WorldWideScience

Sample records for high critical electric

  1. Economic analysis of electric heating based on critical electricity price

    Science.gov (United States)

    Xie, Feng; Sun, Zhijie; Zhou, Xinnan; Fu, Chengran; Yang, Jie

    2018-06-01

    The State Grid Corporation of China proposes an alternative energy strategy, which will make electric heating an important task in the field of residential electricity consumption. This article takes this as the background, has made the detailed introduction to the inhabitant electric heating technology, and take the Zhangjiakou electric panels heating technology as an example, from the expense angle, has carried on the analysis to the electric panels heating economy. In the field of residential heating, electric panels operating costs less than gas boilers. After customers implying energy-saving behavior, electric panels operating cost is even lower than coal-fired boilers. The critical price is higher than the execution price, which indicates that the economic performance of the electric panels is significantly higher than that of the coal boiler.

  2. The changing Swiss electricity - Critical views

    International Nuclear Information System (INIS)

    Wilms, E.F.J.

    2001-01-01

    This book takes a critical look at developments in the Swiss electricity market and, in particular, criticises national, regional and local energy policy, which the author considers to be incoherent. The book first describes how the electricity market works, the main players involved and the daily problems that have to be solved. Then, the problems that could be caused by liberalisation, including the question of transit fees, the development of electricity prices for consumers, changes in the structure of the electricity business and third party access are discussed. The second part of the book examines legal aspects of proposed electricity market legislation and then presents 16 propositions covering energy policy, market regulation, unbundling not only of electricity generation, distribution and services but also of politics and business, the revision of proposed liberalisation legislation, taxation aspects as well as the national and international operation of the electricity grid. The book further examines three regional electricity utilities and the attempts to privatise them, which did not meet with the approval of the voting public, and discusses the suspicion cast on certain politicians, that they try to push through the particular interests of groups they are closely associated with. The book is also includes a bibliography and a list of useful addresses

  3. High Critical Current Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, M. P.; Selvamanickam, V. (SuperPower, Inc.)

    2011-12-27

    One of the important critical needs that came out of the DOE’s coated conductor workshop was to develop a high throughput and economic deposition process for YBCO. Metal-organic chemical vapor deposition (MOCVD) technique, the most critical steps in high technical micro fabrications, has been widely employed in semiconductor industry for various thin film growth. SuperPower has demonstrated that (Y,Gd)BCO films can be deposited rapid with world record performance. In addition to high critical current density with increased film thickness, flux pinning properties of REBCO films needs to be improved to meet the DOE requirements for various electric-power equipments. We have shown that doping with Zr can result in BZO nanocolumns, but at substantially reduced deposition rate. The primary purpose of this subtask is to develop high current density MOCVD-REBCO coated conductors based on the ion-beam assisted (IBAD)-MgO deposition process. Another purpose of this subtask is to investigate HTS conductor design optimization (maximize Je) with emphasis on stability and protection issues, and ac loss for REBCO coated conductors.

  4. A critical review of electric earthquake precursors

    Energy Technology Data Exchange (ETDEWEB)

    Tzanis, A. [Athens Univ., Athens (Italy). Dept. of Geophysics and Geothermy; Valliantos, F. [Technological Educational Institute of Crete, Chania (Greece)

    2001-04-01

    reliable electric field measurements, although improvements are still possible with new generation and smart measurement schemes facilitating noise suppression. It is increasingly apparent that simultaneous electric and magnetic measurements are indispensable and conducted in most new experiments. There is also an emerging trend towards multi-parametric, broadband observations that should provide far better data and constraints on the source processes. The physics of electrification mechanisms are beginning to clarify, as also is the potential of solid state effects: charge and current densities under controlled conditions are such, that if scaled up to the size of seismogenic zones, they would yield observable EEP. However, there are still many unknowns, requiring careful experimentation and theoretical development. Research is also directed towards decoding the physics of stress/strain changes that cause electrification, exploiting properties such as are the fractal nature of faulting and Self-Organised Critically (SOC). The first evidence of possible electromagnetic precursors due to a SOC system has been published recently. Modelling of the source processes from first principles is stepping up and certain classes of observed signals can now be predicted by theory, providing new and more rigorous means of data authentication; such models have also established the feasibility of long range EEP signals. Although progress is apparent, the knowledge is still grossly incomplete and EEP data are not indisputable, if tested with the full rigour of scientific verification methods. The new research philosophy requires time and vigilance before it begins to pay off, but it appears to have taken a more promising course.

  5. A critical review of Electric Earthquake Precursors

    Directory of Open Access Journals (Sweden)

    F. Vallianatos

    2001-06-01

    and can guarantee reliable electric field measurements, although improvements are still possible with new generation electrodes and smart measurement schemes facilitating noise suppression. It is increasingly apparent that simultaneous electric and magnetic measurements are indispensable and conducted in most new experiments. There is also an emerging trend towards multi-parametric, broadband observations that should provide far better data and constraints on the source processes. The physics of electrification mechanisms are beginning to clarify, as also is the potential of solid state effects: charge and current densities under controlled conditions are such, that if scaled up to the size of seismogenic zones, they would yield observable EEP. However, there are still many unknowns, requiring careful experimentation and theoretical development. Research is also directed towards decoding the physics of stress/strain changes that cause electrification, exploiting properties such as are the fractal nature of faulting and Self-Organised Criticality (SOC. The first evidence of possible electromagnetic precursors due to a SOC system has been published recently. Modelling of the source processes from first principles is stepping up and certain classes of observed signals can now be predicted by theory, providing new and more rigorous means of data authentication; such models have also established the feasibility of long range EEP signals. Although progress is apparent, the knowledge is still grossly incomplete and EEP data are not indisputable, if tested with the full rigour of scientific verification methods. The new research philosophy requires time and vigilance before it begins to pay off, but it appears to have taken a more promising course.

  6. Correlation of Critical Temperatures and Electrical Properties in Titanium Films

    Science.gov (United States)

    Gandini, C.; Lacquaniti, V.; Monticone, E.; Portesi, C.; Rajteri, M.; Rastello, M. L.; Pasca, E.; Ventura, G.

    Recently transition-edge sensors (TES) have obtained an increasing interest as light detectors due to their high energy resolution and broadband response. Titanium (Ti), with transition temperature up to 0.5 K, is among the suitable materials for TES application. In this work we investigate Ti films obtained from two materials of different purity deposited by e-gun on silicon nitride. Films with different thickness and deposition substrate temperature have been measured. Critical temperatures, electrical resistivities and structural properties obtained from x-ray are related to each other.

  7. Critical electric field for maximum tunability in nonlinear dielectrics

    Science.gov (United States)

    Akdogan, E. K.; Safari, A.

    2006-09-01

    The authors develop a self-consistent thermodynamic theory to compute the critical electric field at which maximum tunability is attained in a nonlinear dielectric. They then demonstrate that the stored electrostatic free energy functional has to be expanded at least up to the sixth order in electric field so as to define the critical field, and show that it depends solely on the fourth and sixth order permittivities. They discuss the deficiency of the engineering tunability metric in describing nonlinear dielectric phenomena, introduce a critical field renormalized tunability parameter, and substantiate the proposed formalism by computing the critical electric field for prototypical 0.9Pb(Mg1/3,Nb2/3)-0.1PbTiO3 and Ba(Ti0.85,Sn0.15)O3 paraelectrics.

  8. Residential implementation of critical-peak pricing of electricity

    International Nuclear Information System (INIS)

    Herter, Karen

    2007-01-01

    This paper investigates how critical-peak pricing (CPP) affects households with different usage and income levels, with the goal of informing policy makers who are considering the implementation of CPP tariffs in the residential sector. Using a subset of data from the California Statewide Pricing Pilot of 2003-04, average load change during summer events, annual percent bill change, and post-experiment satisfaction ratings are calculated across six customer segments, categorized by historical usage and income levels. Findings show that high-use customers respond significantly more in kW reduction than do low-use customers, while low-use customers save significantly more in percentage reduction of annual electricity bills than do high-use customers-results that challenge the strategy of targeting only high-use customers for CPP tariffs. Across income levels, average load and bill changes were statistically indistinguishable, as were satisfaction rates-results that are compatible with a strategy of full-scale implementation of CPP rates in the residential sector. Finally, the high-use customers earning less than $50,000 annually were the most likely of the groups to see bill increases-about 5% saw bill increases of 10% or more-suggesting that any residential CPP implementation might consider targeting this customer group for increased energy efficiency efforts

  9. Risk analysis of critical infrastructures emphasizing electricity supply and interdependencies

    International Nuclear Information System (INIS)

    Kjølle, G.H.; Utne, I.B.; Gjerde, O.

    2012-01-01

    Failures in critical infrastructures can cause major damage to society. Wide-area interruptions (blackouts) in the electricity supply system have severe impacts on societal critical functions and other critical infrastructures, but there is no agreed-upon framework on how to analyze and predict the reliability of electricity supply. Thus, there is a need for an approach to cross-sector risk analyses, which facilitates risk analysis of outages in the electricity supply system and enables investigation of cascading failures and consequences in other infrastructures. This paper presents such an approach, which includes contingency analysis (power flow) and reliability analysis of power systems, as well as use of a cascade diagram for investigating interdependencies. A case study was carried out together with the Emergency Preparedness Group in the city of Oslo, Norway and the network company Hafslund Nett. The case study results highlight the need for cross-sector analyses by showing that the total estimated societal costs are substantially higher when cascading effects and consequences to other infrastructures are taken into account compared to only considering the costs of electricity interruptions as seen by the network company. The approach is a promising starting point for cross-sector risk analysis of electricity supply interruptions and consequences for dependent infrastructures.

  10. High current capacity electrical connector

    International Nuclear Information System (INIS)

    Bettis, E.S.; Watts, H.L.

    1976-01-01

    An electrical connector is provided for coupling high current capacity electrical conductors such as copper busses or the like. The connector is arranged in a ''sandwiched'' configuration in which a conductor plate contacts the busses along major surfaces clamped between two stainless steel backing plates. The conductor plate is provided with contact buttons in a spaced array such that the caps of the buttons extend above the conductor plate surface to contact the busses. When clamping bolts provided through openings in the sandwiched arrangement are tightened, Belleville springs provided under the rim of each button cap are compressed and resiliently force the caps into contact with the busses' contacting surfaces to maintain a predetermined electrical contact area provided by the button cap tops. The contact area does not change with changing thermal or mechanical stresses applied to the coupled conductors

  11. Searching for superconductors with high critical temperature

    Energy Technology Data Exchange (ETDEWEB)

    Chao, C

    1977-08-18

    Critical temperature of superconductors can be and must be raised so that their range of application can be broadened. It was estimated that, in 3 to 5 years, superconductor electric generators might be used in nuclear submarines and/or other applications where the requirements of small volume and light weight are critical. The BCS theory was recapitulated. Possible methods of achieving higher critical temperature were proposed and discussed.

  12. The electricity supply industry as a subject for public criticism

    International Nuclear Information System (INIS)

    Bartsch, R.

    1977-01-01

    The German electricity supply industry is becoming the subject for more public criticism although it has supplied the whole population and industry in recent years with electricity without limitations and at a favourable price. In spite of the satisfactory and exemplary achievements of this branch of the economy a wave of criticism has built up, caused by the increase in nuclear power station construction, and this is assuming greater proportions and includes wider fields. This situation requires a matching publicity campaign in a number of directions which must be preceded by comprehensive research into causes. It is urgently necessary to achieve a realisation of the basic questions in this branch of the economy in all those, engaged in electricity supply. Full information on the special physical characteristics of the electricity produced, with all the consequences which follow from these, must be supplied to the relevant groups in society both within and outside the economy and also to the mass media, together with continuous efforts to gain the trust of the public. (orig.) [de

  13. Development of high temperature superconductors having high critical current density

    International Nuclear Information System (INIS)

    Hong, Gye Wong; Kim, C. J.; Lee, H.G.; Kwon, S. C.; Lee, H. J.; Kim, K. B.; Park, J. Y.; Jung, C. H.

    2000-08-01

    Fabrication of high T c superconductors and its applications for electric power device were carried out for developing superconductor application technologies. High quality YBCO superconductors was fabricated by melt texture growth, top-seeded melt growth process and multi-seeded melt growth process and the properties was compared. The critical current density of the melt processed YBCO superconductors was about few 10,000 A/cm 2 and the levitation force was 50 N. The processing time needed for the growth of the 123 single grain was greatly reduced by applying multi-seeding without no significant degradation of the levitation force. The multi-seeded melt growth process was confirmed as a time-saving and cost-effective method for the fabrication of bulk superconductors with controlled crystallographic orientation

  14. Development of high temperature superconductors having high critical current density

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Gye Wong; Kim, C. J.; Lee, H.G.; Kwon, S. C.; Lee, H. J.; Kim, K. B.; Park, J. Y.; Jung, C. H

    2000-08-01

    Fabrication of high T{sub c} superconductors and its applications for electric power device were carried out for developing superconductor application technologies. High quality YBCO superconductors was fabricated by melt texture growth, top-seeded melt growth process and multi-seeded melt growth process and the properties was compared. The critical current density of the melt processed YBCO superconductors was about few 10,000 A/cm{sup 2} and the levitation force was 50 N. The processing time needed for the growth of the 123 single grain was greatly reduced by applying multi-seeding without no significant degradation of the levitation force. The multi-seeded melt growth process was confirmed as a time-saving and cost-effective method for the fabrication of bulk superconductors with controlled crystallographic orientation.

  15. High to ultra-high power electrical energy storage.

    Science.gov (United States)

    Sherrill, Stefanie A; Banerjee, Parag; Rubloff, Gary W; Lee, Sang Bok

    2011-12-14

    High power electrical energy storage systems are becoming critical devices for advanced energy storage technology. This is true in part due to their high rate capabilities and moderate energy densities which allow them to capture power efficiently from evanescent, renewable energy sources. High power systems include both electrochemical capacitors and electrostatic capacitors. These devices have fast charging and discharging rates, supplying energy within seconds or less. Recent research has focused on increasing power and energy density of the devices using advanced materials and novel architectural design. An increase in understanding of structure-property relationships in nanomaterials and interfaces and the ability to control nanostructures precisely has led to an immense improvement in the performance characteristics of these devices. In this review, we discuss the recent advances for both electrochemical and electrostatic capacitors as high power electrical energy storage systems, and propose directions and challenges for the future. We asses the opportunities in nanostructure-based high power electrical energy storage devices and include electrochemical and electrostatic capacitors for their potential to open the door to a new regime of power energy.

  16. Motor unit recruitment during neuromuscular electrical stimulation: a critical appraisal.

    Science.gov (United States)

    Bickel, C Scott; Gregory, Chris M; Dean, Jesse C

    2011-10-01

    Neuromuscular electrical stimulation (NMES) is commonly used in clinical settings to activate skeletal muscle in an effort to mimic voluntary contractions and enhance the rehabilitation of human skeletal muscles. It is also used as a tool in research to assess muscle performance and/or neuromuscular activation levels. However, there are fundamental differences between voluntary- and artificial-activation of motor units that need to be appreciated before NMES protocol design can be most effective. The unique effects of NMES have been attributed to several mechanisms, most notably, a reversal of the voluntary recruitment pattern that is known to occur during voluntary muscle contractions. This review outlines the assertion that electrical stimulation recruits motor units in a nonselective, spatially fixed, and temporally synchronous pattern. Additionally, it synthesizes the evidence that supports the contention that this recruitment pattern contributes to increased muscle fatigue when compared with voluntary actions and provides some commentary on the parameters of electrical stimulation as well as emerging technologies being developed to facilitate NMES implementation. A greater understanding of how electrical stimulation recruits motor units, as well as the benefits and limitations of its use, is highly relevant when using this tool for testing and training in rehabilitation, exercise, and/or research.

  17. High critical magnetic field superconductor La3S4

    International Nuclear Information System (INIS)

    Westerholt, K.; Bach, H.; Wendemuth, R.; Methfessel, S.

    1979-01-01

    A report is presented on electrical conductivity, specific heat and magnetization measurements on La 3 S 4 single crystals. The results show that La 3 S 4 is a strong coupling superconductor with a BCS coherence length of 132 A. This extremely low value makes La 3 S 4 an intrinsic high critical magnetic field superconductor with a Landau-Ginsburg parameter of 20. For the temperature gradient of the upper critical magnetic field at the transition temperature values are found up to 35 kG/K. (author)

  18. Critical fields in high temperature superconductors

    International Nuclear Information System (INIS)

    Finnemore, D.K.

    1991-01-01

    An analysis of various methods to obtain the critical fields of the high temperature superconductors from experimental data is undertaken in order to find definitions of these variables that are consistent with the models used to define them. Characteristic critical fields of H c1 , H c2 and H c that occur in the Ginsburg-Landau theory are difficult to determine experimentally in the high temperature superconductors because there are additional physical phenomena that obscure the results. The lower critical field is difficult to measure because there are flux pinning and surface barrier effects to flux entry; the upper critical field is difficult because fluctuation effects are large at this phase boundary; the thermodynamic critical field is difficult because fluctuations make it difficult to know the field where the magnetization integral should be terminated. In addition to these critical fields there are at least two other cross-over fields. There is the so called irreversibility line where the vortices transform from a rigid flux line lattice to a fluid lattice and there is a second cross-over field associated with the transition from the fluctuation to the Abrikosov vortex regime. The presence of these new physical effects may require new vocabulary

  19. Identification and Ranking of Critical Assets within an Electrical Grid under Threat of Cyber Attack

    Science.gov (United States)

    Boyer, Blake R.

    This paper examines the ranking of critical assets within an electrical grid under threat of cyber attack.1 Critical to this analysis is the assumption of zero hour exploits namely, the threat of an immediate attack as soon as a vulnerability is discovered. Modeling shows that over time load fluctuations as well as other system variations will change the importance of each asset in the delivery of bulk power. As opposed to classic stability studies where risk can be shown to be greatest during high load periods, the zero hour exploit-cyber-risk assumes that vulnerabilities will be attacked as soon as they are discovered. The probability of attacks is made uniform over time to include any and all possible attacks. Examining the impact of an attack and how the grid reacts immediately following an attack will identify and determine the criticality of each asset. This work endeavors to fulfill the NERC Critical Infrastructure Protection Requirements CIP-001-1 through CIP-009-2, cyber security requirements for the reliable supply of bulk power to customers throughout North America. 1Critical assets will here refer to facilities, systems, and equipment, which, if destroyed, degraded, or otherwise rendered unavailable, would affect the reliability or operability of the Bulk Electric System, NERC Glossary of Terms Used in Reliability Standards, 2009

  20. Electrical access to critical coupling of circularly polarized waves in graphene chiral metamaterials.

    Science.gov (United States)

    Kim, Teun-Teun; Oh, Sang Soon; Kim, Hyeon-Don; Park, Hyun Sung; Hess, Ortwin; Min, Bumki; Zhang, Shuang

    2017-09-01

    Active control of polarization states of electromagnetic waves is highly desirable because of its diverse applications in information processing, telecommunications, and spectroscopy. However, despite the recent advances using artificial materials, most active polarization control schemes require optical stimuli necessitating complex optical setups. We experimentally demonstrate an alternative-direct electrical tuning of the polarization state of terahertz waves. Combining a chiral metamaterial with a gated single-layer sheet of graphene, we show that transmission of a terahertz wave with one circular polarization can be electrically controlled without affecting that of the other circular polarization, leading to large-intensity modulation depths (>99%) with a low gate voltage. This effective control of polarization is made possible by the full accessibility of three coupling regimes, that is, underdamped, critically damped, and overdamped regimes by electrical control of the graphene properties.

  1. Critical current enhancement in high Tc superconductors

    International Nuclear Information System (INIS)

    Jin, S.; Graebner, J.E.; Tiefel, T.H.

    1990-01-01

    Progress toward major technological applications of the bulk, high T c superconductors has been hindered by two major barriers, i.e., the Josephson weak-links at grain boundaries and the lack of sufficient intragrain flux pinning. It has been demonstrated that the weak link problem can be overcome by extreme alignment of grains such as in melt-textured-growth (MTG) materials. Modified or improved processing by various laboratories has produced further increased critical currents. However, the insufficient flux pinning seems to limit the critical current density in high fields to about 10 4 --10 5 A/cm 2 at 77K, which is not satisfactory for many applications. In this paper, processing, microstructure, and critical current behavior of the MTG type superconductors are described, and various processing possibilities for flux pinning enhancement are discussed

  2. Electric field obtained from an elliptic critical-state model for anisotropic type-II superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Romero-Salazar, C., E-mail: cromeros@ifuap.buap.mx; Hernández-Flores, O.A.

    2016-02-15

    Highlights: • An anisotropic critical state model that incorporates a non-zero electric field is proposed. • The critical current density is driven by the electric field. • To determinate the magnetic properties is not required a material law for the electric field magnitude. - Abstract: The conventional elliptic critical-state models (ECSM) establish that the electric field vector is zero when it flows a critical current density in a type-II superconductor. This proposal incorporates a finite electric field on the ECSM to study samples with anisotropic-current-carrying capacity. Our theoretical scheme has the advantage of being able to dispense of a material law which drives the electric field magnitude, however, it does not consider the magnetic history of the superconductor.

  3. Design of very high speed electric generators

    International Nuclear Information System (INIS)

    Labollita, Santiago

    2008-01-01

    This work approaches the design process of an electric generator suitable for running efficiently at high speed, driven by a turbo shaft.The axial flux concept was used.For the mechanical design of the prototype, cooling capacity and mounting method were considered, looking for simplicity of the parts evolved. Neodymium-iron-boron permanent magnets were used as magnetic source.For the electrical design, a calculation tool was developed in order to predict the prototype electrical parameters and optimize its geometry.The goal was to obtain 1 kW of electric power at a speed of 100,000 rpm.The efficiency and electrical behaviour of the prototype were characterized at speeds between 2,000 rpm and 30,000 rpm and then the behaviour at the design condition was predicted by obtaining an equivalent electric circuit.The estimated load voltage was 237 V as well as an electrical efficiency of 95%.Eddy current effects were not recognized. Increase of the internal resistance and decree of inductance were observed while raising the electric frequency.Finally, an electronic system was developed in order to use the prototype as a c.c. motor. Global performance was measured according to different supply characteristic. An optimum supply voltage was found.A maximum efficiency of 63% was reached. [es

  4. Moderate and high intensity pulsed electric fields

    OpenAIRE

    Timmermans, Rian Adriana Hendrika

    2018-01-01

    Pulsed Electric Field (PEF) processing has gained a lot of interest the last decades as mild processing technology as alternative to thermal pasteurisation, and is suitable for preservation of liquid food products such as fruit juices. PEF conditions typically applied at industrial scale for pasteurisation are high intensity pulsed electric fields aiming for minimal heat load, with an electric field strength (E) in the range of 15 − 20 kV/cm and pulse width (τ) between 2 − 20 μs. Alternativel...

  5. Weak links in high critical temperature superconductors

    Science.gov (United States)

    Tafuri, Francesco; Kirtley, John R.

    2005-11-01

    The traditional distinction between tunnel and highly transmissive barriers does not currently hold for high critical temperature superconducting Josephson junctions, both because of complicated materials issues and the intrinsic properties of high temperature superconductors (HTS). An intermediate regime, typical of both artificial superconductor-barrier-superconductor structures and of grain boundaries, spans several orders of magnitude in the critical current density and specific resistivity. The physics taking place at HTS surfaces and interfaces is rich, primarily because of phenomena associated with d-wave order parameter (OP) symmetry. These phenomena include Andreev bound states, the presence of the second harmonic in the critical current versus phase relation, a doubly degenerate state, time reversal symmetry breaking and the possible presence of an imaginary component of the OP. All these effects are regulated by a series of transport mechanisms, whose rules of interplay and relative activation are unknown. Some transport mechanisms probably have common roots, which are not completely clear and possibly related to the intrinsic nature of high-TC superconductivity. The d-wave OP symmetry gives unique properties to HTS weak links, which do not have any analogy with systems based on other superconductors. Even if the HTS structures are not optimal, compared with low critical temperature superconductor Josephson junctions, the state of the art allows the realization of weak links with unexpectedly high quality quantum properties, which open interesting perspectives for the future. The observation of macroscopic quantum tunnelling and the qubit proposals represent significant achievements in this direction. In this review we attempt to encompass all the above aspects, attached to a solid experimental basis of junction concepts and basic properties, along with a flexible phenomenological background, which collects ideas on the Josephson effect in the presence

  6. Weak links in high critical temperature superconductors

    International Nuclear Information System (INIS)

    Tafuri, Francesco; Kirtley, John R

    2005-01-01

    The traditional distinction between tunnel and highly transmissive barriers does not currently hold for high critical temperature superconducting Josephson junctions, both because of complicated materials issues and the intrinsic properties of high temperature superconductors (HTS). An intermediate regime, typical of both artificial superconductor-barrier-superconductor structures and of grain boundaries, spans several orders of magnitude in the critical current density and specific resistivity. The physics taking place at HTS surfaces and interfaces is rich, primarily because of phenomena associated with d-wave order parameter (OP) symmetry. These phenomena include Andreev bound states, the presence of the second harmonic in the critical current versus phase relation, a doubly degenerate state, time reversal symmetry breaking and the possible presence of an imaginary component of the OP. All these effects are regulated by a series of transport mechanisms, whose rules of interplay and relative activation are unknown. Some transport mechanisms probably have common roots, which are not completely clear and possibly related to the intrinsic nature of high-T C superconductivity. The d-wave OP symmetry gives unique properties to HTS weak links, which do not have any analogy with systems based on other superconductors. Even if the HTS structures are not optimal, compared with low critical temperature superconductor Josephson junctions, the state of the art allows the realization of weak links with unexpectedly high quality quantum properties, which open interesting perspectives for the future. The observation of macroscopic quantum tunnelling and the qubit proposals represent significant achievements in this direction. In this review we attempt to encompass all the above aspects, attached to a solid experimental basis of junction concepts and basic properties, along with a flexible phenomenological background, which collects ideas on the Josephson effect in the presence

  7. Time Lapse Electrical Resistivity to Connect Evapotranspiration and Groundwater Fluxes in the Critical Zone

    Science.gov (United States)

    Jarvis, S. K.; Harmon, R. E.; Barnard, H. R.; Randall, J.; Singha, K.

    2017-12-01

    The critical zone (CZ)—an open system extending from canopy top to the base of groundwater—is a highly dynamic and heterogeneous environment. In forested terrain, trees make up a large component of the CZ. This work aims to quantify the connection between vegetation and subsurface water storage at a hillslope scale within a forested watershed in the H.J. Andrews Experimental Forest, Oregon. To identify the mechanism(s) controlling the connection at the hillslope scale, we observe patterns in electrical conductivity using 2D-time lapse-DC resistivity. To compare inversions through time a representative error model was determined using L-curve criterion. Inverted data show high spatial variability in ground electrical conductivity and variation at both diel and seasonal timescales. These changes are most pronounced in areas corresponding to dense vegetation. The diel pattern in electrical conductivity is also observed in monitored sap flow sensors, water-level gauges, tensiometers, and sediment thermal probes. To quantify the temporal connection between these data over the course of the growing season a cross correlation analysis was conducted. Preliminary data show that over the course of the growing season transpiration becomes decoupled from both groundwater and soil moisture. Further decomposition of the inverted time lapse data will highlight spatial variability in electrical conductivity providing insight into the where, when, and how(s) of tree-modified subsurface storage.

  8. Molecular dynamics in high electric fields

    International Nuclear Information System (INIS)

    Apostol, M.; Cune, L.C.

    2016-01-01

    Highlights: • New method for rotation molecular spectra in high electric fields. • Parametric resonances – new features in spectra. • New elementary excitations in polar solids from dipolar interaction (“dipolons”). • Discussion about a possible origin of the ferroelectricity from dipolar interactions. - Abstract: Molecular rotation spectra, generated by the coupling of the molecular electric-dipole moments to an external time-dependent electric field, are discussed in a few particular conditions which can be of some experimental interest. First, the spherical-pendulum molecular model is reviewed, with the aim of introducing an approximate method which consists in the separation of the azimuthal and zenithal motions. Second, rotation spectra are considered in the presence of a static electric field. Two particular cases are analyzed, corresponding to strong and weak fields. In both cases the classical motion of the dipoles consists of rotations and vibrations about equilibrium positions; this motion may exhibit parametric resonances. For strong fields a large macroscopic electric polarization may appear. This situation may be relevant for polar matter (like pyroelectrics, ferroelectrics), or for heavy impurities embedded in a polar solid. The dipolar interaction is analyzed in polar condensed matter, where it is shown that new polarization modes appear for a spontaneous macroscopic electric polarization (these modes are tentatively called “dipolons”); one of the polarization modes is related to parametric resonances. The extension of these considerations to magnetic dipoles is briefly discussed. The treatment is extended to strong electric fields which oscillate with a high frequency, as those provided by high-power lasers. It is shown that the effect of such fields on molecular dynamics is governed by a much weaker, effective, renormalized, static electric field.

  9. Electricity under the critical scrutiny of parliament and the people

    International Nuclear Information System (INIS)

    1982-01-01

    The history of electricity power generation in Switzerland over the last hundred years is examined from the point of view of its social and political implications. Particular attention is paid to the forthcoming decision by parliament regarding the construction of a new atomic power station at Kaiseraugst in view of the increasing anti-nuclear energy lobby in Switzerland itself and in West Germany to whom considerable quantities of electricity are ''exported''. (R.S.)

  10. Analyzing the topological, electrical and reliability characteristics of a power transmission system for identifying its critical elements

    International Nuclear Information System (INIS)

    Zio, E.; Golea, L.R.

    2012-01-01

    The subject of this paper is the analysis of an electrical transmission system with the objective of identifying its most critical elements with respect to failures and attacks. The methodological approach undertaken is based on graph-theoretical (topological) network analysis. Four different perspectives of analysis are considered within the formalism of weighed networks, adding to the purely topological analysis of the system, the reliability and electrical characteristics of its components. In each phase of the analysis: i) a graph-theoretical representation is offered to highlight the structure of the most important system connections according to the particular characteristics examined (topological, reliability, electrical or electrical-reliability), ii) the classical degree index of a network node is extended to account for the different characteristics considered. The application of these concepts of analysis to an electrical transmission system of literature confirms the importance of different perspectives of analysis on such a critical infrastructure. - Highlights: ► We analyze a power system from topological, reliability and electrical perspectives. ► We rank critical components within a vulnerability assessment framework. ► We compute an extended degree to rank critical energy paths. ► We compare several analytical approaches and provide a table for choosing among them. ► We suggest network changes to increase the reliability of highly loaded energy paths.

  11. High thermal conductivity connector having high electrical isolation

    Science.gov (United States)

    Nieman, Ralph C.; Gonczy, John D.; Nicol, Thomas H.

    1995-01-01

    A method and article for providing a low-thermal-resistance, high-electrical-isolation heat intercept connection. The connection method involves clamping, by thermal interference fit, an electrically isolating cylinder between an outer metallic ring and an inner metallic disk. The connection provides durable coupling of a heat sink and a heat source.

  12. Critical Infrastructure Protection: EMP Impacts on the U.S. Electric Grid

    Science.gov (United States)

    Boston, Edwin J., Jr.

    The purpose of this research is to identify the United States electric grid infrastructure systems vulnerabilities to electromagnetic pulse attacks and the cyber-based impacts of those vulnerabilities to the electric grid. Additionally, the research identifies multiple defensive strategies designed to harden the electric grid against electromagnetic pulse attack that include prevention, mitigation and recovery postures. Research results confirm the importance of the electric grid to the United States critical infrastructures system and that an electromagnetic pulse attack against the electric grid could result in electric grid degradation, critical infrastructure(s) damage and the potential for societal collapse. The conclusions of this research indicate that while an electromagnetic pulse attack against the United States electric grid could have catastrophic impacts on American society, there are currently many defensive strategies under consideration designed to prevent, mitigate and or recover from an electromagnetic pulse attack. However, additional research is essential to further identify future target hardening opportunities, efficient implementation strategies and funding resources.

  13. Identifying groups of critical edges in a realistic electrical network by multi-objective genetic algorithms

    International Nuclear Information System (INIS)

    Zio, E.; Golea, L.R.; Rocco S, C.M.

    2012-01-01

    In this paper, an analysis of the vulnerability of the Italian high-voltage (380 kV) electrical transmission network (HVIET) is carried out for the identification of the groups of links (or edges, or arcs) most critical considering the network structure and flow. Betweenness centrality and network connection efficiency variations are considered as measures of the importance of the network links. The search of the most critical ones is carried out within a multi-objective optimization problem aimed at the maximization of the importance of the groups and minimization of their dimension. The problem is solved using a genetic algorithm. The analysis is based only on information on the topology of the network and leads to the identification of the most important single component, couples of components, triplets and so forth. The comparison of the results obtained with those reported by previous analyses indicates that the proposed approach provides useful complementary information.

  14. Electromagnetic waves destabilized by runaway electrons in near-critical electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Komar, A.; Pokol, G. I. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); Fueloep, T. [Department of Applied Physics, Nuclear Engineering, Chalmers University of Technology and Euratom-VR Association, Goeteborg (Sweden)

    2013-01-15

    Runaway electron distributions are strongly anisotropic in velocity space. This anisotropy is a source of free energy that may destabilize electromagnetic waves through a resonant interaction between the waves and the energetic electrons. In this work, we investigate the high-frequency electromagnetic waves that are destabilized by runaway electron beams when the electric field is close to the critical field for runaway acceleration. Using a runaway electron distribution appropriate for the near-critical case, we calculate the linear instability growth rate of these waves and conclude that the obliquely propagating whistler waves are most unstable. We show that the frequencies, wave numbers, and propagation angles of the most unstable waves depend strongly on the magnetic field. Taking into account collisional and convective damping of the waves, we determine the number density of runaways that is required to destabilize the waves and show its parametric dependences.

  15. Progress in electrical energy storage system:A critical review

    Institute of Scientific and Technical Information of China (English)

    Haisheng Chen; Thang Ngoc Cong; Wei Yang; Chunqing Tan; Yongliang Li; Yulong Ding

    2009-01-01

    Electrical energy storage technologies for stationary applications are reviewed.Particular attention is paid to pumped hydroelectric storage,compressed air energy storage,battery,flow battery,fuel cell,solar fuel,superconducting magnetic energy storage, flywheel, capacitor/supercapacitor,and thermal energy torage.Comparison is made among these technologies in terms of technical characteris-tics,applications and deployment status.

  16. High slot utilization systems for electric machines

    Science.gov (United States)

    Hsu, John S

    2009-06-23

    Two new High Slot Utilization (HSU) Systems for electric machines enable the use of form wound coils that have the highest fill factor and the best use of magnetic materials. The epoxy/resin/curing treatment ensures the mechanical strength of the assembly of teeth, core, and coils. In addition, the first HSU system allows the coil layers to be moved inside the slots for the assembly purpose. The second system uses the slided-in teeth instead of the plugged-in teeth. The power density of the electric machine that uses either system can reach its highest limit.

  17. Silicon Photomultiplier Performance in High ELectric Field

    Science.gov (United States)

    Montoya, J.; Morad, J.

    2016-12-01

    Roughly 27% of the universe is thought to be composed of dark matter. The Large Underground Xenon (LUX) relies on the emission of light from xenon atoms after a collision with a dark matter particle. After a particle interaction in the detector, two things can happen: the xenon will emit light and charge. The charge (electrons), in the liquid xenon needs to be pulled into the gas section so that it can interact with gas and emit light. This allows LUX to convert a single electron into many photons. This is done by applying a high voltage across the liquid and gas regions, effectively ripping electrons out of the liquid xenon and into the gas. The current device used to detect photons is the photomultiplier tube (PMT). These devices are large and costly. In recent years, a new technology that is capable of detecting single photons has emerged, the silicon photomultiplier (SiPM). These devices are cheaper and smaller than PMTs. Their performance in a high electric fields, such as those found in LUX, are unknown. It is possible that a large electric field could introduce noise on the SiPM signal, drowning the single photon detection capability. My hypothesis is that SiPMs will not observe a significant increase is noise at an electric field of roughly 10kV/cm (an electric field within the range used in detectors like LUX). I plan to test this hypothesis by first rotating the SiPMs with no applied electric field between two metal plates roughly 2 cm apart, providing a control data set. Then using the same angles test the dark counts with the constant electric field applied. Possibly the most important aspect of LUX, is the photon detector because it's what detects the signals. Dark matter is detected in the experiment by looking at the ratio of photons to electrons emitted for a given interaction in the detector. Interactions with a low electron to photon ratio are more like to be dark matter events than those with a high electron to photon ratio. The ability to

  18. High voltage electricity installations a planning perspective

    CERN Document Server

    Jay, Stephen Andrew

    2006-01-01

    The presence of high voltage power lines has provoked widespread concern for many years. High Voltage Electricity Installations presents an in-depth study of policy surrounding the planning of high voltage installations, discussing the manner in which they are percieved by the public, and the associated environmental issues. An analysis of these concerns, along with the geographical, environmental and political influences that shape their expression, is presented. Investigates local planning policy in an area of the energy sector that is of highly topical environmental and public concern Cover

  19. An exploratory analysis of California residential customer response to critical peak pricing of electricity

    International Nuclear Information System (INIS)

    Herter, Karen; McAuliffe, Patrick; Rosenfeld, Arthur

    2007-01-01

    This paper summarizes the results from an exploratory analysis of residential customer response to a critical peak pricing (CPP) experiment in California, in which 15 times per year participating customers received high price signals dispatched by a local electricity distribution company. The high prices were about three times the on-peak price for the otherwise applicable time-of-use rate. Using hourly load data collected during the 15-month experiment, we find statistically significant load reduction for participants both with and without automated end-use control technologies. During 5-h critical peak periods, participants without control technology used up to 13% less energy than they did during normal peak periods. Participants equipped with programmable communicating thermostats used 25% and 41% less for 5 and 2h critical events, respectively. Thus, this paper offers convincing evidence that the residential sector can provide substantial contributions to retail demand response, which is considered a potential tool for mitigating market power, stabilizing wholesale market prices, managing system reliability, and maintaining system resource adequacy. (author)

  20. Electric field effect on the critical current of SNS-contact

    International Nuclear Information System (INIS)

    Rakhmanov, A.L.; Rozhkov, A.V.

    1995-01-01

    Electric field effect on the SNS-contact critical current is investigated in the Ginzburg-Landau theory approximation. It is shown that the electric field may cause a notable increase of the contact critical current especially if the sample temperature is close to the temperature of a superconducting transition of T sc normal layer. Electric field effect is increased with the reduction of film thickness, but it can strong enough for thick films as well at temperature close to T sc . 11 refs.; 4 figs

  1. Natural gas : a critical component of Ontario's electricity future

    International Nuclear Information System (INIS)

    Pleckaitis, A.

    2004-01-01

    This PowerPoint presentation identified natural gas as part of the electricity solution. It reviewed price implications and policy recommendations. New natural gas supply is not keeping pace with demand. Production is leveling out in traditional basins and industry investment is not adequate. In addition, energy deregulation is creating disconnects. This presentation included a map depicting the abundant natural gas reserves across North America. It was noted that at 2002 levels of domestic production, North America has approximately 80 years of natural gas. The AECO consensus wholesale natural gas price forecast is that natural gas prices in 2010 will be lower than today. The use of natural gas for power generation was outlined with reference to fuel switching, distributed generation, and central generation. It was emphasized that government, regulators and the energy industry must work together to address policy gaps and eliminate barriers to new investment. tabs., figs

  2. High-Tc superconducting electric motors

    International Nuclear Information System (INIS)

    Schiferl, R.; Stein, J.

    1992-01-01

    In this paper, the advantages and limitations of using superconductors in motors are discussed. A synchronous motor with a high temperature superconducting field winding for pump and fan drive applications is described and some of its unique design features are identified. A 10,000 horsepower superconducting motor design is presented. The critical field and current density requirements for high temperature superconducting wire in motors is discussed. Finally, recent progress in superconducting wire performance is presented

  3. Non-critical strings at high energy

    CERN Document Server

    Aoki, Kenichiro; Aoki, Kenichiro; Hoker, Eric D'

    1996-01-01

    We consider scattering amplitudes in non-critical string theory of $N$ external states in the limit where the energy of all external states is large compared to the string tension. We argue that the amplitudes are naturally complex analytic in the matter central charge $c$ and we propose to define the amplitudes for arbitrary value of $c$ by analytic continuation. We show that the high energy limit is dominated by a saddle point that can be mapped onto an equilibrium electro-static energy configuration of an assembly of $N$ pointlike (Minkowskian) charges, together with a density of charges arising from the Liouville field. We argue that the Liouville charges accumulate on segments of curves, and produce quadratic branch cuts on the worldsheet. The electro-statics problem is solved for string tree level in terms of hyper-elliptic integrals and is given explicitly for 3- and 4-point functions. We show that the high energy limit should behave in a string-like fashion with exponential dependence on the energy sc...

  4. Electrical characteristics of high density, high purity titanate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Lupfer, D A [Electronics Laboratory, General Electric Company, Syracuse, NY (United States)

    1958-07-01

    This report is concerned with the electrical behaviour of cubic (Ba,Sr)TiO{sub 3} ceramics at very high values of the electric field. The work was undertaken to develop a dielectric system to be used in capacitors for the storage and discharge of electrical energy. Objectives for the finished system were to store large amounts of energy per unit volume, to release at least 75% of the energy in 0.2 x 10{sup -6} seconds, and to operate over a limited temperature range above 20 deg. C. The work is incomplete, but the results to date show that (Ba,Sr) TiO{sub 3} ceramics can store more electrical energy per unit volume than any other known dielectric system.

  5. Privatization of British electricity supply industry: Critical analysis

    International Nuclear Information System (INIS)

    Cervigni, G.

    1993-01-01

    Until 1989, despite the partially disintegrated organization of the British electricity supply industry (ESI) and the attempt of the Energy Act of 1983 to pull down entrance barriers to the power generation business, ESI operated like an integrated monopoly. Between 1989 and 1990, ESI has been subjected to a reorganization process and transfer to the private sector with the declared aim of improving short and long run micro-economic efficiency. For this purpose, the attempt of introducing competition in the phases of the production process where possible and of regulating those which are structurally non competitive, has been made. The new configuration of ESI in terms of organizational structure, property regime and regulatory system is analyzed. Areas of improvement of the regulatory system and delayed key decisions of the public operator, are identified. However, any evaluation of the process as a whole can only relate to a minor part of the present situation; thus it subtends a scenary for the future, where the role of the regulatory authority is crucial

  6. High-throughput electrical characterization for robust overlay lithography control

    Science.gov (United States)

    Devender, Devender; Shen, Xumin; Duggan, Mark; Singh, Sunil; Rullan, Jonathan; Choo, Jae; Mehta, Sohan; Tang, Teck Jung; Reidy, Sean; Holt, Jonathan; Kim, Hyung Woo; Fox, Robert; Sohn, D. K.

    2017-03-01

    Realizing sensitive, high throughput and robust overlay measurement is a challenge in current 14nm and advanced upcoming nodes with transition to 300mm and upcoming 450mm semiconductor manufacturing, where slight deviation in overlay has significant impact on reliability and yield1). Exponentially increasing number of critical masks in multi-patterning lithoetch, litho-etch (LELE) and subsequent LELELE semiconductor processes require even tighter overlay specification2). Here, we discuss limitations of current image- and diffraction- based overlay measurement techniques to meet these stringent processing requirements due to sensitivity, throughput and low contrast3). We demonstrate a new electrical measurement based technique where resistance is measured for a macro with intentional misalignment between two layers. Overlay is quantified by a parabolic fitting model to resistance where minima and inflection points are extracted to characterize overlay control and process window, respectively. Analyses using transmission electron microscopy show good correlation between actual overlay performance and overlay obtained from fitting. Additionally, excellent correlation of overlay from electrical measurements to existing image- and diffraction- based techniques is found. We also discuss challenges of integrating electrical measurement based approach in semiconductor manufacturing from Back End of Line (BEOL) perspective. Our findings open up a new pathway for accessing simultaneous overlay as well as process window and margins from a robust, high throughput and electrical measurement approach.

  7. Evaluation of Electric Vehicle Charging Controllability for Provision of Time Critical Grid Services

    DEFF Research Database (Denmark)

    Martinenas, Sergejus; Marinelli, Mattia; Andersen, Peter Bach

    2016-01-01

    Replacement of conventional generation by more stochastic renewable generation sources leads to reduction of inertia and controllability in the power system. This introduces the need for more dynamic regulation services. These faster services could potentially be provided by the growing number...... of electric vehicles. EVs are a fast responding energy resource with high availability. This work evaluates and experimentally shows the limits of EV charging controllability with the focus on its suitability for providing ancillary grid services. Three different series produced EVs are tested....... The experimental testing is done by using charging current controllability of built-in AC charger to provide a primary frequency regulation service with very dynamic input frequency. The results show that most the controllability of most EVs is more than suitable for providing time critical grid services...

  8. High prices on electric power now again?

    International Nuclear Information System (INIS)

    Doorman, Gerard

    2003-01-01

    Deregulation of the electric power market has yielded low prices for the consumers throughout the 1990s. Consumption has now increased considerably, but little new production has been added. This results in high prices in dry years, but to understand this one must understand price formation in the Nordic spot market. The high prices are a powerful signal to the consumers to reduce consumption, but they are also a signal to the producers to seize any opportunity to increase production. However, the construction of new dams etc. stirs up the environmentalists. Ordinary consumers may protect themselves against high prices by signing fixed-price contracts. For those who can tolerate price fluctuations, spot prices are a better alternative than the standard contract with variable price

  9. Thermal conductivity in high critical temperature superconductors

    International Nuclear Information System (INIS)

    Castello, D.J.

    1990-01-01

    A measuring procedure to obtain the electrical resistivity, thermal conductivity and thermoelectric power of samples of low conductivity has been developed. The setup was designed to allow the removal of the sample in clean fashion, so that further heat treatments could be performed, and therefore no adhesives were used in the mounting of the thermocouples or heat sinks, etc. The heat equation has been analyzed with time-dependent boundary conditions, with the purpose of developing a dynamic measuring method which avoids the long delays involved in reaching thermal equilibrium above 30K. Based on this analysis, the developed measuring method allows a precise and reliable measurements, in a continuous fashion, for temperatures above 25K. The same setup is used in a stationary mode at low temperatures, so the sample needs to be mounted only once. κ(T) has been measured in two ceramic samples of La 2 CuO 4 : the first semiconducting, the other superconducting (SC) as a consequence of an oxygen annealing. Both exhibit a strong thermal resistivity due to defects, though lower in the SC, where two maxima are observed and are attributed to an AF ordering: T N ' ≅ 40K and T N '' ≅ 240K. The low temperature dependence is T 1 .6 and T 2 .3 respectively. It was interpreted that the former sample presents a greater dispersion due to localized excitations, characteristic of amorphouus materials, 'tunneling two-level systems' (TS). A third syntherized sample of CuO exhibits a typical behaviour of an insulator, with T 2 .6 at low temperatures, a maximum at 40K and a decrease in T -1 at high temperatures. κ(T) in a SC sample of La 1 .85Sr 1 .15CuO 4 with T c =35.5K has also been measured, observing a small increase below T c because of the diminishing of the phonon dispersion due to the condensating electrons. κ(T) is lower than in the previous samples and thus a greater number of defects was inferred. At low temperatures, its dependence is T 1 .4 in agreement with the

  10. New approaches to provide ride-through for critical loads in electric power distribution systems

    Science.gov (United States)

    Montero-Hernandez, Oscar C.

    2001-07-01

    The extensive use of electronic circuits has enabled modernization, automation, miniaturization, high quality, low cost, and other achievements regarding electric loads in the last decades. However, modern electronic circuits and systems are extremely sensitive to disturbances from the electric power supply. In fact, the rate at which these disturbances happen is considerable as has been documented in recent years. In response to the power quality concerns presented previously, this dissertation is proposing new approaches to provide ride-through for critical loads during voltage disturbances with emphasis on voltage sags. In this dissertation, a new approach based on an AC-DC-AC system is proposed to provide ride-through for critical loads connected in buildings and/or an industrial system. In this approach, a three-phase IGBT inverter with a built in Dc-link voltage regulator is suitably controlled along with static by-pass switches to provide continuous power to critical loads. During a disturbance, the input utility source is disconnected and the power from the inverter is connected to the load. The remaining voltage in the AC supply is converted to DC and compensated before being applied to the inverter and the load. After detecting normal utility conditions, power from the utility is restored to the critical load. In order to achieve an extended ride-through capability a second approach is introduced. In this case, the Dc-link voltage regulator is performed by a DC-DC Buck-Boost converter. This new approach has the capability to mitigate voltage variations below and above the nominal value. In the third approach presented in this dissertation, a three-phase AC to AC boost converter is investigated. This converter provides a boosting action for the utility input voltages, right before they are applied to the load. The proposed Pulse Width Modulation (PWM) control strategy ensures independent control of each phase and compensates for both single-phase or poly

  11. A critical survey of agent-based wholesale electricity market models

    International Nuclear Information System (INIS)

    Weidlich, Anke; Veit, Daniel

    2008-01-01

    The complexity of electricity markets calls for rich and flexible modeling techniques that help to understand market dynamics and to derive advice for the design of appropriate regulatory frameworks. Agent-Based Computational Economics (ACE) is a fairly young research paradigm that offers methods for realistic electricity market modeling. A growing number of researchers have developed agent-based models for simulating electricity markets. The diversity of approaches makes it difficult to overview the field of ACE electricity research; this literature survey should guide the way through and describe the state-of-the-art of this research area. In a conclusive summary, shortcomings of existing approaches and open issues that should be addressed by ACE electricity researchers are critically discussed. (author)

  12. Electric field measurements in high pressure discharges

    International Nuclear Information System (INIS)

    Mitko, S.V.; Ochkin, V.N.; Serdyuchenko, A.Yu.; Tskhai, S.N.

    2001-01-01

    Electric fields define a wide range of interactions and phenomena at different phases of matter both on micro- and macro-level. Investigation of electric fields behavior provides a key for understanding of these phenomena and their application

  13. High temperature electrical energy storage: advances, challenges, and frontiers.

    Science.gov (United States)

    Lin, Xinrong; Salari, Maryam; Arava, Leela Mohana Reddy; Ajayan, Pulickel M; Grinstaff, Mark W

    2016-10-24

    With the ongoing global effort to reduce greenhouse gas emission and dependence on oil, electrical energy storage (EES) devices such as Li-ion batteries and supercapacitors have become ubiquitous. Today, EES devices are entering the broader energy use arena and playing key roles in energy storage, transfer, and delivery within, for example, electric vehicles, large-scale grid storage, and sensors located in harsh environmental conditions, where performance at temperatures greater than 25 °C are required. The safety and high temperature durability are as critical or more so than other essential characteristics (e.g., capacity, energy and power density) for safe power output and long lifespan. Consequently, significant efforts are underway to design, fabricate, and evaluate EES devices along with characterization of device performance limitations such as thermal runaway and aging. Energy storage under extreme conditions is limited by the material properties of electrolytes, electrodes, and their synergetic interactions, and thus significant opportunities exist for chemical advancements and technological improvements. In this review, we present a comprehensive analysis of different applications associated with high temperature use (40-200 °C), recent advances in the development of reformulated or novel materials (including ionic liquids, solid polymer electrolytes, ceramics, and Si, LiFePO 4 , and LiMn 2 O 4 electrodes) with high thermal stability, and their demonstrative use in EES devices. Finally, we present a critical overview of the limitations of current high temperature systems and evaluate the future outlook of high temperature batteries with well-controlled safety, high energy/power density, and operation over a wide temperature range.

  14. Empirical high-latitude electric field models

    International Nuclear Information System (INIS)

    Heppner, J.P.; Maynard, N.C.

    1987-01-01

    Electric field measurements from the Dynamics Explorer 2 satellite have been analyzed to extend the empirical models previously developed from dawn-dusk OGO 6 measurements (J.P. Heppner, 1977). The analysis embraces large quantities of data from polar crossings entering and exiting the high latitudes in all magnetic local time zones. Paralleling the previous analysis, the modeling is based on the distinctly different polar cap and dayside convective patterns that occur as a function of the sign of the Y component of the interplanetary magnetic field. The objective, which is to represent the typical distributions of convective electric fields with a minimum number of characteristic patterns, is met by deriving one pattern (model BC) for the northern hemisphere with a +Y interplanetary magnetic field (IMF) and southern hemisphere with a -Y IMF and two patterns (models A and DE) for the northern hemisphere with a -Y IMF and southern hemisphere with a +Y IMF. The most significant large-scale revisions of the OGO 6 models are (1) on the dayside where the latitudinal overlap of morning and evening convection cells reverses with the sign of the IMF Y component, (2) on the nightside where a westward flow region poleward from the Harang discontinuity appears under model BC conditions, and (3) magnetic local time shifts in the positions of the convection cell foci. The modeling above was followed by a detailed examination of cases where the IMF Z component was clearly positive (northward). Neglecting the seasonally dependent cases where irregularities obscure pattern recognition, the observations range from reasonable agreement with the new BC and DE models, to cases where different characteristics appeared primarily at dayside high latitudes

  15. Thermalhydraulic behavior of electrically heated rod during a critical heat flux transient

    International Nuclear Information System (INIS)

    Lima, Rita de Cassia Fernandes de; Carajilescov, Pedro

    1997-01-01

    In nuclear reactors, the occurrence of critical heat flux leads to fuel rod overheating with clad fusion and radioactive products leakage. To predict the effects of such phenomenon, experiments are performed using electrically heated rods to simulate operational and accidental conditions of nuclear fuel rods. In the present work, a theoretical analysis of the drying and rewetting front propagation is performed during a critical heat flux experiment, starting with the application of slope of electrical power from steady state condition. After the occurrence of critical heat flux, the drying front propagation is predicted. After a few seconds, a power cut is considered and the rewetting front behavior is analytically observed. Studies done with several values of coolant mass flow rate show that this variable has more influence on the drying front velocity than on the rewetting one. (author)

  16. A percolation approach to study the high electric field effect on electrical conductivity of insulating polymer

    Science.gov (United States)

    Benallou, Amina; Hadri, Baghdad; Martinez-Vega, Juan; El Islam Boukortt, Nour

    2018-04-01

    The effect of percolation threshold on the behaviour of electrical conductivity at high electric field of insulating polymers has been briefly investigated in literature. Sometimes the dead ends links are not taken into account in the study of the electric field effect on the electrical properties. In this work, we present a theoretical framework and Monte Carlo simulation of the behaviour of the electric conductivity at high electric field based on the percolation theory using the traps energies levels which are distributed according to distribution law (uniform, Gaussian, and power-law). When a solid insulating material is subjected to a high electric field, and during trapping mechanism the dead ends of traps affect with decreasing the electric conductivity according to the traps energies levels, the correlation length of the clusters, the length of the dead ends, and the concentration of the accessible positions for the electrons. A reasonably good agreement is obtained between simulation results and the theoretical framework.

  17. Assessing the dynamic material criticality of infrastructure transitions: A case of low carbon electricity

    International Nuclear Information System (INIS)

    Roelich, Katy; Dawson, David A.; Purnell, Phil; Knoeri, Christof; Revell, Ruairi; Busch, Jonathan; Steinberger, Julia K.

    2014-01-01

    Highlights: • We present a method to analyse material criticality of infrastructure transitions. • Criticality is defined as the potential for, and exposure to, supply disruption. • Our method is dynamic reducing the probability of lock-in to at-risk technologies. • We show that supply disruption potential is reducing but exposure is increasing. - Abstract: Decarbonisation of existing infrastructure systems requires a dynamic roll-out of technology at an unprecedented scale. The potential disruption in supply of critical materials could endanger such a transition to low-carbon infrastructure and, by extension, compromise energy security more broadly because low carbon technologies are reliant on these materials in a way that fossil-fuelled energy infrastructure is not. Criticality is currently defined as the combination of the potential for supply disruption and the exposure of a system of interest to that disruption. We build on this definition and develop a dynamic approach to quantifying criticality, which monitors the change in criticality during the transition towards a low-carbon infrastructure goal. This allows us to assess the relative risk of different technology pathways to reach a particular goal and reduce the probability of being ‘locked in’ to currently attractive but potentially future-critical technologies. To demonstrate, we apply our method to criticality of the proposed UK electricity system transition, with a focus on neodymium. We anticipate that the supply disruption potential of neodymium will decrease by almost 30% by 2050; however, our results show the criticality of low carbon electricity production increases ninefold over this period, as a result of increasing exposure to neodymium-reliant technologies

  18. High electric field conduction in low-alkali boroaluminosilicate glass

    Science.gov (United States)

    Dash, Priyanka; Yuan, Mengxue; Gao, Jun; Furman, Eugene; Lanagan, Michael T.

    2018-02-01

    Electrical conduction in silica-based glasses under a low electric field is dominated by high mobility ions such as sodium, and there is a transition from ionic transport to electronic transport as the electric field exceeds 108 V/m at low temperatures. Electrical conduction under a high electric field was investigated in thin low-alkali boroaluminosilicate glass samples, showing nonlinear conduction with the current density scaling approximately with E1/2, where E is the electric field. In addition, thermally stimulated depolarization current (TSDC) characterization was carried out on room-temperature electrically poled glass samples, and an anomalous discharging current flowing in the same direction as the charging current was observed. High electric field conduction and TSDC results led to the conclusion that Poole-Frenkel based electronic transport occurs in the mobile-cation-depleted region adjacent to the anode, and accounts for the observed anomalous current.

  19. Advanced simulation for analysis of critical infrastructure : abstract cascades, the electric power grid, and Fedwire.

    Energy Technology Data Exchange (ETDEWEB)

    Glass, Robert John, Jr.; Stamber, Kevin Louis; Beyeler, Walter Eugene

    2004-08-01

    Critical Infrastructures are formed by a large number of components that interact within complex networks. As a rule, infrastructures contain strong feedbacks either explicitly through the action of hardware/software control, or implicitly through the action/reaction of people. Individual infrastructures influence others and grow, adapt, and thus evolve in response to their multifaceted physical, economic, cultural, and political environments. Simply put, critical infrastructures are complex adaptive systems. In the Advanced Modeling and Techniques Investigations (AMTI) subgroup of the National Infrastructure Simulation and Analysis Center (NISAC), we are studying infrastructures as complex adaptive systems. In one of AMTI's efforts, we are focusing on cascading failure as can occur with devastating results within and between infrastructures. Over the past year we have synthesized and extended the large variety of abstract cascade models developed in the field of complexity science and have started to apply them to specific infrastructures that might experience cascading failure. In this report we introduce our comprehensive model, Polynet, which simulates cascading failure over a wide range of network topologies, interaction rules, and adaptive responses as well as multiple interacting and growing networks. We first demonstrate Polynet for the classical Bac, Tang, and Wiesenfeld or BTW sand-pile in several network topologies. We then apply Polynet to two very different critical infrastructures: the high voltage electric power transmission system which relays electricity from generators to groups of distribution-level consumers, and Fedwire which is a Federal Reserve service for sending large-value payments between banks and other large financial institutions. For these two applications, we tailor interaction rules to represent appropriate unit behavior and consider the influence of random transactions within two stylized networks: a regular homogeneous array

  20. Analysis of critical thinking ability in direct current electrical problems solving

    Science.gov (United States)

    Hartono; Sunarno, Widha; Sarwanto; Arya Nugraha, Dewanta

    2017-11-01

    This study concern on analyzing the ability of students in critical thinking skills on the subject matter of direct current electricity. Samples were taken using purposive random sampling consisted of 32 students of grade XI, Multimedia 1, SMK Negeri 3 Surakarta in academic year 2016/2017. This study used descriptive quantitative method. The data were collected using tests and interviews regarding the subject matter of direct current electricity. Based on the results, students are getting some difficulties in solving problem in indicator 4. The average of students’ correct answer is 62.8%.

