WorldWideScience

Sample records for a-1 reactor calder hall

  1. Prospects of steady state magnetic diagnostic of fusion reactors based on metallic Hall sensors

    Science.gov (United States)

    Ďuran, I.; Sentkerestiová, J.; Kovařík, K.; Viererbl, L.

    2012-06-01

    Employment of sensors based on Hall effect (Hall sensors) is one of the candidate approaches to detection of almost steady state magnetic fields in future fusion reactors based on magnetic confinement (tokamaks, stellarators etc.), and also in possible fusion-fission hybrid systems having these fusion reactors as a neutron source and driver. This contribution reviews the initial considerations concerning application of metallic Hall sensors in fusion reactor harsh environment that include high neutron loads (>1018 cm-2) and elevated temperatures (>200°C). In particular, the candidate sensing materials, candidate technologies for sensors production, initial analysis of activation and transmutation of sensors under reactor relevant neutron loads and the tests of the the first samples of copper Hall sensors are presented.

  2. Optimal Protection of Reactor Hall Under Nuclear Fuel Container Drop Using Simulation Methods

    Directory of Open Access Journals (Sweden)

    Králik Juraj

    2014-12-01

    Full Text Available This paper presents of the optimal design of the damping devices cover of reactor hall under impact of nuclear fuel container drop of type TK C30. The finite element idealization of nuclear power plant structure is used in software ANSYS. The steel pipe damper system is proposed for dissipation of the kinetic energy of the container free fall in comparison with the experimental results. The probabilistic and sensitivity analysis of the damping devices was considered on the base of the simulation methods in program AntHill using the Monte Carlo method.

  3. Calderón de la Barca y Toledo

    Directory of Open Access Journals (Sweden)

    Colomina Torner, Jaime

    2001-12-01

    Full Text Available In the last Year 2000, it was expired the fourth Centenary of Pedro Calderón de la Barca's birth. On the ocassion of this, He was remembered with several ceremonies in Spain. In Toledo the Royal Academy of FineArts and Historic Science, and the Cathedral Chapter give Him a great homage in the Royal Chapel in what occuped a post and job, being priest in 1653. The author of this biographic note participated in this homage, and when he looked into in same archives he found these dates that here are published apparently unknown, and they light up aspects of His biography.En el pasado año 2000 se cumplió el IV centenario del nacimiento de D. Pedro Calderón de la Barca. Con este motivo fue recordado en España con diversos actos. En Toledo, la Real Academia de B. Artes y C. Históricas y el Cabildo de la catedral le tributaron un solemne homenaje en la misma Real Capilla en la que ocupó una plaza, siendo ya sacerdote, a partir de 1653. El autor de esta nota biográfica participó en dicho homenaje, y al investigar en varios archivos halló estos datos, que aquí se publican, al parecer, inéditos y que iluminan aspectos de su biografía.

  4. Description of the magnox type of gas cooled reactor (MAGNOX)

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, S.E.; Nonboel, E

    1999-05-01

    The present report comprises a technical description of the MAGNOX type of reactor as it has been build in Great Britain. The Magnox reactor is gas cooled (CO{sub 2}) with graphite moderators. The fuels is natural uranium in metallic form, canned with a magnesium alloy called 'Magnox'. The Calder Hall Magnox plant on the Lothian coastline of Scotland, 60 km east of Edinburgh, has been chosen as the reference plant and is described in some detail. Data on the other stations are given in tables with a summary of design data. Special design features are also shortly described. Where specific data for Calder Hall Magnox has not been available, corresponding data from other Magnox plants has been used. The information presented is based on the open literature. The report is written as a part of the NKS/RAK-2 sub-project 3: 'Reactors in Nordic Surroundings', which comprises a description of nuclear power plants neighbouring the Nordic countries. (au)

  5. First Calderón Prize

    Science.gov (United States)

    Rundell, William; Somersalo, Erkki

    2008-07-01

    The Inverse Problems International Association (IPIA) awarded the first Calderón Prize to Matti Lassas for his outstanding contributions to the field of inverse problems, especially in geometric inverse problems. The Calderón Prize is given to a researcher under the age of 40 who has made distinguished contributions to the field of inverse problems broadly defined. The first Calderón Prize Committee consisted of Professors Adrian Nachman, Lassi Päivärinta, William Rundell (chair), and Michael Vogelius. William Rundell For the Calderón Prize Committee Prize ceremony The ceremony awarding the Calderón Prize. Matti Lassas is on the left. He and William Rundell are on the right. Photos by P Stefanov. Brief Biography of Matti Lassas Matti Lassas was born in 1969 in Helsinki, Finland, and studied at the University of Helsinki. He finished his Master's studies in 1992 in three years and earned his PhD in 1996. His PhD thesis, written under the supervision of Professor Erkki Somersalo was entitled `Non-selfadjoint inverse spectral problems and their applications to random bodies'. Already in his thesis, Matti demonstrated a remarkable command of different fields of mathematics, bringing together the spectral theory of operators, geometry of Riemannian surfaces, Maxwell's equations and stochastic analysis. He has continued to develop all of these branches in the framework of inverse problems, the most remarkable results perhaps being in the field of differential geometry and inverse problems. Matti has always been a very generous researcher, sharing his ideas with his numerous collaborators. He has authored over sixty scientific articles, among which a monograph on inverse boundary spectral problems with Alexander Kachalov and Yaroslav Kurylev and over forty articles in peer reviewed journals of the highest standards. To get an idea of the wide range of Matti's interests, it is enough to say that he also has three US patents on medical imaging applications. Matti is

  6. Mr. Degas and Mr. Calder Go to the Ballet.

    Science.gov (United States)

    Cross, Kate

    2003-01-01

    Describes an art project that taught students about the work of two different artists: (1) Edgar Degas; and (2) Alexander Calder. Explains that students created drawings of ballerinas, created sculptures in the style of Calder, and created sculptures of ballerinas. (CMK)

  7. Reactors

    CERN Document Server

    International Electrotechnical Commission. Geneva

    1988-01-01

    This standard applies to the following types of reactors: shunt reactors, current-limiting reactors including neutral-earthing reactors, damping reactors, tuning (filter) reactors, earthing transformers (neutral couplers), arc-suppression reactors, smoothing reactors, with the exception of the following reactors: small reactors with a rating generally less than 2 kvar single-phase and 10 kvar three-phase, reactors for special purposes such as high-frequency line traps or reactors mounted on rolling stock.

  8. First results and perspectives of CALDER

    Science.gov (United States)

    Vignati, M.; Bellini, F.; Cardani, L.; Casali, N.; Castellano, M. G.; Colantoni, I.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; D`Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.

    2016-07-01

    Large-mass arrays of bolometers proved to be good detectors for Neutrinoless Double Beta Decay (0 νββ) and Dark Matter searches. CUORE and LUCIFER are bolometric 0 νββ experiments which will start to take data in 2016 at Laboratori Nazionali del Gran Sasso in Italy. The sensitivity of CUORE could be increased by removing the background due to α particles, by detecting the small amount of Cherenkov light (100 eV) emitted by the βs' signal and not by αs. LUCIFER could be extended to detect also Dark Matter, provided that the background from β / γ particles (100 eV of scintillation light) is discriminated from nuclear recoils of about 10 keV energy (no light). CALDER is a project to develop light detectors for CUORE, LUCIFER and similar bolometric experiments. The goal is to obtain detectors with an active area of 5×5 cm2 (the face of bolometric crystals), operating at 10 mK, and with a baseline resolution better than 20 eV. We have chosen to develop phonon-mediated devices using Kinetic Inductance Detectors (KIDs). We present the first results and the perspectives of the project.

  9. Fabrication of the CALDER light detectors

    Science.gov (United States)

    Colantoni, I.; Bellini, F.; Cardani, L.; Casali, N.; Castellano, M. G.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; D`Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.; Vignati, M.

    2016-07-01

    CALDER (Cryogenic wide-Area Light Detectors with Excellent Resolution) is a project for the development of large area phonon mediated KIDs (Kinetic Inductance Detectors), for the detection of Cherenkov radiation emitted in TeO2 bolometers to search for neutrinoless double beta decay (0 νββ). The KIDs are superconducting detectors made of high quality factor superconducting resonators, which are coupled to a transmission line for signal readout. We designed and fabricated KIDs using aluminum. The Al thin films (40 nm) were evaporated on Si(100) high resistivity silicon wafers using an electron beam evaporator in a HV chamber. In this work we report the steps of the fabrication process. All devices are made in direct-write using Electron Beam Lithography (EBL), positive tone resist poly-methyl methacrylate (PMMA) and lift off process. In order to improve the sensitivity of the detectors we have started recently to use sub-stoichiometric TiN deposited by means of DC magnetron sputtering and we will optimize a different fabrication process.

  10. The Calderón problem with corrupted data

    Science.gov (United States)

    Caro, Pedro; Garcia, Andoni

    2017-08-01

    We consider the inverse Calderón problem consisting of determining the conductivity inside a medium by electrical measurements on its surface. Ideally, these measurements determine the Dirichlet-to-Neumann map and, therefore, one usually assumes the data to be given by such a map. This situation corresponds to having access to infinite-precision measurements, which is totally unrealistic. In this paper, we study the Calderón problem assuming the data to contain measurement errors and provide formulas to reconstruct the conductivity and its normal derivative on the surface. Additionally, we state the rate convergence of the method. Our approach is theoretical and has a stochastic flavour.

  11. Secrets in Calderón. Analyses of Some Secrecy Aspects in Calderón’s Comedies

    Directory of Open Access Journals (Sweden)

    Simon Kroll

    2015-05-01

    Full Text Available Spanish Golden Age Culture is an age of secrets and secrecy. Among its playwrights, Pedro Calderón de la Barca shows the most complex comprehension of this subject. During the entirety of his career he refers to it in numerous comedies, creates metaphors concerning different aspects of secrecy and employs it for the construction of his comedias de enredo/comedies of intrigue. In summary: Calderón has an ongoing interest in this anthropological phenomenon. The article analyses the motive of secrecy in selected plays, tragic and comic, starting with the San Secreto figure present in different plays, for example in La vida es sueño. After tracing the temporal aspect of secrecy the article ends with some thoughts about the relation between the public and the secret spheres. Calderón reflects this relation in his masterpiece concerning secrecy: El secreto a voces/The loud secret.

  12. The Calderón projection: New definition and applications

    Science.gov (United States)

    Booß-Bavnbek, Bernhelm; Lesch, Matthias; Zhu, Chaofeng

    2009-07-01

    We consider an arbitrary linear elliptic first-order differential operator A with smooth coefficients acting between sections of complex vector bundles E,F over a compact smooth manifold M with smooth boundary Σ. We describe the analytic and topological properties of A in a collar neighborhood U of Σ and analyze various ways of writing A ↾ U in product form. We discuss the sectorial projections of the corresponding tangential operator, construct various invertible doubles of A by suitable local boundary conditions, obtain Poisson type operators with different mapping properties, and provide a canonical construction of the Calderón projection. We apply our construction to generalize the Cobordism Theorem and to determine sufficient conditions for continuous variation of the Calderón projection and of well-posed self-adjoint Fredholm extensions under continuous variation of the data.

  13. Eduardo Caballero Calderón en la Biblioteca

    OpenAIRE

    Boletín Cultural y Bibliográfico Banco de la República

    2003-01-01

    Como parte complementaria de la información de este Boletín, queremos incluir, después de  realizar una revisión del catálogo en línea de la Biblioteca Luis Ángel Arango, la lista de libros y artículos publicados por Eduardo Caballero  Calderón

  14. Boundedness of Calderón-Zygmund operators in product Hardy spaces

    Institute of Scientific and Technical Information of China (English)

    HAN Yong-sheng; YANG Da-chun

    2009-01-01

    By means of vector-valued product Calderón-Zygmund operators and some subtle estimates, the boundedness in product Hardy spaces on Rn × Rm of Calderón-Zygmund operators introduced by J. L. Journé is established.

  15. Strongly Singular Calderón-Zygmund Operator and Commutator on Morrey Type Spaces

    Institute of Scientific and Technical Information of China (English)

    Yan LIN

    2007-01-01

    In this paper, the author considers the boundedness of strongly singular Calderón-Zygmund operator and commutator generated by this operator and Lipschitz function on the classical Morrey space and generalized Morrey space. Moreover, the boundedness of strongly singular CalderónZygmund operator on the predual of Morrey space is discussed.

  16. Characterization of the KID-Based Light Detectors of CALDER

    Science.gov (United States)

    Casali, N.; Bellini, F.; Cardani, L.; Castellano, M. G.; Colantoni, I.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; D'Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.; Vignati, M.

    2016-07-01

    The aim of the Cryogenic wide-Area Light Detectors with Excellent Resolution (CALDER) project is the development of light detectors with active area of 5 × 5 cm2 and noise energy resolution smaller than 20 eV RMS, implementing phonon-mediated kinetic inductance detectors. The detectors are developed to improve the background suppression in large-mass bolometric experiments such as CUORE, via the double read-out of the light and the heat released by particles interacting in the bolometers. In this work, we present the characterization of the first light detectors developed by CALDER. We describe the analysis tools to evaluate the resonator parameters (resonant frequency and quality factors) taking into account simultaneously all the resonance distortions introduced by the read-out chain (as the feed-line impedance and its mismatch) and by the power stored in the resonator itself. We detail the method for the selection of the optimal point for the detector operation (maximizing the signal-to-noise ratio). Finally, we present the response of the detector to optical pulses in the energy range of 0{-}30 keV.

  17. Characterization of the KID-Based Light Detectors of CALDER

    CERN Document Server

    Casali, N; Cardani, L; Castellano, M G; Colantoni, I; Coppolecchia, A; Cosmelli, C; Cruciani, A; D'Addabbo, A; Di Dominio, S; Martinez, M; Tomei, C; Vignati, M

    2015-01-01

    The aim of the Cryogenic wide-Area Light Detectors with Excellent Resolution (CALDER) project is the development of light detectors with active area of $5\\times5$ cm$^2$ and noise energy resolution smaller than 20 eV RMS, implementing phonon-mediated kinetic inductance detectors. The detectors are developed to improve the background suppression in large-mass bolometric experiments such as CUORE, via the double read-out of the light and the heat released by particles interacting in the bolometers. In this work, we present the characterization of the first light detectors developed by CALDER. We describe the analysis tools to evaluate the resonator parameters (resonant frequency and quality factors) taking into account simultaneously all the resonance distortions introduced by the read-out chain (as the feed-line impedance and its mismatch) and by the power stored in the resonator itself. We detail the method for the selection of the optimal point for the detector operation (maximizing the signal-to-noise ratio...

  18. CALDER: cryogenic light detector for rare events search

    CERN Document Server

    Pagnanini, L; Bellini, F; Calvo, M; Cardani, L; Casali, N; Castellano, M G; Colantoni, I; Coppolecchia, A; Cosmelli, C; Cruciani, A; De Bernardis, P; Di Domizio, S; D'Addabbo, A; Martinez, M; Masi, S; Tomei, C; Vignati, M

    2015-01-01

    The CALDER project aims at developing cryogenic light detectors with high sensitivity to UV and visible light, to be used for particle tagging in massive bolometers. Indeed the sensitivity of CUORE can be increased by a factor of 3, thanks to the reduction of the $\\alpha$-background, obtained by detecting the Cherenkov light (100 eV) emitted by $\\beta/\\gamma$ events. Currently used light detectors have not the features required to address this task, so we decided to develop a new light detector using Kinetic Inductance Detector as a sensor. This approach is very challenging and requires an intensive R$\\&$D to be satisfied. The first results of this activity are shown in the following.

  19. EOIL power scaling in a 1-5 kW supersonic discharge-flow reactor

    Science.gov (United States)

    Davis, Steven J.; Lee, Seonkyung; Oakes, David B.; Haney, Julie; Magill, John C.; Paulsen, Dwane A.; Cataldi, Paul; Galbally-Kinney, Kristin L.; Vu, Danthu; Polex, Jan; Kessler, William J.; Rawlins, Wilson T.

    2008-02-01

    Scaling of EOIL systems to higher powers requires extension of electric discharge powers into the kW range and beyond with high efficiency and singlet oxygen yield. We have previously demonstrated a high-power microwave discharge approach capable of generating singlet oxygen yields of ~25% at ~50 torr pressure and 1 kW power. This paper describes the implementation of this method in a supersonic flow reactor designed for systematic investigations of the scaling of gain and lasing with power and flow conditions. The 2450 MHz microwave discharge, 1 to 5 kW, is confined near the flow axis by a swirl flow. The discharge effluent, containing active species including O II(a1Δ g, b1Σ g +), O( 3P), and O 3, passes through a 2-D flow duct equipped with a supersonic nozzle and cavity. I2 is injected upstream of the supersonic nozzle. The apparatus is water-cooled, and is modular to permit a variety of inlet, nozzle, and optical configurations. A comprehensive suite of optical emission and absorption diagnostics is used to monitor the absolute concentrations of O II(a), O II(b), O( 3P), O 3, I II, I(2P 3/2), I(2P 1/2), small-signal gain, and temperature in both the subsonic and supersonic flow streams. We discuss initial measurements of singlet oxygen and I* excitation kinetics at 1 kW power.

  20. Hall C

    Data.gov (United States)

    Federal Laboratory Consortium — Hall C's initial complement of equipment (shown in the figure), includes two general-purpose magnetic spectrometers. The High Momentum Spectrometer (HMS) has a large...

  1. Hall A

    Data.gov (United States)

    Federal Laboratory Consortium — The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electroand photo-induced reactions at very high luminosity...

  2. CALDER: Cryogenic light detectors for background-free searches

    Science.gov (United States)

    Cardani, L.; Bellini, F.; Casali, N.; Castellano, M. G.; Colantoni, I.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; Di Domizio, S.; Tomei, C.; Vignati, M.

    2015-08-01

    The development of background-free detectors is essential for experiments searching for rare events. Bolometers, that are among the most competitive devices for the study of neutrino-less double beta decay (0νDBD) and Dark Matter interactions, suffer from the absence of techniques that allow to identify the nature of the interacting particles. This limit can be overcome by coupling the bolometer to an independent device for the measurement of the light emitted by interactions, as the combined read-out of the bolometric and light signals allows to identify and reject particles different from those of interest. CUORE, the most advanced bolometric experiment for 0νDBD searches, could disentangle the electrons produced by 0νDBD from the dangerous background due to α particles, by measuring the (tiny) Cherenkov light emitted by electrons and not by α's. LUCIFER, a project based on ZnSe scintillating bolometers for the study of 82Se 0νDBD, would be competitive also in the search of Dark Matter interactions if equipped with light detectors that allow to distinguish and reject the background due to electrons and γ's. These advances require cryogenic detectors characterized by noise lower than 20 eV, large active area, wide temperature range of operation, high radio-purity and ease in fabricating hundreds of channels. The CALDER collaboration aims to develop such detectors by exploiting the superb energy resolution and natural multiplexed read-out provided by Kinetic Inductance Detectors.

  3. Reactor

    Science.gov (United States)

    Evans, Robert M.

    1976-10-05

    1. A neutronic reactor having a moderator, coolant tubes traversing the moderator from an inlet end to an outlet end, bodies of material fissionable by neutrons of thermal energy disposed within the coolant tubes, and means for circulating water through said coolant tubes characterized by the improved construction wherein the coolant tubes are constructed of aluminum having an outer diameter of 1.729 inches and a wall thickness of 0.059 inch, and the means for circulating a liquid coolant through the tubes includes a source of water at a pressure of approximately 350 pounds per square inch connected to the inlet end of the tubes, and said construction including a pressure reducing orifice disposed at the inlet ends of the tubes reducing the pressure of the water by approximately 150 pounds per square inch.

  4. CALDER: Cryogenic light detectors for background-free searches

    Energy Technology Data Exchange (ETDEWEB)

    Cardani, L. [Dipartimento di Fisica - Sapienza Università di Roma, Roma - Italy and Physics Department, Princeton University, Princeton, NJ (United States); Bellini, F.; Casali, N.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; Vignati, M. [Dipartimento di Fisica - Sapienza Università di Roma and INFN - Sezione di Roma, Roma - Italy (Italy); Castellano, M. G. [Istituto di Fotonica e Nanotecnologie - CNR, Roma - Italy (Italy); Colantoni, I. [Dipartimento di Fisica - Sapienza Università di Roma (Italy); Di Domizio, S. [Dipartimento di Fisica, Università di Genova, Genova - Italy and INFN Sezione di Genova, Genova - Italy (Italy); Tomei, C. [INFN - Sezione di Roma, Roma - Italy (Italy)

    2015-08-17

    The development of background-free detectors is essential for experiments searching for rare events. Bolometers, that are among the most competitive devices for the study of neutrino-less double beta decay (0νDBD) and Dark Matter interactions, suffer from the absence of techniques that allow to identify the nature of the interacting particles. This limit can be overcome by coupling the bolometer to an independent device for the measurement of the light emitted by interactions, as the combined read-out of the bolometric and light signals allows to identify and reject particles different from those of interest. CUORE, the most advanced bolometric experiment for 0νDBD searches, could disentangle the electrons produced by 0νDBD from the dangerous background due to α particles, by measuring the (tiny) Cherenkov light emitted by electrons and not by α’s. LUCIFER, a project based on ZnSe scintillating bolometers for the study of {sup 82}Se 0νDBD, would be competitive also in the search of Dark Matter interactions if equipped with light detectors that allow to distinguish and reject the background due to electrons and γ’s. These advances require cryogenic detectors characterized by noise lower than 20 eV, large active area, wide temperature range of operation, high radio-purity and ease in fabricating hundreds of channels. The CALDER collaboration aims to develop such detectors by exploiting the superb energy resolution and natural multiplexed read-out provided by Kinetic Inductance Detectors.

  5. Definiendo las reglas del juego: Calderón y el espacio virtual

    OpenAIRE

    López-Martín, F.J. (Francisco Javier)

    2012-01-01

    Se presenta el modo en que Calderón involucra al espectador en La vida es sueño y Eco y Narciso haciéndole vivir una realidad imaginaria y se compara con el uso de la información y la intervención activa del público en videojuegos masivos como Diablo,World of Warcraft y Second Life, que tratan de reproducir algún aspecto de la realidad. Pese a la contemporaneidad del concepto de la «realidad virtual» se mantiene que Calderón, tres siglos antes, ya exploró distintos recursos para conseguir que...

  6. High-Order Calderón Preconditioned Time Domain Integral Equation Solvers

    KAUST Repository

    Valdes, Felipe

    2013-05-01

    Two high-order accurate Calderón preconditioned time domain electric field integral equation (TDEFIE) solvers are presented. In contrast to existing Calderón preconditioned time domain solvers, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of fully-localized high-order div-and quasi curl-conforming (DQCC) basis functions. Numerical results demonstrate that the linear systems of equations obtained using the proposed basis functions converge rapidly, regardless of the mesh density and of the order of the current expansion. © 1963-2012 IEEE.

  7. Two Step Procedure Using a 1-D Slab Spectral Geometry in a Pebble Bed Reactor Core Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Chul; Kim, Kang Seog; Noh, Jae Man; Joo, Hyung Kook [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    A strong spectral interaction between the core and the reflector has been one of the main concerns in the analysis of pebble bed reactor cores. To resolve this problem, VSOP adopted iteration between the spectrum calculation in a spectral zone and the global core calculation. In VSOP, the whole problem domain is divided into many spectral zones in which the fine group spectrum is calculated using bucklings for fast groups and albedos for thermal groups from the global core calculation. The resulting spectrum in each spectral zone is used to generate broad group cross sections of the spectral zone for the global core calculation. In this paper, we demonstrate a two step procedure in a pebble bed reactor core analysis. In the first step, we generate equivalent cross sections from a 1-D slab spectral geometry model with the help of the equivalence theory. The equivalent cross sections generated in this way include the effect of the spectral interaction between the core and the reflector. In the second step, we perform a diffusion calculation using the equivalent cross sections generated in the first step. A simple benchmark problem derived from the PMBR-400 Reactor was introduced to verify this approach. We compared the two step solutions with the Monte Carlo (MC) solutions for the problem.

  8. A Direct Numerical Reconstruction Algorithm for the 3D Calderón Problem

    DEFF Research Database (Denmark)

    Delbary, Fabrice; Hansen, Per Christian; Knudsen, Kim

    2011-01-01

    In three dimensions Calderón's problem was addressed and solved in theory in the 1980s in a series of papers, but only recently the numerical implementation of the algorithm was initiated. The main ingredients in the solution of the problem are complex geometrical optics solutions to the conducti...

  9. Kadec-Klee Properties of Calderón-Lozanovskiĭ Function Spaces

    Directory of Open Access Journals (Sweden)

    Paweł Kolwicz

    2012-01-01

    Next, we shall give full criteria for Kadec-Klee properties with respect to global (local convergence in measure in Calderón-Lozanovskiĭ function spaces. In particular, we obtain the full characterizations of Kadec-Klee properties in Orlicz-Lorentz function spaces, which have not been presented until now.

  10. Mujer y travestismo en el teatro de Calderón

    Directory of Open Access Journals (Sweden)

    Escalonilla López, Rosa Ana

    2001-06-01

    Full Text Available After a brief exposition regarding the situation, Calderón's recourse to travestism appears as the symbol of this theatre, mechanism of ideological transmission and unifying element of the whole of this dramatic production (profane, sacramental and brief. The ideological aspect is analysed and therein its relationship with womanhood. Herewith Calderón appears as a forerunner of modernism, since femenine roles distort the restriction imposed by a baroque society. As a result of travestism. Calderón's women do not fit the epoch's stereotypes. They transgress the activities and spaces assigned to their sex, protecting their honour and facing male authority. Definitely, women behave as complete human beings in equal condition to men.Tras una breve exposición del estado de la cuestión, se contempla el recurso del travestismo en Calderón desde su consideración como símbolo de su teatro, mecanismo de transmisión ideológica y elemento unificador de toda su dramaturgia (profana, sacramental y breve. Se analiza el aspecto ideológico y, dentro de éste, la conexión con el tema de la mujer. Calderón se nos revela, así, como precursor de la modernidad, pues los papeles femeninos violentan las restricciones impuestas por la sociedad barroca. Gracias al travestismo, las mujeres calderonianas se sitúan fuera de los estereotipos de la época, transgreden las actividades y los espacios destinados a su sexo, defienden su propio honor y se enfrentan a la autoridad masculina. La mujer es presentada, en definitiva, como un ser humano completo en igualdad de condiciones con el hombre.

  11. Healthy Dining Hall Eating

    Science.gov (United States)

    ... A Week of Healthy Breakfasts Shyness Healthy Dining Hall Eating KidsHealth > For Teens > Healthy Dining Hall Eating ... likely to eat. previous continue Overcoming Common Dining Hall Mistakes Even the most attentive diners can still ...

  12. On Property () in Banach Lattices, Calderón–Lozanowskiĭ and Orlicz–Lorentz Spaces

    Indian Academy of Sciences (India)

    Paweł Kolwicz

    2001-08-01

    The geometry of Calderón–Lozanowskiĭ spaces, which are strongly connected with the interpolation theory, was essentially developing during the last few years (see [4, 9, 10, 12, 13, 17]). On the other hand many authors investigated property () in Banach spaces (see [7, 19, 20, 21, 25, 26]). The first aim of this paper is to study property () in Banach function lattices. Namely a criterion for property () in Banach function lattice is presented. In particular we get that in Banach function lattice property () implies uniform monotonicity. Moreover, property () in generalized Calderón–Lozanowskiĭ function spaces is studied. Finally, it is shown that in Orlicz–Lorentz function spaces property () and uniform convexity coincide.

  13. $L^p$-Continuity for Calderón–Zygmund Operator

    Indian Academy of Sciences (India)

    Q X Yang

    2005-05-01

    Given a Calderón–Zygmund (- for short) operator , which satisfies Hörmander condition, we prove that: if maps all the characteristic atoms to $W L^1$, then is continuous from $L^p$ to $L^p(1 < p < ∞)$. So the study of strong continuity on arbitrary function in $L^p$ has been changed into the study of weak continuity on characteristic functions.

  14. The Calderón Problem with Partial Data for Conductivities with 3/2 Derivatives

    Science.gov (United States)

    Krupchyk, Katya; Uhlmann, Gunther

    2016-11-01

    We extend a global uniqueness result for the Calderón problem with partial data, due to Kenig-Sjöstrand-Uhlmann (Ann. Math. (2) 165:567-591, 2007), to the case of less regular conductivities. Specifically, we show that in dimensions {n ≥ 3}, the knowledge of the Diricihlet-to-Neumann map, measured on possibly very small subsets of the boundary, determines uniquely a conductivity having essentially 3/2 derivatives in an L 2 sense.

  15. A calderón multiplicative preconditioner for the combined field integral equation

    KAUST Repository

    Bagci, Hakan

    2009-10-01

    A Calderón multiplicative preconditioner (CMP) for the combined field integral equation (CFIE) is developed. Just like with previously proposed Caldern-preconditioned CFIEs, a localization procedure is employed to ensure that the equation is resonance-free. The iterative solution of the linear system of equations obtained via the CMP-based discretization of the CFIE converges rapidly regardless of the discretization density and the frequency of excitation. © 2009 IEEE.

  16. Acalasia: estudio de 27 casos en el Hospital Calderón Guardia

    Directory of Open Access Journals (Sweden)

    José A. Mainieri-Hidalgo

    2003-03-01

    Full Text Available Se estudiaron en forma retrospectiva los expedientes clínicos de 27 pacientes diagnosticados con acalasia en el Hospital Dr. R. A. Calderón Guardia (HCG vistos durante el período de 11 años comprendido entre 1991 y 2001, encontrando una tasa de 0.3 por 100.000 habitantes la cual es menor que la informada en la literatura. Esto posiblemente debido a que la ausencia en nuestro medio de manometría esofágica dificulta el diagnóstico de pacientes en estadio temprano o con enfermedad leve o moderada. La presentación clínica fue muy similar a la reportada por otros autores con una relación hombre mujer de 1.7 a 1 y edad promedio de 42 años. Los síntomas con un promedio de evolución de 7 años, fueron el más frecuente, la disfagia que se presentó en todos los casos, seguida de vómito, dolor torácico, pérdida de peso y datos de reflujo gastroesofágico. La esofagoscopía y la esofagografía mostraron hallazgos de enfermedad avanzada como dilatación esofágica importante, retención de restos alimentarios y cardias con espasmo que se superó fácilmente al presionar con el endoscopio. El tratamiento que se administró fue solamente médico (Nifedipina o Isorbide a 6 pacientes, dilataciones y tratamiento médico a 7 y quirúrgico (esofagomiotomía a 14, a tres de estos se les agregó un procedimiento anti-reflujo. La evolución se valoró con base en datos clínicos, encontrando que todos los pacientes con tratamiento médico y dilataciones continúan sintomáticos y con tratamiento. De los operados hay uno que ha requerido dilataciones 5 y 9 años después de la intervención, dos que no tuvieron procedimiento anti-reflujo, están en tratamiento por este problema y el resto se encuentran asintomáticos sin que se presentaran complicaciones quirúrgicas.

  17. Un Grand Jour

    CERN Multimedia

    ACE Film

    1956-01-01

    On 17 October 1956, Her Majesty the Queen opened Reactor number 1 at Calder Hall, on the Cumbrian coast in northwest England, bringing into service the world's first industrial scale nuclear power station.The reactor at Calder Hall was a prototype of the Magnox gas cooled reactor(The Queen'speech. Much propagand for atomic energy. Scenes from the construction of the center.)

  18. Lipozyme IM-catalyzed interesterification for the production of margarine fats in a 1 kg scale stirred tank reactor

    DEFF Research Database (Denmark)

    Zhang, Hong; Xu, Xuebing; Mu, Huiling

    2000-01-01

    Lipozyme IM-catalyzed interesterification of the oil blend between palm stearin and coconut oil (75/25 w/w) was studied for the production of margarine fats in a 1 kg scale batch stirred tank reactor. Parameters such as lipase load, water content, temperature, and reaction time were investigated......, 42, 44, and 46 increased by 1.1, 1.6, 6.8, 16.7, and 6.5%, respectively, in comparison with the increase of those species after chemical interesterification, 0.2, 1.5, 6.5, 17.0, and 9.2%, respectively. Lipase load and reaction time had great influence on the degree of interesterification. A Lipozyme...... by equivalent carbon number (ECN), namely ECN34, 36, 48, and 50, decreased by 6.0, 5.9, 5,8, and 13.7%, respectively, after enzymatic interesterification, similar to the reduction of those species after chemical interesterification, 6.6, 6.0, 7.1, and 12.9%, respectively. On the other hand, those of ECN38, 40...

  19. Lipozyme IM-catalyzed interesterification for the production of margarine fats in a 1 kg scale stirred tank reactor

    DEFF Research Database (Denmark)

    Zhang, Hong; Xu, Xuebing; Mu, Huiling

    2000-01-01

    Lipozyme IM-catalyzed interesterification of the oil blend between palm stearin and coconut oil (75/25 w/w) was studied for the production of margarine fats in a 1 kg scale batch stirred tank reactor. Parameters such as lipase load, water content, temperature, and reaction time were investigated......, 42, 44, and 46 increased by 1.1, 1.6, 6.8, 16.7, and 6.5%, respectively, in comparison with the increase of those species after chemical interesterification, 0.2, 1.5, 6.5, 17.0, and 9.2%, respectively. Lipase load and reaction time had great influence on the degree of interesterification. A Lipozyme...... by equivalent carbon number (ECN), namely ECN34, 36, 48, and 50, decreased by 6.0, 5.9, 5.8, and 13.7%, respectively, after enzymatic interesterification, similar to the reduction of those species after chemical interesterification, 6.6, 6.0, 7.1, and 12.9%, respectively. On the other hand, those of ECN38, 40...

  20. Acalasia: estudio de 27 casos en el Hospital Calderón Guardia

    Directory of Open Access Journals (Sweden)

    José A. Mainieri-Hidalgo

    2003-03-01

    Full Text Available Se estudiaron en forma retrospectiva los expedientes clínicos de 27 pacientes diagnosticados con acalasia en el Hospital Dr. R. A. Calderón Guardia (HCG vistos durante el período de 11 años comprendido entre 1991 y 2001, encontrando una tasa de 0.3 por 100.000 habitantes la cual es menor que la informada en la literatura. Esto posiblemente debido a que la ausencia en nuestro medio de manometría esofágica dificulta el diagnóstico de pacientes en estadio temprano o con enfermedad leve o moderada. La presentación clínica fue muy similar a la reportada por otros autores con una relación hombre mujer de 1.7 a 1 y edad promedio de 42 años. Los síntomas con un promedio de evolución de 7 años, fueron el más frecuente, la disfagia que se presentó en todos los casos, seguida de vómito, dolor torácico, pérdida de peso y datos de reflujo gastroesofágico. La esofagoscopía y la esofagografía mostraron hallazgos de enfermedad avanzada como dilatación esofágica importante, retención de restos alimentarios y cardias con espasmo que se superó fácilmente al presionar con el endoscopio. El tratamiento que se administró fue solamente médico (Nifedipina o Isorbide a 6 pacientes, dilataciones y tratamiento médico a 7 y quirúrgico (esofagomiotomía a 14, a tres de estos se les agregó un procedimiento anti-reflujo. La evolución se valoró con base en datos clínicos, encontrando que todos los pacientes con tratamiento médico y dilataciones continúan sintomáticos y con tratamiento. De los operados hay uno que ha requerido dilataciones 5 y 9 años después de la intervención, dos que no tuvieron procedimiento anti-reflujo, están en tratamiento por este problema y el resto se encuentran asintomáticos sin que se presentaran complicaciones quirúrgicas.This is a retrospecti ve study of the clinical records of 27 patients diagnosed with achalasia at the Dr. R. A. Calderón Guardia Hospital during a period of eleven years from 1991 to

  1. From Barclay to Calderón: the construction of the gracioso in Argenis and Poliarco

    Directory of Open Access Journals (Sweden)

    Alicia Vara López

    2013-04-01

    Full Text Available Abstract: In 1621 the Argenis of John Barclay is published. A late Latin narrative that achieved a great success. Calderón decided to adapt this renowned story into his comedy Argenis y Poliarco(circa 1627. One of the biggest innovations of the author was the transformation of Poliarco’s gracioso, more suited to the theatrical ways of his time. In this paper we will analyze all the changes that Gelanor experimented from the narrative to the drama in order to become a proper graciosofor the Comedia Nueva.The analysis of all these metamorphoses will provide essential data about the role of this character in the comedy, but also will serve to study the modus scribendi of Calderón.Resumen:En 1621 se publica la Argenis de John Barclay, obra narrativa latina tardía que gozó de un éxito extraordinario en su época. Calderón decide adaptar tan celebrada historia y llevarla a las tablas en su comedia Argenis y Poliarco (circa 1627. Una de las mayores aportaciones del dramaturgo es la transformación del criado de Poliarco, Gelanor, en un gracioso propio de la comedia de su tiempo que se ajusta al marco teatral en el que aparece. En el presente trabajo se analizarán todos los cambios que experimenta Gelanor en su paso desde el molde narrativo al teatral, para convertirse en un prototípico gracioso de la comedia nueva. El examen de toda esta metamorfosis proporcionará claves acerca de la función del personaje en la comedia, pero también servirá para reflexionar acerca del modus scribendi calderoniano.

  2. A note on $H^p_w$-boundedness of Riesz transforms and $\\theta$-Calder\\'on-Zygmund operators through molecular characterization

    CERN Document Server

    Ky, Luong Dang

    2011-01-01

    Let $0 < p \\leq 1$ and $w$ in the Muckenhoupt class $A_1$. Recently, by using the weighted atomic decomposition and molecular characterization; Lee, Lin and Yang \\cite{LLY} (J. Math. Anal. Appl. 301 (2005), 394--400) established that the Riesz transforms $R_j, j=1, 2,...,n$, are bounded on $H^p_w(\\mathbb R^n)$. In this note we extend this to the general case of weight $w$ in the Muckenhoupt class $A_\\infty$ through molecular characterization. One difficulty, which has not been taken care in \\cite{LLY}, consists in passing from atoms to all functions in $H^p_w(\\mathbb R^n)$. Furthermore, the $H^p_w$-boundedness of $\\theta$-Calder\\'on-Zygmund operators are also given through molecular characterization and atomic decomposition.

  3. Proyecto de urbanización "El Calderí" (Mollet del Vallés)

    OpenAIRE

    Justicia Moreno, Raúl

    2011-01-01

    El objetivo de este proyecto es realizar el desarrollo urbanístico (como competencia del ingeniero en edificación) de un sector urbanizable, en este caso, El Calderí. Situado en Mollet del Vallés (Barcelona). Este documento se desarroya a partir de un plan parcial realizado por el ayuntamiento de mollet que organiza la distribución y ordenación de la futura urbanización. El proyecto estará formado por una memoria descriptiva de la obra y se adjuntarán cálculos, planos, medic...

  4. Toeplitz Type Operators Associated with Generalized Calderón-Zygmund Operator on Weighted Morrey Spaces

    Directory of Open Access Journals (Sweden)

    Bijun Ren

    2016-01-01

    Full Text Available Let T1 be a generalized Calderón-Zygmund operator or ±I (the identity operator, let T2 and T4 be the linear operators, and let T3=±I. Denote the Toeplitz type operator by Tb=T1MbIαT2+T3IαMbT4, where Mbf=bf and Iα is the fractional integral operator. In this paper, we investigate the boundedness of the operator Tb on weighted Morrey space when b belongs to the weighted BMO spaces.

  5. El escritor y su paisaje: Eduardo Caballero Calderón

    Directory of Open Access Journals (Sweden)

    Luis González

    2003-01-01

    Full Text Available A Eduardo Caballero Calderón lo vi por primera vez una noche de diciembre de 1974. Recuerdo las paredes blancas de su casa de Teusaquillo, la puerta verde, las vigas de madera al aire en la fachada y el olor ácido de su biblioteca. Pero sobre todo, recuerdo la imagen del viejo calvo, de barba gris, sentado en un sillón de cuero, rodeado por un bastón, un vaso de güisqui aguado y un cenicero lleno de colillas. Porque en esa época, Eduardo todavía fumaba: Pielroja, dos paquetes al día.

  6. La crónica de Ventura García Calderón

    Directory of Open Access Journals (Sweden)

    Esther Espinoza E.

    2012-12-01

    Full Text Available Este estudio brinda una lectura del libro de crónicas Bajo el clamor delas sirenas de Ventura García Calderón, en el que ofrece su visión de labarbarie instalada en el centro de la civilización, mediante la guerra. Lamirada del autor logra extraer de esa experiencia la oportunidad parauniversalizar los valores franceses, capaces de convocar a todos los pueblos y culturas, en una nueva era de avance tecnológico.

  7. The Radon Monitoring System in Daya Bay Reactor Neutrino Experiment

    CERN Document Server

    Chu, M C; Kwok, M W; Kwok, T; Leung, J K C; Leung, K Y; Lin, Y C; Luk, K B; Pun, C S J

    2016-01-01

    We developed a highly sensitive, reliable and portable automatic system (H$^{3}$) to monitor the radon concentration of the underground experimental halls of the Daya Bay Reactor Neutrino Experiment. H$^{3}$ is able to measure radon concentration with a statistical error less than 10\\% in a 1-hour measurement of dehumidified air (R.H. 5\\% at 25$^{\\circ}$C) with radon concentration as low as 50 Bq/m$^{3}$. This is achieved by using a large radon progeny collection chamber, semiconductor $\\alpha$-particle detector with high energy resolution, improved electronics and software. The integrated radon monitoring system is highly customizable to operate in different run modes at scheduled times and can be controlled remotely to sample radon in ambient air or in water from the water pools where the antineutrino detectors are being housed. The radon monitoring system has been running in the three experimental halls of the Daya Bay Reactor Neutrino Experiment since November 2013.

  8. The Cuatrocientos milagros de la cruz of Jaime Bleda: a bedside book for Calderón?

    Directory of Open Access Journals (Sweden)

    Adrián J. Sáez

    2013-04-01

    Full Text Available Abstract:This paper explores the possible knowledge that some authors of the Golden Age may have about certain treatises of historical, philosophical and political nature, besides the well-known relations with other literary works, like the critics frequently have pointed out. So, this investigation compares the series of miracles that appear in La devoción de la cruz of Calderón with the book Cuatrocientos milagros de la cruz of Jaime Bleda, a religious treaty that Calderón might recalled in order to write some passages of this comedy. Overall, this paper reveals data about the prodigious miscellany that may serve to other studies about this matter. Resumen:Este trabajo explora el posible conocimiento que algunos autores del Siglo de Oro pudieron tener de ciertos tratados de tema histórico, filosófico, político, etc., al margen de las relaciones con otras obras literarias, frecuentemente estudiadas por la crítica. Así, se pone en diálogo la serie de milagros que aparecen en La devoción de la cruz de Calderón con los Cuatrocientos milagros de la cruz de Jaime Bleda, un repertorio de milagros que Calderón pudo recordar a la hora de escribir algunos pasajes de esta comedia. Conjuntamente se da noticia de esta miscelánea de prodigios, que puede resultar de gran utilidad para otros estudios.

  9. Más sobre reescritura teatral: El golfo de las sirenas, de Calderón ¿y Funes?

    OpenAIRE

    Urzáiz Tortajada, Héctor

    2002-01-01

    Producción Científica Estudio de una fiesta teatral compuesta por Baltasar de Funes, un oscuro poeta que en esta ocasión utilizó como base una obra mitológica cortesana de Calderón, "El golfo de las sirenas".

  10. Más sobre reescritura teatral: El golfo de las sirenas, de Calderón ¿y Funes?

    OpenAIRE

    Urzáiz Tortajada, Héctor

    2002-01-01

    Producción Científica Estudio de una fiesta teatral compuesta por Baltasar de Funes, un oscuro poeta que en esta ocasión utilizó como base una obra mitológica cortesana de Calderón, "El golfo de las sirenas".

  11. A Calderón multiplicative preconditioner for coupled surface-volume electric field integral equations

    KAUST Repository

    Bagci, Hakan

    2010-08-01

    A well-conditioned coupled set of surface (S) and volume (V) electric field integral equations (S-EFIE and V-EFIE) for analyzing wave interactions with densely discretized composite structures is presented. Whereas the V-EFIE operator is well-posed even when applied to densely discretized volumes, a classically formulated S-EFIE operator is ill-posed when applied to densely discretized surfaces. This renders the discretized coupled S-EFIE and V-EFIE system ill-conditioned, and its iterative solution inefficient or even impossible. The proposed scheme regularizes the coupled set of S-EFIE and V-EFIE using a Calderón multiplicative preconditioner (CMP)-based technique. The resulting scheme enables the efficient analysis of electromagnetic interactions with composite structures containing fine/subwavelength geometric features. Numerical examples demonstrate the efficiency of the proposed scheme. © 2006 IEEE.

  12. Quantum Spin Hall Effect

    Energy Technology Data Exchange (ETDEWEB)

    Bernevig, B.Andrei; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-01-15

    The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. Existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external magnetic field. In this work, we predict a quantized spin Hall effect in the absence of any magnetic field, where the intrinsic spin Hall conductance is quantized in units of 2 e/4{pi}. The degenerate quantum Landau levels are created by the spin-orbit coupling in conventional semiconductors in the presence of a strain gradient. This new state of matter has many profound correlated properties described by a topological field theory.

  13. El camino de la mina, vehículo de emociones en Calderón

    Directory of Open Access Journals (Sweden)

    Rull, Enrique

    2002-12-01

    Full Text Available Calderón uses some scenic devices to stablish certain dramatic situations in the plays. The studied here is related to the function of the mine, which possessed important polisemic values. Not only it is used for stablishing a belie religious or a reat loving environement but also to use this motif with the metaphoric value of passion or as a true laberinto of love, includying trascendental mitological symbols. Everything together is aimed to create a very fast and mysterious activity mixing both comic and tragic effects in which the nonexpected becomes not only dramatical essence but also a personal experience about destinity and life.Calderón utiliza varios recursos escénicos para establecer determinadas situaciones dramáticas en sus obras. El que se estudia aquí se refiere a la función de la mina, que posee valores polisémicos muy notables, los cuales van desde los que le sirven para establecer un ámbito guerrero, religioso, amoroso de carácter real, hasta la utilización de este motivo con carácter metafórico de la pasión amorosa o como verdadero laberinto de amor que incluye incluso una mitologización trascendente de la misma. Todo ello le sirve para configurar en sus obras una acción trepidante, misteriosa, en la que se mezcla lo cómico con lo trágico, y en donde lo inesperado cobra un valor no sólo de esencia dramática sino también de vivencia existencial acerca del destino de la vida.

  14. Skyrmions and Hall Transport

    Science.gov (United States)

    Kim, Bom Soo; Shapere, Alfred D.

    2016-09-01

    We derive a generalized set of Ward identities that captures the effects of topological charge on Hall transport. The Ward identities follow from the (2 +1 )-dimensional momentum algebra, which includes a central extension proportional to the topological charge density. In the presence of topological objects like Skyrmions, we observe that the central term leads to a direct relation between the thermal Hall conductivity and the topological charge density. We extend this relation to incorporate the effects of a magnetic field and an electric current. The topological charge density produces a distinct signature in the electric Hall conductivity, which is identified in existing experimental data and yields further novel predictions. For insulating materials with translation invariance, the Hall viscosity can be directly determined from the Skyrmion density and the thermal Hall conductivity to be measured as a function of momentum.

  15. El motivo del viaje en los autos sacramentales de Calderón, I: los viajes mitológicos

    Directory of Open Access Journals (Sweden)

    Arellano, Ignacio

    2011-06-01

    Full Text Available The article examines the aspects of the travel in five allegorical plays of Calderón with mythological argument, analyzing the main elements of travel narrative and allegorical use in relation with conventions of the sacramental plays. Especially important is the structure of travel in El divino Jasón and Los encantos de la Culpa organized on the story of the Argonauts and the Odyssey respectively.El artículo examina los aspectos del viaje en cinco autos de argumento mitológico de Calderón, analizando los principales elementos de relato de viaje y su utilización alegórica en el marco del género sacramental. Destaca por su importancia la estructura del viaje en los autos El divino Jasón y Los encantos de la Culpa, sobre la historia de los argonautas y la Odisea respectivamente.

