WorldWideScience

Sample records for energy field samspil

  1. Tur-samspil i musikterapi med børn med svære kommunikationsvanskeligheder

    DEFF Research Database (Denmark)

    Holck, Ulla

    2006-01-01

    Tur-samspil udgør en vigtig grundsten i den tidlige sociale og kommunikative udvikling, og optræder ofte i musikterapeutiske samspil med kommunikationssvage børn. Artiklen præsenterer relevante begreber fra faglitteraturen om tur-samspil i voksendialoger (de såkaldte Konversationsanalyser), som k...

  2. Interaction innovation and competency development in the Danish energy field; Samspil, innovation og kompetenceudvikling paa det danske energiomraade - resultater af en spoergeskemaundersoegelse

    Energy Technology Data Exchange (ETDEWEB)

    Nygaard Tanner, A.; Borup, M.; Dannemand Andersen, P. (Technical Univ. of Denmark, DTU Management, Kgs. Lyngby (Denmark)); Gregersen, B. (Aalborg Univ., Institut for Erhvervsstudier, Aalborg (Denmark))

    2009-09-15

    This report presents the results of a questionnaire survey on interaction, innovation and skills development among Danish companies, universities and other organizations within the energy field. The survey was conducted in 2007 and is part of a larger research project on terms of energy technology development. The report's figures compare results focusing on five technology areas: energy efficient technologies, wind, bio energy, hydrogen technologies and solar cells. Furthermore, there is a series of graphs giving the results across the various types of organizations. The report was carried out as a working tool for those who are interested in detailed insight into the results. For further conclusions and discussion of results refer to the book 'New Energy and Innovation in Denmark'.

  3. Tema: Når 9 regnmålere i et forsyningsområde ikke er nok..

    DEFF Research Database (Denmark)

    Laden, Bo; Sørensen, Morten Steen; Nielsen, Jesper Ellerbæk

    2015-01-01

    Aalborg Forsyning, Kloak A/S overvejer i øjeblikket i samråd med Aalborg Universitet, hvordan samspil mellem forsyningens 9 regnmålere og et kommende regn radarsystem udformes optimalt. Behovet for dette samspil blev tydeliggjort ved en regnhændelse den 11. maj 2014.......Aalborg Forsyning, Kloak A/S overvejer i øjeblikket i samråd med Aalborg Universitet, hvordan samspil mellem forsyningens 9 regnmålere og et kommende regn radarsystem udformes optimalt. Behovet for dette samspil blev tydeliggjort ved en regnhændelse den 11. maj 2014....

  4. Conversion of gravity field energy. Konversion von Schwerkraft-Feld-Energie

    Energy Technology Data Exchange (ETDEWEB)

    Nieper, H A

    1981-01-01

    This book by Mittelstandsinstitut Niedersachsen is a proceedings volume on the conference on energy technology on November 27/28, 1980. The meeting was attended by about 360 persons. On the basis of the knowledge presented, conversion of tachyon field energy into useful electrical energy appears possible. The tachyon field is present everywhere in space. Seike estimated its field strength at 8.8 x 10/sup 8/ V/cm. Magnetic and electrostatic fields can intercept tachyon energy. Especially masses subject to strong magnetic induction take up much tachyon energy. Also abrupt changes of voltage seem to extract energy from tachyons. The Gray motor is based on this principle. Further devices taking energy from the tachyon field are presented, e.g. the Johnson motor which has recently been given the Pat. No. US 4 151 431.

  5. Fra Plan til Undervisning

    DEFF Research Database (Denmark)

    Ingerslev, Gitte Holten; Svejgaard, Karin; Madsen, Anne-Grethe

    Fra plan til undervisningspraksis ? en evaluering af fagligt samspil Resumé: Fra plan til undervisning er en rapport fra et evalueringsprojekt finansieret af undervisningsministeriets midler til udviklingsarbejde og forsøg på de gymnasiale uddannelser. Projektet er gennemført af et konsortium...... fremstilles i rapporten Fra plan til Undervisning som tre cases. Casene indeholder en del fællestræk, da skolernes arbejde med fagligt samspil udspringer af en række fælles erfaringer og træk ved undervisningskulturen på htx. Det gælder først og fremmest det forhold, at fagligt samspil knyttes sammen med de...

  6. Energy from field crops

    Energy Technology Data Exchange (ETDEWEB)

    Zubr, J.

    1990-04-15

    At the Research Station of Royal Veterinary and Agricultural University, Copenhagen, Denmark, investigation concerning cultivation and exploitation of field crops for production of fuels was carried out during the period 1986-1989. High yielding crops, such as sugar beet - BETA VULGARIS, jerusalem artichoke - HELIANTHUS TUBEROSUS, rhubarb - RHEUM RHAPONTICUM, and comfrey - SYMPHYTUM ASPERUM, were grown experimentally in the field. Different cultivation methods for the crops were used and evaluated. Simultaneously with the field experiment, laboratory investigation was carried out to determine the energy potential of different products and by-products from the crops processes, such as alcoholic and methanogenic fermantation. Production expenses for the crops were determined, and cost of the fuels was estimated. The experimental results show that beet is a superior crop for the climatic conditions of Northern Europe. In the season 1986, yields exceeded 20 t TS/ha in the form of roots and tops, where achieved. A combined exploitation of beet roots and tops via alcoholic and methanogenic fermantation gave a gross energy corresponding to 80 hl OE/ha/yr. Using methanogenic fermentation exclusively, from ensiled beet roots and tops, gross energy yield corresponding to 85 hl IE/ha/yr, was achieved. The cost of energy in the form of alcohol from beet roots was estimated to be 5.17 DKK/1 OE (0.64 ECU/l OE). The cost of energy in the form of methane from ensiled beet tops, was estimated to be 2.68 DKK/l OE (0.33 ECU/l OE). At the present time, methane produced on the basis of ensiled beet roots and tops appears to be competitive with fossil fuels. Irrespective of the cost, however, the possibility of producing clean energy from field crops remains of interest for the future. (author) 27 refs.

  7. A multifunctional energy-saving magnetic field generator

    Science.gov (United States)

    Xiong, Hui; Sun, Wanpeng; Liu, Jinzhen; Shi, Jinhua

    2018-03-01

    To improve the energy utilization of magnetic field generators for biological applications, a multifunctional energy-saving magnetic field generator (ESMFG) is presented. It is capable of producing both an alternating magnetic field (AMF) and a bipolar pulse magnetic field (BPMF) with high energy-saving and energy-reuse rates. Based on a theoretical analysis of an RLC second-order circuit, the energy-saving and energy-reuse rates of both types of magnetic fields can be calculated and are found to have acceptable values. The results of an experimental study using the proposed generator show that for the BPMF, the peak current reaches 130 A and the intensity reaches 70.3 mT. For the AMF, the intensity is 11.0 mT and the RMS current is 20 A. The energy-saving and energy-reuse rates for the AMF generator are 61.3% and 63.5%, respectively, while for the BPMF generator, the energy-saving rate is 33.6%. Thus, the proposed ESMFG has excellent potential for use in biomedical applications.

  8. Field Flows of Dark Energy

    Energy Technology Data Exchange (ETDEWEB)

    Cahn, Robert N.; de Putter, Roland; Linder, Eric V.

    2008-07-08

    Scalar field dark energy evolving from a long radiation- or matter-dominated epoch has characteristic dynamics. While slow-roll approximations are invalid, a well defined field expansion captures the key aspects of the dark energy evolution during much of the matter-dominated epoch. Since this behavior is determined, it is not faithfully represented if priors for dynamical quantities are chosen at random. We demonstrate these features for both thawing and freezing fields, and for some modified gravity models, and unify several special cases in the literature.

  9. Near-field enhanced thermionic energy conversion for renewable energy recycling

    Science.gov (United States)

    Ghashami, Mohammad; Cho, Sung Kwon; Park, Keunhan

    2017-09-01

    This article proposes a new energy harvesting concept that greatly enhances thermionic power generation with high efficiency by exploiting the near-field enhancement of thermal radiation. The proposed near-field enhanced thermionic energy conversion (NETEC) system is uniquely configured with a low-bandgap semiconductor cathode separated from a thermal emitter with a subwavelength gap distance, such that a significant amount of electrons can be photoexcited by near-field thermal radiation to contribute to the enhancement of thermionic current density. We theoretically demonstrate that the NETEC system can generate electric power at a significantly lower temperature than the standard thermionic generator, and the energy conversion efficiency can exceed 40%. The obtained results reveal that near-field photoexcitation can enhance the thermionic power output by more than 10 times, making this hybrid system attractive for renewable energy recycling.

  10. "Jeg bliver sådan helt nervøs, hvis det var en mand, der skulle lave det"

    DEFF Research Database (Denmark)

    Grosen, Sidsel Lond; Holt, Helle; Hvid, Helge Søndergaard

    2010-01-01

    dokumentafdelingen er der tydeligvis et samspil mellem forestillinger om køn og arbejde. For at forstå og give mening til dette samspil trækker kvinderne på historisk indlejrede kønsstereotypier, som fx at kvinder primært er omsorgsydere, at kvinder er gode til at multitaske, og at kvinder kan lide rutinearbejde....

  11. Conflict field energy

    International Nuclear Information System (INIS)

    Krebsbach-Gnath, C.

    1981-01-01

    Violent social controversies characterize the treatment of the energy problem. Solutions of this conflict decisively depend on the knowledge and evaluation of the causes and the possible development. How is it possible to explain the opinions, views, and the attitude of the population to different kinds of energy. Which factors are decisive for the explosive effect and the stability of the conflict in the field of nulcear energy. What will happen when there arises a possible lack of energy. Which socio-political effects will such a lack have. Are there new proposals for solving problems in the nulcear-energy debate. The contributions of this book are results of scientific and empiric works. They provide perceptive approaches and analyses to the problems and by discussing them are useful in giving an orientation for political action. (orig.) [de

  12. Energy buildup in sheared force-free magnetic fields

    Science.gov (United States)

    Wolfson, Richard; Low, Boon C.

    1992-01-01

    Photospheric displacement of the footpoints of solar magnetic field lines results in shearing and twisting of the field, and consequently in the buildup of electric currents and magnetic free energy in the corona. The sudden release of this free energy may be the origin of eruptive events like coronal mass ejections, prominence eruptions, and flares. An important question is whether such an energy release may be accompanied by the opening of magnetic field lines that were previously closed, for such open field lines can provide a route for matter frozen into the field to escape the sun altogether. This paper presents the results of numerical calculations showing that opening of the magnetic field is permitted energetically, in that it is possible to build up more free energy in a sheared, closed, force-free magnetic field than is in a related magnetic configuration having both closed and open field lines. Whether or not the closed force-free field attains enough energy to become partially open depends on the form of the shear profile; the results presented compare the energy buildup for different shear profiles. Implications for solar activity are discussed briefly.

  13. En videnskabelig duo: Matematikkens samspil med fysik 1809-1950

    DEFF Research Database (Denmark)

    Lützen, Jesper

    2005-01-01

    The paper argues that the development of mathematics and physics must be considered together. Examples are given of the many types of interaction between the two fields, and a periodization of the different types of interactions are suggested.......The paper argues that the development of mathematics and physics must be considered together. Examples are given of the many types of interaction between the two fields, and a periodization of the different types of interactions are suggested....

  14. Energy field of thermodynamic syste'ms

    International Nuclear Information System (INIS)

    Volchenkova, R.A.

    1984-01-01

    To reveal the qualitative and quantitative rules, regulating the properties of macro- and microsystems consideration is being given to the dependence of system enthalpy on environmental conditions. It was concluded that the dependence of material system enthalpy on temperature represents the energy field, containing the energy boundaries of phase states, described by exponential functions, in which the elements are arranged monotonically in the sequence of change of interatomic bonds, correlated with their physicomechanical properties; energy boundaries of phase states at that emanate from a single point, which is a reference a single point, which a reference one for the whole material system and determining its energy state in initial position. The presented energy field of thermodynamic systems enables to consider the change of their physicomechanical properties and energy state in dynamic process, depending on environmental parameters. Energy characteristics of single-component systems (W, Re, Hf, Nb, Mo etc) are given

  15. On energy-momentum tensors of gravitational field

    International Nuclear Information System (INIS)

    Nikishov, A.I.

    2001-01-01

    The phenomenological approach to gravitation is discussed in which the 3-graviton interaction is reduced to the interaction of each graviton with the energy-momentum tensor of two others. If this is so, (and in general relativity this is not so), then the problem of choosing the correct energy-momentum tensor comes to finding the right 3-graviton vertex. Several energy-momentum tensors od gravitational field are considered and compared in the lowest approximation. Each of them together with the energy-momentum tensor of point-like particles satisfies the conservation laws when equations of motion of particles are the same as in general relativity. It is shown that in Newtonian approximation the considered tensors differ one from other in the way their energy density is distributed between energy density of interaction (nonzero only at locations of particles) and energy density of gravitational field. Stating from Lorentz invariance, the Lagrangians for spin-2, mass-0 field are considered [ru

  16. High energy bremsstrahlung in an intense laser field

    International Nuclear Information System (INIS)

    Schlessinger, L.; Wright, J.A.

    1980-02-01

    The cross section for bremsstrahlung emission and absorption by electrons in an intense laser field has been calculated in the Born approximation for the electron-ion potential. Typical numerical results are presented as a function of the ratio of the electron guiver energy to its energy and the ratio of the bremsstrahlung energy to the electron energy. The intense field correction factor for the rate of bremsstrahlung emission and absorption for electrons with a Boltzmann distribution of energies has been calculated. Numerical results for the correction factor are presented for the Boltzmann case as a function of the ratio of the electron quiver energy to its thermal energy and the ratio of the bremsstrahlung energy to the thermal energy. For typical laser fusion parameters, this correction factor which is the ratio of the thermal bremsstrahlung emission rate in the intense laser field to the rate at zero field can be quite significant. For a laser of wavelength 1.06 μm at an intensity of 3 x 10 15 w/cm 2 and an electron temperature of 1 keV, the correction factor varies from 0.98 at a bremsstrahlung energy of 100 V to greater than 5 at a bremsstrahlung energy of 10 keV

  17. Individual Dosimetry for High Energy Radiation Fields

    International Nuclear Information System (INIS)

    Spurny, F.

    1999-01-01

    The exposure of individuals on board aircraft increased interest in individual dosimetry in high energy radiation fields. These fields, both in the case of cosmic rays as primary radiation and at high energy particle accelerators are complex, with a large diversity of particle types, their energies, and linear energy transfer (LET). Several already existing individual dosemeters have been tested in such fields. For the component with high LET (mostly neutrons) etched track detectors were tested with and without fissile radiators, nuclear emulsions, bubble detectors for both types available and an albedo dosemeter. Individual dosimetry for the low LET component has been performed with thermoluminescent detectors (TLDs), photographic film dosemeters and two types of electronic individual dosemeters. It was found that individual dosimetry for the low LET component was satisfactory with the dosemeters tested. As far as the high LET component is concerned, there are problems with both the sensitivity and the energy response. (author)

  18. A study on environmental pollution control in energy field

    Energy Technology Data Exchange (ETDEWEB)

    Min, B.M.; Son, J.E.; Lee, H.K.; Choi, W.K.; Baek, I.H.; Lee, J.S. [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

    1995-12-01

    This report is contained such as following contents; Preparation of the stepwise pollution control strategies to reduce pollutants in energy field, which will be satisfy to tightened emission standard in the future. Analysis of the environmental pollution control technologies level, which related to energy field in domestic and other countries. Visualization of the reduction strategies of domestic carbon dioxide emission in energy field. And, discussion and proposal of the R and D program to improve the domestic environmental pollution control technologies in energy field. (author). 99 refs., 67 figs., 73 tabs.

  19. Energy-momentum tensor of the electromagnetic field

    International Nuclear Information System (INIS)

    Horndeski, G.W.; Wainwright, J.

    1977-01-01

    In this paper we investigate the energy-momentum tensor of the most general second-order vector-tensor theory of gravitation and electromagnetism which has field equations which are (i) derivable from a variational principle, (ii) consistent with the notion of conservation of charge, and (iii) compatible with Maxwell's equations in a flat space. This energy-momentum tensor turns out to be quadratic in the first partial derivatives of the electromagnetic field tensor and depends upon the curvature tensor. The asymptotic behavior of this energy-momentum tensor is examined for solutions to Maxwell's equations in Minkowski space, and it is demonstrated that this energy-momentum tensor predicts regions of negative energy density in the vicinity of point sources

  20. Estimation of photon energy distribution in gamma calibration field

    International Nuclear Information System (INIS)

    Takahashi, Fumiaki; Shimizu, Shigeru; Yamaguchi, Yasuhiro

    1997-03-01

    Photon survey instruments used for radiation protection are usually calibrated at gamma radiation fields, which are traceable to the national standard with regard to exposure. Whereas scattered radiations as well as primary gamma-rays exit in the calibration field, no consideration for the effect of the scattered radiations on energy distribution is given in routine calibration works. The scattered radiations can change photon energy spectra in the field, and this can result in misinterpretations of energy-dependent instrument responses. Construction materials in the field affect the energy distribution and magnitude of the scattered radiations. The geometric relationship between a gamma source and an instrument can determine the energy distribution at the calibration point. Therefore, it is essential for the assurance of quality calibration to estimate the energy spectra at the gamma calibration fields. Then, photon energy distributions at some fields in the Facility of Radiation Standard of the Japan Atomic Energy Research Institute (JAERI) were estimated by measurements using a NaI(Tl) detector and Monte Carlo calculations. It was found that the use of collimator gives a different feature in photon energy distribution. The origin of scattered radiations and the ratio of the scattered radiations to the primary gamma-rays were obtained. The results can help to improve the calibration of photon survey instruments in the JAERI. (author)

  1. Energy weighted x-ray dark-field imaging.

    Science.gov (United States)

    Pelzer, Georg; Zang, Andrea; Anton, Gisela; Bayer, Florian; Horn, Florian; Kraus, Manuel; Rieger, Jens; Ritter, Andre; Wandner, Johannes; Weber, Thomas; Fauler, Alex; Fiederle, Michael; Wong, Winnie S; Campbell, Michael; Meiser, Jan; Meyer, Pascal; Mohr, Jürgen; Michel, Thilo

    2014-10-06

    The dark-field image obtained in grating-based x-ray phase-contrast imaging can provide information about the objects' microstructures on a scale smaller than the pixel size even with low geometric magnification. In this publication we demonstrate that the dark-field image quality can be enhanced with an energy-resolving pixel detector. Energy-resolved x-ray dark-field images were acquired with a 16-energy-channel photon-counting pixel detector with a 1 mm thick CdTe sensor in a Talbot-Lau x-ray interferometer. A method for contrast-noise-ratio (CNR) enhancement is proposed and validated experimentally. In measurements, a CNR improvement by a factor of 1.14 was obtained. This is equivalent to a possible radiation dose reduction of 23%.

  2. Guides' Intercultural Strategies in an Interaction Perspective

    DEFF Research Database (Denmark)

    Meged, Jane Widtfeldt

    2010-01-01

    Guidede ture foregår ofte i et interkulturelt spændingsfelt mellem guider, turister og destinationen.  I samspil med turisterne undvikler og anvender guiderne en række interkulturelle kommunikations strategier til at skabe sammenhæng, spænding og identitet i fortællingerne. Artiklen undersøger...... hvordan en række autoriserede guider fra København i samspil med hhv. engelsk, tysk, italiensk og spansktalende turister performer interkulturelle strategier....

  3. Finite field-energy of a point charge in QED

    International Nuclear Information System (INIS)

    Costa, Caio V; Gitman, Dmitry M; Shabad, Anatoly E

    2015-01-01

    We consider a simple nonlinear (quartic in the fields) gauge-invariant modification of classical electrodynamics, to show that it possesses a regularizing ability sufficient to make the field energy of a point charge finite. The model is exactly solved in the class of static central-symmetric electric fields. Collation with quantum electrodynamics (QED) results in the total field energy of a point elementary charge about twice the electron mass. The proof of the finiteness of the field energy is extended to include any polynomial selfinteraction, thereby the one that stems from the truncated expansion of the Euler–Heisenberg local Lagrangian in QED in powers of the field strength. (paper)

  4. Ultra high energy cosmic rays and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor; Engel, Ralph; Alvarez-Muniz, Jaime; Seckel, David

    2002-07-01

    We follow the propagation of ultra high energy protons in the presence of random and regular magnetic fields and discuss some of the changes in the angular and energy distributions of these particles introduced by the scattering in the magnetic fields.

  5. Ultra high energy cosmic rays and magnetic fields

    International Nuclear Information System (INIS)

    Stanev, Todor; Engel, Ralph; Alvarez-Muniz, Jaime; Seckel, David

    2002-01-01

    We follow the propagation of ultra high energy protons in the presence of random and regular magnetic fields and discuss some of the changes in the angular and energy distributions of these particles introduced by the scattering in the magnetic fields

  6. Energy released by the interaction of coronal magnetic fields

    International Nuclear Information System (INIS)

    Sheeley, N.R. Jr.

    1976-01-01

    Comparisons between coronal spectroheliograms and photospheric magnetograms are presented to support the idea that as coronal magnetic fields interact, a process of field line reconnection usually takes place as a natural way of preventing magnetic stresses from building up in the lower corona. This suggests that the energy which would have been stored in stressed fields in continuously released as kinetic energy of material being driven aside to make way for the reconnecting fields. However, this kinetic energy is negligible compared to the thermal energy of the coronal plasma. Therefore, it appears that these slow adjustments of coronal magnetic fields cannot account for even the normal heating of the corona, much less the energetic events associated with solar flares. (Auth.)

  7. Optimisation of magnetic field and R.F. in a azimuthally varying field variable energy cyclotrons

    International Nuclear Information System (INIS)

    Ismail, M.; Divatia, A.S.

    1975-01-01

    A computer program is developed for determining magnetic field and reference frequency. Setting necessary to produce a specific ion beam with a given energy in variable energy cyclotrons. The program carries out field trimming calculations using an iterated least square process. For each of the prescribed set of energy values, the E.O. code computes the relevant properties of the equilibrium orbit and the linear oscillation about this orbit to assess the merits and defects of a given medium field. The program consists of parts for: (1) Fourier analysis of the magnetic field (2) calculation of cyclotron trim-coil currents for field optimization (3) generating data for equilibrium orbit (4) determination of the phase energy characteristic of the ion beam and (5) iteration process. (M.G.B.)

  8. Experimental microdosimetry in high energy radiation fields

    International Nuclear Information System (INIS)

    Spurny, F.; Bednar, J.; Vlcek, B.; Bottollier-Depois, J.-F.; Molokanov, A.G.

    2000-01-01

    To determine microdosimetric characteristics in the beams and fields of high energy panicles with the goal, also, to compare the classical method of experimental microdosimetry, a tissue equivalent low pressure proportional counter (TEPC) with the linear energy transfer (LET) spectrometer based on a chemically etched polyallyldiglycolcarbonate as a track etched detector (TED). To test the use of TED LET spectrometer in the conditions, where the use or TEPC is not possible (high energy charged particle beams at high dose rates). The results obtained with the TEPC NAUSICAA were used in this work to compare them with other data. This TEPC measures directly the linear energy in the interval between 0.15 and 1500 keV/μm in tissue, the low gas pressure (propan based TE mixture) permits to simulate a tissue element of about 3 μm. It can be used in the fields with instantaneous dose equivalent rates between 1 μSv/hour and 1 mSv/ hour. TED LET spectrometer developed to determine LET spectra between 10 and 700 keV/μm in tissue. Primarily, track-to-bulk etch rate ratios are determined through the track parameters measurements, the spectra of these ratios are convened to LET spectra using the calibration curve established by means of heavy charge panicles. The critical volume of thi spectrometer is supposed to be a few nm. There is no limit of use for the dose rate, the background tracks limit the lowest threshold to about 1 mSv, the overlapping of tracks (the highest one) to 100 mSv. Both experimental microdosimetry methods have been used in on board aircraft radiation fields, in on-Earth high energy radiation reference fields, and in the beams of protons with energies up to 300 MeV (Dubna, Moscow, Loma Linda). First, it should be emphasized, that in all high energy radiation fields studied, we concentrated our analysis on the region, where both methods overlap, i.e. between 10 and 1000 keV/μm in tissue. It should be also stressed, that the events observed in this region

  9. Gravitational collapse of dark energy field configurations and supermassive black hole formation

    International Nuclear Information System (INIS)

    Jhalani, V.; Kharkwal, H.; Singh, A.

    2016-01-01

    Dark energy is the dominant component of the total energy density of our Universe. The primary interaction of dark energy with the rest of the Universe is gravitational. It is therefore important to understand the gravitational dynamics of dark energy. Since dark energy is a low-energy phenomenon from the perspective of particle physics and field theory, a fundamental approach based on fields in curved space should be sufficient to understand the current dynamics of dark energy. Here, we take a field theory approach to dark energy. We discuss the evolution equations for a generic dark energy field in curved space-time and then discuss the gravitational collapse for dark energy field configurations. We describe the 3 + 1 BSSN formalism to study the gravitational collapse of fields for any general potential for the fields and apply this formalism to models of dark energy motivated by particle physics considerations. We solve the resulting equations for the time evolution of field configurations and the dynamics of space-time. Our results show that gravitational collapse of dark energy field configurations occurs and must be considered in any complete picture of our Universe. We also demonstrate the black hole formation as a result of the gravitational collapse of the dark energy field configurations. The black holes produced by the collapse of dark energy fields are in the supermassive black hole category with the masses of these black holes being comparable to the masses of black holes at the centers of galaxies.

  10. Gravitational collapse of dark energy field configurations and supermassive black hole formation

    Energy Technology Data Exchange (ETDEWEB)

    Jhalani, V.; Kharkwal, H.; Singh, A., E-mail: anupamsingh.iitk@gmail.com [L. N. Mittal Institute of Information Technology, Physics Department (India)

    2016-11-15

    Dark energy is the dominant component of the total energy density of our Universe. The primary interaction of dark energy with the rest of the Universe is gravitational. It is therefore important to understand the gravitational dynamics of dark energy. Since dark energy is a low-energy phenomenon from the perspective of particle physics and field theory, a fundamental approach based on fields in curved space should be sufficient to understand the current dynamics of dark energy. Here, we take a field theory approach to dark energy. We discuss the evolution equations for a generic dark energy field in curved space-time and then discuss the gravitational collapse for dark energy field configurations. We describe the 3 + 1 BSSN formalism to study the gravitational collapse of fields for any general potential for the fields and apply this formalism to models of dark energy motivated by particle physics considerations. We solve the resulting equations for the time evolution of field configurations and the dynamics of space-time. Our results show that gravitational collapse of dark energy field configurations occurs and must be considered in any complete picture of our Universe. We also demonstrate the black hole formation as a result of the gravitational collapse of the dark energy field configurations. The black holes produced by the collapse of dark energy fields are in the supermassive black hole category with the masses of these black holes being comparable to the masses of black holes at the centers of galaxies.

  11. Energy of the field for the field

    International Nuclear Information System (INIS)

    2001-01-01

    Considering the problems that are presented in the field related with the lack of available energy is presented, the Biogas like energy alternative. This is a resulting product of the fermentation anaerobic (without air) of the organic residuals under appropriate conditions of humidity. It is a mixture of gases in which they prevail: Methane (CH 4 ) in a 55 to 70 percent, Dioxide of Carbon (CO 2 ) in a 28 to 43 percent and others as the hydro sulphide by 2 percent. The composition of the biogas depends of: the quality of the used material, of the biodigestor type, of the ambient temperature, of the adopted time of retention. Some of the advantages of the use of this alternative are: better sanitary conditions in the rural means. Decrease in the consumption of inorganic fertilizers. Increase of the agricultural productivity with the employment of the Bio fertilizing (20/25 bigger percent) in comparison with the fresh manure; conservation of natural resources as fuels, fossils and firewood; energy production in the own local consumption. Perfect ecological solution for the obtaining of renewable energy and bio fertilizing

  12. 4 hovedproblemer med STU

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    2012-01-01

    Kommentaren oplister fire hovedproblemer ved den Særligt Tilrettelagte Ungdomsuddannelse, nemlig (1) beskrivelsen af målgruppen, (2) de unges forsørgelsesgrundlag, (3) hvad der følger efter én afsluttet STU, og (4) "lovjunglen" - manglende samspil mellem mange lovgivninger.......Kommentaren oplister fire hovedproblemer ved den Særligt Tilrettelagte Ungdomsuddannelse, nemlig (1) beskrivelsen af målgruppen, (2) de unges forsørgelsesgrundlag, (3) hvad der følger efter én afsluttet STU, og (4) "lovjunglen" - manglende samspil mellem mange lovgivninger....

  13. Energy-extraction processes from a Kerr black hole immersed in a magnetic field. I. Negative-energy states

    International Nuclear Information System (INIS)

    Dhurandhar, S.V.; Dadhich, N.

    1984-01-01

    This is the first of two papers on the energy-extraction processes near a Kerr black hole immersed in a magnetic field. In this paper we shall consider the consequences of a dipole field extending to infinity matched on to a uniform field in the interior which contains the Kerr black hole. The magnetic fields considered are perturbative in nature. The matching of the fields is imperative owing to the ''no-hair theorem'' and the second law of black-hole physics. Two intriguing situations arising in this context are discussed, namely, (1) the second law of black-hole physics and (2) the law of conservation of energy in an energy-extraction process. At first sight both these laws seem to be violated. These issues arise basically because in the presence of the magnetic field there can exist negative-energy states even for L>0 particles. These issues get resolved by realizing that it is the sign of P/sub c/phi = L-eA/sub cphi/ and not L which determines a corotating or counterrotating orbit. It is also shown that negative-energy states can exist away from the horizon in the presence of either of the fields, the dipole and the uniform, thus favoring energy-extraction processes away from the black hole. This type of energy extraction is solely a consequence of the magnetic field. Also, a fairly detailed analysis of the effective-potential curves is provided, mainly relevant to the existence of negative energies and energy extraction. The formalism of the energy-extraction process will be considered in the second paper

  14. The free energies of partially open coronal magnetic fields

    Science.gov (United States)

    Low, B. C.; Smith, D. F.

    1993-01-01

    A simple model of the low corona is examined in terms of a static polytropic atmosphere in equilibrium with a global magnetic field. The question posed is whether magnetostatic states with partially open magnetic fields may contain magnetic energies in excess of those in fully open magnetic fields. Based on the analysis presented here, it is concluded that the cross-field electric currents in the pre-eruption corona are a viable source of the bulk of the energies in a mass ejection and its associated flare.

  15. High-energy behavior of field-strength interactions

    International Nuclear Information System (INIS)

    Levin, D.N.

    1976-01-01

    It is known that spontaneously broken gauge theories are the only renormalizable theories of massive spin-one particles with mass dimension less than or equal to 4. This paper describes a search for renormalizable interactions with higher mass dimension. Specifically, we examine the high-energy behavior of a class of models which involve field-strength interactions. Power counting shows that the high-energy behavior of these models is no worse than the naively estimated high-energy behavior of a gauge theory in the U gauge. Therefore, there may be a ''soft'' symmetry-breaking mechanism (for instance, a soft divergence of an antisymmetric tensor current) which enforces renormalizable high-energy behavior in the same way that spontaneously broken gauge invariance guarantees the renormalizability of gauge theories. This hope is supported by the existence of ''gauge theories'' of strings, which describe analogous interactions of strings and field strengths. Unfortunately, this idea is tarnished by explicit calculations in which renormalizability is imposed in the form of unitarity bounds. These unitarity bounds imply that all possible field-strength couplings must be zero and that the remaining interactions describe a spontaneously broken gauge theory. Thus this result supports an earlier conjecture that gauge theories are the only renormalizable theories of massive vector bosons

  16. Energy Conversion Mechanism for Electron Perpendicular Energy in High Guide-Field Reconnection

    Science.gov (United States)

    Guo, Xuehan; Horiuchi, Ritoku; Kaminou, Yasuhiro; Cheng, Frank; Ono, Yasushi

    2016-10-01

    The energy conversion mechanism for electron perpendicular energy, both the thermal and the kinetic energy, is investigated by means of two-dimensional, full-particle simulations in an open system. It is shown that electron perpendicular heating is mainly due to the breaking of magnetic moment conservation in separatrix region because the charge separation generates intense variation of electric field within the electron Larmor radius. Meanwhile, electron perpendicular acceleration takes place manly due to the polarization drift term as well as the curvature drift term of E . u⊥ in the downstream near the X-point. The enhanced electric field due to the charge separation there results in a significant effect of the polarization drift term on the dissipation of magnetic energy within the ion inertia length in the downstream. Japan Society for the Promotion of Science (JSPS) Fellows 15J03758.

  17. Algebraic structure of general electromagnetic fields and energy flow

    International Nuclear Information System (INIS)

    Hacyan, Shahen

    2011-01-01

    Highlights: → Algebraic structure of general electromagnetic fields in stationary spacetime. → Eigenvalues and eigenvectors of the electomagnetic field tensor. → Energy-momentum in terms of eigenvectors and Killing vector. → Explicit form of reference frame with vanishing Poynting vector. → Application of formalism to Bessel beams. - Abstract: The algebraic structures of a general electromagnetic field and its energy-momentum tensor in a stationary space-time are analyzed. The explicit form of the reference frame in which the energy of the field appears at rest is obtained in terms of the eigenvectors of the electromagnetic tensor and the existing Killing vector. The case of a stationary electromagnetic field is also studied and a comparison is made with the standard short-wave approximation. The results can be applied to the general case of a structured light beams, in flat or curved spaces. Bessel beams are worked out as example.

  18. Progress with High-Field Superconducting Magnets for High-Energy Colliders

    Science.gov (United States)

    Apollinari, Giorgio; Prestemon, Soren; Zlobin, Alexander V.

    2015-10-01

    One of the possible next steps for high-energy physics research relies on a high-energy hadron or muon collider. The energy of a circular collider is limited by the strength of bending dipoles, and its maximum luminosity is determined by the strength of final focus quadrupoles. For this reason, the high-energy physics and accelerator communities have shown much interest in higher-field and higher-gradient superconducting accelerator magnets. The maximum field of NbTi magnets used in all present high-energy machines, including the LHC, is limited to ˜10 T at 1.9 K. Fields above 10 T became possible with the use of Nb3Sn superconductors. Nb3Sn accelerator magnets can provide operating fields up to ˜15 T and can significantly increase the coil temperature margin. Accelerator magnets with operating fields above 15 T require high-temperature superconductors. This review discusses the status and main results of Nb3Sn accelerator magnet research and development and work toward 20-T magnets.

  19. Energy potential, energy ratios, and the amount of net energy in Finnish field crop production; Peltobioenergian tuotanto Suomessa. Potentiaali, energiasuhteet ja nettoenergia

    Energy Technology Data Exchange (ETDEWEB)

    Mikkola, H.

    2012-11-01

    Energy potential, energy ratios, and the amount of net energy in Finnish field crop production were studied in this thesis. Special attention was paid to indirect energy inputs and how to treat them in energy analysis. Manufacturing of machines and agrochemicals and production of seeds are examples of indirect energy inputs.The bioenergy potential of the Finnish field crop production could be as large as 12 - 22 TWh, or 3 - 5% of the total energy consumption in Finland in 2008. The major part of this energy would originate from straw and biomass like reed canary grass cultivated for energy use. However, only 0.5 TWh of the potential is utilized. The output/input energy ratios of the studied field crops varied from 3 to 18, being highest (18) for reed canary grass and second highest (7) for sugar beet and grass cultivated for silage. The energy ratio of cereals and oil seed crops varied from 3 to 5 if only the yield of seeds was considered. If the yield of straw and stems was also taken into account the energy ratios would have been almost twofold. The energy ratios for Finnish wheat and barley were as high as those gained in Italian and Spanish conditions, respectively. However, the energy ratios of maize, elephant grass and giant reed were even over 50 in Central and Southern Europe. Plants that use the C4 photosynthesis pathway and produce high biomass yields thrive best in warm and sunny climate conditions. They use nitrogen and water more sparingly than C3 plants typically thriving in the cooler part of the temperate zone. When evaluating energy ratios for field crops it should be kept in mind that the maximal energy potential of the energy crop is the heating value of the dry matter at the field gate. Transportation of the crop and production of liquid fuels and electricity from biomass lowers the energy ratio. A comparison of field energy crops to a reforested field suggested that fast growing trees, as hybrid aspen and silver birch, would yield almost as

  20. Meaningful Field Trip in Education of Renewable Energy Technologies

    Directory of Open Access Journals (Sweden)

    Hasan Said Tortop

    2013-06-01

    Full Text Available Renewable energy sources, in terms of countries‟ obtaining their energy needs from clean and without harming the environment is becoming increasingly important. This situation also requires improving the quality of science education will be given in this field. In this activity, in a field trip to the center for the renewable energy resources technologies, the application of learning cycle model appropriate for constructivist approach is shown. In the example of solar chimney activity according to 5E model, in elaboration step, students, by using their imagination and creativity, put out recommendations and new designs for the efficiency of the application of solar chimney. It is quite important for educators to follow what kind of acquisitions that students will gain and what kind of changes will occur in their perceptions and attitudes towards renewable energy technologies thanks to this activity. Related documents are in attachments. This activity has been very helpful in the education of young scientists on the field of renewable energy sources technologies.

  1. Energy minibands degeneration induced by magnetic field effects in graphene superlattices

    Science.gov (United States)

    Reyes-Villagrana, R. A.; Carrera-Escobedo, V. H.; Suárez-López, J. R.; Madrigal-Melchor, J.; Rodríguez-Vargas, I.

    2017-12-01

    Energy minibands are a basic feature of practically any superlattice. In this regard graphene superlattices are not the exception and recently miniband transport has been reported through magneto-transport measurements. In this work, we compute the energy miniband and transport characteristics for graphene superlattices in which the energy barriers are generated by magnetic and electric fields. The transfer matrix approach and the Landauer-Büttiker formalism have been implemented to calculate the energy minibands and the linear-regime conductance. We find that energy minibands are very sensitive to the magnetic field and become degenerate by rising it. We were also able to correlate the evolution of the energy minibands as a function of the magnetic field with the transport characteristics, finding that miniband transport can be destroyed by magnetic field effects. Here, it is important to remark that although magnetic field effects have been a key element to unveil miniband transport, they can also destroy it.

  2. EFFECTS OF FIELD-LINE TOPOLOGY ON ENERGY PROPAGATION IN THE CORONA

    Energy Technology Data Exchange (ETDEWEB)

    Candelaresi, S.; Pontin, D. I.; Hornig, G. [Division of Mathematics, University of Dundee, Dundee, DD1 4HN (United Kingdom)

    2016-12-01

    We study the effect of photospheric footpoint motions on magnetic field structures containing magnetic nulls. The footpoint motions are prescribed on the photospheric boundary as a velocity field that entangles the magnetic field. We investigate the propagation of the injected energy, the conversion of energy, emergence of current layers, and other consequences of the nontrivial magnetic field topology in this situation. These boundary motions lead initially to an increase in magnetic and kinetic energy. Following this, the energy input from the photosphere is partially dissipated and partially transported out of the domain through the Poynting flux. The presence of separatrix layers and magnetic null points fundamentally alters the propagation behavior of disturbances from the photosphere into the corona. Depending on the field-line topology close to the photosphere, the energy is either trapped or free to propagate into the corona.

  3. Modified weak energy condition for the energy momentum tensor in quantum field theory

    International Nuclear Information System (INIS)

    Latorre, J.

    1998-01-01

    The weak energy condition is known to fail in general when applied to expectation values of the energy momentum tensor in flat space quantum field theory. It is shown how the usual counter arguments against its validity are no longer applicable if the states vertical stroke ψ right angle for which the expectation value is considered are restricted to a suitably defined subspace. A possible natural restriction on vertical stroke ψ right angle is suggested and illustrated by two quantum mechanical examples based on a simple perturbed harmonic oscillator Hamiltonian. The proposed alternative quantum weak energy condition is applied to states formed by the action of the scalar, vector and the energy momentum tensor operators on the vacuum. We assume conformal invariance in order to determine almost uniquely three-point functions involving the energy momentum tensor in terms of a few parameters. The positivity conditions lead to non-trivial inequalities for these parameters. They are satisfied in free field theories, except in one case for dimensions close to two. Further restrictions on vertical stroke ψ right angle are suggested which remove this problem. The inequalities which follow from considering the state formed by applying the energy momentum tensor to the vacuum are shown to imply that the coefficient of the topological term in the expectation value of the trace of the energy momentum tensor in an arbitrary curved space background is positive, in accord with calculations in free field theories. (orig.)

  4. Energy of magnetic moment of superconducting current in magnetic field

    International Nuclear Information System (INIS)

    Gurtovoi, V.L.; Nikulov, A.V.

    2015-01-01

    Highlights: • Quantization effects observed in superconducting loops are considered. • The energy of magnetic moment in magnetic field can not be deduced from Hamiltonian. • This energy is deduced from a history of the current state in the classical case. • It can not be deduced directly in the quantum case. • Taking this energy into account demolishes agreement between theory and experiment. - Abstract: The energy of magnetic moment of the persistent current circulating in superconducting loop in an externally produced magnetic field is not taken into account in the theory of quantization effects because of identification of the Hamiltonian with the energy. This identification misleads if, in accordance with the conservation law, the energy of a state is the energy expended for its creation. The energy of magnetic moment is deduced from a creation history of the current state in magnetic field both in the classical and quantum case. But taking this energy into account demolishes the agreement between theory and experiment. Impartial consideration of this problem discovers the contradiction both in theory and experiment

  5. Calculating Casimir energies in renormalizable quantum field theory

    International Nuclear Information System (INIS)

    Milton, Kimball A.

    2003-01-01

    Quantum vacuum energy has been known to have observable consequences since 1948 when Casimir calculated the force of attraction between parallel uncharged plates, a phenomenon confirmed experimentally with ever increasing precision. Casimir himself suggested that a similar attractive self-stress existed for a conducting spherical shell, but Boyer obtained a repulsive stress. Other geometries and higher dimensions have been considered over the years. Local effects, and divergences associated with surfaces and edges were studied by several authors. Quite recently, Graham et al. have reexamined such calculations, using conventional techniques of perturbative quantum field theory to remove divergences, and have suggested that previous self-stress results may be suspect. Here we show that the examples considered in their work are misleading; in particular, it is well known that in two space dimensions a circular boundary has a divergence in the Casimir energy for massless fields, while for general spatial dimension D not equal to an even integer the corresponding Casimir energy arising from massless fields interior and exterior to a hyperspherical shell is finite. It has also long been recognized that the Casimir energy for massive fields is divergent for curved boundaries. These conclusions are reinforced by a calculation of the relevant leading Feynman diagram in D and in three dimensions. There is therefore no doubt of the validity of the conventional finite Casimir calculations

  6. Cooperative Enhancement Mechanisms of Low Energy Nuclear Reactions Using Superlow Energy External Fields

    OpenAIRE

    Gareev, F. A.; Zhidkova, I. E.

    2006-01-01

    We proposed a new mechanism of LENR: cooperative processes in whole system - nuclei+atoms+condensed matter can occur at smaller threshold energies then corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution inner energy of whole system.

  7. Energy Savings from Optimised In-Field Route Planning for Agricultural Machinery

    Directory of Open Access Journals (Sweden)

    Efthymios Rodias

    2017-10-01

    Full Text Available Various types of sensors technologies, such as machine vision and global positioning system (GPS have been implemented in navigation of agricultural vehicles. Automated navigation systems have proved the potential for the execution of optimised route plans for field area coverage. This paper presents an assessment of the reduction of the energy requirements derived from the implementation of optimised field area coverage planning. The assessment regards the analysis of the energy requirements and the comparison between the non-optimised and optimised plans for field area coverage in the whole sequence of operations required in two different cropping systems: Miscanthus and Switchgrass production. An algorithmic approach for the simulation of the executed field operations by following both non-optimised and optimised field-work patterns was developed. As a result, the corresponding time requirements were estimated as the basis of the subsequent energy cost analysis. Based on the results, the optimised routes reduce the fuel energy consumption up to 8%, the embodied energy consumption up to 7%, and the total energy consumption from 3% up to 8%.

  8. New theory of radiative energy transfer in free electromagnetic fields

    International Nuclear Information System (INIS)

    Wolf, E.

    1976-01-01

    A new theory of radiative energy transfer in free, statistically stationary electromagnetic fields is presented. It provides a model for energy transport that is rigorous both within the framework of the stochastic theory of the classical field as well as within the framework of the theory of the quantized field. Unlike the usual phenomenological model of radiative energy transfer that centers around a single scalar quantity (the specific intensity of radiation), our theory brings into evidence the need for characterizing the energy transport by means of two (related) quantities: a scalar and a vector that may be identified, in a well-defined sense, with ''angular components'' of the average electromagnetic energy density and of the average Poynting vector, respectively. Both of them are defined in terms of invariants of certain new electromagnetic correlation tensors. In the special case when the field is statistically homogeneous, our model reduces to the usual one and our angular component of the average electromagnetic energy density, when multiplied by the vacuum speed of light, then acquires all the properties of the specific intensity of radiation. When the field is not statistically homogeneous our model approximates to the usual phenomenological one, provided that the angular correlations between plane wave modes of the field extend over a sufficiently small solid angle of directions about the direction of propagation of each mode. It is tentatively suggested that, when suitably normalized, our angular component of the average electromagnetic energy density may be interpreted as a quasi-probability (general quantum-mechancial phase-space distribution function, such as Wigner's) for the position and the momentum of a photon

  9. Lower Bound on the Energy Density in Classical and Quantum Field Theories.

    Science.gov (United States)

    Wall, Aron C

    2017-04-14

    A novel method for deriving energy conditions in stable field theories is described. In a local classical theory with one spatial dimension, a local energy condition always exists. For a relativistic field theory, one obtains the dominant energy condition. In a quantum field theory, there instead exists a quantum energy condition, i.e., a lower bound on the energy density that depends on information-theoretic quantities. Some extensions to higher dimensions are briefly discussed.

  10. Energy loss of ions by electric-field fluctuations in a magnetized plasma.

    Science.gov (United States)

    Nersisyan, Hrachya B; Deutsch, Claude

    2011-06-01

    The results of a theoretical investigation of the energy loss of charged particles in a magnetized classical plasma due to the electric-field fluctuations are reported. The energy loss for a test particle is calculated through the linear-response theory. At vanishing magnetic field, the electric-field fluctuations lead to an energy gain of the charged particle for all velocities. It has been shown that in the presence of strong magnetic field, this effect occurs only at low velocities. In the case of high velocities, the test particle systematically loses its energy due to the interaction with a stochastic electric field. The net effect of the fluctuations is the systematic reduction of the total energy loss (i.e., the sum of the polarization and stochastic energy losses) at vanishing magnetic field and reduction or enhancement at strong field, depending on the velocity of the particle. It is found that the energy loss of the slow heavy ion contains an anomalous term that depends logarithmically on the projectile mass. The physical origin of this anomalous term is the coupling between the cyclotron motion of the plasma electrons and the long-wavelength, low-frequency fluctuations produced by the projectile ion. This effect may strongly enhance the stochastic energy gain of the particle.

  11. Characterization of Monoenergetic Low Energy Neutron Fields with the {mu}TPC Detector

    Energy Technology Data Exchange (ETDEWEB)

    Golabek, C.; Lebreton, L.; Petit, M. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Billard, J.; Grignon, C.; Bosson, G.; Bourrion, O.; Guillaudin, O.; Mayet, F.; Richer, J.-P.; Santos, D. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph (France)

    2011-12-13

    The AMANDE facility produces monoenergetic neutron fields from 2 keV to 20 MeV for metrological purposes. To be considered as a reference facility, fluence and energy distributions of neutron fields have to be determined by primary measurement standards. For this purpose, a micro Time Projection Chamber is being developed to be dedicated to measure neutron fields with energy ranging from 2 keV up to 1 MeV. We present simulations showing that such a detector, which allows the measurement of the ionization energy and the 3D reconstruction of the recoil nucleus, provides the determination of neutron energy and fluence of such low energy neutron fields.

  12. Energy-momentum tensor of intermediate vector bosons in an external electromagnetic field

    International Nuclear Information System (INIS)

    Mostepanenko, V.M.; Sokolov, I.Yu.

    1988-01-01

    Expressions are obtained for the canonical and metric energy-momentum tensors of the vector field of intermediate bosons in an external electromagnetic field. It is shown that in the case of a gyromagnetic ratio not equal to unity the energy-momentum tensor cannot be symmetrized on its indices, and an additional term proportional to the anomalous magnetic moment appears in the conservation laws. A modification of the canonical formalism for scalar and vector fields in an external field is proposed in accordance with which the Hamiltonian density is equal to the 00 component of the energy-momentum tensor. An expression for the energy-momentum tensor of a closed system containing a gauge field of intermediate bosons and an electromagnetic field is obtained

  13. Biomass for energy from field crops

    Energy Technology Data Exchange (ETDEWEB)

    Zubr, J.

    1988-01-01

    On the basis of a field experiment, selected crops were evaluated for feasibility in producing biomass applicable as raw material for fuels. Both the main products and byproducts of the crops were investigated in the laboratory for qualitative characteristics and were subjected to methanogenic fermentation under mesophilic conditions. The biogas energy potential and gross energy potential were determined. Under the climatic conditions of Northern Europe, sugar beet (Beta vulgaris) was found to be a superior energy crop. White cabbage (Brassica oleracea var. Capitata), rhubarb (Rheum rhaponticum) and comfrey (Symphytum asperum) can be considered as potential crops for biomass. The agrotechnical and the economic aspects of the biomass production are being subjected to further investigation.

  14. New Cooperative Mechanisms of Low Energy Nuclear Reactions Using Superlow Energy External Fields

    OpenAIRE

    Gareev, F. A.; Zhidkova, I. E.

    2005-01-01

    We proposed a new mechanism of LENR: cooperative processes in whole system - nuclei+atoms+condensed matter can occur at smaller threshold then corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution inner energy of whole system.

  15. Low dose out-of-field radiotherapy, part 2: Calculating the mean photon energy values for the out-of-field photon energy spectrum from scattered radiation using Monte Carlo methods.

    Science.gov (United States)

    Skrobala, A; Adamczyk, S; Kruszyna-Mochalska, M; Skórska, M; Konefał, A; Suchorska, W; Zaleska, K; Kowalik, A; Jackowiak, W; Malicki, J

    2017-08-01

    During radiotherapy, leakage from the machine head and collimator expose patients to out-of-field irradiation doses, which may cause secondary cancers. To quantify the risks of secondary cancers due to out-of-field doses, it is first necessary to measure these doses. Since most dosimeters are energy-dependent, it is essential to first determine the type of photon energy spectrum in the out-of-field area. The aim of this study was to determine the mean photon energy values for the out-of-field photon energy spectrum for a 6 MV photon beam using the GEANT 4-Monte Carlo method. A specially-designed large water phantom was simulated with a static field at gantry 0°. The source-to-surface distance was 92cm for an open field size of 10×10cm2. The photon energy spectra were calculated at five unique positions (at depths of 0.5, 1.6, 4, 6, 8, and 10cm) along the central beam axis and at six different off-axis distances. Monte Carlo simulations showed that mean radiation energy levels drop rapidly beyond the edge of the 6 MV photon beam field: at a distance of 10cm, the mean energy level is close to 0.3MeV versus 1.5MeV at the central beam axis. In some cases, the energy level actually increased even as the distance from the field edge increased: at a depth of 1.6cm and 15cm off-axis, the mean energy level was 0.205MeV versus 0.252MeV at 20cm off-axis. The out-of-field energy spectra and dose distribution data obtained in this study with Monte Carlo methods can be used to calibrate dosimeters to measure out-of-field radiation from 6MV photons. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  16. Quantum vacuum energy near a black hole: the Maxwell field

    International Nuclear Information System (INIS)

    Elster, T.

    1984-01-01

    A quantised Maxwell field is considered propagating in the gravitational field of a Schwarzschild black hole. The vector Hartle-Hawking propagator is defined on the Riemannian section of the analytically continued space-time and expanded in terms of four-dimensional vector spherical harmonics. The equations for the radial functions appearing in the expansion are derived for both odd and even parity. Using the expansion of the vector Hartle-Hawking propagator, the point-separated expectation value of the Maxwellian energy-momentum tensor in the Hartle-Hawking vacuum is derived. The renormalised values of radial pressure, tangential pressure and energy density are obtained near the horizon of the black hole. In contrast to the scalar field, the Maxwell field exhibits a positive energy density near the horizon in the Hartle-Hawking vacuum state. (author)

  17. Magnetic field dependence of vortex activation energy

    Indian Academy of Sciences (India)

    ... the resistance as a function of temperature and magnetic field in clean polycrystalline samples of NbSe2, MgB2 and Bi2Sr2Ca2Cu3O10 (BSCCO) superconductors. Thermally activated flux flow behaviour is seen in all the three systems and clearly identified in bulk MgB2. While the activation energy at low fields for MgB2 ...

  18. Latin American research and development in the energy field

    International Nuclear Information System (INIS)

    Torres, J.E.

    1984-08-01

    This report is divided into six main sections. The first outlines the conceptual framework and methodology stressing the limitations that impede greater depth of analysis. The second, on the types and directions of research and development (R and D) activities in Latin America, is divided into three subsections, covering New and Renewable Sources of Energy (NRSE); conventional energy (including nuclear energy); and integrated energy resource R and D (primarily energy conservation and substitution, as well as energy policy and planning studies). In each subsection, I endeavoured to describe and critically assess R and D activities, achievements, and failures within the context of the limitations. Conclusions and recommendations in each case are implicitly or explicitly made depending on the field. In the third section, the state of science and technology policy on energy resources is presented. The fourth section draws together the conclusions and recommendations on further work to be done. The fifth section is a bibliography of 64 annotated and 52 unannotated items and the sixth, an appendix, is a directory of people working in the field of energy research

  19. Euro-mediterranean partnership in the energy field

    International Nuclear Information System (INIS)

    Perrin, F.

    1996-01-01

    The conference for a Euro-Mediterranean partnership in the energy field took place from the seventh to ninth of June 1996 and convened the officials of 15 european countries and 10 mediterranean countries; the discussions were about five themes: the adhesion of mediterranean countries to the european chart of energy or their association to this treaty; the harmonization of legislations and regulations concerning investments; the development of gas and electric networks in this area; the positioning of a system to guarantee energy investments; the creation of an Euro-Mediterranean energy forum proposed by the commission which allowed to associate the different partners to the following of this cooperation. (N.C.)

  20. Energy flux due to electromagnetic fluctuations during guide field magnetic reconnection

    International Nuclear Information System (INIS)

    Kuwahata, Akihiro; Inomoto, Michiaki; Ono, Yasushi; Yanai, Ryoma

    2016-01-01

    Large electromagnetic fluctuations inside the current sheet and large reconnection electric fields are observed during fast magnetic reconnection in the presence of a guide field. The fluctuations transport 2.5% of the dissipated magnetic energy from the reconnection region. Although the energy gains of the ions and electrons are approximately 60% and 12%, respectively, of the dissipated magnetic energy after the fast reconnection, the energy of fluctuations is not comparable to their energy gains. The fluctuations do not directly contribute to the energy conversion but might cause the fast reconnection leading to the rapid release of magnetic energy. (author)

  1. Measurability of quantum fields and the energy-time uncertainty relation

    International Nuclear Information System (INIS)

    Mensky, Mikhail B

    2011-01-01

    Quantum restrictions on the measurability of an electromagnetic field strength and their relevance to the energy-time uncertainty relation are considered. The minimum errors in measuring electromagnetic field strengths, as they were estimated by the author (1988) in the framework of the phenomenological method of restricted path integral (RPI), are compared with the analogous estimates found by Landau and Peierls (1931) and by Bohr and Rosenfeld (1933) with the help of certain measurement setups. RPI-based restrictions, including those of Landau and Peierls as a special case, hold for any measuring schemes meeting the strict definition of measurement. Their fundamental nature is confirmed by the fact that their associated field detectability condition has the form of the energy-time uncertainty relation. The weaker restrictions suggested by Bohr and Rosenfeld rely on an extended definition of measurement. The energy-time uncertainty relation, which is the condition for the electromagnetic field to be detectable, is applied to the analysis of how the near-field scanning microscope works. (methodological notes)

  2. A Note on Equivalence Among Various Scalar Field Models of Dark Energies

    Science.gov (United States)

    Mandal, Jyotirmay Das; Debnath, Ujjal

    2017-08-01

    In this work, we have tried to find out similarities between various available models of scalar field dark energies (e.g., quintessence, k-essence, tachyon, phantom, quintom, dilatonic dark energy, etc). We have defined an equivalence relation from elementary set theory between scalar field models of dark energies and used fundamental ideas from linear algebra to set up our model. Consequently, we have obtained mutually disjoint subsets of scalar field dark energies with similar properties and discussed our observation.

  3. A {mu}TPC detector for the characterization of low energy neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Golabek, C., E-mail: cedric.golabek@irsn.fr [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Billard, J. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Allaoua, A. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Bosson, G.; Bourrion, O.; Grignon, C.; Guillaudin, O. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Lebreton, L., E-mail: lena.lebreton@irsn.fr [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Mayet, F. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Petit, M. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Richer, J.-P.; Santos, D. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France)

    2012-06-21

    The AMANDE facility produces monoenergetic neutron fields from 2 keV to 20 MeV for metrological purposes. To be considered as a reference facility, fluence and energy distributions of neutron fields have to be determined by primary measurement standards. For this purpose, a micro Time Projection Chamber is being developed to be dedicated to measure neutron fields with energy ranging from 8 keV up to 1 MeV. In this work we present simulations showing that such a detector, which allows the measurement of the ionization energy and the 3D reconstruction of the recoil nucleus, provides the determination of neutron energy and fluence of these neutron fields.

  4. Field Synergy Principle for Energy Conservation Analysis and Application

    Directory of Open Access Journals (Sweden)

    Qun Chen

    2010-01-01

    Full Text Available Optimization of mass and energy transfer process is critical to improve energy efficiency. In this contribution we introduce the field synergy principle as a unified principle for analyzing and improving the performance of the transfer process. Three field synergy numbers are introduced for heat, mass, and momentum transfer, respectively, and three cases are demonstrated for validation. The results indicate that the field synergy numbers will increase when reducing the angle between the velocity vector and the temperature gradient or the species concentration gradient fields in the convective heat or mass transfer, and the overall heat or mass transfer capability is therefore enhanced. In fluid flows, it will reduce the fluid flow drag to decrease the synergy number between the velocity and the velocity gradient fields over the entire domain and to decrease the product between the fluid viscosity and the velocity gradient at the boundary simultaneously.

  5. Modified electron acoustic field and energy applied to observation data

    Energy Technology Data Exchange (ETDEWEB)

    Abdelwahed, H. G., E-mail: hgomaa-eg@yahoo.com, E-mail: hgomaa-eg@mans.edu.eg [College of Science and Humanitarian Studies, Physics Department, Prince Sattam Bin Abdul Aziz University, Alkharj 11942 (Saudi Arabia); Theoretical Physics Research Group, Physics Department, Faculty of Science, Mansoura University, Mansoura 35516 (Egypt); El-Shewy, E. K. [Theoretical Physics Research Group, Physics Department, Faculty of Science, Mansoura University, Mansoura 35516 (Egypt)

    2016-08-15

    Improved electrostatic acoustic field and energy have been debated in vortex trapped hot electrons and fluid of cold electrons with pressure term plasmas. The perturbed higher-order modified-Korteweg-de Vries equation (PhomKdV) has been worked out. The effect of trapping and electron temperatures on the electro-field and energy properties in auroral plasmas has been inspected.

  6. New cooperative mechanisms of low-energy nuclear reactions using super low-energy external field

    International Nuclear Information System (INIS)

    Gareev, F.A.; Zhidkova, I.E.

    2006-01-01

    We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system. (author)

  7. New Cooperative Mechanisms of Low-Energy Nuclear Reactions Using Super Low-Energy External Field

    Science.gov (United States)

    Gareev, F. A.; Zhidkova, I. E.

    We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system.

  8. Numerical analysis of magnetic field in superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    Kanamaru, Y.; Amemiya, Y.

    1991-01-01

    This paper reports that the superconducting magnetic energy storage (SMES) is more useful than the other systems of electric energy storage because of larger stored energy and higher efficiency. The other systems are the battery, the flywheel, the pumped-storage power station. Some models of solenoid type SMES are designed in U.S.A. and Japan. But a high magnetic field happens by the large scale SMES in the living environment, and makes the erroneous operations of the computer display, the pacemaker of the heart and the electronic equipments. We study some fit designs of magnetic shielding of the solenoidal type SMES for reduction of the magnetic field in living environment. When some superconducting shielding coils are over the main storage coil, magnetic field reduces remarkably than the case of non shielding coil. The calculated results of the magnetic field are obtained y the finite element method

  9. Energy-momentum tensor in quantum field theory

    International Nuclear Information System (INIS)

    Fujikawa, K.

    1981-01-01

    The definition of the energy-momentum tensor as a source current coupled to the background gravitational field receives an important modification in quantum theory. In the path-integral approach, the manifest covariance of the integral measure under general coordinate transformations dictates that field variables with weight 1/2 should be used as independent integration variables. An improved energy-momentum tensor is then generated by the variational derivative, and it gives rise to well-defined gravitational conformal (Weyl) anomalies. In the flat--space-time limit, all the Ward-Takahashi identities associated with space-time transformations including the global dilatation become free from anomalies in terms of this energy-momentum tensor, reflecting the general covariance of the integral measure; the trace of this tensor is thus finite at zero momentum transfer for renormalizable theories. The Jacobian for the local conformal transformation, however, becomes nontrivial, and it gives rise to an anomaly for the conformal identity. All the familiar anomalies are thus reduced to either chiral or conformal anomalies. The consistency of the dilatation and conformal identities at vanishing momentum transfer determines the trace anomaly of this energy-momentum tensor in terms of the renormalization-group b function and other parameters. In contrast, the trace of the conventional energy-momentum tensor generally diverges even at vanishing momentum transfer depending on the regularization scheme, and it is subtractively renormalized. We also explain how the apparently different renormalization properties of the chiral and trace anomalies arise

  10. Energy-momentum tensor in quantum field theory

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo.