  1. Critical study of high efficiency deep grinding

    OpenAIRE

    Johnstone, lain

    2002-01-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experim...

  2. Thermalhydraulic behavior of electrically heated rods during critical heat flux transients

    International Nuclear Information System (INIS)

    Lima, Rita de Cassia Fernandes de

    1997-01-01

    In nuclear reactors, the occurrence of critical heat flux leads to fuel rod overheating with clad fusion and radioactive products leakage. To predict the effects of such phenomenon, experiments are performed utilizing heated rods to simulate operational and accidental conditions of nuclear fuel rods, with special attention to the phenomenon of boiling crisis. The use of mechanisms which detect the abrupt temperature rise allows the electric power switch off. These facts prevent the test section from damage. During the critical heat flux phenomenon the axial heat conduction becomes very important. The study of the dryout and rewetting fronts yields the analysis, planning and following of critical heat flux experiments. These facts are important during the reflooding of nuclear cores at severe accidents. In the present work it is performed a theoretical analysis of the drying and rewetting front propagation during a critical heat flux experiment, starting with the application of an electrical power step or power slope from steady state condition. After the occurrence of critical heat flux, it is predicted the drying front propagation. After a few seconds, a power cut is considered and the rewetting front behavior is analytically observed. In all these transients the coolant pressure is 13,5 MPa. For one of them, comparisons are done with a pressure of 8,00 MPa. Mass flow and enthalpy influences on the fronts velocities are also analysed. These results show that mass flow has more importance on the drying front velocities whereas the pressure alters strongly the rewetting ones. (author)

  3. Onsite and Electric Backup Capabilities at Critical Infrastructure Facilities in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Julia A. [Argonne National Lab. (ANL), Argonne, IL (United States); Wallace, Kelly E. [Argonne National Lab. (ANL), Argonne, IL (United States); Kudo, Terence Y. [Argonne National Lab. (ANL), Argonne, IL (United States); Eto, Joseph H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-04-01

    The following analysis, conducted by Argonne National Laboratory’s (Argonne’s) Risk and Infrastructure Science Center (RISC), details an analysis of electric power backup of national critical infrastructure as captured through the Department of Homeland Security’s (DHS’s) Enhanced Critical Infrastructure Program (ECIP) Initiative. Between January 1, 2011, and September 2014, 3,174 ECIP facility surveys have been conducted. This study focused first on backup capabilities by infrastructure type and then expanded to infrastructure type by census region.

  4. Replacing critical rare earth materials in high energy density magnets

    Science.gov (United States)

    McCallum, R. William

    2012-02-01

    High energy density permanent magnets are crucial to the design of internal permanent magnet motors (IPM) for hybride and electric vehicles and direct drive wind generators. Current motor designs use rare earth permanent magnets which easily meet the performance goals, however, the rising concerns over cost and foreign control of the current supply of rare earth resources has motivated a search for non-rare earth based permanent magnets alloys with performance metrics which allow the design of permanent magnet motors and generators without rare earth magnets. This talk will discuss the state of non-rare-earth permanent magnets and efforts to both improve the current materials and find new materials. These efforts combine first principles calculations and meso-scale magnetic modeling with advance characterization and synthesis techniques in order to advance the state of the art in non rare earth permanent magnets. The use of genetic algorithms in first principle structural calculations, combinatorial synthesis in the experimental search for materials, atom probe microscopy to characterize grain boundaries on the atomic level, and other state of the art techniques will be discussed. In addition the possibility of replacing critical rare earth elements with the most abundant rare earth Ce will be discussed.

  5. Study of critical dependence of stable phases in Nitinol on heat treatment using electrical resistivity probe

    International Nuclear Information System (INIS)

    Uchil, J.; Mohanchandra, K.P.; Kumara, K.G.; Mahesh, K.K.

    1998-01-01

    Phase transformations in 40% cold-worked Nitinol as a function of heat treatment have been studied using electrical resistivity variation with temperature. The stabilisation of austenitic, rhombohedral and martensitic phases is shown to critically depend on the temperatures of heat treatment by the analysis of temperature dependence of electrical resistivity in heating and cooling parts of the cycle. Characteristic values of electrical resistivity of the stable phases are determined. The R-phase has been found to form continuously with increasing heat-treatment temperature starting from room temperature and to suddenly disappear beyond heat-treatment at 683 K. The observed presence or absence of R-phase is confirmed by heat capacity measurements as a function of temperature. (orig.)

  6. Criticality safety in high explosives dissolution

    International Nuclear Information System (INIS)

    Troyer, S.D.

    1997-01-01

    In 1992, an incident occurred at the Pantex Plant in which the cladding around a fissile material component (pit) cracked during dismantlement of the high explosives portion of a nuclear weapon. Although the event did not result in any significant contamination or personnel exposures, concerns about the incident led to the conclusion that the current dismantlement process was unacceptable. Options considered for redesign, dissolution tooling design considerations, dissolution tooling design features, and the analysis of the new dissolution tooling are summarized. The final tooling design developed incorporated a number of safety features and provides a simple, self-contained, low-maintenance method of high explosives removal for nuclear explosive dismantlement. Analyses demonstrate that the tooling design will remain subcritical under normal, abnormal, and credible accident scenarios. 1 fig

  7. Static Electricity as Part of Electromagnetic Environment on High-Voltage Electrical Substation

    Directory of Open Access Journals (Sweden)

    M. I. Fursanov

    2012-01-01

    Full Text Available Causes of occurrences electrostatic discharges (ESD on high-voltage electric substation were investigated and dependences values ESD’s on parameters interaction structures, humidity of air were found. Experimental research values ESD’s on high-voltage electric substation and in man-made conditions was fulfilled. Uncertainty measurement’s was taken into consideration by research results analyze. Matching with research of other authors was made. Danger ESD’s for electric devises was established.

  8. Integration of electric drive vehicles in the Danish electricity network with high wind power penetration

    DEFF Research Database (Denmark)

    Chandrashekhara, Divya K; Østergaard, Jacob; Larsen, Esben

    2010-01-01

    /conventional) which are likely to fuel these cars. The study was carried out considering the Danish electricity network state around 2025, when the EDV penetration levels would be significant enough to have an impact on the power system. Some of the interesting findings of this study are - EDV have the potential......This paper presents the results of a study carried out to examine the feasibility of integrating electric drive vehicles (EDV) in the Danish electricity network which is characterised by high wind power penetration. One of the main aims of this study was to examine the effect of electric drive...... vehicles on the Danish electricity network, wind power penetration and electricity market. In particular the study examined the effect of electric drive vehicles on the generation capacity constraints, load curve, cross border transmission capacity and the type of generating sources (renewable...

  9. Critical current of high Tc superconducting Bi223/Ag tapes

    NARCIS (Netherlands)

    Huang, Y.; ten Haken, Bernard; ten Kate, Herman H.J.

    1998-01-01

    The magnetic field dependence of the critical current of various high Tc superconducting Bi2223/Ag tapes indicates that the transport current is carried through two paths: one is through weakly-linked grain boundaries (Josephson junctions); another is through well-connected grains. The critical

  10. Moderate and high intensity pulsed electric fields

    NARCIS (Netherlands)

    Timmermans, Rian Adriana Hendrika

    2018-01-01

    Pulsed Electric Field (PEF) processing has gained a lot of interest the last decades as mild processing technology as alternative to thermal pasteurisation, and is suitable for preservation of liquid food products such as fruit juices. PEF conditions typically applied at industrial scale for

  11. Plasma instabilities in high electric fields

    DEFF Research Database (Denmark)

    Morawetz, K.; Jauho, Antti-Pekka

    1994-01-01

    expression is derived for the nonequilibrium dielectric function epsilon(K, omega). For certain values of momenta K and frequency omega, Imepsilon(K, omega) becomes negative, implying a plasma instability. This new instability exists only for strong electric fields, underlining its nonequilibrium origin....

  12. High School Students' Representations and Understandings of Electric Fields

    Science.gov (United States)

    Cao, Ying; Brizuela, Bárbara M.

    2016-01-01

    This study investigates the representations and understandings of electric fields expressed by Chinese high school students 15 to 16 years old who have not received high school level physics instruction. The physics education research literature has reported students' conceptions of electric fields post-instruction as indicated by students'…

  13. Power Requirements Determined for High-Power-Density Electric Motors for Electric Aircraft Propulsion

    Science.gov (United States)

    Johnson, Dexter; Brown, Gerald V.

    2005-01-01

    Future advanced aircraft fueled by hydrogen are being developed to use electric drive systems instead of gas turbine engines for propulsion. Current conventional electric motor power densities cannot match those of today s gas turbine aircraft engines. However, if significant technological advances could be made in high-power-density motor development, the benefits of an electric propulsion system, such as the reduction of harmful emissions, could be realized.

  14. Patterns in Soil Electrical Resistivity Across Land Uses in the Calhoun Critical Zone Observatory Landscape

    Science.gov (United States)

    Markewitz, D.; Sutter, L.; Richter, D. D., Jr.

    2017-12-01

    Soil Electrical Resistivity Tomography (ERT) was measured across the Calhoun Critical Zone Observatory in relation to land use cover. ERT can help identify patterns in soil and saprolite physical attributes and moisture content through multiple meters. ERT data were generated with an AGI Supersting R8 with a 28 probe dipole-dipole array on a 1.5 meter spacing providing information through the upper 9 m. In Nov/Dec 2016 ten soil pits were dug to 3m depth in agricultural fields, pine forests, and hardwood forests across the CCZO and ERT measures were taken centered on these pits. ERT values ranged from 200 to 2500 Ohm-m. ERT patterns in the agricultural field demonstrated a limited resistivity gradient (200-700 Ohm-m) appearing moist throughout. In contrast, research areas under pine and hardwood forest had stronger resistivity gradients reflecting both moisture and physical attributes (i.e., texture or rock content). For example, research area 2 under pine had an area of higher resistivity that correlated with a band of saprolite that was readily visible in the exposed profile. In research area 7 and 8 that included both pine and hardwood forest resistivity gradients had contradictory patterns of high to low resistivity from top to bottom. In research area 7 resistivity was highest at the surface and decreased with depth, a common pattern when water table is at depth. In research area 8 the inverse was observed with low resistivity above and resistivity increasing with depth, a pattern observed in upper landscape positions on ridges with moist clay above dry saprolite. ERT patterns did reflect a large difference in the measured agricultural fields compared to forest while other difference appeared to reflect landscape position.

  15. A survey of critical research areas in the energy segment of restructured electric power markets

    International Nuclear Information System (INIS)

    Nanduri, Vishnu; Das, Tapas K.

    2009-01-01

    Availability of a large volume of recent literature on deregulated (a.k.a. restructured) electricity markets underscores the importance of the research needs to ensure proper design and functioning of the markets. Researchers have made significant contributions fueling the evolution of the fundamental market design changes that have taken place since the beginning of the restructuring process. Due to the vast scope, existing survey papers are focused on particular facets of deregulated electricity markets. We adopt a similar approach by focusing on the most important research areas related to the energy market. The contributions of the survey paper lie in the novel approach used in classifying the literature based on critical research areas. Some areas of research such as auction based pricing, bidding strategy formulation, market equilibria, and market power are reviewed in a different light than other existing survey papers. We conclude by providing some future research directions for the energy markets. (author)

  16. Renewable Electricity Futures Study. Volume 1. Exploration of High-Penetration Renewable Electricity Futures

    Energy Technology Data Exchange (ETDEWEB)

    Hand, M. M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Baldwin, S. [U.S. Dept. of Energy, Washington, DC (United States); DeMeo, E. [Renewable Energy Consulting, Chicago, IL (United States); Reilly, J. M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Mai, T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, D. [Joint Inst. for Strategic Energy Analysis, Boulder, CO (United States); Porro, G. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Meshek, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sandor, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2012-06-15

    The Renewable Electricity Futures (RE Futures) Study investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. The analysis focused on the sufficiency of the geographically diverse U.S. renewable resources to meet electricity demand over future decades, the hourly operational characteristics of the U.S. grid with high levels of variable wind and solar generation, and the potential implications of deploying high levels of renewables in the future. RE Futures focused on technical aspects of high penetration of renewable electricity; it did not focus on how to achieve such a future through policy or other measures. Given the inherent uncertainties involved with analyzing alternative long-term energy futures as well as the multiple pathways that might be taken to achieve higher levels of renewable electricity supply, RE Futures explored a range of scenarios to investigate and compare the impacts of renewable electricity penetration levels (30%–90%), future technology performance improvements, potential constraints to renewable electricity development, and future electricity demand growth assumptions. RE Futures was led by the National Renewable Energy Laboratory (NREL) and the Massachusetts Institute of Technology (MIT). Learn more at the RE Futures website. http://www.nrel.gov/analysis/re_futures/

  17. Renewable Electricity Futures Study. Volume 1: Exploration of High-Penetration Renewable Electricity Futures

    Energy Technology Data Exchange (ETDEWEB)

    Mai, T.; Wiser, R.; Sandor, D.; Brinkman, G.; Heath, G.; Denholm, P.; Hostick, D.J.; Darghouth, N.; Schlosser, A.; Strzepek, K.

    2012-06-01

    The Renewable Electricity Futures (RE Futures) Study investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. The analysis focused on the sufficiency of the geographically diverse U.S. renewable resources to meet electricity demand over future decades, the hourly operational characteristics of the U.S. grid with high levels of variable wind and solar generation, and the potential implications of deploying high levels of renewables in the future. RE Futures focused on technical aspects of high penetration of renewable electricity; it did not focus on how to achieve such a future through policy or other measures. Given the inherent uncertainties involved with analyzing alternative long-term energy futures as well as the multiple pathways that might be taken to achieve higher levels of renewable electricity supply, RE Futures explored a range of scenarios to investigate and compare the impacts of renewable electricity penetration levels (30%-90%), future technology performance improvements, potential constraints to renewable electricity development, and future electricity demand growth assumptions. RE Futures was led by the National Renewable Energy Laboratory (NREL) and the Massachusetts Institute of Technology (MIT).

  18. Electrical Insulation of 500-m High-Tc Superconducting Power Cable

    International Nuclear Information System (INIS)

    Takahashi, T; Ichikawa, M; Suzuki, H; Okamoto, T; Akita, S; Mukoyama, S; Yagi, M; Maruyama, S; Kimura, A

    2006-01-01

    Electrical insulation is one of the essential technologies for the electric power apparatus. Determination of testing voltages and design method of the electrical insulation layer are inextricably linked each other, and are critical to developing and realizing a cold dielectric (CD) type high-Tc superconducting (HTS) power cable. The authors had proposed the electrical insulation design method with concepts of partial discharge-free designs for ac voltage condition. This paper discusses the testing voltages for a 77 kV 1000 A HTS power cable with a length of 500 m, and describes results of various voltage withstand test. As a result, it is concluded that the proposed electrical insulation design method is appropriate for the HTS power cable

  19. Transport measurements in superconductors: critical current of granular high TC ceramic superconductor samples

    International Nuclear Information System (INIS)

    Passos, W.A.C.

    2016-01-01

    This work presents a method to obtain critical current of granular superconductors. We have carried out transport measurements (ρxT curves and VxI curves) in a YBa_2Cu_3O_7_-_δ sample to determine critical current density of it. Some specimens reveal a 'semiconductor-like' behavior (electrical resistivity decreases with increasing temperatures above critical temperature T_c of material) competing with superconductor behavior. Due to high granular fraction of the sample, these competition is clearly noted in ρxT curves. Measurements carried out from 0 to 8500 Oe of applied field show the same behavior, and the critical current density of the samples is shown. (author)

  20. Criticality of mixtures of plutonium and high enriched uranium

    International Nuclear Information System (INIS)

    Grolleau, E.; Lein, M.; Leka, G.; Maidou, B.; Klenov, P.

    2003-01-01

    This paper presents a criticality evaluation of moderated homogeneous plutonium-uranium mixtures. The fissile media studied are homogeneous mixtures of plutonium and high enriched uranium in two chemical forms: aqueous mixtures of metal and mixtures of nitrate solutions. The enrichment of uranium considered are 93.2wt.% 235 U and 100wt.% 235 U. The 240 Pu content in plutonium varies from 0wt.% 240 Pu to 12wt.% 240 Pu. The critical parameters (radii and masses of a 20 cm water reflected sphere) are calculated with the French criticality safety package CRISTAL V0. The comparison of the calculated critical parameters as a function of the moderator-to-fuel atomic ratio shows significant ranges in which high enriched uranium systems, as well as plutonium-uranium mixtures, are more reactive than plutonium systems. (author)

  1. The exponential critical state of high-Tc ceramics

    International Nuclear Information System (INIS)

    Castro, H.; Rinderer, L.

    1994-01-01

    The critical current in high-Tc materials is strongly reduced by a magnetic field. We studied this dependency for tubular YBCO samples. We find an exponential drop as the field is increased from zero up to some tens of oersted. This behavior was already observed by others, however little work has been done in this direction. We define what we call the ''exponential critical state'' of HTSC and compare the prediction for the magnetization with experimental data. Furthermore, the ''Kim critical state'' is obtained as the small field limit. (orig.)

  2. Electrical system architecture having high voltage bus

    Science.gov (United States)

    Hoff, Brian Douglas [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL

    2011-03-22

    An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

  3. Global electricity transformation: The critical need for integrated market design and risk management research

    International Nuclear Information System (INIS)

    Hung-po Chao

    2006-01-01

    The past three decades transformed the electricity industry. The essential goals of liberalization have been to lower costs, improve reliability, and stimulate investment and innovations through establishment of competitive electricity markets, while also relying on market mechanisms to provide creative solutions to environmental and security problems. In many instances, these goals have been achieved, but the occurrence of some spectacular market failures have brought into question the whole restructuring effort. This paper reviews recent experiences with market reform and concludes that a significant cause of failure has been the rush to unbundle vertically integrated utilities without sufficient consideration of alternative ways to manage the risk of electricity market restructuring. In particular, there is a critical need for integrated market design and risk management research to improve the process of market transformation by taking a more evolutionary approach to discover a 'Third Way' above vertical integration and full unbundling. Such research can offer a crucial feedback link to the restructuring process by identifying important lessons to be learned from past experience and developing new analytical tools to help introduce more successful market designs for the future. (author)

  4. Critical current and electric transport properties of superconducting epitaxial Nb(Ti)N submicron structures

    Science.gov (United States)

    Klimov, A.; Słysz, W.; Guziewicz, M.; Kolkovsky, V.; Wegrzecki, M.; Bar, J.; Marchewka, M.; Seredyński, B.

    2016-12-01

    Critical current and current-voltage characteristics of epitaxial Nb(Ti)N submicron ultrathin structures were measured as function of temperature. For 700-nm-wide bridge we found current-driven vortex de-pinning at low temperatures and thermally activated flux flow closer to the transition temperature, as the limiting factors for the critical current density. For 100-nm-wide meander we observed combination of phase-slip activation and vortex-anti-vortex pair (VAP) thermal excitation. Our Nb(Ti)N meander structure demonstrates high de-pairing critical current densities 107 A/cm2 at low temperatures, but the critical currents are much smaller due to presence of the local constrictions.

  5. Energy efficiency indicators for high electric-load buildings

    Energy Technology Data Exchange (ETDEWEB)

    Aebischer, Bernard; Balmer, Markus A.; Kinney, Satkartar; Le Strat, Pascale; Shibata, Yoshiaki; Varone, Frederic

    2003-06-01

    Energy per unit of floor area is not an adequate indicator for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed.

  6. Copper wire theft and high voltage electrical burns.

    Science.gov (United States)

    Francis, Eamon C; Shelley, Odhran P

    2014-01-01

    High voltage electrical burns are uncommon. However in the midst of our economic recession we are noticing an increasing number of these injuries. Copper wire is a valuable commodity with physical properties as an excellent conductor of electricity making it both ubiquitous in society and prized on the black market. We present two consecutive cases referred to the National Burns Unit who sustained life threatening injuries from the alleged theft of high voltage copper wire and its omnipresence on an international scale.

  7. Copper wire theft and high voltage electrical burns

    OpenAIRE

    Francis, Eamon C; Shelley, Odhran P

    2014-01-01

    High voltage electrical burns are uncommon. However in the midst of our economic recession we are noticing an increasing number of these injuries. Copper wire is a valuable commodity with physical properties as an excellent conductor of electricity making it both ubiquitous in society and prized on the black market. We present two consecutive cases referred to the National Burns Unit who sustained life threatening injuries from the alleged theft of high voltage copper wire and its omnipresenc...

  8. Critical review of on-board capacity estimation techniques for lithium-ion batteries in electric and hybrid electric vehicles

    Science.gov (United States)

    Farmann, Alexander; Waag, Wladislaw; Marongiu, Andrea; Sauer, Dirk Uwe

    2015-05-01

    This work provides an overview of available methods and algorithms for on-board capacity estimation of lithium-ion batteries. An accurate state estimation for battery management systems in electric vehicles and hybrid electric vehicles is becoming more essential due to the increasing attention paid to safety and lifetime issues. Different approaches for the estimation of State-of-Charge, State-of-Health and State-of-Function are discussed and analyzed by many authors and researchers in the past. On-board estimation of capacity in large lithium-ion battery packs is definitely one of the most crucial challenges of battery monitoring in the aforementioned vehicles. This is mostly due to high dynamic operation and conditions far from those used in laboratory environments as well as the large variation in aging behavior of each cell in the battery pack. Accurate capacity estimation allows an accurate driving range prediction and accurate calculation of a battery's maximum energy storage capability in a vehicle. At the same time it acts as an indicator for battery State-of-Health and Remaining Useful Lifetime estimation.

  9. Critical Science Education in a Suburban High School Chemistry Class

    Science.gov (United States)

    Ashby, Patrick

    To improve students' scientific literacy and their general perceptions of chemistry, I enacted critical chemistry education (CCE) in two "regular level" chemistry classes with a group of 25 students in a suburban, private high school as part of this study. CCE combined the efforts of critical science educators (Fusco & Calabrese Barton, 2001; Gilbert 2013) with the performance expectations of the Next Generation Science Standards (NGSS) (NGSS Lead States, 2013a) to critically transform the traditional chemistry curriculum at this setting. Essentially, CCE engages students in the critical exploration of socially situated chemistry content knowledge and requires them to demonstrate this knowledge through the practices of science. The purpose of this study was to gauge these students development of chemistry content knowledge, chemistry interest, and critical scientific literacy (CSL) as they engaged in CCE. CSL was a construct developed for this study that necessarily combined the National Research Center's (2012) definition of scientific literacy with a critical component. As such, CSL entailed demonstrating content knowledge through the practices of science as well as the ability to critically analyze the intersections between science content and socially relevant issues. A mixed methods, critical ethnographic approach framed the collection of data from open-ended questionnaires, focus group interviews, Likert surveys, pre- and post unit tests, and student artifacts. These data revealed three main findings: (1) students began to develop CSL in specific, significant ways working through the activities of CCE, (2) student participants of CCE developed a comparable level of chemistry content understanding to students who participated in a traditional chemistry curriculum, and (3) CCE developed a group of students' perceptions of interest in chemistry. In addition to being able to teach students discipline specific content knowledge, the implications of this study are

  10. Method and apparatus for preventing inadvertent criticality in a nuclear fueled electric power generating unit

    International Nuclear Information System (INIS)

    Tuley, C.R.; Bauman, D.A.; Neuner, J.A.; Feilchenfeld, M.M.; Greenberg, L.

    1984-01-01

    An inadvertent approach to criticality in a nuclear fueled electric power generating unit is detected and an alarm is generated through on-line monitoring of the neutron flux. The difficulties of accurately measuring the low levels of neutron flux in a subcritical reactor are overcome by the use of a microcomputer which continuously generates average flux count rate signals for incremental time periods from thousands of samples taken during each such period and which serially stores the average flux count rate signals for a preselected time interval. At the end of each incremental time period, the microcomputer compares the latest average flux count rate signal with the oldest, and preferably each of the intervening stored values, and if it exceeds any of them by at least a preselected multiplication factor, an alarm is generated. (author)

  11. Growth and decay of runaway electrons above the critical electric field under quiescent conditions

    International Nuclear Information System (INIS)

    Paz-Soldan, C.; Eidietis, N. W.; Wesley, J. C.; Granetz, R.; Hollmann, E. M.; Moyer, R. A.; Zhang, J.; Crocker, N. A.; Austin, M. E.; Wingen, A.; Zhu, Y.

    2014-01-01

    Extremely low density operation free of error field penetration supports the excitation of trace-level quiescent runaway electron (RE) populations during the flat-top of DIII-D Ohmic discharges. Operation in the quiescent regime allows accurate measurement of all key parameters important to RE excitation, including the internal broadband magnetic fluctuation level. RE onset is characterized and found to be consistent with primary (Dreicer) generation rates. Impurity-free collisional suppression of the RE population is investigated by stepping the late-time main-ion density, until RE decay is observed. The transition from growth to decay is found to occur 3–5 times above the theoretical critical electric field for avalanche growth and is thus indicative of anomalous RE loss. This suggests that suppression of tokamak RE avalanches can be achieved at lower density than previously expected, though extrapolation requires predictive understanding of the RE loss mechanism and magnitude

  12. Potential criticality accident at the General Electric Nuclear Fuel and Component Manufacturing Facility, May 29, 1991

    International Nuclear Information System (INIS)

    1991-08-01

    At the General Electric Nuclear Fuel and Component Manufacturing facility, located near Wilmington, North Carolina, on May 28 and 29, 1991, approximately 150 kilograms of uranium were inadvertently transferred from safe process tanks to an unsafe tank located at the waste treatment facility, thus creating the potential for a localized criticality safety problem. The excess uranium was ultimately safely recovered when the tank contents were centrifuged to remove the uranium-bearing material. Subsequently, the US Nuclear Regulatory Commission dispatched an Incident Investigation Team to determine what happened, to identify probable causes, and to make appropriate findings and conclusions. This report describes the incident, the methodology used by the team in its investigation, and presents the team's findings and conclusions. 48 figs., 8 tabs

  13. Analysis and evaluation of ZPPR critical experiments for a 100 kilowatt-electric space reactor

    International Nuclear Information System (INIS)

    McFarlane, H.F.; Collins, P.J.; Carpenter, S.G.; Olsen, D.N.; Smith, D.M.; Schaefer, R.W.; Doncals, R.A.; Andre, S.V.; Porter, C.A.; Cowan, C.L.; Stewart, S.L.; Protsik, R.

    1990-01-01

    ZPPR critical experiments were used for physics testing the reactor design of the SP-100, a 100-kW thermoelectric LMR that is being developed to provide electrical power for space applications. These tests validated all key physics characteristics of the design, including the ultimate safety in the event of a launch or re-entry accident. Both the experiments and the analysis required the use of techniques not previously needed for fast reactor designs. A few significant discrepancies between the experimental and calculated results leave opportunities for further reductions in the mass of the SP-100. An initial investigation has been made into application of the ZPPR-20 results, along with those of other relevant integral data, to the SP-100 design

  14. Nonlinear piezoelectricity in epitaxial ferroelectrics at high electric fields.

    Science.gov (United States)

    Grigoriev, Alexei; Sichel, Rebecca; Lee, Ho Nyung; Landahl, Eric C; Adams, Bernhard; Dufresne, Eric M; Evans, Paul G

    2008-01-18

    Nonlinear effects in the coupling of polarization with elastic strain have been predicted to occur in ferroelectric materials subjected to high electric fields. Such predictions are tested here for a PbZr0.2Ti0.8O3 ferroelectric thin film at electric fields in the range of several hundred MV/m and strains reaching up to 2.7%. The piezoelectric strain exceeds predictions based on constant piezoelectric coefficients at electric fields from approximately 200 to 400 MV/m, which is consistent with a nonlinear effect predicted to occur at corresponding piezoelectric distortions.

  15. High Penetrated Wind Farm Impacts on the Electricity Price

    DEFF Research Database (Denmark)

    Haji Bashi, Mazaher; Yousefi, G. R.; Bak, Claus Leth

    2016-01-01

    of the high penetrated wind farm integration into electricity markets. Then, stochastic programming approach is employed to compare the volume of trades for a typical wind farm in a high and low wind penetrated market. Although increasing price spikes and volatility was reported in the literature......Energy trading policies, intermittency of wind farm output power, low marginal cost of the production, are the key factors that cause the wind farms to be effective on the electricity price. In this paper, the Danish electricity market is studied as a part of Nord Pool. Considering the completely...... fossil fuel free overview in Danish energy policies, and the currently great share of wind power (more than 100% for some hours) in supplying the load, it is an interesting benchmark for the future electricity markets. Negative prices, price spikes, and price volatility are considered as the main effects...

  16. Fabrication of highly conductive carbon nanotube fibers for electrical application

    International Nuclear Information System (INIS)

    Guo, Fengmei; Li, Can; Wei, Jinquan; Xu, Ruiqiao; Zhang, Zelin; Cui, Xian; Wang, Kunlin; Wu, Dehai

    2015-01-01

    Carbon nanotubes (CNTs) have great potential for use as electrical wires because of their outstanding electrical and mechanical properties. Here, we fabricate lightweight CNT fibers with electrical conductivity as high as that of stainless steel from macroscopic CNT films by drawing them through diamond wire-drawing dies. The entangled CNT bundles are straightened by suffering tension, which improves the alignment of the fibers. The loose fibers are squeezed by the diamond wire-drawing dies, which reduces the intertube space and contact resistance. The CNT fibers prepared by drawing have an electrical conductivity as high as 1.6 × 10 6 s m −1 . The fibers are very stable when kept in the air and under cyclic tensile test. A prototype of CNT motor is demonstrated by replacing the copper wires with the CNT fibers. (paper)

  17. Microstructures and critical currents in high-Tc superconductors

    International Nuclear Information System (INIS)

    Suenaga, Masaki

    1998-01-01

    Microstructural defects are the primary determining factors for the values of critical-current densities in a high T c superconductor after the electronic anisotropy along the a-b plane and the c-direction. A review is made to assess firstly what would be the maximum achievable critical-current density in YBa 2 Cu 3 O 7 if nearly ideal pinning sites were introduced and secondly what types of pinning defects are currently introduced or exist in YBa 2 Cu 3 O 7 and how effective are these in pinning vortices

  18. Neuromuscular Electrical Stimulation for Treatment of Muscle Impairment: Critical Review and Recommendations for Clinical Practice

    Science.gov (United States)

    Houghton, Pamela; Anthony, Joseph; Rennie, Sandy; Shay, Barbara L.; Hoens, Alison M.

    2017-01-01

    Purpose: In response to requests from physiotherapists for guidance on optimal stimulation of muscle using neuromuscular electrical stimulation (NMES), a review, synthesis, and extraction of key data from the literature was undertaken by six Canadian physical therapy (PT) educators, clinicians, and researchers in the field of electrophysical agents. The objective was to identify commonly treated conditions for which there was a substantial body of literature from which to draw conclusions regarding the effectiveness of NMES. Included studies had to apply NMES with visible and tetanic muscle contractions. Method: Four electronic databases (CINAHL, Embase, PUBMED, and SCOPUS) were searched for relevant literature published between database inceptions until May 2015. Additional articles were identified from bibliographies of the systematic reviews and from personal collections. Results: The extracted data were synthesized using a consensus process among the authors to provide recommendations for optimal stimulation parameters and application techniques to address muscle impairments associated with the following conditions: stroke (upper or lower extremity; both acute and chronic), anterior cruciate ligament reconstruction, patellofemoral pain syndrome, knee osteoarthritis, and total knee arthroplasty as well as critical illness and advanced disease states. Summaries of key details from each study incorporated into the review were also developed. The final sections of the article outline the recommended terminology for describing practice using electrical currents and provide tips for safe and effective clinical practice using NMES. Conclusion: This article provides physiotherapists with a resource to enable evidence-informed, effective use of NMES for PT practice. PMID:29162949

  19. D. C. electric field behavior of high lying states in atomic uranium

    International Nuclear Information System (INIS)

    Paisner, J.A.; Carlson, L.R.; Worden, E.F.; Johnson, S.A.; May, C.A.; Solarz, R.W.

    1976-01-01

    The effects of D. C. electric fields on high lying Rydberg and valence states in atomic uranium have been studied. Results of measurements of Stark shifts, lifetime lengthening via l-mixing, critical fields for ionization, barrier tunneling, and the appearance of zero-field parity forbidden transitions are presented for atomic uranium along with the observation of field induced autoionization of valence states. 3 figs

  20. Experiments and Computational Theory for Electrical Breakdown in Critical Components: THz Imaging of Electronic Plasmas.

    Energy Technology Data Exchange (ETDEWEB)

    Zutavern, Fred J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hjalmarson, Harold P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bigman, Verle Howard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gallegos, Richard Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    This report describes the development of ultra-short pulse laser (USPL) induced terahertz (THz) radiation to image electronic plasmas during electrical breakdown. The technique uses three pulses from two USPLs to (1) trigger the breakdown, (2) create a 2 picosecond (ps, 10 -12 s), THz pulse to illuminate the breakdown, and (3) record the THz image of the breakdown. During this three year internal research program, sub-picosecond jitter timing for the lasers, THz generation, high bandwidth (BW) diagnostics, and THz image acquisition was demonstrated. High intensity THz radiation was optically-induced in a pulse-charged gallium arsenide photoconductive switch. The radiation was collected, transported, concentrated, and co-propagated through an electro-optic crystal with an 800 nm USPL pulse whose polarization was rotated due to the spatially varying electric field of the THz image. The polarization modulated USPL pulse was then passed through a polarizer and the resulting spatially varying intensity was detected in a high resolution digital camera. Single shot images had a signal to noise of %7E3:1. Signal to noise was improved to %7E30:1 with several experimental techniques and by averaging the THz images from %7E4000 laser pulses internally and externally with the camera and the acquisition system (40 pulses per readout). THz shadows of metallic films and objects were also recorded with this system to demonstrate free-carrier absorption of the THz radiation and improve image contrast and resolution. These 2 ps THz pulses were created and resolved with 100 femtosecond (fs, 10 -15 s) long USPL pulses. Thus this technology has the capability to time-resolve extremely fast repetitive or single shot phenomena, such as those that occur during the initiation of electrical breakdown. The goal of imaging electrical breakdown was not reached during this three year project. However, plans to achieve this goal as part of a follow-on project are described in this document

  1. High current density, cryogenically cooled sliding electrical joint development

    International Nuclear Information System (INIS)

    Murray, H.

    1986-09-01

    In the past two years, conceptual designs for fusion energy research devices have focussed on compact, high magnetic field configurations. The concept of sliding electrical joints in the large magnets allows a number of technical advantages including enhanced mechanical integrity, remote maintainability, and reduced project cost. The rationale for sliding electrical joints is presented. The conceptual configuration for this generation of experimental devices is highlghted by an ∼ 20 T toroidal field magnet with a flat top conductor current of ∼ 300 kA and a sliding electrical joint with a gross current density of ∼ 0.6 kA/cm 2 . A numerical model was used to map the conductor current distribution as a function of time and position in the conductor. A series of electrical joint arrangements were produced against the system code envelope constraints for a specific version of the Ignition Studies Project (ISP) which is designated as 1025

  2. A nonconjugated radical polymer glass with high electrical conductivity

    Science.gov (United States)

    Joo, Yongho; Agarkar, Varad; Sung, Seung Hyun; Savoie, Brett M.; Boudouris, Bryan W.

    2018-03-01

    Solid-state conducting polymers usually have highly conjugated macromolecular backbones and require intentional doping in order to achieve high electrical conductivities. Conversely, single-component, charge-neutral macromolecules could be synthetically simpler and have improved processibility and ambient stability. We show that poly(4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl), a nonconjugated radical polymer with a subambient glass transition temperature, underwent rapid solid-state charge transfer reactions and had an electrical conductivity of up to 28 siemens per meter over channel lengths up to 0.6 micrometers. The charge transport through the radical polymer film was enabled with thermal annealing at 80°C, which allowed for the formation of a percolating network of open-shell sites in electronic communication with one another. The electrical conductivity was not enhanced by intentional doping, and thin films of this material showed high optical transparency.

  3. Turkey's High Temperature Geothermal Energy Resources and Electricity Production Potential

    Science.gov (United States)

    Bilgin, Ö.

    2012-04-01

    Turkey is in the first 7 countries in the world in terms of potential and applications. Geothermal energy which is an alternative energy resource has advantages such as low-cost, clean, safe and natural resource. Geothermal energy is defined as hot water and steam which is formed by heat that accumulated in various depths of the Earth's crust; with more than 20oC temperature and which contain more than fused minerals, various salts and gases than normal underground and ground water. It is divided into three groups as low, medium and high temperature. High-temperature fluid is used in electricity generation, low and medium temperature fluids are used in greenhouses, houses, airport runways, animal farms and places such as swimming pools heating. In this study high temperature geothermal fields in Turkey which is suitable for electricity production, properties and electricity production potential was investigated.

  4. A Novel Series Connected Batteries State of High Voltage Safety Monitor System for Electric Vehicle Application

    Directory of Open Access Journals (Sweden)

    Qiang Jiaxi

    2013-01-01

    Full Text Available Batteries, as the main or assistant power source of EV (Electric Vehicle, are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS, the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application.

  5. A novel series connected batteries state of high voltage safety monitor system for electric vehicle application.

    Science.gov (United States)

    Jiaxi, Qiang; Lin, Yang; Jianhui, He; Qisheng, Zhou

    2013-01-01

    Batteries, as the main or assistant power source of EV (Electric Vehicle), are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS), the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application.

  6. Processing and critical currents of high-Tc superconductor wires

    International Nuclear Information System (INIS)

    Krauth, H.; Heine, K.; Tenbrink, J.

    1991-01-01

    High-Tc superconductors are expected to have a major impact on magnet and energy technology. For technical applications they have to fulfill the requirement of carrying sufficient current at a critical current density of the order of 10 5 A/cm 2 at operating temperature and magnetic field. At 77 K these values have not been achieved yet in bulk material or wires due to weak link problems and flux creep effects. Progress made so far and remaining problems will be discussed in detail concentrating on problems concerning development of technical wires. In Bi-based materials technically interesting critical current densities could be achieved at 4.2 K in fields above 20 T (1,2), rendering possible the use of such material for very high field application. (orig.)

  7. Improvement of diagnostic techniques and electrical circuit in azo dye degradation by high voltage electrical discharge

    International Nuclear Information System (INIS)

    Shen Yongjun; Lei Lecheng; Zhang Xingwang; Zhou Minghua; Zhang Yi

    2008-01-01

    Fast electrical diagnostics and improvement of electrical circuits for methyl orange (MO) degradation by high voltage pulsed electrical discharge were investigated. To eliminate electromagnetic radiation, several effective methods were employed. RG 218 coaxial cable was substituted for the common transmission lines to transmit high voltage pulses, and multi-lines in parallel were earthed to avoid electromagnetic interference and, additionally, to reduce the stray inductance of the electrical circuit and increase the pulse rise rate to reduce the energy losses in the transmission system. The problem of the differences in the bandwidths of voltage and current probes causing an error in the calculation of energy dissipation was avoided by reducing the bandwidths of voltage and current measurements to the same value. The real discharge current was obtained by subtracting the capacitive current from the total current. The energy per pulse obtained in the reactor before and after improvement of the diagnostics and electrical circuit were 15.5 mJ and 26.8 mJ, respectively, and the energy efficiencies of MO degradation were 1.34 x 10 -9 mol/J and 1.95 x 10 -9 mol/J, respectively

  8. CRITICAL ISSUES IN HIGH END COMPUTING - FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Corones, James [Krell Institute

    2013-09-23

    High-End computing (HEC) has been a driver for advances in science and engineering for the past four decades. Increasingly HEC has become a significant element in the national security, economic vitality, and competitiveness of the United States. Advances in HEC provide results that cut across traditional disciplinary and organizational boundaries. This program provides opportunities to share information about HEC systems and computational techniques across multiple disciplines and organizations through conferences and exhibitions of HEC advances held in Washington DC so that mission agency staff, scientists, and industry can come together with White House, Congressional and Legislative staff in an environment conducive to the sharing of technical information, accomplishments, goals, and plans. A common thread across this series of conferences is the understanding of computational science and applied mathematics techniques across a diverse set of application areas of interest to the Nation. The specific objectives of this program are: Program Objective 1. To provide opportunities to share information about advances in high-end computing systems and computational techniques between mission critical agencies, agency laboratories, academics, and industry. Program Objective 2. To gather pertinent data, address specific topics of wide interest to mission critical agencies. Program Objective 3. To promote a continuing discussion of critical issues in high-end computing. Program Objective 4.To provide a venue where a multidisciplinary scientific audience can discuss the difficulties applying computational science techniques to specific problems and can specify future research that, if successful, will eliminate these problems.

  9. High-electric-field quantum transport theory for semiconductor superlattices

    International Nuclear Information System (INIS)

    Nguyen Hong Shon; Nazareno, H.N.

    1995-12-01

    Based on the Baym-Kadanoff-Keldysh nonequilibrium Green's functions technique, a quantum transport theory for semiconductor superlattices under high-electric field is developed. This theory is capable of considering collisional broadening, intra-collisional field effects and band transport and hopping regimes simultaneously. Numerical calculations for narrow-miniband superlattices in high electric field, when the hopping regime dominates are in reasonable agreement with experimental results and show a significant deviation from the Boltzmann theory. A semiphenomenological formula for current density in hopping regime is proposed. (author). 60 refs, 4 figs

  10. Copper wire theft and high voltage electrical burns

    Science.gov (United States)

    Francis, Eamon C; Shelley, Odhran P

    2014-01-01

    High voltage electrical burns are uncommon. However in the midst of our economic recession we are noticing an increasing number of these injuries. Copper wire is a valuable commodity with physical properties as an excellent conductor of electricity making it both ubiquitous in society and prized on the black market. We present two consecutive cases referred to the National Burns Unit who sustained life threatening injuries from the alleged theft of high voltage copper wire and its omnipresence on an international scale. PMID:25356371

  11. Wind power bidding in electricity markets with high wind penetration

    International Nuclear Information System (INIS)

    Vilim, Michael; Botterud, Audun

    2014-01-01

    Highlights: • We analyze the pricing systems and wind power trading in electricity markets. • We propose a model that captures the relation between market prices and wind power. • A probabilistic bidding model can increase profits for wind power producers. • Profit maximizing bidding strategies carry risks for power system operators. • We conclude that modifications of current market designs may be needed. - Abstract: Objective: The optimal day-ahead bidding strategy is studied for a wind power producer operating in an electricity market with high wind penetration. Methods: A generalized electricity market is studied with minimal assumptions about the structure of the production, bidding, or consumption of electricity. Two electricity imbalance pricing schemes are investigated, the one price and the two price scheme. A stochastic market model is created to capture the price effects of wind power production and consumption. A bidding algorithm called SCOPES (Supply Curve One Price Estimation Strategy) is developed for the one price system. A bidding algorithm called MIMICS (Multivariate Interdependence Minimizing Imbalance Cost Strategy) is developed for the two price system. Results: Both bidding strategies are shown to have advantages over the assumed “default” bidding strategy, the point forecast. Conclusion: The success of these strategies even in the case of high deviation penalties in a one price system and the implicit deviation penalties of the two price system has substantial implications for power producers and system operators in electricity markets with a high level of wind penetration. Practice implications: From an electricity market design perspective, the results indicate that further penalties or regulations may be needed to reduce system imbalance

  12. Calibration-free electrical conductivity measurements for highly conductive slags

    International Nuclear Information System (INIS)

    Macdonald, Christopher J.; Gao, Huang; Pal, Uday B.; Van den Avyle, James A.; Melgaard, David K.

    2000-01-01

    This research involves the measurement of the electrical conductivity (K) for the ESR (electroslag remelting) slag (60 wt.% CaF 2 - 20 wt.% CaO - 20 wt.% Al 2 O 3 ) used in the decontamination of radioactive stainless steel. The electrical conductivity is measured with an improved high-accuracy-height-differential technique that requires no calibration. This method consists of making continuous AC impedance measurements over several successive depth increments of the coaxial cylindrical electrodes in the ESR slag. The electrical conductivity is then calculated from the slope of the plot of inverse impedance versus the depth of the electrodes in the slag. The improvements on the existing technique include an increased electrochemical cell geometry and the capability of measuring high precision depth increments and the associated impedances. These improvements allow this technique to be used for measuring the electrical conductivity of highly conductive slags such as the ESR slag. The volatilization rate and the volatile species of the ESR slag measured through thermogravimetric (TG) and mass spectroscopy analysis, respectively, reveal that the ESR slag composition essentially remains the same throughout the electrical conductivity experiments

  13. High-power FEL design issues - a critical review

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko, V.N.; Madey, J.M.J.; O`Shea, P.G. [Duke Univ., Durham, NC (United States)

    1995-12-31

    The high-average power capability of FELs has been much advertised but little realized. In this paper we provide a critical analysis of the technological and economic issues associated with high-average power FEL operation from the UV to near IR. The project of IR FEL for the Siberian Center of photochemical researches is described. The distinguished features of this project are the use of the race-track microtron-recuperator and the {open_quotes}electron output of radiation{close_quotes}. The building for the machine is under reconstruction now. About half of hardware has been manufactured. The assembly of installation began.

  14. Bi-based superconducting fibers with high critical parameters

    International Nuclear Information System (INIS)

    Huo Yujing; He Yusheng; Liu Menglin; Mao Sining; Cai Liying; Wang Ying; Zhang Jincang; He Aisheng; Wang Jinsong

    1991-01-01

    Superconducting fibers of Bi(Pb)-Sr-Ca-Cu-O high Tc superconducting materials have been prepared by means of the laser-heated pedestal growth (LHPG) method. The highest zero resistance temperature T c0 reaches is 114K, and the highest critical current density J c (77K, O T) is greater than 5000 A/cm 2 . As-grown superconducting fibers were successfully fabricated without post growth heat treatment. Amorphous materials were used for the first time to make high quality fibers. The influence of growth conditions, thermal treatment and the composition of the fibers were discussed. (author). 5 refs., 7 figs., 3 tabs

  15. AC Application of HTS Conductors in Highly Dynamic Electric Motors

    International Nuclear Information System (INIS)

    Oswald, B; Best, K-J; Setzer, M; Duffner, E; Soell, M; Gawalek, W; Kovalev, L K

    2006-01-01

    Based on recent investigations we design highly dynamic electric motors up to 400 kW and linear motors up to 120 kN linear force using HTS bulk material and HTS tapes. The introduction of HTS tapes into AC applications in electric motors needs fundamental studies on double pancake coils under transversal magnetic fields. First theoretical and experimental results on AC field distributions in double-pancake-coils and corresponding AC losses will be presented. Based on these results the simulation of the motor performance confirms extremely high power density and efficiency of both types of electric motors. Improved characteristics of rare earth permanent magnets used in our motors at low temperatures give an additional technological benefit

  16. LCA of electricity systems with high wind power penetration

    DEFF Research Database (Denmark)

    Turconi, Roberto; O' Dwyer, C. O.; Flynn, D.

    Electricity systems are shifting from being based on fossil fuels towards renewable sources to enhance energy security and mitigate climate change. However, by introducing high shares of variable renewables - such as wind and solar - dispatchable power plants are required to vary their output...... to fulfill the remaining electrical demand, potentially increasing their environmental impacts [1,2]. In this study the environmental impacts of potential short-term future electricity systems in Ireland with high shares of wind power (35-50% of total installed capacity) were evaluated using life cycle...... considered: while not outweighing the benefits from increasing wind energy, cycling emissions are not negligible and should thus be systematically included (i.e. by using emission factors per unit of fuel input rather than per unit of power generated). Cycling emissions increased with the installed wind...

  17. High Voltage Electrical Injuries In The University Of Calabar ...

    African Journals Online (AJOL)

    Even when patients present relatively early and are resuscitated and treated, complete prosthetic rehabilitation is difficult because of poverty and lack of social support systems. Case Report: This review presents three cases of high voltage electrical burns resulting from typical 11KVA burns as well as lightning strike.

  18. Proximity effects of high voltage electric power transmission lines on ...

    African Journals Online (AJOL)

    The proximity effects of high voltage electric power transmission lines on Leyland Cypress (xCupressocyparis leylandii (Dallim. and A.B. Jacks.) Dallim) and Japanese Privet (Ligustrum japonicum Thunb.) growth were examined in a private nursery located in Sakarya, Turkey. Five transect were randomly chosen in both ...

  19. Electrical and structural R&D activities on high voltage dc solid insulator in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Pilan, N., E-mail: nicola.pilan@igi.cnr.it [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy); Marcuzzi, D.; Rizzolo, A.; Grando, L.; Gambetta, G. [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy); Rosa, S. Dalla [Umicore – Italbras S.p.A., Strada del Balsego, n.6, 36100 Vicenza (Italy); Kraemer, V.; Quirmbach, T. [FRIATEC Ceramics Division, Steinzeugstrasse 50, 68229 Mannheim (Germany); Chitarin, G. [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy); Gobbo, R.; Pesavento, G. [DII, Università di Padova, v. Gradenigo 6/A, I-35131 Padova (Italy); De Lorenzi, A.; Lotto, L.; Rizzieri, R.; Fincato, M.; Romanato, L.; Trevisan, L.; Cervaro, V.; Franchin, L. [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy)

    2015-10-15

    Highlights: • A thorough R&D activity on the MITICA post insulator prototypes is being carried out. • The design has been numerically verified considering both mechanical and electrical aspects. • Experimental validation has been started, with positive results in both involved fields. • Alternative design solutions thickness have been proposed and successfully tested. - Abstract: This paper describes the R&D work performed in support of the design of the alumina insulators for the MITICA Neutral Beam Injector. The ceramic insulators are critical elements, both from the structural and electrical point of view, of the 1 MV electrostatic accelerator of the MITICA injector, as they are required to sustain both the mechanical loads due to the cantilevered weight of the ion source and the high electric field between the accelerator grids. This paper presents the results of numerical simulations and experimental tests on prototypes that have been carried out to validate the insulator design under realistic operating conditions.

  20. Electrical and structural R&D activities on high voltage dc solid insulator in vacuum

    International Nuclear Information System (INIS)

    Pilan, N.; Marcuzzi, D.; Rizzolo, A.; Grando, L.; Gambetta, G.; Rosa, S. Dalla; Kraemer, V.; Quirmbach, T.; Chitarin, G.; Gobbo, R.; Pesavento, G.; De Lorenzi, A.; Lotto, L.; Rizzieri, R.; Fincato, M.; Romanato, L.; Trevisan, L.; Cervaro, V.; Franchin, L.

    2015-01-01

    Highlights: • A thorough R&D activity on the MITICA post insulator prototypes is being carried out. • The design has been numerically verified considering both mechanical and electrical aspects. • Experimental validation has been started, with positive results in both involved fields. • Alternative design solutions thickness have been proposed and successfully tested. - Abstract: This paper describes the R&D work performed in support of the design of the alumina insulators for the MITICA Neutral Beam Injector. The ceramic insulators are critical elements, both from the structural and electrical point of view, of the 1 MV electrostatic accelerator of the MITICA injector, as they are required to sustain both the mechanical loads due to the cantilevered weight of the ion source and the high electric field between the accelerator grids. This paper presents the results of numerical simulations and experimental tests on prototypes that have been carried out to validate the insulator design under realistic operating conditions.

  1. Measuring Critical Thinking in Physics: Development and Validation of a Critical Thinking Test in Electricity and Magnetism

    Science.gov (United States)

    Tiruneh, Dawit Tibebu; De Cock, Mieke; Weldeslassie, Ataklti G.; Elen, Jan; Janssen, Rianne

    2017-01-01

    Although the development of critical thinking (CT) is a major goal of science education, adequate emphasis has not been given to the measurement of CT skills in specific science domains such as physics. Recognizing that adequately assessing CT implies the assessment of both domain-specific and domain-general CT skills, this study reports on the…

  2. Characterization of non equilibrium effects on high quality critical flows

    International Nuclear Information System (INIS)

    Camelo, E.; Lemonnier, H.; Ochterbeck, J.

    1995-01-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness

  3. Characterization of non equilibrium effects on high quality critical flows

    Energy Technology Data Exchange (ETDEWEB)

    Camelo, E.; Lemonnier, H.; Ochterbeck, J. [Commissariat a l Energie Atomique, Grenoble (France)] [and others

    1995-09-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness.

  4. Application of high temperature superconductivity to electric motor design

    International Nuclear Information System (INIS)

    Edmonds, J.S.; Sharma, D.K.; Jordan, H.E.; Edick, J.D.; Schiferl, R.F.

    1992-01-01

    This paper reports on progress made in a joint project conducted by the Electric Power Research Institute and Reliance Electric Company to study the possible application of High Temperature Super Conductors (HTSC), materials to electric motors. Specific applications are identified which can be beneficially served by motors constructed with HTSC materials. A summary is presented of the components and design issues related to HTSC motors designed for these applications. During the course of this development program, a three tier HTSC wire performance specification has evolved. The three specifications and the rationale behind these three levels of performance are explained. A description of a test motor that has been constructed to verify the electromagnetic analytical techniques of HTSC motor design is given. Finally, a DC motor with an HTSC field coil is described. Measured data with the motor running is presented showing that the motor is operating with the field winding in the superconducting state

  5. Recommended E3 HEMP Heave Electric Field Waveform for the Critical Infrastructures. Volume 2

    Science.gov (United States)

    2017-07-31

    horizontal electric (E) field, as this field can effectively couple to long power and communications lines and induce quasi-dc currents in these systems ...Department of Defense E electric field EMP electromagnetic pulse EPRI Electric Power Research Institute FERC Federal Energy Regulatory Commission GMD...North American Electric Reliability Corporation nT nanotesla S/m siemens/m UV ultraviolet V Volt ix PREFACE This EMP Commission Report

  6. A critically educated public explores high level radioactive waste management

    International Nuclear Information System (INIS)

    Blum, J.E.

    1994-01-01

    It is vital to the citizens of Nevada that they and their children are given an opportunity to explore all sides of the characterization of Yucca Mountain as a potential repository site for spent nuclear fuel. The state-wide, national and international implications demand a reasoned and complete approach to this issue, which has become emotionally and irrationally charged and fueled by incomplete perception and information. The purpose of this paper is to provide curriculum suggestions and recommend concomitant policy developments that will lead to the implementation of a Critical Thinking (CT) approach to High Level Radioactive Waste Management

  7. Protective design of critical infrastructure with high performance concretes

    International Nuclear Information System (INIS)

    Riedel, W.; Nöldgen, M.; Stolz, A.; Roller, C.

    2012-01-01

    Conclusions: High performance concrete constructions will allow innovative design solutions for critical infrastructures. Validation of engineering methods can reside on large and model scale experiments conducted on conventional concrete structures. New consistent impact experiments show extreme protection potential for UHPC. Modern FEM with concrete models and explicit rebar can model HPC and UHPC penetration resistance. SDOF and TDOF approaches are valuable design tools on local and global level. Combination of at least 2 out of 3 design methods FEM – XDOF- EXP allow reliable prediction and efficient innovative designs

  8. Highly effective cystic fibrosis clinical research teams: critical success factors.

    Science.gov (United States)

    Retsch-Bogart, George Z; Van Dalfsen, Jill M; Marshall, Bruce C; George, Cynthia; Pilewski, Joseph M; Nelson, Eugene C; Goss, Christopher H; Ramsey, Bonnie W

    2014-08-01

    Bringing new therapies to patients with rare diseases depends in part on optimizing clinical trial conduct through efficient study start-up processes and rapid enrollment. Suboptimal execution of clinical trials in academic medical centers not only results in high cost to institutions and sponsors, but also delays the availability of new therapies. Addressing the factors that contribute to poor outcomes requires novel, systematic approaches tailored to the institution and disease under study. To use clinical trial performance metrics data analysis to select high-performing cystic fibrosis (CF) clinical research teams and then identify factors contributing to their success. Mixed-methods research, including semi-structured qualitative interviews of high-performing research teams. CF research teams at nine clinical centers from the CF Foundation Therapeutics Development Network. Survey of site characteristics, direct observation of team meetings and facilities, and semi-structured interviews with clinical research team members and institutional program managers and leaders in clinical research. Critical success factors noted at all nine high-performing centers were: 1) strong leadership, 2) established and effective communication within the research team and with the clinical care team, and 3) adequate staff. Other frequent characteristics included a mature culture of research, customer service orientation in interactions with study participants, shared efficient processes, continuous process improvement activities, and a businesslike approach to clinical research. Clinical research metrics allowed identification of high-performing clinical research teams. Site visits identified several critical factors leading to highly successful teams that may help other clinical research teams improve clinical trial performance.

  9. Critical current measurements of high Tc superconductors in a scanning low temperature cryostat

    International Nuclear Information System (INIS)

    Telschow, K.L.; O'Brien, T.K.

    1991-01-01

    Maintaining uniformity of properties over long distances is one of the fabrication problems encountered with the new high T c superconductors. Uniform properties are crucial in long tapes or wires with high critical current since local nonuniformities can limit the current carrying capacity of the whole piece. Transport critical currents in high T c superconductors are conventionally measured with the contact 4-point probe DC current-voltage technique. This technique requires contact with the sample and and spatially averages over the region between the two voltage contacts. Two techniques have been used to infer the critical state model. The first uses the net magnetization of a suitably shaped sample in an external magnetic field. The second combines a DC magnetic field with AC induced currents to infer spatial flux profiles. The AC magnetization technique offers an advantage in that it is noncontacting; however, it also averages the measurement over a large area and requires that the sample be shaped and positioned such that it exhibits zero demagnetizing factor. This paper describes a measurement technique and a scanning cryostat assembly that are capable of determining local critical current in a tape or wire with high resolution and without any direct sample electrical contact. A small compensated coil was used to induce AC currents in slab-shaped samples. The coil was situated near the surface on one side of the slab. With this method, the AC probe can be used as a noncontacting dissipation probe, replacing the voltage probe in the 4-point contact method, when an externally driven transport current is used, or by itself as a local critical state generator and dissipation detector. The results are shown to be meaningful even when the internal magnetic field is not uniform due to shape demagnetizing effects. 10 refs., 5 figs

  10. Preparation and characterization of high-Tc superconducting thin films with high critical current densities

    International Nuclear Information System (INIS)

    Vase, P.

