which validates the results found. Two datasets were considered: all days in the period, and fair-weather days only. (letter)

  15. Application of Fast Vacuum Circuit Breaker in Electric System%快速真空断路器在电力系统中的应用

    Institute of Scientific and Technical Information of China (English)

    艾绍贵; 马奎; 吴旭涛; 孙丽琼

    2016-01-01

    介绍了涡流驱动型快速真空断路器的原理,分析了目前配网消弧消谐、故障选线及触电防护、电网短路电流限制、串联补偿及变压器直流偏磁抑制等技术的现状和存在的问题。根据快速真空断路器特点,提出了解决相关技术问题的方法,阐述了相关装置的结构、试验及应用情况,并对快速真空断路器在电力系统中的应用进行了展望。%Introduction was made to the principle of eddy current forced fast vacuum circuit breaker. Analysis was made to the technolo-gies used and problems existing including arc and resonance elimination, fault line selection and electric shock protection, grid short-circuit current limitation, series compensation and transformer direct current magnetic bias suppression etc technologies in distribution network at present. According to the characteristic of fast vacuum circuit breaker, the solution method of those problems was proposed. This paper ex-pounded the structure, experiment and application of the relevant device. The further application of the circuit breaker is prospected.

  16. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  17. Diurnal variations of 218Po, 214Pb, and 214Po and their effect on atmospheric electrical conductivity in the lower atmosphere at Mysore

    International Nuclear Information System (INIS)

    The short-lived radon daughters (218Po, 214Pb, 214Bi and 214Po) are natural tracers in the troposphere in particular near the ground surface. They are electrically charged particles and are chemically reactive. As soon as they are formed they get attached to the aerosol particles of the atmosphere. Their behaviour is similar to that of aerosols with respect to their growth, transport, removal processes in the atmosphere. The electrical conductivity of the atmosphere is mainly due to the presence of highly mobile (small) ions. Hence the electrical conductivity of air at near the surface of the earth mainly due to 222Rn, 218Po, 214Pb, 214Bi and 214Po concentrations, and depends on aerosol concentrations and meteorological parameters. The individual radon progeny concentrations (218Po, 214Pb, and 214Po) are measured using Air Flow meter. The concentration of radon in the atmospheric air is measured using Low Level Radon Detection System. The total energy released due to both radon and its progeny is computed in energy units (eV cm-3s-1) and is converted into ion-pair production rate (No. cm-3 s-1), 32 eV being the energy producing one-ion pair. The atmospheric electrical conductivity (both positive and negative) is measured using a Gerdien's apparatus with two identical tubes. The average values of 218Po, 214Pb, and 214Po are respectively 13.70, 1.45 and 1.92 Bq m-3 respectively. The average value of positive and negative electrical conductivity are 5.08 x 10-14U-1 m-1 and 4.67 x 10-14 U-1 m-1. The concentrations of radon, its progeny, and positive and negative conductivity show a similar kind of diurnal variations with maximum in the early morning hours and a minimum during day time. The activity is higher in winter than in summer and rainy season. (author)

  18. Helium atmospheric pressure plasma jets interacting with wet cells: delivery of electric fields

    Science.gov (United States)

    Norberg, Seth A.; Johnsen, Eric; Kushner, Mark J.

    2016-05-01

    The use of atmospheric pressure plasma jets (APPJs) in plasma medicine have produced encouraging results in wound treatment, surface sterilization, deactivation of bacteria, and treatment of cancer cells. It is known that many of the reactive oxygen and nitrogen species produced by the APPJ are critical to these processes. Other key components to treatment include the ion and photon fluxes, and the electric fields produced in cells by the ionization wave of the APPJ striking in the vicinity of the cells. These relationships are often complicated by the cells being covered by a thin liquid layer—wet cells. In this paper, results from a computational investigation of the interaction of APPJs with tissue beneath a liquid layer are discussed. The emphasis of this study is the delivery of electric fields by an APPJ sustained in He/O2  =  99.8/0.2 flowing into humid air to cells lying beneath water with thickness of 200 μm. The water layer represents the biological fluid typically covering tissue during treatment. Three voltages were analyzed—two that produce a plasma effluent that touches the surface of the water layer and one that does not touch. The effect of the liquid layer thickness, 50 μm to 1 mm, was also examined. Comparisons were made of the predicted intracellular electric fields to those thresholds used in the field of bioelectronics.

  19. A mechanistic study of initial atmospheric corrosion kinetics using electrical resistance sensors

    International Nuclear Information System (INIS)

    This paper describes a novel experimental approach to the study of atmospheric corrosion of iron and zinc, utilising electrical resistance sensors that are sensitive to corrosion losses of the order of one atomic monolayer. Using such devices, a mechanistic study of the initial stages in the atmospheric corrosion of iron and zinc was performed in a rectangular flow cell using controlled relative humidity (RH), temperature and gas flow rate. Additionally, the effects of SO2 contamination in the gas phase and prior NaCl contamination of the metal surface were studied. It was found that the initial corrosion kinetics of iron and zinc are, not unexpectedly, dominated by the development of surface corrosion product films, but that the growth kinetics vary with metal, humidity, etc. Specifically, in the presence of gas-phase SO2, activation energies and kinetic and chemical rate orders were consistent with control of the atmospheric corrosion process by solution-phase oxidation of sulphite-sulphate ion. For iron, this implies that the well-known sulphate-nest theory is inoperative at least during the early stages of atmospheric corrosion. In contrast, for chloride-contaminated zinc, the data were consistent with a rate-controlled diffusion of a species, probably water vapour or oxygen, through a thickening corrosion product film. Finally, the kinetic and chemical rate orders for corrosion of chloride-contaminated iron precluded a diffusion-controlled mechanism, but were consistent with a rate-controlling process involving some regeneration of chloride: e.g. as in metal-ion hydrolysis in a pit or similar localised corrosion events

  20. A New Approach for Modeling Darrieus-Type Vertical Axis Wind Turbine Rotors Using Electrical Equivalent Circuit Analogy: Basis of Theoretical Formulations and Model Development

    Directory of Open Access Journals (Sweden)

    Pierre Tchakoua

    2015-09-01

    Full Text Available Models are crucial in the engineering design process because they can be used for both the optimization of design parameters and the prediction of performance. Thus, models can significantly reduce design, development and optimization costs. This paper proposes a novel equivalent electrical model for Darrieus-type vertical axis wind turbines (DTVAWTs. The proposed model was built from the mechanical description given by the Paraschivoiu double-multiple streamtube model and is based on the analogy between mechanical and electrical circuits. This work addresses the physical concepts and theoretical formulations underpinning the development of the model. After highlighting the working principle of the DTVAWT, the step-by-step development of the model is presented. For assessment purposes, simulations of aerodynamic characteristics and those of corresponding electrical components are performed and compared.

  1. Processamento de placas de circuito impresso de equipamentos eletroeletrônicos de pequeno porte Processing of printed circuit boards of small electrical and electronic devices

    Directory of Open Access Journals (Sweden)

    Sérgio de Souza Henrique Júnior

    2013-01-01

    Full Text Available A hydrometallurgical process applicable to printed circuit boards of small electrical and electronic devices was developed. This involved three leaching steps (60 ºC, 2 h: 6 mol L-1 NaOH, 6 mol L-1 HCl and aqua regia. NaOH removed the resin and flame retardant that covered the circuit boards. HCl dissolved the most electropositive metals and a small amount of copper (~0.3 wt%. Aqua regia dissolved the noble metals. Silver precipitated as AgCl. Gold and platinum were quantitatively extracted with pure methyl-isobutylketone and Alamine 336 (10 % vol. in kerosene, respectively. Slow evaporation of the raffinate crystallized CuCl2.4H2O (89% yield.

  2. 一类自突触作用下神经元电路的设计和模拟∗%Simulation of electric activity of neuron by setting up a reliable neuronal circuit driven by electric autapse

    Institute of Scientific and Technical Information of China (English)

    任国栋; 武刚; 马军; 陈旸

    2015-01-01

    Transition of electric activity of neuron can be induced by electric autapse, and its action potential is much sensitive to the stimuli from the electric autapse. Generally, the effect of electric autapse on membrane potential of neuron is often described by using time-delayed feedback in closed loop. Based on Pspice software, a class of electric circuit is designed with the electric autapse being taken into consideration, and a time-delayed circuit is used to detect the adjusting action of electric autapse on the action potential. Results are found as follows: (1) The neuronal electric circuit can produce quiescent state, spiking, bursting state under an external force besides the electric autapse circuit. (2) The transition of electric activity occurs between four different atates (quiescent, spiking, bursting state) by imposing a time-varying forcing current; its potential mechanism is that the electric circuit is associated with the memory, and the neuron can give different types of response to the same external forcing current. (3)When a strong external force is imposed, the outputs can show different type of electric activities due to an electric autapse, that is to say, self-adaption of gain in the autapse is useful for the neuron and thus different type of electric activities occurs, whose potential mechanism may be due to the effective feedback in the loop;so it is helpful to understand the synaptic plasticity.%神经元在自突触作用下可以诱发各类放电活动的迁移,神经元动作电位对电自突触的响应比较敏感.通常用包含延迟因子和增益的反馈回路电流来刻画自突触对神经元动作电位的影响.基于Pspice软件,设计了包含自突触效应的神经元电路,用以延迟反馈电路来模拟电自突触对电位的调制作用.研究结果发现:1)在外界刺激和电自突触回路协同作用下,神经元电路输出信号可以呈现静息态,尖峰放电,簇放电状态.2)在时变增

  3. Printed circuit for ATLAS

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    A printed circuit board made by scientists in the ATLAS collaboration for the transition radiaton tracker (TRT). This will read data produced when a high energy particle crosses the boundary between two materials with different electrical properties.

  4. Lightning risk warnings based on atmospheric electric field measurements in Brazil

    Directory of Open Access Journals (Sweden)

    Marco Antonio da Silva Ferro*

    2011-09-01

    Full Text Available This paper presents a methodology that employs the electrostatic field variations caused by thundercloud formation or displacement to generate lightning warnings over a region of interest in Southeastern Brazil. These warnings can be used to prevent accidents during hazardous operations, such as the manufacturing, loading, and test of motor-rockets. In these cases, certain equipment may be moved into covered facilities and personnel are required to take shelter. It is also possible to avoid the threat of natural and triggered lightning to launches. The atmospheric electric field database, including the summer seasons of 2007/2008 and 2008/2009 (from November to February, and, for the same period and region, the cloud-to-ground lightning data provided by the Brazilian lightning detection network – BrasilDAT – were used in order to perform a comparative analysis between the lightning warnings and the cloud-to- ground lightning strikes that effectively occurred inside the area of concern. The analysis was done for three areas surrounding the sensor installation defined as circles with 5, 10 and 15 km of radius to determine the most effective detection range. For each area it was done using several critical electric field thresholds: +/- 0.5; +/- 0.8; +/- 0.9; +/- 1.0; +/- 1.2; and +/- 1.5 kV/m. As a result of the reduction of atmospheric electric field data provided by the sensor installed in area of concern and lightning provided by BrasilDAT, it was possible, for each of the areas of alert proposals, to obtain the following parameters: the number of effective alarms; the number of false alarms; and the number of failure to warning. From the analysis of these parameters, it was possible to conclude that, apparently, the most interesting critical electric field threshold to be used is the level of 0.9 kV/m in association with a distance range of 10 km around the point where the sensor is installed.

  5. Electric engineering introduction

    International Nuclear Information System (INIS)

    It is divided into nine chapters, which includes electricity theory such as structure of material and current, nature of electricity, static, magnetic force and magnetic attraction, attraction of current and a storage battery, electric circuit on a direct current circuit, single phase circuit and 3-phase current circuit electricity machine like DC generator, DC motor, alternator, electric transformer, single-phase induction motor, 3-phase induction motor, synchronous motor, synchro electric machine, semiconductor such as diode, transistor, FET, UJT, silicon symmetrical switch, electronic circuit like smoothing circuit and Bistable MV. circuit, automatic control, measurement of electricity, electric application and safety.

  6. Electric and spectroscopic properties of argon-hydrogen RF microplasma jets at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Souza-Correa, J A; Oliveira, C; Amorim, J [Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol-CTBE, Caixa Postal 6170, 13083-970, Campinas, Sao Paulo (Brazil); Gomes, M P, E-mail: jorge.correa@bioetanol.org.b, E-mail: carlos.filho@bioetanol.org.b, E-mail: gomesmp@ita.b, E-mail: jayr.amorim@bioetanol.org.b [Departamento de Fisica, Instituto Tecnologico de Aeronautica-ITA, Praca Marechal Eduardo Gomes 50, 12.228-900, Sao Jose dos Campos, Sao Paulo (Brazil)

    2010-10-06

    Microplasma jets of argon-hydrogen (Ar-H{sub 2}) gas mixture were generated by 144.0 MHz radio-frequency (RF) waves at powers of 5 W, 10 W, 20 W and 50 W. The experimental setup employed creates stable microplasmas at atmospheric pressure from 5.0 mm up to 20.0 mm visual glow lengths. We have determined the rms voltages, the rms electric currents and the power absorptions of these microplasma jets. By making use of optical spectroscopy, the emission spectra of Ar-H{sub 2} microplasma jets were recorded in the range 3060-8200 A, in order to estimate the axial distribution profiles of electron density, rotational temperature, excitation temperature and hydrogen atomic temperature.

  7. Atmospheric electric discharges and grounding systems; Descargas atmosfericas y sistemas de conexion a tierra

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, Elena [ed.] [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    In this article the work made by the Institute of Investigaciones Electricas (IIE), in the area of atmospheric electric discharges and grounding connections at Comision Federal de Electricidad (CFE) is presented. The work consisted of the revision of the procedures for the design of transmission lines and substations of CFE from which high indexes of interruptions are reported, from this, a program was defined that allowed to improve the existing designs in CFE. [Spanish] En este articulo se presenta el trabajo realizado por el Instituto de Investigaciones Electricas (IIE), en el area de descargas atmosfericas y conexiones a tierra en Comision Federal de Electricidad (CFE). El trabajo consistio en la revision de los procedimientos de diseno de las areas de transmision y subestaciones de la CFE para los que se reportan altos indices de salidas, a partir de esto se definio un programa que permitio mejorar los disenos existentes en la CFE.

  8. Diurnal variations of 218Po, 214Pb, and 214Po and their effect on atmospheric electrical conductivity in the lower atmosphere at Mysore city, Karnataka State, India

    International Nuclear Information System (INIS)

    The short-lived radon daughters (218Po, 214Pb, 214Bi and 214Po) are natural tracers in the troposphere, in particular near the ground surface. They are electrically charged particles and are chemically reactive. As soon as they are formed they get attached to the aerosol particles of the atmosphere. The behavior of radon daughters is similar to that of aerosols with respect to their growth, transport and removal processes in the atmosphere. The electrical conductivity of the atmosphere is mainly due to the presence of highly mobile ions. Galactic cosmic rays are the main source of ionization in the planetary boundary layer; however, near the surface of the earth, ions are produced mainly by decays of natural radioactive gases emanating from the soil surface and by radiations emitted directly from the surface. Hence the electrical conductivity of air near the surface of the earth is mainly due to radiations emitted by 222Rn, 218Po, 214Pb, 214Bi and 214Po, and depends on aerosol concentrations and meteorological parameters. In the present work the diurnal and seasonal variations of radon and its progeny concentrations are studied using Low Level Radon Detection System and Airflow Meter respectively. Atmospheric electrical conductivity of both positive and negative polarities is measured using a Gerdien Condenser. All the measurements were carried out simultaneously at one location in Mysore city (12°N, 76°E), India. The diurnal variation of atmospheric electrical conductivity was found to be similar to that of ion pair production rate estimated from radon and its progeny concentrations with a maximum in the early morning hours and minimum during day time. The annual average concentrations of 222Rn, 218Po, 214Pb, and 214Po at the study location were found to be 21.46, 10.88, 1.78 and 1.80 Bq m−3 respectively. The annual average values of positive and negative atmospheric electrical conductivity were found to be 18.1 and 16.6 f S m−1 respectively. The radon and

  9. Diurnal variations of (218)Po, (214)Pb, and (214)Po and their effect on atmospheric electrical conductivity in the lower atmosphere at Mysore city, Karnataka State, India.

    Science.gov (United States)

    Pruthvi Rani, K S; Paramesh, L; Chandrashekara, M S

    2014-12-01

    The short-lived radon daughters ((218)Po, (214)Pb, (214)Bi and (214)Po) are natural tracers in the troposphere, in particular near the ground surface. They are electrically charged particles and are chemically reactive. As soon as they are formed they get attached to the aerosol particles of the atmosphere. The behavior of radon daughters is similar to that of aerosols with respect to their growth, transport and removal processes in the atmosphere. The electrical conductivity of the atmosphere is mainly due to the presence of highly mobile ions. Galactic cosmic rays are the main source of ionization in the planetary boundary layer; however, near the surface of the earth, ions are produced mainly by decays of natural radioactive gases emanating from the soil surface and by radiations emitted directly from the surface. Hence the electrical conductivity of air near the surface of the earth is mainly due to radiations emitted by (222)Rn, (218)Po, (214)Pb, (214)Bi and (214)Po, and depends on aerosol concentrations and meteorological parameters. In the present work the diurnal and seasonal variations of radon and its progeny concentrations are studied using Low Level Radon Detection System and Airflow Meter respectively. Atmospheric electrical conductivity of both positive and negative polarities is measured using a Gerdien Condenser. All the measurements were carried out simultaneously at one location in Mysore city (12°N, 76°E), India. The diurnal variation of atmospheric electrical conductivity was found to be similar to that of ion pair production rate estimated from radon and its progeny concentrations with a maximum in the early morning hours and minimum during day time. The annual average concentrations of (222)Rn, (218)Po, (214)Pb, and (214)Po at the study location were found to be 21.46, 10.88, 1.78 and 1.80 Bq m(-3) respectively. The annual average values of positive and negative atmospheric electrical conductivity were found to be 18.1 and 16.6 f S m(-1

  10. Short Circuit Calculation Method for Marine Power Electrical System%舰船电力系统短路计算方法研究

    Institute of Scientific and Technical Information of China (English)

    郑福明

    2012-01-01

    随着我国舰船技术的迅猛发展,上世纪80年代出台的短路计算相关标准存在诸多局限性.首先对GJB173-1986进行探讨,分析其在当前舰船电力系统中存在的不足;继而简述叠加原理法在实船环境下的不足之处,分析层等效法在实际船用电力系统中的性能,以及其在实船应用中的各种优势,最后得出层等效法是目前较适用于舰船电力系统短路计算方法的结论.%With the great development of ship technology in China, there are more and more bugs in related criterions for the short circuit calculation of marine electrical power systems. We firstly analyzed and concluded the shorts of GJB173-1986, and summarized the keystone of the short circuit calculation algorithm based on superposition theorem, with the lacks in the marine circumstance application of algorithm. Then we introduced the level-equivalent algorithm advanced in the latest three years, expounded its performance and summed up its advantages in marine electrical power systems. At last, we concluded that the level-equivalent algorithm is an algorithm with the best performance for short circuit calculation in marine electrical power systems.

