National Library of Energy BETA

Sample records for wave anisotropy cxs

  1. ORIGINAL PAPER Shear Wave Splitting and Mantle Anisotropy

    E-Print Network [OSTI]

    ORIGINAL PAPER Shear Wave Splitting and Mantle Anisotropy: Measurements, Interpretations, and New to make and interpret splitting measurements correctly and how to relate them properly to mantle flow and recent developments in the measurement and interpretation of shear wave splitting--including new

  2. P wave anisotropy, stress, and crack distribution at Coso geothermal...

    Open Energy Info (EERE)

    velocity and thus its perturbation, are represented by a symmetric positive definite matrix A instead of a scalar. The resulting anisotropy distribution is used to estimate...

  3. Stress-wave energy management through material anisotropy Alireza V. Amirkhizi, Aref Tehranian, Sia Nemat-Nasser

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    Stress-wave energy management through material anisotropy Alireza V. Amirkhizi, Aref Tehranian, Sia that if this axis initially coincides with the stress-wave vector, then the energy of the plane waves would closely the required anisotropy, and to experimentally demonstrate the management of stress-wave energy in a desired

  4. Statistical anisotropies in gravitational waves in solid inflation

    SciTech Connect (OSTI)

    Akhshik, Mohammad; Emami, Razieh; Firouzjahi, Hassan; Wang, Yi E-mail: emami@ipm.ir E-mail: yw366@cam.ac.uk

    2014-09-01

    Solid inflation can support a long period of anisotropic inflation. We calculate the statistical anisotropies in the scalar and tensor power spectra and their cross-correlation in anisotropic solid inflation. The tensor-scalar cross-correlation can either be positive or negative, which impacts the statistical anisotropies of the TT and TB spectra in CMB map more significantly compared with the tensor self-correlation. The tensor power spectrum contains potentially comparable contributions from quadrupole and octopole angular patterns, which is different from the power spectra of scalar, the cross-correlation or the scalar bispectrum, where the quadrupole type statistical anisotropy dominates over octopole.

  5. Stress-wave energy management through material anisotropy Alireza V. Amirkhizi, Aref Tehranian, Sia Nemat-Nasser

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    Stress-wave energy management through material anisotropy Alireza V. Amirkhizi, Aref Tehranian, Sia February 2010 Accepted 11 March 2010 Available online 27 March 2010 Stress-wave propagation in solids can that if this axis initially coincides with the stress-wave vector, then the energy of the plane waves would closely

  6. Lunar Laser-Ranging Detection of Light-Speed Anisotropy and Gravitational Waves

    E-Print Network [OSTI]

    Reginald T Cahill

    2010-02-03

    The Apache Point Lunar Laser-ranging Operation (APOLLO), in NM, can detect photon bounces from retro-reflectors on the moon surface to 0.1ns timing resolution. This facility enables not only the detection of light speed anisotropy, which defines a local preferred frame of reference - only in that frame is the speed of light isotropic, but also fluctuations/turbulence (gravitational waves) in the flow of the dynamical 3-space relative to local systems/observers. So the APOLLO facility can act as an effective "gravitational wave" detector. A recently published small data set from November 5, 2007, is analysed to characterise both the average anisotropy velocity and the wave/turbulence effects. The results are consistent with some 13 previous detections, with the last and most accurate being from the spacecraft earth-flyby Doppler-shift NASA data.

  7. TEMPERATURE ANISOTROPY IN THE PRESENCE OF ULTRA LOW FREQUENCY WAVES IN THE TERRESTRIAL FORESHOCK

    SciTech Connect (OSTI)

    Selzer, L. A.; Hnat, B.; Osman, K. T.; Nakariakov, V. M. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL (United Kingdom); Eastwood, J. P. [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College London, London (United Kingdom); Burgess, D., E-mail: L.A.Selzer@warwick.ac.uk [School of Physics and Astronomy, Queen Mary University of London (United Kingdom)

    2014-06-10

    We report the first study of the correlation between elevated solar wind core plasma temperatures and temperature anisotropy in the terrestrial foreshock. Plasma temperature is enhanced near the fire hose marginal stability threshold in the presence of ultra low frequency (ULF) large amplitude magnetic perturbations, which are intrinsically right-hand circularly polarized. Direct comparison of contemporaneous anisotropic temperatures in the upstream solar wind and the foreshock suggests that the net heating of plasma is mediated via increase of the parallel temperature in the foreshock region where the ULF waves are present. We consider the possibility that a mechanism based on Landau damping, where solar wind plasma temperature parallel to the background magnetic field is increased by interaction with oblique compressible fast magneto-acoustic ULF waves, influences temperature anisotropy.

  8. On the anisotropy of the gravitational wave background from massless preheating

    SciTech Connect (OSTI)

    Bethke, Laura; Rajantie, Arttu [Theoretical Physics, Blackett Laboratory, Imperial College, London, SW7 2AZ (United Kingdom); Figueroa, Daniel G., E-mail: laura.bethke06@imperial.ac.uk, E-mail: daniel.figueroa@unige.ch, E-mail: a.rajantie@imperial.ac.uk [Département de Physique Théorique and Center for Astroparticle Physics, Université de Genève, 24 quai Ernest Ansermet, CH–1211 Genève 4 (Switzerland)

    2014-06-01

    When a light scalar field is present during inflation, its value varies on superhorizon scales, modulating the preheating process at the end of inflation. Consequently, the amplitude of the gravitational wave (GW) background produced during preheating is also modulated. The observed energy density of this background appears therefore anisotropic at different angles in the sky. We provide a master formula for the angular power spectrum C{sub l} of the anisotropies in the GW background from preheating, valid for any scenario where the anisotropies are due to the superhorizon modulation of a light degree of freedom. Using lattice field theory simulations of massless preheating with g{sup 2}/? = 2, we find a flat angular spectrum l(l+1)C{sub l} ? 3 × 10{sup ?4}, which represents a strong anisotropy of ? 1% variations on large angular scales. For our choice of couplings, long wavelengths are amplified most strongly during parametric resonance, which is crucial for the development of the anisotropies. If future direct detection GW observatories are capable of detecting backgrounds of cosmological origin, they (may also) be able to detect this effect. This could eventually become a powerful tool to discriminate among inflationary and preheating scenarios.

  9. Anisotropies of gravitational-wave standard sirens as a new cosmological probe without redshift information

    E-Print Network [OSTI]

    Namikawa, Toshiya; Taruya, Atsushi

    2015-01-01

    Compact binary stars at cosmological distances are promising sources for gravitational waves (GWs), and these are thought to be powerful cosmological probes, referred to as the GW standard sirens. With future GW detectors such as the Einstein telescope (ET), we will be able to precisely measure their luminosity distances out to a redshift $z\\sim5$. While previously proposed cosmological studies using the GW standard sirens require redshift information for each source, which could be obtained through an extensive electromagnetic follow-up campaign, we here propose an alternative method only with the luminosity distances. Utilizing the anisotropies of the number density and luminosity distances originated from the large-scale structure, we discuss how this anisotropies can be measured and are sensitive to the cosmology, finding that the expected constraints on the primordial non-Gaussianity parameter $f_{\\rm NL}$ could become $\\sigma(f_{\\rm NL})=0.54$ with a network of ET-like detectors.

  10. Seismic Velocity Structure and Depth-Dependence of Anisotropy in the Red Sea and Arabian Shield from Surface Wave Analysis

    SciTech Connect (OSTI)

    Hansen, S; Gaherty, J; Schwartz, S; Rodgers, A; Al-Amri, A

    2007-07-25

    We investigate the lithospheric and upper mantle structure as well as the depth-dependence of anisotropy along the Red Sea and beneath the Arabian Peninsula using receiver function constraints and phase velocities of surface waves traversing two transects of stations from the Saudi Arabian National Digital Seismic Network. Frequency-dependent phase delays of fundamental-mode Love and Rayleigh waves, measured using a cross-correlation procedure, require very slow shear velocities and the presence of anisotropy throughout the upper mantle. Linearized inversion of these data produce path-averaged 1D radially anisotropic models with about 4% anisotropy in the lithosphere, increasing to about 4.8% anisotropy across the lithosphere-asthenosphere boundary (LAB). Models with reasonable crustal velocities in which the mantle lithosphere is isotropic cannot satisfy the data. The lithospheric lid, which ranges in thickness from about 70 km near the Red Sea coast to about 90 km beneath the Arabian Shield, is underlain by a pronounced low-velocity zone with shear velocities as low as 4.1 km/s. Forward models, which are constructed from previously determined shear-wave splitting estimates, can reconcile surface and body wave observations of anisotropy. The low shear velocity values are similar to many other continental rift and oceanic ridge environments. These low velocities combined with the sharp velocity contrast across the LAB may indicate the presence of partial melt beneath Arabia. The anisotropic signature primarily reflects a combination of plate- and density-driven flow associated with active rifting processes in the Red Sea.

  11. Optically induced spin wave dynamics in [Co/Pd]{sub 8} antidot lattices with perpendicular magnetic anisotropy

    SciTech Connect (OSTI)

    Pal, S.; Das, K.; Barman, A., E-mail: abarman@ybose.res.in [Thematic Unit of Excellence on Nanodevice Technology and Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Klos, J. W.; Gruszecki, P.; Krawczyk, M., E-mail: krawczyk@amu.edu.pl [Faculty of Physics, A. Mickiewicz University in Poznan, Umultowska 85, 61-614 Pozna? (Poland); Hellwig, O. [San Jose Research Center, HGST, a Western Digital Company, 3403 Yerba Buena Rd., San Jose, California 95135 (United States)

    2014-10-20

    We present an all-optical time-resolved measurement of spin wave (SW) dynamics in a series of antidot lattices based on [Co(0.75?nm)/Pd(0.9?nm)]{sub 8} multilayer (ML) systems with perpendicular magnetic anisotropy. The spectra depend significantly on the areal density of the antidots. The observed SW modes are qualitatively reproduced by the plane wave method. The interesting results found in our measurements and calculations at small lattice constants can be attributed to the increase of areal density of the shells with modified magnetic properties probably due to distortion of the regular ML structure by the Ga ion bombardment and to increased coupling between localized modes. We propose and discuss the possible mechanisms for this coupling including exchange interaction, tunnelling, and dipolar interactions.

  12. Stochastic acceleration of electrons by fast magnetosonic waves in solar flares: the effects of anisotropy in velocity and wavenumber space

    SciTech Connect (OSTI)

    Pongkitiwanichakul, Peera; Chandran, Benjamin D. G.

    2014-11-20

    We develop a model for stochastic acceleration of electrons in solar flares. As in several previous models, the electrons are accelerated by turbulent fast magnetosonic waves ({sup f}ast waves{sup )} via transit-time-damping (TTD) interactions. (In TTD interactions, fast waves act like moving magnetic mirrors that push the electrons parallel or anti-parallel to the magnetic field). We also include the effects of Coulomb collisions and the waves' parallel electric fields. Unlike previous models, our model is two-dimensional in both momentum space and wavenumber space and takes into account the anisotropy of the wave power spectrum F{sub k} and electron distribution function f {sub e}. We use weak turbulence theory and quasilinear theory to obtain a set of equations that describes the coupled evolution of F{sub k} and f {sub e}. We solve these equations numerically and find that the electron distribution function develops a power-law-like non-thermal tail within a restricted range of energies E in (E {sub nt}, E {sub max}). We obtain approximate analytic expressions for E {sub nt} and E {sub max}, which describe how these minimum and maximum energies depend upon parameters such as the electron number density and the rate at which fast-wave energy is injected into the acceleration region at large scales. We contrast our results with previous studies that assume that F{sub k} and f {sub e} are isotropic, and we compare one of our numerical calculations with the time-dependent hard-X-ray spectrum observed during the 1980 June 27 flare. In our numerical calculations, the electron energy spectra are softer (steeper) than in models with isotropic F{sub k} and f {sub e} and closer to the values inferred from observations of solar flares.

  13. Stress Wave Anisotropy in Centered Square Highly Nonlinear Granular Systems A. Leonard and C. Daraio

    E-Print Network [OSTI]

    Daraio, Chiara

    material layer [9]. Regarding the ability to redirect stress wave energy, more complex y-shaped granular. Daraio Graduate Aerospace Laboratories (GALCIT), California Institute of Technology, Pasadena, California

  14. PHYSICAL REVIEW A 90, 033613 (2014) Anisotropy in s-wave Bose-Einstein condensate collisions and its relationship to superradiance

    E-Print Network [OSTI]

    Kheruntsyan, Karen

    2014-01-01

    PHYSICAL REVIEW A 90, 033613 (2014) Anisotropy in s-wave Bose-Einstein condensate collisions. Boiron,2 C. I. Westbrook,2 and K. V. Kheruntsyan3 1 Institute of Physics, Polish Academy of Sciences process with Bose- Einstein-condensate collisions for which the angular distribution of scattered atom

  15. P wave material anisotropy of a tectono-metamorphic terrane: An active source seismic experiment at the KTB super-deep

    E-Print Network [OSTI]

    Okaya, David

    -metamorphic sub-terrane of the crystalline Bohemian massif. The experiment used multi-azimuth vertical seismic profiling whereby downhole sensors recorded surface seismic Vibroseis sources located along six 7.5-kmP wave material anisotropy of a tectono-metamorphic terrane: An active source seismic experiment

  16. Analysis of PS-converted wave seismic data in the presence of azimuthal anisotropy 

    E-Print Network [OSTI]

    Liu, Weining

    2014-11-27

    Shear-wave splitting and azimuthal variations of seismic attributes are two major anisotropic effects induced by vertically-aligned fractures. They both have influences on seismic data processing and interpretation, and ...

  17. Seismic anisotropy in the wedge above the Philippine Sea slab beneath Kanto and southwest Japan derived from shear wave splitting

    E-Print Network [OSTI]

    Seno, Tetsuzo

    Seismic anisotropy in the wedge above the Philippine Sea slab beneath Kanto and southwest Japan generated by shallow and intermediate-depth earthquakes occurring in the subducting Philippine Sea are further divided into PHS1 and PHS2 (upper and lower planes of the double seismic zone in the Philippine

  18. Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba(Fe1-xCox)2As2 above the Spin Density Wave Transition

    SciTech Connect (OSTI)

    Yi, Ming

    2011-08-19

    Nematicity, defined as broken rotational symmetry, has recently been observed in competing phases proximate to the superconducting phase in the cuprate high temperature superconductors. Similarly, the new iron-based high temperature superconductors exhibit a tetragonal to orthorhombic structural transition (i.e. a broken C{sub 4} symmetry) that either precedes or is coincident with a collinear spin density wave (SDW) transition in undoped parent compounds, and superconductivity arises when both transitions are suppressed via doping. Evidence for strong in-plane anisotropy in the SDW state in this family of compounds has been reported by neutron scattering, scanning tunneling microscopy, and transport measurements. Here we present an angle resolved photoemission spectroscopy study of detwinned single crystals of a representative family of electron-doped iron-arsenide superconductors, Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} in the underdoped region. The crystals were detwinned via application of in-plane uniaxial stress, enabling measurements of single domain electronic structure in the orthorhombic state. At low temperatures, our results clearly demonstrate an in-plane electronic anisotropy characterized by a large energy splitting of two orthogonal bands with dominant d{sub xz} and d{sub yz} character, which is consistent with anisotropy observed by other probes. For compositions x > 0, for which the structural transition (T{sub S}) precedes the magnetic transition (T{sub SDW}), an anisotropic splitting is observed to develop above T{sub SDW}, indicating that it is specifically associated with T{sub S}. For unstressed crystals, the band splitting is observed close to T{sub S}, whereas for stressed crystals the splitting is observed to considerably higher temperatures, revealing the presence of a surprisingly large in-plane nematic susceptibility in the electronic structure.

  19. Geophys. J. Znt. (1991) 107, 585-595 Inversion for subsurface anisotropy using estimates of shear-wave

    E-Print Network [OSTI]

    Edinburgh, University of

    1991-01-01

    cannot be adequately distinguished using vertical seismic profiles (VSPs), reflection profiles, and cross, and interpretation steps. profiles, to borehole measurements using vertical seismic Analysing seismic waves. VSPs are most suitable to monitor crack strike and density of parallel, vertical, aligned cracks

  20. Seismic response of fractures and induced anisotropy in poroelastic media

    E-Print Network [OSTI]

    Santos, Juan

    Seismic response of fractures and induced anisotropy in poroelastic media Juan E. Santos stituto) and R. Mart´inez Corredor (UNLP) Department of Mathematics, University of Calgary, October 2014 Seismic variations of velocity and attenuation of seismic waves. Seismic response of fractures and induced anisotropy

  1. Interpreting Power Anisotropy Measurements in Plasma Turbulence

    E-Print Network [OSTI]

    Chen, C H K; Horbury, T S; Schekochihin, A A

    2009-01-01

    A relationship between power anisotropy and wavevector anisotropy in turbulent fluctuations is derived. This can be used to interpret plasma turbulence measurements, for example in the solar wind. If fluctuations are anisotropic in shape then the ion gyroscale break point in spectra in the directions parallel and perpendicular to the magnetic field would not occur at the same frequency, and similarly for the electron gyroscale break point. This is an important consideration when interpreting solar wind observations in terms of anisotropic turbulence theories. Model magnetic field power spectra are presented assuming a cascade of critically balanced Alfven waves in the inertial range and kinetic Alfven waves in the dissipation range. The variation of power anisotropy with scale is compared to existing solar wind measurements and the similarities and differences are discussed.

  2. Semiclassical suppression of weak anisotropies of a generic Universe

    E-Print Network [OSTI]

    Marco Valerio Battisti; Riccardo Belvedere; Giovanni Montani

    2009-06-11

    A semiclassical mechanism which suppresses the weak anisotropies of an inhomogeneous cosmological model is developed. In particular, a wave function of this Universe having a meaningful probabilistic interpretation is obtained that is in agreement with the Copenhagen School. It describes the evolution of the anisotropies with respect to the isotropic scale factor which is regarded as a semiclassical variable playing an observer-like role. Near the cosmological singularity the solution spreads over all values of the anisotropies while, when the Universe expands sufficiently, the closed Friedmann-Robertson-Walker model appears to be the favorite state.

  3. Anisotropy and deformation in the Earth's mantle : seismological observations, geodynamical models, and laboratory experiments

    E-Print Network [OSTI]

    Long, Maureen Devaney

    2006-01-01

    In this thesis I report the results of several studies of elastic anisotropy and deformation in the Earth's mantle, using shear wave splitting measurements, numerical models of geodynamical processes, and laboratory ...

  4. CMB anisotropies from primordial inhomogeneous magnetic fields

    E-Print Network [OSTI]

    Antony Lewis

    2004-08-19

    Primordial inhomogeneous magnetic fields of the right strength can leave a signature on the CMB temperature anisotropy and polarization. Potentially observable contributions to polarization B-modes are generated by vorticity and gravitational waves sourced by the magnetic anisotropic stress. We compute the corresponding CMB transfer functions in detail including the effect of neutrinos. The shear rapidly causes the neutrino anisotropic stress to cancel the stress from the magnetic field, suppressing the production of gravitational waves and vorticity on super-horizon scales after neutrino decoupling. A significant large scale signal from tensor modes can only be produced before neutrino decoupling, and the actual amplitude is somewhat uncertain. Plausible values suggest primordial nearly scale invariant fields of ~ 10^(-10)G today may be observable from their large scale tensor anisotropy. They can be distinguished from primordial gravitational waves by their non-Gaussianity. Vector mode vorticity sources B-mode power on much smaller scales with a power spectrum somewhat similar to that expected from weak lensing, suggesting amplitudes ~ 10^(-9)G may be observable on small scales for a spectral index of n ~ -2.9. In the appendix we review the covariant equations for computing the vector and tensor CMB power spectra that we implement numerically.

  5. Seismic response of fractures and induced anisotropy in poroelastic media

    E-Print Network [OSTI]

    Santos, Juan

    Seismic response of fractures and induced anisotropy in poroelastic media Juan E. Santos Instituto) and R. Mart´inez Corredor (UNLP) Department of Mathematics, University of Calgary, October 2014 Seismic and angular variations of velocity and attenuation of seismic waves. Seismic response of fractures and induced

  6. SELF-CONSISTENT ION CYCLOTRON ANISOTROPY-BETA RELATION FOR SOLAR WIND PROTONS

    SciTech Connect (OSTI)

    Isenberg, Philip A.; Maruca, Bennett A.; Kasper, Justin C. E-mail: bmaruca@ssl.berkeley.edu

    2013-08-20

    We derive a set of self-consistent marginally stable states for a system of ion-cyclotron waves propagating parallel to the large-scale magnetic field through a homogeneous proton-electron plasma. The proton distributions and the wave dispersions are related through the condition that no further ion-cyclotron resonant particle scattering or wave growth/damping may take place. The thermal anisotropy of the protons in these states therefore defines the threshold value for triggering the proton-cyclotron anisotropy instability. A number of recent papers have noted that the anisotropy of solar wind protons at 1 AU does not seem to be limited by the proton-cyclotron anisotropy threshold, even at low plasma beta. However, this puzzle seems to be due solely to the estimation of this anisotropy threshold under the assumption that the protons have a bi-Maxwellian distribution. We note that bi-Maxwellian distributions are never marginally stable to the resonant cyclotron interaction, so these estimates do not represent physically valid thresholds. The threshold anisotropies obtained from our marginally stable states are much larger, as a function of proton parallel beta, than the bi-Maxwellian estimates, and we show that the measured data remains below these more rigorous thresholds. Thus, the results of this paper resolve the apparent contradiction presented by the solar wind anisotropy observations at 1 AU: the bi-Maxwellian anisotropies are not rigorous thresholds, and so do not limit the proton distributions in the solar wind.

  7. CMB Anisotropy Ned Wright, UCLA

    E-Print Network [OSTI]

    Wright, Edward L. "Ned"

    of Inflation · Quantum fluctuations occur uniformly throughout space- time · Future light cones have radii Saskatoon · QDMAP ­ Saskatoon on a balloon · TOCO ­ Saskatoon on a truck (Mobile Anisotropy Telescope

  8. Statistical anisotropy and cosmological quantum relaxation

    E-Print Network [OSTI]

    Antony Valentini

    2015-10-08

    We show that cosmological quantum relaxation predicts an anisotropic primordial power spectrum with a specific dependence on wavenumber k. We explore some of the consequences for precision measurements of the cosmic microwave background (CMB). Quantum relaxation is a feature of the de Broglie-Bohm pilot-wave formulation of quantum theory, which allows the existence of more general physical states that violate the Born probability rule. Recent work has shown that relaxation to the Born rule is suppressed for long-wavelength field modes on expanding space, resulting in a large-scale power deficit with a characteristic inverse-tangent dependence on k. Because the quantum relaxation dynamics is independent of the direction of the wave vector for the relaxing field mode, in the limit of weak anisotropy we are able to derive an expression for the anisotropic power spectrum that is determined by the power deficit function. As a result, the off-diagonal terms in the CMB covariance matrix are also determined by the power deficit. We show that the lowest-order l-(l+1) inter-multipole correlations have a characteristic scaling with multipole moment l. Our derived spectrum also predicts a residual statistical anisotropy at small scales, with an approximate consistency relation between the scaling of the l-(l+1) correlations and the scaling of the angular power spectrum at high l. We also predict a relationship between the l-(l+1) correlations at large and small scales. Cosmological quantum relaxation appears to provide a single physical mechanism that predicts both a large-scale power deficit and a range of statistical anisotropies, together with potentially testable relationships between them.

  9. Permeability anisotropy and resistivity anisotropy of mechanically compressed mudrocks

    E-Print Network [OSTI]

    Adams, Amy Lynn

    2014-01-01

    Permeability anisotropy (the ratio of the horizontal to vertical permeability) is an important parameter used in sedimentary basin models and geotechnical design to model fluid flow, locate hydrocarbon reserves and estimate ...

  10. Wind anisotropies and GRB progenitors

    E-Print Network [OSTI]

    Georges Meynet; Andre Maeder

    2007-01-17

    We study the effect of wind anisotropies on the stellar evolution leading to collapsars. Rotating models of a 60 M$_\\odot$ star with $\\Omega/\\Omega_{\\rm crit}=0.75$ on the ZAMS, accounting for shellular rotation and a magnetic field, with and without wind anisotropies, are computed at $Z$=0.002 until the end of the core He-burning phase. Only the models accounting for the effects of the wind anisotropies retain enough angular momentum in their core to produce a Gamma Ray Burst (GRB). The chemical composition is such that a type Ic supernova event occurs. Wind anisotropies appear to be a key physical ingredient in the scenario leading to long GRBs.

  11. Distinctive upper mantle anisotropy beneath the High Lava Plains and Eastern Snake River Plain,

    E-Print Network [OSTI]

    Distinctive upper mantle anisotropy beneath the High Lava Plains and Eastern Snake River Plain and continuing with the still- ongoing volcanism in the High Lava Plains (HLP) and eastern Snake River Plain (SRP waves; shear wave splitting; high lava plains; Snake River Plain; Yellowstone. Index Terms: 8137

  12. Anisotropy tuning with the Wilson flow

    E-Print Network [OSTI]

    S. Borsanyi; S. Durr; Z. Fodor; S. D. Katz; S. Krieg; T. Kurth; S. Mages; A. Schafer; K. K. Szabo

    2012-05-03

    We use the Wilson flow to define the gauge anisotropy at a given physical scale. We demonstrate the use of the anisotropic flow by performing the tuning of the bare gauge anisotropy in the tree-level Symanzik action for several lattice spacings and target anisotropies. We use this method to tune the anisotropy parameters in full QCD, where we also exploit the diminishing effect of a well chosen smearing on the renormalization of the fermion anisotropy.

  13. TACMB-1: The Theory of Anisotropies in the Cosmic Microwave Background (Bibliographic Resource Letter)

    E-Print Network [OSTI]

    Martin White; J. D. Cohn

    2002-03-07

    This Resource Letter provides a guide to the literature on the theory of anisotropies in the cosmic microwave background. Journal articles, web pages, and books are cited for the following topics: discovery, cosmological origin, early work, recombination, general CMB anisotropy references, primary CMB anisotropies (numerical, analytical work), secondary effects, Sunyaev-Zel'dovich effect(s), lensing, reionization, polarization, gravity waves, defects, topology, origin of fluctuations, development of fluctuations, inflation and other ties to particle physics, parameter estimation, recent constraints, web resources, foregrounds, observations and observational issues, and gaussianity.

  14. INSTABILITIES DRIVEN BY THE DRIFT AND TEMPERATURE ANISOTROPY OF ALPHA PARTICLES IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Verscharen, Daniel; Bourouaine, Sofiane; Chandran, Benjamin D. G. E-mail: s.bourouaine@unh.edu

    2013-08-20

    We investigate the conditions under which parallel-propagating Alfven/ion-cyclotron (A/IC) waves and fast-magnetosonic/whistler (FM/W) waves are driven unstable by the differential flow and temperature anisotropy of alpha particles in the solar wind. We focus on the limit in which w{sub Parallel-To {alpha}} {approx}> 0.25v{sub A}, where w{sub Parallel-To {alpha}} is the parallel alpha-particle thermal speed and v{sub A} is the Alfven speed. We derive analytic expressions for the instability thresholds of these waves, which show, e.g., how the minimum unstable alpha-particle beam speed depends upon w{sub Parallel-To {alpha}}/v{sub A}, the degree of alpha-particle temperature anisotropy, and the alpha-to-proton temperature ratio. We validate our analytical results using numerical solutions to the full hot-plasma dispersion relation. Consistent with previous work, we find that temperature anisotropy allows A/IC waves and FM/W waves to become unstable at significantly lower values of the alpha-particle beam speed U{sub {alpha}} than in the isotropic-temperature case. Likewise, differential flow lowers the minimum temperature anisotropy needed to excite A/IC or FM/W waves relative to the case in which U{sub {alpha}} = 0. We discuss the relevance of our results to alpha particles in the solar wind near 1 AU.

  15. Alamos National Laboratory] 71; ANISOTROPY; CHERENKOV COUNTERS...

    Office of Scientific and Technical Information (OSTI)

    National Laboratory 71; ANISOTROPY; CHERENKOV COUNTERS; COSMIC RADIATION; EMISSION; ENERGY; MODULATION; PHYSICS; TIME DEPENDENCE; WATER The Milagro gamma-ray observatory is a...

  16. Layering and temperature-dependent magnetization and anisotropy of naturally produced Ni/NiO multilayers

    SciTech Connect (OSTI)

    Pappas, S. D.; Trachylis, D.; Velgakis, M. J.; Kapaklis, V.; Joensson, P. E.; Papaioannou, E. Th.; Delimitis, A.; Poulopoulos, P.; Fumagalli, P.; Politis, C.

    2012-09-01

    Ni/NiO multilayers were grown by magnetron sputtering at room temperature, with the aid of the natural oxidation procedure. That is, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer ({approx}1.2 nm) is formed. Simulated x-ray reflectivity patterns reveal that layering is excellent for individual Ni-layer thickness larger than 2.5 nm, which is attributed to the intercalation of amorphous NiO between the polycrystalline Ni layers. The magnetization of the films, measured at temperatures 5-300 K, has almost bulk-like value, whereas the films exhibit a trend to perpendicular magnetic anisotropy (PMA) with an unusual significant positive interface anisotropy contribution, which presents a weak temperature dependence. The power-law behavior of the multilayers indicates a non-negligible contribution of higher order anisotropies in the uniaxial anisotropy. Bloch-law fittings for the temperature dependence of the magnetization in the spin-wave regime show that the magnetization in the multilayers decreases faster as a function of temperature than the one of bulk Ni. Finally, when the individual Ni-layer thickness decreases below 2 nm, the multilayer stacking vanishes, resulting in a dramatic decrease of the interface magnetic anisotropy and consequently in a decrease of the perpendicular magnetic anisotropy.

  17. CONSTRAINTS ON SUBDUCTION GEODYNAMICS FROM SEISMIC ANISOTROPY

    E-Print Network [OSTI]

    on the characterization and interpretation of seismic anisotropy can lead to progress, particularly in frontier areasCONSTRAINTS ON SUBDUCTION GEODYNAMICS FROM SEISMIC ANISOTROPY Maureen D. Long1 Received 4 October, and the interactions between slabs and deep discontinuities such as the core-mantle boundary. Observations of seismic

  18. Direct Measurement of Chemical Shielding Anisotropies. Fluoranil

    E-Print Network [OSTI]

    Griffin, Robert G.

    7222 Direct Measurement of Chemical Shielding Anisotropies. Fluoranil Sir: Although the nuclear magnetic shielding coefficient d is a tensor quantity, nearly all measurements of it have been confined to the mean shielding u = Tr(d), since all spectral information about its anisotropy is erased by rapid

  19. Seismic anisotropy changes across upper mantle phase transitions

    E-Print Network [OSTI]

    Yuan, K; Beghein, C

    2013-01-01

    P. , 2000. Upper mantle seismic discontinuities. In: Karato,2005. Global azimuthal seismic anisotropy and the unique2255–2258. Karato, S. , 1998. Seismic anisotropy in the deep

  20. Primordial anisotropies in gauged hybrid inflation

    SciTech Connect (OSTI)

    Abolhasani, Ali Akbar; Emami, Razieh; Firouzjahi, Hassan E-mail: emami@ipm.ir

    2014-05-01

    We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a U(1)gauge field. Primordial anisotropies are generated either actively during inflation or from inhomogeneities modulating the surface of end of inflation during waterfall transition. We present a consistent ?N mechanism to calculate the anisotropic power spectrum and bispectrum. We show that the primordial anisotropies generated at the surface of end of inflation do not depend on the number of e-folds and therefore do not produce dangerously large anisotropies associated with the IR modes. Furthermore, one can find the parameter space that the anisotropies generated from the surface of end of inflation cancel the anisotropies generated during inflation, therefore relaxing the constrains on model parameters imposed from IR anisotropies. We also show that the gauge field fluctuations induce a red-tilted power spectrum so the averaged power spectrum from the gauge field can change the total power spectrum from blue to red. Therefore, hybrid inflation, once gauged under a U(1) field, can be consistent with the cosmological observations.

  1. acoustic anisotropy vs. depth, A:162, 306

    E-Print Network [OSTI]

    /aluminum ratio; thorium/aluminum ratio; titanium/aluminum ratio; uranium/alu- minum ratio; vanadium acoustic anisotropy anoxic environment deposition, A:260, 262 lithologic units, A:59, 116­118 synthesis, A

  2. High anisotropy materials for magnetic nanotechnologies

    E-Print Network [OSTI]

    Shipton, Erik G.

    2011-01-01

    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

  3. Wind anisotropy and stellar evolution

    E-Print Network [OSTI]

    Cyril Georgy; Georges Meynet; André Maeder

    2008-07-31

    Mass loss is a determinant factor which strongly affects the evolution and the fate of massive stars. At low metallicity, stars are supposed to rotate faster than at the solar one. This favors the existence of stars near the critical velocity. In this rotation regime, the deformation of the stellar surface becomes important, and wind anisotropy develops. Polar winds are expected to be dominant for fast rotating hot stars. These polar winds allow the star to lose large quantities of mass and still retain a high angular momentum, and they modifie the evolution of the surface velocity and the final angular momentum kept in the star's core. We show here how these winds affect the final stages of massive stars, according to our knowledge about Gamma Ray Bursts. Computation of theoretical Gamma Ray Bursts rate indicates that our models have too fast rotating cores, and that we need to include an additional effect to spin them down. Magnetic fields in stars act in this direction, and we show how they modify the evolution of massive star up to the final stages.

  4. Predicting stress-induced velocity anisotropy in rocks

    SciTech Connect (OSTI)

    Mavko, G.; Mukerji, T.; Godfrey, N. [Stanford Univ., CA (United States). Rock Physics Lab.] [Stanford Univ., CA (United States). Rock Physics Lab.

    1995-07-01

    A simple transformation, using measured isotropic V{sub P} and V{sub S} versus hydrostatic pressure, is presented for predicting stress-induced seismic velocity anisotropy in rocks. The compliant, crack-like portions of the pore space are characterized by generalized compressional and shear compliances that are estimated form the isotropic V{sub P} and V{sub S}. The physical assumption that the compliant porosity is crack-like means that the pressure dependence of the generalized compliances is governed primarily by normal tractions resolved across cracks and defects. This allows the measured pressure dependence to be mapped form the hydrostatic stress state to any applied nonhydrostatic stress. Predicted P- and S-wave velocities agree reasonably well with uniaxial stress data for Barre Granite and Massillon Sandstone. While it is mechanically similar to methods based on idealized ellipsoidal cracks, the approach is relatively independent of any assumed crack geometry and is not limited to small crack densities.

  5. Cosmic ray transport and anisotropies to high energies

    E-Print Network [OSTI]

    Biermann, P L; Meli, A; Nath, B N; Seo, E -S; de Souza, V; Tjus, J Becker

    2015-01-01

    A model is introduced, in which the irregularity spectrum of the Galactic magnetic field beyond the dissipation length scale is first a Kolmogorov spectrum $k^{-5/3}$ at small scales $\\lambda \\, = \\, 2 \\pi/k$ with $k$ the wave-number, then a saturation spectrum $k^{-1}$, and finally a shock-dominated spectrum $k^{-2}$ mostly in the halo/wind outside the Cosmic Ray disk. In an isotropic approximation such a model is consistent with the Interstellar Medium (ISM) data. With this model we discuss the Galactic Cosmic Ray (GCR) spectrum, as well as the extragalactic Ultra High Energy Cosmic Rays (UHECRs), their chemical abundances and anisotropies. UHECRs may include a proton component from many radio galaxies integrated over vast distances, visible already below 3 EeV.

  6. The expected anisotropy in solid inflation

    SciTech Connect (OSTI)

    Bartolo, Nicola; Ricciardone, Angelo; Peloso, Marco; Unal, Caner E-mail: peloso@physics.umn.edu E-mail: unal@physics.umn.edu

    2014-11-01

    Solid inflation is an effective field theory of inflation in which isotropy and homogeneity are accomplished via a specific combination of anisotropic sources (three scalar fields that individually break isotropy). This results in specific observational signatures that are not found in standard models of inflation: a non-trivial angular dependence for the squeezed bispectrum, and a possibly long period of anisotropic inflation (to drive inflation, the ''solid'' must be very insensitive to any deformation, and thus background anisotropies are very slowly erased). In this paper we compute the expected level of statistical anisotropy in the power spectrum of the curvature perturbations of this model. To do so, we account for the classical background values of the three scalar fields that are generated on large (superhorizon) scales during inflation via a random walk sum, as the perturbation modes leave the horizon. Such an anisotropy is unavoidably generated, even starting from perfectly isotropic classical initial conditions. The expected level of anisotropy is related to the duration of inflation and to the amplitude of the squeezed bispectrum. If this amplitude is close to its current observational limit (so that one of the most interesting predictions of the model can be observed in the near future), we find that a level of statistical anisotropy F{sup 2} gives frozen and scale invariant vector perturbations on superhorizon scales.

  7. Determination of Near-Surface Anisotropy From Surface Electromagnetic Data

    E-Print Network [OSTI]

    Al-Dajani, AbdulFattah

    2001-01-01

    Ground penetrating radar (GPR) signatures, such as reflection moveout, are sensitive to the presence of azimuthal anisotropy. Azimuthal anisotropy can occur as an intrinsic property of the medium and/or due to the presence ...

  8. Advanced MHD models of anisotropy, flow and chaotic fields

    E-Print Network [OSTI]

    Hudson, Stuart

    Advanced MHD models of anisotropy, flow and chaotic fields M. J. Hole1, M. Fitzgerald1, G. Dennis1, pressure" #12;Expected impact of anisotropy · If p > p||, an increase will occur in centrifugal shift : [R

  9. Temperature Anisotropies in a Universe with Global Defects

    E-Print Network [OSTI]

    David Coulson

    1994-07-15

    We present a technique of calculating microwave anisotropies from global defects in a reionised universe. We concentrate on angular scales down to one degree where we expect the nongaussianity of the temperature anisotropy in these models to become apparent.

  10. Numerical likelihood analysis of cosmic ray anisotropies

    SciTech Connect (OSTI)

    Carlos Hojvat et al.

    2003-07-02

    A numerical likelihood approach to the determination of cosmic ray anisotropies is presented which offers many advantages over other approaches. It allows a wide range of statistically meaningful hypotheses to be compared even when full sky coverage is unavailable, can be readily extended in order to include measurement errors, and makes maximum unbiased use of all available information.

  11. Kirchhoff prestack depth migration in simple models of various anisotropy

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    Kirchhoff prestack depth migration in simple models of various anisotropy V´aclav Bucha Department Republic, E-mail: bucha@seis.karlov.mff.cuni.cz Summary We apply the Kirchhoff prestack depth migration anisotropy and monoclinic anisotropy. We test Kirchhoff prestack depth migration in two ways: a

  12. The expected anisotropy in solid inflation

    E-Print Network [OSTI]

    Nicola Bartolo; Marco Peloso; Angelo Ricciardone; Caner Unal

    2014-07-30

    Solid inflation is an effective field theory of inflation in which isotropy and homogeneity are accomplished via a specific combination of anisotropic sources (three scalar fields that individually break isotropy). This results in specific observational signatures that are not found in standard models of inflation: a non-trivial angular dependence for the squeezed bispectrum, and a possibly long period of anisotropic inflation (to drive inflation, the "solid" must be very insensitive to any deformation, and thus background anisotropies are very slowly erased). In this paper we compute the expected level of statistical anisotropy in the power spectrum of the curvature perturbations of this model. To do so, we account for the classical background values of the three scalar fields that are generated on large (superhorizon) scales during inflation via a random walk sum, as the perturbation modes leave the horizon. Such an anisotropy is unavoidably generated, even starting from perfectly isotropic classical initial conditions. The expected level of anisotropy is related to the duration of inflation and to the amplitude of the squeezed bispectrum. If this amplitude is close to its current observational limit (so that one of the most interesting predictions of the model can be observed in the near future), we find that a level of statistical anisotropy $\\gtrsim 3\\%$ in the power spectrum is to be expected, if inflation lasted $\\gtrsim 20-30$ e-folds more than the final $50-60$ efolds required to generare the CMB modes. We also comment and point out various similarities between solid inflation and models of inflation where a suitable coupling of the inflaton to a vector kinetic term $F^{2}$ gives frozen and scale invariant vector perturbations on superhorizon scales.

  13. 2011 Waves -1 STANDING WAVES

    E-Print Network [OSTI]

    Gustafsson, Torgny

    2011 Waves - 1 STANDING WAVES ON A STRING The objectives of the experiment are: · To show that standing waves can be set up on a string. · To determine the velocity of a standing wave. · To understand of waves. A #12;2011 Waves - 2 A standing wave is caused by superposing two similar (same frequency

  14. I-Love-Q anisotropically: Universal relations for compact stars with scalar pressure anisotropy

    E-Print Network [OSTI]

    Kent Yagi; Nicolas Yunes

    2015-07-08

    Certain physical quantities that characterize neutron stars and quark stars (e.g. their mass, spin angular momentum and quadrupole moment) are interrelated in a way that is approximately insensitive to their internal structure. Such approximately universal relations are useful to break degeneracies in data analysis for future radio, X-ray and gravitational wave observations. Although the pressure inside compact stars is most likely nearly isotropic, certain scenarios have been put forth that suggest otherwise, for example due to phase transitions. We here investigate whether pressure anisotropy affects the approximate universal relations and whether it prevents their use in future observations. We achieve this by numerically constructing slowly-rotating and tidally-deformed, anisotropic, compact stars in General Relativity to third order in spin. We find that anisotropy affects the universal relations only weakly; the relations become less universal by a factor of 1.5-3 relative to the isotropic case, but remain approximately universal to 10%. We succeed in explaining this increase in variability as an increase in the eccentricity variation of isodensity contours, which provides further support for the emergent approximate symmetry explanation of universality. Anisotropy does not affect the universal relations to a sufficient level to prevent their use in gravitational wave astrophysics or in experimental relativity. We provide an explicit example of the latter in dynamical Chern-Simons gravity. The increase in variability of the universal relations due to pressure anisotropy could affect their use in future X-ray observations. Given expected observational uncertainties, however, the relations remain sufficiently universal for use in such observations if the anisotropic modifications to the moment of inertia and the quadrupole moment are less than 10% of their isotropic values.

  15. Weibel instability for a streaming electron, counterstreaming e-e, and e-p plasmas with intrinsic temperature anisotropy

    SciTech Connect (OSTI)

    Ghorbanalilu, M.; Physics Department, Azarbaijan Shahid Madani University, Tabriz ; Sadegzadeh, S.; Ghaderi, Z.; Niknam, A. R.

    2014-05-15

    The existence of Weibel instability for a streaming electron, counterstreaming electron-electron (e-e), and electron-positron (e-p) plasmas with intrinsic temperature anisotropy is investigated. The temperature anisotropy is included in the directions perpendicular and parallel to the streaming direction. It is shown that the beam mean speed changes the instability mode, for a streaming electron beam, from the classic Weibel to the Weibel-like mode. The analytical and numerical solutions approved that Weibel-like modes are excited for both counterstreaming e-e and e-p plasmas. The growth rates of the instabilities in e-e and e-p plasmas are compared. The growth rate is larger for e-p plasmas if the thermal anisotropy is small and the opposite is true for large thermal anisotropies. The analytical and numerical solutions are in good agreement only in the small parallel temperature and wave number limits, when the instability growth rate increases linearly with normalized wave number kc??{sub p}.

