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. The atmospheric electric global circuit. [thunderstorm activity

    Science.gov (United States)

    Kasemir, H. W.

    1979-01-01

    The hypothesis that world thunderstorm activity represents the generator for the atmospheric electric current flow in the earth atmosphere between ground and the ionosphere is based on a close correlation between the magnitude and the diurnal variation of the supply current (thunderstorm generator current) and the load current (fair weather air-earth current density integrated over the earth surface). The advantages of using lightning survey satellites to furnish a base for accepting or rejecting the thunderstorm generator hypothesis are discussed.

  3. Comment on 'Current Budget of the Atmospheric Electric Global Circuit'

    Science.gov (United States)

    Driscoll, Kevin T.; Blakeslee, Richard J.

    1996-01-01

    In this paper, three major issues relevant to Kasemir's new model will be addressed. The first concerns Kasemir's assertion that there are significant differences between the potentials associated with the new model and the conventional model. A recalculation of these potentials reveals that both models provide equivalent results for the potential difference between the Earth and ionosphere. The second issue to be addressed is Kasemir's assertion that discrepancies in the electric potentials associated with both models can be attributed to modeling the Earth as a sphere, instead of as a planar surface. A simple analytical comparison will demonstrate that differences in the equations for the potentials of the atmosphere derived with a spherical and a planar Earth are negligible for applications to global current flow. Finally, the third issue to be discussed is Kasemir's claim that numerous aspects of the conventional model are incorrect, including the role of the ionosphere in global current flow as well as the significance of cloud-to-ground lightning in supplying charge to the global circuit. In order to refute these misconceptions, it will be shown that these aspects related to the flow of charge in the atmosphere are accurately described by the conventional model of the global circuit.

  4. Early twentieth century response of the global atmospheric electric circuit to ENSO

    Science.gov (United States)

    Harrison, G.; Joshi, M.

    2012-04-01

    The global atmospheric electric circuit links charge separation in disturbed weather regions with current flow in the fair weather regions elsewhere. Variations in disturbed weather, such as the changes in lightning associated with Pacific ocean temperature anomalies, can be expected in turn to modify currents flowing in the global atmospheric electric circuit. Strengthening and weakening of the global circuit current has been observed* to follow El Niño and La Niña respectively, from northern hemisphere atmospheric electricity data obtained during the 1970s. Extending this relationship quantitatively into the first half of the twentieth century is pursued here, using surface data from multiple atmospheric electricity observatories including measurements from the southern hemisphere. The independent atmospheric electricity time series from the observatories show similar variations, which is a pre-requisite for inferring global circuit variations from surface measurement. Combining the measurements allows the global circuit sensitivity to ENSO sea surface temperature anomalies to be derived during the earlier part of the twentieth century. * R.G. Harrison, M. Joshi, K. Pascoe, Inferring convective responses to El Niño with atmospheric electricity measurements at Shetland Environ Res Lett 6 (2011) 044028 http://iopscience.iop.org/1748-9326/6/4/044028/

  5. 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.

  6. Brief communication: Earthquake–cloud coupling through the global atmospheric electric circuit

    Directory of Open Access Journals (Sweden)

    R. G. Harrison

    2013-12-01

    Full Text Available We illustrate how coupling could occur between surface air and clouds via the global electric circuit – through Atmospheric Lithosphere–Ionosphere Charge Exchange (ALICE processes – in an attempt to develop physical understanding of possible relationships between earthquakes and clouds.

  7. 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

  8. 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

  9. 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

  10. 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)

  11. Accumulation boundaries: codimension-two accumulation of accumulations in phase diagrams of semiconductor lasers, electric circuits, atmospheric and chemical oscillators.

    Science.gov (United States)

    Bonatto, Cristian; Gallas, Jason Alfredo Carlson

    2008-02-28

    We report high-resolution phase diagrams for several familiar dynamical systems described by sets of ordinary differential equations: semiconductor lasers; electric circuits; Lorenz-84 low-order atmospheric circulation model; and Rössler and chemical oscillators. All these systems contain chaotic phases with highly complicated and interesting accumulation boundaries, curves where networks of stable islands of regular oscillations with ever-increasing periodicities accumulate systematically. The experimental exploration of such codimension-two boundaries characterized by the presence of infinite accumulation of accumulations is feasible with existing technology for some of these systems.

  12. The Changing Global Atmospheric Electric Circuit as a Way of Causing Space Weather Effects on Middle Atmosphere Electrodynamic and Thermodynamic Parameters

    Science.gov (United States)

    Makarova, L.; Shirochkov, A.

    So far the solar wind energy contribution to energetic balance of the middle atmosphere was ignored in any climatic research. However the solar wind is a permanent source of electromagnetic energy constantly supplied to the near-Earth space and its role is evaluated properly in magnetospheric and ionospheric (to lesser extent) studies. We made extensive studies of the direct solar wind influence on the thermodynamic features of the middle atmosphere by analyzing data of the rocket and balloon sounding. Data of many stations covering latitudinal belt 80o N-55o N and 90o S-65o S- were used. It was found that the stratospheric temperature closely correlated with the solar wind energy expressed as the subsolar distance between the Earth and magnetopause. The best coupling between these two parameters (r>0,8) was obtained for altitudes 22-26 km with decreasing (but meaningful) coupling up and dawn from these heights. Similar dependence between this space parameter and ozone density in its stratospheric maximum was obtained also. As a very important factor a strong (r=0,78) coupling between magnetopause position and magnitude of atmospheric electric field measured by high-altitude balloons above South P leo Station must be mentioned. All these findings allowed us to propose concept of the global electric circuit as a physical mechanism for explanation of a direct coupling between the solar wind and the middle atmosphere. We suggest a new, modified version of the circuit where an external Electro-motive Force generator driven by the solar wind energy is located at dayside magnetopause. The passive elements of this circuit are the ionospheric Elayer (external element of previous version of the- circuit), stratospheric conducting layer of heavy ions (h=20-25 km) and conducting layer of the Earth surface. In this configuration a previous scheme of the global electric circuit is a part of the proposed version of it. The changes of stratospheric temperature could be explained

  13. 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

  14. A 3-D RBF-FD elliptic solver for irregular boundaries: modeling the atmospheric global electric circuit with topography

    Directory of Open Access Journals (Sweden)

    V. Bayona

    2015-04-01

    Full Text Available A numerical model based on Radial Basis Function-generated Finite Differences (RBF-FD is developed for simulating the Global Electric Circuit (GEC within the Earth's atmosphere, represented by a 3-D variable coefficient linear elliptic PDE in a spherically-shaped volume with the lower boundary being the Earth's topography and the upper boundary a sphere at 60 km. To our knowledge, this is (1 the first numerical model of the GEC to combine the Earth's topography with directly approximating the differential operators in 3-D space, and related to this (2 the first RBF-FD method to use irregular 3-D stencils for discretization to handle the topography. It benefits from the mesh-free nature of RBF-FD, which is especially suitable for modeling high-dimensional problems with irregular boundaries. The RBF-FD elliptic solver proposed here makes no limiting assumptions on the spatial variability of the coefficients in the PDE (i.e. the conductivity profile, the right hand side forcing term of the PDE (i.e. distribution of current sources or the geometry of the lower boundary.

  15. A Global Electric Circuit on Mars

    Science.gov (United States)

    Delory, G. T.; Farrell, W. M.; Desch, M. D.

    2001-01-01

    We describe conditions on the surface of Mars conducive to the formation of a martian global electric circuit, in a direct analogy to the terrestrial case where atmospheric currents and electric fields are generated worldwide through the charging in thunderstorms. Additional information is contained in the original extended abstract.

  16. 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

  17. 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 di...... that conduction and convection currents associated with "batteries" within thunderclouds and electrified shower clouds contribute essentially equally (similar to 500 A each) to maintaining the ionospheric potential....

  18. Variational integrators for electric circuits

    Energy Technology Data Exchange (ETDEWEB)

    Ober-Blöbaum, Sina, E-mail: sinaob@math.upb.de [Computational Dynamics and Optimal Control, University of Paderborn (Germany); Tao, Molei [Courant Institute of Mathematical Sciences, New York University (United States); Cheng, Mulin [Applied and Computational Mathematics, California Institute of Technology (United States); Owhadi, Houman; Marsden, Jerrold E. [Control and Dynamical Systems, California Institute of Technology (United States); Applied and Computational Mathematics, California Institute of Technology (United States)

    2013-06-01

    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.

  19. 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...

  20. 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...

  1. Fractional linear systems and electrical circuits

    CERN Document Server

    Kaczorek, Tadeusz

    2015-01-01

    This monograph covers some selected problems of positive and fractional electrical circuits composed of resistors, coils, capacitors and voltage (current) sources. The book consists of 8 chapters, 4 appendices and a list of references. Chapter 1 is devoted to fractional standard and positive continuous-time and discrete-time linear systems without and with delays. In chapter 2 the standard and positive fractional electrical circuits are considered and the fractional electrical circuits in transient states are analyzed.  Descriptor linear electrical circuits and their properties are investigated in chapter 3,  while chapter 4 is devoted to the stability of fractional standard and positive linear electrical circuits. The reachability, observability and reconstructability of fractional positive electrical circuits and their decoupling zeros are analyzed in chapter 5. The fractional linear electrical circuits with feedbacks are considered in chapter 6. In chapter 7 solutions of minimum energy control for standa...

  2. Quantum Electric Circuits Analogous to Ballistic Conductors

    OpenAIRE

    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...

  3. MESOSCOPIC ELECTRIC CIRCUITS WITH CHARGE DISCRETIZATION

    OpenAIRE

    2004-01-01

    MESOSCOPIC ELECTRIC CIRCUITS WITH CHARGE DISCRETIZATION Nanoscience is a modern aspect of electronic engineering with significant projections for applications on new devices. This project allowed presenting an innovative language and a rigorous vision on aspects of nanoscience. The theory of quantum electrical circuits with discrete charge corresponds to the description (in simple terms) of some aspects of nanoscience. Our results gather aspects of quantum mechanics, electrical circuit...

  4. Electric Circuit Theory--Computer Illustrated Text.

    Science.gov (United States)

    Riches, Brian

    1990-01-01

    Discusses the use of a computer-illustrated text (CIT) with integrated software to teach electric circuit theory to college students. Examples of software use are given, including simple animation, graphical displays, and problem-solving programs. Issues affecting electric circuit theory instruction are also addressed, including mathematical…

  5. Entropy production by simple electrical circuits

    CERN Document Server

    Miranda, E N

    2012-01-01

    The entropy production by simple electrical circuits (R, RC, RL) is analyzed. It comes out that the entropy production is minimal, in agreement with a well known theorem due to Prigogine. In this way, it is wrong a recent result by Zupanovic, Juretic and Botric (Physica Review E 70, 056198) who claimed that the entropy production in simple electrical circuits is a maximum

  6. 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.

  7. 29 CFR 1915.181 - Electrical circuits and distribution boards.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Electrical circuits and distribution boards. 1915.181... Electrical Machinery § 1915.181 Electrical circuits and distribution boards. (a) The provisions of this... employee is permitted to work on an electrical circuit, except when the circuit must remain energized...

  8. 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.

  9. Biologically closed electrical circuits in venus flytrap.

    Science.gov (United States)

    Volkov, Alexander G; Carrell, Holly; Markin, Vladislav S

    2009-04-01

    The Venus flytrap (Dionaea muscipula Ellis) is a marvel of plant electrical, mechanical, and biochemical engineering. The rapid closure of the Venus flytrap upper leaf in about 0.1 s is one of the fastest movements in the plant kingdom. We found earlier that the electrical stimulus between a midrib and a lobe closes the Venus flytrap upper leaf without mechanical stimulation of trigger hairs. The Venus flytrap can accumulate small subthreshold charges and, when the threshold value is reached, the trap closes. Here, we investigated the electrical properties of the upper leaf of the Venus flytrap and proposed the equivalent electrical circuit in agreement with the experimental data.

  10. Lord Kelvin's atmospheric electricity measuremnets

    CERN Document Server

    Aplin, K L

    2013-01-01

    Lord Kelvin (William Thomson) made important contributions to the study of atmospheric electricity during a brief but productive period from 1859-1861. By 1859 Kelvin had recognised the need for "incessant recording" of atmospheric electrical parameters, and responded by inventing both the water-dropper instrument for measuring the atmospheric Potential Gradient (PG), and photographic data logging. The water-dropper was widely adopted internationally and is still in use today. Following theoretical considerations of electric field distortion by local topography, Kelvin developed a portable electrometer, using it to investigate PG on the Scottish island of Arran. During these environmental measurements, Kelvin may have unwittingly detected atmospheric PG changes during solar activity in August/September 1859 associated with the "Carrington event". Kelvin's atmospheric electricity work presents an early representative study in quantitative environmental physics, through the application of mathematical principle...

  11. 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.

  12. 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.

  13. 30 CFR 75.509 - Electric power circuit and electric equipment; deenergization.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric power circuit and electric equipment...-General § 75.509 Electric power circuit and electric equipment; deenergization. All power circuits and electric equipment shall be deenergized before work is done on such circuits and equipment, except...

  14. 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....

  15. 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...

  16. 30 CFR 56.4011 - Abandoned electric circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Abandoned electric circuits. 56.4011 Section 56.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Control § 56.4011 Abandoned electric circuits. Abandoned electric circuits shall be deenergized...

  17. 30 CFR 57.4011 - Abandoned electric circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Abandoned electric circuits. 57.4011 Section 57.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Control § 57.4011 Abandoned electric circuits. Abandoned electric circuits shall be...

  18. Atmospheric Electricity - Aircraft Interaction

    Science.gov (United States)

    1980-05-01

    magnetic field will be about 40 Tesla producing a magnetic pressure approaching 6.3 x 108 N/M2 (150,000 lbs/in. 2 ). Externally mounted electrical...Heater - 2 Flight Director Computer 1 - Navigation Light - I AC Generator Tripoff (6 Instances of Triopoff) Autopilot 1- Engine Mishaps Reported lightning

  19. 30 CFR 77.500 - Electric power circuits and electric equipment; deenergization.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric power circuits and electric equipment... OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.500 Electric power circuits and electric equipment; deenergization. Power circuits and electric equipment shall be deenergized before work is done...

  20. Fuel Cell Equivalent Electric Circuit Parameter Mapping

    DEFF Research Database (Denmark)

    Jeppesen, Christian; Zhou, Fan; Andreasen, Søren Juhl

    In this work a simple model for a fuel cell is investigated for diagnostic purpose. The fuel cell is characterized, with respect to the electrical impedance of the fuel cell at non-faulty conditions and under variations in load current. Based on this the equivalent electrical circuit parameters can...... be estimation as a function of the load current. The data is based on an experiment conducted using a single BASF prototype Celtec P2100 HTPEM fuel cell (45 cm2 ) operated at 160 C, installed in a Greenlight fuel cell test station....

  1. Fractional RC and LC Electrical Circuits

    Directory of Open Access Journals (Sweden)

    Gómez-Aguilar José Francisco

    2014-04-01

    Full Text Available In this paper we propose a fractional differential equation for the electrical RC and LC circuit in terms of the fractional time derivatives of the Caputo type. The order of the derivative being considered is 0 < ɣ ≤1. To keep the dimensionality of the physical parameters R, L, C the new parameter σ is introduced. This parameter characterizes the existence of fractional structures in the system. A relation between the fractional order time derivative ɣ and the new parameter σ is found. The numeric Laplace transform method was used for the simulation of the equations results. The results show that the fractional differential equations generalize the behavior of the charge, voltage and current depending of the values of ɣ. The classical cases are recovered by taking the limit when ɣ = 1. An analysis in the frequency domain of an RC circuit shows the application and use of fractional order differential equations.

  2. How Young Children Understand Electric Circuits: Prediction, Explanation and Exploration

    Science.gov (United States)

    Glauert, Esme Bridget

    2009-01-01

    This paper reports findings from a study of young children's views about electric circuits. Twenty-eight children aged 5 and 6 years were interviewed. They were shown examples of circuits and asked to predict whether they would work and explain why. They were then invited to try out some of the circuit examples or make circuits of their own…

  3. Solar wind influences on atmospheric electricity variables in polar regions

    Science.gov (United States)

    Michnowski, Stanisław

    The measurement techniques applied in magnetospheric and ionospheric research enable detection of strong, intrinsic effects of solar wind on ionospheric electrical potential distribution and conductivity of the atmosphere. These manifestations of the solar wind interaction with the magnetosphere and ionosphere are especially evident at high latitudes. The possibility of observing there the response of the atmospheric electricity variables to solar wind has been questioned for a long time despite the fact that the atmospheric electric field and current variations at the ground are physically linked with electric potential of the ionosphere and conductivity of the lower atmosphere. The serious doubts were mainly due to the generally accepted opinion that the highly conducting ionosphere is an almost ideal equipotential electric screen that separates the weakly conductive lower atmosphere of the influence from space. This assumption could not be further upheld in view of the new findings. They have been provided for some time by ground-based atmospheric electric field and current measurements (AEMs) with simultaneous upper atmosphere observations and by corresponding balloon measurements. Recent ground-based AEMs in polar regions, i.e., in the near-subauroral, auroral, and polar cap high-latitude regions, have detected considerable influence of solar wind on the lower-atmosphere electric variables. However, the use of atmospheric electric observations in studying solar-terrestrial relations is still limited. The main reason is difficulty in separating various local meteorological effects, anthropogenic effects, and the effects of the global electric current circuit which affect simultaneously the measured quantities. Transmission of the electric signals through the lower atmosphere can also introduce troublesome disturbances. The paper outlines these problems and hints how the difficulties involved might be partly overcome in a feasible way. The needs and possible

  4. Performance analysis of electrical circuits /PANE/

    Science.gov (United States)

    Johnson, K. L.; Steinberg, L. L.

    1968-01-01

    Automated statistical and worst case computer program has been designed to perform dc and ac steady circuit analyses. The program determines the worst case circuit performance by solving circuit equations.

  5. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  6. 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…

  7. 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.

  8. Secondary School Students' Misconceptions about Simple Electric Circuits

    Science.gov (United States)

    Küçüközer, Hüseyin; Kocakülah, Sabri

    2007-01-01

    The aim of this study is to reveal secondary school students' misconceptions about simple electric circuits and to define whether specific misconceptions peculiar to Turkish students exist within those identified. Data were obtained with a conceptual understanding test for simple electric circuits and semi-structured interviews. Conceptual…

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

    Science.gov (United States)

    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 circuits were measured. The MEGS-based electrical circuit possesses the best electrical conductivity, and the GOS-based electrical circuit has the poorest electrical conductivity among all three circuits. The three types of electrical circuits were applied for the detection of copper ions (Cu(2+)). The RGOS-based electrical circuit can detect the Cu(2+) when the concentration of Cu(2+) was as low as 10 nM in solution. The GOS-based electrical circuit can only detect Cu(2+) after chemical reduction. The possible mechanism of electron transfer was proposed for the detection. The facile fabrication method and excellent performance imply the RGOS-based electrical circuit has great potential to be applied to metal ion sensors.

  10. Electric circuit model for strained-layer epitaxy

    Science.gov (United States)

    Kujofsa, Tedi; Ayers, John E.

    2016-11-01

    For the design and analysis of a strained-layer semiconductor device structure, the equilibrium strain profile may be determined numerically by energy minimization but this method is computationally intense and non-intuitive. Here we present an electric circuit model approach for the equilibrium analysis of an epitaxial stack, in which each sublayer may be represented by an analogous configuration involving a current source, a resistor, a voltage source, and an ideal diode. The resulting node voltages in the analogous electric circuit correspond to the equilibrium strains in the original epitaxial structure. This new approach enables analysis using widely accessible circuit simulators, and an intuitive understanding of electric circuits may be translated to the relaxation of strained-layer structures. In this paper, we describe the mathematical foundation of the electrical circuit model and demonstrate its application to epitaxial layers of Si1-x Ge x grown on a Si (001) substrate.

  11. A figure of merit for neural electrical stimulation circuits.

    Science.gov (United States)

    Kolbl, Florian; Demosthenous, Andreas

    2015-01-01

    Electrical stimulators are widely used in neuro-prostheses. Many different implementations exist. However, no quantitative ranking criterion is available to allow meaningful comparison of the various stimulation circuits and systems to aid the designer. This paper presents a novel Figure of Merit (FOM) dedicated to stimulation circuits and systems. The proposed optimization performance metric takes into account tissue safety conditions and energy efficiency which can be evaluated by measurement. The FOM is used to rank several stimulator circuits and systems.

  12. Note on homological modeling of the electric circuits

    OpenAIRE

    2014-01-01

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

  13. Hamilton´s Principle and Electric Circuits Tudory

    OpenAIRE

    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.

  14. Shuttle Electrical Power Analysis Program (SEPAP) distribution circuit analysis report

    Science.gov (United States)

    Torina, E. M.

    1975-01-01

    An analysis and evaluation was made of the operating parameters of the shuttle electrical power distribution circuit under load conditions encountered during a normal Sortie 2 Mission with emphasis on main periods of liftoff and landing.

  15. 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.

  16. Enhancing student learning and conceptual understanding of electric circuits

    OpenAIRE

    2010-01-01

    Prior research has highlighted that students have many conceptual difficulties regarding electric circuits and that traditional teaching methods are not successful in overcoming these difficulties. In addressing this issue, this research project placed its primary focus on the development of research based and research validated curriculum which systematically promotes the development of a scientific model for electric circuits. Over the last four years, the project focussed on deve...

  17. 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.

  18. Preschool children learn about electric circuit

    OpenAIRE

    Jarc, Nina

    2015-01-01

    In the theoretical part of my thesis, I first summarized what can be found in literature concerning electricity treatment (Labinowicz, Driver) and particularities of topics treatment in a preschool period, as well. I presented the concepts of electricity and electrical current, respectively, and several simple devices that operate on the basis of electricity, sources and the concept of electric energy. In the empirical part I first presented the questionnaire for identification of childr...

  19. Power and heat fluctuation theorems for electric circuits.

    Science.gov (United States)

    van Zon, R; Ciliberto, S; Cohen, E G D

    2004-04-02

    Using recent fluctuation theorems from nonequilibrium statistical mechanics, we extend the theory for voltage fluctuations in electric circuits to power and heat fluctuations. They could be of particular relevance for the functioning of small circuits. This is done for a parallel resistor and capacitor with a constant current source for which we use the analogy with a Brownian particle dragged through a fluid by a moving harmonic potential, where circuit-specific analogs are needed on top of the Brownian-Nyquist analogy. The results may also hold for other circuits as another example shows.

  20. Energy pumping in electrical circuits under avalanche noise.

    Science.gov (United States)

    Kanazawa, Kiyoshi; Sagawa, Takahiro; Hayakawa, Hisao

    2014-07-01

    We theoretically study energy pumping processes in an electrical circuit with avalanche diodes, where non-Gaussian athermal noise plays a crucial role. We show that a positive amount of energy (work) can be extracted by an external manipulation of the circuit in a cyclic way, even when the system is spatially symmetric. We discuss the properties of the energy pumping process for both quasistatic and finite-time cases, and analytically obtain formulas for the amounts of the work and the power. Our results demonstrate the significance of the non-Gaussianity in energetics of electrical circuits.

  1. 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.

  2. 30 CFR 75.518-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 75.518-1 Section 75.518-1 Mineral Resources MINE SAFETY...-UNDERGROUND COAL MINES Electrical Equipment-General § 75.518-1 Electric equipment and circuits; overload...

  3. Quantized amplitudes in a nonlinear resonant electrical circuit

    CERN Document Server

    Cretin, B

    2008-01-01

    We present a simple nonlinear resonant analog circuit which demonstrates quantization of resonating amplitudes, for a given excitation level. The system is a simple RLC resonator where C is an active capacitor whose value is related to the current in the circuit. This variation is energetically equivalent to a variation of the potential energy and the circuit acts as a pendulum in the gravitational field. The excitation voltage, synchronously switched at the current frequency, enables electrical supply and keeping the oscillation of the system. The excitation frequency has been set to high harmonic of the fundamental oscillation so that anisochronicity can keep constant the amplitude of the circuit voltage and current. The behavior of the circuit is unusual: different stable amplitudes have been measured depending on initial conditions and excitation frequency, for the same amplitude of the excitation. The excitation frequency is naturally divided by the circuit and the ratio is kept constant without external...

  4. Stochastic Resonance Induced by Dichotomous Resistor in an Electric Circuit

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Hui; HAN Yin-Xia

    2007-01-01

    An electric circuit with dichotomous resistor is investigated.It is shown that the amplitude of the average electric current washing the resistor represents the phenomenon of stochastic resonance,which is the response as a function of the correlation time of the dichotomous resistor.

  5. An Unsolved Electric Circuit: A Common Misconception

    Science.gov (United States)

    Harsha, N. R. Sree; Sreedevi, A.; Prakash, Anupama

    2015-01-01

    Despite a number of theories in circuit analysis, little is known about the behaviour of ideal equal voltage sources in parallel, connected across a resistive load. We neither have any theory that can predict the voltage source that provides the load current, nor is there any method to test it experimentally. In a series of experiments performed…

  6. 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...

  7. Integrated circuit electrometer and sweep circuitry for an atmospheric probe

    Science.gov (United States)

    Zimmerman, L. E.

    1971-01-01

    The design of electrometer circuitry using an integrated circuit operational amplifier with a MOSFET input is described. Input protection against static voltages is provided by a dual ultra low leakage diode or a neon lamp. Factors affecting frequency response leakage resistance, and current stability are discussed, and methods are suggested for increasing response speed and for eliminating leakage resistance and current instabilities. Based on the above, two practical circuits, one having a linear response and the other a logarithmic response, were designed and evaluated experimentally. The design of a sweep circuit to implement mobility measurements using atmospheric probes is presented. A triangular voltage waveform is generated and shaped to contain a step in voltage from zero volts in both positive and negative directions.

  8. 49 CFR 236.308 - Mechanical or electric locking or electric circuits; requisites.

    Science.gov (United States)

    2010-10-01

    ...; requisites. Mechanical or electric locking or electric circuits shall be installed to prevent signals from... 49 Transportation 4 2010-10-01 2010-10-01 false Mechanical or electric locking or electric... GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS,...

  9. Circadian rhythms in electrical circuits of Clivia miniata.

    Science.gov (United States)

    Volkov, Alexander G; Wooten, Joseph D; Waite, Astian J; Brown, Corydon R; Markin, Vladislav S

    2011-10-15

    The biological clock regulates a wide range of physiological processes in plants. Here we show circadian variation of the Clivia miniata responses to electrical stimulation. The biologically closed electrochemical circuits in the leaves of C. miniata (Kaffir lily), which regulate its physiology, were analyzed in vivo using the charge stimulation method. The electrostimulation was provided with different voltages and electrical charges. Resistance between Ag/AgCl electrodes in the leaf of C. miniata was higher at night than during the day or the following day in the darkness. The biologically closed electrical circuits with voltage gated ion channels in C. miniata are activated the next day, even in the darkness. C. miniata memorizes daytime and nighttime. At continuous light, C. miniata recognizes nighttime and increases the input resistance to the nighttime value even under light. These results show that the circadian clock can be maintained endogenously and has electrochemical oscillators, which can activate voltage gated ion channels in biologically closed electrochemical circuits. The activation of voltage gated channels depends on the applied voltage, electrical charge and speed of transmission of electrical energy from the electrostimulator to the C. miniata leaves. We present the equivalent electrical circuits in C. miniata and its circadian variation to explain the experimental data.

  10. 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 CDR...... circuits at the receiver interface, though VCOs are also found in the transmitter where a multitude of independent sources have to be mutually synchronized before multiplexing. The circuits are based on an InP DHBT process (VIP-2) supplied by Vitesse and made publicly available as MPW. The VIP-2 process...

  11. 30 CFR 77.501 - Electric distribution circuits and equipment; repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric distribution circuits and equipment... OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.501 Electric distribution circuits and equipment; repair. No electrical work shall be performed on electric distribution circuits or...

  12. 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.

  13. Estimating π using an electrical circuit

    Science.gov (United States)

    Ocaya, R. O.

    2017-01-01

    The constant pi, or π, is one of the oldest and most recognizable irrational constants. It was known from the earliest days of mathematics and the sciences. Over the ages, many methods of varying complexity have been used to estimate π. This article presents a novel experimental method to estimate π using direct, digital voltmeter measurements on a simple precision full-wave rectifier circuit. We discuss the method in the context of error encroachment, and suggest the possibility to estimate total harmonic distortion simply. The experiment is repeatable and of value to the undergraduate physics and electronics laboratory, while adding to a celebration of π.

  14. 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

  15. Circadian rhythms in biologically closed electrical circuits of plants.

    Science.gov (United States)

    Volkov, Alexander; Waite, Astian J; Wooten, Joseph D; Markin, Vladislav S

    2012-02-01

    The circadian clock regulates a wide range of electrophysiological and developmental processes in plants. Here, we discuss the direct influence of a circadian clock on biologically closed electrochemical circuits in vivo. The biologically closed electrochemical circuits in the leaves of C. miniata (Kaffir lily), Aloe vera and Mimosa pudica, which regulate their physiology, were analyzed using the charge stimulation method. Plants are able to memorize daytime and nighttime. Even at continuous light or darkness, plants recognize nighttime or daytime and change the input resistance. The circadian clock can be maintained endogenously and has electrochemical oscillators, which can activate ion channels in biologically closed electrochemical circuits. The activation of voltage gated channels depends on the applied voltage, electrical charge, and the speed of transmission of electrical energy from the electrostimulator to plants.

  16. On the Possibility of the Jerk Derivative in Electrical Circuits

    Directory of Open Access Journals (Sweden)

    J. F. Gómez-Aguilar

    2016-01-01

    Full Text Available A subclass of dynamical systems with a time rate of change of acceleration are called Newtonian jerky dynamics. Some mechanical and acoustic systems can be interpreted as jerky dynamics. In this paper we show that the jerk dynamics are naturally obtained for electrical circuits using the fractional calculus approach with order γ. We consider fractional LC and RL electrical circuits with 1⩽γ<2 for different source terms. The LC circuit has a frequency ω dependent on the order of the fractional differential equation γ, since it is defined as ω(γ=ω0γγ1-γ, where ω0 is the fundamental frequency. For γ=3/2, the system is described by a third-order differential equation with frequency ω~ω03/2, and assuming γ=2 the dynamics are described by a fourth differential equation for jerk dynamics with frequency ω~ω02.

  17. Turkish Students' Conceptions about the Simple Electric Circuits

    Science.gov (United States)

    Cepni, Salih; Keles, Esra

    2006-01-01

    In this study, the Turkish students' understanding level of electric circuits consisting of two bulbs and one battery was investigated by using open-ended questions. Two-hundred fifty students, whose ages range from 11 to 22, were chosen from five different groups at primary, secondary and university levels in Trabzon in Turkey. In analyzing…

  18. 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 students…

  19. Web-Based Trainer for Electrical Circuit Analysis

    Science.gov (United States)

    Weyten, L.; Rombouts, P.; De Maeyer, J.

    2009-01-01

    A Web-based system for training electric circuit analysis is presented in this paper. It is centered on symbolic analysis techniques and it not only verifies the student's final answer, but it also tracks and coaches him/her through all steps of his/her reasoning path. The system mimics homework assignments, enhanced by immediate personalized…

  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. Simulating Harmonic Oscillator and Electrical Circuits: A Didactical Proposal

    Science.gov (United States)

    Albano, Giovannina; D'Apice, Ciro; Tomasiello, Stefania

    2002-01-01

    A Mathematica[TM] package is described that uses simulations and animations to illustrate key concepts in harmonic oscillation and electric circuits for students not majoring in physics or mathematics. Students are not required to know the Mathematica[TM] environment: a user-friendly interface with buttons functionalities and on-line help allows…

  2. Hamilton´s Principle and Electric Circuits Tudory

    Directory of Open Access Journals (Sweden)

    Daniel Mayer

    2006-01-01

    Full Text Available 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.

  3. EGATEC: A new high-resolution engineering model of the global atmospheric electric circuit—Currents in the lower atmosphere

    Science.gov (United States)

    Odzimek, A.; Lester, M.; Kubicki, M.