    1980-12-01

    The definition of the energy-momentum tensor as a source current coupled to the background gravitational field receives an important modification in quantum theory. In the path integral approach, the manifest covariance of the integral measure under general coordinate transformations dictates that field variables with weight 1/2 should be used as independent integration variables. An improved energy-momentum tensor is then generated by the variational derivative, and it gives rise to well-defined gravitational conformal (Weyl) anomalies. In the flat space-time limit, all the Ward-Takahashi identities associate with space-time transformations including the global dilatation become free from anomalies, reflecting the general covariance of the integral measure; the trace of this energy-momentum tensor is thus finite at the zero momentum transfer. The Jacobian for the local conformal transformation however becomes non-trivial, and it gives rise to an anomaly for the conformal identity. All the familiar anomalies are thus reduced to either chiral or conformal anomalies. The consistency of the dilatation and conformal identities at the vanishing momentum transfer determines the trace anomaly of this energy-momentum tensor in terms of the renormalization group β-function and other parameters. In contrast, the trace of the conventional energy-momentum tensor generally diverges even at the vanishing momentum transfer depending on the regularization scheme, and it is subtractively renormalized. We also explain how the apparently different renormalization properties of the chiral and trace anomalies arise. (author)

  11. The High Field Path to Practical Fusion Energy

    Science.gov (United States)

    Mumgaard, Robert; Whyte, D.; Greenwald, M.; Hartwig, Z.; Brunner, D.; Sorbom, B.; Marmar, E.; Minervini, J.; Bonoli, P.; Irby, J.; Labombard, B.; Terry, J.; Vieira, R.; Wukitch, S.

    2017-10-01

    We propose a faster, lower cost development path for fusion energy enabled by high temperature superconductors, devices at high magnetic field, innovative technologies and modern approaches to technology development. Timeliness, scale, and economic-viability are the drivers for fusion energy to combat climate change and aid economic development. The opportunities provided by high-temperature superconductors, innovative engineering and physics, and new organizational structures identified over the last few years open new possibilities for realizing practical fusion energy that could meet mid-century de-carbonization needs. We discuss re-factoring the fusion energy development path with an emphasis on concrete risk retirement strategies utilizing a modular approach based on the high-field tokamak that leverages the broader tokamak physics understanding of confinement, stability, and operational limits. Elements of this plan include development of high-temperature superconductor magnets, simplified immersion blankets, advanced long-leg divertors, a compact divertor test tokamak, efficient current drive, modular construction, and demountable magnet joints. An R&D plan culminating in the construction of an integrated pilot plant and test facility modeled on the ARC concept is presented.

  12. Scaling the energy conversion rate from magnetic field reconnection to different bodies

    International Nuclear Information System (INIS)

    Mozer, F. S.; Hull, A.

    2010-01-01

    Magnetic field reconnection is often invoked to explain electromagnetic energy conversion in planetary magnetospheres, stellar coronae, and other astrophysical objects. Because of the huge dynamic range of magnetic fields in these bodies, it is important to understand energy conversion as a function of magnetic field strength and related parameters. It is conjectured theoretically and shown experimentally that the energy conversion rate per unit area in reconnection scales as the cube of an appropriately weighted magnetic field strength divided by the square root of an appropriately weighted density. With this functional dependence, the energy release in flares on the Sun, the large and rapid variation of the magnetic flux in the tail of Mercury, and the apparent absence of reconnection on Jupiter and Saturn, may be understood. Electric fields at the perihelion of the Solar Probe Plus mission may be tens of V/m.

  13. Field calibration of a TLD albedo dosemeter in the high-energy neutron field of CERF

    International Nuclear Information System (INIS)

    Haninger, T.; Kleinau, P.; Haninger, S.

    2017-01-01

    The new albedo dosemeter-type AWST-TL-GD 04 has been calibrated in the CERF neutron field (CERN-EU high-energy Reference Field). This type of albedo dosemeter is based on thermoluminescent detectors (TLDs) and used by the individual monitoring service of the Helmholtz Zentrum Muenchen (AWST) since 2015 for monitoring persons, who are exposed occupationally against photon and neutron radiation. The motivation for this experiment was to gain a field specific neutron correction factor N n for workplaces at high-energy particle accelerators. N n is a dimensionless factor relative to a basic detector calibration with 137 Cs and is used to calculate the personal neutron dose in terms of H p (10) from the neutron albedo signal. The results show that the sensitivity of the albedo dosemeter for this specific neutron field is not significantly lower as for fast neutrons of a radionuclide source like 252 Cf. The neutron correction factor varies between 0.73 and 1.16 with a midrange value of 0.94. The albedo dosemeter is therefore appropriate to monitor persons, which are exposed at high-energy particle accelerators. (authors)

  14. Holographic dark energy in Brans-Dicke cosmology with chameleon scalar field

    Energy Technology Data Exchange (ETDEWEB)

    Setare, M.R., E-mail: rezakord@ipm.i [Department of Science of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Jamil, Mubasher, E-mail: mjamil@camp.edu.p [Center for Advanced Mathematics and Physics, National University of Sciences and Technology, Rawalpindi 46000 (Pakistan)

    2010-06-07

    We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named L. Our analysis shows that one can obtain the phantom crossing scenario if the model parameter {alpha} (of order unity) is tuned accordingly. Moreover, this behavior is achieved by treating the Brans-Dicke scalar field as a Chameleon scalar field and taking a non-minimal coupling of the scalar field with matter. Hence one can generate phantom-like equation of state from a holographic dark energy model in non-flat universe in the Brans-Dicke cosmology framework.

  15. Holographic dark energy in Brans-Dicke cosmology with chameleon scalar field

    International Nuclear Information System (INIS)

    Setare, M.R.; Jamil, Mubasher

    2010-01-01

    We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named L. Our analysis shows that one can obtain the phantom crossing scenario if the model parameter α (of order unity) is tuned accordingly. Moreover, this behavior is achieved by treating the Brans-Dicke scalar field as a Chameleon scalar field and taking a non-minimal coupling of the scalar field with matter. Hence one can generate phantom-like equation of state from a holographic dark energy model in non-flat universe in the Brans-Dicke cosmology framework.

  16. Energy of Force-Free Magnetic Fields in Relation to Coronal Mass Ejections

    International Nuclear Information System (INIS)

    Choe, G.S.; Cheng, C.Z.

    2002-01-01

    In typical observations of coronal mass ejections (CMEs), a magnetic structure of a helmet-shaped closed configuration bulges out and eventually opens up. However, a spontaneous transition between these field configurations has been regarded to be energetically impossible in force-free fields according to the Aly-Sturrock theorem. The theorem states that the maximum energy state of force-free fields with a given boundary normal field distribution is the open field. The theorem implicitly assumes the existence of the maximum energy state, which may not be taken for granted. In this study, we have constructed force-free fields containing tangential discontinuities in multiple flux systems. These force-free fields can be generated from a potential field by footpoint motions that do not conserve the boundary normal field distribution. Some of these force-free fields are found to have more magnetic energy than the corresponding open fields. The constructed force-free configurations are compared with observational features of CME-bearing active regions. Possible mechanisms of CMEs are also discussed

  17. Effect of magnetic field on the impurity binding energy of the excited ...

    Indian Academy of Sciences (India)

    The effect of external magnetic field on the excited state energies in a spherical quantum dot was studied. The impurity energy and binding energy were calculated using the variational method within the effective mass approximation and finite barrier potential. The results showed that by increasing the magnetic field, the ...

  18. Energy flow in non-equilibrium conformal field theory

    Science.gov (United States)

    Bernard, Denis; Doyon, Benjamin

    2012-09-01

    We study the energy current and its fluctuations in quantum gapless 1d systems far from equilibrium modeled by conformal field theory, where two separated halves are prepared at distinct temperatures and glued together at a point contact. We prove that these systems converge towards steady states, and give a general description of such non-equilibrium steady states in terms of quantum field theory data. We compute the large deviation function, also called the full counting statistics, of energy transfer through the contact. These are universal and satisfy fluctuation relations. We provide a simple representation of these quantum fluctuations in terms of classical Poisson processes whose intensities are proportional to Boltzmann weights.

  19. Low-energy photons in high-energy photon fields--Monte Carlo generated spectra and a new descriptive parameter.

    Science.gov (United States)

    Chofor, Ndimofor; Harder, Dietrich; Willborn, Kay; Rühmann, Antje; Poppe, Björn

    2011-09-01

    The varying low-energy contribution to the photon spectra at points within and around radiotherapy photon fields is associated with variations in the responses of non-water equivalent dosimeters and in the water-to-material dose conversion factors for tissues such as the red bone marrow. In addition, the presence of low-energy photons in the photon spectrum enhances the RBE in general and in particular for the induction of second malignancies. The present study discusses the general rules valid for the low-energy spectral component of radiotherapeutic photon beams at points within and in the periphery of the treatment field, taking as an example the Siemens Primus linear accelerator at 6 MV and 15 MV. The photon spectra at these points and their typical variations due to the target system, attenuation, single and multiple Compton scattering, are described by the Monte Carlo method, using the code BEAMnrc/EGSnrc. A survey of the role of low energy photons in the spectra within and around radiotherapy fields is presented. In addition to the spectra, some data compression has proven useful to support the overview of the behaviour of the low-energy component. A characteristic indicator of the presence of low-energy photons is the dose fraction attributable to photons with energies not exceeding 200 keV, termed P(D)(200 keV). Its values are calculated for different depths and lateral positions within a water phantom. For a pencil beam of 6 or 15 MV primary photons in water, the radial distribution of P(D)(200 keV) is bellshaped, with a wide-ranging exponential tail of half value 6 to 7 cm. The P(D)(200 keV) value obtained on the central axis of a photon field shows an approximately proportional increase with field size. Out-of-field P(D)(200 keV) values are up to an order of magnitude higher than on the central axis for the same irradiation depth. The 2D pattern of P(D)(200 keV) for a radiotherapy field visualizes the regions, e.g. at the field margin, where changes of

  20. On the cosmological propagation of high energy particles in magnetic fields

    International Nuclear Information System (INIS)

    Alves Batista, Rafael

    2015-04-01

    In the present work the connection between high energy particles and cosmic magnetic fields is explored. Particularly, the focus lies on the propagation of ultra-high energy cosmic rays (UHECRs) and very-high energy gamma rays (VHEGRs) over cosmological distances, under the influence of cosmic magnetic fields. The first part of this work concerns the propagation of UHECRs in the magnetized cosmic web, which was studied both analytically and numerically. A parametrization for the suppression of the UHECR flux at energies ∝ 10 18 eV due to diffusion in extragalactic magnetic fields was found, making it possible to set an upper limit on the energy at which this magnetic horizon effect sets in, which is energy loss and interaction processes as well as effects of galactic and extragalactic magnetic fields. The newest version, CRPropa 3, is discussed in details, including the novel feature of cosmological effects in three-dimensional simulations, which enables time dependent studies considering simultaneously magnetic field effects and the cosmological evolution of the universe. An interesting possibility is to use UHECRs to constrain properties of cosmic magnetic fields, and vice-versa. Numerical simulations of the propagation of UHECRs in the magnetized cosmic web, obtained through magnetohydrodynamical simulations of structure formation, were performed. It was studied the effects of different magnetic field seeds on the distribution of cosmic magnetic fields today, and their impact on the propagation of cosmic rays. Furthermore, the influence of uncertainties of the strength of

  1. Energy flow in a bound electromagnetic field: resolution of apparent paradoxes

    International Nuclear Information System (INIS)

    Kholmetskii, A L; Yarman, T

    2008-01-01

    In this paper, we present a resolution of apparent paradoxes formulated in (Kholmetskii A L 2006 Apparent paradoxes in classical electrodynamics: the energy-momentum conservation law for a bound electromagnetic field Eur. J. Phys. 27 825-38; Kholmetskii A L and Yarman T 2008 Apparent paradoxes in classical electrodynamics: a fluid medium in an electromagnetic field Eur. J. Phys. 29 1127) and dealing with the energy flux in a bound electromagnetic field

  2. Averaged null energy condition and difference inequalities in quantum field theory

    International Nuclear Information System (INIS)

    Yurtsever, U.

    1995-01-01

    For a large class of quantum states, all local (pointwise) energy conditions widely used in relativity are violated by the renormalized stress-energy tensor of a quantum field. In contrast, certain nonlocal positivity constraints on the quantum stress-energy tensor might hold quite generally, and this possibility has received considerable attention in recent years. In particular, it is now known that the averaged null energy condition, the condition that the null-null component of the stress-energy tensor integrated along a complete null geodesic is non-negative for all states, holds quite generally in a wide class of spacetimes for a minimally coupled scalar field. Apart from the specific class of spacetimes considered (mainly two-dimensional spacetimes and four-dimensional Minkowski space), the most significant restriction on this result is that the null geodesic over which the average is taken must be achronal. Recently, Ford and Roman have explored this restriction in two-dimensional flat spacetime, and discovered that in a flat cylindrical space, although the stress energy tensor itself fails to satisfy the averaged null energy condition (ANEC) along the (nonachronal) null geodesics, when the ''Casimir-vacuum'' contribution is subtracted from the stress-energy the resulting tensor does satisfy the ANEC inequality. Ford and Roman name this class of constraints on the quantum stress-energy tensor ''difference inequalities.'' Here I give a proof of the difference inequality for a minimally coupled massless scalar field in an arbitrary (globally hyperbolic) two-dimensional spacetime, using the same techniques as those we relied on to prove the ANEC in an earlier paper with Wald. I begin with an overview of averaged energy conditions in quantum field theory

  3. Experimental Measurement of Wave Field Variations around Wave Energy Converter Arrays

    Directory of Open Access Journals (Sweden)

    Louise O’Boyle

    2017-01-01

    Full Text Available Wave energy converters (WECs inherently extract energy from incident waves. For wave energy to become a significant power provider in the future, large farms of WECs will be required. This scale of energy extraction will increase the potential for changes in the local wave field and coastal environment. Assessment of these effects is necessary to inform decisions on the layout of wave farms for optimum power output and minimum environmental impact, as well as on potential site selection. An experimental campaign to map, at high resolution, the wave field variation around arrays of 5 oscillating water column WECs and a methodology for extracting scattered and radiated waves is presented. The results highlight the importance of accounting for the full extent of the WEC behavior when assessing impacts on the wave field. The effect of radiated waves on the wave field is not immediately apparent when considering changes to the entire wave spectrum, nor when observing changes in wave climate due to scattered and radiated waves superimposed together. The results show that radiated waves may account for up to 50% of the effects on wave climate in the near field in particular operating conditions.

  4. Machine learning of accurate energy-conserving molecular force fields

    Science.gov (United States)

    Chmiela, Stefan; Tkatchenko, Alexandre; Sauceda, Huziel E.; Poltavsky, Igor; Schütt, Kristof T.; Müller, Klaus-Robert

    2017-01-01

    Using conservation of energy—a fundamental property of closed classical and quantum mechanical systems—we develop an efficient gradient-domain machine learning (GDML) approach to construct accurate molecular force fields using a restricted number of samples from ab initio molecular dynamics (AIMD) trajectories. The GDML implementation is able to reproduce global potential energy surfaces of intermediate-sized molecules with an accuracy of 0.3 kcal mol−1 for energies and 1 kcal mol−1 Å̊−1 for atomic forces using only 1000 conformational geometries for training. We demonstrate this accuracy for AIMD trajectories of molecules, including benzene, toluene, naphthalene, ethanol, uracil, and aspirin. The challenge of constructing conservative force fields is accomplished in our work by learning in a Hilbert space of vector-valued functions that obey the law of energy conservation. The GDML approach enables quantitative molecular dynamics simulations for molecules at a fraction of cost of explicit AIMD calculations, thereby allowing the construction of efficient force fields with the accuracy and transferability of high-level ab initio methods. PMID:28508076

  5. High energy approximations in quantum field theory

    International Nuclear Information System (INIS)

    Orzalesi, C.A.

    1975-01-01

    New theoretical methods in hadron physics based on a high-energy perturbation theory are discussed. The approximated solutions to quantum field theory obtained by this method appear to be sufficiently simple and rich in structure to encourage hadron dynamics studies. Operator eikonal form for field - theoretic Green's functions is derived and discussion is held on how the eikonal perturbation theory is to be renormalized. This method is extended to massive quantum electrodynamics of scalar charged bosons. Possible developments and applications of this theory are given [pt

  6. Relaxational dissipation of magnetic field energy in a rarefied plasma

    International Nuclear Information System (INIS)

    Vekshtejn, G.E.

    1987-01-01

    A mechanism of solar corona plasma heating connected with relaxation of a magnetic configuration in the corona to the state of the magnetic energy minimum at restrictions imposed by high conductivity of a medium is considered. Photospheric plasma pulsations leading to generation of longitudinal currents in the corona are in this case energy sources. The excess magnetic energy of these currents is dissipated as a result of reclosing of force lines of the magnetic field in narrow current layers. Plasmaturbulence related to the process of magnetic reclosing is phenomenologically described in this case by introducing certain characteristic time of relaxation. Such an approach permits to relate the plasma heating energy with parameters of photospheric motions in the framework of a simple model of the magnetic field

  7. Interacting diffusive unified dark energy and dark matter from scalar fields

    Energy Technology Data Exchange (ETDEWEB)

    Benisty, David; Guendelman, E.I. [Ben Gurion University of the Negev, Department of Physics, Beersheba (Israel)

    2017-06-15

    Here we generalize ideas of unified dark matter-dark energy in the context of two measure theories and of dynamical space time theories. In two measure theories one uses metric independent volume elements and this allows one to construct unified dark matter-dark energy, where the cosmological constant appears as an integration constant associated with the equation of motion of the measure fields. The dynamical space-time theories generalize the two measure theories by introducing a vector field whose equation of motion guarantees the conservation of a certain Energy Momentum tensor, which may be related, but in general is not the same as the gravitational Energy Momentum tensor. We propose two formulations of this idea: (I) by demanding that this vector field be the gradient of a scalar, (II) by considering the dynamical space field appearing in another part of the action. Then the dynamical space time theory becomes a theory of Diffusive Unified dark energy and dark matter. These generalizations produce non-conserved energy momentum tensors instead of conserved energy momentum tensors which leads at the end to a formulation of interacting DE-DM dust models in the form of a diffusive type interacting Unified dark energy and dark matter scenario. We solved analytically the theories for perturbative solution and asymptotic solution, and we show that the ΛCDM is a fixed point of these theories at large times. Also a preliminary argument as regards the good behavior of the theory at the quantum level is proposed for both theories. (orig.)

  8. Dark energy and bouncing universe from k-fields

    International Nuclear Information System (INIS)

    Kang, Jin U

    2009-01-01

    In this thesis we consider some cosmological implications of k-fields, which are general scalar fields with non-canonical kinetic terms in the action. Cosmological scenarios with k-essence are invoked in order to explain the observed late-time acceleration of the universe. These scenarios avoid the need for fine-tuned initial conditions (the ''coincidence problem'') because of the attractor-like dynamics of the k-essence field φ. We carry out a comprehensive study of attractor-like cosmological solutions (''trackers'') involving a k-essence scalar field φ and another matter component. The result of this study is a complete classification of k-essence Lagrangians that admit asymptotically stable tracking solutions, among all Lagrangians of the form p=K(φ)L(X). Using this classification, we select the class of models that describe the late-time acceleration and avoid the coincidence problem through the tracking mechanism. In the context of k-essence cosmology, the superluminal epoch does not lead to causality violations. We discuss the implications of superluminal signal propagation for possible causality violations in Lorentz-invariant field theories. Another application of k-fields was made in the new ekpyrotic scenario that attempts to solve the big-bang singularity problem by involving violation of the null energy condition in a model which combines the ekpyrotic/cyclic scenario with the ghost condensate theory and the curvation mechanism of production of adiabatic perturbations of metric. The Lagrangian of this theory, as well as of the ghost condensate model, contains a term with higher derivatives, which was added to the theory to stabilize its vacuum state. We find that this term may affect the dynamics of the cosmological evolution. Moreover, after a proper quantization, this term results in the existence of a new ghost field with negative energy, which leads to a catastrophic vacuum instability. We explain why one cannot treat this dangerous term as a

  9. Dark energy and bouncing universe from k-fields

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jin U

    2009-09-11

    In this thesis we consider some cosmological implications of k-fields, which are general scalar fields with non-canonical kinetic terms in the action. Cosmological scenarios with k-essence are invoked in order to explain the observed late-time acceleration of the universe. These scenarios avoid the need for fine-tuned initial conditions (the ''coincidence problem'') because of the attractor-like dynamics of the k-essence field {phi}. We carry out a comprehensive study of attractor-like cosmological solutions (''trackers'') involving a k-essence scalar field {phi} and another matter component. The result of this study is a complete classification of k-essence Lagrangians that admit asymptotically stable tracking solutions, among all Lagrangians of the form p=K({phi})L(X). Using this classification, we select the class of models that describe the late-time acceleration and avoid the coincidence problem through the tracking mechanism. In the context of k-essence cosmology, the superluminal epoch does not lead to causality violations. We discuss the implications of superluminal signal propagation for possible causality violations in Lorentz-invariant field theories. Another application of k-fields was made in the new ekpyrotic scenario that attempts to solve the big-bang singularity problem by involving violation of the null energy condition in a model which combines the ekpyrotic/cyclic scenario with the ghost condensate theory and the curvation mechanism of production of adiabatic perturbations of metric. The Lagrangian of this theory, as well as of the ghost condensate model, contains a term with higher derivatives, which was added to the theory to stabilize its vacuum state. We find that this term may affect the dynamics of the cosmological evolution. Moreover, after a proper quantization, this term results in the existence of a new ghost field with negative energy, which leads to a catastrophic vacuum instability. We explain

  10. Restrictions on Possible Forms of Classical Matter Fields Carrying no Energy

    International Nuclear Information System (INIS)

    Sokolowski, L.M.

    2004-01-01

    It is postulated in general relativity that the matter energy-momentum tensor vanishes if and only if all the matter fields vanish. In classical Lagrangian field theory the energy and momentum density are described by the variational (symmetric) energy-momentum tensor (named the stress tensor) and a priori it might occur that for some systems the tensor is identically to zero for all field configurations whereas evolution of the system is subject to deterministic Lagrange equations of motion. Such a system would not generate its own gravitational field. To check if these systems can exist in the framework of classical field theory we find a relationship between the stress tensor and the Euler operator (i.e. the Lagrange field equations). We prove that if a system of interacting scalar fields (the number of fields cannot exceed the spacetime dimension d) or a single vector field (in spacetimes with d even) has the stress tensor such that its divergence is identically zero (i.e. ''on and of shell''), then the Lagrange equations of motion hold identically too. These systems have then no propagation equations at all and should be regarded as unphysical. Thus nontrivial field equations require the stress tensor be nontrivial too. This relationship between vanishing (of divergence) of the stress tensor and of the Euler operator breaks down if the number of fields is greater than d. We show on concrete examples that a system of n > d interacting scalars or two interacting vector fields can have the stress tensor equal identically to zero while their propagation equations are nontrivial. This means that non-self-gravitating (and yet detectable) field systems are in principle admissible. Their equations of motion are, however, in some sense degenerate. We also show, that for a system of arbitrary number of interacting scalar fields or for a single vector field (in some specific spacetimes in the latter case), if the stress tensor is not identically zero, then it cannot

  11. Individual monitoring in high-energy stray radiation fields

    International Nuclear Information System (INIS)

    Hoefert, M.; Stevenson, G.R.

    1995-01-01

    Due to the lack of passive or active devices that could be considered as personal dosemeters in high-energy stray fields one can at present only perform individual monitoring around high energy accelerators. Of all detectors currently available it is shown that the NTA film is the most suitable method for individually monitoring the neutron exposure of more than 3000 persons regularly, reliably, and cost effectively like at CERN. (author)

  12. Low-energy limit of two-scale field theories

    International Nuclear Information System (INIS)

    Leon, J.; Perez-Mercader, J.; Sanchez, M.F.

    1991-01-01

    We present a full and self-contained discussion of the decoupling theorem applied to several general models in four-dimensional field theory. We compute in each case the low-energy effective action and show the explicit one-loop expressions for each of the effective parameters. We find that for suitable conditions one can always build an effective low-energy theory where the conditions of the decoupling theorem are satisfied

  13. ENEA programm in the field of renewable energy sources

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, G; Ambrosini, G

    1989-09-01

    In consideration of Italy's strong dependence on imported energy and in view of the targets established by the Italian National Energy Plan, renewable sources, especially solar, are expected to play a strategic role in Italy, due to Italy's favourable geographical position. The Italian Energy Plan has allocated a central task to ENEA (Italian Commission for Alternative Energy Sources), that has to take care of research and development activities, pursue demonstration programs, promote Italian industry for the development of technologies in the energy sector and finally to qualify the Italian industry. ENEA has also the task to provide advice and support to the Public Administration in initiatives in the field of new types of energy and energy saving.

  14. Magnetic field effects on runaway electron energy deposition in plasma facing materials and components

    International Nuclear Information System (INIS)

    Niemer, K.A.; Gilligan, J.G.

    1992-01-01

    This paper reports magnetic field effects on runaway electron energy deposition in plasma facing materials and components is investigated using the Integrated TIGER Series. The Integrated TIGER Series is a set of time-independent coupled electron/photon Monte Carlo transport codes which perform photon and electron transport, with or without macroscopic electric and magnetic fields. A three-dimensional computational model of 100 MeV electrons incident on a graphite block was used to simulate runawayelectrons striking a plasma facing component at the edge of a tokamak. Results show that more energy from runaway electrons will be deposited in a material that is in the presence of a magnetic field than in a material that is in the presence of no field. For low angle incident runaway electrons in a strong magnetic field, the majority of the increased energy deposition is near the material surface with a higher energy density. Electrons which would have been reflected with no field, orbit the magnetic field lines and are redeposited in the material surface, resulting in a substantial increase in surface energy deposition. Based on previous studies, the higher energy deposition and energy density will result in higher temperatures which are expected to cause more damage to a plasma facing component

  15. Luminescent tracks of high-energy photoemitted electrons accelerated by plasmonic fields

    Directory of Open Access Journals (Sweden)

    Di Vece Marcel

    2015-12-01

    Full Text Available The emission of an electron from a metal nanostructure under illumination and its subsequent acceleration in a plasmonic field forms a platform to extend these phenomena to deposited nanoparticles, which can be studied by state-of-the-art confocal microscopy combined with femtosecond optical excitation. The emitted and accelerated electrons leave defect tracks in the immersion oil, which can be revealed by thermoluminescence. These photographic tracks are read out with the confocal microscope and have a maximum length of about 80 μm, which corresponds to a kinetic energy of about 100 keV. This energy is consistent with the energy provided by the intense laser pulse combined with plasmonic local field enhancement. The results are discussed within the context of the rescattering model by which electrons acquire more energy. The visualization of electron tracks originating from plasmonic field enhancement around a gold nanoparticle opens a new way to study with confocal microscopy both the plasmonic properties of metal nano objects as well as high energy electron interaction with matter.

  16. Modelling of the Global Geopotential Energy & Stress Field

    DEFF Research Database (Denmark)

    Schiffer, Christian; Nielsen, S.B.

    Lateral density and topography variations yield in and important contribution to the lithospheric stress field. The leading quantity is the Geopotential Energy, the integrated lithostatic pressure in a rock column. The horizontal gradient of this quantity is related to horizontal stresses through...... the Equations of equilibrium of stresses. The Geopotential Energy furthermore can be linearly related to the Geoid under assumption of local isostasy. Satellite Geoid measurements contain, however, also non-isostatic deeper mantle responses of long wavelength. Unfortunately, high-pass filtering of the Geoid...... flow in the presence of local isostasy and a steady state geotherm. Subsequently we use a FEM code to solve the Equations of equilibrium of stresses for a three dimensional elastic shell. The modelled results are shown and compared with the global stress field and other publications....

  17. Measuring scientific research in emerging nano-energy field

    Science.gov (United States)

    Guan, Jiancheng; Liu, Na

    2014-04-01

    The purpose of this paper is to comprehensively explore scientific research profiles in the field of emerging nano-energy during 1991-2012 based on bibliometrics and social network analysis. We investigate the growth pattern of research output, and then carry out across countries/regions comparisons on research performances. Furthermore, we examine scientific collaboration across countries/regions by analyzing collaborative intensity and networks in 3- to 4-year intervals. Results indicate with an impressively exponential growth pattern of nano-energy articles, the world share of scientific "giants," such as the USA, Germany, England, France and Japan, display decreasing research trends, especially in the USA. Emerging economies, including China, South Korea and India, exhibit a rise in terms of the world share, illustrating strong development momentum of these countries in nano-energy research. Strikingly, China displays a remarkable rise in scientific influence rivaling Germany, Japan, France, and England in the last few years. Finally, the scientific collaborative network in nano-energy research has expanded steadily. Although the USA and several major European countries play significantly roles on scientific collaboration, China and South Korea exert great influence on scientific collaboration in recent years. The findings imply that emerging economies can earn competitive advantages in some emerging fields by properly engaging a catch-up strategy.

  18. Vacuum field energy and spontaneous emission in anomalously dispersive cavities

    International Nuclear Information System (INIS)

    Bradshaw, Douglas H.; Di Rosa, Michael D.

    2011-01-01

    Anomalously dispersive cavities, particularly white-light cavities, may have larger bandwidth to finesse ratios than their normally dispersive counterparts. Partly for this reason, they have been proposed for use in laser interferometer gravitational-wave observatory (LIGO)-like gravity-wave detectors and in ring-laser gyroscopes. In this paper we analyze the quantum noise associated with anomalously dispersive cavity modes. The vacuum field energy associated with a particular cavity mode is proportional to the cavity-averaged group velocity of that mode. For anomalously dispersive cavities with group index values between 1 and 0, this means that the total vacuum field energy associated with a particular cavity mode must exceed (ℎ/2π)ω/2. For white-light cavities in particular, the group index approaches zero and the vacuum field energy of a particular spatial mode may be significantly enhanced. We predict enhanced spontaneous emission rates into anomalously dispersive cavity modes and broadened laser linewidths when the linewidth of intracavity emitters is broader than the cavity linewidth.

  19. Energy of Force-Free Magnetic Fields in Relation to Coronal Mass Ejections; TOPICAL

    International Nuclear Information System (INIS)

    G.S. Choe; C.Z. Cheng

    2002-01-01

    In typical observations of coronal mass ejections (CMEs), a magnetic structure of a helmet-shaped closed configuration bulges out and eventually opens up. However, a spontaneous transition between these field configurations has been regarded to be energetically impossible in force-free fields according to the Aly-Sturrock theorem. The theorem states that the maximum energy state of force-free fields with a given boundary normal field distribution is the open field. The theorem implicitly assumes the existence of the maximum energy state, which may not be taken for granted. In this study, we have constructed force-free fields containing tangential discontinuities in multiple flux systems. These force-free fields can be generated from a potential field by footpoint motions that do not conserve the boundary normal field distribution. Some of these force-free fields are found to have more magnetic energy than the corresponding open fields. The constructed force-free configurations are compared with observational features of CME-bearing active regions. Possible mechanisms of CMEs are also discussed

  20. Continuity equations for bound electromagnetic field and the electromagnetic energy-momentum tensor

    International Nuclear Information System (INIS)

    Kholmetskii, A L; Missevitch, O V; Yarman, T

    2011-01-01

    We analyze the application of the Poynting theorem to the bound (velocity-dependent) electromagnetic (EM) field and show that an often-used arbitrary elimination of the term of self-interaction in the product j·E (where j is the current density and E the electric field) represents, in general, an illegitimate operation, which leads to incorrect physical consequences. We propose correct ways of eliminating the terms of self-interaction from the Poynting theorem to transform it into the form that is convenient for problems with bound EM field, which yield the continuity equations for the proper EM energy density, the interaction part of EM energy density and the total EM energy density of bound fields, respectively. These equations indicate the incompleteness of the common EM energy-momentum tensor, and in our analysis, we find a missed term in its structure, which makes its trace non-vanished. Some implications of these results are discussed, in particular, in view of the notion of EM mass of charged particles.

  1. Energy Flow Exciting Field-Aligned Current at Substorm Expansion Onset

    Science.gov (United States)

    Ebihara, Y.; Tanaka, T.

    2017-12-01

    At substorm expansion onset, upward field-aligned currents (FACs) increase abruptly, and a large amount of electromagnetic energy starts to consume in the polar ionosphere. A question arises as to where the energy comes from. Based on the results obtained by the global magnetohydrodynamics simulation, we present energy flow and energy conversion associated with the upward FACs that manifest the onset. Our simulations show that the cusp/mantle region transmits electromagnetic energy to almost the entire region of the magnetosphere when the interplanetary magnetic field is southward. Integral curve of the Poynting flux shows a spiral moving toward the ionosphere, probably suggesting the pathway of electromagnetic energy from the cusp/mantle dynamo to the ionosphere. The near-Earth reconnection initiates three-dimensional redistribution of the magnetosphere. Flow shear in the near-Earth region results in the generation of the near-Earth dynamo and the onset FACs. The onset FACs are responsible to transport the electromagnetic energy toward the Earth. In the near-Earth region, the electromagnetic energy coming from the cusp/mantle dynamo is converted to the kinetic energy (known as bursty bulk flow) and the thermal energy (associated with high-pressure region in the inner magnetosphere). Then, they are converted to the electromagnetic energy associated with the onset FACs. A part of electromagnetic energy is stored in the lobe region during the growth phase. The release of the stored energy, together with the continuously supplied energy from the cusp/mantle dynamo, contributes to the energy supply to the ionosphere during the expansion phase.

  2. Energy and polarization of the telluric field in correlation with seismic activity in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Vargemezis, G.; Tsokas, G. N. [Geophysical Laboratory of Thessaloniki, Thessaloniki (Greece); Zlotnicki, J. [Observatoire de Physique du Globe de Clermont-Ferrand, Clermont-Ferrand (France)

    2001-04-01

    Many attempts have been made to disclose anomalous changes of the electromagnetic field in relation with tectonic earthquakes. It was tentatively developed a new approach based on the energy and polarity of the electric field, and apply this method to the seismicity in Greece. The study of the parameters of the horizontal electric field is realized in a time interval of five years. The data allows the study of long-term variations of the field. Further, it was examined the possible relation of the geoelectric activity with long distance seismicity (up to 500 km). The energy of the electric signal was estimated and correlated with the logarithm of the seismic moment (M{sub 0}). The values of the seismic moment estimated for each earthquake were summed for daily intervals, and the logarithm of the sum was computed. The same process was applied to the energy of the geoelectric field. Then, a correlation was attempted between the energy of the geoelectric field and the seismic moment referring to daily intervals. In two cases, changes in the energy of the horizontal geoelectric field were observed before the burst of the seismic activity. The energy of the telluric field increased several months before the burst of seismic activity and recovered right after the occurrence of the mainshocks. The hodograms of the horizontal geoelectric field show polarization changes regardless of the magnetic field. This is possibly attributed to the process of generation of electric currents before major earthquakes. Due to high and continuous regional seismicity in Greece, it was impossible to attribute the response of the polarization to the activation of specific seismic areas. It seems that the long-term energy variations of the horizontal geoelectric field as well as the polarization could be used in tandem with other possible precursors in order to contribute to earthquake prediction studies.

  3. Relation between field energy and RMS emittance in intense particle beams

    International Nuclear Information System (INIS)

    Wangler, T.P.; Crandall, K.R.; Mills, R.S.; Reiser, M.

    1985-01-01

    An equation is presented for continuous beams with azimuthal symmetry and continuous linear focusing, which expresses a relationship between the rate of change for squared rms emittance and the rate of change for a quantity we call the nonlinear field energy. The nonlinear field energy depends on the shape of the charge distribution and corresponds to the residual field energy possessed by beams with nonuniform charge distributions. The equation can be integrated for the case of an rms matched beam to yield a formula for space-charge-induced emittance growth that we have tested numerically for a variety of initial distributions. The results provide a framework for discussing the scaling of rms emittance growth and an explanation for the well-established lower limit on output emittance. 15 refs., 4 figs

  4. Research on energy use of field plants; Peltokasvien energiakaeyttoeae koskeva tutkimus

    Energy Technology Data Exchange (ETDEWEB)

    Tauriainen, J. [Commission of Agricultural Research, Helsinki (Finland). Finnish Ministry of Agriculture and Forestry

    1996-12-31

    Production of energy plants on set aside areas of peat production has risen to a subject of discussions during past few years. The field area becoming useless has been estimated to be, before the EU-membership, hundreds of thousands of hectares, 500 000 - 800 000 ha. Alternate usage will be needed for the set aside field areas because the profitability of plant cultivation is diminishing remarkable, and new possibilities for additional income are sought in Finnish farms. Research on field biomasses started in the national Bioenergy Research Programme in 1995. The number of projects was five, funded mainly by the Finnish Ministry of Agriculture and Forestry. The projects carried out in 1995 were: (1) Demonstration of the cultivation of Rape and Reed canary grass at present oil mills to fuel-oil, paper fibers and flash-pyrolysis oil as a large non-food production; (2) Cultivation of energy plants at peat production areas and the applicability of the bioenergy for different purposes; (3) Production of biomass in fields and the utilization of it for energy production; (4) Fractionation of different parts of the field plants and the development of the sorting technologies; and (5) Upgraded fuel from reed canary grass (an international task of the EU/AIR programme). In addition to these, the Agro-fiber research, funded totally by the Ministry of Agriculture and Forestry, will serve the purposes of the energy sector. The research is concentrated on the investigation of the fundamentals of the pulping applications of the field biomasses

  5. Examination of employment in the atomic energy field

    International Nuclear Information System (INIS)

    Baker, J.G.

    1978-02-01

    This study, which focuses on the years 1968--1975, singles out important employment trends in the atomic energy field and develops causal explanations for these trends. The study also provides a descriptive profile of employment in the field. Employment in the atomic energy field has grown from 138,519 in 1963 to 197,466 in 1975, an annual rate of 3.0 percent. The deployment of scientists, engineers, and technicians in the government-owned, contractor-operated (GOCO) sector changed little from 1968 to 1975. Private sector deployment altered considerably, with a large increase. Within the scientist group, the GOCO sector employment by field has changed little from 1968 to 1975. Private sector scientists have seen considerable alteration of their employment. There has been little change in the employment shares of engineering fields in the GOCO sector for the 1968 to 1975 period. Private sector engineers have seen much greater change, with civil engineers increasing their share 6% to 11%. Of all GOCO technicians, physical science technicians have increased their employment share from 12% to 17%. Of all private sector technicians, draftsmen have increased their share from 29% to 37% and reactor operators from 4% to 7%. Total employment in the field is shifting toward smaller firms. Employment by region has changed considerably in the private sector from 1968 to 1975. GOCO regional employment has also changed. The percentage of scientists and engineers involved in research and development has declined from 68% in 1968 to 39% in 1975. Three private sector industrial segments--reactor design and manufacturing, nuclear facilities design and engineering, and operation and maintenance of reactors--have experienced tremendous growth from 1968 to 1975. 8 figures, 32 tables

  6. Field-dependent molecular ionization and excitation energies: Implications for electrically insulating liquids

    Directory of Open Access Journals (Sweden)

    N. Davari

    2014-03-01

    Full Text Available The molecular ionization potential has a relatively strong electric-field dependence as compared to the excitation energies which has implications for electrical insulation since the excited states work as an energy sink emitting light in the UV/VIS region. At some threshold field, all the excited states of the molecule have vanished and the molecule is a two-state system with the ground state and the ionized state, which has been hypothesized as a possible origin of different streamer propagation modes. Constrained density-functional theory is used to calculate the field-dependent ionization potential of different types of molecules relevant for electrically insulating liquids. The low singlet-singlet excitation energies of each molecule have also been calculated using time-dependent density functional theory. It is shown that low-energy singlet-singlet excitation of the type n → π* (lone pair to unoccupied π* orbital has the ability to survive at higher fields. This type of excitation can for example be found in esters, diketones and many color dyes. For alkanes (as for example n-tridecane and cyclohexane on the other hand, all the excited states, in particular the σ → σ* excitations vanish in electric fields higher than 10 MV/cm. Further implications for the design of electrically insulating dielectric liquids based on the molecular ionization potential and excitation energies are discussed.

  7. Magnetized retarding field energy analyzer measuring the particle flux and ion energy distribution of both positive and negative ions

    International Nuclear Information System (INIS)

    Rafalskyi, Dmytro; Aanesland, Ane; Dudin, Stanislav

    2015-01-01

    This paper presents the development of a magnetized retarding field energy analyzer (MRFEA) used for positive and negative ion analysis. The two-stage analyzer combines a magnetic electron barrier and an electrostatic ion energy barrier allowing both positive and negative ions to be analyzed without the influence of electrons (co-extracted or created downstream). An optimal design of the MRFEA for ion-ion beams has been achieved by a comparative study of three different MRFEA configurations, and from this, scaling laws of an optimal magnetic field strength and topology have been deduced. The optimal design consists of a uniform magnetic field barrier created in a rectangular channel and an electrostatic barrier consisting of a single grid and a collector placed behind the magnetic field. The magnetic barrier alone provides an electron suppression ratio inside the analyzer of up to 6000, while keeping the ion energy resolution below 5 eV. The effective ion transparency combining the magnetic and electrostatic sections of the MRFEA is measured as a function of the ion energy. It is found that the ion transparency of the magnetic barrier increases almost linearly with increasing ion energy in the low-energy range (below 200 eV) and saturates at high ion energies. The ion transparency of the electrostatic section is almost constant and close to the optical transparency of the entrance grid. We show here that the MRFEA can provide both accurate ion flux and ion energy distribution measurements in various experimental setups with ion beams or plasmas run at low pressure and with ion energies above 10 eV

  8. Experimental analysis of a new retarding field energy analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yu-Xiang [Shanghai Institute of Mechanical and Electrical Engineering, No. 3888, Yuanjiang Road, Minhang District, Shanghai 201109 (China); Institute of Electronics, Chinese Academy of Sciences, No. 19, North 4th Ring Road West, Haidian District, Beijing 100190 (China); Liu, Shu-Qing; Li, Xian-Xia; Shen, Hong-Li; Huang, Ming-Guang [Institute of Electronics, Chinese Academy of Sciences, No. 19, North 4th Ring Road West, Haidian District, Beijing 100190 (China); Liu, Pu-Kun, E-mail: pkliu@pku.edu.cn [School of Electronics Engineering and Computer Science, Peking University, No. 5, Yiheyuan Road, Haidian District, Beijing 100871 (China)

    2015-06-11

    In this paper, a new compact retarding field energy analyzer (RFEA) is designed for diagnosing electron beams of a K-band space travelling-wave tube (TWT). This analyzer has an aperture plate to sample electron beams and a cylindrical electrode to overcome the defocusing effects. The front end of the analyzer constructed as a multistage depression collector (MDC) structure is intended to shape the field to prevent electrons from being accelerated to escape. The direct-current (DC) beams of the K-band space TWTs with the removing MDC can be investigated on the beam measurement system. The current density distribution of DC beams is determined by the analyzer, while the anode voltage and helix voltage of the TWTs are 7000 V and 6850 V, respectively. The current curve’s slope effect due to the reflection of secondary electrons on the copper collector of the analyzer is discussed. The experimental analysis shows this RFEA has a good energy resolution to satisfy the requirement of beam measurement. - Highlights: • A new retarding field energy analyzer (RFEA) is designed to diagnose the electron beam of a K-band space TWT. • The current density distribution of direct-current beam is determined. • The reflection effect of secondary electrons on the copper collector of the analyzer is discussed.

  9. Enhancement of electron energy during vacuum laser acceleration in an inhomogeneous magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Saberi, H.; Maraghechi, B., E-mail: behrouz@aut.ac.ir [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)

    2015-03-15

    In this paper, the effect of a stationary inhomogeneous magnetic field on the electron acceleration by a high intensity Gaussian laser pulse is investigated. A focused TEM (0,0) laser mode with linear polarization in the transverse x-direction that propagates along the z-axis is considered. The magnetic field is assumed to be stationary in time, but varies longitudinally in space. A linear spatial profile for the magnetic field is adopted. In other words, the axial magnetic field increases linearly in the z-direction up to an optimum point z{sub m} and then becomes constant with magnitude equal to that at z{sub m}. Three-dimensional single-particle simulations are performed to find the energy and trajectory of the electron. The electron rotates around and stays near the z-axis. It is shown that with a proper choice of the magnetic field parameters, the electron will be trapped at the focus of the laser pulse. Because of the cyclotron resonance, the electron receives enough energy from the laser fields to be accelerated to relativistic energies. Using numerical simulations, the criteria for optimum regime of the acceleration mechanism is found. With the optimized parameters, an electron initially at rest located at the origin achieves final energy of γ=802. The dynamics of a distribution of off-axis electrons are also investigated in which shows that high energy electrons with small energy and spatial spread can be obtained.

  10. Vacuum energy of the electromagnetic field in a rotating system

    International Nuclear Information System (INIS)

    Hacyan, S.; Sarmiento, A.

    1986-01-01

    The vacuum energy of the electromagnetic field is calculated for a uniformly rotating observer. The spectrum of vacuum fluctuations is composed of the zero-point energy with a modified density of states and a contribution due to the rotation which is not thermal. (orig.)

  11. The continuous tower of scalar fields as a system of interacting dark matter–dark energy

    International Nuclear Information System (INIS)

    Santos, Paulo

    2015-01-01

    This paper aims to introduce a new parameterisation for the coupling Q in interacting dark matter and dark energy models by connecting said models with the Continuous Tower of Scalar Fields model. Based upon the existence of a dark matter and a dark energy sectors in the Continuous Tower of Scalar Fields, a simplification is considered for the evolution of a single scalar field from the tower, validated in this paper. This allows for the results obtained with the Continuous Tower of Scalar Fields model to match those of an interacting dark matter–dark energy system, considering that the energy transferred from one fluid to the other is given by the energy of the scalar fields that start oscillating at a given time, rather than considering that the energy transference depends on properties of the whole fluids that are interacting.

  12. Energy-momentum tensor in the quantum field theory

    International Nuclear Information System (INIS)

    Azakov, S.I.

    1977-01-01

    An energy-momentum tensor in the scalar field theory is built. The tensor must satisfy the finiteness requirement of the Green function. The Green functions can always be made finite by renormalizations in the S-matrix by introducing counter terms into the Hamiltonian (or Lagrangian) of the interaction. Such a renormalization leads to divergencies in the Green functions. Elimination of these divergencies requires the introduction of new counter terms, which must be taken into account in the energy-momentum tensor

  13. Benchmark Modeling of the Near-Field and Far-Field Wave Effects of Wave Energy Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rhinefrank, Kenneth E; Haller, Merrick C; Ozkan-Haller, H Tuba

    2013-01-26

    This project is an industry-led partnership between Columbia Power Technologies and Oregon State University that will perform benchmark laboratory experiments and numerical modeling of the near-field and far-field impacts of wave scattering from an array of wave energy devices. These benchmark experimental observations will help to fill a gaping hole in our present knowledge of the near-field effects of multiple, floating wave energy converters and are a critical requirement for estimating the potential far-field environmental effects of wave energy arrays. The experiments will be performed at the Hinsdale Wave Research Laboratory (Oregon State University) and will utilize an array of newly developed Buoys' that are realistic, lab-scale floating power converters. The array of Buoys will be subjected to realistic, directional wave forcing (1:33 scale) that will approximate the expected conditions (waves and water depths) to be found off the Central Oregon Coast. Experimental observations will include comprehensive in-situ wave and current measurements as well as a suite of novel optical measurements. These new optical capabilities will include imaging of the 3D wave scattering using a binocular stereo camera system, as well as 3D device motion tracking using a newly acquired LED system. These observing systems will capture the 3D motion history of individual Buoys as well as resolve the 3D scattered wave field; thus resolving the constructive and destructive wave interference patterns produced by the array at high resolution. These data combined with the device motion tracking will provide necessary information for array design in order to balance array performance with the mitigation of far-field impacts. As a benchmark data set, these data will be an important resource for testing of models for wave/buoy interactions, buoy performance, and far-field effects on wave and current patterns due to the presence of arrays. Under the proposed project we will initiate

  14. Continuity equations for bound electromagnetic field and the electromagnetic energy-momentum tensor

    Energy Technology Data Exchange (ETDEWEB)

    Kholmetskii, A L [Department of Physics, Belarusian State University, 4 Nezavisimosti Avenue, 220030 Minsk (Belarus); Missevitch, O V [Institute for Nuclear Problems, Belarusian State University, 11 Bobruiskaya Street, 220030 Minsk (Belarus); Yarman, T, E-mail: khol123@yahoo.com [Department of Engineering, Okan University, Akfirat, Istanbul, Turkey and Savronik, Eskisehir (Turkey)

    2011-05-01

    We analyze the application of the Poynting theorem to the bound (velocity-dependent) electromagnetic (EM) field and show that an often-used arbitrary elimination of the term of self-interaction in the product j{center_dot}E (where j is the current density and E the electric field) represents, in general, an illegitimate operation, which leads to incorrect physical consequences. We propose correct ways of eliminating the terms of self-interaction from the Poynting theorem to transform it into the form that is convenient for problems with bound EM field, which yield the continuity equations for the proper EM energy density, the interaction part of EM energy density and the total EM energy density of bound fields, respectively. These equations indicate the incompleteness of the common EM energy-momentum tensor, and in our analysis, we find a missed term in its structure, which makes its trace non-vanished. Some implications of these results are discussed, in particular, in view of the notion of EM mass of charged particles.

  15. Managing human resources in the field of nuclear energy

    International Nuclear Information System (INIS)

    2009-01-01

    The nuclear field, comprising industry, government authorities, regulators, R and D organizations and educational institutions, relies heavily on a specialized, highly trained and motivated workforce for its sustainability. An ageing workforce, declining student enrolment and the resultant risk of losing accumulated nuclear knowledge and experience for expanding or newly established nuclear programmes are all serious challenges that influence the management of human resources (HR) in the nuclear field. The management of human resources requires particular attention in the field of nuclear energy, both because of the high standards of performance expected in this field and the considerable time needed to develop such specialists. The peaceful uses of nuclear energy were primarily developed during the second half of the twentieth century. The nuclear field is now at a mature stage of development, with those who were pioneers in the field having retired and their responsibilities handed over to subsequent generations. For those aspects of the nuclear field related to nuclear power, a great deal of effort has been devoted to managing and continuing to improve the safety and operational performance of existing facilities. However, indications are that the next decades may see considerable expansion to meet increasing energy needs, while responding to concerns about the environment, including global warming. Thus, in the nuclear field, those Member States with existing nuclear power programmes may be forced to replace a large part of their current workforce, while also attracting, recruiting and preparing a fresh workforce for the new facilities being planned. At the same time, those who will be initiating nuclear power programmes, or other peaceful applications, will be developing HR for their programmes. In the past, the development of human resources in the nuclear field has depended on considerable support from organizations in the country of origin of the technology

  16. Field use of D218O to measure energy expenditure of soldiers at different energy intakes

    International Nuclear Information System (INIS)

    DeLany, J.P.; Schoeller, D.A.; Hoyt, R.W.; Askew, E.W.; Sharp, M.A.

    1989-01-01

    To test the application of doubly labeled water under adverse field conditions, energy expenditures of 16 special operations soldiers were measured during a 28-day field training exercise. Subjects were matched by fat-free mass and divided equally between an ad libitum ready-to-eat meal diet and a 2,000 kcal/day lightweight ration. Subjects recorded intakes daily, and body composition was measured before and after the exercise. At the beginning of the study, subjects moved to a new northerly location and, therefore, a new water supply. To compensate for this, a group of soldiers who did not receive heavy water was followed to measure isotopic base-line changes. Energy expenditure by doubly labeled water was in agreement with intake/balance (3,400 ± 260 vs. 3,230 ± 520 kcal/day). The overall coefficient of variation of energy expenditure by doubly labeled water was half that of intake/balance (7.6 vs. 16.1%). The coefficient of variation of repeat measures with doubly labeled water was 7.3%. Energy expenditure of the ready-to-eat meal group, 3,540 ± 180 kcal/day, was not significantly different from the lightweight ration group, 3,330 ± 301 kcal/day. Doubly labeled water was valid under field conditions

  17. Energy conservation law for randomly fluctuating electromagnetic fields

    International Nuclear Information System (INIS)

    Gbur, G.; Wolf, E.; James, D.

    1999-01-01

    An energy conservation law is derived for electromagnetic fields generated by any random, statistically stationary, source distribution. It is shown to provide insight into the phenomenon of correlation-induced spectral changes. The results are illustrated by an example. copyright 1999 The American Physical Society

  18. Field Assessment of Energy Audit Tools for Retrofit Programs

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, J. [Univ. of Minnesota, St. Paul, MN (United States); Bohac, D. [Univ. of Minnesota, St. Paul, MN (United States); Nelson, C. [Univ. of Minnesota, St. Paul, MN (United States); Smith, I. [Univ. of Minnesota, St. Paul, MN (United States)

    2013-07-01

    This project focused on the use of home energy ratings as a tool to promote energy retrofits in existing homes. A home energy rating provides a quantitative appraisal of a home’s energy performance, usually compared to a benchmark such as the average energy use of similar homes in the same region. Rating systems based on energy performance models, the focus of this report, can establish a home’s achievable energy efficiency potential and provide a quantitative assessment of energy savings after retrofits are completed, although their accuracy needs to be verified by actual measurement or billing data. Ratings can also show homeowners where they stand compared to their neighbors, thus creating social pressure to conform to or surpass others. This project field-tested three different building performance models of varying complexity, in order to assess their value as rating systems in the context of a residential retrofit program: Home Energy Score, SIMPLE, and REM/Rate.

  19. The Analytical Potential Energy Function of NH Radical Molecule in External Electric Field

    International Nuclear Information System (INIS)

    Wu Dong-Lan; Tan Bin; Wan Hui-Jun; Xie An-Dong; Ding Da-Jun

    2015-01-01

    The geometric structures of an NH radical in different external electric fields are optimized by using the density functional B3P86/cc-PV5Z method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD (T) method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect. (paper)

  20. On scalar and vector fields coupled to the energy-momentum tensor

    Science.gov (United States)

    Jiménez, Jose Beltrán; Cembranos, Jose A. R.; Sánchez Velázquez, Jose M.

    2018-05-01

    We consider theories for scalar and vector fields coupled to the energy-momentum tensor. Since these fields also carry a non-trivial energy-momentum tensor, the coupling prescription generates self-interactions. In analogy with gravity theories, we build the action by means of an iterative process that leads to an infinite series, which can be resumed as the solution of a set of differential equations. We show that, in some particular cases, the equations become algebraic and that is also possible to find solutions in the form of polynomials. We briefly review the case of the scalar field that has already been studied in the literature and extend the analysis to the case of derivative (disformal) couplings. We then explore theories with vector fields, distinguishing between gauge-and non-gauge-invariant couplings. Interactions with matter are also considered, taking a scalar field as a proxy for the matter sector. We also discuss the ambiguity introduced by superpotential (boundary) terms in the definition of the energy-momentum tensor and use them to show that it is also possible to generate Galileon-like interactions with this procedure. We finally use collider and astrophysical observations to set constraints on the dimensionful coupling which characterises the phenomenology of these models.

  1. Quantum Field Theory of Interacting Dark Matter/Dark Energy: Dark Monodromies

    CERN Document Server

    D'Amico, Guido; Kaloper, Nemanja

    2016-11-28

    We discuss how to formulate a quantum field theory of dark energy interacting with dark matter. We show that the proposals based on the assumption that dark matter is made up of heavy particles with masses which are very sensitive to the value of dark energy are strongly constrained. Quintessence-generated long range forces and radiative stability of the quintessence potential require that such dark matter and dark energy are completely decoupled. However, if dark energy and a fraction of dark matter are very light axions, they can have significant mixings which are radiatively stable and perfectly consistent with quantum field theory. Such models can naturally occur in multi-axion realizations of monodromies. The mixings yield interesting signatures which are observable and are within current cosmological limits but could be constrained further by future observations.

  2. Musikterapi ift. børn med autismediagnoser

    DEFF Research Database (Denmark)

    Holck, Ulla

    2012-01-01

    En gennemgang af nyeste forskning i musikterapi (Cochrane Reviews og RCTstudier), der viser evidens for, at musikterapi fremmer sociale færdigheder, verbal og nonverbal kommunikation samt følelsesmæssigt samspil....

  3. Energy spectrum of tearing mode turbulence in sheared background field

    Science.gov (United States)

    Hu, Di; Bhattacharjee, Amitava; Huang, Yi-Min

    2018-06-01

    The energy spectrum of tearing mode turbulence in a sheared background magnetic field is studied in this work. We consider the scenario where the nonlinear interaction of overlapping large-scale modes excites a broad spectrum of small-scale modes, generating tearing mode turbulence. The spectrum of such turbulence is of interest since it is relevant to the small-scale back-reaction on the large-scale field. The turbulence we discuss here differs from traditional MHD turbulence mainly in two aspects. One is the existence of many linearly stable small-scale modes which cause an effective damping during the energy cascade. The other is the scale-independent anisotropy induced by the large-scale modes tilting the sheared background field, as opposed to the scale-dependent anisotropy frequently encountered in traditional critically balanced turbulence theories. Due to these two differences, the energy spectrum deviates from a simple power law and takes the form of a power law multiplied by an exponential falloff. Numerical simulations are carried out using visco-resistive MHD equations to verify our theoretical predictions, and a reasonable agreement is found between the numerical results and our model.

  4. Coherent error study in a retarding field energy analyzer

    International Nuclear Information System (INIS)

    Cui, Y.; Zou, Y.; Reiser, M.; Kishek, R.A.; Haber, I.; Bernal, S.; O'Shea, P.G.

    2005-01-01

    A novel cylindrical retarding electrostatic field energy analyzer for low-energy beams has been designed, simulated, and tested with electron beams of several keV, in which space charge effects play an important role. A cylindrical focusing electrode is used to overcome the beam expansion inside the device due to space-charge forces, beam emittance, etc. In this paper, we present the coherent error analysis for this energy analyzer with beam envelope equation including space charge and emittance effects. The study shows that this energy analyzer can achieve very high resolution (with relative error of around 10 -5 ) if taking away the coherent errors by using proper focusing voltages. The theoretical analysis is compared with experimental results

  5. Thermoluminescent analyses of mean photon energy of a field

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, T. A.; De Paiva, F.; Fonseca, G.; Dalledone S, P. de T.; Yoriyaz, H., E-mail: tassio.cavalieri@usp.br [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    Nowadays a common method of dosimetry is utilize the thermoluminescent dosimetry (TLD) of LiF, where for pure gamma field is typically used the LiF or CaF{sub 2} TLDs and for mixed neutron and gamma field dosimetry is used the pair TLD-600/TLD-700. The difference between these three LiF TLDs is the amount of isotope {sup 6}Li in their composition. The isotope {sup 6}Li has a great cross section for thermal neutrons, making the TLD-600 sensitive to thermal neutrons beyond the radiation gamma. Whereas the TLD-700 is considered sensitive only for radiation gamma. Some studies showed an energetic dependence of these TLDs for gammas rays. So the goal of this work was study these energetic dependence of TLDs from the angular coefficient of their response versus dose calibration curves when they were irradiated in four fields with photons of different energies: 43 keV, 662 keV, 1.2 MeV, 3 MeV. In order to create the calibration curves TLD, it was performed three irradiations with distinct exposure times for each photon energy. These studies showed a different angular coefficient to each curve; demonstrate the energetic dependence of these TLDs. By simulation with Monte Carlo based code, MCNP-5, it was observed the deposited photon dose due to different photons energies. From these simulations, it was also possible to observe a difference of dose deposition in TLDs when they were exposed to the same dose provided from different photons energies. These work showed the previously study of photon energetic dependence of LiF TLDs. (Author)

  6. Accurate magnetic field calculations for contactless energy transfer coils

    OpenAIRE

    Sonntag, C.L.W.; Spree, M.; Lomonova, E.A.; Duarte, J.L.; Vandenput, A.J.A.

    2007-01-01

    In this paper, a method for estimating the magnetic field intensity from hexagon spiral windings commonly found in contactless energy transfer applications is presented. The hexagonal structures are modeled in a magneto-static environment using Biot-Savart current stick vectors. The accuracy of the models are evaluated by mapping the current sticks and the hexagon spiral winding tracks to a local twodimensional plane, and comparing their two-dimensional magnetic field intensities. The accurac...

  7. Field biomass as energy resource for the future; Peltobiomassat tulevaisuuden energiaresurssina

    Energy Technology Data Exchange (ETDEWEB)

    Pahkala, K.; Loetjoenen, T. (eds.)