  16. LIMITS ON ALPHA PARTICLE TEMPERATURE ANISOTROPY AND DIFFERENTIAL FLOW FROM KINETIC INSTABILITIES: SOLAR WIND OBSERVATIONS

    SciTech Connect (OSTI)

    Bourouaine, Sofiane; Verscharen, Daniel; Chandran, Benjamin D. G.; Maruca, Bennett A.; Kasper, Justin C.

    2013-11-01

    Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure and anisotropy driven instabilities such as the Alfvén/ion-cyclotron (A/IC) and fast-magnetosonic/whistler (FM/W) instabilities. In this Letter, we use a long period of in situ measurements provided by the Wind spacecraft's Faraday cups to investigate the combined constraint on the alpha proton differential flow velocity and the alpha particle temperature anisotropy due to A/IC and FM/W instabilities. We show that the majority of the data are constrained to lie within the region of parameter space in which A/IC and FM/W waves are either stable or have extremely low growth rates. In the minority of observed cases in which the growth rate of the A/IC (FM/W) instability is comparatively large, we find relatively higher values of T {sub ?}/T {sub p} (T {sub ??}/T {sub ?p}) when the alpha proton differential flow velocity is small, where T {sub ?} and T {sub p} (T {sub ??} and T {sub ?p}) are the perpendicular (parallel) temperatures of alpha particles and protons. We conjecture that this observed feature might arise from preferential alpha particle heating which can drive the alpha particles beyond the instability thresholds.

  17. The Anisotropy of the Extragalactic Radio Background from Dark Matter Annihilation

    E-Print Network [OSTI]

    Ke Fang; Tim Linden

    2014-12-23

    Observations of the extragalactic radio background have uncovered a significant isotropic emission across multiple frequencies spanning from 22 MHz to 10 GHz. The intensity of this non-thermal emission component significantly exceeds the expected contribution from known astrophysical sources. Interestingly, models have indicated that the annihilation of dark matter particles may reproduce both the flux and spectrum of the excess. However, the lack of a measurable anisotropy in the residual emission remains challenging for both dark matter and standard astrophysical interpretations of the ARCADE-2 data. We calculate the expected synchrotron anisotropy from dark matter annihilation and show that these models can produce very small anisotropies, though this requires galaxy clusters to have large substructure contributions and strong magnetic fields. We show that this constraint can be significantly relaxed, however, in scenarios where electrons produced via dark matter annihilation can be efficiently reaccelerated by Alfv\\'en waves in the intra-Cluster medium. Our analysis indicates that any source capable of explaining the intensity and isotropy of the extragalactic radio excess must have a spatial extension far larger than typical for baryons in galaxies, suggesting a novel physics interpretation.

  18. Generation of Gravitational Waves and Scalar Perturbations in Inflation with Effective $?$-term and T/S Story

    E-Print Network [OSTI]

    V. N. Lukash; E. V. Mikheeva

    1998-03-06

    We argue that gravitational wave contribution to the cosmic microwave background anisotropy at angular scale $\\sim 10^0$ may exceed 50% for some models of hybrid inflation producing standard cosmology with the density perturbation slope $n \\simeq 1$.

  19. Azimuthal anisotropy distributions in high-energy collisions...

    Office of Scientific and Technical Information (OSTI)

    Search Title: Azimuthal anisotropy distributions in high-energy collisions Elliptic flow in ultrarelativistic heavy-ion collisions results from the hydrodynamic response to the...

  20. Concave nanomagnets with widely tunable anisotropy

    DOE Patents [OSTI]

    Lambson, Brian; Gu, Zheng; Carlton, David; Bokor, Jeffrey

    2014-07-01

    A nanomagnet having widely tunable anisotropy is disclosed. The disclosed nanomagnet is a magnetic particle with a convex shape having a first magnetically easy axis. The convex shape is modified to include at least one concavity to urge a second magnetically easy axis to form substantially offset from the first magnetically easy axis. In at least one embodiment, the convex shape is also modified to include at least one concavity to urge a second magnetically easy axis to form with a magnetic strength substantially different from the first magnetically easy axis.

  1. Molecular anisotropy effects in carbon K-edge scattering: depolarized diffuse scattering and optical anisotropy

    SciTech Connect (OSTI)

    Stone, Kevin H.

    2014-07-14

    Some polymer properties, such as conductivity, are very sensitive to short- and intermediate-range orientational and positional ordering of anisotropic molecular functional groups, and yet means to characterize orientational order in disordered systems are very limited. We demonstrate that resonant scattering at the carbon K-edge is uniquely sensitive to short-range orientation correlations in polymers through depolarized scattering at high momentum transfers, using atactic polystyrene as a well-characterized test system. Depolarized scattering is found to coexist with unpolarized fluorescence, and to exhibit pronounced anisotropy. We also quantify the spatially averaged optical anisotropy from low-angle reflectivity measurements, finding anisotropy consistent with prior visible, x-ray absorption, and theoretical studies. The average anisotropy is much smaller than that in the depolarized scattering and the two have different character. Both measurements exhibit clear spectral signatures from the phenyl rings and the polyethylene-like backbone. Discussion focuses on analysis considerations and prospects for using this depolarized scattering for studies of disorder in soft condensed matter.

  2. Experiments to Separate the Effect of Texture on Anisotropy of Pipeline Steel

    E-Print Network [OSTI]

    Cambridge, University of

    Experiments to Separate the Effect of Texture on Anisotropy of Pipeline Steel M. S. Jooa , D the anisotropy of Charpy test energy. Keywords: pipeline steel, anisotropy, crystallographic texture, memory

  3. Wave Motion

    E-Print Network [OSTI]

    M. Carcione, F. Cavallini, Simulation of waves in porn-viscoelastic rocks Saturated by immiscible ?uids. Numerical evidence ofa second slow wave,]. Comput.

  4. Anisotropy of strong pinning in multi-band superconductors

    E-Print Network [OSTI]

    Boyer, Edmond

    pinning in multi-band superconductors 2 1. Introduction The multi-band nature of superconductivity in iron the anisotropy of superconducting parameters in the iron-based superconductors. In particular, Kidzun et al. [23Anisotropy of strong pinning in multi-band superconductors C.J. van der Beek, M. Konczykowski

  5. SUBMITTED TO GRL 1 Thermal Anisotropies in the Solar Wind

    E-Print Network [OSTI]

    Richardson, John

    SUBMITTED TO GRL 1 E Thermal Anisotropies in the Solar Wind: vidence of Heating by Interstellar cyclotron instabilit s generated by newly created pickup ions and heats the thermal solar wind protons TO GRL 2 T Introduction he thermal anisotropy of the solar wind is the ratio between the temperatures p

  6. Relationship between Anisotropy in Soil Hydraulic Conductivity and Saturation

    SciTech Connect (OSTI)

    Zhang, Z. Fred

    2014-01-01

    Anisotropy in unsaturated hydraulic conductivity is saturation-dependent. Accurate characterization of soil anisotropy is very important in simulating flow and contaminant (e.g., radioactive nuclides in Hanford) transport. A recently developed tensorial connectivity-tortuosity (TCT) concept describes the hydraulic conductivity tensor of the unsaturated anisotropic soils as the product of a scalar variable, the symmetric connectivity tortuosity tensor, and the hydraulic conductivity tensor at saturation. In this study, the TCT model is used to quantify soil anisotropy in unsaturated hydraulic conductivity. The TCT model can describe different types of soil anisotropy; e.g., the anisotropy coefficient, C, can be monotonically increase or decrease with saturation and can vary from greater than unity to less than unity and vice versa. Soil anisotropy is independent of soil water retention properties and can be characterized by the ratio of the saturated hydraulic conductivities and the difference of the tortuosity-connectivity coefficients in two directions. ln(C) is linearly proportional to ln(Se) with Se being the effective saturation. The log-linear relationship between C and Se allows the saturation-dependent anisotropy to be determined using linear regression with the measurements of the directional hydraulic conductivities at a minimum of two water content levels, of which one may be at full saturation. The model was tested using measurements of directional hydraulic conductivities.

  7. Anisotropy of magnetic emulsions induced by magnetic and electric fields

    E-Print Network [OSTI]

    Yury I. Dikansky; Alexander N. Tyatyushkin; Arthur R. Zakinyan

    2011-09-10

    The anisotropy of magnetic emulsions induced by simultaneously acting electric and magnetic fields is theoretically and experimentally investigated. Due to the anisotropy, the electric conductivity and magnetic permeability of a magnetic emulsion are no longer scalar coefficients, but are tensors. The electric conductivity and magnetic permeability tensors of sufficiently diluted emulsions in sufficiently weak electric and magnetic fields are found as functions of the electric and magnetic intensity vectors. The theoretically predicted induced anisotropy was verified experimentally. The experimental data are analyzed and compared with theoretical predictions. The results of the analysis and comparison are discussed.

  8. Engineering functional anisotropy in fibrocartilage neotissues Regina F. MacBarb a

    E-Print Network [OSTI]

    Athanasiou, Kyriacos

    ]. With regards to matrix anisotropy, electrospinning has been used to align either organic or inorganic fibers

  9. Current sheets and pressure anisotropy in the reconnection exhaust

    SciTech Connect (OSTI)

    Le, A.; Karimabadi, H.; Roytershteyn, V. [SciberQuest, Inc., Del Mar, California 92014 (United States)] [SciberQuest, Inc., Del Mar, California 92014 (United States); Egedal, J. [University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States)] [University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States); Ng, J. [PPPL, Princeton University, Princeton, New Jersey 08543 (United States)] [PPPL, Princeton University, Princeton, New Jersey 08543 (United States); Scudder, J. [University of Iowa, Iowa City, Iowa 52242 (United States)] [University of Iowa, Iowa City, Iowa 52242 (United States); Daughton, W.; Liu, Y.-H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-01-15

    A particle-in-cell simulation shows that the exhaust during anti-parallel reconnection in the collisionless regime contains a current sheet extending 100 inertial lengths from the X line. The current sheet is supported by electron pressure anisotropy near the X line and ion anisotropy farther downstream. Field-aligned electron currents flowing outside the magnetic separatrices feed the exhaust current sheet and generate the out-of-plane, or Hall, magnetic field. Existing models based on different mechanisms for each particle species provide good estimates for the levels of pressure anisotropy. The ion anisotropy, which is strong enough to reach the firehose instability threshold, is also important for overall force balance. It reduces the outflow speed of the plasma.

  10. On the drift magnetosonic waves in anisotropic low beta plasmas

    SciTech Connect (OSTI)

    Naim, Hafsa, E-mail: roohi-phy@yahoo.com [Department of Physics, G. C. University Lahore, Katchery Road, Lahore 54000 (Pakistan); Bashir, M. F., E-mail: frazbashir@yahoo.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Murtaza, G. [Visiting Professor, Department of Physics, Quaid-e-Azam University, Islamabad (Pakistan)

    2014-10-15

    A generalized dispersion relation of obliquely propagating drift magnetosonic waves is derived by using the gyrokinetic theory for anisotropic low beta plasmas. The stability analysis applicable to a wide range of plasma parameters is performed to understand the stabilization mechanism of the drift magnetosonic instability and the estimation of the growth rate is also presented. It is noted that the growth rate of the drift instability enhances for small anisotropy (A{sub e,i}?=?T{sub ?e,i}/T{sub ?e,i}?anisotropy (A{sub e,i}?>?1)

  11. Excitation of Banded Whistler Waves in the Magnetosphere

    SciTech Connect (OSTI)

    Gary, S. Peter; Liu, Kaijun; Winske, Dan

    2012-07-13

    Banded whistler waves can be generated by the whistler anisotropy instability driven by two bi-Maxwellian electron components with T{sub {perpendicular}}/T{sub {parallel}} > 1 at different T{sub {parallel}} For typical magnetospheric condition of 1 < {omega}{sub e}/{Omega}{sub e} < 5 in regions associated with strong chorus, upper-band waves can be excited by anisotropic electrons below {approx} 1 keV, while lower-band waves are excited by anisotropic electrons above {approx} 10 keV. Lower-band waves are generally field-aligned and substantially electromagnetic, while upper-band waves propagate obliquely and have quasi-electrostatic fluctuating electric fields. The quasi-electrostatic feature of upper-band waves suggests that they may be more easily identified in electric field observations than in magnetic field observations. Upper-band waves are liable to Landau damping and the saturation level of upperband waves is lower than lower-band waves, consistent with observations that lower-band waves are stronger than upper-band waves on average. The oblique propagation, the lower saturation level, and the more severe Landau damping together would make upper-band waves more tightly confined to the geomagnetic equator (|{lambda}{sub m}| < {approx}10{sup o}) than lower-band waves.

  12. Wave represents displacement Wave represents pressure Source -Sound Waves

    E-Print Network [OSTI]

    Colorado at Boulder, University of

    is wavelength Number of crests passing a point in 1 second is frequency Wave represents pressure Target - Radio. The Sound Waves simulation becomes the source of an analogical mapping to Radio Waves. Concepts Radio Waves 1 - Sound Waves references water waves 2 - Water is analogy for Sound Waves 3 - Radio

  13. The enigma of post-perovskite anisotropy: deformation versus transformation textures

    SciTech Connect (OSTI)

    Miyagi, Lowell; Kanitpanyacharoen, Waruntorn; Stackhouse, Stephen; Militzer, Burkhard; Wenk, Hans-Rudolf

    2012-01-20

    The D'' region that lies just above the core mantle boundary exhibits complex anisotropy that this is likely due to preferred orientation (texturing) of the constituent minerals. (Mg,Fe)SiO{sub 3} post-perovskite is widely thought to be the major mineral phase of the D''. Texture development has been studied in various post-perovskite phases (MgSiO{sub 3}, MgGeO{sub 3}, and CaIrO{sub 3}), and different results were obtained. To clarify this controversy, we report on transformation and deformation textures in MgGeO{sub 3} post-perovskite synthesized and deformed at room temperature in the diamond anvil cell. Transformed from the enstatite phase, MgGeO{sub 3} post-perovskite exhibits a transformation texture characterized by (100) planes at high angles to the direction of compression. Upon subsequent deformation, this texture changes and (001) lattice planes become oriented nearly perpendicular to compression, consistent with dominant (001)[100] slip. When MgGeO{sub 3} post-perovskite is synthesized from the perovskite phase, a different transformation texture is observed. This texture has (001) planes at high angle to compression and becomes slightly stronger upon compression. We also find that the yield strength of MgGeO{sub 3} post-perovskite is dependent on grain size and texture. Finer-grained samples exhibit higher yield strength and are harder to induce plastic deformation. Strong textures also affect the yield strength and can result in higher differential stresses. The inferred dominant (001) slip for pPv is significant for geophysics, because, when applied to geodynamic convection models, it predicts the observed anisotropies of S-waves as well as an anti-correlation between P- and S-waves.

  14. Predicted Impacts of Proton Temperature Anisotropy on Solar Wind Turbulence

    E-Print Network [OSTI]

    Klein, Kristopher G

    2015-01-01

    Particle velocity distributions measured in the weakly collisional solar wind are frequently found to be non-Maxwellian, but how these non-Maxwellian distributions impact the physics of plasma turbulence in the solar wind remains unanswered. Using numerical solutions of the linear dispersion relation for a collisionless plasma with a bi-Maxwellian proton velocity distribution, we present a unified framework for the four proton temperature anisotropy instabilities, identifying the associated stable eigenmodes, highlighting the unstable region of wavevector space, and presenting the properties of the growing eigenfunctions. Based on physical intuition gained from this framework, we address how the proton temperature anisotropy impacts the nonlinear dynamics of the \\Alfvenic fluctuations underlying the dominant cascade of energy from large to small scales and how the fluctuations driven by proton temperature anisotropy instabilities interact nonlinearly with each other and with the fluctuations of the large-scal...

  15. Vacuum Waves

    E-Print Network [OSTI]

    Paul S. Wesson

    2012-12-11

    As an example of the unification of gravitation and particle physics, an exact solution of the five-dimensional field equations is studied which describes waves in the classical Einstein vacuum. While the solution is essentially 5D in nature, the waves exist in ordinary 3D space, and may provide a way to test for an extra dimension.

  16. The origin of photochemical anisotropy in SrTiO3 Jennifer L. Giocondia,b

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    products on catalytic surfaces have been used to probe the anisotropy of the reactivity of SrTiO3 proximity, then the reverse reaction to reform water is likely. Photochemical anisotropies are studied using

  17. Analysis of seismic anisotropy in 3D multi-component seismic data 

    E-Print Network [OSTI]

    Qian, Zhongping

    2010-01-01

    The importance of seismic anisotropy has been recognized by the oil industry since its first observation in hydrocarbon reservoirs in 1986, and the application of seismic anisotropy to solve geophysical problems has been ...

  18. Anisotropy analysis of EAS data in the knee region

    E-Print Network [OSTI]

    S. V. Ter-Antonyan

    2001-06-07

    Based on MAKET-ANI EAS data the distributions of equatorial coordinates of EAS core directions are obtained in the knee region. Anisotropy of primary cosmic rays is displayed only by declination equatorial coordinates (20+/-3 degrees) at primary energies more than 5-10 PeV. The fraction of anisotropic component turns out ~10% in the knee region.

  19. ANNIVERSARY REVIEW Grain boundary energy anisotropy: a review

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    energy (B) gained when the two surfaces are brought together and new bonds are formed. The grain boundary with the stiffness of the material. The excess energy of the grANNIVERSARY REVIEW Grain boundary energy anisotropy: a review Gregory S. Rohrer Received: 29 April

  20. Resolution of reservoir scale electrical anisotropy from marine CSEM data

    SciTech Connect (OSTI)

    Brown, V.; Hoversten, G.M.; Key, K.; Chen, J.

    2011-10-01

    A combination of 1D and 3D forward and inverse solutions is used to quantify the sensitivity and resolution of conventional controlled source electromagnetic (CSEM) data collected using a horizontal electric dipole source to transverse electrical anisotropy located in a deep-water exploration reservoir target. Since strongly anisotropic shale layers have a vertical resistivity that can be comparable to many reservoirs, we examine how CSEM can discriminate confounding shale layers through their characteristically lower horizontal resistivity. Forward modeling demonstrates that the sensitivity to reservoir level anisotropy is very low compared to the sensitivity to isotropic reservoirs, especially when the reservoir is deeper than about 2 km below the seabed. However, for 1D models where the number of inversion parameters can be fixed to be only a few layers, both vertical and horizontal resistivity of the reservoir can be well resolved using a stochastic inversion. We find that the resolution of horizontal resistivity increases as the horizontal resistivity decreases. We show that this effect is explained by the presence of strong horizontal current density in anisotropic layers with low horizontal resistivity. Conversely, when the reservoir has a vertical to horizontal resistivity ratio of about 10 or less, the current density is vertically polarized and hence has little sensitivity to the horizontal resistivity. Resistivity anisotropy estimates from 3D inversion for 3D targets suggest that resolution of reservoir level anisotropy for 3D targets will require good a priori knowledge of the background sediment conductivity and structural boundaries.

  1. Seismic anisotropy in exploration and reservoir characterization: An overview

    E-Print Network [OSTI]

    Tsvankin, Ilya

    range of seismic methods. In particular, vertical and tilted transverse isotropy are currently treated vertical-seis- mic-profiling VSP surveys, moveout inversion of wide-azi- muth data, amplitudeSeismic anisotropy in exploration and reservoir characterization: An overview Ilya Tsvankin1

  2. Seismic waves in rocks with fluids and fractures

    SciTech Connect (OSTI)

    Berryman, J.G.

    2007-05-14

    Seismic wave propagation through the earth is often stronglyaffected by the presence of fractures. When these fractures are filledwith fluids (oil, gas, water, CO2, etc.), the type and state of the fluid(liquid or gas) can make a large difference in the response of theseismic waves. This paper summarizes recent work on methods ofdeconstructing the effects of fractures, and any fluids within thesefractures, on seismic wave propagation as observed in reflection seismicdata. One method explored here is Thomsen's weak anisotropy approximationfor wave moveout (since fractures often induce elastic anisotropy due tononuniform crack-orientation statistics). Another method makes use ofsome very convenient fracture parameters introduced previously thatpermit a relatively simple deconstruction of the elastic and wavepropagation behavior in terms of a small number of fracture parameters(whenever this is appropriate, as is certainly the case for small crackdensities). Then, the quantitative effects of fluids on thesecrack-influence parameters are shown to be directly related to Skempton scoefficient B of undrained poroelasticity (where B typically ranges from0 to 1). In particular, the rigorous result obtained for the low crackdensity limit is that the crack-influence parameters are multiplied by afactor (1 ? B) for undrained systems. It is also shown how fractureanisotropy affects Rayleigh wave speed, and how measured Rayleigh wavespeeds can be used to infer shear wave speed of the fractured medium.Higher crack density results are also presented by incorporating recentsimulation data on such cracked systems.

  3. Interpretation of seismic anisotropy in terms of mantle flow when melt is present

    E-Print Network [OSTI]

    Kaminski, Edouard

    Interpretation of seismic anisotropy in terms of mantle flow when melt is present E. Kaminski scale. Citation: Kaminski, E. (2006), Interpretation of seismic anisotropy in terms of mantle flow when of seismic anisotropy to image upper mantle flow is usually based on the assumption that the direction

  4. MAGNETIC ANISOTROPY AS AN AID TO IDENTIFYING CRM AND DRM IN RED SEDIMENTARY ROCKS

    E-Print Network [OSTI]

    Utrecht, Universiteit

    the remanence anisotropy of hematite-bearing sedimentary rocks. It also shows that very high magnetic fieldsMAGNETIC ANISOTROPY AS AN AID TO IDENTIFYING CRM AND DRM IN RED SEDIMENTARY ROCKS K.P. KODAMA1 June, 2004; Accepted: August 25, 2004 ABSTRACT To further evaluate the potential of magnetic anisotropy

  5. Effects of Hall current and electron temperature anisotropy on proton fire-hose instabilities

    SciTech Connect (OSTI)

    Hau, L.-N. [Institute of Space Science, National Central University, Jhongli, Taiwan (China) [Institute of Space Science, National Central University, Jhongli, Taiwan (China); Department of Physics, National Central University, Jhongli, Taiwan (China); Wang, B.-J. [Institute of Space Science, National Central University, Jhongli, Taiwan (China) [Institute of Space Science, National Central University, Jhongli, Taiwan (China); Institute of Astronomy, National Central University, Jhongli, Taiwan (China)

    2013-10-15

    The standard magnetohydrodynamic (MHD) theory predicts that the Alfvén wave may become fire-hose unstable for ?{sub ?}??{sub ?}>2. In this study, we examine the proton fire-hose instability (FHI) based on the gyrotropic two-fluid model, which incorporates the ion inertial effects arising from the Hall current and electron temperature anisotropy but neglects the electron inertia in the generalized Ohm's law. The linear dispersion relation is derived and analyzed which in the long wavelength approximation, ?{sub i}k?0 or ?{sub e}=?{sub 0}(p{sub ?,e}?p{sub ?,e})/B{sup 2}=1, recovers the ideal MHD model with separate temperature for ions and electrons. Here, ?{sub i} is the ion inertial length and k is the wave number. For parallel propagation, both ion cyclotron and whistler waves become propagating and growing for ?{sub ?}??{sub ?}>2+?{sub i}{sup 2}k{sup 2}(?{sub e}?1){sup 2}/2. For oblique propagation, the necessary condition for FHI remains to be ?{sub ?}??{sub ?}>2 and there exist one or two unstable fire-hose modes, which can be propagating and growing or purely growing. For large ?{sub i}k values, there exists no nearly parallel FHI leaving only oblique FHI and the effect of ?{sub e}>1 may greatly enhance the growth rate of parallel and oblique FHI. The magnetic field polarization of FHI may be reversed due to the sign change associated with (?{sub e}?1) and the purely growing FHI may possess linear polarization while the propagating and growing FHI may possess right-handed or left-handed polarization.

  6. Wave Propagation in Multiferroic Materials

    E-Print Network [OSTI]

    Keller, Scott Macklin

    2013-01-01

    130 SAW Waves . . . . . . . . . . . . . .QuasiStatic MEE Waves . . . . . . . . . . . . . . . . . . .General MEE Wave Solution . . . . . . . . . . . .

  7. Internal wave instability: Wave-wave versus wave-induced mean flow interactions

    E-Print Network [OSTI]

    Sutherland, Bruce

    Internal wave instability: Wave-wave versus wave-induced mean flow interactions B. R. Sutherland fluid, vertically propagating internal gravity waves of moderately large amplitude can become unstable, energy from primary waves is transferred, for example, to waves with half frequency. Self

  8. Effect of anisotropy on HBT radii using leptonpair interferometry

    E-Print Network [OSTI]

    Payal Mohanty; Mahatsab Mandal; Pradip K Roy

    2014-11-10

    The effect of initial state momentum-space anisotropy on invariant mass dependence of HBT radii extracted from the leptonpair interferometry is presented here. We have studied the Bose-Einstein Correlation Function (BECF) for two identical virtual photons decaying to leptonpairs at most central collision of LHC energy having fixed transverse momentum of one of the virtual photons ($k_{1T}$= 2 GeV). The {\\em free streaming interpolating} model with fixed initial condition has been used for the evolution in anisotropic Quark Gluon Plasma (aQGP) and the relativistic (1+2)d hydrodynamics model with cylindrical symmetry and longitudinal boost invariance has been used for both isotropic Quark Gluon Plasma (iQGP) and hadronic phases. We found a significant change in the spatial and temporal dimension of the evolving system in presence of initial state momentum-space anisotropy.

  9. Anisotropies in magnetic field evolution and local Lyapunov exponents

    SciTech Connect (OSTI)

    Tang, X.Z.; Boozer, A.H.

    2000-01-13

    The natural occurrence of small scale structures and the extreme anisotropy in the evolution of a magnetic field embedded in a conducting flow is interpreted in terms of the properties of the local Lyapunov exponents along the various local characteristic (un)stable directions for the Lagrangian flow trajectories. The local Lyapunov exponents and the characteristic directions are functions of Lagrangian coordinates and time, which are completely determined once the flow field is specified. The characteristic directions that are associated with the spatial anisotropy of the problem, are prescribed in both Lagrangian and Eulerian frames. Coordinate transformation techniques are employed to relate the spatial distributions of the magnetic field, the induced current density, and the Lorentz force, which are usually followed in Eulerian frame, to those of the local Lyapunov exponents, which are naturally defined in Lagrangian coordinates.

  10. Anisotropies in magnetic field evolution and local Lyapunov exponents

    SciTech Connect (OSTI)

    Tang, X. Z. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Boozer, A. H. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)] [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2000-04-01

    The natural occurrence of small scale structures and the extreme anisotropy in the evolution of a magnetic field embedded in a conducting flow is interpreted in terms of the properties of the local Lyapunov exponents along the various local characteristic (un)stable directions for the Lagrangian flow trajectories. The local Lyapunov exponents and the characteristic directions are functions of Lagrangian coordinates and time, which are completely determined once the flow field is specified. The characteristic directions that are associated with the spatial anisotropy of the problem, are prescribed in both Lagrangian and Eulerian frames. Coordinate transformation techniques are employed to relate the spatial distributions of the magnetic field, the induced current density, and the Lorentz force, which are usually followed in Eulerian frame, to those of the local Lyapunov exponents, which are naturally defined in Lagrangian coordinates. (c) 2000 American Institute of Physics.

  11. Shallow Water Waves and Solitary Waves

    E-Print Network [OSTI]

    Hereman, Willy

    2013-01-01

    Encyclopedic article covering shallow water wave models used in oceanography and atmospheric science. Sections: Definition of the Subject; Introduction and Historical Perspective; Completely Integrable Shallow Water Wave Equations; Shallow Water Wave Equations of Geophysical Fluid Dynamics; Computation of Solitary Wave Solutions; Numerical Methods; Water Wave Experiments and Observations; Future Directions, and Bibliography.

  12. P wave anisotropy, stress, and crack distribution at Coso geothermal field,

    Open Energy Info (EERE)

    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 Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsourceII JumpQuarterly Smart GridNorth Carolina: Energy Resources Jump

  13. Analysing the impact of anisotropy pressure on tokamak equilibria

    E-Print Network [OSTI]

    Qu, Zhisong; Hole, Matthew John

    2014-01-01

    Neutral beam injection or ion cyclotron resonance heating induces pressure anisotropy. The axisymmetric plasma equilibrium code HELENA has been upgraded to include anisotropy and toroidal flow. With both analytical and numerical methods, we have studied the determinant factors in anisotropic equilibria and their impact on flux surfaces, magnetic axis shift, the displacement of pressures and density contours from flux surface. With $p_\\parallel/p_\\perp \\approx 1.5$, $p_\\perp$ can vary 20% on $s=0.5$ flux surface, in a MAST like equilibrium. We have also re-evaluated the widely applied approximation to anisotropy in which $p^*=(p_\\parallel + p_\\perp)/2$, the average of parallel and perpendicular pressure, is taken as the approximate isotropic pressure. We show that an isotropic reconstruction can infer a correct $p^*$, only by getting an incorrect $RB_\\varphi$. We find that in a MAST shot with $p_\\parallel/p_\\perp \\approx 1.25$, isotropic and anisotropic inference have a 3% difference in toroidal field but a 66...

  14. Azimuthal anisotropy distributions in high-energy collisions

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

    Yan, Li; Ollitrault, Jean-Yves; Poskanzer, Arthur M.

    2015-03-01

    Elliptic flow in ultrarelativistic heavy-ion collisions results from the hydrodynamic response to the spatial anisotropy of the initial density profile. A long-standing problem in the interpretation of flow data is that uncertainties in the initial anisotropy are mingled with uncertainties in the response. We argue that the non-Gaussianity of flow fluctuations in small systems with large fluctuations can be used to disentangle the initial state from the response. We apply this method to recent measurements of anisotropic flow in Pb+Pb and p+Pb collisions at the LHC, assuming linear response to the initial anisotropy. The response coefficient is found to decreasemore »as the system becomes smaller and is consistent with a low value of the ratio of viscosity over entropy of ?/s 0.19. Deviations from linear response are studied. While they significantly change the value of the response coefficient they do not change the rate of decrease with centrality. Thus, we argue that the estimate of ?/s is robust against non-linear effects.« less

  15. Obliquely propagating electromagnetic waves in magnetized kappa plasmas

    E-Print Network [OSTI]

    Gaelzer, Rudi

    2015-01-01

    Velocity distribution functions (VDFs) that exhibit a power-law dependence on the high-energy tail have been the subject of intense research by the plasma physics community. Such functions, known as kappa or superthermal distributions, have been found to provide a better fitting to the VDFs measured by spacecraft in the solar wind. One of the problems that is being addressed on this new light is the temperature anisotropy of solar wind protons and electrons. In the literature, the general treatment for waves excited by (bi-)Maxwellian plasmas is well-established. However, for kappa distributions, the wave characteristics have been studied mostly for the limiting cases of purely parallel or perpendicular propagation, relative to the ambient magnetic field. Contributions to the general case of obliquely-propagating electromagnetic waves have been scarcely reported so far. The absence of a general treatment prevents a complete analysis of the wave-particle interaction in kappa plasmas, since some instabilities c...

  16. Electron acceleration during the decay of nonlinear Whistler waves in low-beta electron-ion plasma

    SciTech Connect (OSTI)

    Umeda, Takayuki; Saito, Shinji; Nariyuki, Yasuhiro E-mail: saito@stelab.nagoya-u.ac.jp

    2014-10-10

    Relativistic electron acceleration through dissipation of a nonlinear, short-wavelength, and monochromatic electromagnetic whistler wave in low-beta plasma is investigated by utilizing a one-dimensional fully relativistic electromagnetic particle-in-cell code. The nonlinear (large-amplitude) parent whistler wave decays through the parametric instability which enhances electrostatic ion acoustic waves and electromagnetic whistler waves. These waves satisfy the condition of three-wave coupling. Through the decay instability, the energy of electron bulk velocity supporting the parent wave is converted to the thermal energy perpendicular to the background magnetic field. Increase of the perpendicular temperature triggers the electron temperature anisotropy instability which generates broadband whistler waves and heats electrons in the parallel direction. The broadband whistler waves are inverse-cascaded during the relaxation of the electron temperature anisotropy. In lower-beta conditions, electrons with a pitch angle of about 90° are successively accelerated by inverse-cascaded whistler waves, and selected electrons are accelerated to over a Lorentz factor of 10. The result implies that the nonlinear dissipation of a finite-amplitude and short-wavelength whistler wave plays an important role in producing relativistic nonthermal electrons over a few MeV especially at lower beta plasmas.

  17. Wave variability and wave spectra for wind generated gravity waves 

    E-Print Network [OSTI]

    Bretschneider, Charles L.

    1959-01-01

    A series of experiments of forces on a fixed vertical truncated column due to Stokes 5th order like waves were done in a wave tank. An effort was made to generate the waves as close as possible to theoretical Stokes 5th order waves. A systematic...

  18. Whistler anisotropy instabilities as the source of banded chorus: Van Allen Probes observations and particle-in-cell simulations

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

    Fu, Xiangrong; Cowee, Misa M.; Friedel, Reinhard H.; Funsten, Herbert O.; Gary, S. Peter; Hospodarsky, George B.; Kletzing, Craig; Kurth, William; Larsen, Brian A.; Liu, Kaijun; et al

    2014-10-22

    Magnetospheric banded chorus is enhanced whistler waves with frequencies ?r e, where ?e is the electron cyclotron frequency, and a characteristic spectral gap at ?r ? ?e/2. This paper uses spacecraft observations and two-dimensional particle-in-cell simulations in a magnetized, homogeneous, collisionless plasma to test the hypothesis that banded chorus is due to local linear growth of two branches of the whistler anisotropy instability excited by two distinct, anisotropic electron components of significantly different temperatures. The electron densities and temperatures are derived from Helium, Oxygen, Proton, and Electron instrument measurements on the Van Allen Probes A satellite during a bandedmore »chorus event on 1 November 2012. The observations are consistent with a three-component electron model consisting of a cold (a few tens of eV) population, a warm (a few hundred eV) anisotropic population, and a hot (a few keV) anisotropic population. The simulations use plasma and field parameters as measured from the satellite during this event except for two numbers: the anisotropies of the warm and the hot electron components are enhanced over the measured values in order to obtain relatively rapid instability growth. The simulations show that the warm component drives the quasi-electrostatic upper band chorus and that the hot component drives the electromagnetic lower band chorus; the gap at ~?e/2 is a natural consequence of the growth of two whistler modes with different properties.« less

  19. Graphene Signal Amplification for Sensitive and Real-Time Fluorescence Anisotropy Detection of Small Molecules

    E-Print Network [OSTI]

    Tan, Weihong

    Graphene Signal Amplification for Sensitive and Real-Time Fluorescence Anisotropy Detection graphene oxide (GO) as the signal amplifier. Because of the extraordinarily larger volume of GO

  20. Exact seismic velocities for VTI and HTI media and extended Thomsen Formulas for stronger anisotropies

    E-Print Network [OSTI]

    Berryman, J.G.

    2008-01-01

    Exploration, Seismic Exploration, Volume 29, Elsevier,fairly unrealistic model for seismic exploration problems (2002, Understanding Seismic Anisotropy in Exploration and

  1. Synchrotron X-ray Applications Toward an Understanding of Elastic Anisotropy

    E-Print Network [OSTI]

    Kanitpanyacharoen, Waruntorn

    2012-01-01

    dioxide storage potential of shales. Inter. J. Greenh. GasRock physics modeling of shale diagenesis. Petrol. Geosci. ,and anisotropy of Qusaiba Shales, Saudi Arabia. Geophys.

  2. Differential expansion of space and the Hubble flow anisotropy

    E-Print Network [OSTI]

    Krzysztof Bolejko; M. Ahsan Nazer; David L. Wiltshire

    2015-12-24

    The Universe on scales $10-100~h^{-1}$ Mpc is dominated by a cosmic web of voids, filaments, sheets and knots of galaxy clusters. These structures participate differently in the global expansion of the Universe: from non-expanding clusters to the above average expansion rate of voids. In this paper we characterize Hubble expansion anisotropies in the COMPOSITE sample of 4534 galaxies and clusters. We concentrate on the dipole and quadrupole in the rest frame of the Local Group. These both have statistically significant amplitudes. These anisotropies, and their redshift dependence, cannot be explained solely by a boost of the Local Group in the Friedmann-Lema\\^{i}tre-Robertson-Walker (FLRW) model which expands isotropically in the rest frame of the cosmic microwave background (CMB) radiation. We simulate the local expansion of the Universe with inhomogeneous Szekeres models, which match the standard FLRW model on $> 100~ h^{-1}$ Mpc scales but exhibit nonkinematic differential expansion on small scales. We restrict models to be consistent with observed CMB temperature anisotropies, while simultaneously fitting the redshift variation of the Hubble expansion dipole. We include features to account for both the Local Void and the "Great Attractor". While this naturally accounts for the Hubble expansion and CMB dipoles, the simulated quadrupoles are smaller than observed. Further refinement to incorporate additional structures may improve this. This would enable a test of the hypothesis that some large angle CMB anomalies result from failing to treat the differential expansion of space; a natural feature of Einstein's equations not included in the current standard model of cosmology.

  3. Differential expansion of space and the Hubble flow anisotropy

    E-Print Network [OSTI]

    Krzysztof Bolejko; M. Ahsan Nazer; David L. Wiltshire

    2015-12-23

    The Universe on scales $10-100~h^{-1}$ Mpc is dominated by a cosmic web of voids, filaments, sheets and knots of galaxy clusters. These structures participate differently in the global expansion of the Universe: from non-expanding clusters to the above average expansion rate of voids. In this paper we characterize Hubble expansion anisotropies in the COMPOSITE sample of 4534 galaxies and clusters. We concentrate on the dipole and quadrupole in the rest frame of the Local Group. These both have statistically significant amplitudes. These anisotropies, and their redshift dependence, cannot be explained solely by a boost of the Local Group in the Friedmann-Lema\\^{i}tre-Robertson-Walker (FLRW) model which expands isotropically in the rest frame of the cosmic microwave background (CMB) radiation. We simulate the local expansion of the Universe with inhomogeneous Szekeres models, which match the standard FLRW model on $> 100~ h^{-1}$ Mpc scales but exhibit nonkinematic differential expansion on small scales. We restrict models to be consistent with observed CMB temperature anisotropies, while simultaneously fitting the redshift variation of the Hubble expansion dipole. We include features to account for both the Local Void and the "Great Attractor". While this naturally accounts for the Hubble expansion and CMB dipoles, the simulated quadrupoles are smaller than observed. Further refinement to incorporate additional structures may improve this. This would enable a test of the hypothesis that some large angle CMB anomalies result from failing to treat the differential expansion of space; a natural feature of Einstein's equations not included in the current standard model of cosmology.

  4. Localization of Classical Waves I: Acoustic Waves.

    E-Print Network [OSTI]

    Localization of Classical Waves I: Acoustic Waves. Alexander Figotin \\Lambda Department, 1997 Abstract We consider classical acoustic waves in a medium described by a position dependent mass the existence of localized waves, i.e., finite energy solutions of the acoustic equations with the property

  5. Coda wave interferometry 1 Coda wave interferometry

    E-Print Network [OSTI]

    Snieder, Roel

    Coda wave interferometry 1 Coda wave interferometry An interferometer is an instrument that is sensitive to the interference of two or more waves (optical or acoustic). For example, an optical interferometer uses two interfering light beams to measure small length changes. Coda wave interferometry

  6. Large-Scale Anisotropy of EGRET Gamma Ray Sources

    E-Print Network [OSTI]

    Luis Anchordoqui; Thomas McCauley; Thomas Paul; Olaf Reimer; Diego F. Torres

    2005-06-24

    In the course of its operation, the EGRET experiment detected high-energy gamma ray sources at energies above 100 MeV over the whole sky. In this communication, we search for large-scale anisotropy patterns among the catalogued EGRET sources using an expansion in spherical harmonics, accounting for EGRET's highly non-uniform exposure. We find significant excess in the quadrupole and octopole moments. This is consistent with the hypothesis that, in addition to the galactic plane, a second mid-latitude (5^{\\circ} < |b| < 30^{\\circ}) population, perhaps associated with the Gould belt, contributes to the gamma ray flux above 100 MeV.

  7. Statistical anisotropy of the curvature perturbation from vector field perturbations

    SciTech Connect (OSTI)

    Dimopoulos, Konstantinos; Karciauskas, Mindaugas; Lyth, David H.; Rodriguez, Yeinzon E-mail: m.karciauskas@lancaster.ac.uk E-mail: yeinzon.rodriguez@uan.edu.co

    2009-05-15

    The {delta}N formula for the primordial curvature perturbation {zeta} is extended to include vector as well as scalar fields. Formulas for the tree-level contributions to the spectrum and bispectrum of {zeta} are given, exhibiting statistical anisotropy. The one-loop contribution to the spectrum of {zeta} is also worked out. We then consider the generation of vector field perturbations from the vacuum, including the longitudinal component that will be present if there is no gauge invariance. Finally, the {delta}N formula is applied to the vector curvaton and vector inflation models with the tensor perturbation also evaluated in the latter case.

  8. Experimental investigation of magnetic anisotropy in spin vortex discs

    SciTech Connect (OSTI)

    Garraud, N. Arnold, D. P.

    2014-05-07

    We present experimental 2D vector vibrating sample magnetometer measurements to demonstrate the shape anisotropy effects occurring in micrometer-diameter supermalloy spin vortex discs. Measurements made for different disc sizes and orientations confirm the out-of-plane susceptibility is several orders of magnitude smaller than the in-plane susceptibility. These results validate with a high certitude that spin vortices with high diameter to thickness ratio retain in-plane-only magnetization, even when subjected to fields in the out-of-plane direction. These results contribute to further computational simulations of the dynamics of spin vortex structures in colloidal suspensions where external fields may be applied in any arbitrary direction.

  9. Breaking the mass / anisotropy degeneracy in the Coma cluster

    E-Print Network [OSTI]

    Gary A. Mamon; Ewa L. Lokas; Teresa Sanchis

    2004-04-21

    We provide the first direct lifting of the mass/anisotropy degeneracy for a cluster of galaxies, by jointly fitting the line of sight velocity dispersion and kurtosis profiles of the Coma cluster, assuming an NFW tracer density profile, a generalized-NFW dark matter profile and a constant anisotropy profile. We find that the orbits in Coma must be quasi-isotropic, and find a mass consistent with previous analyses, but a concentration parameter 50% higher than expected in cosmological N-body simulations. We then test the accuracy of our method on realistic non-spherical systems with substructure and streaming motions, by applying it to the ten most massive structures in a cosmological N-body simulation. We find that our method yields fairly accurate results on average (within 20%), although with a wide variation (factor 1.7 at 1 sigma) for the concentration parameter, with decreased accuracy and efficiency when the projected mean velocity is not constant with radius.

