WorldWideScience

Sample records for transportation systems magnetic

  1. Magnetic type transportation system

    International Nuclear Information System (INIS)

    Kobama, Masao.

    1981-01-01

    Purpose: To enable automatic transportation of nuclear substances with optional setting for the transportation distance, even for a long distance, facilitating the automation of the transportation and decreasing the space for the installation of a direction converging section of the transporting path. Constitution: A transporting vehicle having a pair of permanent magnets or ferromagnetic bodies mounted with a predetermined gap to each other along the transporting direction is provided in the transporting path including a bent direction change section for transporting specimens such as nuclear materials, and a plurality of driving vehicles having permanent magnets or ferromagnetic bodies for magnetically attracting the transporting vehicle from outside of the transporting path are arranged to the outside of the transporting path. At least one of the driving vehicles is made to run along the transporting direction of the transporting path by a driving mechanism incorporating running section such as an endless chain to drive the transportation vehicle, and the transporting vehicle is successively driven by each of the driving mechanisms. (Kawakami, Y.)

  2. Magnetic levitation -The future transport system

    International Nuclear Information System (INIS)

    Rairan, Danilo

    2000-01-01

    The paper made a recount of the main advantages and disadvantages of the traditional systems of transport with base in electric power and it shows as the systems that use the magnetic levitation they are the future of the transport. Additionally it presents the physical principle of operation of the two main systems developed at the present time

  3. Electronic transport and magnetization dynamics in magnetic systems

    International Nuclear Information System (INIS)

    Borlenghi, Simone

    2011-01-01

    The aim of this thesis is to understand the mutual influence between electronic transport and magnetization dynamics in magnetic hybrid metallic nano-structures. At first, we have developed a theoretical model, based on random matrix theory, to describe at microscopic level spin dependent transport in a heterogeneous nano-structure. This model, called Continuous Random Matrix Theory (CRMT), has been implemented in a simulation code that allows one to compute local (spin torque, spin accumulation and spin current) and macroscopic (resistance) transport properties of spin valves. To validate this model, we have compared it with a quantum theory of transport based on the non equilibrium Green's functions formalism. Coupling the two models has allowed to perform a multi-scale description of metallic hybrid nano-structures, where ohmic parts are described using CRMT, while purely quantum parts are described using Green's functions. Then, we have coupled CRMT to a micro-magnetic simulation code, in order to describe the complex dynamics of the magnetization induced by spin transfer effect. The originality of this approach consists in modelling a spectroscopic experiment based on a mechanical detection of the ferromagnetic resonance, and performed on a spin torque nano-oscillator. This work has allowed us to obtain the dynamical phase diagram of the magnetization, and to detect the selection rules for spin waves induced by spin torque, as well as the competition between the Eigen-modes of the system when a dc current flows through the multilayer, in partial agreement with experimental data. (author)

  4. Mixed-μ magnetic levitation for advanced ground transport system

    International Nuclear Information System (INIS)

    Russell, F.M.

    1977-12-01

    The possibility of applying the mixed-μ principle for magnetic levitation to ground transport systems is examined. The system is developed specifically for suspension and useful lift to passive weight ratios exceeding 8:1 have been calculated. Application to a hybrid system where conventional wheel drive is used in conjunction with magnetic levitation is explained for urban transport. (author)

  5. Modular transportable superconducting magnetic energy systems

    Science.gov (United States)

    Lieurance, Dennis; Kimball, Foster; Rix, Craig

    1995-04-01

    Design and cost studies were performed for the magnet components of mid-size (1-5 MWh), cold supported SMES systems using alternative configurations. The configurations studied included solenoid magnets, which required onsite assembly of the magnet system, and toroid and racetrack configurations which consisted of factory assembled modules. For each configuration, design concepts and cost information were developed for the major features of the magnet system including the conductor, electrical insulation, and structure. These studies showed that for mid-size systems, the costs of solenoid and toroid magnet configurations are comparable and that the specific configuration to be used for a given application should be based upon customer requirements such as limiting stray fields or minimizing risks in development or construction.

  6. Modular transportable superconducting magnetic Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lieurance, D.; Kimball, F.; Rix, C. [Martin Marietta Space Magnetics, San Diego, CA (United States)

    1994-12-31

    Design and cost studies were performed for the magnet components of mid-size (1-5 MWh), cold supported SMES systems using alternative configurations. The configurations studied included solenoid magnets, which required onsite assembly of the magnet system, and toroid and racetrack configurations which consisted of factory assembled modules. For each configuration, design concepts and cost information were developed for the major features of the magnet system including the conductor, electrical insulation, and structure. These studies showed that for mid-size systems, the costs of solenoid and toroid magnet configurations are comparable and that the specific configuration to be used for a given application should be based upon customer requirements such as limiting stray fields or minimizing risks in development or construction.

  7. New magnet transport system for the LHC beam transfer lines

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system (pictured here in one of the tunnels) is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The lead vehicle is powered by an electric rail set into the roof of the tunnel. The system is backed up by electrical batteries that enable it to operate in the absence of an outside power source or in the event of power failure. Last but not least, for the long-distance transport of magnets, it can be optically guided by a line traced on the tunnel floor. The convoy moves through the particularly narr...

  8. Expansion joint for guideway for magnetic levitation transportation system

    Science.gov (United States)

    Rossing, T.D.

    1993-02-09

    An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The side walls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging side walls so that the cuts have a substantially dove-tail shape.

  9. Nonequilibrium spin transport through a diluted magnetic semiconductor quantum dot system with noncollinear magnetization

    International Nuclear Information System (INIS)

    Ma, Minjie; Jalil, Mansoor Bin Abdul; Tan, Seng Gee

    2013-01-01

    The spin-dependent transport through a diluted magnetic semiconductor quantum dot (QD) which is coupled via magnetic tunnel junctions to two ferromagnetic leads is studied theoretically. A noncollinear system is considered, where the QD is magnetized at an arbitrary angle with respect to the leads’ magnetization. The tunneling current is calculated in the coherent regime via the Keldysh nonequilibrium Green’s function (NEGF) formalism, incorporating the electron–electron interaction in the QD. We provide the first analytical solution for the Green’s function of the noncollinear DMS quantum dot system, solved via the equation of motion method under Hartree–Fock approximation. The transport characteristics (charge and spin currents, and tunnel magnetoresistance (TMR)) are evaluated for different voltage regimes. The interplay between spin-dependent tunneling and single-charge effects results in three distinct voltage regimes in the spin and charge current characteristics. The voltage range in which the QD is singly occupied corresponds to the maximum spin current and greatest sensitivity of the spin current to the QD magnetization orientation. The QD device also shows transport features suitable for sensor applications, i.e., a large charge current coupled with a high TMR ratio. - Highlights: ► The spin polarized transport through a diluted magnetic quantum dot is studied. ► The model is based on the Green’s function and the equation of motion method.► The charge and spin currents and tunnel magnetoresistance (TMR) are investigated. ► The system is suitable for current-induced spin-transfer torque application. ► A large tunneling current and a high TMR are possible for sensor application.

  10. Coupled particle–fluid transport and magnetic separation in microfluidic systems with passive magnetic functionality

    International Nuclear Information System (INIS)

    Khashan, Saud A; Furlani, Edward P

    2013-01-01

    A study is presented of coupled particle–fluid transport and field-directed particle capture in microfluidic systems with passive magnetic functionality. These systems consist of a microfluidic flow cell on a substrate that contains embedded magnetic elements. Two systems are considered that utilize soft- and hard-magnetic elements, respectively. In the former, an external field is applied to magnetize the elements, and in the latter, they are permanently magnetized. The field produced by the magnetized elements permeates into the flow cell giving rise to an attractive force on magnetic particles that flow through it. The systems are studied using a novel numerical/closed-form modelling approach that combines numerical transport analysis with closed-form field analysis. Particle–fluid transport is computed using computational fluid dynamics (CFD), while the magnetic force that governs particle capture is obtained in closed form. The CFD analysis takes into account dominant particle forces and two-way momentum transfer between the particles and the fluid. The two-way particle–fluid coupling capability is an important feature of the model that distinguishes it from more commonly used and simplified one-way coupling analysis. The model is used to quantify the impact of two-way particle–fluid coupling on both the capture efficiency and the flow pattern in the systems considered. Many effects such as particle-induced flow-enhanced capture efficiency and flow circulation are studied that cannot be predicted using one-way coupling analysis. In addition, dilute particle dispersions are shown to exhibit significant localized particle–fluid coupling near the capture regions, which contradicts the commonly held view that two-way coupling can be ignored when analysing high-gradient magnetic separation involving such particle systems. Overall, the model demonstrates that two-way coupling needs to be taken into account for rigorous predictions of capture efficiency

  11. SLC Arc transport system: AG-magnet measurement and performance

    International Nuclear Information System (INIS)

    Weng, W.T.; Anderson, M.; Byers, R.; Cobb, J.; Fischer, G.; Hamilton, V.

    1985-03-01

    This paper describes the design, construction, and operation of devices used to rapidly measure the mechanical and magnetic properties of some 950 Alternate gradient magnets used in the arc system of the Stanford Linear Collider. The problems of dealing with the measurement of the transverse dimensions to within minute (0.0001 in.) resolution of objects that are 8 ft long are discussed. Early results from the production runs of these magnets are presented. 7 refs., 6 figs

  12. ELECTROMAGNETIC SAFETY OF ELECTRIC TRANSPORT SYSTEMS: MAIN SOURCES AND PARAMETERS OF MAGNETIC FIELDS

    Directory of Open Access Journals (Sweden)

    N. G. Ptitsyna

    2013-03-01

    Full Text Available Magnetic fields produced by electric drive vehicles may break electromagnetic safety. For electromagnetic safety and electromagnetic compatibility knowledge about characteristics and sources of magnetic fields in the electric transport is necessary. The article deals with analysis of available data about magnetic fields in electric cars and comparison with results of our measurements carried out in the other types of electrified transport systems.

  13. Design approaches and parameters for magnetically levitated transport systems

    International Nuclear Information System (INIS)

    Danby, G.T.; Powell, J.R.

    1988-01-01

    Mechanically levitated transport system approaches are assessed with regard to thrust power needs, track cost, suspension stability, and safety. The null flux suspension appears as the favored approach, having the least thrust power requirements, highest stability, and lowest amount of track material. Various null flux configurations are described, together with operating parameters. The Linear Synchronous Motor (LSM) propulsion system is also described for propelling the suspended vehicles. Cryogenics and superconductivity aspects are discussed and the effect of high T/sub c/ superconductors evaluated

  14. Magneto-transport and optical control of magnetization in organic systems: From polymers to molecule-based magnets

    Science.gov (United States)

    Bozdag, Kadriye Deniz

    Organic systems can be synthesized to have various impressive properties such as room temperature magnetism, electrical conductivity as high as conventional metals and magnetic field dependent transport. In this dissertation, we report comprehensive experimental studies in two different classes of organic systems, V-Cr Prussian blue molecule-based magnets and polyaniline nanofiber networks. The first system, V-Cr Prussian blue magnets, belongs to a family of cyano-bridged bi-metallic compounds which display a broad range of interesting photoinduced magnetic properties. A notable example for optically controllable molecule-based magnets is Co-Fe Prussian blue magnet (Tc ˜ 12 K), which exhibits light-induced changes in between magnetic states together with glassy behavior. In this dissertation, the first reports of reversible photoinduced magnetic phenomena in V-Cr Prussian blue analogs and the analysis of its AC and DC magnetization behavior are presented. Optical excitation of V-Cr Prussian blue, one of the few room temperature molecule-based magnets, with UV light (lambda = 350 nm) suppresses magnetization, whereas subsequent excitation with green light (lambda = 514 nm) increases magnetization. The partial recovery effect of green light is observed only when the sample is previously UV-irradiated. Moreover the photoinduced state has a long lifetime at low temperatures (tau > 106 s at T = 10 K) indicating that V-Cr Prussian blue reaches a hidden metastable state upon illumination with UV light. The effects of optical excitation are maintained up to 200 K and completely erased when the sample is warmed above 250 K. Results of detailed magnetic studies and the likely microscopic mechanisms for the photo illumination effects on magnetic properties are discussed. The second organic system, polyaniline nanofiber networks, was synthesized via dilute polymerization and studied at low and high electric and magnetic fields for temperatures 2 K--250 K for their magneto-transport

  15. Fluid transportation mechanisms by a coupled system of elastic membranes and magnetic fluids

    International Nuclear Information System (INIS)

    Ido, Y.; Tanaka, K.; Sugiura, Y.

    2002-01-01

    The basic properties of the fluid transportation mechanism that is produced by the coupled waves propagating along a thin elastic membrane covering a magnetic fluid layer in a shallow and long rectangular vessel are investigated. It is shown that the progressive magnetic field induced by the rectangular pulses generates sinusoidal vibration of the displacement of elastic membrane and makes the system work more efficiently than the magnetic field induced by the pulse-width-modulation method

  16. Ab initio theory of perpendicular transport in layered magnetic systems

    Czech Academy of Sciences Publication Activity Database

    Kudrnovský, Josef; Drchal, Václav; Turek, Ilja; Dederichs, P. H.; Weinberger, P.; Bruno, P.

    2002-01-01

    Roč. 240, - (2002), s. 177-179 ISSN 0304-8853 R&D Projects: GA AV ČR IAA1010829; GA ČR GA202/00/0122; GA MŠk OC P5.30; GA MŠk OC P3.40; GA MŠk OC P3.70 Institutional research plan: CEZ:AV0Z1010914 Keywords : magnetoresistance -theory * ferromagnetic multilayers * disorder-alloys * electronic structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.046, year: 2002

  17. Application of Chebyshev Formalism to Identify Nonlinear Magnetic Field Components in Beam Transport Systems

    Energy Technology Data Exchange (ETDEWEB)

    Spata, Michael [Old Dominion Univ., Norfolk, VA (United States)

    2012-08-01

    An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a beam-based technique for characterizing the extent of the nonlinearity of the magnetic fields of a beam transport system. Horizontally and vertically oriented pairs of air-core kicker magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the beam orbit relative to the unperturbed reference orbit. Fourier decomposition of the position data at eight different points along the beamline was then used to measure the amplitude of these frequencies. For a purely linear transport system one expects to find solely the frequencies that were applied to the kickers with amplitudes that depend on the phase advance of the lattice. In the presence of nonlinear fields one expects to also find harmonics of the driving frequencies that depend on the order of the nonlinearity. Chebyshev polynomials and their unique properties allow one to directly quantify the magnitude of the nonlinearity with the minimum error. A calibration standard was developed using one of the sextupole magnets in a CEBAF beamline. The technique was then applied to a pair of Arc 1 dipoles and then to the magnets in the Transport Recombiner beamline to measure their multipole content as a function of transverse position within the magnets.

  18. A transportable magnetic resonance imaging system for in situ measurements of living trees: the Tree Hugger.

    Science.gov (United States)

    Jones, M; Aptaker, P S; Cox, J; Gardiner, B A; McDonald, P J

    2012-05-01

    This paper presents the design of the 'Tree Hugger', an open access, transportable, 1.1 MHz (1)H nuclear magnetic resonance imaging system for the in situ analysis of living trees in the forest. A unique construction employing NdFeB blocks embedded in a reinforced carbon fibre frame is used to achieve access up to 210 mm and to allow the magnet to be transported. The magnet weighs 55 kg. The feasibility of imaging living trees in situ using the 'Tree Hugger' is demonstrated. Correlations are drawn between NMR/MRI measurements and other indicators such as relative humidity, soil moisture and net solar radiation. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Turbulent transport in magnetized plasmas

    CERN Document Server

    Horton, Wendell

    2012-01-01

    This book explains how magnetized plasmas self-organize in states of electromagnetic turbulence that transports particles and energy out of the core plasma faster than anticipated by the fusion scientists designing magnetic confinement systems in the 20th century. It describes theory, experiments and simulations in a unified and up-to-date presentation of the issues of achieving nuclear fusion power.

  20. A 'V' shaped superconducting levitation module for lift and guidance of a magnetic transportation system

    International Nuclear Information System (INIS)

    D'Ovidio, G.; Crisi, F.; Lanzara, G.

    2008-01-01

    A novel, YBCO based, magnetic transportation system (MagTranS) is presented and described. The feasibility of this system has been successfully tested and confirmed in a laboratory using a scaled demonstrator system. The MagTranS levitation system uses a stable, self-balancing 'V' shaped superconducting module for both lift and guidance of vehicles. The work concept of the MagTranS levitation module is described and differences with regards to the maglev current systems are highlighted. The results of levitation tests performed using a measurement set-up are presented and discussed. Lastly, levitation module performance studies are also carried out using numerical finite element analysis

  1. Magnetic and transport behaviour in Pr3X(X=In,Sn,Ga,Ge,Ni,Co,Ru,Ir) systems

    International Nuclear Information System (INIS)

    Garde, C.S.; Ray, J.

    1998-01-01

    Magnetic and transport studies on Pr 3 X (X=In, Sn, Ga, Ge, Ni, Co, Ru, Ir) systems gave evidence for complex magnetic behaviour. All the systems, except X=Sn, exhibit ferromagnetic ordering. The X=Sn system exhibits antiferromagnetic ordering. For X=Ga and Sn, metamagnetic behaviour has been observed. Crystal field effects are found to play an important role in influencing magnetic behaviour. The strength of the crystal field term has also been estimated. (orig.)

  2. Mesoscopic spin-flip transport through a hybrid system with a single molecular dot system applied with ac magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Chen Qiao, E-mail: cqhy1127@yahoo.com.c [Department of Maths and Physics, Hunan Institute of Engineering, Xiangtan 411104 (China); Liu Jin [Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100190 (China); Wang Zhiyong [School of Optoelectronic Information, Chongqing University of Technology, Chongqing 400054 (China)

    2011-01-17

    We have investigated the current for the system of vibrating quantum dot irradiated with a rotating magnetic field and an oscillating magnetic field by nonequilibrium Green's function. The rotating magnetic field rotates with the angular frequency {omega}{sub r} around the z-axis with the tilt angle {theta}, and the time-oscillating magnetic field is located in the z-axis with the angular frequency {omega}. Different behaviors have been shown in the presence of electron-phonon interaction (EPI) which plays a significant role in the transport. The current displays asymmetric behavior as the source-drain bias eV=0, novel side peaks or shoulders can be found due to the phonon absorption and emission procedure, and the negative differential resistance becomes stronger as the parameter g increases. Furthermore, the strong EPI also destroys the quasiperiodic oscillations of current in the region {mu}{sub 0}B{sub 1}>2.5{Delta}. The electron transport properties are also significantly influenced by the linewidth function {Gamma}.

  3. A study on stable levitation of permanent magnet transportation system with coreless linear synchronous motor

    Energy Technology Data Exchange (ETDEWEB)

    Hiwaki, H [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Watada, M [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Torii, S [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Ebihara, D [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan)

    1996-12-31

    In the permanent magnet levitation system, it is impossible to stabilize the motion of the vehicle in both levitation and guidance directions only by permanent magnet. Therefore, the authors proposed the combined system of permanent magnet for levitation and coreless linear synchronous motor (coreless LSM). To design the coreless coils for LSM, the method to calculate the spring coefficient between coreless coil and permanent magnet for LSM is shown. By using this method, the spring coefficients of the three coil arrangements are compared and coreless coil is designed. Furthermore, the authors showed the possibility of stabilizing the motion of the levitation system with coreless LSM. (orig.)

  4. Safety of High Speed Magnetic Levitation Transportation Systems: Preliminary Safety Review of the Transrapid Maglev System

    Science.gov (United States)

    1990-11-01

    The safety of various magnetically levitated trains under development for possible : implementation in the United States is of direct concern to the Federal Railroad : Administration. This report, one in a series of planned reports on maglev safety, ...

  5. High speed magnetically levitated transport systems: Technical and economic aspects. Sistemi di trasporto ad alta velocita' a levitazione magnetica: Considerazioni tecniche ed economiche

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, G; Morini, A [Padua Univ. (Italy)

    1992-11-01

    In assessing the current state of technology relative to high speed (400 to 500 km/h) magnetically levitated (MAGLEV) transportation systems, this paper compares the technical aspects of the two main types of suspension systems now being developed specifically for these transportation systems, i.e., attractive electromagnetic using conventional magnets, and repulsive electrodynamic using superconducting magnets. Commercialization prospects for these systems are reviewed by analyzing areas where high speed levitated trains could compete against conventional rail and air transportation systems. The technology review includes progress reports on research and developments activities taking place in Germany and Japan, as well as, descriptions of some recent applications of this technology.

  6. Transport system

    NARCIS (Netherlands)

    Drenth, K.F.

    1999-01-01

    The transport system comprises at least one road surface (2) and at least one vehicle (4) on wheels (6). The road surface (2) has a substantially bowl-shaped cross section and the vehicle (4) is designed so that the wheels (6) run directly on the road surface (2) while the road surface (2) acts as a

  7. Magnetic permeability of stainless steel for use in accelerator beam transport systems

    International Nuclear Information System (INIS)

    Wilson, N.G.; Bunch, P.

    1991-01-01

    High-vacuum beam transport tubes are being designed for use in an accelerator under development at Los Alamos. In areas such as weld-heat-affected zones, the tubes will require localized magnetic permeability of less than 1.02. Seven austenitic stainless steel candidates, 304L, 310, 316L, 317LN, 20Cb-3, Nitronic 33, and Nitronic 40, have been evaluated to determine their permeability in cold-worked, annealed, and weld-affected zones. 310 and 20Cb-3 showed permeability after welding of less than 1.01. 1 ref., 1 fig., 1 tab

  8. Magnetic turbulence and anomalous transport

    International Nuclear Information System (INIS)

    Garbet, X.; Mourgues, F.; Samain, A.

    1990-01-01

    The self consistency conditions for magnetic turbulence are reviewed. The main features of magnetic topology involving stochastic flux lines are summarized. Two driving sources are considered: thermal effects which require large scale residual islands and electron diamagnetism which involves fluctuation scales smaller than the ion Larmor radius and a β p threshold of order one. Stability criteria and transport coefficients are given

  9. Modeling spin magnetization transport in a spatially varying magnetic field

    International Nuclear Information System (INIS)

    Picone, Rico A.R.; Garbini, Joseph L.; Sidles, John A.

    2015-01-01

    We present a framework for modeling the transport of any number of globally conserved quantities in any spatial configuration and apply it to obtain a model of magnetization transport for spin-systems that is valid in new regimes (including high-polarization). The framework allows an entropy function to define a model that explicitly respects the laws of thermodynamics. Three facets of the model are explored. First, it is expressed as nonlinear partial differential equations that are valid for the new regime of high dipole-energy and polarization. Second, the nonlinear model is explored in the limit of low dipole-energy (semi-linear), from which is derived a physical parameter characterizing separative magnetization transport (SMT). It is shown that the necessary and sufficient condition for SMT to occur is that the parameter is spatially inhomogeneous. Third, the high spin-temperature (linear) limit is shown to be equivalent to the model of nuclear spin transport of Genack and Redfield (1975) [1]. Differences among the three forms of the model are illustrated by numerical solution with parameters corresponding to a magnetic resonance force microscopy (MRFM) experiment (Degen et al., 2009 [2]; Kuehn et al., 2008 [3]; Sidles et al., 2003 [4]; Dougherty et al., 2000 [5]). A family of analytic, steady-state solutions to the nonlinear equation is derived and shown to be the spin-temperature analog of the Langevin paramagnetic equation and Curie's law. Finally, we analyze the separative quality of magnetization transport, and a steady-state solution for the magnetization is shown to be compatible with Fenske's separative mass transport equation (Fenske, 1932 [6]). - Highlights: • A framework for modeling the transport of conserved magnetic and thermodynamic quantities in any spatial configuration. • A thermodynamically grounded model of spin magnetization transport valid in new regimes, including high-polarization. • Analysis of the separative quality of

  10. Modeling spin magnetization transport in a spatially varying magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Picone, Rico A.R., E-mail: rpicone@stmartin.edu [Department of Mechanical Engineering, University of Washington, Seattle (United States); Garbini, Joseph L. [Department of Mechanical Engineering, University of Washington, Seattle (United States); Sidles, John A. [Department of Orthopædics, University of Washington, Seattle (United States)

    2015-01-15

    We present a framework for modeling the transport of any number of globally conserved quantities in any spatial configuration and apply it to obtain a model of magnetization transport for spin-systems that is valid in new regimes (including high-polarization). The framework allows an entropy function to define a model that explicitly respects the laws of thermodynamics. Three facets of the model are explored. First, it is expressed as nonlinear partial differential equations that are valid for the new regime of high dipole-energy and polarization. Second, the nonlinear model is explored in the limit of low dipole-energy (semi-linear), from which is derived a physical parameter characterizing separative magnetization transport (SMT). It is shown that the necessary and sufficient condition for SMT to occur is that the parameter is spatially inhomogeneous. Third, the high spin-temperature (linear) limit is shown to be equivalent to the model of nuclear spin transport of Genack and Redfield (1975) [1]. Differences among the three forms of the model are illustrated by numerical solution with parameters corresponding to a magnetic resonance force microscopy (MRFM) experiment (Degen et al., 2009 [2]; Kuehn et al., 2008 [3]; Sidles et al., 2003 [4]; Dougherty et al., 2000 [5]). A family of analytic, steady-state solutions to the nonlinear equation is derived and shown to be the spin-temperature analog of the Langevin paramagnetic equation and Curie's law. Finally, we analyze the separative quality of magnetization transport, and a steady-state solution for the magnetization is shown to be compatible with Fenske's separative mass transport equation (Fenske, 1932 [6]). - Highlights: • A framework for modeling the transport of conserved magnetic and thermodynamic quantities in any spatial configuration. • A thermodynamically grounded model of spin magnetization transport valid in new regimes, including high-polarization. • Analysis of the separative quality of

  11. A 'V' shaped superconducting levitation module for lift and guidance of a magnetic transportation system

    Energy Technology Data Exchange (ETDEWEB)

    D' Ovidio, G. [Transportation Area - DAU, University of L' Aquila, Poggio di Roio, 67040 L' Aquila (Italy)], E-mail: dovidio@dau.ing.univaq.it; Crisi, F.; Lanzara, G. [Transportation Area - DAU, University of L' Aquila, Poggio di Roio, 67040 L' Aquila (Italy)

    2008-07-15

    A novel, YBCO based, magnetic transportation system (MagTranS) is presented and described. The feasibility of this system has been successfully tested and confirmed in a laboratory using a scaled demonstrator system. The MagTranS levitation system uses a stable, self-balancing 'V' shaped superconducting module for both lift and guidance of vehicles. The work concept of the MagTranS levitation module is described and differences with regards to the maglev current systems are highlighted. The results of levitation tests performed using a measurement set-up are presented and discussed. Lastly, levitation module performance studies are also carried out using numerical finite element analysis.

  12. The origin of fluctuations and cross-field transport in idealized magnetic confinement systems

    International Nuclear Information System (INIS)

    Riviere, A.C.; Ashby, D.E.T.F.; Cordey, J.G.; Edlington, T.; Rusbridge, M.G.

    1981-01-01

    The study of plasma fluctuations and confinement in idealized systems such as octupoles and levitrons has contributed to the understanding of cross-field transport processes. The linear theory of plasma instabilities that cause fluctuations can predict growth rates and wavelengths around lines of force. However, the theoretical prediction of cross-field transport coefficient is restricted to quasilinear estimates which usually far exceed the measured values. A general view of the results from octupole and levitron experiments shows that under collisional conditions the diffusion coefficient scales in the same way as classical collisional diffusion. Agreement is closely approached in many cases, sometimes even in the presence of fluctuations. Under collisionless conditions, Bohm diffusion scaling is found in the few cases where the scaling law has been determined. There is also experimental and theoretical evidence that long-wavelength low-frequency electric fields (convection cells) can be generated nonlinearly from high-frequency fluctuations and can contribute to cross-field transport. (author)

  13. Magnet Systems

    Data.gov (United States)

    Federal Laboratory Consortium — Over the decades, Fermilab has been responsible for the design, construction, test and analysis of hundreds of conventional and superconducting accelerator magnets...

  14. Magnetic Particles as Multifunctional Transport Carriers and Fluid Drivers in Micro Systems

    NARCIS (Netherlands)

    Derks, R.J.S.; Frijns, A.J.H.; Prins, M.W.J.; Dietzel, A.H.

    2008-01-01

    Magnetic actuation principles using superparamagnetic particles suspended in a fluid are studied in this paper. Two experimental setups for different magnetic field settings are designed and fabricated. On the basis of optical velocity measurements, the induced behavior of single and ordered chains

  15. Modeling spin magnetization transport in a spatially varying magnetic field

    Science.gov (United States)

    Picone, Rico A. R.; Garbini, Joseph L.; Sidles, John A.

    2015-01-01

    We present a framework for modeling the transport of any number of globally conserved quantities in any spatial configuration and apply it to obtain a model of magnetization transport for spin-systems that is valid in new regimes (including high-polarization). The framework allows an entropy function to define a model that explicitly respects the laws of thermodynamics. Three facets of the model are explored. First, it is expressed as nonlinear partial differential equations that are valid for the new regime of high dipole-energy and polarization. Second, the nonlinear model is explored in the limit of low dipole-energy (semi-linear), from which is derived a physical parameter characterizing separative magnetization transport (SMT). It is shown that the necessary and sufficient condition for SMT to occur is that the parameter is spatially inhomogeneous. Third, the high spin-temperature (linear) limit is shown to be equivalent to the model of nuclear spin transport of Genack and Redfield (1975) [1]. Differences among the three forms of the model are illustrated by numerical solution with parameters corresponding to a magnetic resonance force microscopy (MRFM) experiment (Degen et al., 2009 [2]; Kuehn et al., 2008 [3]; Sidles et al., 2003 [4]; Dougherty et al., 2000 [5]). A family of analytic, steady-state solutions to the nonlinear equation is derived and shown to be the spin-temperature analog of the Langevin paramagnetic equation and Curie's law. Finally, we analyze the separative quality of magnetization transport, and a steady-state solution for the magnetization is shown to be compatible with Fenske's separative mass transport equation (Fenske, 1932 [6]).

  16. Directed Magnetic Particle Transport above Artificial Magnetic Domains Due to Dynamic Magnetic Potential Energy Landscape Transformation.

    Science.gov (United States)

    Holzinger, Dennis; Koch, Iris; Burgard, Stefan; Ehresmann, Arno

    2015-07-28

    An approach for a remotely controllable transport of magnetic micro- and/or nanoparticles above a topographically flat exchange-bias (EB) thin film system, magnetically patterned into parallel stripe domains, is presented where the particle manipulation is achieved by sub-mT external magnetic field pulses. Superparamagnetic core-shell particles are moved stepwise by the dynamic transformation of the particles' magnetic potential energy landscape due to the external magnetic field pulses without affecting the magnetic state of the thin film system. The magnetic particle velocity is adjustable in the range of 1-100 μm/s by the design of the substrate's magnetic field landscape (MFL), the particle-substrate distance, and the magnitude of the applied external magnetic field pulses. The agglomeration of magnetic particles is avoided by the intrinsic magnetostatic repulsion of particles due to the parallel alignment of the particles' magnetic moments perpendicular to the transport direction and parallel to the surface normal of the substrate during the particle motion. The transport mechanism is modeled by a quantitative theory based on the precise knowledge of the sample's MFL and the particle-substrate distance.

  17. Plasma transport through magnetic boundaries

    International Nuclear Information System (INIS)

    Treumann, R.A.

    1992-01-01

    We examine the overall plasma diffusion processes across tangential discontinuities of which the best known example is the Earth's magnetopause during northward interplanetary magnetic field conditions. The existence of the low latitude boundary layer (LLBL) adjacent to the magnetopause during those periods is ample evidence for the presence of so far poorly defined and understood entry processes acting at the magnetopause. We conclude that microscopic instabilities are probably not efficient enough to account for the LLBL. They affect only a small number of resonant particles. It is argued that macroscopic nonresonant turbulence is the most probable mechanism for plasma transport

  18. Magnetic resonance imaging and relaxometry to study water transport mechanisms in a commercially available gastrointestinal therapeutic system (GITS) tablet.

    Science.gov (United States)

    Broadbent, Amber L; Fell, Rob J; Codd, Sarah L; Lightley, Kim A; Konagurthu, Sanjay; Koehler-King, Dory G; Seymour, Joseph D

    2010-09-15

    The hydration of 4 mg Cardura XL (Pfizer), a commercially available gastrointestinal therapeutic system (GITS) tablet, was investigated using magnetic resonance imaging (MRI). A short echo time (T(e)=2.81 ms) technique for MRI of the hydration of a GITS tablet was implemented. From the MR images, signal intensity profiles were generated and interpreted in the context of diffusive and osmotic transport mechanisms. A distinct transition from diffusive to osmotic transport was measured at a timescale relevant to the measured drug release time. Diffusion and osmotic rate coefficients for water in the drug and polymer sweller layers of the tablet were quantified. Spin-lattice T(1) and spin-spin T(2) relaxation times of the water signal from within the tablet were measured as a function of hydration time in order to incorporate the effects of relaxation into interpretation of signal intensity and provide unique information on the distribution of water in different physical and chemical environments within the tablet. Copyright 2010 Elsevier B.V. All rights reserved.

  19. Beam transport magnets for CEBAF

    International Nuclear Information System (INIS)

    Harwood, L.H.; Biallas, G.; Boyce, J.R.; Heilbrunn, W.; Johnson, K.; York, R.C.

    1989-01-01

    With respect to the optical system, the challenging parameters of the Continuous Electron Beam Accelerator Facility (CEBAF), a five pass recirculating electron linac, are the design goals for the emittance and energy spread of its beam. The design goals are an emittance of 2 /times/ 10/sup /minus/9/ m-rad at E 0 ≤ 0.8 kG), 390 major dipoles (/ell/ = 1, 2, and 3 m; 2 ≤ B 0 ≤ 6 kG); 707 quadrupoles (0.15, 0.30, 0.6 m; B 0 ≤ 4 kG), 96 sextupoles (/ell/ = 0.3 m, B 0 ≤ 0.2 kG), 26 septa (/ell/ = 1, 2 m; 0.3 ≤ B 0 ≤ 6 kG), and one lambertson septum (/ell/ = 1 m; B 0 ≅ 4 kG), for a total of 2267 individual magnets. Furthermore, the fact that the quadrupoles, sextupoles, and correctors are to be individually powered to provide flexibility in tuning the optics lattice leads to restrictions on their design parameters. To ensure that the required magnetic parameters are achieved, all magnets will be magnetically mapped before installation. Therefore, systems to accurately and rapidly measure the multipoles and major dipoles are required. In this paper, present planning and the results of tests performed on the system to date are outlined. 5 refs., 4 figs

  20. Plasma transport in mixed magnetic topologies

    International Nuclear Information System (INIS)

    Hegna, C.C.; Callen, J.D.

    1992-12-01

    A simple model is introduced to illustrate some features concerning anomalous transport associated with magnetic turbulence. For magnetic topologies that are described as bands of stochasticity separated by regions with good flux surfaces, the transport coefficients deviate significantly from those describing completely stochastic magnetic fields. It is possible to have the electron heat diffusivity exceed a runaway electron diffusion coefficient, despite the existence of widespread magnetic stochasticity. Comparing the ratios of transport coefficients is not an accurate way to determine whether anomalous plasma transport is controlled by electrostatic or electromagnetic fluctuations

  1. Nonlinear electron transport in magnetized laser plasmas

    International Nuclear Information System (INIS)

    Kho, T.H.; Haines, M.G.

    1986-01-01

    Electron transport in a magnetized plasma heated by inverse bremsstrahlung is studied numerically using a nonlinear Fokker--Planck model with self-consistent E and B fields. The numerical scheme is described. Nonlocal transport is found to alter many of the transport coefficients derived from linear transport theory, in particular, the Nernst and Righi--Leduc effects, in addition to the perpendicular heat flux q/sub perpendicular/, are substantially reduced near critical surface. The magnetic field, however, remains strongly coupled to the nonlinear q/sub perpendicular/ and, as has been found in hydrosimulations, convective amplification of the magnetic field occurs in the overdense plasma

  2. Magnetic and magneto-transport properties of double perovskite Ba{sub 2-x}Sr{sub x}FeMoO{sub 6} system

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Vibhav; Verma, Vivek; Aloysius, R.P. [National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi-110012 (India); Bhalla, G.L. [Department of Physics and Astrophysics, Delhi University, Delhi (India); Awana, V.P.S.; Kishan, H. [National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi-110012 (India); Kotnala, R.K. [National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi-110012 (India)], E-mail: rkkotnala@gmail.com

    2009-07-15

    The structural magnetic and magneto-transport properties of double perovskite system Ba{sub 2-x}Sr{sub x}FeMoO{sub 6} (0{<=}x{<=}1.0) prepared in bulk polycrystalline form are reported in this paper. X-ray diffraction analysis showed that samples are single phase and the lattice constants decreases with increase in the Sr content. The degree of Fe-Mo ordering has been found decreasing in the series with an increase in the Sr content. Parent compound Ba{sub 2}FeMoO{sub 6} exhibits saturation magnetic moment value of 3.54 {mu}{sub B}/f.u. at 85 K in a magnetic field of 6000 Oe. Temperature dependence of resistivity shows metallic behavior for all the samples. The magneto-resistance (MR) of the compound with x=0.4 is higher than that of the other samples. At room temperature this system shows a saturation magnetization value of 1.73 {mu}{sub B}/f.u. and MR value of 7.08% (1 T). The observed variations in the structural and magnetic properties are attributed to the change of chemical pressure due to the substitution of Sr in place of Ba. The effect of antisite disorder (ASD) defects on magneto-transport properties is studied in more detail.

  3. Magnetic method for stimulating transport in fluids

    Science.gov (United States)

    Martin, James E.; Solis, Kyle J.

    2016-10-18

    A method for producing mass and heat transport in fluids, wherein the method does not rely on conventional convection, that is, it does not require gravity, a thermal gradient, or a magnetic field gradient. This method gives rise to a unique class of vigorous, field-controllable flow patterns termed advection lattices. The advection lattices can be used to transport heat and/or mass in any desired direction using only magnetic fields.

  4. Plasma transport across a braided magnetic field

    International Nuclear Information System (INIS)

    Stix, T.H.

    1978-01-01

    Simple fluid and particle models are used to estimate the transport of density, current, and electron heat for a plasma immersed in a region through which magnetic lines of force meander in a stochastic fashion and in which magnetic surfaces are destroyed. (author)

  5. Handbook of spin transport and magnetism

    CERN Document Server

    Tsymbal, Evgeny Y

    2011-01-01

    In the past several decades, the research on spin transport and magnetism has led to remarkable scientific and technological breakthroughs, including Albert Fert and Peter Grünberg's Nobel Prize-winning discovery of giant magnetoresistance (GMR) in magnetic metallic multilayers. Handbook of Spin Transport and Magnetism provides a comprehensive, balanced account of the state of the art in the field known as spin electronics or spintronics. It reveals how key phenomena first discovered in one class of materials, such as spin injection in metals, have been revisited decades later in other materia

  6. Transportation System Requirements Document

    International Nuclear Information System (INIS)

    1993-09-01

    This Transportation System Requirements Document (Trans-SRD) describes the functions to be performed by and the technical requirements for the Transportation System to transport spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from Purchaser and Producer sites to a Civilian Radioactive Waste Management System (CRWMS) site, and between CRWMS sites. The purpose of this document is to define the system-level requirements for Transportation consistent with the CRWMS Requirement Document (CRD). These requirements include design and operations requirements to the extent they impact on the development of the physical segments of Transportation. The document also presents an overall description of Transportation, its functions, its segments, and the requirements allocated to the segments and the system-level interfaces with Transportation. The interface identification and description are published in the CRWMS Interface Specification

  7. Transportation studies: 40-MM collider dipole magnets

    International Nuclear Information System (INIS)

    Daly, E.

    1992-01-01

    Several fully functional 40-mm Collider Dipole Magnets (CDM) were instrumented with accelerometers to monitor shock and vibration loads during transport. The magnets were measured with optical tooling telescopes before and after transport. Changes in mechanical alignment due to shipping and handling were determined. The mechanical stability of the cryogen lines were checked using the same method. Field quality and dipole angle were measured warm before and after transport to determine changes in these parameters. Power spectra were calculated for accelerometers located on the cold mass, vacuum vessel, and trailer bed. Where available, plots of field quality and dipole roll both before and after were created. Shipping loads measured were largest in the vertical direction, where most of the structural deformation of the magnet was evident. It was not clear that magnetic performance was affected by the shipping and handling environment

  8. Magnetic-flutter-induced pedestal plasma transport

    International Nuclear Information System (INIS)

    Callen, J.D.; Hegna, C.C.; Cole, A.J.

    2013-01-01

    Plasma toroidal rotation can limit reconnection of externally applied resonant magnetic perturbation (RMP) fields δB on rational magnetic flux surfaces. Hence it causes the induced radial perturbations δB ρ to be small there, thereby inhibiting magnetic island formation and stochasticity at the top of pedestals in high (H-mode) confinement tokamak plasmas. However, the δB ρ s induced by RMPs increase away from rational surfaces and are shown to induce significant sinusoidal radial motion (flutter) of magnetic field lines with a radial extent that varies linearly with δB ρ and inversely with distance from the rational surface because of the magnetic shear. This produces a radial electron thermal diffusivity that is (1/2)(δB ρ /B 0 ) 2 times a kinetically derived, electron-collision-induced, magnetic-shear-reduced, effective parallel electron thermal diffusivity in the absence of magnetic stochasticity. These low collisionality flutter-induced transport processes and thin magnetic island effects are shown to be highly peaked in the vicinity of rational surfaces at the top of low collisionality pedestals. However, the smaller but finite level of magnetic-flutter-induced electron heat transport midway between rational surfaces is the primary factor that determines the electron temperature difference between rational surfaces at the pedestal top. The magnetic-flutter-induced non-ambipolar electron density transport can be large enough to push the plasma toward an electron density transport root. Requiring ambipolar density transport is shown to determine the radial electric field, the plasma toroidal rotation (via radial force balance), a reduced electron thermal diffusivity and increased ambipolar density transport in the pedestal. At high collisionality the various flutter effects are less strongly peaked at rational surfaces and generally less significant. They are thus less likely to exhibit flutter-induced resonant behaviour and transition toward an

  9. Magnetic-flutter-induced pedestal plasma transport

    Science.gov (United States)

    Callen, J. D.; Hegna, C. C.; Cole, A. J.

    2013-11-01

    Plasma toroidal rotation can limit reconnection of externally applied resonant magnetic perturbation (RMP) fields δB on rational magnetic flux surfaces. Hence it causes the induced radial perturbations δBρ to be small there, thereby inhibiting magnetic island formation and stochasticity at the top of pedestals in high (H-mode) confinement tokamak plasmas. However, the δBρs induced by RMPs increase away from rational surfaces and are shown to induce significant sinusoidal radial motion (flutter) of magnetic field lines with a radial extent that varies linearly with δBρ and inversely with distance from the rational surface because of the magnetic shear. This produces a radial electron thermal diffusivity that is (1/2)(δBρ/B0)2 times a kinetically derived, electron-collision-induced, magnetic-shear-reduced, effective parallel electron thermal diffusivity in the absence of magnetic stochasticity. These low collisionality flutter-induced transport processes and thin magnetic island effects are shown to be highly peaked in the vicinity of rational surfaces at the top of low collisionality pedestals. However, the smaller but finite level of magnetic-flutter-induced electron heat transport midway between rational surfaces is the primary factor that determines the electron temperature difference between rational surfaces at the pedestal top. The magnetic-flutter-induced non-ambipolar electron density transport can be large enough to push the plasma toward an electron density transport root. Requiring ambipolar density transport is shown to determine the radial electric field, the plasma toroidal rotation (via radial force balance), a reduced electron thermal diffusivity and increased ambipolar density transport in the pedestal. At high collisionality the various flutter effects are less strongly peaked at rational surfaces and generally less significant. They are thus less likely to exhibit flutter-induced resonant behaviour and transition toward an electron

  10. Neoclassical theory of transport processes in toroidal magnetic confinement systems, with emphasis on non-axisymmetric configurations

    International Nuclear Information System (INIS)

    Kovrizhnykh, L.M.

    1984-01-01

    The paper constitutes a review of the neoclassical theory of transport processes in the different types of toroidal magnetic configuration now being used to study the possibility of producing a controlled thermonuclear reaction. Owing to the abundance of the material that has accumulated in recent years and the large number of parameters involved in the problem, it has not been possible to present all the mathematical calculations in detail while confining the results to a few definitive expressions. The general approach to a solution of the problem and its key aspects have been discussed as fully as possible, and a number of definitive results are presented. In the review, a history of the subject and an account of its present status are given, the problem itself is formulated, the basic equations are discussed and analytical solution methods are described. Definitive expressions are given for cross-field particle and energy fluxes, the bootstrap current and conductivity, all of which are required to solve the particle and heat balance equations in magnetic confinement devices. The results are presented in a relatively simple form which is convenient for analysis of the experimental data and are accompanied by tables containing numerical values for the universal coefficients in the definitive expressions. The review is aimed at both theoreticians and experimenters working in high-temperature plasma physics and controlled thermonuclear fusion. (author)

  11. Modular tokamak magnetic system

    International Nuclear Information System (INIS)

    Yang, T.F.

    1988-01-01

    This patent describes a tokamak reactor including a vacuum vessel, toroidal confining magnetic field coils disposed concentrically around the minor radius of the vacuum vessel, and poloidal confining magnetic field coils, an ohmic heating coil system comprising at least one magnetic coil disposed concentrically around a toroidal field coil, wherein the magnetic coil is wound around the toroidal field coil such that the ohmic heating coil enclosed the toroidal field coil

  12. Magnetic turbulent electron transport in a reversed field pinch

    International Nuclear Information System (INIS)

    Schoenberg, K.; Moses, R.

    1990-01-01

    A model of magnetic turbulent electron transport is presented. The model, based on the thermal conduction theory of Rechester and Rosenbluth, entails a Boltzmann description of electron dynamics in the long mean-free-path limit and quantitatively describes the salient features of superthermal electron measurements in the RFP edge plasma. Included are predictions of the mean superthermal electron energy, current density, and power flux asymmetry. A discussion of the transport model, the assumptions implicit in the model, and the relevance of this work to more general issue of magnetic turbulent transport in toroidal systems is presented. 32 refs., 3 figs

  13. Magnetic fields for transporting charged beams

    International Nuclear Information System (INIS)

    Parzen, G.

    1976-01-01

    The transport of charged particle beams requires magnetic fields that must be shaped correctly and very accurately. During the last 20 years or so, many studies have been made, both analytically and through the use of computer programs, of various magnetic shapes that have proved to be useful. Many of the results for magnetic field shapes can be applied equally well to electric field shapes. A report is given which gathers together the results that have more general significance and would be useful in designing a configuration to produce a desired magnetic field shape. The field shapes studied include the fields in dipoles, quadrupoles, sextupoles, octupoles, septum magnets, combined-function magnets, and electrostatic septums. Where possible, empirical formulas are proposed, based on computer and analytical studies and on magnetic field measurements. These empirical formulas are often easier to use than analytical formulas and often include effects that are difficult to compute analytically. In addition, results given in the form of tables and graphs serve as illustrative examples. The field shapes studied include uniform fields produced by window-frame magnets, C-magnets, H-magnets, and cosine magnets; linear fields produced by various types of quadrupoles; quadratic and cubic fields produced by sextupoles and octupoles; combinations of uniform and linear fields; and septum fields with sharp boundaries

  14. Intelligent Freigth Transport Systems

    DEFF Research Database (Denmark)

    Overø, Helene Martine; Larsen, Allan; Røpke, Stefan

    2009-01-01

    is to enhance the efficiency and lower the environmental impact in freight transport. In this paper, a pilot project involving real-time waste collection at a Danish waste collection company is described, and a solution approach is proposed. The problem corresponds to the dynamic version of the waste collection......The Danish innovation project entitled “Intelligent Freight Transport Systems” aims at developing prototype systems integrating public intelligent transport systems (ITS) with the technology in vehicles and equipment as well as the IT-systems at various transport companies. The objective...

  15. Superparamagnetic microbead transport induced by a magnetic field on large-area magnetic antidot arrays

    Science.gov (United States)

    Ouk, Minae; Beach, Geoffrey S. D.

    2017-12-01

    A method is presented for directed transport of superparamagnetic microbeads (SPBs) on magnetic antidot patterned substrates by applying a rotating elliptical magnetic field. We find a critical frequency for transport, beyond which the bead dynamics transitions from stepwise locomotion to local oscillation. We also find that the out-of-plane (HOOP) and in-plane (HIP) field magnitudes play crucial roles in triggering bead motion. Namely, we find threshold values in HOOP and HIP that depend on bead size, which can be used to independently and remotely address specific bead populations in a multi-bead mixture. These behaviors are explained in terms of the dynamic potential energy lansdscapes computed from micromagnetic simulations of the substrate magnetization configuration. Finally, we show that large-area magnetic patterns suitable for particle transport and sorting can be fabricated through a self-assembly lithography technique, which provides a simple, cost-effective means to integrate magnetic actuation into microfluidic systems.

  16. Collapse of ferromagnetism in itinerant-electron system: A magnetic, transport properties, and high pressure study of (Hf,Ta)Fe2 compounds

    Science.gov (United States)

    Diop, L. V. B.; Kastil, J.; Isnard, O.; Arnold, Z.; Kamarad, J.

    2014-10-01

    The magnetism and transport properties were studied for Laves (Hf,Ta)Fe2 itinerant-electron compounds, which exhibit a temperature-induced first-order transition from the ferromagnetic (FM) to the antiferromagnetic (AFM) state upon heating. At finite temperatures, the field-induced metamagnetic phase transition between the AFM and FM has considerable effects on the transport properties of these model metamagnetic compounds. A large negative magnetoresistance of about 14% is observed in accordance with the metamagnetic transition. The magnetic phase diagram is determined for the Laves Hf1-xTaxFe2 series and its Ta concentration dependence discussed. An unusual behavior is revealed in the paramagnetic state of intermediate compositions, it gives rise to the rapid increase and saturation of the local spin fluctuations of the 3d electrons. This new result is analysed in the frame of the theory of Moriya. For a chosen composition Hf0.825Ta0.175Fe2, exhibiting such remarkable features, a detailed investigation is carried out under hydrostatic pressure up to 1 GPa in order to investigate the volume effect on the magnetic properties. With increasing pressure, the magnetic transition temperature TFM-AFM from ferromagnetic to antiferromagnetic order decreases strongly non-linearly and disappears at a critical pressure of 0.75 GPa. In the pressure-induced AFM state, the field-induced first-order AFM-FM transition appears and the complex temperature dependence of the AFM-FM transition field is explained by the contribution from both the magnetic and elastic energies caused by the significant temperature variation of the amplitude of the local Fe magnetic moment. The application of an external pressure leads also to the progressive decrease of the Néel temperature TN. In addition, a large pressure effect on the spontaneous magnetization MS for pressures below 0.45 GPa, dln(Ms)/dP = -6.3 × 10-2 GPa-1 was discovered. The presented results are consistent with Moriya

  17. TPC magnet cryogenic system

    International Nuclear Information System (INIS)

    Green, M.A.; Burns, W.A.; Taylor, J.D.; Van Slyke, H.W.

    1980-03-01

    The Time Projection Chamber (TPC) magnet at LBL and its compensation solenoids are adiabatically stable superconducting solenoid magnets. The cryogenic system developed for the TPC magnet is discussed. This system uses forced two-phase tubular cooling with the two cryogens in the system. The liquid helium and liquid nitrogen are delivered through the cooled load by forced tubular flow. The only reservoirs of liquid cryogen exist in the control dewar (for liquid helium) and the conditioner dewar (for liquid nitrogen). The operation o these systems during virtually all phases of system operation are described. Photographs and diagrams of various system components are shown, and cryogenic system data are presented in the following sections: (1) heat leaks into the TPC coil package and the compensation solenoids; (2) heat leaks to various components of the TPC magnet cryogenics system besides the magnets and control dewar; (3) the control dewar and its relationship to the rest of the system; (4) the conditioner system and its role in cooling down the TPC magnet; (5) gas-cooled electrical leads and charging losses; and (6) a summation of the liquid helium and liquid nitrogen requirements for the TPC superconducting magnet system

  18. Effects of magnetic drift tangential to magnetic surfaces on neoclassical transport in non-axisymmetric plasmas

    International Nuclear Information System (INIS)

    Matsuoka, Seikichi; Satake, Shinsuke; Kanno, Ryutaro; Sugama, Hideo

    2015-01-01

    In evaluating neoclassical transport by radially local simulations, the magnetic drift tangential to a flux surface is usually ignored in order to keep the phase-space volume conservation. In this paper, effect of the tangential magnetic drift on the local neoclassical transport is investigated. To retain the effect of the tangential magnetic drift in the local treatment of neoclassical transport, a new local formulation for the drift kinetic simulation is developed. The compressibility of the phase-space volume caused by the tangential magnetic drift is regarded as a source term for the drift kinetic equation, which is solved by using a two-weight δf Monte Carlo method for non-Hamiltonian system [G. Hu and J. A. Krommes, Phys. Plasmas 1, 863 (1994)]. It is demonstrated that the effect of the drift is negligible for the neoclassical transport in tokamaks. In non-axisymmetric systems, however, the tangential magnetic drift substantially changes the dependence of the neoclassical transport on the radial electric field E r . The peaked behavior of the neoclassical radial fluxes around E r  =   0 observed in conventional local neoclassical transport simulations is removed by taking the tangential magnetic drift into account

  19. Effects of magnetic drift tangential to magnetic surfaces on neoclassical transport in non-axisymmetric plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Seikichi, E-mail: matsuoka@rist.or.jp [Research Organization for Information Science and Technology, 6F Kimec-Center Build., 1-5-2 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047 (Japan); Satake, Shinsuke; Kanno, Ryutaro [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Department of Fusion Science, SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Sugama, Hideo [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)

    2015-07-15

    In evaluating neoclassical transport by radially local simulations, the magnetic drift tangential to a flux surface is usually ignored in order to keep the phase-space volume conservation. In this paper, effect of the tangential magnetic drift on the local neoclassical transport is investigated. To retain the effect of the tangential magnetic drift in the local treatment of neoclassical transport, a new local formulation for the drift kinetic simulation is developed. The compressibility of the phase-space volume caused by the tangential magnetic drift is regarded as a source term for the drift kinetic equation, which is solved by using a two-weight δf Monte Carlo method for non-Hamiltonian system [G. Hu and J. A. Krommes, Phys. Plasmas 1, 863 (1994)]. It is demonstrated that the effect of the drift is negligible for the neoclassical transport in tokamaks. In non-axisymmetric systems, however, the tangential magnetic drift substantially changes the dependence of the neoclassical transport on the radial electric field E{sub r}. The peaked behavior of the neoclassical radial fluxes around E{sub r }={sub  }0 observed in conventional local neoclassical transport simulations is removed by taking the tangential magnetic drift into account.

  20. The magnet database system

    International Nuclear Information System (INIS)

    Ball, M.J.; Delagi, N.; Horton, B.; Ivey, J.C.; Leedy, R.; Li, X.; Marshall, B.; Robinson, S.L.; Tompkins, J.C.

    1992-01-01

    The Test Department of the Magnet Systems Division of the Superconducting Super Collider Laboratory (SSCL) is developing a central database of SSC magnet information that will be available to all magnet scientists at the SSCL or elsewhere, via network connections. The database contains information on the magnets' major components, configuration information (specifying which individual items were used in each cable, coil, and magnet), measurements made at major fabrication stages, and the test results on completed magnets. These data will facilitate the correlation of magnet performance with the properties of its constituents. Recent efforts have focused on the development of procedures for user-friendly access to the data, including displays in the format of the production open-quotes travelerclose quotes data sheets, standard summary reports, and a graphical interface for ad hoc queues and plots

  1. TRANSPORTATION SYSTEM REQUIREMENTS DOCUMENT

    International Nuclear Information System (INIS)

    2004-01-01

    This document establishes the Transportation system requirements for the U.S. Department of Energy's (DOE's) Civilian Radioactive Waste Management System (CRWMS). These requirements are derived from the Civilian Radioactive Waste Management System Requirements Document (CRD). The Transportation System Requirements Document (TSRD) was developed in accordance with LP-3.1Q-OCRWM, Preparation, Review, and Approval of Office of National Transportation Level-2 Baseline Requirements. As illustrated in Figure 1, the TSRD forms a part of the DOE Office of Civilian Radioactive Waste Management (OCRWM) Technical Baseline

  2. Passive magnetic bearing system

    Science.gov (United States)

    Post, Richard F.

