Sample records for magnetism materials surface

  1. System and method for non-destructive evaluation of surface characteristics of a magnetic material

    DOE Patents [OSTI]

    Jiles, David C. (Ames, IA); Sipahi, Levent B. (Ames, IA)

    1994-05-17T23:59:59.000Z

    A system and a related method for non-destructive evaluation of the surface characteristics of a magnetic material. The sample is excited by an alternating magnetic field. The field frequency, amplitude and offset are controlled according to a predetermined protocol. The Barkhausen response of the sample is detected for the various fields and offsets and is analyzed. The system produces information relating to the frequency content, the amplitude content, the average or RMS energy content, as well as count rate information, for each of the Barkhausen responses at each of the excitation levels applied during the protocol. That information provides a contiguous body of data, heretofore unavailable, which can be analyzed to deduce information about the surface characteristics of the material at various depths below the surface.

  2. Nanostructured magnetic materials

    E-Print Network [OSTI]

    Chan, Keith T.

    2011-01-01T23:59:59.000Z

    Magnetism and Magnetic Materials Conference, Atlanta, GA (Nanostructured Magnetic Materials by Keith T. Chan Doctor ofinduced by a Si-based material occurs at a Si/Ni interface

  3. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Large Magnetization at Carbon Surfaces Large Magnetization at Carbon Surfaces Print Wednesday, 31 August 2011 00:00 From organic matter to pencil lead, carbon is a versatile...

  4. MHD problems in free liquid surfaces as plasma-facing materials in magnetically confined reactors

    E-Print Network [OSTI]

    Harilal, S. S.

    -producing magnetically confined reactors. Solid PFC cannot be reliably used because of the large erosion losses during is in 5 T, the density r is g/cm3 , and the liquid metal is lithium. The velocity V0 and thickness/depth h

  5. Magnetic nanoworms Systematic Surface Engineering of Magnetic Nanoworms

    E-Print Network [OSTI]

    Bhatia, Sangeeta

    Magnetic nanoworms Systematic Surface Engineering of Magnetic Nanoworms for in vivo Tumor Targeting and Engineering Program Department of Chemistry and Biochemistry University of California, San Diego 9500 Gilman magnetic materials nanoworms peptides tumor targeting 694 ß 2009 Wiley-VCH Verlag GmbH & Co. KGa

  6. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure...

  7. Superconductivity and Magnetism: Materials Properties

    E-Print Network [OSTI]

    .g. within high-Tc superconductivity, magnetic superconductors, MgB2, CMR materials, nanomagnetism and spin#12;#12;Superconductivity and Magnetism: Materials Properties and Developments #12;Copyright 2003 Risø National Laboratory Roskilde, Denmark ISBN 87-550-3244-3 ISSN 0907-0079 #12;Superconductivity

  8. Magnetic Materials Group

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for magnetic circular dichroism (XMCD) and magnetic scattering experiments. Sunset Yellow 6-ID-B: Resonant and In-Field Scattering Beamline 6-ID-B,C is the primary beamline on...

  9. Background Material Important Questions about Magnetism

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Background Material Important Questions about Magnetism: 1) What is Magnetism?Magnetism is a force or repulsion due to charge is called the electric force. But what about magnetism, is there a fundamental property of some matter that makes things magnetic? The answer is: "sort of." Electric current

  10. Magnetic Bottles on Riemann Surfaces

    E-Print Network [OSTI]

    Gavriel Segre

    2011-01-17T23:59:59.000Z

    Yves Colin de Verdiere's quantization formalism of magnetic bottles on Riemann surfaces of non null genus is shown to be affected, owing to the Homotopy Superselection Rule, by the phenomenon of the existence of multiple inequivalent quantizations mathematically analogous to the phenomenon of the existence of multiple inequivalent prequantizations of a multiply-connected symplectic manifold in the framework of Souriau-Kostant's Geometric Quantization.

  11. Magnetic Coordinates for Systems with Imperfect Magnetic Surfaces

    E-Print Network [OSTI]

    Dewar, Robert L.

    Magnetic Coordinates for Systems with Imperfect Magnetic Surfaces R. L. Dewar and S. R. Hudson & Engineering, The Australian National University, Canberra, A.C.T. 0200, Australia e-mail: robert-orbits, and the surfaces are formed from a continuous one-parameter family of such orbits. Magnetic field-line flow

  12. Journal of Magnetism and Magnetic Materials ] (

    E-Print Network [OSTI]

    McHenry, Michael E.

    magnetic properties were measured with a vibrating sample magnetometer. The mass-specific power loss.40.Rs Keywords: Nanocrystalline alloys; Amorphous alloys; Field annealing; Power loss; Soft magnets the hysteretic power loss while maintaining high-temperature operability [4]. Other goals have included studies

  13. Materials Characterization Capabilities at the HTML: Surface...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    density analysis of forming samples using advanced characterization techniques Materials Characterization Capabilities at the HTML: SurfaceSub-surface dislocation density...

  14. Electrically Controllable Surface Magnetism on the Surface of Topological Insulators Jia-Ji Zhu,1

    E-Print Network [OSTI]

    Electrically Controllable Surface Magnetism on the Surface of Topological Insulators Jia-Ji Zhu,1 impurities on the surface of three- dimensional topological insulators, mediated by the helical Dirac named topolo- gical insulator (TI) in a number of materials, such as a two-dimensional (2D) HgTe quantum

  15. Journal of Magnetism and Magnetic Materials ] (

    E-Print Network [OSTI]

    Schumann, Rolf

    width of internal field fluctuations. For the ``normal'' TR of the metallic magnets SmCo5; Sm2Co17 of the parameters for SmCo5 and barium ferrite. Susceptibility measurements with small alternating fields, carried out at different points of the TR curve, as well as repeating TR-experiments at SmCo5 demonstrate

  16. Writing magnetic patterns with surface acoustic waves

    SciTech Connect (OSTI)

    Li, Weiyang; Buford, Benjamin; Jander, Albrecht; Dhagat, Pallavi, E-mail: dhagat@eecs.oregonstate.edu [School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, Oregon 97331 (United States)

    2014-05-07T23:59:59.000Z

    A novel patterning technique that creates magnetization patterns in a continuous magnetostrictive film with surface acoustic waves is demonstrated. Patterns of 10??m wide stripes of alternating magnetization and a 3??m dot of reversed magnetization are written using standing and focusing acoustic waves, respectively. The magnetization pattern is size-tunable, erasable, and rewritable by changing the magnetic field and acoustic power. This versatility, along with its solid-state implementation (no moving parts) and electronic control, renders it as a promising technique for application in magnetic recording, magnonic signal processing, magnetic particle manipulation, and spatial magneto-optical modulation.

  17. Static magnetic field concentration and enhancement using magnetic materials with positive permeability

    E-Print Network [OSTI]

    Sun, F

    2013-01-01T23:59:59.000Z

    In this paper a novel compressor for static magnetic fields is proposed based on finite embedded transformation optics. When the DC magnetic field passes through the designed device, the magnetic field can be compressed inside the device. After it passes through the device, one can obtain an enhanced static magnetic field behind the output surface of the device (in a free space region). We can also combine our compressor with some other structures to get a higher static magnetic field enhancement in a free space region. In contrast with other devices based on transformation optics for enhancing static magnetic fields, our device is not a closed structure and thus has some special applications (e.g., for controlling magnetic nano-particles for gene and drag delivery). The designed compressor can be constructed by using currently available materials or DC meta-materials with positive permeability. Numerical simulation verifies good performance of our device.

  18. Magnetism in Non-Traditional Materials

    SciTech Connect (OSTI)

    Menon, Madhu

    2013-09-17T23:59:59.000Z

    We performed a systematic microscopic investigation of two completely dissimilar materials (namely, ZnO and rhombohedral-C{sub 60} polymers) exhibiting ferromagnetism in the presence of defects, and showed that this new phenomena has a common origin and the mechanism responsible can be used as a powerful tool for inducing and tailoring magnetic features in systems which are not magnetic otherwise. Based on our findings we proposed a general recipe for developing ferromagnetism in new materials of great technological interest. Our results support the role of complimentary pairs of defects in inducing magnetism in otherwise non-magnetic materials belonging to two widely differing classes with no apparent correlation between them. In both classes, ferromagnetism is found to be enhanced when the two kinds of defects form structures (pathways) of alternating effective donor and acceptor crystal sites leading to the development of electron charge and spin density like waves. Using ab initio density functional theory calculations we predicted the existence of a new class of carbon cages formed via hybrid connection between planar graphene sheets and carbon nanotubes. The resulting novel structure has the appearance of ?nano-drum? and offers the exciting prospect of integrating useful device properties of both graphene as well as the nanotube into a single unit with tunable electronic properties. Creation of a hexagonal hole in the graphene portion of this structure results in significant magnetic moments for the edge atoms. The structure appears to be capable of sustaining ferrimagnetic state with the assistance of topological defects. The charge and spin distributions obtained in our calculations for the nano-drums are in striking contrast to those in planar graphene nanoribbons with a central hole. In this case, the central hole appears as the complimentary defect to those of the ribbon edges. Similar situation is found in case of the nano-drum in which the complimentary to the hole defects appear to be the pentagons along the curved surface of the drum. Charge oscillations found in the nano-drum are minimized in the nanoribbons. But more importantly, the hole edge atoms in the nano-drums retain significant magnetic moments; almost twice those of the corresponding ones in hydrogenated graphene nanoribbons (H-GNRs). These results suggest that the topological defects in the nano-drums may act like blocks to keep magnetic moments from ?leaking? out from the hole defects. This may have significant implications for the the use of nano-drums in magnetic storage technology where the ratio, magnetic-moment/weight, is of paramount importance in any futuristic device applications. One of the basic problems of the DFT/LSDA+U theory is the efficient evaluation of the U-term. With this in mind we proposed an alternative approach for its calculation which is based on the knowledge of the Hartree-Fock wave functions of the system under consideration. As a result, the proposed approach is closer to the basic definition of the DFT/LSDA+U scheme and its hybrid-DFT nature. According to our approach, the U value is obtained in a consistent and ab-initio way using the self-consistently calculated wave functions of the given system at the level of the HF approximation. Our method is applicable for systems which include more than one type of elements with localized d-orbitals. The method has been applied the case of the doped Zn(Co)O systems successfully. Currently, theories based on conventional superexchange or double-exchange interactions cannot explain long range magnetic order at concentrations below percolation threshold in dilute magnetic semiconductors. On the other hand, the codoping induced magnetism, which can justify magnetic interactions below percolation threshold, has eluded explanation. With this in mind, we proposed that defect-induced magnetism in codoped non-magnetic materials can be viewed within a molecular generalization of the atomic double-exchange and superexchange interactions applied to an arbitrary bipartite lattice host

  19. Self-assembled magnetic surface swimmers.

    SciTech Connect (OSTI)

    Snezhko, A.; Belkin, M.; Aranson, I. S.; Kwok, W.-K.; Materials Science Division; Illinois Inst. of Tech.

    2009-03-20T23:59:59.000Z

    We report studies of novel self-assembled magnetic surface swimmers (magnetic snakes) formed from a dispersion of magnetic microparticles at a liquid-air interface and energized by an alternating magnetic field. We show that under certain conditions the snakes spontaneously break the symmetry of surface flows and turn into self-propelled objects. Parameters of the driving magnetic field tune the propulsion velocity of these snakelike swimmers. We find that the symmetry of the surface flows can also be broken in a controlled fashion by attaching a large bead to a magnetic snake (bead-snake hybrid), transforming it into a self-locomoting entity. The observed phenomena have been successfully described by a phenomenological model based on the amplitude equation for surface waves coupled to a large-scale hydrodynamic mean flow equation.

  20. Thermal Casimir Force between Magnetic Materials

    E-Print Network [OSTI]

    G. L. Klimchitskaya; B. Geyer; V. M. Mostepanenko

    2009-11-21T23:59:59.000Z

    We investigate the Casimir pressure between two parallel plates made of magnetic materials at nonzero temperature. It is shown that for real magnetodielectric materials only the magnetic properties of ferromagnets can influence the Casimir pressure. This influence is accomplished through the contribution of the zero-frequency term of the Lifshitz formula. The possibility of the Casimir repulsion through the vacuum gap is analyzed depending on the model used for the description of the dielectric properties of the metal plates.

  1. Journal of Magnetism and Magnetic Materials 252 (2002) 159161 Magnetically induced alignment of FNS

    E-Print Network [OSTI]

    Reznikov, Yuri

    Journal of Magnetism and Magnetic Materials 252 (2002) 159­161 Magnetically induced alignment the observation of magnetically controlled anchoring of ferro-nematic suspensions. We found that application of a weak magnetic field to a cell with the ferro-suspension induces an easy orientation axis with weak

  2. Magnetic Material for PM Motors

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    *In situ surface passivation approach reduced oxygen content by 60% *High level of control for up-scaled batch fluorination process reduced air oxidation rate by 70% over...

  3. Surface Magnetization of Aperiodic Ising Quantum Chains

    E-Print Network [OSTI]

    L. Turban; B. Berche

    1997-09-11T23:59:59.000Z

    We study the surface magnetization of aperiodic Ising quantum chains. Using fermion techniques, exact results are obtained in the critical region for quasiperiodic sequences generated through an irrational number as well as for the automatic binary Thue-Morse sequence and its generalizations modulo p. The surface magnetization exponent keeps its Ising value, beta_s=1/2, for all the sequences studied. The critical amplitude of the surface magnetization depends on the strength of the modulation and also on the starting point of the chain along the aperiodic sequence.

  4. Magnetic spectroscopy and microscopy of functional materials

    SciTech Connect (OSTI)

    Jenkins, C.A.

    2011-01-28T23:59:59.000Z

    Heusler intermetallics Mn{sub 2}Y Ga and X{sub 2}MnGa (X; Y =Fe, Co, Ni) undergo tetragonal magnetostructural transitions that can result in half metallicity, magnetic shape memory, or the magnetocaloric effect. Understanding the magnetism and magnetic behavior in functional materials is often the most direct route to being able to optimize current materials for todays applications and to design novel ones for tomorrow. Synchrotron soft x-ray magnetic spectromicroscopy techniques are well suited to explore the the competing effects from the magnetization and the lattice parameters in these materials as they provide detailed element-, valence-, and site-specifc information on the coupling of crystallographic ordering and electronic structure as well as external parameters like temperature and pressure on the bonding and exchange. Fundamental work preparing the model systems of spintronic, multiferroic, and energy-related compositions is presented for context. The methodology of synchrotron spectroscopy is presented and applied to not only magnetic characterization but also of developing a systematic screening method for future examples of materials exhibiting any of the above effects. The chapter progression is as follows: an introduction to the concepts and materials under consideration (Chapter 1); an overview of sample preparation techniques and results, and the kinds of characterization methods employed (Chapter 2); spectro- and microscopic explorations of X{sub 2}MnGa/Ge (Chapter 3); spectroscopic investigations of the composition series Mn{sub 2}Y Ga to the logical Mn{sub 3}Ga endpoint (Chapter 4); and a summary and overview of upcoming work (Chapter 5). Appendices include the results of a Think Tank for the Graduate School of Excellence MAINZ (Appendix A) and details of an imaging project now in progress on magnetic reversal and domain wall observation in the classical Heusler material Co{sub 2}FeSi (Appendix B).

  5. Magnetization and magnetostriction in highly magnetostrictive materials

    SciTech Connect (OSTI)

    Thoelke, J.B.

    1993-05-26T23:59:59.000Z

    The majority of this research has been in developing a model to describe the magnetostrictive properties of Terfenol-D, Tb{sub 1{minus}x}Dy{sub x}Fe{sub y} (x = 0.7-0.75 and y = 1.8--2.0), a rare earth-iron alloy which displays much promise for use in device applications. In the first chapter an introduction is given to the phenomena of magnetization and magnetostriction. The magnetic processes responsible for the observed magnetic properties of materials are explained. An overview is presented of the magnetic properties of rare earths, and more specifically the magnetic properties of Terfenol-D. In the second chapter, experimental results are presented on three composition of Tb{sub 1{minus}x}Dy{sub x}Fe{sub y} with x = 0.7, y= 1.9, 1.95, and x= 0.73, y= 1.95. The data were taken for various levels of prestress to show the effects of composition and microstructure on the magnetic and magnetostrictive properties of Terfenol-D. In the third chapter, a theoretical model is developed based on the rotation of magnetic domains. The model is used to explain the magnetic and magnetostrictive properties of Terfenol-D, including the observed negative strictions and large change in strain. The fourth chapter goes on to examine the magnetic properties of Terfenol-D along different crystallographic orientations. In the fifth chapter initial data are presented on the time dependence of magnetization in nickel.

  6. Magnetic mesoporous materials for removal of environmental wastes

    SciTech Connect (OSTI)

    Kim, Byoung Chan; Lee, Jinwoo; Um, Wooyong; Kim, Jaeyun; Joo, Jin; Lee, Jin Hyung; Kwak, Ja Hun; Kim, Jae Hyun; Lee, Changha; Lee, Hongshin; Addleman, Raymond S.; Hyeon, Taeghwan; Gu, Man Bock; Kim, Jungbae

    2011-09-15T23:59:59.000Z

    We have synthesized two different magnetic mesoporous materials that can be easily separated from aqueous solutions by applying a magnetic field. Synthesized magnetic mesoporous materials, Mag-SBA-15 (magnetic ordered mesoporous silica) and Mag-OMC (magnetic ordered mesoporous carbon), have a high loading capacity of contaminants due to high surface area of the supports and high magnetic activity due to the embedded iron oxide particles. Application of surface-modified Mag-SBA-15 was investigated for the collection of mercury from water. The mercury adsorption using Mag-SBA-15 was rapid during the initial contact time and reached a steady-state condition, with an uptake of approximately 97% after 7 hours. Application of Mag-OMC for collection of organics from water, using fluorescein as an easily trackable model analyte, was explored. The fluorescein was absorbed into Mag-OMC within minutes and the fluorescent intensity of solution was completely disappeared after an hour. In another application, Mag-SBA-15 was used as a host of tyrosinase, and employed as recyclable catalytic scaffolds for tyrosinase-catalyzed biodegradation of catechol. Tyrosinase aggregates in Mag-SBA-15, prepared in a two step process of tyrosinase adsorption and crosslinking, could be used repeatedly for catechol degradation with no serious loss of enzyme activity. Considering these results of cleaning up water from toxic inorganic, organic and biochemical contaminants, magnetic mesoporous materials have a great potential to be employed for the removal of environmental contaminants and potentially for the application in large-scale wastewater treatment plants.

  7. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLandLarge Magnetization at

  8. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLandLarge Magnetization

  9. advanced magnetic materials: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to the selection of materials for nano-photonic devices. Key words: Plasmonic electronic materials Peale, Robert E. 294 Modelling the Induced Magnetic Signature of Naval Vessels...

  10. Ames Laboratory scientists create cheaper magnetic material for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ames Laboratory scientists create cheaper magnetic material for cars, wind turbines Contacts: For release: April 23, 2015 Karl A. Gschneidner, Division of Materials Sciences and...

  11. XPS Analysis of Nanostructured Materials and Biological Surfaces...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Analysis of Nanostructured Materials and Biological Surfaces. XPS Analysis of Nanostructured Materials and Biological Surfaces. Abstract: This paper examines the types of...

  12. The Surface Tension of Magnetized Quark Matter

    E-Print Network [OSTI]

    A. F. Garcia; M. B. Pinto

    2013-06-13T23:59:59.000Z

    The surface tension of quark matter plays a crucial role for the possibility of quark matter nucleation during the formation of compact stellar objects and also for the existence of a mixed phase within hybrid stars. However, despite its importance, this quantity does not have a well established numerical value. Some early estimates have predicted that, at zero temperature, the value falls within the wide range $\\gamma_0\\approx10-300{\\rm\\ MeV/fm^2}$ but, very recently, different model applications have reduced these numerical values to fall within the range $\\gamma_0\\approx5-30{\\rm\\ MeV/fm^2}$ which would favor the phase conversion process as well as the appearance of a mixed phase in hybrid stars. In magnetars one should also account for the presence of very high magnetic fields which may reach up to about $ eB\\approx 3-30\\, m_\\pi^2$ ($B \\approx 10^{19}-10^{20} \\,G$) at the core of the star so that it may also be important to analyze how the presence of a magnetic field affects the surface tension. With this aim we consider magnetized two flavor quark matter, described by the Nambu--Jona-Lasinio model. We show that although the surface tension oscillates around its B=0 value, when $0 surface tension value drops by about 30% while for $eB \\gtrsim 10\\, m_\\pi^2$ it quickly raises with the field intensity so that the phase conversion and the presence of a mixed phase should be suppressed if extremely high fields are present. We also investigate how thermal effects influence the surface tension for magnetized quark matter.

  13. SURFACE ORBITAL MAGNETISM Herv'e KUNZ \\Lambda

    E-Print Network [OSTI]

    SURFACE ORBITAL MAGNETISM Herv'e KUNZ \\Lambda Institut de Physique Th'eorique Ecole Polytechnique F, submitted to a magnetic field. Applying these results to orbital magnetism, we find that at high temperatures or weak magnetic fields the surface magnetisation is always paramag­ netic, but oscillations

  14. Magnetic spectroscopy and microscopy of functional materials

    E-Print Network [OSTI]

    Jenkins, C.A.

    2012-01-01T23:59:59.000Z

    transitions for magnetic refrigeration. Appl Phys Lett, 97(these e?ects in magnetic refrigeration and actuation makesheat ?ow with the goal of magnetic refrigeration (adiabatic

  15. REACT: Alternatives to Critical Materials in Magnets

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    REACT Project: The 14 projects that comprise ARPA-E’s REACT Project, short for “Rare Earth Alternatives in Critical Technologies”, are developing cost-effective alternatives to rare earths, the naturally occurring minerals with unique magnetic properties that are used in electric vehicle (EV) motors and wind generators. The REACT projects will identify low-cost and abundant replacement materials for rare earths while encouraging existing technologies to use them more efficiently. These alternatives would facilitate the widespread use of EVs and wind power, drastically reducing the amount of greenhouse gases released into the atmosphere.

  16. A study of magnetically annealed ferromagnetic materials

    E-Print Network [OSTI]

    Ramos, Domingo

    1961-01-01T23:59:59.000Z

    OF SCIENCE August 1961 Major Subject: Electrical Engineering A STUDY OF MAGNETICALLY ANNEALED FERROMAGNETIC MATERIALS A Thesis By 0 ca o o W C DOMINGO RAMOS App ved as to style and content by: r Ct- Chairman of Co ittee Head of Department... coeffrcients ranged from 41. 8 to 75. 8 oersted-microseconds. The Br/Bs ratio for the specimens which gave the highest response vol- tages varied from 0. 66 to 0. 88 and the coercive force ranged from 0. 850 to 1. 410 oersteds. The squareness ratio...

  17. Surface Magnetic Flux Maintenance In Quiet Sun

    E-Print Network [OSTI]

    Y. Iida

    2012-12-27T23:59:59.000Z

    We investigate surface processes of magnetic patches, namely merging, splitting, emergence, and cancellation, by using an auto-detection technique. We find that merging and splitting are locally predominant in the surface level, while the frequencies of the other two are less by one or two orders of magnitude. The frequency dependences on flux con- tent of surface processes are further investigated. Based on these observations, we discuss a possible whole picture of the maintenance. Our conclusion is that the photospheric magnetic field structure, especially its power-law nature, is maintained by the processes locally in the surface not by the interactions between different altitudes. We suggest a scenario of the flux maintenance as follows: The splitting and merging play a crucial role for the generation of the power-law distribution, not the emergence nor cancellation do. This power-law distribution results in another power-law one of the cancellation with an idea of the random convective transport. The cancellation and emergence have a common value for the power-law indices in their frequency distributions, which may suggest a "recycle of fluxes by submergence and re-emergence".

  18. Magnetic filtration process, magnetic filtering material, and methods of forming magnetic filtering material

    DOE Patents [OSTI]

    Taboada-Serrano, Patricia; Tsouris, Constantino; Contescu, Cristian I; McFarlane, Joanna

    2013-10-08T23:59:59.000Z

    The present invention provides magnetically responsive activated carbon, and a method of forming magnetically responsive activated carbon. The method of forming magnetically responsive activated carbon typically includes providing activated carbon in a solution containing ions of ferrite forming elements, wherein at least one of the ferrite forming elements has an oxidation state of +3 and at least a second of the ferrite forming elements has an oxidation state of +2, and increasing pH of the solution to precipitate particles of ferrite that bond to the activated carbon, wherein the activated carbon having the ferrite particles bonded thereto have a positive magnetic susceptibility. The present invention also provides a method of filtering waste water using magnetic activated carbon.

  19. Journal of Magnetism and Magnetic Materials 281 (2004) 272275 Effects of high magnetic field annealing on texture and

    E-Print Network [OSTI]

    Garmestani, Hamid

    Journal of Magnetism and Magnetic Materials 281 (2004) 272­275 Effects of high magnetic field annealing on texture and magnetic properties of FePd D.S. Lia, *, H. Garmestania , Shi-shen Yanb , M China c National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive

  20. Journal of Magnetism and Magnetic Materials 286 (2005) 324328 Light-free magnetic resonance force microscopy for studies of

    E-Print Network [OSTI]

    Journal of Magnetism and Magnetic Materials 286 (2005) 324­328 Light-free magnetic resonance force for Physical Sciences, College Park, MD, USA Available online 4 November 2004 Abstract Magnetic resonance force microscopy is a scanned probe technique capable of three-dimensional magnetic resonance imaging. Its

  1. Ferrofluid surface and volume flows in uniform rotating magnetic fields

    E-Print Network [OSTI]

    Elborai, Shihab M. (Shihab Mahmoud), 1977-

    2006-01-01T23:59:59.000Z

    Ferrofluid surface and volume effects in uniform dc and rotating magnetic fields are studied. Theory and corroborating measurements are presented for meniscus shapes and resulting surface driven flows, spin-up flows, and ...

  2. Magnetic spectroscopy and microscopy of functional materials

    E-Print Network [OSTI]

    Jenkins, C.A.

    2012-01-01T23:59:59.000Z

    in the classical Heusler material Co 2 FeSi (Appendix B).plated self-assembly. Nature Materials, 3:823–828, 2004.1 Concepts Functional materials are those with an industrial

  3. Surface-Based Analysis of Functional Magnetic Resonance Imaging Data

    E-Print Network [OSTI]

    Thompson, Paul

    Surface-Based Analysis of Functional Magnetic Resonance Imaging Data Theo G.M. van Erp1, Vikas Y School of Medicine, Los Angeles, CA 90095, USA Abstract. Surface-based visualization, atlases the integration of surface-based tech- niques with functional imaging data, combining surface-based nonlinear

  4. Magnetic refrigeration apparatus with belt of ferro or paramagnetic material

    DOE Patents [OSTI]

    Barclay, John A. (Madison, WI); Stewart, Walter F. (Marshall, WI); Henke, Michael D. (Los Alamos, NM); Kalash, Kenneth E. (Los Alamos, NM)

    1987-01-01T23:59:59.000Z

    A magnetic refrigerator operating in the 12 to 77K range utilizes a belt which carries ferromagnetic or paramagnetic material and which is disposed in a loop which passes through the center of a solenoidal magnet to achieve cooling. The magnetic material carried by the belt, which can be blocks in frames of a linked belt, can be a mixture of substances with different Curie temperatures arranged such that the Curie temperatures progressively increase from one edge of the belt to the other. This magnetic refrigerator can be used to cool and liquefy hydrogen or other fluids.

  5. Magnetic refrigeration apparatus with belt of ferro or paramagnetic material

    DOE Patents [OSTI]

    Barclay, J.A.; Stewart, W.F.; Henke, M.D.; Kalash, K.E.

    1986-04-03T23:59:59.000Z

    A magnetic refrigerator operating in the 12 to 77 K range utilizes a belt which carries ferromagnetic or paramagnetic material and which is disposed in a loop which passes through the center of a solenoidal magnet to achieve cooling. The magnetic material carried by the belt, which can be blocks in frames of a linked belt, can be a mixture of substances with different Curie temperatures arranged such that the Curie temperatures progressively increase from one edge of the belt to the other. This magnetic refrigerator can be used to cool and liquefy hydrogen or other fluids.

  6. Local geometrical properties of magnetic configurations with nested equilibrium magnetic surfaces

    SciTech Connect (OSTI)

    Skovoroda, A. A. [Russian Research Centre Kurchatov Institute, Nuclear Fusion Institute (Russian Federation)

    2009-04-15T23:59:59.000Z

    The complete set of universal local relationships between geometrical (the curvature and torsion of the force lines of the magnetic field and the field complementary to it) and magnetic (|B|, |{nabla}{Phi}|, b {center_dot} ({nabla} x b), and the local shear s) quantities in currentless magnetic configurations comprising a system of equilibrium nested magnetic surfaces, including those with several magnetic axes, is derived. Possible applications of these relationships are discussed.

  7. Exploring nanoscale magnetism in advanced materials with polarized X-rays

    E-Print Network [OSTI]

    Fischer, Peter

    2012-01-01T23:59:59.000Z

    Stoehr and H.C. Siegmann, „Magnetism”, Springer (2006) [93]Exploring nanoscale magnetism in advanced materials withABSTRACT Nanoscale magnetism is of paramount scientific

  8. Evaluation of Magnetic Materials for Very High Frequency Power Applications

    E-Print Network [OSTI]

    Han, Yehui

    This paper investigates the loss characteristics of RF magnetic materials for power conversion applications in the 10 to 100 MHz range. A measurement method is proposed that provides a direct measurement of an inductor ...

  9. Electromagnetic valve for controlling the flow of molten, magnetic material

    DOE Patents [OSTI]

    Richter, T.

    1998-06-16T23:59:59.000Z

    An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell. 5 figs.

  10. TANK FARM INTERIM SURFACE BARRIER MATERIALS AND RUNOFF ALTERNATIVES STUDY

    SciTech Connect (OSTI)

    HOLM MJ

    2009-06-25T23:59:59.000Z

    This report identifies candidate materials and concepts for interim surface barriers in the single-shell tank farms. An analysis of these materials for application to the TY tank farm is also provided.

  11. Complex curvilinear surfaces in composite materials

    E-Print Network [OSTI]

    Liao, Nancy Han, 1975-

    2001-01-01T23:59:59.000Z

    The thesis will propose a method of architectural design that applies the use of continuous and curvilinear surfaces. It will explore a method of engaging the continuous surface as an expression and response to t he dynamic ...

  12. Digital lock-in detection of site-specific magnetism in magnetic materials

    DOE Patents [OSTI]

    Haskel, Daniel (Naperville, IL); Lang, Jonathan C. (Naperville, IL); Srajer, George (Oak Park, IL)

    2008-07-22T23:59:59.000Z

    The polarization and diffraction characteristics of x-rays incident upon a magnetic material are manipulated to provide a desired magnetic sensitivity in the material. The contrast in diffracted intensity of opposite helicities of circularly polarized x-rays is measured to permit separation of magnetic signals by element type and by atomic environment. This allows for the direct probing of magnetic signals from elements of the same species in nonequivalent atomic environments to better understand the behavior and characteristics of permanent magnetic materials. By using known crystallographic information together with manipulation of the polarization of x-rays having energies tuned near element-specific electronic excitations and by detecting and comparing the incident and diffracted photons at the same frequency, more accurate magnetic measurements can be made over shorter observation periods.

  13. Surface electromagnetic wave equations in a warm magnetized quantum plasma

    SciTech Connect (OSTI)

    Li, Chunhua; Yang, Weihong [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Wu, Zhengwei, E-mail: wuzw@ustc.edu.cn [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Center of Low Temperature Plasma Application, Yunnan Aerospace Industry Company, Kunming, 650229 Yunnan (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

    2014-07-15T23:59:59.000Z

    Based on the single-fluid plasma model, a theoretical investigation of surface electromagnetic waves in a warm quantum magnetized inhomogeneous plasma is presented. The surface electromagnetic waves are assumed to propagate on the plane between a vacuum and a warm quantum magnetized plasma. The quantum magnetohydrodynamic model includes quantum diffraction effect (Bohm potential), and quantum statistical pressure is used to derive the new dispersion relation of surface electromagnetic waves. And the general dispersion relation is analyzed in some special cases of interest. It is shown that surface plasma oscillations can be propagated due to quantum effects, and the propagation velocity is enhanced. Furthermore, the external magnetic field has a significant effect on surface wave's dispersion equation. Our work should be of a useful tool for investigating the physical characteristic of surface waves and physical properties of the bounded quantum plasmas.

  14. Magnetic levitation of metamaterial bodies enhanced with magnetostatic surface resonances

    E-Print Network [OSTI]

    Urzhumov, Yaroslav; Bingham, Chris; Padilla, Willie; Smith, David R

    2011-01-01T23:59:59.000Z

    We propose that macroscopic objects built from negative-permeability metamaterials may experience resonantly enhanced magnetic force in low-frequency magnetic fields. Resonant enhancement of the time-averaged force originates from magnetostatic surface resonances (MSR) which are analogous to the electrostatic resonances of negative-permittivity particles, well known as surface plasmon resonances in optics. We generalize the classical problem of MSR of a homogeneous object to include anisotropic metamaterials, and consider the most extreme case of anisotropy where the permeability is negative in one direction but positive in the others. It is shown that deeply subwavelength objects made of such indefinite (hyperbolic) media exhibit a pronounced magnetic dipole resonance that couples strongly to uniform or weakly inhomogeneous magnetic field and provides strong enhancement of the magnetic force, enabling applications such as enhanced magnetic levitation.

  15. Magnetic Wall Climbing Robot for Thin Surfaces with Specific Obstacles

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Magnetic Wall Climbing Robot for Thin Surfaces with Specific Obstacles W. Fischer¹, F. Tâche high magnetic forces The main optimization criterion for this robot was to design it as light@ethz.ch Summary. This paper describes a novel solution to a mobile climbing robot on mag- netic wheels, designed

  16. Magnetic Filtration Process, Magnetic Filtering Material, and Method of

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9November 6, InaprilU . SMagellanForming Magnetic

  17. Surface Magnetization and Critical Behavior of Aperiodic Ising Quantum Chains

    E-Print Network [OSTI]

    L. Turban; F. Igloi; B. Berche

    1997-09-05T23:59:59.000Z

    We consider semi-infinite two-dimensional layered Ising models in the extreme anisotropic limit with an aperiodic modulation of the couplings. Using substitution rules to generate the aperiodic sequences, we derive functional equations for the surface magnetization. These equations are solved by iteration and the surface magnetic exponent can be determined exactly. The method is applied to three specific aperiodic sequences, which represent different types of perturbation, according to a relevance-irrelevance criterion. On the Thue-Morse lattice, for which the modulation is an irrelevant perturbation, the surface magnetization vanishes with a square root singularity, like in the homogeneous lattice. For the period-doubling sequence, the perturbation is marginal and the surface magnetic exponent varies continuously with the modulation amplitude. Finally, the Rudin-Shapiro sequence, which corresponds to the relevant case, displays an anomalous surface critical behavior which is analyzed via scaling considerations: Depending on the value of the modulation, the surface magnetization either vanishes with an essential singularity or remains finite at the bulk critical point, i.e., the surface phase transition is of first order.

  18. An in situ accelerator-based diagnostic for plasma-material interactions science on magnetic fusion devices

    SciTech Connect (OSTI)

    Hartwig, Zachary S.; Barnard, Harold S.; Lanza, Richard C.; Sorbom, Brandon N.; Stahle, Peter W.; Whyte, Dennis G. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge Massachusetts 02139 (United States)] [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge Massachusetts 02139 (United States)

    2013-12-15T23:59:59.000Z

    This paper presents a novel particle accelerator-based diagnostic that nondestructively measures the evolution of material surface compositions inside magnetic fusion devices. The diagnostic's purpose is to contribute to an integrated understanding of plasma-material interactions in magnetic fusion, which is severely hindered by a dearth of in situ material surface diagnosis. The diagnostic aims to remotely generate isotopic concentration maps on a plasma shot-to-shot timescale that cover a large fraction of the plasma-facing surface inside of a magnetic fusion device without the need for vacuum breaks or physical access to the material surfaces. Our instrument uses a compact (?1 m), high-current (?1 milliamp) radio-frequency quadrupole accelerator to inject 0.9 MeV deuterons into the Alcator C-Mod tokamak at MIT. We control the tokamak magnetic fields – in between plasma shots – to steer the deuterons to material surfaces where the deuterons cause high-Q nuclear reactions with low-Z isotopes ?5 ?m into the material. The induced neutrons and gamma rays are measured with scintillation detectors; energy spectra analysis provides quantitative reconstruction of surface compositions. An overview of the diagnostic technique, known as accelerator-based in situ materials surveillance (AIMS), and the first AIMS diagnostic on the Alcator C-Mod tokamak is given. Experimental validation is shown to demonstrate that an optimized deuteron beam is injected into the tokamak, that low-Z isotopes such as deuterium and boron can be quantified on the material surfaces, and that magnetic steering provides access to different measurement locations. The first AIMS analysis, which measures the relative change in deuterium at a single surface location at the end of the Alcator C-Mod FY2012 plasma campaign, is also presented.

  19. Magnetism of individual atoms adsorbed on surfaces Harald Brune a,*, Pietro Gambardella b

    E-Print Network [OSTI]

    Brune, Harald

    Magnetism of individual atoms adsorbed on surfaces Harald Brune a,*, Pietro Gambardella b history: Available online 10 February 2009 Keywords: Magnetic impurities Magnetic anisotropy Spin­orbit coupling Dilute magnetic semiconductors Spin excitation spectroscopy Spin-polarized transport Quantized

  20. Energy and material efficient non-circular bore Bitter magnets

    E-Print Network [OSTI]

    Akhmeteli, A

    2015-01-01T23:59:59.000Z

    There exist a number of experiments/applications where the second dimension of the bore of Bitter magnets is not fully utilized. Using an analytical solution for elliptical bore coils, we show that reducing one of the dimensions of the bore can lead to considerable decrease in consumed power and/or coil material.

  1. Engineered materials for all-optical helicity-dependent magnetic switching

    E-Print Network [OSTI]

    Fainman, Yeshaiahu

    Engineered materials for all-optical helicity-dependent magnetic switching S. Mangin1,2 *, M we explore the optical manipulation of the magnetization in engineered magnetic materials. We of engineered magnetic materials and devices. We demonstrate that AO-HDS can be observed not only in selected RE

  2. Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials and organisms

    SciTech Connect (OSTI)

    Goodson, Boyd M.

    1999-12-01T23:59:59.000Z

    Conventional nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) are fundamentally challenged by the insensitivity that stems from the ordinarily low spin polarization achievable in even the strongest NMR magnets. However, by transferring angular momentum from laser light to electronic and nuclear spins, optical pumping methods can increase the nuclear spin polarization of noble gases by several orders of magnitude, thereby greatly enhancing their NMR sensitivity. This dissertation is primarily concerned with the principles and practice of optically pumped nuclear magnetic resonance (OPNMR). The enormous sensitivity enhancement afforded by optical pumping noble gases can be exploited to permit a variety of novel NMR experiments across many disciplines. Many such experiments are reviewed, including the void-space imaging of organisms and materials, NMR and MRI of living tissues, probing structure and dynamics of molecules in solution and on surfaces, and zero-field NMR and MRI.

  3. Magnetic Fields above the Surface of aSuperconductor with Internal Magnetism

    SciTech Connect (OSTI)

    Bluhm, Hendrik; /Stanford U., Phys. Dept. /SLAC, SSRl

    2007-06-26T23:59:59.000Z

    The author presents a method for calculating the magnetic fields near a planar surface of a superconductor with a given intrinsic magnetization in the London limit. He computes solutions for various magnetic domain boundary configurations and derives relations between the spectral densities of the magnetization and the resulting field in the vacuum half space, which are useful if the magnetization can be considered as a statistical quantity and its features are too small to be resolved individually. The results are useful for analyzing and designing magnetic scanning experiments. Application to existing data from such experiments on Sr{sub 2}RuO{sub 4} show that a domain wall would have been detectable, but the magnetic field of randomly oriented small domains and small defects may have been smaller than the experimental noise level.

  4. Surface Emission Properties of Strongly Magnetic Neutron Stars

    E-Print Network [OSTI]

    Feryal Ozel

    2001-09-18T23:59:59.000Z

    We construct radiative equilibrium models for strongly magnetized (B > 10^13 G) neutron-star atmospheres taking into account magnetic free-free absorption and scattering processes computed for two polarization modes. We include the effects of vacuum polarization in our calculations. We present temperature profiles and the angle-, photon energy-, and polarization-dependent emerging intensity for a range of magnetic field strengths and effective temperatures of the atmospheres. We find that for B neutron star surface, and find that T_c/T_eff ranges between 1.1-1.8. We discuss the implications of our results for various thermally emitting neutron star models.

  5. Lithium-based surfaces controlling fusion plasma behavior at the plasma-material interface

    SciTech Connect (OSTI)

    Allain, Jean Paul; Taylor, Chase N. [School of Nuclear Engineering, Purdue University, 400 Central Avenue, West Lafayette, Indiana 47907 (United States)

    2012-05-15T23:59:59.000Z

    The plasma-material interface and its impact on the performance of magnetically confined thermonuclear fusion plasmas are considered to be one of the key scientific gaps in the realization of nuclear fusion power. At this interface, high particle and heat flux from the fusion plasma can limit the material's lifetime and reliability and therefore hinder operation of the fusion device. Lithium-based surfaces are now being used in major magnetic confinement fusion devices and have observed profound effects on plasma performance including enhanced confinement, suppression and control of edge localized modes (ELM), lower hydrogen recycling and impurity suppression. The critical spatial scale length of deuterium and helium particle interactions in lithium ranges between 5-100 nm depending on the incident particle energies at the edge and magnetic configuration. Lithium-based surfaces also range from liquid state to solid lithium coatings on a variety of substrates (e.g., graphite, stainless steel, refractory metal W/Mo/etc., or porous metal structures). Temperature-dependent effects from lithium-based surfaces as plasma facing components (PFC) include magnetohydrodynamic (MHD) instability issues related to liquid lithium, surface impurity, and deuterium retention issues, and anomalous physical sputtering increase at temperatures above lithium's melting point. The paper discusses the viability of lithium-based surfaces in future burning-plasma environments such as those found in ITER and DEMO-like fusion reactor devices.

  6. Quantifying object and material surface areas in residences

    SciTech Connect (OSTI)

    Hodgson, Alfred T.; Ming, Katherine Y.; Singer, Brett C.

    2005-01-05T23:59:59.000Z

    The dynamic behavior of volatile organic compounds (VOCs) in indoor environments depends, in part, on sorptive interactions between VOCs in the gas phase and material surfaces. Since information on the types and quantities of interior material surfaces is not generally available, this pilot-scale study was conducted in occupied residences to develop and demonstrate a method for quantifying surface areas of objects and materials in rooms. Access to 33 rooms in nine residences consisting of bathrooms, bedroom/offices and common areas was solicited from among research group members living in the East San Francisco Bay Area. A systematic approach was implemented for measuring rooms and objects from 300 cm{sup 2} and larger. The ventilated air volumes of the rooms were estimated and surface area-to-volume ratios were calculated for objects and materials, each segregated into 20 or more categories. Total surface area-to-volume ratios also were determined for each room. The bathrooms had the highest total surface area-to-volume ratios. Bedrooms generally had higher ratios than common areas consisting of kitchens, living/dining rooms and transitional rooms. Total surface area-to-volume ratios for the 12 bedrooms ranged between 2.3 and 4.7 m{sup 2} m{sup -3}. The importance of individual objects and materials with respect to sorption will depend upon the sorption coefficients for the various VOC/materials combinations. When combined, the highly permeable material categories, which may contribute to significant interactions, had a median ratio of about 0.5 m{sup 2} m{sup -3} for all three types of rooms.

  7. NEUTRON STAR ENVELOPES AND THERMAL RADIATION FROM THE MAGNETIC SURFACE

    E-Print Network [OSTI]

    NEUTRON STAR ENVELOPES AND THERMAL RADIATION FROM THE MAGNETIC SURFACE in: C. Kouveliotou, J. van.Petersburg, Russia Abstract. The thermal structure of neutron star envelopes is discussed with emphasis on analytic on the opacities and the thermal structure is further reviewed in view of the application to pulsar cooling

  8. Ultra-low field nuclear magnetic resonance and magnetic resonance imaging to discriminate and identify materials

    DOE Patents [OSTI]

    Kraus, Robert H. (Los Alamos, NM); Matlashov, Andrei N. (Los Alamos, NM); Espy, Michelle A. (Los Alamos, NM); Volegov, Petr L. (Los Alamos, NM)

    2010-03-30T23:59:59.000Z

    An ultra-low magnetic field NMR system can non-invasively examine containers. Database matching techniques can then identify hazardous materials within the containers. Ultra-low field NMR systems are ideal for this purpose because they do not require large powerful magnets and because they can examine materials enclosed in conductive shells such as lead shells. The NMR examination technique can be combined with ultra-low field NMR imaging, where an NMR image is obtained and analyzed to identify target volumes. Spatial sensitivity encoding can also be used to identify target volumes. After the target volumes are identified the NMR measurement technique can be used to identify their contents.

  9. Model for Dynamic Self-Assembled Magnetic Surface Structures

    E-Print Network [OSTI]

    M. Belkin; A. Glatz; A. Snezhko; I. S. Aranson

    2010-02-02T23:59:59.000Z

    We propose a first-principles model for self-assembled magnetic surface structures on the water-air interface reported in earlier experiments \\cite{snezhko2,snezhko4}. The model is based on the Navier-Stokes equation for liquids in shallow water approximation coupled to Newton equations for interacting magnetic particles suspended on the water-air interface. The model reproduces most of the observed phenomenology, including spontaneous formation of magnetic snake-like structures, generation of large-scale vortex flows, complex ferromagnetic-antiferromagnetic ordering of the snake, and self-propulsion of bead-snake hybrids. The model provides valuable insights into self-organization phenomena in a broad range of non-equilibrium magnetic and electrostatic systems with competing interactions.

  10. Apparatus for magnetic separation of paramagnetic and diamagnetic material

    DOE Patents [OSTI]

    Doctor, R.D.

    1986-07-24T23:59:59.000Z

    The present invention relates to methods and apparatus for segregating paramagnetic from diamagnetic particles in particulate material and, in particular, to the open gradient magnetic separation of ash producing components and pyritic sulfur from coal. The apparatus includes a vertical cylinder and a rotatable vertical screw positioned within the cylinder, the screw having a helical blade angled downwardly and outwardly from the axis. Rotation of the vertical screw causes denser particles, which in the case of coal include pyritic sulfur and ash, which are paramagnetic, to migrate to the outside of the screw, and less dense particles, such as the low sulfur organic portion of the coal, which are diamagnetic, to migrate towards the center of the screw. A vibration mechanism attached to the screw causes the screw to vibrate during rotation, agitating and thereby accommodating further segregation of the particles. An open gradient magnetic field is applied circumferentially along the entire length of the screw by a superconducting quadrupole magnet. The open gradient magnetic field further segregates the paramagnetic-particles from the diamagnetic particles. The paramagnetic particles may then be directed from the cylinder into a first storage bin, and the diamagnetic particles, which are suitable for relatively clean combustion, may be directed into a second storage bin. 5 figs.

  11. Apparatus for magnetic separation of paramagnetic and diamagnetic material

    DOE Patents [OSTI]

    Doctor, R.D.