  10. Tensor anisotropy as a tracer of cosmic voids

    E-Print Network [OSTI]

    Bustamante, Sebastian

    2015-01-01

    We present a new method to find voids in cosmological simulations based on the tidal and the velocity shear tensors definitions of the cosmic web. We use the fractional anisotropy (FA) computed from the eigenvalues of each web scheme as a void tracer. We identify voids using a watershed transform based on the local minima of the FA field without making any assumption on the shape or structure of the voids. We test the method on the Bolshoi simulation and report on the abundance and radial averaged profiles for the density, velocity and fractional anisotropy. We find that voids in the velocity shear web are smaller than voids in the tidal web, with a particular overabundance of very small voids in the inner region of filaments/sheets. We classify voids as subcompensated/overcompansated depending on the absence/presence of an overdense matter ridge in their density profile, finding that close to $65\\%$ and $35\\%$ of the total population are classified into each category, respectively. Finally, we find evidence ...

  11. Azimuthal anisotropy and fundamental symmetries in QCD matter at RHIC

    E-Print Network [OSTI]

    V. A. Okorokov

    2008-09-18

    A study of collective behavior in heavy ion collisions provides one of the most sensitive and promising probes for investigation of possible formation of new extreme state of strong interacting matter and elucidating its properties. Systematic of experimental results for final state azimuthal anisotropy is presented for heavy ion interactions at RHIC. Experimental data for azimuthal anisotropy indicate that the final state strongly interacting matter under extreme conditions behaves as near-ideal liquid rather, than ideal gas of quarks and gluons. The strong quenching of jets and the dramatic modification of jet-like azimuthal correlations, observed in ${Au+Au}$ collisions, are evidences of the extreme energy loss of partons traversing matter which contains a large density of color charges. For the first time, dependence of the jet suppression on orientation of a jet with respect to the reaction plane is found at RHIC experimentally. The model of compound collective flow and corresponding analytic approach are discussed. The possible violations of $\\cal{P}$ and $\\cal{CP}$ symmetries of strong interactions in heavy ion collisions at different initial energies are considered. Thus, now the fact is established firmly, that extremely hot and dense matter created in relativistic heavy ion collisions at RHIC differs dramatically from everything that was observed and investigated before.

  12. Optical Anisotropy of Schwarzschild Metric within Equivalent Medium Framework

    E-Print Network [OSTI]

    Sina Khorasani; Bizhan Rashidian

    2009-12-16

    It is has been long known that the curved space in the presence of gravitation can be described as a non-homogeneous anisotropic medium in flat geometry with different constitutive equations. In this article, we show that the eigenpolarizations of such medium can be exactly solved, leading to a pseudo-isotropic description of curved vacuum with two refractive index eigenvalues having opposite signs, which correspond to forward and backward travel in time. We conclude that for a rotating universe, time-reversal symmetry is broken. We also demonstrate the applicability of this method to Schwarzschild metric and derive exact forms of refractive index. We derive the subtle optical anisotropy of space around a spherically symmetric, non-rotating and uncharged blackhole in the form of an elegant closed form expression, and show that the refractive index in such a pseudo-isotropic system would be a function of coordinates as well as the direction of propagation. Corrections arising from such anisotropy in the bending of light are shown and a simplified system of equations for ray-tracing in the equivalent medium of Schwarzschild metric is found.

  13. Azimuthal anisotropy in U+U collisions at STAR

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

    Wang, Hui; Sorensen, Paul

    2014-12-01

    The azimuthal anisotropy of particle production is commonly used in high-energy nuclear collisions to study the early evolution of the expanding system. The prolate shape of uranium nuclei makes it possible to study how the geometry of the colliding nuclei affects #12;final state anisotropies. It also provides a unique opportunity to understand how entropy is produced in heavy ion collisions. In this paper, the two- and four- particle cumulant v2 (v2{2} and v2{4}) from U+U collisions at ?sNN = 193 GeV and Au+Au collisions at ?sNN = 200 GeV for inclusive charged hadrons will be presented. The STAR Zero Degree Calorimeters are used to select very central collisions. Differences were observed between the multiplicity dependence of v2{2} for most central Au+Au and U+U collisions. The multiplicity dependence of v2{2} in central collisions were compared to Monte Carlo Glauber model predictions and it was seen that this model cannot explain the present results. (auth)

  14. Azimuthal anisotropy in U+U collisions at STAR

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

    Wang, Hui; Sorensen, Paul

    2014-10-06

    The azimuthal anisotropy of particle production is commonly used in high-energy nuclear collisions to study the early evolution of the expanding system. The prolate shape of uranium nuclei makes it possible to study how the geometry of the colliding nuclei affects #12;final state anisotropies. It also provides a unique opportunity to understand how entropy is produced in heavy ion collisions. In this paper, the two- and four- particle cumulant v2 (v2{2} and v2{4}) from U+U collisions at ?sNN = 193 GeV and Au+Au collisions at ?sNN = 200 GeV for inclusive charged hadrons will be presented. The STAR Zero Degreemore »Calorimeters are used to select very central collisions. Differences were observed between the multiplicity dependence of v2{2} for most central Au+Au and U+U collisions. The multiplicity dependence of v2{2} in central collisions were compared to Monte Carlo Glauber model predictions and it was seen that this model cannot explain the present results. (auth)« less

  15. Kirchhoff prestack depth migration in 3-D models: Comparison of triclinic anisotropy

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    Kirchhoff prestack depth migration in 3-D models: Comparison of triclinic anisotropy with simpler the Kirchhoff prestack depth migration to the calculation of migrated sections in 3-D simple anisotropic. We test Kirchhoff prestack depth migration in velocity models with different types of anisotropy

  16. Magnetic fluctuation power near proton temperature anisotropy instability thresholds in the solar wind

    E-Print Network [OSTI]

    California at Berkeley, University of

    Magnetic fluctuation power near proton temperature anisotropy instability thresholds in the solar wind S. D. Bale, J. C. Kasper, G. G. Howes, E. Quataert,§ C. Salem,¶ and D. Sundkvist¶ (Dated: August 10, 2009) The proton temperature anisotropy in the solar wind is known to be constrained by the theo

  17. Azimuthal anisotropy in high-energy heavy-ion collisions at RHIC energies

    E-Print Network [OSTI]

    ShinIchi Esumi

    2004-05-19

    Directed and elliptic event anisotropy parameters measured in the experiments at relativistic heavy-ion collider are presented. The possible origin of the measured elliptic anisotropy parameter $v_2$ and its sensitivity to the early phase of the high-energy heavy-ion collisions are discussed.

  18. Optical anisotropy and liquid-crystal alignment properties of rubbed polyimide layers

    E-Print Network [OSTI]

    Exeter, University of

    Optical anisotropy and liquid-crystal alignment properties of rubbed polyimide layers FUZI YANG polyimide layers and the rubbing process is investigated using the recently developed polarization-conversion guided mode technique. Results indicate that the effective optical anisotropy of the polyimide layers may

  19. The Inertial Anisotropy of the Arm Is Accurately Predicted during Movement Planning

    E-Print Network [OSTI]

    Flanagan, Randy

    The Inertial Anisotropy of the Arm Is Accurately Predicted during Movement Planning J. Randall and environment to predict the sensory consequences of motor commands. In arm movement control, a critical factor the inertial anisotropy of the arm, which refers to the fact that the inertial resistance of the arm depends

  20. Is inner core seismic anisotropy a marker of plastic flow of cubic iron?

    E-Print Network [OSTI]

    Lincot, A; Cardin, Philippe

    2015-01-01

    This paper investigates whether observations of seismic anisotropy are compatible with a cubic structure of the inner core Fe alloy. We assume that anisotropy is the result of plastic deformation within a large scale flow induced by preferred growth at the inner core equator. Based on elastic moduli from the literature, bcc- or fcc-Fe produce seismic anisotropy well below seismic observations ($\\textless{}0.4\\%$). A Monte-Carlo approach allows us to generalize this result to any form of elastic anisotropy in a cubic system. Within our model, inner core global anisotropy is not compatible with a cubic structure of Fe alloy. Hence, if the inner core material is indeed cubic, large scale coherent anisotropic structures, incompatible with plastic deformation induced by large scale flow, must be present.

  1. Seismic velocity and Q anisotropy in fractured poroelastic media

    E-Print Network [OSTI]

    The energy-velocity vector ve of the qP and qSV waves is ..... A., On the spatial variability of parameters of the unsaturated hydraulic conductivity, Water Res.

  2. Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba...

    Office of Scientific and Technical Information (OSTI)

    Observed for Detwinned Ba(Fe (1-X) Co (X) ) (2) As (2) Above the Spin Density Wave Transition Citation Details In-Document Search Title: Symmetry-Breaking Orbital...

  3. Wave Energy Basics

    Broader source: Energy.gov [DOE]

    Wave energy technologies extract energy directly from surface waves or from pressure fluctuations below the surface. Renewable energy analysts believe there is enough energy in ocean waves to provide up to 2 terawatts of electricity.

  4. Wave Control Introduction

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    focussing: in crossing seas due to coastal or submarine convergences. Moreover, (rogue) wave energy devices maker to create the highest rogue wave? geometry and dynamo in a new rogue wave energy device? maximum

  5. Wave mechanics in media pinned at Bravais lattice points

    E-Print Network [OSTI]

    Mehul Makwana; Tryfon Antonakakis; Ben Maling; Sebastien Guenneau; Richard Craster

    2015-05-12

    The propagation of waves through microstructured media with periodically arranged inclusions has applications in many areas of physics and engineering, stretching from photonic crystals through to seismic metamaterials. In the high-frequency regime, modelling such behaviour is complicated by multiple scattering of the resulting short waves between the inclusions. Our aim is to develop an asymptotic theory for modelling systems with arbitrarily-shaped inclusions located on general Bravais lattices. We then consider the limit of point-like inclusions, the advantage being that exact solutions can be obtained using Fourier methods, and go on to derive effective medium equations using asymptotic analysis. This approach allows us to explore the underlying reasons for dynamic anisotropy, localisation of waves, and other properties typical of such systems, and in particular their dependence upon geometry. Solutions of the effective medium equations are compared with the exact solutions, shedding further light on the underlying physics. We focus on examples that exhibit dynamic anisotropy as these demonstrate the capability of the asymptotic theory to pick up detailed qualitative and quantitative features.

  6. Large Scale Cosmic Microwave Background Anisotropies and Dark Energy

    E-Print Network [OSTI]

    J. Weller; A. M. Lewis

    2003-08-29

    In this note we investigate the effects of perturbations in a dark energy component with a constant equation of state on large scale cosmic microwave background anisotropies. The inclusion of perturbations increases the large scale power. We investigate more speculative dark energy models with w<-1 and find the opposite behaviour. Overall the inclusion of perturbations in the dark energy component increases the degeneracies. We generalise the parameterization of the dark energy fluctuations to allow for an arbitrary const ant sound speeds and show how constraints from cosmic microwave background experiments change if this is included. Combining cosmic microwave background with large scale structure, Hubble parameter and Supernovae observations we obtain w=-1.02+-0.16 (1 sigma) as a constraint on the equation of state, which is almost independent of the sound speed chosen. With the presented analysis we find no significant constraint on the constant speed of sound of the dark energy component.

  7. First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Emission

    E-Print Network [OSTI]

    C. Bennett; R. S. Hill; G. Hinshaw; M. R. Nolta; N. Odegard; L. Page; D. N. Spergel; J. L. Weiland; E. L. Wright; M. Halpern; N. Jarosik; A. Kogut; M. Limon; S. S. Meyer; G. S. Tucker; E. Wollack

    2003-06-05

    Full sky maps are made in five microwave frequency bands to separate the temperature anisotropy of the CMB from foreground emission. We define masks that excise regions of high foreground emission. The effectiveness of template fits to remove foreground emission from the WMAP data is examined. These efforts result in a CMB map with minimal contamination and a demonstration that the WMAP CMB power spectrum is insensitive to residual foreground emission. We construct a model of the Galactic emission components. We find that the Milky Way resembles other normal spiral galaxies between 408 MHz and 23 GHz, with a synchrotron spectral index that is flattest (beta ~ -2.5) near star-forming regions, especially in the plane, and steepest (beta ~ -3) in the halo. The significant synchrotron index steepening out of the plane suggests a diffusion process in which the halo electrons are trapped in the Galactic potential long enough to suffer synchrotron and inverse Compton energy losses and hence a spectral steepening. The synchrotron index is steeper in the WMAP bands than in lower frequency radio surveys, with a spectral break near 20 GHz to beta < -3. The modeled thermal dust spectral index is also steep in the WMAP bands, with beta ~ 2.2. Microwave and H alpha measurements of the ionized gas agree. Spinning dust emission is limited to < ~5% of the Ka-band foreground emission. A catalog of 208 point sources is presented. Derived source counts suggest a contribution to the anisotropy power from unresolved sources of (15.0 +- 1.4) 10^{-3} microK^2 sr at Q-band and negligible levels at V-band and W-band.

  8. Geometrical vs wave optics under gravitational waves

    E-Print Network [OSTI]

    Raymond Angélil; Prasenjit Saha

    2015-05-20

    We present some new derivations of the effect of a plane gravitational wave on a light ray. A simple interpretation of the results is that a gravitational wave causes a phase modulation of electromagnetic waves. We arrive at this picture from two contrasting directions, namely null geodesics and Maxwell's equations, or, geometric and wave optics. Under geometric optics, we express the geodesic equations in Hamiltonian form and solve perturbatively for the effect of gravitational waves. We find that the well-known time-delay formula for light generalizes trivially to massive particles. We also recover, by way of a Hamilton-Jacobi equation, the phase modulation obtained under wave optics. Turning then to wave optics - rather than solving Maxwell's equations directly for the fields, as in most previous approaches - we derive a perturbed wave equation (perturbed by the gravitational wave) for the electromagnetic four-potential. From this wave equation it follows that the four-potential and the electric and magnetic fields all experience the same phase modulation. Applying such a phase modulation to a superposition of plane waves corresponding to a Gaussian wave packet leads to time delays.

  9. Electric-field-induced spin wave generation using multiferroic magnetoelectric cells

    SciTech Connect (OSTI)

    Cherepov, Sergiy; Khalili Amiri, Pedram; Alzate, Juan G.; Wong, Kin; Lewis, Mark; Upadhyaya, Pramey; Nath, Jayshankar; Bao, Mingqiang; Wang, Kang L.; Bur, Alexandre; Wu, Tao; Carman, Gregory P.; Khitun, Alexander

    2014-02-24

    In this work, we report on the demonstration of voltage-driven spin wave excitation, where spin waves are generated by multiferroic magnetoelectric (ME) cell transducers driven by an alternating voltage, rather than an electric current. A multiferroic element consisting of a magnetostrictive Ni film and a piezoelectric [Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}]{sub (1?x)}–[PbTiO{sub 3}]{sub x} substrate was used for this purpose. By applying an AC voltage to the piezoelectric, an oscillating electric field is created within the piezoelectric material, which results in an alternating strain-induced magnetic anisotropy in the magnetostrictive Ni layer. The resulting anisotropy-driven magnetization oscillations propagate in the form of spin waves along a 5??m wide Ni/NiFe waveguide. Control experiments confirm the strain-mediated origin of the spin wave excitation. The voltage-driven spin wave excitation, demonstrated in this work, can potentially be used for low-dissipation spin wave-based logic and memory elements.

  10. CONSTRAINTS ON THE SOURCE OF ULTRA-HIGH-ENERGY COSMIC RAYS USING ANISOTROPY VERSUS CHEMICAL COMPOSITION

    SciTech Connect (OSTI)

    Liu, Ruo-Yu; Wang, Xiang-Yu [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Taylor, Andrew M. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Lemoine, Martin [Institut d'Astrophysique de Paris, CNRS, UPMC, 98 bis Boulevard Arago, F-75014 Paris (France); Waxman, Eli, E-mail: lemoine@iap.fr [Physics Faculty, Weizmann Institute, P.O. Box 26, Rehovot 7600 (Israel)

    2013-10-20

    The joint analysis of anisotropy signals and chemical composition of ultra-high-energy cosmic rays offers strong potential for shedding light on the sources of these particles. Following up on an earlier idea, this paper studies the anisotropies produced by protons of energy >E/Z, assuming that anisotropies at energy >E have been produced by nuclei of charge Z, which share the same magnetic rigidity. We calculate the number of secondary protons produced through photodisintegration of the primary heavy nuclei. Making the extreme assumption that the source does not inject any proton, we find that the source(s) responsible for anisotropies such as reported by the Pierre Auger Observatory should lie closer than ?20-30, 80-100, and 180-200 Mpc if the anisotropy signal is mainly composed of oxygen, silicon, and iron nuclei, respectively. A violation of this constraint would otherwise result in the secondary protons forming a more significant anisotropy signal at lower energies. Even if the source were located closer than this distance, it would require an extraordinary metallicity ?> 120, 1600, and 1100 times solar metallicity in the acceleration zone of the source, for oxygen, silicon, and iron, respectively, to ensure that the concomitantly injected protons do not produce a more significant low-energy anisotropy. This offers interesting prospects for constraining the nature and the source of ultra-high-energy cosmic rays with the increase in statistics expected from next-generation detectors.

  11. Whistler anisotropy instabilities as the source of banded chorus: Van Allen Probes observations and particle-in-cell simulations

    SciTech Connect (OSTI)

    Fu, Xiangrong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cowee, Misa M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Friedel, Reinhard H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Funsten, Herbert O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gary, S. Peter [Space Science Institute, Boulder, CO (United States); Hospodarsky, George B. [Univ. of Iowa, Iowa City, IA (United States). Dept. of Physics and Astronomy.; Kletzing, Craig [Univ. of Iowa, Iowa City, IA (United States). Dept. of Physics and Astronomy.; Kurth, William [Univ. of Iowa, Iowa City, IA (United States). Dept. of Physics and Astronomy.; Larsen, Brian A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Liu, Kaijun [Auburn Univ., Auburn, AL (United States). Dept. of Physics.; MacDonald, Elizabeth A. [NASA/Goddard Space Flight Center, Greenbelt, MD (United States); Min, Kyungguk [Auburn Univ., Auburn, AL (United States). Dept. of Physics.; Reeves, Geoffrey D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skoug, Ruth M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Winske, Dan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-22

    Magnetospheric banded chorus is enhanced whistler waves with frequencies ?r < ?e, where ?e is the electron cyclotron frequency, and a characteristic spectral gap at ?r ? ?e/2. This paper uses spacecraft observations and two-dimensional particle-in-cell simulations in a magnetized, homogeneous, collisionless plasma to test the hypothesis that banded chorus is due to local linear growth of two branches of the whistler anisotropy instability excited by two distinct, anisotropic electron components of significantly different temperatures. The electron densities and temperatures are derived from Helium, Oxygen, Proton, and Electron instrument measurements on the Van Allen Probes A satellite during a banded chorus event on 1 November 2012. The observations are consistent with a three-component electron model consisting of a cold (a few tens of eV) population, a warm (a few hundred eV) anisotropic population, and a hot (a few keV) anisotropic population. The simulations use plasma and field parameters as measured from the satellite during this event except for two numbers: the anisotropies of the warm and the hot electron components are enhanced over the measured values in order to obtain relatively rapid instability growth. The simulations show that the warm component drives the quasi-electrostatic upper band chorus and that the hot component drives the electromagnetic lower band chorus; the gap at ~?e/2 is a natural consequence of the growth of two whistler modes with different properties.

  12. Electromagnetic waves near the proton cyclotron frequency: Stereo observations

    SciTech Connect (OSTI)

    Jian, L. K.; Wei, H. Y.; Russell, C. T.; Luhmann, J. G.; Klecker, B.; Omidi, N.; Isenberg, P. A.; Goldstein, M. L.; Figueroa-Viñas, A.; Blanco-Cano, X.

    2014-05-10

    Transverse, near-circularly polarized, parallel-propagating electromagnetic waves around the proton cyclotron frequency were found sporadically in the solar wind throughout the inner heliosphere. They could play an important role in heating and accelerating the solar wind. These low-frequency waves (LFWs) are intermittent but often occur in prolonged bursts lasting over 10 minutes, named 'LFW storms'. Through a comprehensive survey of them from Solar Terrestrial Relations Observatory A using dynamic spectral wave analysis, we have identified 241 LFW storms in 2008, present 0.9% of the time. They are left-hand (LH) or right-hand (RH) polarized in the spacecraft frame with similar characteristics, probably due to Doppler shift of the same type of waves or waves of intrinsically different polarities. In rare cases, the opposite polarities are observed closely in time or even simultaneously. Having ruled out interplanetary coronal mass ejections, shocks, energetic particles, comets, planets, and interstellar ions as LFW sources, we discuss the remaining generation scenarios: LH ion cyclotron instability driven by greater perpendicular temperature than parallel temperature or by ring-beam distribution, and RH ion fire hose instability driven by inverse temperature anisotropy or by cool ion beams. The investigation of solar wind conditions is compromised by the bias of the one-dimensional Maxwellian fit used for plasma data calibration. However, the LFW storms are preferentially detected in rarefaction regions following fast winds and when the magnetic field is radial. This preference may be related to the ion cyclotron anisotropy instability in fast wind and the minimum in damping along the radial field.

  13. Coverage and large scale anisotropies estimation methods for the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Hamilton, Jean-Christophe; /Paris, IN2P3

    2005-07-01

    When searching for anisotropies in the arrival directions of Ultra High Energy Cosmic Rays, one must estimate the number of events expected in each direction of the sky in the case of a perfect isotropy. We present in this article a new method, developed for the Auger Observatory, based on a smooth estimate of the zenith angle distribution obtained from the data itself (which is essentially unchanged in the case of the presence of a large scale anisotropy pattern). We also study the sensitivity of several methods to detect large-scale anisotropies in the cosmic ray arrival direction distribution : Rayleigh analysis, dipole fitting and angular power spectrum estimation.

  14. Magnetocrystalline Anisotropy in UMn2Ge2 and Related Mn-based Actinide Ferromagnets

    SciTech Connect (OSTI)

    Parker, David S; Mandrus, D.; Ghimire, N J; Baumbach, Ryan; Singleton, John; Thompson, J.D.; Bauer, Eric D.; Li, Ling; Singh, David J

    2015-01-01

    We present magnetization isotherms in pulsed magnetic fields up to 62 Tesla, supported by first principles calculations, demonstrating a huge uniaxial magnetocrystalline anisotropy energy - approximately 20 MJ/m3 - in UMn2Ge2. This large anisotropy results from the extremely strong spin-orbit coupling affecting the uranium 5 f electrons, which in the calculations exhibit a substantial orbital moment exceeding 2 Bohr magnetons. We also find from theoretical calculations that a number of isostructural Mn-actinide compounds are expected to have similarly large anisotropy.

  15. Big Flippin' Wave Science

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    Verdes, Campus Point, Coal Oil Point (Sands) Waves propagate perpendicular to isobaths (lines of constant

  16. Water Waves Roger Grimshaw

    E-Print Network [OSTI]

    Water Waves Roger Grimshaw May 7, 2003 Abstract A short review of the theory of weakly nonlinear water waves, prepared for the forthcoming Encyclopedia of Nonlinear Science 1 Introduction Water waves nonlinear waves. Throughout the theory is based on the traditional assumptions that water is inviscid

  17. the wave model A traveling wave is an organized disturbance

    E-Print Network [OSTI]

    Winokur, Michael

    1 waves the wave model A traveling wave is an organized disturbance propagating at a well-defined wave speed v. · In transverse waves the particles of the medium move perpendicular to the direction of wave propagation. · In longitudinal waves the particles of the medium move parallel to the direction

  18. Localization of Matter Fields in the 5D Standing Wave Braneworld

    E-Print Network [OSTI]

    Merab Gogberashvili

    2012-08-23

    We investigate the localization problem of matter fields within the 5D standing wave braneworld. In this model the brane emits anisotropic waves into the bulk with different amplitudes along different spatial dimensions. We show that in the case of increasing warp factor there exist the pure gravitational localization of all kinds of quantum and classical particles on the brane. For classical particles the anisotropy of the background metric is hidden, brane fields exhibit standard Lorentz symmetry in spite of anisotropic nature of the primordial 5D metric.

  19. Pressure anisotropy and By in the magnetotail current sheet Richard L. Kaufmann, Bryan M. Ball

    E-Print Network [OSTI]

    Kaufmann, Richard L.

    Department of Physics, University of New Hampshire, Durham W. R. Paterson and L. A. Frank Department motion or parallel electric fields. The pressure anisotropies were only large enough to provide from 10

  20. Contact and Stress Anisotropies in Start-Up Flow of Colloidal...

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

    Contact and Stress Anisotropies in Start-Up Flow of Colloidal Suspensions Authors: Martys, N.S., Lootens, D., George, W., and H Spatiotemporal correlations in start-up flows of...

  1. Identification of crystalline elastic anisotropy in PZT ceramics from in-situ blocking stress measurements

    SciTech Connect (OSTI)

    Daniel, L., E-mail: laurent.daniel@u-psud.fr [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); LGEP (CNRS UMR8507, SUPELEC, UPMC, Univ Paris-Sud), 91192 Gif sur Yvette cedex (France); Hall, D. A.; Withers, P. J. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Webber, K. G. [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); King, A. [European Synchrotron Radiation Facility (ESRF), 6 rue J. Horowitz, 38043 Grenoble (France); Synchrotron SOLEIL, BP 48, 91192 Gif sur Yvette cedex (France)

    2014-05-07

    High energy x-ray diffraction measurements of lattice strains were performed on a rhombohedral Lead Zirconate Titanate ceramic (PZT 55-45) under combinations of applied electric field and compressive stress. These measurements allow the construction of blocking stress curves for different sets of crystallographic orientations which reflect the single crystal elastic anisotropy. A micro-mechanical interpretation of the results is then proposed. Assuming cubic symmetry for the crystalline elastic stiffness tensor and isotropy for the macroscopic elastic properties, the elastic properties of the single crystal are extracted from the measured data. An anisotropy ratio close to 0.3 is found (compared to 1 for isotropic materials). The high level of anisotropy found in this work suggests that crystalline elastic anisotropy should not be neglected in the modelling of ferroelectric materials.

  2. Aligned vertical fractures, HTI reservoir symmetry, and Thomsen seismic anisotropy parameters for polar media

    E-Print Network [OSTI]

    Berryman, James G.

    2008-01-01

    Seismic Exploration, Volume 29, Elsevier, Amsterdam. Vernik2002. Understanding Seismic Anisotropy in Exploration andSeismic Signatures and Analysis of Re?ection Data in Anisotropic Me- dia, handbook of Geophysical Exploration,

  3. Evaluating permeability anisotropy in the early Jurassic Tilje formation, offshore mid-Norway 

    E-Print Network [OSTI]

    Aliyev, Kanan

    2005-11-01

    The problem of evaluating permeability anisotropy in the Tilje Formation, Heidrum field, offshore mid-Norway, has been investigated by the Statoil Research Centre by a detailed combination of the geological and petrophysical data. The large...

  4. Static Quark Potential and the Renormalized Anisotropy on Tadpole Improved Anisotropic Lattices

    E-Print Network [OSTI]

    Wei Liu; Ying Chen; Ming Gong; Xin Li; Chuan Liu; Guozhan Meng

    2006-03-15

    Static quark potential is studied using a tadpole improved gauge lattice action. The scale is set using the potential for a wide range of bare parameters. The renormalized anisotropy of the lattice is also measured.

  5. Numerical Analysis of Non-Uniformities and Anisotropy in High-Temperature Superconducting Coils

    E-Print Network [OSTI]

    Hu, Di; Ainslie, Mark D.; Zou, Jin; Cardwell, David A.

    2014-12-12

    —High-temperature superconducting (HTS) coils play an important role in a number of large-scale engineering applications, such as electric machines employing HTS coated conductors. Non-uniformities and anisotropy in the properties of the coated...

  6. Author's personal copy Initial anisotropy in demineralized bovine cortical bone in compressive

    E-Print Network [OSTI]

    McKittrick, Joanna

    Author's personal copy Initial anisotropy in demineralized bovine cortical bone in compressive Cortical bone Cyclic compression Demineralization The mechanical properties of demineralized bovine and transverse directions. The bone was demineralized by 10% ethylenediaminetetraacetic acid (EDTA) (100% protein

  7. CMB anisotropy power spectrum using linear combinations of WMAP maps Rajib Saha,1,2,3

    E-Print Network [OSTI]

    Souradeep, Tarun

    CMB anisotropy power spectrum using linear combinations of WMAP maps Rajib Saha,1,2,3 Simon Prunet year WMAP data by Saha et al. 2006. All previous estimates of the power spectrum of the CMB are based

  8. Optimization and Applications of Fluorescence anisotropy assays and Fluorescence Resonance Energy Transfer Measurements

    E-Print Network [OSTI]

    Liyanage, Mangala Roshan

    2009-01-01

    Calmodulin (CaM) is a calcium signaling protein that activates over hundred of targets including PMCA. This dissertation mainly focuses on optimizing and applications of fluorescence anisotropy (FA) and FRET experiments for CaM-target interactions...

  9. Structure formation and CMBR anisotropy spectrum in the inflessence model

    E-Print Network [OSTI]

    A. A. Sen; V. F. Cardone; S. Capozziello; A. Troisi

    2006-07-25

    The inflessence model has recently been proposed in an attempt to explain both early inflation and present day accelerated expansion within a single mechanism. The model has been successfully tested against the Hubble diagram of Type Ia Supernovae, the shift parameter, and the acoustic peak parameter. As a further mandatory test, we investigate here structure formation in the inflessence model determining the evolution of matter density contrast $\\delta \\equiv \\delta \\rho_M/\\rho_M$ in the linear regime. We compare the growth factor $D(a) \\equiv \\delta/a$ and the growth index $f(z) \\equiv d\\ln{\\delta}/d\\ln{a}$ to these same quantities for the successful concordance $\\Lambda$CDM model with a particular emphasis on the role of the inflessence parameters $(\\gamma, z_Q)$. We also evaluate the anisotropy spectrum of the cosmic microwave background radiation (CMBR) to check whether the inflessence model may be in agreement with the observations. We find that, for large values of $(\\gamma, z_Q)$, structure formation proceeds in a similar way to that in the $\\Lambda$CDM scenario, and it is also possible to nicely fit the CMBR spectrum.

  10. Dielectric anisotropy in polar solvents under external fields

    E-Print Network [OSTI]

    Sahin Buyukdagli

    2015-07-23

    We investigate dielectric saturation and increment in polar liquids under external fields. We couple a previously introduced dipolar solvent model to a uniform electric field and derive the electrostatic kernel of interacting dipoles. This procedure allows an unambiguous definition of the liquid dielectric permittivity embodying non-linear dielectric response and correlation effects.We find that the presence of the external field results in a dielectric anisotropy characterized by a two-component dielectric permittivity tensor. The increase of the electric field amplifies the permittivity component parallel to the field direction, i.e. dielectric increment is observed along the field. However, the perpendicular component is lowered below the physiological permittivity, indicating dielectric saturation perpendicular to the field. By comparison with Molecular Dynamics simulations from the literature, we show that the mean-field level dielectric response theory underestimates dielectric saturation. The inclusion of dipolar correlations at the weak-coupling level intensify the mean-field level dielectric saturation and improves the agreement with simulation data at weak electric fields. The correlation-corrected theory predicts as well the presence of a metastable configuration corresponding to the antiparallel alignment of dipoles with the field. This prediction can be verified by solvent-explicit simulations where solvent molecules are expected to be trapped transiently in this metastable state.

  11. (An)isotropy of the Hubble diagram: comparing hemispheres

    E-Print Network [OSTI]

    Dominik J. Schwarz; Bastian Weinhorst

    2007-09-12

    We test the isotropy of the Hubble diagram. At small redshifts, this is possible without assumptions on the cosmic inventory and provides a fundamental test of the cosmological principle. At higher redshift we check for the self-consistency of the LambdaCDM model. At small redshifts, we use public supernovae (SNe) Ia data to determine the deceleration parameter q_0 and the SN calibration on opposite hemispheres. For the complete data sets we fit Omega_M and the SN calibration on opposite hemispheres. A statistically significant anisotropy of the Hubble diagram at redshifts z 95% C.L.). While data from the North Galactic hemisphere favour the accelerated expansion of the Universe, data from the South Galactic hemisphere are not conclusive. The hemispheric asymmetry is maximal toward a direction close to the equatorial poles. The discrepancy between the equatorial North and South hemispheres shows up in the SN calibration. For the LambdaCDM model fitted to all available SNe, we find the same asymmetry. The alignment of discrepancies between hemispheric Hubble diagrams with the equatorial frame seems to point toward a systematic error in the SN search, observation, analysis or data reduction. We also find that our model independent test cannot exclude the case of the deceleration of the expansion at a statistically significant level.

  12. Alignment of Iron Nanoparticles in a Magnetic Field Due to Shape Anisotropy

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

    Radhakrishnan, Balasubramaniam; Nicholson, Don M; Eisenbach, Markus; Ludtka, Gerard Michael; Rios, Orlando; Parish, Chad M

    2015-07-09

    During high magnetic field processing there is evidence for alignment of non-spherical metallic particles above the Curie temperature in alloys with negligible magneto-crystalline anisotropy. The main driving force for alignment is the magnetic shape anisotropy. Current understanding of the phenomenon is not adequate to quantify the effect of particle size, aspect ratio, temperature and the magnetic field on particle alignment. We demonstrate a Monte Carlo approach coupled with size scaling to show the conditions under which alignment is possible.

  13. Large-scale anisotropy of TeV-band cosmic rays

    SciTech Connect (OSTI)

    Kumar, Rahul; Eichler, David [Phyiscs Department, Ben-Gurion University, Be'er-Sheba 84105 (Israel)

    2014-04-20

    The expected anisotropy in the 1 to 10{sup 4} TeV energy range is calculated for Galactic cosmic rays with both anisotropy in the diffusion tensor and source discreteness taken into account. We find that if the sources are distributed radially (but with azimuthal symmetry) in proportion to Galactic pulsars, the expected anisotropy almost always exceeds the observational limits by one order of magnitude in the case of isotropic diffusion. If the radial diffusion is more than an order of magnitude smaller than the azimuthal diffusion rate, the radial gradient of the sources can be accommodated about 5% of the time. If the sources are concentrated in the spiral arms, then the anisotropy depends on our location between them, but in some spatial window, roughly equidistant from adjacent spiral arms, the observational constraints on anisotropy are obeyed roughly 20%-30% of the time for extremely anisotropic diffusion. The solar system is in that window less than 10% of the time, but it may be there now. Under the assumption of isotropic diffusion, nearby supernovae are found to produce a discreteness anisotropy that is nearly two orders of magnitude in excess of the observational limit if all supernovae are assumed to contribute equally with a source rate 1 in every 100 years.

  14. Fermi-LAT ?-ray anisotropy and intensity explained by unresolved radio-loud active galactic nuclei

    SciTech Connect (OSTI)

    Mauro, Mattia Di; Cuoco, Alessandro; Donato, Fiorenza [Dipartimento di Fisica, Università di Torino, via P. Giuria 1, Torino, 10125 Italy (Italy); Siegal-Gaskins, Jennifer M., E-mail: mattia.dimauro@to.infn.it, E-mail: alessandro.cuoco@to.infn.it, E-mail: donato@to.infn.it, E-mail: jsg@tapir.caltech.edu [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, 91125 (United States)

    2014-11-01

    Radio-loud active galactic nuclei (AGN) are expected to contribute substantially to both the intensity and anisotropy of the isotropic ?-ray background (IGRB). In turn, the measured properties of the IGRB can be used to constrain the characteristics of proposed contributing source classes. We consider individual subclasses of radio-loud AGN, including low-, intermediate-, and high-synchrotron-peaked BL Lacertae objects, flat-spectrum radio quasars, and misaligned AGN. Using updated models of the ?-ray luminosity functions of these populations, we evaluate the energy-dependent contribution of each source class to the intensity and anisotropy of the IGRB. We find that collectively radio-loud AGN can account for the entirety of the IGRB intensity and anisotropy as measured by the Fermi Large Area Telescope (LAT). Misaligned AGN provide the bulk of the measured intensity but a negligible contribution to the anisotropy, while high-synchrotron-peaked BL Lacertae objects provide the dominant contribution to the anisotropy. In anticipation of upcoming measurements with the Fermi-LAT and the forthcoming Cherenkov Telescope Array, we predict the anisotropy in the broader energy range that will be accessible to future observations.

  15. A robust absorbing layer method for anisotropic seismic wave modeling

    SciTech Connect (OSTI)

    Métivier, L.; Brossier, R.; Labbé, S.; Operto, S.; Virieux, J.

    2014-12-15

    When applied to wave propagation modeling in anisotropic media, Perfectly Matched Layers (PML) exhibit instabilities. Incoming waves are amplified instead of being absorbed. Overcoming this difficulty is crucial as in many seismic imaging applications, accounting accurately for the subsurface anisotropy is mandatory. In this study, we present the SMART layer method as an alternative to PML approach. This method is based on the decomposition of the wavefield into components propagating inward and outward the domain of interest. Only outgoing components are damped. We show that for elastic and acoustic wave propagation in Transverse Isotropic media, the SMART layer is unconditionally dissipative: no amplification of the wavefield is possible. The SMART layers are not perfectly matched, therefore less accurate than conventional PML. However, a reasonable increase of the layer size yields an accuracy similar to PML. Finally, we illustrate that the selective damping strategy on which is based the SMART method can prevent the generation of spurious S-waves by embedding the source in a small zone where only S-waves are damped.

  16. Properties of Flares-Generated Seismic Waves on the Sun

    E-Print Network [OSTI]

    A. G. Kosovichev

    2005-12-31

    The solar seismic waves excited by solar flares (``sunquakes'') are observed as circular expanding waves on the Sun's surface. The first sunquake was observed for a flare of July 9, 1996, from the Solar and Heliospheric Observatory (SOHO) space mission. However, when the new solar cycle started in 1997, the observations of solar flares from SOHO did not show the seismic waves, similar to the 1996 event, even for large X-class flares during the solar maximum in 2000-2002. The first evidence of the seismic flare signal in this solar cycle was obtained for the 2003 ``Halloween'' events, through acoustic ``egression power'' by Donea and Lindsey. After these several other strong sunquakes have been observed. Here, I present a detailed analysis of the basic properties of the helioseismic waves generated by three solar flares in 2003-2005. For two of these flares, X17 flare of October 28, 2003, and X1.2 flare of January 15, 2005, the helioseismology observations are compared with simultaneous observations of flare X-ray fluxes measured from the RHESSI satellite. These observations show a close association between the flare seismic waves and the hard X-ray source, indicating that high-energy electrons accelerated during the flare impulsive phase produced strong compression waves in the photosphere, causing the sunquake. The results also reveal new physical properties such as strong anisotropy of the seismic waves, the amplitude of which varies significantly with the direction of propagation. The waves travel through surrounding sunspot regions to large distances, up to 120 Mm, without significant decay. These observations open new perspectives for helioseismic diagnostics of flaring active regions on the Sun and for understanding the mechanisms of the energy release and transport in solar flares.

  17. Relativistic Quaternionic Wave Equation II

    E-Print Network [OSTI]

    Schwartz, Charles

    2007-01-01

    Relativistic quaternionic wave equation. II J. Math. Phys.Relativistic quaternionic wave equation. II Charles Schwartzcomponent quaternionic wave equation recently introduced. A

  18. Rogue Wave Modes for the Long Wave-Short Wave Resonance Kwok Wing CHOW*(1)

    E-Print Network [OSTI]

    1 Rogue Wave Modes for the Long Wave-Short Wave Resonance Model Kwok Wing CHOW*(1) , Hiu Ning CHAN.45.Yv; 47.35.Fg ABSTRACT The long wave-short wave resonance model arises physically when the phase velocity of a long wave matches the group velocity of a short wave. It is a system of nonlinear evolution

  19. Rogue Wave Modes for the Long WaveShort Wave Resonance Model Kwok Wing CHOW

    E-Print Network [OSTI]

    Rogue Wave Modes for the Long Wave­Short Wave Resonance Model Kwok Wing CHOW 1Ã , Hiu Ning CHAN 1 online June 11, 2013) The long wave­short wave resonance model arises physically when the phase velocity of a long wave matches the group velocity of a short wave. It is a system of nonlinear evolution equations

  20. Rogue Wave Modes for the Long Wave-Short Wave Resonance Kwok Wing CHOW*(1)

    E-Print Network [OSTI]

    of a long wave matches the group velocity of a short wave. Significant interactions and energy transfer can1 Rogue Wave Modes for the Long Wave-Short Wave Resonance Model Kwok Wing CHOW*(1) , Hiu Ning CHAN.45.Yv; 47.35.Fg ABSTRACT The long wave-short wave resonance model arises physically when the phase

  1. Phase-controllable spin wave generation in iron garnet by linearly polarized light pulses

    SciTech Connect (OSTI)

    Yoshimine, Isao; Iida, Ryugo; Shimura, Tsutomu; Satoh, Takuya; Stupakiewicz, Andrzej; Maziewski, Andrzej

    2014-07-28

    A phase-controlled spin wave was non-thermally generated in bismuth-doped rare-earth iron garnet by linearly polarized light pulses. We controlled the initial phase of the spin wave continuously within a range of 180° by changing the polarization azimuth of the excitation light. The azimuth dependences of the initial phase and amplitude of the spin wave were attributed to a combination of the inverse Cotton-Mouton effect and photoinduced magnetic anisotropy. Temporally and spatially resolved spin wave propagation was observed with a CCD camera, and the waveform was in good agreement with calculations. A nonlinear effect of the spin excitation was observed for excitation fluences higher than 100 mJ/cm{sup 2}.

  2. Propagation of polarized light in opals: Amplitude and phase anisotropy

    SciTech Connect (OSTI)

    Baryshev, A. V. Dokukin, M. E.; Merzlikin, A. M.; Inoue, M.

    2011-03-15

    The interaction of linearly polarized light with photonic crystals based on bulk and thin-film synthetic opals is studied. Experimental transmission spectra and spectra showing the polarization state of light transmitted through opals are discussed. A change in polarization is found for waves experiencing Bragg diffraction from systems of crystallographic planes of the opal lattice. It is shown that the polarization plane of the incident linearly polarized wave at the exit from photonic crystals can be considerably rotated. In addition, incident linearly polarized light can be transformed to elliptically polarized light with the turned major axis of the polarization ellipse. Analysis of polarization states of transmitted light by using the transfer-matrix theory and homogenization theory revealed good agreement between calculated and experimental spectra.

  3. Internal Wave Interferometry

    E-Print Network [OSTI]

    Mathur, Manikandan S.

    Internal waves are a ubiquitous and significant means of momentum and energy transport in the oceans, atmosphere, and astrophysical bodies. Here, we show that internal wave propagation in nonuniform density stratifications, ...

  4. New wave generation

    E-Print Network [OSTI]

    Mercier, Matthieu J.

    We present the results of a combined experimental and numerical study of the generation of internal waves using the novel internal wave generator design of Gostiaux et al. (Exp. Fluids, vol. 42, 2007, pp. 123–130). This ...