    2010-09-01

    We present a new high-resolution model of the Earth's global atmospheric electric circuit (GEC) represented by an equivalent electrical network. Contributions of clouds to the total resistance of the atmosphere and as current generators are treated more realistically than in previous GEC models. The model of cloud current generators is constructed on the basis of the ISCCP cloud data and the OTD/LIS lightning flash rates and TRMM rainfall data. The current generated and the electric resistance can be estimated with a spatial resolution of several degrees in latitude and longitude and 3 hour time resolution. The resistance of the atmosphere is calculated using an atmospheric conductivity model which is spatially dependent and sensitive to the level of solar activity. An equivalent circuit is constructed assuming the ionosphere and ground are ideal conductors. The circuit solution provides diurnal variations of the ionospheric potential and the GEC global current at the 3 hour time resolution as well as the global distributions and diurnal variations of the air-Earth current density and electric field. The model confirms that the global atmospheric electric activity peaks daily at ˜21 UT. The diurnal variation of the ionospheric potential and the global current have a maximum at 12 and 21-24 UT in July and at 9 and 21 UT in December, and a global minimum at 3-6 UT independent of season. About 80% of the current is generated by thunderstorm convective clouds and 20% by mid-level rain clouds.

  4. 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.

  5. Adaptation of an Evolutionary Algorithm in Modeling Electric Circuits

    Directory of Open Access Journals (Sweden)

    J. Hájek

    2010-01-01

    Full Text Available This paper describes the influence of setting control parameters of a differential evolutionary algorithm (DE and the influence of adapting these parameters on the simulation of electric circuits and their components. Various DE algorithm strategies are investigated, and also the influence of adapting the controlling parameters (Cr, F during simulation and the effect of sample size. Optimizing an equivalent circuit diagram is chosen as a test task. Several strategies and settings of a DE algorithm are evaluated according to their convergence to the right solution. 

  6. The Role of Anomalous Data in Restructuring Fourth Graders' Frameworks for Understanding Electric Circuits.

    Science.gov (United States)

    Shepardson, Daniel P.; Moje, Elizabeth B.

    1999-01-01

    Focuses on students' understanding of electric circuits. Findings suggest that children's interpretive frameworks of electric circuits are reflected in the specificity of the details, consistency, and coherence of their understanding. Contains 23 references. (DDR)

  7. 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.

  8. 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.

  9. 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...

  10. 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...

  11. 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...

  12. Transformer Winding Deformation Profile using Modified Electrical Equivalent Circuit

    Directory of Open Access Journals (Sweden)

    M. Arul Sathya

    2015-02-01

    Full Text Available This study presents a generalized methodology to predict the transformer winding deformation profile through Sweep Frequency Response Analysis using Finite Element Method based Magneto Structural Analysis and proposed modified equivalent circuit. Monitoring and diagnosis of fault in any power apparatus is necessary to increase the quality life of the apparatus. In general all the power transformers are designed to withstand the mechanical forces due to short circuit faults. However, mechanical forces may exceed the specified limits during severe incidents leading to winding deformation. Winding deformation is one of the causes for the power transformer outages. In the present work, deformation profile of the winding for different short circuit currents are computed using Finite Element Method based Magneto-structural analysis. The change in circuit parameters of the deformed windings are computed using Finite Element Method based field analyses and the corresponding Sweep Frequency Responses are obtained using the modified electrical equivalent circuit. From the change in resonance frequencies, the displacement profile of the winding can be predicted which will be useful for design engineers to check the withstand capability of transformer.

  13. Competitive Learning in Electric Circuit Theory Using MOODLE

    Science.gov (United States)

    Barroso, Ramón J. Durán; Bahillo, Alfonso; Fernández, Patricia; Merayo, Noemí; de Miguel, Ignacio; Aguado, Juan Carlos; Lorenzo, Rubén M.; Domi, Evaristo J. Abril

    We have recently introduced an activity based on competitive learning in the subject of "Electric Circuit Theory", which is taught in the first year of the 3-year degree of Technical Telecommunication Engineering at the University of Valladolid. Students are divided into groups and compete in a tournament through a series of knockout rounds. In each of these rounds, a contending group solves an electric circuit problem, and proposes an update on it, which must then be solved by the other contending team, and so on until one of them fails. In order to facilitate the management of the game, the open-source MOODLE platform has been employed. This paper describes the experience and the learning benefits that it brings, as well as how the method has been implemented using the MOODLE platform. Moreover, the satisfaction of the students and the time required by the students and by the teacher when using this technique are also analyzed. While the experience focuses on the subject of "Electric Circuit Theory", it is worthy to note that it may be easily extended to other subjects.

  14. Justification of equivalent substitution circuits used to optimize the dissipative properties of electroelastic bodies with external electric circuits

    Science.gov (United States)

    Ivanov, A. S.; Matvienko, V. P.; Oshmarin, D. A.; Sevodina, N. V.; Yurlov, M. A.; Yurlova, N. A.

    2016-05-01

    We consider elastoplastic systems which are piecewise homogeneous bodies composed of piezoelectric elements some of which have piezoelectrical properties. Electric series circuits consisting of resistors, capacitors, and inductance coils are applied to piezoelectric elements through the electrode coating on the body surface. The goal of the study is to develop efficient methods of mathematical modelling for determining the parameters of elements of the external electric circuit, which ensure, at prescribed resonance frequencies, the maximum damping properties of electroelastic bodies with external electric circuits. To choose effective circuits for solving the problem posed above, we suggest to pose the problem of natural vibrations of elastic bodies whose elements exhibit piezoeffect and have external electric circuits.As the most efficient approaches for calculating the electric circuit parameters necessary for the maximal damping, we propose some versions of equivalent circuits, which can be used to substitute elastic systems with piezoelectric elements. The most reliable equivalent substitution circuits are justified on the basis of the proposed problem of natural vibrations. Numerical results are obtained for a cantilever plate with a piezoelement connected through the electrode coated surface with a series electric circuit consisting of resistors, capacitors and inductance coils.

  15. ELECTRICAL EQUIVALENT CIRCUIT OF BIOLOGICAL OBJECTS OF VEGETABLE

    Directory of Open Access Journals (Sweden)

    I. M. Golev

    2014-01-01

    Full Text Available Summary.The results of measurements of complex biological tissues electrical resistance of vegetable origin are presented. The measurements were performed at T=296 K in the frequency range from 5 to 500 kHz. As the electrodes were covered with tin (purity of 99.9% copper plates.. Experimentally investigated the following objects: samples parenchymal tissue of Apple in the form of cylinders with a diameter of 20 mm and a length of 20 mm; Apple juice, obtained by mechanical destruction of cells; pressed Apple pulp (juice content of not more than 20%obtained by the centrifugal separation, which destroyed the system of cells. For plant tissue with a holistic system of cells in the field 103 - 105 Hz is observed pronounced minimum angle of phase shift. In the absence of cells and its value is greatly reduced .The equivalent electrical circuit fabrics are considered. The calculation of all its elements is made. The equivalent capacitance of the electrical double layer at the interface of metal measuring electrode and extracellular fluid is element of C1 . The electrical resistance of this layer alternating current is characterized by the element R1 . Chain parallel connected resistance and capacitance describes the system of plant cells. The capacitance C2 is due to the electrical capacity of the cell membranes, and the resistance R2 is the electrical resistance of the membranes and intracellular space.The coincidence of experimental and calculated data in a frequency range of more than 103 Hz satisfactory. In the region of lower frequencies is observed differences. This may be due to the specific behavior of the electrical double layer. However, in the frequency region where the electrical properties of the cell structure of the investigated tissue match good, which proves the validity of the considered equivalent circuit. It is shown that the value of the complex electrical impedance of vegetable tissue in the frequency range from 103 Hz to 105

  16. Oscillatory localization of quantum walks analyzed by classical electric circuits

    Science.gov (United States)

    Ambainis, Andris; PrÅ«sis, Krišjānis; Vihrovs, JevgÄ`nijs; Wong, Thomas G.

    2016-12-01

    We examine an unexplored quantum phenomenon we call oscillatory localization, where a discrete-time quantum walk with Grover's diffusion coin jumps back and forth between two vertices. We then connect it to the power dissipation of a related electric network. Namely, we show that there are only two kinds of oscillating states, called uniform states and flip states, and that the projection of an arbitrary state onto a flip state is bounded by the power dissipation of an electric circuit. By applying this framework to states along a single edge of a graph, we show that low effective resistance implies oscillatory localization of the quantum walk. This reveals that oscillatory localization occurs on a large variety of regular graphs, including edge-transitive, expander, and high-degree graphs. As a corollary, high edge connectivity also implies localization of these states, since it is closely related to electric resistance.

  17. 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

  18. 30 CFR 18.51 - Electrical protection of circuits and equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electrical protection of circuits and equipment... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.51 Electrical protection of circuits and equipment. (a) An...

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

    Energy Technology Data Exchange (ETDEWEB)

    Pahlavani, H., E-mail: h-pahlavani@qom.ac.ir; Kolur, E. Rahmanpour

    2016-08-15

    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.

  20. 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.

  1. On Parameterization of the Global Electric Circuit Generators

    Science.gov (United States)

    Slyunyaev, N. N.; Zhidkov, A. A.

    2016-08-01

    We consider the problem of generator parameterization in the global electric circuit (GEC) models. The relationship between the charge density and external current density distributions inside a thundercloud is studied using a one-dimensional description and a three-dimensional GEC model. It is shown that drastic conductivity variations in the vicinity of the cloud boundaries have a significant impact on the structure of the charge distribution inside the cloud. Certain restrictions on the charge density distribution in a realistic thunderstorm are found. The possibility to allow for conductivity inhomogeneities in the thunderstorm regions by introducing an effective external current density is demonstrated. Replacement of realistic thunderstorms with equivalent current dipoles in the GEC models is substantiated, an equation for the equivalent current is obtained, and the applicability range of this equation is analyzed. Relationships between the main GEC characteristics under variable parameterization of GEC generators are discussed.

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

    DEFF Research Database (Denmark)

    Tamaseviciute, E.; Tamasevicius, A.; Mykolaitis, G.;

    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...

  3. Method of boundary testing of the electric circuits and its application for calculating electric tolerances. [electric equipment tests

    Science.gov (United States)

    Redkina, N. P.

    1974-01-01

    Boundary testing of electric circuits includes preliminary and limiting tests. Preliminary tests permit determination of the critical parameters causing the greatest deviation of the output parameter of the system. The boundary tests offer the possibility of determining the limits of the fitness of the system with simultaneous variation of its critical parameters.

  4. 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...

  5. 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.

    2016-11-01

    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.

  6. 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.

  7. 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…

  8. Factors Mediating the Effect of Gender on Ninth-Grade Turkish Students' Misconceptions Concerning Electric Circuits

    Science.gov (United States)

    Sencar, Selen; Eryilmaz, Ali

    2004-01-01

    This study was designed to identify and analyze possible factors that mediate the effect of gender on ninth-grade Turkish students' misconceptions concerning electric circuits. A Simple Electric Circuit Concept Test (SECCT), including items with both practical and theoretical contexts, and an Interest-Experience Questionnaire about Electricity…

  9. Pre-Service and In-Service Physics Teachers' Ideas about Simple Electric Circuits

    Science.gov (United States)

    Kucukozer, Huseyin; Demirci, Neset

    2008-01-01

    The aim of the study is to determine pre-service and high school physics teachers' ideas about simple electric circuits. In this study, a test containing eight questions related to simple electric circuits was given to the pre-service physics teachers (32 subjects) that had graduated from Balikesir University, Necatibey Faculty of Education, the…

  10. Short-term solar wind modulation of the global electric circuit

    Science.gov (United States)

    Engfer, Daniel William

    Five separate key day sets are used to determine correlations between two candidate solar wind mechanisms and changes in atmospheric parameters at Mauna Loa Observatory in Hawaii and Colaba Observatory in India. We evaluate responses of these parameters to external modulation of the global electric circuit by the solar wind using the superposed epoch method of analysis. The results are interpreted in terms of a simplified global electric circuit model with two parallel return paths, one at low to middle geomagnetic latitudes and the other at middle to high geomagnetic latitudes. We find responses similar to those expected from external modulation, but of marginal statistical significance. The Mauna Loa set contains current density, potential gradient and positive and negative conductivity data for the 1976-1984 period, while the Colaba set contains potential gradient data through the 1936-1966 period. A data reduction technique is devised to increase the signal to noise ratio of our results by removing noisy data and periodic variations from these ground-based data sets. Throughout this process diurnal and annual variations of these parameters at both sites are evaluated and compared with available observations by other researchers. Using two separate key day sets and data from the Dynamics Explorer 2 satellite for the August 1981 to February 1983 time period, we endeavor to determine correlations between changes in ionospheric horizontal potential gradients and solar wind related physical inputs using superposed epoch analysis. In this manner, responses to external inputs are revealed for potential gradients of various latitudinal extents 5md ranges of local time. The local time variation is evaluated and subtracted from all potential gradients to increase the signal to noise ratio of the results. We also consider the possible effects of solar wind-modulated ionospheric potential gradients on the global electric circuit.

  11. New equivalent lumped electrical circuit for piezoelectric transformers.

    Science.gov (United States)

    Gonnard, Paul; Schmitt, P M; Brissaud, Michel

    2006-04-01

    A new equivalent circuit is proposed for a contour-vibration-mode piezoelectric transformer (PT). It is shown that the usual lumped equivalent circuit derived from the conventional Mason approach is not accurate. The proposed circuit, built on experimental measurements, makes an explicit difference between the elastic energies stored respectively on the primary and secondary parts. The experimental and theoretical resonance frequencies with the secondary in open or short circuit are in good agreement as well as the output "voltage-current" characteristic and the optimum efficiency working point. This circuit can be extended to various PT configurations and appears to be a useful tool for modeling electronic devices that integrate piezoelectric transformers.

  12. 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.

  13. 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.

  14. 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...

  15. Study on the Sensitivity of Landmine Electrical Fuse Circuit Under the Interference of Natural Electromagnetic Pulse

    Science.gov (United States)

    Qin, Dechun

    Landmine electrical fuse circuits on the battlefield will be interfered by natural electromagnetic pulse such as electrostatic discharge and lightning, which will undermine the circuit performance and trigger the early burst or mistaken burst of the landmines. In this paper, numerically simulation analysis is conducted on the electrostatic and lightning effects received by the landmine fuse circuit by means of building simulation model of the fuse circuit and analyzing the electric and magnetic field changes of the observation The mechanism of the influence of electrostatic discharge and lightning on the sensitivity of the fuse circuit is explored. The conclusion is that electrostatic effect cause the mistaken burst of the landmines by enabling the interference voltage to reach the components turn-on threshold and cause the circuit malfunction, and lighting effect by long period accumulation of energy.

  16. 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...

  17. Analysis of a Piezo Electric Driver Circuit for Use in a Fabry-Perot Interferometer

    Directory of Open Access Journals (Sweden)

    Maithya J. Mutuku

    2013-09-01

    Full Text Available The design and fabrication of piezo electric driver circuit is presented and analysed. The output voltage which is a triangular wave voltage and frequency of the driver circuit were measured and set at 80 V peak to peak and an output frequency of 1 KHz. A photo detector circuit which receives the output beam from the confocal Fabry- perot interferometer (CFPI through the photodiode is as well presented

  18. 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…

  19. 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.

  20. QUANTUM FLUCTUATIONS IN MESOSCOPIC RESISTANCE INDUCTANCE-CAPACITANCE ELECTRIC CIRCUITS AT FINITE TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    LIANG XIAN-TING; FAN HONG-YI

    2001-01-01

    By using the charge and current in a quantization resistance-inductance-capacitance (RLC) electric circuit, we construct a pair of canonical variables. Using this pair of variables and the thermal field dynamics, we obtain the fluctuations of charge and current in the RLC electric circuit at finite temperatures. It is shown that the fluctuations increase with increasing temperature and decrease with prolonging of time.

  1. 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.

  2. 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.

  3. Manipulating the quantum state of an electrical circuit.

    Science.gov (United States)

    Vion, D; Aassime, A; Cottet, A; Joyez, P; Pothier, H; Urbina, C; Esteve, D; Devoret, M H

    2002-05-03

    We have designed and operated a superconducting tunnel junction circuit that behaves as a two-level atom: the "quantronium." An arbitrary evolution of its quantum state can be programmed with a series of microwave pulses, and a projective measurement of the state can be performed by a pulsed readout subcircuit. The measured quality factor of quantum coherence Qphi approximately 25,000 is sufficiently high that a solid-state quantum processor based on this type of circuit can be envisioned.

  4. Prolonged silicon carbide integrated circuit operation in Venus surface atmospheric conditions

    Directory of Open Access Journals (Sweden)

    Philip G. Neudeck

    2016-12-01

    Full Text Available The prolonged operation of semiconductor integrated circuits (ICs needed for long-duration exploration of the surface of Venus has proven insurmountably challenging to date due to the ∼ 460 °C, ∼ 9.4 MPa caustic environment. Past and planned Venus landers have been limited to a few hours of surface operation, even when IC electronics needed for basic lander operation are protected with heavily cumbersome pressure vessels and cooling measures. Here we demonstrate vastly longer (weeks electrical operation of two silicon carbide (4H-SiC junction field effect transistor (JFET ring oscillator ICs tested with chips directly exposed (no cooling and no protective chip packaging to a high-fidelity physical and chemical reproduction of Venus’ surface atmosphere. This represents more than 100-fold extension of demonstrated Venus environment electronics durability. With further technology maturation, such SiC IC electronics could drastically improve Venus lander designs and mission concepts, fundamentally enabling long-duration enhanced missions to the surface of Venus.

  5. 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...

  6. Magnetospheric effects in atmospheric electricity at high latitudes

    Science.gov (United States)

    Shumilov, O. I.; Kasatkina, E. A.; Frank-Kamenetsky, A. V.; Raspopov, O. M.; Vasiljev, A. N.; Struev, A. G.

    2003-04-01

    Measurements of the vertical atmospheric electric field (Ez) made at auroral station Apatity (geomagnetic latitude: 63.8) and polar cap station Vostok, Antarctica (geomagnetic latitude: -89.3) in 2001-2002 have been analyzed. The measurements were made by a high-latitude computer-aided complex installed at Apatity in 2001. It consists of three spatially placed microbarographs for measurements of atmospheric waves, a device for air conductivity measurement and a device for measurement of vertical component of the atmospheric electric field. The computer-aided system permits to get information with a frequency of five times per second. The ground level atmospheric electric field was found to have systematic local diurnal and seasonal variations. Diurnal variations of atmospheric potential gradient were found to have a departure from the Carnegie curve. A distinct difference in the diurnal variation of atmospheric electric field has been observed also between disturbed (Kp>30) and extremely quiet (Kplatitude electric field variations appear to be the result of solar wind-magnetosphere-ionosphere coupling. Besides, we have found the similarity between the diurnal course of the atmospheric electric field under the quiet geomagnetic conditions and the diurnal variation of galactic cosmic rays. These results have been explained in terms of calculated effective Bz component of the interpalnetary magnetic field arising due to variation of the geomagnetic dipole axis inclination during the Earth's rotation. The results of analysis of the influence of extreme weather conditions (rain, snow, snowstorm, stormclouds, thunderstorms, lightning) on atmospheric electricity (electric field and conductivity) are also discussed. This work was supported by EC (grant INTAS 97-31008) and RFBR (grant 01-05-64850).

  7. 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.

  8. Dynamics of Undisturbed Midlatitude Atmospheric Electricity: From Observations to Scaling

    Science.gov (United States)

    Anisimov, S. V.; Afinogenov, K. V.; Shikhova, N. M.

    2014-04-01

    Long-term dynamics of the electric field of the midlatitude near-surface atmosphere in a wide range of temporal scales is analyzed according to multiyear observatory and seasonal field observations. It is found that the daily dynamics of the aeroelectric field at mid-latitudes most authentically repeats a diurnal variation for the winter months. It is stated that short-period pulsations of the electric field have a self-similar power-law spectrum. Spatio-temporal scales of the self-similarity interval are estimated and the nature of the generalized diffusive process of the aeroelectric pulsation generation is defined. Characteristics of the turbulent ΔE pulsations are analyzed. Estimates of interrelation between the dynamic (fractal dimensions, intermittency indices) and power (degrees of spectral index and structure function) ΔE characteristics are obtained. Mutual correlations between atmospheric electric field variations, vertical atmospheric electrical current density, space charge density, and atmospheric electrical conductivity are studied. It is shown that variations of the light atmospheric ion number density and space charge density are related with variations of the Radon-222 emanations. Spectral analysis of the space charge density variations is carried out. It is shown that the electrodynamic state of the surface atmosphere depends on the convective state of the atmospheric boundary layer.

  9. Analysis and calculation of lightning-induced voltages in aircraft electrical circuits

    Science.gov (United States)

    Plumer, J. A.

    1974-01-01

    Techniques to calculate the transfer functions relating lightning-induced voltages in aircraft electrical circuits to aircraft physical characteristics and lightning current parameters are discussed. The analytical work was carried out concurrently with an experimental program of measurements of lightning-induced voltages in the electrical circuits of an F89-J aircraft. A computer program, ETCAL, developed earlier to calculate resistive and inductive transfer functions is refined to account for skin effect, providing results more valid over a wider range of lightning waveshapes than formerly possible. A computer program, WING, is derived to calculate the resistive and inductive transfer functions between a basic aircraft wing and a circuit conductor inside it. Good agreement is obtained between transfer inductances calculated by WING and those reduced from measured data by ETCAL. This computer program shows promise of expansion to permit eventual calculation of potential lightning-induced voltages in electrical circuits of complete aircraft in the design stage.

  10. Teaching electric circuits with multiple batteries: A qualitative approach

    Directory of Open Access Journals (Sweden)

    David P. Smith*

    2011-11-01

    Full Text Available 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 reasoning based on current and resistance where reasoning based on voltage is a necessity. We also found that problems such as thinking of the battery as a source of constant current resurfaced in this new context, and that answers given were inconsistent with current conservation. We describe the curriculum we developed that enables students to model circuits with multiple batteries qualitatively. Post-test results show that the majority of students were able to apply their newly developed model to make accurate predictions for complex circuits.

  11. The Use of Enhanced Guided Notes in an Electric Circuit Class: An Exploratory Study

    Science.gov (United States)

    Lawanto, O.

    2012-01-01

    This study was conducted to evaluate students' (n=70) learning performance after their participation in lectures using enhanced guided notes (EGN) in an electric circuits course for non-electrical engineering students. Unlike traditional guided notes, EGN include questions that prompt students to evaluate their metacognitive knowledge. The results…

  12. 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…

  13. Fundamental electric circuit elements based on the linear and nonlinear magnetoelectric effects (Presentation Recording)

    Science.gov (United States)

    Sun, Young; Shang, Dashan; Chai, Yisheng; Cao, Zexian; Lu, Jun

    2015-09-01

    From the viewpoint of electric circuit theory, the three fundamental two-terminal passive circuit elements, resistor R , capacitor C, and inductor L, are defined in terms of a relationship between two of the four basic circuit variables, charge q, current i, voltage v, and magnetic flux φ. From a symmetry concern, there should be a fourth fundamental element defined from the relationship between charge q and magnetic flux φ. Here we present both theoretical analysis and experimental evidences to demonstrate that a two-terminal passive device employing the magnetoelectric (ME) effects can exhibit a direct relationship between charge q and magnetic flux φ, and thus is able to act as the fourth fundamental circuit element. The ME effects refer to the induction of electric polarization by a magnetic field or magnetization by an electric field, and have attracted enormous interests due to their promise in many applications. However, no one has linked the ME effects with fundamental circuit theory. Both the linear and nonlinear-memory devices, termed transtor and memtranstor, respectively, have been experimentally realized using multiferroic materials showing strong ME effects. Based on our work, a full map of fundamental two-terminal circuit elements is constructed, which consists of four linear and four nonlinear-memory elements. This full map provides an invaluable guide to developing novel circuit functionalities in the future.

  14. Design of pressure-driven microfluidic networks using electric circuit analogy.

    Science.gov (United States)

    Oh, Kwang W; Lee, Kangsun; Ahn, Byungwook; Furlani, Edward P

    2012-02-07

    This article reviews the application of electric circuit methods for the analysis of pressure-driven microfluidic networks with an emphasis on concentration- and flow-dependent systems. The application of circuit methods to microfluidics is based on the analogous behaviour of hydraulic and electric circuits with correlations of pressure to voltage, volumetric flow rate to current, and hydraulic to electric resistance. Circuit analysis enables rapid predictions of pressure-driven laminar flow in microchannels and is very useful for designing complex microfluidic networks in advance of fabrication. This article provides a comprehensive overview of the physics of pressure-driven laminar flow, the formal analogy between electric and hydraulic circuits, applications of circuit theory to microfluidic network-based devices, recent development and applications of concentration- and flow-dependent microfluidic networks, and promising future applications. The lab-on-a-chip (LOC) and microfluidics community will gain insightful ideas and practical design strategies for developing unique microfluidic network-based devices to address a broad range of biological, chemical, pharmaceutical, and other scientific and technical challenges.

  15. Electromagnetic noise in electric circuits: Ringing and resonance phenomena in the common mode

    Directory of Open Access Journals (Sweden)

    Shuji Kitora

    2014-11-01

    Full Text Available It is generally believed that electromagnetic noise originates from the coupling of electric signals in a circuit with electric signals in surrounding materials in the environment. However, the noise phenomenon had not been quantified until now. In order to study the phenomenon of noise, we considered a standard circuit (two transmission lines, to which an additional transmission line was introduced in order to explicitly take into account the effect of conductors in the environment. We performed calculations using a newly developed multiconductor transmission-line theory for the resulting three-line circuit in order to determine the magnitude of the coupling between the circuit and the conductors in the environment under various conditions. We observed ringing and resonance phenomena in the common mode, which influenced the performance of the normal mode as electromagnetic noise. Our findings were confirmed by recent experiments in which conductor lines were arranged in various ways using a printed circuit board (PCB. The ordinary usage of electricity in the standard electric circuit was found to be worst in exciting the common mode noise.

  16. 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.

  17. 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.

  18. [About optimized designs and circuits of autonomous electric stimulators for the gastrointestinal tract].

    Science.gov (United States)

    Glushchuk, S F

    2004-01-01

    Described in the paper are the key principles of designing of autonomous electrodes for the gastrointestinal tract (AE GT) as well as circuits of stimulating-pulse generators. A shape for the electric-stimulator frame, its geometric dimensions and choice of a material for electrodes are substantiated. The electric- and trauma-safety of AE GT is discussed. The main stimulating current parameters, as well as the flowchart and design of the electric stimulator are presented.

  19. Possible Solar Influence On Atmospheric Electric Field

    CERN Document Server

    Sikka, P; Murty, A S R; Murty, B V R; Sikka, Poonam; Murty, Bh.V. Ramana; Murty, A S Ramachandra

    1998-01-01

    A cell dynamical system model for the troposphere - ionosphere coupling is proposed . Vertical mass exchange in the troposphere-ionosphere-magnetosphere takes place through a chain of eddy systems. Any perturbation in the troposphere would be transmitted to ionosphere and vice versa. A global perturbation in ionosphere, as the one caused by solar variability, is transmitted to troposphere influencing weather systems/geomagnetic/atmospheric electrification processes.

  20. Measuring user similarity using electric circuit analysis: application to collaborative filtering.

    Science.gov (United States)

    Yang, Joonhyuk; Kim, Jinwook; Kim, Wonjoon; Kim, Young Hwan

    2012-01-01

    We propose a new technique of measuring user similarity in collaborative filtering using electric circuit analysis. Electric circuit analysis is used to measure the potential differences between nodes on an electric circuit. In this paper, by applying this method to transaction networks comprising users and items, i.e., user-item matrix, and by using the full information about the relationship structure of users in the perspective of item adoption, we overcome the limitations of one-to-one similarity calculation approach, such as the Pearson correlation, Tanimoto coefficient, and Hamming distance, in collaborative filtering. We found that electric circuit analysis can be successfully incorporated into recommender systems and has the potential to significantly enhance predictability, especially when combined with user-based collaborative filtering. We also propose four types of hybrid algorithms that combine the Pearson correlation method and electric circuit analysis. One of the algorithms exceeds the performance of the traditional collaborative filtering by 37.5% at most. This work opens new opportunities for interdisciplinary research between physics and computer science and the development of new recommendation systems.

  1. A Bistable Microelectronic Circuit for Sensing Extremely Low Electric Field

    Science.gov (United States)

    2010-01-01

    schematic of a single element is shown in Fig. 2. It consists of two differential pairs that employ negative- positive-negative NPN transistors with...been transformed into a current Isig that is then amplified by the NPN transistor . In fact, the circuit responds to very small on the order of pico...one of them being cross coupled, two positive channel metal oxide semiconduc- tor PMOS transistors , and a pair of resistors. In each dif- ferential

  2. Responses of atmospheric electric field and air-earth current to variations of conductivity profiles

    Science.gov (United States)

    Makino, M.; Ogawa, T.

    1984-05-01

    A global circuit model is constructed to study responses of air-earth current and electric field to a variation of atmospheric electrical conductivity profile. The model includes the orography and the global distribution of thunderstorm generators. The conductivity varies with latitude and exponentially with altitude. The thunderstorm cloud is assumed to be a current generator with a positive source at the top and a negative one at the bottom. The UT diurnal variations of the global current and the ionospheric potential are evaluated considering the local-time dependence of thunderstorm activity. The global distribution of the electric field and the air-earth current are affected by the orography and latitudinal effects. Assuming a variation of conductivity profile, responses of atmospheric electrical parameters are investigated. The nonuniform decrement of the conductivity with altitude increases both the electric field and the air-earth current. The result suggests a possibility that the increment of the electric field and the air-earth current after a solar flare may be caused by this scheme, due to Forbush decrease.

  3. 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...

  4. New equivalent-electrical circuit model and a practical measurement method for human body impedance.

    Science.gov (United States)

    Chinen, Koyu; Kinjo, Ichiko; Zamami, Aki; Irei, Kotoyo; Nagayama, Kanako

    2015-01-01

    Human body impedance analysis is an effective tool to extract electrical information from tissues in the human body. This paper presents a new measurement method of impedance using armpit electrode and a new equivalent circuit model for the human body. The lowest impedance was measured by using an LCR meter and six electrodes including armpit electrodes. The electrical equivalent circuit model for the cell consists of resistance R and capacitance C. The R represents electrical resistance of the liquid of the inside and outside of the cell, and the C represents high frequency conductance of the cell membrane. We propose an equivalent circuit model which consists of five parallel high frequency-passing CR circuits. The proposed equivalent circuit represents alpha distribution in the impedance measured at a lower frequency range due to ion current of the outside of the cell, and beta distribution at a high frequency range due to the cell membrane and the liquid inside cell. The calculated values by using the proposed equivalent circuit model were consistent with the measured values for the human body impedance.

  5. Stationary and nonstationary models of the global electric circuit: Well-posedness, analytical relations, and numerical implementation

    Science.gov (United States)

    Kalinin, A. V.; Slyunyaev, N. N.; Mareev, E. A.; Zhidkov, A. A.

    2014-05-01

    We analyze the formulation of the problem of global atmospheric electric circuit modeling. It was shown that under some relatively simple and widely used simplifying assumptions this problem can be reduced to finding the temporal and spatial dependencies of the electric potential on the specified generators, which are determined by the external electric current density. They correspond to thunderclouds in the real atmosphere. The ionospheric potential (the potential difference between the upper and lower atmospheric boundaries) is not specified explicitly but can be uniquely determined from the solution. The formulations of the stationary and nonstationary problems are given in terms of the potential and their well-posedness is discussed. We obtained a number of analytical relations under some restrictions on the distribution of conductivity. They include the formulas which explicitly express the ionospheric potential in terms of the problem parameters. The examples of numerical calculations using the software developed on the basis of general formulations of the stationary and nonstationary problems are demonstrated.

  6. 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

  7. Development of 3-D Mechanical Models of Electric Circuits and Their Effect on Students' Understanding of Electric Potential Difference

    Science.gov (United States)

    Balta, Nuri

    2015-01-01

    Visualizing physical concepts through models is an essential method in many sciences. While students are mostly proficient in handling mathematical aspects of problems, they frequently lack the ability to visualize and interpret abstract physical concepts in a meaningful way. In this paper, initially the electric circuits and related concepts were…

  8. Simulation of the Universal-Time Diurnal Variation of the Global Electric Circuit Charging Rate

    Science.gov (United States)

    Mackerras, D.; Darvenzia, M.; Orville, R. E.; Williams, E. R.; Goodman, S. J.