    1988-10-18T23:59:59.000Z

    The present invention relates to methods and apparatus for segregating paramagnetic from diamagnetic particles in particulate material and, in particular, to the open gradient magnetic separation of ash producing components and pyritic sulfur from coal. The apparatus includes a vertical cylinder and a rotatable vertical screw positioned within the cylinder, the screw having a helical blade angled downwardly and outwardly from the axis. Rotation of the vertical screw causes denser particles, which in the case of coal include pyritic sulfur and ash, which are paramagnetic, to migrate to the outside of the screw, and less dense particles, such as the low sulfur organic portion of the coal, which are diamagnetic, to migrate towards the center of the screw. A vibration mechanism attached to the screw causes the screw to vibrate during rotation, agitating and thereby accommodating further segregation of the particles. An open gradient magnetic field is applied circumferentially along the entire length of the screw by a superconducting quadrupole magnet. The open gradient magnetic field further segregates the paramagnetic particles from the diamagnetic particles. The paramagnetic particles may then be directed from the cylinder into a first storage bin, and the diamagnetic particles, which are suitable for relatively clean combustion, may be directed into a second storage bin. 5 figs.

  12. Radiation from condensed surface of magnetic neutron stars

    E-Print Network [OSTI]

    Matthew van Adelsberg; Dong Lai; Alexander Y. Potekhin; Phil Arras

    2005-05-04T23:59:59.000Z

    Recent observations show that the thermal X-ray spectra of many isolated neutron stars are featureless and in some cases (e.g., RX J1856.5-3754) well fit by a blackbody. Such a perfect blackbody spectrum is puzzling since radiative transport through typical neutron star atmospheres causes noticeable deviation from blackbody. Previous studies have shown that in a strong magnetic field, the outermost layer of the neutron star may be in a condensed solid or liquid form because of the greatly enhanced cohesive energy of the condensed matter. The critical temperature of condensation increases with the magnetic field strength, and can be as high as 10^6 K (for Fe surface at B \\sim 10^{13} G or H surface at B \\sim a few times 10^{14} G). Thus the thermal radiation can directly emerge from the degenerate metallic condensed surface, without going through a gaseous atmosphere. Here we calculate the emission properties (spectrum and polarization) of the condensed Fe and H surfaces of magnetic neutron stars in the regimes where such condensation may be possible. For a smooth condensed surface, the overall emission is reduced from the blackbody by less than a factor of 2. The spectrum exhibits modest deviation from blackbody across a wide energy range, and shows mild absorption features associated with the ion cyclotron frequency and the electron plasma frequency in the condensed matter. The roughness of the solid condensate (in the Fe case) tends to decrease the reflectivity of the surface, and make the emission spectrum even closer to blackbody. We discuss the implications of our results for observations of dim, isolated neutron stars and magnetars.

  13. Non-principal surface waves in deformed incompressible materials

    E-Print Network [OSTI]

    Michel Destrade; Melanie Ottenio; Alexey V. Pichugin; Graham A. Rogerson

    2013-04-23T23:59:59.000Z

    The Stroh formalism is applied to the analysis of infinitesimal surface wave propagation in a statically, finitely and homogeneously deformed isotropic half-space. The free surface is assumed to coincide with one of the principal planes of the primary strain, but a propagating surface wave is not restricted to a principal direction. A variant of Taziev's technique [Sov. Phys. Acoust. 35 (1989) 535] is used to obtain an explicit expression of the secular equation for the surface wave speed, which possesses no restrictions on the form of the strain energy function. Albeit powerful, this method does not produce a unique solution and additional checks are necessary. However, a class of materials is presented for which an exact secular equation for the surface wave speed can be formulated. This class includes the well-known Mooney-Rivlin model. The main results are illustrated with several numerical examples.

  14. The magnetic resonance force microscope: A new microscopic probe of magnetic materials

    SciTech Connect (OSTI)

    Hammel, P.C.; Zhang, Z. [Los Alamos National Lab., NM (United States); Midzor, M.; Roukes, M.L. [California Inst. of Tech., Pasadena, CA (United States); Wigen, P.E. [Ohio State Univ., Columbus, OH (United States); Childress, J.R. [Univ. of Florida, Gainesville, FL (United States)

    1997-08-06T23:59:59.000Z

    The magnetic resonance force microscope (MRFM) marries the techniques of magnetic resonance imaging (MRI) and atomic force microscopy (AFM), to produce a three-dimensional imaging instrument with high, potentially atomic-scale, resolution. The principle of the MRFM has been successfully demonstrated in numerous experiments. By virtue of its unique capabilities the MRFM shows promise to make important contributions in fields ranging from three-dimensional materials characterization to bio-molecular structure determination. Here the authors focus on its application to the characterization and study of layered magnetic materials; the ability to illuminate the properties of buried interfaces in such materials is a particularly important goal. While sensitivity and spatial resolution are currently still far from their theoretical limits, they are nonetheless comparable to or superior to that achievable in conventional MRI. Further improvement of the MRFM will involve operation at lower temperature, application of larger field gradients, introduction of advanced mechanical resonators and improved reduction of the spurious coupling when the magnet is on the resonator.

  15. assisted materials surface: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    assisted materials surface First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Polymer assisted synthesis...

  16. Influence of surface segregation on magnetic properties of FePt nanoparticles

    SciTech Connect (OSTI)

    Lv, Hongyan [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States) [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States); Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Lei, Yinkai; Datta, Aditi; Wang, Guofeng [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States)] [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States)

    2013-09-23T23:59:59.000Z

    Surface segregation leads to chemical disordering in magnetic alloy nanostructures and thus could have profound impact upon the magnetic properties of these nanostructures. In this study, we used the first-principles density functional theory calculation method to determine how Pt surface segregation (exchanging interior Pt with surface Fe atoms) would affect the magnetic properties of L1{sub 0} ordered FePt nanoparticles. For both cuboid and cuboctahedral FePt nanoparticles, we predicted that the Pt surface segregation process could cause a decrease in total magnetic moments, a change in (easy and/or hard) magnetization axes, and a reduction in magnetic anisotropy.

  17. Magnetic resonance studies of cement based materials in inhomogeneous magnetic fields

    SciTech Connect (OSTI)

    Boguszynska, Joanna [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, Poznan (Poland); Brown, Marc C.A. [School of Physical Sciences, University of Kent, Canterbury, Kent, CT2 7NR (United Kingdom); McDonald, Peter J. [School of Electronics and Physical Sciences, University of Surrey, Surrey, GU2 7XH (United Kingdom)]. E-mail: p.mcdonald@surrey.ac.uk; Mitchell, Jonathan [School of Electronics and Physical Sciences, University of Surrey, Surrey, GU2 7XH (United Kingdom); Mulheron, Mike [School of Engineering, University of Surrey, Surrey, GU2 7XH (United Kingdom); Tritt-Goc, Jadwiga [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, Poznan (Poland); Verganelakis, Dimitris A. [Department of Chemical Engineering, University of Cambridge, Cambridge, CB2 3RA (United Kingdom)

    2005-10-01T23:59:59.000Z

    Single-sided magnets give hope that Nuclear Magnetic Resonance (NMR) might in future be used for in situ characterisation of hydration and water transport in the surface layers of concrete slabs. Towards that end, a portable NMR-MOUSE (MObile Universal Surface Explorer) has been used to follow the hydration of gypsum based plaster, a Portland cement paste and concrete mortar. The results compare favourably to those obtained using a standard laboratory bench-top spectrometer. Further, stray field imaging (STRAFI) based methods have been used with embedded NMR detector coils to study water transport across a mortar/topping interface. The measured signal amplitudes are found to correlate with varying sample conditions.

  18. Use of High Magnetic Field to Control Microstructural Evolution in Metallic and Magnetic Materials

    SciTech Connect (OSTI)

    Ludtka, G.M.; Mackiewicz- Ludtka, G.; Wilgen, J.B.; Kisner, R.A.

    2010-06-27T23:59:59.000Z

    The Amendment 1, referred to as Phase 2, to the original CRADA NFE-06-00414 added tasks 3 through 7 to the original statement of work that had two main tasks that were successfully accomplished in Phase 1 of this project. In this Phase 2 CRADA extension, extensive research and development activities were conducted using high magnetic field processing effects for the purpose of manipulating microstructure in the SAE 5160 steel to refine grain size isothermally and to develop nanocrystalline spacing pearlite during continuous cooling, and to enhance the formability/forgability of the non-ferrous precipitation hardening magnesium alloy AZ90 by applying a high magnetic field during deformation processing to investigate potential magnetoplasticity in this material. Significant experimental issues (especially non-isothermal conditions evolving upon insertion of an isothermal sample in the high magnetic field) were encountered in the isothermal phase transformation reversal experiments (Task 4) that later were determined to be due to various condensed matter physics phenomenon such as the magnetocaloric (MCE) effect that occurs in the vicinity of a materials Curie temperature. Similarly the experimental deformation rig had components for monitoring deformation/strain (Task 3) that were susceptible to the high magnetic field of the ORNL Thermomagnetic Processing facility 9-T superconducting magnet that caused electronic components to fail or record erroneous (very noisy) signals. Limited experiments on developing nanocrystalline spacing pearlite were not sufficient to elucidate the impact of high magnetic field processing on the final pearlite spacing since significant statistical evaluation of many pearlite colonies would need to be done to be conclusive. Since extensive effort was devoted to resolving issues for Tasks 3 and 7, only results for these focused activities are included in this final CRADA report along with those for Task 7 (described in the Objectives Section of this report).

  19. Method and apparatus for separating materials magnetically. [Patent application; iron pyrite from coal

    DOE Patents [OSTI]

    Hise, E.C. Jr.; Holman, A.S.; Friedlaender, F.J.

    1980-11-06T23:59:59.000Z

    Magnetic and nonmagnetic materials are separated by passing stream thereof past coaxial current-carrying coils which produce a magnetic field wherein intensity varies sharply with distance radially of the axis of the coils.

  20. Selected materials development for the 100 T magnet: Cu-Nb conductors with

    E-Print Network [OSTI]

    Weston, Ken

    Selected materials development for the 100 T magnet: Cu-Nb conductors with nanocomposite components (PBO) based composite for reinforcement Materials R&D for the 100-Tesla Pulsed Magnet Gregory S for this achievement was the long-term and painstaking research and development of high strength materials

  1. Magnetism of Ho and Er Atoms on Close-Packed Metal Surfaces F. Donati,1

    E-Print Network [OSTI]

    Thévenaz, Jacques

    Magnetism of Ho and Er Atoms on Close-Packed Metal Surfaces F. Donati,1 A. Singha,1 S. Stepanow,2 C; published 3 December 2014) We investigated the magnetic properties of individual Ho atoms adsorbed on the (111) surface of Pt, which have been recently claimed to display single ion magnetic behavior

  2. Materials Physics Applications: The National High Magnetic Field...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Pulsed Magnetic Field Laboratory of the NHMFL in the form of a 1.4 GVA inertial storage motor-generator for high field pulsed magnets. In addition to the 60 Tesla Long Pulse Magnet...

  3. Condensed Surfaces of Magnetic Neutron Stars, Thermal Surface Emission, and Particle Acceleration Above Pulsar Polar Caps

    E-Print Network [OSTI]

    Zach Medin; Dong Lai

    2008-01-18T23:59:59.000Z

    For sufficiently strong magnetic fields and/or low temperatures, the neutron star surface may be in a condensed state with little gas or plasma above it. Such surface condensation can significantly affect the thermal emission from isolated neutron stars, and may lead to the formation of a charge-depleted acceleration zone ("vacuum gap") in the magnetosphere above the stellar polar cap. Using the latest results on the cohesive property of magnetic condensed matter, we quantitatively determine the conditions for surface condensation and vacuum gap formation in magnetic neutron stars. We find that condensation can occur if the thermal energy kT of the neutron star surface is less than about 8% of its cohesive energy Q_s, and that a vacuum gap can form if the neutron star's rotation axis and magnetic moment point in opposite directions and kT is less than about 4% of Q_s. Thus, vacuum gap accelerators may exist for some neutron stars. Motivated by this result, we also study the physics of pair cascades in the vacuum gap model for photon emission by accelerating electrons and positrons due to both curvature radiation and resonant/nonresonant inverse Compton scattering. Our calculations of the condition of cascade-induced vacuum breakdown and the related pulsar death line/boundary generalize previous works to the superstrong field regime. We find that inverse Compton scatterings do not produce a sufficient number of high energy photons in the gap and thus do not lead to pair cascades for most neutron star parameters. We discuss the implications of our results for the recent observations of neutron star thermal radiation as well as for the detection/non-detection of radio emission from high-B pulsars and magnetars.

  4. Giant Magnetic Effects Induced in Hybrid Materials | U.S. DOE...

    Office of Science (SC) Website

    Giant Magnetic Effects Induced in Hybrid Materials Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding Opportunities Basic...

  5. Radon-222 progeny surface deposition and resuspension - residential materials

    SciTech Connect (OSTI)

    Leonard, B.E.

    1994-12-31T23:59:59.000Z

    In evaluating the hazards from indoor {sup 222}Rn, it is imperative that the behavior of the four short-lived particulate progeny are fully understood since they are the radioisotopes that deliver most of the radiobiological damage to occupants. One known characteristic of these radon progeny is that they deposit (plate out) onto macroscopic surfaces. Some of these plated-out atoms become resuspended when they disintegrate and decay to the next progeny, in particular, {sup 218}Po. Both of these mechanisms, plateout and resuspension, affect the airborne population of the individual daughters and their impact on the radiation energy delivered to the human respiratory system. There are two specific and separate areas of concern, One is that monitoring {sup 222} Rn levels alone, such as with charcoal canisters, is obviously not sufficient to determine the radiation dose since the daughters are never in absolute equilibrium with {sup 222}Rn. Further, from an internal dose standpoint, the {open_quotes}unattached{close_quotes} fraction (free ions) of the daughters are believed, by virtue of their deeper tissue depositions in the tracheo-bronchial tract, to deliver the greatest dose in the body. Currently, there are virtually no data on the measurements of both plateout rates and resuspension factors for specific individual residential material surfaces. This report presents experimental data of plateout rates in an indoor house for typical indoor materials. Results of measurements of resuspension factors for some of the materials are provided.

  6. Comparison of glass surfaces as a countertop material to existing surfaces

    SciTech Connect (OSTI)

    Turo, Laura A.; Winschell, Abigail E.

    2011-09-01T23:59:59.000Z

    Gleen Glass, a small production glass company that creates countertops, was selected for the Technology Assistance Program through Pacific Northwest National Laboratory. Gleen Glass was seeking material property analysis comparing glass as a countertop material to current surfaces (i.e. marble, granite and engineered stone). With samples provided from Gleen Glass, testing was done on granite, marble, and 3 different glass surfaces ('Journey,' 'Pebble,' and 'Gleen'). Results showed the glass surfaces have a lower density, lower water absorption, and are stronger in compressive and flexural tests as compared to granite and marble. Thermal shock tests showed the glass failed when objects with a high thermal mass are placed directly on them, whereas marble and granite did not fracture under these conditions.

  7. Method of driving liquid flow at or near the free surface using magnetic microparticles

    DOE Patents [OSTI]

    Snezhko, Oleksiy (Woodridge, IL); Aronson, Igor (Darien, IL); Kwok, Wai-Kwong (Evanston, IL); Belkin, Maxim V. (Woodridge, IL)

    2011-10-11T23:59:59.000Z

    The present invention provides a method of driving liquid flow at or near a free surface using self-assembled structures composed of magnetic particles subjected to an external AC magnetic field. A plurality of magnetic particles are supported at or near a free surface of liquid by surface tension or buoyancy force. An AC magnetic field traverses the free surface and dipole-dipole interaction between particles produces in self-assembled snake structures which oscillate at the frequency of the traverse AC magnetic field. The snake structures independently move across the free surface and may merge with other snake structures or break up and coalesce into additional snake structures experiencing independent movement across the liquid surface. During this process, the snake structures produce asymmetric flow vortices across substantially the entirety of the free surface, effectuating liquid flow across the free surface.

  8. Method for producing high surface area chromia materials for catalysis

    SciTech Connect (OSTI)

    Gash, Alexander E. (Brentwood, CA); Satcher, Joe (Patterson, CA); Tillotson, Thomas (Tracy, CA); Hrubesh, Lawrence (Pleasanton, CA); Simpson, Randall (Livermore, CA)

    2007-05-01T23:59:59.000Z

    Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m.sup.2/g and 520 m.sup.2/g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.

  9. Anomalous magnetic behavior in nanocomposite materials of reduced graphene oxide-Ni/NiFe{sub 2}O{sub 4}

    SciTech Connect (OSTI)

    Kollu, Pratap, E-mail: pk419@cam.ac.uk, E-mail: anirmalagrace@vit.ac.in, E-mail: dhirenb@iitb.ac.in [DST-INSPIRE Faculty, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India); Prathapani, Sateesh; Varaprasadarao, Eswara K.; Mallick, Sudhanshu; Bahadur, D., E-mail: pk419@cam.ac.uk, E-mail: anirmalagrace@vit.ac.in, E-mail: dhirenb@iitb.ac.in [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India); Santosh, Chella; Grace, Andrews Nirmala, E-mail: pk419@cam.ac.uk, E-mail: anirmalagrace@vit.ac.in, E-mail: dhirenb@iitb.ac.in [Centre for Nanotechnology Research, VIT University, Vellore 632014 (India)

    2014-08-04T23:59:59.000Z

    Magnetic Reduced Graphene Oxide-Nickel/NiFe{sub 2}O{sub 4} (RGO-Ni/NF) nanocomposite has been synthesized by one pot solvothermal method. Respective phase formations and their purities in the composite are confirmed by High Resolution Transmission Electron Microscope and X Ray Diffraction, respectively. For the RGO-Ni/NF composite material finite-size effects lead to the anomalous magnetic behavior, which is corroborated in temperature and field dependent magnetization curves. Here, we are reporting the behavior of higher magnetization values for Zero Field Cooled condition to that of Field Cooled for the RGO-Ni/NF nanocomposite. Also, the observed negative and positive moments in Hysteresis loops at relatively smaller applied fields (100?Oe and 200?Oe) are explained on the basis of surface spin disorder.

  10. A nuclear magnetic resonance study of hydrogen in battery and chemically prepared material

    SciTech Connect (OSTI)

    Hill, R.J.; Jessel, A.M.

    1987-06-01T23:59:59.000Z

    Solid-state magic-angle-spinning nuclear magnetic resonance studies have been undertaken on positive plate material from lead-acid batteries and on samples of both pure ..cap alpha..-PbO/sub 2/ and pure ..beta..-PbO/sub 2/ prepared by nonelectrochemical methods. Battery positive plate samples contain protons in two different surface and near surface configurations. One of these proton species is associated with mobile, isolated, adsorbed hydroxyl groups, and/or water molecules that can be removed by outgassing. The other proton species is not removed by outgassing; it probably corresponds to water molecules and/of closely spaced hydroxyl groups trapped on internal crystal surfaces. The proton species present in fresh (uncycled) positive plate material are not significantly different in either configuration or abundance from those in extensively cycled samples. Thus, it is unlikely that decline in battery capacity with cycling service is associated with a change in the hydrogen content of PbO/sub 2/.

  11. Magnetic mesoporous material for the sequestration of algae

    DOE Patents [OSTI]

    Trewyn, Brian G.; Kandel, Kapil; Slowing, Igor Ivan; Lee, Show-Ling

    2014-09-09T23:59:59.000Z

    The present invention provides a magnetic mesoporous nanoparticle that includes a mesoporous silicate nanoparticle and iron oxide. The present invention also provides a method of using magnetic mesoporous nanoparticles to sequester microorganisms from a media.

  12. Ion accumulation in an electron plasma confined on magnetic surfaces

    SciTech Connect (OSTI)

    Berkery, John W.; Marksteiner, Quinn R.; Pedersen, Thomas Sunn; Kremer, Jason P. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2007-08-15T23:59:59.000Z

    Accumulation of ions can alter and may destabilize the equilibrium of an electron plasma confined on magnetic surfaces. An analysis of ion sources and ion content in the Columbia Non-neutral Torus (CNT) [T.S. Pedersen, J.P. Kremer, R.G. Lefrancois, Q. Marksteiner, N. Pomphrey, W. Reiersen, F. Dahlgreen, and X. Sarasola, Fusion Sci. Technol. 50, 372 (2006)] is presented. In CNT ions are created preferentially at locations of high electron temperature, near the outer magnetic surfaces. A volumetric integral of n{sub e}{nu}{sub iz} gives an ion creation rate of 2.8x10{sup 11} ions/s. This rate of accumulation would cause neutralization of a plasma with 10{sup 11} electrons in about half a second. This is not observed experimentally, however, because currently in CNT ions are lost through recombination on insulated rods. From a steady-state balance between the calculated ion creation and loss rates, the equilibrium ion density in a 2x10{sup -8} Torr neutral pressure, 7.5x10{sup 11} m{sup -3} electron density plasma in CNT is calculated to be n{sub i}=6.2x10{sup 9} m{sup -3}, or 0.8%. The ion density is experimentally measured through the measurement of the ion saturation current on a large area probe to be about 6.0x10{sup 9} m{sup -3} for these plasmas, which is in good agreement with the predicted value.

  13. High frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials

    DOE Patents [OSTI]

    Sanchez, Robert O.; Gunewardena, Shelton; Masi, James V.

    2005-03-29T23:59:59.000Z

    An electrical component in the form of an inductor or transformer is disclosed which includes one or more coils and a magnetic polymer material located near the coils or supporting the coils to provide an electromagnetic interaction therewith. The magnetic polymer material is preferably a cured magnetic epoxy which includes a mercaptan derivative having a ferromagnetic atom chemically bonded therein. The ferromagnetic atom can be either a transition metal or rare-earth atom.

  14. High frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials

    DOE Patents [OSTI]

    Sanchez, Robert O. (Los Lunas, NM); Gunewardena, Shelton (Walnut, CA); Masi, James V. (Cape Elizabeth, ME)

    2007-11-27T23:59:59.000Z

    An electrical component in the form of an inductor or transformer is disclosed which includes one or more coils and a magnetic polymer material located near the coils or supporting the coils to provide an electromagnetic interaction therewith. The magnetic polymer material is preferably a cured magnetic epoxy which includes a mercaptan derivative having a ferromagnetic atom chemically bonded therein. The ferromagnetic atom can be either a transition metal or rare-earth atom.

  15. Magnetic refrigeration: Materials, design, and applications. (Latest citations from the INSPEC database). Published Search

    SciTech Connect (OSTI)

    NONE

    1995-12-01T23:59:59.000Z

    The bibliography contains citations concerning cryogenics using magnetic refrigerants. Refrigerant properties, magnetic materials, and thermal characteristics are discussed. Magnetic refrigerators are used for helium liquefaction, cooling superconductors, and superfluid helium production. Carnot-cycle refrigerators, reciprocating refrigerators, parasitic refrigerators, Ericsson refrigerators, and Stirling cycle refrigerators are among the types of magnetic refrigerators evaluated. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Magnetic refrigeration: Materials, design, and applications. (Latest citations from the INSPEC database). Published Search

    SciTech Connect (OSTI)

    NONE

    1995-01-01T23:59:59.000Z

    The bibliography contains citations concerning cryogenics using magnetic refrigerants. Refrigerant properties, magnetic materials, and thermal characteristics are discussed. Magnetic refrigerators are used for helium liquefaction, cooling superconductors, and superfluid helium production. Carnot-cycle refrigerators, reciprocating refrigerators, parasitic refrigerators, Ericsson refrigerators, and Stirling cycle refrigerators are among the types of magnetic refrigerators evaluated. (Contains a minimum of 118 citations and includes a subject term index and title list.)

  17. Chemical, electronic, and magnetic structure of LaFeCoSi alloy: Surface and bulk properties

    SciTech Connect (OSTI)

    Lollobrigida, V. [Dipartimento di Scienze, Università Roma Tre, I-00146 Rome (Italy); Dipartimento di Matematica e Fisica, Università Roma Tre, I-00146 Rome (Italy); Basso, V.; Kuepferling, M.; Coïsson, M.; Olivetti, E. S.; Celegato, F. [Istituto Nazionale di Ricerca Metrologica (INRIM), I-10135 Torino (Italy); Borgatti, F. [CNR, Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), I-40129 Bologna (Italy); Torelli, P.; Panaccione, G. [CNR, Istituto Officina dei Materiali (IOM), Lab. TASC, I-34149 Trieste (Italy); Tortora, L. [Laboratorio di Analisi di Superficie, Dipartimento di Matematica e Fisica, Università Roma Tre, I-00146 Rome (Italy); Dipartimento di Ingegneria Meccanica, Università Tor Vergata, I-00133 Rome (Italy); Stefani, G.; Offi, F. [Dipartimento di Scienze, Università Roma Tre, I-00146 Rome (Italy)

    2014-05-28T23:59:59.000Z

    We investigate the chemical, electronic, and magnetic structure of the magnetocaloric LaFeCoSi compound with bulk and surface sensitive techniques. We put in evidence that the surface retains a soft ferromagnetic behavior at temperatures higher than the Curie temperature of the bulk due to the presence of Fe clusters at the surface only. This peculiar magnetic surface effect is attributed to the exchange interaction between the ferromagnetic Fe clusters located at the surface and the bulk magnetocaloric alloy, and it is used here to monitor the magnetic properties of the alloy itself.

  18. Biasing and fast degaussing circuit for magnetic materials

    DOE Patents [OSTI]

    Dress, W.B. Jr.; McNeilly, D.R.

    1983-10-04T23:59:59.000Z

    A dual-function circuit is provided which may be used to both magnetically bias and alternately, quickly degauss a magnetic device. The circuit may be magnetically coupled or directly connected electrically to a magnetic device, such as a magnetostrictive transducer, to magnetically bias the device by applying a dc current and alternately apply a selectively damped ac current to the device to degauss the device. The circuit is of particular value in many systems which use magnetostrictive transducers for ultrasonic transmission in different propagation modes over very short time periods.

  19. Biasing and fast degaussing circuit for magnetic materials

    DOE Patents [OSTI]

    Dress, Jr., William B. (Lenoir City, TN); McNeilly, David R. (Maryville, TN)

    1984-01-01T23:59:59.000Z

    A dual-function circuit is provided which may be used to both magnetically bias and alternately, quickly degauss a magnetic device. The circuit may be magnetically coupled or directly connected electrically to a magnetic device, such as a magnetostrictive transducer, to magnetically bias the device by applying a d.c. current and alternately apply a selectively damped a.c. current to the device to degauss the device. The circuit is of particular value in many systems which use magnetostrictive transducers for ultrasonic transmission in different propagation modes over very short time periods.

  20. Iron-Nickel-Based SuperMagnets: Multiscale Development of L10 Materials for Rare Earth-Free Permanent Magnets

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    REACT Project: Northeastern University will develop bulk quantities of rare-earth-free permanent magnets with an iron-nickel crystal structure for use in the electric motors of renewable power generators and EVs. These materials could offer magnetic properties that are equivalent to today’s best commercial magnets, but with a significant cost reduction and diminished environmental impact. This iron-nickel crystal structure, which is only found naturally in meteorites and developed over billions of years in space, will be artificially synthesized by the Northeastern University team. Its material structure will be replicated with the assistance of alloying elements introduced to help it achieve superior magnetic properties. The ultimate goal of this project is to demonstrate bulk magnetic properties that can be fabricated at the industrial scale.

  1. Fourth annual progress report on special-purpose materials for magnetically confined fusion reactors

    SciTech Connect (OSTI)

    Not Available

    1982-08-01T23:59:59.000Z

    The scope of Special Purpose Materials covers fusion reactor materials problems other than the first-wall and blanket structural materials, which are under the purview of the ADIP, DAFS, and PMI task groups. Components that are considered as special purpose materials include breeding materials, coolants, neutron multipliers, barriers for tritium control, materials for compression and OH coils and waveguides, graphite and SiC, heat-sink materials, ceramics, and materials for high-field (>10-T) superconducting magnets. The Task Group on Special Purpose Materials has limited its concern to crucial and generic materials problems that must be resolved if magnetic-fusion devices are to succeed. Important areas specifically excluded include low-field (8-T) superconductors, fuels for hybrids, and materials for inertial-confinement devices. These areas may be added in the future when funding permits.

  2. Forecasting change of the magnetic field using core surface flows and ensemble Kalman filtering

    E-Print Network [OSTI]

    Forecasting change of the magnetic field using core surface flows and ensemble Kalman filtering C-based observatories. We therefore present a method using Ensemble Kalman Filtering (EnKF) to produce an optimal (2009), Forecasting change of the magnetic field using core surface flows and ensemble Kalman filtering

  3. SURVEY OF HIGH FIELD SUPERCONDUCTING MATERIAL FOR ACCELERATOR MAGNETS

    E-Print Network [OSTI]

    Scanlan, R.

    2010-01-01T23:59:59.000Z

    1. Production status of Superconducto~ s Pabricability NbTivaluation of different superconducto~ materials is to investSupec-conductors , " in Superconductor Materials Science,

  4. Final Scientific/Technical Report for DOE/EERE project Advanced Magnetic Refrigerant Materials

    SciTech Connect (OSTI)

    Johnson, Francis

    2014-06-30T23:59:59.000Z

    A team led by GE Global Research developed new magnetic refrigerant materials needed to enhance the commercialization potential of residential appliances such as refrigerators and air conditioners based on the magnetocaloric effect (a nonvapor compression cooling cycle). The new magnetic refrigerant materials have potentially better performance at lower cost than existing materials, increasing technology readiness level. The performance target of the new magnetocaloric material was to reduce the magnetic field needed to achieve 4 °C adiabatic temperature change from 1.5 Tesla to 0.75 Tesla. Such a reduction in field minimizes the cost of the magnet assembly needed for a magnetic refrigerator. Such a reduction in magnet assembly cost is crucial to achieving commercialization of magnetic refrigerator technology. This project was organized as an iterative alloy development effort with a parallel material modeling task being performed at George Washington University. Four families of novel magnetocaloric alloys were identified, screened, and assessed for their performance potential in a magnetic refrigeration cycle. Compositions from three of the alloy families were manufactured into regenerator components. At the beginning of the project a previously studied magnetocaloric alloy was selected for manufacturing into the first regenerator component. Each of the regenerators was tested in magnetic refrigerator prototypes at a subcontractor at at GE Appliances. The property targets for operating temperature range, operating temperature control, magnetic field sensitivity, and corrosion resistance were met. The targets for adiabatic temperature change and thermal hysteresis were not met. The high thermal hysteresis also prevented the regenerator components from displaying measurable cooling power when tested in prototype magnetic refrigerators. Magnetic refrigerant alloy compositions that were predicted to have low hysteresis were not attainable with conventional alloy processing methods. Preliminary experiments with rapid solidification methods showed a path towards attaining low hysteresis compositions should this alloy development effort be continued.

  5. The Magnificent Seven: Magnetic fields and surface temperature distributions

    E-Print Network [OSTI]

    F. Haberl

    2006-09-04T23:59:59.000Z

    Presently seven nearby radio-quiet isolated neutron stars discovered in ROSAT data and characterized by thermal X-ray spectra are known. They exhibit very similar properties and despite intensive searches their number remained constant since 2001 which led to their name ``The Magnificent Seven''. Five of the stars exhibit pulsations in their X-ray flux with periods in the range of 3.4 s to 11.4 s. XMM-Newton observations revealed broad absorption lines in the X-ray spectra which are interpreted as cyclotron resonance absorption lines by protons or heavy ions and / or atomic transitions shifted to X-ray energies by strong magnetic fields of the order of 10^13 G. New XMM-Newton observations indicate more complex X-ray spectra with multiple absorption lines. Pulse-phase spectroscopy of the best studied pulsars RX J0720.4-3125 and RBS 1223 reveals variations in derived emission temperature and absorption line depth with pulse phase. Moreover, RX J0720.4-3125 shows long-term spectral changes which are interpreted as due to free precession of the neutron star. Modeling of the pulse profiles of RX J0720.4-3125 and RBS 1223 provides information about the surface temperature distribution of the neutron stars indicating hot polar caps which have different temperatures, different sizes and are probably not located in antipodal positions.

  6. Characterizing artificial electromagnetic materials and their hybridization with fundamentally resonant magnetic materials

    E-Print Network [OSTI]

    Gollub, Jonah Nathan

    2008-01-01T23:59:59.000Z

    4 Ferromagnetic Materials in Microstrip Structures . . . 4.1Ferromagnetic Materials . . . . . . . . . . . . . . 4.3 The1: positive material 1 , µ 1 > 0 . . . . . . . . . . . . . .

  7. Use of magnetic carbon composites from renewable resource materials for oil spill clean up and recovery

    DOE Patents [OSTI]

    Viswanathan, Tito

    2014-02-11T23:59:59.000Z

    A method for separating a liquid hydrocarbon material from a body of water. In one embodiment, the method includes the steps of mixing a plurality of magnetic carbon-metal nanocomposites with a liquid hydrocarbon material dispersed in a body of water to allow the plurality of magnetic carbon-metal nanocomposites each to be adhered by an amount of the liquid hydrocarbon material to form a mixture, applying a magnetic force to the mixture to attract the plurality of magnetic carbon-metal nanocomposites each adhered by an amount of the liquid hydrocarbon material, and removing said plurality of magnetic carbon-metal nanocomposites each adhered by an amount of the liquid hydrocarbon material from said body of water while maintaining the applied magnetic force, wherein the plurality of magnetic carbon-metal nanocomposites is formed by subjecting one or more metal lignosulfonates or metal salts to microwave radiation, in presence of lignin/derivatives either in presence of alkali or a microwave absorbing material.

  8. The crucial role of surface magnetic fields for the solar dynamo

    E-Print Network [OSTI]

    Cameron, Robert

    2015-01-01T23:59:59.000Z

    Sunspots and the plethora of other phenomena occuring in the course of the 11-year cycle of solar activity are a consequence of the emergence of magnetic flux at the solar surface. The observed orientations of bipolar sunspot groups imply that they originate from toroidal (azimuthally orientated) magnetic flux in the convective envelope of the Sun. We show that the net toroidal magnetic flux generated by differential rotation within a hemisphere of the convection zone is determined by the emerged magnetic flux at the solar surface and thus can be calculated from the observed magnetic field distribution. The main source of the toroidal flux is the roughly dipolar surface magnetic field at the polar caps, which peaks around the minima of the activity cycle.

  9. Surface Extraction from Multi-Material Components for Metrology using Dual Energy CT

    E-Print Network [OSTI]

    materials (e.g., carbon-fibre-reinforced plas- tics) induce manufacturers to design new functionSurface Extraction from Multi-Material Components for Metrology using Dual Energy CT Christoph surface models of multi-material components using dual energy com- puted tomography (DECT

  10. Removal of radioactive materials and heavy metals from water using magnetic resin

    DOE Patents [OSTI]

    Kochen, Robert L. (Boulder, CO); Navratil, James D. (Simi Valley, CA)

    1997-01-21T23:59:59.000Z

    Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately.

  11. Removal of radioactive materials and heavy metals from water using magnetic resin

    DOE Patents [OSTI]

    Kochen, R.L.; Navratil, J.D.

    1997-01-21T23:59:59.000Z

    Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately. 9 figs.

  12. Thermal Stability of MnBi Magnetic Materials. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    because Mn is easy to react with oxygen. MnO formation is irreversible and causes degradation to the magnetic properties. In this paper, we report our effort on developing MnBi...

  13. Special-purpose materials for magnetically confined fusion reactors. Third annual progress report

    SciTech Connect (OSTI)

    Not Available

    1981-11-01T23:59:59.000Z

    The scope of Special Purpose Materials covers fusion reactor materials problems other than the first-wall and blanket structural materials, which are under the purview of the ADIP, DAFS, and PMI task groups. Components that are considered as special purpose materials include breeding materials, coolants, neutron multipliers, barriers for tritium control, materials for compression and OH coils and waveguides, graphite and SiC, heat-sink materials, ceramics, and materials for high-field (>10-T) superconducting magnets. It is recognized that there will be numerous materials problems that will arise during the design and construction of large magnetic-fusion energy devices such as the Engineering Test Facility (ETF) and Demonstration Reactor (DEMO). Most of these problems will be specific to a particular design or project and are the responsibility of the project, not the Materials and Radiation Effects Branch. Consequently, the Task Group on Special Purpose Materials has limited its concern to crucial and generic materials problems that must be resolved if magnetic-fusion devices are to succeed. Important areas specifically excluded include low-field (8-T) superconductors, fuels for hybrids, and materials for inertial-confinement devices. These areas may be added in the future when funding permits.

  14. 3.15 Electrical, Optical & Magnetic Materials and Devices, Fall 2003

    E-Print Network [OSTI]

    Ross, Caroline A.

    Explores the relationships which exist between the performance of electrical, optical, and magnetic devices and the microstructural characteristics of the materials from which they are constructed. Features a device-motivated ...

  15. Development of Apple Workgroup Cluster and Parallel Computing for Phase Field Model of Magnetic Materials 

    E-Print Network [OSTI]

    Huang, Yongxin

    2010-01-16T23:59:59.000Z

    using MPI. The results show the cluster system can simultaneously support up to 32 processes for MPI program with high performance of interprocess communication. The parallel computations of phase field model of magnetic materials implemented by a MPI...

  16. ELSEWER Journal of Magnetism and Magnetic Materials 169 (1997) 261-270 Superparamagnetic behavior of Fe,GaAs precipitates in GaAs

    E-Print Network [OSTI]

    Woodall, Jerry M.

    ELSEWER Journal of Magnetism and Magnetic Materials 169 (1997) 261-270 Superparamagnetic behavior; revised 6 December 1996 Abstract We present magnetization measurements on Fe3GaAs clusters distributed-dependent magnetization well above the blocking temperature indicate a particle size distribution in agreement

  17. Magnetic properties of Ni-Fe nanowire arrays: effect of template material and deposition conditions

    SciTech Connect (OSTI)

    Singleton, John [Los Alamos National Laboratory; Aravamudhan, Shyan [U OF SOUTH FL; Goddard, Paul A [U OF OXFORD; Bhansali, Shekhar [U OF SOUTH FL

    2008-01-01T23:59:59.000Z

    The objective of this work is to study the magnetic properties of arrays of Ni-Fe nanowires electrodeposited in different template materials such as porous silicon, polycarbonate and alumina. Magnetic properties were studied as a function of template material, applied magnetic field (parallel and perpendicular) during deposition, wire length, as well as magnetic field orientation during measurement. The results show that application of magnetic field during deposition strongly influences the c-axis preferred orientation growth of Ni-Fe nanowires. The samples with magnetic field perpendicular to template plane during deposition exhibits strong perpendicular anisotropy with greatly enhanced coercivity and squareness ratio, particularly in Ni-Fe nanowires deposited in polycarbonate templates. In case of polycarbonate template, as magnetic field during deposition increases, both coercivity and squareness ratio also increase. The wire length dependence was also measured for polycarbonate templates. As wire length increases, coercivity and squarness ratio decrease, but saturation field increases. Such magnetic behavior (dependence on template material, magnetic field, wire length) can be qualitatively explained by preferential growth phenomena, dipolar interactions among nanowires, and perpendicular shape anisotropy in individual nanowires.

  18. Fermi Surface of Uranium at Ambient Pressure Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Fermi Surface of ­Uranium at Ambient Pressure Gregory S. Boebinger, National High Magnetic Field Laboratory DMR-Award 0654118 DC Field Facility User Program The fermi surface of ­Uranium has been measured surface of alpha-uranium at ambient pressure, Phys. Rev. B Rapid Commun., 80, 241101 (2009). B//c-axis B

  19. Wave Turbulence on the Surface of a Ferrofluid in a Magnetic Field Francois Boyer and Eric Falcon*

    E-Print Network [OSTI]

    Falcon, Eric

    Wave Turbulence on the Surface of a Ferrofluid in a Magnetic Field Franc¸ois Boyer and Eric Falcon the observation of wave turbulence on the surface of a ferrofluid mechanically forced and submitted to a static normal magnetic field. We show that magnetic surface waves arise only above a critical field. The power

  20. Wave turbulence on the surface of a ferrofluid submitted to a magnetic field Francois Boyer and Eric Falcon

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Wave turbulence on the surface of a ferrofluid submitted to a magnetic field Fran¸cois Boyer the observation of wave turbulence on the surface of a ferrofluid mechanically forced and submitted to a static normal magnetic field. We show that magnetic surface waves arise only above a critical field. The power

  1. Exploring Ultrahigh Magnetic Field Processing of Materials for Developing Customized Microstructures and Enhanced Performance

    SciTech Connect (OSTI)

    Ludtka, GERALD M.

    2005-03-31T23:59:59.000Z

    Thermodynamic calculations based on Gibbs free energy in the magnetization-magnetic intensity-temperature (M-H-T) magnetic equation of state space demonstrate that significantly different phase equilibria may result for those material systems where the product and parent phases exhibit different magnetization responses. These calculations show that the Gibbs free energy is changed by a factor equal to -MdH, where M and H are the magnetization and applied field strength, respectively. Magnetic field processing is directly applicable to a multitude of alloys and compounds for dramatically influencing phase stability and phase transformations. This ability to selectively control microstructural stability and alter transformation kinetics through appropriate selection of the magnetic field strength promises to provide a very robust mechanism for developing and tailoring enhanced microstructures (and even nanostructures through accelerated kinetics) with superior properties for a broad spectrum of material applications. For this Industrial Materials for the Future (IMF) Advanced Materials for the Future project, ferrous alloys were studied initially since this alloy family exhibits ferromagnetism over part of its temperature range of stability and therefore would demonstrate the maximum impact of this novel processing mechanism. Additionally, with these ferrous alloys, the high-temperature parent phase, austenite, exhibits a significantly different magnetization response from the potential product phases, ferrite plus carbide or martensite; and therefore, the solid-state transformation behavior of these alloys will be dramatically influenced by the presence of ultrahigh magnetic fields. Finally, a thermodynamic calculation capability (within ThermoCalc for example) was developed during this project to enable parametric studies to be performed to predict the magnitude of the influence of magnetic processing variables on the phase stability (phase diagrams) in ferromagnetic materials of relevance to the Industries of the Future (IOF).

  2. Seeing the magnetic monopole through the mirror of topological surface states

    SciTech Connect (OSTI)

    Qi, Xiao-Liang; Li, Rundong; /Stanford U., Phys. Dept.; Zang, Jiadong; /Fudan U.; Zhang, Shou-Cheng; /Stanford U., Phys. Dept. /Fudan U.

    2010-03-25T23:59:59.000Z

    Existence of the magnetic monopole is compatible with the fundamental laws of nature, however, this illusive particle has yet to be detected experimentally. In this work, we show that an electric charge near the topological surface state induces an image magnetic monopole charge due to the topological magneto-electric effect. The magnetic field generated by the image magnetic monopole can be experimentally measured, and the inverse square law of the field dependence can be determined quantitatively. We propose that this effect can be used to experimentally realize a gas of quantum particles carrying fractional statistics, consisting of the bound states of the electric charge and the image magnetic monopole charge.

  3. Surface passivation process of compound semiconductor material using UV photosulfidation

    DOE Patents [OSTI]

    Ashby, Carol I. H. (Edgewood, NM)

    1995-01-01T23:59:59.000Z

    A method for passivating compound semiconductor surfaces by photolytically disrupting molecular sulfur vapor with ultraviolet radiation to form reactive sulfur which then reacts with and passivates the surface of compound semiconductors.

  4. Surface space : digital manufacturing techniques and emergent building material

    E-Print Network [OSTI]

    Ho, Joseph Chi-Chen, 1975-

    2002-01-01T23:59:59.000Z

    This thesis explores tectonic possibilities of new material and forming techniques. The design process is catalyzed by experimenting different configurations of the material.This project attempts to develop inventive ways ...

  5. An in-situ accelerator-based diagnostic for plasma-material interactions science in magnetic fusion devices

    E-Print Network [OSTI]

    Hartwig, Zachary Seth

    2014-01-01T23:59:59.000Z

    Plasma-material interactions (PMI) in magnetic fusion devices such as fuel retention, material erosion and redeposition, and material mixing present significant scientific and engineering challenges, particularly for the ...

  6. A PHASE CHANGE MICROVALVE USING A MELTABLE MAGNETIC MATERIAL: FERRO-WAX

    E-Print Network [OSTI]

    Oh, Kwang W.

    A PHASE CHANGE MICROVALVE USING A MELTABLE MAGNETIC MATERIAL: FERRO-WAX Kwang W. Oh, Kak Namkoong This paper presents a novel phase change microvalve using a paraffin-based ferrofluid plug (called "Ferro-Wax"). The Ferro-Wax plug is essentially leak-proof because of the phase change nature of the material; once

  7. Abstract --In electromagnetic applications, hysteresis phenomena in magnetic materials are responsible of

    E-Print Network [OSTI]

    Boyer, Edmond

    rotation. Furthermore, based on the balance of chemical equation analogies, this model has the advantage13. M M Abstract -- In electromagnetic applications, hysteresis phenomena in magnetic materials the implementation proceeding used for some hysteresis material models and how they are applied in a sensor study

  8. Model for dynamic self-assembled magnetic surface structures.

    SciTech Connect (OSTI)

    Belkin, M.; Glatz, A.; Snezhko, A.; Aranson, I. S.; Materials Science Division; Northwestern Univ.

    2010-07-07T23:59:59.000Z

    We propose a first-principles model for the dynamic self-assembly of magnetic structures at a water-air interface reported in earlier experiments. The model is based on the Navier-Stokes equation for liquids in shallow water approximation coupled to Newton equations for interacting magnetic particles suspended at a water-air interface. The model reproduces most of the observed phenomenology, including spontaneous formation of magnetic snakelike structures, generation of large-scale vortex flows, complex ferromagnetic-antiferromagnetic ordering of the snake, and self-propulsion of bead-snake hybrids.

  9. Cheaper magnetic material for cars, wind turbines created | The...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and instead uses cerium, the most abundant rare earth. The result, an alloy of neodymium, iron and boron co-doped with cerium and cobalt, is a less expensive material...

  10. Journal of Magnetism and Magnetic Materials 288 (2005) 196204 Micromagnetic studies of nickel microbars fabricated by

    E-Print Network [OSTI]

    Pesic, Batric

    2005-01-01T23:59:59.000Z

    Abstract Micromagnetic configurations and macromagnetic properties of electrodeposited nickel microbars: 75.50.Cc; 75.75.+a; 81.15.Pq Keywords: Electrodeposited nickel; Magnetic microbar; Magnetic vortex (VSM) studies of nickel microbars with round corners, produced by nanoimprinting and electrodeposition

  11. Improved Bounds on the Effective Yield Surface of Inhomogeneous Rigid/Plastic Materials

    E-Print Network [OSTI]

    Olson, Tamara

    Improved Bounds on the Effective Yield Surface of Inhomogeneous Rigid/Plastic Materials Tamara January 1993 Abstract The yield surface of a mixture of rigid/perfectly­plastic materials is examined plasticity under suffi­ ciently large stress. The set of stresses at which the deformation changes from

  12. Hydrogenated Bilayer Wurtzite SiC Nanofilms: A Two-Dimensional Bipolar Magnetic Semiconductor Material

    E-Print Network [OSTI]

    Yuan, Long; Yang, Jinlong

    2012-01-01T23:59:59.000Z

    Recently, a new kind of spintronics materials, bipolar magnetic semiconductor (BMS), has been proposed. The spin polarization of BMS can be conveniently controlled by a gate voltage, which makes it very attractive in device engineering. Now, the main challenge is finding more BMS materials. In this article, we propose that hydrogenated wurtzite SiC nanofilm is a two-dimensional BMS material. Its BMS character is very robust under the effect of strain, substrate, or even a strong electric field. The proposed two-dimensional BMS material paves the way to use this promising new material in an integrated circuit.