  5. Thermodynamic and Kinetic Anisotropies in Octane Thin Films

    E-Print Network [OSTI]

    Amir Haji-Akbari; Pablo G. Debenedetti

    2015-09-25

    Confinement breaks the translational symmetry of materials. Such symmetry breaking can be used to obtain configurations that are not otherwise accessible in the bulk. Here, we explore the effect of substrate-liquid interactions on the induced thermodynamic and kinetic anisotropies. We consider n-octane nanofilms that are in contact with substrates with varying degrees of attraction. Complete freezing of octane nanofilms is observed at low temperatures, while at intermediate temperatures, a frozen monolayer emerges at both interfaces. By carefully inspecting the profiles of translational and orientational relaxation times, we confirm that the translational and orientational degrees of freedom are decoupled at these frozen monolayers. At sufficiently high temperatures, however, free interfaces and solid-liquid interfaces close to loose substrates undergo pre-freezing, characterized by mild peaks in several thermodynamic quantities. Two distinct dynamic regimes are observed. The dynamics is accelerated in the vicinity of loose substrates, while sticky substrates decelerate dynamics, sometimes by as much as two orders of magnitude. These two distinct dynamical regimes have been previously by us [JCP 141: 024506, 2014] for a model atomic glass-forming liquid. We also confirm the existence of two correlations proposed in the above-mentioned work in solid-liquid subsurface regions of octane films, i.e., a correlation between density and normal stress, and between atomic translational relaxation time and lateral stress. Finally, we inspect the ability of different regions of a film to explore the potential energy landscape, and observe no noticeable difference between the free surface and the bulk. This is unlike the films of model atomic glass formers that tend to sample their respective landscape more efficiently at free surfaces.

  6. Gravitational Waves on Conductors

    E-Print Network [OSTI]

    A. Lewis Licht

    2004-03-12

    We consider a gravitational wave of arbitrary frequency incident on a normal or a super-conductor. The gravitationally induced fields inside the conductor are derived. The outward propagating EM waves are calculated for a low frequency wave on a small sphere and for a high frequency wave incident on a large disk. We estimate for both targets the GW to EM conversion efficiencies and also the magnitude of the superconductor's phase perturbation.

  7. Bragg grating rogue wave

    E-Print Network [OSTI]

    Degasperis, Antonio; Aceves, Alejandro B

    2015-01-01

    We derive the rogue wave solution of the classical massive Thirring model, that describes nonlinear optical pulse propagation in Bragg gratings. Combining electromagnetically induced transparency with Bragg scattering four-wave mixing, may lead to extreme waves at extremely low powers.

  8. Wave Particles Cem Yuksel

    E-Print Network [OSTI]

    Keyser, John

    Wave Particles Cem Yuksel Computer Science Texas A&M University Donald H. House Visualization captured from our real-time simulation system (approximately 100,000 wave particles) Abstract We present a new method for the real-time simulation of fluid sur- face waves and their interactions with floating

  9. Internal wave instability: Wave-wave versus wave-induced mean flow interactions

    E-Print Network [OSTI]

    Sutherland, Bruce

    , known as parametric sub- harmonic instability, results generally when a disturbance of one frequency imparts energy to disturbances of half that frequency.13,14 Generally, a plane periodic internal wave, energy from primary waves is transferred, for example, to waves with half frequency. Self

  10. Whistler anisotropy instabilities as the source of banded chorus: Van Allen Probes observations and particle-in-cell simulations: FU ET AL.

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

    Fu, Xiangrong; Cowee, Misa M.; Friedel, Reinhard H.; Funsten, Herbert O.; Gary, S. Peter; Hospodarsky, George B.; Kletzing, Craig; Kurth, William; Larsen, Brian A.; Liu, Kaijun; et al

    2014-10-22

    Magnetospheric banded chorus is enhanced whistler waves with frequencies ?rmore »November 2012. The observations are consistent with a three-component electron model consisting of a cold (a few tens of eV) population, a warm (a few hundred eV) anisotropic population, and a hot (a few keV) anisotropic population. The simulations use plasma and field parameters as measured from the satellite during this event except for two numbers: the anisotropies of the warm and the hot electron components are enhanced over the measured values in order to obtain relatively rapid instability growth. The simulations show that the warm component drives the quasi-electrostatic upper band chorus and that the hot component drives the electromagnetic lower band chorus; the gap at ??e/2 is a natural consequence of the growth of two whistler modes with different properties.« less

  11. Performance Assessment of the Wave Dragon Wave Energy Converter

    E-Print Network [OSTI]

    Hansen, René Rydhof

    Performance Assessment of the Wave Dragon Wave Energy Converter Based on the EquiMar Methodology S of the wave energy sector, device developers are called to provide reliable estimates on power performanceMar, Nissum Bredning, Hanstholm, North Sea, Ekofisk, Wave-to-wire, Wave energy. I. INTRODUCTION The wave

  12. Monte Carlo determination of the low-energy constants of a spin-(1/2) Heisenberg model with spatial anisotropy

    SciTech Connect (OSTI)

    Jiang, F.-J.; Nyfeler, M.; Kaempfer, F.

    2009-07-15

    Motivated by the possible mechanism for the pinning of the electronic liquid crystal direction in YBa{sub 2}Cu{sub 3}O{sub 6.45} as proposed by Pardini et al. [Phys. Rev. B 78, 024439 (2008)], we use the first-principles Monte Carlo method to study the spin-(1/2) Heisenberg model with antiferromagnetic couplings J{sub 1} and J{sub 2} on the square lattice. In particular, the low-energy constants spin stiffness {rho}{sub s}, staggered magnetization M{sub s}, and spin wave velocity c are determined by fitting the Monte Carlo data to the predictions of magnon chiral perturbation theory. Further, the spin stiffnesses {rho}{sub s1} and {rho}{sub s2} as a function of the ratio J{sub 2}/J{sub 1} of the couplings are investigated in detail. Although we find a good agreement between our results with those obtained by the series expansion method in the weakly anisotropic regime, for strong anisotropy we observe discrepancies.

  13. Coastal Wave Generation and Wave Breaking over Terrain: Two Problems in Mesoscale Wave Dynamics 

    E-Print Network [OSTI]

    Qian, Tingting

    2010-07-14

    Two problems in mesoscale wave dynamics are addressed: (i) wave-turbulence interaction in a breaking mountain wave and (ii) gravity wave generation associated with coastal heating gradients. The mean and turbulent structures in a breaking mountain...

  14. Magnetic fields and cosmic ray anisotropies at TeV energies

    E-Print Network [OSTI]

    Eduardo Battaner; Joaquin Castellano; Manuel Masip

    2014-12-20

    Several cosmic-ray observatories have provided a high accuracy map of the sky at TeV--PeV energies. The data reveals an O(0.1%) deficit from north galactic directions that peaks at 10 TeV and then evolves with the energy, together with other anisotropies at smaller angular scales. Using Boltzmann's equation we derive expressions for the cosmic-ray flux that fit most of these features. The anisotropies depend on the local interstellar magnetic field B_{IS}, on the average galactic field B_{R} in our vicinity, and on the distribution of dominant cosmic-ray sources. We show that the initial dipole anisotropy along B_{IS} can be modulated by changes in the global cosmic ray wind, and that a variation in the dipole direction would imply a given radius of coherence for B_{IS}. We also show that small and medium-scale anisotropies may appear when the full-sky anisotropy finds a turbulence acting as a magnetic lens.

  15. Cycloidal Wave Energy Converter

    SciTech Connect (OSTI)

    Stefan G. Siegel, Ph.D.

    2012-11-30

    This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.

  16. Exchange coupling in hybrid anisotropy magnetic multilayers quantified by vector magnetometry

    SciTech Connect (OSTI)

    Morrison, C. Miles, J. J.; Thomson, T.; Anh Nguyen, T. N.; Fang, Y.; Dumas, R. K.; Åkerman, J.

    2015-05-07

    Hybrid anisotropy thin film heterostructures, where layers with perpendicular and in-plane anisotropy are separated by a thin spacer, are novel materials for zero/low field spin torque oscillators and bit patterned media. Here, we report on magnetization reversal and exchange coupling in a archetypal Co/Pd (perpendicular)-NiFe (in-plane) hybrid anisotropy system studied using vector vibrating sample magnetometry. This technique allows us to quantify the magnetization reversal in each individual magnetic layer, and measure of the interlayer exchange as a function of non-magnetic spacer thickness. At large (>1?nm) spacer thicknesses Ruderman-Kittel-Kasuya-Yosida-like exchange dominates, with orange-peel coupling providing a significant contribution only for sub-nm spacer thickness.

  17. Structural controlled magnetic anisotropy in Heusler L1{sub 0}-MnGa epitaxial thin films

    SciTech Connect (OSTI)

    Wang Kangkang; Lu Erdong; Smith, Arthur R.; Knepper, Jacob W.; Yang Fengyuan

    2011-04-18

    Ferromagnetic L1{sub 0}-MnGa thin films have been epitaxially grown on GaN, sapphire, and MgO substrates using molecular beam epitaxy. Using diffraction techniques, the epitaxial relationships are determined. It is found that the crystalline orientation of the films differ due to the influence of the substrate. By comparing the magnetic anisotropy to the structural properties, a clear correlation could be established indicating that the in-plane and out-of-plane anisotropy is directly determined by the crystal orientation of the film and could be controlled via selection of the substrates. This result could be helpful in tailoring magnetic anisotropy in thin films for spintronic applications.

  18. Anisotropy enhancement of the Casimir-Polder force between a nanoparticle and graphene

    E-Print Network [OSTI]

    Svend-Age Biehs; Girish S. Agarwal

    2015-03-27

    We derive the analytical expressions for the thermal Casimir-Polder energy and force between a spheroidal nanoparticle above a semi-infinite material and a graphene covered interface. We analyze in detail the Casimir-Polder force between a gold nanoparticle and a single sheet of pristine graphene focusing on the impact of anisotropy. We show that the effect of anisotropy, i.e. the shape and orientation of the spheroidal nanoparticle, has a much larger influence on the force than the tunability of graphene. The effect of tuning and anisotropy both add up such that we observe a force which is between 20-50% of that in the ideal metal case which is much larger than the results found for the Casimir force between a metal halfspace and a layer of graphene.

  19. Environment-induced anisotropy and the sensitivity of the radical pair mechanism in the avian compass

    E-Print Network [OSTI]

    Alejandro Carrillo; Marcio F. Cornelio; Marcos C. de Oliveira

    2015-08-07

    Several experiments over the years have shown that the Earth's magnetic field is essential for orientation in birds migration. The most promising explanation for this orientation is the photo-stimulated radical pair (RP) mechanism. In order to define a reference frame for the orientation task radicals must have an intrinsic anisotropy. We show that this kind of anisotropy, and consequently the entanglement in the model, are not necessary for the proper functioning of the compass. Classically correlated initial conditions for the RP, subjected to a fast decoherence process, are able to provide the anisotropy required. Even a dephasing environment can provide the necessary frame for the compass to work, and also implies fast decay of any quantum correlation in the system without damaging the orientation ability. This fact significantly expands the range of applicability of the RP mechanism providing more elements for experimental search.

  20. Observation of Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC

    E-Print Network [OSTI]

    BenZvi, S Y; Westerhoff, S

    2015-01-01

    The High-Altitude Water Cherenkov (HAWC) Observatory, located 4100 m above sea level near Sierra Negra (19$^\\circ$ N) in Mexico, is sensitive to gamma rays and cosmic rays at TeV energies. The arrival direction distribution of cosmic rays at these energies shows significant anisotropy on several angular scales, with a relative intensity ranging between 10$^{-3}$ and 10$^{-4}$. We present the results of a study of cosmic-ray anisotropy based on more than 86 billion cosmic-ray air showers recorded with HAWC since June 2013. The HAWC cosmic-ray sky map, which has a median energy of 2 TeV, exhibits several regions of significantly enhanced cosmic-ray flux. We present the energy dependence of the anisotropy and the cosmic-ray spectrum in the regions of significant excess.

  1. Spin-fluctuation mechanism of anomalous temperature dependence of magnetocrystalline anisotropy in itinerant magnets

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

    Zhuravlev, I. A.; Antropov, V. P.; Belashchenko, K. D.

    2015-11-16

    The origins of the anomalous temperature dependence of magnetocrystalline anisotropy in (Fe1–xCox)2B alloys are elucidated using first-principles calculations within the disordered local moment model. Excellent agreement with experimental data is obtained. The anomalies are associated with the changes in band occupations due to Stoner-like band shifts and with the selective suppression of spin-orbit “hot spots” by thermal spin fluctuations. Under certain conditions, the anisotropy can increase, rather than decrease, with decreasing magnetization. This peculiar electronic mechanisms is in stark contrast to the assumptions of the existing models.

  2. Power spectrum and anisotropy of super inflation in loop quantum cosmology

    E-Print Network [OSTI]

    Xiao-Jun Yue; Jian-Yang Zhu

    2013-03-25

    We investigate the scalar mode of perturbation of super inflation in the version of loop quantum cosmology in which the gauge invariant holonomy corrections are considered. Given a background solution, we calculate the power spectrum of the perturbation in the classical and LQC conditions. Then we compute the anisotropy originated from the perturbation. It is found that in the presence of the gauge invariant holonomy corrections the power spectrum is exponentially blue and the anisotropy also grows exponentially in the epoch of super inflation.

  3. Momentum anisotropies in the quark coalescence model RID A-2398-2009 

    E-Print Network [OSTI]

    Kolb, PF; Chen, LW; Greco, V.; Ko, Che Ming.

    2004-01-01

    experimentally accessible. The experimental data further indicate that there is a scaling relation among the hadronic anisotropy coeffi- cients vn, i.e., vnspTd,1.2v2n/2spTd. To gain insight in the ori- gin of this scaling relation, we relate in the present... of the parton transverse mo- mentum spectra to the third power, i.e., F? swd ~ fswd3 ~ 1 + 2o n=1 ` V?n cos nw . s5d The calculations given in the Appendix then lead to a some- what more complicated expression for the nth order baryon anisotropy V?n, V...

  4. Magnetic anisotropy engineering: Single-crystalline Fe films on ion eroded ripple surfaces

    SciTech Connect (OSTI)

    Liedke, M. O.; Koerner, M.; Lenz, K.; Grossmann, F.; Facsko, S.; Fassbender, J.

    2012-06-11

    We present a method to preselect the direction of an induced in-plane uniaxial magnetic anisotropy (UMA) in thin single-crystalline Fe films on MgO(001). Ion beam irradiation is used to modulate the MgO(001) surface with periodic ripples on the nanoscale. The ripple direction determines the orientation of the UMA, whereas the intrinsic cubic anisotropy of the Fe film is not affected. Thus, it is possible to superimpose an in-plane UMA with a precision of a few degrees - a level of control not reported so far that can be relevant for example in spintronics.

  5. OBSERVATION OF COSMIC-RAY ANISOTROPY WITH THE ICETOP AIR SHOWER ARRAY

    E-Print Network [OSTI]

    Aartsen, M. G.; Besson, David Zeke

    2013-02-15

    The Astrophysical Journal, 765:55 (9pp), 2013 March 1 doi:10.1088/0004-637X/765/1/55 C© 2013. The American Astronomical Society. All rights reserved. Printed in the U.S.A. OBSERVATION OF COSMIC-RAY ANISOTROPY WITH THE ICETOP AIR SHOWER ARRAY M. G...; accepted 2012 December 16; published 2013 February 15 ABSTRACT We report on the observation of anisotropy in the arrival direction distribution of cosmic rays at PeV energies. The analysis is based on data taken between 2009 and 2012 with the IceTop air...

  6. Maskelynite formation via solid-state transformation: Evidence of infrared and x-ray anisotropy

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

    Jaret, Steven J.; Ehm, Lars; Woerner, William R.; Phillips, Brian L.; Nekvasil, Hanna; Wright, Shawn P.; Glotch, Timothy D.

    2015-03-24

    We present optical microscopy, micro-Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, high-energy X-ray total scattering experiments, and micro-Fourier transform infrared (micro-FTIR) spectroscopy on shocked labradorite from the Lonar Crater, India. We show that maskelynite of shock class 2 is structurally more similar to fused glass than to crystalline plagioclase. However, there are slight but significant differences – preservation of original pre-impact igneous zoning, anisotropy at Infrared wavelengths, X-ray anisotropy, and preservation of some intermediate range order – which are all consistent with a solid-state transformation formation of maskelynite.

  7. MHD waves in sunspots

    E-Print Network [OSTI]

    Sych, Robert

    2015-01-01

    The review addresses the spatial frequency morphology of sources of sunspot oscillations and waves, including their localization, size, oscillation periods, height localization with the mechanism of cut-off frequency that forms the observed emission variability. Dynamic of sunspot wave processes, provides the information about the structure of wave fronts and their time variations, investigates the oscillation frequency transformation depending on the wave energy is shown. The initializing solar flares caused by trigger agents like magnetoacoustic waves, accelerated particle beams, and shocks are discussed. Special attention is paid to the relation between the flare reconnection periodic initialization and the dynamics of sunspot slow magnetoacoustic waves. A short review of theoretical models of sunspot oscillations is provided.

  8. Pump-Probe Polarization Anisotropy Study of Femtosecond Energy Transfer within the Photosynthetic Reaction Center of Rhodobacter sphaeroides R26

    E-Print Network [OSTI]

    Lang, Matthew

    Pump-Probe Polarization Anisotropy Study of Femtosecond Energy Transfer within the Photosynthetic) in the photosynthetic reaction center has been time resolved with pump-probe polarization anisotropy measurements using artifacts from saturation and photoexcitation of incompletely relaxed reaction centers. The pump excitation

  9. Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino

    E-Print Network [OSTI]

    Merlino, Robert L.

    Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino Department of Physics and Astronomy and experimental work on dust acoustic waves is given. The basic physics of the dust acoustic wave and some findings and outstanding problems are also presented. Keywords: dusty plasmas, dust acoustic waves PACS: 52

  10. Wave momentum flux parameter: a descriptor for nearshore waves

    E-Print Network [OSTI]

    US Army Corps of Engineers

    Wave momentum flux parameter: a descriptor for nearshore waves Steven A. Hughes* US Army Engineer Available online 7 October 2004 Abstract A new parameter representing the maximum depth-integrated wave momentum flux occurring over a wave length is proposed for characterizing the wave contribution

  11. Structure-borne sound Flexural wave (bending wave)

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Structure-borne sound · Flexural wave (bending wave) »One dimensional (beam) +(/x)dx +(/x)dx = (/x) (/x)dx=(2/x2)dx Mz +(Mz/x)dx Mz vy Fy Fy +(Fy/x)dx Structure-borne sound · Bending wave ­ flexural wave #12;2 Structure-borne sound · Two obliquely propagating waves + - + + - + - Structure

  12. REAL-TIME WATER WAVES WITH WAVE PARTICLES

    E-Print Network [OSTI]

    Keyser, John

    REAL-TIME WATER WAVES WITH WAVE PARTICLES A Dissertation by Cem Yuksel Submitted to the Office of DOCTOR OF PHILOSOPHY August 2010 Major Subject: Computer Science #12;REAL-TIME WATER WAVES WITH WAVE, Valerie E. Taylor August 2010 Major Subject: Computer Science #12;iii ABSTRACT Real-time Water Waves

  13. GN Wave theory and TEBEM for Wave-Body Interaction

    E-Print Network [OSTI]

    GN Wave theory and TEBEM for Wave-Body Interaction Dr. BinBin Zhao and Professor Wenyang Duan of simulating irregular nonlinear water wave interaction with arbitrary floating bodies, the Green-Naghdi wave corners. The results show that the high-level GN theory can predict wave transformation over uneven seabed

  14. Trimodal steady water waves

    E-Print Network [OSTI]

    Mats Ehrnström; Erik Wahlén

    2013-10-31

    We construct three-dimensional families of small-amplitude gravity-driven rotational steady water waves on finite depth. The solutions contain counter-currents and multiple crests in each minimal period. Each such wave generically is a combination of three different Fourier modes, giving rise to a rich and complex variety of wave patterns. The bifurcation argument is based on a blow-up technique, taking advantage of three parameters associated with the vorticity distribution, the strength of the background stream, and the period of the wave.

  15. Directed Relativistic Blast Wave

    E-Print Network [OSTI]

    Andrei Gruzinov

    2007-04-23

    A spherically symmetrical ultra-relativistic blast wave is not an attractor of a generic asymmetric explosion. Spherical symmetry is reached only by the time the blast wave slows down to non-relativistic velocities, when the Sedov-Taylor-von Neumann attractor solution sets in. We show however, that a directed relativistic explosion, with the explosion momentum close to the explosion energy, produces a blast wave with a universal intermediate asymptotic -- a selfsimilar directed ultra-relativistic blast wave. This universality might be of interest for the astrophysics of gamma-ray burst afterglows.

  16. Characterizing Fractures in the Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy

    Broader source: Energy.gov [DOE]

    Determine if fracturing could be used to enhance permeability; and whether dilution of existing fluids with injected water would lower corrosivity enough to allow economic production of power.

  17. Characterizing Fractures in Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy

    SciTech Connect (OSTI)

    Aminzadeh, Fred; Sammis, Charles; Sahimi, Mohammad; Okaya, David

    2015-04-30

    The ultimate objective of the project was to develop new methodologies to characterize the northwestern part of The Geysers geothermal reservoir (Sonoma County, California). The goal is to gain a better knowledge of the reservoir porosity, permeability, fracture size, fracture spacing, reservoir discontinuities (leaky barriers) and impermeable boundaries.

  18. Shear-wave splitting, lithospheric anisotropy, and mantle deformation beneath the ArabiaEurasia collision zone in Iran

    E-Print Network [OSTI]

    Hatzfeld, Denis

    ­Eurasia collision zone in Iran Ayoub Kaviani a,b,c , Denis Hatzfeld c, , Anne Paul c , Mohammad Tatar b , Keith Priestley d a Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, Zanjan, Iran b International Institute of Earthquake Engineering and Seismology, P.O. Box 19395-3913, Tehran, Iran c

  19. Wave Energy challenges and possibilities

    E-Print Network [OSTI]

    © Wave Energy ­ challenges and possibilities By: Per Resen Steenstrup www.WaveStarEnergy.com Risø-R-1608(EN) 161 #12;© Wave energy is an old story.... The first wave energy patent is 200 years old. Over the last 100 years more than 200 new wave energy devices have been developped and more than 1.000 patents

  20. Wave Energy Resource Analysis for Use in Wave Energy Conversion 

    E-Print Network [OSTI]

    Pastor, J.; Liu, Y.; Dou, Y.

    2014-01-01

    In order to predict the response of wave energy converters an accurate representation of the wave climate resource is crucial. This paper gives an overview of wave resource modeling techniques as well as detailing a methodology for estimating...

  1. Wave-Corpuscle Mechanics for Electric Charges

    E-Print Network [OSTI]

    Babin, Anatoli; Figotin, Alexander

    2010-01-01

    superposition in nonlinear wave dynamics. Rev. Math. Phys.6. Babin, A. , Figotin, A. : Wave-corpuscle mechanics forV. , Fortunato, D. : Solitary waves in the nonlinear wave

  2. Microstructural Design for Stress Wave Energy Management /

    E-Print Network [OSTI]

    Tehranian, Aref

    2013-01-01

    Nasser, S. , 2010. Stress-wave energy management throughNemat-Nasser, Stress-wave energy management through materialconstitute pressure wave energy and/or shear wave energy.

  3. Magnetic anisotropy of permalloy films grown on an Mo,,001... stepped surface

    E-Print Network [OSTI]

    Huang, Jung-Chun

    , low coercivity, and small magnetic anisotropy.1 Py based multilayers2,3 and spin-valve4,5 struc- tures was below 5 10 9 torr. One-side polished Al2O3 1-102 sub- strates were outgassed at 1000 °C for 1 h prior

  4. Three-dimensional analyses of electric currents and pressure anisotropies in the plasma sheet

    E-Print Network [OSTI]

    Kaufmann, Richard L.

    Richard L. Kaufmann and Chen Lu Department of Physics, University of New Hampshire, Durham, New HampshireThree-dimensional analyses of electric currents and pressure anisotropies in the plasma sheet is compared with a new more comprehensive procedure. Good agreement between the two methods was found when

  5. Permeability of illite-bearing shale: 1. Anisotropy and effects of clay content and loading

    E-Print Network [OSTI]

    Herbert, Bruce

    Permeability of illite-bearing shale: 1. Anisotropy and effects of clay content and loading-rich shale recovered from the Wilcox formation and saturated with 1 M NaCl solution varies from 3 Â 10À22 transport; KEYWORDS: permeability, shale, connected pore space Citation: Kwon, O., A. K. Kronenberg, A. F

  6. Scaling anisotropy of the power in parallel and perpendicular components of the solar wind magnetic field

    E-Print Network [OSTI]

    Oughton, Sean

    Scaling anisotropy of the power in parallel and perpendicular components of the solar wind magnetic of the Power in Parallel and Perpendicular Components of the Solar Wind Magnetic Field Miriam A. Forman1 ZLWK GLVWDQFH IURP WKH 6XQ 7KLV GDWD LQFOXGHV WKH VRlar wind whose total power (Pxx + Pyy + Pzz#12; LQ

  7. PUBLISHED ONLINE: 6 OCTOBER 2013 | DOI: 10.1038/NPHYS2766 Spintronic magnetic anisotropy

    E-Print Network [OSTI]

    Loss, Daniel

    ARTICLES PUBLISHED ONLINE: 6 OCTOBER 2013 | DOI: 10.1038/NPHYS2766 Spintronic magnetic anisotropy to ferromagnets, a quadrupolar spintronic exchange field is generated locally. It is observable by means. Analogously to the spintronic dipolar exchange field, giving rise to a local spin torque, the effect

  8. Wind/SWE observations of firehose constraint on solar wind proton temperature anisotropy

    E-Print Network [OSTI]

    Richardson, John

    Wind/SWE observations of firehose constraint on solar wind proton temperature anisotropy Justin C the Wind spacecraft are reported here. These measurements show for the first time with a comprehensive plasma and magnetic field data set that this constraint is statistically satisfied in the solar wind near

  9. Dislocation reactions, plastic anisotropy and forest strengthening in MgO at high temperature

    E-Print Network [OSTI]

    Devincre, Benoit

    Dislocation reactions, plastic anisotropy and forest strengthening in MgO at high temperature J 2013 Available online 18 January 2014 Keywords: MgO Plasticity Dislocation Dynamics simulation Forest by forest reactions. Impor- tant parameters for dislocation density based modeling of MgO plasticity

  10. Effect of permeability anisotropy on buoyancy-driven flow for CO2 sequestration in saline aquifers

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    ) in deep saline aquifers is considered one of the most effective methods for carbon sequestration., 48, W09539, doi:10.1029/2012WR011939.* 1. Introduction [2] Carbon sequestration in deep salineEffect of permeability anisotropy on buoyancy-driven flow for CO2 sequestration in saline aquifers

  11. The Large Scale Cosmic-Ray Anisotropy as Observed with Milagro

    E-Print Network [OSTI]

    A. A. Abdo; B. T. Allen; T. Aune; D. Berley; S. Casanova; C. Chen; B. L. Dingus; R. W. Ellsworth; L. Fleysher; R. Fleysher; M. M. Gonzalez; J. A. Goodman; C. M. Hoffman; B. Hopper; P. H. Hüntemeyer; B. E. Kolterman; C. P. Lansdell; J. T. Linnemann; J. E. McEnery; A. I. Mincer; P. Nemethy; D. Noyes; J. Pretz; J. M. Ryan; P. M. Saz Parkinson; A. Shoup; G. Sinnis; A. J. Smith; G. W. Sullivan; V. Vasileiou; G. P. Walker; D. A. Williams; G. B. Yodh

    2009-04-20

    Results are presented of a harmonic analysis of the large scale cosmic-ray anisotropy as observed by the Milagro observatory. We show a two-dimensional display of the sidereal anisotropy pro jections in right ascension generated by the fitting of three harmonics to 18 separate declination bands. The Milagro observatory is a water Cherenkov detector located in the Jemez mountains near Los Alamos, New Mexico. With a high duty cycle and large field-of-view, Milagro is an excellent instrument for measuring this anisotropy with high sensitivity at TeV energies. The analysis is conducted using a seven year data sample consisting of more than 95 billion events, the largest such data set in existence. We observe an anisotropy with a magnitude around 0.1% for cosmic rays with a median energy of 6 TeV. The dominant feature is a deficit region of depth (2.49 +/- 0.02 stat. +/- 0.09 sys.)x10^(-3) in the direction of the Galactic North Pole centered at 189 degrees right ascension. We observe a steady increase in the magnitude of the signal over seven years.

  12. The Large Scale Cosmic-Ray Anisotropy as Observed with Milagro

    E-Print Network [OSTI]

    Abdo, A A; Aune, T; Berley, D; Casanova, S; Chen, C; Dingus, B L; Ellsworth, R W; Fleysher, L; Fleysher, R; González, M M; Goodman, J A; Hoffman, C M; Hopper, B; Hüntemeyer, P H; Kolterman, B E; Lansdell, C P; Linnemann, J T; McEnery, J E; Mincer, A I; Némethy, P; Noyes, D; Ryan, J M; Parkinson, P M Saz; Shoup, A; Sinnis, G; Smith, A J; Sullivan, G W; Vasileiou, V; Walker, G P; Williams, D A; Yodh, G B

    2008-01-01

    Results are presented of a harmonic analysis of the large scale cosmic-ray anisotropy as observed by the Milagro observatory. We show a two-dimensional display of the sidereal anisotropy projections in right ascension generated by the fitting of three harmonics to 18 separate declination bands. The Milagro observatory is a water Cherenkov detector located in the Jemez mountains near Los Alamos, New Mexico. With a high duty cycle and large field-of-view, Milagro is an excellent instrument for measuring this anisotropy with high sensitivity at TeV energies. The analysis is conducted using a seven year data sample consisting of more than 95 billion events. We observe an anisotropy with a magnitude around 0.1% for cosmic rays with a median energy of 6 TeV. The dominant feature is a deficit region of depth (-2.85 +/- 0.06 stat. +/- 0.08 syst.)x10^(-3) in the direction of the Galactic North Pole with a range in declination of -10 to 45 degrees and 150 to 225 degrees in right ascension. We observe a steady increase ...

  13. Static magnetic solution in magnetic composites with arbitrary susceptibility inhomogeneity and anisotropy

    E-Print Network [OSTI]

    Chen, Long-Qing

    Static magnetic solution in magnetic composites with arbitrary susceptibility inhomogeneity nanoparticles with biaxial anisotropy J. Appl. Phys. 113, 053903 (2013); 10.1063/1.4789848 Static and high://scitation.aip.org/termsconditions. Downloaded to ] IP: 128.118.37.128 On: Fri, 13 Mar 2015 21:15:38 #12;Static magnetic solution in magnetic

  14. Stress magnitude and its temporal variation at Mt. Asama Volcano, Japan, from seismic anisotropy and GPS

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Stress magnitude and its temporal variation at Mt. Asama Volcano, Japan, from seismic anisotropy stress Japan The Earth's stress regime is fundamental to its physical processes, yet few methods can determine absolute stress, and measurements of temporal variations in stress are controversial. The Global

  15. On the Computation of CMBR Anisotropies from Simulations of Topological Defects

    E-Print Network [OSTI]

    Albert Stebbins; Scott Dodelson

    1997-05-21

    Techniques for computing the CMBR anisotropy from simulations of topological defects are discussed with an eye to getting as much information from a simulation as possible. Here we consider the practical details of which sums and multiplications to do and how many terms there are.

  16. Perpendicular magnetic anisotropy in ion beam sputtered Co/Ni multilayers

    E-Print Network [OSTI]

    Rasin, Boris

    2009-01-01

    Co/Ni multilayers display perpendicular magnetic anisotropy and have applications in magnetic devices that could lead to a large increase in the density of magnetic storage. Co/Ni 10-(2 Å Co/ 8Å Ni) and 10-(2 Å Co/ 4 Å Ni) ...

  17. Resistive transition anisotropy in superconducting granular ceramics: Interplay of effective medium approximation and percolation

    E-Print Network [OSTI]

    Strelniker, Yakov M.

    Resistive transition anisotropy in superconducting granular ceramics: Interplay of effective medium directions of the c axis, the current j and the magnetic field H in Bi2Sr2CaCu2O8 x ceramics. We provided in high-Tc superconduct- ing granular ceramics remain an intriguing subject of inten- sive investigations

  18. Angular Anisotropy of Correlated Neutrons in Lab Frame of Reference and Application to Detection and Verification 

    E-Print Network [OSTI]

    Holewa, Laura

    2012-07-16

    emitting the neutrons. Coincident neutrons can be detected from a shielded source, so a study of the angular anisotropy between coincident neutrons is useful for this context. This could allow for the dynamic determination of the ratio of the rate of (alpha...

  19. Wind observations of extreme ion temperature anisotropies in the D. Clack,1,2

    E-Print Network [OSTI]

    Richardson, John

    Wind observations of extreme ion temperature anisotropies in the lunar wake D. Clack,1,2 J. C 2004; accepted 19 February 2004; published 30 March 2004. [1] We describe Wind observations of two of adiabatic invariants as solar wind plasma expands to fill in the cavity behind the Moon. Despite their large

  20. Harmonic generation of gravitational wave induced Alfven waves

    E-Print Network [OSTI]

    Mats Forsberg; Gert Brodin

    2007-11-26

    Here we consider the nonlinear evolution of Alfven waves that have been excited by gravitational waves from merging binary pulsars. We derive a wave equation for strongly nonlinear and dispersive Alfven waves. Due to the weak dispersion of the Alfven waves, significant wave steepening can occur, which in turn implies strong harmonic generation. We find that the harmonic generation is saturated due to dispersive effects, and use this to estimate the resulting spectrum. Finally we discuss the possibility of observing the above process.

  1. Electromagnetic Wave Dynamics in

    E-Print Network [OSTI]

    Kaiser, Robin

    Mesoscopic Electromagnetic Wave Dynamics in Ultracold Atomic Gases Robin Kaiser and Mark D. Havey Mesoscopic Electromagnetic Wave Dynamics in Ultracold Atomic Gases #12;39 E xperimental developments permit in the transport proper- ties of electromagnetic radiation in strongly scattering random media. Even in weakly

  2. CATCHING THE FOURTH WAVE

    E-Print Network [OSTI]

    Bieber, Michael

    CATCHING THE FOURTH WAVE YOU MAY HAVE RIDDEN THEM YOURSELF -- the swells that develop farther out beyond Toffler, the fourth wave -- biologi- cal intelligence and medical technology -- is on the horizon second and fourth nationally in terms of cities that receive the most research funds from the National

  3. Developing de Broglie Wave

    E-Print Network [OSTI]

    J X Zheng-Johansson; P-I Johansson

    2006-08-27

    The electromagnetic component waves, comprising together with their generating oscillatory massless charge a material particle, will be Doppler shifted when the charge hence particle is in motion, with a velocity $v$, as a mere mechanical consequence of the source motion. We illustrate here that two such component waves generated in opposite directions and propagating at speed $c$ between walls in a one-dimensional box, superpose into a traveling beat wave of wavelength ${\\mit\\Lambda}_d$$=(\\frac{v}{c}){\\mit\\Lambda}$ and phase velocity $c^2/v+v$ which resembles directly L. de Broglie's hypothetic phase wave. This phase wave in terms of transporting the particle mass at the speed $v$ and angular frequency ${\\mit\\Omega}_d=2\\pi v /{\\mit\\Lambda}_d$, with ${\\mit\\Lambda}_d$ and ${\\mit\\Omega}_d$ obeying the de Broglie relations, represents a de Broglie wave. The standing-wave function of the de Broglie (phase) wave and its variables for particle dynamics in small geometries are equivalent to the eigen-state solutions to Schr\\"odinger equation of an identical system.

  4. Rayleigh WaveInternal Wave Coupling and Internal Wave Generation Above a Model Jet Stream

    E-Print Network [OSTI]

    Sutherland, Bruce

    Rayleigh Wave­Internal Wave Coupling and Internal Wave Generation Above a Model Jet Stream B. R to the study of unstable jet flows and applications of this work for internal wave generation by dynamic remains poorly understood. Most investigations of shear­generation of inter­ nal waves in the atmosphere

  5. Rayleigh Wave-Internal Wave Coupling and Internal Wave Generation Above a Model Jet Stream

    E-Print Network [OSTI]

    Sutherland, Bruce

    Rayleigh Wave-Internal Wave Coupling and Internal Wave Generation Above a Model Jet Stream B. R to the study of unstable jet flows and applications of this work for internal wave generation by dynamic remains poorly understood. Most investigations of shear-generation of inter- nal waves in the atmosphere

  6. An unsteady wave driver for narrowbanded waves: modeling nearshore circulation driven by wave groups

    E-Print Network [OSTI]

    Kirby, James T.

    An unsteady wave driver for narrowbanded waves: modeling nearshore circulation driven by wave Abstract In this paper, we derive an unsteady refraction­diffraction model for narrowbanded water waves for use in computing coupled wave­current motion in the nearshore. The end result is a variable

  7. Recirculation in multiple wave conversions

    E-Print Network [OSTI]

    Brizard, A.J.

    2008-01-01

    model lies with the simple wave energy conservation law itthe recirculation of wave energy introduces interference e?particles, the tertiary-wave energy may be negative and thus

  8. Center for Wave Phenomena Wave Phenomena

    E-Print Network [OSTI]

    Snieder, Roel

    research and education program in seismic exploration, monitoring and wave propagation. The main focus into a life of scientific discovery." Kurang Mehta, Ph.D. Class of 2007 Shell Exploration and Production Phil of CWP is on seismic modeling, imaging and inversion methods, as well as on improving the accuracy

  9. Diagonalization of pp-waves

    E-Print Network [OSTI]

    B. V. Ivanov

    1997-05-21

    A coordinate transformation is found which diagonalizes the axisymmetric pp-waves. Its effect upon concrete solutions, including impulsive and shock waves, is discussed.

  10. Wave-wave interactions in solar type III radio bursts

    SciTech Connect (OSTI)

    Thejappa, G.; MacDowall, R. J.

    2014-02-11

    The high time resolution observations from the STEREO/WAVES experiment show that in type III radio bursts, the Langmuir waves often occur as localized magnetic field aligned coherent wave packets with durations of a few ms and with peak intensities well exceeding the strong turbulence thresholds. Some of these wave packets show spectral signatures of beam-resonant Langmuir waves, down- and up-shifted sidebands, and ion sound waves, with frequencies, wave numbers, and tricoherences satisfying the resonance conditions of the oscillating two stream instability (four wave interaction). The spectra of a few of these wave packets also contain peaks at f{sub pe}, 2f{sub pe} and 3 f{sub pe} (f{sub pe} is the electron plasma frequency), with frequencies, wave numbers and bicoherences (computed using the wavelet based bispectral analysis techniques) satisfying the resonance conditions of three wave interactions: (1) excitation of second harmonic electromagnetic waves as a result of coalescence of two oppositely propagating Langmuir waves, and (2) excitation of third harmonic electromagnetic waves as a result of coalescence of Langmuir waves with second harmonic electromagnetic waves. The implication of these findings is that the strong turbulence processes play major roles in beam stabilization as well as conversion of Langmuir waves into escaping radiation in type III radio bursts.

  11. Shallow Water Waves and Solitary Waves Willy Hereman

    E-Print Network [OSTI]

    Hereman, Willy A.M.

    . Water Wave Experiments and Observations VII. Future Directions VIII. Bibliography Glossary Deep water A surface wave is said to be in deep water if its wavelength is much shorter than the local water depthShallow Water Waves and Solitary Waves Willy Hereman Department of Mathematical and Computer

  12. Long wave expansions for water waves over random topography

    E-Print Network [OSTI]

    Craig, Walter

    Long wave expansions for water waves over random topography Anne de Bouard1 , Walter Craig2 interacting with the random bottom. We show that the resulting influence of the random topography is expressed numbers: 76B15, 35Q53, 76M50, 60F17 Keywords :Water waves, random topography, long wave asymptotics #12

  13. On Generating Gravity Waves with Matter and Electromagnetic Waves

    E-Print Network [OSTI]

    C. Barrabes; P. A. Hogan

    2008-04-05

    If a homogeneous plane light-like shell collides head-on with a homogeneous plane electromagnetic shock wave having a step-function profile then no backscattered gravitational waves are produced. We demonstrate, by explicit calculation, that if the matter is accompanied by a homogeneous plane electromagnetic shock wave with a step-function profile then backscattered gravitational waves appear after the collision.

  14. Evolution of Rogue Waves in Interacting Wave Systems

    E-Print Network [OSTI]

    A. Grönlund; B. Eliasson; M. Marklund

    2009-04-03

    Large amplitude water waves on deep water has long been known in the sea faring community, and the cause of great concern for, e.g., oil platform constructions. The concept of such freak waves is nowadays, thanks to satellite and radar measurements, well established within the scientific community. There are a number of important models and approaches for the theoretical description of such waves. By analyzing the scaling behavior of freak wave formation in a model of two interacting waves, described by two coupled nonlinear Schroedinger equations, we show that there are two different dynamical scaling behaviors above and below a critical angle theta_c of the direction of the interacting waves below theta_c all wave systems evolve and display statistics similar to a wave system of non-interacting waves. The results equally apply to other systems described by the nonlinear Schroedinger equations, and should be of interest when designing optical wave guides.

  15. LABORATORY VII: WAVE OPTICS

    E-Print Network [OSTI]

    Minnesota, University of

    LABORATORY VII: WAVE OPTICS Lab VII - 1 In this lab, you will solve problems in ways that take-like behavior. These conditions may be less familiar to you than the conditions for which geometrical optics

  16. Traveling-wave photodetector

    DOE Patents [OSTI]

    Hietala, Vincent M. (Placitas, NM); Vawter, Gregory A. (Albuquerque, NM)

    1993-01-01

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.

  17. Surface wave interferometry 

    E-Print Network [OSTI]

    Halliday, David Fraser

    2009-01-01

    This thesis concerns the application of seismic interferometry to surface waves. Seismic interferometry is the process by which the wavefield between two recording locations is estimated, resulting in new recordings at ...

  18. Relativistic quaternionic wave equation

    E-Print Network [OSTI]

    Schwartz, C

    2006-01-01

    Schrodinger ?time dependent? equation, ? 1 and ? 2 , then?TCP?. The current conservation equation ?3.2? is still truefor this extended wave equation ?8.1?, however, Eq. ?6.7?

  19. Traveling-wave photodetector

    DOE Patents [OSTI]

    Hietala, V.M.; Vawter, G.A.

    1993-12-14

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size. 4 figures.

  20. Wave Propagation in Multiferroic Materials

    E-Print Network [OSTI]

    Keller, Scott Macklin

    2013-01-01

    Waves in Magnetoelectric Materials . . . Need forApplication of Multiferroic Materials to Receive AntennaMaterials . . . . . . . . . . . . . . . . . . . . . . . . .

  1. Anisotropy of the electron g factor in quantum wells based on cubic semiconductors

    SciTech Connect (OSTI)

    Alekseev, P. S., E-mail: pavel.alekseev@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2013-09-15

    A new mechanism for the spin splitting of electron levels in asymmetric quantum wells based on GaAs-type semiconductors relative to rotations of the magnetic field in the well plane is suggested. It is demonstrated that the anisotropy of the Zeeman splitting (linear in a magnetic field) arises in asymmetric quantum wells due to the interface spin-orbit terms in the electron Hamiltonian. In the case of symmetric quantum wells, it is shown that the anisotropy of the Zeeman splitting is a cubic function of the magnitude of the magnetic field, depends on the direction of the magnetic field in the interface plane as the fourth-order harmonic, and is governed by the spin-orbit term of the fourth order by the kinematic momentum in the electron Hamiltonian of a bulk semiconductor.