  11. MOS integrated circuit design

    CERN Document Server

    Wolfendale, E

    2013-01-01

    MOS Integral Circuit Design aims to help in the design of integrated circuits, especially large-scale ones, using MOS Technology through teaching of techniques, practical applications, and examples. The book covers topics such as design equation and process parameters; MOS static and dynamic circuits; logic design techniques, system partitioning, and layout techniques. Also featured are computer aids such as logic simulation and mask layout, as well as examples on simple MOS design. The text is recommended for electrical engineers who would like to know how to use MOS for integral circuit desi

  12. Influence of annealing atmosphere on the electrical conductivity of copper nanoparticle films

    Science.gov (United States)

    Kong, Dal Sung; Han, Gill Sang; Kim, Min Jeong; Park, So Yeon; Kim, Sung Bae; Lee, Seunghyuk; Shin, Hyunjung; Shin, Hyunho; Jung, Hyun Suk

    2016-05-01

    The oxidation, organic decomposition, and grain growth of Cu nanoparticles were systematically investigated under various heat-treatment conditions to understand the correlation between the heat-treatment condition and the electrical conductivity of nanoparticle-based copper films. The resistivity of Cu films annealed at 400°C in N2 gas was ˜3 × 102 μΩ·cm, which is two orders lower than that of a Cu film annealed in a reducing gas (˜104 μΩ·cm). The lowest resistivity of 9 μΩ·cm was achieved at an annealing temperature of 600°C in N2 gas. The N2 atmosphere containing a fairly small amount of O2 was found to remove residual organics easily and facilitate the grain growth of Cu nanoparticles, thereby yielding Cu films with superior electrical conductivity. These results clearly demonstrate the importance of precise control of oxygen during the annealing process. [Figure not available: see fulltext.

  13. Module Nine: Relationships of Current, Counter EMF, and Voltage in LR Circuits; Basic Electricity and Electronics Individualized Learning System.

    Science.gov (United States)

    Bureau of Naval Personnel, Washington, DC.

    The student will study the ways that inductance affects voltage and current in Direct Current (DC) and Alternating Current (AC) circuits and why and how inductors cause these actions. The module is divided into six lessons: rise and decay of current and voltage, LR (inductive-resistive) time constant, using the universal TC (time constant) chart,…

  14. A Study of University Students' Understanding of Simple Electric Circuits. Part 2: Batteries, Ohm's Law, Power Dissipated, Resistors in Parallel.

    Science.gov (United States)

    Picciarelli, V.; And Others

    1991-01-01

    Results of a systematic investigation into university students' (n=236) misunderstandings of d.c. simple circuit operations are reported. These results provide evidence of various misconceptions present before and after teaching the following topics: a battery as a source of constant current; the functional relation expressed by Ohm's law; power…

  15. Decrease of the electric field penetration into the ionosphere due to low conductivity at the near ground atmospheric layer

    OpenAIRE

    M. Ampferer; V. V. Denisenko; Hausleitner, W.; Krauss, S.; G. Stangl; Boudjada, M. Y.; H. K. Biernat

    2010-01-01

    It is well known that lithospheric electromagnetic emissions are generated before earthquakes occurrence. In our study, we consider the physical penetration mechanism of the electric field from the Earth's surface, through the atmosphere-ionosphere layers, and until its detection in space by satellites. A simplified approach is investigated using the electric conductivity equation, i.e., ∇ˆσ·∇Φ)=0 in the case of a vertical inclina...

  16. Electrical and spectral characteristics of an atmospheric pressure argon plasma jet generated with tube-ring electrodes in surface dielectric barrier discharge

    International Nuclear Information System (INIS)

    An atmospheric-pressure argon plasma jet is generated with tube-ring electrodes in surface dielectric barrier discharge by a sinusoidal excitation voltage at 8 kHz. The electrical and spectral characteristics are estimated such as conduction and displacement current, electric-field, electron temperature, rotational temperature of N2 and OH, electronic excitation temperature, and oxygen atomic density. It is found that the electric-field magnitudes in the top area of the ground electrode are higher than that in the bottom area of the power electrode, and the electron temperature along radial direction is in the range of 9.6–10.4 eV and along axial direction in the range of 4.9–10 eV. The rotational temperature of N2 obtained by comparing the simulated spectrum with the measured spectrum at the C3Πu → B3Πg(Δv = − 2) band transition is in the range of 342–387 K, the electronic excitation temperature determined by Boltzmann's plot method is in the range of 3188–3295 K, and the oxygen atomic density estimated by the spectral intensity ratio of atomic oxygen line λ = 844.6 nm to argon line λ = 750.4 nm is in the order of magnitude of 1016 cm−3, respectively. - Highlights: ► The conduction and displacement current are calculated by equivalent circuit diagram. ► The 2D distribution of electric-field magnitude is calculated by ElecNet software. ► The electron temperature along axial direction is in the range of 4.9–10 eV. ► The oxygen atomic density is about a magnitude of 1016 cm−3

  17. 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

  18. Circuit theory

    International Nuclear Information System (INIS)

    This book is divided into fourteen chapters, which deals with circuit theory of basis, sinusoidal alternating current on cycle and frequency, basics current circuit about R.L, C circuit and resonant circuit, current power, general linear circuit, inductive coupling circuit and vector locus on an alternating current bridge and mutual inductance and coupling coefficient, multiphase alternating current and method of symmetrical coordinates, non-sinusoidal alternating current, two terminal network, four terminal network, transient of circuits, distributed line circuit constant, frequency characteristic and a filter and Laplace transformation.

  19. Data transfer of long distance based on electric current loop circuit%基于电流环电路的远距离数据传输

    Institute of Scientific and Technical Information of China (English)

    李绍卓; 王薇

    2012-01-01

    Level switch is widely used in the process of data transfer of long distance in the area of the industrial control. This paper mainly discusses the electric current loop, which is another data transfer circuit. This circuit switches level singal to current singal, taking current as the carrier of data transfer. This circuit has the excellent performance of anti-noise in the vile industrial environment.%电平转换在工业控制远距离数据传输过程中被广泛采用,取得了良好的效果。阐述了另一种数据传输的电路——电流环,该电路将电平信号转换为电流信号,以电流作为数据传输的载体,在恶劣工业环境下具有较强的抗噪、抗干扰的能力。

  20. Dynamic electric behavior and open-circuit-voltage modeling of LiFePO{sub 4}-based lithium ion secondary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Roscher, Michael A.; Sauer, Dirk Uwe [RWTH Aachen University, Electrochemical Energy Conversion and Storage Systems Group, Institute for Power, Electronics and Electrical Drives (ISEA), Jaegerstrasse 17-19, 52066 Aachen (Germany)

    2011-01-01

    Accurate battery modeling is one of the key factors in battery system design process and operation as well. Therefore, the knowledge of the distinct electric characteristics of the battery cells is mandatory. This work gives insight to the electric characteristics of lithium ion batteries (Li-ion) comprising LiFePO{sub 4}-based cathode active materials with emphasis on their specific open-circuit-voltage (OCV) characteristics including hysteresis and special OCV recovery effects, which last for several minutes or even hours after a current load is interrupted. These effects are elucidated incorporating OCV measurement data of high power cells. Simple empiric models are derived and used in a model-based state estimation algorithm. The complete battery model includes an impedance model, a hysteresis model and an OCV recovery model part. The introduced model enables the assessment of the cells' state-of-charge (SOC) precisely using model-based state estimation approaches. (author)

  1. Electrodynamical Coupling of Earth's Atmosphere and Ionosphere: An Overview

    Directory of Open Access Journals (Sweden)

    A. K. Singh

    2011-01-01

    Full Text Available Electrical processes occurring in the atmosphere couple the atmosphere and ionosphere, because both DC and AC effects operate at the speed of light. The electrostatic and electromagnetic field changes in global electric circuit arise from thunderstorm, lightning discharges, and optical emissions in the mesosphere. The precipitation of magnetospheric electrons affects higher latitudes. The radioactive elements emitted during the earthquakes affect electron density and conductivity in the lower atmosphere. In the present paper, we have briefly reviewed our present understanding of how these events play a key role in energy transfer from the lower atmosphere to the ionosphere, which ultimately results in the Earth's atmosphere-ionosphere coupling.

  2. ASPECTS REGARDING THE DESIGN AND PERFORMANCE OF FLAMEPROOF ELECTRIC MOTORS SUPPLIED VIA STATIC FREQUENCY CONVERTERS FOR EXPLOSIVE ATMOSPHERES

    Directory of Open Access Journals (Sweden)

    Mihai MAGYARI

    2012-05-01

    Full Text Available The electric power drive systems consisting of three phase induction motor and static frequency converter are designed to enhance the performance on site, by diminishing the energy consumption, optimization of the technological processes and the reduction of costs for the maintenance and repairs of the equipment. The paper presents some important issues concerning the selection of inverter fed flameproof electric drives in the field of potentially explosive atmospheres of gases and vapors by ensuring a correct risk management against the hazard of electric sparks as well as excessive temperatures

  3. Electrifying atmospheres charging, ionisation and lightning in the solar system and beyond

    CERN Document Server

    Aplin, Karen L

    2013-01-01

    Electrical processes take place in all planetary atmospheres. There is evidence for lightning on Venus, Jupiter, Saturn, Uranus and Neptune, it is possible on Mars and Titan, and cosmic rays ionise every atmosphere, leading to charged droplets and particles. Controversy surrounds the role of atmospheric electricity in physical climate processes on Earth; here, a comparative approach is employed to review the role of electrification in the atmospheres of other planets and their moons. This book reviews the theory, and, where available, measurements, of planetary atmospheric electricity, taken to include ion production and ion-aerosol interactions. The conditions necessary for a global atmospheric electric circuit similar to Earth’s, and the likelihood of meeting these conditions in other planetary atmospheres, are briefly discussed. Atmospheric electrification is more important at planets receiving little solar radiation, increasing the relative significance of electrical forces. Nucleation onto atmospheric ...

  4. Linking neuroscientific research on decision making to the educational context of novice students assigned to a multiple-choice scientific task involving common misconceptions about electrical circuits

    Directory of Open Access Journals (Sweden)

    Patrice ePotvin

    2014-01-01

    Full Text Available Functional magnetic resonance imaging was used to identify the brain-based mechanisms of uncertainty and certainty associated with answers to multiple-choice questions involving common misconceptions about electric circuits. Twenty-two (22 scientifically novice participants (humanities and arts college students were asked, in an fMRI study, whether or not they thought the light bulbs in images presenting electric circuits were lighted up correctly, and if they were certain or uncertain of their answers. When participants reported that they were unsure of their responses, analyses revealed significant activations in brain areas typically involved in uncertainty (anterior cingulate cortex, anterior insula cortex, and superior/dorsomedial frontal cortex and in the left middle/superior temporal lobe. Certainty was associated with large bilateral activations in the occipital and parietal regions usually involved in visuospatial processing. Correct-and-certain answers were associated with activations that suggest a stronger mobilization of visual attention resources when compared to incorrect-and-certain answers. These findings provide insights into brain-based mechanisms of uncertainty that are activated when common misconceptions, identified as such by science education research literature, interfere in decision making in a school-like task. We also discuss the implications of these results from an educational perspective.

  5. Lithium Ion Batteries—Development of Advanced Electrical Equivalent Circuit Models for Nickel Manganese Cobalt Lithium-Ion

    OpenAIRE

    Alexandros Nikolian; Yousef Firouz; Rahul Gopalakrishnan; Jean-Marc Timmermans; Noshin Omar; Peter Van den Bossche; Joeri van Mierlo

    2016-01-01

    In this paper, advanced equivalent circuit models (ECMs) were developed to model large format and high energy nickel manganese cobalt (NMC) lithium-ion 20 Ah battery cells. Different temperatures conditions, cell characterization test (Normal and Advanced Tests), ECM topologies (1st and 2nd Order Thévenin model), state of charge (SoC) estimation techniques (Coulomb counting and extended Kalman filtering) and validation profiles (dynamic discharge pulse test (DDPT) and world harmonized light v...

  6. Power-factor compensation of electrical circuits. A framework for analysis and design in the nonlinear nonsinusoidal case.

    OpenAIRE

    García Canseco, Eloísa; Griñó Cubero, Robert; Ortega, Romeo; Salichs Vivancos, Miguel; Stankovic, Alexander

    2007-01-01

    This article advances an analysis and compensator design framework for power-factor compensation based on cyclodissipativity. Although the framework applies to general polyphase unbalanced circuits, this paper have focused on the problem of power factor compensation with LTI capacitors or inductors of single-phase loads. The full power of the approach are expected to become evident for polyphase unbalanced loads with possibly nonlinear lossless compensators, where the existing solutions are f...

  7. Online model-based estimation of state-of-charge and open-circuit voltage of lithium-ion batteries in electric vehicles

    International Nuclear Information System (INIS)

    This paper presents a method to estimate the state-of-charge (SOC) of a lithium-ion battery, based on an online identification of its open-circuit voltage (OCV), according to the battery’s intrinsic relationship between the SOC and the OCV for application in electric vehicles. Firstly an equivalent circuit model with n RC networks is employed modeling the polarization characteristic and the dynamic behavior of the lithium-ion battery, the corresponding equations are built to describe its electric behavior and a recursive function is deduced for the online identification of the OCV, which is implemented by a recursive least squares (RLS) algorithm with an optimal forgetting factor. The models with different RC networks are evaluated based on the terminal voltage comparisons between the model-based simulation and the experiment. Then the OCV-SOC lookup table is built based on the experimental data performed by a linear interpolation of the battery voltages at the same SOC during two consecutive discharge and charge cycles. Finally a verifying experiment is carried out based on nine Urban Dynamometer Driving Schedules. It indicates that the proposed method can ensure an acceptable accuracy of SOC estimation for online application with a maximum error being less than 5.0%. -- Highlights: ► An equivalent circuit model with n RC networks is built for lithium-ion batteries. ► A recursive function is deduced for the online estimation of the model parameters like OCV and RO. ► The relationship between SOC and OCV is built with a linear interpolation method by experiments. ► The experiments show the online model-based SOC estimation is reasonable with enough accuracy.

  8. Design and construction of prototype transversely excited atmospheric (TEA) nitrogen laser energized by a high voltage electrical discharge

    OpenAIRE

    Mukhtar Hussain; Tayyab Imran

    2015-01-01

    The present study reports design and construction, of a prototype of Transversely Excited Atmospheric (TEA) nitrogen laser, and a high voltage power supply to excite N2 gas in air, while air is used as an active lasing medium. A Blumlein line discharge circuit is used for operation of this laser. The high voltage is generated by a fly back transformer based power supply varying from 10 kV to 20 kV. The wavelength (337.1 nm) of TEA nitrogen laser is measured employing a standard commercial spe...

  9. Cloud conditions for low atmospheric electricity during disturbed period after the Fukushima nuclear accident

    Science.gov (United States)

    Yatagai, Akiyo; Yamauchi, Masatoshi; Ishihara, Masahito; Watanabe, Akira; Murata, Ken T.

    2016-04-01

    The vertical (downward) component of the atmospheric electric field, or potential gradient (PG) under cloud generally reflects the electric charge distribution in the cloud. The PG data at Kakioka, 150 km southwest of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) suggested that this relation can be modified when the radioactive dust was floating in the air, and the exact relation between the weather and this modification could lead to new insight in plasma physics in the wet atmosphere. Unfortunately the detailed weather data was not available above Kakioka (only the precipitation data was available). Therefore, estimation of the cloud condition during March 2011 was strongly needed. We have developed various meteorological information links (http://www.chikyu.ac.jp/akiyo/firis/) and original radar and precipitation data will be released from the page. Here we present various radar images that we have prepared for March 2011. We prepared three-dimensional radar reflectivity of the C-band radar of JMA in every 10 minutes over all Kanto Plain centered at Tokyo and Fukushima prefecture centered at Sendai. We have released images of each altitude (1km interval) for 15th - 16thand 21th March (http://sc-web.nict.go.jp/fukushima/). The vertical structure of the rainfall is almost the same at 4km with the surface and sporadic high precipitation is observed at 6 km height for 15-16th. While, generally precipitation pattern that is similar to the surface is observed at 5km height on 21th. On the other hand, an X-band radar centered at Fukushima university is also used to know more localized raindrop patterns at zenith angle of 4 degree. We prepared 10-minutes/120m mesh precipitation patterns for March 15th, 16th, 17th, 18th, 20th, 21th, 22th and 23th. Quantitative estimate is difficult from this X-band radar, but localized structure, especially for the rain-band along Nakadori (middle valley in Fukushima prefecture), that is considered to determine the highly

  10. Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement

    International Nuclear Information System (INIS)

    Radioactive materials from the accident at Fukushima Dai-ichi nuclear power plant (FNPP) in March 2011 spread over a large area, increasing the atmospheric electric conductivity by their ionizing effect, and reducing the vertical (downward) component of the DC electric field near the ground, or potential gradient (PG). PG data at Kakioka, 150 km away from the FNPP, showed independent changes compared to the radiation dose rate, and a comparison of these data revealed the local dynamics of the radioactive dust. (1) The initial drop of the PG to almost zero during 14-15 March is most likely due to radioactive dust suspended in the air near the ground during cloudy weather. (2) An episode of PG increase to more than 50Vm-1 on 16 March is most likely due to the re-suspension of the radioactive dust from the surface and subsequent removal from Kakioka by the strong wind from the non-contaminated area. (3) Low but finite values of the PG during 16-20 March most likely reflect a reduced amount of radioactive material near the ground after the above wind transported away the majority of the suspended radioactive dust. (4) Very low values of the PG after substantial rain on 20-22 March most likely reflect settlement of the radioactive material by rain-induced fallout. (5) Temporal recovery of daily variations from the end of March to the middle of April with low nighttime fair-weather baseline PG most likely reflects re-suspension of the radioactive dust into the air from the ground and trees, and subsequent transport to the other region or fallout to the ground until late April. (6) Weakening of the daily variation and gradual recovery of the nighttime fair-weather baseline after mid-April suggests a complete settlement of the radioactive material to the ground with partial migration to the subsurface. (orig.)