    2012-11-01

    Bioenergy can be derived from biomasses especially produced for bioenergy or from by-products, side streams and waste from wood processing industry, agriculture and forestry, or e.g. municipal waste. In the Nordic countries and Russia forests are a natural source of bioenergy. In many other European countries forests may be too scarce for bioenergy use. Therefore field biomasses form an interesting potential source for bioenergy. Production of field biomasses for non-food purposes has been criticized, especially as there is not enough food for everyone even at present, and in the future more food has to be produced as the world population increases. We studied the field biomass potential in different European countries with different scenarios for development. 'Good development' scenario includes improvements in plant breeding and food production and processing technologies, with increasing yields and decreasing waste of food products and raw materials. 'Bad development' scenario assumes stagnating yields and little improvement in technologies in the OECD countries, and only small improvements in former Soviet Union countries. The foci of the present research were the effects of development of food production, population growth and climate change on regional potential of field biomasses for bioenergy and sustainable use of crop residues and grasses for bioenergy. The field area that could be allocated to energy crops after growing enough food for the citizens of each country depends mostly on the diet. Growing food for vegetarian diet would occupy so little field area that every country under study could set aside at least half of their field area for bioenergy purposes already at present, if the 'good development' scenario was applied. With 'bad development' scenario some of the countries would be unable to set aside fields for bioenergy production even with vegetarian diet. With affluent diet there would be little field

  8. Energy consumption in Hodgkin–Huxley type fast spiking neuron model exposed to an external electric field

    Directory of Open Access Journals (Sweden)

    K. Usha

    2016-09-01

    Full Text Available This paper evaluates the change in metabolic energy required to maintain the signalling activity of neurons in the presence of an external electric field. We have analysed the Hodgkin–Huxley type conductance based fast spiking neuron model as electrical circuit by changing the frequency and amplitude of the applied electric field. The study has shown that, the presence of electric field increases the membrane potential, electrical energy supply and metabolic energy consumption. As the amplitude of applied electric field increases by keeping a constant frequency, the membrane potential increases and consequently the electrical energy supply and metabolic energy consumption increases. On increasing the frequency of the applied field, the peak value of membrane potential after depolarization gradually decreases as a result electrical energy supply decreases which results in a lower rate of hydrolysis of ATP molecules.

  9. μ-TPC: a future standard instrument for low energy neutron field characterization

    International Nuclear Information System (INIS)

    Maire, D.; Lebreton, L.; Petit, M.; Billard, J.; Bourrion, O.; Bosson, G.; Guillaudin, O.; Lamblin, J.; Mayet, F.; Medard, J.; Muraz, J.F.; Richer, J.P.; Riffard, Q.; Santos, D.

    2013-06-01

    In order to measure energy of neutron fields, with energy ranging from 8 keV to 1 MeV, a new primary standard is being developed at the IRSN (Institute for Radioprotection and Nuclear Safety). This project, μ-TPC (Micro Time Projection Chamber), carried out in collaboration with the LPSC (Laboratoire de Physique Subatomique et de Cosmologie), is based on the nucleus recoil detector principle. The instrument will be presented with the associated method to measure the neutron energy. This article will emphasize the proton energy calibration procedure and energy measurements of a neutron field produced at 127 keV on the IRSN facility AMANDE. Finally the COMIMAC device, dedicated to the calibration, will be described. This original device, developed at the LPSC, is able to produce proton and electron beams with an accurate energy ranging from 1 keV to 50 keV. (authors)

  10. Ensuring the expert resources and education in nuclear energy field

    International Nuclear Information System (INIS)

    Pirilae, P.

    1987-01-01

    The Finnish Atomic Energy Commission has published a report ''The Situation and the Needs for Development of Education in the Nuclear Energy Field''. According to it, the needs concerning the volume of education are small and no problem for Finland. But, the problem is how to maintain the present high level of training and education within this small volume

  11. Diagnosing collisionless energy transfer using field-particle correlations: Vlasov-Poisson plasmas

    Science.gov (United States)

    Howes, Gregory G.; Klein, Kristopher G.; Li, Tak Chu

    2017-02-01

    Turbulence plays a key role in the conversion of the energy of large-scale fields and flows to plasma heat, impacting the macroscopic evolution of the heliosphere and other astrophysical plasma systems. Although we have long been able to make direct spacecraft measurements of all aspects of the electromagnetic field and plasma fluctuations in near-Earth space, our understanding of the physical mechanisms responsible for the damping of the turbulent fluctuations in heliospheric plasmas remains incomplete. Here we propose an innovative field-particle correlation technique that can be used to measure directly the secular energy transfer from fields to particles associated with collisionless damping of the turbulent fluctuations. Furthermore, this novel procedure yields information about the collisionless energy transfer as a function of particle velocity, providing vital new information that can help to identify the dominant collisionless mechanism governing the damping of the turbulent fluctuations. Kinetic plasma theory is used to devise the appropriate correlation to diagnose Landau damping, and the field-particle correlation technique is thoroughly illustrated using the simplified case of the Landau damping of Langmuir waves in a 1D-1V (one dimension in physical space and one dimension in velocity space) Vlasov-Poisson plasma. Generalizations necessary to apply the field-particle correlation technique to diagnose the collisionless damping of turbulent fluctuations in the solar wind are discussed, highlighting several caveats. This novel field-particle correlation technique is intended to be used as a primary analysis tool for measurements from current, upcoming and proposed spacecraft missions that are focused on the kinetic microphysics of weakly collisional heliospheric plasmas, including the Magnetospheric Multiscale (MMS), Solar Probe Plus, Solar Orbiter and Turbulence Heating ObserveR (THOR) missions.

  12. Analysis of retarding field energy analyzer transmission by simulation of ion trajectories

    Science.gov (United States)

    van de Ven, T. H. M.; de Meijere, C. A.; van der Horst, R. M.; van Kampen, M.; Banine, V. Y.; Beckers, J.

    2018-04-01

    Retarding field energy analyzers (RFEAs) are used routinely for the measurement of ion energy distribution functions. By contrast, their ability to measure ion flux densities has been considered unreliable because of lack of knowledge about the effective transmission of the RFEA grids. In this work, we simulate the ion trajectories through a three-gridded RFEA using the simulation software SIMION. Using idealized test cases, it is shown that at high ion energy (i.e., >100 eV) the transmission is equal to the optical transmission rather than the product of the individual grid transparencies. Below 20 eV, ion trajectories are strongly influenced by the electric fields in between the grids. In this region, grid alignment and ion focusing effects contribute to fluctuations in transmission with ion energy. Subsequently the model has been used to simulate the transmission and energy resolution of an experimental RFEA probe. Grid misalignments reduce the transmission fluctuations at low energy. The model predicts the minimum energy resolution, which has been confirmed experimentally by irradiating the probe with a beam of ions with a small energy bandwidth.

  13. Development and Validation of an Enhanced Coupled-Field Model for PZT Cantilever Bimorph Energy Harvester

    Directory of Open Access Journals (Sweden)

    Long Zhang

    2013-01-01

    Full Text Available The power source with the limited life span has motivated the development of the energy harvesters that can scavenge the ambient environment energy and convert it into the electrical energy. With the coupled field characteristics of structure to electricity, piezoelectric energy harvesters are under consideration as a means of converting the mechanical energy to the electrical energy, with the goal of realizing completely self-powered sensor systems. In this paper, two previous models in the literatures for predicting the open-circuit and close-circuit voltages of a piezoelectric cantilever bimorph (PCB energy harvester are first described, that is, the mechanical equivalent spring mass-damper model and the electrical equivalent circuit model. Then, the development of an enhanced coupled field model for the PCB energy harvester based on another previous model in the literature using a conservation of energy method is presented. Further, the laboratory experiments are carried out to evaluate the enhanced coupled field model and the other two previous models in the literatures. The comparison results show that the enhanced coupled field model can better predict the open-circuit and close-circuit voltages of the PCB energy harvester with a proof mass bonded at the free end of the structure in order to increase the energy-harvesting level of the system.

  14. A shear-mode magnetoelectric heterostructure for harvesting external magnetic field energy

    Science.gov (United States)

    He, Wei; Zhang, Jitao; Lu, Yueran; Yang, Aichao; Qu, Chiwen; Yuan, Shuai

    2017-03-01

    In this paper, a magnetoelectric (ME) energy harvester is presented for scavenging external magnetic field energy. The proposed heterostructure consists of a Terfenol-D plate, a piezoelectric PZT5H plate, a NdFeB magnet, and two concentrators. The external magnetic field is concentrated to the Terfenol-D plate and the PZT5H plate working in shear-mode, which can potentially increase the magnetoelectric response. Experiments have been performed to verify the feasibility of the harvester. Under the magnetic field of 0.6 Oe, the device produces a RMS voltage of 0.53 V at the resonant frequency of 32.6 kHz. The corresponding output power reaches 44.96 μW across a 3.1 kΩ matching resistor.

  15. Diffusion of cosmic rays at EeV energies in inhomogeneous extragalactic magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Rafael Alves; Sigl, Günter, E-mail: rafael.alves.batista@desy.de, E-mail: guenter.sigl@desy.de [II. Institut für Theoretische Physik, Universität Hamburg Luruper Chaussee 149, 22761, Hamburg (Germany)

    2014-11-01

    Ultra-high energy cosmic rays can propagate diffusively in cosmic magnetic fields. When their propagation time is comparable to the age of the universe, a suppression in the flux relative to the case in the absence of magnetic fields will occur. In this work we find an approximate parametrization for this suppression for energies below ∼ Z EeV using several magnetic field distributions obtained from cosmological simulations of the magnetized cosmic web. We assume that the magnetic fields have a Kolmogorov power spectrum with the field strengths distributed according to these simulations. We show that, if magnetic fields are coupled to the matter distribution, low field strengths will fill most of the volume, making the suppression milder compared to the case of a constant magnetic field with strength equal to the mean value of this distribution. We also derive upper limits for this suppression to occur for some models of extragalactic magnetic fields, as a function of the coherence length of these fields.

  16. Fermion field as inflaton, dark energy and dark matter

    International Nuclear Information System (INIS)

    Grams, Guilherme; Souza, Rudinei C de; Kremer, Gilberto M

    2014-01-01

    The search for constituents that can explain the periods of accelerating expansion of the Universe is a fundamental topic in cosmology. In this context, we investigate how fermionic fields minimally and non-minimally coupled with the gravitational field may be responsible for accelerated regimes during the evolution of the Universe. The forms of the potential and coupling of the model are determined through the technique of the Noether symmetry for two cases. The first case comprises a Universe filled only with the fermion field. Cosmological solutions are straightforwardly obtained for this case and an exponential inflation mediated by the fermion field is possible with a non-minimal coupling. The second case takes account of the contributions of radiation and baryonic matter in the presence of the fermion field. In this case the fermion field plays the role of dark energy and dark matter, and when a non-minimal coupling is allowed, it mediates a power-law inflation. (paper)

  17. Experimental Measurement of Wave Field Variations around Wave Energy Converter Arrays

    OpenAIRE

    O'Boyle, Louise; Elsäßer, Björn; Whittaker, Trevor

    2017-01-01

    Wave energy converters (WECs) inherently extract energy from incident waves. For wave energy to become a significant power provider in the future, large farms of WECs will be required. This scale of energy extraction will increase the potential for changes in the local wave field and coastal environment. Assessment of these effects is necessary to inform decisions on the layout of wave farms for optimum power output and minimum environmental impact, as well as on potential site selection. An ...

  18. High energy near- and far-field ptychographic tomography at the ESRF

    Science.gov (United States)

    da Silva, Julio C.; Haubrich, Jan; Requena, Guillermo; Hubert, Maxime; Pacureanu, Alexandra; Bloch, Leonid; Yang, Yang; Cloetens, Peter

    2017-09-01

    In high-resolution tomography, one needs high-resolved projections in order to reconstruct a high-quality 3D map of a sample. X-ray ptychography is a robust technique which can provide such high-resolution 2D projections taking advantage of coherent X-rays. This technique was used in the far-field regime for a fair amount of time, but it can now also be implemented in the near-field regime. In both regimes, the technique enables not only high-resolution imaging, but also high sensitivity to the electron density of the sample. The combination with tomography makes 3D imaging possible via ptychographic X-ray computed tomography (PXCT), which can provide a 3D map of the complex-valued refractive index of the sample. The extension of PXCT to X-ray energies above 15 keV is challenging, but it can allow the imaging of object opaque to lower energy. We present here the implementation and developments of high-energy near- and far-field PXCT at the ESRF.

  19. Individual energy use and feedback in an office setting: A field trial

    International Nuclear Information System (INIS)

    Murtagh, Niamh; Nati, Michele; Headley, William R.; Gatersleben, Birgitta; Gluhak, Alexander; Imran, Muhammad Ali; Uzzell, David

    2013-01-01

    Despite national plans to deploy smart meters in small and medium businesses in the UK, there is little knowledge of occupant energy use in offices. The objectives of the study were to investigate the effect of individual feedback on energy use at the workdesk, and to test the relationship between individual determinants, energy use and energy reduction. A field trial is presented, which monitored occupant energy use and provided individual feedback to 83 office workers in a university. The trial comprised pre- and post-intervention surveys, energy measurement and provision of feedback for 18 weeks post-baseline, and two participant focus groups. The main findings were: statistically significant energy reduction was found, but not for the entire measurement period; engagement with feedback diminished over time; no measured individual variables were related to energy reduction and only attitudes to energy conservation were related to energy use; an absence of motivation to undertake energy reduction actions was in evidence. The implications for energy use in offices are considered, including the need for motivations beyond energy reduction to be harnessed to realise the clear potential for reduced energy use at workdesks. -- Highlights: •First study on individual energy use and feedback in offices. •Field trial with 83 office workers, measuring plug load at desks over 18 weeks. •Feedback resulted in energy reduction although not consistently. •Sizeable minority did not engage with the feedback. •Lack of motivation to conserve energy evident in focus groups

  20. Energy Dissipation and Dynamics in Large Guide Field Turbulence Driven Reconnection at the Magnetopause

    Science.gov (United States)

    TenBarge, J. M.; Shay, M. A.; Sharma, P.; Juno, J.; Haggerty, C. C.; Drake, J. F.; Bhattacharjee, A.; Hakim, A.

    2017-12-01

    Turbulence and magnetic reconnection are the primary mechanisms responsible for the conversion of stored magnetic energy into particle energy in many space and astrophysical plasmas. The magnetospheric multiscale mission (MMS) has given us unprecedented access to high cadence particle and field data of turbulence and magnetic reconnection at earth's magnetopause. The observations include large guide field reconnection events generated within the turbulent magnetopause. Motivated by these observations, we present a study of large guide reconnection using the fully kinetic Eulerian Vlasov-Maxwell component of the Gkeyll simulation framework, and we also employ and compare with gyrokinetics to explore the asymptotically large guide field limit. In addition to studying the configuration space dynamics, we leverage the recently developed field-particle correlations to diagnose the dominant sources of dissipation and compare the results of the field-particle correlation to other energy dissipation measures.

  1. Effects of a power and photon energy of incident light on near-field etching properties

    Science.gov (United States)

    Yatsui, T.; Saito, H.; Nishioka, K.; Leuschel, B.; Soppera, O.; Nobusada, K.

    2017-12-01

    We developed a near-field etching technique for realizing an ultra-flat surfaces of various materials and structures. To elucidate the near-field etching properties, we have investigated the effects of power and the photon energy of the incident light. First, we established theoretically that an optical near-field with photon energy lower than the absorption edge of the molecules can induce molecular vibrations. We used nanodiamonds to study the power dependence of the near-field etching properties. From the topological changes of the nanodiamonds, we confirmed the linear-dependence of the etching volume with the incident power. Furthermore, we studied the photon energy dependence using TiO2 nanostriped structures, which revealed that a lower photon energy results in a lower etching rate.

  2. A sensitive search for dark energy through chameleon scalar fields using neutron interferometry

    International Nuclear Information System (INIS)

    Snow, W M; Li, K; Skavysh, V; Arif, M; Huber, M; Heacock, B; Young, A R; Pushin, D

    2015-01-01

    The physical origin of the dark energy, which is postulated to cause the accelerated expansion rate of the universe, is one of the major open questions of cosmology. A large subset of theories postulate the existence of a scalar field with a nonlinear coupling to matter chosen so that the effective range and/or strength of the field is greatly suppressed unless the source is placed in vacuum. We describe a measurement using neutron interferometry which can place a stringent upper bound on chameleon fields proposed as a solution to the problem of the origin of dark energy of the universe in the regime with a strongly-nolinear coupling term. In combination with other experiments searching for exotic short-range forces and laser-based measurements, slow neutron experiments are capable of eliminating this and many similar types of scalar-field-based dark energy models by laboratory experiments

  3. Field Assessment of Energy Audit Tools for Retrofit Programs

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, J.; Bohac, D.; Nelson, C.; Smith, I.

    2013-07-01

    This project focused on the use of home energy ratings as a tool to promote energy retrofits in existing homes. A home energy rating provides a quantitative appraisal of a home's asset performance, usually compared to a benchmark such as the average energy use of similar homes in the same region. Home rating systems can help motivate homeowners in several ways. Ratings can clearly communicate a home's achievable energy efficiency potential, provide a quantitative assessment of energy savings after retrofits are completed, and show homeowners how they rate compared to their neighbors, thus creating an incentive to conform to a social standard. An important consideration is how rating tools for the retrofit market will integrate with existing home energy service programs. For residential programs that target energy savings only, home visits should be focused on key efficiency measures for that home. In order to gain wide adoption, a rating tool must be easily integrated into the field process, demonstrate consistency and reasonable accuracy to earn the trust of home energy technicians, and have a low monetary cost and time hurdle for homeowners. Along with the Home Energy Score, this project also evaluated the energy modeling performance of SIMPLE and REM/Rate.

  4. Interacting viscous ghost tachyon, K-essence and dilaton scalar field models of dark energy

    International Nuclear Information System (INIS)

    Karami, K; Fahimi, K

    2013-01-01

    We study the correspondence between the interacting viscous ghost dark energy model with the tachyon, K-essence and dilaton scalar field models in the framework of Einstein gravity. We consider a spatially non-flat FRW universe filled with interacting viscous ghost dark energy and dark matter. We reconstruct both the dynamics and potential of these scalar field models according to the evolutionary behavior of the interacting viscous ghost dark energy model, which can describe the accelerated expansion of the universe. Our numerical results show that the interaction and viscosity have opposite effects on the evolutionary properties of the ghost scalar field models. (paper)

  5. Magnetic field effects on the quantum wire energy spectrum and Green's function

    International Nuclear Information System (INIS)

    Morgenstern Horing, Norman J.

    2010-01-01

    We analyze the energy spectrum and propagation of electrons in a quantum wire on a 2D host medium in a normal magnetic field, representing the wire by a 1D Dirac delta function potential which would support just a single subband state in the absence of the magnetic field. The associated Schroedinger Green's function for the quantum wire is derived in closed form in terms of known functions and the Landau quantized subband energy spectrum is examined.

  6. Coupled energy-drift and force-balance equations for high-field hot-carrier transport

    International Nuclear Information System (INIS)

    Huang, Danhong; Alsing, P.M.; Apostolova, T.; Cardimona, D.A.

    2005-01-01

    Coupled energy-drift and force-balance equations that contain a frictional force for the center-of-mass motion of electrons are derived for hot-electron transport under a strong dc electric field. The frictional force is found to be related to the net rate of phonon emission, which takes away the momentum of a phonon from an electron during each phonon-emission event. The net rate of phonon emission is determined by the Boltzmann scattering equation, which depends on the distribution of electrons interacting with phonons. The work done by the frictional force is included into the energy-drift equation for the electron-relative scattering motion and is found to increase the thermal energy of the electrons. The importance of the hot-electron effect in the energy-drift term under a strong dc field is demonstrated in reducing the field-dependent drift velocity and mobility. The Doppler shift in the energy conservation of scattering electrons interacting with impurities and phonons is found to lead to an anisotropic distribution of electrons in the momentum space along the field direction. The importance of this anisotropic distribution is demonstrated through a comparison with the isotropic energy-balance equation, from which we find that defining a state-independent electron temperature becomes impossible. To the leading order, the energy-drift equation is linearized with a distribution function by expanding it into a Fokker-Planck-type equation, along with the expansions of both the force-balance equation and the Boltzmann scattering equation for hot phonons

  7. Effect of magnetic field on the impurity binding energy of the excited ...

    Indian Academy of Sciences (India)

    Abstract. The effect of external magnetic field on the excited state energies in a spher- ical quantum dot was studied. The impurity energy and binding energy were calculated using the variational method within the effective mass approximation and finite barrier potential. The results showed that by increasing the magnetic ...

  8. Classroom HVAC: Improving ventilation and saving energy -- field study plan

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael G.; Faulkner, David; Hodgson, Alfred T.; Sullivan, Douglas P.

    2004-10-14

    The primary goals of this research effort are to develop, evaluate, and demonstrate a very practical HVAC system for classrooms that consistently provides classrooms (CRs) with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research is motivated by the public benefits of energy efficiency, evidence that many CRs are under-ventilated, and public concerns about indoor environmental quality in CRs. This document provides a summary of the detailed plans developed for the field study that will take place in 2005 to evaluate the energy and IAQ performance of a new classroom HVAC technology. The field study will include measurements of HVAC energy use, ventilation rates, and IEQ conditions in 10 classrooms with the new HVAC technology and in six control classrooms with a standard HVAC system. Energy use and many IEQ parameters will be monitored continuously, while other IEQ measurements will be will be performed seasonally. Continuously monitored data will be remotely accessed via a LonWorks network. Instrument calibration plans that vary with the type of instrumentation used are established. Statistical tests will be employed to compare energy use and IEQ conditions with the new and standard HVAC systems. Strengths of this study plan include the collection of real time data for a full school year, the use of high quality instrumentation, the incorporation of many quality control measures, and the extensive collaborations with industry that limit costs to the sponsors.

  9. The scientometric biography of a leading scientist working on the field of bio-energy

    Energy Technology Data Exchange (ETDEWEB)

    Konur, Ozcan [Sirnak University Faculty of Engineering, Department of Mechanical Engineering (Turkey)], email: okonur@hotmail.com

    2011-07-01

    This paper presents a scientometric biography of a Turkish scientist, Prof. Dr. Ayhan Demirbas, who is a leading figure in the field of bio-energy. It describes the method and importance of doing such biographies and suggests that there are too few of them, this one being the first in this specific area. It provides insight into the individual, his work, his research and links in his field of studies and research. Prof. Dr. Demirbas has spent almost three decades in research, particularly in the field of bio-energy. He has researched and taught in the field of renewable energies including biodiesels, biofuels, biomass pyrolysis, liquefaction and gasification, biogas, bioalcohols, and biohydrogen. He has also studied a great variety of subjects, such as the development of pulp from plants, chemical and engineering thermodynamics, chemical and energy education, global climate change, drinking water and cereal analyses. He has published 454 articles as of 2011.

  10. The renewable energy field is gaining power

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, D.B.

    1984-01-01

    For about 25 years, Basic Resources Corp. in New York has been growing on the strength of operations ranging from oil and gas exploration and printing to computer leasing and the manufacture of highway toll-collecting equipment. But since early 1982, when it received an Energy Department grant, a new subsidiary has been working on a project with scant resemblance to any other of the multimillion-dollar firm's operations: the preliminary research for an ocean thermal energy plant that would convert heat on the ocean's surface to power at a site in the Hawaiian islands. Renewable energy -- once largely the domain of dreamers and urban dropouts -- has moved into the corporate mainstream, and more and more companies in the United States and abroad are trying to stake a claim to a piece of its future. Basic Resources is not the only renewable energy source firm doing well. Several hundred exhibitors and other participants -- including a number of foreign visitors -- turned out for the 3-day event. Arco, which has been working on photovoltaics since the late 1970s, is considered the world's largest manufacturer of photovoltaics -- solar cells that convert the sun's energy directly into electricity. But, despite tax credits, worldwide sales and dramatic strides in reducing the cost of the technology, the operation still isn't profitable after the costs of research and other costreduction efforts are included. Nonetheless, Arco has no plans to abandon the field, and its attitude explains why so many firms are bucking the odds and pursuing renewable energy.

  11. The state equation of Yang-Mills field dark energy models

    International Nuclear Information System (INIS)

    Zhao Wen; Zhang Yang

    2006-01-01

    In this paper, we study the possibility of building Yang-Mills (YM) field dark energy models with equation of state (EoS) crossing -1, and find that it cannot be realized by the single YM field models, no matter what kind of Lagrangian or initial condition. But the states of -1 -1 to <-1, and it will go to the critical state of ω = -1 with the expansion of the universe, which character is the same as the single YM field models, and the big rip is naturally avoided

  12. Accurate magnetic field calculations for contactless energy transfer coils

    NARCIS (Netherlands)

    Sonntag, C.L.W.; Spree, M.; Lomonova, E.A.; Duarte, J.L.; Vandenput, A.J.A.

    2007-01-01

    In this paper, a method for estimating the magnetic field intensity from hexagon spiral windings commonly found in contactless energy transfer applications is presented. The hexagonal structures are modeled in a magneto-static environment using Biot-Savart current stick vectors. The accuracy of the

  13. Free energy simulations with the AMOEBA polarizable force field and metadynamics on GPU platform.

    Science.gov (United States)

    Peng, Xiangda; Zhang, Yuebin; Chu, Huiying; Li, Guohui

    2016-03-05

    The free energy calculation library PLUMED has been incorporated into the OpenMM simulation toolkit, with the purpose to perform enhanced sampling MD simulations using the AMOEBA polarizable force field on GPU platform. Two examples, (I) the free energy profile of water pair separation (II) alanine dipeptide dihedral angle free energy surface in explicit solvent, are provided here to demonstrate the accuracy and efficiency of our implementation. The converged free energy profiles could be obtained within an affordable MD simulation time when the AMOEBA polarizable force field is employed. Moreover, the free energy surfaces estimated using the AMOEBA polarizable force field are in agreement with those calculated from experimental data and ab initio methods. Hence, the implementation in this work is reliable and would be utilized to study more complicated biological phenomena in both an accurate and efficient way. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  14. Symmetric Double Quantum Dot Energy States in a High Magnetic Field

    International Nuclear Information System (INIS)

    Morgenstern Horing, Norman J; Sawamura, Makoto

    2011-01-01

    The dynamical Green's function and energy spectrum of a 2D symmetric quantum double-dot system on a planar host in a normal magnetic field are analyzed here, representing the two dots by Dirac delta function potentials. The proliferation of energy levels due to Landau quantization is examined in detail.

  15. Development of a TPC for energy and fluence references in low energies neutronic fields (from 8 keV to 5 MeV)

    International Nuclear Information System (INIS)

    Maire, Donovan

    2015-01-01

    In order to judge the measurement reliability, metrology requires to measure quantities with their uncertainties, in relation to a reference through a documented and unbroken chain of calibrations. In neutron radiation field, instrument response has to be known as a function of the neutron energy. Then detector calibrations are required using reference neutron fields. In France, primary reference neutron fields are held by the LNE-IRSN, at the Laboratory for Neutron Metrology and Dosimetry (LMDN). In order to improve reference neutron field characterization, the LNE-IRSN MIMAC μTPC has been developed. This detector is a Time Projection Chamber (TPC), using a gas at low pressure (30 mbar abs. to 1 bar abs.). Nuclear recoils are generated by neutron elastic scattering onto gas atoms. By measuring the nuclear recoil energy and scattering angle, the μTPC detector is able to measure the energy distribution of the neutron fluence between 8 keV and 5 MeV. The main challenge was to perform accurate spectrometry of neutron fields in the keV range, following a primary procedure. First of all, a metrological approach was followed in order to master every physical process taking part in the neutron detection. This approach led to develop the direct and inverse models, representing the detector response function and its inverse function respectively. Using this detailed characterization, the energy distribution of the neutron fluence has been measured for a continuous neutron field of 27 keV. The reconstructed energy is 28,2 ± 4,5 keV, the difference between μTPC integral fluence measurement and other measurement methods is less than 6%. The LNE-IRSN MIMAC μTPC system becomes the only one system able to measure simultaneously energy and fluence at energies lower than 100 keV, following a primary procedure. The project goal is then reached. These measurements at energies lower than 100 keV shows also a non-linearity between the ionization charge and the ion kinetic energy

  16. Mentoring - et bidrag til bedre samspil

    DEFF Research Database (Denmark)

    Pedersen, Kim

    2004-01-01

    Diskussion af mentoring som bidrag til at understøtte og styrke samspillet mellem efteruddannelse og arbejde. Artiklen inddrager erfaringer fra konkret forløb med mentoring og diskuterer forløbene i lyset af teorier om mentoring baseret på international litteratur. Artiklen udspringer af arbejde...

  17. Electromagnetic radiation from positive-energy bound electrons in the Coulomb field of a nucleus at rest in a strong uniform magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Arsenyev, S. A.; Koryagin, S. A., E-mail: koryagin@appl.sci-nnov.ru [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)

    2012-06-15

    A classical analysis is presented of the electromagnetic radiation emitted by positive-energy electrons performing bound motion in the Coulomb field of a nucleus at rest in a strong uniform magnetic field. Bounded trajectories exist and span a wide range of velocity directions near the nucleus (compared to free trajectories with similar energies) when the electron Larmor radius is smaller than the distance at which the electron-nucleus Coulomb interaction energy is equal to the mechanical energy of an electron. The required conditions occur in magnetic white dwarf photospheres and have been achieved in experiments on production of antihydrogen. Under these conditions, the radiant power per unit volume emitted by positive-energy bound electrons is much higher than the analogous characteristic of bremsstrahlung (in particular, in thermal equilibrium) at frequencies that are below the electron cyclotron frequency but higher than the inverse transit time through the interaction region in a close collision in the absence of a magnetic field. The quantum energy discreteness of positive-energy bound states restricts the radiation from an ensemble of bound electrons (e.g., in thermal equilibrium) to nonoverlapping spectral lines, while continuum radiative transfer is dominated by linearly polarized bremsstrahlung.

  18. Analysis of optical near-field energy transfer by stochastic model unifying architectural dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Naruse, Makoto, E-mail: naruse@nict.go.jp [Photonic Network Research Institute, National Institute of Information and Communications Technology, 4-2-1 Nukui-kita, Koganei, Tokyo 184-8795 (Japan); Nanophotonics Research Center, Graduate School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); Akahane, Kouichi; Yamamoto, Naokatsu [Photonic Network Research Institute, National Institute of Information and Communications Technology, 4-2-1 Nukui-kita, Koganei, Tokyo 184-8795 (Japan); Holmström, Petter [Laboratory of Photonics and Microwave Engineering, Royal Institute of Technology (KTH), SE-164 40 Kista (Sweden); Thylén, Lars [Laboratory of Photonics and Microwave Engineering, Royal Institute of Technology (KTH), SE-164 40 Kista (Sweden); Hewlett-Packard Laboratories, Palo Alto, California 94304 (United States); Huant, Serge [Institut Néel, CNRS and Université Joseph Fourier, 25 rue des Martyrs BP 166, 38042 Grenoble Cedex 9 (France); Ohtsu, Motoichi [Nanophotonics Research Center, Graduate School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Electrical Engineering and Information Systems, Graduate School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2014-04-21

    We theoretically and experimentally demonstrate energy transfer mediated by optical near-field interactions in a multi-layer InAs quantum dot (QD) structure composed of a single layer of larger dots and N layers of smaller ones. We construct a stochastic model in which optical near-field interactions that follow a Yukawa potential, QD size fluctuations, and temperature-dependent energy level broadening are unified, enabling us to examine device-architecture-dependent energy transfer efficiencies. The model results are consistent with the experiments. This study provides an insight into optical energy transfer involving inherent disorders in materials and paves the way to systematic design principles of nanophotonic devices that will allow optimized performance and the realization of designated functions.

  19. Analysis of optical near-field energy transfer by stochastic model unifying architectural dependencies

    International Nuclear Information System (INIS)

    Naruse, Makoto; Akahane, Kouichi; Yamamoto, Naokatsu; Holmström, Petter; Thylén, Lars; Huant, Serge; Ohtsu, Motoichi

    2014-01-01

    We theoretically and experimentally demonstrate energy transfer mediated by optical near-field interactions in a multi-layer InAs quantum dot (QD) structure composed of a single layer of larger dots and N layers of smaller ones. We construct a stochastic model in which optical near-field interactions that follow a Yukawa potential, QD size fluctuations, and temperature-dependent energy level broadening are unified, enabling us to examine device-architecture-dependent energy transfer efficiencies. The model results are consistent with the experiments. This study provides an insight into optical energy transfer involving inherent disorders in materials and paves the way to systematic design principles of nanophotonic devices that will allow optimized performance and the realization of designated functions

  20. Energy confinement in a high-current reversed field pinch

    International Nuclear Information System (INIS)

    An, Z.G.; Lee, G.S.; Diamond, P.H.

    1985-07-01

    The ion temperature gradient driven (eta/sub i/) mode is proposed as a candidate for the cause of anomalous transport in high current reversed field pinches. A 'four-field' fluid model is derived to describe the coupled nonlinear evolution of resistive interchange and eta/sub i/ modes. A renormalized theory is discussed, and the saturation level of the fluctuations is analytically estimated. Transport scalings are obtained, and their implications discussed. In particular, these results indicate that pellet injection is a potentially viable mechanism for improving energy confinement in a high temperature RFP

  1. Health physics manpower in the atomic energy field, 1968-2000

    International Nuclear Information System (INIS)

    Baker, J.G.

    1978-01-01

    The structure of employment, historical trends and projections, of health physics workers in the atomic energy field is examined using U.S. Bureau of Labor Statistics survey data. During the 1968 to 1975 period atomic energy field employment has grown at a rate of 4.6% annually, compared to a rate of 1.8% for the U.S. economy. The majority of the growth has been concentrated in the private sector, while government-owned contractor-operated employment declined from 1968 through 1973. Data indicated that growth in the private sector is strongly correlated to growth in nuclear megawatt capacity. The recent revisions in projected generation capacity have depressed considerably the growth in future health physics worker demand. Using the most recent estimates of future capacity, health physics professional requirements in the field are expected to grow at a rate of 7.0% and technician requirements at a rate of 7.4% annually for the period 1975-1985. These results compare favourably with other published studies, all of which project faster growth for technicians than for professionals. (author)

  2. Low-energy electron-helium scattering in a Nd–YAG laser field

    International Nuclear Information System (INIS)

    Ajana, I.; Makhoute, A.; Khalil, D.

    2014-01-01

    Highlights: • Laser assisted electron helium excitation is studied at low incident energies. • The inclusion of the second-order Born contributions is significant at low incident energies. • The target distortion induced by the laser field should be taken into account. • The effect of the second term of the Born series is reduced as the energy increases. - Abstract: We study the electron-impact excitation of atomic helium, in the presence of a linearly polarized Nd–YAG laser field, accompanied by the transfer of ℓ photons, for low collision energy of 25 eV and laser intensity of 5.3 × 10 11 W cm −2 . The second-order Born approximation has been used to calculate the differential cross sections. Detailed calculations of the scattering amplitudes are performed by using the Sturmian basis expansion. A detailed analysis is made of the excitation of the 1 1 S → 2 1 S and 1 1 S → 2 1 P transitions. We discuss the behavior and the variation of the cross sections corresponding to the excitation process for various geometrical configurations

  3. Governmental interventions in the energy market. Study of the Dutch level playing field for fossil fuels, renewable sources, nuclear energy and energy conservation

    International Nuclear Information System (INIS)

    De Visser, E.; Winkel, T.; De Jager, D.; De Vos, R.; Blom, M.; Afman, M.

    2011-06-01

    This study has made an inventory of 53 governmental interventions in the Dutch energy market. Moreover, the consequences for the playing field for fossil fuels, renewable sources, nuclear energy and energy saving have been quantified. It shows that the government still stimulates the use of energy and fossil fuels more than it stimulates use of renewable energy sources. Policy that focuses on decreasing the price differences between sustainable and fossil should therefore focus on the phase-out of this support and subsequently on bridging the remaining financial gap. [nl

  4. Raman af hvide pigmenter

    DEFF Research Database (Denmark)

    Reeler, Nini Elisabeth Abildgaard; Nielsen, Ole Faurskov; Sauer, Stephan P. A.

    2013-01-01

    Et samspil mellem kunst og kemi. I et samarbejde mellem Statens Museum for Kunst og Kemisk Institut på KU er Ramanspek-troskopi brugt til at definere sammensætningen af blandinger af blyhvidt og calcit i maleriers hvide pigmenter....

  5. Politeness in written business discourse: A textlinguistic perspective on requests

    DEFF Research Database (Denmark)

    Pilegaard, Morten

    1997-01-01

    konkluderer, at der er et kompliceret kontekst- og rollestyret samspil mellem negative og positive verbale høflighedsstrategier. Artiklens teoretiske nyhedsværdi ligger i ekspliciteringen af sammenhængen mellem ekstra-, og intra- og intertekstuelle elementer og operationaliseringen af Brown...

  6. French know-how in the field of renewable energies

    International Nuclear Information System (INIS)

    2012-02-01

    Renewable energies are currently undergoing an unprecedented boom worldwide. They allow for the recovery of local energy sources as a sustainable response to numerous electricity, heating and transportation needs. In France, public and private stakeholders are striving to ensure that renewable energy accounts for 23% of final energy consumption by 2020. For over 20 years, the French Environment and Energy Management Agency (Agence de l'Environnement et de la Maitrise de l'energie - ADEME) has been promoting the development of these energy sources in addition to implementing energy efficiency improvement policies. In the framework of the Grenelle environmental round table, the agency assumes since 2009 responsibility for the implementation of a vast 'Renewable Heat Fund' (Fonds chaleur renouvelable), which in nearly three years, has led to the establishment of over 1,600 heat production plants using biomass, solar, geothermal energy, etc. To promote the marketing of advanced technologies, the ADEME is also in charge of a major support programme for demonstration projects: 'Investments for the future' (Investissements d'Avenir), which puts the emphasis on renewable and carbon-free energy. At the heart of these schemes, French companies are providing efficient products and services for national and international markets. Through this brochure, the Ademe presents the French expertise in the field of renewable energy, which combines innovation and industrial development to address the energy and climate challenges

  7. Energy flux determines magnetic field strength of planets and stars.

    Science.gov (United States)

    Christensen, Ulrich R; Holzwarth, Volkmar; Reiners, Ansgar

    2009-01-08

    The magnetic fields of Earth and Jupiter, along with those of rapidly rotating, low-mass stars, are generated by convection-driven dynamos that may operate similarly (the slowly rotating Sun generates its field through a different dynamo mechanism). The field strengths of planets and stars vary over three orders of magnitude, but the critical factor causing that variation has hitherto been unclear. Here we report an extension of a scaling law derived from geodynamo models to rapidly rotating stars that have strong density stratification. The unifying principle in the scaling law is that the energy flux available for generating the magnetic field sets the field strength. Our scaling law fits the observed field strengths of Earth, Jupiter, young contracting stars and rapidly rotating low-mass stars, despite vast differences in the physical conditions of the objects. We predict that the field strengths of rapidly rotating brown dwarfs and massive extrasolar planets are high enough to make them observable.

  8. Estimating decades-long trends in petroleum field energy return on investment (EROI) with an engineering-based model

    Science.gov (United States)

    Tripathi, Vinay S.

    2017-01-01

    This paper estimates changes in the energy return on investment (EROI) for five large petroleum fields over time using the Oil Production Greenhouse Gas Emissions Estimator (OPGEE). The modeled fields include Cantarell (Mexico), Forties (U.K.), Midway-Sunset (U.S.), Prudhoe Bay (U.S.), and Wilmington (U.S.). Data on field properties and production/processing parameters were obtained from a combination of government and technical literature sources. Key areas of uncertainty include details of the oil and gas surface processing schemes. We aim to explore how long-term trends in depletion at major petroleum fields change the effective energetic productivity of petroleum extraction. Four EROI ratios are estimated for each field as follows: The net energy ratio (NER) and external energy ratio (EER) are calculated, each using two measures of energy outputs, (1) oil-only and (2) all energy outputs. In all cases, engineering estimates of inputs are used rather than expenditure-based estimates (including off-site indirect energy use and embodied energy). All fields display significant declines in NER over the modeling period driven by a combination of (1) reduced petroleum production and (2) increased energy expenditures on recovery methods such as the injection of water, steam, or gas. The fields studied had NER reductions ranging from 46% to 88% over the modeling periods (accounting for all energy outputs). The reasons for declines in EROI differ by field. Midway-Sunset experienced a 5-fold increase in steam injected per barrel of oil produced. In contrast, Prudhoe Bay has experienced nearly a 30-fold increase in amount of gas processed and reinjected per unit of oil produced. In contrast, EER estimates are subject to greater variability and uncertainty due to the relatively small magnitude of external energy investments in most cases. PMID:28178318

  9. Estimating decades-long trends in petroleum field energy return on investment (EROI) with an engineering-based model.

    Science.gov (United States)

    Tripathi, Vinay S; Brandt, Adam R

    2017-01-01

    This paper estimates changes in the energy return on investment (EROI) for five large petroleum fields over time using the Oil Production Greenhouse Gas Emissions Estimator (OPGEE). The modeled fields include Cantarell (Mexico), Forties (U.K.), Midway-Sunset (U.S.), Prudhoe Bay (U.S.), and Wilmington (U.S.). Data on field properties and production/processing parameters were obtained from a combination of government and technical literature sources. Key areas of uncertainty include details of the oil and gas surface processing schemes. We aim to explore how long-term trends in depletion at major petroleum fields change the effective energetic productivity of petroleum extraction. Four EROI ratios are estimated for each field as follows: The net energy ratio (NER) and external energy ratio (EER) are calculated, each using two measures of energy outputs, (1) oil-only and (2) all energy outputs. In all cases, engineering estimates of inputs are used rather than expenditure-based estimates (including off-site indirect energy use and embodied energy). All fields display significant declines in NER over the modeling period driven by a combination of (1) reduced petroleum production and (2) increased energy expenditures on recovery methods such as the injection of water, steam, or gas. The fields studied had NER reductions ranging from 46% to 88% over the modeling periods (accounting for all energy outputs). The reasons for declines in EROI differ by field. Midway-Sunset experienced a 5-fold increase in steam injected per barrel of oil produced. In contrast, Prudhoe Bay has experienced nearly a 30-fold increase in amount of gas processed and reinjected per unit of oil produced. In contrast, EER estimates are subject to greater variability and uncertainty due to the relatively small magnitude of external energy investments in most cases.

  10. Estimating decades-long trends in petroleum field energy return on investment (EROI with an engineering-based model.

    Directory of Open Access Journals (Sweden)

    Vinay S Tripathi

    Full Text Available This paper estimates changes in the energy return on investment (EROI for five large petroleum fields over time using the Oil Production Greenhouse Gas Emissions Estimator (OPGEE. The modeled fields include Cantarell (Mexico, Forties (U.K., Midway-Sunset (U.S., Prudhoe Bay (U.S., and Wilmington (U.S.. Data on field properties and production/processing parameters were obtained from a combination of government and technical literature sources. Key areas of uncertainty include details of the oil and gas surface processing schemes. We aim to explore how long-term trends in depletion at major petroleum fields change the effective energetic productivity of petroleum extraction. Four EROI ratios are estimated for each field as follows: The net energy ratio (NER and external energy ratio (EER are calculated, each using two measures of energy outputs, (1 oil-only and (2 all energy outputs. In all cases, engineering estimates of inputs are used rather than expenditure-based estimates (including off-site indirect energy use and embodied energy. All fields display significant declines in NER over the modeling period driven by a combination of (1 reduced petroleum production and (2 increased energy expenditures on recovery methods such as the injection of water, steam, or gas. The fields studied had NER reductions ranging from 46% to 88% over the modeling periods (accounting for all energy outputs. The reasons for declines in EROI differ by field. Midway-Sunset experienced a 5-fold increase in steam injected per barrel of oil produced. In contrast, Prudhoe Bay has experienced nearly a 30-fold increase in amount of gas processed and reinjected per unit of oil produced. In contrast, EER estimates are subject to greater variability and uncertainty due to the relatively small magnitude of external energy investments in most cases.

  11. Adaptive acoustic energy delivery to near and far fields using foldable, tessellated star transducers

    Science.gov (United States)

    Zou, Chengzhe; Harne, Ryan L.

    2017-05-01

    Methods of guiding acoustic energy arbitrarily through space have long relied on digital controls to meet performance needs. Yet, more recent attention to adaptive structures with unique spatial configurations has motivated mechanical signal processing (MSP) concepts that may not be subjected to the same functional and performance limitations as digital acoustic beamforming counterparts. The periodicity of repeatable structural reconfiguration enabled by origami-inspired tessellated architectures turns attention to foldable platforms as frameworks for MSP development. This research harnesses principles of MSP to study a tessellated, star-shaped acoustic transducer constituent that provides on-demand control of acoustic energy guiding via folding-induced shape reconfiguration. An analytical framework is established to probe the roles of mechanical and acoustic geometry on the far field directivity and near field focusing of sound energy. Following validation by experiments and verification by simulations, parametric studies are undertaken to uncover relations between constituent topology and acoustic energy delivery to arbitrary points in the free field. The adaptations enabled by folding of the star-shaped transducer reveal capability for restricting sound energy to angular regions in the far field while also introducing means to modulate sound energy by three orders-of-magnitude to locations near to the transducer surface. In addition, the modeling philosophy devised here provides a valuable approach to solve general sound radiation problems for foldable, tessellated acoustic transducer constituents of arbitrary geometry.

  12. Microdosimetry of intermediate energy neutrons in fast neutron fields

    International Nuclear Information System (INIS)

    Saion, E.B.; Watt, D.E.

    1988-01-01

    A coaxial double cylindrical proportional counter has been constructed for microdosimetry of intermediate energy neutrons in mixed fields. Details are given of the measured gas gain and resolution characteristics of the counter for a wide range of anode voltages. Event spectra due to intermediate neutrons in any desired energy band is achieved by an appropriate choice of thickness of the common dividing wall in the counter and by appropriate use of the coincidence, anticoincidence pulse counting arrangements. Calculated estimates indicate that the dose contribution by fast neutrons to the energy deposition events in the intermediate neutron range may be as large as 25%. Empirical procedures being investigated aim to determine the necessary corrections to be applied to the microdose distributions, with a precision of 10%. (author)

  13. Practicability and margin for substitution processes in the energy field

    International Nuclear Information System (INIS)

    Mandel, H.

    1975-01-01

    In the past 25 years substitution processes have led to the result that energy supply of the Federal Republic of Germany is now dependent on mineral oil by more than 50 per cent. The development of prices on the mineral oil market during the last two years gave important impulses to innovations in the energy field. Already today a number of dispositions for substitution processes can be recognized which may, in conjunction with efforts for an increased rational use of the various energy carries, reduce the mineral oil share on primary energy requirements to one fourth up to year 2000. It has to be secured, that our economic system will get under control the research and development efforts which are required to gain the - at least part-wise - very exacting technologies for the use of substitution energy. The reduction of onesided dependence on mineral oil of our energy supply system is one of the most important aims in future energy politics. (orig.) [de

  14. Controlling the exciton energy of a nanowire quantum dot by strain fields

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yan; Zhang, Jiaxiang; Ding, Fei, E-mail: f.ding@ifw-dresden.de [Institute for Integrative Nanosciences, IFW Dresden, Helmholtz Strasse 20, 01069 Dresden (Germany); Zadeh, Iman Esmaeil; Jöns, Klaus D.; Fognini, Andreas; Zwiller, Val [Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft (Netherlands); Reimer, Michael E. [Institute for Quantum Computing and Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, N2L 3G1 (Canada); Dalacu, Dan; Poole, Philip J. [National Research Council, Ottawa, Ontario K1A 0R6 (Canada); Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtz Strasse 20, 01069 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, Reichenhainer Strasse 70, 09107 Chemnitz (Germany)

    2016-05-02

    We present an experimental route to engineer the exciton energies of single quantum dots in nanowires. By integrating the nanowires onto a piezoelectric crystal, we controllably apply strain fields to the nanowire quantum dots. Consequently, the exciton energy of a single quantum dot in the nanowire is shifted by several meVs without degrading its optical intensity and single-photon purity. Second-order autocorrelation measurements are performed at different strain fields on the same nanowire quantum dot. The suppressed multi-photon events at zero time delay clearly verify that the quantum nature of single-photon emission is well preserved under external strain fields. The work presented here could facilitate on-chip optical quantum information processing with the nanowire based single photon emitters.

  15. LET spectrometry with track etch detectors-Use in high-energy radiation fields

    International Nuclear Information System (INIS)

    Jadrnickova, I.; Spurny, F.

    2008-01-01

    For assessing the risk from ionizing radiation it is necessary to know not only the absorbed dose but also the quality of the radiation; radiation quality is connected with the physical quantity linear energy transfer (LET). One of the methods of determination of LET is based on chemically etched track detectors. This contribution concerns with a spectrometer of LET based on the track detectors and discusses some results obtained at: ·high-energy radiation reference field created at the SPS accelerator at CERN; and ·onboard of International Space Station where track-etch based LET spectrometer has been exposed 273 days during 'Matrjoshka - R' experiment. Results obtained are compared with the results of studies at some lower-energy neutron sources; some conclusions on the registrability of neutrons and the ability of this spectrometer to determine dose equivalent in high-energy radiation fields are formulated

  16. Radiation Fields in High Energy Accelerators and their impact on Single Event Effects

    CERN Document Server

    García Alía, Rubén; Wrobel, Frédéric; Brugger, Markus

    Including calculation models and measurements for a variety of electronic components and their concerned radiation environments, this thesis describes the complex radiation field present in the surrounding of a high-energy hadron accelerator and assesses the risks related to it in terms of Single Event Effects (SEE). It is shown that this poses not only a serious threat to the respective operation of modern accelerators but also highlights the impact on other high-energy radiation environments such as those for ground and avionics applications. Different LHC-like radiation environments are described in terms of their hadron composition and energy spectra. They are compared with other environments relevant for electronic component operation such as the ground-level, avionics or proton belt. The main characteristic of the high-energy accelerator radiation field is its mixed nature, both in terms of hadron types and energy interval. The threat to electronics ranges from neutrons of thermal energies to GeV hadron...

  17. Conservation laws and stress-energy-momentum tensors for systems with background fields

    Energy Technology Data Exchange (ETDEWEB)

    Gratus, Jonathan, E-mail: j.gratus@lancaster.ac.uk [Lancaster University, Lancaster LA1 4YB (United Kingdom); The Cockcroft Institute, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Obukhov, Yuri N., E-mail: yo@thp.uni-koeln.de [Institute for Theoretical Physics, University of Cologne, 50923 Koeln (Germany); Tucker, Robin W., E-mail: r.tucker@lancaster.ac.uk [Lancaster University, Lancaster LA1 4YB (United Kingdom); The Cockcroft Institute, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom)

    2012-10-15

    This article attempts to delineate the roles played by non-dynamical background structures and Killing symmetries in the construction of stress-energy-momentum tensors generated from a diffeomorphism invariant action density. An intrinsic coordinate independent approach puts into perspective a number of spurious arguments that have historically lead to the main contenders, viz the Belinfante-Rosenfeld stress-energy-momentum tensor derived from a Noether current and the Einstein-Hilbert stress-energy-momentum tensor derived in the context of Einstein's theory of general relativity. Emphasis is placed on the role played by non-dynamical background (phenomenological) structures that discriminate between properties of these tensors particularly in the context of electrodynamics in media. These tensors are used to construct conservation laws in the presence of Killing Lie-symmetric background fields. - Highlights: Black-Right-Pointing-Pointer The role of background fields in diffeomorphism invariant actions is demonstrated. Black-Right-Pointing-Pointer Interrelations between different stress-energy-momentum tensors are emphasised. Black-Right-Pointing-Pointer The Abraham and Minkowski electromagnetic tensors are discussed in this context. Black-Right-Pointing-Pointer Conservation laws in the presence of nondynamic background fields are formulated. Black-Right-Pointing-Pointer The discussion is facilitated by the development of a new variational calculus.

  18. Simulation mechanisms of low energy nuclear reaction using super flow energy external fields

    International Nuclear Information System (INIS)

    Gareev, F.A.; Zhidkova, I.E.; ); Ratis, Yu.I.

    2005-01-01

    Full text: The review of possible stimulation mechanisms of the LENR (low energy nuclear reactions) is represented. We have concluded that transamination of nuclei at low energies and excess heat are possible in the framework of the modern physical theory - the universal resonance synchronization principle and based on its different enhancement mechanisms of reaction rates are responsible for these processes. The excitation nd ionization of atom may play role as trigger for LERN. Investigation of this phenomenon requires knowledge of different branches if science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics. The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor re-productivity of experimental data in due ti the fact LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical re-productivity principle should be reconsidered for LENR experiments. Poor re-productivity and unexpected results do not means that the experiment is wrong. Our main conclusion: LENR may be understand in terms of the modern theory without any violation of the basic physics. 2) Weak and electromagnetic interactions may show the strong influence of the surrounding conditions on the nuclear processes. 3) Universal resonance synchronization principle is a key issue to make a bridge between various scales of interactions and it is responsible for self-organization of hierarchical systems independent of substances, fields and interactions. We bring some arguments in favor of the mechanism - order based on order - declared by Schroedinger in fundamental problem of contemporary science. 4) The universal resonance synchronization principle became a fruitful interdisciplinary science of general laws of self-organized processes in different branches of physics because it is consequence of the energy conservation law and resonance

  19. Low Energy Technology. A Unit of Instruction on Energy Conservation in Field Crop Production.

    Science.gov (United States)

    Davis, George; Scanlon, Dennis C.

    This unit of instruction on energy conservation in field crop production was designed for use by agribusiness and natural resources teachers in Florida high schools and by agricultural extension agents as they work with adults and students. It is one of a series of 11 instructional units (see note) written to help teachers and agents to educate…

  20. Momentum-energy of the non-radiating electromagnetic field: open problems?

    International Nuclear Information System (INIS)

    Kholmetskii, Alexander L

    2006-01-01

    This paper inspects more closely the problem of the momentum and energy of a bound (non-radiative) electromagnetic (EM) field. It has been shown that for an isolating system of non-radiative non-relativistic mechanically free charged particles, a transformation of mechanical to EM momentum and vice versa occurs in accordance with the requirement P-vector G =const, where P-vector G = P-vector M + Σ i N q i A-vector i is the canonical momentum (N>1 is the number of particles, q is the charge, A-vector is the vector potential, P-vector M is the mechanical momentum of the system). Then dP-vector M /dt = -(d/dt)Σq i A-vector i represents the self-force, acting on this isolating system due to violation of Newton's third law in EM interaction. This equation is not applicable to an isolated charged particle, and the problems of its self-action and its own EM momentum have been examined. Analysing the systems of non-radiative particles, where the retardation is not negligible ('dynamical' systems in our definition) it has been found that the total momentum is the same at the initial and final stationary states of such systems, but it varies with time during the dynamical processes. It means a violation of continuous conservation of the total momentum, if the bound EM field spreads at the light velocity c. Finally, the compatibility of the energy conservation law and the Lentz rule for retarded non-radiative EM field has been examined. It has been shown that for dynamical systems the energy conservation law comes into a certain contradiction with the finite (light) spread velocity for the bound EM field

  1. Research and Evaluation of the Energy Flux Density of the Mobile Phone Electromagnetic Field

    Directory of Open Access Journals (Sweden)

    Pranas Baltrėnas

    2012-12-01

    Full Text Available The article analyses variations in the energy flux density of the electromagnetic field of 10 mobile phones depending on distance. The studies have been conducted using three modes: sending a text message, receiving a text message and connecting a mobile phone to the Internet. When text messages are received or sent from a mobile phone, the values of the energy flux density of the mobile phone electromagnetic field exceed the safe allowable limit and make 10 μW / cm². A distance of 10, 20 and 30 cm from a mobile phone is effective protection against the energy flux density of the electromagnetic field when writing texts, receiving messages or connecting to the mobile Internet.Article in Lithuanian

  2. En problematisering af samspillet mellem centrale pædagogiske principper på arkitektuddannelsen

    DEFF Research Database (Denmark)

    Grønbæk, Niels; Hedegaard Møller, Camilla

    2013-01-01

    Ud fra John Deweys erfaringspædagogik, bygget op om begreberne erfaring, situation og samspil, undersøges aspekter af en strukturel adskillelse af målstyrede og projektbaserede undervisningspraksisser med arkitektuddannelsen på Kunstakademiets Skoler for Arkitektur Design og Konservering som...

  3. SBI-konference om byggeprogrammering, den 23.februar 1977

    DEFF Research Database (Denmark)

    Kolte, L.

    Arkitekt Lennart Kolte, Byggnadsstyrelsen, indleder med at berette om erfaringerne fra anvendelse af GP-Kontor 75. En revision af GP-Kontor og brugsanvisning er forestående. GP udfylder en vigtig funktion i bygherreorganisationen i samspil med brugere og projekterende. Materialets detaljeringsgrad...

  4. Field theory reformulated without self-energy parts: the dressing operator

    International Nuclear Information System (INIS)

    Haan, M. de

    2004-01-01

    The reformulation of field theory for avoiding self-energy parts in the dynamical evolution has been applied successfully in the framework of the Lee model [Ann. Phys. 311 (2004) 314], enabling a kinetic extension of the description. The basic ingredient is the recognition of these self-energy parts [Trends Stat. Phys. 3 (2000) 115]. The original reversible description is embedded in the new one and appears now as a restricted class of initial conditions [Progr. Theor. Phys. 109 (2003) 881]. This program is realized here in the reduced formalism for a scalar field, interacting with a two-level atom, beyond the usual rotating wave approximation. The kinetic evolution operator, previously surmised [Physica A 171 (1991) 159], is here derived from first principles, justifying the usual practice in optics where the common use of the so-called pole approximation [Atoms in Electromagnetic Fields, 1994, 119] should no longer be viewed as an approximation but as an alternative description in the appropriate formalism. That model illustrates how some dressing of the atomic levels (and vertices), through an appropriate operator, finds its place naturally into the new formalism since the bare and dressed ground states do no longer coincide. Moreover, finite velocity for field propagation is now possible in all cases, without the presence of precursors for multiple detections

  5. Energy levels and far-infrared optical absorption of impurity doped semiconductor nanorings: Intense laser and electric fields effects

    Energy Technology Data Exchange (ETDEWEB)

    Barseghyan, M.G., E-mail: mbarsegh@ysu.am

    2016-11-10

    Highlights: • The electron-impurity interaction on energy levels in nanoring have been investigated. • The electron-impurity interaction on far-infrared absorption have been investigated. • The energy levels are more stable for higher values of electric field. - Abstract: The effects of electron-impurity interaction on energy levels and far-infrared absorption in semiconductor nanoring under the action of intense laser and lateral electric fields have been investigated. Numerical calculations are performed using exact diagonalization technique. It is found that the electron-impurity interaction and external fields change the energy spectrum dramatically, and also have significant influence on the absorption spectrum. Strong dependence on laser field intensity and electric field of lowest energy levels, also supported by the Coulomb interaction with impurity, is clearly revealed.

  6. A study of build-up effects in high-energy radiation fields using a TEPC

    Energy Technology Data Exchange (ETDEWEB)

    Hoefert, M; Stevenson, G R [CERN, European Laboratory for Particle Physics, Geneva (Switzerland); Aroua, A [IAR, Institute for Applied Radiophysics, Lausanne (Switzerland); Sannikov, A V [IHEP, Institute for High-Energy Physics, Protvino (Russian Federation)

    1995-09-04

    A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

  7. A study of build-up effects in high-energy radiation fields using a TEPC

    International Nuclear Information System (INIS)

    Hoefert, M.; Stevenson, G.R.; Aroua, A.; Sannikov, A.V.

    1995-01-01

    A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

  8. Use of energy analysis to evaluate the parameters of wave fields

    Energy Technology Data Exchange (ETDEWEB)

    Soldatov, V.N.; Sinitsyn, Ye.S.

    1984-01-01

    Algorithms are proposed and studied for energy analysis of the wave fields. A comparative evaluation is made of the resolution of the energy analysis methods. A method is examined for automated processing of the energograms allowing a search for an estimate of the parameters with significant acceleration of the computer calculations and saving of its working storage by designing multipurpose algorithms of data processing.

  9. Using Field-Metered Data to Quantify Annual Energy Use of Portable Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Burke, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Willem, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Ni, Chun Chun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Stratton, Hannah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Chen, Yuting [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Ganeshalingam, Mohan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Iyer, Maithili [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Price, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division; Dunham, Camilla [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept., Environmental Energy Technologies Division

    2014-12-12

    As many regions of the United States experience rising temperatures, consumers have come to rely increasingly on cooling appliances (including portable air conditioners) to provide a comfortable indoor temperature. Home occupants sometimes use a portable air conditioner (PAC) to maintain a desired indoor temperature in a single room or enclosed space. Although PACs in residential use are few compared to centrally installed and room air conditioning (AC) units, the past few years have witnessed an increase of PACs use throughout the United States. There is, however, little information and few research projects focused on the energy consumption and performance of PACs, particularly studies that collect information from field applications of PACs. The operation and energy consumption of PACs may differ among geographic locations and households, because of variations in cooling load, frequency, duration of use, and other user-selected settings. In addition, the performance of building envelope (thermal mass and air leakage) as well as inter-zonal mixing within the building would substantially influence the ability to control and maintain desirable indoor thermal conditions. Lawrence Berkeley National Laboratory (LBNL) conducted an initial field-metering study aimed at increasing the knowledge and data related to PAC operation and energy consumption in the United States. LBNL performed its field-metering study from mid-April to late October 2014. The study, which monitored 19 sites in the Northeastern United States (4 in upstate New York and 15 near Philadelphia), collected real-time data on PAC energy consumption along with information regarding housing characteristics, consumer behavior, and environmental conditions that were expected to affect PAC performance. Given the limited number of test sites, this study was not intended to be statistically representative of PAC users in the United States but rather to understand the system response to the cooling demand and to

  10. Making energy visible: A qualitative field study of how householders interact with feedback from smart energy monitors

    International Nuclear Information System (INIS)

    Hargreaves, Tom; Nye, Michael; Burgess, Jacquelin

    2010-01-01

    This paper explores how UK householders interacted with feedback on their domestic energy consumption in a field trial of real-time displays or smart energy monitors. After examining relevant bodies of literature on the effects of energy feedback on consumption behaviour, and on the complex role of energy and appliances within household moral economies, the paper draws on qualitative evidence from interviews with 15 UK householders trialling smart energy monitors of differing levels of sophistication. It focuses specifically on householder motivations for acquiring the monitors, how the monitors have been used, how feedback has changed consumption behaviour, and the limitations to further behavioural change the householders experienced. The paper concludes by identifying significant implications for future research and policy in this area.