  2. Anisotropic parton escape is the dominant source of azimuthal anisotropy in transport models

    E-Print Network [OSTI]

    Liang He; Terrence Edmonds; Zi-Wei Lin; Feng Liu; Denes Molnar; Fuqiang Wang

    2015-07-02

    We trace the development of elliptic anisotropy ($v_2$) via parton-parton collision history in two transport models. The parton $v_2$ is studied as a function of the number of collisions of each parton in Au+Au and $d$+Au collisions at $\\sqrt{s_{_{\\rm NN}}}=200$~GeV. It is found that the majority of $v_2$ comes from the anisotropic escape probability of partons, with no fundamental difference at low and high transverse momenta. The contribution to $v_2$ from hydrodynamic-type collective flow is found to be small. Only when the parton-parton cross-section is set unrealistically large does this contribution start to take over. Our findings challenge the current paradigm emerged from hydrodynamic comparisons to anisotropy data.

  3. Three-terminal magnetic tunneling junction device with perpendicular anisotropy CoFeB sensing layer

    SciTech Connect (OSTI)

    Honjo, H. Nebashi, R.; Tokutome, K.; Miura, S.; Sakimura, N.; Sugibayashi, T.; Fukami, S.; Kinoshita, K.; Murahata, M.; Kasai, N.; Ishihara, K.; Ohno, H.

    2014-05-07

    We demonstrated read and write characteristics of a three terminal memory device with a perpendicular anisotropy-free layer of a strip of [Co/Ni] and a low-switching perpendicular-anisotropy CoFeB/MgO sensing layer. This new design of the cell results in a small cell area. The switching magnetic field of the sensing layer can be decreased by changing sputtering gas for the Ta-cap from Ar to Kr. An electron energy-loss spectroscopy analysis of the cross-section of the magnetic tunneling junction (MTJ) revealed that the boron content in CoFeB with a Kr-sputtered Ta-cap was smaller than that with an Ar-sputtered one. A change in resistance for the MTJ was observed that corresponded to the magnetic switching of the Co/Ni wire and its magnetoresistance ratio and critical current were 90% and 0.8?mA, respectively.

  4. Ultra-directional super-scattering of homogenous spherical particles with radial anisotropy

    E-Print Network [OSTI]

    Liu, Wei

    2015-01-01

    We study the light scattering of homogenous radially-anisotropic spherical particles. It is shown that radial anisotropy can be employed to tune effectively the electric resonances, and thus enable flexible overlapping of electric and magnetic dipoles of various numbers, which leads to unidirectional forward super-scattering at different spectral positions. We further reveal that through adjusting the radial anisotropy parameters, electric and magnetic resonances of higher orders can be also made overlapped, thus further collimating the forward scattering lobes. The ultra-directional super-scattering we have obtained with individual homogenous radially anisotropic spherical particles may shed new light to the design of compact and efficient nanoantennas, which may find various applications in solar cells, bio-sensing and many other antenna based researches.

  5. Sputtering of cobalt film with perpendicular magnetic anisotropy on disorder-free graphene

    SciTech Connect (OSTI)

    Jamali, Mahdi; Lv, Yang; Zhao, Zhengyang; Wang, Jian-Ping, E-mail: jpwang@umn.edu [Department of Electrical and Computer Engineering, University of Minnesota, 4-174 200 Union Street SE, Minneapolis, MN 55455 (United States)

    2014-10-15

    Growth of thin cobalt film with perpendicular magnetic anisotropy has been investigated on pristine graphene for spin logic and memory applications. By reduction of the kinetic energy of the sputtered atoms using indirect sputtered deposition, deposition induced defects in the graphene layer have been controlled. Cobalt film on graphene with perpendicular magnetic anisotropy has been developed. Raman spectroscopy of the graphene surface shows very little disorder induced in the graphene by the sputtering process. In addition, upon increasing the cobalt film thickness, the disorder density increases on the graphene and saturates for thicknesses of Co layers above 1 nm. The AFM image indicates a surface roughness of about 0.86 nm. In addition, the deposited film forms a granular structure with a grain size of about 40 nm.

  6. Modification of structure and magnetic anisotropy of epitaxial CoFe?O? films by hydrogen reduction

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

    Chen, Aiping; Poudyal, Narayan; Xiong, Jie; Liu, J. Ping; Jia, Quanxi

    2015-03-16

    Heteroepitaxial CoFe?O? (CFO) thin films with different thicknesses were deposited on MgO (001) substrates. The as-deposited CFO films show a clear switching of magnetic anisotropy with increasing film thickness. The thinner films (more »films are textured out-of-plane and aligned in-plane, owing to lattice matching between CoFe? and MgO substrate. TEM results indicate that as-deposited films are continuous while the annealed films exhibit a nanopore mushroom structure. The magnetic anisotropy of CoFe? films is dominated by the shape effect. The results demonstrate that hydrogen reduction can be effectively used to modify microstructures and physical properties of complex metal oxide materials.« less

  7. Interfacial oxygen migration and its effect on the magnetic anisotropy in Pt/Co/MgO/Pt films

    SciTech Connect (OSTI)

    Chen, Xi; Feng, Chun E-mail: ghyu@mater.ustb.edu.cn; Liu, Yang; Jiang, Shaolong; Hua Li, Ming; Hua Yu, Guang E-mail: ghyu@mater.ustb.edu.cn; Long Wu, Zheng; Yang, Feng

    2014-02-03

    This paper reports the interfacial oxygen migration effect and its induced magnetic anisotropy evolution in Pt/Co/MgO/Pt films. During depositing the MgO layer, oxygen atoms from the MgO combine with the neighboring Co atoms, leading to the formation of CoO at the Co/MgO interface. Meanwhile, the films show in-plane magnetic anisotropy (IMA). After annealing, most of the oxygen atoms in CoO migrate back to the MgO layer, resulting in obvious improvement of Co/MgO interface and the enhancement of effective Co-O orbital hybridization. These favor the evolution of magnetic anisotropy from IMA to perpendicular magnetic anisotropy (PMA). The oxygen migration effect is achieved by the redox reaction at the Co/MgO interface. On the contrary, the transfer from IMA to PMA cannot be observed in Pt/Co/Pt films due to the lack of interfacial oxygen migration.

  8. The integration of seismic anisotropy and reservoir performance data for characterization of naturally fractured reservoirs using discrete feature network models 

    E-Print Network [OSTI]

    Will, Robert A.

    2004-09-30

    This dissertation presents the development of a method for quantitative integration of seismic (elastic) anisotropy attributes with reservoir performance data as an aid in characterization of systems of natural fractures ...

  9. On the Observation of the Cosmic Ray Anisotropy below 10$^{15}$ eV

    E-Print Network [OSTI]

    G. Di Sciascio; R. Iuppa

    2014-07-08

    The measurement of the anisotropy in the arrival direction of cosmic rays is complementary to the study of their energy spectrum and chemical composition to understand their origin and propagation. It is also a tool to probe the structure of the magnetic fields through which cosmic rays travel. As cosmic rays are mostly charged nuclei, their trajectories are deflected by the action of galactic magnetic field they propagate through before reaching the Earth atmosphere, so that their detection carries directional information only up to distances as large as their gyro-radius. If cosmic rays below $10^{15}{\\rm\\,eV}$ are considered and the local galactic magnetic field ($\\sim3{\\rm\\,\\mu G}$) is accounted for, gyro-radii are so short that isotropy is expected. At most, a weak di-polar distribution may exist, reflecting the contribution of the closest CR sources. However, a number of experiments observed an energy-dependent \\emph{"large scale"} anisotropy in the sidereal time frame with an amplitude of about 10$^{-4}$ - 10$^{-3}$, revealing the existence of two distinct broad regions: an excess distributed around 40$^{\\circ}$ to 90$^{\\circ}$ in Right Ascension (commonly referred to as "tail.in" excess) and a deficit (the "loss cone") around 150$^{\\circ}$ to 240$^{\\circ}$ in Right Ascension. In recent years the Milagro and ARGO-YBJ collaborations reported the of a "medium" scale anisotropy inside the tail-in region. The observation of such small features has been recently claimed by the IceCube experiment also in the Southern hemisphere. So far, no theory of cosmic rays in the Galaxy exists which is able to explain the origin of these different anisotropies leaving the standard model of cosmic rays and that of the galactic magnetic field unchanged at the same time.

  10. Process and apparatus for preparing textured crystalline materials using anisotropy in the paramagnetic susceptibility

    DOE Patents [OSTI]

    Holloway, A.

    1992-01-07

    The present invention discloses a process and apparatus for forming textures in materials. The process comprises heating a material having an anisotropy in the paramagnetic or diamagnetic susceptibility within a magnetic field. The material is heated to a temperature approaching its melting point while a magnetic field of at least 10[sup 4]Oe is simultaneously applied. The process and apparatus produce highly textured bulk and elongated materials with high current densities below critical superconducting temperatures. 6 figs.

  11. Effects of pressure anisotropy on magnetospheric magnetohydrodynamics equilibrium of an internal ring current system

    SciTech Connect (OSTI)

    Furukawa, M., E-mail: furukawa@damp.tottori-u.ac.jp [Graduate School of Engineering, Tottori University, Tottori 680-8552 (Japan)

    2014-01-15

    Effects of pressure anisotropy on magnetospheric magnetohydrodynamics equilibrium are studied analytically and numerically, where the plasma is confined by only poloidal magnetic field generated by an internal ring current. The plasma current due to finite pressure can be divided into two components; one remains at isotropic pressure and the other arises from pressure anisotropy. When p{sub ?}, the pressure perpendicular to the magnetic field, is larger than p{sub ?}, the pressure parallel to the magnetic field, those two components of plasma current tend to cancel each other to reduce the total amount of plasma current. Equilibrium beta limit is also examined, where the beta is a ratio of the plasma pressure to the magnetic pressure. The equilibrium beta limit decreases as the pressure anisotropy becomes strong. The beta value is strictly limited by ellipticity of the equilibrium equation when p{sub ?}>p{sub ?}. On the other hand, when p{sub ?}>p{sub ?}, although the tendency of the beta limit agrees with the ellipticity condition of the equilibrium equation, equilibria with a hyperbolic region can be obtained by iterative procedure with practically reasonable convergence criteria.

  12. Magnetic anisotropy barrier for spin tunneling in Mn{sub 12}O{sub 12} molecules

    SciTech Connect (OSTI)

    Pederson, M.R. [Center for Computational Materials Science--6392, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States)] [Center for Computational Materials Science--6392, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States); Khanna, S.N. [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)] [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)

    1999-10-01

    Electronic structure calculations on the nature of electronic states and the magnetic coupling in Mn-acetate [Mn{sub 12}O{sub 12}(RCOO){sub 16}(H{sub 2}O){sub 4}] molecules have been been carried out within the generalized gradient approximation to the density functional formalism. Our studies on this 100-atom molecule illustrate the role of the nonmagnetic carboxyl host in stabilizing the ferrimagnetic Mn{sub 12}O{sub 12} core and provide estimates of the local magnetic moment at the various sites. We provide a first density-functional-based prediction of the second-order magnetic anisotropy energy of this system. Results are in excellent agreement with experiment. To perform these calculations we introduce a simplified exact method for spin-orbit coupling and magnetic anisotropy energies in multicenter systems. This method is free of shape approximations and has other advantages as well. First, it is valid for periodic boundary conditions or finite systems and is independent of basis set choice. Second, the method does not require the calculation of electric field. Third, for applications to systems with a finite energy gap between occupied and unoccupied electronic states, a perturbative expansion allows for a simple determination of the magnetic anisotropy energy. {copyright} {ital 1999} {ital The American Physical Society}

  13. Theoretical calculations of magnetic order and anisotropy energies in molecular magnets

    SciTech Connect (OSTI)

    Pederson, M. R. [Center for Computational Materials Science - 6392, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States)] [Center for Computational Materials Science - 6392, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States); Porezag, D. V. [Center for Computational Materials Science - 6392, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States)] [Center for Computational Materials Science - 6392, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States); Kortus, J. [Center for Computational Materials Science - 6392, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States)] [Center for Computational Materials Science - 6392, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States); Khanna, S. N. [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)] [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)

    2000-05-01

    We present theoretical electronic structure calculations on the nature of electronic states and the magnetic coupling in the Mn{sub 12}O{sub 12} free cluster and the Mn{sub 12}O{sub 12}(RCOO){sub 16}(H{sub 2}O){sub 4} molecular magnetic crystal. The calculations have been performed with the all-electron full-potential NRLMOL code. We find that the free Mn{sub 12}O{sub 12} cluster relaxes to an antiferromagnetic cluster with no net moment. However, when coordinated by sixteen HCOO ligands and four H{sub 2}O groups, as it is in the molecular crystal, we find that the ferrimagnetic ordering and geometrical and magnetic structure observed in the experiments is restored. Local Mn moments for the free and ligandated molecular magnets are presented and compared to experiment. We identify the occupied and unoccupied electronic states that are most responsible for the formation of the large anisotropy barrier and use a recently developed full-space and full-potential method for calculating the spin-orbit coupling interaction and anisotropy energies. Our calculated second-order anisotropy energy is in excellent agreement with experiment. (c) 2000 American Institute of Physics.

  14. Reference Interaction Site Model and Optimized Perturbation theories of colloidal dumbbells with increasing anisotropy

    E-Print Network [OSTI]

    Gianmarco Munaò; Francisco Gàmez; Dino Costa; Carlo Caccamo; Francesco Sciortino; Achille Giacometti

    2015-05-26

    We investigate thermodynamic properties of anisotropic colloidal dumbbells in the frameworks provided by the Reference Interaction Site Model (RISM) theory and an Optimized Perturbation Theory (OPT), this latter based on a fourth-order high-temperature perturbative expansion of the free energy, recently generalized to molecular fluids. Our model is constituted by two identical tangent hard spheres surrounded by square-well attractions with same widths and progressively different depths. Gas-liquid coexistence curves are obtained by predicting pressures, free energies, and chemical potentials. In comparison with previous simulation results, RISM and OPT agree in reproducing the progressive reduction of the gas-liquid phase separation as the anisotropy of the interaction potential becomes more pronounced; in particular, the RISM theory provides reasonable predictions for all coexistence curves, bar the strong anisotropy regime, whereas OPT performs generally less well. Both theories predict a linear dependence of the critical temperature on the interaction strength, reproducing in this way the mean-field behavior observed in simulations; the critical density~--~that drastically drops as the anisotropy increases~--~turns to be less accurate. Our results appear as a robust benchmark for further theoretical studies, in support to the simulation approach, of self-assembly in model colloidal systems.

  15. Fermi-LAT gamma-ray anisotropy and intensity explained by unresolved Radio-Loud Active Galactic Nuclei

    E-Print Network [OSTI]

    Mattia Di Mauro; Alessandro Cuoco; Fiorenza Donato; Jennifer M. Siegal-Gaskins

    2014-12-02

    Radio-loud active galactic nuclei (AGN) are expected to contribute substantially to both the intensity and anisotropy of the isotropic gamma-ray background (IGRB). In turn, the measured properties of the IGRB can be used to constrain the characteristics of proposed contributing source classes. We consider individual subclasses of radio-loud AGN, including low-, intermediate-, and high-synchrotron-peaked BL Lacertae objects, flat-spectrum radio quasars, and misaligned AGN. Using updated models of the gamma-ray luminosity functions of these populations, we evaluate the energy-dependent contribution of each source class to the intensity and anisotropy of the IGRB. We find that collectively radio-loud AGN can account for the entirety of the IGRB intensity and anisotropy as measured by the Fermi Large Area Telescope (LAT). Misaligned AGN provide the bulk of the measured intensity but a negligible contribution to the anisotropy, while high-synchrotron-peaked BL Lacertae objects provide the dominant contribution to the anisotropy. In anticipation of upcoming measurements with the Fermi-LAT and the forthcoming Cherenkov Telescope Array, we predict the anisotropy in the broader energy range that will be accessible to future observations.

  16. Gravitational-wave Detection With Matter-wave Interferometers Based On Standing Light Waves

    E-Print Network [OSTI]

    Dongfeng Gao; Peng Ju; Baocheng Zhang; Mingsheng Zhan

    2011-03-25

    We study the possibility of detecting gravitational-waves with matter-wave interferometers, where atom beams are split, deflected and recombined totally by standing light waves. Our calculation shows that the phase shift is dominated by terms proportional to the time derivative of the gravitational wave amplitude. Taking into account future improvements on current technologies, it is promising to build a matter-wave interferometer detector with desired sensitivity.

  17. On the limits of uniaxial magnetic anisotropy tuning by a ripple surface pattern

    SciTech Connect (OSTI)

    Arranz, Miguel A. [Facultad de Ciencias Químicas, Universidad de Castilla-La Mancha, Avda. Camilo J. Cela 10, 13071 Ciudad Real (Spain); Colino, Jose M., E-mail: josemiguel.colino@uclm.es [Instituto de Nanociencia, Nanotecnología y Materiales Moleculares, Universidad de Castilla-La Mancha, Campus de la Fábrica de Armas, 45071 Toledo (Spain); Palomares, Francisco J. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, c/ Sor Juana Inés de la Cruz 3, 28049 Madrid (Spain)

    2014-05-14

    Ion beam patterning of a nanoscale ripple surface has emerged as a versatile method of imprinting uniaxial magnetic anisotropy (UMA) on a desired in-plane direction in magnetic films. In the case of ripple patterned thick films, dipolar interactions around the top and/or bottom interfaces are generally assumed to drive this effect following Schlömann's calculations for demagnetizing fields of an ideally sinusoidal surface [E. Schlömann, J. Appl. Phys. 41, 1617 (1970)]. We have explored the validity of his predictions and the limits of ion beam sputtering to induce UMA in a ferromagnetic system where other relevant sources of magnetic anisotropy are neglected: ripple films not displaying any evidence of volume uniaxial anisotropy and where magnetocrystalline contributions average out in a fine grain polycrystal structure. To this purpose, the surface of 100?nm cobalt films grown on flat substrates has been irradiated at fixed ion energy, fixed ion fluency but different ion densities to make the ripple pattern at the top surface with wavelength ? and selected, large amplitudes (?) up to 20?nm so that stray dipolar fields are enhanced, while the residual film thickness t?=?35–50?nm is sufficiently large to preserve the continuous morphology in most cases. The film-substrate interface has been studied with X-ray photoemission spectroscopy depth profiles and is found that there is a graded silicon-rich cobalt silicide, presumably formed during the film growth. This graded interface is of uncertain small thickness but the range of compositions clearly makes it a magnetically dead layer. On the other hand, the ripple surface rules both the magnetic coercivity and the uniaxial anisotropy as these are found to correlate with the pattern dimensions. Remarkably, the saturation fields in the hard axis of uniaxial continuous films are measured up to values as high as 0.80 kG and obey a linear dependence on the parameter ?{sup 2}/?/t in quantitative agreement with Schlömann's prediction for a surface anisotropy entirely ruled by dipolar interaction. The limits of UMA tuning by a ripple pattern are discussed in terms of the surface local angle with respect to the mean surface and of the onset of ripple detachment.

  18. Explosive plane-wave lens

    DOE Patents [OSTI]

    Marsh, S.P.

    1988-03-08

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 4 figs.

  19. Explosive plane-wave lens

    DOE Patents [OSTI]

    Marsh, S.P.

    1987-03-12

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 3 figs., 3 tabs.

  20. Piezoelectric wave motor

    DOE Patents [OSTI]

    Yerganian, Simon Scott (Lee's Summit, MO)

    2001-07-17

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  1. Standing wave compressor

    DOE Patents [OSTI]

    Lucas, Timothy S. (4614 River Mill Ct., Glen Allen, VA 23060)

    1991-01-01

    A compressor for compression-evaporation cooling systems, which requires no moving parts. A gaseous refrigerant inside a chamber is acoustically compressed and conveyed by means of a standing acoustic wave which is set up in the gaseous refrigerant. This standing acoustic wave can be driven either by a transducer, or by direct exposure of the gas to microwave and infrared sources, including solar energy. Input and output ports arranged along the chamber provide for the intake and discharge of the gaseous refrigerant. These ports can be provided with optional valve arrangements, so as to increase the compressor's pressure differential. The performance of the compressor in either of its transducer or electromagnetically driven configurations, can be optimized by a controlling circuit. This controlling circuit holds the wavelength of the standing acoustical wave constant, by changing the driving frequency in response to varying operating conditions.

  2. Adaptive multiconfigurational wave functions

    SciTech Connect (OSTI)

    Evangelista, Francesco A.

    2014-03-28

    A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff ?. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than ?. The resulting ?-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (?+SD-CI), which is based on a small ?-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build ?-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The ?-CI and ?+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the ?-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the ?-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.

  3. QGP time formation in holographic shock waves model of heavy ion collisions

    E-Print Network [OSTI]

    Aref'eva, Irina Ya

    2015-01-01

    We estimate the thermalization time in two colliding shock waves holographic model of heavy-ion collisions. For this purpose we model the process by the Vaidya metric with a horizon defined by the trapped surface location. We consider two bottom-up AdS/QCD models that give, within the colliding shock waves approach, the dependence of multiplicity on the energy compatible with RHIC and LHC results. One model is a bottom-up AdS/QCD confining model and the other is related to an anisotropic thermalization. We estimate the thermalization time and show that increasing the confining potential decreases the thermalization time as well as an anisotropy accelerates the thermalization.

  4. QGP time formation in holographic shock waves model of heavy ion collisions

    E-Print Network [OSTI]

    Irina Ya. Aref'eva

    2015-03-07

    We estimate the thermalization time in two colliding shock waves holographic model of heavy-ion collisions. For this purpose we model the process by the Vaidya metric with a horizon defined by the trapped surface location. We consider two bottom-up AdS/QCD models that give, within the colliding shock waves approach, the dependence of multiplicity on the energy compatible with RHIC and LHC results. One model is a bottom-up AdS/QCD confining model and the other is related to an anisotropic thermalization. We estimate the thermalization time and show that increasing the confining potential decreases the thermalization time as well as an anisotropy accelerates the thermalization.

  5. Thermoplastic waves in magnetars

    E-Print Network [OSTI]

    Beloborodov, Andrei M

    2014-01-01

    Magnetar activity is generated by shear motions of the neutron star surface, which relieve internal magnetic stresses. An analogy with earthquakes and faults is problematic, as the crust is permeated by strong magnetic fields, which greatly constrain crustal displacements. We describe a new deformation mechanism that is specific to strongly magnetized neutron stars. The magnetically stressed crust begins to move because of a thermoplastic instability, which launches a wave that shears the crust and burns its magnetic energy. The propagating wave front resembles the deflagration front in combustion physics. We describe the conditions for the instability, the front structure and velocity, and discuss implications for observed magnetar activity.

  6. Wave runup on cylinders subject to deep water random waves 

    E-Print Network [OSTI]

    Indrebo, Ann Kristin

    2001-01-01

    runup. Laboratory measurements of irregular waves interfering with vertical platform cylinders were used to obtain the Weibull coefficients necessary for the analytical model. Six data sets with different configurations where the wave elevation...

  7. Real-time Water Waves with Wave Particles 

    E-Print Network [OSTI]

    Yuksel, Cem

    2010-10-12

    This dissertation describes the wave particles technique for simulating water surface waves and two way fluid-object interactions for real-time applications, such as video games. Water exists in various different forms in our environment...

  8. Heat Waves, Global Warming, and Mitigation

    E-Print Network [OSTI]

    Carlson, Ann E.

    2008-01-01

    Heat Waves, Global Warming, and Mitigation Ann E. Carlson*2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 175 stroke2001). 2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 177

  9. mm-Wave Phase Shifters and Switches

    E-Print Network [OSTI]

    Adabi Firouzjaei, Ehsan

    2010-01-01

    combiners . . . . . . . . . . . 5.3 mm-Wave implementationfailed to predict current mm-wave design trend [1] . . . . .solutions . . . . . . . . mm-wave imaging for medical and

  10. Cellular Mechanisms Underlying Retinal Wave Generation

    E-Print Network [OSTI]

    Ford, Kevin

    2011-01-01

    Underlying Retinal Wave Generation By Kevin J Ford AUnderlying Retinal Wave Generation By Kevin J Ford Doctor ofwith age, so does the wave generation mechanism. The most

  11. Guided wave monitoring of prestressing tendons

    E-Print Network [OSTI]

    Nucera, Claudio

    2010-01-01

    and applications of ultrasonic waves. CRC series in pure andStrands by Guided Stress Waves, ASCE Journal of Materials inin Cable Stays via Guided Wave Magnetostrictive Ultrasonics,

  12. mm-Wave Phase Shifters and Switches

    E-Print Network [OSTI]

    Adabi Firouzjaei, Ehsan

    2010-01-01

    4.1.1 Slow wave transmissioncombiners . . . . . . . . . . . 5.3 mm-Wave implementationfailed to predict current mm-wave design trend [1] . . . . .

  13. Super compact equation for water waves

    E-Print Network [OSTI]

    Dyachenko, A I; Zakharov, V E

    2015-01-01

    We derive very simple compact equation for gravity water waves which includes nonlinear wave term (`a la NLSE) and advection term (may results in wave breaking).

  14. California Small Hydropower and Ocean Wave Energy

    E-Print Network [OSTI]

    California Small Hydropower and Ocean Wave Energy Resources IN SUPPORT OF THE 2005 INTEGRATED....................................................................................................................... 9 Ocean Wave Energy............................................................................................................. 20 Wave Energy Conversion Technology

  15. Generating Electromagnetic Waves from Gravity Waves in Cosmology

    E-Print Network [OSTI]

    P. A. Hogan; S. O'Farrell

    2009-05-18

    Examples of test electromagnetic waves on a Friedmann-Lemaitre-Robertson-Walker(FLRW) background are constructed from explicit perturbations of the FLRW space-times describing gravitational waves propagating in the isotropic universes. A possible physical mechanism for the production of the test electromagnetic waves is shown to be the coupling of the gravitational waves with a test magnetic field, confirming the observation of Marklund, Dunsby and Brodin [Phys.Rev. D62,101501(R) (2000)].

  16. Wave refraction and wave energy on Cayo Arenas 

    E-Print Network [OSTI]

    Walsh, Donald Eugene

    1962-01-01

    WAVE REFRACTION AND WAVE ENERGY ON CAYO ARENAS A Thesis By Donald E. Welsh Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... January 1962 Major Subject: Physical Oceanography WAVE REFRACTION AND WAVE ENERGY ON CAYO ARENAS A Thesis Donald E. Walsh Approved as to style and content by: Chairman of the Committee ead of Department ' / January 1962 ACKNOWLEDGMENTS...

  17. LONG WAVE EXPANSIONS FOR WATER WAVES OVER RANDOM TOPOGRAPHY

    E-Print Network [OSTI]

    LONG WAVE EXPANSIONS FOR WATER WAVES OVER RANDOM TOPOGRAPHY ANNE DE BOUARD 1 , WALTER CRAIG 2 with the ran­ dom bottom. We show that the resulting influence of the random topography is expressed in terms of bottom topography a#ects the equations describing the limit of solutions in the long wave regime. We

  18. Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment

    E-Print Network [OSTI]

    James, L. Allan

    Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment L. Allan James* Geography Department, University South Carolina Abstract The concept of sediment waves is reviewed and clarifications are proposed for nomenclature con- cerning vertical channel responses to large fluvial sediment fluxes over a period of a decade

  19. Wave Propagation Theory 2.1 The Wave Equation

    E-Print Network [OSTI]

    2 Wave Propagation Theory 2.1 The Wave Equation The wave equation in an ideal fluid can be derived from hydrodynamics and the adia- batic relation between pressure and density. The equation for conservation of mass, Euler's equation (Newton's 2nd Law), and the adiabatic equation of state are respec

  20. Water Waves and Integrability

    E-Print Network [OSTI]

    Rossen I. Ivanov

    2007-07-12

    The Euler's equations describe the motion of inviscid fluid. In the case of shallow water, when a perturbative asymtotic expansion of the Euler's equations is taken (to a certain order of smallness of the scale parameters), relations to certain integrable equations emerge. Some recent results concerning the use of integrable equation in modeling the motion of shallow water waves are reviewed in this contribution.

  1. Deflagration Wave Profiles

    SciTech Connect (OSTI)

    Menikoff, Ralph

    2012-04-03

    Shock initiation in a plastic-bonded explosives (PBX) is due to hot spots. Current reactive burn models are based, at least heuristically, on the ignition and growth concept. The ignition phase occurs when a small localized region of high temperature (or hot spot) burns on a fast time scale. This is followed by a growth phase in which a reactive front spreads out from the hot spot. Propagating reactive fronts are deflagration waves. A key question is the deflagration speed in a PBX compressed and heated by a shock wave that generated the hot spot. Here, the ODEs for a steady deflagration wave profile in a compressible fluid are derived, along with the needed thermodynamic quantities of realistic equations of state corresponding to the reactants and products of a PBX. The properties of the wave profile equations are analyzed and an algorithm is derived for computing the deflagration speed. As an illustrative example, the algorithm is applied to compute the deflagration speed in shock compressed PBX 9501 as a function of shock pressure. The calculated deflagration speed, even at the CJ pressure, is low compared to the detonation speed. The implication of this are briefly discussed.

  2. Shear-wave splitting as a tool for the characterization of geothermal...

    Open Energy Info (EERE)

    anisotropy induced by aligned cracks and micro-cracks in an otherwise isotropic matrix. The presence of lithologic anisotropy andor strong heterogeneity in the reservoir...

  3. Transformative Wave Technologies Kent, Washington

    E-Print Network [OSTI]

    California at Davis, University of

    Transformative Wave Technologies Kent, Washington www.transformativewave.com #12;#12;North America are shifted to off peak times #12;#12;Transformative Wave Technologies www.transformativewave.com #12

  4. 3-point temperature anisotropies in WMAP: Limits on CMB non-Gaussianities and non-linearities

    E-Print Network [OSTI]

    E. Gaztanaga; J. Wagg

    2003-06-12

    We present a study of the 3-pt angular correlation function w_3= of (adimensional) temperature anisotropies measured by the Wilkinson Microwave Anisotropy Probe (WMAP). Results can be normalized to the 2-point function w_2 = in terms of the hierarchical: q_3 ~ w_3/w_2^2 or dimensionless: d_3 ~ w_2/w_2^{3/2}$ amplitudes. Strongly non-Gaussian models are generically expected to show d_3 > 1 or q_3 > 10^3 d_3. Unfortunately, this is comparable to the cosmic variance on large angular scales. For Gaussian primordial models, q_3 gives a direct measure of the non-linear corrections to temperature anisotropies in the sky: delta = delta_L + f_{NLT} (delta_L^2 - ) with f_{NLT} = q_3/2 for the leading order term in w_2^2. We find good agreement with the Gaussian hypothesis d_3 ~ 0 within the cosmic variance of LCDM simulations (with or without a low quadrupole). The strongest constraints on q_3 come from scales smaller than 1 degree. We find q_3 =19 +/-141 for (pseudo) collapsed configurations and an average of q_3 = 336 +/-218 for non-collapsed triangles. The corresponding non-linear coupling parameter, f_{NL}, for curvature perturbations Phi, in the Sachs-Wolfe (SW) regime is: f_{NL}^{SW} = q_3/6, while on degree scales, the extra power in acoustic oscillations produces f_{NL} ~ q_3/30 in the LCM model. Errors are dominated by cosmic variance, but for the first time they begin to be small enough to constrain the leading order non-linear effects with coupling of order unity.

  5. Electromagnetic Weibel Instability in Intense Charged Particle Beams with Large Energy Anisotropy

    SciTech Connect (OSTI)

    Edward A. Startsev; Ronald C. Davidson

    2003-10-20

    In plasmas with strongly anisotropic distribution functions, collective instabilities may develop if there is sufficient coupling between the transverse and longitudinal degrees of freedom. Our previous numerical and theoretical studies of intense charged particle beams with large temperature anisotropy [E. A. Startsev, R. C. Davidson and H. Qin, PRSTAB, 6, 084401 (2003); Phys. Plasmas 9, 3138 (2002)] demonstrated that a fast, electrostatic, Harris-like instability develops, and saturates nonlinearly, for sufficiently large temperature anisotropy (T{sub {perpendicular}b}/T{sub {parallel}b} >> 1). The total distribution function after saturation, however, is still far from equipartitioned. In this paper the linearized Vlasov-Maxwell equations are used to investigate detailed properties of the transverse electromagnetic Weibel-type instability for a long charge bunch propagating through a cylindrical pipe of radius r{sub w}. The kinetic stability analysis is carried out for azimuthally symmetric perturbations about a two-temperature thermal equilibrium distribution in the smooth-focusing approximation. The most unstable modes are identified, and their eigenfrequencies, radial mode structure and instability thresholds are determined. The stability analysis shows that, although there is free energy available to drive the electromagnetic Weibel instability, the finite transverse geometry of the charged particle beam introduces a large threshold value for the temperature anisotropy ((T{sub {perpendicular}b}/T{sub {parallel}b}){sup Weibel} >> (T{sub {perpendicular}b}/T{sub {parallel}b}){sup Harris}) below which the instability is absent. Hence, unlike the case of an electrically neutral plasma, the Weibel instability is not expected to play as significant a role in the process of energy isotropization of intense unneutralized charged particle beams as the electrostatic Harris-type instability.

  6. Arnold Schwarzenegger CALIFORNIA OCEAN WAVE

    E-Print Network [OSTI]

    Arnold Schwarzenegger Governor CALIFORNIA OCEAN WAVE ENERGY ASSESSMENT Prepared For: California, State and Federal Agencies and their expectations in respect to potential wave power deployments Jim a huge amount of wave measurement data from various data sources Asfaw Beyene of the Department

  7. Water wave interactions Walter Craig

    E-Print Network [OSTI]

    Thomann, Laurent

    Water wave interactions Walter Craig Department of Mathematics & Statistics ´EquationsMaster University) Water wave interactions 25 janvier 2011 1 / 34 #12;Joint work with: Philippe Guyenne University, Killam Research Fellows Program, Fields Institute Walter Craig (McMaster University) Water wave

  8. Extreme wave impinging and overtopping 

    E-Print Network [OSTI]

    Ryu, Yong Uk

    2009-06-02

    This investigates the velocity fields of a plunging breaking wave impinging on a structure through measurements in a two-dimensional wave tank. As the wave breaks and overtops the structure, so-called green water is generated. The flow becomes multi...

  9. 2, 70177025, 2014 Freaque wave

    E-Print Network [OSTI]

    NHESSD 2, 7017­7025, 2014 Freaque wave occurrences in 2013 P. C. Liu Title Page Abstract to the corresponding final paper in NHESS if available. Brief Communication: Freaque wave occurrences in 2013 P. C. Liu­7025, 2014 Freaque wave occurrences in 2013 P. C. Liu Title Page Abstract Introduction Conclusions References

  10. 2014 Tube -1 STANDING WAVES

    E-Print Network [OSTI]

    Gustafsson, Torgny

    2014 Tube - 1 STANDING WAVES IN AN AIR COLUMN The objective of the experiment is: · To study the harmonic structure of standing waves in an air column. APPARATUS: Computer, FFTScope software, PC speaker will produce nothing noteworthy. But, if the phase relationship is correct, standing waves can be formed

  11. Tunable giant magnetic anisotropy in amorphous SmCo thin films

    SciTech Connect (OSTI)

    Magnus, F.; Moubah, R.; Roos, A. H.; Kapaklis, V.; Hjoervarsson, B.; Andersson, G.; Kruk, A.; Hase, T.

    2013-04-22

    SmCo thin films have been grown by magnetron sputtering at room temperature with a composition of 2-35 at. % Sm. Films with 5 at. % or higher Sm are amorphous and smooth. A giant tunable uniaxial in-plane magnetic anisotropy is induced in the films which peaks in the composition range 11-22 at. % Sm. This cross-over behavior is not due to changes in the atomic moments but rather the local configuration changes. The excellent layer perfection combined with highly tunable magnetic properties make these films important for spintronics applications.

  12. Random anisotropy disorder in superfluid 3He-A in aerogel

    E-Print Network [OSTI]

    G. E. Volovik

    2006-10-04

    The anisotropic superfluid 3He-A in aerogel provides an interesting example of a system with continuous symmetry in the presence of random anisotropy disorder. Recent NMR experiments allow us to discuss two regimes of the orientational disorder, which have different NMR properties. One of them, the (s)-state, is identified as the pure Larkin-Imry-Ma state. The structure of another state, the (f)-state, is not very clear: probably it is the Larkin-Imry-Ma state contaminated by the network of the topological defects pinned by aerogel.

  13. Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since

    E-Print Network [OSTI]

    Rutledge, Steven

    Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since radar involves the transmission, propagation and scattering of EM waves by various is the electrostatic force between two point charges. #12;Electromagnetic WavesElectromagnetic Waves Electric fields

  14. Contribution of individual interfaces in the MgO/Co/Pd trilayer to perpendicular magnetic anisotropy upon annealing

    SciTech Connect (OSTI)

    Kim, Minseok; Kim, Sanghoon; Ko, Jungho; Hong, Jongill

    2015-03-09

    The contribution of each interface of the MgO/Co/Pd trilayer to the perpendicular magnetic anisotropy (PMA) was studied by changing chemical and crystalline structures through annealing. We found that volumetric anisotropy in the MgO/Co/Pd trilayer was significantly increased due to enhanced magnetoelastic anisotropy caused by stress built up most likely at the MgO/Co interface during annealing. When the trilayer was annealed at 400?°C, the alloy formation at the Co/Pd interface additionally increased the volumetric anisotropy. Our x-ray magnetic circular dichroism study supported that those structural modifications led to an increase in the orbital moment through spin-orbit coupling (SOC) along the film normal two times larger than that of the as-deposited trilayer, thereby enhancing PMA greatly. Our experimental results prove that the Co/Pd interface, rather than the MgO/Co interface, plays an essential role in inducing strong PMA in the trilayer. The precise investigation of annealing effect on both volumetric and interfacial anisotropies can provide a methodological solution to improve the SOC of the trilayer that can serve as the core unit of spintronic devices.

  15. Chiral Heat Wave and wave mixing in chiral media

    E-Print Network [OSTI]

    Chernodub, M N

    2015-01-01

    We show that a hot rotating fluid of relativistic chiral fermions possesses a new gapless collective excitation associated with coherent propagation of energy density and chiral density waves along the axis of rotation. This excitation, which we call the Chiral Heat Wave, emerges due to a mixed gauge-gravitational anomaly. At finite density the Chiral Heat Wave couples to the Chiral Vortical Wave while in the presence of an external magnetic field it mixes with the Chiral Magnetic Wave. We find that the coupled waves - which are coherent fluctuations of the vector, axial and energy currents - have generally different velocities compared to the velocities of the individual waves. We also demonstrate that rotating chiral systems subjected to external magnetic field possess non-propagating metastable thermal excitations, the Dense Hot Spots.

  16. Two Problems in Computational Wave Dynamics: Klemp-Wilhelmson Splitting at Large Scales and Wave-Wave Instabilities in Rotating Mountain Waves 

    E-Print Network [OSTI]

    Viner, Kevin Carl

    2011-02-22

    IN COMPUTATIONAL WAVE DYNAMICS: KLEMP-WILHELMSON SPLITTING AT LARGE SCALES AND WAVE-WAVE INSTABILITIES IN ROTATING MOUNTAIN WAVES A Dissertation by KEVIN CARL VINER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2009 Major Subject: Atmospheric Sciences TWO PROBLEMS IN COMPUTATIONAL WAVE DYNAMICS: KLEMP-WILHELMSON SPLITTING AT LARGE SCALES AND WAVE-WAVE INSTABILITIES IN ROTATING MOUNTAIN WAVES A Dissertation...

  17. Geophysical Prospecting 39, 337-355, 1991 EXTENSIVE-DILATANCY ANISOTROPY

    E-Print Network [OSTI]

    Edinburgh, University of

    in synthetic shear-waves in reflection gathers and VSPs, in order to assess the relative merits of the two, and the behaviour of shear-wave splitting is dominated by the structure of the rock mass in the vicinity and preferentially aligned pore-space, which pervade most rocks in the crust and are ' Received January 1990

  18. Noise sustained waves in subexcitable media: From chemical waves to brain waves

    E-Print Network [OSTI]

    Showalter, Kenneth

    Noise sustained waves in subexcitable media: From chemical waves to brain waves P. Junga the threshold of pat- tern formation, noise can sustain locally coherent pat- terns. The patterns exhibit of nonequilibrium statistical phys- ics, noise has been recognized to play an important role in the formation

  19. Nonlinear Hysteretic Torsional Waves

    E-Print Network [OSTI]

    J. Cabaret; P. Béquin; G. Theocharis; V. Andreev; V. E. Gusev; V. Tournat

    2015-01-09

    We theoretically study and experimentally report the propagation of nonlinear hysteretic torsional pulses in a vertical granular chain made of cm-scale, self-hanged magnetic beads. As predicted by contact mechanics, the torsional coupling between two beads is found nonlinear hysteretic. This results in a nonlinear pulse distortion essentially different from the distortion predicted by classical nonlinearities, and in a complex dynamic response depending on the history of the wave particle angular velocity. Both are consistent with the predictions of purely hysteretic nonlinear elasticity and the Preisach-Mayergoyz hysteresis model, providing the opportunity to study the phenomenon of nonlinear dynamic hysteresis in the absence of other type of material nonlinearities. The proposed configuration reveals a plethora of interesting phenomena including giant amplitude-dependent attenuation, short term memory as well as dispersive properties. Thus, it could find interesting applications in nonlinear wave control devices such as strong amplitude-dependent filters.

  20. Fractional Electromagnetic Waves

    E-Print Network [OSTI]

    J. F. Gómez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Guía

    2011-08-31

    In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.

  1. wave velocity group velocity

    E-Print Network [OSTI]

    Walker, D. Greg

    -11 3.5e-11 4e-11 4.5e-11 5e-11 400 500 600 700 800 900 1000 location(nm) temperature(K) wave location 15 20 25 0 2 4 6 8 10 12 numberdensity(a.u.) frequency (THz) Summary Model Simulation Results Context. - Seitz and Koehler (1956) solve Boltzmann transport equations Monte Carlo approach is used to· 90 100 3e

  2. DNA waves and water

    E-Print Network [OSTI]

    L. Montagnier; J. Aissa; E. Del Giudice; C. Lavallee; A. Tedeschi; G. Vitiello

    2010-12-23

    Some bacterial and viral DNA sequences have been found to induce low frequency electromagnetic waves in high aqueous dilutions. This phenomenon appears to be triggered by the ambient electromagnetic background of very low frequency. We discuss this phenomenon in the framework of quantum field theory. A scheme able to account for the observations is proposed. The reported phenomenon could allow to develop highly sensitive detection systems for chronic bacterial and viral infections.