  11. Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement

    Directory of Open Access Journals (Sweden)

    M. Yamauchi

    2012-01-01

    Full Text Available Radioactive materials from the accident at Fukushima Dai-ichi nuclear power plant (FNPP in March 2011 spread over a large area, increasing the atmospheric electric conductivity by their ionizing effect, and reducing the vertical (downward component of the DC electric field near the ground, or potential gradient (PG. PG data at Kakioka, 150 km away from the FNPP, showed independent changes compared to the radiation dose rate, and a comparison of these data revealed the local dynamics of the radioactive dust.

    (1 The initial drop of the PG to almost zero during 14–15 March is most likely due to radioactive dust suspended in the air near the ground during cloudy weather. (2 An episode of PG increase to more than 50 V m−1 on 16 March is most likely due to the re-suspension of the radioactive dust from the surface and subsequent removal from Kakioka by the strong wind from the non-contaminated area. (3 Low but finite values of the PG during 16–20 March most likely reflect a reduced amount of radioactive material near the ground after the above wind transported away the majority of the suspended radioactive dust. (4 Very low values of the PG after substantial rain on 20–22 March most likely reflect settlement of the radioactive material by rain-induced fallout. (5 Temporal recovery of daily variations from the end of March to the middle of April with low nighttime fair-weather baseline PG most likely reflects re-suspension of the radioactive dust into the air from the ground and trees, and subsequent transport to the other region or fallout to the ground until late April. (6 Weakening of the daily variation and gradual recovery of the nighttime fair-weather baseline after mid-April suggests a complete settlement of the radioactive material to the ground with partial migration to the subsurface.

  12. Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement

    Energy Technology Data Exchange (ETDEWEB)

    Yamauchi, M. [Swedish Institute of Space Physics, Kiruna (Sweden); Takeda, M. [Kyoto Univ. (Japan). Data Analysis Center for Geomagnetism and Space Magnetism; Makino, M.; Miyagi, I. [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan); Owada, T. [Japan Meteorological Agency, Ishioka (Japan). Kakioka Magnetic Observatory

    2012-07-01

    Radioactive materials from the accident at Fukushima Dai-ichi nuclear power plant (FNPP) in March 2011 spread over a large area, increasing the atmospheric electric conductivity by their ionizing effect, and reducing the vertical (downward) component of the DC electric field near the ground, or potential gradient (PG). PG data at Kakioka, 150 km away from the FNPP, showed independent changes compared to the radiation dose rate, and a comparison of these data revealed the local dynamics of the radioactive dust. (1) The initial drop of the PG to almost zero during 14-15 March is most likely due to radioactive dust suspended in the air near the ground during cloudy weather. (2) An episode of PG increase to more than 50Vm{sup -1} on 16 March is most likely due to the re-suspension of the radioactive dust from the surface and subsequent removal from Kakioka by the strong wind from the non-contaminated area. (3) Low but finite values of the PG during 16-20 March most likely reflect a reduced amount of radioactive material near the ground after the above wind transported away the majority of the suspended radioactive dust. (4) Very low values of the PG after substantial rain on 20-22 March most likely reflect settlement of the radioactive material by rain-induced fallout. (5) Temporal recovery of daily variations from the end of March to the middle of April with low nighttime fair-weather baseline PG most likely reflects re-suspension of the radioactive dust into the air from the ground and trees, and subsequent transport to the other region or fallout to the ground until late April. (6) Weakening of the daily variation and gradual recovery of the nighttime fair-weather baseline after mid-April suggests a complete settlement of the radioactive material to the ground with partial migration to the subsurface. (orig.)

  13. Microstructural evolution of Cu-1at% Ti alloy aged in a hydrogen atmosphere and its relation with the electrical conductivity.

    Science.gov (United States)

    Semboshi, Satoshi; Al-Kassab, Talaat; Gemma, Ryota; Kirchheim, Reiner

    2009-04-01

    Copper alloys with titanium additions between 1 and 6at% Ti emerge currently as attractive conductive materials for electrical and electronic commercial products, since they exhibit superior mechanical and electrical properties. However, their electrical conductivity is reduced owing to the residual amount of Ti solutes in the Cu solid solution (Cu(ss)) phase. Since Cu shows only poor reactivity with hydrogen (H), while Ti exhibits high affinity to it, we were inspired by the idea that hydrogenation of Cu-Ti alloys would influence their microstructure, resulting in a significant change of their properties. In this contribution, the influence of aging under a deuterium (D(2)) atmosphere of Cu-1at% Ti alloys on their microstructure is investigated to explore the effects on the electrical conductivity. The specimens were investigated by means of transmission electron microscopy (TEM), field ion microscopy (FIM), computer-aided field ion image tomography (cFIIT), and atom probe tomography (APT). At an early aging stage at 623K in a D(2) atmosphere of 0.08MPa, ellipsoidal alpha-Cu(4)Ti precipitates are formed in the alloy, and during subsequent aging, delta-TiD(2) is competitively nucleated instead of growth of alpha-Cu(4)Ti particles. The co-precipitation of alpha-Cu(4)Ti and delta-TiD(2) efficiently reduces the Ti concentration of Cu(ss) matrix, particularly in the later aging stages in comparison to the aging in vacuum conditions. The electrical conductivity of the alloy aged in the D(2) atmosphere increases steeply up to 48% International Annealed Copper Standard (IACS) after 1030h, while it saturates to approximately 20% IACS in the alloy aged in vacuum. The outstanding increase of electrical conductivity during aging in D(2) atmosphere can be basically explained by the reduction of Ti solute concentration in Cu(ss) matrix. PMID:19243888

  14. Microstructural evolution of Cu-1at% Ti alloy aged in a hydrogen atmosphere and its relation with the electrical conductivity

    KAUST Repository

    Semboshi, Satoshi

    2009-04-01

    Copper alloys with titanium additions between 1 and 6 at% Ti emerge currently as attractive conductive materials for electrical and electronic commercial products, since they exhibit superior mechanical and electrical properties. However, their electrical conductivity is reduced owing to the residual amount of Ti solutes in the Cu solid solution (Cu(ss)) phase. Since Cu shows only poor reactivity with hydrogen (H), while Ti exhibits high affinity to it, we were inspired by the idea that hydrogenation of Cu-Ti alloys would influence their microstructure, resulting in a significant change of their properties. In this contribution, the influence of aging under a deuterium (D(2)) atmosphere of Cu-1 at% Ti alloys on their microstructure is investigated to explore the effects on the electrical conductivity. The specimens were investigated by means of transmission electron microscopy (TEM), field ion microscopy (FIM), computer-aided field ion image tomography (cFIIT), and atom probe tomography (APT). At an early aging stage at 623 K in a D(2) atmosphere of 0.08 Wit, ellipsoidal alpha-Cu(4)Ti precipitates are formed in the alloy, and during subsequent aging, delta-TiD(2) is competitively nucleated instead of growth of alpha-Cu(4)Ti particles. The co-precipitation of alpha-Cu(4)Ti and delta-TiD(2) efficiently reduces the Ti concentration of Cuss matrix, particularly in the later aging stages in comparison to the aging in vacuum conditions. The electrical conductivity of the alloy aged in the D(2) atmosphere increases steeply up to 48% International Annealed Copper Standard (IACS) after 1030 It, while it saturates to approximately 20% IACS in the alloy aged in vacuum. The outstanding increase of electrical conductivity during aging in D2 atmosphere can be basically explained by the reduction of Ti solute concentration in Cuss matrix. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.

  15. Nucleation and aerosol processing in atmospheric pressure electrical discharges: powders production, coatings and filtration

    International Nuclear Information System (INIS)

    This review addresses the production of nano-particles and the processing of particles injected in atmospheric pressure electrical discharges (APED). The mechanisms of formation and the evolution of particles suspended in gases are first presented, with numerical and experimental facilities. Different APED and related properties are then introduced for dc corona, streamer and spark filamentary discharges (FD), as well as for ac filamentary and homogeneous dielectric barrier discharges (DBD). Two mechanisms of particle production are depicted in APED: when FD interact with the surface of electrodes or dielectrics and when filamentary and homogeneous DBD induce reactions with gaseous precursors in volume. In both cases, condensable gaseous species are produced, leading to nano-sized particles by physical and chemical routes of nucleation. The evolution of the so-formed nano-particles, i.e. the growth by coagulation/condensation, the charging and the collection are detailed for each APED, with respect to fine powders production and thin films deposition. Finally, when particles are injected in APED, they undergo interfacial processes. Non-thermal plasmas charge particles for electro-collection and trigger heterogeneous chemical reactions for organic and inorganic films deposition. Heat exchanges in thermal plasmas enable powder purification, shaping, melting for hard coatings and fine powders production by reactive evaporation. (topical review)

  16. TOPICAL REVIEW: Nucleation and aerosol processing in atmospheric pressure electrical discharges: powders production, coatings and filtration

    Science.gov (United States)

    Borra, Jean-Pascal

    2006-01-01

    This review addresses the production of nano-particles and the processing of particles injected in atmospheric pressure electrical discharges (APED). The mechanisms of formation and the evolution of particles suspended in gases are first presented, with numerical and experimental facilities. Different APED and related properties are then introduced for dc corona, streamer and spark filamentary discharges (FD), as well as for ac filamentary and homogeneous dielectric barrier discharges (DBD). Two mechanisms of particle production are depicted in APED: when FD interact with the surface of electrodes or dielectrics and when filamentary and homogeneous DBD induce reactions with gaseous precursors in volume. In both cases, condensable gaseous species are produced, leading to nano-sized particles by physical and chemical routes of nucleation. The evolution of the so-formed nano-particles, i.e. the growth by coagulation/condensation, the charging and the collection are detailed for each APED, with respect to fine powders production and thin films deposition. Finally, when particles are injected in APED, they undergo interfacial processes. Non-thermal plasmas charge particles for electro-collection and trigger heterogeneous chemical reactions for organic and inorganic films deposition. Heat exchanges in thermal plasmas enable powder purification, shaping, melting for hard coatings and fine powders production by reactive evaporation.

  17. Organic synthesis from reducing models of the atmosphere of the primitive earth with UV light and electric discharges.

    Science.gov (United States)

    Bossard, A R; Raulin, F; Mourey, D; Toupance, G

    1982-01-01

    The purpose of this paper is to compare the role of UV light and of electric discharges, the two most important sources of energy on the primitive earth, in the synthesis of organic compounds out of a reducing model of that atmosphere. Since Miller's experiments in 1953, most of the experimental simulations have been performed with electric discharges, and it has been assumed that UV radiations would give similar results. In order to check this assumption we have performed both experimental simulations in our laboratory. Experimental results indicate that this assumption was wrong in a large extent. Our four main conclusions are: 1. Unlike electric discharges, UV light is not an efficient source for producing unsaturated carbon chains. 2. UV light is efficient for producing nitriles in CH4--NH3 mixtures when the mole fraction of NH3 is very low while electric discharges need a higher mole fraction of NH3. 3. UV light is not able to produce nitriles from CH4--N2 mixtures while electric discharges produce important quantities of diversified nitriles from these mixtures. 4. UV light is not very efficient for producing aldehydes from CH4--H2O model atmosphere, electric discharges seem to be able to produce them more efficiently. PMID:7097776

  18. Extended Aging of Ag/W Circuit Breaker Contacts: Influence on Surface Structure, Electrical Properties, and UL Testing Performance

    Science.gov (United States)

    Yu, Haibo; Kesim, M. Tumerkan; Sun, Yu; Harmon, Jason; Potter, Jonathan; Alpay, S. Pamir; Aindow, Mark

    2016-01-01

    Samples of 120 V, 30 A commercial circuit breakers were subjected to various aging treatments and the resulting microstructures at the surfaces of the Ag/W contacts were studied using a combination of x-ray diffraction, scanning electron microscopy, and energy-dispersive x-ray spectroscopy techniques. Breakers aged naturally in a hot, humid climate were compared to those subjected to accelerated aging in dry and humid environments. The most extensive oxidation was observed for contacts from breakers subjected to accelerated humid aging; these contacts exhibited thick surface layers consisting of Ag2O, Ag2WO4, Cu(OH)2•H2O, and WO3 phases. Far less surface degradation was observed for dry-aged contacts. Naturally aged contacts showed variations in degradation with more oxidation at the surface regions outside the physical contact area on the contact face. A correlation was found between the contact resistances measured from these samples following ASTM standard B 667-97 and the observed surface microstructures. To evaluate the effects of the surface oxides on breaker performance, humid-aged breakers were subjected to standardized UL overload/temperature-rise, endurance, and short-circuit testing following UL489. The contacts in these breakers exhibit similar microstructural and property changes to those observed previously for as-manufactured contacts after UL testing. These data illustrate the robust performance of this contact technology even after being subjected to aggressive artificial aging.

  19. 14 CFR 23.1357 - Circuit protective devices.

    Science.gov (United States)

    2010-01-01

    ... circuit breakers, must be installed in all electrical circuits other than— (1) Main circuits of starter... circuit breaker or replace a fuse is essential to safety in flight, that circuit breaker or fuse must be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Circuit protective devices. 23.1357...

  20. Evaluation and optimization of quartz resonant-frequency retuned fork force sensors with high Q factors, and the associated electric circuits, for non-contact atomic force microscopy

    Science.gov (United States)

    Ooe, Hiroaki; Fujii, Mikihiro; Tomitori, Masahiko; Arai, Toyoko

    2016-02-01

    High-Q factor retuned fork (RTF) force sensors made from quartz tuning forks, and the electric circuits for the sensors, were evaluated and optimized to improve the performance of non-contact atomic force microscopy (nc-AFM) performed under ultrahigh vacuum (UHV) conditions. To exploit the high Q factor of the RTF sensor, the oscillation of the RTF sensor was excited at its resonant frequency, using a stray capacitance compensation circuit to cancel the excitation signal leaked through the stray capacitor of the sensor. To improve the signal-to-noise (S/N) ratio in the detected signal, a small capacitor was inserted before the input of an operational (OP) amplifier placed in an UHV chamber, which reduced the output noise from the amplifier. A low-noise, wideband OP amplifier produced a superior S/N ratio, compared with a precision OP amplifier. The thermal vibrational density spectra of the RTF sensors were evaluated using the circuit. The RTF sensor with an effective spring constant value as low as 1000 N/m provided a lower minimum detection limit for force differentiation. A nc-AFM image of a Si(111)-7 × 7 surface was produced with atomic resolution using the RTF sensor in a constant frequency shift mode; tunneling current and energy dissipation images with atomic resolution were also simultaneously produced. The high-Q factor RTF sensor showed potential for the high sensitivity of energy dissipation as small as 1 meV/cycle and the high-resolution analysis of non-conservative force interactions.

  1. Integrating Solar Power onto the Electric Grid - Bridging the Gap between Atmospheric Science, Engineering and Economics

    Science.gov (United States)

    Ghonima, M. S.; Yang, H.; Zhong, X.; Ozge, B.; Sahu, D. K.; Kim, C. K.; Babacan, O.; Hanna, R.; Kurtz, B.; Mejia, F. A.; Nguyen, A.; Urquhart, B.; Chow, C. W.; Mathiesen, P.; Bosch, J.; Wang, G.

    2015-12-01

    One of the main obstacles to high penetrations of solar power is the variable nature of solar power generation. To mitigate variability, grid operators have to schedule additional reliability resources, at considerable expense, to ensure that load requirements are met by generation. Thus despite the cost of solar PV decreasing, the cost of integrating solar power will increase as penetration of solar resources onto the electric grid increases. There are three principal tools currently available to mitigate variability impacts: (i) flexible generation, (ii) storage, either virtual (demand response) or physical devices and (iii) solar forecasting. Storage devices are a powerful tool capable of ensuring smooth power output from renewable resources. However, the high cost of storage is prohibitive and markets are still being designed to leverage their full potential and mitigate their limitation (e.g. empty storage). Solar forecasting provides valuable information on the daily net load profile and upcoming ramps (increasing or decreasing solar power output) thereby providing the grid advance warning to schedule ancillary generation more accurately, or curtail solar power output. In order to develop solar forecasting as a tool that can be utilized by the grid operators we identified two focus areas: (i) develop solar forecast technology and improve solar forecast accuracy and (ii) develop forecasts that can be incorporated within existing grid planning and operation infrastructure. The first issue required atmospheric science and engineering research, while the second required detailed knowledge of energy markets, and power engineering. Motivated by this background we will emphasize area (i) in this talk and provide an overview of recent advancements in solar forecasting especially in two areas: (a) Numerical modeling tools for coastal stratocumulus to improve scheduling in the day-ahead California energy market. (b) Development of a sky imager to provide short term

  2. Overriding Faulty Circuit Breakers

    Science.gov (United States)

    Robbins, Richard L.; Pierson, Thomas E.

    1987-01-01

    Retainer keeps power on in emergency. Simple mechanical device attaches to failed aircraft-type push/pull circuit breaker to restore electrical power temporarily until breaker replaced. Device holds push/pull button in closed position; unnecessary for crewmember to hold button in position by continual finger pressure. Sleeve and plug hold button in, overriding mechanical failure in circuit breaker. Windows in sleeve show button position.

  3. Electrical measurements in the atmosphere and the Ionosphere over an active thunderstorm. II - Direct current electric fields and conductivity

    Science.gov (United States)

    Holzworth, R. H.; Kelley, M. C.; Siefring, C. L.; Hale, L. C.; Mitchell, J. D.

    1985-01-01

    On August 9, 1981, a series of three rockets was launched over an air mass thunderstorm off the eastern seaboard of Virginia while simultaneous stratospheric and ground-based electric field measurements were made. The conductivity was substantially lower at most altitudes than the conductivity profiles used by theoretical models. Direct current electric fields over 80 mV/m were measured as far away as 96 km from the storm in the stratosphere at 23 km altitude. No dc electric fields above 75 km altitude could be identified with the thunderstorm, in agreement with theory. However, vertical current densities over 120 pA/sq m were seen well above the classical 'electrosphere' (at 50 or 60 km). Frequent dc shifts in the electric field following lightning transients were seen by both balloon and rocket payloads. These dc shifts are clearly identifiable with either cloud-to-ground (increases) or intercloud (decreases) lightning flashes.

  4. Circuit analysis with Multisim

    CERN Document Server

    Baez-Lopez, David

    2011-01-01

    This book is concerned with circuit simulation using National Instruments Multisim. It focuses on the use and comprehension of the working techniques for electrical and electronic circuit simulation. The first chapters are devoted to basic circuit analysis.It starts by describing in detail how to perform a DC analysis using only resistors and independent and controlled sources. Then, it introduces capacitors and inductors to make a transient analysis. In the case of transient analysis, it is possible to have an initial condition either in the capacitor voltage or in the inductor current, or bo

  5. 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.