  16. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  17. Sarcoidosis: experiencia con 15 casos en el Hospital Calderón Guardia

    Directory of Open Access Journals (Sweden)

    José Mainieri-Hidalgo

    2002-06-01

    Full Text Available La sarcoidosis es una enfermedad que se diagnostica con poca frecuencia en Costa Rica; en 1988 fueron informados 6 casos en el Hospital San Juan de Dios. En este estudio se da cuenta de las características clínicas y el manejo de 15 pacientes del Hospital Calderón Guardia, diagnosticados entre 1987 y 2001. Todos los casos fueron de localización torácica y en doce de ellos la enfermedad afectó solamente los ganglios del mediastino, por lo que la radiografía de tórax fue el método de detección . Los síntomas más frecuentes fueron tos y disnea. La mediastinoscopía fue el método más utilizado para obtener la biopsia. El diagnóstico histológico se hizo por el hallazgo de granulomas no necrotizantes, infiltrado linfocitario y la presencia de células gigantes, sin que se aislara ningún germen. Catorce pacientes recibieron tratamiento sintomático y observación y solo uno presentó afección pulmonar y sintomatología respiratoria y recibió esteroides. El paciente con enfermedad pulmonar sintomática continúa con esteroides y los pacientes observados, por un promedio de 7 años, evolucionaron a resolución espontánea sin producirse recidivas.Sarcoidosis is an infrequent disease in Costa Rica. In 1988 the Hospital San Juan de Dios reported six cases. This is a clinical study of 15 patients diagnosed at the Hospital Calderón Guardia from 1987 to 2001. All the patients presented with thoracic disease and in 12 of them it was localized to the mediastinal lymph nodes. A chest X-ray detected all the cases; cough and dispnea were the most frequent symptoms and mediastinoscopy was the most useful method to obtain a biopsy. The histologic diagnosis was made in the presence of non-necrotizing granulomas, giant cells and a lymphocytic infiltrate. No microorganisms were isolated. Fourteen patients received symptomatic treatment and observation, and one with pulmonary disease and respiratory symptoms received also steroids. All the patients

  18. Halls Lake 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salt marsh habitats along the shoreline of Halls Lake are threatened by wave erosion, but the reconstruction of barrier islands to reduce this erosion will modify or...

  19. General footage ISOLDE experimental hall

    CERN Multimedia

    2016-01-01

    Overview of the ISOLDE experimental hall. Equipment and experiments. Taken from the WITCH / EBIS platform: ISOLDE hall infrastructure, GHM line, LA1, LA2, LA0, central beamline, COLLAPS experiment, CRIS experiment, ISOLTRAP experiment, laser guidance from building 508 into the hall for laser spectroscopy COLLAPS and CRIS. Taken from the HIE ISOLDE shielding tunnel roof: ISOLDE hall infrastructure, WITCH experiment, VITO line, TAS experiment. General footage: High Tension room entrance and EBIS platform, staircases and passages in the experimental hall.

  20. Phonon-Mediated KIDs as Light Detectors for Rare-Event Search: The CALDER Project

    Science.gov (United States)

    Cruciani, A.; Bellini, F.; Cardani, L.; Casali, N.; Castellano, M. G.; Colantoni, I.; Coppolecchia, A.; Cosmelli, C.; D'Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.; Vignati, M.

    2016-08-01

    Background suppression plays a crucial role in experiments searching for rare events, like neutrino-less double beta decay (0ν DBD) and dark matter. Large mass bolometers that are among the most competitive devices in this field would largely benefit from the development of ultrasensitive light detectors, as the combined readout of the bolometric and light signals enables the particle identification. The CALDER collaboration is developing cryogenic light detectors that will match the requirements of next generation experiments: noise lower than 20 eV RMS, large active area (several cm2), wide temperature range of operation, and ease in fabricating and operating a thousand of detectors. For this purpose, we are exploiting the excellent energy resolution and the natural multiplexed read-out provided by kinetic inductance detectors (KIDs). These devices can be operated in a phonon-mediated approach, in which KIDs are coupled to a large insulating substrate in order to increase the active surface from a few mm2 to 25 cm2. Our current best prototype, based on aluminum LEKIDs, reached a baseline sensitivity of 80 eV with an overall efficiency of about 20 %.

  1. Nonlocal Anomalous Hall Effect

    Science.gov (United States)

    Zhang, Steven S.-L.; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect—the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt /YIG structures.

  2. Conducting Wall Hall Thrusters

    Science.gov (United States)

    Goebel, Dan M.; Hofer, Richard R.; Mikellides, Ioannis G.; Katz, Ira; Polk, James E.; Dotson, Brandon

    2013-01-01

    A unique configuration of the magnetic field near the wall of Hall thrusters, called Magnetic Shielding, has recently demonstrated the ability to significantly reduce the erosion of the boron nitride (BN) walls and extend the life of Hall thrusters by orders of magnitude. The ability of magnetic shielding to minimize interactions between the plasma and the discharge chamber walls has for the first time enabled the replacement of insulating walls with conducting materials without loss in thruster performance. The boron nitride rings in the 6 kW H6 Hall thruster were replaced with graphite that self-biased to near the anode potential. The thruster efficiency remained over 60% (within two percent of the baseline BN configuration) with a small decrease in thrust and increase in Isp typical of magnetically shielded Hall thrusters. The graphite wall temperatures decreased significantly compared to both shielded and unshielded BN configurations, leading to the potential for higher power operation. Eliminating ceramic walls makes it simpler and less expensive to fabricate a thruster to survive launch loads, and the graphite discharge chamber radiates more efficiently which increases the power capability of the thruster compared to conventional Hall thruster designs.

  3. Nonlocal Anomalous Hall Effect.

    Science.gov (United States)

    Zhang, Steven S-L; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect-the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt/YIG structures.

  4. Sarcoidosis: experiencia con 15 casos en el Hospital Calderón Guardia

    Directory of Open Access Journals (Sweden)

    José Mainieri-Hidalgo

    2002-06-01

    Full Text Available La sarcoidosis es una enfermedad que se diagnostica con poca frecuencia en Costa Rica; en 1988 fueron informados 6 casos en el Hospital San Juan de Dios. En este estudio se da cuenta de las características clínicas y el manejo de 15 pacientes del Hospital Calderón Guardia, diagnosticados entre 1987 y 2001. Todos los casos fueron de localización torácica y en doce de ellos la enfermedad afectó solamente los ganglios del mediastino, por lo que la radiografía de tórax fue el método de detección . Los síntomas más frecuentes fueron tos y disnea. La mediastinoscopía fue el método más utilizado para obtener la biopsia. El diagnóstico histológico se hizo por el hallazgo de granulomas no necrotizantes, infiltrado linfocitario y la presencia de células gigantes, sin que se aislara ningún germen. Catorce pacientes recibieron tratamiento sintomático y observación y solo uno presentó afección pulmonar y sintomatología respiratoria y recibió esteroides. El paciente con enfermedad pulmonar sintomática continúa con esteroides y los pacientes observados, por un promedio de 7 años, evolucionaron a resolución espontánea sin producirse recidivas.

  5. Representation of the Indian in Calderón’s «La Aurora en Copacabana»

    Directory of Open Access Journals (Sweden)

    José Elías Gutiérrez Meza

    2014-11-01

    Full Text Available The article analyzes the onomastics of the Indian characters, the portrayal of the Inca Empire of Huáscar and Atahualpa, and the Christianization of Guacolda and Yupangui in Calderón’s La Aurora en Copacabana. Rational and proactive, these two characters realize the illegitimacy of the Inca idolatry and embrace the true religion, long before the formal start of Perú’s christianization. Thus, it is argued that this specific representation of the Indian may have been influenced by the close circles indianos of Miguel de Aguirre, who allegedly patronized this comedy.

  6. Representation of the Indian in Calderón’s «La Aurora en Copacabana»

    OpenAIRE

    José Elías Gutiérrez Meza

    2014-01-01

    The article analyzes the onomastics of the Indian characters, the portrayal of the Inca Empire of Huáscar and Atahualpa, and the Christianization of Guacolda and Yupangui in Calderón’s La Aurora en Copacabana. Rational and proactive, these two characters realize the illegitimacy of the Inca idolatry and embrace the true religion, long before the formal start of Perú’s christianization. Thus, it is argued that this specific representation of the Indian may have been influenced by the close cir...

  7. Pedro Calderón de la Barca, Autos sacramentales - Francisco de Quevedo, Prosa satírica

    Directory of Open Access Journals (Sweden)

    Fernando Plata

    2012-12-01

    Full Text Available Reviews of Pedro Calderón de la Barca, Autos sacramentales. El divino Jasón. El gran mercado del Mundo. El gran teatro del Mundo. La viña del Señor, ed. I. Arellano, Homo Legens (Bibliotheca Homolegens, 50, Madrid, 2010, 406 pp. ISBN: 978-84-92518-54-8 y Francisco de Quevedo, Prosa satírica, ed. I. Arellano, Homo Legens (Bibliotheca Homolegens, 58, Madrid, 2011, 206 pp. ISBN: 978-84-92518-69-2.

  8. Hall Effect in Quasicrystals

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiang; HU Cheng-zheng; GONG Ping; WANG Ai-jun

    2005-01-01

    The relations between Hall effect and symmetry are discussed for all 2- and 3 dimensional quasicrystals with crystallographically forbidden symmetries. The results show that the numbers of independent components of the Hall coefficient (RH) are one for 3-dimensional quasicrystals, two for those 2 dimensional quasicrystals whose symmetry group is non-Abelian, and three for those 2-dimensional quasicrystals whose symmetry group is Abelian, respectively. The quasicrystals with the same number of independent components have the same form of the components of RH.

  9. Hall effect in hopping regime

    Energy Technology Data Exchange (ETDEWEB)

    Avdonin, A., E-mail: avdonin@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Skupiński, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Grasza, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Institute of Electronic Materials Technology, ul. Wólczyńska 133, 01-919 Warszawa (Poland)

    2016-02-15

    A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO. - Highlights: • Expressions for Hall coefficient and mobility for hopping conductivity are derived. • Theoretical result is compared with experimental curves measured on ZnO. • Simultaneous action of free and hopping conduction channels is considered. • Non-linearity of hopping Hall coefficient is predicted.

  10. Hall Effect in a Plasma.

    Science.gov (United States)

    Kunkel, W. B.

    1981-01-01

    Describes an apparatus and procedure for conducting an undergraduate laboratory experiment to quantitatively study the Hall effect in a plasma. Includes background information on the Hall effect and rationale for conducting the experiment. (JN)

  11. Laurance David Hall.

    Science.gov (United States)

    Coxon, Bruce

    2011-01-01

    An account is given of the life, scientific contributions, and passing of Laurance David Hall (1938-2009), including his early history and education at the University of Bristol, UK, and the synthesis and NMR spectroscopy of carbohydrates and other natural products during ∼20 years of research and teaching at the University of British Columbia in Vancouver, Canada. Lists of graduate students, post-doctoral fellows, and sabbatical visitors are provided for this period. Following a generous endowment by Dr. Herchel Smith, Professor Hall built a new Department of Medicinal Chemistry at Cambridge University, UK, and greatly expanded his researches into the technology and applications of magnetic resonance imaging (MRI) and zero quantum NMR. MRI technology was applied both to medical problems such as the characterization of cartilage degeneration in knee joints, the measurement of ventricular function, lipid localization in animal models of atherosclerosis, paramagnetic metal complexes of polysaccharides as contrast agents, and studies of many other anatomical features, but also to several aspects of materials analysis, including food analyses, process control, and the elucidation of such physical phenomena as the flow of liquids through porous media, defects in concrete, and the visualization of fungal damage to wood. Professor Hall's many publications, patents, lectures, and honors and awards are described, and also his successful effort to keep the Asilomar facility in Pacific Grove, California as the alternating venue for the annual Experimental NMR Conference. Two memorial services for Professor Hall are remembered.

  12. Strained graphene Hall bar

    Science.gov (United States)

    Milovanović, S. P.; Peeters, F. M.

    2017-02-01

    The effects of strain, induced by a Gaussian bump, on the magnetic field dependent transport properties of a graphene Hall bar are investigated. The numerical simulations are performed using both classical and quantum mechanical transport theory and we found that both approaches exhibit similar characteristic features. The effects of the Gaussian bump are manifested by a decrease of the bend resistance, R B, around zero-magnetic field and the occurrence of side-peaks in R B. These features are explained as a consequence of bump-assisted scattering of electrons towards different terminals of the Hall bar. Using these features we are able to give an estimate of the size of the bump. Additional oscillations in R B are found in the quantum description that are due to the population/depopulation of Landau levels. The bump has a minor influence on the Hall resistance even for very high values of the pseudo-magnetic field. When the bump is placed outside the center of the Hall bar valley polarized electrons can be collected in the leads.

  13. The Inhomogeneous Hall's Ray

    OpenAIRE

    Crisp, D J; W Moran; Pollington, A. D.

    2012-01-01

    We show that the inhomogenous approximation spectrum, associated to an irrational number \\alpha\\ always has a Hall's Ray; that is, there is an \\epsilon>0 such that [0,\\epsilon) is a subset of the spectrum. In the case when \\alpha\\ has unbounded partial quotients we show that the spectrum is just a ray.

  14. Hall Sweet Home

    Science.gov (United States)

    Oguntoyinbo, Lekan

    2011-01-01

    Many urban and commuter universities have their sights set on students who are unlikely to connect with the college and likely to fail unless the right strategies are put in place to help them graduate. In efforts to improve retention rates, commuter colleges are looking to an unusual suspect: residence halls. The author discusses how these…

  15. Photon thermal Hall effect

    CERN Document Server

    Ben-Abdallah, Philippe

    2015-01-01

    A near-field thermal Hall effect (i.e.Righi-Leduc effect) in lattices of magneto-optical particles placed in a constant magnetic field is predicted. This effect is related to a symetry breaking in the system induced by the magnetic field which gives rise to preferential channels for the heat-transport by photon tunneling thanks to the particles anisotropy tuning.

  16. The Monty Hall Dilemma

    NARCIS (Netherlands)

    Barteld Kooi, [No Value

    2006-01-01

    Samenvatting: In het begin van de jaren negentig brak een wereldwijde discussie los over een probleem dat in het Engels 'The Monty Hall Dilemma' wordt genoemd. Marilyn vos Savant, die in het Guinness Book of World Records wordt genoemd als degene met het

  17. Plasma Relaxation in Hall Magnetohydrodynamics

    CERN Document Server

    Shivamoggi, B K

    2011-01-01

    Parker's formulation of isotopological plasma relaxation process in magnetohydrodynamics (MHD) is extended to Hall MHD. The torsion coefficient alpha in the Hall MHD Beltrami condition turns out now to be proportional to the "potential vorticity." The Hall MHD Beltrami condition becomes equivalent to the "potential vorticity" conservation equation in two-dimensional hydrodynamics if the Hall MHD Lagrange multiplier beta is taken to be proportional to the "potential vorticity" as well. The winding pattern of the magnetic field lines in Hall MHD then appears to evolve in the same way as "potential vorticity" lines in 2D hydrodynamics.

  18. Stability of the Hall sensors performance under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I.; Hron, M.; Stockel, J. [Institute of Plasma Physics, Association EURATOM/IPP.CR, Praha (Czech Republic); Viererbl, L.; Vsolak, R.; Cerva, V. [Nuclear Research Institute plc (Czech Republic); Bolshakova, I.; Holyaka, R. [Lviv Polytechnic National Univ. (Ukraine); Vayakis, G. [ITER International Team, Naka Joint Work Site, Naka, Ibaraki (Japan)

    2004-07-01

    A principally new diagnostic method must be developed for magnetic measurements in steady state regime of operation of fusion reactor. One of the options is the use of transducers based on Hall effect. The use of Hall sensors in ITER is presently limited by their questionable radiation and thermal stability. Issues of reliable operation in ITER like radiation and thermal environment are addressed in the paper. The results of irradiation tests of candidate Hall sensors in LVR-15 and IBR-2 experimental fission reactors are presented. Stable operation (deterioration of sensitivity below one percent) of the specially prepared sensors was demonstrated during irradiation by the total fluence of 3.10{sup 16} n/cm{sup 2} in IBR-2 reactor. Increasing the total neutron fluence up to 3.10{sup 17} n/cm{sup 2} resulted in deterioration of the best sensor's output still below 10% as demonstrated during irradiation in LVR-15 fission reactor. This level of neutron is already higher than the expected ITER life time neutron fluence for a sensor location just outside the ITER vessel. (authors)

  19. Cylindrical geometry hall thruster

    Science.gov (United States)

    Raitses, Yevgeny; Fisch, Nathaniel J.

    2002-01-01

    An apparatus and method for thrusting plasma, utilizing a Hall thruster with a cylindrical geometry, wherein ions are accelerated in substantially the axial direction. The apparatus is suitable for operation at low power. It employs small size thruster components, including a ceramic channel, with the center pole piece of the conventional annular design thruster eliminated or greatly reduced. Efficient operation is accomplished through magnetic fields with a substantial radial component. The propellant gas is ionized at an optimal location in the thruster. A further improvement is accomplished by segmented electrodes, which produce localized voltage drops within the thruster at optimally prescribed locations. The apparatus differs from a conventional Hall thruster, which has an annular geometry, not well suited to scaling to small size, because the small size for an annular design has a great deal of surface area relative to the volume.

  20. Relativistic Hall Effect

    CERN Document Server

    Bliokh, Konstantin Y

    2011-01-01

    We consider the relativistic deformation of quantum waves and mechanical bodies carrying intrinsic angular momentum (AM). When observed in a moving reference frame, the centroid of the object undergoes an AM-dependent transverse shift. This is the relativistic analogue of the spin Hall effect, which occurs in free space without any external fields. Remarkably, the shifts of the geometric and energy centroids differ by a factor of 2, and both centroids are crucial for the correct Lorentz transformations of the AM tensor. We examine manifestations of the relativistic Hall effect in quantum vortices, mechanical flywheel, and discuss various fundamental aspects of the phenomenon. The perfect agreement of quantum and relativistic approaches allows applications at strikingly different scales: from elementary spinning particles, through classical light, to rotating black-holes.

  1. Planar Hall Effect MRAM

    OpenAIRE

    Bason, Y.; Klein, L.; Yau, J. -B.; Hong, X.; Hoffman, J.; Ahn, C. H.

    2005-01-01

    We suggest a new type of magnetic random access memory (MRAM) that is based on the phenomenon of the planar Hall effect (PHE) in magnetic films, and we demonstrate this idea with manganite films. The PHE-MRAM is structurally simpler than currently developed MRAM that is based on magnetoresistance tunnel junctions (MTJ), with the tunnel junction structure being replaced by a single layer film.

  2. Annual report on JEN-1 reactor; Informe periodico del Reactor JEN-1 correspondiente al ano 1971

    Energy Technology Data Exchange (ETDEWEB)

    Montes, J.

    1972-07-01

    In the annual report on the JEN-1 reactor the main features of the reactor operations and maintenance are described. The reactor has been critical for 1831 hours, what means 65,8% of the total working time. Maintenance and pool water contamination have occupied the rest of the time. The maintenance schedule is shown in detail according to three subjects. The main failures and reactor scrams are also described. The daily maximum values of the water activity are given so as the activity of the air in the reactor hall. (Author)

  3. Bronquiectasias, estudio de 36 pacientes intervenidos en el hospital “Dr. Rafael Ángel Calderón Guardia”

    Directory of Open Access Journals (Sweden)

    José Alberto Mainieri-Hidalgo

    2011-09-01

    Full Text Available Objetivo: Analizar el resultado de la cirugía por bronquiectasias en el Servicio de Cirugía de Tórax del Hospital Calderón Guardia. Método: Se revisaron los expedientes clínicos de 36 pacientes operados, con un total de 44 intervenciones por bronquiectasias. Resultados: Se encontró una prevalencia muy significativa de la enfermedad en mujeres, con una relación de 11 a 1. La etiología fue en 10 casos el antecedente de tuberculosis, en uno el síndrome de Kartagener, y en 25 no se logró establecer. Todos los pacientes tenían antecedente de tos y expectoración mucopurulenta de larga evolución, y 29 habían sido clasificados como asmáticos, aunque 10 no tenían ningún antecedente familiar. La radiografía de tórax fue anormal en todos los casos, mostrando áreas de fibrosis, infiltrados o nódulos, pero no fue útil para establecer el diagnóstico de bronquiectasias, contrario a la TAC, que en todos mostró las lesiones bronquiales. El resultado de la cirugía, contrario a lo esperado, no logró establecer un indicador de éxito, pues pacientes con lesiones muy localizadas continuaron expectorando e infectándose, y otros con patología difusa y bilateral, mejoraron sustancialmente. Conclusiones: La cirugía por bronquiectasias está indicada cuando el tratamiento médico no logra controlar satisfactoriamente los cuadros infecciosos bronquiales. Existe franca posibilidad de mejoría, pero no un indicador de éxito para el procedimiento quirúrgico.

  4. "Hall viscosity" and intrinsic metric of incompressible fractional Hall fluids

    OpenAIRE

    Haldane, F. D. M.

    2009-01-01

    The (guiding-center) "Hall viscosity" is a fundamental tensor property of incompressible ``Hall fluids'' exhibiting the fractional quantum Hall effect; it determines the stress induced by a non-uniform electric field, and the intrinsic dipole moment on (unreconstructed) edges. It is characterized by a rational number and an intrinsic metric tensor that defines distances on an ``incompressibility lengthscale''. These properties do not require rotational invariance in the 2D plane. The sign of ...

  5. Irradiation tests of ITER candidate Hall sensors using two types of neutron spectra.

    Science.gov (United States)

    Ďuran, I; Bolshakova, I; Viererbl, L; Sentkerestiová, J; Holyaka, R; Lahodová, Z; Bém, P

    2010-10-01

    We report on irradiation tests of InSb based Hall sensors at two irradiation facilities with two distinct types of neutron spectra. One was a fission reactor neutron spectrum with a significant presence of thermal neutrons, while another one was purely fast neutron field. Total neutron fluence of the order of 10(16) cm(-2) was accumulated in both cases, leading to significant drop of Hall sensor sensitivity in case of fission reactor spectrum, while stable performance was observed at purely fast neutron spectrum. This finding suggests that performance of this particular type of Hall sensors is governed dominantly by transmutation. Additionally, it further stresses the need to test ITER candidate Hall sensors under neutron flux with ITER relevant spectrum.

  6. Wheel of concert hall acoustics

    OpenAIRE

    Kuusinen, A.; Lokki, T.

    2017-01-01

    More than a hundred years of research on concert hall acoustics has provided an extensive list of attributes to describe and evaluate the perceptual aspects of sound in concert halls. This brief overview discusses the current knowledge, and presents a "wheel of concert hall acoustics" in which the main aspects are gathered together with the descriptive attributes that are commonly encountered in the research literature. Peer reviewed

  7. Thermal Hall Effect of Magnons

    Science.gov (United States)

    Murakami, Shuichi; Okamoto, Akihiro

    2017-01-01

    We review recent developments in theories and experiments on the magnon Hall effect. We derive the thermal Hall conductivity of magnons in terms of the Berry curvature of magnonic bands. In addition to the Dzyaloshinskii-Moriya interaction, we show that the dipolar interaction can make the Berry curvature nonzero. We mainly discuss theoretical aspects of the magnon Hall effect and related theoretical works. Experimental progress in this field is also mentioned.

  8. A calderón-preconditioned single source combined field integral equation for analyzing scattering from homogeneous penetrable objects

    KAUST Repository

    Valdés, Felipe

    2011-06-01

    A new regularized single source equation for analyzing scattering from homogeneous penetrable objects is presented. The proposed equation is a linear combination of a Calderón-preconditioned single source electric field integral equation and a single source magnetic field integral equation. The equation is immune to low-frequency and dense-mesh breakdown, and free from spurious resonances. Unlike dual source formulations, this equation involves operator products that cannot be discretized using standard procedures for discretizing standalone electric, magnetic, and combined field operators. Instead, the single source equation proposed here is discretized using a recently developed technique that achieves a well-conditioned mapping from div- to curl-conforming function spaces, thereby fully respecting the space mapping properties of the operators involved, and guaranteeing accuracy and stability. Numerical results show that the proposed equation and discretization technique give rise to rapidly convergent solutions. They also validate the equation\\'s resonant free character. © 2006 IEEE.

  9. Non-Euclidean Space, Movement and Astronomy in Modern Art: Alexander Calder's Mobiles and Ben Nicholson's Reliefs

    Science.gov (United States)

    Malloy, Vanja

    2013-09-01

    John Keats once wrote that `there is no such thing as time and space' rather, believing that time and space are mental constructs that are subject to a variety of forms and as diverse as the human mind. In the 1920s through the 1930s, modern physics in many ways supported this idea through the various philosophical writings on the Theory of General Relativity to the masses by scientists such as Arthur Eddington and Albert Einstein. These new concepts of modern physics fundamentally changed our understanding of time and space and had substantial philosophical implications, which were absorbed by modern artists resulting in the 1936 Dimensionist Manifesto. Seeking to internalize the developments of modern science within modern art, this manifesto was widely endorsed by the most prominent figures of the avant-garde such as Marcel Duchamp, Jean Arp, Naum Gabo, Joan Miró, László Moholy-Nagy, Wassily Kandinsky and Alexander Calder. Of particular interest to this manifesto was the new concept of the fourth-dimension, which in many ways revolutionized the arts. Importantly, its interpretation varied widely in the artistic community, ranging from a purely physical four-dimensional space, to a kinetic concept of space in which space and time are linked, to a metaphysical interest in a space that exists beyond the material realm. The impact of modern science and astronomy on avant-garde art is currently a bourgeoning area of research with considerable implications to our rethinking of substantial artistic figures of this era. Through a case study of Alexander Calder's Mobiles and Ben Nicholson's Reliefs, this paper explores how these artworks were informed by an interest in modern science.

  10. Magnesium Hall Thruster

    Science.gov (United States)

    Szabo, James J.

    2015-01-01

    This Phase II project is developing a magnesium (Mg) Hall effect thruster system that would open the door for in situ resource utilization (ISRU)-based solar system exploration. Magnesium is light and easy to ionize. For a Mars- Earth transfer, the propellant mass savings with respect to a xenon Hall effect thruster (HET) system are enormous. Magnesium also can be combusted in a rocket with carbon dioxide (CO2) or water (H2O), enabling a multimode propulsion system with propellant sharing and ISRU. In the near term, CO2 and H2O would be collected in situ on Mars or the moon. In the far term, Mg itself would be collected from Martian and lunar regolith. In Phase I, an integrated, medium-power (1- to 3-kW) Mg HET system was developed and tested. Controlled, steady operation at constant voltage and power was demonstrated. Preliminary measurements indicate a specific impulse (Isp) greater than 4,000 s was achieved at a discharge potential of 400 V. The feasibility of delivering fluidized Mg powder to a medium- or high-power thruster also was demonstrated. Phase II of the project evaluated the performance of an integrated, highpower Mg Hall thruster system in a relevant space environment. Researchers improved the medium power thruster system and characterized it in detail. Researchers also designed and built a high-power (8- to 20-kW) Mg HET. A fluidized powder feed system supporting the high-power thruster was built and delivered to Busek Company, Inc.

  11. Hall Effect Spintronics

    Science.gov (United States)

    2008-09-23

    in Fig. 1. An alternating current source operating at frequency f1 is attached to contacts B and D with a respective lock-in amplifier monitoring...that floats the signal and a transconductance amplifier . The input voltage of each lock-in amplifier is composed of two signals: the Hall voltage at...alternating current sources operating at frequencies f1 and f2 respectively. VAC and VDB are lock-in amplifiers set for the reference frequencies f2 and f1

  12. The Microwave Hall Effect

    OpenAIRE

    2015-01-01

    This paper describes a simple microwave apparatus to measure the Hall effect in semiconductor wafers. The advantage of this technique is that it does not require contacts on the sample or the use of a resonant cavity. Our method consists of placing the semiconductor wafer into a slot cut in an X-band (8 - 12 GHz) waveguide series tee, injecting microwave power into the two opposite arms of the tee, and measuring the microwave output at the third arm. A magnetic field applied perpendicular to ...

  13. H Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The H Reactor was the first reactor to be built at Hanford after World War II.It became operational in October of 1949, and represented the fourth nuclear reactor on...

  14. The ISOLDE hall

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Since 1992, after its move from the 600 MeV SC, ISOLDE is a customer of the Booster (then 1 GeV, now 1.4 GeV). The intense Booster beam (some 3E13 protons per pulse) is directed onto a target, from which a mixture of isotopes emanates. After ionization and electrostatic acceleration to 60 keV, they enter one of the 2 spectrometers (General Purpose Separator: GPS, and High Resolution Separator: HRS) from which the selected ions are directed to the experiments. The photos show: the REX-ISOLDE post accelerator; the mini-ball experiment; an overview of the ISOLDE hall. In the picture (_12) of the hall, the separators are behind the wall. From either of them, beams can be directed into any of the many beamlines towards the experiments, some of which are visible in the foreground. The elevated cubicle at the left is EBIS (Electron Beam Ion Source), which acts as a charge-state multiplier for the REX facility. The ions are further mass analzyzed and passed on to the linac which accelerates them to higher energies. T...

  15. Cosmopolitanism - Conversation with Stuart Hall

    OpenAIRE

    Hall, Stuart

    2006-01-01

    Forty minute conversation between Stuart Hall and Pnina Werbner, filmed and edited by Haim Bresheeth. Synopsis by Sarah Harrison. Conversation between Stuart Hall and Pnina Werbner on the theme of Cosmopolitanism (to be shown at the Association of Social Anthropologists Silver Jubilee conference in 2006), in March 2006

  16. "Calderón en el Romea", taller interdisciplinar para Educación Secundaria: la experiencia pedagógica

    OpenAIRE

    Caro Valverde, María Teresa; Gea Martínez, Fernando; Sánchez Mateos, Ana Rosa

    2008-01-01

    Trabajo descriptivo y reflexivo del proceso didáctico interdisciplinar y del valor pedagógico humanista de la experiencia de innovación educativa que dio lugar a la publicación "Calderón en el Romea", obra que recibió varios premios nacionales por parte de Santillana, y de la que fueron coordinadores los autores de este documento.

  17. Hall Effect Gyrators and Circulators

    Science.gov (United States)

    Viola, Giovanni; DiVincenzo, David P.

    2014-04-01

    The electronic circulator and its close relative the gyrator are invaluable tools for noise management and signal routing in the current generation of low-temperature microwave systems for the implementation of new quantum technologies. The current implementation of these devices using the Faraday effect is satisfactory but requires a bulky structure whose physical dimension is close to the microwave wavelength employed. The Hall effect is an alternative nonreciprocal effect that can also be used to produce desired device functionality. We review earlier efforts to use an Ohmically contacted four-terminal Hall bar, explaining why this approach leads to unacceptably high device loss. We find that capacitive coupling to such a Hall conductor has much greater promise for achieving good circulator and gyrator functionality. We formulate a classical Ohm-Hall analysis for calculating the properties of such a device, and show how this classical theory simplifies remarkably in the limiting case of the Hall angle approaching 90°. In this limit, we find that either a four-terminal or a three-terminal capacitive device can give excellent circulator behavior, with device dimensions far smaller than the ac wavelength. An experiment is proposed to achieve GHz-band gyration in millimeter (and smaller) scale structures employing either semiconductor heterostructure or graphene Hall conductors. An inductively coupled scheme for realizing a Hall gyrator is also analyzed.

  18. Topological Hall and spin Hall effects in disordered skyrmionic textures

    KAUST Repository

    Ndiaye, Papa Birame

    2017-02-24

    We carry out a thorough study of the topological Hall and topological spin Hall effects in disordered skyrmionic systems: the dimensionless (spin) Hall angles are evaluated across the energy-band structure in the multiprobe Landauer-Büttiker formalism and their link to the effective magnetic field emerging from the real-space topology of the spin texture is highlighted. We discuss these results for an optimal skyrmion size and for various sizes of the sample and find that the adiabatic approximation still holds for large skyrmions as well as for nanoskyrmions. Finally, we test the robustness of the topological signals against disorder strength and show that the topological Hall effect is highly sensitive to momentum scattering.

  19. Tuning giant anomalous Hall resistance ratio in perpendicular Hall balance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. Y.; Yang, G. [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, S. G., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, J. L. [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Wang, R. M. [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Amsellem, E.; Kohn, A. [Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Yu, G. H., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-04-13

    Anomalous Hall effect at room temperature in perpendicular Hall balance with a core structure of [Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4} has been tuned by functional CoO layers, where [Pt/Co]{sub 4} multilayers exhibit perpendicular magnetic anisotropy. A giant Hall resistance ratio up to 69 900% and saturation Hall resistance (R{sub S}{sup P}) up to 2590 mΩ were obtained in CoO/[Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4}/CoO system, which is 302% and 146% larger than that in the structure without CoO layers, respectively. Transmission electron microscopy shows highly textured [Co/Pt]{sub 4} multilayers and oxide layers with local epitaxial relations, indicating that the crystallographic structure has significant influence on spin dependent transport properties.

  20. City and Town Halls; townHalls13

    Data.gov (United States)

    University of Rhode Island Geospatial Extension Program — Locations of city and town halls in Rhode Island. Derived using information originally compiled by the State of Rhode Island (http://www.ri.gov), and built upon...

  1. Ward Identities for Hall Transport

    CERN Document Server

    Hoyos, Carlos; Oz, Yaron

    2014-01-01

    We derive quantum field theory Ward identities based on linear area preserving and conformal transformations in 2+1 dimensions. The identities relate Hall viscosities, Hall conductivities and the angular momentum. They apply both for relativistic and non relativistic systems, at zero and at finite temperature. We consider systems with or without translation invariance, and introduce an external magnetic field and viscous drag terms. A special case of the identities yields the well known relation between the Hall conductivity and half the angular momentum density.

  2. Planar Hall effect bridge magnetic field sensors

    DEFF Research Database (Denmark)

    Henriksen, A.D.; Dalslet, Bjarke Thomas; Skieller, D.H.

    2010-01-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can...... Hall effect bridge sensors....

  3. Bronquiectasias, estudio de 36 pacientes intervenidos en el hospital “Dr. Rafael Ángel Calderón Guardia” Bronchiectasis, Results of Surgical Intervention in 36 Patients

    Directory of Open Access Journals (Sweden)

    José Alberto Mainieri-Hidalgo

    2011-09-01

    Full Text Available Objetivo: Analizar el resultado de la cirugía por bronquiectasias en el Servicio de Cirugía de Tórax del Hospital Calderón Guardia. Método: Se revisaron los expedientes clínicos de 36 pacientes operados, con un total de 44 intervenciones por bronquiectasias. Resultados: Se encontró una prevalencia muy significativa de la enfermedad en mujeres, con una relación de 11 a 1. La etiología fue en 10 casos el antecedente de tuberculosis, en uno el síndrome de Kartagener, y en 25 no se logró establecer. Todos los pacientes tenían antecedente de tos y expectoración mucopurulenta de larga evolución, y 29 habían sido clasificados como asmáticos, aunque 10 no tenían ningún antecedente familiar. La radiografía de tórax fue anormal en todos los casos, mostrando áreas de fibrosis, infiltrados o nódulos, pero no fue útil para establecer el diagnóstico de bronquiectasias, contrario a la TAC, que en todos mostró las lesiones bronquiales. El resultado de la cirugía, contrario a lo esperado, no logró establecer un indicador de éxito, pues pacientes con lesiones muy localizadas continuaron expectorando e infectándose, y otros con patología difusa y bilateral, mejoraron sustancialmente. Conclusiones: La cirugía por bronquiectasias está indicada cuando el tratamiento médico no logra controlar satisfactoriamente los cuadros infecciosos bronquiales. Existe franca posibilidad de mejoría, pero no un indicador de éxito para el procedimiento quirúrgico.Aim: To analyze the results of surgical interventions due to bronchiectasias at the Thoracic Surgery Department of the Dr. R. A. Calderón Guardia Hospital. Methods: In order to review the results of 44 surgical interventions due to bronchiectasias at the Thoracic Surgery Department of Calderón Guardia Hospital, the clinical files of 36 patients were examined. Results: A significant prevalence of the disease in female patients was observed, in proportion of 11 to 1. In most cases, causal

  4. Shared Magnetics Hall Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In the proposed Phase II program, Busek Co. will demonstrate an innovative methodology for clustering Hall thrusters into a high performance, very high power...

  5. Shared Magnetics Hall Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In the proposed Phase I program, Busek Co. will demonstrate an innovative methodology for clustering Hall thrusters into a high performance, very high power...

  6. "Hall mees" Linnateatris / Triin Sinissaar

    Index Scriptorium Estoniae

    Sinissaar, Triin

    1999-01-01

    Tallinn Linnateatri ja Raadioteatri ühislavastus "Hall mees" Gill Adamsi näidendi järgi, lavastaja Eero Spriit, osades Helene Vannari ja Väino Laes, kunstnik Kustav - Agu Püüman. Esietendus 22. okt

  7. "Hall mees" Linnateatris / Triin Sinissaar

    Index Scriptorium Estoniae

    Sinissaar, Triin

    1999-01-01

    Tallinn Linnateatri ja Raadioteatri ühislavastus "Hall mees" Gill Adamsi näidendi järgi, lavastaja Eero Spriit, osades Helene Vannari ja Väino Laes, kunstnik Kustav - Agu Püüman. Esietendus 22. okt

  8. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  9. General footage ISOLDE experimental hall HD

    CERN Multimedia

    2016-01-01

    Overview of the ISOLDE experimental hall. Equipment and experiments. Taken from the WITCH / EBIS platform: ISOLDE hall infrastructure, GHM line, LA1, LA2, LA0, central beamline, COLLAPS experiment, CRIS experiment, ISOLTRAP experiment, laser guidance from building 508 into the hall for laser spectroscopy COLLAPS and CRIS. Taken from the HIE ISOLDE shielding tunnel roof: ISOLDE hall infrastructure, WITCH experiment, VITO line, TAS experiment. General footage: High Tension room entrance and EBIS platform, staircases and passages in the experimental hall.

  10. Sheldon-Hall syndrome

    Directory of Open Access Journals (Sweden)

    Bamshad Michael J

    2009-03-01

    Full Text Available Abstract Sheldon-Hall syndrome (SHS is a rare multiple congenital contracture syndrome characterized by contractures of the distal joints of the limbs, triangular face, downslanting palpebral fissures, small mouth, and high arched palate. Epidemiological data for the prevalence of SHS are not available, but less than 100 cases have been reported in the literature. Other common clinical features of SHS include prominent nasolabial folds, high arched palate, attached earlobes, mild cervical webbing, short stature, severe camptodactyly, ulnar deviation, and vertical talus and/or talipes equinovarus. Typically, the contractures are most severe at birth and non-progressive. SHS is inherited in an autosomal dominant pattern but about half the cases are sporadic. Mutations in either MYH3, TNNI2, or TNNT3 have been found in about 50% of cases. These genes encode proteins of the contractile apparatus of fast twitch skeletal muscle fibers. The diagnosis of SHS is based on clinical criteria. Mutation analysis is useful to distinguish SHS from arthrogryposis syndromes with similar features (e.g. distal arthrogryposis 1 and Freeman-Sheldon syndrome. Prenatal diagnosis by ultrasonography is feasible at 18–24 weeks of gestation. If the family history is positive and the mutation is known in the family, prenatal molecular genetic diagnosis is possible. There is no specific therapy for SHS. However, patients benefit from early intervention with occupational and physical therapy, serial casting, and/or surgery. Life expectancy and cognitive abilities are normal.

  11. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    1962-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  12. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  13. CALDER - Neutrinoless double-beta decay identification in TeO$_2$ bolometers with kinetic inductance detectors

    CERN Document Server

    Battistelli, E S; Calvo, M; Cardani, L; Casali, N; Castellano, M G; Colantoni, I; Coppolecchia, A; Cosmelli, C; Cruciani, A; de Bernardis, P; Di Domizio, S; D'Addabbo, A; Martinez, M; Masi, S; Pagnanini, L; Tomei, C; Vignati, M

    2015-01-01

    Next-generation experiments searching for neutrinoless double-beta decay must be sensitive to a Majorana neutrino mass as low as 10 meV. CUORE, an array of 988 TeO$_2$ bolometers being commissioned at Laboratori Nazionali del Gran Sasso in Italy, features an expected sensitivity of 50-130 meV at 90% C.L, that can be improved by removing the background from $\\alpha$ radioactivity. This is possible if, in coincidence with the heat release in a bolometer, the Cherenkov light emitted by the $\\beta$ signal is detected. The amount of light detected is so far limited to only 100 eV, requiring low-noise cryogenic light detectors. The CALDER project (Cryogenic wide-Area Light Detectors with Excellent Resolution) aims at developing a small prototype experiment consisting of TeO$_2$ bolometers coupled to new light detectors based on kinetic inductance detectors. The R&D is focused on the light detectors that could be implemented in a next-generation neutrinoless double-beta decay experiment.

  14. Reactor Neutrinos

    OpenAIRE

    Soo-Bong Kim; Thierry Lasserre; Yifang Wang

    2013-01-01

    We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very ...

  15. BOILING REACTORS

    Science.gov (United States)

    Untermyer, S.

    1962-04-10

    A boiling reactor having a reactivity which is reduced by an increase in the volume of vaporized coolant therein is described. In this system unvaporized liquid coolant is extracted from the reactor, heat is extracted therefrom, and it is returned to the reactor as sub-cooled liquid coolant. This reduces a portion of the coolant which includes vaporized coolant within the core assembly thereby enhancing the power output of the assembly and rendering the reactor substantially self-regulating. (AEC)

  16. Iodine Hall Thruster

    Science.gov (United States)

    Szabo, James

    2015-01-01

    Iodine enables dramatic mass and cost savings for lunar and Mars cargo missions, including Earth escape and near-Earth space maneuvers. The demonstrated throttling ability of iodine is important for a singular thruster that might be called upon to propel a spacecraft from Earth to Mars or Venus. The ability to throttle efficiently is even more important for missions beyond Mars. In the Phase I project, Busek Company, Inc., tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high-flow iodine feed system and supported by an existing Busek hollow cathode flowing xenon gas. The Phase I propellant feed system was evolved from a previously demonstrated laboratory feed system. Throttling of the thruster between 2 and 11 kW at 200 to 600 V was demonstrated. Testing showed that the efficiency of iodine fueled BHT-8000 is the same as with xenon, with iodine delivering a slightly higher thrust-to-power (T/P) ratio. In Phase II, a complete iodine-fueled system was developed, including the thruster, hollow cathode, and iodine propellant feed system. The nominal power of the Phase II system is 8 kW; however, it can be deeply throttled as well as clustered to much higher power levels. The technology also can be scaled to greater than 100 kW per thruster to support megawatt-class missions. The target thruster efficiency for the full-scale system is 65 percent at high specific impulse (Isp) (approximately 3,000 s) and 60 percent at high thrust (Isp approximately 2,000 s).

  17. Application of LY-C2-12 D catalyst in C2 hydrogenation isothermal reactor of 330 kt·a-1 ethylene plant%LY-C2-12 D催化剂在330 kt · a-1乙烯装置碳二加氢等温反应器的工业应用

    Institute of Scientific and Technical Information of China (English)

    赵玉龙

    2015-01-01

    中国石油大庆石化公司330 kt·a-1乙烯装置是我国较早成套引进的乙烯装置。该装置碳二加氢一段反应器采用等温反应器,列管之间使用丁烷为冷却介质。第一段反应器采用新型LY-C2-12 D催化剂,运转初期乙烯选择性为80%,运行6个多月,平均选择性达70%,表明该催化剂具有良好的稳定性。%330 kt·a-1 ethylene plant in PetroChina Daqing Petrochemical Co. is one of the earliest im-ported ethylene plants in China. The isothermal reactor is applied as C2 hydrogenation reactor and butane is used for cooling medium among the tubes. The new LY-C2-12D catalyst was applied in the first stage reactor. The selectivity to ethylene reached 80% in initial running period,and the average selectivity was up to 70%,which indicated that the catalyst possessed good stability.

  18. Membrane reactor. Membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shindo, Y.; Wakabayashi, K. (National Chemical Laboratory for Industry, Tsukuba (Japan))

    1990-08-05

    Many reaction examples were introduced of membrane reactor, to be on the point of forming a new region in the field of chemical technology. It is a reactor to exhibit excellent function, by its being installed with membrane therein, and is generally classified into catalyst function type and reaction promotion type. What firstly belongs to the former is stabilized zirconia, where oxygen, supplied to the cathodic side of membrane with voltage, impressed thereon, becomes O {sup 2 {minus}} to be diffused through the membrane and supplied, as variously activated oxygenous species, on the anodic side. Examples with many advantages can be given such as methane coupling, propylene oxidation, methanating reaction of carbon dioxide, etc. Apart, palladium film and naphion film also belong to the former. While examples of the latter comprise, among others, decomposition of hydrogen sulfide by porous glass film and dehydrogenation of cyclohexane or palladium alloy film, which are expected to be developed and materialized in the industry. 33 refs., 8 figs.

  19. La identidad nacional y Calderón en la polémica teatral de 1762-1764

    Directory of Open Access Journals (Sweden)

    Bezhanova, Olga

    2004-06-01

    Full Text Available Drawing on contemporary theories about national identity, legitimacy and intellectual authority this article explores identitarian issues at stake during the 1762-1764 controversy on Spanish theater. Re-reading texts by Clavijo y Fajardo (El Pensador, Nicolás Fernández de Moratín (Desengaños al teatro español and other writings, Mariano José Nipho (Diario Estrangero and La nación española defendida and José Romea y Tapia (El escritor sin título we contend that what these authors are debating indeed is not theater but the legitimacy and authority they are claiming for, and ultimately opposing conceptions of national identity. Calderón becoming a cultural icon of such identity. Particularly significant is the role of autos sacramentales in this context. In effect, acrimony and irritation are part of this polemics because orthodox Catholicism is, from a conservative point of view, an essential component of what they consider Spanish national identity. The prohibition of the autos is just a sign of a temporary change in the relationship of forces.A partir de teorías actuales sobre la identidad nacional, la legitimidad y la autoridad intelectual, este artículo explora los puntos clave identitarios que se ponen en juego durante la polémica sobre el teatro español de los años 1762-1764. Mediante una re-lectura de los textos de Clavijo y Fajardo (El Pensador, Nicolás Fernández de Moratín (Desengaños al teatro español y otros escritos, Mariano José Nipho (Diario Estrangero y La nación española defendida y José Romea y Tapia (El escritor sin título, sostenemos que lo que estos autores discuten realmente no es sobre el teatro, sino sobre la legitimidad y autoridad que reclaman, y en último término concepciones enfrentadas sobre la identidad nacional, de la que Calderón parece convertirse en icono cultural. De particular significación es el papel de los autos sacramentales en este contexto. En efecto, la acritud y la irritaci

  20. Acalasia, experiencia de 6 años. Hospital "Dr. Rafael Ángel Calderón Guardia" (2001-2007)

    OpenAIRE

    Viviana Hernández-de Mezerville; Edgar Izquierdo-Sandí; Gerardo Avendaño-Alvarado; Ricardo Barahona-García; Alessia Ávalos-Giugliarelli; Rolando Páez-Sáenz; Rigoberto Salas-Aguilar

    2009-01-01

    Objetivos: Caracterizar la población de pacientes vistos con esta entidad en el Hospital "Dr. Rafael Angel Calderón Guardia" durante los últimos 6 años y determinar su presentación clínica, método(s) de diagnóstico utilizado (s), tratamiento brindado y evolución durante el primer año postratamiento. Materiales y métodos: Se analizaron los expedientes clínicos de hospitalización de los pacientes con acalasia atendidos desde enero de 2001 hasta enero de 2007; luego se revisaron las notas de evo...

  1. High-order Div- and Quasi Curl-Conforming Basis Functions for Calderón Multiplicative Preconditioning of the EFIE

    KAUST Repository

    Valdes, Felipe

    2011-04-01

    A new high-order Calderón multiplicative preconditioner (HO-CMP) for the electric field integral equation (EFIE) is presented. In contrast to previous CMPs, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of high-order quasi curl-conforming basis functions. Like its predecessors, the HO-CMP can be seamlessly integrated into existing EFIE codes. Numerical results demonstrate that the linear systems of equations obtained using the proposed HO-CMP converge rapidly, regardless of the mesh density and of the order of the current expansion. © 2006 IEEE.

  2. La imagen de Dánae en “El mágico prodigioso” de Calderón: Terencio, San Agustín y fray Manuel de Guerra y Ribera

    OpenAIRE

    De Armas, F. A. (Frederick A.)

    2008-01-01

    Análisis de “El mágico prodigioso” como comedia de santos de Calderón que sube al tablado el choque entre paganismo y cristianismo, con especial atención al juego de écfrasis derivado de explotar la imagen de Dánae como símbolo de erotismo y lascivia jupiterina. Calderón reutiliza en el texto el motivo de Dánae, citado por tratadistas clásicos y modernos (Terencio, San Agustín, fray Manuel de Guerra) y grabado en la memoria colectiva gracias al cuadro que Tiziano pintó para Felipe II....

  3. Displacement ventilation in lecture halls

    OpenAIRE

    Egorov, Artem

    2013-01-01

    This thesis considers several important goals. The main purpose is to see how displacement ventilation sys-tem works in the lecture hall of M-building and compare obtained results with D2 and Indoor Climate Classi-fication. The second one is to analyze the function of the ventilation system. The last one is to realize when displacement ventilation is preferable to mixing ventilation. Analysis of the system was carried out with instruments from MUAS HVAC laboratory. In lecture hall were me...