  3. Tunable exchange bias-like effect in patterned hard-soft two-dimensional lateral composites with perpendicular magnetic anisotropy

    SciTech Connect (OSTI)

    Hierro-Rodriguez, A., E-mail: ahierro@fc.up.pt; Alvarez-Prado, L. M.; Martín, J. I.; Alameda, J. M. [Departamento de Física, Universidad de Oviedo, C/Calvo Sotelo S/N, 33007 Oviedo (Spain); Centro de Investigación en Nanomateriales y Nanotecnología—CINN (CSIC—Universidad de Oviedo—Principado de Asturias), Parque Tecnológico de Asturias, 33428 Llanera (Spain); Teixeira, J. M. [IN-IFIMUP, Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua Campo Alegre 687, 4169-007 Porto (Portugal); Vélez, M. [Departamento de Física, Universidad de Oviedo, C/Calvo Sotelo S/N, 33007 Oviedo (Spain)

    2014-09-08

    Patterned hard-soft 2D magnetic lateral composites have been fabricated by e-beam lithography plus dry etching techniques on sputter-deposited NdCo{sub 5} thin films with perpendicular magnetic anisotropy. Their magnetic behavior is strongly thickness dependent due to the interplay between out-of-plane anisotropy and magnetostatic energy. Thus, the spatial modulation of thicknesses leads to an exchange coupled system with hard/soft magnetic regions in which rotatable anisotropy of the thicker elements provides an extra tool to design the global magnetic behavior of the patterned lateral composite. Kerr microscopy studies (domain imaging and magneto-optical Kerr effect magnetometry) reveal that the resulting hysteresis loops exhibit a tunable exchange bias-like shift that can be switched on/off by the applied magnetic field.

  4. Magnetic anisotropies in epitaxial Fe{sub 3}O{sub 4}/GaAs(100) patterned structures

    SciTech Connect (OSTI)

    Zhang, W. Zhang, D.; Yuan, S. J.; Huang, Z. C.; Zhai, Y.; Wong, P. K. J.; Wu, J.; Xu, Y. B.

    2014-10-15

    Previous studies on epitaxial Fe{sub 3}O{sub 4} rings in the context of spin-transfer torque effect have revealed complicated and undesirable domain structures, attributed to the intrinsic fourfold magnetocrystalline anisotropy in the ferrite. In this Letter, we report a viable solution to this problem, utilizing a 6-nm-thick epitaxial Fe{sub 3}O{sub 4} thin film on GaAs(100), where the fourfold magnetocrystalline anisotropy is negligible. We demonstrate that in the Fe{sub 3}O{sub 4} planar wires patterned from our thin film, such a unique magnetic anisotropy system has been preserved, and relatively simple magnetic domain configurations compared to those previous reports can be obtained.

  5. Alternating magnetic anisotropy of Li2(Li1–xTx)N(T=Mn,Fe,Co,andNi)

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

    Jesche, A.; Ke, L.; Jacobs, J. L.; Harmon, B.; Houk, R. S.; Canfield, P. C.

    2015-05-11

    Substantial amounts of the transition metals Mn, Fe, Co, and Ni can be substituted for Li in single crystalline Li2(Li1–xTx)N. Isothermal and temperature-dependent magnetization measurements reveal local magnetic moments with magnitudes significantly exceeding the spin-only value. The additional contributions stem from unquenched orbital moments that lead to rare-earth-like behavior of the magnetic properties. Accordingly, extremely large magnetic anisotropies have been found. Most notably, the magnetic anisotropy alternates as easy plane?easy axis?easy plane?easy axis when progressing from T = Mn ? Fe ? Co ? Ni. This behavior can be understood based on a perturbation approach in an analytical, single-ion model.more »As a result, the calculated magnetic anisotropies show surprisingly good agreement with the experiment and capture the basic features observed for the different transition metals.« less

  6. Alternating magnetic anisotropy of Li 2 ( Li 1 - x T x ) N ( T = Mn , Fe , Co , and Ni )

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

    Jesche, A.; Ke, L.; Jacobs, J. L.; Harmon, B.; Houk, R. S.; Canfield, P. C.

    2015-05-01

    Substantial amounts of the transition metals Mn, Fe, Co, and Ni can be substituted for Li in single crystalline Li?(Li1-xTx)N. Isothermal and temperature-dependent magnetization measurements reveal local magnetic moments with magnitudes significantly exceeding the spin-only value. The additional contributions stem from unquenched orbital moments that lead to rare-earth-like behavior of the magnetic properties. Accordingly, extremely large magnetic anisotropies have been found. Most notably, the magnetic anisotropy alternates as easy plane?easy axis?easy plane?easy axis when progressing from T = Mn ? Fe ? Co ? Ni. This behavior can be understood based on a perturbation approach in an analytical, single-ion model.more »The calculated magnetic anisotropies show surprisingly good agreement with the experiment and capture the basic features observed for the different transition metals.« less

  7. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

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

    Abreu, P

    2011-06-17

    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrativemore »values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.« less

  8. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

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

    Abreu, P [Lisbon, IST; Aglietta, M [IFSI, Turin; Ahn, E J [Fermilab; Albuquerque, I F.M. [Sao Paulo U.; Allard, D [APC, Paris; Allekotte, I [Centro Atomico Bariloche; Allen, J [New York U.; Allison, P [Ohio State U.; Alvarez Castillo, J [Mexico U., ICN; Alvarez-Muniz, J [Santiago de Compostela U.; Ambrosio, M [Napoli Seconda U.; INFN, Naples; Nijmegen U., IMAPP

    2011-06-17

    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

  9. Alternating magnetic anisotropy of Li 2 ( Li 1 - x T x ) N ( T = Mn , Fe , Co , and Ni )

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

    Jesche, A.; Ke, L.; Jacobs, J. L.; Harmon, B.; Houk, R. S.; Canfield, P. C.

    2015-05-01

    Substantial amounts of the transition metals Mn, Fe, Co, and Ni can be substituted for Li in single crystalline Li?(Li1-xTx)N. Isothermal and temperature-dependent magnetization measurements reveal local magnetic moments with magnitudes significantly exceeding the spin-only value. The additional contributions stem from unquenched orbital moments that lead to rare-earth-like behavior of the magnetic properties. Accordingly, extremely large magnetic anisotropies have been found. Most notably, the magnetic anisotropy alternates as easy plane?easy axis?easy plane?easy axis when progressing from T = Mn ? Fe ? Co ? Ni. This behavior can be understood based on a perturbation approach in an analytical, single-ion model. The calculated magnetic anisotropies show surprisingly good agreement with the experiment and capture the basic features observed for the different transition metals.

  10. Cosmic ray electron anisotropies as a tool to discriminate between exotic and astrophysical sources

    E-Print Network [OSTI]

    Cernuda, Ignacio

    2009-01-01

    Recent results from the PAMELA, ATIC, PPB BETS and Fermi collaborations extend the energy range in the electron flux measurement up to unexplored energies in the hundred GeVs range confirming the bump starting at about 10GeV already suggested by HEAT and AMS01 data . This bump can be explained by annihilating dark matter in the context of exotic physics, or by nearby astrophysical sources e.g. pulsars. In order to discriminate between competing models for primary positron production, the study of anisotropies ,complementary to the spectrum determination, shows up as new tool to look for the origin of the lepton excess. In this letter we calculate the contribution to the electron flux given by the collection of all known gamma ray pulsars (as listed in the ATNF catalogue) and by annihilating dark matter both in case of a clumpy halo or in case the excess can be atributed to a nearby sizeable dark matter clump. We address the problem of the electron anisotropy in both scenarios and estimate the prospect that a ...

  11. Temperature-dependent elastic anisotropy and mesoscale deformation in a nanostructured ferritic alloy

    SciTech Connect (OSTI)

    Stoica, Grigoreta M [ORNL; Stoica, Alexandru Dan [ORNL; Miller, Michael K [ORNL; Ma, Dong [ORNL

    2014-01-01

    Nanostructured ferritic alloys (NFA) are a new class of ultrafine-grained oxide dispersion-strengthened steels, promising for service in extreme environments of high temperature and high irradiation in the next-generation of nuclear reactors. This is owing to the remarkable stability of their complex microstructures containing a high density of Y-Ti-O nanoclusters within grains and along the grain boundaries. While nanoclusters have been recognized to be the primary contributor to the exceptional resistance to irradiation and high-temperature creep, very little is known about the mechanical roles of the polycrystalline grains that constitute the bulk ferritic matrix. Here we report the mesoscale characterization of anisotropic responses of the ultrafine NFA grains to tensile stresses at various temperatures using the state-of-the-art in situ neutron diffraction. We show the first experimental determination of temperature-dependent single-crystal elastic constants for the NFA, and reveal a strong temperature-dependent elastic anisotropy due to a sharp decrease in the shear stiffness constant [c'=(c_11-c_12)/2] when a critical temperature ( T_c ) is approached, indicative of elastic softening and instability of the ferritic matrix. We also show, from anisotropy-induced intergranular strain/stress accumulations, that a common dislocation slip mechanism operates at the onset of yielding for low temperatures, while there is a deformation crossover from low-temperature lattice hardening to high temperature lattice softening in response to extensive plastic deformation.

  12. On the Observation of the Cosmic Ray Anisotropy below 10$^{15}$ eV

    E-Print Network [OSTI]

    Di Sciascio, G

    2014-01-01

    The measurement of the anisotropy in the arrival direction of cosmic rays is complementary to the study of their energy spectrum and chemical composition to understand their origin and propagation. It is also a tool to probe the structure of the magnetic fields through which cosmic rays travel. As cosmic rays are mostly charged nuclei, their trajectories are deflected by the action of galactic magnetic field they propagate through before reaching the Earth atmosphere, so that their detection carries directional information only up to distances as large as their gyro-radius. If cosmic rays below $10^{15}{\\rm\\,eV}$ are considered and the local galactic magnetic field ($\\sim3{\\rm\\,\\mu G}$) is accounted for, gyro-radii are so short that isotropy is expected. At most, a weak di-polar distribution may exist, reflecting the contribution of the closest CR sources. However, a number of experiments observed an energy-dependent \\emph{"large scale"} anisotropy in the sidereal time frame with an amplitude of about 10$^{-4...

  13. Sensitivity of full-sky experiments to large scale cosmic ray anisotropies

    E-Print Network [OSTI]

    Denton, Peter B

    2015-01-01

    The two main advantages of space-based observation of extreme energy ($\\gtrsim5\\times10^{19}$ eV) cosmic rays (EECRs) over ground based observatories are the increased field of view and the full-sky coverage with nearly uniform systematics across the entire sky. The former guarantees increased statistics, whereas the latter enables a clean partitioning of the sky into spherical harmonics. The discovery of anisotropies would help to identify the long sought origin of EECRs. We begin an investigation of the reach of a full-sky space-based experiment such as EUSO to detect anisotropies in the extreme-energy cosmic-ray sky compared to ground based partial-sky experiments such as the Pierre Auger Observatory and Telescope Array. The technique is explained here, and simulations for a Universe with just two nonzero multipoles, monopole plus either dipole or quadrupole, are presented. These simulations quantify the advantages of space-based, all-sky coverage.

  14. Acceleration and Enrichment of 3He in Impulsive Solar Flares by Electron Firehose Waves

    E-Print Network [OSTI]

    G. Paesold; R. Kallenbach; A. O. Benz

    2002-09-08

    A new mechanism for acceleration and enrichment of 3He during impulsive solar flares is presented. Low-frequency electromagnetic plasma waves excited by the Electron Firehose Instability (EFI) can account for the acceleration of ions up to 1 MeV/amu energies as a single stage process. The EFI arises as a direct consequence of the free energy stored in a temperature anisotropy (T_parallel>T_perp) of the bulk energized electron population during the acceleration process. In contrast to other mechanisms which require special plasma properties, the EFI is an intrinsic feature of the acceleration process of the bulk electrons. Being present as a side effect in the flaring plasma, these waves can account for the acceleration of 3He and 4He while selectively enhancing 3He due to the spectral energy density built up from linear growth. Linearized kinetic theory, analytic models and test-particle simulations have been applied to investigate the ability of the waves to accelerate and fractionate. As waves grow in both directions parallel to the magnetic field, they can trap resonant ions and efficiently accelerate them to the highest energies. Plausible models have been found that can explain the observed energies, spectra and abundances of 3He and 4He.

  15. Relationship between acoustic body waves and in situ stresses around a borehole

    E-Print Network [OSTI]

    Rousseau, A

    2005-01-01

    This paper shows that there are three types of shape of acoustic body waves propagating inside competent and homogeneous formations penetrated by a borehole : simple, double, and resonant. This fact is connected to the modifications undergone by the area located around a well after drilling in relation to in situ state of stress. There are overstressed and understressed vertical cylindrical zones with "bubble-shaped" cross-sections, in which acoustic body waves are supposed to reflect. The horizontal size and the shape of the stress modified areas depend on the values of (K1+K2)/2 - with K1=SH/Sv (the overburden pressure) and K2=Sh/Sv -, that is to say on the in situ horizontal stress and the anisotropy of this stress. The calculation of the velocities of the P and S double waves allows us to evaluate the radial thicknesses of these stress modified areas. As their values are different according to whether they result from P or S waves, we propose an explanation based on their wavelengths. The comparisons with...

  16. Deformation fabrics of olivine in Val Malenco peridotite found in Italy and implications for the seismic anisotropy in the upper mantle

    E-Print Network [OSTI]

    Jung, Haemyeong

    for the interpretation of seismic data. Seismic polarization anisotropy in the upper mantle has been observed in many, seismic data (i.e., seismic anisotropy) have been interpreted on the basis of the type-A LPO of olivine al., 2004; Katayama and Karato, 2006); this has led to a new era for the interpretation of seismic

  17. Electrical anisotropy of mineralized and non mineralized rocks T.J. Katsube, M.E. Best*, and Jones, A.G., Geological Survey of Canada

    E-Print Network [OSTI]

    Jones, Alan G.

    PP 10.2 Electrical anisotropy of mineralized and non mineralized rocks T.J. Katsube, M.E. Best*, and Jones, A.G., Geological Survey of Canada Summary Significant electrical resistivity anisotropy, up to 1 to understand the electrical mechanisms involved in such anisotropic processes in order to provide information

  18. SOLITARY-WAVE AND MULTI-PULSED TRAVELING-WAVE ...

    E-Print Network [OSTI]

    1910-00-81

    ential equations which model waves in a horizontal water channel traveling in ... undisturbed water depth and ? lies in [0,1]. ..... We content ourselves with.

  19. Plane wave solution for elastic wave scattering by a heterogeneous ...

    E-Print Network [OSTI]

    2004-05-28

    tory ultrasonic transmission tests across a synthetic fracture with known, regular geometry, Myer et al. 19855 found good agreement between measured waves ...

  20. Wave Energy Converter Effects on Nearshore Wave Propagation

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

    Energy Converter Effects on Nearshore Wave Propagation Jesse Roberts 1 , Grace Chang *2 , Craig Jones *3 Sandia National Laboratories 1515 Eubank SE, Albuquerque, NM 87123 USA 1...

  1. Deep-water gravity waves: nonlinear theory of wave groups

    E-Print Network [OSTI]

    Mindlin, I M

    2014-01-01

    Nonlinear initial-boundary value problem on deep-water gravity waves of finite amplitude is solved approximately (up to small terms of higher order) assuming that the waves are generated by an initial disturbance to the water and the horizontal dimensions of the initially disturbed body of the water are much larger than the magnitude of the free surface displacement. A numerable set of specific free surface waves is obtained in closed form and it is shown that free surface waves produced by an arbitrary initial disturbance to the water is a combination (not superposition: the waves are nonlinear) of the specific waves. A set of dispersive wave packets is found with one-to-one correspondence between the packets and positive integers, say, packet numbers, such that any initial free surface displacement gradually disintegrates into a number (limited or unlimited, depending on initial conditions) of the wave packets. The greater the packet number, the shorter the wavelength of the packet's carrier wave component,...

  2. Catching a Wave: Innovative Wave Energy Device Surfs for Power...

    Office of Environmental Management (EM)

    and cost-effective electricity from clean energy resources, including water. Marine and hydrokinetic (MHK) technologies, which generate power from waves, tides, or...

  3. Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves

    E-Print Network [OSTI]

    Klein, Spencer

    2010-01-01

    and ?tting a straight line. Radio waves are refracted signi?We note that while radio waves are refracted downward inwaves, similar to radio waves, propagate with small (

  4. Mechanism of tailored magnetic anisotropy in amorphous Co{sub 68}Fe{sub 24}Zr{sub 8} thin films

    SciTech Connect (OSTI)

    Fu, Yu E-mail: cangcangzhulin@gmail.com; Meckenstock, R.; Farle, M.; Barsukov, I.; Lindner, J.; Raanaei, H.; Hjörvarsson, B.

    2014-02-17

    The mechanism of tailored magnetic anisotropy in amorphous Co{sub 68}Fe{sub 24}Zr{sub 8} thin films was investigated by ferromagnetic resonance (FMR) on samples deposited without an applied magnetic field, with an out-of-plane field and an in-plane field. Analysis of FMR spectra profiles, high frequency susceptibility calculations, and statistical simulations using a distribution of local uniaxial magnetic anisotropy reveal the presence of atomic configurations with local uniaxial anisotropy, of which the direction can be tailored while the magnitude remains at an intrinsically constant value of 3.0(2) kJ/m{sup 3}. The in-plane growth field remarkably sharpens the anisotropy distribution and increases the sample homogeneity. The results benefit designing multilayer spintronic devices based on highly homogeneous amorphous layers with tailored magnetic anisotropy.

  5. Determination of the Fe magnetic anisotropies and the CoO frozen spins in epitaxial CoO/Fe/Ag(001)

    SciTech Connect (OSTI)

    Meng, J. Li, Y.; Park, J. S.; Jenkins, C. A.; Arenholz, E.; Scholl, A.; Tan, A.; Son, H.; Zhao, H. W.; Hwang, Chanyong; Qiu, Z. Q.

    2011-04-28

    CoO/Fe/Ag(001) films were grown epitaxially and studied by X-ray Magnetic Circular Dichroism (XMCD) and X-ray Magnetic Linear Dichroism (XMLD). After field cooling along the Fe[100] axis to 80 K, exchange bias, uniaxial anisotropy, and 4-fold anisotropy of the films were determined by hysteresis loop and XMCD measurements by rotating the Fe magnetization within the film plane. The CoO frozen spins were determined by XMLD measurement as a function of CoO thickness.We find that among the exchange bias, uniaxial anisotropy, and 4-fold anisotropy, only the uniaxial magnetic anisotropy follows thickness dependence of the CoO frozen spins.

  6. Spin waves in the (

    SciTech Connect (OSTI)

    Lipscombe, O. J.; Chen, G. F.; Fang, Chen; Perring, T. G.; Abernathy, Douglas L; Christianson, Andrew D; Egami, Takeshi; Wang, Nanlin; Hu, Jiangping; Dai, Pengcheng

    2011-01-01

    We use neutron scattering to show that spin waves in the iron chalcogenide Fe{sub 1.05}Te display novel dispersion clearly different from both the first principles density functional calculations and recent observations in the related iron pnictide CaFe{sub 2}As{sub 2}. By fitting to a Heisenberg Hamiltonian, we find that although the nearest-neighbor exchange couplings in the two systems are quite different, their next-nearest-neighbor (NNN) couplings are similar. This suggests that superconductivity in the pnictides and chalcogenides share a common magnetic origin that is intimately associated with the NNN magnetic coupling between the irons.

  7. Elements of Radio Waves

    E-Print Network [OSTI]

    Frank G. Borg; Ismo Hakala; Jukka Määttälä

    2007-12-24

    We present a summary of the basic properties of the radio wave generation, propagation and reception, with a special attention to the gigahertz bandwidth region which is of interest for wireless sensor networks. We also present some measurement results which use the so-called RSSI indicator in order to track how the field strength varies with position and distance of the transceivers. We hope the paper may be useful to anyone who looks for a quick review of the fundamentals of electromagnetic theory with application to antennas.

  8. Guided acoustic wave inspection system

    DOE Patents [OSTI]

    Chinn, Diane J.

    2004-10-05

    A system for inspecting a conduit for undesirable characteristics. A transducer system induces guided acoustic waves onto said conduit. The transducer system detects the undesirable characteristics of the conduit by receiving guided acoustic waves that contain information about the undesirable characteristics. The conduit has at least two sides and the transducer system utilizes flexural modes of propagation to provide inspection using access from only the one side of the conduit. Cracking is detected with pulse-echo testing using one transducer to both send and receive the guided acoustic waves. Thinning is detected in through-transmission testing where one transducer sends and another transducer receives the guided acoustic waves.

  9. Wave Decay in MHD Turbulence

    E-Print Network [OSTI]

    Andrey Beresnyak; Alex Lazarian

    2008-05-06

    We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave decay in three-dimensional MHD turbulence, and discuss the influence of turbulent damping on the development of linear instabilities in the interstellar medium and on other important astrophysical processes.

  10. Random wave functions and percolation

    E-Print Network [OSTI]

    E. Bogomolny; C. Schmit

    2007-08-31

    Recently it was conjectured that nodal domains of random wave functions are adequately described by critical percolation theory. In this paper we strengthen this conjecture in two respects. First, we show that, though wave function correlations decay slowly, a careful use of Harris' criterion confirms that these correlations are unessential and nodal domains of random wave functions belong to the same universality class as non critical percolation. Second, we argue that level domains of random wave functions are described by the non-critical percolation model.

  11. Mechanical Anisotropy in Steels for Pipelines M. S. Joo, D.-W. Suh and H. K. D. H. Bhadeshia

    E-Print Network [OSTI]

    Cambridge, University of

    Mechanical Anisotropy in Steels for Pipelines M. S. Joo, D.-W. Suh and H. K. D. H. Bhadeshia March 2, 2012 Abstract There has been a huge expansion in the laying of pipelines for the transmission) 1305-1314 #12;Table 1: API specifications for common pipeline steels. The grade number corresponds

  12. 1 van der Waals Interactions on the Mesoscale: Open-Science 2 Implementation, Anisotropy, Retardation, and Solvent Effects

    E-Print Network [OSTI]

    Podgornik, Rudolf

    1 van der Waals Interactions on the Mesoscale: Open-Science 2 Implementation, Anisotropy Ljubljana, Slovenia 13 ABSTRACT: The self-assembly of heterogeneous mesoscale systems is mediated by 14 long-range interactions, including van der Waals forces. Diverse mesoscale 15 architectures, built of optically

  13. Anisotropy of Imbalanced Alfvenic Turbulence in Fast Solar Wind R. T. Wicks,1,* T. S. Horbury,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    energy to yet smaller scales [3­5]. In the fast wind, the turbulence is imbalanced: there is more power solar wind [8] and from numerical simulations [9] that balanced tur- bulence is made up of locallyAnisotropy of Imbalanced Alfve´nic Turbulence in Fast Solar Wind R. T. Wicks,1,* T. S. Horbury,1 C

  14. PHYSICAL REVIEW B 83, 134408 (2011) Size-dependent electric voltage controlled magnetic anisotropy in multiferroic heterostructures

    E-Print Network [OSTI]

    Chen, Long-Qing

    2011-01-01

    PHYSICAL REVIEW B 83, 134408 (2011) Size-dependent electric voltage controlled magnetic anisotropy) We present a phenomenological scheme to study the size-dependent electric voltage-controlled magnetic between the magnetic and electric polarizations.1­3 Of particular interest in the multiferroic

  15. Benefits of Carrier Pocket Anisotropy to Thermoelectric Performance: The case of p-type AgBiSe2

    SciTech Connect (OSTI)

    Parker, David S; May, Andrew F; Singh, David J

    2015-01-01

    We study theoretically the effects of anisotropy on the thermoelectric performance of p-type AgBiSe2. We present an apparent realization of the thermoelectric benefits of one-dimensional plate-like carrier pocket anisotropy in the valence band of this material. Based on first principles calculations we find a substantial anisotropy in the electronic structure, likely favorable for thermoelectric performance, in the valence bands of the hexagonal phase of the silver chalcogenide thermoelectric AgBiSe2, while the conduction bands are more isotropic, and in our experiments do not attain high performance. AgBiSe2 has already exhibited a ZT value of 1.5 in a high-temperature disordered fcc phase, but room-temperature performance has not been demonstrated. We develop a theory for the ability of anisotropy to decouple the density-of-states and conductivity effective masses, pointing out the influence of this effect in the high performance thermoelectrics Bi2Te3 and PbTe. From our first principles and Boltzmann transport calculations we find that p-type AgBiSe2 has substantial promise as a room temperature thermoelectric, and estimate its performance.

  16. Complex seismic anisotropy at the border of a very low velocity province at the base of the Earth's mantle

    E-Print Network [OSTI]

    Wen, Lianxing

    Complex seismic anisotropy at the border of a very low velocity province at the base of the Earth at distances between 90° and 150° by the seismic stations in three temporary broadband PASSCAL seismic arrays: the Kaapvaal seismic array (1997­1999), the Tanzania seismic array (1994­1995), and the Ethiopia/Kenya seismic

  17. Volcanoes generate devastating waves

    SciTech Connect (OSTI)

    Lockridge, P. (National Geophysical Data Center, Boulder, CO (USA))

    1988-01-01

    Although volcanic eruptions can cause many frightening phenomena, it is often the power of the sea that causes many volcano-related deaths. This destruction comes from tsunamis (huge volcano-generated waves). Roughly one-fourth of the deaths occurring during volcanic eruptions have been the result of tsunamis. Moreover, a tsunami can transmit the volcano's energy to areas well outside the reach of the eruption itself. Some historic records are reviewed. Refined historical data are increasingly useful in predicting future events. The U.S. National Geophysical Data Center/World Data Center A for Solid Earth Geophysics has developed data bases to further tsunami research. These sets of data include marigrams (tide gage records), a wave-damage slide set, digital source data, descriptive material, and a tsunami wall map. A digital file contains information on methods of tsunami generation, location, and magnitude of generating earthquakes, tsunami size, event validity, and references. The data can be used to describe areas mot likely to generate tsunamis and the locations along shores that experience amplified effects from tsunamis.

  18. THIRD MOMENTS AND THE ROLE OF ANISOTROPY FROM VELOCITY SHEAR IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Stawarz, Joshua E.; Vasquez, Bernard J.; Smith, Charles W.; Forman, Miriam A.; Klewicki, Joseph E-mail: Bernie.Vasquez@unh.edu E-mail: Miriam.Forman@sunysb.edu

    2011-07-20

    We have extended the recent analyses of magnetohydrodynamic third moments as they relate to the turbulent energy cascade in the solar wind to consider the effects of large-scale shear flows. Moments from a large set of Advanced Composition Explorer data have been taken, and chosen data intervals are characterized by the rate of change in the solar wind speed. Mean dissipation rates are obtained in accordance with the predictions of homogeneous shear-driven turbulence. Agreement with predictions is best made for rarefaction intervals where the solar wind speed is decreasing with time. For decreasing speed intervals, we find that the dissipation rates increase with increasing shear magnitude and that the shear-induced fluctuation anisotropy is consistent with a relatively small amount.

  19. Band-filling effect on magnetic anisotropy using a Green's function method

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

    Ke, Liqin; van Schilfgaarde, Mark

    2015-07-28

    We use an analytical model to describe the magnetocrystalline anisotropy energy (MAE) in solids as a function of band filling. The MAE is evaluated in second-order perturbation theory, which makes it possible to decompose the MAE into a sum of transitions between occupied and unoccupied pairs. The model enables us to characterize the MAE as a sum of contributions from different, often competing terms. The nitridometalates Li2[(Li1–xTx)N], with T= Mn, Fe, Co, Ni, provide a system where the model is very effective because atomiclike orbital characters are preserved and the decomposition is fairly clean. The model results are also comparedmore »against MAE evaluated directly from first-principles calculations for this system. Good qualitative agreement is found.« less

  20. Measurement of the large-scale anisotropy of the cosmic background radiation at 3mm

    SciTech Connect (OSTI)

    Epstein, G.L.

    1983-12-01

    A balloon-borne differential radiometer has measured the large-scale anisotropy of the cosmic background radiation (CBR) with high sensitivity. The antenna temperature dipole anistropy at 90 GHz (3 mm wavelength) is 2.82 +- 0.19 mK, corresponding to a thermodynamic anistropy of 3.48 +- mK for a 2.7 K blackbody CBR. The dipole direction, 11.3 +- 0.1 hours right ascension and -5.7/sup 0/ +- 1.8/sup 0/ declination, agrees well with measurements at other frequencies. Calibration error dominates magnitude uncertainty, with statistical errors on dipole terms being under 0.1 mK. No significant quadrupole power is found, placing a 90% confidence-level upper limit of 0.27 mK on the RMS thermodynamic quadrupolar anistropy. 22 figures, 17 tables.

  1. Time delay anisotropy in photoelectron emission from the isotropic ground state of helium

    E-Print Network [OSTI]

    Heuser, Sebastian; Cirelli, Claudio; Sabbar, Mazyar; Boge, Robert; Lucchini, Matteo; Gallmann, Lukas; Ivanov, Igor; Kheifets, Anatoli S; Dahlström, J Marcus; Lindroth, Eva; Argenti, Luca; Martín, Fernando; Keller, Ursula

    2015-01-01

    Time delays of electrons emitted from an isotropic initial state and leaving behind an isotropic ion are assumed to be angle-independent. Using an interferometric method involving XUV attosecond pulse trains and an IR probe field in combination with a detection scheme, which allows for full 3D momentum resolution, we show that time delays between electrons liberated from the $1s^{2}$ spherically symmetric ground state of He depend on the emission direction of the electrons with respect to the linear polarization axis of the ionizing XUV light. Such time delays can exhibit values as large as 60 attoseconds. With the help of refined theoretical models we can attribute the observed anisotropy to the interplay between different final quantum states, which arise naturally when two photons are involved in the photoionization process. Since most measurement techniques tracing attosecond electron dynamics have involved at least two photons so far, this is a general, significant, and initially unexpected effect that m...

  2. Dome-like variation of the superconducting gap anisotropy in Fe-based superconductors

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

    Prozorov, Ruslan; Cho, Kyuil; Kim, Hyong June; Tanatar, Makariy

    2013-07-17

    Experiments performed on different iron-based superconductors suggest a variety of possible structures of the superconducting energy gap, both nodeless and nodal. To understand the pairing mechanisms, it is important to identify common features in the behavior of different materials. Measurements of the temperature - dependent London penetration depth provide important information on the structure of the superconducting gap. We show that despite significant differences between different iron - based superconductors, there is a universal trend: the gap is least anisotropic at the optimal doping and its anisotropy increases upon the departure towards underdoped and overdoped ends of the ''superconducting dome''.more »This trend is not related to the presence of the long-range magnetic order in the underdoped state.« less

  3. The Effect of Weak Gravitational Lensing on the Cosmic Microwave Background Anisotropy: Flat versus Open Universes

    E-Print Network [OSTI]

    Enrique Martinez-Gonzalez; Jose L. Sanz; Laura Cayon

    1997-02-26

    We have studied the effect of gravitational lensing on the Cosmic Microwave Background (CMB) anisotropy in flat and open universes. We develop a formalism to calculate the changes on the radiation power spectrum induced by lensing in the Newtonian and synchronous-comoving gauges. The previously considered negligible contribution to the CMB radiation power spectrum of the anisotropic term of the lensing correlation is shown to be appreciable. However, considering the nonlinear evolution of the matter power spectrum produces only slight differences on the results based on linear evolution. The general conclusion for flat as well as open universes is that lensing slightly smoothes the radiation power spectrum. For a given range of multipoles the effect of lensing increases with Omega but for the same acoustic peak it decreases with $\\Omega$. The maximum contribution of lensing to the radiation power spectrum for $l\\leq 2000$ is $\\sim$ 5% for $\\Omega$ values in the range 0.1-1.

  4. Discrete wave turbulence of rotational capillary water waves

    E-Print Network [OSTI]

    Adrian Constantin; Elena Kartashova; Erik Wahlén

    2010-05-12

    We study the discrete wave turbulent regime of capillary water waves with constant non-zero vorticity. The explicit Hamiltonian formulation and the corresponding coupling coefficient are obtained. We also present the construction and investigation of resonance clustering. Some physical implications of the obtained results are discussed.

  5. Topological horseshoes in travelling waves of discretized nonlinear wave equations

    SciTech Connect (OSTI)

    Chen, Yi-Chiuan, E-mail: YCChen@math.sinica.edu.tw [Institute of Mathematics, Academia Sinica, Taipei 10617, Taiwan (China)] [Institute of Mathematics, Academia Sinica, Taipei 10617, Taiwan (China); Chen, Shyan-Shiou, E-mail: sschen@ntnu.edu.tw [Department of Mathematics, National Taiwan Normal University, Taipei 11677, Taiwan (China)] [Department of Mathematics, National Taiwan Normal University, Taipei 11677, Taiwan (China); Yuan, Juan-Ming, E-mail: jmyuan@pu.edu.tw [Department of Financial and Computational Mathematics, Providence University, Shalu, Taichung 43301, Taiwan (China)] [Department of Financial and Computational Mathematics, Providence University, Shalu, Taichung 43301, Taiwan (China)

    2014-04-15

    Applying the concept of anti-integrable limit to coupled map lattices originated from space-time discretized nonlinear wave equations, we show that there exist topological horseshoes in the phase space formed by the initial states of travelling wave solutions. In particular, the coupled map lattices display spatio-temporal chaos on the horseshoes.

  6. Interface boundary conditions for dynamic magnetization and spin wave dynamics in a ferromagnetic layer with the interface Dzyaloshinskii-Moriya interaction

    SciTech Connect (OSTI)

    Kostylev, M.

    2014-06-21

    In this work, we derive the interface exchange boundary conditions for the classical linear dynamics of magnetization in ferromagnetic layers with the interface Dzyaloshinskii-Moriya interaction (IDMI). We show that IDMI leads to pinning of dynamic magnetization at the interface. An unusual peculiarity of the IDMI-based pinning is that its scales as the spin-wave wave number. We incorporate these boundary conditions into an existing numerical model for the dynamics of the Damon-Eshbach spin wave in ferromagnetic films. IDMI affects the dispersion and the frequency non-reciprocity of the travelling Damon-Eshbach spin wave. For a broad range of film thicknesses L and wave numbers, the results of the numerical simulations of the spin wave dispersion are in a good agreement with a simple analytical expression, which shows that the contribution of IDMI to the dispersion scales as 1/L, similarly to the effect of other types of interfacial anisotropy. Suggestions to experimentalists how to detect the presence of IDMI in a spin wave experiment are given.

  7. WAVE-ENERGY DENSITY AND WAVE-MOMENTUM DENSITY OF EACH SPECIES OF A COLLISION-LESS PLASMA

    E-Print Network [OSTI]

    Cary, John R.

    2012-01-01

    A LiBRARY ANL WAVE-ENERGY DENSITY AND WAVE-MOMENTUM DENSITYof Califomia. To be in WAVE-ENERGY DENSITY AND WAVE~HOMENTUMExpress1ons for the wave-energy density and wave-momentum

  8. The constraints on power spectrum of relic gravitational waves from current observations of large-scale structure of the Universe

    E-Print Network [OSTI]

    B. Novosyadlyj; S. Apunevych

    2004-12-02

    We carry out the determination of the amplitude of relic gravitational waves power spectrum. Indirect best-fit technique was applied to compare observational data and theory predictions. As observations we have used data on large-scale structure (LSS) of the Universe and anisotropy of cosmic microwave background (CMB) temperature. The conventional inflationary model with 11 parameters has been investigated, all of them evaluated jointly. This approach gave us a possibility to find parameters of power spectrum of gravitational waves along with statistical errors. The main result consists in following: WMAP data on power spectrum of CMB temperature fluctuations along with LSS data prefer model with small amplitude of tensor mode power spectrum, close to zero. The upper limit for its amplitude at quadupole harmonics T/S=0.6 at 95% C.L.

  9. Wave Mechanics and the Fifth Dimension

    E-Print Network [OSTI]

    Paul S. Wesson; James M. Overduin

    2013-01-28

    Replacing 4D Minkowski space by 5D canonical space leads to a clearer derivation of the main features of wave mechanics, including the wave function and the velocity of de Broglie waves. Recent tests of wave-particle duality could be adapted to investigate whether de Broglie waves are basically 4D or 5D in nature.

  10. Ocean acoustic wave propagation and ray method correspondence: Internal wave fine structure

    E-Print Network [OSTI]

    Tomsovic, Steve

    Ocean acoustic wave propagation and ray method correspondence: Internal wave fine structure 2004 Acoustic wave fields propagating long ranges through the ocean are refracted As acoustic waves propagate long ranges through the deep ocean, they are refracted by inhomogeneities

  11. Using a Bore-Soliton-Splash to understand Rogue Waves, Tsunamis & Wave Energy

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    & new experiments, in portable BSS wave tank or Roombeek channel [7]. 7 New Wave Energy Device [2]. · Clarify connection Bore-Soliton-Splash with rogue waves and tsunamis. · New wave energy device

  12. Full wave simulations of fast wave heating losses in the scrape...

    Office of Scientific and Technical Information (OSTI)

    Full wave simulations of fast wave heating losses in the scrape-off layer of NSTX and NSTX-U Citation Details In-Document Search Title: Full wave simulations of fast wave heating...

  13. Design of Millimeter-Wave Power Ampliers in Silicon /

    E-Print Network [OSTI]

    Kalantari, Nader

    2013-01-01

    1.1 Millimeter-Wave Power Amplifier . . . . . . . . . .ported mm-wave power amplifiers. . . . . . . . . . . . . . .GHz Tapered Constructive Wave Power 3.1 Traveling Wave Power

  14. Spatial and temporal modulation of internal waves and thermohaline structure

    E-Print Network [OSTI]

    Cole, Sylvia T

    2010-01-01

    timescale, the internal wave energy cascade that concludes2 addresses the internal wave energy cascade and its spatialto as the internal wave energy cascade. Internal waves

  15. Geothermal Exploration with Visible through Long Wave Infrared...

    Open Energy Info (EERE)

    Wave Infrared Imaging Spectrometers Abstract Surface minerals of active geothermal systems have been mapped using visible-short wave infrared and mid wave and long wave imaging...

  16. Dissipation of parallel and oblique Alfv\\'en-cyclotron waves: implications for minor ion heating in the solar wind

    E-Print Network [OSTI]

    Maneva, Y G; Moya, Pablo S; Wicks, R; Poedts, S

    2015-01-01

    We perform 2.5D hybrid simulations with massless fluid electrons and kinetic particle-in-cell ions to study the temporal evolution of ion temperatures, temperature anisotropies and velocity distribution functions in relation to the dissipation and turbulent evolution of a broad-band spectrum of parallel and obliquely propagating Alfv\\'en-cyclotron waves. The purpose of this paper is to study the relative role of parallel versus oblique Alfv\\'en-cyclotron waves in the observed heating and acceleration of minor ions in the fast solar wind. We consider collisionless homogeneous multi-species plasma, consisting of isothermal electrons, isotropic protons and a minor component of drifting $\\alpha$ particles in a finite-$\\beta$ fast stream near the Earth. The kinetic ions are modeled by initially isotropic Maxwellian velocity distribution functions, which develop non-thermal features and temperature anisotropies when a broad-band spectrum of low-frequency non-resonant, $\\omega \\leq 0.34 \\Omega_p$, Alfv\\'en-cyclotron...

  17. Colliding axisymmetric pp-waves

    E-Print Network [OSTI]

    B. V. Ivanov

    1997-10-21

    An exact solution is found describing the collision of axisymmetric pp-waves with M=0. They are impulsive in character and their coordinate singularities become point curvature singularities at the boundaries of the interaction region. The solution is conformally flat. Concrete examples are given, involving an ultrarelativistic black hole against a burst of pure radiation or two colliding beam- like waves.

  18. Stratified Steady Periodic Water Waves

    E-Print Network [OSTI]

    Samuel Walsh

    2009-02-11

    This paper considers two-dimensional stratified water waves propagating under the force of gravity over an impermeable flat bed and with a free surface. We prove the existence of a global continuum of classical solutions that are periodic and traveling. These waves, moreover, can exhibit large density variation, speed and amplitude.

  19. Creating Wave-Focusing Materials

    E-Print Network [OSTI]

    A. G. Ramm

    2008-05-16

    Basic ideas for creating wave-focusing materials by injecting small particles in a given material are described. The number of small particles to be injected around any point is calculated. Inverse scattering problem with fixed wavenumber and fixed incident direction of the plane acoustic wave is formulated and solved.

  20. Estimation of wave run-up on smooth, impermeable slopes using the wave momentum flux parameter

    E-Print Network [OSTI]

    US Army Corps of Engineers

    Estimation of wave run-up on smooth, impermeable slopes using the wave momentum flux parameter-examines existing wave run-up data for regular, irregular and solitary waves on smooth, impermeable plane slopes. A simple physical argument is used to derive a new wave run-up equation in terms of a dimensionless wave

  1. Impact of non-hydrostatic effects and trapped lee waves on mountain wave drag

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Impact of non-hydrostatic effects and trapped lee waves on mountain wave drag in directionally effects and trapped lee waves on mountain wave drag in directionally sheared flow. Quarterly Journal;AcceptedArticle Impact of non-hydrostatic effects and trapped lee waves on mountain wave drag

  2. Application of wave generator theory to the development of a Wave Energy Converter

    E-Print Network [OSTI]

    Wood, Stephen L.

    Application of wave generator theory to the development of a Wave Energy Converter by Maila Sepri approve the attached thesis Application of wave generator theory to the development of a Wave Energy Application of wave generator theory to the development of a Wave Energy Converter by Maila Sepri Principal

  3. Plasma wave measurements with STEREO S/WAVES: Calibration, potential model, and preliminary results

    E-Print Network [OSTI]

    California at Berkeley, University of

    Plasma wave measurements with STEREO S/WAVES: Calibration, potential model, and preliminary results] The S/WAVES experiments on the two STEREO spacecraft measure waves, both in situ plasma waves and remotely generated waves such as Type II and Type III solar bursts. A part of the experiment is aimed

  4. Tube-wave seismic imaging

    DOE Patents [OSTI]

    Korneev, Valeri A. (Lafayette, CA); Bakulin, Andrey (Houston, TX)

    2009-10-13

    The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.

  5. Tube-wave seismic imaging

    DOE Patents [OSTI]

    Korneev, Valeri A [LaFayette, CA

    2009-05-05

    The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.

  6. Azimuthal Anisotropy Relative to the Participant Plane from AMPT in Central p+Au, d+Au, and $^{3}$He+Au Collisions at $\\sqrt{s_{NN}}=200$ GeV

    E-Print Network [OSTI]

    J. D. Orjuela Koop; A. Adare; D. McGlinchey; J. L. Nagle

    2015-07-28

    Recent data from p+p and p+Pb collisions at the Large Hadron Collider (LHC), and d+Au and $^3$He+Au collisions at the Relativistic Heavy Ion Collider (RHIC) reveal patterns that---when observed in the collision of heavy nuclei---are commonly interpreted as indicators of a locally equilibrated system in collective motion. The comparison of these data sets, including the forthcoming results from p+Au and p+Al collisions at RHIC, will help to elucidate the geometric dependence of such patterns. It has recently been shown that A-Multi-Phase-Transport-Model (AMPT) can describe some of these features in LHC data with a parton-parton scattering cross section comparable to that required to describe A+A data. In this paper, we extend these studies by incorporating a full wave function description of the $^3$He nucleus to calculate elliptical and triangular anisotropy moments $v_2$ and $v_3$ for p+Au, d+Au and $^3$He+Au collisions at the RHIC top energy of 200 GeV. We find reasonable agreement with the measured $v_2$ in d+Au and $^3$He+Au and $v_3$ in $^3$He+Au for transverse momentum ($p_{T}$) $\\lesssim$ 1 GeV/c, but underestimate these measurements for higher values of \\pt. We predict a pattern of coefficients ($v_{2}$, $v_{3}$) for \\pau, dominated by differences in the number of induced local hot spots (i.e. one, two, or three) arising from intrinsic geometry. Additionally, we examine how this substantial azimuthal anisotropy accrues during each individual evolutionary phase of the collision in the AMPT model. The possibility of a simultaneous description of RHIC- and LHC-energy data, the suite of different geometries, and high multiplicity p+p data is an exciting possibility for understanding the underlying physics in these systems.