  13. Self assembled molecular monolayers on high surface area materials as molecular getters

    DOE Patents [OSTI]

    King, D.E.; Herdt, G.C.; Czanderna, A.W.

    1997-01-07T23:59:59.000Z

    The present invention relates to a gettering material that may be used as a filtration medium to remove pollutants from the environment. The gettering material comprises a high surface area material having a metal surface that chemically bonds n-alkanethiols in an organized manner thereby forming a molecular monolayer over the metal surface. The n-alkanethiols have a free functional group that interacts with the environment thereby binding specific pollutants that may be present. The gettering material may be exposed to streams of air in heating, ventilation, and air conditioning systems or streams of water to remove specific pollutants from either medium. 9 figs.

  14. Self assembled molecular monolayers on high surface area materials as molecular getters

    DOE Patents [OSTI]

    King, David E. (Lakewood, CO); Herdt, Gregory C. (Denver, CO); Czanderna, Alvin W. (Denver, CO)

    1997-01-01T23:59:59.000Z

    The present invention relates to a gettering material that may be used as a filtration medium to remove pollutants from the environment. The gettering material comprises a high surface area material having a metal surface that chemically bonds n-alkanethiols in an organized manner thereby forming a molecular monolayer over the metal surface. The n-alkanethiols have a free functional group that interacts with the environment thereby binding specific pollutants that may be present. The gettering material may be exposed to streams of air in heating, ventilation, and air conditioning systems or streams of water to remove specific pollutants from either medium.

  15. Reduction of surface leakage current by surface passivation of CdZn Te and other materials using hyperthermal oxygen atoms

    DOE Patents [OSTI]

    Hoffbauer, Mark A. (Los Alamos, NM); Prettyman, Thomas H. (Los Alamos, NM)

    2001-01-01T23:59:59.000Z

    Reduction of surface leakage current by surface passivation of Cd.sub.1-x Zn.sub.x Te and other materials using hyperthermal oxygen atoms. Surface effects are important in the performance of CdZnTe room-temperature radiation detectors used as spectrometers since the dark current is often dominated by surface leakage. A process using high-kinetic-energy, neutral oxygen atoms (.about.3 eV) to treat the surface of CdZnTe detectors at or near ambient temperatures is described. Improvements in detector performance include significantly reduced leakage current which results in lower detector noise and greater energy resolution for radiation measurements of gamma- and X-rays, thereby increasing the accuracy and sensitivity of measurements of radionuclides having complex gamma-ray spectra, including special nuclear materials.

  16. Multi-Instrument Characterization of the Surfaces and Materials...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of our materials than a single technique, which is analogous to the story of ‘The Blind Men and the Elephant’. (Of course there is increasing emphasis on the use of...

  17. Use of High Magnetic Fields to Improve Material Properties for Hydraulics, Automotive and Truck Components

    SciTech Connect (OSTI)

    Ludtka, Gerard Michael [ORNL; Ludtka, Gail Mackiewicz- [ORNL; Wilgen, John B [ORNL; Kisner, Roger A [ORNL; Ahmad, Aquil [Eaton Corporation

    2010-08-01T23:59:59.000Z

    In this CRADA, research and development activities were successfully conducted on magnetic processing effects for the purpose of manipulating microstructure and the application specific performance of three alloys provided by Eaton (alloys provided were: carburized steel, plain low carbon steel and medium carbon spring steel). Three specific industrial/commercial application areas were considered where HMFP can be used to provide significant energy savings and improve materials performance include using HMFP to: 1.) Produce higher material strengths enabling higher torque bearing capability for drive shafts and other motor components; 2.) Increase the magnetic response in an iron-based material, thereby improving its magnetic permeability resulting in improved magnetic coupling and power density, and 3.) Improve wear resistance. The very promising results achieved in this endeavor include: 1.) a significant increase in tensile strength and a major reduction in volume percent retained austenite for the carburized alloy, and 2.) a substantial improvement in magnetic perm respect to a no-field processed sample (which also represents a significant improvement over the nominal conventional automotive condition of no heat treatment). The successful completion of these activities has resulted in the current 3-year CRADA No. NFE-09-02522 Prototyping Energy Efficient ThermoMagnetic and Induction Hardening for Heat Treat and Net Shape Forming Applications .

  18. Neutron star envelopes and thermal radiation from the magnetic surface

    E-Print Network [OSTI]

    J. Ventura; A. Y. Potekhin

    2001-03-31T23:59:59.000Z

    The thermal structure of neutron star envelopes is discussed with emphasis on analytic results. Recent progress on the effect of chemical constitution and high magnetic fields on the opacities and the thermal structure is further reviewed in view of the application to pulsar cooling and magnetars.

  19. Influence of surface spins on the magnetization of fine maghemite nanoparticles

    SciTech Connect (OSTI)

    Nadeem, K. [Department of Physics, International Islamic University, H-10, Islamabad (Pakistan); Krenn, H. [Institute of Physics, Karl-Franzens University Graz, Universitätsplatz 5, A-8010 Graz (Austria); Szabó, D. V. [Institute for Advanced Materials-Materials Process Technology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany)

    2013-12-16T23:59:59.000Z

    Influence of surface spins on magnetization of maghemite nanoparticles have been studied by using SQUID measurements and also comparison done with theoretical simulations. Surface spin disorder arises in these nanoparticles due to the randomness of surface spins. A model of AC-susceptibility has been used to investigate the experimental results. The comparison between experiment and theory signifies the presence of large effective anisotropy and freezing effects on the surface of maghemite nanoparticles. The enhanced effective anisotropy constant of these nanoparticles as compared to bulk maghemite is due to presence of disordered surface spins.

  20. Carbon-Based Materials, High-Surface-Area Sorbents, and New Materials and Concepts

    Broader source: Energy.gov [DOE]

    This category of materials-based storage technologies includes a range of carbon-based materials such as carbon nanotubes, aerogels, nanofibers (including metal-doped hybrids), as well as metal...

  1. Surface-Modified Active Materials for Lithium Ion Battery Electrodes -

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructure ofIndustrialSupportingAlbedo at theSurface SoilSurfaceEnergy

  2. Magnetic tunable microstructured surfaces for thermal management and microfluidic applications

    E-Print Network [OSTI]

    Zhu, Yangying

    2013-01-01T23:59:59.000Z

    Micro and nanostructured surfaces have broad applications including heat transfer enhancement in phase-change systems and liquid manipulation in microfluidic devices. While significant efforts have focused on fabricating ...

  3. Non-Rare Earth magnetic materials | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin of Contamination in Many DevilsForumEnginesVacantmagnetic materials Non-Rare Earth

  4. Production of Materials with Superior Properties Utilizing High Magnetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah47,193.70 Hg Mercury 35 BrProcurementRaw Materials - EnergyField -

  5. THERMAL IMAGING OF ACTIVE MAGNETIC REGERNERATOR MCE MATERIALS DURING OPERATION

    SciTech Connect (OSTI)

    Shassere, Benjamin [ORNL] [ORNL; West, David L [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL; Evans III, Boyd Mccutchen [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    An active magnetic regenerator (AMR) prototype was constructed that incorporates a Gd sheet into the regenerator wall to enable visualization of the system s thermal transients. In this experiment, the thermal conditions inside the AMR are observed under a variety of operating conditions. An infrared (IR) camera is employed to visualize the thermal transients within the AMR. The IR camera is used to visually and quantitatively evaluate the temperature difference and thus giving means to calculate the performance of the system under the various operating conditions. Thermal imaging results are presented for two differing experimental test runs. Real time imaging of the thermal state of the AMR has been conducted while operating the system over a range of conditions. A 1 Tesla twin-coil electromagnet (situated on a C frame base) is used for this experiment such that all components are stationary during testing. A modular, linear reciprocating system has been realized in which the effects of regenerator porosity and utilization factor can be investigated. To evaluate the performance variation in porosity and utilization factor the AMR housing was constructed such that the plate spacing of the Gd sheets may be varied. Each Gd sheet has dimensions of 38 mm wide and 66 mm long with a thickness of 1 mm and the regenerator can hold a maximum of 29 plates with a spacing of 0.25 mm. Quantitative and thermal imaging results are presented for several regenerator configurations.

  6. Surface Finish Modeling in Micromilling of Biocompatible Materials

    E-Print Network [OSTI]

    Berestovskyi, Dmytro V

    2013-06-05T23:59:59.000Z

    the requirements listed above. Computer controlled micromilling on a high speed machine system in minimum quantity lubrication was used to remove most materials and define a channel pattern. Microchannels were machined with ball end mills of diameters from Ø152?m...

  7. Surface Finish Modeling in Micromilling of Biocompatible Materials 

    E-Print Network [OSTI]

    Berestovskyi, Dmytro V

    2013-06-05T23:59:59.000Z

    of 6061-T6 Aluminum Alloy and A36 Low Carbon Steel ............................................................................................. 68 Table 10. Solutions for Chemical Etching of 304 Stainless Steel and CP Titanium ....... 72 Table 11... aspect ratio channels. In addition, chemical etching requires 2 intricate expensive mask and utilization of unique chemical solution for each material. This makes the etching process complex and time consuming. Conventional micromilling has...

  8. Correlation between topography and magnetic surface anisotropy in epitaxial Fe films on vicinal-to-(001) Au surfaces with different step orientation

    E-Print Network [OSTI]

    Demokritov, S.O.

    Correlation between topography and magnetic surface anisotropy in epitaxial Fe films on vicinal in this respect,2­5 the surface topography in these films is often very complex, characterized by surface these films on vicinal to (001) Au substrates one finds a rich variety in the surface topography. We have

  9. Carbon-Based Materials, High-Surface-Area Sorbents, and New Materials...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    technologies includes a range of carbon-based materials such as carbon nanotubes, aerogels, nanofibers (including metal-doped hybrids), as well as metal-organic frameworks,...

  10. neutron scattering shows magnetic excitation mechanism at work in new materials.

    E-Print Network [OSTI]

    neutron scattering shows magnetic excitation mechanism at work in new materials. In 2008 dai of orNl and the university of tennes- see led early neutron scattering studies of the pnictides. dai ticks off four main things neutron scattering has revealed about superconducting iron com- pounds

  11. Relation between photospheric flow fields and the magnetic field distribution on the solar surface

    SciTech Connect (OSTI)

    Simon, G.W.; Title, A.M.; Topka, K.P.; Tarbell, T.D.; Shine, R.A.

    1988-04-01T23:59:59.000Z

    Using the technique of local correlation tracking on a 28 minute time sequence of white-light images of solar granulation, the horizontal flow field on the solar surface is measured. The time series was obtained by the Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 (Space Shuttle flight 51-F) and is free from atmospheric blurring and distortion. The SOUP flow fields have been compared with carefully aligned magnetograms taken over a nine hour period at the Big Bear Solar Observatory before, during, and after the SOUP images. The flow field and the magnetic field agree in considerable detail: vectors which define the flow of the white-light intensity pattern (granulation) point toward magnetic field regions, magnetic fields surround flow cells, and magnetic features move along the flow arrows. The projected locations of free particles (corks) in the measured flow field congregate at the same locations where the magnetic field is observed. 31 references.

  12. Center for Nanophase Materials Sciences (CNMS) - STM for Oxide Surfaces,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced. C o w l i t z C oCNMS RESEARCHInstitute (NTI):CNMS NewsMolecular

  13. Magnetic properties of materials for MR engineering, micro-MR and beyond

    E-Print Network [OSTI]

    Wapler, Matthias C; Dragonu, Iulius; von Elverfeld, Dominik; Zaitsev, Maxim; Wallrabe, Ulrike

    2014-01-01T23:59:59.000Z

    We present the results of a systematic measurement of the magnetic susceptibility of small material samples in a 9.4 T MRI scanner. We measured many of the most widely used materials in MR engineering and MR micro technology, including various polymers, optical and substrate glasses, resins, glues, photoresists, PCB substrates and some fluids. Based on our data, we identify particularly suitable materials with susceptibilities close to water. For polyurethane resins and elastomers, we also show the MR spectra, as they may be a good substitute for silicone elastomers and good casting resins.

  14. Rheological behavior and cryogenic properties of cyanate ester/epoxy insulation material for fusion superconducting magnet

    SciTech Connect (OSTI)

    Wu, Z. X.; Huang, C. J. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, PR (China); Li, L. F. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China and State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, C (China); Li, J. W. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China and University of Chinese Academy of Sciences, Beijing 100049, PR (China); Tan, R.; Tu, Y. P. [North China Electric Power University, Beijing 102206, PR (China)

    2014-01-27T23:59:59.000Z

    In a Tokamak fusion reactor device like ITER, insulation materials for superconducting magnets are usually fabricated by a vacuum pressure impregnation (VPI) process. Thus these insulation materials must exhibit low viscosity, long working life as well as good radiation resistance. Previous studies have indicated that cyanate ester (CE) blended with epoxy has an excellent resistance against neutron irradiation which is expected to be a candidate insulation material for a fusion magnet. In this work, the rheological behavior of a CE/epoxy (CE/EP) blend containing 40% CE was investigated with non-isothermal and isothermal viscosity experiments. Furthermore, the cryogenic mechanical and electrical properties of the composite were evaluated in terms of interlaminar shear strength and electrical breakdown strength. The results showed that CE/epoxy blend had a very low viscosity and an exceptionally long processing life of about 4 days at 60 °C.

  15. Experimental studies of lithium-based surface chemistry for fusion plasma-facing materials applications q

    E-Print Network [OSTI]

    Harilal, S. S.

    - ments of plasma-surface interactions in tokamaks such as NSTX. Results suggest that the lithium bondingExperimental studies of lithium-based surface chemistry for fusion plasma-facing materials.65.y a b s t r a c t Lithium has enhanced the operational performance of fusion devices such as: TFTR

  16. Cavitation in elastomeric solids: II--Onset-of-cavitation surfaces for Neo-Hookean materials

    E-Print Network [OSTI]

    Lopez-Pamies, Oscar

    Cavitation in elastomeric solids: II--Onset-of-cavitation surfaces for Neo-Hookean materials Oscar a fairly general theory of cavitation in elastomeric solids based on the sudden growth of pre-existing defects. In this article, the theory is used to determine onset-of-cavitation surfaces for Neo

  17. Cavitation in elastomeric solids: II--Onset-of-cavitation surfaces for Neo-Hookean materials

    E-Print Network [OSTI]

    Nakamura, Toshio

    Cavitation in elastomeric solids: II--Onset-of-cavitation surfaces for Neo-Hookean materials Oscar of cavitation in elastomeric solids based on the sudden growth of pre-existing defects. In this article, the theory is used to determine onset-of-cavitation surfaces for Neo-Hookean solids where the defects

  18. Equilibrium behavior of sessile drops under surface tension, applied external fields, and material variations

    E-Print Network [OSTI]

    Shapiro, Benjamin

    Equilibrium behavior of sessile drops under surface tension, applied external fields, and material properties such as dielectric constants, resistivities, and surface tension coefficients. The analysis energy storage in the liquid, will lead to 1/R ``line-tension''-type terms if and only if the energy

  19. Propagation of surface waves on a semi-bounded quantum magnetized collisional plasma

    SciTech Connect (OSTI)

    Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)] [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of); Taheri Boroujeni, S.; Khorashadizadeh, S. M. [Physics Department, University of Birjand, Birjand (Iran, Islamic Republic of)] [Physics Department, University of Birjand, Birjand (Iran, Islamic Republic of)

    2013-12-15T23:59:59.000Z

    The propagation of surface waves on a semi-bounded quantum plasma in the presence of the external magnetic field and collisional effects is investigated by using quantum magnetohydrodynamics model. A general analytical expression for the dispersion relation of surface waves is obtained by considering the boundary conditions. It is shown that, in some special cases, the obtained dispersion relation reduces to the results reported in previous works. It is also indicated that the quantum, external magnetic field and collisional effects can facilitate the propagation of surface waves on a semi-bounded plasma. In addition, it is found that the growth rate of the surface wave instability is enhanced by increasing the collision frequency and plasmonic parameter.

  20. Materials of interaction : responsive materials in the design of transformable interactive surfaces

    E-Print Network [OSTI]

    Coelho, Marcelo

    2008-01-01T23:59:59.000Z

    Materials that embody computational properties are reshaping the ways in which we design, interact and communicate. This thesis looks at the topic of form transformation and how to bring the programmability and versatility ...

  1. A PARAMETRIC STUDY OF BCS RF SURFACE IMPEDANCE WITH MAGNETIC FIELD USING THE XIAO CODE

    SciTech Connect (OSTI)

    Reece, Charles E. [JLAB; Xiao, Binping [JLAB, BNL

    2013-09-01T23:59:59.000Z

    A recent new analysis of field-dependent BCS rf surface impedance based on moving Cooper pairs has been presented.[1] Using this analysis coded in Mathematica TM, survey calculations have been completed which examine the sensitivities of this surface impedance to variation of the BCS material parameters and temperature. The results present a refined description of the "best theoretical" performance available to potential applications with corresponding materials.

  2. Ultra-low field nuclear magnetic resonance and magnetic resonance imaging to discriminate and identify materials

    SciTech Connect (OSTI)

    Matlashov, Andrei Nikolaevich; Urbaitis, Algis V.; Savukov, Igor Mykhaylovich; Espy, Michelle A.; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry

    2013-03-05T23:59:59.000Z

    Method comprising obtaining an NMR measurement from a sample wherein an ultra-low field NMR system probes the sample and produces the NMR measurement and wherein a sampling temperature, prepolarizing field, and measurement field are known; detecting the NMR measurement by means of inductive coils; analyzing the NMR measurement to obtain at least one measurement feature wherein the measurement feature comprises T1, T2, T1.rho., or the frequency dependence thereof; and, searching for the at least one measurement feature within a database comprising NMR reference data for at least one material to determine if the sample comprises a material of interest.

  3. Magnetic measurement to evaluate material properties of ferromagnetic structural steels with planar coils

    SciTech Connect (OSTI)

    Ebine, Noriya; Ara, Katsuyuki

    1999-09-01T23:59:59.000Z

    The mechanical properties of a nuclear reactor pressure vessel (RPV) are degraded by fast neutron irradiation during operation. This is well-known as so-called as radiation embrittlement of RPV and an important problem to be considered in the assessment of residual life of the nuclear reactor. Hence the development of nondestructive means is required to measure directly the degree of material degradation in RPV. Here, nondestructive measurement experiments were carried out with a planar coil to evaluate changes of material properties of ferromagnetic structural steels. Examined steels were of A533B that is a low-alloy steel and of SUS410 that is a martensitic stainless steel. The planar coil has two windings; one is of primary for excitation and the other secondary for induction of output voltage. The coil was placed on a test plate with a magnetic yoke for application of a bias dc magnetic field, and excited with a constant current of 25 Hz. Then the output voltages were measured while slowly changing the bias field by excitation of the magnetic yoke with a triangular-wave form current of 0.005 Hz. Changes of output voltages with different test plates were correlated with their mechanical and magnetic properties. The correlation is so good that this measuring method could be applied to nondestructive evaluation of material degradation in ferromagnetic structural steels.

  4. Surfactant Organic Molecules Restore Magnetism in Metal-Oxide Nanoparticle Surfaces

    E-Print Network [OSTI]

    Pennycook, Steve

    acid and the nanoparticles would prevent further oxidation to Fe2O3, which could be detrimental functional calculations, we establish the key role of the nonmagnetic organic acid cappiSurfactant Organic Molecules Restore Magnetism in Metal-Oxide Nanoparticle Surfaces Juan Salafranca

  5. Small-scale dynamos on the solar surface: dependence on magnetic Prandtl number

    E-Print Network [OSTI]

    Thaler, I

    2015-01-01T23:59:59.000Z

    The question of possible small-scale dynamo action in the surface layers of the Sun is revisited with realistic 3D MHD simulations. As in other MHD problems, dynamo action is found to be a sensitive function of the magnetic Prandtl number ${\\rm P_{\\rm m} }=\

  6. Critical magnetic field of surface superconductivity in lead

    SciTech Connect (OSTI)

    Khlyustikov, I. N., E-mail: khly@kapitza.ras.ru [Russian Academy of Sciences, Kapitza Institute of Physical Problems (Russian Federation)

    2011-12-15T23:59:59.000Z

    The critical superconductivity field H{sub c3} is measured on lead single crystals. It is shown that the temperature dependence of H{sub c3}/H{sub c} in the vicinity of superconducting transition temperature T{sub c} is essentially nonlinear. Relative changes in the value of H{sub c3}/H{sub c} reach approximately 30%, which cannot be described by the Ginzburg-Landau theory. The experimental temperature dependences lead to the conclusion that the surface superconducting transition temperature noticeably exceeds the superconducting transition temperature in the bulk of the semiconductor. The differences in the critical temperatures and in the Ginzburg-Landau parameters for lead are estimated.

  7. Massive Dirac Fermion on the Surface of a Magnetically Doped Topological Insulator

    SciTech Connect (OSTI)

    Chen, Y.L.; Chu, J.-H.; Analytis, J.G.; Liu, Z.K.; Igarashi, K.; Kuo, H.-H.; Qi, X.L.; Mo, S.K.; Moore, R.G.; Lu, D.H.; Hashimoto, M.; Sasagawa, T.; Zhang, S.C.; Fisher, I.R.; Hussain, Z.; Shen, Z.-X.; /SLAC; ,

    2011-05-20T23:59:59.000Z

    Topological insulators are characterized by a massless Dirac surface state and a bulk energy gap. An insulating massive Dirac fermion state is predicted to occur if the breaking of the time reversal symmetry opens an energy gap at the Dirac point, provided that the Fermi-energy resides inside both the surface and bulk gaps. By introducing magnetic dopants into the three dimensional topological insulator Bi{sub 2}Se{sub 3} to break the time reversal symmetry, we observed the formation of a massive Dirac fermion on the surface; simultaneous magnetic and charge doping furthermore positioned the Fermi-energy inside the Dirac gap. The insulating massive Dirac Fermion state thus obtained may provide a tool for studying a range of topological phenomena relevant to both condensed matter and particle physics.

  8. A Synergy of Novel Experiments, Materials Science, Fundamental Physics, and Superconducting Magnets

    E-Print Network [OSTI]

    Godeke, Arno

    2007-01-01T23:59:59.000Z

    Fundamental Physics Superconducting Magnets Yields: Accuraterecord setting superconducting magnet systems ITER, NMRScience, Fundamental Physics, and Superconducting Magnets

  9. Need for development of higher strength cryogenic structural materials for fusion magnet

    SciTech Connect (OSTI)

    Nishimura, Arata [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul Lez Durance (France)

    2014-01-27T23:59:59.000Z

    A prototype fusion reactor is targeted as a beyond ITER project which is so called DEMO. Several conceptual designs have been carried out. Recently, in order to recognize practical aspects on maintenance of the prototype reactor, the replacement procedure of in-vessel components was focused and “sector process” was proposed. The process is that the reactor consists of sectors and all sectors will be drowned and replaced in a short time. The slim coil which generated higher magnetic field is required to realize the sector process. From the point of coil design, the occupancy of the structural material on the cross section of the coil increases with an increase of magnetic field. To realize the slim coil, the cryogenic structural material with higher yield strength and the proper toughness is desired.

  10. Method of making active magnetic refrigerant materials based on Gd-Si-Ge alloys

    DOE Patents [OSTI]

    Pecharsky, Alexandra O. (Ames, IA); Gschneidner, Jr., Karl A. (Ames, IA); Pecharsky, Vitalij K. (Ames, IA)

    2006-10-03T23:59:59.000Z

    An alloy made of heat treated material represented by Gd.sub.5(Si.sub.xGe.sub.1-x).sub.4 where 0.47.ltoreq.x.ltoreq.0.56 that exhibits a magnetic entropy change (-.DELTA.S.sub.m) of at least 16 J/kg K, a magnetostriction of at least 2000 parts per million, and a magnetoresistance of at least 5 percent at a temperature of about 300K and below, and method of heat treating the material between 800 to 1600 degrees C. for a time to this end.

  11. Surface-gasification materials program. Semiannual progress report for the period ending March 31, 1982

    SciTech Connect (OSTI)

    Not Available

    1982-08-01T23:59:59.000Z

    The objective of the Surface Gasification Materials Program is to conduct research and development on materials for application to the specific needs of coal gasification systems. The Program is divided into two subprograms: (1) the Gasification Systems Fabrication Technology Program and (2) the Materials Application and Development Program. The purpose of the Gasification Systems Fabrication Technology Program is to evaluate innovative fabrication methods which have the potential to lower costs and improve reliability and safety for gasifier vessels and components. The purpose of the Materials Application and Development Program is to conduct engineering-scale development and application of materials for coal gasification systems to ensure that the materials of construction for pilot plants and future large-scale plants can be properly selected and specified. The management of materials projects in support of surface gasification sponsored by the Headquarters DOE Gasification Division has been defined in an April 16, 1982 METC-sponsored agreement transmitted to DOE field offices and performing contractors. This agreement recognizes the lead role in fossil energy materials delegated by METC to the DOE Oak Ridge Operations Office and the Oak Ridge National Laboratory. The ORNL Fossil Energy Materials Program Office compiles and issues this combined semiannual progress report from camera-ready copies submitted by each of the participating organizations. Distribution is as shown on pages 59 to 63. Future reports will be issued on a semiannual basis to a similar distribution.

  12. Surface Gasification Materials Program. Semiannual progress report for the period ending September 30, 1982

    SciTech Connect (OSTI)

    Not Available

    1982-12-01T23:59:59.000Z

    The objective of the Surface Gasification Materials Program is to conduct research and development on materials for application to the specific needs of coal gasification systems. The Program is divided into two subprograms: (1) the Gasification Systems Fabrication Technology Program and (2) the Materials Application and Development Program. The purpose of the Gasification Systems Fabrication Technology Program is to evaluate innovative fabrication methods which have the potential to lower costs and improve reliability and safety for gasifier vessels and components. The purpose of the Materials Application and Development Program is to conduct engineering-scale development and application of materials for coal gasification systems to ensure that the materials of construction for pilot plants and future large-scale plants can be properly selected and specified. The Morgantown Energy Technology Center (METC), in its lead role for gasification projects, is responsible for ensuring that the Surface Gasification Materials Program is responsive to the needs for gasification systems. Under its lead role for fossil energy materials, the Oak Ridge Operations Office (ORO), is responsible for the planning, implementation, and management of the program in accordance with guidance received from METC. The ORNL Fossil Energy Materials Program Office compiles and issues this combined semiannual progress report from camera-ready copies submitted by each of the participating organizations.

  13. Numerical upscaling for the eddy-current model with stochastic magnetic materials

    SciTech Connect (OSTI)

    Eberhard, Jens P. [Computer Simulation Technology, Bad Nauheimer Strasse, 19, D-64289 Darmstadt (Germany)], E-mail: jens.eberhard@cst.com; Popovic, Dan [Simulation in Technology, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: dan.popovic@stud.uni-heidelberg.de; Wittum, Gabriel [Simulation in Technology, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: wittum@uni-hd.de

    2008-04-01T23:59:59.000Z

    This paper deals with the upscaling of the time-harmonic Maxwell equations for heterogeneous media. We analyze the eddy-current approximation of Maxwell's equations to describe the electric field for heterogeneous, isotropic magnetic materials. The magnetic permeability of the materials is assumed to have random heterogeneities described by a Gaussian random field. We apply the so-called Coarse Graining method to develop a numerical upscaling of the eddy-current model. The upscaling uses filtering and averaging procedures in Fourier space which results in a formulation of the eddy-current model on coarser resolution scales where the influence of sub-scale fluctuations is modeled by effective scale- and space-dependent reluctivity tensors. The effective reluctivity tensors can be obtained by solving local partial differential equations which contain a Laplacian as well as a curl-curl operator. We present a computational method how the equation of the combined operators can be discretized and solved numerically using an extended variational formulation compared to standard discretizations. We compare the results of the numerical upscaling of the eddy-current model with theoretical results of Eberhard [J.P. Eberhard, Upscaling for the time-harmonic Maxwell equations with heterogeneous magnetic materials, Physical Review E 72 (3), (2005)] and obtain a very good agreement.

  14. Hyper-resistivity and electron thermal conductivity due to destroyed magnetic surfaces in axisymmetric plasma equilibria

    SciTech Connect (OSTI)

    Weening, R. H. [Department of Radiologic Sciences, Thomas Jefferson University, 901 Walnut Street, Philadelphia, Pennsylvania 19107-5233 (United States)

    2012-06-15T23:59:59.000Z

    In order to model the effects of small-scale current-driven magnetic fluctuations in a mean-field theoretical description of a large-scale plasma magnetic field B(x,t), a space and time dependent hyper-resistivity {Lambda}(x,t) can be incorporated into the Ohm's law for the parallel electric field E Dot-Operator B. Using Boozer coordinates, a theoretical method is presented that allows for a determination of the hyper-resistivity {Lambda}({psi}) functional dependence on the toroidal magnetic flux {psi} for arbitrary experimental steady-state Grad-Shafranov axisymmetric plasma equilibria, if values are given for the parallel plasma resistivity {eta}({psi}) and the local distribution of any auxiliary plasma current. Heat transport in regions of plasma magnetic surfaces destroyed by resistive tearing modes can then be modeled by an electron thermal conductivity k{sub e}({psi})=({epsilon}{sub 0}{sup 2}m{sub e}/e{sup 2}){Lambda}({psi}), where e and m{sub e} are the electron charge and mass, respectively, while {epsilon}{sub 0} is the permittivity of free space. An important result obtained for axisymmetric plasma equilibria is that the {psi}{psi}-component of the metric tensor of Boozer coordinates is given by the relation g{sup {psi}{psi}}({psi}){identical_to}{nabla}{psi} Dot-Operator {nabla}{psi}=[{mu}{sub 0}G({psi})][{mu}{sub 0}I({psi})]/{iota}({psi}), with {mu}{sub 0} the permeability of free space, G({psi}) the poloidal current outside a magnetic surface, I({psi}) the toroidal current inside a magnetic surface, and {iota}({psi}) the rotational transform.

  15. (1) Frank May REU Summary 2012 -http://engineering.umass.edu/reu/2012/reu-students (2) "Hard Magnetic Materials: A Perspecitve" J.M.D. Coey

    E-Print Network [OSTI]

    Mountziaris, T. J.

    (1) Frank May REU Summary 2012 - http://engineering.umass.edu/reu/2012/reu-students (2) "Hard Magnetic Materials: A Perspecitve" J.M.D. Coey (3) "Perspecitve on Permanent Magnetic Materials for Energy of L10 magnetic materials" David E. Laughlin, Kumar Srinivasan, Mihaela Tanase, Lisha Wang (5) "A study

  16. Fluctuating Surface Currents: A New Algorithm for Efficient Prediction of Casimir Interactions among Arbitrary Materials in Arbitrary Geometries. I. Theory

    E-Print Network [OSTI]

    M. T. Homer Reid; Jacob White; Steven G. Johnson

    2012-07-12T23:59:59.000Z

    This paper presents a new method for the efficient numerical computation of Casimir interactions between objects of arbitrary geometries, composed of materials with arbitrary frequency-dependent electrical properties. Our method formulates the Casimir effect as an interaction between effective electric and magnetic current distributions on the surfaces of material bodies, and obtains Casimir energies, forces, and torques from the spectral properties of a matrix that quantifies the interactions of these surface currents. The method can be formulated and understood in two distinct ways: \\textbf{(1)} as a consequence of the familiar \\textit{stress-tensor} approach to Casimir physics, or, alternatively, \\textbf{(2)} as a particular case of the \\textit{path-integral} approach to Casimir physics, and we present both formulations in full detail. In addition to providing an algorithm for computing Casimir interactions in geometries that could not be efficiently handled by any other method, the framework proposed here thus achieves an explicit unification of two seemingly disparate approaches to computational Casimir physics.

  17. Simulation Study of Internal and Surface waves of Vertically Vibrated Granular Materials

    E-Print Network [OSTI]

    Kai Huang; Guoqing Miao; Peng Zhang; Yifei Zhu; Rongjue Wei

    2005-11-29T23:59:59.000Z

    Molecular dynamical (MD) simulations are performed to simulate two dimensional vibrofluidized granular materials in this work. Statistics on simulation results indicate that there exist shocks propagating upward in each vibrating cycle. Under certain driving parameters surface waves similar to Faraday instability in normal fluid coexist with internal waves. Relationship between the two kinds of waves is explored. Moreover simulation results indicate that periodically structured bottom can change the dispersion relationship and amplitude of surface waves.

  18. Nanostructured materials for lithium-ion batteries: Surface conductivity vs. bulk

    E-Print Network [OSTI]

    Ryan, Dominic

    Nanostructured materials for lithium-ion batteries: Surface conductivity vs. bulk ion cathode materials for high capacity lithium-ion batteries. Owing to their inherently low electronic-ion batteries. Lithium transition metal phosphates such as LiFePO4,1 LiMnPO4,2 Li3V2(PO4)3 3 and LiVPO4F4 have

  19. Rayleigh waves and surface stability for Bell materials in compression; comparison with rubber

    E-Print Network [OSTI]

    Michel Destrade

    2013-04-30T23:59:59.000Z

    The stability of a Bell-constrained half-space in compression is studied. To this end, the propagation of Rayleigh waves on the surface of the material when it is maintained in a static state of triaxial prestrain is considered. The prestrain is such that the free surface of the half-space is a principal plane of deformation. The exact secular equation is established for surface waves traveling in a principal direction of strain with attenuation along the principal direction normal to the free plane. As the half-space is put under increasing compressive loads, the speed of the wave eventually tends to zero and the bifurcation criterion, or stability equation, is reached. Then the analysis is specialized to specific forms of strain energy functions and prestrain, and comparisons are made with results previously obtained in the case of incompressible neo-Hookean or Mooney-Rivlin materials. It is found that these rubber-like incompressible materials may be compressed more than "Bell empirical model" materials, but not as much as "Bell simple hyperelastic" materials, before the critical stretches, solutions to the bifurcation criterion, are reached. In passing, some classes of incompressible materials which possess a relative-universal bifurcation criterion are presented.

  20. Surface driven effects on magnetic properties of antiferromagnetic LaFeO{sub 3} nanocrystalline ferrite

    SciTech Connect (OSTI)

    Sendil Kumar, A., E-mail: sendilphy@gmail.com, E-mail: anilb42@gmail.com [School of Physics, University of Hyderabad, Hyderabad, Telangana 500 046 (India); Manivel Raja, M. [Advanced Magnetics Group, Defence Metallurgical Research Laboratory, Hyderabad, Telangana 500 058 (India); Bhatnagar, Anil K., E-mail: sendilphy@gmail.com, E-mail: anilb42@gmail.com [School of Physics, University of Hyderabad, Hyderabad, Telangana 500 046 (India); School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad, Telangana 500 046 (India)

    2014-09-21T23:59:59.000Z

    LaFeO{sub 3} nanocrystalline ferrites were synthesized through sol-gel method in different size distributions and the effect of finite size on magnetic properties is investigated. Results of magnetization and Mössbauer measurements show that superparamagnetism and weak ferromagnetic behavior in some of the size distributions. The origin of the superparamagnetism is from fine particles similar to ferromagnetic single domains and the weak ferromagnetism comes from surface spin disorder caused by Dzyaloshinskii-Moriya interaction. The magnetic ground state of LaFeO{sub 3} nanoparticles differs from that of bulk, and the ground state is dictated by the finite size effect because density of states depends on the dimensionality of the sample.

  1. Materials Science and Engineering B 126 (2006) 230235 Alloying, co-doping, and annealing effects on the magnetic and optical

    E-Print Network [OSTI]

    Dietz, Nikolaus

    are formed. Atomic force microscopy revealed MOCVD-like step flow growth patterns and a mean surface consist of semi- conductors doped with rare earth or transition metals to provide magnetic functionality on the magnetic and optical properties of MOCVD-grown Ga1-xMnxN Matthew H. Kanea,b, Martin Strassburga,d, Ali

  2. Final Report-MATERIALS, STRANDS, AND CABLES FOR SUPERCONDUCTING ACCELERATOR MAGNETS

    SciTech Connect (OSTI)

    Sumption, Mike D [OSU; Collings, E W

    2014-09-19T23:59:59.000Z

    This report focuses on Materials, Strands and Cables for High Energy Physics Particle accelerators. In the materials area, work has included studies of basic reactions, diffusion, transformations, and phase assemblage of Nb3Sn. These materials science aspects have been married to results, in the form of flux pinning, Bc2, Birr, and transport Jc, with an emphasis on obtaining the needed Jc for HEP needs. Attention has also been paid to the “intermediate-temperature superconductor”, magnesium diboride emphasis being placed on (i) irreversibility field enhancement, (ii) critical current density and flux pinning, and (iii) connectivity. We also report on studies of Bi-2212. The second area of the program has been in the area of “Strands” in which, aside from the materials aspect of the conductor, its physical properties and their influence on performance have been studied. Much of this work has been in the area of magnetization estimation and flux jump calculation and control. One of the areas of this work was strand instabilities in high-performance Nb3Sn conductors due to combined fields and currents. Additionally, we investigated quench and thermal propagation in YBCO coated conductors at low temperatures and high fields. The last section, “Cables”, focussed on interstrand contact resistance, ICR, it origins, control, and implications. Following on from earlier work in NbTi, the present work in Nb3Sn has aimed to make ICR intermediate between the two extremes of too little contact (no current sharing) and too much (large and unacceptable magnetization and associated beam de-focussing). Interstrand contact and current sharing measurements are being made on YBCO based Roebel cables using transport current methods. Finally, quench was investigated for YBCO cables and the magnets wound from them, presently with a focus on 50 T solenoids for muon collider applications.

  3. Relation between convection flows and magnetic structure at the solar surface

    SciTech Connect (OSTI)

    Simon, G.W.; November, L.J.; Action, L.W.; Title, A.M.; Tarbell, T.D.

    1988-01-01T23:59:59.000Z

    Recent results from comparison of data from the Solar Optical Universal Polarimeter instrument of Spacelab 2 and magnetograms from Big Bear Solar Observatory are described. It is shown that the Sun's surface velocity field governs the structure of the observed magnetic field over the entire solar surface outside sunspots and pores. The authors attempt to describe the observed flows by a simple axisymmetric plume model. Finally, they suggest that these observations may have important implications for the prediction of solar flares, mass ejections, and coronal heating.

  4. W.E. Henry Symposium compendium: The importance of magnetism in physics and material science

    SciTech Connect (OSTI)

    Carwell, H.

    1997-09-19T23:59:59.000Z

    This compendium contains papers presented at the W. E. Henry Symposium, The Importance of Magnetism in Physics and Material Science. The one-day symposium was conducted to recognize the achievements of Dr. Warren Elliot Henry as educator, scientist, and inventor in a career spanning almost 70 years. Dr. Henry, who is 88 years old, attended the symposium. Nobel Laureate, Dr. Glenn Seaborg, a friend and colleague for over 40 years, attended the event and shared his personal reminiscences. Dr. Seaborg is Associate Director-At-Large at the Lawrence Berkeley National Laboratory. The Compendium begins with three papers which demonstrate the ongoing importance of magnetism in physics and material science. Other contributions cover the highlights of Dr. Henry`s career as a researcher, educator, and inventor. Colleagues and former students share insights on the impact of Dr. Henry`s research in the field of magnetism, low temperature physics, and solid state physics; his influence on students as an educator; and his character, intellect and ingenuity, and passion for learning and teaching. They share a glimpse of the environment and times that molded him as a man, and the circumstances under which he made his great achievements despite the many challenges he faced.

  5. Nature Macmillan Publishers Ltd 1998 consumption of surface materials cannot be ruled out, but the

    E-Print Network [OSTI]

    Zeldov, Eli

    Nature © Macmillan Publishers Ltd 1998 8 consumption of surface materials cannot be ruled out less pervasive among the dark wedge bands discussed here, suggesting that heat transfer from,9 , as well as interior models based on gravitational data derived from Doppler tracking of the Galileo

  6. Development of Advanced Wear and Corrosion Resistant Systems Through Laser Surface Alloying and Materials Simulations

    SciTech Connect (OSTI)

    R. P. Martukanitz and S. Babu

    2007-05-03T23:59:59.000Z

    Laser surfacing in the form of cladding, alloying, and modifications are gaining widespread use because of its ability to provide high deposition rates, low thermal distortion, and refined microstructure due to high solidification rates. Because of these advantages, laser surface alloying is considered a prime candidate for producing ultra-hard coatings through the establishment or in situ formation of composite structures. Therefore, a program was conducted by the Applied Research Laboratory, Pennsylvania State University and Oak Ridge National Laboratory to develop the scientific and engineering basis for performing laser-based surface modifications involving the addition of hard particles, such as carbides, borides, and nitrides, within a metallic matrix for improved wear, fatigue, creep, and corrosion resistance. This has involved the development of advanced laser processing and simulation techniques, along with the refinement and application of these techniques for predicting and selecting materials and processing parameters for the creation of new surfaces having improved properties over current coating technologies. This program has also resulted in the formulation of process and material simulation tools capable of examining the potential for the formation and retention of composite coatings and deposits produced using laser processing techniques, as well as positive laboratory demonstrations in producing these coatings. In conjunction with the process simulation techniques, the application of computational thermodynamic and kinetic models to design laser surface alloying materials was demonstrated and resulted in a vast improvement in the formulation of materials used for producing composite coatings. The methodology was used to identify materials and to selectively modify microstructures for increasing hardness of deposits produced by the laser surface alloying process. Computational thermodynamic calculations indicated that it was possible to induce the precipitation of titanium carbonitrides during laser surface alloying provided there was sufficient amount of dissolved titanium, carbon, and nitrogen in the liquid steel. This was confirmed experimentally by using a powder mixture of 431-martensitic steel, titanium carbide powder, and nitrogen shielding, during laser deposition to produce deposits exhibiting relatively high hardness (average surface hardness of 724 HV). The same approach was extended to direct diode laser processing and similar microstructures were attained. The above analysis was extended to develop an in-situ precipitation of Ti(CN) during laser deposition. The Ti addition was achieving by mixing the 431 martensitic steel powders with ferro-titanium. The dissolution of nitrogen was achieved by using 100% nitrogen shielding gas, which was indicated by thermodynamic analysis. Demonstrations were also conducted utilizing the tools developed during the program and resulted in several viable composite coating systems being identified. This included the use of TiC and ferro-titanium in martensitic-grade stainless steel matrix material with and without the use of active N2 shielding gas, WC hard particles in a martensitic-grade stainless steel matrix material, WC and BN in a nickel-based matrix material, and WC in highly alloyed iron-based matrix. Although these demonstrations indicated the potential of forming composite coatings, in certain instances, the intended industrial applications involved unique requirements, such as coating of internal surfaces, which hindered the full development of the improved coating technology. However, it is believed that the addition of common hard particles, such as WC or TiC, to matrix material representing martensitic grades of stainless steel offer opportunities for improved performance at relatively low material cost.

  7. Spectral dependence of the magnetic modulation of surface plasmon polaritons in noble/ferromagnetic/noble metal films

    E-Print Network [OSTI]

    Temnov, Vasily V.

    The magnetic field is an interesting candidate for the development of active plasmonic devices as it is able to modify the surface plasmon polariton (SPP) wave vector. Both real and imaginary parts of the SPP wave vector ...

  8. Nuclear magnetic resonance-based study of ordered layering on the surface of alumina nanoparticles in water

    E-Print Network [OSTI]

    Gerardi, Craig

    Layering of water molecules on the surface of alumina nanoparticles in an alumina/water nanofluid is studied using nuclear magnetic resonance (NMR). The data suggest that a thin ordered layer ( ? 1.4?nm) of water molecules ...

  9. Fresnel versus Kummer surfaces: geometrical optics in dispersionless linear (meta)materials and vacuum

    E-Print Network [OSTI]

    Alberto Favaro; Friedrich W. Hehl

    2014-01-16T23:59:59.000Z

    Geometrical optics describes, with good accuracy, the propagation of high-frequency plane waves through an electromagnetic medium. Under such approximation, the behaviour of the electromagnetic fields is characterised by just three quantities: the temporal frequency $\\omega$, the spatial wave (co)vector $k$, and the polarisation (co)vector $a$. Numerous key properties of a given optical medium are determined by the Fresnel surface, which is the visual counterpart of the equation relating $\\omega$ and $k$. For instance, the propagation of electromagnetic waves in a uniaxial crystal, such as calcite, is represented by two light-cones. Kummer, whilst analysing quadratic line complexes as models for light rays in an optical apparatus, discovered in the framework of projective geometry a quartic surface that is linked to the Fresnel one. Given an arbitrary dispersionless linear (meta)material or vacuum, we aim to establish whether the resulting Fresnel surface is equivalent to, or is more general than, a Kummer surface.

  10. Laser Measurement of SAM Bulk and Surface Wave Amplitudes for Material Microstructure Analysis

    SciTech Connect (OSTI)

    Ken L. Telschow; Chiaki Miyasaka; David L. Cottle

    2005-07-01T23:59:59.000Z

    Scanning Acoustic Microscopy (SAM) at ultra high frequencies has proven to be a useful tool for investigating materials on the scale of individual grains. This technique is normally performed in a reflection mode from one side of a sample surface. Information about the generation and transmission of bulk acoustic waves into the material is inferred from the reflection signal amplitude. We present an adaptation to the SAM method whereby the acoustic bulk waves are directly visualized through laser acoustic detection. Ultrasonic waves were emitted from a nominal 200 MHz point focus acoustic lens into a thin silicon plate (thickness 75ìm) coupled with distilled water. A scanned laser beam detected the bulk and surface acoustic waves at the opposite surface of the thin silicon plate. Distinct amplitude patterns exhibiting the expected symmetry for Silicon were observed that alter in predictable ways as the acoustic focal point was moved throughout the plate. Predictions of the acoustic wave fields generated by the acoustic lens within and at the surface of the Silicon are being investigated through the angular spectrum of plane waves approach. Results shall be presented for plates with (100) and (111) orientations followed by discussion of applications of the technique for material microstructure analysis.