    2014-09-02

    An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

  3. Phenomena of charged particles transport in variable magnetic fields

    International Nuclear Information System (INIS)

    Savane, Sy Y.; Faza Barry, M.; Vladmir, L.; Diaby, I.

    2002-11-01

    This present work is dedicated to the study of the dynamical phenomena for the transport of ions in the presence of variable magnetic fields in front of the Jupiter wave shock. We obtain the spectrum of the accelerated ions and we study the conditions of acceleration by solving the transport equation in the planetocentric system. We discuss the theoretical results obtained and make a comparison with the experimental parameters in the region of acceleration behind the Jupiter wave shock. (author)

  4. Electrical railway transportation systems

    CERN Document Server

    Brenna, Morris; Zaninelli, Dario

    2018-01-01

    Allows the reader to deepen their understanding of various technologies for both fixed power supply installations of railway systems and for railway rolling stock. This book explores the electric railway systems that play a crucial role in the mitigation of congestion and pollution caused by road traffic. It is divided into two parts: the first covering fixed power supply systems, and the second concerning the systems for railway rolling stock. In particular, after a historical introduction to the framework of technological solutions in current use, the authors investigate electrification systems for the power supply of rail vehicles, trams, and subways. Electrical Railway Transportation Systems explores the direct current systems used throughout the world for urban and suburban transport, which are also used in various countries for regional transport. It provides a study of alternating current systems, whether for power supply frequency or for special railway frequency, that are used around the world for ...

  5. Magnetic-field asymmetry of nonlinear thermoelectric and heat transport

    International Nuclear Information System (INIS)

    Hwang, Sun-Yong; Sánchez, David; López, Rosa; Lee, Minchul

    2013-01-01

    Nonlinear transport coefficients do not obey, in general, reciprocity relations. We here discuss the magnetic-field asymmetries that arise in thermoelectric and heat transport of mesoscopic systems. Based on a scattering theory of weakly nonlinear transport, we analyze the leading-order symmetry parameters in terms of the screening potential response to either voltage or temperature shifts. We apply our general results to a quantum Hall antidot system. Interestingly, we find that certain symmetry parameters show a dependence on the measurement configuration. (paper)

  6. A Magnetic Transport Middle Eastern Positron Beam

    International Nuclear Information System (INIS)

    Al-Qaradawi, I.Y.; Britton, D.T.; Rajaraman, R.; Abdulmalik, D.

    2008-01-01

    A magnetically guided slow positron beam is being constructed at Qatar University and is currently being optimised for regular operation. This is the first positron beam in the Middle East, as well as being the first Arabic positron beam. Novel features in the design include a purely magnetic in-line deflector, working in the solenoid guiding field, to eliminate un-moderated positrons and block the direct line of sight to the source. The impact of this all-magnetic transport on the Larmor radius and resultant beam characteristics are studied by SIMION simulations for both ideal and real life magnetic field variations. These results are discussed in light of the coupled effect arising from electrostatic beam extraction

  7. Magnetic Coordinate Systems

    Science.gov (United States)

    Laundal, K. M.; Richmond, A. D.

    2017-03-01

    Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the full IGRF into account and define magnetic latitude and longitude such that they are constant along field lines. These coordinate systems, which are useful at ionospheric altitudes, are non-orthogonal. We show how to handle vectors and vector calculus in such coordinates, and discuss how systematic errors may appear if this is not done correctly.

  8. Thermodynamic theory of transport in magnetized plasmas

    International Nuclear Information System (INIS)

    Misguich, J.H.

    1990-10-01

    Transport laws relating thermodynamic flows to forces by means of transport coefficients in a magnetized plasma are derived here from basic plasmadynamics and nonequilibrium thermodynamics. Macroscopic balance equations are derived in the first part, taking into account the energy of relative diffusion between species in an exact way. The resulting plasmadynamical equations appear to be more general than the usual ones. In the second part, the particular features of a two-temperature diffusing plasma are taken into account in deriving the balance equation for the entropy density, the differences with thermodynamics of neutral fluid mixtures or metals are explained. The general expressions obtained for the entropy production rate are used in part III to derive transport laws. Onsager symmetry relations are applied to interrelate crossed transport coefficients. Basic transport coefficients are the electrical conductivity, the thermo-electric coefficient, along with the thermal conductivities and the viscosities for each species. The slight difference between thermo-electric effect and thermo-diffusion is explained. An important resistive thermo-electric effect appears which describes crossed transport coefficients between thermal and electric flows. Because of the anisotropy introduced by the magnetic field, the transport coefficients are tensors, with non diagonal elements associated with the Hall, Nernst and Ettinghausen effects in the plasma. The field geometry and applications to several particular cases are treated explicitly in part IV, namely the neo-classical transport laws. The Ettinghausen effect appears to play an important role in the transport laws for radial electron heat flow and particle flow in confined plasmas. Practical prescriptions are given to apply the Onsager symmetry relations in a correct way

  9. Kinematics of Mass Transport Deposits revealed by magnetic fabrics

    Science.gov (United States)

    Weinberger, R.; Levi, T.; Alsop, G. I.; Marco, S.

    2017-08-01

    The internal deformation and movement directions of Mass Transport Deposits (MTDs) are key factors in understanding the kinematics and dynamics of their emplacement. Although these are relatively easy to recover from well-bedded sediments, they are more difficult to deduce from massive beds without visible strain markers. In order to test the applicability of using anisotropy of magnetic susceptibility (AMS) to determine MTD movement, we compare AMS fabrics, with structural measurements of visible kinematic indicators. Our case study involves the structural analysis of slumped lake sediments extensively exposed in MTDs within the Dead Sea Basin. Structural analyses of MTDs outcropping for >100 km reveal radial transport directions toward the basin depocenter. We show that the AMS fabrics display the same transport directions as inferred from structural analyses. Based on this similarity, we outline a robust procedure to obtain the transport direction of slumped MTDs from AMS fabrics. Variations in the magnetic fabrics and anisotropies in fold-thrust systems within the slumps match the various structural domains. We therefore suggest that magnetic fabrics and anisotropy variations in drill cores may reflect internal deformation within the slumps rather than different slumps. Obtaining magnetic fabrics from MTDs provides a viable way to infer the transport directions and internal deformation of MTDs and reconstruct the basin depocenter in ancient settings. The present results also have implications beyond the kinematics of MTDs, as their geometry resembles fold-thrust systems in other geological settings, scales, and tectonic environments.

  10. Lightweight Monorail Transport System

    Science.gov (United States)

    Weir, Harold F.; Wood, Kenneth E.; Strecker, Myron T.

    1987-01-01

    Report proposes monorail transportation system for zero-gravity environment. System carries materials and parts between locations on space station. Includes tubular rails instead of open channels usually found in overhead conveyor systems. Since resistance to torque of closed tube greater than that of open channel for same amount of material, tubular monorail designed for higher loads or for greater spacing between support points.

  11. TMX magnet control system

    International Nuclear Information System (INIS)

    Goerz, D.A.

    1978-01-01

    A control system utilizing a microcomputer has been developed that controls the power supplies driving the Tandem Mirror Experiment (TMX) magnet set and monitors magnet coil operation. The magnet set consists of 18 magnet coils that are driven by 26 dc power supplies. There are two possible modes of operation with this system: a pulse mode where the coils are pulsed on for several seconds with a dc power consumption of 16 MW; and a continuous mode where the coils can run steady state at 10 percent of maximum current ratings. The processor has been given an active control role and serves as an interface between the operator and electronic circuitry that controls the magnet power supplies. This microcomputer also collects and processes data from many analog singal monitors in the coil circuits and numerous status signals from the supplies. Placing the microcomputer in an active control role has yielded a compact, cost effective system that simplifies the magnet system operation and has proven to be very reliable. This paper will describe the TMX magnet control sytem and discuss its development

  12. A National MagLev Transportation System

    Science.gov (United States)

    Wright, Michael R.

    2003-01-01

    The case for a national high-speed magnetic-levitation (MagLev) transportation system is presented. Focus is on current issues facing the country, such as national security, the economy, transportation, technology, and the environment. NASA s research into MagLev technology for launch assist is also highlighted. Further, current socio-cultural norms regarding motor-vehicle-based transportation systems are questioned in light of the problems currently facing the U.S. The multidisciplinary benefits of a long-distance MagLev system support the idea that such a system would be an important element of a truly multimodal U.S. transportation infrastructure.

  13. Magnetic tunnel structures: Transport properties controlled by bias, magnetic field, and microwave and optical radiation

    International Nuclear Information System (INIS)

    Volkov, N.V.; Eremin, E.V.; Tarasov, A.S.; Rautskii, M.V.; Varnakov, S.N.; Ovchinnikov, S.G.; Patrin, G.S.

    2012-01-01

    Different phenomena that give rise to a spin-polarized current in some systems with magnetic tunnel junctions are considered. In a manganite-based magnetic tunnel structure in CIP geometry, the effect of current-channel switching was observed, which causes bias-driven magnetoresistance, rf rectification, and the photoelectric effect. The second system under study, ferromagnetic/insulator/semiconductor, exhibits the features of the transport properties in CIP geometry that are also related to the current-channel switching effect. The described properties can be controlled by a bias, a magnetic field, and optical radiation. At last, the third system under consideration is a cooperative assembly of magnetic tunnel junctions. This system exhibits tunnel magnetoresistance and the magnetic-field-driven microwave detection effect.

  14. Transportable criticality alarm system

    International Nuclear Information System (INIS)

    Clem, W.E.

    1988-09-01

    The Transportable Criticality Alarm System was developed at the Hanford Site in 1982 to comply with the requirements of US Department of Energy Order DOE 5480.1, 12/18/80, and ANSI/ANS-8.3- 1979. The portable unit that it replaced failed to comply with the new requirements in that it did not provide the necessary warning of malfunctions, nor did it provide the Hanford Site standard criticality alarm signal. Modern technology allowed the Transportable Criticality Alarm System to comply with the criticality requirements cited and to incorporate other features that make it more usable, maintainable, and reliable. The Transportable Criticality Alarm System (TCAS) provides temporary criticality coverage in manned areas where the facility criticality alarm system is not operable. This gamma radiation-sensitive system has been in use for the past 6 yr at the Hanford Site. 2 refs., 4 figs., 1 tab

  15. Theory of transport through molecular magnets

    Science.gov (United States)

    Schoeller, Herbert

    2007-03-01

    Quantum transport through single molecular magnets (SMM) is starting to become a new exciting field in molecular spin electronics. Recent experiments [1,2] have shown that magnetic excitations can be identified in transport measurements and that NDC effects and complete current suppression can be explained by charge dependent anisotropies. Recent theoretical investigations [3,4,5] are presented which demonstrate fingerprints of quantum tunneling of magnetization (QTM). For weak tunneling, the violation of spin-selection rules leads to the occurence of fake resonances with temperature-dependent position [3]. For strongtunneling, it is show that a pseudo spin-1/2 Kondo effect is induced by QTM. If the Kondo temperature TK is smaller than the distance to excited magnetic states, selection rules depending on spin and symmetry of the SMM are derived for the Kondo effect to occur [4]. If TK exceeds the anisotropy barrier, it is shown that a reentrant Kondo effect can be induced by application of a longitudinal magnetic field for SMM with half-integer or integer spin [5]. This effect can be used for transport spectroscopy of the various anisotropies characterizing a SMM. [1] H.B. Heersche et al., Phys. Rev. Lett. 96, 206801 (2006). [2] Moon-Ho Jo et al., Nano Lett. 6, 2014 (2006). [3] C. Romeike, M.R. Wegewijs, H. Schoeller, Phys. Rev. Lett. 96, 196805 (2006). [4] C. Romeike, M.R. Wegewijs, W. Hofstetter, H. Schoeller, Phys. Rev. Lett. 96, 196601 (2006). [5] C. Romeike, M.R. Wegewijs, W. Hofstetter, H. Schoeller, to be published in Phys. Rev. Lett., cond-mat/0605514.

  16. Pressure effects on the magnetic and transport properties of the Kondo lattice system Ce3RuSn6

    Science.gov (United States)

    Wakiya, Kazuhei; Tomaki, Takeru; Kimura, Minami; Uehara, Masatomo; Gouchi, Jun; Uwatoko, Yoshiya; Umehara, Izuru

    2018-05-01

    The magnetization and electrical resistivity of Ce3RuSn6 have been measured in the temperature range from 2 to 300 K and in the pressure range up to 1 GPa. At ambient pressure, the magnetization shows a ferromagnetic-like steep rise below 4 K. The electrical resistivity drops at TC = 3.3 K due to the magnetic transition. We found that TC is slightly enhanced by applying pressure, suggesting that this compound sits on the left side of the peak in the Doniach phase diagram.

  17. Magnetics transport aspects of EBTR reactors

    International Nuclear Information System (INIS)

    Bathke, C.G.

    1981-01-01

    The magnetic model developed for the ELMO Bumpy Torus Reactor (EBTR) study is described. A multiple-loop current simulation of toroidal-field (TF) and aspect-ratio-enhancement (ARE) coils is used to calculate the vacuum magnetic field. The bounce-averaged vertical drift velocity, v/sub y/, and poloidal drift frequency, Ω, are determined from the field topology. Upon performing the appropriate averages of v/sub y/ and Ω, the point-plasma toroidal curvature, R/sub T/, and magnetic curvature, R/sub c/, are obtained for use in modeling EBT transport. In addition, the fraction, f/sub α/, of alpha particles completing their first orbit within the plasma is calculated

  18. Operating control techniques for maglev transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, K H; Schnieder, E

    1984-06-01

    The technical and operational possibilities of magnetic levitation transport systems can only be fully exploited by introducing 'intelligent' control systems which ensure automatic and trouble-free train running. The solution of exacting requirements in the fields of traction dynamics, security and control as well as information gathering transmission and processing is an important prior condition in that respect. The authors report here on the present state of research and development in operating control techniques applicable to maglev transport systems.

  19. Design of magnetic analysis system for magnetic proton recoil spectrometer

    International Nuclear Information System (INIS)

    Qi Jianmin; Jiang Shilun; Zhou Lin; Peng Taiping

    2010-01-01

    Magnetic proton recoil (MPR) spectrometer is a novel diagnostic instrument with high performance for measurements of the neutron spectra from inertial confinement fusion (ICF) experiments and high power fusion devices. The design of the magnetic analysis system, which is a key part of the compact MPR-type spectrometer, has been completed through two-dimensional beam transport simulations and three-dimensional particle transport simulation. The analysis of the system's parameters and performances was performed, as well as system designs based on preferential principles of energy resolution, detection efficiency, and count rate, respectively. The results indicate that the magnetic analysis system can achieve a detection efficiency of 10 -5 ∼ 10 -4 level at the resolution range of 1.5% to 3.0% and fulfill the design goals of the compact MPR spectrometer. (authors)

  20. Large Superconducting Magnet Systems

    CERN Document Server

    Védrine, P.

    2014-07-17

    The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb−Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb$_{3}$Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

  1. Large Superconducting Magnet Systems

    Energy Technology Data Exchange (ETDEWEB)

    Védrine, P [Saclay (France)

    2014-07-01

    The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb−Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb3Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

  2. Magnetic Resonance Force Microscopy System

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...

  3. Blood Sample Transportation by Pneumatic Transportation Systems

    DEFF Research Database (Denmark)

    Nybo, Mads; Lund, Merete E; Titlestad, Kjell

    2018-01-01

    BACKGROUND: Pneumatic transportation systems (PTSs) are increasingly used for transportation of blood samples to the core laboratory. Many studies have investigated the impact of these systems on different types of analyses, but to elucidate whether PTSs in general are safe for transportation...... analysis, and the hemolysis index). CONCLUSIONS: Owing to their high degree of heterogeneity, the retrieved studies were unable to supply evidence for the safety of using PTSs for blood sample transportation. In consequence, laboratories need to measure and document the actual acceleration forces...

  4. Magnetic and transport properties of conjugated and cumulated molecules: the π-system enlightens part of the story

    DEFF Research Database (Denmark)

    Sarbadhikary, Prodipta; Shil, Suranjan; Misra, Anirban

    2018-01-01

    We have investigated the intramolecular magnetic exchange coupling constants (J) for a series of nitronyl nitroxide diradicals connected by a range of linear conjugated and cumulene couplers focusing on the unusual π-interaction properties within the couplers. Distance between radical centers, sp...

  5. Lunar transportation system

    Science.gov (United States)

    1993-07-01

    The University Space Research Association (USRA) requested the University of Minnesota Spacecraft Design Team to design a lunar transportation infrastructure. This task was a year long design effort culminating in a complete conceptual design and presentation at Johnson Space Center. The mission objective of the design group was to design a system of vehicles to bring a habitation module, cargo, and crew to the lunar surface from LEO and return either or both crew and cargo safely to LEO while emphasizing component commonality, reusability, and cost effectiveness. During the course of the design, the lunar transportation system (LTS) has taken on many forms. The final design of the system is composed of two vehicles, a lunar transfer vehicle (LTV) and a lunar excursion vehicle (LEV). The LTV serves as an efficient orbital transfer vehicle between the earth and the moon while the LEV carries crew and cargo to the lunar surface. Presented in the report are the mission analysis, systems layout, orbital mechanics, propulsion systems, structural and thermal analysis, and crew systems, avionics, and power systems for this lunar transportation concept.

  6. Magnetic spectrometer control system

    International Nuclear Information System (INIS)

    Lecca, L.A.; Di Paolo, Hugo; Fernandez Niello, Jorge O.; Marti, Guillermo V; Pacheco, Alberto J.; Ramirez, Marcelo

    2003-01-01

    The design and implementation of a new computerized control system for the several devices of the magnetic spectrometer at TANDAR Laboratory is described. This system, as a main difference from the preexisting one, is compatible with almost any operating systems of wide spread use available in PC. This allows on-line measurement and control of all signals from any terminal of a computer network. (author)

  7. Rail transport systems approach

    CERN Document Server

    2017-01-01

    This book shows how the systems approach is employed by scientists in various countries to solve specific problems concerning railway transport. In particular, the book describes the experiences of scientists from Romania, Germany, the Czech Republic, the UK, Russia, Ukraine, Lithuania and Poland. For many of these countries there is a problem with the historical differences between the railways. In particular, there are railways with different rail gauges, with different signaling and communication systems, with different energy supplies and, finally, with different political systems, which are reflected in the different approaches to the management of railway economies. The book’s content is divided into two main parts, the first of which provides a systematic analysis of individual means of providing and maintaining rail transport. In turn, the second part addresses infrastructure and management development, with particular attention to security issues. Though primarily written for professionals involved...

  8. Magnetic Nanostructures Spin Dynamics and Spin Transport

    CERN Document Server

    Farle, Michael

    2013-01-01

    Nanomagnetism and spintronics is a rapidly expanding and increasingly important field of research with many applications already on the market and many more to be expected in the near future. This field started in the mid-1980s with the discovery of the GMR effect, recently awarded with the Nobel prize to Albert Fert and Peter Grünberg. The present volume covers the most important and most timely aspects of magnetic heterostructures, including spin torque effects, spin injection, spin transport, spin fluctuations, proximity effects, and electrical control of spin valves. The chapters are written by internationally recognized experts in their respective fields and provide an overview of the latest status.

  9. Particle transport due to magnetic fluctuations

    International Nuclear Information System (INIS)

    Stoneking, M.R.; Hokin, S.A.; Prager, S.C.; Fiksel, G.; Ji, H.; Den Hartog, D.J.

    1994-01-01

    Electron current fluctuations are measured with an electrostatic energy analyzer at the edge of the MST reversed-field pinch plasma. The radial flux of fast electrons (E>T e ) due to parallel streaming along a fluctuating magnetic field is determined locally by measuring the correlated product e B r >. Particle transport is small just inside the last closed flux surface (Γ e,mag e,total ), but can account for all observed particle losses inside r/a=0.8. Electron diffusion is found to increase with parallel velocity, as expected for diffusion in a region of field stochasticity

  10. ESCAR superconducting magnet system

    International Nuclear Information System (INIS)

    Gilbert, W.S.; Meuser, R.B.; Pope, W.L.; Green, M.A.

    1975-01-01

    Twenty-four superconducting dipoles, each about 1 meter long, provide the guide field for the Experimental Superconducting Accelerator Ring proton accelerator--storage ring. Injection of 50 MeV protons corresponds to a 3 kG central dipole field, and a peak proton energy of 4.2 GeV corresponds to a 46 kG central field. Thirty-two quadrupoles provide focusing. The 56 superconducting magnets are contained in 40 cryostats that are cryogenically connected in a novel series ''weir'' arrangement. A single 1500 W refrigeration plant is required. Design and testing of the magnet and cryostat system are described. (U.S.)

  11. Heat transport system

    International Nuclear Information System (INIS)

    Pierce, B.L.

    1978-01-01

    A heat transport system of small size which can be operated in any orientation consists of a coolant loop containing a vaporizable liquid as working fluid and includes in series a vaporizer, a condenser and two one-way valves and a pressurizer connected to the loop between the two valves. The pressurizer may be divided into two chambers by a flexible diaphragm, an inert gas in one chamber acts as a pneumatic spring for the system. This system is suitable for use in a nuclear-powered artificial heart

  12. Bevalac beam transport system

    International Nuclear Information System (INIS)

    Avery, R.; Behrsing, G.; Morgado, R.; Rondeau, D.; Salsig, W.; Selph, F.; Staples, J.; Yourd, R.

    1975-03-01

    The Bevalac consists of, in part, a 200 meter long transfer line between the SuperHILAC and the Bevatron, which are at differing elevation. Unique features in the construction of the transfer line are described. The line, located largely outside, must cope with a natural environment. Part of the line passes through a hillside, requiring some unique support and alignment techniques. The dipoles are of the tape-wound variety and the steering magnets use printed circuit conductors. The vacuum system and an inexpensive and effective destructive monitoring system are described. (U.S.)

  13. Magnetic separation in microfluidic systems

    DEFF Research Database (Denmark)

    Smistrup, Kristian

    2007-01-01

    to facilitate real-time monitoring of the experiments. The set-up and experimental protocol are described in detail. Results are presented for ’active’ magnetic bead separators, where on-chip microfabricated electromagnets supply the magnetic field and field gradients necessary for magnetic bead separation....... It is shown conceptually how such a system can be applied for parallel biochemical processing in a microfluidic system. ’Passive’ magnetic separators are presented, where on-chip soft magnetic elements are magnetized by an external magnetic field and create strong magnetic fields and gradients inside...

  14. Third-Order Transport with MAD Input: A Computer Program for Designing Charged Particle Beam Transport Systems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Karl

    1998-10-28

    TRANSPORT has been in existence in various evolutionary versions since 1963. The present version of TRANSPORT is a first-, second-, and third-order matrix multiplication computer program intended for the design of static-magnetic beam transport systems.

  15. SUBSURFACE EMPLACEMENT TRANSPORTATION SYSTEM

    International Nuclear Information System (INIS)

    Wilson, T.; Novotny, R.

    1999-01-01

    The objective of this analysis is to identify issues and criteria that apply to the design of the Subsurface Emplacement Transportation System (SET). The SET consists of the track used by the waste package handling equipment, the conductors and related equipment used to supply electrical power to that equipment, and the instrumentation and controls used to monitor and operate those track and power supply systems. Major considerations of this analysis include: (1) Operational life of the SET; (2) Geometric constraints on the track layout; (3) Operating loads on the track; (4) Environmentally induced loads on the track; (5) Power supply (electrification) requirements; and (6) Instrumentation and control requirements. This analysis will provide the basis for development of the system description document (SDD) for the SET. This analysis also defines the interfaces that need to be considered in the design of the SET. These interfaces include, but are not limited to, the following: (1) Waste handling building; (2) Monitored Geologic Repository (MGR) surface site layout; (3) Waste Emplacement System (WES); (4) Waste Retrieval System (WRS); (5) Ground Control System (GCS); (6) Ex-Container System (XCS); (7) Subsurface Electrical Distribution System (SED); (8) MGR Operations Monitoring and Control System (OMC); (9) Subsurface Facility System (SFS); (10) Subsurface Fire Protection System (SFR); (11) Performance Confirmation Emplacement Drift Monitoring System (PCM); and (12) Backfill Emplacement System (BES)

  16. On setting magnets in the PEP beam-transport line

    International Nuclear Information System (INIS)

    Peterson, J.M.

    1979-01-01

    This paper discusses magnets in the PEP beam-transport line. Topics discussed are: conditioning, direction of excitation, rate of excitation; determination of the excitation current for the principal bend magnets; steering mechanisms; bump magnets; and determination of excitation currents of the quadrupole magnets

  17. Compact magnetic fusion systems

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K.

    1983-12-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak/sup 1/ and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics.

  18. Compact magnetic fusion systems

    International Nuclear Information System (INIS)

    Linford, R.K.

    1983-01-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak 1 and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics

  19. High magnetic field MRI system

    International Nuclear Information System (INIS)

    Maeda, Hideaki; Urata, Masami; Satoh, Kozo

    1990-01-01

    A high field superconducting magnet, 4-5 T in central magnetic field, is required for magnetic resonance spectroscopic imaging (MRSI) on 31 P, essential nuclei for energy metabolism of human body. This paper reviews superconducting magnets for high field MRSI systems. Examples of the cross-sectional image and the spectrum of living animals are shown in the paper. (author)

  20. Transport Studies of Quantum Magnetism: Physics and Methods

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minhyea [Univ. of Colorado, Boulder, CO (United States)

    2017-03-30

    The main goal of this project was to understand novel ground states of spin systems probed by thermal and electrical transport measurements. They are well-suited to characterize the nature of low-energy excitations as unique property of the ground state. More specifically, it was aimed to study the transverse electrical conductivity in the presence of non-collinear and non-coplanar spin ordering and the effects of gauge field as well as novel spin excitations as a coherent heat transport channel in insulating quantum magnets. Most of works done during the grant period focused on these topics. As a natural extension of the project's initial goals, the scope was broadened to include transport studies on the spin systems with strong spin-orbit coupling. One particular focus was an exploration of systems with strong magnetic anisotropy combined with non-trivial spin configuration. Magnetic anisotropy is directly related to implement the non-collinear spin ordering to the existing common geometry of planar devices and thus poses a significant potential. Work in this direction includes the comparison of the topological Hall signal under hydrostatic pressure and chemical doping, as well as the angular dependence dependence of the non-collinear spin ordered phase and their evolution up on temperature and field strength. Another focus was centered around the experimental identification of spin-originated heat carrying excitation in quasi two dimensional honeycomb lattice, where Kitaev type of quantum spin liquid phase is expected to emerge. In fact, when its long range magnetic order is destroyed by the applied field, we discovered anomalously large enhancement of thermal conductivity, for which proximate Kitaev excitations in field-induced spin liquid state are responsible for. This work, combined with further investigations in materials in the similar class may help establish the experimental characterization of new quantum spin liquid and their unique low energy

  1. Anomalous transport in mirror systems

    International Nuclear Information System (INIS)

    Post, R.F.

    1979-01-01

    As now being explored for fusion applications confinement systems based on the mirror principle embody two kinds of plasma regimes. These two regimes are: (a) high-beta plasmas, stabilized against MHD and other low frequency plasma instabilities by magnetic-well fields, but characterized by non-Maxwellian ion distributions; (b) near-Maxwellian plasmas, confined electrostatically (as in the tandem mirror) or in a field-reversed region within the mirror cell. Common to both situations are the questions of anomalous transport owing to high frequency instabilities in the non-maxwellian portions of the plasmas. This report will summarize the status of theory and of experimental data bearing on these questions, with particular reference to the high temperature regimes of interest for fusion power

  2. Transport barrier in Helical system

    International Nuclear Information System (INIS)

    Ida, Katsumi

    1998-01-01

    Experiments on the transport barrier in Helical plasmas are reviewed. There are two mechanisms of transport improvement, that results in the formation of the transport barrier. One is the improvement of neoclassical transport by reducing the ripple loss with radial electric field, which exist only in helical plasma. The other is the improvement of anomalous transport due to the suppression of fluctuations associated with a radial electric field shear both in tokamak and helical plasma. The formation of the transport barrier can be triggered by the radial electric field shear associated with the transition of the radial electric field (L/H transition or ion-electron root transition) or the peaked density or the optimization of magnetic field shear. The mechanisms of transport barrier formation are also discussed. (author). 60 refs

  3. Spin transport in spin filtering magnetic tunneling junctions.

    Science.gov (United States)

    Li, Yun; Lee, Eok Kyun

    2007-11-01

    Taking into account spin-orbit coupling and s-d interaction, we investigate spin transport properties of the magnetic tunneling junctions with spin filtering barrier using Landauer-Büttiker formalism implemented with the recursive algorithm to calculate the real-space Green function. We predict completely different bias dependence of negative tunnel magnetoresistance (TMR) between the systems composed of nonmagnetic electrode (NM)/ferromagnetic barrier (FB)/ferromagnet (FM) and NM/FB/FM/NM spin filtering tunnel junctions (SFTJs). Analyses of the results provide us possible ways of designing the systems which modulate the TMR in the negative magnetoresistance regime.

  4. Magnetic Signature Analysis & Validation System

    National Research Council Canada - National Science Library

    Vliet, Scott

    2001-01-01

    The Magnetic Signature Analysis and Validation (MAGSAV) System is a mobile platform that is used to measure, record, and analyze the perturbations to the earth's ambient magnetic field caused by object such as armored vehicles...

  5. Fractional diffusion models of transport in magnetically confined plasmas

    International Nuclear Information System (INIS)

    Castillo-Negrete, D. del; Carreras, B. A.; Lynch, V. E.

    2005-01-01

    Experimental and theoretical evidence suggests that transport in magnetically confined fusion plasmas deviates from the standard diffusion paradigm. Some examples include the confinement time scaling in L-mode plasmas, rapid pulse propagation phenomena, and inward transport in off-axis fueling experiments. The limitations of the diffusion paradigm can be traced back to the restrictive assumptions in which it is based. In particular, Fick's law, one of the cornerstones of diffusive transport, assumes that the fluxes only depend on local quantities, i. e. the spatial gradient of the field (s). another key issue is the Markovian assumption that neglects memory effects. Also, at a microscopic level, standard diffusion assumes and underlying Gaussian, uncorrelated stochastic process (i. e. a Brownian random walk) with well defined characteristic spatio-temporal scales. Motivated by the need to develop models of non-diffusive transport, we discuss here a class of transport models base on the use of fractional derivative operators. The models incorporates in a unified way non-Fickian transport, non-Markovian processes or memory effects, and non-diffusive scaling. At a microscopic level, the models describe an underlying stochastic process without characteristic spatio-temporal scales that generalizes the Brownian random walk. As a concrete case study to motivate and test the model, we consider transport of tracers in three-dimensional, pressure-gradient-driven turbulence. We show that in this system transport is non-diffusive and cannot be described in the context of the standard diffusion parading. In particular, the probability density function (pdf) of the radial displacements of tracers is strongly non-Gaussian with algebraic decaying tails, and the moments of the tracer displacements exhibit super-diffusive scaling. there is quantitative agreement between the turbulence transport calculations and the proposed fractional diffusion model. In particular, the model

  6. The beam transport system

    International Nuclear Information System (INIS)

    1986-01-01

    The first proton beams have been transported along the transfer beamline and the diagnostic components have thus been used and tested under real operating conditions. The various electronic systems have been linked to the control system and the equipment can now be operated from the control console. The performance of the diagnostic system for the transfer beamline is satisfactory. The beam diagnostic components for the high-energy beamlines up to the isotope production and neutron therapy vaults and the first experimental target rooms have been installed. The high-energy slits have been delivered. The scanner and harp electronics have been installed and linked to their respective components in the beamlines. The pneumatic acuator control electronics has been manufactured, installed and is operational; provision has been made for special control features of the equipment in the therapy beamline. The high-voltage bias supply for the Faraday cups has been implemented. The installation of the beam current measurement system is nearing completion although part of it is already operational. A coaxial relay multiplexer for the capacitive phase probe signals has been manufactured and installed. The diagnostic equipment for the beamlines to isotope production and neutron therapy is thus ready for operation. 4 figs

  7. Giant magnetoresistance and quantum transport in magnetic hybrid nanostructures

    International Nuclear Information System (INIS)

    Sanvito, S.

    2000-01-01

    Technological advances in device micro- and nano-fabrication over the past decade has enabled a variety of novel heterojunction device structures to be made. Among these, magnetic multilayers, superconductor/normal metal junctions and carbon nanotubes exhibit a rich variety of features, with the potential for future generations of electronic devices with improved sensitivity and higher packing density. The modeling of such structures in a flexible and accurate way, with a predictive capability is a formidable theoretical challenge. In this thesis I will present a very general numerical technique to compute transport properties of heterogeneous systems, which can be used together with accurate spd tight-binding Hamiltonians or simpler models. I will then apply this technique to several transport problems in the mesoscopic regime. Firstly I will review the material dependence of CPP GMR in perfect crystalline magnetic multilayers, analyze their conductance oscillations and discuss some preliminary results of magnetic tunneling junctions. In the contest of the conductance oscillations I will introduce a simple Kroenig-Penney model which gives a full understanding of the relevant periods involved in the oscillations. I will then present a simple model, which can be used to study disordered magnetic systems and the cross-over from ballistic to diffusive transport. This model explains recent experiments on CPP GMR, which cannot be understood within the usual Boltzmann transport framework. Then I will present results for superconducting/ normal metal and for superconducting/multilayer junctions. In the case of multilayers I will show that in both the ballistic and diffusive regimes the GMR is expected to vanish if a superconducting contact is added and go on to show why this is not the case in practice. Finally I will present features of ballistic transport in multiwall carbon nanotubes and show how the inter-tube interaction can, not only block some of the scattering

  8. Transportation System Concept of Operations

    Energy Technology Data Exchange (ETDEWEB)

    N. Slater-Thompson

    2006-08-16

    The Nuclear Waste Policy Act of 1982 (NWPA), as amended, authorized the DOE to develop and manage a Federal system for the disposal of SNF and HLW. OCRWM was created to manage acceptance and disposal of SNF and HLW in a manner that protects public health, safety, and the environment; enhances national and energy security; and merits public confidence. This responsibility includes managing the transportation of SNF and HLW from origin sites to the Repository for disposal. The Transportation System Concept of Operations is the core high-level OCRWM document written to describe the Transportation System integrated design and present the vision, mission, and goals for Transportation System operations. By defining the functions, processes, and critical interfaces of this system early in the system development phase, programmatic risks are minimized, system costs are contained, and system operations are better managed, safer, and more secure. This document also facilitates discussions and understanding among parties responsible for the design, development, and operation of the Transportation System. Such understanding is important for the timely development of system requirements and identification of system interfaces. Information provided in the Transportation System Concept of Operations includes: the functions and key components of the Transportation System; system component interactions; flows of information within the system; the general operating sequences; and the internal and external factors affecting transportation operations. The Transportation System Concept of Operations reflects OCRWM's overall waste management system policies and mission objectives, and as such provides a description of the preferred state of system operation. The description of general Transportation System operating functions in the Transportation System Concept of Operations is the first step in the OCRWM systems engineering process, establishing the starting point for the lower

  9. The magnet database system

    International Nuclear Information System (INIS)

    Baggett, P.; Delagi, N.; Leedy, R.; Marshall, W.; Robinson, S.L.; Tompkins, J.C.

    1991-01-01

    This paper describes the current status of MagCom, a central database of SSC magnet information that is available to all magnet scientists via network connections. The database has been designed to contain the specifications and measured values of important properties for major materials, plus configuration information (specifying which individual items were used in each cable, coil, and magnet) and the test results on completed magnets. These data will help magnet scientists to track and control the production process and to correlate the performance of magnets with the properties of their constituents

  10. Energy transport in cooling device by magnetic fluid

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Hiroshi, E-mail: hyamaguc@mail.doshisha.ac.jp [Department of Mechanical Engineering, Doshisha University, Kyo-tanabe, Kyoto 610-0321 (Japan); Iwamoto, Yuhiro [Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555 (Japan)

    2017-06-01

    Temperature sensitive magnetic fluid has a great potential with high performance heat transport ability as well as long distance energy (heat) transporting. In the present study experimental set-up was newly designed and constructed in order to measure basic heat transport characteristics under various magnetic field conditions. Angular dependence for the device (heat transfer section) was also taken into consideration for a sake of practical applications. The energy transfer characteristic (heat transport capability) in the magnetically-driven heat transport (cooling) device using the binary TSMF was fully investigated with the set-up. The obtained results indicate that boiling of the organic mixture (before the magnetic fluid itself reaching boiling point) effectively enhances the heat transfer as well as boosting the flow to circulate in the closed loop by itself. A long-distance heat transport of 5 m is experimentally confirmed, transferring the thermal energy of 35.8 W, even when the device (circulation loop) is horizontally placed. The highlighted results reveal that the proposed cooling device is innovative in a sense of transporting substantial amount of thermal energy (heat) as well as a long distance heat transport. The development of the magnetically-driven heat transport device has a great potential to be replaced for the conventional heat pipe in application of thermal engineering. - Highlights: • Temperature-sensitive magnetic fluid (TSMF) has a great heat transport ability. • Magnetically-driven heat transport device using binary TSMF is proposed. • The basic heat transport characteristics are investigated. • Boiling of the organic mixture effectively enhances the heat transfer. • A long-distance heat transport of 5 m is experimentally confirmed.

  11. Energy transport in cooling device by magnetic fluid

    International Nuclear Information System (INIS)

    Yamaguchi, Hiroshi; Iwamoto, Yuhiro

    2017-01-01

    Temperature sensitive magnetic fluid has a great potential with high performance heat transport ability as well as long distance energy (heat) transporting. In the present study experimental set-up was newly designed and constructed in order to measure basic heat transport characteristics under various magnetic field conditions. Angular dependence for the device (heat transfer section) was also taken into consideration for a sake of practical applications. The energy transfer characteristic (heat transport capability) in the magnetically-driven heat transport (cooling) device using the binary TSMF was fully investigated with the set-up. The obtained results indicate that boiling of the organic mixture (before the magnetic fluid itself reaching boiling point) effectively enhances the heat transfer as well as boosting the flow to circulate in the closed loop by itself. A long-distance heat transport of 5 m is experimentally confirmed, transferring the thermal energy of 35.8 W, even when the device (circulation loop) is horizontally placed. The highlighted results reveal that the proposed cooling device is innovative in a sense of transporting substantial amount of thermal energy (heat) as well as a long distance heat transport. The development of the magnetically-driven heat transport device has a great potential to be replaced for the conventional heat pipe in application of thermal engineering. - Highlights: • Temperature-sensitive magnetic fluid (TSMF) has a great heat transport ability. • Magnetically-driven heat transport device using binary TSMF is proposed. • The basic heat transport characteristics are investigated. • Boiling of the organic mixture effectively enhances the heat transfer. • A long-distance heat transport of 5 m is experimentally confirmed.

  12. High-Energy Beam Transport system

    International Nuclear Information System (INIS)

    Melson, K.E.; Farrell, J.A.; Liska, D.J.

    1979-01-01

    The High-Energy Beam Transport (HEBT) system for the Fusion Materials Irradiation Test (FMIT) Facility is to be installed at the Hanford Engineering Development Laboratory (HEDL) at Richland, Washington. The linear accelerator must transport a large emittance, high-current, high-power, continuous-duty deuteron beam with a large energy spread either to a lithium target or a beam stop. A periodic quadrupole and bending-magnet system provides the beam transport and focusing on target with small beam aberrations. A special rf cavity distributes the energy in the beam so that the Bragg Peak is distributed within the lithium target. Operation of the rf control system, the Energy Dispersion Cavity (EDC), and the beam transport magnets is tested on the beam stop during accelerator turn-on. Characterizing the beam will require extensions of beam diagnostic techniques and noninterceptive sensors. Provisions are being made in the facility for suspending the transport system from overhead supports using a cluster system to simplify maintenance and alignment techniques

  13. Canadian pipeline transportation system : transportation assessment

    International Nuclear Information System (INIS)

    2009-07-01

    In addition to regulating the construction and operation of 70,000 km of oil and natural gas pipelines in Canada, the National Energy Board (NEB) regulates the trade of natural gas, oil and natural gas liquids. This report provided an assessment of the Canadian hydrocarbon transportation system in relation to its ability to provide a robust energy infrastructure. Data was collected from NEB-regulated pipeline companies and a range of publicly available sources to determine if adequate pipeline capacity is in place to transport products to consumers. The NEB also used throughput and capacity information received from pipeline operators as well as members of the investment community. The study examined price differentials compared with firm service tolls for transportation paths, as well as capacity utilization on pipelines and the degree of apportionment on major oil pipelines. This review indicated that in general, the Canadian pipeline transportation system continues to work effectively, with adequate pipeline capacity in place to move products to consumers who need them. 9 tabs., 30 figs., 3 appendices.

  14. Canadian hydrocarbon transportation system : transportation assessment

    International Nuclear Information System (INIS)

    2006-06-01

    This document provided an assessment of the Canadian hydrocarbon transportation system. In addition to regulating the construction and operation of Canada's 45,000 km of pipeline that cross international and provincial borders, Canada's National Energy Board (NEB) regulates the trade of natural gas, oil and natural gas liquids. The ability of pipelines to delivery this energy is critical to the country's economic prosperity. The pipeline system includes large-diameter, cross-country, high-pressure natural gas pipelines, low-pressure crude oil and oil products pipelines and small-diameter pipelines. In order to assess the hydrocarbon transportation system, staff at the NEB collected data from pipeline companies and a range of publicly available sources. The Board also held discussions with members of the investment community regarding capital markets and emerging issues. The assessment focused largely on evaluating whether Canadians benefit from an efficient energy infrastructure and markets. The safety and environmental integrity of the pipeline system was also evaluated. The current adequacy of pipeline capacity was assessed based on price differentials compared with firm service tolls for major transportation paths; capacity utilization on pipelines; and, the degree of apportionment on major oil pipelines. The NEB concluded that the Canadian hydrocarbon transportation system is working effectively, with an adequate capacity in place on existing natural gas pipelines, but with a tight capacity on oil pipelines. It was noted that shippers continue to indicate that they are reasonably satisfied with the services provided by pipeline companies and that the NEB-regulated pipeline companies are financially stable. 14 refs, 11 tabs., 28 figs., 4 appendices

  15. Third-order TRANSPORT: A computer program for designing charged particle beam transport systems

    International Nuclear Information System (INIS)

    Carey, D.C.; Brown, K.L.; Rothacker, F.

    1995-05-01

    TRANSPORT has been in existence in various evolutionary versions since 1963. The present version of TRANSPORT is a first-, second-, and third-order matrix multiplication computer program intended for the design of static-magnetic beam transport systems. This report discusses the following topics on TRANSPORT: Mathematical formulation of TRANSPORT; input format for TRANSPORT; summaries of TRANSPORT elements; preliminary specifications; description of the beam; physical elements; other transformations; assembling beam lines; operations; variation of parameters for fitting; and available constraints -- the FIT command

  16. Energy transport in cooling device by magnetic fluid

    Science.gov (United States)

    Yamaguchi, Hiroshi; Iwamoto, Yuhiro

    2017-06-01

    Temperature sensitive magnetic fluid has a great potential with high performance heat transport ability as well as long distance energy (heat) transporting. In the present study experimental set-up was newly designed and constructed in order to measure basic heat transport characteristics under various magnetic field conditions. Angular dependence for the device (heat transfer section) was also taken into consideration for a sake of practical applications. The energy transfer characteristic (heat transport capability) in the magnetically-driven heat transport (cooling) device using the binary TSMF was fully investigated with the set-up. The obtained results indicate that boiling of the organic mixture (before the magnetic fluid itself reaching boiling point) effectively enhances the heat transfer as well as boosting the flow to circulate in the closed loop by itself. A long-distance heat transport of 5 m is experimentally confirmed, transferring the thermal energy of 35.8 W, even when the device (circulation loop) is horizontally placed. The highlighted results reveal that the proposed cooling device is innovative in a sense of transporting substantial amount of thermal energy (heat) as well as a long distance heat transport. The development of the magnetically-driven heat transport device has a great potential to be replaced for the conventional heat pipe in application of thermal engineering.

  17. Transport properties of electrons in fractal magnetic-barrier structures

    Science.gov (United States)

    Sun, Lifeng; Fang, Chao; Guo, Yong

    2010-09-01

    Quantum transport properties in fractal magnetically modulated structures are studied by the transfer-matrix method. It is found that the transmission spectra depend sensitively not only on the incident energy and the direction of the wave vector but also on the stage of the fractal structures. Resonance splitting, enhancement, and position shift of the resonance peaks under different magnetic modulation are observed at four different fractal stages, and the relationship between the conductance in the fractal structure and magnetic modulation is also revealed. The results indicate the spectra of the transmission can be considered as fingerprints for the fractal structures, which show the subtle correspondence between magnetic structures and transport behaviors.

  18. Microstripes for transport and separation of magnetic particles

    DEFF Research Database (Denmark)

    Donolato, Marco; Dalslet, Bjarke Thomas; Hansen, Mikkel Fougt

    2012-01-01

    We present a simple technique for creating an on-chip magnetic particle conveyor based on exchange-biased permalloy microstripes. The particle transportation relies on an array of stripes with a spacing smaller than their width in conjunction with a periodic sequence of four different externally...... applied magnetic fields. We demonstrate the controlled transportation of a large population of particles over several millimeters of distance as well as the spatial separation of two populations of magnetic particles with different magnetophoretic mobilities. The technique can be used for the controlled...... selective manipulation and separation of magnetically labelled species. (C) 2012 American Institute of Physics....

  19. Novel Approach to Linear Accelerator Superconducting Magnet System

    International Nuclear Information System (INIS)

    Kashikhin, Vladimir

    2011-01-01

    Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.

  20. Quantum transport in coupled resonators enclosed synthetic magnetic flux

    International Nuclear Information System (INIS)

    Jin, L.

    2016-01-01

    Quantum transport properties are instrumental to understanding quantum coherent transport processes. Potential applications of quantum transport are widespread, in areas ranging from quantum information science to quantum engineering, and not restricted to quantum state transfer, control and manipulation. Here, we study light transport in a ring array of coupled resonators enclosed synthetic magnetic flux. The ring configuration, with an arbitrary number of resonators embedded, forms a two-arm Aharonov–Bohm interferometer. The influence of magnetic flux on light transport is investigated. Tuning the magnetic flux can lead to resonant transmission, while half-integer magnetic flux quantum leads to completely destructive interference and transmission zeros in an interferometer with two equal arms. -- Highlights: •The light transport is investigated through ring array of coupled resonators enclosed synthetic magnetic field. •Aharonov–Bohm ring interferometer of arbitrary configuration is investigated. •The half-integer magnetic flux quantum leads to destructive interference and transmission zeros for two-arm at equal length. •Complete transmission is available via tuning synthetic magnetic flux.

  1. Classification of Magnetic Nanoparticle Systems

    DEFF Research Database (Denmark)

    Bogren, Sara; Fornara, Andrea; Ludwig, Frank

    2015-01-01

    and the size parameters are determined from electron microscopy and dynamic light scattering. Using these methods, we also show that the nanocrystal size and particle morphology determines the dynamic magnetic properties for both single- and multi-core particles. The presented results are obtained from...... the four year EU NMP FP7 project, NanoMag, which is focused on standardization of analysis methods for magnetic nanoparticles.......This study presents classification of different magnetic single- and multi-core particle systems using their measured dynamic magnetic properties together with their nanocrystal and particle sizes. The dynamic magnetic properties are measured with AC (dynamical) susceptometry and magnetorelaxometry...

  2. Advanced public transportation systems benefits

    Science.gov (United States)

    1996-03-01

    Benefits and cost savings for various Advanced Public Transportation Systems are outlined here. Operational efficiencies are given for Transit Management Systems in different locales, as well as compliant resolution and safety. Electronic Fare Paymen...

  3. Intelligent Transportation Systems : critical standards

    Science.gov (United States)

    1999-06-01

    Intelligent Transportation Systems (ITS) standards are industry-consensus standards that provide the details about how different systems interconnect and communicate information to deliver the ITS user services described in the National ITS Architect...

  4. Coupled electron/photon transport in static external magnetic fields

    International Nuclear Information System (INIS)

    Halbleib, J.A. Sr.; Vandevender, W.H.

    A model is presented which describes coupled electron/photon transport in the presence of static magnetic fields of arbitrary spatial dependence. The method combines state-of-the-art condensed-history electron collisional Monte Carlo and single-scattering photon Monte Carlo, including electron energy-loss straggling and the production and transport of all generations of secondaries, with numerical field integration via the best available variable-step-size Runge-Kutta-Fehlberg or variable-order/variable-step-size Adams PECE differential equation solvers. A three-dimensional cartesian system is employed in the description of particle trajectories. Although the present model is limited to multilayer material configurations, extension to more complex material geometries should not be difficult. Among the more important options are (1) a feature which permits the neglect of field effects in regions where transport is collision dominated and (2) a method for describing the transport in variable-density media where electron energies and material densities are sufficiently low that the density effect on electronic stopping powers may be neglected. (U.S.)

  5. Superconducting magnet suspensions in high speed ground transport

    Energy Technology Data Exchange (ETDEWEB)

    Alston, I A

    1973-08-01

    A technical and economic definition of high speed ground transport systems using magnetic suspensions is given. The full range of common superconducting suspensions and of propulsions are covered with designs produced for speeds ranging from 100 m/s (225 miles/hr) to 250 m/s (560 mile/hr). Technical descriptions of the vehicles, their suspensions, propulsions and tracks are given in some detail and operating costs are presented for all the systems together with details of the breakdown of costs and the capital costs involved. The design assumptions, the costing procedure and a cost sensitivity study are presented. It is concluded that the systems are technically feasible; that they are suited to existing duorail track for low speed running and that, in these circumstances, they would be economically viable over many routes.

  6. Measurement of magnetic fluctuation induced energy transport

    International Nuclear Information System (INIS)

    Fiksel, G.; Prager, S.C.; Shen, W.; Stoneking, M.

    1993-11-01

    The local electron energy flux produced by magnetic fluctuations has been measured directly in the MST reversed field pinch (over the radial range r/a > 0.75). The flux, produced by electrons traveling parallel to a fluctuating magnetic field, is obtained from correlation between the fluctuations in the parallel heat flux and the radial magnetic field. The fluctuation induced flux is large (100 kW/cm 2 ) in the ''core'' (r/a 2 ) in the edge

  7. The effects of magnetic perturbations on plasma transport or is magnetic turbulence important in tokamaks?

    International Nuclear Information System (INIS)

    Wootton, A.J.

    1993-01-01

    A test particle model is verified and then used to interpret estimates of fast electron diffusivities in terms of magnetic fluctuation levels. The implied fluctuation levels are themselves interpreted with another verified model to predict electron thermal diffusivities. If the fast electron diffusivities represent local values, then the implied associated thermal transport is too small to explain experimental values. That is, magnetic fluctuations are not important. However, if the fast electron diffusivities represent effective values across mixed good (i.e. with no magnetic fluctuations) and bad (with magnetic fluctuations) surfaces then the implied magnetic fluctuation levels can influence electron thermal transport. (author)

  8. Air transport system

    CERN Document Server

    Schmitt, Dieter

    2016-01-01

    The book addresses all major aspects to be considered for the design and operation of aircrafts within the entire transportation chain. It provides the basic information about the legal environment, which defines the basic requirements for aircraft design and aircraft operation. The interactions between  airport, air traffic management and the airlines are described. The market forecast methods and the aircraft development process are explained to understand the very complex and risky business of an aircraft manufacturer. The principles of flight physics as basis for aircraft design are presented and linked to the operational and legal aspects of air transport including all environmental impacts. The book is written for graduate students as well as for engineers and experts, who are working in aerospace industry, at airports or in the domain of transport and logistics.

  9. LHC magnet quench protection system

    Science.gov (United States)

    Coull, L.; Hagedorn, D.; Remondino, V.; Rodriguez-Mateos, F.

    1994-07-01

    The quench protection system for the superconducting magnets of the CERN Large Hadron Collider (LHC) is described. The system is based on the so called 'cold diode' concept. In a group of series connected magnets if one magnet quenches then the magnetic energy of all the magnets will be dissipated in the quenched magnet so destroying it. This is avoided by by-passing the quenched magnet and then rapidly de-exciting the unquenched magnets. For the LHC machine it is foreseen to use silicon diodes situated inside the cryostat as by-pass elements - so called 'cold diodes'. The diodes are exposed to some 50 kGray of radiation during a 10 year operation life-time. The high energy density of the LHC magnets (500 kJ/m) coupled with the relatively slow propagation speed of a 'natural' quench (10 to 20 m/s) can lead to excessive heating of the zone where the quench started and to high internal voltages. It is therefore necessary to detect quickly the incipient quench and fire strip heaters which spread the quench out more quickly over a large volume of the magnet. After a quench the magnet chain must be de-excited rapidly to avoid spreading the quench to other magnets and over-heating the by-pass diode. This is done by switching high-power energy-dump resistors in series with the magnets. The LHC main ring magnet will be divided into 16 electrically separated units which has important advantages.

  10. LHC magnet quench protection system

    International Nuclear Information System (INIS)

    Coull, L.; Hagedorn, D.; Remondino, V.; Rodriguez-Mateos, F.

    1994-01-01

    The quench protection system for the superconducting magnets of the CERN Large Hadron Collider (LHC) is described. The system is based on the so called ''cold diode'' concept. In a group of series connected magnets if one magnet quenches then the magnetic energy of all the magnets will be dissipated in the quenched magnet so destroying it. This is avoided by by-passing the quenched magnet and then rapidly de-exciting the unquenched magnets. For the LHC machine it is foreseen to use silicon diodes situated inside the cryostat as by-pass elements--so called ''cold diodes''. The diodes are exposed to some 50 kGray of radiation during a 10 year operation life-time. The high energy density of the LHC magnets (500 kJ/m) coupled with the relatively slow propagation speed of a ''natural'' quench (10 to 20 m/s) can lead to excessive heating of the zone where the quench started and to high internal voltages. It is therefore necessary to detect quickly the incipient quench and fire strip heaters which spread the quench out more quickly over a large volume of the magnet. After a quench the magnet chain must be de-excited rapidly to avoid spreading the quench to other magnets and over-heating the by-pass diode. This is done by switching high-power energy-dump resistors in series with the magnets. The LHC main ring magnet will be divided into 16 electrically separated units which has important advantages

  11. Parallel heat transport in integrable and chaotic magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Castillo-Negrete, D. del; Chacon, L. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8071 (United States)

    2012-05-15

    The study of transport in magnetized plasmas is a problem of fundamental interest in controlled fusion, space plasmas, and astrophysics research. Three issues make this problem particularly challenging: (i) The extreme anisotropy between the parallel (i.e., along the magnetic field), {chi}{sub ||} , and the perpendicular, {chi}{sub Up-Tack }, conductivities ({chi}{sub ||} /{chi}{sub Up-Tack} may exceed 10{sup 10} in fusion plasmas); (ii) Nonlocal parallel transport in the limit of small collisionality; and (iii) Magnetic field lines chaos which in general complicates (and may preclude) the construction of magnetic field line coordinates. Motivated by these issues, we present a Lagrangian Green's function method to solve the local and non-local parallel transport equation applicable to integrable and chaotic magnetic fields in arbitrary geometry. The method avoids by construction the numerical pollution issues of grid-based algorithms. The potential of the approach is demonstrated with nontrivial applications to integrable (magnetic island), weakly chaotic (Devil's staircase), and fully chaotic magnetic field configurations. For the latter, numerical solutions of the parallel heat transport equation show that the effective radial transport, with local and non-local parallel closures, is non-diffusive, thus casting doubts on the applicability of quasilinear diffusion descriptions. General conditions for the existence of non-diffusive, multivalued flux-gradient relations in the temperature evolution are derived.

  12. Transport and spin effects in homogeneous magnetic superlattice

    International Nuclear Information System (INIS)

    Cardoso, J.L.; Pereyra, P.; Anzaldo-Meneses, A.