  4. Decommissioning of the Salaspils Research Reactor

    Directory of Open Access Journals (Sweden)

    Abramenkovs Andris

    2011-01-01

    Full Text Available In May 1995, the Latvian government decided to shut down the Salaspils Research Reactor and to dispense with nuclear energy in the future. The reactor has been out of operation since July 1998. A conceptual study on the decommissioning of the Salaspils Research Reactor was drawn up by Noell-KRC-Energie- und Umwelttechnik GmbH in 1998-1999. On October 26th, 1999, the Latvian government decided to start the direct dismantling to “green-field” in 2001. The upgrading of the decommissioning and dismantling plan was carried out from 2003-2004, resulting in a change of the primary goal of decommissioning. Collecting and conditioning of “historical” radioactive wastes from different storages outside and inside the reactor hall became the primary goal. All radioactive materials (more than 96 tons were conditioned for disposal in concrete containers at the radioactive wastes depository “Radons” at the Baldone site. Protective and radiation measurement equipment of the personnel was upgraded significantly. All non-radioactive equipment and materials outside the reactor buildings were released for clearance and dismantled for reuse or conventional disposal. Contaminated materials from the reactor hall were collected and removed for clearance measurements on a weekly basis.

  5. Low-frequency noise in planar Hall effect bridge sensors

    DEFF Research Database (Denmark)

    Persson, Anders; Bejhedb, R.S.; Bejhed, R.S.

    2011-01-01

    The low-frequency characteristics of planar Hall effect bridge sensors are investigated as function of the sensor bias current and the applied magnetic field. The noise spectra reveal a Johnson-like spectrum at high frequencies, and a 1/f-like excess noise spectrum at lower frequencies, with a knee...

  6. Bound values for Hall conductivity of heterogeneous medium under quantum Hall effect conditions

    Indian Academy of Sciences (India)

    V E Arkhincheev

    2008-02-01

    Bound values for Hall conductivity under quantum Hall effect (QHE) conditions in inhomogeneous medium has been studied. It is shown that bound values for Hall conductivity differ from bound values for metallic conductivity. This is due to the unusual character of current percolation under quantum Hall effect conditions.

  7. Development of a decommissioning strategy for the MR research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bylkin, Boris; Gorlinsky, Yury; Kolyadin, Vyacheslav; Pavlenko, Vitaly [RRC Kurchatov Institute, Moscow (Russian Federation); Craig, David; Fecitt, Lorna [NUKEM Limited, Dounreay (United Kingdom); Harman, Neil; Jackson, Roger [Serco Technical and Assurance Services, Warrington (United Kingdom); Lobach, Yury [Inst. for Nuclear Research of NASU, Kiev (Ukraine)

    2010-03-15

    A description of the selected decommissioning strategy for the research reactor MR at the site of the Kurchatov Institute in Moscow is presented. The MR reactor hall is planned to be used as a temporary fuel store for the other research reactors on the site. On the basis of the site-specific conditions and over-all decommissioning goals, it was identified that phased immediate decommissioning is the preferable option. The current status of the reactor, expected final conditions and the sequence of decommissioning works are shown. (orig.)

  8. Berry curvature and various thermal Hall effects

    Science.gov (United States)

    Zhang, Lifa

    2016-10-01

    Applying the approach of semiclassical wave packet dynamics, we study various thermal Hall effects where carriers can be electron, phonon, magnon, etc. A general formula of thermal Hall conductivity is obtained to provide an essential physics for various thermal Hall effects, where the Berry phase effect manifests naturally. All the formulas of electron thermal Hall effect, phonon Hall effect, and magnon Hall effect can be directly reproduced from the general formula. It is also found that the Strěda formula can not be directly applied to the thermal Hall effects, where only the edge magnetization contributes to the Hall effects. Furthermore, we obtain a combined formula for anomalous Hall conductivity, thermal Hall electronic conductivity and thermal Hall conductivity for electron systems, where the Berry curvature is weighted by a different function. Finally, we discuss particle magnetization and its relation to angular momentum of the carrier, change of which could induce a mechanical rotation; and possible experiments for thermal Hall effect associated with a mechanical rotation are also proposed.

  9. The Other Hall Effect: College Board Physics

    Science.gov (United States)

    Sheppard, Keith; Gunning, Amanda M.

    2013-01-01

    Edwin Herbert Hall (1855-1938), discoverer of the Hall effect, was one of the first winners of the AAPT Oersted Medal for his contributions to the teaching of physics. While Hall's role in establishing laboratory work in high schools is widely acknowledged, his position as chair of the physics section of the Committee on College Entrance…

  10. A Gift for Reading Hall No. 1

    Science.gov (United States)

    MacWilliams, Bryon

    2009-01-01

    In this article, the author describes Reading Hall No. 1 of the Russian State Library. He was placed in the first reading hall in the mid-1990s, when the Russian government still honored Soviet traditions of granting certain privileges to certain foreigners. In the first hall, the rules are different. He can request as many books as he wants. He…

  11. Cleaner in Hall of Residence

    Science.gov (United States)

    Hotel and Catering Industry Training Board, Wembley (England).

    This syllabus is intended for the use of training personnel in drawing up training programs for cleaners in halls of residence. Its main objective is to produce fully trained cleaners, thereby maintaining and raising standards. The syllabus is divided into three sections: Introduction to Housekeeping Employees, and Tasks Performed by the Majority…

  12. Hall / Madle Mühlbach

    Index Scriptorium Estoniae

    Mühlbach, Madle

    2008-01-01

    Hallist värvusest interjööris, olles oma passiivsuses ja lakoonilisuses nii efektne, kui seda ilmestab mõni värvikam detail või neutraalne tasakaalustaja. Lk. 73 Eva Toome valitud halle esemeid müügivõrgust

  13. ATLAS Assembly Hall Open Day

    CERN Document Server

    Patrice Loiez

    2004-01-01

    To mark the 50th Anniversary of the founding of CERN, a day of tours, displays and presentations was held in October 2004. The assembly halls for the experiments that were waiting to be installed on the LHC, such as ATLAS shown here, were transformed into display areas and cafés.

  14. Descripción y análisis de capas superpuestas en El castillo de Lindabridis de Calderón

    Directory of Open Access Journals (Sweden)

    Escudero Baztán, Juan Manuel

    2015-06-01

    Full Text Available This paper describes and analyzes the highlights of a play El castillo de Lindabridis of Calderón de la Barca: topics relating to the date of his writing and his performances in the seventeenth century, the management of chivalric sources, the unitary structure, the use of emblematic material through the medieval bestiaries, musical interludes, and the staging and the repetition of themes and motifs, along with some final considerations about gender. All these factors indicate the particular importance of this comedy of Calderón.Este trabajo describe y analiza los puntos más relevantes de una obra caballeresca calderoniana poco conocida como El castillo de Lindabridis: cuestiones relativas a la fecha de su escritura y sus representaciones en el siglo XVII, al manejo de las fuentes caballerescas, a la estructura unitaria, al uso de la emblemática a través de los bestiarios medievales, a los interludios musicales, a la escenificación y la repetición de temas y motivos, junto a unas consideraciones finales sobre el género. Elementos en su conjunto que indican la particular relevancia de esta comedia de gran espectáculo calderoniana.

  15. Planar Hall effect bridge magnetic field sensors

    Science.gov (United States)

    Henriksen, A. D.; Dalslet, B. T.; Skieller, D. H.; Lee, K. H.; Okkels, F.; Hansen, M. F.

    2010-07-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.

  16. Optical Hall effect-model description: tutorial.

    Science.gov (United States)

    Schubert, Mathias; Kühne, Philipp; Darakchieva, Vanya; Hofmann, Tino

    2016-08-01

    The optical Hall effect is a physical phenomenon that describes the occurrence of magnetic-field-induced dielectric displacement at optical wavelengths, transverse and longitudinal to the incident electric field, and analogous to the static electrical Hall effect. The electrical Hall effect and certain cases of the optical Hall effect observations can be explained by extensions of the classic Drude model for the transport of electrons in metals. The optical Hall effect is most useful for characterization of electrical properties in semiconductors. Among many advantages, while the optical Hall effect dispenses with the need of electrical contacts, electrical material properties such as effective mass and mobility parameters, including their anisotropy as well as carrier type and density, can be determined from the optical Hall effect. Measurement of the optical Hall effect can be performed within the concept of generalized ellipsometry at an oblique angle of incidence. In this paper, we review and discuss physical model equations, which can be used to calculate the optical Hall effect in single- and multiple-layered structures of semiconductor materials. We define the optical Hall effect dielectric function tensor, demonstrate diagonalization approaches, and show requirements for the optical Hall effect tensor from energy conservation. We discuss both continuum and quantum approaches, and we provide a brief description of the generalized ellipsometry concept, the Mueller matrix calculus, and a 4×4 matrix algebra to calculate data accessible by experiment. In a follow-up paper, we will discuss strategies and approaches for experimental data acquisition and analysis.

  17. Multifunctional reactors

    NARCIS (Netherlands)

    Westerterp, K.R.

    1992-01-01

    Multifunctional reactors are single pieces of equipment in which, besides the reaction, other functions are carried out simultaneously. The other functions can be a heat, mass or momentum transfer operation and even another reaction. Multifunctional reactors are not new, but they have received much

  18. La cisma de Enrique VIII: ambición y dignidad. Catalina de Aragón y Ana Bolena en el imaginario de Calderón y Shakespeare

    OpenAIRE

    Vallejo Mateo, María Luisa

    2015-01-01

    El artículo tiene como finalidad comparar el tratamiento que dan Calderón y Shakespeare a sus personajes femeninos principales en La cisma de Ingalaterra y Enrique VIII, en torno a los conceptos de dignidad y ambición, que marcan su manera de ser y est

  19. Pedro Calderón de la Barca, La vida es sueño. Edición crítica de las dos versiones del auto y de la loa, ed. F. Plata Parga

    Directory of Open Access Journals (Sweden)

    Alejandro García-Reidy

    2013-10-01

    Full Text Available Review of Pedro Calderón de la Barca, La vida es sueño. Edición crítica de las dos versiones del auto y de la loa, ed. F. Plata Parga, Reichenberger / Universidad de Navarra (Autos sacramentales completos, 79, Kassel / Pamplona, 2012, 294 pp. ISBN: 978-3-944244-01-3.

  20. Electron dynamics in Hall thruster

    Science.gov (United States)

    Marini, Samuel; Pakter, Renato

    2015-11-01

    Hall thrusters are plasma engines those use an electromagnetic fields combination to confine electrons, generate and accelerate ions. Widely used by aerospace industries those thrusters stand out for its simple geometry, high specific impulse and low demand for electric power. Propulsion generated by those systems is due to acceleration of ions produced in an acceleration channel. The ions are generated by collision of electrons with propellant gas atoms. In this context, we can realize how important is characterizing the electronic dynamics. Using Hamiltonian formalism, we derive the electron motion equation in a simplified electromagnetic fields configuration observed in hall thrusters. We found conditions those must be satisfied by electromagnetic fields to have electronic confinement in acceleration channel. We present configurations of electromagnetic fields those maximize propellant gas ionization and thus make propulsion more efficient. This work was supported by CNPq.

  1. Symmetric functions and Hall polynomials

    CERN Document Server

    MacDonald, Ian Grant

    1998-01-01

    This reissued classic text is the acclaimed second edition of Professor Ian Macdonald's groundbreaking monograph on symmetric functions and Hall polynomials. The first edition was published in 1979, before being significantly expanded into the present edition in 1995. This text is widely regarded as the best source of information on Hall polynomials and what have come to be known as Macdonald polynomials, central to a number of key developments in mathematics and mathematical physics in the 21st century Macdonald polynomials gave rise to the subject of double affine Hecke algebras (or Cherednik algebras) important in representation theory. String theorists use Macdonald polynomials to attack the so-called AGT conjectures. Macdonald polynomials have been recently used to construct knot invariants. They are also a central tool for a theory of integrable stochastic models that have found a number of applications in probability, such as random matrices, directed polymers in random media, driven lattice gases, and...

  2. Reactor vessel

    OpenAIRE

    Makkee, M.; Kapteijn, F.; Moulijn, J.A

    1999-01-01

    A reactor vessel (1) comprises a reactor body (2) through which channels (3) are provided whose surface comprises longitudinal inwardly directed parts (4) and is provided with a catalyst (6), as well as buffer bodies (8, 12) connected to the channels (3) on both sides of the reactor body (2) and comprising connections for supplying (9, 10, 11) and discharging (13, 14, 15) via the channels (3) gases and/or liquids entering into a reaction with each other and substances formed upon this reactio...

  3. Chemical Reactors.

    Science.gov (United States)

    Kenney, C. N.

    1980-01-01

    Describes a course, including content, reading list, and presentation on chemical reactors at Cambridge University, England. A brief comparison of chemical engineering education between the United States and England is also given. (JN)

  4. Reactor Neutrinos

    Directory of Open Access Journals (Sweden)

    Soo-Bong Kim

    2013-01-01

    Full Text Available We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very recently the most precise determination of the neutrino mixing angle θ13. This paper provides an overview of the upcoming experiments and of the projects under development, including the determination of the neutrino mass hierarchy and the possible use of neutrinos for society, for nonproliferation of nuclear materials, and geophysics.

  5. NUCLEAR REACTOR

    Science.gov (United States)

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  6. Reactor Engineering

    Science.gov (United States)

    Lema, Juan M.; López, Carmen; Eibes, Gemma; Taboada-Puig, Roberto; Moreira, M. Teresa; Feijoo, Gumersindo

    In this chapter, the engineering aspects of processes catalyzed by peroxidases will be presented. In particular, a discussion of the existing technologies that utilize peroxidases for different purposes, such as the removal of recalcitrant compounds or the synthesis of polymers, is analyzed. In the first section, the essential variables controlling the process will be investigated, not only those that are common in any enzymatic system but also those specific to peroxidative reactions. Next, different reactor configurations and operational modes will be proposed, emphasizing their suitability and unsuitability for different systems. Finally, two specific reactors will be described in detail: enzymatic membrane reactors and biphasic reactors. These configurations are especially valuable for the treatment of xenobiotics with high and poor water solubility, respectively.

  7. Spin Hall effect by surface roughness

    KAUST Repository

    Zhou, Lingjun

    2015-01-08

    The spin Hall and its inverse effects, driven by the spin orbit interaction, provide an interconversion mechanism between spin and charge currents. Since the spin Hall effect generates and manipulates spin current electrically, to achieve a large effect is becoming an important topic in both academia and industries. So far, materials with heavy elements carrying a strong spin orbit interaction, provide the only option. We propose here a new mechanism, using the surface roughness in ultrathin films, to enhance the spin Hall effect without heavy elements. Our analysis based on Cu and Al thin films suggests that surface roughness is capable of driving a spin Hall angle that is comparable to that in bulk Au. We also demonstrate that the spin Hall effect induced by surface roughness subscribes only to the side-jump contribution but not the skew scattering. The paradigm proposed in this paper provides the second, not if only, alternative to generate a sizable spin Hall effect.

  8. Reactor Neutrinos

    OpenAIRE

    Lasserre, T.; Sobel, H.W.

    2005-01-01

    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrin...

  9. Reseción esofágica por cáncer, experiencia del Servicio de Cirugía de Tórax del Hospital Dr. Rafael Á. Calderón Guardia

    Directory of Open Access Journals (Sweden)

    José Alberto Mainieri-Hidalgo

    2007-10-01

    Full Text Available Durante el período comprendido entre 1990 y 2006, 28 pacientes fueron sometidos a resección esofágica por cáncer en el Servicio de Cirugía de Tórax del Hospital Dr. Rafael Á. Calderón Guardia. La edad promedio fue de 65 años y la relación hombre mujer, de 6 a 1. El antecedente de tabaquismo se confirmó en un 80%, etilismo en un 75% y 8 pacientes eran conocidos portadores de esófago de Barret. Disfagia, dolor epigástrico y pérdida de peso fueron los síntomas más frecuentes; siendo la epigastralgia debida a otra patología digestiva coexistente, como reflujo o enfermedad péptica. Los pacientes clasificados como estadio IIb, III y IV recibieron terapia de inducción y aunque en 3 de estos no se encontró tumor residual en la pieza quirúrgica, en 2 casos quedó tumor adherido a la aorta. A 21 pacientes se les realizó esofagectomía total con ascenso gástrico y anastomosis cervical y a 7 esofagectomía parcial con ascenso gástrico al tórax en 5 y 2 esófago-yeyuno anastomosis, una intratorácica y otra abdominal. La complicación más frecuente fue la claudicación respiratoria por bronconeumonía, que se produjo en 7 pacientes y que fue mortal en 3. Dos de estos pacientes presentaron además fuga de anastomosis, una en el cuello y otra en el tórax. A largo plazo la complicación más frecuente fue estrechez de la anastomosis, que en los 7 casos se ha manejado con dilataciones. La mortalidad quirúrgica fue del 10.7% y en los 3 casos la bronconeumonía fue la causa principal. La supervivencia a 5 y 10 años fue del 31.5% y el 18%, respectivamente.Between 1990 and 2006, 28 patients had esophageal cancer resection at the Department of Thoracic Surgery of the Hospital Calderón Guardia of the Costa Rican Social Security System. The mean age was 65 years with a high male predominance of 6:1. Eighty percent of the patients were smokers, 75% drinkers and 8 patients had previous diagnosis of Barret’s esophagus. Dysphagia, epigastric

  10. Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yang; Feng, Xiao; Ou, Yunbo; Wang, Jing; Liu, Chang; Zhang, Liguo; Zhao, Dongyang; Jiang, Gaoyuan; Zhang, Shou-Cheng; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Yayu

    2015-09-16

    We report experimental investigations on the quantum phase transition between the two opposite Hall plateaus of a quantum anomalous Hall insulator. We observe a well-defined plateau with zero Hall conductivity over a range of magnetic field around coercivity when the magnetization reverses. The features of the zero Hall plateau are shown to be closely related to that of the quantum anomalous Hall effect, but its temperature evolution exhibits a significant difference from the network model for a conventional quantum Hall plateau transition. We propose that the chiral edge states residing at the magnetic domain boundaries, which are unique to a quantum anomalous Hall insulator, are responsible for the novel features of the zero Hall plateau.

  11. Low-Voltage Hall Thruster Mode Transitions

    Science.gov (United States)

    2014-06-01

    Technical Paper 3. DATES COVERED (From - To) June 2014- July 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER In-House Low-Voltage Hall Thruster Mode...ABSTRACT Past investigations of the 6kW-class H6 Hall thruster during low-voltage operation revealed two operating modes, corresponding to the...topologies were characterized for the H6 Hall thruster from 100V to 200V discharge, with variation in cathode flow fraction, cathode position inside and

  12. Listening to the acoustics in concert halls

    Science.gov (United States)

    Beranek, Leo L.; Griesinger, David

    2004-05-01

    How does acoustics affect the symphonic music performed in a concert hall? The lecture begins with an illustrated discussion of the architectural features that influence the acoustics. Boston Symphony Hall, which was built in 1900 when only one facet of architectural design was known, now rates as one of the world's great halls. How this occurred will be presented. Music is composed with some acoustical environment in mind and this varies with time from the Baroque to the Romantic to the Modern musical period. Conductors vary their interpretation according to the hall they are in. Well-traveled listeners and music critics have favorite halls. The lecture then presents a list of 58 halls rank ordered according to their acoustical quality based on interviews of music critics and conductors. Modern acoustical measurements made in these halls are compared with their rankings. Music recordings will be presented that demonstrate how halls sound that have different measured acoustical parameters. Photographs of a number of recently built halls are shown as examples of how these known acoustical factors have been incorporated into architectural design.

  13. Hall probes: physics and application to magnetometry

    CERN Document Server

    Sanfilippo, S

    2010-01-01

    This lecture aims to present an overview of the properties of Hall effect devices. Descriptions of the Hall phenomenon, a review of the Hall effect device characteristics and of the various types of probes are presented. Particular attention is paid to the recent development of three-axis sensors and the related techniques to cancel the offsets and the planar Hall effect. The lecture introduces the delicate problem of the calibration of a three-dimensional sensor and ends with a section devoted to magnetic measurements in conventional beam line magnets and undulators.

  14. DEVELOPMENT OF IMPROVED HALL EFFECT SENSORS.

    Science.gov (United States)

    HALL EFFECT , MAGNETOMETERS, GAIN, SENSITIVITY, MAGNETIC FIELDS, DETECTION, ELECTROMAGNETIC PROBES, WEIGHT, VOLUME, BATTERY COMPONENTS, INDIUM ALLOYS, ANTIMONY ALLOYS, FERRITES, MANPORTABLE EQUIPMENT.

  15. AN A. C. HALL EFFECT GAUSSMETER,

    Science.gov (United States)

    MEASURING INSTRUMENTS, MEASURING INSTRUMENTS, HALL EFFECT , MAGNETOMETERS, MEASUREMENT, GENERATORS, CIRCUITS, ALTERNATING CURRENT, GERMANIUM, SEMICONDUCTOR DIODES, GALVANOMETERS, VOLTAGE, DIRECT CURRENT, MAGNETIC FIELDS.

  16. Lectures on the Quantum Hall Effect

    CERN Document Server

    Tong, David

    2016-01-01

    The purpose of these lectures is to describe the basic theoretical structures underlying the rich and beautiful physics of the quantum Hall effect. The focus is on the interplay between microscopic wavefunctions, long-distance effective Chern-Simons theories, and the modes which live on the boundary. The notes are aimed at graduate students in any discipline where $\\hbar=1$. A working knowledge of quantum field theory is assumed. Contents: 1. The Basics (Landau levels and Berry phase). 2. The Integer Quantum Hall Effect. 3. The Fractional Quantum Hall Effect. 4. Non-Abelian Quantum Hall States. 5. Chern-Simons Theories. 6. Edge Modes.

  17. Anomalous Hall effect in polycrystalline Ni films

    KAUST Repository

    Guo, Zaibing

    2012-02-01

    We systematically studied the anomalous Hall effect in a series of polycrystalline Ni films with thickness ranging from 4 to 200 nm. It is found that both the longitudinal and anomalous Hall resistivity increased greatly as film thickness decreased. This enhancement should be related to the surface scattering. In the ultrathin films (46 nm thick), weak localization corrections to anomalous Hall conductivity were studied. The granular model, taking into account the dominated intergranular tunneling, has been employed to explain this phenomenon, which can explain the weak dependence of anomalous Hall resistivity on longitudinal resistivity as well. © 2011 Elsevier Ltd. All rights reserved.

  18. La figura de don Rodrigo Calderón a través de la literatura (s. 17-21)

    OpenAIRE

    Diallo, Karidjatou

    2009-01-01

    D. Rodrigo Calderón, prócer de finales del XVI y principios del XVII, salió a la palestra política gracias a su ingenio y a su amistad con el duque de Lerma. En breve tiempo amasó una gran fortuna, se convirtió en un alto cargo del reinado de Felipe III e incluso, llevó las riendas del Estado Español. Analizar su figura en la literatura española del XVII al XXI es un enfoque novedoso en la medida en que por vez primera se aborda su vida y muerte desde una perspectiva literaria, es decir, reun...

  19. «Entre los sueltos caballos» en El príncipe constante: la glosa de Calderón y su significado en la comedia

    OpenAIRE

    Hernando Morata, Isabel

    2011-01-01

    Hacia el final de la primera jornada de El príncipe constante Calderón hace presentes en su comedia a dos de los hombres de letras más importantes de su época: el predicador fray Hortensio Paravicino y el poeta, fallecido tan sólo dos años atrás, don Luis de Góngora. Pero si al primero le ataca por medio de la alusión jocosa del gracioso Brito, al segundo le homenajea introduciendo varios versos de un conocido romance suyo, «Entre los sueltos caballos», en un diálogo entre el i...

  20. Secrets and Secrecy in Calderón's Comedies and in Spanish Golden Age Culture. Outline of a New Research Focus in Calderonian Studies

    Directory of Open Access Journals (Sweden)

    Wolfram Aichinger

    2013-11-01

    Full Text Available The public enactment of secrecy is part of the Spanish Golden Age culture. This article presents a research project, which pursues three objectives: 
A study of secrecy as a core characteristic of Spanish Golden Age culture, on the basis of historiographical studies, sources and cultural theories of secrecy.
 A study of Calderonian comedies of secrecy in the context of Golden Age theatre.
 A case study of the comedy El secreto a voces, including a critical edition that also explores the aesthetics of secrecy and the history of early staging in Madrid and Vienna.
 With this threefold approach we aim at a deeper understanding of both Calderón’s originality and of the secret patterns of Baroque culture.

  1. Análisis de los factores de riesgo de prematuridad en el Hospital Calderón Guardia de enero a agosto 2001

    Directory of Open Access Journals (Sweden)

    Bernardo Goldstein Sandoval

    2003-03-01

    Full Text Available En esta investigación se plantea los factores asociados al riesgo de prematuridad que incide notablemente en la salud pública costarricense. El objetivo general del estudio es: Analizar los factores de riesgo de prematuridad en el Hospital Calderón Guardia de enero a agosto 2001 mediante un modelo de Regresión Logística. Para lograr este propósito se determinaron los factores que presentan asociación significativa con el parto prematuro y se cuantificó el grado de asociación entre factores de riesgo y parto de pretérmino. Métodos: Este es un estudio retrospectivo que analiza expedientes médicos de pacientes embarazadas que tuvieron su parto en el Hospital Calderón Guardia de enero a agosto 2001. A una muestra representativa de un total de 5061 expedientes del Servicio de Obstetricia del Hospital Calderón Guardia, en relación con nacimientos ocurridos de enero a agosto 2001 se les aplicó una revisión general, con el propósito básico de identificar factores de riesgo asociados con prematuridad. Para lograr lo anterior se tomó una muestra de expedientes estadísticamente significativa. El total de expedientes es de 5061 y el tamaño de la muestra es de 291, con un nivel de confianza de un 95% y con un error máximo permisible de un 5%. Resultados: El 43% de la muestra de partos (290 partos de 5061 ocurridos entre enero y agosto de 2001 en el Hospital Calderón Guardia corresponden a prematuros (casos y el 57% restantes son de término (controles. La anterior muestra se relaciona con un nivel de confianza del 95%. El modelo de Regresión Logística obtenido se puede representar mediante el logit: _(x= 2,5022 - 0,0241DS - 0,283CP + 3,077PREPREM + 2,206 HTAPRE + 0,649 HTAIE + 1,355 RPM + 3,174 GEMELOS Los valores estimados de los coeficientes b no pueden interpretarse directamente como probabilidades, sino como variaciones en el índice estimado de propensión (score. Las variables que resultaron estadísticamente significativas al

  2. Timectomía por miastenia gravis en el Hospital Dr. Rafael Angel Calderón Guardia: Reporte de 24 casos

    Directory of Open Access Journals (Sweden)

    José A Mainieri Hidalgo

    2000-06-01

    Full Text Available Antecedentes: La miastenia gravis es una enfermedad autoinmune cuya etiología aún no está claramente definida. Desde 1912 se describió mejoría del cuadro posterior a timectomía. Este procedimiento es actualmente una de las formas aceptadas para su tratamiento. El objetivo del presente trabajo fue estudiar los resultados de la timectomía para el tratamiento de la miastenia gravis en el Hospital Rafael Angel Calderón Guardia. Materiales y Métodos: Estudio retrospectivo, basado en la revisión de los expedientes de 24 pacientes, a quienes se les realizó timectomía como parte de su tratamiento de miastenia gravis entre enero de 1992 y mayo de 1999, en el Hospital Dr. Rafael Angel Calderón Guardia. Resultados: Se encontró que un 75% de los pacientes presentaron una franca mejoría, 17% permaneció en igual condición y un 8% empeoró. No se observó diferencia en la evolución por sexo, edad o la presencia de timoma, sin embargo en los pacientes que presentaban únicamente síntomas oculares se dio una tendencia a persistir sintomáticos. Se observó que la preparación pre-operatoria del paciente con gamaglobulina y la modernización de la técnica anestésica disminuyó notablemente la necesidad de ventilación mecánica. Conclusión: La timectomía fue útil en el tratamiento del 75% de los pacientes, especialmente aquellos con no sólo ptosis palpebral y permitió disminuir la dosis de medicamentos en 12 de los 24 casos estudiados.

  3. Automated Micro Hall Effect measurements

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Henrichsen, Henrik Hartmann; Lin, Rong

    2014-01-01

    With increasing complexity of processes and variety of materials used for semiconductor devices, stringent control of the electronic properties is becoming ever more relevant. Collinear micro four-point probe (M4PP) based measurement systems have become high-end metrology methods for characteriza......With increasing complexity of processes and variety of materials used for semiconductor devices, stringent control of the electronic properties is becoming ever more relevant. Collinear micro four-point probe (M4PP) based measurement systems have become high-end metrology methods...... for characterization and monitoring of sheet resistance as well as sheet carrier density and mobility via the Micro Hall Effect (MHE) method....

  4. Temperature Gradient in Hall Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    D. Staack; Y. Raitses; N.J. Fisch

    2003-11-24

    Plasma potentials and electron temperatures were deduced from emissive and cold floating probe measurements in a 2 kW Hall thruster, operated in the discharge voltage range of 200-400 V. An almost linear dependence of the electron temperature on the plasma potential was observed in the acceleration region of the thruster both inside and outside the thruster. This result calls into question whether secondary electron emission from the ceramic channel walls plays a significant role in electron energy balance. The proportionality factor between the axial electron temperature gradient and the electric field is significantly smaller than might be expected by models employing Ohmic heating of electrons.

  5. New instruments at the upgraded JRR-3 reactor

    Science.gov (United States)

    Funahashi, Satoru

    1991-10-01

    A new JRR-3 reactor equipped with a liquid hydrogen cold source started to operate at 20 MW full power for general users in November 1990. The reactor provides seven horizontal beam holes in the reactor room and three cold guides and two thermal ones in the guide hall. In total about twenty five instruments are planned for use with the neutron beam. Eight triple-axis neutron spectrometers, two small-angle scattering machines, two high-resolution powder diffractometers, two radiography instruments are included among these. More than half of them have already been completed and the rest will be installed in the next two years.

  6. A Holographic Quantum Hall Ferromagnet

    CERN Document Server

    Kristjansen, C; Semenoff, G W

    2013-01-01

    A detailed numerical study of a recent proposal for exotic states of the D3-probe D5 brane system with charge density and an external magnetic field is presented. The state has a large number of coincident D5 branes blowing up to a D7 brane in the presence of the worldvolume electric and magnetic fields which are necessary to construct the holographic state. Numerical solutions have shown that these states can compete with the the previously known chiral symmetry breaking and maximally symmetric phases of the D3-D5 system. Moreover, at integer filling fractions, they are incompressible with integer quantized Hall conductivities. In the dual superconformal defect field theory, these solutions correspond to states which break the chiral and global flavor symmetries spontaneously. The region of the temperature-density plane where the D7 brane has lower energy than the other known D5 brane solutions is identified. A hypothesis for the structure of states with filling fraction and Hall conductivity greater than on...

  7. Infrared Hall Conductivity in Graphene

    Science.gov (United States)

    Ellis, C. T.; Kim, M.-H.; Wu, T.; Sambandamurthy, G.; Cerne, J.; Lee, V.; Banerjee, S.

    2009-03-01

    Among the many different techniques which have revealed graphene's remarkable properties, infrared conductivity (σxx) (Jiang, PRL 2007) and the DC Hall effect (Novoselov, Nature 2005; Zhang, Nature 2005; Zhang, PRL 2006) have provided new insights into this material. In our study we determine the infrared Hall conductivity (σxy) for graphene in the 120-1000 meV range at temperatures down to 7K and magnetic fields up to 7T using Faraday measurements. Unlike σxx, which measures the sum of the optical responses for left and right circularly polarized light, σxy measures the difference and therefore is sensitive to small changes in symmetry. We compare graphene samples that are prepared using several methods, including cleaving from parent materials such as highly ordered pyrolytic graphite, as well as sonication-assisted solution-phase exfoliation of natural flake graphite powder. The films are then deposited onto Si/SiO2 substrates for infrared measurements. This work is supported by the NSF-CAREER-DMR0449899, also GS and SB thank the UB-IRDF for financial support.

  8. Bioconversion reactor

    Science.gov (United States)

    McCarty, Perry L.; Bachmann, Andre

    1992-01-01

    A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

  9. Library rooms or Library halls

    Directory of Open Access Journals (Sweden)

    Alfredo Serrai

    2013-12-01

    Full Text Available Library Halls, understood as Renaissance and Baroque architectural creations, along with the furnishings and decorations, accomplish a cognitive task and serve to transmit knowledge. The design of these spaces based on the idea that they should reflect the merits and content of the collections housed within them, in order to prepare the mind of the reader to respect and admire the volumes. In accordance with this principle, in the fifteenth century library rooms had a basilican shape, with two or three naves, like churches, reflecting thus the spiritual value of the books contained there. Next to that inspiring function, library rooms had also the task of representing the entire logical and conceptual universe of human knowledge in a figurative way, including for this purpose also the and Kunst- und Wunderkammern, namely the collections of natural, artficial objects, and works of art. The importance of library rooms and their function was understood already in the early decades of the seventeenth century, as underlined in the treatise, Musei sive Bibliothecae tam privatae quam publicae Extructio, Instructio, Cura, Usus, written by the Jesuit Claude Clément and published in 1635. Almost the entire volume is dedicated to the decoration and ornamentation of the Saloni, and the function of the library is identified exclusively with the preservation and decoration of the collection, neglecting more specifically bibliographic aspects or those connected to library science. The architectural structure of the Saloni was destined to change in relation to two factors, namely the form of books, and the sources of light. As a consequence, from the end of the sixteenth century – or perhaps even before if one considers the fragments of the Library of Urbino belonging to Federico da Montefeltro – shelves and cabinets have been placed no longer in the center of the room, but were set against the walls. This new disposition of the furniture, surmounted by

  10. Training Top 10 Hall of Fame

    Science.gov (United States)

    Training, 2012

    2012-01-01

    Microsoft Corporation and SCC Soft Computer are the newest inductees into the Training Top 10 Hall of Fame, joining the ranks of the 11 companies named to the hall since its inception in 2008 (Wyeth Pharmaceuticals subsequently was acquired by Pfizer Inc. in 2009). These 11 companies held Top 10 spots in the Training Top 50, Top 100, and now Top…

  11. 20th Annual Residence Hall Construction Report

    Science.gov (United States)

    Agron, Joe

    2009-01-01

    Even in difficult economic times, colleges and universities continue to invest in residence hall construction projects as a way to attract new students and keep existing ones on campus. According to data from "American School & University"'s 20th annual Residence Hall Construction Report, the median new project completed in 2008 was…

  12. 19th Annual Residence Hall Construction Report

    Science.gov (United States)

    Agron, Joe

    2008-01-01

    The construction of residence hall facilities at colleges and universities continues to be strong, as institutions scramble to meet the housing needs and varied demands of a growing student population. This article presents data collected from 39 new residence hall projects completed in 2007. According to American School & University's 19th…

  13. Hall effect accompanying a static skin effect

    Energy Technology Data Exchange (ETDEWEB)

    Volkenshtein, N.V.; Marchenkov, V.V.; Startsev, V.E.; Cherepanov, A.N.; Glin' skii, M.

    1985-05-10

    The Hall effect and the magnetoresistance of tungsten single crystals with rho/sub 293K//rho/sub 4.2K/ = 80 000 have been measured at 4.2 K in magnetic fields up to 150 kOe. The results reveal that a static skin effect gives rise to an anomalously pronounced increase in the Hall coefficient.

  14. Acoustical parameters in concert hall acoustics

    Institute of Scientific and Technical Information of China (English)

    LIU Ke; ZHOU Qijun

    2003-01-01

    Professor Beranek talked about the sound qualities of concert hall. The 58 famousconcert halls in the world were graded according to the subjective comparison from the profes-sional musicians and music lovers. Six measurable objective parameters were proposed. Theranking according to these parameters were presented.

  15. The Scientific Humanism of G. Stanley Hall

    Science.gov (United States)

    Meyer, Donald H.

    1971-01-01

    This paper presents the humanistic psychology of the pioneer American psychologist Granville Stanley Hall (1844-1924), examining Hall's effort to develop a system of psychology that is at once rigorously scientific and, simultaneously, capable of verifying essential human values. (Author)

  16. Star Formation and the Hall Effect

    CERN Document Server

    Braiding, Catherine

    2011-01-01

    Magnetic fields play an important role in star formation by regulating the removal of angular momentum from collapsing molecular cloud cores. Hall diffusion is known to be important to the magnetic field behaviour at many of the intermediate densities and field strengths encountered during the gravitational collapse of molecular cloud cores into protostars, and yet its role in the star formation process is not well-studied. This thesis describes a semianalytic self-similar model of the collapse of rotating isothermal molecular cloud cores with both Hall and ambipolar diffusion, presenting similarity solutions that demonstrate that the Hall effect has a profound influence on the dynamics of collapse. ... Hall diffusion also determines the strength of the magnetic diffusion and centrifugal shocks that bound the pseudo and rotationally-supported discs, and can introduce subshocks that further slow accretion onto the protostar. In cores that are not initially rotating Hall diffusion can even induce rotation, whic...

  17. Espectáculo y construcción espacial en los autos de Pedro Calderón de la Barca: «La cena del rey Baltasar»

    Directory of Open Access Journals (Sweden)

    Antonio Sánchez Jiménez

    2013-11-01

    Full Text Available Este artículo analiza la construcción espectacular y espacial de un auto temprano de Calderón de la Barca, «La cena del rey Baltasar». Para ello, examina cómo funcionaban en este auto los elementos escénicos (carros, tramoya y atrezzo, así como la música, el vestuario y los espacios escénico y dramático. This article analyzes the spectacular and spacial construction of an early auto sacramental by Calderón de la Barca, «La cena del rey Baltasar». In order to do so, we examine the meaning of the different scenic elements (carros, theatrical machinery, and atrezzo, as well as the music, clothing, and scenic and dramatic spaces.

  18. Sonochemical Reactors.

    Science.gov (United States)

    Gogate, Parag R; Patil, Pankaj N

    2016-10-01

    Sonochemical reactors are based on the generation of cavitational events using ultrasound and offer immense potential for the intensification of physical and chemical processing applications. The present work presents a critical analysis of the underlying mechanisms for intensification, available reactor configurations and overview of the different applications exploited successfully, though mostly at laboratory scales. Guidelines have also been presented for optimum selection of the important operating parameters (frequency and intensity of irradiation, temperature and liquid physicochemical properties) as well as the geometric parameters (type of reactor configuration and the number/position of the transducers) so as to maximize the process intensification benefits. The key areas for future work so as to transform the successful technique at laboratory/pilot scale into commercial technology have also been discussed. Overall, it has been established that there is immense potential for sonochemical reactors for process intensification leading to greener processing and economic benefits. Combined efforts from a wide range of disciplines such as material science, physics, chemistry and chemical engineers are required to harness the benefits at commercial scale operation.

  19. Measurements of Plasma Potential Distribution in Segmented Electrode Hall Thruster

    Energy Technology Data Exchange (ETDEWEB)

    Y. Raitses; D. Staack; N.J. Fisch

    2001-10-16

    Use of a segmented electrode placed at the Hall thruster exit can substantially reduce the voltage potential drop in the fringing magnetic field outside the thruster channel. In this paper, we investigate the dependence of this effect on thruster operating conditions and segmented electrode configuration. A fast movable emissive probe is used to measure plasma potential in a 1 kW laboratory Hall thruster with semented electrodes made of a graphite material. Relatively small probe-induced perturbations of the thruster discharge in the vicinity of the thruster exit allow a reasonable comparison of the measured results for different thruster configurations. It is shown that the plasma potential distribution is almost not sensitive to changes of the electrode potential, but depends on the magnetic field distribution and the electrode placement.

  20. Stuart Hall: An Organic Intellectual

    Directory of Open Access Journals (Sweden)

    Johanna Fernández Castro

    2017-01-01

    Full Text Available Stuart Hall (3 February 1932 – 10 February 2014 is acknowledged as one of the founding figures of British Cultural Studies. His extensive academic work on topics such as race, ethnicity and identity reflects his own position as a diasporic intellectual. His contribution to the study of popular culture is determined by the importance of his political character in every social act, his non-deterministic view of Marxism, and is especially determined by his insistence on playing an active role beyond academia in order to contribute to the transformation of hegemonic structures. The following biography aims to give a focused view of his personal history and its direct influence on his key theoretical reflections.

  1. Optical Hall effect in strained graphene

    Science.gov (United States)

    Nguyen, V. Hung; Lherbier, A.; Charlier, J.-C.

    2017-06-01

    When passing an optical medium in the presence of a magnetic field, the polarization of light can be rotated either when reflected at the surface (Kerr effect) or when transmitted through the material (Faraday rotation). This phenomenon is a direct consequence of the optical Hall effect arising from the light-charge carrier interaction in solid state systems subjected to an external magnetic field, in analogy with the conventional Hall effect. The optical Hall effect has been explored in many thin films and also more recently in 2D layered materials. Here, an alternative approach based on strain engineering is proposed to achieve an optical Hall conductivity in graphene without magnetic field. Indeed, strain induces lattice symmetry breaking and hence can result in a finite optical Hall conductivity. First-principles calculations also predict this strain-induced optical Hall effect in other 2D materials. Combining with the possibility of tuning the light energy and polarization, the strain amplitude and direction, and the nature of the optical medium, large ranges of positive and negative optical Hall conductivities are predicted, thus opening the way to use these atomistic thin materials in novel specific opto-electro-mechanical devices.

  2. Timectomía por miastenia gravis en el Hospital Dr. Rafael Angel Calderón Guardia: Reporte de 24 casos

    Directory of Open Access Journals (Sweden)

    José A Mainieri Hidalgo

    2000-06-01

    Full Text Available Antecedentes: La miastenia gravis es una enfermedad autoinmune cuya etiología aún no está claramente definida. Desde 1912 se describió mejoría del cuadro posterior a timectomía. Este procedimiento es actualmente una de las formas aceptadas para su tratamiento. El objetivo del presente trabajo fue estudiar los resultados de la timectomía para el tratamiento de la miastenia gravis en el Hospital Rafael Angel Calderón Guardia. Materiales y Métodos: Estudio retrospectivo, basado en la revisión de los expedientes de 24 pacientes, a quienes se les realizó timectomía como parte de su tratamiento de miastenia gravis entre enero de 1992 y mayo de 1999, en el Hospital Dr. Rafael Angel Calderón Guardia. Resultados: Se encontró que un 75% de los pacientes presentaron una franca mejoría, 17% permaneció en igual condición y un 8% empeoró. No se observó diferencia en la evolución por sexo, edad o la presencia de timoma, sin embargo en los pacientes que presentaban únicamente síntomas oculares se dio una tendencia a persistir sintomáticos. Se observó que la preparación pre-operatoria del paciente con gamaglobulina y la modernización de la técnica anestésica disminuyó notablemente la necesidad de ventilación mecánica. Conclusión: La timectomía fue útil en el tratamiento del 75% de los pacientes, especialmente aquellos con no sólo ptosis palpebral y permitió disminuir la dosis de medicamentos en 12 de los 24 casos estudiados.Background: Miastenia gravis is an autoimmune disease, its etiology has not been defined clearly. The improvement of the clinical manifestations after thymectomy was first describes in 1912; and this procedure has become in one of the therapeutic alternativas for the disease nowadays. The aim of the present study was to investigase the results of thymectomy for miastenia gravis in the Hospital Dr. R. A. Calderón Guardia. Materials and Methods: Retrospective study, based in the revision of the clinical

  3. Vigilancia epidemiológica para el infarto agudo al miocardio, experiencia obtenida en el Hospital Calderón Guardia

    Directory of Open Access Journals (Sweden)

    Manrique leal-Mateos

    2005-04-01

    Full Text Available Justificación y objetivo: Debido a que el infarto agudo al miocardio representa una de las principales causas de muerte en nuestro país, la autoridades de salud decidieron, en 2003, incluirlo como una enfermedad sujeta a vigilancia epidemiológica. El presente trabajo tiene como propósito dar a conocer la información más sobresaliente del sistema de vigilancia epidemiológica para el IAM, implementado en el servicio de Medicina Interna del Hospital Calderón Guardia. Metodología: Se realizó un análisis descriptivo de la información recolectada desde el 1 de octubre de 2003, al 30 de septiembre de 2004. Las variables cualitativas se analizaron mediante frecuencias y proporciones. Las variables cuantitativas se expresaron por medio de medidas de tendencia central y dispersión. Las diferencias entre promedios y proporciones se compararon mediante la prueba de t Student. La significancia estadística fue fijada en p Rationale and Objective: Since acute myocardial infarction represents one of the main causes of death in our country, the health authorities decided in the year 2003 to include it as an illness subject to epidemiological surveillance. The present paper has as its purpose to give the most salient information of the epidemiological surveillance system for myocardial infarction implemented in the Internal Medicine service of the Calderón Guardia hospital. Methods: We did a descriptive analysis of the information collected since October First, 2003 and until September the 30th., 2004. Qualitative variables were analyzed with frequencies and proportions. The quantitative variables were expressed by means of measures of central tendency as well as measures of dispersion. The differences between averages and proportions were compared with the Student's t test. Statistical significance was fixed at less or equal to 0.05. We used the Epi Info program for data processing. Results: The age average was 64.6 years (S.D. + 12.2 years. 66

  4. The quantum Hall effects: Philosophical approach

    Science.gov (United States)

    Lederer, P.

    2015-05-01

    The Quantum Hall Effects offer a rich variety of theoretical and experimental advances. They provide interesting insights on such topics as gauge invariance, strong interactions in Condensed Matter physics, emergence of new paradigms. This paper focuses on some related philosophical questions. Various brands of positivism or agnosticism are confronted with the physics of the Quantum Hall Effects. Hacking's views on Scientific Realism, Chalmers' on Non-Figurative Realism are discussed. It is argued that the difficulties with those versions of realism may be resolved within a dialectical materialist approach. The latter is argued to provide a rational approach to the phenomena, theory and ontology of the Quantum Hall Effects.

  5. Quantum Hall Effect in Higher Dimensions

    CERN Document Server

    Karabali, Dimitra; Karabali, Dimitra

    2002-01-01

    Following recent work on the quantum Hall effect on $S^4$, we solve the Landau problem on the complex projective spaces ${\\bf C}P^k$ and discuss quantum Hall states for such spaces. Unlike the case of $S^4$, a finite spatial density can be obtained with a finite number of internal states for each particle. We treat the case of ${\\bf C}P^2$ in some detail considering both Abelian and nonabelian background fields. The wavefunctions are obtained and incompressibility of the Hall states is shown. The case of ${\\bf C}P^3$ is related to the case of $S^4$.

  6. Joule heating in spin Hall geometry

    Science.gov (United States)

    Taniguchi, Tomohiro

    2016-07-01

    The theoretical formula for the entropy production rate in the presence of spin current is derived using the spin-dependent transport equation and thermodynamics. This theory is applicable regardless of the source of the spin current, for example, an electric field, a temperature gradient, or the Hall effect. It reproduces the result in a previous work on the dissipation formula when the relaxation time approximation is applied to the spin relaxation rate. By using the developed theory, it is found that the dissipation in the spin Hall geometry has a contribution proportional to the square of the spin Hall angle.

  7. Piezo Voltage Controlled Planar Hall Effect Devices

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K. W.; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  8. Piezo Voltage Controlled Planar Hall Effect Devices.

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-22

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  9. Surface activity distribution measurements and establishment of a dose rate map inside the destroyed Chernobyl reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chesnokov, A.V.; Fedin, V.I.; Gulyaev, A.A. [RECOM Ltd., Moscow (Russian Federation)] [and others

    1999-02-01

    A Gamma Locator designed for contamination survey inside the reactor hall of the 4th unit of Chernobyl NNP has been developed. The device consists of a detector head and a remote control computer connected by a 150 m long cable. The detector head (dimensions: 500 mm by 500 mm by 400 mm; weight: about 40 kg) is a collimated scintillation gamma detector (the collimation angle is 10 deg.). It is installed on a scanning unit and was placed inside the reactor hall. The Gamma Locator scans all surfaces of the reactor hall with angular steps ({<=} 1 deg. vertically as well as horizontally) and the particle fluence from the corresponding direction is recorded. The distance between the device head and the measured surface is instantaneously registered by a laser distance gauge. Inside the collimator there is a small CCD camera which makes it possible to obtain a visible image of the measured surface. The effective surface activity levels are presented in colour on the screen of the control computer. The gamma detector essentially consists of a CsI(TI) scintillator crystal ({phi} 8 mm in diameter, 2.5 mm in thickness) and a Si photodiode. The detector energy resolution is about 8% for radiation from {sup 137}Cs. The exposure dose rate distribution in the reactor hall is estimated from the measured effective surface activities ({sup 137}Cs is the main gamma emitting isotope inside the reactor hall). The results of dose rate calculations are presented in colour superposed on a drawing of the reactor hall. (au) 1 tab., 28 ills., 16 refs.