  11. Maximization of No-Load Flux Density in Surface Mounted Permanent Magnet Motors Frdric DUBAS, Christophe ESPANET & Abdellatif MIRAOUI.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Maximization of No-Load Flux Density in Surface Mounted Permanent Magnet Motors Frédéric DUBAS, Christophe ESPANET & Abdellatif MIRAOUI. Research Laboratory in Electronics, Electrical engineering expression of the optimal thickness of the magnet which make it possible to maximize the no-load flux density

  12. High magnetic field ohmically decoupled non-contact technology

    DOE Patents [OSTI]

    Wilgen, John (Oak Ridge, TN) [Oak Ridge, TN; Kisner, Roger (Knoxville, TN) [Knoxville, TN; Ludtka, Gerard (Oak Ridge, TN) [Oak Ridge, TN; Ludtka, Gail (Oak Ridge, TN) [Oak Ridge, TN; Jaramillo, Roger (Knoxville, TN) [Knoxville, TN

    2009-05-19T23:59:59.000Z

    Methods and apparatus are described for high magnetic field ohmically decoupled non-contact treatment of conductive materials in a high magnetic field. A method includes applying a high magnetic field to at least a portion of a conductive material; and applying an inductive magnetic field to at least a fraction of the conductive material to induce a surface current within the fraction of the conductive material, the surface current generating a substantially bi-directional force that defines a vibration. The high magnetic field and the inductive magnetic field are substantially confocal, the fraction of the conductive material is located within the portion of the conductive material and ohmic heating from the surface current is ohmically decoupled from the vibration. An apparatus includes a high magnetic field coil defining an applied high magnetic field; an inductive magnetic field coil coupled to the high magnetic field coil, the inductive magnetic field coil defining an applied inductive magnetic field; and a processing zone located within both the applied high magnetic field and the applied inductive magnetic field. The high magnetic field and the inductive magnetic field are substantially confocal, and ohmic heating of a conductive material located in the processing zone is ohmically decoupled from a vibration of the conductive material.

  13. Influence of substrate material, orientation, and surface termination on GaN nanowire growth

    SciTech Connect (OSTI)

    Schuster, Fabian, E-mail: Fabian.Schuster@wsi.tum.de; Weiszer, Saskia; Hetzl, Martin; Winnerl, Andrea; Garrido, Jose A.; Stutzmann, Martin [Walter Schottky Institut and Physics Department, Technische Universität München, Am Coulombwall 4, 85748 Garching (Germany)

    2014-08-07T23:59:59.000Z

    In this work, we investigate the fundamental role of the substrate material, surface orientation, and termination on GaN nanowire (NW) nucleation and growth. First of all, the use of a patterned a-Si/diamond substrate confirms that NW shape and dimension are mainly determined by the applied growth conditions instead of the nature of the substrate. More important is the surface orientation as it defines growth direction and epitaxial relationship towards the GaN NWs, where both (111) and (100) surfaces yield NW growth for equivalent growth conditions. (110) substrates are found to be not suited for NW growth. Finally, the surface termination of diamond is demonstrated to survive the employed growth conditions and, therefore, to affect the nucleation of nanowires and the electronic properties of the heterointerface by its surface dipoles. This difference in nucleation is exploited as an alternative approach for selective area growth without deposition of a foreign mask material, which might also be transferable to other substrates.

  14. Magnetic material in mean-field dynamos driven by small scale helical flows

    E-Print Network [OSTI]

    Giesecke, Andre; Gerbeth, Gunter

    2014-01-01T23:59:59.000Z

    We perform kinematic simulations of dynamo action driven by a helical small scale flow of a conducting fluid in order to deduce mean-field properties of the combined induction action of small scale eddies. We examine two different flow patterns in the style of the G.O. Roberts flow but with a mean vertical component and with internal fixtures that are modelled by regions with vanishing flow. These fixtures represent either rods that lie in the center of individual eddies, or internal dividing walls that provide a separation of the eddies from each other. The fixtures can be made of magnetic material with a relative permeability larger than one which can alter the dynamo behavior. The investigations are motivated by the widely unknown induction effects of the forced helical flow that is used in the core of liquid sodium cooled fast reactors, and from the key role of soft iron impellers in the von-K\\'arm\\'an-Sodium (VKS) dynamo. For both examined flow configurations the consideration of magnetic material within...

  15. Sub-surface characterization and three dimensional profiling of semiconductors by magnetic resonance force microscopy

    SciTech Connect (OSTI)

    Hammel, P.C.; Moore, G.; Roukes, M.; Zhenyong Zhang

    1996-10-01T23:59:59.000Z

    This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project successfully developed a magnetic resonance force microscope (MRFM) instrument to mechanically detect magnetic resonance signals. This technique provides an intrinsically subsurface, chemical-species-specific probe of structure, constituent density and other properties of materials. As in conventional magnetic resonance imaging (MRI), an applied magnetic field gradient selects a well defined volume of the sample for study. However mechanical detection allows much greater sensitivity, and this in turn allows the reduction of the size of the minimum resolvable volume. This requires building an instrument designed to achieve nanometer-scale resolution at buried semiconductor interfaces. High-resolution, three-dimensional depth profiling of semiconductors is critical in the development and fabrication of semiconductor devices. Currently, there is no capability for direct, high-resolution observation and characterization of dopant density, and other critical features of semiconductors. The successful development of MRFM in conjunction with modifications to improve resolution will enable for the first time detailed structural and electronic studies in doped semiconductors and multilayered nanoelectronic devices, greatly accelerating the current pace of research and development.

  16. Plasma density accumulation on a conical surface for diffusion along a diverging magnetic field

    SciTech Connect (OSTI)

    Saha, S. K.; Chowdhury, S.; Janaki, M. S.; Ghosh, A.; Hui, A. K.; Raychaudhuri, S. [Saha Institute of Nuclear Physics, Plasma Physics Division, 1/AF Bidhannagar, Kolkata 700064 (India)] [Saha Institute of Nuclear Physics, Plasma Physics Division, 1/AF Bidhannagar, Kolkata 700064 (India)

    2014-04-15T23:59:59.000Z

    Two-dimensional (2-D) density and potential measurements have been carried out for plasma diffusing through an aperture in a diverging magnetic field. The radial density profile near the source is peaked on the axis but gradually evolves into a hollow profile away from the source. We observe a slow increase of the peak density along a hollow conical surface and correlate with the 2-D potential measurement reported earlier. It is also shown that the formation of 2-D structures with similar features are observed whenever plasma is allowed to diffuse through a physical aperture in such diverging magnetic field configuration, with or without the presence of electric double layer, i.e., the phenomenon is generic in nature.

  17. Solar-wind protons and heavy ions sputtering of lunar surface materials A.F. Barghouty a,

    E-Print Network [OSTI]

    Solar-wind protons and heavy ions sputtering of lunar surface materials A.F. Barghouty a, , F Available online 21 December 2010 Keywords: Solar wind sputtering Lunar regolith KREEP soil Potential a c t Lunar surface materials are exposed to $1 keV/amu solar-wind protons and heavy ions on almost

  18. Fresnel versus Kummer surfaces: geometrical optics in dispersionless linear (meta)materials and vacuum

    E-Print Network [OSTI]

    Favaro, Alberto

    2014-01-01T23:59:59.000Z

    Geometrical optics describes, with good accuracy, the propagation of high-frequency plane waves through an electromagnetic medium. Under such approximation, the behaviour of the electromagnetic fields is characterised by just three quantities: the temporal frequency $\\omega$, the spatial wave (co)vector $k$, and the polarisation (co)vector $a$. Numerous key properties of a given optical medium are determined by the Fresnel surface, which is the visual counterpart of the equation relating $\\omega$ and $k$. For instance, the propagation of electromagnetic waves in a uniaxial crystal, such as calcite, is represented by two light-cones. Kummer, whilst analysing quadratic line complexes as models for light rays in an optical apparatus, discovered in the framework of projective geometry a quartic surface that is linked to the Fresnel one. Given an arbitrary dispersionless linear (meta)material or vacuum, we aim to establish whether the resulting Fresnel surface is equivalent to, or is more general than, a Kummer su...

  19. Effect of ion excape velocity and conversion surface material on H- production

    SciTech Connect (OSTI)

    Johnson, Kenneth F [Los Alamos National Laboratory; Tarvainen, Olli A [Los Alamos National Laboratory; Geros, E. [Los Alamos National Laboratory; Stelzer, J. [Los Alamos National Laboratory; Rouleau, G. [Los Alamos National Laboratory; Kalvas, T. [UNIV OF JYVASKYLA; Komppula, J. [UNIV OF JYASKYLA; Carmichael, J. [ORNL

    2010-10-05T23:59:59.000Z

    According to generally accepted models surface production of negative ions depends on ion escape velocity and work function of the surface. We have conducted an experimental study addressing the role of the ion escape velocity on H{sup -} production. A converter-type ion source at Los Alamos Neutron Science Center was employed for the experiment. The ion escape velocity was changed by varying the bias voltage of the converter electrode. It was observed that due to enhanced stripping of H{sup -} no direct gain of extracted beam current can be achieved by increasing the converter voltage. At the same time the conversion efficiency of H{sup -} was observed to vary with converter voltage and follow the existing theories in qualitative manner. We discuss the role of surface material on H{sup -} formation probability and present calculations predicting relative H{sup -} yields from different cesiated surfaces. These calculations are compared with experimental observations from different types of H{sup -} ion sources. The effects caused by varying cesium coverage are also discussed. Finally, we present a novel idea of utilizing materials exhibiting so-called negative electron affinity in H{sup -}/D{sup -} production under UV-light exposure.

  20. Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label for large aspect ratio

    E-Print Network [OSTI]

    Isliker, Heinz

    Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label, 056114 (2012); 10.1063/1.3694842 Driving toroidally asymmetric current through the tokamak scrape-off in toroidal geometry: An exact analytical flux surface label for large aspect ratio N. Kallinikos, H. Isliker

  1. Rare?Earth?Free Permanent Magnets for Electrical Vehicle Motors and Wind Turbine Generators: Hexagonal Symmetry Based Materials Systems Mn?Bi and M?type Hexaferrite

    SciTech Connect (OSTI)

    Hong, Yang-Ki [University of Alabama] [University of Alabama; Haskew, Timothy [University of Alabama] [University of Alabama; Myryasov, Oleg [University of Alabama] [University of Alabama; Jin, Sungho [University of California San Diego] [University of California San Diego; Berkowitz, Ami [University of California San Diego] [University of California San Diego

    2014-06-05T23:59:59.000Z

    The research we conducted focuses on the rare-earth (RE)-free permanent magnet by modeling, simulating, and synthesizing exchange coupled two-phase (hard/soft) RE-free core-shell nano-structured magnet. The RE-free magnets are made of magnetically hard core materials (high anisotropy materials including Mn-Bi-X and M-type hexaferrite) coated by soft shell materials (high magnetization materials including Fe-Co or Co). Therefore, our research helps understand the exchange coupling conditions of the core/shell magnets, interface exchange behavior between core and shell materials, formation mechanism of core/shell structures, stability conditions of core and shell materials, etc.

  2. Development of Apple Workgroup Cluster and Parallel Computing for Phase Field Model of Magnetic Materials

    E-Print Network [OSTI]

    Huang, Yongxin

    2010-01-16T23:59:59.000Z

    Micromagnetic modeling numerically solves magnetization evolution equation to process magnetic domain analysis, which helps to understand the macroscopic magnetic properties of ferromagnets. To apply this method in simulation of magnetostrictive...

  3. Magnetic infrasound sensor

    DOE Patents [OSTI]

    Mueller, Fred M. (Los Alamos, NM); Bronisz, Lawrence (Los Alamos, NM); Grube, Holger (Los Alamos, NM); Nelson, David C. (Santa Fe, NM); Mace, Jonathan L. (Los Alamos, NM)

    2006-11-14T23:59:59.000Z

    A magnetic infrasound sensor is produced by constraining a permanent magnet inside a magnetic potential well above the surface of superconducting material. The magnetic infrasound sensor measures the position or movement of the permanent magnet within the magnetic potential well, and interprets the measurements. Infrasound sources can be located and characterized by combining the measurements from one or more infrasound sensors. The magnetic infrasound sensor can be tuned to match infrasound source types, resulting in better signal-to-noise ratio. The present invention can operate in frequency modulation mode to improve sensitivity and signal-to-noise ratio. In an alternate construction, the superconductor can be levitated over a magnet or magnets. The system can also be driven, so that time resolved perturbations are sensed, resulting in a frequency modulation version with improved sensitivity and signal-to-noise ratio.

  4. Magnetic Processing – A Pervasive Energy Efficient Technology for Next Generation Materials for Aerospace and Specialty Steel Markets

    SciTech Connect (OSTI)

    Mackiewicz-Ludtka, G.; Ludtka, G.M.; Ray, P. (Carpenter Technologies, Inc.); Magee, J. (Carpenter Technologies, Inc.)

    2010-09-10T23:59:59.000Z

    Thermomagnetic Magnetic Processing is an exceptionally fertile, pervasive and cross-cutting technology that is just now being recognized by several major industry leaders for its significant potential to increase energy efficiency and materials performance for a myriad of energy intensive industries in a variety of areas and applications. ORNL has pioneered the use and development of large magnetic fields in thermomagnetically processing (T-MP) materials for altering materials phase equilibria and transformation kinetics. ORNL has discovered that using magnetic fields, we can produce unique materials responses. T-MP can produce unique phase stabilities & microstructures with improved materials performance for structural and functional applications not achieved with traditional processing techniques. These results suggest that there are unprecedented opportunities to produce significantly enhanced materials properties via atomistic level (nano-) microstructural control and manipulation. ORNL (in addition to others) have shown that grain boundary chemistry and precipitation kinetics are also affected by large magnetic fields. This CRADA has taken advantage of ORNL’s unique, custom-designed thermo-magnetic, 9 Tesla superconducting magnet facility that enables rapid heating and cooling of metallic components within the magnet bore; as well as ORNL’s expertise in high magnetic field (HMF) research. Carpenter Technologies, Corp., is a a US-based industrial company, that provides enhanced performance alloys for the Aerospace and Specialty Steel products. In this CRADA, Carpenter Technologies, Corp., is focusing on applying ORNL’s Thermomagnetic Magnetic Processing (TMP) technology to improve their current and future proprietary materials’ product performance and open up new markets for their Aerospace and Specialty Steel products. Unprecedented mechanical property performance improvements have been demonstrated for a high strength bainitic alloy industrial/commercial alloy that is envisioned to provide the potential for new markets for this alloy. These thermomechanical processing results provide these alloys with a major breakthrough demonstrating that simultaneous improvements in yield strength and ductility are achieved: 12 %, 10%, 13%, and 22% increases in yield strength, elongation, reduction-in-area, and impact energy respectively. In addition, TMP appears to overcome detrimental chemical homogeneity impacts on uniform microstructure evolution.

  5. Magnetic fusion energy plasma interactive and high heat flux components. Volume I. Technical assessment of the critical issues and problem areas in the plasma materials interaction field

    SciTech Connect (OSTI)

    Conn, R.W.; Gauster, W.B.; Heifetz, D.; Marmar, E.; Wilson, K.L. (eds.)

    1984-01-01T23:59:59.000Z

    A technical assessment of the critical issues and problem areas in the field of plasma materials interactions (PMI) in magnetic fusion devices shows these problems to be central for near-term experiments, for intermediate-range reactor devices including D-T burning physics experiments, and for long-term reactor machines. Critical technical issues are ones central to understanding and successful operation of existing and near-term experiments/reactors or devices of great importance for the long run, i.e., ones which will require an extensive, long-term development effort and thus should receive attention now. Four subgroups were formed to assess the critical PMI issues along four major lines: (1) PMI and plasma confinement physics experiments; (2) plasma-edge modelling and theory; (3) surface physics; and (4) materials technology for in-vessel components and the first wall. The report which follows is divided into four major sections, one for each of these topics.

  6. An efficient plate heater with uniform surface temperature engineered with effective thermal materials

    E-Print Network [OSTI]

    Liu, Yichao; He, Sailing; Ma, Yungui

    2014-01-01T23:59:59.000Z

    Extended from its electromagnetic counterpart, transformation thermodynamics applied to thermal conduction equations can map a virtual geometry into a physical thermal medium, realizing the manipulation of heat flux with almost arbitrarily desired diffusion paths, which provides unprecedented opportunities to create thermal devices unconceivable or deemed impossible before. In this work we employ this technique to design an efficient plate heater that can transiently achieve a large surface of uniform temperature powered by a small thermal source. As opposed to the traditional approach of relying on the deployment of a resistor network, our approach fully takes advantage of an advanced functional material system to guide the heat flux to achieve the desired temperature heating profile. A different set of material parameters for the transformed device has been developed, offering the parametric freedom for practical applications. As a proof of concept, the proposed devices are implemented with engineered therm...

  7. Synthesis of bulk FeHfBO soft magnetic materials and its loss characterization at megahertz frequency

    SciTech Connect (OSTI)

    Zhou Yang; Kou Xiaoming; Warsi Muhammad, Asif; Lin Shuo; Harris, Brendan S.; Parsons, Paul E.; Xiao, John Q. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Mu Mingkai; Lee, Fred C. [Center for Power Electronics System, Virginia Polytechnic and State University, Blacksburg, Virginia 24060 (United States); Zhu Hao [Spectrum Magnetics LLC, Wilmington, Delaware 19804 (United States)

    2013-05-07T23:59:59.000Z

    Magnetic core materials with low loss, high saturation magnetization, large permeability, and operating frequency above 1 MHz are in high demands for the next generation of miniaturized power electronics. Amorphous FeHfB ribbons with thickness around 20 {mu}m have been fabricated through melt-spinning. Different heat treatments were performed on the FeHfB ribbons, and the relations among heat treatments, microstructure, and magnetic properties have been explored. Properties such as coercivity (H{sub c}) of 2.0 Oe and saturation magnetic flux density (B{sub S}) of 1.2 T have been achieved in samples with exchange coupling. The losses can be minimized by balancing the hysteretic and eddy current losses and can be further reduced with additional magnetic field annealing. At 5 MHz with peak magnetic flux density of 20 mT, the materials show core losses comparable to the best ferrites, but with higher permeability value of about 200 and superior saturation induction of more than 1 T.

  8. A Study to Verify the Material Surface Concept of Water Table by Examining Analytical and Numerical Models.

    E-Print Network [OSTI]

    Dadi, Sireesh Kumar

    2011-10-21T23:59:59.000Z

    The highly nonlinear nature of unsaturated flow results in different ways to approximate the delayed or instantaneous movement of the water table. In nearly all the approaches, the water table is conceptually treated as a “material surface...

  9. Theoretical Modelling of Magnetic Refrigeration Materials A PhD studentship is available in the Warwick Theory Group on a theoretical/computational PhD project

    E-Print Network [OSTI]

    Low, Robert

    Theoretical Modelling of Magnetic Refrigeration Materials A PhD studentship is available in the Warwick Theory Group on a theoretical/computational PhD project on the modelling of magnetic refrigeration or air, or for very low temperatures, helium. Therefore, magnetic refrigeration is environmentally

  10. A Review of Removable Surface Contamination on Radioactive Materials Transportation Containers

    SciTech Connect (OSTI)

    Kennedy, Jr, W. E.; Watson, E. C.; Murphy, D. W.; Harrer, B. J.; Harty, R.; Aldrich, J. M.

    1981-05-01T23:59:59.000Z

    This report contains the results of a study sponsored by the U.S. Nuclear Regulatory Commission (NRC) of removable surface contamination on radioactive materials transportation containers. The purpose of the study is to provide information to the NRC during their review of existing regulations. Data was obtained from both industry and literature on three major topics: 1) radiation doses, 2) economic costs, and 3) contamination frequencies. Containers for four categories of radioactive materials are considered including radiopharmaceuticals, industrial sources, nuclear fuel cycle materials, and low-level radioactive waste. Assumptions made in this study use current information to obtain realistic yet conservative estimates of radiation dose and economic costs. Collective and individual radiation doses are presented for each container category on a per container basis. Total doses, to workers and the public, are also presented for spent fuel cask and low-level waste drum decontamination. Estimates of the additional economic costs incurred by lowering current limits by factors of 10 and 100 are presented. Current contamination levels for each category of container are estimated from the data collected. The information contained in this report is designed to be useful to the NRC in preparing their recommendations for new regulations.

  11. Effective flow surface of porous materials with two populations of voids under internal pressure: I. a GTN model

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ). Such a microstructure is typical of the highly irradiated uranium dioxide (UO2), a nuclear fuel commonly used in nuclear several studies on the mechanical behavior of highly irradiated nuclear fuels at different scales (Vincent to the effective plastic flow surface of a bi-porous material saturated by a fluid. The material under

  12. Maximizing Hysteretic Losses in Magnetic Ferrite Nanoparticles via Model-Driven Synthesis and Materials Optimization

    E-Print Network [OSTI]

    Chen, Ritchie

    This article develops a set of design guidelines for maximizing heat dissipation characteristics of magnetic ferrite MFe[subscript 2]O[subscript 4] (M = Mn, Fe, Co) nanoparticles in alternating magnetic fields. Using ...

  13. Thermal and high magnetic field treatment of materials and associated apparatus

    DOE Patents [OSTI]

    Kisner, Roger A.; Wilgen, John B.; Ludtka, Gerard M.; Jaramillo, Roger A.; Mackiewicz-Ludtka, Gail

    2010-06-29T23:59:59.000Z

    An apparatus and method for altering characteristics, such as can include structural, magnetic, electrical, optical or acoustical characteristics, of an electrically-conductive workpiece utilizes a magnetic field within which the workpiece is positionable and schemes for thermally treating the workpiece by heating or cooling techniques in conjunction with the generated magnetic field so that the characteristics of the workpiece are effected by both the generated magnetic field and the thermal treatment of the workpiece.

  14. Thermal and high magnetic field treatment of materials and associated apparatus

    DOE Patents [OSTI]

    Kisner, Roger A.; Wilgen, John B.; Ludtka, Gerard M.; Jaramillo, Roger A.; Mackiewicz-Ludtka, Gail

    2007-01-09T23:59:59.000Z

    An apparatus and method for altering characteristics, such as can include structural, magnetic, electrical, optical or acoustical characteristics, of an electrically-conductive workpiece utilizes a magnetic field within which the workpiece is positionable and schemes for thermally treating the workpiece by heating or cooling techniques in conjunction with the generated magnetic field so that the characteristics of the workpiece are effected by both the generated magnetic field and the thermal treatment of the workpiece.

  15. Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance

    SciTech Connect (OSTI)

    Kong, Zueqian

    2010-03-15T23:59:59.000Z

    Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

  16. Towards an electro-magnetic field separation of deposited material implemented in an ion beam sputter process

    SciTech Connect (OSTI)

    Malobabic, Sina; Jupe, Marco; Ristau, Detlev [Laser Component Department, Laser Zentrum Hannover e.V., Hollerithallee 8, 30149 Hannover (Germany) [Laser Component Department, Laser Zentrum Hannover e.V., Hollerithallee 8, 30149 Hannover (Germany); Quest: Centre of Quantum Engineering and Space-Time Research, Leibniz Universitaet Hannover, Hannover (Germany)

    2013-06-03T23:59:59.000Z

    Nowadays, Ion Beam Sputter (IBS) processes are very well optimized on an empirical basis. To achieve further progresses, a modification of the IBS process by guiding the coating material using an axial magnetic field and an additional electrical field has been studied. The electro-magnetic (EM) field leads to a significant change in plasma properties and deposition rate distributions, whereas an increase in deposition rate along the centerline of the axial EM field around 150% was observed. These fundamental studies on the prototype are the basis for the development of an applicable and workable design of a separation device.

  17. Transitions from near-surface to interior redox upon lithiation in conversion electrode materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    He, Kai; Xin, Huolin L.; Zhao, Kejie; Yu, Xiqian; Norlund, Dennis; Weng, Tsu-Chien; Li, Jing; Jiang, Yi; Cadigan, Christopher A.; Richards, Ryan M.; et al

    2015-02-11T23:59:59.000Z

    Nanoparticle electrodes in lithium-ion batteries have both near-surface and interior contributions to their redox capacity, each with distinct rate capabilities. Using combined electron microscopy, synchrotron X-ray methods and ab initio calculations, we have investigated the lithiation pathways that occur in NiO electrodes. We find that the near-surface electroactive (Ni²??Ni?) sites saturated very quickly, and then encounter unexpected difficulty in propagating the phase transition into the electrode (referred to as a “shrinking-core” mode). However, the interior capacity for Ni²??Ni? can be accessed efficiently following the nucleation of lithiation “fingers” which propagate into the sample bulk, but only after a certain incubationmore »time. Our microstructural observations of the transition from a slow shrinking-core mode to a faster lithiation finger mode corroborate with synchrotron characterization of large-format batteries, and can be rationalized by stress effects on transport at high-rate discharge. The finite incubation time of the lithiation fingers sets the intrinsic limitation for the rate capability (and thus the power) of NiO for electrochemical energy storage devices. The present work unravels the link between the nanoscale reaction pathways and the C-rate-dependent capacity loss, and provides guidance for the further design of battery materials that favors high C-rate charging.« less

  18. Transitions from near-surface to interior redox upon lithiation in conversion electrode materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    He, Kai [Brookhaven National Lab. (BNL), Upton, NY (United States); Xin, Huolin L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhao, Kejie [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Yu, Xiqian [Brookhaven National Lab. (BNL), Upton, NY (United States); Norlund, Dennis [SLAC National Accelerator Lab., Menlo Park, CA (United States); Weng, Tsu-Chien [SLAC National Accelerator Lab., Menlo Park, CA (United States); Li, Jing [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Jiang, Yi [Cornell Univ., Ithaca, NY (United States); Cadigan, Christopher A. [Colorado School of Mines, Golden, CO (United States); Richards, Ryan M. [Colorado School of Mines, Golden, CO (United States); Doeff, Marca M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yang, Xiao-Qing [Brookhaven National Lab. (BNL), Upton, NY (United States); Stach, Eric A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Li, Ju [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Lin, Feng [Colorado School of Mines, Golden, CO (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Su, Dong [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States)

    2015-02-11T23:59:59.000Z

    Nanoparticle electrodes in lithium-ion batteries have both near-surface and interior contributions to their redox capacity, each with distinct rate capabilities. Using combined electron microscopy, synchrotron X-ray methods and ab initio calculations, we have investigated the lithiation pathways that occur in NiO electrodes. We find that the near-surface electroactive (Ni²??Ni?) sites saturated very quickly, and then encounter unexpected difficulty in propagating the phase transition into the electrode (referred to as a “shrinking-core” mode). However, the interior capacity for Ni²??Ni? can be accessed efficiently following the nucleation of lithiation “fingers” which propagate into the sample bulk, but only after a certain incubation time. Our microstructural observations of the transition from a slow shrinking-core mode to a faster lithiation finger mode corroborate with synchrotron characterization of large-format batteries, and can be rationalized by stress effects on transport at high-rate discharge. The finite incubation time of the lithiation fingers sets the intrinsic limitation for the rate capability (and thus the power) of NiO for electrochemical energy storage devices. The present work unravels the link between the nanoscale reaction pathways and the C-rate-dependent capacity loss, and provides guidance for the further design of battery materials that favors high C-rate charging.

  19. Development of Superconducting Materials for Use in Magnet Applications: Nb3Sn Flux Pinning and Bi-2212 Magnetic Texturing 

    E-Print Network [OSTI]

    Rahmani, David G.

    2010-07-14T23:59:59.000Z

    as round wires are presented and discussed. Processes were developed to increase flux pinning in Nb3Sn by utilizing powder metallurgy techniques to introduce a heterogeneously homogenous distribution of nanoscale inclusions of candidate materials in Nb rod...

  20. Development of Superconducting Materials for Use in Magnet Applications: Nb3Sn Flux Pinning and Bi-2212 Magnetic Texturing

    E-Print Network [OSTI]

    Rahmani, David G.

    2010-07-14T23:59:59.000Z

    as round wires are presented and discussed. Processes were developed to increase flux pinning in Nb3Sn by utilizing powder metallurgy techniques to introduce a heterogeneously homogenous distribution of nanoscale inclusions of candidate materials in Nb rod...

  1. Journal of Magnetism and Magnetic Materials 256 (2003) 4145 Influence of the initial temperature on the thermal

    E-Print Network [OSTI]

    Schumann, Rolf

    2003-01-01T23:59:59.000Z

    on the thermal remagnetization of SmCo5 sintered magnets L. Jahna , V. Ivanovb , R. Schumannc, *, M. Loewenhaupta-demagnetization at the initial temperature T0 followed by heating. The TR is especially large for well-aligned sintered SmCo5 of the coercivity. We present a systematical study on the influence of the initial temperature T0 on the TR of SmCo5

  2. Permanent-magnet multipole with adjustable strength

    DOE Patents [OSTI]

    Halbach, K.

    1982-09-20T23:59:59.000Z

    Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling there between. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

  3. Permanent magnet multipole with adjustable strength

    DOE Patents [OSTI]

    Halbach, Klaus (Berkeley, CA)

    1985-01-01T23:59:59.000Z

    Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling therebetween. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

  4. Influence of dipolar collective effects on coercivity and demagnetizing factors in hard magnetic materials

    E-Print Network [OSTI]

    Dobrynin, Alexey

    perpendicular recording media and high- performance sintered magnets, such as NdFeB and SmCo5. In such systems

  5. Corrosion in Supercritical carbon Dioxide: Materials, Environmental Purity, Surface Treatments, and Flow Issues

    SciTech Connect (OSTI)

    Sridharan, Kumar; Anderson, Mark

    2013-12-10T23:59:59.000Z

    The supercritical CO{sub 2} Brayton cycle is gaining importance for power conversion in the Generation IV fast reactor system because of its high conversion efficiencies. When used in conjunction with a sodium fast reactor, the supercritical CO{sub 2} cycle offers additional safety advantages by eliminating potential sodium-water interactions that may occur in a steam cycle. In power conversion systems for Generation IV fast reactors, supercritical CO{sub 2} temperatures could be in the range of 30°C to 650°C, depending on the specific component in the system. Materials corrosion primarily at high temperatures will be an important issue. Therefore, the corrosion performance limits for materials at various temperatures must be established. The proposed research will have four objectives centered on addressing corrosion issues in a high-temperature supercritical CO{sub 2} environment: Task 1: Evaluation of corrosion performance of candidate alloys in high-purity supercritical CO{sub 2}: The following alloys will be tested: Ferritic-martensitic Steels NF616 and HCM12A, austenitic alloys Incoloy 800H and 347 stainless steel, and two advanced concept alloys, AFA (alumina forming austenitic) steel and MA754. Supercritical CO{sub 2} testing will be performed at 450°C, 550°C, and 650°C at a pressure of 20 MPa, in a test facility that is already in place at the proposing university. High purity CO{sub 2} (99.9998%) will be used for these tests. Task 2: Investigation of the effects of CO, H{sub 2}O, and O{sub 2} impurities in supercritical CO{sub 2} on corrosion: Impurities that will inevitably present in the CO{sub 2} will play a critical role in dictating the extent of corrosion and corrosion mechanisms. These effects must be understood to identify the level of CO{sub 2} chemistry control needed to maintain sufficient levels of purity to manage corrosion. The individual effects of important impurities CO, H{sub 2}O, and O{sub 2} will be investigated by adding them separately to high purity CO{sub 2}. Task 3: Evaluation of surface treatments on the corrosion performance of alloys in supercritical CO{sub 2}: Surface treatments can be very beneficial in improving corrosion resistance. Shot peening and yttrium and aluminum surface treatments will be investigated. Shot peening refines the surface grain sizes and promotes protective Cr-oxide layer formation. Both yttrium and aluminum form highly stable oxide layers (Y{sub 2}O{sub 3} and Al{sub 2}O{sub 3}), which can get incorporated in the growing Fe-oxide layer to form an impervious complex oxide to enhance corrosion resistance. Task 4: Study of flow-assisted corrosion of select alloys in supercritical CO{sub 2} under a selected set of test conditions: To study the effects of flow-assisted corrosion, tests will be conducted in a supercritical CO{sub 2} flow loop. An existing facility used for supercritical water flow studies at the proposing university will be modified for use in this task. The system is capable of flow velocities up to 10 m/s and can operate at temperatures and pressures of up to 650°C and 20 MPa, respectively. All above tasks will be performed in conjunction with detailed materials characterization and analysis using scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS), x-ray diffraction (XRD), Auger electron spectroscopy (AES) techniques, and weight change measurements. Inlet and outlet gas compositions will be monitored using gas chromatography-mass spectrometry (GCMS).

  6. Surface reconstruction and chemical evolution of stoichiometric layered cathode materials for lithium-ion batteries

    E-Print Network [OSTI]

    Lin, Feng

    2014-01-01T23:59:59.000Z

    O 2 Cathode Material in Lithium Ion Batteries. Adv. Energysolvent decomposition in lithium ion batteries: first-Cathode Materials for Lithium-Ion Batteries. Adv. Funct.

  7. Investigation of IAQ-Relevant Surface Chemistry and Emissions on HVAC Filter Materials

    E-Print Network [OSTI]

    Destaillats, Hugo

    2010-01-01T23:59:59.000Z

    VOCs emitted by reactions of HVAC filters with ozone usingChemistry and Emissions on HVAC Filter Materials HugoChemistry and Emissions on HVAC Filter Materials Authors:

  8. To understand the reliability of materials and how well they can perform, it is critical to analyze their surfaces. To accomplish this

    E-Print Network [OSTI]

    Denham, Graham

    To understand the reliability of materials and how well they can perform, it is critical to analyze and materials. The facility supports academic and industrial clients who are looking for technological components analyze and evaluate the surfaces of their materials and understand why these surfaces might fail

  9. Final Report: MATERIALS, STRANDS, AND CABLES FOR SUPERCONDUCTING ACCELERATOR MAGNETS [Grant Number DE-SC0010312

    SciTech Connect (OSTI)

    Sumption, Mike; Collings, E.

    2014-10-29T23:59:59.000Z

    Our program consisted of the two components: Strand Research and Cable Research, with a focus on Nb3Sn, Bi2212, and YBCO for accelerator magnet applications. We demonstrated a method to refine the grains in Nb3Sn by a factor of two, reaching 45 nm grain sizes, and layer Jcs of 6 kA/mm2 at 12 T. W also measured conductor magnetization for field quality. This has been done both with Nb3Sn conductor, as well as Bi:2212 strand. Work in support of quench studies of YBCO coils was also performed. Cable loss studies in Nb3Sn focused on connecting and comparing persistent magnetization and coupling magnetization for considering their relative impact on HEP machines. In the area of HTS cables, we have investigated both the quench in multistrand YBCO CORC cables, as well as the magnetization of these cables for use in high field magnets. In addition, we examined the magnetic and thermal properties of large (50 T) solenoids.

  10. Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process

    DOE Patents [OSTI]

    Gschneidner, Jr., Karl A. (Ames, IA); Pecharsky, Vitalij K. (Ames, IA)

    1998-04-28T23:59:59.000Z

    Active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing.

  11. Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process

    DOE Patents [OSTI]

    Gschneidner, K.A. Jr.; Pecharsky, V.K.

    1998-04-28T23:59:59.000Z

    Active magnetic regenerator and method using Gd{sub 5} (Si{sub x}Ge{sub 1{minus}x}){sub 4}, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd{sub 5} (Si{sub x} Ge{sub 1{minus}x}){sub 4}, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing. 27 figs.

  12. External proton beam analysis of plasma facing materials for magnetic confinement fusion applications

    E-Print Network [OSTI]

    Barnard, Harold Salvadore

    2009-01-01T23:59:59.000Z

    A 1.7MV tandem accelerator was reconstructed and refurbished for this thesis and for surface science applications at the Cambridge laboratory for accelerator study of surfaces (CLASS). At CLASS, an external proton beam ...

  13. Methods and materials for nanocrystalline surface coatings and attachment of peptide amphiphile nanofibers thereon

    DOE Patents [OSTI]

    Stupp, Samuel I. (Chicago, IL); Spoerke, Erik D. (Albuquerque, NM); Anthony, Shawn G. (New Stanton, PA); Niece; Krista L. (Evanston, IL)

    2008-06-24T23:59:59.000Z

    Biocompatible composites comprising peptide amphiphiles and surface modified substrates and related methods for attachment thereon.

  14. Study of Interfacial Interactions Using Thing Film Surface Modification: Radiation and Oxidation Effects in Materials

    SciTech Connect (OSTI)

    Sridharan, Kumar; Zhang, Jinsuo

    2014-01-09T23:59:59.000Z

    Interfaces play a key role in dictating the long-term stability of materials under the influence of radiation and high temperatures. For example, grain boundaries affect corrosion by way of providing kinetically favorable paths for elemental diffusion, but they can also act as sinks for defects and helium generated during irradiation. Likewise, the retention of high-temperature strength in nanostructured, oxide-dispersion strengthened steels depends strongly on the stoichiometric and physical stability of the (Y, Ti)-oxide particles/matrix interface under radiation and high temperatures. An understanding of these interfacial effects at a fundamental level is important for the development of materials for extreme environments of nuclear reactors. The goal of this project is to develop an understanding stability of interfaces by depositing thin films of materials on substrates followed by ion irradiation of the film-substrate system at elevated temperatures followed by post-irradiation oxidation treatments. Specifically, the research will be performed by depositing thin films of yttrium and titanium (~500 nm) on Fe-12%Cr binary alloy substrate. Y and Ti have been selected as thin-film materials because they form highly stable protective oxides layers. The Fe-12%Cr binary alloy has been selected because it is representative of ferritic steels that are widely used in nuclear systems. The absence of other alloying elements in this binary alloy would allow for a clearer examination of structures and compositions that evolve during high-temperature irradiations and oxidation treatments. The research is divided into four specific tasks: (1) sputter deposition of 500 nm thick films of Y and Ti on Fe-12%Cr alloy substrates, (2) ion irradiation of the film-substrate system with 2MeV protons to a dose of 2 dpa at temperatures of 300°C, 500°C, and 700°C, (3) oxidation of as-deposited and ion-irradiated samples in a controlled oxygen environment at 500°C and 700°C, (4) multi-scale computational modeling involving first- principle molecular dynamics (FPMD) and coarse-grained dissipative particle dynamics (DPD) approaches to develop theories underlying the evolution and stability of structures and phases. Samples from Tasks 1 to 3 (above) will be rigorously characterized and analyzed using scanning electron microscopy, Auger electron microscopy, x-ray diffraction, Rutherford back scatter spectroscopy, and transmission electron microscopy. Expected outcomes of the experimental work include a quantitative understanding film-substrate interface mixing, evolution of defects and other phases at the interface, interaction of interfaces with defects, and the ability of the Y and Ti films to mitigate irradiation-assisted oxidation.The aforementioned experimental work will be closely coupled with multi-scale molecular dynamics (MD) modeling to understand the reactions at the surface, the transport of oxidant through the thin film, and the stabilities of the deposited thin films under radiation and oxidation. Simulations of materials property changes under conditions of radiation and oxidation require multiple size domains and a different simulation scheme for each of these domains. This will be achieved by coupling the FPMD and coarse-grained kinetic Monte Carlo (KMC). This will enable the comparison of the results of each simulation approach with the experimental results.

  15. Surface modified CFx cathode material for ultrafast discharge and high energy density

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dai, Yang [Shanghai Inst. of Space Power Sources, Shanghai (China); Zhu, Yimei [Brookhaven National Lab. (BNL), Upton, NY (United States); Cai, Sendan [Shanghai Inst. of Space Power Sources, Shanghai (China); Wu, Lijun [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, Weijing [Shanghai Inst. of Space Power Sources, Shanghai (China); Xie, Jingying [Shanghai Inst. of Space Power Sources, Shanghai (China); Shanghai Engineering Center for Power and Energy Storage Systems, Shanghai (China); Wen, Wen [BL14B1 Shanghai Synchrotron Radiation Facility, Shanghai (China); Zheng, Jin-Cheng [Xiamen Univ., Xiamen (China); Zheng, Yi [Shanghai Inst. of Space Power Sources, Shanghai (China)

    2014-01-01T23:59:59.000Z

    Li/CFx primary possesses the highest energy density of 2180 W h kg?¹ among all primary lithium batteries. However, a key limitation for the utility of this type of battery is in its poor rate capability because the cathode material, CFx, is an intrinsically poor electronic conductor. Here, we report on our development of a controlled process of surface de-fluorination under mild hydrothermal conditions to modify the highly fluorinated CFx. The modified CFx, consisting of an in situ generated shell component of F-graphene layers, possesses good electronic conductivity and removes the transporting barrier for lithium ions, yielding a high-capacity performance and an excellent rate-capability. Indeed, a capacity of 500 mA h g?¹ and a maximum power density of 44 800 W kg?¹ can be realized at the ultrafast rate of 30 C (24 A g?¹), which is over one order of magnitude higher than that of the state-of-the-art primary lithium-ion batteries.

  16. Surface modified CFx cathode material for ultrafast discharge and high energy density

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dai, Yang; Zhu, Yimei; Cai, Sendan; Wu, Lijun; Yang, Weijing; Xie, Jingying; Wen, Wen; Zheng, Jin-Cheng; Zheng, Yi

    2014-01-01T23:59:59.000Z

    Li/CFx primary possesses the highest energy density of 2180 W h kg?¹ among all primary lithium batteries. However, a key limitation for the utility of this type of battery is in its poor rate capability because the cathode material, CFx, is an intrinsically poor electronic conductor. Here, we report on our development of a controlled process of surface de-fluorination under mild hydrothermal conditions to modify the highly fluorinated CFx. The modified CFx, consisting of an in situ generated shell component of F-graphene layers, possesses good electronic conductivity and removes the transporting barrier for lithium ions, yielding a high-capacity performance andmore »an excellent rate-capability. Indeed, a capacity of 500 mA h g?¹ and a maximum power density of 44 800 W kg?¹ can be realized at the ultrafast rate of 30 C (24 A g?¹), which is over one order of magnitude higher than that of the state-of-the-art primary lithium-ion batteries.« less

  17. Materials and surface aspects in the development of SRF Niobium cavities

    E-Print Network [OSTI]

    Antoine, C

    2012-01-01T23:59:59.000Z

    Foreword from author; When I joined the CEA Saclay SRF group in 1989, my initial background was physical chemistry and surface science, which I completed later on with solid state physics and metallurgy. Most accelerator physicists at that time had training in RF, plasma physics, nuclear or particle physics. We were very few with a background in material science. Working with people with a different background than yours reveals to be both challenging and funny: you can impress them with things you consider basic while they simply do not believe you for other things you consider so well admitted that you do not even remember where it comes from. At the end it obliges you to reconsider your basics and re-question many results, which opens many new and sometimes unexpected paths. Like usual in science, answering one question rises many new ones, and trying to improve cavities performance led to fascinating physics problems. Exploring some of these problems often requires techniques and expertise that are far be...

  18. Method for preparing high cure temperature rare earth iron compound magnetic material

    DOE Patents [OSTI]

    Huang, Yuhong (West Hills, CA); Wei, Qiang (West Hills, CA); Zheng, Haixing (Oak Park, CA)

    2002-01-01T23:59:59.000Z

    Insertion of light elements such as H,C, or N in the R.sub.2 Fe.sub.17 (R=rare earth metal) series has been found to modify the magnetic properties of these compounds, which thus become prospective candidates for high performance permanent magnets. The most spectacular changes are increases of the Curie temperature, T.sub.c, of the magnetization, M.sub.s, and of coercivity, H.sub.c, upon interstitial insertion. A preliminary product having a component R--Fe--C,N phase is produced by a chemical route. Rare earth metal and iron amides are synthesized followed by pyrolysis and sintering in an inert or reduced atmosphere, as a result of which, the R--Fe--C,N phases are formed. Fabrication of sintered rare earth iron nitride and carbonitride bulk magnet is impossible via conventional process due to the limitation of nitridation method.

  19. Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label for large aspect ratio

    SciTech Connect (OSTI)

    Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E. [Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

    2014-06-15T23:59:59.000Z

    An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label.

  20. Incorporation of 4d and 5d Transition Metal Cyanometallates into Magnetic Clusters and Materials.

    E-Print Network [OSTI]

    Hilfiger, Matthew Gary

    2011-08-08T23:59:59.000Z

    scenarios: (a) A ferromagnet where neighboring spins align in a parallel fashion with the magnetic field and retain their directionality even when the field is removed; (b) An antiferromagnet wherein the spins of neighboring centers couple... scheme of Prussian Blue analogs, M' = V,Cr, Fe, Co, M = V, Cr, Mn, Fe, Ni , L = labile ligand or solvent molecule. 6 cancel, and the remaining unpaired spins align with the field as a ferromagnet does (Scheme 2a). Although these magnetic...

  1. Development of accelerator based spatially resolved ion beam analysis techniques for the study of plasma materials interactions in magnetic fusion devices

    E-Print Network [OSTI]

    Barnard, Harold Salvadore

    2014-01-01T23:59:59.000Z

    Plasma-material interactions (PMI) in magnetic fusion devices pose significant scientific and engineering challenges for the development of steady-state fusion power reactors. Understanding PMI is crucial for the develpment ...

  2. A model for materials scientists: Water runs off the surface of a lotus leaf without a trace. Researchers

    E-Print Network [OSTI]

    on the water, not only dry but, most importantly, clean. As the water runs off, it rinses away the dirt, whichA model for materials scientists: Water runs off the surface of a lotus leaf without a trace. Researchers in Mainz use this concept to develop coatings that repel both water and oil. #12;TEXT ROLAND

  3. Correlating Radioactive Material to Sea Surface Temperature off the Coast of Japan: The Fukushima Daiichi Nuclear Disaster

    E-Print Network [OSTI]

    Gilbes, Fernando

    Correlating Radioactive Material to Sea Surface Temperature off the Coast of Japan: The Fukushima on the island. One of the most devastating results of this was the damage to the Fukushima Daiichi nuclear plant, Fukushima INTRODUCTION On March 11, 2011, Japan suffered a devastating 9.0 Mw earthquake, now known

  4. Surfaces

    E-Print Network [OSTI]

    DeMaio, Ernest Vincent, 1964-

    1989-01-01T23:59:59.000Z

    Surfaces is a collection of four individual essays which focus on the characteristics and tactile qualities of surfaces within a variety of perceived landscapes. Each essay concentrates on a unique surface theme and purpose; ...

  5. Supporting On-Line Material for: Revealing Sub-Surface Vibrational Modes by Atom-Resolved

    E-Print Network [OSTI]

    yields the surface topography. By compensating long-range elec- trostatic and van der Waals interactions, it is possible to achieve true atomic resolution in surface topography FIG. 1: (Color) (a) Schematic operational, surface topography and energy loss E images are acquired simultaneously. (b) Close-up picture (left

  6. Atomistic Simulations of Bonding, Thermodynamics, and Surface Passivation in Nanoscale Solid Propellant Materials 

    E-Print Network [OSTI]

    Williams, Kristen

    2012-10-19T23:59:59.000Z

    Engineering new solid propellant materials requires optimization of several factors, to include energy density, burn rate, sensitivity, and environmental impact. Equally important is the need for materials that will maintain ...

  7. Interplay of superconductivity, magnetism, and density waves in rare-earth tritellurides and iron-based superconducting materials

    E-Print Network [OSTI]

    Zocco, Diego Andrés

    2011-01-01T23:59:59.000Z

    3. Magnetism in Metals . . . . . . . . . . . . . . . . .IV Superconductivity and Magnetism in Iron-PnictideIII Superconductivity, Magnetism and Charge-Density Waves in

  8. Effects of magnetic flux density and substrate bias voltage on Ni films prepared on a flexible substrate material using unbalanced magnetron sputtering assisted by inductively coupled plasma

    SciTech Connect (OSTI)

    Koda, Tatsunori [Graduate School of Science and Technology, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 7315193 (Japan); Toyota, Hiroshi, E-mail: h.toyota.za@it-hiroshima.ac.jp [Department of Electronics and Computer Engineering, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 7315193 (Japan)

    2014-03-15T23:59:59.000Z

    The authors fabricated Ni films on a flexible substrate material using unbalanced magnetron sputtering assisted by inductively coupled plasma. The effects of magnetic flux density B{sub C} and substrate DC bias voltage V{sub S} on the Ni film structures were investigated. For V{sub S}?=??40?V, the average surface grain size D{sub G} measured by atomic force microscopy for B{sub C}?=?0, 3, and 5?mT was 88.2, 95.4, and 104.4?nm, respectively. In addition, D{sub G} increased with V{sub S}. From x-ray diffraction measurements, the (111) and (200) peaks were clearly visible for the fabricated Ni films. The ratio of the integrated intensities of I(111)/I(200) increased with V{sub S}. For V{sub S}?=??40?V and B{sub C}?=?3?mT, a film resistivity ? of 8.96?×?10{sup ?6} ? cm was observed, which is close to the Ni bulk value of 6.84?×?10{sup ?6} ? cm. From these results, the authors determined that the structure of the fabricated Ni films on the flexible substrate material was affected by the values of B{sub C} and V{sub S}.