    1991-08-01

    The project was carried out in relation to possible cable and electronics applications of high-T c materials. Laser ablation was used as the deposition technique because of its stoichiometry conservation. Films were made in the YBa 2 Cu 3 O 7 compound due to its relatively simple stoichiometry compared to other High-T c compounds. Much attention was paid to the critical current density. A very high critical current density was reached. By using texture analysis by X-ray diffraction, it was found that films with high critical current densities were epitaxial, while films with low critical current densities contained several crystalline orientations. Four techniques for patterning the films were used - photo lithography and wet etch, laser ablation lithography, laser writing and electron beam lithography and ion milling. Sub-micron patterning has been demonstrated without degradation of the superconducting properties. The achieved patterning resolution is sufficient for preparation of many superconducting components. (AB)

  11. Design of a 200kW electric powertrain for a high performance electric vehicle

    Directory of Open Access Journals (Sweden)

    Wilmar Martinez

    2016-09-01

    Full Text Available With the purpose of designing the electric powertrain of a high performance electric vehicle capable of running a quarter mile in 10 seconds, firstly it is necessary to calculate the required energy, torque, and power in order to size and select the suitable storage components and electric motors. Secondly, an assessment of the powertrain arrangement is needed to choose the best internal configuration of the vehicle and guarantee the highest efficiency possible. Finally, a design of the power conversion stages, specifically the DC-DC converter that interfaces the storage unit with the electric motors, is required as well. This paper shows the energy calculation procedure based on a longitudinal dynamic model of the vehicle and the selection method of the storage components and motors needed for this application, as well as the design of two 100kW interleaved boost converters with coupled inductors. In addition, a novel operation of the interleaved boost converter is proposed in order to increase the efficiency of the converter. As a result, the designed converter achieved a power density of 24,2kW/kg with an efficiency of 98 %, which was validated by experimental tests of a low power prototype.

  12. Critical Role of Monoclinic Polarization Rotation in High-Performance Perovskite Piezoelectric Materials.

    Science.gov (United States)

    Liu, Hui; Chen, Jun; Fan, Longlong; Ren, Yang; Pan, Zhao; Lalitha, K V; Rödel, Jürgen; Xing, Xianran

    2017-07-07

    High-performance piezoelectric materials constantly attract interest for both technological applications and fundamental research. The understanding of the origin of the high-performance piezoelectric property remains a challenge mainly due to the lack of direct experimental evidence. We perform in situ high-energy x-ray diffraction combined with 2D geometry scattering technology to reveal the underlying mechanism for the perovskite-type lead-based high-performance piezoelectric materials. The direct structural evidence reveals that the electric-field-driven continuous polarization rotation within the monoclinic plane plays a critical role to achieve the giant piezoelectric response. An intrinsic relationship between the crystal structure and piezoelectric performance in perovskite ferroelectrics has been established: A strong tendency of electric-field-driven polarization rotation generates peak piezoelectric performance and vice versa. Furthermore, the monoclinic M_{A} structure is the key feature to superior piezoelectric properties as compared to other structures such as monoclinic M_{B}, rhombohedral, and tetragonal. A high piezoelectric response originates from intrinsic lattice strain, but little from extrinsic domain switching. The present results will facilitate designing high-performance perovskite piezoelectric materials by enhancing the intrinsic lattice contribution with easy and continuous polarization rotation.

  13. Advanced electrical current measurements of microdischarges: evidence of sub-critical pulses and ion currents in barrier discharge in air

    Science.gov (United States)

    Synek, Petr; Zemánek, Miroslav; Kudrle, Vít; Hoder, Tomáš

    2018-04-01

    Electrical current measurements in corona or barrier microdischarges are a challenge as they require both high temporal resolution and a large dynamic range of the current probe used. In this article, we apply a simple self-assembled current probe and compare it to commercial ones. An analysis in the time and frequency domain is carried out. Moreover, an improved methodology is presented, enabling both temporal resolution in sub-nanosecond times and current sensitivity in the order of tens of micro-amperes. Combining this methodology with a high-tech oscilloscope and self-developed software, a unique statistical analysis of currents in volume barrier discharge driven in atmospheric-pressure air is made for over 80 consecutive periods of a 15 kHz applied voltage. We reveal the presence of repetitive sub-critical current pulses and conclude that these can be identified with the discharging of surface charge microdomains. Moreover, extremely low, long-lasting microsecond currents were detected which are caused by ion flow, and are analysed in detail. The statistical behaviour presented gives deeper insight into the discharge physics of these usually undetectable current signals.

  14. Cryogenics Vision Workshop for High-Temperature Superconducting Electric Power Systems Proceedings

    International Nuclear Information System (INIS)

    Energetics, Inc.

    2000-01-01

    The US Department of Energy's Superconductivity Program for Electric Systems sponsored the Cryogenics Vision Workshop, which was held on July 27, 1999 in Washington, D.C. This workshop was held in conjunction with the Program's Annual Peer Review meeting. Of the 175 people attending the peer review meeting, 31 were selected in advance to participate in the Cryogenics Vision Workshops discussions. The participants represented cryogenic equipment manufactures, industrial gas manufacturers and distributors, component suppliers, electric power equipment manufacturers (Superconductivity Partnership Initiative participants), electric utilities, federal agencies, national laboratories, and consulting firms. Critical factors were discussed that need to be considered in describing the successful future commercialization of cryogenic systems. Such systems will enable the widespread deployment of high-temperature superconducting (HTS) electric power equipment. Potential research, development, and demonstration (RD and D) activities and partnership opportunities for advancing suitable cryogenic systems were also discussed. The workshop agenda can be found in the following section of this report. Facilitated sessions were held to discuss the following specific focus topics: identifying Critical Factors that need to be included in a Cryogenics Vision for HTS Electric Power Systems (From the HTS equipment end-user perspective) identifying R and D Needs and Partnership Roles (From the cryogenic industry perspective) The findings of the facilitated Cryogenics Vision Workshop were then presented in a plenary session of the Annual Peer Review Meeting. Approximately 120 attendees participated in the afternoon plenary session. This large group heard summary reports from the workshop session leaders and then held a wrap-up session to discuss the findings, cross-cutting themes, and next steps. These summary reports are presented in this document. The ideas and suggestions raised during

  15. High Resolution Global Electrical Conductivity Variations in the Earth's Mantle

    Science.gov (United States)

    Kelbert, A.; Sun, J.; Egbert, G. D.

    2013-12-01

    Electrical conductivity of the Earth's mantle is a valuable constraint on the water content and melting processes. In Kelbert et al. (2009), we obtained the first global inverse model of electrical conductivity in the mantle capable of providing constraints on the lateral variations in mantle water content. However, in doing so we had to compromise on the problem complexity by using the historically very primitive ionospheric and magnetospheric source assumptions. In particular, possible model contamination by the auroral current systems had greatly restricted our use of available data. We have now addressed this problem by inverting for the external sources along with the electrical conductivity variations. In this study, we still focus primarily on long period data that are dominated by quasi-zonal source fields. The improved understanding of the ionospheric sources allows us to invert the magnetic fields directly, without a correction for the source and/or the use of transfer functions. It allows us to extend the period range of available data to 1.2 days - 102 days, achieving better sensitivity to the upper mantle and transition zone structures. Finally, once the source effects in the data are accounted for, a much larger subset of observatories may be used in the electrical conductivity inversion. Here, we use full magnetic fields at 207 geomagnetic observatories, which include mid-latitude, equatorial and high latitude data. Observatory hourly means from the years 1958-2010 are employed. The improved quality and spatial distribution of the data set, as well as the high resolution modeling and inversion using degree and order 40 spherical harmonics mapped to a 2x2 degree lateral grid, all contribute to the much improved resolution of our models, representing a conceptual step forward in global electromagnetic sounding. We present a fully three-dimensional, global electrical conductivity model of the Earth's mantle as inferred from ground geomagnetic

  16. Electrical resistivity of UBe13 in high magnetic fields

    International Nuclear Information System (INIS)

    Schmiedeshoff, G.M.; Lacerda, A.; Fisk, Z.; Smith, J.L.

    1996-01-01

    We have measured the temperature dependent electrical resistivity of single and polycrystal samples of UBe 13 in high magnetic fields. Two maxima in the resistivity are observed at T M1 and T M2 . T M1 , the temperature of the colder maximum, increases quadratically with magnetic field H, a field dependence previously observed under hydrostatic pressure. The high temperature maximum at T M2 emerges in fields above about 4 T and increases linearly with H, a behavior which may be due to a sharpening of the crystal field levels associated with a depression of the Kondo effect by high magnetic fields. copyright 1996 The American Physical Society

  17. Behavior of Rubber Materials under Exposure to High Electric Fields

    DEFF Research Database (Denmark)

    Candela Garolera, Anna; Holbøll, Joachim; Henriksen, M,

    2013-01-01

    The effect of high electrical stress on rubber materials is investigated by performing breakdown tests and tracking resistance tests on selected samples. The study is focused on the relationship between the dielectric strength and the thickness of the samples, as well as the influence of the inte......The effect of high electrical stress on rubber materials is investigated by performing breakdown tests and tracking resistance tests on selected samples. The study is focused on the relationship between the dielectric strength and the thickness of the samples, as well as the influence...... of the interfaces between different layers of material. Tracking resistance tests are also performed on the rubber material. The purpose is to provide a complete study of the applicability of the rubber material in thunderstorm environments....

  18. 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...... 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...... represents the avant-garde of InP technology, with ft and fmax well above 300 GHz. Principles of high speed design are presented and described as a useful background before proceeding to circuits. A static divider is used as an example to illustrate many of the design principles. Theory and fundamentals...

  19. High temperature heat capacities and electrical conductivities of boron carbides

    International Nuclear Information System (INIS)

    Matsui, Tsuneo; Arita, Yuri; Naito, Keiji; Imai, Hisashi

    1991-01-01

    The heat capacities and the electrical conductivities of B x C(x=3, 4, 5) were measured by means of direct heating pulse calorimetry in the temperature range from 300 to 1500 K. The heat capacities of B x C increased with increasing x value. This increase in the heat capacity is probably related to the change of the lattice vibration mode originated from the reduction of the stiffness of the intericosahedral chain accompanied with a change from C-B-C to C-B-B chains. A linear relationship between the logarithm of σT (σ is the electrical conductivity and T is the absolute temperature) of B x C and the reciprocal temperature was observed, indicating the presence of small polaron hopping as the predominant conduction mechanism. The electrical conductivity of B x C also increased with increasing x value (from 4 to 5) due to an increase of the polaron hopping of holes between carbon atoms at geometrically nonequivalent sites, since these nonequivalent sites of carbon atoms were considered to increase in either B 11 C icosahedra or in icosahedral chains with increasing x. The electrical conductivity of B 3 C was higher than that of B 4 C, which is probably due to the precipitation of high-conducting carbon. The thermal conductivity and the thermodynamic quantities of B 4 C were also determined precisely from the heat capacity value. (orig.)

  20. High energy XeBr electric discharge laser

    Science.gov (United States)

    Sze, Robert C.; Scott, Peter B.

    1981-01-01

    A high energy XeBr laser for producing coherent radiation at 282 nm. The XeBr laser utilizes an electric discharge as the excitation source to minimize formation of molecular ions thereby minimizing absorption of laser radiation by the active medium. Additionally, HBr is used as the halogen donor which undergoes harpooning reactions with Xe.sub.M * to form XeBr*.

  1. Breakdown of highly excited oxygen in a DC electric field

    International Nuclear Information System (INIS)

    Vagin, N.P.; Ionin, A.A.; Klimachev, Yu.M.; Sinitsin, D.V.; Yuryshev, N.N.; Deryugin, A.A.; Kochetov, I.V.; Napartovich, A.P.

    2000-01-01

    The breakdown of oxygen in a dc electric field is studied. A high concentration of oxygen molecules in the a 1 Δ g excited state is obtained in a purely chemical reactor. A decrease in the breakdown voltage at degrees of excitation exceeding 50% is observed. The theoretical decrement in the breakdown voltage obtained by solving the Boltzmann equation is in good agreement with the experimental data

  2. [Extensive injuries due to high-tension electrical current].

    Science.gov (United States)

    Tomásek, D; Königová, R; Snupárek, Z

    1989-03-01

    The authors submit a case of severe injury with high tension electric current. They emphasize the necessity of prevention of this injury which occurs most frequently when transformer stations are not adequately safeguarded, in case of inadequate protection when approaching trolley wires on the railway track, and when safety principles are not respected during work on the railway. The authors draw attention to the importance of immediate resuscitation and multidisciplinary comprehensive care.

  3. Neuromuscular electrical stimulation for preventing skeletal-muscle weakness and wasting in critically ill patients

    DEFF Research Database (Denmark)

    Maffiuletti, Nicola A.; Roig, Marc; Karatzanos, Eleftherios

    2013-01-01

    ill patients, in comparison with usual care. Methods: We searched PubMed, CENTRAL, CINAHL, Web of Science, and PEDro to identify randomized controlled trials exploring the effect of NMES in critically ill patients, which had a well-defined NMES protocol, provided outcomes related to skeletal......-muscle strength and/or mass, and for which full text was available. Two independent reviewers extracted data on muscle-related outcomes (strength and mass), and participant and intervention characteristics, and assessed the methodological quality of the studies. Owing to the lack of means and standard deviations...... yielded 8 eligible studies involving 172 patients. The methodological quality of the studies was moderate to high. Five studies reported an increase in strength or better preservation of strength with NMES, with one study having a large effect size. Two studies found better preservation of muscle mass...

  4. Critical behavior of electrical resistivity in amorphous Fe–Zr alloys

    Indian Academy of Sciences (India)

    Analysis of the resistivity data particularly in the critical region reveals that these systems have a much wider range of critical region compared to other crystalline ferromagnetic materials. The value of and specific heat critical exponent, has the same values as those determined from our earlier magnetic measurements ...

  5. Meeting Ontario's electricity needs : a critical review of the Ontario Power Authority's supply mix advice report

    International Nuclear Information System (INIS)

    Gibbons, J.; Fracassi, J.

    2006-01-01

    In December, 2005 the Ontario Power Authority (OPA) outlined its proposed blueprint for meeting Ontario's electricity needs to 2025 in the document entitled Supply Mix Advice Report. As a result of the actions taken by the current government, the OPA believes that Ontario will have adequate electricity supplies to meet the province's needs until 2013. However, it stated that Ontario will require an additional 15,000 megawatts of new generation capacity between 2013 and 2025. The OPA also recommends that a significant proportion of this new generation capacity be nuclear. The Ontario Clean Air Alliance undertook a review of the OPA report and identified several discrepancies including an over-estimation of Ontario's rate of electricity load growth from 2005 to 2025; an under-estimation of the potential for electricity productivity improvements to reduce electricity demand and raise living standards; an under-estimation of renewable energy supply potential; an under-estimation of the potential for biomass and natural gas fired combined heat and power plants to meet electricity needs and increase the competitiveness of Ontario's industries; an under-estimation of the economic costs and risks of nuclear power; and a biased recommendation for a 70 million dollar resource acquisition budget against energy efficiency investments that would reduce demand and raise living standards. This report provides the Ontario Clean Air Alliances' analysis of the OPA report and presents it own recommendations for how Ontario can increase its electricity productivity and meet its electricity supply needs until 2025. The report concluded that the Government of Ontario should direct the OPA to develop a long-term strategy to raise the price of electricity up to its full cost without raising the electricity bills of low income consumers or impairing the competitiveness of Ontario's industries. It was suggested that Ontario's electricity productivity should be increased to the same level as

  6. Thermal and electrical conductivities of high purity tantalum

    International Nuclear Information System (INIS)

    Archer, S.L.

    1978-01-01

    The electrical resistivity and thermal conductivity of three high purity tantalum samples have been measured as functions of temperature over a temperature range of 5K to 65K. Sample purities ranged up to a resistivity ratio of 1714. The highest purity sample had a residual resistivity of .76 x 10 -10 OMEGA-m. The intrinsic resistivity varied as T 3 . 9 from 10K to 31K. The thermal conductivity of the purest sample had a maximum of 840 W/mK at 9.8K. The intrinsic thermal resistivity varied as T 2 . 4 from 10K to 35K. At low temperatures electrons were scattered primarily by impurities and by phonons with both interband and intraband transitions observed. The electrical and thermal resistivity is departed from Matthiessen's rule at low temperatures

  7. Properties of partially ionized hydrogen plasmas in high electric fields

    International Nuclear Information System (INIS)

    Morawetz, K.

    1993-03-01

    In this thesis the fundamental equations of many-particle quantum-statistics of nonequilibrium are treated in respect to arbitrary high electric fields. Generalizations are found for the T-matrix approximation as well as for the shielded potential approximation valid for any field strength. These result in a non-Markovian behavior of the obtained collision integrals, also known as intra-collisional-field-effect (ICFE), and in a broadening of the energy conservation, the so-called collisional broadening (CB), caused by applied electric fields. In linear response it is shown in a new way, how the Debye-Onsager relaxation effect can be rederived from these collision integrals. Furthermore the complete quantum result is presented. Both effects, ICFE and CB, contribute to the right classical limit. The quantum result yields an surprising maximum of this field effects in dependence of the interacting mass ratio, which may be important in exciton-plasmas and semiconductors. (orig.)

  8. Pulsed high voltage electric discharge disinfection of microbially contaminated liquids.

    Science.gov (United States)

    Anpilov, A M; Barkhudarov, E M; Christofi, N; Kop'ev, V A; Kossyi, I A; Taktakishvili, M I; Zadiraka, Y

    2002-01-01

    To examine the use of a novel multielectrode slipping surface discharge (SSD) treatment system, capable of pulsed plasma discharge directly in water, in killing micro-organisms. Potable water containing Escherichia coli and somatic coliphages was treated with pulsed electric discharges generated by the SSD. The SSD system was highly efficient in the microbial disinfection of water with a low energy utilization (eta approximately 10-4 kW h l-1). The SSD treatment was effective in the destruction of E. coli and its coliphages through the generation of u.v. radiation, ozone and free radicals. The non-thermal treatment method can be used for the eradication of micro-organisms in a range of contaminated liquids, including milk, negating the use of pasteurization. The method utilizes multipoint electric discharges capable of treating large volumes of liquid under static and flowing regimes.

  9. Review of electric discharge microplasmas generated in highly fluctuating fluids: Characteristics and application to nanomaterials synthesis

    International Nuclear Information System (INIS)

    Stauss, Sven; Terashima, Kazuo; Muneoka, Hitoshi; Urabe, Keiichiro

    2015-01-01

    Plasma-based fabrication of novel nanomaterials and nanostructures is indispensible for the development of next-generation electronic devices and for green energy applications. In particular, controlling the interactions between plasmas and materials interfaces, and the plasma fluctuations, is crucial for further development of plasma-based processes and bottom-up growth of nanomaterials. Electric discharge microplasmas generated in supercritical fluids represent a special class of high-pressure plasmas, where fluctuations on the molecular scale influence the discharge properties and the possible bottom-up growth of nanomaterials. This review discusses an anomaly observed for direct current microplasmas generated near the critical point, a local decrease in the breakdown voltage. This anomalous behavior is suggested to be caused by the concomitant decrease of the ionization potential due to the formation of clusters near the critical point, and the formation of extended electron mean free paths caused by the high-density fluctuation near the critical point. It is also shown that in the case of dielectric barrier microdischarges generated close to the critical point, the high-density fluctuation of the supercritical fluid persists. The final part of the review discusses the application of discharges generated in supercritical fluids to synthesis of nanomaterials, in particular, molecular diamond—so-called diamondoids—by microplasmas generated inside conventional batch-type and continuous flow microreactors

  10. What happens in Josephson junctions at high critical current densities

    Science.gov (United States)

    Massarotti, D.; Stornaiuolo, D.; Lucignano, P.; Caruso, R.; Galletti, L.; Montemurro, D.; Jouault, B.; Campagnano, G.; Arani, H. F.; Longobardi, L.; Parlato, L.; Pepe, G. P.; Rotoli, G.; Tagliacozzo, A.; Lombardi, F.; Tafuri, F.

    2017-07-01

    The impressive advances in material science and nanotechnology are more and more promoting the use of exotic barriers and/or superconductors, thus paving the way to new families of Josephson junctions. Semiconducting, ferromagnetic, topological insulator and graphene barriers are leading to unconventional and anomalous aspects of the Josephson coupling, which might be useful to respond to some issues on key problems of solid state physics. However, the complexity of the layout and of the competing physical processes occurring in the junctions is posing novel questions on the interpretation of their phenomenology. We classify some significant behaviors of hybrid and unconventional junctions in terms of their first imprinting, i.e., current-voltage curves, and propose a phenomenological approach to describe some features of junctions characterized by relatively high critical current densities Jc. Accurate arguments on the distribution of switching currents will provide quantitative criteria to understand physical processes occurring in high-Jc junctions. These notions are universal and apply to all kinds of junctions.

  11. Nucleon electric dipole moments in high-scale supersymmetric models

    International Nuclear Information System (INIS)

    Hisano, Junji; Kobayashi, Daiki; Kuramoto, Wataru; Kuwahara, Takumi

    2015-01-01

    The electric dipole moments (EDMs) of electron and nucleons are promising probes of the new physics. In generic high-scale supersymmetric (SUSY) scenarios such as models based on mixture of the anomaly and gauge mediations, gluino has an additional contribution to the nucleon EDMs. In this paper, we studied the effect of the CP-violating gluon Weinberg operator induced by the gluino chromoelectric dipole moment in the high-scale SUSY scenarios, and we evaluated the nucleon and electron EDMs in the scenarios. We found that in the generic high-scale SUSY models, the nucleon EDMs may receive the sizable contribution from the Weinberg operator. Thus, it is important to compare the nucleon EDMs with the electron one in order to discriminate among the high-scale SUSY models.

  12. Nucleon electric dipole moments in high-scale supersymmetric models

    Energy Technology Data Exchange (ETDEWEB)

    Hisano, Junji [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI),Nagoya University,Nagoya 464-8602 (Japan); Department of Physics, Nagoya University,Nagoya 464-8602 (Japan); Kavli IPMU (WPI), UTIAS, University of Tokyo,Kashiwa, Chiba 277-8584 (Japan); Kobayashi, Daiki; Kuramoto, Wataru; Kuwahara, Takumi [Department of Physics, Nagoya University,Nagoya 464-8602 (Japan)

    2015-11-12

    The electric dipole moments (EDMs) of electron and nucleons are promising probes of the new physics. In generic high-scale supersymmetric (SUSY) scenarios such as models based on mixture of the anomaly and gauge mediations, gluino has an additional contribution to the nucleon EDMs. In this paper, we studied the effect of the CP-violating gluon Weinberg operator induced by the gluino chromoelectric dipole moment in the high-scale SUSY scenarios, and we evaluated the nucleon and electron EDMs in the scenarios. We found that in the generic high-scale SUSY models, the nucleon EDMs may receive the sizable contribution from the Weinberg operator. Thus, it is important to compare the nucleon EDMs with the electron one in order to discriminate among the high-scale SUSY models.

  13. High voltage diagnostics on electrical insulation of supersonducting magnets

    International Nuclear Information System (INIS)

    Irmisch, M.

    1995-12-01

    The high voltage (HV) performance of superconducting magnets of large dimensions, e.g. as needed in fusion reactors, is a challange in the field of high voltage technology, i.e. especially in the field of cryogenic high voltage components and with respect to questions of HV insulation diagnostics at low temperature. By using the development of POLO - a superconducting prototype coil of a tokamak poloidal field coil - as an example, this work deals with special problems of how to get use of conventional HV test techniques for diagnostics under special cryogenic boundary conditions. As a first approach to gain experience in the field of phase resolved partial discharge (PRPD) measurements during operation of a superconductive coil, the POLO coil was subject to several high voltage tests. Compared with DC insulation resistance measurements and capacitive impulse voltage discharges to the coil, the AC PD measurements have been the only way to observe special characteristics of the electrical insulation with respect to the cooling down of the coil from 300 K to 4.2 K. The PRPD measurement technique thereby has proofed as a suitable diagnostic tool. This work can serve as basic data to be comparable within further projects of electrical insulation diagnostics at cryogenic temperatures. (orig.)

  14. High-authority smart material integrated electric actuator

    Science.gov (United States)

    Weisensel, G. N.; Pierce, Thomas D.; Zunkel, Gary

    1997-05-01

    For many current applications, hydraulic power is still the preferred method of gaining mechanical advantage. However, in many of these applications, this power comes with the penalties of high weight, size, cost, and maintenance due to the system's distributed nature and redundancy requirements. A high authority smart material Integrated Electric Actuator (IEA) is a modular, self-contained linear motion device that is capable of producing dynamic output strokes similar to those of hydraulic actuators yet at significantly reduced weight and volume. It provides system simplification and miniaturization. This actuator concept has many innovative features, including a TERFENOL-D-based pump, TERFENOL-D- based active valves, control algorithms, a displacement amplification unit and integrated, unitized packaging. The IEA needs only electrical power and a control command signal as inputs to provide high authority, high response rate actuation. This approach is directly compatible with distributed control strategies. Aircraft control, automotive brakes and fuel injection, and fluid power delivery are just some examples of the IEA's pervasive applications in aerospace, defense and commercial systems.

  15. Improving NASICON Sinterability through Crystallization under High Frequency Electrical Fields

    Directory of Open Access Journals (Sweden)

    Ilya eLisenker

    2016-03-01

    Full Text Available The effect of high frequency (HF electric fields on the crystallization and sintering rates of a lithium aluminum germanium phosphate (LAGP ion conducting ceramic was investigated. LAGP with the nominal composition Li1.5Al0.5Ge1.5(PO43 was crystallized and sintered, both conventionally and under effect of electrical field. Electrical field application, of 300V/cm at 1MHz, produced up to a 40% improvement in sintering rate of LAGP that was crystallized and sintered under the HF field. Heat sink effect of the electrodes appears to arrest thermal runaway and subsequent flash behavior. Sintered pellets were characterized using XRD, SEM, TEM and EIS to compare conventionally and field sintered processes. The as-sintered structure appears largely unaffected by the field as the sintering curves tend to converge beyond initial stages of sintering. Differences in densities and microstructure after 1 hour of sintering were minor with measured sintering strains of 31% vs. 26% with and without field, respectively . Ionic conductivity of the sintered pellets was evaluated and no deterioration due to the use of HF field was noted, though capacitance of grain boundaries due to secondary phases was significantly increased.

  16. Electrical and optical properties of highly oriented nanocrystalline vanadium pentoxide

    International Nuclear Information System (INIS)

    Bahgat, A.A.; Ibrahim, F.A.; El-Desoky, M.M.

    2005-01-01

    Highly oriented nanocrystalline hydrated vanadium pentoxide, V 2 O 5 .nH 2 O, were grown epitaxially on a glass substrate along the c-axis to form a film of 200 nm thick. The films were prepared by dissolving V 2 O 5 powder in hydrogen peroxide, H 2 O 2 , solution. X-ray diffraction, transmission electron micrograph and electron diffraction were used to identify the structure of the obtained nanocrystals. Homogenous nanocrystals of 7.0 ± 1.0 nm in size were obtained and were closed packed and are distributed evenly. Electrical conductivity and thermoelectric power were measured in the temperature range 300-480 K for the as prepared films parallel to the substrate surface; i.e. normal to the c-axis. The obtained results showed an n-type semiconducting behavior within the whole temperature range. It is also clear to see that a reversible abnormality at about 340 K is realized during the cooling electrical conductivity measurements. On the other hand, optical transmission and reflection were used to evaluate different optical parameters such as; optical band gap, nature of donor levels and different absorption bands parameters. Both the electrical and optical data are correlated and accordingly the conduction mechanism is verified. Electronic parameters such as effective mass, carriers' type and concentration and drift mobility were evaluated

  17. Criticality issues with highly enriched fuels in a repository environment

    International Nuclear Information System (INIS)

    Taylor, L.L.; Sanchez, L.C.; Rath, J.S.

    1998-03-01

    This paper presents preliminary analysis of a volcanic tuff repository containing a combination of low enrichment commercial spent nuclear fuels (SNF) and DOE-owned SNF packages. These SNFs were analyzed with respect to their criticality risks. Disposal of SNF packages containing significant fissile mass within a geologic repository must comply with current regulations relative to criticality safety during transportation and handling within operational facilities. However, once the repository is closed, the double contingency credits for criticality safety are subject to unremediable degradation, (e.g., water intrusion, continued presence of neutron absorbers in proximity to fissile material, and fissile material reconfiguration). The work presented in this paper focused on two attributes of criticality in a volcanic tuff repository for near-field and far-field scenarios: (1) scenario conditions necessary to have a criticality, and (2) consequences of a nuclear excursion that are components of risk. All criticality consequences are dependent upon eventual water intrusion into the repository and subsequent breach of the disposal package. Key criticality parameters necessary for a critical assembly are: (1) adequate thermal fissile mass, (2) adequate concentration of fissile material, (3) separation of neutron poison from fissile materials, and (4) sufficient neutron moderation (expressed in units of moderator to fissile atom ratios). Key results from this study indicated that the total energies released during a single excursion are minimal (comparable to those released in previous solution accidents), and the maximum frequency of occurrence is bounded by the saturation and temperature recycle times, thus resulting in small criticality risks

  18. Impacts on the Electrical System Economics from Critical Design Factors of Wave Energy Converters and Arrays

    OpenAIRE

    Sharkey, Fergus; Conlon, Michael; Gaughan, Kevin

    2013-01-01

    It is expected that ultimately, like offshore wind farms, electrical systems will make up to a quarter of the overall Capex of wave farms. This is a significant element of cost and consideration must be taken in the design of both individual wave energy converters (WECs) and arrays of WECs to ensure that these costs can be minimised. In a worst case scenario design decisions could increase the cost of the electrical system by several orders and ultimately make the technology uncompetitive. ...

  19. Development and bottlenecks of renewable electricity generation in China: a critical review.

    Science.gov (United States)

    Hu, Yuanan; Cheng, Hefa

    2013-04-02

    This review provides an overview on the development and status of electricity generation from renewable energy sources, namely hydropower, wind power, solar power, biomass energy, and geothermal energy, and discusses the technology, policy, and finance bottlenecks limiting growth of the renewable energy industry in China. Renewable energy, dominated by hydropower, currently accounts for more than 25% of the total electricity generation capacity. China is the world's largest generator of both hydropower and wind power, and also the largest manufacturer and exporter of photovoltaic cells. Electricity production from solar and biomass energy is at the early stages of development in China, while geothermal power generation has received little attention recently. The spatial mismatch in renewable energy supply and electricity demand requires construction of long-distance transmission networks, while the intermittence of renewable energy poses significant technical problems for feeding the generated electricity into the power grid. Besides greater investment in research and technology development, effective policies and financial measures should also be developed and improved to better support the healthy and sustained growth of renewable electricity generation. Meanwhile, attention should be paid to the potential impacts on the local environment from renewable energy development, despite the wider benefits for climate change.

  20. Lightweight High Efficiency Electric Motors for Space Applications

    Science.gov (United States)

    Robertson, Glen A.; Tyler, Tony R.; Piper, P. J.

    2011-01-01

    Lightweight high efficiency electric motors are needed across a wide range of space applications from - thrust vector actuator control for launch and flight applications to - general vehicle, base camp habitat and experiment control for various mechanisms to - robotics for various stationary and mobile space exploration missions. QM Power?s Parallel Path Magnetic Technology Motors have slowly proven themselves to be a leading motor technology in this area; winning a NASA Phase II for "Lightweight High Efficiency Electric Motors and Actuators for Low Temperature Mobility and Robotics Applications" a US Army Phase II SBIR for "Improved Robot Actuator Motors for Medical Applications", an NSF Phase II SBIR for "Novel Low-Cost Electric Motors for Variable Speed Applications" and a DOE SBIR Phase I for "High Efficiency Commercial Refrigeration Motors" Parallel Path Magnetic Technology obtains the benefits of using permanent magnets while minimizing the historical trade-offs/limitations found in conventional permanent magnet designs. The resulting devices are smaller, lower weight, lower cost and have higher efficiency than competitive permanent magnet and non-permanent magnet designs. QM Power?s motors have been extensively tested and successfully validated by multiple commercial and aerospace customers and partners as Boeing Research and Technology. Prototypes have been made between 0.1 and 10 HP. They are also in the process of scaling motors to over 100kW with their development partners. In this paper, Parallel Path Magnetic Technology Motors will be discussed; specifically addressing their higher efficiency, higher power density, lighter weight, smaller physical size, higher low end torque, wider power zone, cooler temperatures, and greater reliability with lower cost and significant environment benefit for the same peak output power compared to typically motors. A further discussion on the inherent redundancy of these motors for space applications will be provided.

  1. WARRIOR II, a high performance modular electric robot system

    International Nuclear Information System (INIS)

    Downton, G.C.

    1996-01-01

    Initially designed for in-reactor welding by the Central Electricity Generating Board, WARRIOR has been developed using the concept of modular technology to become a light-weight, high performance robotic system. Research work on existing machines for in-reactor inspection and repair and heavy duty hydraulic manipulators was progressed in order to develop WARRIOR II, a versatile in-reactor welding system usable at any nuclear power station light enough to be deployed by existing remote handling equipment. WARRIOR II can be significantly reconfigured quickly to pursue different ends. (UK)

  2. Progress in DOE high temperature superconductivity electric power applications program

    International Nuclear Information System (INIS)

    Daley, J.G.; Sheahn, T.P.

    1992-01-01

    The Department of Energy (DOE) leads national R and D effort to develop US industry's capability to produce a wide range of advanced energy-efficient electric power products. The immediate need is to make high temperature superconductivity (HTS) wire. Wire developers at the DOE National laboratories are working wit industrial partners toward this objective. In this paper, the authors describe the progress to date, citing both the difficulties associated with making wire from these ceramic materials, and achievements at several organizations. Results for progress over the next five years are stated

  3. Static and dynamic high power, space nuclear electric generating systems

    International Nuclear Information System (INIS)

    Wetch, J.R.; Begg, L.L.; Koester, J.K.

    1985-01-01

    Space nuclear electric generating systems concepts have been assessed for their potential in satisfying future spacecraft high power (several megawatt) requirements. Conceptual designs have been prepared for reactor power systems using the most promising static (thermionic) and the most promising dynamic conversion processes. Component and system layouts, along with system mass and envelope requirements have been made. Key development problems have been identified and the impact of the conversion process selection upon thermal management and upon system and vehicle configuration is addressed. 10 references

  4. Upper critical field measurements in high-Tc superconducting oxides

    Science.gov (United States)

    Ousset, J. C.; Bobo, J. F.; Ulmet, J. P.; Rakoto, H.; Cheggour, N.

    We present upper critical field measurements on the superconducting oxides RE Ba2Cu3O7-δ (RE = Y, Gd) performed in a pulsed magnetic field up to 43 T. Values for Hc2 as high as 52 T and 77 T for Y and Gd respectively, are expected at 77 K. However, in order to observe no resistive behaviour up to 43 T the temperature must be decreased down to 50 K. In the case of oxygen deficient systems the magnetoresistance reveals two superconducting phases wich could be related to two different orders of oxygen vacancies. Nous présentons des mesures de champ critique Hc2 sur les supraconducteurs TR Ba 2Cu3O7-δ (TR = Y, Gd) réalisées en champ magnétique pulsé jusqu'à 43 T. Elles permettent de prévoir des valeurs de H c2 de 52 T et 77 T respectivement pour Y et Gd à 77 K. Cependant, pour ne pas observer de comportement résistif jusqu'au champ maximum, il est nécessaire de refroidir l'échantillon jusqu'à 50 K. Dans le cas des systèmes déficients en oxygène (δ important) nous mettons en évidence l'existence de deux phases supraconductrices qui pourraient être dues à deux ordres différents des lacunes d'oxygène.

  5. A High-power Electric Propulsion Test Platform in Space

    Science.gov (United States)

    Petro, Andrew J.; Reed, Brian; Chavers, D. Greg; Sarmiento, Charles; Cenci, Susanna; Lemmons, Neil

    2005-01-01

    This paper will describe the results of the preliminary phase of a NASA design study for a facility to test high-power electric propulsion systems in space. The results of this design study are intended to provide a firm foundation for subsequent detailed design and development activities leading to the deployment of a valuable space facility. The NASA Exploration Systems Mission Directorate is sponsoring this design project. A team from the NASA Johnson Space Center, Glenn Research Center, the Marshall Space Flight Center and the International Space Station Program Office is conducting the project. The test facility is intended for a broad range of users including government, industry and universities. International participation is encouraged. The objectives for human and robotic exploration of space can be accomplished affordably, safely and effectively with high-power electric propulsion systems. But, as thruster power levels rise to the hundreds of kilowatts and up to megawatts, their testing will pose stringent and expensive demands on existing Earth-based vacuum facilities. These considerations and the human access to near-Earth space provided by the International Space Station (ISS) have led to a renewed interest in space testing. The ISS could provide an excellent platform for a space-based test facility with the continuous vacuum conditions of the natural space environment and no chamber walls to modify the open boundary conditions of the propulsion system exhaust. The test platform could take advantage of the continuous vacuum conditions of the natural space environment. Space testing would provide open boundary conditions without walls, micro-gravity and a realistic thermal environment. Testing on the ISS would allow for direct observation of the test unit, exhaust plume and space-plasma interactions. When necessary, intervention by on-board personnel and post-test inspection would be possible. The ISS can provide electrical power, a location for

  6. Critical success factors for BOT electric power projects in China: Thermal power versus wind power

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zhen-Yu. [School of Business Administration, North China Electric Power University, Beijing 102206 (China); Zuo, Jian; Zillante, George [School of Natural and Built Environments, University of South Australia, Adelaide 5001 (Australia); Wang, Xin-Wei [Shandong Nuclear Power Equipment Manufacturing Co. Ltd, Haiyang, Shandong 265118 (China)

    2010-06-15

    Chinese electric power industry has adopted Build-Operate-Transfer (BOT) approach in a number of projects to alleviate the pressure of sole state-owned investment. The Chinese government has taken enormous efforts to create an environment to facilitate the application of BOT approach in electric power projects. Moreover, the growing attention on the sustainability issues puts the traditional major source of electricity - thermal power project under more strict scrutiny. As a result, various renewable energy projects, particularly the wind power projects have involved private sector funds. Both thermal power and wind power projects via BOT approach have met with a varying degree of success. Therefore, it is imperative to understand the factors contributing towards the success of both types of BOT power projects. Using an extensive literature survey, this paper identifies 31 success factors under 5 categories for Chinese BOT electric power projects. This is followed by a questionnaire survey to exam relative significance of these factors. The results reveal the different levels of significance of success factors for BOT thermal power projects versus wind power projects. Finally, survey results were analyzed to explore the underlying construction and distributions among the identified success factors. This study provides a valuable reference for all involved parties that are interested in developing BOT electric power projects in China. (author)

  7. Very High Efficiency Reactor (VHER) Concepts for Electrical Power Generation and Hydrogen Production

    International Nuclear Information System (INIS)

    PARMA JR, EDWARD J.; PICKARD, PAUL S.; SUO-ANTTILA, AHTI JORMA

    2003-01-01

    The goal of the Very High Efficiency Reactor study was to develop and analyze concepts for the next generation of nuclear power reactors. The next generation power reactor should be cost effective compared to current power generation plant, passively safe, and proliferation-resistant. High-temperature reactor systems allow higher electrical generating efficiencies and high-temperature process heat applications, such as thermo-chemical hydrogen production. The study focused on three concepts; one using molten salt coolant with a prismatic fuel-element geometry, the other two using high-pressure helium coolant with a prismatic fuel-element geometry and a fuel-pebble element design. Peak operating temperatures, passive-safety, decay heat removal, criticality, burnup, reactivity coefficients, and material issues were analyzed to determine the technical feasibility of each concept

  8. Identifying critical constraints for the maximum loadability of electric power systems - analysis via interior point method

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Luciano Vitoria [Sul-riograndense Federal Institute for Education, Science and Technology (IFSul), Pelotas, RS (Brazil)], E-mail: luciano@pelotas.ifsul.edu.br

    2009-07-01

    This paper presents an overview about the maximum load ability problem and aims to study the main factors that limit this load ability. Specifically this study focuses its attention on determining which electric system buses influence directly on the power demand supply. The proposed approach uses the conventional maximum load ability method modelled by an optimization problem. The solution of this model is performed using the Interior Point methodology. As consequence of this solution method, the Lagrange multipliers are used as parameters that identify the probable 'bottlenecks' in the electric power system. The study also shows the relationship between the Lagrange multipliers and the cost function in the Interior Point optimization interpreted like sensitivity parameters. In order to illustrate the proposed methodology, the approach was applied to an IEEE test system and to assess its performance, a real equivalent electric system from the South- Southeast region of Brazil was simulated. (author)

  9. High-resolution stochastic integrated thermal–electrical domestic demand model

    International Nuclear Information System (INIS)

    McKenna, Eoghan; Thomson, Murray

    2016-01-01

    Highlights: • A major new version of CREST’s demand model is presented. • Simulates electrical and thermal domestic demands at high-resolution. • Integrated structure captures appropriate time-coincidence of variables. • Suitable for low-voltage network and urban energy analyses. • Open-source development in Excel VBA freely available for download. - Abstract: This paper describes the extension of CREST’s existing electrical domestic demand model into an integrated thermal–electrical demand model. The principle novelty of the model is its integrated structure such that the timing of thermal and electrical output variables are appropriately correlated. The model has been developed primarily for low-voltage network analysis and the model’s ability to account for demand diversity is of critical importance for this application. The model, however, can also serve as a basis for modelling domestic energy demands within the broader field of urban energy systems analysis. The new model includes the previously published components associated with electrical demand and generation (appliances, lighting, and photovoltaics) and integrates these with an updated occupancy model, a solar thermal collector model, and new thermal models including a low-order building thermal model, domestic hot water consumption, thermostat and timer controls and gas boilers. The paper reviews the state-of-the-art in high-resolution domestic demand modelling, describes the model, and compares its output with three independent validation datasets. The integrated model remains an open-source development in Excel VBA and is freely available to download for users to configure and extend, or to incorporate into other models.

  10. Mobile Learning Based Worked Example in Electric Circuit (WEIEC) Application to Improve the High School Students' Electric Circuits Interpretation Ability

    Science.gov (United States)

    Yadiannur, Mitra; Supahar

    2017-01-01

    This research aims to determine the feasibility and effectivity of mobile learning based Worked Example in Electric Circuits (WEIEC) application in improving the high school students' electric circuits interpretation ability on Direct Current Circuits materials. The research method used was a combination of Four-D Models and ADDIE model. The…

  11. Chemical Dynamics and Critical Phenomena: Electrical Conductivity and Reactivity of Benzyl Bromide in Triethylamine+Water Near its Consolute Point

    Science.gov (United States)

    Specker, Christopher D.; Ellis, Joel M.; Baird, James K.

    2007-06-01

    The binary liquid mixture of triethylamine+water has a lower consolute point at a critical composition of 32.27mass% triethylamine. Starting at a temperature within the one-phase region, the electrical conductivity of a sample of this mixture was measured and found to increase smoothly with increasing temperature before falling sharply at 291.24K (18.09°C). Since opalescence was visible at this temperature, it was identified with the critical solution temperature of the binary mixture. A solution of 90 μL of benzyl bromide dissolved in 90mL of 32.27mass% triethylamine+water was prepared, and the resulting Menschutkin reaction between benzyl bromide and triethylamine was allowed to come to equilibrium. The electrical conductivity of this equilibrium mixture was measured in the one-phase region and was found to increase smoothly with increasing temperature before rising sharply at 291.55K (18.40°C). This temperature was identified as the critical temperature of the ternary. The rate of approach of the ternary mixture to chemical equilibrium was also measured and shown to be governed by a first-order rate law. The temperature dependence of the rate coefficient followed the Arrhenius equation up to a temperature of about 290.74K (17.59°C). Above this temperature, the rate coefficient fell by as much as 22% below the value predicted by extrapolation of the Arrhenius equation. This suppression in the rate reaction in the vicinity of the critical temperature can be interpreted as evidence for the existence of critical slowing down.

  12. Universal Critical Dynamics in High Resolution Neuronal Avalanche Data

    Science.gov (United States)

    Friedman, Nir; Ito, Shinya; Brinkman, Braden A. W.; Shimono, Masanori; DeVille, R. E. Lee; Dahmen, Karin A.; Beggs, John M.; Butler, Thomas C.

    2012-05-01

    The tasks of neural computation are remarkably diverse. To function optimally, neuronal networks have been hypothesized to operate near a nonequilibrium critical point. However, experimental evidence for critical dynamics has been inconclusive. Here, we show that the dynamics of cultured cortical networks are critical. We analyze neuronal network data collected at the individual neuron level using the framework of nonequilibrium phase transitions. Among the most striking predictions confirmed is that the mean temporal profiles of avalanches of widely varying durations are quantitatively described by a single universal scaling function. We also show that the data have three additional features predicted by critical phenomena: approximate power law distributions of avalanche sizes and durations, samples in subcritical and supercritical phases, and scaling laws between anomalous exponents.

  13. Critical transport current in granular high temperature superconductors

    International Nuclear Information System (INIS)

    Bogolyubov, N.A.

    1999-01-01

    The temperature and size dependence of the critical current in a zero magnetic field of three bismuth-based ceramic samples with round cross section and one sample with rectangular triangle cross section have been studied by a contactless technique. It is shown that the critical current can be presented as a product of the temperature and size dependent factors. The temperature-dependent multiplier reflects the individual peculiarities of the Josephson net of each sample, while the size factor is a homogeneous function of the cross-section sizes. The index of this function is independent of the cross-section form, the temperature and individual properties of HTSC samples. The radial distribution of critical current density in round samples and dependence of the critical current density on the magnetic conduction in granular HTSC have been found from the analysis of experimental data

  14. Electrical and mechanical properties of highly elongated high density polyethylene as cryogenic insulation materials

    International Nuclear Information System (INIS)

    Yoshino, Katsumi; Park, Dae-Hee; Miyata, Kiyomi; Yamaoka, Hitoshi; Itoh, Minoru; Ichihara, Syouji.

    1989-01-01

    Electrical and mechanical properties of highly elongated high density polyethylene were investigated in the temperature range between 4.2 K and 400 K from a viewpoint of electrical insulation at low temperature and the following properties have been clarified. (1) The electrical conductivity of samples decreases with increasing draw ratio, and also decreases at cryogenic temperature. (2) Breakdown strength of highly elongated sample is similar to that of non-elongated sample. It is nearby temperature independent below 300 K but at higher temperature it falls steeply. (3) Mechanical breakdown stress and elastic modulus of high density polyethylene increase with increasing draw ratio. Their values at liquid nitrogen temperature are much higher than that at room temperature. On the other hand, strains decreases at liquid nitrogen temperature. (4) Break of the sample develops in the direction of 45deg from the direction of stress both at room temperature and at cryogenic temperature. (5) The characteristic of mechanical breakdown at liquid nitrogen temperature can be explained by a brittleness fracture process. (6) Toughness of high density polyethylene increases with increasing draw ratio until draw ratio of 5, and it decreased, and increase at higher draw ratio. However at extremely high draw ratio of 10 it again increases. These findings clearly indicate that highly elongated high density polyethylene has good electrical and mechanical properties at cryogenic temperature and can be used as the insulating materials at cryogenic temperature. (author)

  15. Critical Chemistry Education in a Private, Suburban High School

    Science.gov (United States)

    Ashby, Patrick; Mensah, Felicia Moore

    2018-01-01

    This critical ethnography documents how a group of 25 students and their teacher/researcher in a suburban, private school setting, the vast majority from the dominant cultural background, engaged with and enacted a critical chemistry education together. Critical chemistry education contextualizes chemistry in socially relevant issues and problematizes participants' conceptual frameworks for understanding the intersections between chemistry and our capitalist society by identifying the shortcomings of traditional scientific language to sufficiently interrogate privilege and oppression. Qualitative data from teacher/researcher field notes and journal, classroom video transcripts, questionnaires, focus group interviews, and student artifacts document that while it is difficult for the teacher/researcher and the students of this setting to reflect upon their own positions of privilege, together they interpreted and made meaning of their experience by (1) developing the ability to critically analyze the products of science for the potential of oppression, (2) developing an understanding of inequity in science, and (3) evaluating and respecting diverse knowledge bases. Based on the findings, we suggest students should be encouraged to problematize socially situated science issues related to settings close to their own communities, students should participate in structured and purposeful journaling to improve their metacognition and critical reflexivity, and critical pedagogues must be explicit with students in their Marxist-based interpretation of the global capitalist super structure.

  16. Geological survey by high resolution electrical survey on granite areas

    International Nuclear Information System (INIS)

    Sugimoto, Yoshihiro; Yamada, Naoyuki

    2002-03-01

    As an Integral part of the geological survey in 'The study of the regions ground water flow system' that we are carrying out with Tono Geoscience Center, we proved the relation between the uncontinuation structure such as lineament in the base rock and resistivity structure (resistivity distribution), for the purpose of that confirms the efficacy of the high resolution electrical survey as geological survey, we carried out high resolution electrical survey on granite area. We obtained the following result, by the comparison of resistivity distribution with established geological survey, lineament analysis and investigative drilling. 1. The resistivity structure of this survey area is almost able to classify it into the following four range. 1) the low resistivity range of 50-800 Ωm, 2) The resistivity range like the middle of 200-2000 Ωm, 3) The high resistivity range of 2000 Ωm over, 4) The low resistivity range of depth of the survey line 400-550 section. 2. The low resistivity range of 4) that correspond with the established geological data is not admitted. 3. It was confirmed that resistivity structure almost correspond to geological structure by the comparison with the established data. 4. The small-scale low resistivity area is admitted in the point equivalent to the lineament position of established. 5. We carried out it with the simulation method about the low resistivity range of 4). As a result, it understood that it has the possibility that the narrow ratio low resistivity area is shown as the wide ratio resistivity range in the analysis section. In the survey in this time, it is conceivable that the resistivity distribution with the possibility of the unhomogeneous and uncontinuation structure of the base rock is being shown conspicuously, the efficacy of the high resolution resistivity survey as geological survey on granite was shown. (author)

  17. A critical look at residential electricity conservation campaigns in a developing country environment

    International Nuclear Information System (INIS)

    Martino Jannuzzi, G. de; Ferreira Santos, V. dos

    1993-01-01

    This paper analyse survey results of the effectiveness of information campaigns to promote energy efficiency among residential consumers in Brazil. The survey found that consumers have a relatively good knowledge of conservation measures to improve electricity usage. Nevertheless, other approaches are needed to promote energy conservation in the household sector. (author). 3 refs, 4 figs, 2 tabs

  18. Seasonal dependence of high-latitude electric fields

    International Nuclear Information System (INIS)

    de la Beaujardiere, O.; Leger, C.; Alcayde, D.; Fontanari, J.

    1991-01-01

    The seasonal dependence of the high-latitude electric field was investigated using Sondrestrom incoherent scatter radar data. Average ExB drifts were derived from 5 years of measurements centered around solar minimum. The electrostatic potentials that best fit the observed average electric field were calculated. It was found that the large-scale convection pattern significantly changes with season. This change involves the overall shape of the convection pattern, as well as the electric field intensity, and thus the total dawn-dusk potential across the polar cap. The cross polar cap potential drop is largest in fall, followed by winter, spring and summer. The small difference found between the summer and winter cross polar cap potential can be attributed to differing field-aligned potential drops. In view of the well-known relationship between field-aligned currents and parallel potential drop, this is consistent with the observations that Birkeland currents are larger in the summer than in winter. Changes in the overall shape of the convection pattern are consistent with the simple notion that the whole pattern is shifted toward the nightside as well as, to a lesser extent, toward the dawnside in summer as compared to winter. This assumption is based on the following observed effects: (1) The rotation of the overall convection pattern toward earlier local times with respect to the noon-midnight direction is maximum for summer on the dayside. (2) On the nightside, the Harang discontinuity is typically located within the radar field of view (Λ=67 to 82) in the winter averaged patterns, but it is equatorward of the field of view in summer. (3) The line that joins the dawn and dusk potential maxima is shifted toward the midnight sector in summer as compared to winter by about 5 degree. (4) In the dawn cell, the latitude of the convection reversal is the lowest during summer; in the dusk cell the latitude of the reversal is the lowest during winter

  19. A critical analysis of the Spanish electrical system: risks and opportunities by 2050

    Directory of Open Access Journals (Sweden)

    Andrés Feijóo

    2015-01-01

    Full Text Available The Spanish electrical system is now in a position to take advantage of developments from the recent past. Many of its facilities, such as nuclear and coal power stations, have a useful life which will come to an end during the 2020-2030 decade [1] (from 2021 in the case of Vandellós 2, and up to 2028 in the case of Santa María de Garoña. The mankind is currently going through a global environmental crisis which includes greenhouse effect gas emissions as a major component [2]. These are closely linked to the energy system, particularly to electricity generation, and could be a determining factor in the future evolution of such a system. Clearly, such a crisis can potentially lead to serious difficulties in accessing energy for many people. The energy business sector has been undoing its ties to particular territories and has been expanding towards other countries to become more and more dependent on foreign capitals and decision-makers. Now that a stagnant period for electricity demand is being experienced, this does not favor new schemes. However, new proposals should be considered given that many infrastructures will soon be obsolete. In this paper some scenarios are proposed to contemplate the transition of the Spanish electrical system towards an energy model with the year 2050 in mind, where the goal is to lower greenhouse gas emissions [3]. One of the factors to be considered during this period should be the participation of renewable energies. Transport and mobility are also likely to undergo some changes, for similar reasons, and in this time frame they will increasingly be designed to use electricity.

  20. Approach to Achieve High Availability in Critical Infrastructure

    Science.gov (United States)

    2015-09-01

    Quantity KPI Key Performance Indicator LORA Level of Repair Analysis M&E Mechanical and Electrical MAC Multiple Award Contracts MTBF Mean Time...determining the scope of work to the contractors. However, effort should be transferred in the performance of audit and KPI monitoring. 2. Forms of

  1. Novel control algorithm of braking energy regeneration system for an electric vehicle during safety–critical driving maneuvers

    International Nuclear Information System (INIS)

    Lv, Chen; Zhang, Junzhi; Li, Yutong; Yuan, Ye

    2015-01-01

    Highlights: • Models of an electric vehicle with regenerative braking system (RBS) are built. • Control algorithm of RBS under safety–critical driving maneuvers is proposed. • Simulations and HIL tests of the proposed strategy are conducted. • Performance improvement of vehicle’s mean deceleration is up to 13.89%. • Test results verify the feasibility and effectiveness of the proposed method. - Abstract: This paper mainly focuses on control algorithm of the braking energy regeneration system of an electric bus under safety–critical driving situations. With the aims of guaranteeing vehicle stability in various types of tyre–road adhesion conditions, based on the characteristics of electrified powertrain, a novel control algorithm of regenerative braking system is proposed for electric vehicles during anti-lock braking procedures. First, the models of vehicle dynamics and main components including braking energy regenerative system of the case-study electric bus are built in MATLAB/Simulink. Then, based on the phase-plane method, the optimal brake torque is calculated for ABS control of vehicle. Next, a novel allocation strategy, wherein the target optimal brake torque is divided into two parts that are handled separately by the regenerative and friction brakes, is developed. Simulations of the proposed control strategy are conducted based on system models built using MATLAB/Simulink. The simulation results demonstrate that the developed strategy enables improved control in terms of vehicle stability and braking performance under different emergency driving conditions. To further verify the synthesized control algorithm, hardware-in-the-loop tests are also performed. The experimental results validate the simulation data and verify the feasibility and effectiveness of the developed control algorithm.

  2. Electrical and hydrodynamic characterization of a high current pulsed arc

    International Nuclear Information System (INIS)

    Sousa Martins, R; Chemartin, L; Zaepffel, C; Lalande, Ph; Soufiani, A

    2016-01-01

    High current pulsed arcs are of significant industrial interest and, aiming to reduce time and cost, there is progressively more and more need for computation tools that describe and predict the behaviour of these arcs. These simulation codes need inputs and validations by experimental databases, but accurate data is missing for this category of electric discharges. The principal lack of understanding is with respect to the transient phase of the current, which can reach thousands of amperes in a few microseconds. In this paper, we present the work realized on an experimental setup that simulates in the laboratory an arc column subjected to five levels of high pulsed current, ranging from 10 kA to 100 kA, with the last one corresponding to the standard lightning current waveform used in aircraft certification processes. This device was instrumented by high speed video cameras to assess the characteristic sizes of the arc channel and to characterize the shock wave generated by the arc expansion. The arc channel radius was measured over time during the axisymmetric phase and reached 3.2 cm. The position and velocity of the shock wave was determined during the first 140 μs. The background-oriented schlieren method was used to study the shock wave and a model for the light deflection inside the shock wave was developed. The mass density profile of the shock wave was estimated and showed good agreement with Rankine–Hugoniot relations at the wave front. Electrical measurements were also used to estimate the time-dependent resistance and conductivity of the arc for times lasting up to 50 μs. (paper)

  3. Electrical and hydrodynamic characterization of a high current pulsed arc

    Science.gov (United States)

    Sousa Martins, R.; Chemartin, L.; Zaepffel, C.; Lalande, Ph; Soufiani, A.

    2016-05-01

    High current pulsed arcs are of significant industrial interest and, aiming to reduce time and cost, there is progressively more and more need for computation tools that describe and predict the behaviour of these arcs. These simulation codes need inputs and validations by experimental databases, but accurate data is missing for this category of electric discharges. The principal lack of understanding is with respect to the transient phase of the current, which can reach thousands of amperes in a few microseconds. In this paper, we present the work realized on an experimental setup that simulates in the laboratory an arc column subjected to five levels of high pulsed current, ranging from 10 kA to 100 kA, with the last one corresponding to the standard lightning current waveform used in aircraft certification processes. This device was instrumented by high speed video cameras to assess the characteristic sizes of the arc channel and to characterize the shock wave generated by the arc expansion. The arc channel radius was measured over time during the axisymmetric phase and reached 3.2 cm. The position and velocity of the shock wave was determined during the first 140 μs. The background-oriented schlieren method was used to study the shock wave and a model for the light deflection inside the shock wave was developed. The mass density profile of the shock wave was estimated and showed good agreement with Rankine-Hugoniot relations at the wave front. Electrical measurements were also used to estimate the time-dependent resistance and conductivity of the arc for times lasting up to 50 μs.

  4. Critical Trajectories for the Human Settlement of the High Frontier

    Science.gov (United States)

    Valentine, Lee S.