  6. 光学消像旋的电路控制系统研究%Electric circuit of optical image de-rotation

    Institute of Scientific and Technical Information of China (English)

    刘飞; 鱼云岐; 郭新胜; 李红光; 韩瑞

    2011-01-01

    针对周视光电观瞄系统中机械传动装置实现光学消像旋的情况,分析了传统光学消像旋的利弊.通过简化机械装置,建立了控制对象的数学模型,根据系统实时控制处理的要求,设计了数字控制和模拟控制的混合电路,提高了系统的稳定性和可靠性.运用MATLAB/SIMU-LINK对控制系统的典型情况进行仿真.仿真结果表明,该电路系统都能满足精度和实时性等指标要求.%Based on the optical image de-rotation implemented by the transmission mechanism of a panoramic observation sight, the advantages and weaknesses of traditional optical de-rotation methods were analyzed. By simplifying the mechanism, the mathematical model of the controlled object was established. According to the system requirements of real-time controlling and processing, the digital-analog control hybrid circuits were designed, which improved the stability and reliability of the system. A typical instance of the control system was simulated with MATLAB/SIMULINK, the results show that the electric circuit can meet the requirements of stability and real-time processing.

  7. Electrical Characterization of Metal-Insulator-Metal Capacitors with Atomic-Layer-Deposited HfO2 Dielectrics for Radio Frequency Integrated Circuit Application

    Institute of Scientific and Technical Information of China (English)

    HUANG Yu-Jian; HUANG Yue; DING Shi-Jin; ZHANG Wei; LIU Ran

    2007-01-01

    Metal-insulator-metal (MIM) capacitors with atomic-layer-deposited HfO2 dielectric and TaN electrodes are investigated for rf integrated circuit applications. For 12nm HfO2, the fabricated capacitor exhibits a high capacitance density of 15.5fF/μm2 at 100kHz, a small leakage current density of 6.4 × 10-9 A/cm2 at 1.8 V and 125℃, a breakdown electric field of 2.6 MV/cm as well as voltage coefficients of capacitance (VCCs) of 2110ppm/V2 and -824 ppm/V at 100kHz. Further, it is deduced that the conduction mechanism in the high field range is dominated by the Poole-Frenkel emission, and the conduction mechanism in the low field range is possibly related to trap-assisted tunnelling. Finally, comparison of various HfO2 MIM capacitors is present,suggesting that the present MIM capacitor is a promising candidate for future rf integrated circuit application.

  8. Spotting the earth connection and short circuits between the electric conductors, using D.C. bridges for resistance measurements

    Science.gov (United States)

    Popa, I.; Popa, G. N.; Deaconu, S. I.; Iagăr, A.

    2015-06-01

    The paper establishes the necessary connections meant to spot the earth connections and short circuits between the conductors of a power line, using the DC bridges meant for measuring resistances between conductors at the ends of the power line. Since it is a relative method, it imposes an exact knowledge of the faulty power line setting. For values of the resistances measured between the conductors of the power line having over 1Ω at one end, the measurement will be carried out with a Wheatstone bridge, and for values below 1Ω with a Thomson bridge. In order to accurately determine the place of the fault, it measured the distances from the end of the line up to the fault and then we performed a correction calculation for this distance.

  9. Printed transparent electrodes containing carbon nanotubes for elastic circuits applications with enhanced electrical durability under severe conditions

    International Nuclear Information System (INIS)

    Organic composites filled with nanostructures are new group of materials with unique physical properties. Carbon nanotubes (CNTs) are demonstrating good electrical and mechanical properties. This enables to produce conductive polymer-CNT thick films optically transparent, which are highly useful in production of printed electronic paper. Currently used indium tin oxide (ITO) and antimony tin oxide (ATO) films exhibit high optical transmittance with reasonable electrical conductivity, but very low resilience to mechanical stresses. This is one of the key problems in fabrication of flexible electronic displays. Current authors' achievements include fabrication of transparent electrodes obtained by screen printing technique, used for production of fully functional thick film electroluminescent structures.

  10. 49 CFR 236.721 - Circuit, control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates....

  11. Nanosecond pulsed electric fields (nsPEFs) low cost generator design using power MOSFET and Cockcroft-Walton multiplier circuit as high voltage DC source

    International Nuclear Information System (INIS)

    Purpose: Non-ionizing radiation therapy for cancer using pulsed electric field with high intensity field has become an interesting field new research topic. A new method using nanosecond pulsed electric fields (nsPEFs) offers a novel means to treat cancer. Not like the conventional electroporation, nsPEFs able to create nanopores in all membranes of the cell, including membrane in cell organelles, like mitochondria and nucleus. NsPEFs will promote cell death in several cell types, including cancer cell by apoptosis mechanism. NsPEFs will use pulse with intensity of electric field higher than conventional electroporation, between 20–100 kV/cm and with shorter duration of pulse than conventional electroporation. NsPEFs requires a generator to produce high voltage pulse and to achieve high intensity electric field with proper pulse width. However, manufacturing cost for creating generator that generates a high voltage with short duration for nsPEFs purposes is highly expensive. Hence, the aim of this research is to obtain the low cost generator design that is able to produce a high voltage pulse with nanosecond width and will be used for nsPEFs purposes. Method: Cockcroft-Walton multiplier circuit will boost the input of 220 volt AC into high voltage DC around 1500 volt and it will be combined by a series of power MOSFET as a fast switch to obtain a high voltage with nanosecond pulse width. The motivation using Cockcroft-Walton multiplier is to acquire a low-cost high voltage DC generator; it will use capacitors and diodes arranged like a step. Power MOSFET connected in series is used as voltage divider to share the high voltage in order not to damage them. Results: This design is expected to acquire a low-cost generator that can achieve the high voltage pulse in amount of −1.5 kV with falltime 3 ns and risetime 15 ns into a 50Ω load that will be used for nsPEFs purposes. Further detailed on the circuit design will be explained at presentation

  12. Nanosecond pulsed electric fields (nsPEFs) low cost generator design using power MOSFET and Cockcroft-Walton multiplier circuit as high voltage DC source

    Energy Technology Data Exchange (ETDEWEB)

    Sulaeman, M. Y.; Widita, R. [Department of Physics, Nuclear Physics and Biophysics Research Division, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Bandung (Indonesia)

    2014-09-30

    Purpose: Non-ionizing radiation therapy for cancer using pulsed electric field with high intensity field has become an interesting field new research topic. A new method using nanosecond pulsed electric fields (nsPEFs) offers a novel means to treat cancer. Not like the conventional electroporation, nsPEFs able to create nanopores in all membranes of the cell, including membrane in cell organelles, like mitochondria and nucleus. NsPEFs will promote cell death in several cell types, including cancer cell by apoptosis mechanism. NsPEFs will use pulse with intensity of electric field higher than conventional electroporation, between 20–100 kV/cm and with shorter duration of pulse than conventional electroporation. NsPEFs requires a generator to produce high voltage pulse and to achieve high intensity electric field with proper pulse width. However, manufacturing cost for creating generator that generates a high voltage with short duration for nsPEFs purposes is highly expensive. Hence, the aim of this research is to obtain the low cost generator design that is able to produce a high voltage pulse with nanosecond width and will be used for nsPEFs purposes. Method: Cockcroft-Walton multiplier circuit will boost the input of 220 volt AC into high voltage DC around 1500 volt and it will be combined by a series of power MOSFET as a fast switch to obtain a high voltage with nanosecond pulse width. The motivation using Cockcroft-Walton multiplier is to acquire a low-cost high voltage DC generator; it will use capacitors and diodes arranged like a step. Power MOSFET connected in series is used as voltage divider to share the high voltage in order not to damage them. Results: This design is expected to acquire a low-cost generator that can achieve the high voltage pulse in amount of −1.5 kV with falltime 3 ns and risetime 15 ns into a 50Ω load that will be used for nsPEFs purposes. Further detailed on the circuit design will be explained at presentation.

  13. Radioactive contamination processes during 14-21 March after the Fukushima accident: What does atmospheric electric field measurements tell us?

    Science.gov (United States)

    Takeda, M.; Yamauchi, M.; Makino, M.; Owada, T.; Miyagi, I.

    2012-04-01

    Ionizing radiation from the radioactive material is known to increase atmospheric electric conductivity, and hence to decrease vertical downward atmospheric DC electric field at ground level, or potential gradient (PG). In the past, the drop of PG has been observed after rain-induced radioactive fallout (wet contamination) after nuclear tests or after the Chernobyl disaster. After the nuclear accident Fukushima Dai-ichi nuclear power plant (FNPP) that started 11 March 2011, the PG also at Kakioka, 150 km southwest from the FNPP, also dropped a by one order of magnitude. Unlike the past examples, the PG drop was two-stepped on 14 March and 20 March. Both correspond to two largest southward release of radioactive material according to the data from the radiation dose rate measurement network. We compare the Kakioka's PG data with the radiation dose rate data at different places to examine the fallout processes of both on 14 March and on 20 March. The former turned out to be dry contamination by surface wind, leaving a substantial amount of fallout floating near the ground. The latter turned out to be wet contamination by rain after transport by relatively low-altitude wind, and the majority of the fallout settled to the ground at this time. It is recommended that all nuclear power plant to have a network of PG observation surrounding the plant. Takeda, et al. (2011): Initial effect of the Fukushima accident on atmospheric electricity, Geophys. Res. Lett., 38, L15811, doi:10.1029/2011GL048511. Yamauchi, et al. (2012): Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement, Ann. Geophys., 30, 49-56, doi:10.5194/angeo-30-49-2012.

  14. The Effect of Air Density on Atmospheric Electric Fields Required for Lightning Initiation from a Long Airborne Object

    Science.gov (United States)

    Bazelyan, E. M.; Aleksandrov, N. L.; Raizer, Yu. Pl.; Konchankov, A. M.

    2006-01-01

    The purpose of the work was to determine minimum atmospheric electric fields required for lightning initiation from an airborne vehicle at various altitudes up to 10 km. The problem was reduced to the determination of a condition for initiation of a viable positive leader from a conductive object in an ambient electric field. It was shown that, depending on air density and shape and dimensions of the object, critical atmospheric fields are governed by the condition for leader viability or that for corona onset. To establish quantitative criteria for reduced air densities, available observations of spark discharges in long laboratory gaps were analyzed, the effect of air density on leader velocity was discussed and evolution in time of the properties of plasma in the leader channel was numerically simulated. The results obtained were used to evaluate the effect of pressure on the quantitative relationships between the potential difference near the leader tip, leader current and its velocity; based on these relationships, criteria for steady development of a leader were determined for various air pressures. Atmospheric electric fields required for lightning initiation from rods and ellipsoidal objects of various dimensions were calculated at different air densities. It was shown that there is no simple way to extend critical ambient fields obtained for some given objects and pressures to other objects and pressures.

  15. Energy Storage Systems for Electric Vehicles: Performance Comparison based on a Simple Equivalent Circuit and Experimental Tests

    OpenAIRE

    Concha Moreno-Torres, Pablo; Lafoz, M.; Vélez, P.; Rodríguez Arribas, Jaime

    2013-01-01

    The decision to select the most suitable type of energy storage system for an electric vehicle is always difficult, since many conditionings must be taken into account. Sometimes, this study can be made by means of complex mathematical models which represent the behavior of a battery, ultracapacitor or some other devices. However, these models are usually too dependent on parameters that are not easily available, which usually results in nonrealistic results. Besides, the more accurate the mo...

  16. Preparation of hierarchical porous carbon from waste printed circuit boards for high performance electric double-layer capacitors

    Science.gov (United States)

    Du, Xuan; Wang, Li; Zhao, Wei; Wang, Yi; Qi, Tao; Li, Chang Ming

    2016-08-01

    Renewable clean energy and resources recycling have become inevitable choices to solve worldwide energy shortages and environmental pollution problems. It is a great challenge to recycle tons of waste printed circuit boards (PCB) produced every year for clean environment while creating values. In this work, low cost, high quality activated carbons (ACs) were synthesized from non-metallic fractions (NMF) of waste PCB to offer a great potential for applications of electrochemical double-layer capacitors (EDLCs). After recovering metal from waste PCB, hierarchical porous carbons were produced from NMF by carbonization and activation processes. The experimental results exhibit that some pores were formed after carbonization due to the escape of impurity atoms introduced by additives in NMF. Then the pore structure was further tailored by adjusting the activation parameters. Roles of micropores and non-micropores in charge storage were investigated when the hierarchical porous carbons were applied as electrode of EDLCs. The highest specific capacitance of 210 F g-1 (at 50 mA g-1) and excellent rate capability were achieved when the ACs possessing a proper micropores/non-micropores ratio. This work not only provides a promising method to recycle PCB, but also investigates the structure tailoring arts for a rational hierarchical porous structure in energy storage/conversion.

  17. Harvesting vibrational energy with liquid-bridged electrodes: thermodynamics in mechanically and electrically driven RC-circuits

    CERN Document Server

    Janssen, Mathijs; van Roij, René

    2016-01-01

    We theoretically study a vibrating pair of parallel electrodes bridged by a (deformed) liquid droplet, which is a recently developed microfluidic device to harvest vibrational energy. The device can operate with various liquids, including liquid metals, electrolytes, as well as ionic liquids. We numerically solve the Young-Laplace equation for all droplet shapes during a vibration period, from which the time-dependent capacitance follows that serves as input for an equivalent circuit model. We first investigate two existing energy harvesters (with a constant and a vanishing bias potential), for which we explain an open issue related to their optimal electrode separations, which is as small as possible or as large as possible in the two cases, respectively. Then we propose a new engine with a time-dependent bias voltage, with which the harvested work and the power can be increased by orders of magnitude at low vibration frequencies and by factors 2-5 at high frequencies, where frequencies are to be compared to...

  18. Optimizing the operating parameters of corona electrostatic separation for recycling waste scraped printed circuit boards by computer simulation of electric field.

    Science.gov (United States)

    Li, Jia; Lu, Hongzhou; Liu, Shushu; Xu, Zhenming

    2008-05-01

    The printed circuit board (PCB) has a metal content of nearly 28% metal, including an abundance of nonferrous metals such as copper, lead, and tin. The purity of precious metals in PCBs is more than 10 times that of rich-content minerals. Therefore, the recycling of PCBs is an important subject, not only from the viewpoint of waste treatment, but also with respect to the recovery of valuable materials. Compared with traditional process the corona electrostatic separation (CES) had no waste water or gas during the process and it had high productivity with a low-energy cost. In this paper, the roll-type corona electrostatic separator was used to separate metals and nonmetals from scraped waste PCBs. The software MATLAB was used to simulate the distribution of electric field in separating space. It was found that, the variations of parameters of electrodes and applied voltages directly influenced the distribution of electric field. Through the correlation of simulated and experimental results, the good separation results were got under the optimized operating parameter: U=20-30 kV, L=L(1)=L(2)=0.21 m, R(1)=0.114, R(2)=0.019 m, theta(1)=20 degrees and theta(2)=60 degrees . PMID:17900802

  19. An assessment of alternatives for replacing Freon 113 in bench type electrical circuit board cleaning at Fermi National Accelerator Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Isakson, K.; Vessell, A.L.

    1994-07-01

    Fermilab is presently phasing out all solvents containing Freon-113 (CFC-113) as part of the continuing Waste Minimization Program. These solvents are used primarily in cleaning the flux off of electronic circuit boards after soldering, specifically in bench type work. Title VI of the Clean Air Act mandates a production phase-out for ozone depleting substances, like CFC-113, by the year 2000. Our study addresses this issue by evaluating and choosing alternative non-CFC solvents to replace the CFC-1 13 solvents at Fermilab. Several potential non-CFC cleaning solvents were tested. The evaluation took place in three parts: controlled experimental evaluation, chemical composition evaluation, and employee performed evaluation. First, we performed a controlled nine-step procedure with the potential solvents where each was evaluated in categories such as cleaning effectiveness, odor, residue, type of output and drying time. Next, we listed the chemical composition of each solvent. We noted which solvents contained hydrochlorofluorocarbons because they are targeted for phase-out in the future and will be recognized as interim solutions only. Finally, after preliminary testing, five solvents were chosen as the best options. These solvents were sent to be tested by Fermilab employees who use such materials. Their opinions are valuable not only because they are knowledgeable in this field, but also because they will be using the solvents chosen to replace the CFC-113 solvents. The results favored two ``best alternatives``: Safezone Solvent Flux Remover by Miller-Stephenson and E-Series CFC Free Flux-Off 2000 by Chemtech. Another possible solution also pursued is the no-clean solder option. In our study, we were not able to thoroughly investigate the many types of no-clean solders because of time and financial constraints. The testing that was done, however, showed that no-clean solder was a viable alternative in many cases.

  20. An assessment of alternatives for replacing Freon 113 in bench type electrical circuit board cleaning at Fermi National Accelerator Laboratory

    International Nuclear Information System (INIS)

    Fermilab is presently phasing out all solvents containing Freon-113 (CFC-113) as part of the continuing Waste Minimization Program. These solvents are used primarily in cleaning the flux off of electronic circuit boards after soldering, specifically in bench type work. Title VI of the Clean Air Act mandates a production phase-out for ozone depleting substances, like CFC-113, by the year 2000. Our study addresses this issue by evaluating and choosing alternative non-CFC solvents to replace the CFC-1 13 solvents at Fermilab. Several potential non-CFC cleaning solvents were tested. The evaluation took place in three parts: controlled experimental evaluation, chemical composition evaluation, and employee performed evaluation. First, we performed a controlled nine-step procedure with the potential solvents where each was evaluated in categories such as cleaning effectiveness, odor, residue, type of output and drying time. Next, we listed the chemical composition of each solvent. We noted which solvents contained hydrochlorofluorocarbons because they are targeted for phase-out in the future and will be recognized as interim solutions only. Finally, after preliminary testing, five solvents were chosen as the best options. These solvents were sent to be tested by Fermilab employees who use such materials. Their opinions are valuable not only because they are knowledgeable in this field, but also because they will be using the solvents chosen to replace the CFC-113 solvents. The results favored two ''best alternatives'': Safezone Solvent Flux Remover by Miller-Stephenson and E-Series CFC Free Flux-Off 2000 by Chemtech. Another possible solution also pursued is the no-clean solder option. In our study, we were not able to thoroughly investigate the many types of no-clean solders because of time and financial constraints. The testing that was done, however, showed that no-clean solder was a viable alternative in many cases

  1. Self-consistent stationary MHD shear flows in the solar atmosphere as electric field generators

    CERN Document Server

    Nickeler, D H; Wiegelmann, T; Kraus, M

    2014-01-01

    Magnetic fields and flows in coronal structures, for example, in gradual phases in flares, can be described by 2D and 3D magnetohydrostatic (MHS) and steady magnetohydrodynamic (MHD) equilibria. Within a physically simplified, but exact mathematical model, we study the electric currents and corresponding electric fields generated by shear flows. Starting from exact and analytically calculated magnetic potential fields, we solveid the nonlinear MHD equations self-consistently. By applying a magnetic shear flow and assuming a nonideal MHD environment, we calculated an electric field via Faraday's law. The formal solution for the electromagnetic field allowed us to compute an expression of an effective resistivity similar to the collisionless Speiser resistivity. We find that the electric field can be highly spatially structured, or in other words, filamented. The electric field component parallel to the magnetic field is the dominant component and is high where the resistivity has a maximum. The electric field ...