  9. Surface-Gasification Materials Program. Semiannual progress report for the period ending March 31, 1983

    SciTech Connect (OSTI)

    Bradley, R.A. (comp.)

    1983-05-01T23:59:59.000Z

    Contents of this semiannual report include the following: introduction; (1) plant materials surveillance tests (Illinois Institute of Technology); (2) slagging gasifier refractories - appliction/evaluation (Argonne National Laboratory); (3) protective clothing and claddings - application/evaluation (ANL); (4) ceramic application technology - brittle material design (LANL); (5) advanced pressure vessel materials technology (ORNL); (6) electroslag component casting (ORNL); (7) cost reduction of the electroslag casting manufacturing process (CMU); (8) materials review and component failure analysis in support of coal gasification processes and plants (ANL); (9) process plant materials review, evaluation, and support (ORNL).

  10. JOURNAL OF MATERIALS SCIENCE 37 (2002) 2441 2446 Influence of L uders bands on magnetic

    E-Print Network [OSTI]

    Clapham, Lynann

    2002-01-01T23:59:59.000Z

    is primarily utilized for the detection of corrosion defects in oil and gas pipelines [6, 7]. As most and gas pipelines during in-service aging act as stress raisers as these pipelines are operated at up. The MFL results indicate that magnetic flux leaks out into the air from regions with L ¨uders bands due

  11. Effect of the porosity on the fracture surface roughness of sintered materials: From anisotropic to isotropic self-affine scaling

    E-Print Network [OSTI]

    Tristan Cambonie; Jonathan Bares; Lamine Hattali; Daniel Bonamy; Véronique Lazarus; Harold Auradou

    2015-01-16T23:59:59.000Z

    To unravel how the microstructure affects the fracture surface roughness in heterogeneous brittle solids like rocks or ceramics, we characterized the roughness statistics of post-mortem fracture surfaces in home-made materials of adjustable microstructure length-scale and porosity, obtained by sintering monodisperse polystyrene beads. Beyond the characteristic size of disorder, the roughness profiles are found to exhibit self-affine scaling features evolving with porosity. Starting from a null value and increasing the porosity, we quantitatively modify the self-affine scaling properties from anisotropic (at low porosity) to isotropic (for porosity larger than 10 %).

  12. Investigation of IAQ-Relevant Surface Chemistry and Emissions on HVAC Filter Materials

    SciTech Connect (OSTI)

    Destaillats, Hugo; Fisk, William J.

    2010-02-01T23:59:59.000Z

    Chemical reactions involving ozone of outdoor origin and indoor materials are known to be significant sources of formaldehyde and other irritant gas-phase oxidation products in the indoor environment. HVAC filters are exposed to particularly high ozone concentrations--close to outdoor levels. In this study, we investigated chemical processes taking place on the surface of filters that included fiberglass, polyester, cotton/polyester blend and synthetic (e.g., polyolefin) filter media. Ozone reactions were studied on unused filter media, and on filters that were deployed for 3 months in two different locations: at the Lawrence Berkeley National Laboratory and at the Port of Oakland. Specimens from each filter were exposed to ozone under controlled conditions in a laboratory flow tube at a constant flow of dry or humidified air (50percent relative humidity). Ozone was generated with a UV source upstream of the flow tube, and monitored using a photometric detector. Ozone breakthrough curves were recorded for each sample exposed to ~;;150 ppbv O3 for periods of ~;;1000 min, from which we estimated their uptake rate. Most experiments were performed at 1.3 L/min (corresponding to a face velocity of 0.013 m/s), except for a few tests performed at a higher airflow rate, to obtain a face velocity of 0.093 m/s, slightly closer to HVAC operation conditions. Formaldehyde and acetaldehyde, two oxidation byproducts, were collected downstream of the filter and quantified. Emissions of these volatile aldehydes were consistently higher under humidified air than under dry conditions, at which levels were near the limit of detection. Our results confirm that there are significant reactions of ozone as air containing ozone flows through HVAC filters, particularly when the filters are loaded with particles and the air is humidified. The amount of ozone reacted was not clearly related to the types of filter media, e.g., fiberglass versus synthetic. Specific fiberglass filters that were coated with an impaction oil showed significantly higher formaldehyde emissions than most other samples. Those emissions were magnified in the presence of particles (i.e., in used filters), and were observed even in the absence of ozone, which suggests that hydrolysis of filter binder or tackifier additives may be the reason for those high emissions. Mass balance calculations indicate that the emission rates of formaldehyde and acetaldehyde from the filters are generally not large enough to substantially increase indoor formaldehyde or acetaldehyde concentrations.

  13. Surface reconstruction and chemical evolution of stoichiometric layered cathode materials for lithium-ion batteries

    E-Print Network [OSTI]

    Lin, Feng

    2014-01-01T23:59:59.000Z

    Layered Oxides for Lithium Batteries. Nano Lett. 13, 3857–O 2 Cathode Material in Lithium Ion Batteries. Adv. Energydecomposition in lithium ion batteries: first-principles

  14. Performance of a copper-lithium alloy as an impurity control system surface material for a fusion reactor

    SciTech Connect (OSTI)

    Brooks, J.N.; Krauss, A.R.; Mattas, R.F.; DeWald, A.B.

    1984-10-01T23:59:59.000Z

    A copper-lithium alloy was evaluated as a surface material for the impurity control system of the INTOR reactor. Both the medium edge temperature limiter regime and the low edge temperature divertor regime were examined. The analysis used TRIM code data to predict sputtering coefficients for copper-lithium with a 1.5 monolayer coverage of lithium. The REDEP code was used to evaluate the erosion performance for INTOR. Other properties such as fabrication and thermal performance were also briefly assessed. It was found, from the standpoint of erosion, that copper-lithium is a very good candidate material for the medium edge temperature regime, and also works well in the low edge temperature regime. For the medium edge temperature regime, the use of copper-lithium results in an almost negligible erosion rate over the entire limiter surface.

  15. Superconductivity on the surface of topological insulators and in two-dimensional noncentrosymmetric materials

    E-Print Network [OSTI]

    Superconductivity on the surface of topological insulators and in two, as it pertains to the surface of a three-dimensional time-reversal symmetric topological band insulator. We also TRS topological band insulator.7­9 In a recent work, Hor et al.10 have reported the observation

  16. Effect of net surface charge on particle sizing and material recognition by using phase Doppler anemometry

    SciTech Connect (OSTI)

    Zhou Jun; Xie Li

    2011-01-20T23:59:59.000Z

    By taking net surface charge into consideration, the scattering field of particles illuminated by dual laser beams of phase Doppler anemometry (PDA) is computed based on Mie's theory, and the effect of net surface charge on the phase-diameter relationship and the phase ratio is studied. It is found that the phase-diameter relationship and the relationship between the phase ratio and the refractive index of charged particles could be significantly different from those of uncharged particles, which would lead to errors in particle sizing and the measurement of refractive indices. A method of recognizing charged particles and determining the value of their surface conductivity, which is related to net surface charge, is proposed by utilizing the effect of net surface charge on the measurement of refractive indices using PDA.

  17. The evaluation of micro-surfacing mixture design procedures and the effects of material variation on the test responses

    E-Print Network [OSTI]

    Andrews, Edward Mensah

    1994-01-01T23:59:59.000Z

    the potential of the fore-mentioned ISSA test methods for assessing mixture design adequacy. As previously mentioned the ISSA Technical Design Guidelines (JAN 1991) form the basis of the tests to be performed. The procedures and apparatus needed and used... as materials are varied is reiterated. Suggestions for further research needed are made. ISSA MIXTURE DESIGN PROCEDURES General The International Slurry Surfacing Association design technical bulletin (Jan 1991) (5) contains guidelines for the laboratory...

  18. Device Fabrication and Processing > Thin Film ALD, RF/DC Magnetic Materials and Co-

    E-Print Network [OSTI]

    Das, Suman

    .ien.gatech.edu Materials Processed > Dielectrics: SiO2, Si3N4,SiC, HfO2, ZnO, ZrO2, AlN, TiN, TiO2, Al2O3, additional dielectrics on request > Metals: Al, Cr, Ti, W, Ni, Mo, Pt, Fe, Cu, Ir, Pd, Ag, additional metals by request RIE; HBr-based ICP; Metals ­ Al, Cr, Ti, W, Ag > Wet Etching: SiO2, Si3N4 Metals, Organic materials

  19. Rare-Earth-Free Nanostructure Magnets: Rare-Earth-Free Permanent Magnets for Electric Vehicle Motors and Wind Turbine Generators: Hexagonal Symmetry Based Materials Systems Mn-Bi and M-type Hexaferrite

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    REACT Project: The University of Alabama is developing new iron- and manganese-based composite materials for use in the electric motors of EVs and renewable power generators that will demonstrate magnetic properties superior to today’s best rare-earth-based magnets. Rare earths are difficult and expensive to refine. EVs and renewable power generators typically use rare earths to make their electric motors smaller and more powerful. The University of Alabama has the potential to improve upon the performance of current state-of-the-art rare-earth-based magnets using low-cost and more abundant materials such as manganese and iron. The ultimate goal of this project is to demonstrate improved performance in a full-size prototype magnet at reduced cost.

  20. Mixing zones in magnetized differentially rotating stars

    E-Print Network [OSTI]

    V. Urpin

    2005-09-29T23:59:59.000Z

    We study the secular instability of magnetized differentially rotating radiative zones taking account of viscosity and magnetic and thermal diffusivities. The considered instability generalizes the well-known Goldreich-Schubert-Fricke instability for the case of a sufficiently strong magnetic field. In magnetized stars, instability can lead to a formation of non-spherical unstable zones where weak turbulence mixes the material between the surface and interiors. Such unstable zones can manifest themselves by a non-spherical distribution of abundance anormalies on the stellar surface.

  1. Surface Modification of Material by Irradiation of Low Power Atmospheric Pressure Plasma Jet

    SciTech Connect (OSTI)

    Akamatsu, Hiroshi; Ichikawa, Kazunori [Kobe City College of Technology, 8-3 Gakuenhigashimachi, Kobe, Hyogo, 651-2194 (Japan); Azuma, Kingo [University of Hyogo, 2167 Shosya, Himeji, Hyogo, 671-2280 (Japan); Onoi, Masahiro [Metal Technology Co., Ltd., 713 Shake Aza Narihira, Ebina, Kanagawa, 243-0424 (Japan)

    2010-10-13T23:59:59.000Z

    Application of a low power atmospheric pressure plasma jet for surface modifications of acrylic, aluminum, and highly crystalline graphite has been carried out experimentally. The plasma jet was generated with batteries-driven high voltage modulator. The power consumed for the plasma generation was estimated to be 0.12 W. The plasma had hydroxyl radicals, which is known as a strong oxider from an observation of optical emission spectrum. After the irradiation of the plasma, the surfaces of acrylic and aluminum became to be hydrophilic from the compartment of contact angle of water on these surfaces. The surface of highly crystalline graphite irradiated by the plasma jet had oxygen-rich functional groups such as C-O, C = O, and O = C-O.

  2. Nanostructured multifunctional materials for control of light transport and surface wettability

    E-Print Network [OSTI]

    Choi, Hyungryul

    2014-01-01T23:59:59.000Z

    Biological surfaces have evolved to optimize their structures and physical and chemical properties at the micro/nanoscale for adaptation to different environments, exhibiting a wide variety of beneficial functions, ranging ...

  3. Method of bonding functional surface materials to substrates and applications in microtechnology and antifouling

    DOE Patents [OSTI]

    Feng, Xiangdong (West Richland, WA); Liu, Jun (West Richland, WA); Liang, Liang (Richland, WA)

    1999-01-01T23:59:59.000Z

    A simple and effective method to bond a thin coating of poly(N-isopropylacylamide) (NIPAAm) on a glass surface by UV photopolymerization, and the use of such a coated surface in nano and micro technology applications. A silane coupling agent with a dithiocarbamate group is provided as a photosensitizer, preferably, (N,N'-diethylamine)dithiocarbamoylpropyl-(trimethoxy)silane (DATMS). The thiocarbamate group of the sensitizer is then bonded to the glass surface by coupling the silane agent with the hydroxyl groups on the glass surface. The modified surface is then exposed to a solution of NIPAAm and a crosslinking agent which may be any organic molecule having an acrylamide group and at least two double bonds in its structure, such as N,N'-methylenebisacrylamide, and a polar solvent which may be any polar liquid which will dissolve the monomer and the crosslinking agent such as acetone, water, ethanol, or combinations thereof. By exposing the glass surface to a UV light, free radicals are generated in the thiocarbamate group which then bonds to the crosslinking agent and the NIPAAm. Upon bonding, the crosslinking agent and the NIPAAm polymerize to form a thin coating of PNIPAAm bonded to the glass. Depending upon the particular configuration of the glass, the properties of the PNIPAAm allow applications in micro and nano technology.

  4. Method of bonding functional surface materials to substrates and applications in microtechnology and anti-fouling

    DOE Patents [OSTI]

    Feng, Xiangdong (West Richland, WA); Liu, Jun (West Richland, WA); Liang, Liang (Richland, WA)

    2001-01-01T23:59:59.000Z

    A simple and effective method to bond a thin coating of poly(N-isopropylacylamide) (NIPAAm) on a glass surface by UV photopolymerization, and the use of such a coated surface in nano and micro technology applications. A silane coupling agent with a dithiocarbamate group is provided as a photosensitizer preferably, (N,N'-diethylamine) dithiocarbamoylpropyl-(trimethoxy) silane (DATMS). The thiocarbamate group of the sensitizer is then bonded to the glass surface by coupling the silane agent with the hydroxyl groups on the glass surface. The modified surface is then exposed to a solution of NIPAAm and a crosslinking agent which may be any organic molecule having an acrylamide group and at least two double bonds in its structure, such as N, N'-methylenebisacrylamide, and a polar solvent which may be any polar liquid which will dissolve the monomer and the crosslinking agent such as acetone, water, ethanol, or combinations thereof. By exposing the glass surface to a UV light, free radicals are generated in the thiocarbamate group which then bonds to the crosslinking agent and the NIPAAm. Upon bonding, the crosslinking agent and the NIPAAm polymerize to form a thin coating of PNIPAAm bonded to the glass. Depending upon the particular configuration of the glass, the properties of the PNIPAAm allow applications in micro and nano technology.

  5. Surface reconstruction and chemical evolution of stoichiometric layered cathode materials for lithium-ion batteries

    E-Print Network [OSTI]

    Lin, Feng

    2014-01-01T23:59:59.000Z

    Layered Oxides for Lithium Batteries. Nano Lett. 13, 3857–Material in Lithium Ion Batteries. Adv. Energy Mater. n/a–n/decomposition in lithium ion batteries: first-principles

  6. Noncollinear magnetism of Cr clusters on Fe surfaces R. Robles and L. Nordstrm

    E-Print Network [OSTI]

    Rodriguez, Roberto

    in high-density magnetic storage devices. In low- dimensionality systems, like free or supported The study of supported nanostructures has attracted a lot of attention from the scientific community the intrinsic properties of the nanostructure and the properties of the substrate. So in order to elucidate them

  7. Materials

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |IsLove Your Home andDisposition | NationalMaterials

  8. The Shapes of Atomic Lines from the Surfaces of Weakly Magnetic Rotating Neutron Stars and Their Implications

    E-Print Network [OSTI]

    Sudip Bhattacharyya; M. Coleman Miller; Frederick K. Lamb

    2006-06-26T23:59:59.000Z

    Motivated by the report by Cottam et al. (2002) of iron resonance scattering lines in the spectra of thermonuclear bursts from EXO 0748-676, we have investigated the information about neutron star structure and the geometry of the emission region that can be obtained by analyzing the profiles of atomic lines formed at the surface of the star. We have calculated the detailed profiles of such lines, taking into account the star's spin and the full effects of special and general relativity, including light-bending and frame-dragging. We discuss the line shapes produced by rotational Doppler broadening and magnetic splitting of atomic lines, for the spin rates and magnetic fields expected in neutron stars in low-mass X-ray binary systems. We show that narrow lines are possible even for rapidly spinning stars, if the emission region or the line of sight are close to the spin axis. For most neutron stars in low-mass systems, magnetic splitting is too small to obscure the effects of special and general relativity. We show that the ratio of the star's mass to its equatorial radius can be determined to within 5% using atomic line profiles, even if the lines are broad and skewed. This is the precision required to constrain strongly the equation of state of neutron star matter. We show further that if the radius and latitude of emission are known to ~ 5-10% accuracy, then frame-dragging has a potentially detectable effect on the profiles of atomic lines formed at the stellar surface.

  9. Assessment of martensitic steels as structural materials in magnetic fusion devices

    SciTech Connect (OSTI)

    Rawls, J.M.; Chen, W.Y.K.; Cheng, E.T.; Dalessandro, J.A.; Miller, P.H.; Rosenwasser, S.N.; Thompson, L.D.

    1980-01-01T23:59:59.000Z

    This manuscript documents the results of preliminary experiments and analyses to assess the feasibility of incorporating ferromagnetic martensitic steels in fusion reactor designs and to evaluate the possible advantages of this class of material with respect to first wall/blanket lifetime. The general class of alloys under consideration are ferritic steels containing from about 9 to 13 percent Cr with some small additions of various strengthening elements such as Mo. These steels are conventionally used in the normalized and tempered condition for high temperature applications and can compete favorably with austenitic alloys up to about 600/sup 0/C. Although the heat treatment can result in either a tempered martensite or bainite structure, depending on the alloy and thermal treatment parameters, this general class of materials will be referred to as martensitic stainless steels for simplicity.

  10. Method of making active magnetic refrigerant, colossal magnetostriction and giant magnetoresistive materials based on Gd-Si-Ge alloys

    DOE Patents [OSTI]

    Gschneidner, Jr., Karl A. (Ames, IA); Pecharsky, Alexandra O. (Ames, IA); Pecharsky, Vitalij K. (Ames, IA)

    2003-07-08T23:59:59.000Z

    Method of making an active magnetic refrigerant represented by Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4 alloy for 0.ltoreq.x.ltoreq.1.0 comprising placing amounts of the commercially pure Gd, Si, and Ge charge components in a crucible, heating the charge contents under subambient pressure to a melting temperature of the alloy for a time sufficient to homogenize the alloy and oxidize carbon with oxygen present in the Gd charge component to reduce carbon, rapidly solidifying the alloy in the crucible, and heat treating the solidified alloy at a temperature below the melting temperature for a time effective to homogenize a microstructure of the solidified material, and then cooling sufficiently fast to prevent the eutectoid decomposition and improve magnetocaloric and/or the magnetostrictive and/or the magnetoresistive properties thereof.

  11. Temporal measurements of surfactant squeeze-out from a surface using magnetically levitated liquid bridges

    E-Print Network [OSTI]

    Taylor, Philip L.

    A cylindrical liquid bridge, laden with surfactant and constrained at the two ends by circular rods area Langmuir trough with a plate that monitors the surface tension [6]. This techni- que is useful

  12. Surface treated natural graphite as anode material for high-power Li-ion battery applications.

    SciTech Connect (OSTI)

    Liu, J.; Vissers, D. R.; Amine, K.; Barsukov, I. V.; Henry, F.; Doniger, J.; Chemical Engineering; Superior Graphite Co.

    2006-01-01T23:59:59.000Z

    High power application of Li-ion battery in hybrid electrical vehicles requires low cost and safe cell materials. Among the various carbon anode materials used in lithium ion batteries, natural graphite shows the most promise with advantages in performance and cost. However, natural graphite is not compatible with propylene carbonate (PC)-based electrolytes, which have a lower melting point and improved safety characteristics. The problem with it is that the molecules of propylene carbonate intercalate with Li+ into graphite, and that frequently leads to the exfoliation of the graphite matrix.

  13. LANL Virtual Center for Chemical Hydrogen Storage: Chemical Hydrogen Storage Using Ultra-high Surface Area Main Group Materials

    SciTech Connect (OSTI)

    Susan M. Kauzlarich; Phillip P. Power; Doinita Neiner; Alex Pickering; Eric Rivard; Bobby Ellis, T. M.; Atkins, A. Merrill; R. Wolf; Julia Wang

    2010-09-05T23:59:59.000Z

    The focus of the project was to design and synthesize light element compounds and nanomaterials that will reversibly store molecular hydrogen for hydrogen storage materials. The primary targets investigated during the last year were amine and hydrogen terminated silicon (Si) nanoparticles, Si alloyed with lighter elements (carbon (C) and boron (B)) and boron nanoparticles. The large surface area of nanoparticles should facilitate a favorable weight to volume ratio, while the low molecular weight elements such as B, nitrogen (N), and Si exist in a variety of inexpensive and readily available precursors. Furthermore, small NPs of Si are nontoxic and non-corrosive. Insights gained from these studies will be applied toward the design and synthesis of hydrogen storage materials that meet the DOE 2010 hydrogen storage targets: cost, hydrogen capacity and reversibility. Two primary routes were explored for the production of nanoparticles smaller than 10 nm in diameter. The first was the reduction of the elemental halides to achieve nanomaterials with chloride surface termination that could subsequently be replaced with amine or hydrogen. The second was the reaction of alkali metal Si or Si alloys with ammonium halides to produce hydrogen capped nanomaterials. These materials were characterized via X-ray powder diffraction, TEM, FTIR, TG/DSC, and NMR spectroscopy.

  14. Oxidation of carbon fiber surfaces for use as reinforcement in high-temperature cementitious material systems

    DOE Patents [OSTI]

    Sugama, Toshifumi (Mastic Beach, NY)

    1990-01-01T23:59:59.000Z

    The interfacial bond characteristics between carbon fiber and a cement matrix, in high temperature fiber-reinforced cementitious composite systems, can be improved by the oxidative treatment of the fiber surfaces. Compositions and the process for producing the compositions are disclosed.

  15. Oxidation of carbon fiber surfaces for use as reinforcement in high-temperature cementitious material systems

    DOE Patents [OSTI]

    Sugama, Toshifumi.

    1990-05-22T23:59:59.000Z

    The interfacial bond characteristics between carbon fiber and a cement matrix, in high temperature fiber-reinforced cementitious composite systems, can be improved by the oxidative treatment of the fiber surfaces. Compositions and the process for producing the compositions are disclosed. 2 figs.

  16. Atomistic Simulations of Bonding, Thermodynamics, and Surface Passivation in Nanoscale Solid Propellant Materials

    E-Print Network [OSTI]

    Williams, Kristen

    2012-10-19T23:59:59.000Z

    , the properties of COOH-terminated passivating agents were modeled with the GPW method. It is confirmed that fluorinated polymers bind to both Al(111) and Al(100) at two Al surface sites. The oligomers HCOOH, CH3CH2COOH, and CF3CF2COOH chemisorb onto Al(111...

  17. Electrochemical phenomena provide unique methods for materials synthesis and surface modification. Within this framework, the group

    E-Print Network [OSTI]

    Acton, Scott

    components for information storage, sensors and energy conversion devices. "Further the understanding to tailor to specification materials and components for a variety of devices, focusing on micro of a variety of self-assembled nanostructures, as well as the development and integration of suitable

  18. Investigations of the electronic and magnetic structures of Co{sub 2}YGa (Y=Cr, Mn) Heusler alloys and their (100) surfaces

    SciTech Connect (OSTI)

    Hamad, Bothina, E-mail: b.hamad@ju.edu.jo [Physics Department, The University of Jordan, Amman-11942 (Jordan)

    2014-03-21T23:59:59.000Z

    Density functional theory calculations are performed to investigate the structural, electronic, and magnetic properties of bulk structures of Co{sub 2}YGa (Y?=?Cr, Mn) Heusler alloys and the surfaces along the (100) orientation. The bulk structures of both alloys show a ferromagnetic behavior with total magnetic moments of 3.03?{sub B} and 4.09?{sub B} and high spin polarizations of 99% and 67% for Co{sub 2}CrGa and Co{sub 2}MnGa, respectively. The surfaces are found to exhibit corrugations due to different relaxations of the surface atoms. For the case of Co{sub 2}CrGa, two surfaces preserve the half metallicity, namely those with Cr-Ga and Ga– terminations with high spin polarizations above 90%, whereas it dropped to about 50% for the other surfaces. However, the spin polarizations of Co-Co and Mn-Ga terminated surfaces remain close to that of bulk Co{sub 2}MnGa alloy, whereas it is suppressed down to 17% for Co– termination. The highest local magnetic moments are found to be 3.26??{sub B} and 4.11??{sub B} for Cr and Mn surface atoms in Cr-Ga and Mn– terminated surfaces, respectively.

  19. Shear-horizontal surface acoustic wave phononic device with high density filling material for ultra-low power sensing applications

    SciTech Connect (OSTI)

    Richardson, M.; Bhethanabotla, V. R., E-mail: bhethana@usf.edu [Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, Florida 33620 (United States); Sankaranarayanan, S. K. R. S. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2014-06-23T23:59:59.000Z

    Finite element simulations of a phononic shear-horizontal surface acoustic wave (SAW) sensor based on ST 90°-X Quartz reveal a dramatic reduction in power consumption. The phononic sensor is realized by artificially structuring the delay path to form an acoustic meta-material comprised of a periodic microcavity array incorporating high-density materials such as tantalum or tungsten. Constructive interference of the scattered and secondary reflected waves at every microcavity interface leads to acoustic energy confinement in the high-density regions translating into reduced power loss. Tantalum filled cavities show the best performance while tungsten inclusions create a phononic bandgap. Based on our simulation results, SAW devices with tantalum filled microcavities were fabricated and shown to significantly decrease insertion loss. Our findings offer encouraging prospects for designing low power, highly sensitive portable biosensors.

  20. In Chemistry of Nanostructured Materials; Yang, P., Ed.; World Scientific Publishing: Hong Kong, 2003. MOLECULAR CLUSTER MAGNETS

    E-Print Network [OSTI]

    -density information storage, quantum computing, and magnetic refrigeration are briefly discussed. 1 Introduction Over magnets include high-density information storage, quantum computing, and magnetic refrigeration. Moreover, 2003. 291 MOLECULAR CLUSTER MAGNETS JEFFREY R. LONG Department of Chemistry, University of California

  1. The effects of surface chemistry of mesoporous silica materials and solution pH on kinetics of molsidomine adsorption

    SciTech Connect (OSTI)

    Dolinina, E.S.; Parfenyuk, E.V., E-mail: terrakott37@mail.ru

    2014-01-15T23:59:59.000Z

    Adsorption kinetics of molsidomine on mesoporous silica material (UMS), the phenyl- (PhMS) and mercaptopropyl-functionalized (MMS) derivatives from solution with different pH and 298 K was studied. The adsorption kinetics was found to follow the pseudo-second-order kinetic model for all studied silica materials and pH. Effects of surface functional groups and pH on adsorption efficiency and kinetic adsorption parameters were investigated. At all studied pH, the highest molsidomine amount is adsorbed on PhMS due to ?–? interactions and hydrogen bonding between surface groups of PhMS and molsidomine molecules. An increase of pH results in a decrease of the amounts of adsorbed molsidomine onto the silica materials. Furthermore, the highest adsorption rate kinetically evaluated using a pseudo-second-order model, is observed onto UMS and it strongly depends on pH. The mechanism of the adsorption process was determined from the intraparticle diffusion and Boyd kinetic film–diffusion models. The results showed that the molsidomine adsorption on the silica materials is controlled by film diffusion. Effect of pH on the diffusion parameters is discussed. - Graphical abstract: The kinetic study showed that the k{sub 2} value, the rate constant of pseudo-second order kinetic model, is the highest for molsidomine adsorption on UMS and strongly depends on pH because it is determined by availability and accessibility of the reaction sites of the adsorbents molsidomine binding. Display Omitted - Highlights: • The adsorption capacities of UMS, PhMS and MMS were dependent on the pH. • At all studied pH, the highest molsidomine amount is adsorbed on PhMS. • The highest adsorption rate, k{sub 2}, is observed onto UMS and strongly depends on pH. • Film diffusion was the likely rate-limiting step in the adsorption process.

  2. Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Surface/Near Surface Indication - Characterization of Surface Anomalies from Magnetic Particle and Liquid Penetrant Indications

    SciTech Connect (OSTI)

    Griffin, John [university of Alabama - Birmingham] [university of Alabama - Birmingham

    2014-02-20T23:59:59.000Z

    The systematic study and characterization of surface indications has never been conducted. Producers and users of castings do not have any data on which they can reliably communicate the nature of these indications or their effect on the performance of parts. Clearly, the ultimate intent of any work in this area is to eliminate indications that do in fact degrade properties. However, it may be impractical physically and/or financially to eliminate all surface imperfections. This project focused on the ones that actually degrade properties. The initial work was to identify those that degrade properties. Accurate numerical simulations of casting service performance allow designers to use the geometric flexibility of castings and the superior properties of steel to produce lighter weight and more energy efficient components for transportation systems (cars and trucks), construction, and mining. Accurate simulations increase the net melting energy efficiency by improving casting yield and reducing rework and scrap. Conservatively assuming a 10% improvement in yield, approximately 1.33 x 1012 BTU/year can be saved with this technology. In addition, CO2 emissions will be reduced by approximately 117,050 tons per year.

  3. Final Report Theoretical Studies of Surface Reactions on Metals and Electronic Materials

    SciTech Connect (OSTI)

    Jerry L. Whitten

    2012-04-23T23:59:59.000Z

    This proposal describes the proposed renewal of a theoretical research program on the structure and reactivity of molecules adsorbed on transition metal surfaces. A new direction of the work extends investigations to interfaces between solid surfaces, adsorbates and aqueous solutions and includes fundamental work on photoinduced electron transport into chemisorbed species and into solution. The goal is to discover practical ways to reduce water to hydrogen and oxygen using radiation comparable to that available in the solar spectrum. The work relates to two broad subject areas: photocatalytic processes and production of hydrogen from water. The objective is to obtain high quality solutions of the electronic structure of adsorbate-metal-surface-solution systems so as to allow activation barriers to be calculated and reaction mechanisms to be determined. An ab initio embedding formalism provides a route to the required accuracy. New theoretical methods developed during the previous grant period will be implemented in order to solve the large systems involved in this work. Included is the formulation of a correlation operator that is used to treat localized electron distributions such as ionic or regionally localized distributions. The correlation operator which is expressed as a two-particle projector is used in conjunction with configuration interaction.

  4. Emissivity of Candidate Materials for VHTR Applicationbs: Role of Oxidation and Surface Modification Treatments

    SciTech Connect (OSTI)

    Sridharan, Kumar; Allen, Todd; Anderson, Mark; Cao, Guoping; Kulcinski, Gerald

    2011-07-25T23:59:59.000Z

    The Generation IV (GEN IV) Nuclear Energy Systems Initiative was instituted by the Department of Energy (DOE) with the goal of researching and developing technologies and materials necessary for various types of future reactors. These GEN IV reactors will employ advanced fuel cycles, passive safety systems, and other innovative systems, leading to significant differences between these future reactors and current water-cooled reactors. The leading candidate for the Next Generation Nuclear Plant (NGNP) to be built at Idaho National Lab (INL) in the United States is the Very High Temperature Reactor (VHTR). Due to the high operating temperatures of the VHTR, the Reactor Pressure Vessel (RPV) will partially rely on heat transfer by radiation for cooling. Heat expulsion by radiation will become all the more important during high temperature excursions during off-normal accident scenarios. Radiant power is dictated by emissivity, a material property. The NGNP Materials Research and Development Program Plan [1] has identified emissivity and the effects of high temperature oxide formation on emissivity as an area of research towards the development of the VHTR.

  5. Establishing material properties for thin asphalt concrete surfaces on granular bases

    E-Print Network [OSTI]

    Rosson, Barry Thomas

    1985-01-01T23:59:59.000Z

    cross-section of a Goodyear Hi -Miler 10. 00-20 14-ply bias truck tire carcass was obtained; the input data for the Tielking tire model was developed by measuring cord locations, angles, and plies on a section of the tire; and the tire pressure.... Since little work in the past has been done in the area of thin asphalt concrete surface analysis, re-evaluation of several assumptions concerning the tire load were necessary. The truck tire pressures on Texas highways have dramatically increased...

  6. GUIDANCE FOR THE PROPER CHARACTERIZATION AND CLASSIFICATION OF LOW SPECIFIC ACTIVITY MATERIALS AND SURFACE CONTAMINATED OBJECTS FOR DISPOSAL

    SciTech Connect (OSTI)

    PORTSMOUTH JH; BLACKFORD LT

    2012-02-13T23:59:59.000Z

    Regulatory concerns over the proper characterization of certain waste streams led CH2M HILL Plateau Remediation Company (CHPRC) to develop written guidance for personnel involved in Decontamination & Decommissioning (D&D) activities, facility management and Waste Management Representatives (WMRs) involved in the designation of wastes for disposal on and off the Hanford Site. It is essential that these waste streams regularly encountered in D&D operations are properly designated, characterized and classified prior to shipment to a Treatment, Storage or Disposal Facility (TSDF). Shipments of waste determined by the classification process as Low Specific Activity (LSA) or Surface Contaminated Objects (SCO) must also be compliant with all applicable U.S. Department of Transportation (DOE) regulations as well as Department of Energy (DOE) orders. The compliant shipment of these waste commodities is critical to the Hanford Central Plateau cleanup mission. Due to previous problems and concerns from DOE assessments, CHPRC internal critiques as well as DOT, a management decision was made to develop written guidance and procedures to assist CHPRC shippers and facility personnel in the proper classification of D&D waste materials as either LSA or SCO. The guidance provides a uniform methodology for the collection and documentation required to effectively characterize, classify and identify candidate materials for shipping operations. A primary focus is to ensure that waste materials generated from D&D and facility operations are compliant with the DOT regulations when packaged for shipment. At times this can be difficult as the current DOT regulations relative to the shipment of LSA and SCO materials are often not clear to waste generators. Guidance is often sought from NUREG 1608/RAMREG-003 [3]: a guidance document that was jointly developed by the DOT and the Nuclear Regulatory Commission (NRC) and published in 1998. However, NUREG 1608 [3] is now thirteen years old and requires updating to comply with the newer DOT regulations. Similar challenges present themselves throughout the nuclear industry in both commercial and government operations and therefore, this is not only a Hanford Site problem. Shipping radioactive wastes as either LSA or SCO rather than repacking it is significantly cheaper than other DOT radioactive materials shipping classifications particularly when the cost of packages is included. Additionally, the need to 'repackage' materials for transport can often increase worker exposure, necessitated by 'repackaging' waste materials into DOT 7 A Type A containers.

  7. Predicted giant magnetic moment on non-{n0m} surfaces of d-wave superconductors

    E-Print Network [OSTI]

    Hu, Chia-Ren; Yan, XZ.

    1999-01-01T23:59:59.000Z

    supported the con- clusion that the ZBCP?s observed in them are due to such PRB 600163-1829/99/60~18!/12573~4!/$15.00 0m? surfaces of d-wave superconductors n Hu , College Station, Texas 77843-4242 g Yan , College Station, Texas 77843-4242 , P. O...!. We also assume that the carriers are electrons with charge 2e ,0 and a gyromagnetic ratio g52ge/2mec with g52. Later we will comment on the effects of replacing these as- sumptions by more realistic ones, such as a three- dimensional band...

  8. Journal of Magnetism and MagneticMaterials 148 (1995) 40-41 studies of bct Fe(100)p(1 1)/Pd(100) films

    E-Print Network [OSTI]

    Rau, Carl

    transitions in low dimensions, but also from the recent interest in the devel- opment of novel and sophisticated electronic and magnetic devices of dimensions in the nanometer range which re- quires oscillatory ferromagnetic exchange coupling be- tween magnetic layers separated by nonmagnetic spacer layers

  9. Interplay of superconductivity, magnetism, and density waves in rare-earth tritellurides and iron-based superconducting materials

    E-Print Network [OSTI]

    Zocco, Diego Andrés

    2011-01-01T23:59:59.000Z

    B. Superconductivity . . . . . . . . . . . . . . . . .IV Superconductivity and Magnetism in Iron-PnictideSearch for Pressure Induced Superconductivity in Undoped Ce-

  10. Surface Anchoring of Nematic Phase on Carbon Nanotubes: Nanostructure of Ultra-High Temperature Materials

    SciTech Connect (OSTI)

    Ogale, Amod A

    2012-04-27T23:59:59.000Z

    Nuclear energy is a dependable and economical source of electricity. Because fuel supply sources are available domestically, nuclear energy can be a strong domestic industry that can reduce dependence on foreign energy sources. Commercial nuclear power plants have extensive security measures to protect the facility from intruders [1]. However, additional research efforts are needed to increase the inherent process safety of nuclear energy plants to protect the public in the event of a reactor malfunction. The next generation nuclear plant (NGNP) is envisioned to utilize a very high temperature reactor (VHTR) design with an operating temperature of 650-1000�°C [2]. One of the most important safety design requirements for this reactor is that it must be inherently safe, i.e., the reactor must shut down safely in the event that the coolant flow is interrupted [2]. This next-generation Gen IV reactor must operate in an inherently safe mode where the off-normal temperatures may reach 1500�°C due to coolant-flow interruption. Metallic alloys used currently in reactor internals will melt at such temperatures. Structural materials that will not melt at such ultra-high temperatures are carbon/graphtic fibers and carbon-matrix composites. Graphite does not have a measurable melting point; it is known to sublime starting about 3300�°C. However, neutron radiation-damage effects on carbon fibers are poorly understood. Therefore, the goal of this project is to obtain a fundamental understanding of the role of nanotexture on the properties of resulting carbon fibers and their neutron-damage characteristics. Although polygranular graphite has been used in nuclear environment for almost fifty years, it is not suitable for structural applications because it do not possess adequate strength, stiffness, or toughness that is required of structural components such as reaction control-rods, upper plenum shroud, and lower core-support plate [2,3]. For structural purposes, composites consisting of strong carbon fibers embedded in a carbon matrix are needed. Such carbon/carbon (C/C) composites have been used in aerospace industry to produce missile nose cones, space shuttle leading edge, and aircraft brake-pads. However, radiation-tolerance of such materials is not adequately known because only limited radiation studies have been performed on C/C composites, which suggest that pitch-based carbon fibers have better dimensional stability than that of polyacrylonitrile (PAN) based fibers [4]. The thermodynamically-stable state of graphitic crystalline packing of carbon atoms derived from mesophase pitch leads to a greater stability during neutron irradiation [5]. The specific objectives of this project were: (i) to generating novel carbonaceous nanostructures, (ii) measure extent of graphitic crystallinity and the extent of anisotropy, and (iii) collaborate with the Carbon Materials group at Oak Ridge National Lab to have neutron irradiation studies and post-irradiation examinations conducted on the carbon fibers produced in this research project.

  11. SURFACE-MODIFIED FERRITIC INTERCONNECT MATERIALS FOR SOLID OXIDE FUEL CELLS

    SciTech Connect (OSTI)

    Bruce R. Lanning; James Arps; Ronghua Wei; Goeff Dearnaley

    2004-03-15T23:59:59.000Z

    Interconnects are a critical element of an SOFC assembly and although much work has focused on chromium and chromium-iron alloys containing an oxide that is both oxidation resistant and electrically conductive, the thermal instability of typical native metal oxides allow interdiffusion of cations across the interconnect-electrode boundary that ultimately leads to degradation of SOFC performance. Phase I of the SECA Core Technology Program has been a one-year effort to investigate and evaluate the feasibility of: (1) Ion implanting an alumina-scale forming ferritic steel, such as FeCrAlY, to form an interconnect material with low resistance (< 0.1 {Omega}/cm{sup 2}) in oxidizing/reducing environments up to 800 C, and (2) Maintaining the above low resistance metric for an extended time (> 1000 hours at 800 C) in contact with an LSF cathode material. We confirmed, as part of our oxidation kinetics evaluation of FeCrAlY and 430 ferritic steel, the parabolic growth of a mixed chromia/alumina scale on FeCrAlY and a single chromia layer in the case of the 430 stainless steel; the outer contiguous layer of Al{sub 2}O{sub 3}, in the case of FeCrAlY, forming a stable, self-limiting, protective scale with no detectable cation interdiffusion between FeCrAlY and an LSF electrode even after 1000 hours at 800 C in air. To render the alumina scale conductive, we implanted either titanium or niobium ions into FeCrAlY scales to a fixed depth (0.12 {micro}m), varying only the thickness of the oxide. ASR for an un-doped FeCrAlY oxide scale (i.e., alumina) was more than an order of magnitude greater than the 430 control sample whereas, the ASR for the doped FeCrAlY oxide scale sample was comparable to the 430 control sample; hence, the resistance of a doped alumina scale on FeCrAlY was equal to the resistance of a chromia-scale forming alloy, such as 430 (chromia scales of which are typically < 0.1 {Omega}-cm). Along with the ASR measurements, AC impedance measurements were conducted to evaluate conduction mechanisms. From the AC impedance measurements, we observed that the addition of niobium resulted in at least a two order of magnitude reduction in resistance over the un-doped specimen and that the conduction in the doped alumina scale was pure electronic conduction, as opposed to mixed ionic-electronic conduction (dominated by intrinsic (ionic) defects) for the un-doped alumina scales. The DC resistance component was {approx}4 {Omega} although when this value is adjusted to account for the system resistance (i.e., leads, junctions, etc.), the ASR was determined to be < 0.1 {Omega}-cm; even after 1000 hours at 800 C in air. Our results have clearly shown that dopant additions increase the electronic conductivity of alumina forming scale alloys, such as FeCrAlY, transforming from a mixed ionic/electronic conduction mechanism. Just as importantly, the demonstrated stable formation of an alumina scale was shown to be an advantage over conventional pure chromia forming alloys as interconnect materials.

  12. Magnetic transitions driven by temperature in surface oxidized Co{sub 0.10}Ni{sub 0.90}/Cu(001) ultrathin films

    SciTech Connect (OSTI)

    Shih, Ying-Ta; Shen, Wen-He; Lee, Kuo-Long; Pan, Wei, E-mail: weipane@gmail.com [Department of Physics, National Chung Cheng University, Min-Hsiung, Chia-Yi 621, Taiwan (China)] [Department of Physics, National Chung Cheng University, Min-Hsiung, Chia-Yi 621, Taiwan (China)

    2014-01-15T23:59:59.000Z

    The magnetization of Co{sub 0.10}Ni{sub 0.90}/Cu(001) films before and after surface oxidization at 300 K is presented. Before the oxidization, the magnetization of the films in the thickness of 11 to 20 monolayers (ML) is in the in-plane direction at the temperature ranging from 140 K to 300 K. After the oxidization, the magnetizations of the films are in the in-plane direction at the temperature above 200 K, but transit to magnetization demolishment, in-plane-and-out-of-plane co-existence, spin reorientation transition, and coercivity enhancement, for films of 11, 12, 13, and above 15 ML, respectively. The blocking temperature of this film is also 200 K, which implies the transitions might be driven by the ordering of the antiferromagnetic surface oxides. The various magnetizations provide a model system for manipulating the magnetization direction, as well as a spin valve device by combination of the oxidized films.

  13. Monte Carlo characterization of skin doses in 6 MV transverse field MRI-linac systems: Effect of field size, surface orientation, magnetic field strength, and exit bolus

    SciTech Connect (OSTI)

    Oborn, B. M.; Metcalfe, P. E.; Butson, M. J.; Rosenfeld, A. B. [Illawarra Cancer Care Centre (ICCC), Wollongong, New South Wales 2500 (Australia) and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, New South Wales 2500 (Australia); Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, New South Wales 2500 (Australia); Illawarra Cancer Care Centre (ICCC), Wollongong, New South Wales 2500 (Australia); Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, New South Wales 2500 (Australia)

    2010-10-15T23:59:59.000Z

    Purpose: The main focus of this work is to continue investigations into the Monte Carlo predicted skin doses seen in MRI-guided radiotherapy. In particular, the authors aim to characterize the 70 {mu}m skin doses over a larger range of magnetic field strength and x-ray field size than in the current literature. The effect of surface orientation on both the entry and exit sides is also studied. Finally, the use of exit bolus is also investigated for minimizing the negative effects of the electron return effect (ERE) on the exit skin dose. Methods: High resolution GEANT4 Monte Carlo simulations of a water phantom exposed to a 6 MV x-ray beam (Varian 2100C) have been performed. Transverse magnetic fields of strengths between 0 and 3 T have been applied to a 30x30x20 cm{sup 3} phantom. This phantom is also altered to have variable entry and exit surfaces with respect to the beam central axis and they range from -75 deg. to +75 deg. The exit bolus simulated is a 1 cm thick (water equivalent) slab located on the beam exit side. Results: On the entry side, significant skin doses at the beam central axis are reported for large positive surface angles and strong magnetic fields. However, over the entry surface angle range of -30 deg. to -60 deg., the entry skin dose is comparable to or less than the zero magnetic field skin dose, regardless of magnetic field strength and field size. On the exit side, moderate to high central axis skin dose increases are expected except at large positive surface angles. For exit bolus of 1 cm thickness, the central axis exit skin dose becomes an almost consistent value regardless of magnetic field strength or exit surface angle. This is due to the almost complete absorption of the ERE electrons by the bolus. Conclusions: There is an ideal entry angle range of -30 deg. to -60 deg. where entry skin dose is comparable to or less than the zero magnetic field skin dose. Other than this, the entry skin dose increases are significant, especially at higher magnetic fields. On the exit side there is mostly moderate to high skin dose increases for 0.2-3 T with the only exception being large positive angles. Exit bolus of 1 cm thickness will have a significant impact on lowering such exit skin dose increases that occur as a result of the ERE.