    2000-09-01

    Homogeneous semiconductors under spacially periodic external magnetic fields exhibit spin-band splitting and displacements, more clearly defined than in diluted magnetic semiconductor superlattices. We study the influence of the geometrical parameters and the spin-field interaction on the electronic transport properties. We show that by varying the external magnetic field, one can easily block the transmission of either the spin-up or the spin-down electrons. (author)

  13. Anomalous transport phenomena in Fermi liquids with strong magnetic fluctuations

    International Nuclear Information System (INIS)

    Kontani, Hiroshi

    2008-01-01

    In this paper, we present recent developments in the theory of transport phenomena based on the Fermi liquid theory. In conventional metals, various transport coefficients are scaled according to the quasiparticles relaxation time, τ, which implies that the relaxation time approximation (RTA) holds well. However, such a simple scaling does not hold in many strongly correlated electron systems. The most famous example would be high-T c superconductors (HTSCs), where almost all the transport coefficients exhibit a significant deviation from the RTA results. This issue has been one of the most significant unresolved problems in HTSCs for a long time. Similar anomalous transport phenomena have been observed in metals near their antiferromagnetic (AF) quantum critical point (QCP). The main goal of this study is to demonstrate whether the anomalous transport phenomena in HTSC is evidence of a non-Fermi liquid ground state, or just RTA violation in strongly correlated Fermi liquids. Another goal is to establish a unified theory of anomalous transport phenomena in metals with strong magnetic fluctuations. For these purposes, we develop a method for calculating various transport coefficients beyond the RTA by employing field theoretical techniques. In a Fermi liquid, an excited quasiparticle induces other excited quasiparticles by collision, and current due to these excitations is called a current vertex correction (CVC). Landau noticed the existence of CVC first, which is indispensable for calculating transport coefficients in accord with the conservation laws. Here, we develop a transport theory involving resistivity and the Hall coefficient on the basis of the microscopic Fermi liquid theory, by considering the CVC. In nearly AF Fermi liquids, we find that the strong backward scattering due to AF fluctuations induces the CVC with prominent momentum dependence. This feature of the CVC can account for the significant enhancement in the Hall coefficient, magnetoresistance

  14. Tribology of magnetic storage systems

    Science.gov (United States)

    Bhushan, Bharat

    1992-01-01

    The construction and the materials used in different magnetic storage devices are defined. The theories of friction and adhesion, interface temperatures, wear, and solid-liquid lubrication relevant to magnetic storage systems are presented. Experimental data are presented wherever possible to support the relevant theories advanced.

  15. Oxygen transport enhancement by functionalized magnetic nanoparticles (FMP) in bioprocesses

    Science.gov (United States)

    Ataide, Filipe Andre Prata

    The enhancement of fluid properties, namely thermal conductivity and mass diffusivity for a wide range of applications, through the use of nanosized particles' suspensions has been gathering increasing interest in the scientific community. In previous studies, Olle et al. (2006) showed an enhancement in oxygen absorption to aqueous solutions of up to 6-fold through the use of functionalized nanosized magnetic particles with oleic acid coating. Krishnamurthy et al. (2006) showed a remarkable 26-fold enhancement in dye diffusion in water. These two publications are landmarks in mass transfer enhancement in chemical systems through the use of nanoparticles. The central goal of this Ph.D. thesis was to develop functionalized magnetic nanoparticles to enhance oxygen transport in bioprocesses. The experimental protocol for magnetic nanoparticles synthesis and purification adopted in this thesis is a modification of that reported by Olle et al. (2006). This is facilitated by employing twice the quantity of ammonia, added at a slower rate, and by filtering the final nanoparticle solution in a cross-flow filtration modulus against 55 volumes of distilled water. This modification in the protocol resulted in improved magnetic nanoparticles with measurably higher mass transfer enhancement. Magnetic nanoparticles with oleic acid and Hitenol-BC coating were screened for oxygen transfer enhancement, since these particles are relatively inexpensive and easy to synthesize. A glass 0.5-liter reactor was custom manufactured specifically for oxygen transport studies in magnetic nanoparticles suspensions. The reactor geometry, baffles and Rushton impeller are of standard dimensions. Mass transfer tests were conducted through the use of the sulphite oxidation method, applying iodometric back-titration. A 3-factor central composite circumscribed design (CCD) was adopted for design of experiments in order to generate sufficiently informative data to model the effect of magnetic

  16. Topology optimized permanent magnet systems

    Science.gov (United States)

    Bjørk, R.; Bahl, C. R. H.; Insinga, A. R.

    2017-09-01

    Topology optimization of permanent magnet systems consisting of permanent magnets, high permeability iron and air is presented. An implementation of topology optimization for magnetostatics is discussed and three examples are considered. The Halbach cylinder is topology optimized with iron and an increase of 15% in magnetic efficiency is shown. A topology optimized structure to concentrate a homogeneous field is shown to increase the magnitude of the field by 111%. Finally, a permanent magnet with alternating high and low field regions is topology optimized and a Λcool figure of merit of 0.472 is reached, which is an increase of 100% compared to a previous optimized design.

  17. Topology optimized permanent magnet systems

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian; Insinga, Andrea Roberto

    2017-01-01

    Topology optimization of permanent magnet systems consisting of permanent magnets, high permeability iron and air is presented. An implementation of topology optimization for magnetostatics is discussed and three examples are considered. The Halbach cylinder is topology optimized with iron...... and an increase of 15% in magnetic efficiency is shown. A topology optimized structure to concentrate a homogeneous field is shown to increase the magnitude of the field by 111%. Finally, a permanent magnet with alternating high and low field regions is topology optimized and a ΛcoolΛcool figure of merit of 0...

  18. Electron transport in magnetic multilayers: effect of disorder

    Czech Academy of Sciences Publication Activity Database

    Drchal, Václav; Kudrnovský, Josef; Bruno, P.; Dederichs, P. H.; Turek, Ilja; Weinberger, P.

    2002-01-01

    Roč. 65, - (2002), s. 214414-1-214414-8 ISSN 0163-1829 R&D Projects: GA MŠk OC P5.30; GA ČR GA202/00/0122; GA AV ČR IAA1010829; GA AV ČR IBS2041105 Institutional research plan: CEZ:AV0Z1010914 Keywords : electron transport * magnetic multilayers * ballistic transport * diffusive transport * disorder Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.327, year: 2002

  19. Charge and Spin Transport in Spin-orbit Coupled and Topological Systems

    KAUST Repository

    Ndiaye, Papa Birame

    2017-01-01

    for next-generation technology, three classes of systems that possibly enhance the spin and charge transport efficiency: (i)- topological insulators, (ii)- spin-orbit coupled magnonic systems, (iii)- topological magnetic textures (skyrmions and 3Q magnetic

  20. Plasma transport in stochastic magnetic fields. I. General considerations and test particle transport

    International Nuclear Information System (INIS)

    Krommes, J.A.; Kleva, R.G.; Oberman, C.

    1978-05-01

    A systematic theory is developed for the computation of electron transport in stochastic magnetic fields. Small scale magnetic perturbations arising, for example, from finite-β micro-instabilities are assumed to destroy the flux surfaces of a standard tokamak equilibrium. Because the magnetic lines then wander in a volume, electron radial flux is enhanced due to the rapid particle transport along as well as across the lines. By treating the magnetic lines as random variables, it is possible to develop a kinetic equation for the electron distribution function. This is solved approximately to yield the diffusion coefficient

  1. Plasma transport in stochastic magnetic fields. I. General considerations and test particle transport

    Energy Technology Data Exchange (ETDEWEB)

    Krommes, J.A.; Kleva, R.G.; Oberman, C.

    1978-05-01

    A systematic theory is developed for the computation of electron transport in stochastic magnetic fields. Small scale magnetic perturbations arising, for example, from finite-..beta.. micro-instabilities are assumed to destroy the flux surfaces of a standard tokamak equilibrium. Because the magnetic lines then wander in a volume, electron radial flux is enhanced due to the rapid particle transport along as well as across the lines. By treating the magnetic lines as random variables, it is possible to develop a kinetic equation for the electron distribution function. This is solved approximately to yield the diffusion coefficient.

  2. Transport of plasma across a braided magnetic field

    International Nuclear Information System (INIS)

    Stix, T.H.

    1976-10-01

    Transport rates are calculated for a plasma immersed in a region through which magnetic lines of force meander in a stochastic fashion and in which the magnetic surfaces are destroyed. Such a magnetic condition, termed magnetic braiding, may be brought about by asymmetric magnetic perturbations, perhaps quite weak, which typically produce overlap of two sets of magnetic islands. Plasma transport is calculated for this environment, using both a fluid and a kinetic drift model. The latter gives an appreciably higher rate, namely, a fast-particle diffusion coefficient equal to ( 1 / 2 )D/sub M/ [absolute value of v/sub ''/], where D/sub M/ is the coefficient of spatial diffusion for the magnetic lines of force. Correction terms, due to polarization-associated E/sub ''/ fields, are small unless components of the braiding field resonate with ion-acoustic or drift waves. Insertion of a Bhatnager--Gross--Krook collision term shows the diffusion rate is unaffected by weak collisions. Diffusion due to magnetic braiding is of interest for tokamaks, particularly with respect to enhanced electron heat transport, enhanced current penetration, plasma disruption, and internal sawtooth oscillations

  3. Bending magnets for the CBA beam-transport line

    International Nuclear Information System (INIS)

    Thern, R.E.

    1983-01-01

    The beam-transport line from the AGS to CBA requires 68 large bending magnets, consisting of pure dipoles and two types of combined function gradient magnets. All three types were designed with magnetic-field calculation program POISSON, using the same exterior dimensions and coil package. The design goal of +-1% momentum acceptance for the transport line required a wide horizontal aperture, with a much-smaller vertical aperture for economy. Two prototypes of one gradient magnet were built, and a facility constructed to measure them and the later production magnets. Measurements were done using both a long coil and a point coil (Rawson-Lush gaussmeter). Preliminary results show δB/B - 3 , δG/G - 2 , and δB 2 /B - 4 cm - 2 over the beam aperture. Due to end effects, the actual gradient differs from the design gradient by 1%, which has been compensated for in the beam-line design

  4. Thermal transport in fractal systems

    DEFF Research Database (Denmark)

    Kjems, Jørgen

    1992-01-01

    Recent experiments on the thermal transport in systems with partial fractal geometry, silica aerogels, are reviewed. The individual contributions from phonons, fractons and particle modes, respectively, have been identified and can be described by quantitative models consistent with heat capacity...

  5. Self-Organized Transport System

    Science.gov (United States)

    2009-09-28

    This report presents the findings of the simulation model for a self-organized transport system where traffic lights communicate with neighboring traffic lights and make decisions locally to adapt to traffic conditions in real time. The model is insp...

  6. Control of Internal Transport Barriers in Magnetically Confined Fusion Plasmas

    Science.gov (United States)

    Panta, Soma; Newman, David; Sanchez, Raul; Terry, Paul

    2016-10-01

    In magnetic confinement fusion devices the best performance often involves some sort of transport barriers to reduce the energy and particle flow from core to edge. Those barriers create gradients in the temperature and density profiles. If gradients in the profiles are too steep that can lead to instabilities and the system collapses. Control of these barriers is therefore an important challenge for fusion devices (burning plasmas). In this work we focus on the dynamics of internal transport barriers. Using a simple 7 field transport model, extensively used for barrier dynamics and control studies, we explore the use of RF heating to control the local gradients and therefore the growth rates and shearing rates for barrier initiation and control in self-heated fusion plasmas. Ion channel barriers can be formed in self-heated plasmas with some NBI heating but electron channel barriers are very sensitive. They can be formed in self-heated plasmas with additional auxiliary heating i.e. NBI and radio-frequency(RF). Using RF heating on both electrons and ions at proper locations, electron channel barriers along with ion channel barriers can be formed and removed demonstrating a control technique. Investigating the role of pellet injection in controlling the barriers is our next goal. Work supported by DOE Grant DE-FG02-04ER54741.

  7. Transport processes in magnetically confined plasmas in the nonlinear regime.

    Science.gov (United States)

    Sonnino, Giorgio

    2006-06-01

    A field theory approach to transport phenomena in magnetically confined plasmas is presented. The thermodynamic field theory (TFT), previously developed for treating the generic thermodynamic system out of equilibrium, is applied to plasmas physics. Transport phenomena are treated here as the effect of the field linking the thermodynamic forces with their conjugate flows combined with statistical mechanics. In particular, the Classical and the Pfirsch-Schluter regimes are analyzed by solving the thermodynamic field equations of the TFT in the weak-field approximation. We found that, the TFT does not correct the expressions of the ionic heat fluxes evaluated by the neoclassical theory in these two regimes. On the other hand, the fluxes of matter and electronic energy (heat flow) is further enhanced in the nonlinear Classical and Pfirsch-Schluter regimes. These results seem to be in line with the experimental observations. The complete set of the electronic and ionic transport equations in the nonlinear Banana regime, is also reported. A paper showing the comparison between our theoretic results and the experimental observations in the JET machine is currently in preparation.

  8. Transport in a magnetic field modulated graphene superlattice.

    Science.gov (United States)

    Li, Yu-Xian

    2010-01-13

    Using the transfer matrix method, we study the transport properties through a magnetic field modulated graphene superlattice. It is found that the electrostatic barrier, the magnetic vector potential, and the number of wells in a superlattice modify the transmission remarkably. The angular dependent transmission is blocked by the magnetic vector potential because of the appearance of the evanescent states at certain incident angles, and the region of Klein tunneling shifts to the left. The angularly averaged conductivities exhibit oscillatory behavior. The magnitude and period of oscillation depend sensitively on the height of the electrostatic barrier, the number of wells, and the strength of the modulated magnetic field.

  9. Transport of runaway and thermal electrons due to magnetic microturbulence

    International Nuclear Information System (INIS)

    Mynick, H.E.; Strachan, J.D.

    1981-01-01

    The ratio of the runaway electron confinement to thermal electron energy confinement is derived for tokamaks where both processes are determined by free streaming along stochastic magnetic field lines. The runaway electron confinement is enhanced at high runaway electron energies due to phase averaging over the magnetic perturbations when the runaway electron drift surfaces are displaced from the magnetic surfaces. Comparison with experimental data from LT-3, Ormak, PLT, ST, and TM-3 indicates that magnetic stochasticity may explain the relative transport rates of runaways and thermal electron energy

  10. Non-linear spin transport in magnetic semiconductor superlattices

    International Nuclear Information System (INIS)

    Bejar, Manuel; Sanchez, David; Platero, Gloria; MacDonald, A.H.

    2004-01-01

    The electronic spin dynamics in DC-biased n-doped II-VI semiconductor multiquantum wells doped with magnetic impurities is presented. Under certain range of electronic doping, conventional semiconductor superlattices present self-sustained oscillations. Magnetically doped wells (Mn) present large spin splittings due to the exchange interaction. The interplay between non-linear interwell transport, the electron-electron interaction and the exchange between electrons and the magnetic impurities produces interesting time-dependent features in the spin polarization current tuned by an external magnetic field

  11. Inactive trials of transport systems

    International Nuclear Information System (INIS)

    Haberlin, M.M.; Hardy, A.R.

    1985-06-01

    The design and manufacture of a mock-up of a crate handling and size reduction (CHSR) facility, an experimental programme on the evaluation of a commercial air-transporter, and the selection, manufacture and commissioning trials of an integrated conveyor system for transporting crated waste into and within the mock-up facility, are considered. The mock-up facility was used for the test programme on the air-transporter and conveyor system. The air-transporter was considered suitable for transporting waste on the metal floor in the main dismantling area of the CHSR facility because it can tolerate asymmetric loading, the exhaust air flow liberated from the air-pads is low and it has excellent manoeuvrability. Commissioning trials were carried out on a commercial conveyor system consisting of unpowered rollers in the reception area, a powered slatted conveyor in the air-lock and an unpowered roller table placed on the air-transporter in the working area. It was demonstrated that a large asymmetrically loaded wooden crate can be transported into and within the facility by this method. Further design and experimental work necessary before the system can be used for remote operation is discussed. (author)

  12. Magnetically Levitated and Guided Systems

    Directory of Open Access Journals (Sweden)

    Florian Puci

    2017-05-01

    Full Text Available The paper describes the fundamentals of magnetic levitation technology. A general background of the magnetic levitation is given in this article, including applications of this technology, several comparisons with other types of technologies, the real stage of its development, etc. Further in the paper, the two main types of magnetically levitated systems are compared within their subgroups, on characteristics and specifications basis. A comparison between the AC and DC power supplies for these systems, including the pros and cons of each type, is also provided in the paper.

  13. Radial transport with perturbed magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Hazeltine, R. D. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-05-15

    It is pointed out that the viscosity coefficient describing radial transport of toroidal angular momentum is proportional to the second power of the gyro-radius—like the corresponding coefficients for particle and heat transport—regardless of any geometrical symmetry. The observation is widely appreciated, but worth emphasizing because some literature gives the misleading impression that asymmetry can allow radial moment transport in first-order.

  14. Radial transport with perturbed magnetic field

    International Nuclear Information System (INIS)

    Hazeltine, R. D.

    2015-01-01

    It is pointed out that the viscosity coefficient describing radial transport of toroidal angular momentum is proportional to the second power of the gyro-radius—like the corresponding coefficients for particle and heat transport—regardless of any geometrical symmetry. The observation is widely appreciated, but worth emphasizing because some literature gives the misleading impression that asymmetry can allow radial moment transport in first-order

  15. Field flattening in superconducting beam transport magnets

    International Nuclear Information System (INIS)

    Morgan, G.H.

    1994-01-01

    Dipoles in which the beam traverses the midplane well away from tie magnet axis may benefit from flattening of the vertical field on the midplane. A procedure is described for doing so, making use of Chebyshev polynomials. In the case of the large aperture ''DX'' magnets located immediately on each side of the six intersection regions of the Relativistic Heavy Ion Powder (RHIC), a comparison is made of the field of coils optimized in this way and of coils optimized in the more common way by minimizing the leading coefficients of the Fourier expansion about the magnet axis. The comparison is of the integrated Fourier coefficients of the field expanded locally along the beam trajectory

  16. ANALYISIS OF TRANSPORTATION SYSTEMS AND TRANSPORTATION POLICIES IN TURKEY

    Directory of Open Access Journals (Sweden)

    Ali Payıdar AKGÜNGÖR

    2004-03-01

    Full Text Available Transportation systems have to be considered and analysed as a whole while transportation demand, becoming as a natural outcome of socioeconomic and socio-cultural structure, is being evaluated. It is desired that transportation system, which will be selected for both passenger and freight transport, should be rapid, economic, safe, causing least harm to environment and appropriate for the conditions of a country. However, it is difficult for a transportation system to have all these properties. Every transportation system has advantages and disadvantages over each other. Therefore, comprehensive plans for future periods have to be prepared and how the sources of the country should be reasonably distributed among transportation systems must be investigated. Also, transportation plans have to be prepared to get coordinated operations among transportation systems while great investments are instituted in the entire country. There is no doubt that it is possible with combined transportation instead of concentration on one transportation system. Transportation policies in Turkey should be questioned since the level of highway transportation usage reaches to 95 % and level of sea transportation usage drops to less than 1 % in spite of being surrounded with sea in three sides of our land. In this paper, transportation systems and transportation policies in Turkey are evaluated in general and problems are analysed. Proposals are presented for the solutions of these problems.

  17. Wide gap, permanent magnet biased magnetic bearing system

    Science.gov (United States)

    Boden, Karl

    1992-01-01

    The unique features and applications of the presented electrical permanent magnetic bearing system essentially result from three facts: (1) the only bearing rotor components are nonlaminated ferromagnetic steel collars or cylinders; (2) all radial and axial forces are transmitted via radial gaps; and (3) large radial bearing gaps can be provided with minimum electric power consumption. The large gaps allow for effective encapsulation and shielding of the rotors at elevated or low temperatures, corrosive or ultra clean atmosphere or vacuum or high pressure environment. Two significant applications are described: (1) a magnetically suspended x ray rotary anode was operated under high vacuum conditions at 100 KV anode potential, 600 C temperature at the rotor collars and speed 18000 rpm with 13 mm radial bearing gap; and (2) an improved Czochralski type crystal growth apparatus using the hot wall method for pulling GaAs single crystals of low dislocation density. Both crystal and crucible are carried and transported by magnetically suspended shafts inside a hermetically sealed housing at 800 C shaft and wall temperature. The radial magnetic bearing gap measures 24 mm.

  18. Transport and magnetic properties of HITPERM alloys

    Science.gov (United States)

    Pekala, K.; Latuch, J.; Pekala, M.; Skorvanek, I.; Jaskiewicz, P.

    2003-02-01

    Nanocrystalline HITPERM alloys Fe44.6Co43.3X7.4B3.7Cu1 (X = Nb, Zr, Hf) prepared by crystallization of amorphous precursors are studied by magnetization and electrical resistivity measurements for the first time. Structural and magnetic components of the electrical resistivity are separated. The electrical resistivity of the nanocrystalline α' (FeCo) phase calculated using the Maxwell Garnett relation proves strong electron scattering on the grain boundaries. The temperature variation of the crystalline fraction during the first crystallization stage is calculated for the Hf based alloy.

  19. ANALYISIS OF TRANSPORTATION SYSTEMS AND TRANSPORTATION POLICIES IN TURKEY

    OpenAIRE

    Ali Payıdar AKGÜNGÖR; Abdulmuttalip DEMİREL

    2004-01-01

    Transportation systems have to be considered and analysed as a whole while transportation demand, becoming as a natural outcome of socioeconomic and socio-cultural structure, is being evaluated. It is desired that transportation system, which will be selected for both passenger and freight transport, should be rapid, economic, safe, causing least harm to environment and appropriate for the conditions of a country. However, it is difficult for a transportation system to have all these properti...

  20. Suprathermal ion transport in turbulent magnetized plasmas

    International Nuclear Information System (INIS)

    Bovet, A. D.

    2015-01-01

    Suprathermal ions, which have an energy greater than the quasi-Maxwellian background plasma temperature, are present in many laboratory and astrophysical plasmas. In fusion devices, they are generated by the fusion reactions and auxiliary heating. Controlling their transport is essential for the success of future fusion devices that could provide a clean, safe and abundant source of electric power to our society. In space, suprathermal ions include energetic solar particles and cosmic rays. The understanding of the acceleration and transport mechanisms of these particles is still incomplete. Basic plasma devices allow detailed measurements that are not accessible in astrophysical and fusion plasmas, due to the difficulty to access the former and the high temperatures of the latter. The basic toroidal device TORPEX offers an easy access for diagnostics, well characterized plasma scenarios and validated numerical simulations of its turbulence dynamics, making it the ideal platform for the investigation of suprathermal ion transport. This Thesis presents three-dimensional measurements of a suprathermal ion beam injected in turbulent TORPEX plasmas. The combination of uniquely resolved measurements and first principle numerical simulations reveals the general non-diffusive nature of the suprathermal ion transport. A precise characterization of their transport regime shows that, depending on their energies, suprathermal ions can experience either a super diffusive transport or a subdiffusive transport in the same background turbulence. The transport character is determined by the interaction of the suprathermal ion orbits with the turbulent plasma structures, which in turn depends on the ratio between the ion energy and the background plasma temperature. Time-resolved measurements reveal a clear difference in the intermittency of suprathermal ions time-traces depending on the transport regime they experience. Conditionally averaged measurements uncover the influence of

  1. Advanced Transport Operating Systems Program

    Science.gov (United States)

    White, John J.

    1990-01-01

    NASA-Langley's Advanced Transport Operating Systems Program employs a heavily instrumented, B 737-100 as its Transport Systems Research Vehicle (TRSV). The TRSV has been used during the demonstration trials of the Time Reference Scanning Beam Microwave Landing System (TRSB MLS), the '4D flight-management' concept, ATC data links, and airborne windshear sensors. The credibility obtainable from successful flight test experiments is often a critical factor in the granting of substantial commitments for commercial implementation by the FAA and industry. In the case of the TRSB MLS, flight test demonstrations were decisive to its selection as the standard landing system by the ICAO.

  2. Precision transport of LHC superconducting magnet

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    These photos show tests of the first convoy with a prototype short straight section (SSS) quadrupole in the LHC tunnel. There is little free space in the tunnel as the SSS convoy passes alongside a dipole vacuum vessel. These convoys feature infrared guidance, which offsets the minimal clearance in the tunnel and limits vibration, both of which could damage the fragile magnets.

  3. Safety of High Speed Magnetic Levitation Transportation Systems - Comparison of U.S. and Foreign Safety Requirements for Application to U.S. Maglev Systems

    Science.gov (United States)

    1993-09-01

    This report presents the results of a systematic review of the safety requirements selected for the German Transrapid : electromagnetic (EMS) type maglev system to determine their applicability and completeness with respect to the : construction and ...

  4. The magnet components database system

    International Nuclear Information System (INIS)

    Baggett, M.J.; Leedy, R.; Saltmarsh, C.; Tompkins, J.C.

    1990-01-01

    The philosophy, structure, and usage MagCom, the SSC magnet components database, are described. The database has been implemented in Sybase (a powerful relational database management system) on a UNIX-based workstation at the Superconducting Super Collider Laboratory (SSCL); magnet project collaborators can access the database via network connections. The database was designed to contain the specifications and measured values of important properties for major materials, plus configuration information (specifying which individual items were used in each cable, coil, and magnet) and the test results on completed magnets. These data will facilitate the tracking and control of the production process as well as the correlation of magnet performance with the properties of its constituents. 3 refs., 10 figs

  5. The magnet components database system

    International Nuclear Information System (INIS)

    Baggett, M.J.; Leedy, R.; Saltmarsh, C.; Tompkins, J.C.

    1990-01-01

    The philosophy, structure, and usage of MagCom, the SSC magnet components database, are described. The database has been implemented in Sybase (a powerful relational database management system) on a UNIX-based workstation at the Superconducting Super Collider Laboratory (SSCL); magnet project collaborators can access the database via network connections. The database was designed to contain the specifications and measured values of important properties for major materials, plus configuration information (specifying which individual items were used in each cable, coil, and magnet) and the test results on completed magnets. The data will facilitate the tracking and control of the production process as well as the correlation of magnet performance with the properties of its constituents. 3 refs., 9 figs

  6. The transport system approval concept

    International Nuclear Information System (INIS)

    Pettersson, B.G.

    1991-01-01

    The needs for, and merits of, a new concept for the safety assessment and approval of shipments of radioactive materials is introduced and discussed. The purpose of the new concept is to enable and encourage integration of analysis and review of transport safety with similar safety analysis and review of the handling operations involving the radioactive material at the despatching and receiving ends of a shipment. Safety contributing elements or functions of the means of transport (the Transport System) can thus readily be taken into account in the assessment. The objective is to avoid constraints -experienced or potential - introduced by the package functional provisions contained in the transport regulations, whilst maintaining safety during transport, as well as during facility handling operations, at least at the level at the level currently established. (author)

  7. Nanoparticulated magnetic drug delivery systems: Preparation and magnetic characterization

    Energy Technology Data Exchange (ETDEWEB)

    Morais, P C, E-mail: pcmor@unb.b [Universidade de BrasIlia, Instituto de Fisica, Nucleo de Fisica Aplicada, Brasilia DF 70910-900 (Brazil)

    2010-03-01

    This paper describes how magnetic resonance can be successfully used as a tool to help customize and quantify nanosized magnetic particles while labeling cells and administered in animals for targeting different biological sites. Customization of magnetic nanoparticles is addressed here in terms of production of complex magnetic drug delivery systems whereas quantification of magnetic nanoparticle in different biological compartments emerges as a key experimental information to assess time-dependent magnetic nanoparticle biodistribution profiles. Examples of using magnetic resonance in unfolding information regarding the pharmacokinetics of intravenously-injected surface-functionalized magnetic nanoparticles in animals are included in the paper.

  8. Thermal transport properties, magnetic susceptibility and neutron diffraction studies of the (Cr100-xAlx)95Mo5 alloy system

    Science.gov (United States)

    Muchono, B.; Sheppard, C. J.; Venter, A. M.; Prinsloo, A. R. E.

    2018-05-01

    The Seebeck coefficient has been used to investigate QCB in Cr alloys [8,9]. Plots of d S /d T (in the limit T → 2 K) as function of concentration for the (Cr97.8Si2.2)100-yMoy [8] and the (Cr84Re16)100-zVz [9] alloy systems depicted anomalies at the QCP. The possibility of QCB in the (Cr100-xAlx)95Mo5 alloy system is explored by analysing the S(T) data of Fig. 1 by performing a linear-least-squares fit through the 2 K < T < 6.5 K data points. The gradient was taken as dS / dT|T → 2K . Fig. 8 shows dS / dT|T → 2K for concentrations in the range 0.5 ≤ x ≤ 8.6. It increases rapidly to a maximum at x = 1.0, then decreases on further Al addition and displays a minimum just above x = 1.4. This is the concentration where magnetism is seen to disappear on the TN(x) magnetic phase diagram. dS / dT|T → 2K shows a second minimum just above x = 4.4, i.e. corresponding to the concentration where magnetism reappears on the TN(x) magnetic phase diagram (see Fig. 17). Similar minima were also observed at the QCP in the (Cr84Re16)100-zVz [9] and (Cr86Ru14)100-rVr [13] alloy systems. The relatively large error bars in Fig. 8 originate from the large errors in the fitting routine due to a significant scatter in the original Seebeck coefficient data at low temperatures. The solid line through the dS / dT|T → 2K data points is a guide to the eye, while the dotted vertical lines indicate the boundaries between the ISDW, P and CSDW phases. The minima observed in the dS / dT|T → 2K curve correlate to these boundaries.

  9. Effects of ExB velocity shear and magnetic shear on turbulence and transport in magnetic confinement devices

    International Nuclear Information System (INIS)

    Burrell, K.H.

    1996-11-01

    One of the scientific success stories of fusion research over the past decade is the development of the ExB shear stabilization model to explain the formation of transport barriers in magnetic confinement devices. This model was originally developed to explain the transport barrier formed at the plasma edge in tokamaks after the L (low) to H (high) transition. This concept has the universality needed to explain the edge transport barriers seen in limiter and divertor tokamaks, stellarators, and mirror machines. More recently, this model has been applied to explain the further confinement improvement from H (high)-mode to VH (very high)-mode seen in some tokamaks, where the edge transport barrier becomes wider. Most recently, this paradigm has been applied to the core transport barriers formed in plasmas with negative or low magnetic shear in the plasma core. These examples of confinement improvement are of considerable physical interest; it is not often that a system self-organizes to a higher energy state with reduced turbulence and transport when an additional source of free energy is applied to it. The transport decrease that is associated with ExB velocity shear effects also has significant practical consequences for fusion research. The fundamental physics involved in transport reduction is the effect of ExB shear on the growth, radial extent and phase correlation of turbulent eddies in the plasma. The same fundamental transport reduction process can be operational in various portions of the plasma because there are a number ways to change the radial electric field Er. An important theme in this area is the synergistic effect of ExB velocity shear and magnetic shear. Although the ExB velocity shear appears to have an effect on broader classes of microturbulence, magnetic shear can mitigate some potentially harmful effects of ExB velocity shear and facilitate turbulence stabilization

  10. ATLAS Magnet System Nearing Completion

    CERN Document Server

    ten Kate, H H J

    2008-01-01

    The ATLAS Detector at the Large Hadron Collider at CERN is equipped with a superconducting magnet system that consists of a Barrel Toroid, two End-Cap Toroids and a Central Solenoid. The four magnets generate the magnetic field for the muon- and inner tracking detectors, respectively. After 10 years of construction in industry, integration and on-surface tests at CERN, the magnets are now in the underground cavern where they undergo the ultimate test before data taking in the detector can start during the course of next year. The system with outer dimensions of 25 m length and 22 m diameter is based on using conduction cooled aluminum stabilized NbTi conductors operating at 4.6 K and 20.5 kA maximum coil current with peak magnetic fields in the windings of 4.1 T and a system stored magnetic energy of 1.6 GJ. The Barrel Toroid and Central Solenoid were already successfully charged after installation to full current in autumn 2006. This year the system is completed with two End Cap Toroids. The ultimate test of...

  11. Optimization of magnetic switches for single particle and cell transport

    Energy Technology Data Exchange (ETDEWEB)

    Abedini-Nassab, Roozbeh; Yellen, Benjamin B., E-mail: yellen@duke.edu [Department of Mechanical Engineering and Materials Science, Duke University, Box 90300 Hudson Hall, Durham, North Carolina 27708 (United States); Joint Institute, University of Michigan—Shanghai Jiao Tong University, Shanghai Jiao Tong University, Shanghai 200240 (China); Murdoch, David M. [Department of Medicine, Duke University, Durham, North Carolina 27708 (United States); Kim, CheolGi [Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 711-873 (Korea, Republic of)

    2014-06-28

    The ability to manipulate an ensemble of single particles and cells is a key aim of lab-on-a-chip research; however, the control mechanisms must be optimized for minimal power consumption to enable future large-scale implementation. Recently, we demonstrated a matter transport platform, which uses overlaid patterns of magnetic films and metallic current lines to control magnetic particles and magnetic-nanoparticle-labeled cells; however, we have made no prior attempts to optimize the device geometry and power consumption. Here, we provide an optimization analysis of particle-switching devices based on stochastic variation in the particle's size and magnetic content. These results are immediately applicable to the design of robust, multiplexed platforms capable of transporting, sorting, and storing single cells in large arrays with low power and high efficiency.

  12. Magnetic levitation in orbitron system

    International Nuclear Information System (INIS)

    Zub, S.S.

    2014-01-01

    This paper devoted to proof the existence of stable quasi-periodic motions of the magnetic dipole that is under the action of the external magnetic field and homogeneous field of gravity. For proof we used energy-momentum method that is the group-theoretic method of Hamiltonian mechanics. Numerical simulation shows the possibility of realization of stable motions with physically reasonable parameters of the system.

  13. Transport phenomena in particulate systems

    CERN Document Server

    Freire, José Teixeira; Ferreira, Maria do Carmo

    2012-01-01

    This volume spans 10 chapters covering different aspects of transport phenomena including fixed and fluidized systems, spouted beds, electrochemical and wastewater treatment reactors. This e-book will be valuable for students, engineers and researchers aiming to keep updated on the latest developments on particulate systems.

  14. Magnetic conveyor belt for transporting and merging trapped atom clouds.

    Science.gov (United States)

    Hänsel, W; Reichel, J; Hommelhoff, P; Hänsch, T W

    2001-01-22

    We demonstrate an integrated magnetic device which transports cold atoms near a surface with very high positioning accuracy. Time-dependent currents in a lithographic conductor pattern create a moving chain of potential wells; atoms are transported in these wells while remaining confined in all three dimensions. We achieve mean fluxes up to 10(6) s(-1) with a negligible heating rate. An extension of this device allows merging of atom clouds by unification of two Ioffe-Pritchard potentials. The unification, which we demonstrate experimentally, can be performed without loss of phase space density. This novel, all-magnetic atom manipulation offers exciting perspectives, such as trapped-atom interferometry.

  15. Transport and installation of the LHC cryo-magnets

    CERN Document Server

    Artoos, K; Capatina, O; Chevalley, JM; Foraz, K; Guinchard, M; Hauviller, Claude; Kershaw, K; Prodon, S; Rühl, Ingo; Trinquart, G; Weisz, S; Ponsot, P

    2007-01-01

    Eleven years have passed between the beginning of transport and handling studies in 1996 and the completion of the LHC cryo-magnets installation in 2007. More than 1700 heavy, long and fragile cryo-magnets had to be transported and installed in the 27 km long LHC tunnel with very restricted available space. The size and complexity of the project involved challenges in the field of equipment design and manufacturing, maintenance, training and follow-up of operators and logistics. The paper presents the milestones, problems to be overcome and lessons learned during this project.

  16. Local and Nonlocal Parallel Heat Transport in General Magnetic Fields

    International Nuclear Information System (INIS)

    Castillo-Negrete, D. del; Chacon, L.

    2011-01-01

    A novel approach for the study of parallel transport in magnetized plasmas is presented. The method avoids numerical pollution issues of grid-based formulations and applies to integrable and chaotic magnetic fields with local or nonlocal parallel closures. In weakly chaotic fields, the method gives the fractal structure of the devil's staircase radial temperature profile. In fully chaotic fields, the temperature exhibits self-similar spatiotemporal evolution with a stretched-exponential scaling function for local closures and an algebraically decaying one for nonlocal closures. It is shown that, for both closures, the effective radial heat transport is incompatible with the quasilinear diffusion model.

  17. NUHOMS transportation system interfaces

    International Nuclear Information System (INIS)

    McConaghy, W.J.; Lehnert, R.A.; Rasmussen, R.W.

    1989-01-01

    The NUHOMS system utilizes a reinforced concrete Horizontal Storage Module (HSM) to store spent nuclear fuel assemblies which are sealed in a Dry Shielded Canister (DSC). The DSC has an internal basket assembly designed to hold 24 PWR or 60 BWR spent fuel assemblies. The HSMs are constructed in interconnected arrays on the utilities reactor site with each HSM holding one DSC. The HSMs and DSCs are the principal components of the Independent Spent Fuel Storage Installation (ISFSI) for which plants are granted a 10CFR72 (1) license by the US Nuclear Regulatory Commission (NRC) for interim dry storage. A complete description of the NUHOMS system for dry storage of spent fuel and its operation is contained in the NRC approved NUHOMS Topical Report and related publications (2, 3, 4, 6)

  18. Intelligent Transport Systems in the Management of Road Transportation

    Science.gov (United States)

    Kalupová, Blanka; Hlavoň, Ivan

    2016-11-01

    Extension of European Union causes increase of free transfer of people and goods. At the same time they raised the problems associated with the transport, e.g. congestion and related accidents on roads, air traffic delays and more. To increase the efficiency and safety of transport, the European Commission supports the introduction of intelligent transport systems and services in all transport sectors. Implementation of intelligent transport systems and services in the road transport reduces accident frequency, increases the capacity of existing infrastructure and reduces congestions. Use of toll systems provides resources needed for the construction and operation of a new road network, improves public transport, cycling transport and walking transport, and also their multimodal integration with individual car transport.

  19. Magnet system news

    CERN Multimedia

    Laura Stewart

    In the first week of February the first End Cap Toroid was transported from its assembly hall in building 191 to the test station down on Arago road. It took two days to tighten the 240 ton toroid on the truck and to move it at a walking speed to its destination. So, there was plenty of time to take a nice picture of the team that worked so hard to meet the deadline. (left) End Cap Toroid A on the trailer on its way to the test. (right) The team that worked so hard to offer you this present! The End Cap Toroids is now outside building 180 on the cryogenic test station and will stay there for the next six weeks to undergo a full thermal cycling from about 280 Kelvin (yes, it's still cold in Geneva) down to 80 (just above the temperature of liquid nitrogen) and then hopefully up again to a sunny 300 Kelvin in March. This exercise will allow us to monitor its thermal, mechanical, electrical and vacuum characteristics, prior to its transport to point 1 and lowering into the cavern scheduled for the first ...

  20. The ALICE Magnetic System Computation.

    CERN Document Server

    Klempt, W; CERN. Geneva; Swoboda, Detlef

    1995-01-01

    In this note we present the first results from the ALICE magnetic system computation performed in the 3-dimensional way with the Vector Fields TOSCA code (version 6.5) [1]. To make the calculations we have used the IBM RISC System 6000-370 and 6000-550 machines combined in the CERN PaRC UNIX cluster.

  1. Spin-dependent tunneling transport in a lateral magnetic diode

    International Nuclear Information System (INIS)

    Wang, Yu; Shi, Ying

    2012-01-01

    Based on the gate-tunable two-dimensional electron gas, we have constructed laterally a double-barrier resonant tunneling structure by employing a peculiar triple-gate configuration, namely a ferromagnetic gate sandwiched closely by a pair of Schottky gates. Because of the in-plane stray field of ferromagnetic gate, the resulting bound spin state in well gives rise to the remarkable resonant spin polarization following the spin-dependent resonant tunneling regime. Importantly, by aligning the bound spin state through surface gate-voltage configuration, this resonant spin polarization can be externally manipulated, showing the desirable features for the spin-logic device applications. -- Highlights: ► A lateral spin-RTD was proposed by applying triple-gate modulated 2DEG. ► Spin-dependent resonant tunneling transport and large resonant spin polarization has been clarified from the systematic simulation. ► Both electric and/or magnetic strategies can be employed to modulate the system spin transport, providing the essential features for the spin-logic application.

  2. Electronic, magnetic and transport properties of graphene ribbons terminated by nanotubes

    International Nuclear Information System (INIS)

    Akhukov, M A; Yuan Shengjun; Fasolino, A; Katsnelson, M I

    2012-01-01

    We study, by density functional and large-scale tight-binding transport calculations, the electronic structure, magnetism and transport properties of the recently proposed graphene ribbons with edges rolled to form nanotubes. Edges with armchair nanotubes present magnetic moments localized either in the tube or the ribbon and of metallic or half-metallic character, depending on the symmetry of the junction. These properties have potential for spin valve and spin filter devices with advantages over other proposed systems. Edges with zigzag nanotubes are either metallic or semiconducting without affecting the intrinsic mobility of the ribbon. Varying the type and size of the nanotubes and ribbons offers the possibility to tailor the magnetic and transport properties, making these systems very promising for applications. (paper)

  3. Critical points in magnetic systems

    International Nuclear Information System (INIS)

    Bongaarts, A.L.M.

    1975-01-01

    The magnetical phase transitions of CsCoCl 3 .2H 2 O and CsCoCl 3 .2D 2 O are investigated by neutron diffraction techniques with special attention to the critical points in the phase diagrams. CsCoCl 3 .2H 2 O turned out to be a one-dimentional magnetic antiferromagnet with ferromagnetic and antiferromagnetic interactions. In the vicinity of the Neel point, the critical behavior in zero magnetic field could be described as a three-dimentional long range ordering, while the fluctuations in the system are one-dimensional. In the presence of a magnetic field, the behavior of the system in the critical region of the magnetic phase diagram between the Neel temperature at zero field (3.3degK) and 1.85degK, was in good agreement with the theory. Below 1.85degK, the phase transition in a magnetic field changes into a line of triple points whose end point could be identified as a tricritical point, i.e., an intersection of three critical lines. The parameters derived from observations in the neighborhood of this tricritical point obey the scaling laws but are not in numerical agreement with theoretical predictions

  4. Superconducting magnet systems for MRI

    International Nuclear Information System (INIS)

    Hawksworth, D.G.

    1988-01-01

    MRI is the first large scale commercial application of superconductivity and has not achieved the status of a mature industry with an annual turnover in the magnet industry alone in excess of $150M. Conservative estimates put the investment of the medical industry in MRI as a whole at more than a billion dollars. In the nine years since shipment of the first superconducting whole body imaging magnets of 0.3 Tesla field the standard product of the industry has become a system of 1 meter bore and field strength 0.5 Tesla to 1.5 Tesla. In this paper the evolution of present day MRI magnets from small bore but high field spectrometer magnets is reviewed and the direction of future developments discussed

  5. Surveillance systems for intermodal transportation

    Science.gov (United States)

    Jakovlev, Sergej; Voznak, Miroslav; Andziulis, Arunas

    2015-05-01

    Intermodal container monitoring is considered a major security issue in many major logistic companies and countries worldwide. Current representation of the problem, we face today, originated in 2002, right after the 9/11 attacks. Then, a new worldwide Container Security Initiative (CSI, 2002) was considered that shaped the perception of the transportation operations. Now more than 80 larger ports all over the world contribute to its further development and integration into everyday transportation operations and improve the regulations for the developing regions. Although, these new improvements allow us to feel safer and secure, constant management of transportation operations has become a very difficult problem for conventional data analysis methods and information systems. The paper deals with a proposal of a whole new concept for the improvement of the Containers Security Initiative (CSI) by virtually connecting safety, security processes and systems. A conceptual middleware approach with deployable intelligent agent modules is proposed to be used with possible scenarios and a testbed is used to test the solution. Middleware examples are visually programmed using National Instruments LabView software packages and Wireless sensor network hardware modules. An experimental software is used to evaluate he solution. This research is a contribution to the intermodal transportation and is intended to be used as a means or the development of intelligent transport systems.

  6. Structure and magnetic field of periodic permanent magnetic focusing system with open magnetic rings

    International Nuclear Information System (INIS)

    Peng Long; Li Lezhong; Yang Dingyu; Zhu Xinghua; Li Yuanxun

    2011-01-01

    The magnetic field along the central axis for an axially magnetized permanent magnetic ring was investigated by analytical and finite element methods. For open magnetic rings, both calculated and measured results show that the existence of the radial magnetic field creates a remarkable cosine distribution field along the central axis. A new structure of periodic permanent magnet focusing system with open magnetic rings is proposed. The structure provides a satisfactory magnetic field with a stable peak value of 120 mT for a traveling wave tube system. - Research highlights: → For open magnetic rings, both calculated and measured results show that the existence of the radial magnetic field creates a remarkable cosine distribution field along the central axis. → A new structure of periodic permanent magnet (PPM) focusing system with open magnetic rings is proposed. → The new PPM focusing system with open magnetic rings meets the requirements for TWT system.

  7. Electron heat transport in stochastic magnetic layer

    International Nuclear Information System (INIS)

    Becoulet, M.; Ghendrih, Ph.; Capes, H.; Grosman, A.

    1999-06-01

    Progress in the theoretical understanding of the local behaviour of the temperature field in ergodic layer was done in the framework of quasi-linear approach but this quasi-linear theory was not complete since the resonant modes coupling (due to stochasticity) was neglected. The stochastic properties of the magnetic field in the ergodic zone are now taken into account by a non-linear coupling of the temperature modes. The three-dimension heat transfer modelling in the ergodic-divertor configuration is performed by quasi-linear (ERGOT1) and non-linear (ERGOT2) numerical codes. The formalism and theoretical basis of both codes are presented. The most important effect that can be simulated with non-linear code is the averaged temperature profile flattening that occurs in the ergodic zone and the barrier creation that appears near the separatrix during divertor operation. (A.C.)

  8. Synthesis, structure, thermal, transport and magnetic properties of VN ceramics

    Czech Academy of Sciences Publication Activity Database

    Huber, Š.; Jankovský, O.; Sedmidubský, D.; Luxa, J.; Klimová, K.; Hejtmánek, Jiří; Sofer, Z.

    2016-01-01

    Roč. 42, č. 16 (2016), s. 18779-18784 ISSN 0272-8842 R&D Projects: GA ČR GA13-20507S Institutional support: RVO:68378271 Keywords : vanadium mononitride * phase transition * electronic structure * heat capacity * transport properties Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.986, year: 2016

  9. Quantum transport in complex system

    International Nuclear Information System (INIS)

    Kusnezov, D.; Bulgac, A.; DoDang, G.

    1998-01-01

    We derive the influence function and the effective dynamics of a quantum systems coupled to a chaotic environment, using very general parametric and banded random matrices to describe the quantum properties of a chaotic bath. We find that only in certain limits the thermalization can result from the environment. We study the general transport problems including escape, fusion and tunneling (fission). (author)

  10. Nanoparticles for magnetic biosensing systems

    International Nuclear Information System (INIS)

    Kurlyandskaya, G.V.; Novoselova, Iu.P.; Schupletsova, V.V.; Andrade, R.; Dunec, N.A.; Litvinova, L.S.; Safronov, A.P.; Yurova, K.A.; Kulesh, N.A.; Dzyuman, A.N.; Khlusov, I.A.

    2017-01-01

    The further development of magnetic biosensors requires a better understanding of the interaction between living systems and magnetic nanoparticles (MNPs). We describe our experience of fabrication of stable ferrofluids (FF) using electrostatic or steric stabilization of iron oxide MNPs obtained by laser target evaporation. Controlled amounts of FF were used for in vitro experiments with human mesenchymal stem cells. Their morphofunctional responses in the Fe concentration range 2–1000 maximum tolerated dose revealed no cytotoxicity. - Highlights: • Stable ferrofluids (FF) were obtained using electrostatic or steric stabilization of iron oxide MNPs obtained by laser target evaporation. • Controlled amounts of FF were used for in vitro experiments with human mesenchymal stem cells. • Cells morphofunctional response in the Fe concentration range 2–1000 maximum tolerated dose revealed no cytotoxicity. • The results can be used for magnetic biosensoring, as well as for an addressed design of cell delivery systems.

  11. Nanoparticles for magnetic biosensing systems

    Energy Technology Data Exchange (ETDEWEB)

    Kurlyandskaya, G.V., E-mail: galina@we.lc.ehu.es [Universidad del País Vasco BCMaterials UPV-EHU, Leioa, 48940 Spain (Spain); Ural Federal University, Ekaterinburg, 620000 (Russian Federation); Novoselova, Iu.P. [Ural Federal University, Ekaterinburg, 620000 (Russian Federation); Schupletsova, V.V. [I.Kant Baltic Federal University, Kaliningrad, 23601 (Russian Federation); Andrade, R. [SGIker, ServiciosGenerales de Investigación, Universidad del País Vasco (UPV/EHU), Bilbao, 48080 Spain (Spain); Dunec, N.A.; Litvinova, L.S. [I.Kant Baltic Federal University, Kaliningrad, 23601 (Russian Federation); Safronov, A.P. [Ural Federal University, Ekaterinburg, 620000 (Russian Federation); Institute of Electrophysics, Ural Division, RAS, Ekaterinburg, 620016 (Russian Federation); Yurova, K.A. [I.Kant Baltic Federal University, Kaliningrad, 23601 (Russian Federation); Kulesh, N.A. [Ural Federal University, Ekaterinburg, 620000 (Russian Federation); Dzyuman, A.N. [Siberian State Medical University, Tomsk, 634050 (Russian Federation); Khlusov, I.A. [Siberian State Medical University, Tomsk, 634050 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2017-06-01

    The further development of magnetic biosensors requires a better understanding of the interaction between living systems and magnetic nanoparticles (MNPs). We describe our experience of fabrication of stable ferrofluids (FF) using electrostatic or steric stabilization of iron oxide MNPs obtained by laser target evaporation. Controlled amounts of FF were used for in vitro experiments with human mesenchymal stem cells. Their morphofunctional responses in the Fe concentration range 2–1000 maximum tolerated dose revealed no cytotoxicity. - Highlights: • Stable ferrofluids (FF) were obtained using electrostatic or steric stabilization of iron oxide MNPs obtained by laser target evaporation. • Controlled amounts of FF were used for in vitro experiments with human mesenchymal stem cells. • Cells morphofunctional response in the Fe concentration range 2–1000 maximum tolerated dose revealed no cytotoxicity. • The results can be used for magnetic biosensoring, as well as for an addressed design of cell delivery systems.

  12. Fast electron generation and transport in a turbulent, magnetized plasma

    International Nuclear Information System (INIS)

    Stoneking, W.R.

    1994-05-01

    The nature of fast electron generation and transport in the Madison Symmetric Torus (MST) reversed field pinch (RFP) is investigated using two electron energy analyzer (EEA) probes and a thermocouple calorimeter. The parallel velocity distribution of the fast electron population is well fit by a drifted Maxwellian distribution with temperature of about 100 eV and drift velocity of about 2 x 10 6 m/s. Cross-calibration of the EEA with the calorimeter provides a measurement of the fast electron perpendicular temperature of 30 eV, much lower than the parallel temperature, and is evidence that the kinetic dynamo mechanism (KDT) is not operative in MST. The fast electron current is found to match to the parallel current at the edge, and the fast electron density is about 4 x 10 11 cm -3 independent of the ratio of the applied toroidal electric field to the critical electric field for runaways. First time measurements of magnetic fluctuation induced particle transport are reported. By correlating electron current fluctuations with radial magnetic fluctuations the transported flux of electrons is found to be negligible outside r/a∼0.9, but rises the level of the expected total particle losses inside r/a∼0.85. A comparison of the measured diffusion coefficient is made with the ausilinear stochastic diffusion coefficient. Evidence exists that the reduction of the transport is due to the presence of a radial ambipolar electric field of magnitude 500 V/m, that acts to equilibrate the ion and electron transport rates. The convective energy transport associated with the measured particle transport is large enough to account for the observed magnetic fluctuation induced energy transport in MST

  13. Optimal concentrations in transport systems

    Science.gov (United States)

    Jensen, Kaare H.; Kim, Wonjung; Holbrook, N. Michele; Bush, John W. M.

    2013-01-01

    Many biological and man-made systems rely on transport systems for the distribution of material, for example matter and energy. Material transfer in these systems is determined by the flow rate and the concentration of material. While the most concentrated solutions offer the greatest potential in terms of material transfer, impedance typically increases with concentration, thus making them the most difficult to transport. We develop a general framework for describing systems for which impedance increases with concentration, and consider material flow in four different natural systems: blood flow in vertebrates, sugar transport in vascular plants and two modes of nectar drinking in birds and insects. The model provides a simple method for determining the optimum concentration copt in these systems. The model further suggests that the impedance at the optimum concentration μopt may be expressed in terms of the impedance of the pure (c = 0) carrier medium μ0 as μopt∼2αμ0, where the power α is prescribed by the specific flow constraints, for example constant pressure for blood flow (α = 1) or constant work rate for certain nectar-drinking insects (α = 6). Comparing the model predictions with experimental data from more than 100 animal and plant species, we find that the simple model rationalizes the observed concentrations and impedances. The model provides a universal framework for studying flows impeded by concentration, and yields insight into optimization in engineered systems, such as traffic flow. PMID:23594815

  14. Magnetic property effect on transport processes in resistance spot welding

    Energy Technology Data Exchange (ETDEWEB)

    Wei, P S [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan 80424 (China); Wu, T H, E-mail: pswei@mail.nsysu.edu.tw, E-mail: wux0064@gmail.com [Department of Mechanical Engineering, Yung Ta Institute of Technology and Commerce, Pintong, Taiwan 909 (China)

    2011-08-17

    This study investigates the effects of the Curie temperature and magnetic permeability on transport variables, solute distribution and nugget shapes during resistance spot welding. The Curie temperature is the temperature below which a metal or alloy is ferromagnetic with a high magnetic permeability, and above which it is paramagnetic with a small magnetic permeability. The model proposed here accounts for electromagnetic force, heat generation and contact resistance at the faying surface and electrode-workpiece interfaces and bulk resistance in workpieces. Contact resistance includes constriction and film resistances, which are functions of hardness, temperature, electrode force and surface condition. The computed results show that transport variables and nugget shapes can be consistently interpreted from the delay of response time and jump of electric current density as a result of finite magnetic diffusion, rather than through the examination of the variations of dynamic electrical resistance with time. The molten nugget on the faying surface is initiated earlier with increasing magnetic permeability and Curie temperature. A high Curie temperature enhances convection and solute mixing, and readily melts through the workpiece surface near the electrode edge. Any means to reduce the Curie temperature or magnetic permeability, such as adjusting the solute content, can be a good way to control weld quality. This study can also be applied to interpret the contact problems encountered in various electronics and packaging technologies, and so on.

  15. Transport of solar electrons in the turbulent interplanetary magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Ablaßmayer, J.; Tautz, R. C., E-mail: robert.c.tautz@gmail.com [Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Hardenbergstraße 36, D-10623 Berlin (Germany); Dresing, N., E-mail: dresing@physik.uni-kiel.de [Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Leibnizstraße 11, D-24118 Kiel (Germany)

    2016-01-15

    The turbulent transport of solar energetic electrons in the interplanetary magnetic field is investigated by means of a test-particle Monte-Carlo simulation. The magnetic fields are modeled as a combination of the Parker field and a turbulent component. In combination with the direct calculation of diffusion coefficients via the mean-square displacements, this approach allows one to analyze the effect of the initial ballistic transport phase. In that sense, the model complements the main other approach in which a transport equation is solved. The major advancement is that, by recording the flux of particles arriving at virtual detectors, intensity and anisotropy-time profiles can be obtained. Observational indications for a longitudinal asymmetry can thus be explained by tracing the diffusive spread of the particle distribution. The approach may be of future help for the systematic interpretation of observations for instance by the solar terrestrial relations observatory (STEREO) and advanced composition explorer (ACE) spacecrafts.

  16. Neoclassical transport in toroidal systems

    International Nuclear Information System (INIS)

    Wobig, H.

    1992-01-01

    The neoclassical theory of general toroidal equilibria is reformulated. The toroidal equilibrium of tokamaks and stellarators are described in Hamada coordinates. The relevant geometrical parameters are identified and it is shown how the reduction of Pfirsch-Schluter currents affects neoclassical transport and bootstrap effects. General flux-friction relations between thermodynamic forces and fluxes are derived. In drift-kinetic approximation the neoclassical transport coefficients are Onsager symmetric. Since a toroidal loop voltage is included, the theory is valid for all toroidal systems. (Author)

  17. A practical nonlocal model for heat transport in magnetized laser plasmas

    International Nuclear Information System (INIS)

    Nicolaie, Ph.D.; Feugeas, J.-L.A.; Schurtz, G.P.