  2. Electrical principles 3 checkbook

    CERN Document Server

    Bird, J O

    2013-01-01

    Electrical Principles 3 Checkbook aims to introduce students to the basic electrical principles needed by technicians in electrical engineering, electronics, and telecommunications.The book first tackles circuit theorems, single-phase series A.C. circuits, and single-phase parallel A.C. circuits. Discussions focus on worked problems on parallel A.C. circuits, worked problems on series A.C. circuits, main points concerned with D.C. circuit analysis, worked problems on circuit theorems, and further problems on circuit theorems. The manuscript then examines three-phase systems and D.C. transients

  3. Integrated coherent matter wave circuits

    International Nuclear Information System (INIS)

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry

  4. HOW TO MAINTAIN SF6 CIRCUIT BREAKER

    OpenAIRE

    Snigdha Sharma, Hemant bharadwaj,

    2012-01-01

    India’s growing economy needs an efficient powertransmission system to meet the increasing demand forreliable and affordable power. Circuit breakers play animportant role in protection system of electrical powertransmission networks. A circuit breaker is anautomatically operated electrical switch which detects afault condition and interrupt immediately todiscontinue electrical flow. So its maintenance deservesspecial considerations in order to prevent theequipments an...

  5. X-ray emission from a nanosecond-pulse discharge in an inhomogeneous electric field at atmospheric pressure

    International Nuclear Information System (INIS)

    This paper describes experimental studies of the dependence of the X-ray intensity on the anode material in nanosecond high-voltage discharges. The discharges were generated by two nanosecond-pulse generators in atmospheric air with a highly inhomogeneous electric field by a tube-plate gap. The output pulse of the first generator (repetitive pulse generator) has a rise time of about 15 ns and a full width at half maximum of 30–40 ns. The output of the second generator (single pulse generator) has a rise time of about 0.3 ns and a full width at half maximum of 1 ns. The electrical characteristics and the X-ray emission of nanosecond-pulse discharge in atmospheric air are studied by the measurement of voltage-current waveforms, discharge images, X-ray count and dose. Our experimental results showed that the anode material rarely affects electrical characteristics, but it can significantly affect the X-ray density. Comparing the density of X-rays, it was shown that the highest x-rays density occurred in the diffuse discharge in repetitive pulse mode, then the spark discharge with a small air gap, and then the corona discharge with a large air gap, in which the X-ray density was the lowest. Therefore, it could be confirmed that the bremsstrahlung at the anode contributes to the X-ray emission from nanosecond-pulse discharges.

  6. Using an optical fibre anemometer to measure the speed of the electric wind in a negative polarity, atmospheric corona discharge

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, A; Lamb, D W [Physics and Electronics, School of Biological, Biomedical and Molecular Sciences, University of New England, Armidale, NSW 2351 (Australia)

    2005-01-01

    Coronas are partial discharges that occur in regions of non-uniform electric fields adjacent to conductors stressed to high voltages. Negative, Trichel-pulse coronas in air occur when a dc, negative-polarity, high voltage is applied to a conductor. Trichel pulses in atmospheric air generate significant amounts of ozone as well as electrical and acoustic noise. Under the right conditions these coronas can be a precursor to complete electrical breakdown of the air gap due to a reduction in the density of neutral molecules resulting from a combination of localised heating and convective air flow generated by the movement of negative ions. An optical fibre anemometer, based on a Mach-Zehnder interferometer has been constructed to measure the speed of the wind generated in the point-plane gap of a negative, Trichel-pulse corona discharge in atmospheric air. The sensing arm of the fibre interferometer is subjected to controlled, repetitive bursts of infrared radiation from a CO{sub 2} laser and the combination of localised heating and convective cooling by the corona wind results in fringe shifts which are directly calibrated to the speed of the wind. This paper reports on the nature of the calibration process and presents some radial profiles of wind speed in the corona gap.

  7. Using an optical fibre anemometer to measure the speed of the electric wind in a negative polarity, atmospheric corona discharge

    International Nuclear Information System (INIS)

    Coronas are partial discharges that occur in regions of non-uniform electric fields adjacent to conductors stressed to high voltages. Negative, Trichel-pulse coronas in air occur when a dc, negative-polarity, high voltage is applied to a conductor. Trichel pulses in atmospheric air generate significant amounts of ozone as well as electrical and acoustic noise. Under the right conditions these coronas can be a precursor to complete electrical breakdown of the air gap due to a reduction in the density of neutral molecules resulting from a combination of localised heating and convective air flow generated by the movement of negative ions. An optical fibre anemometer, based on a Mach-Zehnder interferometer has been constructed to measure the speed of the wind generated in the point-plane gap of a negative, Trichel-pulse corona discharge in atmospheric air. The sensing arm of the fibre interferometer is subjected to controlled, repetitive bursts of infrared radiation from a CO2 laser and the combination of localised heating and convective cooling by the corona wind results in fringe shifts which are directly calibrated to the speed of the wind. This paper reports on the nature of the calibration process and presents some radial profiles of wind speed in the corona gap

  8. Demonstrations with an "LCR" Circuit

    Science.gov (United States)

    Kraftmakher, Yaakov

    2011-01-01

    The "LCR" circuit is an important topic in the course of electricity and magnetism. Papers in this field consider mainly the forced oscillations and resonance. Our aim is to show how to demonstrate the free and self-excited oscillations in an "LCR" circuit. (Contains 4 figures.)

  9. Postirradiation Effects In Integrated Circuits

    Science.gov (United States)

    Shaw, David C.; Barnes, Charles E.

    1993-01-01

    Two reports discuss postirradiation effects in integrated circuits. Presents examples of postirradiation measurements of performances of integrated circuits of five different types: dual complementary metal oxide/semiconductor (CMOS) flip-flop; CMOS analog multiplier; two CMOS multiplying digital-to-analog converters; electrically erasable programmable read-only memory; and semiconductor/oxide/semiconductor octal buffer driver.

  10. Currents in the cometary atmosphere

    Science.gov (United States)

    Ip, W.-H.

    1979-01-01

    If the structure of the magnetic field and electric current in the cometary type I tail can be represented by an electric current circuit, disruption of the cross-tail current system may lead to a current discharging through the cometary ionosphere, and the dissipation of the magnetic energy stored in the tail. From the point of view of energy budget, a tail-aligned magnetic field on the order of 10 gamma will be sufficient to produce a strong ionization effect of the cometary atmosphere.

  11. Layout of Controller Switch Circuit of Power Driver of Electric Motor Car%电动车电机控制器功率驱动开关电路设计方案

    Institute of Scientific and Technical Information of China (English)

    李中望

    2013-01-01

    The performance of electric motor car depends on the design of electric motor controller. The switch circuit of power driver is the important module of the entire controller. Its design will directly determine the running state of electric motor car.%电动车性能的优劣取决于电机控制器的整体设计方案,而功率驱动开关电路则是整个控制器的重要组成模块,它的设计将直接决定车辆的运行状态。

  12. Electricity shock: after early short-circuits spit out dizzy price peaks, new rules impose order on Alberta's power market

    International Nuclear Information System (INIS)

    The brief account is given of the trials and tribulations of deregulated electric power in Alberta. Although deregulation did not take effect until January 1, 2001, the early warning flags of trouble ahead had popped up as early as the fall of 1999, as well as last summer when unplanned generating outages caused the monthly average pool price to spike to more than 6.6. cents/kWh despite assurances from the government that consumers would be spared any substantial rate hikes and would not be left to navigate the free market alone and forgotten. (The historical average price prior to deregulation was between two and three cents per kilowatt hour). The Alberta government refused to heed pleas for abandoning the move to a competitive market, or at least to delay its implementation; instead, has decided to offer rebates to individual customers as well as industrial clients, and to impose a cap of 11 cents per kilowatt hour on consumer rates. (Early in January 2001, the pool price averaged just under 12 cent /kWh, down from the December 2000 average of 19 cents and the October high of 25.3 cents per kWh). The government is convinced that with several new generation projects coming on stream soon, prices will come down to manageable levels. The tough new trading rules that came into effect last fall are also expected to do their part in closing the loopholes which allowed the creation of significant misleading price spikes and fluctuations. The new rules will penalize a 'price taker' for the remainder of the trading day and by so doing it is expected to result in more disciplined offers and reduce intra-day price volatility. As an added measure to increase discipline, the Pool also moved to prevent price blocks of less than 25 MW from becoming eligible to set the Pool price

  13. Electrical Characteristics of Dielectric-Barrier Discharges in Atmospheric Pressure Air Using a Power-Frequency Voltage Source

    International Nuclear Information System (INIS)

    Dielectric-barrier discharges (DBDs) in atmospheric pressure air have been studied by using a power-frequency voltage source. In this paper the electrical characteristics of DBDs using glass and alumina dielectrics have been investigated experimentally. According to the Lissajous figures of voltage-charges, it is discovered that the discharge power for an alumina dielectric is much higher than that for a glass dielectric at the same applied voltage. Also, the voltage-current curves of the glass and alumina dielectrics confirm the fact that the dielectric barriers behave like semiconducting materials at certain applied voltages. (low temperature plasma)

  14. Meteorological influences on atmospheric radioactivity and its effects on the electrical environment

    International Nuclear Information System (INIS)

    The 222Rn content of soil gas is influenced by meteorological parameters and especially by wind speed. For 220Rn the effects are less pronounced. The exhalation of 220Rn is dependent on precipitation and atmospheric turbulence. From horizontal measurements of radioactivity in the air, the most representative values are obtained under unstable, near-neutral, and light stable stratifications. The concentration of natural radioactivity at a point in the atmospheric surface layer can be expressed in terms of atmospheric stability if the horizontal distributions are fairly homogeneous. For longtime variations of radioactivity in the air, the precipitation and groundwater conditions are of prime concern. But for the rapid fluctuations the turbulent processes give the main contribution to the variations

  15. Analysis of atmospheric aerosols by atomic emission spectrometry with electrical discharge sampling

    International Nuclear Information System (INIS)

    A procedure is developed for the determination of the concentration of heavy metals (Pb, Mn, Cu, Ni, Zn, and Cd) in atmospheric air by atomic emission spectrometry with gas-discharge sampling onto the end of a standard carbon electrode. A design of a two-section sampler is proposed; the sampler provides the rapid determination of deposition factors for the deposition of heavy metals contained in aerosol particles onto the end of a carbon electrode. Examples of determining metal concentrations in a model sample of air and in atmospheric air and determination limits of metals deposited onto the end of a carbon electrode are given

  16. A comparison of gold versus silver electrode contacts for high-resolution gastric electrical mapping using flexible printed circuit board arrays

    International Nuclear Information System (INIS)

    Stomach contractions are initiated and coordinated by electrical events termed slow waves, and slow wave abnormalities contribute to gastric motility disorders. Recently, flexible printed circuit board (PCB) multi-electrode arrays were introduced, facilitating high-resolution mapping of slow wave activity in humans. However PCBs with gold contacts have shown a moderately inferior signal quality to previous custom-built silver-wire platforms, potentially limiting analyses. This study determined if using silver instead of gold contacts improved flexible PCB performance. In a salt-bath test, modestly higher stimulus amplitudes were recorded from silver PCBs (mean 312, s.d. 89 µV) than those from gold (mean 281, s.d. 85 µV) (p < 0.001); however, the signal-to-noise ratio (SNR) was similar (p = 0.26). In eight in vivo experimental studies, involving gastric serosal recordings from five pigs, no silver versus gold differences were found in terms of slow wave amplitudes (mean 677 versus 682 µV; p = 0.91), SNR (mean 8.8 versus 8.8 dB; p = 0.94) or baseline drift (NRMS; mean 12.0 versus 12.1; p = 0.97). Under the prescribed conditions, flexible PCBs with silver or gold contacts provide comparable results in vivo, and contact material difference does not explain the performance difference between current-generation slow wave mapping platforms. Alternative explanations for this difference and the implications for electrode design are discussed. (note)

  17. An overview of the lightning and atmospheric electricity observations collected in southern France during the HYdrological cycle in Mediterranean EXperiment (HyMeX), Special Observation Period 1

    OpenAIRE

    Defer, E.; Pinty, J.-P.; S. Coquillat; Martin, J.-M.; S. Prieur; S. Soula; E. Richard; Rison, W.; P. Krehbiel; Thomas, R; D. Rodeheffer; Vergeiner, C.; F. Malaterre; S. Pedeboy; SCHULZ, W

    2015-01-01

    The PEACH project (Projet en Electricité Atmosphérique pour la Campagne HyMeX – the Atmospheric Electricity Project of the HyMeX Program) is the atmospheric electricity component of the Hydrology cycle in the Mediterranean Experiment (HyMeX) experiment and is dedicated to the observation of both lightning activity and electrical state of continental and maritime thunderstorms in the area of the Mediterranean Sea. During the HyMeX SOP1 (Special Observation Period) from 5 Sept...

  18. Evaluation of atmospheric corrosion on electroplated zinc and zinc nickel coatings by Electrical Resistance (ER) Monitoring

    DEFF Research Database (Denmark)

    Møller, Per

    ER (Electrical Resistance) probes provide a measurement of metal loss, measured at any time when a metal is exposed to the real environment. The precise electrical resistance monitoring system can evaluate the corrosion to the level of nanometers, if the conductivity is compensated for temperature...... cars for the automotive industry, off-shore construction or component and devices used in harsh industrial environments. The ER monitoring makes it possible to study the corrosion rate on-line in remote locations as a function of temperature, relative humidity and changes in the composition of the...

  19. 49 CFR 236.731 - Controller, circuit.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Controller, circuit. A device for opening and closing electric circuits....

  20. 49 CFR 236.726 - Circuit, track.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, track. An electrical circuit of which the rails of the track form a part....

  1. 30 CFR 56.6407 - Circuit testing.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit testing. 56.6407 Section 56.6407... Blasting § 56.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing blasting circuits shall be used to test each of the following: (a) Continuity of each electric detonator...

  2. 30 CFR 75.1323 - Blasting circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Blasting circuits. 75.1323 Section 75.1323... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made...

  3. Fire protection electrical engineering

    International Nuclear Information System (INIS)

    This book concentrates of electricity with current, voltage, power, ohms law, access of resistance, electrolytic analysis and battery, static on frictional electricity and electrostatic induction, coulomb's law, Gauss's law, condenser and capacity, magmatism on magnetic field and magnetic line of force, magnetic circuit, electromagnetic force, electromotive current, basic alternating current circuit, circuit network analysis, three-phase current, non-sinusoidal alternating current, transient phenomena, semiconductor, electric measurement on measurement over resistance, power, power rate and circuit tester, automatic control on introduction, term, classification, foundation of sequence control, logic circuit and basic logic circuit and electric equipment.

  4. Effects of the Chernobyl and Fukushima nuclear accidents on atmospheric electricity parameters recorded at Polish observation stations

    Science.gov (United States)

    Kubicki, Marek; Baranski, Piotr; Odzimek, Anna; Michnowski, Stanislaw; Myslek-Laurikainen, Bogna

    2013-04-01

    We analyse the atmospheric electricity parameters, measured at Polish geophysical stations in Swider, Poland, and Hornsund, Spitsbergen, in connection with the radioactive incident in Fukushima, Japan, beginning on 11 March 2011, following the 9.0 earthquake and tsunami. We compare our results with the situation during and after the Chernobyl disaster on April 26, 1986, when the radioactive fallout detected at Swider increased in the last week of April 1986, from 4.111 to 238.7 Bq/m2 and up to 967.0 Bq/m2 in the second week of May 1986 - what was more than 235 times greater than the values measured prior to that accident. Besides the electric field especially the electric conductivity is very sensitive to the radioactive contamination of the air. Thus we postulate that these two measurements should be run at geophysical stations over the world and used as a relatively simple and low-cost tool for continuous monitoring of possible hazard caused by nuclear power plant accidents.

  5. Spatial distribution of the electrical potential and ion concentration in the downstream area of atmospheric pressure remote plasma

    Directory of Open Access Journals (Sweden)

    M. V. Mishin

    2014-10-01

    Full Text Available This paper presents the results from an experimental study of the ion flux characteristics behind the remote plasma zone in a vertical tube reaction chamber for atmospheric pressure plasma enhanced chemical vapor deposition. Capacitively coupled radio frequency plasma was generated in pure He and gas mixtures: He–Ar, He–O2, He–TEOS. We previously used the reaction system He–TEOS for the synthesis of self-assembled structures of silicon dioxide nanoparticles. It is likely that the electrical parameters of the area, where nanoparticles have been transported from the synthesis zone to the substrate, play a significant role in the self-organization processes both in the vapor phase and on the substrate surface. The results from the spatial distribution of the electrical potential and ion concentration in the discharge downstream area measured by means of the external probe of original design and the special data processing method are demonstrated in this work. Positive and negatives ions with maximum concentrations of 106–107 cm−3 have been found at 10–80 mm distance behind the plasma zone. On the basis of the revealed distributions for different gas mixtures, the physical model of the observed phenomena is proposed. The model illustrates the capability of the virtual ion emitter formation behind the discharge gap and the presence of an extremum of the electrical potential at the distance of approximately 10−2–10−1 mm from the grounded electrode.