  10. Neutron beam facilities at the Australian Replacement Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Shane; Robinson, Robert; Hunter, Brett [Physics Division, ANSTO, Lucas Heights (Australia)

    2001-03-01

    Australia is building a research reactor to replace the HIFAR reactor at Lucas Heights by the end of 2005. Like HIFAR, the Replacement Research Reactor will be multipurpose with capabilities for both neutron beam research and radioisotope production. It will be a pool-type reactor with thermal neutron flux (unperturbed) of 4 x 10{sup 14} n/cm{sup 2}/sec and a liquid D{sub 2} cold neutron source. Cold and thermal neutron beams for neutron beam research will be provided at the reactor face and in a large neutron guide hall. Supermirror neutron guides will transport cold and thermal neutrons to the guide hall. The reactor and the associated infrastructure, with the exception of the neutron beam instruments, is to be built by INVAP S.E. under contract. The neutron beam instruments will be developed by ANSTO, in consultation with the Australian user community. This status report includes a review the planned scientific capabilities, a description of the facility and a summary of progress to date. (author)

  11. La sublevación de Cataluña de 1640 en Los agravios satisfechos, apócrifo de Calderón de la Barca

    Directory of Open Access Journals (Sweden)

    Deias, Antonia

    2016-06-01

    Full Text Available This essay analyses Los agravios satisfechos y vísperas sicilianas, an apocryphal comedy by Calderón de la Barca, whose subject is the anti-French rebellion that took place at Palermo in 1282. The comparison between the literary text and some historical studies has allowed the identification of possible sources used by the author. On the other hand, the manipulation of History, in addition to the anachronisms related to some events of the third and fourth decade of the XVII century (France’s declaration of war on Spain in 1635, 1640 Catalan revolt and the Pact of Ceret, 1641 conspiracy in Andalusia, led us to establish the date of the Golden Age comedy and to identify the goals pursued by the playwright: to turn the Sicilian Vespers into a foundation myth of the Monarchy in Spain, using them as an anti-French symbol and, at the same time, to criticize the «restoring reformism» that the Count-Duke Olivares undertook.El trabajo analiza Los agravios satisfechos y vísperas cicilianas, comedia apócrifa de Calderón que trata del levantamiento antifrancés acontecido en Palermo en 1282. El cotejo del texto con algunas obras historiográficas ha permitido identificar las posibles fuentes utilizadas por el autor. Por otro lado, la manipulación de los hechos históricos, junto con los anacronismos que remiten a acontecimientos de los años treinta y cuarenta del siglo XVII (la declaración de guerra de Francia a España de 1635, la rebelión de Cataluña y el Pacto de Ceret de 1640, la conspiración de 1641 para levantar a Andalucía, han permitido establecer la datación de la obra e identificar los objetivos perseguidos por el autor: hacer de las Vísperas sicilianas un mito fundador de la monarquía española, utilizándolas en clave anti-francesa y, al mismo tiempo, criticar el «reformismo restaurador» del conde-duque de Olivares.

  12. The fluctuation Hall conductivity and the Hall angle in type-II superconductor under magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Tinh, Bui Duc, E-mail: tinhbd@hnue.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Hoc, Nguyen Quang; Thu, Le Minh [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam)

    2016-02-15

    Highlights: • The time-dependent Ginzburg–Landau was used to calculate fluctuation Hall conductivity and Hall angle in type-II superconductor in 2D and 3D. • We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. • The results were compared to the experimental data on YBCO. - Abstract: The fluctuation Hall conductivity and the Hall angle, describing the Hall effect, are calculated for arbitrary value of the imaginary part of the relaxation time in the frame of the time-dependent Ginzburg–Landau theory in type II-superconductor with thermal noise describing strong thermal fluctuations. The self-consistent Gaussian approximation is used to treat the nonlinear interaction term in dynamics. We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. The results are compared with experimental data on high-T{sub c} superconductor.

  13. Light Metal Propellant Hall Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek proposes to develop light metal Hall Effect thrusters that will help reduce the travel time, mass, and cost of SMD spacecraft. Busek has identified three...

  14. Success of Hall technique crowns questioned.

    Science.gov (United States)

    Nainar, S M Hashim

    2012-01-01

    Hall technique is a method of providing stainless steel crowns for primary molars without tooth preparation and requires no local anesthesia. Literature review showed inconclusive evidence and therefore this technique should not be used in clinical practice.

  15. Dual Mode Low Power Hall Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Sample and return missions desire and missions like Saturn Observer require a low power Hall thruster that can operate at high thrust to power as well as high...

  16. Iodine Hall Thruster for Space Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek Co. Inc. proposes to develop a high power (high thrust) electric propulsion system featuring an iodine fueled Hall Effect Thruster (HET). The system to be...

  17. The phonon Hall effect: theory and application

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lifa; Wang Jiansheng; Li Baowen [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); Ren Jie [NUS Graduate School for Integrative Sciences and Engineering, Singapore 117456 (Singapore)

    2011-08-03

    We present a systematic theory of the phonon Hall effect in a ballistic crystal lattice system, and apply it on the kagome lattice which is ubiquitous in various real materials. By proposing a proper second quantization for the non-Hermitian in the polarization-vector space, we obtain a new heat current density operator with two separate contributions: the normal velocity responsible for the longitudinal phonon transport, and the anomalous velocity manifesting itself as the Hall effect of transverse phonon transport. As exemplified in kagome lattices, our theory predicts that the direction of Hall conductivity at low magnetic field can be reversed by tuning the temperatures, which we hope can be verified by experiments in the future. Three phonon-Hall-conductivity singularities induced by phonon-band-topology change are discovered as well, which correspond to the degeneracies at three different symmetric center points, {Gamma}, K, X, in the wavevector space of the kagome lattice.

  18. Students halls – humane lifestyle for students

    Directory of Open Access Journals (Sweden)

    Igor Seljak

    2000-01-01

    Full Text Available With the increasing number of students at the University of Ljubljana (Slovenia, the shortage of student’s accommodation in student’s halls has increased. Alongside the necessity for building new accommodation capacities an opportunity has emerged for the enforcement of new living standards that should replace outdated guidelines from the sixties. During the preparation of the project we analysed all the important elements of students accommodation in students halls. Analyses of the present conditions in existing halls were performed, including positive and negative elements. We also conducted a comparative research of student’s halls in various European countries. In conclusion a list of recommendations with real guidelines was prepared that could be used by investors when proposing new development of such buildings, as well as architects and planners.

  19. Athletics hall, Odenwald school, Heppenheim, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Schuler, M. [Trans Solar GmbH, Stuttgart (Germany)

    1999-07-01

    This building, completed in 1995, is a good example of how to use a glazed foyer, not only as a climatic buffer zone, but also for preheating the inlet air by solar gains. The completely glazed west-oriented foyer is used as a huge air collector to preheat ventilation air during the heating period. The glass superstructure across the hall stores a movable curtain, serves as a skylight and enhances the natural ventilation of the hall due to the chimney effect. The stiffening ribs of the floor are also used as an air duct to the hall and as an installation duct. Photovoltaic-powered fans are used to move solar preheated air into the hall. (author)

  20. Quantum Hall effect in momentum space

    Science.gov (United States)

    Ozawa, Tomoki; Price, Hannah M.; Carusotto, Iacopo

    2016-05-01

    We theoretically discuss a momentum-space analog of the quantum Hall effect, which could be observed in topologically nontrivial lattice models subject to an external harmonic trapping potential. In our proposal, the Niu-Thouless-Wu formulation of the quantum Hall effect on a torus is realized in the toroidally shaped Brillouin zone. In this analogy, the position of the trap center in real space controls the magnetic fluxes that are inserted through the holes of the torus in momentum space. We illustrate the momentum-space quantum Hall effect with the noninteracting trapped Harper-Hofstadter model, for which we numerically demonstrate how this effect manifests itself in experimental observables. Extension to the interacting trapped Harper-Hofstadter model is also briefly considered. We finally discuss possible experimental platforms where our proposal for the momentum-space quantum Hall effect could be realized.

  1. Multiscale Modeling of Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — New multiscale modeling capability for analyzing advanced Hall thrusters is proposed. This technology offers NASA the ability to reduce development effort of new...

  2. Observation of the magnon Hall effect.

    Science.gov (United States)

    Onose, Y; Ideue, T; Katsura, H; Shiomi, Y; Nagaosa, N; Tokura, Y

    2010-07-16

    The Hall effect usually occurs in conductors when the Lorentz force acts on a charge current in the presence of a perpendicular magnetic field. Neutral quasi-particles such as phonons and spins can, however, carry heat current and potentially exhibit the thermal Hall effect without resorting to the Lorentz force. We report experimental evidence for the anomalous thermal Hall effect caused by spin excitations (magnons) in an insulating ferromagnet with a pyrochlore lattice structure. Our theoretical analysis indicates that the propagation of the spin waves is influenced by the Dzyaloshinskii-Moriya spin-orbit interaction, which plays the role of the vector potential, much as in the intrinsic anomalous Hall effect in metallic ferromagnets.

  3. Hall effect degradation of rail gun performance

    Science.gov (United States)

    Witalis, E. A.; Gunnarsson, Patrik

    1993-01-01

    The paper discusses the Hall effect and shows it to be significant in the low-density and high-field trailing part of a plasma armature. Without the Hall effect a simple armature model is derived. It exhibits properties expected from classical MHD theory and shows that the purely relativistic electric charge buildup on the rails is a fundamental gun property, leading to V(breech) = 1.5 V(muzzle). The mathematics involved in accounting for Hall effect phenomena is described. These are of two types: the Hall-skewing of the armature current and the superimposed plasma flow rotation. For decreasing gun current the two effects efficiently combine to eject armature plasma rearwards, thus creating conditions for arc separation and parasitic arcs.

  4. Iodine Hall Thruster for Space Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In the Phase I program, Busek Co. Inc. tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high flow iodine feed system,...

  5. Evaluation of stage acoustics in Seoul Arts Center Concert Hall by measuring stage support.

    Science.gov (United States)

    Jeon, Jin Yong; Barron, Michael

    2005-01-01

    Stage acoustics is an important characteristic for concert halls, both for the acoustic quality on stage and for the audience. However, relatively little research has been conducted into the question. This study was based on the investigation of an actual concert hall stage, that of the Seoul Arts Center Concert Hall in Korea. The stage acoustics was evaluated in the actual hall, and with two models: a 1:25 scale model and a computer model. The study was based on the stage support parameter ST1 proposed by Gade as a measure of support for individual performers [Acustica 65, 193-203 (1989)]. The variation of support was measured on the empty stage of the actual hall and in the two models. The effect of musicians on stage, the effect of moving the orchestra, the effect of ceiling height and of stage-wall profile were also investigated. Conclusions are drawn both relating to the Seoul Concert Hall stage and stages in general.

  6. 75 FR 7467 - Gary E. Hall and Rita C. Hall; Notice of Application Accepted for Filing With the Commision...

    Science.gov (United States)

    2010-02-19

    .... Applicant: Gary E. Hall and Rita C. Hall. e. Name of Project: Potter Creek Hydroelectric Project. f. Location: The project is located on Potter Creek in Flathead County, Montana. The project would be located...: Mr. Gary E. Hall and Ms. Rita C. Hall, P.O. Box 133, Olney, MT 59927, (406) 881-2345. i. FERC Contact...

  7. High temperature hall effect measurement system design, measurement and analysis

    Science.gov (United States)

    Berkun, Isil

    A reliable knowledge of the transport properties of semiconductor materials is essential for the development and understanding of a number of electronic devices. In this thesis, the work on developing a Hall Effect measurement system with software based data acqui- sition and control for a temperature range of 300K-700K will be described. A system was developed for high temperature measurements of materials including single crystal diamond, poly-crystalline diamond, and thermoelectric compounds. An added capability for monitor- ing the current versus voltage behavior of the contacts was used for studying the influence of ohmic and non-ohmic contacts on Hall Effect measurements. The system has been primar- ily used for testing the transport properties of boron-doped single crystal diamond (SCD) deposited in a microwave plasma-assisted chemical vapor deposition (MPCVD) reactor [1]. Diamond has several outstanding properties that are of high interest for its development as an electronic material. These include a relatively wide band gap of 5.5 (eV), high thermal conductivity, high mobility, high saturation velocity, and a high breakdown voltage. For a temperature range of 300K-700K, IV curves, Hall mobilities and carrier concentrations are shown. Temperature dependent Hall effect measurements have shown carrier concentrations from below 1017cm --3 to approximately 1021 cm--3 with mobilities ranging from 763( cm2/V s) to 0.15(cm 2/V s) respectively. Simulation results have shown the effects of single and mixed carrier models, activation energies, effective mass and doping concentrations. These studies have been helpful in the development of single crystal diamond for diode applications. Reference materials of Ge and GaAs were used to test the Hall Effect system. The system was also used to characterize polycrystalline diamond deposited on glass for electrochemical applications, and Mg2(Si,Sn) compounds which are promising candidates of low-cost, light weight and non

  8. Reseción esofágica por cáncer, experiencia del Servicio de Cirugía de Tórax del Hospital Dr. Rafael Á. Calderón Guardia

    Directory of Open Access Journals (Sweden)

    José Alberto Mainieri-Hidalgo

    2007-10-01

    Full Text Available Durante el período comprendido entre 1990 y 2006, 28 pacientes fueron sometidos a resección esofágica por cáncer en el Servicio de Cirugía de Tórax del Hospital Dr. Rafael Á. Calderón Guardia. La edad promedio fue de 65 años y la relación hombre mujer, de 6 a 1. El antecedente de tabaquismo se confirmó en un 80%, etilismo en un 75% y 8 pacientes eran conocidos portadores de esófago de Barret. Disfagia, dolor epigástrico y pérdida de peso fueron los síntomas más frecuentes; siendo la epigastralgia debida a otra patología digestiva coexistente, como reflujo o enfermedad péptica. Los pacientes clasificados como estadio IIb, III y IV recibieron terapia de inducción y aunque en 3 de estos no se encontró tumor residual en la pieza quirúrgica, en 2 casos quedó tumor adherido a la aorta. A 21 pacientes se les realizó esofagectomía total con ascenso gástrico y anastomosis cervical y a 7 esofagectomía parcial con ascenso gástrico al tórax en 5 y 2 esófago-yeyuno anastomosis, una intratorácica y otra abdominal. La complicación más frecuente fue la claudicación respiratoria por bronconeumonía, que se produjo en 7 pacientes y que fue mortal en 3. Dos de estos pacientes presentaron además fuga de anastomosis, una en el cuello y otra en el tórax. A largo plazo la complicación más frecuente fue estrechez de la anastomosis, que en los 7 casos se ha manejado con dilataciones. La mortalidad quirúrgica fue del 10.7% y en los 3 casos la bronconeumonía fue la causa principal. La supervivencia a 5 y 10 años fue del 31.5% y el 18%, respectivamente.

  9. Cohomological Hall algebras and character varieties

    CERN Document Server

    Davison, Ben

    2015-01-01

    In this paper we investigate the relationship between twisted and untwisted character varieties via a specific instance of the Cohomological Hall algebra for moduli of objects in 3-Calabi-Yau categories introduced by Kontsevich and Soibelman. In terms of Donaldson--Thomas theory, this relationship is completely understood via the calculations of Hausel and Villegas of the E polynomials of twisted character varieties and untwisted character stacks. We present a conjectural lift of this relationship to the cohomological Hall algebra setting.

  10. Hall effect on the triangular lattice

    OpenAIRE

    Leon Suros, Gladys Eliana; Berthod, Christophe; Giamarchi, Thierry; Millis, A.

    2008-01-01

    We investigate the high frequency Hall effect on a two-dimensional triangular lattice with nearest-neighbor hopping and a local Hubbard interaction. The complete temperature and doping dependencies of the high-frequency Hall coefficient $R_H$ are evaluated analytically and numerically for small, intermediate, and strong interactions using various approximation schemes. We find that $R_H$ follows the semiclassical $1/qn^*$ law near T=0, but exhibits a striking $T$-linear behavior with an inter...

  11. Are tent halls subject to property tax?

    Directory of Open Access Journals (Sweden)

    Mariusz Macudziński

    2016-12-01

    Full Text Available The presented publication is a response to currently asked questions and interpretative doubts of taxpayers and tax authorities, namely whether tent halls are subject to property tax. General issues connected with an entity and a subject of taxation of this tax are presented herein. The answer to the question asked is then provided through the qualification of constructions works and the allocation of tent halls in the proper category of the works, with the use of the current law.

  12. Piezo Voltage Controlled Planar Hall Effect Devices

    OpenAIRE

    Bao Zhang; Kang-Kang Meng; Mei-Yin Yang; Edmonds, K. W.; Hao Zhang; Kai-Ming Cai; Yu Sheng; Nan Zhang; Yang Ji; Jian-Hua Zhao; Hou-Zhi Zheng; Kai-You Wang

    2015-01-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the pie...

  13. Hall effect in organic layered conductors

    Directory of Open Access Journals (Sweden)

    R.A.Hasan

    2006-01-01

    Full Text Available The Hall effect in organic layered conductors with a multisheeted Fermi surfaces was considered. It is shown that the experimental study of Hall effect and magnetoresistance anisotropy at different orientations of current and a quantizing magnetic field relative to the layers makes it possible to determine the contribution of various charge carriers groups to the conductivity, and to find out the character of Fermi surface anisotropy in the plane of layers.

  14. An introduction to motivic Hall algebras

    CERN Document Server

    Bridgeland, Tom

    2010-01-01

    We give an introduction to Joyce's construction of the motivic Hall algebra of coherent sheaves on a variety M. When M is a Calabi-Yau threefold we define a semi-classical integration map from a Poisson subalgebra of this Hall algebra to the ring of functions on a symplectic torus. This material will be used in arxiv:1002.4374 to prove some basic properties of Donaldson-Thomas curve-counting invariants on Calabi-Yau threefolds.

  15. Air leakage analysis of research reactor HANARO building in typhoon condition for the nuclear emergency preparedness

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Goany Up; Lee, Hae Cho; Kim, Bong Seok; Kim, Jong Soo; Choi, Pyung Kyu [Dept. of Emergency Preparedness, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-12-15

    To find out the leak characteristic of research reactor 'HANARO' building in a typhoon condition MELCOR code which normally is used to simulate severe accident behavior in a nuclear power plant was used to simulate the leak rate of air and fission products from reactor hall after the shutdown of the ventilation system of HANARO reactor building. For the simulation, HANARO building was designed by MELCOR code and typhoon condition passed through Daejeon in 2012 was applied. It was found that the leak rate is 0.1%·day{sup -1} of air, 0.004%·day{sup -1} of noble gas and 3.7×10{sup -5}%·day{sup -1} of aerosol during typhoon passing. The air leak rate of 0.1%·day can be converted into 1.36 m{sup 3}·hr{sup -1} , but the design leak rate in HANARO safety analysis report was considered as 600 m3·hr{sup -1} under the condition of 20 m·sec{sup -1} wind speed outside of the building by typhoon. Most of fission products during the maximum hypothesis accident at HANARO reactor will be contained in the reactor hall, so the direct radiation by remained fission products in the reactor hall will be the most important factor in designing emergency preparedness for HANARO reactor.

  16. Turbulence Measurements in a Tropical Zoo Hall

    Science.gov (United States)

    Eugster, Werner; Denzler, Basil; Bogdal, Christian

    2017-04-01

    The Masoala rainforest hall of the Zurich Zoo, Switzerland, covers a ground surface area of 10,856 m2 and reaches 30 m in height. With its transparent ETFE foiled roof it provides a tropical climate for a large diversity of plants and animals. In combination with an effort to estimate dry deposition of elemental mercury, we made an attempt to measure turbulent transfer velocity with an ultrasonic anemometer inside the hall. Not surprising, the largest turbulence elements were on the order of the hall dimension. Although the dimensions of the hall seem to be small (200,000 m3) for eddy covariance flux measurements and the air circulation inside the hall was extremely weak, the spectra of wind velocity components and virtual (sonic) temperature obeyed the general statistical description expected under unconstrained outdoor measurement conditions. We will present results from a two-week measurement campaign in the Masoala rainforest hall and make a suggestion for the deposition velocity to be used to estimate dry deposition of atmospheric components to the tropical vegetation surface.

  17. Assessment of torsatrons as reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, J.F. (Oak Ridge National Lab., TN (United States)); Painter, S.L. (Australian National Univ., Canberra, ACT (Australia))

    1992-12-01

    Stellarators have significant operational advantages over tokamaks as ignited steady-state reactors because stellarators have no dangerous disruptions and no need for continuous current drive or power recirculated to the plasma, both easing the first wall, blanket, and shield design; less severe constraints on the plasma parameters and profiles; and better access for maintenance. This study shows that a reactor based on the torsatron configuration (a stellarator variant) could also have up to double the mass utilization efficiency (MUE) and a significantly lower cost of electricity (COE) than a conventional tokamak reactor (ARIES-I) for a range of assumptions. Torsatron reactors can have much smaller coil systems than tokamak reactors because the coils are closer to the plasma and they have a smaller cross section (higher average current density because of the lower magnetic field). The reactor optimization approach and the costing and component models are those used in the current stage of the ARIES-I tokamak reactor study. Typical reactor parameters for a 1-GW(e) Compact Torsatron reactor example are major radius R[sub 0] = 6.6-8.8 m, on-axis magnetic field B[sup 0] = 4.8-7.5 T, B[sub max] (on coils) = 16 T, MUE 140-210 kW(e)/tonne, and COE (in constant 1990 dollars) = 67-79 mill/kW(e)h. The results are relatively sensitive to assumptions on the level of confinement improvement and the blanket thickness under the inboard half of the helical windings but relatively insensitive to other assumptions.

  18. 75 FR 22770 - Gary E. Hall and Rita Hall; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2010-04-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Gary E. Hall and Rita Hall; Notice of Availability of Environmental Assessment April 22, 2010. In accordance with the National Environmental Policy Act of 1969, as amended,...

  19. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  20. D and DR Reactors

    Data.gov (United States)

    Federal Laboratory Consortium — The world's second full-scale nuclear reactor was the D Reactor at Hanford which was built in the early 1940's and went operational in December of 1944.D Reactor ran...

  1. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  2. Charge carrier coherence and Hall effect in organic semiconductors.

    Science.gov (United States)

    Yi, H T; Gartstein, Y N; Podzorov, V

    2016-03-30

    Hall effect measurements are important for elucidating the fundamental charge transport mechanisms and intrinsic mobility in organic semiconductors. However, Hall effect studies frequently reveal an unconventional behavior that cannot be readily explained with the simple band-semiconductor Hall effect model. Here, we develop an analytical model of Hall effect in organic field-effect transistors in a regime of coexisting band and hopping carriers. The model, which is supported by the experiments, is based on a partial Hall voltage compensation effect, occurring because hopping carriers respond to the transverse Hall electric field and drift in the direction opposite to the Lorentz force acting on band carriers. We show that this can lead in particular to an underdeveloped Hall effect observed in organic semiconductors with substantial off-diagonal thermal disorder. Our model captures the main features of Hall effect in a variety of organic semiconductors and provides an analytical description of Hall mobility, carrier density and carrier coherence factor.

  3. Neutron scattering at Australia's replacement research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, S.J.; Robinson, R.A.; Hunter, B.A. [Physics Division, ANSTO, Lucas Heights, NSW (Australia)

    2001-03-01

    On August 25{sup th} 1999, the Australian government gave final approval to build a research reactor to replace the existing HIFAR reactor at Lucas Heights. The replacement reactor, which will commence operation in 2005, will be multipurpose with capabilities for both neutron beam research and radioisotope production. Cold, and thermal neutron sources are to be installed and supermirror guides will transport cold and thermal neutron beams into a large modern guide hall. The reactor and associated infrastructure is to be built by INVAP, SE and subcontractors under contract. The neutron beam instruments will be developed by ANSTO in consultation with the Australian user community and interested overseas parties. We review the planned scientific capabilities, give a description of the facility and a status report on the activities so far. (author)

  4. Edge reconstructions in fractional quantum Hall systems.

    Science.gov (United States)

    Joglekar, Yogesh; Nguyen, Hoang; Murthy, Ganpathy

    2003-03-01

    Two dimensional electron systems exhibiting fractional quantum Hall effects are characterized by a quantized Hall conductance and a dissipationless bulk. The transport in these systems occurs only at the edges where gapless excitations are possible [1]. We present a microscopic calculation of these egde-states at filling factors ν=1/3 and ν=2/5 using the Hamiltonian theory of the fractional quantum Hall effect [2]. We find that the quantum Hall egde undergoes a reconstruction as the confining potential, produced by the background charge density, softens [3,4]. Our results have implications to the tunneling experiments into the edge of a fractional quantum Hall system [5]. 1: X. G.Wen, Phys. Rev. Lett. 64, 2206 (1990). 2: R. Shankar and G. Murthy, Phys. Rev. Lett. 79, 4437 (1997). 3: C. de C. Chamon and X. G. Wen, Phys. Rev. B 49, 8227 (1994). 4: X. Wan, K. Yang, and E. H. Razayi, Phys. Rev. Lett. 88, 056802 (2002). 5: A.M.Chang et al., Phys. Rev. Lett. 86, 143 (2000).

  5. The Hall effect in star formation

    CERN Document Server

    Braiding, Catherine R

    2011-01-01

    Magnetic fields play an important role in star formation by regulating the removal of angular momentum from collapsing molecular cloud cores. Hall diffusion is known to be important to the magnetic field behaviour at many of the intermediate densities and field strengths encountered during the gravitational collapse of molecular cloud cores into protostars, and yet its role in the star formation process is not well-studied. We present a semianalytic self-similar model of the collapse of rotating isothermal molecular cloud cores with both Hall and ambipolar diffusion, and similarity solutions that demonstrate the profound influence of the Hall effect on the dynamics of collapse. The solutions show that the size and sign of the Hall parameter can change the size of the protostellar disc by up to an order of magnitude and the protostellar accretion rate by fifty per cent when the ratio of the Hall to ambipolar diffusivities is varied between -0.5 <= eta_H / eta_A <= 0.2. These changes depend upon the orien...

  6. Nuclear reactor neutron shielding

    Energy Technology Data Exchange (ETDEWEB)

    Speaker, Daniel P; Neeley, Gary W; Inman, James B

    2017-09-12

    A nuclear reactor includes a reactor pressure vessel and a nuclear reactor core comprising fissile material disposed in a lower portion of the reactor pressure vessel. The lower portion of the reactor pressure vessel is disposed in a reactor cavity. An annular neutron stop is located at an elevation above the uppermost elevation of the nuclear reactor core. The annular neutron stop comprises neutron absorbing material filling an annular gap between the reactor pressure vessel and the wall of the reactor cavity. The annular neutron stop may comprise an outer neutron stop ring attached to the wall of the reactor cavity, and an inner neutron stop ring attached to the reactor pressure vessel. An excore instrument guide tube penetrates through the annular neutron stop, and a neutron plug comprising neutron absorbing material is disposed in the tube at the penetration through the neutron stop.

  7. Reactor and method of operation

    Science.gov (United States)

    Wheeler, John A.

    1976-08-10

    A nuclear reactor having a flattened reactor activity curve across the reactor includes fuel extending over a lesser portion of the fuel channels in the central portion of the reactor than in the remainder of the reactor.

  8. Mesoscopic effects in the quantum Hall regime

    Indian Academy of Sciences (India)

    R N Bhatt; Xin Wan

    2002-02-01

    We report results of a study of (integer) quantum Hall transitions in a single or multiple Landau levels for non-interacting electrons in disordered two-dimensional systems, obtained by projecting a tight-binding Hamiltonian to the corresponding magnetic subbands. In finite-size systems, we find that mesoscopic effects often dominate, leading to apparent non-universal scaling behavior in higher Landau levels. This is because localization length, which grows exponentially with Landau level index, exceeds the system sizes amenable to the numerical study at present. When band mixing between multiple Landau levels is present, mesoscopic effects cause a crossover from a sequence of quantum Hall transitions for weak disorder to classical behavior for strong disorder. This behavior may be of relevance to experimentally observed transitions between quantum Hall states and the insulating phase at low magnetic fields.

  9. Quantized photonic spin Hall effect in graphene

    Science.gov (United States)

    Cai, Liang; Liu, Mengxia; Chen, Shizhen; Liu, Yachao; Shu, Weixing; Luo, Hailu; Wen, Shuangchun

    2017-01-01

    We examine the photonic spin Hall effect (SHE) in a graphene-substrate system with the presence of an external magnetic field. In the quantum Hall regime, we demonstrate that the in-plane and transverse spin-dependent splittings in the photonic SHE exhibit different quantized behaviors. The quantized SHE can be described as a consequence of a quantized geometric phase (Berry phase), which corresponds to the quantized spin-orbit interaction. Furthermore, an experimental scheme based on quantum weak value amplification is proposed to detect the quantized SHE in the terahertz frequency regime. By incorporating the quantum weak measurement techniques, the quantized photonic SHE holds great promise for detecting quantized Hall conductivity and the Berry phase. These results may bridge the gap between the electronic SHE and photonic SHE in graphene.

  10. Graphene-based Hall Sensors for direct magnetic imaging by using Scanning Hall Probe Microscope

    Science.gov (United States)

    Sonusen, Selda; Aksoy, Seda; Dede, Munir; Oral, Ahmet

    2013-03-01

    Graphene has been attracting great interest due to its unique electronic and mechanical properties for both fundamental and experimental studies since 2004. Graphene is a promising material for many applications in high speed electronic and spintronic devices as well as sensors. Its high mobility makes graphene a good candidate for magnetic imaging in Scanning Hall Probe Microscope (SHPM). Hall probes are used to scan the magnetic samples to image magnetic domains in SHPM. In this work, single layer graphene produced by chemical vapor deposition technique is used to fabricate Hall sensors by optical and the e-beam lithography with sizes from 500 nm to a few micrometers. The Hall crosses are characterized by Raman mapping to make sure that they are made of a single layer graphene. The Graphene Hall Sensors noise spectra is measured as a function of different bias currents and carrier concentrations at 300 K, 77 K and 4.24K. The imaging performance of the Hall sensor will be demonstrated at different temperatures by imaging a garnet crystal using a Low Temperature Scanning Hall Probe Microscope (LT-SHPM).

  11. Leiomioma esofágico: Experiencia con diez casos operados en el "Hospital Dr. Rafael Ángel Calderón Guardia"

    Directory of Open Access Journals (Sweden)

    Giovanna Mainieri-Breedy

    2012-09-01

    Full Text Available Objetivo: informar la experiencia adquirida con la cirugía para leiomiomas esofágicos en el Servicio de Cirugía de Tórax del Hospital Dr. R. A. Calderón Guardia. Métodos: durante el período de 12 años comprendido entre 1999 y 2011, fueron referidos 14 pacientes con tumores submucosos del esófago al Servicio de Cirugía de Tórax del Hospital Calderón Guardia. En cuatro pacientes asintomáticos con tumores pequeños se decidió observar, y diez fueron operados, confirmándose el diagnóstico histológico de leiomioma. Previa autorización del Comité de Ética del Hospital, se revisaron los expedientes clínicos, analizando las características personales, los síntomas, los métodos de diagnóstico, el tratamiento quirúrgico y la evolución de los pacientes operados. Resultados: se encontró que de los diez pacientes operados, ocho fueron varones, en edades entre los 38 y 71 años, con un promedio de 56 años. El síntoma principal fue disfagia, pero en 3 casos el tumor fue un hallazgo incidental de una endoscopia de rutina. El método de detección en todos los casos fue la endoscopia en la que se describió un tumor submucoso o una compresión extrínseca de la pared esofágica. El ultrasonido endoscópico se correlacionó con un tumor originado en la cuarta capa, posible leiomioma. En dos casos, debido a las dimensiones de la lesión, se planteó la posibilidad de malignidad. La tumoración se intervino en nueve casos por toracotomía y en uno, por laparotomía. En 7 casos se enucleó sin que se abriera la mucosa, en dos se realizó esofagectomía parcial con anastomosis y parche de diafragma, y en un caso, excepcional, la tumoración se extendía desde el esófago cervical hasta la unión esófago-gástrica, de manera que se realizó una esofagectomía total, con ascenso gástrico y anastomosis cervical. No hubo ningún caso de mortalidad. Un paciente presentó una pequeña fuga de la anastomosis, la cual resolvió espont

  12. EL CROWN HALL. CONTEXTO Y PROYECTO

    Directory of Open Access Journals (Sweden)

    Laura Lizondo Sevilla

    2010-05-01

    Full Text Available RESUMEN El artículo enmarca el edificio del Crown Hall en el contexto docente y arquitectónico de Mies van der Rohe. Revisa sus inicios en la Bauhaus con su primera intervención en un espacio docente para la Bauhaus de Berlín en 1932, así como su marcha a Estados Unidos, los planteamientos arquitectónicos del campus del IIT y el proyecto del Crown Hall. El texto incide en el estudio del proceso proyectual del Crown Hall analizando la evolución de su concepción arquitectónica a través de las diferentes versiones del proyecto. Se constata la transición desde los primeros planteamientos arquitectónicos de los edificios del campus del IIT proyectados por Mies hacia el planteamiento del gran espacio unitario del Crown Hall. Este proyecto se puede entender desde la creciente importancia de la estructura, la claridad constructiva y el manejo del acero y vidrio como únicos materiales de la imagen del edificio y el carácter flexible y unitario del espacio. Finalmente se hace referencia al concepto del "espacio universal" en la arquitectura de Mies, como un concepto abstracto que supera los de flexibilidad de uso o unidad espacial, insinuando, a modo de reflexión, las principales variables que definirían el espacio universal miesiano.SUMMARY The article showcases the Crown Hall building in the educational and architectural context of Mies van der Rohe. It reviews his beginnings in the Bauhaus with his first intervention in an educational space for the Bauhaus of Berlin in 1932, as well as his sojourn to the United States, and the architectural approaches to the IIT campus and the Crown Hall project. The text touches on the study of the planning process for the Crown Hall, analysing the evolution of its architectural conception, through the different versions of the project. The article covers the transition from the first architectural approaches for the IIT campus buildings, planned by Mies, to the approach of the large unitary space of

  13. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...... in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers. Correlations between the objective and subjective results lead, among others, to a recommendation for reverberation time as a function of hall volume. Since the bass...

  14. Inverse spin Hall effect by spin injection

    Science.gov (United States)

    Liu, S. Y.; Horing, Norman J. M.; Lei, X. L.

    2007-09-01

    Motivated by a recent experiment [S. O. Valenzuela and M. Tinkham, Nature (London) 442, 176 (2006)], the authors present a quantitative microscopic theory to investigate the inverse spin-Hall effect with spin injection into aluminum considering both intrinsic and extrinsic spin-orbit couplings using the orthogonalized-plane-wave method. Their theoretical results are in good agreement with the experimental data. It is also clear that the magnitude of the anomalous Hall resistivity is mainly due to contributions from extrinsic skew scattering.

  15. Integer quantum Hall effect in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Jellal, Ahmed, E-mail: ahmed.jellal@gmail.com [Saudi Center for Theoretical Physics, Dhahran (Saudi Arabia); Theoretical Physics Group, Faculty of Sciences, Chouaïb Doukkali University, 24000 El Jadida (Morocco)

    2016-04-08

    We study the quantum Hall effect in a monolayer graphene by using an approach based on thermodynamical properties. This can be done by considering a system of Dirac particles in an electromagnetic field and taking into account of the edges effect as a pseudo-potential varying continuously along the x direction. At low temperature and in the weak electric field limit, we explicitly determine the thermodynamical potential. With this, we derive the particle numbers in terms of the quantized flux and therefore the Hall conductivity immediately follows.

  16. Resultados obstétricos y neonatales de pacientes secundigestas con antecedente de cesárea, Hospital Dr. Rafael Ángel Calderón Guardia, 2006-2007

    OpenAIRE

    Manrique Leal-Mateos; Loretta Giacomin-Carmiol; Rafael Ángel Moya-Sibaja

    2010-01-01

    Objetivo: Analizar los resultados obstétricos y neonatales de pacientes con antecedente de cesárea. Materiales y Métodos: Se realizó un estudio observacional de corte transversal. Se analizaron 306 historias clínicas de pacientes gestantes atendidas en el servicio de Obstetricia del Hospital Dr. Rafael Ángel Calderón Guardia (HCG) del 1 de enero de 2006 al 31 de diciembre de 2007. Las variables maternas relacionadas con el control prenatal fueron edad e indicación obstétrica que motivó la ces...

  17. Neutron scattering at Australia's replacement research reactor

    Science.gov (United States)

    Robinson, R. A.; Kennedy, S. J.

    2002-01-01

    On August 25 1999, the Australian government gave final approval to build a research reactor to replace the existing HIFAR reactor at Lucas Heights. The replacement reactor, which will commence operation in 2005, will be multipurpose in function, with capabilities for both neutron-beam research and radioisotope production. Regarding beams, cold and thermal neutron sources are to be installed and the intent is to use supermirror guides, with coatings with critical angles up to 3 times that of natural Ni, to transport cold and thermal neutron beams into a large modern guide hall. The reactor and all the associated infrastructure, with the exception of the neutron beam instruments, is to be built by INVAP, SE and subcontractors in a turnkey contract. The goal is to have at least eight leading-edge neutron-beam instruments ready in 2005, and they will be developed by ANSTO and other contracted organisations, in consultation with the Australian user community and interested overseas parties. A review of the planned scientific capabilities, a description of the facility and a status report on the activities so far is given.

  18. Puddle-Induced Resistance Oscillations in the Breakdown of the Graphene Quantum Hall Effect

    Science.gov (United States)

    Yang, M.; Couturaud, O.; Desrat, W.; Consejo, C.; Kazazis, D.; Yakimova, R.; Syväjärvi, M.; Goiran, M.; Béard, J.; Frings, P.; Pierre, M.; Cresti, A.; Escoffier, W.; Jouault, B.

    2016-12-01

    We report on the stability of the quantum Hall plateau in wide Hall bars made from a chemically gated graphene film grown on SiC. The ν =2 quantized plateau appears from fields B ≃5 T and persists up to B ≃80 T . At high current density, in the breakdown regime, the longitudinal resistance oscillates with a 1 /B periodicity and an anomalous phase, which we relate to the presence of additional electron reservoirs. The high field experimental data suggest that these reservoirs induce a continuous increase of the carrier density up to the highest available magnetic field, thus enlarging the quantum plateaus. These in-plane inhomogeneities, in the form of high carrier density graphene pockets, modulate the quantum Hall effect breakdown and decrease the breakdown current.

  19. Destruction of the Fractional Quantum Hall Effect by Disorder

    Science.gov (United States)

    Laughlin, R. B.

    1985-07-01

    It is suggested that Hall steps in the fractional quantum Hall effect are physically similar to those in the ordinary quantum Hall effect. This proposition leads to a simple scaling diagram containing a new type of fixed point, which is identified with the destruction of the fractional states by disorder. 15 refs., 3 figs.

  20. Digital technology impacts on the Arnhem transfer hall structural design

    NARCIS (Netherlands)

    Van de Straat, R.; Hofman, S.; Coenders, J.L.; Paul, J.C.

    2015-01-01

    The new Transfer Hall in Arnhem is one of the key projects to prepare the Dutch railways for the increased future demands for capacity. UNStudio developed a master plan in 1996 for the station area of which the completion of the Transfer Hall in 2015 will be a final milestone. The Transfer Hall is a

  1. New type of magnetization equipment using a commercial Hall sensor

    Science.gov (United States)

    Nishioka, T.; Sato, N. K.

    2004-05-01

    We have developed a new method of the magnetization measurement using a commercial Hall sensor (Hall magnetometer), which enables us to measure the static magnetization very easily at temperatures as low as about 0.1 K and under pressure. We describe specifications of the Hall magnetometer, and show results of the magnetization measurement for UGe 2 as an example.

  2. Towards a Better Understanding of the Anomalous Hall Effect

    Science.gov (United States)

    Yue, Di; Jin, Xiaofeng

    2017-01-01

    Recent experimental efforts to identify the intrinsic and extrinsic contributions in the anomalous Hall effect are reviewed. Benefited from the experimental control of artificial impurity density in single crystalline magnetic thin films, a comprehensive physical picture of the anomalous Hall effect involving multiple competing scattering processes has been established. Some new insights into the microscopic mechanisms of the anomalous Hall effect are discussed.

  3. Accurate micro Hall effect measurements on scribe line pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Petersen, Dirch Hjorth; Wang, Fei

    2009-01-01

    Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can...

  4. Parametric Investigations of Non-Conventional Hall Thruster

    Energy Technology Data Exchange (ETDEWEB)

    Raitses, Y.; Fisch, N.J.

    2001-01-12

    Hall thrusters might better scale to low power with non-conventional geometry. A 9 cm cylindrical, ceramic-channel, Hall thruster with a cusp-type magnetic field distribution has been investigated. It exhibits discharge characteristics similar to conventional coaxial Hall thrusters, but does not expose as much channel surface. Significantly, its operation is not accompanied by large amplitude discharge low frequency oscillations.

  5. Digital technology impacts on the Arnhem transfer hall structural design

    NARCIS (Netherlands)

    Van de Straat, R.; Hofman, S.; Coenders, J.L.; Paul, J.C.

    2015-01-01

    The new Transfer Hall in Arnhem is one of the key projects to prepare the Dutch railways for the increased future demands for capacity. UNStudio developed a master plan in 1996 for the station area of which the completion of the Transfer Hall in 2015 will be a final milestone. The Transfer Hall is a

  6. Improved Hall-Effect Sensors For Magnetic Memories

    Science.gov (United States)

    Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.; Chen, Y. C.; Bhattacharya, Pallab K.

    1993-01-01

    High-electron-mobility sensor films deposited on superlattice buffer (strain) layers. Improved Hall-effect sensors offer combination of adequate response and high speed needed for use in micromagnet/Hall-effect random-access memories. Hall-effect material chosen for use in sensors is InAs.

  7. Inertial-Hall effect: the influence of rotation on the Hall conductivity

    Science.gov (United States)

    Brandão, Julio E.; Moraes, F.; Cunha, M. M.; Lima, Jonas R. F.; Filgueiras, C.

    Inertial effects play an important role in classical mechanics but have been largely overlooked in quantum mechanics. Nevertheless, the analogy between inertial forces on mass particles and electromagnetic forces on charged particles is not new. In this paper, we consider a rotating non-interacting planar two-dimensional electron gas with a perpendicular uniform magnetic field and investigate the effects of the rotation in the Hall conductivity. The rotation introduces a shift and a split in the Landau levels. As a consequence of the break of the degeneracy, the counting of the states fully occupied below the Fermi energy increases, tuning the Hall quantization steps. The rotation also changes the quantum Hall plateau widths. Additionally, we find the Hall quantization steps as a function of rotation at a fixed value of the magnetic field.

  8. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O.; Valentí, Roser

    2016-05-01

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions.

  9. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators.

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O; Valentí, Roser

    2016-05-17

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions.

  10. The magneto-Hall difference and the planar extraordinary Hall balance

    Directory of Open Access Journals (Sweden)

    S. L. Zhang

    2016-04-01

    Full Text Available The extraordinary Hall balance (EHB is a general device concept that harnesses the net extraordinary Hall effect (EHE arising from two independent magnetic layers, which are electrically in parallel. Different EHB behavior can be achieved by tuning the strength and type of interlayer coupling, i.e., ferromagnetic or antiferromagnetic of varying strength, allowing for logic and memory applications. The physics of the EHE in such a multilayered systems, especially the interface-induced effect, will be discussed. A discrepancy between the magnetization and the Hall effect, called the magneto-Hall difference (MHD is found, which is not expected in conventional EHE systems. By taking advantage of the MHD effect, and by optimizing the materials structure, magnetoresistance ratios in excess of 40,000% can be achieved at room-temperature. We present a new design, the planar EHB, which has the potential to achieve significantly larger magnetoresistance ratios.

  11. The magneto-Hall difference and the planar extraordinary Hall balance

    Science.gov (United States)

    Zhang, S. L.; Hesjedal, T.

    2016-04-01

    The extraordinary Hall balance (EHB) is a general device concept that harnesses the net extraordinary Hall effect (EHE) arising from two independent magnetic layers, which are electrically in parallel. Different EHB behavior can be achieved by tuning the strength and type of interlayer coupling, i.e., ferromagnetic or antiferromagnetic of varying strength, allowing for logic and memory applications. The physics of the EHE in such a multilayered systems, especially the interface-induced effect, will be discussed. A discrepancy between the magnetization and the Hall effect, called the magneto-Hall difference (MHD) is found, which is not expected in conventional EHE systems. By taking advantage of the MHD effect, and by optimizing the materials structure, magnetoresistance ratios in excess of 40,000% can be achieved at room-temperature. We present a new design, the planar EHB, which has the potential to achieve significantly larger magnetoresistance ratios.

  12. Inertial-Hall effect: the influence of rotation on the Hall conductivity

    Directory of Open Access Journals (Sweden)

    Julio E. Brandão

    2015-01-01

    Full Text Available Inertial effects play an important role in classical mechanics but have been largely overlooked in quantum mechanics. Nevertheless, the analogy between inertial forces on mass particles and electromagnetic forces on charged particles is not new. In this paper, we consider a rotating non-interacting planar two-dimensional electron gas with a perpendicular uniform magnetic field and investigate the effects of the rotation in the Hall conductivity. The rotation introduces a shift and a split in the Landau levels. As a consequence of the break of the degeneracy, the counting of the states fully occupied below the Fermi energy increases, tuning the Hall quantization steps. The rotation also changes the quantum Hall plateau widths. Additionally, we find the Hall quantization steps as a function of rotation at a fixed value of the magnetic field.

  13. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O.; Valentí, Roser

    2016-01-01

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions. PMID:27185665

  14. Nuclear fission: the interplay of science and technology.

    Science.gov (United States)

    Stoneham, A M

    2010-07-28

    When the UK's Calder Hall nuclear power station was connected to the grid in 1956, the programmes that made this possible involved a powerful combination of basic and applied research. Both the science and the engineering were novel, addressing new and challenging problems. That the last Calder Hall reactor was shut down only in 2003 attests to the success of the work. The strengths of bringing basic science to bear on applications continued to be recognized until the 1980s, when government and management fashions changed. This paper identifies a few of the technology challenges, and shows how novel basic science emerged from them and proved essential in their resolution. Today, as the threat of climate change becomes accepted, it has become clear that there is no credible solution without nuclear energy. The design and construction of new fission reactors will need continuing innovation, with the interplay between the science and technology being a crucial component.

  15. Hall instability of solar flux tubes

    CERN Document Server

    Pandey, B P

    2011-01-01

    The magnetic network which consists of vertical flux tubes located in intergranular lanes is dominated by Hall drift in the photosphere-lower chromosphere region ($\\lesssim 1\\,{Mm}$). In the internetwork regions, Hall drift dominates above $0.25\\,{Mm}$ in the photosphere and below $2.5\\,{Mm}$ in the chromosphere. Although Hall drift does not cause any dissipation in the ambient plasma, it can destabilise flux tubes and magnetic elements in the presence of an azimuthal shear flow, which destabilises whistler waves. The physical mechanism of this instability is quite simple: the shear flow twists the radial magnetic field and generates azimuthal field; torsional oscillations of the azimuthal field in turn generates the radial field completing a feedback loop. The maximum growth rate of the Hall instability is proportional to the absolute value of the shear gradient and is dependent on the ambient diffusivity. The diffusivity also determines the cut--off wavenumber which is narrower for the stronger fields. We a...

  16. Room acoustic properties of concert halls

    DEFF Research Database (Denmark)

    Gade, Anders Christian

    1996-01-01

    A large database of values of various room acoustic parameters has provided the basis for statistical analyses of how and how much the acoustic properties of concert halls are influenced by their size, shape, and absorption area (as deduced from measured reverberation time). The data have been...

  17. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...

  18. Anomalous Hall Effect for chiral fermions

    CERN Document Server

    Zhang, P -M

    2014-01-01

    Semiclassical chiral fermions manifest the anomalous spin-Hall effect: when put into a pure electric field, they suffer a side jump, analogous to what happens to their massive counterparts in non-commutative mechanics. The transverse shift is consistent with the conservation of the angular momentum. In a pure magnetic field a cork-screw-like, spiraling motion is found.

  19. Supersymmetry in the Fractional Quantum Hall Regime

    CERN Document Server

    Sagi, Eran

    2016-01-01

    Supersymmetry (SUSY) is a symmetry transforming bosons to fermions and vice versa. Indications of its existence have been extensively sought after in high-energy experiments. However, signatures of SUSY have yet to be detected. In this manuscript we propose a condensed matter realization of SUSY on the edge of a Read-Rezayi quantum Hall state, given by filling factors of the form $\

  20. Hall Effect Thruster Ground Testing Challenges

    Science.gov (United States)

    2009-08-18

    conditional stability of the inverted pendulum thrust stand provides improved measurement sensitivity.5 With the displacement of the inverted pendulum...July 2005. 12Samiento, C., “RHETT2/ EPDM Hall Thruster Propulsion System Electromagnetic Compatability Evaluation,” Proceed- ings of the 25th

  1. Development and applications of mesoscopic hall microprobes

    NARCIS (Netherlands)

    Novoselov, Konstantin S.

    2004-01-01

    This thesis is devoted to the further development of the local Hall magnetometery technique, and its application for studying ferromagnetic domain wall propagation on the sub-atomic scale. First the ballistic electron transport in a strong, non-uniform magnetic field is discussed. Than a possible in

  2. Fractional Quantization of the Hall Effect

    Science.gov (United States)

    Laughlin, R. B.