    2006-01-01

    A model of nonlocal transport for multidimensional radiation magnetohydrodynamics codes is presented. In laser produced plasmas, it is now believed that the heat transport can be strongly modified by the nonlocal nature of the electron conduction. Other mechanisms, such as self-generated magnetic fields, may also affect the heat transport. The model described in this work, based on simplified Fokker-Planck equations aims at extending the model of G. Schurtz, Ph. Nicolaie, and M. Busquet [Phys. Plasmas 7, 4238 (2000)] to magnetized plasmas. A complete system of nonlocal equations is derived from kinetic equations with self-consistent electric and magnetic fields. These equations are analyzed and simplified in order to be implemented into large laser fusion codes and coupled to other relevant physics. The model is applied to two laser configurations that demonstrate the main features of the model and point out the nonlocal Righi-Leduc effect in a multidimensional case

  18. A practical nonlocal model for heat transport in magnetized laser plasmas

    Science.gov (United States)

    Nicolaï, Ph. D.; Feugeas, J.-L. A.; Schurtz, G. P.

    2006-03-01

    A model of nonlocal transport for multidimensional radiation magnetohydrodynamics codes is presented. In laser produced plasmas, it is now believed that the heat transport can be strongly modified by the nonlocal nature of the electron conduction. Other mechanisms, such as self-generated magnetic fields, may also affect the heat transport. The model described in this work, based on simplified Fokker-Planck equations aims at extending the model of G. Schurtz, Ph. Nicolaï, and M. Busquet [Phys. Plasmas 7, 4238 (2000)] to magnetized plasmas. A complete system of nonlocal equations is derived from kinetic equations with self-consistent electric and magnetic fields. These equations are analyzed and simplified in order to be implemented into large laser fusion codes and coupled to other relevant physics. The model is applied to two laser configurations that demonstrate the main features of the model and point out the nonlocal Righi-Leduc effect in a multidimensional case.

  19. Integrated Intermodal Passenger Transportation System

    Science.gov (United States)

    Klock, Ryan; Owens, David; Schwartz, Henry; Plencner, Robert

    2012-01-01

    Modern transportation consists of many unique modes of travel. Each of these modes and their respective industries has evolved independently over time, forming a largely incoherent and inefficient overall transportation system. Travelers today are forced to spend unnecessary time and efforts planning a trip through varying modes of travel each with their own scheduling, pricing, and services; causing many travelers to simply rely on their relatively inefficient and expensive personal automobile. This paper presents a demonstration program system to not only collect and format many different sources of trip planning information, but also combine these independent modes of travel in order to form optimal routes and itineraries of travel. The results of this system show a mean decrease in inter-city travel time of 10 percent and a 25 percent reduction in carbon dioxide emissions over personal automobiles. Additionally, a 55 percent reduction in carbon dioxide emissions is observed for intra-city travel. A conclusion is that current resources are available, if somewhat hidden, to drastically improve point to point transportation in terms of time spent traveling, the cost of travel, and the ecological impact of a trip. Finally, future concepts are considered which could dramatically improve the interoperability and efficiency of the transportation infrastructure.

  20. System Convergence in Transport Modelling

    DEFF Research Database (Denmark)

    Rich, Jeppe; Nielsen, Otto Anker; Cantarella, Guilio E.

    2010-01-01

    A fundamental premise of most applied transport models is the existence and uniqueness of an equilibrium solution that balances demand x(t) and supply t(x). The demand consists of the people that travel in the transport system and on the defined network, whereas the supply consists of the resulting...... level-of-service attributes (e.g., travel time and cost) offered to travellers. An important source of complexity is the congestion, which causes increasing demand to affect travel time in a non-linear way. Transport models most often involve separate models for traffic assignment and demand modelling...... iterating between a route-choice (demand) model and a time-flow (supply) model. It is generally recognised that a simple iteration scheme where the level-of-service level is fed directly to the route-choice and vice versa may exhibit an unstable pattern and lead to cyclic unstable solutions. It can be shown...

  1. Collapse of ferromagnetism in itinerant-electron system: a magnetic, transport properties, and high pressure study of (Hf,Ta)Fe.sub.2./sub. compounds

    Czech Academy of Sciences Publication Activity Database

    Diop, L.; Kaštil, Jiří; Isnard, O.; Arnold, Zdeněk; Kamarád, Jiří

    2014-01-01

    Roč. 116, č. 16 (2014), "163907-1"-"163907-10" ISSN 0021-8979 R&D Projects: GA ČR GAP204/12/0692 Institutional support: RVO:68378271 Keywords : high pressure * magnetic properties Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2014

  2. Magnetism in Pd: Magnetoconductance and transport spectroscopy of atomic contacts

    Science.gov (United States)

    Strigl, F.; Keller, M.; Weber, D.; Pietsch, T.; Scheer, E.

    2016-10-01

    Since the rapid technological progress demands for ever smaller storage units, the emergence of stable magnetic order in nanomaterials down to the single-atom regime has attracted huge scientific attention to date. Electronic transport spectroscopy has been proven to be a versatile tool for the investigation of electronic, magnetic, and mechanical properties of atomic contacts. Here we report a comprehensive experimental study of the magnetoconductance and electronic properties of Pd atomic contacts at low temperature. The analysis of electronic transport (d I /d V ) spectra and the magnetoconductance curves yields a diverse behavior of Pd single-atom contacts, which is attributed to different contact configurations. The magnetoconductance shows a nonmonotonous but mostly continuous behavior, comparable to those found in atomic contacts of band ferromagnets. In the d I /d V spectra, frequently, a pronounced zero-bias anomaly (ZBA) as well as an aperiodic and nonsymmetric fluctuation pattern are observed. While the ZBA can be interpreted as a sign of the Kondo effect, suggesting the presence of magnetic impurity, the fluctuations are evaluated in the framework of conductance fluctuations in relation to the magnetoconductance traces and to previous findings in Au atomic contacts. This thorough analysis reveals that the magnetoconductance and transport spectrum of Au atomic contacts can completely be accounted for by conductance fluctuations, while in Pd contacts the presence of local magnetic order is required.

  3. Canadian high speed magnetically levitated vehicle system

    Energy Technology Data Exchange (ETDEWEB)

    Atherton, D L [Queen' s Univ., Kingston, Ont.; Belanger, P R; Burke, P E; Dawson, G E; Eastham, A R; Hayes, W F; Ooi, B T; Silvester, P; Slemon, G R

    1978-04-01

    A technically feasible high speed (400 to 480 km/h) guided ground transportation system, based on the use of the vehicle-borne superconducting magnets for electrodynamic suspension and guidance and for linear synchronous motor propulsion was defined as a future modal option for Canadian application. Analysis and design proposals were validated by large-scale tests on a rotating wheel facility and by modelling system components and their interactions. Thirty ton vehicles carrying 100 passengers operate over a flat-topped elevated guideway, which minimizes system down-time due to ice and snow accumulation and facilitates the design of turn-outs. A clearance of up to 15 cm is produced by the electrodynamic interaction between the vehicle-borne superconducting magnets and aluminum guideway strips. Propulsion and automatic system control is provided by the superconducting linear synchronous motor which operates at good efficiency (0.74) and high power factor (0.95). The vehicle is guided primarily by the interaction between the LSM field magnet array and flat null-flux loops overlying the stator windings in the guideway. The linear synchronous motor, electrodynamic suspension as well as levitation strip joints, parasitic LSM winding losses and limitations to the use of ferromagnetic guideway reinforcement were investigated experimentally on the test wheel facility. The use of a secondary suspension assures adequate dynamic stability, and good ride quality is achieved by optimized passive components with respect to lateral modes and by an actively controlled secondary suspension with respect to vertical motion.

  4. Workshop on technology issues of superconducting Maglev transportation systems

    International Nuclear Information System (INIS)

    Wegrzyn, J.E.; Shaw, D.T.

    1991-01-01

    There exists a critical need in the United States to improve its ground transportation system. One suggested system that offers many advantages over the current transportation infrastructure is Maglev. Maglev represents the latest evolution in very high and speed ground transportation, where vehicles are magnetically levitated, guided, and propelled over elevated guideways at speeds of 300 miles per hour. Maglev is not a new concept but is, however, receiving renewed interest. The objective of this workshop was to further promote these interest by bringing together a small group of specialists in Maglev technology to discuss Maglev research needs and to identify key research issues to the development of a successful Maglev system. The workshop was organized into four sessions based on the following technical areas: Materials, Testing, and Shielding; Magnet Design and Cryogenic Systems; Propulsion and Levitation Systems; and, System Control and Integration

  5. Bending magnets for the CBA beam-transport line

    Energy Technology Data Exchange (ETDEWEB)

    Thern, R.E.

    1983-01-01

    The beam-transport line from the AGS to CBA requires 68 large bending magnets, consisting of pure dipoles and two types of combined function gradient magnets. All three types were designed with magnetic-field calculation program POISSON, using the same exterior dimensions and coil package. The design goal of +-1% momentum acceptance for the transport line required a wide horizontal aperture, with a much-smaller vertical aperture for economy. Two prototypes of one gradient magnet were built, and a facility constructed to measure them and the later production magnets. Measurements were done using both a long coil and a point coil (Rawson-Lush gaussmeter). Preliminary results show ..delta..B/B < 0.2 x 10/sup -3/, ..delta..G/G < 0.3 x 10/sup -2/, and ..delta..B/sub 2//B < 0.3 x 10/sup -4/ cm/sup -2/ over the beam aperture. Due to end effects, the actual gradient differs from the design gradient by 1%, which has been compensated for in the beam-line design.

  6. Magnetic Modulation of the Transport of Organophilic Solutes through Supported Magnetic Ionic Liquid Membranes.

    Czech Academy of Sciences Publication Activity Database

    Daniel, C.L.; Rubio, A.M.; Sebastião, P.J.; Afonso, C.A.M.; Storch, Jan; Izák, Pavel; Portugal, C.A.M.; Crespo, J.G.

    2016-01-01

    Roč. 505, MAY 1 (2016), s. 36-43 ISSN 0376-7388 R&D Projects: GA ČR(CZ) GAP106/12/0569 Grant - others:ERANET(PT) ERA-CHEM/0001/2008; EUI(ES) 2008- 03857; FCT-MCTES(PT) SFRH/BD/81552/2011 Institutional support: RVO:67985858 Keywords : magnetic ionic liquids (MILs) * solute transport modulation * magnetic field Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 6.035, year: 2016

  7. The effects of magnetic fringe fields on beam dynamics in a beam transport line of a terahertz FEL source

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Han [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Xiong, Yongqian, E-mail: yqxiong@mail.hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Pei, Yuanji [National Synchrotron Radiation laboratory, University of Science and Technology of China, Hefei 230029, Anhui (China)

    2014-11-11

    The transport line used in a terahertz FEL device has to transport electron beam through the entire system efficiently and meet the requirements of the beam parameters at the undulator entrance. Due to space limitations, the size of the magnets (five quadrupoles and two bending magnets) employed in the transport line was limited, and some devices were densely packed. In this paper, analyses of the effect of fringe fields and magnetic interference of magnets are presented. 3D models of these magnets are built and their linear optical properties are compared with those obtained by hard edge models. The results indicated that the effects of these factors are significant and they would cause a mismatch of the beam at the exit of the transport line under the preliminary lattice design. To solve this problem, the beam was re-matched using the particle swarm optimization algorithm.

  8. Influence of magnetic topology on transport and stability in stellarators

    Energy Technology Data Exchange (ETDEWEB)

    Castejon, F [Laboratorio Nacional de Fusion. Asociacion Euratom/Ciemat, 28040-Madrid (Spain); Fujisawa, A [National Institute for Fusion Science Oroshi-cho, Toki-shi, Gifu, 509-5292 (Japan); Ida, K [National Institute for Fusion Science Oroshi-cho, Toki-shi, Gifu, 509-5292 (Japan); Talmadge, J N [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Estrada, T [Laboratorio Nacional de Fusion. Asociacion Euratom/Ciemat, 28040-Madrid (Spain); Lopez-Bruna, D [Laboratorio Nacional de Fusion. Asociacion Euratom/Ciemat, 28040-Madrid (Spain); Hidalgo, C [Laboratorio Nacional de Fusion. Asociacion Euratom/Ciemat, 28040-Madrid (Spain); Krupnik, L [Institute of Plasma Physics, NSC ' KIPT' , Kharkov (Ukraine); Melnikov, A [Institute of Nuclear Fusion, RRC ' Kurchatov Institute' , Moscow (Russian Federation)

    2005-12-15

    The influence of the magnetic topology on transport and stability has been investigated in four stellarators: an almost shearless medium size flexible heliac (TJ-II), a medium size and a large heliotron (CHS and LHD) with shear, and a quasihelically symmetric device (HSX) with moderate shear. All of these have variable rotational transform profiles and magnetic ripples. Using these capabilities, bifurcated states can appear and plasma can jump from one to another with subsequent changes in the transport properties. Low rational values of {iota}/2{pi} can create transport barriers in LHD and TJ-II when they are located close to the plasma core or at the edge. The key ingredient for transport barriers is a positive and sheared electric field. Internal transport barriers also appear in CHS, but the role of rationals is not clear yet in this device. The time evolution of the electric field shows the onset of a bifurcation triggered either by the rational or by the presence of the ion and electron roots. The electric potential inside ITBs follows the ECE-temperature profile in a fast time scale. The plasma stability properties and its effect on the viscosity are also studied in the HSX, and the influence of the dynamics of rational surface is studied in the LHD and TJ-II stellarators.

  9. Influence of magnetic topology on transport and stability in stellarators

    International Nuclear Information System (INIS)

    Castejon, F; Fujisawa, A; Ida, K; Talmadge, J N; Estrada, T; Lopez-Bruna, D; Hidalgo, C; Krupnik, L; Melnikov, A

    2005-01-01

    The influence of the magnetic topology on transport and stability has been investigated in four stellarators: an almost shearless medium size flexible heliac (TJ-II), a medium size and a large heliotron (CHS and LHD) with shear, and a quasihelically symmetric device (HSX) with moderate shear. All of these have variable rotational transform profiles and magnetic ripples. Using these capabilities, bifurcated states can appear and plasma can jump from one to another with subsequent changes in the transport properties. Low rational values of ι/2π can create transport barriers in LHD and TJ-II when they are located close to the plasma core or at the edge. The key ingredient for transport barriers is a positive and sheared electric field. Internal transport barriers also appear in CHS, but the role of rationals is not clear yet in this device. The time evolution of the electric field shows the onset of a bifurcation triggered either by the rational or by the presence of the ion and electron roots. The electric potential inside ITBs follows the ECE-temperature profile in a fast time scale. The plasma stability properties and its effect on the viscosity are also studied in the HSX, and the influence of the dynamics of rational surface is studied in the LHD and TJ-II stellarators

  10. Kinetic Theory of Electronic Transport in Random Magnetic Fields

    Science.gov (United States)

    Lucas, Andrew

    2018-03-01

    We present the theory of quasiparticle transport in perturbatively small inhomogeneous magnetic fields across the ballistic-to-hydrodynamic crossover. In the hydrodynamic limit, the resistivity ρ generically grows proportionally to the rate of momentum-conserving electron-electron collisions at large enough temperatures T . In particular, the resulting flow of electrons provides a simple scenario where viscous effects suppress conductance below the ballistic value. This new mechanism for ρ ∝T2 resistivity in a Fermi liquid may describe low T transport in single-band SrTiO3 .

  11. Magnetic Actuation of Biological Systems

    Science.gov (United States)

    Lauback, Stephanie D.

    Central to the advancement of many biomedical and nanotechnology capabilities is the capacity to precisely control the motion of micro and nanostructures. These applications range from single molecule experiments to cell isolation and separation, to drug delivery and nanomachine manipulation. This dissertation focuses on actuation of biological micro- and nano-entities through the use of weak external magnetic fields, superparamagnetic beads, and ferromagnetic thin films. The magnetic platform presents an excellent method for actuation of biological systems due to its ability to directly control the motion of an array of micro and nanostructures in real-time with calibrated picoNewton forces. The energy landscape of two ferromagnetic thin film patterns (disks and zigzag wires) is experimentally explored and compared to corresponding theoretical models to quantify the applied forces and trajectories of superparamagnetic beads due to the magnetic traps. A magnetic method to directly actuate DNA nanomachines in real-time with nanometer resolution and sub-second response times using micromagnetic control was implemented through the use of stiff DNA micro-levers which bridged the large length scale mismatch between the micro-actuator and the nanomachine. Compared to current alternative methods which are limited in the actuation speeds and the number of reconfiguration states of DNA constructs, this magnetic approach enables fast actuation (˜ milliseconds) and reconfigurable conformations achieved through a continuous range of finely tuned steps. The system was initially tested through actuation of the stiff arm tethered to the surface, and two prototype DNA nanomachines (rotor and hinge) were successfully actuated using the stiff mechanical lever. These results open new possibilities in the development of functional robotic systems at the molecular scale. In exploiting the use of DNA stiff levers, a new technique was also developed to investigate the emergence of the

  12. Development of magnetic drug delivery system using HTS bulk magnet

    International Nuclear Information System (INIS)

    Terada, T.; Fukui, S.; Mishima, F.; Akiyama, Y.; Izumi, Y.; Nishijima, S.

    2008-01-01

    Magnetic drug delivery system (MDDS) is the method which the magnetic seeded drug is injected into a blood vessel and then controlled and accumulated by a magnet located outside of the human body. A high accumulation efficiency of the drug to a local diseased part and reduction in side-effects to normal organs are expected by using MDDS. The most important element in MDDS is a magnetic field generator. The high temperature superconducting (HTS) bulk magnet which can generate high magnetic field and magnetic field gradient extending to a point distant from the magnet in several ten millimeters is necessary to achieve the MDDS. In this study, the computer simulation and model experiment were conducted in order to confirm the applicability of MDDS to ovary of the cow body

  13. Hybrid simulations of plasma transport by Kelvin-Helmholtz instability at the magnetopause: magnetic shear

    Energy Technology Data Exchange (ETDEWEB)

    Cowee, Misa M [Los Alamos National Laboratory; Winske, Dan [Los Alamos National Laboratory; Gary, S Peter [Los Alamos National Laboratory

    2009-01-01

    Two-dimensional hybrid (kinetic ions, massless fluid electrons) simulations of the Kelvin Helmholtz Instability (KHI) for a magnetopause configuration with a magnetic shear across the boundary are carried out to examine how the transport of magnetosheath plasma into the magnetosphere is affected by the shear field. Low magnetic shear conditions where the magnetosheath magnetic field is within 30{sup o} of northward is included in the simulations because KHI is thought to be important for plasma transport only for northward or near-northward interplanetary magnetic field orientations. The simulations show that coherent vortices can grow for these near-northward angles, and that they are sometimes more coherent than for pure northward conditions because the turbulence which breaks-down these vortices is reduced when there are magnetic tension forces. With increasing magnetic shear angle, the growth rate is reduced, and the vortices do not grow to as large of size which reduces the plasma transport. By tracking the individual particle motions diffusion coefficients can be obtained for the system, where the diffusion is not classical in nature but instead has a time dependence resulting from both the increasingly large-scale vortex motion and the small-scale turbulence generated in the break-down of the instabilities. Results indicate that diffusion on the order of 10{sup 9} m{sup 2}/s could possibly be generated by KHI on the flanks of the magnetosphere.

  14. Physical System Requirements: Transport Waste

    International Nuclear Information System (INIS)

    1992-04-01

    The Nuclear Waste Policy Act (NWPA) of 1982 assigned to the Department of Energy (DOE) the responsibility for managing the disposal of spent nuclear fuel and high-level radioactive waste and established the Office of Civilian Radioactive Waste Management (OCRWM) for that purpose. The Secretary of Energy, in his November 1989 report to Congress (DOE/RW-0247), announced three new initiatives for the conduct of the Civilian Radioactive Waste Management (CRWM) program. One of these initiatives was to establish improved management structure and procedures. In response, OCRWM performed a management study and the Director subsequently issued the Management Systems Improvement Strategy (MSIS) on August 10, 1990, calling for a rigorous implementation of systems engineering principles with a special emphasis on functional analysis. The functional analysis approach establishes a framework for integrating the program management efforts with the technical requirements analysis into a single, unified, and consistent program. This approach recognizes that just as the facilities and equipment comprising the physical waste management system must perform certain functions, so must certain programmatic and management functions be performed within the program in order to successfully bring the physical system into being. The objective of this document is to establish the essential functions, requirements, interfaces, and system architecture for the Transport Waste mission. Based upon the Nuclear Waste Policy Act, the mission of the Waste Transportation System is to transport SNF and/or HLW from the purchaser's/producer's facilities to, and between, NWMS facilities in a manner that protects the health and safety of the public and of workers and the quality of the environment makes effective use of financial and other resources, and to the fullest extent possible uses the private sector

  15. Turbulence and intermittent transport at the boundary of magnetized plasmas

    DEFF Research Database (Denmark)

    Garcia, O.E.; Naulin, V.; Nielsen, A.H.

    2005-01-01

    Numerical fluid simulations of interchange turbulence for geometry and parameters relevant to the boundary region of magnetically confined plasmas are shown to result in intermittent transport qualitatively similar to recent experimental measurements. The two-dimensional simulation domain features...... a forcing region with spatially localized sources of particles and heat outside which losses due to the motion along open magnetic-field lines dominate, corresponding to the edge region and the scrape-off layer, respectively. Turbulent states reveal intermittent eruptions of hot plasma from the edge region...... fluctuation wave forms and transport statistics are also in a good agreement with those derived from the experiments. Associated with the turbulence bursts are relaxation oscillations in the particle and heat confinements as well as in the kinetic energy of the sheared poloidal flows. The formation of blob...

  16. Measurement system for SSRF pulsed magnets

    International Nuclear Information System (INIS)

    Peng Chengcheng; Gu Ming; Liu Bo; Ouyang Lianhua

    2007-01-01

    This paper describes the magnetic field measurement system for pulsed magnets in SSRF. The system consists of magnetic probes, analog active integrator, oscilloscope, stepper motor and a controller. An application program based on LabVIEW has been developed as main control unit. After the magnetic field mapping of a septum magnet prototype, it is verified that the test results accord with the results of theoretical calculation and computer simulation. (authors)

  17. Transport and magnetic resonance in normal and superfluid Fermi liquids

    International Nuclear Information System (INIS)

    Smith, H.

    1976-10-01

    This thesis provides a framework for a series of 19 papers published by the author in a study of transport and magnetic resonance in normal and superfluid Fermi liquids. The Boltzmann equation and methods for its solution are discussed. Electron-electron scattering in metals, with particular emphasis on alkali metals, is considered. Transport in a normal uncharged Fermi liquid such as pure 3 He at temperatures well below its degeneracy temperature of approximately 1 K or mixtures of 3 He in 4 He with degeneracy temperatures ranging typically from 100 to 200 mk is discussed with emphasis on comparison with experiments with the aim of testing models of the particle-particle scattering amplitude. Transport and magnetic resonance in superfluid 3 He is considered. The phenomenological treatment of relaxation is reviewed and the magnitude of the phenomenlogical relaxation time close to Tsub(c) is derived for the case of longitudinal resonance. Comments are made on non-linear magnetic resonance and textures and spin waves. (B.R.H.)

  18. Design of a magnetic braking system

    International Nuclear Information System (INIS)

    Jou, M.; Shiau, J.-K.; Sun, C.-C.

    2006-01-01

    A non-contact method, using magnetic drag force principle, was proposed to design the braking systems to improve the shortcomings of the conventional braking systems. The extensive literature detailing all aspects of the magnetic braking is briefly reviewed, however little of this refers specifically to upright magnetic braking system, which is useful for industries. One of the major issues to design upright magnetic system is to find out the magnetic flux. The changing magnetic flux induces eddy currents in the conductor. These currents dissipate energy in the conductor and generate drag force to slow down the motion. Therefore, a finite element model is developed to analyze the phenomena of magnetic flux density when air gap and materials of track are varied. The verification shows the predicted magnetic flux is within acceptable range with the measured value. The results will facilitate the design of magnetic braking systems

  19. Effectiveness of work zone intelligent transportation systems.

    Science.gov (United States)

    2013-12-01

    In the last decade, Intelligent Transportation Systems (ITS) have increasingly been deployed in work zones by state departments of transportation. Also known as smart work zone systems they improve traffic operations and safety by providing real-time...

  20. Turbulence, transport and confinement: from tokamaks to star magnetism

    International Nuclear Information System (INIS)

    Strugarek, Antoine

    2012-01-01

    This thesis is part of the general study of self-organization in hot and magnetized plasmas. We focus our work on two specific objects: stars and tokamaks. We use first principle numerical simulations to study turbulence, transport and confinement in these plasmas. The first part of this thesis introduces the main characteristics of stellar and tokamak plasmas. The reasons for studying them together are properly detailed. The second part is focused on stellar aspects. We study the interactions between the 3D turbulent motions in the solar convection zone with an internal magnetic field in the tachocline (the transition region between the instable and stable zones in the Sun). The tachocline is a very thin layer (less than five percent of the solar radius) that acts as a transport barrier of angular momentum. We show that such an internal magnetic field is not likely to explain the observed thickness of the tachocline and we give some insights on how to find alternative mechanisms to constrain it. We also explore the effect of the environment of star on its structure. We develop a methodology to study the influence of stellar wind and of the magnetic coupling of a star with its orbiting planets. We use the same methodology to analyse the magnetic interaction between a stellar wind and a planetary magnetosphere that acts as a transport barrier of matter. Then, the third part is dedicated to fusion oriented research. We present a numerical investigation on the experimental mechanisms that lead to the development of transport barriers in the plasma. These barriers are particularly important for the design of high performance fusion devices. The creation of transport barriers is obtained in turbulent first principle simulations for the very first time. The collaboration between the two scientific teams lead to the results presented in the fourth part of this thesis. An original spectral method is developed to analyse the saturation of stellar convective dynamos and of

  1. Electronics and instrumentation for the SST-1 superconducting magnet system

    International Nuclear Information System (INIS)

    Khristi, Yohan; Pradhan, Subrata; Varmora, Pankaj; Banaudha, Moni; Praghi, Bhadresh R.; Prasad, Upendra

    2015-01-01

    Steady State Superconducting Tokamak-1 (SST-1) at Institute for Plasma Research (IPR), India is now in operation phase. The SST-1 magnet system consists of sixteen superconducting (SC), D-shaped Toroidal Field (TF) coils and nine superconducting Poloidal Field (PF) coils together with a pair of resistive PF coils, inside the vacuum vessel of SST-1. The magnets were cooled down to 4.5 K using either supercritical or two-phase helium, after which they were charged up to 10 kA of transport current. Precise quench detection system, cryogenic temperature, magnetic field, strain, displacement, flow and pressure measurements in the Superconducting (SC) magnet were mandatory. The Quench detection electronics required to protect the SC magnets from the magnet Quench therefore system must be reliable and prompt to detect the quench from the harsh tokamak environment and high magnetic field interference. A ∼200 channels of the quench detection system for the TF magnet are working satisfactorily with its design criteria. Over ∼150 channels Temperature measurement system was implemented for the several locations in the magnet and hydraulic circuits with required accuracy of 0.1K at bellow 30K cryogenic temperature. Whereas the field, strain and displacement measurements were carried out at few predefined locations on the magnet. More than 55 channels of Flow and pressure measurements are carried out to know the cooling condition and the mass flow of the liquid helium (LHe) coolant for the SC Magnet system. This report identifies the different in-house modular signal conditioning electronics and instrumentation systems, calibration at different levels and the outcomes for the SST-1 TF magnet system. (author)

  2. Electronic and transport properties of noncollinear magnetic monatomic Mn chains: Fano resonances in the superlattice of noncollinear magnetic barriers and magnetic anisotropic bands

    International Nuclear Information System (INIS)

    Dai, C.J.; Yan, X.H.; Xiao, Y.; Guo, Y.D.

    2015-01-01

    By means of the density functional theory combined with non-equilibrium Green's function method, ballistic transport properties of one-dimensional noncollinear magnetic monatomic chains were investigated using the single-atomic Mn chains as a model system. Fano resonances are found to exist in the monatomic Mn chains with spin-spiral structure. Furthermore, in the monatomic Mn chains with magnetic soliton lattice, Fano resonances are enhanced and cause the conductance splitting in the transmission spectra. The Fano resonances in the noncollinear magnetic single-atomic Mn chains are arising from the coupling of the localized d-states and the extended states of the quantum channels. By constructing a theoretical model and calculating its conductance, it is found that the phenomena of Fano resonances and the accompanying conductance splitting exist universally in the superlattice of one-dimensional noncollinear magnetic barriers, due to the interference of the incident waves and reflected waves by the interfaces between the neighboring barriers. Moreover, the band structures of the ferromagnetic and spin-spiral monatomic Mn chains exhibit a strong dependence on the spatial arrangement of the magnetic moments of Mn atoms when spin–orbit coupling is considered. - Highlights: • Transport properties of noncollinear magnetic monatomic Mn chains are studied. • Fano resonances are found in the noncollinear magnetic monatomic Mn chains. • Magnetic soliton lattice leads to conductance splitting in the transmission curve. • Fano resonances exist in the superlattice of noncollinear magnetic barriers. • Effect of SOC on the band structure of FM and spin-spiral Mn chains are studied

  3. ADVANCES IN ZERO ENERGY TRANSPORTATION SYSTEMS

    OpenAIRE

    Ahmad, Othman

    2017-01-01

    Hyperloop mass transportation systems are activelydeveloped at the moment. They represent the forefront development of the ZeroEnergy Transportation systems where air drag is minimized by travelling in avacuum and friction is reduced by non-contact bearings. Hyperloop supportersare confident that the cost of their transportation systems would be lowcompared to existing transportation systems because of the low loss andtherefore low energy consumption as well as other cost-saving techniquesdoc...

  4. Investigation of magnetic drift on transport of plasma across magnetic field

    International Nuclear Information System (INIS)

    Hazarika, Parismita; Chakraborty, Monojit; Das, Bidyut; Bandyopadhyay, Mainak

    2015-01-01

    When a metallic body is inserted inside plasma chamber it is always associated with sheath which depends on plasma and wall condition. The effect of sheath formed in the magnetic drift and magnetic field direction on cross field plasma transport has been investigated in a double Plasma device (DPD). The drifts exist inside the chamber in the transverse magnetic field (TMF) region in a direction perpendicular to both magnetic field direction and axis of the DPD chamber. The sheath are formed in the magnetic drift direction in the experimental chamber is due to the insertion of two metallic plates in these directions and in the magnetic field direction sheath is formed at the surface of the TMF channels. These metallic plates are inserted in order to obstruct the magnetic drift so that we can minimised the loss of plasma along drift direction and density in the target region is expected to increase due to the obstruction. It ultimately improves the negative ion formation parameters. The formation of sheath in the transverse magnetic field region is studied by applying electric field both parallel and antiparallel to drift direction. Data are acquired by Langmuir probe in source and target region of our chamber. (author)

  5. Magnetic and transport properties of Fe-based nanocrystalline materials

    Science.gov (United States)

    Barandiarán, J. M.

    1994-01-01

    Fe-rich amorphous alloys containing late transition metals like Nb, V, Zr,..., sometimes with the addition of Cu, can crystallize in ultrafine grains of a crystalline phase, a few nanometers in diameter, embedded in a disordered matrix. In such state they have shown excellent soft magnetic properties for technical applications, rising the interest for deep studies. In this paper, recent work on some Fe-Nb and Fe-Zr based alloys both in amorphous state and after several degrees of nanocrystallization is presented. The nanocrystallization process has been achieved by conventional heat treatments (about 1 h at temperatures around 400-500 °C in a controlled atmosphere furnance) as well as by Joule heating using an electrical current flowing through the sample. Magnetic measurements, electrical resistivity, x-rays diffraction and 57Fe Mössbauer spectroscopy were used in the study of the crystalline phases appearing after the thermal treatments. The basic magnetic and transport properties of the nanocrystals do not differ appreciably from their bulk values. The magnetic anisotropy, however, is very sensitive to grain size and to the intergranular magnetic coupling. The effect of such coupling is deduced from the coercivity changes at the Curie Temperature of the amorphous matrix remaining after nanocrystallization.

  6. Thermodynamics and CP-odd transport in holographic QCD with finite magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Drwenski, Tara; Gürsoy, Umut [Institute for Theoretical Physics, Utrecht University,Leuvenlaan 4, 3584 CE Utrecht (Netherlands); Iatrakis, Ioannis [Department of Physics and Astronomy, Stony Brook University,Stony Brook, New York 11794-3800 (United States)

    2016-12-13

    We consider a bottom-up holographic model of QCD at finite temperature T and magnetic field B, and study dependence of thermodynamics and CP-odd transport on these variables. As the magnetic field couples to the flavor sector only, one should take the Veneziano limit where the number of flavors and colors are large while their ratio is kept fixed. We investigate the corresponding holographic background in the approximation where the ratio of flavors to colors is finite but small. We demonstrate that B-dependence of the entropy of QCD is in qualitative agreement with the recent lattice studies. Finally we study the CP-odd transport properties of this system. In particular, we determine the Chern-Simons decay rate at finite B and T, that is an important ingredient in the Chiral Magnetic Effect.

  7. Cosmic-Ray Transport in Heliospheric Magnetic Structures. II. Modeling Particle Transport through Corotating Interaction Regions

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Andreas [Université Libre de Bruxelles, Service de Physique Statistique et des Plasmas, CP 231, B-1050 Brussels (Belgium); Wiengarten, Tobias; Fichtner, Horst [Institut für Theoretische Physik IV, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Effenberger, Frederic [Department of Physics and KIPAC, Stanford University, Stanford, CA 94305 (United States); Kühl, Patrick; Heber, Bernd [Institut für Experimentelle und Angewandte Physik, Christian-Albrecht-Universität zu Kiel, D-24098 Kiel (Germany); Raath, Jan-Louis; Potgieter, Marius S. [Centre for Space Research, North-West University, 2520 Potchefstroom (South Africa)

    2017-03-01

    The transport of cosmic rays (CRs) in the heliosphere is determined by the properties of the solar wind plasma. The heliospheric plasma environment has been probed by spacecraft for decades and provides a unique opportunity for testing transport theories. Of particular interest for the three-dimensional (3D) heliospheric CR transport are structures such as corotating interaction regions (CIRs), which, due to the enhancement of the magnetic field strength and magnetic fluctuations within and due to the associated shocks as well as stream interfaces, do influence the CR diffusion and drift. In a three-fold series of papers, we investigate these effects by modeling inner-heliospheric solar wind conditions with the numerical magnetohydrodynamic (MHD) framework Cronos (Wiengarten et al., referred as Paper I), and the results serve as input to a transport code employing a stochastic differential equation approach (this paper). While, in Paper I, we presented results from 3D simulations with Cronos, the MHD output is now taken as an input to the CR transport modeling. We discuss the diffusion and drift behavior of Galactic cosmic rays using the example of different theories, and study the effects of CIRs on these transport processes. In particular, we point out the wide range of possible particle fluxes at a given point in space resulting from these different theories. The restriction of this variety by fitting the numerical results to spacecraft data will be the subject of the third paper of this series.

  8. TRANSPORT: a computer program for designing charged particle beam transport systems

    International Nuclear Information System (INIS)

    Brown, K.L.; Rothacker, F.; Carey, D.C.; Iselin, C.

    1977-05-01

    TRANSPORT is a first- and second-order matrix multiplication computer program intended for the design of static-magnetic beam transport systems. It has been in existence in various evolutionary versions since 1963. The present version, described in the manual given, includes both first- and second-order fitting capabilities. TRANSPORT will step through the beam line, element by element, calculating the properties of the beam or other quantities, described below, where requested. Therefore one of the first elements is a specification of the phase space region occupied by the beam entering the system. Magnets and intervening spaces and other elements then follow in the sequence in which they occur in the beam line. Specifications of calculations to be done or of configurations other than normal are placed in the same sequence, at the point where their effect is to be made

  9. Tornado-like transport in a magnetized plasma

    Science.gov (United States)

    Poulos, Matthew; van Compernolle, Bart; Morales, George

    2017-10-01

    Recent heat transport experiments conducted in the LAPD device at UCLA in which avalanche events have been previously documented have also lead to the identification of a new tornado-like transport phenomenon. These tornados occur much earlier than the avalanches events, essentially in the interval following the application of the bias voltage that causes the injection of an electron beam from a ring-shaped LaB6 cathode into the afterglow of a cold, magnetized plasma. The tornados exhibit a low-frequency (4 kHz) (much lower than drift-waves), spiraling, global eigenmode whose transient behavior is responsible for significant radial transport well outside the heated region. Detailed experimental observations are compared with a Braginskii transport code that includes the effects of ExB convection induced by the spiraling global eigenmode. New insights are gained into the necessary modifications of classical transport to accurately simulate the spiraling effects and the possible interaction with avalanches. This work is supported by the NSF/DOE partnership in basic plasma science and engineering, Grant Number 1619505, and is performed at the Basic Plasma Science Facility, sponsored jointly by DOE and NSF. Sponsored by DOE/NSF at BaPSF and NSF 1619505.

  10. Temperature expansions for magnetic systems

    International Nuclear Information System (INIS)

    Cangemi, D.; Dunne, G.

    1996-01-01

    We derive finite temperature expansions for relativistic fermion systems in the presence of background magnetic fields, and with nonzero chemical potential. We use the imaginary-time formalism for the finite temperature effects, the proper-time method for the background field effects, and zeta function regularization for developing the expansions. We emphasize the essential difference between even and odd dimensions, focusing on 2+1 and 3+1 dimensions. We concentrate on the high temperature limit, but we also discuss the T=0 limit with nonzero chemical potential. Copyright copyright 1996 Academic Press, Inc

  11. Instabilities, turbulence and transport in a magnetized plasma

    International Nuclear Information System (INIS)

    Garbet, X.

    2001-06-01

    The purpose of this work is to introduce the main processes that occur in a magnetized plasma. During the last 2 decades, the understanding of turbulence has made great progress but analytical formulas and simulations are far to produce reliable predictions. The values of transport coefficients in a tokamak plasma exceed by far those predicted by the theory of collisional transport. This phenomenon is called abnormal transport and might be due to plasma fluctuations. An estimation of turbulent fluxes derived from the levels of fluctuations, is proposed. A flow description of plasma allows the understanding of most micro-instabilities. The ballooning representation deals with instabilities in a toric geometry. 3 factors play an important role to stabilize plasmas: density pinch, magnetic shear and speed shear. The flow model of plasma gives an erroneous value for the stability threshold, this is due to a bad description of the resonant interaction between wave and particle. As for dynamics, flow models can be improved by adding dissipative terms so that the linear response nears the kinetic response. The kinetic approach is more accurate but is complex because of the great number of dimensions involved. (A.C.)

  12. Modified BEM calculations on magnetic systems

    International Nuclear Information System (INIS)

    Christoph, V.; Toepfer, J.

    1998-01-01

    A modified boundary element method is presented for the calculation of 3d magnetic fields of magnetic systems including any permanent and soft magnetic materials as well as current distributions. Using an automatic mesh generation inside the magnetic bodies the method is especially suited for the investigation of open air gap systems. The influence of eddy currents on the magnetisation process can be investigated. For illustration, the flux concentration by pole pieces and the generation of magnetic stripe structures in magnetic thick films by pulse fields are considered. (orig.)

  13. TMX magnet system, present and future

    International Nuclear Information System (INIS)

    Wong, R.L.; Pedrotti, L.R.; Leavitt, G.A.; Waugh, A.F.; Chargin, A.K.; Calderon, M.O.

    1979-01-01

    The magnetic field design and the mechanical design of the TMX magnet system were previously reported by Chen and Hinkle. This paper is a summary of the work that has been accomplished in the two years since then

  14. Magnetic nanofluids and magnetic composite fluids in rotating seal systems

    International Nuclear Information System (INIS)

    Borbath, T; Borbath, I; Boros, T; Bica, D; Vekas, L; Potencz, I

    2010-01-01

    Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.

  15. Road Transportable Analytical Laboratory system

    International Nuclear Information System (INIS)

    Finger, S.M.; Keith, V.F.; Spertzel, R.O.; De Avila, J.C.; O'Donnell, M.; Vann, R.L.

    1993-09-01

    This developmental effort clearly shows that a Road Transportable Analytical Laboratory System is a worthwhile and achievable goal. The RTAL is designed to fully analyze (radioanalytes, and organic and inorganic chemical analytes) 20 samples per day at the highest levels of quality assurance and quality control. It dramatically reduces the turnaround time for environmental sample analysis from 45 days (at a central commercial laboratory) to 1 day. At the same time each RTAL system will save the DOE over $12 million per year in sample analysis costs compared to the costs at a central commercial laboratory. If RTAL systems were used at the eight largest DOE facilities (at Hanford, Savannah River, Fernald, Oak Ridge, Idaho, Rocky Flats, Los Alamos, and the Nevada Test Site), the annual savings would be $96,589,000. The DOE's internal study of sample analysis needs projects 130,000 environmental samples requiring analysis in FY 1994, clearly supporting the need for the RTAL system. The cost and time savings achievable with the RTAL system will accelerate and improve the efficiency of cleanup and remediation operations throughout the DOE complex

  16. Scaling laws for aberrations in magnetic quadrupole lens systems

    International Nuclear Information System (INIS)

    Moses, R.W.; Heighway, E.A.; Christian, R.S.; Dragt, A.J.

    1987-01-01

    A comparison has been made of the third-order (spherical) abberrations in magnetic quadrupole lenses for use in conventional charged particle beam transport systems. An analytical description of the abberrations is presented and this is compared with the results of high order numerical integration. The dependence of the aberration strength on the system geometry and f number is given and a comparison of doublet and triplet systems made. The reduction of the aberrations in both doublet and triplet systems using embedded magnetic octupole lenses is also discussed and analytical predictions are given

  17. Urban Transportation Planning Short Course: Evaluation of Alternative Transportation Systems.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC.

    This urban transportation pamphlet delves into the roles of policy groups and technical staffs in evaluating alternative transportation plans, evaluation criteria, systems to evaluate, and evaluation procedures. The introduction admits the importance of subjective, but informed, judgment as an effective tool in weighing alternative transportation…

  18. A study on an object transport system using ultrasonic wave excitation

    International Nuclear Information System (INIS)

    Jeong, Sang Hwa; Kim, Gwang Ho; Choi, Suk Bong; Park, Jun Ho; Cha, Kyoung Rae

    2007-01-01

    The development of information and telecommunication industries leads to the development of semiconductor and optical industries. In recent years, the demand of optical components is growing due to the demand of faster network. On the other hand, conventional transport systems are not adequate for transporting precision optical components and semiconductors. Because the conveyor belt can damage precision optical components with contact force and a magnetic system would destroy the inner structure of semiconductor with magnetic field, a new system for transporting optical components and semiconductors is required. One of the alternatives to the existing systems is a transport system using ultrasonic wave excitation since it can transport precision components such as semiconductors and optical components without damage. In this paper, a transport system using 2-mode ultrasonic wave excitation was developed for transporting optical components and semiconductor, and its performance was evaluated. The relationship between transporting characteristics and flexural beam shapes were evaluated

  19. Performances of the HL (Hyperloop) transport system

    NARCIS (Netherlands)

    van Goeverden, C.D.; Milakis, D.; Janic, M.; Konings, J.W.; Cools, M.; Limbourg, S.

    2017-01-01

    This paper deals with an analysis of performances of the HL (Hyperloop) transport system considered as an advanced transport alternative to the existing APT (Air Passenger Transport) and HSR (High Speed Rail) systems. The considered performances are operational, financial, social and environmental.

  20. Radioisotope Thermoelectric Generator Transport Trailer System

    International Nuclear Information System (INIS)

    Ard, K.E.; King, D.A.; Leigh, H.; Satoh, J.A.

    1994-01-01

    The Radioisotope Thermoelectric Generator (RTG) Transportation System, designated as System 100, comprises four major systems. The four major systems are designated as the Packaging System (System 120), Trailer System (System 140), Operations and Ancillary Equipment System system 160), and Shipping and Receiving Facility Transport System (System 180). Packaging System (System 120), including the RTG packaging is licensed (regulatory) hardware; it is certified by the US Department of Energy to be in accordance with Title 10, Code of federal Regulations, Part 71 (10 CFR 71). System 140, System 160, and System 180 are nonlicensed (nonregulatory) hardware

  1. Charge and Spin Transport in Dilute Magnetic Semiconductors. Final report

    International Nuclear Information System (INIS)

    Ullrich, Carsten A.

    2009-01-01

    This proposal to the DOE outlines a three-year plan of research in theoretical and computational condensed-matter physics, with the aim of developing a microscopic theory for charge and spin dynamics in disordered materials with magnetic impurities. Important representatives of this class of materials are the dilute magnetic semiconductors (DMS), which have attracted great attention as a promising basis for spintronics devices. There is an intense experimental effort underway to study the transport properties of ferromagnetic DMS such as (Ga,Mn)As, and a number of interesting features have emerged: negative magnetoresistance, anomalous Hall effect, non-Drude dynamical conductivity, and resistivity maxima at the Curie temperature. Available theories have been able to account for some of these features, but at present we are still far away from a systematic microscopic understanding of transport in DMS. We propose to address this challenge by developing a theory of charge and spin dynamics based on a combination of the memory-function formalism and time-dependent density functional theory. This approach will be capable of dealing with two important issues: (a) the strong degree of correlated disorder in DMS, close to the localization transition (which invalidates the usual relaxation-time approximation to the Boltzmann equation), (b) the essentially unknown role of dynamical many-body effects such as spin Coulomb drag. We will calculate static and dynamical conductivities in DMS as functions of magnetic order and carrier density, which will advance our understanding of recent transport and infrared absorption measurements. Furthermore, we will study collective plasmon excitations in DMS (3D, 2D and quantum wells), whose linewidths could constitute a new experimental probe of the correlation of disorder, many-body effects and charge and spin dynamics in these materials.

  2. Fifth-order aberrations in magnetic quadrupole-octupole systems

    International Nuclear Information System (INIS)

    Ling, K.M.

    1990-01-01

    Explicit integral expressions are given for the fifth-order geometrical aberration coefficients in rectilinear magnetic quadrupole-octupole systems used for the transport of nonrelativistic charged particle beams. The numerical values of the fifth-order geometrical aberration coefficients for a rare earth cobalt (REC) quadrupole doublet are given as an example. 26 refs., 5 figs., 4 tabs

  3. Study of magnetization switching in coupled magnetic nanostructured systems

    Science.gov (United States)

    Radu, Cosmin

    A study of magnetization dynamics experiments in nanostructured materials using the rf susceptibility tunnel diode oscillator (TDO) method is presented along with a extensive theoretical analysis. An original, computer controlled experimental setup that measures the change in susceptibility with the variation in external magnetic field and sample temperature was constructed. The TDO-based experiment design and construction is explained in detail, showing all the elements of originality. This experimental technique has proven reliable for characterizing samples with uncoupled magnetic structure and various magnetic anisotropies like: CrO2, FeCo/IrMn and Co/SiO2 thin films. The TDO was subsequently used to explore the magnetization switching in coupled magnetic systems, like synthetic antiferromagnet (SAF) structures. Magnetoresistive random access memory (MRAM) is an important example of devices where the use of SAF structure is essential. To support the understanding of the SAF magnetic behavior, its configuration and application are reviewed and more details are provided in an appendix. Current problems in increasing the scalability and decreasing the error rate of MRAM devices are closely connected to the switching properties of the SAF structures. Several theoretical studies that were devoted to the understanding of the concepts of SAF critical curve are reviewed. As one can notice, there was no experimental determination of SAF critical curve, due to the difficulties in characterizing a magnetic coupled structure. Depending of the coupling strength between the two ferromagnetic layers, on the SAF critical curve one distinguishes several new features, inexistent in the case of uncoupled systems. Knowing the configuration of the SAF critical curve is of great importance in order to control its switching characteristics. For the first time a method of experimentally recording the critical curve for SAF is proposed in this work. In order to overcome technological

  4. Transport regimes spanning magnetization-coupling phase space

    Science.gov (United States)

    Baalrud, Scott D.; Daligault, Jérôme

    2017-10-01

    The manner in which transport properties vary over the entire parameter-space of coupling and magnetization strength is explored. Four regimes are identified based on the relative size of the gyroradius compared to other fundamental length scales: the collision mean free path, Debye length, distance of closest approach, and interparticle spacing. Molecular dynamics simulations of self-diffusion and temperature anisotropy relaxation spanning the parameter space are found to agree well with the predicted boundaries. Comparison with existing theories reveals regimes where they succeed, where they fail, and where no theory has yet been developed.

  5. Spin-Swapping Transport and Torques in Ultrathin Magnetic Bilayers

    KAUST Repository

    Saidaoui, Hamed Ben Mohamed; Manchon, Aurelien

    2016-01-01

    Planar spin transport in disordered ultrathin magnetic bilayers comprising a ferromagnet and a normal metal (typically used for spin pumping, spin Seebeck and spin-orbit torque experiments) is investigated theoretically. Using a tight-binding model that puts the extrinsic spin Hall effect and spin swapping on equal footing, we show that the nature of spin-orbit coupled transport dramatically depends on the ratio between the layer thickness d and the mean free path λ. While the spin Hall effect dominates in the diffusive limit (d≫λ), spin swapping dominates in the Knudsen regime (d≲λ). A remarkable consequence is that spin swapping induces a substantial fieldlike torque in the Knudsen regime.

  6. Spin-Swapping Transport and Torques in Ultrathin Magnetic Bilayers

    KAUST Repository

    Saidaoui, Hamed Ben Mohamed

    2016-07-12

    Planar spin transport in disordered ultrathin magnetic bilayers comprising a ferromagnet and a normal metal (typically used for spin pumping, spin Seebeck and spin-orbit torque experiments) is investigated theoretically. Using a tight-binding model that puts the extrinsic spin Hall effect and spin swapping on equal footing, we show that the nature of spin-orbit coupled transport dramatically depends on the ratio between the layer thickness d and the mean free path λ. While the spin Hall effect dominates in the diffusive limit (d≫λ), spin swapping dominates in the Knudsen regime (d≲λ). A remarkable consequence is that spin swapping induces a substantial fieldlike torque in the Knudsen regime.

  7. SDDOT transportation systems management & operations program plan.

    Science.gov (United States)

    2016-06-01

    The objective of this project is the development of a comprehensive Transportation Systems Management and : Operations (TSM&O) Program Plan for the South Dakota Department of Transportation. This plan guides : business planning and strategic decision...

  8. A model for the nonlocal transport and the associated distribution function deformation in magnetized laser-plasmas

    Science.gov (United States)

    Nicolaï, Ph.; Feugeas, J.-L.; Schurtz, G.

    2006-06-01

    We present a model of nonlocal transport for multidimensional radiation magneto hydrodynamic codes. In laser produced plasmas, it is now believed that the heat transfert can be strongly modified by the nonlocal nature of the electron conduction. Nevertheless other mechanisms as self generated magnetic fields may affect heat transport too. The model described in this work aims at extending the formula of G. Schurtz, Ph. Nicolaï and M. Busquet [1] to magnetized plasmas. A system of nonlocal equations is derived from kinetic equations with self-consistent electric and magnetic fields. These equations are analyzed and applied to a physical problem in order to demonstrate the main features of the model.

  9. Application of magnetic liposomes for magnetically guided transport of muscle relaxants and anti-cancer photodynamic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Anatoly A.; Filippov, Victor I.; Alyautdin, Renat N.; Torshina, N.L.; Kuznetsov, O.A. E-mail: oleg@louisiana.edu

    2001-07-01

    Magnetic liposomes containing submicron-sized ferromagnetic particles were prepared encapsulating the muscle relaxant drugs, diadony or diperony, for local anesthesia. Alternatively, metal phthalocyanines (Photosense or Teraphthal), sensitizers for photodynamic or catalytic cancer therapy were loaded into the magnetic liposomes. Animal trials demonstrated successful magnetically guided transport of the drug-loaded liposomes.

  10. Application of magnetic liposomes for magnetically guided transport of muscle relaxants and anti-cancer photodynamic drugs

    International Nuclear Information System (INIS)

    Kuznetsov, Anatoly A.; Filippov, Victor I.; Alyautdin, Renat N.; Torshina, N.L.; Kuznetsov, O.A.

    2001-01-01

    Magnetic liposomes containing submicron-sized ferromagnetic particles were prepared encapsulating the muscle relaxant drugs, diadony or diperony, for local anesthesia. Alternatively, metal phthalocyanines (Photosense or Teraphthal), sensitizers for photodynamic or catalytic cancer therapy were loaded into the magnetic liposomes. Animal trials demonstrated successful magnetically guided transport of the drug-loaded liposomes

  11. Intelligent transportation systems problems and perspectives

    CERN Document Server

    Pamuła, Wiesław

    2016-01-01

    This book presents a discussion of problems encountered in the deployment of Intelligent Transport Systems (ITS). It puts emphasis on the early tasks of designing and proofing the concept of integration of technologies in Intelligent Transport Systems. In its first part the book concentrates on the design problems of urban ITS. The second part of the book features case studies representative for the different modes of transport. These are freight transport, rail transport and aerospace transport encompassing also space stations. The book provides ideas for deployment which may be developed by scientists and engineers engaged in the design of Intelligent Transport Systems. It can also be used in the training of specialists, students and post-graduate students in universities and transport high schools.    .

  12. How to probe transverse magnetic anisotropy of a single-molecule magnet by electronic transport?

    Science.gov (United States)

    Misiorny, M.; Burzuri, E.; Gaudenzi, R.; Park, K.; Leijnse, M.; Wegewijs, M.; Paaske, J.; Cornia, A.; van der Zant, H.

    We propose an approach for in-situ determination of the transverse magnetic anisotropy (TMA) of an individual molecule by electronic transport measurements, see Phys. Rev. B 91, 035442 (2015). We study a Fe4 single-molecule magnet (SMM) captured in a gateable junction, a unique tool for addressing the spin in different redox states of a molecule. We show that, due to mixing of the spin eigenstates of the SMM, the TMA significantly manifests itself in transport. We predict and experimentally observe the pronounced intensity modulation of the Coulomb peak amplitude with the magnetic field in the linear-response transport regime, from which the TMA parameter E can be estimated. Importantly, the method proposed here does not rely on the small induced tunnelling effects and, hence, works well at temperatures and electron tunnel broadenings by far exceeding the tunnel splittings and even E itself. We deduce that the TMA for a single Fe4 molecule captured in a junction is substantially larger than the bulk value. Work supported by the Polish Ministry of Science and Education as `Iuventus Plus' project (IP2014 030973) in years 2015-2016.

  13. Field Mapping System for Solenoid Magnet

    Science.gov (United States)

    Park, K. H.; Jung, Y. K.; Kim, D. E.; Lee, H. G.; Park, S. J.; Chung, C. W.; Kang, B. K.

    2007-01-01

    A three-dimensional Hall probe mapping system for measuring the solenoid magnet of PLS photo-cathode RF e-gun has been developed. It can map the solenoid field either in Cartesian or in cylindrical coordinate system with a measurement reproducibility better than 5 × 10-5 T. The system has three axis motors: one for the azimuthal direction and the other two for the x and z direction. This architecture makes the measuring system simple in fabrication. The magnetic center was calculated using the measured axial component of magnetic field Bz in Cartesian coordinate system because the accuracy of magnetic axis measurement could be improved significantly by using Bz, instead of the radial component of magnetic field Br. This paper describes the measurement system and summarizes the measurement results for the solenoid magnetic of PLS photo-cathode RF e-gun.

  14. New, coupling loss induced, quench protection system for superconducting accelerator magnets

    NARCIS (Netherlands)

    Ravaioli, Emanuele; Datskov, V.I.; Giloux, C.; Kirby, G.; ten Kate, Herman H.J.; Verweij, A.P.

    2014-01-01

    A new and promising method for the protection of superconducting high-field magnets is developed and tested on the so-called MQXC quadrupole magnet in the CERN magnet test facility. The method relies on a capacitive discharge system inducing during a few periods an oscillation of the transport

  15. Quantum transport in topological semimetals under magnetic fields

    Science.gov (United States)

    Lu, Hai-Zhou; Shen, Shun-Qing

    2017-06-01

    Topological semimetals are three-dimensional topological states of matter, in which the conduction and valence bands touch at a finite number of points, i.e., the Weyl nodes. Topological semimetals host paired monopoles and antimonopoles of Berry curvature at the Weyl nodes and topologically protected Fermi arcs at certain surfaces. We review our recent works on quantum transport in topological semimetals, according to the strength of the magnetic field. At weak magnetic fields, there are competitions between the positive magnetoresistivity induced by the weak anti-localization effect and negative magnetoresistivity related to the nontrivial Berry curvature. We propose a fitting formula for the magnetoconductivity of the weak anti-localization. We expect that the weak localization may be induced by inter-valley effects and interaction effect, and occur in double-Weyl semimetals. For the negative magnetoresistance induced by the nontrivial Berry curvature in topological semimetals, we show the dependence of the negative magnetoresistance on the carrier density. At strong magnetic fields, specifically, in the quantum limit, the magnetoconductivity depends on the type and range of the scattering potential of disorder. The high-field positive magnetoconductivity may not be a compelling signature of the chiral anomaly. For long-range Gaussian scattering potential and half filling, the magnetoconductivity can be linear in the quantum limit. A minimal conductivity is found at the Weyl nodes although the density of states vanishes there.