    2007-02-01

    If preservation and prosperity of humanity on the Earth and human settlement of space are our goals, we should concentrate on a commercial path to get there. Commercial enterprise has a long history of fortuitously aiding scientific progress. We expect radical changes in the cost of earth to orbit transportation, and in the methods and efficacy of deep space transportation, within the next two decades. A successful space tourism industry, beginning with suborbital tourism, will greatly drive down the cost of access to orbit over the next 15 years. Inexpensive transportation to low Earth orbit is the first requirement for a great future on the High Frontier. Inexpensive means the cost associated with a mature transportation system. A mature system has a cost of three to five times the cost of the propellant. The first cheap, reliable and highly reusable rocket engines are just now appearing in vehicles. With an assured market and high flight rate, the heretofore glacial progress in reducing the cost of space transportation is likely to become rapid. This is the first critical enabling example of synergy between free market economics and scientific and technical progress in space. It will not be the last. New high power switches and ultracapacitors developed for the automotive market make possible cheap, robust and reliable mass driver engines. In space construction, using masses of nonterrestrial materials make the gravity tractor technique much more capable than previous schemes to maneuver asteroids. Ion propulsion will continue to improve and the first solar sails will be flown. Advanced robotics will allow remarkable improvements in productivity. The computing power available to robots began to follow the exponential Moore's law less than decade ago. The first commercial autonomous mobile robots appeared in late summer 2006. Humans, however, will be required for the foreseeable future in repair and supervisory roles, particularly in unstructured settings such as

  5. Electricity

    CERN Document Server

    Basford, Leslie

    2013-01-01

    Electricity Made Simple covers the fundamental principles underlying every aspect of electricity. The book discusses current; resistance including its measurement, Kirchhoff's laws, and resistors; electroheat, electromagnetics and electrochemistry; and the motor and generator effects of electromagnetic forces. The text also describes alternating current, circuits and inductors, alternating current circuits, and a.c. generators and motors. Other methods of generating electromagnetic forces are also considered. The book is useful for electrical engineering students.

  6. A critical look at 25 years of liberalisation of electricity markets in Europe

    International Nuclear Information System (INIS)

    Audigier, Pierre

    2015-01-01

    The movement to liberalise electricity markets was started in the United Kingdom a quarter of a century ago. A few years later, Germany chose to give priority to renewable energies at the expense of nuclear power. France is banking on renewables, while restraining the role of nuclear power. It has to be recognised that liberalisation, as championed by the European Union, has not produced the desired effects for consumers. (author)

  7. Critical examination of RHIC paradigms - mostly high pT

    International Nuclear Information System (INIS)

    Tannenbaum, M.I.

    2009-01-01

    A critical examination of RHIC paradigms is presented. Topics include: search for a critical point with a low energy scan; the lack of understanding of radiative processes in a medium in QCD compared in detail to examples from QED; the reason why some physicists started to measure particles at large p T in the 1960's; a review of the discovery of hard-scattering in p-p collisions in the 1970's via single-inclusive and two-particle correlations and application of these techniques at RHIC. Several paradigms in both soft and hard physics which are popular at RHIC are discussed and challenged.

  8. Xenon Acquisition Strategies for High-Power Electric Propulsion NASA Missions

    Science.gov (United States)

    Herman, Daniel A.; Unfried, Kenneth G.

    2015-01-01

    Solar electric propulsion (SEP) has been used for station-keeping of geostationary communications satellites since the 1980s. Solar electric propulsion has also benefitted from success on NASA Science Missions such as Deep Space One and Dawn. The xenon propellant loads for these applications have been in the 100s of kilograms range. Recent studies performed for NASA's Human Exploration and Operations Mission Directorate (HEOMD) have demonstrated that SEP is critically enabling for both near-term and future exploration architectures. The high payoff for both human and science exploration missions and technology investment from NASA's Space Technology Mission Directorate (STMD) are providing the necessary convergence and impetus for a 30-kilowatt-class SEP mission. Multiple 30-50- kilowatt Solar Electric Propulsion Technology Demonstration Mission (SEP TDM) concepts have been developed based on the maturing electric propulsion and solar array technologies by STMD with recent efforts focusing on an Asteroid Redirect Robotic Mission (ARRM). Xenon is the optimal propellant for the existing state-of-the-art electric propulsion systems considering efficiency, storability, and contamination potential. NASA mission concepts developed and those proposed by contracted efforts for the 30-kilowatt-class demonstration have a range of xenon propellant loads from 100s of kilograms up to 10,000 kilograms. This paper examines the status of the xenon industry worldwide, including historical xenon supply and pricing. The paper will provide updated information on the xenon market relative to previous papers that discussed xenon production relative to NASA mission needs. The paper will discuss the various approaches for acquiring on the order of 10 metric tons of xenon propellant to support potential near-term NASA missions. Finally, the paper will discuss acquisitions strategies for larger NASA missions requiring 100s of metric tons of xenon will be discussed.

  9. Automatic Calibration of High Density Electric Muscle Stimulation

    DEFF Research Database (Denmark)

    Knibbe, Jarrod; Strohmeier, Paul; Boring, Sebastian

    2017-01-01

    . (2) EMS requires time consuming, expert calibration -- confining these interaction techniques to the lab. EMS arrays have been shown to increase stimulation resolution, but as calibration complexity increases exponentially as more electrodes are used, we require heuristics or automated procedures......Electric muscle stimulation (EMS) can enable mobile force feedback, support pedestrian navigation, or confer object affordances. To date, however, EMS is limited by two interlinked problems. (1) EMS is low resolution -- achieving only coarse movements and constraining opportunities for exploration...... for successful calibration. We explore the feasibility of using electromyography (EMG) to auto-calibrate high density EMS arrays. We determine regions of muscle activity during human-performed gestures, to inform stimulation patterns for EMS-performed gestures. We report on a study which shows that auto...

  10. High-precision thermal and electrical characterization of thermoelectric modules

    Science.gov (United States)

    Kolodner, Paul

    2014-05-01

    This paper describes an apparatus for performing high-precision electrical and thermal characterization of thermoelectric modules (TEMs). The apparatus is calibrated for operation between 20 °C and 80 °C and is normally used for measurements of heat currents in the range 0-10 W. Precision thermometry based on miniature thermistor probes enables an absolute temperature accuracy of better than 0.010 °C. The use of vacuum isolation, thermal guarding, and radiation shielding, augmented by a careful accounting of stray heat leaks and uncertainties, allows the heat current through the TEM under test to be determined with a precision of a few mW. The fractional precision of all measured parameters is approximately 0.1%.

  11. Risk assessment of electric generation systems with high wind penetration

    International Nuclear Information System (INIS)

    Salgado Duarte, Yorlandys; Castillo Serpa, Alfredo M. del

    2017-01-01

    The research evaluates the risk function of an Electric Generation System (SGE) with high wind power penetration using the Sequential Monte Carlo Simulation (SMCS) method, which allows calculating indicators that characterize the performance of the SGE with expected average values. The research uses a Markov model of two states or four states according to the characteristics of the generator to simulate the instantaneous capacity. The primary sources of each conventional generator are assumed to be always available; however, wind power depends on the wind behavior in each analyzed region. In this research, the Chronological Series and Weibull models are used to model the wind behavior, and the analyzes are performed in the IEEE-RTS system. The work shows that the behavior of the probabilistic indicators used to analyze the static capacity of the SGE is determined by the model used to simulate the stochastic of the generators and by the primary energy source. (author)

  12. Electric conductivity of alkali metal vapors in the region of critical point

    International Nuclear Information System (INIS)

    Likal'ter, A.A.

    1982-01-01

    A behaviour of alkali metal conductivity in the vicinity of a critical point has been analyzed on the base of deVeloped representations on a vapor state. A phenomenological conductivity theory has been developed, which is in a good agreement with experimental data obtained

  13. Critical Success Factors in a High School Healthcare Education Program

    Science.gov (United States)

    Thessin, Rebecca A.; Scully-Russ, Ellen; Lieberman, Daina S.

    2017-01-01

    Research has demonstrated career and technical education (CTE) programs have a strong positive influence on secondary students' behavior, attendance, academic achievement, and college persistence. Critical success factors common to career academies, small schools, and CTE programs include socio-emotional support and community, along with a culture…

  14. Application of a Gradient Descent Continuous Actor-Critic Algorithm for Double-Side Day-Ahead Electricity Market Modeling

    Directory of Open Access Journals (Sweden)

    Huiru Zhao

    2016-09-01

    Full Text Available An important goal of China’s electric power system reform is to create a double-side day-ahead wholesale electricity market in the future, where the suppliers (represented by GenCOs and demanders (represented by DisCOs compete simultaneously with each other in one market. Therefore, modeling and simulating the dynamic bidding process and the equilibrium in the double-side day-ahead electricity market scientifically is not only important to some developed countries, but also to China to provide a bidding decision-making tool to help GenCOs and DisCOs obtain more profits in market competition. Meanwhile, it can also provide an economic analysis tool to help government officials design the proper market mechanisms and policies. The traditional dynamic game model and table-based reinforcement learning algorithm have already been employed in the day-ahead electricity market modeling. However, those models are based on some assumptions, such as taking the probability distribution function of market clearing price (MCP and each rival’s bidding strategy as common knowledge (in dynamic game market models, and assuming the discrete state and action sets of every agent (in table-based reinforcement learning market models, which are no longer applicable in a realistic situation. In this paper, a modified reinforcement learning method, called gradient descent continuous Actor-Critic (GDCAC algorithm was employed in the double-side day-ahead electricity market modeling and simulation. This algorithm can not only get rid of the abovementioned unrealistic assumptions, but also cope with the Markov decision-making process with continuous state and action sets just like the real electricity market. Meanwhile, the time complexity of our proposed model is only O(n. The simulation result of employing the proposed model in the double-side day-ahead electricity market shows the superiority of our approach in terms of participant’s profit or social welfare

  15. A critical assessment of the Hong Kong Government's proposed post-2008 regulatory regime for local electricity utilities

    International Nuclear Information System (INIS)

    Woo, Chi-Keung; Horowitz, Ira; Tishler, Asher

    2006-01-01

    In December 2005, the Hong Kong Government issued a 'Consultation Paper on Future Development of the Electricity Markets in Hong Kong: Stage II Consultation,' proposing a post-2008 regulatory regime upon the expiration of the existing regulatory contract between the Hong Kong Government and each of the two local electricity utilities. We assess the proposal using the criteria of safe, reliable, and environmentally friendly service at the lowest rates that will allow the utilities reasonable returns on their investments. We caution that if fully adopted, the highly risky proposal may lead to less-reliable service without the compensating benefits to the environment

  16. Exceptionally High Electric Double Layer Capacitances of Oligomeric Ionic Liquids.

    Science.gov (United States)

    Matsumoto, Michio; Shimizu, Sunao; Sotoike, Rina; Watanabe, Masayoshi; Iwasa, Yoshihiro; Itoh, Yoshimitsu; Aida, Takuzo

    2017-11-15

    Electric double layer (EDL) capacitors are promising as next-generation energy accumulators if their capacitances and operation voltages are both high. However, only few electrolytes can simultaneously fulfill these two requisites. Here we report that an oligomeric ionic liquid such as IL4 TFSI with four imidazolium ion units in its structure provides a wide electrochemical window of ∼5.0 V, similar to monomeric ionic liquids. Furthermore, electrochemical impedance measurements using Au working electrodes demonstrated that IL4 TFSI exhibits an exceptionally high EDL capacitance of ∼66 μF/cm 2 , which is ∼6 times as high as those of monomeric ionic liquids so far reported. We also found that an EDL-based field effect transistor (FET) using IL4 TFSI as a gate dielectric material and SrTiO 3 as a channel material displays a very sharp transfer curve with an enhanced carrier accumulation capability of ∼64 μF/cm 2 , as determined by Hall-effect measurements.

  17. An Empirical Study of Critical Soft Factors for Quality Improvement in The Electrical and Electronics Firms in Malaysia

    Directory of Open Access Journals (Sweden)

    Muhammad Madi Abdullah

    2009-03-01

    Full Text Available Soft factors are important aspect that sustains the organizations in their efforts towards continuous quality improvement (QI and customer satisfaction. The conventional wisdom states that quality improvement in organizations increases profits and productivity. Therefore, the aim of the paper is to examine the influence of critical soft factors (CSF on quality improvement (QI. For that purpose, this study examine: (i the relationship between the CSF and QI and (ii to what extent the six CSF explain QI. The study used survey data from 255 electrical and electronics (E&E firms in Malaysia. The individual managers representing the each firm made the unit of analysis of the study. The finding reveals that QI was significantly influenced by the following soft factors: management commitment, customer focus, employee involvement, training & education, and reward & recognition. Supplier relationship was not a significant predictor of quality improvement. Finally, this study has empirically shown that quality improvement will increase when the organizations emphasize more on soft factors.Keywords: Critical soft factors, quality improvement, Electrical and Electronics firms

  18. Private sector participation in the electricity sector : potential and critical issues

    International Nuclear Information System (INIS)

    Dunsky, I.

    2006-01-01

    This presentation discussed the development of infrastructure in the electricity sector with particular reference to public-private partnerships and project finance. Emerging markets that encourage private-sector investment were presented along with recommendations to negotiate power purchase agreements involving small-scale hydroelectric power; a thermal power plant at Suroit, Quebec; and, wind energy in Quebec's Gaspe Peninsula. Interconnection to the provincial power grid was also reviewed with reference to the risk faced by the promoters of a project in terms of project design, construction, financing, production and maintenance. The risks faced by Hydro-Quebec were also discussed along with risk allocations between the private and public sectors. tabs., figs

  19. The electric theories of J. Clerk Maxwell a historical and critical study

    CERN Document Server

    Duhem, Pierre Maurice Marie

    2015-01-01

    In this volume Pierre Duhem first gives an overview of 19th century electricity and magnetism. Next, he applies his keen historical, philosophical, and physical intuition to critiquing Maxwell's theories, especially his electromagnetic theory of light and the ad hoc introduction of displacement current, which he considers too much a product of the "esprit de géométrie" than the "esprit de finesse," as Pascal calls it. In this book, Duhem is guided by the principle that a theory that offers contradictions, even if the theory is posed by a genius, needs to be analysed and discussed until a c

  20. Critical emission from a high-spin black hole

    Science.gov (United States)

    Lupsasca, Alexandru; Porfyriadis, Achilleas P.; Shi, Yichen

    2018-03-01

    We consider a rapidly spinning black hole surrounded by an equatorial, geometrically thin, slowly accreting disk that is stationary and axisymmetric. We analytically compute the broadening of electromagnetic line emissions from the innermost part of the disk, which resides in the near-horizon region. The result is independent of the disk's surface emissivity and therefore universal. This is an example of critical behavior in astronomy that is potentially observable by current or future telescopes.

  1. Electric heating provides a high level of home comfort - economically

    Energy Technology Data Exchange (ETDEWEB)

    Haapakoski, M.

    1997-11-01

    Research and development at IVO in the area of electric heating boasts a tradition going back almost thirty years. Research aimed at further progress is continuing. IVO and power companies launched the `Electrically heated houses of the century` project four years ago. The first results show that electric heating continues to be very competitive with other heating systems. It is an economical way of heating the home and it also increases the comfort of those living there

  2. Radiation resistant electrical bushing for high pressures and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Zajic, V; Banyr, J

    1980-11-15

    The bushing described is characterized by a hollow with a joining member provided inside of at least one of the bushing's electrically conductive core soldered or embedded into a bore in the insulator. Thus, the concentration is limited of the material of the electrically conductive core in the area of the soldered or embedded joint of the support of the electrically conductive core and the insulator, and the resulting force effect is reduced of the difference in thermal dilatations of the materials of the electrically conductive core and the insulator.

  3. Radiation resistant electrical bushing for high pressures and temperatures

    International Nuclear Information System (INIS)

    Zajic, V.; Banyr, J.

    1980-01-01

    The bushing described is characterized by a hollow with a joining member provided inside of at least one of the bushing's electrically conductive core soldered or embedded into a bore in the insulator. Thus, the concentration is limited of the material of the electrically conductive core in the area of the soldered or embedded joint of the support of the electrically conductive core and the insulator, and the resulting force effect is reduced of the difference in thermal dilatations of the materials of the electrically conductive core and the insulator. (J.B.)

  4. WARRIOR II, a high performance modular electric robot system

    International Nuclear Information System (INIS)

    Downton, G.C.

    1996-01-01

    A high performance electric robot, WARRIOR, was built for in-reactor welding at the Oldbury nuclear power plant in the United Kingdom in the mid 1980s. WARRIOR II has been developed as a lighter, smaller diameter articulated welding robot which can be deployed on its umbilical down a stand pipe for remote docking with the manipulator system which delivers it to its work site. A key feature of WARRIOR II has been the development of a prototype spherical modular joint. The module provides the drive torque necessary to motivate the robot arm, acts as the joint bearing, has standard mechanical interfaces for the limb sections, accurately measures the joint angle and has cable services running through the centre. It can act either as a bend or rotate joint and the interconnecting limb sections need only to be simple tubular sections. A wide range of manipulator configurations to suit the access constraints of particular problems can be achieved with a set of joint modules and limb sections. A general purpose motion controller has also been developed which is capable of kinematically controlling any configuration of WARRIOR II thus contributing to the realisation of the concept of a general purpose tool which can be used over and over again, at short notice, in any situation where a high precision, light weight, versatile manipulator is required. (UK)

  5. Highly Electrically Conducting Glass-Graphene Nanoplatelets Hybrid Coatings.

    Science.gov (United States)

    Garcia, E; Nistal, A; Khalifa, A; Essa, Y; Martín de la Escalera, F; Osendi, M I; Miranzo, P

    2015-08-19

    Hybrid coatings consisting of a heat resistant Y2O3-Al2O3-SiO2 (YAS) glass containing 2.3 wt % of graphene nanoplatelets (GNPs) were developed by flame spraying homogeneous ceramic powders-GNP granules. Around 40% of the GNPs survived the high spraying temperatures and were distributed along the splat-interfaces, forming a percolated network. These YAS-GNP coatings are potentially interesting in thermal protection systems and electromagnetic interference shields for aerospace applications; therefore silicon carbide (SiC) materials at the forefront of those applications were employed as substrates. Whereas the YAS coatings are nonconductive, the YAS-GNP coatings showed in-plane electrical conductivity (∼10(2) S·m(-1)) for which a low percolation limit (below 3.6 vol %) is inferred. Indentation tests revealed the formation of a highly damaged indentation zone showing multiple shear displacements between adjacent splats probably favored by the graphene sheets location. The indentation radial cracks typically found in brittle glass coatings are not detected in the hybrid coatings that are also more compliant.

  6. Criticality safety of high-level tank waste

    International Nuclear Information System (INIS)

    Rogers, C.A.

    1995-01-01

    Radioactive waste containing low concentrations of fissile isotopes is stored in underground storage tanks on the Hanford Site in Washington State. The goal of criticality safety is to ensure that this waste remains subcritical into the indefinite future without supervision. A large ratio of solids to plutonium provides an effective way of ensuring a low plutonium concentration. Since the first waste discharge, a program of audits and appraisals has ensured that operations are conducted according to limits and controls applied to them. In addition, a program of surveillance and characterization maintains watch over waste after discharge

  7. Research on High-efficient Remanufacturing Technologies and Application of Electric Motor

    Science.gov (United States)

    Liu, Ren; Zhao, Yuejin; Yang, Xu; Wang, Gen

    2017-09-01

    The energy conservation of electric motor system is the key of industrial energy conservation. With the implementation and acceleration of electric motor energy efficiency improvement plan, more and more electric motors are knocked out. High-efficient remanufacturing of electric motor refers to improving the efficiency of electric motor and recycling the resources by replacing the winding, iron core and other components of electric motor on the basis of the low-efficient/outdated electric motors, which conforms to China’s policy of circular economy and resource recovery. The remanufacturing of electric motor not only maximizes the use of resources, but also reduces the energy consumption generated by reprocessing of cast iron, silicon steel sheet and other materials in dismantling of electric motor. However, structures and iron core materials used in design and manufacture of electric motors are different, and the degrees of wear of electric motors are also different under different operating conditions, which further result in diversified design schemes, increased remanufacturing cost and reduced remanufacturing efficiency. This paper analyzes the key process technologies for remanufacturing of electric motors are researched by analyzing the remanufacturing technologies of electric motors, and presents the feasibility to replace the cast-aluminum rotor with cast-copper rotor in high-efficient remanufacturing process of electric motor.

  8. High Voltage Hybrid Electric Propulsion - Multilayered Functional Insulation System (MFIS) NASA-GRC

    Science.gov (United States)

    Lizcano, M.

    2017-01-01

    High power transmission cables pose a key challenge in future Hybrid Electric Propulsion Aircraft. The challenge arises in developing safe transmission lines that can withstand the unique environment found in aircraft while providing megawatts of power. High voltage AC, variable frequency cables do not currently exist and present particular electrical insulation challenges since electrical arcing and high heating are more prevalent at higher voltages and frequencies. Identifying and developing materials that maintain their dielectric properties at high voltage and frequencies is crucial.

  9. Consideration of Nuclear Criticality When Directly Disposing Highly Enriched Spent Nuclear Fuel in Unsaturated Tuff - I: Nuclear Criticality Constraints

    International Nuclear Information System (INIS)

    Rechard, Rob P.; Sanchez, Lawrence C.; Trellue, Holly R.

    2003-01-01

    This paper presents the mass, concentration, and volume required for a critical event to occur in homogeneous mixtures of fissile material and various other geologic materials. The fissile material considered is primarily highly enriched uranium spent fuel; however, 239 Pu is considered in some cases. The non-fissile materials examined are those found in the proposed repository area at Yucca Mountain, Nevada: volcanic tuff, iron rust, concrete, and naturally occurring water. For 235 U, the minimum critical solid concentration for tuff was 5 kg/m 3 (similar to sandstone), and in goethite, 45 kg/m 3 . The critical mass of uranium was sensitive to a number of factors, such as moisture content and fissile enrichment, but had a minimum, assuming almost 100% saturation and >20% enrichment, of 18 kg in tuff as Soddyite (or 9.5 kg as UO 2 ) and 7 kg in goethite. For 239 Pu, the minimum critical solid concentration for tuff was 3 kg/m 3 (similar to sandstone); in goethite, 20 kg/m 3 . The critical mass of plutonium was also sensitive to a number of factors, but had a minimum, assuming 100% saturation and 80-90% enrichment, of 5 kg in tuff and 6 kg in goethite

  10. Electric utilities and public criticism. Answers and questions from the fields of politics, market and environment

    International Nuclear Information System (INIS)

    Fulda, E.

    1994-01-01

    Renowned practicians and theoreticians engaged in the power economy and energy politics get to grips with the critical issues in this branch of industry such as the deregularisation of the markets; new concepts for companies and politics; altered framework conditions for power companies; and innovations in the power economy. The contributions and discussions point out ways and perspectives for adapting to the new market situation and new framework conditions governing the whole energy sector. The ideas, initiatives and experiences they present stood in the focus of the interdisciplinary exchange of views that took place at the Wissenschaftszentrum in Bonn/Bad Godesberg during the annual meeting of the Gesellschaft fuer Energiewissenschaft und Energiepolitik e.V. (GEE) from 7 to 8 June 1993. (orig.) [de

  11. Experimental Study on High Electrical Breakdown of Water Dielectric

    International Nuclear Information System (INIS)

    Zhang Zicheng; Zhang Jiande; Yang Jianhua

    2005-01-01

    By means of a coaxial apparatus, pressurized water breakdown experiments with microsecond charging have been carried out with different surface roughness of electrodes and different ethylene glycol concentrations of ethylene glycol/water mixture. The experimental results about the breakdown stress and the effective time are presented. The breakdown stress is normalized to the situation that the effective time is transformed to 1 μs and analyzed. The conclusions are as follows: (1) the breakdown stress formula is modified to E = 0.561M A -1/10 t eff -1/N P 1/8 ; (2) the coefficient M is significantly increased by surface polishing and ethylene glycol additive; (3) it is accumulative for the capacity of improving electrical breakdown strength for surface polishing, ethylene glycol additive, and pressurization, of which pressurization is the most effective method; (4) the highest stress of 235.5 kV/cm is observed in ethylene glycol/water mixture with an ethylene glycol concentration of 80% at a hydrostatic pressure of 1215.9 kPa and is about one time greater than that in pure water at constant pressure; (5) for pressurization and surface polishing, the primary mechanism to improve the breakdown strength of water dielectric is the increase in the breakdown time delay. Research results indicate great potential in the application of the high power pulse conditioning system of water dielectric

  12. Study on Earthquake Response of High Voltage Electrical Equipment Coupling System with Flexible Busbar

    Science.gov (United States)

    Liu, Chuncheng; Qu, Da; Wang, Chongyang; Lv, Chunlei; Li, Guoqiang

    2017-12-01

    With the rapid development of technology and society, all walks of life in China are becoming more and more dependent on power systems. When earthquake occurs, the electrical equipment of substation is prone to damage because of its own structural features, top-heavy, and brittleness of main body. At the same time, due to the complex coupling of the soft electrical connection of substation electrical equipment, the negative impact can not be estimated. In this paper, the finite element model of the coupling system of the single unit of high voltage electrical equipment with the connecting soft bus is established and the seismic response is analysed. The results showed that there is a significant difference between the simple analysis for the seismic response of electrical equipment monomer and the analytical results of electrical equipment systems, and the impact on different electrical equipment is different. It lays a foundation for the future development of seismic performance analysis of extra high voltage electrical equipment.

  13. Electric breakdown of high polymer insulating materials at cryogenic temperature

    International Nuclear Information System (INIS)

    Kim, Sanhyon; Yoshino, Katsumi

    1985-01-01

    Cryogenic properties : temperature dependence of E sub(b) and effects of media upon E sub(b) were investigated on several high polymers. Temperature conditions were provided by liquid He (4.2 K), liquid N 2 (77 K) and cryogen (dry ice-methyl alcohol, 194 K). Silicone oil was used also at ambient temperature and elevated temperature. Polymer film coated with gold by vacuum evaporation was placed in cryostat, and high tension from pulse generator was applied to the film. Dielectric breakdowns were detected by oscilloscope and observed visually. The results of experiment are summerized as follow. (1) E sub(b) of film in He is affected by medium remarkably, and covering with 3-methyl pentane is effective for increasing E sub(b). (2) Temperature dependence of E sub(b) was not recognized in cryogenic temperature below liquid N 2 . (3) Temperature characteristic of E sub(b) changes considerably at the critical temperature T sub(c), and T sub(c) is dependent on material. (4) Strength against dielectric breakdown under cryogenic temperature is not affected by bridging caused by irradiation of electron beam. (5) Dielectric breakdown is thought to be caused by electronic process such as electron avalanche. Consequently, for designing insulation for the temperature below liquid He, insulation design for liquid N 2 is thought to be sufficient. However, the degradation and breakdown by mechanical stress under cryogenic temperature must be taken into consideration. (Ishimitsu, A.)

  14. A critical look back over 15 years of the liberalization of the electricity markets

    International Nuclear Information System (INIS)

    Audigier, P.

    2004-01-01

    Various analyses are now available concerning the successes and woes of the policies for the liberalization of the electricity market implemented around the world for some 15 years. The author offers us an overview of these documents, focusing on the results obtained when considered in light of the arguments put forward by those favouring liberalization. The problems observed more recently in the liberalized markets have certainly had local causes. They nevertheless all have several things in common. Their attributes (non-storability, inelasticity of demand, etc.), have made the electron a raw material (commodity) such as the markets are not very efficient. Solutions can always be found, but these solutions, each more ingenious than the last, all have a price. This is particularly the case for the household market segment, with the paradox here being that it is precisely at the very moment when experts are beginning to doubt the value (cost/profit) of extending competition to this market segment that the European Union decides to authorize such an extension. (authors)

  15. Application-specific electrical characterization of high power batteries with lithium titanate anodes for electric vehicles

    International Nuclear Information System (INIS)

    Farmann, Alexander; Waag, Wladislaw; Sauer, Dirk Uwe

    2016-01-01

    This study shows results of extensive experimental measurements performed on high power lithium titanate based batteries. Characterization tests are performed over a wide temperature range (−20 °C – +40 °C) by employing electrochemical impedance spectroscopy and modified hybrid pulse power characterization tests. Furthermore, the behavior of battery impedance parameters over the battery lifetime with regard to temperature, State-of-Charge and their influence on available battery power in an example of electric vehicles is discussed. Based on extracted parameters, a reduced order equivalent circuit model considering the nonlinearity of the charge transfer resistance is parametrized. The obtained results indicate that ohmic resistance increases with decreasing State-of-Charge while the shape of the curve remains almost constant over the battery lifetime. The total impedance determined at 1 mHz shows almost no dependence on State-of-Charge and remains constant over the whole State-of-Charge range. The necessity of considering the impact of the current dependence of the direct current resistance at least at low temperatures (i.e., below 0 °C) is confirmed. Moreover, by investigating the Butler-Volmer equation the behavior of exchange current density and symmetry factor is analyzed for various temperatures and State-of-Charges over the battery lifetime. - Highlights: • Impedance characteristic over the battery lifetime is investigated. • Batteries at different aging states using lithium titanate anodes are investigated. • The influence of temperature on impedance characteristic is investigated. • Butler-Volmer behavior is comprehensively investigated under various conditions.

  16. Stable superconducting magnet. [high current levels below critical temperature

    Science.gov (United States)

    Boom, R. W. (Inventor)

    1967-01-01

    Operation of a superconducting magnet is considered. A method is described for; (1) obtaining a relatively high current in a superconducting magnet positioned in a bath of a gas refrigerant; (2) operating a superconducting magnet at a relatively high current level without training; and (3) operating a superconducting magnet containing a plurality of turns of a niobium zirconium wire at a relatively high current level without training.

  17. Application of high voltage electric field (HVEF) drying technology in potato chips

    International Nuclear Information System (INIS)

    Bai, Yaxiang; Shi, Hua; Yang, Yaxin

    2013-01-01

    In order to improve the drying efficiency and qualities of vegetable by high voltage electric field (HVEF), potato chips as a representative of vegetable was dried using a high voltage electric drying systems at 20°C. The shrinkage rate, water absorption and rehydration ratio of dried potato chips were measured. The results indicated that the drying rate of potato chips was significantly improved in the high voltage electric drying systems. The shrinkage rate of potato chips dried by high voltage electric field was 1.1% lower than that by oven drying method. And the rehydration rate of high voltage electric field was 24.6% higher than that by oven drying method. High voltage electric field drying is very advantageous and can be used as a substitute for traditional drying method.

  18. High intensity pulsed electric field as an innovative technique for extraction of bioactive compounds-A review.

    Science.gov (United States)

    Yan, Liang-Gong; He, Lang; Xi, Jun

    2017-09-02

    How to extract bioactive compounds safely and efficiently is one of the problems for the food and pharmaceutical industry. In recent years, several novel extraction techniques have been proposed. To pursue a more efficient method for industrial production, high intensity pulsed electric field (HIPEF) extraction technique has been developed. HIPEF extraction technique, which is based on the conventional pulsed electric field (PEF), provided higher electric field intensity and a special continuous extraction system, and it has confirmed less extraction time, higher extraction yield, and mild processing temperature. So this innovative technique is promising for application of industrial production. This review was devoted to introducing the recent achievement of HIPEF extraction technique, including novel HIPEF continuous extraction system, principles and mechanisms; the critical process factors influencing its performance applications; and comparison of HIPEF extraction with other extraction techniques. In the end, the defects and future trends of HIPEF extraction were also discussed.

  19. High Throughput Determinations of Critical Dosing Parameters (IVIVE workshop)

    Science.gov (United States)

    High throughput toxicokinetics (HTTK) is an approach that allows for rapid estimations of TK for hundreds of environmental chemicals. HTTK-based reverse dosimetry (i.e, reverse toxicokinetics or RTK) is used in order to convert high throughput in vitro toxicity screening (HTS) da...

  20. Analysis of Electric Vehicle DC High Current Conversion Technology

    Science.gov (United States)

    Yang, Jing; Bai, Jing-fen; Lin, Fan-tao; Lu, Da

    2017-05-01

    Based on the background of electric vehicles, it is elaborated the necessity about electric energy accurate metering of electric vehicle power batteries, and it is analyzed about the charging and discharging characteristics of power batteries. It is needed a DC large current converter to realize accurate calibration of power batteries electric energy metering. Several kinds of measuring methods are analyzed based on shunts and magnetic induction principle in detail. It is put forward power batteries charge and discharge calibration system principle, and it is simulated and analyzed ripple waves containing rate and harmonic waves containing rate of power batteries AC side and DC side. It is put forward suitable DC large current measurement methods of power batteries by comparing different measurement principles and it is looked forward the DC large current measurement techniques.

  1. High-Temperature Switched-Reluctance Electric Motor

    Science.gov (United States)

    Montague, Gerald; Brown, Gerald; Morrison, Carlos; Provenza, Andy; Kascak, Albert; Palazzolo, Alan

    2003-01-01

    An eight-pole radial magnetic bearing has been modified into a switched-reluctance electric motor capable of operating at a speed as high as 8,000 rpm at a temperature as high as 1,000 F (=540 C). The motor (see figure) is an experimental prototype of starter-motor/generator units that have been proposed to be incorporated into advanced gas turbine engines and that could operate without need for lubrication or active cooling. The unique features of this motor are its electromagnet coils and, to some extent, its control software. Heretofore, there has been no commercial-off-the-shelf wire capable of satisfying all of the requirements for fabrication of electromagnet coils capable of operation at temperatures up to 1,000 F (=540 C). The issues addressed in the development of these electromagnet coils included thermal expansion, oxidation, pliability to small bend radii, micro-fretting, dielectric breakdown, tensile strength, potting compound, thermal conduction, and packing factor. For a test, the motor was supported, along with a rotor of 18 lb (.8-kg) mass, 3-in. (.7.6-cm) diameter, 21-in. (.53-cm) length, on bearings packed with high-temperature grease. The motor was located at the mid span of the rotor and wrapped with heaters. The motor stator was instrumented with thermocouples. At the time of reporting the information for this article, the motor had undergone 14 thermal cycles between room temperature and 1,000 F (.540 C) and had accumulated operating time >27.5 hours at 1,000 F (=540 C). The motor-controller hardware includes a personal computer equipped with analog-to-digital input and digital-to-analog output cards. The controller software is a C-language code that implements a switched-reluctance motor-control principle: that is, it causes the coils to be energized in a sequence timed to generate a rotating magnetic flux that creates a torque on a scalloped rotor. The controller can operate in an open- or closed-loop mode. In addition, the software has

  2. Electrical Capacitance Volume Tomography with High-Contrast Dielectrics

    Science.gov (United States)

    Nurge, Mark

    2010-01-01

    The Electrical Capacitance Volume Tomography (ECVT) system has been designed to complement the tools created to sense the presence of water in nonconductive spacecraft materials, by helping to not only find the approximate location of moisture but also its quantity and depth. The ECVT system has been created for use with a new image reconstruction algorithm capable of imaging high-contrast dielectric distributions. Rather than relying solely on mutual capacitance readings as is done in traditional electrical capacitance tomography applications, this method reconstructs high-resolution images using only the self-capacitance measurements. The image reconstruction method assumes that the material under inspection consists of a binary dielectric distribution, with either a high relative dielectric value representing the water or a low dielectric value for the background material. By constraining the unknown dielectric material to one of two values, the inverse math problem that must be solved to generate the image is no longer ill-determined. The image resolution becomes limited only by the accuracy and resolution of the measurement circuitry. Images were reconstructed using this method with both synthetic and real data acquired using an aluminum structure inserted at different positions within the sensing region. The cuboid geometry of the system has two parallel planes of 16 conductors arranged in a 4 4 pattern. The electrode geometry consists of parallel planes of copper conductors, connected through custom-built switch electronics, to a commercially available capacitance to digital converter. The figure shows two 4 4 arrays of electrodes milled from square sections of copper-clad circuit-board material and mounted on two pieces of glass-filled plastic backing, which were cut to approximately square shapes, 10 cm on a side. Each electrode is placed on 2.0-cm centers. The parallel arrays were mounted with the electrode arrays approximately 3 cm apart. The open ends

  3. Microscopic observation of ferroelectric domains in SrTiO3 using birefringence imaging techniques under high electric fields

    International Nuclear Information System (INIS)

    Manaka, Hirotaka; Nozaki, Hirofumi; Miura, Yoko

    2017-01-01

    Phase transitions in SrTiO 3 between quantum paraelectric, coherent paraelectric, and electric-field-induced ferroelectric states are governed by tetragonal domains with quantum fluctuations. However, their characteristics are still unclear. To observe the electric-field-induced ferroelectric state using birefringence imaging techniques, we developed a suitable sample holder to apply high electric fields of up to E ≃ 5 kV/cm and temperatures down to T = 20 K. From birefringence imaging measurements of the ferroelectric LiNbO 3 with varying electric field, distributions of the electric field in the sample stage were found to be negligible. In SrTiO 3 , a huge-retardance area corresponding to the ferroelectric domains appears at E > 2 kV/cm and T ≤ 60 K even though the paraelectric domains partially remain. Furthermore, the fast-axis direction rotates by 90° at the ferroelectric phase transition because of an electrostrictive effect in ferroelectrics. The phase diagram of the critical electric field and temperature agrees with previous reports obtained from dielectric and neutron scattering measurements. (author)

  4. A critical assessment of the different approaches aimed to secure electricity generation supply

    Energy Technology Data Exchange (ETDEWEB)

    Batlle, C.; Rodilla, P. [Technological Research Institute, Pontifical University of Comillas, Sta. Cruz de Marcenado 26, 28015 Madrid (Spain)

    2010-11-15

    Since the very beginning of the power systems reform process, one of the key questions posed has been whether the market, of its own accord, is able to provide satisfactory security of supply at the power generation level or if some additional regulatory mechanism needs to be introduced, and in the latter case, which is the most suitable approach to tackle the problem. This matter is undoubtedly gaining importance and it has taken a key role in the energy regulators' agendas. In this paper, we critically review and categorize the different approaches regulators can opt for to deal with the problem of guaranteeing (or at least enhancing) security of supply in a market-oriented environment. We analyze the most relevant regulatory design elements throughout an updated assessment of the broad range of international experiences, highlighting the lessons we have learned so far in a variety of contexts. Based on the analysis, we conclude by providing a set of principles and criteria that should be considered by the regulator when designing a security of supply mechanism. (author)

  5. A critical assessment of the different approaches aimed to secure electricity generation supply

    International Nuclear Information System (INIS)

    Batlle, C.; Rodilla, P.

    2010-01-01

    Since the very beginning of the power systems reform process, one of the key questions posed has been whether the market, of its own accord, is able to provide satisfactory security of supply at the power generation level or if some additional regulatory mechanism needs to be introduced, and in the latter case, which is the most suitable approach to tackle the problem. This matter is undoubtedly gaining importance and it has taken a key role in the energy regulators' agendas. In this paper, we critically review and categorize the different approaches regulators can opt for to deal with the problem of guaranteeing (or at least enhancing) security of supply in a market-oriented environment. We analyze the most relevant regulatory design elements throughout an updated assessment of the broad range of international experiences, highlighting the lessons we have learned so far in a variety of contexts. Based on the analysis, we conclude by providing a set of principles and criteria that should be considered by the regulator when designing a security of supply mechanism.

  6. Absolute electrical impedance tomography (aEIT) guided ventilation therapy in critical care patients: simulations and future trends.

    Science.gov (United States)

    Denaï, Mouloud A; Mahfouf, Mahdi; Mohamad-Samuri, Suzani; Panoutsos, George; Brown, Brian H; Mills, Gary H

    2010-05-01

    Thoracic electrical impedance tomography (EIT) is a noninvasive, radiation-free monitoring technique whose aim is to reconstruct a cross-sectional image of the internal spatial distribution of conductivity from electrical measurements made by injecting small alternating currents via an electrode array placed on the surface of the thorax. The purpose of this paper is to discuss the fundamentals of EIT and demonstrate the principles of mechanical ventilation, lung recruitment, and EIT imaging on a comprehensive physiological model, which combines a model of respiratory mechanics, a model of the human lung absolute resistivity as a function of air content, and a 2-D finite-element mesh of the thorax to simulate EIT image reconstruction during mechanical ventilation. The overall model gives a good understanding of respiratory physiology and EIT monitoring techniques in mechanically ventilated patients. The model proposed here was able to reproduce consistent images of ventilation distribution in simulated acutely injured and collapsed lung conditions. A new advisory system architecture integrating a previously developed data-driven physiological model for continuous and noninvasive predictions of blood gas parameters with the regional lung function data/information generated from absolute EIT (aEIT) is proposed for monitoring and ventilator therapy management of critical care patients.

  7. Development of high electrical resistance persistent current switch for high speed energization system

    International Nuclear Information System (INIS)

    Jizo, Y.; Furuta, Y.; Nakashima, H.

    1986-01-01

    Japanese National Railways is now developing a superconducting magnetically-levitated train system. A persistent current switch is incorporated in the super-conducting magnet used in the magnetically-levitated train. In recent years, the switch has been required to have higher electrical resistance during its off-state in order to realize the high speed energization/de-energization system of the superconducting magnets. The system aims to decrease evaporation volume of liquid helium during the energization/de-energization of the magnet, by means of energizing the superconducting magnet with high current increasing/decreasing rate. Consequently, it would be possible to decrease the dependence of the on-board magnet system upon the ground cooling system. Through the development of a stable superconductive wire material and a coil structure for the persistent current switch using many small model switches which were produced in order to improve their current carrying capacities, the authors have succeeded in manufacturing the high electrical resistance persistent current switch whose electrical resistance was 5 ohms. The switch, of cylindrical shape, has a diameter of about 100mm, a length of about 100mm. These 5 ohm PCSs are now functioning in stable conditions being incorporated in the superconducting magnets of No.2 vehicle of MLU001 at the JNR's Miyazaki test track. Further, the authors are now developing the PCS of still higher resistance values, such as 50 ohms, through studies for stabilization in structural aspects of the winding and obtaining results therefrom

  8. High critical temperature superconductors: Progress achieved after two years

    International Nuclear Information System (INIS)

    Maillard, J.M.; Rammal, R.; Vittorge, M.C.

    1989-01-01

    Progress concerning the theory of high temperature superconductors and activity of laboratories of the CNRS (France) are reviewed and news on strategy, budgets, theoretical research, materials characterization, fabrication process technology transfers, commercialisation, uses and data bases are given [fr

  9. High critical temperature superconducting composite and fabrication process

    International Nuclear Information System (INIS)

    Dubots, P.; Legat, D.

    1989-01-01

    The core comprises a high temperature superconducting sintered oxide coated with alumina or barium oxide covered with a first sheath in aluminum, a second sheath in niobium and a third sheath in copper [fr

  10. High-Frequency Neuromuscular Electrical Stimulation Increases Anabolic Signaling.

    Science.gov (United States)

    Mettler, Joni A; Magee, Dillon M; Doucet, Barbara M

    2018-03-16

    Neuromuscular electrical stimulation (NMES) is commonly used in rehabilitation settings to increase muscle mass and strength. However, the effects of NMES on muscle growth are not clear and no human studies have compared anabolic signaling between low-frequency (LF-) and high-frequency (HF-) NMES. The purpose of this study was to determine the skeletal muscle anabolic signaling response to an acute bout of LF- and HF-NMES. Eleven young healthy volunteers (6 men; 5 women) received an acute bout of LF- (20 Hz) and HF- (60 Hz) NMES. Muscle biopsies were obtained from the vastus lateralis muscle prior to the first NMES treatment and 30-mins following each NMES treatment. Phosphorylation of the following key anabolic signaling proteins was measured by Western blot and proteins are expressed as a ratio of phosphorylated to total: mammalian target of rapamycin (mTOR), p70-S6 kinase 1 (S6K1), and eukaryotic initiation factor 4E binding protein 1 (4E-BP1). Compared to Pre-NMES, phosphorylation of mTOR was upregulated 40.2% for LF-NMES (P = 0.018) and 68.4% for HF-NMES (P 0.05). There were no differences between treatment conditions for 4E-BP1 phosphorylation (P > 0.05). An acute bout of LF- and HF-NMES upregulated anabolic signaling with HF-NMES producing a greater anabolic response compared to LF-NMES, suggesting that HF-stimulation may provide a stronger stimulus for processes that initiate muscle hypertrophy. Additionally, the stimulation frequency parameter should be considered by clinicians in the design of optimal NMES treatment protocols.

  11. Impacts of High Variable Renewable Energy Futures on Wholesale Electricity Prices, and on Electric-Sector Decision Making

    Energy Technology Data Exchange (ETDEWEB)

    Seel, Joachim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mills, Andrew D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wiser, Ryan H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Deb, Sidart [LCG Consulting, Los Altos, CA (United States); Asokkumar, Aarthi [LCG Consulting, Los Altos, CA (United States); Hassanzadeh, Mohammad [LCG Consulting, Los Altos, CA (United States); Aarabali, Amirsaman [LCG Consulting, Los Altos, CA (United States)

    2018-05-11

    Increasing penetrations of variable renewable energy (VRE) can affect wholesale electricity price patterns and make them meaningfully different from past, traditional price patterns. Many long-lasting decisions for supply- and demand-side electricity infrastructure and programs are based on historical observations or assume a business-as-usual future with low shares of VRE. Our motivating question is whether certain electric-sector decisions that are made based on assumptions reflecting low VRE levels will still achieve their intended objective in a high VRE future. We qualitatively describe how various decisions may change with higher shares of VRE and outline an analytical framework for quantitatively evaluating the impacts of VRE on long-lasting decisions. We then present results from detailed electricity market simulations with capacity expansion and unit commitment models for multiple regions of the U.S. for low and high VRE futures. We find a general decrease in average annual hourly wholesale energy prices with more VRE penetration, increased price volatility and frequency of very low-priced hours, and changing diurnal price patterns. Ancillary service prices rise substantially and peak net-load hours with high capacity value are shifted increasingly into the evening, particularly for high solar futures. While in this report we only highlight qualitatively the possible impact of these altered price patterns on other demand- and supply-side electric sector decisions, the core set of electricity market prices derived here provides a foundation for later planned quantitative evaluations of these decisions in low and high VRE futures.

  12. Non invasive adjustment of fluid status in critically ill patients on renal replacement therapy. Role of Electrical Cardiometry

    Directory of Open Access Journals (Sweden)

    Khaled Hamed Mahmoud

    2016-08-01

    Full Text Available Background: Electrical Cardiometry allows measurement of fluid status using thoracic fluid content (TFC, cardiac output, cardiac index, systemic vascular resistance index which could be ideal noninvasive hemodynamic monitoring for patients undergoing hemodialysis (HD. Objectives: Investigating the relation between changes in TFC and amount of fluid removal during HD session and to monitor hemodynamic parameters to avoid episodes of hemodynamic compromise during HD session. Methods: Thirty critically ill patients on HD were enrolled. Clinical assessment of volume overload and hemodynamics (BP, MAP, CVP, monitored by Electrical Cardiometry ICON® before HD and all through sessions. Results: Out of studied patients males represented 46.7% (n = 14 with mean age 48 ± 16 years. There was positive correlation between UF volume and TFC (r = 0.410, P = 0.025. Out of the 30 pts studied 18 pts (60% were hemodynamically stable vs 12 pts (40% that had hypotension represented by non responders group and had lower TFC compared to the hemodynamically stable group (26.45 kohm−1 vs 37.8 kohm−1 with P value of 0.004 indicating that they were hypovolemic. Out of the 30 pts studied 18 pts (60% weren’t congested vs 12 pts (40% remained persistently congested after accomplishing HD session with significantly higher TFC when compared to those who got rid of congestion (43.14 ± 9.9 kohm−1 vs 25.44 ± 5.5 kohm−1 with P value of 0.0001 indicating that they were still hypervolemic. Using analysis of ROC curve TFC at 25.34 kohm−1 was a significant predictor of hypotension with P value of 0.002, AUC 83.4%, sensitivity 67% and specificity 100%. Also TFC cutoff value predicting persistent congestion was 37.02 kohm−1 with P value of 0.0001, AUC 95.8%, sensitivity 83% and specificity 100%. Conclusion: Electrical Cardiometry is an evolving noninvasive tool for adjusting fluid status of critically ill patient on RRT using thoracic fluid

  13. Electric field analysis of extra high voltage (EHV) underground cables using finite element method

    DEFF Research Database (Denmark)

    Kumar, Mantosh; Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar

    2017-01-01

    used for the insulator due electrical, thermal or environmental stress. Most of these problems are related to the electric field stress on the insulation of the underground cables. The objective of the electric field analysis by using different numerical techniques is to find electric field stress...... electric field stress and other parameters of EHV underground cables with given boundary conditions using 2-D electric field analysis software package (IES-ELECTRO module) which is based on the finite element method (FEM).......Transmission and Distribution of electric power through underground cables is a viable alternative to overhead lines, particularly in residential or highly populated areas. The electrical stresses are consequences of regular voltages and over voltages and the thermal stresses are related to heat...

  14. Potentialities in electronics of new high critical temperature superconductors

    International Nuclear Information System (INIS)

    Hartemann, P.

    1989-01-01

    The main electronic applications of superconductors involve the signal processing, the electromagnetic wave detection and the magnetometry. Characteristics of devices based on conventional superconductors cooled by liquid helium are given and the changes induced by incorporating high-temperature superconductors are estimated. After a survey of new superconductor properties, the superconducting devices for analog or digital signal processing are reviewed. The gains predicted for high-temperature superconducting analog devices are considered in greater detail. Different sections deal with the infrared or (sub)millimeter wave detection. The most sensitive apparatuses for magnetic measurements are based on SQUIDs. Features of SQUIDs made of granular high-temperature superconducting material samples (grain boundaries behave as barriers of intrinsic junctions) are discussed [fr

  15. Electrical conductivity of highly ionized dense hydrogen plasma. 1. Electrical measurements and diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, R; Guenther, K [Akademie der Wissenschaften der DDR, Berlin. Zentralinstitut fuer Elektronenphysik

    1976-05-11

    A diagnostic technique for the determination of pressure, temperature and its radial distribution, the strength of the electric field and the current of a wall-stabilized pulse hydrogen arc at a pressure of 10 atm and a maximum power of 120 kW/cm arc length is developed.

  16. High benefits approach for electrical energy conversion in electric vehicles from DC to PWM-AC without any generated harmonic

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2014-01-01

    Highlights: • Novel hybrid power source including AC feature for using in electric/hybrid vehicles. • Minimizing the energy loss in electric/hybrid vehicles by using the proposed system. • Suitable AC wave form for braking/accelerating purposes in electric/hybrid vehicles. • A novelty is that the harmonic generated by the added AC feature is really zero. • Another novelty is the capability of choosing arbitrary frequency for AC feature. - Abstract: This paper presents a novel hybrid power source, including a Li-ion battery together with an interface, which generates simultaneously electrical energy with the forms of both DC and AC for electric vehicles. A novel and high benefits approach is applied to convert the electrical energy of the Li-ion battery from DC form to single-phase symmetric pulse-width modulation (PWM)-AC form. Harmonic generation is one of the important problems when electrical energy is converted from DC to AC but there are not any generated harmonic during the DC/AC conversion using the proposed technique. The proposed system will be widely used in electric/hybrid vehicles because it has many benefits. Minimizing the energy loss (saving energy), no generated harmonic (it is really zero), the capability of arbitrary/necessary frequency selection for output AC voltage and the ability of long distance energy transmission are some novelties and advantages of the proposed system. The proposed hybrid power source including DC/AC PWM inverter is simulated in Proteus 6 software environment and a laboratory-based prototype of the hybrid power source is constructed to validate the theoretical and simulation results. Simulation and experimental results are presented to prove the superiority of the proposed hybrid power supply

  17. Evidence for intrinsic critical current density in high Tc superconductors

    International Nuclear Information System (INIS)

    Freltoft, T.; Minnhagen, P.; Jeldtoft Jensen, H.

    1991-01-01

    We present measurements of the voltage-current characteristics of high quality epitaxial YBaCuO films in zero magnetic field. According to the predictions of a current induced vortex pair breaking picture the voltage should follow the functional form V∝I(I-I c ) a-1 . An analysis designed to test this functional behavior is carried out. Consistency is found. (orig.)

  18. Variability of electricity load patterns and its effect on demand response: A critical peak pricing experiment on Korean commercial and industrial customers

    International Nuclear Information System (INIS)

    Jang, Dongsik; Eom, Jiyong; Jae Park, Min; Jeung Rho, Jae

    2016-01-01

    To the extent that demand response represents an intentional electricity usage adjustment to price changes or incentive payments, consumers who exhibit more-variable load patterns on normal days may be capable of altering their loads more significantly in response to dynamic pricing plans. This study investigates the variation in the pre-enrollment load patterns of Korean commercial and industrial electricity customers and their impact on event-day loads during a critical peak pricing experiment in the winter of 2013. Contrary to conventional approaches to profiling electricity loads, this study proposes a new clustering technique based on variability indices that collectively represent the potential demand–response resource that these customers would supply. Our analysis reveals that variability in pre-enrollment load patterns does indeed have great predictive power for estimating their impact on demand–response loads. Customers in relatively low-variability clusters provided limited or no response, whereas customers in relatively high-variability clusters consistently presented large load impacts, accounting for most of the program-level peak reductions. This study suggests that dynamic pricing programs themselves may not offer adequate motivation for meaningful adjustments in load patterns, particularly for customers in low-variability clusters. - Highlights: • A method of clustering customers by variability indices is developed. • Customers in high-variability clusters provide substantial peak reductions. • Low-variability clusters exhibit limited reductions. • For low-variability customers, alternative policy instruments is well advised. • A model of discerning customer's demand response potential is suggested.

  19. Development of Ti-sheathed MgB2 wires with high critical current density

    International Nuclear Information System (INIS)

    Liang, G; Fang, H; Hanna, M; Yen, F; Lv, B; Alessandrini, M; Keith, S; Hoyt, C; Tang, Z; Salama, K

    2006-01-01

    Working towards developing lightweight superconducting magnets for future space and other applications, we have successfully fabricated mono-core Ti-sheathed MgB 2 wires by the powder-in-tube method. The wires were characterized by magnetization, electrical resistivity, x-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry measurements. The results indicate that the Ti sheath does not react with the magnesium and boron, and the present wire rolling process can produce MgB 2 wires with a superconducting volume fraction of at least 64% in the core. Using the Bean model, it was found that at 5 K, the magnetic critical current densities, J c , measured in magnetic fields of 0, 5, and 8 T are about 4.2 x 10 5 , 3.6 x 10 4 , and 1.4 x 10 4 A cm -2 , respectively. At 20 K and 0 T, the magnetic J c is about 2.4 x 10 5 A cm -2 . These results show that at zero and low fields, the values of the magnetic J c for Ti-sheathed MgB 2 wires are comparable with the best results available for the Fe-sheathed MgB 2 wires. At high fields, however, the J c for Ti-sheathed MgB 2 wires appears higher than that for the Fe-sheathed MgB 2 wires

  20. Formation of high aspect ratio polyamide-6 nanofibers via electrically induced double layer during electrospinning

    International Nuclear Information System (INIS)

    Nirmala, R.; Nam, Ki Taek; Park, Soo-Jin; Shin, Yu-Shik; Navamathavan, R.; Kim, Hak Yong

    2010-01-01

    In the present study, the formation of high aspect ratio nanofibers in polyamide-6 was investigated as a function of applied voltage ranging from 15 to 25 kV using electrospinning technique. All other experimental parameters were kept constant. The electrospun polyamide-6 nanofibers were characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF). FE-SEM images of polyamide-6 nanofibers showed that the diameter of the electrospun fiber was decreased with increasing applied voltage. At the critical applied voltage, the polymer solution was completely ionized to form the dense high aspect ratio nanofibers in between the main nanofibers. The diameter of the polyamide-6 nanofibers was observed to be in the range of 75-110 nm, whereas the high aspect ratio structures consisted of regularly distributed very fine nanofibers with diameters of about 9-28 nm. Trends in fiber diameter and diameter distribution were discussed for the high aspect ratio nanofibers. TEM results revealed that the formation of double layers in polyamide-6 nanofibers and then split-up into ultrafine fibers. The electrically induced double layer in combination with the polyelectrolytic nature of solution is proposed as the suitable mechanisms for the formation of high aspect ratio nanofibers in polyamide-6.

  1. High temperature superconductivity the road to higher critical temperature

    CERN Document Server

    Uchida, Shin-ichi

    2015-01-01

    This book presents an overview of material-specific factors that influence Tc and give rise to diverse Tc values for copper oxides and iron-based high- Tc superconductors on the basis of more than 25 years of experimental data, to most of which the author has made important contributions. The book then explains why both compounds are distinct from others with similar crystal structure and whether or not one can enhance Tc, which in turn gives a hint on the unresolved pairing mechanism. This is an unprecedented new approach to the problem of high-temperature superconductivity and thus will be inspiring to both specialists and non-specialists interested in this field.   Readers will receive in-depth information on the past, present, and future of high-temperature superconductors, along with special, updated information on what the real highest Tc values are and particularly on the possibility of enhancing Tc for each member material, which is important for application. At this time, the highest Tc has not been...

  2. Electricity

    International Nuclear Information System (INIS)

    Tombs, F.

    1983-01-01

    The subject is discussed, with particular reference to the electricity industry in the United Kingdom, under the headings; importance and scope of the industry's work; future fuel supplies (estimated indigenous fossil fuels reserves); outlook for UK energy supplies; problems of future generating capacity and fuel mix (energy policy; construction programme; economics and pricing; contribution of nuclear power - thermal and fast reactors; problems of conversion of oil-burning to coal-burning plant). (U.K.)

  3. Quantum critical point in high-temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Shaginyan, V.R. [Petersburg Nuclear Physics Institute, RAS, Gatchina 188300 (Russian Federation); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)], E-mail: vrshag@thd.pnpi.spb.ru; Amusia, M.Ya. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Popov, K.G. [Komi Science Center, Ural Division, RAS, Syktyvkar 167982 (Russian Federation); Stephanovich, V.A. [Opole University, Institute of Mathematics and Informatics, Opole 45-052 (Poland)], E-mail: stef@math.uni.opole.pl

    2009-02-02

    Recently, in high-T{sub c} superconductors (HTSC), exciting measurements have been performed revealing their physics in superconducting and pseudogap states and in normal one induced by the application of magnetic field, when the transition from non-Fermi liquid to Landau-Fermi liquid behavior occurs. We employ a theory, based on fermion condensation quantum phase transition which is able to explain facts obtained in the measurements. We also show, that in spite of very different microscopic nature of HTSC, heavy-fermion metals and 2D {sup 3}He, the physical properties of these three classes of substances are similar to each other.

  4. Anomalous electric field changes and high flash rate beneath a ...

    Indian Academy of Sciences (India)

    In spite of many experimental and theoretical studies the relationships between storm dynamics, severe weather,and lightning activity have been least understood.Measurements of electric field made under a severe thunderstorm at a northeastern Indian station,Guwahati,India are reported. Lightning flash rate increases ...