    1984-02-27

    The Fractional Quantum Hall Effect is caused by the condensation of a two-dimensional electron gas in a strong magnetic field into a new type of macroscopic ground state, the elementary excitations of which are fermions of charge 1/m, where m is an odd integer. A mathematical description is presented.

  3. Moderate positive spin Hall angle in uranium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Simranjeet; Anguera, Marta; Barco, Enrique del, E-mail: delbarco@ucf.edu, E-mail: cwmsch@rit.edu [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Springell, Ross [H. H. Will Laboratory, University of Bristol, Bristol BS2 8BS (United Kingdom); Miller, Casey W., E-mail: delbarco@ucf.edu, E-mail: cwmsch@rit.edu [School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York 14623 (United States)

    2015-12-07

    We report measurements of spin pumping and the inverse spin Hall effect in Ni{sub 80}Fe{sub 20}/uranium bilayers designed to study the efficiency of spin-charge interconversion in a super-heavy element. We employ broad-band ferromagnetic resonance on extended films to inject a spin current from the Ni{sub 80}Fe{sub 20} (permalloy) into the uranium layer, which is then converted into an electric field by the inverse spin Hall effect. Surprisingly, our results suggest a spin mixing conductance of order 2 × 10{sup 19} m{sup −2} and a positive spin Hall angle of 0.004, which are both merely comparable with those of several transition metals. These results thus support the idea that the electronic configuration may be at least as important as the atomic number in governing spin pumping across interfaces and subsequent spin Hall effects. In fact, given that both the magnitude and the sign are unexpected based on trends in d-electron systems, materials with unfilled f-electron orbitals may hold additional exploration avenues for spin physics.

  4. Dust exposure in indoor climbing halls.

    Science.gov (United States)

    Weinbruch, Stephan; Dirsch, Thomas; Ebert, Martin; Hofmann, Heiko; Kandler, Konrad

    2008-05-01

    The use of hydrated magnesium carbonate hydroxide (magnesia alba) for drying the hands is a strong source for particulate matter in indoor climbing halls. Particle mass concentrations (PM10, PM2.5 and PM1) were measured with an optical particle counter in 9 indoor climbing halls and in 5 sports halls. Mean values for PM10 in indoor climbing halls are generally on the order of 200-500 microg m(-3). For periods of high activity, which last for several hours, PM10 values between 1000 and 4000 microg m(-3) were observed. PM(2.5) is on the order of 30-100 microg m(-3) and reaches values up to 500 microg m(-3), if many users are present. In sports halls, the mass concentrations are usually much lower (PM10 sport in which magnesia alba is also used) similar dust concentrations as for indoor climbing were observed. The size distribution and the total particle number concentration (3.7 nm-10 microm electrical mobility diameter) were determined in one climbing hall by an electrical aerosol spectrometer. The highest number concentrations were between 8000 and 12 000 cm(-3), indicating that the use of magnesia alba is no strong source for ultrafine particles. Scanning electron microscopy and energy-dispersive X-ray microanalysis revealed that virtually all particles are hydrated magnesium carbonate hydroxide. In-situ experiments in an environmental scanning electron microscope showed that the particles do not dissolve at relative humidities up to 100%. Thus, it is concluded that solid particles of magnesia alba are airborne and have the potential to deposit in the human respiratory tract. The particle mass concentrations in indoor climbing halls are much higher than those reported for schools and reach, in many cases, levels which are observed for industrial occupations. The observed dust concentrations are below the current occupational exposure limits in Germany of 3 and 10 mg m(-3) for respirable and inhalable dust. However, the dust concentrations exceed the German guide

  5. The Magneto-Hall Difference and the Planar Extraordinary Hall Balance

    OpenAIRE

    S. L. Zhang; Hesjedal, T.

    2016-01-01

    The extraordinary Hall balance (EHB) is a general device concept that harnesses the net extraordinary Hall effect (EHE) arising from two independent magnetic layers, which are electrically in parallel. Different EHB behavior can be achieved by tuning the strength and type of interlayer coupling, i.e., ferromagnetic or antiferromagnetic of varying strength, allowing for logic and memory applications. The physics of the EHE in such a multilayered systems, especially the interface-induced effect...

  6. Topological honeycomb magnon Hall effect: A calculation of thermal Hall conductivity of magnetic spin excitations

    Science.gov (United States)

    Owerre, S. A.

    2016-07-01

    Quite recently, the magnon Hall effect of spin excitations has been observed experimentally on the kagome and pyrochlore lattices. The thermal Hall conductivity κxy changes sign as a function of magnetic field or temperature on the kagome lattice, and κxy changes sign upon reversing the sign of the magnetic field on the pyrochlore lattice. Motivated by these recent exciting experimental observations, we theoretically propose a simple realization of the magnon Hall effect in a two-band model on the honeycomb lattice. The magnon Hall effect of spin excitations arises in the usual way via the breaking of inversion symmetry of the lattice, however, by a next-nearest-neighbour Dzyaloshinsky-Moriya interaction. We find that κxy has a fixed sign for all parameter regimes considered. These results are in contrast to the Lieb, kagome, and pyrochlore lattices. We further show that the low-temperature dependence on the magnon Hall conductivity follows a T2 law, as opposed to the kagome and pyrochlore lattices. These results suggest an experimental procedure to measure thermal Hall conductivity within a class of 2D honeycomb quantum magnets and ultracold atoms trapped in a honeycomb optical lattice.

  7. Comparison of secondary islands in collisional reconnection to Hall reconnection.

    Science.gov (United States)

    Shepherd, L S; Cassak, P A

    2010-07-02

    Large-scale resistive Hall-magnetohydrodynamic simulations of the transition from Sweet-Parker (collisional) to Hall (collisionless) magnetic reconnection are presented; the first to separate secondary islands from collisionless effects. Three main results are described. There exists a regime with secondary islands but without collisionless effects, and the reconnection rate is faster than Sweet-Parker, but significantly slower than Hall reconnection. This implies that secondary islands do not cause the fastest reconnection rates. The onset of Hall reconnection ejects secondary islands from the vicinity of the X line, implying that energy is released more rapidly during Hall reconnection. Coronal applications are discussed.

  8. Parallel Hall effect from 3D single-component metamaterials

    CERN Document Server

    Kern, Christian; Wegener, Martin

    2015-01-01

    We propose a class of three-dimensional metamaterial architectures composed of a single doped semiconductor (e.g., n-Si) in air or vacuum that lead to unusual effective behavior of the classical Hall effect. Using an anisotropic structure, we numerically demonstrate a Hall voltage that is parallel---rather than orthogonal---to the external static magnetic-field vector ("parallel Hall effect"). The sign of this parallel Hall voltage can be determined by a structure parameter. Together with the previously demonstrated positive or negative orthogonal Hall voltage, we demonstrate four different sign combinations

  9. Diagnostics Systems for Permanent Hall Thrusters Development

    Science.gov (United States)

    Ferreira, Jose Leonardo; Soares Ferreira, Ivan; Santos, Jean; Miranda, Rodrigo; Possa, M. Gabriela

    This work describes the development of Permanent Magnet Hall Effect Plasma Thruster (PHALL) and its diagnostic systems at The Plasma Physics Laboratory of University of Brasilia. The project consists on the construction and characterization of plasma propulsion engines based on the Hall Effect. Electric thrusters have been employed in over 220 successful space missions. Two types stand out: the Hall-Effect Thruster (HET) and the Gridded Ion Engine (GIE). The first, which we deal with in this project, has the advantage of greater simplicity of operation, a smaller weight for the propulsion subsystem and a longer shelf life. It can operate in two configurations: magnetic layer and anode layer, the difference between the two lying in the positioning of the anode inside the plasma channel. A Hall-Effect Thruster-HET is a type of plasma thruster in which the propellant gas is ionized and accelerated by a magneto hydrodynamic effect combined with electrostatic ion acceleration. So the essential operating principle of the HET is that it uses a J x B force and an electrostatic potential to accelerate ions up to high speeds. In a HET, the attractive negative charge is provided by electrons at the open end of the Thruster instead of a grid, as in the case of the electrostatic ion thrusters. A strong radial magnetic field is used to hold the electrons in place, with the combination of the magnetic field and the electrostatic potential force generating a fast circulating electron current, the Hall current, around the axis of the Thruster, mainly composed by drifting electrons in an ion plasma background. Only a slow axial drift towards the anode occurs. The main attractive features of the Hall-Effect Thruster are its simple design and operating principles. Most of the Hall-Effect Thrusters use electromagnet coils to produce the main magnetic field responsible for plasma generation and acceleration. In this paper we present a different new concept, a Permanent Magnet Hall

  10. Reactor Physics Programme

    Energy Technology Data Exchange (ETDEWEB)

    De Raedt, C

    2000-07-01

    The Reactor Physics and Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis on reactor fuel. This expertise is applied within the Reactor Physics and MYRRHA Research Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments. Progress and achievements in 1999 in the following areas are reported on: (1) investigations on the use of military plutonium in commercial power reactors; (2) neutron and gamma calculations performed for BR-2 and for other reactors; (3) the updating of neutron and gamma cross-section libraries; (4) the implementation of reactor codes; (6) the management of the UNIX workstations; and (6) fuel cycle studies.

  11. Características del control prenatal y el parto de las mujeres inmigrantes atendidas en el Hospital "Dr. Rafael Ángel Calderón Guardia"

    Directory of Open Access Journals (Sweden)

    Manrique Leal-Mateos

    2008-06-01

    Full Text Available Justificación y objetivo: El presente estudio tiene como objetivo principal dar a conocer las características más sobresalientes del control prenatal y del parto de la población inmigrante que acude al Servicio de Obstetricia del Hospital Dr. Rafael A. Calderón Guardia, Costa Rica y comparar los resultados obtenidos con los observados en la población costarricense, con el fin de determinar si difieren entre sí. Materiales y métodos: Se realizó un estudio observacional analítico de corte transversal. Mediante un muestreo consecutivo se analizaron 360 historias clínicas de pacientes gestantes atendidas en HCG entre el 1 de agosto y 7 de septiembre de 2007. Se excluyó del análisis toda paciente que no perteneciera al área de atracción del HCG o que presentara de forma incompleta alguna de las variables de interés. La recolección de la información se realizó mediante una hoja precodificada diseñada con base la que se utiliza para el control prenatal en el sistema de salud nacional. Resultados: Aproximadamente una de cada 5 pacientes embarazadas que dan a luz en el HCG son inmigrantes. La mayor parte de ellas son de origen nicaragüense, relativamente jóvenes, multíparas y con controles prenatales adecuados. Además, presentan una morbilidad previa e inducida por el embarazo semejante a la encontrada en las gestantes nacionales. Si bien aproximadamente la mitad de las pacientes inmigrantes se captan de forma tardía y presentan una cantidad menor de consultas prenatales a la observada en las embarazadas costarricenses, este aspecto no parece influir en los resultados derivados de la atención de su parto ni en las características de los recién nacidos al momento de su nacimiento. Conclusión: Las características de la población inmigrante que da a luz en el Hospital no son diferentes a las encontradas en las mujeres costarricenses.

  12. Trombosis de senos durales: casuística del Hospital Dr. Rafael Angel Calderón Guardia, período 1996-1999

    Directory of Open Access Journals (Sweden)

    Kwok Ho Sánchez-Suen

    2001-10-01

    Full Text Available Justificación: La oclusión trombótica de las venas cerebrales o senos durales es una causa menos frecuente de enfermedad cerebrovascular que la trombosis arterial. Sin embargo; los estudios epidemiológicos indican que esta entidad no es tan inusual como o ser pensaba previamente. Hasta donde sabemos, no hay ningún estudio publicando al respecto en la literatura nacional, siendo precisamente el motivo del presente trabajo. Objetivos: Identificar las características demográficas, clínicas y diagnósticas de los pacientes que sufrieron una trombosis de senos venosos durales. Describir los métodos terapéuticos empleados y la evolución que tuvieron estos pacientes. Materiales y métodos: Se revisaron los expedientes clínicos de 11 casos diagnosticados de trombosis de senos durales en el Hospital Dr. Rafael Ángel Calderón Guardia, en el período comprendido entre enero de 1996 a enero de 1999. Se analizaron los posibles factores de riego, formas de presentación clínica, estudios de radio imagen y tratamiento empleado. Resultados: El promedio de edad fue de 32,6 años. Un 18,2% fueron varones, mientras que el 81,8% correspondió a mujeres. Las manifestaciones más frecuentes fueron: cefalea (100%, vómito (91%, déficit motor 882%, alteración del sensorio (73%, papiledema (54,5%, crisis convulsiva (54,5% y datos de irritación meníngea (36,4%: el signo del delta vacío se documentó en 27,3% de los estudios tomográficos. El seno sagital superior fue el más frecuentemente afectado (91%. Se anticoaguló con heparina intravenosa al 54, 5% de los casos. Conclusiones: Aunque somos conscientes de las limitaciones de nuestra serie, nuestra intención ha sido llamar la atención sobre una patología vascular cerebral, que aunque no es tan frecuente como su contraparte arterial, debe tenerse en consideración por sus potenciales efectos sobre la salud del paciente. El conocimiento adecuado de esta condición es importante, debido a que a

  13. [Epidemiological profile of traumatic brain injury at the Dr. Rafael A. Calderón Guardia Hospital, Neurosurgery Department, during the period from 2007 to 2012].

    Science.gov (United States)

    Petgrave-Pérez, Alexander; Padilla, Juan I; Díaz, José; Chacón, Rosarito; Chaves, Carlos; Torres, Héctor; Fernández, Jorge

    2016-01-01

    To determine the epidemiological profile of the patients who suffered traumatic brain injury (TBI) and were treated at the Dr. Rafael A. Calderón Guardia Hospital (HCG) Neurosurgery department, during the period from 2007 to 2012. An observational, descriptive, retrospective and cross section study was performed on all the patients with TBI and who were admitted to the emergency room of the HCG during the period 2007 to 2012. There were a total of 721 cases, of which 566 records were obtained of patients who had the variables established in this study, excluding those with incomplete or inconsistent information. The present study established the epidemiological profile of the TBI in the population seen during the period 2007 to 2012 at the HCG. It was determined that the male sex made up the majority of the cases were male, with mean age of 46 years. The mortality rate was 12.69% (n=69). Car accidents were the most frequent cause of TBI (n=259 persons) in the age group of 25 to 44 years, followed by falls (n=174). It was observed that the majority were farmers, followed by students, and then construction workers. No chronic illnesses were recorded in 71.6% of the medical charts. No alcohol or other drugs were reported in 74.9% of the cases, while there was evidence of the presence of alcohol recorded in 22.8%. The clinical and laboratory parameters that had statistical significance (Palcohol consumption. Also, the consequences of such are aggravated when the victims present with chronic diseases such as, systemic arterial hypertension and mellitus diabetes. As regards the post-traumatic indicators directly related to a poor outcome, it was determined that a GCS score equal to or less than 8, a mean blood pressure less than 60, the prolongation of the coagulation times, the presence of mydriasis, and skull fractures, have a direct association with the negative or fatal outcome for the victim. Copyright © 2015 Sociedad Española de Neurocirugía. Published by

  14. Acalasia, experiencia de 6 años. Hospital "Dr. Rafael Ángel Calderón Guardia" (2001-2007

    Directory of Open Access Journals (Sweden)

    Viviana Hernández-de Mezerville

    2009-04-01

    Full Text Available Objetivos: Caracterizar la población de pacientes vistos con esta entidad en el Hospital "Dr. Rafael Angel Calderón Guardia" durante los últimos 6 años y determinar su presentación clínica, método(s de diagnóstico utilizado (s, tratamiento brindado y evolución durante el primer año postratamiento. Materiales y métodos: Se analizaron los expedientes clínicos de hospitalización de los pacientes con acalasia atendidos desde enero de 2001 hasta enero de 2007; luego se revisaron las notas de evolución de la consulta externa de Gastroenterología durante el año posterior a la terapia brindada. Resultados: Durante el periodo se analizaron 30 pacientes en total. Hubo una discreta predominancia del género masculino y la edad promedio en el momento del diagnóstico fue de 50,37 años. El 100% de los pacientes presentó disfagia de larga data y los síntomas asociados más frecuentes fueron la pérdida de peso y el dolor torácico. Los métodos diagnósticos más utilizados fueron la manometría esofágica, la endoscopía y el esofagograma. El tratamiento que más se empleó fue la dilatación neumática seguida de la cirugía. El 50% de los pacientes reinició o persistió con disfagia durante el año siguiente a su tratamiento. La incidencia de complicaciones fue baja y no hubo perforación esofágica. Conclusiones: Las características generales y la presentación clínica de los pacientes coincidieron con lo descrito en la bibliografía. El tratamiento que más se brindó fue la dilatación neumática. La mitad de los pacientes presentaron o continuaron con síntomas postratamiento.

  15. Revisión crítica de la construcción de un mito en sacramentales El gran teatro del mundo y La vida es sueño, de Pedro Calderón de la Barca

    Directory of Open Access Journals (Sweden)

    Irene González Muñoz

    2012-11-01

    Full Text Available En este artículo se realiza una lectura de dos de los autos sacramentales de Pedro Calderón de la Barca, a partir de una revisión crítica que evidencia los presupuestos ideológicos que fundamentan estas producciones literarias.

  16. Attrition reactor system

    Science.gov (United States)

    Scott, Charles D.; Davison, Brian H.

    1993-01-01

    A reactor vessel for reacting a solid particulate with a liquid reactant has a centrifugal pump in circulatory flow communication with the reactor vessel for providing particulate attrition, resulting in additional fresh surface where the reaction can occur.

  17. The Hall Algebra of Cyclic Serial Algebra

    Institute of Scientific and Technical Information of China (English)

    郭晋云

    1994-01-01

    In this paper, orders <1 and <2 on ((Z)+)nm are introduced and also regarded as orders on the isomorphism classes of finite modules of finite .cyclic algebra R with n simple modules and all the indecomposable projective modules have length m through a one-to-one correspondence between ((Z)+)nm and the isomorphism classes of finite R modules. Using this we prove that the Hall algebra of a cyclic serial algebra is identified with its Loewy subalgebra, and its rational extension has a basis of BPW type, and is a (((Z)+)nm, <2) filtered ring with the associated graded ring as an iterated skew polynomial ring. These results are also generalized to the Hall algebra of a tube over a finite field.

  18. Three halls for music performance in Chile

    Science.gov (United States)

    Delannoy, Jaime; Heuffemann, Carolina; Ramirez, Daniel; Galvez, Fernando

    2002-11-01

    The primary purpose of this work was to investigate about the present acoustic conditions of used architectonic spaces in Santiago of Chile for orchestras of classic music performance. The studied halls were three: Aula Magna Universidad de Santiago, Teatro Municipal de Nunoa, and Teatro Baquedano. The used methodology was based on studies made by L. Beranek, M. Barron, among others, in concert halls worldwide. As it guides, for the measurement procedure, physical parameters RT, EDT, C50, C80, LF, BR, G, U50 were evaluated according to norm ISO 3382. On the other hand, it has been defined, to proposal way, a questionnaire of subjective valuation directed to musicians, specialized conductors, and listeners.

  19. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...... in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers. Correlations between the objective and subjective results lead, among others, to a recommendation for reverberation time as a function of hall volume. Since the bass...... frequency sounds are typically highly amplified, they play an important role in the subjective ratings and the 63-Hz-band must be included in objective measurements and recommendations....

  20. Judy Estes Hall (1940-2015).

    Science.gov (United States)

    Sammons, Morgan T; Boucher, Andrew

    2016-01-01

    Presents an obituary for Judy Estes Hall, who passed away on November 24, 2015. Hall served as the Executive Officer of the National Register of Health Service Psychologists until her retirement in 2013. She is a recognized expert in the development of education and training standards for the profession of psychology, she also made significant contributions in the field of international psychology, where she was a renowned expert in cross-national credentialing and an advocate for commonality in licensing standards. She was the coauthor of one edited volume and author of more than 60 journal articles, book chapters, and professional publications. A passionate advocate for the advancement of women in psychology, a devoted mother and grandmother, a connoisseur of wine and international traveler extraordinaire, she touched the personal and professional lives of many. (PsycINFO Database Record

  1. Hall Scrambling on Black Hole Horizon

    CERN Document Server

    Fischler, Willy

    2015-01-01

    We explore the effect of the electrodynamics $\\theta$-angle on the macroscopic properties of black hole horizons. Using only classical Einstein-Maxwell-Chern-Simons theory in (3+1)-dimensions, in the form of the membrane paradigm, we show that in the presence of the $\\theta$-term, a black hole horizon behaves as a Hall conductor, for an observer hovering outside. We study how localized perturbations created on the stretched horizon scramble on the horizon by dropping a charged particle. We show that the $\\theta$-angle affects the way perturbations scramble on the horizon, in particular, it introduces vortices without changing the scrambling time. This Hall scrambling of information is also expected to occur on cosmological horizons.

  2. Music hall Markneukirchen; Musikhalle in Markneukirchen

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1996-01-01

    The article presents the new building of the music hall Markneukirchen. From the planned use of the building result very high demands on the ventilation system in order to keep to a sound power level of less than 30 dB(A) in the hall. The building services are dealt with using numerous flowsheets and diagrams: Heat supply, ventilation system, sanitary system, building management, instrumentation and control, electric and lighting systems. (BWI) [Deutsch] Der vorliegende Beitrag stellt den Neubau der Musikhalle Markneukirchen vor. Durch das Nutzungskonzept ergeben sich fuer die Einhaltung eines Schalleistungspegels von weniger als 30 dB(A) im Saalbereich an die Lueftungsanlage sehr hohe Ansprueche. Es werden die raumlufttechnischen Anlagen anhand zahlreicher Flussbilder und Abbildungen vorgestellt: Waermeversorgung, Lueftungstechnik, Sanitaertechnik, Gebaeudeleit- und MSR-Technik, Elektro- und Lichttechnik. (BWI)

  3. SPS beam to the West Hall

    CERN Multimedia

    1976-01-01

    One of the two target stations feeding the West Hall (see Annual Report 1976). After the proton beam was split into three branches, the outer two were directed on to targets in the cast iron shielding box, the centre one passing through the box to another target station downstream. Five different targets could be put in each beam, controlled by the mechanism seen on top.

  4. Geometric Photonic Spin Hall Effect with Metapolarization

    OpenAIRE

    2014-01-01

    We develop a geometric photonic spin Hall effect (PSHE) which manifests as spin-dependent shift in momentum space. It originates from an effective space-variant Pancharatnam-Berry (PB) phase created by artificially engineering the polarization distribution of the incident light. Unlikely the previously reported PSHE involving the light-matter interaction, the resulting spin-dependent splitting in the geometric PSHE is purely geometrically depend upon the polarization distribution of light whi...

  5. Thermal Characterization of a Hall Effect Thruster

    Science.gov (United States)

    2008-03-01

    Material Curie Temperature Iron 770 °C Nickel 358 °C Cobalt 1130 °C Gadolinium 20 °C Terfenol 380-430 °C Alnico 850 °C Hard Ferrites 400-700...C Barium Ferrite 450 °C Hall Effect thrusters generally use iron magnets with a Curie temperature of 770 °C. Decreasing the magnetic strength

  6. Electron-wall Interaction in Hall Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    Y. Raitses; D. Staack; M. Keidar; N.J. Fisch

    2005-02-11

    Electron-wall interaction effects in Hall thrusters are studied through measurements of the plasma response to variations of the thruster channel width and the discharge voltage. The discharge voltage threshold is shown to separate two thruster regimes. Below this threshold, the electron energy gain is constant in the acceleration region and therefore, secondary electron emission (SEE) from the channel walls is insufficient to enhance electron energy losses at the channel walls. Above this voltage threshold, the maximum electron temperature saturates.

  7. Homotopy arguments for quantized Hall conductivity

    CERN Document Server

    Richter, T

    2002-01-01

    Using the strong localization bounds obtained by the Aizenman-Molcanov method for a particle in a magnetic field and a disordered potential, we show that the zero-temperature Hall conductivity of a gas of such particles is quantized and constant as long as both Fermi energy and disorder coupling parameter vary in a region of strong localization of the corresponding two-dimensional phase diagram.

  8. Industrial steel hall with bridge grane

    OpenAIRE

    Jurejevčič, Nejc

    2016-01-01

    In introduction this diploma thesis describes all main characteristics of (single block)? industrial steel hall with bridge crane. Load arrangement on the supporting structure which covers general actions (snow load and wind action), self-weight and dynamic load of bridge crane was designed with moment resisting frame in transverse direction and frame with concentric diagonal bracing in longitudinual direction. Actions induced by crane bridge was considered in design of runway beam. Steel hal...

  9. The Hall D Physics Program at JLab

    Energy Technology Data Exchange (ETDEWEB)

    Leckey, John P. [Indiana U.

    2012-09-01

    GlueX is one of the flagship experiments of the 12 GeV era at the Thomas Jefferson National Accelerator Facility (JLab). The energy of the electron accelerator at JLab is presently undergoing an upgrade from 6 GeV to 12 GeV and a 4th experimental hall (Hall D) is being added. The GlueX experimental apparatus consists of a tagged coherent bremsstrahlung photon beam incident on a liquid hydrogen target. The photoproduced mesons, which are created inside of a 2.2 T solenoid, will then pass through a pair of drift chambers and eventually deposit their energy into either of two calorimeters, depending on their respective angles. GlueX will attempt to map out the light meson spectrum and search for meson-gluon hybrids to better understand the confinement of quarks and gluons in quantum chromodynamics (QCD). There is little data on the photoproduction of light mesons and the GlueX experiment will exceed the current photoproduction data by several orders of magnitude in the first year alone. Photoproduction is specifically well suited to search for meson-gluon hybrids because in the flux tube model the production cross-sections are higher for meson-gluon hybrids from photons, with the spins of the virtual quark-antiquark pair aligned, than from other sources such as pions, with the spins of the quark-antiquark pair anti-aligned. There are also other Hall D experiments proposed to look for physics beyond the Standard Model by studying Eta rare or forbidden decay channels such as eta to two neutral pions. The 12 GeV upgrade of the JLab accelerator and the complete physics program of Hall D will be presented.

  10. Views of the ATLAS experimental hall

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The shell of the ATLAS detector is seen from many angles within its cavernous underground hall. All of the eight huge toroid magnets have been installed and fixed in place. The core of the detector, the largest of its type in the world, will soon be filled with many different detector-elements to observe the results of proton-proton collisions at the LHC when it is turned on in 2008.

  11. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues in D...... frequency sounds are typically highly amplified, they play an important role in the subjective ratings and the 63-Hz-band must be included in objective measurements and recommendations....

  12. SERVIR Town Hall - Connecting Space to Village

    Science.gov (United States)

    Limaye, Ashutosh S.; Searby, Nancy D.; Irwin, Daniel; Albers, Cerese

    2013-01-01

    SERVIR, a joint NASA-USAID project, strives to improve environmental decision making through the use of Earth observations, models, and geospatial technology innovations. SERVIR connects these assets with the needs of end users in Mesoamerica, East Africa, and Hindu Kush-Himalaya regions. This Town Hall meeting will engage the AGU community by exploring examples of connecting Space to Village with SERVIR science applications.

  13. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hiroto

    1995-02-07

    A reactor container of the present invention has a structure that the reactor container is entirely at the same temperature as that at the inlet of the reactor and, a hot pool is incorporated therein, and the reactor container has is entirely at the same temperature and has substantially uniform temperature follow-up property transiently. Namely, if the temperature at the inlet of the reactor core changes, the temperature of the entire reactor container changes following this change, but no great temperature gradient is caused in the axial direction and no great heat stresses due to axial temperature distribution is caused. Occurrence of thermal stresses caused by the axial temperature distribution can be suppressed to improve the reliability of the reactor container. In addition, since the laying of the reactor inlet pipelines over the inside of the reactor is eliminated, the reactor container is made compact and the heat shielding structures above the reactor and a protection structure of container walls are simplified. Further, secondary coolants are filled to the outside of the reactor container to simplify the shieldings. The combined effects described above can improve economical property and reliability. (N.H.).

  14. A Magnetic Balance with Hall Effect Sensors

    Science.gov (United States)

    Sawada, Hideo; Kunimasu, Tetsuya; Suda, Shinichi; Mizoguti, Yasushi; Okada, Takumi

    Magnetic force acting on a model fixed at the center of the JAXA 60cm MSBS was measured with an industry manufactured balance system when MSBS control coil currents were varied. At the same time, magnetic field intensity was also measured with 11 Hall sensors, which were arranged around the MSBS test section. From relations between coil currents and its corresponding controlled magnetic forces, regressive curves were given and maximum deviation from the curves was evaluated. From relations between Hall sensor outputs and the magnetic forces, regressive curves and deviation were also obtained. Obtained results show Hall sensor outputs are much better indexes of balance than the coil currents. The maximum deviations were reduced to a half or one-third times as much as those evaluated using the control coil currents. However, when couples acting on the model are controlled, they are not effective to reduce hysteresis phenomenon in the relation. The deviation can be reduced by decreasing the range of calibration. Then, the error of the balance of the MSBS was reduced to about 1% of the calibration range.

  15. Hall measurements on InAs nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Bloemers, Christian; Grap, Thomas; Lepsa, Mihail I.; Gruetzmacher, Detlev; Lueth, Hans [Peter Gruenberg Institut (PGI-9), Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); JARA - Fundamentals of Future Information Technology (Germany); Trellenkamp, Stefan [Peter Gruenberg Institut (PGI-8), Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); JARA - Fundamentals of Future Information Technology (Germany); Schaepers, Thomas [Peter Gruenberg Institut (PGI-9), Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); JARA - Fundamentals of Future Information Technology (Germany); II. Physikalisches Institut, RWTH Aachen, 52074 Aachen (Germany)

    2012-07-01

    In search of novel concepts for the realization of nanoelectronic devices, semiconductor nanowires grown by ''bottom-up'' techniques have shown great promise. Without any doubt, the knowledge about the free carrier concentration n{sub el} is crucial for the fabrication of such devices on the nanometer scale. The most common method to determine n{sub el} in nanowires is to utilize the field effect in a gate measurement setup. However, within this method, uncertainties such as the density of surface states between the nanowire and the dielectric material or the resulting nanowire capacitance influence results. Additionally, source and drain electrodes tend to screen the gate potential in devices of small size. Here we report on Hall measurements on InAs nanowires as an alternative method to determine n{sub el}. By electron beam lithography we are able to fabricate side contacts to single nanowires to realize a Hall-measurement geometry. The side contacts allow us to measure a Hall-voltage, from which we deduce the carrier concentration in the wires.

  16. Quantum anomalous Hall effect in real materials

    Science.gov (United States)

    Zhang, Jiayong; Zhao, Bao; Zhou, Tong; Yang, Zhongqin

    2016-11-01

    Under a strong magnetic field, the quantum Hall (QH) effect can be observed in two-dimensional electronic gas systems. If the quantized Hall conductivity is acquired in a system without the need of an external magnetic field, then it will give rise to a new quantum state, the quantum anomalous Hall (QAH) state. The QAH state is a novel quantum state that is insulating in the bulk but exhibits unique conducting edge states topologically protected from backscattering and holds great potential for applications in low-power-consumption electronics. The realization of the QAH effect in real materials is of great significance. In this paper, we systematically review the theoretical proposals that have been brought forward to realize the QAH effect in various real material systems or structures, including magnetically doped topological insulators, graphene-based systems, silicene-based systems, two-dimensional organometallic frameworks, quantum wells, and functionalized Sb(111) monolayers, etc. Our paper can help our readers to quickly grasp the recent developments in this field. Project supported by the National Basic Research Program of China (Grant No. 2011CB921803), the National Natural Science Foundation of China (Grant No. 11574051), the Natural Science Foundation of Shanghai, China (Grant No. 14ZR1403400), and Fudan High-end Computing Center, China.

  17. Generic superweak chaos induced by Hall effect.

    Science.gov (United States)

    Ben-Harush, Moti; Dana, Itzhack

    2016-05-01

    We introduce and study the "kicked Hall system" (KHS), i.e., charged particles periodically kicked in the presence of uniform magnetic (B) and electric (E) fields that are perpendicular to each other and to the kicking direction. We show that for resonant values of B and E and in the weak-chaos regime of sufficiently small nonintegrability parameter κ (the kicking strength), there exists a generic family of periodic kicking potentials for which the Hall effect from B and E significantly suppresses the weak chaos, replacing it by "superweak" chaos (SWC). This means that the system behaves as if the kicking strength were κ^{2} rather than κ. For E=0, SWC is known to be a classical fingerprint of quantum antiresonance, but it occurs under much less generic conditions, in particular only for very special kicking potentials. Manifestations of SWC are a decrease in the instability of periodic orbits and a narrowing of the chaotic layers, relative to the ordinary weak-chaos case. Also, for global SWC, taking place on an infinite "stochastic web" in phase space, the chaotic diffusion on the web is much slower than the weak-chaos one. Thus, the Hall effect can be relatively stabilizing for small κ. In some special cases, the effect is shown to cause ballistic motion for almost all parameter values. The generic global SWC on stochastic webs in the KHS appears to be the two-dimensional closest analog to the Arnol'd web in higher dimensional systems.

  18. Antiferromagnetic skyrmion crystals: Generation, topological Hall, and topological spin Hall effect

    Science.gov (United States)

    Göbel, Börge; Mook, Alexander; Henk, Jürgen; Mertig, Ingrid

    2017-08-01

    Skyrmions are topologically nontrivial, magnetic quasiparticles that are characterized by a topological charge. A regular array of skyrmions, a skyrmion crystal (SkX), features the topological Hall effect (THE) of electrons, which, in turn, gives rise to the Hall effect of the skyrmions themselves. It is commonly believed that antiferromagnetic skyrmion crystals (AFM-SkXs) lack both effects. In this Rapid Communication, we present a generally applicable method to create stable AFM-SkXs by growing a two-sublattice SkX onto a collinear antiferromagnet. As an example we show that both types of skyrmion crystals, conventional and antiferromagnetic, exist in honeycomb lattices. While AFM-SkXs with equivalent lattice sites do not show a THE, they exhibit a topological spin Hall effect. On top of this, AFM-SkXs on inequivalent sublattices exhibit a nonzero THE, which may be utilized in spintronics devices. Our theoretical findings call for experimental realization.

  19. Dissipationless spin-Hall current contribution in the extrinsic spin-Hall effect

    Institute of Scientific and Technical Information of China (English)

    Yan Yu-Zhen; Li Hui-Wu; Hu Liang-Bin

    2009-01-01

    This paper shows that a substantial amount of dissipationless spin-Hall current contribution may exist in the extrinsic spin-Hall effect, which originates from the spin-orbit coupling induced by the applied external electric field itself that drives the extrinsic spin-Hall effect in a nonmagnetic semiconductor (or metal). By assuming that the impurity density is in a moderate range such that the total scattering potential due to all randomly distributed impurities is a smooth function of the space coordinate, it is shown that this dissipationless contribution shall be of the same orders of magnitude as the usual extrinsic contribution from spin-orbit dependent impurity scatterings (or may even be larger than the latter one). The theoretical results obtained are in good agreement with recent relevant experimental results.

  20. Light water reactor safety

    CERN Document Server

    Pershagen, B

    2013-01-01

    This book describes the principles and practices of reactor safety as applied to the design, regulation and operation of light water reactors, combining a historical approach with an up-to-date account of the safety, technology and operating experience of both pressurized water reactors and boiling water reactors. The introductory chapters set out the basic facts upon which the safety of light water reactors depend. The central section is devoted to the methods and results of safety analysis. The accidents at Three Mile Island and Chernobyl are reviewed and their implications for light wate

  1. Nuclear reactor physics

    CERN Document Server

    Stacey, Weston M

    2010-01-01

    Nuclear reactor physics is the core discipline of nuclear engineering. Nuclear reactors now account for a significant portion of the electrical power generated worldwide, and new power reactors with improved fuel cycles are being developed. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. The second edition of this successful comprehensive textbook and reference on basic and advanced nuclear reactor physics has been completely updated, revised and enlarged to include the latest developme

  2. Spinning fluids reactor

    Science.gov (United States)

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  3. Commemorative Symposium on the Hall Effect and its Applications

    CERN Document Server

    Westgate, C

    1980-01-01

    In 1879, while a graduate student under Henry Rowland at the Physics Department of The Johns Hopkins University, Edwin Herbert Hall discovered what is now universally known as the Hall effect. A symposium was held at The Johns Hopkins University on November 13, 1979 to commemorate the lOOth anniversary of the discovery. Over 170 participants attended the symposium which included eleven in­ vited lectures and three speeches during the luncheon. During the past one hundred years, we have witnessed ever ex­ panding activities in the field of the Hall effect. The Hall effect is now an indispensable tool in the studies of many branches of condensed matter physics, especially in metals, semiconductors, and magnetic solids. Various components (over 200 million!) that utilize the Hall effect have been successfully incorporated into such devices as keyboards, automobile ignitions, gaussmeters, and satellites. This volume attempts to capture the important aspects of the Hall effect and its applications. It includes t...

  4. Basic Instrumentation for Hall A at Jefferson Jab

    Energy Technology Data Exchange (ETDEWEB)

    The Jefferson Lab Hall A Collaboration

    2003-07-01

    The instrumentation in Hall A at the JLab was designed to study electro- and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. A collaboration of approximately 50 institutions from all over the world has actively contributed and participated in the design, construction and commissioning of the Hall A instrumentation. The basic Hall A equipment is described herein.

  5. Estimates of Quantities in a Hall Effect Geodynamo Theory

    Directory of Open Access Journals (Sweden)

    Annraoi M de Paor

    2008-01-01

    Full Text Available Currents, resistances, dynamo constant, Hall voltage coefficient and inductances are estimated for the author’s geodynamo theory incorporating the Hall Effect. It is concluded that the Hall Coefficient in the bulk liquid core of the Earth is approximately 1.512x10-1, orders of magnitude greater than in normal liquid metals. The ordering effect of enormous pressure is a possible cause.

  6. Estimates of quantities in a Hall effect geodynamo theory

    OpenAIRE

    Annraoi M de Paor

    2008-01-01

    Currents, resistances, dynamo constant, Hall voltage coefficient and inductances are estimated for the author’s geodynamo theory incorporating the Hall Effect. It is concluded that the Hall Coefficient in the bulk liquid core of the Earth is approximately 1.512x10-1, orders of magnitude greater than in normal liquid metals. The ordering effect of enormous pressure is a possible cause.

  7. Charge and Current in the Quantum Hall Matrix Model

    OpenAIRE

    2003-01-01

    We extend the quantum Hall matrix model to include couplings to external electric and magnetic fields. The associated current suffers from matrix ordering ambiguities even at the classical level. We calculate the linear response at low momenta -- this is unambigously defined. In particular, we obtain the correct fractional quantum Hall conductivity, and the expected density modulations in response to a weak and slowly varying magnetic field. These results show that the classical quantum Hall ...

  8. Hall effect in strongly correlated low dimensional systems

    OpenAIRE

    Leon Suros, Gladys Eliana; Berthod, Christophe; Giamarchi, Thierry

    2006-01-01

    We investigate the Hall effect in a quasi one-dimensional system made of weakly coupled Luttinger Liquids at half filling. Using a memory function approach, we compute the Hall coefficient as a function of temperature and frequency in the presence of umklapp scattering. We find a power-law correction to the free-fermion value (band value), with an exponent depending on the Luttinger parameter $K_{\\rho}$. At high enough temperature or frequency the Hall coefficient approaches the band value.

  9. Fabrication of a vector Hall sensor for magnetic microscopy

    Science.gov (United States)

    Gregušová, D.; Cambel, V.; Fedor, J.; Kúdela, R.; Šoltýs, J.; Lalinský, T.; Kostič, I.; Bending, S. J.

    2003-05-01

    We have developed a micromachined Hall sensor for scanning the entire magnetic field vector whose active dimensions are an order of magnitude smaller (˜5 μm) than the smallest existing vector field sensor. It is realized by patterning three Hall probes on the tilted faces of epitaxy-overgrown GaAs-based pyramidal-shaped mesa structures. Data from these "tilted" Hall probes are used to reconstruct the full magnetic field vector.

  10. Quantized Thermal Transport in the Fractional Quantum Hall Effect

    OpenAIRE

    Kane, C. L.; Fisher, Matthew P. A.

    1996-01-01

    We analyze thermal transport in the fractional quantum Hall effect (FQHE), employing a Luttinger liquid model of edge states. Impurity mediated inter-channel scattering events are incorporated in a hydrodynamic description of heat and charge transport. The thermal Hall conductance, $K_H$, is shown to provide a new and universal characterization of the FQHE state, and reveals non-trivial information about the edge structure. The Lorenz ratio between thermal and electrical Hall conductances {\\i...

  11. Pseudospectral Model for Hybrid PIC Hall-effect Thruster Simulation

    Science.gov (United States)

    2015-07-01

    1149. 8Goebel, D. M. and Katz, I., Fundamentals of Electric Propulsion : Ion and Hall Thrusters, John Wiley & Sons, Inc., 2008. 9Martin, R., J.W., K...Bilyeu, D., and Tran, J., “Dynamic Particle Weight Remapping in Hybrid PIC Hall -effect Thruster Simulation,” 34th Int. Electric Propulsion Conf...Paper 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE Pseudospectral model for hybrid PIC Hall -effect thruster simulationect

  12. The Hall module of an exact category with duality

    OpenAIRE

    Young, Matthew B.

    2012-01-01

    We construct from a finitary exact category with duality a module over its Hall algebra, called the Hall module, encoding the first order self-dual extension structure of the category. We study in detail Hall modules arising from the representation theory of a quiver with involution. In this case we show that the Hall module is naturally a module over the specialized reduced sigma-analogue of the quantum Kac-Moody algebra attached to the quiver. For finite type quivers, we explicitly determin...

  13. Dynamic Feedback in Ferromagnet-Spin Hall Metal Heterostructures

    Science.gov (United States)

    Cheng, Ran; Zhu, Jian-Gang; Xiao, Di

    2016-08-01

    In ferromagnet-normal-metal heterostructures, spin pumping and spin-transfer torques are two reciprocal processes that occur concomitantly. Their interplay introduces a dynamic feedback effect interconnecting energy dissipation channels of both magnetization and current. By solving the spin diffusion process in the presence of the spin Hall effect in the normal metal, we show that the dynamic feedback gives rise to (i) a nonlinear magnetic damping that is crucial to sustain uniform steady-state oscillations of a spin Hall oscillator at large angles and (ii) a frequency-dependent spin Hall magnetoimpedance that reduces to the spin Hall magnetoresistance in the dc limit.

  14. Composite particle and field theory in atomic quantum Hall effect

    Institute of Scientific and Technical Information of China (English)

    Zhao Bo; Chen Zeng-Bing

    2005-01-01

    In this paper, we explore the composite particle description of the atomic quantum Hall (QH) effect. We further give the Chern-Simon-Gross-Pitaevskii (CSGP) effective theory for the atomic Hall liquid, which is the counterpart of Chern-Simon theory in electron Hall effect. What we obtained is equivalent to the Laughlin wavefunction approach.Our results show that in terms of composite particles, the atomic Hall effect is really the same as the electronic QH effect. The CSGP effective theory would shed new light on the atomic QH effect.

  15. High Efficiency Hall Thruster Discharge Power Converter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek leveraged previous, internally sponsored, high power, Hall thruster discharge converter development which allowed it to design, build, and test new printed...

  16. Hall Sensor Output Signal Fault-Detection & Safety Implementation Logic

    Directory of Open Access Journals (Sweden)

    Lee SangHun

    2016-01-01

    Full Text Available Recently BLDC motors have been popular in various industrial applications and electric mobility. Recently BLDC motors have been popular in various industrial applications and electric mobility. In most brushless direct current (BLDC motor drives, there are three hall sensors as a position reference. Low resolution hall effect sensor is popularly used to estimate the rotor position because of its good comprehensive performance such as low cost, high reliability and sufficient precision. Various possible faults may happen in a hall effect sensor. This paper presents a fault-tolerant operation method that allows the control of a BLDC motor with one faulty hall sensor and presents the hall sensor output fault-tolerant control strategy. The situations considered are when the output from a hall sensor stays continuously at low or high levels, or a short-time pulse appears on a hall sensor signal. For fault detection, identification of a faulty signal and generating a substitute signal, this method only needs the information from the hall sensors. There are a few research work on hall effect sensor failure of BLDC motor. The conventional fault diagnosis methods are signal analysis, model based analysis and knowledge based analysis. The proposed method is signal based analysis using a compensation signal for reconfiguration and therefore fault diagnosis can be fast. The proposed method is validated to execute the simulation using PSIM.

  17. Probing magnetic microstructures with quasi-ballistic Hall crosses

    Science.gov (United States)

    Fasbender, S.; Schluck, J.; Cerchez, M.; Heinzel, T.; Sievers, S.; Pierz, K.; Schumacher, H. W.

    2016-03-01

    Hall sensing is performed on a localized magnetic field pattern using a quasi-ballistic Hall cross device. The Hall resistance shows a pronounced peak as a function of the magnetic field amplitude which is absent in the magnetization hysteresis loop. This non-monotonic response exemplifies qualitatively the failure of conventional Hall sensing. It is demonstrated how, by using a numerical simulation based on the Landauer-Büttiker model, the amplitude of the magnetic field profile can be determined from such measurements.

  18. Hall and Nernst effects in monolayer MoS2

    Science.gov (United States)

    Zhang, Yun-Hai; Zhang, Ming-Hua

    2016-03-01

    We study Hall and Nernst transports in monolayer MoS2 based on Green’s function formalism. We have derived analytical results for spin and valley Hall conductivities in the zero temperature and spin and valley Nernst conductivities in the low temperature. We found that tuning of the band gap and spin-orbit splitting can drive system transition from spin Hall insulator (SHI) to valley Hall insulator (VHI). When the system is subjected to a temperature gradient, the spin and valley Nernst conductivities are dependent on Berry curvature.

  19. Quantized Anomalous Hall Effect in Magnetic Topological Insulators

    Institute of Scientific and Technical Information of China (English)

    YU Rui

    2011-01-01

    @@ The Hall effect, the anomalous Hall effect (AHE) and the spin Hall effect are fundamental transport processes in solids arising from the Lorentz force and the spin-orbit coupling respectively.The AHE, in which a voltage transverse to the electric current appears even in the absence of an external magnetic field, was first detected in ferromagnetic (FM) metals in 1881 and later found to arise from the spin-orbit coupling (SOC) between the current and magnetic moments.Recent progress on the mechanism of AHE has established a link between the AHE and the topological nature of the Hall current by adopting the Berry-phase concepts in close analogy to the intrinsic spin Hall effect.Given the experimental discovery of the quantum Hall and the quantum spin Hall effects, it is natural to ask whether the AHE can also be quantized.In a quantized anomalous Hall (QAH) insulator, spontaneous magnetic moments and spin-orbit coupling combine to give rise to a topologically non-trivial electronic structure, leading to the quantized Hall effect without any external magnetic field.

  20. MAGNETORESISTANCE AND HALL EFFECT IN SINGLE CRYSTALS OF ALUMINUM

    Science.gov (United States)

    ALUMINUM, *SINGLE CRYSTALS, CRYSTALS, HALL EFFECT , IMPURITIES, LOW PRESSURE, MAGNETIC FIELDS, MAGNETIC PROPERTIES, PARTICLE TRAJECTORIES, ELECTRICAL RESISTANCE, SOLID STATE PHYSICS, SURFACE PROPERTIES.

  1. Laughlin's argument for the quantized thermal Hall effect

    CERN Document Server

    Nakai, Ryota; Nomura, Kentaro

    2016-01-01

    We extend Laughlin's magnetic-flux-threading argument to the quantized thermal Hall effect. A proper analogue of Laughlin's adiabatic magnetic-flux threading process for the case of the thermal Hall effect is given in terms of an external gravitational field. From the perspective of the edge theories of quantum Hall systems, the quantized thermal Hall effect is closely tied to the breakdown of large diffeomorphism invariance, that is, a global gravitational anomaly. In addition, we also give an argument from the bulk perspective in which a free energy, decomposed into its Fourier modes, is adiabatically transferred under an adiabatic process involving external gravitational perturbations.

  2. Reactor Vessel Surveillance Program for Advanced Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyeong-Hoon; Kim, Tae-Wan; Lee, Gyu-Mahn; Kim, Jong-Wook; Park, Keun-Bae; Kim, Keung-Koo

    2008-10-15

    This report provides the design requirements of an integral type reactor vessel surveillance program for an integral type reactor in accordance with the requirements of Korean MEST (Ministry of Education, Science and Technology Development) Notice 2008-18. This report covers the requirements for the design of surveillance capsule assemblies including their test specimens, test block materials, handling tools, and monitors of the surveillance capsule neutron fluence and temperature. In addition, this report provides design requirements for the program for irradiation surveillance of reactor vessel materials, a layout of specimens and monitors in the surveillance capsule, procedures of installation and retrieval of the surveillance capsule assemblies, and the layout of the surveillance capsule assemblies in the reactor.