    1999-01-01

    A global lightning model that includes diurnal and annual lightning variation, and total flash density versus latitude for each major land and ocean, has been used as the basis for simulating the global electric circuit charging rate. A particular objective has been to reconcile the difference in amplitude ratios [AR=(max-min)/mean] between global lightning diurnal variation (AR approx. = 0.8) and the diurnal variation of typical atmospheric potential gradient curves (AR approx. = 0.35). A constraint on the simulation is that the annual mean charging current should be about 1000 A. The global lightning model shows that negative ground flashes can contribute, at most, about 10-15% of the required current. For the purpose of the charging rate simulation, it was assumed that each ground flash contributes 5 C to the charging process. It was necessary to assume that all electrified clouds contribute to charging by means other than lightning, that the total flash rate can serve as an indirect indicator of the rate of charge transfer, and that oceanic electrified clouds contribute to charging even though they are relatively inefficient in producing lightning. It was also found necessary to add a diurnally invariant charging current component. By trial and error it was found that charging rate diurnal variation curves in Universal time (UT) could be produced with amplitude ratios and general shapes similar to those of the potential gradient diurnal variation curves measured over ocean and arctic regions during voyages of the Carnegie Institute research vessels.

  9. 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 .

  10. Successfully Mapping the U-Tank to an Electric Circuit

    Science.gov (United States)

    Hong, Seok-In

    2010-01-01

    Water-flow analogies are helpful in understanding electricity. For example, in the Lodge model, the constant DC voltage source (a battery) is represented by a U-tank with two water columns of the same cross-sectional area connected by a horizontal duct in which a pump is installed. The pump maintains the difference of the levels of the two water…

  11. 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.

  12. The response of the earth's global electrical circuit to a solar proton event

    Science.gov (United States)

    Tzur, I.; Roble, R. G.; Reid, C. C.; Zhuang, H. C.

    An ion chemistry model of the atmosphere is used to calculate the background electric conductivity distribution and its variation during the August 1972 solar proton event and the accompanying Forbush decrease. Two-dimensional model calculations show that the solar protons significantly affect the high-latitude electrical structure of the middle atmosphere without much influence on the electrical structure of the troposphere. The maximum calculated change in the air-earth current, ground electric field, and ionospheric potential is about 10 percent which occurs during the maximum of the Forbush decrease in cosmic ray flux.

  13. Wireless Sensing System Using Open-circuit, Electrically-conductive Spiral-trace Sensor

    Science.gov (United States)

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

    2013-01-01

    A wireless sensing system includes a sensor made from an electrical conductor shaped to form an open-circuit, electrically-conductive spiral trace having inductance and capacitance. In the presence of a time-varying magnetic field, the sensor resonates to generate a harmonic response having a frequency, amplitude and bandwidth. A magnetic field response recorder wirelessly transmits the time-varying magnetic field to the sensor and wirelessly detects the sensor's response frequency, amplitude and bandwidth.

  14. 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.

  15. 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.

  16. Development of a Three-Tier Test to Assess Misconceptions about Simple Electric Circuits

    Science.gov (United States)

    Pesman, Haki; Eryilmaz, Ali

    2010-01-01

    The authors aimed to propose a valid and reliable diagnostic instrument by developing a three-tier test on simple electric circuits. Based on findings from the interviews, open-ended questions, and the related literature, the test was developed and administered to 124 high school students. In addition to some qualitative techniques for…

  17. Comparison of Parametrization Techniques for an Electrical Circuit Model of Lithium-Sulfur Batteries

    DEFF Research Database (Denmark)

    Knap, Vaclav; Stroe, Daniel Loan; Teodorescu, Remus;

    2015-01-01

    on the comparison of different parametrization methods of electrical circuit models (ECMs) for Li-S batteries. These methods are used to parametrize an ECM based on laboratory measurements performed on a Li-S pouch cell. Simulation results of ECMs are presented and compared against measurement values...

  18. Non-Contact Circuit for Real-Time Electric and Magnetic Field Measurements

    Science.gov (United States)

    2015-10-01

    primary purposes: 1) SPI communication: 3 pins for serial clock (SLCK), master output to salve input ( MOSI ) (which we use to program each output DAC...emitting diode LF low-frequency MISO master input to slave output MOSI master output to salve input PCB printed circuit board q , Q electric

  19. Student Learning in an Electric Circuit Theory Course: Critical Aspects and Task Design

    Science.gov (United States)

    Carstensen, Anna-Karin; Bernhard, Jonte

    2009-01-01

    Understanding time-dependent responses, such as transients, is important in electric circuit theory and other branches of engineering. However, transient response is considered difficult to learn since familiarity with advanced mathematical tools such as Laplace transforms is required. Here, we analyse and describe a novel learning environment…

  20. Effect of Simple Electric Circuits Teaching on Conceptual Change in Grade 9 Physics Course

    Science.gov (United States)

    Küçüközer, Hüseyin; Kocakülah, Sabri

    2008-01-01

    The aim of this study was to examine the effect of teaching designed to consider grade 9 students' misconceptions about simple electric circuits on conceptual change. Students' misconceptions were determined by using a conceptual understanding test consisting of eight open-ended questions and semi-structured interview technique. Conceptual…

  1. Current as the Key Concept of Taiwanese Students' Understandings of Electric Circuits

    Science.gov (United States)

    Tsai, Chia-Hsing; Chen, Hsueh-Yu; Chou, Ching-Yang; Lain, Kuen-Der

    2007-01-01

    The purpose of this study was to report the results of a nationwide survey of Taiwanese high schools students' understandings about electric circuits. The study involved two stratified random samples consisting of 7,145 students in Grades 8 and 9, and 2,857 students in Grade 11, accounting for about 2.3% of the total enrolment in the corresponding…

  2. Step-Wise Evolution of Mental Models of Electric Circuits: A "Learning-Aloud" Case Study.

    Science.gov (United States)

    Clement, John J.; Steinberg, Melvin S.

    2002-01-01

    Describes an approach to teaching complex models in science that uses a model construction cycle of generation, evaluation, and modification. Reports on a case study of a student in a tutoring experiment in the study of electric circuits. Focuses on the role of analogies, discrepant events, and the student's moments of surprise as motivators of…

  3. The Effect of Herrmann Whole Brain Teaching Method on Students' Understanding of Simple Electric Circuits

    Science.gov (United States)

    Bawaneh, Ali Khalid Ali; Nurulazam Md Zain, Ahmad; Salmiza, Saleh

    2011-01-01

    The purpose of this study was to investigate the effect of Herrmann Whole Brain Teaching Method over conventional teaching method on eight graders in their understanding of simple electric circuits in Jordan. Participants (N = 273 students; M = 139, F = 134) were randomly selected from Bani Kenanah region-North of Jordan and randomly assigned to…

  4. 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?" and…

  5. Encountering the Expertise Reversal Effect with a Computer-Based Environment on Electrical Circuit Analysis

    Science.gov (United States)

    Reisslein, Jana; Atkinson, Robert K.; Seeling, Patrick; Reisslein, Martin

    2006-01-01

    This study examined the effectiveness of a computer-based environment employing three example-based instructional procedures (example-problem, problem-example, and fading) to teach series and parallel electrical circuit analysis to learners classified by two levels of prior knowledge (low and high). Although no differences between the…

  6. An Analysis of Science Textbooks for Grade 6: The Electric Circuit Lesson

    Science.gov (United States)

    Sothayapetch, Pavinee; Lavonen, Jari; Juuti, Kalle

    2013-01-01

    Textbooks are a major tool in the teaching and learning process. This paper presents the results of an analysis of the Finnish and Thai 6th grade science textbooks: electric circuit lesson. Textual and pictorial information from the textbooks were analyzed under four main categories: 1) introduction of the concepts, 2) type of knowledge, 3)…

  7. Lessons Learned in the Use of WIRIS Quizzes to Upgrade Moodle to Solve Electrical Circuits

    Science.gov (United States)

    Bogarra Rodriguez, S.; Corbalan Fuertes, M.; Font Piera, A.; Plaza Garcia, I.; Solsona, F. J. A.

    2012-01-01

    WIRIS quizzes are an online mathematics tool for educational purposes that upgrade Moodle quizzes and allow the development of personalized quizzes using random data and conditional instructions. WIRIS quizzes can be used in any mathematics or science degree; their complex operators allow it to be used to solve electrical circuits. This tool…

  8. A Comparison of Experienced and Preservice Elementary School Teachers' Content Knowledge and Pedagogical Content Knowledge about Electric Circuits

    Science.gov (United States)

    Lin, Jing-Wen

    2017-01-01

    This study investigated the differences between Taiwanese experienced and preservice elementary school science teachers' content knowledge (CK) about electric circuits and their ability to predict students' preconceptions about electric circuits as an indicator of their pedagogical content knowledge (PCK). An innovative web-based recruitment and…

  9. Single-photon heat conduction in electrical circuits

    CERN Document Server

    Jones, P J; Tan, K Y; Möttönen, M

    2011-01-01

    We study photonic heat conduction between two resistors coupled weakly to a single superconducting microwave cavity. At low enough temperature, the dominating part of the heat exchanged between the resistors is transmitted by single-photon excitations of the fundamental mode of the cavity. This manifestation of single-photon heat conduction should be experimentally observable with the current state of the art. Our scheme can possibly be utilized in remote interference-free temperature control of electric components and environment engineering for superconducting qubits coupled to cavities.

  10. An electrical model of VCSEL as optical transmitter for optical printed circuit board

    Science.gov (United States)

    Kim, Do-Kyoon; Yoon, Young-Seol; Choi, Jin-Ho; Kim, Kyung-Min; Choi, Young-Wan; Lee, Seok

    2005-03-01

    Optical interconnection is recent issue for high-speed data transmission. The limitation of high-speed electrical data transmission is caused by impedance mismatching, electric field coupling, microwave loss, and different length of the electrical signal lines. To overcome these limitations, the electrical signal in the current electrical system has to be changed by the optical signal. The most suitable optical source in the OPCB (Optical Printed Circuit Board) is VCSEL (Vertical Cavity Surface Emitting Lasers) that is low-priced and has the characteristic of vertical surface emitting. In this paper, we propose an electrical model of the VCSEL as E/O converting devices for the OPCB. The equivalent circuit of the VCSEL based on the rate equations includes carrier dynamics and material properties. The rate equation parameters are obtained by full analysis based on rate equation and experiment results. The electrical model of the VCSEL has the series resistance determined by I-V characteristic curve, and the parallel capacitance by the parasitic response of the VCSEL chip. The bandwidth of the optical interconnection is analyzed considering those parameters. We design and fabricate the optical transmitter for OPCB considering proposed electrical model of VCSEL.

  11. Physical proof of the occurrence of the Braess Paradox in electrical circuits

    Science.gov (United States)

    Nagurney, Ladimer S.; Nagurney, Anna

    2016-07-01

    The Braess Paradox is the counterintuitive phenomenon that can occur in a user-optimized network system, such as a transportation network, where adding an additional link to the network increases the cost (travel time) for every user. In electrical circuits, electrons, analogous to drivers in a transportation network, traverse the network so that no electron can unilaterally change its cost (voltage drop) from an origin to a destination. In this paper, we show that the Braess Paradox can occur in electrical circuits consisting of diodes and resistors. We report measurements confirming the occurrence of the Braess Paradox in two different circuits, one with highly nonlinear link cost functions (I\\text-V characteristics). These measurements show that the voltage increases, rather than decreases, when a link is added to the circuit under constant demand (current). This discovery identifies novel circuits in which the voltage and current can be independently adjusted. It also yields insights into the Braess Paradox and transportation networks through a new computational mechanism.

  12. Circuit models of the passive electrical properties of frog skeletal muscle fibers.

    Science.gov (United States)

    Valdiosera, R; Clausen, C; Eisenberg, R S

    1974-04-01

    The relation between the fine structure, electric field equations, and electric circuit models of skeletal muscle fibers is discussed. Experimental evidence illustrates the profound variation of potential with circumferential position, even at low frequencies (100 Hz). Since one-dimensional cable theory cannot account for such variation, three-dimensional cable theory must be used. Several circuit models of a sarcomere are presented and plots are made of the predicted phase angle between sinusoidal applied current and potential. The circuit models are described by equations involving normalized variables, since they affect the phase plot in a relatively simple way. A method is presented for estimating the values of the circuit elements and the standard deviation of the estimates. The reliability of the estimates is discussed. An objective measure of fit, Hamilton's R test, is used to test the significance of different fits to data. Finally, it is concluded that none of the proposed circuit models provides an adequate description of the observed variation of phase angle with circumferential location. It is not clear whether the source of disagreement is inadequate measurements or inadequate theory.

  13. 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)

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

    Directory of Open Access Journals (Sweden)

    Miguel Durán-Sindreu

    2012-04-01

    Full Text Available 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 well as key applications, will be considered.

  15. 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.

  16. Influence of the Earth s Corotation Field on the Atmospheric Electricity: Latitudinal Variation and Response to the Solar Activity

    Science.gov (United States)

    Dumin, Y.

    Influence of the magnetospheric convection field on the atmospheric electricity is widely studied, both theoretically and experimentally, from the early 1970s. On the other hand, a considerably less attention was paid to the effects of plasmaspheric corotation field, since it was usually believed that the electric field of corotation of the solid Earth is fitted smoothly to the corotation field of plasmasphere, so that no potential difference is formed between them in the lower atmosphere. A conjecture on the important role of corotation field in the global atmospheric-electric circuit was done a few years ago in [P.A. Bespalov, Yu.V. Chugunov, J. Atmos. Terr. Phys., 1996, v.58, p.601] and several subsequent works. Unfortunately, because of using an oversimplified model of plasmasphere (in the form of a spherically-symmetric envelope with isotropic conductivity and rigid-body rotation), no reliable numerical estimates were derived, and no comparison with experimental distributions of the atmospheric electric field could be conducted. The main aim of the present report is to study the corotation effects in the framework of a considerably more realistic analytical model, where conductivity of the plasmasphere is strongly anisotropic, and the magnetic field lines are substantially distorted (stretched to "infinity") in the polar regions. Escape of polarization electric charges along the distorted field lines results in appreciable decrease (by 10-15 V/m) in the average atmospheric electric field at high latitudes. Such phenomenon was experimentally discovered as early as the International Geophysical Year (1957-1958) but was not quantitatively explained by now. Yet another interesting effect following from our model is changing the high-latitude electric field due to variations in the degree of distortion of the magnetic field lines at different levels of the solar activity. These transient changes in the atmospheric electricity should be symmetric about the noon

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Simultaneous Measurements of Atmospheric Electric Field near Elbrus in Fair Weather

    Science.gov (United States)

    Boldyreff, Anton; Adzhiev, Anatoly; Boldyreva, Ksenia; Knyazeva, Zalina; Kudrinskaya, Tatiana; Kupovykh, Gennady; Pestova, Olesya; Pestov, Dmitry; Redin, Alexander

    2014-05-01

    Atmospheric Electric field variations are an appropriate indicator of local weather phenomena electrification and global electric circuit processes. The temporal variations of electric field based on experimental data, measured at Baksan gorge and high-mountains stations near Elbrus in the period of June 2012 - September 2013. The experimental stations are located in the natural preserve zone, characterized by low aerosol emissions and low quantity of ionizing radiation sources. Such perfect conditions allow to identify the diurnal variations of the electric field in fair weather, caused by unitary variation of the potential gradient. The station near Kyzburun village is situated 40 km on the west from Nalchik city at 600 m above sea level (43º40'N, 43º27'E). The alpine stations "Peak Cheget" and "Peak Terskol" are situated at 3040 m and 3003 m above sea level respectively (43º16'N, 42º30'E). The distance between mountain stations is about 3 km. The Kyzburun station is located 70 km on the east along the Baksan canyon. The EFM 550 Vaisala devices were used for uninterrupted electric field registration at three experimental stations. Measuring sensors were installed on the buildings' roofs at 3 m height. The Vaisala weather stations were applied for automatic 10-minutes registrations of the meteorological data on each stations. Meteorological parameters have been also measured using traditional methods simultaneously. The electric field diurnal variation during summer is characterized by significant evening maximum (16-19) UT and morning minimum (09-12) UT for all stations. The extra morning maximum at (05-07) UT was observed as a peculiarity of diurnal electric field data, received at Kyzburun, during summer and winter seasons. The correlation between diurnal variation of data, received at high-mountains stations and Carnegie curve, is rather high. Correlation between electric field, measured at high-altitude stations (Peak Cheget, Peak Terskol) and plain

  2. Silicon photonic integrated circuits with electrically programmable non-volatile memory functions.

    Science.gov (United States)

    Song, J-F; Lim, A E-J; Luo, X-S; Fang, Q; Li, C; Jia, L X; Tu, X-G; Huang, Y; Zhou, H-F; Liow, T-Y; Lo, G-Q

    2016-09-19

    Conventional silicon photonic integrated circuits do not normally possess memory functions, which require on-chip power in order to maintain circuit states in tuned or field-configured switching routes. In this context, we present an electrically programmable add/drop microring resonator with a wavelength shift of 426 pm between the ON/OFF states. Electrical pulses are used to control the choice of the state. Our experimental results show a wavelength shift of 2.8 pm/ms and a light intensity variation of ~0.12 dB/ms for a fixed wavelength in the OFF state. Theoretically, our device can accommodate up to 65 states of multi-level memory functions. Such memory functions can be integrated into wavelength division mutiplexing (WDM) filters and applied to optical routers and computing architectures fulfilling large data downloading demands.

  3. 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.

  4. 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.

  5. Electrical circuit analysis and technical english: articulation in a project-based learning environment

    OpenAIRE

    Oliveira, José Manuel; Branco, Denise; Oliveira, João Pedro Estima de

    2010-01-01

    This paper describes the integration of Electrical Circuit Analysis and Technical English in the same curricular module, in the context of a Project Based Learning (PBL) environment. The idea consists in taking advantage of the PBL setting to provide a context for the learning of the two different subjects in an articulated manner. The results of the evaluation of the first iteration of this experiment will also be discussed.

  6. 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;

    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...... 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....

  7. 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.)

  8. Soft Anisotropic Conductors as Electric Vias for Ga-Based Liquid Metal Circuits.

    Science.gov (United States)

    Lu, Tong; Wissman, James; Ruthika; Majidi, Carmel

    2015-12-09

    We introduce a method for sealing liquid metal (LM) circuits with soft anisotropic conductors that prevent leaking, while simultaneously allowing for electrical contact with skin and surface mounted electronics. These films are composed of polydimethylsiloxane (PDMS) embedded with vertically aligned columns of ferromagnetic Ag-Ni microparticles. The microparticles are magnetically aligned and support electrical conductivity only through the thickness (z-axis) of the elastomer film. Measurements on 10-40% (by wt) composites show moderate volumetric resistivity (as low as ρ = 0.03 Ω/m) through the thickness and no conductivity between adjacent traces. Functionality is demonstrated with several illustrative applications related to tactile sensing and electronics hardware integration.

  9. Discharge processes and an electrical model of atmospheric pressure plasma jets in argon

    Science.gov (United States)

    Fang, Zhi; Shao, Tao; Yang, Jing; Zhang, Cheng

    2016-01-01

    In this paper, an atmospheric pressure plasma discharge in argon was generated using a needle-to-ring electrode configuration driven by a sinusoidal excitation voltage. The electric discharge processes and discharge characteristics were investigated by inspecting the voltage-current waveforms, Lissajous curves and lighting emission images. The change in discharge mode with applied voltage amplitude was studied and characterised, and three modes of corona discharge, dielectric barrier discharge (DBD) and jet discharge were identified, which appeared in turn with increasing applied voltage and can be distinguished clearly from the measured voltage-current waveforms, light-emission images and the changing gradient of discharge power with applied voltage. Based on the experimental results and discharge mechanism analysis, an equivalent electrical model and the corresponding equivalent circuit for characterising the whole discharge processes accurately was proposed, and the three discharge stages were characterised separately. A voltage-controlled current source (VCCS) associated with a resistance and a capacitance were used to represent the DBD stage, and the plasma plume and corona discharge were modelled by a variable capacitor in series with a variable resistor. Other factors that can influence the discharge, such as lead and stray capacitance values of the circuit, were also considered in the proposed model. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.

  10. 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.

  11. 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.

  12. The Effects on Students’ Conceptual Understanding of Electric Circuits of Introducing Virtual Manipulatives Within a Physical Manipulatives-Oriented Curriculum

    NARCIS (Netherlands)

    Zacharia, Zacharias C.; Jong, de Ton

    2014-01-01

    This study investigates whether Virtual Manipulatives (VM) within a Physical Manipulatives (PM)-oriented curriculum affect conceptual understanding of electric circuits and related experimentation processes. A pre–post comparison study randomly assigned 194 undergraduates in an introductory physics

  13. 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.

  14. 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.

  15. 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

  16. Carbon Nanotube Nanocomposites with Highly Enhanced Strength and Conductivity for Flexible Electric Circuits.

    Science.gov (United States)

    Hwang, Ji-Young; Kim, Han-Sem; Kim, Jeong Hun; Shin, Ueon Sang; Lee, Sang-Hoon

    2015-07-21

    Carbon nanotubes (CNTs) have an important role in nanotechnology due to their unique properties, retaining the inherent material flexibility, superior strength, and electrical conductivity, unless the bottleneck of CNTs persists and the aggregated structure is overcome. Here, we report on the highly enhanced mechanical and electrical properties of the CNT-chitosan nanocomposites through homogeneous dispersion of CNTs into chitosan solution using a high-pressure homogenizer. The optimal condition is a 50% (w/w) chitosan-CNT film, providing about 7 nm thickness of homogeneous chitosan layer on CNTs, a good tensile strength of 51 MPa, high electrical conductivity under 16 Ω/sq, and a stable bending and folding performance. This CNT-chitosan nanocomposite with highly enhanced properties is an amenable material to fabricate structures of various shapes such as films, sensors, and circuits and also enables a simple and cost-effective approach to improve the performance of a device that presents the first flexible and soft electric circuits yet reported using only CNT-chitosan as the conductor.

  17. 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

  18. Complicated Electric Circuit P-T Calculus Model Based on VHDL%基于VHDL的复杂电路的P-T算法模型

    Institute of Scientific and Technical Information of China (English)

    刘丹非; 李曼义; 郭金怀

    2003-01-01

    When we design electric circuit with the hardware describe language VHDL,if the control of the electriccircuit is more than to calculate,we can design electric circuit as a controller which is based on multiplexer and is di-vided into the space part and the time part. Electric circuit is synthesized and form CPLD or FPGA circuit by adjustingthe P- T arithmetic model. We explain this method by designing the controller of CPU as a example.

  19. Electrical and optical characterization of an atmospheric pressure, uniform, large-area processing, dielectric barrier discharge

    Science.gov (United States)

    Zeniou, A.; Puač, N.; Škoro, N.; Selaković, N.; Dimitrakellis, P.; Gogolides, E.; Petrović, Z. Lj

    2017-04-01

    A printed-circuit-board (PCB) based atmospheric pressure dielectric barrier discharge (DBD) capable of uniform processing over a large area was constructed consisting of two parallel plates. The first perforated plate is comprised of four layers: a RF powered metal layer, a polymeric dielectric layer, a floating metal grid and another dielectric layer. The second, grounded, plate was fluorine doped tin oxide (FTO) glass plate with surface of 100  ×  100 mm2 and thickness of 2 mm. The PCB based atmospheric pressure DBD was characterized by (a) measuring electrical characteristics of the device using derivative I–V probes, (b) ICCD imaging and (c) optical emission spectroscopy (OES). Optical and electrical characteristics, as well as plasma uniformity were measured by changing He flow rate and input power, while keeping the gap between the PCB and the FTO glass plate ground electrode constant at 2 mm. The plasma uniformity strongly depends on the applied power and on the flow rate of the buffer gas. When increasing the flow rate, the intensity of the nitrogen-dominated emission drops, while emission of helium and oxygen lines increases. The source allows low temperature, uniform plasma operation over a wide area of 100  ×  100 mm2, which could be essential for numerous applications. Examples of etching rate and hydrophilization are demonstrated.

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

    Energy Technology Data Exchange (ETDEWEB)

    Leite, D. M. G., E-mail: dmgleite@fc.unesp.br [UNIFEI—Universidade Federal de Itajubá, Av. BPS, 1303, 37500-903 Itajubá, MG (Brazil); Batagin-Neto, A.; Nunes-Neto, O. [UNESP—Univ Estadual Paulista, POSMAT—Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, 17033-360 Bauru, SP (Brazil); Gómez, J. A. [Departamento de Física, FFCLRP-USP, Av. Bandeirantes 3900, 14040-901 Ribeirão Preto, SP (Brazil); Graeff, C. F. O. [UNESP—Univ Estadual Paulista, POSMAT—Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, 17033-360 Bauru, SP (Brazil); DF-FC, UNESP—Univ Estadual Paulista, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, 17033-360 Bauru, SP (Brazil)

    2014-01-21

    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 Alq{sub 3} 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.

  1. 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.

  2. 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...

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

    Science.gov (United States)

    Borra, J. P.

    2008-12-01

    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).

  4. Numerical Electric Field Analysis of Power Status Sensor Observing Power Distribution System Taking into Account Voltage Divider Measurement Circuit

    Science.gov (United States)

    Kubo, Takuro; Furukawa, Tatsuya; Itoh, Hideaki; Fukumoto, Hisao; Wakuya, Hiroshi; Ohchi, Masashi

    We have proposed and preproducted the voltage-current waveform sensor of resin molded type for measuring the power factor and harmonics in power distribution systems. We have executed numerical electromagnetic analyses using the finite element method to estimate the characteristics and behaviours of the sensor. Although the magnetic field analyses for the current sensor have involved the measurement circuit, the electric field analyses have not included the measurement circuit for measuring voltage waveforms of power lines. In this paper, we describe the electric field analyses with the measurement circuit and prove the insulating strength of the proposed sensor permissible to the use in 22kV power distribution systems.

  5. 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.

  6. Novel passive element circuits for microdosimetry of nanosecond pulsed electric fields.

    Science.gov (United States)

    Merla, C; Denzi, A; Paffi, A; Casciola, M; d'Inzeo, G; Apollonio, F; Liberti, M

    2012-08-01

    Microdosimetric models for biological cells have assumed increasing significance in the development of nanosecond pulsed electric field technology for medical applications. In this paper, novel passive element circuits, able to take into account the dielectric dispersion of the cell, are provided. The circuital analyses are performed on a set of input pulses classified in accordance with the current literature. Accurate data in terms of transmembrane potential are obtained in both time and frequency domains for different cell models. In addition, a sensitivity study of the transfer function for the cell geometrical and dielectric parameters has been carried out. This analysis offers a new, simple, and efficient tool to characterize the nsPEFs' action at the cellular level.

  7. Fully integrated quantum photonic circuit with an electrically driven light source

    Science.gov (United States)

    Khasminskaya, Svetlana; Pyatkov, Felix; Słowik, Karolina; Ferrari, Simone; Kahl, Oliver; Kovalyuk, Vadim; Rath, Patrik; Vetter, Andreas; Hennrich, Frank; Kappes, Manfred M.; Gol'Tsman, G.; Korneev, A.; Rockstuhl, Carsten; Krupke, Ralph; Pernice, Wolfram H. P.

    2016-11-01

    Photonic quantum technologies allow quantum phenomena to be exploited in applications such as quantum cryptography, quantum simulation and quantum computation. A key requirement for practical devices is the scalable integration of single-photon sources, detectors and linear optical elements on a common platform. Nanophotonic circuits enable the realization of complex linear optical systems, while non-classical light can be measured with waveguide-integrated detectors. However, reproducible single-photon sources with high brightness and compatibility with photonic devices remain elusive for fully integrated systems. Here, we report the observation of antibunching in the light emitted from an electrically driven carbon nanotube embedded within a photonic quantum circuit. Non-classical light generated on chip is recorded under cryogenic conditions with waveguide-integrated superconducting single-photon detectors, without requiring optical filtering. Because exclusively scalable fabrication and deposition methods are used, our results establish carbon nanotubes as promising nanoscale single-photon emitters for hybrid quantum photonic devices.

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

    Science.gov (United States)

    Liu, Weiqun; Badel, Adrien; Formosa, Fabien; Wu, Yipeng; Agbossou, Amen

    2013-12-01

    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.

  9. 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.

  10. 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.

  11. 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.

  12. Electric Currents and Fields in Middle and Low Atmosphere in Fair-Weather Regions due to Distant Thunderstorms

    Science.gov (United States)

    Velinov, Peter; Velinov, Peter; Tonev, Peter

    The electric currents created by the thunderstorms and the electrified shower clouds over the Earth flow into the global atmospheric electric circuit and are responsible for the formation in fair-weather regions of ionosphere-ground current of about 2 pA per square meter, as well as for the related fair-weather electric field of the order of 100 V/m at sea level. The link of the diurnal variations of the fair-weather electric field with the global thunderstorm activity has been widely studied with connection to the Wilson's hypothesis. To confirm this hypothesis directly, also the fair-weather electric field response to a strong single lightning discharge has being examined. Here we study theoretically the variations of the electric currents and fields in fair-weather regions at different altitudes of the lower and middle atmosphere, which are provoked by distant lightning discharges. The electric field variations can play an important role at higher altitudes (in the upper troposphere and above), where they are much larger and possibly influence the physical and chemical processes. For our goals we realize a globalscale model of the electric fields and currents generated by a lightning discharge, which is based on the Maxwell's equations. The fair-weather electric characteristics are studied by our model depending on the lightning parameters, location and distance. We also examine how variations of the conductivity in the strato/mesosphere due to changes of solar and geomagnetic activity affect the characteristics studied. Another question discussed is whether and how the mesospheric electric response to a remote lightning discharge is influenced by the conductivity anisotropy above 70 km and by the geomagnetic field geometry. The variations of the fairweather electric fields due to a distant lightning at tropospheric heights are also studied with respect to their presumable role in the cloud physics.

  13. Highly stretchable electric circuits from a composite material of silver nanoparticles and elastomeric fibres.

    Science.gov (United States)

    Park, Minwoo; Im, Jungkyun; Shin, Minkwan; Min, Yuho; Park, Jaeyoon; Cho, Heesook; Park, Soojin; Shim, Mun-Bo; Jeon, Sanghun; Chung, Dae-Young; Bae, Jihyun; Park, Jongjin; Jeong, Unyong; Kim, Kinam

    2012-12-01

    Conductive electrodes and electric circuits that can remain active and electrically stable under large mechanical deformations are highly desirable for applications such as flexible displays, field-effect transistors, energy-related devices, smart clothing and actuators. However, high conductivity and stretchability seem to be mutually exclusive parameters. The most promising solution to this problem has been to use one-dimensional nanostructures such as carbon nanotubes and metal nanowires coated on a stretchable fabric, metal stripes with a wavy geometry, composite elastomers embedding conductive fillers and interpenetrating networks of a liquid metal and rubber. At present, the conductivity values at large strains remain too low to satisfy requirements for practical applications. Moreover, the ability to make arbitrary patterns over large areas is also desirable. Here, we introduce a conductive composite mat of silver nanoparticles and rubber fibres that allows the formation of highly stretchable circuits through a fabrication process that is compatible with any substrate and scalable for large-area applications. A silver nanoparticle precursor is absorbed in electrospun poly (styrene-block-butadiene-block-styrene) (SBS) rubber fibres and then converted into silver nanoparticles directly in the fibre mat. Percolation of the silver nanoparticles inside the fibres leads to a high bulk conductivity, which is preserved at large deformations (σ ≈ 2,200 S cm(-1) at 100% strain for a 150-µm-thick mat). We design electric circuits directly on the electrospun fibre mat by nozzle printing, inkjet printing and spray printing of the precursor solution and fabricate a highly stretchable antenna, a strain sensor and a highly stretchable light-emitting diode as examples of applications.

  14. Highly stretchable electric circuits from a composite material of silver nanoparticles and elastomeric fibres

    Science.gov (United States)

    Park, Minwoo; Im, Jungkyun; Shin, Minkwan; Min, Yuho; Park, Jaeyoon; Cho, Heesook; Park, Soojin; Shim, Mun-Bo; Jeon, Sanghun; Chung, Dae-Young; Bae, Jihyun; Park, Jongjin; Jeong, Unyong; Kim, Kinam

    2012-12-01

    Conductive electrodes and electric circuits that can remain active and electrically stable under large mechanical deformations are highly desirable for applications such as flexible displays, field-effect transistors, energy-related devices, smart clothing and actuators. However, high conductivity and stretchability seem to be mutually exclusive parameters. The most promising solution to this problem has been to use one-dimensional nanostructures such as carbon nanotubes and metal nanowires coated on a stretchable fabric, metal stripes with a wavy geometry, composite elastomers embedding conductive fillers and interpenetrating networks of a liquid metal and rubber. At present, the conductivity values at large strains remain too low to satisfy requirements for practical applications. Moreover, the ability to make arbitrary patterns over large areas is also desirable. Here, we introduce a conductive composite mat of silver nanoparticles and rubber fibres that allows the formation of highly stretchable circuits through a fabrication process that is compatible with any substrate and scalable for large-area applications. A silver nanoparticle precursor is absorbed in electrospun poly (styrene-block-butadiene-block-styrene) (SBS) rubber fibres and then converted into silver nanoparticles directly in the fibre mat. Percolation of the silver nanoparticles inside the fibres leads to a high bulk conductivity, which is preserved at large deformations (σ ~ 2,200 S cm-1 at 100% strain for a 150-µm-thick mat). We design electric circuits directly on the electrospun fibre mat by nozzle printing, inkjet printing and spray printing of the precursor solution and fabricate a highly stretchable antenna, a strain sensor and a highly stretchable light-emitting diode as examples of applications.