  7. Electrostatic-plasma-wave energy flux

    E-Print Network [OSTI]

    Amendt, P.; Rostoker, N.

    1984-01-01

    would reduce cross- field wave-energy convection since theor cross-field leakage of wave energy are ap- that thefeature of cross-field wave-energy transport, previous con-

  8. Scholte waves generated by seafloor topography

    E-Print Network [OSTI]

    Zheng, Yingcai

    2012-01-01

    Seafloor topography can excite strong interface waves called Scholte waves that are often dispersive and characterized by slow propagation but large amplitude. This type of wave can be used to invert for near seafloor shear ...

  9. Microstructural Design for Stress Wave Energy Management /

    E-Print Network [OSTI]

    Tehranian, Aref

    2013-01-01

    Nasser, S. , 2010. Stress-wave energy management throughNemat-Nasser, Stress-wave energy management through materialS. , 2009. Acoustic wave-energy management in composite

  10. Electrostatic-plasma-wave energy flux

    E-Print Network [OSTI]

    Amendt, P.; Rostoker, N.

    1984-01-01

    would reduce cross- field wave-energy convection since theor cross-field leakage of wave energy are ap- that thecomposition of electrostatic-wave-energy field degrees of

  11. Microstructural Design for Stress Wave Energy Management /

    E-Print Network [OSTI]

    Tehranian, Aref

    2013-01-01

    mode of pressure wave and energy transfer into shearmode of pressure wave and energy transfer into shear mode ItNasser, S. , 2010. Stress-wave energy management through

  12. Deep-water gravity waves: theoretical estimating of wave parameters

    E-Print Network [OSTI]

    Mindlin, Ilia M

    2014-01-01

    This paper addresses deep-water gravity waves of finite amplitude generated by an initial disturbance to the water. It is assumed that the horizontal dimensions of the initially disturbed body of the water are much larger than the magnitude of the free surface displacement in the origin of the waves. Initially the free surface has not yet been displaced from its equilibrium position, but the velocity field has already become different from zero. This means that the water at rest initially is set in motion suddenly by an impulse. Duration of formation of the wave origin and the maximum water elevation in the origin are estimated using the arrival times of the waves and the maximum wave-heights at certain locations obtained from gauge records at the locations, and the distances between the centre of the origin and each of the locations. For points situated at a long distance from the wave origin, forecast is made for the travel time and wave height at the points. The forecast is based on the data recorded by th...

  13. Walking Wave as a Model of Particle

    E-Print Network [OSTI]

    A. V. Goryunov

    2012-05-02

    The concept of walking wave is introduced from classical relativistic positions. One- and three-dimensional walking waves considered with their wave equations and dispersion equations. It is shown that wave characteristics (de Broglie's and Compton's wavelengths) and corpuscular characteristics (energy-momentum vector and the rest mass) of particle may be expressed through parameters of walking wave. By that the new view on a number concepts of physic related with wave-particle duality is suggested.

  14. Magnetic anisotropy in Ta/CoFeB/MgO investigated by x-ray magnetic circular dichroism and first-principles calculation

    SciTech Connect (OSTI)

    Kanai, Shun; Tsujikawa, Masahito; Shirai, Masafumi; Miura, Yoshio; Matsukura, Fumihiro Ohno, Hideo

    2014-12-01

    We study the spin and orbital magnetic moments in Ta/Co{sub 0.4}Fe{sub 0.4}B{sub 0.2}/MgO by x-ray magnetic circular dichroism measurements as well as first-principles calculations, in order to clarify the origin of the perpendicular magnetic anisotropy. Both experimental and theoretical results show that orbital magnetic moment of Fe is more anisotropic than that of Co with respect to the magnetization direction. The anisotropy is larger for thinner CoFeB, indicating that Fe atoms at the interface with MgO contribute more than Co to the observed perpendicular magnetic anisotropy.

  15. Strain relaxation and enhanced perpendicular magnetic anisotropy in BiFeO{sub 3}:CoFe{sub 2}O{sub 4} vertically aligned nanocomposite thin films

    SciTech Connect (OSTI)

    Zhang, Wenrui; Jiao, Liang; Li, Leigang [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Jian, Jie; Khatkhatay, Fauzia; Chu, Frank [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843 (United States); Chen, Aiping [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843 (United States); Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Jia, Quanxi [Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); MacManus-Driscoll, Judith L. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Wang, Haiyan, E-mail: wangh@ece.tamu.edu [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843 (United States)

    2014-02-10

    Self-assembled BiFeO{sub 3}:CoFe{sub 2}O{sub 4} (BFO:CFO) vertically aligned nanocomposite thin films have been fabricated on SrTiO{sub 3} (001) substrates using pulsed laser deposition. The strain relaxation mechanism between BFO and CFO with a large lattice mismatch has been studied by X-ray diffraction and transmission electron microscopy. The as-prepared nanocomposite films exhibit enhanced perpendicular magnetic anisotropy as the BFO composition increases. Different anisotropy sources have been investigated, suggesting that spin-flop coupling between antiferromagnetic BFO and ferrimagnetic CFO plays a dominant role in enhancing the uniaxial magnetic anisotropy.

  16. Wave Propagation in Fractured Poroelastic Media

    E-Print Network [OSTI]

    One important mechanism in Biot media at seismic frequencies is wave-induced fluid flow generated by fast compressional waves at mesoscopic-scale ...

  17. A holographic model of d-wave superconductor vortices with Lifshitz scaling

    E-Print Network [OSTI]

    Hong Guo; Fu-Wen Shu; Jing-He Chen; Hui Li; Ze Yu

    2015-02-03

    We study analytically the $d$-wave holographic superconductors with Lifshitz scaling in the presence of external magnetic field. The vortex lattice solutions of the model have also been obtained with different Lifshitz scaling. Our results imply that holographic $d$-wave superconductor is indeed a type II one even for different Lifshitz scaling. This is the same as the conventional $d$-wave superconductors in the Ginzburg-Landau theory. Our results also indicate that the dynamical exponent $z$ has no effect to the shape of the vortex lattice even after higher order corrections (away from the phase transition point $B_c$) are included. However, it has effects on the upper critical magnetic field $B_{c_2}$ through the fact that a larger $z$ results in a smaller $B_{c_2}$ and therefore influences the size (characterized by $r_0\\equiv 1/\\sqrt{B_{c_2}}$) of the vortex lattices. Furthermore, close comparisons between our results and those of the Ginzburg-Landau theory reveal the fact that the upper critical magnetic field $B_{c_2}$ is inversely proportional to the square of the superconducting coherence length $\\xi$, regardless of the anisotropy between space and time.

  18. Nondestructive testing using stress waves: wave propagation in layered media 

    E-Print Network [OSTI]

    Ortega, Jose Alberto

    2013-02-22

    The use of stress waves in several civil engineering applications such as nondestructive testing of soil deposits or pavement systems has become extremely popular over the last few years. In all cases, a dynamic impulse is applied to the surface...

  19. Backreacting p-wave Superconductors

    E-Print Network [OSTI]

    Raúl E. Arias; Ignacio Salazar Landea

    2013-01-28

    We study the gravitational backreaction of the non-abelian gauge field on the gravity dual to a 2+1 p-wave superconductor. We observe that as in the $p+ip$ system a second order phase transition exists between a superconducting and a normal state. Moreover, we conclude that, below the phase transition temperature $T_c$ the lowest free energy is achieved by the p-wave solution. In order to probe the solution, we compute the holographic entanglement entropy. For both $p$ and $p+ip$ systems the entanglement entropy satisfies an area law. For any given entangling surface, the p-wave superconductor has lower entanglement entropy.

  20. Geometric phases of water waves

    E-Print Network [OSTI]

    Francesco Fedele

    2014-08-08

    Recently, Banner et al. (2014) highlighted a new fundamental property of open ocean wave groups, the so-called crest slowdown. For linear narrowband waves, this is related to the geometric and dynamical phase velocities $U_d$ and $U_g$ associated with the parallel transport through the principal fiber bundle of the wave motion with $\\mathit{U}(1)$ symmetry. The theoretical predictions are shown to be in fair agreement with ocean field observations, from which the average crest speed $c=U_d+U_g$ with $c/U_d\\approx0.8$ and $U_{g}/U_d\\approx-0.2$.

  1. The Wave of the Future 

    E-Print Network [OSTI]

    Swyden, Courtney

    2006-01-01

    stream_source_info The wave of the future.pdf.txt stream_content_type text/plain stream_size 10577 Content-Encoding ISO-8859-1 stream_name The wave of the future.pdf.txt Content-Type text/plain; charset=ISO-8859...-1 The Wave of the Future Story by Courtney Swyden THEWAVE OF THE FUTURE tx H2O | pg. 2 Plans use local involvement to enhance water quality Comprehensive watershed protection plans,outlining ways to preserve or restore water-sheds, are becoming a popular...

  2. Recirculation in multiple wave conversions

    SciTech Connect (OSTI)

    Brizard, A. J. [Department of Chemistry and Physics, Saint Michael's College, Colchester, Vermont 05439 (United States); Kaufman, A. N. [Department of Physics and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States); Tracy, E. R. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795 (United States)

    2008-08-15

    A one-dimensional multiple wave-conversion model is constructed that allows energy recirculation in ray phase space. Using a modular eikonal approach, the connection coefficients for this model are calculated by ray phase-space methods. Analytical results (confirmed numerically) show that all connection coefficients exhibit interference effects that depend on an interference phase, calculated from the coupling constants and the area enclosed by the intersecting rays. This conceptual model, which focuses on the topology of intersecting rays in phase space, is used to investigate how mode conversion between primary and secondary waves is modified by the presence of a tertiary wave.

  3. Magnetic and elastic anisotropy in magnetorheological elastomers using nickel-based nanoparticles and nanochains

    SciTech Connect (OSTI)

    Landa, Romina A.; Soledad Antonel, Paula; Ruiz, Mariano M.; Negri, R. Martín; Perez, Oscar E.; Butera, Alejandro; Jorge, Guillermo; Oliveira, Cristiano L. P.

    2013-12-07

    Nickel (Ni) based nanoparticles and nanochains were incorporated as fillers in polydimethylsiloxane (PDMS) elastomers and then these mixtures were thermally cured in the presence of a uniform magnetic field. In this way, macroscopically structured-anisotropic PDMS-Ni based magnetorheological composites were obtained with the formation of pseudo-chains-like structures (referred as needles) oriented in the direction of the applied magnetic field when curing. Nanoparticles were synthesized at room temperature, under air ambient atmosphere (open air, atmospheric pressure) and then calcined at 400?°C (in air atmosphere also). The size distribution was obtained by fitting Small Angle X-ray Scattering (SAXS) experiments with a polydisperse hard spheres model and a Schulz-Zimm distribution, obtaining a size distribution centered at (10.0?±?0.6) nm with polydispersivity given by ??=?(8.0?±?0.2) nm. The SAXS, X-ray powder diffraction, and Transmission Electron Microscope (TEM) experiments are consistent with single crystal nanoparticles of spherical shape (average particle diameter obtained by TEM: (12?±?1) nm). Nickel-based nanochains (average diameter: 360?nm; average length: 3??m, obtained by Scanning Electron Microscopy; aspect ratio?=?length/diameter ? 10) were obtained at 85?°C and ambient atmosphere (open air, atmospheric pressure). The magnetic properties of Ni-based nanoparticles and nanochains at room temperature are compared and discussed in terms of surface and size effects. Both Ni-based nanoparticles and nanochains were used as fillers for obtaining the PDMS structured magnetorheological composites, observing the presence of oriented needles. Magnetization curves, ferromagnetic resonance (FMR) spectra, and strain-stress curves of low filler's loading composites (2% w/w of fillers) were determined as functions of the relative orientation with respect to the needles. The results indicate that even at low loadings it is possible to obtain magnetorheological composites with anisotropic properties, with larger anisotropy when using nanochains. For instance, the magnetic remanence, the FMR field, and the elastic response to compression are higher when measured parallel to the needles (about 30% with nanochains as fillers). Analogously, the elastic response is also anisotropic, with larger anisotropy when using nanochains as fillers. Therefore, all experiments performed confirm the high potential of nickel nanochains to induce anisotropic effects in magnetorheological materials.

  4. Plasma waves driven by gravitational waves in an expanding universe

    E-Print Network [OSTI]

    D. B. Papadopoulos

    2002-05-22

    In a Friedmann-Robertson-Walker (FRW) cosmological model with zero spatial curvature, we consider the interaction of the gravitational waves with the plasma in the presence of a weak magnetic field. Using the relativistic hydromagnetic equations it is verified that large amplitude magnetosonic waves are excited, assuming that both, the gravitational field and the weak magnetic field do not break the homogeneity and isotropy of the considered FRW spacetime.

  5. Resonance Van Hove Singularities in Wave Kinetics

    E-Print Network [OSTI]

    Shi, Yi-Kang

    2015-01-01

    Wave kinetic theory has been developed to describe the statistical dynamics of weakly nonlinear, dispersive waves. However, we show that systems which are generally dispersive can have resonant sets of wave modes with identical group velocities, leading to a local breakdown of dispersivity. This shows up as a geometric singularity of the resonant manifold and possibly as an infinite phase measure in the collision integral. Such singularities occur widely for classical wave systems, including acoustical waves, Rossby waves, helical waves in rotating fluids, light waves in nonlinear optics and also in quantum transport, e.g. kinetics of electron-hole excitations (matter waves) in graphene. These singularities are the exact analogue of the critical points found by Van Hove in 1953 for phonon dispersion relations in crystals. The importance of these singularities in wave kinetics depends on the dimension of phase space $D=(N-2)d$ ($d$ physical space dimension, $N$ the number of waves in resonance) and the degree ...

  6. Effects of anisotropy on the performance characteristics of an axially laminated anisotropic-rotor synchronous reluctance motor drive system

    SciTech Connect (OSTI)

    Isaac, F.N.; Arkadan, A.A.; Russell, A.A. [Marquette Univ., Milwaukee, WI (United States)] [Marquette Univ., Milwaukee, WI (United States); El-Antably, A.

    1998-09-01

    In the last few years, increased attention has been paid to the performance characterization and evaluation of the performance of synchronous reluctance machines. Extensive research has concentrated on different rotor structures in order to achieve high performance variable speed drives for applications such as electric vehicles. The effects of accounting for anisotropy on the performance characteristics of Axially Laminated Anisotropic (ALA) rotor Synchronous Reluctance Motor (SynRM) drive systems are studied. These effects are evaluated from the simulations of a computer aided model. The model is based on the use of an iterative approach which indirectly couples a two dimensional (2D) nonlinear finite element (FE) model, which accounts for anisotropy, to a state space model describing the SynRM drive system. The simulation results are also validated by comparison to test data of a prototype ALA rotor SynRM drive system.

  7. Generation of steep phase anisotropy with zero-backscattering by arrays of coupled dielectric nano-resonators

    SciTech Connect (OSTI)

    Wang, Feng; Wei, Qi-Huo; Htoon, Han

    2014-09-22

    The interaction of light with high-permittivity dielectric nano-resonators can lead to zero-backscattering (i.e., full transmission), attributed to the simultaneous excitation of electric and magnetic dipolar modes in these resonators. In this paper, we numerically demonstrate that 2-dimensional Si nanocuboid arrays with anisotropic periodicity and finely tuned cuboid height can generate up to 2? optical phase anisotropy with zero-backscattering. Especially, by introducing strong Fano-type coupling into unit cells of the array, the induced phase anisotropy becomes ultra-steep with excitation wavelength. These special optical properties promise applications in various transmissive photonic devices, and we discuss their potential applications in transmissive polarization conversion and sensing.

  8. Thickness effect on stress-induced exchange anisotropy of NiFeNiFeMn Chih-Huang Lai,a)

    E-Print Network [OSTI]

    Huang, Jung-Chun

    of attention due to its application for spin-valve read heads. Conventionally, ex- change anisotropy cleaner. They were then outgassed at 1050 °C for 1 h in the MBE chamber. The buffer layer of 20 nm Mo

  9. Measurement of the azimuthal anisotropy for charged particle production in ?s[subscript NN]=2.76 TeV lead-lead collisions with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    Differential measurements of charged particle azimuthal anisotropy are presented for lead-lead collisions at ?s[subscript NN]=2.76 TeV with the ATLAS detector at the LHC, based on an integrated luminosity of approximately ...

  10. Identified particle production, azimuthal anisotropy, and interferometry measurements in Au+Au collisions at [sqrt]sNN=9.2 GeV

    E-Print Network [OSTI]

    Surrow, Bernd

    We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au+Au collisions below the nominal injection energy at the BNL Relativistic Heavy-Ion Collider (RHIC) ...

  11. Wave Energy Extraction from buoys

    E-Print Network [OSTI]

    Garnaud, Xavier

    2009-01-01

    Different types of Wave Energy Converters currently tested or under development are using the vertical movement of floating bodies to generate electricity. For commercial applications, arrays have to be considered in order ...

  12. Gravitational waves: a foundational review

    E-Print Network [OSTI]

    J. G. Pereira

    2015-05-27

    The standard linear approach to the gravitational waves theory is critically reviewed. Contrary to the prevalent understanding, it is pointed out that this theory contains many conceptual and technical obscure issues that require further analysis.

  13. A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abreu, P.; ,

    2012-01-01

    Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three methods can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. Using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ..., 110 highest energy events with a corresponding minimum energy threshold of about 51 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.

  14. Measurement of J/? Azimuthal Anisotropy in Au+Au Collisions at ?sNN=200 GeV

    SciTech Connect (OSTI)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bruna, E.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Cai, X. Z.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chung, P.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Ding, F.; Dion, A.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elnimr, M.; Engelage, J.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Gliske, S.; Grebenyuk, O. G.; Grosnick, D.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L-X.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jena, C.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Kikola, D. P.; Kiryluk, J.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Lu, Y.; Luo, X.; Luszczak, A.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Mioduszewski, S.; Mitrovski, M. K.; Mohammed, Y.; Mohanty, B.; Mondal, M. M.; Munhoz, M. G.; Mustafa, M. K.; Naglis, M.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Novak, J.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Powell, C. B.; Pruneau, C.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, B.; Schmitz, N.; Schuster, T. R.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shao, M.; Sharma, B.; Sharma, M.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yang, Y.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I-K.; Zawisza, M.; Zbroszczyk, H.; Zhang, J. B.; Zhang, S.; Zhang, X. P.; Zhang, Y.

    2013-08-02

    The measurement of J/? azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at ?sNN>/sub>=200 GeV. The measured J/? elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/? particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

  15. The effects of structure anisotropy on lensing observables in an exact general relativistic setting for precision cosmology

    SciTech Connect (OSTI)

    Troxel, M. A.; Ishak, Mustapha; Peel, Austin, E-mail: troxel@utdallas.edu, E-mail: mishak@utdallas.edu, E-mail: austin.peel@utdallas.edu [Department of Physics, The University of Texas at Dallas, Richardson, TX 75080 (United States)

    2014-03-01

    The study of relativistic, higher order, and nonlinear effects has become necessary in recent years in the pursuit of precision cosmology. We develop and apply here a framework to study gravitational lensing in exact models in general relativity that are not restricted to homogeneity and isotropy, and where full nonlinearity and relativistic effects are thus naturally included. We apply the framework to a specific, anisotropic galaxy cluster model which is based on a modified NFW halo density profile and described by the Szekeres metric. We examine the effects of increasing levels of anisotropy in the galaxy cluster on lensing observables like the convergence and shear for various lensing geometries, finding a strong nonlinear response in both the convergence and shear for rays passing through anisotropic regions of the cluster. Deviation from the expected values in a spherically symmetric structure are asymmetric with respect to path direction and thus will persist as a statistical effect when averaged over some ensemble of such clusters. The resulting relative difference in various geometries can be as large as approximately 2%, 8%, and 24% in the measure of convergence (1??) for levels of anisotropy of 5%, 10%, and 15%, respectively, as a fraction of total cluster mass. For the total magnitude of shear, the relative difference can grow near the center of the structure to be as large as 15%, 32%, and 44% for the same levels of anisotropy, averaged over the two extreme geometries. The convergence is impacted most strongly for rays which pass in directions along the axis of maximum dipole anisotropy in the structure, while the shear is most strongly impacted for rays which pass in directions orthogonal to this axis, as expected. The rich features found in the lensing signal due to anisotropic substructure are nearly entirely lost when one treats the cluster in the traditional FLRW lensing framework. These effects due to anisotropic structures are thus likely to impact lensing measurements and must be fully examined in an era of precision cosmology.

  16. Measurement of J/? Azimuthal Anisotropy in Au+Au Collisions at ?sNN=200 GeV

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

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; et al

    2013-08-02

    The measurement of J/? azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at ?sNN>/sub>=200 GeV. The measured J/? elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/? particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

  17. Direct Drive Wave Energy Buoy

    SciTech Connect (OSTI)

    Rhinefrank, Kenneth E.; Lenee-Bluhm, Pukha; Prudell, Joseph H.; Schacher, Alphonse A.; Hammagren, Erik J.; Zhang, Zhe

    2013-07-29

    The most prudent path to a full-scale design, build and deployment of a wave energy conversion (WEC) system involves establishment of validated numerical models using physical experiments in a methodical scaling program. This Project provides essential additional rounds of wave tank testing at 1:33 scale and ocean/bay testing at a 1:7 scale, necessary to validate numerical modeling that is essential to a utility-scale WEC design and associated certification.

  18. Pressure-Induced Enhanced Magnetic Anisotropy in Mn(N(CN)2)2

    SciTech Connect (OSTI)

    Quintero, P. A. [University of Florida, Gainesville; Rajan, D. [University of Florida, Gainesville; Peprah, M. K. [University of Florida, Gainesville; Brinzari, T. V. [University of Florida, Gainesville; Fishman, Randy Scott [ORNL; Talham, Daniel R. [University of Florida, Gainesville; Meisel, Mark W. [University of Florida, Gainesville

    2015-01-01

    Using DC and AC magnetometry, the pressure dependence of the magnetization of the threedimensional antiferromagnetic coordination polymer Mn(N(CN)2)2 was studied up to 12 kbar and down to 8 K. The magnetic transition temperature, Tc, increases dramatically with applied pressure (P), where a change from Tc(P = ambient) = 16:0 K to Tc(P = 12:1 kbar) = 23:5 K was observed. In addition, a marked difference in the magnetic behavior is observed above and below 7.1 kbar. Specifically, for P < 7:1 kbar, the differences between the field-cooled and zero-field-cooled (fc-zfc) magnetizations, the coercive field, and the remanent magnetization decrease with increasing pressure. However, for P > 7:1 kbar, the behavior is inverted. Additionally, for P > 8:6 kbar, minor hysteresis loops are observed. All of these effects are evidence of the increase of the superexchange interaction and the appearance of an enhanced exchange anisotropy with applied pressure.

  19. Strain control magnetocrystalline anisotropy of Ta/FeCo/MgO heterostructures

    SciTech Connect (OSTI)

    Ong, P. V.; Kioussis, Nicholas; Amiri, P. Khalili; Wang, K. L.; Carman, Gregory P.

    2015-05-07

    Using ab initio electronic structure calculations, we have investigated the effect of epitaxial strain on magnetocrystalline anisotropy (MCA) of Ta/FeCo/MgO heterostructure. At small expansive strains on the FeCo layer, the system exhibits perpendicular MCA (PMA). Strain not only has a profound effect on the value of MCA but also induces a switching of magnetic easy axis. Analysis of the energy- and k-resolved distribution of orbital characters of the minority-spin band reveals that a significant contribution to PMA at zero strain arises from the spin-orbit coupling between occupied d{sub x{sup 2}?y{sup 2}} and unoccupied d{sub xy} states, derived from Fe at the FeCo/MgO interface. The strain effect is attributed to strain-induced shifts of spin-orbit coupled d-states. Our work demonstrates that strain engineering can open a viable pathway towards tailoring magnetic properties for spintronic applications.

  20. Axion decay and anisotropy of near-IR extragalactic background light

    E-Print Network [OSTI]

    Gong, Yan; Mitchell-Wynne, Ketron; Chen, Xuelei; Zemcov, Michael; Smidt, Joseph

    2015-01-01

    The extragalactic background light is expected to be comprised of the cumulative radiation from all galaxies and active galactic nuclei over the cosmic history. In addition to point sources, EBL also contains information from diffuse sources of radiation. An example is the intra-halo light, associated with diffuse stars in dark matter halos resulting from galaxy mergers and tidal interactions, identified based on measurements involving the angular power spectrum of infrared background anisotropies. The angular power spectra of the near-infrared intensities could still contain additional signals and a complete understanding of the nature of the IR background is still lacking in the literature. Here we explore the constraints that can be placed on the decay products associated with particle decays, especially candidate dark matter models involving axions that trace dark matter halos of galaxies. Axions with a mass around a few eV will decay via two photons with wavelengths in the near-IR band, and will leave a ...

  1. On the dipole straylight contamination in spinning space missions dedicated to CMB anisotropy

    E-Print Network [OSTI]

    Carlo Burigana; Alessandro Gruppuso; Fabio Finelli

    2006-07-21

    We present an analysis of the dipole straylight contamination (DSC) for spinning space-missions designed to measure CMB anisotropies. Although this work is mainly devoted to the {\\sc Planck} project, it is relatively general and allows to focus on the most relevant DSC implications. We first study a simple analytical model for the DSC in which the pointing direction of the main spillover can be assumed parallel or not to the spacecraft spin axis direction and compute the time ordered data and map. The map is then analysed paying particular attention to the DSC of the low multipole coefficients of the map. Through dedicated numerical simulations we verify the analytical results and extend the analysis to higher multipoles and to more complex (and realistic) cases by relaxing some of the simple assumptions adopted in the analytical approach. We find that the systematic effect averages out in an even number of surveys, except for a contamination of the dipole itself that survives when spin axis and spillover directions are not parallel and for a contamination of the other multipoles in the case of complex scanning strategies. In particular, the observed quadrupole can be affected by the DSC in an odd number of surveys or in the presence of survey uncompleteness or over-completeness. Various aspects relevant in CMB space projects (such as implications for calibration, impact on polarization measurements, accuracy requirement in the far beam knowledge for data analysis applications, scanning strategy dependence) are discussed.

  2. The impact of dipole straylight contamination on the alignment of low multipoles of CMB anisotropies

    E-Print Network [OSTI]

    A. Gruppuso; C. Burigana; F. Finelli

    2007-01-10

    We estimate the impact of the Dipole Straylight Contamination (DSC) for the {\\it Planck} satellite on the alignments of vectors associated to the low multipoles of the pattern of the cosmic microwave background (CMB) anisotropies. In particular we study how the probability distributions of eighteen estimators for the alignments change when DSC is taken into account. We find that possible residual DSC should leave a non-negligible impact on low multipole alignments for effective values of the fractional far sidelobe integrated response, $p$, larger than $\\sim {\\rm few} \\times 10^{-3}$. The effect is strongly dependent on the intrinsic sky amplitude and weakly dependent on the considered scanning strategy. We find a decrease of the alignment probability between the quadrupole and the dipole and an increase of the alignment probability between the hexadecapole and the dipole (larger is the intrinsic sky amplitude and lower is the contamination). The remaining estimators do not exhibit clear signatures, except, in some cases, considering the largest values of $p$ and the lowest sky amplitudes. Provided that the real sidelobes of the {\\it Planck} receivers in flight conditions will correspond to $p \\lsim {\\rm few} \\times 10^{-3}$, as realistically expected at least in the cosmological frequency channels, and will be known with accuracies better than $\\sim {\\rm few} \\times 10$% allowing for a suitable cleaning during data reduction, {\\it Planck} will be very weakly affected from DSC on the alignments of low multipoles.

  3. Azimuthal anisotropy in U+U and Au+Au collisions at RHIC

    E-Print Network [OSTI]

    Adamczyk, L; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Bairathi, V; Banerjee, A; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandin, A V; Bunzarov, I; Butterworth, J; Caines, H; Sánchez, M Calderón de la Barca; Campbell, J M; Cebra, D; Cervantes, M C; Chakaberia, I; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, J H; Chen, X; Cheng, J; Cherney, M; Christie, W; Contin, G; Crawford, H J; Das, S; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, C E; Fulek, L; Gagliardi, C A; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Hamad, A; Hamed, A; Haque, R; Harris, J W; He, L; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Jiang, K; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Kochenda, L; Koetke, D D; Kollegger, T; Kosarzewski, L K; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Li, X; Li, Z M; Li, Y; Li, W; Li, C; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, R; Ma, Y G; Ma, L; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; Meehan, K; Minaev, N G; Mioduszewski, S; Mishra, D; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V; Olvitt, D; Page, B S; Pak, R; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlik, B; Pei, H; Perkins, C; Peterson, A; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Posik, M; Poskanzer, A M; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, M K; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Sikora, R; Simko, M; Skoby, M J; Smirnov, N; Smirnov, D; Song, L; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stepanov, M; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Summa, B; Sun, Z; Sun, X M; Sun, Y; Sun, X; Surrow, B; Svirida, N; Szelezniak, M A; Tang, Z; Tang, A H; Tarnowsky, T; Tawfik, A; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Tripathy, S K; Trzeciak, B A; Tsai, O D; Ullrich, T; Underwood, D G; Upsal, I; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wang, G; Wang, H; Wang, J S; Wang, Y; Wang, F; Webb, J C; Webb, G; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z G; Xie, W; Xin, K; Xu, Y F; Xu, Q H; Xu, H; Xu, N; Xu, Z; Yang, Y; Yang, C; Yang, S; Yang, Q; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I -K; Yu, N; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, Z; Zhang, J; Zhang, S; Zhang, X P; Zhang, Y; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M

    2015-01-01

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, $v_2\\{2\\}$ and $v_2\\{4\\}$, for charged hadrons from U+U collisions at $\\sqrt{s_{\\rm NN}}$ = 193 GeV and Au+Au collisions at $\\sqrt{s_{\\rm NN}}$ = 200 GeV. Nearly fully overlapping collisions are selected based on the amount of energy deposited by spectators in the STAR Zero Degree Calorimeters (ZDCs). Within this sample, the observed dependence of $v_2\\{2\\}$ on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. An initial-state model with gluon saturation describes the slope of $v_2\\{2\\}$ as a function of multiplicity in central collisions better than one based on Glauber with a two-component multiplicity model.

  4. Azimuthal anisotropy in U+U and Au+Au collisions at RHIC

    E-Print Network [OSTI]

    STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; A. Aparin; D. Arkhipkin; E. C. Aschenauer; G. S. Averichev; V. Bairathi; A. Banerjee; R. Bellwied; A. Bhasin; A. K. Bhati; P. Bhattarai; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; J. Bouchet; A. V. Brandin; I. Bunzarov; J. Butterworth; H. Caines; M. Calderón de la Barca Sánchez; J. M. Campbell; D. Cebra; M. C. Cervantes; I. Chakaberia; P. Chaloupka; Z. Chang; S. Chattopadhyay; J. H. Chen; X. Chen; J. Cheng; M. Cherney; W. Christie; G. Contin; H. J. Crawford; S. Das; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; A. A. Derevschikov; B. di Ruzza; L. Didenko; C. Dilks; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; J. Engelage; G. Eppley; R. Esha; O. Evdokimov; O. Eyser; R. Fatemi; S. Fazio; P. Federic; J. Fedorisin; Z. Feng; P. Filip; Y. Fisyak; C. E. Flores; L. Fulek; C. A. Gagliardi; D. Garand; F. Geurts; A. Gibson; M. Girard; L. Greiner; D. Grosnick; D. S. Gunarathne; Y. Guo; A. Gupta; S. Gupta; W. Guryn; A. Hamad; A. Hamed; R. Haque; J. W. Harris; L. He; S. Heppelmann; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; H. Z. Huang; X. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; H. Jang; K. Jiang; E. G. Judd; S. Kabana; D. Kalinkin; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; Z. H. Khan; D. P. Kikola; I. Kisel; A. Kisiel; L. Kochenda; D. D. Koetke; T. Kollegger; L. K. Kosarzewski; A. F. Kraishan; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; R. A. Kycia; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; X. Li; Z. M. Li; Y. Li; W. Li; X. Li; C. Li; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; M. Lomnitz; R. S. Longacre; X. Luo; G. L. Ma; R. Ma; Y. G. Ma; L. Ma; N. Magdy; R. Majka; A. Manion; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; K. Meehan; N. G. Minaev; S. Mioduszewski; D. Mishra; B. Mohanty; M. M. Mondal; D. A. Morozov; M. K. Mustafa; B. K. Nandi; Md. Nasim; T. K. Nayak; G. Nigmatkulov; L. V. Nogach; S. Y. Noh; J. Novak; S. B. Nurushev; G. Odyniec; A. Ogawa; K. Oh; V. Okorokov; D. Olvitt Jr.; B. S. Page; R. Pak; Y. X. Pan; Y. Pandit; Y. Panebratsev; B. Pawlik; H. Pei; C. Perkins; A. Peterson; P. Pile; M. Planinic; J. Pluta; N. Poljak; K. Poniatowska; J. Porter; M. Posik; A. M. Poskanzer; J. Putschke; H. Qiu; A. Quintero; S. Ramachandran; R. Raniwala; S. Raniwala; R. L. Ray; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; A. Roy; L. Ruan; J. Rusnak; O. Rusnakova; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; J. Sandweiss; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; W. B. Schmidke; N. Schmitz; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; P. V. Shanmuganathan; M. Shao; M. K. Sharma; B. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. Sikora; M. Simko; M. J. Skoby; N. Smirnov; D. Smirnov; L. Song; P. Sorensen; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; M. Stepanov; R. Stock; M. Strikhanov; B. Stringfellow; M. Sumbera; B. Summa; Z. Sun; X. M. Sun; Y. Sun; X. Sun; B. Surrow; N. Svirida; M. A. Szelezniak; Z. Tang; A. H. Tang; T. Tarnowsky; A. Tawfik; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; S. K. Tripathy; B. A. Trzeciak; O. D. Tsai; T. Ullrich; D. G. Underwood; I. Upsal; G. Van Buren; G. van Nieuwenhuizen; M. Vandenbroucke; R. Varma; A. N. Vasiliev; R. Vertesi; F. Videbæk; Y. P. Viyogi; S. Vokal; S. A. Voloshin; A. Vossen; G. Wang; H. Wang; J. S. Wang; Y. Wang; Y. Wang; F. Wang; J. C. Webb; G. Webb; L. Wen; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. G. Xiao; W. Xie; K. Xin; Y. F. Xu; Q. H. Xu; H. Xu; N. Xu; Z. Xu; Y. Yang; C. Yang; S. Yang; Y. Yang; Q. Yang; Z. Ye; P. Yepes; L. Yi; K. Yip; I. -K. Yoo; N. Yu; H. Zbroszczyk; W. Zha; J. B. Zhang; Z. Zhang; J. Zhang; S. Zhang; X. P. Zhang; J. Zhang; Y. Zhang; J. Zhao; C. Zhong; L. Zhou; X. Zhu; Y. Zoulkarneeva; M. Zyzak

    2015-05-28

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, $v_2\\{2\\}$ and $v_2\\{4\\}$, for charged hadrons from U+U collisions at $\\sqrt{s_{\\rm NN}}$ = 193 GeV and Au+Au collisions at $\\sqrt{s_{\\rm NN}}$ = 200 GeV. Nearly fully overlapping collisions are selected based on the amount of energy deposited by spectators in the STAR Zero Degree Calorimeters (ZDCs). Within this sample, the observed dependence of $v_2\\{2\\}$ on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. An initial-state model with gluon saturation describes the slope of $v_2\\{2\\}$ as a function of multiplicity in central collisions better than one based on Glauber with a two-component multiplicity model.

  5. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abreu, P

    2011-06-17

    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

  6. MICROWAVE EMISSION FROM THE EDGEWORTH-KUIPER BELT AND THE ASTEROID BELT CONSTRAINED FROM THE WILKINSON MICROWAVE ANISOTROPY PROBE

    SciTech Connect (OSTI)

    Ichikawa, Kazuhide; Fukugita, Masataka [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582 (Japan)

    2011-08-01

    Objects in the Edgeworth-Kuiper Belt and the main asteroid belt should emit microwaves that may give rise to extra anisotropy signals in the multipole of the cosmic microwave background (CMB) experiment. Constraints are derived from the absence of positive detection of such anisotropies for l {approx}< 50, meaning the total mass of Edgeworth-Kuiper Belt objects is smaller than 0.2 M{sub +}. This limit is consistent with the mass extrapolated from the observable population with the size of a {approx}> 15 km, assuming that the small-object population follows the power law in size dN/da {approx} a{sup -q} with the canonical index expected for collisional equilibrium, q {approx_equal} 3.5, with which 23% of the mass is ascribed to objects smaller than are observationally accessible down to grains. A similar argument applied to the main asteroid belt indicates that the grain population should not increase more quickly than q {approx_equal} 3.6 toward smaller radii, if the grain population follows the power law that continues to observed asteroids with larger radii. Both cases are at or only slightly above the limit that can be physically significant, implying the importance of further tightening the CMB anisotropy limit, which may be attained with observation at higher radio frequencies.

  7. DIFFUSING ACOUSTIC WAVE TRANSPORT AND SPECTROSCOPY

    E-Print Network [OSTI]

    Page, John

    1 Chapter DIFFUSING ACOUSTIC WAVE TRANSPORT AND SPECTROSCOPY J.H. PAGE, M.L. COWAN Dept. of Physics waves, multiple scattering, energy velocity, Diffusing Acoustic Wave Spectroscopy. Abstract the diffusive transport of ultrasonic waves, and then describe a new ultrasonic technique, Diffusing Acoustic

  8. Steady water waves with multiple critical layers

    E-Print Network [OSTI]

    Mats Ehrnström; Joachim Escher; Erik Wahlén

    2011-04-01

    We construct small-amplitude periodic water waves with multiple critical layers. In addition to waves with arbitrarily many critical layers and a single crest in each period, two-dimensional sets of waves with several crests and troughs in each period are found. The setting is that of steady two-dimensional finite-depth gravity water waves with vorticity.

  9. Temperature dependence of magnetization and anisotropy in uniaxial NiFe?O? nanomagnets: Deviation from the Callen-Callen power law

    SciTech Connect (OSTI)

    Chatterjee, Biplab K.; Ghosh, C. K. [School of Materials Science and Nanotechnology, Jadavpur University, Jadavpur, Kolkata 700032 (India); Chattopadhyay, K. K., E-mail: kalyan-chattopadhyay@yahoo.com [School of Materials Science and Nanotechnology, Jadavpur University, Jadavpur, Kolkata 700032 (India); Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Jadavpur, Kolkata 700032 (India)

    2014-10-21

    The thermal variation of magnetic anisotropy (K) and saturation magnetization (M{sub S}) for uniaxial nickel ferrite (NiFe?O?) nanomagnets are investigated. Major magnetic hysteresis loops are measured for the sample at temperatures over the range 5–280?K using a vibrating sample magnetometer. The high-field regimes of the hysteresis loops are modeled using the law of approach to saturation, based on the assumption that at sufficiently high field only direct rotation of spin-moment take place, with an additional forced magnetization term that is linear with applied field. The uniaxial anisotropy constant K is calculated from the fitting of the data to the theoretical equation. As temperature increases from 5?K to 280?K, a 49% reduction of K, accompanied by an 85% diminution of M{sub S} is observed. Remarkably, K is linearly proportional to M{sub S}?.? in the whole temperature range violating the existing theoretical model by Callen and Callen. The unusual power-law behavior for the NiFe?O? uniaxial nanomagnets is ascribed to the non-negligible contributions from inter-sublattice pair interactions, Neel surface anisotropy, and higher order anisotropies. A complete realization of the unusual anisotropy-magnetization scaling behavior for nanoscale two-sublattice magnetic materials require a major modification of the existing theory by considering the exact mechanism of each contributions to the effective anisotropy.

  10. Stress channelling in extreme couple-stress materials Part I: Strong ellipticity, wave propagation, ellipticity, and discontinuity relations

    E-Print Network [OSTI]

    Panos A. Gourgiotis; Davide Bigoni

    2015-12-04

    Materials with extreme mechanical anisotropy are designed to work near a material instability threshold where they display stress channelling and strain localization, effects that can be exploited in several technologies. Extreme couple stress solids are introduced and for the first time systematically analyzed in terms of several material instability criteria: positive-definiteness of the strain energy (implying uniqueness of the mixed b.v.p.), strong ellipticity (implying uniqueness of the b.v.p. with prescribed kinematics on the whole boundary), plane wave propagation, ellipticity, and the emergence of discontinuity surfaces. Several new and unexpected features are highlighted: (i.) Ellipticity is mainly dictated by the 'Cosserat part' of the elasticity and (ii.) its failure is shown to be related to the emergence of discontinuity surfaces; (iii.) Ellipticity and wave propagation are not interdependent conditions (so that it is possible for waves not to propagate when the material is still in the elliptic range and, in very special cases, for waves to propagate when ellipticity does not hold). The proof that loss of ellipticity induces stress channelling, folding and faulting of an elastic Cosserat continuum (and the related derivation of the infinite-body Green's function under antiplane strain conditions) is deferred to Part II of this study.

  11. Stress channelling in extreme couple-stress materials Part I: Strong ellipticity, wave propagation, ellipticity, and discontinuity relations

    E-Print Network [OSTI]

    Panos A. Gourgiotis; Davide Bigoni

    2015-09-22

    Materials with extreme mechanical anisotropy are designed to work near a material instability threshold where they display stress channelling and strain localization, effects that can be exploited in several technologies. Extreme couple stress solids are introduced and for the first time systematically analyzed in terms of several material instability criteria: positive-definiteness of the strain energy (implying uniqueness of the mixed b.v.p.), strong ellipticity (implying uniqueness of the b.v.p. with prescribed kinematics on the whole boundary), plane wave propagation, ellipticity, and the emergence of discontinuity surfaces. Several new and unexpected features are highlighted: (i.) Ellipticity is mainly dictated by the 'Cosserat part' of the elasticity and (ii.) its failure is shown to be related to the emergence of discontinuity surfaces; (iii.) Ellipticity and wave propagation are not interdependent conditions (so that it is possible for waves not to propagate when the material is still in the elliptic range and, in very special cases, for waves to propagate when ellipticity does not hold). The proof that loss of ellipticity induces stress channelling, folding and faulting of an elastic Cosserat continuum (and the related derivation of the infinite-body Green's function under antiplane strain conditions) is deferred to Part II of this study.