  5. Electrical conductivity of highly ionized dense hydrogen plasma

    International Nuclear Information System (INIS)

    Radtke, R.; Guenther, K.

    1976-01-01

    A diagnostic technique for the determination of pressure, temperature and its radial distribution, the strength of the electric field and the current of a wall-stabilized pulse hydrogen arc at a pressure of 10 atm and a maximum power of 120 kW/cm arc length is developed. (author)

  6. Electrical and microstructural characterization of silver sheathed high Tc superconductors wires and ribbons

    International Nuclear Information System (INIS)

    Chaffron, L.; Regnier, P.; Schmirgeld, L.; Maurice, F.; Aguillon, C.; Senoussi, S.

    1991-01-01

    High Tc superconductors wires and ribbons were prepared according to the powder in tube method. It is shown that the electrical performances of the so prepared superconductors can be considerably improved, first by increasing as much as possible the density of the green body before sintering, and afterwards by melt texturing the sintered conductors. Some measurements of the transport critical current density of our conductors as a function of their diameter or their thickness are then presented and compared with indirect values obtained via the Bean method. The highest transport Jc measured in the present study, before melt texturing, are: 2250 and 5100 A/cm 2 at 77 and 63 K respectively, for a 50 μm thick silver sheathed ribbon. These figures compare nicely with the values of the intergranular critical current densities determined from magnetic measurements which are: 2100 and 5000 A/cm 2 at the same temperatures, and 40000 A/cm 2 at 4.2 K. Much higher intergranular values, in the range of 10 5 A/cm 2 were obtained after melt texturing the wires. Finally, microstructural characterizations carried out by X-ray diffraction, electron microprobe analysis and transmission electron microscopy are reported and discussed

  7. A critical study of high efficiency deep grinding

    International Nuclear Information System (INIS)

    Johnstone, Iain

    2002-01-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experimental and theoretical means applied to two widely used materials, M50 bearing steel and IN718 nickel based superalloy. It has been shown that this grinding method using a stiff grinding centre such as the Edgetek 5-axis machine is a viable process. Using a number of experimental designs, produced results which were analysed using a variety of methods including visual assessment, sub-surface microscopy and surface analysis using a Scanning Electron Microscope (SEM), residual stress measurement using X-Ray Diffraction (XRD) techniques, Barkhausen Noise Amplitude (BNA) measurements, surface roughness and Vickers micro-hardness appraisal. It has been shown that the fundamentals of the HEDG process have been understood through experimental as well as theoretical means and that through the various thermal models used, grinding temperatures can be predicted to give more control over this dynamic process. The main contributions to knowledge are made up of a number of elements within the grinding environment, the most important being the demonstration of the HEDG effect, explanation of the phenomenon and the ability to model the process. It has also been shown that grinding is a dynamic process and factors such as wheel wear will result in a continuous change in the optimum grinding conditions for a given material and wheel combination. With the significance of these factors recognised, they can be accounted for within an industrial adaptive control scenario with the process engineer confident of a

  8. Criticality Safety Evaluation of Hanford Site High Level Waste Storage Tanks

    Energy Technology Data Exchange (ETDEWEB)

    ROGERS, C.A.

    2000-02-17

    This criticality safety evaluation covers operations for waste in underground storage tanks at the high-level waste tank farms on the Hanford site. This evaluation provides the bases for criticality safety limits and controls to govern receipt, transfer, and long-term storage of tank waste. Justification is provided that a nuclear criticality accident cannot occur for tank farms operations, based on current fissile material and operating conditions.

  9. Criticality Safety Evaluation of Hanford Site High-Level Waste Storage Tanks

    International Nuclear Information System (INIS)

    ROGERS, C.A.

    2000-01-01

    This criticality safety evaluation covers operations for waste in underground storage tanks at the high-level waste tank farms on the Hanford site. This evaluation provides the bases for criticality safety limits and controls to govern receipt, transfer, and long-term storage of tank waste. Justification is provided that a nuclear criticality accident cannot occur for tank farms operations, based on current fissile material and operating conditions

  10. High Energy Density and High Temperature Multilayer Capacitor Films for Electric Vehicle Applications

    Science.gov (United States)

    Treufeld, Imre; Song, Michelle; Zhu, Lei; Baer, Eric; Snyder, Joe; Langhe, Deepak

    2015-03-01

    Multilayer films (MLFs) with high energy density and high temperature capability (>120 °C) have been developed at Case Western Reserve University. Such films offer a potential solution for electric car DC-link capacitors, where high ripple currents and high temperature tolerance are required. The current state-of-the-art capacitors used in electric cars for converting DC to AC use biaxially oriented polypropylene (BOPP), which can only operate at temperatures up to 85 °C requiring an external cooling system. The polycarbonate (PC)/poly(vinylidene fluoride) (PVDF) MLFs have a higher permittivity compared to that of BOPP (2.3), leading to higher energy density. They have good mechanical stability and reasonably low dielectric losses at 120 °C. Nonetheless, our preliminary dielectric measurements show that the MLFs exhibit appreciable dielectric losses (20%) at 120 °C, which would, despite all the other advantages, make them not suitable for practical applications. Our preliminary data showed that dielectric losses of the MLFs at 120 °C up to 400 MV/m and 1000 Hz originate mostly from impurity ionic conduction. This work is supported by the NSF PFI/BIC Program (IIP-1237708).

  11. Review of the Dynamics of Coalescence and Demulsification by High-Voltage Pulsed Electric Fields

    Directory of Open Access Journals (Sweden)

    Ye Peng

    2016-01-01

    Full Text Available The coalescence of droplets in oil can be implemented rapidly by high-voltage pulse electric field, which is an effective demulsification dehydration technological method. At present, it is widely believed that the main reason of pulse electric field promoting droplets coalescence is the dipole coalescence and oscillation coalescence in pulse electric field, and the optimal coalescence pulse electric field parameters exist. Around the above content, the dynamics of high-voltage pulse electric field promoting the coalescence of emulsified droplets is studied by researchers domestically and abroad. By review, the progress of high-voltage pulse electric field demulsification technology can get a better understanding, which has an effect of throwing a sprat to catch a whale on promoting the industrial application.

  12. Critical factors for assembling a high volume of DNA barcodes

    Science.gov (United States)

    Hajibabaei, Mehrdad; deWaard, Jeremy R; Ivanova, Natalia V; Ratnasingham, Sujeevan; Dooh, Robert T; Kirk, Stephanie L; Mackie, Paula M; Hebert, Paul D.N

    2005-01-01

    Large-scale DNA barcoding projects are now moving toward activation while the creation of a comprehensive barcode library for eukaryotes will ultimately require the acquisition of some 100 million barcodes. To satisfy this need, analytical facilities must adopt protocols that can support the rapid, cost-effective assembly of barcodes. In this paper we discuss the prospects for establishing high volume DNA barcoding facilities by evaluating key steps in the analytical chain from specimens to barcodes. Alliances with members of the taxonomic community represent the most effective strategy for provisioning the analytical chain with specimens. The optimal protocols for DNA extraction and subsequent PCR amplification of the barcode region depend strongly on their condition, but production targets of 100K barcode records per year are now feasible for facilities working with compliant specimens. The analysis of museum collections is currently challenging, but PCR cocktails that combine polymerases with repair enzyme(s) promise future success. Barcode analysis is already a cost-effective option for species identification in some situations and this will increasingly be the case as reference libraries are assembled and analytical protocols are simplified. PMID:16214753

  13. Analysis of Critical Permeabilty, Capillary Pressure and Electrical Properties for Mesaverde Tight Gas Sandstones from Western U.S. Basins

    Energy Technology Data Exchange (ETDEWEB)

    Alan Byrnes; Robert Cluff; John Webb; John Victorine; Ken Stalder; Daniel Osburn; Andrew Knoderer; Owen Metheny; Troy Hommertzheim; Joshua Byrnes; Daniel Krygowski; Stefani Whittaker

    2008-06-30

    Although prediction of future natural gas supply is complicated by uncertainty in such variables as demand, liquefied natural gas supply price and availability, coalbed methane and gas shale development rate, and pipeline availability, all U.S. Energy Information Administration gas supply estimates to date have predicted that Unconventional gas sources will be the dominant source of U.S. natural gas supply for at least the next two decades (Fig. 1.1; the period of estimation). Among the Unconventional gas supply sources, Tight Gas Sandstones (TGS) will represent 50-70% of the Unconventional gas supply in this time period (Fig. 1.2). Rocky Mountain TGS are estimated to be approximately 70% of the total TGS resource base (USEIA, 2005) and the Mesaverde Group (Mesaverde) sandstones represent the principal gas productive sandstone unit in the largest Western U.S. TGS basins including the basins that are the focus of this study (Washakie, Uinta, Piceance, northern Greater Green River, Wind River, Powder River). Industry assessment of the regional gas resource, projection of future gas supply, and exploration programs require an understanding of reservoir properties and accurate tools for formation evaluation. The goal of this study is to provide petrophysical formation evaluation tools related to relative permeability, capillary pressure, electrical properties and algorithms for wireline log analysis. Detailed and accurate moveable gas-in-place resource assessment is most critical in marginal gas plays and there is need for quantitative tools for definition of limits on gas producibility due to technology and rock physics and for defining water saturation. The results of this study address fundamental questions concerning: (1) gas storage; (2) gas flow; (3) capillary pressure; (4) electrical properties; (5) facies and upscaling issues; (6) wireline log interpretation algorithms; and (7) providing a web-accessible database of advanced rock properties. The following text

  14. Proposal and Development of a High Voltage Variable Frequency Alternating Current Power System for Hybrid Electric Aircraft

    Science.gov (United States)

    Sadey, David J.; Taylor, Linda M.; Beach, Raymond F.

    2017-01-01

    The development of ultra-efficient commercial vehicles and the transition to low-carbon emission propulsion are seen as strategic thrust paths within NASA Aeronautics. A critical enabler to these paths comes in the form of hybrid electric propulsion systems. For megawatt-class systems, the best power system topology for these hybrid electric propulsion systems is debatable. Current proposals within NASA and the Aero community suggest using a combination of alternating current (AC) and direct current (DC) for power generation, transmission, and distribution. This paper proposes an alternative to the current thought model through the use of a primarily high voltage AC power system, supported by the Convergent Aeronautics Solutions (CAS) Project. This system relies heavily on the use of doubly-fed induction machines (DFIMs), which provide high power densities, minimal power conversion, and variable speed operation. The paper presents background on the activity along with the system architecture, development status, and preliminary results.

  15. The Relationship between Critical Thinking Abilities and Classroom Management Skills of High School Teachers

    Science.gov (United States)

    Demirdag, Seyithan

    2015-01-01

    High school teachers experience difficulties while providing effective teaching approaches in their classrooms. Some of the difficulties are associated with the lack of classroom management skills and critical thinking abilities. This quantitative study includes non-random selection of the participants and aims to examine critical thinking…

  16. High exhaust temperature, zoned, electrically-heated particulate matter filter

    Science.gov (United States)

    Gonze, Eugene V.; Paratore, Jr., Michael J.; Bhatia, Garima

    2015-09-22

    A system includes a particulate matter (PM) filter, an electric heater, and a control circuit. The electric heater includes multiple zones, which each correspond to longitudinal zones along a length of the PM filter. A first zone includes multiple discontinuous sub-zones. The control circuit determines whether regeneration is needed based on an estimated level of loading of the PM filter and an exhaust flow rate. In response to a determination that regeneration is needed, the control circuit: controls an operating parameter of an engine to increase an exhaust temperature to a first temperature during a first period; after the first period, activates the first zone; deactivates the first zone in response to a minimum filter face temperature being reached; subsequent to deactivating the first zone, activates a second zone; and deactivates the second zone in response to the minimum filter face temperature being reached.

  17. Electric Field Induced Strain in Electrostrictive Polymers Under High Hydrostatic Pressure - System Development and Material Characterization

    National Research Council Canada - National Science Library

    Zhang, Q

    2000-01-01

    ... of (i) developing a high performance piezo-bimorph based dilatometer which can be used to characterize the electric field induced strain response in polymer films under high hydrostatic pressure, (ii...

  18. Ultrahigh hardness and high electrical resistivity in nano-twinned, nanocrystalline high-entropy alloy films

    Science.gov (United States)

    Huo, Wenyi; Liu, Xiaodong; Tan, Shuyong; Fang, Feng; Xie, Zonghan; Shang, Jianku; Jiang, Jianqing

    2018-05-01

    Nano-twinned, nanocrystalline CoCrFeNi high-entropy alloy films were produced by magnetron sputtering. The films exhibit a high hardness of 8.5 GPa, the elastic modulus of 161.9 GPa and the resistivity as high as 135.1 μΩ·cm. The outstanding mechanical properties were found to result from the resistance of deformation created by nanocrystalline grains and nano-twins, while the electrical resistivity was attributed to the strong blockage effect induced by grain boundaries and lattice distortions. The results lay a solid foundation for the development of advanced films with structural and functional properties combined in micro-/nano-electronic devices.

  19. High Penetration of Electrical Vehicles in Microgrids: Threats and Opportunities

    Science.gov (United States)

    Khederzadeh, Mojtaba; Khalili, Mohammad

    2014-10-01

    Given that the microgrid concept is the building block of future electric distribution systems and electrical vehicles (EVs) are the future of transportation market, in this paper, the impact of EVs on the performance of microgrids is investigated. Demand-side participation is used to cope with increasing demand for EV charging. The problem of coordination of EV charging and discharging (with vehicle-to-grid (V2G) functionality) and demand response is formulated as a market-clearing mechanism that accepts bids from the demand and supply sides and takes into account the constraints put forward by different parts. Therefore, a day-ahead market with detailed bids and offers within the microgrid is designed whose objective is to maximize the social welfare which is the difference between the value that consumers attach to the electrical energy they buy plus the benefit of the EV owners participating in the V2G functionality and the cost of producing/purchasing this energy. As the optimization problem is a mixed integer nonlinear programming one, it is decomposed into one master problem for energy scheduling and one subproblem for power flow computation. The two problems are solved iteratively by interfacing MATLAB with GAMS. Simulation results on a sample microgrid with different residential, commercial and industrial consumers with associated demand-side biddings and different penetration level of EVs support the proposed formulation of the problem and the applied methods.

  20. Potentially damaging failure modes of high- and medium-voltage electrical equipment

    International Nuclear Information System (INIS)

    Hoy, H.C.

    1984-01-01

    The high- and medium-voltage electrical equipment failures of both nuclear and nonnuclear electric utilities have been reviewed for possible disruptive failure modes that would be of special concern in a nuclear power plant. The resulting emphasis was on the electrical faults of transformers, switchgear (circuit breakers), lightning (surge) arrestors, high-voltage cabling and buswork, control boards, and other electrical equipment that, through failure, can be the initiating event that may expand the original fault to nearby or associated equipment. Many failures of such equipment were found and documented, although the failure rate of electrical equipment in utilities is historically quite low. Nuclear plants record too few failures to be statistically valid, but failures that have been recorded show that good design usually restricts the failure to a single piece of equipment. Conclusions and recommendations pertaining to the design, maintenance, and operation of the affected electrical equipment are presented

  1. Recycling-Oriented Product Characterization for Electric and Electronic Equipment as a Tool to Enable Recycling of Critical Metals

    Science.gov (United States)

    Rotter, Vera Susanne; Chancerel, Perrine; Ueberschaar, Maximilian

    To establish a knowledge base for new recycling processes of critical elements, recycling-orientated product characterization for Electric and Electronic Equipment (EEE) can be used as a tool. This paper focuses on necessary data and procedures for a successful characterization and provides information about existing scientific work. The usage of this tool is illustrated for two application: Hard Disk Drives (HDD) and Liquid Crystal Display (LCD) panels. In the first case it could be shown that Neodymium and other Rare Earth Elements are concentrated in magnets (25% by weight) and contribute largely to the end demand of Neodymium. Nevertheless, recycling is limited by the difficult liberation and competing other target metals contained in HDD. In the second case it could be shown that also for this application the usage of Indium is concentrated in LCDs, but unlike in magnets the concentration is lower (200 ppm). The design of LCDs with two glued glass layers and the Indium-Tin-Oxide layer in between make the Indium inaccessible for hydro-metallurgical recovery, the glass content puts energetic limitations on pyro-metallurgical processes. For the future technical development of recycling infrastructure we need an in depth understanding of product design and recycling relevant parameters for product characterization focusing on new target metals. This product-centered approach allows also re-think traditional "design for recycling" approaches.

  2. Correction: Towards the rationalization of catalytic activity values by means of local hyper-softness on the catalytic site: a criticism about the use of net electric charges.

    Science.gov (United States)

    Martínez-Araya, Jorge Ignacio; Grand, André; Glossman-Mitnik, Daniel

    2016-01-28

    Correction for 'Towards the rationalization of catalytic activity values by means of local hyper-softness on the catalytic site: a criticism about the use of net electric charges' by Jorge Ignacio Martínez-Araya et al., Phys. Chem. Chem. Phys., 2015, DOI: 10.1039/c5cp03822g.

  3. Advanced ceramic composite for high energy resistors. Characterization of electrical and physical properties

    International Nuclear Information System (INIS)

    Farrokh, Fattahi; Navid, Tagizadegan; Naser, Tabatabaei; Ahmad, Rashtehizadeh

    2005-01-01

    There is a need to characterize and apply advanced materials to improve the performance of components used in pulse power systems. One area of innovation is the use of bulk electrically conductive ceramics for non-inductive, high energy and high power electrical resistors. Standard Ceramics Inc. has developed a unique silicon carbide structural ceramic composite which exhibits electrical conductivity. The new conductive bulk ceramic material has a controlled microstructure, which results in improved homogeneity, making the material suitable for use as a non-inductive high energy resistor. This paper describes characterization of the material's physical and electrical properties and relates them to improvements in low-inductance, high temperature, high power density and high energy density resistors. The bulk resistor approach offers high reliability through better mechanical properties and simplicity of construction

  4. Critical thinking skills profile of high school students in learning chemistry

    Directory of Open Access Journals (Sweden)

    Budi Utami

    2017-08-01

    Full Text Available Critical thinking skill is the priority in the goals of education. In this case, the critical thinking has the higher process, such as analyzing, synthesizing, evaluating, drawing conclusion and reflecting which enables the individual to make the reasonable assessment both in the classroom and in the daily life.  This research is aimed to determine the students’ critical thinking skill in learning Chemistry at senior high school. This research used descriptive method in which the instruments were developed based on the indicators of critical thinking skill. The population of this research was 100 students of tenth, eleventh and twelfth grade from senior high schools in Surakarta which was chosen using cluster random sampling technique. The result of the research shows that the students of tenth, eleventh and twelfth grade have adequate critical thinking skills.

  5. Method for critical software event execution reliability in high integrity software

    Energy Technology Data Exchange (ETDEWEB)

    Kidd, M.E. [Sandia National Labs., Albuquerque, NM (United States)

    1997-11-01

    This report contains viewgraphs on a method called SEER, which provides a high level of confidence that critical software driven event execution sequences faithfully exceute in the face of transient computer architecture failures in both normal and abnormal operating environments.

  6. Some biological effects of high-voltage stationary electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, V.V.; Dobrov, N.N.; Drobyshev, V.I.; Koroleva, L.V.; Nikitin, M.D.; Petrukhin, S.V.; Semonova, L.A.; Fedorov, V.P.

    The experiments were carried out on 345 white mice using hematological and pathomorphological procedures. The constant electric field (CEF) was generated in a special laboratory device. The exposure to CEF of 50 and 100 kV/m for 20 s caused hematological and morphological changes typical of the anxiety stage of the adaptation syndrome. The exposure also produced morphological changes of reactive and destructive type in skeletal muscles and different segments of kinesthetic receptors. The level of the above changes appears to be directly related to the CEF strength. 6 references, 4 figures, 1 table.

  7. Electrical conductivity of molten SnCl{sub 2} at temperature as high as 1314 K

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, Alexander B.; Potapov, Alexei M. [Ural Branch of RAS, Ekaterinburg (Russian Federation). Inst. of High-Temperature Electrochemistry

    2015-07-01

    The electrical conductivity of molten SnCl{sub 2} was measured in a wide temperature range (ΔT=763 K), from 551 K to temperature as high as 1314 K, that is, 391 above the boiling point of the salt. The specific electrical conductance was found to reach its maximum at 1143 K, after that it decreases with the temperature rising.

  8. High Performance Electrical Modeling and Simulation Verification Test Suite - Tier I; TOPICAL

    International Nuclear Information System (INIS)

    SCHELLS, REGINA L.; BOGDAN, CAROLYN W.; WIX, STEVEN D.

    2001-01-01

    This document describes the High Performance Electrical Modeling and Simulation (HPEMS) Global Verification Test Suite (VERTS). The VERTS is a regression test suite used for verification of the electrical circuit simulation codes currently being developed by the HPEMS code development team. This document contains descriptions of the Tier I test cases

  9. Electrical conductivity of molten SnCl2 at temperature as high as 1314 K

    International Nuclear Information System (INIS)

    Salyulev, Alexander B.; Potapov, Alexei M.

    2015-01-01

    The electrical conductivity of molten SnCl 2 was measured in a wide temperature range (ΔT=763 K), from 551 K to temperature as high as 1314 K, that is, 391 above the boiling point of the salt. The specific electrical conductance was found to reach its maximum at 1143 K, after that it decreases with the temperature rising.

  10. High-latitude long-period pulsations in the atmospheric electricity according to observations at Schpitzbergen

    International Nuclear Information System (INIS)

    Klejmenova, N.G.; Kozyreva, O.V.; Mikhnovski, S.; Shimanski, A.; Ermolenko, D.Yu.

    1992-01-01

    The spectrum of long-period oscillations in the electric and magnetic fields is investigated for the first time using the data on simultaneous digital recording in the high altitudes at Schpitzbergen. It is established that during both tranquil and perturbed period at any time of the day, spectrum variation in electric and magnetic fields feature a decline discrete nature

  11. Effect of the microstructure on electrical properties of high-purity germanium

    Science.gov (United States)

    Podkopaev, O. I.; Shimanskii, A. F.; Molotkovskaya, N. O.; Kulakovskaya, T. V.

    2013-05-01

    The interrelation between the electrical properties and the microstructure of high-purity germanium crystals has been revealed. The electrical conductivity of polycrystalline samples increases and the life-time of nonequilibrium charge carriers in them decreases with a decrease in the crystallite sizes.

  12. Critical heat flux experiments for high conversion light water reactor, (3)

    International Nuclear Information System (INIS)

    Iwamura, Takamichi; Okubo, Tsutomu; Suemura, Takayuki; Hiraga, Fujio; Murao, Yoshio

    1990-03-01

    As a part of the thermal-hydraulic feasibility study of a high conversion light water reactor (HCLWR), critical heat flux (CHF) experiments were performed using triangular array rod bundles under steady-state and flow reduction transient conditions. The geometries of test sections were: rod outer diameter 9.5 mm, number of rods 4∼7, heated length 0.5∼1.0 m, and pitch to diameter ratio (P/D) 1.126∼1.2. The simulated fuel rod was a stainless steel tube and uniformly heated electrically with direct current. In the steady-state tests, pressures ranged: 1.0∼3.9 Mpa, mass velocities: 460∼4270 kg/s·m 2 , and exit qualities: 0.02∼0.35. In the transient tests, the times to CHF detection ranged from 0.5 to 25.4 s. The steady-state CHF's for the 4-rod test sections were higher than those for the 7-rod test sections with respect to the bundle averaged flow conditions. The measured CHF's increased with decreasing the heated length and decreased with decreasing the P/D. Based on the local flow conditions obtained with the subchannel analysis code COBRA-IV-I, KfK correlation agreed with the CHF data within 20 %, while WSC-2, EPRI-B and W, EPRI-Columbia and Kattor correlations failed to give satisfactory agreements. Under flow reduction rates less than 6 %/s, no significant difference in the onset conditions of DNB (departure from nucleate boiling) was recognized between the steady-state and transient conditions. At flow reduction rates higher than 6 %/s, on the other hand, the DNB occurred earlier than the DNB time predicted with the steady-state experiments. (author)

  13. Dealing Collectively with Critical Incident Stress Reactions in High Risk Work Environments

    DEFF Research Database (Denmark)

    Müller-Leonhardt, Alice; Strøbæk, Pernille Solveig; Vogt, joachim

    2015-01-01

    organisations. Indeed, we found that the CISM programme once integrated within the socio-cultural patterns of this specific working environment enhanced not only individual feelings of being supported but also organisational safety culture. Keywords: coping; safety culture; critical incident stress management......aim of this paper is to shift the representation of coping patterns within high risk occupations to an existential part of cultural pattern and social structure, which characterises high reliability organisations. Drawing upon the specific peer model of critical incident stress management (CISM......), in which qualified operational peers support colleagues who experienced critical incident stress, the paper discusses critical incident stress management in air traffic control. Our study revealed coping patterns that co-vary with the culture that the CISM programme fostered within this specific high...

  14. Accelerated reliability testing of highly aligned single-walled carbon nanotube networks subjected to DC electrical stressing.

    Science.gov (United States)

    Strus, Mark C; Chiaramonti, Ann N; Kim, Young Lae; Jung, Yung Joon; Keller, Robert R

    2011-07-01

    We investigate the electrical reliability of nanoscale lines of highly aligned, networked, metallic/semiconducting single-walled carbon nanotubes (SWCNTs) fabricated through a template-based fluidic assembly process. We find that these SWCNT networks can withstand DC current densities larger than 10 MA cm(-2) for several hours and, in some cases, several days. We develop test methods that show that the degradation rate, failure predictability and total device lifetime can be linked to the initial resistance. Scanning electron and transmission electron microscopy suggest that fabrication variability plays a critical role in the rate of degradation, and we offer an empirical method of quickly determining the long-term performance of a network. We find that well-fabricated lines subject to constant electrical stress show a linear accumulation of damage reminiscent of electromigration in metallic interconnects, and we explore the underlying physical mechanisms that could cause such behavior.

  15. Multilayered Functional Insulation System (MFIS) for AC Power Transmission in High Voltage Hybrid Electrical Propulsion

    Science.gov (United States)

    Lizcano, Maricela

    2017-01-01

    High voltage hybrid electric propulsion systems are now pushing new technology development efforts for air transportation. A key challenge in hybrid electric aircraft is safe high voltage distribution and transmission of megawatts of power (>20 MW). For the past two years, a multidisciplinary materials research team at NASA Glenn Research Center has investigated the feasibility of distributing high voltage power on future hybrid electric aircraft. This presentation describes the team's approach to addressing this challenge, significant technical findings, and next steps in GRC's materials research effort for MW power distribution on aircraft.

  16. Advanced ceramic composite for high energy resistors : Characterization of electrical and physical properties

    International Nuclear Information System (INIS)

    Farrokh, Fattahi; Navid, Tagizadegan; Naser, Tabatabaei; Ahmad, Rashtehizadeh

    2005-01-01

    There is a need to characterize and apply advanced materials to improve the performance of components used in pulse power systems. One area for innovation is the use of bulk electrically conductive ceramics for non-inductive, high energy and high power electrical resistors. Standard Ceramics Inc. has developed a unique silicon carbide structural ceramic composite which exhibits electrical conductivity. The new, new, conductive, bulk ceramic material has a controlled microstructure, which results in improved homogeneity, making the material suitable for use as a non-inductive, high energy resistor

  17. Electricity demand profile with high penetration of heat pumps in Nordic area

    DEFF Research Database (Denmark)

    Liu, Zhaoxi; Wu, Qiuwei; Nielsen, Arne Hejde

    2013-01-01

    This paper presents the heat pump (HP) demand profile with high HP penetration in the Nordic area in order to achieve the carbon neutrality power system. The calculation method in the European Standard EN14825 was used to estimate the HP electricity demand profile. The study results show...... there will be high power demand from HPs and the selection of supplemental heating for heat pumps has a big impact on the peak electrical power load of heating. The study in this paper gives an estimate of the scale of the electricity demand with high penetration of heat pumps in the Nordic area....

  18. High-performance electrically conductive silver paste prepared by silver-containing precursor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jianguo; Cao, Yu; Li, Xiangyou; Wang, Xiaoye; Zeng, Xiaoyan [Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics, College of Optoelectronics Science and Engineering, Wuhan (China)

    2010-09-15

    A high-performance electrically conductive silver paste with no solid particles before drying and/or sintering is developed, in which silver-containing precursor is employed as conductive functional phase. Thermogravimetry analysis, volume electrical resistivity tests and sintering experiments show that the paste with about 14 wt.% silver pristine content is able to achieve the volume electrical resistivity of (2-3) x 10{sup -5} {omega} cm after it is sintered at 220 C. A micro-pen direct-writing process indicates that it is very suitable for the fabrication of high-resolution (25 {mu}m) and high-integration devices and apparatus. (orig.)

  19. Preparation of high critical temperature YBa2Cu3O7 superconducting coatings by thermal spray

    International Nuclear Information System (INIS)

    Lacombe, Jacques

    1991-01-01

    The objective of this research thesis is the elaboration of YBa 2 Cu 3 O 7 superconducting coatings by thermal spray. These coatings must have a high adherence, a high cohesion, and the best possible electrical characteristics. The author first briefly presents physical-chemical characteristics of this ceramic, and proposes a bibliographical synthesis on thick coatings prepared by thermal spray. In the next parts, he studies and describes conditions of elaboration of poly-granular coatings of YBa 2 Cu 3 O 7 , and their structural and electric characteristics [fr

  20. High resolution electrical resistivity tomography of golf course greens irrigated with reclaimed wastewater: Hydrological approach

    Science.gov (United States)

    Tapias, Josefina C.; Lovera, Raúl; Himi, Mahjoub; Gallardo, Helena; Sendrós, Alexandre; Marguí, Eva; Queralt, Ignasi; Casas, Albert

    2014-05-01

    Actually, there are over 300 golf courses and more than three thousand licensed players in Spain. For this reason golf cannot be considered simply a hobby or a sport, but a very significant economic activity. Considered as one of the most rapidly expanding land-use and water demanding business in the Mediterranean, golf course development generates controversy. In the recent years there has been a considerable demand for golf courses to adopt environmentally sustainable strategies and particularly water authorities are forcing by law golf managers to irrigate with alternative water resources, mainly reclaimed wastewater. Watering practices must be based on soil properties that are characterized by samples removed from the different zones of the golf course and submitted to an accredited physical soil testing laboratory. Watering schedules are critical on greens with poor drainage or on greens with excessively high infiltration rates. The geophysical survey was conducted over the greens of the Girona Golf Club. Eighteen electrical resistivity tomographies were acquired using a mixed Wenner-Schlumberger configuration with electrodes placed 0.5 meter apart. Small stainless-steel nails were used as electrodes to avoid any damage in the fine turfgrass of greens The resistivity meter was set for systematically and automatically selects current electrodes and measurement electrodes to sample apparent resistivity values. Particle size analysis (PSA) has been performed on soil materials of any putting green. The PSA analysis has been composed of two distinct phases. The first has been the textural analysis of the soils for determining the content of sand, silt, and clay fraction via the use of a stack of sieves with decreasing sized openings from the top sieve to the bottom. Subsequently, the hydraulic conductivity of the substrates has been evaluated by means of Bredding and Hazen empirical relationships. The results of this research show that the electrical resistivity

  1. High impact ionization rate in silicon by sub-picosecond THz electric field pulses (Conference Presentation)

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Hirori, Hideki

    2017-01-01

    Summary form only given. Metallic antenna arrays fabricated on high resistivity silicon are used to localize and enhance the incident THz field resulting in high electric field pulses with peak electric field strength reaching several MV/cm on the silicon surface near the antenna tips. In such high...... electric field strengths high density of carriers are generated in silicon through impact ionization process. The high density of generated carriers induces a change of refractive index in silicon. By measuring the change of reflectivity of tightly focused 800 nm light, the local density of free carriers...... near the antenna tips is measured. Using the NIR probing technique, we observed that the density of carriers increases by over 8 orders of magnitude in a time duration of approximately 500 fs with an incident THz pulse of peak electric field strength 700 kV/cm. This shows that a single impact...

  2. A visual acoustic high-pressure cell for the study of critical behavior of nonsimple mixtures

    Science.gov (United States)

    Aguiar-Ricardo, A.; Temtem, M.; Casimiro, T.; Ribeiro, N.

    2004-10-01

    A visual acoustic high-pressure cell was constructed for the determination of critical data of multicomponent mixtures. The cell was specially designed to include two piezoelectric transducers and two sapphire windows that make this cell well suited to investigate the critical behavior of mixtures, simultaneously using the acoustic technique and the direct visual inspection of the critical opalescence. Critical data obtained on the binary mixtures of CO2+CHF3 were used for comparison with values given in literature using the traditional methods. The acoustic results are in agreement with those obtained by the conventional methods, within the combined experimental errors. Comparison of visual and acoustic data enabled the evaluation of the applicability of the acoustic technique to study the critical behavior of multicomponent mixtures.

  3. High-frequency thermal-electrical cycles for pyroelectric energy conversion

    International Nuclear Information System (INIS)

    Bhatia, Bikram; Damodaran, Anoop R.; Cho, Hanna; Martin, Lane W.; King, William P.

    2014-01-01

    We report thermal to electrical energy conversion from a 150 nm thick BaTiO 3 film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 10 5  kV/cm-s, and temperature change rates as high as 6 × 10 5  K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cycles are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems

  4. High Temperature Electrical Insulation Materials for Space Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's future space science missions cannot be realized without the state of the art high temperature insulation materials of which higher working temperature, high...

  5. Evaluation of electrical crosstalk in high-density photodiode arrays for X-ray imaging applications

    International Nuclear Information System (INIS)

    Ji Fan; Juntunen, Mikko; Hietanen, Iiro

    2009-01-01

    Electrical crosstalk is one of the important parameters in the photodiode array detector for X-ray imaging applications, and it becomes more important when the density of the photodiode array becomes higher. This paper presents the design of the high-density photodiode array with 250 μm pitch and 50 μm gap. The electrical crosstalk of the demonstrated samples is evaluated and compared with different electrode configurations: cathode bias mode and anode bias mode. The measurement results show good electrical crosstalk, ∼0.23%, in cathode bias mode regardless of the bias voltage, and slightly decreased or increased electrical crosstalk in anode bias mode. Moreover, the quantum efficiency is also evaluated from the same samples, and it behaves similar to the electrical crosstalk. Finally, some design guidance of the high-density photodiode array is given based on the discussion.

  6. The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone.

    Science.gov (United States)

    Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

    2014-04-01

    High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network

  7. Transport measurements in superconductors: critical current of granular high TC ceramic superconductor samples; Medidas de transporte em supercondutores: corrente critica de supercondutores granulares de alta temperatura critica

    Energy Technology Data Exchange (ETDEWEB)

    Passos, W.A.C., E-mail: wagner.passos@univasf.edu.br [Universidade Federal do Vale do Sao Francisco (IPCM/UNIVASF), Juazeiro do Norte, BA (Brazil). Instituto de Pesquisas em Ciencia dos Materiais; Silva, E.B. [Companhia Energetica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2016-07-01

    This work presents a method to obtain critical current of granular superconductors. We have carried out transport measurements (ρxT curves and VxI curves) in a YBa{sub 2}Cu{sub 3}O{sub 7-δ} sample to determine critical current density of it. Some specimens reveal a 'semiconductor-like' behavior (electrical resistivity decreases with increasing temperatures above critical temperature T{sub c} of material) competing with superconductor behavior. Due to high granular fraction of the sample, these competition is clearly noted in ρxT curves. Measurements carried out from 0 to 8500 Oe of applied field show the same behavior, and the critical current density of the samples is shown. (author)

  8. Integrating High Levels of Variable Renewable Energy into Electric Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, Benjamin D. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-01

    As more variable renewable energy is integrated into electric power systems, there are a range of challenges and solutions to accommodating very high penetration levels. This presentation highlights some of the recent research in this area.

  9. Electricity

    Indian Academy of Sciences (India)

    Michael Faraday of England and Joseph Henry of the United. States are the .... frequency to be generated is f Hz, the number of poles required .... it would seem there is a very good reason to choose high frequency power generation. (In fact.

  10. Theoretical upper critical field Hc2 for inhomogeneous high temperature superconductors

    International Nuclear Information System (INIS)

    Caixeiro, E.S.; Gonzalez, J.L.; Mello, E.V.L. de

    2004-01-01

    We present the theoretical upper critical field H c2 (T) of the high temperature superconductors (HTSC), calculated through a linearized Ginzburg-Landau equation modified to consider the intrinsic inhomogeneity of the HTSC. The unusual behavior of H c2 (T) for these compounds, and other properties like the Meissner and Nernst effects detected at temperatures much higher than the critical temperature T c of the sample, are explained by the approach

  11. Development of E-Book Multimedia Model to Increase Critical Thinking of Senior High School Students

    OpenAIRE

    Suparno Suparno

    2018-01-01

    This study aims to develop the interactive e-book multimedia model to improve the students' critical thinking ability (KBK). Critical thinking is very important to develop because it provides a high level of reasoning thinking that provides permanent experience to students through conscious and controlled decision making in a rational, reflective, responsible manner with the optimization of potential. Flash-based e-book media is capable of interactively loading videos, pictures, practice ques...

  12. The electric strength of high-voltage transformers insulation at effect of partial dischargers

    International Nuclear Information System (INIS)

    Khoshravan, E.; Zeraatparvar, A.; Gashimov, A.M.; Mehdizadeh, R.N.

    2001-01-01

    Full text : In paper the change of electric strength of high-voltage transformers insulation at the effect of partial discharges with space charge accumulation was investigated. It is revealed that the effect of partial discharges of insulation materials results the reduction of their pulsing electric strength which can restore the own initial value at releasing of saved charge the volume of a material under condition of absence the ineversible structural changes in it. Researches of high-voltage transformers insulation's non-failure operation conditions show, that at increasing of insulation work time in a strong electrical field the reduction of average breakdown voltages with simultaneous increasing of spread in discharge voltage values takes place. It authentically testifies to reduction of short-time discharge voltage of insulation materials during their electrical aging. As the basic reason of insulation electrical aging the partial discharges occurring in gas cavities inside insulation were considered. It is known that the space charges will be formed in insulation elements of high-voltage devices which effects in dielectrical property of these elements including the electric strength and the space charge formation can occur also at partial discharges in an alternating voltage while the service of high-voltage transformers. In the given work the experiments in revealing separate influence partial discharges in pulsing electric strength of insulation materials at presence and at absence inside them the space charge were spent

  13. Rotor apparatus for high strength undiffused brushless electric machine

    Science.gov (United States)

    Hsu, John S [Oak Ridge, TN

    2006-01-24

    A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34) also has at least one stationary excitation coil (35a, 36a) separated from the rotor (32) by a secondary air gap (35e, 35f, 36e, 36f) so as to induce a secondary flux in the rotor (32) which controls a resultant flux in the main air gap (34). Permanent magnetic (PM) material (38) is disposed in spaces between the rotor pole portions (39) to inhibit the second flux from leaking from the pole portions (39) prior to reaching the main air gap (34). By selecting the direction of current in the stationary excitation coil (35a, 36a) both flux enhancement and flux weakening are provided for the main air gap (34). Improvements of a laminated rotor, an end pole structure, and an arrangement of the PM elements for providing an arrangement of the flux paths from the auxiliary field coil assemblies are also disclosed.

  14. High dislocation density of tin induced by electric current

    International Nuclear Information System (INIS)

    Liao, Yi-Han; Liang, Chien-Lung; Lin, Kwang-Lung; Wu, Albert T.

    2015-01-01

    A dislocation density of as high as 10 17 /m 2 in a tin strip, as revealed by high resolution transmission electron microscope, was induced by current stressing at 6.5 x 10 3 A/ cm 2 . The dislocations exist in terms of dislocation line, dislocation loop, and dislocation aggregates. Electron Backscattered Diffraction images reflect that the high dislocation density induced the formation of low deflection angle subgrains, high deflection angle Widmanstätten grains, and recrystallization. The recrystallization gave rise to grain refining

  15. A strategy for achieving low percolation and high electrical conductivity in melt-blended polycarbonate (PC/multiwall carbon nanotube (MWCNT nanocomposites: Electrical and thermo-mechanical properties

    Directory of Open Access Journals (Sweden)

    B. B. Khatua

    2013-06-01

    Full Text Available In this work, polycarbonate (PC/multiwall carbon nanotube (MWCNT nanocomposites were prepared by simple melt mixing at a temperature (~350°C well above the processing temperature of PC, followed by compression molding, that exhibited percolation threshold as low as of 0.11 wt% and high electrical conductivity of 1.38x10–3 S•cm–1 at only 0.5 wt% MWCNT loading. Due to the lower interfacial energy between MWCNT and PC, the carbon nanotubes are excellently dispersed and formed continuous conductive network structure throughout the host polymer. AC electrical conductivity and dielectric permittivity of PC/MWCNT nanocomposites were characterized in a broad frequency range, 101–107 Hz. Low percolation threshold (pc of 0.11 wt% and the critical exponent (t of ~3.38 was resulted from scaling law equation. The linear plot of logσDC vs. p–1/3 supported the presence of tunneling conduction among MWCNTs. The thermal property and storage modulus of PC were increased with the incorporation of little amount of MWCNTs. Transmission electron microscopy (TEM and field emission scanning electron microscopy (FESEM confirmed the homogeneous dispersion and distribution of MWCNTs throughout the matrix phase.

  16. Development of Assessment Instrument of Critical Thinking in Physics at Senior High School

    Science.gov (United States)

    Sugiarti, T.; Kaniawati, I.; Aviyanti, L.

    2017-02-01

    The result of preliminary study shows that the assessment of physics in school did not train students’ critical thinking skill. The assessment instrument just measured low cognitive aspects. Supposedly, critical thinking skill is trained in the assessment activity. The study aims to determine the characteristics and the quality of critical thinking skill instrument. It employs descriptive-qualitative method with research and development as the research design. The research participants are 35 students involved in the limited trial and 188 students in the wider trial from three public senior high school in Ciamis which in high level school. The data was collected through expert validation, tests and interviews. The results indicate that the characteristics of the assessment instrument of critical thinking skill is open-ended. The instrument fulfills some indicators namely analyzing argument, deduction, induction, and display information in the form of scenario, text, graphic and table. In addition, the data processing through V4 Anates program shows that the instrument reliability achieves 0.67 with high interpretation of 0.67 and the validity is 0.47 with enough interpretation. Thus, the assessment instrument of critical thinking skill in the form of open-ended essay meets the criteria of quality test, so it can use as instrument of assessment critical thinking skill.

  17. Critical thinking skills profile of senior high school students in Biology learning

    Science.gov (United States)

    Saputri, A. C.; Sajidan; Rinanto, Y.

    2018-04-01

    Critical thinking is an important and necessary skill to confront the challenges of the 21st century. Critical thinking skills accommodate activities that can improve high-order thinking skills. This study aims to determine senior high school students' critical thinking skills in Biology learning. This research is descriptive research using instruments developed based on the core aspects of critical thinking skills according to Facione which include interpretation, analysis, evaluation, explanation, conclusion, and self-regulation. The subjects in this study were 297 students in grade 12 of a senior high school in Surakarta selected through purposive sampling technique. The results of this study showed that the students' critical thinking skills on evaluation and self-regulation are in good criterion with 78% and 66% acquisition while 52% interpretation, 56% analysis, 52% conclusion and 42% explanation indicate sufficient criteria. The conclusion from this research is that critical thinking skill of the students still was in enough category, so that needed a way to enhance it on some indicators.

  18. High temperature electrical resistivity and Seebeck coefficient of Ge2Sb2Te5 thin films

    Science.gov (United States)

    Adnane, L.; Dirisaglik, F.; Cywar, A.; Cil, K.; Zhu, Y.; Lam, C.; Anwar, A. F. M.; Gokirmak, A.; Silva, H.

    2017-09-01

    High-temperature characterization of the thermoelectric properties of chalcogenide Ge2Sb2Te5 (GST) is critical for phase change memory devices, which utilize self-heating to quickly switch between amorphous and crystalline states and experience significant thermoelectric effects. In this work, the electrical resistivity and Seebeck coefficient are measured simultaneously as a function of temperature, from room temperature to 600 °C, on 50 nm and 200 nm GST thin films deposited on silicon dioxide. Multiple heating and cooling cycles with increasingly maximum temperature allow temperature-dependent characterization of the material at each crystalline state; this is in contrast to continuous measurements which return the combined effects of the temperature dependence and changes in the material. The results show p-type conduction (S > 0), linear S(T), and a positive Thomson coefficient (dS/dT) up to melting temperature. The results also reveal an interesting linearity between dS/dT and the conduction activation energy for mixed amorphous-fcc GST, which can be used to estimate one parameter from the other. A percolation model, together with effective medium theory, is adopted to correlate the conductivity of the material with average grain sizes obtained from XRD measurements. XRD diffraction measurements show plane-dependent thermal expansion for the cubic and hexagonal phases.

  19. Electrical injuries due to railway high tension cables.

    Science.gov (United States)

    Reichl, M; Kay, S

    1985-08-01

    We have noted a large number of young boys being admitted to our Unit with burns due to railway high tension cables. On review of these cases we have noted: most of the burns were due to arcing, there is a high level of ignorance among the population at risk. We propose some ways of preventing these injuries.

  20. High output power reluctance electric motors with bulk high-temperature superconductor elements

    Energy Technology Data Exchange (ETDEWEB)

    Kovalev, L.K. [Moscow State Aviation Institute (Technical University) (MAI), Moscow (Russian Federation)]. E-mail: kovalev@mail.sitek.net; Ilushin, K.V.; Penkin, V.T. [Moscow State Aviation Institute (Technical University) (MAI), Moscow (RU)] [and others

    2002-05-01

    We present new types of electric machines with the rotors containing bulk high-temperature superconductor (HTS)-YBCO and Bi-Ag-elements. We discuss different schematics of hysteresis, reluctance, 'trapped field' and composed synchronous HTS machines. The two-dimensional mathematical models describing the processes in such types of HTS machines were developed on the basis of the theoretical analysis of the electrodynamic and hysteresis processes in the single-domain and polycrystal YBCO ceramic samples and plate shape Bi-Ag elements. We give the test results of the series of hysteresis, reluctance, 'trapped field' and composed with permanent magnets HTS motors with an output power rating of 0.1-18 kW and current frequencies 50 Hz and 400 Hz. These results show that in the media of liquid nitrogen the specific output power per one unit weight of the HTS motor is four to seven times better than for conventional electric machines. A comparison of the theoretical and experimental characteristics of the developed HTS motors show that they are in good agreement. We discuss the test results for a liquid nitrogen cryogenic pump system with a hysteresis 500 W HTS motor. We describe several designs of new HTS motors operating in the media of liquid nitrogen with an output power 125 kW (and more) and a power factor of more than 0.8. We discuss future applications of new types of HTS motors for aerospace technology, on-land industry and transport systems. (author)

  1. Electrical and optical investigations of transient high pressure discharge phenomena

    International Nuclear Information System (INIS)

    Akishev, Yu.; Karal'nik, V.; Trushkin, N.

    2001-01-01

    The object of our study is the induced formation of streamers (thin current filaments with radius of the order of several hundreds of μm) and spark in steady-state positive corona. It is well known, there are three main current modes (1-diffusive Hermstein glow, 2-streamers, 3-spark) for a centimeters gap positive pin-plane corona in ambient air, which follow in that order with increase of applied voltage. It is common, a critical value of corona current for 1→2-transition equals to 50-70 μA. Streamers start from a tip of pin towards the plane. Streamer mode is characterized by almost periodical splashes in current. In general, both the frequency of streamer occurrence and amplitude of current splashes increase with average corona current from units to tens of kHz and from tens to hundreds of mA, respectively. If the average corona current is in excess of some value, streamers (more precisely, streamer trains) induce periodically the sparks. A quantity of streamers in train inducing a single spark (2→3-transition) is diminished with increase in average corona current

  2. PLUG-IN HYBRID ELECTRIC VEHICLE AND HYBRID ELECTRIC VEHICLE EMISSIONS UNDER FTP AND US06 CYCLES AT HIGH, AMBIENT, AND LOW TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    Seidman, M.R.; Markel, T.

    2008-01-01

    The concept of a Plug-in Hybrid Electric Vehicle (PHEV) is to displace consumption of gasoline by using electricity from the vehicle’s large battery pack to power the vehicle as much as possible with minimal engine operation. This paper assesses the PHEV emissions and operation. Currently, testing of vehicle emissions is done using the federal standard FTP4 cycle on a dynamometer at ambient (75°F) temperatures. Research was also completed using the US06 cycle. Furthermore, research was completed at high (95°F) and low (20°F) temperatures. Initial dynamometer testing was performed on a stock Toyota Prius under the standard FTP4 cycle, and the more demanding US06 cycle. Each cycle was run at 95°F, 75°F, and 20°F. The testing was repeated with the same Prius retrofi tted with an EnergyCS Plug-in Hybrid Electric system. The results of the testing confi rm that the stock Prius meets Super-Ultra Low Emission Vehicle requirements under current testing procedures, while the PHEV Prius under current testing procedures were greater than Super-Ultra Low Emission Vehicle requirements, but still met Ultra Low Emission Vehicle requirements. Research points to the catalyst temperature being a critical factor in meeting emission requirements. Initial engine emissions pass through with minimal conversion until the catalyst is heated to typical operating temperatures of 300–400°C. PHEVs also have trouble maintaining the minimum catalyst temperature throughout the entire test because the engine is turned off when the battery can support the load. It has been observed in both HEVs and PHEVs that the catalyst is intermittently unable to reduce nitrogen oxide emissions, which causes further emission releases. Research needs to be done to combat the initial emission spikes caused by a cold catalyst. Research also needs to be done to improve the reduction of nitrogen oxides by the catalyst system.

  3. Enhancing Food Processing by Pulsed and High Voltage Electric Fields: Principles and Applications.

    Science.gov (United States)

    Wang, Qijun; Li, Yifei; Sun, Da-Wen; Zhu, Zhiwei

    2018-02-02

    Improvements in living standards result in a growing demand for food with high quality attributes including freshness, nutrition and safety. However, current industrial processing methods rely on traditional thermal and chemical methods, such as sterilization and solvent extraction, which could induce negative effects on food quality and safety. The electric fields (EFs) involving pulsed electric fields (PEFs) and high voltage electric fields (HVEFs) have been studied and developed for assisting and enhancing various food processes. In this review, the principles and applications of pulsed and high voltage electric fields are described in details for a range of food processes, including microbial inactivation, component extraction, and winemaking, thawing and drying, freezing and enzymatic inactivation. Moreover, the advantages and limitations of electric field related technologies are discussed to foresee future developments in the food industry. This review demonstrates that electric field technology has a great potential to enhance food processing by supplementing or replacing the conventional methods employed in different food manufacturing processes. Successful industrial applications of electric field treatments have been achieved in some areas such as microbial inactivation and extraction. However, investigations of HVEFs are still in an early stage and translating the technology into industrial applications need further research efforts.

  4. Novel high power impulse magnetron sputtering enhanced by an auxiliary electrical field

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chunwei, E-mail: lcwnefu@126.com, E-mail: xiubotian@163.com [College of Engineering and Technology, Northeast Forestry University, Harbin 150040 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Tian, Xiubo, E-mail: lcwnefu@126.com, E-mail: xiubotian@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2016-08-15

    The high power impulse magnetron sputtering (HIPIMS) technique is a novel highly ionized physical vapor deposition method with a high application potential. However, the electron utilization efficiency during sputtering is rather low and the metal particle ionization rate needs to be considerably improved to allow for a large-scale industrial application. Therefore, we enhanced the HIPIMS technique by simultaneously applying an electric field (EF-HIPIMS). The effect of the electric field on the discharge process was studied using a current sensor and an optical emission spectrometer. Furthermore, the spatial distribution of the electric potential and electric field during the EF-HIPIMS process was simulated using the ANSYS software. The results indicate that a higher electron utilization efficiency and a higher particle ionization rate could be achieved. The auxiliary anode obviously changed the distribution of the electric potential and the electric field in the discharge region, which increased the plasma density and enhanced the degree of ionization of the vanadium and argon gas. Vanadium films were deposited to further compare both techniques, and the morphology of the prepared films was investigated by scanning electron microscopy. The films showed a smaller crystal grain size and a denser growth structure when the electric field was applied during the discharge process.

  5. High Torque, Direct Drive Electric Motor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Bear Engineering proposes to advance the development of an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such...

  6. High Temperature Radiators for Electric Propulsion Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The VASIMR propulsion system uses a high temperature Loop Heat Pipe (LHP) radiator to reject heat from the helicon section. The current baseline radiator uses...

  7. High Torque, Direct Drive Electric Motor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Bear Engineering proposes to develop an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such devices. Fundamentally,...

  8. Motivation, Critical Thinking and Academic Verification of High School Students' Information-seeking Behavior

    Directory of Open Access Journals (Sweden)

    Z Hidayat

    2017-06-01

    Full Text Available High school students have known as Gen Y or Z and their media using can be understand on their information-seeking behavior. This research’s purposes were: 1 to analyze the students’ motivation; 2 to analyze the critical thinking and academic verification; 3 to analyze the information-seeking behavior. This study used quantitative approach through survey among 1125 respondents in nine clusters, i.e. Central, East, North, West, and South of Jakarta, Tangerang, Bekasi, Depok, and Bogor. Schools sampling based on "the best schools rank" by the government, while respondents have taken by accidental in each school. Construct of questionnaire included measurement of motivation, critical thinking and academic verification, and the information-seeking behavior at all. The results showed that the motivations of the use of Internet were dominated by habit to interact and be entertained while on the academic needs are still relatively small but increasing significantly. Students’ self-efficacy, performance and achievement goals tend to be high motives, however the science learning value, and learning environment stimulation were average low motives. High school students indicated that they think critically about the various things that become content primarily in social media but less critical of the academic information subjects. Unfortunately, high school students did not conducted academic verification on the data and information but students tend to do plagiarism. Key words: Student motivation, critical thinking, academic verification, information-seeking behavior, digital generation.

  9. Challenges and Opportunities of Very Light High-Performance Electric Drives for Aviation

    Directory of Open Access Journals (Sweden)

    Markus Henke

    2018-02-01

    Full Text Available The demand for alternative fueling methods to reduce the need for fossil fuels is not limited to the electrification of ground vehicles. More-electric and all-electric aircraft pose challenges, with extensive requirements in terms of power density, efficiency, safety, and environmental sustainability. This paper focuses on electrical machines and their components, especially for high-power applications like the main propulsion. The electrical machine is evaluated from different aspects, followed by a closer look at the components and materials to determine the suitability of the current standard materials and advanced technologies. Furthermore, the mechanical and thermal aspects are reviewed, including new and innovative concepts for the cooling of windings and for the use of additive manufacturing. Aircraft have special demands regarding weight and installation space. Following recent developments and looking ahead to the future, the need and the possibilities for light and efficient electrical machines are addressed. All of the approaches and developments presented lead to a better understanding of the challenges to be expected and highlight the upcoming opportunities in electrical machine design for the use of electric motors and generators in future aircraft. Several prototypes of electrical machines for smaller aircraft already exist, such as the electric drive of the Siemens powered Extra 330LE. The focus of this paper is to provide an overview of current technical possibilities and technical interrelations of high performance electric drives for aviation. A 1 MW drive is exemplified to present the possibilities for future drives for airplanes carrying a larger number of passengers. All presented techniques can also be applied to other drive power classes.

  10. A statistical study of high-altitude electric fields measured on the Viking satellite

    International Nuclear Information System (INIS)

    Lindqvist, P.A.; Marklund, G.T.

    1990-01-01

    Characteristics of high-altitude data from the Viking electric field instrument are presented in a statistical study based on 109 Viking orbits. The study is focused in particular on the signatures of and relationships between various parameters measured by the electric field instrument, such as the parallel and transverse (to B) components of the electric field instrument, such as electric field variability. A major goal of the Viking mission was to investigate the occurrence and properties of parallel electric fields and their role in the auroral acceleration process. The results in this paper on the altitude distribution of the electric field variability confirm earlier findings on the distribution of small-scale electric fields and indicate the presence of parallel fields up to about 11,000 km altitude. The directly measured parallel electric field is also investigated in some detail. It is in general directed upward with an average value of 1 mV/m, but depends on, for example, altitude and plasma density. Possible sources of error in the measurement of the parallel field are also considered and accounted for

  11. Critical Heat Flux Phenomena at HighPressure & Low Mass Fluxes: NEUP Final Report Part I: Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States); Wu, Qiao [Oregon State Univ., Corvallis, OR (United States)

    2015-04-30

    This report is a preliminary document presenting an overview of the Critical Heat Flux (CHF) phenomenon, the High Pressure Critical Heat Flux facility (HPCHF), preliminary CHF data acquired, and the future direction of the research. The HPCHF facility has been designed and built to study CHF at high pressure and low mass flux ranges in a rod bundle prototypical of conceptual Small Modular Reactor (SMR) designs. The rod bundle is comprised of four electrically heated rods in a 2x2 square rod bundle with a prototypic chopped-cosine axial power profile and equipped with thermocouples at various axial and circumferential positions embedded in each rod for CHF detection. Experimental test parameters for CHF detection range from pressures of ~80 – 160 bar, mass fluxes of ~400 – 1500 kg/m2s, and inlet water subcooling from ~30 – 70°C. The preliminary data base established will be further extended in the future along with comparisons to existing CHF correlations, models, etc. whose application ranges may be applicable to the conditions of SMRs.

  12. High Current Density Electrical Breakdown of TiS

    NARCIS (Netherlands)

    Molina-Mendoza, Aday J.; Island, J.O.; Paz, Wendel S.; Clamagirand, Jose Manuel; Ares, Josè Ramon; Flores, Eduardo; Leardini, Fabrice; Sánchez, Carlos; Agraït, Nicolás; Rubio-Bollinger, Gabino; van der Zant, H.S.J.; Ferrer, Isabel J.; Palacios, JJ; Castellanos-Gomez, Andres

    2017-01-01

    The high field transport characteristics of nanostructured transistors based on layered materials are not only important from a device physics perspective but also for possible applications in next generation electronics. With the growing promise of layered materials as replacements to

  13. High voltage transmission of electrical energy over long distances

    Energy Technology Data Exchange (ETDEWEB)

    Tewari, S W

    1962-07-01

    Technical aspects of ac transmission lines, additional means of improving stability ac transmisson lines, insulation problems, ac transmission by cables, high voltage dc transmission, advantages of dc over ac transmission, disadvantages of dc transmission, use of underground cables for dc transmission, history of the development of conversion equipment; transmission schemes adopted on Gotland Island, Sweden; and economics of ac and dc transmission are discussed.