  11. Megagauss field generation for high-energy-density plasma science experiments

    International Nuclear Information System (INIS)

    Rovang, Dean Curtis; Struve, Kenneth William; Porter, John Larry Jr.

    2008-01-01

    There is a need to generate magnetic fields both above and below 1 megagauss (100 T) with compact generators for laser-plasma experiments in the Beamlet and Petawatt test chambers for focused research on fundamental properties of high energy density magnetic plasmas. Some of the important topics that could be addressed with such a capability are magnetic field diffusion, particle confinement, plasma instabilities, spectroscopic diagnostic development, material properties, flux compression, and alternate confinement schemes, all of which could directly support experiments on Z. This report summarizes a two-month study to develop preliminary designs of magnetic field generators for three design regimes. These are, (1) a design for a relatively low-field (10 to 50 T), compact generator for modest volumes (1 to 10 cm3), (2) a high-field (50 to 200 T) design for smaller volumes (10 to 100 mm3), and (3) an extreme field (greater than 600 T) design that uses flux compression. These designs rely on existing Sandia pulsed-power expertise and equipment, and address issues of magnetic field scaling with capacitor bank design and field inductance, vacuum interface, and trade-offs between inductance and coil designs

  12. Evolution of perturbations in distinct classes of canonical scalar field models of dark energy

    International Nuclear Information System (INIS)

    Jassal, H. K.

    2010-01-01

    Dark energy must cluster in order to be consistent with the equivalence principle. The background evolution can be effectively modeled by either a scalar field or by a barotropic fluid. The fluid model can be used to emulate perturbations in a scalar field model of dark energy, though this model breaks down at large scales. In this paper we study evolution of dark energy perturbations in canonical scalar field models: the classes of thawing and freezing models. The dark energy equation of state evolves differently in these classes. In freezing models, the equation of state deviates from that of a cosmological constant at early times. For thawing models, the dark energy equation of state remains near that of the cosmological constant at early times and begins to deviate from it only at late times. Since the dark energy equation of state evolves differently in these classes, the dark energy perturbations too evolve differently. In freezing models, since the equation of state deviates from that of a cosmological constant at early times, there is a significant difference in evolution of matter perturbations from those in the cosmological constant model. In comparison, matter perturbations in thawing models differ from the cosmological constant only at late times. This difference provides an additional handle to distinguish between these classes of models and this difference should manifest itself in the integrated Sachs-Wolfe effect.

  13. Technological change as social proces

    DEFF Research Database (Denmark)

    Jamison, Andrew

    2004-01-01

    The article distinguishes between different meanings that technology has as well as the different 'roles' that technologies play in society. udfoldes tre forståelser af teknologisk forandring. Der sigtes på at fremstille forskellige meningsdannelser, som i sit samspil konstituerer et samfunds opf...

  14. Brugerens arme og ben

    DEFF Research Database (Denmark)

    Munk-Madsen, Eva

    2006-01-01

    Omsorgsarbejde, det praktiske, sociale og emotionelle arbejde omsorgsarbejdere udfører i samspil med omsorgsmodtagere, har både diskursive og praktiske elementer. Disse er tæt forbundne via arbejdets mellemmenneskelige karakter. I denne artikel er det samspillet mellem diskurs og plejepraksis i h...

  15. Den intime computer

    DEFF Research Database (Denmark)

    Hansen, Lone Koefoed

    2008-01-01

    Artiklen undersøger, hvordan parløbet mellem virtualitet og materialitet italesættes i kunstartefakter, der tematiserer og problematiserer computerens og kroppens samspil. I takt med at de digitale teknologier smelter sammen med vores 'virkelige' verden, opløses modstillingen mellem det virtuelle...

  16. Klienters virkninger på sundhedsprofessionerne

    DEFF Research Database (Denmark)

    Larsen, Kristian; Højbjerg, Karin

    2014-01-01

    I professionslitteraturen beskrives profession overordnet som mere eller mindre autonome, faglige grupper, der i et historisk perspektiv udvikler sig i et samspil med samfundsmæssige institutioner samt i relationer til andre faggrupper Abbott 1988, Abbott 2005a og b, Carlhed 2011, Friedson, Weber...

  17. Buesenderen

    DEFF Research Database (Denmark)

    Buhl, Hans

    . Verdenskrig.   Bogen fortæller buesenderens forskellige udviklingshistorier i Danmark, Tyskland, England og USA. Den viser, at det, der driver og styrer udviklingen af store teknologiske systemer, ikke bare er den geniale opfindelse, men et komplekst samspil mellem geni, industri, politik, økonomi, teknologi...

  18. Redesigning existing transcranial magnetic stimulation coils to reduce energy: application to low field magnetic stimulation

    Science.gov (United States)

    Wang, Boshuo; Shen, Michael R.; Deng, Zhi-De; Smith, J. Evan; Tharayil, Joseph J.; Gurrey, Clement J.; Gomez, Luis J.; Peterchev, Angel V.

    2018-06-01

    Objective. To present a systematic framework and exemplar for the development of a compact and energy-efficient coil that replicates the electric field (E-field) distribution induced by an existing transcranial magnetic stimulation coil. Approach. The E-field generated by a conventional low field magnetic stimulation (LFMS) coil was measured for a spherical head model and simulated in both spherical and realistic head models. Then, using a spherical head model and spatial harmonic decomposition, a spherical-shaped cap coil was synthesized such that its windings conformed to a spherical surface and replicated the E-field on the cortical surface while requiring less energy. A prototype coil was built and electrically characterized. The effect of constraining the windings to the upper half of the head was also explored via an alternative coil design. Main results. The LFMS E-field distribution resembled that of a large double-cone coil, with a peak field strength around 350 mV m‑1 in the cortex. The E-field distributions of the cap coil designs were validated against the original coil, with mean errors of 1%–3%. The cap coil required as little as 2% of the original coil energy and was significantly smaller in size. Significance. The redesigned LFMS coil is substantially smaller and more energy-efficient than the original, improving cost, power consumption, and portability. These improvements could facilitate deployment of LFMS in the clinic and potentially at home. This coil redesign approach can also be applied to other magnetic stimulation paradigms. Finally, the anatomically-accurate E-field simulation of LFMS can be used to interpret clinical LFMS data.

  19. Energy momentum tensor and marginal deformations in open string field theory

    International Nuclear Information System (INIS)

    Sen, Ashoke

    2004-01-01

    Marginal boundary deformations in a two dimensional conformal field theory correspond to a family of classical solutions of the equations of motion of open string field theory. In this paper we develop a systematic method for relating the parameter labelling the marginal boundary deformation in the conformal field theory to the parameter labelling the classical solution in open string field theory. This is done by first constructing the energy-momentum tensor associated with the classical solution in open string field theory using Noether method, and then comparing this to the answer obtained in the conformal field theory by analysing the boundary state. We also use this method to demonstrate that in open string field theory the tachyon lump solution on a circle of radius larger than one has vanishing pressure along the circle direction, as is expected for a co-dimension one D-brane. (author)

  20. The Large Scale Structure of the Galactic Magnetic Field and High Energy Cosmic Ray Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Muniz, Jaime [Department de Fisica de PartIculas, University de Santiago de Compostela, 15782 Santiago, SPAIN (Spain); Stanev, Todor [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States)

    2006-10-15

    Measurements of the magnetic field in our Galaxy are complex and usually difficult to interpret. A spiral regular field in the disk is favored by observations, however the number of field reversals is still under debate. Measurements of the parity of the field across the Galactic plane are also very difficult due to the presence of the disk field itself. In this work we demonstrate that cosmic ray protons in the energy range 10{sup 18} to 10{sup 19}eV, if accelerated near the center of the Galaxy, are sensitive to the large scale structure of the Galactic Magnetic Field (GMF). In particular if the field is of even parity, and the spiral field is bi-symmetric (BSS), ultra high energy protons will predominantly come from the Southern Galactic hemisphere, and predominantly from the Northern Galactic hemisphere if the field is of even parity and axi-symmetric (ASS). There is no sensitivity to the BSS or ASS configurations if the field is of odd parity.

  1. The Development of International Law in the Field of Renewable Energy

    Directory of Open Access Journals (Sweden)

    Imam Mulyana

    2016-04-01

    Full Text Available Energy plays a pivotal role in ensuring economic growth, social equity and live-able environment. In this regard, the non-renewable or conventional source of energy such as oil, gas and coal continue to supply the energy demand throughout the world. Nevertheless, as the awareness of the international society towards the protection and preservation of the global environment is rapidly growing, the utilization of energy resources has been gradually shifted from the non-renewable to renewable ones. Observing the international developments in the field of energy, further international legal instruments is required to be able to regulate renewable energy activities undertaken by the countries today. Although there have been a number of rules in international law, but until recently, most of these regulations is still not legally binding. Moreover, to achieve world order that uses renewable energy, international law also had to resolve some fundamental issues, namely the issue of state sovereignty and energy security.

  2. Features of the galactic magnetic field regarding deflections of ultra-high-energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Wirtz, Marcus; Erdmann, Martin; Mueller, Gero; Urban, Martin [III. Physikalisches Institut A, RWTH Aachen University (Germany)

    2016-07-01

    Most recent models of the galactic magnetic field have been derived from Faraday rotation measurements and imply strong deflections even for ultra-high energy cosmic rays. We investigate the characteristics of the different field parametrizations and point out similarities and interesting features. Among them are extragalactic regions which are invisible for an Earth bound observation and the transition from diffuse to ballistic behaviour in the 1 EeV energy regime. Applying this knowledge to a directional analysis, there are indications for deflection patterns by the galactic magnetic field in cosmic ray arrival directions measured by the Pierre Auger Observatory.

  3. The influence of the energy distribution of workplace fields on neutron personal dosemeter reading

    International Nuclear Information System (INIS)

    Tanner, R.J.; Thomas, D.J.; Bartlett, D.T.; Hager, L.G.; Horwood, N.A.

    2002-01-01

    Variations in the energy dependence of response of neutron personal dosemeters cause systematic errors in the readings obtained in workplace fields. The magnitude of these errors has been determined theoretically by folding measured and calculated workplace energy distributions with dosemeter response functions, to determine the response of a given personal dosemeter in that field. These results have been analysed with consideration of the dosemeter response to various calibration spectra, and with reference to different workplaces. The dosemeters in the study are discussed in terms of the workplaces for which they can be suitably calibrated. Deficiencies in the published neutron energy distributions are identified

  4. Relativistic deformed mean-field calculation of binding energy differences of mirror nuclei

    International Nuclear Information System (INIS)

    Koepf, W.; Barreiro, L.A.

    1996-01-01

    Binding energy differences of mirror nuclei for A=15, 17, 27, 29, 31, 33, 39 and 41 are calculated in the framework of relativistic deformed mean-field theory. The spatial components of the vector meson fields and the photon are fully taken into account in a self-consistent manner. The calculated binding energy differences are systematically smaller than the experimental values and lend support to the existence of the Okamoto-Nolen-Schiffer anomaly found decades ago in nonrelativistic calculations. For the majority of the nuclei studied, however, the results are such that the anomaly is significantly smaller than the one obtained within state-of-the-art nonrelativistic calculations. (author). 35 refs

  5. Near-field effects and energy transfer in hybrid metal-oxide nanostructures.

    Science.gov (United States)

    Herr, Ulrich; Kuerbanjiang, Balati; Benel, Cahit; Papageorgiou, Giorgos; Goncalves, Manuel; Boneberg, Johannes; Leiderer, Paul; Ziemann, Paul; Marek, Peter; Hahn, Horst

    2013-01-01

    One of the big challenges of the 21st century is the utilization of nanotechnology for energy technology. Nanoscale structures may provide novel functionality, which has been demonstrated most convincingly by successful applications such as dye-sensitized solar cells introduced by M. Grätzel. Applications in energy technology are based on the transfer and conversion of energy. Following the example of photosynthesis, this requires a combination of light harvesting, transfer of energy to a reaction center, and conversion to other forms of energy by charge separation and transfer. This may be achieved by utilizing hybrid nanostructures, which combine metallic and nonmetallic components. Metallic nanostructures can interact strongly with light. Plasmonic excitations of such structures can cause local enhancement of the electrical field, which has been utilized in spectroscopy for many years. On the other hand, the excited states in metallic structures decay over very short lifetimes. Longer lifetimes of excited states occur in nonmetallic nanostructures, which makes them attractive for further energy transfer before recombination or relaxation sets in. Therefore, the combination of metallic nanostructures with nonmetallic materials is of great interest. We report investigations of hybrid nanostructured model systems that consist of a combination of metallic nanoantennas (fabricated by nanosphere lithography, NSL) and oxide nanoparticles. The oxide particles were doped with rare-earth (RE) ions, which show a large shift between absorption and emission wavelengths, allowing us to investigate the energy-transfer processes in detail. The main focus is on TiO2 nanoparticles doped with Eu(3+), since the material is interesting for applications such as the generation of hydrogen by photocatalytic splitting of water molecules. We use high-resolution techniques such as confocal fluorescence microscopy for the investigation of energy-transfer processes. The experiments are

  6. Minimum energy control for a two-compartment neuron to extracellular electric fields

    Science.gov (United States)

    Yi, Guo-Sheng; Wang, Jiang; Li, Hui-Yan; Wei, Xi-Le; Deng, Bin

    2016-11-01

    The energy optimization of extracellular electric field (EF) stimulus for a neuron is considered in this paper. We employ the optimal control theory to design a low energy EF input for a reduced two-compartment model. It works by driving the neuron to closely track a prescriptive spike train. A cost function is introduced to balance the contradictory objectives, i.e., tracking errors and EF stimulus energy. By using the calculus of variations, we transform the minimization of cost function to a six-dimensional two-point boundary value problem (BVP). Through solving the obtained BVP in the cases of three fundamental bifurcations, it is shown that the control method is able to provide an optimal EF stimulus of reduced energy for the neuron to effectively track a prescriptive spike train. Further, the feasibility of the adopted method is interpreted from the point of view of the biophysical basis of spike initiation. These investigations are conducive to designing stimulating dose for extracellular neural stimulation, which are also helpful to interpret the effects of extracellular field on neural activity.

  7. Holographic Bound in Quantum Field Energy Density and Cosmological Constant

    OpenAIRE

    Castorina, Paolo

    2012-01-01

    The cosmological constant problem is reanalyzed by imposing the limitation of the number of degrees of freedom (d.o.f.) due to entropy bounds directly in the calculation of the energy density of a field theory. It is shown that if a quantum field theory has to be consistent with gravity and holography, i.e. with an upper limit of storing information in a given area, the ultraviolet momentum cut-off is not the Planck mass, M_p, as naively expected, but M_p/N_U^(1/4) where N_U is the number of ...

  8. Self-generated magnetic fields and energy transport by ultra-intense laser-plasma interaction

    International Nuclear Information System (INIS)

    Abudurexiti, A.; Tuniyazi, P.; Wang Qian

    2011-01-01

    The electromagnetic instability (Weibel instability) and its mechanism in ultra-intense laser-plasma interactions are studied by using three-dimensional particle-in-cell simulations. The transport of energy in electron thermal conduction is analyzed by the Spitzer-Harm theory, and the election's vertical pyrogenation phenomenon that resulted from anisotropic heating of laser is observed. The results indicate that the strong magnetic field excited by Weibel instability makes the electron beam deposit its energy within a very short distance, and it restrains the electron thermal flux formed when the laser ponderomotive force bursts through the electron. With the increase of the self-generated magnetic field, the electron will be seized by the wave of magnetic field, and the transport of heat will be restricted. (authors)

  9. Shaping markets : A neoinstitutional analysis of the emerging organizational field of renewable energy in China

    Energy Technology Data Exchange (ETDEWEB)

    Hoeyrup Christensen, N.

    2013-02-01

    Today, China is the world leading investor in renewable energy. At the heart of this effort lies China's ability to shape markets through industrial policies. Through a neoinstitutional theoretical perspective this dissertation views China's efforts within renewable energy as the emergence of a new organizational field. Despite the importance of organizational fields as a key concept in the neoinstitutional literature, there is a lack of studies on exactly how they emerge. Throughout four articles this dissertation scrutinizes therefore the emergence of the field of renewable energy in China and the mechanisms driving this emergence. Firstly, the relation between state and market is examined, and it is argued that Chinese state interventions in markets, for instance through subsidies, are based in deeply rooted historic grounds. Thus, the article explains the general context in which the Party-state handles subsidized markets, like renewable energy. Secondly, the specific development of the idea of sustainable development, and how it evolves into an institutional logic of its own, is analysed. It is around this institutional logic that renewable energy emerges as a field. The key mechanism in play is the idea work of the Party state by which sustainable development is positioned in the Partystate discourse. Thirdly, subsidization of renewable energy in China is examined as an important feature of the increasing institutionalization of the organizational field. It is shown how negotiation between companies and Party-state is the vital mechanism by which subsidies are determined. Fourthly, it is analysed how the institutional entrepreneurship of one single company resulted in an official recognition of biomass power production as a source of renewable energy, and thereby an expansion of the organizational field. Again, the main mechanism was the company's idea work, through which a crucial link between biomass and sustainable development was

  10. Microelectrode for energy and current control of nanotip field electron emitters

    International Nuclear Information System (INIS)

    Lüneburg, S.; Müller, M.; Paarmann, A.; Ernstorfer, R.

    2013-01-01

    Emerging experiments and applications in electron microscopy, holography, and diffraction benefit from miniaturized electron guns for compact experimental setups. We present a highly compact microelectrode integrated field emitter that consists of a tungsten nanotip coated with a few micrometers thick polyimide film followed by a several nanometers thick gold film, both positioned behind the exposed emitter apex by approximately 10–30 μm. The control of the electric field strength at the nanometer scale tip apex allows suppression, extraction, and energy tuning of field-emitted electrons. The performance of the microelectrode is demonstrated experimentally and supported by numerical simulations

  11. Energy-momentum tensor for a Casimir apparatus in a weak gravitational field

    International Nuclear Information System (INIS)

    Bimonte, Giuseppe; Calloni, Enrico; Esposito, Giampiero; Rosa, Luigi

    2006-01-01

    The influence of the gravity acceleration on the regularized energy-momentum tensor of the quantized electromagnetic field between two plane-parallel conducting plates is derived. We use Fermi coordinates and work to first order in the constant acceleration parameter. A perturbative expansion, to this order, of the Green functions involved and of the energy-momentum tensor is derived by means of the covariant geodesic point-splitting procedure. In correspondence to the Green functions satisfying mixed and gauge-invariant boundary conditions, and Ward identities, the energy-momentum tensor is covariantly conserved and satisfies the expected relation between gauge-breaking and ghost parts, while a new simple formula for the trace anomaly is obtained to first order in the constant acceleration. A more systematic derivation is therefore obtained of the theoretical prediction according to which the Casimir device in a weak gravitational field will experience a tiny push in the upwards direction

  12. Field Evaluation of Advances in Energy-Efficiency Practices for Manufactured Homes

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E. [Advanced Residential Integrated Energy Solutions (ARIES) Collaborative, New York, NY (United States); Dentz, J. [Advanced Residential Integrated Energy Solutions (ARIES) Collaborative, New York, NY (United States); Ansanelli, E. [Advanced Residential Integrated Energy Solutions (ARIES) Collaborative, New York, NY (United States); Barker, G. [Advanced Residential Integrated Energy Solutions (ARIES) Collaborative, New York, NY (United States); Rath, P. [Advanced Residential Integrated Energy Solutions (ARIES) Collaborative, New York, NY (United States); Dadia, D. [Advanced Residential Integrated Energy Solutions (ARIES) Collaborative, New York, NY (United States)

    2016-03-01

    Through field-testing and analysis, this project evaluated whole-building approaches and estimated the relative contributions of select technologies toward reducing energy use related to space conditioning in new manufactured homes. Three lab houses of varying designs were built and tested side-by-side under controlled conditions in Russellville, Alabama. The tests provided a valuable indicator of how changes in the construction of manufactured homes can contribute to significant reductions in energy use.

  13. σ-SCF: A direct energy-targeting method to mean-field excited states.

    Science.gov (United States)

    Ye, Hong-Zhou; Welborn, Matthew; Ricke, Nathan D; Van Voorhis, Troy

    2017-12-07

    The mean-field solutions of electronic excited states are much less accessible than ground state (e.g., Hartree-Fock) solutions. Energy-based optimization methods for excited states, like Δ-SCF (self-consistent field), tend to fall into the lowest solution consistent with a given symmetry-a problem known as "variational collapse." In this work, we combine the ideas of direct energy-targeting and variance-based optimization in order to describe excited states at the mean-field level. The resulting method, σ-SCF, has several advantages. First, it allows one to target any desired excited state by specifying a single parameter: a guess of the energy of that state. It can therefore, in principle, find all excited states. Second, it avoids variational collapse by using a variance-based, unconstrained local minimization. As a consequence, all states-ground or excited-are treated on an equal footing. Third, it provides an alternate approach to locate Δ-SCF solutions that are otherwise hardly accessible by the usual non-aufbau configuration initial guess. We present results for this new method for small atoms (He, Be) and molecules (H 2 , HF). We find that σ-SCF is very effective at locating excited states, including individual, high energy excitations within a dense manifold of excited states. Like all single determinant methods, σ-SCF shows prominent spin-symmetry breaking for open shell states and our results suggest that this method could be further improved with spin projection.

  14. Invention profiles and uneven growth in the field of emerging nano-energy

    International Nuclear Information System (INIS)

    Guan, Jiancheng; Liu, Na

    2015-01-01

    This paper aims to synthetically investigate invention profiles and uneven growth of technological knowledge in the emerging nano-energy field, based on patents data extracted from the Derwent Innovation Index (DII) database during the time period 1991–2012. The trend analysis shows that invention in this field has experienced enormous growth and also diversification over the past 22 years. The co-occurrence network of burst technology domains reveals that technology domains constantly burst, and innovative progress in nanotechnology has tremendously contributed to energy production, storage, conversion and harvesting and so on. Nano-energy patented inventions mainly come from a combinatorial process with a very limited role of developing brand-new technological capabilities. Reusing existing technological capabilities including recombination reuse, recombination creation and single reuse is the primary source of inventions. For the impacts of technology networks' embeddedness, we find that network tie strength suppresses the growth of technological knowledge domains, and network status and convergence both facilitate the growth of technological knowledge domains. We expect that this study will provide some enlightenment for inventing or creating new knowledge in emerging fields in complex technological environment. - Highlights: • We define and utilize a unique dataset of nano-energy patents. • We identify and map the burst technological knowledge domains. • Quantitative argument is provided to prove the combinatorial invention. • Impacts of network embeddedness on growth of technology domain are examined. • Network characteristics affect the growth of technology domain

  15. σ-SCF: A direct energy-targeting method to mean-field excited states

    Science.gov (United States)

    Ye, Hong-Zhou; Welborn, Matthew; Ricke, Nathan D.; Van Voorhis, Troy

    2017-12-01

    The mean-field solutions of electronic excited states are much less accessible than ground state (e.g., Hartree-Fock) solutions. Energy-based optimization methods for excited states, like Δ-SCF (self-consistent field), tend to fall into the lowest solution consistent with a given symmetry—a problem known as "variational collapse." In this work, we combine the ideas of direct energy-targeting and variance-based optimization in order to describe excited states at the mean-field level. The resulting method, σ-SCF, has several advantages. First, it allows one to target any desired excited state by specifying a single parameter: a guess of the energy of that state. It can therefore, in principle, find all excited states. Second, it avoids variational collapse by using a variance-based, unconstrained local minimization. As a consequence, all states—ground or excited—are treated on an equal footing. Third, it provides an alternate approach to locate Δ-SCF solutions that are otherwise hardly accessible by the usual non-aufbau configuration initial guess. We present results for this new method for small atoms (He, Be) and molecules (H2, HF). We find that σ-SCF is very effective at locating excited states, including individual, high energy excitations within a dense manifold of excited states. Like all single determinant methods, σ-SCF shows prominent spin-symmetry breaking for open shell states and our results suggest that this method could be further improved with spin projection.

  16. Time dependence of the field energy densities surrounding sources: Application to scalar mesons near point sources and to electromagnetic fields near molecules

    International Nuclear Information System (INIS)

    Persico, F.; Power, E.A.

    1987-01-01

    The time dependence of the dressing-undressing process, i.e., the acquiring or losing by a source of a boson field intensity and hence of a field energy density in its neighborhood, is considered by examining some simple soluble models. First, the loss of the virtual field is followed in time when a point source is suddenly decoupled from a neutral scalar meson field. Second, an initially bare point source acquires a virtual meson cloud as the coupling is switched on. The third example is that of an initially bare molecule interacting with the vacuum of the electromagnetic field to acquire a virtual photon cloud. In all three cases the dressing-undressing is shown to take place within an expanding sphere of radius r = ct centered at the source. At each point in space the energy density tends, for large times, to that of the ground state of the total system. Differences in the time dependence of the dressing between the massive scalar field and the massless electromagnetic field are discussed. The results are also briefly discussed in the light of Feinberg's ideas on the nature of half-dressed states in quantum field theory

  17. "Brugerens arme og ben"

    DEFF Research Database (Denmark)

    Munk-Madsen, Eva

    Omsorgspraksis, det praktiske, sociale og emotionelle arbejde omsorgsydere udfører i samspil med omsorgsmodtagere, har både diskursive og ikke-diskursive elementer. Disse er imidlertid tæt forbundne via arbejdets mellem-menneskelige karakter. I dette paper er det samspillet mellem diskurs og plej...

  18. Understanding family support

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    2018-01-01

    I anmeldelsen understreges, at fremstillingen henvender sig til praktikere og viser de komplekse samspil mellem politik, teori og praksis og indeholder en stor mængde relevant diskussion af betydning for grundlaget i arbejdet med familier (resilience, social kapital, social hjælp m.v.) og hvordan...

  19. Asymptotic forms for the energy of force-free magnetic field ion figurations of translational symmetry

    Science.gov (United States)

    Sturrock, P. A.; Antiochos, S. K.; Klinchuk, J. A.; Roumeliotis, G.

    1994-01-01

    It is known from computer calculations that if a force-free magnetic field configuration is stressed progressively by footpoint displacements, the configuration expands and approaches the open configuration with the same surface flux distribution and the energy of the field increases progressively. For configurations of translationalsymmetry, it has been found empirically that the energy tends asymptotically to a certain functional form. It is here shown that analysis of a simple model of the asymptotic form of force-free fields of translational symmetry leads to and therefore justifies this functional form. According to this model, the field evolves in a well-behaved manner with no indication of instability or loss of equilibrium.

  20. High Discharge Energy Density at Low Electric Field Using an Aligned Titanium Dioxide/Lead Zirconate Titanate Nanowire Array.

    Science.gov (United States)

    Zhang, Dou; Liu, Weiwei; Guo, Ru; Zhou, Kechao; Luo, Hang

    2018-02-01

    Polymer-based capacitors with high energy density have attracted significant attention in recent years due to their wide range of potential applications in electronic devices. However, the obtained high energy density is predominantly dependent on high applied electric field, e.g., 400-600 kV mm -1 , which may bring more challenges relating to the failure probability. Here, a simple two-step method for synthesizing titanium dioxide/lead zirconate titanate nanowire arrays is exploited and a demonstration of their ability to achieve high discharge energy density capacitors for low operating voltage applications is provided. A high discharge energy density of 6.9 J cm -3 is achieved at low electric fields, i.e., 143 kV mm -1 , which is attributed to the high relative permittivity of 218.9 at 1 kHz and high polarization of 23.35 µC cm -2 at this electric field. The discharge energy density obtained in this work is the highest known for a ceramic/polymer nanocomposite at such a low electric field. The novel nanowire arrays used in this work are applicable to a wide range of fields, such as energy harvesting, energy storage, and photocatalysis.

  1. Binding energy of impurity states in an inverse parabolic quantum well under magnetic field

    International Nuclear Information System (INIS)

    Kasapoglu, E.; Sari, H.; Soekmen, I.

    2007-01-01

    We have investigated the effects of the magnetic field which is directed perpendicular to the well on the binding energy of the hydrogenic impurities in an inverse parabolic quantum well (IPQW) with different widths as well as different Al concentrations at the well center. The Al concentration at the barriers was always x max =0.3. The calculations were performed within the effective mass approximation, using a variational method. We observe that IPQW structure turns into parabolic quantum well with the inversion effect of the magnetic field and donor impurity binding energy in IPQW strongly depends on the magnetic field, Al concentration at the well center and well dimensions

  2. Quantum energy teleportation with an electromagnetic field: discrete versus continuous variables

    International Nuclear Information System (INIS)

    Hotta, Masahiro

    2010-01-01

    It is well known that usual quantum teleportation protocols cannot transport energy. Recently, new protocols called quantum energy teleportation (QET) have been proposed, which transport energy by local operations and classical communication with the ground states of many-body quantum systems. In this paper, we compare two different QET protocols for transporting energy with the electromagnetic field. In the first protocol, a 1/2 spin (a qubit) is coupled with the quantum fluctuation in the vacuum state and measured in order to obtain one-bit information about the fluctuation for the teleportation. In the second protocol, a harmonic oscillator is coupled with the fluctuation and measured in order to obtain continuous-variable information about the fluctuation. In the spin protocol, the amount of teleported energy is suppressed by an exponential damping factor when the amount of input energy increases. This suppression factor becomes power damping in the case of the harmonic oscillator protocol. Therefore, it is concluded that obtaining more information about the quantum fluctuation leads to teleporting more energy. This result suggests a profound relationship between energy and quantum information.

  3. Resonant Wave Energy Converters: Small-scale field experiments and first full-scale prototype

    International Nuclear Information System (INIS)

    Arena, Felice; Fiamma, Vincenzo; Iannolo, Roberto; Laface, Valentina; Malara, Giovanni; Romolo, Alessandra; Strati Federica Maria

    2015-01-01

    The Resonant Wave Energy Converter 3 (REWEC3) is a device belonging to the family of Oscillating Water Columns (OWCs), that can convert the energy of incident waves into electrical energy via turbines. In contrast to classical OWCs, it incorporates a small vertical U-shaped duct to connect the water column to the open wave field. This article shows the results of a small-scale field experiment involving a REWEC3 designed for working with a 2 kW turbine. Then, the next experimental activity on a REWEC3 installed in the NOEL laboratory with the collaboration of ENEA, is presented. Finally, the first prototype of ReWEC3 under construction in Civitavecchia (Rome, Italy) is shown. The crucial features of the construction stage are discussed and some initial performances are provided. [it

  4. Standardization of radiation protection measurements in mixed fields of an extended energy range

    International Nuclear Information System (INIS)

    Hoefert, M.; Stevenson, G.R.

    1977-01-01

    The improved ICRU concept of dose equivalent index aims at standardizing both area and personnel dose measurements so that the results on the dosimetry of external irradiations in radiation protection become compatible. It seems that for photon and neutron energies up to 3 and 20 MeV respectively the realization of dose-equivalent index is straightforward, but the inclusion of higher energies and/or other types of radiation will lead both to conceptual and practical difficulties. It will be shown that practical measurements in mixed radiation fields of an extended energy range for protection purposes will overestimate the standardized quantity. While area measurements can be performed to represent a good approximation, greater uncertainties have to be accepted in personnel dosimetry for stray radiation fields around GeV proton accelerators

  5. A method to detect ultra high energy electrons using earth's magnetic field as a radiator

    Science.gov (United States)

    Stephens, S. A.; Balasubrahmanyan, V. K.

    1983-01-01

    It is pointed out that the detection of electrons with energies exceeding a few TeV, which lose energy rapidly through synchrotron and inverse Compton processes, would provide valuable information on the distribution of sources and on the propagation of cosmic rays in the solar neighborhood. However, it would not be possible to measure the energy spectrum beyond a few TeV with any of the existing experimental techniques. The present investigation is, therefore concerned with the possibility of detecting electrons with energies exceeding a few TeV on the basis of the photons emitted through synchrotron radiation in the earth's magnetic field. Attention is given to the synchrotron radiation of electrons in the earth's magnetic field, detector response and energy estimation, and the characteristics of an ideal detector, capable of detecting photons with energies equal to or greater than 20 keV.

  6. Influence of proceedings papers on citation impact in seven sub-fields of sustainable energy research 2005–2011

    DEFF Research Database (Denmark)

    Ingwersen, Peter; Larsen, Birger; Garcia-Zorita, J. Carlos

    2014-01-01

    and Wave Energy, Geo-thermal, Bio-fuel and Bio-mass energy ub-fields. The analyses cover peer reviewed research and review articles as well as two kinds of proceeding papers from conferences published 2005–2009 in (a) book series or volumes and (b) special journal issues excluding meeting abstracts cited......This paper analyses the following seven sub-fields of Sustainable Energy Research with respect to the influence of proceedings papers on citation patterns across citing and cited document types, overall sub-field and document type impacts and citedness: the Wind Power, Renewable Energy, Solar...

  7. Droplet size characteristics and energy input requirements of emulsions formed using high-intensity-pulsed electric fields

    International Nuclear Information System (INIS)

    Scott, T.C.; Sisson, W.G.

    1987-01-01

    Experimental methods have been developed to measure droplet size characteristics and energy inputs associated with the rupture of aqueous droplets by high-intensity-pulsed electric fields. The combination of in situ microscope optics and high-speed video cameras allows reliable observation of liquid droplets down to 0.5 μm in size. Videotapes of electric-field-created emulsions reveal that average droplet sizes of less than 5 μm are easily obtained in such systems. Analysis of the energy inputs into the fluids indicates that the electric field method requires less than 1% of the energy required from mechanical agitation to create comparable droplet sizes. 11 refs., 3 figs., 2 tabs

  8. Dataset on information strategies for energy conservation: A field experiment in India.

    Science.gov (United States)

    Chen, Victor L; Delmas, Magali A; Locke, Stephen L; Singh, Amarjeet

    2018-02-01

    The data presented in this article are related to the research article entitled: "Information strategies for energy conservation: a field experiment in India" (Chen et al., 2017) [1]. The availability of high-resolution electricity data offers benefits to both utilities and consumers to understand the dynamics of energy consumption for example, between billing periods or times of peak demand. However, few public datasets with high-temporal resolution have been available to researchers on electricity use, especially at the appliance-level. This article describes data collected in a residential field experiment for 19 apartments at an Indian faculty housing complex during the period from August 1, 2013 to May 12, 2014. The dataset includes detailed information about electricity consumption. It also includes information on apartment characteristics and hourly weather variation to enable further studies of energy performance. These data can be used by researchers as training datasets to evaluate electricity usage consumption.

  9. An investigation of build-up effects in high energy radiation fields using a Handi TEPC

    International Nuclear Information System (INIS)

    Aroua, A.; Sannikov, A.V.

    1995-01-01

    ICRP considers that a dose limit of 2 mSv close to the body surface of a pregnant woman will ensure a dose limit of 1 mSv to the foetus. This assumption depends on the energy spectrum and composition of the radiation fields, especially those containing high energy particles such as are found around particle accelerators or in aircraft. In this work the response of a tissue-equivalent proportional counter in radiation fields of different composition and energy was measured as a function of depth in cylindrical phantoms. The decrease in dose and dose equivalent at a phantom depth equivalent to that of a foetus was 10% in a typical high energy stray radiation field and 30% for neutrons from a Pu-Be source. It is concluded that it would be prudent in these cases to limit the exposure of a pregnant woman to 1 mSv in order to ensure that the dose to the foetus stays below the same limit. (Author)

  10. Wave properties near the subsolar magnetopause - Pc 3-4 energy coupling for northward interplanetary magnetic field

    Science.gov (United States)

    Song, P.; Russell, C. T.; Strangeway, R. J.; Wygant, J. R.; Cattell, C. A.; Fitzenreiter, R. J.; Anderson, R. R.

    1993-01-01

    Strong slow mode waves in the Pc 3-4 frequency range are found in the magnetosheath close to the magnetopause. We have studied these waves at one of the ISEE subsolar magnetopause crossings using the magnetic field, electric field, and plasma measurements. We use the pressure balance at the magnetopause to calibrate the Fast Plasma Experiment data versus the magnetometer data. When we perform such a calibration and renormalization, we find that the slow mode structures are not in pressure balance and small scale fluctuations in the total pressure still remain in the Pc 3-4 range. Energy in the total pressure fluctuations can be transmitted through the magnetopause by boundary motions. The Poynting flux calculated from the electric and magnetic field measurements suggests that a net Poynting flux is transmitted into the magnetopause. The two independent measurements show a similar energy transmission coefficient. The transmitted energy flux is about 18 percent of the magnetic energy flux of the waves in the magnetosheath. Part of this transmitted energy is lost in the sheath transition layer before it enters the closed field line region. The waves reaching the boundary layer decay rapidly. Little wave power is transmitted into the magnetosphere.

  11. Initial study - compilation and synthesis of knowledge about energy crops from field to energy production

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Magnus; Bubholz, Monika; Forsberg, Maya; Myringer, Aase; Palm, Ola; Roennbaeck, Marie; Tullin, Claes

    2007-11-15

    Energy crops constitute an yet not fully utilised potential as fuel for heating and power production. As competition for biomass increases interest in agricultural fuels such as straw, energy grain, willow, reed canary grass and hemp is increasing. Exploiting the potential for energy crops as fuels will demand that cultivation and harvest be coordinated with transportation, storage and combustion of the crops. Together, Vaermeforsk and the Swedish Farmers' Foundation for Agricultural Research (SLF), have taken the initiative to a common research programme. The long-term aim of the programme is to increase production and utilisation of bioenergy from agriculture to combustion for heat and power production in Sweden. The vision is that during the course of the 2006 - 2009 programme, decisive steps will be taken towards a functioning market for biofuels for bioenergy from agriculture. This survey has compiled and synthesised available knowledge and experiences about energy crops from field to energy production. The aim has been to provide a snapshot of knowledge today, to identify knowledge gaps and to synthesise knowledge we have today into future research needs. A research plan proposal has been developed for the research programme

  12. Low energy microcolumn for large field view inspection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Chul [Department of Optometry, Eulji University, 212 Yangji-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do 461-713 (Korea, Republic of); Ahn, Seung-Joon; Oh, Tae-Sik; Kim, Dae-Wook [Department of Nanoscience, Sun Moon University 100 Kalsan-ri, Tangjeong-myun, Asan-si, Chungnam 336-708 (Korea, Republic of); Kim, Ho-Seob, E-mail: hskim3@sunmoon.ac.kr [Department of Nanoscience, Sun Moon University 100 Kalsan-ri, Tangjeong-myun, Asan-si, Chungnam 336-708 (Korea, Republic of); Jang, Won Kweon [Division of Electronic, Computer and Communication Engineering, Hanseo University 360 DaeKook-ri, Haemi-myun, Seosan-si, Chungnam 356-706 (Korea, Republic of)

    2011-12-15

    Since the development of microcolumn system, it attracted much attention because multiple microcolumns can be assembled into arrayed form, which is expected to generate multiple electron beams and overcome the disadvantage of electron beam inspection equipments, low throughput . However, it is not easy to apply a microcolumn to the practical inspection or testing equipment since its scanning area is too small. Even if the arrayed operation using multiple microcolumns can overcome this limit, it requires complicated supporting systems and related technologies to operate a number of microcolumns simultaneously. Therefore, we tried to modify microcolumn design itself so that it can have a large field of view. In this work, two kinds of modified columns will be suggested and the preliminary results showing their performance of scanning large area will be discussed. -- Highlights: Black-Right-Pointing-Pointer Two types of microcolumn designs to achieve a large field of view are fabricated. Black-Right-Pointing-Pointer Field of view of a microcolumn increases linearly with the working distance. Black-Right-Pointing-Pointer New designed microcolumns can be developed as a low energy column system for large view inspections.

  13. Energy-momentum tensor of the gravitational field for material spheres

    International Nuclear Information System (INIS)

    Sokolov, S.N.

    1990-01-01

    Density of the energy-momentum tensor of a gravitational field which can be defined in the general relativity theory with the help of ideas of the relativistic gravitational theory is found for the case of material spheres. A relationship of this quantity with the Riemann tensor R αβγδ is discussed

  14. Energy momentum tensor in theories with scalar field

    International Nuclear Information System (INIS)

    Joglekar, S.D.

    1992-01-01

    The renormalization of energy momentum tensor in theories with scalar fields and two coupling constants is considered. The need for addition of an improvement term is shown. Two possible forms for the improvement term are: (i) One in which the improvement coefficient is a finite function of bare parameters of the theory (so that the energy-momentum tensor can be derived from an action that is a finite function of bare quantities), (ii) One in which the improvement coefficient is a finite quantity, i.e. finite function of the renormalized quantities are considered. Four possible model of such theories are (i) Scalar Q.E.D. (ii) Non-Abelian theory with scalars, (iii) Yukawa theory, (iv) A model with two scalars. In all these theories a negative conclusion is established: neither forms for the improvement terms lead to a finite energy momentum tensor. Physically this means that when interaction with external gravity is incorporated in such a model, additional experimental input in the form of root mean square mass radius must be given to specify the theory completely, and the flat space parameters are insufficient. (author). 12 refs

  15. Radon studies for extending Los Azufres geothermal energy field in Mexico

    International Nuclear Information System (INIS)

    Tavera, L.; Balcazar, M.; Camacho, M.E.; Chavez, A.; Perez, H.; Gomez, J.

    1999-01-01

    Los Azufres is a 98 MW producing geothermal energy field situated in the Mexican volcanic belt at the west part of the country. Recently, hydrothermal activity and geochemical analysis of geothermal fluids from the north part of the geothermal field gave indications of a possible geothermal-production area, similar to the already producing field. In order to investigate the activity of geological structures, which are considered the means of geothermal fluids transporters, radon mapping was carried out using sets of 240 LR-115 detectors in the area of interest. Radon values higher than 10 kBq m -3 were considered anomalous and indicative of geothermal anomalies

  16. Radon studies for extending Los Azufres geothermal energy field in Mexico

    CERN Document Server

    Tavera, L; Camacho, M E; Chavez, A; Pérez, H; Gómez, J

    1999-01-01

    Los Azufres is a 98 MW producing geothermal energy field situated in the Mexican volcanic belt at the west part of the country. Recently, hydrothermal activity and geochemical analysis of geothermal fluids from the north part of the geothermal field gave indications of a possible geothermal-production area, similar to the already producing field. In order to investigate the activity of geological structures, which are considered the means of geothermal fluids transporters, radon mapping was carried out using sets of 240 LR-115 detectors in the area of interest. Radon values higher than 10 kBq m sup - sup 3 were considered anomalous and indicative of geothermal anomalies.

  17. MULTILATERAL COOPERATION IN THE BLACK SEA REGION IN THE ENERGY FIELD

    Directory of Open Access Journals (Sweden)

    Andrey Vyacheslavovich Ishin

    2015-01-01

    Full Text Available In the article the state of international cooperation is analysed in the field of energy in Black Sea besseyne. Problems and prospects of development of power communications, their influence, are examined on the level of international stability.

  18. Vejledning - valg og læring

    DEFF Research Database (Denmark)

    Skovhus, Randi Boelskifte

    2017-01-01

    Afhandlingen undersøger, hvordan uddannelses-, erhvervs- og karrierevejledning i skolen udfolder sig i samspil med lærere og med det øvrige der foregår i skolen, og hvordan vejledningen giver mening for unge. Afhandlingens analyser giver indsigt i de unges deltagelse i vejledningen og diskuteres ...

  19. Asphalt Pavement Pothole Detection and Segmentation Based on Wavelet Energy Field

    Directory of Open Access Journals (Sweden)

    Penghui Wang

    2017-01-01

    Full Text Available Potholes are one type of pavement surface distresses whose assessment is essential for developing road network maintenance strategies. Existing methods for automatic pothole detection either rely on expensive and high-maintenance equipment or could not segment the pothole accurately. In this paper, an asphalt pavement pothole detection and segmentation method based on energy field is put forward. The proposed method mainly includes two processes. Firstly, the wavelet energy field of the pavement image is constructed to detect the pothole by morphological processing and geometric criterions. Secondly, the detected pothole is segmented by Markov random field model and the pothole edge is extracted accurately. This methodology has been implemented in a MATLAB prototype, trained, and tested on 120 pavement images. The results show that it can effectively distinguish potholes from cracks, patches, greasy dirt, shadows, and manhole covers and accurately segment the pothole. For pothole detection, the method reaches an overall accuracy of 86.7%, with 83.3% precision and 87.5% recall. For pothole segmentation, the overlap degree between the extracted pothole region and the original pothole region is mostly more than 85%, which accounts for 88.6% of the total detected pavement pothole images.

  20. Flavour fields in steady state: stress tensor and free energy

    International Nuclear Information System (INIS)

    Banerjee, Avik; Kundu, Arnab; Kundu, Sandipan

    2016-01-01

    The dynamics of a probe brane in a given gravitational background is governed by the Dirac-Born-Infeld action. The corresponding open string metric arises naturally in studying the fluctuations on the probe. In Gauge-String duality, it is known that in the presence of a constant electric field on the worldvolume of the probe, the open string metric acquires an event horizon and therefore the fluctuation modes on the probe experience an effective temperature. In this article, we bring together various properties of such a system to a formal definition and a subsequent narration of the effective thermodynamics and the stress tensor of the corresponding flavour fields, also including a non-vanishing chemical potential. In doing so, we point out a potentially infinitely-degenerate scheme-dependence of regularizing the free energy, which nevertheless yields a universal contribution in certain cases. This universal piece appears as the coefficient of a log-divergence in free energy when a space-filling probe brane is embedded in AdS d+1 -background, for d=2,4, and is related to conformal anomaly. For the special case of d=2, the universal factor has a striking resemblance to the well-known heat current formula in (1+1)-dimensional conformal field theory in steady-state, which endows a plausible physical interpretation to it. Interestingly, we observe a vanishing conformal anomaly in d=6.

  1. Monte Carlo calculations for intermediate-energy standard neutron field

    International Nuclear Information System (INIS)

    Joneja, O.P.; Subbukutty, K.; Iyengar, S.B.D.; Navalkar, M.P.

    Intermediate-Energy Standard Neutron Field (ISNF) which produces a well characterised spectrum in the energy range of interest for fast reactors including breeders, has been set up at NBS using thin enriched 235 U fission sources. A proposal has been made for setting up a similar facility at BARC using however, easily available natural U instead of enriched U sources, to start with. In order to simulate the neutronics of such a facility Monte Carlo method of calculations has been adopted and developed. The results of these calculations have been compared with those of NBS and it is found that there may be a maximum difference of 10% in spectrum characteristics for the two cases of using thick and thin fission sources. (K.B.)

  2. Energy levels of mesic molecules ddμ and dt μ in a homogeneous magnetic field

    International Nuclear Information System (INIS)

    Choi Nam Chol.

    1990-01-01

    The energy levels of mesic molecules ddμ and dtμ in a homogeneous magnetic field 0-10 8 Gs have been calculated. Calculations are carried out in the adiabatic representation of three-body problem. It is shown that in really existing fields ( 5 Gs) the shifts of energy levels produce no considerable effect on the process of resonant production of mesic molecules. 13 refs.; 3 figs.; 2 tabs

  3. Characterisation of neutron fields around high-energy x-ray radiotherapy machines

    Czech Academy of Sciences Publication Activity Database

    Králík, M.; Turek, Karel

    2004-01-01

    Roč. 110, 1-4 (2004), s. 503-507 ISSN 0144-8420 Institutional research plan: CEZ:AV0Z1048901 Keywords : radiotherapy machines * neutron fields * high-energy Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 0.617, year: 2003

  4. Quantum fields interacting with colliding plane waves: the stress-energy tensor and backreaction

    International Nuclear Information System (INIS)

    Dorca, M.; Verdaguer, E.

    1997-01-01

    Following a previous work on the quantization of a massless scalar field in a space-time representing the head on collision of two plane waves which focus into a Killing-Cauchy horizon, we compute the renormalized expectation value of the stress-energy tensor of the quantum field near that horizon in the physical state which corresponds to the Minkowski vacuum before the collision of the waves. It is found that for minimally coupled and conformally coupled scalar fields the respective stress-energy tensors are unbounded in the horizon. The specific form of the divergences suggests that when the semiclassical Einstein equations describing the backreaction of the quantum fields on the space-time geometry are taken into account, the horizon will acquire a curvature singularity. Thus the Killing-Cauchy horizon which is known to be unstable under ''generic'' classical perturbations is also unstable by vacuum polarization. The calculation is done following the point-splitting regularization technique. The dynamical colliding wave space-time has four quite distinct space-time regions, namely, one flat region, two single plane wave regions, and one interaction region. Exact mode solutions of the quantum field equation cannot be found exactly, but the blueshift suffered by the initial modes in the plane wave and interaction regions makes the use of the WKB expansion a suitable method of solution. To ensure the correct regularization of the stress-energy tensor, the initial flat modes propagated into the interaction region must be given to a rather high adiabatic order of approximation. (orig.)

  5. Optimal path-finding through mental exploration based on neural energy field gradients.

    Science.gov (United States)

    Wang, Yihong; Wang, Rubin; Zhu, Yating

    2017-02-01

    Rodent animal can accomplish self-locating and path-finding task by forming a cognitive map in the hippocampus representing the environment. In the classical model of the cognitive map, the system (artificial animal) needs large amounts of physical exploration to study spatial environment to solve path-finding problems, which costs too much time and energy. Although Hopfield's mental exploration model makes up for the deficiency mentioned above, the path is still not efficient enough. Moreover, his model mainly focused on the artificial neural network, and clear physiological meanings has not been addressed. In this work, based on the concept of mental exploration, neural energy coding theory has been applied to the novel calculation model to solve the path-finding problem. Energy field is constructed on the basis of the firing power of place cell clusters, and the energy field gradient can be used in mental exploration to solve path-finding problems. The study shows that the new mental exploration model can efficiently find the optimal path, and present the learning process with biophysical meaning as well. We also analyzed the parameters of the model which affect the path efficiency. This new idea verifies the importance of place cell and synapse in spatial memory and proves that energy coding is effective to study cognitive activities. This may provide the theoretical basis for the neural dynamics mechanism of spatial memory.

  6. Characterization of secondary electron collection for energy recovery from high energy ions with a magnetic field

    International Nuclear Information System (INIS)

    Hagihara, Shota; Wada, Takayuki; Nakamoto, Satoshi; Takeno, Hiromasa; Yasaka, Yasuyoshi; Furuyama, Yuichi; Taniike, Akira

    2015-01-01

    A traveling wave direct energy converter (TWDEC) is expected to be used as an energy recovery device for fast protons produced during the D- 3 He nuclear fusion reaction. Some protons, however, are not fully decelerated and pass through the device. A secondary electron direct energy converter (SEDEC) was proposed as an additional device to recover the protons passing through a TWDEC. In our previous study, magnetic field was applied for efficient secondary electron (SE) collection, but the SEs were reflected close to the collector due to the magnetic mirror effect and the collection was degraded. Herein, a new arrangement of magnets is proposed to be set away from the collector, and experiments in various conditions are performed. An appropriate arrangement away from the collector resulted in the improvement of SE collection. (author)

  7. Maximum field capability of energy saver superconducting magnets

    International Nuclear Information System (INIS)

    Turkot, F.; Cooper, W.E.; Hanft, R.; McInturff, A.

    1983-01-01

    At an energy of 1 TeV the superconducting cable in the Energy Saver dipole magnets will be operating at ca. 96% of its nominal short sample limit; the corresponding number in the quadrupole magnets will be 81%. All magnets for the Saver are individually tested for maximum current capability under two modes of operation; some 900 dipoles and 275 quadrupoles have now been measured. The dipole winding is composed of four individually wound coils which in general come from four different reels of cable. As part of the magnet fabrication quality control a short piece of cable from both ends of each reel has its critical current measured at 5T and 4.3K. In this paper the authors describe and present the statistical results of the maximum field tests (including quench and cycle) on Saver dipole and quadrupole magnets and explore the correlation of these tests with cable critical current

  8. Quark self-energy beyond the mean field at finite temperature

    International Nuclear Information System (INIS)

    Zhuang, P.

    1995-01-01

    The Nambu--Jona-Lasinio model, an effective low-energy model of QCD, is extended to the next to the leading order in the 1/N c expansion at finite temperature and density. The contributions to the quark self-energy and the constituent quark mass from the meson dressing are considered in a perturbative approach about the mean field. In particular, the temperature dependence of the quark mass is shown numerically at zero chemical potential. The correction to the quark mass from the meson dressing amounts to 20% compared to the result of the leading order at low temperature, and rapidly approaches zero at high temperature

  9. Alaska North Slope National Energy Strategy initiative: Analysis of five undeveloped fields

    International Nuclear Information System (INIS)

    Thomas, C.P.; Allaire, R.B.; Doughty, T.C.; Faulder, D.D.; Irving, J.S.; Jamison, H.C.; White, G.J.

    1993-05-01

    The US Department of Energy was directed in the National Energy Strategy to establish a federal interagency task force to identify specific technical and regulatory barriers to the development of five undeveloped North Slope Alaska fields and make recommendations for their resolution. The five fields are West Sak, Point Thomson, Gwydyr Bay, Seal Island/Northstar, and Sandpiper Island. Analysis of environmental, regulatory, technical, and economic information, and data relating to the development potential of the five fields leads to the following conclusions: Development of the five fields would result in an estimated total of 1,055 million barrels of oil and 4.4 trillion cubic feet of natural gas and total investment of $9.4 billion in 1992 dollars. It appears that all five of the fields will remain economically marginal developments unless there is significant improvement in world oil prices. Costs of regulatory compliance and mitigation, and costs to reduce or maintain environmental impacts at acceptable levels influence project investments and operating costs and must be considered in the development decision making process. The development of three of the fields (West Sak, Point Thomson, and Gwydyr Bay) that are marginally feasible would have an impact on North Slope production over the period from about 2000 to 2014 but cannot replace the decline in Prudhoe Bay Unit production or maintain the operation of the Trans-Alaska Pipeline System (TAPS) beyond about 2014 with the assumption that the TAPS will shut down when production declines to the range of 400 to 200 thousand barrels of oil/day. Recoverable reserves left in the ground in the currently producing fields and soon to be developed fields, Niakuk and Point McIntyre, would range from 1 billion to 500 million barrels of oil corresponding to the time period of 2008 to 2014 based on the TAPS shutdown assumption

  10. Alaska North Slope National Energy Strategy initiative: Analysis of five undeveloped fields

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.P.; Allaire, R.B.; Doughty, T.C.; Faulder, D.D.; Irving, J.S.; Jamison, H.C.; White, G.J.

    1993-05-01

    The US Department of Energy was directed in the National Energy Strategy to establish a federal interagency task force to identify specific technical and regulatory barriers to the development of five undeveloped North Slope Alaska fields and make recommendations for their resolution. The five fields are West Sak, Point Thomson, Gwydyr Bay, Seal Island/Northstar, and Sandpiper Island. Analysis of environmental, regulatory, technical, and economic information, and data relating to the development potential of the five fields leads to the following conclusions: Development of the five fields would result in an estimated total of 1,055 million barrels of oil and 4.4 trillion cubic feet of natural gas and total investment of $9.4 billion in 1992 dollars. It appears that all five of the fields will remain economically marginal developments unless there is significant improvement in world oil prices. Costs of regulatory compliance and mitigation, and costs to reduce or maintain environmental impacts at acceptable levels influence project investments and operating costs and must be considered in the development decision making process. The development of three of the fields (West Sak, Point Thomson, and Gwydyr Bay) that are marginally feasible would have an impact on North Slope production over the period from about 2000 to 2014 but cannot replace the decline in Prudhoe Bay Unit production or maintain the operation of the Trans-Alaska Pipeline System (TAPS) beyond about 2014 with the assumption that the TAPS will shut down when production declines to the range of 400 to 200 thousand barrels of oil/day. Recoverable reserves left in the ground in the currently producing fields and soon to be developed fields, Niakuk and Point McIntyre, would range from 1 billion to 500 million barrels of oil corresponding to the time period of 2008 to 2014 based on the TAPS shutdown assumption.

  11. Resolving the 180-degree ambiguity in vector magnetic field measurements: The 'minimum' energy solution

    Science.gov (United States)

    Metcalf, Thomas R.

    1994-01-01

    I present a robust algorithm that resolves the 180-deg ambiguity in measurements of the solar vector magnetic field. The technique simultaneously minimizes both the divergence of the magnetic field and the electric current density using a simulated annealing algorithm. This results in the field orientation with approximately minimum free energy. The technique is well-founded physically and is simple to implement.

  12. Energy modulation of nonrelativistic electrons in an optical near field on a metal microslit

    Science.gov (United States)

    Ishikawa, R.; Bae, J.; Mizuno, K.

    2001-04-01

    Energy modulation of nonrelativistic electrons with a laser beam using a metal microslit as an interaction circuit has been investigated. An optical near field is induced in the proximity of the microslit by illumination of the laser beam. The electrons passing close to the slit are accelerated or decelerated by an evanescent wave contained in the near field whose phase velocity is equal to the velocity of the electrons. The electron-evanescent wave interaction in the microslit has been analyzed theoretically and experimentally. The theory has predicted that electron energy can be modulated at optical frequencies. Experiments performed in the infrared region have verified theoretical predictions. The electron-energy changes of more than ±5 eV with a 10 kW CO2 laser pulse at the wavelength of 10.6 μm has been successfully observed for an electron beam with an energy of less than 80 keV.

  13. Livssyn & persuasion

    DEFF Research Database (Denmark)

    Sørensen, Christian Grund

    Hvad er meningen med livet? Dette spørgsmål har optaget mennesket fra tidernes morgen, og vil formodentlig fortsætte dermed. Dette ph.d.-studie diskuterer, hvordan der kan være et samspil mellem de interaktive, digitale medier og en argumenteret og reflekteret livssynsdiskurs. Studiet relaterer s...

  14. Udfordringer og mulige veje for den nye fællesfaglighed i naturfagene i folkeskolen

    DEFF Research Database (Denmark)

    Krogh, Lars Brian; Daugbjerg, Peer; Ormstrup, Inger Charlotte Nautrup

    2016-01-01

    samspil, samt deres holdninger til denne type undervisning. Åbne respons-felter gav lærerne mulighed for at give konkrete eksempler fra praksis og beskrive centrale udfordringer. Et diverst convenience-sample (N=94) af lærere fra alle naturfag i overbygningen besvarede spørgeskemaet. Pilotafprøvningen af...

  15. Future competence needs in public libraries

    DEFF Research Database (Denmark)

    Konrad, Ingelise

    2010-01-01

    Fremtidens biblioteker har behov for ledere, der løbende kan arbejde med forandrings- og udviklingsprocesser i samspil med organisationen og dens omverden samt for medarbejdere, der kan tage ledelse på sig i forhold til projekter mv. Det forudsætter medarbejdere og ledere med stærke metakompetencer...

  16. Social(de)konstruktivisme

    DEFF Research Database (Denmark)

    Hansen, Ole Henrik

    2009-01-01

    Det levede barneliv indeholder mere end summen af de umiddelbart tilgængelige elementer. Det tidslige samspil mellem forskellige interfererende fænomener udskiller merværdier, der dels giver nuet dets særpræg, og samtidig medvirker som skjult indhold i barnets tidslige subjektgørelse. Udgivelsesd...

  17. Report of the Energy Field Institute V on western energy opportunities, problems, and policy issues

    International Nuclear Information System (INIS)

    Hepworth, J.C.; Foss, M.M.

    1982-12-01

    The fifth Energy and Minerals Field Institute program for Washington, D.C. Congressional and Executive Aides was held during August 15-21, 1982. The five-and-one-half day program was conducted through Wyoming, Colorado and Utah and consisted of visits to: an R and D tertiary petroleum production facility; an historic oil field entering secondary production; a surface uranium mine; a petroleum exploration drilling rig; a surface coal mine; an air cooled, coal-fired power plant; an oil shale site; a geothermal-electrical generating facility; and open pit copper mine and associated smelter and refinery; a petroleum refinery and an oil shale semi-works retort. During the field program, participants had opportunities to view communities affected by these activities, such as Wright City and Gillette, Wyoming, Parachute, Colorado and Milford and Cedar City, Utah. Throughout the program, aides met with local, state and industry officials and citizen leaders during bus rides, meals and site visits

  18. Report of the Energy Field Institute V on western energy opportunities, problems, and policy issues

    Energy Technology Data Exchange (ETDEWEB)

    Hepworth, J.C.; Foss, M.M.

    1982-12-01

    The fifth Energy and Minerals Field Institute program for Washington, D.C. Congressional and Executive Aides was held during August 15-21, 1982. The five-and-one-half day program was conducted through Wyoming, Colorado and Utah and consisted of visits to: an R and D tertiary petroleum production facility; an historic oil field entering secondary production; a surface uranium mine; a petroleum exploration drilling rig; a surface coal mine; an air cooled, coal-fired power plant; an oil shale site; a geothermal-electrical generating facility; and open pit copper mine and associated smelter and refinery; a petroleum refinery and an oil shale semi-works retort. During the field program, participants had opportunities to view communities affected by these activities, such as Wright City and Gillette, Wyoming, Parachute, Colorado and Milford and Cedar City, Utah. Throughout the program, aides met with local, state and industry officials and citizen leaders during bus rides, meals and site visits.