  16. Transport of energetic ions by low-n magnetic perturbations

    International Nuclear Information System (INIS)

    Mynick, H.E.

    1992-10-01

    The stochastic transport of MeV ions induced by low-n magnetic perturbations is studied, focussing chiefly on the stochastic mechanism operative for passing particles in low frequency perturbations. Beginning with a single-harmonic form for the perturbing field, it iii first shown numerically and analytically that the stochastic threshold of energetic particles can be much lower than that of the magnetic field, contrary to earlier expectations, so that MHD perturbations could cause appreciable loss of energetic ions without destroying the bulk confinement. The analytic theory is then extended in a number of directions, to darity the relation of the present stochaistic mechanism to instances already found, to allow for more complex perturbations, and to consider the more general relationship between the stochasticity of magnetic fields, and that of particles of differing energies (and pitch angles) moving in those fields. It is shown that the stochastic threshold is in general a nonmonotonic function of energy, whose form can to some extent be tailored to achieve desired goals (e.g., burn control or ash removal) by a judicious choice of the perturbation. Illustrative perturbations are exhibited which are stochastic for low but not for high-energy ions, for high but not for low-energy ions, and for intermediate-energy ions, but not for low or high energy. The second possibility is the behavior needed for burn control; the third provides a possible mechanism for ash removal

  17. Studies of quenched disorder in La{sub 0.7}Ca{sub 0.3}MnO{sub 3}-type CMR manganite system from magnetic, transport and positron annihilation spectroscopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, S. [Department of Physics, Taki Government College, Taki 743429 (India); Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Sarkar, A. [Department of Physics, Bangabasi Morning College, 19 Rajkumar Chakraborty Sarani, Kolkata 700009 (India); Pal, Sudipta [Department of Physics, Krishnagar Womens College, Krishnagar 741101 (India); Kulkarni, S.D. [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008 (India); Joy, P.A. [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008 (India); Chaudhuri, B.K. [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)]. E-mail: sspbkc@rediffmail.com

    2007-08-01

    The effects of quenched disorder on the structural, transport and magnetic properties of the La{sub 0.7}Ca{sub 0.3}MnO{sub 3}-type colossal magnetoresistive (CMR) sample have been reported. Temperature-dependent resistivity and magnetization data of the quenched sample revealed interesting changes from those of the usual slow-cooled sample. This is attributed to the defects created in the quenched sample and confirmed from the X-ray diffraction (XRD) and positron annihilation spectroscopic studies.

  18. Transport of Internetwork Magnetic Flux Elements in the Solar Photosphere

    Science.gov (United States)

    Agrawal, Piyush; Rast, Mark P.; Gošić, Milan; Bellot Rubio, Luis R.; Rempel, Matthias

    2018-02-01

    The motions of small-scale magnetic flux elements in the solar photosphere can provide some measure of the Lagrangian properties of the convective flow. Measurements of these motions have been critical in estimating the turbulent diffusion coefficient in flux-transport dynamo models and in determining the Alfvén wave excitation spectrum for coronal heating models. We examine the motions of internetwork flux elements in Hinode/Narrowband Filter Imager magnetograms and study the scaling of their mean squared displacement and the shape of their displacement probability distribution as a function of time. We find that the mean squared displacement scales super-diffusively with a slope of about 1.48. Super-diffusive scaling has been observed in other studies for temporal increments as small as 5 s, increments over which ballistic scaling would be expected. Using high-cadence MURaM simulations, we show that the observed super-diffusive scaling at short increments is a consequence of random changes in barycenter positions due to flux evolution. We also find that for long temporal increments, beyond granular lifetimes, the observed displacement distribution deviates from that expected for a diffusive process, evolving from Rayleigh to Gaussian. This change in distribution can be modeled analytically by accounting for supergranular advection along with granular motions. These results complicate the interpretation of magnetic element motions as strictly advective or diffusive on short and long timescales and suggest that measurements of magnetic element motions must be used with caution in turbulent diffusion or wave excitation models. We propose that passive tracer motions in measured photospheric flows may yield more robust transport statistics.

  19. Transport, Thermal, and Magnetic Properties of YbNi3X9 (X = Al, Ga): A Newly Synthesized Yb-Based Kondo Lattice System

    Science.gov (United States)

    Yamashita, Tetsuro; Miyazaki, Ryoichi; Aoki, Yuji; Ohara, Shigeo

    2012-03-01

    We have succeeded in synthesizing a new Yb-based Kondo lattice system, YbNi3X9 (X = Al, Ga). Our study reveals that YbNi3Al9 shows typical features of a heavy-fermion antiferromagnet with a Néel temperature of TN = 3.4 K. All of the properties reflect a competition between the Kondo effect and the crystalline electric field (CEF) effect. The moderate heavy-fermion state leads to an enhanced Sommerfeld coefficient of 100 mJ/(mol\\cdotK2), even if ordered antiferromagnetically. On the other hand, the isostructural gallide YbNi3Ga9 is an intermediate-valence system with a Kondo temperature of TK = 570 K. A large hybridization scale can overcome the CEF splitting energy, and a moderately heavy Fermi-liquid ground state with high local moment degeneracy should form at low temperatures. Note that the quality of single-crystalline YbNi3X9 is extremely high compared with those of other Yb-based Kondo lattice compounds. We conclude that YbNi3X9 is a suitable system for investigating the electronic structure of Yb-based Kondo lattice systems from a heavy-fermion system with an antiferromagnetically ordered ground state to an intermediate-valence system.

  20. High Temperature Superconducting Magnets with Active Control for Attraction Levitation Transport Applications

    Science.gov (United States)

    Jones, Harry; Jenkins, Richard G.; Goodall, Roger M.; Macleod, Colin; ElAbbar, Abdallah A.; Campbell, Archie M.

    1996-01-01

    A research program, involving 3 British universities, directed at quantifying the controllability of High Temperature Superconducting (HTS) magnets for use in attraction levitation transport systems will be described. The work includes measurement of loss mechanisms for iron cored HTS magnets which need to produce a flux density of approx. 1 tesla in the airgap between the magnet poles and a ferromagnetic rail. This flux density needs to be maintained and this is done by introducing small variations of the magnet current using a feedback loop, at frequencies up to 10 Hz to compensate for load changes, track variation etc. The test magnet assemblies constructed so far will be described and the studies and modelling of designs for a practical levitation demonstrator (using commercially obtained HTS tape) will be discussed with particular emphasis on how the field distribution and its components, e.g., the component vector normal to the broad face of the tape, can radically affect design philosophy compared to the classical electrical engineering approach. Although specifically aimed at levitation transport the controllability data obtained have implications for a much wider range of applications.

  1. Consistency evaluation between EGSnrc and Geant4 charged particle transport in an equilibrium magnetic field.

    Science.gov (United States)

    Yang, Y M; Bednarz, B

    2013-02-21

    Following the proposal by several groups to integrate magnetic resonance imaging (MRI) with radiation therapy, much attention has been afforded to examining the impact of strong (on the order of a Tesla) transverse magnetic fields on photon dose distributions. The effect of the magnetic field on dose distributions must be considered in order to take full advantage of the benefits of real-time intra-fraction imaging. In this investigation, we compared the handling of particle transport in magnetic fields between two Monte Carlo codes, EGSnrc and Geant4, to analyze various aspects of their electromagnetic transport algorithms; both codes are well-benchmarked for medical physics applications in the absence of magnetic fields. A water-air-water slab phantom and a water-lung-water slab phantom were used to highlight dose perturbations near high- and low-density interfaces. We have implemented a method of calculating the Lorentz force in EGSnrc based on theoretical models in literature, and show very good consistency between the two Monte Carlo codes. This investigation further demonstrates the importance of accurate dosimetry for MRI-guided radiation therapy (MRIgRT), and facilitates the integration of a ViewRay MRIgRT system in the University of Wisconsin-Madison's Radiation Oncology Department.

  2. Consistency evaluation between EGSnrc and Geant4 charged particle transport in an equilibrium magnetic field

    International Nuclear Information System (INIS)

    Yang, Y M; Bednarz, B

    2013-01-01

    Following the proposal by several groups to integrate magnetic resonance imaging (MRI) with radiation therapy, much attention has been afforded to examining the impact of strong (on the order of a Tesla) transverse magnetic fields on photon dose distributions. The effect of the magnetic field on dose distributions must be considered in order to take full advantage of the benefits of real-time intra-fraction imaging. In this investigation, we compared the handling of particle transport in magnetic fields between two Monte Carlo codes, EGSnrc and Geant4, to analyze various aspects of their electromagnetic transport algorithms; both codes are well-benchmarked for medical physics applications in the absence of magnetic fields. A water–air–water slab phantom and a water–lung–water slab phantom were used to highlight dose perturbations near high- and low-density interfaces. We have implemented a method of calculating the Lorentz force in EGSnrc based on theoretical models in literature, and show very good consistency between the two Monte Carlo codes. This investigation further demonstrates the importance of accurate dosimetry for MRI-guided radiation therapy (MRIgRT), and facilitates the integration of a ViewRay MRIgRT system in the University of Wisconsin-Madison's Radiation Oncology Department. (note)

  3. High-field superconducting window-frame beam-transport magnets

    International Nuclear Information System (INIS)

    Allinger, J.; Carroll, A.; Danby, G.; DeVito, B.; Jackson, J.; Leonhardt, W.; Prodell, A.; Skarita, J.

    1982-01-01

    The window-frame design for high-field superconducting beam-transport magnets was first applied to two, 2-m-long, 4-T modules of an 8 0 bending magent which has operated for nine years in the primary proton beam line at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). The design of two 1.5-m long, 7.6-cm cold-bore superconducting windowframe magnets, described in this paper, intended for the external proton beam transport system at the AGS incorporated evolutionary changes. These magnets generated a maximum aperture field of 6.8 T with a peak field in the dipole coil of 7.1 T. Measured fields are very accurate and are compared to values calculated using the computer programs LINDA and POISSON. Results of quench-propagation studies demonstrate the excellent thermal stability of the magnets. The magnets quench safely without energy extraction at a maximum current density, J = 130 kA/cm 2 in the superconductor, corresponding to J = 57.6 kA/cm 2 overall the conductor at B = 6.7 T

  4. Evaluation of intelligent transport systems impact on school transport safety

    Directory of Open Access Journals (Sweden)

    Jankowska-Karpa Dagmara

    2017-01-01

    Full Text Available The integrated system of safe transport of children to school using Intelligent Transport Systems was developed and implemented in four locations across Europe under the Safeway2School (SW2S project, funded by the EU. The SW2S system evaluation included speed measurements and an eye-tracking experiment carried out among drivers who used the school bus route, where selected elements of the system were tested. The subject of the evaluation were the following system elements: pedestrian safety system at the bus stop (Intelligent Bus Stop and tags for children, Driver Support System, applications for parents’ and students’ mobile phones, bus stop inventory tool and data server. A new sign designed for buses and bus stops to inform about child transportation/children waiting at the bus stop was added to the system. Training schemes for system users were also provided. The article presents evaluation results of the impact of selected elements of the SW2S system on school transport safety in Poland.

  5. Control of machine functions or transport systems

    International Nuclear Information System (INIS)

    Woodley, M.D.; Lee, M.J.; Jaeger, J.; King, A.S.

    1983-01-01

    A computer code, COMFORT, has been developed at SLAC for on-line calculation of the strengths of magnetic elements in an electron storage ring or transport beam line, subject to first order fitting constraints on the ring or beam line parameters. This code can also be used off-line as an interactive lattice or beam line design tool

  6. Silicon transport under rotating and combined magnetic fields in liquid phase diffusion growth of SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, University of Victoria, Victoria, BC, V8W 3P6 (Canada)

    2010-04-15

    The effect of applied rotating and combined (rotating and static) magnetic fields on silicon transport during the liquid phase diffusion growth of SiGe was experimentally studied. 72-hour growth periods produced some single crystal sections. Single and polycrystalline sections of the processed samples were examined for silicon composition. Results show that the application of a rotating magnetic field enhances silicon transport in the melt. It also has a slight positive effect on flattening the initial growth interface. For comparison, growth experiments were also conducted under combined (rotating and static) magnetic fields. The processed samples revealed that the addition of static field altered the thermal characteristics of the system significantly and led to a complete melt back of the germanium seed. Silicon transport in the melt was also enhanced under combined fields compared with experiments with no magnetic field. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Nonlinear transport of dynamic system phase space

    International Nuclear Information System (INIS)

    Xie Xi; Xia Jiawen

    1993-01-01

    The inverse transform of any order solution of the differential equation of general nonlinear dynamic systems is derived, realizing theoretically the nonlinear transport for the phase space of nonlinear dynamic systems. The result is applicable to general nonlinear dynamic systems, with the transport of accelerator beam phase space as a typical example

  8. Integrated transport and renewable energy systems

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik; Nørgaard, P.

    2008-01-01

    No single technology can solve the problem of ever increasing CO2 emissions from transport. Here, a coherent effort to integrate transport into energyplanning is proposed, using multiple means promoting sustainable transport. It is concluded that a 100 per cent renewable energy transport system...... is possible but is connected to significant challenges in the path towards it. Biomass is a limited resource and it is important to avoid effecting the production of food. The integration of the transport with the energy system is crucial as is a multi-pronged strategy. Short term solutions have to consider...

  9. Lightning magnetic field measuring system in Bogota

    OpenAIRE

    Escobar Alvarado, Oscar Fernardo

    2013-01-01

    This thesis presents the configuration and performance of a lightning radiated electromagnetic field measuring system in Bogotá Colombia. The system is composed by both magnetic and electric field measuring systems working as separated sensors. The aim of the thesis is the design and construction of a Magnetic Field Measuring System and the implementation of a whole lightning measuring system in Bogotá. The theoretical background, design process, construction and implementation of the system ...

  10. CSNS magnet system and prototypes fabrication

    International Nuclear Information System (INIS)

    Deng Changdong; Chen Fusan; Sun Xianjing; Chen Wan; Sun Yaolin; Shi Caitu

    2008-01-01

    The 1.6 GeV synchrotron of China Spallation Neutron Source (CSNS) project is a Rapid Cycling Synchrotron (RCS), which accelerates a high-intensity proton beam from 80 MeV to 1.6 GeV at a repetition rate of 25 Hz. The RCS magnet system consists of 24 dipole magnets (main dipoles), 48 quadrupole magnets (main quadrupoles), 16 sextupole magnets, some tune shift quadrupoles and corrector magnets. All the magnets are of large aperture for a high beam power of 0.1 MW, one design issue is the fringe field at pole end. And the main dipoles and main quadrupoles work at 25 Hz repetition rate, the eddy current is an additional issue. In this paper the magnet design of the two kinds of main magnets will be described. (authors)

  11. Electronic transport in armchair graphene nanoribbon under double magnetic barrier modulation

    Science.gov (United States)

    Wang, Haiyan; Wu, Chao; Xie, Fang; Zhang, Xiaojiao; Zhou, Guanghui

    2018-03-01

    We present a theoretical investigation of the transport properties and the magnetoresistance effect in armchair graphene nanoribbons (AGNRs) under modulation by two magnetic barriers. The energy levels are found to be degenerate for a metallic AGNR but are not degenerate for a semiconducting AGNR. However, the conductance characteristics show quantized plateaus in both the metallic and semiconducting cases. When the magnetization directions of the barriers change from parallel to antiparallel, the conductance plateau in the metallic AGNR shows a degenerate feature due to matching between the transport modes in different regions. As the barrier height increases, the conductance shows more oscillatory behavior with sharp peaks and troughs. Specifically, the initial position of nonzero conductance for the metallic AGNR system moves towards a higher energy regime, which indicates that an energy gap has been opened. In addition, the magnetoresistance ratio also shows plateau structures in certain specific energy regions. These results may be useful in the design of electron devices based on AGNR nanostructures.

  12. METHODS OF INTEGRATED OPTIMIZATION MAGLEV TRANSPORT SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. Lasher

    2013-09-01

    Full Text Available Purpose. To demonstrate feasibility of the proposed integrated optimization of various MTS parameters to reduce capital investments as well as decrease any operational and maintenance expense. This will make use of MTS reasonable. At present, the Maglev Transport Systems (MTS for High-Speed Ground Transportation (HSGT almost do not apply. Significant capital investments, high operational and maintenance costs are the main reasons why Maglev Transport Systems (MTS are hardly currently used for the High-Speed Ground Transportation (HSGT. Therefore, this article justifies use of Theory of Complex Optimization of Transport (TCOT, developed by one of the co-authors, to reduce MTS costs. Methodology. According to TCOT, authors developed an abstract model of the generalized transport system (AMSTG. This model mathematically determines the optimal balance between all components of the system and thus provides the ultimate adaptation of any transport systems to the conditions of its application. To identify areas for effective use of MTS, by TCOT, the authors developed a dynamic model of distribution and expansion of spheres of effective use of transport systems (DMRRSEPTS. Based on this model, the most efficient transport system was selected for each individual track. The main estimated criterion at determination of efficiency of application of MTS is the size of the specific transportation tariff received from calculation of payback of total given expenses to a standard payback period or term of granting the credit. Findings. The completed multiple calculations of four types of MTS: TRANSRAPID, MLX01, TRANSMAG and TRANSPROGRESS demonstrated efficiency of the integrated optimization of the parameters of such systems. This research made possible expending the scope of effective usage of MTS in about 2 times. The achieved results were presented at many international conferences in Germany, Switzerland, United States, China, Ukraine, etc. Using MTS as an

  13. Influence of magnetic topology on transport and stability in Stellerators

    International Nuclear Information System (INIS)

    Castejon, F.; Fujisawa, A.; Ida, K.; Talmadge, J.N.; Estrada, T.; Lopez-Bruna, D.; Hidalgo, C.

    2005-01-01

    The influence of magnetic topology on transport and stability has been studied in four different stellarators: An almost shear less medium size flexible heliac (TJ-II), a medium size and a large heliotron (CHS and LHD) with shear, and a quasi helically symmetric device (HSX) with moderate shear. All of them can vary their rotational transform profiles, especially TJ-II that can do it by a factor of more than 2. LHD and HSX can vary their confinement properties by modifying their respective magnetic ripples. CHS has proven that the electric field can jump between the electron and ion roots. Experiments in these stellarators have allowed us to determine how transport and stability are modified when the magnetic topology is changed, and to understand better the mechanisms that act in the different devices. Low rational values of ?/2? can create transport barriers in LHD and TJ-II when they are located close to the plasma core or at the edge. This has been done either by scanning the rotational transform, driving currents using ECCD, or inducing OH currents. In this way it is demonstrated that low order rationals are not always deleterious for confinement but can be beneficial. The key ingredient to understand this fact is the appearance of a positive and sheared electric field in these plasmas, which is created by the additional non-ambipolar fluxes that appear due to the presence of the rationals. Moreover, the electric field approximately vanishes inside the island, which creates a sheared flow in its vicinity. LHD and TJ-II experiments indicate that it is possible to create ITBs in the plasma without the presence of low order rationals. This occurs when the electric field is created by neoclassical mechanisms and the electron root appears in the plasma core. ITBs also appear in CHS but the role of rationals is not clear yet in this device. The time evolution of the electric field has been studied and fast transitions have been found between high and low confinement

  14. Influence of magnetic topology on transport and stability in Stellerators

    Energy Technology Data Exchange (ETDEWEB)

    Castejon, F.; Fujisawa, A.; Ida, K.; Talmadge, J.N.; Estrada, T.; Lopez-Bruna, D.; Hidalgo, C.

    2005-07-01

    The influence of magnetic topology on transport and stability has been studied in four different stellarators: An almost shear less medium size flexible heliac (TJ-II), a medium size and a large heliotron (CHS and LHD) with shear, and a quasi helically symmetric device (HSX) with moderate shear. All of them can vary their rotational transform profiles, especially TJ-II that can do it by a factor of more than 2. LHD and HSX can vary their confinement properties by modifying their respective magnetic ripples. CHS has proven that the electric field can jump between the electron and ion roots. Experiments in these stellarators have allowed us to determine how transport and stability are modified when the magnetic topology is changed, and to understand better the mechanisms that act in the different devices. Low rational values of ?/2? can create transport barriers in LHD and TJ-II when they are located close to the plasma core or at the edge. This has been done either by scanning the rotational transform, driving currents using ECCD, or inducing OH currents. In this way it is demonstrated that low order rationals are not always deleterious for confinement but can be beneficial. The key ingredient to understand this fact is the appearance of a positive and sheared electric field in these plasmas, which is created by the additional non-ambipolar fluxes that appear due to the presence of the rationals. Moreover, the electric field approximately vanishes inside the island, which creates a sheared flow in its vicinity. LHD and TJ-II experiments indicate that it is possible to create ITBs in the plasma without the presence of low order rationals. This occurs when the electric field is created by neoclassical mechanisms and the electron root appears in the plasma core. ITBs also appear in CHS but the role of rationals is not clear yet in this device. The time evolution of the electric field has been studied and fast transitions have been found between high and low confinement

  15. Spin-polarized transport in manganite-based magnetic nano structures

    International Nuclear Information System (INIS)

    Granada, Mara

    2007-01-01

    Giant magnetoresistance (G M R) and tunnel magnetoresistance are spin polarized transport phenomena which are observed in magnetic multilayers.They consist in a large variation of the electrical resistivity of the system depending on whether the magnetizations of the magnetic layers are aligned parallel or anti-parallel to each other. In order to be able to align the magnetic layers by means of an external magnetic field, they must not be strongly ferromagnetically coupled.The extrinsic magnetoresistance effects in magnetic multilayers, either G M R in the case of a metallic spacer, or T M R in the case of an insulating spacer, are observed at low magnetic fields, which makes these phenomena interesting for technological applications.We studied the possibility of using the ferromagnetic manganite La 0 ,75Sr 0 ,25MnO 3 (L S M O) in magneto resistive devices, with different materials as a spacer layer.As the main result of this work, we report G M R and T M R measurements in L S M O/LaNiO 3 /L S M O and L S M O/CaMnO 3 /L S M O tri layers, respectively, observed for the first time in these systems.This work included the deposition of films and multilayers by sputtering, the structural characterization of the samples and the study of their magnetic and electric transport properties.Our main interest was the study of G M R in L S M O/LaNiO 3 /L S M O tri layers.It was necessary to firstly characterize the magnetic coupling of L S M O layers through the L N O spacer. After that, we performed electric transport measurements with the current in the plane of the samples.We measured a G M R contribution of ∼ 0,55 % at T = 83 K.We designed a procedure for patterning the samples by e-beam lithography for electric transport measurements with the current perpendicular to the plane. We also performed the study of L S M O/CaMnO 3 /L S M O tri layers with an insulating spacer.We studied the magnetic coupling, as in the previous case.Then we fabricated a tunnel junction for

  16. Instabilities, turbulence and transport in a magnetized plasma; Instabilites, turbulence et transport dans un plasma magnetise

    Energy Technology Data Exchange (ETDEWEB)

    Garbet, X

    2001-06-01

    The purpose of this work is to introduce the main processes that occur in a magnetized plasma. During the last 2 decades, the understanding of turbulence has made great progress but analytical formulas and simulations are far to produce reliable predictions. The values of transport coefficients in a tokamak plasma exceed by far those predicted by the theory of collisional transport. This phenomenon is called abnormal transport and might be due to plasma fluctuations. An estimation of turbulent fluxes derived from the levels of fluctuations, is proposed. A flow description of plasma allows the understanding of most micro-instabilities. The ballooning representation deals with instabilities in a toric geometry. 3 factors play an important role to stabilize plasmas: density pinch, magnetic shear and speed shear. The flow model of plasma gives an erroneous value for the stability threshold, this is due to a bad description of the resonant interaction between wave and particle. As for dynamics, flow models can be improved by adding dissipative terms so that the linear response nears the kinetic response. The kinetic approach is more accurate but is complex because of the great number of dimensions involved. (A.C.)

  17. Superconducting magnet systems in EPR designs

    International Nuclear Information System (INIS)

    Knobloch, A.F.

    1976-10-01

    Tokamak experiments have reached a stage where large scale application of superconductors can be envisaged for machines becoming operational within the next decade. Existing designs for future devices already indicate some of the tasks and problems associated with large superconducting magnet systems. Using this information the coming magnet system requirements are summarized, some design considerations given and in conclusion a brief survey describes already existing Tokamak magnet development programs. (orig.) [de

  18. Cooling system for superconducting magnet

    Science.gov (United States)

    Gamble, Bruce B.; Sidi-Yekhlef, Ahmed

    1998-01-01

    A cooling system is configured to control the flow of a refrigerant by controlling the rate at which the refrigerant is heated, thereby providing an efficient and reliable approach to cooling a load (e.g., magnets, rotors). The cooling system includes a conduit circuit connected to the load and within which a refrigerant circulates; a heat exchanger, connected within the conduit circuit and disposed remotely from the load; a first and a second reservoir, each connected within the conduit, each holding at least a portion of the refrigerant; a heater configured to independently heat the first and second reservoirs. In a first mode, the heater heats the first reservoir, thereby causing the refrigerant to flow from the first reservoir through the load and heat exchanger, via the conduit circuit and into the second reservoir. In a second mode, the heater heats the second reservoir to cause the refrigerant to flow from the second reservoir through the load and heat exchanger via the conduit circuit and into the first reservoir.

  19. Effect of magnetic axis shift on neoclassical transport in helical torus

    International Nuclear Information System (INIS)

    Sanuki, Heiji; Todoroki, Jiro

    2004-01-01

    Neoclassical transport for large helical device (LHD) configurations is studied by solving the bounce-averaged Fokker-Planck equation. Numerical code employed in the present paper (CHD1) is much faster and more efficient than existing transport codes. Effects of the magnetic axis shift on the mono-energetic transport coefficients are studied in detail for the LHD configurations, revealing that a strong inward shift of the magnetic axis can reduce remarkably the neoclassical ripple transport. (author)

  20. Close binary evolution. II. Impact of tides, wind magnetic braking, and internal angular momentum transport

    Science.gov (United States)

    Song, H. F.; Meynet, G.; Maeder, A.; Ekström, S.; Eggenberger, P.; Georgy, C.; Qin, Y.; Fragos, T.; Soerensen, M.; Barblan, F.; Wade, G. A.

    2018-01-01

    Context. Massive stars with solar metallicity lose important amounts of rotational angular momentum through their winds. When a magnetic field is present at the surface of a star, efficient angular momentum losses can still be achieved even when the mass-loss rate is very modest, at lower metallicities, or for lower-initial-mass stars. In a close binary system, the effect of wind magnetic braking also interacts with the influence of tides, resulting in a complex evolution of rotation. Aims: We study the interactions between the process of wind magnetic braking and tides in close binary systems. Methods: We discuss the evolution of a 10 M⊙ star in a close binary system with a 7 M⊙ companion using the Geneva stellar evolution code. The initial orbital period is 1.2 days. The 10 M⊙ star has a surface magnetic field of 1 kG. Various initial rotations are considered. We use two different approaches for the internal angular momentum transport. In one of them, angular momentum is transported by shear and meridional currents. In the other, a strong internal magnetic field imposes nearly perfect solid-body rotation. The evolution of the primary is computed until the first mass-transfer episode occurs. The cases of different values for the magnetic fields and for various orbital periods and mass ratios are briefly discussed. Results: We show that, independently of the initial rotation rate of the primary and the efficiency of the internal angular momentum transport, the surface rotation of the primary will converge, in a time that is short with respect to the main-sequence lifetime, towards a slowly evolving velocity that is different from the synchronization velocity. This "equilibrium angular velocity" is always inferior to the angular orbital velocity. In a given close binary system at this equilibrium stage, the difference between the spin and the orbital angular velocities becomes larger when the mass losses and/or the surface magnetic field increase. The

  1. Integrated transport and renewable energy systems

    DEFF Research Database (Denmark)

    Mathiesen, B.V.; Lund, H.; Nørgård, Per Bromand

    2007-01-01

    Governments worldwide aim at reducing CO2 emissions and expanding renewable energy. A key element in achieving such a goal is to use renewable energy in transport such as biofuels. However, efforts to promote single transport technologies and single fuels only represent a partial solution...... transport. It is concluded that a 100 per cent renewable energy transport system is possible but is connected to significant challenges in the path towards it. Biomass is a limited resource and it is important to avoid effecting the production. The integration of the transport with the remaining energy....... No single technology can solve the problem of ever increasing CO2 emissions from transport. Transport must be integrated into energy planning, as electricity and heating. In this paper, a coherent effort to integrate transport into energy planning is proposed, using multiple means promoting sustainable...

  2. Plasma transport in stochastic magnetic field caused by vacuum resonant magnetic perturbations at diverted tokamak edge

    International Nuclear Information System (INIS)

    Park, G.; Chang, C. S.; Joseph, I.; Moyer, R. A.

    2010-01-01

    A kinetic transport simulation for the first 4 ms of the vacuum resonant magnetic perturbations (RMPs) application has been performed for the first time in realistic diverted DIII-D tokamak geometry [J. Luxon, Nucl. Fusion 42, 614 (2002)], with the self-consistent evaluation of the radial electric field and the plasma rotation. It is found that, due to the kinetic effects, the stochastic parallel thermal transport is significantly reduced when compared to the standard analytic model [A. B. Rechester and M. N. Rosenbluth, Phys. Rev. Lett. 40, 38 (1978)] and the nonaxisymmetric perpendicular radial particle transport is significantly enhanced from the axisymmetric level. These trends agree with recent experimental result trends [T. E. Evans, R. A. Moyer, K. H. Burrell et al., Nat. Phys. 2, 419 (2006)]. It is also found, as a side product, that an artificial local reduction of the vacuum RMP fields in the vicinity of the magnetic separatrix can bring the kinetic simulation results to a more detailed agreement with experimental plasma profiles.

  3. Evolution of structural, magnetic and transport behavior by Pr doping in SrRuO3

    Science.gov (United States)

    Gupta, Renu; Pramanik, A. K.

    2018-05-01

    Here we report the evolution of structural, magnetic and transport behavior in perovskite based ruthenates Sr1-xPrxRuO3 (x=0.0 and 0.1). The substitution of Pr on Sr site retains orthorhombic structure while we find the slight change in structural parameters. The SrRuO3 has itinerant ferromagnet (FM) type nature of ordering temperature ˜160 K and below the transition temperature showing large bifurcation between ZFC and FC magnetization. By Pr doping, the magnetic moment decreases with decreasing bifurcation of ZFC and FC. The ZFC data show three distinct peaks (three transition temperature; TM1,TM2 and TM3). The magnetization study of both the samples, at high temperature fitted with modified CWL showing the decreasing value of ordering temperature by Pr doping matches close to TM2. The low-temperature isothermal magnetization M (H) data show that the high field saturation moment has decreased by Pr doping. The Arrott plot gives spontaneous magnetization (Ms) which is also decreased by Pr substitution. Evolution of Rhodes-Wohlfarth ratio value increases, which suggests that FM in this system evolves toward the more itinerant type by Pr doping. The electrical resistivity ρ(T) of both the samples show metallic behavior, in the all temperature range and ρ(T) increases by Pr doping while around below 45 K, the resistivity decreases by Pr doping and this crossing temperature also matches with ZFC data.

  4. Performances of the HL (Hyperloop) transport system

    OpenAIRE

    van Goeverden, C.D.; Milakis, D.; Janic, M.; Konings, J.W.; Cools, M.; Limbourg, S.

    2017-01-01

    This paper deals with an analysis of performances of the HL (Hyperloop) transport system considered as an advanced transport alternative to the existing APT (Air Passenger Transport) and HSR (High Speed Rail) systems. The considered performances are operational, financial, social and environmental. The operational performance include capacity and quality of service provided to the system’s users-passengers with attributes such as door-to-door travel time consisting of the access and egress ti...

  5. Anisotropic Pressure, Transport, and Shielding of Magnetic Perturbations

    International Nuclear Information System (INIS)

    Mynick, H.E.; Boozer, A.H.

    2008-01-01

    We compute the effect on a tokamak of applying a nonaxisymmetric magnetic perturbation (delta)B. An equilibrium with scalar pressure p yields zero net radial current, and therefore zero torque. Thus, the usual approach, which assumes scalar pressure, is not self-consistent, and masks the close connection which exists between that radial current and the in-surface currents, which provide shielding or amplification of (delta)B. Here, we analytically compute the pressure anisotropy, anisotropy, p # parallel#, p # perpendicular# and ≠ p, and from this, both the radial and in-surface currents. The surface-average of the radial current recovers earlier expressions for ripple transport, while the in-surface currents provide an expression for the amount of self-consistent shielding the plasma provides.

  6. Interaction effects in magnetic oxide nanoparticle systems

    Indian Academy of Sciences (India)

    The interaction effects in magnetic nanoparticle system were studied through a Monte Carlo simulation. The results of simulations were compared with two different magnetic systems, namely, iron oxide polymer nanocomposites prepared by polymerization over core and nanocrystalline cobalt ferrite thin films prepared by ...

  7. Indicator system for the environmental assessment of energy transport systems

    International Nuclear Information System (INIS)

    Knoepfel, I.

    1995-01-01

    The aim of this dissertation is to define a consistent set of indicators for the environmental assessment of different energy transport systems: high-voltage alternating and direct current transmission lines, electric cables, pipelines for gas and oil, inland waterway, road and rail transportation, according to state-of-the-art technologies. The indicator system is used for comparative analysis and identification of environmental hot-spots of the different systems. The environmental performance of power plants close to production or unloading terminals with subsequent power transmission and the transport of fossil fuels with power production close to the end-users is compared. Quantitative indicators are defined for different impact categories: fossil energy depletion, impacts from emissions, land use, noise impacts and visibility. A further aggregation of the different indicators to obtain a universal environmental score was not envisaged. It was not possible to define a quantitative indicator for possible electric and magnetic field effects because of insufficient knowledge of the involved dose-response metrics. The proposed indicators quantify dose-response relationships also below emission or immission limits imposed by law, which was one of the main requirements in this work. By reducing all information to an equivalent impacted area, a high level of consistency was achieved for land use, noise impacts and visibility indicators. Other indicators refer to the energy content of fossil resources and to equivalent emissions of reference substances. The calculation of an equivalent impacted area was not considered an efficient approach in these cases. The performance of the proposed indicator system and its applicability to infrastructure and regional planning is tested in two practical examples. (author) figs., tabs., refs

  8. Analysis and comparison of transportation security systems

    International Nuclear Information System (INIS)

    Rinne, R.L.

    1976-05-01

    The role of modeling in the analysis of transportation security systems is described. Various modeling approaches are outlined. The conflict model developed in Sandia Laboratories' Transportation Mode Analysis for the NRC Special Safeguards Study is used to demonstrate the capability of models to determine system sensitivities and compare alternatives

  9. ENERGETIC PARTICLE TRANSPORT ACROSS THE MEAN MAGNETIC FIELD: BEFORE DIFFUSION

    International Nuclear Information System (INIS)

    Laitinen, T.; Dalla, S.

    2017-01-01

    Current particle transport models describe the propagation of charged particles across the mean field direction in turbulent plasmas as diffusion. However, recent studies suggest that at short timescales, such as soon after solar energetic particle (SEP) injection, particles remain on turbulently meandering field lines, which results in nondiffusive initial propagation across the mean magnetic field. In this work, we use a new technique to investigate how the particles are displaced from their original field lines, and we quantify the parameters of the transition from field-aligned particle propagation along meandering field lines to particle diffusion across the mean magnetic field. We show that the initial decoupling of the particles from the field lines is slow, and particles remain within a Larmor radius from their initial meandering field lines for tens to hundreds of Larmor periods, for 0.1–10 MeV protons in turbulence conditions typical of the solar wind at 1 au. Subsequently, particles decouple from their initial field lines and after hundreds to thousands of Larmor periods reach time-asymptotic diffusive behavior consistent with particle diffusion across the mean field caused by the meandering of the field lines. We show that the typical duration of the prediffusive phase, hours to tens of hours for 10 MeV protons in 1 au solar wind turbulence conditions, is significant for SEP propagation to 1 au and must be taken into account when modeling SEP propagation in the interplanetary space.

  10. Ion and impurity transport in turbulent, anisotropic magnetic fields

    International Nuclear Information System (INIS)

    Negrea, M; Petrisor, I; Isliker, H; Vogiannou, A; Vlahos, L; Weyssow, B

    2011-01-01

    We investigate ion and impurity transport in turbulent, possibly anisotropic, magnetic fields. The turbulent magnetic field is modeled as a correlated stochastic field, with Gaussian distribution function and prescribed spatial auto-correlation function, superimposed onto a strong background field. The (running) diffusion coefficients of ions are determined in the three-dimensional environment, using two alternative methods, the semi-analytical decorrelation trajectory (DCT) method, and test-particle simulations. In a first step, the results of the test-particle simulations are compared with and used to validate the results obtained from the DCT method. For this purpose, a drift approximation was made in slab geometry, and relatively good qualitative agreement between the DCT method and the test-particle simulations was found. In a second step, the ion species He, Be, Ne and W, all assumed to be fully ionized, are considered under ITER-like conditions, and the scaling of their diffusivities is determined with respect to varying levels of turbulence (varying Kubo number), varying degrees of anisotropy of the turbulent structures and atomic number. In a third step, the test-particle simulations are repeated without drift approximation, directly using the Lorentz force, first in slab geometry, in order to assess the finite Larmor radius effects, and second in toroidal geometry, to account for the geometric effects. It is found that both effects are important, most prominently the effects due to toroidal geometry and the diffusivities are overestimated in slab geometry by an order of magnitude.

  11. Ion and impurity transport in turbulent, anisotropic magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Negrea, M; Petrisor, I [Department of Physics, Association Euratom-MEdC, Romania, University of Craiova, A.I. Cuza str. 13, Craiova (Romania); Isliker, H; Vogiannou, A; Vlahos, L [Section of Astrophysics, Astronomy and Mechanics, Department of Physics, University of Thessaloniki, Association Euratom-Hellenic Republic, 541 24 Thessaloniki (Greece); Weyssow, B [Physique Statistique-Plasmas, Association Euratom-Etat Belge, Universite Libre de Bruxelles, Campus Plaine, Bd. du Triomphe, 1050 Bruxelles (Belgium)

    2011-08-15

    We investigate ion and impurity transport in turbulent, possibly anisotropic, magnetic fields. The turbulent magnetic field is modeled as a correlated stochastic field, with Gaussian distribution function and prescribed spatial auto-correlation function, superimposed onto a strong background field. The (running) diffusion coefficients of ions are determined in the three-dimensional environment, using two alternative methods, the semi-analytical decorrelation trajectory (DCT) method, and test-particle simulations. In a first step, the results of the test-particle simulations are compared with and used to validate the results obtained from the DCT method. For this purpose, a drift approximation was made in slab geometry, and relatively good qualitative agreement between the DCT method and the test-particle simulations was found. In a second step, the ion species He, Be, Ne and W, all assumed to be fully ionized, are considered under ITER-like conditions, and the scaling of their diffusivities is determined with respect to varying levels of turbulence (varying Kubo number), varying degrees of anisotropy of the turbulent structures and atomic number. In a third step, the test-particle simulations are repeated without drift approximation, directly using the Lorentz force, first in slab geometry, in order to assess the finite Larmor radius effects, and second in toroidal geometry, to account for the geometric effects. It is found that both effects are important, most prominently the effects due to toroidal geometry and the diffusivities are overestimated in slab geometry by an order of magnitude.

  12. Ion and impurity transport in turbulent, anisotropic magnetic fields

    Science.gov (United States)

    Negrea, M.; Petrisor, I.; Isliker, H.; Vogiannou, A.; Vlahos, L.; Weyssow, B.

    2011-08-01

    We investigate ion and impurity transport in turbulent, possibly anisotropic, magnetic fields. The turbulent magnetic field is modeled as a correlated stochastic field, with Gaussian distribution function and prescribed spatial auto-correlation function, superimposed onto a strong background field. The (running) diffusion coefficients of ions are determined in the three-dimensional environment, using two alternative methods, the semi-analytical decorrelation trajectory (DCT) method, and test-particle simulations. In a first step, the results of the test-particle simulations are compared with and used to validate the results obtained from the DCT method. For this purpose, a drift approximation was made in slab geometry, and relatively good qualitative agreement between the DCT method and the test-particle simulations was found. In a second step, the ion species He, Be, Ne and W, all assumed to be fully ionized, are considered under ITER-like conditions, and the scaling of their diffusivities is determined with respect to varying levels of turbulence (varying Kubo number), varying degrees of anisotropy of the turbulent structures and atomic number. In a third step, the test-particle simulations are repeated without drift approximation, directly using the Lorentz force, first in slab geometry, in order to assess the finite Larmor radius effects, and second in toroidal geometry, to account for the geometric effects. It is found that both effects are important, most prominently the effects due to toroidal geometry and the diffusivities are overestimated in slab geometry by an order of magnitude.

  13. ENERGETIC PARTICLE TRANSPORT ACROSS THE MEAN MAGNETIC FIELD: BEFORE DIFFUSION

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, T.; Dalla, S., E-mail: tlmlaitinen@uclan.ac.uk [Jeremiah Horrocks Institute, University of Central Lancashire, Preston (United Kingdom)

    2017-01-10

    Current particle transport models describe the propagation of charged particles across the mean field direction in turbulent plasmas as diffusion. However, recent studies suggest that at short timescales, such as soon after solar energetic particle (SEP) injection, particles remain on turbulently meandering field lines, which results in nondiffusive initial propagation across the mean magnetic field. In this work, we use a new technique to investigate how the particles are displaced from their original field lines, and we quantify the parameters of the transition from field-aligned particle propagation along meandering field lines to particle diffusion across the mean magnetic field. We show that the initial decoupling of the particles from the field lines is slow, and particles remain within a Larmor radius from their initial meandering field lines for tens to hundreds of Larmor periods, for 0.1–10 MeV protons in turbulence conditions typical of the solar wind at 1 au. Subsequently, particles decouple from their initial field lines and after hundreds to thousands of Larmor periods reach time-asymptotic diffusive behavior consistent with particle diffusion across the mean field caused by the meandering of the field lines. We show that the typical duration of the prediffusive phase, hours to tens of hours for 10 MeV protons in 1 au solar wind turbulence conditions, is significant for SEP propagation to 1 au and must be taken into account when modeling SEP propagation in the interplanetary space.

  14. Anomalous Transport Properties of Dense QCD in a Magnetic Field

    Science.gov (United States)

    de la Incera, Vivian

    2017-06-01

    Despite recent advancements in the study and understanding of the phase diagram of strongly interacting matter, the region of high baryonic densities and low temperatures has remained difficult to reach in the lab. Things are expected to change with the planned HIC experiments at FAIR in Germany and NICA in Russia, which will open a window to the high-density-low-temperature segment of the QCD phase map, providing a unique opportunity to test the validity of model calculations that have predicted the formation of spatially inhomogeneous phases with broken chiral symmetry at intermediate-to-high densities. Such a density region is also especially relevant for the physics of neutron stars, as they have cores that can have several times the nuclear saturation density. On the other hand, strong magnetic fields, whose presence is fairly common in HIC and in neutron stars, can affect the properties of these exotic phases and lead to signatures potentially observable in these two settings. In this paper, I examine the anomalous transport properties produced by the spectral asymmetry of the lowest Landau level (LLL) in a QCD-inspired NJL model with a background magnetic field that exhibits chiral symmetry breaking at high density via the formation of a Dual Chiral Density Wave (DCDW) condensate. It turns out that in this model the electromagnetic interactions are described by the axion electrodynamics equations and there is a dissipationless Hall current.

  15. Dynamical properties of unconventional magnetic systems

    International Nuclear Information System (INIS)

    Helgesen, G.

    1997-05-01

    The Advanced Study Institute addressed the current experimental and theoretical knowledge of the dynamical properties of unconventional magnetic systems including low-dimensional and mesoscopic magnetism, unconventional ground state, quantum magnets and soft matter. The main approach in this Advanced Study Institute was to obtain basic understanding of co-operative phenomena, fluctuations and excitations in the wide range unconventional magnetic systems now being fabricated or envisioned. The report contains abstracts for lectures, invited seminars and posters, together with a list of the 95 participants from 24 countries with e-mail addresses

  16. Magnetic irone oxide nanoparticles in photosynthetic systems

    International Nuclear Information System (INIS)

    Khalilov, R.I.; Nasibova, A.N.; Khomutov, G.B.

    2014-01-01

    Full text : It was found and studied the effect of biogenic formation of magnetic inclusions in photosynthetic systems - in various higher plants under the influence of some external stress factors (radiation impact, moisture deficit) and in a model system - a suspension of chloroplasts. For registration and characterization of magnetic nanoparticles in the samples used EPR spectrometer because superparamagnetic and ferromagnetic nanoparticles have a chcracteristic signals of electron magnetic resonance. For direct visualization of magnetic nanoparticles it was used the method of transmission electron microscopy

  17. Models for large superconducting toroidal magnet systems

    International Nuclear Information System (INIS)

    Arendt, F.; Brechna, H.; Erb, J.; Komarek, P.; Krauth, H.; Maurer, W.

    1976-01-01

    Prior to the design of large GJ toroidal magnet systems it is appropriate to procure small scale models, which can simulate their pertinent properties and allow to investigate their relevant phenomena. The important feature of the model is to show under which circumstances the system performance can be extrapolated to large magnets. Based on parameters such as the maximum magnetic field and the current density, the maximum tolerable magneto-mechanical stresses, a simple method of designing model magnets is presented. It is shown how pertinent design parameters are changed when the toroidal dimensions are altered. In addition some conductor cost estimations are given based on reactor power output and wall loading

  18. Improvement of urban passenger transport ticketing systems by deploying intelligent transport systems

    Directory of Open Access Journals (Sweden)

    G. Jakubauskas

    2006-12-01

    Full Text Available The main advantages and disadvantages of conventional and intelligent ticketing systems and possible positive outcomes when introducing intelligent transport solutions – namely smart cards or e‑ticketing instead of conventional ones (paper tickets and magnetic cards are analysed in the paper. Two ideas of creating an intelligent ticketing system in an urban public transport are scrutinized. The first is electronic ticket and related equipment, the second – e-ticket and functional areas of it. In the article analysis has also been made on practical outcomes related with introduction of smart cards and e-ticketing. Practical tests and trials as well as a subsequent implementation of electronic tickets have proved unchallenged advantages of contactless smart cards against the contact ones. Nevertheless, a new age of modern technologies calls even for more effective solutions – namely virtual-ticketing systems that might be achieved through introduction of mobile technologies. Therefore, the main focus in the paper is made on the analysis of e-ticket.

  19. Steady State Turbulent Transport in Magnetic Fusion Plasmas

    International Nuclear Information System (INIS)

    Lee, W.W.; Ethier, S.; Kolesnikov, R.; Wang, W.X.; Tang, W.M.

    2007-01-01

    For more than a decade, the study of microturbulence, driven by ion temperature gradient (ITG) drift instabilities in tokamak devices, has been an active area of research in magnetic fusion science for both experimentalists and theorists alike. One of the important impetus for this avenue of research was the discovery of the radial streamers associated the ITG modes in the early nineties using a Particle-In-Cell (PIC) code. Since then, ITG simulations based on the codes with increasing realism have become possible with the dramatic increase in computing power. The notable examples were the demonstration of the importance of nonlinearly generated zonal flows in regulating ion thermal transport and the transition from Bohm to GyroBoham scaling with increased device size. In this paper, we will describe another interesting nonlinear physical process associated with the parallel acceleration of the ions, that is found to play an important role for the steady state turbulent transport. Its discovery is again through the use of the modern massively parallel supercomputers

  20. Crystal structural, magnetic and electrical transport properties of CeKFeMoO6 double perovskite

    International Nuclear Information System (INIS)

    Huo Guoyan; Ren Minghui; Wang Xiaoqing; Zhang Hongrui; Shi Pengfei

    2010-01-01

    The crystal structural, magnetic and electrical transport properties of double perovskite CeKFeMoO 6 have been investigated. The crystal structure of the compound is assigned to the monoclinic system with space group P2 1 /n and its lattice parameters are a=0.55345(3) nm, b=0.56068(2) nm, c=0.78390(1) nm, β=89.874(2). The divergence between zero-field-cooling and field-cooling M-T curves demonstrates the anisotropic behavior. The Curie temperature measured from C p -T curve is about 340 K. Isothermal magnetization curve shows that the saturation and spontaneous magnetization are 1.90 and 1.43 μ B /f.u. at 300 K, respectively. The electrical behavior of the sample shows a semiconductor. The electrical transport behavior can be described by variable range hopping model. Large magnetoresistance, -0.88 and -0.18, can be observed under low magnetic field, 0.5 T, at low and room temperature, respectively.

  1. Dynamic bioprocessing and microfluidic transport control with smart magnetic nanoparticles in laminar-flow devices.

    Science.gov (United States)

    Lai, James J; Nelson, Kjell E; Nash, Michael A; Hoffman, Allan S; Yager, Paul; Stayton, Patrick S

    2009-07-21

    In the absence of applied forces, the transport of molecules and particulate reagents across laminar flowstreams in microfluidic devices is dominated by the diffusivities of the transported species. While the differential diffusional properties between smaller and larger diagnostic targets and reagents have been exploited for bioseparation and assay applications, there are limitations to methods that depend on these intrinsic size differences. Here a new strategy is described for exploiting the sharply reversible change in size and magnetophoretic mobility of "smart" magnetic nanoparticles (mNPs) to perform bioseparation and target isolation under continuous flow processing conditions. The isolated 5 nm mNPs do not exhibit significant magnetophoretic velocities, but do exhibit high magnetophoretic velocities when aggregated by the action of a pH-responsive polymer coating. A simple external magnet is used to magnetophorese the aggregated mNPs that have captured a diagnostic target from a lower pH laminar flowstream (pH 7.3) to a second higher pH flowstream (pH 8.4) that induces rapid mNP disaggregation. In this second dis-aggregated state and flowstream, the mNPs continue to flow past the magnet rather than being immobilized at the channel surface near the magnet. This stimuli-responsive reagent system has been shown to transfer 81% of a model protein target from an input flowstream to a second flowstream in a continuous flow H-filter device.

  2. Attractive and repulsive magnetic suspension systems overview

    Science.gov (United States)

    Cope, David B.; Fontana, Richard R.

    1992-01-01

    Magnetic suspension systems can be used in a wide variety of applications. The decision of whether to use an attractive or repulsive suspension system for a particular application is a fundamental one which must be made during the design process. As an aid to the designer, we compare and contrast attractive and repulsive magnetic suspension systems and indicate whether and under what conditions one or the other system is preferred.

  3. Electrical and magnetic transport in Strontium doped Europium Ferrimanganites

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Latif, I.A. [Physics Department, College of Science & Arts, Najran University, P. O. 1988, Najran (Saudi Arabia); Reactor Physics Department, NRC, Atomic Energy Authority, Abou Zabaal P.O. 13759, Cairo (Egypt); Ahmed, Mahrous R. [Physics Department, Faculty of Science, Sohag University, Sohag 82524 (Egypt); Physics Department, Aljamoum University College, Um-Elqura University, Makka (Saudi Arabia); Al-Omari, I.A.; Sellai, A. [Physics Department, Faculty of Science, Soltan Qaboos University, P.O. Box 36, PC 123, Muscatt (Oman)

    2016-12-15

    Eu{sub 0.65}Sr{sub 0.35}Fe{sub x}Mn{sub 1−x}O{sub 3} (x=0.1, 0.3 and 0.5) has been prepared using a standard solid state reaction method. The under-investigation compounds is found to crystallize in a single-phase orthorhombic structure in the P{sub bnm} space group (62). The adiabatic polaron electronic transfer was obtained for all samples and the activation energy of x=0.1 sample is equal to 1.013 meV and slightly increase at x=0.3 (1.289 meV) while is doubled for x=0.5 to be 2.1065 meV. The magnetization–temperature dependence measurements of Eu{sub 0.65}Sr{sub 0.35}Fe{sub x}Mn{sub 1−x}O{sub 3} show the ferromagnetic ordering at low iron concentration x=0.1 and when iron concentration increase to x=0.5 the noncollinear magnetic ordering (the canted antiferromagnetic) is obtained. The magnetic phase transition (paramagnetic-ferromagnetic transition) in the Eu{sub 0.65}Sr{sub 0.35}Fe{sub 0.1}Mn{sub 0.9}O{sub 3} is observed at T{sub c} of 150 K. For Eu{sub 0.65}Sr{sub 0.35}Fe{sub 0.5}Mn{sub 0.5}O{sub 3} the multi-magnetic phase transition is observed at T{sub c} of 200K and T{sub N} of 430 K. The resistivity at low temperature is measured. Theoretical Calculations using Monte Carlo code have been done. The magnetization as function of temperature has been calculated using Monte Carlo simulations for Eu{sub 0.65}Sr{sub 0.35}Fe{sub x}Mn{sub 1−x}O{sub 3} (x=0.0, 0.1, 0,2, 0.3, 0.4 and 0.5). Ising model is a suitable model to study the magnetization for our compounds. The internal energy for x=0 is the highest value compared with the other x values which have nearly a ground state value equal to 2.7 J. - Highlights: • The distortion parameter in the crystal structure of Eu{sub 0.65}Sr{sub 0.35}Fe{sub x}Mn{sub 1−x}O{sub 3} increase with increasing concentration of iron and affected both electrical and magnetic transport. • The density of electrons over the unit cell decrease with increasing the iron concentration and thus give rise to the decrease in

  4. Design and simulation of permanent magnet synchronous motor control system

    Science.gov (United States)

    Li, Li; Liu, Yongqiu

    2018-06-01

    In recent years, with the development of power electronics, microelectronics, new motor control theory and rare earth permanent magnet materials, permanent magnet synchronous motors have been rapidly applied. Permanent magnet synchronous motors have the advantages of small size, low loss and high efficiency. Today, energy conservation and environmental protection are increasingly valued. It is very necessary to study them. Permanent magnet synchronous motor control system has a wide range of application prospects in the fields of electric vehicles, ships and other transportation. Using the simulation function of MATLAB/SIMULINK, a modular design structure was used to simulate the whole system model of speed loop adjustment, current PI modulation, SVPWM (Space Vector Pulse Width Module) wave generation and double closed loop. The results show that this control method has good robustness, and this method can improve the design efficiency and shorten the system design time. In this article, the analysis of the control principle of modern permanent magnet synchronous motor and the various processes of MATLAB simulation application will be analyzed in detail. The basic theory, basic method and application technology of the permanent magnet synchronous motor control system are systematically introduced.

  5. Plasma transport simulation modeling for helical confinement systems

    International Nuclear Information System (INIS)

    Yamazaki, K.; Amano, T.

    1991-08-01

    New empirical and theoretical transport models for helical confinement systems are developed based on the neoclassical transport theory including the effect of radial electric field and multi-helicity magnetic components, and the drift wave turbulence transport for electrostatic and electromagnetic modes, or the anomalous semi-empirical transport. These electron thermal diffusivities are compared with CHS (Compact Helical System) experimental data, which indicates that the central transport coefficient of the ECH plasma agrees with the neoclassical axi-symmetric value and the transport outside the half radius is anomalous. On the other hand, the transport of NBI-heated plasmas is anomalous in the whole plasma region. This anomaly is not explained by the electrostatic drift wave turbulence models in these flat-density-profile discharges. For the detailed prediction of plasma parameters in LHD (Large Helical Device), 3-D(dimensional) equilibrium/1-D transport simulations including empirical or drift wave turbulence models are carried out, which suggests that the global confinement time of LHD is determined mainly by the electron anomalous transport near the plasma edge region rather than the helical ripple transport in the core region. Even if the ripple loss can be eliminated, the increase of the global confinement is 10%. However, the rise in the central ion temperature is more than 20%. If the anomalous loss can be reduced to the half level of the present scaling, like so-called 'H-mode' of the tokamak discharge, the neoclassical ripple loss through the ion channel becomes important even in the plasma core. The 5% radial inward shift of the plasma column with respect to the major radius is effective for improving plasma confinement and raising more than 50% of the fusion product by reducing this neoclassical asymmetric ion transport loss and increasing 10% in the plasma radius. (author)

  6. Plasma transport simulation modelling for helical confinement systems

    International Nuclear Information System (INIS)

    Yamazaki, K.; Amano, T.