  14. Process Characterization of Electrical Discharge Machining of Highly Doped Silicon

    Science.gov (United States)

    2012-06-01

    of mechanism is shown in Figure 2 showing the wire feed panel where the spool of 5 (DiBitonto, et...Uno High efficiency boring of monocrystalline silicon ingot by EDM RAM Si (P-type) conductivity 0.01 ohm-cm 1mm Cu pipe electrode, rotating at

  15. High penetration wind generation impacts on spot prices in the Australian national electricity market

    International Nuclear Information System (INIS)

    Cutler, Nicholas J.; Boerema, Nicholas D.; MacGill, Iain F.; Outhred, Hugh R.

    2011-01-01

    This paper explores wind power integration issues for the South Australian (SA) region of the Australian National Electricity Market (NEM) by assessing the interaction of regional wind generation, electricity demand and spot prices over 2 recent years of market operation. SA's wind energy penetration has recently surpassed 20% and it has only a limited interconnection with other regions of the NEM. As such, it represents an interesting example of high wind penetration in a gross wholesale pool market electricity industry. Our findings suggest that while electricity demand continues to have the greatest influence on spot prices in SA, wind generation levels have become a significant secondary influence, and there is an inverse relationship between wind generation and price. No clear relationship between wind generation and demand has been identified although some periods of extremely high demand may coincide with lower wind generation. Periods of high wind output are associated with generally lower market prices, and also appear to contribute to extreme negative price events. The results highlight the importance of electricity market and renewable policy design in facilitating economically efficient high wind penetrations. - Highlights: → In South Australia (SA) wind generation is having an influence on market prices. → Little or no correlation is found between wind generation and demand. → Wind farms in SA are receiving a lower average price than in other States. → The results highlight the importance of appropriate electricity market design.

  16. In-channel electrochemical detection in the middle of microchannel under high electric field.

    Science.gov (United States)

    Kang, Chung Mu; Joo, Segyeong; Bae, Je Hyun; Kim, Yang-Rae; Kim, Yongseong; Chung, Taek Dong

    2012-01-17

    We propose a new method for performing in-channel electrochemical detection under a high electric field using a polyelectrolytic gel salt bridge (PGSB) integrated in the middle of the electrophoretic separation channel. The finely tuned placement of a gold working electrode and the PGSB on an equipotential surface in the microchannel provided highly sensitive electrochemical detection without any deterioration in the separation efficiency or interference of the applied electric field. To assess the working principle, the open circuit potentials between gold working electrodes and the reference electrode at varying distances were measured in the microchannel under electrophoretic fields using an electrically isolated potentiostat. In addition, "in-channel" cyclic voltammetry confirmed the feasibility of electrochemical detection under various strengths of electric fields (∼400 V/cm). Effective separation on a microchip equipped with a PGSB under high electric fields was demonstrated for the electrochemical detection of biological compounds such as dopamine and catechol. The proposed "in-channel" electrochemical detection under a high electric field enables wider electrochemical detection applications in microchip electrophoresis.

  17. Electrical properties of single crystal Yttrium Iron Garnet ultra-thin films at high temperatures

    OpenAIRE

    Thiery, Nicolas; Naletov, Vladimir V.; Vila, Laurent; Marty, Alain; Brenac, Ariel; Jacquot, Jean-François; de Loubens, Grégoire; Viret, Michel; Anane, Abdelmadjid; Cros, Vincent; Youssef, Jamal Ben; Demidov, Vladislav E.; Demokritov, Sergej O.; Klein, Olivier

    2017-01-01

    We report a study on the electrical properties of 19 nm thick Yttrium Iron Garnet (YIG) films grown by liquid phase epitaxy. The electrical conductivity and Hall coefficient are measured in the high temperature range [300,400]~K using a Van der Pauw four-point probe technique. We find that the electrical resistivity decreases exponentially with increasing temperature following an activated behavior corresponding to a band-gap of $E_g\\approx 2$ eV, indicating that epitaxial YIG ultra-thin film...

  18. High energy KrCl electric discharge laser

    Science.gov (United States)

    Sze, Robert C.; Scott, Peter B.

    1981-01-01

    A high energy KrCl laser for producing coherent radiation at 222 nm. Output energies on the order of 100 mJ per pulse are produced utilizing a discharge excitation source to minimize formation of molecular ions, thereby minimizing absorption of laser radiation by the active medium. Additionally, HCl is used as a halogen donor which undergoes a harpooning reaction with metastable Kr.sub.M * to form KrCl.

  19. Superconductor Armature Winding for High Performance Electrical Machines

    Science.gov (United States)

    2016-12-05

    eddy -induced currents used for shielding. 3.1 SOLID SHIELD. The frequency of the induced current for our machines ... eddy   current  shields)   •  SuperSat     •  switch  reluctance  generators   •  AC  Homopolar   • Toroidal  (Gramme...higher than expected, due probably to highly conducting Nb sheath around the MgB2 filaments (the measured losses were coupling or eddy current

  20. Electrical insulation characteristics of liquid helium under high speed rotating field

    International Nuclear Information System (INIS)

    Ishii, I.; Fuchino, S.; Okano, M.; Tamada, N.

    1996-01-01

    Electrical breakdown behavior of liquid helium was investigated under high speed rotating field. In the development of superconducting turbine generator it is essential to get the knowledge of electrical insulation characteristics of liquid helium under high speed rotating field. When the current of the field magnet of a superconducting generator is changed, changing magnetic field generates heat in the conductor and it causes bubbles in the liquid helium around the conductor. The behavior of the bubbles is affected largely by the buoyancy which is generated by the centrifugal force. Electrical breakdown behavior of the liquid helium is strongly dependent on the gas bubbles in the liquid. Electrical breakdown voltage between electrodes was measured in a rotating cryostat with and without heater input for bubble formation. Decrease of the breakdown voltage by the heater power was smaller in the rotating field than that in the non rotating field

  1. The Architecture Design of Detection and Calibration System for High-voltage Electrical Equipment

    Science.gov (United States)

    Ma, Y.; Lin, Y.; Yang, Y.; Gu, Ch; Yang, F.; Zou, L. D.

    2018-01-01

    With the construction of Material Quality Inspection Center of Shandong electric power company, Electric Power Research Institute takes on more jobs on quality analysis and laboratory calibration for high-voltage electrical equipment, and informationization construction becomes urgent. In the paper we design a consolidated system, which implements the electronic management and online automation process for material sampling, test apparatus detection and field test. In the three jobs we use QR code scanning, online Word editing and electronic signature. These techniques simplify the complex process of warehouse management and testing report transferring, and largely reduce the manual procedure. The construction of the standardized detection information platform realizes the integrated management of high-voltage electrical equipment from their networking, running to periodic detection. According to system operation evaluation, the speed of transferring report is doubled, and querying data is also easier and faster.

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

    International Nuclear Information System (INIS)

    Kucukozer, H.

    2005-01-01

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

  3. Organic superconductors with high transition temperatures and high critical magnetic fields

    International Nuclear Information System (INIS)

    Wolf, A.A.; Halpern, E.H.

    1976-01-01

    Organic compounds exhibit superconducting-like behavior, as to magnetic and electrical properties, at elevated temperatures above 21 0 K, where 21 0 K is the transition temperature of most known metallic superconducting materials. The structure of the organic materials according to this invention is a plurality of superconducting clusters, forming islands within a matrix of insulating material. The ratio of the clusters to the matrix material is a minimum at 1 : 10 4 . The organic compound comprises two distinct atomic groups termed an R group and COOM group combining as R-COOM with the COOM group clustering to form superconducting islands, within the R material matrix. 15 claims, 6 figures

  4. Critical analysis of the proposition of reduction of the nuclear share to 50% of the electric mix by 2025

    International Nuclear Information System (INIS)

    2011-01-01

    This paper briefly comments different evolution options regarding the French electric mix (replacement of nuclear plants by natural gas plants, maximum development of photovoltaic and wind energy, drastic reduction of electricity consumption) and of their consequences in terms of CO 2 emissions. As none of these options is acceptable with respect to climatic and economic requirements, another option is proposed: keeping the nuclear at its current level, increasing electricity production by means of natural gas plants, and increasing heat production. The benefits of this solution are briefly outlined

  5. Electrical conductivity of molten CdCl{sub 2} at temperatures as high as 1474 K

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, Alexander B.; Potapov, Alexei M. [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of High-Temperature Electrochemistry

    2016-11-01

    The electrical conductivity of molten CdCl{sub 2} was measured across a wide temperature range (ΔT=628 K), from 846 K to as high as 1474 K, i.e. 241 above the normal boiling point of the salt. In previous studies, a maximum temperature of 1201 K was reached, this being 273 lower than in the present work. The activation energy of electrical conductivity was calculated.

  6. Highly-Efficient Thermoelectronic Conversion of Heat and Solar Radiation to Electric Power

    OpenAIRE

    Meir, Stefan

    2013-01-01

    Thermionic energy conversion has long been a candidate to convert solar radiation and the combustion heat of fossil fuels into electricity at high efficiencies. However, the formation of electron space charges has prevented the widespread use of the principle since its was first suggested in 1915. In this work, a novel mechanism to suppress the effects of the space charge was investigated: the acceleration of electrons in a special configuration of electric and magnetic fields. This work d...

  7. Graphene-based sample supports for in situ high-resolution TEM electrical investigations

    International Nuclear Information System (INIS)

    Westenfelder, B; Scholz, F; Meyer, J C; Biskupek, J; Algara-Siller, G; Lechner, L G; Kaiser, U; Kusterer, J; Kohn, E; Krill, C E III

    2011-01-01

    Specially designed transmission electron microscopy (TEM) sample carriers have been developed to enable atomically resolved studies of the heat-induced evolution of adsorbates on graphene and their influence on electrical conductivity. Here, we present a strategy for graphene-based carrier realization, evaluating its design with respect to fabrication effort and applications potential. We demonstrate that electrical current can lead to very high temperatures in suspended graphene membranes, and we determine that current-induced cleaning of graphene results from Joule heating.

  8. High efficiency thermal to electric energy conversion using selective emitters and spectrally tuned solar cells

    Science.gov (United States)

    Chubb, Donald L.; Flood, Dennis J.; Lowe, Roland A.

    1992-01-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1500 K. Depending on the nature of parasitic losses, overall thermal-to-electric conversion efficiencies greater than 20 percent are feasible.

  9. Electrical conductivity of molten CdCl2 at temperatures as high as 1474 K

    International Nuclear Information System (INIS)

    Salyulev, Alexander B.; Potapov, Alexei M.

    2016-01-01

    The electrical conductivity of molten CdCl 2 was measured across a wide temperature range (ΔT=628 K), from 846 K to as high as 1474 K, i.e. 241 above the normal boiling point of the salt. In previous studies, a maximum temperature of 1201 K was reached, this being 273 lower than in the present work. The activation energy of electrical conductivity was calculated.

  10. High-voltage electrical burns due to copper theft - Case series.

    Science.gov (United States)

    Braga, M J; Oliveira, I; Egipto, P; Silva, A

    2016-03-31

    Electrical burns are among the most devastating trauma inflicted on the human body. These burns have a higher morbidity, length of stay and a much higher risk of amputation than any other type of burn. Electrical burns affect mostly young, working males because they are more frequently the result of a work accident. However, possibly due to the worldwide economic crisis, we are experiencing a new phenomenon: the theft of high-voltage copper wiring.

  11. High-voltage electrical burns due to copper theft – Case series

    Science.gov (United States)

    Braga, M.J.; Oliveira, I.; Egipto, P.; Silva, A.

    2016-01-01

    Summary Electrical burns are among the most devastating trauma inflicted on the human body. These burns have a higher morbidity, length of stay and a much higher risk of amputation than any other type of burn. Electrical burns affect mostly young, working males because they are more frequently the result of a work accident. However, possibly due to the worldwide economic crisis, we are experiencing a new phenomenon: the theft of high-voltage copper wiring. PMID:27857650

  12. Structural health monitoring of high voltage electrical switch ceramic insulators in seismic areas

    OpenAIRE

    REBILLAT, Marc; BARTHES, Clément; MECHBAL, Nazih; MOSALAM, Khalid M.

    2014-01-01

    International audience; High voltage electrical switches are crucial components to restart rapidly the electrical network right after an earthquake. But there currently exists no automatic procedure to check if these ceramic insulators have suffered after an earthquake, and there exists no method to recertify a given switch. To deploy a vibration-based structural health monitoring method on ceramic insulators a large shake table able to generate accelerations up to 3 g was used. The idea unde...

  13. ENEL high and medium voltage electrical substations for power supply to urban centers

    International Nuclear Information System (INIS)

    Bargigia, A.; Boatto, C.; Di Mario, A.; Fava, N.; Sciarra, S.; Speziali, R.

    1991-12-01

    Modular high and medium voltage gas insulated electrical substations are being used by ENEL (Italian Electricity Board) to meet the specific needs of urban centers with special design and sizing constraints of a historical/architectural nature. This paper illustrates the key design, construction operation and performance characteristics of these standardized units. The descriptions include brief notes on equipment-transformer interconnection, interchangeability and environmental compatibility. Performance test procedures and results of actual reliability and certification tests on some substations are reported

  14. Critical currents and superconductivity ferromagnetism coexistence in high-Tc oxides

    CERN Document Server

    Khene, Samir

    2016-01-01

    The book comprises six chapters which deal with the critical currents and the ferromagnetism-superconductivity coexistence in high-Tc oxides. It begins by gathering key data for superconducting state and the fundamental properties of the conventional superconductors, followed by a recap of the basic theories of superconductivity. It then discusses the differences introduced by the structural anisotropy on the Ginzburg-Landau approach and the Lawrence-Doniach model before addressing the dynamics of vortices and the ferromagnetism-superconductivity coexistence in high-Tc oxides, and provides an outline of the pinning phenomena of vortices in these materials, in particular the pinning of vortices by the spins. It elucidates the methods to improve the properties of superconducting materials for industrial applications. This optimization aims at obtaining critical temperatures and densities of critical currents at the maximum level possible. Whereas the primary objective is the basic mechanisms pushing the superco...

  15. Heat pumps; Synergy of high efficiency and low carbon electricity

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Akio

    2010-09-15

    Heat pump is attracting wide attention for its high efficiency to utilize inexhaustible and renewable ambient heat in the environment. With its rapid innovation and efficiency improvement, this technology has a huge potential to reduce CO2 emissions by replacing currently widespread fossil fuel combustion systems to meet various heat demands from the residential, commercial and industrial sectors. Barriers to deployment such as low public awareness and a relatively long pay-back period do exist, so it is strongly recommended that each country implement policies to promote heat pumps as a renewable energy option and an effective method to combat global warming.

  16. Electrical measuring device for a high temperature reactor

    International Nuclear Information System (INIS)

    Elter, C.; Handel, H.; Schoening, J.; Schmitt, H.

    1982-01-01

    The device for measuring the low or high neutron flux during start-up or at load is accommodated in an armoured guide tube projecting into the floor. A gas-tight capsule is formed as the measuring column with outer dome with a lid solidly connected by a flange to the armoured tube situated on the side wall of the concrete reactor vessel, together with the armoured guide tube. Two shielding shutters prevent the passage of radiation through the armoured tube. (DG) [de

  17. High-Voltage Solid Polymer Batteries for Electric Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Eitouni, Hany; Yang, Jin; Pratt, Russell; Wang, Xiao; Grape, Ulrik

    2014-09-29

    The purpose of this project was for Seeo to develop a high energy lithium based technology with targets of over 500 Wh/l and 325 Wh/kg. Seeo would leverage the work already achieved with its unique proprietary solid polymer DryLyteTM technology in cells which had a specific energy density of 220 Wh/kg. The development work was focused on establishing a dual electrolyte system, coated cathode particle techniques, various types of additives, and different conductive salts. The program had a duration of three years, with Seeo delivering the final cells at the end of 2014 for evaluation by a DOE laboratory.

  18. Vortex lines in layered superconductors. II. Pinning and critical currents in high temperature superconductors

    Science.gov (United States)

    Manuel, P.

    1994-02-01

    In this article, a qualitative survey is given on the various phenomena which influence the critical current of high temperature superconductors. Critical current is defined as a property related to a non-zero electric field criterion, the level of which is fixed by experimental considerations, or efficiency requirements of applications. The presentation is restricted to extrinsic intragranular critical current, which depends in a complex way on the interplay between the characteristics of pinning centres and the properties of the vortex lattice. The discussion is focussed on the configuration {B} / / {c}, which contains the main elements of this problem. Differences of behaviour between Y(123) and BSCCO (Bi(2212) or Bi(2223)) are analysed in the context of their respective anisotropy factors. Possible regimes for pinning and creep are discussed in various temperature domains. From critical current results, a strong pinning regime is found to occur in BSCCO, whereas the pinning strength in Y(123) is still an open question. The thermal decrease of critical current allows a collective creep regime to appear in both materials, but at different temperature ranges. The disappearance of correlation effects near the irreversibility line results in a fall of the effective pinning energy. We show that in BSCCO, the effective pinning energy deduced from experimental results is not in agreement with pinning by randomly dispersed oxygen vacancies. Finally, we shortly describe the microstructures which could allow a more efficient pinning in future materials. On effectue une présentation qualitative des divers phénomènes qui contrôlent la valeur du courant critique dans les supraconducteurs à haute température. La notion de courant critique qui est utilisée est reliée à un critère de champ électrique non nul, fixé par des considérations expérimentales ou des exigences de rendement pour les applications. On se restreint au problème des courants critiques

  19. Improving Junior High Schools’ Critical Thinking Skills Based on Test Three Different Models of Learning

    Directory of Open Access Journals (Sweden)

    Nur Miftahul Fuad

    2017-01-01

    Full Text Available The aims of this study were (1 to find out the differences in critical thinking skills among students who were given three different learning models: differentiated science inquiry combined with mind map, differentiated science inquiry model, and conventional model, (2 to find out the differences of critical thinking skills among male and female students. This study is a quasi-experimental research with pretest-posttest nonequivalent control group design. The population in this research is the seventh grade students of junior high schools in Kediri, Indonesia. The sample of the research is in the number of 96 students distributed in three classes at different schools. The data of critical thinking skills are gained from test scores and then analyzed using descriptive and inferential statistics through ANCOVA. The results of research revealed that there are different skills in critical thinking in different models. The highest skills in critical thinking are reached by students who were given differentiated science inquiry model combined with mind map in their learning. There are also differences in critical thinking skills between male and female students.

  20. Critical Thinking Skills Of Junior High School Female Students With High Mathematical Skills In Solving Contextual And Formal Mathematical Problems

    Science.gov (United States)

    Ismail; Suwarsono, St.; Lukito, A.

    2018-01-01

    Critical thinking is one of the most important skills of the 21st century in addition to other learning skills such as creative thinking, communication skills and collaborative skills. This is what makes researchers feel the need to conduct research on critical thinking skills in junior high school students. The purpose of this study is to describe the critical thinking skills of junior high school female students with high mathematical skills in solving contextual and formal mathematical problems. To achieve this is used qualitative research. The subject of the study was a female student of eight grade junior high school. The students’ critical thinking skills are derived from in-depth problem-based interviews using interview guidelines. Interviews conducted in this study are problem-based interviews, which are done by the subject given a written assignment and given time to complete. The results show that critical thinking skills of female high school students with high math skills are as follows: In solving the problem at the stage of understanding the problem used interpretation skills with sub-indicators: categorization, decode, and clarify meaning. At the planning stage of the problem-solving strategy is used analytical skills with sub-indicators: idea checking, argument identification and argument analysis and evaluation skills with sub indicators: assessing the argument. In the implementation phase of problem solving, inference skills are used with subindicators: drawing conclusions, and problem solving and explanatory skills with sub-indicators: problem presentation, justification procedures, and argument articulation. At the re-checking stage all steps have been employed self-regulatory skills with sub-indicators: self-correction and selfstudy.

  1. Electrical spin injection into high mobility 2D systems.

    Science.gov (United States)

    Oltscher, M; Ciorga, M; Utz, M; Schuh, D; Bougeard, D; Weiss, D

    2014-12-05

    We report on spin injection into a high mobility 2D electron system confined at an (Al,Ga)As/GaAs interface, using (Ga,Mn)As Esaki diode contacts as spin aligners. We measured a clear nonlocal spin valve signal, which varies nonmonotonically with the applied bias voltage. The magnitude of the signal cannot be described by the standard spin drift-diffusion model, because at maximum this would require the spin polarization of the injected current to be much larger than 100%, which is unphysical. A strong correlation of the spin signal with contact width and electron mean free path suggests that ballistic transport in the 2D region below ferromagnetic contacts should be taken into account to fully describe the results.

  2. Dossier high-efficient electric water heater. Electricity by a Stirling engine; Het Dossier HRE-ketel. Stroom uit Stirlingmotor

    Energy Technology Data Exchange (ETDEWEB)

    Scholtens, B.

    2010-10-15

    The market seems ready for a private power plant on the wall in the attic, which also heats the house. Such an installation is the successor of the high efficiency boiler, which is in use in most of the homes in the Netherlands. After fifteen years of development Dutch companies have taken the lead in this technology. The manufacturer Remeha in Apeldoorn, Netherlands, started one month ago with the production of high efficiency electric boiler. [Dutch] De markt lijkt klaar voor een eigen stroomcentrale aan de muur op zolder die bovendien het huis verwarmt. De installatie is de opvolger van de hoogrendementsketel, die de meeste huizen in Nederland verwarmt. Na vijftien jaar ontwikkeling hebben Nederlandse bedrijven het technologische voortouw genomen. De Apeldoornse fabrikant Remeha is een maand geleden als eerste met serieproductie van de hre-ketel begonnen.

  3. High Concentration of Heat Pumps in Suburban Areas and Reduction of Their Impact on the Electricity Network

    NARCIS (Netherlands)

    Pruissen, O.P. van; Kamphuis, I.G.

    2011-01-01

    One of the challenges of the near future for a more renewable Dutch electricity infrastructure is the embedding of high concentrations of heat pumps in currently built domestic residences. In the Dutch situation demand of electricity occurs simultaneously with demand of heat, high electricity peak

  4. Microstructure and critical current density in high-Tc metal oxide superconductors

    International Nuclear Information System (INIS)

    Johnson, S.M.; Gusman, M.I.

    1992-03-01

    Superconductor powders in the U-Ba-Cu-O (YBCO) and Bi-Pb-Sr-Ca-Cu-O (BSCCO) systems were synthesized by freeze-drying. Powders were characterized, and processed into samples for evaluation of superconducting behavior. Freeze-drying is attractive because the powders have high purity, are homogeneous, have a small size and are active. YBCO powders can be sintered to high density at 890 degrees C. Many compositions, processing approaches and heat treatments were explored in an effort to understand relations between microstructure and critical density, and to improve the critical current density. Powders were also formed into sputtering targets for coating preparation at Stanford University. The highest critical current density achieved with the YBCO powders was ∼15,000 A/cm 2 at 4.2K and 0.5T using powders treated to prevent carbon contamination. The BSCCO materials with the highest critical current density, ∼30,000 A/cm 2 at the same conditions were formed by heat treating melted and quenched samples. All critical current density measurements were made by Stanford University, a subcontractor to this effort. Stanford University also prepared coatings by off-axis magnetron sputtering

  5. Optimal Operation of Plug-In Electric Vehicles in Power Systems with High Wind Power Penetrations

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Chen, Zhe

    2013-01-01

    in the power systems with high wind power penetrations. In this paper, the integration of plug-in electric vehicles in the power systems with high wind power penetrations is proposed and discussed. Optimal operation strategies of PEV in the spot market are proposed in order to decrease the energy cost for PEV......The Danish power system has a large penetration of wind power. The wind fluctuation causes a high variation in the power generation, which must be balanced by other sources. The battery storage based Plug-In Electric Vehicles (PEV) may be a possible solution to balance the wind power variations...... owners. Furthermore, the application of battery storage based aggregated PEV is analyzed as a regulation services provider in the power system with high wind power penetrations. The western Danish power system where the total share of annual wind power production is more than 27% of the electrical energy...

  6. The evolution of legal aspects on the Brazilian electric power sector, a critical analysis; Evolucao dos marcos regulatorios do mercado de energia eletrica no Brasil, uma analise critica

    Energy Technology Data Exchange (ETDEWEB)

    Bastos, Adriano Silva

    2007-07-01

    The electric sector went through deep changes along these 125 years of electrification of the country, mainly the alternation of their investment bases, hour being private for the most part, state hour. The legal bases of concession and regulation also varied in this period, trying to adapt to the effective model of the time. This work intends to analyze the evolution of the regulatory models of the electric sector, identifying the main changes of paradigms and to compare the efficiency of the models already implanted in the segment, with views to the increment of the offer of energy in the period, molding a critical profile of the best model already adopted in the national electric sector. To compare qualitatively these models requests an analysis of the investment bases a priori in the sector, identifying the contribution of resources has been private or state, following by the government's legal positioning in the sense of being only regulator, or regulator and investor, concluding with an analysis of the electric power offer in the period and the power of self-financing of the companies, in order to assent that the mixed model is the most appropriate model for the sustainable growth of the electric power generation sector in Brazil. (author)

  7. The evolution of legal aspects on the Brazilian electric power sector, a critical analysis; Evolucao dos marcos regulatorios do mercado de energia eletrica no Brasil, uma analise critica

    Energy Technology Data Exchange (ETDEWEB)

    Bastos, Adriano Silva

    2007-07-01

    The electric sector went through deep changes along these 125 years of electrification of the country, mainly the alternation of their investment bases, hour being private for the most part, state hour. The legal bases of concession and regulation also varied in this period, trying to adapt to the effective model of the time. This work intends to analyze the evolution of the regulatory models of the electric sector, identifying the main changes of paradigms and to compare the efficiency of the models already implanted in the segment, with views to the increment of the offer of energy in the period, molding a critical profile of the best model already adopted in the national electric sector. To compare qualitatively these models requests an analysis of the investment bases a priori in the sector, identifying the contribution of resources has been private or state, following by the government's legal positioning in the sense of being only regulator, or regulator and investor, concluding with an analysis of the electric power offer in the period and the power of self-financing of the companies, in order to assent that the mixed model is the most appropriate model for the sustainable growth of the electric power generation sector in Brazil. (author)

  8. Multi-step ahead forecasts for electricity prices using NARX: A new approach, a critical analysis of one-step ahead forecasts

    International Nuclear Information System (INIS)

    Andalib, Arash; Atry, Farid

    2009-01-01

    The prediction of electricity prices is very important to participants of deregulated markets. Among many properties, a successful prediction tool should be able to capture long-term dependencies in market's historical data. A nonlinear autoregressive model with exogenous inputs (NARX) has proven to enjoy a superior performance to capture such dependencies than other learning machines. However, it is not examined for electricity price forecasting so far. In this paper, we have employed a NARX network for forecasting electricity prices. Our prediction model is then compared with two currently used methods, namely the multivariate adaptive regression splines (MARS) and wavelet neural network. All the models are built on the reconstructed state space of market's historical data, which either improves the results or decreases the complexity of learning algorithms. Here, we also criticize the one-step ahead forecasts for electricity price that may suffer a one-term delay and we explain why the mean square error criterion does not guarantee a functional prediction result in this case. To tackle the problem, we pursue multi-step ahead predictions. Results for the Ontario electricity market are presented

  9. Critical Race Theory, Hip Hop, and "Huck Finn": Narrative Inquiry in a High School English Classroom

    Science.gov (United States)

    Martin, Jennifer L.

    2014-01-01

    This study explores the impact of reading "Huckleberry Finn" through the lens of critical race theory for both teacher and students in a racially diverse urban high school environment. The teacher/researcher used narrative inquiry and creative non-fiction to examine student language usage, white privilege (including her own), and student…

  10. Critical Factors Explaining the Leadership Performance of High-Performing Principals

    Science.gov (United States)

    Hutton, Disraeli M.

    2018-01-01

    The study explored critical factors that explain leadership performance of high-performing principals and examined the relationship between these factors based on the ratings of school constituents in the public school system. The principal component analysis with the use of Varimax Rotation revealed that four components explain 51.1% of the…

  11. Boundary conditions in Ginsburg Landau theory and critical temperature of high-T superconductors

    Science.gov (United States)

    Lykov, A. N.

    2008-06-01

    New mixed boundary conditions to the Ginsburg-Landau equations are found to limit the critical temperature ( T) of high- T superconductors. Moreover, the value of the pseudogap in these superconductors can be explained by using the method. As a result, the macroscopic approach is proposed to increase T of cuprate superconductors.

  12. Boundary conditions in Ginsburg-Landau theory and critical temperature of high-Tc superconductors

    International Nuclear Information System (INIS)

    Lykov, A.N.

    2008-01-01

    New mixed boundary conditions to the Ginsburg-Landau equations are found to limit the critical temperature (T c ) of high-T c superconductors. Moreover, the value of the pseudogap in these superconductors can be explained by using the method. As a result, the macroscopic approach is proposed to increase T c of cuprate superconductors

  13. Parents' Criticisms and Attributions about Their Adult Children with High Functioning Autism or Schizophrenia

    Science.gov (United States)

    Wasserman, Stephanie; Weisman de Mamani, Amy; Mundy, Peter

    2010-01-01

    The current study examined the criticism component of expressed emotion (EE) and attributions in parents of adults diagnosed with schizophrenia/schizoaffective disorder (S/SA) or high functioning autism/Asperger's. Consistent with study hypotheses, parents of adults diagnosed with autism/Asperger's disorder exhibited lower levels of high…

  14. An Examination of Critical Thinking Skills in High School Choral Rehearsals

    Science.gov (United States)

    Garrett, Matthew L.

    2013-01-01

    The purpose of this study was to examine the relationship between time spent in nonperformance and critical thinking activities in high school choral rehearsals. Eighteen rehearsal observations were collected from public school music programs. Observed rehearsal behaviors were coded into three categories of nonperformance activity: lower-order…

  15. Motivation, Critical Thinking and Academic Verification of High School Students' Information-seeking Behavior

    Directory of Open Access Journals (Sweden)

    Z Hidayat

    2018-01-01

    Full Text Available High school students have known as Gen Y or Z and their media using can be understand on their information-seeking behavior. This research’s purposes were: 1 to analyze the students’ motivation; 2 to analyze the critical thinking and academic verification; 3 to analyze the information-seeking behavior. This study used quantitative approach through survey among 1125 respondents in nine clusters, i.e. Central, East, North, West, and South of Jakarta, Tangerang, Bekasi, Depok, and Bogor. Schools sampling based on "the best schools rank" by the government, while respondents have taken by accidental in each school. Construct of questionnaire included measurement of motivation, critical thinking and academic verification, and the information-seeking behavior at all. The results showed that the motivations of the use of Internet were dominated by habit to interact and be entertained while on the academic needs are still relatively small but increasing significantly. Students’ self-efficacy, performance and achievement goals tend to be high motives, however the science learning value, and learning environment stimulation were average low motives. High school students indicated that they think critically about the various things that become content primarily in social media but less critical of the academic information subjects. Unfortunately, high school students did not conducted academic verification on the data and information but students tend to do plagiarism.

  16. Electric Grid Expansion Planning with High Levels of Variable Generation

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, Stanton W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); You, Shutang [Univ. of Tennessee, Knoxville, TN (United States); Shankar, Mallikarjun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Yilu [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-02-01

    Renewables are taking a large proportion of generation capacity in U.S. power grids. As their randomness has increasing influence on power system operation, it is necessary to consider their impact on system expansion planning. To this end, this project studies the generation and transmission expansion co-optimization problem of the US Eastern Interconnection (EI) power grid with a high wind power penetration rate. In this project, the generation and transmission expansion problem for the EI system is modeled as a mixed-integer programming (MIP) problem. This study analyzed a time series creation method to capture the diversity of load and wind power across balancing regions in the EI system. The obtained time series can be easily introduced into the MIP co-optimization problem and then solved robustly through available MIP solvers. Simulation results show that the proposed time series generation method and the expansion co-optimization model and can improve the expansion result significantly after considering the diversity of wind and load across EI regions. The improved expansion plan that combines generation and transmission will aid system planners and policy makers to maximize the social welfare. This study shows that modelling load and wind variations and diversities across balancing regions will produce significantly different expansion result compared with former studies. For example, if wind is modeled in more details (by increasing the number of wind output levels) so that more wind blocks are considered in expansion planning, transmission expansion will be larger and the expansion timing will be earlier. Regarding generation expansion, more wind scenarios will slightly reduce wind generation expansion in the EI system and increase the expansion of other generation such as gas. Also, adopting detailed wind scenarios will reveal that it may be uneconomic to expand transmission networks for transmitting a large amount of wind power through a long distance

  17. High frequency vibration characteristics of electric wheel system under in-wheel motor torque ripple

    Science.gov (United States)

    Mao, Yu; Zuo, Shuguang; Wu, Xudong; Duan, Xianglei

    2017-07-01

    With the introduction of in-wheel motor, the electric wheel system encounters new vibration problems brought by motor torque ripple excitation. In order to analyze new vibration characteristics of electric wheel system, torque ripple of in-wheel motor based on motor module and vector control system is primarily analyzed, and frequency/order features of the torque ripple are discussed. Then quarter vehicle-electric wheel system (QV-EWS) dynamics model based on the rigid ring tire assumption is established and the main parameters of the model are identified according to tire free modal test. Modal characteristics of the model are further analyzed. The analysis indicates that torque excitation of in-wheel motor is prone to arouse horizontal vibration, in which in-phase rotational, anti-phase rotational and horizontal translational modes of electric wheel system mainly participate. Based on the model, vibration responses of the QV-EWS under torque ripple are simulated. The results show that unlike vertical low frequency (lower than 20 Hz) vibration excited by road roughness, broadband torque ripple will arouse horizontal high frequency (50-100 Hz) vibration of electric wheel system due to participation of the three aforementioned modes. To verify the theoretical analysis, the bench experiment of electric wheel system is conducted and vibration responses are acquired. The experiment demonstrates the high frequency vibration phenomenon of electric wheel system and the measured order features as well as main resonant frequencies agree with simulation results. Through theoretical modeling, analysis and experiments this paper reveals and explains the high frequency vibration characteristics of electric wheel system, providing references for the dynamic analysis, optimal design of QV-EWS.

  18. Real-time underwater object detection based on an electrically scanned high-resolution sonar

    DEFF Research Database (Denmark)

    Henriksen, Lars

    1994-01-01

    The paper describes an approach to real time detection and tracking of underwater objects, using image sequences from an electrically scanned high-resolution sonar. The use of a high resolution sonar provides a good estimate of the location of the objects, but strains the computers on board, beca...

  19. High-accuracy critical exponents for O(N) hierarchical 3D sigma models

    International Nuclear Information System (INIS)

    Godina, J. J.; Li, L.; Meurice, Y.; Oktay, M. B.

    2006-01-01

    The critical exponent γ and its subleading exponent Δ in the 3D O(N) Dyson's hierarchical model for N up to 20 are calculated with high accuracy. We calculate the critical temperatures for the measure δ(φ-vector.φ-vector-1). We extract the first coefficients of the 1/N expansion from our numerical data. We show that the leading and subleading exponents agree with Polchinski equation and the equivalent Litim equation, in the local potential approximation, with at least 4 significant digits

  20. High latitude stratospheric electrical measurements in fair and foul weather under various solar conditions

    International Nuclear Information System (INIS)

    Holzworth, R.H.

    1981-01-01

    Stratospheric electric field and conductivity measurements during a wide variety of weather and solar conditions are presented. These data are all from high latitude sites in the months of either April or August. The vector electric field is determined by orthogonal double probes connected through high impedance inputs to differential electrometers. The direct conductivity measurement involves determining the relaxation time constant of the medium after refloating a shorted pair of separated probes. Vertical electric field data from several balloon flights with average duration of 18 h at ceiling in fair weather are shown to be well modeled by a simple exponential altitude dependent equation. Examples of solar flare and magnetospheric effects on stratospheric electric fields are shown. Data collected over electrified clouds and thunderstorms are presented along with a discussion of the thunderstorm related electric currents. Lightning stroke signatures in the stratosphere during a large thunderstorm are identified in the electric field data. Current surges through the stratosphere due to DC currents as well as the sferic are calculated. In nearly 1000 h of balloon data no direct solar influence is identified in these data except during major flares. (author)

  1. Structure of the radial electric field and toroidal/poloidal flow in high temperature toroidal plasma

    International Nuclear Information System (INIS)

    Ida, Katsumi

    2001-01-01

    The structure of the radial electric field and toroidal/poloidal flow is discussed for the high temperature plasma in toroidal systems, tokamak and Heliotron type magnetic configurations. The spontaneous toroidal and poloidal flows are observed in the plasma with improved confinement. The radial electric field is mainly determined by the poloidal flow, because the contribution of toroidal flow to the radial electric field is small. The jump of radial electric field and poloidal flow are commonly observed near the plasma edge in the so-called high confinement mode (H-mode) plasmas in tokamaks and electron root plasma in stellarators including Heliotrons. In general the toroidal flow is driven by the momentum input from neutral beam injected toroidally. There is toroidal flow not driven by neutral beam in the plasma and it will be more significant in the plasma with large electric field. The direction of these spontaneous toroidal flows depends on the symmetry of magnetic field. The spontaneous toroidal flow driven by the ion temperature gradient is in the direction to increase the negative radial electric field in tokamak. The direction of spontaneous toroidal flow in Heliotron plasmas is opposite to that in tokamak plasma because of the helicity of symmetry of the magnetic field configuration. (author)

  2. Residual stress evaluation by Barkhausen signals with a magnetic field sensor for high efficiency electrical motors

    Science.gov (United States)

    Tsuchida, Yuji; Enokizono, Masato

    2018-04-01

    The iron loss of industrial motors increases by residual stress during manufacturing processes. It is very important to make clear the distribution of the residual stress in the motor cores to reduce the iron loss in the motors. Barkhausen signals which occur on electrical steel sheets can be used for the evaluation of the residual stress because they are very sensitive to the material properties. Generally, a B-sensor is used to measure Barkhausen signals, however, we developed a new H-sensor to measure them and applied it into the stress evaluation. It is supposed that the Barkhausen signals by using a H-sensor can be much effective to the residual stress on the electrical steel sheets by referring our results regarding to the stress evaluations. We evaluated the tensile stress of the electrical steel sheets by measuring Barkhausen signals by using our developed H-sensor for high efficiency electrical motors.

  3. Improving electrical conductivity in polycarbonate nanocomposites using highly conductive PEDOT/PSS coated MWCNTs

    KAUST Repository

    Zhou, Jian

    2013-07-10

    We describe a strategy to design highly electrically conductive polycarbonate nanocomposites by using multiwalled carbon nanotubes (MWCNTs) coated with a thin layer of poly(3,4-ethylenedioxythiophene)/ poly(styrenesulfonate), a conductive polymer. We found that this coating method improves the electrical properties of the nanocomposites in two ways. First, the coating becomes the main electrical conductive path. Second, the coating promotes the formation of a percolation network at a low filler concentration (0.3 wt %). To tailor the electrical properties of the conductive polymer coating, we used a polar solvent ethylene glycol, and we can tune the final properties of the nanocomposite by controlling the concentrations of the elementary constituents or the intrinsic properties of the conductive polymer coating. This very flexible technique allows for tailoring the properties of the final product. © 2013 American Chemical Society.

  4. Electric field driven plasmon dispersion in AlGaN/GaN high electron mobility transistors

    International Nuclear Information System (INIS)

    Tan Ren-Bing; Qin Hua; Zhang Xiao-Yu; Xu Wen

    2013-01-01

    We present a theoretical study on the electric field driven plasmon dispersion of the two-dimensional electron gas (2DEG) in AlGaN/GaN high electron mobility transistors (HEMTs). By introducing a drifted Fermi—Dirac distribution, we calculate the transport properties of the 2DEG in the AlGaN/GaN interface by employing the balance-equation approach based on the Boltzmann equation. Then, the nonequilibrium Fermi—Dirac function is obtained by applying the calculated electron drift velocity and electron temperature. Under random phase approximation (RPA), the electric field driven plasmon dispersion is investigated. The calculated results indicate that the plasmon frequency is dominated by both the electric field E and the angle between wavevector q and electric field E. Importantly, the plasmon frequency could be tuned by the applied source—drain bias voltage besides the gate voltage (change of the electron density)

  5. Design of High-Fidelity Testing Framework for Secure Electric Grid Control

    Energy Technology Data Exchange (ETDEWEB)

    Yoginath, Srikanth B [ORNL; Perumalla, Kalyan S [ORNL

    2014-01-01

    A solution methodology and implementation components are presented that can uncover unwanted, unintentional or unanticipated effects on electric grids from changes to actual electric grid control software. A new design is presented to leapfrog over the limitations of current modeling and testing techniques for cyber technologies in electric grids. We design a fully virtualized approach in which actual, unmodified operational software under test is enabled to interact with simulated surrogates of electric grids. It enables the software to influence the (simulated) grid operation and vice versa in a controlled, high fidelity environment. Challenges in achieving such capability include achieving low-overhead time control mechanisms in hypervisor schedulers, network capture and time-stamping, translation of network packets emanating from grid software into discrete events of virtual grid models, translation back from virtual sensors/actuators into data packets to control software, and transplanting the entire system onto an accurately and efficiently maintained virtual-time plane.

  6. A High Power Density Integrated Charger for Electric Vehicles with Active Ripple Compensation

    OpenAIRE

    Pan, Liwen; Zhang, Chengning

    2015-01-01

    This paper suggests a high power density on-board integrated charger with active ripple compensation circuit for electric vehicles. To obtain a high power density and high efficiency, silicon carbide devices are reported to meet the requirement of high-switching-frequency operation. An integrated bidirectional converter is proposed to function as AC/DC battery charger and to transfer energy between battery pack and motor drive of the traction system. In addition, the conventional H-bridge cir...

  7. Critical operations capabilities in a high cost environment: a multiple case study

    Science.gov (United States)

    Sansone, C.; Hilletofth, P.; Eriksson, D.

    2018-04-01

    Operations capabilities have been a popular research area for many years and several frameworks have been proposed in the literature. The current frameworks do not take specific contexts into consideration, for instance a high cost environment. This research gap is of particular interest since a manufacturing relocation process has been ongoing the last decades, leading to a huge amount of manufacturing being moved from high to low cost environments. The purpose of this study is to identify critical operations capabilities in a high cost environment. The two research questions were: What are the critical operations capabilities dimensions in a high cost environment? What are the critical operations capabilities in a high cost environment? A multiple case study was conducted and three Swedish manufacturing firms were selected. The study was based on the investigation of an existing framework of operations capabilities. The main dimensions of operations capabilities included in the framework were: cost, quality, delivery, flexibility, service, innovation and environment. Each of the dimensions included two or more operations capabilities. The findings confirmed the validity of the framework and its usefulness in a high cost environment and a new operations capability was revealed (employee flexibility).

  8. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    Science.gov (United States)

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  9. Comparison of High-Fidelity Computational Tools for Wing Design of a Distributed Electric Propulsion Aircraft

    Science.gov (United States)

    Deere, Karen A.; Viken, Sally A.; Carter, Melissa B.; Viken, Jeffrey K.; Derlaga, Joseph M.; Stoll, Alex M.

    2017-01-01

    A variety of tools, from fundamental to high order, have been used to better understand applications of distributed electric propulsion to aid the wing and propulsion system design of the Leading Edge Asynchronous Propulsion Technology (LEAPTech) project and the X-57 Maxwell airplane. Three high-fidelity, Navier-Stokes computational fluid dynamics codes used during the project with results presented here are FUN3D, STAR-CCM+, and OVERFLOW. These codes employ various turbulence models to predict fully turbulent and transitional flow. Results from these codes are compared for two distributed electric propulsion configurations: the wing tested at NASA Armstrong on the Hybrid-Electric Integrated Systems Testbed truck, and the wing designed for the X-57 Maxwell airplane. Results from these computational tools for the high-lift wing tested on the Hybrid-Electric Integrated Systems Testbed truck and the X-57 high-lift wing presented compare reasonably well. The goal of the X-57 wing and distributed electric propulsion system design achieving or exceeding the required ?? (sub L) = 3.95 for stall speed was confirmed with all of the computational codes.

  10. Optimizing the U.S. Electric System with a High Penetration of Renewables

    Science.gov (United States)

    Corcoran, B. A.; Jacobson, M. Z.

    2013-12-01

    As renewable energy generators are increasingly being installed throughout the U.S., there is growing interest in interconnecting diverse renewable generators (primarily wind and solar) across large geographic areas through an enhanced transmission system. This reduces variability in the aggregate power output, increases system reliability, and allows for the development of the best overall group of renewable technologies and sites to meet the load. Studies are therefore needed to determine the most efficient and economical plan to achieve large area interconnections in a future electric system with a high penetration of renewables. This research quantifies the effects of aggregating electric load together with diverse renewable generation throughout the ten Federal Energy Regulatory Commission (FERC) regions in the contiguous U.S. A deterministic linear program has been built in AMPL (A Mathematical Programming Language) to solve for the least-cost organizational structure and system (generators, transmission, and storage) for a highly renewable electric grid. The analysis will 1) examine a highly renewable 2006 electric system, including various sensitivity cases and additional system components such as additional load from electric vehicles, and 2) create a 'roadmap' from the existing 2006 system to a highly renewable system in 2030, accounting for projected price and demand changes and generator retirements based on age and environmental regulations. Ideally, results from this study will offer insight for a federal renewable energy policy (such as a renewable portfolio standard) and how to best organize U.S. regions for transmission planning.

  11. Dehydration of chlorite explains anomalously high electrical conductivity in the mantle wedges.

    Science.gov (United States)

    Manthilake, Geeth; Bolfan-Casanova, Nathalie; Novella, Davide; Mookherjee, Mainak; Andrault, Denis

    2016-05-01

    Mantle wedge regions in subduction zone settings show anomalously high electrical conductivity (~1 S/m) that has often been attributed to the presence of aqueous fluids released by slab dehydration. Laboratory-based measurements of the electrical conductivity of hydrous phases and aqueous fluids are significantly lower and cannot readily explain the geophysically observed anomalously high electrical conductivity. The released aqueous fluid also rehydrates the mantle wedge and stabilizes a suite of hydrous phases, including serpentine and chlorite. In this present study, we have measured the electrical conductivity of a natural chlorite at pressures and temperatures relevant for the subduction zone setting. In our experiment, we observe two distinct conductivity enhancements when chlorite is heated to temperatures beyond its thermodynamic stability field. The initial increase in electrical conductivity to ~3 × 10(-3) S/m can be attributed to chlorite dehydration and the release of aqueous fluids. This is followed by a unique, subsequent enhancement of electrical conductivity of up to 7 × 10(-1) S/m. This is related to the growth of an interconnected network of a highly conductive and chemically impure magnetite mineral phase. Thus, the dehydration of chlorite and associated processes are likely to be crucial in explaining the anomalously high electrical conductivity observed in mantle wedges. Chlorite dehydration in the mantle wedge provides an additional source of aqueous fluid above the slab and could also be responsible for the fixed depth (120 ± 40 km) of melting at the top of the subducting slab beneath the subduction-related volcanic arc front.

  12. Propagation of 1-THz bandwidth electrical pulses on high Tc superconducting transmission lines

    International Nuclear Information System (INIS)

    Nuss, M.C.; Mankiewich, P.M.; Howard, R.E.; Harvey, T.E.; Brandle, C.D.; Straugh, B.L.; Smith, P.R.

    1989-01-01

    The new high temperature superconductors have triggered enormous interest not only because of the unique physics involved but also because of their technical potentials, such as the promise for propagation of extremely short electrical pulses. Superconducting band caps of --20TH z are predicted assuming BCS theory for the superconductor, making lossless propagation of electrical pulses as short as 50 fs possible. Despite microwave measurements at low frequencies of several gigahertz first studies at higher frequencies by Dykaar et al have shown distortion-free propagation of 100-GHz electrical pulses on YBa 2 Cu 3 O 3 (YBCO) lines for --5-mm propagation distance. Results were also reported for aluminum coplanar lines and a YBCO ground plane. The authors report on the propagation of 1-ps electrical pulses (1-THz bandwidth) on YBCO coplanar transmission lines defined on lanthanum gallate (LaGaO 3 ) as a substrate. On LaGaO 3 , YBCO grows highly oriented as on SrTiO 3 . However, unlike SrTiO 3 , LaGaO 3 has a much lower dielectric constant and small losses in the terahertz frequency range. Electrical pulses of --750-fs duration are generated in a radiation-damaged silicon-on-sapphire photoconductive switch integrated into a 20-μm coplanar stripline with 10-μm spacing and excited with 100-fs optical pulses from a CPM laser. An μ1-THz bandwidth electrical contact is made to the YBCO coplanar stripline defined on LaGaO 3 using a flip-chip geometry. They find that electrical pulses broaden only from 750 fs to 1 ps with little loss in amplitude on traveling through their flip-chip input and propagated electrical pulses are probed by electooptic sampling in two small LiTaO 3 crystals separated by 3 mm

  13. Brachial artery protected by wrapped latissimus dorsi muscle flap in high voltage electrical injury

    Science.gov (United States)

    Gencel, E.; Eser, C.; Kokacya, O.; Kesiktas, E.; Yavuz, M.

    2016-01-01

    Summary High voltage electrical injury can disrupt the vascular system and lead to extremity amputations. It is important to protect main vessels from progressive burn necrosis in order to salvage a limb. The brachial artery should be totally isolated from the burned area by a muscle flap to prevent vessel disruption. In this study, we report the use of a wrap-around latissimus dorsi muscle flap to protect a skeletonized brachial artery in a high voltage electrical injury in order to salvage the upper extremity and restore function. The flap wrapped around the exposed brachial artery segment and luminal status of the artery was assessed using magnetic resonance angiography. No vascular intervention was required. The flap survived completely with good elbow function. Extremity amputation was not encountered. This method using a latissimus dorsi flap allows the surgeon to protect the main upper extremity artery and reconstruct arm defects, which contributes to restoring arm function in high voltage electrical injury. PMID:28149236

  14. Validation of the Monte Carlo Criticality Program KENO V. a for highly-enriched uranium systems

    Energy Technology Data Exchange (ETDEWEB)

    Knight, J.R.

    1984-11-01

    A series of calculations based on critical experiments have been performed using the KENO V.a Monte Carlo Criticality Program for the purpose of validating KENO V.a for use in evaluating Y-12 Plant criticality problems. The experiments were reflected and unreflected systems of single units and arrays containing highly enriched uranium metal or uranium compounds. Various geometrical shapes were used in the experiments. The SCALE control module CSAS25 with the 27-group ENDF/B-4 cross-section library was used to perform the calculations. Some of the experiments were also calculated using the 16-group Hansen-Roach Library. Results are presented in a series of tables and discussed. Results show that the criteria established for the safe application of the KENO IV program may also be used for KENO V.a results.

  15. Critical Thinking Skills of an Eighth Grade Male Student with High Mathematical Ability in Solving Problem

    Science.gov (United States)

    Ismail

    2018-01-01

    This study aims to describe student’s critical thinking skill of grade VIII in solving mathematical problem. A qualitative research was conducted to a male student with high mathematical ability. Student’s critical thinking skill was obtained from a depth task-based interview. The result show that male student’s critical thinking skill of the student as follows. In understanding the problem, the student did categorization, significance decoding, and meaning clarification. In devising a plan he examined his ideas, detected his argument, analyzed his argument and evaluated his argument. During the implementation phase, the skill that appeared were analyzing of the argument and inference skill such as drawing conclusion, deliver alternative thinking, and problem solving skills. At last, in rechecking all the measures, they did self-correcting and self-examination.

  16. High level issues in reliability quantification of safety-critical software

    International Nuclear Information System (INIS)

    Kim, Man Cheol

    2012-01-01

    For the purpose of developing a consensus method for the reliability assessment of safety-critical digital instrumentation and control systems in nuclear power plants, several high level issues in reliability assessment of the safety-critical software based on Bayesian belief network modeling and statistical testing are discussed. Related to the Bayesian belief network modeling, the relation between the assessment approach and the sources of evidence, the relation between qualitative evidence and quantitative evidence, how to consider qualitative evidence, and the cause-consequence relation are discussed. Related to the statistical testing, the need of the consideration of context-specific software failure probabilities and the inability to perform a huge number of tests in the real world are discussed. The discussions in this paper are expected to provide a common basis for future discussions on the reliability assessment of safety-critical software. (author)

  17. Consideration of critically when directly disposing highly enriched spent nuclear fuel in unsaturated tuff: Bounding estimates

    International Nuclear Information System (INIS)

    Rechard, R.P.; Tierney, M.S.; Sanchez, L.C.; Martell, M.-A.

    1996-05-01

    This report presents one of 2 approaches (bounding calculations) which were used in a 1994 study to examine the possibility of a criticality in a repository. Bounding probabilities, although rough, point to the difficulty of creating conditions under which a critical mass could be assembled (container corrosion, separation of neutron absorbers from fissile material, collapse or precipitation of fissile material) and how significant the geochemical and hydrologic phenomena are. The study could not conceive of a mechanism consistent with conditions under which an atomic explosion could occur. Should a criticality occur in or near a container in the future, boundary consequence calculations showed that fissions from one critical event ( 20 fissions, if similar to aqueous and metal accidents and experiments) are quite small compared to the amount of fissions represented by the spent fuel itself. If it is assumed that the containers necessary to hold the highly enriched spent fuel went critical once per day for 1 million years, creating an energy release of about 10 20 fissions, the number of fissions equals about 10 28 , which corresponds to only 1% of the fission inventory in a repository containing 70,000 metric tons of heavy metal, the expected size for the proposed repository at Yucca Mountain, Nevada

  18. Consideration of critically when directly disposing highly enriched spent nuclear fuel in unsaturated tuff: Bounding estimates

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, R.P.; Tierney, M.S.; Sanchez, L.C.; Martell, M.-A.

    1996-05-01

    This report presents one of 2 approaches (bounding calculations) which were used in a 1994 study to examine the possibility of a criticality in a repository. Bounding probabilities, although rough, point to the difficulty of creating conditions under which a critical mass could be assembled (container corrosion, separation of neutron absorbers from fissile material, collapse or precipitation of fissile material) and how significant the geochemical and hydrologic phenomena are. The study could not conceive of a mechanism consistent with conditions under which an atomic explosion could occur. Should a criticality occur in or near a container in the future, boundary consequence calculations showed that fissions from one critical event (<10{sup 20} fissions, if similar to aqueous and metal accidents and experiments) are quite small compared to the amount of fissions represented by the spent fuel itself. If it is assumed that the containers necessary to hold the highly enriched spent fuel went critical once per day for 1 million years, creating an energy release of about 10{sup 20} fissions, the number of fissions equals about 10{sup 28}, which corresponds to only 1% of the fission inventory in a repository containing 70,000 metric tons of heavy metal, the expected size for the proposed repository at Yucca Mountain, Nevada.

  19. A FORMATIVE ASSESSMENT MODEL OF CRITICAL THINKING IN MATHEMATICS LEARNING IN JUNIOR HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    R. Rosnawati

    2015-12-01

    Full Text Available This study aims to obtain a valid and reliable formative evaluation model of critical thinking. The method used in this research was the research and development by integrating Borg & Gall's model and  Plomp's development model. The ten steps Borg & Gall’s model were modified into five stages as the stages in the Plomp's model. The subjects in this study were 1,446 students of junior high schools in DIY, 14 mathematics teacher, and six experts. The content validity employed was expert judgment, the empirical validity and reliability used were loading factor, item analysis used PCM 1PL, and the relationship between disposition and critical thinking skill used was structural equation modeling (SEM. The developed formative evaluation model is the procedural model. There are five aspects of critical thinking skill: mathematic reasoning, interpretation, analysis, evaluation, and inference, which entirely composed of 42 items. The validity of the critical thinking skill instruments achieves a significance degree as indicated by the lowest and the highest loading factors of 0.38 and 0.74 subsequently, the reliability of every aspect in a good category. The average level of difficulty is 0.00 with the standard deviation of 0.45 which is in a good category. The peer assessment questionnaire of critical thinking disposition consists of seven aspects: truth-seeking, open-minded, analysis, systematic, self-confidence, inquisitiveness, and maturity with 23 items. The critical thinking disposition validity achieves the significance degree as indicated by the lowest and the high factor loading of 0.66 and 0.76 subsequently, and the reliability of every aspect in a good category. Based on the analysis of the structural equation model, the model fits the data.

  20. Station-keeping of a high-altitude balloon with electric propulsion and wireless power transmission: A concept study

    Science.gov (United States)

    van Wynsberghe, Erinn; Turak, Ayse

    2016-11-01

    A stable, ultra long-duration high-altitude balloon (HAB) platform which can maintain stationary position would represent a new paradigm for telecommunications and high-altitude observation and transmission services, with greatly reduced cost and complexity compared to existing technologies including satellites, telecom towers, and unmanned aerial vehicles (UAVs). This contribution proposes a lightweight superpressure balloon platform for deployment to an altitude of 25 km. Electrohydrodynamic (EHD) thrusters are presented to maintain position by overcoming stratospheric winds. Critical to maintaining position is a continual supply of electrical power to operate the on-board propulsion system. One viable solution is to deliver power wirelessly to a high-altitude craft from a ground-based transmitter. Microwave energy, not heavily attenuated by the atmosphere, can be provided remotely from a ground-based generator (magnetron, klystron, etc.) and steered electrically with an antenna array (phased array) at a designated frequency (such as 2.45 or 5.8 GHz). A rectifying antenna ("rectenna") on the bottom of the balloon converts waves into direct current for on-board use. Preliminary mission architecture, energy requirements, and safety concerns for a proposed system are presented along with recommended future work.

  1. The potential of large critical currents in the high Tc oxides

    International Nuclear Information System (INIS)

    Deutcher, G.

    1993-01-01

    The potential for high critical current densities is examined. on a thermodynamical basis, the energy scale for vortex pinning can be derived for instance from a measurement of the width of the critical region. This energy scale is of the order of 0.2 eV in YBCO, which is sufficient for practical applications. Another important parameter is the short coherence length. The inner plane length, of the order of a few lattice spacing, is favorable for pinning by point defects. But the very short outer plane length gives rise to anomalous magnetic behavior, unfavorable for high-field applications at high temperature; this is true in particular in most anisotropic oxides, such as the Bi compounds (author)

  2. High-Fidelity Simulations of Electrically-Charged Atomizing Diesel-Type Jets

    Science.gov (United States)

    Gaillard, Benoit; Owkes, Mark; van Poppel, Bret

    2015-11-01

    Combustion of liquid fuels accounts for over a third of the energy usage today. Improving efficiency of combustion systems is critical to meet the energy needs while limiting environmental impacts. Additionally, a shift away from traditional fossil fuels to bio-derived alternatives requires fuel injection systems that can atomize fuels with a wide range of properties. In this work, the potential benefits of electrically-charged atomization is investigated using numerical simulations. Particularly, the electrostatic forces on the hydrodynamic jet are quantified and the impact of the forces is analyzed by comparing simulations of Diesel-type jets at realistic flow conditions. The simulations are performed using a state-of-the-art numerical framework that globally conserves mass, momentum, and the electric charge density even at the gas-liquid interface where discontinuities exist.