  19. Do paralympic track and field athletes have low energy availability?

    Directory of Open Access Journals (Sweden)

    Daniel Paduan Joaquim

    2018-03-01

    Full Text Available One of the greatest challenges when working with athletes is to achieve the energy demands for physiological processes and exercise expenditure. The aim of this study was to assess the energy availability (EA of Paralympic track and field athletes (sprinters. Seventeen athletes (9 male and 8 female with visual impairment (VI, n=10, cerebral palsy (CP, n=4 and limb deficiency (LD, n=3 were assessed for energy intake (EI (4-day food photographic record, energy expenditure with exercise (EEex (motion sensor, and body composition (skinfolds method. Energy availability was estimated using the equation: EA = (EIkcal - EEexkcal / fat-free mass (FFM / day, and values ≤ 30kcal/kgFFM/day were considered as low energy availability (LEA. EEex varied from 130 to 477kcal/h and athletes trained in average for 3.2 hours per day. Mean EA for VI, LD and CP were 36 (2.19, 37 (1.90 and 38 (3.38 kcal/kgFFM/day, respectively. Most (82.3% participants presented EA below ≥ 45kcal/kgFFM/day, throughout the days, which are the recommended values for athletes without disability. Athletes should be encouraged to consume adequate EA to avoid consequences related to low energy availability. There is need of further research to identify cut-off values adequate for this population.

  20. Application of CMAC Neural Network to Solar Energy Heliostat Field Fault Diagnosis

    Directory of Open Access Journals (Sweden)

    Neng-Sheng Pai

    2013-01-01

    Full Text Available Solar energy heliostat fields comprise numerous sun tracking platforms. As a result, fault detection is a highly challenging problem. Accordingly, the present study proposes a cerebellar model arithmetic computer (CMAC neutral network for automatically diagnosing faults within the heliostat field in accordance with the rotational speed, vibration, and temperature characteristics of the individual heliostat transmission systems. As compared with radial basis function (RBF neural network and back propagation (BP neural network in the heliostat field fault diagnosis, the experimental results show that the proposed neural network has a low training time, good robustness, and a reliable diagnostic performance. As a result, it provides an ideal solution for fault diagnosis in modern, large-scale heliostat fields.

  1. Note: Enhanced energy harvesting from low-frequency magnetic fields utilizing magneto-mechano-electric composite tuning-fork.

    Science.gov (United States)

    Yang, Aichao; Li, Ping; Wen, Yumei; Yang, Chao; Wang, Decai; Zhang, Feng; Zhang, Jiajia

    2015-06-01

    A magnetic-field energy harvester using a low-frequency magneto-mechano-electric (MME) composite tuning-fork is proposed. This MME composite tuning-fork consists of a copper tuning fork with piezoelectric Pb(Zr(1-x)Ti(x))O3 (PZT) plates bonded near its fixed end and with NdFeB magnets attached at its free ends. Due to the resonance coupling between fork prongs, the MME composite tuning-fork owns strong vibration and high Q value. Experimental results show that the proposed magnetic-field energy harvester using the MME composite tuning-fork exhibits approximately 4 times larger maximum output voltage and 7.2 times higher maximum power than the conventional magnetic-field energy harvester using the MME composite cantilever.

  2. 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.

  3. Transverse electric fields' effects in the Dark Energy Camera CCDs

    International Nuclear Information System (INIS)

    Plazas, A A; Sheldon, E S; Bernstein, G M

    2014-01-01

    Spurious electric fields transverse to the surface of thick CCDs displace the photo-generated charges, effectively modifying the pixel area and producing noticeable signals in astrometric and photometric measurements. We use data from the science verification period of the Dark Energy Survey (DES) to characterize these effects in the Dark Energy Camera (DECam) CCDs, where the transverse fields manifest as concentric rings (impurity gradients or ''tree rings'') and bright stripes near the boundaries of the detectors (''edge distortions'') with relative amplitudes of about 1% and 10%, respectively. Using flat-field images, we derive templates in the five DES photometric bands (grizY) for the tree rings and the edge distortions as a function of their position on each DECam detector. Comparison of the astrometric and photometric residuals confirms their nature as pixel-size variations. The templates are directly incorporated into the derivation of photometric and astrometric residuals. The results presented in these proceedings are a partial report of analysis performed before the workshop ''Precision Astronomy with Fully depleted CDDs'' at Brookhaven National Laboratory. Additional work is underway, and the final results and analysis will be published elsewhere (Plazas, Bernstein and Sheldon 2014, in prep.)

  4. Some consequences of the law of local energy conservation in electromagnetic field

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    2001-01-01

    At electromagnetic interactions of particles there arise defects of masses, i.e. the energy is liberated since the particles of the different charges are attracted. It is shown that this change of the effective mass of a particle in the external electric field (of a nucleus) results in displacement of atomic levels of electrons. The expressions describing these velocity changes and displacement of energy levels of electrons in the atom are obtained

  5. A proximal retarding field analyzer for scanning probe energy loss spectroscopy

    Science.gov (United States)

    Bauer, Karl; Murphy, Shane; Palmer, Richard E.

    2017-03-01

    A compact proximal retarding field analyzer for scanning probe energy loss spectroscopy measurements is described. Using the scanning tunneling microscope (STM) tip as a field emission (FE) electron source in conjunction with this analyzer, which is placed at a glancing angle to the surface plane, FE sample current and electron reflectivity imaging may be performed simultaneously. This is demonstrated in measurements of Ag nanostructures prepared on graphite by electron-beam lithography, where a material contrast of 13% is observed, with a lateral resolution of 25 nm, between the silver and graphite in electron reflectivity images. Topological contrast mechanisms such as edge enhancement and shadowing are also observed, giving rise to additional features in the electron reflectivity images. The same instrument configuration has been used to measure electron energy loss spectra on bare graphite, where the zero loss peak, π band plasmon loss peak and secondary electron peaks are observed. Using this simple and compact analyzer an STM, with sufficient open access to the tip-sample junction, may easily be augmented to provide simultaneous elemental and topographic mapping, supplementing STM image measurements with FE sample current and electron reflectivity images, as well as electron energy loss spectroscopy measurements, in the same instrument.

  6. On the relation between the Einstein and the Komar expressions for the energy of the gravitational field

    International Nuclear Information System (INIS)

    Chrusciel, P.T.

    1985-01-01

    It is shown, that the interpretation of the Einstein energy-momentum ''pseudo-tensor'',''covariantized'' with the help of a background metric, as the energy-momentum tensor of the gravitational field with respect to a background field, is consistent with a geometric hamiltonian analysis. It is also shown, that the von Freud superpotential and the Komar superpotential describe the dynamics of the gravitational field in different function spaces, subject to different boundary conditions. One can pass from one superpotential to the other by performing a Legendre transformation on the boundary. It is explained why the ADM and the von Freud energy expressions are the same, for asymptotically flat space-times

  7. Energy consumption of SO2 removal from humid air under electron beam and electric field influence

    International Nuclear Information System (INIS)

    Nichipor, H.; Radjuk, E.; Chmielewski, A.G.; Zimek, Z.

    1998-01-01

    The kinetic of SO 2 oxidation in humid air under influence of electron beam and electrical field was investigated by computer simulation method in steady state and pulse mode. SO 2 oxidation process was stimulated by radical and ion reactions. The calculation model has included 46 different particles and 160 chemical reactions. Gas mixture containing 1000 ppm of SO 2 concentration was investigated at temperature T=67 deg. C and pressure p=1 at. Water content was within the range 2-12%. Electron beam parameters were as follows: average beam current density 0.0032-3,2 mA/cm 2 , pulse duration 400 μs, repetition rate 50 Hz. Electrical field density was E/n =10 -15 Vcm 2 . Electrical pulse duration was changed within the range 5 x10 -7 -10 -5 s. The influence of the parameters of synchronized electron beam and electrical field pulses on energy deposition was under consideration. Energy cost of SO 2 removal on 90% level was estimated in steady state and pulse modes. It was found that total electron beam and electrical field energy losses in pulse mode are 6 times lower to compare with steady state conditions. The optimum of electrical field pulse duration from point of view minimum energy cost of SO 2 removal was found for different electron beam pulse current levels

  8. Energy dispersion of charged particles decelerated in a two-dimensional electrostatic field of the type x1/n

    International Nuclear Information System (INIS)

    Zashkvara, V.V.; Bok, A.A.

    1992-01-01

    Two components of the spatial dispersion of particles with respect to kinetic energy can be distinguished of the motion of charged particle beams in electrostatic mirros with a two-dimensional field φ(x,y) ans xz symmetry plane. The first is the longitudinal dispersion, which is along the z axis perpendicular to the field; the second is the transverse dispersion, along the x axis parallel to the field vector in the plane of symmetry. The longitudinal dispersion is a basic characteristic of electrostatic mirrors used as energy analyzers. It has been shown that for first-order angular focusing, the longitudinal dispersion, divided by the focal length, is independent of the structure of the two-dimensional field and is a function only of the angle at which the charged particle beam enters the mirror. The transverse dispersion stems from the energy dependence of the penetration depth of the beam as it is decelerated, and it plays an important role when the energy of a charged particle beam is analyzed by the filtering principle, making use of the property of an electrostatic mirror to transmit or reflect charged particles with kinetic energy in a specified interval. This type of dispersion in electrostatic mirrors with two-dimensional fields has not been analyzed systematically. In the present note the authors consider a particular type of two-dimensional electrostatic field which is characterized by a large transverse dispersion, many times larger than in existing electrostatic reflecting filters employing planar and cylindrical fields

  9. An experimental investigation on reduced radiological penumbra for intermediate energy x-rays: Implications for small field radiosurgery

    Science.gov (United States)

    Keller, Brian Michael

    Current day external beam radiation therapy typically uses x-ray energies in the megavoltage (6--18 MV) or in the superficial/orthovoltage (80--350 kVp) energy ranges. It has been found that intermediate energy x-rays (those greater than orthovoltage but sub-megavoltage) may offer an advantage in the field of high precision radiation therapy such as in radiosurgery. This advantage is a reduction in the radiological penumbra associated with small (less than about 3 cm) radiation dose fields. A consequence of reduced radiological penumbra is a more homogenous, conformal dose distribution in the patient with dose escalation and organ sparing made more feasible. The objectives of this thesis were as follows: to produce and to characterize an intermediate energy x-ray beam, to establish a method of accurate penumbra measurement at the micron level for millimeter size fields, to measure the radiological penumbra of single small intermediate energy x-ray fields, and to show the clinical consequences of a multiple beam irradiation in a stereotactic head phantom. A maximum photon energy of 1.2 +/- 0.1 MeV was determined for the intermediate energy x-ray spectrum at the expense of a low dose rate. A digital microscope with a computer controlled translation stage was investigated for its ability to resolve steep dose gradients in Gafchromic EBT film for field sizes as small as 1 mm and for photon energies as low as 100 kVp. The microscope-film system resolved gradients to within about 30 mum, limited by the inherent spatial resolution of the film, the noise of the system, and the uncertainties of measurement. Penumbra widths were compared for 1.2 MV versus 6 MV for identical irradiation conditions. In some instances, there was a five-fold reduction in the radiological penumbra of single 1.2 MV x-ray beams. A multiple beam arc irradiation demonstrated that the advantages seen with single beams carry over to multiple beams. The benefits of reduced radiological penumbra for

  10. Comparative energy input–output and financial analyses of greenhouse and open field vegetables production in West Java, Indonesia

    International Nuclear Information System (INIS)

    Kuswardhani, Nita; Soni, Peeyush; Shivakoti, Ganesh P.

    2013-01-01

    This paper estimates energy consumption per unit floor area of greenhouse and open field for tomato, chili and lettuce production. Primary data were collected from 530 vegetable farmers during Jan–Dec, 2010 in West Java, Indonesia. Energy estimates were calculated from actual amount of inputs and outputs and corresponding conversion factors. Results reveal that the total input energy used in greenhouse (GH) production of tomato, chili (medium and high land) and lettuce were 47.62, 41.55, 58.84, and 24.54 GJ/ha respectively. Whereas, the requirement of total input energy for open field (OF) production of tomato, chili (medium and high land) and lettuce were 49.01, 41.04, 57.94 and 23.87 GJ/ha, respectively. The ratio of output to input energy was higher in greenhouse production (0.85, 0.45 and 0.49) than open field vegetable production (0.52, 0.175 and 0.186) for tomato, chili medium land and chili highland, respectively, but output–input ratio of lettuce open field production was twice as that of greenhouse vegetable production. Financial analysis revealed higher mean net returns from greenhouse vegetable production as 7043 $/ha (922–15,299 $/ha) when compared to 571 $/ha (44–1172 $/ha) from open field vegetable production. Among the greenhouse vegetables, tomato cultivation was the most profitable in terms of energy efficiency and financial productivity. - Highlights: ► Energy input–output analysis is carried out to compare vegetables production in greenhouse and open field. ► Tomato, Chili and Lettuce production in West Java, Indonesia. ► Economic analysis is conducted to compare the two production systems

  11. Digitalisering, professionsnydannelser og teknologiforståelse i Fysioterapeutuddannelsen

    DEFF Research Database (Denmark)

    Hansbøl, Mikala; Jørgensen, Annette

    2015-01-01

    Artiklen præsenterer arbejdet med udviklingen af en digitalt understøttet undervisningsklinik i Fysioterapeutuddannelsen, som den ser ud i dag. Udviklingen er et forsøg på at inkludere et fokus på de studerendes forståelse af samspil mellem digital teknologi og forandringer i det fysioterapiske a...

  12. Musikalsk leg med formgivning, timing og vitalitetsformer

    DEFF Research Database (Denmark)

    Holck, Ulla

    2015-01-01

    Ifølge de Udviklingsorienterede Social-Pragmatiske Interventionsformer til børn med Autisme Spektrum Forstyrrelse er en legende indfaldsvinkel, hvor man følger barnets lead, den mest effektive til at engagere yngre børn med autisme eller børn med svær autisme i et gensidigt samspil. Artiklen...

  13. Resonant transformation of electrostatic energy in ExB field system

    International Nuclear Information System (INIS)

    Tanizuka, Noboru

    1986-01-01

    A theoretical consideration on an effective transformation of electrostatic potential energy is given. A transformator particle is introduced with the transformation in an ExB field system. A device constant of the system is introduced comparing with some empirical, practical examples and an experimental proof of the transformation is given. Finally a nuclear fusion device plan is proposed based on the idea of the consideration. (author)

  14. On Study of Application of Power Electronical Technology in Field of Energy Conservation

    Science.gov (United States)

    Song, Ke

    2017-09-01

    aiming at achieving the sustainable development in economy and improving living standard of the residents, the government departments in China have strengthened the promotion of green, low-carbon and sustainable development concepts. Under this context, the energy conservation concept is implemented during the implementation of social production and life activities. Currently, in order to ensure the improvement in social energy conservation benefits, the advanced technologies are applied by China's enterprises and residents. This paper, based on this, discusses the development situations of energy conservation in China, and analyzes the application of power electronical technology in the field of energy conservation, hoping to realize the sustainable development of energy conservation cause in China and to gain high yield.

  15. A case study of the energy dissipation of the gravity wave field based on satellite altimeter measurements

    Science.gov (United States)

    Huang, N. E.; Parsons, C. L.; Long, S. R.; Bliven, L. F.

    1983-01-01

    Wave breaking is proposed as the primary energy dissipation mechanism for the gravity wave field. The energy dissipation rate is calculated based on the statistical model proposed by Longuet-Higgins (1969) with a modification of the breaking criterion incorporating the surface stress according to Phillips and Banner (1974). From this modified model, an analytic expression is found for the wave attenuation rate and the half-life time of the wave field which depend only on the significant slope of the wave field and the ratio of friction velocity to initial wave phase velocity. These expressions explain why the freshly generated wave field does not last long, but why swells are capable of propagating long distances without substantial change in energy density. It is shown that breaking is many orders of magnitude more effective in dissipating wave energy than the molecular viscosity, if the significant slope is higher than 0.01. Limited observational data from satellite and laboratory are used to compare with the analytic results, and show good agreement.

  16. Effect of an external magnetic field on particle acceleration by a rotating black hole surrounded with quintessential energy

    Science.gov (United States)

    Shaymatov, Sanjar; Ahmedov, Bobomurat; Stuchlík, Zdeněk; Abdujabbarov, Ahmadjon

    We investigate particle motion and collisions in the vicinity of rotating black holes immersed in combined cosmological quintessential scalar field and external magnetic field. The quintessential dark-energy field governing the spacetime structure is characterized by the quintessential state parameter ωq ∈ (‑1; ‑1/3) characterizing its equation of state, and the quintessential field-intensity parameter c determining the static radius where the black hole attraction is just balanced by the quintessential repulsion. The magnetic field is assumed to be test field that is uniform close to the static radius, where the spacetime is nearly flat, being characterized by strength B there. Deformations of the test magnetic field in vicinity of the black hole, caused by the Ricci non-flat spacetime structure are determined. General expression of the center-of-mass energy of the colliding charged or uncharged particles near the black hole is given and discussed in several special cases. In the case of nonrotating black holes, we discuss collisions of two particles freely falling from vicinity of the static radius, or one such a particle colliding with charged particle revolving at the innermost stable circular orbit. In the case of rotating black holes, we discuss briefly particles falling in the equatorial plane and colliding in close vicinity of the black hole horizon, concentrating attention to the interplay of the effects of the quintessential field and the external magnetic field. We demonstrate that the ultra-high center-of-mass energy can be obtained for black holes placed in an external magnetic field for an infinitesimally small quintessential field-intensity parameter c; the center-of-mass energy decreases if the quintessential field-intensity parameter c increases.

  17. Absorption of electromagnetic field energy by superfluid system of atoms with electric dipole moment

    International Nuclear Information System (INIS)

    Poluektov, Yu.M.

    2014-01-01

    The modified Gross-Pitaevskii equation which takes into account relaxation and interaction with alternating electromagnetic field is used to consider the absorption of electromagnetic field energy by a superfluid system on the assumption that the atoms has intrinsic dipole moment. It is shown that the absorption may be of a resonant behavior only if the dispersion curves of the electromagnetic wave and the excitations of the superfluid system intersect. It is remarkable that such a situation is possible if the superfluid system has a branch of excitations with the energy gap at low momenta. The experiments on absorption of microwaves in superfluid helium are interpreted as evidence of existence of such gap excitations. A possible modification of the excitation spectrum of superfluid helium in the presence of excitation branch with energy gap is dis-cussed qualitatively

  18. Calibration in photon radiation fields with energies above 3 MeV

    International Nuclear Information System (INIS)

    Bueermann, L.

    1997-01-01

    For determination of the response of dosemeters and dose ratemeters for photon energies above 3 MeV, the PTB uses reference radiation fields generated via the nuclear reactions 12 (p, p' γ) 12 C (4.4 MeV) and 19 F(p,αγ) 16 O (6-7 MeV). As a maximum, kerma rates of 1 mGy/h released in air can be achieved at 1 m distance from the target. The air kerma in the reference fields is determined with two different methods, i.e. by spectrometry using a Ge detector, and by ionometry using a graphite cavity ionisation chamber. The total uncertainty of the value determined for the air kerma (collision radiation) in the reference fields is 50% at a confidence level of 68.3%. (orig./CB) [de

  19. Field Evaluation of Four Novel Roof Designs for Energy-Efficient Manufactured Homes

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E. [Levy Partnership Inc., New York, NY (United States); Dentz, J. [Levy Partnership Inc., New York, NY (United States); Ansanelli, E. [Levy Partnership Inc., New York, NY (United States); Barker, G. [Levy Partnership Inc., New York, NY (United States); Rath, P. [Levy Partnership Inc., New York, NY (United States); Dadia, D. [Levy Partnership Inc., New York, NY (United States)

    2015-12-01

    A five-bay roof test structure was built, instrumented and monitored in an effort to determine through field testing and analysis the relative contributions of select technologies toward reducing energy use in new manufactured homes. The roof structure in Jamestown, California was designed to examine how differences in roof construction impact space conditioning loads, wood moisture content and attic humidity levels. Conclusions are drawn from the data on the relative energy and moisture performance of various configurations of vented and sealed attics.

  20. Field Evaluation of Four Novel Roof Designs for Energy-Efficient Manufactured Homes

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E. [ARIES Collaborative, New York, NY (United States); Dentz, J. [ARIES Collaborative, New York, NY (United States); Ansanelli, E. [ARIES Collaborative, New York, NY (United States); Barker, G. [ARIES Collaborative, New York, NY (United States); Rath, P. [ARIES Collaborative, New York, NY (United States); Dadia, D. [ARIES Collaborative, New York, NY (United States)

    2015-12-03

    "9A five-bay roof test structure was built, instrumented and monitored in an effort to determine through field testing and analysis the relative contributions of select technologies toward reducing energy use in new manufactured homes. The roof structure in Jamestown, California was designed to examine how differences in roof construction impact space conditioning loads, wood moisture content and attic humidity levels. Conclusions are drawn from the data on the relative energy and moisture performance of various configurations of vented and sealed attics.

  1. Porous media experience applicable to field evaluation for compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Gutknecht, P.J.

    1980-06-01

    A survey is presented of porous media field experience that may aid in the development of a compressed air energy storage field demonstration. Work done at PNL and experience of other groups and related industries is reviewed. An overall view of porous media experience in the underground storage of fluids is presented. CAES experience consists of site evaluation and selection processes used by groups in California, Kansas, and Indiana. Reservoir design and field evaluation of example sites are reported. The studies raised questions about compatibility with depleted oil and gas reservoirs, storage space rights, and compressed air regulations. Related experience embraces technologies of natural gas, thermal energy, and geothermal and hydrogen storage. Natural gas storage technology lends the most toward compressed air storage development, keeping in mind the respective differences between stored fluids, physical conditions, and cycling frequencies. Both fluids are injected under pressure into an aquifer to form a storage bubble confined between a suitable caprock structure and partially displaced ground water. State-of-the-art information is summarized as the necessary foundation material for field planning. Preliminary design criteria are given as recommendations for basic reservoir characteristics. These include geometric dimensions and storage matrix properties such as permeability. Suggested ranges are given for injection air temperature and reservoir pressure. The second step in developmental research is numerical modeling. Results have aided preliminary design by analyzing injection effects upon reservoir pressure, temperature and humidity profiles. Results are reported from laboratory experiments on candidate sandstones and caprocks. Conclusions are drawn, but further verification must be done in the field.

  2. Research study on public relations and public participation in the nuclear energy field

    International Nuclear Information System (INIS)

    Gunji, Ikuko; Tabata, Rimiko; Otoshi, Sachio; Kuwagaki, Reiko; Ishibashi, Yoichiro

    2006-01-01

    The purpose of this research is to clarify the effect of public relations activities in the nuclear energy field and public participation toward the improvement of the risk literacy of nuclear energy. According to the survey results of the actual public relations activities taken by nuclear energy industry, the opportunity for interactive communications between the public and the industry is insufficient. Consequently, we propose building up more opportunities for participation and collaboration of citizens and industries in order to improve interactive communications reflecting public opinions and points of view. (author)

  3. Relativistic Killingbeck energy states under external magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Eshghi, M. [Islamic Azad University, Researchers and Elite Club, Central Tehran Branch, Tehran (Iran, Islamic Republic of); Mehraban, H. [Semnan University, Faculty of Physics, Semnan (Iran, Islamic Republic of); Ikhdair, S.M. [An-Najah National University, Department of Physics, Faculty of Science, Nablus, West Bank, Palestine (Country Unknown); Near East University, Department of Electrical Engineering, Nicosia, Northern Cyprus (Turkey)

    2016-07-15

    We address the behavior of the Dirac equation with the Killingbeck radial potential including the external magnetic and Aharonov-Bohm (AB) flux fields. The spin and pseudo-spin symmetries are considered. The correct bound state spectra and their corresponding wave functions are obtained. We seek such a solution using the biconfluent Heun's differential equation method. Further, we give some of our results at the end of this study. Our final results can be reduced to their non-relativistic forms by simply using some appropriate transformations. The spectra, in the spin and pseudo-spin symmetries, are very similar with a slight difference in energy spacing between different states. (orig.)

  4. Relativistic Killingbeck energy states under external magnetic fields

    International Nuclear Information System (INIS)

    Eshghi, M.; Mehraban, H.; Ikhdair, S.M.

    2016-01-01

    We address the behavior of the Dirac equation with the Killingbeck radial potential including the external magnetic and Aharonov-Bohm (AB) flux fields. The spin and pseudo-spin symmetries are considered. The correct bound state spectra and their corresponding wave functions are obtained. We seek such a solution using the biconfluent Heun's differential equation method. Further, we give some of our results at the end of this study. Our final results can be reduced to their non-relativistic forms by simply using some appropriate transformations. The spectra, in the spin and pseudo-spin symmetries, are very similar with a slight difference in energy spacing between different states. (orig.)

  5. Forskning i musikterapi - børn med fysiske og psykiske funktionsnedsættelser

    DEFF Research Database (Denmark)

    Holck, Ulla

    2013-01-01

    samspil. Samtidig er det muligt at udtrykke frustration, vrede og sorg gennem musik, så børn og unge med fysiske og psykiske funktionsnedsættelser, der har svært ved at udtrykke og bearbejde følelsesmæssige og relationelle problemer, kan opbygge positive relationserfaringer og styrke selvfølelsen vha...

  6. Landau Quasi-energy Spectrum Destruction for an Electron in Both a Static Magnetic Field and a Resonant Electromagnetic Wave

    International Nuclear Information System (INIS)

    Skoblin, A.A.

    1994-01-01

    Free nonrelativistic electrons in both a static magnetic field and an electromagnetic wave are considered. A plane-polarized wave propagates along a magnetic field, its frequency is close to the electron rotation frequency in a magnetic field. Electron spin is taken into account. An electron quasi energy spectrum and steady states (quasi energy states) are constructed. 6 refs

  7. Effects of retarded electrical fields on observables sensitive to the high-density behavior of the nuclear symmetry energy in heavy-ion collisions at intermediate energies

    Science.gov (United States)

    Wei, Gao-Feng; Li, Bao-An; Yong, Gao-Chan; Ou, Li; Cao, Xin-Wei; Liu, Xu-Yang

    2018-03-01

    Within the isospin- and momentum-dependent transport model IBUU11, we examine the relativistic retardation effects of electrical fields on the π-/π+ ratio and neutron-proton differential transverse flow in heavy-ion collisions at intermediate energies. Compared to the static Coulomb fields, the retarded electric fields of fast-moving charges are known to be anisotropic and the associated relativistic corrections can be significant. They are found to increase the number of energetic protons in the participant region at the maximum compression by as much as 25% but that of energetic neutrons by less than 10% in 197Au+197Au reactions at a beam energy of 400 MeV/nucleon. Consequently, more π+ and relatively fewer π- mesons are produced, leading to an appreciable reduction of the π-/π+ ratio compared to calculations with the static Coulomb fields. Also, the neutron-proton differential transverse flow, as another sensitive probe of high-density symmetry energy, is also decreased appreciably due to the stronger retarded electrical fields in directions perpendicular to the velocities of fast-moving charges compared to calculations using the isotropic static electrical fields. Moreover, the retardation effects on these observables are found to be approximately independent of the reaction impact parameter.

  8. Currents and the energy-momentum tensor in classical field theory: a fresh look at an old problem

    International Nuclear Information System (INIS)

    Forger, Michael; Roemer, Hartmann

    2004-01-01

    We give a comprehensive review of various methods to define currents and the energy-momentum tensor in classical field theory, with emphasis on a geometric point of view. The necessity of 'improving' the expressions provided by the canonical Noether procedure is addressed and given an adequate geometric framework. The main new ingredient is the explicit formulation of a principle of 'ultralocality' with respect to the symmetry generators, which is shown to fix the ambiguity inherent in the procedure of improvement and guide it towards a unique answer: when combined with the appropriate splitting of the fields into sectors, it leads to the well-known expressions for the current as the variational derivative of the matter field Lagrangian with respect to the gauge field and for the energy-momentum tensor as the variational derivative of the matter field Lagrangian with respect to the metric tensor. In the second case, the procedure is shown to work even when the matter field Lagrangian depends explicitly on the curvature, thus establishing the correct relation between scale invariance, in the form of local Weyl invariance 'on shell', and tracelessness of the energy-momentum tensor, required for a consistent definition of the concept of a conformal field theory

  9. Basal metabolic rate in relation to body composition and daily energy expenditure in the field vole, Microtus agrestis

    NARCIS (Netherlands)

    Meerlo, P; Bolle, L; Visser, GH; Masman, D; Daan, S

    1997-01-01

    Basal metabolic rate in the field vole (Microtus agrestis) was studied in relation to body composition and daily energy expenditure in the field Daily energy expenditure was measured by means of doubly labelled water ((D2O)-O-18). In the same individuals, basal metabolic rate was subsequently

  10. Energy and spectrum of BeO molecule under the electric field from different directions

    NARCIS (Netherlands)

    Jiang, M.; Guo, F. J.; Yan, A. Y.; Zhang, C. W.; Miao, F.

    2010-01-01

    Based on the density functional theory DFT/ B3LYP at 6-311g level, the ground states of BeO molecule are optimized. The effects of electric field on the bond length, the system energy, the charge distribution, the energy levels, the HOMO-LUMO gaps and the infrared spectrum of BeO molecule are

  11. Field survey for collection of information on the Pacific energy policy (China); Taiheiyo energy seisaku johonado genchi shushu chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The field survey for collection of synthetic information on petroleum substitution energy was made mostly in the electric power field in China. The capacity of hydroelectric power that China holds within is approximately 676 million kW, and the annual generated energy is presumed to be 5922.2 billion kWh. China is abundant in hydroelectric power source. Among these, the developmental capacities are 379 million kW and 1923.3 billion kWh, respectively, only about 15% of which has already been developed. The developmental capacity in the southwest area including the Yangtze River is about 60% of all the developmental capacity in China. Especially Sichuan Province is abundant in hydroelectric power. In the future, development is planned of large-scale power plants such as the Sanxia power plant. Further, for electrification of villages, the development of the wind power plant, in particular, out of small-scale hydroelectric power generation and new energy will be positively conducted, and wind power generation of 1 million kW is planned for 2000. With respect to energy conservation, reduction of 170 million ton/year equivalent in coal by 2000 is planned. The coal consumption at the sending end of coal power plant is planned to be reduced to 367g/kWh in 2000 while it was 417g/kWh in 1993. 27 refs., 48 figs., 72 tabs.

  12. Interaction of Gravitational field and Brans-Dicke field in R/W universe containing Dark Energy like fluid

    International Nuclear Information System (INIS)

    Singh, Kangujam Priyokumar; Dewri, Mukunda; Singh, Koijam Manihar

    2016-01-01

    On studying some new models of Robertson-Walker universes with a Brans-Dicke scalar field, it is found that most of these universes contain a dark energy like fluid which confirms the present scenario of the expansion of the universe. In one of the cases, the exact solution of the field equations gives a universe with a false vacuum, while in another it reduces to that of dust distribution in the Brans-Dicke cosmology when the cosmological constant is not in the picture. In one particular model it is found that the universe may undergo a Big Rip in the future, and thus it will be very interesting to investigate such models further. (paper)

  13. Electric-field-induced modification of the magnon energy, exchange interaction, and curie temperature of transition-metal thin films.

    Science.gov (United States)

    Oba, M; Nakamura, K; Akiyama, T; Ito, T; Weinert, M; Freeman, A J

    2015-03-13

    The electric-field-induced modification in the Curie temperature of prototypical transition-metal thin films with the perpendicular magnetic easy axis, a freestanding Fe(001) monolayer and a Co monolayer on Pt(111), is investigated by first-principles calculations of spin-spiral structures in an external electric field (E field). An applied E field is found to modify the magnon (spin-spiral formation) energy; the change arises from the E-field-induced screening charge density in the spin-spiral states due to p-d hybridizations. The Heisenberg exchange parameters obtained from the magnon energy suggest an E-field-induced modification of the Curie temperature, which is demonstrated via Monte Carlo simulations that take the magnetocrystalline anisotropy into account.

  14. The influence of mitigation on sage-grouse habitat selection within an energy development field.

    Directory of Open Access Journals (Sweden)

    Bradley C Fedy

    Full Text Available Growing global energy demands ensure the continued growth of energy development. Energy development in wildlife areas can significantly impact wildlife populations. Efforts to mitigate development impacts to wildlife are on-going, but the effectiveness of such efforts is seldom monitored or assessed. Greater sage-grouse (Centrocercus urophasianus are sensitive to energy development and likely serve as an effective umbrella species for other sagebrush-steppe obligate wildlife. We assessed the response of birds within an energy development area before and after the implementation of mitigation action. Additionally, we quantified changes in habitat distribution and abundance in pre- and post-mitigation landscapes. Sage-grouse avoidance of energy development at large spatial scales is well documented. We limited our research to directly within an energy development field in order to assess the influence of mitigation in close proximity to energy infrastructure. We used nest-location data (n = 488 within an energy development field to develop habitat selection models using logistic regression on data from 4 years of research prior to mitigation and for 4 years following the implementation of extensive mitigation efforts (e.g., decreased activity, buried powerlines. The post-mitigation habitat selection models indicated less avoidance of wells (well density β = 0.18 ± 0.08 than the pre-mitigation models (well density β = -0.09 ± 0.11. However, birds still avoided areas of high well density and nests were not found in areas with greater than 4 wells per km2 and the majority of nests (63% were located in areas with ≤ 1 well per km2. Several other model coefficients differed between the two time periods and indicated stronger selection for sagebrush (pre-mitigation β = 0.30 ± 0.09; post-mitigation β = 0.82 ± 0.08 and less avoidance of rugged terrain (pre-mitigation β = -0.35 ± 0.12; post-mitigation β = -0.05 ± 0.09. Mitigation efforts

  15. On the relation between the Einstein and the Komar expressions for the energy of the gravitational field

    International Nuclear Information System (INIS)

    Chrusciel, P.T.

    1983-09-01

    It is shown that the interpretation of the Einstein energy-momentum ''pseudo-tensor'', ''covariantized'' with the help of a background metric, as the energy-momentum tensor of the gravitational field with respect to a background field is consistent with a geometric Hamiltonian analysis. It is also shown that the von Freud superpotential and the Komar superpotential describe the dynamics of the gravitational field in different function spaces, subject to different boundary conditions. One can pass from one superpotential to the other by performing a Legendre transformation on the boundary. (author)

  16. Solar wind energy and electric field transfer to the Earth's magnetosphere VIA magnetopause reconnection

    International Nuclear Information System (INIS)

    Gonzalez, W.D.; Gonzalez, A.L.C.

    1981-01-01

    Some general expressions for the convection and parallel electric fields as well as for the energy transfer, due to magnetopause reconnection, are derived using a nose-reconnection model that takes into account the presence of the clefts. For the case of equal geomagnetic and magnetosheath field amplitudes, the expression for the power dissipated by the convection electric field reduces to the substorm parameter e widely discussed in the recent literature. This result suggests that magnetopause reconnection is defined at the nose with a tilted reconnection line, but that the convection electric field is related only to the dawn-dusk component of the reconnection electric field, as defined at high latitudes

  17. Magnetic-field and temperature dependence of the energy gap in InN nanobelt

    Directory of Open Access Journals (Sweden)

    K. Aravind

    2012-03-01

    Full Text Available We present tunneling measurements on an InN nanobelt which shows signatures of superconductivity. Superconducting transition takes place at temperature of 1.3K and the critical magnetic field is measured to be about 5.5kGs. The energy gap extrapolated to absolute temperature is about 110μeV. As the magnetic field is decreased to cross the critical magnetic field, the device shows a huge zero-bias magnetoresistance ratio of about 400%. This is attributed to the suppression of quasiparticle subgap tunneling in the presence of superconductivity. The measured magnetic-field and temperature dependence of the superconducting gap agree well with the reported dependences for conventional metallic superconductors.

  18. Using permanent magnets to boost the dipole field for the High-Energy LHC

    CERN Document Server

    Zimmermann, Frank

    2012-01-01

    The High-Energy LHC (HE-LHC) will be a new accelerator in the LHC tunnel based on novel dipole magnets, with a field up to 20 T, which are proposed to be realized by a hybrid-coil design, comprising blocks made from Nb- Ti, Nb$_{3}$Sn and HTS, respectively. Without the HTS the field would be only 15 T. In this note we propose and study the possibility of replacing the inner HTS layer by (weaker) permanent magnets that might contribute a field of 1-2 T, so that the final field would reach 16-17 T. Advantages would be the lower price of permanent magnets compared with HTS magnets and their availability in principle.

  19. Development of training courses in the field of nuclear energy

    International Nuclear Information System (INIS)

    Lee, Han Young; Seo, In Seok; Lee, Eui Jin; Seo, Kyung Won; Won, Jong Yeol; Nam, Jae Yeol

    1996-02-01

    This report describes the final results of D evelopment of training courses in the field of nuclear energy . The scope and contents are as follows : 1. to develop specialized nuclear training programs. 2. to collect and analyze foreign training programs and materials. 3. to develop foreign assisted training courses. 4. to develop interregional training courses for developing country trainees. and 5. to develop text materials for the implementation of training courses. 16 refs. (Author)

  20. Test of the rem-counter WENDI-II from Eberline in different energy-dispersed neutron fields

    International Nuclear Information System (INIS)

    Gutermuth, F.; Radon, T.; Fehrenbacher, G.; Siekmann, R.

    2004-03-01

    The neutron rem-counter WENDI-II from Eberline was tested in high-energy particle accelerator produced neutron fields. A radioactive 241 Am-Be(αn) source was used as a reference. The experimentally determined responses are compared to Monte-Carlo simulations of the response function done by R. H. Olsher et al. (2000). The energy spectra of the accelerator produced neutron fields were determined employing Monte-Carlo simulations, too. According to the simulations done by C. Birattari et al. (1998) and in this work these neutron fields exhibit large contributions to the ambient dose equivalent resulting from neutrons with kinetic energy of more than 20 MeV up to a few 100 MeV. The WENDI-II detector proved to show a response of approximately 3.10 9 pulses per Sievert ambient dose equivalent. Considering the experimental and statistical uncertainties the results are consistent with the assumption that the dose response of the WENDI-II reproduces quite accurately the function for the ambient dose equivalent of the ICRP 74

  1. An energy-stable convex splitting for the phase-field crystal equation

    KAUST Repository

    Vignal, P.; Dalcin, L.; Brown, D. L.; Collier, N.; Calo, V. M.

    2015-01-01

    Abstract The phase-field crystal equation, a parabolic, sixth-order and nonlinear partial differential equation, has generated considerable interest as a possible solution to problems arising in molecular dynamics. Nonetheless, solving this equation is not a trivial task, as energy dissipation and mass conservation need to be verified for the numerical solution to be valid. This work addresses these issues, and proposes a novel algorithm that guarantees mass conservation, unconditional energy stability and second-order accuracy in time. Numerical results validating our proofs are presented, and two and three dimensional simulations involving crystal growth are shown, highlighting the robustness of the method. © 2015 Elsevier Ltd.

  2. An energy-stable convex splitting for the phase-field crystal equation

    KAUST Repository

    Vignal, P.

    2015-10-01

    Abstract The phase-field crystal equation, a parabolic, sixth-order and nonlinear partial differential equation, has generated considerable interest as a possible solution to problems arising in molecular dynamics. Nonetheless, solving this equation is not a trivial task, as energy dissipation and mass conservation need to be verified for the numerical solution to be valid. This work addresses these issues, and proposes a novel algorithm that guarantees mass conservation, unconditional energy stability and second-order accuracy in time. Numerical results validating our proofs are presented, and two and three dimensional simulations involving crystal growth are shown, highlighting the robustness of the method. © 2015 Elsevier Ltd.

  3. Compatible, energy conserving, bounds preserving remap of hydrodynamic fields for an extended ALE scheme

    Science.gov (United States)

    Burton, D. E.; Morgan, N. R.; Charest, M. R. J.; Kenamond, M. A.; Fung, J.

    2018-02-01

    From the very origins of numerical hydrodynamics in the Lagrangian work of von Neumann and Richtmyer [83], the issue of total energy conservation as well as entropy production has been problematic. Because of well known problems with mesh deformation, Lagrangian schemes have evolved into Arbitrary Lagrangian-Eulerian (ALE) methods [39] that combine the best properties of Lagrangian and Eulerian methods. Energy issues have persisted for this class of methods. We believe that fundamental issues of energy conservation and entropy production in ALE require further examination. The context of the paper is an ALE scheme that is extended in the sense that it permits cyclic or periodic remap of data between grids of the same or differing connectivity. The principal design goals for a remap method then consist of total energy conservation, bounded internal energy, and compatibility of kinetic energy and momentum. We also have secondary objectives of limiting velocity and stress in a non-directional manner, keeping primitive variables monotone, and providing a higher than second order reconstruction of remapped variables. In particular, the new contributions fall into three categories associated with: energy conservation and entropy production, reconstruction and bounds preservation of scalar and tensor fields, and conservative remap of nonlinear fields. The paper presents a derivation of the methods, details of implementation, and numerical results for a number of test problems. The methods requires volume integration of polynomial functions in polytopal cells with planar facets, and the requisite expressions are derived for arbitrary order.

  4. Double unification of particles with fields and electricity with gravity in non-empty space of continuous complex energies

    Directory of Open Access Journals (Sweden)

    Bulyzhenkov Igor E.

    2016-01-01

    Full Text Available Non-empty space reading of Maxwell equations as local energy identities explains why a Coulomb field is carried rigidly by electrons in experiments. The analytical solution of the Poisson equation defines the sharp radial shape of charged elementary densities which are proportional to continuous densities of electric self-energy. Both Coulomb field and radial charge densities are free from energy divergences. Non-empty space of electrically charged mass-energy can be described by complex analytical densities resulting in real values for volume mass integrals and in imaginary values for volume charge integrals. Imaginary electric charges in the Newton gravitational law comply with real Coulomb forces. Unification of forces through complex charges rids them of radiation self-acceleration. Strong gravitational fields repeal probe bodies that might explainthe accelerated expansion of the dense Metagalaxy. Outward and inward spherical waves form the standing wave process within the radial carrier of complex energy.

  5. Field Evaluation of Advances in Energy-Efficiency Practices for Manufactured Homes

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E. [Advanced Residential Integrated Energy Solutions (ARIES) Collaboration, New York, NY (United States); Dentz, J. [Advanced Residential Integrated Energy Solutions (ARIES) Collaboration, New York, NY (United States); Ansanelli, E. [Advanced Residential Integrated Energy Solutions (ARIES) Collaboration, New York, NY (United States); Barker, G. [Advanced Residential Integrated Energy Solutions (ARIES) Collaboration, New York, NY (United States); Rath, P. [Advanced Residential Integrated Energy Solutions (ARIES) Collaboration, New York, NY (United States); Dadia, D. [Advanced Residential Integrated Energy Solutions (ARIES) Collaboration, New York, NY (United States)

    2016-03-01

    Three side-by-side lab houses were built, instrumented and monitored in an effort to determine through field testing and analysis the relative contributions of select technologies toward reducing energy use in new manufactured homes. The lab houses in Russellville, Alabama compared the performance of three homes built to varying levels of thermal integrity and HVAC equipment: a baseline HUD-code home equipped with an electric furnace and a split system air conditioner; an ENERGY STAR manufactured home with an enhanced thermal envelope and traditional split system heat pump; and a house designed to qualify for Zero Energy Ready Home designation with a ductless mini-split heat pump with transfer fan distribution system in place of the traditional duct system for distribution. Experiments were conducted in the lab houses to evaluate impact on energy and comfort of interior door position, window blind position and transfer fan operation. The report describes results of tracer gas and co-heating tests and presents calculation of the heat pump coefficient of performance for both the traditional heat pump and the ductless mini-split. A series of calibrated energy models was developed based on measured data and run in three locations in the Southeast to compare annual energy usage of the three homes.

  6. Læring mellem elever

    DEFF Research Database (Denmark)

    Georgsen, Marianne; Davidsen, Jacob

    2010-01-01

    I denne rapport præsenteres resultater fra følgeforskningen til projektet Læring gennem Bevægelse, som er gennemført på Søndervangskolen i Hammel i perioden august 2009 - maj 2010. Projektet er gennemført i samspil mellem lærere, it-vejleder, elever og skolens ledelse. Projektets overordnede formål...

  7. Merging Belief Propagation and the Mean Field Approximation: A Free Energy Approach

    DEFF Research Database (Denmark)

    Riegler, Erwin; Kirkelund, Gunvor Elisabeth; Manchón, Carles Navarro

    2013-01-01

    We present a joint message passing approach that combines belief propagation and the mean field approximation. Our analysis is based on the region-based free energy approximation method proposed by Yedidia et al. We show that the message passing fixed-point equations obtained with this combination...... correspond to stationary points of a constrained region-based free energy approximation. Moreover, we present a convergent implementation of these message passing fixed-point equations provided that the underlying factor graph fulfills certain technical conditions. In addition, we show how to include hard...

  8. An energy-stable time-integrator for phase-field models

    KAUST Repository

    Vignal, Philippe

    2016-12-27

    We introduce a provably energy-stable time-integration method for general classes of phase-field models with polynomial potentials. We demonstrate how Taylor series expansions of the nonlinear terms present in the partial differential equations of these models can lead to expressions that guarantee energy-stability implicitly, which are second-order accurate in time. The spatial discretization relies on a mixed finite element formulation and isogeometric analysis. We also propose an adaptive time-stepping discretization that relies on a first-order backward approximation to give an error-estimator. This error estimator is accurate, robust, and does not require the computation of extra solutions to estimate the error. This methodology can be applied to any second-order accurate time-integration scheme. We present numerical examples in two and three spatial dimensions, which confirm the stability and robustness of the method. The implementation of the numerical schemes is done in PetIGA, a high-performance isogeometric analysis framework.

  9. An energy-stable time-integrator for phase-field models

    KAUST Repository

    Vignal, Philippe; Collier, N.; Dalcin, Lisandro; Brown, D.L.; Calo, V.M.

    2016-01-01

    We introduce a provably energy-stable time-integration method for general classes of phase-field models with polynomial potentials. We demonstrate how Taylor series expansions of the nonlinear terms present in the partial differential equations of these models can lead to expressions that guarantee energy-stability implicitly, which are second-order accurate in time. The spatial discretization relies on a mixed finite element formulation and isogeometric analysis. We also propose an adaptive time-stepping discretization that relies on a first-order backward approximation to give an error-estimator. This error estimator is accurate, robust, and does not require the computation of extra solutions to estimate the error. This methodology can be applied to any second-order accurate time-integration scheme. We present numerical examples in two and three spatial dimensions, which confirm the stability and robustness of the method. The implementation of the numerical schemes is done in PetIGA, a high-performance isogeometric analysis framework.

  10. Nonlinear bound on unstable field energy in relativistic electron beams and plasmas

    International Nuclear Information System (INIS)

    Davidson, R.C.; Yoon, P.H.

    1989-01-01

    This paper makes use of Fowler's method [J. Math Phys. 4, 559 (1963)] to determine the nonlinear thermodynamic bound on field energy in unstable plasmas or electron beams in which the electrons are relativistic. Treating the electrons as the only active plasma component, the nonlinear Vlasov--Maxwell equations and the associated global conservation constraints are used to calculate the lowest upper bound on the field energy [ΔE-script/sub F/]/sub max/ that can evolve for the general initial electron distribution function f/sub b//sub / 0 equivalentf/sub b/(x,p,0). The results are applied to three choices of the initial distribution function f/sub b//sub / 0 . Two of the distribution functions have an inverted population in momentum p/sub perpendicular/ perpendicular to the magnetic field B 0 e/sub z/, and the third distribution function reduces to a bi-Maxwellian in the nonrelativistic limit. The lowest upper bound on the efficiency of radiation generation, eta/sub max/ = [ΔE-script/sub F/]/sub max//[V -1 ∫ d 3 x∫ d 3 p(γ-1)mc 2 f/sub b//sub / 0 ], is calculated numerically over a wide range of system parameters for varying degrees of initial anisotropy

  11. The galactic magnetic field and propagation of ultrahigh energy cosmic rays

    Czech Academy of Sciences Publication Activity Database

    Prouza, Michael; Šmída, Radomír

    2003-01-01

    Roč. 410, - (2003), s. 1-10 ISSN 0004-6361 R&D Projects: GA AV ČR IAA1010928; GA MŠk LN00A006; GA MŠk LA 134 Institutional research plan: CEZ:AV0Z1010920 Keywords : cosmic rays * magnetic fields * Galaxy Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.843, year: 2003

  12. Energy performance indicators of wastewater treatment: a field study with 17 Portuguese plants.

    Science.gov (United States)

    Silva, Catarina; Rosa, Maria João

    2015-01-01

    The energy costs usually represent the second largest part of the running costs of a wastewater treatment plant (WWTP). It is therefore crucial to increase the energy efficiency of these infrastructures and to implement energy management systems, where quantitative performance metrics, such as performance indicators (PIs), play a key role. This paper presents energy PIs which cover the unit energy consumption, production, net use from external sources and costs, and the results used to validate them and derive their reference values. The results of a field study with 17 Portuguese WWTPs (5-year period) were consistent with the results obtained through an international literature survey on the two key parcels of the energy balance--consumption and production. The unit energy consumption showed an overall inverse relation with the volume treated, and the reference values reflect this relation for trickling filters and for activated sludge systems (conventional, with coagulation/filtration (C/F) and with nitrification and C/F). The reference values of electrical energy production were derived from the methane generation potential (converted to electrical energy) and literature data, whereas those of energy net use were obtained by the difference between the energy consumption and production.

  13. The ground state energy of a bound polaron in the presence of a magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Zorkani, I [International Centre for Theoretical Physics, Trieste (Italy); Belhissi, R [Faculte des Sciences Dhar Mahraz, Fes (Morocco). Dept. de Physique

    1995-09-01

    A theoretical calculation for the ground state energy of a bound polaron as a function of the magnetic field is presented. The theory is based on a variational approach using a trial wave function proposed by Devreese et al. in the absence of the magnetic field. It was shown that his function is adequate for all electron - phonon coupling {alpha} and all parameter {gamma}{sub 0} which is the ratio between the L.O. phonon energy and the Colombian one. Analytical results are obtained in the weak coupling limit. (author). 27 refs, 4 figs, 1 tab.

  14. Field distribution of a source and energy absorption in an inhomogeneous magneto-active plasma

    International Nuclear Information System (INIS)

    Galushko, N.P.; Erokhin, N.S.; Moiseev, S.S.

    1975-01-01

    In the present paper the distribution of source fields in in a magnetoactive plasma is studied from the standpoint of the possibility of an effective SHF heating of an inhomogeneous plasma in both high (ωapproximatelyωsub(pe) and low (ωapproximatelyωsub(pi) frequency ranges, where ωsub(pe) and ωsub(pi) are the electron and ion plasma frequencies. The localization of the HF energy absorption regions in cold and hot plasma and the effect of plasma inhomogeneity and source dimensions on the absorption efficiency are investigated. The linear wave transformation in an inhomogeneous hot plasma is taken into consideration. Attention is paid to the difference between the region localization for collisional and non-collisional absorption. It has been shown that the HF energy dissipation in plasma particle collisions is localized in the region of thin jets going from the source; the radiation field has a sharp peak in this region. At the same time, non-collisional HF energy dissipation is spread over the plasma volume as a result of Cherenkov and cyclotron wave attenuation. The essential contribution to the source field from resonances due to standing wave excitation in an inhomogeneous plasma shell near the source is pointed out

  15. Energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in electric and magnetic fields

    International Nuclear Information System (INIS)

    Cruz, Philip Christopher S.; Bernardo, Reginald Christian S.; Esguerra, Jose Perico H.

    2017-01-01

    We calculate the energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in uniform electric and magnetic fields. Using separation of variables method and a change of independent variable, we show that the problem can be reduced to a one-dimensional Schrödinger equation for a periodic potential. The effects of varying the shape of the cross-section while keeping the same perimeter and the strengths of the electric and magnetic fields are investigated for elliptical, corrugated, and nearly-rectangular tubes with radial dimensions of the order of a nanometer. The geometric potential has minima at the angular positions where there is a significant amount of curvature. For the elliptical and corrugated tubes, it is shown that as the tube departs from the circular shape of cross-section the double-degeneracy between the energy levels is lifted. For the nearly-rectangular tube, it is shown that energy level crossings occur as the horizontal dimension of the tube is varied while keeping the same perimeter and radius of circular corners. The interplay between the curvature and the strength of the electric and magnetic fields determines the overall behavior of the energy levels. As the strength of the electric field increases, the overall potential gets skewed creating a potential well on the side corresponding to the more negative electric potential. The energy levels of the first few excited states approach more positive values while the ground state energy level approaches a more negative value. For large electric fields, all bound state energy levels tend to more negative values. The contribution of weak magnetic fields to the overall potential behaves in the same way as the electric field contribution but with its sign depending on the direction of the component of the momentum parallel to the cylindrical axis. Large magnetic fields lead to pairing of energy levels reminiscent of 2D Landau levels for the elliptical and nearly

  16. Energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Philip Christopher S., E-mail: pscruz1@up.edu.ph; Bernardo, Reginald Christian S., E-mail: rcbernardo@nip.upd.edu.ph; Esguerra, Jose Perico H., E-mail: jesguerra@nip.upd.edu.ph

    2017-04-15

    We calculate the energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in uniform electric and magnetic fields. Using separation of variables method and a change of independent variable, we show that the problem can be reduced to a one-dimensional Schrödinger equation for a periodic potential. The effects of varying the shape of the cross-section while keeping the same perimeter and the strengths of the electric and magnetic fields are investigated for elliptical, corrugated, and nearly-rectangular tubes with radial dimensions of the order of a nanometer. The geometric potential has minima at the angular positions where there is a significant amount of curvature. For the elliptical and corrugated tubes, it is shown that as the tube departs from the circular shape of cross-section the double-degeneracy between the energy levels is lifted. For the nearly-rectangular tube, it is shown that energy level crossings occur as the horizontal dimension of the tube is varied while keeping the same perimeter and radius of circular corners. The interplay between the curvature and the strength of the electric and magnetic fields determines the overall behavior of the energy levels. As the strength of the electric field increases, the overall potential gets skewed creating a potential well on the side corresponding to the more negative electric potential. The energy levels of the first few excited states approach more positive values while the ground state energy level approaches a more negative value. For large electric fields, all bound state energy levels tend to more negative values. The contribution of weak magnetic fields to the overall potential behaves in the same way as the electric field contribution but with its sign depending on the direction of the component of the momentum parallel to the cylindrical axis. Large magnetic fields lead to pairing of energy levels reminiscent of 2D Landau levels for the elliptical and nearly

  17. Laboratory constraints on chameleon dark energy and power-law fields

    OpenAIRE

    Steffen, Jason H.; Upadhye, Amol; Baumbaugh, Al; Chou, Aaron S.; Mazur, Peter O.; Tomlin, Ray; Weltman, Amanda; Wester, William

    2010-01-01

    We report results from the GammeV Chameleon Afterglow Search---a search for chameleon particles created via photon/chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of chameleon power-law models and dark energy models not previously explored. These results exclude five orders of magnitude in the coupling of chameleons to photons covering a range of four orders of magnitude in chameleon effective mass and, for individual chameleon models, exclude betw...

  18. Laboratory Constraints on Chameleon Dark Energy and Power-Law Fields

    International Nuclear Information System (INIS)

    Steffen, J. H.; Baumbaugh, A.; Chou, A. S.; Mazur, P. O.; Tomlin, R.; Wester, W.; Upadhye, A.; Weltman, A.

    2010-01-01

    We report results from a search for chameleon particles created via photon-chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of unexplored chameleon power-law and dark energy models. These results exclude 5 orders of magnitude in the coupling of chameleons to photons covering a range of 4 orders of magnitude in chameleon effective mass and, for individual models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter.

  19. Energy Levels and Spectral Lines of Li Atoms in White Dwarf Strength Magnetic Fields

    Science.gov (United States)

    Zhao, L. B.

    2018-04-01

    A theoretical approach based on B-splines has been developed to calculate atomic structures and discrete spectra of Li atoms in a strong magnetic field typical of magnetic white dwarf stars. Energy levels are presented for 20 electronic states with the symmetries 20+, 20‑, 2(‑1)+, 2(‑1)‑, and 2(‑2)+. The magnetic field strengths involved range from 0 to 2350 MG. The wavelengths and oscillator strengths for the electric dipole transitions relevant to these magnetized atomic states are reported. The current results are compared to the limited theoretical data in the literature. A good agreement has been found for the lower energy levels, but a significant discrepancy is clearly visible for the higher energy levels. The existing discrepancies of the wavelengths and oscillator strengths are also discussed. Our investigation shows that the spectrum data of magnetized Li atoms previously published are obviously far from meeting requirements of analyzing discrete atomic spectra of magnetic white dwarfs with lithium atmospheres.

  20. Enhanced Energy Density in Permanent Magnets using Controlled High Magnetic Field during Processing

    Energy Technology Data Exchange (ETDEWEB)

    Carter, William G [ORNL; Rios, Orlando [ORNL; Constantinides, Steven [ORNL

    2016-05-05

    This ORNL Manufacturing Demonstraction Facility (MDF) technical collaboration focused on the use of high magnetic field processing (>2Tesla) using energy efficient large bore superconducting magnet technology and high frequency electromagnetics to improve magnet performance and reduce the energy budget associated with Alnico thermal processing. Alnico, alloys containing Al, Ni, Co and Fe, represent a class of functional nanostructured alloys, and show the greatest potential for supplementing or replacing commercial Nd-based rare-earth alloy magnets.

  1. Stress-energy tensors for vector fields outside a static black hole

    International Nuclear Information System (INIS)

    Barrios, F.A.; Vaz, C.

    1989-01-01

    We obtain new, approximate stress-energy tensors to describe gauge fields in the neighborhood of a Schwarzschild black hole. We assume that the coefficient of ∇ 2 R in the trace anomaly is correctly given by ζ-function regularization. Our approximation differs from that of Page and of Brown and Ottewill and relies upon a new, improved ansatz for the form of the stress-energy tensor in the ultrastatic optical metric of the black hole. The Israel-Hartle-Hawking thermal tensor is constructed to be regular on the horizon and possess the correct asymptotic behavior. Our approximation of Unruh's tensor is likewise constructed to be regular on the future horizon and exhibit a luminosity which agrees with Page's numerically obtained value. Geometric expressions for the approximate tensors are given, and the approximate energy density of the thermal tensor on the horizon is compared with recent numerical estimates

  2. Dual-energy imaging in full-field digital mammography: a phantom study

    International Nuclear Information System (INIS)

    Taibi, A; Fabbri, S; Baldelli, P; Maggio, C di; Gennaro, G; Marziani, M; Tuffanelli, A; Gambaccini, M

    2003-01-01

    A dual-energy technique which employs the basis decomposition method is being investigated for application to digital mammography. A three-component phantom, made up of plexiglas, polyethylene and water, was doubly exposed with the full-field digital mammography system manufactured by General Electric. The 'low' and 'high' energy images were recorded with a Mo/Mo anode-filter combination and a Rh/Rh combination, respectively. The total dose was kept within the acceptable levels of conventional mammography. The first hybrid images obtained with the dual-energy algorithm are presented in comparison with a conventional radiograph of the phantom. Image-quality characteristics at contrast cancellation angles between plexiglas and water are discussed. Preliminary results show that a combination of a standard Mo-anode 28 kV radiograph with a Rh-anode 49 kV radiograph provides the best compromise between image-quality and dose in the hybrid image

  3. Laser-driven strong magnetostatic fields with applications to charged beam transport and magnetized high energy-density physics

    Science.gov (United States)

    Santos, Joao

    2017-10-01

    Powerful laser-plasma processes are explored to generate discharge currents of a few 100 kA in coil targets, yielding magnetostatic fields (B-fields) in the kTesla range. The B-fields are measured by proton-deflectometry and high-frequency bandwidth B-dot probes. According to our modeling, the quasi-static currents are provided from hot electron ejection from the laser-irradiated surface, accounting for the space charge neutralization and the plasma magnetization. The major control parameter is the laser irradiance Iλ2 . The B-fields ns-scale is long enough to magnetize secondary targets through resistive diffusion. We applied it in experiments of laser-generated relativistic electron transport into solid dielectric targets, yielding an unprecedented enhancement of a factor 5 on the energy-density flux at 60 µm depth, compared to unmagnetized transport conditions. These studies pave the ground for magnetized high-energy density physics investigations, related to laser-generated secondary sources of radiation and/or high-energy particles and their transport, to high-gain fusion energy schemes and to laboratory astrophysics. We acknowledge funding from French National Agency for Research (ANR), Grant TERRE ANR-2011-BS04-014, and from EUROfusion Consortium, European Union's Horizon 2020 research and innovation programme, Grant 633053.

  4. Measurement of ultra-low ion energy of decelerated ion beam using a deflecting electric field

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P.; Suwannakachorn, D.; Tippawan, U. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2015-12-15

    In investigation on ultra-low-energy ion bombardment effect on DNA, an ion beam deceleration lens was developed for high-quality ultra-low-energy ion beam. Measurement of the ion energy after deceleration was necessary to confirm the ion beam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the ion beam. The beam bending distance depended on the ion energy and was described and simulated. A system for the measurement of the ion beam energy was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect ion beam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the ion-beam deceleration lens inside the large chamber of the bioengineering vertical ion beam line. Moving the measurement rod across the decelerated ion beam enabled to obtain beam profiles, from which the beam bending distance could be known and the ion beam energy could be calculated. The measurement results were in good agreement with theoretical and simulated results.

  5. Nuclear energy 1986: Again in the field of tension of politics

    International Nuclear Information System (INIS)

    Broeders, I.; Wiese, H.W.; Karwat, H.; Schmitter, K.H.; Buchholz, H.; Thamm, G.; Hollmann, H.; Kalkoffen, F.