  6. Optical diagnostics of the hollow needle to plate electrical discharge in air at atmospheric pressure

    Czech Academy of Sciences Publication Activity Database

    Pekárek, S.; Šimek, Milan

    2004-01-01

    Roč. 54, suppl. C (2004), C728-C734. ISSN 0011-4626. [Symposium on Plasma Physics and Technology /21./. Praha, 14.06.2004-17.06.2004] R&D Projects: GA AV ČR IAA1043403 Institutional research plan: CEZ:AV0Z2043910 Keywords : optical diagnostics, electrical discharge, ozone generation Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.292, year: 2004

  7. Mass and elemental distributions of atmospheric particles nearby blast furnace and electric arc furnace operated industrial areas in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Mohiuddin, Kazi, E-mail: kazi.mohiuddin@students.mq.edu.au [Graduate School of the Environment, Department of Environment and Geography, Faculty of Science, Macquarie University, NSW (Australia); Strezov, Vladimir; Nelson, Peter F. [Graduate School of the Environment, Department of Environment and Geography, Faculty of Science, Macquarie University, NSW (Australia); Stelcer, Eduard [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Evans, Tim [Graduate School of the Environment, Department of Environment and Geography, Faculty of Science, Macquarie University, NSW (Australia)

    2014-07-01

    The improved understanding of mass and elemental distributions of industrial air particles is important due to their heterogeneous atmospheric behaviour and impact on human health and the environment. In this study, particles of different size ranges were collected from three sites in Australia located in the vicinity of iron and steelmaking industries and one urban background site with very little industrial influence. In order to determine the importance of the type of industrial activity on the urban atmospheric quality, the industrial sites selected in this study were in the close proximity to two blast furnace operated and one electric arc furnace based steelmaking sites. The chemical compositions of the collected air particles were analysed using the proton induced X-ray emission (PIXE) technique. This study revealed significantly higher metal concentrations in the atmospheric particles collected in the industrial sites, comparing to the background urban site, demonstrating local influence of the industrial activities to the air quality. The modality types of the particles were found to be variable between the mass and elements, and among elements in the urban and industrial areas indicating that the elemental modal distribution is as important as particle mass for particle pollution modelling. The highest elemental number distribution at all studied sites occurred with particle size of 0.1 μm. Iron was found as the main dominant metal at the industrial atmosphere in each particle size range. The industrial Fe fraction in the submicron and ultrafine size particles was estimated at up to 95% which may be released from high temperature industrial activities with the iron and steelmaking industries being one of the major contributors. Hence, these industrial elemental loadings can highly influence the atmospheric pollution at local urban and regional levels and are required to consider in the atmospheric modelling settings. - Highlights: • Urban and

  8. Mass and elemental distributions of atmospheric particles nearby blast furnace and electric arc furnace operated industrial areas in Australia

    International Nuclear Information System (INIS)

    The improved understanding of mass and elemental distributions of industrial air particles is important due to their heterogeneous atmospheric behaviour and impact on human health and the environment. In this study, particles of different size ranges were collected from three sites in Australia located in the vicinity of iron and steelmaking industries and one urban background site with very little industrial influence. In order to determine the importance of the type of industrial activity on the urban atmospheric quality, the industrial sites selected in this study were in the close proximity to two blast furnace operated and one electric arc furnace based steelmaking sites. The chemical compositions of the collected air particles were analysed using the proton induced X-ray emission (PIXE) technique. This study revealed significantly higher metal concentrations in the atmospheric particles collected in the industrial sites, comparing to the background urban site, demonstrating local influence of the industrial activities to the air quality. The modality types of the particles were found to be variable between the mass and elements, and among elements in the urban and industrial areas indicating that the elemental modal distribution is as important as particle mass for particle pollution modelling. The highest elemental number distribution at all studied sites occurred with particle size of 0.1 μm. Iron was found as the main dominant metal at the industrial atmosphere in each particle size range. The industrial Fe fraction in the submicron and ultrafine size particles was estimated at up to 95% which may be released from high temperature industrial activities with the iron and steelmaking industries being one of the major contributors. Hence, these industrial elemental loadings can highly influence the atmospheric pollution at local urban and regional levels and are required to consider in the atmospheric modelling settings. - Highlights: • Urban and

  9. Effects of annealing atmosphere on crystallization and electrical properties in BiFeO3 thin films by chemical solution deposition(CSD)

    International Nuclear Information System (INIS)

    BiFeO3 (BFO) thin films have been prepared on platinized silicon substrates by chemical solution deposition (CSD) and annealed at 600 .deg. C for 1 hour under various atmospheres, i.e., O2, Air and N2. Effects of annealing atmospheres on the crystallization and electrical properties of BFO films were investigated. Crystallization behavior and electrical properties of BFO films depend on the oxygen partial pressure of the annealing atmosphere. The BFO thin film annealed in N2 atmosphere showed a good crystallinity. The surface roughness of the BFO film decreased with lowering oxygen partial pressure of the annealing atmosphere. Low leakage current density and P-E hysteresis were found only in the BFO film annealed at 600 .deg. C under N2 atmosphere. Leakage current density, polarization (at zero electric field) and electric field (at zero polarization) of the BFO film annealed at 600 .deg. C under N2 are 5 x 10-7 A/cm2 at 1 V, 0.2 μC/cm2 and 15kV/cm, respectively

  10. 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

  11. Evaluation of atmospheric corrosion on electroplated zinc and zinc nickel coatings by Electrical Resistance (ER) Monitoring

    DEFF Research Database (Denmark)

    Møller, Per

    2013-01-01

    cars for the automotive industry, off-shore construction or component and devices used in harsh industrial environments. The ER monitoring makes it possible to study the corrosion rate on-line in remote locations as a function of temperature, relative humidity and changes in the composition of the...... and magnetic fields. With this technique very important information about the durability of a new conversion coatings for aluminum, zinc and zinc alloys exposed to unknown atmospheric conditions can be gathered. This is expected to have a major impact on a number of industrial segments, such as test...

  12. Circuito eléctrico equivalente de una vesícula sináptica Electric Circuit Equivalent to a Synaptic Vesicle

    Directory of Open Access Journals (Sweden)

    Cortés Xaira

    2003-06-01

    Full Text Available En el presente trabajo se desarrolla un modelo eléctrico de uno de los elementosprimordiales en la sinapsis nerviosa: la vesícula sináptica. Dicha vesícula se consideracomo un organelo esferoidal, despojada de neurotransmisores y se asume, además, quesu lumen, su membrana y el citoplasma neuronal se comportan como medios lineales,homogéneos e isotrópicos caracterizados por conductividades y permitividades especí-ficas. El método utilizado será la aplicación teórica de un campo eléctrico (que varía enel tiempo a bajas frecuencias sobre esta vesícula, lo que induce a través de su membra-na una diferencia de potencial cuya caracterización se obtiene a partir de las ecuacionesde Maxwell sometidas a condiciones de contorno adecuadas, en la denominada aproxi-mación cuasi-estacionaria. A su vez, mediante aplicación de la Transformada de Laplacea las expresiones resultantes se obtiene la FUNCIÓN DE TRANSFERENCIA, que condu-ce a sintetizar un circuito RLC equivalente de la vesícula en estudio. El modelo predicevalores de capacitancia para vesículas esféricas individuales que, al ser contrastados conlos que presenta la literatura existente derivada de procesos experimentales previos,alienta la perseverancia en este enfoque teórico germinal.In the present work an electrical model of the synaptic vesicle is developed. The vesicleis considered as a spheroidal organelle without neurotransmitters in its inner space. Inaddition, its lumen, its membrane and the neuronal cytoplasm behave like linear,homogenous and isotropic media characterized by specific conductivities and permi-tivities. The theoretical approach considers the application of an electric field (varying intime at low frequencies on this vesicle. A transmembrane potential difference is inducedand its characterization is obtained from Maxwell's equations subject to appropriateboundary conditions, in the so-called quasi-stationary approach. By applying theLaplace Transform to

  13. Atmospheric electric field anomalies associated with solar flare/coronal mass ejection events and solar energetic charged particle "Ground Level Events"

    Directory of Open Access Journals (Sweden)

    E. A. Kasatkina

    2009-10-01

    Full Text Available We discuss the fair weather atmospheric electric field signatures of three major solar energetic charged particle events which occurred in on 15 April 2001, 18 April and 4 November, and their causative solar flares/coronal mass ejections (SF/CMEs. Only the 15 April 2001 shows clear evidence for Ez variation associated to SF/CME events and the other two events may support this hypothesis as well although for them the meteorological data were not available. All three events seem to be associated with relativistic solar protons (i.e. protons with energies >450 MeV of the Ground Level Event (GLE type. The study presents data on variations of the vertical component of the atmospheric electric field (Ez measured at the auroral station Apatity (geomagnetic latitude: 63.8°, the polar cap station Vostok (geomagnetic latitude: −89.3° and the middle latitude stations Voyeikovo (geomagnetic latitude: 56.1° and Nagycenk (geomagnetic latitude: 47.2°. A significant disturbance in the atmospheric electric field is sometimes observed close to the time of the causative solar flare; the beginning of the electric field perturbation at Apatity is detected one or two hours before the flare onset and the GLE onset. Atmospheric electric field records at Vostok and Voyeikovo show a similar disturbance at the same time for the 15 April 2001 event. Some mechanisms responsible for the electric field perturbations are considered.

  14. Electrical and electronic principles

    CERN Document Server

    Knight, SA

    1988-01-01

    Electrical and Electronic Principles, 3 focuses on the principles involved in electrical and electronic circuits, including impedance, inductance, capacitance, and resistance.The book first deals with circuit elements and theorems, D.C. transients, and the series circuits of alternating current. Discussions focus on inductance and resistance in series, resistance and capacitance in series, power factor, impedance, circuit magnification, equation of charge, discharge of a capacitor, transfer of power, and decibels and attenuation. The manuscript then examines the parallel circuits of alternatin

  15. Effect of Antihypertensive Errors of Secondary Circuit Voltage on the Electric Power Metering%电压二次回路压降误差对供电线路电能计量的影响

    Institute of Scientific and Technical Information of China (English)

    成钢

    2014-01-01

    电能计量装置由电能表、电流电压互感器及其二次回路构成。电能计量装置的综合误差包括:电能表的误差r0、互感器的合成误差着P、电压互感器二次回路电压降引起的合成误差rd。因此,电能计量装置的综合误差为:r=r0+着P+rd(豫)。%Electric energy metering device is constituted of Watt-hour meter, electric current and voltage transformer and secondary circuit. The composite error of electric energy metering comes from error of electric energy meter (r0), combination of transformer (εP), the voltage decrease from secondary circuit of voltage transformer (rd). As a result, the composite error of electric energy metering device is:r=r0+εP+rd (%).

  16. LC-Circuit Calorimetry

    CERN Document Server

    Bossen, Olaf

    2011-01-01

    We present a new type of calorimeter in which we couple an unknown heat capacity with the aid of Peltier elements to an electrical circuit. The use of an electrical inductance and an amplifier in the circuit allows us to achieve autonomous oscillations, and the measurement of the corresponding resonance frequency makes it possible to accurately measure the heat capacity with an intrinsic statistical error that decreases as ~t^{-3/2} with measuring time t, as opposed to a corresponding error ~t^{-1/2} in the conventional alternating current (a.c.) method to measure heat capacities. We have built a demonstration experiment to show the feasibility of the new technique, and we have tested it on a gadolinium sample at its transition to the ferromagnetic state.

  17. Electrical Characterization of Dielectric Barrier Discharge in Atmospheric Air for Plasma Production Aiming for Improving Seed Germination

    International Nuclear Information System (INIS)

    A Dielectric Barrier Discharge (DBD) reactor has been developed aiming for improving seed germination. This DBD reactor consists of two 3-inch stainless steel planar electrodes with mylar sheets as dielectric barriers. An adjustable frequency AC high voltage power supply is then connected to the DBD reactor in order to generate plasma. The gas gap of DBD can be varied up to 3 mm when operating in atmospheric air. The electrical characterization of this DBD such as power, current, etc., together with optical emission characterization of plasma generated with this DBD will be presented. This information will be essential toward a development in order for applying plasma to small seeds, such as tomato, rice, chili, etc. to improve seed germination as inspired by the work of Bozena Sera et al (IEEE Trans. Plasma Sci., vol. 38, no. 10, p.2963).

  18. Atmospheric corrosion Monitoring with Time-of-Wetness (TOW) sensor and Thin Film Electric Resistance (TFER) sensor

    International Nuclear Information System (INIS)

    In this study, TOW sensor was fabricated with the same P. J. Serada's in NRC and was evaluated according to pollutant amount and wet/dry cycle. Laboratorily fabricated thin film electric resistance (TFER) probes were applied in same environment for the measurement of corrosion rate for feasibility. TOW sensor could not differentiate the wet and dry time especially at polluted environment like 3.5% NaCl solution. This implies that wet/dry time monitoring by means of TOW sensor need careful application on various environment. TFER sensor could produce instant atmospheric corrosion rate regardless of environment condition. And corrosion rate obtained by TFER sensor could be differentiated according to wet/dry cycle, wet/dry cycle time variation and solution chemistry. Corrosion behaviors of TFER sensor showed that corrosion could proceed even after wet cycle because of remained electrolyte at the surface

  19. Atmospheric Pressure Ion Source Development: Experimental Validation of Simulated Ion Trajectories within Complex Flow and Electrical Fields

    Science.gov (United States)

    Wissdorf, Walter; Lorenz, Matthias; Pöhler, Thorsten; Hönen, Herwart; Benter, Thorsten

    2013-10-01

    Three-dimensionally (3D) resolved ion trajectory calculations within the complex viscous flow field of an atmospheric pressure ion source are presented. The model calculations are validated with spatially resolved measurements of the relative sensitivity distribution within the source enclosure, referred to as the distribution of ion acceptance (DIA) of the mass analyzer. In previous work, we have shown that the DIA shapes as well as the maximum signal strengths strongly depend on ion source operational parameters such as gas flows and temperatures, as well as electrical field gradients established by various source electrode potentials (e.g., capillary inlet port potential and spray shield potential). In all cases studied, distinct, reproducible, and, to some extent, surprising DIA patterns were observed. We have thus attempted to model selected experimental operational source modes (called operational points) using a validated computational flow dynamics derived 3D-velocity field as an input parameter set for SIMION/SDS, along with a suite of custom software for data analysis and parameter set processing. Despite the complexity of the system, the modeling results reproduce the experimentally derived DIA unexpectedly well. It is concluded that SIMION/SDS in combination with accurate computational fluid dynamics (CFD) input data and adequate analysis software is capable of successfully modeling operational points of an atmospheric pressure ion (API) source. This approach should be very useful in the computer-aided design of future API sources.

  20. Optimal design of an atmospheric water generator (AWG) based on thermo-electric cooler (TEC) for drought in rural area

    Science.gov (United States)

    Suryaningsih, Sri; Nurhilal, Otong

    2016-02-01

    Drinking water availability is a major issue in some rural area in Indonesia during the summer season due to lack of rainfall, which peoples in this area have to fetch the water a few kilometers away from home. The Atmospheric Water Generator (AWG) is one of the alternative solution for fresh water recovery from atmosphere which is directly condensed the moisture content of water vapor from the air. This paper presents the method to develop a prototype of an AWG based on Thermo-electric cooler (TEC) that used 12 Volt DC, hence its suitability for using renewable energy resource. Computational Fluid Dynamics (CFD) is utilized to optimize the design process in the flow region only, it's not suitable for recent CFD software to use in Multi physics, because inaccuracy, cost and time saving. Some parameters such as temperature, moisture content, air flow, pressure, form of air flow channel and the water productivity per unit input of energy are to be considered. The result is presented as an experimental prototype of an AWG based on TEC and compared with other conventional commercial products.

  1. NH3/TMI molar ratio dependence of electrical and optical properties for atmospheric-pressure MOVPE InN

    International Nuclear Information System (INIS)

    The electrical and optical properties for atmospheric-pressure MOVPE InN have been studied as a function of NH3/TMI molar ratio during the growth. Residual carrier (electron) concentration is decreased with increasing NH3/TMI molar ratio. PL peak energy is also shifted to a low energy side with increasing NH3/TMI molar ratio. Hall mobility of InN is almost independent on NH3/TMI molar ratio and is rather decreased at a high NH3/TMI molar ratio. The highest mobility is obtained for a sample grown at a relatively low NH3/TMI molar ratio. The grain size of the InN films is decreased with increasing NH3/TMI molar ratio. The lowest carrier concentration of 4.5 x 1018 cm-3 and highest mobility of 1100 cm2/Vs obtained here are the best data for MOVPE InN ever reported. Based on these results, the most probable candidate for donors and the dominant carrier-scattering mechanism for atmospheric-pressure MOVPE InN are discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Behaviour of non-metallic inclusions during electric-arc heating in argon-hydrogen atmosphere

    International Nuclear Information System (INIS)

    Conditions of steel refining by a high-temperature hydrogen-containing gas are studied experimentally. Armco-iron with different content of silicon or aluminium served as a source mareterial as well as corrosion resistant steel 12Kh18N10T. It permits to have in metals inclusions of a definite type (Al2O3; SiO2; TiN and others). Growth of alloy refining by oxygen and deoxidation products during electric - arc heating, when hydrogen being introduced into the inerti gas, is shown to be mainly connected with intensity rise in metal melt mixing during hydrogen boiling in case of iron remelting, deoxidized by aluminium, and with chemical interaction with hydrogen in case of iron remelting deoxidized bu silicon

  3. Electrical and optical properties of thin indium tin oxide films produced by pulsed laser ablation in oxygen or rare gas atmospheres

    DEFF Research Database (Denmark)

    Thestrup, B.; Schou, Jørgen; Nordskov, A.;

    1999-01-01

    Films of indium tin oxide (ITO) have been produced in different background gases by pulsed laser deposition (PLD). The Films deposited in rare gas atmospheres on room temperature substrates were metallic, electrically conductive, but had poor transmission of visible light. For substrate temperatu......Films of indium tin oxide (ITO) have been produced in different background gases by pulsed laser deposition (PLD). The Films deposited in rare gas atmospheres on room temperature substrates were metallic, electrically conductive, but had poor transmission of visible light. For substrate...

  4. Electrical and spectroscopic analysis of mono- and multi-tip pulsed corona discharges in air at atmospheric pressure

    International Nuclear Information System (INIS)

    This work is devoted to the analysis of experimental results obtained in dry air at atmospheric pressure in a positive point-to-plane corona discharge under a pulsed applied voltage in the cases of anodic mono- and multi-tips. In the mono-tip case, the peak corona current is analysed as a function of several experimental parameters such as magnitude, frequency and duration of pulsed voltage and gap distance. The variation of the corona discharge current is correlated with the ozone production. Then in the multi-tip case, the electrical behaviour is analysed as a function of the distance between two contiguous tips and the tip number in order to highlight the region of creation active species for the lowest dissipated power. Intensified charge-coupled device pictures and electric field calculations as a function of inter-tip distance are performed to analyse the mutual effect between two contiguous tips. The optical emission spectra are measured in the UV–visible–NIR wavelength range between 200 nm and 800 nm, in order to identify the main excited species formed in an air corona discharge such as the usual first and second positive systems with first negative systems of molecular nitrogen. The identification of atomic species (O triplet and N) and the quenching of NOγ emission bands are also emphasized.