  3. Determining of the electric field strength using high frequency broadband measurements

    Directory of Open Access Journals (Sweden)

    Vulević Branislav D.

    2017-01-01

    Full Text Available Exposure of humans to electromagnetic fields of high frequency (above 100 kHz, i.e. radiofrequency radiation from the modern wireless systems, today inevitable is. The purpose of this paper is to highlight the importance of broadband measurements of the electric field of high frequency in order to fast and reliable assessment of human exposure. A practical method of ‘in situ’ measurement the electric field intensity which is related to the frequency range of 3 MHz to 18 GHz, is provided.

  4. Insulation co-ordination in high-voltage electric power systems

    CERN Document Server

    Diesendorf, W

    2015-01-01

    Insulation Co-ordination in High-Voltage Electric Power Systems deals with the methods of insulation needed in different circumstances. The book covers topics such as overvoltages and lightning surges; disruptive discharge and withstand voltages; self-restoring and non-self-restoring insulation; lightning overvoltages on transmission lines; and the attenuation and distortion of lightning surges. Also covered in the book are topics such as the switching surge designs of transmission lines, as well as the insulation coordination of high-voltage stations. The text is recommended for electrical en

  5. Critical infrastructure protection

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, F. [Canadian Electricity Association, Toronto, ON (Canada)

    2003-04-01

    The need to protect critical electrical infrastructure from terrorist attacks, or other physical damage, including weather related events, or the potential impact of computer viruses and other attacks on IT resources are discussed. Activities of the North American Electric Reliability Council (NERC) are highlighted which seek to safeguard the North American bulk electric power system principally through the Information Sharing and Analysis Sector (ES-ISAC). ES-ISAC serves the electricity sector by facilitating communication between electric sector participants, federal government and other critical infrastructure industries by disseminating threat indications, analyses and warnings, together with interpretations, to assist the industry in taking infrastructure protection actions. Attention is drawn to the numerous cyber incidents in recent years, which although resulted in no loss of service to electricity customers so far, in at least one instance (the January 25th SOL-Slammer worm incident) resulted in degradation of service in a number of sectors, including financial, transportation and telecommunication services. The increasing frequency of cyber-based attacks, coupled with the industry's growing dependence on e-commerce and electronic controls, are good reasons to believe that critical infrastructure protection (CIP) poses a serious challenge to the industry's risk management practices. The Canadian Electricity Association (CEA) is an active participant in ES-ISAC and works cooperatively with a range of partners, such as the Edison Electric Institute and the American Public Power Association to ensure coordination and effective protection program delivery for the electric power sector. The Early Warning System (EWS) developed by the CIP Working Group is one of the results of this cooperation. EWS uses the Internet, e-mail, web-enabled cell phones and Blackberry hand-held devices to deliver real-time threat information to members on a 24/7 basis. EWS

  6. Climate and Water Vulnerability of the US Electricity Grid Under High Penetrations of Renewable Energy

    Science.gov (United States)

    Macknick, J.; Miara, A.; O'Connell, M.; Vorosmarty, C. J.; Newmark, R. L.

    2017-12-01

    The US power sector is highly dependent upon water resources for reliable operations, primarily for thermoelectric cooling and hydropower technologies. Changes in the availability and temperature of water resources can limit electricity generation and cause outages at power plants, which substantially affect grid-level operational decisions. While the effects of water variability and climate changes on individual power plants are well documented, prior studies have not identified the significance of these impacts at the regional systems-level at which the grid operates, including whether there are risks for large-scale blackouts, brownouts, or increases in production costs. Adequately assessing electric grid system-level impacts requires detailed power sector modeling tools that can incorporate electric transmission infrastructure, capacity reserves, and other grid characteristics. Here, we present for the first time, a study of how climate and water variability affect operations of the power sector, considering different electricity sector configurations (low vs. high renewable) and environmental regulations. We use a case study of the US Eastern Interconnection, building off the Eastern Renewable Generation Integration Study (ERGIS) that explored operational challenges of high penetrations of renewable energy on the grid. We evaluate climate-water constraints on individual power plants, using the Thermoelectric Power and Thermal Pollution (TP2M) model coupled with the PLEXOS electricity production cost model, in the context of broader electricity grid operations. Using a five minute time step for future years, we analyze scenarios of 10% to 30% renewable energy penetration along with considerations of river temperature regulations to compare the cost, performance, and reliability tradeoffs of water-dependent thermoelectric generation and variable renewable energy technologies under climate stresses. This work provides novel insights into the resilience and

  7. Advanced ceramic composite for high energy resistors. Characterization of electrical and physical properties

    International Nuclear Information System (INIS)

    Farrokh, Fattahi; Navid, Tagizadegan; Naser, Tabatabaei

    2005-01-01

    Full text : There is a need to characterize and apply advanced materials to improve the performance of components used in pulse power systems. One area for innovation is the use of bulk electrically conductive ceramics for non-inductive, high energy and high power electrical resistors. Standard Ceramics, Inc. has developed a unique silicon carbide structural ceramic composite which exhibits electrical conductivity. The new conductive bulk ceramic material has a controlled microstructure, which results an improved homogeneity, making the material suitable for use as a non-inductive, high energy resistor. The new material has higher density, highee peak of temperature limit and greater physical strength compared with bulk ceramics currently used for pulsed power resistors. This paper describes characterization of the material's physical and electrical properties and relates them to improvements in low-power density, as compared to existing components would be expected and derived from specific properties such as good thermal conductivity, high strength, thermal shock resistance and high temperature capability. The bulk resistor approach that weas proposed offers high reliability through better mechanical properties and simplicity of construction

  8. Effectiveness of guided inquiry learning model to improve students’ critical thinking skills at senior high school

    Science.gov (United States)

    Nisa, E. K.; Koestiari, T.; Habibbulloh, M.; Jatmiko, Budi

    2018-03-01

    This research aimed to describe the effectiveness of guided inquiry learning model to improve students' critical thinking skills. Subjects in the research were 90 students at three groups of senior high school grade X on Tarik (Indonesia), which follows a physics lesson on static fluid material in academic year 2016/2017. The research was used one group pre-test and post-test design. Before and after being given physics learning with guided discovery learning model, students in the three groups were given the same test (pre-test and post-test). The results of this research showed: 1) there is an increased score of students' critical thinking skills in each group on α = 5%; 2) average N-gain of students' critical thinking skills of each group is a high category; and 3) average N-gain of the three groups did not differ. The conclusion of this research is that learning model of guided inquiry effective to improve students' critical thinking skills.

  9. DOE Task Force meeting on Electrical Breakdown of Insulating Ceramics in a High Radiation Field

    International Nuclear Information System (INIS)

    Green, P.H.

    1991-08-01

    This volume contains the abstracts and presentation material from the Research Assistance Task Force Meeting ''Electrical Breakdown of Insulating Ceramics in a High-Radiation Field.'' The meeting was jointly sponsored by the Office of Basic Energy Sciences and the Office of Fusion Energy of the US Department of Energy in Vail, Colorado, May 28--June 1, 1991. The 26 participants represented expertise in fusion, radiation damage, electrical breakdown, ceramics, and semiconductor and electronic structures. These participants came from universities, industries, national laboratories, and government. The attendees represented eight nations. The Task Force meeting was organized in response to the recent discovery that a combination of temperature, electric field, and radiation for an extended period of time has an unexplained adverse effect in ceramics, termed radiation-enhanced electrical degradation (REED). REED occurs after an incubation period and continues to accelerate with irradiation until the ceramics can no longer be regarded as insulators. It appears that REED is irreversible and the ceramic insulators cannot be readily annealed or otherwise repaired for future services. This effect poses a serious threat for fusion reactors, which require electrical insulators in diagnostic devices, in radio frequency and neutral beam systems, and in magnetic assemblies. The problem of selecting suitable electrical insulating materials in thus far more serious than previously anticipated

  10. Conductor of high electrical current at high temperature in oxygen and liquid metal environment

    Science.gov (United States)

    Powell, IV, Adam Clayton; Pati, Soobhankar; Derezinski, Stephen Joseph; Lau, Garrett; Pal, Uday B.; Guan, Xiaofei; Gopalan, Srikanth

    2016-01-12

    In one aspect, the present invention is directed to apparatuses for and methods of conducting electrical current in an oxygen and liquid metal environment. In another aspect, the invention relates to methods for production of metals from their oxides comprising providing a cathode in electrical contact with a molten electrolyte, providing a liquid metal anode separated from the cathode and the molten electrolyte by a solid oxygen ion conducting membrane, providing a current collector at the anode, and establishing a potential between the cathode and the anode.

  11. High-sensitivity visualization of localized electric fields using low-energy electron beam deflection

    Science.gov (United States)

    Jeong, Samuel; Ito, Yoshikazu; Edwards, Gary; Fujita, Jun-ichi

    2018-06-01

    The visualization of localized electronic charges on nanocatalysts is expected to yield fundamental information about catalytic reaction mechanisms. We have developed a high-sensitivity detection technique for the visualization of localized charges on a catalyst and their corresponding electric field distribution, using a low-energy beam of 1 to 5 keV electrons and a high-sensitivity scanning transmission electron microscope (STEM) detector. The highest sensitivity for visualizing a localized electric field was ∼0.08 V/µm at a distance of ∼17 µm from a localized charge at 1 keV of the primary electron energy, and a weak local electric field produced by 200 electrons accumulated on the carbon nanotube (CNT) apex can be visualized. We also observed that Au nanoparticles distributed on a CNT forest tended to accumulate a certain amount of charges, about 150 electrons, at a ‑2 V bias.

  12. High-performance, polymer-based direct cellular interfaces for electrical stimulation and recording

    Science.gov (United States)

    Kim, Seong-Min; Kim, Nara; Kim, Youngseok; Baik, Min-Seo; Yoo, Minsu; Kim, Dongyoon; Lee, Won-June; Kang, Dong-Hee; Kim, Sohee; Lee, Kwanghee; Yoon, Myung-Han

    2018-04-01

    Due to the trade-off between their electrical/electrochemical performance and underwater stability, realizing polymer-based, high-performance direct cellular interfaces for electrical stimulation and recording has been very challenging. Herein, we developed transparent and conductive direct cellular interfaces based on a water-stable, high-performance poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) film via solvent-assisted crystallization. The crystallized PEDOT:PSS on a polyethylene terephthalate (PET) substrate exhibited excellent electrical/electrochemical/optical characteristics, long-term underwater stability without film dissolution/delamination, and good viability for primarily cultured cardiomyocytes and neurons over several weeks. Furthermore, the highly crystallized, nanofibrillar PEDOT:PSS networks enabled dramatically enlarged surface areas and electrochemical activities, which were successfully employed to modulate cardiomyocyte beating via direct electrical stimulation. Finally, the high-performance PEDOT:PSS layer was seamlessly incorporated into transparent microelectrode arrays for efficient, real-time recording of cardiomyocyte action potentials with a high signal fidelity. All these results demonstrate the strong potential of crystallized PEDOT:PSS as a crucial component for a variety of versatile bioelectronic interfaces.

  13. Statistical properties of Joule heating rate, electric field and conductances at high latitudes

    Directory of Open Access Journals (Sweden)

    A. T. Aikio

    2009-07-01

    Full Text Available Statistical properties of Joule heating rate, electric field and conductances in the high latitude ionosphere are studied by a unique one-month measurement made by the EISCAT incoherent scatter radar in Tromsø (66.6 cgmlat from 6 March to 6 April 2006. The data are from the same season (close to vernal equinox and from similar sunspot conditions (about 1.5 years before the sunspot minimum providing an excellent set of data to study the MLT and Kp dependence of parameters with high temporal and spatial resolution.

    All the parameters show a clear MLT variation, which is different for low and high Kp conditions. Our results indicate that the response of morning sector conductances and conductance ratios to increased magnetic activity is stronger than that of the evening sector. The co-location of Pedersen conductance maximum and electric field maximum in the morning sector produces the largest Joule heating rates 03–05 MLT for Kp≥3. In the evening sector, a smaller maximum occurs at 18 MLT. Minimum Joule heating rates in the nightside are statistically observed at 23 MLT, which is the location of the electric Harang discontinuity.

    An important outcome of the paper are the fitted functions for the Joule heating rate as a function of electric field magnitude, separately for four MLT sectors and two activity levels (Kp<3 and Kp≥3. In addition to the squared electric field, the fit includes a linear term to study the possible anticorrelation or correlation between electric field and conductance. In the midday sector, positive correlation is found as well as in the morning sector for the high activity case. In the midnight and evening sectors, anticorrelation between electric field and conductance is obtained, i.e. high electric fields are associated with low conductances. This is expected to occur in the return current regions adjacent to

  14. Statistical properties of Joule heating rate, electric field and conductances at high latitudes

    Directory of Open Access Journals (Sweden)

    A. T. Aikio

    2009-07-01

    Full Text Available Statistical properties of Joule heating rate, electric field and conductances in the high latitude ionosphere are studied by a unique one-month measurement made by the EISCAT incoherent scatter radar in Tromsø (66.6 cgmlat from 6 March to 6 April 2006. The data are from the same season (close to vernal equinox and from similar sunspot conditions (about 1.5 years before the sunspot minimum providing an excellent set of data to study the MLT and Kp dependence of parameters with high temporal and spatial resolution. All the parameters show a clear MLT variation, which is different for low and high Kp conditions. Our results indicate that the response of morning sector conductances and conductance ratios to increased magnetic activity is stronger than that of the evening sector. The co-location of Pedersen conductance maximum and electric field maximum in the morning sector produces the largest Joule heating rates 03–05 MLT for Kp≥3. In the evening sector, a smaller maximum occurs at 18 MLT. Minimum Joule heating rates in the nightside are statistically observed at 23 MLT, which is the location of the electric Harang discontinuity. An important outcome of the paper are the fitted functions for the Joule heating rate as a function of electric field magnitude, separately for four MLT sectors and two activity levels (Kp<3 and Kp≥3. In addition to the squared electric field, the fit includes a linear term to study the possible anticorrelation or correlation between electric field and conductance. In the midday sector, positive correlation is found as well as in the morning sector for the high activity case. In the midnight and evening sectors, anticorrelation between electric field and conductance is obtained, i.e. high electric fields are associated with low conductances. This is expected to occur in the return current regions adjacent to auroral arcs as a result of ionosphere-magnetosphere coupling, as discussed by Aikio et al. (2004 In

  15. Experience of Using Domestic High-Frequency Electric Welding Technology in Surgical Treatment of Patients with Abdominal Pathology

    Directory of Open Access Journals (Sweden)

    A.M. Babiy

    2014-04-01

    Full Text Available The article presents the experience of using electric welding technology of biological tissues with domestic high-frequency electrical generator EC 300 M1 in 176 patients at open and laparoscopic surgery for abdominal pathology. The analysis of findings showed that electric welding of living tissue provides reliable hemostasis, promotes tissue repair after their separation.

  16. Impact of pulsed-electric field and high-voltage electrical discharges on red wine microbial stabilization and quality characteristics.

    Science.gov (United States)

    Delsart, C; Grimi, N; Boussetta, N; Miot Sertier, C; Ghidossi, R; Vorobiev, E; Mietton Peuchot, M

    2016-01-01

    In this study, pulsed-electric fields (PEF) and high-voltage electrical discharges (HVED) are proposed as new techniques for the microbial stabilization of red wines before bottling. The efficiency of the treatment was then evaluated. PEF and HVED-treatments have been applied to wine for the inactivation of Oenococcus oeni CRBO 9304, O. oeni CRBO 0608, Pediococcus parvulus CRBO 2.6 and Brettanomyces bruxellensis CB28. Different treatment times (1, 2, 4, 6, 8 and 10 ms) were used at 20 kV cm(-1) for the PEF treatments and at 40 kV for the HVED treatments, which correspond to applied energies from 80 to 800 kJ l(-1) . The effects of the treatments on the microbial inactivation rate and on various characteristics of red wines (phenolic composition, chromatic characteristics and physico-chemical parameters) were measured. The application of PEF or HVED treatments on red wine allowed the inactivation of alteration yeasts (B. bruxellensis CB28) and bacteria (O. oeni CRBO 9304, O. oeni CRBO 0608 and P. parvulus CRBO 2.6). The electric discharges at 40 kV were less effective than the PEF even after 10 ms of treatments. Indeed, 4 ms of PEF treatment at 20 kV cm(-1) were sufficient to inactivate all micro-organisms present in the wines. Also, the use of PEF had no negative impact on the composition of wines compared to the HVED treatments. Contrary to PEF, the phenolics compounds were degraded after the HVED treatment and the physico-chemical composition of wine were modified with HVED. PEF technology seems to be an interesting alternative to stabilize microbiologically wines before bottling and without modifying their composition. This process offers many advantages for winemakers: no chemical inputs, low energy consumption (320 kJ l(-1) ), fast (treatment time of 4 ms) and athermal (ΔT ≈ 10°C). © 2015 The Society for Applied Microbiology.

  17. Development of E-Book Multimedia Model to Increase Critical Thinking of Senior High School Students

    Directory of Open Access Journals (Sweden)

    Suparno Suparno

    2018-03-01

    Full Text Available This study aims to develop the interactive e-book multimedia model to improve the students' critical thinking ability (KBK. Critical thinking is very important to develop because it provides a high level of reasoning thinking that provides permanent experience to students through conscious and controlled decision making in a rational, reflective, responsible manner with the optimization of potential. Flash-based e-book media is capable of interactively loading videos, pictures, practice questions and learning with directed directions from the teacher. The research method developed is research and development. The output products are learning plan, KBK evaluation question, flash-based interactive e-book multimedia, and quasi experiment to see media effectiveness to KBK. The results showed that e-book multimedia is able to significantly increase the KBK of high school students in economic learning.

  18. Breakdown in ZnO Varistors by High Power Electrical Pulses; TOPICAL

    International Nuclear Information System (INIS)

    PIKE, GORDON E.

    2001-01-01

    This report documents an investigation of irreversible electrical breakdown in ZnO varistors due to short pulses of high electric field and current density. For those varistors that suffer breakdown, there is a monotonic, pulse-by-pulse degradation in the switching electric field. The electrical and structural characteristics of varistors during and after breakdown are described qualitatively and quantitatively. Once breakdown is nucleated, the degradation typically follows a well-defined relationship between the number of post-initiation pulses and the degraded switching voltage. In some cases the degraded varistor has a remnant 20(micro)m diameter hollow track showing strong evidence of once-molten ZnO. A model is developed for both electrical and thermal effects during high energy pulsing. The breakdown is assumed to start at one electrode and advance towards the other electrode as a thin filament of conductive material that grows incrementally with each successive pulse. The model is partially validated by experiments in which the varistor rod is cut at several different lengths from the electrode. Invariably one section of the cut varistor has a switching field that is not degraded while the other section(s) are heavily degraded. Based on the experiments and models of behavior during breakdown, some speculations about the nature of the nucleating mechanism are offered in the last section

  19. High-temperature nuclear reactor power plant cycle for hydrogen and electricity production – numerical analysis

    Directory of Open Access Journals (Sweden)

    Dudek Michał

    2016-01-01

    Full Text Available High temperature gas-cooled nuclear reactor (called HTR or HTGR for both electricity generation and hydrogen production is analysed. The HTR reactor because of the relatively high temperature of coolant could be combined with a steam or gas turbine, as well as with the system for heat delivery for high-temperature hydrogen production. However, the current development of HTR’s allows us to consider achievable working temperature up to 750°C. Due to this fact, industrial-scale hydrogen production using copper-chlorine (Cu-Cl thermochemical cycle is considered and compared with high-temperature electrolysis. Presented calculations show and confirm the potential of HTR’s as a future solution for hydrogen production without CO2 emission. Furthermore, integration of a hightemperature nuclear reactor with a combined cycle for electricity and hydrogen production may reach very high efficiency and could possibly lead to a significant decrease of hydrogen production costs.

  20. Impacts of High Variable Renewable Energy Futures on Wholesale Electricity Prices, and on Electric-Sector Decision Making

    OpenAIRE

    Seel, J; Mills, AD; Wiser, RH

    2018-01-01

    Increasing penetrations of variable renewable energy (VRE) can affect wholesale electricity price patterns and make them meaningfully different from past, traditional price patterns. Many long-lasting decisions for supply- and demand-side electricity infrastructure and programs are based on historical observations or assume a business-as-usual future with low shares of VRE. Our motivating question is whether certain electric-sector decisions that are made based on assumptions reflecting low V...

  1. Electric Motors. An Instructional Unit for High School Teachers of Vocational Agriculture.

    Science.gov (United States)

    Dalton, Delmer; Carpenter, Bruce

    Designed as a 3-week course of study in the agricultural mechanics curriculum to be taught at the junior or senior high school level, this unit on electric motors is divided into 11 major performance objectives. Each objective is subdivided into the areas of content, suggested teaching and learning activities, resources, and evaluation. Topics for…

  2. Charge transport in poly(p-phenylene vinylene) at low temperature and high electric field

    NARCIS (Netherlands)

    Katsouras, I.; Najafi, A.; Asadi, K.; Kronemeijer, A. J.; Oostra, A. J.; Koster, L. J. A.; de Leeuw, D. M.; Blom, P. W. M.

    Charge transport in poly(2-methoxy, 5-(2'-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV)-based hole-only diodes is investigated at high electric fields and low temperatures using a novel diode architecture. Charge carrier densities that are in the range of those in a field-effect transistor are

  3. Electrical conductivity of molten ZnCl{sub 2} at temperature as high as 1421 K

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, Alexander B.; Potapov, Alexei M. [RAS Ural Branch, Ekaterinburg. (Russian Federation) Institute of High-Temperature Electrochemistry

    2015-07-01

    The electrical conductivity of molten ZnCl{sub 2} was measured in a wide temperature range (ΔT=863 K) to a temperature as high as 1421 K that is 417 degrees above the boiling point of the salt. At the temperature maximum of the own vapor pressure of the salt reached several megapascals.

  4. Electrical resistance and magnetoresistance of UCoAl under high pressure

    Czech Academy of Sciences Publication Activity Database

    Honda, F.; Oomi, G.; Andreev, Alexander V.; Sechovský, V.; Shiokawa, Y.

    --, - (2002), s. 126-128 ISSN 0022-3131 R&D Projects: GA ČR GP202/01/D045 Institutional research plan: CEZ:AV0Z1010914 Keywords : UCoAl * non-Fermi liquid * itinerant metamagnetism * electrical resistance * high pressure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.572, year: 2002

  5. Improvements to the electrical insulation resistance of high quality magnesia insulated cables

    International Nuclear Information System (INIS)

    Mauger, R.A.; Goodings, A.

    1984-03-01

    Mineral insulated signal cables for nuclear reactor instrumentation schemes have to meet stringent electrical insulation requirements at high temperatures. This report discusses the factors which influence the attainment of this objective and the way in which it has been reached under industrial manufacturing conditions. It emphasises the importance of moisture and gives details of the improvements achieved as a result of moisture reduction. (author)

  6. Swiss pumped hydro storage potential for Germany's electricity system under high penetration of intermittent renewable energy

    NARCIS (Netherlands)

    van Meerwijk, Aagje J. H.; Benders, Reinerus; Davila-Martinez, Alejandro; Laugs, Gideon A. H.

    2016-01-01

    In order to cut greenhouse-gas emissions and increase energy security, the European Commission stimulates the deployment of intermittent renewable energy sources (IRES) towards 2050. In an electricity system with high shares of IRES implemented in the network, energy balancing like storage is needed

  7. High-efficiency electric motors: An analysis of a feasible tariff policy for Brazil

    International Nuclear Information System (INIS)

    Paiva Delgado, M.A. de; Tolmasquim, M.T.

    1997-01-01

    The main objective is to calculate an average value for an electricity tariff which will facilitate the introduction of high-efficiency electric motors in the production sector. Two computational models will be developed for technical-economic evaluation to assess economic attractiveness by calculating feasible average electricity tariffs in order to create a market for substitution of standard motors by new high-efficiency models (Purchase Decision Model) as well as to determine if retrofitting of standard installed motors by others with high-efficiency characteristics is viable, and, if so, to specify the optimum timing for such substitution (Substitution Decision Model). It should be noted that the Purchase Decision Model takes into account power factor adjustment and the Substitution Decision Model incorporates considerations as to reduction in the electromechanical performance of operating motors. Results indicate that even where average electricity tariffs are low, as in Brazil, high-efficiency motors are economically attractive compared to standard motors. There is an obvious need for complementary instruments to assist massive market penetration

  8. Electric field control methods for foil coils in high-voltage linear actuators

    NARCIS (Netherlands)

    Beek, van T.A.; Jansen, J.W.; Lomonova, E.A.

    2015-01-01

    This paper describes multiple electric field control methods for foil coils in high-voltage coreless linear actuators. The field control methods are evaluated using 2-D and 3-D boundary element methods. A comparison is presented between the field control methods and their ability to mitigate

  9. Electric devices used in radioactive handling enclosures of the high activity laboratory

    International Nuclear Information System (INIS)

    Gaigeot, F.; Laurent, H.

    1958-08-01

    This report describes several electric, electronic and electromechanical assemblies which are used in radioactive handling enclosures. The authors propose an overview of existing or foreseen devices: a device to lift covers, a brightness comparator, a high voltage device to perform electrophoresis, a level sensor or regulator device, a regulation device to control under-pressure in an enclosure [fr

  10. Electrical conductivity of molten ZnCl2 at temperature as high as 1421 K

    International Nuclear Information System (INIS)

    Salyulev, Alexander B.; Potapov, Alexei M.

    2015-01-01

    The electrical conductivity of molten ZnCl 2 was measured in a wide temperature range (ΔT=863 K) to a temperature as high as 1421 K that is 417 degrees above the boiling point of the salt. At the temperature maximum of the own vapor pressure of the salt reached several megapascals.

  11. Electrical activity of the diaphragm during nCPAP and high flow nasal cannula

    NARCIS (Netherlands)

    de Waal, C. G.; Hutten, G. J.; Kraaijenga, J. V.; de Jongh, F. H.; van Kaam, A. H.

    2017-01-01

    Objective To determine if the electrical activity of the diaphragm, as measure of neural respiratory drive and breathing effort, changes over time in preterm infants transitioned from nasal continuous positive airway pressure (nCPAP) to high flow nasal cannula (HFNC). Design Prospective

  12. A Simple Demonstration of the High-Temperature Electrical Conductivity of Glass

    Science.gov (United States)

    Chiaverina, Chris

    2014-01-01

    We usually think of glass as a good electrical insulator; this, however, is not always the case. There are several ways to show that glass becomes conducting at high temperatures, but the following approach, devised by Brown University demonstration manager Gerald Zani, may be one of the simplest to perform.

  13. Very high temperature gas-cooled reactor critical facility for Japan Atomic Energy Research Institute

    International Nuclear Information System (INIS)

    Ishihara, Noriyuki

    1985-01-01

    The outline of the critical facility, its construction, the results of the basic studies and experiments on the graphite material, and the results obtained from the test conducted on the overall functions of the critical facility were reported. With the completion of the critical facility, it has been made possible to demonstrate the establishment of the manufacturing techniques and product-quality guarantee for extremely pure isotropic graphite in addition to the reliability of the structural design and analytical techniques for the main unit of the critical facility. It is expected that the present facility will prove instrumental in the verification of the nuclear safety of the very high temperature gas-cooled nuclear reactor and in the acquisition of experimental data on the reactor physics pertaining to the improvement of the reactor characteristics. The tasks which remain to be accomplished hereafter are the improvements of the performance and quality features with regard to the oxidization of graphite, the heat-resisting structural materials, and the welded structures. (Kubozono, M.)

  14. Electric energy tariffs - critical analysis and methodological proposition; Estrutura de tarifas de energia eletrica. Analise critica e proposicoes metodologicas

    Energy Technology Data Exchange (ETDEWEB)

    Fugimoto, Sergio Kinya

    2010-07-01

    Currently, the electric energy sector is preparing for the third round of the distributors tariff revisions. Since the regulatory environment is more consolidated in terms of required revenue, the agents are turning their attention to the necessary adjustment and correction of the tariff structure. In fact, ANEEL (regulatory agency) set topics for R and D projects considered strategic for the development of national energy sector, among them, the Tariff Structure Project. Recently, the regulatory agency also announced public hearings dealing with the costs allocation, price signals and tariffs for low-voltage consumers. In line with this debate, the thesis finds to analyze the methodology for calculating tariffs, systematizing knowledge dispersed in various references. For this, it discusses the major aspects of peak pricing theory, including American, British and French approaches, and researches the connection between the logic built into the costs allocation by hour and the criteria for electricity distribution system planning. Aiming to reflect the costs of each customer type, indicating a better utilization of the distribution system, are proposed improvements and innovation whose highlights are: shifting the idea that expansion costs should be only allocated in peak time of the system, setting the periods after calculating the costs, changing how to derive the reference charges by average aggregation of the costs and applying the methodology on altered load curves. Finally, this thesis seeks to prove that the current methodology, although designed by the time in which the electricity sector was aggregated, can be adapted according to the proposed improvements and innovations, and thus applied to the current environment in which electric energy businesses and tariffs are separated in generation, transmission, and distribution and retail areas. (author)

  15. Applying Psychology to Economic Policy Design: Using Incentive Preserving Rebates to Increase Acceptance of Critical Peak Electricity Pricing

    OpenAIRE

    Letzler, Robert

    2007-01-01

    This project extends the idea that policy makers should address problems by improving economic incentives. This project adds that presenting incentives in a way that reflects how people make decisions can sometimes improve consumers’ responses to the incentives and policy outcomes. This paper uses behavioral economics to propose ways to increase electricity policy effectiveness. The cost of generating power fluctuates enormously from hour to hour but most customers pay time-invariant prices f...

  16. Microfluidic Impedance Flow Cytometry Enabling High-Throughput Single-Cell Electrical Property Characterization

    Science.gov (United States)

    Chen, Jian; Xue, Chengcheng; Zhao, Yang; Chen, Deyong; Wu, Min-Hsien; Wang, Junbo

    2015-01-01

    This article reviews recent developments in microfluidic impedance flow cytometry for high-throughput electrical property characterization of single cells. Four major perspectives of microfluidic impedance flow cytometry for single-cell characterization are included in this review: (1) early developments of microfluidic impedance flow cytometry for single-cell electrical property characterization; (2) microfluidic impedance flow cytometry with enhanced sensitivity; (3) microfluidic impedance and optical flow cytometry for single-cell analysis and (4) integrated point of care system based on microfluidic impedance flow cytometry. We examine the advantages and limitations of each technique and discuss future research opportunities from the perspectives of both technical innovation and clinical applications. PMID:25938973

  17. Electric Field Guided Assembly of One-Dimensional Nanostructures for High Performance Sensors

    Directory of Open Access Journals (Sweden)

    Wing Kam Liu

    2012-05-01

    Full Text Available Various nanowire or nanotube-based devices have been demonstrated to fulfill the anticipated future demands on sensors. To fabricate such devices, electric field-based methods have demonstrated a great potential to integrate one-dimensional nanostructures into various forms. This review paper discusses theoretical and experimental aspects of the working principles, the assembled structures, and the unique functions associated with electric field-based assembly. The challenges and opportunities of the assembly methods are addressed in conjunction with future directions toward high performance sensors.

  18. Observability in electric power networks: identification critical measures methods; Observabilidade em redes de energia eletrica: metodos de identificacao de medidas criticas

    Energy Technology Data Exchange (ETDEWEB)

    London Junior, Joao Bosco Augusto

    1997-07-01

    One of the most important functions of the control and operation centers is to maintain service reliability in a electrical power system. In order to obtain a reliable operation of the power system, it is important to identify the critical measurements, and then to improve the measurement system using pseudo measurements. The goal of this work is to determine more efficient methods for critical measurement identification. A brief review of the some methods for observability analysis as well as two methodologies to identify critical measurements are presented. The first method has a combinatorial nature; the second one is supported by uni modular M matrix (incidence matrix of measurements for branches) and A matrix (incidence matrix of branch for nodes). The second method needs a combinatorial algorithm to be feasible, so that it becomes a slow method. Two new methods for critical measurements identification are presented in this work: the first one is based on the theory developed by Bretas (1996a), to analyse observability using graph paths; the second methods is supported y the Slutsker and Scudder (1987) theory, where identification is reached throughout the analysis of the jacobian matrix. (author)

  19. Experimental observation of the inductive electric field and related plasma nonuniformity in high frequency capacitive discharge

    International Nuclear Information System (INIS)

    Ahn, S. K.; Chang, H. Y.

    2008-01-01

    To elucidate plasma nonuniformity in high frequency capacitive discharges, Langmuir probe and B-dot probe measurements were carried out in the radial direction in a cylindrical capacitive discharge driven at 90 MHz with argon pressures of 50 and 400 mTorr. Through the measurements, a significant inductive electric field (i.e., time-varying magnetic field) was observed at the radial edge, and it was found that the inductive electric field creates strong plasma nonuniformity at high pressure operation. The plasma nonuniformity at high pressure operation is physically similar to the E-H mode transition typically observed in inductive discharges. This result agrees well with the theories of electromagnetic effects in large area and/or high frequency capacitive discharges

  20. High-Lift Propeller System Configuration Selection for NASA's SCEPTOR Distributed Electric Propulsion Flight Demonstrator

    Science.gov (United States)

    Patterson, Michael D.; Derlaga, Joseph M.; Borer, Nicholas K.

    2016-01-01

    Although the primary function of propellers is typically to produce thrust, aircraft equipped with distributed electric propulsion (DEP) may utilize propellers whose main purpose is to act as a form of high-lift device. These \\high-lift propellers" can be placed upstream of wing such that, when the higher-velocity ow in the propellers' slipstreams interacts with the wing, the lift is increased. This technique is a main design feature of a new NASA advanced design project called Scalable Convergent Electric Propulsion Technology Operations Research (SCEPTOR). The goal of the SCEPTOR project is design, build, and y a DEP aircraft to demonstrate that such an aircraft can be much more ecient than conventional designs. This paper provides details into the high-lift propeller system con guration selection for the SCEPTOR ight demonstrator. The methods used in the high-lift propeller system conceptual design and the tradeo s considered in selecting the number of propellers are discussed.

  1. Exposure to electromagnetic fields aboard high-speed electric multiple unit trains.

    Science.gov (United States)

    Niu, D; Zhu, F; Qiu, R; Niu, Q

    2016-01-01

    High-speed electric multiple unit (EMU) trains generate high-frequency electric fields, low-frequency magnetic fields, and high-frequency wideband electromagnetic emissions when running. Potential human health concerns arise because the electromagnetic disturbances are transmitted mainly into the car body from windows, and from there to passengers and train staff. The transmission amount and amplitude distribution characteristics that dominate electromagnetic field emission need to be studied, and the exposure level of electromagnetic field emission to humans should be measured. We conducted a series of tests of the on board electromagnetic field distribution on several high-speed railway lines. While results showed that exposure was within permitted levels, the possibility of long-term health effects should be investigated.

  2. An analytical model for the vertical electric field distribution and optimization of high voltage REBULF LDMOS

    International Nuclear Information System (INIS)

    Hu Xia-Rong; Lü Rui

    2014-01-01

    In this paper, an analytical model for the vertical electric field distribution and optimization of a high voltage-reduced bulk field (REBULF) lateral double-diffused metal—oxide-semiconductor (LDMOS) transistor is presented. The dependences of the breakdown voltage on the buried n-layer depth, thickness, and doping concentration are discussed in detail. The REBULF criterion and the optimal vertical electric field distribution condition are derived on the basis of the optimization of the electric field distribution. The breakdown voltage of the REBULF LDMOS transistor is always higher than that of a single reduced surface field (RESURF) LDMOS transistor, and both analytical and numerical results show that it is better to make a thick n-layer buried deep into the p-substrate. (interdisciplinary physics and related areas of science and technology)

  3. Dynamic characteristics of non-ideal plasmas in an external high frequency electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adamyan, V M [Department of Theoretical Physics, I. I. Mechnikov Odessa National University, 65026 Odessa (Ukraine); Djuric, Z [Silvaco Data System, Silvaco Technology Centre, Compass Point, St. Ives PE27 5JL (United Kingdom); Mihajlov, A A [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia and Montenegro); Sakan, N M [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia and Montenegro); Tkachenko, I M [Department of Applied Mathematics, ETSII, Polytechnic University of Valencia, Camino de Vera s/n, Valencia 46022 (Spain)

    2004-07-21

    The dynamic electric conductivity, dielectric permeability and refraction and reflection coefficients of a completely ionized gaseous plasma in a high frequency (HF) external electric field are calculated. These results are obtained within the self-consistent field approach developed earlier for the static conductivity determination. The plasma electron density, N{sub e}, and temperature, T, varied within the following limits: 10{sup 19} {<=} N{sub e} {<=} 10{sup 21} cm{sup -3} and 2 x 10{sup 4} {<=} T {<=} 10{sup 6} K, respectively. The external electric field frequency, f, varied in the range 3 GHz{<=} f {<=} 0.05{omicron}{sub p}, where {omicron}{sub p} is the circular plasma frequency. Thus, the upper limit for f is either in the microwave or in the far infrared frequency band. The final results are shown in a parameterized form, suitable for laboratory applications.

  4. Dynamic characteristics of non-ideal plasmas in an external high frequency electric field

    International Nuclear Information System (INIS)

    Adamyan, V M; Djuric, Z; Mihajlov, A A; Sakan, N M; Tkachenko, I M

    2004-01-01

    The dynamic electric conductivity, dielectric permeability and refraction and reflection coefficients of a completely ionized gaseous plasma in a high frequency (HF) external electric field are calculated. These results are obtained within the self-consistent field approach developed earlier for the static conductivity determination. The plasma electron density, N e , and temperature, T, varied within the following limits: 10 19 ≤ N e ≤ 10 21 cm -3 and 2 x 10 4 ≤ T ≤ 10 6 K, respectively. The external electric field frequency, f, varied in the range 3 GHz≤ f ≤ 0.05ο p , where ο p is the circular plasma frequency. Thus, the upper limit for f is either in the microwave or in the far infrared frequency band. The final results are shown in a parameterized form, suitable for laboratory applications

  5. High Efficiency, Low Cost Parabolic Dish System for Cogeneration of Electricity and Heat

    Science.gov (United States)

    Chayet, Haim; Lozovsky, Ilan; Kost, Ori; Loeckenhoff, Ruediger; Rasch, Klaus-Dieter

    2010-10-01

    Highly efficient combined heat and power generating system based on CPV technology using unique dish design consisting of multiple simple flat mirrors mounted on a plastic parabolic surface. The dish of total aperture area of 11 m2 focuses 10.3 kWp onto a heat and electricity generating receiver. The receiver comprises a water cooled, dense triple junction cell array of 176 cm2 aperture area. A unique arrangement of the cells compensates for the non-uniformity of the reflected flux. Depending on the flow rate, the temperature of the hot water can be adjusted to suit from temperatures for domestic use, to temperatures suited for process heat. The output of 2.3 kWp electrical and 5.5 kWp thermal power from one dish system represent 20 to 21% electrical and 50% thermal conversion efficiency adding to 70% overall system efficiency.

  6. High electrical conductivity in out of plane direction of electrodeposited Bi2Te3 films

    Directory of Open Access Journals (Sweden)

    Miguel Muñoz Rojo

    2015-08-01

    Full Text Available The out of plane electrical conductivity of highly anisotropic Bi2Te3 films grown via electro-deposition process was determined using four probe current-voltage measurements performed on 4.6 - 7.2 μm thickness Bi2Te3 mesa structures with 80 - 120 μm diameters sandwiched between metallic film electrodes. A three-dimensional finite element model was used to predict the electric field distribution in the measured structures and take into account the non-uniform distribution of the current in the electrodes in the vicinity of the probes. The finite-element modeling shows that significant errors could arise in the measured film electrical conductivity if simpler one-dimensional models are employed. A high electrical conductivity of (3.2 ± 0.4 ⋅ 105 S/m is reported along the out of plane direction for Bi2Te3 films highly oriented in the [1 1 0] direction.

  7. Summary - Advanced high-temperature reactor for hydrogen and electricity production

    International Nuclear Information System (INIS)

    Forsberg, Charles W.

    2001-01-01

    Historically, the production of electricity has been assumed to be the primary application of nuclear energy. That may change. The production of hydrogen (H 2 ) may become a significant application. The technology to produce H 2 using nuclear energy imposes different requirements on the reactor, which, in turn, may require development of new types of reactors. Advanced High Temperature reactors can meet the high temperature requirements to achieve this goal. This alternative application of nuclear energy may necessitate changes in the regulatory structure

  8. Design of a low-cost system for electrical conductivity measurements of high temperature

    Science.gov (United States)

    Singh, Yadunath

    2018-05-01

    It is always a curiosity and interest among researchers working in the field of material science to know the impact of high temperature on the physical and transport properties of the materials. In this paper, we report on the design and working of a system for the measurements of electrical resistivity with high temperature. It was designed at our place and successively used for these measurements in the temperature range from room temperature to 500 ˚C.

  9. Price Forecasting of Electricity Markets in the Presence of a High Penetration of Wind Power Generators

    OpenAIRE

    Saber Talari; Miadreza Shafie-khah; Gerardo J. Osório; Fei Wang; Alireza Heidari; João P. S. Catalão

    2017-01-01

    Price forecasting plays a vital role in the day-ahead markets. Once sellers and buyers access an accurate price forecasting, managing the economic risk can be conducted appropriately through offering or bidding suitable prices. In networks with high wind power penetration, the electricity price is influenced by wind energy; therefore, price forecasting can be more complicated. This paper proposes a novel hybrid approach for price forecasting of day-ahead markets, with high penetration of wind...

  10. Dynamic Range Enhancement of High-Speed Electrical Signal Data via Non-Linear Compression

    Science.gov (United States)

    Laun, Matthew C. (Inventor)

    2016-01-01

    Systems and methods for high-speed compression of dynamic electrical signal waveforms to extend the measuring capabilities of conventional measuring devices such as oscilloscopes and high-speed data acquisition systems are discussed. Transfer function components and algorithmic transfer functions can be used to accurately measure signals that are within the frequency bandwidth but beyond the voltage range and voltage resolution capabilities of the measuring device.

  11. Computational Model for Impact-Resisting Critical Thickness of High-Speed Machine Outer Protective Plate

    Science.gov (United States)

    Wu, Huaying; Wang, Li Zhong; Wang, Yantao; Yuan, Xiaolei

    2018-05-01

    The blade or surface grinding blade of the hypervelocity grinding wheel may be damaged due to too high rotation rate of the spindle of the machine and then fly out. Its speed as a projectile may severely endanger the field persons. Critical thickness model of the protective plate of the high-speed machine is studied in this paper. For easy analysis, the shapes of the possible impact objects flying from the high-speed machine are simplified as sharp-nose model, ball-nose model and flat-nose model. Whose front ending shape to represent point, line and surface contacting. Impact analysis based on J-C model is performed for the low-carbon steel plate with different thicknesses in this paper. One critical thickness computational model for the protective plate of high-speed machine is established according to the damage characteristics of the thin plate to get relation among plate thickness and mass, shape and size and impact speed of impact object. The air cannon is used for impact test. The model accuracy is validated. This model can guide identification of the thickness of single-layer outer protective plate of a high-speed machine.

  12. High resistance to sulfur poisoning of Ni with copper skin under electric field

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaopei; Zhang, Yanxing [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Yang, Zongxian, E-mail: yzx@henannu.edu.cn [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Collaborative Innovation Center of Nano Functional Materials and Applications, Kaifeng, Henan Province (China)

    2017-02-12

    The effects of sulfur poisoning on the (1 0 0), (1 1 0) and (1 1 1) surfaces of pure Ni and Cu/Ni alloy are studied in consideration of the effect of electric field. The effects of Cu dopants on the S poisoning characteristics are analyzed by the means of the density functional theory results in combination with thermodynamics data using the ab initio atomistic thermodynamic method. When the Cu concentration increases to 50% on the surface layer of the Cu/Ni alloy, the (1 1 0) surface becomes the most vulnerable to the sulfur poisoning. Ni with a copper skin can mostly decrease the sulfur poisoning effect. Especially under the electric field of 1.0 V/Å, the sulfur adsorption and phase transition temperature can be further reduced. We therefore propose that Ni surfaces with copper skin can be very effective to improve the resistance to sulfur poisoning of the Ni anode under high electric field. - Highlights: • The electric field and Cu dopant effects on S poisoning feature of Ni are analyzed. • The present of large electric field can enhance S tolerance. • Cu dopant concentration affect the surface electronic structure of Ni. • 100% Cu doping on surface Ni layer can mostly decrease the sulfur poison.

  13. High-intensity pulsed electric field variables affecting Staphylococcus aureus inoculated in milk.

    Science.gov (United States)

    Sobrino-López, A; Raybaudi-Massilia, R; Martín-Belloso, O

    2006-10-01

    Staphylococcus aureus is an important milk-related pathogen that is inactivated by high-intensity pulsed electric fields (HIPEF). In this study, inactivation of Staph. aureus suspended in milk by HIPEF was studied using a response surface methodology, in which electric field intensity, pulse number, pulse width, pulse polarity, and the fat content of milk were the controlled variables. It was found that the fat content of milk did not significantly affect the microbial inactivation of Staph. aureus. A maximum value of 4.5 log reductions was obtained by applying 150 bipolar pulses of 8 mus each at 35 kV/cm. Bipolar pulses were more effective than those applied in the monopolar mode. An increase in electric field intensity, pulse number, or pulse width resulted in a drop in the survival fraction of Staph. aureus. Pulse widths close to 6.7 micros lead to greater microbial death with a minimum number of applied pulses. At a constant treatment time, a greater number of shorter pulses achieved better inactivation than those treatments performed at a lower number of longer pulses. The combined action of pulse number and electric field intensity followed a similar pattern, indicating that the same fraction of microbial death can be reached with different combinations of the variables. The behavior and relationship among the electrical variables suggest that the energy input of HIPEF processing might be optimized without decreasing the microbial death.

  14. Experimental investigation of piercing of high-strength steels within a critical range of slant angle

    Science.gov (United States)

    Senn, S.; Liewald, M.

    2017-09-01

    Deep drawn parts often do have complex designs and, therefore, must be trimmed or punched subsequently in a second stage. Due to the complex part geometry, most punching areas do reveal critical slant angle (angle between part surface and ram movement direction) different to perpendicular direction. Piercing within a critical range of slant angle may lead to severe damage of the cutting tool. Consequently, expensive cam units are required to transform the ram moving direction in order to perform the piercing process perpendicularly to the local part surface. For modern sheet metals, however, the described critical angle of attack has not been investigated adequately until now. Therefore, cam units are used in cases in which regular piercing with high slant angle wouldn’t be possible. Purpose of this study is to investigate influencing factors and their effect on punch damage during piercing of high strength steels with slant angles. Therefore, a modular shearing tool was designed, which allows to simply switch die parts to vary cutting clearance and cutting angle. The target size of the study is to measure the lateral deviation of the punch which is monitored by an eddy current sensor. The sensor is located in the downholder and measures the lateral punch deviation in-line during manufacturing. The deviation is mainly influenced by slant angle of workpiece surface. In relation to slang angle and sheet thickness the clearance has a small influence on the measured punch deflection.

  15. Procalcitonin increase in early identification of critically ill patients at high risk of mortality

    DEFF Research Database (Denmark)

    Jensen, Jens Ulrik; Heslet, L; Jensen, TH

    2006-01-01

    OBJECTIVE: To investigate day-by-day changes in procalcitonin and maximum obtained levels as predictors of mortality in critically ill patients. DESIGN: Prospective observational cohort study. SETTING:: Multidisciplinary intensive care unit at Rigshospitalet, Copenhagen University Hospital......, a tertiary reference hospital in Denmark. PATIENTS: Four hundred seventy-two patients with diverse comorbidity and age admitted to this intensive care unit. INTERVENTIONS: Equal in all patient groups: antimicrobial treatment adjusted according to the procalcitonin level. MEASUREMENTS AND MAIN RESULTS: Daily...... in the intensive care unit and in a 30-day follow-up period. A total of 3,642 procalcitonin measurements were evaluated in 472 critically ill patients. We found that a high maximum procalcitonin level and a procalcitonin increase for 1 day were independent predictors of 90-day all-cause mortality...

  16. Numerical solutions to the critical state in a magnet-high temperature superconductor interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Alonso, D; Coombs, T A; Campbell, A M [Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

    2005-02-01

    This paper presents an algorithm to simulate the electromagnetic behaviour of devices containing high temperature superconductors in axially symmetric problems. The numerical method is built within the finite element method. The electromagnetic properties of HTSCs are described through the critical-state model. Measurements of the axial force between a permanent magnet and a melt-textured YBCO puck are obtained in order to validate the method. This simple system is modelled so that the proposed method obtains the current distribution and electromagnetic fields in the HTSC. The forces in the interaction between the magnet and the HTSC puck can then be calculated. A comparison between experimental and simulation results shows good matching. The simplification of using the critical-state model and ignoring flux creep in this type of configuration is also explored.

  17. Interlaboratory comparison on high-temperature superconductor critical-current measurements

    International Nuclear Information System (INIS)

    Wiejaczka, J.A.; Goodrich, L.F.

    1997-01-01

    An extensive interlaboratory comparison was conducted on high temperature superconductor (HTS) critical-current measurements. This study was part of an international cooperative effort through the Versailles Project on Advanced Materials and Standards (VAMAS). The study involved six US laboratories that are recognized leaders in the field of HTS. This paper includes the complete results from this comparison of critical-current measurements on Ag-sheathed Bi 2 Sr 2 Ca 2 Cu 3 O 10-x (2223) tapes. The effects of sample characteristics, specimen mounting, measurement technique, and specimen damage were studied. The future development of a standard HTS measurement method is also discussed. Most of the evolution of this emerging technology has occurred in improvement of the performance of the conductors. The successful completion of this interlaboratory comparison is an important milestone in the evolution of HTS technology and marks a level of maturity that the technology has reached

  18. Effect of heat treatments on the tensile and electrical properties of high-strength, high-conductivity copper alloys

    International Nuclear Information System (INIS)

    Zinkle, S.J.; Eatherly, W.S.

    1997-01-01

    The unirradiated tensile properties of CuCrZr produced by two different vendors have been measured following different heat treatments. Room temperature electrical resistivity measurements were also performed in order to estimate the thermal conductivity of these specimens. The thermomechanical conditions studied included solution quenched, solution quenched and aged (ITER reference heat treatment), simulated slow HIP thermal cycle (∼1 degrees C/min cooling from solutionizing temperature) and simulated fast HIP thermal cycle (∼100 degrees C/min cooling from solutionizing temperature). Specimens from the last two heat treatments were tested in both the solution-cooled condition and after subsequent precipitate aging at 475 degrees C for 2 h. Both of the simulated HIP thermal cycles caused a pronounced decreases in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycles caused a pronounced decrease in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycle specimens, whereas the strength and conductivity following aging in the fast HIP thermal cycle improved to ∼65% of the solution quenched and aged CuCrZr values. Limited tensile and electrical resistivity measurements were also made on two new heats of Hycon 3HP CuNiBe. High strength but poor uniform and total elongations were observed at 500 degrees C on one of these new heats of CuNiBe, similar to that observed in other heats

  19. Effect of heat treatments on the tensile and electrical properties of high-strength, high-conductivity copper alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J.; Eatherly, W.S. [Oak Ridge National Lab., TN (United States)

    1997-08-01

    The unirradiated tensile properties of CuCrZr produced by two different vendors have been measured following different heat treatments. Room temperature electrical resistivity measurements were also performed in order to estimate the thermal conductivity of these specimens. The thermomechanical conditions studied included solution quenched, solution quenched and aged (ITER reference heat treatment), simulated slow HIP thermal cycle ({approximately}1{degrees}C/min cooling from solutionizing temperature) and simulated fast HIP thermal cycle ({approximately}100{degrees}C/min cooling from solutionizing temperature). Specimens from the last two heat treatments were tested in both the solution-cooled condition and after subsequent precipitate aging at 475{degrees}C for 2 h. Both of the simulated HIP thermal cycles caused a pronounced decreases in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycles caused a pronounced decrease in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycle specimens, whereas the strength and conductivity following aging in the fast HIP thermal cycle improved to {approximately}65% of the solution quenched and aged CuCrZr values. Limited tensile and electrical resistivity measurements were also made on two new heats of Hycon 3HP CuNiBe. High strength but poor uniform and total elongations were observed at 500{degrees}C on one of these new heats of CuNiBe, similar to that observed in other heats.

  20. Critical analysis of the socialist proposition to reduce the nuclear share to 50% of the electric mix by 2025

    International Nuclear Information System (INIS)

    Nifenecker, H.

    2011-01-01

    After having recalled the situation of the French energy mix in 2010, this paper analyses the consequences of the different options which can be chosen to balance a reduction of the nuclear share in this mix. These different scenarios are: replacement by fossil (gas or coal) energy plants, replacement by renewable energies (here comes a discussion of wind energy limitations), decrease of energy consumption and increase of gas-based energy production. The author also discusses a comparison between the use of a direct gas or fuel heating and the use of electricity produced by gas power plants

  1. Today's status of application of high power electron beam welding to heavy electric machinery

    International Nuclear Information System (INIS)

    Kita, Hisanao; Okuni, Tetsuo; Sejima, Itsuhiko.

    1980-01-01

    The progress in high energy welding is remarkable in recent years, and electron beam welding is now widely used in heavy industries. However, there are number of problems to be solved in the application of high power electron beam welding to ultra thick steel plates (over 100 mm). The following matters are described: the economy of high power electron beam welding; the development of the welding machines; the problems in the actual application; the instances of the welding in a high-pressure spherical gas tank, non-magnetic steel structures and high-precision welded structures; weldor training; etc. For the future rise in the capacities of heavy electric machinery, the high efficiency by high power electron beam welding will be useful. The current status is its applications to the high-precision welding of large structures with 6 m diameter and the high-quality welding of heavy structures with 160 mm thickness. (J.P.N.)

  2. Electricity Capacity Expansion Modeling, Analysis, and Visualization: A Summary of High-Renewable Modeling Experiences (Chinese Translation)

    Energy Technology Data Exchange (ETDEWEB)

    Blair, Nate [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Lab. (NREL), Golden, CO (United States); Getman, Dan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, Douglas J. [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States)

    2015-10-01

    This is the Chinese translation of NREL/TP-6A20-64831. Mathematical and computational models are widely used for the analysis and design of both physical and financial systems. Modeling the electric grid is of particular importance to China for three reasons. First, power-sector assets are expensive and long-lived, and they are critical to any country's development. China's electric load, transmission, and other energy-related infrastructure are expected to continue to grow rapidly; therefore it is crucial to understand and help plan for the future in which those assets will operate. Second, China has dramatically increased its deployment of renewable energy (RE), and is likely to continue further accelerating such deployment over the coming decades. Careful planning and assessment of the various aspects (technical, economic, social, and political) of integrating a large amount of renewables on the grid is required. Third, companies need the tools to develop a strategy for their own involvement in the power market China is now developing, and to enable a possible transition to an efficient and high RE future.

  3. Electricity Capacity Expansion Modeling, Analysis, and Visualization. A Summary of High-Renewable Modeling Experience for China

    Energy Technology Data Exchange (ETDEWEB)

    Blair, Nate [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Lab. (NREL), Golden, CO (United States); Getman, Dan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, Douglas J. [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States)

    2015-10-01

    Mathematical and computational models are widely used for the analysis and design of both physical and financial systems. Modeling the electric grid is of particular importance to China for three reasons. First, power-sector assets are expensive and long-lived, and they are critical to any country's development. China's electric load, transmission, and other energy-related infrastructure are expected to continue to grow rapidly; therefore it is crucial to understand and help plan for the future in which those assets will operate (NDRC ERI 2015). Second, China has dramatically increased its deployment of renewable energy (RE), and is likely to continue further accelerating such deployment over the coming decades. Careful planning and assessment of the various aspects (technical, economic, social, and political) of integrating a large amount of renewables on the grid is required. Third, companies need the tools to develop a strategy for their own involvement in the power market China is now developing, and to enable a possible transition to an efficient and high RE future.

  4. Anisotropy of the critical current in MgB2 tapes made of high energy milled precursor powder

    DEFF Research Database (Denmark)

    Hässler, W.; Kovac, P.; Eisterer, M.

    2010-01-01

    For applications of MgB2 wires or tapes, high critical currents in high magnetic fields are essential. By using tapes in superconducting coils the anisotropic behaviour of the critical current, i.e. the dependence on the direction of the external field in relation to the tape surface, has to be t...

  5. Effect of resin composition to the electrical and mechanical properties of high voltage insulator material

    International Nuclear Information System (INIS)

    Totok Dermawan; Elin Nuraini; Suyamto

    2012-01-01

    A solid insulator manufacture of resins for high voltage with a variation of resin and hardener composition has been made. The purpose of research to know electrical and mechanical properties of high voltage insulator material of resin. To determine its electric properties, the material is tested its breakdown voltage and the flashover voltage that occurred on the surface. While to determine the mechanical properties were tested by measuring its strength with a tensile test. From testing with variety of mixed composition it is known that for composition between hardener and resin of 1 : 800 has most advantageous properties because it has good strength with a tensile strength of 19.86 MPa and enough high dielectric strength of 43.2 kV / mm). (author)

  6. High resolution in-operando microimaging of solar cells with pulsed electrically-detected magnetic resonance

    Science.gov (United States)

    Katz, Itai; Fehr, Matthias; Schnegg, Alexander; Lips, Klaus; Blank, Aharon

    2015-02-01

    The in-operando detection and high resolution spatial imaging of paramagnetic defects, impurities, and states becomes increasingly important for understanding loss mechanisms in solid-state electronic devices. Electron spin resonance (ESR), commonly employed for observing these species, cannot meet this challenge since it suffers from limited sensitivity and spatial resolution. An alternative and much more sensitive method, called electrically-detected magnetic resonance (EDMR), detects the species through their magnetic fingerprint, which can be traced in the device's electrical current. However, until now it could not obtain high resolution images in operating electronic devices. In this work, the first spatially-resolved electrically-detected magnetic resonance images (EDMRI) of paramagnetic states in an operating real-world electronic device are provided. The presented method is based on a novel microwave pulse sequence allowing for the coherent electrical detection of spin echoes in combination with powerful pulsed magnetic-field gradients. The applicability of the method is demonstrated on a device-grade 1-μm-thick amorphous silicon (a-Si:H) solar cell and an identical device that was degraded locally by an electron beam. The degraded areas with increased concentrations of paramagnetic defects lead to a local increase in recombination that is mapped by EDMRI with ∼20-μm-scale pixel resolution. The novel approach presented here can be widely used in the nondestructive in-operando three-dimensional characterization of solid-state electronic devices with a resolution potential of less than 100 nm.

  7. The role of hydrogen in high wind energy penetration electricity systems: the Irish case

    International Nuclear Information System (INIS)

    Gonzalez, A.; McKeogh, E.; Gallachoir, B.O.