    1986-01-01

    The 1986 Jahrestagung Kerntechnik was held from April 8 to 10. The report first summarises the principal division lectures and the conference programme, and continues with brief accounts of various papers presented to the following divisions: 1) Reactor physics; 2) Thermodynamics and fluid dynamics; 3) Nuclear installations safety; 4) Fuel cycle and nuclear waste management; 5) Fuel elements and fuel materials; 6) Components and materials, quality assurance; 7) Construction and operation of nuclear installations; 8a) Fusion technology, 8b) Research and test reactors; 9) Energy systems and the power industry; 10) Atomic Energy Law, radiation protection and the Law on Environmental Protection Against Obnoxious Substances and related fields of law. (UA) [de

  6. Energy harvesting from dancing: for broadening in participation in STEM fields

    Science.gov (United States)

    Hamidi, Armita; Tadesse, Yonas

    2016-04-01

    Energy harvesting from structure vibration, human motion or environmental source has been the focus of researchers in the past few decades. This paper proposes a novel design that is suitable to harvest energy from human motions such as dancing or physical exercise and use the device to engage young students in Science, Technology, Engineering and Math (STEM) fields and outreach activities. The energy harvester (EH) device was designed for a dominant human operational frequency range of 1-5 Hz and it can be wearable by human. We proposed to incorporate different genres of music coupled with energy harvesting technologies for motivation and energy generation. Students will learn both science and art together, since the energy harvesting requires understanding basic physical phenomena and the art enables various physical movements that imparts the largest motion transfer to the EH device. Therefore, the systems are coupled to each other. Young people follow music updates more than robotics or energy harvesting researches. Most popular videos on YouTube and VEVO are viewed more than 100 million times. Perhaps, integrating the energy harvesting research with music or physical exercise might enhance students' engagement in science, and needs investigation. A multimodal energy harvester consisting of piezoelectric and electromagnetic subsystems, which can be wearable in the leg, is proposed in this study. Three piezoelectric cantilever beams having permanent magnets at the ends are connected to a base through a slip ring. Stationary electromagnetic coils are installed in the base and connected in series. Whenever the device is driven by any oscillation parallel to the base, the unbalanced rotor will rotate generating energy across the stationary coils in the base. In another case, if the device is driven by an oscillation perpendicular to the base, a stress will be induced within the cantilever beams generating energy across the piezoelectric materials.

  7. Hydration free energies of cyanide and hydroxide ions from molecular dynamics simulations with accurate force fields

    Science.gov (United States)

    Lee, M.W.; Meuwly, M.

    2013-01-01

    The evaluation of hydration free energies is a sensitive test to assess force fields used in atomistic simulations. We showed recently that the vibrational relaxation times, 1D- and 2D-infrared spectroscopies for CN(-) in water can be quantitatively described from molecular dynamics (MD) simulations with multipolar force fields and slightly enlarged van der Waals radii for the C- and N-atoms. To validate such an approach, the present work investigates the solvation free energy of cyanide in water using MD simulations with accurate multipolar electrostatics. It is found that larger van der Waals radii are indeed necessary to obtain results close to the experimental values when a multipolar force field is used. For CN(-), the van der Waals ranges refined in our previous work yield hydration free energy between -72.0 and -77.2 kcal mol(-1), which is in excellent agreement with the experimental data. In addition to the cyanide ion, we also study the hydroxide ion to show that the method used here is readily applicable to similar systems. Hydration free energies are found to sensitively depend on the intermolecular interactions, while bonded interactions are less important, as expected. We also investigate in the present work the possibility of applying the multipolar force field in scoring trajectories generated using computationally inexpensive methods, which should be useful in broader parametrization studies with reduced computational resources, as scoring is much faster than the generation of the trajectories.

  8. Electric field studies of a 2 MeV electrostatic energy analyzer

    International Nuclear Information System (INIS)

    McLaren, P.E.; Connor, K.A.; Lewis, J.F.; Hickok, R.L.; Crowley, T.P.; Schatz, J.G.; Vilardi, G.H.

    1990-01-01

    An energy analyzer based on the Proca and Green parallel-plate design is being developed for use with the 2 MeV heavy ion beam probe on TEXT. In a departure from the conventional configuration, guard ring electrodes will not be used. Instead, a shaped top plate will provide for comparable, or improved, uniformity of the analyzer electric field region. To quantify this effect, and to characterize the electrostatic field, numerical solution methods have been utilized. Simulations have included effects of top plate shape, wire screens, vacuum chamber design, and dielectric support structures. The modeling has permitted us to design an analyzer electrode structure that is an integral part of a uniquely shaped vacuum vessel. The design electric field is 20 kV/cm with less than 1% error in uniformity within the parallel plate region. To examine the electric field structure experimentally, a quarter-scale prototype analyzer has been constructed and tested. The electric field characteristics are examined by varying the path of a heavy ion beam through the analyzer and examining the resulting analyzer performance. A simulated vacuum wall can be positioned to examine the effects of different vessel configurations and to determine the sensitivity of the analyzer to this boundary condition. The experimental results show excellent agreement with the numerically predicted fields and confirm the validity of the shaped top plate electrode concept

  9. Laser-driven strong magnetostatic fields with applications to charged beam transport and magnetized high energy-density physics

    Science.gov (United States)

    Santos, J. J.; Bailly-Grandvaux, M.; Ehret, M.; Arefiev, A. V.; Batani, D.; Beg, F. N.; Calisti, A.; Ferri, S.; Florido, R.; Forestier-Colleoni, P.; Fujioka, S.; Gigosos, M. A.; Giuffrida, L.; Gremillet, L.; Honrubia, J. J.; Kojima, S.; Korneev, Ph.; Law, K. F. F.; Marquès, J.-R.; Morace, A.; Mossé, C.; Peyrusse, O.; Rose, S.; Roth, M.; Sakata, S.; Schaumann, G.; Suzuki-Vidal, F.; Tikhonchuk, V. T.; Toncian, T.; Woolsey, N.; Zhang, Z.

    2018-05-01

    Powerful nanosecond laser-plasma processes are explored to generate discharge currents of a few 100 kA in coil targets, yielding magnetostatic fields (B-fields) in excess of 0.5 kT. The quasi-static currents are provided from hot electron ejection from the laser-irradiated surface. According to our model, which describes the evolution of the discharge current, the major control parameter is the laser irradiance Ilasλlas2 . The space-time evolution of the B-fields is experimentally characterized by high-frequency bandwidth B-dot probes and proton-deflectometry measurements. The magnetic pulses, of ns-scale, are long enough to magnetize secondary targets through resistive diffusion. We applied it in experiments of laser-generated relativistic electron transport through solid dielectric targets, yielding an unprecedented 5-fold enhancement of the energy-density flux at 60 μm depth, compared to unmagnetized transport conditions. These studies pave the ground for magnetized high-energy density physics investigations, related to laser-generated secondary sources of radiation and/or high-energy particles and their transport, to high-gain fusion energy schemes, and to laboratory astrophysics.

  10. Gauge-invariant expectation values of the energy of a molecule in an electromagnetic field

    International Nuclear Information System (INIS)

    Mandal, Anirban; Hunt, Katharine L. C.

    2016-01-01

    In this paper, we show that the full Hamiltonian for a molecule in an electromagnetic field can be separated into a molecular Hamiltonian and a field Hamiltonian, both with gauge-invariant expectation values. The expectation value of the molecular Hamiltonian gives physically meaningful results for the energy of a molecule in a time-dependent applied field. In contrast, the usual partitioning of the full Hamiltonian into molecular and field terms introduces an arbitrary gauge-dependent potential into the molecular Hamiltonian and leaves a gauge-dependent form of the Hamiltonian for the field. With the usual partitioning of the Hamiltonian, this same problem of gauge dependence arises even in the absence of an applied field, as we show explicitly by considering a gauge transformation from zero applied field and zero external potentials to zero applied field, but non-zero external vector and scalar potentials. We resolve this problem and also remove the gauge dependence from the Hamiltonian for a molecule in a non-zero applied field and from the field Hamiltonian, by repartitioning the full Hamiltonian. It is possible to remove the gauge dependence because the interaction of the molecular charges with the gauge potential cancels identically with a gauge-dependent term in the usual form of the field Hamiltonian. We treat the electromagnetic field classically and treat the molecule quantum mechanically, but nonrelativistically. Our derivation starts from the Lagrangian for a set of charged particles and an electromagnetic field, with the particle coordinates, the vector potential, the scalar potential, and their time derivatives treated as the variables in the Lagrangian. We construct the full Hamiltonian using a Lagrange multiplier method originally suggested by Dirac, partition this Hamiltonian into a molecular term H m and a field term H f , and show that both H m and H f have gauge-independent expectation values. Any gauge may be chosen for the calculations; but

  11. Energy spectrum of two-dimensional tight-binding electrons in a spatially varying magnetic field

    International Nuclear Information System (INIS)

    Oh, G.Y.; Lee, M.H.

    1996-01-01

    The electronic energy spectrum of a two-dimensional lattice in a spatially varying magnetic field is studied within the framework of the tight-binding model by using the scheme of the transfer matrix. It is found that, in comparison with the case of a uniform magnetic field, the energy spectrum exhibits more complicated behavior; band broadening (or gap closing) and band splitting (or gap opening) occur depending on characteristic parameters of the lattice. The origin of these phenomena lies in the existence of direct touching and indirect overlapping between neighboring subbands. Dependence of direct touching and indirect overlapping, and thus the electronic band structure together with the density of states, on characteristic parameters of the lattice is elucidated in detail. copyright 1996 The American Physical Society

  12. A Study of the Magnetic Dipole Field of LEP during the 1995 Energy Scan

    CERN Document Server

    Dehning, Bernd; Geitz, M A

    1996-01-01

    In preparation for the 1995 LEP energy scan additional instrumentation was installed in two tunnel dipoles to monitor the time evolution of the magnetic field during experimental fills. Significant increase of the bending field superimposed by day-time dependent fluctuations on a minute time scale were revealed. These unexpected features could be correlated with earth currents captured by the LEP vacuum chamber and the ground cable. The currents are produced in particular by trains circulating in the Geneva area. This study presents a summary of our understanding of the LEP dipole field.

  13. Magnet field design considerations for a high energy superconducting cyclotron

    International Nuclear Information System (INIS)

    Botman, J.I.M.; Craddock, M.K.; Kost, C.J.; Richardson, J.R.

    1983-08-01

    This paper reports the pole shape designs for a two stage superconducting isochronous cyclotron combination (CANUCK) to accelerate 100 μA proton beams to 15 GeV. The pole shape of the 15 sectors of the first stage 3.5 GeV proton cyclotron provides isochronism over the full energy range and a constant axial tune over all but the lowest energies. Progress on the pole design of the 42 sector 15 GeV second stage is also reported. The magnetic fields are computed from the current distribution of the superconducting coils and the infinitely thin current sheets simulating the fully saturated poles. A least squares method is used to minimize deviations from isochronism by adjusting the size of various elemental shim coils placed around the main coil. The method to obtain the desired axial tune is described

  14. Large area APDs for low energy X-ray detection in intense magnetic fields

    International Nuclear Information System (INIS)

    Boucher, M.; Huot, O.; Knowles, P.E.; Ludhova, L.; Mulhauser, F.; Schaller, L.A.; Conde, C.A.N.; Santos, J.M.F. dos; Fernandes, L.M.P.; Veloso, J.F.C.A.; Kottmann, F.; Antognini, A.; Pohl, R.; Taqqu, D.

    2003-01-01

    An experiment to measure the energy difference between the 2S-2P atomic levels (Lamb shift) in muonic hydrogen is being prepared at PSI. Since the energy levels of muonic hydrogen are a factor of 186 more energetic than those of hydrogen, according to the ratio of reduced masses, the transitions lie in the soft X-ray region. The experiment needs long-lived muonic hydrogen in the 2S state. This is achieved by stopping a low energy muon beam in a small volume of low pressure hydrogen in a 5 T magnetic field. A pulsed beam from a tunable laser induces the 2S-2P transition and the 1.9 keV X-ray photons resulting from the 2P-1S deexcitation will be detected. Measuring the coincidences between the laser pulse and the X-ray as a function of the laser wavelength allows us to determine the Lamb shift. In this presentation we will discuss the perspectives of using large area avalanche photodiodes for the direct detection of the X-rays. Compared to gaseous detectors, they are more compact and simpler in operation. They are also insensitive to magnetic fields

  15. Large area APDs for low energy X-ray detection in intense magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, M.; Huot, O.; Knowles, P.E.; Ludhova, L.; Mulhauser, F. E-mail: francoise.mulhauser@unifr.ch; Schaller, L.A.; Conde, C.A.N.; Santos, J.M.F. dos; Fernandes, L.M.P.; Veloso, J.F.C.A.; Kottmann, F.; Antognini, A.; Pohl, R.; Taqqu, D

    2003-06-01

    An experiment to measure the energy difference between the 2S-2P atomic levels (Lamb shift) in muonic hydrogen is being prepared at PSI. Since the energy levels of muonic hydrogen are a factor of 186 more energetic than those of hydrogen, according to the ratio of reduced masses, the transitions lie in the soft X-ray region. The experiment needs long-lived muonic hydrogen in the 2S state. This is achieved by stopping a low energy muon beam in a small volume of low pressure hydrogen in a 5 T magnetic field. A pulsed beam from a tunable laser induces the 2S-2P transition and the 1.9 keV X-ray photons resulting from the 2P-1S deexcitation will be detected. Measuring the coincidences between the laser pulse and the X-ray as a function of the laser wavelength allows us to determine the Lamb shift. In this presentation we will discuss the perspectives of using large area avalanche photodiodes for the direct detection of the X-rays. Compared to gaseous detectors, they are more compact and simpler in operation. They are also insensitive to magnetic fields.

  16. Modeling surface energy fluxes from a patchwork of fields with different soils and crops

    Science.gov (United States)

    Klein, Christian; Thieme, Christoph; Heinlein, Florian; Priesack, Eckart

    2017-04-01

    Agroecosystems are a dominant terrestrial land-use on planet earth and cover about 36% of the ice-free surface (12% pasture, 26% agriculture) [Foley2011]. Within this land use type, management practices vary strongly due to climate, cultural preferences, degree of industrialization, soil properties, crop rotations, field sizes, degree of land use sustainability, water availability, sowing and harvest dates, tillage, etc. These management practices influence abiotic environmental factors like water flow and heat transport within the ecosystem leading to changes of land surface fluxes. The relevance of vegetation (e.g. crops), ground cover, and soil properties to the moisture and energy exchanges between the land surface and the atmosphere is well known [McPherson 2007], but the impact of vegetation growth dynamics on energy fluxes is only partly understood [Gayler et al. 2014]. Thus, the structure of turbulence and the albedo evolve during the cropping period and large variations of heat can be measured on the field scale [Aubinet2012]. One issue of local distributed mixture of different land use is the measurement process which makes it challenging to evaluate simulations. Unfortunately, for meteorological flux-measurements like the Flux-Gradient or the Eddy Covariance (EC) method, comparability with simulations only exists in the ideal case, where fields have to be completely uniform in land use and flat within the reach of the footprint. Then a model with one specific land use would have the same underlying source area as the measurement. An elegant method to avoid the shortcoming of grid cell resolution is the so called mixed approach, which was recently implemented into the ecosystem model framework Expert-N [Biernath et al. 2013]. The aim of this study was to analyze the impact of the characteristics of five managed field plots, planted with winter wheat, potato and maize on the near surface soil moistures and on the near surface energy flux exchanges of the

  17. Laser field effects on the transport phenomena: Energy loss and stopping power

    International Nuclear Information System (INIS)

    Torres Silva, H.; Sakanaka, P.H.

    1990-01-01

    The energy loss method has been applied to a large variety of transport problems in optics, solid-state and fusion research. In these papers, however, the transport equations were linearized, so there are no multiphoton interaction. On the other hand, Bivona et al. (1982) [2] have shown that, for a one-component plasma, the strong field effects would be only of academic interest. On the basis of the center of mass approach [3], a generalization of the energy loss rate which is in accordance with the recent results of Arista et al. (1989) [4] is obtained. (Author)

  18. Response study of fission track detectors using two different moderator designs in a high-energy radiation field

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, S. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)], E-mail: Sabine.Mayer@psi.ch; Boschung, M.; Fiechtner, A. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Fuerstner, M. [CERN, CH-1211 Geneva 23 (Switzerland); Wernli, C. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2008-02-15

    Fission track detectors in the center of moderating spheres are routinely used to measure the ambient dose equivalent due to neutrons in the environmental dosimetry at Paul Scherrer Institut (PSI). Originally, the system was designed to cope with neutrons from skyshine effects. Later, the system was also adapted behind the shielding of PSI's accelerators. Nowadays, as a consequence of continuously upgrading accelerator energies and intensities, the neutron energy behind thick shielding can range from fractions of eV to about 1 GeV (e.g. at CERN). For this reason a measurement campaign in a high-energy stray radiation field at CERN's High-Energy Reference Field Facility (CERF) was initiated to study and compare the response of the already existing detector-moderator configuration and a new design, the 'GSI ball'. Employing an additional lead layer in a moderator sphere of 32.5 cm diameter, the GSI ball was primarily designed for the use with thermoluminescent based dosimeters in its center in order to optimize the response for the measurement of H*(10) to higher neutron energies. In this work, the measurement results for fission track detectors using two different radiator materials in the PSI and the GSI moderator are presented. Based on these studies, on the one hand, field calibration factors for the use in presumably similar high-energy fields around accelerators could be deduced. On the other hand, it could be shown that there is no need to replace the established PSI moderator by the GSI moderator since the combination of fission track detector and GSI moderator does not result in a significant sensitivity improvement.

  19. Response study of fission track detectors using two different moderator designs in a high-energy radiation field

    International Nuclear Information System (INIS)

    Mayer, S.; Boschung, M.; Fiechtner, A.; Fuerstner, M.; Wernli, C.

    2008-01-01

    Fission track detectors in the center of moderating spheres are routinely used to measure the ambient dose equivalent due to neutrons in the environmental dosimetry at Paul Scherrer Institut (PSI). Originally, the system was designed to cope with neutrons from skyshine effects. Later, the system was also adapted behind the shielding of PSI's accelerators. Nowadays, as a consequence of continuously upgrading accelerator energies and intensities, the neutron energy behind thick shielding can range from fractions of eV to about 1 GeV (e.g. at CERN). For this reason a measurement campaign in a high-energy stray radiation field at CERN's High-Energy Reference Field Facility (CERF) was initiated to study and compare the response of the already existing detector-moderator configuration and a new design, the 'GSI ball'. Employing an additional lead layer in a moderator sphere of 32.5 cm diameter, the GSI ball was primarily designed for the use with thermoluminescent based dosimeters in its center in order to optimize the response for the measurement of H*(10) to higher neutron energies. In this work, the measurement results for fission track detectors using two different radiator materials in the PSI and the GSI moderator are presented. Based on these studies, on the one hand, field calibration factors for the use in presumably similar high-energy fields around accelerators could be deduced. On the other hand, it could be shown that there is no need to replace the established PSI moderator by the GSI moderator since the combination of fission track detector and GSI moderator does not result in a significant sensitivity improvement

  20. ION KINETIC ENERGY CONSERVATION AND MAGNETIC FIELD STRENGTH CONSTANCY IN MULTI-FLUID SOLAR WIND ALFVÉNIC TURBULENCE

    Energy Technology Data Exchange (ETDEWEB)

    Matteini, L.; Horbury, T. S.; Schwartz, S. J. [The Blackett Laboratory, Imperial College London, SW7 2AZ (United Kingdom); Pantellini, F. [LESIA, Observatoire de Paris, CNRS, UPMC, Universit Paris-Diderot, 5 Place Jules Janssen, F-92195 Meudon (France); Velli, M. [Department of Earth, Planetary, and Space Sciences, UCLA, California (United States)

    2015-03-20

    We investigate the properties of plasma fluid motion in the large-amplitude, low-frequency fluctuations of highly Alfvénic fast solar wind. We show that protons locally conserve total kinetic energy when observed from an effective frame of reference comoving with the fluctuations. For typical properties of the fast wind, this frame can be reasonably identified by alpha particles which, due to their drift with respect to protons at about the Alfvén speed along the magnetic field, do not partake in the fluid low-frequency fluctuations. Using their velocity to transform the proton velocity into the frame of Alfvénic turbulence, we demonstrate that the resulting plasma motion is characterized by a constant absolute value of the velocity, zero electric fields, and aligned velocity and magnetic field vectors as expected for unidirectional Alfvénic fluctuations in equilibrium. We propose that this constraint, via the correlation between velocity and magnetic field in Alfvénic turbulence, is the origin of the observed constancy of the magnetic field; while the constant velocity corresponding to constant energy can only be observed in the frame of the fluctuations, the corresponding constant total magnetic field, invariant for Galilean transformations, remains the observational signature in the spacecraft frame of the constant total energy in the Alfvén turbulence frame.

  1. Energy dependence of an ionization chamber with parallel plates in standard gamma and x-radiation fields

    International Nuclear Information System (INIS)

    Batistella, M.A.; Caldas, L.V.E.

    1988-09-01

    The characteristics of low energy X-radiation standard fields were determined and the energy dependence of a ionization chamber of the superficial type, with parallel plates and fixed volume, normally utilized in the dosimetry at the Radiotherapy level was studied. The possibility of adaptation of this chamber type for use in gamma radiation dosimetry was verified. Different thickness Lucite build-up caps, from 2.0 up to 5.5 mm, were produced and tested in 60 Co and 137 Cs gamma radiation fields. This type of detector, with the adequate build-up cap, presented a performance comparable to that of the thimble type ionization chamber. It was concluded that it is not necessary to use different kinds of chambers for each high and mean energy interval. The superficial chamber, specially produced to detect low energy X-radiation, may be adapted to detect gamma radiation. (author) [pt

  2. Earthworms influenced by reduced tillage, conventional tillage and energy forest in Swedish agricultural field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lagerloef, Jan (SLU, Department of Ecology, Swedish University of Agricultural Sciences, Uppsala (Sweden)), Email: Jan.Lagerlof@ekol.slu.se; Paalsson, Olof; Arvidsson, Johan (SLU, Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala (Sweden))

    2012-03-15

    We compared earthworm density, depth distribution and species composition in three soil cultivation experiments including the treatments ploughless tillage and mouldboard ploughing. Sampling was done in September 2005 and for one experiment also in 1994. By yearly sampling 1995-2005, earthworms in an energy forest of Salix viminalis were compared with those in an adjacent arable field. Sampling method was digging of soil blocks and hand sorting and formalin sampling in one cultivation experiment. Both methods were used in the energy forest and arable land comparison. In two soil cultivation experiments, highest abundances or biomass were found in ploughless tillage. Earthworm density was higher in the upper 10 cm, especially in the ploughless tillage. Earthworm density was significantly higher in the energy forest than in the arable field. Formalin sampling revealed c. 36% of the earthworm numbers found by digging in the energy forest and gave almost no earthworms in the arable field. In all treatments with soil cultivation, species living and feeding in the rhizosphere and soil dominated. One such species, Allolobophora chlorotica, was more abundant under mouldboard ploughing than ploughless tillage. Lumbricus terrestris, browsing on the surface and producing deep vertical burrows, was more common in the ploughless tillage. Species living and feeding close to the soil surface were almost only found in the energy forest, which had not been soil cultivated since 1984. The findings support earlier studies pointing out possibilities to encourage earthworms by reduced soil cultivation. This is one of the first published studies that followed earthworm populations in an energy forest plantation during several years. Explanation of earthworm reactions to management and environmental impacts should be done with consideration of the ecology of species or species groups. Earthworm sampling by formalin must always be interpreted with caution and calibrated by digging and

  3. Using Magnetic Fields to Create and Control High Energy Density Matter

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Mark [Sandia National Laboratory

    2012-05-09

    The recently refurbished Z facility at Sandia National Laboratories is the world’s largest pulsed power driver. Z can efficiently deliver currents as large as 26 Million Amperes to centimeter scale loads. These large currents create large magnetic fields that, in turn, create very large pressures in conducting materials. These very large pressures have been used to create unique conditions for high energy density science experiments for a variety of applications. Recently, we have been exploring the use of very strong magnetic fields to significantly relax the requirements for achieving inertial confinement fusion self heating1. The magnetized liner inertial fusion (MagLIF) concept relies on a cylindrically imploding liner, an axial magnetic field, and a laser heated fuel region. We hope to achieve significant fusion yield on the Z facility with this concept. Initial experiments assessing the growth of the Magneto-Rayleigh Taylor instability are promising and recent calculational work has identified an approach to achieving high gain with this concept.

  4. MODEL OF INTEGRATED VALUE OF PROJECTS IN THE FIELD OF ALTERNATIVE ENERGY

    Directory of Open Access Journals (Sweden)

    Наталія Ігорівна БОРИСОВА

    2015-05-01

    Full Text Available Development of alternative energy sources requires the implementation of complex problems, the solution of which is necessary to apply the project approach. The uniqueness of alternative energy projects (AEP necessitates individual approach to evaluating the effectiveness of each. The paper contains the results of the project management features's analysis in the field of alternative energy, determining the values and developing of the value management integrated conceptual model of AEP. In assessing the effectiveness of AEP considered the socio-economic and commercial aspects. Value management integrated conceptual model of AEP was obtained by combining the classical model of the project management goals with the project values model "Five "E" and two "A". The classical model of the project management goals have been complemented with risk parameters.

  5. Testing electric field models using ring current ion energy spectra from the Equator-S ion composition (ESIC instrument

    Directory of Open Access Journals (Sweden)

    L. M. Kistler

    Full Text Available During the main and early recovery phase of a geomagnetic storm on February 18, 1998, the Equator-S ion composition instrument (ESIC observed spectral features which typically represent the differences in loss along the drift path in the energy range (5–15 keV/e where the drift changes from being E × B dominated to being gradient and curvature drift dominated. We compare the expected energy spectra modeled using a Volland-Stern electric field and a Weimer electric field, assuming charge exchange along the drift path, with the observed energy spectra for H+ and O+. We find that using the Weimer electric field gives much better agreement with the spectral features, and with the observed losses. Neither model, however, accurately predicts the energies of the observed minima.

    Key words. Magnetospheric physics (energetic particles trapped; plasma convection; storms and substorms

  6. The effect of energy spectrum change on DNA damage in and out of field in 10-MV clinical photon beams.

    Science.gov (United States)

    Ezzati, A O; Xiao, Y; Sohrabpour, M; Studenski, M T

    2015-01-01

    The aim of this study was to quantify the DNA damage induced in a clinical megavoltage photon beam at various depths in and out of the field. MCNPX was used to simulate 10 × 10 and 20 × 20 cm(2) 10-MV photon beams from a clinical linear accelerator. Photon and electron spectra were collected in a water phantom at depths of 2.5, 12.5 and 22.5 cm on the central axis and at off-axis points out to 10 cm. These spectra were used as an input to a validated microdosimetric Monte Carlo code, MCDS, to calculate the RBE of induced DSB in DNA at points in and out of the primary radiation field at three depths. There was an observable difference in the energy spectra for photons and electrons for points in the primary radiation field and those points out of field. In the out-of-field region, the mean energy for the photon and electron spectra decreased by a factor of about six and three from the in-field mean energy, respectively. Despite the differences in spectra and mean energy, the change in RBE was photon and electron spectra, these changes do not correlate with a change in RBE in a clinical MV photon beam as the electron spectra are dominated by electrons with energies >20 keV.

  7. METHOD OF CALCULATION OF THE NON-STATIONARY TEMPERATURE FIELD INSIDE OF THERMAL PACKED BED ENERGY STORAGE

    Directory of Open Access Journals (Sweden)

    Ermuratschii V.V.

    2014-04-01

    Full Text Available e paper presents a method of the approximate calculation of the non-stationary temperature field inside of thermal packed bed energy storages with feasible and latent heat. Applying thermoelectric models and computational methods in electrical engineering, the task of computing non-stationary heat transfer is resolved with respect to third type boundary conditions without applying differential equations of the heat transfer. For sub-volumes of the energy storage the method is executed iteratively in spatiotemporal domain. Single-body heating is modeled for each sub-volume, and modeling conditions are assumed to be identical for remained bod-ies, located in the same sub-volume. For each iteration step the boundary conditions will be represented by re-sults at the previous step. The fulfillment of the first law of thermodynamics for system “energy storage - body” is obtained by the iterative search of the mean temperature of the energy storage. Under variable boundary con-ditions the proposed method maybe applied to calculating temperature field inside of energy storages with packed beds consisted of solid material, liquid and phase-change material. The method may also be employed to compute transient, power and performance characteristics of packed bed energy storages.

  8. The response of different types of TL lithium fluoride detectors to high-energy mixed radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Obryk, B. [Institute of Nuclear Physics PAN (IFJ), ul. Radzikowskiego 152, 31-342 Krakow (Poland)], E-mail: barbara.obryk@ifj.edu.pl; Bilski, P.; Budzanowski, M. [Institute of Nuclear Physics PAN (IFJ), ul. Radzikowskiego 152, 31-342 Krakow (Poland); Fuerstner, M. [CERN - European Organization for Nuclear Research, 1211 Geneva 23 (Switzerland); Ilgner, C. [CERN - European Organization for Nuclear Research, 1211 Geneva 23 (Switzerland) and University of Dortmund, Dortmund (Germany); Jaquenod, F. [Ecole d' Ingenieurs de Geneve, Geneva (Switzerland); Olko, P.; Puchalska, M. [Institute of Nuclear Physics PAN (IFJ), ul. Radzikowskiego 152, 31-342 Krakow (Poland); Vincke, H. [CERN - European Organization for Nuclear Research, 1211 Geneva 23 (Switzerland)

    2008-02-15

    Thermoluminescent (TL) dosimeters are routinely used to monitor absorbed doses in many kinds of radiation fields which contain photons, electrons and neutrons. However, TLDs are mainly calibrated to photon sources. We studied the response of TLDs to complex secondary fields arising during the operation of high-energy accelerators (e.g. the Large Hadron Collider (LHC) at CERN). The experiments were conducted at the CERN-EU high-energy reference field facility (CERF). Six different LiF-based TLDs (MTS-N, MTS-7, MTS-6, MCP-N, MCP-7, MCP-6) were exposed to various secondary CERF's fields (both for high and low doses), by placing them at various positions: at the target and concrete top and side positions. For the experiment at the target the corresponding Monte Carlo calculations were also carried out using the FLUKA transport code and compared with experimental results. In addition, alanine dosimeters were used as an independent reference. The results show that TLDs are well suited for monitoring radiation fields around the LHC. Nevertheless, further investigations are required, some of which are in progress.

  9. Note: Laser-cut molybdenum grids for a retarding field energy analyzer

    Science.gov (United States)

    Landheer, K.; Kobelev, A. A.; Smirnov, A. S.; Bosman, J.; Deelen, S.; Rossewij, M.; de Waal, A. C.; Poulios, I.; Benschop, A. F.; Schropp, R. E. I.; Rath, J. K.

    2017-06-01

    A retarding field energy analyzer (RFEA) with grids created by laser-cutting a honeycomb mesh in a 50 μm thick molybdenum foil is presented. The flat grids span an area of 1 cm2 and have high transmission (20 μm wide walls between 150 μm wide meshes). The molybdenum grids were tested in a 3-grid RFEA configuration with an analyzer depth of 0.87 mm.

  10. Forenklingens fire F'er

    DEFF Research Database (Denmark)

    Bentzen, Tina Øllgaard

    2017-01-01

    At fjerne styring er det, man ofte forbinder med afbureaukratisering, men det er ikke tilstrækkeligt, når man vil gå fra flotte ambitioner til en styring, som reelt opleves enklere. For at forenkle må man også forandre, forankre og fastholde styring, og det må ske i et samspil mellem de aktører, ...

  11. Kognition og uendelighed

    DEFF Research Database (Denmark)

    Kaspersen, Peter

    2010-01-01

    Afrapportering af et tværfagligt undervisningsforløb på Midtsjællands Gymnasieskoler i regi af Danske Science Gymnasier. Formålet med forløbet var at undersøge i hvilken udstrækning man kan realisere ambitionerne om at gennemføre faglige samspil mellem studieretningsfag ved både at have et fælles...

  12. Mikrobiologisk Sikker Sænkning af Varmtvandstemperaturen

    DEFF Research Database (Denmark)

    Gottlieb, Frederik; Larsen, Henry

    2015-01-01

    fremløbstemperaturen. En forretningsmodel kunne for eksempel være at følge Viborg Fjernvarmes eksempel og indgå i lejeordninger i samspil med fjernvarmeselskaber, som påtænker at lave løsninger med lavtemperaturfjernvarme i områder, hvor der er bygninger med krav til Legionella. Dette er ikke en lavthængende frugt...

  13. The CERN-EU high-energy Reference Field (CERF) facility: applications and latest developments

    Science.gov (United States)

    Silari, Marco; Pozzi, Fabio

    2017-09-01

    The CERF facility at CERN provides an almost unique high-energy workplace reference radiation field for the calibration and test of radiation protection instrumentation employed at high-energy accelerator facilities and for aircraft and space dosimetry. This paper describes the main features of the facility and supplies a non-exhaustive list of recent (as of 2005) applications for which CERF is used. Upgrade work started in 2015 to provide the scientific and industrial communities with a state-of-the-art reference facility is also discussed.

  14. Dark energy and modified gravity in the Effective Field Theory of Large-Scale Structure

    Science.gov (United States)

    Cusin, Giulia; Lewandowski, Matthew; Vernizzi, Filippo

    2018-04-01

    We develop an approach to compute observables beyond the linear regime of dark matter perturbations for general dark energy and modified gravity models. We do so by combining the Effective Field Theory of Dark Energy and Effective Field Theory of Large-Scale Structure approaches. In particular, we parametrize the linear and nonlinear effects of dark energy on dark matter clustering in terms of the Lagrangian terms introduced in a companion paper [1], focusing on Horndeski theories and assuming the quasi-static approximation. The Euler equation for dark matter is sourced, via the Newtonian potential, by new nonlinear vertices due to modified gravity and, as in the pure dark matter case, by the effects of short-scale physics in the form of the divergence of an effective stress tensor. The effective fluid introduces a counterterm in the solution to the matter continuity and Euler equations, which allows a controlled expansion of clustering statistics on mildly nonlinear scales. We use this setup to compute the one-loop dark-matter power spectrum.

  15. Graphene-based photovoltaic cells for near-field thermal energy conversion.

    Science.gov (United States)

    Messina, Riccardo; Ben-Abdallah, Philippe

    2013-01-01

    Thermophotovoltaic devices are energy-conversion systems generating an electric current from the thermal photons radiated by a hot body. While their efficiency is limited in far field by the Schockley-Queisser limit, in near field the heat flux transferred to a photovoltaic cell can be largely enhanced because of the contribution of evanescent photons, in particular for a source supporting a surface mode. Unfortunately, in the infrared where these systems operate, the mismatch between the surface-mode frequency and the semiconductor gap reduces drastically the potential of this technology. In this paper we propose a modified thermophotovoltaic device in which the cell is covered by a graphene sheet. By discussing the transmission coefficient and the spectral properties of the flux, we show that both the cell efficiency and the produced current can be enhanced, paving the way to promising developments for the production of electricity from waste heat.

  16. Cauchy horizon stability in a collapsing spherical dust cloud: II. Energy bounds for test fields and odd-parity gravitational perturbations

    Science.gov (United States)

    Ortiz, Néstor; Sarbach, Olivier

    2018-01-01

    We analyze the stability of the Cauchy horizon associated with a globally naked, shell-focussing singularity arising from the complete gravitational collapse of a spherical dust cloud. In a previous work, we have studied the dynamics of spherical test scalar fields on such a background. In particular, we proved that such fields cannot develop any divergences which propagate along the Cauchy horizon. In the present work, we extend our analysis to the more general case of test fields without symmetries and to linearized gravitational perturbations with odd parity. To this purpose, we first consider test fields possessing a divergence-free stress-energy tensor satisfying the dominant energy condition, and we prove that a suitable energy norm is uniformly bounded in the domain of dependence of the initial slice. In particular, this result implies that free-falling observers co-moving with the dust particles measure a finite energy of the field, even as they cross the Cauchy horizon at points lying arbitrarily close to the central singularity. Next, for the case of Klein–Gordon fields, we derive point-wise bounds from our energy estimates which imply that the scalar field cannot diverge at the Cauchy horizon, except possibly at the central singular point. Finally, we analyze the behaviour of odd-parity, linear gravitational and dust perturbations of the collapsing spacetime. Similarly to the scalar field case, we prove that the relevant gauge-invariant combinations of the metric perturbations stay bounded away from the central singularity, implying that no divergences can propagate in the vacuum region. Our results are in accordance with previous numerical studies and analytic work in the self-similar case.

  17. Biomass - Energy - Climate - From photosynthesis to bio-economy. V. 1: 'the energy from the fields'; V. 2: 'the energy from the woods'

    International Nuclear Information System (INIS)

    Brulhet, Jacques; Figuet, Raymond; Bardon, Eric; Bour-Poitrinal, Emmanuelle; Dereix, Charles; Leblanc-Cuvillier, Anick

    2011-10-01

    A fist volume presents, outlines and comments the possibilities of energy generation from the biomass produced in fields, the development potential of biomass production and of food industry, the challenge of bio-wastes and soil structure, the relationship between renewable energies and new crops, the development of agriculture to supply bio-refineries, produce biofuels and develop vegetal chemistry. Examples of biomass valorisation in la Reunion are presented. The second volume addresses the possibilities related to wood exploitation. It outlines ways to mobilise this resource, discusses the issue of forest exploitation in Guyana, gives an overview of wood applications, describes how to valorise forest carbon storage, gives an overview of innovation, governance and information for this specific sector, and evokes the place of bio-economy on markets

  18. Contribution and influence of proceedings papers to citation impact in seven conference and journal-driven sub-fields of energy research 2005-11

    DEFF Research Database (Denmark)

    Ingwersen, Peter; Larsen, Birger; Garcia-Zorita, J. Carlos

    2013-01-01

    and Wave Energy, Geo-thermal, Bio-fuel and Bio-mass energy sub-fields. The analyses cover research and review articles as well as conference proceeding papers excluding meeting abstracts published 2005-09 and cited 2005-11 through Web of Science. Central findings are: The distribution across document types......This paper analyses the following seven sub-fields of Sustainable Energy Research with respect to the influence of conference paper dominance on citation patterns across citing and cited document types, overall sub-field and document type impacts and citedness: Wind Power, Renewable Energy, Solar...

  19. Approximate energies and thermal properties of a position-dependent mass charged particle under external magnetic fields

    Institute of Scientific and Technical Information of China (English)

    M Eshghi; H Mehraban; S M Ikhdair

    2017-01-01

    We solve the Schr(o)dinger equation with a position-dependent mass (PDM) charged particle interacted via the superposition of the Morse-plus-Coulomb potentials and is under the influence of external magnetic and Aharonov-Bohm (AB) flux fields.The nonrelativistic bound state energies together with their wave functions are calculated for two spatially-dependent mass distribution functions.We also study the thermal quantifies of such a system.Further,the canonical formalism is used to compute various thermodynamic variables for second choosing mass by using the Gibbs formalism.We give plots for energy states as a function of various physical parameters.The behavior of the internal energy,specific heat,and entropy as functions of temperature and mass density parameter in the inverse-square mass case for different values of magnetic field are shown.

  20. Approximate energies and thermal properties of a position-dependent mass charged particle under external magnetic fields

    International Nuclear Information System (INIS)

    Eshghi, M; Mehraban, H; Ikhdair, S M

    2017-01-01

    We solve the Schrödinger equation with a position-dependent mass (PDM) charged particle interacted via the superposition of the Morse-plus-Coulomb potentials and is under the influence of external magnetic and Aharonov–Bohm (AB) flux fields. The nonrelativistic bound state energies together with their wave functions are calculated for two spatially-dependent mass distribution functions. We also study the thermal quantities of such a system. Further, the canonical formalism is used to compute various thermodynamic variables for second choosing mass by using the Gibbs formalism. We give plots for energy states as a function of various physical parameters. The behavior of the internal energy, specific heat, and entropy as functions of temperature and mass density parameter in the inverse-square mass case for different values of magnetic field are shown. (paper)

  1. Consumer behavior and energy conservation. A policy-oriented field experimental study on the effectiveness of behavioral interventions promoting residential energy conservation

    Energy Technology Data Exchange (ETDEWEB)

    Ester, P

    1984-01-01

    The primary goal of this study is to investigate the effectiveness of behavioral interventions aimed at promoting energy conservation by consumers. It is argued that energy conservation has many advantages over other energy policy options, especially with respect to sociopolitical, economic, technical, safety and environmental considerations. Theories are discussed which deal with micromotives behind individual energy consumption and their macroconsequences. Antecedent and consequence behavioral interventions (information/education, prompting, modeling, feedback, self-monitoring, reinforcement/punishment) for promoting energy conservation by consumers are analyzed, and an extensive review is presented of behavioral experiments conducted in this area. Discussed is how the field experiment, which was conducted in five cities in the Netherlands with appr. 400 subjects, has been implemented. Hypotheses are tested regarding belief structures with respect to energy conservation. Provided are data about the absolute and relative effectiveness of energy conservation information, biweekly and monthly feedback, and self-monitoring in encouraging consumers to conserve energy. Hypotheses are tested about cognitive aspects related to responsiveness to behavioral interventions and attitude change toward energy conservation. Conclusions are presented and some energy policy recommendations and directions for future research are formulated. (J.C.R.)

  2. Hydrogenic-Donor Impurity Binding Energy Dependence of the Electric Field in GaAs/AlxGa1−xAs Quantum Rings

    Directory of Open Access Journals (Sweden)

    Guangxin Wang

    2013-01-01

    Full Text Available Using a variational method with two-parameter trial wave function and the effective mass approximation, the binding energy of a donor impurity in GaAs/AlxGa1−xAs cylindrical quantum ring (QR subjected to an external field is calculated. It is shown that the donor impurity binding energy is highly dependent on the QR structure parameters (radial thickness and height, impurity position, and external electric field. The binding energy increases inchmeal as the QR parameters (radial thickness and height decrease until a maximum value for a central impurity and then begins to drop quickly. The applied electric field can significantly modify the spread of electronic wave function in the QR and shift electronic wave function from the donor position and then leads to binding energy changes. In addition, results for the binding energies of a hydrogenic donor impurity as functions of the impurity position and applied electric field are also presented.

  3. Free-Free Transitions in the Presence of Laser Fields at Very Low Incident Electron Energy

    Science.gov (United States)

    Bhatia, A. K.; Sinha, Chandana

    2010-01-01

    We study the free-free transition in electron-hydrogenic systems in ground state in presence of an external laser field at very loud incident energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen to be monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser in a nonperturbative manner by choosing a Volkov wave function for it. The scattering weave function for the electron is solved numerically by taking into account the effect of the electron exchange, short-range as well as of the long-range interactions to get the S and P wave phase shifts while for the higher angular momentum phase shifts the exchange approximation has only been considered. We calculate the laser assisted differential cross sections (LADCS) for the aforesaid free-free transition process for single photon absorption/emission. The laser intensity is chosen to be much less than the atomic field intensity. A strong suppression is noted in the LADCS as compared to the field free (FF) cross sections. Unlike the FF ones, the LADCS exhibit some oscillations having a distinct maximum at a low value of the scattering angle depending on the laser parameters as well as on the incident energies.

  4. Fokusområde: Faglig udvikling og fagligt samspil

    DEFF Research Database (Denmark)

    Hobel, Peter

    2017-01-01

    Artiklen er trykt i et særnummer af tidsskriftet GymPæd2.0, der præsenterer SDU/IKVs følgeforskningsprogram "Reform 2017"......Artiklen er trykt i et særnummer af tidsskriftet GymPæd2.0, der præsenterer SDU/IKVs følgeforskningsprogram "Reform 2017"...

  5. Measurements and Monte Carlo calculations with the extended-range Bonner sphere spectrometer at high-energy mixed fields

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00406842; Bay, Aurelio; Silari, Marco; Aroua, Abbas

    The use of spectrometry to provide information for neutron radiation protection has become an increasingly important activity over recent years. The need for spectral data arises because neither area survey instruments nor personal dosimeters give the correct dose equivalent results at all neutron energies. It is important therefore to know the spectra of the fields in which these devices are used. One of the systems most commonly employed in neutron spectrometry and dosimetry is the Bonner Sphere Spectrometers (BSS). The extended- range BSS that was used for this work, consists of 7 spheres with an overall response to neutrons up to 2 GeV. A 3He detector is used as a thermal counter in the centre of each sphere. In the context of this thesis the BSS was calibrated in monoenergetic neutron fields at low and intermediate energies. It was also used for measurements in several high energy mixed fields. These measurements have led to the calculation of neutron yields and spectral fluences from unshielded targets....

  6. Enhanced energy transfer by near-field coupling of a nanostructured metamaterial with a graphene-covered plate

    International Nuclear Information System (INIS)

    Chang, Jui-Yung; Yang, Yue; Wang, Liping

    2016-01-01

    Coupled surface plasmon/phonon polaritons and hyperbolic modes are known to enhance radiative transfer across nanometer vacuum gaps but usually require identical materials. It becomes crucial to achieve strong near-field energy transfer between dissimilar materials for applications like near-field thermophotovoltaic and thermal rectification. In this work, we theoretically demonstrate enhanced near-field radiative transfer between a nanostructured metamaterial emitter and a graphene-covered planar receiver. Strong near-field coupling with two orders of magnitude enhancement in the spectral heat flux is achieved at the gap distance of 20 nm. By carefully selecting the graphene chemical potential and doping levels of silicon nanohole emitter and silicon plate receiver, the total near-field radiative heat flux can reach about 500 times higher than the far-field blackbody limit between 400 K and 300 K. The physical mechanism is elucidated by the near-field surface plasmon coupling with fluctuational electrodynamics and dispersion relations. The effects of graphene chemical potential, emitter and receiver doping levels, and vacuum gap distance on the near-field coupling and radiative energy transfer are analyzed in detail. - Highlights: • Near-field radiative transfer between a metamaterial and a graphene-covered plate is studied. • Effective medium theory with uniaxial optics is employed to model nanohole metamaterials. • Enhancement by 2 orders is found between dissimilar materials with graphene coating. • Extraordinary coupling of the nanostructured emitter with graphene is elucidated. • Effects of doping level of silicon and graphene chemical potential are investigated.

  7. New holographic scalar field models of dark energy in non-flat universe

    Energy Technology Data Exchange (ETDEWEB)

    Karami, K., E-mail: KKarami@uok.ac.i [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Fehri, J. [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of)

    2010-02-08

    Motivated by the work of Granda and Oliveros [L.N. Granda, A. Oliveros, Phys. Lett. B 671 (2009) 199], we generalize their work to the non-flat case. We study the correspondence between the quintessence, tachyon, K-essence and dilaton scalar field models with the new holographic dark energy model in the non-flat FRW universe. We reconstruct the potentials and the dynamics for these scalar field models, which describe accelerated expansion of the universe. In the limiting case of a flat universe, i.e. k=0, all results given in [L.N. Granda, A. Oliveros, Phys. Lett. B 671 (2009) 199] are obtained.

  8. New holographic scalar field models of dark energy in non-flat universe

    International Nuclear Information System (INIS)

    Karami, K.; Fehri, J.

    2010-01-01

    Motivated by the work of Granda and Oliveros [L.N. Granda, A. Oliveros, Phys. Lett. B 671 (2009) 199], we generalize their work to the non-flat case. We study the correspondence between the quintessence, tachyon, K-essence and dilaton scalar field models with the new holographic dark energy model in the non-flat FRW universe. We reconstruct the potentials and the dynamics for these scalar field models, which describe accelerated expansion of the universe. In the limiting case of a flat universe, i.e. k=0, all results given in [L.N. Granda, A. Oliveros, Phys. Lett. B 671 (2009) 199] are obtained.

  9. EU-China Cooperation In the Field of Energy, Environment and Climate Change

    Directory of Open Access Journals (Sweden)

    Pietro De Matteis

    2010-11-01

    Full Text Available The evolution of the energy market and the intrinsic worldwide scope of environmental threats, such as climate change, are two elements that have pushed the world towards shared approaches to global governance via bilateral institutions and international regimes. This article, with the aid of an institutionalist approach, presents the current status of the EU-China relationship, which is characterised by high institutionalisation, and it underlines how their bilateral cooperation has progressively focused on energy and climate change-related issues. In particular, the article sheds some light on the linkages between energy, environment and climate change and how these have created the basis for the upgrade of the EU-China bilateral relationship to its current level. To do so, it underlines some of the tools, the main frameworks and some of the key outcomes of their bilateral cooperation in these fields.

  10. Laboratory constraints on chameleon dark energy and power-law fields

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Upadhye, Amol; Baumbaugh, Al; Chou, Aaron S.; Mazur, Peter O.; Tomlin, Ray; Weltman, Amanda; Wester, William

    2010-01-01

    We report results from the GammeV Chameleon Afterglow Search - a search for chameleon particles created via photon/chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of chameleon power-law models and dark energy models not previously explored. These results exclude five orders of magnitude in the coupling of chameleons to photons covering a range of four orders of magnitude in chameleon effective mass and, for individual chameleon models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter.

  11. Solar Wind Energy Input during Prolonged, Intense Northward Interplanetary Magnetic Fields: A New Coupling Function

    Science.gov (United States)

    Du, A. M.; Tsurutani, B. T.; Sun, W.

    2012-04-01

    Sudden energy release (ER) events in the midnight sector at auroral zone latitudes during intense (B > 10 nT), long-duration (T > 3 hr), northward (Bz > 0 nT = N) IMF magnetic clouds (MCs) during solar cycle 23 (SC23) have been examined in detail. The MCs with northward-then-southward (NS) IMFs were analyzed separately from MCs with southward-then-northward (SN) configurations. It is found that there is a lack of substorms during the N field intervals of NS clouds. In sharp contrast, ER events do occur during the N field portions of SN MCs. From the above two results it is reasonable to conclude that the latter ER events represent residual energy remaining from the preceding S portions of the SN MCs. We derive a new solar wind-magnetosphere coupling function during northward IMFs: ENIMF = α N-1/12V 7/3B1/2 + β V |Dstmin|. The first term on the right-hand side of the equation represents the energy input via "viscous interaction", and the second term indicates the residual energy stored in the magnetotail. It is empirically found that the magnetosphere/magnetotail can store energy for a maximum of ~ 4 hrs before it has dissipated away. This concept is defining one for ER/substorm energy storage. Our scenario indicates that the rate of solar wind energy injection into the magnetosphere/magnetotail determines the form of energy release into the magnetosphere/ionosphere. This may be more important than the dissipation mechanism itself (in understanding the form of the release). The concept of short-term energy storage is applied for the solar case. It is argued that it may be necessary to identify the rate of energy input into solar magnetic loop systems to be able to predict the occurrence of solar flares.

  12. Analytical free energy gradient for the molecular Ornstein-Zernike self-consistent-field method

    Directory of Open Access Journals (Sweden)

    N.Yoshida

    2007-09-01

    Full Text Available An analytical free energy gradient for the molecular Ornstein-Zernike self-consistent-field (MOZ-SCF method is presented. MOZ-SCF theory is one of the theories to considering the solvent effects on the solute electronic structure in solution. [Yoshida N. et al., J. Chem. Phys., 2000, 113, 4974] Molecular geometries of water, formaldehyde, acetonitrile and acetone in water are optimized by analytical energy gradient formula. The results are compared with those from the polarizable continuum model (PCM, the reference interaction site model (RISM-SCF and the three dimensional (3D RISM-SCF.

  13. Method for fitting crystal field parameters and the energy level fitting for Yb3+ in crystal SC2O3

    International Nuclear Information System (INIS)

    Qing-Li, Zhang; Kai-Jie, Ning; Jin, Xiao; Li-Hua, Ding; Wen-Long, Zhou; Wen-Peng, Liu; Shao-Tang, Yin; Hai-He, Jiang

    2010-01-01

    A method to compute the numerical derivative of eigenvalues of parameterized crystal field Hamiltonian matrix is given, based on the numerical derivatives the general iteration methods such as Levenberg–Marquardt, Newton method, and so on, can be used to solve crystal field parameters by fitting to experimental energy levels. With the numerical eigenvalue derivative, a detailed iteration algorithm to compute crystal field parameters by fitting experimental energy levels has also been described. This method is used to compute the crystal parameters of Yb 3+ in Sc 2 O 3 crystal, which is prepared by a co-precipitation method and whose structure was refined by Rietveld method. By fitting on the parameters of a simple overlap model of crystal field, the results show that the new method can fit the crystal field energy splitting with fast convergence and good stability. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  14. The impact of ICRP 60 recommendations on the dose equivalent in low- and high energy neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Jakes, J; Schraube, H [GSF-Forschungszentrum Neuberg, D-85758 Oberschleissheim (Germany). Inst. fuer Strahlenschutz

    1996-12-31

    The objectives of this study was to determine the impact of the increased risk factors for neutrons after ICRP 60 on the operational dose equivalent quantities at a few neutron fields selected with the respect to cover the broad variety of neutron spectra: (1) Cadarache calibration assembly, with average neutron energy around 0.6 MeV, designed to simulate realistic neutron spectra at workplaces. This assembly is basically composed of an almost spherical {sup 238}U converter irradiated by 14.6 MeV neutrons from an accelerator target, placed at its center, and a scattering chamber consisting of a cylindrical polyethylene duct and a series of additional shieldings; (2) Neutron spectra at exposed workplaces in nuclear power plants; (3) Moderated spectra of {sup 252}Cf fission source; (4) Neutron spectra behind a shielding made of the iron (the average energy 5.,89 MeV) and concrete (the average energy 46.51 MeV), respectively; (5) Cosmic rays induced neutron spectra measured on the top of the Zugspitze (2968 m) where there is the average neutron energy around 40 MeV. From the derived neutron spectra, the mean quality factors and conversion factors h after ICRP 21 and ICRP 60, respectively, were calculated. The dose equivalent conversion factors were taken for the region below 20 MeV, and the energy region above 20 MeV. The results show that the operational quantities were affected predominately in the low energy fields, where the changes are given by a factor of 1,3 for the neutron fields given above. As has been expected, the impact of the new recommendations depends on the shape of the neutron spectra. Therefore, this factor can be much higher in the fields where the intermediate energy region is dominant, which is the case of moderated and scattered spectra at some places in the nuclear power plant and around containers with the spent fuel elements. (J.K.) 9 refs.

  15. PUBLIC POLITICS IN THE ENERGY FIELD

    Directory of Open Access Journals (Sweden)

    Carmen RADU

    2015-07-01

    Full Text Available The present endeavor proposes the analysis of public politics which regard the energy sector. The energy sector represents a fundamental and determining component in the states’ social-economic development, a sector which is related even to national security. The European Union is the largest energy importer on a global scale, importing approximately half of the energy demand and the pessimistic projection is placed at approximately 70% in the perspective of the following two decades. Accomplishing energy security on the European Union’s level implies a number of directions for action: diversifying the sources and routes of transport in regard to natural gases; intertwining member countries so that no E.U. state is left isolated in crisis situations; decreasing dependency of conventional sources and increasing energy efficiency; reinforced dialogue with energy suppliers.

  16. Vacuum energy induced by an external magnetic field in a curved space

    International Nuclear Information System (INIS)

    Sitenko, Yu.A.; Rakityansky, D.G.

    1998-01-01

    The asymptotic expansion of the product of an operator raised to an arbitrary power and an exponential function of this operator is obtained. With the aid of this expansion, the density of vacuum energy induced by a static external magnetic field of an Abelian or a non-Abelian nature is expressed in terms of the DeWitt-Seeley-Gilkey coefficients

  17. DOSIMETRIC response of a REM-500 in low energy neutron fields typical of nuclear power plants.

    Science.gov (United States)

    Aslam; Matysiak, W; Atanackovic, J; Waker, A J

    2012-06-01

    This study investigates the response of a REM-500 to assess neutron quality factor and dose equivalent in low energy neutron fields, which are commonly encountered in the workplace environment of nuclear power stations. The McMaster University 3 MV Van de Graaff accelerator facility was used to measure the response of the instrument in monoenergetic neutron fields in the energy range 51 to 727 keV by bombarding a thin LiF target with 1.93-2.50 MeV protons. The energy distribution of the neutron fields produced in the facility was measured by a (3)He filled gas ionization chamber. The MCA mode of the REM-500 instrument was used to collect lineal energy distributions at varying neutron energies and to calculate the frequency and dose-mean lineal energies. The effective quality factor, Q-, was also calculated using the values of Q(y)listed in the REM-500 operation manual and compared with those of ICRP 60. The authors observed a continuously increasing trend in y - F, y-D, and Q-with an increase in neutron energy. It is interesting to note that standard tissue equivalent proportional counters (TEPCs) filled with tissue equivalent(TE) gas give rise to a similar trend for these microdosimetric quantities of interest in the same energy range; however, the averages calculated in this study are larger by about 15%compared to a TEPC filled with propane-based TE gas probably because of the larger stopping power of protons in propane compared to TE gas. These somewhat larger event sizes did not result in any significant increase in the Q-compared to those obtained from a TEPC filled with TE gas and were found to be in good agreement with other measurements reported earlier at corresponding neutron energies. The instrument quality factor response, R(Q), defined as the ratio of measured quality factor to the calculated quality factor in an ICRU tissue sphere,was found to vary with neutron energy. The instrument response,R(Q), was ~0.6 at 727 keV, which deteriorates further to

  18. Effects of Energy Relaxation via Quantum Coupling Among Three-Dimensional Motion on the Tunneling Current of Graphene Field-Effect Transistors.

    Science.gov (United States)

    Mao, Ling-Feng; Ning, Huansheng; Li, Xijun

    2015-12-01

    We report theoretical study of the effects of energy relaxation on the tunneling current through the oxide layer of a two-dimensional graphene field-effect transistor. In the channel, when three-dimensional electron thermal motion is considered in the Schrödinger equation, the gate leakage current at a given oxide field largely increases with the channel electric field, electron mobility, and energy relaxation time of electrons. Such an increase can be especially significant when the channel electric field is larger than 1 kV/cm. Numerical calculations show that the relative increment of the tunneling current through the gate oxide will decrease with increasing the thickness of oxide layer when the oxide is a few nanometers thick. This highlights that energy relaxation effect needs to be considered in modeling graphene transistors.

  19. N2O Emission from energy crop fields

    International Nuclear Information System (INIS)

    Joergensen, B.J.; Nyholm Joergensen, R.

    1996-03-01

    The interest in N 2 O emissions from soils with energy crops is a results of its properties as a greenhouse gas, since the global warming potential of N 2 O per unit mass is about 320 times greater than CO 2 . The contribution of N 2 O from the soil to the atmosphere may increase due to agricultural management. Consequently, large N 2 O emissions can lower the reduction of the greenhouse effect achieved by the substitution of fossil fuels by energy crops. For this reason it is crucial to find the crops for combustion with the lowest potential for emission of N 2 O from the soil per produced energy unit. The aims of this study were to assess the annual N 2 O flux from a Miscanthus 'Giganteus' (M. 'Giganteus') and winter rye (Secale cereale) field, and to investigate the factors affecting the N 2 O emission. To obtain these aims a method was developed for measurements in tall crops. The thesis contains a literature review on the N 2 O emission from the soils, a section with development of the technique for N 2 O flux measurements, and an experimental section. Finally, the thesis contains a section where the results are discussed in relation to the use of energy crops. In all the filed studies, the N 2 O emission was measured by using a new developed closed-chamber technique. The main advantages of the chamber method were the ability to contain growing plants up to a height of 3 m, and the relatively large area (2X2m) covered by each other. Soils with annual and perennial crops can be expected to emit less then 3 kg N 2 O ha -1 yr -1 . This amount corresponds to 960 kg CO 2 ha -1 yr -1 compared to a total CO 2 reduction of 10 to 19 tons CO 2 ha -1 yr -1 using the energy crops as substitution for fossil fuels. An efficient way to reduce the N 2 O emission is to exclude use of fertiliser but this also reduces the dry matter yield and consequently also the CO 2 reduction per unit dry matter. Following the guidelines for good agricultural practice concerning the

  20. Integrable covariant law of energy-momentum conservation for a gravitational field with the absolute parallelism structure

    International Nuclear Information System (INIS)

    Asanov, G.S.

    1979-01-01

    It is shown the description of gravitational field in the riemannian space-time by means of the absolute parallelism structure makes it possible to formulate an integrable covariant law of energy-momentum conservation for gravitational field, by imposing on the energy-momentum tensor the condition of vanishing of the covariant divergence (in the sense of the absolute parallelism). As a result of taking into account covariant constraints for the tetrads of the absolute parallelism, the Lagrangian density turns out to be not geometrised anymore and leads to the unambiguous conservation law of the type mentioned in the N-body problem. Covariant field equations imply the existence of the special euclidean coordinates outside of static neighbourhoods of gravitationing bodies. In these coordinates determined by the tetrads of the absolute parallelism, the linear approximation is not connected with any noncovariant assumptions

  1. Strain fields and line energies of dislocations in uranium dioxide

    International Nuclear Information System (INIS)

    Parfitt, David C; Bishop, Clare L; Wenman, Mark R; Grimes, Robin W

    2010-01-01

    Computer simulations are used to investigate the stability of typical dislocations in uranium dioxide. We explain in detail the methods used to produce the dislocation configurations and calculate the line energy and Peierls barrier for pure edge and screw dislocations with the shortest Burgers vector 1/2 . The easiest slip system is found to be the {100}(110) system for stoichiometric UO 2 , in agreement with experimental observations. We also examine the different strain fields associated with these line defects and the close agreement between the strain field predicted by atomic scale models and the application of elastic theory. Molecular dynamics simulations are used to investigate the processes of slip that may occur for the three different edge dislocation geometries and nudged elastic band calculations are used to establish a value for the Peierls barrier, showing the possible utility of the method in investigating both thermodynamic average behaviour and dynamic processes such as creep and plastic deformation.