    1992-01-01

    New empirical and theoretical transport models for helical confinement systems are developed on the basis of the neoclassical transport theory, including the effect of the radial electric field and of multi-helicity magnetic components as well as the drift wave turbulence transport for electrostatic and electromagnetic modes or the anomalous semi-empirical transport. These electron thermal diffusivities are compared with experimental data from the Compact Helical System which indicate that the central transport coefficient of a plasma with electron cyclotron heating agrees with neoclassical axisymmetric value and the transport outside the half-radius is anomalous. On the other hand, the transport of plasmas with neutral beam injection heating is anomalous in the whole plasma region. This anomaly is not explained by the electrostatic drift wave turbulence models in these discharges with flat density profiles. For a detailed prediction of the plasma parameters in the Large Helical Device (LHD), 3-D equilibrium/1-D transport simulations including empirical or drift wave turbulence models are performed which suggest that the global confinement time of the LHD is determined mainly by the electron anomalous transport in the plasma edge region rather than by the helical ripple transport in the core region. Even if the ripple loss can be eliminated, the increase in global confinement is 10%. However, the rise in the central ion temperature is more than 20%. If the anomalous loss can be reduced to half of the value used in the present scaling, as is the case in the H-mode of tokamak discharges, the neoclassical ripple loss through the ion channel becomes important even in the plasma core. The 5% radial inward shift of the plasma column with respect to the major radius improves the plasma confinement and increases the fusion product by more than 50% by reducing the neoclassical asymmetric ion transport loss and increasing the plasma radius (10%). (author). 32 refs, 7 figs

  7. The transportation operations system: A description

    International Nuclear Information System (INIS)

    Best, R.E.; Danese, F.L.; Dixon, L.D.; Peterson, R.W.; Pope, R.B.

    1990-01-01

    This paper presents a description of the system for transporting radioactive waste that may be deployed to accomplish the assigned system mission, which includes accepting spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from waste generator sites and transporting them to the FWMS destination facilities. The system description presented here contains, in part, irradiated fuel and waste casks, ancillary equipments, truck, rail, and barge transporters, cask and vehicle traffic management organizations, maintenance facilities, and other operations elements. The description is for a fully implemented system, which is not expected to be achieved, however, until several years after initial operations. 6 figs

  8. Sensor Technologies for Intelligent Transportation Systems.

    Science.gov (United States)

    Guerrero-Ibáñez, Juan; Zeadally, Sherali; Contreras-Castillo, Juan

    2018-04-16

    Modern society faces serious problems with transportation systems, including but not limited to traffic congestion, safety, and pollution. Information communication technologies have gained increasing attention and importance in modern transportation systems. Automotive manufacturers are developing in-vehicle sensors and their applications in different areas including safety, traffic management, and infotainment. Government institutions are implementing roadside infrastructures such as cameras and sensors to collect data about environmental and traffic conditions. By seamlessly integrating vehicles and sensing devices, their sensing and communication capabilities can be leveraged to achieve smart and intelligent transportation systems. We discuss how sensor technology can be integrated with the transportation infrastructure to achieve a sustainable Intelligent Transportation System (ITS) and how safety, traffic control and infotainment applications can benefit from multiple sensors deployed in different elements of an ITS. Finally, we discuss some of the challenges that need to be addressed to enable a fully operational and cooperative ITS environment.

  9. Sensor Technologies for Intelligent Transportation Systems

    Science.gov (United States)

    Guerrero-Ibáñez, Juan; Zeadally, Sherali

    2018-01-01

    Modern society faces serious problems with transportation systems, including but not limited to traffic congestion, safety, and pollution. Information communication technologies have gained increasing attention and importance in modern transportation systems. Automotive manufacturers are developing in-vehicle sensors and their applications in different areas including safety, traffic management, and infotainment. Government institutions are implementing roadside infrastructures such as cameras and sensors to collect data about environmental and traffic conditions. By seamlessly integrating vehicles and sensing devices, their sensing and communication capabilities can be leveraged to achieve smart and intelligent transportation systems. We discuss how sensor technology can be integrated with the transportation infrastructure to achieve a sustainable Intelligent Transportation System (ITS) and how safety, traffic control and infotainment applications can benefit from multiple sensors deployed in different elements of an ITS. Finally, we discuss some of the challenges that need to be addressed to enable a fully operational and cooperative ITS environment. PMID:29659524

  10. Sensor Technologies for Intelligent Transportation Systems

    Directory of Open Access Journals (Sweden)

    Juan Guerrero-Ibáñez

    2018-04-01

    Full Text Available Modern society faces serious problems with transportation systems, including but not limited to traffic congestion, safety, and pollution. Information communication technologies have gained increasing attention and importance in modern transportation systems. Automotive manufacturers are developing in-vehicle sensors and their applications in different areas including safety, traffic management, and infotainment. Government institutions are implementing roadside infrastructures such as cameras and sensors to collect data about environmental and traffic conditions. By seamlessly integrating vehicles and sensing devices, their sensing and communication capabilities can be leveraged to achieve smart and intelligent transportation systems. We discuss how sensor technology can be integrated with the transportation infrastructure to achieve a sustainable Intelligent Transportation System (ITS and how safety, traffic control and infotainment applications can benefit from multiple sensors deployed in different elements of an ITS. Finally, we discuss some of the challenges that need to be addressed to enable a fully operational and cooperative ITS environment.

  11. Magnetic and transport properties of single and double perpendicular magnetic tunnel junctions

    International Nuclear Information System (INIS)

    Cuchet, Lea

    2015-01-01

    Due to their advantageous properties in terms of data retention, storage density and critical current density for Spin Transfer Torque (STT) switching, the magnetic tunnel junctions with perpendicular anisotropy have become predominant in the developments for MRAM applications. The aim of this thesis is to improve the anisotropy and transport properties of such structures and to realize even more complex stacks such as perpendicular double junctions. Studies on the magnetic properties and Tunnel Magnetoresistance (TMR) measurements showed that to optimize the performances of the junctions, all the thicknesses of the different layers constituting the stack have to be adapted. To guaranty both a large TMR as well a strong perpendicular anisotropy, compromises are most of the time needed. Studies as a function of magnetic thickness enabled to extract the saturation magnetization, the critical thickness and the magnetic dead layer thickness both in the bottom reference and the top storage layer in structures capped with Ta. This type of junction could be tested electrically after patterning the sample into nano-pillars. Knowing that perpendicular anisotropy mostly arises at the metal/oxide interface, the Ta capping layer was replaced by a MgO one, leading to a huge increase in the anisotropy of the free layer. A second top reference was then added on such a stack to create functional perpendicular double junctions. CoFeB/insertion/CoFeB synthetic antiferromagnetic storage layers could be developed and were proved to be stable enough to replace the standard Co/Pt-based reference layers. (author) [fr

  12. Pulsed Magnetic Field Improves the Transport of Iron Oxide Nanoparticles through Cell Barriers

    Science.gov (United States)

    Min, Kyoung Ah; Shin, Meong Cheol; Yu, Faquan; Yang, Meizhu; David, Allan E.; Yang, Victor C.; Rosania, Gus R.

    2013-01-01

    Understanding how a magnetic field affects the interaction of magnetic nanoparticles (MNPs) with cells is fundamental to any potential downstream applications of MNPs as gene and drug delivery vehicles. Here, we present a quantitative analysis of how a pulsed magnetic field influences the manner in which MNPs interact with, and penetrate across a cell monolayer. Relative to a constant magnetic field, the rate of MNP uptake and transport across cell monolayers was enhanced by a pulsed magnetic field. MNP transport across cells was significantly inhibited at low temperature under both constant and pulsed magnetic field conditions, consistent with an active mechanism (i.e. endocytosis) mediating MNP transport. Microscopic observations and biochemical analysis indicated that, in a constant magnetic field, transport of MNPs across the cells was inhibited due to the formation of large (>2 μm) magnetically-induced MNP aggregates, which exceeded the size of endocytic vesicles. Thus, a pulsed magnetic field enhances the cellular uptake and transport of MNPs across cell barriers relative to a constant magnetic field by promoting accumulation while minimizing magnetically-induced MNP aggregates at the cell surface. PMID:23373613

  13. Spin transport in diffusive ferromagnetic Josephson junctions with noncollinear magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Shomali, Zahra; Zareyan, Malek [Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45195 (Iran, Islamic Republic of); Belzig, Wolfgang [Fachbereich Physik, Universitaet Konstanz, D-78457 Konstanz (Germany)

    2011-07-01

    We numerically study the Josephson coupling of two s-wave superconductors which are connected through a diffusive contact made of two ferromagnetic domains with the magnetization vectors misoriented by an angle {theta}. The assumed superconducting leads are conventional s-wave type with the phase difference of {phi}. Using the quantum circuit theory, we find that in addition to the charge supercurrent, which shows a 0-{pi} transition relative to the angle {theta}, the spin supercurrent with a spin polarization normal to the magnetization vectors will flow through the contact. Our results present a 0-{pi} quantum phase transition as a function of the wave vector, Q{xi}. Finally, we investigate the spin supercurrent in an extended magnetic texture with multiple domain walls. We find the behavior of spin supercurrent is highly sensitive to the barrier. When asymmetric barriers don't change the value of the spin supercurrent, the symmetric ones decrease the value of it notably. We also investigate some other interesting effects for these systems. In addition, we present when Q{xi} is the even multiple of {pi}, the spin-current which is penetrated into the nonhomogeneous ferromagnets is nearly zero, how ever the odd ones show the large amount of penetrated spin supercurrent.

  14. Transport and magnetism correlations in thin-film ferromagnetic oxides

    International Nuclear Information System (INIS)

    Hundley, M.F.; Neumeier, J.J.; Heffner, R.H.; Jia, Q.X.; Wu, X.D.; Thompson, J.D.

    1995-01-01

    In order to determine the T c -dependence of the colossal magnetoresistance (MR) exhibited by the ferromagnetic La 0.7 M 0.3 MnO 3+σ (M = Ba, Ca, Sr) system, the authors examine the magnetic-field and temperature dependent resistivity and magnetization of a series of thin films that were grown via pulsed-laser deposition. The films had magnetic ordering temperatures (T C ) ranging from 150 to 350 K; all samples displayed a large negative MR that is largest near T c . The magnitude of a given sample's MR at T c inversely correlates with T c ; samples with a low T c display significantly larger MR values than do samples with large T c 's. The quantity ρ(T c )/ρ(4 K), the amount by which the resistivity is reduced by full ferromagnetic order, is an activated function of T c with an activation energy E a = 0.1 eV. These results indicate that the magnitude of the CMR effect in a given specimen is controlled not by ρ(T c ), but by T c via the ratio ρ(T c )/ρ(4 K). Phenomenological scaling relationships are also reported that link ρ(H,T) to both H and M(H, T)

  15. Electron-vibron coupling effects on electron transport via a single-molecule magnet

    NARCIS (Netherlands)

    McCaskey, A.; Yamamoto, Y.; Warnock, M.; Burzuri, E.; Van der Zant, H.S.J.; Park, K.

    2015-01-01

    We investigate how the electron-vibron coupling influences electron transport via an anisotropic magnetic molecule, such as a single-molecule magnet (SMM) Fe4, by using a model Hamiltonian with parameter values obtained from density-functional theory (DFT). The magnetic anisotropy parameters,

  16. Creation, transport and detection of imprinted magnetic solitons stabilized by spin-polarized current

    Science.gov (United States)

    Loreto, R. P.; Moura-Melo, W. A.; Pereira, A. R.; Zhang, X.; Zhou, Y.; Ezawa, M.; de Araujo, C. I. L.

    2018-06-01

    With the recent proposition of skyrmion utilization in racetrack memories at room temperature, skyrmionics has become a very attractive field. However, for the stability of skyrmions, it is essential to incorporate the Dzyaloshinskii-Moriya interaction (DMI) and the out-of-plane magnetic field into the system. In this work, we explore a system without these interactions. First, we propose a controlled way for the creation of magnetic skyrmions and skyrmioniums imprinted on a ferromagnetic nanotrack via a nanopatterned nanodisk with the magnetic vortex state. Then we investigate the detachment of the imprinted spin textures from the underneath of the nanodisk, as well as its transport by the spin-transfer torque imposed by spin-polarized current pulses applied in the nanotrack. A prominent feature of the moving imprinted spin texture is that its topological number Q is oscillating around the averaged value of Q = 0 as if it is a resonant state between the skyrmions with Q = ± 1 and the bubble with Q = 0 . We may call it a resonant magnetic soliton (RMS). A RMS moves along a straight line since it is free from the skyrmion Hall effect. In our studied device, the same electrodes are employed to realize the imprinted spin texture detachment and its transport. In addition, we have investigated the interaction between the RMS and a magnetic tunnel junction sensor, where the passing of the RMS in the nanotrack can be well detected. Our results would be useful for the development of novel spintronic devices based on moveable spin textures.

  17. Driverless operation for public passenger transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Kehl, R. [Siemens AG, Erlangen (Germany). Bereich Verkehrstechnik

    2001-07-01

    The author presents the automation of new and existing lines as a possible solution to the twin problems of the growing need for public transport and the threat of collapse facing many public transport systems in the big conurbations as they wrestle against overloading. It emerges that automatic, driverless operation is a suitable approach to making systems more flexible and more attractive. Automation can increase the capacities of existing systems significantly and thus help them gain more passengers. (orig.)

  18. Superconducting magnetic systems and electrical machines

    International Nuclear Information System (INIS)

    Glebov, I.A.

    1975-01-01

    The use of superconductors for magnets and electrical machines attracts close attention of designers and scientists. A description is given of an ongoing research program to create superconductive magnetic systems, commutator motors, homopolar machines, topological generators and turbogenerators with superconductive field windings. All the machines are tentative experimental models and serve as a basis for further developments

  19. Radial electric field and transport near the rational surface and the magnetic island in LHD

    International Nuclear Information System (INIS)

    Ida, K.; Inagaki, S.; Tamura, N.

    2002-10-01

    The structure of the radial electric field and heat transport at the magnetic island in the Large Helical Device is investigated by measuring the radial profile of poloidal flow with charge exchange spectroscopy. The convective poloidal flow inside the island is observed when the n/m=1/1 external perturbation field becomes large enough to increase the magnetic island width above a critical value (15-20% of minor radius) in LHD. This convective poloidal flow results in a non-flat space potential inside the magnetic island. The sign of the curvature of the space potential depends on the radial electric field at the boundary of the magnetic island. The heat transport inside the magnetic island is studied with a cold pulse propagation technique. The experimental results show the existence of the radial electric field shear at the boundary of the magnetic island and a reduction of heat transport inside the magnetic island. (author)

  20. 49 CFR 37.33 - Airport transportation systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Airport transportation systems. 37.33 Section 37.33 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.33 Airport transportation systems. (a) Transportation...

  1. Superconducting property measuring system by magnetization method

    International Nuclear Information System (INIS)

    Ikisawa, K.; Mori, T.; Takasu, N.

    1988-01-01

    Superconducting property measuring system (CMS-370B) for high temperature oxide superconductor has been developed. This system adopts magnetization measurement. The superconducting properties are able to be measured automatically and continuously changing the temperature and external magnetic field. The critical current density as a function of temperature and magnetic field of high temperature superconductor YBa 2 Cu 3 O 7-y (YBCO) has been measured. This paper reports how it was confirmed that this system having the high performance and the accuracy gave the significant contribution to the superconducting material development

  2. Integrated design for space transportation system

    CERN Document Server

    Suresh, B N

    2015-01-01

    The book addresses the overall integrated design aspects of a space transportation system involving several disciplines like propulsion, vehicle structures, aerodynamics, flight mechanics, navigation, guidance and control systems, stage auxiliary systems, thermal systems etc. and discusses the system approach for design, trade off analysis, system life cycle considerations, important aspects in mission management, the risk assessment, etc. There are several books authored to describe the design aspects of various areas, viz., propulsion, aerodynamics, structures, control, etc., but there is no book which presents space transportation system (STS) design in an integrated manner. This book attempts to fill this gap by addressing systems approach for STS design, highlighting the integrated design aspects, interactions between various subsystems and interdependencies. The main focus is towards the complex integrated design to arrive at an optimum, robust and cost effective space transportation system. The orbit...

  3. Electrical protection of superconducting magnet systems

    International Nuclear Information System (INIS)

    Sutter, D.F.; Flora, R.H.

    1975-01-01

    The problem of dissipating the energy stored in the field of a superconducting magnet when a quench occurs has received considerable study. However, when the magnet becomes a system 4 miles in length whose normal operation is an ac mode, some re-examination of standard techniques for dissipating energy outside the magnets is in order. Data accumulated in the Fermilab Energy Doubler magnet development program shows that heating associated with the temporal and spatial development of quenches is highly localized and can result in temperatures damaging to the superconducting wire. The design and operation are discussed for several energy dumping schemes, compatible with the operation of ac superconducting magnets, wherein more than 70 percent of the stored energy can be dissipated outside the magnet. Instrumentation to detect quenches early in their development and circuits for dumping the field energy are described, and representative operating performance data for the dump circuits and data showing temporal development of quenches are presented. (auth)

  4. Magnetic and/or electric label assisted detection system and method

    NARCIS (Netherlands)

    2008-01-01

    A detection system is described for detecting analytes in a fluid sample. The detection system comprises a transporting means for transporting magnetic and/or elec. labels after interaction between the sample fluid and the reagents towards a detection receptacle. The detection receptacle is

  5. Theory of high-resolution tunneling spin transport on a magnetic skyrmion

    OpenAIRE

    Palotás, Krisztián; Rózsa, Levente; Szunyogh, László

    2018-01-01

    Tunneling spin transport characteristics of a magnetic skyrmion are described theoretically in magnetic scanning tunneling microscopy (STM). The spin-polarized charge current in STM (SP-STM) and tunneling spin transport vector quantities, the longitudinal spin current and the spin transfer torque are calculated in high spatial resolution within the same theoretical framework. A connection between the conventional charge current SP-STM image contrasts and the magnitudes of the spin transport v...

  6. Magnetic Processing of Structural Components for Transportation Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Mackiewicz-Ludtka, G.; Ludtka, G. M.; Fleming, S. [Metalsa Roanoke, Inc.; del Prado Villasana, J. [Metalsa Roanoke, Inc.

    2011-09-30

    The specific goal of this project was to develop and evaluate the effect of magnetic processing as a viable and new technology to manufacture side‐rails for heavy trucks; and to demonstrate the applicability of this technology for an industrial truck/automotive process. The targeted performance enhancements for this project were to increase the hardness or strength of two families of alloys (comparable carbon contents but one alloy system incorporating hardenability improving additions of titanium and boron) by 15 to 20%. Thermomagnetic processing has been shown to make significant and unprecedented, simultaneous improvements in yield strength and ultimate tensile strength with no loss of ductility for the truck rail application investigated in this project. Improvements in the ultimate tensile strength and yield strength in the range 20 to 30% have been measured even for the lower hardenability alloy samples that only received a very low magnetic field tempering treatment at a tempering temperature that was 67% lower than the current non-magnetic field enhanced commercial process and for a brief tempering time of 20% of the time required in their current process at the higher temperature. These significant developments, that require further demonstration and investigation on current commercial and other alloy systems, promise the evolution of a much more energy efficient and lower-carbon footprint process to be used in the future to produce stronger, tougher, and lighter weight truck rails. The property increases in the truck rails themselves will enable lighter weight truck side-rails to be produced which will reduce the overall weight of heavy duty trucks which will reduce fuel consumption and be an enabler of the goals of the DOE EERE SuperTruck Program where fuel consumption reductions of 50% are targeted for the future generation of trucks.

  7. Internal transport barrier physics in helical systems

    International Nuclear Information System (INIS)

    Yokoyama, M.; Minami, T.; Fujisawa, A.; Herranz, J.; Ida, K.; Yamagishi, O.; Yamada, H.; Maaberg, H.; Beidler, C.D.; Dinklage, A.; Estrada, T.; Castejon, F.; Murakami, S.

    2005-01-01

    The electron internal transport barrier (eITB) has been observed in wide range of helical systems, such as CHS [eg.,1], LHD [eg., 2], TJ-II [eg., 3] and W7-AS [eg., 4]. The eITB isA defined as highly peaked electron temperature (Te) profile with strongly positive radial electric field (Er) in the central region. These observations are reviewed in this paper to understand the device-independent common findings and also to draw the main differences. This is the first report from the International Stellarator Profile Database Activity. The formation of the strong central positive Er has been understood mainly as a result of the ambipolarity of neoclassical electron and ion fluxes, although some additional convective electron flux such as driven by ECRH is required in some situations. This 'neoclassical' physics peculiar to low collisional regime of helical plasmas provides the commonly observed existence of the ECRH power threshold (which is also depending on the density). This is contrastive characteristics to the ITB observed in tokamaks. The dependence of the ECRH power threshold on the magnetic configuration and on the heating scenario among these devices are currently being examined by taking the effective ripple and the trapped particle fraction as parameters to achieve the comprehensive understanding. The roles of low order rational surfaces on the onset of eITB formation and also on its radial size (location of the footpoint of the eITB) have been indicated in inward shifted configurations in LHD (depending on the relative locations of heating position and 2/1 island) and TJ-II (eITB becomes possible at higher density when 3/2 rational is introduced in the plasma core region). It is speculated that, for the latter case, the resonance causes an extra electron flux to trigger the positive Er. The interplay between low order rational surfaces and the formation of eITB still waits for the systematic experiment and theoretical analysis. The external controllability

  8. Magnetic Transport in Spin Antiferromagnets for Spintronics Applications

    Directory of Open Access Journals (Sweden)

    Mohamed Azzouz

    2017-10-01

    Full Text Available Had magnetic monopoles been ubiquitous as electrons are, we would probably have had a different form of matter, and power plants based on currents of these magnetic charges would have been a familiar scene of modern technology. Magnetic dipoles do exist, however, and in principle one could wonder if we can use them to generate magnetic currents. In the present work, we address the issue of generating magnetic currents and magnetic thermal currents in electrically-insulating low-dimensional Heisenberg antiferromagnets by invoking the (broken electricity-magnetism duality symmetry. The ground state of these materials is a spin-liquid state that can be described well via the Jordan–Wigner fermions, which permit an easy definition of the magnetic particle and thermal currents. The magnetic and magnetic thermal conductivities are calculated in the present work using the bond–mean field theory. The spin-liquid states in these antiferromagnets are either gapless or gapped liquids of spinless fermions whose flow defines a current just as the one defined for electrons in a Fermi liquid. The driving force for the magnetic current is a magnetic field with a gradient along the magnetic conductor. We predict the generation of a magneto-motive force and realization of magnetic circuits using low-dimensional Heisenberg antiferromagnets. The present work is also about claiming that what the experiments in spintronics attempt to do is trying to treat the magnetic degrees of freedoms on the same footing as the electronic ones.

  9. Theory of high-resolution tunneling spin transport on a magnetic skyrmion

    Science.gov (United States)

    Palotás, Krisztián; Rózsa, Levente; Szunyogh, László

    2018-05-01

    Tunneling spin transport characteristics of a magnetic skyrmion are described theoretically in magnetic scanning tunneling microscopy (STM). The spin-polarized charge current in STM (SP-STM) and tunneling spin transport vector quantities, the longitudinal spin current and the spin transfer torque, are calculated in high spatial resolution within the same theoretical framework. A connection between the conventional charge current SP-STM image contrasts and the magnitudes of the spin transport vectors is demonstrated that enables the estimation of tunneling spin transport properties based on experimentally measured SP-STM images. A considerable tunability of the spin transport vectors by the involved spin polarizations is also highlighted. These possibilities and the combined theory of tunneling charge and vector spin transport pave the way for gaining deep insight into electric-current-induced tunneling spin transport properties in SP-STM and to the related dynamics of complex magnetic textures at surfaces.

  10. H- beam neutralization measurements in a solenoidal beam transport system

    International Nuclear Information System (INIS)

    Sherman, J.; Pitcher, E.; Stevens, R.; Allison, P.

    1992-01-01

    H minus beam space-charge neutralization is measured for 65-mA, 35-keV beams extracted from a circular-aperture Penning surface-plasma source, the small-angle source. The H minus beam is transported to a RFQ matchpoint by a two-solenoid magnet system. Beam noise is typically ±4%. A four-grid analyzer is located in a magnetic-field-free region between the two solenoid magnets. H minus potentials are deduced from kinetic energy measurements of particles (electrons and positive ions) ejected radially from the beam channel by using a griddled energy analyzer. Background neutral gas density is increased by the introduction of additional Xe and Ar gases, enabling the H minus beam to become overneutralized

  11. PEP magnet power supply systems

    International Nuclear Information System (INIS)

    Jackson, L.T.

    1977-01-01

    The dc electrical requirements of the PEP magnets fall mainly into two categories: (1) high power and current of single polarity and (2) low-power bi-polar. The first category will be thyristor-chopper controlled off common 600 V dc busses. The second group will utilize continuously controlled push-pull transistor actuators

  12. RELIABILITY OF TRANSPORTATION SYSTEMS OF ROCK HAPS

    Directory of Open Access Journals (Sweden)

    A. Stepanov

    2009-01-01

    Full Text Available The ways of increasing of exploitation reliability of dump trucks with the aim of increasing of effectiveness of exploitation of transportation systems of rock heaps at coal mines.

  13. Intelligent Transportation Systems statewide architecture : final report.

    Science.gov (United States)

    2003-06-01

    This report describes the development of Kentuckys Statewide Intelligent Transportation Systems (ITS) Architecture. The process began with the development of an ITS Strategic Plan in 1997-2000. A Business Plan, developed in 2000-2001, translated t...

  14. Magnetic properties of singlet ground state systems

    International Nuclear Information System (INIS)

    Diederix, K.M.

    1979-01-01

    Experiments are described determining the properties of a magnetic system consisting of a singlet ground state. Cu(NO 3 ) 2 .2 1/2H 2 O has been studied which is a system of S = 1/2 alternating antiferromagnetic Heisenberg chains. The static properties, spin lattice relaxation time and field-induced antiferromagnetically ordered state measurements are presented. Susceptibility and magnetic cooling measurements of other compounds are summarised. (Auth.)

  15. Kinetic transport in a magnetically confined and flux-constrained fusion plasma

    International Nuclear Information System (INIS)

    Darmet, G.

    2007-11-01

    This work deals with the kinetic transport in a fusion plasma magnetically confined and flux-constrained. The author proposes a new interpretation of the dynamics of zonal flows. The model that has been studied is a gyrokinetic model reduced to the transport of trapped ions. The inter-change stability that is generated allows the study of the kinetic transport of trapped ions. This model has a threshold instability and can be simulated over a few tens confining time for either thermal bath constraint or flux constraint. For thermal baths constraint, the simulation shows a metastable state where zonal flows are prevailing while turbulence is non-existent. In the case of a flux-constraint, zonal flows appear and relax by exchanging energy with system's kinetic energy and turbulence energy. The competition between zonal flows and turbulence can be then simulated by a predator-prey model. 2 regimes can be featured out: an improved confining regime where zonal flows dominate transport and a turbulent regime where zonal flows and turbulent transport are of the same magnitude order. We show that flux as well as the Reynolds tensor play an important role in the dynamics of the zonal flows and that the gyrokinetic description is relevant for all plasma regions. (A.C.)

  16. Transport and Dynamics in Toroidal Fusion Systems

    International Nuclear Information System (INIS)

    Sovinec, Carl

    2016-01-01

    The study entitled, 'Transport and Dynamics in Toroidal Fusion Systems,' (TDTFS) applied analytical theory and numerical computation to investigate topics of importance to confining plasma, the fourth state of matter, with magnetic fields. A central focus of the work is how non-thermal components of the ion particle distribution affect the 'sawtooth' collective oscillation in the core of the tokamak magnetic configuration. Previous experimental and analytical research had shown and described how the oscillation frequency decreases and amplitude increases, leading to 'monster' or 'giant' sawteeth, when the non-thermal component is increased by injecting particle beams or by exciting ions with imposed electromagnetic waves. The TDTFS study applied numerical computation to self-consistently simulate the interaction between macroscopic collective plasma dynamics and the non-thermal particles. The modeling used the NIMROD code [Sovinec, Glasser, Gianakon, et al., J. Comput. Phys. 195, 355 (2004)] with the energetic component represented by simulation particles [Kim, Parker, Sovinec, and the NIMROD Team, Comput. Phys. Commun. 164, 448 (2004)]. The computations found decreasing growth rates for the instability that drives the oscillations, but they were ultimately limited from achieving experimentally relevant parameters due to computational practicalities. Nonetheless, this effort provided valuable lessons for integrated simulation of macroscopic plasma dynamics. It also motivated an investigation of the applicability of fluid-based modeling to the ion temperature gradient instability, leading to the journal publication [Schnack, Cheng, Barnes, and Parker, Phys. Plasmas 20, 062106 (2013)]. Apart from the tokamak-specific topics, the TDTFS study also addressed topics in the basic physics of magnetized plasma and in the dynamics of the reversed-field pinch (RFP) configuration. The basic physics work contributed to a study of two

  17. Transport and Dynamics in Toroidal Fusion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sovinec, Carl [Univ. of Wisconsin, Madison, WI (United States)

    2016-09-07

    The study entitled, "Transport and Dynamics in Toroidal Fusion Systems," (TDTFS) applied analytical theory and numerical computation to investigate topics of importance to confining plasma, the fourth state of matter, with magnetic fields. A central focus of the work is how non-thermal components of the ion particle distribution affect the "sawtooth" collective oscillation in the core of the tokamak magnetic configuration. Previous experimental and analytical research had shown and described how the oscillation frequency decreases and amplitude increases, leading to "monster" or "giant" sawteeth, when the non-thermal component is increased by injecting particle beams or by exciting ions with imposed electromagnetic waves. The TDTFS study applied numerical computation to self-consistently simulate the interaction between macroscopic collective plasma dynamics and the non-thermal particles. The modeling used the NIMROD code [Sovinec, Glasser, Gianakon, et al., J. Comput. Phys. 195, 355 (2004)] with the energetic component represented by simulation particles [Kim, Parker, Sovinec, and the NIMROD Team, Comput. Phys. Commun. 164, 448 (2004)]. The computations found decreasing growth rates for the instability that drives the oscillations, but they were ultimately limited from achieving experimentally relevant parameters due to computational practicalities. Nonetheless, this effort provided valuable lessons for integrated simulation of macroscopic plasma dynamics. It also motivated an investigation of the applicability of fluid-based modeling to the ion temperature gradient instability, leading to the journal publication [Schnack, Cheng, Barnes, and Parker, Phys. Plasmas 20, 062106 (2013)]. Apart from the tokamak-specific topics, the TDTFS study also addressed topics in the basic physics of magnetized plasma and in the dynamics of the reversed-field pinch (RFP) configuration. The basic physics work contributed to a study of two-fluid effects on interchange dynamics, where

  18. Magnetic systems for fusion devices

    International Nuclear Information System (INIS)

    Henning, C.D.

    1985-02-01

    Mirror experiments have led the way in applying superconductivity to fusion research because of unique requirements for high and steady magnetic fields. The first significant applications were Baseball II at LLNL and IMP at ORNL. More recently, the MFTF-B yin-yang coil was successfully tested and the entire tandem configuration is nearing completion. Tokamak magnets have also enjoyed recent success with the large coil project tests at ORNL, preceded by single coil tests in Japan and Germany. In the USSR, the T-7 Tokamak has been operational for many years and the T-15 Tokamak is under construction, with the TF coils nearing completion. Also the Tore Supra is being built in France

  19. Systemic Analysis Approaches for Air Transportation

    Science.gov (United States)

    Conway, Sheila

    2005-01-01

    Air transportation system designers have had only limited success using traditional operations research and parametric modeling approaches in their analyses of innovations. They need a systemic methodology for modeling of safety-critical infrastructure that is comprehensive, objective, and sufficiently concrete, yet simple enough to be used with reasonable investment. The methodology must also be amenable to quantitative analysis so issues of system safety and stability can be rigorously addressed. However, air transportation has proven itself an extensive, complex system whose behavior is difficult to describe, no less predict. There is a wide range of system analysis techniques available, but some are more appropriate for certain applications than others. Specifically in the area of complex system analysis, the literature suggests that both agent-based models and network analysis techniques may be useful. This paper discusses the theoretical basis for each approach in these applications, and explores their historic and potential further use for air transportation analysis.

  20. The WIPP transportation system: Dedicated to safety

    International Nuclear Information System (INIS)

    Ward, T.; McFadden, M.

    1993-01-01

    When developing a transportation system to transport transuranic (TRU) waste from ten widely-dispersed generator sites, the Department of Energy (DOE) recognized and addressed many challenges. Shipments of waste to the Waste Isolation Pilot Plant (WIPP) were to cover a twenty-five year period and utilize routes covering over twelve thousand miles in twenty-three states. Enhancing public safety by maximizing the payload, thus reducing the number of shipments, was the primary objective. To preclude the requirement for overweight permits, the DOE started with a total shipment weight limit of 80,000 pounds and developed an integrated transportation system consisting of a Type ''B'' package to transport the material, a lightweight tractor and trailer, stringent driver requirements, and a shipment tracking system referred to as ''TRANSCOM''

  1. Fault tolerant computer control for a Maglev transportation system

    Science.gov (United States)

    Lala, Jaynarayan H.; Nagle, Gail A.; Anagnostopoulos, George

    1994-01-01

    Magnetically levitated (Maglev) vehicles operating on dedicated guideways at speeds of 500 km/hr are an emerging transportation alternative to short-haul air and high-speed rail. They have the potential to offer a service significantly more dependable than air and with less operating cost than both air and high-speed rail. Maglev transportation derives these benefits by using magnetic forces to suspend a vehicle 8 to 200 mm above the guideway. Magnetic forces are also used for propulsion and guidance. The combination of high speed, short headways, stringent ride quality requirements, and a distributed offboard propulsion system necessitates high levels of automation for the Maglev control and operation. Very high levels of safety and availability will be required for the Maglev control system. This paper describes the mission scenario, functional requirements, and dependability and performance requirements of the Maglev command, control, and communications system. A distributed hierarchical architecture consisting of vehicle on-board computers, wayside zone computers, a central computer facility, and communication links between these entities was synthesized to meet the functional and dependability requirements on the maglev. Two variations of the basic architecture are described: the Smart Vehicle Architecture (SVA) and the Zone Control Architecture (ZCA). Preliminary dependability modeling results are also presented.

  2. An adaptive robust controller for time delay maglev transportation systems

    Science.gov (United States)

    Milani, Reza Hamidi; Zarabadipour, Hassan; Shahnazi, Reza

    2012-12-01

    For engineering systems, uncertainties and time delays are two important issues that must be considered in control design. Uncertainties are often encountered in various dynamical systems due to modeling errors, measurement noises, linearization and approximations. Time delays have always been among the most difficult problems encountered in process control. In practical applications of feedback control, time delay arises frequently and can severely degrade closed-loop system performance and in some cases, drives the system to instability. Therefore, stability analysis and controller synthesis for uncertain nonlinear time-delay systems are important both in theory and in practice and many analytical techniques have been developed using delay-dependent Lyapunov function. In the past decade the magnetic and levitation (maglev) transportation system as a new system with high functionality has been the focus of numerous studies. However, maglev transportation systems are highly nonlinear and thus designing controller for those are challenging. The main topic of this paper is to design an adaptive robust controller for maglev transportation systems with time-delay, parametric uncertainties and external disturbances. In this paper, an adaptive robust control (ARC) is designed for this purpose. It should be noted that the adaptive gain is derived from Lyapunov-Krasovskii synthesis method, therefore asymptotic stability is guaranteed.

  3. Superconducting levitation applications to bearings and magnetic transportation

    CERN Document Server

    Moon, Francis C

    1994-01-01

    Presents the fundamental principles governing levitation of material bodies by magnetic fields without too much formal theory. Defines the technology of magnetic bearings, especially those based on superconductivity, and demonstrates the key roles that magnetics, mechanics and dynamics play in the complete understanding of magnetic levitation and its bearings. Features extensive figures and photos of Mag-Lev devices and summarizes recent U.S. research studies in an effort to regain the lead in Mag-Lev technologies

  4. Electromagnetic fields in small systems from a multiphase transport model

    Science.gov (United States)

    Zhao, Xin-Li; Ma, Yu-Gang; Ma, Guo-Liang

    2018-02-01

    We calculate the electromagnetic fields generated in small systems by using a multiphase transport (AMPT) model. Compared to A +A collisions, we find that the absolute electric and magnetic fields are not small in p +Au and d +Au collisions at energies available at the BNL Relativistic Heavy Ion Collider and in p +Pb collisions at energies available at the CERN Large Hadron Collider. We study the centrality dependencies and the spatial distributions of electromagnetic fields. We further investigate the azimuthal fluctuations of the magnetic field and its correlation with the fluctuating geometry using event-by-event simulations. We find that the azimuthal correlation 〈" close="〉cos(ϕα+ϕβ-2 ΨRP)〉">cos2 (ΨB-Ψ2) between the magnetic field direction and the second-harmonic participant plane is almost zero in small systems with high multiplicities, but not in those with low multiplicities. This indicates that the charge azimuthal correlation is not a valid probe to study the chiral magnetic effect (CME) in small systems with high multiplicities. However, we suggest searching for possible CME effects in small systems with low multiplicities.

  5. The WIPP transportation system: Demonstrated readiness

    International Nuclear Information System (INIS)

    Ward, T.R.; Spooner, R.

    1991-01-01

    The Department of Energy (DOE) has developed an integrated transportation system to transport transuranic (TRU) waste from ten widely-dispersed generator sites to the Waste Isolation Pilot Plant (WIPP). The system consists of a Type B container, a specially- designed trailer, a lightweight tractor, the DOE ''TRANSCOM'' vehicle tracking system, and uniquely qualified and highly-trained drivers. In June of 1989, the National Academy of Sciences reviewed the transportation system and concluded that: ''The system proposed for transportation of TRU waste to WIPP is safer than that employed for any other hazardous material in the United States today and will reduce risk to very low levels'' (emphasis added). The next challenge facing the DOE was demonstrating that this system was ready to transport the TRU waste to the WIPP site efficiently and in the safest manner possible. Not only did the DOE feel that is was necessary to convince itself that the system was safe, but also representatives of the 20 states through which it would travel

  6. The WIPP transportation system: Demonstrated readiness

    International Nuclear Information System (INIS)

    Ward, T.R.; Spooner, R.

    1991-01-01

    The Department of Energy (DOE) has developed an integrated transportation system to transport transuranic (TRU) waste from ten widely-dispersed generator sites to the Waste Isolation Pilot Plant (WIPP). The system consists of a Type B container, a specially-designed trailer, a lightweight tractor, the DOE ''TRANSCOM'' vehicle tracing system, and uniquely qualified and highly-trained drivers. In June of 1989, the National Academy of Sciences reviewed the transportation system and concluded that: ''The system proposed for transportation of TRU waste to WIPP is safer than that employed for any other hazardous material in the United States today and will reduce risk to very low levels.'' The next challenge facing the DOE was demonstrating that this system was ready to transport the TRU waste to the WIPP site in the safest manner possible. Not only did the DOE feel that it was necessary to convince itself that the system was safe, but also representatives of the 23 states through which it traveled

  7. 49 CFR 37.25 - University transportation systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false University transportation systems. 37.25 Section 37.25 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.25 University transportation systems. (a...

  8. Construction of Superconducting Magnet System for the J-PARC Neutrino Beam Line

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, T.; Wanderer, P.; Sasaki, K.; Ajima, Y.; Araoka, O.; Fujii, Y.; Hastings, N.; Higashi, N.; Iida, M.; Ishii, T.; Kimura, N.; Kobayashi, T.; Makida, Y.; Nakadaira, T.; Ogitsu, T.; Ohhata, H.; Okamura, T.; Sakashita, K.; Sugawara, S.; Suzuki, S.; Tanaka, K.; Tomaru, T.; Terashima, A.; Yamamoto, A.; Ichikawa, A.; Kakuno, H.; Anerella, M.; Escallier, J.; Ganetis, G.; gupta, R.; Jain, A.; Muratore, J.; Parker, B.; Boussuge, T.; Charrier, J.-P.; Arakawa, M.; Ichihara, T.; Minato, T.; Okada, Y.; Itou, A.; Kumaki, T.; Nagami, M.; Takahashi, T.

    2009-10-18

    Following success of a prototype R&D, construction of a superconducting magnet system for J-PARC neutrino beam line has been carried out since 2005. A new conceptual beam line with the superconducting combined function magnets demonstrated the successful beam transport to the neutrino production target.

  9. Anomalous transport of charged dust grains in a magnetized collisional plasma: A molecular dynamics study

    Science.gov (United States)

    Bezbaruah, Pratikshya; Das, Nilakshi

    2018-05-01

    Anomalous diffusion of charged dust grains immersed in a plasma in the presence of strong ion-neutral collision, flowing ions, and a magnetic field has been observed. Molecular Dynamics simulation confirms the deviation from normal diffusion in an ensemble of dust grains probed in laboratory plasma chambers. Collisional effects are significant in governing the nature of diffusion. In order to have a clear idea on the transport of particles in a real experimental situation, the contribution of streaming ions and the magnetic field along with collision is considered through the relevant interaction potential. The nonlinear evolution of Mean Square Displacement is an indication of the modification in particle trajectories due to several effects as mentioned above. It is found that strong collision and ion flow significantly affect the interparticle interaction potential in the presence of the magnetic field and lead to the appearance of the asymmetric type of Debye Hückel (D H) potential. Due to the combined effect of the magnetic field, ion flow, and collision, dusty plasma exhibits a completely novel behavior. The coupling parameter Γ enhances the asymmetric D H type potential arising due to ion flow, and this may drive the system to a disordered state.

  10. Quantum Transport in Mesoscopic Systems

    Indian Academy of Sciences (India)

    voltage bias, the tunneling of the electron from the lead to the dot and vice versa will happen very rarely. Then two successive ..... A typical mesoscopic quantum dot system (a small drop- .... dynamical behavior of the distribution function of the.

  11. Permanent-magnet-less synchronous reluctance system

    Science.gov (United States)

    Hsu, John S

    2012-09-11

    A permanent magnet-less synchronous system includes a stator that generates a magnetic revolving field when sourced by an alternating current. An uncluttered rotor is disposed within the magnetic revolving field and spaced apart from the stator to form an air gap relative to an axis of rotation. The rotor includes a plurality of rotor pole stacks having an inner periphery biased by single polarity of a north-pole field and a south-pole field, respectively. The outer periphery of each of the rotor pole stacks are biased by an alternating polarity.

  12. Underwater Animal Monitoring Magnetic Sensor System

    KAUST Repository

    Kaidarova, Altynay

    2017-10-01

    Obtaining new insights into the behavior of free-living marine organisms is fundamental for conservation efforts and anticipating the impact of climate change on marine ecosystems. Despite the recent advances in biotelemetry, collecting physiological and behavioral parameters of underwater free-living animals remains technically challenging. In this thesis, we develop the first magnetic underwater animal monitoring system that utilizes Tunnel magnetoresistance (TMR) sensors, the most sensitive solid-state sensors today, coupled with flexible magnetic composites. The TMR sensors are composed of CoFeB free layers and MgO tunnel barriers, patterned using standard optical lithography and ion milling procedures. The short and long-term stability of the TMR sensors has been studied using statistical and Allan deviation analysis. Instrumentation noise has been reduced using optimized electrical interconnection schemes. We also develop flexible NdFeB-PDMS composite magnets optimized for applications in corrosive marine environments, and which can be attached to marine animals. The magnetic and mechanical properties are studied for different NdFeB powder concentrations and the performance of the magnetic composites for different exposure times to sea water is systematically investigated. Without protective layer, the composite magnets loose more than 50% of their magnetization after 51 days in seawater. The durability of the composite magnets can be considerably improved by using polymer coatings which are protecting the composite magnet, whereby Parylene C is found to be the most effective solution, providing simultaneously corrosion resistance, flexibility, and enhanced biocompatibility. A Parylene C film of 2μm thickness provides the sufficient protection of the magnetic composite in corrosive aqueous environments for more than 70 days. For the high level performance of the system, the theoretically optimal position of the composite magnets with respect to the sensing

  13. A magnet system for HEP experiments

    CERN Document Server

    Gaddi, A

    2012-01-01

    This chapter describes the sequence of steps that lead to the design of a magnet system for modern HEP detectors. We start looking to the main types of magnets used in HEP experiments, along with some basic formulae to set the main parameters, such as ampere-turns, impedance and stored energy. A section is dedicated to the description of the iron yoke, with emphasis on magnet-detector integration and assembly, steel characteristics, stray field issues and alternative design. In the second part of the chapter we start looking at a brief history of superconducting magnets and a comparison between warm and superconducting ones. Following that, we describe the commonly used superconducting cables, the conductor design and technology and the winding techniques. A section of the chapter is dedicated to the cryogenic design, vacuum insulation and other ancillary systems. We also describe the power circuit, with the power supply unit, the current leads, the current measurement devices and other instruments and safety...

  14. Magnetic resonance microscopy of iron transport in methanogenic granules

    Science.gov (United States)

    Bartacek, Jan; Vergeldt, Frank J.; Gerkema, Edo; Jenicek, Pavel; Lens, Piet N. L.; Van As, Henk

    2009-10-01

    Interactions between anaerobic biofilms and heavy metals such as iron, cobalt or nickel are largely unknown. Magnetic resonance imaging (MRI) is a non-invasive method that allows in situ studies of metal transport within biofilm matrixes. The present study investigates quantitatively the penetration of iron (1.75 mM) bound to ethylenediaminetetraacetate (EDTA) into the methanogenic granules (spherical biofilm). A spatial resolution of 109 × 109 × 218 μm 3 and a temporal resolution of 11 min are achieved with 3D Turbo Spin Echo (TSE) measurements. The longitudinal relaxivity, i.e. the slope the dependence of the relaxation rate (1/ T1) on the concentration of paramagnetic metal ions, was used to measure temporal changes in iron concentration in the methanogenic granules. It took up to 300 min for the iron-EDTA complex ([FeEDTA] 2-) to penetrate into the methanogenic granules (3-4 mm in diameter). The diffusion was equally fast in all directions with irregularities such as diffusion-facilitating channels and diffusion-resistant zones. Despite these irregularities, the overall process could be modeled using Fick's equations for diffusion in a sphere, because immobilization of [FeEDTA] 2- in the granular matrix (or the presence of a reactive barrier) was not observed. The effective diffusion coefficient ( D ejf) of [FeEDTA] 2- was found to be 2.8 × 10 -11 m 2 s -1, i.e. approximately 4% of D ejf of [FeEDTA] 2- in water. The Fickian model did not correspond to the processes taking place in the core of the granule (3-5% of the total volume of the granule), where up to 25% over-saturation by iron (compare to the concentration in the bulk solution) occurred.

  15. Possible effects of drift wave turbulence on magnetic structure and plasma transport in tokamaks

    International Nuclear Information System (INIS)

    Callen, J.D.

    1977-07-01

    A new mechanism is proposed by which low level, drift wave type fluctuations, such as those observed in the ATC and TFR experiments, can cause anomalous radial electron heat transport in tokamaks. The model is based on the fact that since transport processes parallel to the magnetic field are many orders of magnitude more rapid than perpendicular ones, very small helically resonant magnetic perturbations that cause field lines to move radially allow the parallel transport process to contribute to radial electron heat transport. It is hypothesized that the small magnetic perturbations accompanying drift waves at any nonzero plasma β are large enough to produce significant effects in present tokamak experiments. The helical magnetic component of drift waves produces magnetic island structures whose spatial widths can easily exceed the ion gyroradius. In a drift wave oscillation period, electrons circumnavigate a magnetic island, whereas the slower moving ions see only a tilt of the magnetic field lines. Thus, electrons try to diffuse radially more rapidly than ions; however, a radialpotential builds up on a very short time scale to confine the electrons electrostatically and thereby keep the particle diffusion ambipolar. Nonetheless, this parallel electron diffusion process does cause net radial electron heat conduction through an ensemble of closely packed island structures. The heat conduction coefficient is estimated. Other effects that these magnetic flutters may have on plasma transport and runaway electron processes are also discussed

  16. Inactive trials of transport systems: phase II

    International Nuclear Information System (INIS)

    Haberlin, M.M.; Hardy, A.R.; Kennedy, S.T.

    1986-11-01

    Progress made during 1984-85 is reviewed in four sections: the design and installation of a stainless steel working floor in the mock-up of a crate handling and size reduction facility; the detailed evaluation of a single air pad of the type used on commercial air-transporter; an experimental programme designed to examine the problems associated with the operation of a commercial air-transporter; the design, manufacture and commissioning trials of two powered conveyor units which when combined complete a remotely operated transfer system for transporting crated waste into and within the mock-up facility. (author)

  17. Role of E x B Shear and Magnetic Shear in the Formation of Transport Barriers in DIII-D

    International Nuclear Information System (INIS)

    Burrell, K.H.

    2005-01-01

    Development of the E x B shear stabilization model to explain the formation of transport barriers in magnetic confinement devices is a major achievement of fusion research. This concept has the universality needed to explain the H-mode edge transport barriers seen in limiter and divertor tokamaks, stellarators, and mirror machines; the broader edge transport barrier seen in VH-mode plasmas; and the core transport barriers formed in tokamaks with low or negative magnetic shear. These examples of confinement improvement are of considerable physical interest; it is not often that a system self-organizes to reduce transport when an additional source of free energy is applied to it. The transport decrease associated with E x B velocity shear is also of great practical benefit to fusion research. The fundamental physics involved in transport reduction is the effect of E x B shear on the growth, radial extent, and phase correlation of turbulent eddies in the plasma. The same basic transport reduction process can be operational in various portions of the plasma because there are a number of ways to change the radial electric field E r . An important theme in this area is the synergistic effect of E x B velocity shear and magnetic shear. Although the E x B velocity shear appears to have an effect on broader classes of microturbulence, magnetic shear can mitigate some potentially harmful effects of E x B velocity shear and facilitate turbulence stabilization. The experimental results on DIII-D and other devices are generally consistent with the basic theoretical models

  18. A novel numerical method for the analysis of electron transport in the presence of pointlike magnetic scatterers

    International Nuclear Information System (INIS)

    Miyagawa, Yuu; Ueta, Tsuyoshi

    2008-01-01

    The boundary element method (BEM) is so extended as to treat two-dimensional (2D) electron systems in the presence of pointlike islands of magnetic moment. In the present paper, the pointlike magnetic scatterer is modeled by a cylindrical barrier. The radius of the cylindrical barrier is assumed to be so small, keeping the volume definite, that the pointlike magnetic scatterer is approximated by a Dirac δ function. Then, we make an approximation on the BEM formulation, wherefore we derive a novel numerical method for electron transport in the presence of pointlike magnetic scatterers. In a numerical implementation of the method extended here, the numerical errors of probability conservation are less than 1% for any cases and the computational costs, that is, the required memory amount and CPU time, are much reduced. As examples, the proposed method is applied to transport problems through a quantum wire with four pointlike magnetic scatterers. It is clearly shown that magnetic scatterers, even pointlike magnetic moments, lead to spin flip-flop, localization and resonance

  19. Magnet system studies for the Zeus experiment

    International Nuclear Information System (INIS)

    Baynham, D.E.; Coombs, R.C.; Uden, C.N.

    1985-11-01

    The ZEUS experiment will be mounted at the HERA accelerator complex currently under construction at DESY, Hamburg. A large volume of magnetic field will be required for charge selection of particles and track fitting. Two superconducting magnet systems which meet the parameters of the ZEUS Experiment are described; a small solenoid with good radiation transparency and a large aperture Helmholtz coil configuration. Basic design concepts and parameters are presented. (author)

  20. Not planning a sustainable transport system

    International Nuclear Information System (INIS)

    Finnveden, Göran; Åkerman, Jonas

    2014-01-01

    The overall objective of the Swedish transport policy is to ensure the economically efficient and sustainable provision of transport services for people and business throughout the country. More specifically, the transport sector shall, among other things, contribute to the achievement of environmental quality objectives in which the development of the transport system plays an important role in the achievement of the objectives. The aim of this study is to analyse if current transport planning supports this policy. This is done by analysing two recent cases: the National Infrastructure Plan 2010–2021, and the planning of Bypass Stockholm, a major road investment. Our results show that the plans are in conflict with several of the environmental quality objectives. Another interesting aspect of the planning processes is that the long-term climate goals are not included in the planning processes, neither as a clear goal nor as factor that will influence future transport systems. In this way, the long-term sustainability aspects are not present in the planning. We conclude that the two cases do not contribute to a sustainable transport system. Thus, several changes must be made in the processes, including putting up clear targets for emissions. Also, the methodology for the environmental assessments needs to be further developed and discussed. - Highlights: • Two cases are studied to analyse if current planning supports a sustainable transport system. • Results show that the plans are in conflict with several of the environmental quality objectives. • Long-term climate goals are not included in the planning processes. • Current practices do not contribute to a sustainable planning processes. • Methodology and process for environmental assessments must be further developed and discussed

  1. Not planning a sustainable transport system

    Energy Technology Data Exchange (ETDEWEB)

    Finnveden, Göran, E-mail: goran.finnveden@abe.kth.se; Åkerman, Jonas

    2014-04-01

    The overall objective of the Swedish transport policy is to ensure the economically efficient and sustainable provision of transport services for people and business throughout the country. More specifically, the transport sector shall, among other things, contribute to the achievement of environmental quality objectives in which the development of the transport system plays an important role in the achievement of the objectives. The aim of this study is to analyse if current transport planning supports this policy. This is done by analysing two recent cases: the National Infrastructure Plan 2010–2021, and the planning of Bypass Stockholm, a major road investment. Our results show that the plans are in conflict with several of the environmental quality objectives. Another interesting aspect of the planning processes is that the long-term climate goals are not included in the planning processes, neither as a clear goal nor as factor that will influence future transport systems. In this way, the long-term sustainability aspects are not present in the planning. We conclude that the two cases do not contribute to a sustainable transport system. Thus, several changes must be made in the processes, including putting up clear targets for emissions. Also, the methodology for the environmental assessments needs to be further developed and discussed. - Highlights: • Two cases are studied to analyse if current planning supports a sustainable transport system. • Results show that the plans are in conflict with several of the environmental quality objectives. • Long-term climate goals are not included in the planning processes. • Current practices do not contribute to a sustainable planning processes. • Methodology and process for environmental assessments must be further developed and discussed.

  2. Transportable Vitrification System Demonstration on Mixed Waste

    International Nuclear Information System (INIS)

    Zamecnik, J.R.; Whitehouse, J.C.; Wilson, C.N.; Van Ryn, F.R.

    1998-01-01

    This paper describes preliminary results from the first demonstration of the Transportable Vitrification System (TVS) on actual mixed waste. The TVS is a fully integrated, transportable system for the treatment of mixed and low-level radioactive wastes. The demonstration was conducted at Oak Ridge's East Tennessee Technology Park (ETTP), formerly known as the K-25 site. The purpose of the demonstration was to show that mixed wastes could be vitrified safely on a 'field' scale using joule-heated melter technology and obtain information on system performance, waste form durability, air emissions, and costs

  3. Pathogen transport in groundwater systems: contrasts with traditional solute transport

    Science.gov (United States)

    Hunt, Randall J.; Johnson, William P.

    2017-06-01

    Water quality affects many aspects of water availability, from precluding use to societal perceptions of fit-for-purpose. Pathogen source and transport processes are drivers of water quality because they have been responsible for numerous outbreaks resulting in large economic losses due to illness and, in some cases, loss of life. Outbreaks result from very small exposure (e.g., less than 20 viruses) from very strong sources (e.g., trillions of viruses shed by a single infected individual). Thus, unlike solute contaminants, an acute exposure to a very small amount of contaminated water can cause immediate adverse health effects. Similarly, pathogens are larger than solutes. Thus, interactions with surfaces and settling become important even as processes important for solutes such as diffusion become less important. These differences are articulated in "Colloid Filtration Theory", a separate branch of pore-scale transport. Consequently, understanding pathogen processes requires changes in how groundwater systems are typically characterized, where the focus is on the leading edges of plumes and preferential flow paths, even if such features move only a very small fraction of the aquifer flow. Moreover, the relatively short survival times of pathogens in the subsurface require greater attention to very fast (solute transport mechanisms discussed here, a more encompassing view of water quality and source water protection is attained. With this more holistic view and theoretical understanding, better evaluations can be made regarding drinking water vulnerability and the relation between groundwater and human health.

  4. Advanced public transportation systems : evaluation guidelines

    Science.gov (United States)

    1994-01-01

    The Federal Transit Administration has developed the Advanced Public Transportation Systems (APTS) Program which is an integral part of the overall U.S. DOT Intelligent Vehicle Highway Systems (IVHS) effort. A major aim of the APTS Program is to prom...