  14. Thin Films: Anisotropy and Surface Effects Brett Heinrich, Chairman Growth and magnetic properties of Fe films on vicinal to ,,001... substrates

    E-Print Network [OSTI]

    Demokritov, S.O.

    of Physics. S0021-8979 00 50708-7 The magnetic properties of ultrathin 3d transition metal films have been of the electron energy Figs. 1 a and 1 b . This is a finger print of an ordered step structure on the surface energy electron diffraction, x-ray diffraction, second harmonic generation SHG , as well as the Brillouin

  15. BREAKDOWN OF THE MAGNETIC SURFACE BARRIER IN NIOBIUM BY OXYGEN DIFFUSION G.P. van der Mey, P.H. Kes and D. de Klerk.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    BREAKDOWN OF THE MAGNETIC SURFACE BARRIER IN NIOBIUM BY OXYGEN DIFFUSION G.P. van der Mey, P.H. Kes versus temperature on niobium oxidized at 330 and 200°C showed the existence of a diffusion zone irre- versibility. 1. THE OXYGEN PROFILE.- Oxidation of pure niobium at 400°C for 10 s has been applied

  16. Organic Light-Emitting Diodes (OLEDs) and Optically-Detected Magnetic Resonance (ODMR) studies on organic materials

    SciTech Connect (OSTI)

    Cai, Min

    2011-11-30T23:59:59.000Z

    Organic semiconductors have evolved rapidly over the last decades and currently are considered as the next-generation technology for many applications, such as organic light-emitting diodes (OLEDs) in flat-panel displays (FPDs) and solid state lighting (SSL), and organic solar cells (OSCs) in clean renewable energy. This dissertation focuses mainly on OLEDs. Although the commercialization of the OLED technology in FPDs is growing and appears to be just around the corner for SSL, there are still several key issues that need to be addressed: (1) the cost of OLEDs is very high, largely due to the costly current manufacturing process; (2) the efficiency of OLEDs needs to be improved. This is vital to the success of OLEDs in the FPD and SSL industries; (3) the lifetime of OLEDs, especially blue OLEDs, is the biggest technical challenge. All these issues raise the demand for new organic materials, new device structures, and continued lower-cost fabrication methods. In an attempt to address these issues, we used solution-processing methods to fabricate highly efficient small molecule OLEDs (SMOLEDs); this approach is costeffective in comparison to the more common thermal vacuum evaporation. We also successfully made efficient indium tin oxide (ITO)-free SMOLEDs to further improve the efficiency of the OLEDs. We employed the spin-dependent optically-detected magnetic resonance (ODMR) technique to study the luminescence quenching processes in OLEDs and organic materials in order to understand the intrinsic degradation mechanisms. We also fabricated polymer LEDs (PLEDs) based on a new electron-accepting blue-emitting polymer and studied the effect of molecular weight on the efficiency of PLEDs. All these studies helped us to better understand the underlying relationship between the organic semiconductor materials and the OLEDs’ performance, and will subsequently assist in further enhancing the efficiency of OLEDs. With strongly improved device performance (in addition to other OLEDs' attributes such as mechanical flexibility and potential low cost), the OLED technology is promising to successfully compete with current technologies, such as LCDs and inorganic LEDs.

  17. Is the friction angle the maximum slope of a free surface of a non cohesive material?

    E-Print Network [OSTI]

    A. Modaressi; P. Evesque

    2005-07-13T23:59:59.000Z

    Starting from a symmetric triangular pile with a horizontal basis and rotating the basis in the vertical plane, we have determined the evolution of the stress distribution as a function of the basis inclination using Finite Elements method with an elastic-perfectly plastic constitutive model, defined by its friction angle, without cohesion. It is found that when the yield function is the Drucker-Prager one, stress distribution satisfying equilibrium can be found even when one of the free-surface slopes is larger than the friction angle. This means that piles with a slope larger than the friction angle can be (at least) marginally stable and that slope rotation is not always a destabilising perturbation direction. On the contrary, it is found that the slope cannot overpass the friction angle when a Mohr-Coulomb yield function is used. Theoretical explanation of these facts is given which enlightens the role plaid by the intermediate principal stress in both cases of the Mohr-Coulomb criterion and of the Drucker-Prager one. It is then argued that the Mohr-Coulomb criterion assumes a spontaneous symmetry breaking, as soon as the two smallest principal stresses are different ; this is not physical most likely; so this criterion shall be replaced by a Drucker-Prager criterion in the vicinity of the equality, which leads to the previous anomalous behaviour ; so these numerical computations enlighten the avalanche process: they show that no dynamical angle larger than the static one is needed to understand avalanching. It is in agreement with previous experimental results. Furthermore, these results show that the maximum angle of repose can be modified using cyclic rotations; we propose a procedure that allows to achieve a maximum angle of repose to be equal to the friction angle .

  18. Control of Surface Mounted Permanent Magnet Motors with Special Application to Fractional-Slot Concentrated Windings

    SciTech Connect (OSTI)

    Lawler, J.S.

    2005-12-21T23:59:59.000Z

    It is well known that the ability of the permanent magnet synchronous machine (PMSM) to operate over a wide constant power speed range (CPSR) is dependent upon the machine inductance [1,2,3,4,5]. Early approaches for extending CPSR operation included adding supplementary inductance in series with the motor [1] and the use of anti-parallel thyristor pairs in series with the motor-phase windings [5]. The increased inductance method is compatible with a voltage-source inverter (VSI) controlled by pulse-width modulation (PWM) which is called the conventional phase advance (CPA) method. The thyristor method has been called the dual mode inverter control (DMIC). Neither of these techniques has met with wide acceptance since they both add cost to the drive system and have not been shown to have an attractive cost/benefit ratio. Recently a method has been developed to use fractional-slot concentrated windings to significantly increase the machine inductance [6]. This latest approach has the potential to make the PMSM compatible with CPA without supplemental external inductance. If the performance of such drive is acceptable, then the method may make the PMSM an attractive option for traction applications requiring a wide CPSR. A 30 pole, 6 kW, 6000 maximum revolutions per minute (rpm) prototype of the fractional-slot PMSM design has been developed [7]. This machine has significantly more inductance than is typical of regular PMSMs. The prototype is to be delivered in late 2005 to the Oak Ridge National Laboratory (ORNL) for testing and development of a suitable controller. In advance of the test/control development effort, ORNL has used the PMSM models developed over a number of previous studies to study the steady-state performance of high-inductance PMSM machines with a view towards control issues. The detailed steady-state model developed includes all motor and inverter-loss mechanisms and will be useful in assessing the performance of the dynamic controller to be developed in future work. This report documents the results of this preliminary investigation.

  19. The Nature of the Distinctive Microscopic Features in R5(SixGe1-x)4 Magnetic Refrigeration Materials

    SciTech Connect (OSTI)

    Ozan Ugurlu

    2006-05-01T23:59:59.000Z

    Magnetic refrigeration is a promising technology that offers a potential for high energy efficiency. The giant magnetocaloric effect of the R{sub 5}(Si{sub x}, Ge{sub 1-x}){sub 4} alloys (where R=rare-earth and O {le} x {le} 1), which was discovered in 1997, make them perfect candidates for magnetic refrigeration applications. In this study the microstructures of Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} alloys have been characterized using electron microscopy techniques, with the focus being on distinctive linear features first examined in 1999. These linear features have been observed in R{sub 5}(Si{sub x}, Ge{sub 1-x}){sub 4} alloys prepared from different rare-earths (Gd, Tb, Dy and Er) with different crystal structures (Gd{sub 5}Si{sub 4}-type orthorhombic, monoclinic and Gd{sub 5}Ge{sub 4}-type orthorhombic). Systematic scanning electron microscope studies revealed that these linear features are actually thin-plates, which grow along specific directions in the matrix material. The crystal structure of the thin-plates has been determined as hexagonal with lattice parameters a=b=8.53 {angstrom} and c=6.40 {angstrom} using selected area diffraction (SAD). Energy dispersive spectroscopy analysis, carried out in both scanning and transmission electron microscopes, showed that the features have a composition approximating to R{sub 5}(Si{sub x},Ge{sub 1-x}){sub 3}.phase. Orientation relationship between the matrix and the thin-plates has been calculated as [- 1010](1-211){sub p}//[010](10-2){sub m}. The growth direction of the thin plates are calculated as (22 0 19) and (-22 0 19) by applying the Ag approach of Zhang and Purdy to the SAD patterns of this system. High Resolution TEM images of the Gd{sub 5}Ge{sub 4} were used to study the crystallographic relationship. A terrace-ledge structure was observed at the interface and a 7{sup o} rotation of the reciprocal lattices with respect to each other, consistent with the determined orientation relationship, was noted. Both observations are consistent with the stated hypothesis that the growth direction of the thin-plates is parallel to an invariant line direction. Based on the terrace-ledge structure of the thin-plate interface a displacive-diffusional growth mechanism has been proposed to explain the rapid formation of the R{sub 5}(Si{sub x},Ge{sub 1-x}){sub 3} plates.

  20. Method for depositing a uniform layer of particulate material on the surface of an article having interconnected porosity

    DOE Patents [OSTI]

    Wrenn, G.E. Jr.; Lewis, J. Jr.

    1982-09-29T23:59:59.000Z

    The invention is a method for depositing liquid-suspended particles on an immersed porous article characterized by interconnected porosity. In one form of the invention, coating is conducted in a vessel containing an organic liquid supporting a colloidal dispersion of graphite sized to lodge in surface pores of the article. The liquid comprises a first volatile component (e.g., acetone) and a second less-volatile component (e.g., toluene) containing a dissolved organic graphite-bonding agent. The liquid also contains an organic agent (e.g., cellulose gum) for maintaining the particles in suspension. A porous carbon article to be coated is immersed in the liquid so that it is permeated therewith. While the liquid is stirred to maintain a uniform blend, the vessel headspace is evacuated to effect flashing-off of the first component from the interior of the article. This causes particle-laden liquid exterior of the article to flow inwardly through its surface pores, lodging particles in these pores and forming a continuous graphite coating. The coated article is retrieved and heated to resin-bond the graphite. The method can be used to form a smooth, adherent, continuous coating of various materials on various porous articles. The method is rapid and reproducible.

  1. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, J.A.; Stone, R.R.; Fabyan, J.

    1985-02-12T23:59:59.000Z

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

  2. Mossbauer spectroscopic and x-ray diffraction studies of FeSiO2 nanocomposite soft magnetic materials

    E-Print Network [OSTI]

    Yang, De-Ping

    Mo¨ssbauer spectroscopic and x-ray diffraction studies of FeÕSiO2 nanocomposite soft magnetic. The compositions of the precursor and the successive heat-treated samples have been investigated by 57 Fe Mo¨ssbauer a synthesis of Fe/SiO2 nanocomposites and a study of their magnetic and structural properties using Mo¨ssbauer

  3. A garden mulch is any material spread on the soil surface to modify the environment where the plant is growing. The materials used can be natural or synthetic and can be used in any number of combinations

    E-Print Network [OSTI]

    New Hampshire, University of

    companies manufacture recycled paper into mulch, sold in rolls and installed much like black plastic. OtherA garden mulch is any material spread on the soil surface to modify the environment where the plant within a single garden or around a homestead. The proper selection and use of a mulch will result

  4. Magnetic investigations

    SciTech Connect (OSTI)

    Bath, G.D.; Jahren, C.E.; Rosenbaum, J.G. [Geological Survey, Denver, CO (USA); Baldwin, M.J. [Fenix and Scisson, Inc., Mercury, NV (USA)

    1983-12-31T23:59:59.000Z

    Air and ground magnetic anomalies in the Climax stock area of the NTS help define the gross configuration of the stock and detailed configuration of magnetized rocks at the Boundary and Tippinip faults that border the stock. Magnetizations of geologic units were evaluated by measurements of magnetic properties of drill core, minimum estimates of magnetizations from ground magnetic anomalies for near surface rocks, and comparisons of measured anomalies with anomalies computed by a three-dimensional forward program. Alluvial deposits and most sedimentary rocks are nonmagnetic, but drill core measurements reveal large and irregular changes in magnetization for some quartzites and marbles. The magnetizations of quartz monzonite and granodiorite near the stock surface are weak, about 0.15 A/m, and increase at a rate of 0.00196 A/m/m to 1.55 A/m, at depths greater than 700 m (2300 ft). The volcanic rocks of the area are weakly magnetized. Aeromagnetic anomalies 850 m (2800 ft) above the stock are explained by a model consisting of five vertical prisms. Prisms 1, 2, and 3 represent the near surface outline of the stock, prism 4 is one of the models developed by Whitehill (1973), and prism 5 is modified from the model developed by Allingham and Zietz (1962). Most of the anomaly comes from unsampled and strongly-magnetized deep sources that could be either granite or metamorphosed sedimentary rocks. 48 refs., 23 figs., 3 tabs.

  5. Breaking symmetries in ordered materials : spin polarized light transport in magnetized noncentrosymmetric 1D photonic crystals, and photonic gaps and fabrication of quasiperiodic structured materials from interference lithography

    E-Print Network [OSTI]

    Bita, Ion

    2006-01-01T23:59:59.000Z

    Effects of breaking various symmetries on optical properties in ordered materials have been studied. Photonic crystals lacking space-inversion and time-reversal symmetries were shown to display nonreciprocal dispersion ...

  6. Magnetic nanotubes

    DOE Patents [OSTI]

    Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)

    2010-11-16T23:59:59.000Z

    A magnetic nanotube includes bacterial magnetic nanocrystals contacted onto a nanotube which absorbs the nanocrystals. The nanocrystals are contacted on at least one surface of the nanotube. A method of fabricating a magnetic nanotube includes synthesizing the bacterial magnetic nanocrystals, which have an outer layer of proteins. A nanotube provided is capable of absorbing the nanocrystals and contacting the nanotube with the nanocrystals. The nanotube is preferably a peptide bolaamphiphile. A nanotube solution and a nanocrystal solution including a buffer and a concentration of nanocrystals are mixed. The concentration of nanocrystals is optimized, resulting in a nanocrystal to nanotube ratio for which bacterial magnetic nanocrystals are immobilized on at least one surface of the nanotubes. The ratio controls whether the nanocrystals bind only to the interior or to the exterior surfaces of the nanotubes. Uses include cell manipulation and separation, biological assay, enzyme recovery, and biosensors.

  7. Ultra-high speed permanent magnet axial gap alternator with multiple stators

    DOE Patents [OSTI]

    Hawsey, Robert A. (Oak Ridge, TN); Bailey, J. Milton (Knoxville, TN)

    1991-01-01T23:59:59.000Z

    An ultra-high speed, axial gap alternator that can provide an output to a plurality of loads, the alternator providing magnetic isolation such that operating conditions in one load will not affect operating conditions of another load. This improved alternator uses a rotor member disposed between a pair of stator members, with magnets disposed in each of the rotor member surfaces facing the stator members. The magnets in one surface of the rotor member, which alternate in polarity, are isolated from the magnets in the other surface of the rotor member by a disk of magnetic material disposed between the two sets of magents. In the preferred embodiment, this disk of magnetic material is laminated between two layers of non-magnetic material that support the magnets, and the magnetic material has a peripheral rim that extends to both surfaces of the rotor member to enhance the structural integrity. The stator members are substantially conventional in construction in that equally-spaced and radially-oriented slots are provided, and winding members are laid in these slots. A unit with multiple rotor members and stator members is also described.

  8. Patterned Magnetic Nanostructures and Quantized Magnetic Disks

    E-Print Network [OSTI]

    -increasing demands in data storage and to new applications of magnetic devices in the field of sensors. NewPatterned Magnetic Nanostructures and Quantized Magnetic Disks STEPHEN Y. CHOU Invited Paper, opens up new opportunities for engineering innovative magnetic materials and devices, developing ultra

  9. Chemically diverse polymer microarrays and high throughput surface characterisation: a method for discovery of materials for stem cell culture

    E-Print Network [OSTI]

    Celiz, A. D.

    Materials discovery provides the opportunity to identify novel materials that are tailored to complex biological environments by using combinatorial mixing of monomers to form large libraries of polymers as micro arrays. ...

  10. 2260 IEEE TRANSACTIONS ON MAGNETICS, VOL. 46, NO. 6, JUNE 2010 Characterization of Oxide Materials for Exchange

    E-Print Network [OSTI]

    Laughlin, David E.

    , and David E. Laughlin1 Department of Materials Science & Engineering, DSSC, Carnegie Mellon University, Pittsburgh, PA 15213 USA Department of Electrical & Computer Engineering, DSSC, Carnegie Mellon University

  11. Magnets & Magnet Condensed Matter Science

    E-Print Network [OSTI]

    McQuade, D. Tyler

    18 No. 1 CONDENSED MATTER SCIENCE Technique development, graphene, magnetism & magnetic materials Pressure 9 Metal to Insulator Transition on the N=0 Landau Level in Graphene 10 Evidence for Fractional Quantum Hall States in Suspended Bilayer and Trilayer Graphene 11 Fractional Quantum Hall Effect

  12. Magnetorheological materials, method for making, and applications thereof

    DOE Patents [OSTI]

    Shen, Rui; Yang, Hong; Shafrir, Shai N.; Miao, Chunlin; Wang, Mimi; Mici, Joni; Lambropoulos, John C.; Jacobs, Stephen D.

    2014-08-19T23:59:59.000Z

    A magnetorheological material comprises a magnetic particle and a ceramic material, wherein the magnetorheological material is in a dried form and further wherein a portion of the ceramic material is in the form of a nanocrystalline coating over the entire exterior surface of the magnetic particle and another portion of the ceramic material is in the form of a free nanocrystal. A magnetorheological material comprises a magnetic particle having a ceramic material coating over an external surface thereof as a result of a coating process, and a free nanocrystal of the ceramic material in the form of a residual by-product of the coating process. A sol-gel process for making a magnetorheological product comprises providing a sol of a desired ceramic coating material; combining a desired quantity of carbonyl iron (CI) particles with the sol to coat the CI particles with the ceramic coating material; creating a resulting quantity of nanocrystalline ceramic material-coated CI particles and a quantity of free nanocrystals of the ceramic material; and, drying the resulting quantity of coated CI particles and free nanocrystals to a moisture content equal to or less than 2 wt %.

  13. Photoemission Spectroscopy of Magnetic and Nonmagnetic Impurities on the Surface of the Bi2Se3 Topological Insulator

    E-Print Network [OSTI]

    Ohta, Shigemi

    Topological Insulator T. Valla,1,* Z.-H. Pan,1 D. Gardner,2 Y. S. Lee,2 and S. Chu3 1 Condensed Matter Physics; published 12 March 2012) Dirac-like surface states on surfaces of topological insulators have a chiral spin impurities on the surface of Bi2Se3, a model topological insulator. We reveal a remarkable insensitivity

  14. Nuclear magnetic resonance: Its role as a microscopic probe of the electronic and magnetic properties of High-{Tc} superconductors and related materials

    SciTech Connect (OSTI)

    Suh, Byoung Jin

    1995-12-27T23:59:59.000Z

    NMR experiments are reported for Sr{sub 2}CuO{sub 2}Cl{sub 2}, HgBa{sub 2}CuO{sub 4+d}, YNi{sub 2}B{sub 2}C and YBa{sub 2}Cu{sub 3}O{sub 7}. NMR studies typify three different aspects of microscopic properties of HTSC. In non-superconducting antiferromagnetic (AF) prototype Sr{sub 2}CuO{sub 2}Cl{sub 2}, we used NMR to investigate Cu{sup 2+} correlated spin dynamics and AF phase transition in CuO2 layers. In the superconductors, we used NMR both to investigate the electronic properties of the Fermi-liquid in normal and superconducting states and to investigate flux lattice and flux-line dynamics in the superconducting state in presence of magnetic field. A summary of each study is given: {sup 35}Cl NMR was measured in Sr{sub 2}CuO{sub 2}Cl{sub 2} single crystals with T{sub N}=257K. {sub 35}Cl NMR relaxation rates showed crossover of Cu{sup 2+} spin dynamics from Heisenberg to XY-like correlation at 290 K well above T{sub N}. A field-dependent T{sub N} for H{perpendicular}c was observed and explained by a field-induced Ising-like anisotropy in ab plane. {sup 199}Hg NMR was measured in HgBa{sub 2}CuO{sub 4+d}. Properties of the Fermi-liquid are characterized by a single-spin fluid picture and opening of a spin pseudo-gap at q=0 above {Tc}. Below {Tc}, spin component of Knight shift decreases rapidly in agreement with prediction for d-wave pairing scheme. {sup 11}B and {sup 89}Y NMR/magnetization were measured in YNi{sub 2}B{sub 2}C. Temperature dependence of {sup 11}B Knight shift and of the NSLR gave a normal state which agrees with the Korringa relation, indicating that the AF fluctuations on the Ni sublattice are negligible. Opening of the superconducting gap obeys BCS. A NMR approach to investigate vortex thermal motion in HTSC is presented, based on contribution of thermal flux-lines motion to both T{sub 2}{sup {minus}1} and T{sub 1}{sup {minus}1}. Effects are demonstrated in YBa{sub 2}Cu{sub 3}O{sub 7} and HgBa{sub 2}CuO{sub 4+d}.

  15. Magnetically attached sputter targets

    DOE Patents [OSTI]

    Makowiecki, D.M.; McKernan, M.A.

    1994-02-15T23:59:59.000Z

    An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.

  16. Magnetic nanohole superlattices

    DOE Patents [OSTI]

    Liu, Feng

    2013-05-14T23:59:59.000Z

    A magnetic material is disclosed including a two-dimensional array of carbon atoms and a two-dimensional array of nanoholes patterned in the two-dimensional array of carbon atoms. The magnetic material has long-range magnetic ordering at a temperature below a critical temperature Tc.

  17. Enhanced heat transfer through filler-polymer interface by surface-coupling agent in heat-dissipation material: A non-equilibrium molecular dynamics study

    SciTech Connect (OSTI)

    Tanaka, Kouichi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan); Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Kitsunezuka, Masashi; Shinma, Atsushi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan)

    2013-11-21T23:59:59.000Z

    Developing a composite material of polymers and micrometer-sized fillers with higher heat conductance is crucial to realize modular packaging of electronic components at higher densities. Enhancement mechanisms of the heat conductance of the polymer-filler interfaces by adding the surface-coupling agent in such a polymer composite material are investigated through the non-equilibrium molecular dynamics (MD) simulation. A simulation system is composed of ?-alumina as the filler, bisphenol-A epoxy molecules as the polymers, and model molecules for the surface-coupling agent. The inter-atomic potential between the ?-alumina and surface-coupling molecule, which is essential in the present MD simulation, is constructed to reproduce the calculated energies with the electronic density-functional theory. Through the non-equilibrium MD simulation runs, we find that the thermal resistance at the interface decreases significantly by increasing either number or lengths of the surface-coupling molecules and that the effective thermal conductivity of the system approaches to the theoretical value corresponding to zero thermal-resistance at the interface. Detailed analyses about the atomic configurations and local temperatures around the interface are performed to identify heat-transfer routes through the interface.

  18. Surface loss probability of atomic hydrogen for different electrode cover materials investigated in H{sub 2}-Ar low-pressure plasmas

    SciTech Connect (OSTI)

    Sode, M., E-mail: maik.sode@ipp.mpg.de; Schwarz-Selinger, T.; Jacob, W. [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, D-85748 Garching (Germany); Kersten, H. [Institute for Experimental and Applied Physics, Christian-Albrechts-Universität zu Kiel, Leibnizstraße 11-19, D-24098 Kiel (Germany)

    2014-07-07T23:59:59.000Z

    In an inductively coupled H{sub 2}-Ar plasma at a total pressure of 1.5?Pa, the influence of the electrode cover material on selected line intensities of H, H{sub 2}, and Ar are determined by optical emission spectroscopy and actinometry for the electrode cover materials stainless steel, copper, tungsten, Macor{sup ®}, and aluminum. Hydrogen dissociation degrees for the considered conditions are determined experimentally from the measured emission intensity ratios. The surface loss probability ?{sub H} of atomic hydrogen is correlated with the measured line intensities, and ?{sub H} values are determined for the considered materials. Without the knowledge of the atomic hydrogen temperature, ?{sub H} cannot be determined exactly. However, ratios of ?{sub H} values for different surface materials are in first order approximation independent of the atomic hydrogen temperature. Our results show that ?{sub H} of copper is equal to the value of stainless steel, ?{sub H} of Macor{sup ®} and tungsten is about 2 times smaller and ?{sub H} of aluminum about 5 times smaller compared with stainless steel. The latter ratio is in reasonable agreement with literature. The influence of the atomic hydrogen temperature T{sub H} on the absolute value is thoroughly discussed. For our assumption of T{sub H}?=?600?K, we determine a ?{sub H} for stainless steel of 0.39?±?0.13.

  19. Ch 20. Magnetism Liu UCD Phy1B 2012 1

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    Ch 20. Magnetism Liu UCD Phy1B 2012 1 #12;I. MagnetI. Magnet Poles of a magnet: magnetic effect is strongest When the magnet is freely suspended North pole: pointing to north South pole: pointing to south Poles always come in pairs Liu UCD Phy1B 2012 2 #12;Magnetic MaterialsMagnetic Materials Magnetite Fe3O4

  20. Active Magnetic Regenerator Experimental Optimization

    E-Print Network [OSTI]

    Victoria, University of

    the potential to create more efficient and compact refrigeration devices is an Active Magnetic Regenerative temperature refrigerators, as well as efficient gas liquefaction plants (AMRLs). Active Magnetic Regenerator Refrigeration exploits the magnetocaloric effect displayed by magnetic materials whereby a reversible

  1. Temperature-dependent tensile strength, surface roughness diagnostics, and magnetic support and positioning of polymer ICF shells. Final report, October 1, 1993--April 30, 1995

    SciTech Connect (OSTI)

    Honig, A.

    1995-12-15T23:59:59.000Z

    During the course of this grant, we perfected emissivity and accommodation coefficient measurements on polymer ICF shells in the temperature range 250 to 350 K. Values for polystyrene shells are generally between 10{sup -2} and 10{sup -3}, which are very advantageous for ICF at cryogenic temperatures. Preliminary results on Br doped target shells indicate an accommodation coefficient, presumably associated with surface roughness on an atomic scale, about an order of magnitude larger than for ordinary polystyrene target shells. We also constructed apparatus with optical access for low temperature tensile strength and emissivity measurements, and made preliminary tests on this system. Magnetic shells were obtained both from GDP coating and from doping styrene with 10 manometer size ferromagnetic particles. The magnetic properties were measured through electron spin resonance (ESR). These experiments confirm the applicability of the Curie law, and establish the validity of using ESR measurements to determine shell temperature in the low temperature regime from 4K to 250K, thus complementing our presently accessible range. The high electron spin densities (> 10{sup 20}/CM{sup 3}) suggest magnetic levitation should be feasible at cryogenic temperatures. This work has resulted in two conference presentations, a Technical Report, a paper to be published in Fusion Technology, and a Master`s Thesis.

  2. Critical Materials Strategy Summary

    Broader source: Energy.gov (indexed) [DOE]

    in magnets, batteries, photovoltaic films and phosphors; environmentally sound mining and materials processing; and recycling. The eight programs and policies address...

  3. Ames Lab 101: Magnetic Refrigeration

    ScienceCinema (OSTI)

    Pecharsky, Vitalij

    2013-03-01T23:59:59.000Z

    Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.

  4. Ames Lab 101: Magnetic Refrigeration

    SciTech Connect (OSTI)

    Pecharsky, Vitalij

    2011-01-01T23:59:59.000Z

    Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.

  5. Magnetic gripper device

    DOE Patents [OSTI]

    Meyer, Ross E. (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.

  6. Magnetic gripper device

    DOE Patents [OSTI]

    Meyer, R.E.

    1993-03-09T23:59:59.000Z

    A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.

  7. Journal of Materials Processing Technology 189 (2007) 192198 Modelling of surface finish and tool flank wear in turning

    E-Print Network [OSTI]

    Ozel, Tugrul

    2007-01-01T23:59:59.000Z

    flank wear in turning of AISI D2 steel with ceramic wiper inserts Tugrul ¨Ozela,, Yigit Karpata, Lu (60 HRC) using ceramic wiper (multi-radii) design inserts. Multiple linear regression models. Experimental results indicate that surface roughness Ra values as low as 0.18­0.20 m are attainable with wiper

  8. Characterization of heterogeneous near-surface materials by joint 2D inversion of dc resistivity and seismic data

    E-Print Network [OSTI]

    Meju, Max

    multidimensional non- invasive dc resistivity and seismic refraction investigations of the near-surface have and seismic data Luis A. Gallardo1 and Max A. Meju Department of Environmental Science, Lancaster University-gradients of electrical resistivity and seismic velocity as constraints so as to investigate more precisely

  9. Overlap Technique for End-Cap Seals on Cylindrical Magnetic Shields

    E-Print Network [OSTI]

    Malkowski, S; Boissevain, J; Daurer, C; Filippone, B W; Hona, B; Plaster, B; Woods, D; Yan, H

    2013-01-01T23:59:59.000Z

    We present results from studies of the effectiveness of an overlap technique for forming a magnetic seal across a gap at the boundary between a cylindrical magnetic shield and an end-cap. In this technique a thin foil of magnetic material overlaps the two surfaces, thereby spanning the gap across the cylinder and the end-cap, with the magnetic seal then formed by clamping the thin magnetic foil to the surfaces of the cylindrical shield and the end-cap on both sides of the gap. In studies with a prototype 31-cm diameter, 91-cm long, 0.16-cm thick cylindrical magnetic shield and flared end-cap, the magnetic shielding performance of our overlap technique is comparable to that obtained with the conventional method in which the end-cap is placed in direct lapped contact with the cylindrical shield via through bolts or screws.

  10. Laced permanent magnet quadrupole drift tube magnets

    SciTech Connect (OSTI)

    Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.

    1989-03-01T23:59:59.000Z

    Twenty-three laced permanent magnet quadrupole drift tube magnets have been constructed, tested, and installed in the SuperHILAC heavy ion linear accelerator at LBL, marking the first accelerator use of this new type of quadrupole. The magnets consist of conventional tape-wound quadrupole electromagnets, using iron pole-pieces, with permanent magnet material (samarium cobalt) inserted between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the individual quadrupole magnets in a drift tube linac is never reversed, we can take advantage of this asymmetrical saturation to provide about 20% greater focusing strength than is available with conventional quadrupoles, while replacing the vanadium permendur poletips with iron poletips. Comparisons between these magnets and conventional tape-wound quadrupoles will be presented. 3 refs., 5 figs.

  11. NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSVOLUME 12 N0. 1 2005

    E-Print Network [OSTI]

    Weston, Ken

    , and Geochemistry 14 MAGNET SCIENCE & TECHNOLOGY Engineering Materials, Instrumentation, and Magnet Technology Magnet Science & Technology 42 7 including Engineering Materials, Instrumentation, and Magnet TechnologyNATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSVOLUME 12 · N0. 1 · 2005 OPERATED BY: FLORIDA STATE

  12. Flipping the switch on magnetism in strontium titanate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Flipping the switch on magnetism in strontium titanate Flipping the switch on magnetism in strontium titanate Researchers have found a way to magnetize this material using light,...

  13. Status of Magnetic Nozzle and Plasma Detachment Experiment

    SciTech Connect (OSTI)

    Chavers, D. Gregory; Dobson, Chris; Jones, Jonathan; Lee, Michael; Martin, Adam; Gregory, Judith; Cecil, Jim [Propulsion Research Center, MSFC NASA, Huntsville, AL 35812 (United States); Bengtson, Roger D.; Breizman, Boris; Arefiev, Alexey [Department of Physics, University of Texas at Austin, TX 78712 (United States); Institute of Fusion Studies, University of Texas at Austin, TX 78712 (United States); Chang-Diaz, Franklin; Squire, Jared; Glover, Tim; McCaskill, Greg [Ad Astra Rocket Company, 2101 NASA Parkway, Houston, TX 77058 (United States); Cassibry, Jason; Li Zhongmin [University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2006-01-20T23:59:59.000Z

    High power plasma propulsion can move large payloads for orbit transfer, lunar missions, and beyond with large savings in fuel consumption owing to the high specific impulse. At high power, lifetime of the thruster becomes an issue. Electrodeless devices with magnetically guided plasma offer the advantage of long life since magnetic fields confine the plasma radially and keep it from impacting the material surfaces. For decades, concerns have been raised about the plasma remaining attached to the magnetic field and returning to the vehicle along the closed magnetic field lines. Recent analysis suggests that this may not be an issue if the magnetic field is properly shaped in the nozzle region and the plasma has sufficient energy density to stretch the magnetic field downstream. An experiment is being performed to test the theory regarding the MHD detachment scenario. The status of that experiment will be discussed in this paper.

  14. Vacuum properties of sintered SmCo/sub 5/ magnets

    SciTech Connect (OSTI)

    Warren, R.W.; DePaula, R.F.; Hansborough, L.D.

    1981-12-01T23:59:59.000Z

    There are many desirable applications of powerful, rare-earth permanent magnets made of sintered SmCo/sub 5/ material within vacuum systems. One application is the use of large numbers of SmCo/sub 5/ magnets to provide the undulating magnetic field in a free-electron-laser wiggler structure. Tests were conducted at Los Alamos to determine the suitability of SmCo/sub 5/ magnets in a vacuum environment of approx. 10/sup -6/ torr. The vacuum performances of the wiggler system, with and without the SmCo/sub 5/ magnets (having approx. 11% of the total surface area) installed, were essentially identical. These tests indicate that SmCo/sub 5/ magnets have good vacuum properties and are suitable for use in many vacuum systems.

  15. Photoelectron spectroscopic study of the surface reactivity of the high T[c] material YBa?Cu?O?

    E-Print Network [OSTI]

    Liu, Hong-Xia

    1988-01-01T23:59:59.000Z

    extensive in the area of the high T, Y-Ba-Cu-0 system. 1. 1. Properties of the high T, Y-Ba-Cu-0 system The high T, Y-Ba-Cu-0 system is the single phase compound YBagCu309 8 with 5=2 (Cava et al 1987). It is an orthorhombically distorted perovskite.... The elimination of Cus+ satellite indicated the conversion to Cur+ or Cuo on the surface. As mentioned before, the sample is an orthorhombically distorted perovskite. The crystal structure facilitates reactive decomposition at high temperature (Gallagher et al...

  16. Electric-Field Control of Magnetism Intrinsic magnetoelectric coupling describes the microscopic interaction between magnetic and

    E-Print Network [OSTI]

    Maroncelli, Mark

    Electric-Field Control of Magnetism Intrinsic magnetoelectric coupling describes the microscopic interaction between magnetic and electric polarization in a single-phase material. The control of the magnetic of the two interactions. Moderate biaxial compression precipitates local magnetic competition

  17. Wind tunnel simulation of wind effects and associated displacement hazards on flat surface construction materials such as plywood

    E-Print Network [OSTI]

    Madeley, Jack T.

    1996-01-01T23:59:59.000Z

    materials. With respect to the latter, much of the research pertaining to wind effects has been done by structural engineers regarding wind hfting forces on building roof sections and forces on the face of buildings [Sachs, 1978, Melaragno, 1982]. Very... the flow is in a smooth linear path or in stratified laminae or layers. Turbulence occurs when there is random erratic movement breaking the smoothness of the flow [Melaragno, 1982]. At a point back from the leading edge of a plate, the laminar boundary...

  18. Microstructure of TiB{sub 2}/carbon steel surface-alloyed materials fabricated by high-energy electron beam irradiation

    SciTech Connect (OSTI)

    Euh, K. Lee, S.; Shin, K.

    1999-12-01T23:59:59.000Z

    The processing and the microstructural analysis of TiB{sub 2}/carbon steel surface-alloyed materials using the irradiation of a high-energy electron beam were investigated in this study. The mixtures of TiB{sub 2} powders and flux were deposited on a plain carbon steel substrate, and then electron beam was irradiated on these mixtures using an electron beam accelerator. The microstructure of the irradiated surface layer was composed of a melted region, an interfacial region, a coarse-grained heat-affected zone (HAZ), and a fine-grained HAZ. A few residual micropores were found in the melted region of the specimen processed without flux because of irregular thermal transfer, but their number was decreased in the specimens processed with a considerable amount of flux. As a result of irradiation, the Ti content was homogeneously maintained throughout the melted region, whose hardness was greatly improved. This was associated with the microstructural modification including the segregation of Ti and B along solidification cell boundaries and the formation of fine Ti(C, N) particles. The proper flux mix ratio was 15 to 30% to obtain excellent surface alloying and a homogeneous microstructure.

  19. Centrifugal Breakout of Magnetically Confined Line-Driven Stellar Winds

    E-Print Network [OSTI]

    A. ud-Doula; R. H. D. Townsend; S. P. Owocki

    2006-02-15T23:59:59.000Z

    We present 2D MHD simulations of the radiatively driven outflow from a rotating hot star with a dipole magnetic field aligned with the star's rotation axis. We focus primarily on a model with moderately rapid rotation (half the critical value), and also a large magnetic confinement parameter, $\\eta_{\\ast} \\equiv B_{\\ast}^2 R_{\\ast}^{2} / \\dot{M} V_{\\infty} = 600$. The magnetic field channels and torques the wind outflow into an equatorial, rigidly rotating disk extending from near the Kepler corotation radius outwards. Even with fine-tuning at lower magnetic confinement, none of the MHD models produce a stable Keplerian disk. Instead, material below the Kepler radius falls back on to the stellar surface, while the strong centrifugal force on material beyond the corotation escape radius stretches the magnetic loops outwards, leading to episodic breakout of mass when the field reconnects. The associated dissipation of magnetic energy heats material to temperatures of nearly $10^{8}$K, high enough to emit hard (several keV) X-rays. Such \\emph{centrifugal mass ejection} represents a novel mechanism for driving magnetic reconnection, and seems a very promising basis for modeling X-ray flares recently observed in rotating magnetic Bp stars like $\\sigma$ Ori E.

  20. Laced permanent magnet quadrupole drift tube magnets

    SciTech Connect (OSTI)

    Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.

    1988-10-01T23:59:59.000Z

    A laced permanent magnet quadrupole drift tube magnet has been constructed for a proof-of-principle test. The magnet is a conventional tape-wound quadrupole electromagnet, using iron pole- pieces, with the addition of permanent magnet material (neodymium iron) between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the quadrupole magnets in a drift tube linac is not reversed we can take advantage of this asymmetrical saturation to provide greater focusing strength. The magnet configuration has been optimized and the vanadium permendur poles needed in a conventional quadrupole have been replaced with iron poles. The use of permanent magnet material has allowed us to increase the focusing strength of the magnet by about 20% over that of a conventional tape-wound quadrupole. Comparisons will be made between this magnet and the conventional tape-wound quadrupole. 3 refs., 5 figs.

  1. Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials

    SciTech Connect (OSTI)

    Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula; Einfeld, Wayne

    2010-12-16T23:59:59.000Z

    Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the probability of correct detection (PCD) (or equivalently the false negative rate FNR = 1 ? PCD). The PCD/FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5) sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not PCD/FNR (which left a major gap in available information). Quantifying the PCD/FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in PCD/FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The study will investigate the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination recovered from coupons by sponge-wipe samples, RE, and PCD/FNR. The experimental design involves 16 test runs, to be performed in two blocks of eight runs. Three surface materials (stainless steel, vinyl tile, and ceramic tile) were tested in the first block, while three other surface materials (plastic, painted wood paneling, and faux leather) will be tested in the second block. The eight surface concentrations of the surrogate were randomly assigned to test runs within each block. Some of the concentrations will be very low and may present challenges for deposition, sampling, and analysis. However, such tests are needed to investigate RE and PCD/FNR over the full range of concentrations of interest. In each run, there will be 10 test coupons of each of the three surface materials. A positive control sample will be generated prior to each test sample. The positive control results will be used to 1) calculate RE values for the wipe sampling and analysis method, and 2) fit RE- and PCD-concentration equations, for each of the six surface materials. Data analyses will support 1) estimating the PCD for each combination of contaminant concentration and surface material, 2) estimating the surface concentrations and their uncertainties of the contaminant for each combination of concentration and surface material, 3) estimating RE (%) and their uncertainties for each combination of contaminant concentration and surface material, 4) fitting PCD-concentration and RE-concentration equations for each of the six surface materials, 5) assessing goodness-of-fit of the equations, and 6) quantifying the uncertainty in PCD and RE predictions made with the fitted equations.

  2. Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials

    SciTech Connect (OSTI)

    Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula; Einfeld, Wayne

    2011-05-01T23:59:59.000Z

    Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the false negative rate (FNR). The FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5) sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not FNR (which left a major gap in available information). Quantifying the FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The testing was performed by SNL and is now completed. The study investigated the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination recovered from coupons by sponge-wipe samples, RE, and FNR. The experimental design involves 16 test runs, performed in two blocks of eight runs. Three surface materials (stainless steel, vinyl tile, and ceramic tile) were tested in the first block, while three other surface materials (plastic, painted wood paneling, and faux leather) were tested in the second block. The eight surface concentrations of the surrogate were randomly assigned to test runs within each block. Some of the concentrations were very low and presented challenges for deposition, sampling, and analysis. However, such tests are needed to investigate RE and FNR over the full range of concentrations of interest. In each run, there were 10 test coupons of each of the three surface materials. A positive control sample was generated at the same time as each test sample. The positive control results will be used to 1) calculate RE values for the wipe sampling and analysis method, and 2) fit RE- and FNR-concentration equations, for each of the six surface materials. Data analyses will support 1) estimating the FNR for each combination of contaminant concentration and surface material, 2) estimating the surface concentrations and their uncertainties of the contaminant for each combination of concentration and surface material, 3) estimating RE (%) and their uncertainties for each combination of contaminant concentration and surface material, 4) fitting FNR-concentration and RE-concentration equations for each of the six surface materials, 5) assessing goodness-of-fit of the equations, and 6) quantifying the uncertainty in FNR and RE predictions made with the fitted equations.

  3. Magnetism in metal-organic capsules

    E-Print Network [OSTI]

    Atwood, Jerry L.

    2010-01-01T23:59:59.000Z

    Quantum Spin Chains in Magnetism: Molecules to Materials, J.Magnetism in metal-organic capsules Jerry L. Atwood,* a Euan

  4. Magnetic refrigeration apparatus with heat pipes

    DOE Patents [OSTI]

    Barclay, J.A.; Prenger, F.C. Jr.

    1985-10-25T23:59:59.000Z

    A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe or pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

  5. Magnetic refrigeration apparatus with heat pipes

    DOE Patents [OSTI]

    Barclay, John A. (Los Alamos, NM); Prenger, Jr., F. Coyne (Madison, WI)

    1987-01-01T23:59:59.000Z

    A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe of pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

  6. Experimental Design for a Macrofoam-Swab Study Relating the Recovery Efficiency and False Negative Rate to Low Concentrations of Two Bacillus anthracis Surrogates on Four Surface Materials

    SciTech Connect (OSTI)

    Piepel, Gregory F.; Hutchison, Janine R.

    2014-12-05T23:59:59.000Z

    This report describes the experimental design for a laboratory study to quantify the recovery efficiencies and false negative rates of a validated, macrofoam-swab sampling method for low concentrations of Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus (BG) spores on four surface materials (stainless steel, glass, vinyl tile, plastic light cover panel). Two analytical methods (culture and polymerase chain reaction) will be used. Only one previous study has investigated how the false negative rate depends on test factors. The surrogates BAS and BG have not been tested together in the same study previously. Hence, this study will provide for completing gaps in the available information on the performance of macrofoam-swab sampling at low concentrations.

  7. Experimental Design for a Macrofoam Swab Study Relating the Recovery Efficiency and False Negative Rate to Low Concentrations of Two Bacillus anthracis Surrogates on Four Surface Materials

    SciTech Connect (OSTI)

    Piepel, Gregory F.; Hutchison, Janine R.

    2014-04-16T23:59:59.000Z

    This report describes the experimental design for a laboratory study to quantify the recovery efficiencies and false negative rates of a validated, macrofoam swab sampling method for low concentrations of Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus (BG) spores on four surface materials (stainless steel, glass, vinyl tile, plastic light cover panel). Two analytical methods (plating/counting and polymerase chain reaction) will be used. Only one previous study has investigated false negative as a function of affecting test factors. The surrogates BAS and BG have not been tested together in the same study previously. Hence, this study will provide for completing gaps in the available information on the performance of macrofoam swab sampling at low concentrations.

  8. Review and comparison of magnet designs for magnetic refrigeration

    E-Print Network [OSTI]

    Bjørk, R; Smith, A; Pryds, N

    2014-01-01T23:59:59.000Z

    One of the key issues in magnetic refrigeration is generating the magnetic field that the magnetocaloric material must be subjected to. The magnet constitutes a major part of the expense of a complete magnetic refrigeration system and a large effort should therefore be invested in improving the magnet design. A detailed analysis of the efficiency of different published permanent magnet designs used in magnetic refrigeration applications is presented in this paper. Each design is analyzed based on the generated magnetic flux density, the volume of the region where this flux is generated and the amount of magnet material used. This is done by characterizing each design by a figure of merit magnet design efficiency parameter, $\\Lambda_\\mathrm{cool}$. The designs are then compared and the best design found. Finally recommendations for designing the ideal magnet design are presented based on the analysis of the reviewed designs.

  9. Atomic multipole relaxation rates near surfaces

    E-Print Network [OSTI]

    J. A. Crosse; Stefan Scheel

    2010-08-13T23:59:59.000Z

    The spontaneous relaxation rates for an atom in free space and close to an absorbing surface are calculated to various orders of the electromagnetic multipole expansion. The spontaneous decay rates for dipole, quadrupole and octupole transitions are calculated in terms of their respective primitive electric multipole moments and the magnetic relaxation rate is calculated for the dipole and quadrupole transitions in terms of their respective primitive magnetic multipole moments. The theory of electromagnetic field quantization in magnetoelectric materials is used to derive general expressions for the decay rates in terms of the dyadic Green function. We focus on the decay rates in free space and near an infinite half space. For the decay of atoms near to an absorbing dielectric surface we find a hierarchy of scaling laws depending on the atom-surface distance z.

  10. Nanocomposite Magnets: Transformational Nanostructured Permanent Magnets

    SciTech Connect (OSTI)

    None

    2010-10-01T23:59:59.000Z

    Broad Funding Opportunity Announcement Project: GE is using nanomaterials technology to develop advanced magnets that contain fewer rare earth materials than their predecessors. Nanomaterials technology involves manipulating matter at the atomic or molecular scale, which can represent a stumbling block for magnets because it is difficult to create a finely grained magnet at that scale. GE is developing bulk magnets with finely tuned structures using iron-based mixtures that contain 80% less rare earth materials than traditional magnets, which will reduce their overall cost. These magnets will enable further commercialization of HEVs, EVs, and wind turbine generators while enhancing U.S. competitiveness in industries that heavily utilize these alternatives to rare earth minerals.

  11. Materials research at selected Japanese laboratories. Based on a 1992 visit: Overview, summary of highlights, notes on laboratories and topics

    SciTech Connect (OSTI)

    Not Available

    1994-02-01T23:59:59.000Z

    I visited Japan from June 29 to August 1, 1992. The purpose of this visit was to assess the status of materials science research at selected governmental, university and industrial laboratories and to established acquaintances with Japanese researchers. The areas of research covered by these visits included ceramics, oxide superconductors, intermetallics alloys, superhard materials and diamond films, high-temperature materials and properties, mechanical properties, fracture, creep, fatigue, defects, materials for nuclear reactor applications and irradiation effects, high pressure synthesis, self-propagating high temperature synthesis, microanalysis, magnetic properties and magnetic facilities, and surface science.

  12. NEBRASKA CENTER FOR MATERIALS AND NANOSCIENCE

    E-Print Network [OSTI]

    Farritor, Shane

    Director, Materials and Surface Engineering Program, National Science Foundation Materials Research at NSF. Cooper is Director of the Materials and Surface Engineering program at the National Science Foundation: An Overview of the Materials and Surface Engineering Program The materials and surface engineering program

  13. Thermal structure and cooling of superfluid neutron stars with accreted magnetized envelopes

    E-Print Network [OSTI]

    A. Y. Potekhin; D. G. Yakovlev; G. Chabrier; O. Y. Gnedin

    2003-09-17T23:59:59.000Z

    We study the thermal structure of neutron stars with magnetized envelopes composed of accreted material, using updated thermal conductivities of plasmas in quantizing magnetic fields, as well as equation of state and radiative opacities for partially ionized hydrogen in strong magnetic fields. The relation between the internal and local surface temperatures is calculated and fitted by an analytic function of the internal temperature, magnetic field strength, angle between the field lines and the normal to the surface, surface gravity, and the mass of the accreted material. The luminosity of a neutron star with a dipole magnetic field is calculated for various values of the accreted mass, internal temperature, and magnetic field strength. Using these results, we simulate cooling of superfluid neutron stars with magnetized accreted envelopes. We consider slow and fast cooling regimes, paying special attention to very slow cooling of low-mass superfluid neutron stars. In the latter case, the cooling is strongly affected by the combined effect of magnetized accreted envelopes and neutron superfluidity in the stellar crust. Our results are important for interpretation of observations of isolated neutron stars hottest for their age, such as RX J0822-43 and PSR B1055-52.