  2. Field tests applying multi-agent technology for distributed control. Virtual power plants and wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Schaeffer, G.J.; Warmer, C.J.; Hommelberg, M.P.F.; Kamphuis, I.G.; Kok, J.K. [Energy in the Built Environment and Networks, Petten (Netherlands)

    2007-01-15

    Multi-agent technology is state of the art ICT. It is not yet widely applied in power control systems. However, it has a large potential for bottom-up, distributed control of a network with large-scale renewable energy sources (RES) and distributed energy resources (DER) in future power systems. At least two major European R and D projects (MicroGrids and CRISP) have investigated its potential. Both grid-related as well as market-related applications have been studied. This paper will focus on two field tests, performed in the Netherlands, applying multi-agent control by means of the PowerMatcher concept. The first field test focuses on the application of multi-agent technology in a commercial setting, i.e. by reducing the need for balancing power in the case of intermittent energy sources, such as wind energy. In this case the flexibility is used of demand and supply of industrial and residential consumers and producers. Imbalance reduction rates of over 40% have been achieved applying the PowerMatcher, and with a proper portfolio even larger rates are expected. In the second field test the multi-agent technology is used in the design and implementation of a virtual power plant (VPP). This VPP digitally connects a number of micro-CHP units, installed in residential dwellings, into a cluster that is controlled to reduce the local peak demand of the common low-voltage grid segment the micro-CHP units are connected to. In this way the VPP supports the local distribution system operator (DSO) to defer reinforcements in the grid infrastructure (substations and cables)

  3. Field tests applying multi-agent technology for distributed control. Virtual power plants and wind energy

    International Nuclear Information System (INIS)

    Schaeffer, G.J.; Warmer, C.J.; Hommelberg, M.P.F.; Kamphuis, I.G.; Kok, J.K.

    2007-01-01

    Multi-agent technology is state of the art ICT. It is not yet widely applied in power control systems. However, it has a large potential for bottom-up, distributed control of a network with large-scale renewable energy sources (RES) and distributed energy resources (DER) in future power systems. At least two major European R and D projects (MicroGrids and CRISP) have investigated its potential. Both grid-related as well as market-related applications have been studied. This paper will focus on two field tests, performed in the Netherlands, applying multi-agent control by means of the PowerMatcher concept. The first field test focuses on the application of multi-agent technology in a commercial setting, i.e. by reducing the need for balancing power in the case of intermittent energy sources, such as wind energy. In this case the flexibility is used of demand and supply of industrial and residential consumers and producers. Imbalance reduction rates of over 40% have been achieved applying the PowerMatcher, and with a proper portfolio even larger rates are expected. In the second field test the multi-agent technology is used in the design and implementation of a virtual power plant (VPP). This VPP digitally connects a number of micro-CHP units, installed in residential dwellings, into a cluster that is controlled to reduce the local peak demand of the common low-voltage grid segment the micro-CHP units are connected to. In this way the VPP supports the local distribution system operator (DSO) to defer reinforcements in the grid infrastructure (substations and cables)

  4. High-energy hadron dynamics based on a stochastic-field multieikonal theory

    International Nuclear Information System (INIS)

    Arnold, R.C.

    1977-01-01

    Multieikonal theory, using a stochastic-field representation for collective long-range rapidity correlations, is developed and applied to the calculation of Regge-pole parameters, high-transverse-momentum enhancements, and fluctuation patterns in rapidity densities. If a short-range-order model, such as the one-dimensional planar bootstrap, with only leading t-channel meson poles, is utilized as input to the multieikonal method, the pole spectrum is modified in three ways: promotion and renormalization of leading trajectories (suggesting an effective Pomeron above unity at intermediate energies), and a proliferation of dynamical secondary trajectories, reminiscent of dual models. When transverse dimensions are included, the collective effects produce a growth with energy of large-P/sub T/ inclusive cross sections. Typical-event rapidity distributions, at energies of a few TeV, can be estimated by suitable approximations; the fluctuations give rise to ''domain'' patterns, which have the appearance of clusters separated by rapidity gaps. The relations between this approach to strong-interaction dynamics and a possible unification of weak, electromagnetic, and strong interactions are outlined

  5. Magnetic field-dependent of binding energy in GaN/InGaN/GaN spherical QDQW nanoparticles

    International Nuclear Information System (INIS)

    El Ghazi, Haddou; Jorio, Anouar; Zorkani, Izeddine

    2013-01-01

    Simultaneous study of magnetic field and impurity's position effects on the ground-state shallow-donor binding energy in GaN|InGaN|GaN (core|well|shell) spherical quantum dot–quantum well (SQDQW) as a function of the ratio of the inner and the outer radius is reported. The calculations are investigated within the framework of the effective-mass approximation and an infinite deep potential describing the quantum confinement effect. A Ritz variational approach is used taking into account of the electron-impurity correlation and the magnetic field effect in the trial wave-function. It appears that the binding energy depends strongly on the external magnetic field, the impurity's position and the structure radius. It has been found that: (i) the magnetic field effect is more marked in large layer than in thin layer and (ii) it is more pronounced in the spherical layer center than in its extremities

  6. Development, Demonstration, and Field Testing of Enterprise-Wide Distributed Generation Energy Management System: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, S.; Cooley, C.

    2005-01-01

    This report details progress on subcontract NAD-1-30605-1 between the National Renewable Energy Laboratory and RealEnergy (RE), the purpose of which is to describe RE's approach to the challenges it faces in the implementation of a nationwide fleet of clean cogeneration systems to serve contemporary energy markets. The Phase 2 report covers: utility tariff risk and its impact on market development; the effect on incentives on distributed energy markets; the regulatory effectiveness of interconnection in California; a survey of practical field interconnection issues; trend analysis for on-site generation; performance of dispatch systems; and information design hierarchy for combined heat and power.

  7. On the binding energy of double Λ hypernuclei in the relativistic mean field theory

    International Nuclear Information System (INIS)

    Marcos, S.; Lombard, R.J.

    1997-01-01

    The binding energy of two Λ hyperons bound to a nuclear core is calculated within the relativistic mean field theory. The starting point is a two body relativistic equation of the Breit type suggested by the RMFT, and corrected for the two-particle interaction. The 2 Λ correlation energy is evaluated and the contribution of the δ and φ mesons, acting solely between hyperons, to the bond energy σB ΛΛ of ( ΛΛ ) 6 He, ( ΛΛ ) 10 Be and ( ΛΛ ) 13 B is calculated. Predictions of the ΔB ΛΛ A dependence are made for heavier Λ-hypernuclei. (K.A.)

  8. Energy system for the generation of divertor magnetic fields in the PDX fusion research device

    International Nuclear Information System (INIS)

    Turitzin, N.M.

    1975-01-01

    One of the major problems encountered in the development of Tokamak type fusion reactors is the presence of impurities in the plasma. The PDX device is designed to study the operation of poloidal magnetic field divertors and consequent magnetic limiters for controlling and reducing the amount of impurities. A system of coils placed at specific locations produces a required field configuration for the poloidal divertor. This paper describes the system of energy supplies required and the interrelations of field coil currents during plasma current initiation, growth and steady state

  9. Energy system for the generation of divertor magnetic fields in the PDX fusion research device

    International Nuclear Information System (INIS)

    Turitzin, N.M.

    1976-05-01

    One of the major problems encountered in the development of Tokamak type fusion reactors is the presence of impurities in the plasma. The PDX device is designed to study the operation of poloidal magnetic field divertors and consequent magnetic limiters for controlling and reducing the amount of impurities. A system of coils placed at specific locations produces a required field configuration for the poloidal divertor. This paper describes the system of energy supplies required and the interrelations of field coil currents during plasma current initiation, growth and steady state

  10. Energy dissipation of Alfven wave packets deformed by irregular magnetic fields in solar-coronal arches

    Science.gov (United States)

    Similon, Philippe L.; Sudan, R. N.

    1989-01-01

    The importance of field line geometry for shear Alfven wave dissipation in coronal arches is demonstrated. An eikonal formulation makes it possible to account for the complicated magnetic geometry typical in coronal loops. An interpretation of Alfven wave resonance is given in terms of gradient steepening, and dissipation efficiencies are studied for two configurations: the well-known slab model with a straight magnetic field, and a new model with stochastic field lines. It is shown that a large fraction of the Alfven wave energy flux can be effectively dissipated in the corona.

  11. French know-how in the field of geothermal energy. District heating and electricity generation systems

    International Nuclear Information System (INIS)

    2012-08-01

    This brochure is aimed at presenting the French expertise, public and private, at international level in the field of geothermal energy (district heating and electricity generation systems). It presents a summary of the French public policy framework, measures to support Research and Development, innovation and training and offers from private companies. It has been designed by the ADEME in cooperation with the French ministry for Ecology and Sustainable Development, the French association of geothermal energy professionals, Ubifrance (the French Agency for international business development) and the French renewable energies union

  12. Low energy atomic field bremsstrahlung from thin rare gas targets

    International Nuclear Information System (INIS)

    Semaan, M.E.

    1982-01-01

    A relative measurement of the doubly-differential cross-section for electron atomic field bremsstrahling, differential in photon energy and angle is reported. Data for (d 2 sigma)/(dk dO/sub k/) have been taken for incident electron energies T ranging from 4 to 10 keV on target atoms of helium, neon, argon, krypton and xenon at a photon emission angle of 90 0 . The X-rays, produced at 90 0 to the intersection of the crossed electron and gas beams, are detected by a Si(Li) detector, having a resolution of about 200 eV at 6 keV and 0.3 mil Be window. The theoretical angular distribution (d 2 sigma)/(dk dO/sub k/) has been deduced from the photon energy spectrum by the use of the shape function S(Z,T,k,T) defined by Tseng and Pratt as S(Z,T,k,T) = [(d 2 sigma)/(dk dO/sub k/)] / [(dsigma)/(dk)]. The values of S used were obtained by an interpolation of the benchmark data provided by Pratt et al. Agreement between our experiment and the theory is measured by how well the theoretical curve fits the data. The agreement appeared to be good

  13. Energy modulation of nonrelativistic electrons in an optical near field on a metal microslit

    OpenAIRE

    R., Ishikawa; Jongsuck, Bae; K., Mizuno

    2001-01-01

    Energy modulation of nonrelativistic electrons with a laser beam using a metal microslit as an interaction circuit has been investigated. An optical near field is induced in the proximity of the microslit by illumination of the laser beam. The electrons passing close to the slit are accelerated or decelerated by an evanescent wave contained in the near field whose phase velocity is equal to the velocity of the electrons. The electron-evanescent wave interaction in the microslit has been analy...

  14. Controlled soil warming powered by alternative energy for remote field sites.

    Science.gov (United States)

    Johnstone, Jill F; Henkelman, Jonathan; Allen, Kirsten; Helgason, Warren; Bedard-Haughn, Angela

    2013-01-01

    Experiments using controlled manipulation of climate variables in the field are critical for developing and testing mechanistic models of ecosystem responses to climate change. Despite rapid changes in climate observed in many high latitude and high altitude environments, controlled manipulations in these remote regions have largely been limited to passive experimental methods with variable effects on environmental factors. In this study, we tested a method of controlled soil warming suitable for remote field locations that can be powered using alternative energy sources. The design was tested in high latitude, alpine tundra of southern Yukon Territory, Canada, in 2010 and 2011. Electrical warming probes were inserted vertically in the near-surface soil and powered with photovoltaics attached to a monitoring and control system. The warming manipulation achieved a stable target warming of 1.3 to 2 °C in 1 m(2) plots while minimizing disturbance to soil and vegetation. Active control of power output in the warming plots allowed the treatment to closely match spatial and temporal variations in soil temperature while optimizing system performance during periods of low power supply. Active soil heating with vertical electric probes powered by alternative energy is a viable option for remote sites and presents a low-disturbance option for soil warming experiments. This active heating design provides a valuable tool for examining the impacts of soil warming on ecosystem processes.

  15. Controlled soil warming powered by alternative energy for remote field sites.

    Directory of Open Access Journals (Sweden)

    Jill F Johnstone

    Full Text Available Experiments using controlled manipulation of climate variables in the field are critical for developing and testing mechanistic models of ecosystem responses to climate change. Despite rapid changes in climate observed in many high latitude and high altitude environments, controlled manipulations in these remote regions have largely been limited to passive experimental methods with variable effects on environmental factors. In this study, we tested a method of controlled soil warming suitable for remote field locations that can be powered using alternative energy sources. The design was tested in high latitude, alpine tundra of southern Yukon Territory, Canada, in 2010 and 2011. Electrical warming probes were inserted vertically in the near-surface soil and powered with photovoltaics attached to a monitoring and control system. The warming manipulation achieved a stable target warming of 1.3 to 2 °C in 1 m(2 plots while minimizing disturbance to soil and vegetation. Active control of power output in the warming plots allowed the treatment to closely match spatial and temporal variations in soil temperature while optimizing system performance during periods of low power supply. Active soil heating with vertical electric probes powered by alternative energy is a viable option for remote sites and presents a low-disturbance option for soil warming experiments. This active heating design provides a valuable tool for examining the impacts of soil warming on ecosystem processes.

  16. Electric and magnetic field modulated energy dispersion, conductivity and optical response in double quantum wire with spin-orbit interactions

    Science.gov (United States)

    Karaaslan, Y.; Gisi, B.; Sakiroglu, S.; Kasapoglu, E.; Sari, H.; Sokmen, I.

    2018-02-01

    We study the influence of electric field on the electronic energy band structure, zero-temperature ballistic conductivity and optical properties of double quantum wire. System described by double-well anharmonic confinement potential is exposed to a perpendicular magnetic field and Rashba and Dresselhaus spin-orbit interactions. Numerical results show up that the combined effects of internal and external agents cause the formation of crossing, anticrossing, camel-back/anomaly structures and the lateral, downward/upward shifts in the energy dispersion. The anomalies in the energy subbands give rise to the oscillation patterns in the ballistic conductance, and the energy shifts bring about the shift in the peak positions of optical absorption coefficients and refractive index changes.

  17. Significance of Space Charge and the Earth Magnetic Field on the Dispersive Characteristics of a Low Energy Electron Beam

    CERN Document Server

    Kishek, Rami A; Bernal, Santiago; Godlove, Terry; Haber, Irving; Quinn, Bryan; Reiser, Martin; Tobin, C; Walter, Mark

    2005-01-01

    The combination of energy spread and space charge provides a rich domain for interesting beam dynamics that are currently not well understood. The University of Maryland Electron Ring (UMER) [1] is a small scaled ring designed to probe the little-known regions of higher beam intensities using low-energy electrons. As such, design, commissioning and operation of UMER present many challenges, some quite novel. For example the UMER beam energy of 10 keV makes the beam very sensitive to the Earth magnetic field, which we can fortunately use to assist in bending the beam. This paper presents a systematic simulation study of the interaction of space charge and energy spread, with and without the earth magnetic field.

  18. The relationships between the European Union and Russia in the field of energy

    International Nuclear Information System (INIS)

    2009-01-01

    This report which has been prepared by members of the French National Assembly, questions the reliability of the relationship between the European Union and Russia in the field of energy. It highlights the doubts and fears born by the recent context of tensions between Russia and Ukraine and the weakness of the agreement between these two countries, but also the resulting fears for energy security, the renewal of geopolitical tensions. It comments the apparent weakness of Europeans in front of the Russian 'giants', and regrets the absence of a European energy policy. Then, trying to adopt Moscow's point of view, the authors reviews the different tensions with the EU, discuss the will of Russia to reaffirm its power and how the existence of the EU is actually perceived, the strengths and weaknesses of an economy which is oriented toward raw materials. In the second part of this report, the authors are trying to define a multi-step solution of these tensions and problems, notably by building up a common European energy policy, developing new energies, and finding new suppliers

  19. Strain Energy Density in the Elastodynamics of the Spacetime Continuum and the Electromagnetic Field

    Directory of Open Access Journals (Sweden)

    Millette P. A.

    2013-04-01

    Full Text Available We investigate the strain energy density of the spacetime continuum in the Elasto- dynamics of the Spacetime Continuum by applying continuum m echanical results to strained spacetime. The strain energy density is a scalar. W e find that it is separated into two terms: the first one expresses the dilatation energy density (the “mass” longitu- dinal term while the second one expresses the distortion en ergy density (the “massless” transverse term. The quadratic structure of the energy rel ation of Special Relativity is found to be present in the theory. In addition, we find that the kinetic energy pc is car- ried by the distortion part of the deformation, while the dil atation part carries only the rest-mass energy. The strain energy density of the electrom agnetic energy-momentum stress tensor is calculated. The dilatation energy density (the rest-mass energy density of the photon is found to be 0 as expected. The transverse dis tortion energy density is found to include a longitudinal electromagnetic energy fl ux term, from the Poynting vector, that is massless as it is due to distortion, not dilatation, of the spacetime con- tinuum. However, because this energy flux is along the direct ion of propagation (i.e. longitudinal, it gives rise to the particle aspect of the el ectromagnetic field, the photon.

  20. Energy and direction distribution of neutrons in workplace fields: Implication of the results from the EVIDOS project for the set-up of simulated workplace fields

    International Nuclear Information System (INIS)

    Luszik-Bhadra, M.; Lacoste, V.; Reginatto, M.; Zimbal, A.

    2007-01-01

    Workplace neutron spectra from nuclear facilities obtained within the European project EVIDOS are compared with those of the simulated workplace fields CANEL and SIGMA and fields set-up with radionuclide sources at the PTB. Contributions of neutrons to ambient dose equivalent and personal dose equivalent are given in three energy intervals (for thermal, intermediate and fast neutrons) together with the corresponding direction distribution, characterised by three different types of distributions (isotropic, weakly directed and directed). The comparison shows that none of the simulated workplace fields investigated here can model all the characteristics of the fields observed at power reactors. (authors)

  1. Magnetic field-dependent of binding energy in GaN/InGaN/GaN spherical QDQW nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    El Ghazi, Haddou, E-mail: hadghazi@gmail.com [Solid State Laboratory, Faculty of science, Dhar EL Mehrez, BP 1796 Fes-Atlas (Morocco); Special mathematics, CPGE Kénitra, Chakib Arsalane Street (Morocco); Jorio, Anouar; Zorkani, Izeddine [Solid State Laboratory, Faculty of science, Dhar EL Mehrez, BP 1796 Fes-Atlas (Morocco)

    2013-10-15

    Simultaneous study of magnetic field and impurity's position effects on the ground-state shallow-donor binding energy in GaN|InGaN|GaN (core|well|shell) spherical quantum dot–quantum well (SQDQW) as a function of the ratio of the inner and the outer radius is reported. The calculations are investigated within the framework of the effective-mass approximation and an infinite deep potential describing the quantum confinement effect. A Ritz variational approach is used taking into account of the electron-impurity correlation and the magnetic field effect in the trial wave-function. It appears that the binding energy depends strongly on the external magnetic field, the impurity's position and the structure radius. It has been found that: (i) the magnetic field effect is more marked in large layer than in thin layer and (ii) it is more pronounced in the spherical layer center than in its extremities.

  2. Production from Giant Gas Fields in Norway and Russia and Subsequent Implications for European Energy Security

    International Nuclear Information System (INIS)

    Soederbergh, Bengt

    2010-01-01

    The International Energy Agency (IEA) expects total natural gas output in the EU to decrease from 216 billion cubic meters per year (bcm/year) in 2006 to 90 bcm/year in 2030. For the same period, EU demand for natural gas is forecast to increase rapidly. In 2006 demand for natural gas in the EU amounted to 532 bcm/year. By 2030, it is expected to reach 680 bcm/year. As a consequence, the widening gap between EU production and consumption requires a 90% increase of import volumes between 2006 and 2030. The main sources of imported gas for the EU are Russia and Norway. Between them they accounted for 62% of the EU's gas imports in 2006. The objective of this thesis is to assess the potential future levels of gas supplies to the EU from its two main suppliers, Norway and Russia. Scenarios for future natural gas production potential for Norway and Russia have been modeled utilizing a bottom-up approach, building field-by-field, and individual modeling has been made for giant and semi-giant gas fields. In order to forecast the production profile for an individual giant natural gas field a Giant Gas Field Model (GGF-model) has been developed. The GGF-model has also been applied to production from an aggregate of fields, such as production from small fields and undiscovered resources. Energy security in the EU is heavily dependent on gas supplies from a relatively small number of giant gas fields. In Norway almost all production originates from 18 fields of which 9 can be considered as giant fields. In Russia 36 giant fields account for essentially all gas production. There is limited potential for increased gas exports from Norway to the EU, and all of the scenarios investigated show Norwegian gas production in decline by 2030. Norwegian pipeline gas exports to the EU may even be, by 2030, 20 bcm/year lower than today's level. The maximum increase in exports of Russian gas supplies to the EU amount to only 45% by 2030. In real numbers this means a mere increase of about

  3. Dependence of Interaction Free Energy between Solutes on an External Electrostatic Field

    Directory of Open Access Journals (Sweden)

    Pei-Kun Yang

    2013-07-01

    Full Text Available To explore the athermal effect of an external electrostatic field on the stabilities of protein conformations and the binding affinities of protein-protein/ligand interactions, the dependences of the polar and hydrophobic interactions on the external electrostatic field, −Eext, were studied using molecular dynamics (MD simulations. By decomposing Eext into, along, and perpendicular to the direction formed by the two solutes, the effect of Eext on the interactions between these two solutes can be estimated based on the effects from these two components. Eext was applied along the direction of the electric dipole formed by two solutes with opposite charges. The attractive interaction free energy between these two solutes decreased for solutes treated as point charges. In contrast, the attractive interaction free energy between these two solutes increased, as observed by MD simulations, for Eext = 40 or 60 MV/cm. Eext was applied perpendicular to the direction of the electric dipole formed by these two solutes. The attractive interaction free energy was increased for Eext = 100 MV/cm as a result of dielectric saturation. The force on the solutes along the direction of Eext computed from MD simulations was greater than that estimated from a continuum solvent in which the solutes were treated as point charges. To explore the hydrophobic interactions, Eext was applied to a water cluster containing two neutral solutes. The repulsive force between these solutes was decreased/increased for Eext along/perpendicular to the direction of the electric dipole formed by these two solutes.

  4. Magnetic field effect on the ground-state binding energy in InGaN/GaN parabolic QWW

    International Nuclear Information System (INIS)

    El Ghazi, Haddou; Jorio, Anouar; Zorkani, Izeddine

    2013-01-01

    Within the framework of the effective mass scheme, the ground-state binding energy of hydrogenic shallow-donor impurity in wurtzite (WZ) (In,Ga)N/GaN parabolic transversal-section quantum-well wire (PQWW) subjected to magnetic field is investigated. The finite-difference method within the quasi-one-dimensional effective potential model is used. A cylindrical QWW effective radius is introduced to describe the lateral confinement strength. The results show that: (i) the binding energy is the largest for the impurity located at a point corresponding to the largest electron probability density and (ii) it increases with increasing external magnetic field

  5. Magnetic field effect on the ground-state binding energy in InGaN/GaN parabolic QWW

    Energy Technology Data Exchange (ETDEWEB)

    El Ghazi, Haddou, E-mail: hadghazi@gmail.com [LPS, Faculty of sciences, Dhar EL Mehrez, B.P 1796 Atlas Fez (Morocco); Specials Mathematics, CPGE Kénitra, Chakib Arsalane Street, Kénitra (Morocco); Jorio, Anouar; Zorkani, Izeddine [LPS, Faculty of sciences, Dhar EL Mehrez, B.P 1796 Atlas Fez (Morocco)

    2013-07-15

    Within the framework of the effective mass scheme, the ground-state binding energy of hydrogenic shallow-donor impurity in wurtzite (WZ) (In,Ga)N/GaN parabolic transversal-section quantum-well wire (PQWW) subjected to magnetic field is investigated. The finite-difference method within the quasi-one-dimensional effective potential model is used. A cylindrical QWW effective radius is introduced to describe the lateral confinement strength. The results show that: (i) the binding energy is the largest for the impurity located at a point corresponding to the largest electron probability density and (ii) it increases with increasing external magnetic field.

  6. Materials development and field demonstration of high-recycled-content concrete for energy-efficient building construction; FINAL

    International Nuclear Information System (INIS)

    Ostowari, Ken; Nosson, Ali

    2000-01-01

    The project developed high-recycled-content concrete material with balanced structural and thermal attributes for use in energy-efficient building construction. Recycled plastics, tire, wool, steel and concrete were used as replacement for coarse aggregates in concrete and masonry production. With recycled materials the specific heat and thermal conductivity of concrete could be tailored to enhance the energy-efficiency of concrete buildings. A comprehensive field project was implemented which confirmed the benefits of high-recycled-content concrete for energy-efficient building construction

  7. Complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

    CERN Document Server

    Bilski, P; D'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

    2006-01-01

    This report outlines the research needs and research activities within Europe to develop new and improved methods and techniques for the characterization of complex radiation fields at workplaces around high-energy accelerators and the next generation of thermonuclear fusion facilities under the auspices of the COordinated Network for RAdiation Dosimetry (CONRAD) project funded by the European Commission.

  8. On the energy-momentum tensors for field theories in spaces with affine connection and metric

    International Nuclear Information System (INIS)

    Manoff, S.

    1991-01-01

    Generalized covariant Bianchi type identities are obtained and investigated for Lagrangian densities, depending on co- and contravariant tensor fields and their first and second covariant derivatives in spaces with affine connection and metric (L n -space). The notions of canonical, generalized canonical, symmetric and variational energy-momentum tensor are introduced and necessary and sufficient conditions for the existence of the symmetric energy-momentum tensor as a local conserved quantity are obtained. 19 refs.; 1 tab

  9. Personal dosimetry in a mixed field of high energy muons and neutrons

    International Nuclear Information System (INIS)

    Cossairt, J.D.; Elwyn, A.J.

    1986-11-01

    High energy accelerators quite often emit muons. These particles behave in matter as would heavy electrons and are thus difficult to attenuate with shielding in many situations. Hence, these muons can be a source of radiation exposure to personnel and suitable methods of measuring the absorbed dose received to these people is obviously required. In practical situations, such muon radiation fields are often mixed with neutrons, well-known to be an even more troublesome particle species with respect to dosimetry. In this paper, we report on fluence measurements made in such a mixed radiation field and a comparison of dosimeter responses. We conclude that commercial self-reading dosimeters and film badges provided an adequate measure of the absorbed dose due to muons

  10. Portable instrument for measuring neutron energy spectra and neutron dose in a mixed n-γ field

    International Nuclear Information System (INIS)

    Daniels, C. J.; Silberberg, J. L.

    1980-01-01

    A portable high-speed neutron spectrometer consists of an organic scintillator, a true zero-crossing pulse shape discriminator, a 1 MHZ conversion-rate multichannel analyzer, an 8-bit microcomputer, and appropriate displays. The device can be used to measure neutron energy spectra and kerma rate in intense n- gamma radiation fields in which the neutron energy is from 5 to 15 MEV

  11. The zero-point field. On the search for the cosmic basic energy

    International Nuclear Information System (INIS)

    McTaggart, L.

    2007-02-01

    Does an inexhaustable energy source exist from which all life is fed? A form of energy, which penetrates all dead and living expression forms of life? Does a logical, scientific explanation exist for parapsychological phenomena like clairvoyance, telepathy, ghost healing, synchronicity, and a model for the mode of action of homeopathy? Do serious researchers and scientific studies to be token in ernest exist, which not only deal with this questions but also have found answers? During eight years the British scientific journalist Lynne McTaggart has researched. ''Teh zero-point field'' is the result of numerous speeches with renowned physicists, biophysicists, neuroscientists, biologist, and consciousness researchers on the whole world, which have independently discovered phenomena, which are combined like puzzle pieces to a fascinating total picture.

  12. Classical dynamics and localization of resonances in the high-energy region of the hydrogen atom in crossed fields.

    Science.gov (United States)

    Schweiner, Frank; Main, Jörg; Cartarius, Holger; Wunner, Günter

    2015-01-01

    When superimposing the potentials of external fields on the Coulomb potential of the hydrogen atom, a saddle point (called the Stark saddle point) appears. For energies slightly above the saddle point energy, one can find classical orbits that are located in the vicinity of this point. We follow those so-called quasi-Penning orbits to high energies and field strengths, observing structural changes and uncovering their bifurcation behavior. By plotting the stability behavior of those orbits against energy and field strength, the appearance of a stability apex is reported. A cusp bifurcation, located in the vicinity of the apex, will be investigated in detail. In this cusp bifurcation, another orbit of similar shape is found. This orbit becomes completely stable in the observed region of positive energy, i.e., in a region of parameter space, where the Kepler-like orbits located around the nucleus are already unstable. By quantum mechanically exact calculations, we prove the existence of signatures in quantum spectra belonging to those orbits. Husimi distributions are used to compare quantum-Poincaré sections with the extension of the classical torus structure around the orbits. Since periodic orbit theory predicts that each classical periodic orbit contributes an oscillating term to photoabsorption spectra, we finally give an estimation for future experiments, which could verify the existence of the stable orbits.

  13. A field study of energy consumption in wheat production in Canterbury, New Zealand

    International Nuclear Information System (INIS)

    Safa, M.; Samarasinghe, S.; Mohssen, M.

    2011-01-01

    Research highlights: → We determine the energy use in wheat production base on farm operation and energy sources on dryland and irrigated farms in New Zealand. → The study estimate and compare different energy inputs in wheat production using around 40 samples. → The results show fertilizer is the most important energy inputs on farms. → The significant correlation between energy use and wheat production must be taken into consideration. -- Abstract: This paper examines the energy consumption of wheat production in Canterbury province, New Zealand. This study was conducted within a 35,300 ha of irrigated and dry land wheat fields in Canterbury in the 2007-2008 harvest year. Total energy consumption for wheat production was estimated at 25,600 MJ/ha. On average, fertilizer and electricity were used more than other energy sources, at around 10,654 (47%) and 4870 (22%) MJ/ha, respectively. The energy consumption for wheat in irrigated farming systems and dry land farming systems was estimated at 25,600 and 17,458 MJ/ha, respectively. The main source of energy in both systems is fertilizer and it consumed around 10,188 and 11,429 MJ/ha for irrigated farming and dry land farming, respectively. The average operational energy consumption was 7997 MJ/ha. In irrigated farming system, operational energy was approximately three times more than that in dry land farming. The maximum energy consumed in operational wheat production was about 7762 (71%) MJ/ha for irrigated farming systems, including irrigation, and it was 1451 (46%) MJ/ha for dry land farming including tillage. The average values of estimated output to input energy ratio for wheat in irrigated and dry land farming systems were 11.5 and 15.1, respectively.

  14. Simulations of ultra-high energy cosmic rays in the local Universe and the origin of cosmic magnetic fields

    Science.gov (United States)

    Hackstein, S.; Vazza, F.; Brüggen, M.; Sorce, J. G.; Gottlöber, S.

    2018-04-01

    We simulate the propagation of cosmic rays at ultra-high energies, ≳1018 eV, in models of extragalactic magnetic fields in constrained simulations of the local Universe. We use constrained initial conditions with the cosmological magnetohydrodynamics code ENZO. The resulting models of the distribution of magnetic fields in the local Universe are used in the CRPROPA code to simulate the propagation of ultra-high energy cosmic rays. We investigate the impact of six different magneto-genesis scenarios, both primordial and astrophysical, on the propagation of cosmic rays over cosmological distances. Moreover, we study the influence of different source distributions around the Milky Way. Our study shows that different scenarios of magneto-genesis do not have a large impact on the anisotropy measurements of ultra-high energy cosmic rays. However, at high energies above the Greisen-Zatsepin-Kuzmin (GZK)-limit, there is anisotropy caused by the distribution of nearby sources, independent of the magnetic field model. This provides a chance to identify cosmic ray sources with future full-sky measurements and high number statistics at the highest energies. Finally, we compare our results to the dipole signal measured by the Pierre Auger Observatory. All our source models and magnetic field models could reproduce the observed dipole amplitude with a pure iron injection composition. Our results indicate that the dipole is observed due to clustering of secondary nuclei in direction of nearby sources of heavy nuclei. A light injection composition is disfavoured, since the increase in dipole angular power from 4 to 8 EeV is too slow compared to observation by the Pierre Auger Observatory.

  15. Noether symmetries, energy-momentum tensors, and conformal invariance in classical field theory

    International Nuclear Information System (INIS)

    Pons, Josep M.

    2011-01-01

    In the framework of classical field theory, we first review the Noether theory of symmetries, with simple rederivations of its essential results, with special emphasis given to the Noether identities for gauge theories. With this baggage on board, we next discuss in detail, for Poincare invariant theories in flat spacetime, the differences between the Belinfante energy-momentum tensor and a family of Hilbert energy-momentum tensors. All these tensors coincide on shell but they split their duties in the following sense: Belinfante's tensor is the one to use in order to obtain the generators of Poincare symmetries and it is a basic ingredient of the generators of other eventual spacetime symmetries which may happen to exist. Instead, Hilbert tensors are the means to test whether a theory contains other spacetime symmetries beyond Poincare. We discuss at length the case of scale and conformal symmetry, of which we give some examples. We show, for Poincare invariant Lagrangians, that the realization of scale invariance selects a unique Hilbert tensor which allows for an easy test as to whether conformal invariance is also realized. Finally we make some basic remarks on metric generally covariant theories and classical field theory in a fixed curved background.

  16. Novel string field theory with also negative energy constituents/objects gives Veneziano amplitude

    Science.gov (United States)

    Nielsen, H. B.; Ninomiya, M.

    2018-02-01

    We have proposed a new type of string field theory. The main point of the present article is to cure some technical troubles: missing two out three terms in Veneziano amplitude. Our novel string field theory, describes a theory with many strings in terms of "objects", which are not exactly, but close to Charles Thorn's string bits. The new point is that the objects in terms of which the universe states are constructed, and which have an essentially 26-momentum variable called J μ , can have the energy J 0 be also negative as well as positive. We get a long way in deriving in this model the Veneziano model and obtain all the three terms needed for a four point amplitude. This result strongly indicates that our novel string field theory is indeed string theory.

  17. 4.5 Tesla magnetic field reduces range of high-energy positrons -- Potential implications for positron emission tomography

    International Nuclear Information System (INIS)

    Wirrwar, A.; Vosberg, H.; Herzog, H.; Halling, H.; Weber, S.; Mueller-Gaertner, H.W.; Forschungszentrum Juelich GmbH

    1997-01-01

    The authors have theoretically and experimentally investigated the extent to which homogeneous magnetic fields up to 7 Tesla reduce the spatial distance positrons travel before annihilation (positron range). Computer simulations of a noncoincident detector design using a Monte Carlo algorithm calculated the positron range as a function of positron energy and magnetic field strength. The simulation predicted improvements in resolution, defined as full-width at half-maximum (FWHM) of the line-spread function (LSF) for a magnetic field strength up to 7 Tesla: negligible for F-18, from 3.35 mm to 2.73 mm for Ga-68 and from 3.66 mm to 2.68 mm for Rb-82. Also a substantial noise suppression was observed, described by the full-width at tenth-maximum (FWTM) for higher positron energies. The experimental approach confirmed an improvement in resolution for Ga-68 from 3.54 mm at 0 Tesla to 2.99 mm FWHM at 4.5 Tesla and practically no improvement for F-18 (2.97 mm at 0 Tesla and 2.95 mm at 4.5 Tesla). It is concluded that the simulation model is appropriate and that a homogeneous static magnetic field of 4.5 Tesla reduces the range of high-energy positrons to an extent that may improve spatial resolution in positron emission tomography

  18. Stress fields and energy of disclination-type defects in zones of localized elastic distortions

    Science.gov (United States)

    Sukhanov, Ivan I.; Tyumentsev, Alexander N.; Ditenberg, Ivan A.

    2016-11-01

    This paper studies theoretically the elastically deformed state and analyzes deformation mechanisms in nanocrystals in the zones of localized elastic distortions and related disclination-type defects, such as dipole, quadrupole and multipole of partial disclinations. Significant differences in the energies of quadrupole and multipole configurations in comparison with nanodipole are revealed. The mechanism of deformation localization in the field of elastic distortions is proposed, which is a quasi-periodic sequence of formation and relaxation of various disclination ensembles with a periodic change in the energy of the defect.

  19. Numerical analyses of magnetic field and force in toroidal superconducting magnetic energy storage using unit coils (abstract)

    International Nuclear Information System (INIS)

    Kanamaru, Y.; Nakayama, T.; Amemiya, Y.

    1997-01-01

    Superconducting magnetic energy storage (SMES) is more useful than other systems of electric energy storage because of its larger amounts of stored energy and its higher efficiency. There are two types of SMES. One is the solenoid type and the other is the toroidal type. Some models of solenoid-type SMES are designed in the U.S. and in Japan. But the large scale SMES causes a high magnetic field in the living environment, and causes the erroneous operation of electronic equipment. The authors studied some suitable designs of magnetic shielding for the solenoidal-type SMES to reduce the magnetic field in the living environment. The toiroidal type SMES is studied in this article. The magnetic leakage flux of the toiroidal-type SMES is generally lower than that of the solenoid-type SMES. The toroidal-type SMES is constructed of unit coils, which are convenient for construction. The magnetic leakage flux occurs between unit coils. The electromagnetic force of the coils is very strong. Therefore analyses of the leakage flux and electromagnetic force are important to the design of SMES. The authors studied the number, radius, and length of unit coils. The storage energy is 5 G Wh. The numerical analyses of magnetic fields in the toroidal type SMES are obtained by analytical solutions. copyright 1997 American Institute of Physics

  20. Energy law preserving C0 finite element schemes for phase field models in two-phase flow computations

    International Nuclear Information System (INIS)

    Hua Jinsong; Lin Ping; Liu Chun; Wang Qi

    2011-01-01

    Highlights: → We study phase-field models for multi-phase flow computation. → We develop an energy-law preserving C0 FEM. → We show that the energy-law preserving method work better. → We overcome unphysical oscillation associated with the Cahn-Hilliard model. - Abstract: We use the idea in to develop the energy law preserving method and compute the diffusive interface (phase-field) models of Allen-Cahn and Cahn-Hilliard type, respectively, governing the motion of two-phase incompressible flows. We discretize these two models using a C 0 finite element in space and a modified midpoint scheme in time. To increase the stability in the pressure variable we treat the divergence free condition by a penalty formulation, under which the discrete energy law can still be derived for these diffusive interface models. Through an example we demonstrate that the energy law preserving method is beneficial for computing these multi-phase flow models. We also demonstrate that when applying the energy law preserving method to the model of Cahn-Hilliard type, un-physical interfacial oscillations may occur. We examine the source of such oscillations and a remedy is presented to eliminate the oscillations. A few two-phase incompressible flow examples are computed to show the good performance of our method.

  1. Magnetic field systems employing a superconducting D.C. field coil

    International Nuclear Information System (INIS)

    Bartram, T.C.; Hazell, P.A.

    1977-01-01

    Method and equipment for transferring energy to or from a direct-current superconducting field coil to change the magnetic field generated by the coil in which a second direct-current superconducting coil is used as a storage coil, and energy transfer between the field coil and the storage coil is effected automatically in dependence upon a control program. Preferably, the control program acts upon a variable transformer which is coupled by respective rectifier/inverters to the field and storage coils and also serves for intital supply of energy to the coils

  2. Healing of damaged metal by a pulsed high-energy electromagnetic field

    Science.gov (United States)

    Kukudzhanov, K. V.; Levitin, A. L.

    2018-04-01

    The processes of defect (intergranular micro-cracks) transformation are investigated for metal samples in a high-energy short-pulsed electromagnetic field. This investigation is based on a numerical coupled model of the impact of high-energy electromagnetic field on the pre-damaged thermal elastic-plastic material with defects. The model takes into account the melting and evaporation of the metal and the dependence of its physical and mechanical properties on the temperature. The system of equations is solved numerically by finite element method with an adaptive mesh using the arbitrary Euler–Lagrange method. The calculations show that the welding of the crack and the healing of micro-defects under treatment by short pulses of the current takes place. For the macroscopic description of the healing process, the healing and damage parameters of the material are introduced. The healing of micro-cracks improves the material healing parameter and reduces its damage. The micro-crack shapes practically do not affect the time-dependence of the healing and damage under the treatment by the current pulses. These changes are affected only by the value of the initial damage of the material and the initial length of the micro-crack. The time-dependence of the healing and the damage is practically the same for all different shapes of micro-defects, provided that the initial lengths of micro-cracks and the initial damages are the same for these different shapes of defects.

  3. Is the effective field theory of dark energy effective?

    Energy Technology Data Exchange (ETDEWEB)

    Linder, Eric V. [Berkeley Center for Cosmological Physics and Berkeley Lab, University of California, New Campbell Hall 341, Berkeley, CA, 94720 (United States); Sengör, Gizem; Watson, Scott, E-mail: evlinder@lbl.gov, E-mail: gsengor@syr.edu, E-mail: gswatson@syr.edu [Department of Physics, Syracuse University, 201 Physics Building, Syracuse, NY, 13244 (United States)

    2016-05-01

    The effective field theory of cosmic acceleration systematizes possible contributions to the action, accounting for both dark energy and modifications of gravity. Rather than making model dependent assumptions, it includes all terms, subject to the required symmetries, with four (seven) functions of time for the coefficients. These correspond respectively to the Horndeski and general beyond Horndeski class of theories. We address the question of whether this general systematization is actually effective, i.e. useful in revealing the nature of cosmic acceleration when compared with cosmological data. The answer is no and yes: there is no simple time dependence of the free functions —assumed forms in the literature are poor fits, but one can derive some general characteristics in early and late time limits. For example, we prove that the gravitational slip must restore to general relativity in the de Sitter limit of Horndeski theories, and why it doesn't more generally. We also clarify the relation between the tensor and scalar sectors, and its important relation to observations; in a real sense the expansion history H ( z ) or dark energy equation of state w ( z ) is 1/5 or less of the functional information! In addition we discuss the de Sitter, Horndeski, and decoupling limits of the theory utilizing Goldstone techniques.

  4. The heart field effect: Synchronization of healer-subject heart rates in energy therapy.

    Science.gov (United States)

    Bair, Christine Caldwell

    2008-01-01

    Recent health research has focused on subtle energy and vibrational frequency as key components of health and healing. In particular, intentional direction of bioenergy is receiving increasing scientific attention. This study investigates the effect of the healer's electromagnetic (EM) heart field upon subjects during energy healing as measured by synchronization of heart rates and scores on a Subjective Units of Distress (SUD) scale and a Profile of Mood States (POMS) inventory. A nonequivalent pretest-posttest design was used based on heart rate comparisons between healer and subject and correlated with pre-and posttest SUD and POMS scores. Subjects included those who sat within the 3- to 4-foot "strong" range of the independent variable, the healer's heart field, while performing self-application of WHEE (the wholistic hybrid derived from EMDR [eye movement desensitization and reprocessing], and EFT [emotional freedom technique]), a meridian-based tapping technique (n=50); and those who performed the same process beyond the 15- to 18-foot range of the healer's EM heart field (n=41). The dependent variables were heart rate, SUD, and POMS inventory. All subjects completed these measures within 1 hour. Study results showed statistically significant heart-rate synchronization with the intervention population. In addition, SUD and POMS scores demonstrated considerably more improvement than in the control population, indicating additional benefit beyond the meridian-based therapies, such as WHEE, alone. Additional findings and future research recommendations are presented in this article.

  5. Combined cosmological tests of a bivalent tachyonic dark energy scalar field model

    International Nuclear Information System (INIS)

    Keresztes, Zoltán; Gergely, László Á.

    2014-01-01

    A recently investigated tachyonic scalar field dark energy dominated universe exhibits a bivalent future: depending on initial parameters can run either into a de Sitter exponential expansion or into a traversable future soft singularity followed by a contraction phase. We also include in the model (i) a tiny amount of radiation, (ii) baryonic matter (Ω b h 2  = 0.022161, where the Hubble constant is fixed as h = 0.706) and (iii) cold dark matter (CDM). Out of a variety of six types of evolutions arising in a more subtle classification, we identify two in which in the past the scalar field effectively degenerates into a dust (its pressure drops to an insignificantly low negative value). These are the evolutions of type IIb converging to de Sitter and type III hitting the future soft singularity. We confront these background evolutions with various cosmological tests, including the supernova type Ia Union 2.1 data, baryon acoustic oscillation distance ratios, Hubble parameter-redshift relation and the cosmic microwave background (CMB) acoustic scale. We determine a subset of the evolutions of both types which at 1σ confidence level are consistent with all of these cosmological tests. At perturbative level we derive the CMB temperature power spectrum to find the best agreement with the Planck data for Ω CDM  = 0.22. The fit is as good as for the ΛCDM model at high multipoles, but the power remains slightly overestimated at low multipoles, for both types of evolutions. The rest of the CDM is effectively generated by the tachyonic field, which in this sense acts as a combined dark energy and dark matter model

  6. Uddannelse og Entrepreneurship

    DEFF Research Database (Denmark)

    Blenker, Per; Dreisler, Poul; Færgemann, Helle Maibom

    2004-01-01

    Innovation og entrepreneurship står højt på den politiske dagsorden og universiteterne er tiltænkt en central rolle i denne proces, hvis mål er at skabe større vækst og øget velfærd i samfundet. Et af midlerne har været at motivere til større samarbejde om forskning og uddannelse i samspil mellem...

  7. On the zero point energy of the electromagnetic field in the presence of material media

    International Nuclear Information System (INIS)

    Ferreira, L.A.

    1980-12-01

    The Van der Waals force between two semi-infinite material media separated by a piece of a third material is calculated. In this calculation, a generalization of some works on this theme is made, considering the radiation field delay effect, and impose no kind of electric and magnetic permeability dependence on the field frequency. The zero point energy of electromagnetic field in the presence of rectangular cavities with perfectly conducting walls (epsilon →i infinite) and/or infinitely permeable walls (μ→ infinite), is also calculated. Two kinds of regularization are made. In view of the results obtained modifications in the Casimir's model for the electron are suggested [pt

  8. Ordinance of 18 January 1984 on definitions and licences in the atomic energy field

    International Nuclear Information System (INIS)

    1984-01-01

    This Ordinance (RS 732.11) repeals the 1978 Ordinance on definitions and licences in the atomic energy field with the exception of Annexes 2 and 3 and concerns in particular, the licensing procedure for atomic installations. It also regulates the export, import and transit of nuclear materials and equipment. (NEA) [fr

  9. Classical solutions in quantum field theory solitons and instantons in high energy physics

    CERN Document Server

    Weinberg, Erick J

    2012-01-01

    Classical solutions play an important role in quantum field theory, high energy physics and cosmology. Real-time soliton solutions give rise to particles, such as magnetic monopoles, and extended structures, such as domain walls and cosmic strings, that have implications for early universe cosmology. Imaginary-time Euclidean instantons are responsible for important nonperturbative effects, while Euclidean bounce solutions govern transitions between metastable states. Written for advanced graduate students and researchers in elementary particle physics, cosmology and related fields, this book brings the reader up to the level of current research in the field. The first half of the book discusses the most important classes of solitons: kinks, vortices and magnetic monopoles. The cosmological and observational constraints on these are covered, as are more formal aspects, including BPS solitons and their connection with supersymmetry. The second half is devoted to Euclidean solutions, with particular emphasis on ...

  10. Zero-point energy of massless scalar fields in the presence of soft and semihard boundaries in D dimensions

    International Nuclear Information System (INIS)

    Caruso, F.; De Paola, R.; Svaiter, N.F.

    1998-06-01

    The renormalized energy density of a massless scalar field defined in a D-dimensional flat spacetime is computed in the presence of 'soft'and 'semihard'boundaries, modeled by some smoothly increasing potential functions. The sign of the renormalized energy densities for these different confining situations is investigated. The dependence of this energy on D for the cases of 'hard'and 'soft/semihard'boundaries area compared. (author)

  11. Trade and agriculture policy conditions for the use of plant oils in the energy field

    International Nuclear Information System (INIS)

    Joerdens, R.

    1994-01-01

    Preservation of resources, ecology and agricultural policy supply the most important argument for an increased use of raw materials which grow again. Regenerative raw materials are at present grown on about 2.5% of the arable land area in Germany, where production for the chemical technical field is to the fore. Access to the energy field is, however, difficult due to the considerable economic deficit compared to fossil fuels. Possibilities of use exist mainly in heating plant and in Diesel engines. (BWI) [de

  12. Interacting new agegraphic tachyon, K-essence and dilaton scalar field models of dark energy in non-flat universe

    Energy Technology Data Exchange (ETDEWEB)

    Karami, K., E-mail: KKarami@uok.ac.i [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Khaledian, M.S.; Felegary, F.; Azarmi, Z. [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of)

    2010-03-29

    We study the correspondence between the tachyon, K-essence and dilaton scalar field models with the interacting new agegraphic dark energy model in the non-flat FRW universe. We reconstruct the potentials and the dynamics for these scalar field models, which describe accelerated expansion of the universe.

  13. Interacting new agegraphic tachyon, K-essence and dilaton scalar field models of dark energy in non-flat universe

    International Nuclear Information System (INIS)

    Karami, K.; Khaledian, M.S.; Felegary, F.; Azarmi, Z.

    2010-01-01

    We study the correspondence between the tachyon, K-essence and dilaton scalar field models with the interacting new agegraphic dark energy model in the non-flat FRW universe. We reconstruct the potentials and the dynamics for these scalar field models, which describe accelerated expansion of the universe.

  14. Experimental investigation and crystal-field modeling of Er{sup 3+} energy levels in GSGG crystal

    Energy Technology Data Exchange (ETDEWEB)

    Gao, J.Y., E-mail: jygao1985@sina.com [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Sun, D.L.; Zhang, Q.L. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Wang, X.F. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Liu, W.P.; Luo, J.Q.; Sun, G.H.; Yin, S.T. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-06-25

    The Er{sup 3+}-doped Gd{sub 3}Sc{sub 2}Ga{sub 3}O{sub 12} (Er{sup 3+}:GSGG) single crystal, a excellent medium of the mid-infrared and anti-radiation solid state laser pumped by laser diode, was grown by Czochralski method successfully. The absorption spectra were measured and analyzed in a wider spectral wavelength range of 350–1700 nm at different temperatures of 7.6, 77, 200 and 300 K. The free-ions and crystal-field parameters were fitted to the experimental energy levels with the root mean square deviation of 9.86 cm{sup −1}. According to the crystal-field calculations, 124 degenerate energy levels of Er{sup 3+} in GSGG host crystals were assigned. The fitting results of free-ions and crystal-field parameters were compared with those already reported of Er{sup 3+}:YSGG. The results indicated that the free-ions parameters for Er{sup 3+} in GSGG host are similar to those in YSGG host crystals, and the crystal-field interaction of GSGG is weaker than that of YSGG, which may result in the better laser characterization of Er{sup 3+}:GSGG crystal. - Highlights: • The efficient diode-end-pumped laser crystal Er:GSGG has been grown successfully. • The absorption spectra of Er:GSGG have been measured in range of 350–1700 nm. • The fitting result is very well for the root mean square deviation is 9.86 cm{sup −1}. • The 124 levels of Er:GSGG have been assigned from the crystal-field calculations.

  15. High energy hadron dynamics based on a Stochastic-field multi-eikonal theory

    International Nuclear Information System (INIS)

    Arnold, R.C.

    1977-06-01

    Multi-eikonal theory, using a stoichastic-field representation for collective long range rapidity correlations, is developed and applied to the calculation of Regge pole parameters, high transverse momentum enhancements, and fluctuation patterns in rapidity densities. If a short-range-order model, such as the one-dimensional planar bootstrap, with only leading t-channel meson poles, is utilized as input to the multi-eikonal method, the pole spectrum is modified in three ways; promotion and renormalization of leading trajectories (suggesting an effective pomeron above unity at intermediate energies), and a proliferation of dynamical secondary trajectories, reminiscent of dual models. When transverse dimensions are included, the collective effects produce a growth with energy of large-P/sub tau/ inclusive cross-sections. Typical-event rapidity distributions, at energies of a few TeV, can be estimated by suitable approximations; the fluctuations give rise to ''domain'' patterns, which have the appearance of clusters separated by rapidity gaps. The relations between this approach to strong-interaction dynamics and a possible unification of weak, electromagnetic, and strong interactions are outlined

  16. Dark fluid: A complex scalar field to unify dark energy and dark matter

    International Nuclear Information System (INIS)

    Arbey, Alexandre

    2006-01-01

    In this article, we examine a model which proposes a common explanation for the presence of additional attractive gravitational effects - generally considered to be due to dark matter - in galaxies and in clusters, and for the presence of a repulsive effect at cosmological scales - generally taken as an indication of the presence of dark energy. We therefore consider the behavior of a so-called dark fluid based on a complex scalar field with a conserved U(1)-charge and associated to a specific potential, and show that it can at the same time account for dark matter in galaxies and in clusters, and agree with the cosmological observations and constraints on dark energy and dark matter

  17. Highly accurate analytical energy of a two-dimensional exciton in a constant magnetic field

    International Nuclear Information System (INIS)

    Hoang, Ngoc-Tram D.; Nguyen, Duy-Anh P.; Hoang, Van-Hung; Le, Van-Hoang

    2016-01-01

    Explicit expressions are given for analytically describing the dependence of the energy of a two-dimensional exciton on magnetic field intensity. These expressions are highly accurate with the precision of up to three decimal places for the whole range of the magnetic field intensity. The results are shown for the ground state and some excited states; moreover, we have all formulae to obtain similar expressions of any excited state. Analysis of numerical results shows that the precision of three decimal places is maintained for the excited states with the principal quantum number of up to n=100.

  18. Highly accurate analytical energy of a two-dimensional exciton in a constant magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Ngoc-Tram D. [Department of Physics, Ho Chi Minh City University of Pedagogy 280, An Duong Vuong Street, District 5, Ho Chi Minh City (Viet Nam); Nguyen, Duy-Anh P. [Department of Natural Science, Thu Dau Mot University, 6, Tran Van On Street, Thu Dau Mot City, Binh Duong Province (Viet Nam); Hoang, Van-Hung [Department of Physics, Ho Chi Minh City University of Pedagogy 280, An Duong Vuong Street, District 5, Ho Chi Minh City (Viet Nam); Le, Van-Hoang, E-mail: levanhoang@tdt.edu.vn [Atomic Molecular and Optical Physics Research Group, Ton Duc Thang University, 19 Nguyen Huu Tho Street, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, 19 Nguyen Huu Tho Street, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam)

    2016-08-15

    Explicit expressions are given for analytically describing the dependence of the energy of a two-dimensional exciton on magnetic field intensity. These expressions are highly accurate with the precision of up to three decimal places for the whole range of the magnetic field intensity. The results are shown for the ground state and some excited states; moreover, we have all formulae to obtain similar expressions of any excited state. Analysis of numerical results shows that the precision of three decimal places is maintained for the excited states with the principal quantum number of up to n=100.

  19. United States Department of Energy Field Office, Richland, Environmental Protection Implementation Plan, November 9, 1990--November 9, 1991

    International Nuclear Information System (INIS)

    Paasch, R.A.

    1991-09-01

    The US Department of Energy (DOE) Order 5400.1 (DOE 1988a), General Environmental Protection Program, establishes environmental protection program requirements, authorities, and responsibilities to ensure that DOE operations are in compliance with applicable federal, state and local environmental protection laws and regulations, executive orders, and internal department policies. Chapter 3 of DOE Order 5400.1 requires that each field organization prepare a plan for implementing the requirements of this order and update this plan annually. Therefore, this update to the US Department of Energy -- Richland Operations Office Environmental Protection Implementation Plan for the Hanford Site, Richland, Washington, initially prepared November 9, 1989, is being issued. Responsibility for coordinating preparation of the annual update of this plan is assigned to the US Department of Energy Field Office, Richland, Safety and Environment Division's Environmental Oversight Branch

  20. Forces in electromagnetic field and gravitational field

    OpenAIRE

    Weng, Zihua

    2008-01-01

    The force can be defined from the linear momentum in the gravitational field and electromagnetic field. But this definition can not cover the gradient of energy. In the paper, the force will be defined from the energy and torque in a new way, which involves the gravitational force, electromagnetic force, inertial force, gradient of energy, and some other new force terms etc. One of these new force terms can be used to explain why the solar wind varies velocity along the magnetic force line in...

  1. Experimental assessment of out-of-field dose components in high energy electron beams used in external beam radiotherapy.

    Science.gov (United States)

    Alabdoaburas, Mohamad M; Mege, Jean-Pierre; Chavaudra, Jean; Bezin, Jérémi Vũ; Veres, Atilla; de Vathaire, Florent; Lefkopoulos, Dimitri; Diallo, Ibrahima

    2015-11-08

    The purpose of this work was to experimentally investigate the out-of-field dose in a water phantom, with several high energy electron beams used in external beam radiotherapy (RT). The study was carried out for 6, 9, 12, and 18 MeV electron beams, on three different linear accelerators, each equipped with a specific applicator. Measurements were performed in a water phantom, at different depths, for different applicator sizes, and off-axis distances up to 70 cm from beam central axis (CAX). Thermoluminescent powder dosimeters (TLD-700) were used. For given cases, TLD measurements were compared to EBT3 films and parallel-plane ionization chamber measurements. Also, out-of-field doses at 10 cm depth, with and without applicator, were evaluated. With the Siemens applicators, a peak dose appears at about 12-15 cm out of the field edge, at 1 cm depth, for all field sizes and energies. For the Siemens Primus, with a 10 × 10 cm(²) applicator, this peak reaches 2.3%, 1%, 0.9% and 1.3% of the maximum central axis dose (Dmax) for 6, 9, 12 and 18 MeV electron beams, respectively. For the Siemens Oncor, with a 10 × 10 cm(²) applicator, this peak dose reaches 0.8%, 1%, 1.4%, and 1.6% of Dmax for 6, 9, 12, and 14 MeV, respectively, and these values increase with applicator size. For the Varian 2300C/D, the doses at 12.5 cm out of the field edge are 0.3%, 0.6%, 0.5%, and 1.1% of Dmax for 6, 9, 12, and 18 MeV, respectively, and increase with applicator size. No peak dose is evidenced for the Varian applicator for these energies. In summary, the out-of-field dose from electron beams increases with the beam energy and the applicator size, and decreases with the distance from the beam central axis and the depth in water. It also considerably depends on the applicator types. Our results can be of interest for the dose estimations delivered in healthy tissues outside the treatment field for the RT patient, as well as in studies exploring RT long-term effects.

  2. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC.

    Science.gov (United States)

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-08-01

    Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.

  3. Beam-Energy Dependence of Charge Separation along the Magnetic Field in Au +Au Collisions at RHIC

    Science.gov (United States)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-08-01

    Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au +Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.

  4. Eddy Covariance Measurements Over a Maize Field: The Contribution of Minor Flux Terms to the Energy Balance Gap

    Science.gov (United States)

    Smidt, J.; Ingwersen, J.; Streck, T.

    2015-12-01

    The lack of energy balance closure is a long-standing problem in eddy covariance (EC) measurements. The energy balance equation is defined as Rn - G = H + λE, where Rn is net radiation, G is the ground heat flux, H is the sensible heat flux and λE is the latent heat flux. In most cases of energy imbalance, either Rn is overestimated or the ground heat and turbulent fluxes are underestimated. Multiple studies have shown that calculations, incorrect instrument installation/calibration and measurement errors alone do not entirely account for this imbalance. Rather, research is now focused on previously neglected sources of heat storage in the soil, biomass and air beneath the EC station. This project examined the potential of five "minor flux terms" - soil heat storage, biomass heat storage, energy consumption by photosynthesis, air heat storage and atmospheric moisture change, to further close the energy balance gap. Eddy covariance measurements were conducted at a maize (Zea mays) field in southwest Germany during summer 2014. Soil heat storage was measured for six weeks at 11 sites around the field footprint. Biomass and air heat storage were measured for six subsequent weeks at seven sites around the field footprint. Energy consumption by photosynthesis was calculated using the CO2 flux data. Evapotranspiration was calculated using the water balance method and then compared to the flux data processed with three post-closure methods: the sensible heat flux, the latent heat flux and the Bowen ratio post-closure methods. An energy balance closure of 66% was achieved by the EC station measurements over the entire investigation period. During the soil heat flux campaign, EC station closure was 74.1%, and the field footprint soil heat storage contributed 3.3% additional closure. During the second minor flux term measurement period, closure with the EC station data was 91%. Biomass heat storage resulted in 1.1% additional closure, the photosynthesis flux closed the gap

  5. The stress energy tensor of a locally supersymmetric quantum field on a curved spacetime

    International Nuclear Information System (INIS)

    Koehler, M.

    1995-04-01

    For an analogon of the free Wess-Zumino model on Ricci flat spacetimes, the relation between a conserved 'supercurrent' and the point-separated improved energy momentum tensor is investigated and a similar relation as on Minkowski space is established. The expectation value of the latter in any globally Hadamard product state is found to be a priori finite in the coincidence limit if the theory is massive. On arbitrary globally hyperbolic spacetimes the 'supercurrent' is shown to be a well defined operator valued distribution on the GNS Hilbertspace of any globally Hadamard product state. Viewed as a new field, all n-point distributions exist, giving a new example for a Wightman field on that manifold. Moreover, it is shown that this field satisfies a new wave front set spectrum condition in a nontrivial way. (orig.)