  5. Atmospheric doping effects in epitaxial graphene: correlation of local and global electrical studies

    Science.gov (United States)

    Panchal, Vishal; Giusca, Cristina E.; Lartsev, Arseniy; Martin, Nicholas A.; Cassidy, Nathan; Myers-Ward, Rachael L.; Gaskill, D. Kurt; Kazakova, Olga

    2016-03-01

    We directly correlate the local (20 nm scale) and global electronic properties of a device containing mono-, bi- and tri-layer epitaxial graphene (EG) domains on 6H -SiC(0001) by simultaneously performing local surface potential measurements using Kelvin probe force microscopy and global transport measurements. Using well-controlled environmental conditions we investigate the doping effects of N2, O2, water vapour and NO2 at concentrations representative of the ambient air. We show that presence of O2, water vapour and NO2 leads to p-doping of all EG domains. However, the thicker layers of EG are significantly less affected. Furthermore, we demonstrate that the general consensus of O2 and water vapour present in ambient air providing majority of the p-doping to graphene is a common misconception. We experimentally show that even the combined effect of O2, water vapour, and NO2 at concentrations higher than typically present in the atmosphere does not fully replicate p-doping from ambient air. Thus, for EG gas sensors it is essential to consider naturally occurring environmental effects and properly separate them from those coming from targeted species.

  6. Demultiplexer circuit for neural stimulation

    Science.gov (United States)

    Wessendorf, Kurt O; Okandan, Murat; Pearson, Sean

    2012-10-09

    A demultiplexer circuit is disclosed which can be used with a conventional neural stimulator to extend the number of electrodes which can be activated. The demultiplexer circuit, which is formed on a semiconductor substrate containing a power supply that provides all the dc electrical power for operation of the circuit, includes digital latches that receive and store addressing information from the neural stimulator one bit at a time. This addressing information is used to program one or more 1:2.sup.N demultiplexers in the demultiplexer circuit which then route neural stimulation signals from the neural stimulator to an electrode array which is connected to the outputs of the 1:2.sup.N demultiplexer. The demultiplexer circuit allows the number of individual electrodes in the electrode array to be increased by a factor of 2.sup.N with N generally being in a range of 2-4.

  7. 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...

  8. Energetic particle influences in Earth's atmosphere

    Science.gov (United States)

    Aplin, Karen; Harrison, R. Giles; Nicoll, Keri; Rycroft, Michael; Briggs, Aaron

    2016-04-01

    Energetic particles from outer space, known as galactic cosmic rays, constantly ionise the entire atmosphere. During strong solar storms, solar energetic particles can also reach the troposphere and enhance ionisation. Atmospheric ionisation generates cluster ions. These facilitate current flow in the global electric circuit, which arises from charge separation in thunderstorms driven by meteorological processes. Energetic particles, whether solar or galactic in origin, may influence the troposphere and stratosphere through a range of different mechanisms, each probably contributing a small amount. Some of the suggested processes potentially acting over a wide spatial area in the troposphere include enhanced scavenging of charged aerosol particles, modification of droplet or droplet-droplet behavior by charging, and the direct absorption of infra-red radiation by the bending and stretching of hydrogen bonds inside atmospheric cluster-ions. As well as reviewing the proposed mechanisms by which energetic particles modulate atmospheric properties, we will also discuss new instrumentation for measurement of energetic particles in the atmosphere.

  9. Spectroscopic and electrical characters of SBD plasma excited by bipolar nanosecond pulse in atmospheric air

    Science.gov (United States)

    Zhao, Zi-Lu; Yang, De-Zheng; Wang, Wen-Chun; Yuan, Hao; Zhang, Li; Wang, Sen; Liu, Zhi-Jie; Zhang, Shuai

    2016-05-01

    In this paper, an atmospheric surface barrier discharge (SBD) generated by annular electrodes in quartz tube is presented through employing bipolar nanosecond pulse voltage in air. The discharge images, waveforms of pulse voltage and discharge current, and optical emission spectra emitted from the discharges are recorded and calculated. A spectra simulation method is developed to separate the overlap of the secondary diffraction spectra which are produced by grating in monochromator, and N2 (B3Πg → A3Σu+) and O (3p5P → 3s5S2o) are extracted. The effects of pulse voltage and discharge power on the emission intensities of OH (A2Σ+ → X2Пi), N2+ (B2Σu+ → X2Σg+), N2 (C3Πu → B3Πg), N2 (B3Πg → A3Σu+), and O (3p5P → 3s5S2o) are investigated. It is found that increasing the pulse peak voltage can lead to an easier formation of N2+ (B2Σu+) than that of N2 (C3Πu). Additionally, vibrational and rotational temperatures of the plasma are determined by comparing the experimental and simulated spectra of N2+ (B2Σu+ → X2Σg+), and the results show that the vibrational and rotational temperatures are 3250 ± 20 K and 350 ± 5 K under the pulse peak voltage of 28 kV, respectively.

  10. A Singularity in the Kirchhoff's Circuit Equations

    CERN Document Server

    Harsha, N R Sree

    2016-01-01

    Students often have difficulty in understanding qualitatively the behaviour of simple electric circuits. In particular, as different studies have shown, they find multiple batteries connected in multiple loops difficult to analyse. In a recent paper [Phys. Educ. 50 568 (2015)], we showed such an electric circuit, which consists of ideal batteries connected in parallel, that couldn't be solved by the existing circuit analysis methods. In this paper, we shall introduce a new mathematical method of solving simple electric circuits from the solutions of more general circuits and show that the currents, in this particular circuit, take the indeterminate 0/0 form. We shall also present some of the implications of teaching the method. We believe that the description presented in this paper should help the instructors in teaching the behaviour of multiple batteries connected in parallel.

  11. An atmospheric pressure plasma source driven by a train of monopolar high voltage pulses superimposed to a dc voltage

    OpenAIRE

    Stoican, O.S.

    2011-01-01

    Abstract An atmospheric pressure plasma source supplied by an electrical circuit consisting of two voltage sources in parallel connection is reported. One of them is a low-power self-oscillating flyback converter which produces negative voltage pulses with an amplitude of several kilovolts. The high voltage pulses are necessary to ignite an electrical discharge between the electrodes at atmospheric pressure. An additional dc source delivering several hundreds of volts at a few hund...

  12. 49 CFR 236.786 - Principle, closed circuit.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Principle, closed circuit. 236.786 Section 236.786 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Principle, closed circuit. The principle of circuit design where a normally energized electric circuit...

  13. 14 CFR 29.1357 - Circuit protective devices.

    Science.gov (United States)

    2010-01-01

    ... circuit protection. (g) Automatic reset circuit breakers may be used as integral protectors for electrical... the position of the operating control. (d) If the ability to reset a circuit breaker or replace a fuse is essential to safety in flight, that circuit breaker or fuse must be located and identified so...

  14. 30 CFR 57.12001 - Circuit overload protection.

    Science.gov (United States)

    2010-07-01

    ... Electricity Surface and Underground § 57.12001 Circuit overload protection. Circuits shall be protected against excessive overloads by fuses or circuit breakers of the correct type and capacity. ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit overload protection. 57.12001...

  15. 30 CFR 56.6605 - Isolation of blasting circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Isolation of blasting circuits. 56.6605 Section... Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead wires and blasting lines shall be... sources of stray or static electricity. Blasting circuits shall be protected from any contact...

  16. New energy management circuit applied in electric self-power supply over high voltage side%新型高压侧自供电电源设计与研究

    Institute of Scientific and Technical Information of China (English)

    李衍川; 江和

    2014-01-01

    分析了高压电场能量收集的原理,建立静电场耦合分布电容模型,并通过实验证明了模型的参考价值。随后,分析使用整流桥电路进行能量管理时的最佳功率点,并从增大超级电容充电电流的角度,设计了一种新型的管理电路,即同步电荷提取电路,以获得最佳的能量存储能力。结果证明存在一个最佳占空比使得收集的能量最大化,从而缩短无线节点在线监测工作周期。%The theory of energy harvested from the high voltage is analyzed, and then the corresponding model of coupling capacitance derived from static electric field is built, and several experiments are conducted to study whether the model is valuable. Then, according to what the result reveals, the optimal power point is found out when energy is managed by rectifier circuit. The value of charged current to super capacitor is used as the judge-ment whether the circuit system has the best storage performance. In that respect, management circuit is improved as a technology called Synchronous Electric Charge Extract, because the rectifier circuit can’ t perform as good as it is under ultrahigh voltage. It turns out that there is an optimal duty to maximize the energy harvested, so that the energy harvester can scavenge much more energy to cancellout the power loss. As a result, online monitoring period could be shortened greatly.

  17. Phase space representation of neutron monitor count rate and atmospheric electric field in relation to solar activity in cycles 21 and 22

    Science.gov (United States)

    Silva, H. G.; Lopes, I.

    2016-07-01

    Heliospheric modulation of galactic cosmic rays links solar cycle activity with neutron monitor count rate on earth. A less direct relation holds between neutron monitor count rate and atmospheric electric field because different atmospheric processes, including fluctuations in the ionosphere, are involved. Although a full quantitative model is still lacking, this link is supported by solid statistical evidence. Thus, a connection between the solar cycle activity and atmospheric electric field is expected. To gain a deeper insight into these relations, sunspot area (NOAA, USA), neutron monitor count rate (Climax, Colorado, USA), and atmospheric electric field (Lisbon, Portugal) are presented here in a phase space representation. The period considered covers two solar cycles (21, 22) and extends from 1978 to 1990. Two solar maxima were observed in this dataset, one in 1979 and another in 1989, as well as one solar minimum in 1986. Two main observations of the present study were: (1) similar short-term topological features of the phase space representations of the three variables, (2) a long-term phase space radius synchronization between the solar cycle activity, neutron monitor count rate, and potential gradient (confirmed by absolute correlation values above ~0.8). Finally, the methodology proposed here can be used for obtaining the relations between other atmospheric parameters (e.g., solar radiation) and solar cycle activity.

  18. Zirconium nitride films deposited in (Ar + N2 + H2) sputtering atmosphere: Optical, structural, and electrical properties

    International Nuclear Information System (INIS)

    Zr-N films were grown on glass substrates via radio-frequency magnetron sputtering using an Ar + N2 + H2 mixture. Hydrogen was employed in order to reduce oxygen contamination coming from background pressure, as confirmed by secondary ion mass spectroscopy analysis. The tuned process parameter was the nitrogen flux percentage (RN2) in the mixture. The crystallographic structure of the films was studied using x-ray diffraction. The measurements show that the films deposited at low RN2 (lower than or equal to 50%) crystallize in the rocksalt ZrN structure. As RN2 exceeds 50%, the film exhibits the co-presence of ZrN and Zr3N4 (denoted as o-Zr3N4) phases. When the deposition is performed in only nitrogen atmosphere (RN2 = 100%), a broad peak located at 2θ≅ 32.2 deg. is mainly attributed to the contribution coming from (320) planes of the o-Zr3N4. An envelope method, based on the optical reflection and transmission spectra taken at normal incidence, has been applied for the optical characterization of the nitride films. Such a method allows the determination of the samples' average thickness and optical constants (refractive index n and extinction coefficient k) in the ultraviolet-visible-near infrared regions. The evaluated thickness was about 2500 nm, which is in good agreement with the value obtained from profilometry. The absorption coefficient α was calculated from reflectance and transmittance spectra. The energy bandgap ranges from 2.3 eV to 2.4 eV. Electrical characterization was performed using capacitance-voltage measurements, which showed that the films evolve from insulating to semiconductor behavior when the nitrogen content in the sputtering atmosphere is decreased, confirming structural and optical results.

  19. Short-Circuit Withstand Current Rating for Low Voltage Switchgear : Short-Circuit Current Rating (SCCR)

    OpenAIRE

    Schütt, Matthias

    2016-01-01

    The subject of this thesis was to observe the short-circuit currents at electrical distribution boards. The purpose was to investigate different methods of protecting switchgears from dam-ages caused by short-circuit currents. Manufactures of switchgears need to indicate the rated short-circuit withstand current of their assembly. This thesis is presenting methods of defining the right value of the short-circuit withstand current. This thesis presents theoretical information about the cau...

  20. EDA circuit simulation

    International Nuclear Information System (INIS)

    EDA technique is used for circuit simulation. The circuit simulation and the analysis are made for a gate circuit one-shot multivibrator. The result shows: EDA circuit simulation is very useful technique

  1. 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)

  2. Balanced calibration of resonant shunt circuits for piezoelectric vibration control

    DEFF Research Database (Denmark)

    Høgsberg, Jan; Krenk, Steen

    2012-01-01

    Shunting of piezoelectric transducers and suitable electric circuits constitutes an effective passive approach to resonant vibration damping of structures. Most common design concepts for resonant resistor-inductor (RL) shunt circuits rely on either maximization of the attainable modal damping...

  3. Analog and VLSI circuits

    CERN Document Server

    Chen, Wai-Kai

    2009-01-01

    Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.

  4. Circuits courts

    OpenAIRE

    Dubuisson-Quellier, Sophie

    2015-01-01

    Si la notion de circuit court est aujourd’hui largement reprise par les médias comme un phénomène assez typique de la fin du 20ème siècle, il convient de considérer que la vente directe est aussi ancienne que l’agriculture elle-même. Au tournant des années 2000, elle est surtout devenu un moyen, pour ceux qui la promeuvent de souligner que les distances tant géographiques qu’organisationnelles entre ceux qui produisent et ceux qui consomment sont devenus trop longues et doivent être raccourci...

  5. LOGIC CIRCUIT

    Science.gov (United States)

    Strong, G.H.; Faught, M.L.

    1963-12-24

    A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)

  6. Approaching the Processes in the Generator Circuit Breaker at Disconnection through Sustainability Concepts

    OpenAIRE

    Carmen A. Bulucea; Nikos E. Mastorakis; Doru A. Nicola; Marc A. Rosen; Cornelia A. Bulucea

    2013-01-01

    Nowadays, the electric connection circuits of power plants (based on fossil fuels as well as renewable sources) entail generator circuit-breakers (GCBs) at the generator terminals, since the presence of that electric equipment offers many advantages related to the sustainability of a power plant. In an alternating current (a.c.) circuit the interruption of a short circuit is performed by the circuit-breaker at the natural passing through zero of the short-circuit current. During the current i...

  7. 《电路理论》课程"翻转课堂"的探索%The Exploration on the flipped classroom of electric circuit theory”curriculum

    Institute of Scientific and Technical Information of China (English)

    田莉; 李延平; 孙静; 张向华

    2015-01-01

    Flipped classroom is a new kind of teaching model. This paper presents the practice of applying this new model onto the curriculum teaching of"electric circuit theory". The teaching structure and the video processing of the flipped classroom on "electric circuit theory" are proposed. These results can provide some guidance on the practice of the flipped classroom and moti-vated the further exploration of the flipped classroom.%"翻转课堂"是一种新的教学模式。本文尝试在电路理论课堂采用"翻转课堂",提出了"翻转课堂"的教学结构以及"翻转课堂"所需的微视频的制备流程,为"翻转课堂"实施提供一定的指导,从而推动翻转课堂的进一步研究。

  8. Collective of mechatronics circuit

    International Nuclear Information System (INIS)

    This book is composed of three parts, which deals with mechatronics system about sensor, circuit and motor. The contents of the first part are photo sensor of collector for output, locating detection circuit with photo interrupts, photo sensor circuit with CdS cell and lamp, interface circuit with logic and LED and temperature sensor circuit. The second part deals with oscillation circuit with crystal, C-R oscillation circuit, F-V converter, timer circuit, stability power circuit, DC amp and DC-DC converter. The last part is comprised of bridge server circuit, deformation bridge server, controlling circuit of DC motor, controlling circuit with IC for PLL and driver circuit of stepping motor and driver circuit of Brushless.

  9. Measurements of the Atmospheric Electric Field through a Triangular Array and the Long-range Saharan Dust Electrification in Southern Portugal

    OpenAIRE

    Silva, H. G.; Lopes, F.; S. Pereira; Barbosa, S. M.; Nicoll, K.; Pereira, M. Collares; Harrison, R. G.

    2016-01-01

    Atmospheric electric field (AEF) measurements were carried out in three different sites forming a triangular array in Southern Portugal. The campaign was performed during the summer characterized by Saharan dust outbreaks; the 16th-17th July 2014 desert dust event is considered here. Evidence of long-range dust electrification is attributed to the air-Earth electrical current creating a positive space-charge inside of the dust layer. An increase of ~23 V/m is observed in AEF on the day of the...

  10. Electrical machines with Matlab

    CERN Document Server

    Gonen, Turan

    2011-01-01

    Basic ConceptsDistribution SystemImpact of Dispersed Storage and GenerationBrief Overview of Basic Electrical MachinesReal and Reactive Powers in Single-Phase AC CircuitsThree-Phase CircuitsThree-Phase SystemsUnbalanced Three-Phase LoadsMeasurement of Average Power in Three-Phase CircuitsPower Factor CorrectionMagnetic CircuitsMagnetic Field of Current-Carrying ConductorsAmpère's Magnetic Circuital LawMagnetic CircuitsMagnetic Circuit with Air GapBrief Review of FerromagnetismMagnetic Core LossesHow to Determine Flux for a Given MMFPermanent MagnetsTransformersTransformer ConstructionBrief Rev

  11. Understanding the Behaviour of Infinite Ladder Circuits

    Science.gov (United States)

    Ucak, C.; Yegin, K.

    2008-01-01

    Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does…

  12. Circuits in the Sun: Solar Panel Physics

    Science.gov (United States)

    Gfroerer, Tim

    2013-01-01

    Typical commercial solar panels consist of approximately 60 individual photovoltaic cells connected in series. Since the usual Kirchhoff rules apply, the current is uniform throughout the circuit, while the electric potential of the individual devices is cumulative. Hence, a solar panel is a good analog of a simple resistive series circuit, except…

  13. Electrical and electronic principles

    CERN Document Server

    Knight, S A

    1991-01-01

    Electrical and Electronic Principles, 2, Second Edition covers the syllabus requirements of BTEC Unit U86/329, including the principles of control systems and elements of data transmission. The book first tackles series and parallel circuits, electrical networks, and capacitors and capacitance. Discussions focus on flux density, electric force, permittivity, Kirchhoff's laws, superposition theorem, arrangement of resistors, internal resistance, and powers in a circuit. The text then takes a look at capacitors in circuit, magnetism and magnetization, electromagnetic induction, and alternating v

  14. Rotary Power Transformer and Inverter Circuit

    Science.gov (United States)

    Mclyman, C. W. T.; Bridgeforth, A. O.

    1985-01-01

    Noise lower than with sliprings. Rotary transformer transfers electric power across rotary joint. No wearing contacts, no contact noise, and no contamination from lubricants or wear debris. Because additional inductor not required, size and complexity of circuit reduced considerably.