  3. Roger Calder (1934 – 2014)

    CERN Multimedia

    2014-01-01

    Roger joined CERN’s Accelerator-Research Division in May 1963, at the beginning of the Intersecting Storage Rings (ISR) project. The challenge was to evacuate the two beam pipes of about 1 km each to 10-7 Pa and to obtain a beam lifetime of 20 hours. An ultra-high vacuum system of this size and complexity required the most advanced technologies available.   Among the outstanding contributions by Roger were: the choice of turbomolecular- and ion-pumps, low outgassing rates and an all-metal system bakeable to 300°C. Still today, Roger’s name is linked to "900°C vacuum degassed stainless steel" for very low hydrogen outgassing. The unexpected dynamic pressure run-away during the ISR start-up, at only a few A of beam, was quickly identified as the "ion-induced pressure bump instability". Among Roger’s efforts to mitigate this effect, the pumping system was supplemented with titanium sublimation pumps. In a second s...

  4. Plan para la Dirección del Proyecto Construcción y Equipamiento del Departamento de Hemato Oncología del Hospital Dr. Rafael Ángel Calderón Guardia

    OpenAIRE

    Pacheco-Solano, Alejandro; Acuña-Rivas, Gregory Andrés

    2013-01-01

    Proyecto de Graduación (Maestría en Gerencia de Proyectos) Instituto Tecnológico de Costa Rica, Área Académica de Gerencia de Proyectos, 2013. El trabajo de graduación consiste en la elaboración del Plan para la Dirección del Proyecto Construcción y Equipamiento del Departamento de Hemato Oncología del Hospital Dr. Rafael Ángel Calderón Guardia, a cargo de la Unidad Proyecto Red Oncológica, adscrita a la Dirección Administración de Proyectos Especiales de la Caja Costarricense de Seguro So...

  5. El papel de las TIC en la transformación del modelo escuela nueva de la Institución Educativa Octavio Calderón Mejía

    OpenAIRE

    Hurtado Pérez, Gloria Inés; Vélez Holguín, Rosa María

    2010-01-01

    Ubicación en Biblioteca USB Medellín (San Benito): CD-1635t .-- Grupo de Investigación en Epistemologías y Metodologías en la Educación y la Motricidad "EPIMEM".-- Línea de Investigación: Saberes y Prácticas en Educación y Motricidad - Área: Currículo - Tema: Medios y Tecnologías de Información y Comunicación El objetivo del trabajo es analizar como la implementación de las TIC puede transformar el modelo Escuela Nueva de la Institución Educativa Octavio Calderón Mejía. Nuestro trabajo se ...

  6. Twins of TWIP Steel and Its Effect on Hall-Petch Relationship%TWIP钢的孪晶及其对Hall-Petch关系的影响

    Institute of Scientific and Technical Information of China (English)

    伍翠兰; 艾倍倍; 谢盼; 陈汪林; 李久茂

    2013-01-01

    The effect of annealing temperature on the microstructures and mechanical properties of the cold-rolled Fe-25Mn-3Al-3Si TWIP was studied by means of electron backscatter diffraction technology,transmission electron microscope and tensile test.The Hall-Petch relationship was analyzed in detail.The results have shown that the microstructure of the fully recrystallized samples consists of equiaxed grains and annealing twins.With the increase of the annealing temperature,the grain size is continuously increasing while the fraction of Σ3 grain boundaries is fluctuantly increasing.After annealed at 850 ℃ for 1 h,the Σ3 grain boundaries reach 44%.In the tensile process,the relationship of strength and grain size obeys the Hall-Petch relationship,but twin boundaries affect the slope K of the Hall-Petch relationship.The K(ε)-ε relationship of the TWIP steel is different from that of general steels at room temperature,in which K(ε) monotonically increases with the strain ε.The K(ε) of the TWIP steel increases first,then,keeps unchanged and finally decreases with the strain ε.%采用背散射电子衍射、透射电子显微镜和拉伸实验等研究了退火温度对冷轧态Fe-25Mn-3A1-3Si TWIP钢微观组织及力学性能的影响,并分析了Hall-Petch关系.结果表明,完全再结晶组织由等轴晶和退火孪晶组成,再结晶晶粒平均尺寸随退火温度的升高单调增大,∑3晶界面积分数随退火温度升高而呈现波动增加,850℃退火1h后∑3晶界面积分数达到44%.拉伸过程中强度与晶粒大小都服从Hall-Petch关系,但孪晶界影响Hall-Petch关系斜率K(ε)的大小.TWIP钢K(ε)-ε关系不同于一般钢材常温下的K(ε)随ε增加单调上升,TWIP钢K(ε)随着ε的增加逐渐增大,然后出现平台,最后下降.

  7. Duality in the quantum Hall system

    Science.gov (United States)

    Lütken, C. A.; Ross, G. G.

    1992-05-01

    We suggest that a unified description of the integer and fractional phases of the quantum Hall system may be possible if the scaling diagram of transport coefficients is invariant under linear fractional (modular) transformations. In this model the hierarchy of states, as well as the observed universality of critical exponents, are consequences of a discrete SL(2,openZ) symmetry acting on the parameter space of an effective quantum-field theory. Available scaling data on the position of delocalization fixed points in the integer case and the position of mobility fixed points in the fractional case agree with the model within experimental accuracy.

  8. Twisted CFT and bilayer Quantum Hall systems

    CERN Document Server

    Cristofano, G; Naddeo, A

    2003-01-01

    We identify the impurity interactions of the recently proposed CFT description of a bilayer Quantum Hall system at filling nu =m/(pm+2) in Mod. Phys. Lett. A 15 (2000) 1679. Such a CFT is obtained by m-reduction on the one layer system, with a resulting pairing symmetry and presence of quasi-holes. For the m=2 case boundary terms are shown to describe an impurity interaction which allows for a localized tunnel of the Kondo problem type. The presence of an anomalous fixed point is evidenced at finite coupling which is unstable with respect to unbalance and flows to a vacuum state with no quasi-holes.

  9. Hypernuclear spectroscopy program at JLab Hall C

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Osamu; Hashimoto, Osamu; Nakamura, Satoshi; Acha Quimper, Armando; Ahmidouch, Abdellah; Androic, Darko; Asaturyan, Arshak; Asaturyan, Razmik; Baker, O.; Baturin, Pavlo; Benmokhtar, Fatiha; Bosted, Peter; Carlini, Roger; Chen, X.; Christy, Michael; Cole, Leon; Danagoulian, Samuel; Daniel, AJI; Dharmawardane, Kahanawita; Egiyan, Kim; Elaasar, Mostafa; Ent, Rolf; Fenker, Howard; Fujii, Yu; Furic, Miroslav; Gan, Liping; Gaskell, David; Gasparian, Ashot; Gibson, Edward; Gueye, Paul; Halkyard, Rebekah; Honda, D.; Horn, Tanja; Hu, Bitao; Hu, S.; Hungerford, Ed; Ispiryan, Mikayel; Johnston, Kathleen; Jones, Mark; Kalantarians, Narbe; Kaneta, M.; Kato, F.; Kato, Seigo; Kawama, Daisuke; Keppel, Cynthia; Li, Ya; Luo, Wei; Mack, David; Margaryan, Amur; Marikyan, Gagik; Maruyama, Nayuta; Matsumura, Akihiko; Miyoshi, Toshinobu; Mkrtchyan, Arthur; Mkrtchyan, Hamlet; Navasardyan, Tigran; Niculescu, Gabriel; Niculescu, Maria-Ioana; Nomura, Hiroshi; Nonaka, Kenichi; Ohtani, Atsushi; Okayasu, Yuichi; Pamela, Priscilla; Perez, Naipy; Petkovic, Tomislav; Randeniya, Kapugodage; Reinhold, Joerg; Rivera Castillo, Roberto; Roche, Julie; Rodriguez, Victor; Sato, Yoshinori; Seva, Tomislav; Tang, Liguang; Simicevic, Neven; Smith, Gregory; Sumihama, Mizuki; Song, Y.; Tadevosyan, Vardan; Takahashi, Toshiyuki; Tamura, Hirokazu; Tvaskis, Vladas; Vulcan, William; Wang, B.; Wells, Steven; Yan, Chen; Yuan, Lulin; Zamkochian, S.

    2008-05-01

    DOI: http://dx.doi.org/10.1016/j.nuclphysa.2008.01.029
    Hypernuclear production by the (e,e?K+) reaction has unique advantages in hypernuclear spectroscopy of the S=?1 regime. The second-generation spectroscopy experiment on 12C, 7Li and 28Si targets has been recently carried out at JLab Hall C with a new experimental configuration (Tilt method) and also using a new high-resolution kaon spectrometer (HKS). The experiment is described and preliminary results are presented together with the empasis of significance of the (e,e?K+) reaction for ? hypernuclear spectroscopy and its future prospects.

  10. Current correlations in quantum spin Hall insulators.

    Science.gov (United States)

    Schmidt, Thomas L

    2011-08-26

    We consider a four-terminal setup of a two-dimensional topological insulator (quantum spin Hall insulator) with local tunneling between the upper and lower edges. The edge modes are modeled as helical Luttinger liquids and the electron-electron interactions are taken into account exactly. Using perturbation theory in the tunneling, we derive the cumulant generating function for the interedge current. We show that different possible transport channels give rise to different signatures in the current noise and current cross correlations, which could be exploited in experiments to elucidate the interplay between electron-electron interactions and the helical nature of the edge states.

  11. Anomalous Hall Effect in a Kagome Ferromagnet

    Science.gov (United States)

    Ye, Linda; Wicker, Christina; Suzuki, Takehito; Checkelsky, Joseph; Joseph Checkelsky Team

    The ferromagnetic kagome lattice is theoretically known to possess topological band structures. We have synthesized large single crystals of a kagome ferromagnet Fe3Sn2 which orders ferromagnetically well above room temperature. We have studied the electrical and magnetic properties of these crystals over a broad temperature and magnetic field range. Both the scaling relation of anomalous Hall effect and anisotropic magnetic susceptibility show that the ferromagnetism of Fe3Sn2 is unconventional. We discuss these results in the context of magnetism in kagome systems and relevance to the predicted topological properties in this class of compounds. This research is supported by DMR-1231319.

  12. Supercurrent in the quantum Hall regime

    Science.gov (United States)

    Amet, F.; Ke, C. T.; Borzenets, I. V.; Wang, J.; Watanabe, K.; Taniguchi, T.; Deacon, R. S.; Yamamoto, M.; Bomze, Y.; Tarucha, S.; Finkelstein, G.

    2016-05-01

    A promising route for creating topological states and excitations is to combine superconductivity and the quantum Hall (QH) effect. Despite this potential, signatures of superconductivity in the QH regime remain scarce, and a superconducting current through a QH weak link has been challenging to observe. We demonstrate the existence of a distinct supercurrent mechanism in encapsulated graphene samples contacted by superconducting electrodes, in magnetic fields as high as 2 tesla. The observation of a supercurrent in the QH regime marks an important step in the quest for exotic topological excitations, such as Majorana fermions and parafermions, which may find applications in fault-tolerant quantum computing.

  13. Novel optical probe for quantum Hall system

    Indian Academy of Sciences (India)

    Biswajit Karmakar; Brij Mohan Arora

    2006-07-01

    Surface photovoltage (SPV) spectroscopy has been used for the first time to explore Landau levels of a two-dimensional electron gas (2DEG) in modulation doped InP/InGaAs/InP QW in the quantum Hall regime. The technique gives spectroscopically distinct signals from the bulk Landau levels and the edge states. Evolution of the bulk Landau levels and the edge electronic states is investigated at 2.0 K for magnetic field up to 8 T using SPV spectroscopy.

  14. Excitons in the Fractional Quantum Hall Effect

    Science.gov (United States)

    Laughlin, R. B.

    1984-09-01

    Quasiparticles of charge 1/m in the Fractional Quantum Hall Effect form excitons, which are collective excitations physically similar to the transverse magnetoplasma oscillations of a Wigner crystal. A variational exciton wavefunction which shows explicitly that the magnetic length is effectively longer for quasiparticles than for electrons is proposed. This wavefunction is used to estimate the dispersion relation of these excitons and the matrix elements to generate them optically out of the ground state. These quantities are then used to describe a type of nonlinear conductivity which may occur in these systems when they are relatively clean.

  15. Anesthetic considerations in Sheldon-Hall syndrome.

    Science.gov (United States)

    Anderson, Thomas Anthony; Kasser, James R; Holzman, Robert S

    2014-05-01

    Arthrogryposis is characterized by multiple, nonprogressive joint contractures which may be caused by maternal disorders such as oligohydramnios as well as fetal akinesia resulting from primary disorders of muscle, connective tissue, or neurologic tissue. Its prevalence is about 1 : 3000. Distal arthrogryposis (DA) is a heterogenous group of genetic disorders with a characteristic flexion of the joints of the hands and feet divided into different types with additional features. Sheldon-Hall Syndrome (SHS), also known as distal arthrogryposis type 2A (DA2A), has some nonorthopedic features of specific importance to anesthetic care.

  16. Effect of Joule heating on current-induced asymmetries and breakdown of the quantum Hall effect in narrow Hall bars

    Science.gov (United States)

    Gerhardts, Rolf R.

    2017-01-01

    Recent low-temperature scanning-force-microscopy experiments on narrow Hall bars, under the conditions of the integer quantum Hall effect (IQHE) and its breakdown, have revealed an interesting position dependence of the Hall potential, which changes drastically with the applied magnetic field and the strength of the imposed current through the sample. The present paper shows, that inclusion of Joule heating into an existing self-consistent theory of screening and magneto-transport, which assumes translation invariant Hall bars with a homogeneous background charge due to doping, can explain the experimental results on the breakdown of the IQHE in the so called edge-dominated regime.

  17. SNTP program reactor design

    Science.gov (United States)

    Walton, Lewis A.; Sapyta, Joseph J.

    1993-06-01

    The Space Nuclear Thermal Propulsion (SNTP) program is evaluating the feasibility of a particle bed reactor for a high-performance nuclear thermal rocket engine. Reactors operating between 500 MW and 2,000 MW will produce engine thrusts ranging from 20,000 pounds to 80,000 pounds. The optimum reactor arrangement depends on the power level desired and the intended application. The key components of the reactor have been developed and are being tested. Flow-to-power matching considerations dominate the thermal-hydraulic design of the reactor. Optimal propellant management during decay heat cooling requires a three-pronged approach. Adequate computational methods exist to perform the neutronics analysis of the reactor core. These methods have been benchmarked to critical experiment data.

  18. Hybrid reactors. [Fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W.

    1980-09-09

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid.

  19. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  20. The muon system of the Daya Bay Reactor antineutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    An, F.P. [Institute of Modern Physics, East China University of Science and Technology, Shanghai (China); Institute of High Energy Physics, Beijing (China); Balantekin, A.B. [University of Wisconsin, Madison, WI (United States); Band, H.R. [Department of Physics, Yale University, New Haven, CT (United States); University of Wisconsin, Madison, WI (United States); Beriguete, W.; Bishai, M. [Brookhaven National Laboratory, Upton, NY (United States); Blyth, S. [Department of Physics, National Taiwan University, Taipei (China); National United University, Miao-Li, Taiwan (China); Brown, R.E. [Brookhaven National Laboratory, Upton, NY (United States); Butorov, I. [Joint Institute for Nuclear Research, Dubna, Moscow Region (Russian Federation); Cao, G.F.; Cao, J. [Institute of High Energy Physics, Beijing (China); Carr, R. [California Institute of Technology, Pasadena, CA (United States); Chan, Y.L. [Chinese University of Hong Kong (Hong Kong); Chang, J.F. [Institute of High Energy Physics, Beijing (China); Chang, L. [Institute of Physics, National Chiao-Tung University, Hsinchu, Taiwan (China); Chang, Y. [National United University, Miao-Li, Taiwan (China); Chasman, C. [Brookhaven National Laboratory, Upton, NY (United States); Chen, H.S. [Institute of High Energy Physics, Beijing (China); Chen, H.Y. [Institute of Physics, National Chiao-Tung University, Hsinchu, Taiwan (China); Chen, Q.Y. [Shandong University, Jinan (China); Chen, S.J. [Nanjing University, Nanjing (China); and others

    2015-02-11

    The Daya Bay experiment consists of functionally identical antineutrino detectors immersed in pools of ultrapure water in three well-separated underground experimental halls near two nuclear reactor complexes. These pools serve both as shields against natural, low-energy radiation, and as water Cherenkov detectors that efficiently detect cosmic muons using arrays of photomultiplier tubes. Each pool is covered by a plane of resistive plate chambers as an additional means of detecting muons. Design, construction, operation, and performance of these muon detectors are described.

  1. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kanbe, Mitsuru

    1997-04-04

    An LMFBR type reactor comprises a plurality of reactor cores in a reactor container. Namely, a plurality of pot containing vessels are disposed in the reactor vessel and a plurality of reactor cores are formed in a state where an integrated-type fuel assembly is each inserted to a pot, and a coolant pipeline is connected to each of the pot containing-vessel to cool the reactor core respectively. When fuels are exchanged, the integrated-type fuel assembly is taken out together with the pot from the reactor vessel in a state where the integrated-type fuel assembly is immersed in the coolants in the pot as it is. Accordingly, coolants are supplied to each of the pot containing-vessel connected with the coolant pipeline and circulate while cooling the integrated-type fuel assembly for every pot. Then, when the fuels are exchanged, the integrated type fuel assembly is taken out to the outside of the reactor together with the pot by taking up the pot from the pot-containing vessel. Then, neutron economy is improved to thereby improve reactor power and the breeding ratio. (N.H.)

  2. INVAP's Research Reactor Designs

    Directory of Open Access Journals (Sweden)

    Eduardo Villarino

    2011-01-01

    Full Text Available INVAP, an Argentine company founded more than three decades ago, is today recognized as one of the leaders within the research reactor industry. INVAP has participated in several projects covering a wide range of facilities, designed in accordance with the requirements of our different clients. For complying with these requirements, INVAP developed special skills and capabilities to deal with different fuel assemblies, different core cooling systems, and different reactor layouts. This paper summarizes the general features and utilization of several INVAP research reactor designs, from subcritical and critical assemblies to high-power reactors.

  3. Multi purpose research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Raina, V.K. [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)]. E-mail: vkrain@magnum.barc.ernet.in; Sasidharan, K. [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sengupta, Samiran [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Singh, Tej [Research Reactor Services Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2006-04-15

    At present Dhruva and Cirus reactors provide the majority of research reactor based facilities to cater to the various needs of a vast pool of researchers in the field of material sciences, physics, chemistry, bio sciences, research and development work for nuclear power plants and production of radio isotopes. With a view to further consolidate and expand the scope of research and development in nuclear and allied sciences, a new 20 MWt multi purpose research reactor is being designed. This paper describes some of the design features and safety aspects of this reactor.

  4. Intrinsic valley Hall effect in graphene

    Science.gov (United States)

    Yang, Mou; Zhang, Wen-Lian; Liu, Hai; Bai, Yan-Kui

    2017-04-01

    If electrons are incident from an armchair graphene ribbon into the bulk graphene region, the electronic diffraction occurs. Because of the different triangular wrapping of the energy dispersion between valleys K and K ‧ , the electrons of valley K tend to be diffracted to one side and those of valley K ‧ to the other side. When the current is injected from the armchair ribbon of a four-terminal graphene device, the major portion of the incident current of valley K flows through one side arm and the minor portion through the other side arm. The ratio between them is derived to be 1 + 4 E / 3 in the low energy limit, where E is the energy in units of hopping parameter. The major arm for valley K is the minor arm for valley K ‧ . This results in the rise of the valley Hall effect, which is an intrinsic property of graphene stemming from the different electronic structure of the two valleys. The valley Hall conductance is calculated to be (2 E / 3)G0 with G0 being the conductance supported by the injection ribbon.

  5. Repurposing the Caltech Robinson Hall Coelostat

    Science.gov (United States)

    Treffers, Richard R.; Loisos, G.; Ubbelohde, M.; Douglas, S.; Martinez, M.

    2013-01-01

    We describe the repurposing of the historic coelostat atop Caltech’s Robinson Hall for building lighting, public education and scientific research. The coelostat was originally part of George Ellery Hale’s vision of the Astrophysical Laboratory on the Caltech campus in 1932. The coelostat, designed by Russell Porter, has a 36 inch diameter primary mirror a 30 inch diameter secondary mirror and provides a 24 inch un-vignetted beam of sunlight into the building. Although constructed in the 1930s, due to wartime pressures and other projects, it was used only briefly in the 1970s and never fully realized. Recently Robinson Hall has been fully renovated to house the Ronald and Maxine Linde Center for Global Environmental Science. The coelostat operation was modernized replacing the old motors and automating all the motions. Each morning, if the weather cooperates, the dome slit opens, the mirrors configured and sunlight pours into the building. The beam of sunlight is divided into three parts. One part goes into a refracting telescope which projects a ten inch diameter of the sun onto a ground glass screen visible to the public. A second fraction is distributed to fiber optic fixtures that illuminate some of the basement rooms. The final fraction goes into two laboratories where it is used in experiments monitoring trace constituents of our atmosphere and for solar catalysis experiments. The instrument as originally conceived required at least two human operators. Now it is fully automatic and doing real science

  6. Plume Comparisons between Segmented Channel Hall Thrusters

    Science.gov (United States)

    Niemack, Michael; Staack, David; Raitses, Yevgeny; Fisch, Nathaniel

    2001-10-01

    Angular ion flux plume measurements were taken in several configurations of segmented channel Hall thrusters. The configurations differed by the placement of relatively short rings made from materials with different conductive and secondary electron emission properties along the boron nitride ceramic channel of the thrusters (these have been shown to affect the plume [1]). The ion fluxes are compared with ion trajectory simulations based on plasma potential data acquired with a high speed emissive probe [2]. Preliminary results indicate that in addition to the physical properties of the segments, the plume angle can be strongly affected by the placement of segmented rings relative to the external and internal walls of the channel. [1] Y. Raitses, L. Dorf, A. Litvak and N. J. Fisch, Journal of Applied Physics 88, 1263, 2000 [2] D. Staack, Y. Raitses, N. J. Fisch, Parametric Investigations of Langmuir Probe Induced Perturbations in a Hall Thruster, DPP01 Poster Presentation This work was supported by the U.S. DOE Contract No. DE-ACO2-76-CHO3073.

  7. Radiation heating in sports halls. Stralingsverwarming in sporthallen

    Energy Technology Data Exchange (ETDEWEB)

    Blokpoel, L.

    1994-03-01

    The aim of the study on the title subject was to determine whether by means of the application of radiation heating the required level of thermal comfort in sporting halls can be realized and how much energy is needed to realize such comfort. In two sporting halls the air heating installation was replaced by a radiant heating system. In the sports hall 'D'n Treffer' in Maasbree, Netherlands, infrared radiators were installed, and in the sports hall 'de Taxandriahal' in Waalwijk, Netherlands, so-called dark radiators were installed. After a brief introduction on how to define and quantify thermal comfort, measured results for both sporting halls are presented and discussed. Also the results of a survey among the users of the sporting halls to determine their opinion on the thermal comfort in the halls are presented. The survey was carried out by the authority that commissioned this study, The Dutch National Sports Federation (NSF). In general it can be concluded that radiation heating is a well applicable heating system for sports halls. 17 figs., 8 ills., 10 tabs., 8 appendices

  8. A Larger Scale. Tenth Annual Residence Hall Construction Report.

    Science.gov (United States)

    Argon, Joe

    1999-01-01

    Presents data from the American School & University's 10th Annual Residence Hall Construction Report that show dormitories are costing more per square foot to build while also becoming larger accommodations. Data tables are provided as are highlighted discussions that include residence hall design flexibility, environmental concerns and building…

  9. The first vineyard concert hall in North America

    Science.gov (United States)

    Jaffe, Christopher; Rivera, Carlos

    2002-11-01

    The first vineyard or surround concert hall designed and built in the Western Hemisphere is the Sala Nezahualcoyotl in Mexico City. The Hall was completed in 1976 and is part of the Cultural Center at the Universidad Nacional Autonoma de Mexico. The hall was named after a Toltec poet, architect, and musician who lived in the 15th century and was the Renaissance man of his day. In order to provide the familiar traditional sound of the rectangular (shoebox) European Hall, the acoustic designers set the criteria for reverberation times through the frequency spectrum and the Initial Time Delay Gap at every seat in the house to match the measurements taken at the Grosser Musik vereinssaal in Vienna and Boston Symphony Hall. In this paper we discuss the techniques used to create the traditional sound in a vineyard hall and the reaction of musicians and audiences to the completed facility. The Sala was the model for Suntory Hall in Japan which in turn spawned a number of vineyard halls in Japan. Most recently, the vineyard style seems to be appealing to more and more symphonic organizations in Europe and North America.

  10. Stuart Hall on Racism and the Importance of Diasporic Thinking

    Science.gov (United States)

    Rizvi, Fazal

    2015-01-01

    In this article, I want to show how my initial encounter with the work of Stuart Hall was grounded in my reading of the later philosophy of Ludwig Wittgenstein, and was shaped by my interest in understanding the nature of racism across the three countries in which I had lived. Over the years, Hall's various writings have helped me to make sense of…

  11. Acoustic investigations of concert halls for rock music

    DEFF Research Database (Denmark)

    Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    Objective measurement data and subjective evaluations have been collected from 20 small-/medium-sized halls in Denmark used for amplified rhythmic music concerts (pop, rock, jazz). The purpose of the study was to obtain knowledge about optimum acoustic conditions for this type of hall. The study...

  12. Cultural Composition: Stuart Hall on Ethnicity and the Discursive Turn.

    Science.gov (United States)

    Drew, Julie

    1998-01-01

    Interviews Stuart Hall, a black public intellectual and an activist of the New Left. Discusses the growing disillusionment with cultural studies now that it is no longer in its ascendancy; the proliferation of pedagogical practices given a cultural studies tag; Hall's approval of the use of popular culture in the composition classroom; and the…

  13. Stuart Hall on Racism and the Importance of Diasporic Thinking

    Science.gov (United States)

    Rizvi, Fazal

    2015-01-01

    In this article, I want to show how my initial encounter with the work of Stuart Hall was grounded in my reading of the later philosophy of Ludwig Wittgenstein, and was shaped by my interest in understanding the nature of racism across the three countries in which I had lived. Over the years, Hall's various writings have helped me to make sense of…

  14. Pair spectrometer hodoscope for Hall D at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, F.; Hutton, C.; Sitnikov, A. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Somov, A., E-mail: somov@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Somov, S.; Tolstukhin, I. [National Research Nuclear University MEPhI, Moscow (Russian Federation)

    2015-09-21

    We present the design of the pair spectrometer hodoscope fabricated at Jefferson Lab and installed in the experimental Hall D. The hodoscope consists of thin scintillator tiles; the light from each tile is collected using wave-length shifting fibers and detected using a Hamamatsu silicon photomultiplier. Light collection was measured using relativistic electrons produced in the tagger area of the experimental Hall B.

  15. Mary E. Hall: Dawn of the Professional School Librarian

    Science.gov (United States)

    Alto, Teresa

    2012-01-01

    A century ago, a woman named Mary E. Hall convinced school leaders of the need for the professional school librarian--a librarian who cultivated a love of reading, academic achievement, and independent learning skills. After graduating from New York City's Pratt Institute Library School in 1895, Hall developed her vision for the high school…

  16. Varsity Hall: The Infirmary at the University of Virginia

    Science.gov (United States)

    Christmas, William A.; Turner, James C.

    2008-01-01

    In the past 5 years, an important treasure for the field of college health was rediscovered and has been completely renovated. It is the original student infirmary, now called Varsity Hall, at the University of Virginia in Charlottesville. Varsity Hall is a significant rediscovery for those who are interested in the history of college health. This…

  17. Useful Pedagogical Applications of the Classical Hall Effect

    Science.gov (United States)

    Houari, Ahmed

    2007-01-01

    One of the most known phenomena in physics is the Hall effect. This is mainly due to its simplicity and to the wide range of its theoretical and practical applications. To complete the pedagogical utility of the Hall effect in physics teaching, I will apply it here to determine the Faraday constant as a fundamental physical number and the number…

  18. Spatial sensitivity mapping of Hall crosses using patterned magnetic nanostructures

    NARCIS (Netherlands)

    Alexandrou, M.; Nutter, P.W.; Delalande, M.Y.; Vries, de J.; Hill, E.W.; Schedin, F.; Abelmann, L.; Thomson, T.

    2010-01-01

    Obtaining an accurate profile of the spatial sensitivity of Hall cross structures is crucial if such devices are to be used to analyze the switching behavior of magnetic nanostructures and determine the switching field distribution of bit patterned media. Here, we have used the anomalous Hall effect

  19. Bulk Versus Edge in the Quantum Hall Effect

    OpenAIRE

    Kao, Y. -C.; Lee, D.-H.

    1996-01-01

    The manifestation of the bulk quantum Hall effect on edge is the chiral anomaly. The chiral anomaly {\\it is} the underlying principle of the ``edge approach'' of quantum Hall effect. In that approach, $\\sxy$ should not be taken as the conductance derived from the space-local current-current correlation function of the pure one-dimensional edge problem.

  20. Efecto Hall del In en Película Evaporada

    OpenAIRE

    Herrera de Camboa, María Elena

    2015-01-01

    El efecto Hall demostrado por Edwin Herbert Hall (1) en 1879 ha venido a ser un hecho importante para la comprension del coruportamiento de los portadores de carga en la conduccion electrica. Es por esto que es necesario investigar este fenomeno en Ia Física del Estado Solido en los diferentes solidos.

  1. Fractional quantum Hall states of bosons on cones

    Science.gov (United States)

    Wu, Ying-Hai; Tu, Hong-Hao; Sreejith, G. J.

    2017-09-01

    Motivated by a recent experiment, which synthesizes Landau levels for photons on cones [Schine et al., Nature (London) 534, 671 (2016), 10.1038/nature17943], and more generally the interest in understanding gravitational responses of quantum Hall states, we study fractional quantum Hall states of bosons on cones. A variety of trial wave functions for conical systems are constructed and compared with exact diagonalization results. The tip of a cone is a localized geometrical defect with singular curvature, which can modify the density profiles of quantum Hall states. The density profiles on cones can be used to extract some universal information about quantum Hall states. The values of certain quantities are computed numerically using the density profiles of some quantum Hall states and they agree with analytical predictions.

  2. Construction and Operation of a Differential Hall Element Magnetometer

    Science.gov (United States)

    Calkins, Matthew W.; Javernick, Philip D.; Quintero, Pedro A.; Calm, Yitzi M.; Meisel, Mark W.

    2012-02-01

    A Differential Hall Element Magnetometer (DHEM) was constructed to measure the magnetic saturation and coercive fields of small samples consisting of magnetic nanoparticles that may have biomedical applications. The device consists of two matched Hall elements that can be moved through the room temperature bore of a 9 Tesla superconducting magnet. The Hall elements are wired in opposition such that a null response, to within a small offset, is measured in the absence of a sample that may be located on top of one unit. A LabVIEW program controls the current through the Hall elements and measures the net Hall voltage while simultaneously moving the probe through the magnetic field by regulating a linear stepper motor. Ultimately, the system will be tested to obtain a figure of merit using successively smaller samples. Details of the apparatus will be provided along with preliminary data.

  3. Topological insulator in junction with ferromagnets: Quantum Hall effects

    Science.gov (United States)

    Chudnovskiy, A. L.; Kagalovsky, V.

    2015-06-01

    The ferromagnet-topological insulator-ferromagnet (FM-TI-FM) junction exhibits thermal and electrical quantum Hall effects. The generated Hall voltage and transverse temperature gradient can be controlled by the directions of magnetizations in the FM leads, which inspires the use of FM-TI-FM junctions as electrical and as heat switches in spintronic devices. Thermal and electrical Hall coefficients are calculated as functions of the magnetization directions in ferromagnets and the spin-relaxation time in TI. Both the Hall voltage and the transverse temperature gradient decrease but are not completely suppressed even at very short spin-relaxation times. The Hall coefficients turn out to be independent of the spin-relaxation time for symmetric configuration of FM leads.

  4. Quantum Hall effect in kagome lattices under staggered magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhiyong, E-mail: zyzhang@nju.edu.cn [Department of Physics, Nanjing University, Nanjing 210093 (China)

    2011-10-26

    The interplay of staggered magnetic field (SMF) and uniform magnetic field (UMF) on the quantum Hall effect (QHE) in kagome lattices is investigated in the weak UMF limit. The topological band gaps coming from SMF are robust against UMF although the extended bands split into a series of Landau levels. With SMF applied, in the unconventional QHE region, one plateau of Hall conductance becomes wider and the others are compressed. Meanwhile, one of the two series of integer Hall plateaus splits and the resulting two series of Hall plateaus still exhibit the integer behavior. The Hall conductance varies with SMF step by step with the step height being e{sup 2}/h or 2e{sup 2}/h according to the QHE being conventional or unconventional. In the transitional regions, redistribution of Chern numbers happens even in the weak UMF limit. (paper)

  5. Unconventional quantum Hall effect in Floquet topological insulators

    KAUST Repository

    Tahir, M.

    2016-07-27

    We study an unconventional quantum Hall effect for the surface states of ultrathin Floquet topological insulators in a perpendicular magnetic field. The resulting band structure is modified by photon dressing and the topological property is governed by the low-energy dynamics of a single surface. An exchange of symmetric and antisymmetric surface states occurs by reversing the lights polarization. We find a novel quantum Hall state in which the zeroth Landau level undergoes a phase transition from a trivial insulator state, with Hall conductivity αyx = 0 at zero Fermi energy, to a Hall insulator state with αyx = e2/2h. These findings open new possibilities for experimentally realizing nontrivial quantum states and unusual quantum Hall plateaus at (±1/2,±3/2,±5/2, ...)e2/h. © 2016 IOP Publishing Ltd Printed in the UK.

  6. Axisymmetric Nonlinear Waves And Structures in Hall Plasmas

    CERN Document Server

    Islam, Tanim

    2011-01-01

    A Hall plasma consists of a plasma with not all species frozen into the magnetic field. In this paper, a general equation for the evolution of an axisymmetric magnetic field in a Hall plasma is derived, with an integral similar to the Grad-Shafranov equation. Special solutions arising from curvature -- whistler drift modes that propagate along the electron drift as a Burger's shock, and nonlinear periodic and soliton-like solutions to the generalized Grad-Shafranov integral -- are analyzed. We derive analytical and numerical solutions in an electron-ion Hall plasma, in which electrons and ions are the only species in the plasmas. Results may then be applied to electron-ion-gas Hall plasmas, in which the ions are coupled to the motion of gases in low ionized plasmas (lower ionosphere and protostellar disks), and to dusty Hall plasmas (such as molecular clouds), in which the much heavier charged dust may be collisionally coupled to the gas.

  7. Experimental evidence for a two-dimensional quantized Hall insulator

    Science.gov (United States)

    Hilke, M.; Shahar, D.; Song, S. H.; Tsui, D. C.; Xie, Y. H.; Monroe, Don

    1998-10-01

    The general theoretical definition of an insulator is a material in which the conductivity vanishes at the absolute zero of temperature. In classical insulators, such as materials with a band gap, vanishing conductivities lead to diverging resistivities. But other insulators can show more complex behaviour, particularly in the presence of a high magnetic field, where different components of the resistivity tensor can display different behaviours: the magnetoresistance diverges as the temperature approaches absolute zero, but the transverse (Hall) resistance remains finite. Such a system is known as a Hall insulator. Here we report experimental evidence for a quantized Hall insulator in a two-dimensional electron system-confined in a semiconductor quantum well. The Hall resistance is quantized in the quantum unit of resistance h/e2, where h is Planck's constant and e the electronic charge. At low fields, the sample reverts to being a normal Hall insulator.

  8. Geometric spin Hall effect of light with inhomogeneous polarization

    Science.gov (United States)

    Ling, Xiaohui; Zhou, Xinxing; Yi, Xunong

    2017-01-01

    The spin Hall effect of light originates from spin-orbit interaction of light, which manifests two types of geometric phases. In this paper, we report the observation of a geometric spin Hall effect by generating a light beam with inhomogeneous polarization distribution. Unlike the previously reported geometric spin Hall effect observed in a tilted beam-detector system, which is believed to result from an effective spin-redirection Berry geometric phase, the geometric spin Hall effect demonstrated here is attributed to an effective, spatially varying Pancharatnam-Berry geometric phase generated by the inhomogeneous polarization geometry. Our further experiments show that the geometric spin Hall effect can be tuned by tailoring the polarization geometry of light, demonstrating the spin states of photons can be steered with a great flexibility.

  9. In-plane magnetization-induced quantum anomalous Hall effect.

    Science.gov (United States)

    Liu, Xin; Hsu, Hsiu-Chuan; Liu, Chao-Xing

    2013-08-23

    The quantum Hall effect can only be induced by an out-of-plane magnetic field for two-dimensional electron gases, and similarly, the quantum anomalous Hall effect has also usually been considered for systems with only out-of-plane magnetization. In the present work, we predict that the quantum anomalous Hall effect can be induced by in-plane magnetization that is not accompanied by any out-of-plane magnetic field. Two realistic two-dimensional systems, Bi2Te3 thin film with magnetic doping and HgMnTe quantum wells with shear strains, are presented and the general condition for the in-plane magnetization-induced quantum anomalous Hall effect is discussed based on the symmetry analysis. Nonetheless, an experimental setup is proposed to confirm this effect, the observation of which will pave the way to search for the quantum anomalous Hall effect in a wider range of materials.

  10. Unconventional quantum Hall effect in Floquet topological insulators.

    Science.gov (United States)

    Tahir, M; Vasilopoulos, P; Schwingenschlögl, U

    2016-09-28

    We study an unconventional quantum Hall effect for the surface states of ultrathin Floquet topological insulators in a perpendicular magnetic field. The resulting band structure is modified by photon dressing and the topological property is governed by the low-energy dynamics of a single surface. An exchange of symmetric and antisymmetric surface states occurs by reversing the light's polarization. We find a novel quantum Hall state in which the zeroth Landau level undergoes a phase transition from a trivial insulator state, with Hall conductivity [Formula: see text] at zero Fermi energy, to a Hall insulator state with [Formula: see text]. These findings open new possibilities for experimentally realizing nontrivial quantum states and unusual quantum Hall plateaus at [Formula: see text].

  11. Formulation of the Relativistic Quantum Hall Effect and "Parity Anomaly"

    CERN Document Server

    Yonaga, Kouki; Shibata, Naokazu

    2016-01-01

    We present a relativistic formulation of the quantum Hall effect on a Riemann sphere. An explicit form of the pseudopotential is derived for the relativistic quantum Hall effect with/without mass term.We clarify particular features of the relativistic quantum Hall states with use of the exact diagonalization study of the pseudopotential Hamiltonian. Physical effects of the mass term to relativistic quantum Hall states are investigated in detail.The mass term acts as an interporating parameter between the relativistic and non-relativistic quantum Hall effects. It is pointed out that the mass term inequivalently affects to many-body physics of the positive and negative Landau levels and brings instability of the Laughlin state of the positive first relativistic Landau level as a consequence of the "parity anomaly".

  12. A fully integrated GaAs-based three-axis Hall magnetic sensor exploiting self-positioned strain released structures

    Science.gov (United States)

    Todaro, Maria T.; Sileo, Leonardo; Epifani, Gianmichele; Tasco, Vittorianna; Cingolani, Roberto; De Vittorio, Massimo; Passaseo, Adriana

    2010-10-01

    In this work, we demonstrate a fully integrated three-axis Hall magnetic sensor by exploiting microfabrication technologies applied to a GaAs-based heterostructure. This allows us to obtain, by the same process, three mutually orthogonal sensors: an in-plane Hall sensor and two out-of-plane Hall sensors. The micromachined devices consist of a two-dimensional electron gas AlGaAs/InGaAs/GaAs multilayer which represents the sensing structure, grown on the top of an InGaAs/GaAs strained bilayer. After the release from the substrate, the strained bilayer acts as a hinge for the multilayered structure allowing the out-of-plane self-positioning of devices. Both the in-plane and out-of-plane Hall sensors show a linear response versus the magnetic field with a sensitivity for current-biased devices higher than 1000 V A-1 T-1, corresponding to an absolute sensitivity more than 0.05 V T-1 at 50 µA. Moreover, Hall voltage measurements, as a function of the mechanical angle for both in-plane and out-of-plane sensors, demonstrate the potential of such a device for measurements of the three vector components of a magnetic field.

  13. [University residence halls: socialization processes and drug consumption].

    Science.gov (United States)

    Laranjo, Thais Helena Mourão; Soares, Cássia Baldini

    2006-12-01

    To investigate and analyze the discourse of students living in university residence halls regarding socialization processes and drug consumption. This was qualitative research among 20 undergraduate students living in university residence halls in the city of São Paulo, Brazil, in 2003. Residence halls were taken to be socialization spaces for young people that enable the presence of low-income students at university. The interviews covered students' knowledge of the history of the residence hall, their experience of living in student residences and their perceptions regarding drug consumption. The methodological procedure that served as the basis for collection, organization and analysis of the interview data was examination of the collective discourse of the subjects. It was shown that the students had little knowledge of the history of the residence hall; solutions for problems they faced in the residence hall were sought individually; and the two main concepts observed among the people living there for preventing drug consumption were war on drugs and damage limitation. It was seen that there was a negative view regarding student residence halls that related to the constant publication of disturbing events and lack of knowledge of the importance of residence halls for enabling poor students to remain at university. In the opinion of the people living in student residence halls, such accommodation enables access to university, despite the difficulties in living together and in administration by the university. With regard to the use of drugs in the residence hall, some of the people living there emphasized the need for less tolerance towards drug consumption, while others stressed the importance of educational work, particularly among those who are just starting to live there.

  14. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2001-04-01

    The activities of the Reactor Materials Research Department of the Belgian Nuclear Research Centre SCK-CEN in 2000 are summarised. The programmes within the department are focussed on studies concerning (1) fusion, in particular mechanical testing; (2) Irradiation Assisted Stress Corrosion Cracking (IASCC); (3) nuclear fuel; and (4) Reactor Pressure Vessel Steel (RPVS)

  15. Space Nuclear Reactor Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Poston, David Irvin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-06

    We needed to find a space reactor concept that could be attractive to NASA for flight and proven with a rapid turnaround, low-cost nuclear test. Heat-pipe-cooled reactors coupled to Stirling engines long identified as the easiest path to near-term, low-cost concept.

  16. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  17. Analysis of the radiometric survey during the Argonauta reactor operation; Analise do levantamento radiometrico durante operacao do reator Argonauta

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Eara de S.L.; Cardozo, Katia K.M.; Silva, Joao Carlos P.; Santos, Joao Regis dos, E-mail: esluz@ien.gov.br, E-mail: cardozo@ien.gov.br, E-mail: jcarlos@ien.gov.br, E-mail: regis@ien.gov.br [Instituto de Engenharia Nuclear (CNEN-IEN/RJ), Rio de Janeiro - RJ (Brazil)

    2013-07-01

    The Argonaut reactor at the Institute of Nuclear Engineering-IEN/CNEN, operates normally, the powers between 1.7 and 340 W on neutrongraphy procedures, production of radionuclides and experimental reactor physics lessons to postgraduate courses. The doses from neutrons and gamma radiation are measured when the reactor is critical, inside the reactor hall and surrounding regions. A study of the data obtained was performed to evaluate the daily need of this survey in the reactor hall. Taking into account the principle ALARA, which aims to optimize and minimize the dose received by the individual, we propose, in this work, through an analysis of the acquired data in occupational radiometric surveys, a reformulation of the area monitoring routine practiced by the team of radiological protection of the Institute of Nuclear Engineering - IEN/CNEN-RJ, whereas other monitoring routines regarding the radiological protection are also applied in the routine of the reactor. The operations under review occurred with the reactor operating 340 W power at intervals of 60, 120 and 180 minutes, in monitoring points in controlled areas, supervised and free. The results showed significant dose values in the output of the J-Channel 9 when the operation occurs with this open. With 180 minutes of operation, the measured values of dose rate were lower than the values at 60 min and 120 operations min. At the point in the supervised area, offsite to the reactor hall, situated in the direction of the J-Channel 9, the value reduces more than 14% in any operating time in relation to the dose rate measured at the point opposite the canal. There is a 50% reduction in the dose rates for operations with and J-9 closed. The results suggest a new frequency of radiometric survey whose mode of operation is maintained in similar conditions, since combined with other relevant practices of radiation protection.

  18. Phenomenology and sign change of the Hall resistivity near the superconducting transition of polycrystalline DyBa{sub 2}Cu{sub 3}O{sub 7-{delta}}

    Energy Technology Data Exchange (ETDEWEB)

    Roa-Rojas, J. [Rio Grande do Sul Univ., Porto Alegre (Brazil). Inst. de Fisica; Escuela Colombiana de Ingenieria, Santafe de Bogota (Colombia); Landinez Tellez, D.A. [Pernambuco Univ., Recife (Brazil). Dept. de Fisica; Pureur, P. [Rio Grande do Sul Univ., Porto Alegre (Brazil). Inst. de Fisica

    2000-07-01

    Measurements of the temperature dependence of the electrical resistivity and the Hall effect in the normal and superconducting states of a ceramic DyBa{sub 2}Cu{sub 3}O{sub 7-{delta}} superconductor are reported. In high temperatures the diagonal resistivity is proportional to T, whereas the Hall response exhibits a 1/T dependence and the cotangent of the Hall angle is proportional to T{sup 2}. Upon decreasing the temperature, the Hall response shows a sign reversal close to T{sub c}, goes through a negative maximum and vanishes close to the so-called zero-resistance temperature. The aim of this report is to show that the sign change occurs in the temperature region dominated by thermal fluctuations in the order parameter. (orig.)

  19. Status of French reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ballagny, A. [Commissariat a l`Energie Atomique, Saclay (France)

    1997-08-01

    The status of French reactors is reviewed. The ORPHEE and RHF reactors can not be operated with a LEU fuel which would be limited to 4.8 g U/cm{sup 3}. The OSIRIS reactor has already been converted to LEU. It will use U{sub 3}Si{sub 2} as soon as its present stock of UO{sub 2} fuel is used up, at the end of 1994. The decision to close down the SILOE reactor in the near future is not propitious for the start of a conversion process. The REX 2000 reactor, which is expected to be commissioned in 2005, will use LEU (except if the fast neutrons core option is selected). Concerning the end of the HEU fuel cycle, the best option is reprocessing followed by conversion of the reprocessed uranium to LEU.

  20. Nuclear reactor design

    CERN Document Server

    2014-01-01

    This book focuses on core design and methods for design and analysis. It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and high-temperature gas-cooled reactors. The objectives of this book are to help graduate and advanced undergraduate students to understand core design and analysis, and to serve as a background reference for engineers actively working in light water reactors. Methodologies for core design and analysis, together with physical descriptions, are emphasized. The book also covers coupled thermal hydraulic core calculations, plant dynamics, and safety analysis, allowing readers to understand core design in relation to plant control and safety.

  1. Mirror reactor surface study

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A. L.; Damm, C. C.; Futch, A. H.; Hiskes, J. R.; Meisenheimer, R. G.; Moir, R. W.; Simonen, T. C.; Stallard, B. W.; Taylor, C. E.

    1976-09-01

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included.

  2. Design Considerations for CMOS-Integrated Hall-Effect Magnetic Bead Detectors for Biosensor Applications.

    Science.gov (United States)

    Skucha, K; Gambini, S; Liu, P; Megens, M; Kim, J; Boser, Be

    2013-06-05

    We describe a design methodology for on-chip magnetic bead label detectors based on Hall-effect sensors. Signal errors caused by the label-binding process and other factors that limit the minimum detection area are quantified and adjusted to meet typical assay accuracy standards. The methodology is demonstrated by designing an 8192 element Hall sensor array, implemented in a commercial 0.18 μm CMOS process with single-mask postprocessing. The array can quantify a 1% surface coverage of 2.8 μm beads in 30 seconds with a coefficient of variation of 7.4%. This combination of accuracy and speed makes this technology a suitable detection platform for biological assays based on magnetic bead labels.

  3. Phase Space for the Breakdown of the Quantum Hall Effect in Epitaxial Graphene

    Science.gov (United States)

    Alexander-Webber, J. A.; Baker, A. M. R.; Janssen, T. J. B. M.; Tzalenchuk, A.; Lara-Avila, S.; Kubatkin, S.; Yakimova, R.; Piot, B. A.; Maude, D. K.; Nicholas, R. J.

    2013-08-01

    We report the phase space defined by the quantum Hall effect breakdown in polymer gated epitaxial graphene on SiC (SiC/G) as a function of temperature, current, carrier density, and magnetic fields up to 30 T. At 2 K, breakdown currents (Ic) almost 2 orders of magnitude greater than in GaAs devices are observed. The phase boundary of the dissipationless state (ρxx=0) shows a [1-(T/Tc)2] dependence and persists up to Tc>45K at 29 T. With magnetic field Ic was found to increase ∝B3/2 and Tc∝B2. As the Fermi energy approaches the Dirac point, the ν=2 quantized Hall plateau appears continuously from fields as low as 1 T up to at least 19 T due to a strong magnetic field dependence of the carrier density.