  14. Laser detection of material thickness

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM)

    2002-01-01T23:59:59.000Z

    There is provided a method for measuring material thickness comprising: (a) contacting a surface of a material to be measured with a high intensity short duration laser pulse at a light wavelength which heats the area of contact with the material, thereby creating an acoustical pulse within the material: (b) timing the intervals between deflections in the contacted surface caused by the reverberation of acoustical pulses between the contacted surface and the opposite surface of the material: and (c) determining the thickness of the material by calculating the proportion of the thickness of the material to the measured time intervals between deflections of the contacted surface.

  15. Magnetic domain walls driven by interfacial phenomena

    E-Print Network [OSTI]

    Emori, Satoru

    2014-01-01T23:59:59.000Z

    A domain wall in a ferromagnetic material is a boundary between differently magnetized regions, and its motion provides a convenient scheme to control the magnetization state of the material. Domain walls can be confined ...

  16. Vibrational Damping of Composite Materials

    E-Print Network [OSTI]

    Biggerstaff, Janet M.

    2006-01-01T23:59:59.000Z

    the damping material and epoxy resin. The surface of theinfiltration of the epoxy resin into the damping materialthe damping material and resin (epoxy) is occurring and is

  17. Conference Proceedings (Refereed Invited Reviews). 1. "Role of Large-Scale Magnetic Fields and Material Flows in the Formation of Solar Filaments

    E-Print Network [OSTI]

    Mackay, Duncan

    Conference Proceedings (Refereed Invited Reviews). 1. "Role of Large-Scale Magnetic Fields Scale Structures and their Role in Solar Activity, ASP Conference Proceedings Series, 346, 177. 2. "The-297. Conference Proceedings (Others). 1. "Basic Magnetic Field Configurations for Filament Channels and Filaments

  18. Spectroscopic Characterization of Actinide Materials

    SciTech Connect (OSTI)

    Buck, Edgar C.; Clark, Dave L.; Caciuffo, Roberto; van der Laan, Gerrit

    2010-11-11T23:59:59.000Z

    Advanced spectroscopic techniques provide new and unique tools for unraveling the nature of the electronic structure of actinide materials. Inelastic neutron scattering experiments that address temporal aspects of lattice and magnetic fluctuations, probe electromagnetic multipole interactions and the coupling between electronic and vibrational degrees of freedom. Nuclear magnetic resonance clearly demonstrates different magnetic ground states at low temperature. Photoemission spectroscopies provide information on the occupied part of the electron density of states and have been used to investigate the momentum-resolved electronic structure and the topology of the Fermi surface in a variety of actinide compounds. Furthermore, x-ray absorption and electron energy-loss spectroscopies have been used to probe the relativistic nature, the occupation number, and the degree of localization of 5f electrons across the actinide series. More recently, element and edge-specific resonant and non-resonant inelastic x-ray scattering experiments have provided the opportunity of measuring elementary electronic excitations with higher resolution than traditional absorption techniques. Here, we will discuss the results obtained by most of these different spectroscopic techniques in studying the electronic and magnetic properties of selected actinide compounds, chosen as typical examples of systems with 5f electrons having an itinerant or a localized character, or lying near the localization-delocalization boundary.

  19. Measurement of Thermal Diffusivity and Conductivity in Advanced Nanostructured Materials

    E-Print Network [OSTI]

    Teweldebrhan, Desalegne Bekuretsion

    2012-01-01T23:59:59.000Z

    in Magnetic Materials . . . . . . . . . . . . . . . viimportants of understanding materials properties typicallyY.S. Ju, Annual Review of Materials Science, 29, 261 (1999).

  20. New Materials for Spintronics. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Abstract: One of the critical materials needs for the development of spin electronics is diluted magnetic semiconductors (DMS) which retain their ferromagnetism at and...

  1. Hardfacing material

    DOE Patents [OSTI]

    Branagan, Daniel J. (Iona, ID)

    2012-01-17T23:59:59.000Z

    A method of producing a hard metallic material by forming a mixture containing at least 55% iron and at least one of boron, carbon, silicon and phosphorus. The mixture is formed into an alloy and cooled to form a metallic material having a hardness of greater than about 9.2 GPa. The invention includes a method of forming a wire by combining a metal strip and a powder. The metal strip and the powder are rolled to form a wire containing at least 55% iron and from two to seven additional elements including at least one of C, Si and B. The invention also includes a method of forming a hardened surface on a substrate by processing a solid mass to form a powder, applying the powder to a surface to form a layer containing metallic glass, and converting the glass to a crystalline material having a nanocrystalline grain size.

  2. MRS (monitored retrievable storage) systems study Task G report: The role and functions of surface storage of radioactive material in the federal waste management system

    SciTech Connect (OSTI)

    Wood, T.W.; Short, S.M.; Woodruff, M.G.; Altenhofen, M.K.; MacKay, C.A.

    1989-04-01T23:59:59.000Z

    This is one of nine studies undertaken by contractors to the US Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), to provide a technical basis for re-evaluating the role of a monitored retrievable storage (MRS) facility. The study investigates the functions that could be performed by surface storage of radioactive material within the federal radioactive waste management system, including enabling acceptance of spent fuel from utility owners, scheduling of waste-preparation processes within the system, enhancement of system operating reliability, and conditioning the thermal (decay heat) characteristics of spent fuel emplaced in a repository. The analysis focuses particularly on the effects of storage capacity and DOE acceptance schedule on power reactors. Figures of merit developed include the storage capacity (in metric tons of uranium (MTU)) required to be added beyond currently estimated maximum spent fuel storage capacities and its associated cost, and the number of years that spent fuel pools would remain open after last discharge (in pool-years) and the cost of this period of operation. 27 refs., 36 figs., 18 tabs.

  3. The interactive effects of pH, surface tension, and solution density for flotation systems for separation of equivalent-density materials: separation of ABS from HIPS

    SciTech Connect (OSTI)

    Karvelas, D.E.; Jody, B.J.; Pomykala, J.A.; Daniels, E.J.

    1996-07-01T23:59:59.000Z

    This paper presents the results of research being conducted at Argonne National Laboratory, to develop a cost-effective and environmentally acceptable process for the separation of high-value plastics from discarded household appliances. The process under development has separated high-purity (greater than 99.5%) acrylonitrile-butadiene-styrene (ABS) and high-impact polystyrene (HIPS) from commingled plastics generated by appliance-shredding and metal recovery operations. Plastics of similar densities, such as ABS and HIPS are further separated by using a chemical solution. By controlling the surface tension, the density and the temperature of the chemical solution, we are able to selectively float/separate plastics that have equivalent densities. In laboratory-scale tests, this technique has proven highly effective in recovering high-purity plastics materials from discarded household appliances and other obsolete durable goods. A pilot plant is under construction to demonstrate and assess the technical and economic performance of this process. In this paper, we examine the technical and economic issues that affect the recovery and separation of plastics and provide an update on Argonne`s plastics separation research and development activities.

  4. Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization

    DOE Patents [OSTI]

    Doughty, Frank C. (Plano, TX); Spencer, John E. (Plano, TX)

    2000-12-19T23:59:59.000Z

    In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within the resonance zone.

  5. Computational Chemical Materials Engineering

    E-Print Network [OSTI]

    Home Computational Chemical and Materials Engineering Tahir Cagin Chemical Engineering Department through processing for improving their performance for engineering applications · Use and develop with usable ­ Chemical ­ Electronic ­ Optical ­ Magnetic ­ Transport, thermal and mechanical properties

  6. Magnetic Refrigeration | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    temperature," said Frank Johnson, a materials scientist and project leader on GE's magnetic refrigeration project. Developed over the past decade, these new magnetocaloric...

  7. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your Home asLCLSLaboratoryRowland toShade Landscaping forandLarge

  8. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your Home asLCLSLaboratoryRowland toShade Landscaping

  9. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLand andComputing

  10. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLand andComputingLarge

  11. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLand andComputingLargeLarge

  12. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLand

  13. The DOE Center of Excellence for the Synthesis and Processing of Advanced Materials: Research briefs

    SciTech Connect (OSTI)

    NONE

    1996-01-01T23:59:59.000Z

    This publication is designed to inform present and potential customers and partners of the DOE Center of Excellence for the Synthesis and Processing of Advanced Materials about significant advances resulting from Center-coordinated research. The format is an easy-to-read, not highly technical, concise presentation of the accomplishments. Selected accomplishments from each of the Center`s seven initial focused projects are presented. The seven projects are: (1) conventional and superplastic forming; (2) materials joining; (3) nanoscale materials for energy applications; (4) microstructural engineering with polymers; (5) tailored microstructures in hard magnets; (6) processing for surface hardness; and (7) mechanically reliable surface oxides for high-temperature corrosion resistance.

  14. Magnetic Exchange Coupling and Single-Molecule Magnetism in Uranium Complexes

    E-Print Network [OSTI]

    Rinehart, Jeffrey Dennis

    2010-01-01T23:59:59.000Z

    J. -P. ; Kahn, M. L. In Magnetism: Molecules to Materials V.R. Simple Models of Magnetism; Oxford University Press:for interpreting uranium magnetism and will be discussed in

  15. Method for improving performance of high temperature superconductors within a magnetic field

    DOE Patents [OSTI]

    Wang, Haiyan (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM); Maiorov, Boris A. (Los Alamos, NM); Civale, Leonardo (Los Alamos, NM)

    2010-01-05T23:59:59.000Z

    The present invention provides articles including a base substrate including a layer of an oriented cubic oxide material having a rock-salt-like structure layer thereon; and, a buffer layer upon the oriented cubic oxide material having a rock-salt-like structure layer, the buffer layer having an outwardly facing surface with a surface morphology including particulate outgrowths of from 10 nm to 500 run in size at the surface, such particulate outgrowths serving as flux pinning centers whereby the article maintains higher performance within magnetic fields than similar articles without the necessary density of such outgrowths.

  16. Ultrafast Magnetism Dynamics Measure Using Tabletop Ultrafast EUV Sources

    SciTech Connect (OSTI)

    Silva, Thomas J. [NIST] [NIST; Murnane, Margaret [University of Colorado] [University of Colorado

    2013-08-21T23:59:59.000Z

    In our work to date, we made two significant advances. First we demonstrated element-selective demagnetization dynamics for the first time, with a record time resolution for x-ray probing of 55 fs. Second, in new work, we were able to probe the timescale of the exchange interaction in magnetic materials, also for the first time. Our measurements were made using the transverse magneto-optic Kerr effect (T-MOKE) geometry, since the reflectivity of a magnetic material changes with the direction of the magnetization vector of a surface. In our experiment, we periodically reversed the magnetization direction of a grating structure made of Permalloy (Ni80Fe20) using an external magnetic field. To achieve maximum contrast, we used HHG light spanning the M-shell (3p) absorption edges of Fe and Ni. Our characterization of the static magnetization of a Permalloy sample shows high magnetic asymmetry at photon energies just above and below the absorption edges at 55 eV and 65 eV, respectively. This result is in excellent agreement with measurements done on the same using a synchrotron source.

  17. www.advmat.de www.MaterialsViews.com

    E-Print Network [OSTI]

    McCalley, James D.

    . In this context, functional magnetic materials, such as advanced hard and soft magnets, magnetic refrigerants, Christina H. Chen, S. G. Sankar, and J. Ping Liu Magnetic Materials and Devices for the 21st Century Sciences Delft University of Technology 2629 JB Delft, The Netherlands Dr. C. H. Chen Magnetics Laboratory

  18. The surface-state of the topological insulator Bi2Se3 revealed by cyclotron resonance

    SciTech Connect (OSTI)

    Mcdonald, Ross D [Los Alamos National Laboratory; Ayala - Valenzuela, Oscar E [Los Alamos National Laboratory; Altarawneh, Moaz M [Los Alamos National Laboratory; Analytis, James G [STANFORD UNIV/SLAC; Chu, J. H. [STANFORD UNIV/SLAC; Fisher, R. [STANFORD UNIV/SLAC

    2011-01-14T23:59:59.000Z

    Transport measurements of topological insulators are dominated by the conductivity of the bulk, leading to substantial difficulties in resolving the properties of the surface. To this end, we use high magnetic field, rf- and microwave-spectroscopy to selectively couple to the surface conductivity of Bi2Se3 at high frequency. In the frequency range of a few GHz we observe a crossover from quantum oscillations indicative of a small 3D Fermi surface, to cyclotron resonance indicative of a 2D surface state. By probing the conductivity at reduced skin depths, we have observed a 2D cyclotron resonance from a material whose bulk Fermi-surface is 3D. The frequency-magnetic field scaling of this resonance is inconsistent with the bulk effective mass, but more consistent with the dispersion and band filling of a Dirac-like surface state as observed by ARPES, with substantial manybody renormalization.

  19. Vehicle Technologies Office: 2009 Propulsion Materials R&D Annual...

    Broader source: Energy.gov (indexed) [DOE]

    09propulsionmaterials.pdf More Documents & Publications Magnetic Material for PM Motors Permanent Magnet Development for Automotive Traction Motors Vehicle Technologies Office:...

  20. Photoemission Spectroscopy of Magnetic and Nonmagnetic Impurities on the Surface of the Bi[subscript 2]Se[subscript 3] Topological Insulator

    E-Print Network [OSTI]

    Valla, T.

    Dirac-like surface states on surfaces of topological insulators have a chiral spin structure that suppresses backscattering and protects the coherence of these states in the presence of nonmagnetic scatterers. In contrast, ...

  1. Magnetic-field sensing coil embedded in ceramic for measuring ambient magnetic field

    DOE Patents [OSTI]

    Takahashi, Hironori

    2004-02-10T23:59:59.000Z

    A magnetic pick-up coil for measuring magnetic field with high specific sensitivity, optionally with an electrostatic shield (24), having coupling elements (22) with high winding packing ratio, oriented in multiple directions, and embedded in ceramic material for structural support and electrical insulation. Elements of the coil are constructed from green ceramic sheets (200) and metallic ink deposited on surfaces and in via holes of the ceramic sheets. The ceramic sheets and the metallic ink are co-fired to create a monolithic hard ceramic body (20) with metallized traces embedded in, and placed on exterior surfaces of, the hard ceramic body. The compact and rugged coil can be used in a variety of environments, including hostile conditions involving ultra-high vacuum, high temperatures, nuclear and optical radiation, chemical reactions, and physically demanding surroundings, occurring either individually or in combinations.

  2. Inversion of surface and borehole gravity with thresholding and density constraints Jiajia Sun and Yaoguo Li, Center for Gravity, Electrical and Magnetic Studies, Department of Geophysics, Colorado

    E-Print Network [OSTI]

    and Yaoguo Li, Center for Gravity, Electrical and Magnetic Studies, Department of Geophysics, Colorado School of geophysical data has been widely uti- lized in data interpretation in both hydrocarbon and mineral exploration

  3. Low-temperature magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1983-05-26T23:59:59.000Z

    The invention relates to magnetic refrigeration and more particularly to low temperature refrigeration between about 4 and about 20 K, with an apparatus and method utilizing a belt of magnetic material passed in and out of a magnetic field with heat exchangers within and outside the field operably disposed to accomplish refrigeration.

  4. Low-temperature magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, John A. (Los Alamos, NM)

    1985-01-01T23:59:59.000Z

    The disclosure is directed to a low temperature 4 to 20 K. refrigeration apparatus and method utilizing a ring of magnetic material moving through a magnetic field. Heat exchange is accomplished in and out of the magnetic field to appropriately utilize the device to execute Carnot and Stirling cycles.

  5. Self-assembly of graphene oxide coated soft magnetic carbonyl iron particles and their magnetorheology

    SciTech Connect (OSTI)

    Zhang, W. L.; Choi, H. J., E-mail: hjchoi@inha.ac.kr [Department of Polymer Science and Engineering, Inha University, Incheon 402-751 (Korea, Republic of)

    2014-05-07T23:59:59.000Z

    The surface of carbonyl iron (CI) microspheres was modified with graphene oxide (GO) as a coating material using 4-aminobenzoic acid as the grafting agent. The morphology, elemental composition, and magnetic properties of the GO-coated CI (GO/CI) particles were examined by scanning electron microscopy, energy dispersive X-ray spectroscopy and vibrating sample magnetometry, respectively, confirming their composite formation. The magnetorheological (MR) performance of the GO/CI particle-based suspension was examined using a rotational rheometer connected to a magnetic field supply. The GO/CI particles suspension exhibited typical MR properties with increasing shear stress and viscosity depending on the applied magnetic field strength.

  6. Oldest Known Magnet's Secrets Revealed Under High Pressures ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    dichroism technique is readily applied to most magnetic materials without the need for isotope enrichment, and provides a true measure of long-range magnetic order." Other...

  7. Magnetic Nanocomposite Materials for High Temperature Applications Frank Johnson, Amy Hsaio, Colin Ashe, David Laughlin, David Lambeth, Michael E. McHenry

    E-Print Network [OSTI]

    McHenry, Michael E.

    have been investigated for various soft magnetic applications including transformers and inductive requirements and with needs for large inductions at high temperatures. Recent work in characterizing for high temperature power electronics will be reviewed. 1. Introduction 1.1 Key Principles of Soft

  8. Porous Materials Porous Materials

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Porous Materials x Porous Materials · Physical properties * Characteristic impedance p = p 0 e -jk xa- = vej[ ] p x - j ; Zc= p ve = c ka 0k = c 1-j #12;2 Porous Materials · Specific acoustic impedance Porous Materials · Finite thickness ­ blocked p e + -jk (x-d)a p e - jk (x-d)a d x #12

  9. Transient magnetic field and temperature modeling in large magnet applications

    SciTech Connect (OSTI)

    Gurol, H.; Hardy, G.E.; Peck, S.D.; Leung, E. (General Dynamics Corp., San Diego, CA (USA). Space Systems Div.)

    1989-07-01T23:59:59.000Z

    This paper discusses a coupled magnetic/thermal model developed to study heat and magnetic field diffusion in conducting materials subject to time-varying external fields. There are numerous applications, both military and commercial. These include: energy storage devices, pulsed power transformers, and electromagnetic launchers. The time scales of interest may range from a magnetic field pulse of a microsecond in an electromagnetic launcher, to hundreds of seconds in an energy storage magnet. The problem can be dominated by either the magnetic field or heat diffusion, depending on the temperature and the material properties of the conductor. In general, heat diffuses much more rapidly in high electrical conductivity materials of cryogenic temperatures. The magnetic field takes longer to diffuse, since screening currents can be rapidly set up which shield the interior of the material from further magnetic field penetration. Conversely, in high resistivity materials, the magnetic field diffuses much more rapidly. A coupled two-dimensional thermal/magnetic model has been developed. The results of this model, showing the time and spatial variation of the magnetic field and temperature, are discussed for the projectile of an electromagnetic launcher.

  10. Microwave magnetic dynamics in highly conducting magnetic nanostructures

    SciTech Connect (OSTI)

    Kostylev, M.; Ivanov, E.; Samarin, S. [School of Physics M013, The University of Western Australia, Crawley, WA 6009 (Australia); Ding, J.; Adeyeye, A. O. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

    2014-05-07T23:59:59.000Z

    We performed low-noise broadband microstrip ferromagnetic resonance (FMR) measurements of the resonant modes of an array of metallic ferromagnetic nanostripes. In addition to a strong signal of the fundamental mode, we observed up to five weak-amplitude peaks in the field-resolved FMR traces, depending on the frequency. These higher-order absorption peaks have been theoretically identified as due to resonant excitation of odd and even standing spin waves across the direction of confinement in array plane (i.e., across the stripe width). The theory we developed suggests that the odd modes become excited in the spatially uniform microwave field of the FMR setup due to the large conductivity of metals. This promotes excitation of large-amplitude eddy currents in the sample by the incident microwave magnetic field and ultimately results in excitation of these modes. Following this theory, we found that the eddy current contribution is present only for patterned materials and when the microwave magnetic field is incident on one surface of sample surface, as it is in the case of a microstrip FMR.

  11. Journal of Intelligent Material Systems and Structures

    E-Print Network [OSTI]

    Pan, Ernie

    by a magnetic field or vice versa. These materials are promising for wide engineering applica- tions, like composite can be induced by an applied magnetic potential. It means that a finite magnetoelectric of magnetoelectric coefficients. Pure magnetic and combined magnetic­mechanical loads are analyzed. The meshless

  12. Magnetic refrigeration for spacecraft systems

    SciTech Connect (OSTI)

    Barclay, J.A.

    1981-01-01T23:59:59.000Z

    Magnetic refrigerators, i.e., those that use the magnetocaloric effect of a magnetic working material in a thermodynamic cycle, offer potentially reliable, and efficient refrigeration over a variety of temperature ranges and cooling powers. A descriptive analysis of magnetic refrigeration systems is performed with particular emphasis on more efficient infrared detector cooling. Three types of magnetic refrigerator designs are introduced to illustrate some of the possibilities.

  13. Chemistry and Materials Science progress report, first half FY 1992. Weapons-Supporting Research and Laboratory Directed Research and Development

    SciTech Connect (OSTI)

    Not Available

    1992-07-01T23:59:59.000Z

    This report contains sections on: Fundamentals of the physics and processing of metals; interfaces, adhesion, and bonding; energetic materials; plutonium research; synchrotron radiation-based materials science; atomistic approach to the interaction of surfaces with the environment: actinide studies; properties of carbon fibers; buried layer formation using ion implantation; active coherent control of chemical reaction dynamics; inorganic and organic aerogels; synthesis and characterization of melamine-formaldehyde aerogels; structural transformation and precursor phenomena in advanced materials; magnetic ultrathin films, surfaces, and overlayers; ductile-phase toughening of refractory-metal intermetallics; particle-solid interactions; electronic structure evolution of metal clusters; and nanoscale lithography induced chemically or physically by modified scanned probe microscopy.

  14. Thickness dependence of magnetic anisotropy in thin Ni films electrodeposited onto the (011) and (001) surfaces of n-GaAs

    SciTech Connect (OSTI)

    Gubbiotti, G.; Carlotti, G.; Tacchi, S.; Liu, Y.-K.; Scheck, C.; Schad, R.; Zangari, G. [INFM CRS-SOFT, c/o Universita di Roma 'La Sapienza', I-00185, Rome (Italy); INFM UdR-Perugia, c/o Dipartimento di Fisica, Universita di Perugia, Via A. Pascoli, 06123 Perugia (Italy); INFM-National Center for nanoStructures and bioSystem at Surfaces (S3) Modena, and Dipartimento di Fisica, Universita di Perugia, Via A. Pascoli, 06123 Perugia (Italy); IINFM UdR-Perugia, Dipartimento di Fisica, Universita di Perugia, Via A. Pascoli, 06123 Perugia (Italy); MINT Center, University of Alabama, Tuscaloosa Alabama 35401 (United States); Department of Materials Science and Engineering and Center for Electrochemical Science and Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States)

    2005-05-15T23:59:59.000Z

    Brillouin light scattering from thermal spin waves has been exploited to investigate the thickness dependence of magnetic anisotropy of Ni films, with thickness in the range 7-35 nm, grown by electrodeposition onto either (011)- or (001)-GaAs substrates. In the former case, Ni films exhibit a well-defined in-plane uniaxial anisotropy induced by the symmetry of the substrate. In the case of the (001)-GaAs substrate, instead, the magnetic anisotropy results from a combination of both a fourfold and a twofold contribution. The physical mechanisms responsible for the observed anisotropy, as well as its dependence on film thickness, are discussed in detail.

  15. Magnetism in nanoparticle LaCoO3

    E-Print Network [OSTI]

    Durand, A. M.

    2013-01-01T23:59:59.000Z

    Magnetism in nanoparticle LaCoO 3 A. M. Durand, 1 D. P.o ? 37 K. For T magnetism in bulk LCO is associatedto surfaces or interfaces. The magnetism of LaCoO 3 (LCO) is

  16. IEEE Transactions on Energy Conversion, Vol. 14, No. 4, December 1999 1043 OptimalCurrent Control Strategies for Surface-MountedPermanent-Magnet

    E-Print Network [OSTI]

    Chapman, Patrick

    . There has been considerable work in the area of choosing optimal current excitation of PMSM drives minimizing the rms stator Permanent-magnet synchronous machine (PMSM) drives current was set forth in [6 that In designing PMSM drives, two factors Of interest are would he difficult to implement in a real-time control

  17. Tuning the Optical Properties of Nanoscale Materials on Surfaces Through Controlled Exchange Reactions on Cadmium Selenide Quantum Dots and Patterning of Gold and QD Nanoparticle Arrays 

    E-Print Network [OSTI]

    Pravitasari, Arika

    2013-11-11T23:59:59.000Z

    nanostructure arrays serve as great platforms not only for future applications in plasmonic based sensing and optical devices but also for the fundamental studies of their localized surface plasmon resonance (LSPR). An alternative method of patterning, a...

  18. Microwave impregnation of porous materials with thermal energy storage materials

    DOE Patents [OSTI]

    Benson, David K. (Golden, CO); Burrows, Richard W. (Conifer, CO)

    1993-01-01T23:59:59.000Z

    A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

  19. Microwave impregnation of porous materials with thermal energy storage materials

    DOE Patents [OSTI]

    Benson, D.K.; Burrows, R.W.

    1993-04-13T23:59:59.000Z

    A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

  20. Materials for light-induced water splitting: In situ controlled surface preparation of GaPN epilayers grown lattice-matched on Si(100)

    SciTech Connect (OSTI)

    Supplie, Oliver, E-mail: oliver.supplie@tu-ilmenau.de [Technische Universität Ilmenau, Institut für Physik, Gustav-Kirchhoff-Str. 5, 98684 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institute for Solar Fuels, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Humboldt-Universität zu Berlin, Institut für Physik, Newtonstr. 15, 12489 Berlin (Germany); May, Matthias M.; Stange, Helena [Helmholtz-Zentrum Berlin, Institute for Solar Fuels, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Humboldt-Universität zu Berlin, Institut für Physik, Newtonstr. 15, 12489 Berlin (Germany); Höhn, Christian [Helmholtz-Zentrum Berlin, Institute for Solar Fuels, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Lewerenz, Hans-Joachim [Helmholtz-Zentrum Berlin, Institute for Solar Fuels, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); California Institute of Technology, Joint Center for Artificial Photosynthesis, 1200 East California Boulevard, Pasadena, California 91125 (United States); Hannappel, Thomas [Technische Universität Ilmenau, Institut für Physik, Gustav-Kirchhoff-Str. 5, 98684 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institute for Solar Fuels, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)

    2014-03-21T23:59:59.000Z

    Energy storage is a key challenge in solar-driven renewable energy conversion. We promote a photochemical diode based on dilute nitride GaPN grown lattice-matched on Si(100), which could reach both high photovoltaic efficiencies and evolve hydrogen directly without external bias. Homoepitaxial GaP(100) surface preparation was shown to have a significant impact on the semiconductor-water interface formation. Here, we grow a thin, pseudomorphic GaP nucleation buffer on almost single-domain Si(100) prior to GaPN growth and compare the GaP{sub 0.98}N{sub 0.02}/Si(100) surface preparation to established P- and Ga-rich surfaces of GaP/Si(100). We apply reflection anisotropy spectroscopy to study the surface preparation of GaP{sub 0.98}N{sub 0.02} in situ in vapor phase epitaxy ambient and benchmark the signals to low energy electron diffraction, photoelectron spectroscopy, and x-ray diffraction. While the preparation of the Ga-rich surface is hardly influenced by the presence of the nitrogen precursor 1,1-dimethylhydrazine (UDMH), we find that stabilization with UDMH after growth hinders well-defined formation of the V-rich GaP{sub 0.98}N{sub 0.02}/Si(100) surface. Additional features in the reflection anisotropy spectra are suggested to be related to nitrogen incorporation in the GaP bulk.

  1. Nanostructured materials for hydrogen storage

    DOE Patents [OSTI]

    Williamson, Andrew J. (Pleasanton, CA); Reboredo, Fernando A. (Pleasanton, CA)

    2007-12-04T23:59:59.000Z

    A system for hydrogen storage comprising a porous nano-structured material with hydrogen absorbed on the surfaces of the porous nano-structured material. The system of hydrogen storage comprises absorbing hydrogen on the surfaces of a porous nano-structured semiconductor material.

  2. Integrating giant microwave absorption with magnetic refrigeration in one

    E-Print Network [OSTI]

    Wang, Wei Hua

    Integrating giant microwave absorption with magnetic refrigeration in one multifunctional with magnetic refrigeration in one multifunctional material. This integration not only advances our-compression/expansion refrigeration, magnetic refrigeration exhibits the advantages of high energy efficiency and environment

  3. Platinum dendritic nanoparticles with magnetic behavior

    SciTech Connect (OSTI)

    Li, Wenxian, E-mail: wl240@uowmail.edu.au [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522 (Australia); Solar Energy Technologies, School of Computing, Engineering, and Mathematics, University of Western Sydney, Penrith NSW 2751 (Australia); Sun, Ziqi; Nevirkovets, Ivan P.; Dou, Shi-Xue [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522 (Australia); Tian, Dongliang [Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry and the Environment, Beihang University, Beijing 100191 (China)

    2014-07-21T23:59:59.000Z

    Magnetic nanoparticles have attracted increasing attention for biomedical applications in magnetic resonance imaging, high frequency magnetic field hyperthermia therapies, and magnetic-field-gradient-targeted drug delivery. In this study, three-dimensional (3D) platinum nanostructures with large surface area that features magnetic behavior have been demonstrated. The well-developed 3D nanodendrites consist of plentiful interconnected nano-arms ?4?nm in size. The magnetic behavior of the 3D dendritic Pt nanoparticles is contributed by the localization of surface electrons due to strongly bonded oxygen/Pluronic F127 and the local magnetic moment induced by oxygen vacancies on the neighboring Pt and O atoms. The magnetization of the nanoparticles exhibits a mixed paramagnetic and ferromagnetic state, originating from the core and surface, respectively. The 3D nanodendrite structure is suitable for surface modification and high amounts of drug loading if the transition temperature was enhanced to room temperature properly.

  4. HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS

    E-Print Network [OSTI]

    Taylor, C.

    2011-01-01T23:59:59.000Z

    D. C. 'Niobium-Titanium Superconducting Material s ', in S.14, 1982 HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS C.SUMAG-68 HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS* C.

  5. Fast superconducting magnetic field switch

    DOE Patents [OSTI]

    Goren, Yehuda (Mountain View, CA); Mahale, Narayan K. (The Woodlands, TX)

    1996-01-01T23:59:59.000Z

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles.

  6. Earth materials and earth dynamics

    SciTech Connect (OSTI)

    Bennett, K; Shankland, T. [and others

    2000-11-01T23:59:59.000Z

    In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  7. Braze material for joining ceramic to metal and ceramic to ceramic surfaces and joined ceramic to metal and ceramic to ceramic article

    DOE Patents [OSTI]

    Hunt, Thomas K. (Ann Arbor, MI); Novak, Robert F. (Farmington Hills, MI)

    1991-01-01T23:59:59.000Z

    An improved active metal braze filler material is provided in which the coefficient of thermal expansion of the braze filler is more closely matched with that of the ceramic and metal, or two ceramics, to provide ceramic to metal, or ceramic to ceramic, sealed joints and articles which can withstand both high temperatures and repeated thermal cycling without failing. The braze filler material comprises a mixture of a material, preferably in the form of a powder, selected from the group consisting of molybdenum, tungsten, silicon carbide and mixtures thereof, and an active metal filler material selected from the group consisting of alloys or mixtures of nickel and titanium, alloys or mixtures of nickel and zirconium, alloys or mixtures of nickel, titanium, and copper, alloys or mixtures of nickel, titanium, and zirconium, alloys or mixtures of niobium and nickel, alloys or mixtures of niobium and zirconium, alloys or mixtures of niobium and titanium, alloys or mixtures of niobium, titanium, and nickel, alloys or mixtures of niobium, zirconium, and nickel, and alloys or mixtures of niobium, titanium, zirconium, and nickel. The powder component is selected such that its coefficient of thermal expansion will effect the overall coefficient of thermal expansion of the braze material so that it more closely matches the coefficients of thermal expansion of the ceramic and metal parts to be joined.

  8. Fresnel versus Kummer surfaces

    E-Print Network [OSTI]

    Peinke, Joachim

    Fresnel versus Kummer surfaces Alberto Favaro & Friedrich W. Hehl Outline Linear media Linear media-you. Fresnel versus Kummer surfaces: geometrical optics in dispersionless linear (meta)materials and vacuum, 19­23 November 2012 Email: favaro@thp.uni-koeln.de #12;Fresnel versus Kummer surfaces Alberto Favaro

  9. Regrowth of diluted magnetic semiconductor GaMnAs on InGaP (001) surfaces to realize freestanding micromechanical structures

    SciTech Connect (OSTI)

    Choi, Hyung Kook; Lee, Joon Sue; Cho, Sung Woon; Lee, Won Oh; Shim, Seung Bo; Park, Yun Daniel [CSCMR and FPRD Department of Physics and Astronomy, Seoul National University, NS 50, Seoul 151- 747 (Korea, Republic of)

    2007-03-15T23:59:59.000Z

    Low temperature molecular beam epitaxy regrowths of Ga{sub 1-x}Mn{sub x}As (x{approx_equal}0.04) diluted magnetic semiconductors on GaAs/In{sub 1-y}Ga{sub y}P/GaAs(001) and In{sub 1-y}Ga{sub y}P/GaAs(001) (y{approx_equal}0.51) heterostructures prepared by metal-organic chemical vapor deposition are described. The resulting Ga{sub 1-x}Mn{sub x}As properties are comparable to epitaxial films grown directly on GaAs (001) substrates from in situ reflection high-energy electron diffraction, x-ray diffraction, magnetometry, and transport measurements with magnetic ordering temperature of as-grown films to range between {approx}50 and {approx}60 K. Postgrowth low temperature annealing enhances both magnetic and transport properties. Perfect etch selectivity between Ga{sub 1-x}Mn{sub x}As/GaAs and In{sub 1-y}Ga{sub y}P is utilized to realize suspended Ga{sub 1-x}Mn{sub x}As/GaAs doubly clamped beam micromechanical freestanding structures.

  10. Acta Physicae Superficierum Vol VII 2004 EXPLORING ARTIFICIAL MAGNETISM

    E-Print Network [OSTI]

    Rau, Carl

    Acta Physicae Superficierum · Vol VII · 2004 EXPLORING ARTIFICIAL MAGNETISM FROM THIN FILMS of artificially structured, new magnetic materials play a fundamental role in modern science and technology. From thin films to patterned magnetic nano-structures, these magnetic materials and systems can be utilized

  11. Polyphosphazine-based polymer materials

    DOE Patents [OSTI]

    Fox, Robert V.; Avci, Recep; Groenewold, Gary S.

    2010-05-25T23:59:59.000Z

    Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

  12. Electrode Structures and Surfaces for Lithium Batteries | Argonne...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Structures and Surfaces for Lithium Batteries Technology available for licensing: Lithium-metal-oxide electrode materials with modified surfaces to protect the materials from...

  13. Moment free toroidal magnet

    DOE Patents [OSTI]

    Bonanos, Peter (East Brunswick, NJ)

    1983-01-01T23:59:59.000Z

    A toroidal magnet for confining a high magnetic field for use in fusion reactor research and nuclear particle detection. The magnet includes a series of conductor elements arranged about and fixed at its small major radius portion to the outer surface of a central cylindrical support each conductor element having a geometry such as to maintain the conductor elements in pure tension when a high current flows therein, and a support assembly which redistributes all or part of the tension which would otherwise arise in the small major radius portion of each coil element to the large major radius portion thereof.

  14. Int. J. Computational Materials Science and Surface Engineering, Vol. 2, Nos. 3/4, 2009 225 Copyright 2009 Inderscience Enterprises Ltd.

    E-Print Network [OSTI]

    , Silicon Carbide (SiC) has become an alternative material to replace Si for Microelectromechanical Systems; microelectromechanical systems; review; deposition; fabrication; devices; prospect. Reference to this paper should and the development of state-of-the-art SiC Microelectromechanical Systems (MEMS). She is currently a Research Council

  15. Joining of dissimilar materials

    DOE Patents [OSTI]

    Tucker, Michael C; Lau, Grace Y; Jacobson, Craig P

    2012-10-16T23:59:59.000Z

    A method of joining dissimilar materials having different ductility, involves two principal steps: Decoration of the more ductile material's surface with particles of a less ductile material to produce a composite; and, sinter-bonding the composite produced to a joining member of a less ductile material. The joining method is suitable for joining dissimilar materials that are chemically inert towards each other (e.g., metal and ceramic), while resulting in a strong bond with a sharp interface between the two materials. The joining materials may differ greatly in form or particle size. The method is applicable to various types of materials including ceramic, metal, glass, glass-ceramic, polymer, cermet, semiconductor, etc., and the materials can be in various geometrical forms, such as powders, fibers, or bulk bodies (foil, wire, plate, etc.). Composites and devices with a decorated/sintered interface are also provided.

  16. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOE Patents [OSTI]

    Hull, J.R.

    1997-08-05T23:59:59.000Z

    A method and apparatus are disclosed for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap. 4 figs.

  17. Direct Imaging of Asymmetric Magnetization Reversal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    new information storage and sensing devices. There are two basic energies involved in the manipulation and control of the magnetic properties of materials. Exchange controls...

  18. Estimation of Hourly Solar Loads on the Surfaces of Moving Refrigerated Tractor Trailers Outfitted with Phase Change Materials (PCMs) for Several Routes across the Continental U.S.

    E-Print Network [OSTI]

    Varadarajan, Krupasagar

    2011-08-31T23:59:59.000Z

    who constructed the machine [9]. James Harrison an Australian, who examined the previous refrigeration devices, came up with a concept of vapor- compression refrigeration for meat and dairy-products [9]. During the 1840?s... the transportation modes. 8 4. PCMs in refrigerated transportation Phase Change Materials (PCMs) offer a solution for reducing fuel consumption in refrigerated trucks. PCMs store and release energy during melting and freezing (i.e., while...

  19. Soiling of building envelope surfaces and its effect on solar reflectance - Part II: Development of an accelerate aging method for roofing materials

    SciTech Connect (OSTI)

    Sleiman, Mohamad; Kirchstetter, Thomas W.; Berdahl, Paul; Gilbert, Haley; Quelen, Sarah; Marlot, Lea; Preble, Chelsea; Chen, Sharon; Montalbano, Amadine; Rosseler, Olivier; Akbari, Hashem; Levinson, Ronnen; Destaillats, Hugo

    2013-11-18T23:59:59.000Z

    Highly reflective roofs can decrease the energy required for building air conditioning, help mitigate the urban heat island effect, and slow global warming. However, these benefits are diminished by soiling and weathering processes that reduce the solar reflectance of most roofing materials. Soiling results from the deposition of atmospheric particulate matter and the growth of microorganisms, each of which absorb sunlight. Weathering of materials occurs with exposure to water, sunlight, and high temperatures. This study developed an accelerated aging method that incorporates features of soiling and weathering. The method sprays a calibrated aqueous soiling mixture of dust minerals, black carbon, humic acid, and salts onto preconditioned coupons of roofing materials, then subjects the soiled coupons to cycles of ultraviolet radiation, heat and water in a commercial weatherometer. Three soiling mixtures were optimized to reproduce the site-specific solar spectral reflectance features of roofing products exposed for 3 years in a hot and humid climate (Miami, Florida); a hot and dry climate (Phoenix, Arizona); and a polluted atmosphere in a temperate climate (Cleveland, Ohio). A fourth mixture was designed to reproduce the three-site average values of solar reflectance and thermal emittance attained after 3 years of natural exposure, which the Cool Roof Rating Council (CRRC) uses to rate roofing products sold in the US. This accelerated aging method was applied to 25 products?single ply membranes, factory and field applied coatings, tiles, modified bitumen cap sheets, and asphalt shingles?and reproduced in 3 days the CRRC's 3-year aged values of solar reflectance. This accelerated aging method can be used to speed the evaluation and rating of new cool roofing materials.

  20. Magnetic cooling at Risoe DTU

    E-Print Network [OSTI]

    Nielsen, K K; Jensen, J B; Bahl, C R H; Pryds, N; Smith, A; Nordentoft, A; Hattel, J

    2009-01-01T23:59:59.000Z

    Magnetic refrigeration at room temperature is of great interest due to a long-term goal of making refrigeration more energy-efficient, less noisy and free of any environmentally hostile materials. A refrigerator utilizing an active magnetic regenerator (AMR) is based on the magnetocaloric effect, which manifests itself as a temperature change in magnetic materials when subjected to a varying magnetic field. In this work we present the current state of magnetic refrigeration research at Risoe DTU with emphasis on the numerical modeling of an existing AMR test machine. A 2D numerical heat-transfer and fluid-flow model that represents the experimental setup is presented. Experimental data of both no-heat load and heat load situations are compared to the model. Moreover, results from the numerical modeling of the permanent magnet design used in the system are presented.

  1. Functional Metalorganics --Magnetism, structure, transport

    E-Print Network [OSTI]

    -organic supramolecular materials at surfaces #12;FM2011 - 4 - Tuesday May 31 Session III: Molecular spectroscopies 09 substrates hold promise for the realization of single-molecule transistors. Spin-crossover materials

  2. Nanostructured composite reinforced material

    DOE Patents [OSTI]

    Seals, Roland D. (Oak Ridge, TN); Ripley, Edward B. (Knoxville, TN); Ludtka, Gerard M. (Oak Ridge, TN)

    2012-07-31T23:59:59.000Z

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  3. Tuning the Optical Properties of Nanoscale Materials on Surfaces Through Controlled Exchange Reactions on Cadmium Selenide Quantum Dots and Patterning of Gold and QD Nanoparticle Arrays

    E-Print Network [OSTI]

    Pravitasari, Arika

    2013-11-11T23:59:59.000Z

    and economical ways to pattern QDs with different optical and surface properties on the same platform. This could be beneficial for the development of some QD based devices, such as: QD based light emitting diodes (LED), where each emitted color can... photobleaching as compared to organic fluorophores.50 Applications of QDs have emerged in numerous areas such as bio-imaging,9 labeling and sensing,51 solar cells,7, 18, 52 and light emitting diodes (LEDs).16, 53-59 CdSe QDs were chosen for the interest...

  4. Magnetic Resonance Facility (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-03-01T23:59:59.000Z

    This fact sheet provides information about Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

  5. NANOSCALE STRUCTURALAND MAGNETIC CHARACTERIZATION USING

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    of novel nanoscale storage devices and sensors. However, for successful utilization, it is essential]. Such unique properties of magnetic thin films and nanostructures hold great promise for the development to the characterization of nanostructured magnetic materials. 2. ELECTRON MICROSCOPY METHODS In the transmission electron

  6. Magnetic metallic multilayers

    SciTech Connect (OSTI)

    Hood, R.Q.

    1994-04-01T23:59:59.000Z

    Utilizing self-consistent Hartree-Fock calculations, several aspects of multilayers and interfaces are explored: enhancement and reduction of the local magnetic moments, magnetic coupling at the interfaces, magnetic arrangements within each film and among non-neighboring films, global symmetry of the systems, frustration, orientation of the various moments with respect to an outside applied field, and magnetic-field induced transitions. Magnetoresistance of ferromagnetic-normal-metal multilayers is found by solving the Boltzmann equation. Results explain the giant negative magnetoresistance encountered in these systems when an initial antiparallel arrangement is changed into a parallel configuration by an external magnetic field. The calculation depends on (1) geometric parameters (thicknesses of layers), (2) intrinsic metal parameters (number of conduction electrons, magnetization, and effective masses in layers), (3) bulk sample properties (conductivity relaxation times), (4) interface scattering properties (diffuse scattering versus potential scattering at the interfaces, and (5) outer surface scattering properties (specular versus diffuse surface scattering). It is found that a large negative magnetoresistance requires considerable asymmetry in interface scattering for the two spin orientations. Features of the interfaces that may produce an asymmetrical spin-dependent scattering are studied: varying interfacial geometric random roughness with no lateral coherence, correlated (quasi-periodic) roughness, and varying chemical composition of the interfaces. The interplay between these aspects of the interfaces may enhance or suppress the magnetoresistance, depending on whether it increases or decreases the asymmetry in the spin-dependent scattering of the conduction electrons.

  7. Magnetic behaviour and magnetocaloric effect of neodymium-based amorphous alloy

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    magnetic refrigerant materials. a) Corresponding author ­ gorsse@icmcb-bordeaux.cnrs.fr hal-00267718 magnetization and demagnetization of the magnetic refrigerant. Families of magnetic materials which exhibit properties for a suitable magnetic refrigerants, e.g. a high electric resistivity that decreases eddy current

  8. Critical Materials Hub

    Broader source: Energy.gov [DOE]

    Critical materials, including some rare earth elements that possess unique magnetic, catalytic, and luminescent properties, are key resources needed to manufacture products for the clean energy economy. These materials are so critical to the technologies that enable wind turbines, solar panels, electric vehicles, and energy-efficient lighting that DOE's 2010 and 2011 Critical Materials Strategy reported that supply challenges for five rare earth metals—dysprosium, neodymium, terbium, europium, and yttrium—could affect clean energy technology deployment in the coming years.1, 2

  9. WAFER TEST CAVITY -Linking Surface Microstructure to RF Performance: a ‘Short-­?Sample Test Facility’ for characterizing superconducting materials for SRF cavities.

    SciTech Connect (OSTI)

    Pogue, Nathaniel; Comeaux, Justin; McIntyre, Peter

    2014-05-30T23:59:59.000Z

    The Wafer Test cavity was designed to create a short sample test system to determine the properties of the superconducting materials and S?I?S hetero?structures. The project, funded by ARRA, was successful in accomplishing several goals to achieving a high gradient test system for SRF research and development. The project led to the design and construction of the two unique cavities that each severed unique purposes: the Wafer test Cavity and the Sapphire Test cavity. The Sapphire Cavity was constructed first to determine the properties of large single crystal sapphires in an SRF environment. The data obtained from the cavity greatly altered the design of the Wafer Cavity and provided the necessary information to ascertain the Wafer Test cavity’s performance.

  10. Superconducting magnetic coil

    DOE Patents [OSTI]

    Aized, D.; Schwall, R.E.

    1999-06-22T23:59:59.000Z

    A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil. 15 figs.

  11. Superconducting magnetic coil

    DOE Patents [OSTI]

    Aized, Dawood (Marlboro, MA); Schwall, Robert E. (Northborough, MA)

    1999-06-22T23:59:59.000Z

    A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil.