  15. A test technique for measuring lightning-induced voltages on aircraft electrical circuits

    Science.gov (United States)

    Walko, L. C.

    1974-01-01

    The development of a test technique used for the measurement of lightning-induced voltages in the electrical circuits of a complete aircraft is described. The resultant technique utilizes a portable device known as a transient analyzer capable of generating unidirectional current impulses similar to lightning current surges, but at a lower current level. A linear relationship between the magnitude of lightning current and the magnitude of induced voltage permitted the scaling up of measured induced values to full threat levels. The test technique was found to be practical when used on a complete aircraft.

  16. Effect of voltage shape of electrical power supply on radiation and density of a cold atmospheric argon plasma jet

    Directory of Open Access Journals (Sweden)

    F Sohbatzadeh

    2017-02-01

    Full Text Available In this work, we investigated generating argon cold plasma jet at atmospheric pressure based on dielectric barrier discharge configuration using three electrical power supplies of sinusoidal, pulsed and saw tooth high voltage shapes at 8 KHZ. At first; we describe the electronic circuit features for generating high voltage (HV wave forms including saw tooth, sinusoidal and pulsed forms. Then, we consider the effect of voltage shape on the electrical breakdown. Relative concentrations of chemical reactive species such as Oxygen, atomic Nitrogen and OH were measured using optical emission spectroscopy. Using a simple numerical model, we showed a HV with less rise time increases electron density, therefore a cold plasma jet can be produced with a minimal consumption electrical power

  17. Note: Printed circuit board based electrically triggered compact rail gap switch.

    Science.gov (United States)

    Saxena, A K; Kaushik, T C; Goswami, M P; Gupta, Satish C

    2010-05-01

    An electrically triggered rail gap switch has been designed over a commercially available copper clad fiberglass sheet commonly used in making printed circuit boards for applications requiring compact design and direct integration to parallel plate transmission lines. Switch performance has been investigated in terms of its inductance, jitter, and gap closing time. With an electrode separation of 9.0 mm, it has been found to have an inductance of 6 nH, gap closing time of 5 ns, and jitter of about 4-10 ns measured at 95% of self-breakdown voltage. An application of this switch has been demonstrated as an electrically exploding foil accelerator developed over the same board and velocities up to 1.6 km/s have been achieved on Kapton flyers with diameter of 3.0 mm and thickness of 125 microm using a compact 1 microF capacitor bank.

  18. A computational model for epidural electrical stimulation of spinal sensorimotor circuits.

    Science.gov (United States)

    Capogrosso, Marco; Wenger, Nikolaus; Raspopovic, Stanisa; Musienko, Pavel; Beauparlant, Janine; Bassi Luciani, Lorenzo; Courtine, Grégoire; Micera, Silvestro

    2013-12-04

    Epidural electrical stimulation (EES) of lumbosacral segments can restore a range of movements after spinal cord injury. However, the mechanisms and neural structures through which EES facilitates movement execution remain unclear. Here, we designed a computational model and performed in vivo experiments to investigate the type of fibers, neurons, and circuits recruited in response to EES. We first developed a realistic finite element computer model of rat lumbosacral segments to identify the currents generated by EES. To evaluate the impact of these currents on sensorimotor circuits, we coupled this model with an anatomically realistic axon-cable model of motoneurons, interneurons, and myelinated afferent fibers for antagonistic ankle muscles. Comparisons between computer simulations and experiments revealed the ability of the model to predict EES-evoked motor responses over multiple intensities and locations. Analysis of the recruited neural structures revealed the lack of direct influence of EES on motoneurons and interneurons. Simulations and pharmacological experiments demonstrated that EES engages spinal circuits trans-synaptically through the recruitment of myelinated afferent fibers. The model also predicted the capacity of spatially distinct EES to modulate side-specific limb movements and, to a lesser extent, extension versus flexion. These predictions were confirmed during standing and walking enabled by EES in spinal rats. These combined results provide a mechanistic framework for the design of spinal neuroprosthetic systems to improve standing and walking after neurological disorders.

  19. 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.

  20. 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

  1. A pulse-compression-ring circuit for high-efficiency electric propulsion.

    Science.gov (United States)

    Owens, Thomas L

    2008-03-01

    A highly efficient, highly reliable pulsed-power system has been developed for use in high power, repetitively pulsed inductive plasma thrusters. The pulsed inductive thruster ejects plasma propellant at a high velocity using a Lorentz force developed through inductive coupling to the plasma. Having greatly increased propellant-utilization efficiency compared to chemical rockets, this type of electric propulsion system may one day propel spacecraft on long-duration deep-space missions. High system reliability and electrical efficiency are extremely important for these extended missions. In the prototype pulsed-power system described here, exceptional reliability is achieved using a pulse-compression circuit driven by both active solid-state switching and passive magnetic switching. High efficiency is achieved using a novel ring architecture that recovers unused energy in a pulse-compression system with minimal circuit loss after each impulse. As an added benefit, voltage reversal is eliminated in the ring topology, resulting in long lifetimes for energy-storage capacitors. System tests were performed using an adjustable inductive load at a voltage level of 3.3 kV, a peak current of 20 kA, and a current switching rate of 15 kA/micros.

  2. A perturbation of DC electric field caused by light ion adhesion to aerosols during the growth in seismic-related atmospheric radioactivity

    Directory of Open Access Journals (Sweden)

    V. M. Sorokin

    2007-01-01

    Full Text Available The influence of variations in conductivity and external electric current variations in the lower atmosphere on DC electric field over a seismic region is investigated. The external current is formed with the occurrence of convective upward transport of charged aerosols and their gravitational sedimentation in the atmosphere. This effect is related with the occurrence of ionization source due to seismic-related emanation of radon and other radioactive elements into the lower atmosphere. An increase in atmosphere radioactivity level results in the appearance of additional sources of ionization, and altitude dependence of the ion formation rate is calculated. Ionization source varies the atmospheric conductivity and the external current through appearance of ions with equilibrium number density and their adhesion to aerosols. We have calculated the perturbation of conductivity and external electric current as a function of altitude. Variation of conductivity and external current in the lower atmosphere leads to a perturbation of electric current which flows in the global atmosphere-ionosphere circuit. Finally, perturbations of DC electric field both on the Earth's surface and in the ionosphere are estimated.

  3. Cold atmospheric plasma jet in an axial DC electric field

    Science.gov (United States)

    Lin, Li; Keidar, Michael

    2016-08-01

    Cold atmospheric plasma (CAP) jet is currently intensively investigated as a tool for new and potentially transformative cancer treatment modality. However, there are still many unknowns about the jet behavior that requires attention. In this paper, a helium CAP jet is tested in an electrostatic field generated by a copper ring. Using Rayleigh microwave scattering method, some delays of the electron density peaks for different ring potentials are observed. Meanwhile, a similar phenomenon associated with the bullet velocity is found. Chemical species distribution along the jet is analyzed based on the jet optical emission spectra. The spectra indicate that a lower ring potential, i.e., lower DC background electric field, can increase the amount of excited N2, N2+, He, and O in the region before the ring, but can decrease the amount of excited NO and HO almost along the entire jet. Combining all the results above, we discovered that an extra DC potential mainly affects the temporal plasma jet properties. Also, it is possible to manipulate the chemical compositions of the jet using a ring with certain electric potentials.

  4. 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

  5. Three-dimensional Model Analysis of Electric Field Excited by Multi-circuit Intersecting Overhead Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    XIAO Dongping; LEI Hui; ZHANG Zhanlong; HE Wei

    2013-01-01

    This work is carried out to predict the special distribution of electric field induced by multi-circuit intersecting overhead high-voltage (HV) transmission lines (TLs) within a large range without any expensive and time-consuming computation.The two main parts of the presented methodology are 1) setting up a three-dimensional (3D) model to calculate the electric field based on combining catenary equations with charge simulation method and 2) calculating the hybrid electric field excited by multi-circuit intersecting TLs using coordinate transformation and superposition technique.Examples of different TLs configurations,including a 220 kV single-circuit horizontally configured TLs,a 500 kV single-circuit triangularly configured TLs and a combination of the 220 kV TLs and the 550 kV TLs,are illustrated to verify the validity of this methodology.A more complicatal configurations,including a 500 kV double-circuit TLs and two 220kV single-circuit horizontally configured TLs,are also calculated.Conclusions were drawn from the simulation:1) The presented 3D model outperforms 2D models in describing the electric field distribution generated by practical HV TLs with sag and span.2) Coordinate transformation and superposition technique considerably simplify the electric field computation for multi-circuit TLs configurations,which makes it possible to deal with complex engineering problems.3) The electric field in the area covered by multiple intersecting overhead TLs is distorted and the hybrid electric field strength in some partial region increases so sharply that it might exceed the admissible value.4) The configuration parameters of the TLs and the spatial configuration of multi-circuit TLs,for instance,the height of TLs,the length of span and the intersection angle of multiple circuits,influence the strength and the distribution of hybrid electric field.The influence regularities summarized in this paper can be referred by future TL designs to meet the electromagnetic

  6. 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

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

    Science.gov (United States)

    Shiffman, C A

    2013-05-01

    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.

  8. Electrical circuit models for performance modeling of Lithium-Sulfur batteries

    DEFF Research Database (Denmark)

    Knap, Vaclav; Stroe, Daniel Ioan; Teodorescu, Remus;

    2015-01-01

    of the industry are met yet. Therefore, researchers focus on alternative battery chemistries as Lithium-Sulfur (Li-S), which have a huge potential due to their high theoretical specific capacity (approx. 1675 Ah/kg) and theoretical energy density of almost 2600 Wh/kg. To analyze the suitability of this new......Energy storage technologies such as Lithium-ion (Li-ion) batteries are widely used in the present effort to move towards more ecological solutions in sectors like transportation or renewable-energy integration. However, today's Li-ion batteries are reaching their limits and not all demands...... emerging technology for various applications, there is a need for Li-S battery performance model; however, developing such models represents a challenging task due to batteries' complex ongoing chemical reactions. Therefore, the literature review was performed to summarize electrical circuit models (ECMs...

  9. An improved switching control law for the optimized synchronous electric charge extraction circuit

    Science.gov (United States)

    Liu, Weiqun; Badel, Adrien; Formosa, Fabien; Liu, Congzhi; Hu, Guangdi

    2015-12-01

    Nonlinear switching interface circuits are considered as an efficient way to improve the performance of vibration energy harvesters. Among the various approaches, OSECE (Optimized Synchronous Electric Charge Extraction) exhibits satisfying properties: simple switching strategy, good performance in low coupling cases and low load dependency. However, the overdamping induced by the voltage inversion at maximal points leads to performance degeneration in high coupling cases. This paper presents an improved switching control law for the OSECE technique. The new OSECE_PT (OSECE with switching Phase Tuning) technique presented here is to let the switches act ahead or after the maximal point with a phase tuning. Theoretical analysis and numerical simulations show that the OSECE_PT technique can improve the power performance effectively and preserves desired load independence properties.

  10. Rocket measurements within a polar cap arc - Plasma, particle, and electric circuit parameters

    Science.gov (United States)

    Weber, E. J.; Ballenthin, J. O.; Basu, S.; Carlson, H. C.; Hardy, D. A.; Maynard, N. C.; Kelley, M. C.; Fleischman, J. R.; Pfaff, R. F.

    1989-01-01

    Results are presented from the Polar Ionospheric Irregularities Experiment (PIIE), conducted from Sondrestrom, Greenland, on March 15, 1985, designed for an investigation of processes which lead to the generation of small-scale (less than 1 km) ionospheric irregularities within polar-cap F-layer auroras. An instrumented rocket was launched into a polar cap F layer aurora to measure energetic electron flux, plasma, and electric circuit parameters of a sun-aligned arc, coordinated with simultaneous measurements from the Sondrestrom incoherent scatter radar and the AFGL Airborne Ionospheric Observatory. Results indicated the existence of two different generation mechanisms on the dawnside and duskside of the arc. On the duskside, parameters are suggestive of an interchange process, while on the dawnside, fluctuation parameters are consistent with a velocity shear instability.

  11. 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.

  12. 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...

  13. Nonlinear Electrical Circuit Oscillator Control Based on Backstepping Method: A Genetic Algorithm Approach

    Directory of Open Access Journals (Sweden)

    Mahsa Khoeiniha

    2012-01-01

    Full Text Available This paper investigated study of dynamics of nonlinear electrical circuit by means of modern nonlinear techniques and the control of a class of chaotic system by using backstepping method based on Lyapunov function. The behavior of such nonlinear system when they are under the influence of external sinusoidal disturbances with unknown amplitudes has been considered. The objective is to analyze the performance of this system at different amplitudes of disturbances. We illustrate the proposed approach for controlling duffing oscillator problem to stabilize this system at the equilibrium point. Also Genetic Algorithm method (GA for computing the parameters of controller has been used. GA can be successfully applied to achieve a better controller. Simulation results have shown the effectiveness of the proposed method.

  14. 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.

  15. 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.

  16. Double negative elastic metamaterial design through electrical-mechanical circuit analogies.

    Science.gov (United States)

    Pope, Simon A

    2013-07-01

    Previous studies into solid elastic metamaterials which have a simultaneously negative effective bulk modulus and density have proposed designs for materials with relatively narrow bandwidths, because of the reliance on resonators to provide the dispersive material properties. Some of the proposed novel applications for metamaterials, such as invisibility cloaks and sub-wavelength lenses, generally require materials with inherently larger bandwidths for practical exploitation. In this paper, a well-known electromagnetic metamaterial design is used together with the electrical-mechanical circuit analogies to propose a simultaneously double negative elastic metamaterial design which does not suffer from the narrow bandwidth constraints of previous designs. An interesting consequence of the proposed design is that it has an effective wavelength which asymptotically goes to infinity with frequency.

  17. Using the Zero-Resistance Spark Circuit on the Wire Cut Electric Discharge Machine to Realize Energy Savings

    Directory of Open Access Journals (Sweden)

    Shao-Hsien Chen

    2014-08-01

    Full Text Available There is an increasing emphasis on the development green manufacturing technologies. To improve processing and energy efficiency of modern Wire Cut Electric Discharge Machines (WEDM, many studies have focused on the design of the device’s discharge circuit. Currently, most such circuits use a resistor to impose current-limitations. When current flows through this resistor, considerable electrical energy converted into heat. The generated heat increases the temperature in the discharge circuit, which negatively impacts processing and energy efficiency, even though the temperature rise could be controlled by arranging cooling devices around the discharge circuit. This study seeks to produce an improved discharge circuit for use in WEDMs. We use DC-DC and electronic voltage regulation technology to convert the energy originally dissipated in the resistor directly into the energy for use in machining. The Zero-Resistance Spark Circuit is the critical design to realize the energy saving effect. Experimental results indicate energy savings of 10 to 15%.

  18. Highly conductive and ultrastretchable electric circuits from covered yarns and silver nanowires.

    Science.gov (United States)

    Cheng, Yin; Wang, Ranran; Sun, Jing; Gao, Lian

    2015-04-28

    Stretchable electronics, as a promising research frontier, has achieved progress in a variety of sophisticated applications. The realization of stretchable electronics frequently involves the demand for a stretchable conductor as an electrical circuit. However, it still remains a challenge to fabricate high-performance (working strain exceeding 200%) stretchable conductors. Here, we present for the first time a facile, cost-effective, and scalable method for manufacturing ultrastretchable composite fibers with a "twining spring" configuration: cotton fibers twining spirally around a polyurethane fiber. The composite fiber possesses a high conductivity up to 4018 S/cm, which remains as high as 688 S/cm at 500% tensile strain. In addition, the conductivity of the composite fiber (initial conductivity of 4018 S/cm) remains perfectly stable after 1000 bending events and levels off at 183 S/cm after 1000 cyclic stretching events of 200% strain. Stretchable LED arrays are integrated efficiently utilizing the composite fibers as a stretchable electric wiring system, demonstrating the potential applications in large-area stretchable electronics. The biocompatibility of the composite fiber is verified, opening up its prospects in the field of implantable devices. Our fabrication strategy is also versatile for the preparation of other specially functionalized composite fibers with superb stretchability.

  19. To Compare the Effects of Computer Based Learning and the Laboratory Based Learning on Students' Achievement Regarding Electric Circuits

    Science.gov (United States)

    Bayrak, Bekir; Kanli, Uygar; Ingec, Sebnem Kandil

    2007-01-01

    In this study, the research problem was: "Is the computer based physics instruction as effective as laboratory intensive physics instruction with regards to academic success on electric circuits 9th grade students?" For this research of experimental quality the design of pre-test and post-test are applied with an experiment and a control…

  20. A Comparison of Students' Conceptual Understanding of Electric Circuits in Simulation Only and Simulation-Laboratory Contexts

    Science.gov (United States)

    Jaakkola, Tomi; Nurmi, Sami; Veermans, Koen

    2011-01-01

    The aim of this experimental study was to compare learning outcomes of students using a simulation alone (simulation environment) with outcomes of those using a simulation in parallel with real circuits (combination environment) in the domain of electricity, and to explore how learning outcomes in these environments are mediated by implicit (only…

  1. Comparing and Combining Real and Virtual Experimentation: An Effort to Enhance Students' Conceptual Understanding of Electric Circuits

    Science.gov (United States)

    Zacharia, Z. C.

    2007-01-01

    The purpose of this study was to investigate value of combining Real Experimentation (RE) with Virtual Experimentation (VE) with respect to changes in students' conceptual understanding of electric circuits. To achieve this, a pre-post comparison study design was used that involved 88 undergraduate students. The participants were randomly assigned…

  2. A Case Study Analysing the Process of Analogy-Based Learning in a Teaching Unit about Simple Electric Circuits

    Science.gov (United States)

    Paatz, Roland; Ryder, James; Schwedes, Hannelore; Scott, Philip

    2004-01-01

    The purpose of this case study is to analyse the learning processes of a 16-year-old student as she learns about simple electric circuits in response to an analogy-based teaching sequence. Analogical thinking processes are modelled by a sequence of four steps according to Gentner's structure mapping theory (activate base domain, postulate local…

  3. Conceptions of Pupils of the Primary on the Topic of an Electric Circuit in Three Countries (Canada, France and Morocco)

    Science.gov (United States)

    Métioui, Abdeljalil; MacWillie, Mireille Baulu; Trudel, Louis

    2016-01-01

    Qualitative research conducted with 237 pupils from Canada, France, and Morocco, between 10 and 12 years of age, on the setting and functioning of simple electric circuits, demonstrates that similar explanatory systems of the students. For this, we had given them a paper and pencil questionnaire of a sixty minutes duration. The first question was…

  4. Using a Conflict Map as an Instructional Tool To Change Student Conceptions in Simple Series Electric-Circuits.

    Science.gov (United States)

    Tsai, Chin-Chung

    2003-01-01

    Examines the effects of using a conflict map on 8th grade students' conceptual change and ideational networks about simple series electric circuits. Analyzes student interview data through a flow map method. Shows that the use of conflict maps could help students construct greater, richer, and more integrated ideational networks about electric…

  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 B. M.; Salvador, Andreia; Costa, Maria Margarida R. R.

    2014-01-01

    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…

  6. The Effects on Students' Conceptual Understanding of Electric Circuits of Introducing Virtual Manipulatives within a Physical Manipulatives-Oriented Curriculum

    Science.gov (United States)

    Zacharia, Zacharias C.; de Jong, Ton

    2014-01-01

    This study investigates whether Virtual Manipulatives (VM) within a Physical Manipulatives (PM)-oriented curriculum affect conceptual understanding of electric circuits and related experimentation processes. A pre-post comparison study randomly assigned 194 undergraduates in an introductory physics course to one of five conditions: three…

  7. The Confidence-Accuracy Relationship in Diagnostic Assessment: The Case of the Potential Difference in Parallel Electric Circuits

    Science.gov (United States)

    Saglam, Murat

    2015-01-01

    This study explored the relationship between accuracy of and confidence in performance of 114 prospective primary school teachers in answering diagnostic questions on potential difference in parallel electric circuits. The participants were required to indicate their confidence in their answers for each question. Bias and calibration indices were…

  8. 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…

  9. Learning Electrical Circuits: The Effects of the 4C-ID Instructional Approach in the Acquisition and Transfer of Knowledge

    Science.gov (United States)

    Melo, Mário; Miranda, Guilhermina Lobato

    2015-01-01

    This study was designed to investigate the effects of two instructional approaches (4C-ID versus conventional) on learners' knowledge-acquisition and learning transfer of the electrical circuits content in Physics. Participants were 129 9th graders from a secondary school in Lisbon, M = 14.3 years, SD = 0.54. The participants were divided in two…

  10. 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...

  11. Verification and Analysis of Implementing Virtual Electric Devices in Circuit Simulation of Pulsed DC Electrical Devices in the NI MULTISIM 10.1 Environment

    Directory of Open Access Journals (Sweden)

    V. A. Solov'ev

    2015-01-01

    Full Text Available The paper presents the analysis results of the implementation potential and evaluation of the virtual electric devices reliability when conducting circuit simulation of pulsed DC electrical devices in the NI Multisim 10.1environment. It analyses metrological properties of electric measuring devices and sensors of the NI Multisim 10.1environment. To calculate the reliable parameters of periodic non-sinusoidal electrical values based on their physical feasibility the mathematical expressions have been defined.To verify the virtual electric devices a circuit model of the power section of buck DC converter with enabled devices under consideration at its input and output is used as a consumer of pulse current of trapezoidal or triangular form. It is used as an example to show a technique to verify readings of virtual electric measuring devices in the NI Multisim 10.1environment.It is found that when simulating the pulsed DC electric devices to measure average and RMS voltage supply and current consumption values it is advisable to use the probe. Electric device power consumption read from the virtual power meter is equal to its average value, and its displayed power factor is inversely proportional to the input current form factor. To determine the RMS pulsed DC current by ammeter and multi-meter it is necessary to measure current by these devices in DC and AC modes, and then determine the RMS value of measurement results.Virtual electric devices verification has proved the possibility of their application to determine the energy performance of transistor converters for various purposes in the circuit simulation in the NI 10.1 Multisim environment, thus saving time of their designing.

  12. The characteristic electric impedance of the circuits and its influences in the transient currents; A impedancia caracteristica dos circuitos e sua influencia nas correntes transitorias

    Energy Technology Data Exchange (ETDEWEB)

    Kascher, Ronaldo [Tesla Projetos e Consultoria Ltda. (Brazil)

    1997-05-01

    Usually not considered in the calculation of the maximum bearable current or even in the voltage drop throughout the electric circuits, the characteristic electric impedance assumes considerable relevance, especially concerning long distance electric power transmission lines. When dimensioning the protection devices, the consideration of the characteristic electric impedance may drastically reduce the necessary investments. 20 figs., 2 tabs.

  13. 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.

  14. A Practical Circuit-based Model for State of Health Estimation of Li-ion Battery Cells in Electric Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Long

    2011-08-23

    In this thesis the development of the state of health of Li-ion battery cells under possible real-life operating conditions in electric cars has been characterised. Furthermore, a practical circuit-based model for Li-ion cells has been developed that is capable of modelling the cell voltage behaviour under various operating conditions. The Li-ion cell model can be implemented in simulation programs and be directly connected to a model of the rest of the electronic system in electric vehicles. Most existing battery models are impractical for electric vehicle system designers and require extensive background knowledge of electrochemistry to be implemented. Furthermore, many models do not take the effect of regenerative braking into account and are obtained from testing fully charged cells. However, in real-life applications electric vehicles are not always fully charged and utilise regenerative braking to save energy. To obtain a practical circuit model based on real operating conditions and to model the state of health of electric vehicle cells, numerous 18650 size LiFePO4 cells have been tested under possible operating conditions. Capacity fading was chosen as the state of health parameter, and the capacity fading of different cells was compared with the charge processed instead of cycles. Tests have shown that the capacity fading rate is dependent on temperature, charging C-rate, state of charge and depth of discharge. The obtained circuit model is capable of simulating the voltage behaviour under various temperatures and C-rates with a maximum error of 14mV. However, modelling the effect of different temperatures and C-rates increases the complexity of the model. The model is easily adjustable and the choice is given to the electric vehicle system designer to decide which operating conditions to take into account. By combining the test results for the capacity fading and the proposed circuit model, recommendations to optimise the battery lifetime are proposed.

  15. 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

  16. 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

  17. Consistency and advantage of loop regularization method merging with Bjorken-Drell's analogy between Feynman diagrams and electrical circuits

    Science.gov (United States)

    Huang, Da; Wu, Yue-Liang

    2012-07-01

    The consistency of loop regularization (LORE) method is explored in multiloop calculations. A key concept of the LORE method is the introduction of irreducible loop integrals (ILIs) which are evaluated from the Feynman diagrams by adopting the Feynman parametrization and ultraviolet-divergence-preserving (UVDP) parametrization. It is then inevitable for the ILIs to encounter the divergences in the UVDP parameter space due to the generic overlapping divergences in the four-dimensional momentum space. By computing the so-called αβγ integrals arising from two-loop Feynman diagrams, we show how to deal with the divergences in the parameter space with the LORE method. By identifying the divergences in the UVDP parameter space to those in the subdiagrams, we arrive at the Bjorken-Drell analogy between Feynman diagrams and electrical circuits. The UVDP parameters are shown to correspond to the conductance or resistance in the electrical circuits, and the divergence in Feynman diagrams is ascribed to the infinite conductance or zero resistance. In particular, the sets of conditions required to eliminate the overlapping momentum integrals for obtaining the ILIs are found to be associated with the conservations of electric voltages, and the momentum conservations correspond to the conservations of electrical currents, which are known as the Kirchhoff laws in the electrical circuits analogy. As a practical application, we carry out a detailed calculation for one-loop and two-loop Feynman diagrams in the massive scalar ϕ 4 theory, which enables us to obtain the well-known logarithmic running of the coupling constant and the consistent power-law running of the scalar mass at two-loop level. Especially, we present an explicit demonstration on the general procedure of applying the LORE method to the multiloop calculations of Feynman diagrams when merging with the advantage of Bjorken-Drell's circuit analogy.

  18. Analytic Calculation of Radio Emission from Extensive Air Showers subjected to Atmospheric Electric Fields

    CERN Document Server

    Scholten, Olaf; de Vries, Krijn D; van Sloten, Lucas

    2016-01-01

    We have developed a code that semi-analytically calculates the radio footprint (intensity and polarization) of an extensive air shower subject to atmospheric electric fields. This can be used to reconstruct the height dependence of atmospheric electric field from the measured radio footprint. The various parameterizations of the spatial extent of the induced currents are based on the results of Monte-Carlo shower simulations. The calculated radio footprints agree well with microscopic CoREAS simulations.

  19. 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.

  20. 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

  1. Consistency and Advantage of Loop Regularization Method Merging with Bjorken-Drell's Analogy Between Feynman Diagrams and Electrical Circuits

    CERN Document Server

    Huang, Da

    2011-01-01

    The consistency of loop regularization (LORE) method is explored in multiloop calculations. A key concept of the LORE method is the introduction of irreducible loop integrals (ILIs) which are evaluated from the Feynman diagrams by adopting the Feynman parametrization and ultraviolet-divergence-preserving(UVDP) parametrization. It is then inevitable for the ILIs to encounter the divergences in the UVDP-parameter space due to the generic overlapping divergences in the 4-dimensional momentum space. By computing the so-called $\\alpha\\beta\\gamma$ integrals arising from two loop Feynman diagrams, we show how to deal with the divergences in the parameter space by applying for the LORE method. By identifying the divergences in the UVDP-parameter space to those in the subdiagrams of two loop diagrams, we arrive at the Bjorken-Drell's analogy between Feynman diagrams and electrical circuits, where the UVDP parameters are associated with the conductance or resistance in the electrical circuits. In particular, the sets o...

  2. Acquiring Knowledge in Learning Concepts from Electrical Circuits: The Use of Multiple Representations in Technology-Based Learning Environments

    Directory of Open Access Journals (Sweden)

    Abdeljalil Métioui

    2012-04-01

    Full Text Available The constructivists approach on the conception of relative software of modelling to training and teaching of the concepts of current and voltage requires appraisal of several disciplinary fields in order to provide to the learners a training adapted to their representations. Thus, this approach requires the researchers to have adequate knowledge or skills in data processing, didactics and science content. In this regard, several researches underline that the acquisition of basic concepts that span a field of a given knowledge, must take into account the student and the scientific representations. The present research appears in this perspective, and aims to present the interactive computer environments that take into account the students (secondary and college and scientific representations related to simple electric circuits. These computer environments will help the students to analyze the functions of the electric circuits adequately.

  3. 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...

  4. Analytical Solutions of the Electrical RLC Circuit via Liouville–Caputo Operators with Local and Non-Local Kernels

    Directory of Open Access Journals (Sweden)

    José Francisco Gómez-Aguilar

    2016-08-01

    Full Text Available In this work we obtain analytical solutions for the electrical RLC circuit model defined with Liouville–Caputo, Caputo–Fabrizio and the new fractional derivative based in the Mittag-Leffler function. Numerical simulations of alternative models are presented for evaluating the effectiveness of these representations. Different source terms are considered in the fractional differential equations. The classical behaviors are recovered when the fractional order α is equal to 1.

  5. Ubiquity of chaotic magnetic-field lines generated by three-dimensionally crossed wires in modern electric circuits.

    Science.gov (United States)

    Hosoda, M; Miyaguchi, T; Imagawa, K; Nakamura, K

    2009-12-01

    We investigate simple three-dimensionally crossed wires carrying electric currents which generate chaotic magnetic-field lines (CMFLs). As such wire systems, cross-ring and perturbed parallel-ring wires are studied, since topologically equivalent configurations to these systems can often be found in contemporary electric and integrated circuits. For realistic fundamental wire configurations, the conditions for wire dimensions (size) and current values to generate CMFLs are numerically explored under the presence of the weak but inevitable geomagnetic field. As a result, it is concluded that CMFLs can exist everywhere; i.e., they are ubiquitous in the modern technological world.

  6. 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.

  7. Effects of the Physical Laboratory versus the Virtual Laboratory in Teaching Simple Electric Circuits on Conceptual Achievement and Attitudes Towards the Subject

    Science.gov (United States)

    Tekbiyik, Ahmet; Ercan, Orhan

    2015-01-01

    Current study examined the effects of virtual and physical laboratory practices on students' conceptual achievement in the subject of electricity and their attitudes towards simple electric circuits. Two groups (virtual and physical) selected through simple random sampling was taught with web-aided material called "Electricity in Our…

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

    Science.gov (United States)

    Lee, Jaeryeong; Kim, Youngjin; Lee, Jae-chun

    2012-11-30

    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 (E(area)) and the weight ratio of the detached EECs (E(weight)). In the disassembly treatment, these efficiencies were improved with an increase of grinder speed and grinder height. 97.7% (E(area)) and 98% (E(weight)) could be accomplished ultimately by 3 repetitive treatments at a grinder speed of 5500 rpm and a grinder height of 1.5mm. 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 distribution ratio (R(dis)) and the concentration ratio (R(conc)) were used. 15 elements could be separated with the highest R(dis) and R(conc) in the same separated division. This result implies that the recyclability of the elements is highly feasible, even though the initial content in EECs is lower than several tens of mg/kg.

  9. Quantum Fluctuation in Thermal Vacuum State for Mesoscopic LC Electric Circuit

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; LIANG Xian-Ting

    2000-01-01

    We consider the quantization of LC (inductance-capacitance) circuit at a finite temperature T as any practical circuits always produce Joule heat except for superconductivity. It is shown that the quantum mechanical zeropoint fluctuations of both charge and current increase with upgoing T. Thermal field dynamics is used in ourdiscussion.