  6. Direct-write PVDF nonwoven fiber fabric energy harvesters via the hollow cylindrical near-field electrospinning process

    International Nuclear Information System (INIS)

    Liu, Z H; Pan, C T; Ou, Z Y; Lin, L W; Huang, J C

    2014-01-01

    One-dimensional piezoelectric nanomaterials have attracted great attention in recent years for their possible applications in mechanical energy scavenging devices. However, it is difficult to control the structural diameter, length, and density of these fibers fabricated by micro/nano-technologies. This work presents a hollow cylindrical near-field electrospinning (HCNFES) process to address production and performance issues encountered previously in either far-field electrospinning (FFES) or near-field electrospinning (NFES) processes. Oriented polyvinylidene fluoride (PVDF) fibers in the form of nonwoven fabric have been directly written on a glass tube for aligned piezoelectricity. Under a high in situ electrical poling field and strong mechanical stretching (the tangential speed on the glass tube collector is about 1989.3 mm s −1 ), the HCNFES process is able to uniformly deposit large arrays of PVDF fibers with good concentrations of piezoelectric β-phase. The nonwoven fiber fabric (NFF) is transferred onto a polyethylene terephthalate (PET) substrate and fixed at both ends using copper foil electrodes as a flexible textile-fiber-based PVDF energy harvester. Repeated stretching and releasing of PVDF NFF with a strain of 0.05% at 7 Hz produces a maximum peak voltage and current at 76 mV and 39 nA, respectively. (paper)

  7. High energy X-ray phase and dark-field imaging using a random absorption mask.

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Cai, Biao; Sawhney, Kawal

    2016-07-28

    High energy X-ray imaging has unique advantage over conventional X-ray imaging, since it enables higher penetration into materials with significantly reduced radiation damage. However, the absorption contrast in high energy region is considerably low due to the reduced X-ray absorption cross section for most materials. Even though the X-ray phase and dark-field imaging techniques can provide substantially increased contrast and complementary information, fabricating dedicated optics for high energies still remain a challenge. To address this issue, we present an alternative X-ray imaging approach to produce transmission, phase and scattering signals at high X-ray energies by using a random absorption mask. Importantly, in addition to the synchrotron radiation source, this approach has been demonstrated for practical imaging application with a laboratory-based microfocus X-ray source. This new imaging method could be potentially useful for studying thick samples or heavy materials for advanced research in materials science.

  8. Global Geopotential Energy & Stress Field

    DEFF Research Database (Denmark)

    Schiffer, Christian; Nielsen, S.B.

    of the oceanic lithosphere. An entire modelling of the shallow Geopotential Energy is hereby approached, not taking into account possible deeper signals but all lithospheric signals for the subsequent stress calculation. Therefore a global lithospheric density model is necessary to calculate the corresponding...... response to Geopotential Energy and the Geoid. A linearized inverse method fits a lithospheric reference model to reproduce measured data sets, such as topography and surface heat flow, while assuming isostasy and solving the steady state heat equation. A FEM code solves the equations of equilibrium...

  9. Measuring linac photon beam energy through EPID image analysis of physically wedged fields

    Energy Technology Data Exchange (ETDEWEB)

    Dawoud, S. M., E-mail: samir.dawoud@leedsth.nhs.uk; Weston, S. J.; Bond, I.; Ward, G. C.; Rixham, P. A.; Mason, J.; Huckle, A. [Department of Medical Physics and Engineering, St. James Institute of Oncology, St. James University Hospital, Leeds LS9 7TF (United Kingdom); Sykes, J. R. [Institute of Medical Physics, School of Physics, The University of Sydney, New South Wales 2006, Australia and Department of Medical Physics and Engineering, St. James Institute of Oncology, St. James University Hospital, Leeds LS9 7TF (United Kingdom)

    2014-02-15

    Purpose: Electronic portal imaging devices (EPIDs) have proven to be useful tools for measuring several parameters of interest in linac quality assurance (QA). However, a method for measuring linac photon beam energy using EPIDs has not previously been reported. In this report, such a method is devised and tested, based on fitting a second order polynomial to the profiles of physically wedged beams, where the metric of interest is the second order coefficientα. The relationship between α and the beam quality index [percentage depth dose at 10 cm depth (PDD{sub 10})] is examined to produce a suitable calibration curve between these two parameters. Methods: Measurements were taken in a water-tank for beams with a range of energies representative of the local QA tolerances about the nominal value 6 MV. In each case, the beam quality was found in terms of PDD{sub 10} for 100 × 100 mm{sup 2} square fields. EPID images of 200 × 200 mm{sup 2} wedged fields were then taken for each beam and the wedge profile was fitted in MATLAB 2010b (The MathWorks, Inc., Natick, MA). α was then plotted against PDD{sub 10} and fitted with a linear relation to produce the calibration curve. The uncertainty in α was evaluated by taking five repeat EPID images of the wedged field for a beam of 6 MV nominal energy. The consistency of measuring α was found by taking repeat measurements on a single linac over a three month period. The method was also tested at 10 MV by repeating the water-tank crosscalibration for a range of energies centered approximately about a 10 MV nominal value. Finally, the calibration curve from the test linac and that from a separate clinical machine were compared to test consistency of the method across machines in a matched fleet. Results: The relationship betweenα and PDD{sub 10} was found to be strongly linear (R{sup 2} = 0.979) while the uncertainty in α was found to be negligible compared to that associated with measuring PDD{sub 10} in the water-tank (

  10. Inference with minimal Gibbs free energy in information field theory

    International Nuclear Information System (INIS)

    Ensslin, Torsten A.; Weig, Cornelius

    2010-01-01

    Non-linear and non-Gaussian signal inference problems are difficult to tackle. Renormalization techniques permit us to construct good estimators for the posterior signal mean within information field theory (IFT), but the approximations and assumptions made are not very obvious. Here we introduce the simple concept of minimal Gibbs free energy to IFT, and show that previous renormalization results emerge naturally. They can be understood as being the Gaussian approximation to the full posterior probability, which has maximal cross information with it. We derive optimized estimators for three applications, to illustrate the usage of the framework: (i) reconstruction of a log-normal signal from Poissonian data with background counts and point spread function, as it is needed for gamma ray astronomy and for cosmography using photometric galaxy redshifts, (ii) inference of a Gaussian signal with unknown spectrum, and (iii) inference of a Poissonian log-normal signal with unknown spectrum, the combination of (i) and (ii). Finally we explain how Gaussian knowledge states constructed by the minimal Gibbs free energy principle at different temperatures can be combined into a more accurate surrogate of the non-Gaussian posterior.

  11. US Department of Energy Oak Ridge Field Office Environmental Restoration Program review

    International Nuclear Information System (INIS)

    1992-05-01

    This document summarizes the baselined FY 1993 Department of Energy Oak Ridge Field Office (DOE-OR) Environmental Restoration Program task priorities, budgets, and associated abbreviated task descriptions. Also included is a description of the approach utilized to establish priorities for the FY 1993 and FY 1994 budget process. Abbreviated task descriptions for FY 1994 are also included in priority listing. These FY 1994 tasks form the basis for the Activity Data Sheets prepared for DOE-OR that were submitted in May 1992

  12. Contribution to the Brazilian legislation in nuclear energy field

    International Nuclear Information System (INIS)

    Barbosa, Jose Alberto Maia

    2009-01-01

    Nuclear technology: to keep its domain is actually considered a differential for a country in relation to other ones, being able to represent an international threat to be contained or an aspect on technological and political valorization for those ones with recognized international credibility. Face to a raising use of new technologies in the field and the requirement asking for regulation in accordance with international safety standards, in order to assure its employment, the objective of this study was to demonstrate whether occupational and environmental radioprotection performed in our country is within radiological and nuclear safety international standards, and so it was updated and revised the Brazilian law in nuclear energy area, by comparing it with European Union, contextualized strong and weak points from national law, indicating criticisms and suggestions, in order that modifications will be able to be accomplished, aiming to its adequacy to international standards. The considered hypothesis showed that are required changes in the regulation structure in Brazilian nuclear area, aiming to the creation of a regulator agency of nuclear activities, with the purpose of assuring that the state of art and of technology, in terms of nuclear safety, to be the basis of the exercise related to their normative, control and safety assessment activities, on environment preservation, public and workers health, face to nuclear energy applications. (author)

  13. Simulation of ultra-high energy photon propagation in the geomagnetic field

    Science.gov (United States)

    Homola, P.; Góra, D.; Heck, D.; Klages, H.; PeĶala, J.; Risse, M.; Wilczyńska, B.; Wilczyński, H.

    2005-12-01

    The identification of primary photons or specifying stringent limits on the photon flux is of major importance for understanding the origin of ultra-high energy (UHE) cosmic rays. UHE photons can initiate particle cascades in the geomagnetic field, which leads to significant changes in the subsequent atmospheric shower development. We present a Monte Carlo program allowing detailed studies of conversion and cascading of UHE photons in the geomagnetic field. The program named PRESHOWER can be used both as an independent tool or together with a shower simulation code. With the stand-alone version of the code it is possible to investigate various properties of the particle cascade induced by UHE photons interacting in the Earth's magnetic field before entering the Earth's atmosphere. Combining this program with an extensive air shower simulation code such as CORSIKA offers the possibility of investigating signatures of photon-initiated showers. In particular, features can be studied that help to discern such showers from the ones induced by hadrons. As an illustration, calculations for the conditions of the southern part of the Pierre Auger Observatory are presented. Catalogue identifier:ADWG Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWG Program obtainable: CPC Program Library, Quen's University of Belfast, N. Ireland Computer on which the program has been thoroughly tested:Intel-Pentium based PC Operating system:Linux, DEC-Unix Programming language used:C, FORTRAN 77 Memory required to execute with typical data:Recipes, http://www.nr.com]. Nature of the physical problem:Simulation of a cascade of particles initiated by UHE photon passing through the geomagnetic field above the Earth's atmosphere. Method of solution: The primary photon is tracked until its conversion into ee pair or until it reaches the upper atmosphere. If conversion occurred each individual particle in the resultant preshower is checked for either bremsstrahlung radiation (electrons) or

  14. Control of the Effective Free-Energy Landscape in a Frustrated Magnet by a Field Pulse

    Science.gov (United States)

    Wan, Yuan; Moessner, Roderich

    2017-10-01

    Thermal fluctuations can lift the degeneracy of a ground state manifold, producing a free-energy landscape without accidentally degenerate minima. In a process known as order by disorder, a subset of states incorporating symmetry breaking may be selected. Here, we show that such a free-energy landscape can be controlled in a nonequilibrium setting as the slow motion within the ground state manifold is governed by the fast modes out of it. For the paradigmatic case of the classical pyrochlore X Y antiferromagnet, we show that a uniform magnetic field pulse can excite these fast modes to generate a tunable effective free-energy landscape with minima at thermodynamically unstable portions of the ground state manifold.

  15. Energy-momentum tensor in thermal strong-field QED with unstable vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, S P [Department of General and Experimental Physics, Herzen State Pedagogical University of Russia, Moyka emb. 48, 191186 St Petersburg (Russian Federation); Gitman, D M [Instituto de Fisica, Universidade de Sao Paulo, CP 66318, CEP 05315-970 Sao Paulo, SP (Brazil)], E-mail: gavrilovsergeyp@yahoo.com, E-mail: gitman@dfn.if.usp.br

    2008-04-25

    The mean value of the one-loop energy-momentum tensor in thermal QED with an electric-like background that creates particles from vacuum is calculated. The problem is essentially different from calculations of effective actions (similar to the action of Heisenberg-Euler) in backgrounds that respect the stability of vacuum. The role of a constant electric background in the violation of both the stability of vacuum and the thermal character of particle distribution is investigated. Restrictions on the electric field and the duration over which one can neglect the back-reaction of created particles are established.

  16. Energy-momentum tensor in thermal strong-field QED with unstable vacuum

    International Nuclear Information System (INIS)

    Gavrilov, S P; Gitman, D M

    2008-01-01

    The mean value of the one-loop energy-momentum tensor in thermal QED with an electric-like background that creates particles from vacuum is calculated. The problem is essentially different from calculations of effective actions (similar to the action of Heisenberg-Euler) in backgrounds that respect the stability of vacuum. The role of a constant electric background in the violation of both the stability of vacuum and the thermal character of particle distribution is investigated. Restrictions on the electric field and the duration over which one can neglect the back-reaction of created particles are established

  17. Effects of an Intense Laser Field and Hydrostatic Pressure on the Intersubband Transitions and Binding Energy of Shallow Donor Impurities in a Quantum Well

    International Nuclear Information System (INIS)

    Yesilgul, U.; Ungan, F.; Kasapoglu, E.; Sari, H.; Sökmen, I.

    2011-01-01

    We have calculated the intersubband transitions and the ground-state binding energies of a hydrogenic donor impurity in a quantum well in the presence of a high-frequency laser field and hydrostatic pressure. The calculations are performed within the effective mass approximation, using a variational method. We conclude that the laser field amplitude and the hydrostatic pressure provide an important effect on the electronic and optical properties of the quantum wells. According to the results obtained from the present work, it is deduced that (i) the binding energies of donor impurity decrease as the laser field increase, (ii) the binding energies of donor impurity increase as the hydrostatic pressure increase, (iii) the intersubband absorption coefficients shift toward lower energies as the hydrostatic pressure increases, (iv) the magnitude of absorption coefficients decrease and also shift toward higher energies as the laser field increase. It is hopeful that the obtained results will provide important improvements in device applications. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  18. The total energy-momentum tensor for electromagnetic fields in a dielectric

    Science.gov (United States)

    Crenshaw, Michael E.

    2017-08-01

    Radiation pressure is an observable consequence of optically induced forces on materials. On cosmic scales, radiation pressure is responsible for the bending of the tails of comets as they pass near the sun. At a much smaller scale, optically induced forces are being investigated as part of a toolkit for micromanipulation and nanofabrication technology [1]. A number of practical applications of the mechanical effects of light-matter interaction are discussed by Qiu, et al. [2]. The promise of the nascent nanophotonic technology for manufacturing small, low-power, high-sensitivity sensors and other devices has likely motivated the substantial current interest in optical manipulation of materials at the nanoscale, see, for example, Ref. [2] and the references therein. While substantial progress toward optical micromanipulation has been achieved, e.g. optical tweezers [1], in this report we limit our consideration to the particular issue of optically induced forces on a transparent dielectric material. As a matter of electromagnetic theory, these forces remain indeterminate and controversial. Due to the potential applications in nanotechnology, the century-old debate regarding these forces, and the associated momentums, has ramped up considerably in the physics community. The energy-momentum tensor is the centerpiece of conservation laws for the unimpeded, inviscid, incompressible flow of non-interacting particles in the continuum limit in an otherwise empty volume. The foundations of the energy-momentum tensor and the associated tensor conservation theory come to electrodynamics from classical continuum dynamics by applying the divergence theorem to a Taylor series expansion of a property density field of a continuous flow in an otherwise empty volume. The dust tensor is a particularly simple example of an energy-momentum tensor that deals with particles of matter in the continuum limit in terms of the mass density ρm, energy density ρmc 2 , and momentum density

  19. E. coli electroeradication on a closed loop circuit by using milli-, micro- and nanosecond pulsed electric fields: comparison between energy costs.

    Science.gov (United States)

    Guionet, Alexis; David, Fabienne; Zaepffel, Clément; Coustets, Mathilde; Helmi, Karim; Cheype, Cyril; Packan, Denis; Garnier, Jean-Pierre; Blanckaert, Vincent; Teissié, Justin

    2015-06-01

    One of the different ways to eradicate microorganisms, and particularly bacteria that might have an impact on health consists in the delivery of pulsed electric fields (PEFs). The technologies of millisecond (ms) or microsecond (μs) PEF are still well known and used for instance in the process of fruit juice sterilization. However, this concept is costly in terms of delivered energy which might be too expensive for some other industrial processes. Nanosecond pulsed electric fields (nsPEFs) might be an alternative at least for lower energetic cost. However, only few insights were available and stipulate a gain in cost and in efficiency as well. Using Escherichia coli, the impact of frequency and low rate on eradication and energy consumption by msPEF, μsPEF and nsPEF have been studied and compared. While a 1 log10 was reached with an energy cost of 100 and 158 kJ/L with micro- and millisecond PEFs respectively, nsPEF reached the reduction for similar energy consumption. The best condition was obtained for a 1 log10 deactivation in 0.5h, for energy consumption of 143 kJ/L corresponding to 0.04 W · h when the field was around 100 kV/cm. Improvement can also be expected by producing a generator capable to increase the electric field. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Simultaneous effects of hydrostatic pressure and electric field on impurity binding energy and polarizability in coupled InAs/GaAs quantum wires

    International Nuclear Information System (INIS)

    Tangarife, E.; Duque, C.A.

    2011-01-01

    This work is concerned with the theoretical study of the combined effects of applied electric field and hydrostatic pressure on the binding energy and impurity polarizability of a donor impurity in laterally coupled double InAs/GaAs quantum-well wires. Calculations have been made in the effective mass and parabolic band approximations and using a variational method. The results are reported for different configurations of wire and barriers widths, impurity position, and electric field and hydrostatic pressure strengths. Our results show that for symmetrical structures the binding energy is an even function of the impurity position along the growth direction of the structure. Also, we found that for hydrostatic pressure strength up to 38 kbar, the binding energy increases linearly with hydrostatic pressure, while for larger values of hydrostatic pressure the binding energy has a non-linear behavior. Finally, we found that the hydrostatic pressure can increase the coupling between the two parallel quantum-well wires. -- Research highlights: → Binding energy for donor impurity in coupled wires strongly depends on the confinement potential. → Polarizability for donor impurity in coupled wires strongly depends on the confinement potential. → Binding energy strongly depends on the direction of the applied electric field. → Polarizability strongly depends on the direction of the applied electric field. → The coupling between the two parallel wires increases with the hydrostatic pressure.

  1. Impurity binding energy of lowest-excited state in (In,Ga)N–GaN spherical QD under electric field effect

    International Nuclear Information System (INIS)

    Ghazi, Haddou El; Jorio, Anouar; Zorkani, Izeddine

    2013-01-01

    External electric field effect on the lowest-excited state in wurtzite (In,Ga)N–GaN spherical quantum dot is considered. By means of a traditional Ritz variational method within the effective-mass approximation and finite potential barrier, the lowest-excited state energy with and without the presence of the impurity is investigated. The normalized binding energy under electric field effect is also performed. Our numerical results are compared with the previous theoretical findings and show a good agreement with those concerning especially the ground-state for different semiconductors materials and different QDs-shapes

  2. Impurity binding energy of lowest-excited state in (In,Ga)N–GaN spherical QD under electric field effect

    Energy Technology Data Exchange (ETDEWEB)

    Ghazi, Haddou El, E-mail: hadghazi@gmail.com [LPS, Faculty of Sciences, Dhar EL Mehrez, B.P 1796 Atlas, Fez (Morocco); Special Mathematics, CPGE Kénitra (Morocco); Jorio, Anouar; Zorkani, Izeddine [LPS, Faculty of Sciences, Dhar EL Mehrez, B.P 1796 Atlas, Fez (Morocco)

    2013-10-01

    External electric field effect on the lowest-excited state in wurtzite (In,Ga)N–GaN spherical quantum dot is considered. By means of a traditional Ritz variational method within the effective-mass approximation and finite potential barrier, the lowest-excited state energy with and without the presence of the impurity is investigated. The normalized binding energy under electric field effect is also performed. Our numerical results are compared with the previous theoretical findings and show a good agreement with those concerning especially the ground-state for different semiconductors materials and different QDs-shapes.

  3. Zero-Magnetic-Field Spin Splitting of Polaron's Ground State Energy Induced by Rashba Spin-Orbit Interaction

    International Nuclear Information System (INIS)

    Liu Jia; Xiao Jingling

    2006-01-01

    We study theoretically the ground state energy of a polaron near the interface of a polar-polar semiconductor by considering the Rashba spin-orbit (SO) coupling with the Lee-Low-Pines intermediate coupling method. Our numerical results show that the Rashba SO interaction originating from the inversion asymmetry in the heterostructure splits the ground state energy of the polaron. The electron areal density and vector dependence of the ratio of the SO interaction to the total ground state energy or other energy composition are obvious. One can see that even without any external magnetic field, the ground state energy can be split by the Rashba SO interaction, and this split is not a single but a complex one. Since the presents of the phonons, whose energy gives negative contribution to the polaron's, the spin-splitting states of the polaron are more stable than electron's.

  4. Heart Rate and Energy Expenditure in Division I Field Hockey Players During Competitive Play.

    Science.gov (United States)

    Sell, Katie M; Ledesma, Allison B

    2016-08-01

    Sell, KM and Ledesma, AB. Heart rate and energy expenditure in Division I field hockey players during competitive play. J Strength Cond Res 30(8): 2122-2128, 2016-The purpose of this study was to quantify energy expenditure and heart rate data for Division I female field hockey players during competitive play. Ten female Division I collegiate field hockey athletes (19.8 ± 1.6 years; 166.4 ± 6.1 cm; 58.2 ± 5.3 kg) completed the Yo-Yo intermittent endurance test to determine maximal heart rate. One week later, all subjects wore a heart rate monitor during a series of 3 matches in an off-season competition. Average heart rate (AvHR), average percentage of maximal heart rate (AvHR%), peak exercise heart rate (PExHR), and percentage of maximal heart rate (PExHR%), time spent in each of the predetermined heart rate zones, and caloric expenditure per minute of exercise (kcalM) were determined for all players. Differences between positions (backs, midfielders, and forwards) were assessed. No significant differences in AvHR, AvHR%, PExHR, PExHR%, and %TM were observed between playing positions. The AvHR% and PExHR% for each position fell into zones 4 (77-93% HRmax) and 5 (>93% HRmax), respectively, and significantly more time was spent in zone 4 compared with zones 1, 2, 3, and 5 across all players (p ≤ 0.05). The kcalM reflected very heavy intensity exercise. The results of this study will contribute toward understanding the sport-specific physiological demands of women's field hockey and has specific implications for the duration and schedule of training regimens.

  5. Energy-level splitting of multicharged ions due to interaction with own radiation field

    International Nuclear Information System (INIS)

    Gajnutdinov, R.Kh.; Kalashnikov, K.K.

    1991-01-01

    The overlapping of the energy levels of He-like uranium states with identical principal quantum numbers is investigated. Results are presented of a numerical calculation of the states produced as a result of mixing of the 2s 1/2 8p 1/2 and 2p 1/2 8p 1/2 states and of the respective spectral lines. It is shown that the interaction between the ion and its own radiation field splits each of the overlapping energy levels into several sublevels. The sublevels are isolated from each to other such an extent that interference effects become insignificant. The shapes of the spectral lines differ pronouncedly from the Lorentz shape and many of the line are anomaously narrow

  6. The symmetry energy {\\boldsymbol{\\gamma }} parameter of relativistic mean-field models

    Science.gov (United States)

    Dutra, Mariana; Lourenço, Odilon; Hen, Or; Piasetzky, Eliezer; Menezes, Débora P.

    2018-05-01

    The relativistic mean-field models tested in previous works against nuclear matter experimental values, critical parameters and macroscopic stellar properties are revisited and used in the evaluation of the symmetry energy γ parameter obtained in three different ways. We have checked that, independent of the choice made to calculate the γ values, a trend of linear correlation is observed between γ and the symmetry energy ({{\\mathscr{S}}}0) and a more clear linear relationship is established between γ and the slope of the symmetry energy (L 0). These results directly contribute to the arising of other linear correlations between γ and the neutron star radii of {R}1.0 and {R}1.4, in agreement with recent findings. Finally, we have found that short-range correlations induce two specific parametrizations, namely, IU-FSU and DD-MEδ, simultaneously compatible with the neutron star mass constraint of 1.93≤slant {M}{{\\max }}/{M}ȯ ≤slant 2.05 and with the overlap band for the {L}0× {{\\mathscr{S}}}0 region, to present γ in the range of γ =0.25+/- 0.05. This work is a part of the project INCT-FNA Proc. No. 464898/2014-5 and was partially supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil under grants 300602/2009-0 and 306786/2014-1. E. P. acknowledges support from the Israel Science Foundation. O. H. acknowledges the U.S. Department of Energy Office of Science, Office of Nuclear Physics program under award number DE-FG02-94ER40818

  7. Simultaneous fitting of a potential-energy surface and its corresponding force fields using feedforward neural networks

    Science.gov (United States)

    Pukrittayakamee, A.; Malshe, M.; Hagan, M.; Raff, L. M.; Narulkar, R.; Bukkapatnum, S.; Komanduri, R.

    2009-04-01

    An improved neural network (NN) approach is presented for the simultaneous development of accurate potential-energy hypersurfaces and corresponding force fields that can be utilized to conduct ab initio molecular dynamics and Monte Carlo studies on gas-phase chemical reactions. The method is termed as combined function derivative approximation (CFDA). The novelty of the CFDA method lies in the fact that although the NN has only a single output neuron that represents potential energy, the network is trained in such a way that the derivatives of the NN output match the gradient of the potential-energy hypersurface. Accurate force fields can therefore be computed simply by differentiating the network. Both the computed energies and the gradients are then accurately interpolated using the NN. This approach is superior to having the gradients appear in the output layer of the NN because it greatly simplifies the required architecture of the network. The CFDA permits weighting of function fitting relative to gradient fitting. In every test that we have run on six different systems, CFDA training (without a validation set) has produced smaller out-of-sample testing error than early stopping (with a validation set) or Bayesian regularization (without a validation set). This indicates that CFDA training does a better job of preventing overfitting than the standard methods currently in use. The training data can be obtained using an empirical potential surface or any ab initio method. The accuracy and interpolation power of the method have been tested for the reaction dynamics of H+HBr using an analytical potential. The results show that the present NN training technique produces more accurate fits to both the potential-energy surface as well as the corresponding force fields than the previous methods. The fitting and interpolation accuracy is so high (rms error=1.2 cm-1) that trajectories computed on the NN potential exhibit point-by-point agreement with corresponding

  8. Electron energy distribution function in a low-power Hall thruster discharge and near-field plume

    Science.gov (United States)

    Tichý, M.; Pétin, A.; Kudrna, P.; Horký, M.; Mazouffre, S.

    2018-06-01

    Electron temperature and plasma density, as well as the electron energy distribution function (EEDF), have been obtained inside and outside the dielectric channel of a 200 W permanent magnet Hall thruster. Measurements were carried out by means of a cylindrical Langmuir probe mounted onto a compact fast moving translation stage. The 3D particle-in cell numerical simulations complement experiments. The model accounts for the crossed electric and magnetic field configuration in a weakly collisional regime where only electrons are magnetized. Since only the electron dynamics is of interest in this study, an artificial mass of ions corresponding to mi = 30 000me was used to ensure ions could be assumed at rest. The simulation domain is located at the thruster exit plane and does not include the cathode. The measured EEDF evidences a high-energy electron population that is superimposed onto the low energy bulk population outside the channel. Inside the channel, the EEDF is close to Maxwellian. Both the experimental and numerical EEDF depart from an equilibrium distribution at the channel exit plane, a region of high magnetic field. We therefore conclude that the fast electron group found in the experiment corresponds to the electrons emitted by the external cathode that reach the thruster discharge without experiencing collision events.

  9. Local energy decay of massive Dirac fields in the 5D Myers-Perry metric

    International Nuclear Information System (INIS)

    Daudé, Thierry; Kamran, Niky

    2012-01-01

    We consider massive Dirac fields evolving in the exterior region of a five-dimensional Myers-Perry black hole and study their propagation properties. Our main result states that the local energy of such fields decays in a weak sense at late times. We obtain this result in two steps: first, using the separability of the Dirac equation, we prove the absence of a pure point spectrum for the corresponding Dirac operator; second, using a new form of the equation adapted to the local rotations of the black hole, we show by a Mourre theory argument that the spectrum is absolutely continuous. This leads directly to our main result. (paper)

  10. Brudflader og samspil på ældreområdet

    DEFF Research Database (Denmark)

    Toft, Cammilla Bundgård; Lassen, Aske Juul; Jespersen, Astrid Pernille

    2017-01-01

    changes the relations between municipality, citizens and civil society, and how this challenges and develops the professional and voluntary boundaries, continuity in community initiatives as well as citizen-involvement. One of the focus points of the report is the projectification of care-work. While...... of voluntarism, where the continuity from project to project is ensured through a group highly engaged volunteers....

  11. Electrons in a relativistic-intensity laser field: generation of zeptosecond electromagnetic pulses and energy spectrum of the accelerated electrons

    International Nuclear Information System (INIS)

    Andreev, A A; Galkin, A L; Kalashnikov, M P; Korobkin, V V; Romanovsky, Mikhail Yu; Shiryaev, O B

    2011-01-01

    We study the motion of an electron and emission of electromagnetic waves by an electron in the field of a relativistically intense laser pulse. The dynamics of the electron is described by the Newton equation with the Lorentz force in the right-hand side. It is shown that the electrons may be ejected from the interaction region with high energy. The energy spectrum of these electrons and the technique of using the spectrum to assess the maximal intensity in the focus are analysed. It is found that electromagnetic radiation of an electron moving in an intense laser field occurs within a small angle around the direction of the electron trajectory tangent. The tangent quickly changes its direction in space; therefore, electromagnetic radiation of the electron in the far-field zone in a certain direction in the vicinity of the tangent is a short pulse with a duration as short as zeptoseconds. The calculation of the temporary and spectral distribution of the radiation field is carried out. (superintense laser fields)

  12. Experimental investigation on the effect of surface electric field in the growth of tungsten nano-tendril morphology due to low energy helium irradiation

    International Nuclear Information System (INIS)

    Woller, K.B.; Whyte, D.G.; Wright, G.M.; Brunner, D.

    2016-01-01

    The mechanisms responsible for and controlling the growth of tungsten nano-tendrils (or “fuzz”) under low-energy helium plasma exposure remain unclear. For the first time in nano-tendril experiments, the plasma sheath-produced electric field and the helium (He) ion energy have been decoupled, showing that the sheath electric field has little impact on nano-tendril growth, eliminating a possible cause for tendril growth. The well-established necessary growth conditions for W fuzz were maintained with He ion flux density Γ He  > 10 21  He m −2  s −1 , surface temperature T s  = 1273 K, He ion energy E He  = 64 eV, and He ion fluence Φ He  > 10 24  He m −2 . A grid is situated between the tungsten sample and plasma, with the grid and sample potentials independently controlled in order to control the electric field at the surface of the sample while maintaining the same incident He ion energy to the surface. A calculation of the potential profile in the drift space between the grid and sample was used to account for space charge and calculate the electric field at the surface of the sample. Tungsten fuzz formed at all electric fields tested, even near zero electric field. Also, the depth of the resulting W fuzz layer was unaltered by the electric field when compared to the calculated depth determined from an empirical growth model. The conclusion is that the sheath electric field is not necessary to cause the changes in surface morphology. - Highlights: • Surface electric field is proposed as a possible driver of tungsten fuzz growth. • A method that decouples plasma sheath electric field and ion energy is described. • Tungsten fuzz is shown to grow even without direct exposure to plasma. • Tungsten fuzz grows to the same depth with and without the plasma sheath.

  13. Quick electronics in the field of high energy physics; L'electronique rapide en physique de hautes energies

    Energy Technology Data Exchange (ETDEWEB)

    Meunier, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    An extensive technical development of particle counting in the field of high energy physics near any large modern accelerator is a necessary condition for efficient work with its beams of particles. In this review article, the basic principles of more commonly used circuite described with special emphasis on the explanation of the limits of their use. (author)Fren. [French] L'utilisation efficace des faisceaux de particules produits par les grands accelerateurs modernes a rendu necessaire un progres des techniques de comptage et de mesure electronique. Cet article decrit les principes de fonctionnement des differents circuits les plus communement utilises et explique plus particulierement les raisons de leurs limites d'utilisation. (auteur)

  14. Electron acceleration from rest to GeV energy by chirped axicon Gaussian laser pulse in vacuum in the presence of wiggler magnetic field

    Science.gov (United States)

    Kant, Niti; Rajput, Jyoti; Singh, Arvinder

    2018-03-01

    This paper presents a scheme of electron energy enhancement by employing frequency - chirped lowest order axicon focussed radially polarised (RP) laser pulse in vacuum under the influence of wiggler magnetic field. Terawatt RP laser can be focussed down to ∼5μm by an axicon optical element, which produces an intense longitudinal electric field. This unique property of axicon focused Gaussian RP laser pulse is employed for direct electron acceleration in vacuum. A linear frequency chirp increases the time duration of laser-electron interaction, whereas, the applied magnetic wiggler helps in improving the strength of ponderomotive force v→ ×B→ and periodically deflects electron in order to keep it traversing in the accelerating phase up to longer distance. Numerical simulations have been carried out to investigate the influence of laser, frequency chirp and magnetic field parameters on electron energy enhancement. It is noticed that an electron from rest can be accelerated up to GeV energy under optimized laser and magnetic field parameters. Significant enhancement in the electron energy gain of the order of 11.2 GeV is observed with intense chirped laser pulse in the presence of wiggler magnetic field of strength 96.2 kG.

  15. Experimental measurement of radiological penumbra associated with intermediate energy x-rays (1 MV) and small radiosurgery field sizes

    International Nuclear Information System (INIS)

    Keller, Brian M.; Beachey, David J.; Pignol, Jean-Philippe

    2007-01-01

    Stereotactic radiosurgery is used to treat intracranial lesions with a high degree of accuracy. At the present time, x-ray energies at or above Co-60 gamma rays are used. Previous Monte Carlo simulations have demonstrated that intermediate energy x-ray photons or IEPs (defined to be photons in the energy range of 0.2-1.2 MeV), combined with small field sizes, produce a reduced radiological penumbra leading to a sharper dose gradient, improved dose homogeneity and sparing of critical anatomy adjacent to the target volume. This hypothesis is based on the fact that, for small x-ray fields, a dose outside the treatment volume is dictated mainly by the range of electrons set into motion by x-ray photons. The purpose of this work is: (1) to produce intermediate energy x rays using a detuned medical linear accelerator (2) to characterize the energy of this beam (3) to measure the radiological penumbra for IEPs and small fields to compare with that produced by 6 MV x rays or Co-60, and (4) to compare these experimental measurements with Monte Carlo computer simulations. The maximum photon energy of our IEP x-ray spectrum was measured to be 1.2 MeV. Gafchromic EBT films (ISP Technologies, Wayne, NJ) were irradiated and read using a novel digital microscopy imaging system with high spatial resolution. Under identical irradiation conditions the measured radiological penumbra widths (80%-20% distance), for field sizes ranging from 0.3x0.3 to 4.0x4.0 cm 2 , varied from 0.3-0.77 mm (1.2 MV) and from 1.1-2.1 mm (6 MV). Even more dramatic were the differences found when comparing the 90%-10% or the 95%-5% widths, which are in fact more significant in radiotherapy. Monte Carlo simulations agreed well with the experimental findings. The reduction in radiological penumbra could be substantial for specific clinical situations such as in the treatment of an ocular melanoma abutting the macula or for the treatment of functional disorders such as trigeminal neuralgia (a nonlethal

  16. Is there a relationship between earthworm energy reserves and metal availability after exposure to field-contaminated soils?

    International Nuclear Information System (INIS)

    Beaumelle, Léa; Lamy, Isabelle; Cheviron, Nathalie; Hedde, Mickaël

    2014-01-01

    Generic biomarkers are needed to assess environmental risks in metal polluted soils. We assessed the strength of the relationship between earthworm energy reserves and metal availability under conditions of cocktail of metals at low doses and large range of soil parameters. Aporrectodea caliginosa was exposed in laboratory to a panel of soils differing in Cd, Pb and Zn total and available (CaCl 2 and EDTA-extractable) concentrations, and in soil texture, pH, CEC and organic-C. Glycogen, protein and lipid contents were recorded in exposed worms. Glycogen contents were not linked to the explaining variables considered. Variable selection identified CaCl 2 extractable metals concentrations and soil texture as the main factors affecting protein and lipid contents. The results showed opposite effects of Pb and Zn, high inter-individual variability of biomarkers and weak relationships with easily extractable metals. Our results support the lack of genericity of energy reserves in earthworms exposed to field-contaminated soils. - Highlights: • Energy reserves were quantified in earthworms exposed to a wide panel of field soils. • Protein and lipid contents were related to CaCl 2 extractable metals. • Soil texture affected protein and lipid contents. • Energy reserves were highly variable inter-individually. - Earthworm energy reserves response to low doses of available metals is not generic

  17. Self energies of the electron and photon in the unified space field theory

    International Nuclear Information System (INIS)

    Duong Van Phi, Nguyen Mong Giao.

    1981-01-01

    Self energies of the electron and photon are calculated in the second approximation of perturbation theory. The formalism of the field theory of interaction in the unified 8-dimensional space is used. The calculations are free of divergence the unitary condition is fulfilled. It is shown that the ''naked'' and physical masses of a free electron are identical. A similar result is obtained for a free photon. Some other effects are discussed [ru

  18. N{sub 2}O Emission from energy crop fields

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, B.J. [The Royal Veterinary and Agricultural Univ., Dept. of Agricultural Sciences, Section of Soil, Water and Plant Nutrition (Denmark); Nyholm Joergensen, R. [Research Centre Foulum, The Danish Inst. of Plant and Soil Science, Dept. of Soil Science (Denmark)

    1996-03-01

    The interest in N{sub 2}O emissions from soils with energy crops is a results of its properties as a greenhouse gas, since the global warming potential of N{sub 2}O per unit mass is about 320 times greater than CO{sub 2}. The contribution of N{sub 2}O from the soil to the atmosphere may increase due to agricultural management. Consequently, large N{sub 2}O emissions can lower the reduction of the greenhouse effect achieved by the substitution of fossil fuels by energy crops. For this reason it is crucial to find the crops for combustion with the lowest potential for emission of N{sub 2}O from the soil per produced energy unit. The aims of this study were to assess the annual N{sub 2}O flux from a Miscanthus 'Giganteus' (M. 'Giganteus') and winter rye (Secale cereale) field, and to investigate the factors affecting the N{sub 2}O emission. To obtain these aims a method was developed for measurements in tall crops. The thesis contains a literature review on the N{sub 2}O emission from the soils, a section with development of the technique for N{sub 2}O flux measurements, and an experimental section. Finally, the thesis contains a section where the results are discussed in relation to the use of energy crops. In all the filed studies, the N{sub 2}O emission was measured by using a new developed closed-chamber technique. The main advantages of the chamber method were the ability to contain growing plants up to a height of 3 m, and the relatively large area (2X2m) covered by each other. Soils with annual and perennial crops can be expected to emit less then 3 kg N{sub 2}O ha{sup -1} yr{sup -1}. This amount corresponds to 960 kg CO{sub 2} ha{sup -1} yr{sup -1} compared to a total CO{sub 2} reduction of 10 to 19 tons CO{sub 2} ha{sup -1} yr{sup -1} using the energy crops as substitution for fossil fuels. An efficient way to reduce the N{sub 2}O emission is to exclude use of fertiliser but this also reduces the dry matter yield and consequently also the

  19. N{sub 2}O Emission from energy crop fields

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, B.J. [The Royal Veterinary and Agricultural Univ., Dept. of Agricultural Sciences, Section of Soil, Water and Plant Nutrition (Denmark); Nyholm Joergensen, R. [Research Centre Foulum, The Danish Inst. of Plant and Soil Science, Dept. of Soil Science (Denmark)

    1996-03-01

    The interest in N{sub 2}O emissions from soils with energy crops is a results of its properties as a greenhouse gas, since the global warming potential of N{sub 2}O per unit mass is about 320 times greater than CO{sub 2}. The contribution of N{sub 2}O from the soil to the atmosphere may increase due to agricultural management. Consequently, large N{sub 2}O emissions can lower the reduction of the greenhouse effect achieved by the substitution of fossil fuels by energy crops. For this reason it is crucial to find the crops for combustion with the lowest potential for emission of N{sub 2}O from the soil per produced energy unit. The aims of this study were to assess the annual N{sub 2}O flux from a Miscanthus `Giganteus` (M. `Giganteus`) and winter rye (Secale cereale) field, and to investigate the factors affecting the N{sub 2}O emission. To obtain these aims a method was developed for measurements in tall crops. The thesis contains a literature review on the N{sub 2}O emission from the soils, a section with development of the technique for N{sub 2}O flux measurements, and an experimental section. Finally, the thesis contains a section where the results are discussed in relation to the use of energy crops. In all the filed studies, the N{sub 2}O emission was measured by using a new developed closed-chamber technique. The main advantages of the chamber method were the ability to contain growing plants up to a height of 3 m, and the relatively large area (2X2m) covered by each other. Soils with annual and perennial crops can be expected to emit less then 3 kg N{sub 2}O ha{sup -1} yr{sup -1}. This amount corresponds to 960 kg CO{sub 2} ha{sup -1} yr{sup -1} compared to a total CO{sub 2} reduction of 10 to 19 tons CO{sub 2} ha{sup -1} yr{sup -1} using the energy crops as substituion for fossil fuels. An efficient way to reduce the N{sub 2}O emission is to exclude use of fertiliser but this also reduces the dry matter yield and consequently also the CO{sub 2} reduction

  20. Far-field RF energy transfer and harvesting

    NARCIS (Netherlands)

    Visser, H.J.; Vullers, R.; Briand, D.; Yeatman, E.; Roundy, S.

    2015-01-01

    This chapter deals with radio frequency (RF) energy transfer over a distance. After explaining the differences between nonradiative and radiative RF energy transfer, the chapter gives definitions for transfer and harvesting. Nonradiative RF energy transfer is mostly employed in inductive systems,

  1. Electric and hybrid cars - interaction with the power system; El- og hybridbiler - samspil med elsystemet

    Energy Technology Data Exchange (ETDEWEB)

    2010-06-15

    25% of Denmark's CO{sub 2}emissions come from transport. At the same time road transport accounts for 50% of Denmark's consumption of oil. The transport sector is therefore one of the major challenges when it comes to reducing CO{sub 2}emissions. The Danish Energy Agency's report on electric vehicles' interaction with the power system concludes that electric cars can help reduce climate impacts and dependence on fossil fuels, but success would depend on whether we have an intelligent electricity grid - a smart grid. A smart grid will ensure that car batteries are charged at the times of day when demand for electricity is low but electricity is still produced from e.g. windmills. Eventually, a smart grid will also enable the power system to draw electricity from car batteries in the periods of the day when electricity demand is particularly high. A prerequisite for reaping the benefits is that electric vehicles can interplay with the power system - a requirement that will increase with more electric cars introduced. (ln)

  2. Comparative study of energy of particles ejected from coulomb explosion of rare gas and metallic clusters irradiated by intense femtosecond laser field

    Science.gov (United States)

    Boucerredj, N.; Beggas, K.

    2016-10-01

    We present our study of high intensity femtosecond laser field interaction with large cluster of Kr and Na (contained 2.103 to 2.107 atoms). When laser intensity is above a critical value, it blows off all of electrons from the cluster and forms a non neutral ion cloud. The irradiation of these clusters by the intense laser field leads to highly excitation energy which can be the source of energetic electrons, electronic emission, highly charge, energetic ions and fragmentation process. During the Coulomb explosion of the resulting highly ionized, high temperature nanoplasma, ions acquire again their energy. It is shown that ultra fast ions are produced. The goal of our study is to investigate in detail a comparative study of the expansion and explosion then the ion energy of metallic and rare gas clusters irradiated by an intense femtosecond laser field. We have found that ions have a kinetic energy up to 105 eV and the Coulomb pressure is little than the hydrodynamic pressure. The Coulomb explosion of a cluster may provide a new high energy ion source.

  3. FY 1997 report on the field survey on country situations including efficient energy consumption. Vietnam; 1997 nendo chosa hokokusho (energy shohi koritsuka nado chiiki josei genchi chosa). Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Field survey was made on the current state of and issues on energy in Vietnam. In Vietnam, firewood is in wide use as non-commercial energy, and sums to a half of total energy consumption. Other energies such as hydroelectric power, petroleum, natural gas and coal are self-sustainable. Commercial energy consumption in 1995 is estimated at 10,070,000t in oil equivalent, which is broken down into 23% for coal, 42% in oil, 5% for natural gas and 30% for electricity. Abundant water resources will form the mainstay of future electric power supply. Commercial production of oil started in 1986 becoming an oil exporting country. Several promising natural gas fields were discovered as the result of the exploration by foreign capital. Coal deposits are estimated to be nearly 3.5 billion tons, and most of them are anthracite. Electric power demand is growing at a higher rate than the economic growth of Vietnam. The growth rate of electric power demand is set to be 1.3 times that of GDP. Since construction funds for new plants cannot be satisfied with the national budget and domestic investment alone, the country is expecting foreign capitals. 21 figs., 36 tabs.

  4. A new Recoil Proton Telescope for energy and fluence measurement of fast neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Lebreton, Lena; Bachaalany, Mario [IRSN / LMDN (Institut de Radioprotection et de Surete nucleaire / Laboratoire de Metrologie et de dosimetrie des neutrons), Cadarache Bat.159, 13115 Saint Paul-lez-Durance, (France); Husson, Daniel; Higueret, Stephane [IPHC / RaMsEs (Institut Pluridisciplinaire Hubert Curien / Radioprotection et Mesures Environnementales), 23 rue du loess - BP28, 67037 Strasbourg cedex 2, (France)

    2015-07-01

    The spectrometer ATHENA (Accurate Telescope for High Energy Neutron metrology Applications), is being developed at the IRSN / LMDN (Institut de Radioprotection et de Surete nucleaire / Laboratoire de Metrologie et de dosimetrie des neutrons) and aims at characterizing energy and fluence of fast neutron fields. The detector is a Recoil Proton Telescope and measures neutron fields in the range of 5 to 20 MeV. This telescope is intended to become a primary standard for both energy and fluence measurements. The neutron detection is achieved by a polyethylene radiator for n-p conversion, three 50{sub m} thick silicon sensors that use CMOS technology for the proton tracking and a 3 mm thick silicon diode to measure the residual proton energy. This first prototype used CMOS sensors called MIMOSTAR, initially developed for heavy ion physics. The use of CMOS sensors and silicon diode increases the intrinsic efficiency of the detector by a factor of ten compared with conventional designs. The first prototype has already been done and was a successful study giving the results it offered in terms of energy and fluence measurements. For mono energetic beams going from 5 to 19 MeV, the telescope offered an energy resolution between 5 and 11% and fluence difference going from 5 to 7% compared to other home standards. A second and final prototype of the detector is being designed. It will hold upgraded CMOS sensors called FastPixN. These CMOS sensors are supposed to run 400 times faster than the older version and therefore give the telescope the ability to support neutron flux in the order of 107 to 108cm{sup 2}:s{sup 1}. The first prototypes results showed that a 50 m pixel size is enough for a precise scattering angle reconstruction. Simulations using MCNPX and GEANT4 are already in place for further improvements. A DeltaE diode will replace the third CMOS sensor and will be installed right before the silicon diode for a better recoil proton selection. The final prototype with

  5. Unusual high-energy phenomenology of Lorentz-invariant noncommutative field theories

    International Nuclear Information System (INIS)

    Carone, Christopher D.; Kwee, Herry J.

    2006-01-01

    It has been suggested that one may construct a Lorentz-invariant noncommutative field theory by extending the coordinate algebra to additional, fictitious coordinates that transform nontrivially under the Lorentz group. Integration over these coordinates in the action produces a four-dimensional effective theory with Lorentz invariance intact. Previous applications of this approach, in particular, to a specific construction of noncommutative QED, have been studied only in a low-momentum approximation. Here we discuss Lorentz-invariant field theories in which the relevant physics can be studied without requiring an expansion in the inverse scale of noncommutativity. Qualitatively, we find that tree-level scattering cross sections are dramatically suppressed as the center-of-mass energy exceeds the scale of noncommutativity, that cross sections that are isotropic in the commutative limit can develop a pronounced angular dependence, and that nonrelativistic potentials (for example, the Coloumb potential) become nonsingular at the origin. We consider a number of processes in noncommutative QED that may be studied at a future linear collider. We also give an example of scattering via a four-fermion operator in which the noncommutative modifications of the interaction can unitarize the tree-level amplitude, without requiring any other new physics in the ultraviolet

  6. Observational constraints on scalar field models of dark energy with barotropic equation of state

    International Nuclear Information System (INIS)

    Sergijenko, Olga; Novosyadlyj, Bohdan; Durrer, Ruth

    2011-01-01

    We constrain the parameters of dynamical dark energy in the form of a classical or tachyonic scalar field with barotropic equation of state jointly with other cosmological parameters using the following datasets: the CMB power spectra from WMAP7, the baryon acoustic oscillations in the space distribution of galaxies from SDSS DR7, the power spectrum of luminous red galaxies from SDSS DR7 and the light curves of SN Ia from 2 different compilations: Union2 (SALT2 light curve fitting) and SDSS (SALT2 and MLCS2k2 light curve fittings). It has been found that the initial value of dark energy equation of state parameter is constrained very weakly by most of the data while the other cosmological parameters are well constrained: their likelihoods and posteriors are similar, their forms are close to Gaussian (or half-Gaussian) and the confidence ranges are narrow. The most reliable determinations of the best-fit value and 1σ confidence range for the initial value of the dark energy equation of state parameter are obtained from the combined datasets including SN Ia data from the full SDSS compilation with MLCS2k2 light curve fitting. In all such cases the best-fit value of this parameter is lower than the value of corresponding parameter for current epoch. Such dark energy loses its repulsive properties and in future the expansion of the Universe changes into contraction. We also perform a forecast for the Planck mock data and show that they narrow significantly the confidence ranges of cosmological parameters values, moreover, their combination with SN SDSS compilation with MLCS2k2 light curve fitting may exclude the fields with initial equation of state parameter > −0.1 at 2σ confidence level

  7. Exploration of the potential employment opportunities in the field of renewable energies in ''Wadi AL-ajal''

    International Nuclear Information System (INIS)

    Azzain, Gassem

    2015-01-01

    This inductive research is located within the theme of the management and development of renewable energy systems. In brief, It introduces the potential and ability of renewable energies available in “Wadi AL-ajal”, which is located south-west of Libya, in providing many job opportunities; in addition to power generation. Several proposed investment models in solar, wind and biomass energies in this paper show -via statistical approach- how to provide a variety of job opportunities according to investment activities proposed in the three mentioned fields of renewable energies. In conclusion, the paper confirms the availability of the earlier mentioned renewable energies in varying amounts and varying degrees, they are all able to create jobs and employment of advanced technology, which are necessary for any national program for sustainable development, with the support of economic stimuli that affect investment, such as; the market activation, human resources, and finance.(author)

  8. Energy-momentum tensor in theories with scalar fields and two coupling constants. I. Non-Abelian case

    International Nuclear Information System (INIS)

    Joglekar, S.D.; Misra, A.

    1989-01-01

    In this paper, we generalize our earlier discussion of renormalization of the energy-momentum tensor in scalar QED to that in non-Abelian gauge theories involving scalar fields. We show the need for adding an improvement term to the conventional energy-momentum tensor. We consider two possible forms for the improvement term: (i) one in which the improvement coefficient is a finite function of bare parameters of the theory (so that the energy-momentum tensor can be derived from an action that is a finite function of bare quantities); (ii) one in which the improvement coefficient is a finite quantity, i.e., a finite function of renormalized parameters. We establish a negative result; viz., neither form leads to a finite energy-momentum tensor to O(e 2 λ/sup n/)

  9. Dark Energy and Structure Formation

    International Nuclear Information System (INIS)

    Singh, Anupam

    2010-01-01

    We study the gravitational dynamics of dark energy configurations. We report on the time evolution of the dark energy field configurations as well as the time evolution of the energy density to demonstrate the gravitational collapse of dark energy field configurations. We live in a Universe which is dominated by Dark Energy. According to current estimates about 75% of the Energy Density is in the form of Dark Energy. Thus when we consider gravitational dynamics and Structure Formation we expect Dark Energy to play an important role. The most promising candidate for dark energy is the energy density of fields in curved space-time. It therefore become a pressing need to understand the gravitational dynamics of dark energy field configurations. We develop and describe the formalism to study the gravitational collapse of fields given any general potential for the fields. We apply this formalism to models of dark energy motivated by particle physics considerations. We solve the resulting evolution equations which determine the time evolution of field configurations as well as the dynamics of space-time. Our results show that gravitational collapse of dark energy field configurations occurs and must be considered in any complete picture of our universe.

  10. Non-minimal derivative coupling scalar field and bulk viscous dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Mostaghel, Behrang [Shahid Beheshti University, Department of Physics, Tehran (Iran, Islamic Republic of); Moshafi, Hossein [Institute for Advanced Studies in Basic Sciences, Department of Physics, Zanjan (Iran, Islamic Republic of); Movahed, S.M.S. [Shahid Beheshti University, Department of Physics, Tehran (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of)

    2017-08-15

    Inspired by thermodynamical dissipative phenomena, we consider bulk viscosity for dark fluid in a spatially flat two-component Universe. Our viscous dark energy model represents phantom-crossing which avoids big-rip singularity. We propose a non-minimal derivative coupling scalar field with zero potential leading to accelerated expansion of the Universe in the framework of bulk viscous dark energy model. In this approach, the coupling constant, κ, is related to viscosity coefficient, γ, and the present dark energy density, Ω{sub DE}{sup 0}. This coupling is bounded as κ element of [-1/9H{sub 0}{sup 2}(1 - Ω{sub DE}{sup 0}), 0]. We implement recent observational data sets including a joint light-curve analysis (JLA) for SNIa, gamma ray bursts (GRBs) for most luminous astrophysical objects at high redshifts, baryon acoustic oscillations (BAO) from different surveys, Hubble parameter from HST project, Planck CMB power spectrum and lensing to constrain model free parameters. The joint analysis of JLA + GRBs + BAO + HST shows that Ω{sub DE}{sup 0} = 0.696 ± 0.010, γ = 0.1404 ± 0.0014 and H{sub 0} = 68.1 ± 1.3. Planck TT observation provides γ = 0.32{sup +0.31}{sub -0.26} in the 68% confidence limit for the viscosity coefficient. The cosmographic distance ratio indicates that current observed data prefer to increase bulk viscosity. The competition between phantom and quintessence behavior of the viscous dark energy model can accommodate cosmological old objects reported as a sign of age crisis in the ΛCDM model. Finally, tension in the Hubble parameter is alleviated in this model. (orig.)

  11. Energy levels of a scalar particle in a static gravitational field close to the black hole limit

    Science.gov (United States)

    Gossel, G. H.; Berengut, J. C.; Flambaum, V. V.

    2011-10-01

    The bound-state energy levels of a scalar particle in the gravitational field of finite-sized objects with interiors described by the Florides and Schwarzschild metrics are found. For these metrics, bound states with zero energy (where the binding energy is equal to the rest mass of the scalar particle) only exist when a singularity occurs in the metric. Therefore, in contrast to the Coulomb case, no pairs are produced in the non-singular static metric. For the Florides metric the singularity occurs in the black hole limit, while for the Schwarzschild interior metric it corresponds to infinite pressure at the center. Moreover, the energy spectrum is shown to become quasi-continuous as the metric becomes singular.

  12. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    Energy Technology Data Exchange (ETDEWEB)

    Teng, J.; Gu, Y.Q., E-mail: tengjian@mail.ustc.edu.cn; Zhu, B.; Hong, W.; Zhao, Z.Q.; Zhou, W.M.; Cao, L.F.

    2013-11-21

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

  13. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    Science.gov (United States)

    Teng, J.; Gu, Y. Q.; Zhu, B.; Hong, W.; Zhao, Z. Q.; Zhou, W. M.; Cao, L. F.

    2013-11-01

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

  14. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    International Nuclear Information System (INIS)

    Teng, J.; Gu, Y.Q.; Zhu, B.; Hong, W.; Zhao, Z.Q.; Zhou, W.M.; Cao, L.F.

    2013-01-01

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator

  15. An electric field in a gravitational field

    International Nuclear Information System (INIS)

    Harpaz, Amos

    2005-01-01

    The behaviour of an electric field in a gravitational field is analysed. It is found that due to the mass (energy) of the electric field, it is subjected to gravity and it falls in the gravitational field. This fall curves the electric field, a stress force (a reaction force) is created, and the interaction of this reaction force with the static charge gives rise to the creation of radiation

  16. Field-orientation dependence of low-energy quasiparticle excitations in the heavy-electron superconductor UBe(13).

    Science.gov (United States)

    Shimizu, Yusei; Kittaka, Shunichiro; Sakakibara, Toshiro; Haga, Yoshinori; Yamamoto, Etsuji; Amitsuka, Hiroshi; Tsutsumi, Yasumasa; Machida, Kazushige

    2015-04-10

    Low-energy quasiparticle excitations in the superconducting (SC) state of UBe_{13} were studied by means of specific-heat (C) measurements in a rotating field. Quite unexpectedly, the magnetic-field dependence of C(H) is linear in H with no angular dependence at low fields in the SC state, implying that the gap is fully open over the Fermi surfaces, in stark contrast to previous expectations. In addition, a characteristic cubic anisotropy of C(H) was observed above 2 T with a maximum (minimum) for H∥[001] ([111]) within the (11[over ¯]0) plane, in the normal as well as in the SC states. This oscillation possibly originates from the anisotropic response of the heavy quasiparticle bands, and might be a key to understand the unusual properties of UBe_{13}.

  17. Electric fields and electron energies in sprites and temporal evolutions of lightning charge moment

    International Nuclear Information System (INIS)

    Adachi, T; Hiraki, Y; Yamamoto, K; Takahashi, Y; Fukunishi, H; Hsu, R-R; Su, H-T; Chen, A B; Mende, S B; Frey, H U; Lee, L C

    2008-01-01

    The fundamental electrodynamical coupling processes between lightning and sprites are investigated. By combining the observed spectral data with the Monte Carlo swarm experiments, reduced electric fields and electron energies in sprite streamers and halos are estimated. The obtained fields inside sprite halos (70-97 Td with an analysis error of ±5 Td) are lower than the conventional breakdown field, E k ∼ 128 Td, indicating a significant reduction of electrons associated with halos while those in sprite streamers (98-380 Td with an error of ±50 Td) are higher than E k , suggesting that a significant ionization process drives their formation and development. A combined analysis of photometric and electromagnetic data makes it possible to estimate temporal evolutions of lightning charge moment. It is found that lightning discharges with a short time scale (∼1 ms) and a moderate amount of charge moment (∼400 C km) produce discernible halos. On the other hand, lightning discharges with a large amount of charge moment (∼1300 C km) produce streamers regardless of their time scale. The results obtained are comprehensively interpreted with both the conventional breakdown field necessary for the formation of streamers and the electric field necessary for the production of optical emissions of halo which is sensitive to the time scale of the thundercloud field due to the significant reduction of electrons.

  18. Computer usage and national energy consumption: Results from a field-metering study

    Energy Technology Data Exchange (ETDEWEB)

    Desroches, Louis-Benoit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Fuchs, Heidi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Greenblatt, Jeffery [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Pratt, Stacy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Willem, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Claybaugh, Erin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Beraki, Bereket [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Nagaraju, Mythri [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Price, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Young, Scott [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division

    2014-12-01

    The electricity consumption of miscellaneous electronic loads (MELs) in the home has grown in recent years, and is expected to continue rising. Consumer electronics, in particular, are characterized by swift technological innovation, with varying impacts on energy use. Desktop and laptop computers make up a significant share of MELs electricity consumption, but their national energy use is difficult to estimate, given uncertainties around shifting user behavior. This report analyzes usage data from 64 computers (45 desktop, 11 laptop, and 8 unknown) collected in 2012 as part of a larger field monitoring effort of 880 households in the San Francisco Bay Area, and compares our results to recent values from the literature. We find that desktop computers are used for an average of 7.3 hours per day (median = 4.2 h/d), while laptops are used for a mean 4.8 hours per day (median = 2.1 h/d). The results for laptops are likely underestimated since they can be charged in other, unmetered outlets. Average unit annual energy consumption (AEC) for desktops is estimated to be 194 kWh/yr (median = 125 kWh/yr), and for laptops 75 kWh/yr (median = 31 kWh/yr). We estimate national annual energy consumption for desktop computers to be 20 TWh. National annual energy use for laptops is estimated to be 11 TWh, markedly higher than previous estimates, likely reflective of laptops drawing more power in On mode in addition to greater market penetration. This result for laptops, however, carries relatively higher uncertainty compared to desktops. Different study methodologies and definitions, changing usage patterns, and uncertainty about how consumers use computers must be considered when interpreting our results with respect to existing analyses. Finally, as energy consumption in On mode is predominant, we outline several energy savings opportunities: improved power management (defaulting to low-power modes after periods of inactivity as well as power scaling), matching the rated power

  19. Analytic solutions in the dyon black hole with a cosmic string: Scalar fields, Hawking radiation and energy flux

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, H.S., E-mail: horacio.santana.vieira@hotmail.com [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil); Centro de Ciências, Tecnologia e Saúde, Universidade Estadual da Paraíba, CEP 58233-000, Araruna, PB (Brazil); Bezerra, V.B., E-mail: valdir@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil); Silva, G.V., E-mail: gislainevs@hotmail.com [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil)

    2015-11-15

    Charged massive scalar fields are considered in the gravitational and electromagnetic field produced by a dyonic black hole with a cosmic string along its axis of symmetry. Exact solutions of both angular and radial parts of the covariant Klein–Gordon equation in this background are obtained, and are given in terms of the confluent Heun functions. The role of the presence of the cosmic string in these solutions is showed up. From the radial solution, we obtain the exact wave solutions near the exterior horizon of the black hole, and discuss the Hawking radiation spectrum and the energy flux. -- Highlights: •A cosmic string is introduced along the axis of symmetry of the dyonic black hole. •The covariant Klein–Gordon equation for a charged massive scalar field in this background is analyzed. •Both angular and radial parts are transformed to a confluent Heun equation. •The resulting Hawking radiation spectrum and the energy flux are obtained.

  20. 1984 Ordinance on definitions and licences in the atomic energy field. Amendment of 2 March 1987

    International Nuclear Information System (INIS)

    1987-01-01

    Following the partial revision of the Federal Act of 23rd December 1959 on atomic energy concerning import and export of nuclear items and technology the Ordinance of 18th January 1984 on definitions and licensing in the atomic energy field was also amended. The mandatory licensing system now covers the export of technologies (unpublished technical data concerning installations for the enrichment and reprocessing of nuclear fuels as well as for heavy water production). This amendment became effective on 1st April 1987. (NEA) [fr