  15. Quasi-Linear Circuit

    Science.gov (United States)

    Bradley, William; Bird, Ross; Eldred, Dennis; Zook, Jon; Knowles, Gareth

    2013-01-01

    This work involved developing spacequalifiable switch mode DC/DC power supplies that improve performance with fewer components, and result in elimination of digital components and reduction in magnetics. This design is for missions where systems may be operating under extreme conditions, especially at elevated temperature levels from 200 to 300 degC. Prior art for radiation-tolerant DC/DC converters has been accomplished utilizing classical magnetic-based switch mode converter topologies; however, this requires specific shielding and component de-rating to meet the high-reliability specifications. It requires complex measurement and feedback components, and will not enable automatic re-optimization for larger changes in voltage supply or electrical loading condition. The innovation is a switch mode DC/DC power supply that eliminates the need for processors and most magnetics. It can provide a well-regulated voltage supply with a gain of 1:100 step-up to 8:1 step down, tolerating an up to 30% fluctuation of the voltage supply parameters. The circuit incorporates a ceramic core transformer in a manner that enables it to provide a well-regulated voltage output without use of any processor components or magnetic transformers. The circuit adjusts its internal parameters to re-optimize its performance for changes in supply voltage, environmental conditions, or electrical loading at the output

  16. The role of cosmic rays in the Earth’s atmospheric processes

    Indian Academy of Sciences (India)

    Devendraa Siingh; R P Singh

    2010-01-01

    In this paper, we have provided an overview of cosmic ray effects on terrestrial processes such as electrical properties, global electric circuit, lightning, cloud formation, cloud coverage, atmospheric temperature, space weather phenomena, climate, etc. It is suggested that cosmic rays control short-term and long-term variations in climate. There are many basic phenomena which need further study and require new and long-term data set. Some of these have been pointed out.

  17. Symmetry properties in transmission lines loaded with electrically small resonators circuit modeling and application to common-mode suppressed differential lines, microwave sensors, and spectral signature barcodes

    OpenAIRE

    Naqui Garolera, Jordi

    2014-01-01

    Esta tesis se centra en el análisis, modelado circuital y aplicaciones de líneas de transmisión cargadas con resonadores eléctricamente pequeños (por ejemplo, resonadores de anillos abiertos -SRR- o resonadores de salto de impedancia -SIR-) sujetos a consideraciones de simetría. Los resultados obtenidos en esta tesis expanden el estado del arte en el marco de líneas de transmisión cargadas con resonadores i líneas de transmisión basadas en metamateriales. Por esta razón, primero revisamos la ...

  18. The electrical charging of inactive aerosols in high ionised atmosphere, the electrical charging of artificial beta radioactive aerosols; Le processus de charge electrique: des aerosols non radioactifs en milieu fortement ionise, des aerosols radioactifs artificiels emetteurs beta

    Energy Technology Data Exchange (ETDEWEB)

    Gensdarmes, F

    2000-07-01

    The electrical properties of aerosols greatly influence their transport and deposition in a containment. In a bipolar ionic atmosphere, a neutral electric charge on aerosols is commonly assumed. However, many studies report a different charge distribution in some situations, like highly ionised atmosphere or in the case of radioactive aerosols. Such situations could arise from a hypothetical accident in a nuclear power plant. Within the framework of safety studies which are carried out at IPSN, our aims were the study of electrical properties of aerosols in highly ionised atmosphere, and the study of artificial radioactive aerosols, in order to suggest experimental validation of available theories. For this purpose, we designed an experimental device that allows us to measure non-radioactive aerosol charge distribution under high gamma irradiation, up to 10{sup 4} Gy/h. With our experimental device we also studied the properties of small ions in the medium. Our results show a variation of the charge distribution in highly ionised atmosphere. The charge increases with the dose of gamma ray. We have related this variation with the one of the small ions in the gases, according to theoretical prediction. However, the model overestimates slightly our experimental results. In the case of the radioactive aerosols, we have designed an original experimental device, which allows us to study the charge distribution of a {sup 137}Cs aerosol. Our results show that the electric charging of such aerosols is strongly dependent on evolution parameters in a containment. So, our results underline a great enhancement of self-charging of particles which are sampled in a confined medium. Our results are qualitatively in agreement with the theoretical model; nevertheless the latter underestimates appreciably the self-charging, owing to the fact that wall effects are not taken into account. (author)

  19. Rocket borne instrument to measure electric fields inside electrified clouds

    Science.gov (United States)

    Ruhnke, L. H. (Inventor)

    1973-01-01

    An apparatus for measuring the electric field in the atmosphere which includes a pair of sensors carried on a rocket for sensing the voltages in the atmosphere being measured is described. One of the sensors is an elongated probe with a fine point which causes a corona current to be produced as it passes through the electric field. An electric circuit is coupled between the probe and the other sensor and includes a high ohm resistor which linearizes the relationship between the corona current and the electric field being measured. A relaxation oscillator and transmitter are provided for generating and transmitting an electric signal having a frequency corresponding to the magnitude of the electric field.

  20. Circuit breaker maintenance, sentinels on guard

    Energy Technology Data Exchange (ETDEWEB)

    Tanguay, F.

    2003-07-01

    Circuit breakers are essential components of every type and size of power system, and their maintenance is a matter of prime importance. This article provides a list of typical circuit breaker maintenance routines for each type of insulating medium and each type of breaker mechanism, and offers a number of useful tips to ensure the success of a circuit breaker maintenance program. It also suggests sources of information about maintenance programs for circuit breakers such as the National Electrical Testing Association's Maintenance Specifications, and companies that specialize in this type of service. 3 tabs.

  1. A robust predictive current controller for healthy and open-circuit faulty conditions of five-phase BLDC drives applicable for wind generators and electric vehicles

    International Nuclear Information System (INIS)

    Highlights: • Model predictive deadbeat control of generator stator phase currents. • Fault tolerant control of five-phase BLDC generator. • Control of stator phase currents under normal and open-circuit faulty conditions. • MATLAB simulation and experimental verification of proposed control method. • Verification of robustness and fast respond of proposed controlling method. - Abstract: Fault tolerant control of five-phase brushless direct current (BLDC) machines is gaining more importance in high-safety applications such as offshore wind generators and automotive industries. In many applications, traditional controllers (such as PI controllers) are used to control the stator currents under faulty conditions. These controllers have good performance with dc signals. However, in the case of missing one or two of the phases, appropriate reference currents of these machines have oscillatory dynamics both in phase- and synchronous-reference frames. Non-constant nature of these reference values requires the implication of fast current controllers. In this paper, model predictive deadbeat controllers are proposed to control the stator currents of five-phase BLDC machines under normal and faulty conditions. Open circuit fault is considered for both one and two stator phases, and the behaviour of proposed controlling method is evaluated. This evaluation is generally focused on first, sensitivity of proposed controlling method and second, its speed in following reference current values under transient states. Proposed method is simulated and is verified experimentally on a five-phase BLDC drive

  2. 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.

  3. Photomultiplier blanking circuit

    Science.gov (United States)

    Mcclenahan, J. O.

    1972-01-01

    Circuit for protecting photomultiplier equipment from current surges which occur when exposed to brilliant illumination is discussed. Components of circuit and details of operation are provided. Circuit diagram to show action of blanking pulse on zener diode is included.

  4. Analog circuit design designing waveform processing circuits

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The fourth volume in the set Designing Waveform-Processing Circuits builds on the previous 3 volumes and presents a variety of analog non-amplifier circuits, including voltage references, current sources, filters, hysteresis switches and oscilloscope trigger and sweep circuitry, function generation, absolute-value circuits, and peak detectors.

  5. Electric fields and conductivity in the nighttime E-region - A new magnetosphere-ionosphere-atmosphere coupling effect

    Science.gov (United States)

    Banks, P. M.; Yasuhara, F.

    1978-01-01

    Calculations have been made of the effects of intense poleward-directed electric fields upon the nighttime ionospheric E-region. The results show the Pedersen and Hall conductivities are substantially changed, thereby decreasing the ionospheric electrical load seen by magnetospheric sources. It appears that relatively large electric fields can exist in the absence of accompanying large field-aligned currents, as long as the underlying ionosphere remains in darkness and/or energetic particle precipitation is absent.

  6. 49 CFR 236.723 - Circuit, double wire; line.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, double wire; line. 236.723 Section 236.723 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.723 Circuit, double wire; line. An electric circuit not employing a common return wire; a...

  7. 49 CFR 236.732 - Controller, circuit; switch.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit; switch. 236.732 Section 236.732 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.732 Controller, circuit; switch. A device for opening and closing electric circuits, operated by...

  8. 14 CFR 25.1717 - Circuit protective devices: EWIS.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Circuit protective devices: EWIS. 25.1717... (EWIS) § 25.1717 Circuit protective devices: EWIS. Electrical wires and cables must be designed and installed so they are compatible with the circuit protection devices required by § 25.1357, so that a...

  9. Review and analysis for events of damage of electric circuits for safe shutdown in postulated fires at PWR power plants and countermeasures for preventing loss of inventory water caused by malfunction of valves

    International Nuclear Information System (INIS)

    The United States Nuclear Regulatory Commission (NRC) has been collecting reports on events concerning postulated fires from the viewpoint of fire protection for nuclear power plants. First of all, we reviewed these reports on the US nuclear power plants and analyzed (1) location of a fire, (2) part where the fire occurred and (3) the cause of the fire. The results revealed that the postulated fires had often occurred in areas dense with cables, such as central control rooms and cable connecting rooms, and the events caused by ground faults and short circuits resulting from cable fires had been predominant. Then, a comparison was made between PWRs in the United States and those in Japan in terms of the items and details of analysis on fire-caused damage of the electric circuits as described above. The comparison revealed that ''the event of loss of inventory water resulting from malfunction of valves caused by a fire'' was given consideration at the PWRs in the United States but not for those in Japan. Accordingly, countermeasures against this event were proposed. (author)

  10. Current induced annealing and electrical characterization of single layer graphene grown by chemical vapor deposition for future interconnects in VLSI circuits

    Science.gov (United States)

    Prasad, Neetu; Kumari, Anita; Bhatnagar, P. K.; Mathur, P. C.; Bhatia, C. S.

    2014-09-01

    Single layer graphene (SLG) grown by chemical vapor deposition (CVD) has been investigated for its prospective application as horizontal interconnects in very large scale integrated circuits. However, the major bottleneck for its successful application is its degraded electronic transport properties due to the resist residual trapped in the grain boundaries and on the surface of the polycrystalline CVD graphene during multi-step lithographic processes, leading to increase in its sheet resistance up to 5 MΩ/sq. To overcome this problem, current induced annealing has been employed, which helps to bring down the sheet resistance to 10 kΩ/sq (of the order of its initial value). Moreover, the maximum current density of ˜1.2 × 107 A/cm2 has been obtained for SLG (1 × 2.5 μm2) on SiO2/Si substrate, which is about an order higher than that of conventionally used copper interconnects.

  11. 大电流电动汽车电池充电电流电压反馈系统设计%High-current Electric Vehicle Battery Charging System’s Current and Voltage Sampling Circuit Design

    Institute of Scientific and Technical Information of China (English)

    章旦旸; 秦会斌

    2015-01-01

    针对电动汽车厂家研发了电动汽车电池充电系统,设计了一种大电流低电压电池充电系统。系统采用了PIC16F877A单片机作为电子控制单元核心,对规格为50 A、3.7 V的电池组进行充电。重点对电流电压采样电路进行了设计和研究。通过建立采样电路的仿真模型。并用实际电压电流数据对本采样系统进行了验证。实验证明,系统提出的电流电压采样具有较高的精度、线性度,且能满足长期稳定运行的实际需求。%For electric car manufacturers, an electric vehicle battery charging system is developed in the paper, which is a high-current low-voltage battery charging system. The system uses a PIC16F877A micro controller as the core of the electronic control unit to charge the 50 A, 3.7 V rechargeable battery packs. The paper focuses on the current and voltage sampling circuit design and research, as well as sampling circuit simulation. Actual voltage and current data of the sampling system is showed to verify the validity. Experiments show that both current and voltage sampling system can work with a good linearity and precision, and can also satisfy the need of long-term stable operation.

  12. Quantum Effects of Mesoscopic Inductance and Capacity Coupling Circuits

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Xin; AN Zhan-Yuan; SONG Yong-Hua

    2006-01-01

    Using the quantum theory for a mesoscopic circuit based on the discretenes of electric charges, the finitedifference Schrodinger equation of the non-dissipative mesoscopic inductance and capacity coupling circuit is achieved.The Coulomb blockade effect, which is caused by the discreteness of electric charges, is studied. Appropriately choose the components in the circuits, the finite-difference Schrodinger equation can be divided into two Mathieu equations in p representation. With the WKBJ method, the currents quantum fluctuations in the ground states of the two circuits are calculated. The results show that the currents quantum zero-point fluctuations of the two circuits are exist and correlated.

  13. Additive Manufacturing of Hybrid Circuits

    Science.gov (United States)

    Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David; Hirschfeld, Deidre; Hall, Aaron C.; Bell, Nelson S.

    2016-07-01

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects. Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. Finally, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.

  14. QUANTUM FLUCTUATIONS IN A MESOSCOPIC DAMPED LC PARALLEL CIRCUIT IN DISPLACED SQUEEZED FOCK STATE

    Institute of Scientific and Technical Information of China (English)

    GU YONG-JIAN

    2001-01-01

    We study the quantum effects of a damped LC parallel circuit considering its different performance from an RLC series circuit in classical physics. The damped LC parallel circuit with a source is quantized and the quantum fluctuations of magnetic flux and electric charge in the circuit in displaced squeezed Fock state are investigated. It is shown that, as in the RLC series circuit, the fluctuations only depend on the squeezing parameter and the parameters of the circuit components in the damped LC parallel circuit, but the effects of the circuit components on the fluctuations are different in the two circuits.

  15. Newnes circuit calculations pocket book with computer programs

    CERN Document Server

    Davies, Thomas J

    2013-01-01

    Newnes Circuit Calculations Pocket Book: With Computer Programs presents equations, examples, and problems in circuit calculations. The text includes 300 computer programs that help solve the problems presented. The book is comprised of 20 chapters that tackle different aspects of circuit calculation. The coverage of the text includes dc voltage, dc circuits, and network theorems. The book also covers oscillators, phasors, and transformers. The text will be useful to electrical engineers and other professionals whose work involves electronic circuitry.

  16. Basic electronic circuits

    CERN Document Server

    Buckley, P M

    1980-01-01

    In the past, the teaching of electricity and electronics has more often than not been carried out from a theoretical and often highly academic standpoint. Fundamentals and basic concepts have often been presented with no indication of their practical appli­ cations, and all too frequently they have been illustrated by artificially contrived laboratory experiments bearing little relationship to the outside world. The course comes in the form of fourteen fairly open-ended constructional experiments or projects. Each experiment has associated with it a construction exercise and an explanation. The basic idea behind this dual presentation is that the student can embark on each circuit following only the briefest possible instructions and that an open-ended approach is thereby not prejudiced by an initial lengthy encounter with the theory behind the project; this being a sure way to dampen enthusiasm at the outset. As the investigation progresses, questions inevitably arise. Descriptions of the phenomena encounte...

  17. A dishwasher for circuits

    CERN Multimedia

    Rosaria Marraffino

    2014-01-01

    You have always been told that electronic devices fear water. However, at the Surface Mount Devices (SMD) Workshop here at CERN all the electronic assemblies are cleaned with a machine that looks like a… dishwasher.   The circuit dishwasher. Credit: Clara Nellist.  If you think the image above shows a dishwasher, you wouldn’t be completely wrong. Apart from the fact that the whole pumping system and the case itself are made entirely from stainless steel and chemical resistant materials, and the fact that it washes electrical boards instead of dishes… it works exactly like a dishwasher. It’s a professional machine (mainly used in the pharmaceutical industry) designed to clean everything that can be washed with a water-based chemical soap. This type of treatment increases the lifetime of the electronic boards and therefore the LHC's reliability by preventing corrosion problems in the severe radiation and ozone environment of the LHC tunn...

  18. Solid-state circuits

    CERN Document Server

    Pridham, G J

    2013-01-01

    Solid-State Circuits provides an introduction to the theory and practice underlying solid-state circuits, laying particular emphasis on field effect transistors and integrated circuits. Topics range from construction and characteristics of semiconductor devices to rectification and power supplies, low-frequency amplifiers, sine- and square-wave oscillators, and high-frequency effects and circuits. Black-box equivalent circuits of bipolar transistors, physical equivalent circuits of bipolar transistors, and equivalent circuits of field effect transistors are also covered. This volume is divided

  19. Current induced annealing and electrical characterization of single layer graphene grown by chemical vapor deposition for future interconnects in VLSI circuits

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Neetu, E-mail: neetu.prasad@south.du.ac.in, E-mail: neetu23686@gmail.com; Kumari, Anita; Bhatnagar, P. K.; Mathur, P. C. [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021 (India); Bhatia, C. S. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

    2014-09-15

    Single layer graphene (SLG) grown by chemical vapor deposition (CVD) has been investigated for its prospective application as horizontal interconnects in very large scale integrated circuits. However, the major bottleneck for its successful application is its degraded electronic transport properties due to the resist residual trapped in the grain boundaries and on the surface of the polycrystalline CVD graphene during multi-step lithographic processes, leading to increase in its sheet resistance up to 5 MΩ/sq. To overcome this problem, current induced annealing has been employed, which helps to bring down the sheet resistance to 10 kΩ/sq (of the order of its initial value). Moreover, the maximum current density of ∼1.2 × 10{sup 7 }A/cm{sup 2} has been obtained for SLG (1 × 2.5 μm{sup 2}) on SiO{sub 2}/Si substrate, which is about an order higher than that of conventionally used copper interconnects.

  20. Current induced annealing and electrical characterization of single layer graphene grown by chemical vapor deposition for future interconnects in VLSI circuits

    International Nuclear Information System (INIS)

    Single layer graphene (SLG) grown by chemical vapor deposition (CVD) has been investigated for its prospective application as horizontal interconnects in very large scale integrated circuits. However, the major bottleneck for its successful application is its degraded electronic transport properties due to the resist residual trapped in the grain boundaries and on the surface of the polycrystalline CVD graphene during multi-step lithographic processes, leading to increase in its sheet resistance up to 5 MΩ/sq. To overcome this problem, current induced annealing has been employed, which helps to bring down the sheet resistance to 10 kΩ/sq (of the order of its initial value). Moreover, the maximum current density of ∼1.2 × 107 A/cm2 has been obtained for SLG (1 × 2.5 μm2) on SiO2/Si substrate, which is about an order higher than that of conventionally used copper interconnects.