  12. Validation of plasma shape reconstruction by Cauchy condition surface method in KSTAR

    SciTech Connect (OSTI)

    Miyata, Y.; Suzuki, T.; Ide, S. [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan)] [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan); Hahn, S. H.; Chung, J.; Bak, J. G.; Ko, W. H. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)

    2014-03-15T23:59:59.000Z

    Cauchy Condition Surface (CCS) method is a numerical approach to reconstruct the plasma boundary and calculate the quantities related to plasma shape using the magnetic diagnostics in real time. It has been applied to the KSTAR plasma in order to establish the plasma shape reconstruction with the high elongation of plasma shape and the large effect of eddy currents flowing in the tokamak structures for the first time. For applying the CCS calculation to the KSTAR plasma, the effects by the eddy currents and the ferromagnetic materials on the plasma shape reconstruction are studied. The CCS calculation includes the effect of eddy currents and excludes the magnetic diagnostics, which is expected to be influenced largely by ferromagnetic materials. Calculations have been performed to validate the plasma shape reconstruction in 2012 KSTAR experimental campaign. Comparison between the CCS calculation and non-magnetic measurements revealed that the CCS calculation can reconstruct the accurate plasma shape even with a small I{sub P}.

  13. Catalyst material and method of making

    DOE Patents [OSTI]

    Matson, Dean W. (Kennewick, WA); Fulton, John L. (Richland, WA); Linehan, John C. (Richland, WA); Bean, Roger M. (Richland, WA); Brewer, Thomas D. (Richland, WA); Werpy, Todd A. (Richland, WA); Darab, John G. (Richland, WA)

    1997-01-01T23:59:59.000Z

    The material of the present invention is a mixture of catalytically active material and carrier materials, which may be catalytically active themselves. Hence, the material of the present invention provides a catalyst particle that has catalytically active material throughout its bulk volume as well as on its surface. The presence of the catalytically active material throughout the bulk volume is achieved by chemical combination of catalytically active materials with carrier materials prior to or simultaneously with crystallite formation.

  14. System and method for manipulating domain pinning and reversal in ferromagnetic materials

    DOE Patents [OSTI]

    Silevitch, Daniel M.; Rosenbaum, Thomas F.; Aeppli, Gabriel

    2013-10-15T23:59:59.000Z

    A method for manipulating domain pinning and reversal in a ferromagnetic material comprises applying an external magnetic field to a uniaxial ferromagnetic material comprising a plurality of magnetic domains, where each domain has an easy axis oriented along a predetermined direction. The external magnetic field is applied transverse to the predetermined direction and at a predetermined temperature. The strength of the magnetic field is varied at the predetermined temperature, thereby isothermally regulating pinning of the domains. A magnetic storage device for controlling domain dynamics includes a magnetic hard disk comprising a uniaxial ferromagnetic material, a magnetic recording head including a first magnet, and a second magnet. The ferromagnetic material includes a plurality of magnetic domains each having an easy axis oriented along a predetermined direction. The second magnet is positioned adjacent to the magnetic hard disk and is configured to apply a magnetic field transverse to the predetermined direction.

  15. Magnetic switch for reactor control rod. [LMFBR

    DOE Patents [OSTI]

    Germer, J.H.

    1982-09-30T23:59:59.000Z

    A magnetic reed switch assembly is described for activating an electromagnetic grapple utilized to hold a control rod in position above a reactor core. In normal operation the magnetic field of a permanent magnet is short-circuited by a magnetic shunt, diverting the magnetic field away from the reed switch. The magnetic shunt is made of a material having a Curie-point at the desired release temperature. Above that temperature the material loses its ferromagnetic properties, and the magnetic path is diverted to the reed switch which closes and short-circuits the control circuit for the control rod electro-magnetic grapple which allows the control rod to drop into the reactor core for controlling the reactivity of the core.

  16. Bipolar pulse field for magnetic refrigeration

    DOE Patents [OSTI]

    Lubell, Martin S. (Oak Ridge, TN)

    1994-01-01T23:59:59.000Z

    A magnetic refrigeration apparatus includes first and second steady state magnets, each having a field of substantially equal strength and opposite polarity, first and second bodies made of magnetocaloric material disposed respectively in the influence of the fields of the first and second steady state magnets, and a pulsed magnet, concentric with the first and second steady state magnets, and having a field which cycles between the fields of the first and second steady state magnets, thereby cyclically magnetizing and demagnetizing and thus heating and cooling the first and second bodies. Heat exchange apparatus of suitable design can be used to expose a working fluid to the first and second bodies of magnetocaloric material. A controller is provided to synchronize the flow of working fluid with the changing states of magnetization of the first and second bodies.

  17. Bipolar pulse field for magnetic refrigeration

    DOE Patents [OSTI]

    Lubell, M.S.

    1994-10-25T23:59:59.000Z

    A magnetic refrigeration apparatus includes first and second steady state magnets, each having a field of substantially equal strength and opposite polarity, first and second bodies made of magnetocaloric material disposed respectively in the influence of the fields of the first and second steady state magnets, and a pulsed magnet, concentric with the first and second steady state magnets, and having a field which cycles between the fields of the first and second steady state magnets, thereby cyclically magnetizing and demagnetizing and thus heating and cooling the first and second bodies. Heat exchange apparatus of suitable design can be used to expose a working fluid to the first and second bodies of magnetocaloric material. A controller is provided to synchronize the flow of working fluid with the changing states of magnetization of the first and second bodies. 2 figs.

  18. Pocked surface neutron detector

    DOE Patents [OSTI]

    McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

    2003-04-08T23:59:59.000Z

    The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

  19. Combinatorial synthesis of ceramic materials

    DOE Patents [OSTI]

    Lauf, Robert J. (Oak Ridge, TN) [Oak Ridge, TN; Walls, Claudia A. (Oak Ridge, TN) [Oak Ridge, TN; Boatner, Lynn A. (Oak Ridge, TN) [Oak Ridge, TN

    2010-02-23T23:59:59.000Z

    A combinatorial library includes a gelcast substrate defining a plurality of cavities in at least one surface thereof; and a plurality of gelcast test materials in the cavities, at least two of the test materials differing from the substrate in at least one compositional characteristic, the two test materials differing from each other in at least one compositional characteristic.

  20. Combinatorial synthesis of ceramic materials

    DOE Patents [OSTI]

    Lauf, Robert J.; Walls, Claudia A.; Boatner, Lynn A.

    2006-11-14T23:59:59.000Z

    A combinatorial library includes a gelcast substrate defining a plurality of cavities in at least one surface thereof; and a plurality of gelcast test materials in the cavities, at least two of the test materials differing from the substrate in at least one compositional characteristic, the two test materials differing from each other in at least one compositional characteristic.

  1. Laser surface cleaning

    SciTech Connect (OSTI)

    Crivella, E.C.; Freiwald, J.; Freiwald, D.A.

    1996-12-31T23:59:59.000Z

    Decontamination of contaminated metal and material recycle, two of 31 priority needs identified by the D&D focus group, are the most promising applications for laser ablation within the DOE complex. F2 Associates has developed a robotic laser ablation system that is capable of high contamination rates, waste volume reduction, surface pore cleaning, and real-time characterization of materials. It is being demonstrated that this system will be the most cost-effective technology for metal decontamination and material recycle.

  2. Notes on Magnetic Circuits ME 104, Prof. B. Paden

    E-Print Network [OSTI]

    Paden, Brad

    permeablility , is wound with N turns of wire. The toroid material may be any "soft" magnetic material that is magnetized when current is in the coil and then looses its magnetization when the current is turned off form: H J× = r r (2) where J r is the current density. In integral form we have D DR R H dl J d

  3. Velocity damper for electromagnetically levitated materials

    DOE Patents [OSTI]

    Fox, Richard J. (Oak Ridge, TN)

    1994-01-01T23:59:59.000Z

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation.

  4. Velocity damper for electromagnetically levitated materials

    DOE Patents [OSTI]

    Fox, R.J.

    1994-06-07T23:59:59.000Z

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material is disclosed. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation. 1 fig.

  5. INVESTIGATION OF BREAKDOWN INDUCED SURFACE DAMAGE ON 805 MHZ PILLBOX CAVITY INTERIOR SURFACES

    SciTech Connect (OSTI)

    Jana, M.R.; Chung, M.; Leonova, M.; Moretti, A.; Tollestrup,A.; Yonehara, K.; Freemire, B.; Torun, Y.; Bowring, D.; Flanagan, G.

    2013-09-25T23:59:59.000Z

    The MuCool Test Area (MTA) at Fermilab is a facility to develop the technology required for ionization cooling for a future Muon Collider and/or Neutrino Factory. As part of this research program, we have tested two 805 MHz vacuum RF cavities in a multi-Tesla magnetic field to study the effects of the static magnetic field on the cavity operation. This study gives useful information on field emitters in the cavity, dark current, surface conditioning, breakdown mechanisms and material properties of the cavity. All these factors determine the maximum accelerating gradient in the cavity. This paper discusses the image processing technique for quantitative estimation of spark damage spot distribution on cavity interior surfaces. The distribution is compared with the electric field distribution predicted by a computer code calculation. The local spark density is proportional to probability of surface breakdown and shows a power law dependence on the maximum electric field (E). This E dependence is consistent with the dark current calculated from the Fowler-Nordheim equation.

  6. Covetic Materials

    Energy Savers [EERE]

    Can re-melt, dilute, alloy... Fabrication of Covetic Materials - Nanocarbon Infusion 3 4 Technical Approach Unusual Characteristics of Covetic Materials ("covalent" &...

  7. Workshop on innovation in materials processing and manufacture: Exploratory concepts for energy applications

    SciTech Connect (OSTI)

    Horton, L.L. [comp.

    1993-06-01T23:59:59.000Z

    The goal of the workshop was to bring together industrial, academic, and DOE Laboratory personnel to discuss and identify potential areas for which creative, innovative, and/or multidisciplinary solutions could result in major payoffs for the nation`s energy economy, DOE, and industry. The topics emphasized in these discussions were: surfaces and interfacial processing technologies, biomolecular materials, powder/precursor technologies, magnetic materials, nanoscale materials, novel ceramics and composites, novel intermetallics and alloys, environmentally benign materials, and energy efficiency. The workshop had a 2-day format. One the first day, there was an introductory session that summarized future directions within DOE`s basic and materials technology programs, and the national studies on manufacturing and materials science and engineering. The balance of the workshop was devoted to brainstorming sessions by seven working groups. During the first working group session, the entire group was divided to discuss topics on: challenges for hostile environments, novel materials in transportation technologies, novel nanoscale materials, and opportunities in biomolecular materials. For the second session, the entire group (except for the working group on biomolecular materials) was reconfigured into new working groups on: alternative pathways to energy efficiency, environmentally benign materials and processes, and waste treatment and reduction: a basic sciences approach. This report contains separate reports from each of the seven working groups.

  8. Rock magnetic investigation of possible sources of the Bangui magnetic anomaly1 , M., Quesnel2*

    E-Print Network [OSTI]

    Boyer, Edmond

    Rock magnetic investigation of possible sources of the Bangui magnetic anomaly1 2 Ouabego1,2 , M slices of such28 metamorphic rocks, or by an iron-rich mafic source, or by a combination of these two29 source using constraints19 from satellite and ground magnetic field measurements, as well as from surface

  9. Structure, Magnetism, and Transport of CuCr2Se4 Thin Films

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    Structure, Magnetism, and Transport of CuCr 2 Se 4 Thindichroism shows that the magnetism persists to the surfacesuch as the nature of magnetism at surfaces and interfaces.

  10. Magnetic anisotropy in Fe-25Cr-12Co-1Si alloy induced by external magnetic field

    E-Print Network [OSTI]

    Qin, Lu-Chang

    Magnetic anisotropy in Fe-25Cr-12Co-1Si alloy induced by external magnetic field ZHEN Liang( )1 of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; 2. Department 27599-3255, USA Received 29 June 2006; accepted 15 January 2007 Abstract: Structural and magnetic

  11. High anisotropy materials for magnetic nanotechnologies

    E-Print Network [OSTI]

    Shipton, Erik G.

    2011-01-01T23:59:59.000Z

    anisotropy in rare earth transition metal alloys originatesfor transition metals than for rare earth. The atomicmetal sublattice and negative exchange between the CoPd and the rare earth

  12. Permanent Magnetic Materials Discovery | The Ames Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeedingBiomassPPPO WebsitePalmsthe PriceOptimizationUSING C RAY'S

  13. Corrosion protective coating for metallic materials

    DOE Patents [OSTI]

    Buchheit, Rudolph G. (Albuquerque, NM); Martinez, Michael A. (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    Corrosion protective coatings for metallic materials, particularly aluminum and aluminum alloys, produced with simple, low-cost equipment and materials other than toxic metals or metal salts, or metal cyanides. The metallic material is cleaned, degreased, and deoxidized, the surface is converted to a substantially alkaline condition, and the surface is chemically sealed with inorganic metal compounds.

  14. Corrosion protective coating for metallic materials

    DOE Patents [OSTI]

    Buchheit, R.G.; Martinez, M.A.

    1998-05-26T23:59:59.000Z

    Corrosion protective coatings for metallic materials, particularly aluminum and aluminum alloys, produced with simple, low-cost equipment and materials other than toxic metals or metal salts, or metal cyanides is disclosed. The metallic material is cleaned, degreased, and deoxidized, the surface is converted to a substantially alkaline condition, and the surface is chemically sealed with inorganic metal compounds. 1 fig.

  15. Materials Scientist

    Broader source: Energy.gov [DOE]

    Alternate Title(s):Materials Research Engineer; Metallurgical/Chemical Engineer; Product Development Manager;

  16. Magnetic switch for reactor control rod

    DOE Patents [OSTI]

    Germer, John H. (San Jose, CA)

    1986-01-01T23:59:59.000Z

    A magnetic reed switch assembly for activating an electromagnetic grapple utilized to hold a control rod in position above a reactor core. In normal operation the magnetic field of a permanent magnet is short-circuited by a magnetic shunt, diverting the magnetic field away from the reed switch. The magnetic shunt is made of a material having a Curie-point at the desired release temperature. Above that temperature the material loses its ferromagnetic properties, and the magnetic path is diverted to the reed switch which closes and short-circuits the control circuit for the control rod electromagnetic grapple which allows the control rod to drop into the reactor core for controlling the reactivity of the core.

  17. LDRD-LW Final Report: 07-LW-041 "Magnetism in Semiconductor Nanocrystals: New Physics at the Nanoscale"

    SciTech Connect (OSTI)

    Meulenberg, R W; Lee, J I; McCall, S K

    2009-10-19T23:59:59.000Z

    The work conducted in this project was conducted with the aim of identifying and understanding the origin and mechanisms of magnetic behavior in undoped semiconductor nanocrystals (NCs), specifically those composed of CdSe. It was anticipated that the successful completion of this task would have the effect of addressing and resolving significant controversy over this topic in the literature. Meanwhile, application of the resultant knowledge was expected to permit manipulation of the magnetic properties, particularly the strength of any magnetic effects, which is of potential relevance in a range of advanced technologies. More specifically, the project was designed and research conducted with the goal of addressing the following series of questions: (1) How does the magnitude of the magnetism in CdSe NCs change with the organic molecules used to passivate their surface the NC size? i.e. Is the magnetism an intrinsic effect in the nanocrystalline CdSe (as observed for Au NCs) or a surface termination driven effect? (2) What is the chemical (elemental) nature of the magnetism? i.e. Are the magnetic effects associated with the Cd atoms or the Se atoms or both? (3) What is/are the underlying mechanism(s)? (4) How can the magnetism be controlled for further applications? To achieve this goal, several experimental/technical milestones were identified to be fulfilled during the course of the research: (A) The preparation of well characterized CdSe NCs with varying surface termination (B) Establishing the extent of the magnetism of these NCs using magnetometry (particularly using superconducting interference device [SQUID]) (C) Establishing the chemical nature of the magnetism using x-ray magnetic circular dichroism (XMCD) - the element specific nature of the technique allows identification of the element responsible for the magnetism (D) Identification of the effect of surface termination on the empty densities of states (DOS) using x-ray absorption spectroscopy (XAS), with particular emphasis on elucidating small changes in the d-electron count. Characterizing changes in the d-electron density can yield important insight into the mechanisms of magnetism in materials. As the three attached manuscripts illustrate (presented in preprint form to ensure no infringement of copyright), each of these milestones was successfully illustrated and the results published in the scientific literature during the course of the project. The research team members were able to determine, from a series of XAS, XMCD and SQUID magnetometry measurements, that CdSe NCs are paramagnetic and that the magnitude of magnetic susceptibility is dependent upon the type of organic molecule used to passivate the NC surface (i.e. the observed magnetism results, at least in part, from a surface effect that is not intrinsic to the NCs). In addition, they identified that the mechanism by which the magnetic susceptibility is modified - via {pi} back-donation of d-electrons to the organic ligands from the Cd atoms. These findings demonstrate that the magnetic properties are related to the surface Cd atoms and illustrate the means by which the magnetic behavior can be manipulated for specific technological applications. Two of the papers published during the course of the LW project do not contain magnetometry data, but focus on the evolution in electronic structure of the CdSe NCs as a function of particle size. These measurements were crucial in developing an understanding of the electronic behavior of the NCs and, ultimately, in assigning the p back-donation mechanism for inducing controllable paramagnetic behavior. Significantly, the research team has also filed a patent application based upon their research: 'Method for Creating Ligand Induced Paramagnetism in Nanocrystalline Structures' Docket: IL-11858. It is noted that both LDRD-LW and Office of Basic Energy Sciences (OBES) funding is acknowledged in the attached manuscripts. As such, is important to indicate that funds were not comingled during the course of the project. Some of the experimental data presente

  18. Improving magnet designs with high and low field regions

    E-Print Network [OSTI]

    Bjørk, R; Smith, A; Pryds, N

    2014-01-01T23:59:59.000Z

    A general scheme for increasing the difference in magnetic flux density between a high and a low magnetic field region by removing unnecessary magnet material is presented. This is important in, e.g., magnetic refrigeration where magnet arrays has to deliver high field regions in close proximity to low field regions. Also, a general way to replace magnet material with a high permeability soft magnetic material where appropriate is discussed. As an example these schemes are applied to a two dimensional concentric Halbach cylinder design resulting in a reduction of the amount of magnet material used by 42% while increasing the difference in flux density between a high and a low field region by 45%.

  19. Magnetic Properties of Mesoporous and Nano-particulate Metal Oxides 

    E-Print Network [OSTI]

    Hill, Adrian H

    2009-01-01T23:59:59.000Z

    The magnetic properties of the first row transition metal oxides are wide and varied and have been studied extensively since the 1930’s. Observations that the magnetic properties of these material types change with the ...

  20. Induced magnetism in Cu nanoparticles embedded in Co P. Swaminathan

    E-Print Network [OSTI]

    Weaver, John H.

    the effects of changing the nature of confinement to three dimensions by embedding Cu nanoparticles in a Co.1063/1.2806236 Nonmagnetic spacer layers grown between layers of magnetic materials exhibit an induced magnetic moment.1

  1. Immobilized lipid-bilayer materials

    DOE Patents [OSTI]

    Sasaki, Darryl Y. (Albuquerque, NM); Loy, Douglas A. (Albuquerque, NM); Yamanaka, Stacey A. (Dallas, TX)

    2000-01-01T23:59:59.000Z

    A method for preparing encapsulated lipid-bilayer materials in a silica matrix comprising preparing a silica sol, mixing a lipid-bilayer material in the silica sol and allowing the mixture to gel to form the encapsulated lipid-bilayer material. The mild processing conditions allow quantitative entrapment of pre-formed lipid-bilayer materials without modification to the material's spectral characteristics. The method allows for the immobilization of lipid membranes to surfaces. The encapsulated lipid-bilayer materials perform as sensitive optical sensors for the detection of analytes such as heavy metal ions and can be used as drug delivery systems and as separation devices.

  2. Many-body Interactions in Magnetic Films and Nanostructures

    SciTech Connect (OSTI)

    Stephen D. Kevan

    2012-12-12T23:59:59.000Z

    We describe results supported by DOE grant DE-FG02-04ER46158, which focused on magnetic interaction at surfaces, in thin films, and in metallic nanostructures. We report on three general topics: 1) The Rashba spin splitting at magnetic surfaces of rare earth metals, 2) magnetic nanowires self-assembled on stepped tungsten single crystals, and 3) magnetic interaction in graphene films doped with hydrogen atoms.

  3. Superconductive imaging surface magnetometer

    DOE Patents [OSTI]

    Overton, Jr., William C. (Los Alamos, NM); van Hulsteyn, David B. (Santa Fe, NM); Flynn, Edward R. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    An improved pick-up coil system for use with Superconducting Quantum Interference Device gradiometers and magnetometers involving the use of superconducting plates near conventional pick-up coil arrangements to provide imaging of nearby dipole sources and to deflect environmental magnetic noise away from the pick-up coils. This allows the practice of gradiometry and magnetometry in magnetically unshielded environments. One embodiment uses a hemispherically shaped superconducting plate with interior pick-up coils, allowing brain wave measurements to be made on human patients. another embodiment using flat superconducting plates could be used in non-destructive evaluation of materials.

  4. Magnetic Field Safety Magnetic Field Safety

    E-Print Network [OSTI]

    McQuade, D. Tyler

    Magnetic Field Safety Training #12;Magnetic Field Safety Strong Magnetic Fields exist around energized magnets. High magnetic fields alone are a recognized hazard only for personnel with certain medical conditions such as pacemakers, magnetic implants, or embedded shrapnel. In addition, high magnetic

  5. Strange Magnetism

    E-Print Network [OSTI]

    Thomas R. Hemmert; Ulf-G. Meissner; Sven Steininger

    1998-11-09T23:59:59.000Z

    We present an analytic and parameter-free expression for the momentum dependence of the strange magnetic form factor of the nucleon and its corresponding radius which has been derived in Heavy Baryon Chiral Perturbation Theory. We also discuss a model-independent relation between the isoscalar magnetic and the strange magnetic form factors of the nucleon based on chiral symmetry and SU(3) only. These limites are used to derive bounds on the strange magnetic moment of the proton from the recent measurement by the SAMPLE collaboration.

  6. Method of passivating semiconductor surfaces

    DOE Patents [OSTI]

    Wanlass, Mark W. (Golden, CO)

    1990-01-01T23:59:59.000Z

    A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  7. Method of passivating semiconductor surfaces

    DOE Patents [OSTI]

    Wanlass, M.W.

    1990-06-19T23:59:59.000Z

    A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  8. Simulation of Non-linear SRF losses derived from characteristic Nb topography: comparison of etched and electropolished surfaces

    E-Print Network [OSTI]

    Xu, Chen; Kelley, Michael J

    2014-01-01T23:59:59.000Z

    A simplified numerical model has been developed to simulate non-linear superconducting rf losses on Nb surfaces due exclusively to topographical enhancement of surface magnetic fields. If local sharp edges are small enough, at locations where local surface fields exceed Hc, small volumes of material may become normal conducting without thermal runaway leading to quench. These small volumes of normal material yield increases in the effective surface resistance of the Nb. Using topographic data from typical BCP'd and EP'd fine grain niobium, we have simulated field-dependent losses and find that when extrapolated to resulting cavity performance, these losses correspond well to characteristic BCP/EP high field Q0 performance differences for fine grain Nb. We describe the structure of the model, its limitations, and the effects of this type of non-linear loss contribution on SRF cavity performance.

  9. Combinatorial sythesis of organometallic materials

    DOE Patents [OSTI]

    Schultz, Peter G. (Oakland, CA); Xiang, Xiaodong (Alameda, CA); Goldwasser, Isy (Alameda, CA)

    2002-07-16T23:59:59.000Z

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  10. Combinatorial synthesis of novel materials

    DOE Patents [OSTI]

    Schultz, Peter G. (Oakland, CA); Xiang, Xiaodong (Alameda, CA); Goldwasser, Isy (Alameda, CA)

    1999-01-01T23:59:59.000Z

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  11. Combinatorial synthesis of novel materials

    DOE Patents [OSTI]

    Schultz, Peter G. (Oakland, CA); Xiang, Xiaodong (Alameda, CA); Goldwasser, Isy (Menlo Park, CA)

    2001-01-01T23:59:59.000Z

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  12. Combinatorial synthesis of novel materials

    DOE Patents [OSTI]

    Schultz, Peter G. (Oakland, CA); Xiang, Xiaodong (Alameda, CA); Goldwasser, Isy (Alameda, CA)

    2002-02-12T23:59:59.000Z

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  13. Combinatorial synthesis of novel materials

    DOE Patents [OSTI]

    Schultz, Peter G. (Oakland, CA); Xiang, Xiaodong (Alameda, CA); Goldwasser, Isy (Menlo Park, CA)

    1999-12-21T23:59:59.000Z

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  14. Materials Characterization Capabilities at the HTML: Surface/Sub-surface

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment3311, 3312), October 20122 DOE Hydrogenis Winding6 *ofdislocation

  15. Magnetic shielding design analysis

    SciTech Connect (OSTI)

    Kerns, J.A.; LaPaz, A.D.; Fabyan, J.

    1983-12-27T23:59:59.000Z

    Two passive magnetic-shielding-design approaches for static external fields are reviewed. The first approach uses the shielding solutions for spheres and cylinders while the second approach requires solving Maxwell's equations. Experimental data taken at LLNL are compared with the results from these shieldings-design methods, and improvements are recommended for the second method. Design considerations are discussed here along with the importance of material gaps in the shield.

  16. Structures and magnetism of cyano-bridged grid-like two-dimensional 4f3d arrays{{

    E-Print Network [OSTI]

    Gao, Song

    ) besides the SmCo5 and Nd2Fe14B permanent magnets, many magnetically ordered molecule-based materials

  17. Geotoxic materials in the surface environment

    SciTech Connect (OSTI)

    Koranda, J.J.; Cohen, J.J.; Smith, C.F.; Ciminesi, F.J.

    1981-12-07T23:59:59.000Z

    The toxicology and natural occurrence of several recognized geotoxic elements including arsenic, cadmium, chromium, nickel, lead, selenium, uranium, and vanadium is reviewed. The behavior of these elements in the environment and in biological systems is examined. The properties of these eight toxic elements are summarized and presented in a toxicity matrix. The toxicity matrix identifies each of the elements in terms of average crustal abundance, average soil concentration, drinking water standards, irrigation water standards, daily human intake, aquatic toxicity, phytotoxicity, mammalian toxicity, human toxicity, and bioaccumulation factors for fish. Fish are the major aquatic environment contribution to the human diet and bioaccumulation in aquatic ecosystems has been demonstrated to be an important factor in the cycling of elements in aquatic ecosystems. The toxicity matrix is used as a first approximation to rank the geotoxicity of elements for the purpose of focusing future efforts. The ranking from highest to lowest toxicity with respect to the toxicity parameters being discussed is as follows: arsenic, cadmium, lead, selenium, chromium, vanadium, nickel, and uranium.

  18. Magnetic nanoparticles for applications in oscillating magnetic field

    SciTech Connect (OSTI)

    Peeraphatdit, Chorthip

    2010-12-15T23:59:59.000Z

    Enzymatic and thermochemical catalysis are both important industrial processes. However, the thermal requirements for each process often render them mutually exclusive: thermochemical catalysis requires high temperature that denatures enzymes. One of the long-term goals of this project is to design a thermocatalytic system that could be used with enzymatic systems in situ to catalyze reaction sequences in one pot; this system would be useful for numerous applications e.g. conversion of biomass to biofuel and other commodity products. The desired thermocatalytic system would need to supply enough thermal energy to catalyze thermochemical reactions, while keeping the enzymes from high temperature denaturation. Magnetic nanoparticles are known to generate heat in an oscillating magnetic field through mechanisms including hysteresis and relaxational losses. We envisioned using these magnetic nanoparticles as the local heat source embedded in sub-micron size mesoporous support to spatially separate the particles from the enzymes. In this study, we set out to find the magnetic materials and instrumental conditions that are sufficient for this purpose. Magnetite was chosen as the first model magnetic material in this study because of its high magnetization values, synthetic control over particle size, shape, functionalization and proven biocompatibility. Our experimental designs were guided by a series of theoretical calculations, which provided clues to the effects of particle size, size distribution, magnetic field, frequency and reaction medium. Materials of theoretically optimal size were synthesized, functionalized, and their effects in the oscillating magnetic field were subsequently investigated. Under our conditions, the materials that clustered e.g. silica-coated and PNIPAM-coated iron oxides exhibited the highest heat generation, while iron oxides embedded in MSNs and mesoporous iron oxides exhibited the least bulk heating. It is worth noting that the specific loss power of PNIPAM-coated Fe{sub 3}O{sub 4} was peculiarly high, and the heat loss mechanism of this material remains to be elucidated. Since thermocatalysis is a long-term goal of this project, we also investigated the effects of the oscillating magnetic field system for the synthesis of 7-hydroxycoumarin-3-carboxylic acid. Application of an oscillating magnetic field in the presence of magnetic particles with high thermal response was found to effectively increase the reaction rate of the uncatalyzed synthesis of the coumarin derivative compared to the room temperature control.

  19. Electric control of magnetization relaxation in thin film magnetic insulators.

    SciTech Connect (OSTI)

    Wang, Z.; Sun, Y.; Song, Y-Y.; Wu, M.; Schultheiss, H.; Pearson, J. E.; Hoffmann, A. (Materials Science Division); (Colorado State Univ.)

    2011-10-01T23:59:59.000Z

    Control of magnetization relaxation in magnetic insulators via interfacial spin scattering is demonstrated. The experiments use nanometer-thick yttrium iron garnet (YIG)/Pt layered structures, with the Pt layer biased by an electric voltage. The bias voltage produces a spin current across the Pt thickness. As this current scatters off the YIG surface, it exerts a torque on the YIG surface spins. This torque can reduce or enhance the damping and thereby decrease or increase the ferromagnetic resonance linewidth of the YIG film, depending on the field/current configuration.

  20. Direct torsional actuation of microcantilevers using magnetic excitation

    SciTech Connect (OSTI)

    Gosvami, Nitya Nand; Nalam, Prathima C.; Tam, Qizhan; Carpick, Robert W., E-mail: carpick@seas.upenn.edu [Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Exarhos, Annemarie L.; Kikkawa, James M. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-09-01T23:59:59.000Z

    Torsional mode dynamic force microscopy can be used for a wide range of studies including mapping lateral contact stiffness, torsional frequency or amplitude modulation imaging, and dynamic friction measurements of various materials. Piezo-actuation of the cantilever is commonly used, but it introduces spurious resonances, limiting the frequency range that can be sampled, and rendering the technique particularly difficult to apply in liquid medium where the cantilever oscillations are significantly damped. Here, we demonstrate a method that enables direct torsional actuation of cantilevers with high uniformity over wide frequency ranges by attaching a micrometer-scale magnetic bead on the back side of the cantilever. We show that when beads are magnetized along the width of the cantilever, efficient torsional actuation of the cantilevers can be achieved using a magnetic field produced from a solenoid placed underneath the sample. We demonstrate the capability of this technique by imaging atomic steps on graphite surfaces in tapping mode near the first torsional resonance of the cantilever in dodecane. The technique is also applied to map the variations in the lateral contact stiffness on the surface of graphite and polydiacetylene monolayers.

  1. Optimized nanoporous materials.

    SciTech Connect (OSTI)

    Braun, Paul V. (University of Illinois at Urbana-Champaign, Urbana, IL); Langham, Mary Elizabeth; Jacobs, Benjamin W.; Ong, Markus D.; Narayan, Roger J. (North Carolina State University, Raleigh, NC); Pierson, Bonnie E. (North Carolina State University, Raleigh, NC); Gittard, Shaun D. (North Carolina State University, Raleigh, NC); Robinson, David B.; Ham, Sung-Kyoung (Korea Basic Science Institute, Gangneung, South Korea); Chae, Weon-Sik (Korea Basic Science Institute, Gangneung, South Korea); Gough, Dara V. (University of Illinois at Urbana-Champaign, Urbana, IL); Wu, Chung-An Max; Ha, Cindy M.; Tran, Kim L.

    2009-09-01T23:59:59.000Z

    Nanoporous materials have maximum practical surface areas for electrical charge storage; every point in an electrode is within a few atoms of an interface at which charge can be stored. Metal-electrolyte interfaces make best use of surface area in porous materials. However, ion transport through long, narrow pores is slow. We seek to understand and optimize the tradeoff between capacity and transport. Modeling and measurements of nanoporous gold electrodes has allowed us to determine design principles, including the fact that these materials can deplete salt from the electrolyte, increasing resistance. We have developed fabrication techniques to demonstrate architectures inspired by these principles that may overcome identified obstacles. A key concept is that electrodes should be as close together as possible; this is likely to involve an interpenetrating pore structure. However, this may prove extremely challenging to fabricate at the finest scales; a hierarchically porous structure can be a worthy compromise.

  2. MATERIALS ENGINEERING KEYWORDS: beryllium, stainless

    E-Print Network [OSTI]

    Abdou, Mohamed

    MATERIALS ENGINEERING KEYWORDS: beryllium, stainless steel, heat conductance EXPERIMENTAL SURFACES SUBJECTED TO NONUNIFORM THERMAL DEFORMATIONS ROBERT DEAN ABELSON and MOHAMED A. ABDOU* University of California, Los Angeles Mechanical and Aerospace Engineering Department 43-133 Engineering IV, Box 951597

  3. Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

    SciTech Connect (OSTI)

    Polzin, Kurt A.; Godfroy, Thomas J. [NASA Marshall Space Flight Center Propulsion Research and Technology Applications Branch/ER24, MSFC, AL 35812 (United States)

    2008-01-21T23:59:59.000Z

    A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 34.5 kPa, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.114 m{sup 3}/hr.

  4. Intense Magnetized Plasma-Wall Interaction

    SciTech Connect (OSTI)

    Bauer, Bruno S. [UNR] [UNR; Fuelling, Stephan [UNR] [UNR

    2013-11-30T23:59:59.000Z

    This research project studied wall-plasma interactions relevant to fusion science. Such interactions are a critical aspect of Magneto-Inertial Fusion (MIF) because flux compression by a pusher material, in particular the metal for the liner approach to MIF, involves strong eddy current heating on the surface of the pusher, and probably interactions and mixing of the pusher with the interior fuel during the time when fusion fuel is being burned. When the pusher material is a metal liner, high-energy-density conditions result in fascinating behavior. For example, "warm dense matter" is produced, for which material properties such as resistivity and opacity are not well known. In this project, the transformation into plasma of metal walls subjected to pulsed megagauss magnetic fields was studied with an experiment driven by the UNR 1 MA Zebra generator. The experiment was numerically simulated with using the MHRDR code. This simple, fundamental high-energy-density physics experiment, in a regime appropriate to MIF, has stimulated an important and fascinating comparison of numerical modeling codes and tables with experiment. In addition, we participated in developing the FRCHX experiment to compress a field-reversed-configuration (FRC) plasma with a liner, in collaboration with researchers from Air Force Research Laboratory and Los Alamos National Lab, and we helped develop diagnostics for the Plasma Liner Experiment (PLX) at LANL. Last, but not least, this project served to train students in high-energy-density physics.

  5. Formation of magnetic discontinuities through viscous relaxation

    SciTech Connect (OSTI)

    Kumar, Sanjay; Bhattacharyya, R. [Udaipur Solar Observatory, Physical Research Laboratory, Dewali, Bari Road, Udaipur-313001 (India); Smolarkiewicz, P. K. [European Centre for Medium-Range Weather Forecasts, Reading RG2 9AX (United Kingdom)

    2014-05-15T23:59:59.000Z

    According to Parker's magnetostatic theorem, tangential discontinuities in magnetic field, or current sheets (CSs), are generally unavoidable in an equilibrium magnetofluid with infinite electrical conductivity and complex magnetic topology. These CSs are due to a failure of a magnetic field in achieving force-balance everywhere and preserving its topology while remaining in a spatially continuous state. A recent work [Kumar, Bhattacharyya, and Smolarkiewicz, Phys. Plasmas 20, 112903 (2013)] demonstrated this CS formation utilizing numerical simulations in terms of the vector magnetic field. The magnetohydrodynamic simulations presented here complement the above work by demonstrating CS formation by employing a novel approach of describing the magnetofluid evolution in terms of magnetic flux surfaces instead of the vector magnetic field. The magnetic flux surfaces being the possible sites on which CSs develop, this approach provides a direct visualization of the CS formation, helpful in understanding the governing dynamics. The simulations confirm development of tangential discontinuities through a favorable contortion of magnetic flux surfaces, as the magnetofluid undergoes a topology-preserving viscous relaxation from an initial non-equilibrium state with twisted magnetic field. A crucial finding of this work is in its demonstration of CS formation at spatial locations away from the magnetic nulls.

  6. pH dependence of the electrochemical behavior of surfaces modified with a polymer derived from a monomer consisting of two viologen subunits linked by a quinone: evidence for rectification by synthetic molecular materials

    SciTech Connect (OSTI)

    Smith, D.K.; Lane, G.A.; Wrighton, M.S.

    1986-06-11T23:59:59.000Z

    The authors report results concerning use of the surface-derivatizing reagent I that demonstrates a kind of rectification that is important in systems such as the photosynthetic apparatus. The important finding is that an electrode-bound redox polymer formed via hydrolysis of the Si-OMe bonds if O, (BV-Q-BV/sup 6 +/)/sub n/, undergoes a 4e/sup -//2H/sup +/ reduction, but below pH 5 only 2e/sup -/ can be electrochemically withdrawn from the reduced material. Reduction of quinone centers, Q, in the (BV-Q-BV/sup 6 +/)/sub n/ polymer to their dihydroxy form, QH/sub 2/, is mediated by the viologen, BV/sup 2+/+/, redox system, but the process cannot be reversed at low pH because the QH/sub 2/ is thermodynamically incapable of delivering charge back to the BV/sup 2 +/ centers. Direct equilibration of the electrode with the Q/QH/sub 2/ centers in the (BV-Q-BV/sup 6 +/)/sub n/ polymer does not occur. Relevance of the new finding to systems like the photosynthetic apparatus rests in the fact that charge separation in the photosynthetic system is achieved by a kind of rectification: the charge transport process involves a series of effectively unidirectional e/sup -/ transfer events.

  7. In-situ neutron scattering studies of magnetic shape memory alloys under stress, temperature, and magnetic fields

    SciTech Connect (OSTI)

    Brown, Donald W [Los Alamos National Laboratory; Sisneros, Thomas A [Los Alamos National Laboratory; Kabra, Saurabh [ANSTO/AUSTRALIA; Lograsso, Thomas A [AMES LAB; Schlagel, Deborah [AMES LAB

    2010-01-01T23:59:59.000Z

    We have utilized the SMARTS engineering neutron diffractometer to study the crystallographic orientation and phase transformations in the ferromagnetic shape memory alloy Ni 2MnGa under conditions of temperature (200-600K), stress (500MPa), and magnetic field (2T). Neutrons are uniquely suited to probe the crystallographic response of materials to external stimuli because of their high penetration, which allows them to sample the bulk of the material (as opposed to the surface) as well as pass through environmental chambers. A single crystal of Ni{sub 5}MnGa was repeatedly thermally cycled through the Austenitic-Martensitic phase transformation under varying conditions of applied stress, magnetic field or both. In-situ neutron diffraction was used to quantitatively monitor the population of the crystallographic variants in the martensitic phase as a function of the external stimuli during cooling. Neutron diffraction was used to monitor variant selection in the Ferromagnetic Shape Memory Alloy Ni{sub 2}Mn Ga during austenitic to martensitic transformation under varying conditions of externally applied stress and magnetic field. Qualitatively, the results were to be expected in this simple example. The shorter and magnetically soft c-axis of the tetragonal martensitic phase aligned with the compressive stress or magnetic field. However, neutron diffraction proved useful in directly quantifying the selection of the preferred variant by external influence. For instance, by quantifying the variant selection, the neutron diffraction results made apparent that the sample 'remembered' a loading cycle following a 'reset' cycle with no external applied stress. Moreover, the power of in-situ neutron diffraction will become more apparent when applied to more complex, less understood, samples such as polycrystalline samples or composite samples.

  8. Mechanics of abrasive wear of elastomeric materials

    E-Print Network [OSTI]

    Qi, Hang, 1971-

    2003-01-01T23:59:59.000Z

    Elastomeric materials are widely used as tire and sealing materials due to their ability to undergo large deformations and conform to the mating surface. However, their applications often result in repeated contact with ...

  9. The magnetic field in the dust ring at the center of the Galaxy

    SciTech Connect (OSTI)

    Hildebrand, R.H.; Gonatas, D.P.; Platt, S.R.; Wu, X.D.; Davidson, J.A.; Werner, M.W. (Chicago Univ., IL (USA) NASA, Ames Research Center, Moffett Field, CA (USA))

    1990-10-01T23:59:59.000Z

    Measurements of the polarization of the far-infrared thermal emission from six points in the dust ring at Sgr A are presented. The position angles are approximately perpendicular to the long axis of the ring as projected on the sky. The inferred magnetic field is therefore approximately in the plane of the ring. The pattern traced by the polarization vectors resembles that expected for a magnetic accretion disk. The measurements indicate a field in which the outward radial component is much greater than the axial component at the surface of the disk. The field thus appears to satisfy the condition proposed by Blandford and Payne (1982) for removing energy and angular momentum through centrifugal acceleration of surface material moving along the field lines. 31 refs.

  10. High magnetic field processing of liquid crystalline polymers

    DOE Patents [OSTI]

    Smith, Mark E. (Los Alamos, NM); Benicewicz, Brian C. (Los Alamos, NM); Douglas, Elliot P. (Los Alamos, NM)

    1998-01-01T23:59:59.000Z

    A process of forming bulk articles of oriented liquid crystalline thermoset material, the material characterized as having an enhanced tensile modulus parallel to orientation of an applied magnetic field of at least 25 percent greater than said material processed in the absence of a magnetic field, by curing a liquid crystalline thermoset precursor within a high strength magnetic field of greater than about 2 Tesla, is provided, together with a resultant bulk article of a liquid crystalline thermoset material, said material processed in a high strength magnetic field whereby said material is characterized as having a tensile modulus parallel to orientation of said field of at least 25 percent greater than said material processed in the absence of a magnetic field.

  11. High magnetic field processing of liquid crystalline polymers

    DOE Patents [OSTI]

    Smith, M.E.; Benicewicz, B.C.; Douglas, E.P.

    1998-11-24T23:59:59.000Z

    A process of forming bulk articles of oriented liquid crystalline thermoset material, the material characterized as having an enhanced tensile modulus parallel to orientation of an applied magnetic field of at least 25 percent greater than said material processed in the absence of a magnetic field, by curing a liquid crystalline thermoset precursor within a high strength magnetic field of greater than about 2 Tesla, is provided, together with a resultant bulk article of a liquid crystalline thermoset material, said material processed in a high strength magnetic field whereby said material is characterized as having a tensile modulus parallel to orientation of said field of at least 25 percent greater than said material processed in the absence of a magnetic field.

  12. Notes on Fridge Surfaces Laurel Swan

    E-Print Network [OSTI]

    Hunt, Galen

    a preliminary examination of refrigerator surfaces. The use and organiza- tion of items on fridge surfaces life, ethnography, interactive surfaces, refrigerators, magnets. ACM Classification Keywords H5.m, much talk has been bandied about concerning the importance of refrigerators in home life. Refrigerators

  13. Compliant layer chucking surface

    DOE Patents [OSTI]

    Blaedel, Kenneth L. (Dublin, CA); Spence, Paul A. (Pleasanton, CA); Thompson, Samuel L. (Pleasanton, CA)

    2004-12-28T23:59:59.000Z

    A method and apparatus are described wherein a thin layer of complaint material is deposited on the surface of a chuck to mitigate the deformation that an entrapped particle might cause in the part, such as a mask or a wafer, that is clamped to the chuck. The harder particle will embed into the softer layer as the clamping pressure is applied. The material composing the thin layer could be a metal or a polymer for vacuum or electrostatic chucks. It may be deposited in various patterns to affect an interrupted surface, such as that of a "pin" chuck, thereby reducing the probability of entrapping a particle.

  14. Chemical Functionalization of Nanostructured Materials Using Supercritical Reaction Media

    SciTech Connect (OSTI)

    Zemanian, Thomas S.; Fryxell, Glen E.; Liu, Jun; Mattigod, Shas V.; Shin, Yongsoon; Franz, James A.; Ustyugov, Oleksiy A.; Nie, Zimin

    2001-12-15T23:59:59.000Z

    There exists a need for durable and thin functional coatings to utilize the afforded surface area of highly porous ceramic materials. Deposition of silane-based Self Assembled Monolayers (SAMs) has thus far been limited to maximum coverages of 4-5 molecules/nm2 and long processing times (up to 2 weeks), due to the restricted internal geometry of the substrates. Results are presented for SAMs deposited on high surface area silica from supercritical fluids (SCFs). The SAMs so produced display unprecedented coverages, high monolayer integrity, and extremely low surface defect density. Moreover, the depositions and subsequent removal of reaction byproducts are complete in a matter of minutes rather than days. Nuclear Magnetic Resonance (NMR) spectra of the surface modified silica are presented, demonstrating the SAM integrity and evolution over time. Sorption of aqueous metal ions is demonstrated, and results are given demonstrating the broad pH stability of the deposited SAMs. A chemical explanation for the enhanced deposition is posited, and the kinetics of mass transport into and out of the nanostructured spaces are discussed.Related experiments using zeolite substrates show deposition of thiol-terminated silanes to internal surfaces of 6? microporous material. After oxidation of the thiol functional group size selective chemistry was demonstrated using the produced catalyst, proving the efficacy of the supercritical reaction medium for installing functional coatings inside pores of similar diameters to the chain length of the deposited molecule[]. Comparisons are made between the response of the different substrates to the supercritical fluid-based processing, and remarks on the utility of SCF based processing of nanostructured materials are presented.

  15. Saturable inductor and transformer structures for magnetic pulse compression

    DOE Patents [OSTI]

    Birx, Daniel L. (Londonderry, NH); Reginato, Louis L. (Orinda, CA)

    1990-01-01T23:59:59.000Z

    Saturable inductor and transformer for magnetic compression of an electronic pulse, using a continuous electrical conductor looped several times around a tightly packed core of saturable inductor material.

  16. active magnetic refrigerator: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    is active magnetic regenerator (AMR) refrigeration. This technology relies on solid materials exhibiting the magnetocaloric effect, (more) Dikeos, John 2006-01-01 2 Design...

  17. 21 Tesla mass spectrometry magnet arrives at EMSL | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and biological materials are one step closer to using EMSL's new 21 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer. The magnet, a critical piece of...

  18. Materials Sciences Division 1990 annual report

    SciTech Connect (OSTI)

    Not Available

    1990-01-01T23:59:59.000Z

    This report is the Materials Sciences Division's annual report. It contains abstracts describing materials research at the National Center for Electron Microscopy, and for research groups in metallurgy, solid-state physics, materials chemistry, electrochemical energy storage, electronic materials, surface science and catalysis, ceramic science, high tc superconductivity, polymers, composites, and high performance metals.

  19. Materials Sciences Division 1990 annual report

    SciTech Connect (OSTI)

    Not Available

    1990-12-31T23:59:59.000Z

    This report is the Materials Sciences Division`s annual report. It contains abstracts describing materials research at the National Center for Electron Microscopy, and for research groups in metallurgy, solid-state physics, materials chemistry, electrochemical energy storage, electronic materials, surface science and catalysis, ceramic science, high tc superconductivity, polymers, composites, and high performance metals.

  20. Surface Soil

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Surface Soil Surface Soil We compare local soil samples with samples collected from northern New Mexico locations that are beyond the range of potential influence from normal...