  5. Transport coefficients for electrons in argon in crossed electric and magnetic rf fields

    International Nuclear Information System (INIS)

    Raspopovic, Z M; Dujko, S; Makabe, T; Petrovic, Z Lj

    2005-01-01

    Monte Carlo simulations of electron transport have been performed in crossed electric and magnetic rf fields in argon. It was found that a magnetic field strongly affects electron transport, producing complex behaviour of the transport coefficients that cannot be predicted on the basis of dc field theory. In particular, it is important that a magnetic field, if it has sufficiently high amplitude, allows energy gain from the electric field only over a brief period of time, which leads to a pulse of directed motion and consequently to cyclotron oscillations being imprinted on the transport coefficients. Furthermore, this may lead to negative diffusion. The behaviour of drift velocities is also interesting, with a linear (sawtooth) dependence for the perpendicular drift velocity and bursts of drift for the longitudinal. Non-conservative effects are, on the other hand, reduced by the increasing magnetic field

  6. Progress of magnetic-suspension systems and magnetic bearings in the USSR

    International Nuclear Information System (INIS)

    Kuzin, A.V.

    1992-01-01

    This paper traces the development and progress of magnetic suspension systems and magnetic bearings in the USSR. The paper describes magnetic bearings for turbomachines, magnetic suspension systems for vibration isolation, some special measuring devices, wind tunnels, and other applications. The design, principles of operation, and dynamic characteristics of the system are presented

  7. Carbon transport in sodium systems

    International Nuclear Information System (INIS)

    Martin Espigares, M.; Lapena, J.; La Torre, M. de

    1983-01-01

    Carbon activities in dynamic non isothermal sodium system are determined using an equilibratium method. Foils of Fe-18 w% Cr-8 W% Ni alloy with low carbon content (in the as received condition) are exposed to dynamic liquid sodium in the temperature range between 450 0 C and 700 0 C. The analysis was used to evaluate the carburization-decarburization behaviour of type 304 stainless steel exposed to sodium. (author)

  8. The Integrated Air Transportation System Evaluation Tool

    Science.gov (United States)

    Wingrove, Earl R., III; Hees, Jing; Villani, James A.; Yackovetsky, Robert E. (Technical Monitor)

    2002-01-01

    Throughout U.S. history, our nation has generally enjoyed exceptional economic growth, driven in part by transportation advancements. Looking forward 25 years, when the national highway and skyway systems are saturated, the nation faces new challenges in creating transportation-driven economic growth and wealth. To meet the national requirement for an improved air traffic management system, NASA developed the goal of tripling throughput over the next 20 years, in all weather conditions while maintaining safety. Analysis of the throughput goal has primarily focused on major airline operations, primarily through the hub and spoke system.However, many suggested concepts to increase throughput may operate outside the hub and spoke system. Examples of such concepts include the Small Aircraft Transportation System, civil tiltrotor, and improved rotorcraft. Proper assessment of the potential contribution of these technologies to the domestic air transportation system requires a modeling capability that includes the country's numerous smaller airports, acting as a fundamental component of the National Air space System, and the demand for such concepts and technologies. Under this task for NASA, the Logistics Management Institute developed higher fidelity demand models that capture the interdependence of short-haul air travel with other transportation modes and explicitly consider the costs of commercial air and other transport modes. To accomplish this work, we generated forecasts of the distribution of general aviation based aircraft and GA itinerant operations at each of nearly 3.000 airport based on changes in economic conditions and demographic trends. We also built modules that estimate the demand for travel by different modes, particularly auto, commercial air, and GA. We examined GA demand from two perspectives: top-down and bottom-up, described in detail.

  9. A model for the nonlocal transport and the associated distribution function deformation in magnetized laser-plasmas

    International Nuclear Information System (INIS)

    Nicolai, Ph.; Feugeas, J.L.; Schurtz, G.

    2006-01-01

    We present a model of nonlocal transport for multidimensional radiation magneto hydrodynamic codes. In laser-produced plasmas, it is now believed that the heat transfer can be strongly modified by the nonlocal nature of the electron conduction. Nevertheless other mechanisms as self generated magnetic fields may affect heat transport too. The model described in this work aims at extending the formula of G. Schurtz, Ph. Nicolai and M. Busquet to magnetized plasmas. A system of nonlocal equations is derived from kinetic equations with self-consistent electric and magnetic fields. These equations are analyzed and applied to a physical problem in order to demonstrate the main features of the model. This new model should improve the prediction and the interpretation of the laser experiments, in particular when the non-local model alone does not seem sufficient to reproduce the experimental results. This model is being implemented in a new 2-dimensional hydrodynamic code

  10. A model for the nonlocal transport and the associated distribution function deformation in magnetized laser-plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Nicolai, Ph.; Feugeas, J.L.; Schurtz, G. [Bordeaux-1 Univ., Centre Lasers Intenses et Applications (UMR 5107) CEA-CNRS, 33 - Talence (France)

    2006-06-15

    We present a model of nonlocal transport for multidimensional radiation magneto hydrodynamic codes. In laser-produced plasmas, it is now believed that the heat transfer can be strongly modified by the nonlocal nature of the electron conduction. Nevertheless other mechanisms as self generated magnetic fields may affect heat transport too. The model described in this work aims at extending the formula of G. Schurtz, Ph. Nicolai and M. Busquet to magnetized plasmas. A system of nonlocal equations is derived from kinetic equations with self-consistent electric and magnetic fields. These equations are analyzed and applied to a physical problem in order to demonstrate the main features of the model. This new model should improve the prediction and the interpretation of the laser experiments, in particular when the non-local model alone does not seem sufficient to reproduce the experimental results. This model is being implemented in a new 2-dimensional hydrodynamic code.

  11. Ba doped Fe3O4 nanocrystals: Magnetic field and temperature tuning dielectric and electrical transport

    Science.gov (United States)

    Dutta, Papia; Mandal, S. K.; Nath, A.

    2018-05-01

    Nanocrystalline BaFe2O4 has been prepared through low temperature pyrophoric reaction method. The structural, dielectric and electrical transport properties of BaFe2O4 are investigated in detail. AC electrical properties have been studied over the wide range of frequencies with applied dc magnetic fields and temperatures. The value of impedance is found to increase with increase in magnetic field attributing the magnetostriction property of the sample. The observed value of magneto-impedance and magnetodielectric is found to ∼32% and ∼33% at room temperature. Nyquist plots have been fitted using resistance-capacitor circuits at different magnetic fields and temperatures showing the dominant role of grain and grain boundaries of the sample. Metal-semiconductor transition ∼403 K has been discussed in terms of delocalized and localized charge carrier.We have estimated activation energy using Arrhenius relation indicating temperature dependent electrical relaxation process in the system. Ac conductivity follow a Jonscher’s single power law indicating the large and small polaronic hopping conduction mechanism in the system.

  12. LCLS-II CRYOMODULE TRANSPORT SYSTEM TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Naeem [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Daly, Edward F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); McGee, Michael W. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2018-04-01

    The Cryomodules (CM) for the Linear Coherent Light Source II (LCLS-II) will be shipped to SLAC (Menlo Park, California) from JLab (Newport News, Virginia) and FNAL (Batavia, Illinois). A transportation system has been designed and built to safely transport the CMs over the road. It uses an array of helical isolator springs to attenuate shocks on the CM to below 1.5g in all directions. The system rides on trailers equipped with Air-Ride suspension, which attenuates vibration loads. The prototype LCLS-II CM (pCM) was driven 750 miles to test the transport system; shock loggers recorded the shock attenuation on the pCM and vacuum gauges were used to detect any compromises in beamline vacuum. Alignment measurements were taken before and after the trip to check whether cavity positions had shifted beyond the ± 0.2mm spec. Passband frequencies and cavity gradients were measured at 2K at the Cryomodule Test Facility (CMTF) at JLab to identify any degradation of CM performance after transportation. The transport system was found to have safely carried the CM and is cleared to begin shipments from JLab and FNAL to SLAC.

  13. Theoretical validation for changing magnetic fields of systems of permanent magnets of drum separators

    Science.gov (United States)

    Lozovaya, S. Y.; Lozovoy, N. M.; Okunev, A. N.

    2018-03-01

    This article is devoted to the theoretical validation of the change in magnetic fields created by the permanent magnet systems of the drum separators. In the article, using the example of a magnetic separator for enrichment of highly magnetic ores, the method of analytical calculation of the magnetic fields of systems of permanent magnets based on the Biot-Savart-Laplace law, the equivalent solenoid method, and the superposition principle of fields is considered.

  14. Towards a Decentralized Magnetic Indoor Positioning System

    Science.gov (United States)

    Kasmi, Zakaria; Norrdine, Abdelmoumen; Blankenbach, Jörg

    2015-01-01

    Decentralized magnetic indoor localization is a sophisticated method for processing sampled magnetic data directly on a mobile station (MS), thereby decreasing or even avoiding the need for communication with the base station. In contrast to central-oriented positioning systems, which transmit raw data to a base station, decentralized indoor localization pushes application-level knowledge into the MS. A decentralized position solution has thus a strong feasibility to increase energy efficiency and to prolong the lifetime of the MS. In this article, we present a complete architecture and an implementation for a decentralized positioning system. Furthermore, we introduce a technique for the synchronization of the observed magnetic field on the MS with the artificially-generated magnetic field from the coils. Based on real-time clocks (RTCs) and a preemptive operating system, this method allows a stand-alone control of the coils and a proper assignment of the measured magnetic fields on the MS. A stand-alone control and synchronization of the coils and the MS have an exceptional potential to implement a positioning system without the need for wired or wireless communication and enable a deployment of applications for rescue scenarios, like localization of miners or firefighters. PMID:26690145

  15. Towards a Decentralized Magnetic Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Zakaria Kasmi

    2015-12-01

    Full Text Available Decentralized magnetic indoor localization is a sophisticated method for processing sampled magnetic data directly on a mobile station (MS, thereby decreasing or even avoiding the need for communication with the base station. In contrast to central-oriented positioning systems, which transmit raw data to a base station, decentralized indoor localization pushes application-level knowledge into the MS. A decentralized position solution has thus a strong feasibility to increase energy efficiency and to prolong the lifetime of the MS. In this article, we present a complete architecture and an implementation for a decentralized positioning system. Furthermore, we introduce a technique for the synchronization of the observed magnetic field on the MS with the artificially-generated magnetic field from the coils. Based on real-time clocks (RTCs and a preemptive operating system, this method allows a stand-alone control of the coils and a proper assignment of the measured magnetic fields on the MS. A stand-alone control and synchronization of the coils and the MS have an exceptional potential to implement a positioning system without the need for wired or wireless communication and enable a deployment of applications for rescue scenarios, like localization of miners or firefighters.

  16. Vibration Reduction System Using Magnetic Suspension Technology

    Directory of Open Access Journals (Sweden)

    Spychała Jarosław

    2015-01-01

    Full Text Available The article presents considerations concerning the construction of vibration reduction system using magnetic suspension technology. Presents the results of simulation, numerical and experimental the bearingless electric motor, for which successfully used this type of solution. Positive results of research and testing have become the basis for the development of the concept of building this type of active vibration reduction system , at the same time acting as a support for a technical object, which is a jet engine. Bearing failures are manifested by loss or distortion of their mass, which leads to a total destruction of the roller bearing, and thus reflected in the security. The article presents the concept of building active magnetic suspension to eliminate the bearing system of classical rolling bearing and replace it with magnetic bearing.

  17. Transport modeling: An artificial immune system approach

    Directory of Open Access Journals (Sweden)

    Teodorović Dušan

    2006-01-01

    Full Text Available This paper describes an artificial immune system approach (AIS to modeling time-dependent (dynamic, real time transportation phenomenon characterized by uncertainty. The basic idea behind this research is to develop the Artificial Immune System, which generates a set of antibodies (decisions, control actions that altogether can successfully cover a wide range of potential situations. The proposed artificial immune system develops antibodies (the best control strategies for different antigens (different traffic "scenarios". This task is performed using some of the optimization or heuristics techniques. Then a set of antibodies is combined to create Artificial Immune System. The developed Artificial Immune transportation systems are able to generalize, adapt, and learn based on new knowledge and new information. Applications of the systems are considered for airline yield management, the stochastic vehicle routing, and real-time traffic control at the isolated intersection. The preliminary research results are very promising.

  18. Collisional transport across the magnetic field in drift-fluid models

    DEFF Research Database (Denmark)

    Madsen, Jens; Naulin, Volker; Nielsen, Anders Henry

    2016-01-01

    Drift ordered fluid models are widely applied in studies of low-frequency turbulence in the edge and scrape-off layer regions of magnetically confined plasmas. Here, we show how collisional transport across the magnetic field is self-consistently incorporated into drift-fluid models without...

  19. Chrometric properties of curvilinear beam transport channels with reverses of longitudinal magnetic field

    International Nuclear Information System (INIS)

    Kapchinskij, M.I.; Korenev, I.L.; Roginskij, L.A.

    1990-01-01

    Dynamics of charged particle beams in curvilinear transport channels comprising sections with counter direction of longitudinal focusing magnetic field is considered. It is shown that such magnetic field reverses reduce sufficiently the particle deflections conditioned by momentum spread of longitudinal motion and their application allows one to completely project the achromatic channel

  20. The transport system for natural gas

    International Nuclear Information System (INIS)

    Bjoerndalen, Joergen; Nese, Gjermund

    2003-01-01

    In 2002, the actors on the Norwegian shelf in cooperation with the authorities established a new regime for sale and transport of gas. This article deals with some issues of interest relating to this new regime. The transport system for natural gas shows clear signs of being a natural monopoly, which makes it difficult to use the system efficiently. Two main problems of the current way of organizing are pointed out: (1) lack of price and market signals in capacity allocation and (2) unclear incentive effects. The article indicates a possible solution based on the form of organization that is used in the power market

  1. A demonstration of expert systems applications in transportation engineering : volume I, transportation engineers and expert systems.

    Science.gov (United States)

    1987-01-01

    Expert systems, a branch of artificial-intelligence studies, is introduced with a view to its relevance in transportation engineering. Knowledge engineering, the process of building expert systems or transferring knowledge from human experts to compu...

  2. Conflict simulation for surface transport systems

    International Nuclear Information System (INIS)

    Keeton, S.C.; De Laquil, P. III.

    1977-07-01

    An important element in the analysis of transportation safeguards systems is the determination of the outcome of an armed attack against the system. Such information is necessary to understand relationships among the various defender tactics, weapons systems, and adversary attributes. A battle model, SABRES, which can simulate safeguards engagements is under development. This paper briefly describes the first phase of SABRES and presents some examples of its capabilities

  3. LHC II system sensitivity to magnetic fluids

    CERN Document Server

    Cotae, Vlad

    2005-01-01

    Experiments have been designed to reveal the influences of ferrofluid treatment and static magnetic field exposure on the photosynthetic system II, where the light harvesting complex (LHC II) controls the ratio chlorophyll a/ chlorophyll b (revealing, indirectly, the photosynthesis rate). Spectrophotometric measurement of chlorophyll content revealed different influences for relatively low ferrofluid concentrations (10-30 mul/l) in comparison to higher concentrations (70-100 mul/l). The overlapped effect of the static magnetic field shaped better the stimulatory ferrofluid action on LHC II system in young poppy plantlets.

  4. Inductive voltage compensation in superconducting magnet systems

    International Nuclear Information System (INIS)

    Yeh, H.T.; Goddard, J.S.; Shen, S.S.

    1979-01-01

    This paper details several techniques of inductive voltage compensation developed for quench detection in superconducting magnet systems with multiple coils and power supplies, with particular application for the Large Coil Test Facility (LCTF). Sources of noise, their magnitudes, and the sensitivity required for normal zone detection to avoid damage to the magnets are discussed. Two passive compensation schemes (second difference and central difference) are introduced and illustrated by parameters of LCTF; these take advantage of coil symmetries and other system characteristics. An active compensation scheme based on current rate input fom pickup coils and utilizing theory on ac loss voltage for calibration was tested, and the experimental setup and test results are discussed

  5. Magnetic Thin Films for Perpendicular Magnetic Recording Systems

    Science.gov (United States)

    Sugiyama, Atsushi; Hachisu, Takuma; Osaka, Tetsuya

    In the advanced information society of today, information storage technology, which helps to store a mass of electronic data and offers high-speed random access to the data, is indispensable. Against this background, hard disk drives (HDD), which are magnetic recording devices, have gained in importance because of their advantages in capacity, speed, reliability, and production cost. These days, the uses of HDD extend not only to personal computers and network servers but also to consumer electronics products such as personal video recorders, portable music players, car navigation systems, video games, video cameras, and personal digital assistances.

  6. Wireless Communications in Smart Rail Transportation Systems

    Directory of Open Access Journals (Sweden)

    César Briso-Rodríguez

    2017-01-01

    Full Text Available Railway, subway, airplane, and other transportation systems have drawn an increasing interest on the use of wireless communications for critical and noncritical services to improve performance, reliability, and passengers experience. Smart transportation systems require the use of critical communications for operation and control, and wideband services can be provided using noncritical communications. High speed train (HST is one of the best test cases for the analysis of communication links and specification of the general requirements for train control and supervision, passenger communications, and onboard and infrastructure wireless sensors. In this paper, we analyze in detail critical and noncritical networks mainly using the HST as a test case. First, the different types of links for smart rail transportation are described, specifying the main requirements of the transportation systems, communications, and their applications for different services. Then, we propose a network architecture and requirements of the communication technologies for critical and noncritical data. Finally, an analysis is made for the future technologies, including the fifth-generation (5G communications, millimeter wave (mmWave, terahertz (THz, and satellites for critical and high-capacity communications in transportation.

  7. Magnetic Field Response Measurement Acquisition System

    Science.gov (United States)

    Woodard, Stanley E.; Taylor,Bryant D.; Shams, Qamar A.; Fox, Robert L.

    2007-01-01

    This paper presents a measurement acquisition method that alleviates many shortcomings of traditional measurement systems. The shortcomings are a finite number of measurement channels, weight penalty associated with measurements, electrical arcing, wire degradations due to wear or chemical decay and the logistics needed to add new sensors. Wire degradation has resulted in aircraft fatalities and critical space launches being delayed. The key to this method is the use of sensors designed as passive inductor-capacitor circuits that produce magnetic field responses. The response attributes correspond to states of physical properties for which the sensors measure. Power is wirelessly provided to the sensing element by using Faraday induction. A radio frequency antenna produces a time-varying magnetic field used to power the sensor and receive the magnetic field response of the sensor. An interrogation system for discerning changes in the sensor response frequency, resistance and amplitude has been developed and is presented herein. Multiple sensors can be interrogated using this method. The method eliminates the need for a data acquisition channel dedicated to each sensor. The method does not require the sensors to be near the acquisition hardware. Methods of developing magnetic field response sensors and the influence of key parameters on measurement acquisition are discussed. Examples of magnetic field response sensors and the respective measurement characterizations are presented. Implementation of this method on an aerospace system is discussed.

  8. 2-3D nonlocal transport model in magnetized laser plasmas.

    Science.gov (United States)

    Nicolaï, Philippe; Feugeas, Jean-Luc; Schurtz, Guy

    2004-11-01

    We present a model of nonlocal transport for multidimensional radiation magneto-hydrodynamics codes. This model, based on simplified Fokker-Planck equations, aims at extending the formulae of G Schurtz,Ph.Nicolaï and M. Busquet [Phys. Plasmas,7,4238 (2000)] to magnetized plasmas.The improvements concern various points as the electric field effects on nonlocal transport or conversely the kinetic effects on E field. However the main purpose of this work is to generalize the previous model by including magnetic field effects. A complete system of nonlocal equations is derived from kinetic equations with self-consistent E and B fields. These equations are analyzed and simplified in order to be implemented into large laser fusion codes and coupled to other relevent physics. Finally, our model allows to obtain the deformation of the electron distribution function due to nonlocal effects. This deformation leads to a non-maxwellian function which could be used to compute the influence on other physical processes.

  9. Three-Dimensional Design of a Non-Axisymmetric Periodic Permanent Magnet Focusing System

    CERN Document Server

    Chen Chi Ping; Radovinsky, Alexey; Zhou, Jing

    2005-01-01

    A three-dimensional (3D) design is presented of a non-axisymmetric periodic permanent magnet focusing system which will be used to focus a large-aspect-ratio, ellipse-shaped, space-charge-dominated electron beam. In this design, an analytic theory is used to specify the magnetic profile for beam transport. The OPERA3D code is used to compute and optimize a realizable magnet system. Results of the magnetic design are verified by two-dimensional particle-in-cell and three-dimensional trajectory simulations of beam propagation using PFB2D and OMNITRAK, respectively. Results of fabrication tolerance studies are discussed.

  10. Crew Transportation System Design Reference Missions

    Science.gov (United States)

    Mango, Edward J.

    2015-01-01

    Contains summaries of potential design reference mission goals for systems to transport humans to andfrom low Earth orbit (LEO) for the Commercial Crew Program. The purpose of this document is to describe Design Reference Missions (DRMs) representative of the end-to-end Crew Transportation System (CTS) framework envisioned to successfully execute commercial crew transportation to orbital destinations. The initial CTS architecture will likely be optimized to support NASA crew and NASA-sponsored crew rotation missions to the ISS, but consideration may be given in this design phase to allow for modifications in order to accomplish other commercial missions in the future. With the exception of NASA’s mission to the ISS, the remaining commercial DRMs are notional. Any decision to design or scar the CTS for these additional non-NASA missions is completely up to the Commercial Provider. As NASA’s mission needs evolve over time, this document will be periodically updated to reflect those needs.

  11. Magnon spin transport driven by the magnon chemical potential in a magnetic insulator

    NARCIS (Netherlands)

    Cornelissen, L J; Peters, K J H; Bauer, G. E. W.; Duine, R A; van Wees, B J

    2016-01-01

    We develop a linear-response transport theory of diffusive spin and heat transport by magnons in magnetic insulators with metallic contacts. The magnons are described by a position-dependent temperature and chemical potential that are governed by diffusion equations with characteristic relaxation

  12. Magnon spin transport driven by the magnon chemical in a magnetic insulator

    NARCIS (Netherlands)

    Cornelissen, L.J.; Peters, K.J.H.; Bauer, G.E.W.; Duine, R.A.; van Wees, B.J.

    2016-01-01

    We develop a linear-response transport theory of diffusive spin and heat transport by magnons in magnetic insulators with metallic contacts. The magnons are described by a position-dependent temperature and chemical potential that are governed by diffusion equations with characteristic relaxation

  13. Magnon spin transport driven by the magnon chemical potential in a magnetic insulator

    NARCIS (Netherlands)

    Cornelissen, L.J.; Peters, K. J H; Bauer, G.E.; Duine, R. A.; Van Wees, B. J.

    2016-01-01

    We develop a linear-response transport theory of diffusive spin and heat transport by magnons in magnetic insulators with metallic contacts. The magnons are described by a position-dependent temperature and chemical potential that are governed by diffusion equations with characteristic relaxation

  14. Magnon spin transport driven by the magnon chemical potential in a magnetic insulator

    NARCIS (Netherlands)

    Cornelissen, Ludo J.; Peters, Kevin J. H.; Duine, Rembert A.|info:eu-repo/dai/nl/304830127; Bauer, Gerrit E. W.; Wees, Bart J. van

    2016-01-01

    We develop a linear-response transport theory of diffusive spin and heat transport by magnons in magnetic insulators with metallic contacts. The magnons are described by a position dependent temperature and chemical potential that are governed by diffusion equations with characteristic relaxation

  15. Magnetic biosensor system to detect biological targets

    KAUST Repository

    Li, Fuquan; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2012-01-01

    magnetic concentration, magnetic as well as mechanical trapping and magnetic sensing. Target detection is based on the size difference between bare magnetic beads and magnetic beads with targets attached. This method remedies the need for a coating layer

  16. Change of the Magnetic-Field Topology by an Ergodic Divertor and the Effect on the Plasma Structure and Transport

    International Nuclear Information System (INIS)

    Jakubowski, M.W.; Schmitz, O.; Abdullaev, S.S.; Brezinsek, S.; Finken, K.H.; Kraemer-Flecken, A.; Lehnen, M.; Samm, U.; Unterberg, B.; Wolf, R.C.; Spatschek, K.H.

    2006-01-01

    The magnetic-field perturbation produced by the dynamic ergodic divertor in TEXTOR changes the topology of the magnetic field in the plasma edge, creating an open chaotic system. The perturbation spectrum contains only a few dominant harmonics and therefore it can be described by an analytical model. The modeling is performed in the vacuum approximation without assuming a backreaction of the plasma and does not rely on any experimentally obtained parameters. It is shown that this vacuum approximation predicts in many details the experimentally observed plasma structure. Several experiments have been performed to prove that the plasma edge behavior is defined mostly by the magnetic topology of the perturbed volume. The change in the transport can be explained with the knowledge of only the magnetic structures; i.e., the ergodic pattern dominates the plasma properties

  17. Mirror Fusion Test Facility magnet system

    International Nuclear Information System (INIS)

    VanSant, J.H.; Kozman, T.A.; Bulmer, R.H.; Ng, D.S.

    1981-01-01

    In 1979, R.H. Bulmer of Lawrence Livermore National Laboratory (LLNL) discussed a proposed tandem-mirror magnet system for the Mirror Fusion Test Facility (MFTF) at the 8th symposium on Engineering Problems in Fusion Research. Since then, Congress has voted funds for expanding LLNL's MFTF to a tandem-mirror facility (designated MFTF-B). The new facility, scheduled for completion by 1985, will seek to achieve two goals: (1) Energy break-even capability (Q or the ratio of fusion energy to plasma heating energy = 1) of mirror fusion, (2) Engineering feasibility of reactor-scale machines. Briefly stated, 22 superconducting magnets contained in a 11-m-diam by 65-m-long vacuum vessel will confine a fusion plasma fueled by 80 axial streaming-plasma guns and over 40 radial neutral beams. We have already completed a preliminary design of this magnet system

  18. Chitosan magnetic nanoparticles for drug delivery systems.

    Science.gov (United States)

    Assa, Farnaz; Jafarizadeh-Malmiri, Hoda; Ajamein, Hossein; Vaghari, Hamideh; Anarjan, Navideh; Ahmadi, Omid; Berenjian, Aydin

    2017-06-01

    The potential of magnetic nanoparticles (MNPs) in drug delivery systems (DDSs) is mainly related to its magnetic core and surface coating. These coatings can eliminate or minimize their aggregation under physiological conditions. Also, they can provide functional groups for bioconjugation to anticancer drugs and/or targeted ligands. Chitosan, as a derivative of chitin, is an attractive natural biopolymer from renewable resources with the presence of reactive amino and hydroxyl functional groups in its structure. Chitosan nanoparticles (NPs), due to their huge surface to volume ratio as compared to the chitosan in its bulk form, have outstanding physico-chemical, antimicrobial and biological properties. These unique properties make chitosan NPs a promising biopolymer for the application of DDSs. In this review, the current state and challenges for the application magnetic chitosan NPs in drug delivery systems were investigated. The present review also revisits the limitations and commercial impediments to provide insight for future works.

  19. Transport properties of magnetic atom bridges controlled by a scanning tunneling microscope

    International Nuclear Information System (INIS)

    Nakanishi, H.; Kishi, T.; Kasai, H.; Komori, F.; Okiji, A.

    2003-01-01

    We have investigated the transport and magnetic properties of the atom bridge made from magnetic materials, which is the atom-scale wire constructed between a scanning tunneling microscope (STM) tip and a solid surface, by the use of ab initio calculations. In the case of the twisted ladder structure atom bridge made of Fe, we have found that the magnetic state of the bridge changes from ferromagnetic to paramagnetic, as we compress the bridge in length. We report the spin dependent quantized conductance of the bridge. And we discuss the origin of a change in transport properties as we compress the bridge in length

  20. Developing intelligent transportation systems using the national ITS architecture: an executive edition for senior transportation managers

    Science.gov (United States)

    1998-02-01

    This document has been produced to provide senior transportation managers of state and local departments of transportation with practical guidance for deploying Intelligent Transportation Systems (ITS) consistent with the National ITS Architecture. T...

  1. Magnetic Launch Assist System Demonstration Test

    Science.gov (United States)

    2001-01-01

    Engineers at the Marshall Space Flight Center (MSFC) have been testing Magnetic Launch Assist Systems, formerly known as Magnetic Levitation (MagLev) technologies. To launch spacecraft into orbit, a Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at a very high speed. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, the launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This photograph shows a subscale model of an airplane running on the experimental track at MSFC during the demonstration test. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5- feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  2. Magnetic adatoms in two and four terminal graphene nanoribbons: A comparison between their spin polarized transport

    Science.gov (United States)

    Ganguly, Sudin; Basu, Saurabh

    2018-04-01

    We study the charge and spin transport in two and four terminal graphene nanoribbons (GNR) decorated with random distribution of magnetic adatoms. The inclusion of the magnetic adatoms generates only the z-component of the spin polarized conductance via an exchange bias in the absence of Rashba spin-orbit interaction (SOI), while in presence of Rashba SOI, one is able to create all the three (x, y and z) components. This has important consequences for possible spintronic applications. The charge conductance shows interesting behaviour near the zero of the Fermi energy. Where in presence of magnetic adatoms the familiar plateau at 2e2 / h vanishes, thereby transforming a quantum spin Hall insulating phase to an ordinary insulator. The local charge current and the local spin current provide an intuitive idea on the conductance features of the system. We found that, the local charge current is independent of Rashba SOI, while the three components of the local spin currents are sensitive to Rashba SOI. Moreover the fluctuations of the spin polarized conductance are found to be useful quantities as they show specific trends, that is, they enhance with increasing adatom densities. A two terminal GNR device seems to be better suited for possible spintronic applications.

  3. Progress with the Magnet Systems

    CERN Multimedia

    Miele, P

    B0 reaches 20.5 kA The B0 toroid model coil is a model of the BT coils with the same cross section and reduced length of 9 m. The same design and construction concepts have been implemented on B0 to validate the manufacturing technologies and concepts of the BT coils. The B0 realization is the result of a collaboration of CEA/INFN-LASA/CERN. A facility was built at CERN in order to test first the B0 model coil and thereafter the operation of the BT coils before installation. The infrastructure required to perform the tests includes a Helium refrigerator providing forced He flow for the cold mass and thermal shield cooling up to 100 g/s at 4.5 K and 60 K respectively; a 6V/24kA electrical system; the vacuum system able to provide 10-4 mbar; the safety system with appropriate quench protection unit and the systems for control and diagnostics. Because of its exceptional size, it is not feasible to assemble and test the BT as an integrated toroid on surface prior to underground installation. Therefore to repr...

  4. Differential privacy in intelligent transportation systems

    NARCIS (Netherlands)

    Kargl, Frank; Friedman, Arik; Boreli, Roksana

    2013-01-01

    In this paper, we investigate how the concept of differential privacy can be applied to Intelligent Transportation Systems (ITS), focusing on protection of Floating Car Data (FCD) stored and processed in central Traffic Data Centers (TDC). We illustrate an integration of differential privacy with

  5. Performance of the LHC magnet system

    CERN Document Server

    Parma, V

    2010-01-01

    The LHC magnet system, essentially composed of superconducting magnets operating at 1.9 K, has been largely commissioned in 2007-08. Before the serious incident of 19th September 2008, the magnet system was commissioned up to 7 kA (4 TeV proton beam energy); six (out of eight) sectors were commissioned up to 5.5 TeV and one up to 6.6 TeV. For more than one week, both beams have been injected, circulated and captured in the RF bucket, thus assessing the optics at injection energy. The incident in sector 3-4, originated by a serious defect of a high-current joint between magnets with large collateral damage, has changed the plans: 53 magnets in the damaged zone have been substituted or repaired meanwhile a campaign of consolidation is under way to allow safe restart of the accelerator in fall 2009. All these points and other issues presented and discussed, with emphasis on the incident in sector 3-4.

  6. Tuning of Transport and Magnetic Properties in Epitaxial LaMnO3+δ Thin Films

    Directory of Open Access Journals (Sweden)

    J. Chen

    2014-01-01

    Full Text Available The effect of compressive strain on the transport and magnetic properties of epitaxial LaMnO3+δ thin films has been investigated. It is found that the transport and magnetic properties of the LaMnO3+δ thin films grown on the LaAlO3 substrates can be tuned by the compressive strain through varying film thickness. And the insulator-metal transition, charge/orbital ordering transition, and paramagnetic-ferromagnetic transition are suppressed by the compressive strain. Consequently, the related electronic and magnetic transition temperatures decrease with an increase in the compressive strain. The present results can be explained by the strain-controlled lattice deformation and the consequent orbital occupation. It indicates that the lattice degree of freedom is crucial for understanding the transport and magnetic properties of the strongly correlated LaMnO3+δ.

  7. Turbulence and transport of passive scalar in magnetohydrodynamic channel flows with different orientations of magnetic field

    International Nuclear Information System (INIS)

    Dey, Prasanta K.; Zikanov, Oleg

    2012-01-01

    Highlights: ► Turbulent passive scalar transport in an MHD flow in a channel is studied using DNS. ► Magnetic fields of wall-normal, spanwise, and streamwise orientations are considered. ► Magnetic fields suppress turbulent transport and modifies scalar distribution. ► The effect is particularly strong at wall-normal and spanwise magnetic fields. ► Decrease of Nusselt number is approximated by a linear function of magnetic interaction parameter. - Abstract: DNS of turbulent flow and passive scalar transport in a channel are conducted for the situation when the fluid is electrically conducting (for example, a liquid metal) and the flow is affected by an imposed magnetic field. The cases of wall-normal, spanwise, and streamwise orientation of the magnetic field are considered. As main results, we find that the magnetic fields, especially those in the wall-normal and spanwise directions, significantly reduce the turbulent scalar transport and modify the properties of the scalar distribution.

  8. Advanced technologies for intelligent transportation systems

    CERN Document Server

    Picone, Marco; Amoretti, Michele; Zanichelli, Francesco; Ferrari, Gianluigi

    2015-01-01

    This book focuses on emerging technologies in the field of Intelligent Transportation Systems (ITSs) namely efficient information dissemination between vehicles, infrastructures, pedestrians and public transportation systems. It covers the state-of-the-art of Vehicular Ad-hoc Networks (VANETs), with centralized and decentralized (Peer-to-Peer) communication architectures, considering several application scenarios. With a detailed treatment of emerging communication paradigms, including cross networking  and distributed algorithms. Unlike most of the existing books, this book presents a multi-layer overview of information dissemination systems, from lower layers (MAC) to high layers (applications). All those aspects are investigated considering the use of mobile devices, such as smartphones/tablets and embedded systems, i.e. technologies that during last years completely changed the current market, the user expectations, and communication networks. The presented networking paradigms are supported and validate...

  9. Development of particle and heavy ion transport code system

    International Nuclear Information System (INIS)

    Niita, Koji

    2004-01-01

    Particle and heavy ion transport code system (PHITS) is 3 dimension general purpose Monte Carlo simulation codes for description of transport and reaction of particle and heavy ion in materials. It is developed on the basis of NMTC/JAM for design and safety of J-PARC. What is PHITS, it's physical process, physical models and development process of PHITC code are described. For examples of application, evaluation of neutron optics, cancer treatment by heavy particle ray and cosmic radiation are stated. JAM and JQMD model are used as the physical model. Neutron motion in six polar magnetic field and gravitational field, PHITC simulation of trace of C 12 beam and secondary neutron track of small model of cancer treatment device in HIMAC and neutron flux in Space Shuttle are explained. (S.Y.)

  10. Improved thermal isolation for superconducting magnet systems

    Science.gov (United States)

    Wiebe, E. R.

    1974-01-01

    Closed-cycle refrigerating system for superconductive magnet and maser is operated in vacuum environment. Each wire leading from external power source passes through cooling station which blocks heat conduction. In connection with these stations, switch with small incandescent light bulb, which generates heat, is used to stop superconduction.

  11. Magnetic particle clutch controls servo system

    Science.gov (United States)

    Fow, P. B.

    1973-01-01

    Magnetic clutches provide alternative means of driving low-power rate or positioning servo systems. They may be used over wide variety of input speed ranges and weigh comparatively little. Power drain is good with overall motor/clutch efficiency greater than 50 percent, and gain of clutch is close to linear, following hysteresis curve of core and rotor material.

  12. Simulating charge transport in flexible systems

    Directory of Open Access Journals (Sweden)

    Timothy Clark

    2015-12-01

    Full Text Available Systems in which movements occur on two significantly different time domains, such as organic electronic components with flexible molecules, require different simulation techniques for the two time scales. In the case of molecular electronics, charge transport is complicated by the several different mechanisms (and theoretical models that apply in different cases. We cannot yet combine time scales of molecular and electronic movement in simulations of real systems. This review describes our progress towards this goal.

  13. Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

    International Nuclear Information System (INIS)

    Molvik, A.W.; Kireeff Covo, M.; Cohen, R.; Coleman, J.; Sharp, W.; Bieniosek, F.; Friedman, A.; Roy, P.K.; Seidl, P.; Lund, S.M.; Faltens, A.; Vay, J.L.; Prost, L.

    2007-01-01

    The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam

  14. Sensorless magnetically levitated system with reduced observer

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, T [Inst. fuer Elektrische Maschinen, RWTH Aachen (Germany); Henneberger, G [Inst. fuer Elektrische Maschinen, RWTH Aachen (Germany); Ress, C [Inst. fuer Elektrische Maschinen, RWTH Aachen (Germany)

    1996-12-31

    The present paper describes the use of a reduced observer for a hybrid excited magnetic levitation system. The latter is part of a contactless and energy saving driven conveyance system. Thereby one has to select the working point of the system in such a way, that the force due to the weight of the vehicle including its load will be compensated only by the permanent magnets. The linearized model is observable even if only the current in the coils is measured. Therefore it seems reasonable to evaluate the other variables of the state vector by an observer. Thus the sensors for the airgap can be omitted. Using an observer has another advantage as well. It will tune the airgap automatically to the value which is necessary in order to operate the system in the most energy saving way. The whole design was simulated. (orig.)

  15. Shimadzu magnetic resonance imaging system, SMT-50

    International Nuclear Information System (INIS)

    Oikawa, Shiro; Nishida, Takayuki; Fujio, Yasuo

    1986-01-01

    The magnetic resonance imaging (MRI) system, as a new modality of medical imaging, has already been put to practical applications on many clinical sites, through which a lot of clinical data has been accumulated. It can offer a powerful new probe of internal anatomy of the human body and its functions. Now that the MRI has established its effectiveness in diagnosis, a really practical MRI system which features high efficiency and economical design with high patient throughput is strongly called for. Introduced in this article is a superconductive magnet MRI system, SMT-50, operating at 5000 Gauss. It has realized an excellent diagnostic capability with such functions as multi-slice multi-echo imaging, high sensitive, surface coil technique and so on. High resolution image display (1024 x 1024 pixcel) unit and separate console system (viewing console and scanning console) will assist high patient throughput. The outline of the SMT-50 and its clinical data are reported here. (author)

  16. Development of magnetic order in superconducting systems

    International Nuclear Information System (INIS)

    Moncton, D.E.; Shirane, G.; Thomlinson, W.

    1979-08-01

    Two different classes of rare-earth (RE) ternary superconductors (RERh 4 B 4 and REMo 6 S 8 , X=S, Se) have provided the first instances in which chemically ordered sublattices of magnetic ions exist in superconductors. Neutron scattering studies show that simple, conventional antiferromagnetism coexists with superconductivity in a number of systems, while destruction of superconductivity occurs with the onset of ferromagnetism. The magnetic structural details are summarized for the coexistent antiferromagnets, and review measurements on the superconducting → ferromagnetic transition in ErRh 4 B 4

  17. Nonlinear closure relations theory for transport processes in nonequilibrium systems

    International Nuclear Information System (INIS)

    Sonnino, Giorgio

    2009-01-01

    A decade ago, a macroscopic theory for closure relations has been proposed for systems out of Onsager's region. This theory is referred to as the thermodynamic field theory (TFT). The aim of this work was to determine the nonlinear flux-force relations that respect the thermodynamic theorems for systems far from equilibrium. We propose a formulation of the TFT where one of the basic restrictions, namely, the closed-form solution for the skew-symmetric piece of the transport coefficients, has been removed. In addition, the general covariance principle is replaced by the De Donder-Prigogine thermodynamic covariance principle (TCP). The introduction of TCP requires the application of an appropriate mathematical formalism, which is referred to as the entropy-covariant formalism. By geometrical arguments, we prove the validity of the Glansdorff-Prigogine universal criterion of evolution. A new set of closure equations determining the nonlinear corrections to the linear ('Onsager') transport coefficients is also derived. The geometry of the thermodynamic space is non-Riemannian. However, it tends to be Riemannian for high values of the entropy production. In this limit, we recover the transport equations found by the old theory. Applications of our approach to transport in magnetically confined plasmas, materials submitted to temperature, and electric potential gradients or to unimolecular triangular chemical reactions can be found at references cited herein. Transport processes in tokamak plasmas are of particular interest. In this case, even in the absence of turbulence, the state of the plasma remains close to (but, it is not in) a state of local equilibrium. This prevents the transport relations from being linear.

  18. Effect of magnetic islands on the impurity transport in a tokamak

    International Nuclear Information System (INIS)

    Ivanov, N.V.; Khvostenko, P.P.; Chudnovskij, A.N.

    1986-01-01

    Effect of magnetic islands m=2, created in plasma with the help of special quadrupole winding, on the behaviour of impurity in the T-7 tokamak is studied. The use of quadrupole winding permitted to exlude the magnetic island nonstationarity typical to spontaneous development of the Tiaring instability. The results obtained confirm the point of view that splitting of rational magnetic surface results in the change of impurity ion density gradient in its vicinity. This change occurs under the action of ambipolar electric field, that is excited due to the increase of radial electron transport in magnetic islands

  19. Electrical supply for MFTF-B superconducting magnet system

    International Nuclear Information System (INIS)

    Shimer, D.W.; Owen, E.W.

    1985-01-01

    The MFTF-B magnet system consists of 42 superconducting magnets which must operate continuously for long periods of time. The magnet power supply system is designed to meet the operational requirements of accuracy, flexibility, and reliability. The superconducting magnets require a protection system to protect against critical magnet faults of quench, current lead overtemperature, and overcurrent. The protection system is complex because of the large number of magnets, the strong coupling between magnets, and the high reliability requirement. This paper describes the power circuits and the components used in the design

  20. California air transportation study: A transportation system for the California Corridor of the year 2010

    Science.gov (United States)

    1989-01-01

    To define and solve the problems of transportation in the California Corrider in the year 2010, the 1989 California Polytechnic State University Aeronautical Engineering Senior Design class determined future corridor transportation needs and developed a system to meet the requirements. A market study, which included interpreting travel demand and gauging the future of regional and national air travel in and out of the corridor, allowed the goals of the project to be accurately refined. Comprehensive trade-off studies of several proposed transporation systems were conducted to determine which components would form the final proposed system. Preliminary design and further analysis were performed for each resulting component. The proposed system consists of three vehicles and a special hub or mode mixer, the Corridor Access Port (CAP). The vehicles are: (1) an electric powered aircraft to serve secondary airports and the CAP; (2) a high speed magnetic levitation train running through the CAP and the high population density areas of the corridor; and (3) a vertical takeoff and landing tilt rotor aircraft to serve both intercity and intrametropolitan travelers from the CAP and city vertiports. The CAP is a combination and an extension of the hub, mode mixer, and Wayport concepts. The CAP is an integrated part of the system which meets the travel demands in the corridor, and interfaces with interstate and international travel.

  1. Magnetic correlations in a classic Mott system

    International Nuclear Information System (INIS)

    Bao, W.; Broholm, C.; Aeppli, G.; Carter, S.A.; Dai, D.; Frost, C.D.

    1997-07-01

    The metal-insulator transition in V 2 O 3 causes a fundamental change in its magnetism. While the antiferromagnetic insulator (AFI) is a Heisenberg localized spin system, the antiferromagnetism in the strongly correlated metal is determined by a Fermi surface instability. Paramagnetic fluctuations in the metal and insulator represent similar spatial spin correlations, but are unrelated to the long range order in the AFI. The phase transition to the AFI induces an abrupt switching of magnetic correlations to a different magnetic wave vector. The AFI transition, therefore, is not a conventional spin order-disorder transition. Instead it is accounted for by an ordering in the occupation of the two degenerate d-orbitals at the Fermi level

  2. Large superconducting magnet systems for plasma and fusion applications

    International Nuclear Information System (INIS)

    Heinz, W.

    1976-05-01

    Work on superconducting magnet systems and state of the art of superconducting magnet technology are described. Conceptual design consideration and problems of large magnet systems (stability, magnetic forces, cooling modes, safety) are discussed. Recent results of experimental work at Karlsruhe are reported. An outline of American and European programs is given. (orig.) [de

  3. IOT Based Smart Public Transport System

    Directory of Open Access Journals (Sweden)

    Parag Gawade

    2017-07-01

    Full Text Available Internet of Things IoT joins the objects of this present reality to the virtual world and empowers at whatever time anyplace network for anything that has a turn ON and turn OFF switch. It constitutes to a world where physical things and humans and other living things and virtual information and situations collaborate with each other. Substantial measure of information is created as expansive number of gadgets is associated with the web. So this expansive measure of information must be controlled and changed over to helpful data keeping in mind the end goal to create productive frameworks. In this paper we concentrate on to a urban IoT framework that is utilized to construct Intelligent Transportation System ITS. IoT based intelligent transportation systems are intended to bolster the Smart City vision which intends to utilize the progressed and capable communication systems for the organization of the city and the residents.

  4. Enhancement of the efficiency of magnetic targeting for drug delivery: Development and evaluation of magnet system

    International Nuclear Information System (INIS)

    Cao Quanliang; Han Xiaotao; Li Liang

    2011-01-01

    Deep magnetic capture and clinical application are the current trends for magnetic targeted drug delivery system. More promising and possible strategies are needed to overcome the current limitations and further improve the magnetic targeting technique. Recent advances in the development of targeting magnet system show promise in progressing this technology from the laboratory to the clinic. Starting from well-known basic concepts, current limitations of magnetic targeted drug delivery system are analyzed. Meanwhile, the design concepts and evaluations of some effective improvements in magnet system are discussed and reviewed with reference to (i) reasonable design of magnet system; (ii) control modes of magnet system used to generate dynamical magnetic fields; and (iii) magnetic field driving types. - Research Highlights: → The current limitations of MTDDS for deep capture and clinical application are analyzed. → The development of magnet system shows promise in progressing MTDDS to clinical application. → The design concepts and evaluations of improvements in magnet system are reviewed and discussed. → The key to improve magnet system lies in controllable magnets and different excitations.

  5. Progress on axicell MFTF-B superconducting magnet systems

    International Nuclear Information System (INIS)

    Wang, S.T.; Kozman, T.A.; Hanson, C.L.; Shimer, D.W.; VanSant, J.H.; Zbasnik, J.

    1983-01-01

    Since the entire Mirror Fusion Test Facility (MFTF-B) Magnet System was reconfigured from the original A-cell to an axicell design, much progress has been made on the design, fabrication, and installation planning. The axicell MFTF-B magnet array consists of a total of 26 large superconducting main coils. This paper provides an engineering overview of the progress of these coils. Recent studies on the effects of field errors on the plasma at the recircularizing region (transition coils) show that small field errors will generate large displacements of the field lines. These field errors might enhance radial electron heat transport and deteriorate the plasma confinement. Therefore, 16 superconducting trim coils have been designed to correct the coil misalignments. Progress of the trim coils are reported also

  6. Magnetic fluctuations in heavy fermion systems

    International Nuclear Information System (INIS)

    Broholm, C.L.

    1989-06-01

    Magnetic order and fluctuations in the heavy Fermion systems UPt 3 , U 2 Zn 17 and URu 2 Si 2 have been studied by neutron scattering. Single crystalline samples and triple-axis neutron-scattering techniques with energy transfers between 0 and 40 meV and energy resolutions between 0.1 meV and 4 meV have been employed. UPt 3 develops an antiferromagnetically ordered moment of (0.02±0.005) μ B below T N = 5 K which doubles the unit cell in the basal plane and coexists with superconductivity below T c = 0.5 K. The magnetic fluctuations are relaxational, and enhanced at the antiferromagnetic zone center in a low-energy regime. The characteristic zone-center relaxation energy is 0.3 meV. The temperature- and field-dependence of the antiferromagnetic order in the superconducting phase suggest a close relation between these two properties in UPt 3 . U 2 Zn 17 has a broad spectrum of magnetic fluctuations, even below T N = 9.7 K, of which the transverse part below 10 meV is strongly enhanced at the antiferromagnetic zone center. The system has an anomalously extended critical region and the antiferromagnetic phase transition seems to be driven by the temperature-dependence of an effective RKKY interaction, as anticipated theoretically. URu 2 Si 2 , a strongly anisotropic heavy Fermion system, has a high-energy regime of antiferromagnetically-correlated overdamped magnetic fluctuations. Below T N = 17.5 K weak antiferromagnetic order, μ = (0.04±0.01)μ B , with finite correlations along the tetragonal c axis, develops along with a low-energy regime of strongly dispersive singlet-singlet excitations. Below T c = 1 K antiferromagnetism coexists with superconductivity. A phenomenological model describing the exchange-enhanced overdamped magnetic fluctuations of heavy Fermion systems is proposed. Our experimental results are compared to the anomalous bulk properties of heavy Fermion systems, and to magnetic fluctuations in other metallic magnets. (orig.)

  7. Automatic braking system modification for the Advanced Transport Operating Systems (ATOPS) Transportation Systems Research Vehicle (TSRV)

    Science.gov (United States)

    Coogan, J. J.

    1986-01-01

    Modifications were designed for the B-737-100 Research Aircraft autobrake system hardware of the Advanced Transport Operating Systems (ATOPS) Program at Langley Research Center. These modifications will allow the on-board flight control computer to control the aircraft deceleration after landing to a continuously variable level for the purpose of executing automatic high speed turn-offs from the runway. A bread board version of the proposed modifications was built and tested in simulated stopping conditions. Test results, for various aircraft weights, turnoff speed, winds, and runway conditions show that the turnoff speeds are achieved generally with errors less than 1 ft/sec.

  8. Effect of a static magnetic field on silicon transport in liquid phase diffusion growth of SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, University of Victoria, Victoria, BC V8W 3P6 (Canada)

    2010-03-15

    Liquid phase diffusion experiments have been performed without and with the application of a 0.4 T static magnetic field using a three-zone DC furnace system. SiGe crystals were grown from the germanium side for a period of 72 h. Experiments have led to the growth of single crystal sections varying from 0 to 10 mm thicknesses. Examination of the processed samples (single and polycrystalline sections) has shown that the effect of the applied static magnetic field is significant. It alters the temperature distribution in the system, reduces mass transport in the melt, and leads to a much lower growth rate. The initial curved growth interface was slightly flattened under the effect of magnetic field. There were no growth striations in the single crystal sections of the samples. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Guide to federal intelligent transportation system (ITS) research.

    Science.gov (United States)

    2013-01-01

    The U.S. Department of Transportations (USDOT) Intelligent Transportation System (ITS) Program aims to bring connectivity to transportation through the use of advanced wireless technologies powerful technologies that enable transformative chan...

  10. Operational Efficiency of Public Transport System in Kwara State ...

    African Journals Online (AJOL)

    Operational Efficiency of Public Transport System in Kwara State, Nigeria. ... The paper examines the operations of Public Transport in Nigeria using the Kwara State Transport Service as a case study. ... EMAIL FULL TEXT EMAIL FULL TEXT

  11. AC magnetic transport on heterogeneous ferromagnetic wires and tubes

    International Nuclear Information System (INIS)

    Sinnecker, J.P.; Pirota, K.R.; Knobel, M.; Kraus, L.

    2002-01-01

    The AC current density radial distribution is calculated on heterogeneous composite materials with cylindrical geometry. The composites have an inner core and thin outer shell that can be either from the same material (homogenous material like simple wires) or from different materials with different physical properties. The case in which a non-magnetic inner core is surrounded by a magnetic layer, like electrodeposited wires, is mainly studied. The effect of frequency and applied magnetic field is simulated. The current density distribution as a function of frequency and applied field, as well as the total current over the inner core and outer shells are calculated. The results agree substantially well with the experimentally observed data for simple electrodeposited wires

  12. Magnetic Transport Barriers in the DIII-D Tokamak

    Science.gov (United States)

    Kessler, J.; Volpe, F.; Evans, T. E.; Ali, H.; Punjabi, A.

    2009-11-01

    Large overlapping magnetic islands generate chaotic fields. However, a previous work [1] showed that second or third order perturbations of special topology and strength can also generate magnetic diffusion ``barriers" in the middle of stochastic regions. In the present study, we numerically assess their experimental feasibility at DIII-D. For this, realistic I- and C-coils perturbations are superimposed on the equilibrium field and puncture plots are generated with a field-line tracer. A criterion is defined for the automatic recognition of barriers and successfully tested on earlier symplectic maps in magnetic coordinates. The criterion is systematically applied to the new puncture plots in search for dependencies, e.g. upon the edge safety factor q95, which might be relevant to edge localized mode (ELM) stability, as well as to assess the robustness of barriers against fluctuations of the plasma parameters and coil currents. 8pt [1] H. Ali and A. Punjabi, Plasma Phys. Control. Fusion 49, 1565 (2007).

  13. Transport properties of graphene under periodic and quasiperiodic magnetic superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei-Tao, E-mail: luweitao@lyu.edu.cn [School of Science, Linyi University, 276005 Linyi (China); Institute of Condensed Matter Physics, Linyi University, 276005 Linyi (China); Wang, Shun-Jin [Department of Physics, Sichuan University, 610064 Chengdu (China); Wang, Yong-Long; Jiang, Hua [School of Science, Linyi University, 276005 Linyi (China); Institute of Condensed Matter Physics, Linyi University, 276005 Linyi (China); Li, Wen [School of Science, Linyi University, 276005 Linyi (China)

    2013-08-15

    We study the transmission of Dirac electrons through the one-dimensional periodic, Fibonacci, and Thue–Morse magnetic superlattices (MS), which can be realized by two different magnetic blocks arranged in certain sequences in graphene. The numerical results show that the transmission as a function of incident energy presents regular resonance splitting effect in periodic MS due to the split energy spectrum. For the quasiperiodic MS with more layers, they exhibit rich transmission patterns. In particular, the transmission in Fibonacci MS presents scaling property and fragmented behavior with self-similarity, while the transmission in Thue–Morse MS presents more perfect resonant peaks which are related to the completely transparent states. Furthermore, these interesting properties are robust against the profile of MS, but dependent on the magnetic structure parameters and the transverse wave vector.

  14. Lagrangian neoclassical transport theory applied to the region near the magnetic axis

    Energy Technology Data Exchange (ETDEWEB)

    Satake, Shinsuke [The Graduate Univ. for Advanced Studies, Dept. of Fusion Science, Toki, Gifu (Japan); Okamoto, Masao; Sugama, Hideo [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2002-06-01

    Neoclassical transport theory around the magnetic axis of a tokamak is studied, in which relatively wide ''potato'' orbits play an important role in transport. Lagrangian formulation of transport theory, which has been investigated to reflect finiteness of guiding-center orbit widths to transport equations, is developed in order to analyze neoclassical transport near the axis for a low-collisionality plasma. The treatment of self-collision term in Lagrangian formulation is revised to retain momentum conservation property of it. With directly reflecting the orbital properties of all the types of orbits in calculation, the ion thermal conductivity around the axis is found to decrease than from that predicted by conventional neoclassical theory. This result supports recent numerical simulations which show the reduction of thermal conductivity near the magnetic axis. (author)

  15. Lagrangian neoclassical transport theory applied to the region near the magnetic axis

    International Nuclear Information System (INIS)

    Satake, Shinsuke; Okamoto, Masao; Sugama, Hideo

    2002-01-01

    Neoclassical transport theory around the magnetic axis of a tokamak is studied, in which relatively wide 'potato' orbits play an important role in transport. Lagrangian formulation of transport theory, which has been investigated to reflect finiteness of guiding-center orbit widths to transport equations, is developed in order to analyze neoclassical transport near the axis for a low-collisionality plasma. The treatment of self-collision term in Lagrangian formulation is revised to retain momentum conservation property of it. By directly reflecting the orbital properties of all the types of orbits in calculation, the ion thermal conductivity around the axis is found to decrease from that predicted by conventional neoclassical theory. This result supports recent numerical simulations which show the reduction of thermal conductivity near the magnetic axis

  16. Lagrangian neoclassical transport theory applied to the region near the magnetic axis

    International Nuclear Information System (INIS)

    Satake, Shinsuke; Okamoto, Masao; Sugama, Hideo

    2002-06-01

    Neoclassical transport theory around the magnetic axis of a tokamak is studied, in which relatively wide ''potato'' orbits play an important role in transport. Lagrangian formulation of transport theory, which has been investigated to reflect finiteness of guiding-center orbit widths to transport equations, is developed in order to analyze neoclassical transport near the axis for a low-collisionality plasma. The treatment of self-collision term in Lagrangian formulation is revised to retain momentum conservation property of it. With directly reflecting the orbital properties of all the types of orbits in calculation, the ion thermal conductivity around the axis is found to decrease than from that predicted by conventional neoclassical theory. This result supports recent numerical simulations which show the reduction of thermal conductivity near the magnetic axis. (author)

  17. Stochastic transport processes in discrete biological systems

    CERN Document Server

    Frehland, Eckart

    1982-01-01

    These notes are in part based on a course for advanced students in the applications of stochastic processes held in 1978 at the University of Konstanz. These notes contain the results of re­ cent studies on the stochastic description of ion transport through biological membranes. In particular, they serve as an introduction to an unified theory of fluctuations in complex biological transport systems. We emphasize that the subject of this volume is not to introduce the mathematics of stochastic processes but to present a field of theoretical biophysics in which stochastic methods are important. In the last years the study of membrane noise has become an important method in biophysics. Valuable information on the ion transport mechanisms in membranes can be obtained from noise analysis. A number of different processes such as the opening and closing of ion channels have been shown to be sources of the measured current or voltage fluctuations. Bio­ logical 'transport systems can be complex. For example, the tr...