  10. Quantum Fluctuation in Mesoscopic Coupled LC Electric Circuits at FiniteTemperature

    Institute of Scientific and Technical Information of China (English)

    LIANG Xian-Ting; FAN Hong-Yi

    2001-01-01

    We consider the quantization of two coupled LC circuits with mutual inductance at a finite temperature T. It is shown that the quantum mechanical zero-point fluctuations of currents in the two circuits both increase with upgoing T. Thermal field dynamics and Weyl-Wigner theorern are used in our calculation of ensemble average of the observables.

  11. 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.

  12. First Measurements of the Earth's Electric Field at the Arctowski Antarctic Station, King George Island, by the New Polish Atmospheric Electricity Observation Network

    Science.gov (United States)

    Kubicki, Marek; Odzimek, Anna; Neska, Mariusz; Berliński, Jerzy; Michnowski, Stanisław

    2016-12-01

    Atmospheric electricity measurements are performed all over the globe for getting a better understanding of the processes and phenomena operating in the Earth's electric atmosphere, ionosphere and magnetosphere. Over recent years, we have established coordinated observations of atmospheric electricity, mainly of the vertical component of the Earth's atmospheric electric field, from Polish observation stations: Stanisław Kalinowski Geophysical Observatory in Świder, Poland, Stanisław Siedlecki Polar Station in Hornsund, Svalbard, Norway, and, for the first time, the Henryk Arctowski Antarctic Station in King George Island. The organisation of this network is presented here as well as a preliminary summary of geophysical conditions at Arctowski, important from the point of view of atmospheric electricity observations. In particular, we refer to the geomagnetic observations made at Arctowski station in 1978-1995. We also present the average fair-weather diurnal variation of the atmospheric electric field based on observations made so far between 2013 and 2015.

  13. Effects of Electric Contact Failure on Signal Transmission in the Lossy Circuits

    Institute of Scientific and Technical Information of China (English)

    CHEN Ya; SUN Bai-sheng

    2004-01-01

    Based on the former research results of the influence of contact failure in ideal and unmatched circuits, this paper further studies theoretically the effects of contact failure on the digital signal transmission in the lossy circuits, which may happen widely in practical applications. Experiences show that even in high-quality lines, losses deform the voltage and current wave shapes owing to their effects on the amplitude of the various waves making up the over-all line voltage and current. Although the derivations show that the effects of contact failure in the lossy circuits on the signal transmission are quite complicated. The probability of occurrence of error codes can be increased significantly.

  14. 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.

  15. Investigation of the influence of inert and oxidizing atmospheres on the efficiency of decomposition of waste printed circuit boards (WPCBs)

    Science.gov (United States)

    Kumari, Anjan; Jha, Manis Kumar; Singh, Rajendra Prasad; Ranganathan, S.

    2016-08-01

    Thermo-gravimetry was used for studying the influence of the furnace atmosphere during the pyrolysis waste circuit boards (WPCBs). Pyrolysis in argon atmosphere resulted in a continuous decrease of mass of the sample. Rapid mass loss occurred at about 573 K. Heating the WPCBs in air and oxygen atmospheres resulted in an increase in the mass of the sample in the early stages until rapid mass loss occurred at about 573 K. When pyrolysis of larger sample mass (about 5 g each) was carried out in tubular furnace, about 20.43 % mass loss was observed during the pyrolysis of WPCBs in a flowing stream of argon at 548 K during a period of 4 min. On the other hand, a maximum of about 2.26 % mass loss was recorded when the WPCBs were heated at about 600 K for the same time interval in the still air. The mass transfer during the pyrolysis of WPCBs in flowing stream of inert gas was also modeled. It is found that controlling the flow rate of inert gas and the geometry of the equipment can enhance the rate of mass loss significantly.

  16. Physically based analysis of electrical frequency response of passive microelectronic circuits by heterodyne lock-in thermal means

    Science.gov (United States)

    León, J.; Perpiñà, X.; Altet, J.; Vellvehi, M.; Jordà, X.

    2013-11-01

    This paper combines the heterodyne modulation technique with lock-in detection approaches to characterize the electrical behaviour of electronic systems in the frequency domain by thermal means. A thermal test chip (TTC), featuring a heating resistor and an embedded thermal sensor, is used as a test vehicle to assess this approach. The frequency response of the heating resistor has been first characterized by electrical measurements, yielding to a suitable TTC equivalent circuit which qualitatively explains its behaviour. Then, in order to infer this behaviour by thermal means, the heating resistor temperature has been heterodynally detected by on-chip local sensing (embedded thermal sensor) and off-chip spatially resolved (infrared lock-in thermography) techniques. The results of this paper show that from low-frequency temperature measurements it is possible to obtain the electrical frequency response of the TTC and to detect and locate capacitive coupling that disturbs the high-frequency operation of the device.

  17. 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.

  18. Transmission of the electric fields to the low latitude ionosphere in the magnetosphere-ionosphere current circuit

    Science.gov (United States)

    Kikuchi, Takashi; Hashimoto, Kumiko K.

    2016-12-01

    The solar wind energy is transmitted to low latitude ionosphere in a current circuit from a dynamo in the magnetosphere to the equatorial ionosphere via the polar ionosphere. During the substorm growth phase and storm main phase, the dawn-to-dusk convection electric field is intensified by the southward interplanetary magnetic field (IMF), driving the ionospheric DP2 currents composed of two-cell Hall current vortices in high latitudes and Pedersen currents amplified at the dayside equator (EEJ). The EEJ-Region-1 field-aligned current (R1 FAC) circuit is completed via the Pedersen currents in midlatitude. On the other hand, the shielding electric field and the Region-2 FACs develop in the inner magnetosphere, tending to cancel the convection electric field at the mid-equatorial latitudes. The shielding often causes overshielding when the convection electric field reduces substantially and the EEJ is overcome by the counter electrojet (CEJ), leading to that even the quasi-periodic DP2 fluctuations are contributed by the overshielding as being composed of the EEJ and CEJ. The overshielding develop significantly during substorms and storms, leading to that the mid and low latitude ionosphere is under strong influence of the overshielding as well as the convection electric fields. The electric fields on the day- and night sides are in opposite direction to each other, but the electric fields in the evening are anomalously enhanced in the same direction as in the day. The evening anomaly is a unique feature of the electric potential distribution in the global ionosphere. DP2-type electric field and currents develop during the transient/short-term geomagnetic disturbances like the geomagnetic sudden commencements (SC), which appear simultaneously at high latitude and equator within the temporal resolution of 10 s. Using the SC, we can confirm that the electric potential and currents are transmitted near-instantaneously to low latitude ionosphere on both day- and night

  19. 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

  20. Evaluation of Atmospheric Electric Field as Increasing Seismic Activity Indicator on the example of Caucasus Region

    CERN Document Server

    Kachakhidze, M K; Kachakhidze, N K

    2012-01-01

    The present paper deals with reliability of a gradient of atmospheric electric field potential as an indicator of seismic activity increase. With this in view, records of atmospheric electric field potential gradients of Caucasus region for 1953-1992 with respect to periods before average and large earthquakes, which took place in the same time interval, were considered. It is worth to pay attention to the fact that the avalanche-like unstable model of fault formation based on theoretical model of self-generated seismo-electromagnetic oscillations of LAI system explains convincingly spectral succession of electromagnetic emission frequency of the periods preceding earthquakes.

  1. 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 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...

  2. 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

  3. 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)

  4. 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.

  5. Solenoid-Simulation Circuit

    Science.gov (United States)

    Simon, R. A.

    1986-01-01

    Electrical properties of solenoids imitated for tests of control circuits. Simulation circuit imitates voltage and current responses of two engine-controlling solenoids. Used in tests of programs of digital engine-control circuits, also provides electronic interface with circuits imitating electrical properties of pressure sensors and linear variable-differential transformers. Produces voltages, currents, delays, and discrete turnon and turnoff signals representing operation of solenoid in engine-control relay. Many such circuits used simulating overall engine circuitry.

  6. 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.

  7. Three-dimensional modelling of electric-arc development in a low-voltage circuit-breaker

    Energy Technology Data Exchange (ETDEWEB)

    Piqueras, L.; Henry, D.; Jeandel, D.; Scott, J. [Laboratoire de Mecanique des Fluides et d' Acoustique, CNRS/Universite de Lyon, Ecole Centrale de Lyon/Universite Lyon 1/INSA de Lyon, ECL, 36 avenue Guy de Collongue, 69134 Ecully Cedex (France); Wild, J. [Schneider Electric, 37 quai Merlin, 38050 Grenoble Cedex 9 (France)

    2008-09-15

    This article describes direct numerical simulation of the first three milliseconds following ignition of the arc in a low-voltage circuit-breaker using a computational-fluid-dynamics code adapted for electric-arc modelling. The mobile electrode is allowed for by a moving mesh. The results describe the evolution of the arc with time in terms of its detailed electrical, thermal and fluid dynamic properties. They allow the identification of several phases during the overall arc development process studied here: arc initialisation in the widening electrode gap, arc-thermal expansion, displacement of the arc towards the tip of the mobile electrode, and the beginning of commutation to the fixed electrode. (author)

  8. 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.

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

    NARCIS (Netherlands)

    Trinh, T. N. G.; Scholten, O.; Buitink, S.; van den Berg, A. M.; Corstanje, A.; Ebert, U.; Enriquez, J. E.; Falcke, H.; Horandel, J. R.; Kohn, 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-

  10. 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.

  11. 基于Pockels效应的大气电场测量研究%Study on atmospheric electric field measurement based on Pockels effect

    Institute of Scientific and Technical Information of China (English)

    周龙; 行鸿彦; 张志鹏; 陈洁; 吴安坤

    2012-01-01

    为解决常用场磨式大气电场仪体积大、机械磨损严重、易受电磁干扰、测量带宽窄等问题,在研究分析Pockels效应原理的基础上,提出应用Pockels效应来测量大气电场的方法.对晶体、光源的选择及传感器设计中出现的问题进行了分析,设计了一种基于Pockels效应原理的脉冲电场传感器,该传感系统包括稳定高效的光源、Pockels晶体探头、数据采集及处理电路.通过模拟仿真,说明了这种测量方法是可行的,为进一步研制大气电场测量传感器,提高其性能提供了理论依据.%In order to solve some problems of the common atmospheric electric field mill, such as bulk mass, serious abrasion, electromagnetic interference and narrow bandwidth, this paper advanced a new way to measure atmospheric electric field which is based on the research of Pockels effect, analyzed the choice problem of crystal and light source, and others which appeared during the course of design this sensor, and designed a pulse electric field sensor which was based on Pockels effect. This system consist of stable and high-efficiency light source, Pockels detector, data acquisition and processing circuit. According to the analog simulation, this method of measuring atmospheric electric field is workable, in this way it afford a basis for further design of this atmospheric electric field sensor and improving tt' s performance.

  12. Progresses in the Atmospheric Electricity Researches in China during 2006-2010

    Institute of Scientific and Technical Information of China (English)

    QIE Xiushu

    2012-01-01

    Atmospheric electricity is composed of a wide range of electric phenomena m the troposphere,stratosphere,and even lower ionosphere. Research progress on atmospheric electricity in the past 5 years in China are briefly reviewed here. This research area has been greatly expanded through rocket-triggered lightning experiments and the increased use of high spatio-temporal resolution techniques for the detection and location of lightning.The main results described in this review are summarized in the following five aspects:(1) processes and parameters inferred from rocket-triggered lightning,(2) lightning physics and effects (observations and theoretical study),(3) lightning activities associated with different thunderstorms,(4) charge structure of thunderstorms (observations and simulation),and (5) the VHF/UHF lightning location techniques and discharge channel mapping.

  13. Julius Elster and Hans Geitel - Dioscuri of physics and pioneer investigators in atmospheric electricity

    Science.gov (United States)

    Fricke, Rudolf G. A.; Schlegel, Kristian

    2017-01-01

    Julius Elster and Hans Geitel contributed to the physics at the turn of the 19-20th century in many ways. We first summarize the life of these exceptional scientists. Then - owing to the topic of this journal - we focus on their atmospheric electricity research. With their experiments, careful evaluations and ingenious interpretation, Elster and Geitel made important contributions to precipitation electricity, the influence of solar radiation on the electric state of the atmosphere, the nature of charge carriers and the ionization of air by radioactivity. They proved their experimental skills by inventing new instruments with unprecedented accuracy and reliability. A very modern concept was their attitude to undertake long-term measurements at various locations. A section on their recognition in the physics community and their scientific distinctions concludes the paper.

  14. Electrical and optical properties of Ar/NH3 atmospheric pressure plasma jet

    Science.gov (United States)

    Chang, Zheng-Shi; Yao, Cong-Wei; Chen, Si-Le; Zhang, Guan-Jun

    2016-09-01

    Inspired by the Penning effect, we obtain a glow-like plasma jet by mixing ammonia (NH3) into argon (Ar) gas under atmospheric pressure. The basic electrical and optical properties of an atmospheric pressure plasma jet (APPJ) are investigated. It can be seen that the discharge mode transforms from filamentary to glow-like when a little ammonia is added into the pure argon. The electrical and optical analyses contribute to the explanation of this phenomenon. The discharge mode, power, and current density are analyzed to understand the electrical behavior of the APPJ. Meanwhile, the discharge images, APPJ's length, and the components of plasma are also obtained to express its optical characteristics. Finally, we diagnose several parameters, such as gas temperature, electron temperature, and density, as well as the density number of metastable argon atoms of Ar/NH3 APPJ to help judge the usability in its applications.

  15. 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.

  16. High-fidelity pulse density modulation in neuromorphic electric circuits utilizing natural heterogeneity

    Science.gov (United States)

    Utagawa, Akira; Asai, Tetsuya; Amemiya, Yoshihito

    Hospedales et al. have recently proposed a neural network model of the “vestibulo-ocular reflex” (VOR) in which a common input was given to multiple nonidentical spiking neurons that were exposed to uncorrelated temporal noise, and the output was represented by the sum of these neurons. Although the function of the VOR network is equivalent to pulse density modulation, the neurons' non-uniformity and temporal noises given to the neurons were shown to improve the output spike's fidelity to the analog input. In this paper, we propose a CMOS analog circuit for implementing the VOR network that exploits the non-uniformity of real MOS devices. Through extensive laboratory experiments using discrete MOS devices, we show that the output's fidelity to the input pulses is clearly improved by using multiple neuron circuits, in which the non-uniformity is naturally embedded into the devices.

  17. 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.

  18. 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.

  19. Anterior wrist and medial malleolus as the novel sites of tissue selection: a retrospective study on electric shock death through the hand-to-foot circuit pathway.

    Science.gov (United States)

    Xu, Guangtao; Su, Ruibing; Lv, Junyao; Hu, Bo; Gu, Huan; Li, Xianxian; Gu, Jiang; Yu, Xiaojun

    2017-01-06

    Our previous work demonstrated that characteristic changes could occur in the anterior wrist and medial malleolus in electric deaths through the hand-to-foot electric circuit pathway in an electric shock rat model. However, whether the same phenomenon occurs in humans is unknown. The aim of the present retrospective study was to ascertain whether the anterior wrist and medial malleolus could also be selected as the promising and significant sites in electric death through the hand-to-foot circuit pathway. Nineteen human cases from the autopsy and one clinical survivor who sustained a severe electric shock through the hand-to-foot circuit pathway were analyzed. Additional ten autopsy patients who died from traffic accidents and sudden cardiac attacks were used as the control group. Histopathological changes in the soft tissues of the anterior wrist and medial malleolus in all autopsy patients, as well as the electric current pathway of the survivor, were observed. The results showed that the nuclear polarizations in the anterior wrist and medial malleolus soft tissues of the electric death were extremely noticeable as compared with the controls. The most severe electrical injury in the survivor occurred in the anterior wrist. These findings suggest that the soft tissues of the anterior wrist and/or the medial malleolus as the narrowest parts of the limbs could be used as the complementary sites for tissue selection and considered as necessary locations for examinations to assess the electric death in medicolegal identification.

  20. Circuit modification in electrical field flow fractionation systems generating higher resolution separation of nanoparticles.

    Science.gov (United States)

    Tasci, Tonguc O; Johnson, William P; Fernandez, Diego P; Manangon, Eliana; Gale, Bruce K

    2014-10-24

    Compared to other sub-techniques of field flow fractionation (FFF), cyclical electrical field flow fractionation (CyElFFF) is a relatively new method with many opportunities remaining for improvement. One of the most important limitations of this method is the separation of particles smaller than 100nm. For such small particles, the diffusion rate becomes very high, resulting in severe reductions in the CyElFFF separation efficiency. To address this limitation, we modified the electrical circuitry of the ElFFF system. In all earlier ElFFF reports, electrical power sources have been directly connected to the ElFFF channel electrodes, and no alteration has been made in the electrical circuitry of the system. In this work, by using discrete electrical components, such as resistors and diodes, we improved the effective electric field in the system to allow high resolution separations. By modifying the electrical circuitry of the ElFFF system, high resolution separations of 15 and 40nm gold nanoparticles were achieved. The effects of applying different frequencies, amplitudes and voltage shapes have been investigated and analyzed through experiments.

  1. 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'.

  2. 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.

  3. 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.

  4. ZER4型蓄电池电力工程车主电路分析%The Main Circuit Analysis of ZER4 Battery Electric Locomotives

    Institute of Scientific and Technical Information of China (English)

    卢玉丹; 丁伟民; 李琛玫

    2016-01-01

    This article mainly take ZER4 Battery Electric Locomotives for example detailed presents the following aspects: from structure of main circuit, technical parameters, principle of main circuit, power supply mode conversion and circuit protection.%主要以ZER4型蓄电池电力工程车为例,从主电路结构、主要技术参数、主电路原理、各供电模式转换分析及电路保护等进行详尽的阐述。

  5. 车载网络技术对汽车传统电路的影响%Influence of Vehicle Network Technology on Traditional Vehicle electric Circuit

    Institute of Scientific and Technical Information of China (English)

    宋捷

    2013-01-01

      文章论述了车载网络技术对汽车传统电路的影响。通过比较前照灯的传统电路与自适应前照明系统工作原理和布线方式等方面的不同,说明传统汽车电路已经远远不能满足智能汽车的需要。%The thesis discuss influence of vehicle network technology on traditional vehicle electric circuit. According to comparing with the headlamp traditional electric circuit and adaptive font-lighting system , we conclude that the tradi-tional automobile electric circuit data transmission has been far from satisfying the needs of the smart car.

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

    Science.gov (United States)

    Kumagai, Daisuke; Ohsaki, Hiroyuki; Tomita, Masaru

    2016-12-01

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

  7. 直流与交流电气线路中铜导线短路痕迹的分析%Analysis on short circuit trace of copper wire in direct and alternating current electric circuits

    Institute of Scientific and Technical Information of China (English)

    王连铁; 高伟; 赵长征; 袁晓光

    2012-01-01

    直流电气线路及交流电气线路中铜导线发生短路故障时所形成的熔痕的组织特征不同,为区分二者之间的差别,利用模拟试验手段制备出金相样品,并采用宏观分析、金相分析等各种技术手段进行分析总结,归纳出二者发生短路故障时所形成的痕迹特征规律.模拟研究结果表明,直流线路一次短路熔痕的金相组织以细小的柱状晶为主,且孔洞较少;在交流线路中,一次短路故障形成的熔痕的金相组织胞状晶较多,且交、直流电气线路中铜导线发生短路故障时所形成的熔痕的组织特征明显不同,这些特征可用于实际鉴定工作中.%The microstructural characteristics of melted marks formed due to the short circuit fault of copper wire in direct current(DC) and alternating current(AC) electric circuits are different.In order to distinguish the difference between them,the metallographic samples were prepared through the simulation tests.In addition,such technical means as macro analysis and metallographic analysis were used to analyze and summarize the characteristics of the mark formed due to the short circuit fault in DC and AC electric circuits.The simulation results show that the microstructures of melted marks formed due to the primary short circuit fault in DC circuit are mainly composed of fine columnar crystals with fewer holes.However,the microstructures of melted marks formed due to the primary short circuit fault in AC circuit contain more cellular crystals.Furthermore,the microstructural characteristics of melted marks formed due to the short circuit faults of copper wire in DC and AC electric circuits are obviously different,and can provide the reference for the actual identification work.

  8. Properties and application of a multichannel integrated circuit for low-artifact, patterned electrical stimulation of neural tissue

    Science.gov (United States)

    Hottowy, Paweł; Skoczeń, Andrzej; Gunning, Deborah E.; Kachiguine, Sergei; Mathieson, Keith; Sher, Alexander; Wiącek, Piotr; Litke, Alan M.; Dąbrowski, Władysław

    2012-01-01

    Objective Modern multielectrode array (MEA) systems can record the neuronal activity from thousands of electrodes, but their ability to provide spatio-temporal patterns of electrical stimulation is very limited. Furthermore, the stimulus-related artifacts significantly limit the ability to record the neuronal responses to the stimulation. To address these issues, we designed a multichannel integrated circuit for patterned MEA-based electrical stimulation and evaluated its performance in experiments with isolated mouse and rat retina. Approach The Stimchip includes 64 independent stimulation channels. Each channel comprises an internal digital-to-analog converter that can be configured as a current or voltage source. The shape of the stimulation waveform is defined independently for each channel by the real-time data stream. In addition, each channel is equipped with circuitry for reduction of the stimulus artifact. Main results Using a high-density MEA stimulation/recording system, we effectively stimulated individual retinal ganglion cells (RGCs) and recorded the neuronal responses with minimal distortion, even on the stimulating electrodes. We independently stimulated a population of RGCs in rat retina and, using a complex spatio-temporal pattern of electrical stimulation pulses, we replicated visually-evoked spiking activity of a subset of these cells with high fidelity. Significance Compared with current state-of-the-art MEA systems, the Stimchip is able to stimulate neuronal cells with much more complex sequences of electrical pulses and with significantly reduced artifacts. This opens up new possibilities for studies of neuronal responses to electrical stimulation, both in the context of neuroscience research and in the development of neuroprosthetic devices. PMID:23160018

  9. Theoretical Computation for Non-Equilibrium Air Plasma Electrical Conductivity at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    HAN Dong; GUO Wen-Kang; XU Ping; LIANG Rong-Qing

    2007-01-01

    @@ 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 15000K, the present result is compared with Murphy's study [Plasma Chem. Plasma Process 15 (1994) 279] 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.

  10. 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

    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...... 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 cars...

  11. 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.

  12. A study of the contribution of thunderstorms to the Global Electric Circuit using a time dependent numerical model and a fractal model

    Science.gov (United States)

    Mallios, Sotirios A.

    The Global Electric Circuit (GEC) is a circuit that is formed between the Earth's surface, which is a good conductor of electricity, and the ionosphere, a weakly-ionized plasma at ˜80 km altitude. Thunderstorms are believed to be the major charging sources of this circuit. In this dissertation, we present our studies on the contribution of thunderstorms to the Global electric Circuit. We examine the current that is driven to the ionosphere and to the ground before, during and after single negative cloud-to-ground (CG) and intra-cloud (IC) lightning discharges. A numerical model has been developed, that calculates the quasi-electrostatic field before the lightning, due to the slow accumulation of the charge in the thunder-cloud, and after the lightning by taking into account the Maxwellian relaxation of the charges in the conducting atmosphere and accounting for the dissipation stage of the thunderstorm development. From these results, the charges that are transferred to the ionosphere and to the ground are calculated. We demonstrate the significance of considering the pre-lightning and the dissipation stages and accounting for realistic distribution of the conductivity inside of the thundercloud for the accurate calculation of the charge flow to the ionosphere and to the ground. We show that the charge transfer to the ionosphere depends mainly on the altitudes of the charges inside the thundercloud and their spatial separation. The amount of charge that is transferred to the ground, due to currents flowing in the vicinity of the thundercloud during a transient time period following a lightning discharge, is significantly affected by the conductivity distribution in the thundercloud and can be several times smaller than the amount of charge that is transferred to the ionosphere during the same time period. Moreover, we show that the duration of each of the thunderstorm life cycle stages affects the results. Furthermore, we show the influence of the corona currents

  13. Experimental verification of a thermal equivalent circuit dynamic model on an extended range electric vehicle battery pack

    Science.gov (United States)

    Ramotar, Lokendra; Rohrauer, Greg L.; Filion, Ryan; MacDonald, Kathryn

    2017-03-01

    The development of a dynamic thermal battery model for hybrid and electric vehicles is realized. A thermal equivalent circuit model is created which aims to capture and understand the heat propagation from the cells through the entire pack and to the environment using a production vehicle battery pack for model validation. The inclusion of production hardware and the liquid battery thermal management system components into the model considers physical and geometric properties to calculate thermal resistances of components (conduction, convection and radiation) along with their associated heat capacity. Various heat sources/sinks comprise the remaining model elements. Analog equivalent circuit simulations using PSpice are compared to experimental results to validate internal temperature nodes and heat rates measured through various elements, which are then employed to refine the model further. Agreement with experimental results indicates the proposed method allows for a comprehensive real-time battery pack analysis at little computational expense when compared to other types of computer based simulations. Elevated road and ambient conditions in Mesa, Arizona are simulated on a parked vehicle with varying quiescent cooling rates to examine the effect on the diurnal battery temperature for longer term static exposure. A typical daily driving schedule is also simulated and examined.

  14. The Equivalent Electrokinetic Circuit Model of Ion Concentration Polarization Layer: Electrical Double Layer, Extended Space Charge and Electro-convection

    Science.gov (United States)

    Cho, Inhee; Huh, Keon; Kwak, Rhokyun; Lee, Hyomin; Kim, Sung Jae

    2016-11-01

    The first direct chronopotentiometric measurement was provided to distinguish the potential difference through the extended space charge (ESC) layer which is formed with the electrical double layer (EDL) near a perm-selective membrane. From this experimental result, the linear relationship was obtained between the resistance of ESC and the applied current density. Furthermore, we observed the step-wise distributions of relaxation time at the limiting current regime, confirming the existence of ESC capacitance other than EDL's. In addition, we proposed the equivalent electrokinetic circuit model inside ion concentration polarization (ICP) layer under rigorous consideration of EDL, ESC and electro-convection (EC). In order to elucidate the voltage configuration in chronopotentiometric measurement, the EC component was considered as the "dependent voltage source" which is serially connected to the ESC layer. This model successfully described the charging behavior of the ESC layer with or without EC, where both cases determined each relaxation time, respectively. Finally, we quantitatively verified their values utilizing the Poisson-Nernst-Planck equations. Therefore, this unified circuit model would provide a key insight of ICP system and potential energy-efficient applications.

  15. The effect of dust lifting process on the electrical properties of the atmosphere

    Science.gov (United States)

    Esposito, Francesca; Molinaro, Roberto; Ionut Popa, Ciprian; Molfese, Cesare; Cozzolino, Fabio; Marty, Laurent; Taj-Eddine, Kamal; Di Achille, Gaetano; Silvestro, Simone; Ori, Gian Gabriele

    2015-04-01

    Airborne dust and aerosol particles affect climate by absorbing and scattering thermal and solar radiation and acting as condensation nuclei for the formation of clouds. So, they strongly influence the atmospheric thermal structure, balance and circulation. On Earth and Mars, this 'climate forcing' is one of the most uncertain processes in climate change predictions. Wind-driven blowing of sand and dust is also responsible for shaping planetary surfaces through the formation of sand dunes and ripples, the erosion of rocks, and the creation and transport of soil particles. These processes are not confined to Earth, but occur also on Mars, Venus and Titan. It is clear that the knowledge of the atmospheric dust properties and the mechanisms of dust settling and raising into the atmosphere are important to understand planetary climate and surface evolution. On Mars the physical processes responsible for dust injection into the atmosphere are still poorly understood, but they likely involve saltation as on Earth. Saltation is a process where large sand grains are forced by the wind to move in ballistic trajectories on the soil surface. During these hops they hit dust particles, that are well bound to the soil due to interparticle cohesive forces, thus transferring to them the momentum necessary to be entrained into the atmosphere. Recently, it has been shown that this process is also responsible to generate strong electric fields in the atmosphere up to 100-150 kV/m. This enhanced electric force acts as a feedback in the dust lifting process, lowering the threshold of the wind friction velocity u* necessary to initiate sand saltation. It is an important aspect of dust lifting process that need to be well characterized and modeled. Even if literature reports several measurements of E-fields in dust devils events, very few reports deal with atmospheric electric properties during dust storms or isolated gusts. We present here preliminary results of an intense field test

  16. 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.

  17. Ambipolar Electric Field, Photoelectrons, and their Role in Atmospheric Escape From Hot-jupiters

    CERN Document Server

    Cohen, O

    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 the 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 ma...

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

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, O. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Glocer, A. [NASA/GSFC, Code 673, Greenbelt, MD 20771 (United States)

    2012-07-01

    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.

  19. First Measurements of the Earth’s Electric Field at the Arctowski Antarctic Station, King George Island, by the New Polish Atmospheric Electricity Observation Network

    Directory of Open Access Journals (Sweden)

    Kubicki Marek

    2016-12-01

    Full Text Available Atmospheric electricity measurements are performed all over the globe for getting a better understanding of the processes and phenomena operating in the Earth’s electric atmosphere, ionosphere and magnetosphere. Over recent years, we have established coordinated observations of atmospheric electricity, mainly of the vertical component of the Earth’s atmospheric electric field, from Polish observation stations: Stanisław Kalinowski Geophysical Observatory in Świder, Poland, Stanisław Siedlecki Polar Station in Hornsund, Svalbard, Norway, and, for the first time, the Henryk Arctowski Antarctic Station in King George Island. The organisation of this network is presented here as well as a preliminary summary of geophysical conditions at Arctowski, important from the point of view of atmospheric electricity observations. In particular, we refer to the geomagnetic observations made at Arctowski station in 1978-1995. We also present the average fair-weather diurnal variation of the atmospheric electric field based on observations made so far between 2013 and 2015.

  20. Probing Atmospheric Electric Fields through Radio Emission from Cosmic-Ray-Induced Air Showers

    Science.gov (United States)

    Scholten, Olaf; Trinh, Gia; Buitink, Stijn; Corstanje, Arthur; Ebert, Ute; Enriquez, Emilio; Falcke, Heino; Hoerandel, Joerg; Nelles, Anna; Schellart, Pim; Rachen, Joerg; Rutjes, Casper; ter Veen, Sander; Rossetto, Laura; Thoudam, Satyendra

    2016-04-01

    Energetic cosmic rays impinging on the atmosphere create a particle avalanche called an extensive air shower. In the leading plasma of this shower electric currents are induced that generate coherent radio wave emission that has been detected with LOFAR, a large and dense array of simple radio antennas primarily developed for radio-astronomy observations. Our measurements are performed in the 30-80 MHz frequency band. For fair weather conditions the observations are in excellent agreement with model calculations. However, for air showers measured under thunderstorm conditions we observe large differences in the intensity and polarization patterns from the predictions of fair weather models. We will show that the linear as well as the circular polarization of the radio waves carry clear information on the magnitude and orientation of the electric fields at different heights in the thunderstorm clouds. We will show that from the measured data at LOFAR the thunderstorm electric fields can be reconstructed. We thus have established the measurement of radio emission from extensive air showers induced by cosmic rays as a new tool to probe the atmospheric electric fields present in thunderclouds in a non-intrusive way. In part this presentation is based on the work: P. Schellart et al., Phys. Rev. Lett. 114, 165001 (2015).

  1. Fabrication and electrical characterization of sub-micron diameter through-silicon via for heterogeneous three-dimensional integrated circuits

    Science.gov (United States)

    Abbaspour, R.; Brown, D. K.; Bakir, M. S.

    2017-02-01

    This paper presents the fabrication and electrical characterization of high aspect-ratio (AR) sub-micron diameter through silicon vias (TSVs) for densely interconnected three-dimensional (3D) stacked integrated circuits (ICs). The fabricated TSV technology features an AR of 16:1 with 680 nm diameter copper (Cu) core and 920 nm overall diameter. To address the challenges in scaling TSVs, scallop-free low roughness nano-Bosch silicon etching and direct Cu electroplating on a titanium-nitride (TiN) diffusion barrier layer have been developed as key enabling modules. The electrical resistance of the sub-micron TSVs is measured to be on average 1.2 Ω, and the Cu resistivity is extracted to be approximately 2.95 µΩ cm. Furthermore, the maximum achievable current-carrying capacity (CCC) of the scaled TSVs is characterized to be approximately 360 µA for the 680 nm Cu core.

  2. Do Skilled Elementary Teachers Hold Scientific Conceptions and Can They Accurately Predict the Type and Source of Students' Preconceptions of Electric Circuits?