  4. Magneto-Optical Detection of the Spin Hall Effect in Pt and W Thin Films

    Science.gov (United States)

    Stamm, C.; Murer, C.; Berritta, M.; Feng, J.; Gabureac, M.; Oppeneer, P. M.; Gambardella, P.

    2017-08-01

    The conversion of charge currents into spin currents in nonmagnetic conductors is a hallmark manifestation of spin-orbit coupling that has important implications for spintronic devices. Here we report the measurement of the interfacial spin accumulation induced by the spin Hall effect in Pt and W thin films using magneto-optical Kerr microscopy. We show that the Kerr rotation has opposite sign in Pt and W and scales linearly with current density. By comparing the experimental results with ab initio calculations of the spin Hall and magneto-optical Kerr effects, we quantitatively determine the current-induced spin accumulation at the Pt interface as 5 ×10-12 μB A-1 cm2 per atom. From thickness-dependent measurements, we determine the spin diffusion length in a single Pt film to be 11 ±3 nm , which is significantly larger compared to that of Pt adjacent to a magnetic layer.

  5. Geometric Photonic Spin Hall Effect with Metapolarization

    CERN Document Server

    Ling, Xiaohui; Yi, Xunong; Luo, Hailu; Wen, Shuangchun

    2014-01-01

    We develop a geometric photonic spin Hall effect (PSHE) which manifests as spin-dependent shift in momentum space. It originates from an effective space-variant Pancharatnam-Berry (PB) phase created by artificially engineering the polarization distribution of the incident light. Unlikely the previously reported PSHE involving the light-matter interaction, the resulting spin-dependent splitting in the geometric PSHE is purely geometrically depend upon the polarization distribution of light which can be tailored by assembling its circular polarization basis with suitably magnitude and phase. This metapolarization idea enables us to manipulate the geometric PSHE by suitably tailoring the polarization geometry of light. Our scheme provides great flexibility in the design of various polarization geometry and polarization-dependent application, and can be extrapolated to other physical system, such as electron beam or atom beam, with the similar spin-orbit coupling underlying.

  6. Photonic analogue of quantum spin Hall effect

    CERN Document Server

    He, Cheng; Liu, Xiao-ping; Lu, Ming-Hui; Chen, Yulin; Feng, Liang; Chen, Yan-Feng

    2014-01-01

    Symmetry-protected photonic topological insulator exhibiting robust pseudo-spin-dependent transportation, analogous to quantum spin Hall (QSH) phases and topological insulators, are of great importance in fundamental physics. Such transportation robustness is protected by time-reversal symmetry. Since electrons (fermion) and photons (boson) obey different statistics rules and associate with different time-reversal operators (i.e., Tf and Tb, respectively), whether photonic counterpart of Kramers degeneracy is topologically protected by bosonic Tb remains unidentified. Here, we construct the degenerate gapless edge states of two photonic pseudo-spins (left/right circular polarizations) in the band gap of a two-dimensional photonic crystal with strong magneto-electric coupling. We further demonstrated that the topological edge states are in fact protected by Tf rather than commonly believed Tb and their pseudo-spin dependent transportation is robust against Tf invariant impurities, discovering for the first tim...

  7. Gauge Physics of Spin Hall Effect

    Science.gov (United States)

    Tan, Seng Ghee; Jalil, Mansoor B. A.; Ho, Cong Son; Siu, Zhuobin; Murakami, Shuichi

    2015-12-01

    Spin Hall effect (SHE) has been discussed in the context of Kubo formulation, geometric physics, spin orbit force, and numerous semi-classical treatments. It can be confusing if the different pictures have partial or overlapping claims of contribution to the SHE. In this article, we present a gauge-theoretic, time-momentum elucidation, which provides a general SHE equation of motion, that unifies under one theoretical framework, all contributions of SHE conductivity due to the kinetic, the spin orbit force (Yang-Mills), and the geometric (Murakami-Fujita) effects. Our work puts right an ambiguity surrounding previously partial treatments involving the Kubo, semiclassical, Berry curvatures, or the spin orbit force. Our full treatment shows the Rashba 2DEG SHE conductivity to be instead of -, and Rashba heavy hole instead of -. This renewed treatment suggests a need to re-derive and re-calculate previously studied SHE conductivity.

  8. On-Chip Microwave Quantum Hall Circulator

    Science.gov (United States)

    Mahoney, A. C.; Colless, J. I.; Pauka, S. J.; Hornibrook, J. M.; Watson, J. D.; Gardner, G. C.; Manfra, M. J.; Doherty, A. C.; Reilly, D. J.

    2017-01-01

    Circulators are nonreciprocal circuit elements that are integral to technologies including radar systems, microwave communication transceivers, and the readout of quantum information devices. Their nonreciprocity arises from the interference of microwaves over the centimeter scale of the signal wavelength, in the presence of bulky magnetic media that breaks time-reversal symmetry. Here, we realize a completely passive on-chip microwave circulator with size 1 /1000 th the wavelength by exploiting the chiral, "slow-light" response of a two-dimensional electron gas in the quantum Hall regime. For an integrated GaAs device with 330 μ m diameter and about 1-GHz center frequency, a nonreciprocity of 25 dB is observed over a 50-MHz bandwidth. Furthermore, the nonreciprocity can be dynamically tuned by varying the voltage at the port, an aspect that may enable reconfigurable passive routing of microwave signals on chip.

  9. Photonic spin Hall effect in topological insulators

    CERN Document Server

    Zhou, Xinxing; Ling, Xiaohui; Chen, Shizhen; Luo, Hailu; Wen, Shuangchun

    2013-01-01

    In this paper we theoretically investigate the photonic spin Hall effect (SHE) of a Gaussian beam reflected from the interface between air and topological insulators (TIs). The photonic SHE is attributed to spin-orbit coupling and manifests itself as in-plane and transverse spin-dependent splitting. We reveal that the spin-orbit coupling effect in TIs can be routed by adjusting the axion angle variations. Unlike the transverse spin-dependent splitting, we find that the in-plane one is sensitive to the axion angle. It is shown that the polarization structure in magneto-optical Kerr effect is significantly altered due to the spin-dependent splitting in photonic SHE. We theoretically propose a weak measurement method to determine the strength of axion coupling by probing the in-plane splitting of photonic SHE.

  10. Hydrodynamic Electron Flow and Hall Viscosity

    Science.gov (United States)

    Scaffidi, Thomas; Nandi, Nabhanila; Schmidt, Burkhard; Mackenzie, Andrew P.; Moore, Joel E.

    2017-06-01

    In metallic samples of small enough size and sufficiently strong momentum-conserving scattering, the viscosity of the electron gas can become the dominant process governing transport. In this regime, momentum is a long-lived quantity whose evolution is described by an emergent hydrodynamical theory. Furthermore, breaking time-reversal symmetry leads to the appearance of an odd component to the viscosity called the Hall viscosity, which has attracted considerable attention recently due to its quantized nature in gapped systems but still eludes experimental confirmation. Based on microscopic calculations, we discuss how to measure the effects of both the even and odd components of the viscosity using hydrodynamic electronic transport in mesoscopic samples under applied magnetic fields.

  11. Geometric Defects in Quantum Hall States

    CERN Document Server

    Gromov, Andrey

    2016-01-01

    We describe a geometric (or gravitational) analogue of the Laughlin quasiholes in the fractional quantum Hall states. Analogously to the quasiholes these defects can be constructed by an insertion of an appropriate vertex operator into the conformal block representation of a trial wavefunction, however, unlike the quasiholes these defects are extrinsic and do not correspond to true excitations of the quantum fluid. We construct a wavefunction in the presence of such defects and explain how to assign an electric charge and a spin to each defect, and calculate the adiabatic, non-abelian statistics of the defects. The defects turn out to be equivalent to the genons in that their adiabatic exchange statistics can be described in terms of representations of the mapping class group of an appropriate higher genus Riemann surface. We present a general construction that, in principle, allows to calculate the statistics of $\\mathbb Z_n$ genons for any "parent" topological phase. We illustrate the construction on the ex...

  12. Concept of Operating Indoor Skiing Halls with

    DEFF Research Database (Denmark)

    Paul, Joachim

    2003-01-01

    Indoor skiing halls are conventionally operated at low temperatures and with either crushed ice as snow substitute or snow made from freezing water in cold air. Both systems have a high energy demand for air cooling, floor freezing and consequently snow harvest. At the same time the snow at the top...... floor cooling/freezing and insulation become obsolete, significant savings in piping and building costs can be achieved. Due to the much higher evaporating temperature for the refrigeration system, the energy demand is kept low. Since the same equipment is used for both snowmaking and air cooling......, the running time of the equipment is high, resulting in a better economy. Using Binary Snow, with its unique qualities such as fluffy, crisp, white and ¿ since made daily ¿ "fresh and hygienic", offers great advantages in operating costs, investment costs and quality....

  13. Magnetic circuit for hall effect plasma accelerator

    Science.gov (United States)

    Manzella, David H. (Inventor); Jacobson, David T. (Inventor); Jankovsky, Robert S. (Inventor); Hofer, Richard (Inventor); Peterson, Peter (Inventor)

    2009-01-01

    A Hall effect plasma accelerator includes inner and outer electromagnets, circumferentially surrounding the inner electromagnet along a thruster centerline axis and separated therefrom, inner and outer magnetic conductors, in physical connection with their respective inner and outer electromagnets, with the inner magnetic conductor having a mostly circular shape and the outer magnetic conductor having a mostly annular shape, a discharge chamber, located between the inner and outer magnetic conductors, a magnetically conducting back plate, in magnetic contact with the inner and outer magnetic conductors, and a combined anode electrode/gaseous propellant distributor, located at a bottom portion of the discharge chamber. The inner and outer electromagnets, the inner and outer magnetic conductors and the magnetically conducting back plate form a magnetic circuit that produces a magnetic field that is largely axial and radially symmetric with respect to the thruster centerline.

  14. Hall MHD Equilibrium of Accelerated Compact Toroids

    Science.gov (United States)

    Howard, S. J.; Hwang, D. Q.; Horton, R. D.; Evans, R. W.; Brockington, S. J.

    2007-11-01

    We examine the structure and dynamics of the compact toroid's magnetic field. The compact toroid is dramatically accelerated by a large rail-gun Lorentz force density equal to j xB. We use magnetic data from the Compact Toroid Injection Experiment to answer the question of exactly where in the system j xB has nonzero values, and to what extent we can apply the standard model of force-free equilibrium. In particular we present a method of analysis of the magnetic field probe signals that allows direct comparison to the predictions of the Woltjer-Taylor force-free model and Turner's generalization of magnetic relaxation in the presence of a non-zero Hall term and fluid vorticity.

  15. Mesoscopic spin Hall effect in semiconductor nanostructures

    Science.gov (United States)

    Zarbo, Liviu

    The spin Hall effect (SHE) is a name given to a collection of diverse phenomena which share two principal features: (i) longitudinal electric current flowing through a paramagnetic semiconductor or metallic sample leads to transverse spin current and spin accumulation of opposite sign at opposing lateral edges; (ii) SHE does not require externally applied magnetic field or magnetic ordering in the equilibrium state of the sample, instead it relies on the presence of spin-orbit (SO) couplings within the sample. This thesis elaborates on a new type of phenomenon within the SHE family, predicted in our recent studies [Phys. Rev. B 72, 075361 (2005); Phys. Rev. Lett. 95, 046601 (2005); Phys. Rev. B 72, 075335 (2005); Phys. Rev. B 73 , 075303 (2006); and Europhys. Lett. 77, 47004 (2007)], where pure spin current flows through the transverse electrodes attached to a clean finitesize two-dimensional electron gas (2DEG) due to unpolarized charge current injected through its longitudinal leads. If transverse leads are removed, the effect manifests as nonequilibrium spin Hall accumulation at the lateral edges of 2DEG wires. The SO coupling driving this SHE effect is of the Rashba type, which arises due to structural inversion asymmetry of semiconductor heterostructure hosting the 2DEG. We term the effect "mesoscopic" because the spin Hall currents and accumulations reach optimal value in samples of the size of the spin precession length---the distance over which the spin of an electron precesses by an angle pi. In strongly SO-coupled structures this scale is of the order of ˜100 nm, and, therefore, mesoscopic in the sense of being much larger than the characteristic microscopic scales (such as the Fermi wavelength, screening length, or the mean free path in disordered systems), but still much smaller than the macroscopic ones. Although the first theoretical proposal for SHE, driven by asymmetry in SO-dependent scattering of spin-up and spin-down electrons off impurities

  16. Concept of Operating Indoor Skiing Halls with

    DEFF Research Database (Denmark)

    Paul, Joachim

    2003-01-01

    Indoor skiing halls are conventionally operated at low temperatures and with either crushed ice as snow substitute or snow made from freezing water in cold air. Both systems have a high energy demand for air cooling, floor freezing and consequently snow harvest. At the same time the snow at the top...... floor cooling/freezing and insulation become obsolete, significant savings in piping and building costs can be achieved. Due to the much higher evaporating temperature for the refrigeration system, the energy demand is kept low. Since the same equipment is used for both snowmaking and air cooling......, the running time of the equipment is high, resulting in a better economy. Using Binary Snow, with its unique qualities such as fluffy, crisp, white and ¿ since made daily ¿ "fresh and hygienic", offers great advantages in operating costs, investment costs and quality....

  17. The quantum Hall effect and its contexts

    OpenAIRE

    Rodríguez,Víctor

    2017-01-01

    En este artículo, se atienden ciertas facetas conceptuales y experimentales del efecto Hall cuántico. Se argumenta que el mismo ofrece variados matices para la reflexión filosófica, desde la generación de entidades teóricas hasta la epistemología de la experimentación. La exposición pretende mantener cierta sensibilidad por la dinámica histórica en torno del tema, como así también por las implicaciones metrológicas de ámbitos cuánticos específicos. Dada la enorme producción científica sobre e...

  18. Trombosis de senos durales: casuística del Hospital Dr. Rafael Angel Calderón Guardia, período 1996-1999

    Directory of Open Access Journals (Sweden)

    Kwok Ho Sánchez-Suen

    2001-10-01

    Full Text Available Justificación: La oclusión trombótica de las venas cerebrales o senos durales es una causa menos frecuente de enfermedad cerebrovascular que la trombosis arterial. Sin embargo; los estudios epidemiológicos indican que esta entidad no es tan inusual como o ser pensaba previamente. Hasta donde sabemos, no hay ningún estudio publicando al respecto en la literatura nacional, siendo precisamente el motivo del presente trabajo. Objetivos: Identificar las características demográficas, clínicas y diagnósticas de los pacientes que sufrieron una trombosis de senos venosos durales. Describir los métodos terapéuticos empleados y la evolución que tuvieron estos pacientes. Materiales y métodos: Se revisaron los expedientes clínicos de 11 casos diagnosticados de trombosis de senos durales en el Hospital Dr. Rafael Ángel Calderón Guardia, en el período comprendido entre enero de 1996 a enero de 1999. Se analizaron los posibles factores de riego, formas de presentación clínica, estudios de radio imagen y tratamiento empleado. Resultados: El promedio de edad fue de 32,6 años. Un 18,2% fueron varones, mientras que el 81,8% correspondió a mujeres. Las manifestaciones más frecuentes fueron: cefalea (100%, vómito (91%, déficit motor 882%, alteración del sensorio (73%, papiledema (54,5%, crisis convulsiva (54,5% y datos de irritación meníngea (36,4%: el signo del delta vacío se documentó en 27,3% de los estudios tomográficos. El seno sagital superior fue el más frecuentemente afectado (91%. Se anticoaguló con heparina intravenosa al 54, 5% de los casos. Conclusiones: Aunque somos conscientes de las limitaciones de nuestra serie, nuestra intención ha sido llamar la atención sobre una patología vascular cerebral, que aunque no es tan frecuente como su contraparte arterial, debe tenerse en consideración por sus potenciales efectos sobre la salud del paciente. El conocimiento adecuado de esta condición es importante, debido a que a

  19. Aplicación del modelo de psicoterapia breve intensiva de Leopold Bellak con mujeres en situación de violencia intrafamiliar que acuden al Centro de Equidad y Justicia de Calderón entre mayo y agosto de 2015

    OpenAIRE

    Fuertes Lagos, Alexandra Elizabeth

    2016-01-01

    Women in situations of domestic violence are the segment of the population widely demanding psychological care at the Centro de Equidad y Justicia de Calderón. To respond to this requirement, the application of the Intensive Brief Psychotherapy by Leopold Bellak is proposed. This model consists of 5 therapeutic sessions, plus a follow-up appointment, in which an entire understanding of the person is sought; main symptoms are identified and progressively treated in a positi...

  20. Stacking order dependence of inverse spin Hall effect and anomalous Hall effect in spin pumping experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Il; Seo, Min-Su; Park, Seung-Young, E-mail: parksy@kbsi.re.kr [Division of Materials Science, Korea Basic Science Institute, Daejeon 305-806 (Korea, Republic of); Kim, Dong-Jun; Park, Byong-Guk [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2015-05-07

    The dependence of the measured DC voltage on the non-magnetic material (NM) in NM/CoFeB and CoFeB/NM bilayers is studied under ferromagnetic resonance conditions in a TE{sub 011} resonant cavity. The directional change of the inverse spin Hall effect (ISHE) voltage V{sub ISHE} for the stacking order of the bilayer can separate the pure V{sub ISHE} and the anomalous Hall effect (AHE) voltage V{sub AHE} utilizing the method of addition and subtraction. The Ta and Ti NMs show a broad deviation of the spin Hall angle θ{sub ISH}, which originates from the AHE in accordance with the high resistivity of NMs. However, the Pt and Pd NMs show that the kinds of NMs with low resistivity are consistent with the previously reported θ{sub ISH} values. Therefore, the characteristics that NM should simultaneously satisfy to obtain a reasonable V{sub ISHE} value in bilayer systems are large θ{sub ISH} and low resistivity.

  1. Residencia hall del Obispado, en Gescher, Alemania

    Directory of Open Access Journals (Sweden)

    Deilmann, Harald

    1969-02-01

    Full Text Available This Hall has four lecture rooms, each with a capacity for twenty students. They all face north, have lateral and cenithal illumination and cross ventilation. The workshop training halls face south, and there is a gymnasium. Each classroom is also connected with a protected open air space, so that in suitable weather, teaching can be practised out of doors. As the school is devoted to mentally retarded boys and youths, over 2 m2 of floor area has been allowed for each student in the classrooms, since it was estimated that many students would be of the nervous type and would need more room to work freely. Most of the construction is made with unfaced brick and concrete, which are long lasting materials, requiring little maintenance.Comprende cuatro clases propiamente dichas, con una capacidad total de 80 alumnos, a razón de 20 por cada clase, y orientadas al norte, con iluminación cenital y lateral y ventilación cruzada. Los locales donde se imparten las enseñanzas de taller tienen orientación sur. Se ha previsto, además, un gimnasio. Cada clase dispone de un recinto protegido para que, cuando las condiciones atmosféricas lo permitan, se pueda desarrollar en él la enseñanza al aire libre. Como la escuela está destinada a niños y adolescentes retrasados mentales, se partió de un espacio superior a los 2 m2 por alumno, pensando en que parte de ellos iban a ser niños nerviosos y, como consecuencia, la necesidad que tendrían de amplitud suficiente para desenvolverse adecuadamente. La construcción se ha desarrollado, en general, a base de fábrica de ladrillo a cara vista y hormigón visto, materiales de gran duración y prácticamente exentos de entretenimiento.

  2. Hall transport of divalent metal ion modified DNA lattices

    Energy Technology Data Exchange (ETDEWEB)

    Dugasani, Sreekantha Reddy; Lee, Keun Woo; Yoo, Sanghyun; Gnapareddy, Bramaramba; Bashar, Saima; Park, Sung Ha, E-mail: sunghapark@skku.edu [Department of Physics and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Si Joon; Jung, Joohye; Jung, Tae Soo; Kim, Hyun Jae, E-mail: hjk3@yonsei.ac.kr [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2015-06-29

    We investigate the Hall transport characteristics of double-crossover divalent metal ion (Cu{sup 2+}, Ni{sup 2+}, Zn{sup 2+}, and Co{sup 2+})-modified DNA (M-DNA) lattices grown on silica via substrate-assisted growth. The electronic characteristics of the M-DNA lattices are investigated by varying the concentration of the metal ions and then conducting Hall measurements, including resistivity, Hall mobility, carrier concentration, and magneto resistance. The tendency of the resistivity and Hall mobility was to initially decrease as the ion concentration increased, until reaching the saturation concentration (C{sub s}) of each metal ion, and then to increase as the ion concentration increased further. On the other hand, the carrier concentration revealed the opposite tendency as the resistivity and Hall mobility. The specific binding (≤C{sub s}) and the nonspecific aggregates (>C{sub s}) of the ions into the DNA lattices were significantly affected by the Hall characteristics. The numerical ranges of the Hall parameters revealed that the M-DNA lattices with metal ions had semiconductor-like characteristics. Consequently, the distinct characteristics of the electrical transport through M-DNA lattices will provide useful information on the practical use of such structures in physical devices and chemical sensors.

  3. Joule-Heated Molten Regolith Electrolysis Reactor Concepts for Oxygen and Metals Production on the Moon and Mars

    Science.gov (United States)

    Sibille, Laurent; Dominques, Jesus A.

    2012-01-01

    The maturation of Molten Regolith Electrolysis (MRE) as a viable technology for oxygen and metals production on explored planets relies on the realization of the self-heating mode for the reactor. Joule heat generated during regolith electrolysis creates thermal energy that should be able to maintain the molten phase (similar to electrolytic Hall-Heroult process for aluminum production). Self-heating via Joule heating offers many advantages: (1) The regolith itself is the crucible material, it protects the vessel walls (2) Simplifies the engineering of the reactor (3) Reduces power consumption (no external heating) (4) Extends the longevity of the reactor. Predictive modeling is a tool chosen to perform dimensional analysis of a self-heating reactor: (1) Multiphysics modeling (COMSOL) was selected for Joule heat generation and heat transfer (2) Objective is to identify critical dimensions for first reactor prototype.

  4. Slurry reactor design studies

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. (Bechtel Group, Inc., San Francisco, CA (USA)); Akgerman, A. (Texas A and M Univ., College Station, TX (USA)); Smith, J.M. (California Univ., Davis, CA (USA))

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  5. Current and future capabilities of the neutron reflectometer MIRROR at Oak Ridge National Laboratory's High Flux Isotope Reactor

    Science.gov (United States)

    Hamilton, W. A.; Smith, G. S.; Taylor, G. B.; Larkins, B. M.; Porcar, L.

    2006-11-01

    The peripatetic ORNL HFIR Center for Neutron Scattering reflectometer instrument MIRROR has recently been re-installed in an interim beam line position in the reactor beam room. In 2006 an upgraded version of the instrument will move to a high intensity guide hall position fed by the new HFIR cold source. In this short note, we present some aspects of current instrument operation-particularly with respect to data reduction from the instrument's linear reflection plane detector-with examples of ongoing research and analysis, and a brief outline of the expected capabilities of the fully upgraded guide hall instrument.

  6. Effective Field Theory of Fractional Quantized Hall Nematics

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, Michael; /MIT, LNS; Nayak, Chetan; /Station Q, UCSB; Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC

    2012-06-06

    We present a Landau-Ginzburg theory for a fractional quantized Hall nematic state and the transition to it from an isotropic fractional quantum Hall state. This justifies Lifshitz-Chern-Simons theory - which is shown to be its dual - on a more microscopic basis and enables us to compute a ground state wave function in the symmetry-broken phase. In such a state of matter, the Hall resistance remains quantized while the longitudinal DC resistivity due to thermally-excited quasiparticles is anisotropic. We interpret recent experiments at Landau level filling factor {nu} = 7/3 in terms of our theory.

  7. Audience noise in concert halls during musical performances

    DEFF Research Database (Denmark)

    Marie, Pierre; Jeong, Cheol-Ho; Brunskog, Jonas

    2012-01-01

    Noise generated by the audience during musical performances is audible and sometimes disturbing. In this study, an attempt to estimate such audience noise was carried out. From the recordings of performances in five performance spaces (four concert halls and one opera house), probability density...... prediction models were made using the four orchestra concert halls, revealing that the audience noise level is significantly correlated with the technical background noise level. It is therefore concluded that a relaxation of the current background noise recommendations for concert halls is not recommended....

  8. Audience noise in concert halls during musical performances

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Marie, Pierre; Brunskog, Jonas

    2012-01-01

    Noise generated by the audience during musical performances is audible and sometimes disturbing. In this study, an attempt to estimate such audience noise was carried out. From the recordings of performances in five performance spaces (four concert halls and one opera house), probability density...... prediction models were made using the four orchestra concert halls, revealing that the audience noise level is significantly correlated with the technical background noise level. It is therefore concluded that a relaxation of the current background noise recommendations for concert halls is not recommended...

  9. Anomalous Hall effect in Fe/Gd bilayers

    KAUST Repository

    Xu, W. J.

    2010-04-01

    Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd simultaneously. The temperature and field dependences of longitudinal resistivity, Hall resistivity and magnetization in these films have also been carefully measured. The analysis of these data reveals that these intriguing features are due to the opposite signs of Hall resistivity/or spin polarization and different Curie temperatures of Fe and Gd single-layer films. Copyright (C) EPLA, 2010

  10. Modelling of micro-Hall sensors for magnetization imaging

    Science.gov (United States)

    Manzin, A.; Nabaei, V.

    2014-05-01

    This paper presents a numerical model for the study of micro-Hall magnetometry applications, aiming at evaluating the sensitivity of semiconductor miniaturized devices to the stray field of permalloy nanostructures with ring and disk geometry. The procedure couples a micromagnetic code, for the calculation of the stray field generated by the nanomagnet, to a 2D classical transport model for the determination of the electric potential distribution inside the Hall plate. The model is applied to study the sensitivity of a micro-Hall device in the detection of magnetization switching processes characterized by vortex state, focusing on the influence of magnetic nanostructure position.

  11. TCC2, the target hall of the SPS North Area

    CERN Multimedia

    1978-01-01

    In the foreground can be seen the three proton beam branches leading to the targets enclosed in an assembly of iron blocks with the positioning mechanism on top. In the background, the six secondary beams lead off towards the experimental areas, H2/P2, H4/E4/P4 (from T2 via TT81) and H6, H8 (from T4 via TT82) towards the hall EHN1, M2 from T6 via TT83 towards the hall EHN2. The development proton beam line P0 leads off from T4 via TT83 towards TCC8 and hall ECN3 (NAHIF).

  12. Composed planar Hall effect sensors with dual-mode operation

    OpenAIRE

    Vladislav Mor; Debangsu Roy; Moty Schultz; Lior Klein

    2016-01-01

    We present a composed planar Hall effect sensor with two modes of operation: (a) an ON mode where the composed sensor responds to magnetic field excitations similarly to the response of a regular planar Hall effect sensor, and (b) an OFF mode where the response is negligible. The composed planar Hall effect sensor switches from the OFF mode to the ON mode when it is exposed to a magnetic field which exceeds a certain threshold determined by the sensor design. The features of this sensor make ...

  13. Hall conductance and topological invariant for open systems.

    Science.gov (United States)

    Shen, H Z; Wang, W; Yi, X X

    2014-09-24

    The Hall conductivity given by the Kubo formula is a linear response of quantum transverse transport to a weak electric field. It has been intensively studied for quantum systems without decoherence, but it is barely explored for systems subject to decoherence. In this paper, we develop a formulism to deal with this issue for topological insulators. The Hall conductance of a topological insulator coupled to an environment is derived, the derivation is based on a linear response theory developed for open systems in this paper. As an application, the Hall conductance of a two-band topological insulator and a two-dimensional lattice is presented and discussed.

  14. Hall effect in CNT doped YBCO high temperature superconductor

    Directory of Open Access Journals (Sweden)

    S Dadras

    2010-09-01

    Full Text Available In order to study Hall effect in pure and CNT doped YBCO polycrystalline samples, we have measured longitudinal and transverse voltages at the different magnetic field (0-9T in the vortex state. We found a sign reversal for pure sample near 3T and double sign reversal of the Hall coefficient for CNT doped sample near 3 and 5T. It can be deduced that CNT doping caused strong flux pinning and Hall double sign reversal in this compound.

  15. Quantized Anomalous Hall Effect in Magnetic Topological Insulators

    Institute of Scientific and Technical Information of China (English)

    YU Rui

    2011-01-01

    The Hall effect, the anomalous Hall effect (AHE) and the spin Hall effect are thndamental transport processes in solids arising from the Lorentz force and the spin-orbit coupling respectively. The AHE, in which a voltage transverse to the electric current appears even in the absence of an external magnetic field, was first detected in ferromagnetic (FM) metals in 1881 and later found to arise from the spin-orbit coupling (SOC) between the current and magnetic moments.

  16. Kelvin-Helmholtz versus Hall magnetoshear instability in astrophysical flows.

    Science.gov (United States)

    Gómez, Daniel O; Bejarano, Cecilia; Mininni, Pablo D

    2014-05-01

    We study the stability of shear flows in a fully ionized plasma. Kelvin-Helmholtz is a well-known macroscopic and ideal shear-driven instability. In sufficiently low-density plasmas, also the microscopic Hall magnetoshear instability can take place. We performed three-dimensional simulations of the Hall-magnetohydrodynamic equations where these two instabilities are present, and carried out a comparative study. We find that when the shear flow is so intense that its vorticity surpasses the ion-cyclotron frequency of the plasma, the Hall magnetoshear instability is not only non-negligible, but it actually displays growth rates larger than those of the Kelvin-Helmholtz instability.

  17. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  18. Gas cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1972-06-01

    Although most of the development work on fast breeder reactors has been devoted to the use of liquid metal cooling, interest has been expressed for a number of years in alternative breeder concepts using other coolants. One of a number of concepts in which interest has been retained is the Gas-Cooled Fast Reactor (GCFR). As presently envisioned, it would operate on the uranium-plutonium mixed oxide fuel cycle, similar to that used in the Liquid Metal Fast Breeder Reactor (LMFBR), and would use helium gas as the coolant.

  19. Microfluidic electrochemical reactors

    Science.gov (United States)

    Nuzzo, Ralph G [Champaign, IL; Mitrovski, Svetlana M [Urbana, IL

    2011-03-22

    A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

  20. From University Heights to Cooperstown: Halls of Fame and American Memory

    Science.gov (United States)

    Friss, Evan J.

    2005-01-01

    This article examines the development and function of American halls of fame as cultural memory institutions. By comparing the Hall of Fame for Great Americans with the National Baseball Hall of Fame, the author posits that halls of fame illuminate the ways in which cultural memory institutions can, through an archival process, preserve, instill,…

  1. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed.

  2. New reactor type proposed

    CERN Multimedia

    2003-01-01

    "Russian scientists at the Research Institute of Nuclear Power Engineering in Moscow are hoping to develop a new reactor that will use lead and bismuth as fuel instead of uranium and plutonium" (1/2 page).

  3. Reactor Neutrino Spectra

    CERN Document Server

    Hayes, A C

    2016-01-01

    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these and their associated uncertainties are crucial for neutrino oscillation studies. The spectra used to-date have been determined by either conversion of measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that makeup the spectra using modern databases as input. The uncertainties in the subdominant corrections to beta-decay plague both methods, and we provide estimates of these uncertainties. Improving on current knowledge of the antineutrino spectra from reactors will require new experiments. Such experiments would also address the so-called reactor neutrino anomaly and the possible origin of the shoulder observed in the antineutrino spectra measured in recent high-statistics reactor neutrino experiments.

  4. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2001-04-01

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given.

  5. CMOS Compatible 3-Axis Magnetic Field Sensor using Hall Effect Sensing

    Science.gov (United States)

    Locke, Joshua R.

    The purpose of this study is to design, fabricate and test a CMOS compatible 3-axis Hall effect sensor capable of detecting the earth's magnetic field, with strength's of ˜50 muT. Preliminary testing of N-well Van Der Pauw structures using strong neodymium magnets showed proof of concept for hall voltage sensing, however, poor geometry of the structures led to a high offset voltage. A 1-axis Hall effect sensor was designed, fabricated and tested with a sensitivity of 1.12x10-3 mV/Gauss using the RIT metal gate PMOS process. Poor geometry and insufficient design produced an offset voltage of 0.1238 volts in the 1-axis design; prevented sensing of the earth's magnetic field. The new design features improved geometry for sensing application, improved sensitivity and use the RIT sub-CMOS process. The completed 2-axis device showed an average sensitivity to large magnetic fields of 0.0258 muV/Gauss at 10 mA supply current.

  6. Summer residence hall renovations focus on student comfort, environmental sustainability

    OpenAIRE

    DeLauder, Rachel

    2009-01-01

    With the majority of students home for the summer, Virginia Tech Housing Services has undertaken a variety of improvements and renovations in its residence halls aimed at increasing comfort and safety for students, while decreasing overall environmental impact.

  7. Segal-Bargmann-Hall Transform and Geometric Quantization

    Institute of Scientific and Technical Information of China (English)

    刘卫平; 王正栋; 胡大鹏

    2003-01-01

    @@ Using geometric methods, Hall has proved that the Segal-Bargmann transform for a con-nected Lie group K of compact type is an isometric isomorphism [H1] and is unique when Kis simply connected [H7].

  8. A High Performance Cathode Heater for Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High current hollow cathodes are the baseline electron source for next generation high power Hall thrusters. Currently for electron sources providing current levels...

  9. Wellness: A Developmental Programming Model for Residence Halls.

    Science.gov (United States)

    Warner, Mark J.

    1985-01-01

    Demonstrates how a Wellness model can be an effective vehicle for promoting developmental programs in residence halls. The Wellness model is examined in terms of marketing, student development theory, and balanced programming. (BL)

  10. High Throughput Hall Thruster for Small Spacecraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek Co. Inc. proposes to develop a high throughput, nominal 100 W Hall Effect Thruster (HET). This HET will be sized for small spacecraft (< 180 kg), including...

  11. Magnesium Hall Thruster for Solar System Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation being developed in this program is a Mg Hall Effect Thruster system that would open the door for In-Situ Resource Utilization based solar system...

  12. High Input Voltage Hall Thruster Discharge Converter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall scope of this Phase I/II effort is the development of a high efficiency 15kW (nominal) Hall thruster discharge converter. In Phase I, Busek Co. Inc. will...

  13. High Throughput Hall Thruster for Small Spacecraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek is developing a high throughput nominal 100-W Hall Effect Thruster. This device is well sized for spacecraft ranging in size from several tens of kilograms to...

  14. The Dream Comes True in the Golden Hall

    Institute of Scientific and Technical Information of China (English)

    JianZhong; ChenJianguo

    2004-01-01

    Nanjing Traditional Music Ensemble has long dreamed of performing in Vienna's Golden Hall.Now the dream has come true.the whole troupe felt so exciting that they did not even sleep well during the flight.

  15. Mini array of quantum Hall devices based on epitaxial graphene

    Science.gov (United States)

    Novikov, S.; Lebedeva, N.; Hämäläinen, J.; Iisakka, I.; Immonen, P.; Manninen, A. J.; Satrapinski, A.

    2016-05-01

    Series connection of four quantum Hall effect (QHE) devices based on epitaxial graphene films was studied for realization of a quantum resistance standard with an up-scaled value. The tested devices showed quantum Hall plateaux RH,2 at a filling factor v = 2 starting from a relatively low magnetic field (between 4 T and 5 T) when the temperature was 1.5 K. The precision measurements of quantized Hall resistance of four QHE devices connected by triple series connections and external bonding wires were done at B = 7 T and T = 1.5 K using a commercial precision resistance bridge with 50 μA current through the QHE device. The results showed that the deviation of the quantized Hall resistance of the series connection of four graphene-based QHE devices from the expected value of 4×RH,2 = 2 h/e2 was smaller than the relative standard uncertainty of the measurement (resistance bridge.

  16. Magnesium Hall Thruster for Solar System Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek proposes to prove the feasibility of a Mg Hall effect thruster system that would open the door for In-Situ Resource Utilization (ISRU) based solar system...

  17. Pragmatic data fusion uncertainty concerns: Tribute to Dave L. Hall

    CSIR Research Space (South Africa)

    Blasch, E

    2016-07-01

    Full Text Available to knowledge acquisition and delivery. A summary of the uncertainty issues from Dave Hall, originating with the Joint Directors of the Laboratories (JDL) model, include these attributes across the JDL Levels which are: data (variance), object assessment...

  18. Hall Determination of Atomic Radii of Alkali Metals

    Science.gov (United States)

    Houari, Ahmed

    2008-01-01

    I will propose here an alternative method for determining atomic radii of alkali metals based on the Hall measurements of their free electron densities and the knowledge of their crystal structure. (Contains 2 figures.)

  19. Valleytronics. The valley Hall effect in MoS₂ transistors.

    Science.gov (United States)

    Mak, K F; McGill, K L; Park, J; McEuen, P L

    2014-06-27

    Electrons in two-dimensional crystals with a honeycomb lattice structure possess a valley degree of freedom (DOF) in addition to charge and spin. These systems are predicted to exhibit an anomalous Hall effect whose sign depends on the valley index. Here, we report the observation of this so-called valley Hall effect (VHE). Monolayer MoS2 transistors are illuminated with circularly polarized light, which preferentially excites electrons into a specific valley, causing a finite anomalous Hall voltage whose sign is controlled by the helicity of the light. No anomalous Hall effect is observed in bilayer devices, which have crystal inversion symmetry. Our observation of the VHE opens up new possibilities for using the valley DOF as an information carrier in next-generation electronics and optoelectronics.

  20. Fractional quantum Hall effect in the absence of Landau levels.

    Science.gov (United States)

    Sheng, D N; Gu, Zheng-Cheng; Sun, Kai; Sheng, L

    2011-07-12

    It is well known that the topological phenomena with fractional excitations, the fractional quantum Hall effect, will emerge when electrons move in Landau levels. Here we show the theoretical discovery of the fractional quantum Hall effect in the absence of Landau levels in an interacting fermion model. The non-interacting part of our Hamiltonian is the recently proposed topologically non-trivial flat-band model on a checkerboard lattice. In the presence of nearest-neighbouring repulsion, we find that at 1/3 filling, the Fermi-liquid state is unstable towards the fractional quantum Hall effect. At 1/5 filling, however, a next-nearest-neighbouring repulsion is needed for the occurrence of the 1/5 fractional quantum Hall effect when nearest-neighbouring repulsion is not too strong. We demonstrate the characteristic features of these novel states and determine the corresponding phase diagram.

  1. Hall Viscosity I: Linear Response Theory for Viscosity

    Science.gov (United States)

    Bradlyn, Barry; Goldstein, Moshe; Read, Nicholas

    2012-02-01

    In two dimensional systems with broken time-reversal symmetry, there can exist a non-dissipative viscosity coefficient [1,2,3]. This Hall viscosity is similar in nature to the non-dissipative Hall conductivity. In order to investigate this phenomenon further, we develop a linear response formalism for viscosity. We derive a Kubo formula for the frequency dependent viscosity tensor in the long wavelength limit. We compute the viscosity tensor for the free electron gas, integer quantum Hall systems, and two-dimensional paired superfluids. In the zero frequency limit, we show how the known results [3,4] for the Hall viscosity are recovered.[4pt] [1] J. Avron, R. Seiler, and P. Zograf, Phys. Rev. Lett. 75, 697 (1995).[0pt] [2] P. Levay, J. Math. Phys. 36, 2792 (1995).[0pt] [3] N. Read, Phys. Rev. B 79, 045308 (2009).[0pt] [4] N. Read and E. Rezayi, Phys. Rev. B 84, 085316 (2011).

  2. Global regularity for generalized Hall magneto-hydrodynamics systems

    Directory of Open Access Journals (Sweden)

    Renhui Wan

    2015-06-01

    Full Text Available In this article, we consider the tridimensional generalized Hall magneto-hydrodynamics (Hall-MHD system, with $(-\\Delta^\\alpha u$ and $(-\\Delta^\\beta b$. For $\\alpha\\ge 5/4$, $\\beta\\ge 7/4$, we obtain the global regularity of classical solutions. For $0<\\alpha<5/4$ and $1/2<\\beta<7/4$, with small data, the system also possesses global classical solutions. In addition, for the standard Hall-MHD system, $\\alpha=\\beta=1$, by adding a suitable condition, we give a positive answer to the open question in [3]. At last, we study the regularity criterions of generalized Hall-MHD system. In particular, we prove the regularity criterion in terms of horizontal gradient $\

  3. Future Reactor Experiments

    OpenAIRE

    He, Miao

    2013-01-01

    The measurement of the neutrino mixing angle $\\theta_{13}$ opens a gateway for the next generation experiments to measure the neutrino mass hierarchy and the leptonic CP-violating phase. Future reactor experiments will focus on mass hierarchy determination and the precision measurement of mixing parameters. Mass hierarchy can be determined from the disappearance of reactor electron antineutrinos based on the interference effect of two separated oscillation modes. Relative and absolute measure...

  4. Reactor Neutrino Experiments

    OpenAIRE

    Cao, Jun

    2007-01-01

    Precisely measuring $\\theta_{13}$ is one of the highest priority in neutrino oscillation study. Reactor experiments can cleanly determine $\\theta_{13}$. Past reactor neutrino experiments are reviewed and status of next precision $\\theta_{13}$ experiments are presented. Daya Bay is designed to measure $\\sin^22\\theta_{13}$ to better than 0.01 and Double Chooz and RENO are designed to measure it to 0.02-0.03. All are heading to full operation in 2010. Recent improvements in neutrino moment measu...

  5. Department of Reactor Technology

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included.......The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included....

  6. Helias reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Beidler, C.D. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Grieger, G. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Harmeyer, E. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kisslinger, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Karulin, N. [Nuclear Fusion Institute, Moscow (Russian Federation); Maurer, W. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany); Nuehrenberg, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Rau, F. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Sapper, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Wobig, H. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1995-10-01

    The present status of Helias reactor studies is characterised by the identification and investigation of specific issues which result from the particular properties of this type of stellarator. On the technical side these are issues related to the coil system, while physics studies have concentrated on confinement, alpha-particle behaviour and ignition conditions. The usual assumptions have been made in those fields which are common to all toroidal fusion reactors: blanket and shield, refuelling and exhaust, safety and economic aspects. For blanket and shield sufficient space has been provided, a detailed concept will be developed in future. To date more emphasis has been placed on scoping and parameter studies as opposed to fixing a specific set of parameters and providing a detailed point study. One result of the Helias reactor studies is that physical dimensions are on the same order as those of tokamak reactors. However, it should be noticed that this comparison is difficult in view of the large spectrum of tokamak reactors ranging from a small reactor like Aries, to a large device such as SEAFP. The notion that the large aspect ratio of 10 or more in Helias configurations also leads to large reactors is misleading, since the large major radius of 22 m is compensated by the average plasma radius of 1.8 m and the average coil radius of 5 m. The plasma volume of 1400 m{sup 3} is about the same as the ITER reactor and the magnetic energy of the coil system is about the same or even slightly smaller than envisaged in ITER. (orig.)

  7. INVAP's Research Reactor Designs

    OpenAIRE

    Eduardo Villarino; Alicia Doval

    2011-01-01

    INVAP, an Argentine company founded more than three decades ago, is today recognized as one of the leaders within the research reactor industry. INVAP has participated in several projects covering a wide range of facilities, designed in accordance with the requirements of our different clients. For complying with these requirements, INVAP developed special skills and capabilities to deal with different fuel assemblies, different core cooling systems, and different reactor layouts. This paper ...

  8. The reactor antineutrino anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Haser, Julia; Buck, Christian; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2016-07-01

    Major discoveries were made in the past few years in the field of neutrino flavour oscillation. Nuclear reactors produce a clean and intense flux of electron antineutrinos and are thus an essential neutrino source for the determination of oscillation parameters. Most currently the reactor antineutrino experiments Double Chooz, Daya Bay and RENO have accomplished to measure θ{sub 13}, the smallest of the three-flavour mixing angles. In the course of these experiments two anomalies emerged: (1) the reanalysis of the reactor predictions revealed a deficit in experimentally observed antineutrino flux, known as the ''reactor antineutrino anomaly''. (2) The high precision of the latest generation of neutrino experiments resolved a spectral shape distortion relative to the expected energy spectra. Both puzzles are yet to be solved and triggered new experimental as well as theoretical studies, with the search for light sterile neutrinos as most popular explanation for the flux anomaly. This talk outlines the two reactor antineutrino anomalies. Discussing possible explanations for their occurrence, recent and upcoming efforts to solve the reactor puzzles are highlighted.

  9. Moon base reactor system

    Science.gov (United States)

    Chavez, H.; Flores, J.; Nguyen, M.; Carsen, K.

    1989-01-01

    The objective of our reactor design is to supply a lunar-based research facility with 20 MW(e). The fundamental layout of this lunar-based system includes the reactor, power conversion devices, and a radiator. The additional aim of this reactor is a longevity of 12 to 15 years. The reactor is a liquid metal fast breeder that has a breeding ratio very close to 1.0. The geometry of the core is cylindrical. The metallic fuel rods are of beryllium oxide enriched with varying degrees of uranium, with a beryllium core reflector. The liquid metal coolant chosen was natural lithium. After the liquid metal coolant leaves the reactor, it goes directly into the power conversion devices. The power conversion devices are Stirling engines. The heated coolant acts as a hot reservoir to the device. It then enters the radiator to be cooled and reenters the Stirling engine acting as a cold reservoir. The engines' operating fluid is helium, a highly conductive gas. These Stirling engines are hermetically sealed. Although natural lithium produces a lower breeding ratio, it does have a larger temperature range than sodium. It is also corrosive to steel. This is why the container material must be carefully chosen. One option is to use an expensive alloy of cerbium and zirconium. The radiator must be made of a highly conductive material whose melting point temperature is not exceeded in the reactor and whose structural strength can withstand meteor showers.

  10. Phonon Hall Effect in Four-Terminal Junctions

    OpenAIRE

    Zhang, Lifa; Wang, Jian-Sheng; Li, Baowen

    2009-01-01

    Using an exact nonequilibrium Green's function formulism, the phonon Hall effect for paramagnetic dielectrics is studied in a four-terminal device setting. The temperature difference in the transverse direction of the heat current is calculated for two-dimensional models with the magnetic field perpendicular to the plane. We find a surprising result that the square lattice does not have the phonon Hall effect while a honeycomb lattice has. This can be explained by symmetry. The temperature di...

  11. Chern-Simons Dynamics and the Quantum Hall Effect

    CERN Document Server

    Balachandran, A P

    1991-01-01

    Theoretical developments during the past several years have shown that large scale properties of the Quantum Hall system can be successfully described by effective field theories which use the Chern-Simons interaction. In this article, we first recall certain salient features of the Quantum Hall Effect and their microscopic explanation. We then review one particular approach to their description based on the Chern-Simons Lagrangian and its variants.

  12. Spin and Isospin: Exotic Order in Quantum Hall Ferromagnets

    Science.gov (United States)

    Girvin, Steven M.

    Quantum mechanics is a strange business, and the quantum physics of strongly correlated many-electron systems can be stranger still. Good examples are the various quantum Hall effects. They are among the most remarkable many-body quantum phenomena discovered in the second half of the 20th century, comparable in intellectual import to superconductivity and superfluidity. The quantum Hall effects are an extremely rich set of phenomena with deep and truly fundamental theoretical implications...

  13. Hall viscosity and electromagnetic response of electrons in graphene

    Science.gov (United States)

    Sherafati, Mohammad; Principi, Alessandro; Vignale, Giovanni

    2016-09-01

    We derive an analytic expression for the geometric Hall viscosity of noninteracting electrons in a single graphene layer in the presence of a perpendicular magnetic field. We show that a recently derived formula in C. Hoyos and D. T. Son [Phys. Rev. Lett. 108, 066805 (2012), 10.1103/PhysRevLett.108.066805], which connects the coefficient of q2 in the wave-vector expansion of the Hall conductivity σx y(q ) of the two-dimensional electron gas (2DEG) to the Hall viscosity and the orbital diamagnetic susceptibility of that system, continues to hold for graphene, in spite of the lack of Galilean invariance, with a suitable definition of the effective mass. We also show that, for a sufficiently large number of occupied Landau levels in the positive-energy sector, the Hall conductivity of electrons in graphene reduces to that of a Galilean-invariant 2DEG with an effective mass given by ℏ kF/vF (cyclotron mass). Even in the most demanding case, i.e., when the chemical potential falls between the zeroth and the first Landau levels, the cyclotron mass formula gives results accurate to better than 1%. The connection between the Hall conductivity and the viscosity provides a possible avenue to measure the Hall viscosity in graphene.