  18. Multichannel simultaneous magnetic induction measurement system (MUSIMITOS)

    International Nuclear Information System (INIS)

    Steffen, Matthias; Leonhardt, Steffen; Heimann, Konrad; Bernstein, Nina

    2008-01-01

    Non-contact heart and lung activity monitoring would be a desirable supplement to conventional monitoring techniques. Based on the potential of non-contact magnetic induction measurements, requirements for an adequate monitoring system were estimated. This formed the basis for the development of the presented extendable multichannel simultaneous magnetic induction measurement system (MUSIMITOS). Special focus was given to the dynamic behaviour and simultaneous multichannel measurements, so that the system allows for up to 14 receiver coils working simultaneously at 6 excitation frequencies. Moreover, a real-time software concept for online signal processing visualization in combination with a fast software demodulation is presented. Finally, first steps towards a clinical application are pointed out and technical performance as well as first in vivo measurements are presented. This paper covers some aspects previously presented in Steffen and Leonhardt (2007 Proc. 13th Int. Conf. on Electrical Bioimpedance and the 8th Conf. on Electrical Impedance Tomography, Graz 2007)

  19. Dust Transport And Force Equilibria In Magnetized Dusty DC Discharges

    International Nuclear Information System (INIS)

    Land, Victor; Thomas, Edward Jr.; Williams, Jeremaiah

    2005-01-01

    We have performed experiments on magnetized dusty Argon DC discharges. Here we report on the characterization of the plasma- and the dustparameters and on the response of the dust particles and the plasma to a change in the magnetic configuration inside the discharge. Finally, we show a case in which the balance of forces acting on the dust particles differs from the classical balance (in which the electrostatic force balances the downward force of gravity). In this case the electrostatic force acts as a downward force on the dust particles. From observations we will argue that the ion drag force might be the force that balances this downward electrostatic force

  20. Road Transportable Analytical Laboratory (RTAL) system

    International Nuclear Information System (INIS)

    1993-01-01

    The goal of this contractual effort is the development and demonstration of a Road Transportable Analytical Laboratory (RTAL) system to meet the unique needs of the Department of Energy (DOE) for rapid, accurate analysis of a wide variety of hazardous and radioactive contaminants in soil, groundwater, and surface waters. This laboratory system will be designed to provide the field and laboratory analytical equipment necessary to detect and quantify radionuclides, organics, heavy metals and other inorganics, and explosive materials. The planned laboratory system will consist of a set of individual laboratory modules deployable independently or as an interconnected group to meet each DOE site's specific needs

  1. Effects from magnetic boundary conditions in superconducting-magnetic proximity systems

    Directory of Open Access Journals (Sweden)

    Thomas E. Baker

    2016-05-01

    Full Text Available A superconductor-magnetic proximity system displays singlet-triplet pair correlations in the magnetization as a function of inhomogeneities of the magnetic profile. We discuss how the magnetic boundary conditions affects differently the curvature and winding number of rotating magnetizations in the three commonly used structures to generate long range triplet components: an exchange spring, a helical structure and a misaligned magnetic multilayer. We conclude that the choice of the system is dictated by the goal one wishes to achieve in designing a spintronic device but note that only the exchange spring presently offers an experimentally realizable magnetic profile that is tunable.

  2. Adaptive fuzzy-neural-network control for maglev transportation system.

    Science.gov (United States)

    Wai, Rong-Jong; Lee, Jeng-Dao

    2008-01-01

    A magnetic-levitation (maglev) transportation system including levitation and propulsion control is a subject of considerable scientific interest because of highly nonlinear and unstable behaviors. In this paper, the dynamic model of a maglev transportation system including levitated electromagnets and a propulsive linear induction motor (LIM) based on the concepts of mechanical geometry and motion dynamics is developed first. Then, a model-based sliding-mode control (SMC) strategy is introduced. In order to alleviate chattering phenomena caused by the inappropriate selection of uncertainty bound, a simple bound estimation algorithm is embedded in the SMC strategy to form an adaptive sliding-mode control (ASMC) scheme. However, this estimation algorithm is always a positive value so that tracking errors introduced by any uncertainty will cause the estimated bound increase even to infinity with time. Therefore, it further designs an adaptive fuzzy-neural-network control (AFNNC) scheme by imitating the SMC strategy for the maglev transportation system. In the model-free AFNNC, online learning algorithms are designed to cope with the problem of chattering phenomena caused by the sign action in SMC design, and to ensure the stability of the controlled system without the requirement of auxiliary compensated controllers despite the existence of uncertainties. The outputs of the AFNNC scheme can be directly supplied to the electromagnets and LIM without complicated control transformations for relaxing strict constrains in conventional model-based control methodologies. The effectiveness of the proposed control schemes for the maglev transportation system is verified by numerical simulations, and the superiority of the AFNNC scheme is indicated in comparison with the SMC and ASMC strategies.

  3. Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field

    International Nuclear Information System (INIS)

    Wang, C.; Wang, F.; Cao, J. C.

    2014-01-01

    Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation

  4. Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field.

    Science.gov (United States)

    Wang, C; Wang, F; Cao, J C

    2014-09-01

    Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation.

  5. Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C., E-mail: cwang@mail.sim.ac.cn; Wang, F.; Cao, J. C., E-mail: jccao@mail.sim.ac.cn [Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050 (China)

    2014-09-01

    Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation.

  6. Design considerations for ITER magnet systems

    International Nuclear Information System (INIS)

    Henning, C.D.; Miller, J.R.

    1989-01-01

    The International Thermonuclear Experimental Reactor (ITER) is now completing a definition phase as a beginning of a three-year design effort. Preliminary parameters for the superconducting magnet system have been established to guide further and more detailed design work. Radiation tolerance of the superconductors and insulators has been of prime importance, since it sets requirements for the neutron-shield dimension and sensitively influences reactor size. The major levels of mechanical stress in the structure appear in the cases of the inboard legs of the toroidal-field (TF) coils. The cases of the poloidal-field (PF) coils must be made thin or segmented to minimize eddy current heating during inductive plasma operation. As a result, the winding packs of both the TF and PF coils includes significant fractions of steel. The authors present here preliminary ITER magnet systems design parameters taken from trade studies, design, and analyses performed by the Home Teams of the four ITER participants, by the ITER Magnet Design Unit in Garching, and by other participants at workshops organized by the Magnet Design Unit

  7. Arterial intelligent transportation systems : infrastructure elements and traveler information requirements.

    Science.gov (United States)

    2009-08-01

    Applying Intelligent Transportation Systems (ITS) to arterial systems allows TxDOT to significantly enhance : transportation system operation efficiency and improve traffic mobility. However, no guidelines are available to : assist TxDOT staff in sel...

  8. Effects of magnetic barriers on transport and magnetoresistance in a two-dimensional electronic device

    Energy Technology Data Exchange (ETDEWEB)

    He, H. L.; Zhang, X. W., E-mail: hedge80@sina.com.cn; Dai, B.; Ren, Y. [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Wang, Z. P. [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900 (China)

    2016-05-15

    We study theoretically the giant magnetoresistance (GMR) effect of 2-dimensional electron system (2DES) by the transfer matrix method. To produce the inhomogeneous magnetic field, two magnetic strips are pre-deposited on the surface of 2DES. In our work, we fix the magnetization M in one magnetic strip and adjust the tilting angle θ of magnetization in the other. The result shows that the electronic transmission and conductance vary significantly for different θ. The minimum conductance can be obtained at θ = π which corresponds to the magnetization anti-parallel alignment. The magnetoresistance ratio (MRR) calculation also indicates we would get the maximum in that case. Furthermore, we consider the magnetization M dependence of MRR in this work. When M increases, MRR peaks get higher and broader and more numbers of peaks can be observed. These results offer an alternative to get a tunable GMR device which can be controlled by adjusting the magnetization M and the magnetized angle θ.

  9. Trial Application of Pulse-Field Magnetization to Magnetically Levitated Conveyor System

    Directory of Open Access Journals (Sweden)

    Yoshihito Miyatake

    2012-01-01

    Full Text Available Magnetically levitated conveyor system using superconductors is discussed. The system is composed of a levitated conveyor, magnetic rails, a linear induction motor, and some power supplies. In the paper, pulse-field magnetization is applied to the system. Then, the levitation height and the dynamics of the conveyor are controlled. The static and dynamic characteristics of the levitated conveyor are discussed.

  10. Repeating pulsed magnet system for axion-like particle searches and vacuum birefringence experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, T., E-mail: yamazaki@icepp.s.u-tokyo.ac.jp [International Center for Elementary Particle Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Inada, T.; Namba, T. [International Center for Elementary Particle Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Asai, S. [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kobayashi, T. [International Center for Elementary Particle Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Matsuo, A.; Kindo, K. [The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8581 (Japan); Nojiri, H. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2016-10-11

    We have developed a repeating pulsed magnet system which generates magnetic fields of about 10 T in a direction transverse to an incident beam over a length of 0.8 m with a repetition rate of 0.2 Hz. Its repetition rate is by two orders of magnitude higher than usual pulsed magnets. It is composed of four low resistance racetrack coils and a 30 kJ transportable capacitor bank as a power supply. The system aims at axion-like particle searches with a pulsed light source and vacuum birefringence measurements. We report on the details of the system and its performances.

  11. Low energy beam transport system developments

    Energy Technology Data Exchange (ETDEWEB)

    Dudnikov, V., E-mail: vadim@muonsinc.com [Muons, Inc., Batavia, IL 60510 (United States); Han, B.; Stockli, M.; Welton, R. [ORNL, Oak Ridge, TN 37831 (United States); Dudnikova, G. [University of Maryland, College Park, MD 3261 (United States); Institute of Computational Technologies SBRAS, Novosibirsk (Russian Federation)

    2015-04-08

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H{sup −} beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H{sup −} beams, but such gas densities cause unacceptably high H{sup −} beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H{sup −} beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  12. Magnetic and transport properties of Sm7Rh3 single crystal

    International Nuclear Information System (INIS)

    Tsutaoka, Takanori; Noguchi, Daisuke; Nakamori, Yuko; Nakamoto, Go; Kurisu, Makio

    2013-01-01

    A Sm 7 Rh 3 single crystal with Th 7 Fe 3 -type hexagonal structure was grown by the Czochralski method. The magnetic and transport measurements revealed a uniaxial magnetocrystalline anisotropy in the magnetic susceptibility, magnetization and electrical resistivity. Sm 7 Rh 3 was found to exhibit antiferromagnetic transition at T N =54.0 K and another magnetic transition at T t =25.0 K. The specific heat data clearly showed the bulk nature of paramagnetic to ordered magnetic phase transition by the presence of a sharp peak at T N and a small anomaly at T t . The paramagnetic susceptibility does not obey the Curie–Weiss law, attributing to the temperature independent Van Vleck contribution and Pauli paramagnetism of conduction electrons. Metamagnetic phase transitions were observed along the c-axis in the ordered states. The magnetic field H–temperature T phase diagram was constructed. Anisotropic paramagnetic electrical resistivity showed the small negative temperature coefficients

  13. Probing exotic magnetic phases and electrical transport in Cr-rich γ-NiFeCr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Pampa [S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098 (India); Majumdar, A.K., E-mail: akm@bose.res.in [S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098 (India); Ramakrishna Mission Vivekananda University, PO Belur Math, Howrah 711202 (India); Nigam, A.K. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

    2015-05-01

    We have identified ferromagnetic, antiferromagnetic, and re-entrant spin-glass-like phases in Cr-rich γ-NiFeCr alloys and studied their critical magnetic behavior. Their electrical resistivity exhibits distinct minima between 10 and 24 K with ρ∞−√T due to electron–electron interaction effects. Electron–phonon and electron–magnon contributions to ρ are isolated. The magnetoresistance shows hysteresis effects, a signature of spin-glass-like phases and a sign reversal with change of magnetic states. We have also observed that the nature of magnetic states strongly depends on the concentration of Fe and Cr. In this system, even a small amount of Fe enhances ferromagnetism a lot while addition of a little bit of Cr suppresses ferromagnetism and takes the system to the antiferromagnetic regime. The correlation between the magnetic and the electrical properties are more meaningful here since both studies were done on the same set of samples which have rather high melting points. - Highlights: • Identified ferro, antiferro, and re-entrant spin-glass phases in Ni–Fe–Cr alloys. • Resistivity ρ~−√T shows minima from 10–24 K due to electron–electron interaction. • Electron–phonon and electron–magnon contributions to ρ are isolated. • Magneto-transport measurements strengthened the magnetic phases identified. • Correlation in magnetic/electrical properties more meaningful if same samples used.

  14. Fuels processing for transportation fuel cell systems

    Science.gov (United States)

    Kumar, R.; Ahmed, S.

    Fuel cells primarily use hydrogen as the fuel. This hydrogen must be produced from other fuels such as natural gas or methanol. The fuel processor requirements are affected by the fuel to be converted, the type of fuel cell to be supplied, and the fuel cell application. The conventional fuel processing technology has been reexamined to determine how it must be adapted for use in demanding applications such as transportation. The two major fuel conversion processes are steam reforming and partial oxidation reforming. The former is established practice for stationary applications; the latter offers certain advantages for mobile systems and is presently in various stages of development. This paper discusses these fuel processing technologies and the more recent developments for fuel cell systems used in transportation. The need for new materials in fuels processing, particularly in the area of reforming catalysis and hydrogen purification, is discussed.

  15. Multi-level, automatic file management system using magnetic disk, mass storage system and magnetic tape

    International Nuclear Information System (INIS)

    Fujii, Minoru; Asai, Kiyoshi

    1979-12-01

    A simple, effective file management system using magnetic disk, mass storage system (MSS) and magnetic tape is described. Following are the concepts and techniques introduced in this file management system. (1) File distribution and continuity character of file references are closely approximated by memory retention function. A density function using the memory retention function is thus defined. (2) A method of computing the cost/benefit lines for magnetic disk, MSS and magnetic tape is presented. (3) A decision process of an optimal organization of file facilities incorporating file demands distribution to respective file devices, is presented. (4) A method of simple, practical, effective, automatic file management, incorporating multi-level file management, space management and file migration control, is proposed. (author)

  16. Properties of the transfer matrices of deflecting magnet systems for free electron laser

    International Nuclear Information System (INIS)

    Takao, Masaru

    1993-01-01

    The oscillation of the free electron laser (FEL) requires the high current and low emittance electron beam. The beam transport system should be achromatic and isochronous to preserve the brightness and the emittance of the electron beam. In this paper we clarify the algebraic properties of the transfer matrices of the magnetic deflection system, which is a key component in the beam transport line. (author)

  17. The Efficiency of the Bimodal System Transportation

    Directory of Open Access Journals (Sweden)

    Nada Štrumberger

    2012-10-01

    Full Text Available The development of fast railway results in an increased applicationof Trailer Train bimodal system transportation. Thetraffic costs are multiply reduced, particularly the variablecosts. On the other hand the environmental pollution from exhaustgases is also reduced. Therefore, by the year 2010 cargotransport should be preponderant~v used which would be characterisedby fast electric trains producing less noise, at lowercosts and with clean environment.

  18. Cotton Transportation and Logistics: A Dynamic System

    OpenAIRE

    Robinson, John R.; Park, John L.; Fuller, Stephen

    2007-01-01

    The paper reviews the evolution of U.S. cotton transportation and logistics patterns over the last three decades. There have been many forces of change over this time period, with the largest change being a shift from primarily domestic market destinations to the international market. We describe the pre-1999 system and flow patterns when domestic consumption of U.S. cotton was dominant. We contrast this with current flow patterns as measured by available secondary export data and a sample of...

  19. Assateague Island National Seashore alternative transportation systems planning study and business plan for alternative transportation

    Science.gov (United States)

    2012-08-31

    The purpose of this study was to (1) study the potential expansion of existing alternative transportation systems (bicycle facilities) and development of new alternative transportation systems in and around the Maryland District of Assateague Island ...

  20. Nonlocality of plasma fluctuations and transport in magnetically confined plasmas nonlocal plasma transport and radial structural formation

    International Nuclear Information System (INIS)

    Toi, Kazuo

    2002-01-01

    Experimental evidence and underlying physical processes of nonlocal characters and structural formation in magnetically confined toroidal plasmas are reviewed. Radial profiles of the plasmas exhibit characteristic structures, depending on the various confinement regimes. Profile stiffness subjected to some global constraint and rapid plasma responses to applied plasma perturbation result from nonlocal transport. Once the plasma is free from the constraint, the plasma state can be changed to a new state exhibiting various types of prominent structural formation such as an internal transport barrier. (author)

  1. Evaluation of alternative public transportation systems in Izmit urban transportation via axiomatic design method

    Directory of Open Access Journals (Sweden)

    Gülşen AKMAN

    2016-02-01

    Full Text Available In the world and in our country, most of urban transportation is performed by public transportation. Public transportation is a system which provides transportation easiness and opportunity to people, not to vehicles. Therefore, giving priority to public transportation system is necessary in organizing urban transportation. In this study, in order to reduce traffic intensity and to facilitate passenger transportation in Izmit urban transportation, It is tried to determine appropriate public transportation system. For this, firstly, alternatives which could be used for public transportation were determined. These alternatives are metro, metrobus, tram, light rail system and monorail. Afterwards, the variables affecting decision making about public transportation were determined. These variables are cost, transportation line features, vehicle characteristics, sensitivity to environment and customer satisfaction. Lastly, most appropriate public transportation system is proposed by using the axiomatic design method. As a result, light trail system and metrobus are determined as the most appropriate alternatives for Izmit public transportation system.Keywords: Urban transportation, Multi criteria decision making, Axiomatic design

  2. The Palm Desert renewable [hydrogen] transportation system

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlin, C.E.; Lehman, P. [Humboldt State Univ., Arcata, CA (United States). Schatz Energy Research Center

    1998-08-01

    This paper describes the Schatz Energy Research Center (SERC) progress on the Palm Desert Renewable Hydrogen Transportation System Project for the period June 1997 through May 1998. The project began in March 1996. The goal of the Palm Desert Project is to develop a clean and sustainable transportation system for a community. The project demonstrates the practical utility of hydrogen as a transportation fuel and the proton exchange membrane (PEM) fuel cell as a vehicle power system. The project includes designing and building 4 fuel cell powered vehicles, a solar hydrogen generating and refueling station, and a fuel cell vehicle diagnostic center. Over this last year, SERC has built a fuel cell powered neighborhood electric vehicle and delivered it to the City of Palm Desert. The design of the hydrogen refueling station is near completion and it is anticipated that construction will be complete in the fall of 1998. The vehicles are currently being refueled at a temporary refueling station. The diagnostic center is being designed and maintenance procedures as well as computer diagnostic programs for the fuel cell vehicles are being developed. City employees are driving the vehicles daily and monitoring data are being collected. The drivers are pleased with the performance of the vehicles.

  3. Pipesworld : applying planning systems to pipeline transportation

    Energy Technology Data Exchange (ETDEWEB)

    Milidiu, R.L.; Santos Liporace, F. [Pontificia Univ. Catolica, Rio de Janeiro (Brazil). Dept. de Informatica

    2004-07-01

    This paper explored issues facing the complex task of managing pipelines that transport large volumes of petroleum products over long distances. Since oil pipelines are generally a few inches wide and several miles long, reasonable amounts of distinct products can be transported with very small loss due to the mixing at liquid boundaries. Optimizing the transportation through oil pipelines in terms of maintenance and environmental safety is a high priority for pipeline operators. This paper presented the Pipesworld model which takes into account features such as product interface constraints, limited product storage capacities and due dates for product delivery. It has been benchmarked as a start-of-art general purpose artificial planning system. This paper also reported the results derived by general purpose artificial intelligence planning systems when applied to the Pipesworld model. It demonstrated how various modelling techniques can be used to enhance the planners performance. Current work in developing Plumber was also presented. This dedicated solver that addresses operational situations uses both general purpose planning techniques as well as domain specific knowledge. When Plumber was incorporated into Pipesworld, its outperformed Fast-Forward, one of the best available general purpose planning systems, suggesting that improved versions of Plumber have the potential to deal with various problem scenarios in pipeline operations. 11 refs., 2 tabs., 3 figs.

  4. 电场、磁场对二维无序系统电子输运的影响%Influence of Electric Field and Magnetic Field on Transport Properties of Two-dimensional Disordered Electron System

    Institute of Scientific and Technical Information of China (English)

    刘龙; 孙素涛; 白志明

    2017-01-01

    研究了电场、磁场作用下,二维无序杂质系统电导的物理性质.电场的作用削弱了系统电导的“台阶”量子效应,随着中间散射区域尺寸的增大,系统电导随电子能量的变化振荡加剧;系统电导随着磁场的变化表现出周期性振荡行为,其振荡的剧烈程度随外部电压的增大而变小;受杂质散射的影响,系统电导随无序杂质质量分数的增大而减小.%On the action of electric field and magnetic field,the phenomenon of quantized conductance in a two-dimensional system with disordered impurities is investigated.The electric field decreases the conductance and reduced its"step"quantum effect.The increase of the size of the intermediate scattering area intensifies the oscillation of the conductance varying with the electron energy.The conductance exhibits periodic oscillation with the external magnetic field,and the intensity of the oscillation becomes smaller with the increase of the electric field.With the increase of the impurity concentration,the conductance decreases.

  5. The Place of Railway Transport in Romania’s Transport System

    OpenAIRE

    Dãneci-Pãtrãu Daniel; Coca Carmen Elena

    2012-01-01

    The transport activity in all its forms represents one of the most complex sections of an economy, but also an important factor of influence over the quality of life, that is why current preoccupations of international organisms are oriented towards measures meant to develop performing transport systems and compatible with the environment. In the article the main activities and resources of Romania’s railway transport system are presented , the place of the railway transport in the transport ...

  6. Visualizing Mobility of Public Transportation System.

    Science.gov (United States)

    Zeng, Wei; Fu, Chi-Wing; Arisona, Stefan Müller; Erath, Alexander; Qu, Huamin

    2014-12-01

    Public transportation systems (PTSs) play an important role in modern cities, providing shared/massive transportation services that are essential for the general public. However, due to their increasing complexity, designing effective methods to visualize and explore PTS is highly challenging. Most existing techniques employ network visualization methods and focus on showing the network topology across stops while ignoring various mobility-related factors such as riding time, transfer time, waiting time, and round-the-clock patterns. This work aims to visualize and explore passenger mobility in a PTS with a family of analytical tasks based on inputs from transportation researchers. After exploring different design alternatives, we come up with an integrated solution with three visualization modules: isochrone map view for geographical information, isotime flow map view for effective temporal information comparison and manipulation, and OD-pair journey view for detailed visual analysis of mobility factors along routes between specific origin-destination pairs. The isotime flow map linearizes a flow map into a parallel isoline representation, maximizing the visualization of mobility information along the horizontal time axis while presenting clear and smooth pathways from origin to destinations. Moreover, we devise several interactive visual query methods for users to easily explore the dynamics of PTS mobility over space and time. Lastly, we also construct a PTS mobility model from millions of real passenger trajectories, and evaluate our visualization techniques with assorted case studies with the transportation researchers.

  7. Magnetic System for the CLAS12 Proposal

    International Nuclear Information System (INIS)

    Statera, Marco; Contalbrigo, Marco M.; Pappalardo, Luciano Libero; Barion, Luca; Bertelli, S.; Ciullo, Giuseppe; Lenisa, Paolo

    2013-01-01

    The conceptual design of a magnetic system for an experiment to measure the transverse spin effects in semi-inclusive Deep Inelastic Scattering (SIDIS) at 11 GeV with a transversely polarized target using the CLAS12 detector at Jefferson Lab is presented. A proposal has been submitted to study spin azimuthal asymmetries in SIDIS using an 11-GeV polarized electron beam from the upgraded CEBAF facility and the CLAS12 detector equipped with a transversely polarized target. The main focus of the experiment will be the measurement of transverse target single and double spin asymmetries in the reaction ep↑ -> ehX, where e is an electron, p↑ is transversely polarized proton, h is a meson (e.g., a pion or a kaon) and X is the undetected final state. The details of the conceptual design of the shielding magnetic system and transverse dipole are reported

  8. DIRECT OBSERVATION OF THE TURBULENT emf AND TRANSPORT OF MAGNETIC FIELD IN A LIQUID SODIUM EXPERIMENT

    Energy Technology Data Exchange (ETDEWEB)

    Rahbarnia, Kian; Brown, Benjamin P.; Clark, Mike M.; Kaplan, Elliot J.; Nornberg, Mark D.; Rasmus, Alex M.; Taylor, Nicholas Zane; Forest, Cary B. [Department of Physics, University of Wisconsin-Madison, 1150 University Ave, Madison, WI 53706 (United States); Jenko, Frank; Limone, Angelo [Max-Planck-Institut fuer Plasmaphysik (IPP), EURATOM Association, D-85748 Garching (Germany); Pinton, Jean-Francois; Plihon, Nicolas; Verhille, Gautier, E-mail: kian.rahbarnia@ipp.mpg.de [Laboratoire de Physique de l' Ecole Normale Superieure de Lyon, CNRS and Universite de Lyon, F-69364 Lyon (France)

    2012-11-10

    For the first time, we have directly measured the transport of a vector magnetic field by isotropic turbulence in a high Reynolds number liquid metal flow. In analogy with direct measurements of the turbulent Reynolds stress (turbulent viscosity) that governs momentum transport, we have measured the turbulent electromotive force (emf) by simultaneously measuring three components of velocity and magnetic fields, and computed the correlations that lead to mean-field current generation. Furthermore, we show that this turbulent emf tends to oppose and cancel out the local current, acting to increase the effective resistivity of the medium, i.e., it acts as an enhanced magnetic diffusivity. This has important implications for turbulent transport in astrophysical objects, particularly in dynamos and accretion disks.

  9. DIRECT OBSERVATION OF THE TURBULENT emf AND TRANSPORT OF MAGNETIC FIELD IN A LIQUID SODIUM EXPERIMENT

    International Nuclear Information System (INIS)

    Rahbarnia, Kian; Brown, Benjamin P.; Clark, Mike M.; Kaplan, Elliot J.; Nornberg, Mark D.; Rasmus, Alex M.; Taylor, Nicholas Zane; Forest, Cary B.; Jenko, Frank; Limone, Angelo; Pinton, Jean-François; Plihon, Nicolas; Verhille, Gautier

    2012-01-01

    For the first time, we have directly measured the transport of a vector magnetic field by isotropic turbulence in a high Reynolds number liquid metal flow. In analogy with direct measurements of the turbulent Reynolds stress (turbulent viscosity) that governs momentum transport, we have measured the turbulent electromotive force (emf) by simultaneously measuring three components of velocity and magnetic fields, and computed the correlations that lead to mean-field current generation. Furthermore, we show that this turbulent emf tends to oppose and cancel out the local current, acting to increase the effective resistivity of the medium, i.e., it acts as an enhanced magnetic diffusivity. This has important implications for turbulent transport in astrophysical objects, particularly in dynamos and accretion disks.

  10. Applications concepts of small regenerative cryocoolers in superconducitng magnet systems

    NARCIS (Netherlands)

    van der Laan, M.T.G.; van der Laan, M.T.G.; Tax, R.B.; ten Kate, Herman H.J.

    1992-01-01

    Superconducting magnets are in growing use outside laboratories for example MRI scanners in hospitals. Other applications under development are magnet systems for separation, levitated trains and ship propulsion. The application of cryocoolers can make these systems more practical. Interfacing these

  11. Magnetic field devices for neutron spin transport and manipulation in precise neutron spin rotation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado-Velázquez, M. [Posgrado en Ciencias Físicas, Universidad Nacional Autónoma de México, 04510 (Mexico); Barrón-Palos, L., E-mail: libertad@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 (Mexico); Crawford, C. [University of Kentucky, Lexington, KY 40506 (United States); Snow, W.M. [Indiana University, Bloomington, IN 47405 (United States)

    2017-05-11

    The neutron spin is a critical degree of freedom for many precision measurements using low-energy neutrons. Fundamental symmetries and interactions can be studied using polarized neutrons. Parity-violation (PV) in the hadronic weak interaction and the search for exotic forces that depend on the relative spin and velocity, are two questions of fundamental physics that can be studied via the neutron spin rotations that arise from the interaction of polarized cold neutrons and unpolarized matter. The Neutron Spin Rotation (NSR) collaboration developed a neutron polarimeter, capable of determining neutron spin rotations of the order of 10{sup −7} rad per meter of traversed material. This paper describes two key components of the NSR apparatus, responsible for the transport and manipulation of the spin of the neutrons before and after the target region, which is surrounded by magnetic shielding and where residual magnetic fields need to be below 100 μG. These magnetic field devices, called input and output coils, provide the magnetic field for adiabatic transport of the neutron spin in the regions outside the magnetic shielding while producing a sharp nonadiabatic transition of the neutron spin when entering/exiting the low-magnetic-field region. In addition, the coils are self contained, forcing the return magnetic flux into a compact region of space to minimize fringe fields outside. The design of the input and output coils is based on the magnetic scalar potential method.

  12. Arrangement of magnets for magnetic support or guide system. Magnetanordnung fuer ein magnetisches Trag- oder Fuehrungssystem

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, G; Schwaerzler, P

    1978-01-26

    The invention refers to an arrangement of magnets for a magnetic support or guide system, particularly for a levitation vehicle. A magnetic tape which can be moved without touching along a fixed armature rail is provided, having an additional magnet at its ends. The pole surfaces of each additional magnet increase their spacing from the armature rail with increasing distance from the end of the magnetic tape concerned. The purpose of the invention is to improve such an arrangement of magnets so that the extra expense of additional magnets is avoided. According to the invention, this is achieved by the pole surfaces of the outer electromagnets of the magnetic tape, instead of the additional magnets, having an increased spacing from the armature rail with increasing approach to the end of the core free of connected electromagnets. The part of the pole faces remote from the armature rail is made curved in order to produce great leakage of the magnetic field.

  13. Design and fabrication of the MFTF-B magnet system

    International Nuclear Information System (INIS)

    Tatro, R.E.; Kozman, T.A.

    1985-09-01

    The MFTF-B superconducting magnet system consists of 40 NbTi magnets and two Nb 3 Sn magnets. General Dynamics (GD) designed all magnets except for the small trim coils. GD then fabricated 20 NbTi magnets, while LLNL fabricated 20 NbTi magnets and two Nb 3 Sn magnets. The design phase was completed in February 1984 and included the competitive procurement of magnet structural fabrication, superconductor, G-10CR insulation, support struts and bearings, vapor-cooled leads, and thermal shields for all magnets. Fabrication of all magnets was completed in March 1985. At GD, dual assembly lines were necessary during fabrication in order to meet the aggressive LLNL schedule. The entire magnet system has been installed and aligned at LLNL, and Tech Demo tests will be performed during September-November 1985

  14. Overview of magnetic structure induced by the TEXTOR-DED and the related transport

    International Nuclear Information System (INIS)

    Abdullaev, S.S.; Finken, K.H.; Kobayashi, M.; Reiser, D.; Reiter, D.; Jakubowski, M.W.; Runov, A.M.

    2003-01-01

    The Dynamic Ergodic Divertor (DED), a new concept of the ergodic divertor, is presently installed for the TEXTOR tokamak. Beside the conventional ergodic divertor operation the DED also permits the operation with a rotating magnetic field which allows, in particular, to broaden the heat deposition pattern on the divertor plates. Since its first proposal of the DED in 1996 the structure of magnetic field, especially, the onset of ergodic zone of field lines and related transport in the DED operation has been extensively studied using different theoretical and numerical methods. New methods to study the magnetic field, in particular, the field line mapping have been developed. The presentation gives the overview of the studies on the structure of magnetic field in the DED, the formation of the ergodic and laminar zones of field lines at the plasma edge. It also includes studies on the modelling efforts of the transport of heat and particles in the ergodic and laminar zones. (author)

  15. Microstructural effects on the magnetic and magneto-transport properties of electrodeposited Ni nanowire arrays

    International Nuclear Information System (INIS)

    Chen, Shu-Fang; Wei, Hao Han; Liu, Chuan-Pu; Hsu, C Y; Huang, J C A

    2010-01-01

    The magnetic and magneto-transport properties of Ni nanowire (NW) arrays, fabricated by electrodeposition in anodic-aluminum-oxide (AAO) templates, have been investigated. The AAO pores have diameters ranging from 35 to 75 nm, and the crystallinity of the Ni NW arrays could change from poly-crystalline to single-crystalline with the [111] and [110] orientations based on the electrodeposition potential. Notably, double switching magnetization loops and double-peaked magnetoresistance curves were observed in [110]-oriented NWs. The crystalline orientation of the Ni NW arrays is found to influence the corresponding magnetic and magneto-transport properties significantly. These magnetic behaviors are dominated by the competition between the magneto-crystalline and shape anisotropy.

  16. Turbulence and transport in a magnetized argon plasma

    International Nuclear Information System (INIS)

    Pots, B.F.M.

    1979-01-01

    An experimental study on turbulence and transport in the highly ionized argon plasma of a hollow cathode discharge is described. In order to determine the plasma parameters three standard diagnostics have been used, whilst two diagnostics have been developed to study the plasma turbulence. (Auth.)

  17. A review of dynamic characteristics of magnetically levitated vehicle systems

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Y.; Chen, S.S.

    1995-11-01

    The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, while vehicle stability is an important safety-related element. To design a guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore, the trade-off between guideway smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which reviews various aspects of the dynamic characteristics, experiments and analysis, and design guidelines for maglev systems, discusses vehicle stability, motion dependent magnetic force components, guideway characteristics, vehicle/ guideway interaction, ride quality, suspension control laws, aerodynamic loads and other excitations, and research needs.

  18. Superconducting magnet system for the J-PARC neutrino beam line. Development, construction and operation of superconducting magnets

    International Nuclear Information System (INIS)

    Sasaki, Ken-ichi; Nakamoto, Tatsushi; Ajima, Yasuo; Okamura, Takahiro; Ogitsu, Toru; Kimura, Nobuhiro; Terashima, Akio; Tomaru, Takayuki; Higashi, Norio

    2010-01-01

    Superconducting combined-function magnets have been utilized for the 50-GeV, 750-kW proton beam line in the J-PARC neutrino experiment. The magnets are designed to provide a dipole field of 2.6 T combined with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm at a nominal current of 7,345 A. Following the success of a prototype R and D project, a superconducting magnet system for the J-PARC neutrino beam line has been constructed since 2005. Using a new conceptual beam line with the superconducting combined-function magnets has demonstrated successful beam transport to the target neutrino production. (author)

  19. Turbulent transport of impurities in a magnetized plasma; Transport turbulent d'impuretes dans un plasma magnetise

    Energy Technology Data Exchange (ETDEWEB)

    Dubuit, N

    2006-10-15

    This work deals with the transport of impurities in magnetically confined thermonuclear plasmas. The accumulation of impurities in the core of the plasma would imply dramatic losses of energy that may lead to the extinction of the plasma. On the opposite, the injection of impurities in the plasma edge is considered as an efficient means to extract heat without damaging the first wall. The balance between these 2 contradictory constraints requires an accurate knowledge of the impurity transport inside the plasma. The effect of turbulence, the main transport mechanism for impurities is therefore a major issue. In this work, the complete formula of a turbulent flow of impurities for a given fluctuation spectrum has been inferred. The origin and features of the main accumulation processes have been identified. The main effect comes from the compressibility of the electrical shift speed in a plane perpendicular to the magnetic field. This compressibility appears to be linked to the curvature of the magnetic field. A less important effect is a thermal-diffusion process that is inversely proportional to the number of charges and then disappears for most type of impurities except the lightest. This effect implies an impurity flux proportional to the temperature gradient and its direction can change according to the average speed of fluctuations. A new version of the turbulence code TRB has been developed. This new version allows the constraints of the turbulence not by the gradients but by the flux which is more realistic. The importance of the processes described above has been confirmed by a comparison between calculation and experimental data from Tore-supra and the Jet tokamak. The prevailing role of the curvature of the magnetic field in the transport impurity is highlighted. (A.C.)

  20. Development of cask and transportation system

    International Nuclear Information System (INIS)

    Ro, Seong Gy; Kang, Hee Dong; Lee, Heung Young; Seo, Ki Suk; Koo, Jung Hoe; Jung, Sung Hwan; Yoon, Jung Hyun; Lee, Ju Chan; Bang, Kyung Sik; Baek, Chang Yeol

    1992-03-01

    The major goal of this project is to establish the safe transport system and obtain the necessary data for cask development by during research work for the design and safety test of shipping cask. The analysis technique using computer code for design has been studied in the field of structure, thermal and shielding analysis in this study. And also the test and measurement technology was developed for the measuring system of drop and fire test. It is expected that research activity ensured in this job will enable us to ultilize the basic data for the cask development. (Author)

  1. High pressure apparatus transport properties study in high magnetic field

    Czech Academy of Sciences Publication Activity Database

    Honda, F.; Sechovský, V.; Mikulina, O.; Kamarád, Jiří; Alsmadi, A. M.; Nakotte, H.; Lacerda, A. H.

    2002-01-01

    Roč. 16, 20, 21 & 22 (2002), s. 3330-3333 ISSN 0217-9792 R&D Projects: GA ČR GP202/01/D045; GA ČR GA202/00/1217; GA MŠk ME 165 Grant - others:NSF(XX) DMR-0094241 Institutional research plan: CEZ:AV0Z1010914 Keywords : high-pressure apparatus Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.604, year: 2002

  2. Electrical and magnetic transport properties of DyTiGe

    International Nuclear Information System (INIS)

    Dagula, W.; Tegus, O.; Li, X.W.; Zhang, L.; Brueck, E.; Boer, F.R. de; Buschow, K.H.J.

    2004-01-01

    Electrical resistivity and magnetoresistance of DyTiGe were investigated as a function of temperature and magnetic field. DyTiGe is an antiferromagnet with Neel temperature, T N , of 180 K. The electrical resistivity has an anomaly around T N . Below T N , the magnetoresistance of DyTiGe abruptly changes at a critical field. At 5 K, we observe a magnetoresistance reduction of about 20%

  3. Failure Analysis of Storage Data Magnetic Systems

    Directory of Open Access Journals (Sweden)

    Ortiz–Prado A.

    2010-10-01

    Full Text Available This paper shows the conclusions about the corrosion mechanics in storage data magnetic systems (hard disk. It was done from the inspection of 198 units that were in service in nine different climatic regions characteristic for Mexico. The results allow to define trends about the failure forms and the factors that affect them. In turn, this study has analyzed the causes that led to mechanical failure and those due to deterioration by atmospheric corrosion. On the basis of the results obtained from the field sampling, demonstrates that the hard disk failure is fundamentally by mechanical effects. The deterioration by environmental effects were found in read-write heads, integrated circuits, printed circuit boards and in some of the electronic components of the controller card of the device, but not in magnetic storage surfaces. There fore, you can discard corrosion on the surface of the disk as the main kind of failure due to environmental deterioration. To avoid any inconvenience in the magnetic data storage system it is necessary to ensure sealing of the system.

  4. Magnetic field measuring system for remapping the ORIC magnetic field

    International Nuclear Information System (INIS)

    Mosko, S.W.; Hudson, E.D.; Lord, R.S.; Hensley, D.C.; Biggerstaff, J.A.

    1977-01-01

    The Holifield Heavy Ion Research Facility will integrate a new 25 MV tandem electrostatic acccelerator into the existing cyclotron laboratory which includes the Oak Ridge Isochronous Cyclotron (ORIC). Computations of ion paths for beam injection from the new tandem into ORIC require field mapping in the regions traversed by the beam. Additional field data is also desired for the higher levels (approx.19 kG) now used for most heavy ion beams. The magnetic field measurement system uses 39 flip coil/current integrator sets with computer controlled data scanning. The coils are spaced radially at 1 inch intervals in an arm which can be rotated azimuthally in 2 degree increments. The entire flip coil assembly can be shifted to larger radii to measure fields beyond the pole boundary. Temperature stabilization of electronic circuitry permits a measurement resolution of +-1 gauss over a dynamic range of +-25,000 gauss. The system will process a scan of 8000 points in about one hour

  5. Anomalous transport of magnetized electrons interacting with EC waves

    Energy Technology Data Exchange (ETDEWEB)

    Tsironis, C; Vlahos, L [Section of Astrophysics, Astronomy and Mechanics, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2005-01-01

    We consider the nonlinear interaction of magnetized electrons with an oblique narrow-band electromagnetic wave-packet. The interaction is analysed over and near the local threshold to chaos. The statistical character of the forcing that controls the trajectories of the particles is also studied. We focus our analysis on issues related to energy and spatial diffusion across the magnetic field by following the evolution of the ensemble mean squares (({gamma} - {gamma}{sub 0}){sup 2}) and ((r{sub perpendicular}-r{sub perpendicular0}){sup 2}) for various values of the wave amplitude and angle of wave propagation. We study, in particular, the interaction of magnetized electrons with waves having strong and moderate amplitudes, near the transition to chaos, where the dynamics is complex and a mixture of periodic and stochastic orbits coexist. The electron diffusions in real and energy spaces are found to obey simple power laws in time, and the scaling exponents are indicative of sub-diffusion. This is a direct consequence of the effect of the resonant phase-space islands in the particle motion.

  6. Diffusive heat transport across magnetic islands and stochastic layers in tokamaks

    International Nuclear Information System (INIS)

    Hoelzl, Matthias

    2010-01-01

    Heat transport in tokamak plasmas with magnetic islands and ergodic field lines was simulated at realistic plasma parameters in realistic tokamak geometries. This requires the treatment of anisotropic heat diffusion, which is more efficient along magnetic field lines by up to ten orders of magnitude than perpendicular to them. Comparisons with analytical predictions and experimental measurements allow to determine the stability properties of neoclassical tearing modes as well as the experimental heat diffusion anisotropy.

  7. Fully Relativistic Temperature-Dependent Electronic Transport Properties of Magnetic Alloys From the First Principles.

    Czech Academy of Sciences Publication Activity Database

    Wagenknecht, David; Carva, K.; Turek, Ilja

    2017-01-01

    Roč. 53, č. 11 (2017), č. článku 1700205. ISSN 0018-9464 R&D Projects: GA ČR GA15-13436S Institutional support: RVO:68081723 Keywords : electronic transport * magnetic alloys * ab initio theory Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.243, year: 2016

  8. FFTF Heat Transport System (HTS) component and system design

    International Nuclear Information System (INIS)

    Young, M.W.; Edwards, P.A.

    1980-01-01

    The FFTF Heat Transport Systems and Components designs have been completed and successfully tested at isothermal conditions up to 427 0 C (800 0 F). General performance has been as predicted in the design analyses. Operational flexibility and reliability have been outstanding throughout the test program. The components and systems have been demonstrated ready to support reactor powered operation testing planned later in 1980

  9. Nonlinear transport behavior of low dimensional electron systems

    Science.gov (United States)

    Zhang, Jingqiao

    The nonlinear behavior of low-dimensional electron systems attracts a great deal of attention for its fundamental interest as well as for potentially important applications in nanoelectronics. In response to microwave radiation and dc bias, strongly nonlinear electron transport that gives rise to unusual electron states has been reported in two-dimensional systems of electrons in high magnetic fields. There has also been great interest in the nonlinear response of quantum ballistic constrictions, where the effects of quantum interference, spatial dispersion and electron-electron interactions play crucial roles. In this thesis, experimental results of the research of low dimensional electron gas systems are presented. The first nonlinear phenomena were observed in samples of highly mobile two dimensional electrons in GaAs heavily doped quantum wells at different magnitudes of DC and AC (10 KHz to 20 GHz) excitations. We found that in the DC excitation regime the differential resistance oscillates with the DC current and external magnetic field, similar behavior was observed earlier in AlGaAs/GaAs heterostructures [C.L. Yang et al. ]. At external AC excitations the resistance is found to be also oscillating as a function of the magnetic field. However the form of the oscillations is considerably different from the DC case. We show that at frequencies below 100 KHz the difference is a result of a specific average of the DC differential resistance during the period of the external AC excitations. Secondly, in similar samples, strong suppression of the resistance by the electric field is observed in magnetic fields at which the Landau quantization of electron motion occurs. The phenomenon survives at high temperatures at which the Shubnikov de Haas oscillations are absent. The scale of the electric fields essential for the effect, is found to be proportional to temperature in the low temperature limit. We suggest that the strong reduction of the longitudinal resistance

  10. Heavy particle transport in sputtering systems

    Science.gov (United States)

    Trieschmann, Jan

    2015-09-01

    This contribution aims to discuss the theoretical background of heavy particle transport in plasma sputtering systems such as direct current magnetron sputtering (dcMS), high power impulse magnetron sputtering (HiPIMS), or multi frequency capacitively coupled plasmas (MFCCP). Due to inherently low process pressures below one Pa only kinetic simulation models are suitable. In this work a model appropriate for the description of the transport of film forming particles sputtered of a target material has been devised within the frame of the OpenFOAM software (specifically dsmcFoam). The three dimensional model comprises of ejection of sputtered particles into the reactor chamber, their collisional transport through the volume, as well as deposition of the latter onto the surrounding surfaces (i.e. substrates, walls). An angular dependent Thompson energy distribution fitted to results from Monte-Carlo simulations is assumed initially. Binary collisions are treated via the M1 collision model, a modified variable hard sphere (VHS) model. The dynamics of sputtered and background gas species can be resolved self-consistently following the direct simulation Monte-Carlo (DSMC) approach or, whenever possible, simplified based on the test particle method (TPM) with the assumption of a constant, non-stationary background at a given temperature. At the example of an MFCCP research reactor the transport of sputtered aluminum is specifically discussed. For the peculiar configuration and under typical process conditions with argon as process gas the transport of aluminum sputtered of a circular target is shown to be governed by a one dimensional interaction of the imposed and backscattered particle fluxes. The results are analyzed and discussed on the basis of the obtained velocity distribution functions (VDF). This work is supported by the German Research Foundation (DFG) in the frame of the Collaborative Research Centre TRR 87.

  11. National Space Transportation System (NSTS) technology needs

    Science.gov (United States)

    Winterhalter, David L.; Ulrich, Kimberly K.

    1990-01-01

    The National Space Transportation System (NSTS) is one of the Nation's most valuable resources, providing manned transportation to and from space in support of payloads and scientific research. The NSTS program is currently faced with the problem of hardware obsolescence, which could result in unacceptable schedule and cost impacts to the flight program. Obsolescence problems occur because certain components are no longer being manufactured or repair turnaround time is excessive. In order to achieve a long-term, reliable transportation system that can support manned access to space through 2010 and beyond, NASA must develop a strategic plan for a phased implementation of enhancements which will satisfy this long-term goal. The NSTS program has initiated the Assured Shuttle Availability (ASA) project with the following objectives: eliminate hardware obsolescence in critical areas, increase reliability and safety of the vehicle, decrease operational costs and turnaround time, and improve operational capability. The strategy for ASA will be to first meet the mandatory needs - keep the Shuttle flying. Non-mandatory changes that will improve operational capability and enhance performance will then be considered if funding is adequate. Upgrade packages should be developed to install within designated inspection periods, grouped in a systematic approach to reduce cost and schedule impacts, and allow the capability to provide a Block 2 Shuttle (Phase 3).

  12. Permanent magnet system to guide superparamagnetic particles

    Science.gov (United States)

    Baun, Olga; Blümler, Peter

    2017-10-01

    A new concept of using permanent magnet systems for guiding superparamagnetic nano-particles on arbitrary trajectories over a large volume is proposed. The basic idea is to use one magnet system which provides a strong, homogeneous, dipolar magnetic field to magnetize and orient the particles, and a second constantly graded, quadrupolar field, superimposed on the first, to generate a force on the oriented particles. In this configuration the motion of the particles is driven predominantly by the component of the gradient field which is parallel to the direction of the homogeneous field. As a result, particles are guided with constant force and in a single direction over the entire volume. The direction is simply adjusted by varying the angle between quadrupole and dipole. Since a single gradient is impossible due to Gauß' law, the other gradient component of the quadrupole determines the angular deviation of the force. However, the latter can be neglected if the homogeneous field is stronger than the local contribution of the quadrupole field. A possible realization of this idea is a coaxial arrangement of two Halbach cylinders. A dipole to evenly magnetize and orient the particles, and a quadrupole to generate the force. The local force was calculated analytically for this particular geometry and the directional limits were analyzed and discussed. A simple prototype was constructed to demonstrate the principle in two dimensions on several nano-particles of different size, which were moved along a rough square by manual adjustment of the force angle. The observed velocities of superparamagnetic particles in this prototype were always several orders of magnitude higher than the theoretically expected value. This discrepancy is attributed to the observed formation of long particle chains as a result of their polarization by the homogeneous field. The magnetic moment of such a chain is then the combination of that of its constituents, while its hydrodynamic radius

  13. Study on optimization design of superconducting magnet for magnetic force assisted drug delivery system

    International Nuclear Information System (INIS)

    Fukui, S.; Abe, R.; Ogawa, J.; Oka, T.; Yamaguchi, M.; Sato, T.; Imaizumi, H.

    2007-01-01

    Analytical study on the design of the superconducting magnet for the magnetic force assisted drug delivery system is presented in this paper. The necessary magnetic field condition to reside the magnetic drug particle in the blood vessels is determined by analyzing the particle motion in the blood vessel. The design procedure of the superconducting magnet for the M-DDS is presented and some case studies are conducted. The analytical results show that the superconducting magnet to satisfy the magnetic field conduction for the M-DDS is practically feasible

  14. Electronic and magnetic phase separation in EuB6. Fluctuation spectroscopy and nonlinear transport

    International Nuclear Information System (INIS)

    Amyan, Adham

    2013-01-01

    The main topics of this thesis are electrical, stationary, and time-resolved transport measurements on EuB 6 as well as the further development of measuring methods and analysis procedures of the fluctuation spectroscopy. The first part of this thesis was dedicated to the further development of the already known measuring methods under application of a fast data-acquisition card. The second part deals with the electrical transport properties of EuB 6 and the understanding of the coupling between charge and magnetic degrees of freedom. By means of resistance and nonlinear-transport measurements as well as fluctuation spectroscopy hypotheses of other scientists were systematically verified as well as new knowledge obtained. The magnetoresistance was studied as function of the temperature in small external magnetic fields between 1 mT and 700 mT. Measurements of the third harmonic resistance as function of the temperature show maxima at T MI and T C . Electrical-resistance fluctuations were measured without external magnetic field between 5 and 100 K as well in presence of a magnetic field between 18 K and 32 K. At constant temperature measurements of the spectral power density in external magnetic fields were performed in the temperature range from 18 K to 32 K. Highly resolving measurements of the thermal expansion coefficient showed a very strong coupling of the magnetic (polaronic) degrees of freedom to the crystal lattice.

  15. Magnetic and electrical transport properties of delta-doped amorphous Ge:Mn magnetic semiconductors

    International Nuclear Information System (INIS)

    Li, H.L.; Lin, H.T.; Wu, Y.H.; Liu, T.; Zhao, Z.L.; Han, G.C.; Chong, T.C.

    2006-01-01

    We report on the growth and characterization of delta-doped amorphous Ge:Mn diluted magnetic semiconductor thin films on GaAs (0 0 1) substrates. The fabricated samples exhibit different magnetic behaviors, depending on the Mn doping concentration. The Curie temperature was found to be dependent on both the Mn doping concentration and spacing between the doping layers. A sharp drop in magnetization and rise in resistivity are observed at low temperature in samples with high Mn doping concentrations, which is also accompanied by a negative thermal remanent magnetization (TRM) in the higher temperature range. The temperature at which the magnetization starts to drop and the negative TRM appears show a correlation with the Mn doping concentration. The experimental results are discussed based on the formation of ferromagnetic regions at high temperature and antiferromagnetic coupling between these regions at low temperature

  16. First-principles calculation of transport property in nano-devices under an external magnetic field

    International Nuclear Information System (INIS)

    Chen Jingzhe; Zhang Jin; Han Rushan

    2008-01-01

    The mesoscopic quantum interference phenomenon (QIP) can be observed and behaves as the oscillation of conductance in nano-devices when the external magnetic field changes. Excluding the factor of impurities or defects, specific QIP is determined by the sample geometry. We have improved a first-principles method based on the matrix Green's function and the density functional theory to simulate the transport behaviour of such systems under a magnetic field. We have studied two kinds of QIP: universal conductance fluctuation (UCF) and Aharonov–Bohm effect (A–B effect). We find that the amplitude of UCF is much smaller than the previous theoretical prediction. We have discussed the origin of difference and concluded that due to the failure of ergodic hypothesis, the ensemble statistics is not applicable, and the conductance fluctuation is determined by the flux-dependent density of states (DOSs). We have also studied the relation between the UCF and the structure of sample. For a specific structure, an atomic circle, the A–B effect is observed and the origin of the oscillation is also discussed

  17. Transport in low-dimensional mesoscopic systems

    Energy Technology Data Exchange (ETDEWEB)

    Syzranov, Sergey

    2011-05-05

    The work is devoted to the physics of graphene-based optoelectronics and arrays of Josephson junctions. The first part deals with transport in a graphene p-n junction irradiated by an electromagnetic field. The photocurrent in such device is calculated analytically and compared to those observed in the recent experiments on graphene photodetectors. It is shown that in a clean effectively one-dimensional junction the photocurrent oscillates as a function of gate voltages due to the interference between electron paths accompanied by the resonant photon absorption. The second part of the thesis is devoted to the construction of a Drude-like theory for the transport of Cooper pairs in weakly disordered Josephson networks and to finding the conductivity and the characteristic temperature of the commencement of strong localization. Also, it is shown that the low-temperature superconductor-insulator transition is necessarily of the first order in all 3D and in most 2D systems.

  18. Tomorrow's Transportation Market : Developing an Innovative, Seamless Transportation System

    Science.gov (United States)

    2013-04-17

    With the cost of congestion in the United States estimated to be in the order of $121 billion, transportation planners are under increasing pressure to improve conditions and meet projected demand increases. Harnessing emerging technologies to develo...

  19. Design of a hydraulic ash transport system

    Energy Technology Data Exchange (ETDEWEB)

    Mirgorodskii, V.G.; Mova, M.E.; Korenev, V.E.; Grechikhin, Yu.A. (Donetskii Politekhnicheskii Institut (USSR))

    1990-04-01

    Discusses general design of a hydraulic ash removal system to be employed at the reconstructed six 225 MW blocks of the Mironov State Regional Power Plant in the USSR. The blocks burn low-grade solid fuel with an ash content of up to 40.5%. Large quantities of ash have to be moved from the plant (total ash production 60 t/h, using 570 t/h of water for cooling and moistening). An optimum hydraulic ash transportation system would include a two-section airlift pumping system, shown in a diagram. Technological advantages of using this airlift system are enumerated, including short pipes, reduction in required water quantity and the possibility of siting hydraulic pumps at zero level.

  20. Fluid description of particle transport in hf heated magnetized plasma

    International Nuclear Information System (INIS)

    Klima, R.

    1980-01-01

    Particle fluxes averaged over high-frequency oscillations are analyzed. The collisional effects and the kinetic mechanisms of energy absorption are included. Spatial dependences of both the high-frequency and the (quasi-)steady electromagnetic fields are arbitrary. The equations governing the fluxes are deduced from the moments of the averaged kinetic equation. Explicit expressions for steady state fluxes are given in terms of electromagnetic field quantities. The results can also be applied to anomalous transport phenomena in weakly turbulent plasmas. (author)