    Science.gov (United States)

    Lin, Jing-Wen

    2016-01-01

    Holding scientific conceptions and having the ability to accurately predict students' preconceptions are a prerequisite for science teachers to design appropriate constructivist-oriented learning experiences. This study explored the types and sources of students' preconceptions of electric circuits. First, 438 grade 3 (9 years old) students were…

  3. 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.

  4. 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…

  5. Calculation of cooling internal circuits loss of load curve in giant electric machines; Calculo da curva de perda de carga dos circuitos axiais internos de refrigeracao de maquinas eletricas gigantes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Hilton Penha [Parana Univ., Curitiba, PR (Brazil). Dept. de Engenharia Mecanica. Dept. de Engenharia do Produto; Passos, Alex Sandro Barbosa [Parana Univ., Curitiba, PR (Brazil). Dept. de Engenharia Mecanica. Dept. de Pesquisa e Desenvolvimento do Produto

    2001-07-01

    This article describes a method for calculation of the loss of load curve for the ventilation axial circuits. The method assumes the ventilation circuit representation in a way similar to the electrical circuits. The great difficulty of circuit solution resides in the non linearity of the loss of load resistances and the equations relating the pressures and flows. The method is based on the association of the resistance curves of loss of load in a such way that, when the resistance curve of the total circuit loss of load is obtained, the blower operation point can be easily obtained and, consequently, the individual flows for each section of the circuit.

  6. 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

  7. Magnetic circuit of a contactless torque sensor for electric power steering

    Science.gov (United States)

    Fröhlich, Ekkehart; Jerems, Frank

    Modern passenger cars are increasingly equipped with electromechanical steering assist rather than hydraulic systems known for many decades. Major benefits are reduced fuel consumption (up to 0.2l/100 km) and increased functionality. As such a system reacts to the drivers input in terms of steering torque or steering effort, a sensor is required that accurately measures the steering torque. Valeo has adopted a magnetic technology and has improved the performance by adding specially designed flux concentration devices. The magnetic circuit consists of a multi-pole ring magnet and a pair of ring-shaped soft magnetic parts rotating together with the steering shaft and an additional pair of soft magnetic flux concentration devices which are fixed stationary inside the housing. The steering torque causes a relative twist between magnet and the soft magnetic rings, therefore implementing a proportional magnetisation of the latter. A U-shape was chosen for the flux concentration devices in order to compensate mechanical tolerances of the system. The main focus of this paper will be on the tolerance behaviour of the sensor system and the impact of the flux concentration devices. Because of the nonlinear nature of the magnetisation curve of the NiFe alloy used extensive 3D FEM simulation was necessary. Simulation enables us to have a look inside the soft magnetic material and predict the spatial magnetisation distribution with the benefit of avoiding saturation. The result is an optimised sensor, which meets both the harsh environmental conditions inside the motor compartment as well as the cost pressure in the automotive business.

  8. Electric field effect on the zigzag (6,0) single-wall BC2N nanotube for use in nano-electronic circuits.

    Science.gov (United States)

    Baei, Mohammad T; Peyghan, Ali Ahmadi; Moghimi, Masoumeh; Hashemian, Saeede

    2013-01-01

    We have analyzed the effect of external electric field on the zigzag (6,0) single-wall BC2N nanotube using density functional theory calculations. Analysis of the structural parameters indicates that the nanotube is resistant against the external electric field strengths. Analysis of the electronic structure of the nanotube indicates that the applied parallel electric field strengths have a much stronger interaction with the nanotube with respect to the transverse electric field strengths and the nanotube is easier to modulate by the applied parallel electric field. Our results show that the properties of the nanotube can be controlled by the proper external electric field for use in nano-electronic circuits.

  9. Power dissipated in a non-thermal atmospheric pressure plasma jet measured by miniaturized electrical probes

    Science.gov (United States)

    Golda, Judith; Schulz-von der Gathen, Volker

    2016-09-01

    Non-thermal atmospheric pressure plasma jets are used in bio-medicine, because they generate reactive species at a low gas temperature. Knowledge and control of plasma parameters is required for stable and reliable operation. Therefore, measuring dissipated power in these plasmas is necessary. However, this is challenging because the delivered sender power is often orders of magnitudes higher than the power dissipated in the discharge itself. To measure this dissipated power, we built miniaturized electrical probes directly attached to the jet device. We observed that the dissipated power is a more comprehensive parameter than the common parameter voltage: For example, gas temperature and emission line intensities rose exponentially with increasing voltage but linearly with increasing power. Our analyses further revealed that a substantial proportion of the dissipated power is transformed into heat. In conclusion, miniaturized electrical probes give a fundamental insight into the energy balance of atmospheric pressure plasmas. In the future, these probes can also be adapted to different types of atmospheric pressure plasmas. This work was supported by DFG within the frameworks of the Package Project PAK 816.

  10. Hybrid inversion method for equivalent electric charge of thunder cloud based on multi-station atmospheric electric field

    Institute of Scientific and Technical Information of China (English)

    XING; Hongyan; ZHANG; Qiang; JI; Xinyuan; XU; wei

    2015-01-01

    This article proposes the hybrid method to inverse the equivalent electric charge of thunder cloud based on the data of multi-station atmospheric electric field. Firstly,the method combines the genetic algorithm( GA) and New ton method through the mosaic hybrid structure. In addition,the thunder cloud equivalent charge is inversed based on the forw ard modeling results by giving the parameters of the thunder cloud charge structure. Then an ideal model is built to examine the performance compared to the nonlinear least squares method. Finally,a typical thunderstorms process in Nanjing is analyzed by Genetic-New ton algorithm with the help of weather radar. The results show the proposed method has the strong global searching capability so that the problem of initial value selection can be solved effectively,as well as gets the better inversion results. Furthermore,the mosaic hybrid structure can absorb the advantages of tw o algorithms better,and the inversion position is consistent with the strongest radar echo.The inversion results find the upper negative charge is small and can be ignored,w hich means the triple-polarity charge structure is relatively scientific,w hich could give some references to the research like lightning forecasting,location tracking.

  11. 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.

  12. 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

  13. 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.

  14. Experimental Device for Learning of Logical Circuit Design using Integrated Circuits

    OpenAIRE

    石橋, 孝昭

    2012-01-01

    This paper presents an experimental device for learning of logical circuit design using integrated circuits and breadboards. The experimental device can be made at a low cost and can be used for many subjects such as logical circuits, computer engineering, basic electricity, electrical circuits and electronic circuits. The proposed device is effective to learn the logical circuits than the usual lecture.

  15. 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.

  16. Studies in geophysics: The Earth's electrical environment

    Science.gov (United States)

    1986-01-01

    The Earth is electrified. Between the surface and the outer reaches of the atmosphere, there is a global circuit that is maintained by worldwide thunderstorm activity and by upper atmospheric dynamo processes. The highest voltages approach a billion volts and are generated within thunderclouds, where lightning is a visual display of the cloud's electrical nature. The largest currents in the circuit, approaching a million amperes, are associated with the aurora. Because there have been significant advances in understanding many of the component parts of the global electric circuit (lightning, cloud electrification, electrical processes in specific atmospheric regions, and telluric currents), a principal research challenge is to understand how these components interact to shape the global circuit. Increased basic understanding in this field has many potential practical applications, including lightning protection, the design of advanced aircraft and spacecraft, and improvements in weather prediction.

  17. Learning Electrical Circuits: The Effects of the 4C-ID Instructional Approach in the Acquisition and Transfer of Knowledge

    Directory of Open Access Journals (Sweden)

    Mario Melo

    2015-07-01

    Full Text Available This study was designed to investigate the effects of two instructional approaches (4C-ID versus conventional on learners’ knowledge-acquisition and learning transfer of the electrical circuits content in Physics. Participants were 129 9th graders from a secondary school in Lisbon, M = 14.3 years, SD = 0.54. The participants were divided in two groups: an experimental group constituted three intact classes (n = 78; and a control group constituted two intact classes (n = 51. The experimental group was taught using a digital learning environment designed with the 4C-ID model principles while the control group learned the same contents through a conventional method. We assessed the students’ performance (knowledge-acquisition and transfer, the perceived cognitive load, and the instructional efficiency. Results indicated that the experimental group performed significantly better than the control group on a knowledge-acquisition test and in a learning transfer test. They also perceived a less cognitive load in the transfer test and the learning environment developed with the 4C-ID model proved to be more instructional efficient than the conventional method.

  18. 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.

  19. An examination of AC/HVDC power circuits for interconnecting bulk wind generation with the electric grid

    Energy Technology Data Exchange (ETDEWEB)

    Ludois, D.; Venkataramanan, G. [Department of Electrical and Computer Engineering, University of Wisconsin-Madison 1415 Engineering Dr. Madison WI 53706 (United States)

    2010-06-15

    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 may be used by wind energy/bulk transmission developers for performing engineering trade-off studies. (author)

  20. Description of Self-efficacy and Initial Cognitive Abilities on the Students’ Physics Learning of the Direct Current Electrical Circuits

    Science.gov (United States)

    Zaenudin; Maknun, J.; Muslim

    2017-03-01

    This study aims to determine description of self –efficacy and initial cognitive abilities on the students of MAN 1 Bandung (senior high school) in learning physics on the subject of electrical circuits Direct Current (DC) before they get academy ask assigned in the classroom. From the results of this research can be used as a reference to provide appropriate measures for the advancement of student learning. The theory used in this research is the theory of Bandura. The design in this study using case study and data collection is done by tests and questionnaires, sampling techniques used by random sampling, the study was conducted on 10th grade students of MAN 1 Bandung by the amount of students 35 participants. The results of data analysis showed that the percentage of students who have moderate self-efficacy amounted to 67.05 %, and cognitive ability 50 %, this shows that the process of learning that takes place in school before that junior high school is not much scientific implement processes that provide students the opportunity to discover new things, then learning approaches of right is Problem Based Learning (PBL).

  1. Consistency and advantage of loop regularization method merging with Bjorken-Drell's analogy between Feynman diagrams and electrical circuits

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Da; Wu, Yue-Liang [Chinese Academy of Science, State Key Laboratory of Theoretical Physics (SKLTP), Kavli Institute for Theoretical Physics China (KITPC), Institute of Theoretical Physics, Beijing (China)

    2012-07-15

    The consistency of loop regularization (LORE) method is explored in multiloop calculations. A key concept of the LORE method is the introduction of irreducible loop integrals (ILIs) which are evaluated from the Feynman diagrams by adopting the Feynman parametrization and ultraviolet-divergence-preserving (UVDP) parametrization. It is then inevitable for the ILIs to encounter the divergences in the UVDP parameter space due to the generic overlapping divergences in the four-dimensional momentum space. By computing the so-called {alpha}{beta}{gamma} integrals arising from two-loop Feynman diagrams, we show how to deal with the divergences in the parameter space with the LORE method. By identifying the divergences in the UVDP parameter space to those in the subdiagrams, we arrive at the Bjorken-Drell analogy between Feynman diagrams and electrical circuits. The UVDP parameters are shown to correspond to the conductance or resistance in the electrical circuits, and the divergence in Feynman diagrams is ascribed to the infinite conductance or zero resistance. In particular, the sets of conditions required to eliminate the overlapping momentum integrals for obtaining the ILIs are found to be associated with the conservations of electric voltages, and the momentum conservations correspond to the conservations of electrical currents, which are known as the Kirchhoff laws in the electrical circuits analogy. As a practical application, we carry out a detailed calculation for one-loop and two-loop Feynman diagrams in the massive scalar {phi}{sup 4} theory, which enables us to obtain the well-known logarithmic running of the coupling constant and the consistent power-law running of the scalar mass at two-loop level. Especially, we present an explicit demonstration on the general procedure of applying the LORE method to the multiloop calculations of Feynman diagrams when merging with the advantage of Bjorken-Drell's circuit analogy. (orig.)

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

    Science.gov (United States)

    Silva, H. G.; Conceição, R.; Melgão, M.; Nicoll, K.; Mendes, P. B.; Tlemçani, M.; Reis, A. H.; Harrison, R. G.

    2014-11-01

    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 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.

  3. 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.

  4. A tomographic visualization of electric discharge sound fields in atmospheric pressure plasma using laser diffraction

    Science.gov (United States)

    Nakamiya, Toshiyuki; Mitsugi, Fumiaki; Iwasaki, Yoichiro; Ikegami, Tomoaki; Tsuda, Ryoichi; Sonoda, Yoshito; Danuta Stryczewska, Henryka

    2013-02-01

    The phase modulation of transparent gas can be detected using Fraunhofer diffraction technique, which we call optical wave microphone (OWM). The OWM is suitable for the detection of sonic wave from audible sound to ultrasonic wave. Because this technique has no influence on sound field or electric field during the measurement, we have applied it to the sound detection for the electric discharges. There is almost no research paper that uses the discharge sound to examine the electrical discharge phenomenon. Two-dimensional visualization of the sound field using the OWM is also possible when the computerized tomography (CT) is combined. In this work, coplanar dielectric barrier discharge sin different gases of Ar, N2, He were characterized via the OWM as well as applied voltage and discharge current. This is the first report to investigate the influence of the type of the atmospheric gas on the two-dimensional sound field distribution for the coplanar dielectric barrier discharge using the OWM with CT. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.

  5. 电路课程的历史、现状和前景%History, Status, and Prospects of the Electric Circuit Courses

    Institute of Scientific and Technical Information of China (English)

    龚绍文; 郑君里; 于歆杰

    2011-01-01

    电路课程是高等学校电工程和信息类专业,甚至其它专业的一门重要的专业基础课。该课程的历史悠久,许多内容已相当成熟。但由于电子技术和信息技术的飞速发展,本课程仍然需要更新与改革。关于“电路课程如何更新与改革”这一话题,全世界有关院校都在热烈讨论。本文试图从回顾电路理论的发展过程中,从我国电路课程的演变中,从国际上最新发展动向中及从我国和美国近期电路课程的比较中探寻电路课程改革的方向。%The electric circuit course is an important specialized basic course for electrical and information or even more disciplines. It has long history and most of its contents are mature. But with the rapid development of electronic and information technology, the course still needs updates and reformation. In this paper, the authors try to find the reformation direction for the course by reviewing the development procedure of the circuit theory, evolving of the electric circuit course in China, surveying the latest developments in the world, and comparing the electric circuit courses from China and USA.

  6. 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.

  7. 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.

  8. Atmospheric electric field effects of cosmic rays detected in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, L. X; Valdes-Galicia, J. F [Instituto de Geofisica, Universidad National Autonoma de Mexico, Mexico D.F(Mexico)

    2006-10-15

    We studied the possible effects of atmospheric electric fields, generated in thunderstorms, on the cosmic ray intensity detected at the Earth's surface by investigating the variations of the counting rates of the cosmic-ray nucleonic component, obtained from the neutron monitor installed in Mexico City, for thunderstorms during 1996 and 1997. These were years of minimum solar activity. We compare our experimental results with the general theory of cosmic ray meteorological effects by Dorman (1995). The observed intensity variation is about 0.2%. According to Dorman (1995), the effect should be between 0.27% and 0.81% on the counting rate of the neutron monitor when the atmospheric electric field intensities are around 100 to 300 Vcm-1.Our results show that either the electric field in Mexico City had less intensity than assumed by Dorman (1995), or the electric field is not uniform in time and height during the development of the thunderstorm. [Spanish] Estudiamos los posibles efectos de los campos electricos atmosfericos, generados en las tormentas electricas, sobre la intensidad de los rayos cosmicos detectados en la superficie terrestre, analizando las variaciones de las razones de conteo de la componente nucleonica de los rayos cosmicos, obtenidas por el monitor de neutrones instalado en la ciudad de Mexico, durante tormentas electricas ocurridas entre 1996 y 1997, anos del minimo solar. Comparamos nuestros resultados experimentales con la teoria general de los efectos meteorologicos en los rayos cosmicos, desarrollada por Dorman (1995). Se observo una variacion en la intensidad de alrededor de 0.2%. De acuerdo con Dorman (1995), el efecto puede estar entre 0.27 % y 0.81% en las razones de conteo del monitor de neutrones cuando las intensidades del campo electrico atmosferico se encuentran al rededor de 100 a 300 Vcm-1. Nuestros resultados muestran que los campos electricos en la ciudad de Mexico tuvieron menos intensidad que los campos electricos asumidos

  9. 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.

  10. Nonzero Temperature Squeezing of the Time-Dependent Harmonic Oscillator and the Applications to the Capacitive Coupled Electric Circuit

    Institute of Scientific and Technical Information of China (English)

    LIANG Mai-Lin; YUAN Bing

    2002-01-01

    A new way to calculate the nonzero temperature quantum fluctuations of the time-dependent harmonicoscillator is proposed and the properties of squeezing are exactly given. The method is applied to the capacitive coupledelectric circuit. It is explicitly shown that squeezing can appear and the squeezing parameters are related to the physicalquantities of the coupled circuit.

  11. 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.

  12. 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.

  13. Long-term changes in atmospheric electrical parameters observed at Nagycenk (Hungary and the UK observatories at Eskdalemuir and Kew

    Directory of Open Access Journals (Sweden)

    F. Märcz

    Full Text Available The Nagycenk Geophysical Observatory in Hungary (47° 38 ' N, 16° 43 ' E has made continuous measurements of the vertical atmospheric electric Potential Gradient (PG since 1962. Global signals have previously been identified in the Nagycenk PG data. A long-term (1920–1981 decrease has been discovered in the PG measured at the Eskdalemuir Observatory, Scotland (55° 19 ' N, 3° 12 ' W, suggesting that this represents a global change in the atmospheric electricity related to a decline in cosmic rays. A 40% decline in PG is shown here to have occurred at Nagycenk between 1962 and 2001, also consistent with changes in the air-Earth current measured at Kew (51° 28 ' N, 0° 19 ' W, London, 1966–1978. Comparison of the long-term PG measurements at both Eskdalemuir and Nagycenk gives further evidence to support the hypothesis of a global atmospheric electrical decline from the early twentieth century to the present time, as it is shown that local effects at Nagycenk are unlikely to have dominated the changes there.

    Key words. Meteorology and atmospheric dynamics (atmospheric electricity

  14. Transmission probabilities of rarefied flows in the application of atmosphere-breathing electric propulsion

    Science.gov (United States)

    Binder, T.; Boldini, P. C.; Romano, F.; Herdrich, G.; Fasoulas, S.

    2016-11-01

    Atmosphere-Breathing Electric Propulsion systems (ABEP) are currently investigated to utilize the residual atmosphere as propellant for drag-compensating thrusters on spacecraft in (very) low orbits. The key concept for an efficient intake of such a system is to feed a large fraction of the incoming flow to the thruster by a high transmission probability Θ for the inflow while Θ for the backflow should be as low as possible. This is the case for rarefied flows through tube-like structures of arbitrary cross section when assuming diffuse wall reflections inside and after these ducts, and entrance velocities u larger than thermal velocities vt h∝√{kBT /m } . The theory of transmission for free molecular flow through cylinders is well known for u = 0, but less research results are available for u > 0. In this paper, the desired theoretical characteristics of intakes for ABEP are pointed out, a short review of transmission probabilities is given, and results of Monte Carlo simulations concerning Θ are presented. Based on simple algebraic relations, an intake can be optimized in terms of collection efficiency by choosing optimal ducts. It is shown that Θ depends only on non-dimensional values of the duct geometry combined with vth and u. The simulation results of a complete exemplary ABEP configuration illustrate the influence of modeling quality in terms of inflow conditions and inter-particle collisions.

  15. 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...

  16. 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.

  17. Design of protection circuit for lithium battery used in electric bicycle%电动自行车锂电池组保护电路设计

    Institute of Scientific and Technical Information of China (English)

    许英杰; 孙郅佶; 李帆; 范贤光

    2012-01-01

    The lithium battery with superior performance is the development trend of the electric bicycle power, but needs a dedicated protection circuit to work with so as to ensure the safety and long-period operation. In this paper, a protection circuit board including S-8209A was designed for the lithium battery set with 4-parallel and 10-serial connection mode. It achieved the functions of overcharge protection, overdischarge protection, overcharge-overdischarge balance and overcurrent protection. The circuit has been already applied to the electric bikes with the lithium batteries.%为保证电动自行车锂电池组安全、长寿命的运行,需为其配备专用管理保护电路.为此,针对一款4并10串规格的锂电池组设计了一套保护电路板,采用S-8209A保护芯片,实现了过充电保护、过放电保护、电池充放电平衡、过电流保护、正常带载等功能,已被可靠应用于某款电动自行车的锂电池组中.

  18. 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.

  19. An influence of the petrol pump for the atmospheric electric field distribution in the surroundings of the vehicles

    Directory of Open Access Journals (Sweden)

    Milovanović Alenka

    2004-01-01

    Full Text Available In this paper the potential and electric field distribution in the surroundings of the cargo vehicles is approximately numerically determined, when they are exposed to the Atmospheric Electric Field (AEF, having uniform intensity and vertical polarization. The cases of the cargo vehicles either isolated or near by petrol pumps are observed. Several results of total induced charge and electrical moment of the vehicle including maps of equipotential and equienergetic curves are presented. The Equivalent Electrode Method (EEM is used to solve this problem.

  20. 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.

  1. 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

  2. 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 ...

  3. 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.

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

    Science.gov (United States)

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

    2012-01-01

    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 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.

  5. Electric currents in the solar atmosphere in the presence of magnetic null points

    Science.gov (United States)

    Carlo Santos, Jean; Büchner, Jörg; Otto, Antonius

    So far the role of magnetic null points in 3D reconnection was investigated mainly for the close vicinity of the null, with perturbations being applied at the nearby boundaries. In the solar atmosphere, however, electric currents are generated due to perturbations originating at the photosphere, far a way from coronal 3D nulls. We investigate the consequences of photospheric motion for the development of electric cur-rents in a coronal magnetic field configuration containing a null, located far away from the boundaries, and the influence of topological structures on their spatial distribution. We use a 3D resistive MHD code to investigate the consequences of photospheric plasma motion for the generation of currents in a coronal magnetic field containing a null. The plasma is consid-ered fully compressible and is initially in hydrostatic equilibrium. The initial magnetic field is current free (potential). Initially the photospheric plasma motion creates a magnetic field perturbation that propagates to the corona along the field lines at the local Alfvén speed. The shear Alfvenic wave pertur-e bation corresponds to a propagating current. The currents are mainly parallel to the magnetic field. The perturbations starting close to the foot points of the field lines that connect to the null eventually reach the vicinity of the null. Since the local Alfvén speed decreases as we approach the magnetic null point, the perturbations of the magnetic field never reach the null. Meanwhile, strong currents develop around the null point where the perturbations reach the intersection of two separatrices. On those regions, when there is an appropriate perturbation, a shear of the magnetic field is created in a length scale much smaller than the characteristic length scale of the system, generating a strong current channel.

  6. 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.)

  7. 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.

  8. Ice shedding from overhead electrical lines by mechanical breaking : a ductile model for viscoplastic behaviour of atmospheric ice

    Energy Technology Data Exchange (ETDEWEB)

    Eskandarian, M.

    2005-07-01

    The mechanical characteristics of power line components need improvement in order to avoid power failures during severe ice storms. Atmospheric icing of overhead power lines creates electrical and mechanical problems in the transmission network. The successful development of anti-icing and de-icing techniques requires good knowledge of the adherence and bulk strength characteristics of atmospheric ice. This study presented a model for viscoplastic behaviour of porous atmospheric ice in the ductile region. The model was then modified to consider the effects of cracking activities to predict the material behaviour in transition and brittle regions. The following general methodologies were followed in this research for describing the ductile behaviour of porous atmospheric ice: instantaneous elastic strain; delayed viscoelastic strain; and, permanent plastic strain. The scientific contributions of this study include a classification of atmospheric ice structure on power lines on the basis of its grain shape and c-axis orientation. This thesis also presented 3 computer codes in Maple Mathematical Program for determining the elastic moduli of various types of freshwater ice; a poroelastic model for modifying the elastic moduli of porous atmospheric ice; a cap-model plasticity for various types of porous atmospheric ice; new freshwater ice yield envelopes in ductile regions that take porosity into account by means of an elliptical moving cap; and a newly developed user-defined material subroutine for viscoplastic behaviour of atmospheric ice in ductile region including the poroelastic, viscoelastic, and cap-model plasticity.

  9. 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.

  10. 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.

  11. Modulation of urban atmospheric electric field measurements with the wind direction in Lisbon (Portugal)

    Science.gov (United States)

    Silva, H. G.; Matthews, J. C.; Conceição, R.; Wright, M. D.; Pereira, S. N.; Reis, A. H.; Shallcross, D. E.

    2015-10-01

    Atmospheric electric field measurements (potential gradient, PG) were retrieved in the urban environment of the city of Lisbon (Portugal). The measurements were performed with a Benndorf electrograph at the Portela Meteorological station in the suburbs of the city (NE from the centre). The period of 1980 to 1990 is considered here. According to wind direction, different content and types of ions and aerosols arrive at the measurement site causing significant variations to the PG. To the south there are significant pollution sources while to the north such sources are scarcer. The Iberian Peninsula is found east of the station and the Atlantic Ocean covers the western sector, Wind directions are divided in four sectors: i) NW: 270° ≤ θ ≤ 360° ii) NE: 0 ≤ θ ≤ 90° iii) SE: 90 ≤ θ ≤ 180° iv) SW: 180° ≤ θ ≤ 270°. Analysis of weekly cycle, caused by anthropogenic pollution related with urban activity, was undertaken for each wind sector. NW sector has been shown to be less affected by this cycle, which is attributed to the effect of marine air. The daily variation of NE sector for weekends reveals a similar behaviour to the Carnegie curve, which corresponds to a clean air daily variation of PG, following universal time, independent of measurement site.

  12. Optimizing the electrical excitation of an atmospheric pressure plasma advanced oxidation process.

    Science.gov (United States)

    Olszewski, P; Li, J F; Liu, D X; Walsh, J L

    2014-08-30

    The impact of pulse-modulated generation of atmospheric pressure plasma on the efficiency of organic dye degradation has been investigated. Aqueous samples of methyl orange were exposed to low temperature air plasma and the degradation efficiency was determined by absorbance spectroscopy. The plasma was driven at a constant frequency of 35kHz with a duty cycle of 25%, 50%, 75% and 100%. Relative concentrations of dissolved nitrogen oxides, pH, conductivity and the time evolution of gas phase ozone were measured to identify key parameters responsible for the changes observed in degradation efficiency. The results indicate that pulse modulation significantly improved dye degradation efficiency, with a plasma pulsed at 25% duty showing a two-fold enhancement. Additionally, pulse modulation led to a reduction in the amount of nitrate contamination added to the solution by the plasma. The results clearly demonstrate that optimization of the electrical excitation of the plasma can enhance both degradation efficiency and the final water quality.

  13. Fundamental study on stabilizing control method for electric power system using distributed circuit model; Bunpu teisu kairo moderu ni yoru denryoku keito doyo mogi to anteika seigyo ni kansuru kisoteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, A.; Kawasaki, K. [Shikoku Electric Power Co., Inc., Kagawa (Japan); Takigawa, K. [Shikoku Reserch Institute Inc., Kagawa (Japan); Ariyoshi, H. [Ehime University, Ehime (Japan)

    1997-06-20

    To grasp the electric power system disturbance, the detailed simulation model of the electric power system is applied, however, it is not so easy to grasp the disturbance characteristics of a large scale electric power system in the broader aspects. On the other hand, from a shut down test of generator and electric load in the electric power system, it is well known that the power disturbance is transmitted from the test point to the other points with constant delay time. The phenomena shows that the electric power system has a similar dynamic characteristic to the distributed constant circuit. In this paper, the electric power system is expressed with the distributed constant circuit so that the main disturbance characteristics are obtained without difficulty. Moreover, the possibility of suppressing the disturbance is discussed by employing active sink method, and distributed constant circuit model and lumped constant circuit model are compared with the viewpoint of eigenvalue and its propriety is showed. Further, as an example, active sink method, the effectiveness of distributed constant model in the suppressing control of electric power system disturbance, is showed. 7 refs., 12 figs., 1 tab.

  14. A comparative study on orographic and latitudinal features of global atmospheric electrical parameters over different places at three Asian countries

    Science.gov (United States)

    Kumar, A.; Singh, D.

    2014-03-01

    Some global atmospheric electrical parameters like atmospheric conductivity, air-earth current density, electric field, atmospheric potential, etc. have been estimated over different places of India, China and Korea of Asian continent. These calculations have been made by assuming fair weather conditions and taking into account the small scale (0.5° grid in latitude and longitude) orographic and latitudinal effects. Mean values of conductivity and air-earth current density over various places of India, China and Korea have been found to be 5.97 × 10-14, 5.46 × 10-14, 2.82 × 10-14 S m-1 and 6.58 × 10-12, 6.04 × 10-12, 3.16 × 10-12 A m-2, respectively whereas average electric field and atmospheric potential over these places are 110.9, 110.81, 112.08 V m-1 and 269.52, 272.90, 286.64 kV, respectively. It has been found from the results that latitudinal variation is very much smaller than orographic variation over these three countries of Asian region.

  15. Electric Circuit Model for the Aerodynamic Performance Analysis of a Three-Blade Darrieus-Type Vertical Axis Wind Turbine: The Tchakoua Model

    Directory of Open Access Journals (Sweden)

    Pierre Tchakoua

    2016-10-01

    Full Text Available The complex and unsteady aerodynamics of vertical axis wind turbines (VAWTs pose significant challenges for simulation tools. Recently, significant research efforts have focused on the development of new methods for analysing and optimising the aerodynamic performance of VAWTs. This paper presents an electric circuit model for Darrieus-type vertical axis wind turbine (DT-VAWT rotors. The novel Tchakoua model is based on the mechanical description given by the Paraschivoiu double-multiple streamtube model using a mechanical‑electrical analogy. Model simulations were conducted using MATLAB for a three-bladed rotor architecture, characterized by a NACA0012 profile, an average Reynolds number of 40,000 for the blade and a tip speed ratio of 5. The results obtained show strong agreement with findings from both aerodynamic and computational fluid dynamics (CFD models in the literature.

  16. Flip-flop logic circuit based on fully solution-processed organic thin film transistor devices with reduced variations in electrical performance

    Science.gov (United States)

    Takeda, Yasunori; Yoshimura, Yudai; Adib, Faiz Adi Ezarudin Bin; Kumaki, Daisuke; Fukuda, Kenjiro; Tokito, Shizuo

    2015-04-01

    Organic reset-set (RS) flip-flop logic circuits based on pseudo-CMOS inverters have been fabricated using full solution processing at a relatively low process temperatures of 150 °C or less. The work function for printed silver electrodes was increased from 4.7 to 5.4 eV through surface modification with a self-assembled monolayer (SAM) material. A bottom-gate, bottom-contact organic thin-film transistor (OTFT) device using a solution-processable small-molecular semiconductor material exhibited field-effect mobility of 0.40 cm2 V-1 s-1 in the saturation region and a threshold voltage (VTH) of -2.4 V in ambient air operation conditions. In order to reduce the variations in mobility and VTH, we designed a circuit with six transistors arranged in parallel, in order to average out their electrical characteristics. As a result, we have succeeded in reducing these variations without changing the absolute values of the mobility and VTH. The fabricated RS flip-flop circuits were functioned well and exhibited short delay times of 3.5 ms at a supply voltage of 20 V.

  17. Bridge Wire Electric Ignition Drive Circuits Design%桥丝电点火器的驱动电路设计∗

    Institute of Scientific and Technical Information of China (English)

    张宪国; 曹红松; 赵捍东; 白松

    2015-01-01

    Pulse jet engines are often ignited by gunpowder wrapped bridge wire electric igniter and widely used in aircraft attitude control. The electric igniter needs short-pulse current driving for rapid initiation. In this paper,opto-isolated constant current source and capacitor discharge mode driving circuits are designed for the demand of micro-bridge wire electric igniter. Two kinds of detonating circuit designs implemente the ignition driving of brige wire e-lectric igniter wtih resistance fluctuations. The constant current source mode is capable of long storage life,compact spatial structure and high safety, and the reservoir capacitor mode demonstrates high energy efficiency and fast-acting for quick initiation. Two methods provide reference designs for the pulse jet engines of different engineering requirements.%用于飞行器姿态控制的脉喷发动机常采用火药包裹的桥丝电点火器进行点火,电点火器需要短时脉冲电流驱动。本文针对微小型桥丝电点火器驱动需求,设计了光耦隔离恒流源方式及电容储能脉冲放电驱动电路,均实现了对阻值波动桥丝电点火器的点火驱动。试验证明,光耦隔离恒流源方式可靠性高,安全稳定,电容储能放电方式效率高、作用迅速。该两种设计方法可为脉喷发动机的工程实践提供参考。

  18. 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

  19. 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.