  14. Tunnelling anomalous and planar Hall effects (Conference Presentation)

    Science.gov (United States)

    Matos-Abiague, Alex; Scharf, Benedikt; Han, Jong E.; Hankiewicz, Ewelina M.; Zutic, Igor

    2016-10-01

    We theoretically show how the interplay between spin-orbit coupling (SOC) and magnetism can result in a finite tunneling Hall conductance, transverse to the applied bias. For two-dimensional tunnel junctions with a ferromagnetic lead and magnetization perpendicular to the current flow, the detected anomalous Hall voltage can be used to extract information not only about the spin polarization but also about the strength of the interfacial SOC. In contrast, a tunneling current across a ferromagnetic barrier on the surface of a three-dimensional topological insulator (TI) can induce a planar Hall response even when the magnetization is oriented along the current flow[1]. The tunneling nature of the states contributing to the planar Hall conductance can be switched from the ordinary to the Klein regimes by the electrostatic control of the barrier strength. This allows for an enhancement of the transverse response and a giant Hall angle, with the tunneling planar Hall conductance exceeding the longitudinal component. Despite the simplicity of a single ferromagnetic region, the TI/ferromagnet system exhibits a variety of functionalities. In addition to a spin-valve operation for magnetic sensing and storing information, positive, negative, and negative differential conductances can be tuned by properly adjusting the barrier potential and/or varying the magnetization direction. Such different resistive behaviors in the same system are attractive for potential applications in reconfigurable spintronic devices. [1] B. Scharf, A. Matos-Abiague, J. E. Han, E. M. Hankiewicz, and I. Zutic, arXiv:1601.01009 (2016).

  15. The quantum Hall's effect:A quantum electrodynamic phenomenon

    Institute of Scientific and Technical Information of China (English)

    A.I. Arbab

    2012-01-01

    We have applied Maxwell's equations to study the physics of quantum Hall's effect.The electromagnetic properties of this system are obtained.The Hall's voltage,VH =2πh2ns/e rn,where ns is the electron number density,for a 2-dimensional system,and h =2πh is the Planck's constant,is found to coincide with the voltage drop across the quantum capacitor.Consideration of the cyclotronic motion of electrons is found to give rise to Hall's resistance.Ohmic resistances in the horizontal and vertical directions have been found to exist before equilibrium state is reached.At a fundamental level,the Hall's effect is found to be equivalent to a resonant LCR circuit with LH =2π m/e2ns and CH =me2/2πh2ns satisfying the resonance condition with resonant frequency equal to the inverse of the scattering (relaxation) time,Ts.The Hall's resistance is found to be RH =√LH/CH.The Hall's resistance may be connected with the impedance that the electron wave experiences when it propagates in the 2-dimeasional gas.

  16. Magnetometry of micro-magnets with electrostatically defined Hall bars

    Energy Technology Data Exchange (ETDEWEB)

    Lachance-Quirion, Dany; Camirand Lemyre, Julien; Bergeron, Laurent; Sarra-Bournet, Christian [Département de Physique, Université de Sherbrooke, J1K 2R1 Sherbrooke, Québec (Canada); Pioro-Ladrière, Michel, E-mail: michel.pioro-ladriere@usherbrooke.ca [Département de Physique, Université de Sherbrooke, J1K 2R1 Sherbrooke, Québec (Canada); CIFAR Program in Quantum Information Science, Canadian Institute for Advanced Research (CIFAR), M5G 1Z8 Toronto, Ontario (Canada)

    2015-11-30

    Micro-magnets are key components for quantum information processing with individual spins, enabling arbitrary rotations and addressability. In this work, characterization of sub-micrometer sized CoFe ferromagnets is performed with Hall bars electrostatically defined in a two-dimensional electron gas. Due to the ballistic nature of electron transport in the cross junction of the Hall bar, anomalies such as the quenched Hall effect appear near zero external magnetic field, thus hindering the sensitivity of the magnetometer to small magnetic fields. However, it is shown that the sensitivity of the diffusive limit can be almost completely restored at low temperatures using a large current density in the Hall bar of about 10 A/m. Overcoming the size limitation of conventional etched Hall bars with electrostatic gating enables the measurement of magnetization curves of 440 nm wide micro-magnets with a signal-to-noise ratio above 10{sup 3}. Furthermore, the inhomogeneity of the stray magnetic field created by the micro-magnets is directly measured using the gate-voltage-dependent width of the sensitive area of the Hall bar.

  17. Giant Hall Photoconductivity in Narrow-Gapped Dirac Materials.

    Science.gov (United States)

    Song, Justin C W; Kats, Mikhail A

    2016-12-14

    Carrier dynamics acquire a new character in the presence of Bloch-band Berry curvature, which naturally arises in gapped Dirac materials (GDMs). Here, we argue that photoresponse in GDMs with small band gaps is dramatically enhanced by Berry curvature. This manifests in a giant and saturable Hall photoconductivity when illuminated by circularly polarized light. Unlike Hall motion arising from a Lorentz force in a magnetic field, which impedes longitudinal carrier motion, Hall photoconductivity arising from Berry curvature can boost longitudinal carrier transport. In GDMs, this results in a helicity-dependent photoresponse in the Hall regime, where photoconductivity is dominated by its Hall component. We find that the induced Hall conductivity per incident irradiance is enhanced by up to 6 orders of magnitude when moving from the visible regime (with corresponding band gaps) to the far infrared. These results suggest that narrow-gap GDMs are an ideal test-bed for the unique physics that arise in the presence of Berry curvature and open a new avenue for infrared and terahertz optoelectronics.

  18. The spin Hall effect in a quantum gas.

    Science.gov (United States)

    Beeler, M C; Williams, R A; Jiménez-García, K; LeBlanc, L J; Perry, A R; Spielman, I B

    2013-06-13

    Electronic properties such as current flow are generally independent of the electron's spin angular momentum, an internal degree of freedom possessed by quantum particles. The spin Hall effect, first proposed 40 years ago, is an unusual class of phenomena in which flowing particles experience orthogonally directed, spin-dependent forces--analogous to the conventional Lorentz force that gives the Hall effect, but opposite in sign for two spin states. Spin Hall effects have been observed for electrons flowing in spin-orbit-coupled materials such as GaAs and InGaAs (refs 2, 3) and for laser light traversing dielectric junctions. Here we observe the spin Hall effect in a quantum-degenerate Bose gas, and use the resulting spin-dependent Lorentz forces to realize a cold-atom spin transistor. By engineering a spatially inhomogeneous spin-orbit coupling field for our quantum gas, we explicitly introduce and measure the requisite spin-dependent Lorentz forces, finding them to be in excellent agreement with our calculations. This 'atomtronic' transistor behaves as a type of velocity-insensitive adiabatic spin selector, with potential application in devices such as magnetic or inertial sensors. In addition, such techniques for creating and measuring the spin Hall effect are clear prerequisites for engineering topological insulators and detecting their associated quantized spin Hall effects in quantum gases. As implemented, our system realizes a laser-actuated analogue to the archetypal semiconductor spintronic device, the Datta-Das spin transistor.

  19. Anisotropic intrinsic spin Hall effect in quantum wires.

    Science.gov (United States)

    Cummings, A W; Akis, R; Ferry, D K

    2011-11-23

    We use numerical simulations to investigate the spin Hall effect in quantum wires in the presence of both Rashba and Dresselhaus spin-orbit coupling. We find that the intrinsic spin Hall effect is highly anisotropic with respect to the orientation of the wire, and that the nature of this anisotropy depends strongly on the electron density and the relative strengths of the Rashba and Dresselhaus spin-orbit couplings. In particular, at low densities, when only one subband of the quantum wire is occupied, the spin Hall effect is strongest for electron momentum along the [N110] axis, which is the opposite of what is expected for the purely 2D case. In addition, when more than one subband is occupied, the strength and anisotropy of the spin Hall effect can vary greatly over relatively small changes in electron density, which makes it difficult to predict which wire orientation will maximize the strength of the spin Hall effect. These results help to illuminate the role of quantum confinement in spin-orbit-coupled systems, and can serve as a guide for future experimental work on the use of quantum wires for spin-Hall-based spintronic applications.

  20. Planar Hall magnetoresistive aptasensor for thrombin detection.

    Science.gov (United States)

    Sinha, B; Ramulu, T S; Kim, K W; Venu, R; Lee, J J; Kim, C G

    2014-09-15

    The use of aptamer-based assays is an emerging and attractive approach in disease research and clinical diagnostics. A sensitive aptamer-based sandwich-type sensor is presented to detect human thrombin using a planar Hall magnetoresistive (PHR) sensor in cooperation with superparamagnetic labels. A PHR sensor has the great advantages of a high signal-to-noise ratio, a small offset voltage and linear response in the low-field region, allowing it to act as a high-resolution biosensor. In the system presented here, the sensor has an active area of 50 µm × 50 µm with a 10-nm gold layer deposited onto the sensor surface prior to the binding of thiolated DNA primary aptamer. A polydimethylsiloxane well of 600-µm radius and 1-mm height was prepared around the sensor surface to maintain the same specific area and volume for each sensor. The sensor response was traced in real time upon the addition of streptavidin-functionalized magnetic labels on the sensor. A linear response to the thrombin concentration in the range of 86 pM-8.6 µM and a lower detection limit down to 86 pM was achieved by the proposed present method with a sample volume consumption of 2 µl. The proposed aptasensor has a strong potential for application in clinical diagnosis.

  1. Acoustics in Halls for Speech and Music

    Science.gov (United States)

    Gade, Anders C.

    This chapter deals specifically with concepts, tools, and architectural variables of importance when designing auditoria for speech and music. The focus will be on cultivating the useful components of the sound in the room rather than on avoiding noise from outside or from installations, which is dealt with in Chap. 11. The chapter starts by presenting the subjective aspects of the room acoustic experience according to consensus at the time of writing. Then follows a description of their objective counterparts, the objective room acoustic parameters, among which the classical reverberation time measure is only one of many, but still of fundamental value. After explanations on how these parameters can be measured and predicted during the design phase, the remainder of the chapter deals with how the acoustic properties can be controlled by the architectural design of auditoria. This is done by presenting the influence of individual design elements as well as brief descriptions of halls designed for specific purposes, such as drama, opera, and symphonic concerts. Finally, some important aspects of loudspeaker installations in auditoria are briefly touched upon.

  2. Brand new hall in the main building

    CERN Multimedia

    Corinne Pralavorio

    2014-01-01

    The renovation of the UNIQA and post office premises is getting under way, with their reopening scheduled for the spring.   The renovation of the large hall in the main building (Building 500) has finally reached the home straight. As of this week, building contractors will get to work on the last part – the offices of UNIQA and La Poste. In the last week of November, the two concessions moved their offices across Route Scherrer to the same part of Building 510 where UBS was temporarily housed during the bank’s refurbishment. Their services were therefore unavailable for one day. The renovation work will last until the spring, with the new offices expected to open in May 2015. Between now and then, the windows and insulation will be completely refitted, with a view to reducing heat loss considerably, and, above all, the premises will be modernised to improve customer reception and service. For example, UNIQA’s new premises will feature a confidential area, guarantee...

  3. The integer quantum hall effect revisited

    Energy Technology Data Exchange (ETDEWEB)

    Michalakis, Spyridon [Los Alamos National Laboratory; Hastings, Matthew [Q STATION, CALIFORNIA

    2009-01-01

    For T - L x L a finite subset of Z{sup 2}, let H{sub o} denote a Hamiltonian on T with periodic boundary conditions and finite range, finite strength intetactions and a unique ground state with a nonvanishing spectral gap. For S {element_of} T, let q{sub s} denote the charge at site s and assume that the total charge Q = {Sigma}{sub s {element_of} T} q{sub s} is conserved. Using the local charge operators q{sub s}, we introduce a boundary magnetic flux in the horizontal and vertical direction and allow the ground state to evolve quasiadiabatically around a square of size one magnetic flux, in flux space. At the end of the evolution we obtain a trivial Berry phase, which we compare, via a method reminiscent of Stokes Theorem. to the Berry phase obtained from an evolution around an exponentially small loop near the origin. As a result, we show, without any averaging assumption, that the Hall conductance is quantized in integer multiples of e{sup 2}/h up to exponentially small corrections of order e{sup -L/{zeta}}, where {zeta}, is a correlation length that depends only on the gap and the range and strength of the interactions.

  4. Magnetized Epsilon-Near-Zero (ENZ) Structures: Hall Opacity, Hall Transparency, and One-Way Photonic Surface States

    CERN Document Server

    Davoyan, Arthur

    2013-01-01

    We study propagation of transverse-magnetic (TM) electromagnetic waves in the bulk and at the surface of magnetized epsilon-near-zero (ENZ) medium in a Voigt configuration. We reveal that in a certain range of material parameters novel regimes of wave propagation emerge: we show that the transparency of the medium can be altered with the magnetization leading either to magnetically induced Hall opacity or Hall transparency of the ENZ. In our theoretical study, we demonstrate that surface waves at the interface between either a transparent or an opaque Hall medium and a homogeneous medium may, under certain conditions, be predominantly one-way. Moreover, we predict that one-way photonic surface states may exist at the interface of an opaque Hall ENZ and a regular metal, giving rise to a possibility for backscattering immune wave propagation and isolation.

  5. Numerical analysis of Hall effect on the performance of magnetohydrodynamic heat shield system based on nonequilibrium Hall parameter model

    Science.gov (United States)

    Li, Kai; Liu, Jun; Liu, Weiqiang

    2017-01-01

    Magnetohydrodynamic (MHD) heat shield system, a novel thermal protection technique in the hypersonic field, has been paid much attention in recent years. In the real flight condition, not only the Lorentz force but also the Hall electric field is induced by the interaction between ionized air post shock and magnetic field. In order to analyze the action mechanisms of the Hall effect, numerical methods of coupling thermochemical nonequilibrium flow field with externally applied magnetic field as well as the induced electric field are constructed and validated. Based on the nonequilibrium model of Hall parameter, numerical simulations of the MHD heat shield system is conducted under two different magnetic induction strengths (B0=0.2 T, 0.5 T) on a reentry capsule forebody. Results show that, the Hall effect is the same under the two magnetic induction strengths when the wall is assumed to be conductive. For this case, with the Hall effect taken into account, the Lorentz force counter stream diminishes a lot and the circumferential component dominates, resulting that the heat flux and shock-off distance approach the case without MHD control. However, for the insulating wall, the Hall effect acts in different ways under these two magnetic induction strengths. For this case, with the Hall effect taken into account, the performance of MHD heat shield system approaches the case neglecting the Hall effect when B0 equals 0.2 T. Such performance becomes worse when B0 equals 0.5 T and the aerothermal environment on the capsule shoulder is even worse than the case without MHD control.

  6. María Teresa Calderón y Clément Thibaud. La majestad de los pueblos en la Nueva Granada y Venezuela, 1780-1832

    Directory of Open Access Journals (Sweden)

    Daniel Gutiérrez Ardila

    2011-01-01

    Full Text Available El libro de María Teresa Calderón y Clément Thibaud intenta responder a una cuestión que no por ser formulada en términos sencillos tiene un fácil desarrollo: si existe una historia del Estado, debe existir una historia de la soberanía. En otros términos, si resulta del todo inconveniente proyectar el Estado weberiano sobre el pasado como una entelequia ahistórica, no puede sostenerse sin graves consecuencias (el relato de la decepción democrática que hay un tránsito inmediato de la soberanía del rey a la soberanía de la nación o del pueblo. Entre ambos paradigmas se desliza un periodo híbrido en el que la majestad real contribuye a la comprensión y a la elaboración por parte de los revolucionarios de la nueva baza de la legitimidad.

  7. Leiomioma esofágico: Experiencia con diez casos operados en el "Hospital Dr. Rafael Ángel Calderón Guardia" Esophageal leiomyoma: Experience with nine surgical patients

    Directory of Open Access Journals (Sweden)

    Giovanna Mainieri-Breedy

    2012-09-01

    Full Text Available Objetivo: informar la experiencia adquirida con la cirugía para leiomiomas esofágicos en el Servicio de Cirugía de Tórax del Hospital Dr. R. A. Calderón Guardia. Métodos: durante el período de 12 años comprendido entre 1999 y 2011, fueron referidos 14 pacientes con tumores submucosos del esófago al Servicio de Cirugía de Tórax del Hospital Calderón Guardia. En cuatro pacientes asintomáticos con tumores pequeños se decidió observar, y diez fueron operados, confirmándose el diagnóstico histológico de leiomioma. Previa autorización del Comité de Ética del Hospital, se revisaron los expedientes clínicos, analizando las características personales, los síntomas, los métodos de diagnóstico, el tratamiento quirúrgico y la evolución de los pacientes operados. Resultados: se encontró que de los diez pacientes operados, ocho fueron varones, en edades entre los 38 y 71 años, con un promedio de 56 años. El síntoma principal fue disfagia, pero en 3 casos el tumor fue un hallazgo incidental de una endoscopia de rutina. El método de detección en todos los casos fue la endoscopia en la que se describió un tumor submucoso o una compresión extrínseca de la pared esofágica. El ultrasonido endoscópico se correlacionó con un tumor originado en la cuarta capa, posible leiomioma. En dos casos, debido a las dimensiones de la lesión, se planteó la posibilidad de malignidad. La tumoración se intervino en nueve casos por toracotomía y en uno, por laparotomía. En 7 casos se enucleó sin que se abriera la mucosa, en dos se realizó esofagectomía parcial con anastomosis y parche de diafragma, y en un caso, excepcional, la tumoración se extendía desde el esófago cervical hasta la unión esófago-gástrica, de manera que se realizó una esofagectomía total, con ascenso gástrico y anastomosis cervical. No hubo ningún caso de mortalidad. Un paciente presentó una pequeña fuga de la anastomosis, la cual resolvió espont

  8. Reactor Safety Planning for Prometheus Project, for Naval Reactors Information

    Energy Technology Data Exchange (ETDEWEB)

    P. Delmolino

    2005-05-06

    The purpose of this letter is to submit to Naval Reactors the initial plan for the Prometheus project Reactor Safety work. The Prometheus project is currently developing plans for cold physics experiments and reactor prototype tests. These tests and facilities may require safety analysis and siting support. In addition to the ground facilities, the flight reactor units will require unique analyses to evaluate the risk to the public from normal operations and credible accident conditions. This letter outlines major safety documents that will be submitted with estimated deliverable dates. Included in this planning is the reactor servicing documentation and shipping analysis that will be submitted to Naval Reactors.

  9. REACTOR GROUT THERMAL PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.; Qureshi, Z.; Restivo, M.; Guerrero, H.

    2011-01-28

    Savannah River Site has five dormant nuclear production reactors. Long term disposition will require filling some reactor buildings with grout up to ground level. Portland cement based grout will be used to fill the buildings with the exception of some reactor tanks. Some reactor tanks contain significant quantities of aluminum which could react with Portland cement based grout to form hydrogen. Hydrogen production is a safety concern and gas generation could also compromise the structural integrity of the grout pour. Therefore, it was necessary to develop a non-Portland cement grout to fill reactors that contain significant quantities of aluminum. Grouts generate heat when they set, so the potential exists for large temperature increases in a large pour, which could compromise the integrity of the pour. The primary purpose of the testing reported here was to measure heat of hydration, specific heat, thermal conductivity and density of various reactor grouts under consideration so that these properties could be used to model transient heat transfer for different pouring strategies. A secondary purpose was to make qualitative judgments of grout pourability and hardened strength. Some reactor grout formulations were unacceptable because they generated too much heat, or started setting too fast, or required too long to harden or were too weak. The formulation called 102H had the best combination of characteristics. It is a Calcium Alumino-Sulfate grout that contains Ciment Fondu (calcium aluminate cement), Plaster of Paris (calcium sulfate hemihydrate), sand, Class F fly ash, boric acid and small quantities of additives. This composition afforded about ten hours of working time. Heat release began at 12 hours and was complete by 24 hours. The adiabatic temperature rise was 54 C which was within specification. The final product was hard and displayed no visible segregation. The density and maximum particle size were within specification.

  10. Scaleable, High Efficiency Microchannel Sabatier Reactor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A Microchannel Sabatier Reactor System (MSRS) consisting of cross connected arrays of isothermal or graded temperature reactors is proposed. The reactor array...

  11. Observational evidence for Hall drift and Hall waves in the crusts of isolated young neutron stars

    CERN Document Server

    Xie, Yi

    2013-01-01

    The observed long-term spin-down evolution of isolated radio pulsars cannot be explained by the standard magnetic dipole radiation with a constant braking torque. However how and why the torque varies still remains controversial, which is an outstanding problem in our understanding of neutron stars. Many pulsars have been observed with significant long-term changes of their spin-down rates modulated by quasi-periodic oscillations. Applying the phenomenological model of pulsar timing noise we developed recently to the observed precise pulsar timing data, here we show that, the Hall drift and Hall waves in their crusts are responsible for the observed long-term evolution of the spin-down rates and their quasi-periodic modulations, respectively. Consequently the majority of dipolar magnetic field lines are restricted to their outer crusts, rather than penetrating the cores of the neutron stars. Understanding of the nature of pulsar timing noise not only reveals the interior physics of neutron stars, but also all...

  12. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Takeshi; Iida, Masaaki; Moriki, Yasuyuki

    1994-10-18

    A reactor core is divided into a plurality of coolants flowrate regions, and electromagnetic pumps exclusively used for each of the flowrate regions are disposed to distribute coolants flowrates in the reactor core. Further, the flowrate of each of the electromagnetic pumps is automatically controlled depending on signals from a temperature detector disposed at the exit of the reactor core, so that the flowrate of the region can be controlled optimally depending on the burning of reactor core fuels. Then, the electromagnetic pumps disposed for every divided region are controlled respectively, so that the coolants flowrate distribution suitable to each of the regions can be attained. Margin for fuel design is decreased, fuels are used effectively, as well as an operation efficiency can be improved. Moreover, since the electromagnetic pump has less flow resistance compared with a mechanical type pump, and flow resistance of the reactor core flowrate control mechanism is eliminated, greater circulating flowrate can be ensured after occurrence of accident in a natural convection using a buoyancy of coolants utilizable for after-heat removal as a driving force. (N.H.).

  13. Mixed-State Hall Effect in Chemically-Substituted YBa_2Cu_3O_7-δ Single Crystals

    Science.gov (United States)

    Han, S. H.; Herrmann, J.; Gajewski, D. A.; Paulius, L. M.; Almasan, C. C.; Maple, M. B.

    1996-03-01

    Longitudinal resistivity and Hall effect measurements on single crystals of Y_1-xPr_xBa_2Cu_3O_7-δ, YBa_2Cu_3O_7-y, and YBa_2Cu_3-zZn_zO_7-δ in the mixed-state reveal a ``negative Hall anomaly'' below T_c. The negative Hall signal decreases with decreasing CuO2 plane hole concentration and increasing disorder. The Hall conductivity has been analyzed using the expression σ_xy = C_1/B + C_2B + C_3, where C_1/B and C_2B are associated with the motion of the magnetic vortices and of the quasiparticles in the vortex cores, respectively. We extracted the scaling behavior of the parameters C1 and C2 with temperature in the form of A(1-T/T_c)^α and B_1(T_c/T)^β + B_2, respectively. We discovered a delayed onset of a finite transverse resistance with increasing applied magnetic fields, as compared to the longitudinal resistance. The results will be discussed in terms of a model involving quasiparticle density fluctuations in the vortex cores. This work was supported by the U. S. Department of Energy DE-FG03-86ER-45230. Financial support from LANL/INCOR (UC-91-6-A-110) (SHH) and DAAD (JH) is acknowledged. *Present Address: Department of Physics, Western Michigan University **Present Address: Department of Physics, Kent State University

  14. Eigenanalysis of Ideal Hall MHD Turbulence

    Science.gov (United States)

    Fu, T.; Shebalin, J. V.

    2011-12-01

    Ideal, incompressible, homogeneous, Hall magnetohydrodynamic (HMHD) turbulence may be investigated through a Fourier spectral method. In three-dimensional periodic geometry, the independent Fourier coefficients represent a canonical ensemble described by a Gaussian probability density. The canonical ensemble is based on the conservation of three invariants: total energy, generalized helicity, and magnetic helicity. Generalized helicity in HMHD takes the place of cross helicity in MHD. The invariants determine the modal probability density giving the spectral structure and equilibrium statistics of ideal HMHD, which are compared to known MHD results. New results in absolute equilibrium ensemble theory are derived using a novel approach that involves finding the eigenvalues of a Hermitian covariance matrix for each modal probability density. The associated eigenvectors transform the original phase space variables into eigenvariables through a special unitary transformation. These are the normal modes which facilitate the analysis of ideal HMHD non-linear dynamics. The eigenanalysis predicts that the low wavenumber modes with very small eigenvalues may have mean values that are large compared to their standard deviations, contrary to the ideal ensemble prediction of zero mean values. (Expectation values may also be relatively large at the highest wave numbers, but the addition of even small levels of dissipation removes any relevance this may have for real-world turbulence.) This behavior is non-ergodic over very long times for a numerical simulation and is termed 'broken ergodicity'. For fixed values of the ideal invariants, the effect is seen to be enhanced with increased numerical grid size. Broken ergodicity at low wave number modes gives rise to large-scale, quasi-stationary, coherent structure. Physically, this corresponds to plasma relaxation to force-free states. For real HMHD turbulence with dissipation, broken ergodicity and coherent structure are still

  15. Azimuthal Spoke Propagation in Hall Effect Thrusters

    Science.gov (United States)

    Sekerak, Michael J.; Longmier, Benjamin W.; Gallimore, Alec D.; Brown, Daniel L.; Hofer, Richard R.; Polk, James E.

    2013-01-01

    Spokes are azimuthally propagating perturbations in the plasma discharge of Hall Effect Thrusters (HETs) that travel in the E x B direction and have been observed in many different systems. The propagation of azimuthal spokes are investigated in a 6 kW HET known as the H6 using ultra-fast imaging and azimuthally spaced probes. A spoke surface is a 2-D plot of azimuthal light intensity evolution over time calculated from 87,500 frames/s videos. The spoke velocity has been determined using three methods with similar results: manual fitting of diagonal lines on the spoke surface, linear cross-correlation between azimuthal locations and an approximated dispersion relation. The spoke velocity for three discharge voltages (300, 400 and 450 V) and three anode mass flow rates (14.7, 19.5 and 25.2 mg/s) yielded spoke velocities between 1500 and 2200 m/s across a range of normalized magnetic field settings. The spoke velocity was inversely dependent on magnetic field strength for low B-field settings and asymptoted at B-field higher values. The velocities and frequencies are compared to standard drifts and plasma waves such as E x B drift, electrostatic ion cyclotron, magnetosonic and various drift waves. The empirically approximated dispersion relation yielded a characteristic velocity that matched the ion acoustic speed for 5 eV electrons that exist in the near-anode and near-field plume regions of the discharge channel based on internal measurements. Thruster performance has been linked to operating mode where thrust-to-power is maximized when azimuthal spokes are present so investigating the underlying mechanism of spokes will benefit thruster operation.

  16. Mode Transitions in Hall Effect Thrusters

    Science.gov (United States)

    Sekerak, Michael J.; Longmier, Benjamin W.; Gallimore, Alec D.; Brown, Daniel L.; Hofer, Richard R.; Polk, James E.

    2013-01-01

    Mode transitions have been commonly observed in Hall Effect Thruster (HET) operation where a small change in a thruster operating parameter such as discharge voltage, magnetic field or mass flow rate causes the thruster discharge current mean value and oscillation amplitude to increase significantly. Mode transitions in a 6-kW-class HET called the H6 are induced by varying the magnetic field intensity while holding all other operating parameters constant and measurements are acquired with ion saturation probes and ultra-fast imaging. Global and local oscillation modes are identified. In the global mode, the entire discharge channel oscillates in unison and azimuthal perturbations (spokes) are either absent or negligible. Downstream azimuthally spaced probes show no signal delay between each other and are very well correlated to the discharge current signal. In the local mode, signals from the azimuthally spaced probes exhibit a clear delay indicating the passage of "spokes" and are not well correlated to the discharge current. These spokes are localized oscillations propagating in the ExB direction that are typically 10-20% of the mean value. In contrast, the oscillations in the global mode can be 100% of the mean value. The transition between global and local modes occurs at higher relative magnetic field strengths for higher mass flow rates or higher discharge voltages. The thrust is constant through mode transition but the thrust-to-power decreased by 25% due to increasing discharge current. The plume shows significant differences between modes with the global mode significantly brighter in the channel and the near-field plasma plume as well as exhibiting a luminous spike on thruster centerline. Mode transitions provide valuable insight to thruster operation and suggest improved methods for thruster performance characterization.

  17. Reactor Structural Materials: Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R

    2000-07-01

    The objectives of SCK-CEN's R and D programme on Rector Pressure Vessel (RPV) Steels are:(1) to complete the fracture toughness data bank of various reactor pressure vessel steels by using precracked Charpy specimens that were tested statically as well as dynamically; (2) to implement the enhanced surveillance approach in a user-friendly software; (3) to improve the existing reconstitution technology by reducing the input energy (short cycle welding) and modifying the stud geometry. Progress and achievements in 1999 are reported.

  18. Operation of Reactor

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    3.1 Annual Report of SPR Operation Chu Shaochu Having overseen by National Nuclear Safety Administration and specialists, the reactor restarted up successfully after Safety renovation on April 16, 1996. In August 1996 the normal operation of SPR was approved by the authorities of Naitonal Nuclear Safety Administration. 1 Operation status In 1996, the reactor operated safely for 40 d and the energy released was about 137.3 MW·d. The operation status of SPR is shown in table 1. The reactor started up to higher power (power more than 1 MW) and lower power (for physics experiments) 4 times and 14 times respectively. Measurement of control rod efficiency and other measurement tasks were 2 times and 5 times respectively.

  19. Nuclear Rocket Engine Reactor

    CERN Document Server

    Lanin, Anatoly

    2013-01-01

    The development of a nuclear rocket engine reactor (NRER ) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  20. Thermionic Reactor Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1994-08-01

    Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their (thermionic reactor) performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling.

  1. An Overview of Reactor Concepts, a Survey of Reactor Designs.

    Science.gov (United States)

    1985-02-01

    Public Affairs Office and is releasaole to the National Technical Information Services (NTIS). At NTIS, it will be available to the general public...Reactors that use deu- terium (heavy water) as a coolant can use natural uranium as a fuel. The * Canadian reactor, CANDU , utilizes this concept...reactor core at the top and discharged at the Dotton while the reactor is in operation. The discharged fuel can then b inspected to see if it can De used

  2. Oscillatory flow chemical reactors

    Directory of Open Access Journals (Sweden)

    Slavnić Danijela S.

    2014-01-01

    Full Text Available Global market competition, increase in energy and other production costs, demands for high quality products and reduction of waste are forcing pharmaceutical, fine chemicals and biochemical industries, to search for radical solutions. One of the most effective ways to improve the overall production (cost reduction and better control of reactions is a transition from batch to continuous processes. However, the reactions of interests for the mentioned industry sectors are often slow, thus continuous tubular reactors would be impractically long for flow regimes which provide sufficient heat and mass transfer and narrow residence time distribution. The oscillatory flow reactors (OFR are newer type of tube reactors which can offer solution by providing continuous operation with approximately plug flow pattern, low shear stress rates and enhanced mass and heat transfer. These benefits are the result of very good mixing in OFR achieved by vortex generation. OFR consists of cylindrical tube containing equally spaced orifice baffles. Fluid oscillations are superimposed on a net (laminar flow. Eddies are generated when oscillating fluid collides with baffles and passes through orifices. Generation and propagation of vortices create uniform mixing in each reactor cavity (between baffles, providing an overall flow pattern which is close to plug flow. Oscillations can be created by direct action of a piston or a diaphragm on fluid (or alternatively on baffles. This article provides an overview of oscillatory flow reactor technology, its operating principles and basic design and scale - up characteristics. Further, the article reviews the key research findings in heat and mass transfer, shear stress, residence time distribution in OFR, presenting their advantages over the conventional reactors. Finally, relevant process intensification examples from pharmaceutical, polymer and biofuels industries are presented.

  3. Perspectives on reactor safety

    Energy Technology Data Exchange (ETDEWEB)

    Haskin, F.E. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Camp, A.L. [Sandia National Labs., Albuquerque, NM (United States)

    1994-03-01

    The US Nuclear Regulatory Commission (NRC) maintains a technical training center at Chattanooga, Tennessee to provide appropriate training to both new and experienced NRC employees. This document describes a one-week course in reactor, safety concepts. The course consists of five modules: (1) historical perspective; (2) accident sequences; (3) accident progression in the reactor vessel; (4) containment characteristics and design bases; and (5) source terms and offsite consequences. The course text is accompanied by slides and videos during the actual presentation of the course.

  4. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2002-04-01

    The activities of SCK-CEN's Reactor Materials Research Department for 2001 are summarised. The objectives of the department are: (1) to evaluate the integrity and behaviour of structural materials used in nuclear power industry; (2) to conduct research to unravel and understand the parameters that determine the material behaviour under or after irradiation; (3) to contribute to the interpretation, the modelling of the material behaviour and to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the department are focussed on studies concerning (1) Irradiation Assisted Stress Corrosion Cracking (IASCC); (2) nuclear fuel; and (3) Reactor Pressure Vessel Steel.

  5. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on fusion reactor materials includes: (1) the study of the mechanical behaviour of structural materials under neutron irradiation (including steels, inconel, molybdenum, chromium); (2) the determination and modelling of the characteristics of irradiated first wall materials such as beryllium; (3) the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; (4) the study of the dismantling and waste disposal strategy for fusion reactors.; (5) a feasibility study for the testing of blanket modules under neutron radiation. Main achievements in these topical areas in the year 1999 are summarised.

  6. High temperature Hall measurement setup for thin film characterization

    Science.gov (United States)

    Adnane, L.; Gokirmak, A.; Silva, H.

    2016-07-01

    Hall measurement using the van der Pauw technique is a common characterization approach that does not require patterning of contacts. Measurements of the Hall voltage and electrical resistivity lead to the product of carrier mobility and carrier concentration (Hall coefficient) which can be decoupled through transport models. Based on the van der Paw method, we have developed an automated setup for Hall measurements from room temperature to ˜500 °C of semiconducting thin films of a wide resistivity range. The resistivity of the film and Hall coefficient is obtained from multiple current-voltage (I-V) measurements performed using a semiconductor parameter analyzer under applied constant "up," zero, and "down" magnetic field generated with two neodymium permanent magnets. The use of slopes obtained from multiple I-Vs for the three magnetic field conditions offer improved accuracy. Samples are preferred in square shape geometry and can range from 2 mm to 25 mm side length. Example measurements of single-crystal silicon with known doping concentration show the accuracy and reliability of the measurement.

  7. Stability of Hall equilibria in neutron star crusts

    CERN Document Server

    Marchant, Pablo; Valdivia, Juan Alejandro; Hoyos, Jaime H

    2014-01-01

    In the solid crusts of neutron stars, the advection of the magnetic field by the current-carrying electrons, an effect known as Hall drift, should play a very important role as the ions remain essentially fixed (as long as the solid does not break). Although Hall drift preserves the magnetic field energy, it has been argued that it may drive a turbulent cascade to scales at which Ohmic dissipation becomes effective, allowing a much faster decay in objects with very strong fields. On the other hand, it has been found that there are "Hall equilibria", i.e., field configurations that are unaffected by Hall drift. Here, we address the crucial question of the stability of these equilibria through axially symmetric (2D) numerical simulations of Hall drift and Ohmic diffusion, with the simplifying assumption of uniform electron density and conductivity. We demonstrate the 2D-stability of a purely poloidal equilibrium, for which Ohmic dissipation makes the field evolve towards an attractor state through adjacent stab...

  8. Suitable reverberation times for halls for rock and pop music.

    Science.gov (United States)

    Adelman-Larsen, Niels Werner; Thompson, Eric R; Gade, Anders C

    2010-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of popular music, including rock and pop. Objective measurements were made of the acoustics of 20 rock music venues in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers as expert listeners. Correlations between the measurements show that clarity, including bass frequencies down to 63 Hz, is important for the general impression of the acoustics of the hall. The best-rated halls in the study have reverberation times that are approximately frequency independent from 0.6 to 1.2 s for hall volumes from 1000 to 6000 m(3). The worst rated halls in the study had significantly higher reverberation times in the 63 and 125 Hz bands. Since most audiences at rock concerts are standing, absorption coefficients were measured with a standing audience from 63 Hz to 4 kHz. These measurements showed that a standing audience absorbs about five times as much energy in mid-/high-frequency bands as in low-frequency bands.

  9. Reconnection dynamics with secondary tearing instability in compressible Hall plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Z. W., E-mail: zwma@zju.edu.cn; Wang, L. C.; Li, L. J. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China)

    2015-06-15

    The dynamics of a secondary tearing instability is systematically investigated based on compressible Hall magnetohydrodynamic. It is found that in the early nonlinear phase of magnetic reconnection before onset of the secondary tearing instability, the geometry of the magnetic field in the reconnection region tends to form a Y-type structure in a weak Hall regime, instead of an X-type structure in a strong Hall regime. A new scaling law is found that the maximum reconnection rate in the early nonlinear stage is proportional to the square of the ion inertial length (γ∝d{sub i}{sup 2}) in the weak Hall regime. In the late nonlinear phase, the thin elongated current sheet associated with the Y-type geometry of the magnetic field breaks up to form a magnetic island due to a secondary tearing instability. After the onset of the secondary tearing mode, the reconnection rate is substantially boosted by the formation of the X-type geometries of magnetic field in the reconnection regions. With a strong Hall effect, the maximum reconnection rate linearly increases with the increase of the ion inertial length (γ∝d{sub i})

  10. The local nature of incompressibility of quantum Hall effect

    Science.gov (United States)

    Kendirlik, E. M.; Sirt, S.; Kalkan, S. B.; Ofek, N.; Umansky, V.; Siddiki, A.

    2017-01-01

    Since the experimental realization of the integer quantum Hall effect in a two-dimensional electron system, the interrelation between the conductance quantization and the topological properties of the system has been investigated. Assuming that the two-dimensional electron system is described by a Bloch Hamiltonian, system is insulating in the bulk of sample throughout the quantum Hall plateau due to a magnetic field induced energy gap. Meanwhile, the system is conducting at the edges resembling a 2+1 dimensional topological insulator without time-reversal symmetry. Here, by our magneto-transport measurements performed on GaAs/AlGaAs high purity Hall bars with two inner contacts we show that incompressible strips formed at the edges result in Hall quantization, even if the bulk is compressible. Consequently, the relationship between the quantum Hall effect and topological bulk insulator breaks for specific field intervals within the plateaus. The measurement of conducting bulk, strongly challenges all existing single-particle theories. PMID:28071652

  11. Higher (odd dimensional quantum Hall effect and extended dimensional hierarchy

    Directory of Open Access Journals (Sweden)

    Kazuki Hasebe

    2017-07-01

    Full Text Available We demonstrate dimensional ladder of higher dimensional quantum Hall effects by exploiting quantum Hall effects on arbitrary odd dimensional spheres. Non-relativistic and relativistic Landau models are analyzed on S2k−1 in the SO(2k−1 monopole background. The total sub-band degeneracy of the odd dimensional lowest Landau level is shown to be equal to the winding number from the base-manifold S2k−1 to the one-dimension higher SO(2k gauge group. Based on the chiral Hopf maps, we clarify the underlying quantum Nambu geometry for odd dimensional quantum Hall effect and the resulting quantum geometry is naturally embedded also in one-dimension higher quantum geometry. An origin of such dimensional ladder connecting even and odd dimensional quantum Hall effects is illuminated from a viewpoint of the spectral flow of Atiyah–Patodi–Singer index theorem in differential topology. We also present a BF topological field theory as an effective field theory in which membranes with different dimensions undergo non-trivial linking in odd dimensional space. Finally, an extended version of the dimensional hierarchy for higher dimensional quantum Hall liquids is proposed, and its relationship to quantum anomaly and D-brane physics is discussed.

  12. Higher (odd) dimensional quantum Hall effect and extended dimensional hierarchy

    Science.gov (United States)

    Hasebe, Kazuki

    2017-07-01

    We demonstrate dimensional ladder of higher dimensional quantum Hall effects by exploiting quantum Hall effects on arbitrary odd dimensional spheres. Non-relativistic and relativistic Landau models are analyzed on S 2 k - 1 in the SO (2 k - 1) monopole background. The total sub-band degeneracy of the odd dimensional lowest Landau level is shown to be equal to the winding number from the base-manifold S 2 k - 1 to the one-dimension higher SO (2 k) gauge group. Based on the chiral Hopf maps, we clarify the underlying quantum Nambu geometry for odd dimensional quantum Hall effect and the resulting quantum geometry is naturally embedded also in one-dimension higher quantum geometry. An origin of such dimensional ladder connecting even and odd dimensional quantum Hall effects is illuminated from a viewpoint of the spectral flow of Atiyah-Patodi-Singer index theorem in differential topology. We also present a BF topological field theory as an effective field theory in which membranes with different dimensions undergo non-trivial linking in odd dimensional space. Finally, an extended version of the dimensional hierarchy for higher dimensional quantum Hall liquids is proposed, and its relationship to quantum anomaly and D-brane physics is discussed.

  13. Spin Hall effects in mesoscopic Pt films with high resistivity

    Science.gov (United States)

    Qin, Chuan; Luo, Yongming; Zhou, Chao; Cai, Yunjiao; Jia, Mengwen; Chen, Shuhan; Wu, Yizheng; Ji, Yi

    2016-10-01

    The energy efficiency of the spin Hall effects (SHE) can be enhanced if the electrical conductivity is decreased without sacrificing the spin Hall conductivity. The resistivity of Pt films can be increased to 150-300 µΩ · cm by mesoscopic lateral confinement, thereby decreasing the conductivity. The SHE and inverse spin Hall effects (ISHE) in these mesoscopic Pt films are explored at 10 K by using the nonlocal spin injection/detection method. All relevant physical quantities are determined in situ on the same substrate, and a quantitative approach is developed to characterize all processes effectively. Extensive measurements with various Pt thickness values reveal an upper limit for the Pt spin diffusion length: {λ\\text{pt}}   ⩽  0.8 nm. The average product of {λ\\text{pt}} and the Pt spin Hall angle {α\\text{H}} is substantial: {α\\text{H}}{λ\\text{pt}}   =  (0.142  ±  0.040) nm for 4 nm thick Pt, though a gradual decrease is observed at larger Pt thickness. The results suggest enhanced spin Hall effects in resistive mesoscopic Pt films.

  14. Concert halls with strong lateral reflections enhance musical dynamics.

    Science.gov (United States)

    Pätynen, Jukka; Tervo, Sakari; Robinson, Philip W; Lokki, Tapio

    2014-03-25

    One of the most thrilling cultural experiences is to hear live symphony-orchestra music build up from a whispering passage to a monumental fortissimo. The impact of such a crescendo has been thought to depend only on the musicians' skill, but here we show that interactions between the concert-hall acoustics and listeners' hearing also play a major role in musical dynamics. These interactions contribute to the shoebox-type concert hall's established success, but little prior research has been devoted to dynamic expression in this three-part transmission chain as a complete system. More forceful orchestral playing disproportionately excites high frequency harmonics more than those near the note's fundamental. This effect results in not only more sound energy, but also a different tone color. The concert hall transmits this sound, and the room geometry defines from which directions acoustic reflections arrive at the listener. Binaural directional hearing emphasizes high frequencies more when sound arrives from the sides of the head rather than from the median plane. Simultaneously, these same frequencies are emphasized by higher orchestral-playing dynamics. When the room geometry provides reflections from these directions, the perceived dynamic range is enhanced. Current room-acoustic evaluation methods assume linear behavior and thus neglect this effect. The hypothesis presented here is that the auditory excitation by reflections is emphasized with an orchestra forte most in concert halls with strong lateral reflections. The enhanced dynamic range provides an explanation for the success of rectangularly shaped concert-hall geometry.

  15. NASA HERMeS Hall Thruster Electrical Configuration Characterization

    Science.gov (United States)

    Peterson, Peter Y.; Kamhawi, Hani; Huang, Wensheng; Yim, John; Herman, Daniel; Williams, George; Gilland, James; Hofer, Richard

    2015-01-01

    The NASA Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5 kW Technology Demonstration Unit-1 (TDU-1) Hall thruster has been the subject of extensive technology maturation in preparation for development into a flight ready propulsion system. Part of the technology maturation was to test the TDU-1 thruster in several ground based electrical configurations to assess the thruster robustness and suitability to successful in-space operation. The ground based electrical configuration testing has recently been demonstrated as an important step in understanding and assessing how a Hall thruster may operate differently in-space compared to ground based testing, and to determine the best configuration to conduct development and qualification testing. This paper describes the electrical configuration testing of the HERMeS TDU-1 Hall thruster in NASA Glenn Research Center's Vacuum Facility 5. The three electrical configurations examined were 1) thruster body tied to facility ground, 2) thruster floating, and 3) thruster body electrically tied to cathode common. The HERMeS TDU-1 Hall thruster was also configured with two different exit plane boundary conditions, dielectric and conducting, to examine the influence on the electrical configuration characterization.

  16. The local nature of incompressibility of quantum Hall effect

    Science.gov (United States)

    Kendirlik, E. M.; Sirt, S.; Kalkan, S. B.; Ofek, N.; Umansky, V.; Siddiki, A.

    2017-01-01

    Since the experimental realization of the integer quantum Hall effect in a two-dimensional electron system, the interrelation between the conductance quantization and the topological properties of the system has been investigated. Assuming that the two-dimensional electron system is described by a Bloch Hamiltonian, system is insulating in the bulk of sample throughout the quantum Hall plateau due to a magnetic field induced energy gap. Meanwhile, the system is conducting at the edges resembling a 2+1 dimensional topological insulator without time-reversal symmetry. Here, by our magneto-transport measurements performed on GaAs/AlGaAs high purity Hall bars with two inner contacts we show that incompressible strips formed at the edges result in Hall quantization, even if the bulk is compressible. Consequently, the relationship between the quantum Hall effect and topological bulk insulator breaks for specific field intervals within the plateaus. The measurement of conducting bulk, strongly challenges all existing single-particle theories.

  17. Nonlinear Quantum Hall effects in Rarita-Schwinger gas

    CERN Document Server

    Luo, Xi; Wan, Xiangang; Yu, Yue

    2016-01-01

    Emergence of higher spin relativistic fermionic materials becomes a new favorite in the study of condensed matter physics. Massive Rarita-Schwinger 3/2-spinor was known owning very exotic properties, such as the superluminal fermionic modes and even being unstable in an external magnetic field. Due to the superluminal modes and the non-trivial constraints on the Rarita-Schwinger gas, we exposit anomalous properties of the Hall effects in (2+1)-dimensions which subvert the well-known quantum Hall paradigms. First, the Hall conductance of a pure Rarita-Schwinger gas is step-like but not plateau-quantized, instead of the linear dependence on the filling factor for a pure spin-1/2 Dirac gas. In reality, the Hall conductance of the Dirac gas is of quantized integer plateaus with the unit $\\frac{e^2}h$ due to the localization away from the Landau level centers. If the general localization rule is applicable to the disordered Rarita-Schwinger gas, the Hall plateaus are also expected to appear but they are nonlinearl...

  18. Spin Hall torques generated by rare-earth thin films

    Science.gov (United States)

    Reynolds, Neal; Jadaun, Priyamvada; Heron, John T.; Jermain, Colin L.; Gibbons, Jonathan; Collette, Robyn; Buhrman, R. A.; Schlom, D. G.; Ralph, D. C.

    2017-02-01

    We report an initial experimental survey of spin Hall torques generated by the rare-earth metals Gd, Dy, Ho, and Lu, along with comparisons to first-principles calculations of their spin Hall conductivities. Using spin torque ferromagnetic resonance (ST-FMR) measurements and dc-biased ST-FMR, we estimate lower bounds for the spin Hall torque ratio, ξSH, of ≈0.04 for Gd, ≈0.05 for Dy, ≈0.14 for Ho, and ≈0.014 for Lu. The variations among these elements are qualitatively consistent with results from first principles [density-functional theory (DFT) in the local density approximation with a Hubbard-U correction]. The DFT calculations indicate that the spin Hall conductivity is enhanced by the presence of the partially filled f orbitals in Dy and Ho, which suggests a strategy to further strengthen the contribution of the f orbitals to the spin Hall effect by shifting the electron chemical potential.

  19. High Flux Isotope Reactor (HFIR)

    Data.gov (United States)

    Federal Laboratory Consortium — The HFIR at Oak Ridge National Laboratory is a light-water cooled and moderated reactor that is the United States’ highest flux reactor-based neutron source. HFIR...

  20. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

    Haselow, J.S.; Price, V.; Stephenson, D.E.; Bledsoe, H.W.; Looney, B.B.

    1989-12-01

    The Savannah River Site (SRS) produces nuclear materials, primarily plutonium and tritium, to meet the requirements of the Department of Defense. These products have been formed in nuclear reactors that were built during 1950--1955 at the SRS. K, L, and P reactors are three of five reactors that have been used in the past to produce the nuclear materials. All three of these reactors discontinued operation in 1988. Currently, intense efforts are being extended to prepare these three reactors for restart in a manner that protects human health and the environment. To document that restarting the reactors will have minimal impacts to human health and the environment, a three-volume Reactor Operations Environmental Impact Document has been prepared. The document focuses on the impacts of restarting the K, L, and P reactors on both the SRS and surrounding areas. This volume discusses the geology, seismology, and subsurface hydrology. 195 refs., 101 figs., 16 tabs.