  12. Instability of large solitary water waves

    E-Print Network [OSTI]

    Zhiwu Lin

    2008-03-03

    We consider the linearized instability of 2D irrotational solitary water waves. The maxima of energy and the travel speed of solitary waves are not obtained at the highest wave, which has a 120 degree angle at the crest. Under the assumption of non-existence of secondary bifurcation which is confirmed numerically, we prove linear instability of solitary waves which are higher than the wave of maximal energy and lower than the wave of maximal travel speed. It is also shown that there exist unstable solitary waves approaching the highest wave. The unstable waves are of large amplitude and therefore this type of instability can not be captured by the approximate models derived under small amplitude assumptions. For the proof, we introduce a family of nonlocal dispersion operators to relate the linear instability problem with the elliptic nature of solitary waves. A continuity argument with a moving kernel formula is used to study these dispersion operators to yield the instability criterion.

  13. 11. Acoustic waves and shocks 11.1 Acoustic waves of low amplitude

    E-Print Network [OSTI]

    Pohl, Martin Karl Wilhelm

    11. Acoustic waves and shocks 11.1 Acoustic waves of low amplitude Let us consider an adiabatic (or velocity of sound waves is constant. Does that still hold for sound waves of finite amplitude? Equation 11. This is the result of the non-linear nature of the hydrodynamical equations. On should note that wave damping, e

  14. Gravity Wave Turbulence in Wave Tanks: Space and Time Statistics Sergei Lukaschuk,1,* Sergey Nazarenko,2

    E-Print Network [OSTI]

    Nazarenko, Sergey

    Gravity Wave Turbulence in Wave Tanks: Space and Time Statistics Sergei Lukaschuk,1,* Sergey the first simultaneous space-time measurements for gravity wave turbulence in a large laboratory flume. We found that the slopes of k and ! wave spectra depend on wave intensity. This cannot be explained by any

  15. Structure and anisotropy of the Mexico subduction zone based on Rayleigh-wave analysis and implications for the geometry of the Trans-Mexican Volcanic Belt

    E-Print Network [OSTI]

    Stubailo, I; Beghein, C; Davis, PM

    2012-01-01

    across the central Mexican volcanic belt at 100 W: Spatialcentral Trans-Mexican volcanic belt, Chem. Geol. , 244(3–4),Trans-Mexican volcanic belt: Slab detachment in a subduction

  16. Comparisons on offshore structure responses to random waves using linear and high-order wave theories 

    E-Print Network [OSTI]

    Ramos Heredia, Rafael Juda

    1995-01-01

    methodology for wave kinematics prediction. While the methods commonly used by the offshore industry are empirical and semi-empirical modifications of Linear (random) Wave Theory, the new approach (Hybrid Wave Model) satisfies the principles of hydrodynamics...

  17. Fully nonlinear wave-body interactions by a 2D potential numerical wave tank 

    E-Print Network [OSTI]

    Koo, Weoncheol

    2004-11-15

    A 2D fully nonlinear Numerical Wave Tank (NWT) is developed based on the potential theory, mixed Eulerian-Lagrangian (MEL) time marching scheme, and boundary element method (BEM). Nonlinear Wave deformation and wave forces on stationary and freely...

  18. Measurements and Linear Wave Theory Based Simulations of Vegetated Wave Hydrodynamics for Practical Applications 

    E-Print Network [OSTI]

    Anderson, Mary Elizabeth

    2011-10-21

    impeded. Sparse vegetation fields dissipated less wave energy than the intermediate density; however, the extremely dense fields dissipated very little, if any, wave energy and sometimes wave growth was observed. This is possibly due to the highest...

  19. Wave-Turbulence Interactions in a Breaking Mountain Wave Craig Epifanio and Tingting Qian

    E-Print Network [OSTI]

    #12;Dissipation of Mean Wave Energy · Mean wave energy E is just the total energy (kinetic + available · The dissipation of mean wave energy is caused by the turbulent momentum fluxes--specifically, by their tendency

  20. Energy-momentum relation for solitary waves of relativistic wave equations

    E-Print Network [OSTI]

    T. V. Dudnikova; A. I. Komech; H. Spohn

    2005-08-23

    Solitary waves of relativistic invariant nonlinear wave equation with symmetry group U(1) are considered. We prove that the energy-momentum relation for spherically symmetric solitary waves coincides with the Einstein energy-momentum relation for point particles.

  1. Experimental studies of irregular water wave component interactions with comparisons to the hybrid wave model 

    E-Print Network [OSTI]

    Longridge, Jonathon Kent

    1993-01-01

    Waves in the oceans pose challenging problems to offshore structural design because they arc irregular and can be highly nonlinear. Although these irregular waves can be viewed as the summation of many linear wave components of different...

  2. Axion decay and anisotropy of near-IR extragalactic background light

    E-Print Network [OSTI]

    Yan Gong; Asantha Cooray; Ketron Mitchell-Wynne; Xuelei Chen; Michael Zemcov; Joseph Smidt

    2015-11-05

    The extragalactic background light is expected to be comprised of the cumulative radiation from all galaxies and active galactic nuclei over the cosmic history. In addition to point sources, EBL also contains information from diffuse sources of radiation. An example is the intra-halo light, associated with diffuse stars in dark matter halos resulting from galaxy mergers and tidal interactions, identified based on measurements involving the angular power spectrum of infrared background anisotropies. The angular power spectra of the near-infrared intensities could still contain additional signals and a complete understanding of the nature of the IR background is still lacking in the literature. Here we explore the constraints that can be placed on the decay products associated with particle decays, especially candidate dark matter models involving axions that trace dark matter halos of galaxies. Axions with a mass around a few eV will decay via two photons with wavelengths in the near-IR band, and will leave a signature in the IR background intensity power spectrum. Using recent power spectra measurements from the Hubble Space Telescope (HST) and Cosmic Infrared Background Experiment (CIBER), we find that the 0.6 to 1.6 micron power spectra can be explained with an axion mass of around 4 eV and a total axion abundance as a fractional energy density Omega_a~0.05. Such an abundance is comparable to the baryon density of the Universe. The absolute EBL intensity of axion decay photons is slightly below 1 nW m^-2 sr^-1 at near-IR wavelengths, roughly a factor of 10 to 20 below the total integrated light from galaxies. The suggested axion mass and abundance are not ruled out by existing cosmological observations.

  3. The precision of slow-roll predictions for the CMBR anisotropies

    E-Print Network [OSTI]

    Jerome Martin; Dominik Schwarz

    2000-05-25

    Inflationary predictions for the anisotropy of the cosmic microwave background radiation (CMBR) are often based on the slow-roll approximation. We study the precision with which the multipole moments of the temperature two-point correlation function can be predicted by means of the slow-roll approximation. We ask whether this precision is good enough for the forthcoming high precision observations by means of the MAP and Planck satellites. The error in the multipole moments due to the slow-roll approximation is demonstrated to be bigger than the error in the power spectrum. For power-law inflation with $n_S=0.9$ the error from the leading order slow-roll approximation is $\\approx 5%$ for the amplitudes and $\\approx 20%$ for the quadrupoles. For the next-to-leading order the errors are within a few percent. The errors increase with $|n_S - 1|$. To obtain a precision of 1% it is necessary, but in general not sufficient, to use the next-to-leading order. In the case of power-law inflation this precision is obtained for the spectral indices if $|n_S - 1| < 0.02$ and for the quadrupoles if $|n_S - 1| < 0.15$ only. The errors in the higher multipoles are even larger than those for the quadrupole, e.g. $\\approx 15%$ for l=100, with $n_S = 0.9$ at the next-to-leading order. We find that the accuracy of the slow-roll approximation may be improved by shifting the pivot scale of the primordial spectrum (the scale at which the slow-roll parameters are fixed) into the regime of acoustic oscillations. Nevertheless, the slow-roll approximation cannot be improved beyond the next-to-leading order in the slow-roll parameters.

  4. Effects of ion abundances on electromagnetic ion cyclotron wave growth rate in the vicinity of the plasmapause

    SciTech Connect (OSTI)

    Henning, F. D. Mace, R. L.

    2014-04-15

    Electromagnetic ion cyclotron (EMIC) waves in multi-ion species plasmas propagate in branches. Except for the branch corresponding to the heaviest ion species, which has only a resonance at its gyrofrequency, these branches are bounded below by a cutoff frequency and above by a resonant gyrofrequency. The condition for wave growth is determined by the thermal anisotropies of each ion species, j, which sets an upper bound, ?{sub j}{sup ?}, on the wave frequency below which that ion species contributes positively to the growth rate. It follows that the relative positions of the cutoffs and the critical frequencies ?{sub j}{sup ?} play a crucial role in determining whether a particular wave branch will be unstable. The effect of the magnetospheric ion abundances on the growth rate of each branch of the EMIC instability in a model where all the ion species have kappa velocity distributions is investigated by appealing to the above ideas. Using the variation of the cutoff frequencies predicted by cold plasma theory as a guide, optimal ion abundances that maximise the EMIC instability growth rate are sought. When the ring current is comprised predominantly of H{sup +} ions, all branches of the EMIC wave are destabilised, with the proton branch having the maximum growth rate. When the O{sup +} ion abundance in the ring current is increased, a decrease in the growth rate of the proton branch and cyclotron damping of the helium branch are observed. The oxygen branch, on the other hand, experiences an increase in the maximum growth rate with an increase in the O{sup +} ion abundance. When the ring current is comprised predominantly of He{sup +} ions, only the helium and oxygen branches of the EMIC wave are destabilised, with the helium branch having the maximum growth rate.

  5. Surface wave chemical detector using optical radiation

    DOE Patents [OSTI]

    Thundat, Thomas G.; Warmack, Robert J.

    2007-07-17

    A surface wave chemical detector comprising at least one surface wave substrate, each of said substrates having a surface wave and at least one measurable surface wave parameter; means for exposing said surface wave substrate to an unknown sample of at least one chemical to be analyzed, said substrate adsorbing said at least one chemical to be sensed if present in said sample; a source of radiation for radiating said surface wave substrate with different wavelengths of said radiation, said surface wave parameter being changed by said adsorbing; and means for recording signals representative of said surface wave parameter of each of said surface wave substrates responsive to said radiation of said different wavelengths, measurable changes of said parameter due to adsorbing said chemical defining a unique signature of a detected chemical.

  6. Global coherence of dust density waves

    SciTech Connect (OSTI)

    Killer, Carsten; Melzer, André

    2014-06-15

    The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

  7. Two-wave interaction in ideal magnetohydrodynamics

    E-Print Network [OSTI]

    T. V. Zaqarashvili; B. Roberts

    2006-02-24

    The weakly nonlinear interaction of sound and linearly polarised Alfv{\\'e}n waves propagating in the same direction along an applied magnetic field is studied. It is found that a sound wave is coupled to the Alfv{\\'e}n wave with double period and wavelength when the sound and Alfv{\\'e}n speeds are equal. The Alfv{\\'e}n wave drives the sound wave through the ponderomotive force, while the sound wave returns energy back to the Alfv{\\'e}n wave through the parametric (swing) influence. As a result, the two waves alternately exchange their energy during propagation. The process of energy exchange is faster for waves with stronger amplitudes. The phenomenon can be of importance in astrophysical plasmas, including the solar atmosphere and solar wind.

  8. B8 Page 1 B8. Using CMS-Wave

    E-Print Network [OSTI]

    US Army Corps of Engineers

    B8 ­ Page 1 B8. Using CMS-Wave The most recent CMS-Wave code developed is Version 3.2. Several new capabilities and advanced features in this version include: · Full-plane wind-generation of waves · Automatic wave run-up calculation · Infra-gravity wave calculation · Nonlinear wave-wave interaction · Muddy

  9. Wave propagation in complex coordinates

    E-Print Network [OSTI]

    Horsley, S A R; Philbin, T G

    2015-01-01

    We investigate the analytic continuation of wave equations into the complex position plane. For the particular case of electromagnetic waves we provide a physical meaning for such an analytic continuation in terms of a family of closely related inhomogeneous media. For bounded permittivity profiles we find the phenomenon of reflection can be related to branch cuts in the wave that originate from poles of the permittivity at complex positions. Demanding that these branch cuts disappear, we derive a large family of inhomogeneous media that are reflectionless for a single angle of incidence. Extending this property to all angles of incidence leads us to a generalized form of the Poschl Teller potentials. We conclude by analyzing our findings within the phase integral (WKB) method.

  10. Wave-Climate Risk Analysis: Predicting the Size, Frequency and Duration of Large Wave Events

    E-Print Network [OSTI]

    Sobey, Rodney

    2002-01-01

    2001, “Wave Climate Risk Analysis. ” Winslow, Kyle, Ph.D. in2.28.2001 Wave-Climate Risk Analysis: Predicting the Size,

  11. Standing waves for a two-way model system for water waves

    E-Print Network [OSTI]

    2004-10-18

    Sep 12, 2004 ... that, contrary to the classical standing gravity wave problem on a fluid .... The standing waves we are looking for are solutions (?, u) doubly ...

  12. Nonlocal theory of electromagnetic wave decay into two electromagnetic waves in a rippled density plasma channel

    SciTech Connect (OSTI)

    Sati, Priti; Tripathi, V. K.

    2012-12-15

    Parametric decay of a large amplitude electromagnetic wave into two electromagnetic modes in a rippled density plasma channel is investigated. The channel is taken to possess step density profile besides a density ripple of axial wave vector. The density ripple accounts for the momentum mismatch between the interacting waves and facilitates nonlinear coupling. For a given pump wave frequency, the requisite ripple wave number varies only a little w.r.t. the frequency of the low frequency decay wave. The radial localization of electromagnetic wave reduces the growth rate of the parametric instability. The growth rate decreases with the frequency of low frequency electromagnetic wave.

  13. Wave propagation in anisotropic viscoelasticity

    E-Print Network [OSTI]

    Andrzej Hanyga

    2015-07-01

    We extend the theory of complete Bernstein functions to matrix-valued functions and apply it to analyze Green's function of an anisotropic multi-dimension\\-al linear viscoelastic problem. Green's function is given by the superposition of plane waves. Each plane wave is expressed in terms of matrix-valued attenuation and dispersion functions given in terms of a matrix-valued positive semi-definite Radon measure. More explicit formulae are obtained for 3D isotropic viscoelastic Green's functions. As an example of an anisotropic medium the transversely isotropic medium with a constant symmetry axis is considered.

  14. Laser-ultrasound spectroscopy apparatus and method with detection of shear resonances for measuring anisotropy, thickness, and other properties

    DOE Patents [OSTI]

    Levesque, Daniel (Terrebonne, CA); Moreau, Andre (St-Bruno-de-Montarville, CA); Dubois, Marc (Montreal, CA); Monchalin, Jean-Pierre (Montreal, CA); Bussiere, Jean (St-Bruno, CA); Lord, Martin (Beloeil, CA); Padioleau, Christian (Montreal, CA)

    2000-01-01

    Apparatus and method for detecting shear resonances includes structure and steps for applying a radiation pulse from a pulsed source of radiation to an object to generate elastic waves therein, optically detecting the elastic waves generated in the object, and analyzing the elastic waves optically detected in the object. These shear resonances, alone or in combination with other information, may be used in the present invention to improve thickness measurement accuracy and to determine geometrical, microstructural, and physical properties of the object. At least one shear resonance in the object is detected with the elastic waves optically detected in the object. Preferably, laser-ultrasound spectroscopy is utilized to detect the shear resonances.

  15. Experimental Investigation of Mass Sensing With Surface Acoustic Wave Devices

    E-Print Network [OSTI]

    MacDonald, Frank Dickinson

    2010-01-01

    Colin, “1927- Surface acoustic wave devices for mobile andColin, “1927- Surface acoustic wave devices and their signalhorizontal surface acoustic waves (SH-SAW) sensor. Figure 9.

  16. Sandia Energy - WEC-Sim (Wave Energy Converter SIMulator)

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

    WEC-Sim (Wave Energy Converter SIMulator) Home Stationary Power Energy Conversion Efficiency Water Power WEC-Sim (Wave Energy Converter SIMulator) WEC-Sim (Wave Energy Converter...

  17. Spatial and temporal modulation of internal waves and thermohaline structure

    E-Print Network [OSTI]

    Cole, Sylvia T.

    2010-01-01

    of outward internal wave energy and dissipation was 17 GW.between internal wave energy density, energy flux, andstructure of internal wave energy density, energy flux, and

  18. Langmuir Waves and Electron Acceleration at Heliospheric Shocks

    E-Print Network [OSTI]

    Pulupa, Marc Peter

    2010-01-01

    observations. . . . . . . . . .Radio wave, magnetic field,Acceleration, Plasma Waves, and Radio Emission 3.1 RadioProfessor Stuart Bale, Chair Radio waves at the local plasma

  19. Experimental study of internal wave generation by convection in water

    E-Print Network [OSTI]

    2015-01-01

    study of internal wave generation by convection in waterstudies of internal wave generation by convective turbulenceintermittent generation of internal waves. We also computed

  20. A Novel Overtopping Wave Energy Device Concept Applied to California

    E-Print Network [OSTI]

    Imamura, John

    2009-01-01

    for overtopping wave energy devices are limited in theirhigh power output wave energy devices may be possible.design and modeling of wave energy devices. Nat- urally this

  1. Stress Wave Source Characterization: Impact, Fracture, and Sliding Friction

    E-Print Network [OSTI]

    McLaskey, Gregory Christofer

    2011-01-01

    717-725. Graff, K. (1975). Wave Motion in Elastic Solids (and deterioration on stress wave velocities in concrete,Greenspan, M. (1981) Surface-wave displacement: absolute

  2. Identifying two steps in the internal wave energy cascade

    E-Print Network [OSTI]

    Sun, Oliver Ming-Teh

    2010-01-01

    1.1.1 The internal wave energy cascade . . . . . . .? ? , which contain only wave energy trav- eling upward anddistinction is made between wave energy propagating upward

  3. Long wave expansions for water waves over random topography

    E-Print Network [OSTI]

    Anne de Bouard; Walter Craig; Oliver Díaz-Espinosa; Philippe Guyenne; Catherine Sulem

    2007-10-01

    In this paper, we study the motion of the free surface of a body of fluid over a variable bottom, in a long wave asymptotic regime. We assume that the bottom of the fluid region can be described by a stationary random process $\\beta(x, \\omega)$ whose variations take place on short length scales and which are decorrelated on the length scale of the long waves. This is a question of homogenization theory in the scaling regime for the Boussinesq and KdV equations. The analysis is performed from the point of view of perturbation theory for Hamiltonian PDEs with a small parameter, in the context of which we perform a careful analysis of the distributional convergence of stationary mixing random processes. We show in particular that the problem does not fully homogenize, and that the random effects are as important as dispersive and nonlinear phenomena in the scaling regime that is studied. Our principal result is the derivation of effective equations for surface water waves in the long wave small amplitude regime, and a consistency analysis of these equations, which are not necessarily Hamiltonian PDEs. In this analysis we compute the effects of random modulation of solutions, and give an explicit expression for the scattered component of the solution due to waves interacting with the random bottom. We show that the resulting influence of the random topography is expressed in terms of a canonical process, which is equivalent to a white noise through Donsker's invariance principle, with one free parameter being the variance of the random process $\\beta$. This work is a reappraisal of the paper by Rosales & Papanicolaou \\cite{RP83} and its extension to general stationary mixing processes.

  4. Wave VelocityWave Velocity Diff t f ti l l itDifferent from particle velocity

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    Wave VelocityWave Velocity v=/T =f Diff t f ti l l itDifferent from particle velocity Depends on the medium in which the wave travelsDepends on the medium in which the wave travels stringaonvelocity F v of Waves11-8. Types of Waves Transverse wave Longitudinal wave Liu UCD Phy1B 2014 37 #12;Sound Wave

  5. Dynamic response of phenolic resin and its carbon-nanotube composites to shock wave loading

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

    Arman, B.; An, Q.; Luo, S. N.; Desai, T. G.; Tonks, D. L.; C?ag??n, T.; Goddard, III, W. A.

    2011-01-04

    We investigate with nonreactive molecular dynamics simulations the dynamic response of phenolic resin and its carbon-nanotube (CNT) composites to shock wave compression. For phenolic resin, our simulations yield shock states in agreement with experiments on similar polymers except the “phase change” observed in experiments, indicating that such phase change is chemical in nature. The elastic–plastic transition is characterized by shear stress relaxation and atomic-level slip, and phenolic resin shows strong strain hardening. Shock loading of the CNT-resin composites is applied parallel or perpendicular to the CNT axis, and the composites demonstrate anisotropy in wave propagation, yield and CNT deformation. Themore »CNTs induce stress concentrations in the composites and may increase the yield strength. Our simulations indicate that the bulk shock response of the composites depends on the volume fraction, length ratio, impact cross-section, and geometry of the CNT components; the short CNTs in current simulations have insignificant effect on the bulk response of resin polymer.« less

  6. Probing Spin-Relaxation Anisotropy in 1D InSb Wires by Weak Anti-Localization

    SciTech Connect (OSTI)

    Jayathilaka, P. A. R. D.; Cairns, S.; Keay, J.; Murphy, S. Q.; Gaspe, C. K.; Mishima, T. D.; Santos, M. B. [Homer L. Dodge Department of Physics and Astronomy, Center for Semiconductor Physics in Nanostructures (C-SPIN), University of Oklahoma, Norman, OK (United States)

    2011-12-26

    Arrays of quasi-one-dimensional wires were fabricated in symmetrically doped AlInSb/InSb heterostructures to investigate the dimensional suppression of electron spin relaxation. Using weak localization analysis, it was discovered that the spin relaxation length in 300nm wide wires was enhanced by 40% relative to the two-dimensional value. Moreover, wires aligned along the <100> direction showed spin relaxation lengths {approx}30% longer than for wires aligned along <110>. This anisotropy is consistent with the additional influence of the cubic Dresselhaus interaction along the <110> direction which is predicted to be unaffected by dimensional confinement.

  7. Dielectron Azimuthal Anisotropy at mid-rapidity in Au+Au collisions at root s=200GeV

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

    Adamczyk, L. [AGH University of Science and Technology, Cracow (Poland); STAR Collaboration

    2014-12-01

    We report on the first measurement of the azimuthal anisotropy (v?) of dielectrons (e?e? pairs) at mid-rapidity from ?(sNN)=200 GeV Au + Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Meeee<2.9GeV/c², the measured dielectron v? is consistent, within experimental uncertainties, with that from the cc¯ contributions.

  8. Dielectron Azimuthal Anisotropy at mid-rapidity in Au+Au collisions at root s=200GeV

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

    Adamczyk, L.

    2014-12-11

    We report on the first measurement of the azimuthal anisotropy (v?) of dielectrons (e?e? pairs) at mid-rapidity from ?(sNN)=200 GeV Au + Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Meeee<2.9GeV/c², the measured dielectron v? is consistent, within experimental uncertainties, with that from the cc¯ contributions.

  9. Multicomponent seismic data, combining P-wave and converted P-to-SV wave (C-wave) wavefields, provide inde-

    E-Print Network [OSTI]

    Texas at Austin, University of

    Multicomponent seismic data, combining P-wave and converted P-to-SV wave (C-wave) wavefields (fast and slow) with differing polarization. The 4C, 3D ocean-bottom cable (OBC) multicomponent seismic objectives were to evaluate seismic attributes, such as VP/VS velocity ratios and Poisson's ratio derived

  10. Introduction Modeling of large ocean waves Propagation speed Coherent wavetrains Near-shore wave dynamics Conclusions Tsunamis and ocean waves

    E-Print Network [OSTI]

    Craig, Walter

    dynamics Conclusions Tsunamis and ocean waves Walter Craig Department of Mathematics & Statistics AAAS Annual Meeting St. Louis Missouri February 19, 2006 Walter Craig McMaster University Tsunamis and ocean-shore wave dynamics Conclusions Introduction Tsunami waves are generated relatively often, from various

  11. Wave functions of linear systems

    E-Print Network [OSTI]

    Tomasz Sowinski

    2007-06-05

    Complete analysis of quantum wave functions of linear systems in an arbitrary number of dimensions is given. It is shown how one can construct a complete set of stationary quantum states of an arbitrary linear system from purely classical arguments. This construction is possible because for linear systems classical dynamics carries the whole information about quantum dynamics.

  12. Variational Principles for Water Waves

    E-Print Network [OSTI]

    Boris Kolev; David H. Sattinger

    2007-12-01

    We describe the Hamiltonian structures, including the Poisson brackets and Hamiltonians, for free boundary problems for incompressible fluid flows with vorticity. The Hamiltonian structure is used to obtain variational principles for stationary gravity waves both for irrotational flows as well as flows with vorticity.

  13. EVOLUTION OF L HYBRID WAVES

    E-Print Network [OSTI]

    Karney, Charles

    . INTRODUCTIO In typical lower hybrid heating schemes, lower hybrid waves are launched at the wall sf tokamak. In this paper we study the C numerically, and determine the consequences of our results for lower hybrid heating hybrid heating of a tokamak. 11. THE CMKDV EQUAT The two-dimensional steady-state propagation of a single

  14. WAVE-ENERGY DENSITY AND WAVE-MOMENTUM DENSITY OF EACH SPECIES OF A COLLISION-LESS PLASMA

    E-Print Network [OSTI]

    Cary, John R.

    2012-01-01

    case, the electrons have negative wave energy for 2w ne w wave energy for 2w .w > 0 nl Hence, unstable waves with negative phase velocity,

  15. CX-009134: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Wave Energy Technology- New Zealand Multi-Mode Wave Energy Converter Advancement Project CX(s) Applied: A9, B3.6 Date: 08/20/2012 Location(s): Oregon Offices(s): Golden Field Office

  16. CX-010213: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Wave Energy Technology- New Zealand Multi-Mode Wave Energy Converter Advancement Project CX(s) Applied: A9 Date: 01/08/2013 Location(s): Hawaii, Oregon Offices(s): Golden Field Office

  17. Analysis of optimum Lamb wave tuning

    E-Print Network [OSTI]

    Shi, Yijun, 1970-

    2002-01-01

    Guided waves are of enormous interest in the nondestructive evaluation of thin-walled structures and layered media. Due to their dispersive and multi-modal nature, it is desirable to tune the waves by discriminating one ...

  18. Wind effects on shoaling wave shape

    E-Print Network [OSTI]

    Feddersen, F; Veron, F

    2005-01-01

    breaking in the presence of wind drift and swell. J. Fluidlin, 1995: Asymmetry of wind waves studied in a laboratorycoupling between swell and wind-waves. J. Phys. Oceanogr. ,

  19. Turbulent round jet under gravity waves 

    E-Print Network [OSTI]

    Ryu, Yong Uk

    2002-01-01

    The behavior of a neutrally buoyant horizontal turbulent round jet under a wavy environment was investigated. Progressive waves with different wave amplitudes in an intermediate water depth were used. The Particle Image Velocimetry (PIV) technique...

  20. Generation of sand bars under surface waves

    E-Print Network [OSTI]

    Hancock, Matthew James, 1975-

    2005-01-01

    (cont.) Experiments were performed in a large wave flume to validate the theory and to study additional aspects of sand bar evolution. The wave envelope and bar profile were recorded for low and high beach reflection, ...

  1. Fracture compliance estimation using borehole tube waves

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    We tested two models, one for tube-wave generation and the other for tube-wave attenuation at a fracture intersecting a borehole that can be used to estimate fracture compliance, fracture aperture, and lateral extent. In ...

  2. Gravitational waves from merging compact binaries

    E-Print Network [OSTI]

    Hughes, Scott A.

    Largely motivated by the development of highly sensitive gravitational-wave detectors, our understanding of merging compact binaries and the gravitational waves they generate has improved dramatically in recent years. ...

  3. Wave Mechanics and General Relativity: A Rapprochement

    E-Print Network [OSTI]

    Paul S. Wesson

    2006-01-16

    Using exact solutions, we show that it is in principle possible to regard waves and particles as representations of the same underlying geometry, thereby resolving the problem of wave-particle duality.

  4. On quantization of nondispersive wave packets

    SciTech Connect (OSTI)

    Altaisky, M. V.

    2013-10-15

    Nondispersive wave packets are widely used in optics and acoustics. We found it interesting that such packets could be also a subject of quantum field theory. Canonical commutation relations for the nondispersive wave packets are constructed.

  5. Wave radiation in simple geophysical models 

    E-Print Network [OSTI]

    Murray, Stuart William

    2013-07-01

    Wave radiation is an important process in many geophysical flows. In particular, it is by wave radiation that flows may adjust to a state for which the dynamics is slow. Such a state is described as “balanced”, meaning ...

  6. Oblique reflections of internal gravity wave beams

    E-Print Network [OSTI]

    Karimi, Hussain H. (Hussain Habibullah)

    2012-01-01

    We study nonlinear effects in reflections of internal gravity wave beams in a continuously stratified liquid which are incident upon a uniform slope at an oblique angle. Wave motion in a stratified fluid medium is unique ...

  7. Carbon nanotube-guided thermopower waves

    E-Print Network [OSTI]

    Choi, Wonjoon

    Thermopower waves are a new concept for the direct conversion of chemical to electrical energy. A nanowire with large axial thermal diffusivity can accelerate a self-propagating reaction wave using a fuel coated along its ...

  8. Arnold Schwarzenegger DEVELOPING WAVE ENERGY IN

    E-Print Network [OSTI]

    Arnold Schwarzenegger Governor DEVELOPING WAVE ENERGY IN COASTAL CALIFORNIA: POTENTIAL SOCIO. Developing Wave Energy In Coastal California: Potential Socio-Economic And Environmental Effects. California-ECONOMIC AND ENVIRONMENTAL EFFECTS Prepared For: California Energy Commission Public Interest Energy Research Program

  9. Electromagnetic wave scattering by Schwarzschild black holes

    E-Print Network [OSTI]

    Luís C. B. Crispino; Sam R. Dolan; Ednilton S. Oliveira

    2009-05-20

    We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

  10. An electromagnetic analog of gravitational wave memory

    E-Print Network [OSTI]

    Lydia Bieri; David Garfinkle

    2013-09-10

    We present an electromagnetic analog of gravitational wave memory. That is, we consider what change has occurred to a detector of electromagnetic radiation after the wave has passed. Rather than a distortion in the detector, as occurs in the gravitational wave case, we find a residual velocity (a "kick") to the charges in the detector. In analogy with the two types of gravitational wave memory ("ordinary" and "nonlinear") we find two types of electromagnetic kick.

  11. Gravitational wave in Lorentz violating gravity

    E-Print Network [OSTI]

    Xin Li; Zhe Chang

    2012-04-01

    By making use of the weak gravitational field approximation, we obtain a linearized solution of the gravitational vacuum field equation in an anisotropic spacetime. The plane-wave solution and dispersion relation of gravitational wave is presented explicitly. There is possibility that the speed of gravitational wave is larger than the speed of light and the casuality still holds. We show that the energy-momentum of gravitational wave in the ansiotropic spacetime is still well defined and conserved.

  12. Wave-driven Countercurrent Plasma Centrifuge

    SciTech Connect (OSTI)

    A.J. Fetterman and N.J. Fisch

    2009-03-20

    A method for driving rotation and a countercurrent flow in a fully ionized plasma centrifuge is described. The rotation is produced by radiofrequency waves near the cyclotron resonance. The wave energy is transferred into potential energy in a manner similar to the ? channeling effect. The countercurrent flow may also be driven by radiofrequency waves. By driving both the rotation and the flow pattern using waves instead of electrodes, physical and engineering issues may be avoided.

  13. Secondary dust density waves excited by nonlinear dust acoustic waves J. R. Heinrich,1,a)

    E-Print Network [OSTI]

    Merlino, Robert L.

    Secondary dust density waves excited by nonlinear dust acoustic waves J. R. Heinrich,1,a) S.-H. Kim amplitude ðnd=nd0 > 2Þ dust acoustic waves (DAW) that were spontaneously excited in a dc glow discharge dusty plasma in the moderately coupled, C $ 1; state. The high amplitude dust acoustic waves produced

  14. Observations of dust acoustic waves driven at high frequencies: Finite dust temperature effects and wave interference

    E-Print Network [OSTI]

    Merlino, Robert L.

    Observations of dust acoustic waves driven at high frequencies: Finite dust temperature effects An experiment has been performed to study the behavior of dust acoustic waves driven at high frequencies f 100 are observed--interference effects between naturally excited dust acoustic waves and driven dust acoustic waves

  15. One-way wave-equation migration of compressional and converted waves in a VTI medium

    E-Print Network [OSTI]

    Ursin, Bjørn

    One-way wave-equation migration of compressional and converted waves in a VTI medium Ørjan Pedersen- sure and shear-wave reflections, one can increase the amount of information obtained about the subsur- face than by recording pressure waves alone. Geo- logic structures which are not visible by using con

  16. 2013 MLML Wave Award Deadline: February 8, 2013 The 2013 MLML Wave Award

    E-Print Network [OSTI]

    McPhee-Shaw, Erika

    2013 MLML Wave Award Deadline: February 8, 2013 The 2013 MLML Wave Award Sponsored by the MLML Associated Student Body Application Deadline: Friday, February 8, 2013 The Friends of MLML is pleased to announce the 2013 MLML Wave Award. The 2013 MLML Wave Award is sponsored

  17. Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves

    E-Print Network [OSTI]

    Klein, Spencer

    2010-01-01

    waves generated by the thermoacoustic mechanism, little workproduction by the thermoacoustic mechanism is suppressed,

  18. The Effects of Wave Energy Converters on a Monochromatic Wave Climate

    E-Print Network [OSTI]

    Fox-Kemper, Baylor

    in wave energy converters as a possible means of providing renewable energy, the effects of a wave energy The interest in renewable energies is currently increasing due to the reported rise in global temperature and mean wave period of wave energy fields. There is tremendous energy potential in the ocean. Solar energy

  19. Beauty waves: an artistic representation of ocean waves using Bezier curves 

    E-Print Network [OSTI]

    Faulkner, Jay Allen

    2007-04-25

    In this thesis, we present a method for computing an artistic representation of ocean waves using Bezier curves. Wave forms are loosely based on procedural wave models and are designed to emulate those found in both art and nature. The wave forms...

  20. CHARACTERIZING DANGEROUS WAVES FOR OCEAN WAVE ENERGY CONVERTER SURVIVABILITY Justin Hovland

    E-Print Network [OSTI]

    Haller, Merrick

    gradient technologies. This paper is focused on Ocean Wave Energy Converters (OWECs) and the needCHARACTERIZING DANGEROUS WAVES FOR OCEAN WAVE ENERGY CONVERTER SURVIVABILITY Justin Hovland ABSTRACT Ocean Wave Energy Converters (OWECs) operating on the water surface are subject to storms

  1. Wave Front Interaction Model of Stabilized Propagating Wave Segments Vladimir S. Zykov1

    E-Print Network [OSTI]

    Showalter, Kenneth

    Wave Front Interaction Model of Stabilized Propagating Wave Segments Vladimir S. Zykov1 and Kenneth; published 14 February 2005) A wave front interaction model is developed to describe the relationship between excitability and the size and shape of stabilized wave segments in a broad class of weakly excitable media

  2. Full-wave Electromagnetic Field Simulations of Lower Hybrid Waves in Tokamaks

    E-Print Network [OSTI]

    Wright, John C.

    Full-wave Electromagnetic Field Simulations of Lower Hybrid Waves in Tokamaks J. C. Wright , P. T, VA, USA Abstract. The most common method for treating wave propagation in tokamaks in the lower of 2D and 3D plasma inhomogeneity effects on wave propagation, the approach neglects important effects

  3. Title of Document: STUDIES OF HIGH FREQUENCY WAVE EXCITATION IN FAST AND SLOW WAVE

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of Document: STUDIES OF HIGH FREQUENCY WAVE EXCITATION IN FAST AND SLOW WAVE VACUUM of Electrical and Computer Engineering and Department of Physics THz and millimeter-wave length radiation are considered: the reduction in bunching efficiency in orotrons (a slow wave device), and the excitation

  4. WAVE HEIGHTS IN A 4D OCEAN WAVE FIELD Paul C. Liu

    E-Print Network [OSTI]

    WAVE HEIGHTS IN A 4D OCEAN WAVE FIELD Paul C. Liu NOAA Great Lakes Environmental Research a preliminary examination and analysis of a small suite of 4-D wave data to explore what new insight century. We feel it is timely to encourage further 4-D ocean wave measurement and thereby facilitate fresh

  5. Investigating wave data from the FAST satellite by reconstructing the wave distribution function

    E-Print Network [OSTI]

    California at Berkeley, University of

    Investigating wave data from the FAST satellite by reconstructing the wave distribution function G September 2001; published 15 August 2002. [1] We study wave measurements made by the FAST satellite at 4100-km altitude in the auroral region. Three electric and three magnetic wave field components

  6. Wave Turbulence in Superfluid 4 Energy Cascades, Rogue Waves & Kinetic Phenomena

    E-Print Network [OSTI]

    Fominov, Yakov

    Outline Wave Turbulence in Superfluid 4 He: Energy Cascades, Rogue Waves & Kinetic Phenomena Conference, Chernogolovka, 3 August 2009 McClintock Efimov Ganshin Kolmakov Mezhov-Deglin Wave Turbulence in Superfluid 4 He #12;Outline Outline 1 Introduction Motivation 2 Modelling wave turbulence Need for models

  7. SOLITARY WAVE INTERACTION IN A COMPACT EQUATION FOR DEEP-WATER GRAVITY WAVES

    E-Print Network [OSTI]

    Boyer, Edmond

    SOLITARY WAVE INTERACTION IN A COMPACT EQUATION FOR DEEP-WATER GRAVITY WAVES FRANCESCO FEDELE of the Zakharov equation for unidirectional deep-water waves recently derived by Dyachenko & Zakharov [7-conserving quantities. Key words and phrases. water waves; deep water approximation; Hamiltonian structure; travelling

  8. Ronald Edward Kumon NONLINEAR SURFACE ACOUSTIC WAVES

    E-Print Network [OSTI]

    Copyright by Ronald Edward Kumon 1999 #12;NONLINEAR SURFACE ACOUSTIC WAVES IN CUBIC CRYSTALS THE UNIVERSITY OF TEXAS AT AUSTIN December 1999 #12;NONLINEAR SURFACE ACOUSTIC WAVES IN CUBIC CRYSTALS Approved Zabolotskaya for teaching me the intricacies of nonlinear surface acoustic waves and for their continuing

  9. Wave Packets and Turbulent Peter Jordan1

    E-Print Network [OSTI]

    Dabiri, John O.

    Wave Packets and Turbulent Jet Noise Peter Jordan1 and Tim Colonius2 1 D´epartement Fluides-control efforts is incomplete. Wave packets are intermittent, advecting disturbances that are correlated over review evidence of the existence, energetics, dynamics, and acous- tic efficiency of wave packets. We

  10. Wave guides: vacuum w/ tube of conductor

    E-Print Network [OSTI]

    Hart, Gus

    Wave guides: vacuum w/ tube of conductor boundary conditions for conductor Properties: non-transverse waves except TEM mode in coaxial cable speed normal modes (from Liouville problem) TE or TM TEM for coaxial cable cuto frequency otherwise evanescent waves separation into and components with 1 #12;B

  11. WAVE GENERATIONS FROM CONFINED EXPLOSIONS IN ROCKS

    E-Print Network [OSTI]

    Stewart, Sarah T.

    WAVE GENERATIONS FROM CONFINED EXPLOSIONS IN ROCKS C. L. Liu and Thomas J. Ahrens Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125 In order to record P- and S-waves on the interactions between incident P- and SV-waves and free-surfaces of rocks. The relations between particle

  12. CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES

    E-Print Network [OSTI]

    Karney, Charles

    -state tokamak reactors are considered. 1. INTRODUCTION The generation of electric currents in a plasma by means and, accordingly, no slow-wave structure is necessary. Moreover, the utilization of the high of the wave into the tokamak and reasonably estimates the speed of the electrons that absorb the wave

  13. Spherical fields as nonparaxial accelerating waves

    E-Print Network [OSTI]

    Miguel A. Alonso; Miguel A. Bandres

    2012-11-07

    We introduce nonparaxial spatially accelerating waves whose two-dimensional transverse profiles propagate along semicircular trajectories while approximately preserving their shape. We derive these waves by considering imaginary displacements on spherical fields, leading to simple closed-form expressions. The structure of these waves also allows the closed-form description of pulses.

  14. NONLINEAR EFFECTS IN WAVE SCATTERING AND GENERATION

    E-Print Network [OSTI]

    NONLINEAR EFFECTS IN WAVE SCATTERING AND GENERATION Flow Interaction with Topography Roger Grimshaw for waves to be generated upstream and/or downstream. In many cases when the topographic feature has a small, the initial condition for the fKdV equation is u(x 0) = 0 so that the waves are generated directly by the ow

  15. METACHRONAL WAVE GAIT GENERATION FOR HEXAPOD ROBOTS

    E-Print Network [OSTI]

    Parker, Gary B.

    METACHRONAL WAVE GAIT GENERATION FOR HEXAPOD ROBOTS GARY B. PARKER and JONATHAN W. MILLS Department@cs.indiana.edu ABSTRACT The metachronal wave is a gait used by most terrestrial arthropods. Each leg only lifts when the leg behind it is on the ground in position to support the animal's weight. The wave starts from

  16. Wave Evolution On the Evolution of Curvelets

    E-Print Network [OSTI]

    Smith, Hart F.

    Curvelets Wave Evolution On the Evolution of Curvelets by the Wave Equation Hart F. Smith Department of Mathematics University of Washington, Seattle 1st PRIMA Congress Hart F. Smith On the Evolution(x) = c (x) c = f(x) (x) dx Hart F. Smith On the Evolution of Curvelets by the Wave Equation #12;Curvelets

  17. Wave Energy Development Roadmap: Design to Commercialization

    E-Print Network [OSTI]

    Siefert, Chris

    the pathway from initial design to commercialization for Wave Energy Converter (WEC) technologies. Commercialization of a wave energy technology is embodied in the deployment of an array of WEC's, a WEC Farm. Index Terms--Wave Energy, Roadmap, Technology Readiness Levels. Numerical Modeling, Experimentation I

  18. Multi-reflective acoustic wave device

    DOE Patents [OSTI]

    Andle, Jeffrey C.

    2006-02-21

    An acoustic wave device, which utilizes multiple localized reflections of acoustic wave for achieving an infinite impulse response while maintaining high tolerance for dampening effects, is disclosed. The device utilized a plurality of electromechanically significant electrodes disposed on most of the active surface. A plurality of sensors utilizing the disclosed acoustic wave mode device are also described.

  19. WAVE-DRIVEN SURFACE FROM HF RADAR

    E-Print Network [OSTI]

    Miami, University of

    FEATURE INTERNAL CURRENTS WAVE-DRIVEN SURFACE FROM HF RADAR By Lynn K. Shay Observations from recent experiments · . . have revealed internal wave signatures. SURFACE CURRENTobservations from high oscillations are within the inter- nal wave continuum from the buoyancy to the in- ertial frequencies

  20. Wave Motion Unit code: MATH35012

    E-Print Network [OSTI]

    Sidorov, Nikita

    MATH35012 Wave Motion Unit code: MATH35012 Credit Rating: 10 Unit level: Level 3 Teaching period This course unit aims to elucidate some of the physical properties of important types of wave motion and their mathematical descriptions. Overview Wave motion occurs in the oceans, atmosphere and in the earth. Problems