    Science.gov (United States)

    Potvin, Patrice; Turmel, Elaine; Masson, Steve

    2014-01-01

    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 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.

  20. Analysis of MIS equivalent electrical circuit of Au/Pd/Ti-SiO2-GaAs structure based on DLTS measurements

    Science.gov (United States)

    Kochowski, S.; Drewniak, Ł.; Nitsch, K.; Paszkiewicz, R.; Paszkiewicz, B.

    2013-08-01

    In this paper MIS equivalent electrical circuit of Au/Pd/Ti-SiO2-GaAs has been analyzed by a comparison of the results obtained from admittance and DLTS spectroscopy. Two groups of peaks with different magnitude and different gate voltage dependence have been observed in DLTS and admittance spectra. Based on the analysis of the peaks behavior, it has been concluded that they are associated with the response of bulk traps and interface states, respectively. In order to characterize bulk traps and interface states responsible for the occurrence of two groups of peaks in normalized conductance spectra we have used the equivalent circuit with two CPE-R branches. The time constant values estimated for both peaks from admittance analysis have been compared with the time constant determined from DLTS analysis. Some discrepancies have been noted between the time constants obtained for interface states whereas the time constants for bulk traps were compatible. It has been also demonstrated that when conductance peaks overlap, the admittance experimental data can be fitted by the equivalent electrical model with only one CPE-R branch. However, in this case incomplete information about the analyzed process has been obtained despite the fact that all model validity criteria can be fulfilled and the model seems to be correct.

  1. Identification and characterization of the atmospheric emission of polychlorinated naphthalenes from electric arc furnaces.

    Science.gov (United States)

    Liu, Guorui; Zheng, Minghui; Du, Bing; Nie, Zhiqiang; Zhang, Bing; Hu, Jicheng; Xiao, Ke

    2012-09-01

    Electric arc furnaces (EAF) are well recognized as significant sources of dioxins. EAFs have also been speculated to be sources of polychlorinated naphthalenes (PCNs) due to the close correlation between dioxin and PCN formation. However, assessment on PCN emissions from EAFs has not been carried out. The primary aim of this preliminary study is to identify and characterize the atmospheric emission of PCNs from EAFs. In this preliminary study, stack gas samples from two typical EAFs with different scales (EAF-1, 160 t batch(-1); and EAF-2, 60 t batch(-1)) were collected by automatic isokinetic sampling technique, and PCN congeners in samples were analyzed by isotope dilution high-resolution gas chromatography combined with high-resolution mass spectrometry method. Emission concentrations of PCNs were 458 and 1,099 ng m(-3) for EAF-1 and EAF-2, respectively. The emission factors of PCNs to air were 21.6 and 30.1 ng toxic equivalent t(-1) for EAF-1 and EAF-2, respectively, which suggested that EAF is an important source of PCN release. With regard to the characteristics of PCNs from EAFs, lower chlorinated homologues were dominant. The PCN congeners comprised of CN27/30, CN52/60, CN66/67, and CN73 were the most abundant congeners for tetra-, penta-, hexa-, and hepta-chlorinated homologues, respectively. EAFs were identified to be an important PCN source, and the obtained data are useful for developing a PCN inventory. The congener profiles of PCNs presented here might provide helpful information for identifying the specific sources of PCNs emitted from EAFs.

  2. 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

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

    OpenAIRE

    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...

  4. 依据标准探讨机床电气回路保护技术及其运用%Protection Technology of Machine Electrical Circuit and Its Practical Applications Based on the Relevant In-dustry Standards

    Institute of Scientific and Technical Information of China (English)

    孙伟; 马永青

    2015-01-01

    Machine tools' electrical design , installation and usage are related to the electrical circuit choosing , the specifications specify-ing of cables and circuit breaker and the technical conditions of electri-cal components etc . When the machine appears electrically abnormal or operating failure , the main work is speculating the failure through ana-lyzing the protection technology of electrical circuit . This paper is to explore the protection technology of machine tools' electrical circuit and its practical applications based on the relevant national and corporate industry standards .%机床的电气设计、安装与使用一定会涉及到电气回路的选择、电缆及断路器的规格指定、电气元器件的技术条件等等.而当机床出现电气装置异常或运转失效时,也会以分析电气回路的保护技术为主来推测故障.本文依据相关的国家及企业行业标准来探讨机床电气回路的保护技术和应用.

  5. A diurnal study of the electrical structure of the equatorial middle atmosphere

    Science.gov (United States)

    Croskey, C. L.; Hale, L. C.; Mitchell, J. D.; Muha, D.; Maynard, N. C.

    1985-10-01

    Electrical parameters measured from 115 km down to below 20 km during the Project Condor campaign at the Punta Lobos Rocket Range near Lima, Peru, are presented. Ten rocket-launched payloads measured electrical conductivity. A strong diurnal influence due to solar ultraviolet radiation is shown. Nine of the payloads also measured electric fields. No large mesospheric vertical electric fields are found in the data. A calculation of the dc global conduction current density at 18 km is smaller than previously measured at low latitudes and does not show the conventional diurnal variation.

  6. 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.

  7. 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.

  8. 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.

  9. S. Miller’s Experiments in Modelling of Non-Equilibrium Conditions with Gas Electric Discharge Simulating Primary Atmosphere

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov

    2015-12-01

    Full Text Available In this paper are submited data on the possibility of applying the coronal gas discharge effect (CGDE in modeling non-equilibrium conditions with gas electric discharge simulating conditions occurying in the primary atmosphere (electric sparks, lightning imitating S. Miller’s experiments. The physical basis and technique of visualization of gas discharge (GD glowing of water drops in alternating electric fields of high electrical voltage (5–30 kV and frequency (10–150 kHz, as well as the possible electrosynthesis of organic molecules from a mixture of inorganic substances as hydrogen (H2, methane (CH4, ammonia (NH3 and carbon monoxide (CO in aqueous solutions of water exposed under the electrical discharge, UV-radiation and thermal heating to t = +100 0C were examined. The colour coronal spectral gas discharge analysis was applied for investigation of water samples of various origin, the samples of hot mineral, sea and mountain water obtained from various water sources of Bulgaria.

  10. 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

  11. 30 CFR 56.6402 - Deenergized circuits near detonators.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Deenergized circuits near detonators. 56.6402... Electric Blasting § 56.6402 Deenergized circuits near detonators. Electrical distribution circuits within 50 feet of electric detonators at the blast site shall be deenergized. Such circuits need not...

  12. 乒乓球捡球机电气控制线路设计%Design of Electrical Control Circuit of Table Tennis Picking Machine

    Institute of Scientific and Technical Information of China (English)

    夏春风; 朱文伟; 高卫群; 马燕平; 王治国

    2016-01-01

    为解决乒乓球训练场所乒乓球的捡拾问题,设计了一种基于PLC和触摸屏的电气控制线路。该电气控制线路应用于乒乓球捡球机,利用PLC和触摸屏程序控制捡球机中的离心风机,离心风机产生的吸力吸取散落于地的乒乓球而实现自动捡球。捡球机实物模型性能测试表明,该捡球机捡球效果良好,平均每分钟捡球可达86个,此为更多捡球机的开发提供了借鉴和参考。%In order to solve the problem of table tennis picking in the table tennis court, an electrical control circuit based on PLC and touch screen was designed. The electrical control circuit was used for the table tennis picking machines. The table tennis balls scattered on the ground could be automatically picked up by a centrifugal fan in the table tennis picking machines. The centrifugal fan was controlled by PLC and touch screen program.The performance testing on the practical model of picking machine shows that the table tennis picking machines works well and average picks up table tennis up to 86 per minute,which provide reference for development of other moretypes of ball picking robots.

  13. Reflection on solutions in the form of refutation texts versus problem solving: the case of 8th graders studying simple electric circuits

    Science.gov (United States)

    Safadi, Rafi'; Safadi, Ekhlass; Meidav, Meir

    2017-01-01

    This study compared students’ learning in troubleshooting and problem solving activities. The troubleshooting activities provided students with solutions to conceptual problems in the form of refutation texts; namely, solutions that portray common misconceptions, refute them, and then present the accepted scientific ideas. They required students to individually diagnose these solutions; that is, to identify the erroneous and correct parts of the solutions and explain in what sense they differed, and later share their work in whole class discussions. The problem solving activities required the students to individually solve these same problems, and later share their work in whole class discussions. We compared the impact of the individual work stage in the troubleshooting and problem solving activities on promoting argumentation in the subsequent class discussions, and the effects of these activities on students’ engagement in self-repair processes; namely, in learning processes that allowed the students to self-repair their misconceptions, and by extension on advancing their conceptual knowledge. Two 8th grade classes studying simple electric circuits with the same teacher took part. One class (28 students) carried out four troubleshooting activities and the other (31 students) four problem solving activities. These activities were interwoven into a twelve lesson unit on simple electric circuits that was spread over a period of 2 months. The impact of the troubleshooting activities on students’ conceptual knowledge was significantly higher than that of the problem solving activities. This result is consistent with the finding that the troubleshooting activities engaged students in self-repair processes whereas the problem solving activities did not. The results also indicated that diagnosing solutions to conceptual problems in the form of refutation texts, as opposed to solving these same problems, apparently triggered argumentation in subsequent class

  14. Circuital characteristics and radiation properties of an UWB electric-magnetic planar antenna for Ku-band applications

    NARCIS (Netherlands)

    Haider, S.N.; Caratelli, D.; Yarovoy, A.G.

    2013-01-01

    A planar, directive antenna with large fractional bandwidth is introduced in this paper. A detailed discussion on the proposed antenna topology and its architecture is reported. The proposed element is a combination of a patch and a loop radiator. A proper combination of the electric field radiator

  15. Hydrogen influence on the electrical and optical properties of ZnO thin films grown under different atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Lorite, I., E-mail: lorite@physik.uni-leipzig; Wasik, J.; Michalsky, T.; Schmidt-Grund, R.; Esquinazi, P.

    2014-04-01

    In this work we studied the changes of the electrical and optical properties after hydrogen plasma treatment of polycrystalline ZnO thin films grown under different atmosphere conditions. The obtained results show that the gas used during the growth process plays an important role in the way hydrogen is incorporated in the films. The hydrogen doping can produce radiative and non-radiative defects that reduce the UV emission in ZnO films grown in oxygen atmosphere but it passivates defects created when the films are grown in nitrogen atmosphere. Impedance spectroscopy measurements show that these effects are related to regions where hydrogen is mostly located, either at the grain cores or boundaries. We discuss how hydrogen strongly influences the initial semiconducting behavior of the ZnO thin films. - Highlights: • Effectiveness of hydrogen treatment depends on the thin film growth conditions. • There is no detection of secondary phases after treatment by IS. • Hydrogen incorporation changes optical and electrical ZnO properties.

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

    Science.gov (United States)

    Sulaeman, M. Y.; Widita, R.

    2014-09-01

    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.

  17. 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.

  18. 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...

  19. Computing Electric Currents in the Martian Ionosphere Using Magnetometer Data from the Mars Atmospheric Volatile EvolutioN (MAVEN) Spacecraft

    Science.gov (United States)

    Fogle, A. L.

    2015-12-01

    Mars does not have a global magnetic field like Earth does. However, due to solar wind and interplanetary magnetic field (IMF) interactions, electric currents are induced which create an induced magnetosphere. As MAVEN passes through the ionosphere of Mars, the magnetometer on board continuously measures the induced magnetic field in the ionosphere. Using Ampere's Law (∇ × B = µ0j) along with these measurements of the induced magnetic field, we can quantify the electric currents in the ionosphere. We are particularly interested in magnetic field profiles that have a radial component that is less than or equal to 5 nanoteslas in magnitude. By only using measurements where the radial component of the magnetic field satisfies the aforementioned condition and assuming that there are no horizontal gradients in the magnetic field, we will calculate horizontal currents in the ionosphere. Using these calculated currents, we will analyze altitudinal variations in magnitude and direction of the currents. Measuring these horizontal currents can give us insights into how the solar wind and IMF can affect the upper atmosphere of Mars. For example, induced electric currents can cause Joule heating in the atmosphere, which can potentially modify its neutral dynamics.

  20. X-ray emission from a nanosecond-pulse discharge in an inhomogeneous electric field at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Cheng; Shao Tao; Ren Chengyan; Zhang Dongdong [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Tarasenko, Victor; Kostyrya, Igor D. [Institute of High Current Electronics, Russian Academy of Science, Tomsk 634055 (Russian Federation); Ma Hao [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yan Ping [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

    2012-12-15

    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.

  1. The formation of strong electric fields and volumetric charges in the Solar atmosphere

    CERN Document Server

    Sarsembaeva, A T; Kato, K

    2012-01-01

    The processes occurring in the solar atmosphere are diverse and depend on many important factors. For example, from magnetic fields, their sudden changes, from emissions of substance from the depths of the Sun, distribution of shock waves and plasma jets, etc. The paper describes the model of formation of the charged volumes of gas in solar atmosphere, which is called solar "storm clouds" by analogy with terrestrial storm clouds. The model will be based on the theory ionization equilibrium and the Saha equation.

  2. Algebraic circuits

    CERN Document Server

    Lloris Ruiz, Antonio; Parrilla Roure, Luis; García Ríos, Antonio

    2014-01-01

    This book presents a complete and accurate study of algebraic circuits, digital circuits whose performance can be associated with any algebraic structure. The authors distinguish between basic algebraic circuits, such as Linear Feedback Shift Registers (LFSRs) and cellular automata, and algebraic circuits, such as finite fields or Galois fields. The book includes a comprehensive review of representation systems, of arithmetic circuits implementing basic and more complex operations, and of the residue number systems (RNS). It presents a study of basic algebraic circuits such as LFSRs and cellular automata as well as a study of circuits related to Galois fields, including two real cryptographic applications of Galois fields.

  3. Mass and elemental distributions of atmospheric particles nearby blast furnace and electric arc furnace operated industrial areas in Australia.

    Science.gov (United States)

    Mohiuddin, Kazi; Strezov, Vladimir; Nelson, Peter F; Stelcer, Eduard; Evans, Tim

    2014-07-15

    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.

  4. 30 CFR 56.6403 - Branch circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Branch circuits. 56.6403 Section 56.6403... Blasting § 56.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits, each branch shall be equipped with a safety switch or equivalent method to isolate the circuits to be used....

  5. The influence of electrode configuration on light emission profiles and electrical characteristics of an atmospheric-pressure plasma jet

    Science.gov (United States)

    Maletić, Dejan; Puač, Nevena; Malović, Gordana; Đorđević, Antonije; Petrović, Zoran Lj

    2017-04-01

    In this paper we focus on the influence of the type of electrodes, their dimensions and inter-electrode gap on the formation of a helium plasma jet. Plasma emission profiles are recorded by an ICCD camera simultaneously with volt–ampere characteristics for three different copper electrode configurations. The delivered power was up to 6.5 W, but it may be set and controlled to 0.1 W. This study shows how the electrode configuration shapes and controls temporal and spatial plasma development as well as electrical characteristics of an atmospheric pressure plasma jet. It is shown that, in our system, the width of the grounded electrode has no significant influence on the formation and properties of pulsed atmospheric-pressure streamers (PAPS) outside the tube, while the width of the powered electrode is crucial in their formation.

  6. 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..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates....

  7. An interpretation of induced electric currents in long pipelines caused by natural geomagnetic sources of the upper atmosphere

    Science.gov (United States)

    Campbell, W.H.

    1986-01-01

    Electric currents in long pipelines can contribute to corrosion effects that limit the pipe's lifetime. One cause of such electric currents is the geomagnetic field variations that have sources in the Earth's upper atmosphere. Knowledge of the general behavior of the sources allows a prediction of the occurrence times, favorable locations for the pipeline effects, and long-term projections of corrosion contributions. The source spectral characteristics, the Earth's conductivity profile, and a corrosion-frequency dependence limit the period range of the natural field changes that affect the pipe. The corrosion contribution by induced currents from geomagnetic sources should be evaluated for pipelines that are located at high and at equatorial latitudes. At midlatitude locations, the times of these natural current maxima should be avoided for the necessary accurate monitoring of the pipe-to-soil potential. ?? 1986 D. Reidel Publishing Company.

  8. Experimental Research on Atmospheric Electric Field and Extensive Air Shower Particle Increasing During Thunderstorms with ARGO-YBJ

    Institute of Scientific and Technical Information of China (English)

    XU Bin; ZHANG Ying; JIA Huan-Yu

    2008-01-01

    From April lst to August 14th, 2006, thunderstorms had been recorded at Yangbajing Cosmic Ray Observatory by ARGO-YBJ experiment. This paper analyzed the correlation between atmospheric electric field (AEF) and "scaler mode" counting rate during thunderstorm. Counting rates of multiplicities n = 1,2 were found to have a large increase ( from 1.02% to 9.03% ), while there was few or no changes in those of multiplicities n =3 and n≥4 during the thunderstorms. The counts of different multiplicities had different feedbacks on the violent change of AEF, which showed that their energy and most components were distinguishing.

  9. 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.

  10. Printed Circuit Board Surface Finish and Effects of Chloride Contamination, Electric Field, and Humidity on Corrosion Reliability

    Science.gov (United States)

    Conseil-Gudla, Hélène; Jellesen, Morten S.; Ambat, Rajan

    2017-02-01

    Corrosion reliability is a serious issue today for electronic devices, components, and printed circuit boards (PCBs) due to factors such as miniaturization, globalized manufacturing practices which can lead to process-related residues, and global usage effects such as bias voltage and unpredictable user environments. The investigation reported in this paper focuses on understanding the synergistic effect of such parameters, namely contamination, humidity, PCB surface finish, pitch distance, and potential bias on leakage current under different humidity levels, and electrochemical migration probability under condensing conditions. Leakage currents were measured on interdigitated comb test patterns with three different types of surface finish typically used in the electronics industry, namely gold, copper, and tin. Susceptibility to electrochemical migration was studied under droplet conditions. The level of base leakage current (BLC) was similar for the different surface finishes and NaCl contamination levels up to relative humidity (RH) of 65%. A significant increase in leakage current was found for comb patterns contaminated with NaCl above 70% to 75% RH, close to the deliquescent RH of NaCl. Droplet tests on Cu comb patterns with varying pitch size showed that the initial BLC before dendrite formation increased with increasing NaCl contamination level, whereas electrochemical migration and the frequency of dendrite formation increased with bias voltage. The effect of different surface finishes on leakage current under humid conditions was not very prominent.

  11. 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.

  12. Printed Circuit Board Surface Finish and Effects of Chloride Contamination, Electric Field, and Humidity on Corrosion Reliability

    Science.gov (United States)

    Conseil-Gudla, Hélène; Jellesen, Morten S.; Ambat, Rajan

    2016-10-01

    Corrosion reliability is a serious issue today for electronic devices, components, and printed circuit boards (PCBs) due to factors such as miniaturization, globalized manufacturing practices which can lead to process-related residues, and global usage effects such as bias voltage and unpredictable user environments. The investigation reported in this paper focuses on understanding the synergistic effect of such parameters, namely contamination, humidity, PCB surface finish, pitch distance, and potential bias on leakage current under different humidity levels, and electrochemical migration probability under condensing conditions. Leakage currents were measured on interdigitated comb test patterns with three different types of surface finish typically used in the electronics industry, namely gold, copper, and tin. Susceptibility to electrochemical migration was studied under droplet conditions. The level of base leakage current (BLC) was similar for the different surface finishes and NaCl contamination levels up to relative humidity (RH) of 65%. A significant increase in leakage current was found for comb patterns contaminated with NaCl above 70% to 75% RH, close to the deliquescent RH of NaCl. Droplet tests on Cu comb patterns with varying pitch size showed that the initial BLC before dendrite formation increased with increasing NaCl contamination level, whereas electrochemical migration and the frequency of dendrite formation increased with bias voltage. The effect of different surface finishes on leakage current under humid conditions was not very prominent.

  13. 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...

  14. 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

  15. Summary of Intrinsic Safety Electric Circuit Technology%本质安全电路技术综述

    Institute of Scientific and Technical Information of China (English)

    于月森; 谢冬莹; 李世光; 伍小杰

    2011-01-01

    简要回顾本安理论及相关标准的发展历史;介绍从不同角度提出的非爆炸性本安判定理论;探讨本安电源实现保护电路和提高功率的方法;在阐明电流变化率对本安性能产生的影响后,提出与此相适应的新评价方法和新火花试验装置需要进一步研究;给出不同类型的本安现场总线结构,总结现有本安现场总线系统冗余电源的结构;最后,展望本安理论与技术相关的研究热点和研究方向.%The paper had a brief review on the development history of the intrinsic safe theory and the related standards and introduced the assessment theory of the non explosion intrinsic safe from the different aspects. The paper discussed the intrinsic safe power applied to protect the circuit and to improve the power. After the statement on the current variation rate affected to the intrinsic performances, the paper provided the related new assessment method and the new spark test device needed to be further studied. The different type intrinsic safe site bus structure was provided. The paper summarized the redundant power structure of the available intrinsic safe site bus system. In the final, the paper had an outlook on the related study focuses and the study orientation of the intrinsic safe theory and technology.

  16. 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.

  17. Effect of oxygen on the electrical conductivity of some metal oxides in inert and reducing atmospheres at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T.A.; Firth, J.G.; Mann, B.

    1985-12-01

    An investigation has been carried out on the electrical behaviour at 900/sup 0/C of some ceramic oxides as a function of oxygen pressure. Measurements have been made in an inert (N/sub 2/) atmosphere and in an inert atmosphere containing reducing gases (CO, H/sub 2/ and CH/sub 4/). The oxides for which data are presented are Cr/sub 2/O/sub 3/, Nb/sub 2/O/sub 5/, CeO/sub 2/, ThO/sub 2/ and Ga/sub 2/O/sub 3/. The factors affecting the electrical conductivities of these materials are briefly reviewed. The conductivities of Cr/sub 2/O/sub 3/, Nb/sub 2/O/sub 5/ and CeO/sub 2/ showed a switch-like behaviour at the stoichiometric mixture of oxygen and reducing gas. Ga/sub 2/O/sub 3/ and ThO/sub 2/ do not exhibit this type of behaviour, the conductivities changing monotonically with increasing oxygen pressure. The possible reasons for this difference in behaviour are discussed. Data are also presented showing the behaviour of a sensor based on Ga/sub 2/O/sub 3/ in a vehicle exhaust. This shows its potential as a means of monitoring exhaust emissions with a view to controlling the air/fuel ratios at around the stoichiometric mixture.

  18. 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。

  19. Fire protection electrical engineering

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jung Min

    2000-03-15

    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.

  20. 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.

  1. Characteristics of meter-scale surface electrical discharge propagating along water surface at atmospheric pressure

    Science.gov (United States)

    Hoffer, Petr; Sugiyama, Yuki; Hosseini, S. Hamid R.; Akiyama, Hidenori; Lukes, Petr; Akiyama, Masahiro

    2016-10-01

    This paper reports physical characteristics of water surface discharges. Discharges were produced by metal needle-to-water surface geometry, with the needle electrode driven by 47 kV (FWHM) positive voltage pulses of 2 µs duration. Propagation of discharges along the water surface was confined between glass plates with 2 mm separation. This allowed generation of highly reproducible 634 mm-long plasma filaments. Experiments were performed using different atmospheres: air, N2, and O2, each at atmospheric pressure. Time- and spatially-resolved spectroscopic measurements revealed that early spectra of discharges in air and nitrogen atmospheres were dominated by N2 2nd positive system. N2 radiation disappeared after approx. 150 ns, replaced by emissions from atomic hydrogen. Spectra of discharges in O2 atmosphere were dominated by emissions from atomic oxygen. Time- and spatially-resolved emission spectra were used to determine temperatures in plasma. Atomic hydrogen emissions showed excitation temperature of discharges in air to be about 2  ×  104 K. Electron number densities determined by Stark broadening of the hydrogen H β line reached a maximum value of ~1018 cm-3 just after plasma initiation. Electron number densities and temperatures depended only slightly on distance from needle electrode, indicating formation of high conductivity leader channels. Direct observation of discharges by high speed camera showed that the average leader head propagation speed was 412 km · s-1, which is substantially higher value than that observed in experiments with shorter streamers driven by lower voltages.

  2. Push-pull type of high-frequency inverter with voltage controllability by using short-circuit mode and its application to high-frequency lighting circuit of electric-discharge lamp. Tanraku modo wo mochiita kaseigyo push pull koshuha inverter to hoden ranpu koshuha tento kairo eno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Funabiki, S.; Komatsubara, H. (Okayama Univ., Okayama (Japan)); Kanbara, T.; Tanigawa, K. (Matsushita Electric Works Ltd., Osaka (Japan))

    1994-04-20

    In recent years, in order to compact the inverter and to make high-function of the inverter used in electric-discharge lamp, the electronic-inverter with high-frequency is improved. There are some problems in the high-frequency inverter that surge and noise occur when switch loss increases and voltage is intermitted abruptly that is caused by the over-voltage at the time of turn-on and turn-off. In this paper, as for voltage resonant type of push-pull high-frequency inverter circuit, a control method using a short-circuit mode actively that turns 2 switches on at the same time in power output control is proposed and the theoretical analysis and practical experiments are carried out. Then, the application of the control method to electric-discharge lamp is studied. As for the comparison of the steady-state characteristics of theoretical analysis with the experiment data, the result shows the both agrees well with each other even though there are some errors caused by the parasitic capacity of the MOSFET being a switch of the circuit. And, a stable output control in a wide range is achieved based on the experiments of the lighting circuit of the electric-discharge lamp. 7 refs., 7 figs., 3 tabs.

  3. 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

  4. Application of Bird Repellent Device in Electrical Circuit Design%驱鸟器在电力线路设计中的应用

    Institute of Scientific and Technical Information of China (English)

    李慧明; 闫石

    2016-01-01

    In recent years, as the ceaseless improvement of ecological environment, high voltage transmission line tripping caused by birds often happens.Prevent birds violation,en-suring normal operation of transmission lines is an important content should be included in the power line design work. In the practical power circuit design should be based on the geo-graphical environment of the line, the distribution of birds and project investment budget, reasonably choose bird repellent device type and installation section, but no matter choose what bird repellent equipment must meet the electrical equipment shell and the minimum safety distance of the wire, and shall comply with the relevant standards and norms release by the national electric power industry.%近几年来随着生态环境的不断改善,因鸟类导致高压输电线路跳闸的情况时有发生。防止鸟类侵害、保障输电线路正常运行是电力线路设计的一项重要内容。在实际电力线路设计中,应根据线路所处地理环境、鸟群分布情况及项目投资预算合理地选择驱鸟器的类型及安装区段,但无论选择何种驱鸟设备都必须满足电气设备外壳与导线的最小安全距离的要求,并应符合国家电力行业发布的相关标准和规范。

  5. 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

  6. Differences between left and right ventricular anatomy determine the types of reentrant circuits induced by an external electric shock. A rabbit heart simulation study.

    Science.gov (United States)

    Rodríguez, Blanca; Eason, James C; Trayanova, Natalia

    2006-01-01

    Despite the fact that elucidating the mechanisms of cardiac vulnerability to electric shocks is crucial to understanding why defibrillation shocks fail, important aspects of cardiac vulnerability remain unknown. This research utilizes a novel anatomically based bidomain finite-element model of the rabbit ventricles to investigate the effect of shock polarity reversal on the reentrant activity induced by an external defibrillation-strength shock in the paced ventricles. The specific goal of the study is to examine how differences between left and right ventricular chamber anatomy result in differences in the types of reentrant circuits established by the shock. Truncated exponential monophasic shocks of duration 8 ms were delivered via two external electrodes at various timings. Vulnerability grids were constructed for shocks of reversed polarity (referred to as RV- or LV- when either the RV or the LV electrode is a cathode). Our results demonstrate that reversing electrode polarity from RV- to LV- changes the dominant type of post-shock reentry: it is figure-of-eight for RV- and quatrefoil for LV- shocks. Differences in secondary types of post-shock arrhythmia also occur following shock polarity reversal. These effects of polarity reversal are primarily due to the fact that the LV wall is thicker than the RV, resulting in a post-shock excitable gap that is predominantly within the LV wall for RV- shocks and in the septum for LV- shocks.

  7. Sequential Polarity-Reversing Circuit

    Science.gov (United States)

    Labaw, Clayton C.

    1994-01-01

    Proposed circuit reverses polarity of electric power supplied to bidirectional dc motor, reversible electro-mechanical actuator, or other device operating in direction depending on polarity. Circuit reverses polarity each time power turned on, without need for additional polarity-reversing or direction signals and circuitry to process them.

  8. 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.

  9. 30 CFR 57.6402 - Deenergized circuits near detonators.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Deenergized circuits near detonators. 57.6402... Electric Blasting-Surface and Underground § 57.6402 Deenergized circuits near detonators. Electrical distribution circuits within 50 feet of electric detonators at the blast site shall be deenergized....

  10. Circuit Design on Three-phase Current Unbalance of Electric Vehicle Motor Controller%电动汽车用电机控制器三相电流不平衡检测电路设计

    Institute of Scientific and Technical Information of China (English)

    赵圣宝; 吴成加

    2015-01-01

    In order to improve the reliability and stability of the electric vehicle motor controller, the authors design a type of three-phase current unbalance circuit, including the selection of the current sensor, the circuit of three-phase filter, the inverting summing circuit of three-phase current, the comparator circuit of upper and lower limits and the light-emitting diode warning. Through simulation experiments, the results verify the detection circuit is correct and feasible.%为提高电动汽车电机控制器的可靠性和稳定性,设计一种三相电流不平衡检测电路,包括电流传感器选型及电路、三相滤波电路、三相电流反相求和电路,上/下限比较电路及发光二极管报警电路。通过仿真试验,验证该检测电路是正确和可行的。

  11. 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.

  12. Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric field.

    Science.gov (United States)

    Liu, Chong; Dobrynin, Danil; Fridman, Alexander

    2014-06-25

    In this study, we report experimental results on fast ICCD imaging of development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of electric field in the discharge. Uniformity of the discharge images obtained with nanosecond exposure times were analyzed using chi-square test. The results indicate that DBD uniformity strongly depends on applied (global) electric field in the discharge gap, and is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is transition from filamentary to uniform DBD mode which correlates to the corresponding decrease of maximum local electric field in the discharge.

  13. 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

  14. Hardness and electrical conductivity of alloy wire for track circuit%轨道电路合金导线的硬度及导电性能

    Institute of Scientific and Technical Information of China (English)

    贺帅超; 谭丽

    2016-01-01

    By taking the alloy wire for track circuit with a single addition of Ce , Y and composite addition of Ce +Y as research objects respectively , the influence of alloying elements and heat treatment processes on hardness and electrical conductivity of the Cu -Cr-Zr alloy wire were investigated , and the high temperature softening resistance of the alloy wire was also analyzed .The results show that adding rare earth elements Ce or Y, the hardness of the alloy wire increases by 14-20 HV0.1 after aging, while the electrical conductivity reduces by 2%-4%IACS.The hardness order of the alloy wire aged for the same time from high to low is Cu-Cr-Zr-Ce>Cu-Cr-Zr-Y>Cu-Cr-Zr, while the conductivity order of it from high to low is Cu-Cr-Zr >Cu-Cr-Zr-Ce >Cu-Cr-Zr-Y.The softening temperature of the alloy wire with composite addition of Ce and Y increases by 30 ℃.The precipitation strengthening phase in Cu-Cr-Zr-Ce-Y alloy is mainly CrCu2 ( Zr, Mg) phase.%以单一添加稀土元素Ce、Y和复合添加Ce+Y的Cu-Cr-Zr合金轨道电路导线为研究对象,研究了合金化元素和热处理工艺对Cu-Cr-Zr合金导线的硬度和电导率的影响,并分析了合金导线的抗高温软化性能。结果表明,添加稀土元素Ce、Y的合金导线时效后的硬度提高了14~20 HV0.1,而电导率降低了2~4%IACS;相同时效时间下合金导线硬度从高至低的顺序为Cu-Cr-Zr-Ce>Cu-Cr-Zr-Y>Cu-Cr-Zr,电导率从高至低的顺序为Cu-Cr-Zr>Cu-Cr-Zr-Ce>Cu-Cr-Zr-Y;复合添加Ce+Y合金导线的软化温度提高了约30℃,Cu-Cr-Zr-Ce-Y合金中的时效析出相主要是CrCu2( Zr, Mg)相。

  15. Resonance circuits for adiabatic circuits

    Directory of Open Access Journals (Sweden)

    C. Schlachta

    2003-01-01

    Full Text Available One of the possible techniques to reduces the power consumption in digital CMOS circuits is to slow down the charge transport. This slowdown can be achieved by introducing an inductor in the charging path. Additionally, the inductor can act as an energy storage element, conserving the energy that is normally dissipated during discharging. Together with the parasitic capacitances from the circuit a LCresonant circuit is formed.