    2004-01-01

    The deployment of wind energy is constrained by wind uncontrollability, which poses operational problems on the electricity supply system at high penetration levels, lessening the value of wind-generated electricity to a significant extent. This paper studies the viability of hydrogen production via electrolysis using wind power that cannot be easily accommodated on the system. The potential benefits of hydrogen and its role in enabling a large penetration of wind energy are assessed, within the context of the enormous wind energy resource in Ireland. The exploitation of this wind resource may in the future give rise to significant amounts of surplus wind electricity, which could be used to produce hydrogen, the zero-emissions fuel that many experts believe will eventually replace fossil fuels in the transport sector. In this paper the operation of a wind powered hydrogen production system is simulated and optimised. The results reveal that, even allowing for significant cost-reductions in electrolyser and associated balance-of-plant equipment, low average surplus wind electricity cost and a high hydrogen market price are also necessary to achieve the economic viability of the technology. These conditions would facilitate the installation of electrolysis units of sufficient capacity to allow an appreciable increase in installed wind power in Ireland. The simulation model was also used to determine the CO 2 abatement potential associated with the wind energy/hydrogen production. (author)

  8. Ionospheric plasma escape by high-altitude electric fields: Magnetic moment ''pumping''

    International Nuclear Information System (INIS)

    Lundin, R.; Hultqvist, B.

    1989-01-01

    Measurements of electric fields and the composition of upward flowing ionospheric ions by the Viking spacecraft have provided further insight into the mass dependent plasma escape process taking place in the upper ionosphere. The Viking results of the temperature and mass-composition of individual ion beams suggest that upward flowing ion beams can be generated by a magnetic moment ''pumping'' mechanism caused by low-frequency transverse electric field fluctuations, in addition to a field aligned ''quasi-electrostatic'' acceleration process. Magnetic moment ''pumping'' within transverse electric field gradients can be described as a conversion of electric drift velocity to cyclotron velocity by the inertial drift in time-dependent electric field. This gives an equal cyclotron velocity gain for all plasma species, irrespective of mass. Oxygen ions thus gain 16 times as much transverse energy as protons. In addition to a transverse energy gain above the escape energy, a field-aligned quasi-electrostatic acceleration is considered primarily responsible for the collimated upward flow of ions. The field-aligned acceleration adds a constant parallel energy to escaping ionospheric ions. Thus, ion beams at high altitudes can be explained by a bimodal acceleration from both a transverse (equal velocity) and a parallel (equal energy) acceleration process. The Viking observations also show that the thermal energy of ion beams, and the ion beam width are mass dependent. The average O + /H + ''temperature ratio has been found to be 4.0 from the Viking observations. This is less than the factor of 16 anticipated from a coherent transverse electric field acceleration but greater than the factor of 1 (or even less than 1) expected from a turbulent acceleration process. copyright American Geophysical Union 1989

  9. Ultra high benefits system for electric energy saving and management of lighting energy in buildings

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2014-01-01

    Highlights: • Presenting a novel multi channel smart system to manage lighting energy in buildings. • Saving considerable electric energy which is converted to lighting in buildings. • Providing desired constant and adjustable luminance for each location in buildings. • Capability of working with all AC electric power sources. • To automatically control and manage lighting energy in buildings. - Abstract: This paper presents a smart system, including a multi channel dimmer and a central process unit (CPU) together with an exact multi channel feedback mechanism, which automatically regulates and manages lighting in buildings. Based on a multi channel luminance feedback, a high benefits technique is utilized to convert the electric energy to lighting energy. Saving a lot of the electric energy which should be converted to lighting energy in buildings, managing the lighting energy in buildings, providing desired constant and adjustable luminance for each room (location), and the capability of working with all AC electric power sources regardless of frequency and voltage amplitude are some advantages of using the proposed system and technique, thus it will be widely used in buildings. An experimental prototype of the proposed smart system has been constructed to validate the theoretical results and to carry out the experimental tests. Experimental results earned by utilizing the proposed smart system in a sample building are presented to prove the benefits of using the system. The experimental results explicitly show a considerable electric energy saving (about 27%) in the sample building while the proposed system has provided desired constant and adjustable luminance for each location of the building

  10. Benchmark criticality experiments for fast fission configuration with high enriched nuclear fuel

    International Nuclear Information System (INIS)

    Sikorin, S.N.; Mandzik, S.G.; Polazau, S.A.; Hryharovich, T.K.; Damarad, Y.V.; Palahina, Y.A.

    2014-01-01

    Benchmark criticality experiments of fast heterogeneous configuration with high enriched uranium (HEU) nuclear fuel were performed using the 'Giacint' critical assembly of the Joint Institute for Power and Nuclear Research - Sosny (JIPNR-Sosny) of the National Academy of Sciences of Belarus. The critical assembly core comprised fuel assemblies without a casing for the 34.8 mm wrench. Fuel assemblies contain 19 fuel rods of two types. The first type is metal uranium fuel rods with 90% enrichment by U-235; the second one is dioxide uranium fuel rods with 36% enrichment by U-235. The total fuel rods length is 620 mm, and the active fuel length is 500 mm. The outer fuel rods diameter is 7 mm, the wall is 0.2 mm thick, and the fuel material diameter is 6.4 mm. The clad material is stainless steel. The side radial reflector: the inner layer of beryllium, and the outer layer of stainless steel. The top and bottom axial reflectors are of stainless steel. The analysis of the experimental results obtained from these benchmark experiments by developing detailed calculation models and performing simulations for the different experiments is presented. The sensitivity of the obtained results for the material specifications and the modeling details were examined. The analyses used the MCNP and MCU computer programs. This paper presents the experimental and analytical results. (authors)

  11. Magnetocaloric properties and critical behavior of high relative cooling power FeNiB nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, V. [Interdisciplinary Graduate School, Nanyang Technological University, Singapore 639798 (Singapore); Energy Research Institute @NTU, Nanyang Technological University, Singapore 637553 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Maheswar Repaka, D. V.; Chaturvedi, A.; Ramanujan, R. V., E-mail: ramanujan@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Sridhar, I. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2014-10-28

    Low cost magnetocaloric nanomaterials have attracted considerable attention for energy efficient applications. We report a very high relative cooling power (RCP) in a study of the magnetocaloric effect in quenched FeNiB nanoparticles. RCP increases from 89.8 to 640 J kg{sup −1} for a field change of 1 and 5 T, respectively, these values are the largest for rare earth free iron based magnetocaloric nanomaterials. To investigate the magnetocaloric behavior around the Curie temperature (T{sub C}), the critical behavior of these quenched nanoparticles was studied. Detailed analysis of the magnetic phase transition using the modified Arrott plot, Kouvel-Fisher method, and critical isotherm plots yields critical exponents of β = 0.364, γ = 1.319, δ = 4.623, and α = −0.055, which are close to the theoretical exponents obtained from the 3D-Heisenberg model. Our results indicate that these FeNiB nanoparticles are potential candidates for magnetocaloric fluid based heat pumps and low grade waste heat recovery.

  12. Calculational study of benchmark critical experiments on high-enriched uranyl nitrate solution systems

    International Nuclear Information System (INIS)

    Oh, I.; Rothe, R.E.

    1978-01-01

    Criticality calculations on minimally reflected, concrete-reflected, and plastic-reflected single tanks and on arrays of cylinders reflected by concrete and plastic have been performed using the KENO-IV code with 16-group Hansen-Roach neutron cross sections. The fissile material was high-enriched (93.17% 235 U) uranyl nitrate [UO 2 (NO 3 ) 2 ] solution. Calculated results are compared with those from a benchmark critical experiments program to provide the best possible verification of the calculational technique. The calculated k/sub eff/'s underestimate the critical condition by an average of 1.28% for the minimally reflected single tanks, 1.09% for the concrete-reflected single tanks, 0.60% for the plastic-reflected single tanks, 0.75% for the concrete-reflected arrays of cylinders, and 0.51% for the plastic-reflected arrays of cylinders. More than half of the present comparisons were within 1% of the experimental values, and the worst calculational and experimental discrepancy was 2.3% in k/sub eff/ for the KENO calculations

  13. High critical currents in heavily doped (Gd,Y)Ba2Cu3Ox superconductor tapes

    Energy Technology Data Exchange (ETDEWEB)

    Selvamanickam, V; Gharahcheshmeh, MH; Xu, A; Galstyan, E; Delgado, L; Cantoni, C

    2015-01-19

    REBa2Cu3Ox ((REBCO), RE = rare earth) superconductor tapes with moderate levels of dopants have been optimized for high critical current density in low magnetic fields at 77 K, but they do not exhibit exemplary performance in conditions of interest for practical applications, i.e., temperatures less than 50K and fields of 2-30 T. Heavy doping of REBCO tapes has been avoided by researchers thus far due to deterioration in properties. Here, we report achievement of critical current densities (J(c)) above 20 MA/cm(2) at 30 K, 3 T in heavily doped (25 mol.% Zr-added) (Gd,Y)Ba2Cu3Ox superconductor tapes, which is more than three times higher than the J(c) typically obtained in moderately doped tapes. Pinning force levels above 1000 GN/m(3) have also been attained at 20 K. A composition map of lift factor in J(c) (ratio of J(c) at 30 K, 3 T to the J(c) at 77 K, 0 T) has been developed which reveals the optimum film composition to obtain lift factors above six, which is thrice the typical value. A highly c-axis aligned BaZrO3 (BZO) nanocolumn defect density of nearly 7 x 10(11) cm(-2) as well as 2-3 nm sized particles rich in Cu and Zr have been found in the high J(c) films. (C) 2015 AIP Publishing LLC.

  14. High critical current density YBCO films and fabrication of dc-SQUIDs

    CERN Document Server

    Kuriki, S; Kawaguchi, Y; Matsuda, M; Otowa, T

    2002-01-01

    In order to improve the sensitivity of SQUID magnetometers made of high-T sub c films, we have studied the conditions of pulsed-laser deposition of YBCO films. Among the different deposition parameters examined, extensive degassing of the vacuum chamber before and precise control of the substrate temperature during the film deposition were found effective for obtaining high critical temperature T sub c and high critical current density J sub c. It was also found that the residual-resistance ratio has a clear correlation with J sub c , indicating that it can be a good, and easy to measure, index of the film quality. Films having T sub c approx 89-90 K and J sub c >= 5x10 sup 6 A cm sup - sup 2 at 77 K were used to fabricate SQUIDs without a pickup loop. Grain-boundary junctions formed on bicrystal substrates with a 30 deg. misorientation angle exhibited I sub c R sub n values of more than 100 mu V at 77 K. The well-known scaling behaviour of the relation I sub c R sub n propor to (J sup G sup B sub c) sup 1 su...

  15. Critical pathogenic steps to high risk Helicobacter pylori gastritis and gastric carcinogenesis.

    Science.gov (United States)

    Lee, Inchul

    2014-06-07

    Helicobacter pylori (H. pylori) gastritis may progress to high risk gastropathy and cancer. However, the pathological progression has not been characterized in detail. H. pylori induce persistent inflammatory infiltration. Neutrophils are unique in that they directly infiltrate into foveolar epithelium aiming the proliferative zone specifically. Neutrophilic proliferative zone foveolitis is a critical pathogenic step in H. pylori gastritis inducing intensive epithelial damage. Epithelial cells carrying accumulated genomic damage and mutations show the Malgun (clear) cell change, characterized by large clear nucleus and prominent nucleolus. Malgun cells further undergo atypical changes, showing nuclear folding, coarse chromatin, and multiple nucleoli. The atypical Malgun cell (AMC) change is a novel premalignant condition in high risk gastropathy, which may progress and undergo malignant transformation directly. The pathobiological significance of AMC in gastric carcinogenesis is reviewed. A new diagnosis system of gastritis is proposed based on the critical pathologic steps classifying low and high risk gastritis for separate treatment modality. It is suggested that the regulation of H. pylori-induced neutrophilic foveolitis might be a future therapeutic goal replacing bactericidal antibiotics approach.

  16. Critical current density and wire fabrication of high-TC superconductors

    International Nuclear Information System (INIS)

    Schlabach, T.D.; Jin, S.; Sherwood, R.C.; Tiefel, T.H.

    1989-01-01

    In this paper, some of the recent investigations of wire fabrication techniques and critical current behavior in high T c superconductors will be reviewed. In spite of the tremendous interest and research effort, the progress toward major applications of the bulk high-temperature superconductors has been impeded by, among other thins, the low critical currents and their severe deterioration in weak magnetic fields. Significant advances, however, have been made in understanding the causes of the problem as well as in improving the current-carrying capacity through proper microstructural control such as the melt-textured-growth in Y-Ba-Cu-O. The low density of effective flux-pinning sites in bulk Y-Ba-Cu-O limits J c at 77K in high magnetic fields to about 10 4 A/cm 2 even in the absence of weak links. Magnetization measurements on Bi-Sr-Ca-Cu-O and Tl-Ba-Ca-Cu-O at 77K by various researchers indicate even weaker flux pinning capabilities in these materials than in Y-Ba-Cu-O. The challenge in the future is to obtain suitable flux-pinning defects by choosing the right processing and chemistry changes

  17. Nursing care in a high-technological environment: Experiences of critical care nurses.

    Science.gov (United States)

    Tunlind, Adam; Granström, John; Engström, Åsa

    2015-04-01

    Management of technical equipment, such as ventilators, infusion pumps, monitors and dialysis, makes health care in an intensive care setting more complex. Technology can be defined as items, machinery and equipment that are connected to knowledge and management to maximise efficiency. Technology is not only the equipment itself, but also the knowledge of how to use it and the ability to convert it into nursing care. The aim of this study is to describe critical care nurses' experience of performing nursing care in a high technology healthcare environment. Qualitative, personal interviews were conducted during 2012 with eight critical care nurses in the northern part of Sweden. Interview transcripts were analysed using qualitative content analysis. Three themes with six categories emerged. The technology was described as a security that could facilitate nursing care, but also one that could sometimes present obstacles. The importance of using the clinical gaze was highlighted. Nursing care in a high technological environment must be seen as multi-faceted when it comes to how it affects CCNs' experience. The advanced care conducted in an ICU could not function without high-tech equipment, nor could care operate without skilled interpersonal interaction and maintenance of basal nursing. That technology is seen as a major tool and simultaneously as a barrier to patient-centred care. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Effect of high-hydrostatic pressure and moderate-intensity pulsed electric field on plum.

    Science.gov (United States)

    García-Parra, J; González-Cebrino, F; Delgado-Adámez, J; Cava, R; Martín-Belloso, O; Élez-Martínez, P; Ramírez, R

    2018-03-01

    Moderate intensity pulse electric fields were applied in plum with the aim to increase bioactive compounds content of the fruit, while high-hydrostatic pressure was applied to preserve the purées. High-hydrostatic pressure treatment was compared with an equivalent thermal treatment. The addition of ascorbic acid during purée manufacture was also evaluated. The main objective of this study was to assess the effects on microorganisms, polyphenoloxidase, color and bioactive compounds of high-hydrostatic pressure, or thermal-processed plum purées made of moderate intensity pulse electric field-treated or no-moderate intensity pulse electric field-treated plums, after processing during storage. The application of moderate intensity pulse electric field to plums slightly increased the levels of anthocyanins and the antioxidant activity of purées. The application of Hydrostatic-high pressure (HHP) increased the levels of bioactive compounds in purées, while the thermal treatment preserved better the color during storage. The addition of ascorbic acid during the manufacture of plum purée was an important factor for the final quality of purées. The color and the bioactive compounds content were better preserved in purées with ascorbic acid. The no inactivation of polyphenoloxidase enzyme with treatments applied in this study affected the stability purées. Probably more intense treatments conditions (high-hydrostatic pressure and thermal treatment) would be necessary to reach better quality and shelf life during storage.

  19. Development of Bi-based high critical current density superconducting tapes

    International Nuclear Information System (INIS)

    Swaminathan, G.

    1995-01-01

    In order to achieve the aim of developing suitable superconducting materials the main emphasis has to be made in the following areas viz., synthesizing powders, detailed study of sintering and phase conversion process in relation to the critical current density (J c ) on pellets and optimising of tape processing parameters. The bismuth system has been found to be more favourable for making wires and tapes because of its high transition temperature, good stability, does not require oxygen on cooling and is non-toxic. These have been the most convenient properties which made the BiSCO material the most popular one

  20. Magnus effects at high angles of attack and critical Reynolds numbers

    Science.gov (United States)

    Seginer, A.; Ringel, M.

    1983-01-01

    The Magnus force and moment experienced by a yawed, spinning cylinder were studied experimentally in low speed and subsonic flows at high angles of attack and critical Reynolds numbers. Flow-field visualization aided in describing a flow model that divides the Magnus phenomenon into a subcritical region, where reverse Magnus loads are experienced, and a supercritical region where these loads are not encountered. The roles of the spin rate, angle of attack, and crossflow Reynolds number in determining the boundaries of the subcritical region and the variations of the Magnus loads were studied.

  1. High-Surface-Area Nitrogen-Doped Reduced Graphene Oxide for Electric Double-Layer Capacitors.

    Science.gov (United States)

    Youn, Hee-Chang; Bak, Seong-Min; Kim, Myeong-Seong; Jaye, Cherno; Fischer, Daniel A; Lee, Chang-Wook; Yang, Xiao-Qing; Roh, Kwang Chul; Kim, Kwang-Bum

    2015-06-08

    A two-step method consisting of solid-state microwave irradiation and heat treatment under NH3 gas was used to prepare nitrogen-doped reduced graphene oxide (N-RGO) with a high specific surface area (1007 m(2)  g(-1) ), high electrical conductivity (1532 S m(-1) ), and low oxygen content (1.5 wt %) for electrical double-layer capacitor applications. The specific capacitance of N-RGO was 291 F g(-1) at a current density of 1 A g(-1) , and a capacitance of 261 F g(-1) was retained at 50 A g(-1) , which indicated a very good rate capability. N-RGO also showed excellent cycling stability and preserved 96 % of the initial specific capacitance after 100 000 cycles. Near-edge X-ray absorption fine-structure spectroscopy results provided evidenced for the recovery of π conjugation in the carbon networks with the removal of oxygenated groups and revealed chemical bonding of the nitrogen atoms in N-RGO. The good electrochemical performance of N-RGO is attributed to its high surface area, high electrical conductivity, and low oxygen content. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Nanostructure design for drastic reduction of thermal conductivity while preserving high electrical conductivity.

    Science.gov (United States)

    Nakamura, Yoshiaki

    2018-01-01

    The design and fabrication of nanostructured materials to control both thermal and electrical properties are demonstrated for high-performance thermoelectric conversion. We have focused on silicon (Si) because it is an environmentally friendly and ubiquitous element. High bulk thermal conductivity of Si limits its potential as a thermoelectric material. The thermal conductivity of Si has been reduced by introducing grains, or wires, yet a further reduction is required while retaining a high electrical conductivity. We have designed two different nanostructures for this purpose. One structure is connected Si nanodots (NDs) with the same crystal orientation. The phonons scattering at the interfaces of these NDs occurred and it depended on the ND size. As a result of phonon scattering, the thermal conductivity of this nanostructured material was below/close to the amorphous limit. The other structure is Si films containing epitaxially grown Ge NDs. The Si layer imparted high electrical conductivity, while the Ge NDs served as phonon scattering bodies reducing thermal conductivity drastically. This work gives a methodology for the independent control of electron and phonon transport using nanostructured materials. This can bring the realization of thermoelectric Si-based materials that are compatible with large scale integrated circuit processing technologies.

  3. Critical review of the methods for monitoring of lithium-ion batteries in electric and hybrid vehicles

    Science.gov (United States)

    Waag, Wladislaw; Fleischer, Christian; Sauer, Dirk Uwe

    2014-07-01

    Lithium-ion battery packs in hybrid and pure electric vehicles are always equipped with a battery management system (BMS). The BMS consists of hardware and software for battery management including, among others, algorithms determining battery states. The continuous determination of battery states during operation is called battery monitoring. In this paper, the methods for monitoring of the battery state of charge, capacity, impedance parameters, available power, state of health, and remaining useful life are reviewed with the focus on elaboration of their strengths and weaknesses for the use in on-line BMS applications. To this end, more than 350 sources including scientific and technical literature are studied and the respective approaches are classified in various groups.

  4. Vibration of high-voltage electric machines with rotors on rolling bearings

    Science.gov (United States)

    Shekyan, H. G.; Gevorgyan, A. V.

    2018-04-01

    The paper presents an investigation of vibrational activity of electric machines due to high-harmonic vibrational loadings. It is shown that the vibrational loadings experienced by bearings may result in the interruption of their normal operation and even take them out of action. Therefore, the values of the vibrational speed-up leading to high harmonics are factors determining the admissible dynamic loading on the bearings. In the paper, an attempt is made to consider the factors which result in origination of high harmonics and to illustrate methods for their smoothing.

  5. Feasibility study of electric motors constructed with high temperature superconducting materials

    International Nuclear Information System (INIS)

    Jordan, H.E.

    1989-01-01

    The potential application of high temperature superconducting (HTSC) materials to electric motors is discussed. The specific application area of motors in electric power generating stations has been selected and a feasible study has been initiated on the use of HTSC materials in the design of motors for this application. A progress report on this feasibility study is presented. Technical challenges in both the development of HTSC wire and the design of a motor to utilize this wire are discussed. Finally, the results of design calculations comparing a superconducting motor with one of conventional design are presented assuming that success can be achieved in overcoming the technical problems which must be resolved to produce a high performance HTSC wire

  6. Electrically Conductive TPU Nanofibrous Composite with High Stretchability for Flexible Strain Sensor

    Science.gov (United States)

    Tong, Lu; Wang, Xiao-Xiong; He, Xiao-Xiao; Nie, Guang-Di; Zhang, Jun; Zhang, Bin; Guo, Wen-Zhe; Long, Yun-Ze

    2018-03-01

    Highly stretchable and electrically conductive thermoplastic polyurethane (TPU) nanofibrous composite based on electrospinning for flexible strain sensor and stretchable conductor has been fabricated via in situ polymerization of polyaniline (PANI) on TPU nanofibrous membrane. The PANI/TPU membrane-based sensor could detect a strain from 0 to 160% with fast response and excellent stability. Meanwhile, the TPU composite has good stability and durability. Besides, the composite could be adapted to various non-flat working environments and could maintain opportune conductivity at different operating temperatures. This work provides an easy operating and low-cost method to fabricate highly stretchable and electrically conductive nanofibrous membrane, which could be applied to detect quick and tiny human actions.

  7. A highly efficient electric additive for enhancing photovoltaic performance of dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    N-cetylpyridinium iodide (N-CPI) as a new electric additive for enhancing photovoltaic performance of the dye-sensitized solar cell (DSSC) was studied.It showed high efficiency for enhancing both the open-circuit voltage and the short-circuit current density of DSSC when the suitable amount of N-CPI as 0.02 M was added in liquid electrolyte.The energy conversion effi- ciency of DSSC increased from 4.429% to 6.535%,with 47.55% enhancement.Therefore,it is a highly efficient electric addi- tive for DSSC.The intrinsic reason is owing to the special molecular structure of N-CPI,which contains two different polarity groups.As a surfactant,N-CPI could form ordered arrangement in liquid electrolyte,which affects the diffusing ability and the redox reaction of I-/I3-,and further affects the photovoltaic performance of DSSC.

  8. A micro-structured Si-based electrodes for high capacity electrical double layer capacitors

    International Nuclear Information System (INIS)

    Krikscikas, Valdas; Oguchi, Hiroyuki; Hara, Motoaki; Kuwano, Hiroki; Yanazawa, Hiroshi

    2014-01-01

    We challenged to make basis for Si electrodes of electric double layer capacitors (EDLC) used as a power source of micro-sensor nodes. Mcroelectromechanical systems (MEMS) processes were successfully introduced to fabricate micro-structured Si-based electrodes to obtain high surface area which leads to high capacity of EDLCs. Study of fundamental properties revealed that the microstructured electrodes benefit from good wettability to electrolytes, but suffer from electric resistance. We found that this problem can be solved by metal-coating of the electrode surface. Finally we build an EDLC consisting of Au-coated micro-structured Si electrodes. This EDLC showed capacity of 14.3 mF/cm 2 , which is about 530 times larger than that of an EDLC consisting of flat Au electrodes

  9. The effect of high voltage pulsed electric field on water molecular

    Science.gov (United States)

    Fan, Xuejie; Bai, Yaxiang; Ren, Ziying

    2017-10-01

    In order to study the mechanism of high voltage pulsed electric field pre-treatment on the food drying technology. In this paper, water was treated with high pulse electric field (HPEF) in different frequency, and different voltage, then, the viscosity coefficient and the surface tension coefficient of the water were measured. The results showed that indicated that the viscosity coefficient and the surface tension coefficient of the treated water can be decreased, and while HPEF pre-treatment was applied for 22.5kV at a frequency of 50Hz and 70 Hz, the surface tension and the viscosity coefficient of the pre-treatment treatment were reduced 13.1% and 7.5%, respectively.

  10. Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

    Science.gov (United States)

    Muller, Leah; Rolston, John D.; Fox, Neal P.; Knowlton, Robert; Rao, Vikram R.; Chang, Edward F.

    2018-04-01

    Objective. Direct electrical stimulation (DES) is a clinical gold standard for human brain mapping and readily evokes conscious percepts, yet the neurophysiological changes underlying these percepts are not well understood. Approach. To determine the neural correlates of DES, we stimulated the somatosensory cortex of ten human participants at frequency-amplitude combinations that both elicited and failed to elicit conscious percepts, meanwhile recording neural activity directly surrounding the stimulation site. We then compared the neural activity of perceived trials to that of non-perceived trials. Main results. We found that stimulation evokes distributed high gamma activity, which correlates with conscious perception better than stimulation parameters themselves. Significance. Our findings suggest that high gamma activity is a reliable biomarker for perception evoked by both natural and electrical stimuli.

  11. Methodological aspects of functional neuroimaging at high field strength: a critical review

    International Nuclear Information System (INIS)

    Scheef, L.; Landsberg, M.W.; Boecker, H.

    2007-01-01

    The last few years have proven that high field magnetic resonance imaging (MRI) is superior in nearly every way to conventional equipment up to 1.5 tesla (T). Following the global success of 3T-scanners in research institutes and medical practices, a new generation of MRI devices with field strengths of 7T and higher is now on the horizon. The introduction of ultra high fields has brought MRI technology closer to the physical limitations and increasingly greater costs are required to achieve this goal. This article provides a critical overview of the advantages and problems of functional neuroimaging using ultra high field strengths. This review is principally limited to T2*-based functional imaging techniques not dependent on contrast agents. The main issues include the significance of high field technology with respect to SNR, CNR, resolution, and sequences, as well as artifacts, noise exposure, and SAR. Of great relevance is the discussion of parallel imaging, which will presumably determine the further development of high and ultra high field strengths. Finally, the importance of high field strengths for functional neuroimaging is explained by selected publications. (orig.)

  12. Structural and electrical properties of TmTe under high pressure

    International Nuclear Information System (INIS)

    Tang, Jie; Matsumoto, Takehiko; Kosaka, Takayuki; Matsumura, Takeshi; Suzuki, Takashi; Mori, Nobuo

    1997-01-01

    Pressure-induced valence state of Tm ions in TmTe has been investigated by measurements of electrical resistivity in situ x-ray diffraction and magnetic susceptibility at high pressure. Below 2 GPa, the valence of Tm was confirmed to be 2 + from the results of compressibility and magnetic susceptibility. The pressure dependence of the electrical resistivity up to 2 GPa at room temperature showed an exponential decrease, indicating a linear closing of the energy gap at a rate of -1 meV/GPa. In the pressure range above 2 GPa where the energy gap disappeared, the valence transition from Tm 2+ to Tm 3+ was concluded from the pressure dependence of the lattice parameters. The electrical resistivity showing a logarithmic temperature dependence was reminiscent of Kondo effect. Above 6 GPa at which the pressure dependence of electrical resistivity abruptly decreased, the structure was confirmed to transform from the NaCl-type with Tm 3+ to a tetragonal structure. (author)

  13. Development of MgB2 superconductor wire with high critical current

    International Nuclear Information System (INIS)

    Kim, Chan Joong; Jun, Byung Hyuk; Park, Soon Dong; Kim, Nam Kyu; Kim, Yi Jeong; Yi, Ji Hye; Lee, Ji Hyun; Tan, Kai Sin

    2009-07-01

    The MgB 2 superconductor with smaller grain size could improve its critical properties by providing flux pinning centers with high grain boundary density. The effects of C doping such as charcoal, paper ash and glycerin on the superconducting properties was investigated for in situ processed MgB 2 samples using low purity semi-crystalline B powder. The results show a decrease in Tc and an enhancement of Jc at high fields for the C-doped samples as compared to the un-doped samples. A combined process of a mechanical ball milling and liquid glycerin (C 3 H 8 O 3 ) treatment of B powder has been conducted to enhance the superconducting properties of MgB 2 . The mechanical ball milling was effective for grain refinement, and a lattice disorder was easily achieved by glycerin addition. With the combined process, the critical properties was further increased due to a higher grain boundary density and a greater C substitution. To get fine grain structure of MgB 2 with high critical current properties, mechanical milling for as-received B powder and low temperature solid-state reaction of 550 or 600 .deg. C were attempted to in situ powder-in-tube processed MgB 2 /Fe wires. The critical current properties of the MgB 2 wires using the milled B powder were enhanced due to a smaller grain size and an increased volume of the superconducting phase. The solid-state reaction of a low temperature process for the samples using the milled B powder resulted in a poorer crystallinity with a smaller grain size, which improved superconducting properties. We established the system to measure the transport current properties of the MgB 2 wires. The field dependence of the transport Jc was evaluated for the MgB 2 wires heat-treated at different heat treatment conditions using ball-milled and glycerin-treated B powder. The MgB 2 magnet was developed and the AC loss of MgB 2 wire was also investigated. A conduction cooling device to cool the MgB 2 coil down to 4 K has been fabricated and the

  14. Electric Vehicles for Improved Operation of Power Systems with High Wind Power Penetration

    OpenAIRE

    Larsen, Esben; Chandrashekhara, Divya K; Østergaard, Jacob

    2008-01-01

    In a power system with a high share of wind energy the wind fluctuation causes a variation in the power generation, which must be compensated from other sources. The situation in Denmark with a penetration of more than 20% wind in yearly average is presented. The introduction of electric drive vehicles (EDV) as flexible loads can improve the system operation. Bidirectional power exchange through batteries (vehicle to grid) can be seen as a storage system in the grid. An analysis of possible e...

  15. Preparation of Fe-Pt perpendicular double-layered media with high electric resistivity backlayer

    International Nuclear Information System (INIS)

    Uchida, Masaru; Suzuki, Toshio; Ouchi, Kazuhiro

    2001-01-01

    High electric resistivity materials, oxide-added Fe-Si, were investigated as a soft-magnetic backlayer for Fe-Pt perpendicular double-layered media. It was found that there is a possibility of using (Fe-Si)-MgO as a backlayer. To promote a hetero-epitaxial growth of ordered Fe-Pt FCT(0 0 1), the backlayer needed a BCC(2 0 0) crystal orientation, in a situation where surface topology also played an important role

  16. Tunneling emission of electrons from semiconductors' valence bands in high electric fields

    International Nuclear Information System (INIS)

    Kalganov, V. D.; Mileshkina, N. V.; Ostroumova, E. V.

    2006-01-01

    Tunneling emission currents of electrons from semiconductors to vacuum (needle-shaped GaAs photodetectors) and to a metal (silicon metal-insulator-semiconductor diodes with a tunneling-transparent insulator layer) are studied in high and ultrahigh electric fields. It is shown that, in semiconductors with the n-type conductivity, the major contribution to the emission current is made by the tunneling emission of electrons from the valence band of the semiconductor, rather than from the conduction band

  17. High uniformity magnetic coil for search of neutron electric dipole moment

    Energy Technology Data Exchange (ETDEWEB)

    Perez Galvan, A., E-mail: apg@caltech.edu [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA, 91125 (United States); Plaster, B. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY, 40506 (United States); Boissevain, J.; Carr, R.; Filippone, B.W.; Mendenhall, M.P.; Schmid, R. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA, 91125 (United States); Alarcon, R.; Balascuta, S. [Department of Physics, Arizona State University, Tempe, AZ 85287 (United States)

    2011-12-21

    We present in this article a prototype magnetic coil that has been developed for a new search for the electric dipole moment of the neutron at the Spallation Neutron Source at Oak Ridge National Laboratory. The gradients of the magnetic field generated by the coil have been optimized to reduce known systematic effects and to yield long polarization lifetimes of the trapped particles sampling the highly uniform magnetic field. Measurements of the field uniformity of this prototype magnetic coil are also presented.

  18. "Train surfers": analysis of 23 cases of electrical burns caused by high tension railway overhead cables.

    Science.gov (United States)

    Sternick, I; Gomes, R D; Serra, M C; Radwanski, H N; Pitanguy, I

    2000-08-01

    The term "train surfers" describes a group of adolescents from the outskirts of the city of Rio de Janeiro, who are compelled by the overcrowded railway trains to travel on the roofs of the wagons. Collision with electrical high-tension wires is a relatively frequent occurrence, causing extensive and complex injuries. This study analyzes this clinical and surgical phenomenon which has caused over 100 fatalities in more than 200 registered accidents over the past 10 years.

  19. Linezolid extracorporeal removal during haemodialysis with high cut-off membrane in critically ill patients.

    Science.gov (United States)

    Villa, Gianluca; Cassetta, Maria Iris; Tofani, Lorenzo; Valente, Serafina; Chelazzi, Cosimo; Falsini, Silvia; De Gaudio, Angelo Raffaele; Novelli, Andrea; Ronco, Claudio; Adembri, Chiara

    2015-10-01

    Continuous venovenous haemodialysis with high cut-off membrane (HCO-CVVHD) is often used in critically ill septic patients with acute kidney injury (AKI) to sustain renal function and to remove circulating inflammatory mediators. The aim of this study was to analyse the extracorporeal removal of linezolid and related alterations in pharmacokinetic/pharmacodynamic (PK/PD) parameters during HCO-CVVHD. Three critically ill septic patients with AKI, treated with linezolid and HCO-CVVHD, were prospectively observed. To calculate the extracorporeal clearance of linezolid and the PK parameters, effluent, pre-filter and post-filter samples were contemporaneously collected before linezolid infusion, just after 1-h infusion (maximum serum concentration; C(max)), at 3 h and 6 h after dosing, and before the next dose (trough serum concentration; C(min)). Linezolid C(max) and C(min) (pre-filter) ranged from 10.4-23.5 mg/L and from 2.9-10.3 mg/L. The dialysate saturation coefficient was 0.66-0.85 and the extracorporeal clearance with a diffusive dose of 35 m L/kg/h ranged from 2.1-2.5 L/h. Total linezolid clearance was between 1.7 L/h and 6.3 L/h. The total area under the plasma concentration-time curve (AUC0-∞) ranged from 95.1 mgh/L to 352.9 mgh/L, in accordance with the different clinical conditions. AUCfree/MIC ratios were always linezolid total clearance, the clinical features of critically ill septic patients appear to be mainly responsible for the high variability of linezolid serum concentrations. Copyright © 2015. Published by Elsevier B.V.

  20. A new contact electric resistance technique for in-situ measurement of the electric resistance of surface films on metals in electrolytes at high temperatures and pressures

    International Nuclear Information System (INIS)

    Saario, T.; Marichev, V.A.

    1993-01-01

    Surface films play a major role in corrosion assisted cracking. A new Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films. The method has been upgraded for high temperature high pressure application. The technique can be used for any electrically conductive material in any environment including liquid, gas or vacuum. The technique has been used to determine in situ the electric resistance of films on metals during adsorption of water and anions, formation and destruction of oxides and hydrides, electroplating of metals and to study the electric resistance of films on semiconductors. The resolution of the CER technique is 10 -9 Ω, which corresponds to about 0.03 monolayers of deposited copper during electrochemical deposition Cu/Cu 2+ . Electric resistance data can be measured with a frequency of the order of one hertz, which enables one to follow in situ the kinetics of surface film related processes. The kinetics of these processes and their dependence on the environment, temperature, pH and electrochemical potential can be investigated

  1. Electric fields, Joule and particle heating in the high latitude thermosphere. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Brekke, A [Auroral Observatory, Tromsoe (Norway)

    1976-08-01

    A short review of the recent high latitude measurements of ionospheric electric fields is given. The importance of investigating large-scale and slowly-varying electric fields in order to study magnetospheric convection is stressed. The motion of such high energetic phenomena as auroral forms and spread E-region echoes must be treated by extreme caution when interpreted as a manifestation of convection motion. The relationship between the ionospheric source and polarization field is still an unanswered problem. It is indicated that progress can be made in this respect when electric fields and conductivities are measured simultaneously in the ionosphere. Evidence is shown at one occasion that the meridional component during an auroral sunstorm might be mainly a polarization field. The height-integrated Joule heating rate is occasionally found to be far larger than the solar radiation input at auroral altitudes. The presence of this additional heat source at any time of day is expected to have a strong impact on the global-scale atmospheric dynamics. From comparisons made between Joule and particle heating it appears that the two components are comparable. It is expected that high latitude incoherent radars will contribute substantially to the understanding of these phenomena in the near future.

  2. Edge-enriched, porous carbon-based, high energy density supercapacitors for hybrid electric vehicles.

    Science.gov (United States)

    Kim, Yong Jung; Yang, Cheol-Min; Park, Ki Chul; Kaneko, Katsumi; Kim, Yoong Ahm; Noguchi, Minoru; Fujino, Takeshi; Oyama, Shigeki; Endo, Morinobu

    2012-03-12

    Supercapacitors can store and deliver energy by a simple charge separation, and thus they could be an attractive option to meet transient high energy density in operating fuel cells and in electric and hybrid electric vehicles. To achieve such requirements, intensive studies have been carried out to improve the volumetric capacitance in supercapacitors using various types and forms of carbons including carbon nanotubes and graphenes. However, conventional porous carbons are not suitable for use as electrode material in supercapacitors for such high energy density applications. Here, we show that edge-enriched porous carbons are the best electrode material for high energy density supercapacitors to be used in vehicles as an auxiliary powertrain. Molten potassium hydroxide penetrates well-aligned graphene layers vertically and consequently generates both suitable pores that are easily accessible to the electrolyte and a large fraction of electrochemically active edge sites. We expect that our findings will motivate further research related to energy storage devices and also environmentally friendly electric vehicles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Structure, electrical characteristics, and high-temperature stability of aerosol jet printed silver nanoparticle films

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Md Taibur; McCloy, John; Panat, Rahul, E-mail: rahul.panat@wsu.edu, E-mail: rvchintalapalle@utep.edu [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99163 (United States); Ramana, C. V., E-mail: rahul.panat@wsu.edu, E-mail: rvchintalapalle@utep.edu [Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968 (United States)

    2016-08-21

    Printed electronics has emerged as a versatile eco-friendly fabrication technique to create sintered nanoparticle (NP) films on arbitrary surfaces with an excellent control over the film microstructure. While applicability of such films for high-temperature applications is not explored previously, herein we report the high-temperature electrical stability of silver (Ag) metal NP films fabricated using an Aerosol Jet based printing technique and demonstrate that this behavior is dictated by changes in the film microstructure. In-situ high temperature (24–500 °C) impedance spectroscopy measurements show that the real part of the impedance increases with increasing temperature up to 150 °C, at which point a decreasing trend prevails until 300 °C, followed again by an increase in impedance. The electrical behavior is correlated with the in-situ grain growth of the Ag NP films, as observed afterwards by scanning electron microscopy and X-ray diffraction (XRD), and could be tailored by controlling the initial microstructure through sintering conditions. Using combined diffraction and spectroscopic analytical methods, it is demonstrated the Aerosol Jet printed Ag NP films exhibit enhanced thermal stability and oxidation resistance. In addition to establishing the conditions for stability of Ag NP films, the results provide a fundamental understanding of the effect of grain growth and reduction in grain boundary area on the electrical stability of sintered NP films.

  4. Development of high-performance ER gel produced by electric-field assisted molding

    International Nuclear Information System (INIS)

    Kakinuma, Y; Aoyama, T; Anzai, H

    2009-01-01

    Electro-rheological gel (ERG) is a novel functional elastomer whose surface frictional and adhesive property varies according to the intensity of applied electric field. This peculiar phenomenon is named as Electro-adhesive effect. A generated shear stress of ERG under applied electric field is approximately 30∼40 times higher than that of ERF because of high adhesive strength. However, the performances of ERG vary widely due to its surface condition, especially density and distribution of ER particles at the surface. In order to stabilize and improve the performance of ERG, the electric- filed assisted molding process is proposed as the producing method of ERG. In this study, first, the principle of electro-adhesive effect is theoretically investigated. Second, a high-performance ERG produced by the proposed process, in which ER particles are aligned densely at the surface, is developed and its performance is evaluated experimentally. As the experimental result, the high-performance ERG shows twice higher shear stress than the conventional ERG.

  5. Structure, electrical characteristics, and high-temperature stability of aerosol jet printed silver nanoparticle films

    International Nuclear Information System (INIS)

    Rahman, Md Taibur; McCloy, John; Panat, Rahul; Ramana, C. V.

    2016-01-01

    Printed electronics has emerged as a versatile eco-friendly fabrication technique to create sintered nanoparticle (NP) films on arbitrary surfaces with an excellent control over the film microstructure. While applicability of such films for high-temperature applications is not explored previously, herein we report the high-temperature electrical stability of silver (Ag) metal NP films fabricated using an Aerosol Jet based printing technique and demonstrate that this behavior is dictated by changes in the film microstructure. In-situ high temperature (24–500 °C) impedance spectroscopy measurements show that the real part of the impedance increases with increasing temperature up to 150 °C, at which point a decreasing trend prevails until 300 °C, followed again by an increase in impedance. The electrical behavior is correlated with the in-situ grain growth of the Ag NP films, as observed afterwards by scanning electron microscopy and X-ray diffraction (XRD), and could be tailored by controlling the initial microstructure through sintering conditions. Using combined diffraction and spectroscopic analytical methods, it is demonstrated the Aerosol Jet printed Ag NP films exhibit enhanced thermal stability and oxidation resistance. In addition to establishing the conditions for stability of Ag NP films, the results provide a fundamental understanding of the effect of grain growth and reduction in grain boundary area on the electrical stability of sintered NP films.

  6. Structure, electrical characteristics, and high-temperature stability of aerosol jet printed silver nanoparticle films

    Science.gov (United States)

    Rahman, Md Taibur; McCloy, John; Ramana, C. V.; Panat, Rahul

    2016-08-01

    Printed electronics has emerged as a versatile eco-friendly fabrication technique to create sintered nanoparticle (NP) films on arbitrary surfaces with an excellent control over the film microstructure. While applicability of such films for high-temperature applications is not explored previously, herein we report the high-temperature electrical stability of silver (Ag) metal NP films fabricated using an Aerosol Jet based printing technique and demonstrate that this behavior is dictated by changes in the film microstructure. In-situ high temperature (24-500 °C) impedance spectroscopy measurements show that the real part of the impedance increases with increasing temperature up to 150 °C, at which point a decreasing trend prevails until 300 °C, followed again by an increase in impedance. The electrical behavior is correlated with the in-situ grain growth of the Ag NP films, as observed afterwards by scanning electron microscopy and X-ray diffraction (XRD), and could be tailored by controlling the initial microstructure through sintering conditions. Using combined diffraction and spectroscopic analytical methods, it is demonstrated the Aerosol Jet printed Ag NP films exhibit enhanced thermal stability and oxidation resistance. In addition to establishing the conditions for stability of Ag NP films, the results provide a fundamental understanding of the effect of grain growth and reduction in grain boundary area on the electrical stability of sintered NP films.

  7. High-tension electrical-arc-induced thermal burns caused by railway overhead cables.

    Science.gov (United States)

    Koller, J

    1991-10-01

    Eleven patients with high-tension electrical-arc-induced thermal burns due to railway overhead cables were treated at the Bratislava Burn Department during a relatively short period of 18 months. All the injuries occurred by the same mechanism, that is persons climbing on top of railway carriages and approaching the 25,000 V a.c. overhead cables. All the burns were the result of an electrical arc passing externally to the body, with subsequent ignition of the victim's clothes. The cutaneous burns, ranging from 24 to 79 per cent of the BSA, were mostly deep partial to full skin thickness injuries. One patient died on day 5 postburn, the other survived. In spite of high-tension aetiology, no true electrical injuries appear to have occurred and no amputations were necessary. The pathophysiology and possible preventive measures are discussed. It must be stressed that arcing can be induced by an earthed object approaching, but not touching, a cable carrying a high voltage.

  8. Development of high-performance ER gel produced by electric-field assisted molding

    Energy Technology Data Exchange (ETDEWEB)

    Kakinuma, Y; Aoyama, T [Department of System Design Engineering, Keio University, 3-14-1 Hiyoshi Kouhoku-ku Yokohama (Japan); Anzai, H [Fujikura kasei Co., Ltd. 2-6-15 Shibakouen, Minato-ku, Tokyo (Japan)], E-mail: kakinuma@sd.keio.ac.jp

    2009-02-01

    Electro-rheological gel (ERG) is a novel functional elastomer whose surface frictional and adhesive property varies according to the intensity of applied electric field. This peculiar phenomenon is named as Electro-adhesive effect. A generated shear stress of ERG under applied electric field is approximately 30{approx}40 times higher than that of ERF because of high adhesive strength. However, the performances of ERG vary widely due to its surface condition, especially density and distribution of ER particles at the surface. In order to stabilize and improve the performance of ERG, the electric- filed assisted molding process is proposed as the producing method of ERG. In this study, first, the principle of electro-adhesive effect is theoretically investigated. Second, a high-performance ERG produced by the proposed process, in which ER particles are aligned densely at the surface, is developed and its performance is evaluated experimentally. As the experimental result, the high-performance ERG shows twice higher shear stress than the conventional ERG.

  9. High breakdown electric field in β-Ga2O3/graphene vertical barristor heterostructure

    Science.gov (United States)

    Yan, Xiaodong; Esqueda, Ivan S.; Ma, Jiahui; Tice, Jesse; Wang, Han

    2018-01-01

    In this work, we study the high critical breakdown field in β-Ga2O3 perpendicular to its (100) crystal plane using a β-Ga2O3/graphene vertical heterostructure. Measurements indicate a record breakdown field of 5.2 MV/cm perpendicular to the (100) plane that is significantly larger than the previously reported values on lateral β-Ga2O3 field-effect-transistors (FETs). This result is compared with the critical field typically measured within the (100) crystal plane, and the observed anisotropy is explained through a combined theoretical and experimental analysis.

  10. An investigation into preparation of silver sheathed superconducting wires with a high critical temperature

    International Nuclear Information System (INIS)

    Chaffron, Laurent

    1992-01-01

    We have shown that the critical current density of YBaCuO superconducting wires prepared using 'powder in tube' method is limited by the following principal factors: - cracks and porosity arising from the shrinkage of the powder during sintering, - irregularities in the wire section, - presence of secondary phases in the phase diagram of the three oxides, - incomplete re-oxidation at the centre of the wire, - insufficient, or complete lack of, texture in the wire, - presence of amorphous, non superconducting phase across the grains that blocks grain boundary migration. We have reduced the deleterious effects due to the first four factors by modifying prior nature of the powder, by reinforcing the sheath and by modifying the thermal treatments. We also used creep sintering to produce a strong texture; however, our study shows that texture, though necessary, is not a sufficient condition for a high current. This is because the latter is limited by the presence of the amorphous phase at too many grain boundaries. Finally, we have obtained wires in which grain boundaries are clean and which have very high critical currents by melting the wire in a thermal gradient and by passing it through the gradient very slowly. Such a technique, however, is too slow for producing superconductors. (author) [fr

  11. Criticality assessment for prismatic high temperature reactors by fuel stochastic Monte Carlo modeling

    Energy Technology Data Exchange (ETDEWEB)

    Zakova, Jitka [Department of Nuclear and Reactor Physics, Royal Institute of Technology, KTH, Roslagstullsbacken 21, S-10691 Stockholm (Sweden)], E-mail: jitka.zakova@neutron.kth.se; Talamo, Alberto [Nuclear Engineering Division, Argonne National Laboratory, ANL, 9700 South Cass Avenue, Argonne, IL 60439 (United States)], E-mail: alby@anl.gov

    2008-05-15

    Modeling of prismatic high temperature reactors requires a high precision description due to the triple heterogeneity of the core and also to the random distribution of fuel particles inside the fuel pins. On the latter issue, even with the most advanced Monte Carlo techniques, some approximation often arises while assessing the criticality level: first, a regular lattice of TRISO particles inside the fuel pins and, second, the cutting of TRISO particles by the fuel boundaries. We utilized two of the most accurate Monte Codes: MONK and MCNP, which are both used for licensing nuclear power plants in United Kingdom and in the USA, respectively, to evaluate the influence of the two previous approximations on estimating the criticality level of the Gas Turbine Modular Helium Reactor. The two codes exactly shared the same geometry and nuclear data library, ENDF/B, and only modeled different lattices of TRISO particles inside the fuel pins. More precisely, we investigated the difference between a regular lattice that cuts TRISO particles and a random lattice that axially repeats a region containing over 3000 non-cut particles. We have found that both Monte Carlo codes provide similar excesses of reactivity, provided that they share the same approximations.

  12. Assessment of Extremely Low Frequency (ELF Electric and Magnetic Fields in Hamedan High Electrical Power Stations and their Effects on Workers

    Directory of Open Access Journals (Sweden)

    Farshid Ghorbani Shahna

    2011-09-01

    Full Text Available Introduction: Public and occupational exposure to extremely low frequency (ELF electric and magnetic fields induced by electrical equipment is a significant issue in the environment and at the workplace due to their potential health effects on public health. The purpose of this study was assessment of the electric and magnetic fields intensities and determination of mental and psychological effects of occupational exposure in the high voltage electric power stations in the city of Hamadan, Iran. Material and Methods: The intensities of the magnetic and electric fields were measured at eight high voltage electric power stations at three different intervals of sources using an HI-3604 instrument. A two-part questionnaire was used to assess mental and psychological effects of the exposure to these fields. Two groups of control and case workers including 30 samples were selected to determine the exposure effects. Results: The results of field measurements showed the highest average electric field intensity was related to the CVT unit with 3110 V/m at a 2 m distance from the source and the lowest average was related to the control room with 1.35 V/m next to the source. Also, the highest and lowest magnetic field intensities were close to the transformator 2 and the battery room (50.42 and 1.31 mG, respectively. Discussion and Conclusion: The intensities of electric and magnetic fields in the selected stations are lower than the ACGIH and ICNIRP standard levels for occupational exposures. The results obtained indicate that the distribution of these fields was nonlinear around the sources and the effects observed on exposed workers were non-thermal.

  13. High-Lift Propeller Noise Prediction for a Distributed Electric Propulsion Flight Demonstrator

    Science.gov (United States)

    Nark, Douglas M.; Buning, Pieter G.; Jones, William T.; Derlaga, Joseph M.

    2017-01-01

    Over the past several years, the use of electric propulsion technologies within aircraft design has received increased attention. The characteristics of electric propulsion systems open up new areas of the aircraft design space, such as the use of distributed electric propulsion (DEP). In this approach, electric motors are placed in many different locations to achieve increased efficiency through integration of the propulsion system with the airframe. Under a project called Scalable Convergent Electric Propulsion Technology Operations Research (SCEPTOR), NASA is designing a flight demonstrator aircraft that employs many "high-lift propellers" distributed upstream of the wing leading edge and two cruise propellers (one at each wingtip). As the high-lift propellers are operational at low flight speeds (take-off/approach flight conditions), the impact of the DEP configuration on the aircraft noise signature is also an important design consideration. This paper describes efforts toward the development of a mulit-fidelity aerodynamic and acoustic methodology for DEP high-lift propeller aeroacoustic modeling. Specifically, the PAS, OVERFLOW 2, and FUN3D codes are used to predict the aerodynamic performance of a baseline high-lift propeller blade set. Blade surface pressure results from the aerodynamic predictions are then used with PSU-WOPWOP and the F1A module of the NASA second generation Aircraft NOise Prediction Program to predict the isolated high-lift propeller noise source. Comparisons of predictions indicate that general trends related to angle of attack effects at the blade passage frequency are captured well with the various codes. Results for higher harmonics of the blade passage frequency appear consistent for the CFD based methods. Conversely, evidence of the need for a study of the effects of increased azimuthal grid resolution on the PAS based results is indicated and will be pursued in future work. Overall, the results indicate that the computational

  14. Critical evaluation of high-temperature gas-cooled reactors applicable to coal conversion

    International Nuclear Information System (INIS)

    Spiewak, I.; Jones, J.E. Jr.; Rittenhouse, P.L.; DeStefano, J.R.; Delene, J.G.

    1975-12-01

    A critical review is presented of the technology and costs of very high-temperature gas-cooled reactors (VHTRs) applicable to nuclear coal conversion. Coal conversion processes suitable for coupling to reactors are described. Vendor concepts of the VHTR are summarized. The materials requirements as a function of process temperature in the range 1400 to 2000 0 F are analyzed. Components, environmental and safety factors, economics and nuclear fuel cycles are reviewed. It is concluded that process heat supply in the range 1400 to 1500 0 F could be developed with a high degree of assurance. Process heat at 1600 0 F would require considerably more materials development. While temperatures up to 2000 0 F appear to be attainable, considerably more research and risk were involved. A demonstration plant would be required as a step in the commercialization of the VHTR

  15. Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

    International Nuclear Information System (INIS)

    Wang, Hong; Lee, Sung-Min; Wang, James L.; Lin, Hua-Tay

    2014-01-01

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10 8 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications, such as piezoelectric fuel injectors in heavy-duty diesel engines

  16. Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

    Science.gov (United States)

    Wang, Hong; Lee, Sung-Min; Wang, James L.; Lin, Hua-Tay

    2014-12-01

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications, such as piezoelectric fuel injectors in heavy-duty diesel engines.

  17. Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong, E-mail: wangh@ornl.gov; Lee, Sung-Min; Wang, James L. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Lin, Hua-Tay [School of Mechanical and Electronic Engineering, Guangdong University of Technology, Guangzhou, 510006 (China)

    2014-12-21

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10{sup 8} cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications, such as piezoelectric fuel injectors in heavy-duty diesel engines.

  18. A design study of high electric power for fast reactor cooled by supercritical light water

    International Nuclear Information System (INIS)

    Koshizuka, Seiichi

    2000-03-01

    In order to evaluate the possibility to achieve high electric power by a fast reactor with supercritical light water, the design study was carried out on a large fast reactor core with high coolant outlet temperature (SCFR-H). Since the reactor coolant circuit uses once-through direct cycle where all feedwater flows through the core to the turbine at supercritical pressure, it is possible to design much simpler and more compact reactor systems and to achieve higher thermal efficiency than those of current light water reactors. The once-through direct cycle system is employed in current fossil-fired power plants. In the present study, three types of core were designed. The first is SCFR-H with blankets cooled by ascending flow, the second is SCFR-H with blankets cooled by descending flow and the third is SCFR-H with high thermal power. Every core was designed to achieve the thermal efficiency over 43%, positive coolant density reactivity coefficient and electric power over 1600 MW. Core characteristics of SCFR-Hs were compared with those of SCLWR-H (electric power: 1212 MW), which is a thermal neutron spectrum reactor cooled and moderated by supercritical light water, with the same diameter of the reactor pressure vessel. It was shown that SCFR-H could increase the electric power about 1.7 times maximally. From the standpoint of the increase of a reactor thermal power, a fast reactor has advantages as compared with a thermal neutron reactor, because it can increase the power density by adopting tight fuel lattices and eliminating the moderator region. Thus, it was concluded that a reactor cooled by supercritical light water could further improve the cost competitiveness by using a fast neutron spectrum and achieving a higher thermal power. (author)

  19. The effects of high frequency current ripple on electric vehicle battery performance

    International Nuclear Information System (INIS)

    Uddin, Kotub; Moore, Andrew D.; Barai, Anup; Marco, James

    2016-01-01

    Highlights: • Experimental study into the impact of current ripple on li-ion battery degradation. • 15 cells exercised with 1200 cycles coupled AC–DC signals, at 5 frequencies. • Results highlight a greater spread of degradation for cells exposed to AC excitation. • Implications for BMS control, thermal management and system integration. - Abstract: The power electronic subsystems within electric vehicle (EV) powertrains are required to manage both the energy flows within the vehicle and the delivery of torque by the electrical machine. Such systems are known to generate undesired electrical noise on the high voltage bus. High frequency current oscillations, or ripple, if unhindered will enter the vehicle’s battery system. Real-world measurements of the current on the high voltage bus of a series hybrid electric vehicle (HEV) show that significant current perturbations ranging from 10 Hz to in excess of 10 kHz are present. Little is reported within the academic literature about the potential impact on battery system performance and the rate of degradation associated with exposing the battery to coupled direct current (DC) and alternating currents (AC). This paper documents an experimental investigation that studies the long-term impact of current ripple on battery performance degradation. Initial results highlight that both capacity fade and impedance rise progressively increase as the frequency of the superimposed AC current increases. A further conclusion is that the spread of degradation for cells cycled with a coupled AC–DC signal is considerably more than for cells exercised with a traditional DC waveform. The underlying causality for this degradation is not yet understood. However, this has important implications for the battery management system (BMS). Increased variations in cell capacity and impedance will cause differential current flows and heat generation within the battery pack that if not properly managed will further reduce battery life

  20. Intermetallic and electrical insulator coatings on high-temperature alloys in liquid-lithium environments

    International Nuclear Information System (INIS)

    Park, J.H.

    1994-06-01

    In the design of liquid-metal cooling systems for fusion-reactor blanket, applications, the corrosion resistance of structural materials and the magnetohydrodynamic (MHD) force and its subsequent influence on thermal hydraulics and corrosion are major concerns. When the system is cooled by liquid metals, insulator coatings are required on piping surfaces in contact with the coolant. The objective of this study is to develop stable corrosion-resistant electrical insulator coatings at the liquid-metal/structural-material interface, with emphasis on electrically insulating coatings that prevent adverse MHD-generated currents from passing through the structural wall, and Be-V intermetallic coatings for first-wall components that face the plasma. Vanadium and V-base alloys are leading candidate materials for structural applications in a fusion reactor. Various intermetallic films were produced on V-alloys and on Types 304 and 316 stainless steel. The intermetallic layers were developed by exposure of the materials to liquid Li containing 2 at temperatures of 500--1030 degree C. CaO electrical insulator coatings were produced by reaction of the oxygen-rich layer with <5 at. % Ca dissolved in liquid Li at 400--700 degree C. The reaction converted the oxygen-rich layer to an electrically insulating film. This coating method is applicable to reactor components because the liquid metal can be used over and over; only the solute within the liquid metal is consumed. This paper will discuss initial results on the nature of the coatings and their in-situ electrical resistivity characteristics in liquid Li at high temperatures