  16. 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...

  17. 30 CFR 57.6403 - Branch circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Branch circuits. 57.6403 Section 57.6403... Blasting-Surface and Underground § 57.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits, each branch shall be equipped with a safety switch or equivalent method to isolate...

  18. 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...

  19. 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.

  20. 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

  1. The Dynamical Topological Models of Lagrange’s and Hamiltonian Equations for Complex Nonlinear Electrical Circuit System%复杂非线性电路系统的动力学方程模型

    Institute of Scientific and Technical Information of China (English)

    欧松

    2012-01-01

    Lagrange和Hamilton运动方程是分析力学的基本原理之一和方法论.应用Lagrange和Hamilton原理建立复杂非线性电路保守动力学方程模型是一种形式化可行的方法.对非保守的动力学系统,定义描述电路系统的荷控支路和链控支路的微观结构概念,应用Hamilton结构的方法,可以得到与Lagrange结构等价的方程组;考虑大规模电路系统的复杂性,依据电路系统荷控支路和链控支路微观结构的概念,给出具有控制参量的Lagrange和Hamilton函数,以及具有相应关联矩阵和联接矩阵形式的Lagrange和Hamilton的动态方程;分析了保守和非保守复杂系统拓扑结构关系的描述和其动力学系统的建模,其建模过程具有规范性和方程具有对称性.虽然数学推导过程繁琐,但适合于计算机辅助形式化分析;基于Hamilton方法建立的电路模型为一阶微分动态方程组,特别适合进行理论分析和数值仿真计算.%The Lagrange's and Hamiltonian movement equation are one of the basic principles of analytical mechanics and methodology. The application of Lagrange's and Hamiltonian theory approach to modeling complex nonlinear conservation electrical circuits dynamics system is a practicable in formulation methodology. But for the non conservation electrical circuits dynamics system, a new micro structure conception of electric charge quantitative control branch and magnetic chain control branch in electrical circuit system has been put forward that have equality with the Lagrange's equations; Consideration of the topological complexity of large electrical circuit system, based on the micro structure conception of electric charge quantitative control branch and magnetic chain control branch in electrical circuit, and the Lagrange's and Hamiltonian function that have control parameters are given. ; as well as the Lagrange's and Hamiltonian equations that have incidence matrix and linked matrix; So the

  2. GATING CIRCUITS

    Science.gov (United States)

    Merrill, L.C.

    1958-10-14

    Control circuits for vacuum tubes are described, and a binary counter having an improved trigger circuit is reported. The salient feature of the binary counter is the application of the input signal to the cathode of each of two vacuum tubes through separate capacitors and the connection of each cathode to ground through separate diodes. The control of the binary counter is achieved in this manner without special pulse shaping of the input signal. A further advantage of the circuit is the simplicity and minimum nuruber of components required, making its use particularly desirable in computer machines.

  3. 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.

  4. On the generation of electric field and infrared radiation in aerosol clouds due to radon emanation in the atmosphere before earthquakes

    Directory of Open Access Journals (Sweden)

    V. A. Liperovsky

    2008-10-01

    Full Text Available The non-stationary Frenkel model of the generator of spikes of the local electric field with time scales of 1–100 min in the atmosphere near seismic fracture regions some days before strong earthqukes is analysed. The model suggests an aerosol cloud, an increased ionisation velocity (e.g. by radon emanation, and an upward flow of air. It was found that during times of earthquake activity (that means a few days before an earthquake, for realistic increases of the ionization intensity of the atmosphere, mosaic-likely occurring and disappearing pulses of local electric fields with intensities of the order of 103−3×103 Vm−1 should be observable. These electric fields would also cause spikes of non-equilibrium IR emissions (0.7–20 μm and local spikes of the magnetic field. The authors propose to perform special complex Earth-based observations of the night-time emissions of the atmosphere in the IR region and of the magnetic as well as quasi-stationary electric fields at some points near to fracture regions in seismo-active belts.

  5. Electrical Power Converter

    NARCIS (Netherlands)

    Ferreira, J.A.

    2014-01-01

    Electrical power converter for converting electrical power of a power source connected or connectable at an input to electrical DC-power at an output, wherein between the input and the output a first circuit of submodules is provided, wherein said first circuit of submodules and the power source for

  6. 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.

  7. Circuit Diagram Illustration of Wiring Harness Electrical Junction Box in Front Cabin on HAIMA FSTAR%福仕达前舱线束电气盒电路图解

    Institute of Scientific and Technical Information of China (English)

    张震华; 李鹤丽; 牛鹏浩

    2011-01-01

    介绍海马福仕达豪华型微型客车的线束部件配置明细,并根据全车线束产品图纸,对前舱线束中电气盒的连接电路作出图解。当车载某电气设备不能正常工作时,本文可以作为参照,便于对连接电器设备的线束电路进行查找及故障的排除。%The author introduces the components listing of wiring harness on HAIMA FSTAR minibus(DELUXE);according to the wire harnesses drawing of entire vehicle,illustrates the junction circuit of wiring harness electrical junction box in front cabin.When an electrical equipment can not work normally,this article can be used as a reference in searching and clearing faults for harness circuit connecting electrical equipments.

  8. 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

  9. 30 CFR 57.12053 - Circuits powered from trolley wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuits powered from trolley wires. 57.12053... Electricity Surface and Underground § 57.12053 Circuits powered from trolley wires. Ground wires for lighting circuits powered from trolley wires shall be connected securely to the ground return circuit. Surface Only...

  10. 46 CFR 111.30-17 - Protection of instrument circuits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Protection of instrument circuits. 111.30-17 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-17 Protection of instrument circuits. (a) Each circuit that supplies a device on a switchboard, except a circuit under paragraph (b) of this...

  11. 14 CFR 27.1357 - Circuit protective devices.

    Science.gov (United States)

    2010-01-01

    ... electrical circuit other than— (1) The main circuits of starter motors; and (2) Circuits in which no hazard... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Circuit protective devices. 27.1357 Section 27.1357 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...

  12. 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...

  13. Differential transimpedance amplifier circuit for correlated differential amplification

    Science.gov (United States)

    Gresham, Christopher A.; Denton, M. Bonner; Sperline, Roger P.

    2008-07-22

    A differential transimpedance amplifier circuit for correlated differential amplification. The amplifier circuit increase electronic signal-to-noise ratios in charge detection circuits designed for the detection of very small quantities of electrical charge and/or very weak electromagnetic waves. A differential, integrating capacitive transimpedance amplifier integrated circuit comprising capacitor feedback loops performs time-correlated subtraction of noise.

  14. 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.

  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. 30 CFR 57.6605 - 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. 57.6605 Section... Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting circuits. Lead wires and... shall be protected from sources of stray or static electricity. Blasting circuits shall be...

  17. Selection of Numerical Criterion Value for Determination of Short Circuit Type in Adaptive Micro-Processing Current Protection of Electric Power Lines

    Directory of Open Access Journals (Sweden)

    A. V. Kovalevsky

    2007-01-01

    Full Text Available The paper considers a principle for determination of a short circuit type which is used in the mathematical model of adaptive micro-processing protection with the purpose to improve sensitivity. As a result of a calculative experiment dependences ΔI(t for various short circuit types (three- and two-phase short circuits have been obtained at a number of points of the investigated power network. These dependences make it possible to determine a numerical value of ΔI coefficient. A comparative analysis has been made to study an operation of adaptive and non-adaptive microprocessing protections in the case of asymmetric damages of the investigated power network just in the same points.

  18. TIME DOMAIN REFLECTOMETRY FOR THE LOCALIZATION OF ELECTRICAL FAULTS IN THE INSTRUMENTATION OF THE LHC STRING MAGNETS A Study Case of Voltage Tap, Temperature, and Pressure Transducer Circuits

    CERN Document Server

    Komorowski, P

    1999-01-01

    Time Domain Reflectometry (TDR) is one of the most powerful methods used to analyze the integrity of the signal propagating in a transmission line. The method is based on the principle that the wave propagating in the line is reflected at the locations where the impedance of the line changes. The fault points, joints, branches, junctions, abrupt cross-section changes, etc., cause such reflections. The reflectometry technique involves the excitation of the circuit under test with either a fast edge step function or a well-defined impulse confined in time and frequency domains, and thereafter detection of the amplitude and time of the reflections. Both variants of the method were successfully applied to localize open circuit faults in the voltage tap connections, pressure transducers, and temperature sensing carbon gages circuits of the LHC String Dipole Magnet MB2 and Short Straight Section Quadrupole.

  19. 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

  20. 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)

  1. 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)

  2. The Effect of Sintering Atmosphere on Electrical Characteristics of Fe2TiO5 Pellet Ceramics Sintered at 1200°C for NTC Thermistor

    Science.gov (United States)

    Wiendartun; Risdiana; Fitrilawati; Siregar, R. E.

    2016-08-01

    Fabrication of Fe2TiO5 pellet ceramics using powder metallurgy technique for NTC thermistor has been carried out, in order to know the effect of sintering atmosphere (Oxygen, Air and Argon Gas) on the characteristic especially the electrical characteristic of Fe2TiO5 ceramics with high working temperature. X-ray diffraction analyses (XRD) was done to know crystal structure and phases formation. A SEM analysis was carried out to know microstructure of pellets. Electrical properties characterization was done through measurement of electrical resistance at various temperatures (room temperature to 250oC). The XRD data showed that the pellets crystallize in orthorhombic. The presence of second phase could not be identified from the XRD analyses. The SEM images showed that the grains size of the ceramic sintered in oxygen gas is smaller than that of the ceramic sintered in air and argon gas. Electrical data showed that the pellet ceramics sintered in oxygen gas had the largest room temperature resistance (RRT), thermistor constant (B), activation energy (Ea) and sensitivity (α) compared to those sintered in air and argon gas. From the electrical characteristics data, it was known that the electrical characteristics of the Fe2TiO5 pellet ceramics followed the NTC characteristic. The value of B and RRT of the produced Fe2TiO5 ceramics namely B = 4389-6149 K and Rrt = 342-26548kQ, fitted market requirement and can be used for temperature sensor.

  3. Variations in electric and meteorological parameters in the near-Earth's atmosphere at Kamchatka during the solar events in October 2003

    Science.gov (United States)

    Smirnov, S. E.; Mikhailova, G. A.; Kapustina, O. V.

    2014-03-01

    The diurnal variations in the electric conductivity, electric-field strength, and meteorological parameters in the near-Earth's atmosphere during the solar events in October 21-31, 2003, have been studied. It has been indicated that the conductivity and electric-field strength strongly depend on the air temperature and humidity. It has been found that the conductivity increased for 2 days before the geomagnetic storm on October 29-30 as a result of the effect of solar cosmic rays and decreased during a Forbush decrease in galactic cosmic rays, which was accompanied by a corresponding increase in the electric-field strength. It has been found that the air temperature and humidity anomalously increased in the process of solar activity, which resulted in the formation of different clouds, including thunderclouds accompanied by thunderstorm processes and showers. Simultaneous disturbances of the regular meteorological processes, solar flare series, and emission intensification in the near ultraviolet band, and visible and infrared spectral regions make it possible to consider these processes as a source of additional energy inflow into the lower atmosphere.

  4. Developing a Domain Model for Relay Circuits

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth

    2009-01-01

    the statics as well as the dynamics of relay circuits, i.e. how a relay circuit can be composed legally from electrical components as well as how the components may change state over time. Finally the circuit model is transformed into an executable model, and we show how a concrete circuit can be defined......In this paper we stepwise develop a domain model for relay circuits as used in railway control systems. First we provide an abstract, property-oriented model of networks consisting of components that can be glued together with connectors. This model is strongly inspired by a network model...... for railways madeby Bjørner et.al., however our model is more general: the components can be of any kind and can later be refined to e.g. railway components or circuit components. Then we show how the abstract network model can be refined into an explicit model for relay circuits. The circuit model describes...

  5. CO2气体保护焊短路过渡过程与电参数的关系%RELATIONSHIP BETWEEN SHORT CIRCUIT TRANSFER OF CO2 ARC WELDING AND ITS ELECTRIC PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    李桓; 杨立军; 李俊岳; 邓黎丽; 张宝红

    2001-01-01

    用计算机控制的高性能数据采集系统对CO2焊短路过渡过程的电参数进行了研究.分析认为可利用电弧电压来指示熔滴短路及电弧复燃,利用电弧电压的微分来指示液体小桥缩颈,为CO2焊短路过渡实时控制奠定了基础.%The electric parameters of the short-circuit transfer of CO2 arc welding are examined totally and systematically by using an advanced data-collecting system controlled by a computer.Stadies and analysis of the above data show that the arc voltage can reflect the droplet short circuit and the arc re-start,and its differential signal can indicate the pinch of the liquid bridge.This is a better foundation for developing the real-time control of short-circuit transfer of CO2 arc welding.

  6. 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...

  7. 46 CFR 169.243 - Electrical.

    Science.gov (United States)

    2010-10-01

    ... disturbance of the cable or electrical apparatus. (b) Overload or circuit protective devices. Circuit breakers..., lighting fixtures and circuit interrupting devices located in spaces or areas which may contain...

  8. 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.

  9. Electric Parameters of Test Circuit for Switching Capacitor Banks in UHVAC Transformer Substation%特高压变电站电容器组开合试验回路的电气参数

    Institute of Scientific and Technical Information of China (English)

    杨堃; 崔博源; 宋杲; 金黎明; 和彦淼

    2013-01-01

      In view of greater change of power transmitted in UHV power grid, the control of reactive power and voltage is very significant and one of the important manners to control grid voltage is switching capacitor banks configured at the third winding side of main transformer, and in actual operation of UHV power grid the capacitor banks are frequently switched. Moreover, in view of the distinctiveness of UHV transmission project, the requirement of UHV transmission system on the technical parameters of circuit breakers to switch capacitor banks is higher than those specified in related standards, and up to now the electrical endurance tests, which reaches engineering requirement of UHV transmission project, for the on-site operated capacitor bank breakers (CBB) are not yet performed. To verify the electrical endurance of CBB and to analyze technical requirement to CBB installed in UHVAC transformer substations and the differences between technical parameters of CBB and those of other UHV circuit breakers specified in standards, the equivalence of performing electrical endurance tests by the synthetic test circuit is discussed. The test circuit is constructed and main parameters are computed. Simulation results show that the testing parameters of the synthetic test circuit can meet the requirements of electrical endurance test for CBB, thus the effective electrical endurance examination of CBB can be ensured.%  特高压电网送电功率变化较大,无功电压控制问题比较突出,控制系统电压的重要手段是投切主变三次侧的电容器组,实际运行中投切电容器组的频率很高。另外,由于特高压工程的特殊性,其对投切电容器组断路器的技术参数要求也高于相关标准,而目前现场运行的投切电容器组断路器未进行达到特高压工程要求的电寿命试验。为验证断路器投切电容器组电寿命能力,分析特高压交流变电站投切电容器组断路器技术要

  10. Home Electrical Safety Checklist

    Science.gov (United States)

    ... in kitchens, bathrooms, and other areas where the risk of electric shock is higher. Consider having GFCIs installed in ... life. By installing GFCIs, you are reducing your risk of electric shock. AFCIs are special circuit breakers that detect ...

  11. 46 CFR 169.682 - Distribution and circuit loads.

    Science.gov (United States)

    2010-10-01

    ... Machinery and Electrical Electrical Installations Operating at Potentials of 50 Volts Or More on Vessels of... be installed; or (2) 50 watts per outlet. (b) Circuits supplying electrical discharge lamps must be computed using the ballast input current. (c) The branch circuit cables for motor and lighting loads...

  12. Inter digital transducer modelling through Mason equivalent circuit model

    DEFF Research Database (Denmark)

    Mishra, Dipti; Singh, Abhishek; Hussain, Dil muhammed Akbar

    2016-01-01

    The frequency reliance of inter-digital transducer is analyzed with the help of MASON's Equivalent circuit which is based on Smith's Equivalent circuit which is further based on Foster's Network. An inter-digital transducer has been demonstrated as a RLC network. The circuit is simulated...... by Simulation program with Integrated Circuit Emphasis (HSPICE), a well-liked electronic path simulator. The acoustic wave devices are not suitable to simulation through circuit simulator. In this paper, an electrical model of Mason's Equivalent electrical circuit for an inter-digital transducer (IDT...

  13. The integration of 3D electrical resistivity tomography and ET flux measurements to characterize water mass balance in the soil-plant-atmosphere continuum

    Science.gov (United States)

    Vanella, Daniela; Boaga, Jacopo; Perri, Maria Teresa; Consoli, Simona; Cassiani, Giorgio

    2014-05-01

    The system of soil, vegetation, and the adjacent atmosphere is characterized by complex patterns, structures, and processes that act on a wide range of time and space scales. While the exchange of energy and water is continuous between compartments, the pertinent fluxes are strongly heterogeneous and variable in space and time. Therefore, quantitatively predicting the systems' behaviour constitutes a major challenge. Traditionally, soil moisture beneath irrigated crops has been determined using point measurement methods such as neutron probes or capacitance systems. These approaches cannot measure soil moisture at depths beyond the root-zone of plants and have limited lateral coverage. Literature results show that electrical resistivity tomography (ERT) can be used to reliable map the spatial heterogeneity in soil moisture. Here we present the application of the time-lapse non-invasive 3D micro - electrical tomography (ERT) to monitor soil-plant interactions in the root zone of an orange tree located in the Mediterranean semi-arid Sicilian (South Italy) context. The subsoil dynamics, particularly influenced by irrigation and root uptake, has been characterized a 3D ERT apparatus consisting of 48 buried electrodes on 4 instrumented micro boreholes plus 24 mini-electrodes on the surface spaced 0.1 m on a square grid. During the monitoring, repeated ERT soil moisture measurements were collected, as well as laboratory characterization of the soil electrical properties as a function of moisture content and pore water electrical conductivity. Plant transpiration was continuously monitored during the ERT experiment by the sap flow heat pulse (HP) method for a quantitative analysis of the mass balance in the soil-plant-atmosphere system under observation. In addition, evapo-transpiration has been continuously monitored at the same site using an eddy-correlation tower. The integration of measurements regarding soil,plant and atmosphere allows a better understanding of

  14. Integrated capacitors for conductive lithographic film circuits

    OpenAIRE

    Harrey, PM; Evans, PSA; Harrison, DJ

    2001-01-01

    This paper reports on fabrication of low-value embedded capacitors in conductive lithographic film (CLF) circuit boards. The CLF process is a low-cost and high speed manufacturing technique for flexible circuits and systems. We report on the construction and electrical characteristics of CLF capacitor structures printed onto flexible substrates. These components comprise a single polyester dielectric layer, which separates the printed electrode films. Multilayer circuit boards with printed co...

  15. Matlab in electrical engineering

    OpenAIRE

    Stelian MARINESCU; Gabriel CHEREGI; Marilena STANCULESCU

    2009-01-01

    Electrical Engineering education addresses to high technologies needs from industry and business offering academic curricula which include topics such as: integrated circuits, digital signal processing, microwaves, optical engineering, bioelectronics, propagation and radiation, power electronics, control systems, communications, circuit theory, robotics, nondestructive testing. Matlab is a widely used tool in electrical engineering. It can be used to enhance and accelerate some processes, suc...

  16. Graphene radio frequency receiver integrated circuit.

    Science.gov (United States)

    Han, Shu-Jen; Garcia, Alberto Valdes; Oida, Satoshi; Jenkins, Keith A; Haensch, Wilfried

    2014-01-01

    Graphene has attracted much interest as a future channel material in radio frequency electronics because of its superior electrical properties. Fabrication of a graphene integrated circuit without significantly degrading transistor performance has proven to be challenging, posing one of the major bottlenecks to compete with existing technologies. Here we present a fabrication method fully preserving graphene transistor quality, demonstrated with the implementation of a high-performance three-stage graphene integrated circuit. The circuit operates as a radio frequency receiver performing signal amplification, filtering and downconversion mixing. All circuit components are integrated into 0.6 mm(2) area and fabricated on 200 mm silicon wafers, showing the unprecedented graphene circuit complexity and silicon complementary metal-oxide-semiconductor process compatibility. The demonstrated circuit performance allow us to use graphene integrated circuit to perform practical wireless communication functions, receiving and restoring digital text transmitted on a 4.3-GHz carrier signal.

  17. 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…

  18. 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…

  19. 30 CFR 57.6407 - Circuit testing.

    Science.gov (United States)

    2010-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Electric Blasting-Surface and Underground § 57.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing blasting circuits shall be used to test the following: (a) In surface operations—...

  20. 真空断路器电磨损监测与诊断方法综述%Review of Monitoring and Diagnosis Methods for Vacuum Circuit Breaker Electrical Wear

    Institute of Scientific and Technical Information of China (English)

    范兴明; 贺家敏; 潘永成; 刘旭东; 黄知超; 张鑫; 李震; 刘华东

    2011-01-01

    随着基于智能电网、数字化变电站、非常规互感器技术及IEC 61850标准和基于可靠性的状态检修体制的发展,高压开关设备的智能化逐渐引起电器生产和使用人员的重视.文中描述了影响真空断路器电寿命的判据,分析了真空断路器触头电寿命及其在工程应用中的可行折算式,总结了国内外监测开断电流起孤时刻的方法.以分析为基础并概述了各种不同折算式的适用性及各种监测方法的特点,着重强调了各种方法的工程实用性和起弧时刻监测的重要性,并在此基础上讨论了现有检修和检测手段的缺陷,展望了真空断路器电寿命监测技术发展的方向.%Accompany with the application of intelligent power grid, digitized substation,unconventional transformer technology, IEC 61850 standards and the development of condition-based maintenance system(CBMS) that attention is highly paid to the HV intelligent switchgear by the electrical device producer and the user.The electrical-endurance quality of vacuum circuit-breaker is described, and the vacuum circuit breaker contactor wear is analyzed. Then the application of feasible calculation formula in engineering is discussed. Methods of monitoring arcing duration at home and abroad are summarized, and the applicability of applications of different calculation converted formulas are presented and the characteristics of various monitoring methods are investigated, which based on a series of analysis. The engineering practicability and the arcs moment monitoring are mainly emphasized. In the end the defects of maintenance and detection are discussed and the technology development direction of vacuum circuit breaker's electrical endurance is prospected, which based upon what mentioned above.

  1. Measurements of the Atmospheric Electric Field through a Triangular Array and the Long-range Saharan Dust Electrification in Southern Portugal

    CERN Document Server

    Silva, H G; Pereira, S; 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 dust event corresponding to space-charges of ~20-2 pCm-3 (charge layer thicknesses ~10-100 m). A reduction of AEF is observed after the dust event.

  2. Detecting spectrally localized components of lunar tide-frequency in time-series of the electric field vertical component of the earth atmosphere boundary layer

    CERN Document Server

    Isakevich, V V; Isakevich, D V

    2016-01-01

    Using the signal eigenvectors and components analyser (Grunskaya L.V., Isakevich V.V., Isakevich D.V. the RF Utility Model Patent 116242 of 30.09.2011) made it possible to detect non-coherent complex-period components localized at lunar tide frequencies in the time-series of the electric field vertical component of the Earth atmosphere boundary layer. The detected components are unobservable by means of spectral analysis quadrature scheme. The probability of the detected effects being pseudo-estimates is not more than 0.00025

  3. Affective Circuits

    DEFF Research Database (Denmark)

    to the intersecting streams of goods, people, ideas, and money as they circulate between African migrants and their kin who remain back home. They also show the complex ways that emotions become entangled in these exchanges. Examining how these circuits operate in domains of social life ranging from child fosterage......Moving between Africa and Europe, the book explores the many ways migrants sustain and rework family ties and intimate relationships at home and abroad. It demonstrates how their quotidian efforts—on such a mass scale—contribute to a broader process of social regeneration. The contributors point...

  4. Introduction to multiple current system of electrical locomotive main circuit topology structure%浅谈多流制电力机车主电路拓扑结构

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      随着经济的发展,世界铁路多种电流制式电力机车跨界运输越来越常见,地区铁路与城市轨道交通互通连接也成为一种发展趋势。但国内对双流制电力机车的研究还处于起步阶段。文章介绍了三种欧洲典型的多流制电力机车主电路拓扑结构和主要特点,并进行了简要的对比和分析。%With the development of economy ,the world railway multiple current system electrical locomotive cross -border transporta-tion is more and more common ,regional railway and urban rail transit also has become a development trend of each connection .But the domestic study of multiple current system electrical locomotive is still in its infancy .This paper introduces the three kinds of typical Eu-ropean multi-current system of electrical locomotive main circuit topology structure and the main features ,and a brief comparison and analysis .

  5. 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

    Directory of Open Access Journals (Sweden)

    E. Defer

    2014-08-01

    Full Text Available The PEACH (Projet en Electricité Atmosphérique pour la Campagne HyMeX – the Atmospheric Electricity Project of HyMeX Program project is the Atmospheric Electricity component of the HyMeX (Hydrology cycle in the Mediterranean Experiment 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; 5 September–6 November 2012, four European Operational Lightning Locating Systems (OLLSs (ATDNET, EUCLID, LINET, ZEUS and the HyMeX Lightning Mapping Array network (HyLMA were used to locate and characterize the lightning activity over the Southeastern Mediterranean at flash, storm and regional scales. Additional research instruments like slow antennas, video cameras, micro-barometer and microphone arrays were also operated. All these observations in conjunction with operational/research ground-based and airborne radars, rain gauges and in situ microphysical records aimed at characterizing and understanding electrically active and highly precipitating events over Southeastern France that often lead to severe flash floods. Simulations performed with Cloud Resolving Models like Meso-NH and WRF are used to interpret the results and to investigate further the links between dynamics, microphysics, electrification and lightning occurrence. A description of the different instruments deployed during the field campaign as well as the available datasets is given first. Examples of concurrent observations from radio frequency to acoustic for regular and atypical lightning flashes are then presented showing a rather comprehensive description of lightning flashes available from the SOP1 records. Then examples of storms recorded during HyMeX SOP1 over Southeastern France are briefly described to highlight the unique and rich dataset collected. Finally the next steps of the work required for the

  6. 电力机车辅助电路移相电容控制方法的改进%Improvement of control method of phase shifting capacitor on electric locomotive auxiliary circuit

    Institute of Scientific and Technical Information of China (English)

    王安明

    2013-01-01

    Used method that shifting phase capacitor series thyristor in electric locomotive auxiliary circuit , eliminates in the closing moments generated current shock .Simulating to use the PSIM simulation software , in the same simulation parameters , contrast the power factor curve using thyristor in the series of shifting phase capacitor , after series of shifting phase capacitor uses thyristor the power factor of the circuit is improved obviously .%  在电力机车辅助电路移相电容支路中采用串联晶闸管的方法,消除了在合闸瞬间产生的电流冲击。利用PSIM仿真软件进行了仿真实验,在相同的仿真参数下,对比了移相电容支路串联晶闸管前后的功率因数曲线,可以看出,在移向电容支路串联晶闸管后电路的功率因数明显提高。

  7. Collective of mechatronics circuit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-02-15

    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.

  8. The Effect of Combining Analogy-Based Simulation and Laboratory Activities on Turkish Elementary School Students' Understanding of Simple Electric Circuits

    Science.gov (United States)

    Unlu, Zeynep Koyunlu; Dokme, Ibilge

    2011-01-01

    The purpose of this study was to investigate whether the combination of both analogy-based simulation and laboratory activities as a teaching tool was more effective than utilizing them separately in teaching the concepts of simple electricity. The quasi-experimental design that involved 66 seventh grade students from urban Turkish elementary…

  9. 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

    2014-01-01

    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…

  10. 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

  11. 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.

  12. Circuit For Control Of Electromechanical Prosthetic Hand

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

  13. Diagnostics of Atmospheric Pressure Surface Discharge Plasmas in Argon

    Institute of Scientific and Technical Information of China (English)

    张锐; 詹如娟; 温晓辉

    2003-01-01

    Atmospheric pressure surface discharge is shown to have great prospects for a number of industrial applications.To acquire better results in application fields and considering that the study of the basic parameters including electron temperature and electron density is desirable,we develop an equivalent circuit model and the diagnostic techniques based on optical emission spectroscopy and electrical measurement in our laboratory.The electron temperature has been determined to be about 0.7eV by a Fermi-Dirac model.The electron density has been calculated to be near 1010 cm-3 from a time resolved electrical measurement(Ohmic heating method).

  14. 46 CFR 58.25-65 - Feeder circuits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Feeder circuits. 58.25-65 Section 58.25-65 Shipping... AND RELATED SYSTEMS Steering Gear § 58.25-65 Feeder circuits. (a) Each vessel with one or more electric-driven steering-gear power units must have at least two feeder circuits, which must be...

  15. 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... § 236.732 Controller, circuit; switch. A device for opening and closing electric circuits, operated by a rod connected to a switch, derail or movable-point frog....

  16. Commutation circuit for an HVDC circuit breaker

    Science.gov (United States)

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  17. 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.

  18. 标识在电气一次接线图上的应用现状和建议%Application Status of Identification in Electrical Primary Circuit Diagrams and Suggestions

    Institute of Scientific and Technical Information of China (English)

    蒋宝元; 金建源

    2012-01-01

    简要梳理了标识在我国电气简图上应用的历史,重点综述了标注在电气一次接线图上的标识的应用现状.通过对电厂标识系统与参照代号系统的对比分析,指出了国内推广新标识所存在的困难和矛盾,并提出改进的意见.%This paper provides a brief account of the history of the application of identification of electrical diagrams in China, with emphasis on reviewing the application status of identification in electrical primary circuit diagrams. Based on the comparison and analysis of identification system for power plants and reference designation system, this paper pinpoints the difficulties and dilemma of popularizing new identification in China and advances some suggestions on the improvement.

  19. The Optical Properties of the Maritime Aerosol and their Correlation to the Electrical Conductivity of the Marine Atmosphere

    Science.gov (United States)

    2016-06-07

    constrain the conductivity measurements in coastal areas where continental air containing radioactive agents may be present to varying degrees. WORK COMPLETED...this project are also valuable in projects such as those outlined in the last item. Also, however, the results will enhance the value of a century long record of conductivity measurements that exists. ...simultaneously measuring aerosol properties, optical properties, and electrical properties from an aircraft in the marine boundary layer. This

  20. Análisis Simbólico en Circuitos Electrónicos Analógicos Manipulando Estructuras de Datos Symbolic Analysis of Analog Electronic Circuits by Manipulation of Data Structures

    Directory of Open Access Journals (Sweden)

    E. Tlelo

    2004-01-01

    Full Text Available Se presenta un método novedoso para mejorar el proceso de formulación del sistema de ecuaciones que describen el comportamiento de un circuito electrónico aplicando análisis simbólico. El comportamiento de los circuitos electrónicos se modela utilizando anuladores (nullors, lo que permite representar sus relaciones de interconexión usando estructuras de datos simples. De esta forma, se demuestra que el sistema de ecuaciones compacto puede calcularse al evaluar el producto cartesiano de las relaciones de interconexión asociadas a los elementos terminal nulo (nullator y terminal libre (norator. Utilizando esta técnica de formulación se minimiza la complejidad computacional durante la manipulación de expresiones simbólicas. El sistema de ecuaciones compacto se formula llenando directamente una matriz de admitancia cuyo orden, es igual al número de nodos menos el número de nullors. Se concluye que las expresiones simbólicas calculadas, son útiles para procedimientos de síntesis y optimización de un diseño electrónicoA novel method is presented to improve the formulation process of the system of equations describing the behavior of an electronic circuit by applying symbolic analysis. The behavior of an electronic circuit is modeled by using nullors, which is quite useful in representing their interconnection relationships by using simple data structures. In this form, it is demonstrated that the compacted system of equations can be computed by evaluating the Cartesian product of the interconnection associated to the nullator and norator. By using this formulation technique, the computational complexity during the manipulation of symbolic expressions is minimized. The compact system of equations is formulated by direct fill-in of an admittance matrix whose order is equal to the number of nodes minus the number of nullors. It is concluded that the calculated symbolic expressions are useful for synthesis and optimization procedures